Title of Invention

CONTROL METHOD FOR ELECTROMAGNETIC FULE PUMP

Abstract

THE PROBLEM TO BE SOLVED: To control the starting operation of a fuel pump 26 using either of the first operation mode and second operation mode by providing a control means 55 with the first operation mode to be set when the battery voltage VB possible to operate a starter motor 33 is detected and second operation mode different from the first operation mode and to be set, when the battery voltage VB is incapable of operation for the starter motor 33 is detected. SOLUTION: start time control for an electromagnetic fuel pump can be performed with an appropriate control content different between a case of starting an engine with a kick starting device and a case of starting a engine by a starter motor standing device. For example, engine starting ability by the kick starting device when the fuel is inside the carburetor is consumed can be improved, and the power to be supplied to the fuel pump can be restricted, when starting the engine by the starter motor starting device.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] PROVISIONAL/COMPLETE SPECIFICATION [See Section 10] "CONTROL METHOD FOR ELECTROMAGNETIC FUEL PUMP" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan The following specification particularly describes the nature of the invention and the manner in which it is to be performed :- [DETAILED DESSCRIPTION OF THE INVENTION] [0001] [Technical Field to which the Invention Pertains] This invention relates to a control method for an electromagnetic fuel pump upon starting of an engine suitable for starting of the engine by a starter motor and starting of the engine by a kick pedal, and a control method for an engine provided with an electromagnetic fuel pump sui table when the electromagnetic fuel pump fails. [0002] [Prior Art] As a control method for a fuel pump upon starting of an engine of a motorcycle, a method disclosed, for example, in Japanese Utility Model Laid-open No, Sho 6 3-188867 "Fuel Pump for Motorcycle" is known. [0003] FIG. 1 of the official gazette mentioned above shows a motorcycle wherein an electromagnetic fuel pump 6 is provided for an engine 1 and the engine I is rotated by a kicking operation by a kick pedal to generate an ignition pulse signal by means of a CDI unit 11 to feed the electromagnetic fuel pump 6 for a time after the kicking operation is detected until a fixed time elapses after the rotation of the engine 1 stops. 2- [0004] [Problems to Be Solved by the Invention] For example, if the battery of the motorcycle is consumed and starting by means of a starter motor starting apparatus is disabled, then the engine 1 is started by means of the kick pedal of a kick starting apparatus. However, particularly when no fuel is present in a carburetor 9, since, upon starting by means of the kick pedal, the generated voltage by the kicking operation is low and also the generation time is short, the delivery amount of the electromagnetic fuel pump 6 decreases. Further, since the fuel supply to the carburetor 9 is insufficient, there is the possibility that the startability of the engine 1 may drop. [0005] On the other hand, upon startup by the starter motor, since the battery voltage is in a sufficiently high state, also it is demanded to suppress the power supply to the electromagnetic fuel pump 6 to the necessary lowest level. In this manner, with a motorcycle which uses both of starting of an engine by means of a starter motor and starting of the engine by means of a kick pedal, it is desired to set a control method for an electromagnetic 43 fuel pump in accordance with each of the engine starting methods. [0006] Further, if the electromagnetic fuel pump 6 fails during running of the motorcycle, then since the control of the electromagnetic fuel pump 6 is stopped, the output power of the engine drops after the motorcycle runs in a usual manner over some distance with fuel remaining in the carburetor 9. Accordingly, also it is demanded to moderate the variation of the output power of the engine and control so that the user can recognize readily that the electromagnetic fuel pump 6 has failed. [0007] Therefore, an object of the present invention is: ® controlling an electromagnetic fuel pump suitable for a starting method depending upon starting of an engine by means of a starter motor or upon starting of the engine by means of a pick pedal; and ® coping with the failure with a control method for the engine set in advance when the electromagnetic fuel pump fails. [0008] [Means for Solving the Problems] In order to attain the object described above, according to claim 1, a control method for an electromagnetic fuel pump including an electromagnetic fuel pump for supplying fuel of a fuel tank to an engine, a starter motor starting apparatus for starting the engine with a starter motor which is fed from a battery, and a kick starting apparatus for starting the engine by a kicking operation and including a control section for controlling driving of the electromagnetic fuel pump, is characterized in that the control section has a first operation mode set when a battery voltage with which the starter motor can operate is detected, and a second operation mode set when a battery voltage with which the starter motor cannot operate is detected and different from the first operation mode, and operation of the fuel pump upon starting is controlled in one of the first operation mode and the second operation mode. [0009] Consequently, in a case wherein the engine is started by the kick starting apparatus and another case wherein the engine is started by the starter motor starting apparatus, preferable starting control of the electromagnetic fuel pump upon starting can be carried out with different control functions from each other, and while the engine startability by the kick starting apparatus is improved, electric power to be supplied to the fuel pump can be suppressed upon starting of the engine by the starter motor starting apparatus. [0010] According to claim 2, the control method for an electromagnetic fuel pump is characterized in that the first operation mode and the second operation mode are duty control wherein on/off of the power supply to the fuel pump are repeated. Since the on/off ratio of the duty control can be changed readily by operating the fuel pump by the duty control, the starting control method for the fuel pump can be set freely in accordance with the kick starting and the starter motor starting. [0011] According to claim 3, the control method for an electromagnetic fuel pump is characterized in that the second operation mode has a period of the on/off control shorter than that of the first operation mode. Consequently, the on/off period of the electromagnetic fuel pump becomes short, and the fuel supply amount to the carburetor can be increased. Accordingly, when there is no fuel in the carburetor, fuel can be filled into the carburetor rapidly, and the engine startability can be raised. [0012] According to claim 4, the control method for an electromagnetic fuel pump is characterized in that the second operation mode has an on time longer than that of the first operation mode. Since the battery voltage is low upon starting of the engine by the kick starting apparatus when the battery is consumed, if the on time of the electromagnetic fuel pump is set to a time longer than that in a normal state so that the stroke of a plunger of the electromagnetic fuel pump can be increased, then the fuel supply amount to the carburetor can be increased. Accordingly, when there is no fuel in the carburetor, fuel can be supplied rapidly into the carburetor, and the engine startability can be raised. [0013] According to claim 5, the control method for an electromagnetic fuel pump is characterized in that the control section includes an ignition control section which controls, when a failure of the fuel pump is detected, the speed of the engine to a speed equal to or lower than a predetermined speed and then stops ignition. For example, if the electromagnetic fuel pump fails during running of the motorcycle, then since the failure of the fuel pump is detected and the speed of the engine is controlled to a speed equal to or lower than the predetermined speed, the variation of the output power of the engine can be moderated, and the driver can recognize the failure of the electromagnetic fuel pump readily. [0014] According to claim 6, the control method for an electromagnetic fuel pump is characterized in that the ignition control section stops the ignition immediately when the speed of the engine when a failure is detected is equal to or lower than the predetermined speed. For example, when the engine speed is equal to or lower than the predetermined speed, if the electromagnetic fuel pump fails, then the ignition is stopped immediately so that the driver can recognize readily that the electromagnetic fuel pump has failed. [0015] [Mode for Carrying out the Invention] In the following, an embodiment of the present invention is described with reference to the accompanying drawings. It is to be noted that the drawings are each viewed in the direction of reference characters. 8/ [BRIEF DESCRIPTION OF THE DRAWINGS] [FIG. 13 FIG. 1 is a side elevational view of a motorcycle provided with an electromagnetic fuel pump according to the present invention. [FIG. 2] FIG. 2 is a plan view showing &n attached state of the electromagnetic fuel pump according to the present invention. [FIG. 3J FIG. 3 is a perspective view showing the attached state of the electromagnetic fuel pump according to the present invention. [FIG. 4] FIG. 4 is a perspective view of an engine to which fuel is supplied by the electromagnetic fuel pump according to the present invention. [FIG. 5] FIG. 5 is a sectional view of the electromagnetic fuel pump according to the present invention. [FIG. 6] FIGS. 6 (a) and 6(b) are operation diagrams illustrating operation of the electromagnetic fuel pump according to the present invention. [FIG. 7] FIG. 7 is a schematic view of a fuel supply system and the engine provided with the electromagnetic fuel 9 pump according to the present invention. [FIG. 8] FIG. 8 is a circuit diagram of a power supplying apparatus for supplying electric power to the electromagnetic fuel pump according to the present invention. [FIG. 9] FIG. 9 is a first operation diagram illustrating operation of the power supplying apparatus which supplies electric power to the electromagnetic fuel pump according to the present invention. [FIG. 10] FIG. 10 is a second operation diagram illustrating operation of the power supplying apparatus which supplies electric power to the electromagnetic fuel pump according to the present invention. [FIG. 113 FIG. 11 is a third operation diagram illustrating operation of the power supplying apparatus which supplies electric power to the electromagnetic fuel pump according to the present invention. [FIG. 12] FIGS. 12(a) and 12{b) are operation diagrams illustrating operation of the power supply to the electromagnetic fuel pump according to the present invention. [FIG. 13] FIG. 13 is an operation diagram illustrating a generated voltage boosting method according to the present invention. [FIG. 14] FIG. 14 is a first graph illustrating the generated voltage boosting method according to the present invention. [FIG. 15] FIG. 15 is a second graph illustrating the generated voltage boosting method according to the present invention. [FIG. 16] FIG. 16 is a third graph illustrating the generated voltage boosting method according to the present invention. [FIG. 17] FIG. 17 is a flowchart illustrating a starting operation method for the electromagnetic fuel pump according to the present invention. [FIG. 18] FIG. 18 is a first flowchart of the generated voltage boosting method according to the present invention. [FIG. 19] FIG. 19 is a second flowchart of the generated voltage boosting method according to the present invention. [FIG. 20] FIGS. 20(a) through 20(c) are operation diagrams illustrating a control method for the engine provided with the electromagnetic fuel pump according to the present invention. [FIG. 21) FIG. 21 is a plan view of the motorcycle provided with the electromagnetic fuel pump according to the present invention. [FIG. 22] FIG. 22 is a perspective view of the engine of the motorcycle provided with the electromagnetic fuel pump according to the present invention. [FIG. 23] FIG. 23 is a perspective view of a rear portion of the motorcycle provided with the electromagnetic fuel pump according to the present invention. [FIG. 24] FIG. 1 is a side elevational view of a motorcycle provided with an electromagnetic fuel pump according to the present invention. The motorcycle 10 is a scooter type vehicle wherein a starter switch 12 is attached to a handle bar 11; a main switch 13 serving also as a handle lock apparatus and including a magnet shutter key provided at a key insertion opening thereof is arranged below the handle bar 11; an engine control unit 16 for ignition control (ignition by a CDI apparatus which is hereinafter described) and power control of an engine 15, a radiator reserve tank 157 and a battery 18 are disposed in a rear cover 14 which covers a lower rear portion of a seat and covers over a rear wheel; a kick pedal 23 is attached to a unit swing engine 2 2 formed from the engine 15 and a belt converter non-stage transmission 21 with a centrifugal clutch; and a fuel tank 25 and an electromagnetic fuel pump 26 for supplying fuel from the fuel tank 25 to the engine 15 are disposed below a floor step 24. It is to be noted that reference numerals 31 and 32 denote a headlamp and a tail lamp, respectively, as lamp type loads. The power unit 22 includes a starter motor serving as a starter motor starting apparatus and an ACG starter 33 (not shown, hereinafter described.) serving also as a generator, which are provided at a side portion on the interior side. [0016] Here, reference character 25a denotes a fuel lid, 25b a fuel cap with a lock for opening the fuel lid 25a forwardly upwards to allow fuel to be supplied into the fuel tank 25, 120 a mirror, 121 a meter panel, 122 a front side handle bar cover, 12 3 a front winker, 124 a brake lever, 125 a rear side handle bar cover, 126 a front cover, 127 a leg shield for holding a head pipe 134 therebetween and covering the front cover 126, 128 a horn provided in the front cover 126, 131 a front fork, 132 a front wheel, 133 a front fender which is turned together with the front fork 131, 134 a head pipe, 135 a body frame, 13 5a a die-cast front frame forming a front portion of the body frame 135 and having the head pipe 134 formed integrally thereon, 13 5b a die-cast rear frame forming a rear portion of the body frame 135 and connected to the die-cast front frame 135a by a connecting portion 135c, 136 a pair of left and right floor side covers, 137 an undercover for covering and protecting a bottom portion of the fuel tank 25, 141 an exhaust pipe, 142 a pair of left and right engine hangers, 143 a radiator provided at the right end of a crankshaft 14 15a of the engine 15, 144 an air cleaner provided on the left side of the vehicle body, 145 a muffler provided on the right side of the vehicle body, 146 a main stand, 147 a seat which covers a luggage box 151 for opening and closing motion, 148 a seat lower cover for covering a front portion around the seat, 152 a helmet, 153 a pair of left and right side covers, 154 a rear winker, 155 a rear fender, 156 a rear cushion unit, and 158 a rear wheel. [0017] FIG. 2 is a plan view showing an attached state of the electromagnetic fuel pump according to the present invention and shows that, in a space between the fuel tank 2 5 and a cylinder head 308 which is hereinafter described, the fuel pump 26 is attached to an upper face of the under cover 137 by nuts 301, 301 and a fuel filter 34 is connected to a portion of the fuel pump 2 6 on the fuel tank 25 {refer to FIG. 1) side by a hose 302. It is to be noted that the leftward direction of the figure (direction of a blank arrow mark) is the forward (front) direction of the vehicle. Consequently, fuel is fed from the left side to the right side of the vehicle body from a conduit 321 led out from the right side of the fuel tank 25 by the fuel 15 filter 34 and the fuel pump 26 and flows from the fuel pump 2 6 to a check valve 35 at a rear upper location along a pipe of the hose 303. In this manner, effective utilization of the dead space and simple piping can be achieved. [0018] FIG. 3 is a perspective view showing an attached state of the electromagnetic fuel pump according to the present invention and shows a state wherein the fuel pump 2 6 is viewed from an obliquely forwardly upward location to the engine 15. Reference numeral 35 denotes a check valve for allowing fuel to flow only in one direction from the fuel pump 2 6 side to a carburetor 36 {refer to FIG. 1) side, and the check valve 35 is connected to the fuel pump 2 6 by the hose 303. The fuel pump 26 is positioned at a lower portion of the right side of the cylinder head which is hereinafter described, and a fuel system including the fuel pump 26 is covered with and protected by a shade provided between the fuel pump 2 6 and the engine 15. It is to be noted that reference numeral 106 denotes an ignition coil, and 3 04 is a shade provided among a head cover 311, the fuel pump 26, and fuel filter 34 for protecting the fuel system. [0019] FIG. 4 is a perspective view of the engine to which fuel is supplied by the electromagnetic fuel pump according to the present invention. The engine 15 includes a crankcase 306, a cylinder block 307 attached to a front portion of the crankcase 306, a cylinder head 308 attached to a front portion of the cylinder block 307, a head cover 311 for covering an end portion of the cylinder head 308, a carburetor 36 disposed above the crankcase 3 06, an intake pipe 3 7 extending from the carburetor 3 6 to the cylinder head 308 side, an intake manifold 313 connected to the intake pipe 3 7 and having the cylinder head 308 attached thereto, a connecting tube 314 connected from the carburetor 3 6 to the air cleaner 144 (refer to FIG. 1), a plug cap 316 connected to the ignition coil 106 by a high tension cable 315, an ignition plug 38 on which the plug cap 316 is placed, and a radiator 143 attached to a side face of the crankcase 306. It is to be noted that reference numeral 317 denotes a breather tube extending from the head cover 311 to the air cleaner 144 side. [0020] In particular, the engine 15 is disposed substantially horizontally such that the cylinder block 3 07, cylinder head 3 08 and head cover 311 are exposed between the luggage box 151 and the fuel pump 2 6 shown in FIG. 1. The engine hangers 142 include a pair of left and right hanger plates 142a and 142b connected to each other by a pipe 142c. [0021] FIG. 5 is a sectional view of the electromagnetic fuel pump according to the present invention. The fuel pump 26 includes a case 26a having a suction port 26b for fuel, a check valve 26c attached to the exit side of the suction port 26b, a cylindrical spool 26d inserted in the case 26a such that it surrounds the check valve 26c, a coil 26f disposed on an outer circumferential face side of the spool 26d with a collar 26e interposed therebetween, a bottomed cylindrical plunger 26g inserted for movement in the spool 26d, and a spring 26h for pressing the plunger 2 6g toward a lid portion 26j side of the case 26a, and a delivery port 26k is provided in the lid portion 26j. It is to be noted that reference character 26n denotes a seal member for sealing between the collar 26e and the lid portion 26j, 26p a seal member for sealing between the spool 26d and the lid portion 26j, 26q a first chamber in the spool 26d on the suction port 26b side with respect to the plunger 26g, and 26r a second chamber in the spool 26d on the delivery port 26k side with respect to the plunger 2 6g. The check valve 26c is a one-way valve for allowing fuel to flow only from the suction port 2 6b side to the first chamber 26q side. The plunger 2 6g is a member having a plurality of through-holes 26s formed in a bottom portion thereof. [0022] FIGS. 6(a) and 6(b) are operation diagrams illustrating operations of the electromagnetic fuel pump according to the present invention. FIG. 6(a) shows a state wherein the coil 26f (refer to FIG. 3) is energized. When the coil 26f is energized, the plunger 2 6g is moved in the direction of an arrow mark ® in the spool 2 6d, and besides, since the check valve 2 6c is closed, fuel in the first chamber 26q flows to the second chamber 26r through the through-holes 26s of the plunger 26g as indicated by an arrow mark ®. [0023] FIG. 6(b) shows a state wherein the energization of the coil 26f is stopped. 19 When the energization of the coil 26f is stopped from the state of FIG. 6(a), the plunger 26g is returned to its original position as indicated by an arrow mark (3) by resilient force of the spring 2 6h. [0024] Consequently, fuel in the second chamber 26r is delivered from the delivery port 2 6k as indicated by an arrow mark ®, and the check valve 26c is opened and the fuel flows from the suction port 2 6b into the first chamber 26q as indicated by arrow marks © and ©. As the energization (on) and the stop of the energization (off) of the coil 26f are repeated in this manner, fuel can be intermittently fed from the fuel tank 25 (refer to FIG. 2) side to the carburetor 36 (refer to FIG. 2) side. [0025] FIG. 7 is a schematic view of the fuel supply system and the engine provided with the electromagnetic fuel pump according to the present invention and shows that the fuel filter 34 is connected to the fuel tank 25 by the conduit 321 and the fuel pump 26 is connected to the fuel filter 34 by the hose 302 (refer to FIG. 2) not shown while the check valve 3 5 is connected to the fuel pump 2 6 by the hose 3 03 and is connected to the carburetor 3 6 by a hose 322. The carburetor 36 is also connected to the cylinder head 308 of the engine 15 by the intake pipe 37 and the intake manifold 313. [0026] Fuel in the fuel tank 2 5 flows, when the fuel pump 26 is rendered operative, from the fuel pump 2 6 to the carburetor 3 6 through the fuel filter 34, fuel pump 2 6 and check valve 35, and atomized and mixed with air by the carburetor 36 to form air fuel mixture. The air fuel mixture flows into the combustion chamber of the engine 15 through the intake pipe 37 and the intake manifold 313, and is ignited by a spark generated by the ignition plug 38 and is burnt. [0027] Since lower faces of the fuel filter 34, fuel pump 26 and unit swing engine 22 are disposed at a substantially equal height to that of a bottom face of the fuel tank 25 as viewed in side elevation, a counter-flow of fuel from the fuel pump 2 6 to the fuel tank 2 5 can be prevented and fuel can be held in the fuel pump 2 6, and the fuel can be fed rapidly into the carburetor 36 when the engine is started. [0028] Further, the conduit 321 from the fuel tank 25 to the fuel filter 34 extends upwardly once from the position substantially of the bottom face of the fuel tank 25 and is folded back in a U-shaped configuration, and then extends from the position substantially of the bottom face of the fuel tank 2 5 again and is connected to the fuel filter 34. Therefore, a counter-flow of fuel can be prevented further, and a good startability of the engine can be assured. [0029] Furthermore, since the check valve 35 is interposed between the hoses 3 03 and 322 which extend substantially rearwardly upwards of the vehicle from the fuel pump 2 6 to the carburetor 36, fuel can be held also between the carburetor 3 6 and the check valve 3 5, and fuel to be supplied to the carburetor 3 6 when the engine is started is assured and a counter-flow of fuel is prevented. [0030] Here, reference character 15a denotes a crankshaft, 21a a driven shaft of the belt converter non-stage transmission 21 with a centrifugal clutch, 21c a belt converter, and 21c a rear axle. Rotation of the crankshaft 15a is transmitted through the belt converter 21b and then through the centrifugal clutch of the driven shaft to the driven shaft 21a and thereafter drives the rear axle 21c through a gear train. [0031] FIG. 8 is a circuit diagram of a power supplying apparatus for supplying electric power to the electromagnetic fuel pump according to the present invention. The power supplying apparatus 4 0 is formed from the battery 18, a battery disconnection relay 4 2 connected to the battery 18 through a main fuse 41, a starter relay 43 connected to the battery disconnection relay 4 2 and the battery 18, an ACG starter 33 connected to the starter relay 4 3 through a boost rectification circuit 44, FET (Field Effect Transistor) driving means 53 for driving FETs 45 to 50 which form the boost rectification circuit 44, an oscillator 54 for supplying a pulse signal for a chopper {a chopper is to convert DC current into AC current, amplify (boost) the AC current in this state and then rectify the AC output back into DC current) to the FET driving means 53 and control means 55 serving as a control section, the main switch 13 connected to the battery 18 side and the ACG starter 33 side through a first diode 56 and a second diode 57, respectively, the starter switch 12 connected to the main switch 13 and the control means 55, FETs 62 and FET 63 both connected to a general load 61 and the fuel pump 26, respectively, to which electric power is supplied from the battery disconnection relay 42 side through a sub fuse 58, and an FET 64 connected to the starter relay 43. [0032] The starter switch 12 includes a first fixed contact 66 connected to the main switch 13, a second fixed contact 67 connected to the control means 55, and a movable contact 68 which can be connected to the first and second fixed contacts 66 and 67 or can be disconnected from the first and second fixed contacts 66 and 67. [0033] The main switch 13 includes a fixed contact 71 connected to the control means 55, a movable contact 72 which can be connected to or disconnected from the fixed contact 71. The main switch 13 is also connected to the battery 18 and the ACG starter 33, and an antitheft switch section 73 connected to the movable contact 72. [0034] The antitheft switch section 73 is connected to an antitheft apparatus not shown, and exhibits an off state when the movable contact 72 of the main switch 13 is connected to the fixed contact 71 (on) , but exhibits an on state when the movable contact 72 is disconnected from the fixed contact 71 (off). [0035] The ACG starter 33 has functions as both of a starter motor and a three-phase AC generator. When the ACG starter 33 acts as a starter motor, the stator coil 33a is energized from the battery 18 to rotate the crankshaft 15a. However, when the ACG starter 33 acts as a three-phase AC generator (ACG), an output is extracted from stator coils 33a. When the ACG starter 33 is used as a starter motor, it operates with a battery voltage equal to or higher than a predetermined voltage v3. [0036] The battery disconnection relay 4 2 includes a switch section 78 formed from a fixed contact 76 connected to the main fuse 41 and a movable contact 77 which can be connected to or disconnected from the fixed contact 76 and is connected to the starter relay 43, and a coil 81 for switching on or off the switch section 78. The switch section 7 8 exhibits an off state when the coil 81 is not energized. [0037] The starter relay 43 includes a switch section 85 having a first fixed contact 82 connected to the battery disconnection relay 42, a second fitted contact 83 connected to the battery 18, and a movable contact 84 which can be connected to or disconnected from the- first and second fixed contacts 82 and 83 and is connected to the boost rectification circuit 44, and a coil 86 for changing over the connection of the movable contact 84 to the first and second fixed contact 82. The movable contact 84 is connected to the first fixed contact 82 when the coil 86 is not energized, but the movable contact 84 is connected to the seconds fixed contact 83 when the coil 86 is energized. [0038] The boost rectification circuit (power section) 44 is formed from the FETs 45 to 50 described above, diodes 91 to 96 which are parasitic diodes connected between the drains and the sources of the FETs 4 5 to 50, respectively, and a capacitor 101 connected between output terminal sections 97 and 98. The diodes 91 to 96 form a three-phase full wave rectification circuit, and the FETs 45 to 50 form a switching circuit for a chopper. The switch circuit functions as a driver when the ACG starter 33 operates as a starter motor, but functions as a regulator when the ACG starter 33 operates as an ACG. [0039] The FETs 45 to 50 and the FETs 62 to 64 are P channel MOS type FETs, in each of which the drain current which flows between the drain and the source is controlled by a gate voltage applied between the gate and the source. [0040] The FET driving means 53 receives a pulse signal from the oscillator 54 or the control means 55, and supplies a driving signal Sd of a rectangular waveform to the gates of the FETs 45 to 50 in synchronism with the frequency of the pulse signal. [0041] The oscillator 54 is started up when the voltage supplied from the battery 18 or the ACG starter 3 3 reaches vl, and generates oscillation pulses having a predetermined amplitude, a predetermined pulse width, and a predetermined time interval, that is, the oscillator 54 generates an oscillation pulse signal with the oscillator startup voltage vl or more. [0042] The control means 55 controls on or off of the FETs 62 to 64 as switches, and includes a central processing unit (CPU) 55a. The CPU 55a includes a clock generator not shown which generates periodical pulses of a fixed interval of time. [0043] The CPU 55a is started up when the voltage supplied from the battery 18 or the ACG starter 33 reaches v2 and generates pulses (the pulses are referred to here as "CPU pulses") having a predetermined amplitude, a predetermined pulse width, and a predetermined time interval based on a pulse signal of the clock generator, that is, the CPU 55a generates a CPU pulse signal with a voltage equal to or higher than the startup voltage v2 . [0044] Further, while the CPU 55a generates the CPU pulse signal only for a predetermined time after the generation of the CPU pulse signal is started, if an ignition pulser signal from an ignition pulser signal generation apparatus not shown is detected within a predetermined time, generation of the CPU pulse signal is also continued until the engine speed reaches a predetermined value or more or the battery voltage reaches a predetermined value or more after the predetermined time. Then, when the engine speed becomes a predetermined value or less or when rotation of the engine stops, the CPU 55a ends generation of the CPU pulse signal. [0045] The control means 55 controls the gate voltage to each of the FETs 62 to 64 to control on or off between the drain and the source of the FET 62 to 64. Further, the control means 55 generates also a control signal for operating the CD! apparatus 17 in the engine control unit 16. [0046] The CDI apparatus 17 generates electricity with an ignition coil (not shown) wound in the ACG starter 33, rectifies the electricity by means of a diode, and temporarily stores it into a capacitor for ignition. Then, the CDI apparatus 17 switches a thytistor into an on state by applying an electric signal to the gate of the thyristor in an off state connected to the capacitor for ignition to discharge electric powet stored in the capacitor for ignition. The discharged current is supplied to the primary coil 107 of the ignition coil 106 to generate a high voltage in the secondary coil 108 to generate a spark at the ignition plug 38. [0047] The first diode 56 allows current to flow only in a direction from the battery 18 to th$ main switch 13 side, but does not allow current to flow in the other direction from the ACG starter 33 to the battery 18. 29 The second diode 57 allows current to flow only in a direction from the ACG starter 33 to the main switch 13 side, but does not allow current to flow in the other direction from the battery 18 to the ACG starter 33. In short, the first and second diodes 56 and 57 allow current of a fixed direction to flow to the control means 55 in order to protect the control means 55. [0048] The general load 61 is an electric load except a fuel supplying system load of the fuel pump 26 and so forth and an ignition system load of the CDI apparatus 17, the ignition plug 38 and so forth. The general load 61 mainly includes lamp loads such as the head lamp 31, the tail lamp 32, a turn signal lamp, and instrument lights, and a horn. The diodes 103 to 105 are parasitic diodes of the FETs 62 to 64. [0049] Here, a generation voltage boost apparatus 110 is composed of the boost rectification circuit 44, FET driving means 53, oscillator 54, and control means 55. Further, a power control apparatus 111 is composed of the FETs 62 to 64 and the control means 55. The generation voltage boost apparatus 110, power control apparatus 111 and CDI apparatus 17 are provided in the engine control unit 16. [0050] Operation of the above-described electric power supplying apparatus 4 0 is described below First, a starting method of the engine (startup by the starter motor and startup by the kick pedal) is described. FIG. 9 is a first operation diagram illustrating operation of the electric power supplying apparatus which supplies electric power to the electromagnetic fuel pump according to the present invention and description is given of operation upon starter motor starting up wherein the ACG starter 33 is used as a starter motor. When the battery voltage is sufficiently high, that is, when the battery voltage is equal to or higher than a predetermined voltage v3 (for example, 8 V), the main switch 13 is switched on as indicated by ® and electric power is supplied from the battery 18 to the control means 55 as indicated by an arrow mark ©. [0051] The control means 55 sends a drive signal da to the FET 62 and sends another drive signal db to the FET 63 to switch on the FETs 62 and 63. Consequently, current flows as indicated by an arrow mark © through the coil 81 of the battery disconnection relay 42, and the switch section 7 8 of the battery disconnection relay 42 is switched on as indicated by @. As a result, the battery 18 supplies electric power to the fuel pump 26 and the general load 61 through the main fuse 41, battery disconnection relay 42 and sub fuse 58 as indicated by an arrow mark ©. [0052] Then, if the starter switch 12 is switched on as indicated by ©, then current flows through the starter switch 12 to the control means 55, and the control means 5 5 sends a drive signal dc to the FET 6 4 to turn on the FET 64 . Consequently, current flows through the coil 8 6 of the starter relay 43 as indicated by an arrow mark © to change over the movable contact 84 of the starter relay 43 from the first fixed contact 82 to the second fixed contact 83 as indicated by ®, thereby to supply electric power from the battery 18 to the ACG starter 3 3 through the starter relay 43 as indicated by an arrow mark ®. Consequently, the ACG starter 33 is activated as a starter motor and starts up the engine. [0053] FIG. 10 is a second operation diagram illustrating 32 operation of the electric power supplying apparatus which supplies electric power to the electromagnetic fuel pump according to the present invention and description is given of operation upon kick starting up for activating the engine by treading down the kick pedal. When the battery voltage is not sufficiently high to operate the starter motor, that is, when the battery voltage is equal to or lower than the predetermined voltage v3, if the main switch 13 is switched on as indicated by ® and the kick pedal is trodden down, then the rotor (not shown) of the ACG starter 33 connected to the kick pedal is rotated (refer to an arrow mark ®) and starts power generation. Then, the generated AC output is boosted and rectified by the boost rectification circuit 4 4 and is supplied to the control means 55 as indicated by an arrow mark ®. The control means 55 sends a control signal to the CDI apparatus 17 (refer to FIG. 8) so that a spark is generated at the ignition plug 38. [0054] Further, the control means 5 5 sends a drive signal da to the FET 62 to effect switching on between the drain and the source of the FET 62, that is, to switch on the FET 62. Consequently, current flows as indicated by an 33 arrow mark ® from the output terminal section 97 side to the fuel pump 26 through the movable contact 84 and first fixed contact 82 of the starter relay 43 and the sub fuse 5 8. Consequently, the fuel pump 26 is driven to supply fuel to the engine. [0055] In this manner, the control means 55 does not send, upon kick starting, a drive signal to the FET 63 to keep the FET 63 off, thereby to switch off the battery disconnection relay 4 2 to disconnect the battery 18 from the ACG starter 33 and not to supply electric power from the ACG starter 33 to the general load 61. [0056] FIG. 11 is a third operation diagram illustrating operation of the electric power supplying apparatus which supplies electric power to the electromagnetic fuel pump according to the present invention and description is given of operation after the engine is started up by the starter motor startup described hereinabove with reference to FIG. 9 or by the kick starting described hereinabove with reference to FIG. 10. Electric power generated by the ACG starter 3 3 is supplied to the control means 5 5 through the boost rectification circuit 44 as indicated by an arrow mark CD. The control means 55 sends a control signal to the CDI apparatus 17 to generate a spark at the ignition plug 38. [0057] The control means 55 sends a drive signal da to the FET 62 to switch on the FET 62 and sends another drive signal db to the FET 63 to switch on the FET 63. Consequently, current flows to the coil 81 of the battery disconnection relay 42 as indicated by an arrow mark © to switch on the switch section 78 of the battery disconnection relay 42. As a result, current flows from the ACG starter 33 to the battery 18 through the starter relay 43, battery disconnection relay 42 and main fuse 41 as indicated by an arrow mark @ to charge the battery 18. Further, electric power is supplied from the starter relay 43 side to the fuel pump 26 and the general load 61 through the sub fuse 58 as indicated by an arrow mark ©. [0058] FIGS. 12(a) and 12(b) are operation diagrams illustrating operation of electric power supply to the electromagnetic fuel pump according to the present invention and views illustrating a pump driving voltage for driving the fuel pump 26 {refer to FIG. 8). While it is described with reference to FIGS. 9 and 10 that the control means 55 sends a driving signal da to the FET 62 to turn on the FET 62, more particularly the control means 55 sends an intermittent driving signal da to the FET 62 to repeat turning on/off of the FET 62. In the following, a variation of the pump driving voltage corresponding to the turning on/off is described. It is to be noted that the pump driving voltage represents a voltage difference between a + (plus) terminal and a - (minus) terminal provided on the fuel pump 26 to allow the fuel pump 26 to receive supply of electric power. [0059] FIG. 12(a) is a graph illustrating the pump driving voltage where the battery voltage VB is equal to or higher than the predetermined voltage v3 (that is, VB ^ v3), and the axis of ordinate indicates the pump driving voltage DV {whose unit is V) and the ignition pulser signal and the axis of abscissa indicates the time t (whose unit is sec). Simultaneously, when the main switch is switched on (the time t is zero), the pump driving voltage DV changes to the H level (the FET 62 (refer to FIG. 6) is in an on state. The pump driving voltage DV is, for example, 12 V) , and when the duration of the H level, that is, the on time tc {for example, tc = 0.010 sec), elapses, the pump driving voltage DV changes to the L level (the FET 62 is in an off state. The pump driving voltage DV is 0 (zero) V) . [0060] Then, when the time t elapses by a time tcs (for example, tcs = 0.280 sec) from zero, the pump driving voltage DV changes to the H level again, and when the on time tc elapses, the pump driving voltage DV changes to the L level (0 (zero) V). The pump driving voltage DV thereafter changes repetitively in this manner until the time t reaches a time tl {for example, 5 sec) from zero. In this manner, the form of the pump driving voltage is duty control wherein on/off of the power supply to the fuel pump are repeated. [0061] Here, where the time tcs is the period of the duty control and the rate of the on time tc to the period tcs is fal (that is, fal = tc/tcs), then fal is a duty factor. The driving voltage form from 0 to tl of the time t is referred to as initial operation mode upon the starter motor starting. [0062] After the initial operation mode, the starter motor is started up at time t2, and simultaneously when the control means detects an ignition pulser signal from the ignition pulser signal generation apparatus at time t3, the pump driving voltage DV changes to the H level. Then, after the H level is kept for the time tc, the pump driving voltage DV changes to the L level. Thereafter, similarly as in the initial operation mode, the H level and the L level are repeated till time t4 at which the engine is started, and also the engine is started, the change is repeated similarly. The driving voltage form from t3 to t4 of the time t is then referred to as continuous operation mode upon the starter motor starting. It is to be noted that, in this instance, even when the engine is started by the kick starting, similar control is performed. [0063] FIG. 12(b) is a graph illustrating the pump driving voltage when the battery voltage VB is equal to or higher than the voltage v2 but lower than the predetermined voltage v3 (that is, v2 S VB The main switch is switched on (the time t is zero). and the kicking is started at time t6. Consequently, if the control means detects an ignition pulser signal, for example, at time t7, then the pump driving voltage DV changes to the H level (the FET 62 (refer to FIG. 7) is in an on state. The pump driving voltage DV is, for example, 12 V), and when the duration of the H level, that is, the on time tk (for example, tk = 0.015 sec), elapses, the pump driving voltage DV changes to the L level (the FET 62 is in an off state. The pump driving voltage DV is 0 V). [0064] Then, the pump driving voltage DV changes to the H level again when the time tks (for example, tks = 0.092 sec) elapses after time t7, and when the on time tk further elapses, the pump driving voltage DV changes to the L level, and the H level and the L level are thereafter repeated alternately. Also in this instance, the form of the pump driving voltage is duty control wherein on/off of the power supply to the fuel pump are repeated. [0065] Here, if the time tks is a period of the duty control and the rate of the on time tk to the period tks is represented by fa2 (that is, fa2 = tk/tks), then fa2 is a duty factor. The driving voltage form from t7 to t8 of the time t in this instance is referred to as continuous operation mode upon the kick starting. [0066] Thereafter, when the engine is started at time t8, the continuous operation mode which has continued after time t7 comes to an end, and thereafter, similarly as illustrated in FIG. 12(a), the power supply is changed over to that of the on time tc and the period tcs, whereafter this is maintained. [0067] Upon this kick starting, if the engine speed N upon the kicking operation is equal to or higher than a preset engine speed Nst (for example, 1,200 rpm), then the continuous operation mode upon the kick starting illustrated in FIG. 12(b) is not carried out, but the continuous operation mode upon the starter motor starting illustrated in FIG. 12(a) is carried out. [0068] On the other hand, where the battery voltage VB is VB described to carry out feeding to the fuel pump described with reference to FIG. 12(a) or 12(b). Here, the initial operation mode and the continuous operation mode illustrated in FIG. 12 (a) are commonly referred to as first operation mode of the fuel pump, and the continuous operation mode illustrated in FIG. 12(b) is referred to as second operation mode of the fuel pump. [0069] As described hereinabove with reference to FIGS. 7, 8, 12(a), and 12(b), according to the present invention, first of all, a control method for an electromagnetic fuel pump 26 including an electromagnetic fuel pump 2 6 for supplying fuel of a fuel tank 25 to an engine 15, a starter motor starting apparatus for starting the engine 15 with an ACG starter 33 which is fed from a battery 18, and a kick starting apparatus 23 for starting the engine 15 by a kicking operation and including control means 5 5 for controlling driving of the electromagnetic fuel pump 26, is characterized in that the control means 55 has a first operation mode set when a battery voltage VB with which the ACG starter 33 can operate is detected, and a second operation mode set when a battery voltage VB with which the ACG starter 33 cannot operate is detected and different from the first operation mode, and operation of the fuel pump 2 6 upon starting is controlled in either first operation mode or second operation mode. [0070] Consequently, in a case wherein the engine 15 is started by the kick starting apparatus 23 and another case wherein the engine 15 is started by the starter motor starting apparatus, preferable starting control of the electromagnetic fuel pump 26 upon starting can be carried out with different control functions from each other, and while the engine startability by the kick starting apparatus 2 3 when fuel is not present in the carburetor 36 is improved, electric power to be supplied to the fuel pump 2 6 can be suppressed upon starting of the engine by the starter motor starting apparatus. [0071] Secondly, according to the present invention, the control method for an electromagnetic fuel pump is characterized in that the first operation mode and the second operation mode are duty control wherein on/off of the power supply to the fuel pump 26 are repeated. Since the on/off ratio can be changed readily by operating the fuel pump 2 6 by the on/off control, the starting control method for the fuel pump 26 can be set freely in accordance with the kick starting and the starter motor starting. [0072] Thirdly, according the present invention, the control method for an electromagnetic fuel pump is characterized in that the second operation mode has a period of the on/off control shorter than that of the first operation mode, that is, the period tks The on/off period of the electromagnetic fuel pump 2 6 becomes short, and the fuel supply amount to the carburetor 36 can be increased. Accordingly, when there is no fuel in the carburetor 36, fuel can be filled into the carburetor 36 rapidly, and the engine startability can be raised. [0073] Fourthly, according to the present invention, the control method for an electromagnetic fuel pump is characterized in that the second operation mode has an on time longer than that of the first operation mode, that is, tk > tc, and (tk/tks) > (tc/tcs). Since the battery voltage is low upon starting of the engine by the kick pedal 23 when the battery is consumed, the plunger of the electromagnetic fuel pump 2 6 can be moved with a maximum stroke, and by setting an on time longer than that in a normal state, the fuel supply amount to the carburetor 36 can be increased. Accordingly, when there is no fuel in the carburetor 36, fuel can be supplied rapidly into the carburetor 36, and the engine startability can be raised. [0074] In the following, a method of boosting the generated voltage by the AC generator is described. FIG. 13 is an operation diagram illustrating the generated voltage boosting method according to the present invention. First, the main switch 13 is switched on. For example, if the battery voltage VB (that is, VB Consequently, the ACG starter 33 is rotated to start generation of electric power. [0075] Then, the AC power generated by the ACG starter 33 is three-phase full-wave rectified by the boost rectification circuit 44 so that DC current is outputted between the output terminal portions 97 and 98. The voltage of the DC output is applied to the 44 oscillator 54 and the control means 5 5 through the main switch 13. [0076] If the voltage described above is lower than the vl of the oscillator 54, then the kick pedal is repetitively trodden down to continue generation of electric power by the ACG starter 33. Consequently, the engine speed, that is, the speed of the AC generator, increases, and the generated voltage rises gradually. Then, when the generated voltage reaches the startup voltage vl of the oscillator 54 {the battery voltage is equal to vl), the oscillator 5 4 starts generation of an oscillation pulse signal Pb. [0077] As a result, the oscillation pulse signal Pb is applied to the FET driving means 53, and the FET driving means 5 3 applies a driving signal Sd in the form of a rectangular waveform of the same phase with a higher frequency than the AC output frequency of the ACG starter 33 to the gates of the FETs 45 to 50. Consequently, since AC current of a high voltage is generated in each of the stator coils 33a, and therefore, the AC currents are full-wave rectified by means of the diodes 91 to 96 and then smoothed by the capacitor 101. In other words, chopping is performed with the oscillation pulse signal Pb by the boost rectification circuit 44. [0078] Then, if the DC voltage after the rectification and the smoothing reaches a startup voltage v2 {the battery voltage is equal to v2) of a CPU 55a higher than the startup voltage vl of the oscillator 54, then the CPU 5 5a sends a pulse stopping signal Sp to the oscillator 54 to cause the oscillator 54 to end the generation of the oscillation pulse signal Pb and starts generation of a CPU pulse signal Pc. As a result, the CPU pulse signal Pc is applied to the FET driving means 5 3, and chopping is performed again by the boost rectification circuit 44 to further raise the output voltage between the output terminal portions 97 and 98. [0079] Then, if the output voltage between the output terminal portions 97 and 98 reaches a predetermined voltage v3 {the battery voltage is equal to v3), then the CPU 55a stops the generation of the CPU pulse signal Pc. When the output voltage becomes high in this manner, upon starting of the engine, a sufficiently high voltage can be supplied to the fuel pump 27 which is the fuel supply system load and the control means 55 which operates the ignition system load, and the startability of the engine can be improved. [0080] The reason why the generation of the oscillation pulse signal Pb by the oscillator 54 is ended with the voltage v2 and the generation of the CPU pulse signal Pc by the CPU 55a is ended with the voltage v3 is that, for example, if it is assumed that vl = 3 V, v2 = 6 V and v3 = 8 V, then the oscillator 54 operates most efficiently within a range from 3 to 6 V and the CPU 5 5a operates most efficiently within another range from 6 to 8 V. [0081] FIG. 14 is a first graph illustrating the generated voltage boosting method according to the present invention when the battery voltage VB upon starting of the engine (if the battery and the AC generator are connected to each other upon starting of the engine, the battery voltage and the generated voltage of the AC generator are equal to each other) is 0 = VB 47 signal and CPU pulse generation signal, and the axis of abscissa indicates the time T (whose unit is msec). The oscillation pulse generation signal and the CPU pulse generation signal represent that, when they have the L level, the oscillator or the CPU does not generate the oscillation pulse signal or the CPU pulse signal, but when they have the H level, the oscillator generates the oscillation pulse signal and the CPU generates the CPU pulse signal. First, the main switch is switched on at time tl, and the kick pedal is trodden down at time t2 to start kicking. [0082] Consequently, the engine speed N gradually rises, and as the engine speed N rises, the battery voltage VB gradually becomes high as a result of generation of electric power by the AC generator. At time t3, the battery voltage reaches vl which is the startup voltage of the oscillator, and the oscillation pulse generation signal changes from an off state (the L level) to an on state (the H level), that is, the oscillator starts generation of the oscillation pulse signal. [0083] The generated voltage is boosted with the oscillation pulse signal, and the battery voltage VB of the battery charged with the generated voltage further rises. Then, when the battery voltage VB reaches VB = v2 (for example, v2 = 6 V) which is the startup voltage of the CPU, the oscillation pulse generation signal changes to an off state (the L level) and the CPU pulse generation signal changes from an off state (the L level) to an on state (the H level), that is, the CPU causes the generation of the oscillation pulse signal to be ended and starts generation of the CPU pulse signal. [0084] At a point of time when the CPU pulse generation signal changes to an on state, the timer is started up, that is, the timer begins to increase its count value from the elapsed time t = 0. Then, if an ignition pulser signal is detected before the time t becomes equal to a predetermined time ts, the CPU continues the generation of the CPU pulse signal also after the predetermined time ts. [00853 When the engine speed N reaches N = nl (for example, 1,600 rpm) at time t7 after the engine is started at time t6, the CPU ends the generation of the CPU pulse signal. Here, if the battery voltage VB reaches VB = v3 before the engine speed N reaches N = nl, then the CPU ends the generation of the CPU pulse signal. [0086] FIG. 15 is a second graph illustrating the generated voltage boosting method according to the present invention when the battery voltage VB upon starting of the engine is vl ^ VB First, if the main switch is switched on at time tl, then since the battery voltage VB is higher than vl which is the startup voltage of the oscillator, the oscillator starts generation of the oscillation pulse signal simultaneously with the switching on of the main switch. Thereafter, the kick pedal is trodden down at time t2 to start kicking. [0087] Consequently, the engine speed N gradually rises, and as the engine speed N rises, the battery voltage VB gradually becomes higher as a result of generation of electric power by the AC generator. When the battery voltage VB reaches VB = v2 which 50 is the starting voltage of the CPU at time tlO, the CPU causes the oscillator to end the generation of the oscillation pulse signal and starts generation of the CPU pulse signal. [0088] At a point of time when the generation of the CPU pulse signal is started, the timer is started up (the elapsed time t = 0). Then, if the CPU detects an ignition pulser signal before the time t becomes equal to the predetermined time ts, then the CPU continues the generation of the CPU pulse signal also after the predetermined time ts. When the battery voltage VB reaches VB = v3 at time tl2, the CPU ends the generation of the CPU pulse signal. [0089] Now, the generated voltage boosting method when the battery voltage VB is v2 ^ VB FIG. 16 is a third graph illustrating the generated voltage boosting method according to the present invention when the battery voltage VB upon starting of the engine is v2 = VB 51 First, if the main switch is switched on at time tl, then since the battery voltage VB is higher than vl which is the startup voltage of the oscillator, the oscillator starts generation of the oscillation pulse signal simultaneously with the switching on of the main switch. [0090] Since the battery voltage VB is higher than v2 which is the startup voltage of the CPU as well, the CPU causes the oscillator to end the generation of the oscillation pulse signal and starts generation of the CPU pulse signal after a predetermined time tb from the start of the generation of the oscillation pulse signal. Here, since the CPU does not detect an ignition pulser signal within the predetermined time ts, the generation of the CPU pulse signal is ended in the predetermined time ts. [0091] Thereafter, the kick pedal is trodden down at time t2 to start kicking. If the CPU detects an ignition pulser signal, then the CPU discriminates that the engine has started its rotation, and starts generation of the CPU pulse signal. [0092] Consequently, the engine speed N gradually rises, and as the engine speed N rises, the battery voltage VB gradually becomes high as a result of generation of electric power by the AC generator. When the battery voltage VB reaches VB = v3 at time tl8, the CPU ends the generation of the CPU pulse signal. [0093] Based on the variations of the pump driving voltage of the fuel pump described above with reference to FIGS. 12(a) and 12 (b) , the starting operation method of the fuel pump is described below. FIG. 17 is a flowchart illustrating the starting operation method of the electromagnetic fuel pump according to the present invention. It is to be noted that STXX represents a step number. ST01 The main switch is switched on. [0094] ST02 It is discriminated whether or not the battery voltage VB is equal to or higher than the predetermined voltage v3 (that is, VB = v3) . If the battery voltage VB is not VB ^ v3 (NO, that is, VB If the battery voltage VB is VB ^ v3 (YES), then the processing advances to ST10. [0095] ST03 It is discriminated whether or not the 53 battery voltage VB is equal to or higher than the startup voltage v2 of the CPU but lower than the predetermined voltage v3 (that is, v2 If the battery voltage VB is not v2 If the battery voltage VB is v2 ^ VB ST04 The generated voltage by the AC generator is boosted. [0096] ST05 It is discriminated whether or not the battery voltage VB is equal to or higher than the startup voltage v2 of the CPU (VB > v2) . If the battery voltage VB is not VB > v2 (NO), then ST04 is executed again. If the battery voltage VB is VB > v2 (YES), then the processing advances to ST06. [0097] ST06 It is discriminated whether or not kicking is started, that is, whether or not kick starting is performed. If kicking is not started (NO), then ST06 is executed again. 54 If kicking is started (YES), then the processing advances to ST07. [0098] ST07 It is discriminated whether or not the CPU detects an ignition pulser signal. If an ignition pulser signal is not detected (NO), then the processing is ended. If an ignition pulser signal is detected (YES), then the processing advances to ST08. [0099] ST08 It is discriminated whether or not the engine speed N upon the kicking operation is lower than the preset engine speed Nst (that is, N If the engine speed N is not N If the engine speed N is N ST09 The kick starting continuous operation mode of the fuel pump is performed. ST10 The starter motor starting initial operation mode of the fuel pump is performed. [0100] ST11 It is discriminated whether or not the starter motor is started up, that is, whether or not 55 starter motor starting is performed. If the starter motor is not started up (NO), then ST11 is executed again. If the starter motor is started up (YES), then the processing advances to ST12. [0101] ET12 It is discriminated whethet ot not Che CPU detects an ignition pulser signal. If an ignition pulser signal is not detected (NO), then the processing is ended. If an ignition pulser signal is detected (YES), then the processing advances to ST13. ST13 The starter motor starting continuous operation mode of the fuel pump is carried out. ST14 The engine is started. The processing of the operation method of the fuel pump upon engine starting is ended thereby. [0102] FIG. 18 shows a first flowchart of the generated voltage boosting method according to the present invention, and the generated voltage boosting method is described with reference to the first flowchart together with a second flowchart shown in the next figure. It is to be noted that STXX represents a step number. ST21 The main switch is switched on. ST02 It is discriminated whether or not the battery voltage VB is VB If the battery voltage VB is not VB is, VB S v3), then the processing is ended. IF the battery voltage VB is VB ST23 It is discriminated whether or not the battery voltage VB is VB If the battery voltage VB is not VB If the battery voltage VB is VB ST24 The oscillator starts generation of the oscillation pulse signal. ST25 The CPU causes the generation of the oscillation pulse signal to be ended and starts generation of the CPU pulse signal (here, the timer is started up (turned on) (elapsed time t = 0)). ST26 It is discriminated whether or not the elapsed time t is t = predetermined time ts. If the time t is not t = ts (NO), then the 57 processing advances to ST27. If the time t is t = ts (YES), then the processing advances to ST28. [0105] ST27 It is discriminated whether or not kicking is started. If kicking is not started (NO), then the processing returns to ST26. If kicking is started (YES), then the processing advances to ST38 of FIG. 19 through a coupler C. ST28 The CPU ends the generation of the CPU pulse signal. ST29 Kicking is started. [0106] ST30 It is discriminated whether or not the battery voltage VB is 0 = battery voltage VB If the battery voltage VB is not 0 ^ VB If the battery voltage VB is 0 ST31 The oscillator starts generation of the oscillation pulse signal. 58 ST32 Kicking is started. Thereafter, the processing advances to ST36. ST33 Kicking is started. [0107] ST34 It is discriminated whether or not the battery voltage VB is VB ^ vl. If the battery voltage VB is not VB ^ vl (NO), then ST34 is executed again. If the battery voltage VB is VB ^ vl (YES), then the processing advances to ST35. ST35 The oscillator starts generation of the oscillation pulse signal [0108] ST36 ... It is discriminated whether or not the battery voltage VB is VB > startup voltage v2 of the CPU. If the battery voltage VB is not VB > v2 (NO), then ST36 is executed again. ST37 The CPU causes the generation of the oscillation pulse signal to be ended and starts generation of the CPU pulse signal (the timer is started up (turned on) (time t = 0)). Thereafter, the processing advances to ST38 of FIG. 19 through the coupler C. [0109] FIG. 19 is a second flowchart of the generated voltage boosting method according to the present invention. It is to be noted that STXX represents a step number. ST38 It is discriminated whether or not the time t is t = predetermined time ts. If the time t is not t = ts (NO), then the processing advances to ST39. If the time t is t = ts (YES), then the processing advances to ST41. [0110] ST39 It is discriminated whether or not the CPU detects an ignition pulser signal before the predetermined time ts. If an ignition pulse signal is not detected (NO), then the processing returns to ST38. If an ignition pulse signal is detected (YES), then the processing advances to ST40. [0111] ST40 The CPU also continues the generation of the CPU pulse signal after t = ts. ST41 The CPU ends the generation of the CPU pulse signal. ST42 It is discriminated whether or not the CPU detects an ignition pulser signal before the predetermined time ts. If an ignition pulser signal is not detected (NO), then ST4 2 is executed again. If an ignition pulse signal is detected (YES), then the processing advances to ST43. [0112] ST43 The CPU starts generation of the CPU pulse signal. ST44 It is discriminated whether or not the battery voltage VB is VB If the battery voltage VB is not VB If the battery voltage VB is VB ST45 It is discriminated whether or not the engine speed N is N ^ first predetermined speed NH (the first predetermined speed NH is equal to an engine speed nl illustrated in FIGS. 14 to 16). If the engine speed N is not N > NH (NO), then the processing advances to ST46. If the engine speed N is N > NH (YES) , then the processing advances to ST47. [0114] ST46 It is discriminated whether or not the engine speed N is N If the engine speed N is not N S NL (NO), then the processing advances to ST44. If the engine speed is N = NL (YES), then the processing advances to ST47 . ST47 The CPU ends the generation of the CPU pulse signal. [0115] FIGS. 20(a) to 20(c) are operation diagrams illustrating a control method for the engine provided with the electromagnetic fuel pump according to the present invention. FIG. 20(a) is a graph illustrating a state of the driving voltage to be supplied to the fuel pump, and the axis of ordinate represents the pump driving voltage DV (whose unit is V) of the fuel pump and the axis of abscissa represents the time t. For example, it is assumed that, while the engine is operating and a pulse-like voltage (whose voltage exhibits repetitions of the H level and the L level) is supplied to the fuel pump by the duty control, when the fuel pump is rendered inoperative (here, this is called "fuel pump failure") at time tlO and electric power to be supplied is not supplied any more (a portion indicated by a phantom line in the graph), the failure is detected at a point of time (t = til) at which the CPU does not detect the on state of the pump driving voltage by n times (that is, the CPU detects the L level by n times). It is to be noted that the failure signifies that something does not operate or function any more. [0116] FIG. 12(b) is a graph illustrating a countermeasure against a failure of the fuel pump when the engine speed is equal to or lower than a specified speed, and the axis of ordinate represents the engine speed N (whose unit is rpm) and the axis of abscissa represents the time t. Where the specified speed of the engine is represented by nst (for example, 3,000 rpm), if the CPU detects a failure of the fuel pump at time tl2 during operation of the engine at an engine speed equal to or lower than the specified speed nst, the CPU sends a control signal to the CDI apparatus to stop the ignition immediately to lower the speed of rotation of the engine and then stops the feeding to the fuel pump (to turn the FET 62 off in FIG. 11) at time tl3 at which a predetermined time Ta elapses after the time tl2 at which the ignition is stopped. [0117] FIG. 12(c) is a graph illustrating a countermeasure against a failure of the fuel pump when the engine speed exceeds a specified speed, and the axis of ordinate represents the engine speed N (whose unit is rpm) and the axis of abscissa represents the time t. Where engine speeds higher than the specified speed nst are represented by n2 and n3 and the maximum speed of the engine is represented by nmax, the range equal to or lower than the engine speed n2 is referred to as first rotation region, the range from the engine speed n2 to the engine speed n3 is referred to as second rotation region, and the range from the engine speed n3 to the engine speed nmax is referred to as third rotation region. [0118] For example, if the CPU detects a failure of the fuel pump at time tl5 during operation of the engine at an engine speed between n3 and nmax, then the CPU controls the ignition of the engine (referred to as ignition control ®. For example, the ignition timing is delayed or ignitions are thinned out) to lower the engine speed. Then, after the engine speed becomes equal to n3, this engine speed n3 is maintained. [0119] Further, the CPU controls the ignition of the engine (referred to as ignition control ©. Functions of the control are same as those of the ignition control ®) at time tl6 after the time Tb elapses after time tl5 to lower the engine speed. Then, when the engine speed becomes equal to n2, the engine speed n2 is maintained. Furthermore, the ignition of the engine is stopped at time tl7 after the time Tc elapses after time tl6, and the feeding to the fuel pump is stopped at time tl8 after the time Td elapses after time tl7. [0120] For example, if the CPU detects a failure of the fuel pump during operation of the engine at an engine speed between n2 and n3 as indicated by a broken line B, then the engine speed is lowered at the point of time at which the failure is detected. Then/ when the engine speed becomes equal to n2, the engine speed n2 is maintained. Then, the ignition of the engine is stopped after lapse of the time Tc after the detection of the failure, and the feeding to the fuel Pump is stopped after lapse of the time Td after the stopping of the ignition. [0121] If the CPU detects a failure of the fuel pump during operation of the engine at an engine speed between nst and n2, for example, as indicated by an alternate long and short dash line C, then the ignition of the engine is stopped after the time Tb and the time Tc elapse after the point of time at which the failure is detected. Then, the feeding to the fuel pump is stopped after lapse of the time Td from the stopping of the ignition. In this manner, the CPU 55a (refer to FIG. 8) serves also as an ignition control section which controls the ignition of the engine such that the ignition control ® or ® described hereinabove is performed and the ignition is stopped. The ignition control section is not limited to the CPU 55a but may include the control means 55. [0122] The motorcycle to which the present invention is applied to a scooter type vehicle and has a structure wherein a centrifugal clutch is used to transmit power from the engine to the driving wheel. The centrifugal clutch is connected or disconnected at an engine speed within a range substantially from 66 3,000 rpm to 4,000 rpm, and the specified speed nst given hereinabove is determined from the lower limit of the range while the engine speed n2 is determined taking a margin from the upper limit of the range into consideration. [0123] In particular, when the engine speed is equal to or higher than n2 (4,5 00 rpm), the centrifugal clutch is in a fully connected state and the motorcycle is in a running state. Therefore, for example, when the fuel pump is rendered inoperative in this state, if the main power supply is disconnected in order to stop the ignition of the engine or stop the feeding to the fuel pump, then it is estimated that the lighting system and so forth may not function any more, which may make an obstacle to the operation of the motorcycle. (Since the fuel pump is a part essentially required for operation of the engine, the feeding circuit to the fuel pump is normally provided in the main power supply circuit, and in order to stop the feeding to the fuel pump, the main power supply is stopped.) [0124] From the foregoing, where the engine speed is equal to or higher than n2, the engine speed is first lowered stepwise to the lower limit speed at which the centrifugal clutch is connected thereby to lower the speed of the motorcycle to inform the driver that an unexpected event has occurred. Then, in a state wherein the centrifugal clutch is not connected any more and the driving of the wheel disappears, the ignition of the engine is stopped to halt the feeding to the fuel pump. Consequently, stopping of the engine and stopping of the vehicle can be performed without making an obstacle to the running of the vehicle. [0125] As described with reference to FIGS. 7, 20(a), 20(b) , and 20 (c) , fifthly, according to the present invention, the control method for an electromagnetic fuel pump is characterized in that the control means 5 5 includes a CPU 55a serving as an ignition control section which controls, when a failure of the fuel pump 26 is detected, the speed of the engine 15 to a speed equal to or lower than a predetermined speed and then stops the ignition. [0126] For example, if the electromagnetic fuel pump 26 fails during running of the motorcycle 10, then since the failure of the fuel pump 26 is detected and the speed of the engine 15 is controlled to a speed equal to or lower than a predetermined speed, the variation of the output power of the engine 15 can be moderated, and the driver can recognize the failure of the electromagnetic fuel pump 2 6 readily. [0127] If the speed of the engine 15 is within the second rotation region or the third rotation region, the speed of the engine 15 is lowered stepwise so that the driver can detect that the fuel pump 26 has been rendered inoperative. [0128] Sixthly, according to the present invention, the control method for an electromagnetic fuel pump is characterized in that the CPU 55a as the ignition control section stops the ignition immediately when the speed of the engine is equal to or lower than the predetermined speed if a failure is detected. For example, when the engine speed is equal to or lower than the predetermined speed, if the electromagnetic fuel pump 26 fails, then the ignition is stopped immediately so that the driver can recognize readily that the electromagnetic fuel pump 26 has failed. [0129] When the speed of the engine 15 is within the first rotation region, by stopping the ignition, the engine 15 can be stopped smoothly, and further, the feeding to the fuel pump 26 can be stopped. [0130] FIG. 21 is a plan view (a view as viewed from above the engine below the luggage box) of the motorcycle provided with the electromagnetic fuel pump according to the present invention and shows that the carburetor 36 is disposed above the engine 15 and an end portion of a throttle cable 325 extending from the handle bar 11 (refer to FIG. 1) side is connected to the carburetor 36 while a seat catch frame 326 to which a seat catch (not shown) for holding the seat 147 {refer to FIG. 1) is attached to a rear portion of the rear frame 135b and the battery 18 and the radiator reserve tank 157 are disposed below the seat catch frame 326. Maintenance of the battery 18 and the radiator reserve tank 157 can be performed by removing a maintenance lid (not shown) removably provided on a rear wall of the luggage box 151 (refer to FIG. 1). Consequently, the maintenance facility of the battery 18 and the radiator reserve tank 157 is improved. It is to be noted that reference numeral 328 denotes a band for 70 securing the battery 18, 341 a plus terminal to which a fuse box 347 of the battery 18 is attached integrally, 342 a minus terminal, 343 a conductor connected to the minus terminal, and 345 a secondary air introducing tube connected to a lead valve 346 (refer to FIG. 4) attached to the head cover 311 for supplying air to the exhaust path of the engine 15 from the air cleaner 144 (refer to FIG. 1}. [0131] FIG. 2 2 is a perspective view of the engine of the motorcycle provided with the electromagnetic fuel pump according to the present invention and shows that the radiator 143 is attached to a side portion of the engine 15. It is to be noted that reference numeral 348 denotes a radiator cover which covers sidewardly of the radiator body and serves also as a wind introducing port, and 351 a radiator cap. [0132] FIG. 23 is a perspective view (a view as viewed from an obliquely rearwardly upward location to the vehicle) of the motorcycle provided with the electromagnetic fuel pump according to the present invention and shows that the engine control unit 16 is attached to a rear portion of the motorcycle 10 (refer to FIG. 1). It is to be noted that reference character 354, ... ("..." represents presence of a plurality of such elements) represents three bolts for attaching the engine control unit 16 to a rear frame portion 355 which forms a rear portion of the rear frame 135b (refer to FIG. 1), 356 a wire harness, 357 a regulator coupler connected to the power section 44 (refer to FIG. 8) in the engine control unit 16, and 358 a CPU coupler for connecting a CPU harness 3 61 branching from the wire harness 356 to the engine control unit 16. The regulator coupler 3 57 and the CPU coupler 3 58 are distributed to the left and the right of the vehicle body, respectively, and the degree of freedom in layout is raised and the increase in size of the couplers 3 57 and 358 is suppressed. [0133] FIG. 24 is a plan view of a rear portion of the motorcycle provided with the electromagnetic fuel pump according to the present invention, and shows a state wherein the engine control unit 16 (refer to FIG. 23) is removed from the rear portion of the motorcycle 10 (refer to FIG. 1) and shows a state wherein the reserve tank 157 is connected to the radiator 143 (refer to FIG. 22) by a hose 363 and the battery disconnection relay 42 is 72 disposed rearwardly of the battery 18. It is to be noted that reference numeral 366 denotes a stand unlock cable for canceling the locked state of the stand 146 (a state wherein the stand 146 is placed down and cannot be raised), 367 a seat unlock cable for canceling a state wherein the seat 147 (refer to FIG. 1) is locked in a closed state, 368 a relay cable connected to the battery disconnection relay 42, and 371 a battery cable connected to the terminals 341 and 342 (refer to FIG. 21) of the battery 18. [0134] [Effects of the Invention] The present invention exhibits the following effects from the configuration described above. With the control method for an electromagnetic fuel pump according to claim 1, the control section has a first operation mode set when a battery voltage with which the starter motor can operate is detected, and a second operation mode set when a battery voltage with which the starter motor cannot operate is detected and different from the first operation mode, and operation of the fuel pump upon starting is controlled in one of the first operation mode and the second operation mode. Therefore, in a case wherein the engine is started by the 73 kick starting apparatus and another case wherein the engine is started by the starter motor starting apparatus, preferable starting control of the electromagnetic fuel pump upon starting can be carried out with different control functions from each other, and the engine startability by the kick starting apparatus, for example, when fuel is not present in the carburetor can be improved. Moreover, upon starting of the engine by the starter motor starting apparatus, the electric power to be supplied to the fuel pump can be suppressed. [0135] With the control method for an electromagnetic fuel pump according to claim 2, the first operation mode and the second operation mode are duty control wherein on/off of the power supply to the fuel pump are repeated. Therefore, since the on/off ratio can be changed readily, the starting control method for the fuel pump can be set freely in accordance with the kick starting and the starter motor starting. [0136] With the control method for an electromagnetic fuel pump according to claim 3, the second operation mode has a period of the on/off control shorter than that of the first operation mode. Consequently, the on/off period of 74 the electromagnetic fuel pump becomes short, and the fuel supply amount to the carburetor can be increased. Accordingly, when there is no fuel in the carburetor, fuel can be filled into the carburetor rapidly, and the engine startability can be raised. [0137] With the control method for an electromagnetic fuel pump according to claim 4, the second operation mode has an on time longer than that of the first operation mode. Therefore, since the battery voltage is low upon starting of the engine by the kick starting apparatus when the battery is consumed, if the on time of the electromagnetic fuel pump is set to a time longer than that in a normal state so that the stroke of a plunger of the electromagnetic fuel pump can be increased, then the fuel supply amount to the carburetor can be increased. Accordingly, when there is no fuel in the carburetor, fuel can be supplied rapidly into the carburetor, and the engine startability can be raised. [0138] With the control method for an electromagnetic fuel pump according to claim 5, the control section includes an ignition control section which controls, when a failure of the fuel pump is detected, the speed of the 75 engine to a speed equal to or lower than a predetermined speed and then stops ignition. Therefore, for example, if the electromagnetic fuel Pump fails during running of the motorcycle, then since the failure of the fuel pump is detected and the speed of the engine is controlled to a speed equal to or lower than the predetermined speed, the variation of the output power of the engine can be moderated, and the driver can recognize the failure of the electromagnetic fuel pump readily. [0139] With the control method for an electromagnetic fuel pump according to claim 6, the ignition control section stops the ignition immediately when the speed of the engine when a failure is detected is equal to or lower than the predetermined speed. Therefore, for example, when the engine speed is equal to or lower than the predetermined speed, if the electromagnetic fuel pump fails, then the ignition is stopped immediately. Consequently, the driver can recognize readily that the electromagnetic fuel pump has failed. WE CLAIM: 1. A control method for an electromagnetic fuel pump including an electromagnetic fuel pump (26) for supplying fuel of a fuel tank (25) to an engine (15), a starter motor (23), starting apparatus for starting said engine with a starter motor which is fed from a battery (18), and a kick starting apparatus (23) for starting said engine (15) by a kicking operation and including a control section for controlling driving of said electromagnetic fuel pump (26), characterized in that said control section (55) has a first operation mode set when a battery voltage (VB) with which said starter motor (33) can operate is detected and a second operation mode set when a battery voltage (VB) with which said starter motor (33) cannot operate is detected and different from the first operation mode, and operation of said fuel pump (26) upon starting is controlled in one of the first operation mode and the second operation mode. 2. A control method for an electromagnetic fuel pump (26) as claimed in claim 1, wherein the first operation mode and the second operation mode are duty control wherein on/off of the power supply to said fuel pump are repeated. 3. A. control method for an electromagnetic fuel pump as claimed in claim 2, wherein the second operation mode has a period of the on/off control (tcs and tks) shorter than that of the first operation mode. 4. A control method for an electromagnetic fuel pump as claimed in claim 2, wherein the second operation mode has an on time (tc and tk) longer than that of the first operation mode. 5. A control method for an electromagnetic fuel pump as claimed in claim 1, wherein said control section (55) includes an ignition control section (55) includes an ignition control section (55a) which controls, when a failure of said fuel pump (26) is detected, the speed of said engine to a speed equal to or lower than a predetermined speed and then stops ignition. 6. A control method for an electromagnetic fuel pump as claimed in claim, 5, wherein said ignition control section (55a) stops the ignition immediately when the speed of said engine (N) when a failure is detected is equal to or lower than the predetermined speed (nst). 7. A control method for an electromagnetic fuel pump substantially as hereinbefore described with reference to the accompanying drawings. Dated this 7th day of December, 2001. 79

Documents:

1160-mum-2001-abstract.doc

1160-mum-2001-abstract.pdf

1160-mum-2001-certificate.pdf

1160-mum-2001-claims.doc

1160-mum-2001-claims.pdf

1160-mum-2001-correspondence(ipo).pdf

1160-mum-2001-correspondence.pdf

1160-mum-2001-description(granted).doc

1160-mum-2001-description(granted).pdf

1160-mum-2001-drawing.pdf

1160-mum-2001-european patent office.pdf

1160-mum-2001-form 1-07-12-2001.pdf

1160-mum-2001-form 1-24-12-2007.pdf

1160-mum-2001-form 13.pdf

1160-mum-2001-form 18.pdf

1160-mum-2001-form 2(granted).doc

1160-mum-2001-form 2(granted).pdf

1160-mum-2001-form 2(title page).pdf

1160-mum-2001-form 3.pdf

1160-mum-2001-form 5.pdf

1160-mum-2001-japanese government.pdf

1160-mum-2001-other.pdf

1160-mum-2001-petition under rule 137.pdf

1160-mum-2001-petition under rule 138.pdf

1160-mum-2001-power of authority.pdf

1160-mum-2001-us patent.pdf

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