Title of Invention

A STARTING CONTROL SYSTEM FOR AN ENGINE

Abstract

A starting control system for an engine comprising at least a fuel system (10, 17, 18, 20) for supplying fuel into a cylinder of said engine and an ignition system (16, 19, 30) for supplying ignition energy to an ignition plug, characterized by an exclusive control unit (21) which drive said ignition system (16, 19, 30) and said fuel pump (10) exclusively in a specific period of time after beginning an engine starting operation. wherein said fuel system (10, 17, 18, 20) includes an injector (20) for injecting fuel into the cylinder and a fuel pump (10) for supplying fuel into said injector (20).

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "A STARTING CONTROL SYSTEM FOR AN ENGINE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan, The following specification particularly describes the invention and the manner in which it is to be performed: ORIGINAL 618/MUM/2001 GRANTED 17-3-2006 [Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to a starting control system for an engine equipped with an injector, and particularly to a starting control system for an engine, which is capable of obtaining a good starting characteristic even in a state that the discharge capacity of a battery is reduced. [Prior Art] At the time of starting an engine, it is required to supply sufficient power, particularly, to an ignition coil. Accordingly, if it is intended to start an engine while carrying a current to a load, such as a headlamp, which consumes large amounts of power in a state that the discharge capacity of a battery is reduced, sufficient power cannot be supplied to an ignition coil, to cause a problem in reducing the starting characteristic of the engine. A starting control system for an engine intended to solve such a problem has been proposed in Japanese Patent Laid-open No. Hei 4-132877, Japanese Utility Model Registration No. 2518904, and Japanese Utility Model Laid-open No. Hei 2-18786, wherein a lamp load such as a headlamp is temporarily cut from a power supply line at the time of starting the engine. [Problem to be Solved by the Invention] In the above-described starting control system for an engine, since the lamp load such as a headlamp is cut from the power supply line at the time of starting the engine, power allowed to be supplied from a battery to an ignition coil can be increased. Accordingly, it is possible to improve the starting characteristic of the engine as compared with the conventional system. The above-described starting control system, however, has a problem. Namely, in the case where the system is applied to recent vehicles of a type in which an electric load is significantly increased, for example, by providing a fuel injection device in place of a carburetor, power allowed to be supplied from a battery to an ignition coil is insufficient yet. An object of the present invention is to solve the problem of the above - described prior art system, and to provide a starting control system for an engine, which is characterized by exclusively driving units not required to be necessarily simultaneously driven at the time of starting an engine, to save power to be supplied to each unit at the time of starting the engine, thereby improving the starting characteristic of the engine [Means for Solving the Problem] To solve the above object, according to the present invention, there is provided a starting control system for an engine including at least a fuel system for supplying fuel into a cylinder of the engine and an ignition system for supplying ignition energy to an ignition plug, characterized in that at least part of the fuel system is stopped at a timing when the ignition energy is supplied to the ignition plug in a specific period of time after beginning an engine starting operation. The fuel system and the ignition system are not required to be simultaneously driven, particularly, in a specific period of time after beginning an engine starting operation. For example, even by resting the ignition system in a period of time in which the fuel system is being operated and then operating the ignition system while resting the fuel system, fuel having been injected at the time of operating the fuel system can be exploded at the next ignition timing. By driving respective systems in a time-shared or exclusive control manner as described above, it is possible to reduce a power consumption at an arbitrary timing, and hence to supply sufficient power to the ignition system. The present invention relates to a starting control system for an engine comprising at least a fuel system for supplying fuel into a cylinder of said engine and an ignition system for supplying ignition energy to an ignition plug, characterized in that at least part of said fuel system and said ignition system are not simultaneously driven in a specific period of time after beginning an engine starting operation, wherein said fuel system includes an injector for injecting fuel into the cylinder and a fuel pump for supplying fuel into said injector, and said ignition system and said fuel pump are exclusively driven. [Brief Description of the Drawings] [FIG. 1] FIG. 1 is a block diagram of essential portions of a starting control system for an engine to which the present invention is applied. [FIG. 2] FIG. 2 is a flow chart showing an operation of a first embodiment of the present invention. [FIG. 3] FIG. 3 is a flow chart showing an operation of an exclusive control deciding process. [FIG. 4] FIG. 4 is a flow chart showing an operation of exclusive control. [FIG. 5] FIG. 5 is a timing chart showing an operation of a second embodiment of the present invention. [FIG. 6] FIG. 6 is a timing chart showing an operation of a third embodiment of the present invention. [0008] [Mode for Carrying Out the Invention] Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of essential portions of a starting control system for an engine to which the present invention is applied. Fuel stored in a fuel tank 11 is sucked by a fuel pump 10, and is supplied to an injector 20 by way of a fuel pipe 12. The fuel pump 10 is driven by a pump drive unit 17, and the injector 20 is driven by an injection drive unit 18. An output voltage from a battery 29 is supplied to an ignition unit 16 and a DC load via a main switch 28. The ignition unit 16 controls both a power supply to an ignition coil 19 and cutoff of the power supply thereto, to thereby supply ignition energy to an ignition plug 30. The ignition coil 19 includes a primary coil 19a to which a DC voltage is applied, and a secondary coil 19b which generates a high voltage corresponding to a change in current at the primary coil 19a. The ignition unit 16 causes the primary coil 19a to generate a rapid change in current in synchronization with an ignition timing. An AC voltage generated by a charge coil 25 of an AC generator 24 is supplied to a regulator 27. A pulser coil 23 outputs one pulser signal to the ignition unit 16 per one rotation,of the engine. A DC voltage outputted from the regulator 27 is supplied to the battery 29 and also supplied to the DC load via the main switch 28. An exclusive control unit 21 restricts the operations of the drive units 17 and 18 and the ignition unit 16 so that an ignition system including the ignition unit 16, the ignition coil 19, and the ignition plug 30 is driven not simultaneously but time -sharedly or exclusively with at least one of a pump system including the fuel pump 10 and an injection system including the injector 20. The wording "exclusive" used in this embodiment means that a state in which two units to be controlled are simultaneously driven is prohibited but a state in which two units to be controlled are not simultaneously driven. An operation of this embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a flow chart showing an operation of the above described exclusive control unit 21. The operation of the exclusive control unit 21 is typically executed for each cranking of the engine. In step S1, an exclusive control deciding process for deciding whether or not exclusive control is to be executed is carried out. FIG. 3 is a flow chart showing an operation of the exclusive control deciding process. Referring to FIG. 3, after turn-on of the main switch 28, in step Sll, a terminal voltage VBAT of the battery 29 is detected and is compared with a specific reference voltage Vref. In this embodiment, the reference voltage Vref is set to 8 V. Unless the battery voltage VBAT at the time of engine stall is less than 8V, it is decided that the discharge capacity of the battery is sufficient and whereby exclusive control is not required to be performed, and the process goes on to step S12. In step S12, "0" is set to an engine-stall counter Ces. The counter value of the engine-stall counter Ces represents the number of kicking a kick pedal, which has been repeatedly performed to start the engine but failed to start the engine. In step S13, a kick starting mode is reset. On the other hand, if it is decided in step Sll that the battery voltage VBAT is less than the reference voltage Vref, that is, if it is decided that the discharge capacity of the battery 29 is insufficient and whereby exclusive control is required to be performed, the process goes on to step S14. In step S14, it is decided whether or not a kick detecting flag Fkick (to be described later) is set. Since the flag Fkick is not set in the initial state, the process goes on to step S15. In step S15, it is decided whether or not an engine speed Ne is larger than 800 rpm. Here, if the starting of the engine is performed by kicking the kick pedal, the engine speed Ne instantly becomes a value more than 800 rpm, while if the starting of the engine is performed by a starter motor, the engine speed Ne is usually in a range of 400 to 500 rpm. Accordingly, if the engine speed Ne is equal to or less than 800 rpm, it is decided that the starting of the engine is performed by the starter motor. In this case, since the exclusive control is not required to be performed, the process goes on to step S12. On the contrary, if the engine speed Ne is more than 800 rpm, it is decided that the starting of the engine is performed by kicking the kick pedal. In this case, the process goes on to step S16. In step S16. The kick detecting flag Fkick is set. In step S17, it is decided whether or not a crankshaft has been rotated by 10 times or more after the crank position has been determined. Here, the crankshaft is rotated only 5 to 7 times by one kick starting operation. Accordingly, if the crankshaft has been rotated by 10 times or more, it is decided that the kick starting operation has been switched to the starter starting operation, and in this case, the process goes on to step S12. On the other hand, if the crankshaft has been rotated by less than 10 times, it is decided that the kick starting operation has been continued yet, and in this case, the process goes on to step S18. In step S18, the counter value of the engine-stall counter Ces is incremented by "1". In step S19, the kick starting mode is set. Referring again to FIG. 2, in step S2, the exclusive control is executed on the basis of the decided result of the above-described exclusive control deciding process. FIG. 4 is a flow chart showing an operation of the exclusive control. In step S21 shown in FIG. 4, the kick starting mode is referred. If it is decided that the kick starting mode is not set, the process goes on to step S22 in which the exclusive control unit 21 allows the pump drive unit 17 to drive the fuel pump 10. Accordingly, after this step, the fuel pump 10 is continuously driven, like the prior art control method. In step S23, the exclusive control unit 21 allows the injection drive unit 18 to drive the injector 20 and also allows the ignition unit 16 to perform an ignition operation. Accordingly, after this step, each of the injector 20 and the ignition unit 16 is driven with a specific timing, like the prior art control method. On the contrary, if it is decided in step S21 that the kick starting mode is set, the process goes on to step S24 in which a remainder given by dividing the counter value of the engine-stall counter Ces by "5" is taken as a variable N. In step S25, it is decided whether or not the variable N is "0". If the variable N is not "0", the process goes on to step S26 in which the exclusive control unit 21 allows the pump drive unit 17 to control the fuel pump 10. If the variable N is "0", the process goes on to step S27 in which the exclusive control unit 21 allows the injection drive unit 18 and the ignition unit 16 to be operated. As described above, according to this embodiment, at the time of starting the engine by kicking the kick pedal, if the repeated number of kicking is equal to or less than four, only the fuel pump 10 is driven, and when the repeated number of kicking reaches five, the injector 20 and the ignition unit 16 are both driven. Thereafter, the exclusive control will be repeated with the kicking operations repeated by five times taken as one cycle. In the above-described exclusive control, at the time of the fifth kicking operation, the fuel pump 10 is not driven; however, since the pressure is accumulated in the fuel pipe 12 or an accumulator (not shown) by the fuel pump 10 having been operated in response to the first to fourth kicking operations, the pressure in the fuel pump 12 is sufficiently raised. Accordingly, in step S27, even when the fuel pump 10 is left stopped, a sufficientamount of fuel can be injected in the cylinder to be exploded only by driving the injector 20 and the ignition unit 16. According to this embodiment, since the ignition system is driven exclusively with other electric loads, the electric load of the battery at the time of driving the ignition system can be reduced. As a result, it is possible to supply a sufficient amount of power to the ignition system, and hence to improve the starting characteristic of the engine. FIG. 5 is a tirning chart showing an operation of a second embodiment of the present invention, in which operational timings of the injector 20 of the injection system, the fuel pump 10 of the pump system, and the ignition coil 19 of the ignition system are shown with reference to a rotational position of a crankshaft. According to this embodiment, in a period tl in which power is supplied from the ignition unit 16 to the ignition coil 19, the current-carrying to the injector 20 and the fuel pump 10 is cut off to interrupt the operations thereof. As described above, according to this embodiment, at the timing when a current is carried to the ignition system, the current-carrying to both the fuel pump 10 and the injector 20 is cut off. Accordingly, it is possible to supply larger amounts of energy from the battery 29 to the ignition system, and hence to improve the starting characteristic of the engine. FIG. 6 is a timing chart showing operation of a third embodiment of the present invention, in which operational timings of the injector 20 of the injection system, the fuel pump 10 of the pump system, and the ignition coil 19 of the ignition system are shown with reference to a rotational position of a crankshaft. According to the above-described second embodiment, the "ON" period tl of the ignition coil 19 corresponds to the "OFF" period of the fuel pump 10, and therefore, both the drive periods thereof become exclusive. On the contrary, in this third embodiment, at the timing when the operational state of the ignition coil 19 is switched from the off-state into the on-state, the fuel pump 10 is kept in the on-state yet. The on-state of the fuel pump 10 is switched into the off-state immediately after the above switching timing of the ignition coil 19. Thereafter, the fuel pump 10 is kept in the off-state until the on state of the ignition coil 19 is switched into the off-state. In this way, according to this embodiment, the "ON" period of the ignition coil 19 does not correspond to the "OFF" period of the fuel pump 10; however, in a state immediately after the power supply to the ignition coil 19 begins, the current carried to the ignition coil 19 is gradually increased, that is, the ignition coil 19 does not require a large current, so that a sufficient amount of power can be given to the ignition coil 19 even in the on-state of the fuel pump 10. Since the fuel pump 10 is stopped at the "OFF" timing of the ignition coil 19 when the ignition coil 19 requires a large current, a large change in current can be given to the ignition coil 19. [Effect of the Invention] The present invention exhibits the following effects: (1) At the time of starting the engine by kicking the kick pedal, the fuel system and the ignition system are not simultaneously driven. Accordingly, since the electric load of the battery at the time of operating the ignition system is reduced, sufficient energy can be supplied to the ignition system, so that the starting characteristic of the engine is improved. (2) At the timing of current - carrying to the ignition system, since the current-carrying to the fuel pump is cut off, the electric load of the battery at the time of operating the ignition system is reduced. As a result, since the electric load at the time of operating the ignition system is reduced, sufficient energy can be supplied to the ignition system, so that the starting characteristic of the engine is improved. [Explanation of Reference Numerals] 10: fuel pump, 11: fuel tank, 12: fuel pipe, 16: ignition unit, 19: ignition coil, 20: injector, 21: exclusive control unit, 23: pulser coil, 24: AC generator, 25: charge coil, 27: regulator, 28: main switch, 29: battery WE CLAIM: 1. A starting control system for an engine comprising at least a fuel system (10, 17, 18, 20) for supplying fuel into a cylinder of said engine and an ignition system (16, 19, 30) for supplying ignition energy to an ignition plug, characterized by an exclusive control unit (21) which drive said ignition system (16, 19, 30) and said fuel pump (10) exclusively in a specific period of time after beginning an engine starting operation. wherein said fuel system (10, 17, 18, 20) includes an injector (20) for injecting fuel into the cylinder and a fuel pump (10) for supplying fuel into said injector (20). 2. A starting control system for an engine as claimed in claim 1, wherein said injector (20) and said fuel pump (10) are exclusively driven. 3. A starting control system for an engine including at least a fuel system (10, 17, 18, 20) for supplying fuel into a cylinder of said engine and an ignition system (16, 19, 30) for supplying ignition energy to an ignition plug (30), wherein at least part of said fuel system (10, 17, 18, 20) is stopped at a timing when the ignition energy is supplied to said ignition plug (30) in a specific period of time after beginning an engine starting operation, and wherein said fuel system (10, 17, 18, 20) comprises an injector (20) for injecting fuel into the cylinder and a fuel pump (10) for supplying fuel into said injector (20), and at least one of said injector and said fuel pump (10) is stopped at said timing when the ignition energy is supplied to said ignition plug (30), wherein said ignition system (16, 19, 30) comprises an ignition coil (19) including a primary coil (19a) and a secondary coil (19b) which are inductively coupled to each other, said secondary coil (19b) being connected to said ignition plug (30); and an ignition unit for beginning energization of said primary coil (19a) before an ignition timing and cutting off the energization in synchronization with said ignition timing; and wherein at least one of said injector (20) and said fuel pump (10) is stopped in a period of time from beginning of the energization of said primary coil to said ignition timing. 4. A starting control system for an engine as claimed in claim 3, wherein said ignition system (16, 19, 30) comprises an ignition coil (19) having a primary coil (19a) and a secondary coil (19b) which are inductively coupled to each other, said secondary coil (19b) being connected to said ignition plug; and an ignition unit for beginning energization of said primary coil (19a) before an ignition timing and cutting off the energization in synchronization with said ignition timing; and wherein at least one of said injector and said fuel pump (10) is stopped in a period of time from a specific timing after beginning the energization of said primary coil (19a) to said ignition timing. 5. A starting control system for an engine substantially as hereinbefore described and illustrated with reference to the foregoing examples. Dated this 3rd day of July, 2001. (SHUKADEV KHURAIJAM) OK REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS

Documents:

618-mum-2001-cancelled pages(17-03-2006).pdf

618-mum-2001-claims(17-03-2006).pdf

618-mum-2001-claims(granted)- (17-03-2006).doc

618-mum-2001-correspondence(06-10-2006).pdf

618-mum-2001-correspondence(ipo)-(13-03-2007).pdf

618-mum-2001-drawing(17-03-2006).pdf

618-mum-2001-form 1((03-07-2001).pdf

618-mum-2001-form 1(06-10-2006).pdf

618-mum-2001-form 18(14-06-2005).pdf

618-mum-2001-form 2(granted)- (17-03-2006).doc

618-mum-2001-form 2(granted)-(17-03-2006).pdf

618-mum-2001-form 3((03-07-2001).pdf

618-mum-2001-form 3(17-03-2006).pdf

618-mum-2001-form 4-(18-04-2006).pdf

618-mum-2001-form 4-(19-04-2006).pdf

618-mum-2001-form 5(03-07-2001).pdf

618-mum-2001-petition under role 137(17-03-2006).pdf

618-mum-2001-petition under role 138(17-03-2006).pdf

618-mum-2001-power of authority(17-03-2006).pdf

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