Title of Invention

FUEL INJECTION DEVICE MODULE

Abstract

In a fuel injection device module in which, to an electrically-operated motor (10), a fuel pump (11) which is driven by an output shaft (21a) of the motor (10) so as to supply fuel to an injector (13) under pressure and an injection pressure regulator (14) which regulates pressure of a fuel discharged from the fuel pump (11) are integrally connected, an injector holder (47) which holds the injector (13) is integrally formed with a module body (40) which is connected to the fuel pump (11), and a fuel passage (46) which allows the fuel pump (11) , the injection pressure regulator (14) and the injector (13) to communicate with each other is forated in the module body (40) . Thus, it is possible to achieve the large reduction of cost of a fuel injection device module by realizing the elimination of a high-pressure fuel conduit between an injector and a fuel pump.

Full Text

FUEL INJECTION DEVICE MODULE FIELD OF THE INVENTION The present invention relates to a fuel injection device module which is served for a vehicle such as a two-wheeled motor vehicle and, more particularly to an improvement of a fuel injection device module in which, to an electrically-operated motor, a fuel pump which is driven by an output shaft of the motor, boosts a pressure of fuel introduced from a fuel tank and supplies the fuel to an injector under pressure, and an injection pressure regulator which regulates pressure of the fuel supplied to the injector under pressure from the fuel pump are integrally connected. BACKGROUND ART Such a fuel injection device module has been known as disclosed in Patent Document 1, for example. [Patent Document 1] Japanese Patent Application Laid-open No. 2000-297711. In a vehicle provided with such a conventional fuel injection device module, since the module is arranged in the midst of the engine and the fuel tank, it is necessary to install an expensive high-pressure fuel conduit between the in j ector mounted on the engine and the fuel pump of the fuel injection device module and this hampers the reduction of cost of the above-mentioned fuel injection device module. In addition, such a structure that the piping between an injector and a fuel pump is simplified has been proposed in the following Patent Document 2. [Patent Document 2] Japanese Patent Application Laid-open No. 3-117680 However, in Document 2, the injector and the fuel pump are formed integrally with an intake pipe connected to an engine, and when the injector and fuel pump are subjected to maintenance, it is necessary to disassemble the intake pipe into two pipe portions; that is, a modular arrangement is not employed. DISCLOSURE OF THE INVENTION The present invention has been made in view of such circumstances and it is an object of the present invention to enable a high pressure fuel conduit between an injector and a fuel pump to be eliminated and enable them to be arranged in a compact manner in a confined space of a two-wheeled motor vehicle, etc. while ensuring that maintenance is simple, thereby reducing the cost of the fuel injection device module. To achieve the above-mentioned object, according to a first feature of the present invention, there is provided a fuel injection device module, in which, to an electrically-operated motor, a fuel pump which is driven by an output shaft of the motor, boosts a pressure of fuel introduced from a fuel tank and supplies the fuel to an injector under pressure, and an injection pressure regulator which regulates pressure of the fuel supplied to the injector under pressure from the fuel pump are integrally connected, characterized in that an injector holder which holds the injector is integrally formed with a module body which is connected to the fuel pump, and a fuel passage which allows the fuel pump, the injection pressure regulator and the injector to communicate each other is formed in the module body, a fuel strainer filtering fuel introduced from the fuel tank is integrally joined to the fuel pump, the fuel pump and the injection pressure regulator are disposed on a base portion of the injector so as to be adjacent to each other in a direction intersecting the axial direction of the injector, and the fuel strainer and the injection pressure regulator are arranged in a divided manner so that, relative to the pump axis of the fuel pump, one thereof is at one end side in the axial direction and the other thereof is at the other end side in the axial direction. With the first feature, the module body also functions as a high pressure fuel conduit which connects between the conventional fuel pump and injector and hence, it is possible to eliminate or omit the expensive high pressure fuel conduit and the piping operation whereby the reduction of cost of the fuel injection device module can be achieved, and maintenance of the fuel pump, the injector, the injection pressure regulator, etc. becomes easy. Furthermore, since the fuel strainer is a component of the fuel injection device module, piping between the fuel strainer and the fuel pump can be eliminated, and since the fuel strainer filters fuel that is present upstream of the fuel pump, it is possible to use an inexpensive low-pressure type, thereby contributing to a reduction in the cost of the fuel injection device module. In addition, since the fuel pump and the injection pressure regulator are disposed on the base portion of the injector so as to be adjacent to each other in the direction intersecting the axial direction of the injector, and the fuel strainer and the injection pressure regulator are arranged in a divided manner so that, relative to the pump axis of the fuel pump, one thereof is at one end side in the axial direction and the other thereof is at the other end side in the axial direction, it is possible to efficiently utilize the space that extends in a direction intersecting the axis of the injector, thus enabling the fuel pump, the injection pressure regulator, and the fuel strainer to be arranged compactly and thereby enabling protrusion in the axial direction of the injector to be minimized. Further, according to a second feature of the present invention, in addition to the first feature, a sideway-turn shut-off valve which shuts off the fuel passage between the fuel pump and the injector in response to sideway turning of a vehicle is provided to the module body. With this second feature, not only the driving of the engine is automatically rapidly stopped when the vehicle turns sideways, but also it is possible to prevent the flow-out of the fuel to the outside by the sideway-turn shut-off valve even when the injector is removed from the engine or the injector holder is removed from the injector. Moreover, according to a third feature of the present invention, in addition to the first feature, there is provided the fuel injection device module wherein the fuel injection device module and an intake pipe of the engine are arranged so as to be adjacent to each other, and the injector is held so as to be sandwiched between the module body and the Intake pipe. With this third feature, it is possible to utilize the intake pipe for mounting of the fuel injection device module, and the mounting structure can be simplified. Furthermore, according to a fourth feature of the present invention, in addition to the second feature, there is provided the fuel injection device module wherein the sideway-turn shut-off valve is formed from a cylindrical valve chamber and a spherical valve element that rolls within the valve chamber. With this fourth feature, when a two-wheeled motor vehicle, etc. equipped with the fuel injection device module rolls over, the sideway-turn shut-off valve can prevent fuel from flowing to the outside. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view of an essential part of a motorcycle provided with a fuel injection device module of the present invention. Fig. 2 is an enlarged side view of the above-mentioned fuel injection device module. Fig. 3 is an enlarged plan view of the fuel injection device module. Fig. 4 is a cross-sectional view taken along a line 4-4 in Fig. 2. Fig. 5 is a cross-sectional view taken along a line 5-5 in Fig. 2. Fig. 6 is a cross-sectional view taken along a line 6-6 in Fig. 2. Fig. 7 is a cross-sectional view taken along a line 7 - 7 in Fig. 6. Fig. 8A to 8C are explanatory views of the constitution and the manner of operation of a sideway-turn shut-off valve. BEST MODE FOR CARRYING OUT THE INVENTION Modes for carrying out the present invention are explained hereinafter based on preferred embodiments of the present invention shown in attached drawings. In Fig. 1, a body frame 1 of a two-wheeled motor vehicle M as one example of a vehicle is formed of a front pipe If which extends rearward and downward from a head pipe not shown in the drawing and a rear pipe lr which erects from a rear end of the front pipe If and extends rearward, wherein a 4-cycle engine E which is arranged below the front pipe If is suspended from the front pipe If and the fuel tank T is mounted on the rear pipe lr. In the above-mentioned engine E, a cylinder block 3 is arranged substantially horizontally with a cylinder head 2 directed toward a front side of the two-wheeled motor vehicle M. To an upper end surface of the cylinder head 2 in which an intake port 4 is opened, an intake pipe 5 which is communicated with the intake port 4 is joined. A throttle body 6 which is provided with a throttle valve is connected to this intake pipe 5, while an air cleaner 7 is connected to the throttle body 6. A support flange 5a is mounted on an upper wall of the intake pipe 5 and a fuel injection device module MF of the present invention which boosts pressure of fuel of the above-mentioned fuel tank T and injects the fuel into the intake port 4 is mounted on the support flange 5a. This fuel injection device module MF is explained in conjunction with Fig. 2 to Fig. 7. The fuel injection device module MF includes an electrically-operated motor 10, a fuel pump 11, a fuel strainer 12, an injector 13, an injection pressure regulator 14, a residual pressure holding valve 15 and a sideway-turn shut-off valve 16. As shown in Fig. 4 and Fig. 5, the electrically-operated motor 10 is of a brushless type and the inside of a motor housing 17 thereof is hermetically partitioned into an outer-periphery-side stator chamber 18 and an inner-periphery-side rotor chamber 19 by a cylindrical partition wall 17a which is integrally formed with the motor housing 17. A stator coil 20 is housed in the stator chamber 18 and a rotor 21 which fixedly mounts a permanent magnet 22 on an outer periphery thereof is housed in the rotor chamber 19. A bearing boss 23 which is arranged at a hollow portion of the rotor 21 is integrally formed on the cylindrical partition wall 17a and an output shaft 21a of the rotor 21 is rotatably supported by way of a bearing member 24. A pump housing 26 of the fuel pump 11 is connected to one end surface of the motor housing 17. The pump housing 26 is formed of an inner housing 26a and an outer housing 26b which is fitted on an outer periphery of the inner housing 26a by way of a sealing member 27 and defines a pump chamber 28 between the inner housing 26a and the outer housing 26b. The outer housing 26b is fixedly mounted on the motor housing 17 using a plurality of bolts 29 such that the inner housing 26a is sandwiched by the outer housing 26b and the motor housing 17. The output shaft 21a of the electrically-operated motor 10 has a distal end portion thereof extended into the above-mentioned pump chamber 28 and a pump rotor 30 is connected to the distal end portion in the pump chamber 28. The fuel pump 11 having such a constitution is of a Westco type. On an outer side surface of the outer housing 26b, an intake pipe 31 which induces the fuel into the pump chamber 28, a discharge pipe 32 which discharges the fuel from the pump chamber 28 and a vapor discharge pipe 33 which discharges the vapor from the pump chamber 28 are integrally mounted in a projecting manner. That is, the vapor discharge pipe 33 is communicated with the pump chamber 28 through a small hole 34 at a position where the vapor can be easily discharged from the pump chamber 28. A strainer base 35 is integrally formed on the intake pipe 31. The above-mentioned fuel strainer 12 is formed of the strainer base 35, a strainer casing 36 which is connected to the strainer base 35 and a strainer element 37 which is housed in the inside of the strainer casing 36. To a fuel introduction connection pipe 38 which is integrally formed on the strainer casing 36, a fuel supply pipe 39 which is extended from the fuel tank T is connected, wherein the fuel in the inside of the fuel tank T flows downward to the fuel strainer 12 by gravity. As shown in Fig. 7, a module body 40 which is connected to the above-mentioned discharge pipe 32 and the vapor discharge pipe 33 is fixedly mounted on brackets 41 which are projected from one side surface of the motor housing 17 using bolts 42. The above-mentioned injector 13, the injection pressure regulator 14, the residual pressure holding valve 15 and the sideway-turn shut-off valve 16 are mounted on the module body 40. The residual pressure holding valve 15 is formed of a known check valve. An inlet hole 44 of the sideway-turn shut-off valve 16 formed in the module body 40 is communicated with the above-mentioned discharge pipe 32. Further, an outlet hole 45 of the sideway-turn shut-off valve 16 is also communicated with an injection fuel passage 46 formed in the module body 40. The injector 13 and the injection pressure regulator 14 are connected to the injection fuel passage 46 in parallel, while the residual pressure holding valve 15 which prevents a backflow of the fuel toward the discharge pipe 32 side is interposed in the injection fuel passage 46 upstreamof the injector 13 and the injection pressure regulator 14. On one side of the module body 40, an injector holder 47 which holds the injector 13 is integrally formed. The injector holder 47 includes a mounting flange 47a which corresponds to a support flange 5a of the above-mentioned intake pipe 5. By connecting the mounting flange 47a to the support flange 5a using bolts 49, a fuel injection portion of the injector 13 is inserted into an injector mounting hole 50 which is opened in the support flange 5a and is directed toward the intake port 4. As shown in Fig. 4, the injection pressure regulator 14 is formed of a regulator housing 61 which has a valve sheet 62 which faces the injection fuel passage 46 and is integrally formed with the module body 40, a valve element 63 which is housed in the regulator housing 61 and faces the valve sheet 62 in an opposed manner, a pressure regulating spring 64 which biases the valve element 63 in the direction that the valve element 63 rests on the valve sheet 62, and an adjustment screw 65 which adjusts a set load of the pressure regulating spring 64 by being screwed into the regulator housing 61. The inside of the regulator housing 61 is communicated with a fuel return connecting pipe 67 which is integrally formed with the module body 40 by way of a fuel return passage 66 formed in the module body 40. When the discharge pressure of the fuel pump 11, that is, the pressure of the injection fuel passage 46 becomes equal to or more than a predetermined value, the valve element 63 is separated from the valve sheet 62 and hence, the extra fuel is discharged to the regulator housing 61 whereby the pressure of the fuel injection passage 46 is held at the predetermined value. The extra fuel discharged to the regulator housing 61 advances to the fuel return passage 66. The above-mentioned vapor discharge pipe 33 is opened in partway along the fuel return passage 66. Further, a fuel return pipe 68 which reaches the fuel tank T is connected to the fuel return connecting pipe 67. Returning back to Fig. 1, an electronic control unit 70 is arranged at one side of the above-mentioned throttle body 6. The electronic control unit 70 controls operations of the injector 13, the electrically-operated motor 10 and an ignition coil (not shown in the drawing) and the like in response to inputted signals such as an engine rotational speed Ne, an engine temperature (a temperature of a lubricant, for example) Te, the degree of throttle opening Th of the throttle body 6, a crank position Cp and the like. Here, during the operation of the engine E, the fuel in the inside of the fuel tank T flows down through the fuel supply pipe 39 and reaches the fuel introduction connection pipe 38 of the fuel injection device module MP and, thereafter, the fuel flows into the strainer casing 36 of the fuel strainer 12 and is filtered by the strainer element 37. The fuel which is filtered in this manner is taken into the pump chamber 28 of the fuel pump 11 and has the pressure thereof boosted by the rotation of the pump rotor 30 and is supplied to the injection fuel passage 46 from the discharge pipe 32 under pressure. During such an operation, vapor which is generated in the pump chamber 28 of the fuel pump 11 is discharged to the vapor discharge pipe 33 and reaches the fuel return passage 66. The high-pressure fuel which is supplied under pressure to the injection fuel passage 46 is supplied to the injector 13 through the sideway-turn shut-off valve 16 and the residual pressure holding valve 15 and, thereafter, is injected to the intake port 4 from the injector 13. During such an operation, as mentioned previously, the extra fuel which passes the injection pressure regulator 14 from the injection fuel passage 46 passes the fuel return passage 66 at a relatively high speed. In the midst of such an operation, the vapor from the vapor discharge pipe 33 is taken into the fuel return passage 66 by an ejector effect and hence, the discharge of the vapor is accelerated. When the vapor is discharged from the fuel pump 11, it is possible to supply fuel in a favorable state which contains no vapor to the injector 13. The vapor which is discharged to the fuel return passage 66 from the vapor discharge pipe 33 is made to return to the fuel tank T through the fuel return pipe 68 together with the extra fuel and they are subjected to the gas-liquid separation in the fuel tank T. When the operation of the electrically-operated motor 10 is stopped along with stopping of the operation of the engine E, although the fuel pump 11 stops discharging of the fuel, the residual pressure holding valve 15 of the injection fuel passage 46 is automatically shut off so that a backflow of the fuel in the fuel passage 46 from the injector 13 side to the fuel pump 11 side can be blocked, whereby it is possible to maintain the fuel of a given pressure at the inlet side of the injector 13. Accordingly, even at the time of restarting the engine E, the injector 13 can readily perform the injection of the fuel thus enhancing the starting ability. Subsequently, the above-mentioned sideway-turn shut-off valve 16 is explained in conjunction with Fig. 8, The sideway-turn shut-off valve 16 includes, as shown in Fig. 8B, a first valve chamber 55 having a cylindrical shape which is formed on the module body 40 such that the first valve chamber 55 assumes a leftward and upward oblique posture in an erected state of the two-wheeled motor vehicle M, and a second valve chamber 56 having a cylindrical shape which is formed on the module body 40 such that the second valve chamber 56 assumes a rightward and upward oblique posture opposite to the above-mentioned posture. An upper end of the first valve chamber 55 is connected to an intermediate portion of the second valve chamber 56. A first valve seat 55a and a second valve seat 56a are formed on respective upper portions of the first and second valve chambers 55, 56. The inlet hole 44 which is communicated with discharge tube 32 of the above-mentioned fuel pump 11 opens in a lower portion of the first valve seat 55a, while the above-mentioned outlet hole 45 opens in an upper portion of the second valve seat 56a. In the first and second valve chambers 55, 56, spherical valve elements 57, 58 which can be respectively rested on the first and second valve seats 55a, 56a are housed. Respective lower ends of the first and second valve chambers 55, 56 are clogged by screw plugs 59, 60. Here, in the erected state of the two-wheeled motor vehicle M, as shown in Fig. 8B, the first and second valve elements 57, 58 are retained on the plugs 59, 60 separate from the first and second valve seats 55a, 56a due to the deadweight thereof. Accordingly, the inlet hole 44 and the outlet hole 45 are communicated with each other thus allowing the supply of fuel from the fuel pump 11 to the injector 13. On the other hand, when the two-wheeled motor vehicle M turns either in the left sideway or in the right sideway by a chance, as shown in Fig. 8A or Fig. 8C, along with the turning sideways in the substantially horizontal direction of the first valve chamber 55 or the second valve chamber 56, the first valve element 57 or the second valve element 58 rests on the first valve seat 55a or the second valve seat 56a due to inertia thereof whereby the passage between the inlet hole 44 and the outlet hole 45 is shut off in both cases. When the first valve element 57 or the second valve element 58 once rests on the first valve seat 55a or the second valve seat 56a, this seated state is held by the fuel pressure at the inlet hole 44 side. Accordingly, even when the injector 13 is removed from the engine E or the injector holder 47 is removed from the injector 13 due to the turning sideways of the two-wheeled motor vehicle Mf it is possible to prevent the flow-out of the fuel from the fuel injection passage 46 using the sideway-turn shut-off valve 16. Here, the fuel injection device module MF is formed such that the module body 40 is integrally connected to the outer housing 26b of the fuel pump 11 which is integrally connected with the electrically-operated motor 10, the residual pressure holding valve 15, the injection pressure regulator 14 and the sideway-turn shut-off valve 16 are mounted on the module body 40, the injector holder 47 which holds the injector 13 is integrally formed with the module body 40, and the injection fuel passage 46 which allows the injector 13, the residual pressure holding valve 15, the injection pressure regulator 14 and the sideway-turn shut-off valve 16 to communicate with each other is formed in the module body 40. Accordingly, the module body 40 also functions as a high pressure fuel conduit which connects between the conventional fuel pump 11 and the injector 13 particularly and hence, the expensive high pressure fuel conduit and the piping operation thereof can be eliminated or omitted whereby the large reduction of the cost of the fuel injection device module MF can be achieved. Further, since the sideway-turn shut-off valve 16 is incorporated into the module body 40, when the two-wheeled motor vehicle M turns sideways, the operation of the engine E can be rapidly stopped automatically. Further, even when the injector 13 is removed from the engine E or the injector holder 47 is removed from the injector 13, it is possible to prevent the flow-out of the fuel to the outside from the sideway-turn shut-off valve 16. Further, since the fuel strainer 12 which allows the introduction of the fuel from the fuel tank T and filters the fuel is integrally connected to the fuel pump 11, the fuel strainer 12 forms a constitutional element of the fuel injection device module MF and hence, the piping between the fuel strainer 12 and the fuel pump 11 can be eliminated. Further, since the fuel strainer 12 filters the fuel upstream of the fuel pump 11, the inexpensive low-pressure type fuel strainer is sufficient thus contributing to the reduction of cost of the fuel injection device module MF, The present invention is not limited to the above-mentioned embodiments and various design variations are considered without departing from the gist of the present invention. We claim, 1. A fuel injection device module in which, to an electrically operated motor (10), a fuel pump (11) which is driven by an output shaft (21a) of the motor (10), boosts a pressure of fuel introduced from a fuel tank (T) and supplies the fuel to an injector (13) under pressure, and an injection pressure regulator (14) which regulates pressure of the fuel supplied to the injector (13) under pressure from the fuel pump (11) are integrally connected, characterized in that an injector holder (47) which holds the injector (13) is integrally formed with a module body (40) which is connected to the fuel pump (11), and a fuel passage (46) which allows the fuel pump (11), the injection pressure regulator (14) and the injector (13) to communicate with each other is formed in the module body (40) , a fuel strainer (12) filtering fuel introduced from the fuel tank (T) is integrally joined to the fuel pump (11), the fuel pump (11) and the injection pressure regulator (14) are disposed on a base portion of the injector (13) so as to be adjacent to each other in a direction intersecting the axial direction of the injector (13), and the fuel strainer (12) and the injection pressure regulator (14) are arranged in a divided manner so that, relative to the pump axis of the fuel pump (11), one thereof is at one end side in the axial direction and the other thereof is at the other end side in the axial direction . 2. A fuel injection device module as claimed in claim 1, wherein a sideway-turn shyt-off valve (16) which shuts off the fuel passage (46) between the fuel pump (11) and the injector (13) in response to sideway turning of a vehicle is provided to the module body (40). 3. A fuel injection device module as claimed in claim 1 wherein the fuel injection device module (MF) and an intake pipe (5) of the engine (E) are arranged so as to be adjacent to each other, and the injector (13) is held so as to be sandwiched between the module body (40) and the intake pipe (5). 4. A fuel injection device module as claimed in claim 2, Wherein the sideway-turn shut-off valve (16) is formed from a cylindrical valve chamber (55, 56) and a spherical valve element (57, 58) that rolls within the valve chamber. Dated this 20 day of April 2005

Documents:

672-chenp-2005-abstract.pdf

672-chenp-2005-claims.pdf

672-chenp-2005-correspondnece-others.pdf

672-chenp-2005-correspondnece-po.pdf

672-chenp-2005-description(complete).pdf

672-chenp-2005-drawings.pdf

672-chenp-2005-form 1.pdf

672-chenp-2005-form 18.pdf

672-chenp-2005-form 26.pdf

672-chenp-2005-form 3.pdf

672-chenp-2005-form 5.pdf

672-chenp-2005-pct.pdf