JP2012225291A - Fuel feed device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive fuel feed device for an engine having a fuel path of simple structure.SOLUTION: This fuel feed device for an engine includes: a device case 8 which is formed integrally with a throttle body 1 and stores a fuel pump 6 from the same direction as a direction in which a fuel injection valve 5 is installed on the throttle body 1; and a holding member 9 which holds the fuel pump 6 on the device case 8 and holds the fuel injection valve 5 on the throttle body 1. A fuel path 43 connecting the delivery pipe 19 of the fuel pump 6 to the fuel injection valve 5 is provided to the holding member 9.

Description

  The present invention relates to a throttle body having an intake passage connected to an intake port of an engine, a throttle valve that is pivotally supported by the throttle body to open and close the intake passage, and fuel that is attached to the throttle body and injects fuel into the intake passage. The present invention relates to an improvement in a fuel supply device for an engine, which includes a fuel injection valve that operates and an electric fuel pump that is attached to the throttle body to supply fuel to the fuel injection valve.

  Such a fuel supply device for an engine is already known as disclosed in Patent Document 1 below.

JP 2005-105987 A

  In a conventional fuel supply system for an engine, a fuel pump is housed and held in a pump case formed integrally with a throttle body, and a fuel passage for supplying fuel from the fuel pump to a fuel injection valve is provided as a pump case. Since the fuel passage forming member is connected to the member, the structure of the fuel passage is complicated, the number of parts and the number of assembling steps are increased, and it is difficult to reduce the cost.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fuel supply device for an engine having a simple and inexpensive fuel passage structure.

  In order to achieve the above object, the present invention provides a throttle body having an intake passage connected to an intake port of an engine, a throttle valve that is pivotally supported by the throttle body and opens and closes the intake passage, and is attached to the throttle body. In the fuel supply device for an engine, the throttle body includes: a fuel injection valve that injects fuel into the intake passage; and an electric fuel pump that is attached to the throttle body to supply fuel to the fuel injection valve. A device case for housing the fuel pump from the same direction as the mounting direction of the fuel injection valve to the throttle body, holding the fuel pump in the device case, and the fuel injection valve And a holding member for holding the throttle body to the throttle body. In that a fuel passage communicating pipe to the fuel inlet tube portion of the fuel injection valve to the first feature.

  According to the present invention, in addition to the first feature, the device case has an opening on one side, and the fuel pump is disposed through the opening in the device case. A second feature is that the fuel injection valve mounted on the throttle body is provided.

  Furthermore, in addition to the first or second feature, the present invention includes a first support portion that fits the holding member through a seal member to support the fuel discharge pipe, and the fuel inlet tube portion. A second support part fitted to the support member via a seal member and a connecting cylinder part integrally connecting the first and second support parts to each other, and the hollow part of the connecting cylinder part is A third feature is that the fuel passage communicates between the fuel discharge pipe and the fuel injection valve.

  In addition to any one of the first to second features, the present invention provides a bus bar for supplying power to the fuel pump by insert molding the holding member so that the bus bar extends over the connecting cylinder portion and the first support portion. The fourth feature is that it is buried.

  Furthermore, the present invention is characterized in that, in addition to any of the second features, a case lid for closing the opening is joined to the device case.

  Furthermore, in addition to the first or second feature of the present invention, the device case is provided with a fuel chamber adjacent to the fuel pump, the fuel chamber communicating with the inside of the fuel tank and discharging the vapor from the fuel pump. According to a sixth aspect of the present invention, the device case is equipped with a regulator that discharges surplus fuel from the fuel passage to the fuel chamber and adjusts a discharge pressure of the fuel pump. The fuel chamber corresponds to a second fuel chamber 10d in an embodiment of the present invention described later.

  In addition to the sixth feature of the present invention, the regulator is disposed between the fuel pump and the fuel injection valve, branches to the holding member from an intermediate portion of the fuel passage, and reaches the inlet of the regulator. The seventh feature is that a fuel branch path is formed.

  Furthermore, in addition to the fifth feature, the present invention has an eighth feature in which the holding member is held by the case lid.

  Furthermore, in addition to the fifth or eighth feature, the present invention has a core pin insertion port for forming the fuel passage, and the holding member closes the core pin insertion port. The ninth feature is that the cap is prevented from coming off by the inner wall of at least one of the device case and the case lid.

  According to the first feature of the present invention, the fuel injection valve can be assembled to the throttle body and the fuel pump can be assembled to the device case from the same direction, so that the assemblability is good. In addition, the holding member that holds the fuel pump in the device case and holds the fuel injection valve in the throttle body also serves as a fuel conduit that communicates between the discharge pipe of the fuel pump and the fuel inlet cylinder of the fuel injection valve. Therefore, no special piping for the fuel passage is necessary, and therefore the structure of the fuel supply device to the engine can be effectively simplified, which can contribute to the cost reduction.

  According to the second aspect of the present invention, since not only the fuel pump but also the fuel injection valve can be protected from contact with other objects by a single device case, the structure of the fuel supply device to the engine can be simplified. And it can contribute to the improvement of durability.

  According to the third aspect of the present invention, the first support portion of the device case is fitted to the fuel discharge pipe of the fuel pump via the seal member, and the second support portion of the device case is connected to the fuel of the fuel injection valve. By fitting the inlet cylinder through the seal member, the fuel pump and the fuel injection valve can be supported, and at the same time, the fuel passage can be arranged between the fuel discharge pipe and the fuel inlet cylinder. Becomes better. Moreover, even if there is a backlash in the axial direction at each fitting portion, fuel leakage from each fitting portion can be prevented by the presence of the seal member. As a result, a large dimensional error in the axial direction is allowed in each fitting portion, which facilitates manufacture and assembly, and can contribute to cost reduction.

  According to the fourth feature of the present invention, the embedment of the bus bar in the holding member simplifies the electrical wiring to the electric fuel pump and can enhance the rigidity of the holding member. The fuel pump and the fuel injection valve can be firmly held by the holding member. In other words, toughness against fuel leakage from the fuel pump and the fuel injection valve can be ensured with a simple structure.

  According to the fifth aspect of the present invention, the cooperation of the device case and the case lid can reliably protect the fuel pump and the fuel injection valve from contact with other objects, and can also protect against rainwater, dust, and the like. it can.

  According to the sixth aspect of the present invention, since the regulator is mounted on the holding member that holds the fuel pump and the fuel injection valve, a dedicated support member that supports the regulator becomes unnecessary and the regulator is discharged from the regulator. Since the surplus fuel is discharged from the fuel pump to the fuel chamber where the vapor is discharged, a dedicated passage for discharging surplus fuel from the regulator is unnecessary.

  According to the seventh feature of the present invention, since the regulator is disposed on the holding member by using a dead space between the fuel pump and the fuel injection valve, it is possible to prevent the holding member from being enlarged due to the mounting of the regulator. In addition, the fuel branch path that branches from the middle of the fuel passage between the fuel pump and the fuel injection valve and reaches the regulator inlet can be made extremely short, which also contributes to preventing the holding member from becoming large. To do.

  According to the eighth feature of the present invention, the holding structure of the holding member can be simplified.

  According to the ninth aspect of the present invention, it is possible to easily and reliably prevent the cap from being pulled out by using the device case or the cover.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view of the fuel supply apparatus to the engine which concerns on embodiment of this invention, and shows with the case lid removed. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a sectional view taken along line 4-4 of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, in FIG. 1 to FIG. 3, a fuel supply device for an engine for a motorcycle is designed to open and close a throttle body 1 having an intake passage 2 connected to an intake port (not shown) of the engine and the intake passage 2. A throttle valve 3 that is pivotally supported by the throttle body 1; an electric motor 4 that drives the throttle valve 3 to open and close; an electromagnetic fuel injection valve 5 that injects fuel into the intake passage 2 downstream from the throttle valve 3; An electric fuel pump 6 that pumps the fuel injection valve 5, a regulator 7 that adjusts the discharge pressure of the fuel pump 6 to a predetermined value, and a device case that houses the electric motor 4, the fuel injection valve 5 and the fuel pump 6. 8 and a holding member 9 for holding the fuel injection valve 5 and the fuel pump 6 in the device case 8, each of which will be sequentially described in detail.

  As shown in FIGS. 1 and 2, the throttle body 1 is integrally provided with a mounting flange 1a at the downstream end of the intake passage 2. The mounting flange 1a is bolted to a cylinder head of an engine (not shown). In the state, the intake passage 2 is disposed horizontally. The valve shaft 3a of the throttle valve 3 is also arranged horizontally, and both ends thereof are rotatably supported by bearing bosses 1b and 1c on the left and right side walls of the throttle body 1 via bearings 20a and 20b.

  The device case 8 is integrally formed with the throttle body 1 using a synthetic resin as a material. The device case 8 is disposed on the lower side of the throttle body 1 and extends in parallel with the valve shaft 3a. The device case 8 rises from one end portion of the first storage portion 10 and extends to one side of the throttle body 1 in the left-right direction. The side surface of the second housing portion 11 opposite to the throttle body 1 is an opening 12.

  The first housing portion 10 includes a small-diameter cylindrical portion 10 a that is closed at one end opposite to the second housing portion 11, and a large-diameter cylinder that continues to the other end of the small-diameter cylindrical portion 10 a and opens toward the second housing portion 11. The large-diameter cylindrical portion 10b is eccentric to the throttle body 1 side with respect to the small-diameter cylindrical portion 10a so that the side walls of both cylindrical portions 10a and 10b are continuous.

  A fuel inlet pipe 13 and a fuel outlet pipe 14 projecting outward from the closed end wall of the small-diameter cylindrical portion 10a are formed apart from each other. The fuel inlet pipe 13 is installed at a higher position than the throttle body 1. A fuel supply pipe 16 extending from the bottom of the fuel tank 15 of the motorcycle is connected, and a fuel return pipe 17 that opens into the fuel tank 15 is connected to the fuel outlet pipe 14.

  The fuel pump 6 is disposed inside the small diameter cylindrical portion 10a from the small diameter cylindrical portion 10a, and the holding member 9 is disposed in the second accommodating portion 11.

  The fuel pump 6 includes a cylindrical main barrel portion 6a, and a cylindrical positioning cylinder portion 6b that protrudes from the end surface of the main barrel portion 6a on the second accommodating portion 11 side, leaving an annular step portion 6c therearound. A fuel suction pipe 18 projects from the end surface of the main body 6a, and a fuel discharge pipe 19 projects from the end surface of the positioning cylinder 6b toward the second housing 11 side. A partition wall 21 in contact with the end surface and both side surfaces of the main body portion 6a is integrally formed on the inner wall of the first housing portion 10.

  The holding member 9 has a cylindrical first support portion 22 that is fitted to the inner peripheral surface of the large-diameter cylindrical portion 10b via a first seal member 23. The first seal member 23 is It is attached to an annular seal groove 24 formed on the outer peripheral surface of the first support portion 22. The first support portion 22 is provided with a first holding hole 26 fitted to the outer peripheral surface of the positioning cylinder portion 6b via an O-ring 25, and the O-ring 25 is formed by the annular step portion 6c. 1 is pushed into the annular recess 27 at the open end of the holding hole 26. The main body 6a is held in a contact position with the partition wall 21 on the end wall side of the small diameter cylindrical portion 10a by the repulsive force in the axial direction of the O-ring 25.

  As shown in FIG. 4, a part of the end surface of the first support portion 22 of the holding member 9 is supported by a support step portion 28 formed in the device case 8, and the first support portion 22 is attached to the support step portion 28. In order to hold the holding plate 29, which is in contact with the flange surface 22 a on the back surface of the first support portion 22, is fixed to the device case 8 by fastening bolts 30. It is hold | maintained in the predetermined position of the part 10 and the throttle body 1, respectively.

  Thus, the inside of the first accommodating portion 10 is divided into the first fuel chamber 10 c connected to the fuel inlet pipe 13 and the second fuel chamber 10 d connected to the fuel outlet pipe 14 by the partition wall 21 and the first support portion 22. The fuel intake pipe 18 is partitioned so as to open to the first fuel chamber 10c. A defoaming hole 31 provided in the end wall of the main body 6a of the fuel pump 6 opens into the second fuel chamber 10d. From this defoaming hole 31, vapor and bubbles generated in the fuel pump 6 are discharged.

  As shown in FIGS. 2 and 4, the fuel discharge pipe 19 is formed in a stepped shape with a small tip, and the fuel discharge pipe 19 is fitted in a stepped shape through a second seal member 33. A second holding hole 34 is provided on the inner end surface of the first holding hole 26. Accordingly, the second holding hole 34 is provided in the first support portion 22 similarly to the first holding hole 26. The second seal member 33 is disposed between the annular step portion 19 a of the fuel discharge pipe 19 and the annular step portion 34 a of the second holding hole 40.

  Thus, the fuel pressure discharged from the discharge pipe 19 acts in a direction in which the holding member 9 is separated from the fuel pump 6 along the axial direction, and the reaction causes the fuel pump 6 to move in the axial direction. Along the direction of contact with the partition wall 21. Therefore, even if the O-ring 25 is omitted, the fuel pump 6 can be pressed and supported on the partition wall 21 without play.

  A mounting boss 35 is integrally formed on the side wall of the throttle body 1 facing the second housing portion 11, and the nozzle cylinder portion 5 a of the fuel injection valve 5 is mounted in the mounting boss 35 via a third seal member 36. Is done. The fuel injection valve 5 includes the nozzle cylinder part 5a, the coil part 5b, and the fuel inlet cylinder part 5c from the front end side, and a power feeding coupler 37 is integrally projected on the outer peripheral surface of the coil part 5b.

  On the other hand, the holding member 9 has a cylindrical shape in which a third holding hole 41 is formed on the inside of the first support portion 22 and the outer periphery of the fuel inlet cylinder portion 5c of the fuel injection valve 5 via a fourth seal member 39. The second support portion 40 and a cylindrical connecting tube portion 42 that integrally connects the second support portion 40 to the first support portion 22 are molded into a single part with synthetic resin and connected. The hollow portion of the cylindrical portion 42 serves as a fuel passage 43 that connects between the second holding hole 40 and the third holding hole 41. Therefore, the fuel discharge pipe 19 of the fuel pump 6 and the fuel inlet cylinder portion 5 c of the fuel injection valve 5 are communicated with each other via the fuel passage 43. The fourth seal member 39 is attached to the outer peripheral groove of the fuel inlet cylinder 5c. The fuel passage 43 is formed by a core pin when the holding member 9 is molded, and the core pin insertion port 44 a is provided in an extension cylinder portion 44 that is integrally connected to the connection cylinder portion 42. A cap 45 that is snap-coupled to the outer periphery of the extension tube portion 44 is fitted into the insertion port 44a via the fifth seal member 46 and is closed. By the way, due to the presence of the extension cylinder portion 44, the cap 45 comes close to at least one inner wall of the device case 8 and a case lid 86 to be described later that closes the opening 12 thereof, and the inner wall is a core pin of the cap 45. It prevents the withdrawal from the insertion port 44a.

  In FIG. 2, the first support portion 22 includes a regulator mounting hole 50 that opens into the second fuel chamber 10 d, and a fuel branch passage 43 a that branches from an intermediate portion of the fuel passage 43 and reaches the regulator mounting hole 50. And the regulator 7 is mounted in the regulator mounting hole 50.

  The regulator 7 is fitted into the regulator mounting hole 50 via a sixth seal member 52, and a cylindrical regulator housing 54 that is prevented from being detached by a heat caulking portion 53 of the first support portion 22, and the regulator housing 54. A spherical valve body 56 which is accommodated in the regulator housing 54 and opens and closes the valve hole 55 connected to the fuel branch passage 43a of the regulator housing 54, and an umbrella-shaped valve pressing member 57 which can press the valve body 56 in the closing direction; , A retainer 58 that is press-fitted into the inner peripheral surface of the regulator housing 54 and slidably supports the rod portion of the valve pressing member 57, and is compressed between the retainer 58 and the valve pressing member 57, and has a predetermined set load. The pressure regulating spring 59 presses the pressing member 57 in the closing direction of the valve body 56. The retainer 58 is provided with a plurality of escape holes that open the regulator housing 54 to the second fuel chamber 10d side.

  In the above, the first accommodating portion 11, the mounting boss 35, the fuel pump 6, the fuel injection valve 5, the first and second support portions 22, 40, and the first, second and third holding holes 26, 34, 41 are , The axes are arranged so as to be parallel to each other.

  In FIG. 2, the second accommodating portion 11 is provided with an electric motor 4 for driving the throttle valve, in which the output shaft 4 a is parallel to the valve shaft 3 a of the throttle valve 3. The electric motor 4 is provided with brackets 61, 61 on one side surface, and the brackets 61, 61 and a distance collar 78 interposed therebetween are bolted 79 to the bottom wall 11 a of the second housing portion 11. The electric motor 4 is fixed to the second housing portion 11 by being fixed at the position. The output shaft 4a is connected to the valve shaft 3a via a reduction gear train 62. The reduction gear train 62 includes a pinion gear 63 that is fixed to the output shaft 4a, and a sector gear 64 that is fixed to the end of the valve shaft 3a protruding into the second housing portion 11 and meshes with the pinion gear 63. The rotation of 4a can be decelerated and transmitted to the valve shaft 3a.

  1 to 3, the holding member 9 and the electric motor 4 are formed with first and second support convex portions 65 and 66 that support the electronic circuit board 67, respectively. In the second housing portion 11, a terminal support block 68 that similarly supports the electronic circuit board 67 and an external coupler 69 protruding from the outer end of the terminal block 68 are integrally formed. A large number of coupler terminals 71, 71... Reaching the electronic circuit board 67 from the external coupler 69 are embedded and supported by insert molding. Power is supplied from the coupler terminals 71, 71... To the fuel pump 6, the electromagnetic fuel injection valve 5, and the electric motor 4 through the electronic circuit board 67.

  That is, as shown in FIGS. 3 and 4, a pair of bus bars 72, 72 are embedded in the connecting tube portion 42 and the first support portion 22 of the holding member 9 by insert molding. The bus bars 72, 72 are bent from one end of the linear portions 72a, 72a embedded in the connecting cylinder portion 42 and extending in the longitudinal direction thereof, and the stepped second holding holes 40. The bent portions 72b and 72b that pass through both sides and enter the first holding hole 26 and connectors 72c and 72c formed at the ends of the bent portions 72b and 72b are formed from the positioning cylinder portion 6b of the fuel pump 6. A pair of protruding pump terminals 87, 87 are inserted and connected. At the other end of the straight portions 72a and 72a, terminals 72d and 72d that are inserted and connected to the electronic circuit board 67 through the first support convex portion 65 are bent. Therefore, the fuel pump 6 is supplied with power from the electronic circuit board 67 through the bus bars 72 and 72. The bus bars 72, 72 can be embedded in the holding member 9 to simplify the electrical wiring to the fuel pump 6 and to enhance the rigidity of the holding member 9. Therefore, the fuel pump 6 and the fuel injection valve 5 can be firmly held by the strong holding member 9. In other words, toughness against fuel leakage from the fuel pump 6 and the fuel injection valve 5 can be ensured with a simple structure.

  Further, a plurality of forward / reverse energization terminals 73, 73... (Only one of them is shown in FIG. 2) are inserted and connected to the electronic circuit board 67 through the second support convex portion 66. . Therefore, the electric motor 4 is supplied with power from the electronic circuit board 67 through the forward and reverse energization terminals 73, 73...

  A female coupler 75 is fitted and connected to the coupler 37 of the fuel injection valve 5. A connector 77 is connected to the female coupler 75 via a lead wire 76, and the connector 77 is connected to the electronic circuit board 67. Therefore, the fuel injection valve 5 is supplied with power from the electronic circuit board 67 through the connector 77 and the lead wire 76.

  As shown in FIGS. 1 to 3, a box-shaped case cover 86 made of a synthetic resin and closing the opening 12 is joined to the end surface of the device case 8 with a seventh seal member 80 interposed therebetween. The seal member 80 is attached to a seal groove 81 formed on one joining surface of the device case 8 and the case lid 86. In the illustrated example, the device case 8 and the case lid 86 are joined by sandwiching the flanges 82 and 83 formed at their joining end portions by a plurality of clips 84, but welding is also possible. When the device case 8 and the case lid 86 are joined, a cushion member 85 such as urethane foam is interposed between the holding member 9 and the case lid 86, so that the holding member 9 cooperates with the fastening bolt 30. The fuel pump 6 and the fuel injection valve 5 can be held in a fixed position by being held in contact with the support step portion 28 of the device case 8.

  Next, the operation of this embodiment will be described.

  In assembling the fuel supply device to the engine, first, the regulator 7 is mounted in the regulator mounting hole 50 of the holding member 9, and the cap 45 that closes the core pin insertion port 44 a is snap-engaged with the extension cylinder portion 44. Further, the positioning cylinder portion 6b of the fuel pump 6 is fitted to the first holding hole 26 of the first support portion 22 of the holding member 9 via the O-ring 25, and at the same time, the fuel discharge pipe 19 of the fuel pump 6 is connected to the second holding hole. 34 is fitted through the second seal member 33, and the fuel inlet cylinder portion 5 c of the fuel injection valve 5 is fitted through the fourth seal member 39 into the third holding hole 41 of the second support portion 40. Thus, the fuel pump 6 and the fuel injection valve 5 are supported by the device case 8 in parallel with each other, and are in communication with each other via the fuel passage 43 inside the holding member 9.

  Next, the holding member 9 holding the fuel pump 6 and the fuel injection valve 5 in parallel with each other in this way is directed from the opening 12 of the device case 8 to the inside thereof, and the electromagnetic fuel pump 6 is moved to the small diameter of the first housing portion 10. The nozzle cylinder of the fuel injection valve 5 is inserted into the cylindrical portion 10a and the first support portion 22 of the device case 8 is fitted to the inner peripheral surface of the large-diameter cylindrical portion 10b via the first seal member 23. The portion 5 a is fitted to the mounting boss 35 of the throttle body 1 via the third seal member 36. At this time, since the first accommodating portion 11 and the mounting boss 35 are also arranged in parallel with each other, the fuel pump 6 and the fuel injection valve 5 and the holding member 9 holding them in parallel with each other are provided in one opening portion. 12 can be assembled to the throttle body 1 and the device case 8 at the same time along the same direction, and the assemblability is good. Further, even if there is a backlash in the axial direction at each fitting portion, fuel leakage from each fitting portion can be prevented by the presence of the seal members 23, 25, 33, and 39. As a result, a large dimensional error in the axial direction is allowed in each fitting portion, which facilitates manufacture and assembly, and can contribute to cost reduction. In addition, the first support portion 22 of the device case 8 is fitted to the inner peripheral surface of the large-diameter cylindrical portion 10b of the first housing portion 10 via the first seal member 23, so that the fuel pump in the first housing portion 10 is fitted. The first and second fuel chambers 10c and 10d can be defined around six.

  Next, a holding plate 29 that presses the holding member 9 against the support step portion 28 of the device case 8 is fixed by a fastening bolt 30. Thus, the fuel pump 6 and the fuel injection valve 5 are held by the holding member 9 at a predetermined position of the device case 8.

  The electric motor 4 is fixed to the bottom wall 11a of the second housing portion 11 of the device case 8 with bolts 79, and the pinion gear 63 of the output shaft 4a is engaged with the sector gear 64 of the valve shaft 3a.

  Thereafter, the electronic circuit board 67 is mounted on the first and second support protrusions 65 and 66 and the terminal support block 68 as described above, and then the case lid 86 is attached to the open end surface of the device case 8 via the seventh seal member 80. The case lid 86 is fixed to the device case 8 by a plurality of clips 84. At this time, the cushion member 85 is interposed between the holding member 9 and the case lid 86 as described above. Thus, since the opening 12 of the device case 8 is closed by the case lid 86, the fuel pump 6, the fuel injection valve 5, the electric motor 4, and the electronic circuit board 67 can be replaced by the cooperation of the device case 8 and the case lid 86. It can be reliably protected from contact with objects, and can also be protected from rainwater, dust, etc., thereby improving the durability of the fuel supply device to the engine.

  The fuel in the fuel tank 15 flows down the fuel supply pipe 16 and always fills the first fuel chamber 10 c in the device case 8 from the fuel inlet pipe 13. Therefore, when the fuel pump 6 is operated, the fuel in the first fuel chamber 10c is sucked from the fuel suction pipe 18, pressurized in the fuel pump 6, discharged from the fuel discharge pipe 19 to the fuel passage 43, and the fuel injection valve. 5 injects the fuel into the intake passage 2 of the throttle body 1 in an amount corresponding to the rotational speed of the engine and the opening of the throttle valve 3. The fuel injected into the intake passage 2 is supplied to the engine while being mixed with the intake air flowing through the intake passage 2.

  Meanwhile, since the pressure of the fuel passage 43, that is, the discharge pressure of the fuel pump 6 acts on the valve body 56 through the fuel branch passage 43a and the valve hole 55, the discharge pressure corresponds to a predetermined value corresponding to the set load of the pressure adjusting spring 59. Exceeding the above, the valve body 56 is opened, and the excess discharge pressure is discharged into the second fuel chamber 10d in the device case 8 through the valve hole 55 and the regulator housing 54, so that the discharge pressure becomes a predetermined value. Adjusted.

  Excess fuel discharged into the second fuel chamber 10d is returned from the fuel outlet pipe 14 to the fuel tank 15 through the fuel return pipe 17. During this time, when vapor is generated inside the fuel pump 6, the vapor is discharged from the defoaming hole 31 of the fuel pump 6 to the second fuel chamber 10 d, so that it rides on the flow of surplus fuel and enters the fuel tank 15. And can be discharged quickly.

  As described above, the device case 8 having the opening 12 on one side is integrally formed on the throttle body 1, and the fuel pump 6 and the fuel injection valve 5 are arranged in the device case 8 through the opening 12. Further, a holding member 9 for holding the fuel injection valve 5 and the fuel pump 6 is disposed in the device case 8 through the opening 12, and the fuel pump 6 and the fuel injection are disposed inside the holding member 9. Since the fuel passage 43 that communicates between the valves 5 is formed, the holding member 9 also serves as a fuel conduit. Therefore, no special piping for the fuel passage 43 is required, and a single device case 8 is used. Since the fuel pump 6 and the fuel injection valve 5 can be protected from contact with other objects, the structure of the fuel supply device to the engine can be effectively simplified, and the cost can be reduced. It can Kumishi.

  Further, since the regulator 7 is mounted on the holding member 9 that holds the fuel pump 6 and the fuel injection valve 5, a dedicated support member that supports the regulator 7 is not required, and surplus fuel discharged from the regulator 7 is Since the vapor is discharged from the fuel pump 6 and discharged to the second fuel chamber 10d in the first support portion 22, a dedicated passage for discharging excess fuel from the regulator 7 is unnecessary.

  Furthermore, since the regulator 7 is disposed on the holding member 9 by utilizing the dead space between the fuel pump 6 and the fuel injection valve 5, the holding member 9 can be prevented from being enlarged due to the mounting of the regulator 7, and the fuel can be prevented. The fuel branch path 43a branched from the middle portion of the fuel passage 43 between the pump 6 and the fuel injection valve 5 and reaching the inlet of the regulator 7 can be made extremely short, which also prevents the holding member 9 from being enlarged. Contribute to.

  When assembling the fuel supply device to the engine, the fuel injection valve 5 and the fuel pump 6 are first assembled to the throttle body 1 and the device case 8, and then the holding member 9 is attached to the fuel injection valve 5 and the fuel pump 6. Even when assembled, the same effects as described above can be obtained.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention.

  For example, when the fuel injection valve 5 is disposed in an exposed manner, the device case 8 is configured to accommodate only the fuel pump 6.

  The device case 8 can be molded separately from the throttle body 1 and then welded or bolted to the throttle body 1.

  Moreover, in the 1st accommodating part 10 of the device case 8, the partition 21 can be abolished and the 1st fuel chamber 10c and the 2nd fuel chamber 10d can mutually be connected, and can be comprised in one fuel chamber. In this case, the fuel inlet pipe 13 and the fuel intake pipe 18 are arranged at the lower part of the fuel chamber, the fuel outlet pipe 14 and the regulator 7 are arranged at the upper part of the fuel chamber, and the vapor or regulator 7 discharged from the fuel pump 6 is disposed. It is desirable to quickly discharge the excess fuel from the fuel outlet pipe 14 to the fuel tank 15.

  Further, if the fuel injection valve 5 is disposed obliquely with respect to the axis of the intake passage 2 so that the nozzle cylinder portion 5a is directed downstream of the intake passage 2, the fuel injection valve 5 mixes the injected fuel and the intake air in the intake passage 2. Can be improved. Also in this case, the fuel pump 6 is arranged in parallel to the fuel injection valve 5 in consideration of assemblability.

  Further, in the fuel injection valve 5, the fuel inlet cylinder portion 5 c is formed in a U shape, and the outer end side of the fuel inlet cylinder portion 5 c is fitted into the third holding hole 41 of the holding member 9, and the nozzle cylinder The portion 5a may be attached to an attachment boss 35 of the throttle body 1 formed to be inclined with respect to the axis of the intake passage 2.

DESCRIPTION OF SYMBOLS 1 ... Throttle body 2 ... Intake passage 3 ... Throttle valve 5 ... Fuel injection valve 5c ... Fuel inlet cylinder part 6 of a fuel injection valve .... Fuel pump 8 ... Device case 9 ... Holding member 12 ... Opening 15 of holding member ... Fuel tank 18 ... Fuel intake pipe 19 ... Fuel discharge pipe 22... Device case first support portion 33... Seal member (second seal member)
39 ··· Sealing member (fourth sealing member)
40 ... Second support part 43 of device case ... Fuel passage 43a ... Fuel branch 44a ... Core pin insertion port 45 ... Cap 72 ... Bus bar 86 ... ..Case lid

Claims (9)

A throttle body (1) having an intake passage (2) connected to an intake port of the engine; a throttle valve (3) pivotally supported by the throttle body (1) to open and close the intake passage (2); and the throttle body A fuel injection valve (5) mounted on (1) and injecting fuel into the intake passage (2), and an electric type attached to the throttle body (1) to supply fuel to the fuel injection valve (5) A fuel supply device for an engine comprising a fuel pump (6) of
A device case (8) that is integrally formed with the throttle body (1) and that accommodates the fuel pump (6) from the same direction as the direction in which the fuel injection valve (5) is attached to the throttle body (1). A holding member (9) for holding the fuel pump (6) in the device case (8) and holding the fuel injection valve (5) in the throttle body (1). 9) A fuel supply apparatus for an engine, characterized in that a fuel passage (43) for communicating the discharge pipe (19) of the fuel pump (6) with the fuel injection valve (5) is provided. The fuel supply device for an engine according to claim 1,
The device case (8) has an opening (12) on one side, and the fuel pump (6) is disposed in the device case (8) through the opening (12). A fuel supply device for an engine, characterized in that the fuel injection valve (5) to be mounted on the throttle body (1) is disposed through a section (12). The fuel supply device for an engine according to claim 1 or 2,
The holding member (9) supports the fuel injection valve (5) and a first support portion (22) fitted to the fuel discharge pipe (19) via a seal member (33) to support the fuel discharge pipe (19). The second support portion (40) fitted to the support member via the seal member (39) and the connecting cylinder portion (42) integrally connecting the first and second support portions (22, 40) to each other. The hollow portion of the connecting cylinder portion (42) is the fuel passage (43) communicating between the fuel discharge pipe (19) and the fuel injection valve (5). Feeding device. In the fuel supply apparatus to the engine in any one of Claims 1-3,
A bus bar (72) for supplying power to the fuel pump (6) is embedded in the holding member (9) by insert molding so that the bus bar (72) extends over the connecting cylinder portion (42) and the first support portion (22). A fuel supply device for the engine. The fuel supply device for an engine according to claim 2,
A fuel supply apparatus for an engine, wherein a case lid (86) for closing the opening (12) is joined to the device case (8). The fuel supply device for an engine according to claim 1 or 2,
The device case (8) is provided with a fuel chamber (10d) in communication with the fuel tank (15) and from which the vapor is discharged from the fuel pump (6), adjacent to the fuel pump (6), The device case (8) is equipped with a regulator (7) for discharging surplus fuel from the fuel passage (43) to the fuel chamber (10d) and adjusting the discharge pressure of the fuel pump (6). A fuel supply device to the engine. The fuel supply device for an engine according to claim 6,
The regulator (7) is disposed between the fuel pump (6) and the fuel injection valve (5), and branches to the holding member (9) from an intermediate portion of the fuel passage (43). A fuel supply device for the engine, characterized in that a fuel branch passage (43a) leading to the inlet of the engine is formed. The fuel supply device for an engine according to claim 5,
A fuel supply device for an engine, wherein the holding member (9) is held by the case lid (86). The fuel supply device for an engine according to claim 5 or 8,
The holding member (9) has a core pin insertion opening (44a) for forming the fuel passage (43), and a cap (45) for closing the core pin insertion opening (44a) is provided. The fuel supply device for the engine is characterized in that the escape is prevented by the inner wall of at least one of the device case (8) and the case lid (86).

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