JP2009007986A - Suction pipe for fuel injection pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suction pipe for a fuel injection pump 7 provided in a diesel engine, capable of enduring high pressure as spill pressure generated by backflow of high-pressure fuel in a plunger chamber 43 to a suction part 111 in a fuel pumping cycle and capable of preventing crack generation. <P>SOLUTION: This suction pipe 110 for the fuel injection pump 7 is so configured that a fuel supply port 36 as the fuel inlet of the fuel injection pump 7 communicates with a position separated from the fuel supply port 36 by a predetermined distance through the suction part 111 composed of steel pipes 113, 114, a throttle portion 113b is arranged at the end 113a of the suction part 111 on the side opposite to the fuel inlet, the end is inserted and fitted into a hose 6, and the hose 6 is tied to the steel pipe 113 by a clip 108. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technology of a fuel injection pump provided in a diesel engine. More specifically, the present invention relates to a configuration of a suction pipe for supplying fuel to the fuel injection pump.

Conventionally, a camshaft is driven by a crankshaft, a rolling element (roller) is brought into contact with a cam provided on the camshaft, and a plunger connected to the rolling element is slid to remove fuel from an intake portion. A technique of a fuel injection pump that sucks and discharges from a discharge part to a fuel injection nozzle via a high-pressure pipe is known (for example, see Patent Document 1).
JP 2004-270641 A

  In such a fuel pumping cycle of the fuel injection pump, the fuel pressurized by the plunger flows back to the hose connected to the suction portion through the suction portion of the fuel injection pump, and the high pressure is applied to the hose. This phenomenon occurs (this high pressure is called “spill pressure”). This spill pressure may cause cracks in the hose. Even when the hose has a strength that can withstand the spill pressure, the spill pressure may similarly cause cracks if the hose has deteriorated due to long-term use or the like. . Further, the hose and the clip for fixing the hose to the suction portion may rub against each other due to expansion, expansion, contraction, and vibration of the hose due to the generation of spill pressure, and a crack may occur from that portion.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection pump intake pipe capable of withstanding a spill pressure generated by the operation of a fuel injection pump and preventing the occurrence of cracks as described above.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to the first aspect, in the suction pipe connected to the fuel inlet of the fuel injection pump for supplying the fuel from the fuel tank to the fuel injection pump, the throttle member is disposed at a position away from the fuel inlet of the fuel injection pump. The throttle member and the fuel inlet are connected by a steel pipe.

  According to a second aspect of the present invention, the throttle member is integrally formed at the tip of the steel pipe on the side opposite to the fuel inlet.

  According to a third aspect of the present invention, in the intake pipe connected to the fuel inlet of the fuel injection pump for supplying fuel from the fuel tank to the fuel injection pump, the intake pipe between the fuel inlet of the fuel injection pump and the fuel tank is constituted by a joint. And a positioning member for determining a distance between the throttle member and the fuel inlet, and a throttle member inserted into the hose. It is arranged between the joints.

  According to a fourth aspect of the present invention, the positioning member is constituted by a pipe-shaped spacer, and the spacer is disposed in a hose between the throttle member and the joint.

  According to a fifth aspect of the present invention, the spacer and the throttle member are integrally formed.

  According to a sixth aspect of the present invention, the spacer and the joint are integrally formed.

  In claim 7, in the intake pipe connected to the fuel inlet of the fuel injection pump for supplying fuel from the fuel tank to the fuel injection pump, the intake pipe connected to the fuel inlet of the fuel injection pump is constituted by a steel pipe, A drawn portion is formed by drawing a position in the steel pipe away from the fuel inlet by a predetermined distance.

  As effects of the present invention, the following effects can be obtained.

  By comprising like 1st, durability can improve and generation | occurrence | production of the crack by deterioration and a spill pressure can be suppressed. In addition, maintenance can be simplified by improving durability.

  By comprising like Claim 2, durability improves and generation | occurrence | production of the crack by deterioration and a spill pressure can be suppressed. In addition, maintenance can be simplified by improving durability. Furthermore, since the number of parts can be reduced, it can be manufactured easily and the cost can be reduced.

  According to the third aspect of the present invention, a clip for inserting the throttle member into the hose and fixing it at a predetermined position can be omitted. Thereby, the crack which generate | occur | produces from the said clip part can be prevented.

  According to the fourth aspect of the present invention, a clip for inserting the throttle member into the hose and fixing it at a predetermined position can be omitted. Thereby, the crack which generate | occur | produces from the said clip part can be prevented. Moreover, the movement of the throttle member due to the spill pressure can be prevented simply by inserting the spacer into the hose, and the throttle member can be easily positioned.

  By comprising like 5th aspect, the clip for inserting a throttle member in a hose and fixing to a predetermined position can be abbreviate | omitted. Thereby, the crack which generate | occur | produces from the said clip part can be prevented. Moreover, since the number of parts can be reduced, it can be manufactured easily and the cost can be reduced.

  By configuring as in claim 6, it is possible to omit a clip for inserting the throttle member into the hose and fixing it in a predetermined position. Thereby, the crack which generate | occur | produces from the said clip part can be prevented. Moreover, since the number of parts can be reduced, it can be manufactured easily and the cost can be reduced.

  By configuring as in claim 7, the throttle part can be easily formed, and the durability of the throttle part can also be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

First, a configuration for supplying fuel to the fuel injection pump 7 will be described with reference to FIG.
The fuel stored in the fuel tank 1 flows to a fuel filter (filter) 3 through a hose 2 connected to a fuel outlet 1 a provided at the lower part of the fuel tank 1. The fuel from which fine impurities and the like have been removed by the fuel filter 3 flows to the fuel injection pump 7 through the hose 4, the three-way joint 5, and the hose 6. The fuel pressurized by the fuel injection pump 7 is pumped to the fuel injection nozzle 9 through the high-pressure pipe 8. The fuel pressure-fed to the fuel injection nozzle 9 is injected by the fuel injection nozzle 9 into a combustion chamber formed in the cylinder of the engine.

  Bubbles generated by air or spill pressure contained in the fuel in the hoses 4 and 6 return to the upper portion of the fuel filter 3 via the three-way joint 5 and the return hose 10. This air is contained in the fuel in the fuel filter 3 and surplus fuel returning from the fuel injection nozzle 9 to the upper portion of the fuel filter 3 via the return hose 11 and the fuel tank 3 via the fuel tank return hose 12. Return to.

  In addition, the “suction pipe” of the fuel injection pump in the present invention refers to a pipe that configures from the suction portion connected to the fuel inlet of the fuel injection pump to the three-way joint.

  Next, the configuration of the fuel injection pump 7 will be described with reference to FIGS. 2 and 3. In the following description, the direction of arrow A in FIG. 2 is defined as the upward direction of the fuel injection pump 7 in this embodiment.

  The camshaft 20 is supported in the crank chamber of the engine. The cam gear fitted on the camshaft 20 and the gear fitted on the crankshaft are in mesh with each other (not shown). The rotation of the crankshaft is transmitted to the camshaft 20 through the gears and the camshaft 20 rotates. A pump drive cam 21 is formed in the middle of the camshaft 20 and is in contact with the roller 22. The roller 22 is a rolling element that can rotate while contacting the pump drive cam 21. The roller 22 is rotatably fitted to the roller pin 23, and both ends of the roller pin 23 are pivotally supported by the roller tappet 24.

  The lower spring receiving member 25 is fitted in the roller tappet 24. The lower spring receiving member 25 is engaged with the lower end of the plunger 40 (the end on the camshaft 20 side). The lower spring receiving member 25 is biased downward (in the direction of the camshaft 20) by the plunger spring 26.

  The upper spring receiving member 27 is locked to the plunger barrel 35 by a pin 28. The upper spring receiving member 27 receives the plunger spring 26 on the plunger barrel 35 side.

  The mounting member 29 is fixed to the outer peripheral surface of the plunger barrel 35, and is fixed to a cylinder block (not shown) by mounting bolts or the like. Thereby, the fuel injection pump 7 is fixed to the main body (cylinder block).

  The plunger 40 is a substantially cylindrical member and is in sliding contact with the inner peripheral surface of the plunger barrel 35. A slot 42 is formed in a spiral on the outer peripheral surface of the plunger 40. The groove hole 42 communicates with a fuel escape hole 41 formed in the axial direction from the upper surface 40 a of the plunger 40.

  The suction portion 31 is provided on the side surface of the plunger barrel 35 and outside the cylinder block (not shown). The inner peripheral surface of the plunger barrel 35 and the suction passage 32 of the suction portion 31 are communicated with each other by a fuel supply port 36 that is a fuel inlet of the fuel injection pump 7.

  The plunger chamber 43 is a space formed by the inner peripheral surface of the plunger barrel 35 and the upper surface 40 a of the plunger 40. The communication member 45 is a member that communicates the plunger chamber 43 and the discharge portion 55.

An outlet valve 50 is accommodated inside the discharge unit 55. The outlet valve 50 is biased downward (on the camshaft 20 side) by the outlet valve spring 51, and is seated on the upper end portion of the communication member 45 to block between the plunger chamber 43 and the discharge portion 55. .
The high-pressure pipe 8 is connected to the upper end portion of the discharge portion 55 through a connection member 56 and a seal member 57.

  Hereinafter, a fuel pressure feeding cycle by the fuel injection pump 7 having the configuration shown in FIGS. 2 and 3 will be described.

  When the cam shaft 20 rotates, the roller 22 that contacts the pump drive cam 21 formed in the middle of the cam shaft 20 moves up and down along the outer peripheral shape of the pump drive cam 21. By this movement, the plunger 40 slides up and down in the plunger barrel 35 via the roller pin 23, the roller tappet 24, and the lower spring receiving member 25. By this sliding movement, the fuel stored in the fuel tank 1 is sucked into the fuel injection pump 7 and supplied to the fuel injection nozzle 9 through the high-pressure pipe 8.

  Specifically, when the plunger is lowered most, the upper surface 40a of the plunger 40 is located below the fuel supply port 36 that is a fuel inlet, and flows from the fuel tank 1 through the fuel filter 3 and the like. The fuel flows from the suction passage 32 of the suction portion 31 into the plunger chamber 43 through the fuel supply port 36.

When the camshaft 20 rotates and the plunger 40 slides upward and the upper surface 40a of the plunger 40 is positioned above the upper end of the fuel supply port 36, the fuel supply port 36 and the plunger chamber 43 are Is cut off.
When the plunger 40 slides upward, the fuel in the plunger chamber 43 is compressed and the pressure in the plunger chamber 43 increases. When the pressure in the plunger chamber 43 becomes equal to or higher than a predetermined pressure, the outlet valve 50 slides upward against the biasing force of the outlet valve spring 51. As a result, the plunger chamber 43 and the discharge portion 55 communicate with each other, and the fuel is pumped from the high pressure pipe 8 to the fuel injection nozzle 9.

When the plunger 40 slides further upward, a slot 42 formed in a spiral shape on the outer peripheral surface of the plunger 40 communicates with the fuel supply port 36. Since the groove hole 42 communicates with the fuel escape hole 41 formed in the axial direction from the upper surface 40 a of the plunger 40, the plunger chamber 43 and the suction passage 32 of the suction portion 31 communicate with each other.
As a result, the high-pressure fuel in the plunger chamber 43 flows back to the suction passage 32 of the suction portion 31. At this time, the inside of the suction passage 32 rapidly becomes a high pressure. This pressure is called “spill pressure”.

  When the high-pressure fuel in the plunger chamber 43 flows back to the suction passage 32 of the suction portion 31, the pressure in the plunger chamber 43 decreases, and the outlet valve 50 slides downward and communicates with the urging force of the outlet valve spring 51. It sits on the upper end of the member 45. As a result, the plunger chamber 43 and the discharge portion 55 are again disconnected from each other, and the fuel pressure is stopped.

  When the plunger 40 slides downward and the upper surface 40a of the plunger 40 comes again below the fuel supply port 36, the fuel from the fuel tank 1 passes through the fuel supply port 36 from the intake passage 32 of the intake portion 31 and moves into the plunger chamber. 43 flows into.

  By repeating the pressure feeding cycle as described above, the fuel injection pump 7 pumps a predetermined amount of fuel to the fuel injection nozzle 9 at a predetermined timing.

  One embodiment of the suction pipe according to the present invention in the fuel injection pump 7 configured as described above will be described with reference to FIG.

  As shown in FIG. 4, a throttle member 105 is provided at a predetermined distance from the fuel supply port 36 that is the fuel inlet of the fuel injection pump 7, and a steel pipe is provided between the throttle member 105 and the fuel supply port 36 that is the fuel inlet. It is connected by the constructed suction part 101. The suction pipe 100 of the fuel injection pump 7 includes a suction portion 101, a throttle member 105, a connection member 106, a seal member 107, a clip 108, a hose 6, and the like.

  The suction part 101 is composed of steel pipes 103 and 104. One end of the steel pipe 104 is connected to the plunger barrel 35 and the other end is connected to the steel pipe 103 perpendicularly to the steel pipe 104. With this configuration, the fuel supply port 36 that is a fuel inlet and the throttle member 105 are communicated with each other through the suction passage 102 of the suction portion 101.

  An end 103a of the steel pipe 103 on the hose 6 side extends to a position away from the fuel supply port 36, which is a fuel inlet, by a predetermined distance. The end portion 103 a is connected to the throttle member 105 through a connection member 106 and a seal member 107. The end of the throttle member 105 on the hose 6 side is fitted into the hose 6, and the hose 6 is locked to the throttle member 105 by a clip 108 so that the hose 6 does not fall off. The material of the diaphragm member 105 is not limited, and may be formed of a material having sufficient strength and corrosion resistance such as metal or resin.

Here, the operation of the diaphragm member 105 will be described.
As described above, the spill pressure is generated in the fuel pumping cycle of the fuel injection pump 7. When the spill pressure is generated, the pressure in the plunger chamber 43 of the fuel injection pump 7 rapidly decreases, so that a large amount of bubbles are generated, resulting in fuel supply failure. In order to prevent this, the throttle member 105 is provided at a position away from the fuel supply port 36 which is a fuel inlet by a predetermined distance. That is, by providing the throttle member 105, the pressure in the suction passage 102 of the suction portion 101 when the spill pressure is generated is increased, and bubbles are discharged to the upstream side (the hose 6 side) of the throttle member 105 by the pressure. Further, the throttle member 105 prevents bubbles discharged to the upstream side of the throttle member 105 from flowing into the suction passage 102 again. As shown in FIG. 1, the bubbles discharged to the upstream side of the throttle member 105 pass through the fuel hose 6, the three-way joint 5, the return hose 10, the upper part of the fuel filter 3, the fuel tank return hose 12, and the fuel tank 1. Return to.

A predetermined distance between the fuel supply port 36 and the throttle member 105 will be described.
In the present invention, the “predetermined distance” is a distance between the fuel supply port 36 and the throttle member or the throttle part, and is necessary for increasing the pressure in the suction passage and discharging bubbles to the upstream side of the throttle member. Distance.
In this embodiment, by disposing the throttle member 105 at a position separated from the fuel supply port 36 by a predetermined distance, the pressure in the suction passage 102 when the spill pressure is generated is discharged to the upstream side of the throttle member 105. The pressure is increased to an appropriate level. When the throttle member 105 is separated from the fuel supply port 36 by a predetermined distance or more, the pressure in the suction passage 102 when the spill pressure is generated decreases, and the generated bubbles cannot be sufficiently discharged to the upstream side of the throttle member 105. A supply failure may occur. Further, when the distance between the fuel supply port 36 and the throttle member 105 is configured to be a predetermined distance or less, the pressure in the suction passage 102 when the spill pressure is generated increases, and the suction pipe 100 and the suction passage 102 are configured by the pressure. The member may be damaged. Therefore, when the distance between the fuel supply port 36 and the throttle member 105 is set to be equal to or smaller than a predetermined distance, the suction pipe 100 and the suction passage 102 are made of a member having sufficient strength to withstand the pressure increase in the suction passage 102. Need to be configured.
The “predetermined distance” between the fuel supply port 36 and the throttle member is a distance obtained by experiments or the like. In addition, it is possible to shorten the “predetermined distance” by configuring the pipe between the fuel supply port 36 and the throttle member with a high strength member such as a steel pipe or increasing the volume (diameter). is there.

  In this embodiment, the end 103a of the steel pipe 103 on the hose 6 side is connected to the throttle member 105 through the connection member 106 and the seal member 107, but the present invention is not limited to this. For example, a configuration in which the end portion 103a of the steel pipe 103 is directly connected to the throttle member 105 by brazing or the like may be used.

  By configuring as in the present embodiment, bubbles generated by spill pressure and air contained in the fuel can be discharged to the upstream side of the throttle member 105, and fuel supply failure due to air mixing can be prevented. . In addition, by connecting the fuel supply port 36, which is a fuel inlet, and the throttle member 105 in communication with each other by a suction portion 101 made of a steel pipe, the durability of the suction portion 101 is improved, and cracks due to deterioration or spill pressure are improved. Occurrence can be suppressed. Moreover, maintenance can be simplified by improving durability.

  Another embodiment of the suction pipe according to the present invention in the fuel injection pump 7 configured as described above will be described with reference to FIG.

  As shown in FIG. 5, the suction port 111 made of a steel pipe communicates with a position a predetermined distance away from the fuel supply port 36 which is the fuel inlet of the fuel injection pump 7, and the tip of the suction port 111 on the side opposite to the fuel inlet side The diaphragm member is integrally formed. The suction pipe 110 of the fuel injection pump 7 includes a suction part 111, a clip 108, a hose 6 and the like.

  The suction part 111 is composed of steel pipes 113 and 114. One end of the steel pipe 114 is connected in communication with the plunger barrel 35, and one end of the steel pipe 113 is connected in communication with the other end perpendicular to the steel pipe 114. The other end of the steel pipe 113 is extended to a position away from the fuel supply port 36, which is a fuel inlet, by a predetermined distance, and a throttle portion 113b is provided at the tip 113a. That is, the above-described throttle member 105 is integrally provided at the tip 113a of the steel pipe 113 on the anti-fuel inlet side (hose 6 side). In this case, the narrowed portion 113b is formed by injection molding or the like when it is made of synthetic resin, and when made of metal, it is drilled with a drill or the like after the tip is closed. Alternatively, the shaft center portion of the bar is drilled. The tip 113a of the steel pipe 113 on the side opposite to the fuel inlet is inserted into the hose 6, and the hose 6 is secured to the steel pipe 113 by a clip 108 so that it does not fall off. With this configuration, the fuel supply port 36 that is a fuel inlet and the hose 6 are communicated with each other through the suction passage 112 of the suction portion 111.

  By configuring as in the present embodiment, bubbles generated by spill pressure and air contained in the fuel can be discharged to the upstream side of the throttle portion 113b, and fuel supply failure due to air mixing can be prevented. . Further, the fuel supply port 36 as a fuel inlet and the hose 6 are connected to each other by a suction portion 111 made of a steel pipe, so that the durability of the suction portion 111 is improved and cracking due to deterioration or spill pressure occurs. Can be suppressed. Moreover, maintenance can be simplified by improving durability. Further, by providing the throttle portion 113b at the tip 113a on the anti-fuel inlet side of the steel pipe 113, the number of parts can be reduced, so that it can be easily manufactured and the cost can be reduced.

Moreover, as shown in FIG. 6, it is also possible to provide the drawn part 113b by drawing (spinning) the tip 113a of the steel pipe 113.
With this configuration, it is not necessary to perform complicated processing such as cutting (drilling with a drill) in order to provide the narrowed portion 113b, and the cost can be reduced. Further, the hose 6 is fastened to the steel pipe 113 by using the clip 109 having substantially the same cross-sectional shape as the throttle groove 113 c formed on the outer periphery of the throttle portion 113 b of the steel pipe 113, thereby fixing the hose 6 to the steel pipe 113 more firmly. It becomes possible.

  Another embodiment of the suction pipe according to the present invention will be described with reference to FIG.

  As shown in FIG. 7, a branch passage constituted by a three-way joint 5 is arranged in the suction pipe 120 between the fuel supply port 36 that is a fuel inlet of the fuel injection pump 7 and the fuel tank 1, and the three-way joint 5 and the fuel supply port are arranged. 36 is communicated by the hose 6, the throttle member 121 is inserted into the hose 6, and the spacer 122 which is a positioning member for determining the distance between the throttle member 121 and the fuel supply port 36 is connected to the throttle member 121 and the three-way joint. It is set as the structure arrange | positioned in the hose 6 between five. The suction pipe 120 of the fuel injection pump 7 includes a suction portion 31, a hose 6, a clip 108, a throttle member 121, a spacer 122, and a three-way joint 5.

One end of the suction passage 32 of the suction portion 31 is connected to the fuel supply port 36 in communication. The other end of the suction passage 32 is connected to the end portion 5 b of the three-way joint 5 by the hose 6. The hose 6 is fixed to the suction portion 31 and the three-way joint 5 by clips 108 and 108. A throttle member 121 is inserted in the hose 6 at a position away from the fuel supply port 36 by a predetermined distance. In the hose 6 between the throttle member 121 and the three-way joint 5, a pipe-shaped spacer 122 that is a positioning member for determining the distance between the throttle member 121 and the fuel supply port 36 is disposed. The longitudinal length of the spacer 122 is substantially the same as the distance between the throttle member 121 and the three-way joint 5. The hose 4 is connected to the end 5a of the three-way joint 5, and the return hose 10 is connected to the end 5c by clips 108 and 108, respectively.
In such a configuration, the fuel stored in the fuel tank 1 flows into the fuel injection pump 7 via the hose 4 and the suction pipe 120 and is pumped to the fuel injection nozzle 9 via the high-pressure pipe 8 by the fuel injection pump 7. Be done

  When the pressure in the suction passage 32 of the suction portion 31 increases due to the spill pressure, a force is applied to the throttle member 121 from the suction portion 31 side of the hose 6 toward the three-way joint 5 side. Thereby, the throttle member 121 tries to move in the hose 6 toward the three-way joint 5 side. In order to prevent this, there is a method of fixing the throttle member 121 at a predetermined position by tightening a portion where the throttle member 121 is arranged from the outside of the hose 6 with a clip. However, the hose 6 and the clip may rub against each other due to expansion, contraction, and vibration of the hose 6 due to spill pressure, and the hose 6 may crack from that portion. However, by disposing the spacer 122 between the throttle member 121 and the three-way joint 5 as in this embodiment, the movement of the throttle member 121 can be prevented without using the clip.

  By configuring as in the present embodiment, a clip for fixing the throttle member 121 at a position away from the fuel supply port 36 by a predetermined distance becomes unnecessary, and cracks generated from the clip fixing position can be prevented. Also in the manufacturing process, the throttle member 121 can be easily positioned by inserting the throttle member 121, the spacer 122, and the end portion 5b of the three-way joint 5 in this order from the end of the hose 6 on the three-way joint 5 side. .

  In this embodiment, the spacer 122 is used as a positioning member for determining the distance between the throttle member 121 and the fuel supply port 36. However, the present invention is not limited to this, and the throttle member 121 is disposed inside the hose 6. Any member that can prevent movement to the three-way joint 5 side may be used.

  Another embodiment of the suction pipe according to the present invention will be described with reference to FIG.

  As shown in FIG. 8, a branch passage constituted by the three-way joint 5 is arranged in the suction pipe 130 between the fuel supply port 36 that is a fuel inlet of the fuel injection pump 7 and the fuel tank 1, and the three-way joint 5 and the fuel supply port are arranged. 36 is communicated by a hose 6, and a throttle member 131 in which a spacer is integrally formed is inserted into the hose 6. The suction pipe 130 of the fuel injection pump 7 includes a suction portion 31, a hose 6, a clip 108, a throttle member 131, and a three-way joint 5.

  One end of the suction passage 32 of the suction portion 31 is connected to the fuel supply port 36 in communication. The other end of the suction passage 32 is connected to the end portion 5 b of the three-way joint 5 by the hose 6. The hose 6 is fixed to the suction portion 31 and the three-way joint 5 by clips 108 and 108. In addition, a throttle member 131 is inserted into the hose 6. The aperture member 131 is a member in which an aperture portion 131a and a spacer portion 131b are integrally formed. The throttle portion 131a is disposed at a predetermined distance from the fuel supply port 36, and the longitudinal length of the spacer portion 131b is substantially the same as the distance between the throttle portion 131a and the end portion 5b of the three-way joint 5. Has been. The throttle member 131 is inserted into the hose 6 with the throttle part 131a facing the suction part 31 and the spacer 131b facing the three-way joint 5 side.

  By configuring as in the present embodiment, a clip for fixing the throttle member 131 at a position away from the fuel supply port 36 by a predetermined distance becomes unnecessary, and cracks generated from the clip fixing position can be prevented. Moreover, since the number of parts can be reduced by using the aperture member 131 in which the aperture portion 131a and the spacer portion 131b are integrally formed, the number of components can be reduced, and the cost can be reduced. it can.

It is also possible to provide the drawn portion 131a by drawing the drawn member 131.
With this configuration, it is not necessary to perform complicated processing such as cutting to provide the narrowed portion 113b, and cost can be reduced.

  Another embodiment of the suction pipe according to the present invention will be described with reference to FIG.

As shown in FIG. 9, a branch passage constituted by a three-way joint 142 in which a spacer is integrally formed is arranged in a suction pipe 140 between a fuel supply port 36 that is a fuel inlet of the fuel injection pump 7 and the fuel tank 1. The three-way joint 142 and the fuel supply port 36 are communicated with each other by the hose 6, and the throttle member 141 is inserted into the hose 6. The intake pipe 140 of the fuel injection pump 7 includes an intake portion 31, a hose 6, a clip 108, a throttle member 141, and a three-way joint 142.
One end of the suction passage 32 of the suction portion 31 is connected to the fuel supply port 36 in communication. The other end of the suction passage 32 is connected to the end portion 142 b of the three-way joint 142 by the hose 6. The hose 6 is fixed to the suction portion 31 and the three-way joint 142 by clips 108 and 108. A throttle member 141 is inserted into the hose 6. A spacer 142d is integrally formed with the end 142b of the three-way joint 142. The throttle member 141 is disposed at a position away from the fuel supply port 36 by a predetermined distance, and the spacer portion 142 d formed in the three-way joint 142 extends to a position in contact with the throttle member 141.

  By configuring as in the present embodiment, a clip for fixing the throttle member 141 at a position away from the fuel supply port 36 by a predetermined distance becomes unnecessary, and cracks generated from the clip fixing position can be prevented. Moreover, since the number of parts can be reduced by using the three-way joint 142 in which the spacer portion 142d is integrally formed, it can be easily manufactured, and the cost can be reduced.

  In the present invention, the three-way joint may be a two-way joint or a four-way joint, and is not limited as long as the position of the throttle can be determined, and depending on the type of joint, the branching position is further upstream. It can also be arranged.

The schematic diagram which shows the outline | summary of the supply path | route of fuel. Side surface sectional drawing which shows a fuel-injection pump. The front view which shows a fuel injection pump. 1 is a partial front cross-sectional view showing a suction pipe according to an embodiment of the present invention. 1 is a partial front cross-sectional view showing a suction pipe according to an embodiment of the present invention. 1 is a partial front cross-sectional view showing a suction pipe according to an embodiment of the present invention. 1 is a partial front cross-sectional view showing a suction pipe according to an embodiment of the present invention. 1 is a partial front cross-sectional view showing a suction pipe according to an embodiment of the present invention. 1 is a partial front cross-sectional view showing a suction pipe according to an embodiment of the present invention.

Explanation of symbols

6 Hose 7 Fuel Injection Pump 8 High Pressure Pipe 30 Suction Pipe 35 Plunger Barrel 36 Fuel Supply Port 111 Suction Part 113 Steel Pipe 113b Throttle Part 114 Steel Pipe

Claims (7)

In the suction pipe connected to the fuel inlet of the fuel injection pump for supplying fuel from the fuel tank to the fuel injection pump,
A suction pipe for a fuel injection pump, characterized in that a throttle member is provided at a position away from a fuel inlet of the fuel injection pump by a predetermined distance and a steel pipe is connected between the throttle member and the fuel inlet. The suction pipe of the fuel injection pump according to claim 1, wherein the throttle member is integrally formed at a tip of the steel pipe on the side opposite to the fuel inlet. In the suction pipe connected to the fuel inlet of the fuel injection pump for supplying fuel from the fuel tank to the fuel injection pump,
A branch passage constituted by a joint is arranged in a suction pipe between a fuel inlet and a fuel tank of a fuel injection pump, the joint and the fuel inlet are communicated by a hose, and a throttle member is inserted into the hose. A suction pipe for a fuel injection pump, wherein a positioning member for determining a distance between the member and the fuel inlet is disposed between the throttle member and the joint. The intake pipe of the fuel injection pump according to claim 3, wherein the positioning member is constituted by a pipe-shaped spacer, and the spacer is disposed in a hose between the throttle member and the joint. The intake pipe of the fuel injection pump according to claim 3, wherein the spacer and the throttle member are integrally formed. The intake pipe of the fuel injection pump according to claim 3, wherein the spacer and the joint are integrally formed. In the suction pipe connected to the fuel inlet of the fuel injection pump for supplying fuel from the fuel tank to the fuel injection pump,
A suction pipe for a fuel injection pump, wherein a suction pipe connected to a fuel inlet of the fuel injection pump is formed of a steel pipe, and a throttle portion is formed by drawing a position away from the fuel inlet in the steel pipe by a predetermined distance.

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