JP2009007987A - 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 preventing rotation malfunction by discharging to the upstream side of a throttle member, the large amount of bubbles generated by backflow of high-pressure fuel in a plunger chamber 43 to the suction passage 32 of a suction part 31 in a fuel pumping cycle. <P>SOLUTION: This suction pipe 110 for the fuel injection pump 7 is so configured that the substantially cylindrical throttle member 111 formed with a ring-shaped projecting part 111c arranged around the peripheral part of an end part 111b as the end on the side of a fuel inlet is provided in a position which is the halfway part of the suction pipe 110 connected to a fuel supply port 36 as the fuel inlet of the fuel injection pump 7 and is separated from the fuel supply port 36 by a predetermined distance. <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).
Further, in such a fuel pumping cycle by the fuel injection pump, the fuel pressurized by the plunger flows back to the hose connected to the suction portion via the suction portion of the fuel injection pump, and the hose (This spill pressure is called “spill pressure”). Along with the generation of the spill pressure, the pressure in the fuel injection pump rapidly decreases, and a large amount of bubbles are generated. In some cases, the bubbles are pumped together with the fuel to the fuel injection nozzle by the operation of the fuel injection pump, causing engine malfunction. In order to prevent this, a technique is also known in which a throttle member is provided in the middle of the suction pipe of the fuel injection pump, and air bubbles are discharged to the upstream side (fuel tank side) of the throttle member provided in the suction pipe. It has become.
JP 2004-270641 A

However, in the structure as described above, the throttle member may move upstream due to the pressure of the spill pressure. As a result, the bubbles in the fuel cannot be sufficiently discharged, and engine malfunction may occur.
In addition, a throttle member having a shape that simply reduces the flow path area in the pipe cannot sufficiently discharge bubbles in the fuel, which may cause engine malfunction.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection pump suction pipe that discharges bubbles in the fuel to the upstream side of the throttle member as described above and prevents engine malfunction.

  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, the suction pipe is connected to the fuel inlet of the fuel injection pump for supplying the fuel from the fuel tank to the fuel injection pump, and the throttle member is disposed at a position away from the fuel inlet by a predetermined distance. In the pipe, the suction pipe is constituted by a hose, a throttle member is inserted into the hose, the throttle member is substantially cylindrical, and ring-shaped convex portions are formed at the outer peripheral portions at both axial ends. It is.

  According to a second aspect of the present invention, there is provided an intake pipe in which a suction pipe is connected to a fuel inlet of a fuel injection pump for supplying fuel from a fuel tank to the fuel injection pump, and a throttle member is disposed at a predetermined distance from the fuel inlet. The suction pipe is constituted by a hose, a throttle member is inserted into the hose, the throttle member is substantially cylindrical, and a ring-shaped convex portion is formed on the outer peripheral portion of the fuel inlet side end. is there.

  According to a third aspect of the present invention, the convex portion is formed in a substantially triangular shape in cross section.

  According to a fourth aspect of the present invention, in the suction pipe, the suction pipe is connected to the fuel inlet of the fuel injection pump for supplying the fuel from the fuel tank to the fuel injection pump, and the throttle member is arranged at a predetermined distance from the fuel inlet. The throttle hole formed in the axial center portion of the throttle member has a configuration in which the cross-sectional area on the fuel inlet side is large and the cross-sectional area gradually decreases toward the other side.

  According to a fifth aspect of the present invention, in the suction pipe, the suction pipe is connected to the fuel inlet of the fuel injection pump for supplying the fuel from the fuel tank to the fuel injection pump, and the throttle member is arranged at a predetermined distance from the fuel inlet. The throttle hole formed in the axial center portion of the throttle member is provided in a pair of upper and lower, the upper throttle hole has a large sectional area on the fuel inlet side, the other side is small, and the lower throttle hole has a sectional area on the fuel inlet side. The configuration is small and the other side is large.

  According to a sixth aspect of the present invention, 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 throttle member is integrally provided in the suction portion of the suction pipe, A suction pipe is connected.

  According to a seventh aspect of the present invention, another throttle member is disposed in the suction pipe that is separated from the throttle member by a predetermined distance.

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

  By configuring as in claim 1, it is possible to prevent the throttle member from moving due to the spill pressure. In addition, the hose does not rub against the clip that fixes the throttle member due to the expansion, expansion, contraction, and vibration of the hose due to the spill pressure, and the occurrence of cracks can be prevented.

  By configuring as in claim 2, it is possible to prevent the throttle member from moving due to the spill pressure. In addition, the hose does not rub against the clip that fixes the throttle member due to the expansion, expansion, contraction, and vibration of the hose due to the spill pressure, and cracks can be prevented from occurring. Furthermore, the diaphragm member can be formed in a simple shape and can be easily manufactured.

  By configuring as in claim 3, it is possible to prevent the throttle member from moving due to the spill pressure. In addition, the hose does not rub against the clip that fixes the throttle member due to the expansion, expansion, contraction, and vibration of the hose due to the spill pressure, and cracks can be prevented from occurring. Furthermore, since the shape of the diaphragm member is simplified, it can be easily manufactured.

  By configuring as in claim 4, the generated bubbles can be easily discharged to the upstream side of the throttle member, and the discharged bubbles can hardly be returned to the downstream side of the throttle member.

  By configuring as in the fifth aspect, the generated bubbles can be easily discharged to the upstream side of the throttle member through the upper throttle hole, and the discharged bubbles can hardly be returned to the downstream side of the throttle member.

  According to the sixth aspect of the present invention, the throttle member can be integrally formed on the fuel injection pump side, so that the assembly becomes easy and the hose is not cracked.

  By configuring as in claim 7, even when the pressure on the downstream side of the throttle member is low, the bubbles can be smoothly discharged. Thereby, it becomes possible to easily restart after burnout.

  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 the fuel filter 3 through the hose 2 connected to the fuel outlet 1a 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 a predetermined pressure or more, 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.

  An 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 FIGS.

  As shown in FIG. 4, a suction pipe 100 is connected to a fuel supply port 36 that is a fuel inlet of the fuel injection pump 7 for supplying fuel from the fuel tank 1 to the fuel injection pump 7, and a predetermined distance from the fuel supply port 36. In the suction pipe 100 in which the throttle member 101 is disposed at a distant position, the suction pipe 100 is constituted by a hose 6 or the like, the throttle member 101 is inserted into the hose 6, and the throttle member 101 is substantially cylindrical and has a shaft thereof. Ring-shaped convex portions are formed on the outer peripheral portions at both ends in the center direction. A suction pipe 100 of the fuel injection pump 7 includes a suction portion 31, a hose 6, a throttle member 101, a clip 60, and a three-way joint 5.

The upstream end of the suction part 31 is inserted into the downstream end of the hose 6, and the hose 6 is locked by a clip 60 so as not to fall off. The fuel supply port 36 and the hose 6 are communicated with each other by the suction passage 32 of the suction portion 31.
A throttle member 101 is inserted in the hose 6 at a position away from the fuel supply port 36 by a predetermined distance. The throttle member 101 is secured to the midway portion thereof from the outer periphery of the hose 6 by a clip 60.
The end portion 5 b of the three-way joint 5 is inserted into the upstream end portion of the hose 6 and is locked by a clip 60. 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 60 and 60, respectively.
In such a configuration, the fuel stored in the fuel tank 1 flows into the fuel injection pump 7 through the hose 4 and the suction pipe 100, and is pumped to the fuel injection nozzle 9 through the high-pressure pipe 8 by the fuel injection pump 7. Be done

As shown in FIGS. 5A and 5B, the diaphragm member 101 has a substantially cylindrical shape, and ring-shaped convex portions 101a and 101a are formed on the outer peripheral portions at both axial ends. The convex portions 101a and 101a are formed in a substantially triangular shape in sectional view passing through the axis.
The material of the diaphragm member 101 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 101 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 101 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 101, the pressure in the suction passage 32 of the suction portion 31 when the spill pressure is generated is increased, and bubbles are discharged to the upstream side of the throttle member 101 by the pressure. Further, the throttle member 101 prevents bubbles discharged to the upstream side of the throttle member 101 from flowing into the suction passage 32 again. As shown in FIG. 1, the bubbles discharged to the upstream side of the throttle member 101 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 101 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 101 at a position separated from the fuel supply port 36 by a predetermined distance, the pressure in the suction passage 32 when the spill pressure is generated is discharged to the upstream side of the throttle member 101. The pressure is increased to an appropriate level. When the throttle member 101 is separated from the fuel supply port 36 by a predetermined distance or more, the pressure in the suction passage 32 when the spill pressure is generated decreases, and the generated bubbles cannot be sufficiently discharged to the upstream side of the throttle member 101. A supply failure may occur. Further, when the distance between the fuel supply port 36 and the throttle member 101 is set to a predetermined distance or less, the pressure in the suction passage 32 when the spill pressure is generated rises, 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 101 is set to a predetermined distance or less, 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 32. 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.

By configuring as in this embodiment, it is possible to prevent the throttle member 101 from moving upstream due to the spill pressure. That is, the throttle member 101 is firmly fitted to the inner peripheral surface of the hose 6 by the ring-shaped convex portions 101 a and 101 a provided on the throttle member 101. Furthermore, the diaphragm member 101 can be more reliably fixed by connecting the convex portion 101a on the one end side and the convex portion 101a on the other end side with the clip 60 from the outer periphery of the hose 6.
Further, the spill pressure is blocked by the ring-shaped convex portions 101a and 101a provided on the throttle member 101, and the hose 6 does not rub against the clip 60 that fixes the throttle member 101 due to expansion, expansion, contraction, and vibration of the hose 6. Generation of cracks can be prevented.

Further, the suction pipe 110 can be configured as shown in FIG. 6 by using a throttle member configured as shown in FIGS. 5 (c) and 5 (d).
That is, as shown in FIGS. 5C and 5D, the throttle member 111 has a substantially cylindrical shape, and a ring-shaped convex portion 111c is formed on the outer peripheral portion of the end portion 111b that is the end on the fuel inlet side. is doing. The convex portion 111c is formed in a substantially triangular shape in sectional view.
As shown in FIG. 6, the end 111a of the throttle member 111 faces the upstream side, the end 111b having the convex portion 111c faces the downstream side, and is in the hose 6 at a position away from the fuel supply port 36 by a predetermined distance. It is locked by the clip 60.

  By configuring as shown in FIG. 6, the shape of the diaphragm member 111 is simple and can be easily manufactured. Thereby, cost reduction can be achieved. Further, since the spill pressure is generated on the downstream side of the throttle member 111, the spill pressure is blocked by the convex portion 111c, and the hose 6 rubs against the clip 60 that fixes the throttle member 111 due to expansion, expansion, contraction, and vibration of the hose 6. No cracks can be prevented.

  In the present embodiment, the ring-shaped convex portion provided on the outer peripheral portion of the aperture member is formed in a substantially triangular shape in cross section passing through the axis, but the present invention is not limited to this. In other words, it may be formed in a substantially semicircular shape when viewed in cross section, or any shape that can prevent the movement of the diaphragm member.

  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 FIGS.

  As shown in FIG. 7, a suction pipe 120 is connected to a fuel supply port 36 that is a fuel inlet of the fuel injection pump 7 for supplying fuel from the fuel tank 1 to the fuel injection pump 7, and a predetermined distance from the fuel supply port 36. In the suction pipe 120 in which the throttle member 121 is arranged at a distant position, the throttle hole 121c formed in the axial center portion of the throttle member 121 has a large cross-sectional area on the end 121b side that is the fuel inlet side and the end on the other side. The sectional area gradually decreases toward the portion 121a. The suction pipe 120 of the fuel injection pump 7 includes a suction portion 31, a hose 6, a throttle member 121, a clip 60, and a three-way joint 5.

The upstream end of the suction part 31 is inserted into the downstream end of the hose 6, and the hose 6 is locked by a clip 60 so as not to fall off. The fuel supply port 36 and the hose 6 are communicated with each other by the suction passage 32 of the suction portion 31.
The throttle member 121 is inserted into the hose 6 at a predetermined distance from the fuel supply port 36 with the end 121a facing upstream and the end 121b facing downstream. The throttle member 121 has its midway portion secured from the outer periphery of the hose 6 by a clip 60.
The end portion 5 b of the three-way joint 5 is inserted into the upstream end portion of the hose 6 and is locked by a clip 60. 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 60 and 60, 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

  As shown in FIGS. 8A and 8B, the throttle hole 121c formed in the axial center portion of the throttle member 121 has a large cross-sectional area on the downstream end 121b side, and is on the upstream end 121a side. The cross-sectional area is gradually reduced toward.

  By configuring as in the present embodiment, bubbles generated by the spill pressure and air contained in the fuel can be easily discharged to the upstream side of the throttle member 121. Further, since the cross-sectional area of the throttle hole 121c is small on the upstream side of the throttle member 121, the bubbles discharged to the upstream side of the throttle member 121 are difficult to return to the downstream side again, and the engine malfunction can be prevented.

Further, the suction pipe 130 can be configured as shown in FIG. 9 by using the throttle member 131 configured as shown in FIGS. 8C and 8D.
That is, as shown in FIGS. 8C and 8D, a pair of upper and lower throttle holes formed in the shaft center portion of the throttle member 131 is provided, and the upper throttle hole 131c is an end on the downstream side (fuel inlet side). The section 131b side has a large cross-sectional area, the upstream end 131a side is small, and the lower throttle hole 131d has a small cross-sectional area on the end 131b side and the end 131a side is large. In this embodiment, it is configured to be vertically symmetrical, but it is also possible to configure a lower passage area than the upper side. In this case, the fuel is supplied more easily than described above. On the contrary, when the upper passage area is increased, air can be easily removed.
As shown in FIG. 9, the end portion 131 a of the throttle member 131 is directed upstream and the end portion 131 b is directed downstream, and is secured by a clip 60 within the hose 6 at a predetermined distance from the fuel supply port 36. To do. Further, the diaphragm member 131 is arranged such that the diaphragm hole 131c of the diaphragm member 131 is positioned above and the diaphragm hole 131d of the diaphragm member 131 is positioned below.

  With this configuration, bubbles generated by the spill pressure and air contained in the fuel can be easily discharged to the upstream side of the throttle member 131 through the upper throttle hole 131c. That is, since air in the fuel accumulates upward, most of the air is discharged through the upper throttle hole 131c. Further, it is difficult for the bubbles discharged to the upstream side of the throttle member 131 to return to the downstream side again, and it is possible to prevent engine malfunction. Since the fuel flows from the upstream side to the downstream side of the throttle member 131 through the lower throttle hole 131d, the fuel is smoothly supplied to the fuel injection pump 7.

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

  As shown in FIG. 10, in the suction pipe 140 connected to the fuel supply port 36 for supplying fuel from the fuel tank 1 to the fuel injection pump 7, a throttle member is integrally provided in the suction portion 141 of the suction pipe 140, The hose 6 constituting the suction pipe 140 is connected to the suction part 141 constituting the throttle member. The suction pipe 140 of the fuel injection pump 7 includes a suction part 141, a clip 60, a hose 6 and the like.

  The suction part 141 is composed of steel pipes 142 and 144. One end of the suction passage provided in the steel pipe 142 is connected to the plunger barrel 35, and one end of the steel pipe 144 is connected to the other end. The other end side (anti-steel pipe 142 side) of the steel pipe 144 is inserted into the hose 6, and the hose 6 is locked by a clip 60 so as not to fall off. In the middle of the steel pipe 142, a drawing portion 142a is provided by drawing at a position away from the fuel supply port 36 by a predetermined distance. That is, the throttle member is integrally provided in the suction portion 141. With this configuration, the fuel supply port 36 that is a fuel inlet and the hose 6 are communicated with each other. The steel pipe 142 is provided with a processing hole 142b for drilling the throttle portion 142a with a drill or the like. In order to prevent fuel leakage, a plug 143 is screwed into the processing hole 142b.

  By providing the throttle part 142a in the steel pipe 142, air bubbles generated when spill pressure is generated are discharged to the upstream side (steel pipe 144 side) from the throttle part 142a, and air and bubbles in the fuel upstream from the throttle part 142a are fueled. Inflow into the injection pump 7 is prevented.

  In such a configuration, the fuel stored in the fuel tank 1 passes through the hose 6, the steel pipe 144 of the suction part 141, and the throttle part 142 a of the steel pipe 142, flows into the fuel injection pump 7, and is pressurized by the fuel injection pump 7. It is pumped to the fuel injection nozzle 9 through the pipe 8.

  By configuring as in the present embodiment, the throttle portion 142a is configured integrally with the steel pipe 142, so that assembly is facilitated. Moreover, since the downstream side of the throttle part 142a that becomes high pressure due to the spill pressure can be formed of a steel pipe, the hose is not cracked. Furthermore, since the throttle portion 142a is configured integrally with the steel pipe 142, durability can be improved. That is, the predetermined distance between the fuel supply port 36 and the throttle portion 142a can be shortened. Thereby, since it is not necessary to provide a throttle member or the like in the hose 6, the hose 6 can be bent or shortened, and the suction pipe 140 can be configured compactly.

Also, the suction pipe 150 can be configured as shown in FIG.
That is, as shown in FIG. 11, another throttle member 151 is disposed in the suction pipe 150 that is a predetermined distance away from the suction portion 141 that is integrally provided with the throttle member.
Within the hose 6, the throttle member 151 is locked by the clip 60 at a position away from the throttle part 142 a provided in the suction part 141 by a predetermined distance. The “predetermined distance” from the throttle portion 142a to the throttle member 151 is the pressure between the throttle portion 142a and the throttle member 151 when spill pressure is generated, and the bubbles contained in the fuel are sufficiently upstream of the throttle member 151. This is the distance required to increase the pressure that can be discharged. This “predetermined distance” is a distance obtained by experiments or the like.
The end portion 5 b of the three-way joint 5 is inserted into the upstream end portion of the hose 6 and is locked by a clip 60. 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 60 and 60, respectively.

  Thus, by adding the throttle member 151 to the upstream side of the throttle portion 142a, the pressure on the downstream side of the throttle member 151 when the spill pressure is generated can be increased, and the bubbles can be sufficiently discharged. As a result, even when a large amount of air is present in the intake pipe 150 after the absence of fuel, the engine can be easily restarted after refueling.

In the present embodiment, the suction portion 141 is constituted by two members, steel pipes 142 and 144, but the present invention is not limited to this. For example, the suction part 141 may be constituted by a single member provided with the throttle part 142a.
In the present embodiment, the throttle portion 142a is provided in the middle of the steel pipe 142, but the present invention is not limited to this. That is, if it is a position where air bubbles can be discharged, the throttle part can be disposed at a desired position of the suction part 141 made of a steel pipe.
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 the branching position is further upstream depending on the type of joint. It can also be arranged on the side.

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. (A) Front view of throttle member constituting suction pipe according to one embodiment of the present invention, (b) Side sectional view of throttle member constituting suction pipe according to one embodiment of the present invention, (c) The front view of the throttle member which comprises the suction piping which is one Embodiment of this invention, (d) Side surface sectional drawing of the throttle member which comprises the suction piping which is one Embodiment of this 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. (A) Front view of throttle member constituting suction pipe according to one embodiment of the present invention, (b) Side sectional view of throttle member constituting suction pipe according to one embodiment of the present invention, (c) The front view of the throttle member which comprises the suction piping which is one Embodiment of this invention, (d) Side surface sectional drawing of the throttle member which comprises the suction piping which is one Embodiment of this 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 31 Suction Port 35 Plunger Barrel 36 Fuel Supply Port 60 Clip 110 Suction Pipe 111 Throttle Member

Claims (7)

In a suction pipe in which a suction pipe is connected to a fuel inlet of a fuel injection pump for supplying fuel from a fuel tank to a fuel injection pump, and a throttle member is arranged at a predetermined distance from the fuel inlet.
The suction pipe is constituted by a hose, a throttle member is inserted into the hose, the throttle member is substantially cylindrical, and ring-shaped convex portions are formed at outer peripheral portions at both axial ends. The fuel injection pump suction pipe. In a suction pipe in which a suction pipe is connected to a fuel inlet of a fuel injection pump for supplying fuel from a fuel tank to a fuel injection pump, and a throttle member is arranged at a predetermined distance from the fuel inlet.
The suction pipe is constituted by a hose, a throttle member is inserted into the hose, the throttle member is substantially cylindrical, and a ring-shaped convex portion is formed on the outer peripheral portion of the fuel inlet side end. The intake pipe of the fuel injection pump. The intake pipe of the fuel injection pump according to claim 1, wherein the convex portion is configured to have a substantially triangular shape in cross section. In a suction pipe in which a suction pipe is connected to a fuel inlet of a fuel injection pump for supplying fuel from a fuel tank to a fuel injection pump, and a throttle member is arranged at a predetermined distance from the fuel inlet.
An intake pipe of a fuel injection pump, characterized in that the throttle hole formed in the axial center portion of the throttle member has a configuration in which the cross-sectional area on the fuel inlet side is large and the cross-sectional area gradually decreases toward the other side. In a suction pipe in which a suction pipe is connected to a fuel inlet of a fuel injection pump for supplying fuel from a fuel tank to a fuel injection pump, and a throttle member is arranged at a predetermined distance from the fuel inlet.
A pair of upper and lower throttle holes formed in the axial center of the throttle member is provided, the upper throttle hole has a large cross-sectional area on the fuel inlet side, the other side is small, and the lower throttle hole has a small cross-sectional area on the fuel inlet side. The intake pipe of the fuel injection pump is characterized in that the other side becomes larger. 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 throttle member is integrally provided at a suction portion of the suction pipe, and the suction pipe is connected to the throttle member. The suction pipe of the fuel injection pump according to claim 6, wherein another throttle member is disposed in the suction pipe that is separated from the throttle member by a predetermined distance.

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