JP2017031918A - Fuel injection pump, fuel injection device, and internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection pump, a fuel injection device and an internal combustion engine, which can be small-sized.SOLUTION: A fuel injection pump comprises: a pump case 21; a plunger barrel 22 arranged in the pump case 21; a plunger 23 supported movably along an axial direction in the plunger barrel 22; a suction valve 24 partitioning a fuel compression chamber 67 by the plunger barrel 22 and the plunger 23 and capable of sucking the fuel from the outside into the fuel compression chamber 67; and a discharge valve 25 capable of discharging the fuel of the fuel compression chamber 67 to the outside. The plunger barrel 22, the suction valve 24 and the discharge valve 25 are arranged in series along the longitudinal direction in the pump case 21, and the outer wall surface is supported by the inner wall surface of the pump case 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel injection pump used in an internal combustion engine mounted on a ship, a fuel injection device to which the fuel injection pump is applied, and an internal combustion engine to which the fuel injection device is applied.

  For example, as a fuel injection device of a diesel engine applied to an internal combustion engine mounted on a ship, there are those described in the following patent documents. The fuel injection device described in Patent Documents 1 and 2 controls a fuel injection valve that injects fuel into a combustion chamber, a fuel injection pump that is provided with a plunger that pumps fuel to the fuel injection valve, and an operation of the plunger. And a pressure accumulation control valve block. The fuel injection pump includes a pump case, a plunger barrel, a plunger, a suction valve, and a discharge valve.

JP 2003-328897 A JP 2013-139737 A

  In the conventional fuel injection pump described above, a plunger barrel is mounted inside the pump case, and the plunger is supported inside the plunger barrel so as to be movable in the axial direction. An intake valve and a discharge valve are arranged in the front. That is, the pump case, the plunger barrel, the suction valve, and the discharge valve have a triple structure in the radial direction. Therefore, there exists a problem that the outer diameter of a fuel injection pump will enlarge.

  The present invention solves the above-described problems, and an object thereof is to provide a fuel injection pump, a fuel injection device, and an internal combustion engine that can be reduced in size.

  In order to achieve the above object, a fuel injection pump according to the present invention includes a pump case, a plunger barrel disposed in the pump case, and a plunger supported in the plunger barrel so as to be movable along the axial direction. And a suction valve that partitions the fuel compression chamber by the plunger barrel and the plunger and can suck fuel from the outside into the fuel compression chamber, and the plunger barrel and the suction valve are disposed in the pump case. Are arranged linearly along the longitudinal direction, and the outer wall surface is supported by the inner wall surface of the pump case.

  Therefore, the plunger barrel and the suction valve are linearly arranged in the pump case and the outer wall surface is supported by the pump case, so that the pump case can be reduced in diameter, and the entire fuel injection pump can be reduced in size and reduced in size. Can be

  In the fuel injection pump of the present invention, the plunger is urged and supported by a return spring in a first direction away from the fuel compression chamber, and the return spring is a compression disposed between the pump case and the plunger. The coil spring is characterized in that one end thereof is elastically pressed against a spring receiving portion in the pump case, and the other end is elastically pressed against a spring receiving member of the plunger.

  Therefore, by interposing a return spring that biases and supports the plunger in the first direction between the spring receiving portion of the pump case and the spring receiving member of the plunger, the plunger to the pump case, the return spring, the plunger barrel, etc. Assembling property can be improved.

  The fuel injection pump according to the present invention further includes a discharge valve capable of discharging the fuel in the fuel compression chamber to the outside, and the plunger barrel is moved in the first direction by a stopper provided on an inner wall surface of the pump case. And the suction valve and the discharge valve are compressed and held by the presser member in a state where the suction valve and the discharge valve are arranged in close contact with each other in a straight line.

  Therefore, by compressing and holding the plunger barrel, the suction valve, and the discharge valve in the pump case, tensile stress does not act on the plunger barrel and the like, and the fatigue strength can be improved.

  In the fuel injection pump of the present invention, the plunger barrel, the suction valve, and the discharge valve are set to have the same maximum outer diameter.

  Therefore, since the maximum outer diameters of the plunger barrel, the suction valve, and the discharge valve are the same, the machining of the inner diameter of the pump case can be simplified and the machining cost can be reduced. The discharge valve can be easily inserted and fixed, and the assemblability can be improved.

  In the fuel injection pump of the present invention, the intake valve is provided with a small diameter portion whose outer diameter is smaller than the inner diameter of the pump case, so that a fuel supply / discharge chamber is formed between the small diameter portion and the pump case, The fuel supply / discharge chamber is communicated with the fuel compression chamber via a fuel intake passage.

  Therefore, by providing the intake valve with a small-diameter portion to form the fuel supply / discharge chamber, it is possible to reduce the processing cost by eliminating the need to process the recess on the inner wall surface of the pump case, and to reduce the thickness of the pump case. Therefore, the fuel injection pump as a whole can be further reduced in size and reduced in size.

A fuel injection device of the present invention includes a fuel injection valve that injects fuel into a combustion chamber of an internal combustion engine,
The fuel injection pump for supplying fuel to the fuel injection valve, and an accumulator control device for controlling the operation of the plunger in the fuel injection pump.

  Therefore, the fuel injection device can be reduced in size and weight by reducing the size of the entire fuel injection pump to a small diameter.

  Moreover, the internal combustion engine of the present invention includes the fuel injection device.

  Therefore, the internal combustion engine can be reduced in size and weight by downsizing the entire fuel injection pump to have a small diameter.

  According to the fuel injection pump, the fuel injection device, and the internal combustion engine of the present invention, the entire fuel injection pump can be reduced in size with a small diameter.

FIG. 1 is a schematic cross-sectional view showing a fuel injection pump according to this embodiment. FIG. 2 is a cross-sectional view showing the main part of the fuel injection pump of this embodiment. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a schematic configuration diagram showing the fuel injection device of the present embodiment.

  Exemplary embodiments of a fuel injection pump, a fuel injection device, and an internal combustion engine according to the present invention will be explained below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

  FIG. 4 is a schematic configuration diagram showing the fuel injection device of the present embodiment.

  In the present embodiment, as shown in FIG. 4, the fuel injection device 10 is mounted on a large marine diesel engine (internal combustion engine) mounted on a marine vessel. The fuel injection device 10 includes a fuel injection valve 11, a fuel injection pump 12, and a pressure accumulation control valve block 13.

  The fuel injection valve 11 injects fuel into a combustion chamber of a diesel engine (not shown). The fuel injection pump 12 pumps fuel to the fuel injection valve 11 and is connected via a fuel pipe 14. The pressure accumulation control valve block 13 controls the fuel injection pump 12. The pressure control valve block 13 is installed on the side of the cylinder block of the diesel engine and the like, and the fuel injection pump 12 configured in a tower shape is disposed above the pressure accumulation control valve block 13. It is erected.

  Hereinafter, the fuel injection pump 12 of this embodiment will be described in detail. 1 is a schematic cross-sectional view showing a fuel injection pump according to the present embodiment, FIG. 2 is a cross-sectional view showing a main part of the fuel injection pump according to the present embodiment, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. .

  As shown in FIGS. 1 to 3, the fuel injection pump 12 of this embodiment includes a pump case 21, a plunger barrel 22, a plunger 23, a suction valve 24, and a discharge valve 25. The plunger barrel 22, the intake valve 24, and the discharge valve 25 are arranged in series so as to form a straight line along the longitudinal direction in the pump case 21, and the outer wall surface is supported by the inner wall surface of the pump case 21. Has been.

  The pump case 21 includes a case body 31 having a cylindrical shape, a case mounting base 32 having a cylindrical shape, and a pressing member 33 having a columnar shape. The case body 31 is provided with a first housing part 34 that houses most of the plunger barrel 22, the suction valve 24, the discharge valve 25, and the like, and a second housing part 35 that houses the plunger 23 and the like. The first housing portion 34 and the second housing portion 35 are configured by a continuous space portion, the first housing portion 34 is located above the second housing portion 35, and is accommodated in a second space from the inner diameter dimension of the first housing portion 34. The inner diameter dimension of the part 35 is set large.

  The case mounting base 32 is connected by a connecting bolt (not shown) with the outer peripheral surface of the upper end fitted into the inner peripheral surface of the lower end (second accommodating portion 35) of the case main body 31. The case mounting base 32 is formed with a support hole 36 that supports the plunger 23 movably along the axial direction at the center in the radial direction. And the lower end part of this case mounting base 32 is being fixed to the upper surface part of the pressure accumulation control valve block 13 (refer FIG. 4).

  The outer circumferential surface of the lower end portion of the presser member 33 is fitted and fixed to the inner circumferential surface of the upper end portion (first housing portion 34) of the case main body 31. The holding member 33 has an outer diameter that is the same as the outer diameter of the case main body 31, and a fitting portion 37 that is fitted to the upper end portion of the first housing portion 34 in the case main body 31 and presses the discharge valve 25 is provided. In addition, a plurality of mounting holes 38 along the axial direction are formed on the outer peripheral surface side at predetermined intervals in the circumferential direction. In the holding member 33, the plurality of fastening bolts 39 penetrate the mounting holes 38 in a state where the fitting portion 37 is fitted into the first housing portion 34 of the case main body 31 and is in close contact with the upper end surface of the case main body 31. The case body 31 is fixed to the case body 31 by being screwed into the screw hole 40 formed in the case body 31.

  The plunger barrel 22 is disposed in the case body 31 in the pump case 21. The plunger barrel 22 includes an upper-side large-diameter portion 41 and a lower-side small-diameter portion 42, and an outer peripheral surface of the large-diameter portion 41 and an outer peripheral surface of the small-diameter portion 42 between the large-diameter portion 41 and the small-diameter portion 42. And an inclined surface 43 is formed. On the other hand, the pump case 21 is provided with a protruding portion (stopper) 44 that protrudes toward the central portion in the radial direction on the inner peripheral surface of the first housing portion 34. The protruding portion 44 has a ring shape, and an inclined surface 45 is formed on the upper portion. The inclined surface 45 of the protruding portion 44 is set at the same angle as the inclined surface 43 of the plunger barrel 22. In addition, the plunger barrel 22 is formed with a support hole 46 that supports the plunger 23 movably along the axial direction at the center in the radial direction.

  Therefore, the plunger barrel 22 is disposed in the pump case 21 and is positioned by the inclined surface 43 abutting on the inclined surface 45 of the projecting portion 44, and then moves in the first direction (downward in the axial direction) A. Is restrained.

  The plunger 23 is provided with an upper-side small-diameter portion 47 and a lower-side large-diameter portion 48, and the upper surface of the small-diameter portion 47 serves as a pressure surface 49 and the lower surface of the large-diameter portion 48 serves as a pressure-receiving surface 50. The plunger 23 is disposed in the case body 31 of the pump case 21, the small diameter portion 47 is supported in the support hole 46 of the plunger barrel 22 so as to be movable along the axial direction, and the large diameter portion 48 is attached to the case. A support hole 36 of the base 32 is supported so as to be movable along the axial direction.

  The plunger 23 is urged and supported in the first direction A by the urging force of the return spring 51. The return spring 51 is a compression coil spring, and is disposed between the plunger 23 and the case body 31. In the plunger 23, a spring receiving member 52 is fixed to the step portion of the small diameter portion 47 and the large diameter portion 48. On the other hand, the case main body 31 has a spring receiving portion 53 formed at a step portion between the inner wall surface of the first housing portion 34 and the inner wall surface of the second housing portion 35. The return spring 51 urges the plunger 23 in the first direction A by having the lower end elastically pressed against the spring receiving member 52 and the upper end pressed against the spring receiving portion 53. The plunger 23 can be moved in a second direction B (upward in the axial direction) opposite to the first direction A by the pressure accumulation control valve block 13 (see FIG. 4).

  The suction valve 24 includes a suction valve main body 61, a valve body 62, and a compression spring 63. The intake valve main body 61 is provided with an upper-side small-diameter portion 64 and a lower-side large-diameter portion 65, and a fuel passage 66 is formed along the axial direction at the center in the radial direction. The suction valve 24 is located at the center in the radial direction by the suction valve 24, the plunger barrel 22, and the plunger 23, with the lower surface of the suction valve body 61 being in close contact with the upper surface of the plunger barrel 22. Has been. A fuel supply / discharge chamber 68 is defined between the small diameter portion 64 of the intake valve main body 61 in the intake valve 24 and the case main body 31 in the pump case 21. The fuel supply / discharge chamber 68 is a ring-shaped space, and communicates with the fuel compression chamber 67 through a plurality of fuel intake passages 69 that penetrate the intake valve body 61 in the radial direction. The pump case 21 is formed with a fuel supply path 70 and a fuel discharge path 71 that penetrate the case body 31 in the radial direction at predetermined intervals in the circumferential direction. The fuel supply path 70 and the fuel discharge path 71 are One end portion communicates with the fuel supply / discharge chamber 68 and the other end portion is connected to a fuel supply device (not shown).

  The intake valve 24 can suck the fuel supplied from the outside into the fuel supply / discharge chamber 68 through the fuel supply passage 70 through the fuel intake passage 69 into the fuel compression chamber 67. That is, the valve element 62 is disposed in the fuel passage 66 in the intake valve main body 61, is movable in the axial direction, and is pressed against the intake valve seat by the urging force of the compression spring 63, so that the fuel intake passage 69 and the fuel compression are compressed. The communication of the chamber 67 is blocked. Therefore, when the pressure of the fuel supplied from the fuel supply passage 70 to the fuel supply / discharge chamber 68 by the fuel supply device and acting on the valve body 62 from the fuel intake passage 69 increases, the valve body 62 resists the urging force of the compression spring 63. As a result, the fuel intake passage 69 and the fuel compression chamber 67 communicate with each other. Then, the fuel in the fuel supply / discharge chamber 68 is sucked into the fuel compression chamber 67 through the fuel suction passage 69.

  The discharge valve 25 includes a suction valve main body 81, a valve body 82, and a compression spring 83. The intake valve body 81 has a fuel passage 84 formed along the axial direction at the center in the radial direction. The lower surface of the intake valve main body 81 is in close contact with the upper surface of the intake valve 24 so that the fuel passages 66 and 84 communicate with each other in series. doing. The discharge valve 25 can discharge the fuel supplied to the fuel compression chamber 67 to the outside. That is, the valve body 82 is disposed in the fuel passage 84 in the discharge valve main body 81 and is movable in the axial direction, and is pressed against the discharge valve seat by the urging force of the compression spring 83, so that the fuel passage 66 and the fuel passage 84 are pressed. The communication of is blocked.

  In addition, the pressing member 33 is provided with a fuel discharge passage 85 at the center in the radial direction and a spring accommodating portion 86 around the fuel discharge passage 85. The fuel discharge passage 85 has one end communicating with the fuel passage 84 and a connection plug 87 connected to the other end. The spring accommodating portion 86 opens to the discharge valve 25 side, and the compression spring 83 is accommodated therein.

  Therefore, when the plunger 23 moves in the second direction B and the fuel pressure in the fuel compression chamber 67 rises, the fuel pressure in the fuel compression chamber 67 acts on the valve body 82 through the fuel passage 66. When the fuel pressure in the fuel compression chamber 67 is further increased, the valve body 82 rises against the urging force of the compression spring 83 and leaves the discharge valve seat, so that the fuel passage 66 and the fuel passage 84 communicate with each other. Then, the fuel in the fuel compression chamber 67 flows into the fuel passage 84 through the fuel passage 66 and is discharged to the outside through the fuel discharge passage 85.

  The plunger barrel 22, the suction valve 24, and the discharge valve 25 are arranged in series in the case main body 31 and are compressed and held by the pressing member 33 in a state of being in close contact with each other. That is, the plunger barrel 22, the intake valve 24, and the discharge valve 25 can be easily inserted from the upper part of the case body 31 because the maximum outer diameter is set to the same size according to the inner diameter of the case body 31. Then, the plunger barrel 22 is restrained from moving in the first direction A because the inclined surface 43 comes into contact with the inclined surface 45 of the protruding portion 44 in the case body 31. The intake valve 24 is positioned in contact with the upper surface of the plunger barrel 23 in the case body 31, and the discharge valve 25 is positioned in contact with the upper surface of the intake valve 24 in the case body 31. At this time, the plunger barrel 22, the suction valve 24, and the discharge valve 25 are positioned in the radial direction by the outer peripheral surfaces being supported by the inner peripheral surface of the case body 31. The pressing member 33 is fixed to the case main body 31 by a plurality of fastening bolts 39 while the fitting portion 37 is fitted to the case main body 31 and the upper surface of the discharge valve 25 is pressed.

  Here, the operation of the fuel injection pump 12 and the fuel injection device 10 will be described.

  As shown in FIGS. 1 and 4, in the fuel injection pump 12, fuel of a predetermined pressure is supplied from the fuel supply passage 70 to the valve body 62 of the intake valve 24 through the fuel supply / discharge chamber 68 and the fuel intake passage 69 by the fuel supply device. Then, the valve body 62 moves against the urging force of the compression spring 63 so that the fuel suction passage 69 and the fuel compression chamber 67 communicate with each other, so that the fuel in the fuel supply / discharge chamber 68 flows from the fuel suction passage 69. The fuel is sucked into the fuel compression chamber 67. In this state, when the pressure in the fuel compression chamber 67 is increased by moving the plunger 23 in the second direction B by the pressure accumulation control valve block 13 and the fuel pressure exceeds a predetermined pressure, the valve body 82 of the discharge valve 25 is moved. Since the fuel passage 66 and the fuel passage 84 communicate with each other by moving against the urging force of the compression spring 83, the fuel in the fuel compression chamber 67 flows to the fuel passage 84 through the fuel passage 66 and passes through the fuel discharge passage 85 to the outside. Discharged. Then, the fuel injection valve 11 can inject fuel into the combustion chamber of the diesel engine.

  Thus, in the fuel injection pump of the present embodiment, the pump case 21, the plunger barrel 22 disposed in the pump case 21, and the plunger barrel 22 are supported so as to be movable along the axial direction. The plunger 23, the plunger barrel 22 and the plunger 23 define the fuel compression chamber 67, and the intake valve 24 capable of sucking fuel from the outside into the fuel compression chamber 67, and the fuel in the fuel compression chamber 67 can be discharged to the outside. A discharge valve 25 is provided, and the plunger barrel 22, the suction valve 24, and the discharge valve 25 are arranged in series along the longitudinal direction in the pump case 21 and the outer wall surface is supported on the inner wall surface of the pump case 21.

  Therefore, the plunger barrel 22, the suction valve 24, and the discharge valve 25 are arranged in series in the pump case 21 and the outer wall surface is supported by the pump case 21, so that the suction valve 24 and the discharge valve 25 are conventionally provided. Need not be supported by the plunger barrel 22, the plunger barrel 22 can be reduced in size, and the pump case 21 can be reduced in diameter. As a result, the entire fuel injection pump 10 can be reduced in size with a small diameter.

  In the fuel injection pump of this embodiment, the return spring 51 urges and supports the plunger 23 in the first direction A away from the fuel compression chamber 67, the return spring 51 is a compression coil spring, and one end is a case of the pump case 21. The spring receiving portion 53 of the main body 31 is elastically pressed and the other end is elastically pressed to the spring receiving member 52 of the plunger 23. Therefore, the plunger 23 and the return spring 51 can be easily assembled to the pump case 21, and the assembling property of the plunger barrel 22, the plunger 23, the return spring 51 and the like to the pump case 21 can be improved. Further, since the spring receiving portion 53 is provided in the case main body 31, no fastening means such as a bolt for fixing the plunger barrel 22 to the case main body 31 is required, so that the fuel injection pump 10 as a whole is reduced in size and reduced in size. can do.

  In the fuel injection pump of the present embodiment, the plunger barrel 22 is restrained from moving in the first direction A by the protruding portion 44 provided on the inner wall surface of the pump case 21, and the suction valve 24 and the discharge valve 25 are in close contact with each other in a straight line. In this state, it is compressed and held by the presser member 33. Therefore, the plunger barrel 22, the suction valve 24, and the discharge valve 25 are compressed and held in the pump case 21, so that tensile stress does not act on the plunger barrel 22 and the like, and the fatigue strength can be improved.

  In the fuel injection pump of this embodiment, the maximum outer diameter dimensions of the plunger barrel 22, the suction valve 24, and the discharge valve 25 are set to the same dimension. Accordingly, the plunger barrel 22, the suction valve 24, and the discharge valve 25 can be easily inserted into the pump case 21, and the inner diameter of the inner wall surface of the pump case 21 that supports the plunger barrel 22, the suction valve 24, and the discharge valve 25. The dimensions can be set to the same dimension, the inner diameter machining of the pump case 21 can be simplified and the machining cost can be reduced, and the plunger barrel 22, the suction valve 24 and the discharge valve 25 can be easily provided in the pump case 21. It can fix and can improve assembly property.

  In the fuel injection pump of the present embodiment, a fuel supply / discharge chamber 68 is formed between the small diameter portion 64 and the pump case 21 by providing a small diameter portion where the outer diameter of the suction valve 24 is smaller than the inner diameter of the pump case 21. The fuel supply / discharge chamber 68 communicates with the fuel compression chamber 67 through the fuel intake passage 69. Accordingly, by providing the intake valve 24 with the small-diameter portion 64 to form the fuel supply / discharge chamber 68, it is possible to reduce the processing cost by eliminating the need for processing the recess on the inner wall surface of the pump case 21. The wall thickness can be reduced, and the fuel injection pump 12 as a whole can be further reduced in size and reduced in size.

  Further, in the fuel injection device of the present embodiment, the fuel injection valve 11 that injects fuel into the combustion chamber of the diesel engine, the fuel injection pump 12 that supplies fuel to the fuel injection valve 11, and the fuel injection pump 12 And a pressure accumulation control valve block 13 for controlling the operation of the plunger 23. Therefore, the fuel injection device 10 can be reduced in size and weight by reducing the size of the entire fuel injection pump 12 to a small diameter.

  In addition, since the internal combustion engine of the present embodiment includes the fuel injection device 10, it is possible to reduce the size of the fuel injection pump 12 as a whole and to reduce the size and weight of the diesel engine.

DESCRIPTION OF SYMBOLS 10 Fuel-injection apparatus 11 Fuel-injection valve 12 Fuel-injection pump 13 Accumulation-control valve 21 Pump case 22 Plunger barrel 23 Plunger 24 Suction valve 25 Discharge valve 31 Case main body 32 Case mount 33 Holding member 43, 45 Inclined surface 44 Projection part 51 Return spring 52 Spring receiving member 53 Spring receiving portion 61 Suction valve main body 62 Valve body 63 Compression spring 66 Fuel passage 67 Fuel compression chamber 68 Fuel supply / discharge chamber 69 Fuel intake passage 70 Fuel supply passage 71 Fuel discharge passage 81 Suction valve main body 82 Valve Body 83 Compression spring 84 Fuel passage 85 Fuel discharge passage

The fuel injection device of the present invention, a fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine, said fuel injection pump for supplying fuel to the fuel injection valve, the actuation of the plunger in the fuel injection pump And an accumulator control device for controlling.

The discharge valve 25 includes a discharge valve main body 81 , a valve body 82, and a compression spring 83. In the discharge valve main body 81 , a fuel passage 84 is formed along the axial direction at the center in the radial direction, and the fuel passages 66 and 84 communicate with each other in series by having the lower surface in close contact with the upper surface of the intake valve 24. doing. The discharge valve 25 can discharge the fuel supplied to the fuel compression chamber 67 to the outside. That is, the valve body 82 is disposed in the fuel passage 84 in the discharge valve main body 81 and is movable in the axial direction, and is pressed against the discharge valve seat by the urging force of the compression spring 83, so that the fuel passage 66 and the fuel passage 84 are pressed. The communication of is blocked.

The plunger barrel 22, the suction valve 24, and the discharge valve 25 are arranged in series in the case main body 31 and are compressed and held by the pressing member 33 in a state of being in close contact with each other. That is, the plunger barrel 22, the intake valve 24, and the discharge valve 25 can be easily inserted from the upper part of the case body 31 because the maximum outer diameter is set to the same size according to the inner diameter of the case body 31. Then, the plunger barrel 22 is restrained from moving in the first direction A because the inclined surface 43 comes into contact with the inclined surface 45 of the protruding portion 44 in the case body 31. The suction valve 24 is positioned in contact with the upper surface of the plunger barrel 22 in the case body 31, and the discharge valve 25 is positioned in contact with the upper surface of the suction valve 24 in the case body 31. At this time, the plunger barrel 22, the suction valve 24, and the discharge valve 25 are positioned in the radial direction by the outer peripheral surfaces being supported by the inner peripheral surface of the case body 31. The pressing member 33 is fixed to the case main body 31 by a plurality of fastening bolts 39 while the fitting portion 37 is fitted to the case main body 31 and the upper surface of the discharge valve 25 is pressed.

Therefore, the plunger barrel 22, the suction valve 24, and the discharge valve 25 are arranged in series in the pump case 21 and the outer wall surface is supported by the pump case 21, so that the suction valve 24 and the discharge valve 25 are conventionally provided. Need not be supported by the plunger barrel 22, the plunger barrel 22 can be reduced in size, and the pump case 21 can be reduced in diameter. As a result, the entire fuel injection pump 12 can be reduced in size with a small diameter.

In the fuel injection pump of this embodiment, the return spring 51 urges and supports the plunger 23 in the first direction A away from the fuel compression chamber 67, the return spring 51 is a compression coil spring, and one end is a case of the pump case 21. The spring receiving portion 53 of the main body 31 is elastically pressed and the other end is elastically pressed to the spring receiving member 52 of the plunger 23. Therefore, the plunger 23 and the return spring 51 can be easily assembled to the pump case 21, and the assembling property of the plunger barrel 22, the plunger 23, the return spring 51 and the like to the pump case 21 can be improved. Further, since the spring receiving portion 53 is provided in the case body 31, because the fastening means such as bolts for fixing the plunger barrel 22 to the case body 31 is not necessary, miniaturization of the entire fuel injection pump 12 as a small diameter can do.

DESCRIPTION OF SYMBOLS 10 Fuel-injection apparatus 11 Fuel-injection valve 12 Fuel-injection pump 13 Accumulation-control valve 21 Pump case 22 Plunger barrel 23 Plunger 24 Suction valve 25 Discharge valve 31 Case main body 32 Case mount 33 Holding member 43, 45 Inclined surface 44 Projection part 51 Return spring 52 Spring receiving member 53 Spring receiving portion 61 Suction valve body 62 Valve body 63 Compression spring 66 Fuel passage 67 Fuel compression chamber 68 Fuel supply / discharge chamber 69 Fuel intake passage 70 Fuel supply passage 71 Fuel discharge passage 81 Discharge valve main body 82 Valve Body 83 Compression spring 84 Fuel passage 85 Fuel discharge passage

Claims (7)

A pump case,
A plunger barrel disposed in the pump case;
A plunger supported movably along the axial direction in the plunger barrel;
A suction valve that divides a fuel compression chamber by the plunger barrel and the plunger and can suck fuel from the outside into the fuel compression chamber;
With
The plunger barrel and the suction valve are arranged linearly along the longitudinal direction in the pump case, and the outer wall surface is supported by the inner wall surface of the pump case.
A fuel injection pump characterized by that.   The plunger is urged and supported in a first direction away from the fuel compression chamber by a return spring, and the return spring is a compression coil spring disposed between the pump case and the plunger, and has one end portion. The fuel injection pump according to claim 1, wherein the spring receiving portion of the pump case is elastically pressed, and the other end portion is elastically pressed to the spring receiving member of the plunger.   A discharge valve capable of discharging the fuel in the fuel compression chamber to the outside; and the plunger barrel is restrained from moving in the first direction by a stopper provided on an inner wall surface of the pump case; 3. The fuel injection pump according to claim 2, wherein the discharge valve is compressed and held by a pressing member in a state where the discharge valve is arranged in close contact with a straight line.   The fuel injection pump according to claim 3, wherein the plunger barrel, the intake valve, and the discharge valve have the same maximum outer diameter.   The intake valve is provided with a small-diameter portion whose outer diameter is smaller than the inner diameter of the pump case, so that a fuel supply / discharge chamber is formed between the small-diameter portion and the pump case. The fuel injection pump according to any one of claims 1 to 4, wherein the fuel injection pump is communicated with the fuel compression chamber via a suction passage. A fuel injection valve for injecting fuel into the combustion chamber of the internal combustion engine;
The fuel injection pump according to any one of claims 1 to 5, wherein fuel is supplied to the fuel injection valve.
An accumulator control device for controlling the operation of the plunger in the fuel injection pump;
A fuel injection device comprising:   An internal combustion engine comprising the fuel injection device according to claim 6.

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