JP2016121627A - High pressure fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure fuel pump which prevents a plunger from being inclined by compression of a spring.SOLUTION: A high pressure fuel pump includes: a plunger 24 which is disposed so as to reciprocate relative to a cylinder; a compression chamber which is defined in the cylinder; a spring 33 which biases the plunger 24 in a direction such that the plunger 24 moves away from the compression chamber; and an annular plate 32 which is a member for transmitting a biasing force of the spring 33 to the plunger 24 and includes an inner peripheral portion 32a configured to engage with a groove 24d provided in the plunger 24. In the high pressure fuel pump, a protruding part 32b protruding to the wall surface 24e side is formed in the inner peripheral portion 32a of the plate 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a high-pressure fuel pump.

  Conventionally, a cam-driven high-pressure fuel pump is known as a high-pressure fuel pump provided in an engine that requires high fuel pressure, such as an in-cylinder injection type (for example, Patent Document 1). Such a high-pressure fuel pump is configured to perform suction and pressurization of fuel through reciprocation of a plunger by a cam.

  As shown in FIG. 11, the high-pressure fuel pump described in the literature 1 includes a cylindrical cylinder 51 provided in the pump body 50, a plunger 52 disposed in the cylinder 51 so as to be slidable back and forth, and a cylinder 51. And a cam 53 for reciprocating the plunger 52. The plunger 52 is installed in a state where one end is inserted into the cylinder 51 and the other end protrudes outside the cylinder 51, and a pressurizing chamber 57 is defined in the cylinder 51.

  On the other hand, a lifter 54 is interposed between the end surface 52 a of the other end of the plunger 52 and the cam 53. A groove 52b that goes around the outer periphery is formed on the other end side of the plunger 52, and an annular plate 58 is engaged with the groove 52b. A spring 56 is interposed between the plate 58 and the pump body 50 in a compressed state. Such a biasing force of the spring 56 is transmitted to the plunger 52 via the plate 58. The lifter 54 is pressed against the cam 53 by the end surface 52 a of the plunger 52 pressing the lifter 54 by the transmitted urging force.

JP 2009-209838 A

By the way, when the spring 56 is compressed, a force (lateral force) in a direction perpendicular to the expansion / contraction direction may be generated.
As shown in FIG. 12, when such a lateral force is generated, the spring 56 tends to fall, so that the plate 58 engaged with the groove 52b is inclined. When the plate 58 is inclined, the plate 58 comes into contact with the corner portion K on the contact surface side where the inner peripheral side portion of the plate 58 and the groove 52b come into contact with each other in the groove 52b by the biasing force of the spring 56. Therefore, the urging force F of the spring 56 acts intensively on the corner portion K, that is, the substantially same portion as the outer peripheral surface of the plunger 52, and a moment in the direction in which the axis of the plunger 52 is inclined is generated. As a result, the plunger 52 is inclined with respect to the cylinder 51. As a result, the sliding resistance of the plunger 52 with respect to the cylinder 51 increases, which may cause, for example, abnormal wear or seizure.

  The present invention has been made in view of such circumstances, and a problem to be solved is to provide a high-pressure fuel pump capable of suppressing the inclination of the plunger caused by the compression of the spring.

  A high-pressure fuel pump that solves the above-described problem is provided with a cylindrical cylinder and a reciprocating slide with respect to the cylinder with one end inserted into the cylinder and the other end protruding outside the cylinder. A rod-shaped plunger, a pressurizing chamber defined in the cylinder, a spring that biases the plunger in a direction away from the pressurizing chamber, and a member that transmits the biasing force of the spring to the plunger. An annular plate with which an inner peripheral side portion engages with an engaging portion provided on the end side is provided. In this high-pressure pump, the distance between the wall surface of the engaging portion where the inner peripheral portion of the plate contacts by the biasing force of the spring and the inner peripheral portion of the plate facing the wall surface is the center of the plunger. The part far from the axis is longer than the part close to the axis.

  According to this configuration, the inner peripheral portion of the annular plate and the wall surface of the engaging portion provided on the plunger are brought into contact with each other by the biasing force of the spring. The distance between the wall surface of the engaging portion that the inner peripheral part of this plate contacts and the inner peripheral part of the plate facing the same wall surface is farther than the part closer to the central axis of the plunger. Has been long. Therefore, when the plate is tilted by the lateral force generated by the compression of the spring, the plate is prevented from coming into contact with a portion far from the central axis of the plunger, for example, a portion near the outer peripheral surface of the plunger. It comes into contact with a portion near the central axis of the plunger at the joint. As described above, when the plate comes into contact with a portion near the central axis of the plunger in the engaging portion, the biasing force of the spring acts on the plunger as compared with the case where the plate comes into contact with a portion far from the central axis of the plunger. The distance between the point to be moved and the central axis of the plunger is shortened. Therefore, the moment generated by the urging force of the spring, that is, the moment in the direction in which the plunger shaft is inclined is reduced. Therefore, according to the same structure, the inclination of the plunger caused by the compression of the spring can be suppressed.

  Note that the distance between the wall surface of the engaging portion where the inner peripheral portion of the plate contacts with the biasing force of the spring and the inner peripheral portion of the plate facing this wall surface is set closer to the portion closer to the central axis of the plunger. In order to configure the far portion to be longer than that of the plate, it is preferable to form a convex portion protruding toward the wall surface on the inner peripheral portion of the plate.

  In addition, the distance between the wall surface of the engaging portion where the inner peripheral portion of the plate comes into contact with the urging force of the spring and the inner peripheral portion of the plate facing the wall surface is set to a portion closer to the central axis of the plunger. In order to configure the far portion to be longer in comparison, it is preferable to form the inner peripheral portion of the plate so that the thickness increases toward the wall surface as it approaches the central axis of the plunger. .

  In addition, the distance between the wall surface of the engaging portion where the inner peripheral portion of the plate comes into contact with the urging force of the spring and the inner peripheral portion of the plate facing the wall surface is set to a portion closer to the central axis of the plunger. In order to make the far part longer than the other part, the wall surface facing the inner peripheral part of the plate is formed in a tapered shape inclined so that the distance becomes shorter as it approaches the central axis of the plunger. It is preferable to do.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows typically the structure of the fuel system of the engine in which the high pressure fuel pump of 1st Embodiment was installed. Sectional drawing of the same high-pressure fuel pump along the moving direction of a plunger. The A section enlarged view of FIG. The expanded sectional view which shows the positional relationship of the groove | channel of a plunger when a plate inclines, and a plate. The expanded sectional view of the plate periphery with which the high-pressure fuel pump of 2nd Embodiment is provided. The expanded sectional view which shows the positional relationship of the groove | channel of a plunger when a plate of the embodiment inclines, and a plate. The expanded sectional view around the groove | channel of the plunger with which the high pressure fuel pump of 3rd Embodiment is provided. In the same embodiment, the expanded sectional view which shows the groove | channel of a plunger when a plate inclines, and the positional relationship of a plate. The expanded sectional view of the plate in the modification of 1st Embodiment. The expanded sectional view of the plunger in the modification of 1st Embodiment. Sectional drawing of the conventional fuel pump. The expanded sectional view of the groove | channel and plate which were formed in the plunger with which the fuel pump is provided.

(First embodiment)
Hereinafter, a first embodiment of a high-pressure fuel pump will be described in detail with reference to FIGS. The high-pressure fuel pump of the present embodiment is configured as a cam-driven high-pressure fuel pump, and is provided in an in-cylinder in-cylinder injection engine.

  As shown in FIG. 1, a feed pump 11 that pumps fuel is provided inside a fuel tank 10 of a direct injection engine. The feed pump 11 is connected to a high pressure fuel pump 13 through a low pressure fuel passage 12. The low-pressure fuel passage 12 is provided with a regulator 14 that discharges the internal fuel to the fuel tank 10 when the internal fuel pressure exceeds a specified value.

  The high-pressure fuel pump 13 is attached to a cylinder head cover 15 of the cylinder injection engine. Inside the cylinder head cover 15, an intake side camshaft 17a and an exhaust side camshaft 17b for opening and closing the intake valve and the exhaust valve 16 of each cylinder of the cylinder injection engine are provided. A cam 18 for driving the high-pressure fuel pump 13 is provided on one of the camshafts 17a and 17b (in the example shown in the figure, the exhaust-side camshaft 17b). The high pressure fuel pump 13 is connected to a delivery pipe 20 via a high pressure fuel passage 19. An injector 21 for each cylinder of the in-cylinder injection engine is connected to the delivery pipe 20.

  The delivery pipe 20 is provided with a relief valve 20a. The relief valve 20a is connected to the fuel tank 10 via a return passage 20b. The relief valve 20a opens when the fuel pressure in the delivery pipe 20 exceeds a specified relief pressure, and returns the fuel in the delivery pipe 20 to the fuel tank 10 through the return passage 20b. Thereby, the relief valve 20a maintains the fuel pressure of the delivery pipe 20 extending over the high-pressure fuel passage 19 below the relief pressure.

  As shown in FIG. 2, the high-pressure fuel pump 13 includes a pump body 22 that is fixed to the cylinder head cover 15 when installed in the direct injection engine. The pump body 22 is provided with a cylindrical cylinder 23 that opens to the inside of the cylinder head cover 15. A round bar-shaped plunger 24 is disposed in the cylinder 23 so as to be slidable back and forth. The plunger 24 is installed with one end inserted into the cylinder 23 and the other end protruding outside the cylinder 23. A pressurizing chamber 25 whose volume is changed by the reciprocating movement of the plunger 24 is formed inside the cylinder 23. In the following, the end of the plunger 24 on the side inserted into the cylinder 23 is referred to as an insertion end 24a, and the end of the plunger 24 on the side protruding to the outside of the cylinder 23 is referred to as a protrusion end 24b. The central axis of the plunger 24 is referred to as a plunger central axis PL.

  On the other hand, a fuel chamber 26 is formed inside the pump body 22. A pulsation damper 27 for reducing pulsation of the fuel pressure is installed in the fuel chamber 26. In a state where the high pressure fuel pump 13 is attached to the in-cylinder injection engine, the fuel chamber 26 is connected to the low pressure fuel passage 12. The fuel chamber 26 is connected to the pressurizing chamber 25 via an electromagnetic spill valve 28 attached to the pump body 22. The electromagnetic spill valve 28 is a normally-closed electromagnetic solenoid valve that closes in response to energization of the built-in electromagnetic solenoid 28a and blocks the flow of fuel between the fuel chamber 26 and the pressurizing chamber 25. The valve is opened in response to the stop of the energization to allow the fuel to flow between the fuel chamber 26 and the pressurizing chamber 25.

  A check valve 29 is attached to the pump body 22. In a state where the high pressure fuel pump 13 is attached to the in-cylinder injection engine, the pressurizing chamber 25 is connected to the high pressure fuel passage 19 via the check valve 29. The check valve 29 is a pressure-sensitive check valve, and opens when the fuel pressure in the pressurizing chamber 25 becomes equal to or higher than a predetermined discharge start pressure, and the check valve 29 is connected to the high-pressure fuel passage 19 from the pressurizing chamber 25. Allow fuel discharge.

  Further, the high pressure fuel pump 13 is a substantially cylindrical lifter interposed between the cam 18 and the end face 24c on the protruding end 24b side of the plunger 24 in a state where the high pressure fuel pump 13 is mounted on the cylinder injection type internal combustion engine. 30. The lifter 30 has a seating surface 30 a that faces the end surface 24 c of the plunger 24.

  In addition, an oil chamber 30 c is formed at a portion of the lifter 30 on the pump body 22 side so as to surround the protruding end 24 b of the plunger 24. Further, a roller 31 that can be brought into rolling contact with the cam 18 is rotatably supported at a portion of the lifter 30 on the cam 18 side. In the oil chamber 30c, oil sprayed from an oil shower installed in the cylinder head cover 15 is accumulated, and the oil is contacted between the roller 31 and the cam 18 through a small-diameter hole (not shown) formed in the lifter 30. To be supplied.

  On the other hand, a groove 24 d that goes around the outer periphery of the plunger 24 is formed in the vicinity of the protruding end 24 b of the plunger 24. The groove 24d constitutes the engaging portion. And the site | part of the inner peripheral side of the plate 32 is engaged with the groove | channel 24d.

  The plate 32 is formed of an annular plate member whose inner peripheral portion is convex toward the pump body 22 side. In this plate 32, the thickness (width in the sliding direction of the plunger 24) of the inner peripheral portion fitted in the groove 24d is made smaller than the width of the groove 24d in the reciprocating sliding direction of the plunger 24. Yes. That is, the plate 32 is fitted in the groove 24d with a gap in the reciprocating sliding direction of the plunger 24.

  A spring 33 is interposed between the outer peripheral portion of the plate 32 and the pump body 22 to urge the plunger 24 in a direction in which the plunger 24 is separated from the pressurizing chamber 25. The urging force of the spring 33 is transmitted to the plunger 24 through the plate 32. The end surface 24 c of the plunger 24 is pressed against the seat surface 30 a of the lifter 30 by the urging force of the spring 33.

FIG. 3 shows an enlarged cross-sectional view of the groove 24d and the plate 32. As shown in FIG. Hereinafter, the portion of the plate 32 on the inner peripheral side and fitted in the groove 24d is referred to as an “inner peripheral portion”.
As shown in FIG. 3, the inner peripheral portion 32 a of the plate 32 is formed by a wall surface 24 e of the groove 24 d (a surface orthogonal to the plunger central axis PL and a surface on the end surface 24 c side of the plunger 24) by the urging force of the spring 33. ). At the end of the inner peripheral portion 32a of the plate 32, a convex portion 32b protruding toward the wall surface 24e is formed. The convex portions 32b are preferably formed continuously in an annular shape, but may be formed in an annular shape at predetermined intervals.

  Due to the formation of the convex portion 32b, the distance D between the wall surface 24e of the groove 24d with which the inner peripheral portion 32a of the plate 32 contacts and the inner peripheral portion 32a of the plate 32 opposed to the wall surface 24e is determined by the plunger central axis PL. The far part is longer than the near part.

  That is, in a state where the plate 32 is not inclined with respect to the plunger 24 and the convex portion 32b of the plate 32 and the wall surface 24e are in contact with each other, the convex portion 32b of the plate 32 corresponding to “a portion near the plunger central axis PL” The distance D1 at the contact portion with the wall surface 24e is “0”. Then, a distance D2 at a facing portion where the portion where the convex portion 32b is not formed in the inner peripheral portion 32a of the plate 32 and the wall surface 24e is equivalent to “a portion far from the plunger central axis PL” is from “0”. Further, the length is longer, more specifically, the length according to the protruding amount of the protrusion 32b.

Next, the operation of the high pressure fuel pump 13 configured as described above will be described.
In the high-pressure fuel pump 13, the plunger 24 reciprocates with respect to the cylinder 23 in response to the lifter 30 being pushed up and down by the cam 18. Then, when the plunger 24 moves to the insertion end 24a side, the volume of the pressurizing chamber 25 decreases, and when the plunger 24 moves to the protruding end 24b side, the volume of the pressurizing chamber 25 increases. In the following, the movement toward the insertion end 24a is referred to as the raising of the plunger 24, and the movement toward the protruding end 24b is referred to as the lowering of the plunger 24.

  When the plunger 24 is lowered with the electromagnetic spill valve 28 opened and the volume of the pressurizing chamber 25 is increased, fuel flows from the fuel chamber 26 into the pressurizing chamber 25. Thereafter, when the electromagnetic spill valve 28 is closed while the plunger 24 is raised, the pressure of the fuel sealed inside rises as the volume of the pressurizing chamber 25 is reduced. When the fuel pressure in the pressurizing chamber 25 reaches the discharge start pressure and the check valve 29 is opened, the pressurized fuel in the pressurizing chamber 25 is discharged to the high pressure fuel passage 19, and the high pressure fuel passage 19 To the delivery pipe 20.

  While the plunger 24 is raised, the spring 33 is compressed, and a lateral force is generated in the spring. When such a lateral force is applied to the plunger 24, a moment in a direction in which the axis of the plunger 24 is tilted is generated, whereby the plunger 24 is tilted with respect to the cylinder 23. When the inclination of the plunger 24 increases, the sliding resistance of the plunger 24 with respect to the cylinder 23 increases, which may cause, for example, abnormal wear or seizure.

  In this respect, in the high-pressure fuel pump 13 of the present embodiment, as described above, by providing the projection 32b on the plate 32, the wall surface 24e of the groove 24d with which the inner peripheral portion 32a of the plate 32 contacts and the wall surface 24e The distance D between the opposing inner peripheral portion 32a of the plate 32 is longer at a portion farther than a portion closer to the central axis of the plunger.

  Therefore, as shown in FIG. 4, when the plate 32 is tilted by the lateral force generated by the compression of the spring 33, the plate 32 is located at a portion far from the plunger central axis PL in the groove 24 d, for example, at the corner K near the outer peripheral surface of the plunger 24. Can be prevented from touching. The plate 32 comes into contact with the convex portion 32b at a portion close to the plunger central axis PL in the groove 24d.

  Thus, when the plate 32 comes into contact with the groove 24d at a portion close to the plunger central axis PL, the spring 33 in the plunger 24 is compared with the case where the plate 32 comes into contact with the corner portion K far from the plunger central axis PL. The distance L between the point S at which the urging force acts and the plunger central axis PL becomes shorter. Therefore, the moment acting on the groove 24d by the urging force of the spring 33, that is, the moment in the direction in which the axis of the plunger 24 is inclined is reduced.

According to this embodiment described above, the following effects can be obtained.
(1) By providing the convex part 32b in the inner peripheral part 32a of the plate 32, the wall surface 24e of the groove 24d with which the inner peripheral part 32a of the plate 32 contacts and the inner peripheral part 32a of the plate 32 facing this wall surface 24e The distance D between them is made longer at the part far from the part near the plunger central axis PL. For this reason, the moment in the direction in which the axis of the plunger 24 is inclined is reduced, and the inclination of the plunger 24 caused by the compression of the spring 33 is suppressed.

(2) Since the moment acting on the groove 24d by the urging force of the spring 33 is reduced, the durability of the groove 24d is also improved.
(Second Embodiment)
Next, a second embodiment of the high-pressure fuel pump will be described in detail with reference to FIGS. In addition, in this embodiment, about the structure which is common in the said embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 5, the inner peripheral portion 32 c of the plate 32 included in the high-pressure fuel pump according to the present embodiment contacts the wall surface 24 e of the groove 24 d by the urging force of the spring 33. And the plate 32 of this embodiment is not provided with the convex part 32b demonstrated in 1st Embodiment, and the inner peripheral part 32c of the plate 32 fitted by the groove | channel 24d is the wall surface 24e, so that it approaches the plunger central axis PL. The thickness (the width in the sliding direction of the plunger 24) increases toward the side.

  As a result of the formation of the inner peripheral portion 32c whose thickness changes in this manner, the space between the wall surface 24e of the groove 24d that the inner peripheral portion 32c of the plate 32 contacts and the inner peripheral portion 32c of the plate 32 that faces the wall surface 24e. The distance D is set to be longer in a portion far from the portion closer to the plunger central axis PL. More specifically, the distance D becomes longer as it goes from a portion closer to the plunger central axis PL to a portion farther away.

  Therefore, as shown in FIG. 6, when the plate 32 is inclined by the lateral force generated by the compression of the spring 33, the plate 32 is located at a portion far from the plunger central axis PL in the groove 24 d, for example, at a corner K near the outer peripheral surface of the plunger 24. Can be prevented from touching. Since the end of the inner peripheral portion 32c comes into contact with the wall surface 24e, the plate 32 comes into contact with the groove 24d at a portion close to the plunger central axis PL.

  Thus, since the plate 32 comes into contact with the groove 24d at a portion close to the plunger central axis PL, the same effect as the first embodiment can be obtained. That is, the distance L between the point S where the urging force of the spring 33 acts on the plunger 24 and the plunger central axis PL is shortened as compared with the case where the plate 32 contacts the corner portion K far from the plunger central axis PL. . Therefore, the moment acting on the groove 24d by the urging force of the spring 33, that is, the moment in the direction in which the axis of the plunger 24 is inclined is reduced. Therefore, the inclination of the plunger 24 caused by the compression of the spring 33 can be suppressed.

Further, since the moment acting on the groove 24d by the urging force of the spring 33 is reduced, the durability of the groove 24d is also improved.
(Third embodiment)
Next, a third embodiment of the high-pressure fuel pump will be described in detail with reference to FIGS. In addition, in this embodiment, about the structure which is common in the said 1st Embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 7, the inner peripheral portion 32a of the plate 32 provided in the high-pressure fuel pump of this embodiment is flat and has a uniform thickness, and the wall surface 24p of the groove 24d (plunger central axis PL) is urged by the urging force of the spring 33. To the end surface 24c side of the plunger 24). And the said wall surface 24p facing the inner peripheral part 32a of the plate 32 is formed as follows.

  That is, the distance D between the wall surface 24p of the groove 24d with which the inner peripheral portion 32a of the plate 32 comes into contact and the inner peripheral portion 32a of the plate 32 facing the wall surface 24p is made shorter as it approaches the plunger central axis PL. It is formed in the shape of a taper that is slanted.

  Due to the formation of the tapered wall surface 24p, the distance D between the wall surface 24p of the groove 24d with which the inner peripheral portion 32a of the plate 32 contacts and the inner peripheral portion 32a of the plate 32 facing the wall surface 24p is The part far from the axis PL is made longer than the part close to the axis PL. More specifically, the distance D becomes longer as it goes from a portion closer to the plunger central axis PL to a portion farther away.

  Therefore, as shown in FIG. 8, when the plate 32 is inclined by the lateral force generated by the compression of the spring 33, the plate 32 is located at a portion far from the plunger central axis PL in the groove 24 d, for example, at a corner K near the outer peripheral surface of the plunger 24. Can be prevented from touching. Since the end of the inner peripheral portion 32a comes into contact with the wall surface 24p, the plate 32 comes into contact with the portion close to the plunger central axis PL in the groove 24d.

Thus, since the plate 32 comes into contact with the groove 24d at a portion close to the plunger central axis PL, the same effect as the first embodiment can be obtained.
That is, the distance L between the point S where the urging force of the spring 33 acts on the plunger 24 and the plunger central axis PL is shortened as compared with the case where the plate 32 contacts the corner portion K far from the plunger central axis PL. . Therefore, the moment acting on the groove 24d by the urging force of the spring 33, that is, the moment in the direction in which the axis of the plunger 24 is inclined is reduced. Therefore, the inclination of the plunger 24 caused by the compression of the spring 33 can be suppressed.

Further, since the moment acting on the groove 24d by the urging force of the spring 33 is reduced, the durability of the groove 24d is also improved.
In addition, each said embodiment can also be changed and implemented as follows.

  -In 1st Embodiment, the convex part 32b which protruded in the wall surface 24e side was formed in the terminal of the inner peripheral part 32a of the plate 32. As shown in FIG. In addition, as shown in FIG. 9, a convex part 32b similar to that of the first embodiment is provided by providing an annular concave part 32d on the inner peripheral part 32a of the plate 32 and facing the wall surface 24e. May be formed.

  -You may implement combining said each embodiment suitably. For example, you may provide the convex part 32b of the plate 32 demonstrated in 1st Embodiment in the internal peripheral part 32c of the plate 32 demonstrated in 2nd Embodiment. Moreover, you may combine the plate 32 demonstrated in 1st Embodiment, and the wall surface 24p demonstrated in 3rd Embodiment. Moreover, you may combine the plate 32 demonstrated in 2nd Embodiment, and the wall surface 24p demonstrated in 3rd Embodiment. Moreover, while providing the convex part 32b of the plate 32 demonstrated in 1st Embodiment in the internal peripheral part 32c of the plate 32 demonstrated in 2nd Embodiment, the plate 32 provided in this way and the wall surface 24p demonstrated in 3rd Embodiment You may combine.

  -In each embodiment and its modification, although the groove 24d was provided in the plunger 24 as an engaging part which engages the plate 32 and the plunger 24, you may provide the engaging part different from a groove | channel. For example, as shown in FIG. 10, a flange portion 24f extending in the radial direction of the plunger 24 is provided at the protruding end 24b of the plunger 24 so that the flange portion 24f and the inner peripheral portion 32a of the plate 32 are engaged with each other. Good. Even in this case, it is possible to obtain the operational effects according to the above-described embodiments and the modifications thereof.

  DESCRIPTION OF SYMBOLS 10 ... Fuel tank, 11 ... Feed pump, 12 ... Low pressure fuel passage, 13 ... High pressure fuel pump, 14 ... Regulator, 15 ... Cylinder head cover, 16 ... Exhaust valve, 17a ... Intake side camshaft, 17b ... Exhaust side camshaft, DESCRIPTION OF SYMBOLS 18 ... Cam, 19 ... High pressure fuel passage, 20 ... Delivery pipe, 20a ... Relief valve, 20b ... Return passage, 21 ... Injector, 22 ... Pump body, 23 ... Cylinder, 24 ... Plunger, 24a ... Insertion end, 24b ... Projection End, 24c ... End face, 24d ... Groove, 24e ... Wall surface, 24f ... Flange, 24p ... Wall surface, 25 ... Pressurizing chamber, 26 ... Fuel chamber, 27 ... Pulsation damper, 28 ... Electromagnetic spill valve, 28a ... Electromagnetic solenoid 29 ... Check valve, 30 ... Lifter, 30a ... Seat surface, 30c ... Oil chamber, 31 ... Roller, 32 ... Pre 32a, 32c ... inner peripheral part, 32b ... convex part, 32d ... concave part, 33 ... spring, 50 ... pump body, 51 ... cylinder, 52 ... plunger, 52a ... end face, 52b ... groove, 53 ... cam, 54 ... Lifter 56... Spring, 57. Pressure chamber, 58. Plate, PL. Plunger central axis, K.

Claims (4)

A cylindrical cylinder;
A rod-like plunger disposed at one end inside the cylinder and arranged to be reciprocally slidable with respect to the cylinder in a state where the other end protrudes outside the cylinder;
A pressurizing chamber defined in the cylinder;
A spring that biases the plunger in a direction away from the pressurizing chamber;
An annular plate that is a member that transmits the urging force of the spring to the plunger and is engaged with an engagement portion provided on the other end side of the plunger;
A high pressure fuel pump comprising:
The distance between the wall surface of the engaging portion that is in contact with the inner peripheral portion of the plate by the biasing force of the spring and the inner peripheral portion of the plate facing the wall surface is close to the central axis of the plunger. A high-pressure fuel pump characterized in that the part far from the part is longer. The high-pressure fuel pump according to claim 1, wherein a convex portion that protrudes toward the wall surface is formed at a portion on the inner peripheral side of the plate. 2. The high-pressure fuel pump according to claim 1, wherein the portion of the plate on the inner peripheral side is formed such that the thickness increases toward the wall surface as it approaches the central axis of the plunger. 2. The high-pressure fuel pump according to claim 1, wherein the wall surface facing the portion on the inner peripheral side of the plate is formed in a tapered shape that is inclined so that the distance becomes shorter as it approaches the central axis of the plunger.