JP2018119479A - High pressure fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure fuel pump which includes a plunger seal protection mechanism while achieving simplification of a component shape.SOLUTION: A high pressure fuel pump includes: a compression chamber which compresses a fuel; a plunger which increases or decreases volumetric capacity of the compression chamber; a plunger seal which is disposed at an outer periphery part of the plunger to make a fuel seal; a plunger seal holding part which holds the plunger seal; and a plunger seal protection part which is disposed above the plunger seal in an axial direction and protects the plunger seal. A taper surface or curved surface is formed at the plunger seal protection part, and the high pressure fuel pump is configured so that an axial position of the plunger seal protection part is defined by the taper surface or the curved surface.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a high pressure fuel pump, and more particularly to a high pressure fuel pump provided with a plunger seal protection member.

  As a background art in this technical field, there is, for example, Japanese Patent Application Laid-Open No. 2006-118211. According to Patent Document 1, “the plunger seal 13 is held at the lower end of the spring holder 7 by the seal holder 15 and the spring holder 7 that are press-fitted and fixed to the inner peripheral cylindrical surface 7 c of the spring holder 7. Is held coaxially with the central axis of the inner peripheral cylindrical surface 7c of the spring holder 7 and simultaneously with the central axis of the cylindrical fitting portion 7e. The plunger seal 13 prevents the fuel in the seal chamber 10f from flowing into the engine on the side of the tappet 3. At the same time, the sliding portion in the engine room is lubricated. "Lubricant (including engine oil) is prevented from flowing into the pump body 1" (paragraph 00). 78, 0079).

JP-A-2006-118211

  In Patent Document 1, the plunger seal 13 (lip seal) has a fixing surface for fixing to the cylinder holder 7 using the seal holder 15. For this reason, the seal holder 15 is provided with a plunger seal protection function so that the plunger 2 is not in direct contact with the plunger seal 13 to be damaged.

  However, when the plunger seal 13 having no fixed surface is used, there is no fixed surface, and the plunger seal 13 is held only by the urging force of the plunger seal itself. For example, in the case of a dual spring type plunger seal, there is a type having no fixed surface. For this reason, the seal holder must be held only by the tight force of the seal holder and the cylinder holder without contacting the plunger seal.

  Here, when the tension force of the seal holder is small, when the plunger comes into contact, the seal holder may move and damage the plunger seal. Therefore, it is necessary that the seal holder does not move even if the plunger contacts the seal holder. As an axial holding mechanism of the seal holder, for example, a collar portion can be provided on the seal holder, and the movement in the axial direction can be regulated by abutting against the flat portion of the cylinder holder. However, there is a problem that providing the collar portion increases the mass of the component and further complicates the structure.

  It is an object of the present invention to provide a high-pressure fuel pump provided with a plunger seal protection mechanism while simplifying the component shape.

  In order to solve the above problems, the present invention provides a pressurizing chamber for pressurizing fuel, a plunger for increasing or decreasing the volume of the pressurizing chamber, a plunger seal disposed on the outer periphery of the plunger and performing a fuel seal, A plunger seal holding portion that holds the plunger seal; and a plunger seal protection portion that is arranged on the upper side in the axial direction with respect to the plunger seal and protects the plunger seal, and the plunger seal protection portion has a tapered surface or a curved surface. The high-pressure fuel pump is configured so that a surface is formed and the position of the plunger seal protection portion in the axial direction is determined by the tapered surface or the curved surface.

  According to the present invention, it is possible to provide a high-pressure fuel pump provided with a plunger seal protection mechanism while simplifying the component shape.

It is a figure explaining the whole block diagram of the fuel supply system which returns a high pressure fuel to a low pressure side by a relief valve mechanism. It is a figure explaining the whole fuel supply system block diagram which returns a high pressure fuel to the pressurization chamber side by a relief valve mechanism. It is a longitudinal cross-sectional view of the high pressure fuel supply pump by a present Example. It is sectional drawing of the plunger seal protection mechanism taper surface type of Example 1. FIG. It is sectional drawing of the plunger seal protection mechanism curved surface type of Example 1. FIG. It is sectional drawing of the plunger seal protection mechanism taper surface type of Example 2. FIG. It is sectional drawing of the plunger seal protection mechanism curved surface type of Example 2. FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall configuration of a fuel system to which a high-pressure fuel supply pump according to an embodiment of the present invention is applied. A portion surrounded by a broken line in FIG. 1 shows a pump housing 1 of a high-pressure fuel supply pump, and a mechanism and parts shown in the broken line are integrally incorporated therein. FIG. 2 is a diagram illustrating an overall configuration diagram of a fuel supply system that returns high-pressure fuel to the pressurizing chamber side by a relief valve mechanism. FIG. 3 is a longitudinal sectional view of the high-pressure fuel supply pump according to this embodiment.

  The fuel in the fuel tank 20 is pumped up by the feed pump 21 and sent to the fuel inlet 10 a of the pump housing 1 through the suction pipe 28. The fuel that has passed through the fuel intake port 10a reaches the intake port 30a of the electromagnetic intake valve mechanism 30 that constitutes the variable capacity mechanism via the pressure pulsation reducing mechanism 9 and the intake passage 10c.

  As shown in FIG. 3, the fuel that has passed through the suction port 10a passes through the filter 102 fixed in the suction joint 101, and further constitutes a variable capacity mechanism via the suction flow path 10b and the metal diaphragm dampers 9 and 10c. The suction port 30a of the electromagnetically driven valve mechanism 30 is reached.

  The electromagnetic suction valve mechanism 30 includes an electromagnetic coil 30b, and in a state where the electromagnetic coil 30b is energized, the electromagnetic plunger 30c compresses the spring 33 and moves to the right in FIG. Maintained. At this time, the suction valve body 31 attached to the tip of the electromagnetic plunger 30c opens the suction port 32 leading to the pressurizing chamber 11 of the high-pressure fuel supply pump. When the electromagnetic coil 30 b is not energized and there is no fluid differential pressure between the suction passage 10 c (suction port 30 a) and the pressurizing chamber 11, the suction valve body 31 is moved by the biasing force of the spring 33. The suction port 32 is urged in the valve closing direction (leftward in FIG. 1) to be closed, and this state is maintained.

  When the plunger 2 is displaced downward in FIG. 1 due to the rotation of the cam of the internal combustion engine, which will be described later, and the suction chamber 11 is in the suction process state, the volume of the pressurizing chamber 11 increases and the fuel pressure therein decreases. In this step, when the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction passage 10c (suction port 30a), the suction valve body 31 has a valve opening force (suction valve body 31 shown in FIG. 1) is generated. By this valve opening force, the suction valve body 31 overcomes the urging force of the spring 33 and opens to open the suction port 32. In this state, when a control signal from the ECU 27 is applied to the electromagnetic intake valve mechanism 30, an electric current flows through the electromagnetic coil 30b of the electromagnetic intake valve 30, and the electromagnetic plunger 30c further compresses the spring 33 by the magnetic biasing force. It moves to the right in FIG. 1 and maintains the state where the inlet 32 is open.

  When the plunger 2 shifts from the suction process to the compression process (the ascending process from the lower start point to the upper start point) while maintaining the application state of the input voltage to the electromagnetic intake valve mechanism 30, the energized state of the electromagnetic coil 30b is changed. Since it is maintained, the magnetic urging force is maintained, and the suction valve body 31 still maintains the opened state. The volume of the pressurizing chamber 11 decreases with the compression movement of the plunger 2. In this state, the fuel once sucked into the pressurizing chamber 11 is once again opened into the intake valve body 31 and the inlet 32. Between the pressure chamber 11 and the suction passage 10c (suction port 30a), the pressure in the pressurizing chamber 11 does not increase. This process is called a return process.

  In the returning step, when the energization to the electromagnetic coil 30b is cut off, the magnetic urging force acting on the electromagnetic plunger 30c is erased after a certain time (after magnetic and mechanical delay time). Then, the suction valve body 31 is moved leftward in FIG. 1 by the urging force of the spring 33 that is constantly acting on the suction valve body 31 to close the suction port 32. When the suction port 32 is closed, the fuel pressure in the pressurizing chamber 11 rises with the rise of the plunger 2 from this time. When the fuel pressure in the pressurizing chamber 11 exceeds a pressure larger than the fuel pressure in the discharge port 13 by a predetermined value, the fuel remaining in the pressurizing chamber 11 is discharged via the discharge valve mechanism 8. High pressure discharge is performed and supplied to the common rail 23. This process is called a discharge process. As described above, the compression process of the plunger 2 includes a return process and a discharge process.

  During the returning process, the pressure pulsation is generated in the suction passage due to the fuel returned to the suction passage 10c, but this pressure pulsation only slightly flows backward from the suction port 10a to the suction pipe 28, and the fuel is returned. Most of the energy is absorbed by the pressure pulsation reducing mechanism 9.

  By controlling the timing of releasing the energization of the electromagnetic coil 30c of the electromagnetic intake valve mechanism 30, the amount of high-pressure fuel discharged can be controlled. If the timing of releasing the energization to the electromagnetic coil 30b is advanced, the ratio of the return process in the compression process is reduced and the ratio of the discharge process is increased. That is, the amount of fuel returned to the suction passage 10c (suction port 30a) is reduced and the amount of fuel discharged at high pressure is increased. On the other hand, if the timing of releasing the energization is delayed, the ratio of the return process in the compression process is increased and the ratio of the discharge process is decreased. That is, more fuel is returned to the suction passage 10c and less fuel is discharged at high pressure. The timing of releasing the energization is controlled by a command from the ECU.

  As described above, the ECU controls the timing of releasing the energization of the electromagnetic coil, whereby the amount of fuel discharged at high pressure can be set to the amount required by the internal combustion engine.

  In the pump housing 1, a discharge valve mechanism 8 is provided on the outlet side of the pressurizing chamber 11 between the discharge port (discharge side pipe connection portion) 13. The discharge valve mechanism 8 includes a sheet member 8a, a discharge valve 8b, a discharge valve spring 8c, and a holding member (discharge valve stopper) 8d. In a state where there is no fuel differential pressure between the pressurizing chamber 11 and the discharge port 13, the discharge valve 8b is pressed against the seat member 8a by the urging force of the discharge valve spring 8c and is in a closed state. When the fuel pressure in the pressurizing chamber 11 exceeds a pressure larger than the fuel pressure in the discharge port 13 by a predetermined value, the discharge valve 8b opens against the discharge valve spring 8c, and the pressure chamber 11 opens. The fuel is discharged to the common rail 23 through the discharge port 13.

  After the discharge valve 8b is opened, its operation is restricted when it comes into contact with the holding member 8d. Therefore, the stroke of the discharge valve 8b is appropriately determined by the holding member 8d. If the stroke is too large, the fuel discharged to the fuel discharge port 13 flows back into the pressurizing chamber 11 again due to the delay in closing the discharge valve 8b, so that the efficiency of the high-pressure pump decreases. . Further, when the discharge valve 8b repeats opening and closing movements, the holding member 8d guides the discharge valve so as to move only in the stroke direction. By configuring as described above, the discharge valve mechanism 8 becomes a check valve that restricts the flow direction of fuel.

  Thus, the fuel introduced to the fuel suction port 10a is pressurized to a required amount by the reciprocating motion of the plunger 2 in the pressurizing chamber 11 of the pump body 1, and the fuel discharge port 13 passes through the discharge valve mechanism 8. To the common rail 23, which is a high-pressure pipe.

  An injector 24 and a pressure sensor 26 are attached to the common rail 23. The injectors 24 are mounted in accordance with the number of cylinders of the internal combustion engine, and the fuel is injected into the cylinders by operating the on-off valve according to the control signal of the ECU 27.

  Next, the fuel relief operation in the first embodiment when an abnormal high pressure occurs in the high pressure portion such as the common rail 23 due to a failure of the injector 24 or the like will be described.

  The pump housing 1 is provided with a relief passage 300 that connects the discharge passage 12 and the suction passage 10c. The relief passage 300 restricts the flow of fuel in only one direction from the discharge passage 12 to the suction passage 10c. A valve mechanism 200 is provided. A pressurizing chamber 11 for pressurizing the fuel, a discharge valve mechanism 8 disposed on the downstream side of the pressurizing chamber 11, and fuel in the discharge passage 12 on the downstream side of the discharge valve mechanism 8 are returned to the suction passage 10c which is a low-pressure passage. And a relief valve mechanism.

  In addition, as shown in FIG. 2, the fuel flow in the relief passage 300 may flow from the discharge passage 12 into the pressurizing chamber 11. That is, the relief valve mechanism 200 of this embodiment may return the fuel in the discharge passage 12 on the downstream side of the discharge valve mechanism 8 to the pressurizing chamber 11.

  As shown in FIG. 3, the fuel that has passed through the suction port 10a passes through a filter fixed in the suction joint 32, and further functions as a variable capacity mechanism via the suction flow path 10b, the metal diaphragm damper 9, and the low-pressure fuel chamber 10c. It reaches the suction port 30a of the electromagnetically driven valve mechanism 30 to be configured. The pump housing 1 is formed with a recess 1A for accommodating the cylinder 6 including the pressurizing chamber 11 in the center, and a hole 30A for mounting the electromagnetic suction valve mechanism 30 is formed so as to communicate with the pressurizing chamber 11. Has been. The pump housing 1 is formed with a recess 1A for accommodating a cylinder 6 including a pressurizing chamber 11 at the center. A hole 11A for mounting the discharge valve mechanism 8 is provided in the cylinder so as to open to the pressurizing chamber 11. 6 is formed in a direction intersecting with the recess 1 </ b> A for housing 6.

The lower end of the plunger 2 is provided with a tappet 3 that converts the rotational motion of the cam 5 attached to the camshaft of the engine into vertical motion and transmits it to the plunger 2. The plunger 2 is pressure-bonded to the tappet 3 by a spring 4 via a retainer 16. The retainer 15 is fixed to the plunger 2 by press-fitting. As a result, the plunger 2 can be moved back and forth (reciprocated) up and down as the cam 5 rotates.
The flange 41 fixes the pump housing 1 to the engine by two set screws 42. Therefore, when the pump housing 1 is lifted upward as described above, the flange 42 is in a state where the two set screws 42 and the bush 43 are fixed and a bending load is repeatedly applied to the central portion. Due to this repeated load, the flange 41 and the pump housing 1 are deformed, so that there is a problem in that repeated stress is generated and fatigue failure occurs. Furthermore, the sliding portion of the cylinder 6 is also deformed, and the above-described seizure and sticking between the plunger 2 and the cylinder 6 occurs.
The cylinder 6 contacts the hole of the pump body 1 at the upper part of the large diameter part 6a. The spring holder 7 is configured such that the cylinder 6 is in contact with the outer diameter portion of the large diameter portion 6a in the radial direction at the upper inner diameter portion 7a and also in the axial direction. The pump body 1 is formed with a female thread portion 1b, and a male thread portion 7g formed on the outer diameter side of the spring holder 7 is screwed into the female thread portion 1b, whereby the cylinder 6 is biased upward in the axial direction. Fixed to the pump body 1. Reference numerals 61 and 62 denote O-rings, which are arranged in grooves formed in the spring holder 7 so that fuel does not leak to the cylinder block side or the outside.

The flange 41 is manufactured by press molding for productivity reasons. Therefore, the plate thickness t1 of the flange 41 has an upper limit, and in this embodiment, t1 = 4 mm. A welded portion 41a, which is a joint between the pump housing 1 and the flange 42, is welded and joined by laser welding. In laser welding, it is necessary to irradiate a beam from below in the figure. From the top in the figure, there are other parts, and it is impossible to irradiate the laser over the entire circumference. Furthermore, the laser welding must penetrate the plate thickness t = 4 mm of the flange 41. If the welding does not penetrate the flange 41, the end face of the welded portion becomes a notch, and stress concentrates on the notched portion due to the above-described repeated load, causing fatigue failure therefrom.
In order to weld through the flange 41 by laser welding, it is sufficient to increase the output of the laser. However, since heat is always generated for welding, the flange 41 is thermally deformed by the heat. Further, a large amount of spatter generated during welding is generated and fixed to the pump housing 1 and other components. From the above viewpoint, the welding length for through welding by laser welding is better. Therefore, in this embodiment, only the plate thickness t2 of the welded portion 41a is set to t2 = 3 mm. Thereby, the flange 41a can be through-welded by laser welding, and the occurrence of spatter can be minimized. Further, since this t2 = 3 mm portion can be formed by press molding, the productivity is high.

  The bush 43 includes a flange portion 43a and a caulking portion 43b. First, the caulking portion 43 b is caulked and coupled to the mounting hole of the flange 41. Thereafter, the pump housing 1 and the welded portion 41a are welded together by laser welding. Thereafter, the resin fastener 44 is inserted into the bush 43, and the set screw 42 is inserted into the fastener 44. The fastener 44 serves to temporarily fix the set screw 42 to the bush 43. That is, the set screw 42 is fixed so as not to fall off the bush 43 until the high-pressure fuel supply pump is attached to the engine. When the high pressure fuel supply pump is fixed to the engine, the set screw 42 is screwed and fixed to a screw portion provided on the engine side. At that time, the set screw 42 is rotated in the bush 43 by the tightening torque of the set screw 42. it can.

  The plunger seal 13 is held at the lower end of the spring holder 7 by a seal holder 15 and a spring holder 7 that are press-fitted and fixed to the inner peripheral cylindrical surface 7 c of the plunger seal holder. The plunger seal 13 is held by the inner peripheral cylindrical surface 7c of the spring holder 7 so that its axis is coaxial with the axis of the cylindrical fitting portion 7e. The plunger 2 and the plunger seal 13 are slidably installed at the lower end of the cylinder 6 in the figure.

  Conventional plunger seals have a fixing surface for fixing to a plunger seal holding portion (cylinder holder) using a seal holder. For this reason, the seal holder is provided with a plunger seal protection function so that the plunger does not directly contact the plunger seal and is not damaged.

  However, when a plunger seal having no fixed surface is used, there is no fixed surface, and the plunger seal itself is held only by the urging force. For example, in the case of a dual spring type plunger seal, there is a type having no fixed surface. For this reason, the seal holder must be held only by the pressing force of the seal holder and the plunger seal holding portion without contacting the plunger seal.

  Here, when the tension force of the seal holder is small, when the plunger comes into contact, the seal holder may move and damage the plunger seal. Therefore, it is necessary that the seal holder does not move even if the plunger contacts the seal holder. As an axial holding mechanism of the seal holder, for example, a collar portion is provided on the seal holder, and the movement in the axial direction can be regulated by abutting against the flat portion of the plunger seal holding portion. However, there is a problem that providing the collar portion increases the mass of the component and further complicates the structure.

  In this embodiment, as a method of holding the seal holder, in addition to the radial force, the plunger seal holding portion and the seal holder are provided with a taper, and the plunger seal can be controlled in the axial direction by contacting the taper portion. An object of the present invention is to provide a high-pressure fuel pump provided with a protection mechanism. In addition, since the part shape can be simplified, the part cost can be reduced and the part weight can be reduced.

  FIG. 4 shows a cross section of the plunger seal protection mechanism according to this embodiment. Plunger seal 100 is installed for the fuel seal and oil seal inside and outside the pump. The plunger seal 100 is held by the radial compression force generated by the plunger seal spring 101 between the plunger seal 100 and the plunger seal holding portion 102. In this embodiment, the plunger seal holder 102 is constituted by a cylinder holder that holds a cylinder. Further, the plunger seal 100 and the plunger 2 are also held by the radial compression force generated by the plunger seal spring 101. When the vertical position of the plunger 2 is not fixed, specifically, the plunger 2 is lowered downward in FIG. 4 until the pump is mounted on the engine head. At that time, the plunger 2 directly contacts the plunger seal 100 and a seal holder 103 as a plunger seal protection member is provided to protect the plunger seal 100 so as not to damage the plunger seal 100.

  The plunger seal 100 is exposed to oil on the outside of the pump. Since the plunger seal 100 is a resin material, changes in the fuel temperature and the oil temperature affect the decrease in the strength of the plunger seal. The temperature of the plunger seal 100 also rises due to sliding heat generated by the plunger 2 sliding up and down. Basically, the strength decreases as the temperature of the plunger seal 100 increases. Therefore, it is necessary to provide a gap between the seal holder 103 and the plunger seal 101 on the inner side of the pump exposed to the fuel so as to circulate the fuel having a temperature lower than that of the oil. By doing so, the plunger seal 100 can be cooled by the fuel. In order to ensure the clearance and cool the plunger seal, it is important to provide holding surfaces not only in the radial direction but also in the axial direction.

  In this embodiment, a seal holder taper surface 103a is provided on the plunger seal side of the seal holder 103, and a similar plunger seal holding portion taper surface 102a is provided on the plunger seal holding portion 102, and the seal holder taper surface 103a and the plunger seal holding portion are provided. Abutting the tapered surface 102a enables holding in the axial direction. Desirably, the taper angles of the plunger seal holding portion taper surface 102a and the seal holder taper surface 103a are matched. Furthermore, the plunger seal holding portion taper surface 102a can be used as a peep when the plunger seal 100 is inserted. The seal holder tapered surface 103a provided on the seal holder 103 can also be used as a peep when the seal holder 103 itself is press-fitted.

  In this embodiment, the contact surface is a tapered surface, but as shown in FIG. 5, the plunger seal holding portion curved surface 102b instead of the plunger seal holding portion tapered surface 102a, and the seal holder curved surface 102b instead of the seal holder tapered surface 103a. But the axial holding function can be demonstrated

  If either the seal holder 103 or the plunger seal holding portion 102 is provided with a tapered surface / curved surface, the axial holding function is exhibited by either of them, and the same effect can be obtained.

  As described above, the high-pressure fuel pump of this embodiment includes a pressurizing chamber 11 that pressurizes fuel, a plunger 2 that increases and decreases the volume of the pressurizing chamber 11, and a plunger seal 100 that is disposed on the outer peripheral portion of the plunger 2 and performs fuel sealing. (Lip seal) and a plunger seal holding portion 102 that holds the plunger seal 100 (lip seal). The plunger seal holder 102 may be constituted by the spring holder 7 or the cylinder holder shown in FIG. 3, but the present invention is not limited to this. The high-pressure fuel pump includes a plunger seal protection unit 103 that is disposed on the upper side in the axial direction with respect to the plunger seal 100 (lip seal) and protects the plunger seal 100 (lip seal). The plunger seal protection unit 103 corresponds to the seal holder 15 of FIG. 3 and protects the plunger seal 100 from coming into contact with the plunger seal 100 when the plunger 2 falls. The plunger seal protection portion 103 is formed with a tapered surface 103a or a curved surface, and the axial position of the plunger seal protection portion 103 is determined by the tapered surface 103a or the curved surface. It is desirable that the plunger seal protection part 103 is formed with a tapered surface 103a or a curved surface, and the axial position of the plunger seal protection part 103 is determined only by the tapered surface 103a or the curved surface.

  Further, as shown in FIG. 3, the plunger seal holding portion 102 is formed with a tapered surface 102a or a curved surface, and the axial position of the plunger seal protection portion 103 is determined by the tapered surface 102a or the curved surface. The plunger seal holding portion 102 is formed with a tapered surface 102a or a curved surface, and the axial position of the plunger seal protection portion 103 is determined only by the tapered surface 102a or the curved surface. That is, the taper surface 103a or the curved surface of the plunger seal protection portion 103 and the taper surface 102a or the curve surface of the plunger seal holding portion 102 are configured in a corresponding shape, and the plunger seal protection portion 103 is brought into contact with each other by contacting them. It is fixed in the axial direction. Further, it is desirable that a gap is formed over the whole so that the plunger seal protection portion 103 and the plunger seal holding portion 102 do not contact each other in the axial direction.

  6 and 7 show a second embodiment of the present invention. The present embodiment has the characteristics of the tapered surface and the curved surface described in the first embodiment, but has a structure that does not positively abut. In the present embodiment, the plunger seal 103 is basically held by a radial reaction force caused by press-fitting the plunger seal 103 and the plunger seal holding portion 102. That is, the plunger seal protection part 103 and the plunger seal holding part 102 are held only by the radial pressing force.

  When the plunger 2 comes into contact with the plunger seal 103, the radial reaction force is small, and even when the plunger seal 103 moves, the structure is such that it stops at a fixed position by a tapered portion or a curved portion installed below. Therefore, it has the effect described in the first embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Pump housing, 2 ... Plunger, 8 ... Discharge valve mechanism, 9 ... Pressure pulsation reduction mechanism, 10c ... Suction passage, 11 ... Pressurization chamber, 12 ... Discharge passage, 20 ... Fuel tank, 23 ... Common rail, 24 ... Injector , 26 ... Pressure sensor, 30 ... Electromagnetic suction valve mechanism, 100 ... Plunger seal, 101 ... Plunger seal spring, 102 ... Plunger seal holding part, 102a ... Plunger seal holding part taper part, 102b ... Plunger seal holding part curved part, 103 ... Seal holder, 103a ... Seal holder taper part, 103b ... Seal holder curved part.

Claims (6)

A pressurizing chamber for pressurizing the fuel;
A plunger for increasing or decreasing the volume of the pressurizing chamber;
A plunger seal disposed on the outer periphery of the plunger for performing a fuel seal;
A plunger seal holding portion for holding the plunger seal;
A plunger seal protector that is disposed on the upper side in the axial direction with respect to the plunger seal and protects the plunger seal,
A high-pressure fuel pump characterized in that a taper surface or a curved surface is formed in the plunger seal protection part, and the axial position of the plunger seal protection part is determined by the taper surface or the curve surface. The high-pressure fuel pump according to claim 1,
A high-pressure fuel pump characterized in that a taper surface or a curved surface is formed in the plunger seal holding portion, and an axial position of the plunger seal protection portion is determined by the taper surface or the curved surface. The high-pressure fuel pump according to claim 1 or 2,
A high-pressure fuel pump configured to prevent the plunger seal protection portion and the plunger seal holding portion from contacting each other in the axial direction. The high-pressure fuel pump according to claim 1 or 2,
The high-pressure fuel pump, wherein the plunger seal protection part and the plunger seal holding part are held only by a radial pressing force. The high-pressure fuel pump according to claim 1,
The position of the plunger seal protection part in the axial direction is determined only by the tapered surface or the curved surface formed in the plunger seal protection part. The high-pressure fuel pump according to claim 2,
The high-pressure fuel pump, wherein an axial position of the plunger seal protection part is determined only by the tapered surface or the curved surface formed in the plunger seal holding part.

Images