JP2016044664A - Discharge valve mechanism of high pressure fuel supply pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To resolve a problem of increasing a fluid resistance to cause a pressurizing chamber fuel pressure to be increased even though the conventional ball valve structure has installed a regulation member for restricting a turbulence of a ball in a direction crossing at a right angle with a stroke axis line of the ball valve in order to resolve occurrence of abnormal wear at a seat part.SOLUTION: To cause an outer diameter part of a member facing against a seat side for restricting a displacement of a valve in a direction crossing at a right angle with a stroke axis line to have a tapered portion or C chamfer or R chamfer.EFFECT: In accordance with this invention having such a configuration as above, it is possible to reduce a fluid resistance at a discharging stage and restrict excessive rise of the pressurizing chamber.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a high-pressure fuel supply pump that supplies fuel to an engine at a high pressure, and more particularly to a discharge valve mechanism.

  For example, Japanese Patent No. 4650851 is a background art in this technical field. This publication discloses a valve body pressing seat.

Japanese Patent No. 4650851

  By the member that regulates the displacement in the direction intersecting the stroke axis of the valve, the pressurized chamber fuel pressure becomes higher than that of the ball valve structure not provided with the regulating member. Cavitation erosion occurs, resulting in a problem that airtightness is lowered.

  An object of the present invention is to ensure a sufficient fuel passage area with respect to the opening areas of the valve and the seat when the valve is opened.

  In the present invention, in order to achieve the above object, an escape portion is provided in the outer peripheral portion of the holder that guides the outer diameter of the valve, thereby securing a flow path area.

  According to the present invention configured as described above, an excessive increase in the fuel pressure in the high-pressure chamber can be suppressed even if a member for restricting the displacement in the direction intersecting the stroke axis of the valve is provided, and the differential pressure of the discharge valve is small. Therefore, the occurrence of cavitation erosion on the sheet surface can be reduced, so that airtightness can be secured.

1 is an example of a fuel supply system using a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. 1 is a longitudinal sectional view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. It is a longitudinal cross-sectional view of the high-pressure fuel supply pump by 1st Example with which this invention was implemented, and represents the longitudinal cross-section of a different angle from FIG. It is an enlarged view of the electromagnetically driven valve mechanism 30 of the high-pressure fuel supply pump according to the first embodiment in which the present invention is implemented, and shows a state in which the electromagnetic coil 52 is not energized. It is an enlarged view of the electromagnetically driven valve mechanism 30 of the high-pressure fuel supply pump according to the first embodiment in which the present invention is implemented, and shows a state where the electromagnetic coil 52 is energized. The state before incorporating the electromagnetically driven valve mechanism 30 of the high-pressure fuel supply pump according to the first embodiment in which the present invention is incorporated into the pump housing 1 is shown. The enlarged view in the valve-closing state of the discharge valve mechanism part of the high-pressure fuel supply pump by the 1st example with which the present invention was carried out is shown. The enlarged view in the valve opening state of the discharge valve mechanism part of the high-pressure fuel supply pump by the 1st Example by which this invention was implemented is shown. The state before incorporating in the pump housing of the plunger unit 80 of the high pressure fuel supply pump by 1st Example by which this invention was implemented is shown. The assembly method of the plunger unit 80 of the high-pressure fuel supply pump according to the first embodiment in which the present invention is implemented will be described. 1 is an external view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. 1 shows a partially enlarged view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. The exploded perspective view of a discharge valve unit.

  Embodiments of the present invention will be described below with reference to the drawings.

  The configuration of a high-pressure fuel pump that is an embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, a portion surrounded by a broken line indicates a pump housing 1 of the high-pressure pump, and mechanisms and components shown in the broken line indicate that they are integrated into the pump housing 1 of the high-pressure pump. .

  The fuel in the fuel tank 20 is pumped up by the feed pump 21 based on a signal from an engine control unit 27 (hereinafter referred to as ECU), pressurized to an appropriate feed pressure, and passed through the suction pipe 28 to the suction port 10a of the high-pressure fuel supply pump. Sent to. In this embodiment, the feed pressure is 0.4 MPa.

  The fuel that has passed through the suction port 10a passes through a filter 102 fixed in the suction joint 101, and further, an electromagnetically driven valve mechanism 30 that constitutes a variable capacity mechanism via the suction flow path 10b and the metal diaphragm dampers 9 and 10c. To the intake port 30a.

  The suction filter 102 in the suction joint 101 serves to prevent foreign matter existing between the fuel tank 20 and the suction port 10a from being absorbed into the high-pressure fuel supply pump by the flow of fuel.

  FIG. 4 is an enlarged view of the electromagnetically driven valve mechanism 30, and shows a non-energized state in which the electromagnetic coil 53 is not energized.

  FIG. 5 is an enlarged view of the electromagnetically driven valve mechanism 30, and shows a state in which the electromagnetic coil 53 is energized.

  The pump housing 1 is formed with a convex portion 1A as a pressurizing chamber 11 at the center, and a hole 30A for mounting the electromagnetically driven valve mechanism 30 is formed so as to open the pressurizing chamber 11.

  The plunger rod 31 is composed of three parts: a suction valve portion 31a, a rod portion 31b, and an anchor fixing portion 31c. An anchor 35 is welded and fixed to the anchor fixing portion 31c by a welding portion 37b.

  As shown in the figure, the spring 34 is fitted into the anchor inner periphery 35a and the first core portion inner periphery 33a, and a spring force is generated by the spring 34 in a direction in which the anchor 35 and the first core portion 33 are separated.

  The valve seat 32 includes a suction valve seat portion 32a, a suction passage portion 32b, a press-fit portion 32c, and a sliding portion 32d. The press-fit portion 32 c is press-fitted and fixed to the first core portion 33. The suction valve seat portion 32a is press-fitted and fixed to the pump housing 1, and the pressurization chamber 11 and the suction port 30a are completely blocked by this press-fit portion.

  The first core portion 33 is welded and fixed to the pump housing 1 by a welded portion 37c, and shuts off the suction port 30a and the outside of the high-pressure fuel supply pump.

  The 2nd core part 36 is being fixed to the 1st core part 33 by the welding part 37a, and has interrupted | blocked the internal space and external space of the 2nd core part 36 completely. The second core portion 36 is provided with a magnetic orifice portion 36a.

  When the electromagnetic coil 53 is not energized and is not energized, and when there is no fluid differential pressure between the suction channel 10c (suction port 30a) and the pressurizing chamber 11, the plunger rod 31 is As shown in FIG. 4, it moves to the right in the figure. In this state, the intake valve portion 31a and the intake valve seat portion 32a come into contact with each other and the intake port 38 is closed.

  When the plunger 2 is in the suction process state in which the plunger 2 is displaced downward in FIG. 2 due to the rotation of the cam described later, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. In this process, 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 portion 31a is provided with a valve opening force (suction valve portion 31a) due to the fluid differential pressure of the fuel. 1) is generated.

  By the valve opening force due to the fluid differential pressure, the suction valve portion 31a is set to open over the biasing force of the spring 34 and open the suction port 38. When the fluid differential pressure is large, the suction valve portion 31 a is completely opened and the anchor 35 is in contact with the first core portion 33. When the fluid differential pressure is small, the suction valve portion 31 a does not open completely, and the anchor 35 does not contact the first core portion 33.

  In this state, when a control signal from the ECU 27 is applied to the electromagnetically driven valve mechanism 30, a current flows through the electromagnetic coil 53 of the electromagnetically driven valve mechanism 30, and between the first core portion 33 and the anchor 35. Generate magnetic biasing forces that attract each other. As a result, a magnetic biasing force is applied to the plunger rod 31 to the left in the drawing.

  When the intake valve portion 31a is completely open, the valve open state is maintained. On the other hand, when the suction valve portion 31a is not fully opened, the suction valve portion 31a is fully opened by promoting the valve opening motion of the suction valve portion 31a, so that the anchor 35 is in contact with the first core portion 33, Then maintain that state.

  As a result, the state in which the suction valve portion 31a opens the suction port 38 is maintained, and fuel flows from the suction port 30a through the suction passage portion 32b of the valve seat 32 and the suction port 38 into the pressurizing chamber 11.

  When the plunger 2 finishes the suction process while maintaining the application state of the input voltage to the electromagnetically driven valve mechanism 30, and moves to the compression process in which the plunger 2 is displaced upward in FIG. 2, the magnetic biasing force is maintained. Therefore, the intake valve portion 31a is still open.

  Although the volume of the pressurizing chamber 11 decreases as the plunger 2 compresses, in this state, the fuel once sucked into the pressurizing chamber 11 passes through the suction port 38 in the valve-opened state again, and the suction flow path 10c (suction). Since the pressure is returned to the port 30a), the pressure in the pressurizing chamber does not increase. This process is called a return process.

  In this state, when the control signal from the ECU 27 is canceled and the electromagnetic coil 53 is de-energized, the magnetic biasing force acting on the plunger rod 31 is after a certain time (after magnetic and mechanical delay time). Erased. Since the urging force of the spring 34 is acting on the suction valve portion 31 a, the suction valve portion 31 a closes the suction port 38 with the urging force of the spring 34 when the electromagnetic force acting on the plunger rod 31 disappears. When the suction port 38 is closed, the fuel pressure in the pressurizing chamber 11 increases with the upward movement of the plunger 2 from this time. When the pressure of the fuel discharge port 12 or higher is reached, high pressure discharge of the fuel remaining in the pressurizing chamber 11 is performed via the discharge valve unit (discharge valve mechanism) 8 and supplied to the common rail 23. This process is called a discharge process. That is, the compression process of the plunger 2 (the ascending process from the lower start point to the upper start point) includes a return process and a discharge process.

  And the quantity of the high pressure fuel discharged can be controlled by controlling the timing which cancels | releases the electricity supply to the electromagnetic coil 53 of the electromagnetically driven valve mechanism 30. FIG.

  If the timing of releasing the energization of the electromagnetic coil 53 is advanced, during the compression process, the ratio of the return process is small and the ratio of the discharge process is large.

  That is, the amount of fuel returned to the suction channel 10c (suction port 30a) is small, and the amount of fuel discharged at high pressure is large.

  On the other hand, if the timing for releasing the input voltage is delayed, the ratio of the return process in the compression process is large and the ratio of the discharge process is small. That is, the amount of fuel returned to the suction passage 10c is large, and the amount of fuel discharged at high pressure is small. The timing for releasing the energization of the electromagnetic coil 53 is controlled by a command from the ECU.

  With the configuration as described above, the amount of fuel discharged at high pressure can be controlled to the amount required by the internal combustion engine by controlling the timing of releasing the energization of the electromagnetic coil 53.

  Thus, the necessary amount of fuel introduced to the fuel inlet 10a is pressurized to a high pressure by the reciprocating movement of the plunger 2 in the pressurizing chamber 11 of the pump housing 1 as the pump body, and the fuel discharge port 12 moves to the common rail 23. Pumped.

  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, open and close according to a control signal from an engine control unit (ECU) 27, and inject fuel into the cylinders.

  At this time, the suction valve portion 31a repeats the opening / closing motion of the suction port 38 as the plunger 2 descends and ascends, and the plunger rod 31 repeats the lateral movement in the drawing. At this time, the movement of the plunger rod 31 is limited to the movement in the horizontal direction in the drawing by the sliding portion 32d of the valve seat 32, and the sliding portion 32d and the rod portion 31b repeat the sliding motion. Therefore, the sliding portion needs to have a sufficiently low surface roughness so as not to be a resistance to the sliding movement of the plunger rod 31.

  In the present embodiment, the members constituting the magnetic circuit are an anchor 35, a first core portion 33, a yoke 51, and a second core portion 36 as shown in FIG. 5, and these are all magnetic materials.

  Although the first core portion 33 and the second core portion 36 are joined by welding by a welded portion 37a, the magnetic flux does not pass directly between the first core portion 33 and the second core portion 36, and the anchor 35 is interposed. Need to pass through. This is to generate a magnetic urging force between the first core portion 33 and the anchor 35, and the magnetic flux directly passes between the first core portion 33 and the second core portion 36, and the magnetic flux passes through the anchor. If this decreases, the magnetic biasing force will decrease.

  In the present embodiment, the first core portion 33 and the second core portion 36 are directly joined by the welded portion 37, and the magnetic orifice portion 36a is provided in the second core portion. In the magnetic orifice portion 36a, the thickness is made as thin as the strength allows, while the other portions of the second core portion 36 have a sufficient thickness. Further, the magnetic orifice portion 36a is provided in the vicinity of the portion where the first core portion and the anchor 35 are in contact with each other.

  As a result, most of the generated magnetic flux passes through the anchor 35, and the magnetic flux that passes directly through the first core portion 33 and the second core portion is very small, thereby being generated between the first core portion 33 and the anchor 35. The reduction of the magnetic urging force is within an allowable range.

  The magnetic coil 53 is formed by winding a lead wire 54 around the axis of the plunger rod 31. Both ends of the lead wire 54 are welded to the terminal 56 at lead wire welds 55. The terminal is a conductive substance and is open to the connector portion 58. When a mating connector from the ECU is connected to the connector portion 58, the terminal contacts the mating terminal and transmits current to the coil.

  In this embodiment, the lead wire welded portion 55 is disposed outside the yoke 51. Since the lead wire welded portion 55 is disposed outside the magnetic circuit, and the space required for the lead wire welded portion 55 is not provided, the entire length of the magnetic circuit can be shortened, and the first core portion 33 and the anchor 35 can be shortened. A sufficient magnetic biasing force can be generated.

  FIG. 6 shows a state before the electromagnetically driven valve mechanism 30 is assembled into the pump housing 1.

  In this embodiment, first, a unit is created for each of the intake valve unit 37 and the connector unit 39. Next, the suction valve seat portion 32a of the suction valve unit 37 is press-fitted and fixed to the pump housing 1, and then the welded portion 37c is welded over the entire circumference. In this embodiment, the welding is laser welding. In this state, the connector unit 39 is press-fitted and fixed to the first core portion 33. Thereby, the direction of the connector 58 can be freely selected.

  A convex portion 1A as a pressurizing chamber 11 is formed at the center of the pump housing 1, and a recess 11A for mounting a discharge valve unit (discharge valve mechanism) 8 is formed so as to open the pressurizing chamber 11. Has been.

  FIG. 7 shows an enlarged view of the discharge valve mechanism (valve closed state).

  FIG. 8 shows an enlarged view of the discharge valve mechanism (valve open state).

A discharge valve unit (discharge valve mechanism) 8 is provided at the outlet of the pressurizing chamber 11.
The discharge valve unit (discharge valve mechanism) 8 includes a valve seat member 8a, a spherical discharge valve member 8b that enables line contact, and a maximum diameter position 8b2 of the valve in a direction that intersects the valve stroke axis. The valve holding member 8c, the discharge valve spring 8d, the stopper of the valve holding member 8c, and the valve housing 8e having the functions of the sliding guide 8e3 are slidably surrounded.

  First, a spherical discharge valve member 8b, a holder material 8c, and a discharge valve spring 8d that are configured outside the pump housing 1 are assembled in the valve housing 8e, and a valve seat member 8a is press-fitted into the discharge valve unit (discharge valve unit). After assembling the mechanism 8, the discharge valve unit (discharge valve mechanism) 8 assembled from the left side in the drawing is press-fitted into the pump housing 1 and fixed by the press-fitting portion 8 a 1. When press-fitting, a stepped surface formed by a valve housing 8e as a stopper of the valve holding member 8c is used as a load receiving portion 8a2, and a mounting jig is pressed to the right side of the drawing to press-fit to the pump housing 1.

  When the in-cylinder pressure becomes high, the fluid action inside the discharge valve is intensified, and the discharge valve member 8b starts to run out in the direction intersecting the stroke axis, and is provided in the valve seat member 8a when the discharge valve member 8b is closed. The position where the sheet surface member 8a3 collides is indefinite, the sheet surface is abnormally worn, the airtightness is lowered, and the residual pressure performance cannot be ensured. For this purpose, a restriction member 8c1 is provided in order to prevent the discharge valve member 8b from moving in the direction intersecting the stroke axis when the discharge valve member 8b is opened and closed.

  Thereby, even when the valve holding member 8c is fully closed and fully opened, the maximum diameter position 8b2 of the discharge valve member 8b can be slidably surrounded by the regulating member 8c1 disposed on the valve holding member 8c. The trajectory of the discharge valve member 8b is regulated in a straight line in any discharge state depending on the operation state that changes from moment to moment, and the discharge valve member 8b is seated at a steady position of the seat surface portion 8a3, so that wear can be suppressed and airtightness is achieved. Is retained and the residual pressure performance can be secured.

  A valve housing discharge hole 8e1 of the valve housing 8d is provided on the side surface of the valve housing 8e, and a valve housing discharge hole 8e2 is also provided in the direction of the fuel discharge port 12. An annular fuel passage 8f formed between the facing surfaces of the valve seat member 8a and the valve holding member 8c is provided at a position facing the valve housing discharge hole 8e1. The passage area after the fuel exits the seat surface 8a3 can be ensured so that the passage area of the fuel passage is not obstructed in the middle of the opening direction of the valve and the seat portion, and the passage efficiency is expected to be improved. The passage diameter is not reduced by the valve holding member outer diameter taper 8c2 provided in the valve holding member 8c at the valve housing discharge hole 8e1, and therefore the maximum flow rate can be expected to be improved because it goes toward the discharge port 12. The valve holding member outer diameter taper 8c2 is installed so as not to interfere with the valve housing discharge hole 8e1 when the valve holding member 8c slides.

  The fastening of the seat member and the holder and the fastening of the discharge valve unit and the pump housing are performed by press fitting. At this time, the positions of the press-fitting positions are shifted as shown in the parts (a) and (b) so that the press-fitting positions do not overlap each other. This aims to prevent double press-fit structure and improve mass production management. With respect to the press-fitting position for fastening the sheet member and the holder, press-fitting is performed at a place away from the sheet position in consideration of layout constraints. Thus, the sheet member 8a is devised so as not to be deformed after press-fitting, and the specification is such that airtightness can be ensured.

  After the discharge valve unit (discharge valve mechanism) 8 is press-fitted and fixed to the pump housing 1, the joint 12 a is fixed to the pump housing 1. First, the joint 12a is press-fitted and fixed to the pump housing 1 at 12a1, and then 12a2 is fixed by laser welding. By using this embodiment, the layout can be more flexible than the case where the discharge valve is incorporated in the discharge joint 12a, so that it can be adapted to the layout of each engine and a special joint is prepared. Therefore, versatility can be improved.

  As shown in FIG. 7, a passage 8d2 is provided at the discharge-side tip of the valve holding member 8d. Therefore, when the discharge valve unit (discharge valve mechanism) 8 has no fuel differential pressure between the pressurizing chamber 11 and the discharge port 12, the discharge valve member 8b is urged by the discharge valve spring 8c to generate the valve seat member 8a. The seat surface portion 8a3 is in pressure contact and is in a seated state (valve closed state). The discharge valve member 8b resists the discharge valve spring 8c as shown in FIG. 8 only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure at the discharge port 12 by the discharge valve spring 8c. The fuel in the pressurizing chamber 11 is discharged to the common rail 23 through the discharge port 12. At this time, the fuel passes through the passage 8d1 provided in the valve holding member 8d and is pumped from the pressurizing chamber 11 to the discharge port 12. Thereafter, when the sum of the fuel pressure at the discharge port 12 and the valve opening pressure by the discharge valve spring 8 c becomes larger than the fuel pressure in the pressurizing chamber 11, the discharge valve member 8 b is closed as before. Thereby, it becomes possible to close the discharge valve member 8b after high-pressure fuel discharge.

  The valve opening pressure of the discharge valve member 8b is set to 0.1 MPa or less. As described above, the feed pressure is 0.4 MPa, and the discharge valve member 8b is opened by the feed pressure. As a result, even when it becomes impossible to pressurize the fuel to a high pressure due to a failure of the high-pressure fuel supply pump, the fuel is supplied to the common rail by the feed pressure, and the injector 24 can inject the fuel.

  When the discharge valve member 8b is opened, the discharge valve member 8b comes into contact with a stopper constituted by a small-diameter stepped portion 8d3 provided on the inner peripheral portion of the valve holding member 8d, and the operation is restricted. Therefore, the stroke of the discharge valve member 8b is appropriately determined by the stopper configured by the small diameter stepped portion 8d3 provided on the inner peripheral portion of the valve holding member 8d. If the stroke is too large, the fuel discharged to the fuel discharge port 12 will flow back into the pressurizing chamber 11 again due to the delay in closing the discharge valve member 8b. End up. In this embodiment, the stroke of the discharge valve spring 8c is set to 1.0 mm. Further, when the discharge valve member 8b repeats opening and closing movements, the discharge valve member 8b is guided by the peripheral surface without the valve holding member 8d so that the discharge valve member 8b moves only in the stroke direction.

  By configuring as described above, the discharge valve unit (discharge valve mechanism) 8 becomes a check valve that restricts the flow direction of fuel.

  If the valve holding member 8d is deformed, the pressurizing chamber 11 and the discharge port 12 cannot be blocked hydraulically, and the high-pressure fuel in the discharge port 12 flows back into the pressurizing chamber 11. Further, if the seat surface portion 8a3 of the valve seat member 8a is deformed, the fuel cannot be seated when the intake valve is closed, and the high-pressure fuel in the discharge port 12 also flows back into the pressurizing chamber 11. As a result, there is a problem that the efficiency of the high-pressure fuel supply pump is lowered.

  The outer periphery of the cylinder 6 is held by a cylindrical fitting portion 7 a of the cylinder holder 7. The cylinder 6 is fixed to the pump housing 1 by screwing a screw 7 g threaded on the outer periphery of the cylinder holder 7 into a screw 1 b threaded on the pump housing 1. The plunger seal 13 is held at the lower end of the cylinder holder 7 by a seal holder 15 and a cylinder holder 7 that are press-fitted and fixed to the inner peripheral cylindrical surface 7 c of the cylinder holder 7. At this time, the plunger seal 13 is held by the inner peripheral cylindrical surface 7c of the cylinder holder 7 so that its axis is coaxial with the axis of the cylindrical fitting portion 7a. The plunger 2 and the plunger seal 13 are installed in a slidable contact state at the lower end of the cylinder 6 in the figure.

  This prevents the fuel in the seal chamber 10f from flowing into the tappet 3 side, that is, the inside of the engine. At the same time, lubricating oil (including engine oil) for lubricating the sliding portion in the engine room is prevented from flowing into the pump housing 1.

  Further, the cylinder holder 7 is provided with an outer peripheral cylindrical surface 7b, in which a groove 7d for fitting the O-ring 61 is provided. The O-ring 61 shuts off the engine cam side and the outside by the inner wall of the engine-side fitting hole 70 and the groove 7d of the cylinder holder 7 and prevents engine oil from leaking outside.

  The cylinder 6 has a crimping part 6 a that intersects the reciprocating direction of the plunger 2, and the crimping part 6 a is crimped to the crimping surface 1 a of the pump housing 1. Crimping is performed by thrust generated by screw tightening. The pressurizing chamber 11 is formed by this pressure bonding, so that even if the fuel in the pressure chamber 11 is pressurized and becomes high pressure, the screw is not leaked from the pressure chamber 11 through the pressure bonding portion. Tightening torque must be managed.

  Moreover, in order to keep the sliding length of the plunger 2 and the cylinder 6 appropriate, it was set as the structure inserted in the pressurization chamber 11 deeply with the cylinder 6. FIG. A clearance 1 </ b> B is provided between the outer periphery of the cylinder 6 and the inner periphery of the pump housing 1 on the pressure chamber 11 side from the crimping portion 6 a of the cylinder 6. Since the outer periphery of the cylinder 6 is held by the cylindrical fitting portion 7a of the cylinder holder 7, the clearance 1B is provided so that the outer periphery of the cylinder 6 and the inner periphery of the pump housing 1 do not come into contact with each other. it can.

  As described above, the cylinder 6 holds the plunger 2 that moves forward and backward in the pressurizing chamber 11 so as to be slidable along the forward and backward movement direction.

  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. Thereby, the plunger 2 can be moved back and forth (reciprocated) up and down with the rotational movement of the cam 5.

  Here, the suction channel 10c is connected to the seal chamber 10f via the suction channel 10d and the suction channel 10e provided in the cylinder holder 7, and the seal chamber 10f is always connected to the pressure of the intake fuel. ing. When the fuel in the pressurizing chamber 11 is pressurized to a high pressure, a minute amount of high-pressure fuel flows into the seal chamber 10f through the sliding clearance between the cylinder 6 and the plunger 2, but the inflowed high-pressure fuel is released to the suction pressure. Therefore, the plunger seal 13 is not damaged by the high pressure.

  The plunger 2 includes a large-diameter portion 2 a that slides with the cylinder 6 and a small-diameter portion 2 b that slides with the plunger seal 13. The diameter of the large diameter portion 2a is set larger than the diameter of the small diameter portion 2b, and is set coaxially with each other. The sliding part with the cylinder 6 is the large diameter part 2a, and the sliding part with the plunger seal 13 is the small diameter part 2b. Thereby, since the joint part of the large diameter part 2a and the small diameter part 2b exists in the seal chamber 10f, the volume of the seal chamber 10f changes with the sliding movement of the plunger 2, and the fuel is sucked in accordingly. It moves between the seal chamber 10f and the suction channel 10c through the channel 10d and the suction channel 10s.

  FIG. 9 shows a state before the cylinder holder 7 is fixed to the pump housing 1 with screws.

  Plunger unit 80 is formed by plunger 2, cylinder 6, seal holder 15, plunger seal 13, cylinder holder 7, spring 4 and retainer 15.

  FIG. 10 shows a method for assembling the plunger unit 80.

  First, the plunger 2, the cylinder 6, the seal holder 15, and the plunger seal 13 are assembled into the cylinder holder 7 from the upper left in the figure. At that time, the seal holder 15 is press-fitted and fixed to the inner peripheral cylindrical surface 7 c of the cylinder holder 7. Thereafter, the spring 4 and the retainer 15 are assembled from the lower right in the figure. At that time, the retainer is press-fitted and fixed to the 15 plunger 2.

  The plunger unit 80 assembled in this manner is fastened and fixed to the pump housing 1 with screws after the O-ring 61 and the O-ring 62 are mounted. Tightening is performed by a hexagonal portion 7e formed in the cylinder holder 7. The hexagonal portion 7e has an inner hexagonal shape, and generates torque with a dedicated tool to tighten the screw. By managing this torque, the pressure contact pressure between the pressure bonding part 6a and the pressure bonding surface 1a is managed.

  The metal diaphragm damper 9 is composed of two metal diaphragms, and the outer periphery is fixed to each other by welding all around the welded portion in a state where gas is sealed in the space between the two diaphragms. When low pressure pressure pulsation is loaded on both surfaces of the metal diaphragm damper 9, the metal diaphragm damper 9 changes its volume, thereby reducing the low pressure pulsation.

  The high-pressure fuel supply pump is fixed to the engine by the mounting flange 41, the bolt 42, and the bush 43. The mounting flange 41 is welded to the pump housing 1 by a welded portion 41a so as to form an annular fixed portion. In this embodiment, laser welding is used.

  FIG. 11 is an external view of the mounting flange 41 and the bush 43. In this figure, only the mounting flange 41 and the bush 43 are shown, and other components are not shown.

  The two bushes 43 are attached to the attachment flange 41, and are attached to the opposite side of the engine. The two bolts 42 are screwed into respective screws formed on the engine side, and the two bushes 43 and the mounting flange 41 are pressed against the engine, thereby fixing the high-pressure fuel supply pump to the engine.

  FIG. 12 shows an enlarged view of the mounting flange 41, the bolt 42, and the bush 43 portion.

  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 mounting flange 41. Thereafter, the pump housing 1 and the welded portion 41a are welded in an annular shape by laser welding. Thereafter, the resin fastener 44 is inserted into the bush 43, and the bolt 42 is further inserted into the fastener 44. The fastener 44 serves to temporarily fix the bolt 42 to the bush 43. That is, the bolt 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 bolt 42 is screwed and fixed to a threaded portion provided on the engine side. At this time, the bolt 42 can be rotated in the bush 43 by the tightening torque of the bolt 42.

  In this embodiment, before the high pressure fuel supply pump is fixed to the engine, the bolt 42 is attached to the high pressure fuel supply pump and a drop-off prevention mechanism is provided, but when the bolt 42 is attached at the time of attachment to the engine, The fastener 44 is not particularly necessary.

DESCRIPTION OF SYMBOLS 1 Pump housing 1A Convex part 1B Clearance 1a Crimp surface 1b Screw 1d Conical surface 2 Plunger 2a Large diameter part 2b Small diameter part 3 Tappet 4 Spring 5 Cam 6 Cylinder 6a Crimp part 7 Cylinder holder 7a Cylindrical fitting part 7b Outer cylindrical surface 7c In Cylindrical cylindrical surface 7d Groove 7e Hexagonal section 8 Discharge valve unit (Discharge valve mechanism)
8a Valve seat member
8a1 Press-fit portion 8a2 Load receiving portion 8a3 Seat surface portion 8b Discharge valve member 8b2 Maximum diameter position 8c Valve holding member 8c1 Restricting member
8c2 Valve holding member outer diameter taper 8d Discharge valve spring 8e Valve housing 8e1 Valve housing discharge hole 8e2 Valve housing discharge hole 8f Annular fuel passage 9 Metal diaphragm damper 10a Inlet
10a Fuel inlet 10b Suction channel 10c Metal diaphragm damper 10c Suction channel 10d Suction channel 10e Suction channel 10f Seal chamber 10s Suction channel 11 Pressurizing chamber 11A Pressurizing chamber recess
11A Pressurization chamber discharge passage
11B annular projection 11C metal cylindrical member 12 fuel discharge port 12a discharge joint
12a1 Discharge joint press-fitting part 13 Plunger seal 15 Seal holder
16 Retainer
20 Fuel tank 21 Field pump 23 Common rail 24 Injector 26 Pressure sensor 27 ECU
28 Suction piping 30 Electromagnetically driven valve mechanism 30A Electromagnetically driven valve mechanism mounting hole 30a Suction port 31 Plunger rod 31a Suction valve portion 31b Rod portion 31c Anchor fixing portion 32 Valve seat 32a Suction valve seat portion 32b Suction passage portion 32c Press fit Part 32d Sliding part 33 First core part 33a First core part inner periphery 34 Spring 35 Anchor 35a Anchor inner periphery 36 Second core part 36a Magnetic orifice part 37 Suction valve unit
37a welded portion 37b welded portion 37c welded portion 38 inlet
39 Connector unit
41 Mounting flange 41a Welding part 42 Bolt 43 Bushing 43a Claw part 43b Caulking part 44 Fastener 51 Yoke 52 Electromagnetic coil 53 Electromagnetic coil 54 Lead wire 55 Lead wire welding part 56 Terminal 58 Connector part 61 O ring 62 O ring 70 Fitting hole 80 Plunger unit 101 Suction joint 101A Metal cylindrical member 102 Suction filter

Claims (5)

A sheet member having a sheet surface;
A valve annularly contacting the seat surface;
A valve holder provided with a regulating member that regulates the displacement of the valve in a direction intersecting the opening and closing direction of the valve;
An elastic body for biasing the valve in the closing direction via the valve holder;
In the valve mechanism having the seat member, the valve, the valve holder, and a holder for holding the elastic body,
Tapered on the seat member side of the valve holder, or C chamfer, R chamfer,
And valve mechanism that can regulate the displacement of the valve
The sliding surface of the valve holder is
Hold the seat member, valve, valve holder, elastic body,
Of a holder having a discharge hole for discharging a fluid;
Making it possible to maintain the discharge hole opening area of the holder,
The valve holder has a taper, C chamfering or R chamfering and can control the valve displacement.
The discharge hole of the holder is provided on a side surface of the holder, and the discharge hole is set at a position facing a fluid passage formed between leading ends of the holder and the sheet member facing each other. The valve mechanism according to claim 2.
The opening area of the discharge hole of the holder is
For the circumferential opening area of the air gap formed between the valve holder and the axial direction of the seat member,
Tapered on the seat member side of the valve holder so as to be equal to or greater than, C chamfering, R chamfering
And valve mechanism that can regulate the displacement of the valve
5. A high-pressure fuel supply pump comprising the valve mechanism according to claim 1 as a discharge valve.