JP2014114722A - High-pressure pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure pump which can enhance the suction efficiency of fuel to a pump chamber in which the fuel is pressurized.SOLUTION: The high-pressure pump comprises a suction valve 41 which can be seated on and removed from a valve seat 70 of an introduction passage, and a stopper 50 for limiting the movement of the suction valve 41 in a valve opening direction. The suction valve 41 has a valve body 42 abutting on the valve seat 70 and a cylindrical first guide part 43. The stopper 50 has a cylindrical second guide part 56 which slide-contacts with an external wall of the first guide part 43 of the suction valve 41, and an abutting part 54 abutting on the valve body 42. A valve chamber 44 is formed between the first guide part 43 of the suction valve 41 and the second guide part 56 of the stopper 50. An orifice 70 formed in a position in which the first guide part 43 and the second guide part 56 are overlapped on each other at the valve opening of the suction valve 41 makes the valve chamber 44 and the pump chamber 12 communicate with each other. By this, at the valve opening of the suction valve 41, the fuel of the valve chamber 44 flows to the pump chamber 12 through the orifice 70.

Description

  The present invention relates to a high pressure pump.

Conventionally, a high-pressure pump that is provided in a fuel supply system that supplies fuel to an internal combustion engine and pressurizes the fuel is known. The high-pressure pump sucks and pressurizes fuel from the introduction passage into the pump chamber by a plunger that reciprocates by the rotation of the camshaft of the internal combustion engine, and discharges the pressurized fuel.
The high-pressure pump described in Patent Document 1 is provided with a bottomed cylindrical suction valve in the introduction passage, and a protrusion protruding from a stopper contact surface that defines the lift amount of the suction valve is inserted inside the suction valve. Has been. The convex portion of the stopper guides the movement when the intake valve is opened and closed.

JP 2012-082809 A

However, the high-pressure pump described in Patent Document 1 has a structure in which the fuel in the valve chamber formed between the inner wall of the intake valve and the convex portion of the stopper is not easily discharged to the outside of the intake valve. For this reason, when the intake valve is opened, the fuel in the valve chamber becomes fluid resistance, and if the opening operation of the intake valve is delayed, the amount of fuel sucked from the introduction passage into the pump chamber, that is, the suction efficiency is lowered. Therefore, when the camshaft of the internal combustion engine rotates at a high speed and the reciprocating speed of the plunger increases, there is a problem that the fuel discharge amount of the high-pressure pump decreases.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-pressure pump capable of increasing the efficiency of sucking fuel into a pump chamber in which the fuel is pressurized.

The present invention relates to a high-pressure pump having a valve chamber between a first guide portion of a suction valve and a second guide portion of a stopper, and an orifice that communicates the pump chamber to which the fuel is pressurized and the valve chamber. The first guide part and the second guide part are provided at a position where the first guide part and the second guide part overlap when the valve is opened.
Thus, when the high-pressure pump shifts from the discharge stroke to the suction stroke, the fuel in the valve chamber flows through the orifice to the pump chamber. Therefore, the fuel in the valve chamber does not hinder the movement of the suction valve, so that the suction valve opens quickly. Therefore, the fuel suction efficiency from the introduction passage to the pump chamber can be increased.
In addition, by providing an orifice at a position where the first guide portion and the second guide portion overlap when the intake valve is opened, the opening cross-sectional area of the orifice can be changed when the intake valve is opened and closed. become. If the opening cross-sectional area when the intake valve is opened is made smaller than the opening cross-sectional area when the intake valve is closed, it will try to flow from the pump chamber through the orifice into the valve chamber during the metering stroke of the high-pressure pump. Less fuel. Therefore, an increase in the fuel pressure in the valve chamber is suppressed, and it is possible to increase the rotation speed at which a phenomenon (self-closing) occurs in which the intake valve is closed by the fuel pressure in the valve chamber. Therefore, the fuel discharge amount of the high-pressure pump can be reliably controlled at the time of high rotation of the internal combustion engine in which the reciprocating speed of the plunger of the high-pressure pump is increased.

It is sectional drawing of the high pressure pump by 1st Embodiment of this invention. FIG. 2 is a cross-sectional view showing a closed state of an intake valve in an enlarged view of a portion II in FIG. 1. FIG. 2 is a cross-sectional view showing an open state of an intake valve in an enlarged view of a portion II in FIG. 1. (A) is a graph showing the relationship between the fuel discharge amount of the high-pressure pump and the orifice area, and (B) is a graph showing the relationship between the self-closing limit rotational speed of the intake valve and the orifice area. It is a graph which shows the change of the orifice opening area at the time of valve opening of a suction valve and valve closing. It is sectional drawing which shows the valve closing state of the suction valve of the high pressure pump by 2nd Embodiment. It is sectional drawing which shows the valve opening state of the suction valve of the high pressure pump by 2nd Embodiment. It is sectional drawing which shows the valve closing state of the suction valve of the high pressure pump by 3rd Embodiment. It is sectional drawing which shows the valve opening state of the suction valve of the high pressure pump by 3rd Embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
(First embodiment)
A first embodiment of the present invention is shown in FIGS. The high-pressure pump 1 of this embodiment is provided in a fuel supply system that supplies fuel to an internal combustion engine. The fuel pumped up from the fuel tank is pressurized by the high-pressure pump 1 and accumulated in the delivery pipe. The fuel is injected and supplied to each cylinder of the internal combustion engine from an injector connected to the delivery pipe.

(Configuration of high-pressure pump)
As shown in FIG. 1, the high-pressure pump 1 includes a pump body 10, a plunger 20, a damper chamber 30, an electromagnetic valve unit 40, a discharge valve unit 90, and the like.
The pump body 10 is provided with a cylindrical cylinder 11. A plunger 20 is accommodated in the cylinder 11 so as to be capable of reciprocating in the axial direction. A spring 24 is provided between a spring seat 21 provided at an end of the plunger 20 protruding from the pump body 10 and an oil seal holder 23 that holds an oil seal 22 on the outer periphery of the plunger 20. By this spring 24, the plunger 20 is biased toward the camshaft side of the engine (not shown). Therefore, the plunger 20 reciprocates in the axial direction according to the cam profile of the camshaft. As the volume of the pump chamber 12 changes due to the reciprocating movement of the plunger 20, the fuel is sucked and pressurized.

Next, the damper chamber 30 will be described.
The pump body 10 is provided with a cylindrical cylindrical portion 31 that protrudes on the opposite side of the cylinder 11. The damper chamber 30 is formed by covering the cylindrical portion 31 with the bottomed cylindrical cover 32.
In the damper chamber 30, a pulsation damper 33, a support member 34, and a wave spring 35 are accommodated.
The pulsation damper 33 is composed of two metal diaphragms, and a gas having a predetermined pressure is sealed therein. The pulsation damper 33 reduces the fuel pressure pulsation in the damper chamber 30 by elastically deforming the two metal diaphragms according to the pressure change in the damper chamber 30.

  The damper chamber 30 communicates with a fuel inlet (not shown) through a fuel passage (not shown). Fuel is supplied to the fuel inlet from a fuel tank (not shown). Therefore, the damper chamber 30 is supplied with fuel from the fuel tank from the fuel inlet.

Next, the electromagnetic valve unit 40 will be described.
The electromagnetic valve unit 40 is provided in the introduction passage 13 that connects the pump chamber 12 and the damper chamber 30, and controls the opening and closing of the introduction passage 13. The electromagnetic valve unit 40 includes a suction valve 41, a stopper 50, an electromagnetic driving unit 80, and the like.
The pump body 10 is provided with a recess 14 substantially perpendicular to the central axis of the cylinder 11. The core housing 15 covers the opening of the recess 14, so that the introduction passage 13 from the damper chamber 30 to the pump chamber 12 is defined.

As shown in FIGS. 2 and 3, the cylindrical member 60, the valve seat member 61, the suction valve 41 and the stopper 50 are provided in the introduction passage 13 from the core housing 15 side toward the pump chamber 12 in this order. .
The stopper 50 has a bottomed cylindrical cup portion 51 and an outer edge portion 52 extending radially outward from the opening end of the cup portion 51 on the valve seat member side. In the stopper 50, the outer edge 52 abuts on the step 17 provided in the introduction passage 13. Further, a plurality of passages 53 communicating with the plate thickness direction are formed in the outer edge portion 52 of the stopper 50 in the circumferential direction.

The valve seat member 61 is formed in a cylindrical shape and has an annular valve seat 62 on the stopper side. The valve seat member 61 has a curved portion 63 that is recessed on the opposite side of the intake valve 41 on the outside of the valve seat 62.
Since the cylindrical member 60 is provided on the inner wall of the introduction passage 13, the cylindrical member 60 is screwed into the screw 141. By screwing the cylindrical member 60 into the female screw 141, the valve seat member 61 and the stopper 50 are pressed against the step 17 of the pump body 10 and fixed to the pump body 10.

The intake valve 41 includes a disk-shaped valve main body 42 and a cylindrical first guide portion 43 extending from the valve main body 42 to the opposite side of the valve seat 62. The valve main body 42 of the intake valve 41 can be seated and separated from the valve seat 62 of the valve seat member 61. The introduction passage 13 and the pump chamber 12 are closed when the suction valve 41 is seated on the valve seat 62, and the introduction passage 13 and the pump chamber 12 are communicated when the suction valve 41 is separated from the valve seat 62.
The valve body 42 of the suction valve 41 abuts the abutment portion 54 provided at the opening end of the cup portion 51 of the stopper 50 on the opposite surface of the valve seat 62. Thereby, the suction valve 41 is restricted from moving in the valve opening direction. The contact portion 54 of the stopper 50 is provided with one or a plurality of radially extending grooves 55 in the circumferential direction.

The outer peripheral surface of the first guide portion 43 of the suction valve 41 is in sliding contact with the inner peripheral surface of the cylindrical second guide portion 56 constituting the cup portion 51 of the stopper 50. The suction valve 41 is prevented from falling off or tilting from the valve seat 62 by the first guide portion 43 being guided by the second guide portion 56 of the stopper 50, so that the valve seat 62 can be securely seated or separated. It becomes possible to do.
When the suction valve 41 and the stopper 50 come into contact with each other, fuel flows from the pump chamber 12 through the groove 55 of the stopper 50 into the gap between the first guide portion 43 of the suction valve 41 and the second guide portion 56 of the stopper 50.

A valve chamber 44 is formed between the suction valve 41 and the stopper 50. A first spring 45 is provided in the valve chamber 44. The first spring 45 urges the suction valve 41 toward the valve seat.
The first guide portion 43 of the intake valve 41 is provided with an orifice 70 that communicates in the radial direction. The orifice 70 communicates the valve chamber 44 and the pump chamber 12. The pump chamber 12 refers to a space in which fuel is pressurized on the cylinder side with respect to the valve seat 62.

The orifice 70 is provided so as to include a portion of the first guide portion 43 that overlaps the second guide portion 56 when the intake valve 41 is opened and does not overlap the second guide portion 56 when the intake valve 41 is closed. Therefore, the orifice 70 has a large area overlapping the second guide part 56 when the intake valve 41 is opened, and a small area overlapping the second guide part 56 when the intake valve 41 is closed. Therefore, the opening sectional area of the orifice 70 when the suction valve 41 is opened is smaller than the opening sectional area of the orifice 70 when the suction valve 41 is closed.
The hole diameter of the orifice 70 is larger than the lift amount of the suction valve 41. Therefore, when the intake valve 41 is opened and closed, the opening cross-sectional area of the orifice 70 varies greatly depending on the lift of the intake valve 41.

The electromagnetic drive unit 80 will be described.
As shown in FIG. 1, a needle guide 16 is fixed inside the core housing 15. The needle guide 16 supports the needle 81 so as to be movable in the axial direction.
One end of the needle 81 is fixed to the movable core 82, and the other end can contact the suction valve 41.
The needle 81 is provided with a locking portion 83 extending radially outward from its outer wall. A second spring 84 is provided between the locking portion 83 and the needle guide 16. The second spring 84 urges the needle 81 toward the pump chamber with a stronger force than the first spring 45.

The movable core 82 is made of a magnetic material and is accommodated in a movable core chamber 85 provided inside the core housing 15. The movable core 82 can reciprocate in the axial direction.
The fixed core 86 is made of a magnetic material, and is provided with a core housing 15 and an annular portion 87 made of a nonmagnetic material interposed therebetween.
A connector 88 is provided outside the diameter of the fixed core 86. The connector 88 is held by a bottomed cylindrical yoke 881. A coil 89 is wound around a bobbin 882 provided inside the connector 88. When the coil 89 is energized through the terminal 883 of the connector 88, the coil 89 generates a magnetic field.

When the coil 89 is not energized, the movable core 82 and the fixed core 86 are separated from each other by the elastic force of the second spring 84. The needle 81 moves to the pump chamber 12 side, and the end surface of the needle 81 presses the suction valve 41.
When the coil 89 is energized, a magnetic flux flows through a magnetic circuit formed by the fixed core 86, the movable core 82, the yoke 881, and the core housing 15, and the movable core 82 resists the elastic force of the second spring 84, thereby fixing the fixed core. Magnetically attracted to the 86 side. As a result, the needle 81 releases the pressing force on the suction valve 41.

Next, the discharge valve unit 90 will be described.
The discharge valve portion 90 is composed of a discharge valve 91, a regulating member 92, a spring 93, and the like.
A discharge passage 94 is formed in the pump body 10 substantially perpendicular to the central axis of the cylinder 11. The discharge valve 91 is accommodated in the discharge passage 94 so as to be reciprocally movable. The discharge valve 91 opens and closes the discharge passage 94 by being seated on or separated from the valve seat 95.
The restricting member 92 provided on the fuel discharge port 96 side of the discharge valve 91 restricts the movement of the discharge valve 91 toward the fuel discharge port 96.
One end of the spring 93 abuts on the regulating member 92 and the other end abuts on the discharge valve 91 to urge the discharge valve 91 toward the valve seat.

When the pressure of the fuel in the pump chamber 12 rises and the force received by the discharge valve 91 from the fuel on the pump chamber side becomes larger than the sum of the elastic force of the spring 93 and the force received from the fuel on the downstream side of the valve seat 95, the discharge The valve 91 is separated from the valve seat 95. As a result, fuel is discharged from the fuel discharge port 96.
On the other hand, when the pressure of the fuel in the pump chamber 12 decreases and the force received by the discharge valve 91 from the fuel on the pump chamber side becomes smaller than the sum of the elastic force of the spring 93 and the force received from the fuel on the downstream side of the valve seat 95. The discharge valve 91 is seated on the valve seat 95. As a result, the fuel on the downstream side of the valve seat 95 is prevented from flowing back to the pump chamber 12.

(High pressure pump operation)
Next, the operation of the high pressure pump 1 will be described.
(1) Suction stroke When the plunger 20 descends from the top dead center toward the bottom dead center due to the rotation of the camshaft, the volume of the pump chamber 12 increases and the fuel is depressurized. The discharge valve 91 is seated on the valve seat 95 and closes the discharge passage 94.
On the other hand, the suction valve 41 moves to the stopper side against the urging force of the first spring 45 due to the pressure difference between the pump chamber 12 and the introduction passage 13, and is opened. That is, the state of FIG. 2 is shifted to the state of FIG. When the suction valve 41 moves to the stopper side, the fuel in the valve chamber 44 flows through the orifice 70 to the pump chamber 12.
In addition, since energization to the coil 89 is stopped from the middle of the discharge stroke, which is the previous stroke of the suction stroke, the needle 81 integrated with the movable core 82 is pumped by the urging force of the second spring 84 in the suction stroke. The suction valve 41 is pushed to the pump chamber side.
By opening the intake valve 41, fuel is sucked into the pump chamber 12 from the damper chamber 30 via the introduction passage 13.

(2) Metering stroke When the plunger 20 rises from the bottom dead center toward the top dead center due to the rotation of the camshaft, the volume of the pump chamber 12 decreases. At this time, since the energization to the coil 89 is stopped until a predetermined time, the needle 81 presses the suction valve 41 toward the pump chamber by the urging force of the second spring 84, and the suction valve 41 is in the open state. maintain.
By opening the intake valve 41, the pump chamber 12 and the introduction passage 13 are maintained in communication with each other. For this reason, the low-pressure fuel once sucked into the pump chamber 12 is returned to the damper chamber 30 via the introduction passage 13. Therefore, the pressure in the pump chamber 12 does not increase.
At this time, as shown in FIG. 3, most of the opening of the orifice 70 overlaps with the second guide portion 56 of the stopper 50. Thereby, the orifice 70 regulates the flow of fuel from the pump chamber 12 to the valve chamber 44. Therefore, an increase in the fuel pressure in the valve chamber 44 is suppressed, and the self-closing force generated by the fuel pressure in the valve chamber 44 acting on the intake valve 41 is small.

(3) Discharge stroke The coil 89 is energized at a predetermined time while the plunger 20 rises from the bottom dead center toward the top dead center. Then, a magnetic attractive force is generated between the fixed core 86 and the movable core 82 by the magnetic field generated in the coil 89. When this magnetic attractive force becomes larger than the difference between the elastic force of the second spring 84 and the elastic force of the first spring 45, the movable core 82 and the needle 81 move to the fixed core side. Thereby, the pressing force of the needle 81 against the suction valve 41 is released. The suction valve 41 is moved to the valve seat side by the elastic force of the first spring 45 and the force generated by the flow of the low-pressure fuel discharged from the pump chamber 12 to the damper chamber side, and is closed. That is, the state of FIG. 3 is shifted to the state of FIG. When the suction valve 41 moves to the valve seat side, the fuel in the pump chamber 12 passes through the groove 55 of the stopper 50, the gap between the first guide portion 43 and the second guide portion 56, and the orifice 70 to the valve chamber 44. Inflow.

Since the intake valve 41 is closed, the fuel pressure in the pump chamber 12 increases as the plunger 20 rises. When the force of the fuel pressure in the pump chamber 12 acting on the discharge valve 91 becomes larger than the force of the fuel pressure in the discharge passage 94 acting on the discharge valve 91 and the biasing force of the spring 93, the discharge valve 91 opens. As a result, the high-pressure fuel pressurized in the pump chamber 12 is discharged from the fuel discharge port 96 via the discharge passage 94.
Note that energization of the coil 89 is stopped during the discharge stroke. Since the force that the fuel pressure in the pump chamber 12 acts on the suction valve 41 is larger than the biasing force of the second spring 84, the suction valve 41 maintains the closed state.
The high-pressure pump 1 repeats steps (1) to (3) to pressurize and discharge a necessary amount of fuel to the internal combustion engine.

(Examination on orifice)
4A and 4B show the discharge amount characteristic and the self-closing limit characteristic when an orifice having various hole diameters is provided at the bottom of the cup portion 51 of the stopper 50 and the high-pressure pump 1 is driven. .
4A shows the relationship between the opening cross-sectional area of the orifice and the fuel discharge amount of the high-pressure pump, and FIG. 4B shows the rotation speed of the pump (self-closing) where the opening cross-sectional area of the orifice and the suction valve are self-closing. (Restricted speed).
Note that the fuel discharge amount in FIG. 4 (A) is a state in which all the fuel is discharged without the metering process.

  Referring to FIG. 4A, when the orifice cross-sectional area is large, the fuel discharge amount increases, and when the orifice cross-sectional area is small, the fuel discharge amount decreases. This is because if the opening cross-sectional area of the orifice is large, the opening responsiveness of the suction valve 41 is improved during the suction stroke of the high-pressure pump, and the suction efficiency is increased, thereby increasing the fuel discharge amount of the high-pressure pump. . Therefore, from the viewpoint of the fuel discharge amount, it is preferable that the opening cross-sectional area of the orifice is in the region of the hatched portion α in FIG.

On the other hand, referring to FIG. 4B, when the opening cross-sectional area of the orifice is small, the self-closing limit rotational speed is high, and when the orifice cross-sectional area is large, the self-closing limit rotational speed is low. This is because if the opening cross-sectional area of the orifice is small, an increase in the fuel pressure in the valve chamber 44 is suppressed during the metering stroke of the high-pressure pump, and the self-closing force of the intake valve is reduced. Therefore, from the viewpoint of the self-closing limit rotational speed, it is preferable that the opening cross-sectional area of the orifice is in the area of the shaded portion β in FIG.
4A and 4B, when the orifice cross-sectional area is constant, as shown by an arrow X, the opening cut-off that allows both the fuel discharge amount and the self-closing limit rotational speed to be advantageous conditions. There is no area.

Next, FIG. 5A shows the orifice opening cross-sectional area-suction valve lift amount characteristic when the orifice 70 is provided in the first guide portion 43 of the suction valve 41.
Here, as described above, the hole diameter of the orifice is set larger than the valve lift of the suction valve.

  In FIG. 5 (B), the opening cross-sectional area of the orifice is indicated by diagonal lines when the intake valve is closed and opened. That is, the opening cross-sectional area of the orifice is large when the intake valve 41 is closed and is small when the valve is opened.

  As shown in FIG. 5A, when the intake valve is closed, the opening cross-sectional area of the orifice is in the region of the hatched portion α that increases the fuel discharge amount. In addition, when the intake valve is opened, the opening cross-sectional area of the orifice is in the region of the shaded portion β that increases the self-closing limit rotational speed. That is, when an orifice is provided in the first guide portion 43 of the intake valve, the orifice has a hatched portion α region in which the fuel discharge amount can be increased and a hatched portion in which the self-closing limit rotational speed can be increased. Both conditions of the region β can be satisfied.

(Operational effects of the first embodiment)
The first embodiment has the following operational effects.
(1) In the first embodiment, the orifice 70 is provided so as to include a position of the first guide portion 43 of the suction valve 41 that overlaps the second guide portion 56 when the suction valve 41 is opened. Thereby, the opening cross-sectional area of the orifice 70 is large when the intake valve 41 is closed, and is small when the valve is opened.
Since the opening cross-sectional area of the orifice 70 is large when the suction valve 41 is closed, the fuel in the valve chamber 44 flows into the pump chamber 12 when the high-pressure pump shifts from the discharge stroke to the suction stroke, and the valve opening operation of the suction valve 41 is performed. Become good. Therefore, the fuel suction efficiency from the introduction passage 13 to the pump chamber 12 can be increased.
Further, since the opening cross-sectional area of the orifice 70 is small when the intake valve 41 is opened, an increase in fuel pressure in the valve chamber 44 is suppressed during the metering stroke of the high-pressure pump, and the self-closing limit rotational speed of the intake valve 41 is reduced. Rise. Therefore, the fuel discharge amount of the high-pressure pump 1 can be reliably controlled at the time of high rotation of the internal combustion engine in which the reciprocating speed of the plunger is increased.
Furthermore, since the opening cross-sectional area of the orifice 70 is small when the intake valve 41 is opened, an increase in the fuel pressure in the valve chamber 44 is suppressed during the metering stroke of the high-pressure pump. The load on the spring 84 can be reduced. For this reason, it is possible to reduce the power supplied to the electromagnetic drive unit 80 when shifting from the metering stroke to the discharge stroke. Therefore, the high pressure pump 1 can be reduced in size and the power consumption of the high pressure pump 1 can be reduced.

(2) In the first embodiment, the hole diameter of the orifice 70 is larger than the lift amount of the suction valve 41. Thereby, the amount of change in the opening cross-sectional area of the orifice 70 due to the movement of the suction valve 41 can be increased.

(3) In the first embodiment, when moving from the discharge stroke to the suction stroke, the orifice 70 causes fuel to flow from the valve chamber 44 to the pump chamber 12 as the suction valve 41 moves in the valve opening direction. Thereby, the suction efficiency of the fuel from the introduction passage 13 to the pump chamber 12 can be increased, and the fuel discharge amount of the high-pressure pump can be increased.

(4) In the first embodiment, the orifice 70 regulates the flow of fuel from the pump chamber 12 to the valve chamber 44 during the metering stroke. Thereby, the self-closing limit rotation speed of the suction valve 41 can be increased, and the fuel discharge amount of the high-pressure pump at the time of high rotation can be reliably controlled.

(5) In the first embodiment, when shifting from the metering stroke to the discharge stroke, the orifice 70 causes fuel to flow from the pump chamber 12 to the valve chamber 44 as the suction valve 41 moves in the valve closing direction. As a result, the intake valve 41 can be quickly closed, and the fuel discharge amount of the high-pressure pump can be reliably controlled.

(Second Embodiment)
A second embodiment of the present invention is shown in FIGS. Hereinafter, in a plurality of embodiments, the same numerals are given to the composition substantially the same as a 1st embodiment mentioned above, and explanation is omitted.
In the second embodiment, the orifice 71 of the second guide portion 56 of the stopper 50 overlaps with the first guide portion 43 of the suction valve 41 when the suction valve 41 is opened, and the first guide portion when the suction valve 41 is closed. 43 is provided including a portion that does not overlap with 43. Also in this configuration, the orifice 71 has a large area overlapping the first guide portion 43 when the intake valve 41 is opened, and a small area overlapping the first guide portion 43 when the intake valve 41 is closed. Therefore, the opening sectional area of the orifice 71 when the suction valve 41 is opened is smaller than the opening sectional area of the orifice 71 when the suction valve 41 is closed.
Also in 2nd Embodiment, there can exist the same effect as 1st Embodiment.

(Third embodiment)
A third embodiment of the present invention is shown in FIGS.
In the third embodiment, the suction valve 46 has a bottomed cylindrical hat portion 47 and an annular portion 48 that extends in an annular shape radially outward from the stopper-side opening end of the hat portion 47. The annular portion 48 can be seated on and separated from the valve seat 62 of the valve seat member 65.
The stopper 57 has a disk part 58 and a protrusion 59 protruding from the disk part 58 toward the needle side. The stopper 57 is fixed to a step 66 provided with a disc portion 58 on the valve seat member 65. The disk portion 58 of the stopper 57 is formed with a plurality of passages 581 that communicate with the plate thickness direction in the circumferential direction.
A contact portion 49 provided at an opening end on the stopper side of the hat portion 47 of the suction valve 46 contacts the disk portion 58 of the stopper 57. Thereby, the suction valve 46 is restricted from moving in the valve opening direction. The contact portion 49 of the suction valve 46 is provided with one or more grooves 491 extending in the radial direction in the circumferential direction.

The protrusion 59 of the stopper 57 is inserted inside the hat portion 47 of the intake valve 46. The outer peripheral surface of the protrusion 59 of the stopper 57 is in sliding contact with the inner peripheral surface of the hat portion 47 of the suction valve 46. The suction valve 46 is prevented from falling off or tilting from the valve seat 62 by the inner peripheral surface of the hat portion 47 being guided by the protrusion 59 of the stopper 57, and can be seated securely on the valve seat 62. become.
In the third embodiment, the protrusion 59 of the stopper 57 corresponds to a “second guide portion” recited in the claims.

  The protrusion 59 of the stopper 57 is provided with a hole 72 that is recessed in the axial direction and an orifice 73 that communicates from the hole 72 in the radial direction. The hole 72 and the orifice 73 communicate the valve chamber 44 and the pump chamber 12. The orifice 73 has a large area overlapping the hat portion 47 when the suction valve 46 is opened, and a small area overlapping the hat portion 47 when the suction valve 46 is closed. Accordingly, the opening sectional area of the orifice 73 when the suction valve 46 is opened is smaller than the opening sectional area of the orifice 73 when the suction valve 46 is closed.

During the suction stroke of the high pressure pump, the suction valve 46 shifts from the state of FIG. 8 to the state of FIG. At this time, the fuel in the valve chamber 44 flows to the pump chamber 12 through the hole 72 and the orifice 73.
During the metering stroke of the high-pressure pump, the suction valve 46 maintains the state shown in FIG. At this time, the orifice 73 has a small opening cross-sectional area and restricts the flow of fuel from the pump chamber 12 to the valve chamber 44. Therefore, an increase in the fuel pressure in the valve chamber 44 is suppressed.
During the discharge stroke of the high-pressure pump, the suction valve 46 shifts from the state of FIG. 9 to the state of FIG. When the suction valve 46 moves to the valve seat side, the fuel in the pump chamber 12 is a groove 491 in the contact portion 49 of the suction valve 46, a gap between the hat portion 47 of the suction valve 46 and the protrusion 59 of the stopper 57, an orifice. 73, passes through the hole 72, and flows into the valve chamber 44.
In the third embodiment, the same operational effects as those in the first embodiment and the second embodiment can be obtained.

(Other embodiments)
In the above-described embodiment, the electromagnetic valve unit 40 has been described as a normally open valve in which the movable core 82 opens the intake valves 41 and 46 when the coil 89 is not energized. On the other hand, in other embodiments, the electromagnetic valve unit may be a normally closed valve in which the movable core closes the suction valve when the coil is not energized.
In the embodiment described above, the intake valves 41 and 46 and the needle 81 are configured separately. On the other hand, in another embodiment, the suction valve and the needle may be configured integrally.
In the embodiment described above, the hole diameter of the orifice 70 is larger than the lift amount of the suction valve 41. On the other hand, in other embodiments, the hole diameter of the orifice may be smaller than the lift amount of the suction valve 41.
The present invention is not limited to the above embodiment, and can be implemented in various forms without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... High pressure pump 12 ... Pump chamber 13 ... Introduction passage 43 ... 1st guide part 41, 46 ... Suction valve 56 ... 2nd guide part 59 ... Projection part (1st 2 Guide)
50, 57 ... Stopper 44 ... Valve chamber 70, 71, 73 ... Orifice

Claims (9)

A plunger (20);
A pump chamber (12) in which fuel is pressurized by reciprocating movement of the plunger, and a pump body (10) having an introduction passage (13) communicating with the pump chamber;
A valve body (42) seated on and away from a valve seat (62) formed on the inner wall of the introduction passage, and a first guide portion (43) extending in the movement direction of the valve body, A suction valve (41, 46) for communicating and blocking the introduction passage;
The suction valve has a second guide portion (56, 59) that comes into sliding contact with the first guide portion, and a contact portion (54) that comes into contact with the suction valve, and restricts movement of the suction valve in the valve opening direction. Stoppers (50, 57) to be
A valve chamber (44) formed between the stopper and the suction valve is provided at a position where the first guide portion and the second guide portion overlap when the suction valve is opened. A high-pressure pump (1), comprising an orifice (70, 71, 73) communicating with each other.   The orifice (70) is provided in the first guide portion of the suction valve, and an opening sectional area when the suction valve is opened is smaller than an opening sectional area when the suction valve is closed. The high-pressure pump according to claim 1.   3. The area where the orifice and the second guide portion overlap when the suction valve is opened is larger than the area where the orifice and the suction valve overlap when the suction valve is closed. The high-pressure pump described.   The orifices (71, 73) are provided in the second guide portion of the stopper, and an opening sectional area when the suction valve is opened is smaller than an opening sectional area when the suction valve is closed. The high-pressure pump according to claim 1, wherein   The area where the orifice and the first guide part overlap when the suction valve is opened is larger than the area where the orifice and the first guide part overlap when the suction valve is closed. 4. The high pressure pump according to 4.   The high-pressure pump according to any one of claims 1 to 5, wherein a hole diameter of the orifice is larger than a lift amount when the suction valve moves from the closed state to the open state.   7. The high-pressure pump according to claim 1, wherein when the plunger moves down from the discharge stroke to the suction stroke, the orifice causes fuel to flow from the valve chamber to the pump chamber. .   The high pressure according to any one of claims 1 to 7, wherein the orifice regulates a flow of fuel from the pump chamber to the valve chamber during a metering stroke during the ascent of the plunger. pump.   The said orifice flows a fuel from the said pump chamber to the said valve chamber when changing to a discharge stroke from the metering stroke during the said raise of the said plunger, The Claim 1 characterized by the above-mentioned. High pressure pump.

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