JP2019086006A - High pressure pump - Google Patents

Abstract

A high-pressure pump is provided that improves the drive performance of an electromagnetic drive unit that controls the amount of discharge. A valve member (40) is seated on and off a valve seat (34) of a valve body (30) provided in a fuel passage (100) to block and allow fuel flow in the fuel passage (100). The stopper 50 contacts the valve member 40 and restricts the movement of the valve member 40 in the valve opening direction. A first spring 21 provided in a volume chamber 54 formed between the valve member 40 and the stopper 50 biases the valve member 40 in the valve closing direction. It has a conduit 55 communicating between the pressure chamber and the volume chamber 54 . The conduit 55 extends in a direction perpendicular to the sliding direction of the valve member 40 . The stopper 50 has a bottom portion 52 that closes the pressurizing chamber side end of the volume chamber 54, and a third passage 123 positioned between the pipe line 55 and the pressurizing chamber. The third passage 123 is formed only by the stopper 50 . [Selection drawing] Fig. 1

Description

  The present invention relates to a high pressure pump which pressurizes fuel sucked into a pressurizing chamber by reciprocating movement of a plunger.

Conventionally, a high pressure pump is known which sucks and pressurizes fuel into a pressurizing chamber by reciprocating movement of a plunger. In Patent Document 1, when the fuel in the pressurizing chamber is pressurized by the reciprocating movement of the plunger, the fuel passage on the fuel supply side of the pressurizing chamber is opened by the operation of the valve member, and a part of the fuel in the pressurizing chamber is The discharge amount is variable by returning to the fuel supply side. However, in this configuration, the dynamic pressure of the fuel flow returned from the pressurizing chamber to the fuel supply side is applied to the pressurizing chamber side end of the valve member that opens and closes the fuel passage, whereby the valve member blocks the fuel passage. It is a concern to do. For this reason, it is necessary to increase the load of the spring that biases the valve member in the valve opening direction, and to increase the current value necessary for the operation of the electromagnetic drive unit that drives the valve member.
On the other hand, in Patent Document 2, since the electromagnetic drive portion directly operates the valve member, the fuel flow rate is increased, and therefore, when the lift amount of the valve member is increased, the mover of the electromagnetic drive portion and the stator The initial gap between them becomes large. For this reason, there is a concern that the current value required for the operation of the electromagnetic drive unit will be large. In addition, there is a concern that the size of the electromagnetic drive unit may be increased and the operation noise may be increased.
In addition, when the seat diameter of the valve member is increased, fuel resistance when the valve member operates increases.

JP 2002-521616 gazette JP 2001-295720 A

  An object of the present invention is to provide a high pressure pump which improves the drive performance of an electromagnetic drive unit for controlling the discharge amount.

According to the invention of claim 1, the housing has a pressurizing chamber for pressurizing the fuel by reciprocating movement of the plunger, and a fuel passage for guiding the fuel to the pressurizing chamber. The valve member blocks and allows fuel flow in the fuel passage by being seated and separated from the valve seat of the valve body provided in the fuel passage. The stopper regulates movement of the valve member in the valve opening direction by abutting on the valve member. A biasing member provided in a volume chamber formed between the valve member and the stopper biases the valve member in the valve closing direction. The electromagnetic drive unit is provided on the side opposite to the pressure chamber with respect to the valve member, and generates a magnetomotive force to move the valve member in the valve opening direction or the valve closing direction by energizing the coil unit.
The high-pressure pump according to claim 1 has a conduit communicating the pressure chamber and the volume chamber. Also, the conduit extends in a direction perpendicular to the sliding direction of the valve member. The stopper has a bottom for closing the end on the pressurizing chamber side of the volume chamber, and a stopper passage (123) located between the conduit and the pressurizing chamber. The stopper passage is formed only by the stopper.

1 is a partial cross-sectional view of a high pressure pump according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the high pressure pump by 1st Embodiment of this invention. 1 is a partial cross-sectional view of a high pressure pump according to a first embodiment of the present invention. 1 is a partial cross-sectional view of a high pressure pump according to a first embodiment of the present invention. The fragmentary sectional view of the high pressure pump by a 2nd embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described based on the drawings.
First Embodiment
A high pressure pump according to a first embodiment of the present invention is shown in FIGS. The high pressure pump 10 is, for example, a fuel pump that supplies fuel to an injector of a diesel engine or a gasoline engine.

As shown in FIG. 2, the high pressure pump 10 includes a housing body 11, a cover 12, a plunger 13, a valve body 30, a valve member 40, a stopper 50, a first spring 21, a needle 60, a second spring 22 and an electromagnetic drive unit 70. And so on.
The first spring 21 of the present embodiment corresponds to an example of the “biasing member” described in the claims.
The housing body 11 and the cover 12 constitute a "housing" in the claims. The housing body 11 is made of, for example, martensitic stainless steel. The housing body 11 forms a cylindrical cylinder 14. A plunger 13 is supported on the cylinder 14 of the housing body 11 so as to be reciprocally slidable in the axial direction.

  The housing body 11 forms an introduction passage 111, a suction passage 112, a pressure chamber 113, a discharge passage 114, and the like. The housing body 11 forms a tubular portion 15. The cylindrical portion 15 has a passage 151 communicating the introduction passage 111 and the suction passage 112 inside. The cylindrical portion 15 is formed substantially perpendicular to the central axis of the cylinder 14, and the inner diameter changes in the middle. The housing main body 11 forms a step surface 152 at a portion where the inner diameter of the cylindrical portion 15 changes. A valve body 30 is provided in the passage 151 formed in the cylindrical portion 15.

  A fuel chamber 16 is formed between the housing body 11 and the cover 12. The housing main body 11 is formed with a fuel inlet (not shown) communicating with the fuel chamber 16. Fuel is supplied from the fuel tank to the fuel chamber 16 by a low pressure fuel pump (not shown) through the fuel inlet. The introduction passage 111 communicates the fuel chamber 16 with the passage 151 formed on the inner peripheral side of the cylindrical portion 15. One end of the suction passage 112 is in communication with the pressure chamber 113. The other end of the suction passage 112 is open to the inner peripheral side of the step surface 152. The introduction passage 111 and the suction passage 112 are connected via the inner peripheral side of the valve body 30. The pressure chamber 113 communicates with the discharge passage 114 on the opposite side to the suction passage 112. Here, the introduction passage 111, the passage 151 and the suction passage 112 constitute a "fuel passage" in the claims. In the present embodiment, the “fuel passage” is indicated by the fuel passage 100.

  The plunger 13 is axially slidably supported by the cylinder 14 of the housing body 11. The pressure chamber 113 is formed on one end side of the plunger 13 in the reciprocation direction. A head 17 provided on the other end side of the plunger 13 is coupled to the spring stopper 18. A plunger spring 19 is provided between the spring stopper 18 and the housing body 11. The spring stopper 18 is biased toward the cam (not shown) by the biasing force of the plunger spring 19. The plunger 13 reciprocates by contacting with the cam through a tappet (not shown).

  One end of the plunger spring 19 contacts the housing body 11 and the other end contacts the spring stopper 18. The plunger spring 19 has a force extending in the axial direction. Thereby, the plunger spring 19 biases the tappet (not shown) toward the cam side via the spring stopper 18. An oil seal 23 is sealed in a fluid-tight manner between an outer peripheral surface of the plunger 13 on the head 17 side and an inner peripheral surface of the housing main body 11 forming the cylinder 14 for housing the plunger 13. The oil seal 23 prevents the infiltration of oil from the inside of the engine into the pressure chamber 113 and prevents the outflow of fuel from the pressure chamber 113 into the engine.

  The discharge valve portion 90 forming the fuel outlet 91 is provided on the discharge passage 114 side of the housing main body 11. The discharge valve unit 90 intermittently discharges the fuel pressurized in the pressure chamber 113. The discharge valve portion 90 has a check valve 92, a regulating member 93 and a spring 94. The check valve 92 is formed in a bottomed cylindrical shape including a bottom portion 921 and a cylindrical portion 922 cylindrically extending from the bottom portion 921 to the opposite pressure chamber 113 side, and is provided to be reciprocally movable in the discharge passage 114. The regulating member 93 is formed in a tubular shape, and is fixed to the housing main body 11 forming the discharge passage 114. One end of the spring 94 is in contact with the restricting member 93, and the other end is in contact with the cylindrical portion 922 of the check valve 92. The check valve 92 is biased toward the valve seat 95 formed by the housing body 11 by the biasing force of the spring 94. The check valve 92 closes the discharge passage 114 when the end on the bottom 921 side is seated on the valve seat 95, and opens the discharge passage 114 by separating from the valve seat 95. When the check valve 92 moves to the opposite side to the valve seat 95, the end on the side opposite to the bottom portion 921 of the cylindrical portion 922 is in contact with the restricting member 93 so that the movement is restricted.

  When the pressure of the fuel in the pressure chamber 113 increases, the force received by the check valve 92 from the fuel on the pressure chamber 113 side increases. The force received by the check valve 92 from the fuel on the pressure chamber 113 side is greater than the sum of the biasing force of the spring 94 and the force received from the fuel downstream of the valve seat 95, ie, the fuel in the delivery pipe (not shown). Then, the check valve 92 leaves the valve seat 95. Thus, the fuel in the pressurizing chamber 113 is discharged from the fuel outlet 91 through the discharge passage 114, ie, the through hole 923 formed in the cylindrical portion 922 of the check valve 92 and the inner side of the cylindrical portion 922. Is discharged to the outside of the

  On the other hand, when the pressure of the fuel in the pressure chamber 113 decreases, the force received by the check valve 92 from the fuel on the pressure chamber 113 side decreases. When the force received by the check valve 92 from the fuel on the pressure chamber 113 side is smaller than the sum of the biasing force of the spring 94 and the force received from the fuel downstream of the valve seat 95, the check valve 92 Seat at 95. As a result, the fuel in the delivery pipe (not shown) is restricted from flowing into the pressurizing chamber 113.

  The valve body 30 is fixed to the housing body 11 as shown in FIG. The valve body 30 is fixed to the inside of the passage 151 of the housing body 11 by, for example, press fitting and a locking member 20 or the like. That is, the valve body 30 is provided in the middle of the passage 151 constituting the fuel passage 100. The valve body 30 is formed in a bottomed cylindrical shape including a bottom portion 31 and a cylindrical portion 32 cylindrically extending from the bottom portion 31 to the pressurizing chamber 113 side.

  The valve body 30 has, on the side of the pressure chamber 113 of the bottom portion 31, a recessed portion 33 which is recessed toward the side opposite to the pressure chamber 113. A valve seat 34 is formed on the outer edge of the recessed portion 33 on the wall surface of the bottom portion 31 on the pressure chamber 113 side. That is, the valve body 30 has a valve seat 34 on the side wall surface of the pressure chamber 113. The valve seat 34 is formed in a tapered shape that makes a predetermined angle with the axis of the valve body 30.

  The valve body 30 has a first guide 35 at the center of the bottom 31. The first guide portion 35 is formed so as to cylindrically protrude from the central portion of the bottom portion 31 to the anti-recessed portion 33 side. The valve body 30 has a first insertion hole 351 connecting a wall surface forming the recessed portion 33 of the first guide portion 35 and a wall surface on the non-recessed portion 33 side. Further, on the outer peripheral side of the first insertion hole 351 of the bottom portion 31, a first passage 121 for connecting the wall surface forming the recessed portion 33 and the wall surface on the anti-recessed portion 33 side is formed. A plurality of first passages 121 are formed circumferentially with respect to the axis of the valve body 30.

  The valve member 40 includes a substantially cylindrical shaft portion 41 and a substantially disc-like umbrella portion 42 connected to an end of the shaft portion 41 on the pressure chamber 113 side. The stem portion 41 of the valve member 40 is inserted into the first insertion hole 351 of the first guide portion 35, and is provided so as to be reciprocally movable in the axial direction of the stem portion 41 inside the valve body 30. The wall surface on the valve seat 34 side of the umbrella portion 42 corresponds to the shape of the valve seat 34, and is formed in a tapered shape that forms a predetermined angle with the axis of the shaft portion 41. The valve member 40 shuts off the flow of fuel flowing in the fuel passage 100 by the umbrella portion 42 sitting on the valve seat 34 by reciprocating movement, or flows in the fuel passage 100 by leaving the valve seat 34 Allow fuel flow. The valve member 40 also forms an annular second passage 122 with the valve seat 34 when the umbrella portion 42 is separated from the valve seat 34.

  The diameter of the first insertion hole 351 of the first guide portion 35 is substantially equal to the diameter of the shaft portion 41 of the valve member 40 or slightly larger than the diameter of the shaft portion 41. Thus, the valve member 40 reciprocates inside the valve body 30 while the outer wall of the shaft 41 slides on the wall surface of the first guide 35 forming the first insertion hole 351. Therefore, when the valve member 40 reciprocates, the reciprocation is guided by the first guide portion 35.

  The shaft portion 41 has a small diameter portion 411 recessed inward in the radial direction from the outer peripheral wall midway in the axial direction. Thereby, the contact area between the shaft portion 41 and the first guide portion 35 is smaller than that in the case where the shaft portion 41 does not have the small diameter portion 411. Therefore, when the valve member 40 reciprocates, the resistance due to the sliding between the shaft portion 41 and the first guide portion 35 can be reduced. At the same time, it also has a role to lubricate the sliding portion of the shaft portion 41.

  The stopper 50 is provided on the pressure chamber 113 side of the valve member 40. The stopper 50 includes a cylindrical portion 51, a bottom portion 52 closing an end of the cylindrical portion 51 on the counter valve member 40 side, and an annular expanded portion 53 formed on the radially outer side of the bottom portion 52. The stopper 50 is fixed to the valve body 30 by welding the outer peripheral wall of the expanded portion 53 to the inner peripheral wall of the cylindrical portion 32 of the valve body 30.

In the expanded portion 53 of the stopper 50, a third passage 123 is formed which connects the wall surface of the expanded portion 53 on the pressure chamber 113 side and the wall surface of the anti-pressure chamber 113 side. A plurality of third passages 123 are formed circumferentially with respect to the axis of the stopper 50.
A substantially annular intermediate passage 124 is formed between the second passage 122 and the third passage 123 and surrounded by the inner peripheral wall of the cylindrical portion 32 of the valve body 30 and the outer peripheral wall of the cylindrical portion 51 of the stopper 50 There is.
The stopper 50 restricts the movement of the valve member 40 in the pressure chamber 113 side, that is, the valve opening direction. The stopper 50 forms a volume chamber 54 surrounded by the valve member 40, the inner wall of the cylindrical portion 51 and the bottom portion 52 when the valve member 40 abuts against the stopper 50. A pipe 55 communicating the volume chamber 54 with the intermediate passage 124 is formed in the cylindrical portion 51 of the stopper 50.

  The first passage 121, the second passage 122, the third passage 123, and the intermediate passage 124 described above are included in the passage 151 formed in the housing main body 11, respectively. That is, the fuel passage 100 includes a first passage 121, a second passage 122, a third passage 123 and an intermediate passage 124. Thus, when the fuel travels from the fuel chamber 16 side to the pressurizing chamber 113 side, the fuel flows through the first passage 121, the second passage 122, the intermediate passage 124 and the third passage 123 in this order. On the other hand, when the fuel travels from the pressurizing chamber 113 side to the fuel chamber 16 side, the fuel flows through the third passage 123, the intermediate passage 124, the second passage 122, and the first passage 121 in this order.

  As shown in FIG. 1, the first spring 21 is accommodated in the volume chamber 54. The first spring 21 abuts against a first spring seat 46 formed at one end of the valve head 42 of the valve member 40 and has a second spring seat 56 formed at the other end of the bottom 52 of the stopper 50. In contact with The first and second spring seats 46 and 56 restrict radial movement at both ends of the first spring 21. The first spring 21 has a force extending in the axial direction, and biases the valve member 40 in the direction opposite to the stopper 50, that is, in the valve closing direction.

  A first recess 47 recessed toward the valve seat 34 is provided at an end of the valve member 40 on the stopper 50 side. The valve member 40 has a cylindrical projecting portion 43 that protrudes toward the stopper 50 on the radially outer side of the first recess 47. The end on the stopper 50 side of the projecting portion 43 and the end on the valve member 40 side of the cylindrical portion 51 of the stopper 50 can be in contact with each other. The outer edge of the first recess 47 is provided radially inward of the outer edge of the umbrella portion 42 and radially outward of the outer edge of the second spring seat 56 of the stopper 50. The first spring 21 may be compressed between the first spring seat 46 and the second spring seat 56 and may be radially distorted as it contracts. The distance between the outer edge of the second spring seat 56 and the outer edge of the first recess 47 is set to be larger than the size in which the first spring 21 is distorted in the radial direction. For this reason, the first spring 21 is prevented from coming into contact with the end surface of the valve member 40 on the stopper 50 side. Further, by setting the position of the outer edge of the first recess 47, the area in which the projection 43 of the valve member 40 and the cylindrical portion 51 of the stopper 50 abut is set, and ringing between the valve member 40 and the stopper 50 is suppressed. can do. Thereby, the load of the first spring 21 which biases the valve member 40 in the valve opening direction can be set small.

The outer diameter D1 of the end of the protrusion 43 on the stopper 50 side is smaller than the outer diameter D2 of the end of the cylindrical portion 51 of the stopper 50 on the valve member 40 side. Therefore, when the valve member 40 is in contact with the stopper 50, the stopper 50 exerts a dynamic pressure of the fuel flow which is discharged from the pressurizing chamber 113 and flows through the intermediate passage 124 in the metering stroke on the valve member 40. Suppress.
A chamfered portion 58 of 0.2 mm on one side, for example, is formed in the boundary area between the end surface of the cylindrical portion 51 of the stopper 50 on the valve member 40 side and the outer wall surface in the radial outward direction. The outer diameter D1 of the end of the protrusion 43 on the stopper 50 side is smaller by, for example, 0.4 mm than the outer diameter D2 of the end of the cylindrical portion 51 of the stopper 50 on the valve member 40 side. Thus, by forming the outer diameter D1 to be slightly smaller than the outer diameter D2, when the stopper 50 and the valve member 40 abut, turbulence is generated in the fuel flow flowing through the intermediate passage 124 on the outer side of the stopper 50 Can be suppressed. Further, when the valve member 40 is seated on the valve seat 34, since the umbrella portion 42 of the valve member 40 is stably seated between D1 and D3 of the valve seat 34, it is not necessary to make the diameter D3 of the recessed portion 33 smaller. . Furthermore, since the stopper 50 is slightly larger than the valve member 40, the size of the passage cross-sectional area between D2-D4 of the intermediate passage 124 can be secured.

As shown in FIG. 4, a chamfered portion 48 is formed in the boundary area between the end surface 401 of the projecting portion 43 on the stopper 50 side and the outer wall surface 402 on the radially outer side. The length in the valve opening direction and the valve closing direction of the valve member 40 of the chamfered portion 48 is L1. Here, if the length in the moving direction of the valve member 40 of the chamfered portion 48 is made large as L2 shown by a broken line, the dynamic pressure applied to the valve member 40 by the fuel flow from the third passage 123 to the intermediate passage 124 Becomes larger. In the present embodiment, the dynamic pressure applied to the valve member 40 by the flow of fuel flowing from the third passage 123 to the intermediate passage 124 is reduced by forming the length L1 in the movement direction of the valve member 40 smaller than L2. ing.
In FIG. 4, the alternate long and short dash line m indicates the central axis of the valve member 40 and the stopper 50.

  As shown in FIGS. 2 and 3, the electromagnetic drive unit 70 includes a coil 71, a fixed core 72, a movable core 73, a flange 75, and the like. The coil 71 is wound around a resin-made spool 78, and generates a magnetic field by being energized. The fixed core 72 is formed of a magnetic material. The fixed core 72 is accommodated on the inner peripheral side of the coil 71. The movable core 73 is formed of a magnetic material. The movable core 73 is disposed to face the fixed core 72. The movable core 73 is accommodated on the inner peripheral side of the cylindrical member 79 and the flange 75 formed of nonmagnetic material so as to be capable of reciprocating in the axial direction. The cylindrical member 79 prevents a magnetic short circuit between the fixed core 72 and the flange 75.

  The flange 75 is formed of a magnetic material and is attached to the cylindrical portion 15 of the housing body 11. Thus, the flange 75 holds the electromagnetic drive unit 70 in the housing body 11 and closes the end of the cylindrical portion 15. The flange 75 has a second guide portion 76 formed in a tubular shape at a central portion. The second guide portion 76 has a second insertion hole 761 communicating the valve body 30 side of the flange 75 and the counter valve body 30 side.

  The needle 60 is formed in a substantially cylindrical shape, and is inserted into a second insertion hole 761 formed in the second guide portion 76 of the flange 75. The needle 60 is provided to be reciprocally movable in the axial direction inside the second insertion hole 761. The diameter of the second insertion hole 761 is approximately the same as the diameter of the needle 60 or slightly larger than the diameter of the needle 60. Thus, the needle 60 reciprocates while the outer wall slides on the wall surface of the second guide portion 76 forming the second insertion hole 761. Therefore, when the needle 60 reciprocates, the reciprocation is guided by the second guide portion 76.

  The needle 60 has a substantially planar wall surface 61 formed by chamfering a part of the outer peripheral wall. Thus, by chamfering a part of the outer peripheral wall of the needle 60, the contact area between the needle 60 and the second guide portion 76 is reduced. Thereby, the resistance due to the sliding between the needle 60 and the second guide portion 76 can be reduced.

  A gap 62 is formed between the wall surface 61 of the needle 60 and the inner peripheral wall of the second guide portion 76 forming the second insertion hole 761. Therefore, the fuel on the valve body 30 side of the flange 75 can flow to the counter valve body 30 side of the flange 75 via the gap 62. As a result, the pressure on the valve body 30 side of the flange 75 and the pressure on the counter valve body 30 side become substantially the same. In addition, the gap 62 also functions as an air vent path for air accumulated at a portion around the movable core 73.

  The needle 60 is assembled integrally with the movable core 73 by press-fitting or welding one end of the needle 60 to the movable core 73. Further, the end face 63 formed at the other end of the needle 60 can be in contact with the end face 45 formed at the end of the stem portion 41 of the valve member 40 on the side opposite to the umbrella portion 42. The needle 60 is movable in the same direction as the movement direction when the valve member 40 is opened or closed.

  The second spring 22 is provided between the fixed core 72 and the movable core 73. The second spring 22 biases the movable core 73 to the valve member 40 side. The force by which the second spring 22 biases the movable core 73 is larger than the force by which the first spring 21 biases the valve member 40. That is, the second spring 22 biases the movable core 73 and the needle 60 against the biasing force of the first spring 21 toward the valve member 40, that is, in the valve opening direction of the valve member 40. Thus, when the coil 71 is not energized, the fixed core 72 and the movable core 73 are separated from each other. Therefore, when the coil 71 is not energized, the needle 60 integral with the movable core 73 moves toward the valve member 40 by the biasing force of the second spring 22, and the valve member 40 separates from the valve seat 34 of the valve body 30. Sitting

Next, the operation of the high pressure pump 10 configured as described above will be described.
(1) Intake stroke When the plunger 13 moves downward in FIG. 2, the energization of the coil 71 is stopped. For this reason, the valve member 40 receives the biasing force of the second spring 22 via the needle 60 integral with the movable core 73 and separates from the valve seat 34. Further, when the plunger 13 moves downward in FIG. 2, the pressure in the pressure chamber 113 decreases. Therefore, the force that the valve member 40 receives from the fuel on the recessed portion 33 side is larger than the force received from the fuel on the pressurizing chamber 113 side. As a result, a force is applied to the valve member 40 in a direction away from the valve seat 34, and the valve member 40 leaves the valve seat 34. The valve member 40 moves until the protrusion 43 abuts on the cylindrical portion 51 of the stopper 50. When the valve member 40 is opened, the fuel chamber 16 communicates with the pressurizing chamber 113 via the introduction passage 111, the passage 151 and the suction passage 112. Therefore, the fuel in the fuel chamber 16 is sucked into the pressurizing chamber 113 via the first passage 121, the second passage 122, the intermediate passage 124 and the third passage 123 in this order. At this time, the valve member 40 abuts against the stopper 50 so that the opening on the pressure chamber 113 side of the protrusion 43 is closed by the stopper 50. At this time, the fuel of the intermediate passage 124 can flow into the volume chamber 54 through the pipe 55. Therefore, the pressure of the volume chamber 54 becomes equal to the pressure of the intermediate passage 124.

(2) Metering step When the plunger 13 ascends from the bottom dead center to the top dead center, the fuel in the pressure chamber 113 is discharged, and under dynamic pressure, the valve member 40 receives the pressure in the pressure chamber 113 side. A force is applied from the fuel in the direction of seating on the valve seat 34. However, when the coil 71 is not energized, the needle 60 is biased toward the valve member 40 by the biasing force of the second spring 22. Therefore, the movement of the valve member 40 to the valve seat 34 side is restricted by the needle 60. The end of the valve member 40 on the pressure chamber 113 side is completely closed by the end of the stopper 50 on the valve member 40 side. For this reason, the dynamic pressure of the fuel flow which is pressurized in the pressurizing chamber 113 and flows through the intermediate passage 124 is reduced to a very small amount and applied to the valve member. As a result, while the energization of the coil 71 is stopped, the valve member 40 is kept separated from the valve seat 34. As a result, the fuel discharged from the pressure chamber 113 by the upward movement of the plunger 13 is transferred to the third passage 123, the intermediate passage 124, the second passage 122, and so on in the reverse of the case where The fuel is returned to the fuel chamber 16 via the first passage 121 in this order.

  When the coil 71 is energized in the middle of the metering stroke, a magnetic circuit is formed on the fixed core 72, the flange 75 and the movable core 73 by the magnetic field generated in the coil 71. As a result, a magnetic attraction force is generated between the fixed core 72 and the movable core 73 which are separated from each other. When the magnetic attraction force generated between the fixed core 72 and the movable core 73 becomes larger than the difference between the biasing forces of the second spring 22 and the first spring 21, the movable core 73 moves to the fixed core 72 side. Therefore, the needle 60 integral with the movable core 73 also moves to the fixed core 72 side. When the needle 60 moves to the fixed core 72 side, the valve member 40 and the needle 60 are separated, and the valve member 40 does not receive force from the needle 60. At this time, since the first recess 47 is provided in the valve member 40, ringing between the valve member 40 and the stopper 50 is suppressed. As a result, the valve member 40 is separated from the stopper 50 by the biasing force of the first spring 21 and receives the dynamic pressure of the fuel discharged from the pressurizing chamber 113 and instantaneously moves to the valve seat 34 side.

  The valve member 40 moves toward the valve seat 34, and the valve member 40 is seated on the valve seat 34, that is, the valve is closed, whereby the second passage 122 is closed and the flow of fuel flowing through the fuel passage 100 is shut off. . Thus, the fuel metering process from the pressure chamber 113 to the fuel chamber 16 is completed. When the plunger 13 ascends, the second passage 122 is closed to block the flow of fuel between the pressure chamber 113 and the fuel chamber 16, whereby the amount of fuel returned from the pressure chamber 113 to the fuel chamber 16 is increased. Adjusted.

(3) Pressurization Step If the plunger 13 is further raised toward the top dead center with the space between the pressure chamber 113 and the fuel chamber 16 closed, the pressure of the fuel in the pressure chamber 113 is increased. When the pressure of the fuel in the pressure chamber 113 becomes equal to or higher than the predetermined pressure, the biasing force of the spring 94 of the discharge valve portion 90 and the force received by the check valve 92 from the fuel downstream of the valve seat 95 are reversed. The stop valve 92 disengages from the valve seat 95. As a result, the discharge valve unit 90 is opened, and the fuel pressurized in the pressure chamber 113 is discharged from the high pressure pump 10 through the discharge passage 114. The fuel discharged from the high pressure pump 10 is supplied to a delivery pipe (not shown), accumulated therein, and supplied to the injector. At this time, the needle 60 is separated from the valve member 40. Therefore, even if the valve member 40 receives a force from the fuel on the pressure chamber 113 side, the force is not transmitted to the needle 60.

  When the plunger 13 moves to the top dead center, the plunger 13 moves downward in FIG. 2 again. As a result, the pressure of the fuel in the pressurizing chamber 113 is reduced. Therefore, the valve member 40 separates from the valve seat 34 again, and fuel is sucked into the pressurizing chamber 113 from the fuel chamber 16.

When the pressure of the fuel in the pressure chamber 113 rises to a predetermined value, the energization of the coil 71 may be stopped. When the pressure of the fuel in the pressure chamber 113 rises, the force in the direction in which the fuel in the pressure chamber 113 is seated on the valve seat 34 is greater than the force that the valve member 40 receives in the direction of leaving the valve seat 34 Become. Therefore, even if energization of the coil 71 is stopped, the valve member 40 maintains the seating state on the valve seat 34 by the force received from the fuel on the pressure chamber 113 side. As described above, the power consumption of the electromagnetic drive unit 70 can be reduced by stopping the energization of the coil 71 at a predetermined time.
By repeating the above-described steps (1) to (3), the high pressure pump 10 pressurizes and discharges the sucked fuel. The discharge amount of the fuel is adjusted by controlling the energization timing to the coil 71 of the electromagnetic drive unit 70.

  In the present embodiment, the outer diameter D1 of the end of the valve member 40 on the pressure chamber 113 side is smaller than the outer diameter D2 of the end of the stopper 50 on the valve member 40 side. Further, the chamfered portion 48 formed on the radially outer side of the end portion on the stopper 50 side of the projecting portion 43 is formed so that the length L1 in the valve opening direction and the valve closing direction of the valve member 40 is relatively small. Therefore, it is possible to suppress the dynamic pressure of the fuel flow which is discharged from the pressure chamber 113 and flows through the intermediate passage 124 from being applied to the valve member in the metering process. Thus, the valve member 40 is prevented from closing by the dynamic pressure of the fuel flow, and the load of the second spring 22 which biases the valve member 40 in the valve opening direction via the needle 60 can be set small. . As a result, the current value required for the operation of the electromagnetic drive unit 70 for attracting the needle 60 in the valve closing direction against the biasing force of the second spring 22 is reduced, and the physical size of the electromagnetic drive unit 70 is miniaturized. be able to. Furthermore, by setting the load of the second spring 22 small, it is possible to reduce the operation noise generated by the collision between the umbrella portion 42 of the valve member 40 and the valve seat 34 and the projection 43 of the valve member 40 and the stopper 50. it can.

In the present embodiment, a first recess 47 recessed toward the valve seat 34 is provided on the inside of the projecting portion 43 of the valve member 40. Ringing between the valve member 40 and the stopper 50 can be suppressed by reducing the area where the end of the projection 43 of the valve member 40 on the stopper side abuts on the end of the stopper 50 on the valve member 40 side. it can. Thereby, the load of the first spring 21 which biases the valve member 40 in the valve opening direction can be set small.
Further, the outer edge of the first recess 47 is located radially outside the outer edge of the second spring seat 56. Therefore, when the first spring 21 contracts between the first spring seat 46 and the second spring seat and is distorted in the radial direction, the inner wall of the first recess 47 of the valve member 40 contacts the first spring 21 Can be prevented. Furthermore, when assembling the first spring 21, the contact between the inner wall of the first recess 47 of the valve member 40 and the first spring 21 is suppressed, and the wear and breakage of the first spring 21 can be prevented.

Second Embodiment
A high pressure pump according to a second embodiment of the present invention is shown in FIG. In the present embodiment, at the end of the stopper 50 on the valve member 40 side, a second recess 57 is provided which is recessed on the opposite side to the valve member 40. The outer edge of the second recess 57 is provided radially inward of the outer edge of the cylindrical portion 51 of the stopper 50 and radially outward of the outer edge of the first spring seat 46 of the valve member 40. The distance between the outer edge of the first spring seat 46 and the outer edge of the second recess 57 is set larger than the distance by which the first spring 21 contracts and is distorted in the radial direction.

The second spring seat 56 of the present embodiment corresponds to an example of the “spring seat” recited in the claims.
The first spring 21 of the present embodiment corresponds to an example of the “biasing member” described in the claims.

For this reason, in the present embodiment, when the first spring 21 is contracted between the first spring seat 46 and the second spring seat 56 and distorted in the radial direction, the inner wall of the second recess 57 of the stopper 50 and the first spring Contact with the spring 21 can be prevented. Furthermore, when the first spring 21 is assembled, the contact between the inner wall of the second recess 57 of the stopper 50 and the first spring 21 is suppressed, and the wear and breakage of the first spring 21 can be prevented.
Furthermore, by setting the position of the outer edge of the second recess 57, the area in which the valve member 40 and the stopper 50 abut can be set, and ringing of the valve member 40 and the stopper 50 can be suppressed. As a result, the load of the first spring 21 which biases the valve member 40 in the valve closing direction can be reduced. Thereby, the load of the second spring 22 that biases the valve member 40 in the valve opening direction against the biasing force of the first spring 21 can be set small. As a result, it is possible to reduce the current value necessary for the operation of the electromagnetic drive unit 0 that sucks the needle 60 in the valve closing direction against the biasing force of the second spring 22. Further, the size of the electromagnetic drive unit 70 can be reduced. Furthermore, the operation noise which collides with the valve member 40 and the valve seat 34, and the valve member 40 and the stopper 50 can be made small.

(Other embodiments)
In the above-described embodiments, the valve member is opened when the coil of the electromagnetic drive unit is not energized, and the valve member is closed when the coil is energized. . On the other hand, in another embodiment of the present invention, a normally closed valve structure may be employed in which the valve member is opened when the coil portion is energized.
As described above, the present invention is not limited to the above-described embodiment, and in addition to the combination of the first and second embodiments, the present invention can be applied to various embodiments without departing from the scope of the invention. .

  10: high pressure pump, 11: housing body (housing), 12: cover (housing), 13: plunger, 21: first spring (biasing member), 22: second spring, 30: valve body, 34: valve seat , 40: valve member, 42: umbrella portion (valve member), 50: stopper, 51: cylindrical portion (stopper), 52 bottom portion (stopper), 53: extended portion (stopper), 60: needle, 70: electromagnetic drive portion 71: coil (coil portion) 100: fuel passage 113: pressure chamber 121: first passage (fuel passage) 122: second passage (fuel passage) 123: third passage (fuel passage) 124: Intermediate passage (fuel passage)

Claims (1)

A reciprocating plunger;
A pressurizing chamber in which fuel is pressurized by the plunger, and a housing having a fuel passage for guiding the fuel to the pressurizing chamber;
A valve body provided in the fuel passage and having a valve seat on a wall surface on the pressure chamber side;
A valve member that blocks fuel flow in the fuel passage by being seated on the valve seat and allows fuel flow by moving away from the valve seat;
A stopper for restricting the movement of the valve member in the valve opening direction by contacting the valve member;
A volume chamber formed between the valve member and the stopper;
An urging member provided in the volume chamber for urging the valve member in the valve closing direction;
And an electromagnetic drive unit which is provided on the side opposite to the pressure chamber with respect to the valve member and generates a magnetomotive force so that the valve member moves in the valve opening direction or the valve closing direction by energizing the coil portion. ,
A conduit communicating the pressure chamber with the volume chamber;
The conduit extends in a direction perpendicular to the sliding direction of the valve member,
The stopper has a bottom for closing an end of the volume chamber on the pressure chamber side, and a stopper passage (123) located between the conduit and the pressure chamber.
The high pressure pump wherein the stopper passage is formed only by the stopper.

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