JP6032312B2 - High pressure pump - Google Patents

Description

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

Conventionally, a high-pressure pump that sucks and pressurizes fuel into a pressurizing chamber by a reciprocating movement of a plunger is known. 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 operating the valve member, and a part of the fuel in the pressurizing chamber is removed. The discharge amount is varied 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 end of the valve member that opens and closes the fuel passage, so that the valve member blocks the fuel passage. There is a concern to do. For this reason, it is necessary to increase the load of the spring that urges 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 unit directly operates on the valve member, in order to increase the fuel flow rate, if the lift amount of the valve member is increased, the relationship between the mover and the stator of the electromagnetic drive unit is increased. The initial gap between them increases. For this reason, there is a concern that the current value required for the operation of the electromagnetic drive unit will increase. In addition, there is a concern that the physique of the electromagnetic drive unit will increase and the operating noise will increase.
Further, when the seat diameter of the valve member is increased, the fuel resistance when the valve member operates is increased.

JP-T-2002-521616 JP 2001-295720 A

  The objective of this invention provides the high pressure pump which improves the drive performance of the electromagnetic drive part which controls discharge amount.

According to the first aspect of the present invention, the housing includes a pressurizing chamber that pressurizes the fuel by reciprocating the plunger, and a fuel passage that guides the fuel to the pressurizing chamber. The valve member is seated and separated from a valve seat of a valve body provided in the fuel passage, thereby blocking and allowing the fuel flow in the fuel passage. The stopper has a cylindrical portion and a facing surface that is a surface facing the pressure chamber side surface of the valve member. The electromagnetic drive unit is provided on the side opposite to the pressurizing chamber than 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 unit. The high-pressure pump has an intermediate passage that is a substantially annular space through which fuel can flow from the pressurizing chamber side to the valve member side on the outer diameter side of the cylindrical portion. The stopper has a plurality of passages communicating with the intermediate passage and the pressurizing chamber . The intermediate passage is formed between the plurality of passages and the facing surface.

The fragmentary sectional view of the high-pressure pump by a 1st embodiment of the present invention. 1 is a 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 1st embodiment of the present invention. The fragmentary sectional view of the high-pressure pump by a 1st 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 with reference to the drawings.
(First embodiment)
1 to 4 show a high-pressure pump according to a first embodiment of the present invention. The high-pressure pump 10 is a fuel pump that supplies fuel to, for example, 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. Etc.
The first spring 21 of the present embodiment corresponds to an example of an “urging member” described in the claims.
The housing main 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 main body 11 so as to be slidable in the axial direction.

  The housing body 11 forms an introduction passage 111, a suction passage 112, a pressurizing chamber 113, a discharge passage 114, and the like. The housing body 11 forms a cylindrical portion 15. The cylindrical portion 15 has a passage 151 that communicates the introduction passage 111 and the suction passage 112 therein. The cylinder part 15 is formed substantially perpendicularly to the central axis of the cylinder 14, and the inner diameter changes midway. The housing body 11 has a step surface 152 at a portion where the inner diameter changes in the cylindrical portion 15. 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. A fuel inlet (not shown) that communicates with the fuel chamber 16 is formed in the housing body 11. Fuel is supplied to the fuel chamber 16 from a fuel tank by a low-pressure fuel pump (not shown) through the fuel inlet. The introduction passage 111 communicates the fuel chamber 16 and a passage 151 formed on the inner peripheral side of the cylindrical portion 15. One end of the suction passage 112 communicates with the pressurizing chamber 113. The other end of the suction passage 112 opens 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 pressurizing chamber 113 communicates with the discharge passage 114 on the side opposite 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 supported by the cylinder 14 of the housing body 11 so as to be slidable in the axial direction. The pressurizing chamber 113 is formed on one end side in the reciprocating direction of the plunger 13. A head 17 provided on the other end side of the plunger 13 is coupled to a 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 is driven to reciprocate by contacting a cam via a tappet (not shown).

  The plunger spring 19 has one end in contact with the housing main body 11 and the other end in contact with the spring stopper 18. The plunger spring 19 has a force that extends in the axial direction. As a result, the plunger spring 19 biases a tappet (not shown) to the cam side via the spring stopper 18. The outer peripheral surface of the plunger 13 on the head 17 side and the inner peripheral surface of the housing main body 11 forming the cylinder 14 that accommodates the plunger 13 are sealed in a liquid-tight manner by an oil seal 23. The oil seal 23 prevents oil from entering the pressurizing chamber 113 from the engine and prevents fuel from flowing out from the pressurizing chamber 113 to the engine.

  The discharge valve portion 90 that forms the fuel outlet 91 is provided on the discharge passage 114 side of the housing body 11. The discharge valve unit 90 intermittently discharges the fuel pressurized in the pressurizing chamber 113. The discharge valve unit 90 includes 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 that extends in a cylindrical shape from the bottom portion 921 toward the anti-pressurization chamber 113, and is provided so as to be capable of reciprocating in the discharge passage 114. The regulating member 93 is formed in a cylindrical shape and is fixed to the housing body 11 that forms the discharge passage 114. One end of the spring 94 is in contact with the regulating 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 portion 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 side opposite to the valve seat 95, the movement of the check valve 92 is restricted by the end of the cylinder portion 922 on the side opposite to the bottom 921 contacting the restriction member 93.

  When the pressure of the fuel in the pressurizing chamber 113 increases, the force received by the check valve 92 from the fuel on the pressurizing chamber 113 side increases. The force received by the check valve 92 from the fuel on the pressurizing chamber 113 side is larger than the sum of the biasing force of the spring 94 and the fuel received from the fuel on the downstream side of the valve seat 95, that is, the fuel in the delivery pipe (not shown). As a result, the check valve 92 is separated from the valve seat 95. As a result, the fuel in the pressurizing chamber 113 is discharged from the fuel outlet 91 via the discharge passage 114, that is, 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.

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

  As shown in FIG. 3, the valve body 30 is fixed to the housing body 11. 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. 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 that extends from the bottom portion 31 toward the pressurizing chamber 113.

  The valve body 30 has a recessed portion 33 that is recessed toward the counter pressurizing chamber 113 on the pressurizing chamber 113 side of the bottom portion 31. 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 pressurizing chamber 113. The valve seat 34 is formed in a tapered shape that forms a predetermined angle with respect to the axis of the valve body 30.

  The valve body 30 has a first guide portion 35 at the center of the bottom portion 31. The 1st guide part 35 is formed so that it may protrude in the cylinder shape from the center part of the bottom part 31 to the anti-recessed part 33 side. The valve body 30 has a first insertion hole 351 that connects a wall surface forming the recessed portion 33 of the first guide portion 35 and a wall surface on the side opposite to the recessed portion 33. Further, on the outer peripheral side of the first insertion hole 351 in the bottom portion 31, a first passage 121 that connects the wall surface that forms the recessed portion 33 and the wall surface on the side opposite to the recessed portion 33 is formed. A plurality of first passages 121 are formed in the circumferential direction with respect to the axis of the valve body 30.

  The valve member 40 includes a substantially cylindrical shaft portion 41 and a substantially disk-shaped umbrella portion 42 connected to the end portion of the shaft portion 41 on the pressurizing chamber 113 side. The valve member 40 is provided such that the shaft portion 41 is inserted into the first insertion hole 351 of the first guide portion 35 and can reciprocate in the axial direction of the shaft 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 respect to the shaft of the shaft portion 41. The valve member 40 reciprocates to block the fuel flow flowing through the fuel passage 100 when the umbrella portion 42 is seated on the valve seat 34, or flows through the fuel passage 100 when separated from the valve seat 34. Allow fuel flow. Further, the valve member 40 forms an annular second passage 122 between the valve member 40 and 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 part 35 is substantially the same as the diameter of the shaft part 41 of the valve member 40 or slightly larger than the diameter of the shaft part 41. Thus, the valve member 40 reciprocates inside the valve body 30 while the outer wall of the shaft portion 41 slides on the wall surface of the first guide portion 35 that forms the first insertion hole 351. Therefore, when the valve member 40 reciprocates, the reciprocating movement is guided by the first guide portion 35.

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

  The stopper 50 is provided on the pressure member 113 side of the valve member 40. The stopper 50 includes a cylindrical portion 51, a bottom portion 52 that closes an end portion of the cylindrical portion 51 on the counter valve member 40 side, and an annular extended portion 53 that is formed on a 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 extended portion 53 to the inner peripheral wall of the cylindrical portion 32 of the valve body 30.

A third passage 123 that connects the wall surface on the pressurizing chamber 113 side and the wall surface on the anti-pressurizing chamber 113 side of the expanding portion 53 is formed in the expanding portion 53 of the stopper 50. A plurality of third passages 123 are formed in the circumferential direction with respect to the axis of the stopper 50.
Between the second passage 122 and the third passage 123, a substantially annular intermediate passage 124 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 is formed. Yes.
The “substantially annular intermediate passage 124” of the present embodiment corresponds to an example of “substantially annular space” recited in the claims.
The stopper 50 restricts the movement of the valve member 40 in the pressurizing chamber 113 side, that is, in 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 contacts the stopper 50. A tube 55 that connects the volume chamber 54 and 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 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 moves 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 goes 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. One end of the first spring 21 abuts on a first spring seat 46 formed on the umbrella portion 42 of the valve member 40, and the other end is a second spring seat 56 formed on the bottom 52 of the stopper 50. Abut. The first and second spring seats 46 and 56 restrict radial movement at both ends of the first spring 21, respectively. The first spring 21 has a force extending in the axial direction, and urges the valve member 40 toward the counter stopper 50 side, that is, in the valve closing direction.

  A first recess 47 that is recessed toward the valve seat 34 is provided at the end of the valve member 40 on the stopper 50 side. The valve member 40 has a cylindrical protrusion 43 that protrudes toward the stopper 50 on the outer side of the first recess 47. The end of the protruding portion 43 on the stopper 50 side and the end of the cylindrical portion 51 of the stopper 50 on the valve member 40 side can contact each other. The outer edge of the first recess 47 is provided on the inner diameter side of the outer edge of the umbrella part 42 and on the outer diameter side of the outer edge of the second spring seat 56 of the stopper 50. The first spring 21 may be distorted in the radial direction when compressed and contracted between the first spring seat 46 and the second spring seat 56. 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 at 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 face of the valve member 40 on the stopper 50 side. Also, by setting the position of the outer edge of the first recess 47, the contact area between the protruding portion 43 of the valve member 40 and the cylindrical portion 51 of the stopper 50 is set, and ringing between the valve member 40 and the stopper 50 is suppressed. can do. Thereby, the load of the 1st pulling 21 which urges | biases the valve member 40 to a valve opening direction can be set small.

The outer diameter D1 of the end portion of the protruding portion 43 on the stopper 50 side is smaller than the outer diameter D2 of the end portion of the cylindrical portion 51 of the stopper 50 on the valve member 40 side. For this reason, when the valve member 40 is in contact with the stopper 50, the stopper 50 detects that the dynamic pressure of the fuel flow discharged from the pressurizing chamber 113 and flowing through the intermediate passage 124 is applied to the valve member 40 during the metering stroke. Suppress.
For example, a chamfered portion 58 of 0.2 mm on one side is formed in the boundary region between the end surface on the valve member 40 side of the cylindrical portion 51 of the stopper 50 and the outer wall surface in the radially outward direction. The outer diameter D1 of the end portion of the protruding portion 43 on the stopper 50 side is, for example, 0.4 mm smaller than the outer diameter D2 of the end portion of the cylindrical portion 51 of the stopper 50 on the valve member 40 side. Thus, by forming the outer diameter D1 slightly smaller than the outer diameter D2, when the stopper 50 and the valve member 40 come into contact with each other, the fuel flow flowing through the intermediate passage 124 outside the diameter of the stopper 50 is disturbed. This can be suppressed. In addition, when the valve member 40 is seated on the valve seat 34, the umbrella portion 42 of the valve member 40 is stably seated between D1 and D3 of the valve seat 34, so there is no need to reduce the diameter D3 of the recessed portion 33. . Furthermore, since the stopper 50 is slightly larger than the valve member 40, the size of the passage cross-sectional area between D2 and D4 of the intermediate passage 124 can be secured.

As shown in FIG. 4, a chamfered portion 48 is formed in the boundary region between the end surface 401 on the stopper 50 side of the protruding portion 43 and the outer wall surface 402 on the outer diameter side. The length of the chamfered portion 48 in the valve opening direction and the valve closing direction of the valve member 40 is L1. Here, if the length of the chamfered portion 48 in the moving direction of the valve member 40 is formed large as indicated by a broken line L2, the dynamic pressure applied to the valve member 40 by the fuel flow flowing from the third passage 123 through the intermediate passage 124. Becomes larger. In the present embodiment, the dynamic pressure applied to the valve member 40 by the fuel flow flowing from the third passage 123 to the intermediate passage 124 is reduced by forming the length L1 in the moving direction of the valve member 40 smaller than L2. ing.
In FIG. 4, an 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 spool 78 made of resin, and generates a magnetic field when energized. The fixed core 72 is made of a magnetic material. The fixed core 72 is accommodated on the inner peripheral side of the coil 71. The movable core 73 is made 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 made of a 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 made of a magnetic material and is attached to the cylindrical portion 15 of the housing body 11. As a result, the flange 75 holds the electromagnetic drive unit 70 on the housing body 11 and closes the end portion of the cylindrical portion 15. The flange 75 has the 2nd guide part 76 formed in the cylinder shape in the center part. The second guide portion 76 has a second insertion hole 761 that communicates the valve body 30 side and the counter valve body 30 side of the flange 75.

  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 so as to be capable of reciprocating in the axial direction inside the second insertion hole 761. The diameter of the second insertion hole 761 is substantially the same as the diameter of the needle 60 or slightly larger than the diameter of the needle 60. As a result, the needle 60 reciprocates while the outer wall slides on the wall surface of the second guide portion 76 that forms the second insertion hole 761. Therefore, when the needle 60 reciprocates, the reciprocating movement 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. In this way, 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 by sliding with the needle 60 and the 2nd guide part 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 that forms 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. Thereby, the pressure of the valve body 30 side and the counter valve body 30 side of the flange 75 becomes substantially the same. Further, the gap 62 also functions as an air vent passage for air accumulated around the movable core 73.

  One end of the needle 60 is press-fitted or welded to the movable core 73 so as to be integrated with the movable core 73. In addition, the end surface 63 formed at the other end of the needle 60 can abut on the end surface 45 formed at the end of the shaft 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.

  A second spring 22 is provided between the fixed core 72 and the movable core 73. The second spring 22 biases the movable core 73 toward the valve member 40 side. The force with which the second spring 22 biases the movable core 73 is greater than the force with 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. Thereby, 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 to the valve member 40 side by the urging force of the second spring 22, and the valve member 40 is separated from the valve seat 34 of the valve body 30. Sitting.

Next, the operation of the high-pressure pump 10 having the above configuration will be described.
(1) Suction stroke When the plunger 13 moves downward in FIG. 2, energization of the coil 71 is stopped. For this reason, the valve member 40 receives the urging force of the second spring 22 via the needle 60 integrated with the movable core 73 and is separated from the valve seat 34. Further, when the plunger 13 moves downward in FIG. 2, the pressure in the pressurizing 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 that is 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 is separated from the valve seat 34. The valve member 40 moves until the protruding portion 43 comes into contact with the cylindrical portion 51 of the stopper 50. By opening the valve member 40, 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 is in contact with the stopper 50, so that the opening on the pressurizing chamber 113 side of the protrusion 43 is closed by the stopper 50. At this time, the fuel in the intermediate passage 124 can flow into the volume chamber 54 through the pipe 55. Therefore, the pressure in the volume chamber 54 is equivalent to the pressure in the intermediate passage 124.

(2) Metering stroke When the plunger 13 rises from the bottom dead center toward the top dead center, the fuel in the pressurizing chamber 113 is discharged, receives the dynamic pressure, and the valve member 40 has the pressurizing 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 toward the valve seat 34 is restricted by the needle 60. The end of the valve member 40 on the pressurizing 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 that is pressurized in the pressurizing chamber 113 and flows through the intermediate passage 124 is very small and reduced. Thereby, while energization to coil 71 is stopped, valve member 40 maintains the state where it separated from valve seat 34. As a result, the fuel discharged from the pressurizing chamber 113 due to the rise of the plunger 13 is opposite to the case where the fuel is sucked into the pressurizing chamber 113 from the fuel chamber 16, the third passage 123, the intermediate passage 124, the second passage 122 and The fuel is returned to the fuel chamber 16 through the first passage 121 in this order.

  When the coil 71 is energized during the metering process, a magnetic circuit is formed in 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 attractive force is generated between the fixed core 72 and the movable core 73 that are separated from each other. When the magnetic attractive force generated between the fixed core 72 and the movable core 73 becomes larger than the difference between the urging 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 integrated 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 from each other, and the valve member 40 does not receive a 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 urging force of the first spring 21, receives the dynamic pressure of the fuel discharged from the pressurizing chamber 113, and instantaneously moves to the valve seat 34 side.

  When 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, the second passage 122 is closed and the flow of fuel flowing through the fuel passage 100 is blocked. . Thus, the fuel metering process from the pressurizing chamber 113 to the fuel chamber 16 is completed. When the plunger 13 rises, the amount of fuel returned from the pressurizing chamber 113 to the fuel chamber 16 is reduced by closing the second passage 122 and blocking the fuel flow between the pressurizing chamber 113 and the fuel chamber 16. Adjusted.

(3) Pressurization stroke When the plunger 13 rises further toward the top dead center in a state where the pressurization chamber 113 and the fuel chamber 16 are closed, the fuel pressure in the pressurization chamber 113 rises. When the pressure of the fuel in the pressurizing chamber 113 becomes equal to or higher than a predetermined pressure, the pressure is reversed against 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. The stop valve 92 is separated from the valve seat 95. As a result, the discharge valve section 90 is opened, and the fuel pressurized in the pressurizing 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, 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 pressurizing 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 again moves downward in FIG. Thereby, the pressure of the fuel in the pressurizing chamber 113 decreases. Therefore, the valve member 40 is separated from the valve seat 34 again, and fuel is sucked into the pressurizing chamber 113 from the fuel chamber 16.

When the fuel pressure in the pressurizing chamber 113 rises to a predetermined value, the energization to the coil 71 may be stopped. When the fuel pressure in the pressurizing chamber 113 rises, the force received in the direction in which the valve member 40 is seated on the valve seat 34 by the fuel on the pressurizing chamber 113 side is greater than the force that the valve member 40 receives in the direction in which the valve member 40 moves away from the valve seat 34. Become. Therefore, even when energization of the coil 71 is stopped, the valve member 40 maintains the seated state on the valve seat 34 by the force received from the fuel on the pressurizing chamber 113 side. Thus, by stopping energization of the coil 71 at a predetermined time, the power consumption of the electromagnetic drive unit 70 can be reduced.
By repeating the steps (1) to (3), the high-pressure pump 10 pressurizes and discharges the sucked fuel. The fuel discharge amount is adjusted by controlling the timing of energizing 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 formed 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 outer diameter side of the end portion on the stopper 50 side of the protruding portion 43 is formed so that the length L1 of the valve member 40 in the valve opening direction and the valve closing direction is relatively small. For this reason, it can suppress that the dynamic pressure of the fuel flow which is discharged | emitted from the pressurization chamber 113 and flows into the intermediate | middle passage 124 in a metering process applies to a valve member. Accordingly, the valve member 40 is prevented from closing due to the dynamic pressure of the fuel flow, and the load of the second spring 22 that urges the valve member 40 in the valve opening direction via the needle 60 can be set small. . As a result, the current value necessary for the operation of the electromagnetic drive unit 70 that attracts the needle 60 in the valve closing direction against the urging force of the second spring 22 is reduced, and the size of the electromagnetic drive unit 70 is reduced. be able to. Furthermore, by setting the load of the second spring 22 to be small, it is possible to reduce the operating noise caused by the collision between the umbrella portion 42 and the valve seat 34 of the valve member 40 and the protruding portion 43 of the valve member 40 and the stopper 50. it can.

In the present embodiment, a first recess 47 that is recessed toward the valve seat 34 is provided inside the protrusion 43 of the valve member 40. By reducing the area where the stopper-side end of the protrusion 43 of the valve member 40 and the end of the stopper 50 on the valve member 40 side abut, ringing between the valve member 40 and the stopper 50 can be suppressed. it can. Thereby, the load of the 1st spring 21 which urges | biases the valve member 40 to a valve opening direction can be set small.
Further, the outer edge of the first recess 47 is located on the outer diameter side of 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 contact between the inner wall of the first recess 47 of the valve member 40 and the first spring 21. Can be prevented. Furthermore, when the first spring 21 is assembled, contact between the inner wall of the first recess 47 of the valve member 40 and the first spring 21 is suppressed, and 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, a second recess 57 that is recessed on the side opposite to the valve member 40 is provided at the end of the stopper 50 on the valve member 40 side. The outer edge of the second recess 57 is provided on the inner diameter side of the outer edge of the cylindrical portion 51 of the stopper 50 and on the outer diameter side 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 that the first spring 21 contracts and is distorted in the radial direction.

  The first spring 21 of the present embodiment corresponds to an example of an “urging member” recited in the claims.

Therefore, in the present embodiment, when the first spring 21 contracts between the first spring seat 46 and the second spring seat 56 and is distorted in the radial direction, the inner wall of the second recess 57 of the stopper 50 and the first spring 21 are compressed. Contact with the spring 21 can be prevented. Further, when the first spring 21 is assembled, contact between the inner wall of the second recess 57 of the stopper 50 and the first spring 21 is suppressed, and 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, an area where the valve member 40 and the stopper 50 abut can be set, and ringing between the valve member 40 and the stopper 50 can be suppressed. As a result, the load of the first spring 21 that urges the valve member 40 in the valve closing direction can be reduced. Thereby, the load of the second spring 22 that urges the valve member 40 in the valve opening direction against the urging force of the first spring 21 can be set small. As a result, the current value necessary for the operation of the electromagnetic drive unit 0 that attracts the needle 60 in the valve closing direction against the urging force of the second spring 22 can be reduced. Moreover, the physique of the electromagnetic drive part 70 can be reduced in size. Furthermore, it is possible to reduce the operating noise that the valve member 40 and the valve seat 34 and the valve member 40 and the stopper 50 collide with each other.

(Other embodiments)
In the above-described embodiments, the valve member is opened when the coil portion of the electromagnetic drive unit is not energized, and the normally open valve structure is shown in which the valve member is closed when the coil unit is energized. . On the other hand, in other embodiment of this invention, it is good also as a normally closed type valve structure which a valve member opens when it supplies with electricity to a coil part.
As described above, the present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist thereof in addition to combining the first and second embodiments. .

  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 part (valve member), 50: stopper, 51: tube part (stopper), 52 bottom part (stopper), 53: expansion part (stopper), 60: needle, 70: electromagnetic drive part , 71: coil (coil part), 100: fuel passage, 113: pressurizing chamber, 121: first passage (fuel passage), 122: second passage (fuel passage), 123: third passage (fuel passage), 124: Intermediate passage (fuel passage)

Claims (5)

A reciprocating plunger; and
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 pressurizing chamber side;
A valve member that shuts off a fuel flow in a fuel passage by being seated on the valve seat, and allows a fuel flow by being separated from the valve seat;
A stopper having an opposing surface which is a surface facing the surface of the cylindrical member and the pressurizing chamber of the valve member;
An electromagnetic drive unit that is provided on the counter-pressurization chamber side than 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 unit;
An intermediate passage (124) that is a substantially annular space through which the fuel from the pressurizing chamber side to the valve member side can flow, is provided outside the diameter of the cylindrical portion;
The stopper has a plurality of passages (123) communicating the intermediate passage and the pressurizing chamber ,
The high-pressure pump, wherein the intermediate passage is formed between a plurality of the passages and the facing surface. The stopper further includes a bottom portion that closes an end portion of the cylindrical portion on the pressure chamber side,
2. The high-pressure pump according to claim 1, further comprising a biasing member provided between the valve member and the bottom portion inside the cylindrical portion and capable of biasing the valve member in a valve closing direction. .   3. The high-pressure pump according to claim 1, wherein an outer diameter of the cylindrical portion is larger than an outer diameter of an end portion on the stopper side of the valve member.   The high-pressure pump according to claim 1, wherein the stopper is fixed to an inner wall of the fuel passage.   The high-pressure pump according to claim 4, wherein the stopper is fixed to an inner wall of the valve body.

Images