JP5682335B2 - High pressure pump - Google Patents

Description

  The present invention relates to a high-pressure pump that pressurizes and discharges fluid.

2. Description of the Related Art Conventionally, a high-pressure pump is known in which fluid is pumped from a pressurizing chamber pressurized by a reciprocating movement of a plunger via a discharge passage. Fluid is supplied from a fluid supply source connected to the suction passage of the high-pressure pump to the pressurizing chamber through the suction passage.
In such a high-pressure pump, there is a concern that during operation, the pressure pulsation of the fluid due to the pressure fluctuation in the pressurizing chamber is transmitted to the fluid supply source side via the suction passage. When the pressure pulsation from the high-pressure pump is transmitted to the fluid supply source side, there is a risk that abnormal noise may be generated in the passage member connecting the high-pressure pump and the fluid supply source, or the passage member may be damaged. As a countermeasure, the pulsation damper provided in the suction passage of the high-pressure pump is deformed so that the volume of the damper chamber increases or decreases, and the pressure pulsation generated when the high-pressure pump is operated is reduced by reducing the pressure pulsation of the fluid in the suction passage. Suppressing transmission to the supply source side.

International Publication No. 2010/106645 Pamphlet

  In the high-pressure pump disclosed in Patent Document 1, a cover member is provided that forms a fluid chamber between the recess and the recess by closing the opening of the recess formed in the housing. The fluid chamber constitutes a part of the suction passage. The fluid chamber is provided with a damper member that forms a damper chamber with the cover member by being welded to the cover member. In this high-pressure pump, the cover member and the damper member constitute the pulsation damper described above. Here, the damper member has a cylindrical portion and a bottom portion that closes one end portion of the cylindrical portion, and the other end portion of the cylindrical portion is welded to the cover member. Since the cylinder portion of the damper member is formed in a cylindrical shape, when pressure pulsation occurs in the fluid chamber, the volume of the damper chamber increases or decreases mainly due to deformation of only the bottom portion. Therefore, the effect of reducing pressure pulsation by the damper member is relatively low.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a high-pressure pump that is highly effective in reducing fluid pressure pulsation.

The invention described in claim 1 includes a plunger, a housing, a cover member, a suction valve portion, and a damper member. The housing includes a suction port through which fluid is sucked, a recess, a pressurizing chamber in which the inside is pressurized by a reciprocating movement of the plunger, a discharge port from which fluid is discharged, a suction passage that connects the suction port and the inner space of the recess, It has a connection passage that connects the inner space of the recess and the pressurization chamber, and a discharge passage that connects the pressurization chamber and the discharge port. The cover member has a cylindrical cover tube portion and a cover bottom portion that closes one end of the cover tube portion, and is formed in a bottomed tube shape. The cover member is provided so that the other end of the cover tube portion contacts the opening edge of the recess of the housing, thereby forming a fluid chamber between the cover member and the recess. Here, the inner space is included in a fluid chamber. The suction valve portion is provided so as to allow or block the flow of fluid in the connection passage. The damper member has a cylindrical damper cylinder part and a damper bottom part that closes one end of the damper cylinder part. The damper member is provided inside the cover cylinder so that the outer wall of the damper bottom and the inner wall of the cover bottom of the cover member face each other. The damper member forms a damper chamber that is sealed between the cover member and a gas sealed by welding the outer wall of the damper cylinder part and the inner wall of the cover cylinder part. The damper member can reduce the pressure pulsation of the fluid in the fluid chamber by deforming so that the volume of the damper chamber increases or decreases.

And in this invention, a damper cylinder part has a constriction part formed so that it may dent in a radial inside on the damper bottom part side rather than the welding location with a cover cylinder part. Therefore, when reducing the pressure pulsation of the fluid in the fluid chamber, the damper member is easily reciprocated in the axial direction by the deformation of the constricted portion in the axial direction. Thereby, a damper member deform | transforms easily according to the pressure pulsation of a fluid. Therefore, the effect of reducing the pressure pulsation of the fluid by the damper member can be enhanced.
Furthermore, in the present invention, the cover bottom portion of the cover member has a cover recess formed to be recessed toward the side opposite to the damper bottom portion of the damper member. Thereby, the volume of the damper chamber can be further increased. Therefore, the effect of reducing the pressure pulsation of the fluid by the damper member can be further enhanced.

  In the invention according to claim 2, the damper bottom portion of the damper member has a damper recess formed to be recessed toward the opposite side of the cover bottom portion of the cover member. Thereby, the volume of a damper chamber can be enlarged more. Therefore, the effect of reducing the pressure pulsation of the fluid by the damper member can be further enhanced.

  According to a third aspect of the invention, the outer wall extends in a ring shape radially inward from one end portion of the cylindrical portion that contacts the welded portion with the cover cylindrical portion of the inner wall of the damper cylindrical portion. The tube member further includes an annular portion that is formed and has an outer wall that abuts against the constricted portion. As described above, when the damper member reduces the pressure pulsation of the fluid in the fluid chamber, the damper bottom part reciprocates in the axial direction and the constricted part deforms in the axial direction. In the present invention, the cylindrical member is provided such that the annular portion comes into contact with the constricted portion. For this reason, the constriction portion is prevented from being deformed to the side opposite to the axial damper bottom portion. Therefore, damage to the constricted part due to repeated deformation can be suppressed, and the life of the damper member can be extended.

  In the present invention, the cylindrical member is provided so that the outer wall of the cylindrical portion abuts the welded portion with the cover cylindrical portion of the inner wall of the damper cylindrical portion. Therefore, a deformation | transformation to a radial inside is suppressed at the welding location with a cover cylinder part among damper cylinder parts. Therefore, the welding state of the welded part between the damper cylinder part and the cover cylinder part can be kept stable.

Sectional drawing which shows the high pressure pump by 1st Embodiment of this invention. Sectional drawing which shows the damper member of the high pressure pump by 1st Embodiment of this invention, and its vicinity. The perspective view which shows the damper member of the high pressure pump by 1st Embodiment of this invention. Sectional drawing which shows the damper member of the high pressure pump by 2nd Embodiment of this invention, and its vicinity. Sectional drawing which shows the damper member of the high pressure pump by 3rd Embodiment of this invention, and its vicinity.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.

(First embodiment)
A high-pressure pump according to a first embodiment of the present invention is shown in FIG. The high-pressure pump 1 is a fuel pump that supplies fuel as a fluid to an injector of, for example, a diesel engine or a gasoline engine. For example, the high pressure pump 1 sucks fuel from a fuel tank (not shown) and discharges it to a delivery pipe (not shown). Thereby, the fuel in the delivery pipe is accumulated and injected and supplied to the engine from the injector connected to the delivery pipe.

  The high-pressure pump 1 includes a plunger 20, a housing 30, a cover member 40, a suction valve unit 50, a damper member 70, and the like. The plunger 20 is formed of a metal into a solid cylindrical shape. The plunger 20 includes a large diameter portion 21 and a small diameter portion 22. The small diameter portion 22 is formed so as to extend in the axial direction from the center of the end of the large diameter portion 21, and the outer diameter is smaller than the outer diameter of the large diameter portion 21.

  The housing 30 is made of, for example, a metal such as stainless steel, and includes a suction port 31, a recess 32, a pressurizing chamber 33, a discharge port 34, a suction passage 35, a connection passage 36, a discharge passage 37, and the like. The recess 32 is formed, for example, by cutting the outer wall of a member that forms the housing 30. Thereby, a substantially cylindrical inner space 321 is formed inside the recess 32. The pressurizing chamber 33 is formed in the approximate center of the housing 30. A cylinder portion 38 having a cylindrical inner wall is formed on the opposite side of the pressurizing chamber 33 of the housing 30 from the concave portion 32. The inner space of the cylinder portion 38 is connected to the pressurizing chamber 33. The inner diameter of the cylinder portion 38 is slightly larger than the outer diameter of the large diameter portion 21 of the plunger 20. Thereby, the cylinder part 38 is slidable with the large diameter part 21, and is supporting the plunger 20 so that reciprocation is possible to an axial direction.

The suction passage 35 is formed to connect the suction port 31 and the inner space 321 of the recess 32. The connection passage 36 is formed to connect the inner space 321 of the recess 32 and the pressurizing chamber 33. The connection passage 36 includes a first connection passage 361 connected to the inner space 321 and a second connection passage 362 connected to the pressurizing chamber 33. The discharge passage 37 is formed so as to connect the pressurizing chamber 33 and the discharge port 34. Thus, the suction port 31 communicates with the discharge port 34 via the suction passage 35, the inner space 321, the connection passage 36, the pressurizing chamber 33 and the discharge passage 37. Thus, the fuel that has flowed into the housing 30 from the suction port 31 can flow out from the discharge port 34.
The suction port 31 is connected to a low-pressure fuel pipe that communicates with a low-pressure fuel pump that pumps up fuel in the fuel tank. The discharge port 34 is connected to a high-pressure fuel pipe communicating with the delivery pipe.

  The cover member 40 is formed in a bottomed cylindrical shape using a metal such as stainless steel. The cover member 40 includes a cover tube portion 41 and a cover bottom portion 42. The cover cylinder part 41 is formed in a substantially cylindrical shape. The cover bottom portion 42 closes one end portion of the cover cylinder portion 41. The cover member 40 is provided so that the end of the cover cylinder part 41 opposite to the cover bottom part 42 abuts against the opening edge 322 of the recess 32 of the housing 30, so that the cover member 40 has a substantially cylindrical shape between the cover member 40 and the recess 32. A fluid chamber 100 is formed. Here, the fluid chamber 100 includes an inner space 321. Moreover, the edge part on the opposite side to the cover bottom part 42 of the cover cylinder part 41 and the opening edge part 322 are welded over the perimeter. Thereby, the inner side and the outer side of the fluid chamber 100 are kept liquid-tight.

The suction valve unit 50 is provided in the second connection passage 362. Hereinafter, a more specific configuration of the intake valve unit 50 will be described. The suction valve unit 50 includes a valve body 51, a suction valve 52, a locking member 53, a stopper 54, a spring 55, and the like.
The valve body 51 is formed in a bottomed cylindrical shape, and is provided at a location away from the pressurizing chamber 33 by a predetermined distance in the second connection passage 362. The valve body 51 has a cylindrical portion 511 and a bottom portion 512. The bottom 512 closes the end of the cylinder 511 opposite to the pressurizing chamber 33. The bottom portion 512 is formed with a plurality of through holes 513 through which fuel can flow.

  The suction valve 52 includes a shaft portion 521 and an umbrella portion 522, and the shaft portion 521 is slidably supported by a hole formed in the bottom portion 512 of the valve body 51. Thereby, the suction valve 52 can reciprocate in the axial direction. The umbrella portion 522 can contact a valve seat formed on the outer periphery of the through hole 513 on the side wall surface of the pressure chamber 33 of the bottom portion 512. The suction valve 52 can allow or block the flow of fuel in the through hole 513, that is, the flow of fuel in the second connection passage 362, when the umbrella portion 522 is separated from the valve seat or abuts against the valve seat.

  The locking member 53 is formed in an annular shape, and is fitted in a groove formed in the inner wall of the housing 30 that forms the second connection passage 362. The locking member 53 restricts the movement of the valve body 51 to the side opposite to the pressurizing chamber 33 by locking the end of the valve body 51 on the bottom 512 side. Thereby, the valve body 51 is prevented from coming off to the side opposite to the pressurizing chamber 33.

The stopper 54 is provided inside the cylinder portion 511 of the valve body 51, that is, on the pressure chamber 33 side of the bottom portion 512. The stopper 54 restricts the movement of the suction valve 52 toward the pressurizing chamber 33 when the umbrella portion 522 comes into contact therewith. The stopper 54 is formed with a plurality of through holes that connect the bottom 512 side of the stopper 54 and the pressurizing chamber 33 side.
The spring 55 is provided between the umbrella portion 522 and the stopper 54 and biases the suction valve 52 to the side opposite to the pressurizing chamber 33.

  An electromagnetic driving unit 60 is provided on the side of the suction valve unit 50 opposite to the pressurizing chamber 33. The electromagnetic drive unit 60 includes a needle 61, a movable core 62, a fixed core 63, a coil 64, a spring 65, and the like. The needle 61 is supported by a hole formed in the housing 30 so as to be reciprocally movable. One end of the needle 61 can abut on the end of the suction valve 52 opposite to the umbrella 522 of the shaft 521. The movable core 62 is made of a magnetic material and is attached to the other end of the needle 61. The fixed core 63 is made of a magnetic material, and is fixed to the side of the movable core 62 opposite to the pressurizing chamber 33. The coil 64 is provided on the radially outer side of the fixed core 63, and generates a magnetic field when electric power is supplied from the outside via the terminal 641. When a magnetic field is generated in the coil 64, a magnetic circuit is formed in the fixed core 63 and the movable core 62, and the movable core 62 is attracted to the fixed core 63 side together with the needle 61.

The spring 65 is provided between the movable core 62 and the fixed core 63, and biases the movable core 62 and the needle 61 toward the pressurizing chamber 33. Here, the biasing force of the spring 65 is set larger than the biasing force of the spring 55. Therefore, when power is not supplied to the coil 64, the suction valve 52 is urged toward the pressurizing chamber 33 by the urging force of the spring 65 via the movable core 62 and the needle 61 and comes into contact with the stopper 54. It becomes a state. At this time, since the umbrella portion 522 of the intake valve 52 is separated from the valve seat of the valve body 51, the fuel flow in the second connection passage 362 is allowed. On the other hand, when the movable core 62 and the needle 61 are sucked toward the fixed core 63 by supplying electric power to the coil 64, the suction valve 52 is biased by the biasing force of the spring 55 and the like, and the pressurizing chamber 33. Moves to the opposite side, and the umbrella portion 522 contacts the valve seat of the valve body 51. Thereby, the flow of fuel in the second connection passage 362 is blocked.
As described above, the intake valve section 50 can allow or block the flow of fuel in the connection passage 36 by the operation of the electromagnetic drive section 60. In the present embodiment, the electromagnetic drive unit 60 and the suction valve unit 50 constitute a so-called normally open type valve device.

  As shown in FIGS. 2 and 3, the damper member 70 is formed in a bottomed cylindrical shape. The damper member 70 is formed by, for example, pressing a metal plate such as stainless steel. The damper member 70 has a damper cylinder portion 71 and a damper bottom portion 72. The damper cylinder portion 71 is formed in a substantially cylindrical shape. The damper bottom portion 72 closes one end portion of the damper cylinder portion 71. The damper member 70 is provided inside the cover cylinder portion 41 so that the outer wall of the damper bottom portion 72 and the inner wall of the cover bottom portion 42 face each other. That is, the damper member 70 is provided so as to be inserted into the cover cylinder portion 41 from the end portion on the damper bottom portion 72 side. The damper member 70 forms a sealed damper chamber 73 with the cover member 40 by welding the outer wall of the damper cylinder part 71 and the inner wall of the cover cylinder part 41 over the entire circumference. The damper chamber 73 is filled with, for example, helium gas or argon gas, or a mixed gas thereof. The damper member 70 can reduce the pressure pulsation of the fuel generated in the fluid chamber 100 by deforming so that the volume of the damper chamber 73 increases or decreases.

  The damper cylinder part 71 has a constricted part 711 formed so as to be recessed radially inward over the entire circumference on the damper bottom 72 side of the welded part W with the cover cylinder part 41. The damper bottom 72 has a damper recess 721 formed so as to be recessed toward the side opposite to the cover bottom 42. The damper recess 721 is formed in a circular shape and has a flat portion 722 on the radially inner side. Further, the damper bottom portion 72 has an annular flat portion 723 on the radially outer side of the damper recess 721.

The outer diameter of the damper bottom part 72 is smaller than the inner diameter of the cover cylinder part 41. Therefore, an annular gap is formed between the outer edge portion of the damper bottom portion 72 and the inner wall of the cover cylinder portion 41. Moreover, in this embodiment, the connection location of the damper cylinder part 71 and the damper bottom part 72 is formed so that it may curve smoothly.
In the present embodiment, the cover bottom 42 has a cover recess 421 formed so as to be recessed stepwise toward the side opposite to the damper bottom 72.

  As shown in FIG. 1, a discharge valve portion 80 is provided in the discharge passage 37 of the housing 30. The discharge valve unit 80 includes a discharge valve 81, a cylindrical member 82, and a spring 83. The discharge valve 81 is formed in a bottomed cylindrical shape, and an end on the bottom side can contact a valve seat formed on the inner wall of the housing 30. The discharge valve 81 has a plurality of through holes. The cylindrical tube member 82 is provided on the opposite side of the discharge valve 81 from the pressurizing chamber 33. The cylindrical member 82 is press-fitted and fixed to the inner wall that forms the discharge passage 37 of the housing 30. The spring 83 is provided between the bottom of the discharge valve 81 and the cylindrical member 82, and biases the discharge valve 81 toward the pressurizing chamber 33.

  The spring seat 11 is attached to the end of the plunger 20 opposite to the large diameter portion 21 of the small diameter portion 22. A spring 12 is provided between the spring seat 11 and the housing 30. The spring 12 biases the spring seat 11 toward a cam (not shown). The plunger 20 is in contact with a cam via a tappet (not shown), and is driven to reciprocate in the axial direction as the cam rotates.

  A seal member 13 and an oil seal 14 are provided on the outer periphery of the small diameter portion 22 of the plunger 20 in the housing 30. The seal member 13 adjusts the thickness of the fuel oil film around the small diameter portion 22 and suppresses fuel leakage to the engine due to the sliding of the plunger 20. The oil seal 14 regulates the thickness of the oil film around the small-diameter portion 22 and suppresses oil leakage due to sliding of the plunger 20.

Next, the operation of the high pressure pump 1 of the present embodiment will be described.
"Inhalation stroke"
When the plunger 20 moves downward in FIG. 1, the energization of the coil 64 is stopped. Therefore, the suction valve 52 is urged toward the pressurizing chamber 33 by the needle 61 integral with the movable core 62 receiving a force from the spring 65 of the electromagnetic drive unit 60. As a result, the suction valve 52 is separated from the valve seat of the valve body 51. Further, when the plunger 20 moves downward in FIG. 1, the pressure in the pressurizing chamber 33 decreases. Therefore, the force received by the intake valve 52 from the fuel on the bottom 512 side of the valve body 51 is greater than the force received from the fuel on the pressurizing chamber 33 side. Thereby, a force is applied to the suction valve 52 in a direction away from the valve seat, and the suction valve 52 moves until it comes into contact with the stopper 54. When the suction valve 52 is separated from the valve seat, that is, opens, the fluid chamber 100 communicates with the pressurizing chamber 33 via the first connection passage 361 and the second connection passage 362. Therefore, the fuel in the fluid chamber 100 is sucked into the pressurizing chamber 33 through the first connection passage 361 and the second connection passage 362 in this order.

“Weighing process”
When the plunger 20 rises from the bottom dead center toward the top dead center, the suction valve 52 has a pressure chamber 33 side due to the flow of fuel discharged from the pressure chamber 33 to the suction valve 52 side, that is, the fluid chamber 100 side. Force is applied from the fuel in the direction of seating on the valve seat. However, when the coil 64 is not energized, the needle 61 is biased toward the suction valve 52 by the biasing force of the spring 65. Therefore, the movement of the suction valve 52 to the valve seat side is restricted by the needle 61. The suction valve 52 is covered with a stopper 54 on the pressurizing chamber 33 side. Thus, the flow of fuel discharged from the pressurizing chamber 33 toward the fluid chamber 100 does not directly collide with the intake valve 52. Therefore, the force in the valve closing direction applied to the intake valve 52 by the flow of fuel is alleviated.

In the metering stroke, the suction valve 52 is kept away from the valve seat while the power supply to the coil 64 is stopped. As a result, the fuel discharged from the pressurizing chamber 33 as the plunger 20 moves up is passed through the second connection passage 362 and the first connection passage 361 in this order, contrary to the case where the fuel is sucked from the fluid chamber 100 into the pressurization chamber 33. To return to the fluid chamber 100.
When the coil 64 is energized during the metering process, a magnetic circuit is formed in the fixed core 63 and the movable core 62 by the magnetic field generated in the coil 64. Thereby, a magnetic attraction force is generated between the fixed core 63 and the movable core 62 that are separated from each other. When the magnetic attractive force generated between the fixed core 63 and the movable core 62 becomes larger than the urging force of the spring 65, the movable core 62 moves to the fixed core 63 side. Therefore, the needle 61 integral with the movable core 62 also moves to the fixed core 63 side. When the needle 61 moves toward the fixed core 63, the suction valve 52 and the needle 61 are separated from each other, and the suction valve 52 does not receive a force from the needle 61. As a result, the suction valve 52 is separated from the stopper 54 by the biasing force of the spring 55 and the force in the valve closing direction applied to the suction valve 52 by the flow of fuel discharged from the pressurizing chamber 33 to the fluid chamber 100 side. Move to the seat side. As a result, the suction valve 52 is closed.

  When the plunger 20 moves up, the amount of fuel returned from the pressurizing chamber 33 to the fluid chamber 100 is adjusted by closing the through hole 513, that is, between the pressurizing chamber 33 and the fluid chamber 100. As a result, the amount of fuel pressurized in the pressurizing chamber 33 is determined. When the suction valve 52 moves to the valve seat side and the suction valve 52 abuts on the valve seat, that is, closes, the through hole 513 is closed, and the flow of fuel flowing through the connection passage 36 is blocked. Thereby, the metering process of discharging the fuel from the pressurizing chamber 33 to the fluid chamber 100 ends.

"Pressure stroke"
When the plunger 20 further rises toward the top dead center in a state where the pressurizing chamber 33 and the fluid chamber 100 are closed, the fuel pressure in the pressurizing chamber 33 rises. When the fuel pressure in the pressurizing chamber 33 becomes equal to or higher than a predetermined pressure, the discharge valve 81 resists the biasing force of the spring 83 of the discharge valve portion 80 and the force received by the discharge valve 81 from the fuel downstream of the valve seat. Separate from the valve seat. As a result, the discharge valve unit 80 is opened, and the fuel pressurized in the pressurizing chamber 33 passes through the discharge passage 37 and is discharged from the high-pressure pump 1. The fuel discharged from the high-pressure pump 1 is supplied to a delivery pipe (not shown), accumulated, and supplied to the injector.

  When the plunger 20 moves to the top dead center, the power supply to the coil 64 is stopped, and the suction valve 52 is separated from the valve seat again. At this time, the plunger 20 again moves downward in FIG. 1, and the fuel pressure in the pressurizing chamber 33 decreases. As a result, fuel is sucked into the pressurizing chamber 33 from the fluid chamber 100.

  When the suction valve 52 is closed and the fuel pressure in the pressurizing chamber 33 rises to a predetermined value, the energization of the coil 64 may be stopped. When the pressure of the fuel in the pressurizing chamber 33 rises, the force received in the direction in which the suction valve 52 abuts the valve seat by the fuel on the pressurizing chamber 33 side becomes larger than the force that the suction valve 52 receives in the direction away from the valve seat. Therefore, even if the energization to the coil 64 is stopped, the suction valve 52 maintains the contact state with the valve seat by the force received from the fuel on the pressurizing chamber 33 side. Thus, by stopping energization of the coil 64 at a predetermined time, the power consumption of the electromagnetic drive unit 60 can be reduced.

By repeating the above “intake stroke”, “metering stroke”, and “pressurization stroke”, the high pressure pump 1 pressurizes and discharges the sucked fuel. The fuel discharge amount is adjusted by controlling the timing of energizing the coil 64 of the electromagnetic drive unit 60.
During the operation of the high-pressure pump 1, the “intake stroke”, “metering stroke”, and “pressurization stroke” are repeated, whereby the pressure in the pressurizing chamber 33 fluctuates periodically. Therefore, fuel pressure pulsation occurs in the fluid chamber 100 communicating with the pressurizing chamber 33. In this embodiment, the damper chamber 73 is formed by providing the damper member 70 in the fluid chamber 100. The damper member 70 is deformed so that the volume of the damper chamber 73 increases or decreases, thereby reducing the pressure pulsation of the fuel generated in the fluid chamber 100 when the high-pressure pump 1 is operated.

  As described above, in the present embodiment, the damper member 70 is sealed between the cover member 40 and the damper chamber 73 by welding the outer wall of the damper cylinder part 71 and the inner wall of the cover cylinder part 41. Is forming. The damper member 70 can reduce the pressure pulsation of the fuel in the fluid chamber 100 by deforming so that the volume of the damper chamber 73 increases or decreases. Thereby, it is suppressed that the pressure pulsation of the fuel in the fluid chamber 100 is transmitted to the low-pressure fuel pipe side, and damage to the low-pressure fuel pipe can be prevented.

  Further, in the present embodiment, the damper cylinder portion 71 of the damper member 70 has a constricted portion 711 formed to be recessed inward in the radial direction on the damper bottom portion 72 side than the welded portion W with the cover cylinder portion 41. Yes. Therefore, when the damper member 70 reduces the pressure pulsation of the fuel in the fluid chamber 100, the damper bottom portion 72 is easily reciprocated in the axial direction by deforming the constricted portion 711 in the axial direction. Thereby, the damper member 70 is easily deformed in accordance with the pressure pulsation of the fuel. Therefore, the effect of reducing the pressure pulsation of the fuel by the damper member 70 can be enhanced.

  Further, in the present embodiment, the damper bottom portion 72 of the damper member 70 has a damper recess 721 formed so as to be recessed toward the opposite side of the cover bottom portion 42 of the cover member 40. Thereby, the volume of the damper chamber 73 can be made larger. Therefore, the effect of reducing the pressure pulsation of the fuel by the damper member 70 can be further enhanced.

  In the present embodiment, the cover bottom portion 42 of the cover member 40 has a cover recess 421 formed to be recessed toward the side opposite to the damper bottom portion 72 of the damper member 70. Thereby, the volume of the damper chamber 73 can be further increased. Therefore, the effect of reducing the pressure pulsation of the fuel by the damper member 70 can be further enhanced.

(Second Embodiment)
A part of the high-pressure pump according to the second embodiment of the present invention is shown in FIG. The second embodiment is different from the first embodiment in that the number of elements constituting the high-pressure pump is one more.

  The second embodiment further includes a cylindrical member 90. The cylindrical member 90 is formed in a substantially cylindrical shape from a metal such as stainless steel, and is installed on the opposite side of the damper member 70 from the cover bottom 42 in the fluid chamber 100.

  The tubular member 90 has a tubular portion 91, an annular portion 92, and an extended tubular portion 93. The cylindrical portion 91 is formed in a cylindrical shape, and the outer wall is in contact with the welded portion W with the cover cylindrical portion 41 in the inner wall of the damper cylindrical portion 71. The annular portion 92 is formed so as to extend annularly from one end portion of the cylindrical portion 91 radially inward, and the outer wall is in contact with the constricted portion 711. Further, the annular portion 92 is formed thicker than the damper member 70.

  The extending cylindrical portion 93 is formed in a cylindrical shape so as to extend from the cylindrical portion 91, and the end portion is in contact with the bottom surface of the concave portion 32 of the housing 30. Moreover, the extending | stretching cylinder part 93 is formed so that it may become thick radially outside the cylinder part 91, as shown in FIG. Therefore, the extending cylinder portion 93 is in contact with the sidewall of the recess 32 at the outer wall. Further, a hole 931 is formed at a location corresponding to the first connection passage 361 of the extending cylinder portion 93. Thereby, the fuel can flow between the fluid chamber 100 and the first connection passage 361 via the hole 931.

  As described above, in the present embodiment, the outer wall has a diameter from the cylindrical portion 91 that contacts the welded portion W with the cover cylindrical portion 41 in the inner wall of the damper cylindrical portion 71, and one end portion of the cylindrical portion 91. The tube member 90 further includes an annular portion 92 that is formed so as to extend annularly inward in the direction and whose outer wall abuts against the constricted portion 711. As described in the first embodiment, when the damper member 70 reduces the pressure pulsation of the fuel in the fluid chamber 100, the damper bottom portion 72 reciprocates in the axial direction and the constricted portion 711 deforms in the axial direction. In the present embodiment, the cylindrical member 90 is provided such that the annular portion 92 contacts the constricted portion 711. Therefore, the constriction 711 is prevented from being deformed to the side opposite to the axial damper bottom 72. Therefore, damage to the constricted portion 711 due to repeated deformation can be suppressed, and the life of the damper member 70 can be extended.

  Further, in the present embodiment, the cylindrical member 90 is provided so that the outer wall of the cylindrical portion 91 abuts the welded portion W with the cover cylindrical portion 41 in the inner wall of the damper cylindrical portion 71. Therefore, the welding part W with the cover cylinder part 41 among the damper cylinder parts 71 is suppressed from deforming radially inward. Therefore, the welding state of the welded portion W between the damper cylinder portion 71 and the cover cylinder portion 41 can be kept stable.

(Third embodiment)
A part of the high-pressure pump according to the third embodiment of the present invention is shown in FIG. The third embodiment is different from the second embodiment in the configuration of the cylindrical member.

In the third embodiment, the cylindrical member 95 includes only the cylindrical portion 91 and the annular portion 92. That is, the cylindrical member 95 has a shape obtained by removing the extended cylindrical portion 93 from the cylindrical member 90 of the second embodiment.
In the present embodiment, the cover member 40 includes an extending cylinder portion 43 that extends from the cover cylinder portion 41 in a cylindrical shape. The extending cylindrical portion 43 is welded to the outer wall on the radially outer side of the concave portion 32 (inner space 321) of the housing 30 over the entire circumference.
In the present embodiment, the inner diameter of the concave portion 32 is smaller than the inner diameter of the cover cylinder portion 41. The end of the damper cylinder 71 of the damper member 70 and the end of the cylinder 91 of the cylinder member 95 are in contact with the opening edge 322 of the recess 32 of the housing 30.

  As described above, in the present embodiment, the outer wall has a diameter from the cylindrical portion 91 that contacts the welded portion W with the cover cylindrical portion 41 in the inner wall of the damper cylindrical portion 71, and one end portion of the cylindrical portion 91. A cylindrical member 95 having an annular portion 92 formed so as to extend annularly inward in the direction and having an outer wall abutting the constricted portion 711 is provided. Thereby, there can exist an effect similar to 2nd Embodiment.

(Other embodiments)
In the above-mentioned embodiment, the example which has a damper recessed part formed so that a damper bottom part may be dented on the opposite side to a cover bottom part was shown. On the other hand, in another embodiment of the present invention, the damper bottom may not have a damper recess, that is, the damper bottom may be formed in a planar shape.

  Moreover, in the above-mentioned embodiment, the cover bottom part showed the example which has a cover recessed part formed so that it might dent toward the opposite side to a damper bottom part. On the other hand, in other embodiment of this invention, it is good also as a structure in which a cover bottom part does not have a cover recessed part, ie, a cover bottom part is formed in planar shape.

Moreover, in other embodiment of this invention, it is good also as a structure which does not provide a discharge valve part.
In another embodiment of the present invention, the electromagnetic drive unit may not be provided. In the case of this configuration, for example, if a check valve is installed in the suction valve section that allows fluid flow from the suction passage side to the pressurization chamber side and restricts flow from the pressurization chamber side to the suction passage side. Good.

In the above-mentioned embodiment, the example which uses a high-pressure pump as a fuel pump for internal combustion engines was shown. On the other hand, in another embodiment of the present invention, the high-pressure pump can be used as a pump that pressurizes and discharges a fluid other than fuel, for example, water or oil.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... High pressure pump 20 ... Plunger 30 ... Housing 31 ... Intake port 32 ... Recess 321 ... Inner space 322 ... Opening edge 33 ... · Pressurizing chamber 34 ··· Discharge port 35 ··· Suction passage 36 ··· Connection passage 361 ··· First connection passage (connection passage)
362 ... second connection passage (connection passage)
37 ··· discharge passage 40 ··· cover member 41 ··· cover cylinder portion 42 ··· cover bottom portion 50 ··· suction valve portion 70 ··· damper member 71 ··· damper Tube portion 711 ... Constriction portion 72 ... Damper bottom 73 ... Damper chamber 100 ... Fluid chamber W ... Welding location

Claims (3)

A plunger,
A suction port through which fluid is sucked, a recess, a pressurizing chamber in which the inside is pressurized by reciprocating movement of the plunger, a discharge port from which fluid is discharged, a suction passage connecting the suction port and the inner space of the recess, A connection passage connecting the inner space of the recess and the pressurization chamber, and a housing having a discharge passage connecting the pressurization chamber and the discharge port;
By having a cylindrical cover tube portion and a cover bottom portion that closes one end portion of the cover tube portion, the other end portion of the cover tube portion is provided so as to contact the opening edge of the recess. A bottomed cylindrical cover member that forms a fluid chamber including the inner space with the recess;
A suction valve portion provided to allow or block the flow of fluid in the connection passage;
A cylindrical damper cylinder and a damper bottom that closes one end of the damper cylinder are provided inside the cover cylinder so that the outer wall of the damper bottom faces the inner wall of the cover bottom And the outer wall of the damper cylinder part and the inner wall of the cover cylinder part are welded to form a damper chamber sealed between the cover member and filled with gas , and the volume of the damper chamber increases or decreases. A damper member capable of reducing the pressure pulsation of the fluid in the fluid chamber by deforming in such a manner,
The damper cylinder unit, the damper bottom side than the welded portion between the cover cylinder portion, have a constricted portion formed as recessed radially inward,
The cover bottom, the high-pressure pump, characterized by chromatic said cover recess formed as recessed toward the side opposite to the damper base.   The high-pressure pump according to claim 1, wherein the damper bottom portion has a damper recess formed to be recessed toward a side opposite to the cover bottom portion.   The outer wall is formed so as to annularly extend radially inward from one end portion of the cylindrical portion, and the outer wall is formed in the constricted portion, the cylindrical portion coming into contact with the welded portion with the cover cylindrical portion of the inner wall of the damper cylindrical portion The high-pressure pump according to claim 1, further comprising a cylindrical member having an annular portion that comes into contact with the cylinder.

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