JP6583514B2 - High pressure pump - Google Patents

Description

  The present invention relates to a high-pressure pump using a relief valve that can reduce the pressure of fuel in a space.

  Conventionally, there is known a relief valve that can reduce the pressure of the fluid in the space when the pressure of the fluid in the space exceeds a predetermined value. For example, the relief valve described in Patent Document 1 is provided so as to be connected to a discharge passage of a high-pressure pump. When the pressure of the fuel in the discharge passage exceeds a predetermined value, the relief valve returns the fuel in the discharge passage to the pressurizing chamber side of the high-pressure pump and reduces the pressure of the fuel in the discharge passage.

JP2013-241835A

  The relief valve of Patent Document 1 includes a spherical valve body and a movable holder that holds the valve body. The movable holder can reciprocate in the guide hole together with the valve body while sliding on the inner wall of the cylindrical guide hole. Moreover, the relief valve of patent document 1 is provided with the urging member which urges | biases a valve body to the valve seat side with the said movable holder. The valve opening pressure, which is the pressure when the valve body leaves the valve seat, is set based on the urging force of the urging member.

  Here, the area of the minimum gap between the movable holder and the guide hole, that is, the minimum flow path area between the pressure chamber side space of the movable holder and the pressure chamber side space of the high pressure pump is When the movable holder moves away from the valve seat and exceeds a predetermined position, it is set discontinuously so as to increase suddenly. Therefore, when the pressure of the fuel in the discharge passage exceeds the valve opening pressure of the valve body and the valve body opens, the pressure of the fuel in the pressure chamber increases, and the movable holder moves in a direction away from the valve seat together with the valve body. . When the position of the movable holder exceeds the predetermined position, a relatively large amount of fuel flows from the pressure chamber to the space on the pressurizing chamber side via the gap between the movable holder and the guide hole. Thereby, the pressure of the fuel in the discharge passage is quickly reduced.

  By the way, in the relief valve of Patent Document 1, the minimum flow path area between the pressure chamber and the space on the pressurizing chamber side suddenly moves when the movable holder moves toward the valve seat and exceeds the predetermined position. It can be said that it is set to be discontinuous so as to decrease. For this reason, even if the pressure is reduced by the flow of fuel from the pressure chamber to the space on the pressurizing chamber side, the pressure chamber moves in the direction in which the movable holder approaches the valve seat and exceeds the predetermined position. The fuel flow to the side space is suddenly throttled, and the pressure suddenly increases again. As a result, the fuel in the pressure chamber repeatedly decreases and increases in pressure, and there is a risk that pressure pulsation will occur in the fuel in the discharge passage communicating with the pressure chamber. When pressure pulsation occurs in the fuel in the discharge passage, there is a possibility that a member forming a space communicating with the discharge passage may be damaged.

  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 using a relief valve that can suppress the pulsation of the fuel pressure in the space when the pressure of the fuel in the space is reduced. To provide a pump.

  A high-pressure pump according to the present invention is provided so as to be connected to a first space and a second space which is a space different from the first space, and a relief valve and a housing capable of reducing fuel pressure in the first space. Is provided. The relief valve has a body portion, a valve seat portion, a valve member, and an urging member.

  The body portion includes a cylindrical inner wall that is a cylindrical inner wall, a first hole portion that is formed so as to connect the inner space that is a space inside the cylindrical inner wall and the second space, the inner space and the second space. It has the 2nd hole formed in the location different from a 1st hole so that it may connect, and the hole opening which is opening of the 1st hole formed in the cylindrical inner wall. The valve seat portion is formed in an annular shape outside the diameter of the valve hole formed so as to close one end of the cylindrical inner wall and connect the inner space and the first space, and the inner space side end portion of the valve hole. Has a valve seat.

The valve member is formed on the valve body provided to be reciprocally movable in the inner space in the axial direction, on the sliding outer wall that slides on the cylindrical inner wall of the outer wall of the valve body, and on the valve seat side of the valve body And a seat portion capable of contacting the valve seat. The valve member forms an intermediate chamber between the cylindrical inner wall and the valve seat portion, the volume of which changes according to the axial position of the valve body with respect to the cylindrical inner wall and which can communicate with the valve hole and the first hole portion. The valve member communicates the valve hole and the intermediate chamber when the seat portion is separated from the valve seat, and shuts off the valve hole and the intermediate chamber when the seat portion contacts the valve seat. Thus, the valve member allows the flow of fuel between the valve hole and the intermediate chamber when the seat portion is separated from the valve seat, and the fuel between the valve hole and the intermediate chamber when the seat portion contacts the valve seat. Regulate the flow of The urging member urges the valve member toward the valve seat portion.
The housing has a pressurizing chamber that sucks and pressurizes fuel, an intake passage through which fuel sucked into the pressurizing chamber flows, and a discharge passage through which fuel pressurized and discharged in the pressurizing chamber flows.

  In the present invention, the valve member has an overlapping area that is an area in which the hole opening and the sliding outer wall overlap as the valve member moves in a direction away from the valve seat portion at least within the axially movable range. It includes a “specific range in which the minimum flow path area, which is the minimum flow path area between the intermediate chamber and the first hole portion, gradually increases as it decreases.

  In the present invention, when the pressure of the fuel in the first space becomes equal to or higher than the valve opening pressure of the valve member, the seat portion is opened away from the valve seat. Accordingly, when the pressure of the fuel in the intermediate chamber communicating with the first space increases, the valve member moves in a direction away from the valve seat portion. In a specific range, the farther the valve member is from the valve seat portion, the larger the minimum flow path area between the intermediate chamber and the hole portion. Therefore, the higher the fuel pressure in the intermediate chamber, the higher the fuel flowing from the intermediate chamber to the hole portion. The flow rate increases. Thereby, the pressure of the fuel in the first space communicating with the intermediate chamber can be quickly reduced.

Further, in the present invention, when the valve member moves in a direction approaching the valve seat portion, the overlapping area of the hole opening and the sliding outer wall gradually increases in a specific range, and the space between the intermediate chamber and the hole portion is increased. The minimum flow path area is gradually reduced. Therefore, when the fuel flows from the intermediate chamber to the hole, the pressure of the fuel in the intermediate chamber decreases, and when the valve member moves to the valve seat side, the flow of fuel from the intermediate chamber to the hole is gradually reduced. . Thereby, “the fuel flow from the intermediate chamber to the hole is suddenly throttled and the pressure of the fuel in the intermediate chamber suddenly increases again” is suppressed. Therefore, when reducing the pressure of the fuel in the first space, it is possible to suppress the occurrence of pressure pulsation in the fuel in the intermediate chamber and the fuel in the first space communicating with the intermediate chamber.
In the present invention, the first space is a space in the discharge passage or a space communicating with the discharge passage. The second space is a space including a pressurizing chamber. The second hole portion is formed so as to connect the space on the opposite side of the intermediate chamber to the valve body in the inner space and the second space.

It is sectional drawing of the relief valve by 1st Embodiment of this invention, Comprising: (A) is a figure which shows the state which the seat part is contact | abutting to the valve seat, (B) is separated from the valve seat. The figure which shows a state. The schematic diagram which shows the state which applied the relief valve by 1st Embodiment of this invention to the high pressure pump of a vehicle. The perspective view of the partial cross section which shows the state which applied the relief valve by 1st Embodiment of this invention to the high pressure pump of a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the hole part vicinity of the relief valve by 1st Embodiment of this invention, Comprising: (A) is a figure which shows the state which the seat part is contact | abutting to the valve seat, (B) is a seat part from a valve seat. The figure which shows the state which has isolate | separated, (C) is a figure which shows the state which the sheet | seat part is spaced apart from a valve seat, and the valve member is contact | abutting to the movement control part. It is a figure for demonstrating the characteristic of the relief valve by 1st Embodiment of this invention, Comprising: The relative position of the valve member with respect to a cylindrical inner wall, the overlapping area of a hole opening and a sliding outer wall, and an intermediate chamber The graph which shows the relationship with the minimum flow-path area between holes. It is sectional drawing of the hole part vicinity of the relief valve by 2nd Embodiment of this invention, Comprising: (A) is a figure which shows the state which the seat part is contact | abutting to the valve seat, (B) is a sheet | seat part from a valve seat. The figure which shows the state which has isolate | separated, (C) is a figure which shows the state which the sheet | seat part is spaced apart from a valve seat, and the valve member is contact | abutting to the movement control part. It is a figure for demonstrating the characteristic of the relief valve by 2nd Embodiment of this invention, Comprising: The relative position of the valve member with respect to a cylindrical inner wall, the overlapping area of a hole opening and a sliding outer wall, and an intermediate chamber The graph which shows the relationship with the minimum flow-path area between holes. It is sectional drawing of the hole part vicinity of the relief valve by 3rd Embodiment of this invention, Comprising: (A) is a figure which shows the state which has contact | abutted the valve seat, (B) is a sheet | seat part from a valve seat. The figure which shows the state which has isolate | separated, (C) is a figure which shows the state which the sheet | seat part is spaced apart from a valve seat, and the valve member is contact | abutting to the movement control part. It is a figure for demonstrating the characteristic of the relief valve by 3rd Embodiment of this invention, Comprising: The relative position of the valve member with respect to a cylindrical inner wall, the overlapping area of a hole opening and a sliding outer wall, and an intermediate chamber The graph which shows the relationship with the minimum flow-path area between holes. It is sectional drawing of the relief valve by 4th Embodiment of this invention, Comprising: (A) is a figure which shows the state which the seat part is contact | abutting to the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the hole part vicinity of the relief valve by 4th Embodiment of this invention, Comprising: (A) is a figure which shows the state which the seat part has contact | abutted to the valve seat, (B) is a sheet | seat part from a valve seat. The figure which shows the state which has isolate | separated, (C) is a figure which shows the state which the sheet | seat part is spaced apart from a valve seat, and the valve member is contact | abutting to the movement control part. It is a figure for demonstrating the characteristic of the relief valve by 4th Embodiment of this invention, Comprising: The relative position of the valve member with respect to a cylindrical inner wall, the overlapping area of a hole opening and a sliding outer wall, and an intermediate chamber The graph which shows the relationship with the minimum flow-path area between holes. It is sectional drawing of the relief valve by 5th Embodiment of this invention, Comprising: (A) is a figure which shows the state which the sheet | seat part is contact | abutting to the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the relief valve by the 1st reference form of this invention, Comprising: (A) is a figure which shows the state which the seat part is contact | abutting to the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the relief valve by the 2nd reference form of this invention, Comprising: (A) is a figure which shows the state which the sheet | seat part is contact | abutting to the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the relief valve by the 3rd reference form of this invention, Comprising: (A) is a figure which shows the state which has contact | abutted the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the relief valve by the 4th reference form of this invention, Comprising: (A) is a figure which shows the state which the sheet | seat part contact | abuts to the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the relief valve by the 5th reference form of this invention, Comprising: (A) is a figure which shows the state which the seat part is contact | abutting to the valve seat, (B) is separated from the valve seat. The figure which shows a state. It is sectional drawing of the relief valve by the 6th reference form of this invention, Comprising: (A) is a figure which shows the state which has contact | abutted the valve seat, (B) is separated from the valve seat. The figure which shows a state.

  Hereinafter, relief valves according to a plurality of embodiments and reference embodiments of the present invention will be described with reference to the drawings. In the plurality of embodiments and reference embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted. In the plurality of embodiments and the reference embodiment, substantially the same constituent parts have the same or similar operational effects.

(First embodiment)
A relief valve according to a first embodiment of the present invention is shown in FIG.
As shown in FIG. 2, the relief valve 1 is provided in the high pressure pump 10. The high-pressure pump 10 is provided in a vehicle (not shown). Here, the vehicle can run using, for example, an internal combustion engine that uses gasoline as fuel as a drive source.

  The fuel pump 3 pumps up the fuel stored in the fuel tank 2 and supplies it to the high-pressure pump 10 via the pipe 4. The high-pressure pump 10 pressurizes and discharges the fuel supplied from the fuel pump 3 and supplies the fuel rail 6 via the pipe 5. As a result, high-pressure fuel is stored in the fuel rail 6. The fuel in the fuel rail 6 is supplied to the internal combustion engine of the vehicle via a plurality of injectors 7 connected to the fuel rail 6.

The high-pressure pump 10 includes a housing 11, a suction valve 16, a discharge valve 17, a drive unit 18, a plunger 19, a spring 191, a relief valve 1, and the like.
The housing 11 has a pressurizing chamber 12, a suction passage 13, a discharge passage 14, a fuel chamber 15, and the like.

  The housing 11 is made of a metal such as stainless steel. As shown in FIG. 3, the pressurizing chamber 12, the suction passage 13, the discharge passage 14, and the fuel chamber 15 are formed by cutting the housing 11, for example. The fuel chamber 15 is formed so as to be connected to the suction passage 13. The suction passage 13 is formed so as to be connected to the pressurizing chamber 12. The pressurizing chamber 12 is formed so as to be connected to the discharge passage 14. Here, for convenience, the space in the discharge passage 14 is referred to as a first space 101. The space in the fuel chamber 15 is referred to as the second space 102. The second space 102 is a space isolated from the first space 101, that is, a space different from the first space 101.

  The pipe 4 connected to the fuel pump 3 is connected to an inlet portion formed in the housing 11 so as to connect to the fuel chamber 15. Thus, the fuel in the fuel tank 2 is supplied from the fuel pump 3 to the fuel chamber 15 (second space 102) via the pipe 4 and the inlet portion.

  As shown in FIG. 2, the suction valve 16 is provided between the suction passage 13 and the pressurizing chamber 12. The intake valve 16 includes a valve seat 161, a valve body 162, and an urging member 163. The valve seat 161 is formed on the inner wall of the suction passage 13 on the pressure chamber 12 side. The valve body 162 is provided so as to contact the valve seat 161 from the pressurizing chamber 12 side. The urging member 163 urges the valve body 162 toward the valve seat 161 side. When the valve body 162 is separated from the valve seat 161 or comes into contact with the valve seat 161, the fuel flow between the suction passage 13 and the pressurizing chamber 12 is permitted or restricted.

  The discharge valve 17 is provided between the pressurizing chamber 12 and the discharge passage 14. The discharge valve 17 includes a valve seat 171, a valve body 172, and an urging member 173. The valve seat 171 is formed on the inner wall of the pressurizing chamber 12 on the discharge passage 14 side. The valve body 172 is provided to be able to contact the valve seat 171 from the discharge passage 14 side. The urging member 173 urges the valve body 172 to the valve seat 171 side. When the valve body 172 moves away from the valve seat 171 or abuts against the valve seat 171, the fuel flow between the pressurizing chamber 12 and the discharge passage 14 is permitted or restricted. Here, the discharge valve 17 allows the flow of fuel from the pressurization chamber 12 side to the discharge passage 14 side, regulates the flow of fuel from the discharge passage 14 side to the pressurization chamber 12 side, and serves as a check valve. Function.

  The drive unit 18 is provided on the suction passage 13 side of the suction valve 16. The drive unit 18 can be driven so that the valve body 162 of the suction valve 16 moves to the valve seat 161 side or the pressurizing chamber 12 side when electric power is supplied. In the present embodiment, for example, when power is not supplied to the drive unit 18, the drive unit 18 urges the valve body 162 toward the pressurizing chamber 12 against the urging force of the urging member 163. The valve body 162 is separated from the valve seat 161, that is, in a state in which the valve is opened. When electric power is supplied to the drive unit 18, the drive unit 18 drives the valve body 162 so as to reduce the force that biases the valve body 162 toward the pressurizing chamber 12. Thereby, the valve body 162 moves to the valve seat 161 side by the urging force of the urging member 163 and contacts the valve seat 161, that is, closes the valve. Thus, the suction valve 16 of this embodiment functions as a so-called normally open type valve device in combination with the drive unit 18.

  The plunger 19 is formed in a rod shape from a metal such as stainless steel. The plunger 19 is provided so that one end side is inserted inside the cylinder part formed in the housing 11 so as to be connected to the pressurizing chamber 12. The plunger 19 has an outer wall slidable with the inner wall of the cylinder part, and is supported by the inner wall of the cylinder part so as to be reciprocally movable in the axial direction. When the plunger 19 reciprocates in the axial direction, the volume of the pressurizing chamber 12 changes.

  The high-pressure pump 10 is provided such that the other end of the plunger 19 comes into contact with a cam 9 provided on the camshaft 8 of the internal combustion engine of the vehicle. The high-pressure pump 10 includes a spring 191 that biases the plunger 19 toward the cam 9. With this configuration, when the internal combustion engine is operating, the camshaft 8 and the cam 9 rotate in synchronization with the crankshaft, and the plunger 19 reciprocates in the axial direction.

  When the plunger 19 moves to the cam 9 side with the intake valve 16 opened, the volume of the pressurizing chamber 12 increases, and the fuel in the intake passage 13 is sucked into the pressurizing chamber 12. Further, when the plunger 19 moves to the side opposite to the cam 9 with the intake valve 16 opened, the volume of the pressurizing chamber 12 decreases and the fuel in the pressurizing chamber 12 is returned to the intake passage 13. .

  On the other hand, when the plunger 19 moves to the side opposite to the cam 9 with the intake valve 16 closed, the volume of the pressurizing chamber 12 decreases, and the fuel in the pressurizing chamber 12 is compressed and pressurized. . When the pressure of the fuel in the pressurizing chamber 12 becomes equal to or higher than the opening pressure of the discharge valve 17, the discharge valve 17 is opened, and the fuel is discharged from the pressurizing chamber 12 to the discharge passage 14 (first space 101).

  The pipe 5 connected to the fuel rail 6 is connected to an outlet portion formed in the housing 11 so as to be connected to the discharge passage 14. As a result, the fuel pressurized in the pressurizing chamber 12 is supplied to the fuel rail 6 via the discharge passage 14, the outlet portion, and the pipe 5. As a result, high-pressure fuel is stored in the fuel rail 6.

Next, the configuration of the relief valve 1 will be described in detail with reference to FIG.
The relief valve 1 includes a body portion 20, a valve seat portion 40, a valve member 50, a biasing member 60, a spring seat portion 70, a movement restricting portion 74, a sealing portion 80, and the like.

  The body part 20 is formed in a substantially cylindrical shape with a metal such as stainless steel. In the present embodiment, the body portion 20 is formed integrally with the housing 11 of the high-pressure pump 10. That is, it can be said that the body portion 20 is a part of the housing 11.

  The body portion 20 includes a cylindrical inner wall 21, a first hole portion 25 as a “hole portion”, a hole portion opening 26, a second hole portion 27, and the like. The cylindrical inner wall 21 is an inner wall of the body portion 20 and is formed in a substantially cylindrical shape. Here, a space inside the cylindrical inner wall 21 is referred to as an inner space 103.

  The cylindrical inner wall 21 has a reference inner diameter portion 22, a first large diameter portion 23, a second large diameter portion 24, and the like. The reference inner diameter portion 22 is a portion formed in a cylindrical shape so as to have a predetermined inner diameter in the cylindrical inner wall 21. The first large diameter portion 23 is a portion of the cylindrical inner wall 21 that is formed in a cylindrical shape so as to have an inner diameter larger than the inner diameter of the reference inner diameter portion 22, and is formed on one end side of the reference inner diameter portion 22. The second large diameter portion 24 is a portion formed in a cylindrical shape so as to have an inner diameter larger than the inner diameter of the first large diameter portion 23 in the cylindrical inner wall 21, and is formed on the other end side of the reference inner diameter portion 22. ing.

  The first hole 25 is formed so as to connect the inner space 103 and the second space 102 (the space in the fuel chamber 15). As a result, a hole opening 26 that is an opening of the first hole 25 is formed in the reference inner diameter portion 22 of the cylindrical inner wall 21. In this embodiment, the 1st hole part 25 is formed so that an inner wall may become cylindrical shape. Therefore, the shape of the hole opening 26 is circular. The shape of the hole opening 26 is a perfect circle when viewed from the radial direction of the cylindrical inner wall 21.

  The second hole 27 is formed at a location different from the first hole 25 so as to connect the inner space 103 and the second space 102 (the space in the fuel chamber 15). Thereby, the opening of the second hole portion 27 is formed in the second large diameter portion 24 of the cylindrical inner wall 21.

  The valve seat part 40 is formed, for example with metals, such as stainless steel. In the present embodiment, the valve seat portion 40 is formed integrally with the housing 11 of the high-pressure pump 10. That is, it can be said that the valve seat portion 40 is a part of the housing 11 like the body portion 20.

  The valve seat portion 40 is provided so as to close one end of the cylindrical inner wall 21 of the body portion 20, that is, the first large diameter portion 23 side. The valve seat portion 40 is formed integrally with the body portion 20. Here, the side opposite to the reference inner diameter portion 22 of the second large diameter portion 24 of the cylindrical inner wall 21 is connected to the outer wall of the housing 11. That is, the other end of the cylindrical inner wall 21 is formed to open to the outer wall of the housing 11.

  The valve seat portion 40 has a valve hole 41, a valve seat 42, and the like. The valve hole 41 is formed to connect the inner space 103 and the first space 101 (the space in the discharge passage 14). The valve seat 42 is formed in an annular shape on the outer diameter side of the end portion on the inner space 103 side of the valve hole 41. In the present embodiment, the valve seat 42 is formed in a tapered shape so as to be separated from the axis of the valve hole 41 toward the inner space 103 side.

The valve member 50 is formed of a metal such as stainless steel, for example, and is provided inside the body portion 20. The valve member 50 includes a valve main body 51, a sliding outer wall 55, a seat portion 58, and the like.
The valve main body 51 has a cylindrical part 52, a bottom part 56, and a protruding part 57. The cylindrical part 52 has a large diameter part 53 and a small diameter part 54. The large diameter portion 53 is set so that the outer diameter is equal to the inner diameter of the reference inner diameter portion 22 of the cylindrical inner wall 21 or slightly smaller than the inner diameter of the reference inner diameter portion 22. As a result, the outer wall of the large diameter portion 53 can slide on the reference inner diameter portion 22. Here, the outer wall of the large-diameter portion 53 corresponds to the sliding outer wall 55.

The small diameter portion 54 is a portion having an outer diameter smaller than the outer diameter of the large diameter portion 53 in the cylindrical portion 52, and is formed on the valve seat portion 40 side of the large diameter portion 53.
The bottom portion 56 is formed integrally with the cylindrical portion 52 so as to close the end portion on the small diameter portion 54 side of the cylindrical portion 52. The protruding portion 57 is formed integrally with the bottom portion 56 so as to protrude in a columnar shape from the center of the bottom portion 56 toward the valve seat 42 side.
The valve main body 51 is provided so as to be capable of reciprocating in the axial direction within the body portion 20.

The seat portion 58 is formed integrally with the protruding portion 57 on the valve seat 42 side of the protruding portion 57. The seat portion 58 is formed in a tapered shape so that the outer wall of the end portion on the valve seat 42 side approaches the axis of the protruding portion 57 as it goes toward the valve seat 42 side. The seat portion 58 can abut the valve seat 42 on the outer wall of the end portion on the valve seat 42 side.
The valve member 50 changes its volume depending on the axial position of the valve main body 51 with respect to the cylindrical inner wall 21, and has an intermediate chamber 104 that can communicate with the valve hole 41 and the first hole portion 25, with the cylindrical inner wall 21 and the valve seat portion 40. Form between.

When the seat portion 58 is separated from the valve seat 42, the valve member 50 allows the valve hole 41 and the intermediate chamber 104 to communicate with each other and allows fuel to flow between the valve hole 41 and the intermediate chamber 104. Further, the valve member 50 shuts off the valve hole 41 and the intermediate chamber 104 when the seat portion 58 comes into contact with the valve seat 42, and restricts the flow of fuel between the valve hole 41 and the intermediate chamber 104.
The urging member 60 is, for example, a coil spring, and is opposite to the valve seat portion 40 of the bottom portion 56 so that one end side is located inside the cylindrical portion 52 of the valve member 50 and one end abuts against the bottom portion 56 of the valve member 50. On the side.

  The spring seat part 70 is formed, for example with metals, such as stainless steel, and is provided in the opposite side to the valve seat part 40 of the valve member 50. As shown in FIG. The spring seat portion 70 has a cylindrical portion 71, a bottom portion 72, and the like. The outer diameter of the cylindrical portion 71 is set to be equal to or slightly larger than the inner diameter of the reference inner diameter portion 22 of the cylindrical inner wall 21. The cylinder portion 71 is provided inside the body portion 20 so that the outer wall on one end side contacts the reference inner diameter portion 22. The cylinder portion 71 is fixed to the inside of the body portion 20 by, for example, welding or press fitting.

  The bottom portion 72 is formed integrally with the cylinder portion 71 so as to close the other end side of the cylinder portion 71. The bottom portion 72 has a hole 73 that connects one surface and the other surface at the center. The hole 73 connects the space inside the cylinder 71 and the space outside.

  In the present embodiment, the movement restricting portion 74 is formed at the end portion of the spring seat portion 70 opposite to the bottom portion 72 of the cylindrical portion 71. The movement restricting portion 74 can come into contact with an end portion of the valve member 50 on the side opposite to the bottom portion 56 of the cylindrical portion 52. Therefore, the movement restricting portion 74 can restrict the valve member 50 from moving in a direction away from the valve seat 42 by contacting the cylinder portion 52. That is, in this embodiment, the valve member 50 can move between the valve seat portion 40 and the movement restricting portion 74. The axially movable distance of the valve member 50 is a distance between the cylinder portion 52 and the movement restricting portion 74 when the seat portion 58 is in contact with the valve seat 42.

  The biasing member 60 is provided on the valve member 50 side of the bottom portion 72 so that the other end side is located inside the cylindrical portion 71 of the spring seat portion 70 and the other end abuts on the bottom portion 72 of the spring seat portion 70. . The distance between the bottom portion 56 of the valve member 50 and the bottom portion 72 of the spring seat portion 70 when the seat portion 58 of the valve member 50 is in contact with the valve seat 42 is set to be shorter than the free length of the biasing member 60. Yes. Therefore, the urging member 60 urges the valve member 50 toward the valve seat portion 40.

  The sealing portion 80 is formed of a metal such as stainless steel, for example, and is provided on the opposite side of the spring seat portion 70 from the valve member 50. The sealing part 80 has a main body 81 and a cylindrical part 82. The cylindrical portion 82 is formed integrally with the main body 81 so as to extend from the main body 81 in a cylindrical shape. A thread groove is formed on the outer wall of the cylindrical portion 82. In addition, a thread groove corresponding to the thread groove of the cylindrical portion 82 is formed in the second large diameter portion 24 of the body portion 20. The sealing portion 80 is provided on the body portion 20 so that the cylindrical portion 82 is screwed into the second large diameter portion 24.

Here, the sealing portion 80 seals the other end of the cylindrical inner wall 21, that is, the opening formed in the outer wall of the housing 11. In addition, the cylindrical portion 82 of the sealing portion 80 is located on the outer diameter side of the other end of the cylindrical portion 71 of the spring seat portion 70, and forms a cylindrical space between the outer wall of the cylindrical portion 71. Further, a space is formed between the bottom portion 72 of the spring seat portion 70 and the sealing portion 80. Thereby, the space inside the cylinder part 71 of the spring seat part 70 is a hole 73, a space between the bottom part 72 and the sealing part 80, a cylindrical space between the cylinder part 82 and the cylinder part 71, It communicates with the second space 102 (the space in the fuel chamber 15) via the second hole portion 27. Thereby, the reciprocating movement of the valve member 50 in the body portion 20 in the axial direction can be made smooth.
The valve opening pressure of the relief valve 1 (valve member 50) is determined by the biasing force of the biasing member 60 and the fuel pressure in the space on the spring seat portion 70 side of the valve member 50 in the inner space 103 (the fuel pressure in the fuel chamber 15). Pressure).

  Next, the relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp that is the area where the hole opening 26 and the sliding outer wall 55 overlap, and the space between the intermediate chamber 104 and the first hole 25. The relationship with the minimum channel area Sf, which is the minimum channel area, will be described with reference to FIGS.

  As shown in FIG. 1B, in this embodiment, the area of the cross section orthogonal to the axis of the cylindrical gap formed between the reference inner diameter portion 22 of the body portion 20 and the small diameter portion 54 of the valve member 50. The gap area Ss is larger than the opening area So which is the area of the hole opening 26. That is, the body part 20, the valve member 50, and the hole opening 26 are formed so as to satisfy the relationship Ss> So.

  FIGS. 4A to 4C show the vicinity of the first hole 25 in the sectional view of the relief valve 1 in order to explain the positional relationship between the sliding outer wall 55 and the hole opening 26. Here, FIG. 4A corresponds to a cross section taken along line IVA-IVA of FIG.

  As shown in FIG. 4A, in the state where the seat portion 58 of the valve member 50 is in contact with the valve seat 42, the hole opening 26 and the sliding outer wall 55 are completely overlapped. Therefore, the overlapping area Sp, which is the area where the hole opening 26 and the sliding outer wall 55 overlap, is the same as the opening area So (area of the hole opening 26). Here, the minimum flow path area Sf, which is the minimum flow path area between the intermediate chamber 104 and the first hole portion 25, is zero.

  As shown in FIG. 4B, when the seat portion 58 of the valve member 50 is separated from the valve seat 42 and the valve member 50 further moves toward the spring seat portion 70, the overlapping area Sp becomes smaller than the opening area So. . Here, the minimum flow path area Sf is equal to the area obtained by subtracting the overlapping area Sp from the opening area So.

As shown in FIG. 4C, when the valve member 50 further moves toward the spring seat portion 70 and the cylindrical portion 52 abuts against the movement restricting portion 74, the overlapping area Sp is zero. Here, the minimum flow path area Sf is the same as the opening area So.
The relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp of the hole opening 26 and the sliding outer wall 55, and the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25. The relationship is shown in FIG.

  In FIG. 5, a position PA indicates a relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Moreover, the position PB has shown the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. 4 (B). Further, the position PC indicates the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Further, the overlapping area Sp is indicated by a one-dot chain line, and the minimum flow path area Sf is indicated by a solid line.

  As shown in FIG. 5, when the position of the valve member 50 is the position PA, the minimum flow path area Sf is zero. When the position of the valve member 50 is the position PC, the minimum flow path area Sf is the same as the opening area So.

  Further, as shown in FIG. 5, in this embodiment, the valve member 50 is at least within the axially movable range “at the hole opening 26 as the valve member 50 moves away from the valve seat 40. The overlapping area Sp, which is the area where the sliding outer wall 55 and the sliding outer wall 55 overlap, is gradually (continuously) reduced, and the minimum flow area Sf, which is the minimum flow area between the intermediate chamber 104 and the first hole 25. Includes a “specific range in which the value gradually increases (continuously)”. In other words, the valve member 50 has at least “overlap of the hole opening 26 and the sliding outer wall 55 as the valve member 50 moves away from the valve seat 40 within the axially movable range. A specific range in which the area Sp decreases gradually and the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25 gradually increases ”is included.

  In the present embodiment, the pressure of the fuel in the first space 101 becomes equal to or higher than the valve opening pressure of the valve member 50, and the seat portion 58 opens away from the valve seat 42, and the intermediate chamber 104 communicates with the first space 101. When the fuel pressure increases, the valve member 50 moves away from the valve seat 40. In the “specific range” described above, the minimum flow passage area Sf between the intermediate chamber 104 and the first hole portion 25 increases as the valve member 50 moves away from the valve seat portion 40, so that the fuel pressure in the intermediate chamber 104 is increased. The larger the is, the larger the flow rate of the fuel flowing from the intermediate chamber 104 to the first hole portion 25 is.

  In the present embodiment, when the valve member 50 moves in a direction approaching the valve seat portion 40, the overlap area Sp between the hole opening 26 and the sliding outer wall 55 gradually increases in the “specific range”. The minimum flow path area Sf between the intermediate chamber 104 and the first hole 25 is gradually reduced. Therefore, when the fuel flows from the intermediate chamber 104 to the first hole 25 to reduce the pressure of the fuel in the intermediate chamber 104 and the valve member 50 moves to the valve seat portion 40 side, the first hole extends from the intermediate chamber 104. The fuel flow to the section 25 is gradually reduced.

  Further, as described above, in the present embodiment, when the seat portion 58 is in contact with the valve seat 42 (position PA), the overlapping area Sp between the hole opening 26 and the sliding outer wall 55 is equal to that of the hole opening 26. As with the opening area So, the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25 is 0, that is, the intermediate chamber 104 and the first hole 25 are not in communication. Further, while the valve member 50 moves from the position PA to the position PO in FIG. 5, the intermediate chamber 104 and the first hole portion 25 are not in communication. That is, in the present embodiment, the valve member 50 includes “a non-communication range in which the intermediate chamber 104 and the first hole 25 are not in communication” in the axially movable range (see FIG. 5). ).

Next, the operation of the high-pressure pump 10 of this embodiment will be described with reference to FIG.
"Inhalation process"
When the supply of power to the drive unit 18 is stopped, the valve body 162 of the suction valve 16 is biased toward the pressurizing chamber 12 by the drive unit 18. Therefore, the valve body 162 is separated from the valve seat 161, that is, the intake valve 16 is opened. In this state, when the plunger 19 moves to the cam 9 side, the volume of the pressurizing chamber 12 increases, and the fuel in the suction passage 13 is sucked into the pressurizing chamber 12.

“Weighing process”
When the plunger 19 moves to the side opposite to the cam 9 with the intake valve 16 opened, the volume of the pressurizing chamber 12 decreases and the fuel in the pressurizing chamber 12 is returned to the intake passage 13. If electric power is supplied to the drive unit 18 during the metering process, the intake valve 16 is closed. When the plunger 19 moves to the side opposite to the cam 9, the amount of fuel returned from the pressurizing chamber 12 to the suction passage 13 by closing the suction valve 16 and shutting off the pressurization chamber 12 and the suction passage 13. Is adjusted. As a result, the amount of fuel pressurized in the pressurizing chamber 12 is determined. When the intake valve 16 is closed, the metering process for returning the fuel from the pressurizing chamber 12 to the intake passage 13 is completed.

"Pressurization process"
When the plunger 19 further moves to the side opposite to the cam 9 with the intake valve 16 closed, the volume of the pressurizing chamber 12 decreases, and the fuel in the pressurizing chamber 12 is compressed and pressurized. When the pressure of the fuel in the pressurizing chamber 12 becomes equal to or higher than the opening pressure of the discharge valve 17, the discharge valve 17 is opened, and the fuel is discharged from the pressurizing chamber 12 to the discharge passage 14 (first space 101).

  When the supply of electric power to the drive unit 18 is stopped and the plunger 19 moves to the cam 9 side, the intake valve 16 opens again. As a result, the pressurizing process for pressurizing the fuel is completed, and the suction process in which the fuel is sucked into the pressurizing chamber 12 from the suction passage 13 is resumed.

  By repeating the above “suction process”, “metering process”, and “pressurization process”, the high-pressure pump 10 pressurizes and discharges the fuel in the fuel tank 2 and supplies it to the fuel rail 6. The amount of fuel supplied from the high-pressure pump 10 to the fuel rail 6 is adjusted by controlling the supply timing of power to the drive unit 18 and the like.

  For example, when the supply of electric power to the drive unit 18 is stopped for a predetermined period, the intake valve 16 is kept open, so that fuel is not pressurized in the pressurizing chamber 12, and the fuel is high pressure. The fuel is not supplied from the pump 10 to the fuel rail 6. Further, even when the suction valve 16 is kept open for some reason such as sticking of the valve body 162, the fuel is not pressurized in the pressurizing chamber 12, and the fuel is fed from the high-pressure pump 10 to the fuel rail 6. Not supplied.

  On the other hand, for example, when the supply of electric power to the drive unit 18 continues for a predetermined period, the suction valve 16 is closed in the pressurizing step, so that the fuel is pressurized in the pressurizing chamber 12 and the fuel is supplied from the high-pressure pump 10. The pressure of the fuel in the discharge passage 14, the pipe 5, and the fuel rail 6 is increased by being supplied to the rail 6. In addition, even when the suction valve 16 is kept closed due to some cause such as sticking of the valve body 162, the fuel is pressurized in the pressurizing chamber 12 and supplied from the high-pressure pump 10 to the fuel rail 6, The pressure of the fuel in the discharge passage 14, the pipe 5, and the fuel rail 6 increases.

Next, the operation of the relief valve 1 of the present embodiment will be described with reference to FIG.
When the pressure of the fuel in the discharge passage 14 (first space 101) becomes equal to or higher than the valve opening pressure of the relief valve 1 (valve member 50), the seat portion 58 moves away from the valve seat 42 and opens into the first space 101. The pressure of the fuel in the communicating intermediate chamber 104 increases. Thereby, the valve member 50 moves in a direction away from the valve seat portion 40.

  When the valve member 50 further moves in the direction away from the valve seat 40, the intermediate chamber 104 and the first hole 25 communicate with each other via the hole opening 26. As a result, fuel flows from the intermediate chamber 104 to the first hole portion 25. The fuel that has flowed into the first hole portion 25 flows toward the fuel chamber 15.

  When the fuel pressure in the intermediate chamber 104 further increases and the valve member 50 moves further in the direction away from the valve seat 40, the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25 increases, The fuel easily flows from the chamber 104 to the first hole portion 25. Thereby, the pressure of the fuel in the intermediate chamber 104 and the discharge passage 14 (first space 101) communicating with the intermediate chamber 104 is quickly reduced.

When the pressure of the fuel in the intermediate chamber 104 decreases, the valve member 50 moves in a direction approaching the valve seat portion 40. When the valve member 50 moves in a direction approaching the valve seat portion 40, the minimum flow area Sf between the intermediate chamber 104 and the first hole portion 25 gradually decreases, and the fuel flows from the intermediate chamber 104 to the first hole portion 25. Is gradually squeezed. For this reason, the fuel in the intermediate chamber 104 is suppressed from rapidly decreasing in pressure, and the pressure is maintained at a certain value or more. At this time, the rapid movement of the valve member 50 toward the valve seat 40 is suppressed. Thereby, the position of the valve member 50 is maintained such that the minimum flow path area Sf is larger than 0, and the valve opening state separated from the valve seat 42 is maintained.
The pressure of the fuel in the discharge passage 14 (first space 101) is further reduced, the minimum flow path area Sf becomes substantially zero, and the fuel chamber 15 (second space 102) passes from the discharge passage 14 via the intermediate chamber 104. When the fuel flowing to the side becomes substantially zero, the seat portion 58 comes into contact with the valve seat 42 and the relief valve 1 is closed.

  In the present embodiment, since the minimum flow area Sf between the intermediate chamber 104 and the first hole portion 25 increases as the valve member 50 moves away from the valve seat portion 40 in the “specific range”, the inside of the intermediate chamber 104 As the fuel pressure increases, the flow rate of fuel flowing from the intermediate chamber 104 to the first hole 25 increases. Thereby, the fuel pressure in the first space 101 (the space in the discharge passage 14) communicating with the intermediate chamber 104 can be quickly reduced.

  Further, in the present embodiment, when the valve member 50 moves in the direction approaching the valve seat portion 40, in the “specific range”, the overlapping area Sp between the hole opening 26 and the sliding outer wall 55 gradually increases, and the middle The minimum flow path area Sf between the chamber 104 and the first hole 25 is gradually reduced. Therefore, when the fuel flows from the intermediate chamber 104 to the first hole 25 to reduce the pressure of the fuel in the intermediate chamber 104 and the valve member 50 moves to the valve seat portion 40 side, the first hole extends from the intermediate chamber 104. The fuel flow to the section 25 is gradually reduced. Thereby, “the fuel flow from the intermediate chamber 104 to the first hole 25 is suddenly throttled and the fuel pressure in the intermediate chamber 104 rapidly increases again” is suppressed. Therefore, when the pressure of the fuel in the first space 101 is reduced, pressure pulsation occurs in the fuel in the intermediate chamber 104 and the fuel in the first space 101 (space in the discharge passage 14) communicating with the intermediate chamber 104. It can be suppressed from occurring.

  As described above, (1) in the relief valve 1 of the present embodiment, the valve member 50 is at least “in the axially movable range,“ as the valve member 50 moves in a direction away from the valve seat 40, The overlapping area Sp, which is the area where the hole opening 26 and the sliding outer wall 55 overlap, gradually decreases, and the minimum flow area Sf, which is the minimum flow area between the intermediate chamber 104 and the first hole 25, is reduced. It includes a “specific range that gradually increases”.

  In the present embodiment, the pressure of the fuel in the first space 101 becomes equal to or higher than the valve opening pressure of the valve member 50, and the seat portion 58 opens away from the valve seat 42, and the intermediate chamber 104 communicates with the first space 101. When the fuel pressure increases, the valve member 50 moves away from the valve seat 40. In the “specific range” described above, the minimum flow passage area Sf between the intermediate chamber 104 and the first hole portion 25 increases as the valve member 50 moves away from the valve seat portion 40, so that the fuel pressure in the intermediate chamber 104 is increased. The larger the is, the larger the flow rate of the fuel flowing from the intermediate chamber 104 to the first hole portion 25 is. As a result, the fuel pressure in the first space 101 communicating with the intermediate chamber 104 can be quickly reduced.

  In the present embodiment, when the valve member 50 moves in a direction approaching the valve seat portion 40, the overlap area Sp between the hole opening 26 and the sliding outer wall 55 gradually increases in the “specific range”. The minimum flow path area Sf between the intermediate chamber 104 and the first hole 25 is gradually reduced. Therefore, when the fuel flows from the intermediate chamber 104 to the first hole 25 to reduce the pressure of the fuel in the intermediate chamber 104 and the valve member 50 moves to the valve seat portion 40 side, the first hole extends from the intermediate chamber 104. The fuel flow to the section 25 is gradually reduced. Thereby, “the fuel flow from the intermediate chamber 104 to the first hole 25 is suddenly throttled and the fuel pressure in the intermediate chamber 104 rapidly increases again” is suppressed. Therefore, when reducing the pressure of the fuel in the first space 101, it is possible to suppress the occurrence of pressure pulsation in the fuel in the intermediate chamber 104 and the fuel in the first space 101 communicating with the intermediate chamber 104. it can.

  (2) In the relief valve 1 of the present embodiment, when the seat portion 58 is in contact with the valve seat 42, the intermediate chamber 104 and the first hole portion 25 are not in communication. Further, the valve member 50 includes “a non-communication range in which the intermediate chamber 104 and the first hole portion 25 are not in communication” in the axially movable range. Therefore, in the non-communication range, the valve member 50 moves quickly in the direction away from the valve seat portion 40 as the fuel pressure in the intermediate chamber 104 increases. Further, it is possible to easily maintain the valve opening state of the valve member 50 that is once opened (in a specific range) (to make it difficult to close the valve).

  (3) The relief valve 1 of the present embodiment further includes a movement restricting portion 74 that can restrict the valve member 50 from moving in a direction away from the valve seat portion 40. Thereby, it is possible to suppress the valve member 50 from being too far from the valve seat portion 40 and damage (buckling) of the biasing member 60.

  In this embodiment, the maximum value of the minimum flow area Sf between the intermediate chamber 104 and the first hole 25 is equal to the opening area So of the hole opening 26, but the position of the movement restricting portion 74 is set as appropriate. Thus, the maximum value of the minimum flow path area Sf can be set to an arbitrary value equal to or smaller than the opening area So.

  (5) In the relief valve 1 of the present embodiment, the hole opening 26 is formed in a circular shape. Therefore, the relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp of the hole opening 26 and the sliding outer wall 55, and the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25. Is as shown in FIG.

  (6) The high-pressure pump 10 of the present embodiment is pressurized in the pressurizing chamber 12 that sucks and pressurizes the fuel, the suction passage 13 through which the fuel sucked into the pressurizing chamber 12 flows, and the pressurizing chamber 12. A housing 11 having a discharge passage 14 through which discharged fuel flows and the relief valve 1 are provided. The first space 101 is a space in the discharge passage 14. Therefore, when the pressure of the fuel in the discharge passage 14 (first space 101) communicating with the intermediate chamber 104 becomes high, the pressure can be quickly reduced. Further, when the pressure of the fuel in the discharge passage 14 (first space 101) is reduced, it is possible to suppress the occurrence of pressure pulsation in the fuel in the discharge passage 14 (first space 101). Thereby, damage to the piping 5 that connects the discharge passage 14 of the high-pressure pump 10 and the fuel rail 6 can be suppressed.

  (7) In the present embodiment, the second space 102 is a space in the fuel chamber 15 that communicates with the suction passage 13. That is, the relief valve 1 is provided such that the valve hole 41 communicates with the discharge passage 14 and the first hole 25 communicates with the fuel chamber 15. The relief valve 1 returns the fuel in the discharge passage 14 to the low pressure fuel chamber 15 side when the pressure of the fuel in the discharge passage 14 exceeds the opening pressure of the relief valve 1, and the pressure of the fuel in the discharge passage 14. Reduce.

  In addition, the high-pressure pump 10 of the present embodiment is provided between the pressurizing chamber 12 and the discharge passage 14, and a discharge valve 17 that can allow or regulate the flow of fuel between the pressurization chamber 12 and the discharge passage 14. It has. The high-pressure pump 10 includes a suction valve 16 that is provided between the pressurizing chamber 12 and the suction passage 13 and that allows or restricts the flow of fuel between the pressurization chamber 12 and the suction passage 13. . Furthermore, the high-pressure pump 10 includes a drive unit 18 that can change the open state of the intake valve 16.

  In this embodiment, the relief valve 1 is provided so that the back pressure side space (the space on the spring seat portion 70 side of the valve member 50) is connected to the low pressure fuel chamber 15 via the second hole portion 27. It has been. Therefore, the degree of freedom in setting the valve opening pressure of the relief valve 1 (valve member 50) can be increased. In the present embodiment, when the valve member 50 is closed, the hole opening 26 is closed by the sliding outer wall 55, so that the fuel pressure in the first hole 25 causes the valve member 50 to open. The influence on the pressure can be suppressed.

  Moreover, since the relief valve of the above-mentioned patent document 1 is provided so that the space on the back pressure side (the space on the biasing member side of the valve body and the movable holder) is connected to the pressurizing chamber of the high pressure pump, There is a possibility that the dead volume of the pressurizing chamber increases and it becomes difficult to sufficiently pressurize the fuel by the high pressure pump. On the other hand, in the high-pressure pump 10 of the present embodiment, the relief valve 1 is provided such that a space on the back pressure side (a space on the spring seat portion 70 side of the valve member 50) is connected to the fuel chamber 15. Therefore, an increase in the dead volume of the pressurizing chamber 12 is suppressed, and the fuel can be sufficiently pressurized by the high-pressure pump 10.

  Moreover, in the relief valve of patent document 1, since the valve body which contact | abuts a valve seat and the movable holder urged | biased by the urging | biasing member are formed in the different body, the position of a valve body and a movable holder shifts | deviates. This may cause a malfunction of the relief valve. On the other hand, in the relief valve 1 of the present embodiment, the seat portion 58 that contacts the valve seat 42 and the valve body 51 that is biased by the biasing member 60 are integrally formed. Therefore, the positions of the seat portion 58 and the valve main body 51 are not shifted.

  Further, in the relief valve of Patent Document 1, when the differential pressure between the fuel in the pressurizing chamber and the fuel in the discharge passage increases, the movable holder may come out of the guide hole. When the movable holder comes out of the guide hole, it may be difficult for the movable holder to enter the guide hole again. In this case, the valve body cannot be pressed against the valve seat, and the relief valve may not be closed. On the other hand, in the relief valve 1 of the present embodiment, the valve member 50 is configured such that the sliding outer wall 55 can always slide on the cylindrical inner wall 21 regardless of the axial position in the body portion 20. The movement of the member 50 in the axial direction is stabilized. Further, in the relief valve 1 of the present embodiment, unlike the relief valve of Patent Document 1, the valve cannot be closed.

Moreover, in the relief valve of patent document 1, the outer peripheral surface of the urging member that urges the movable holder faces the flow path connecting the discharge passage and the pressurizing chamber. Therefore, when reducing the pressure of the fuel in the discharge passage, the fuel flowing from the discharge passage side to the pressurizing chamber side contacts the outer peripheral surface of the end portion of the biasing member, particularly the movable holder side, and the position of the movable holder is May become unstable. On the other hand, in the relief valve 1 of the present embodiment, the outer peripheral surface of the end portion on the valve member 50 side of the urging member 60 is covered with the cylindrical portion 52. Further, the outer peripheral surface of the urging member 60 does not face the flow path connecting the discharge passage 14 and the fuel chamber 15. Therefore, in this embodiment, when the pressure of the fuel in the discharge passage 14 is reduced, the fuel flowing from the discharge passage 14 side to the fuel chamber 15 side does not contact the outer peripheral surface of the urging member 60. Thereby, the position of the valve member 50 can be stabilized.
In the present embodiment, the body portion 20 of the relief valve 1 is formed integrally with the housing 11 of the high-pressure pump 10. Thereby, the number of members can be reduced.

(Second Embodiment)
A relief valve according to a second embodiment of the present invention will be described with reference to FIGS. In 2nd Embodiment, the shape of the hole opening 26 formed in the cylindrical inner wall 21 of the body part 20 differs from 1st Embodiment.
As shown in FIG. 6A, in the present embodiment, the hole opening 26 is formed in a rectangular shape. Here, the hole opening 26 is formed in a rectangular shape so that the longitudinal direction is parallel to the axial direction of the sliding outer wall 55.

  As shown in FIG. 6A, in the state where the seat portion 58 of the valve member 50 is in contact with the valve seat 42, the hole opening 26 and the sliding outer wall 55 completely overlap. Therefore, the overlapping area Sp, which is the area where the hole opening 26 and the sliding outer wall 55 overlap, is the same as the opening area So (area of the hole opening 26). Here, the minimum flow path area Sf, which is the minimum flow path area between the intermediate chamber 104 and the first hole portion 25, is zero.

  As shown in FIG. 6B, when the seat portion 58 of the valve member 50 is separated from the valve seat 42 and the valve member 50 further moves toward the spring seat portion 70, the overlapping area Sp becomes smaller than the opening area So. . Here, the minimum flow path area Sf is equal to the area obtained by subtracting the overlapping area Sp from the opening area So.

As shown in FIG. 6C, when the valve member 50 further moves toward the spring seat portion 70 and the cylindrical portion 52 abuts against the movement restricting portion 74, the overlapping area Sp is zero. Here, the minimum flow path area Sf is the same as the opening area So.
The relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp of the hole opening 26 and the sliding outer wall 55, and the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25. The relationship is shown in FIG.

In FIG. 7, a position PA indicates a relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Moreover, the position PB has shown the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. 6 (B). Further, the position PC indicates the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Further, the overlapping area Sp is indicated by a one-dot chain line, and the minimum flow path area Sf is indicated by a solid line.
As shown in FIG. 7, when the position of the valve member 50 is the position PA, the minimum flow path area Sf is zero. When the position of the valve member 50 is the position PC, the minimum flow path area Sf is the same as the opening area So.

  As shown in FIG. 7, in this embodiment, as in the first embodiment, the valve member 50 is at least “moved in a direction in which the valve member 50 moves away from the valve seat portion 40 in the axially movable range. Accordingly, the overlap area Sp, which is an area where the hole opening 26 and the sliding outer wall 55 overlap, is gradually reduced, and the minimum flow path which is the minimum flow area between the intermediate chamber 104 and the first hole 25 is obtained. It includes a “specific range in which the area Sf gradually increases”.

  In FIG. 7, the minimum flow path area Sf between the intermediate chamber 104 and the 1st hole part 25 of 1st Embodiment is shown with a broken line. Within a specific range, in the first embodiment, the minimum flow passage area Sf changes (increases) in a curved shape (sinusoidal) with a change in the position of the valve member 50, and as shown in FIG. As the position of the member 50 changes, the minimum flow path area Sf changes (increases) linearly (linear function). In the second embodiment, the change rate (inclination) of the minimum flow path area Sf accompanying the change in the position of the valve member 50 in the specific range, particularly on the position PA side, is larger than that in the first embodiment. Therefore, in the second embodiment, as compared with the first embodiment, the fuel in the intermediate chamber 104 can flow quickly into the first hole portion 25 in the specific range, particularly on the position PA side.

(Third embodiment)
A relief valve according to a third embodiment of the present invention will be described with reference to FIGS. In 3rd Embodiment, the shape of the hole opening 26 formed in the cylindrical inner wall 21 of the body part 20 differs from 1st Embodiment.
As shown in FIG. 8A, in the present embodiment, the hole opening 26 is formed in a triangular shape. Here, the hole opening 26 is formed so that one of the apexes of the triangle faces the valve seat 40 side.

  As shown in FIG. 8A, in the state where the seat portion 58 of the valve member 50 is in contact with the valve seat 42, the hole opening 26 and the sliding outer wall 55 completely overlap. Therefore, the overlapping area Sp, which is the area where the hole opening 26 and the sliding outer wall 55 overlap, is the same as the opening area So (area of the hole opening 26). Here, the minimum flow path area Sf, which is the minimum flow path area between the intermediate chamber 104 and the first hole portion 25, is zero.

  As shown in FIG. 8B, when the seat portion 58 of the valve member 50 moves away from the valve seat 42 and the valve member 50 further moves toward the spring seat portion 70, the overlapping area Sp becomes smaller than the opening area So. . Here, the minimum flow path area Sf is equal to the area obtained by subtracting the overlapping area Sp from the opening area So.

As shown in FIG. 8C, when the valve member 50 further moves toward the spring seat portion 70 and the cylindrical portion 52 abuts against the movement restricting portion 74, the overlapping area Sp is zero. Here, the minimum flow path area Sf is the same as the opening area So.
The relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp of the hole opening 26 and the sliding outer wall 55, and the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25. The relationship is shown in FIG.

In FIG. 9, a position PA indicates a relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Moreover, the position PB has shown the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. 8 (B). Further, the position PC indicates the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Further, the overlapping area Sp is indicated by a one-dot chain line, and the minimum flow path area Sf is indicated by a solid line.
As shown in FIG. 9, when the position of the valve member 50 is the position PA, the minimum flow path area Sf is zero. When the position of the valve member 50 is the position PC, the minimum flow path area Sf is the same as the opening area So.

  As shown in FIG. 9, in this embodiment, as in the first embodiment, the valve member 50 is at least “moved in a direction in which the valve member 50 moves away from the valve seat portion 40 in the axially movable range. Accordingly, the overlap area Sp, which is an area where the hole opening 26 and the sliding outer wall 55 overlap, is gradually reduced, and the minimum flow path which is the minimum flow area between the intermediate chamber 104 and the first hole 25 is obtained. It includes a “specific range in which the area Sf gradually increases”.

  In FIG. 9, the minimum flow path area Sf between the intermediate chamber 104 and the 1st hole part 25 of 1st Embodiment is shown with a broken line. As shown in FIG. 9, within the specific range, the minimum flow path area Sf changes (increases) in a curved shape (sinusoidal) with the change in the position of the valve member 50 in the first embodiment, and the valve in the third embodiment. As the position of the member 50 changes, the minimum flow path area Sf changes (increases) in a curved shape (second-order function). In the third embodiment, the change rate (inclination) of the minimum flow path area Sf accompanying the change in the position of the valve member 50 in the specific range, particularly on the position PA side, is smaller than that in the first embodiment. Therefore, in 3rd Embodiment, compared with 1st Embodiment, the valve-opening state of the valve member 50 once opened can be made easier to maintain (it is difficult to close).

(Fourth embodiment)
A relief valve according to a fourth embodiment of the present invention is shown in FIG. In 4th Embodiment, the position of the hole opening 26 (1st hole 25) formed in the cylindrical inner wall 21 of the body part 20 differs from 1st Embodiment.

  As shown in FIG. 10, in the fourth embodiment, the first hole portion 25 and the hole portion opening 26 are formed at positions close to the valve seat portion 40 as compared with the first embodiment. Therefore, in the fourth embodiment, when the seat portion 58 is in contact with the valve seat 42, the intermediate chamber 104 and the first hole portion 25 communicate with each other via the hole portion opening 26.

  Next, in the fourth embodiment, the relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp that is the area where the hole opening 26 and the sliding outer wall 55 overlap, and the intermediate chamber 104 and the first hole The relationship with the minimum flow path area Sf which is the minimum flow path area between the unit 25 will be described with reference to FIGS.

  As shown in FIG. 11A, the hole opening 26 and the sliding outer wall 55 partially overlap with each other in a state where the seat portion 58 of the valve member 50 is in contact with the valve seat 42. Here, the overlapping area Sp, which is the area where the hole opening 26 and the sliding outer wall 55 overlap, is about half of the opening area So (the area of the hole opening 26). Here, the minimum flow path area Sf is equal to the area obtained by subtracting the overlapping area Sp from the opening area So.

As shown in FIG. 11B, when the seat portion 58 of the valve member 50 is separated from the valve seat 42 and the valve member 50 further moves toward the spring seat portion 70, the overlapping area Sp becomes zero. Here, the minimum flow path area Sf is the same as the opening area So.
As shown in FIG. 11C, when the valve member 50 further moves toward the spring seat portion 70 and the tube portion 52 comes into contact with the movement restricting portion 74, the overlapping area Sp is zero.
The relative position of the valve member 50 with respect to the cylindrical inner wall 21, the overlapping area Sp of the hole opening 26 and the sliding outer wall 55, and the minimum flow path area Sf between the intermediate chamber 104 and the first hole 25. The relationship is shown in FIG.

  In FIG. 12, a position PA indicates a relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Moreover, the position PB has shown the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. 11 (B). Further, the position PC indicates the relative position of the valve member 50 with respect to the cylindrical inner wall 21 at the time of FIG. Further, the overlapping area Sp is indicated by a one-dot chain line, and the minimum flow path area Sf is indicated by a solid line.

  As shown in FIG. 12, when the position of the valve member 50 is the position PA, the minimum flow path area Sf is about half of the opening area So (the area of the hole opening 26). Further, when the position of the valve member 50 is the positions PB and PC, the minimum flow path area Sf is the same as the opening area So.

Further, as shown in FIG. 12, in this embodiment, the valve member 50 is at least in the axially movable range “at the hole opening 26 as the valve member 50 moves away from the valve seat portion 40. The overlapping area Sp, which is the area where the sliding outer wall 55 and the sliding outer wall 55 overlap, gradually decreases, and the minimum channel area Sf, which is the minimum channel area between the intermediate chamber 104 and the first hole 25, gradually increases. Range ".
Further, in the present embodiment, unlike the first embodiment, the valve member 50 has a “non-communication range in which the intermediate chamber 104 and the first hole portion 25 are non-communication within the axially movable range. “Range” is not included (see FIG. 12).

(Fifth embodiment)
A relief valve according to a fifth embodiment of the present invention is shown in FIG. In 5th Embodiment, the shape of the cylinder part 52 of the valve member 50 differs from 1st Embodiment.

  In the fifth embodiment, the valve member 50 has a recess 59. The recess 59 is formed so as to be recessed radially inward from the sliding outer wall 55 at a position corresponding to the hole opening 26 in a state where the seat 58 is in contact with the valve seat 42 (see FIG. 13A). . For this reason, the outer edge portion of the hole opening 26 slides on the sliding outer wall 55 until the valve member 50 moves a predetermined distance in a direction away from the valve seat portion 40 after the seat portion 58 is in contact with the valve seat 42. Does not move. Therefore, wear of the outer edge portion of the hole opening 26 can be suppressed. Moreover, the malfunction of the valve member 50 (valve opening failure) by the sliding outer wall 55 of the valve member 50 being caught by the outer edge part or inner edge part of the hole opening 26 can be suppressed.

(First reference form)
FIG. 14 shows a relief valve according to the first reference embodiment of the present invention.
In the first reference form, the body part 20 does not have the first hole part 25 and the hole part opening 26 shown in the first embodiment (FIG. 1).

  In the first reference form, the body portion 20 has a third large diameter portion 211. The third large diameter portion 211 is formed in the middle of the reference inner diameter portion 22 in the axial direction. The third large diameter portion 211 has an inner diameter that is larger than the inner diameters of the reference inner diameter portion 22 and the first large diameter portion 23 and smaller than the inner diameter of the second large diameter portion 24.

The valve member 50 has a notch 521 and a hole 522. The cutout portion 521 is formed by cutting out the outer wall on the small diameter portion 54 side of the large diameter portion 53 of the cylindrical portion 52 in a planar shape. The notch 521 is formed so as to be a plane parallel to the axis of the cylindrical portion 52. That is, a part of the outer wall of the large-diameter portion 53 in the circumferential direction of the cylindrical portion 52 is cut out in a planar shape. Therefore, the cross-sectional shape of the surface perpendicular to the axis of the outer wall of the large-diameter portion 53 including the notch portion 521 is substantially D-shaped.
The hole 522 is formed so as to connect the outer wall and the inner wall of the large-diameter portion 53 of the cylindrical portion 52.

  14B, when the relief valve is opened, the pressure of the fuel in the intermediate chamber 104 increases, and the valve member 50 moves away from the valve seat 40, the intermediate chamber 104 and the space inside the cylindrical portion 52 are in a state of communicating with each other through the hole portion 522 between the notch portion 521 and the cylindrical inner wall 21 (third large diameter portion 211). As a result, the fuel in the first space 101 (discharge passage 14) flows between the valve hole 41, the intermediate chamber 104, the notch portion 521 and the cylindrical inner wall 21 (third large diameter portion 211), the hole portion 522, The inside of the spring seat part 70, between the spring seat part 70 and the sealing part 80, can be circulated to the second space 102 (fuel chamber 15) side via the second hole part 27. As a result, the pressure of the fuel in the discharge passage 14 can be reduced.

(Second reference form)
A relief valve according to the second embodiment of the present invention is shown in FIG.
In the second reference form, the body part 20 does not have the first hole part 25 and the hole part opening 26 shown in the first embodiment (FIG. 1).

  In the second reference embodiment, the relief valve includes a rod portion 61. The rod portion 61 is formed of a metal such as stainless steel in a rod shape, more specifically, a long columnar shape. The rod portion 61 is provided so that one end is fixed to the bottom portion 56 of the valve member 50 and the other end is located inside the hole portion 73 of the bottom portion 72 of the spring seat portion 70.

  The rod portion 61 has a length in the axial direction that seals the end surface on the spring seat portion 70 side of the bottom portion 56 of the valve member 50 in a state where the seat portion 58 is in contact with the valve seat 42 and the bottom portion 72 of the spring seat portion 70. It is formed to be substantially the same as the distance from the end surface on the part 80 side.

  The rod portion 61 has a sliding outer wall 611 and a small diameter portion 612. The sliding outer wall 611 is formed on the outer wall at the other end of the rod portion 61. The sliding outer wall 611 has an outer diameter that is the same as or slightly smaller than the inner diameter of the hole 73 in the bottom 72 of the spring seat 70. Thereby, the sliding outer wall 611 is slidable with the inner wall of the hole portion 73 of the bottom portion 72 of the spring seat portion 70 when the rod portion 61 moves in the axial direction together with the valve member 50.

The small diameter portion 612 is formed on the valve member 50 side of the sliding outer wall 611 of the rod portion 61. The small diameter portion 612 is formed, for example, by cutting the outer wall of the rod portion 61 inward in the diameter.
The valve member 50 has a hole 561. The hole portion 561 is formed so as to connect the wall surface on the valve seat portion 40 side of the bottom portion 56 of the valve member 50 and the wall surface on the spring seat portion 70 side.

  With the above configuration, as shown in FIG. 15B, when the relief valve opens, the pressure of the fuel in the intermediate chamber 104 increases, and the valve member 50 moves away from the valve seat 40, the first The fuel in the space 101 (discharge passage 14) flows from the valve hole 41, the intermediate chamber 104, the hole 561, the inside of the cylinder part 52, the inside of the cylinder part 71, between the hole 73 and the small diameter part 612, and the spring seat part. 70 and the sealing portion 80 can be circulated to the second space 102 (fuel chamber 15) side via the second hole portion 27. As a result, the pressure of the fuel in the discharge passage 14 can be reduced.

(3rd reference form)
A relief valve according to a third embodiment of the present invention is shown in FIG.
In the third reference form, the body part 20 does not have the first hole part 25 and the hole part opening 26 shown in the first embodiment (FIG. 1).

In the third reference embodiment, the relief valve includes a pin 63. The pin 63 is formed of a metal such as stainless steel in a rod shape, more specifically, a long cone shape. One end side of the pin 63 having a large outer diameter is fixed to the valve seat portion 40.
The valve member 50 has a hole 561. The hole portion 561 is formed so as to connect the wall surface on the valve seat portion 40 side of the bottom portion 56 of the valve member 50 and the wall surface on the spring seat portion 70 side.

  The pin 63 is provided so that the other end side with a small outer diameter is located inside the hole 561 of the valve member 50 in a state where the seat portion 58 is in contact with the valve seat 42. At this time, the hole 561 is closed by the pin 63. That is, the outer wall of the pin 63 and the inner wall of the hole 561 are in contact with each other. On the other hand, when the valve member 50 moves in a direction away from the valve seat 40, the outer wall of the pin 63 and the inner wall of the hole 561 are separated (see FIG. 16B).

  With the above configuration, as shown in FIG. 16B, when the relief valve opens, the fuel pressure in the intermediate chamber 104 increases, and the valve member 50 moves away from the valve seat 40, the first The fuel in the space 101 (discharge passage 14) includes the valve hole 41, the intermediate chamber 104, the hole 561, the inside of the cylinder part 52, the inside of the cylinder part 71, the hole part 73, the spring seat part 70 and the sealing part 80. In the meantime, it becomes possible to circulate to the second space 102 (fuel chamber 15) side via the second hole portion 27. As a result, the pressure of the fuel in the discharge passage 14 can be reduced.

(4th reference form)
A relief valve according to a fourth embodiment of the present invention is shown in FIG.
In the fourth reference form, the body part 20 does not have the first hole part 25 and the hole part opening 26 shown in the first embodiment (FIG. 1).

In the fourth reference form, the body portion 20 has a tapered portion 212. The tapered portion 212 is formed in the middle of the reference inner diameter portion 22 in the axial direction. The tapered portion 212 is formed in a tapered shape so that the inner diameter becomes larger from the valve seat portion 40 side toward the spring seat portion 70 side.
Here, the sliding outer wall 55 is slidable with the reference inner diameter portion 22 of the tapered portion 212 on the valve seat portion 40 side.
The valve member 50 has a hole 522. The hole 522 is formed so as to connect the outer wall and the inner wall of the large-diameter portion 53 of the cylindrical portion 52.

  With the above configuration, as shown in FIG. 17B, when the relief valve is opened, the pressure of the fuel in the intermediate chamber 104 increases, and the valve member 50 moves away from the valve seat 40, the intermediate chamber 104 and the space inside the cylindrical portion 52 are in a state of communicating with each other via the hole portion 522 between the cylindrical portion 52 and the cylindrical inner wall 21 (tapered portion 212). Thereby, the fuel in the first space 101 (discharge passage 14) flows between the valve hole 41, the intermediate chamber 104, the cylindrical portion 52 and the cylindrical inner wall 21 (tapered portion 212), the hole portion 522, and the spring seat portion 70. , Between the spring seat portion 70 and the sealing portion 80, through the second hole portion 27, can be distributed to the second space 102 (fuel chamber 15) side. As a result, the pressure of the fuel in the discharge passage 14 can be reduced.

(5th reference form)
FIG. 18 shows a relief valve according to a fifth reference embodiment of the present invention.
In the fifth reference embodiment, the hole opening 26 of the first hole portion 25 is formed in the first large diameter portion 23. Therefore, the intermediate chamber 104 and the first hole portion 25 communicate with each other with the seat portion 58 in contact with the valve seat 42.

  In the fifth embodiment, the relief valve includes a reed valve 65. The reed valve 65 is formed of a thin metal plate such as stainless steel. The reed valve 65 is provided so as to close the opening of the first hole 25 on the fuel chamber 15 side. The outer edge of the reed valve 65 is fixed at a position away from the opening of the first hole 25 on the inner wall of the housing 11 forming the fuel chamber 15 by, for example, welding. The reed valve 65 can be elastically deformed so that a portion opposite to the portion fixed to the inner wall of the housing 11 is separated from the opening of the first hole portion 25.

  With the above configuration, as shown in FIG. 18B, when the relief valve is opened, the pressure of the fuel in the intermediate chamber 104 increases and the valve member 50 moves away from the valve seat 40, and the first The pressure of the fuel in the hole 25 increases, and the reed valve 65 opens so as to separate from the opening of the first hole 25. As a result, the fuel in the first space 101 (discharge passage 14) can flow to the second space 102 (fuel chamber 15) via the valve hole 41, the intermediate chamber 104, and the first hole 25. As a result, the pressure of the fuel in the discharge passage 14 can be reduced.

(6th reference form)
FIG. 19 shows a relief valve according to a sixth reference embodiment of the present invention.
In the sixth reference embodiment, the body portion 20 has a small diameter portion 213 instead of the first large diameter portion 23 shown in the first embodiment (FIG. 1). The small diameter portion 213 is a portion formed in a cylindrical shape so as to have an inner diameter smaller than the inner diameter of the reference inner diameter portion 22 in the cylindrical inner wall 21, and is formed on the valve seat portion 40 side of the reference inner diameter portion 22. The hole opening 26 of the first hole portion 25 is formed on the small diameter portion 213 side of the reference inner diameter portion 22.

  The small diameter portion 213 has an inner diameter set to be equal to or slightly larger than the outer diameter of the small diameter portion 54 of the valve member 50. Thereby, the outer wall of the small diameter part 54 can slide on the inner wall of the small diameter part 213. The outer wall of the large diameter portion 53 of the valve member 50 is slidable on the reference inner diameter portion 22.

In a state where the seat portion 58 is in contact with the valve seat 42, an annular space 105 that is an annular space is formed between the small diameter portion 54 of the valve member 50 and the reference inner diameter portion 22 of the body portion 20. At this time, the annular space 105 and the intermediate chamber 104 are not in communication with each other, and the annular space 105 and the first hole portion 25 are in communication with each other.
When the valve member 50 moves in a direction away from the valve seat portion 40, the intermediate chamber 104 and the annular space 105 communicate with each other (see FIG. 19B).

  With the above configuration, as shown in FIG. 19B, when the relief valve is opened, the pressure of the fuel in the intermediate chamber 104 increases and the valve member 50 moves away from the valve seat 40, and the intermediate chamber 104 is moved. And the annular space 105 communicate with each other. As a result, the fuel in the first space 101 (discharge passage 14) flows to the second space 102 (fuel chamber 15) side via the valve hole 41, the intermediate chamber 104, the annular space 105, and the first hole 25. It becomes possible. As a result, the pressure of the fuel in the discharge passage 14 can be reduced.

  Further, in the sixth reference embodiment, the outer edge portion of the hole opening 26 does not slide with any of the outer wall (sliding outer wall 55) of the large diameter portion 53 and the outer wall of the small diameter portion 54. Therefore, wear of the outer edge portion of the hole opening 26 can be suppressed. Further, it is possible to suppress malfunction (valve opening failure) of the valve member 50 due to the outer wall of the large-diameter portion 53 (sliding outer wall 55) or the outer wall of the small-diameter portion 54 being caught by the outer edge or inner edge of the hole opening 26.

(Other embodiments)
In another embodiment of the present invention, the body part and the valve seat part may be formed separately.
Moreover, in the above-mentioned embodiment, the coil spring as an urging | biasing member was provided between the valve member and the spring seat part, and the example which urges | biases a valve member to the valve seat side was shown. On the other hand, in another embodiment of the present invention, for example, an urging member such as a leaf spring may be provided between the valve member and the body portion, and the valve member may be urged toward the valve seat.

  In the above-described embodiment, when the movement restricting portion restricts the movement of the valve member toward the spring seat portion, that is, when the valve member and the movement restricting portion (spring seat portion) are in contact with each other, An example is shown in which the overlapping area between the opening and the sliding outer wall is 0, and the minimum flow path area between the intermediate chamber and the hole is the same as the area of the hole opening. On the other hand, in another embodiment of the present invention, when the movement restricting portion restricts the movement of the valve member toward the spring seat portion, the overlapping area of the hole opening and the sliding outer wall is larger than 0. The minimum flow area between the intermediate chamber and the hole may be larger than 0 and smaller than the area of the hole opening. This configuration can be realized, for example, by appropriately moving and fixing the position of the movement restricting portion (spring seat portion) of the above-described embodiment to the valve seat portion side. In this way, the maximum value of the minimum flow path area between the intermediate chamber and the hole is set to a value smaller than the area of the hole opening by appropriately setting the position of the valve member that can be restricted by the movement restricting part. be able to.

  Moreover, in the above-mentioned embodiment, the example in which a movement control part and a spring seat part were formed integrally was shown. On the other hand, in other embodiment of this invention, the movement control part may be formed separately from the spring seat part. Further, the movement restricting portion may be formed integrally with the body portion. In another embodiment of the present invention, the relief valve may not include a movement restricting portion.

  In another embodiment of the present invention, the shape of the hole opening is not limited to a perfect circle, a rectangle, and a triangle, and may be formed in any shape such as an ellipse or a polygon having five or more corners. Regardless of the shape of the hole opening, as the edge of the sliding outer wall on the valve seat side moves on the hole opening to the spring seat side, the hole opening and the sliding outer wall As the overlapping area gradually decreases, the minimum flow path area between the intermediate chamber and the hole gradually increases.

  In the above-described embodiment, the relief valve is connected to the discharge passage at the end opposite to the intermediate chamber of the valve hole, and the end opposite to the intermediate chamber 104 of the hole (first hole 25). The example which provided in a high pressure pump so that a part might connect to the fuel chamber 15 was shown. On the other hand, in another embodiment of the present invention, the relief valve has a valve hole connected to the discharge passage, and a hole (first hole 25) is formed between the pressurizing chamber 12 (the intake valve 16 and the discharge valve 17). It is good also as providing in a high pressure pump so that it may connect to the space between.

  Moreover, in the above-mentioned embodiment, the example which forms the body part of a relief valve integrally with the housing of a high pressure pump was shown. On the other hand, in another embodiment of the present invention, the body portion of the relief valve may be formed separately from the housing of the high pressure pump. Moreover, it is good also as providing a relief valve in the position away from the housing independently.

  The relief valve may be provided so that the valve hole is connected to a space in the pipe 5 or a space in the fuel rail 6 which is a space communicating with the discharge passage. The relief valve is provided so that a hole (first hole 25) is connected to a space in the intake passage or a space in the pipe 4 and a space in the fuel tank 2 that communicates with the intake passage. May be. Further, the relief valve may be provided so that the hole (first hole 25) is connected to the space on the atmosphere side, that is, opened to the atmosphere. In this case, the space on the atmosphere side corresponds to the “second space”.

The relief valve of the present invention can be applied not only to a high-pressure pump of a vehicle but also to other devices and the like as long as the valve hole is connected to a space where the fluid can be at a high pressure.
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 ... Relief valve 20 ... Body part 21 ... Cylindrical inner wall 25 ... 1st hole part (hole part)
26: Hole opening 40 ... Valve seat 41: Valve hole 42 ... Valve seat 50 ... Valve member 51 ... Valve body 55 ... Sliding outer wall 58 ... Seat Part 60 ... biasing member

Claims (5)

A relief valve (1) provided to connect to the first space (101) and the second space (102) which is a space different from the first space, and capable of reducing the fuel pressure in the first space. Because
A cylindrical inner wall (21) that is a cylindrical inner wall, a first hole (25) that is formed to connect the inner space (103) that is a space inside the cylindrical inner wall and the second space, A second hole (27) formed at a location different from the first hole so as to connect the inner space and the second space, and an opening of the first hole formed in the cylindrical inner wall A body part (20) having a hole opening (26) which is
One end of the cylindrical inner wall is closed, and a valve hole (41) formed so as to connect the inner space and the first space, and an annular outer side of the end portion of the valve hole on the inner space side A valve seat (40) having a formed valve seat (42);
A valve body (51) provided so as to be reciprocally movable in the inner space in the inner space, a sliding outer wall (55) which is an outer wall sliding on the cylindrical inner wall of the outer wall of the valve body, and the valve body A seat portion (58) that is formed on the valve seat side and is capable of contacting the valve seat, and the volume changes according to the axial position of the valve body with respect to the cylindrical inner wall, and the valve hole and the An intermediate chamber (104) capable of communicating with one hole is formed between the cylindrical inner wall and the valve seat, and the valve hole communicates with the intermediate chamber when the seat is separated from the valve seat. A valve member (50) that shuts off the valve hole and the intermediate chamber when the seat portion comes into contact with the valve seat;
An urging member (60) for urging the valve member toward the valve seat portion;
A pressurizing chamber (12) for sucking and pressurizing fuel, a suction passage (13) through which fuel sucked into the pressurizing chamber flows, and a discharge passage (14) through which fuel pressurized and discharged in the pressurizing chamber flows And a housing (11) having
The valve member has at least an overlapping area (where the hole opening and the sliding outer wall overlap as the valve member moves in a direction away from the valve seat portion) within an axially movable range. A specific range in which the minimum flow path area (Sf), which is the minimum flow path area between the intermediate chamber and the first hole portion, gradually increases as Sp) gradually decreases,
The first space is a space in the discharge passage, or a space communicating with the discharge passage,
The second space is a space including the pressurizing chamber,
The second hole portion is a high-pressure pump that is formed so as to connect the second space and a space on the opposite side of the intermediate chamber from the valve body in the inner space.   The high-pressure pump according to claim 1, wherein the intermediate chamber and the first hole portion are not in communication when the seat portion is in contact with the valve seat.   The high pressure pump according to claim 1 or 2, further comprising a movement restricting portion (74) capable of restricting movement of the valve member in a direction away from the valve seat portion.   The said valve member has a recessed part (59) formed so that it may dent in the radial direction from the said sliding outer wall in the position corresponding to the said hole part opening in the state which the said sheet | seat part contact | abutted to the said valve seat. The high-pressure pump as described in any one of 1-3.   The high-pressure pump according to any one of claims 1 to 4, wherein the hole opening is formed in a circular shape, a rectangular shape, or a triangular shape.

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