JP2009293491A - High pressure fuel pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure fuel pump with high sealing performance. <P>SOLUTION: The high pressure fuel pump 3 pressurizing low pressure fuel and supplying it to an exterior is equipped with a body 70 having an opening 75a for communicating the fuel, and a fitting part 77 annularly projecting from a periphery of the opening 75a, a cylindrically formed lid body 40 wherein a seal part 45 is formed by fitting and joining of an inner circumference face 43a of a circumferential wall part 43 to an outer circumferential face 77a of the fitting part 77 to seal the opening 75a, and a regulating structure 90 regulating deformation to a radial outer side in regard to an end 43c of a body 70 side of the circumferential wall part 43. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high-pressure fuel pump that pressurizes low-pressure fuel and supplies it to the outside.

  Conventionally, a high-pressure fuel pump including a body having an opening through which fuel to be pressurized flows and a lid that covers the opening is known. For example, Patent Document 1 discloses a high-pressure fuel pump in which a seal portion using an O-ring is provided between a body and a lid to prevent leakage of fuel to the outside.

However, since the seal portion using the O-ring as in Patent Document 1 cannot completely seal the fuel, a part of the fuel vaporized inside the high-pressure fuel pump may leak to the outside. For this reason, it is not possible to satisfy recent emission regulations that require zero leakage of vaporized fuel.
Japanese Patent Application Laid-Open No. 2007-162677

  In order to meet the above emission regulations, the present inventors have conducted research on a technique that eliminates the leakage of vaporized fuel by changing to a seal portion that joins the body and the lid. As a result, a fitting portion that protrudes in an annular shape from the periphery of the opening portion is provided on the body, and a peripheral wall portion that is joined by being joined to the outer peripheral surface of the fitting portion is provided on the cylindrical lid body. A configuration has been conceived in which a sealing portion is formed by the joining to cover the opening.

  However, as a result of further diligent research by the present inventors, in the configuration in which the fitting portion of the body and the peripheral wall portion of the lid are joined, the lid is affected by the pressure of the circulating fuel in the opening covered by the lid. It has been found that a problem arises when an axial force acts on the. The problem is that due to the action of the axial force, stress concentrates on the seal portion that joins the body and the lid, and the end of the peripheral wall portion on the body side is deformed radially outward. This deformation compresses the peripheral wall portion in the vicinity of the seal portion and causes the seal portion to peel off. Here, since the pressure of the fuel flowing through the opening acts on the lid for a long time, the fatigue strength is reduced in the stress-concentrated seal portion, and the sealing performance of the seal portion is deteriorated.

  The present invention has been made in view of the above problems, and an object thereof is to provide a high-pressure fuel pump with improved sealing performance.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a high-pressure fuel pump that pressurizes low-pressure fuel and supplies the fuel to the outside. A body having a protruding fitting portion and a cylindrical shape are formed, and the inner peripheral surface of the peripheral wall portion is fitted and joined to the outer peripheral surface of the fitting portion, thereby forming a seal portion and covering the opening portion. It is characterized by comprising a lid and a regulating structure that regulates deformation toward the radially outer side of the end of the peripheral wall on the body side.

  According to this invention, the lid that covers the opening of the body receives an axial force due to the pressure of the fuel flowing through the opening. Here, the seal portion formed by fitting and joining the inner peripheral surface of the peripheral wall portion of the cylindrical lid body to the outer peripheral surface of the fitting portion around the opening portion of the body has an axial force applied to the lid body. The stress is concentrated by the action, whereby the body side end portion of the peripheral wall portion tends to be deformed by receiving a force on the radially outer side. However, since the deformation of the peripheral wall portion toward the outer side in the radial direction is restricted by the restriction structure, peeling of the seal portion due to the compression of the peripheral wall portion in the vicinity of the seal portion is suppressed by the deformation. Will be. Therefore, even if the pressure of the fuel flowing through the opening acts for a long period of time, the fatigue strength of the seal portion where stress is concentrated can be secured and high sealing performance can be realized.

  In the invention described in claim 2, the restricting structure has a joint portion for joining the body side end portion of the peripheral wall portion to the body. According to the present invention, the end portion of the peripheral wall portion joined to the body is reliably restricted from being deformed by the radially outer force. Therefore, it is possible to realize high sealing performance by making it difficult for the seal portion to peel off sufficiently.

  In the third aspect of the invention, the body forms an abutting surface with which the end surface on the body side of the end portion of the peripheral wall abuts, and the joining portion joins the end surface to the abutting surface. In the configuration in which the body side end surface of the peripheral wall portion is joined to the abutting surface of the body as in the present invention, the force to deform the peripheral wall end portion radially outward is the shear direction with respect to the joint portion. Acts as a force. In general, since the joint portion has high strength in the shearing direction, the radially outward deformation occurring at the end portion of the peripheral wall portion is more reliably regulated. Therefore, the seal part can be prevented from peeling off and the sealing performance can be further enhanced.

  In the invention according to claim 4, since the joint portion is formed over the entire circumference of the end portion on the body side of the peripheral wall portion, the deformation of the end portion toward the radially outer side is more reliably regulated. . Therefore, the seal part can be prevented from peeling off and the sealing performance can be further enhanced.

  In a fifth aspect of the present invention, the restriction structure includes an auxiliary seal portion that joins the inner peripheral surface of the peripheral wall portion to the outer peripheral surface of the fitting portion on the end side of the seal portion. According to this invention, the stress concentrated on the seal portion by the axial force on the lid is dispersed by the auxiliary seal portion. Further, since a part of the stress due to the axial force acts on the auxiliary seal portion located on the end side with respect to the seal portion, the radially outer force received by the body side end portion of the peripheral wall portion is reduced. is there. Therefore, the end portion of the peripheral wall portion joined to the body is reliably restricted from being deformed by the radially outer force. Therefore, it is possible to realize high sealing performance by making it difficult for the seal portion to peel off sufficiently.

  In the invention according to claim 6, the restricting structure includes a convex portion provided on one of the body side end and the body of the peripheral wall portion, and a concave portion provided on the other of the peripheral wall end portion and the body and into which the convex portion is fitted. Have. According to the present invention, the body-side end portion of the peripheral wall portion and one convex portion of the body are fitted into the other concave portion, so that the deformation of the end portion due to the radially outer force is reliably regulated. Therefore, it is possible to realize high sealing performance by making it difficult for the seal portion to peel off sufficiently.

  In the invention according to claim 7, since the convex portion and the concave portion provided on one side and the other side of the body side end portion and the body of the peripheral wall portion are formed over the entire circumference of the end portion, the radial direction of the end portion The outward deformation is more reliably regulated. Therefore, the seal part can be prevented from peeling off and the sealing performance can be further enhanced.

  In the invention according to claim 8, the restricting structure has a ring member whose inner peripheral surface is fitted to the outer peripheral surface of the body side end of the peripheral wall portion. According to this invention, the ring member whose inner peripheral surface is fitted to the outer peripheral surface of the body-side end portion of the peripheral wall portion reliably restricts the outward deformation in the radial direction that occurs at the end portion. Therefore, it is possible to realize high sealing performance by making it difficult for the seal portion to peel off sufficiently.

  In the invention according to claim 9, the restricting structure has a projecting portion projecting in the radial direction from the body side end portion of the peripheral wall portion. According to this invention, the radial rigidity of the said edge part improves by the protrusion part which protrudes in the radial direction from the body side edge part of a surrounding wall part. As a result, even when a radially outward force is generated at the end portion of the peripheral wall portion, the deformation amount of the end portion is reduced. Therefore, peeling of the seal portion is difficult to occur, which can contribute to improvement of the sealing performance.

  In the invention described in claim 10, the protruding portion protrudes radially outward from the body side end portion of the peripheral wall portion, and the body-side end surface of the protruding portion is supported by the body. According to the present invention, the body-side end surface of the protruding portion that protrudes radially outward from the end portion of the peripheral wall portion is supported by the body, so that deformation to the radially outer side that occurs at the end portion is reliably restricted. . Therefore, it is possible to realize high sealing performance by making it difficult for the seal portion to peel off sufficiently.

  In the invention according to claim 11, the protruding portion protrudes radially inward from the body side end of the peripheral wall portion and is locked by the body. According to the present invention, the protruding portion protruding radially inward from the end portion of the peripheral wall portion is locked by the body, so that the deformation of the fitting portion generated at the end portion toward the radially outer side is reliably restricted. . Therefore, it is possible to realize high sealing performance by making it difficult for the seal portion to peel off sufficiently.

  In the invention according to claim 12, since the projecting portion is formed over the entire circumference of the end portion on the body side of the peripheral wall portion, the deformation of the end portion in the radial direction is more reliably regulated. Therefore, the seal part can be prevented from peeling off and the sealing performance can be further enhanced.

  In the thirteenth aspect, the body and the lid jointly form a pressurizing chamber for pressurizing the fuel downstream of the opening. According to this invention, the pressure of the fuel in the pressurizing chamber that pressurizes the fuel downstream of the opening is higher than the pressure of the fuel in the opening. Therefore, since the high fuel pressure in the pressurizing chamber acts in addition to the fuel pressure in the opening on the lid that forms the pressurizing chamber in cooperation with the body, the axial force acting on the lid As a result, the radially outer force acting on the end portion of the peripheral wall portion is increased. However, since the deformation of the end portion of the peripheral wall portion in the radial direction is restricted by the presence of the restriction structure, peeling of the seal portion is suppressed and high sealing performance is realized.

  The invention according to claim 14 includes an electromagnetic valve having a valve member for controlling the amount of fuel supplied, and the valve member is inserted into the opening. When the valve member for controlling the fuel supply amount is inserted into the opening as described above, the opening is likely to become large. Therefore, the contact area between the lid and the fuel increases, the axial force acting on the lid increases, and the radially outward force of the fitting portion generated at the end also increases. However, as described above, since the deformation of the end portion in the radial direction can be restricted according to the action of the restriction structure, as a lid that covers the opening into which the valve member of the electromagnetic valve is inserted, The invention according to claim 14 is particularly suitable.

  In the invention according to claim 15, the electromagnetic valve is held by a lid made of a magnetic material, and has a coil portion that drives the valve member by forming a magnetic circuit in the lid by energization. It is formed by welding the inner peripheral surface of the peripheral wall portion and the outer peripheral surface of the fitting portion, and is located on the body side with respect to the coil portion. According to the present invention, the magnetic characteristic of the lid made of a magnetic material is likely to change due to welding heat when forming the seal portion, so that the coil portion drives the valve member by forming a magnetic circuit in the lid body. In the electromagnetic valve having the configuration, there is a concern that the driving accuracy of the electromagnetic valve is deteriorated. However, since the seal portion is positioned on the body side with respect to the coil portion, the magnetic circuit formed on the lid body by the coil portion can be prevented from being affected by the welding heat at the time of forming the seal portion.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
A fuel supply system 1 using a high-pressure fuel pump according to a first embodiment of the present invention is shown in FIG. The fuel supply system 1 of the present embodiment is a so-called direct injection gasoline supply system that directly injects fuel into a cylinder of an internal combustion engine 7 (for example, a gasoline engine).

  The fuel supply system 1 includes a low pressure fuel pump 2, a high pressure fuel pump 3, a delivery pipe 4, a fuel injection valve 5, and the like.

  The low-pressure fuel pump 2 is an electric pump that pumps up fuel in the fuel tank 6 and supplies it to the high-pressure fuel pump 3. The high-pressure fuel pump 3 is a plunger pump having a plunger 11 and a pressurizing chamber 18, and pressurizes the low-pressure (about 400 kPa) fuel supplied from the low-pressure fuel pump 2 in the pressurizing chamber 18, thereby providing an external delivery. Supply to pipe 4. The high-pressure fuel pump 3 includes a discharge valve 20 that opens when the pressure of the fuel pressurized in the pressurizing chamber 18 exceeds a predetermined pressure (about 40 MPa) and supplies high-pressure fuel to the delivery pipe 4. ing. The delivery pipe 4 accumulates fuel whose pressure has been increased by the high-pressure fuel pump 3. The delivery pipe 4 is connected with a fuel injection valve 5 provided for each cylinder of the internal combustion engine 7. The fuel injection valve 5 injects high-pressure fuel supplied from the delivery pipe 4 into a combustion chamber formed in each cylinder.

(Basic configuration)
The configuration of the high-pressure fuel pump 3 according to the first embodiment of the present invention will be described in detail with reference to FIG. The high-pressure fuel pump 3 includes a body 70, a cover 80, a plunger 11, a metering valve 50, a discharge valve 20, and the like.

  The body 70 is made of hardened steel or the like. A cylinder 71 is formed on the body 70, and a sliding surface 71a of the cylinder 71 supports the plunger 11 so as to be able to reciprocate. The sliding surface 71a of the cylinder 71 is formed by being hardened by induction hardening or the like. The body 70 has a pipe joint (not shown) connected to the low-pressure fuel pump 2 (see FIG. 1) and a metering valve 50 attached to the fuel inlet side, and a discharge valve 20 attached to the fuel outlet side. Yes.

  In the body 70, a suction passage 72, a pressurizing chamber 18, a discharge passage 73, a relief passage 74, and the like are formed. A suction chamber 81 is formed above the body 70 between the upper end portion of the body 70 and the cover 80. An outlet portion 73 a is formed on the fuel outlet side of the discharge passage 73. The suction passage 72 is a passage connecting the suction chamber 81 and the pressurization chamber 18. The discharge passage 73 is a passage connecting the pressurizing chamber 18 and the outlet portion 73a. The escape passage 74 is a passage connecting the cylinder 71 and the suction chamber 81.

  In the middle of the suction passage 72, a housing portion 75 for housing the metering valve 50 is formed. The bottom portion of the accommodating portion 75 is connected to the suction passage 72 on the pressurizing chamber 18 side, and the inner peripheral portion of the accommodating portion 75 is connected to the suction passage 72 on the suction chamber 81 side. An opening 75a is formed on the fuel inlet side of the accommodating portion 75, and low-pressure fuel flows through the opening 75a. A fitting portion 77 that protrudes in an annular shape from the periphery of the opening 75a is provided around the opening 75a. The discharge passage 73 is formed with a storage portion 76 that stores the discharge valve 20.

  The pressurizing chamber 18 is formed on one end side in the reciprocating direction of the plunger 11 supported so as to be reciprocally movable on the sliding surface 71 a of the cylinder 71. A head 12 formed at the other end of the plunger 11 is coupled to a spring seat 13. A spring 15 is provided between the spring seat 13 and the body 70.

  The spring seat 13 is pressed against the bottom inner wall of the tappet 14 by the urging force of the spring 15. When the bottom outer wall of the tappet 14 slides with the cam 16 as the cam 16 rotates, the plunger 11 reciprocates.

  An oil seal 17 is provided at the end of the sliding surface 71 a opposite to the pressurizing chamber 18. The oil seal 17 prevents oil and the like from entering the pressurizing chamber 18 from the outside, and prevents fuel leakage from the pressurizing chamber 18 to the outside. The fuel leaked from the sliding portion of the plunger 11 and the body 70 to the oil seal 17 side is returned from the escape passage 74 to the suction chamber 81 on the low pressure side. Thereby, it can suppress that a high fuel pressure is added to the oil seal 17.

  The metering valve 50 includes a connector 40, a valve member 52, a valve closing spring 53, a spring seat 54, an electromagnetic driving unit 60, and the like. Here, the metering valve 50 corresponds to the electromagnetic valve recited in the claims, and is a valve that controls the amount of fuel supplied from the suction chamber 81 to the pressurizing chamber 18. A part of the connector 40, the valve member 52, the valve closing spring 53 and the spring seat 54 are inserted into the body 70 through the opening 75 a and are accommodated in the accommodating portion 75.

  The connector 40 is formed into a bottomed cylindrical shape as a whole by electromagnetic stainless steel or the like, which is a magnetic material, and includes a valve housing portion 41, a bottom wall portion 42, a peripheral wall portion 43, a connecting portion 44, a seal portion 45, a holding portion 46, and the like. have. The connector 40 corresponds to the lid described in the claims.

  The bottom wall portion 42 of the connector 40 covers the opening 75 a of the housing portion 75. From the bottom wall portion 42, a valve housing portion 41 and a connecting portion 44 project in a cylindrical shape. The front end side protruding in a cylindrical shape is the valve housing portion 41, and the bottom wall portion 42 side is the connecting portion 44. The tip of the valve housing part 41 forms a pressurizing chamber 18 for further pressurizing low-pressure fuel downstream of the opening 75a in cooperation with the body 70, and the pressure of the fuel generated in the pressurizing chamber 18 is determined by the valve housing part. It acts on the bottom wall portion 42 via 41 and the connecting portion 44. A valve seat 41 a on which the valve member 52 can be seated is formed in a projecting annular convex shape on the inner peripheral portion of the valve housing portion 41. The connecting portion 44 has a plurality of radial through holes 44 a that are fuel passages for communicating the accommodating portion 75 with the pressurizing chamber 18.

  In the connector 40, the inner peripheral surface 43a of the peripheral wall 43 that protrudes in a cylindrical shape toward the body 70 along the axial direction from the bottom wall 42 formed in a disk shape is an annular shape around the opening 75a in the body 70. Are fitted on the outer peripheral surface 77a of the fitting portion 77 and joined by laser welding. By this joining, an annular seal portion 45 is formed between the inner peripheral surface 43 a of the peripheral wall portion 43 and the outer peripheral surface 77 a of the fitting portion 77. The seal portion 45 seals between the body 70 and the connector 40, and holds the connector 40 on the body 70. Further, an annular holding portion 46 is formed on the outer surface of the bottom wall portion 42 of the connector 40 so as to protrude to the opposite side of the body 70 in the axial direction.

  The valve member 52 is formed in a bottomed cylindrical shape, and is accommodated in the valve housing portion 41 so that the bottom portion is seated on the valve seat 41a. A valve closing spring 53 is accommodated on the inner peripheral side of the valve member 52. One end portion of the valve closing spring 53 is supported by a spring seat 54 attached to the valve housing portion 41, and the other end portion is supported by the bottom portion of the valve member 52. The valve member 52 is pressed in the direction in which the valve member 52 is seated on the valve seat 41 a by the urging force of the valve closing spring 53. When the valve member 52 is seated on the valve seat 41a, the communication between the suction chamber 81 and the pressurizing chamber 18 is blocked.

  The electromagnetic drive unit 60 includes a fixed core 62, a movable core 63, a drive rod 64, a valve opening spring 65, a coil unit 66, an electrical connector 67, and the like. The electromagnetic drive unit 60 is connected to the holding unit 46 of the connector 40 and is held by the body 70 via the connector 40.

  The fixed core 62 is made of a magnetic material and has a suction part 62a. A movable core 63 made of a magnetic material is provided on the fixed core 62 on the suction portion 62a side. The movable core 63 is coupled to a drive rod 64 provided so as to penetrate the bottom wall portion 42 of the connector 40. The attracting part 62 a attracts the movable core 63 by a magnetic attractive force generated between the attracting part 62 a and the movable core 63. The tip of the drive rod 64 is in contact with the valve member 52, and the valve member 52 is movable in the separation / seating direction when the drive rod 64 reciprocates together with the movable core 63.

  A valve opening spring 65 is provided between the fixed core 62 and the movable core 63. The biasing force of the valve opening spring 65 is larger than the biasing force of the valve closing spring 53. For this reason, the movable core 63 moves in a direction away from the fixed core 62 when the magnetic attraction force is not generated in the attraction portion 62a. That is, the valve member 52 is moved in the direction away from the valve seat 41a. As a result, the suction chamber 81 and the pressurizing chamber 18 communicate with each other.

  The coil portion 66 is provided on the outer peripheral side of the fixed core 62. An electrical connector 67 that supplies electric power to the coil unit 66 is provided on the outer peripheral side of the coil unit 66. When electric power is supplied to the coil portion 66 from the outside, a magnetic circuit passing through the fixed core 62 and the movable core 63 is formed, and a magnetic attraction force acts between the attraction portion 62 a and the movable core 63. Due to the generation of the magnetic attractive force, the movable core 63 moves to the fixed core 62 side, and the valve member 52 is seated on the valve seat 41a. As a result, the communication between the suction chamber 81 and the pressurizing chamber 18 is blocked.

  The discharge valve 20 has a valve seat 21, a valve body 22, a stopper 23, and a spring 24, and is accommodated in an accommodating portion 76 formed in the discharge passage 73. The valve seat 21 is formed on the inner peripheral portion of the discharge passage 73. The valve body 22 is formed in a cylindrical shape, and is provided closer to the outlet 73 a than the valve seat 21. The valve body 22 has a large diameter portion 22a and a small diameter portion 22b. The large diameter portion 22a is slidably supported by the discharge passage 73. The small-diameter portion 22b is provided closer to the pressurizing chamber 18 than the large-diameter portion 22a, and the tip of the small-diameter portion 22b is seated on the valve seat 21 when the valve body 22 moves to the pressurizing chamber 18 side.

  A plurality of through holes 22d are formed in the peripheral wall portion of the small diameter portion 22b to allow the fuel passage 22c formed inside the valve body 22 to communicate with the accommodating portion 76. Thereby, when the valve body 22 is separated from the valve seat 21, the fuel that has flowed into the gap between the small diameter portion 22b and the discharge passage 73 passes through the through hole 22d and flows into the fuel passage 22c, and the outlet portion. It flows toward 73a.

  The stopper 23 is formed in a cylindrical shape, and is provided closer to the outlet portion 73a than the valve body 22. The stopper 23 is fixed to the discharge passage 73 and restricts the movement of the valve body 22 toward the outlet portion 73a. The spring 24 is provided between the stopper 23 and the large diameter portion 22 a of the valve body 22. The spring 24 biases the stopper 23 and the valve body 22 so as to separate them. Thereby, the small diameter part 22b of the valve body 22 is seated on the valve seat 21, and the communication between the pressurizing chamber 18 and the outlet part 73a is blocked.

  When a differential pressure is generated between the pressurizing chamber 18 side and the outlet portion 73a side of the valve body 22 and the force acting on the tip of the small diameter portion 22b of the valve body 22 exceeds the urging force of the spring 24, the valve body 22 The pressure chamber 18 and the outlet portion 73a communicate with each other by separating from the valve seat 21. Here, the stopper 23 is fixed to the discharge passage 73 by press fitting or the like. By adjusting the position of the stopper 23 in the discharge passage 73, the moving amount of the valve body 22 and the set load of the spring 24 can be adjusted.

  The operation of the high-pressure fuel pump 3 configured as described above will be described.

(1) Suction stroke When the plunger 11 descends, power is not supplied to the coil portion 66 of the metering valve 50. When the plunger 11 descends, the fuel pressure in the pressurizing chamber 18 decreases, and the fuel in the suction chamber 81 is sucked into the pressurizing chamber 18 through the suction passage 72. The energization of the coil portion 66 of the metering valve 50 is in a state of being turned off until the plunger 11 reaches the bottom dead center.

(2) Return stroke Even when the plunger 11 rises from the bottom dead center toward the top dead center, the energization to the coil portion 66 is turned off. For this reason, the fuel in the pressurizing chamber 18 is returned to the suction chamber 81 through the metering valve 50.

(3) Pressurization stroke When energization of the coil portion 66 is turned on during the return stroke, a magnetic attractive force is generated in the attracting portion 62a of the fixed core 62, and the movable core 63 is attracted to the attracting portion 62a. As a result, the valve member 52 is seated on the valve seat 41a, the communication between the pressurizing chamber 18 and the suction chamber 81 is cut off, and the flow of fuel from the pressurizing chamber 18 to the suction chamber 81 is stopped.

  In this state, when the plunger 11 further rises toward the top dead center, the fuel in the pressurizing chamber 18 is pressurized and the fuel pressure rises. Then, the fuel pressure in the pressurizing chamber 18 increases. When the fuel pressure in the pressurizing chamber 18 becomes equal to or higher than a predetermined pressure, the valve element 22 is separated from the valve seat 21 against the biasing force of the spring 24, and the discharge valve 20 is opened. Thereby, the fuel pressurized in the pressurization chamber 18 is discharged from the exit part 73a. The fuel discharged from the outlet 73a is supplied to the delivery pipe 4 (see FIG. 1).

  By repeating the steps (1) to (3), the high-pressure fuel pump 3 pressurizes and supplies the sucked fuel. The fuel discharge amount is adjusted by controlling the energization timing to the coil portion 66 of the metering valve 50 and increasing or decreasing the amount of fuel supplied from the suction chamber 81 to the pressurizing chamber 18.

(Characteristic part)
Hereinafter, the characteristic part of 1st Embodiment is demonstrated.

  As shown in FIG. 3, a restriction structure 90 is provided on the end portion 43 c side of the body 70 side of the seal portion 45 in which the inner peripheral surface 43 a of the peripheral wall portion 43 is fitted and joined to the outer peripheral surface 77 a of the fitting portion 77. A certain joint 91 is formed. The body 70 of the present embodiment is provided with a contact surface 70a with which the end surface 43d of the end portion 43c of the peripheral wall portion 43 contacts. The joining portion 91 is formed over the entire circumference of the end portion 43c by joining the end surface 43d of the peripheral wall portion 43 on the body 70 side to the contact surface 70a by laser welding. In addition, as shown in FIG. 2, the seal portion 45 and the joint portion 91 formed by welding in the present embodiment are located closer to the body 70 than the coil portion 66.

  Here, the stress generated in the seal portion 45 when the restriction structure 90 is not provided as shown in FIG. 4 will be described. The bottom wall portion 42 of the connector 40 covering the opening portion 75a of the body 70 receives an axial force due to the pressure of the fuel flowing through the opening portion 75a. In addition, the bottom wall portion 42 of the connector 40 receives an axial force from the tip of the valve housing portion 41 via the connecting portion 44 due to the pressure of fuel in the pressurizing chamber 18 (see FIG. 2). . A total sum of these forces received from the fuel pressure is defined as an axial force P acting on the connector 40 in the axial direction. Stress due to the axial force P concentrates on the seal portion 45 formed by joining the peripheral wall portion 43 and the fitting portion 77, and the end portion 43c on the body 70 side of the peripheral wall portion 43 is deformed radially outward. (Arrow D in FIG. 4). Due to this deformation, the peripheral wall portion 43 in the vicinity of the seal portion 45 is compressed, which causes the seal portion 45 to peel off.

  However, as shown in FIG. 3, in the present embodiment, the end portion 43 c on the body 70 side of the peripheral wall portion 43 is joined to the body 70 by the joining portion 91, so that the end portion 43 c is radially outward. Deformation is restricted. Therefore, the peripheral wall part 43 in the vicinity of the seal part 45 is not compressed, and the peeling of the seal part 45 is suppressed. Therefore, even if the pressure due to the fuel flowing through the opening 75a acts for many years, the fatigue strength of the seal portion 45 where stress is concentrated can be ensured and high sealing performance can be realized.

  In the present embodiment, the joining portion 91 joins the end surface 43d of the peripheral wall portion 43 on the body 70 side with the abutting surface 70a with which the end surface 43d abuts, thereby deforming the end portion 43c radially outward. Can be applied as a force in the shearing direction to the joint 91. Since the joint portion by welding has high strength in the shear direction, the joint portion 91 can surely regulate the radially outward deformation generated in the end portion 43c by joining the end surface 43d and the contact surface 70a. is there.

  Further, in the present embodiment, the joint portion 91 formed over the entire circumference of the end portion 43c on the body 70 side in the peripheral wall portion 43 further reliably restricts the deformation of the end portion 43c of the peripheral wall portion 43 to the radially outer side. be able to.

  Further, in the present embodiment shown in FIG. 2, the connector 40 has a pressure of the fuel in the pressurizing chamber 18 that is, for example, about 40 MPa, which is a high pressure, for example, about 400 kPa, compared to the pressure of the fuel around the low-pressure opening 75a. Receive. Therefore, the axial force P (see FIG. 3) acting on the connector 40 increases, and the radially outward force generated at the end 43c of the peripheral wall 43 increases. However, peeling of the seal portion 45 is suppressed by the joint portion 91 which is a restriction structure 90 that restricts deformation of the end portion 43c to the radially outer side, and high sealing performance is realized.

  In addition, in the present embodiment, the valve member 52 of the metering valve 50 for controlling the amount of fuel supply is inserted into the opening 75a and housed inside the housing 75, so the area of the opening 75a Is easy to make large. By increasing the area of the opening 75a, the contact area between the bottom wall 42 of the connector 40 and the pressurized fuel increases, and the axial force P (see FIG. 3) acting on the bottom wall 42 increases. The radially outer force generated at the end 43c of the peripheral wall 43 is increased. However, the peeling of the seal portion 45 is suppressed by the joint portion 91 which is the restriction structure 90, and high sealing performance is realized.

  Further, the magnetic characteristics of the connector 40 change due to welding heat when the seal portion 45 is formed. In the present embodiment, the coil portion 66 of the electromagnetic drive unit 60 is configured to form a magnetic circuit in the connector 40 by energization and to drive the movable core 63. There is a concern that the drive accuracy of the drive unit 60 may deteriorate. However, since the seal portion 45 and the joining portion 91 are located on the body 70 side with respect to the coil portion 66, the influence of welding heat on the formation of the seal portion 45 on the magnetic circuit formed on the connector 40 by the coil portion 66. It is possible not to reach.

(Second Embodiment)
As shown in FIG. 5, the second embodiment of the present invention is a modification of the first embodiment. The restriction structure 90 of the second embodiment is configured by a convex portion 92 a provided at the end portion 43 c on the body 70 side of the peripheral wall portion 43 and a concave portion 92 b provided on the body 70. The convex portion 92a and the concave portion 92b are provided over the entire circumference of the end portion 43c and the body 70, and each has an annular shape. And the convex part 92a by the side of the connector 40 is fitted in the recessed part 92b by the side of the body 70 along an axial direction, and the deformation | transformation to the radial direction outer side of the surrounding wall part 43 end comes to be controlled reliably. ing.

  Therefore, even if an axial force P in the axial direction acts on the bottom wall portion 42 of the connector 40, the seal portion 45 is hardly peeled off and high sealing performance can be obtained.

(Third embodiment)
As shown in FIG. 6, the third embodiment of the present invention is a modification of the second embodiment. The restriction structure 90 of the third embodiment includes a convex portion 93 a provided on the body 70 and a concave portion 93 b provided on the end portion 43 c on the body 70 side of the peripheral wall portion 43. The convex portion 93a and the concave portion 93b are provided over the entire circumference of the body 70 and the end portion 43c, and each has an annular shape. And the convex part 93a fits in the recessed part 93b along an axial direction, and the deformation | transformation to the radial direction outer side of the surrounding wall part 43 end part 43c is controlled reliably. This makes it difficult for the seal portion 45 to be peeled off by the axial force P acting on the bottom wall portion 42 of the connector 40, and high sealing performance can be obtained.

(Fourth and fifth embodiments)
As shown in FIGS. 7 and 8, the fourth and fifth embodiments of the present invention are another modification of the first embodiment. The restriction structure 90 of the fourth embodiment is an annular ring member 94 in which the inner peripheral surface 94a is fitted to the outer peripheral surface 43b of the end portion 43c of the peripheral wall portion 43 on the body 70 side and the outer peripheral surface 70b of the body 70. It is. Further, the restricting structure 90 of the fifth embodiment is an annular ring member 95 in which the inner peripheral surface 95a is fitted to the outer peripheral surface 43b of the end portion 43c on the body 70 side in the peripheral wall portion 43. According to such ring members 94 and 95, deformation of the end portion 43c of the peripheral wall portion 43 toward the radially outer side can be reliably restricted. This makes it difficult for the seal portion 45 to be peeled off by the axial force P acting on the bottom wall portion 42 of the connector 40, and high sealing performance can be obtained.

(Sixth embodiment)
As shown in FIG. 9, the sixth embodiment of the present invention is still another modification of the first embodiment. The restricting structure 90 of the sixth embodiment has a protruding portion 96 protruding radially outward from the end portion 43c of the peripheral wall portion 43, and the end portion 43c side from the seal portion 45 at the interface between the outer peripheral surface 77a and the inner peripheral surface 43a. And an auxiliary seal portion 691 formed by laser welding. The protruding portion 96 and the auxiliary seal portion 691 are formed over the entire circumference of the end portion 43c. Moreover, the protrusion part 96 is exhibiting the flange shape. The end surface 96 a on the body 70 side of the protruding portion 96 and the end surface 43 d of the end portion 43 c are in contact with the contact surface 70 a of the body 70 that protrudes radially outward from the outer peripheral surface 77 a of the fitting portion 77.

  By forming the protruding portion 96, the circumferential wall portion 43 has improved radial rigidity. Therefore, the amount of deformation of the peripheral wall 43 end 43c outward in the radial direction can be reduced. Further, the projecting portion 96 can be supported toward the body 70 by the end surface 96a of the projecting portion 96 being in contact with the abutting surface 70a. In addition, the auxiliary seal portion 691 is formed on the end portion 43 c side with respect to the seal portion 45, and acts on the seal portion 45 by joining the inner peripheral surface 43 a of the peripheral wall portion 43 to the outer peripheral surface 77 a of the fitting portion 77. The axial force P in the axial direction can be dispersed. Furthermore, by moving the point of application of the stress due to the axial force P toward the distal end side of the end portion 43c, the force that deforms the end portion 43c of the peripheral wall portion 43 radially outward can be reduced. By exhibiting these functions, deformation of the peripheral wall 43 end portion 43c to the radially outer side is surely suppressed, and it is difficult to cause the seal portion 45 to be peeled off and high sealing performance can be obtained.

(Seventh embodiment)
As shown in FIG. 10, the seventh embodiment of the present invention is still another modification of the first embodiment. The restricting structure 90 according to the seventh embodiment includes a protruding portion 97 that protrudes radially inward from the end portion 43 c of the peripheral wall portion 43, and a joint portion 791 that joins the protruding portion 97 to the body 70. The protrusion 97 is formed over the entire periphery of the end 43c and has a flange shape. Here, the fitting portion 77 is formed with a contact surface 777b on which the protruding portion 97 contacts from the opposite side to the bottom wall portion 42, and the protruding portion 97 is locked to the contacting surface 777b. In addition, a joint 791 that joins the protrusion 97 to the contact surface 777b is formed by laser welding. The joint 791 is formed over the entire circumference of the end 43c.

  By forming the protruding portion 97, the circumferential wall portion 43 has improved radial rigidity. Therefore, the amount of deformation of the end portion 43c of the peripheral wall portion 43 outward in the radial direction can be reduced. Further, the protruding portion 97 is locked and joined to the body 70 by the joining portion 791, so that the end portion 43c of the peripheral wall portion 43 is reliably restricted from being deformed radially outward. By exhibiting these functions, even if the axial force P is applied to the bottom wall portion 42 of the connector 40, the seal portion 45 is hardly peeled off and high sealing performance can be obtained.

(Eighth embodiment)
As shown in FIG. 11, the eighth embodiment of the present invention is a modification of the seventh embodiment. The restricting structure 90 of the eighth embodiment has a convex portion 892 a provided in the protruding portion 98 and a concave portion 892 b provided in the fitting portion 77 instead of the joint portion 971. The convex portion 892a is fitted in the concave portion 892b along the axial direction. Moreover, the protrusion part 98, the convex part 892a, and the recessed part 892b are formed over the perimeter of the edge part 43c, and are exhibiting the annular | circular shape, respectively.
By exhibiting these functions, even if the axial force P is applied to the bottom wall portion 42 of the connector 40, the seal portion 45 is hardly peeled off and high sealing performance can be obtained.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, this invention is limited to the said embodiment and is not interpreted and can be applied to various embodiment in the range which does not deviate from the summary.

  In the first to eighth embodiments, the seal portion 45 is formed by laser welding. However, as long as strength and sealability can be obtained, the joining means is not limited, and welding other than laser welding or other means is possible. May be used. In addition, although the joint portions 91 and 791 in the first and seventh embodiments and the auxiliary seal portion 691 in the sixth embodiment are formed by laser welding, the joining means is not limited, and welding other than laser welding is performed. Alternatively, other means may be used.

  In the second, third, and eighth embodiments, the protrusions 92a, 93a, and 892a provided on one of the body 70 and the end 43c are merely fitted into the recesses 92b, 93b, and 892b provided on the other. However, the convex portions 92a, 93a, 892a and the concave portions 92b, 93b, 892b may be further joined by welding or the like. Moreover, you may join the end surface 43d of the surrounding wall part 43 of 4th-6th embodiment to the contact surface 70a of the body 70 by welding. Alternatively, in the second and third and sixth to eighth embodiments, a ring member may be externally fitted to the end 43c. Furthermore, in the first to fifth, seventh and eighth embodiments, an auxiliary seal portion may be formed closer to the end portion 43c than the seal portion 45 at the interface between the outer peripheral surface 77a and the inner peripheral surface 43a. .

  In the first to eighth embodiments, the restriction structure 90 is formed over the entire circumference of the end portion 43 c, but may be only a part of the circumferential wall portion 43 or the fitting portion 77 in the circumferential direction.

  In the first to eighth embodiments, the connector 40 has the valve housing portion 41 and is configured such that the fuel pressure in the pressurizing chamber 18 acts. However, like the high-pressure fuel pump 903 shown in FIG. 940 and the valve housing member 941 are formed separately, and the valve housing member 941 is fixed to the inner peripheral wall of the accommodating portion 75 by the fixing ring 941a, so that only the fuel pressure around the opening 75a acts on the connector 940. It may be configured to.

  In the first to eighth embodiments, an example in which the present invention is applied to the high-pressure fuel pump 3 that needs to seal against gasoline between the body 70 and the connector 40 that is a lid body thereof has been shown. The present invention can be applied to a high-pressure fuel pump that requires a seal against various types of fuel between the body and the lid.

1 is a configuration diagram of a fuel supply system including a high-pressure fuel pump according to a first embodiment of the present invention. 1 is a longitudinal sectional view of a high-pressure fuel pump according to a first embodiment of the present invention. It is sectional drawing which expands and shows the control structure of FIG. It is a schematic diagram for demonstrating a deformation | transformation of a surrounding wall part. It is sectional drawing which shows another modification of the control structure of FIG. It is sectional drawing which shows the modification of the control structure of FIG. It is sectional drawing which shows another modification of the control structure of FIG. It is sectional drawing which shows another modification of the control structure of FIG. It is sectional drawing which shows another modification of the control structure of FIG. It is sectional drawing which shows another modification of the control structure of FIG. It is sectional drawing which shows the modification of the control structure of FIG. It is a longitudinal cross-sectional view of the modification of the high pressure fuel pump of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel supply system, 2 Low pressure fuel pump, 3,903 High pressure fuel pump, 4 Delivery pipe, 5 Fuel injection valve, 6 Fuel tank, 7 Internal combustion engine, 11 Plunger, 12 Head, 13 Spring seat, 14 Tappet, 15 Spring, 16 Cam, 17 Oil seal, 18 Pressurization chamber, 20 Discharge valve, 21 Valve seat, 22 Valve body, 23 Stopper, 24 Spring, 40, 940 Connector (lid body), 41 Valve housing part, 41a Valve seat, 42 Bottom Wall portion, 43 peripheral wall portion, 43a inner peripheral surface, 43b outer peripheral surface, 43c end portion, 43d end surface, 44 connecting portion, 45 seal portion, 46 holding portion, 50 metering valve (solenoid valve), 941 valve housing member, 941a Fixing ring, 52 Valve member, 53 Valve closing spring, 54 Spring seat, 60 Electromagnetic drive unit, 62 Fixed core, 63 Movable core, 64 Drive rod, 65 Valve opening spring, 66 Coil part, 67 Wiring connector, 70 Body, 70a Contact surface, 70b Outer peripheral surface, 71 Cylinder, 72 Suction passage, 73 Discharge passage, 74 Relief Passage, 75 accommodating portion, 75a opening, 76 accommodating portion, 77 fitting portion, 77a outer peripheral surface, 777b abutting surface, 80 cover, 81 suction chamber, 90 regulating structure, 91,791 joint portion, 691 auxiliary seal portion, 92a, 93a, 892a Convex part, 92b, 93b, 892b Concave part, 94, 95 Ring member, 96, 97 Protruding part

Claims (15)

A high-pressure fuel pump that pressurizes low-pressure fuel and supplies it to the outside.
A body having an opening through which the fuel flows, and a fitting portion protruding in an annular shape from the periphery of the opening;
A lid body that is formed in a cylindrical shape and that forms a seal portion and covers the opening portion by fitting and joining the inner peripheral surface of the peripheral wall portion to the outer peripheral surface of the fitting portion;
A high-pressure fuel pump comprising: a restricting structure that restricts deformation of the end portion on the body side of the peripheral wall portion toward the radially outer side.   2. The high-pressure fuel pump according to claim 1, wherein the restriction structure includes a joint portion that joins the end portion to the body. The body forms an abutting surface with which an end surface on the body side of the end abuts,
The high-pressure fuel pump according to claim 2, wherein the joining portion joins the end surface to the contact surface.   The high-pressure fuel pump according to claim 2 or 3, wherein the joint portion is formed over the entire circumference of the end portion.   The said restriction | limiting structure has an auxiliary | assistant seal part which joins the inner peripheral surface of the said surrounding wall part with the outer peripheral surface of the said fitting part on the said edge part side rather than the said seal part. A high-pressure fuel pump according to claim 1.   The restriction structure includes a convex portion provided on one of the end portion and the body, and a concave portion provided on the other of the end portion and the body and into which the convex portion is fitted. The high-pressure fuel pump according to any one of 1 to 5.   The high-pressure fuel pump according to claim 6, wherein the convex portion and the concave portion are formed over the entire circumference of the fitting portion and the end portion.   The high-pressure fuel pump according to any one of claims 1 to 7, wherein the regulation structure includes a ring member having an inner peripheral surface fitted to an outer peripheral surface of the end portion.   The high-pressure fuel pump according to any one of claims 1 to 8, wherein the restriction structure has a protruding portion that protrudes in a radial direction from the end portion. The protruding portion protrudes radially outward from the end portion,
The high-pressure fuel pump according to claim 9, wherein an end surface of the protruding portion on the body side is supported by the body.   The high-pressure fuel pump according to claim 9 or 10, wherein the protruding portion protrudes radially inward from the end portion and is locked by the body.   The high-pressure fuel pump according to any one of claims 9 to 11, wherein the protruding portion is formed over the entire circumference of the end portion.   The high-pressure fuel pump according to any one of claims 1 to 12, wherein the body and the lid jointly form a pressurizing chamber that pressurizes the fuel downstream of the opening. An electromagnetic valve having a valve member for controlling the fuel supply amount;
The high-pressure fuel pump according to any one of claims 1 to 13, wherein the valve member is inserted into the opening. The solenoid valve is held by a lid made of a magnetic material, and has a coil portion that drives the valve member by forming a magnetic circuit in the lid by energization.
The high pressure according to claim 14, wherein the seal portion is formed by welding the inner peripheral surface of the peripheral wall portion and the outer peripheral surface of the fitting portion, and is located on the body side with respect to the coil portion. Fuel pump.

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