JP5178676B2 - High pressure fuel supply pump - Google Patents

Description

  The present invention relates to a high-pressure fuel supply pump for an internal combustion engine, and more particularly to the structure of a joint for attaching an accessory to a pump housing.

  In the high pressure fuel pump described in Japanese Patent Application Laid-Open No. 2005-279778, for example, in order to weld and fix the fuel pipe connection joint to the side of the pump housing, a stepped portion protruding from the pump housing is provided, and the joint weld joint surface is provided. It is provided at a position that protrudes further from the outermost shape of the pump housing.

JP 2005-279778 A

  In the above prior art, since the welded joint is in the stepped portion protruding from the side surface of the pump housing, the outline of the high-pressure fuel supply pump including the joint is increased by the size of the protruding stepped portion.

  An object of the present invention is to provide a small-sized and low-cost high-pressure fuel supply pump.

  In the high-pressure fuel supply pump according to the present invention to achieve the above-mentioned target, a plane portion processed on the side surface of the pump housing is provided, and a passage communicating with the fluid chamber inside the pump housing is opened in the plane portion. An annular surface for joining parts is provided around the opening of the passage, and a recess formed by a recess or a groove is provided around the annular face for joining the parts.

  Preferably, the depth of the recess or groove is 1 to 2 mm.

  As a result, an annular flat surface portion is formed on the side surface of the pump housing, a fuel passage is opened at the center of the flat surface portion, and a cylinder having a height of 1 to 2 mm having an annular surface for joining formed at the tip. Part.

  Preferably, the joint surface provided at the tip of the component has an annular joint surface having the same diameter as the outer diameter of the cylindrical portion provided in the pump housing.

  In the present invention configured as described above, it is not necessary to provide a joining protrusion that protrudes from the outline of the pump housing, so that wasteful meat of the pump housing can be reduced.

1 is an example of a fuel supply system using a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. 1 is a longitudinal sectional view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. It is a longitudinal cross-sectional view of another angle of the high-pressure fuel supply pump by the 1st Example by which this invention was implemented, and represents the longitudinal cross-section of the position which shifted | deviated 90 degrees in the circumferential direction with FIG. It is an enlarged view of the electromagnetic suction valve mechanism of the high-pressure fuel supply pump according to the first embodiment in which the present invention is implemented, and shows a state where the electromagnetic coil is not energized. It is an enlarged view of the electromagnetic suction valve mechanism of the high-pressure fuel supply pump by the 1st example by which the present invention was implemented, and shows the state where electricity was supplied to the electromagnetic coil. 1 is a cross-sectional view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. It is a cross-sectional view of a high-pressure fuel supply pump according to a second embodiment in which the present invention is implemented. It is a bird's-eye view of the high-pressure fuel supply pump by the 2nd example with which the present invention was implemented. It is a cross-sectional view of a high-pressure fuel supply pump according to a third embodiment in which the present invention is implemented.

  Hereinafter, an embodiment will be described in more detail with reference to the drawings.

  An embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, a portion surrounded by a broken line indicates a pump housing 1 of the high-pressure pump, and mechanisms and components shown in the broken line indicate that they are integrated into the pump housing 1 of the high-pressure pump. .

  The fuel in the fuel tank 20 is pumped up by the feed pump 21 based on a signal from an engine control unit 27 (hereinafter referred to as ECU), pressurized to an appropriate feed pressure, and passed through the suction pipe 28 to the suction port 10a of the high-pressure fuel supply pump. Sent to.

  The fuel that has passed through the suction port 10a passes through a filter 102 fixed in the suction joint 101, and further, an electromagnetically driven valve mechanism 30 that constitutes a variable capacity mechanism via the suction flow path 10b and the metal diaphragm dampers 9 and 10c. To the intake port 30a.

  The suction filter 102 in the suction joint 101 serves to prevent foreign matter existing between the fuel tank 20 and the suction port 10a from being absorbed into the high-pressure fuel supply pump by the flow of fuel.

  FIG. 4 is an enlarged view of the electromagnetic intake valve mechanism 30 and shows a state where the electromagnetic coil 53 is not energized and is not energized.

  FIG. 5 is an enlarged view of the electromagnetic intake valve mechanism 30, and shows a state where the electromagnetic coil 53 is energized.

  The pump housing 1 is formed with a convex portion 1A as a pressurizing chamber 11 at the center, and a hole 30A for mounting the electromagnetic suction valve mechanism 30 is formed so that the pressurizing chamber 11 opens.

  The plunger rod 31 constituting the movable plunger is composed of three parts, that is, a suction valve portion 31a, a rod portion 31b, and an anchor fixing portion 31c, and the anchor 35 is welded and fixed to the anchor fixing portion 31c by a welding portion 37b.

  As shown in the figure, the spring 34 is fitted into the anchor inner periphery 35a and the first core portion inner periphery 33a, and a spring force is generated by the spring 34 in a direction in which the anchor 35 and the first core portion 33 are separated.

  When the electromagnetic coil 53 is not energized and is not energized, and when there is no fluid differential pressure between the suction channel 10c (suction port 30a) and the pressurizing chamber 11, the plunger rod 31 is As shown in FIG. 4, it moves to the right in the figure. In this state, the intake valve portion 31a and the intake valve seat portion 32a come into contact with each other and the intake port 38 is closed.

  When the piston plunger 2 is in the suction process state in which the piston plunger 2 is displaced downward in FIG. 2 due to the rotation of the cam described later, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. In this process, when the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction passage 10c (suction port 30a), the suction valve portion 31a is provided with a valve opening force (suction valve portion 31a) due to the fluid differential pressure of the fuel. 1) is generated.

  By the valve opening force due to the fluid differential pressure, the suction valve portion 31a is set to open over the biasing force of the spring 34 and open the suction port 38.

  In this state, when a control signal from the ECU 27 is applied to the electromagnetic intake valve mechanism 30, an electric current flows through the electromagnetic coil 53 of the electromagnetic intake valve mechanism 30, and between the first core portion 33 and the anchor 35, Magnetic biasing forces that attract each other are generated. As a result, a magnetic biasing force is applied to the plunger rod 31 to the left in the drawing.

  As a result, the state in which the suction valve portion 31a opens the suction port 38 is maintained, and the fuel flows from the suction port 30a through the suction passage portion 32b of the valve seat member 32 and the suction port 38 into the pressurizing chamber 11.

  When the piston plunger 2 finishes the suction process while the application state of the input voltage is maintained in the electromagnetic suction valve mechanism 30, and moves to the compression process in which the piston plunger 2 is displaced upward in FIG. 2, the magnetic biasing force is maintained. As a result, the intake valve portion 31a is still open.

  The volume of the pressurizing chamber 11 decreases with the compression movement of the piston plunger 2, but in this state, the fuel once sucked into the pressurizing chamber 11 once again passes through the suction port 38 in the valve-opened state, and the suction flow path 10c ( Since the pressure is returned to the suction port 30a), the pressure in the pressurizing chamber does not increase. This process is called a return process.

  In this state, when the control signal from the ECU 27 is canceled and the electromagnetic coil 53 is de-energized, the magnetic biasing force acting on the plunger rod 31 is after a certain time (after magnetic and mechanical delay time). Erased. Since the urging force of the spring 34 is acting on the suction valve portion 31 a, the suction valve portion 31 a closes the suction port 38 with the urging force of the spring 34 when the electromagnetic force acting on the plunger rod 31 disappears. When the suction port 38 is closed, the fuel pressure in the pressurizing chamber 11 increases with the upward movement of the piston plunger 2 from this time. When the pressure in the fuel discharge port 12 or higher is reached, high pressure discharge of the fuel remaining in the pressurizing chamber 11 is performed via the discharge valve unit 8 and supplied to the common rail 23. This process is called a discharge process. That is, the compression process of the piston plunger 2 (the ascending process from the lower start point to the upper start point) includes a return process and a discharge process.

  And the quantity of the high-pressure fuel discharged can be controlled by controlling the timing which cancels | releases the electricity supply to the electromagnetic coil 53 of the electromagnetic suction valve mechanism 30. FIG.

  If the timing of releasing the energization of the electromagnetic coil 53 is advanced, during the compression process, the ratio of the return process is small and the ratio of the discharge process is large.

  That is, the amount of fuel returned to the suction channel 10c (suction port 30a) is small, and the amount of fuel discharged at high pressure is large.

  On the other hand, if the timing for releasing the input voltage is delayed, the ratio of the return process in the compression process is large and the ratio of the discharge process is small. That is, the amount of fuel returned to the suction passage 10c is large, and the amount of fuel discharged at high pressure is small. The timing for releasing the energization of the electromagnetic coil 53 is controlled by a command from the ECU.

  With the configuration as described above, the amount of fuel discharged at high pressure can be controlled to the amount required by the internal combustion engine by controlling the timing of releasing the energization of the electromagnetic coil 53.

  Thus, the fuel guided to the fuel inlet 10a is pressurized to a high pressure by the reciprocating motion of the piston plunger 2 in the pressurizing chamber 11 of the pump housing 1, and is pumped from the fuel outlet 12 to the common rail 23. .

  An injector 24 and a pressure sensor 26 are attached to the common rail 23. The injectors 24 are mounted in accordance with the number of cylinders of the internal combustion engine, open and close according to a control signal from an engine control unit (ECU) 27, and inject fuel into the cylinders.

  A convex portion 1A as a pressurizing chamber 11 is formed at the center of the pump housing 1, and a recess 11A for mounting the discharge valve unit 8 is formed through the peripheral wall of the pressurizing chamber 11.

  A discharge valve unit 8 is provided at the outlet of the pressurizing chamber 11. The discharge valve unit 8 includes a sheet member (valve seat) 8a, a discharge valve 8b, a discharge valve spring 8c, and a holding member 8d as a discharge valve stopper. The discharge valve unit 8 is welded to the outside of the pump housing 1 by welding a weld 8e. Assemble unit 8. Thereafter, the discharge valve unit 8 assembled from the left side in the figure is press-fitted and fixed to the pump housing 1. The press-fitting unit also has a function of blocking the pressurizing chamber 11 and the discharge port 12.

  In a state where there is no fuel differential pressure between the pressurizing chamber 11 and the discharge port 12, the discharge valve 8b is pressed against the seat member 8a by the urging force of the discharge valve spring 8c and is in a closed state. Only when the fuel pressure in the pressurizing chamber 11 becomes larger than the fuel pressure in the discharge port 12 by a predetermined value, the discharge valve 8b is opened against the discharge valve spring 8c, and the pressure in the pressurizing chamber 11 is increased. The fuel is discharged to the common rail 23 through the discharge port 12.

  The outer periphery of the cylinder 6 is held by a cylindrical fitting portion 7 a of the cylinder holder 7. The cylinder 6 is fixed to the pump housing 1 by screwing a screw 7 g threaded on the outer periphery of the cylinder holder 7 into a screw 1 b threaded on the pump housing 1.

  The plunger seal 13 is held at the lower end of the cylinder holder 7 by the seal holder 15 and the cylinder holder 7 that are press-fitted and fixed to the inner cylindrical surface portion 7 c of the cylinder holder 7. At this time, the plunger seal 13 is held by the inner cylindrical surface portion 7c of the cylinder holder 7 coaxially with the shaft of the cylindrical fitting portion 7a. The piston plunger 2 and the plunger seal 13 are installed in a slidable contact state at the lower end of the cylinder 6 in the figure.

  This prevents the fuel in the seal chamber 10f from flowing into the tappet 3 side, that is, the inside of the engine. At the same time, lubricating oil (including engine oil) for lubricating the sliding portion in the engine room is prevented from flowing into the pump housing 1.

  The cylinder holder 7 is provided with an outer cylindrical surface portion 7b, in which a groove 7d for fitting the O-ring 61 is provided. The O-ring 61 shuts off the engine cam side and the outside by the inner wall of the engine-side fitting hole 70 and the groove 7d of the cylinder holder 7 and prevents engine oil from leaking outside.

  The cylinder 6 has a crimping portion 6 a that intersects the reciprocating direction of the piston plunger 2, and the crimping portion 6 a is crimped to the crimping surface 1 a of the pump housing 1. Crimping is performed by thrust generated by screw tightening. The pressurizing chamber 11 is formed by this pressure bonding, so that even if the fuel in the pressure chamber 11 is pressurized and becomes high pressure, the screw is not leaked from the pressure chamber 11 through the pressure bonding portion. Tightening torque must be managed.

  Further, in order to keep the sliding length of the piston plunger 2 and the cylinder 6 properly, the structure is such that the cylinder 6 is inserted deeply into the pressurizing chamber 11. A clearance 1 </ b> B is provided between the outer periphery of the cylinder 6 and the inner periphery of the pump housing 1 on the pressure chamber 11 side from the crimping portion 6 a of the cylinder 6. Since the outer periphery of the cylinder 6 is held by the cylindrical fitting portion 7a of the cylinder holder 7, the clearance 1B is provided so that the outer periphery of the cylinder 6 and the inner periphery of the pump housing 1 do not come into contact with each other. it can.

  As described above, the cylinder 6 holds the piston plunger 2 that moves forward and backward in the pressurizing chamber 11 so as to be slidable along the forward and backward movement direction.

  At the lower end of the piston plunger 2 is provided a tappet 3 that converts the rotational motion of the cam 5 attached to the camshaft of the engine into vertical motion and transmits it to the piston plunger 2. The piston plunger 2 is pressed against the tappet 3 by a spring 4 via a retainer 15. The retainer 15 is fixed to the piston plunger 2 by press-fitting. Thereby, the piston plunger 2 can be moved up and down (reciprocating) in accordance with the rotational movement of the cam 5.

  Here, the suction channel 10c is connected to the seal chamber 10f via the suction channel 10d and the suction channel 10e provided in the cylinder holder 7, and the seal chamber 10f is always connected to the pressure of the intake fuel. ing. When the fuel in the pressurizing chamber 11 is pressurized to a high pressure, a small amount of high-pressure fuel flows into the seal chamber 10f through the sliding clearance between the cylinder 6 and the piston plunger 2, but the inflowed high-pressure fuel is released to the suction pressure. Therefore, the plunger seal 13 is not damaged by the high pressure.

  The piston plunger 2 includes a large-diameter portion 2 a that slides with the cylinder 6 and a small-diameter portion 2 b that slides with the plunger seal 13. The diameter of the large diameter portion 2a is set larger than the diameter of the small diameter portion 2b, and is set coaxially with each other. The sliding part with the cylinder 6 is the large diameter part 2a, and the sliding part with the plunger seal 13 is the small diameter part 2b. Thereby, since the joint part of the large diameter part 2a and the small diameter part 2b exists in the seal chamber 10f, the volume of the seal chamber 10f changes with the sliding movement of the piston plunger 2, and the fuel is It moves between the seal chamber 10f and the suction channel 10c through the suction channel 10d and the suction channel 10s.

  The metal diaphragm damper 9 is composed of two metal diaphragms, and the outer periphery is fixed to each other by welding all around the welded portion in a state where gas is sealed in the space between both diaphragms. When low pressure pressure pulsation is loaded on both surfaces of the metal diaphragm damper 9, the metal diaphragm damper 9 changes its volume, thereby reducing the low pressure pulsation.

  The high-pressure fuel supply pump is fixed to the engine by a flange 41, a set screw 42, and a bush 43. The flange 41 is welded to the pump housing 1 by welding at a welded portion 41a. In this embodiment, laser welding is used.

  6 is a cross-sectional view of the high-pressure fuel pump shown in FIG.

  Planar portions 90f and 90g processed on the side surface of the pump housing 1 are provided, and passages communicating with the fluid chambers 92 and 93 inside the pump housing 1 are opened in the flat portions 90f and 90g. Annular surfaces 90b, 90e for component joining are provided around the periphery, and recesses formed by recesses 90h, 90h2 or grooves 90c are provided around the annular surfaces 90b, 90e for component joining.

  Specifically, cylindrical portions (convex portions) 90d1 and 90d2 having heights u2 and u3 from the bottom surface of the recess 90h or the groove 90c are formed around the opening of the passage.

  A cylindrical portion 90a having a smaller diameter is formed at the tip of the cylindrical portion (convex portion) 90d1. The cylindrical portions (convex portions) 90d1 and 90d2 are provided with joint portions 91 as parts and flat portions 90b and 90e to which the first core portion 33 flat of the electromagnetic drive mechanism is welded. In the embodiment of FIG. 1, annular recesses 90h and 90h2 are formed in two steps around the cylindrical portion (convex portion) 90d1.

  A fluid passage communicating with a fluid chamber 92 formed inside the pump housing 1 is formed at the center of the cylindrical portion (convex portion) 90d1.

  A cylindrical portion 91b having an outer diameter that is the same as the outer diameter of the cylindrical portion (convex portion) 90d1 is formed at the end of the high pressure piping joint 91 on the pump housing 1 side. Yes. The end surface of the joint 91 is abutted against the annular surface 90b for joining parts of the cylindrical part (convex part) 90d1 of the pump housing 1, and the entire outer periphery of the joint part is welded by laser irradiation.

  Thus, the fluid chamber 92 is covered by the joint 91 and the joint is sealed by the weld.

  A hole communicating with the fluid chamber 93 formed inside the pump housing 1 is formed in the center of the cylindrical portion (convex portion) 90d2.

  A part of the outer periphery of the electromagnetic drive mechanism is inserted into this hole, and the first core portion 33 and the flat portion 90e of the cylindrical portion (convex portion) 90d2 of the pump housing 1 are joined to close the fluid chamber 93, The fluid is sealed by welding the entire circumference of the joint surface.

  In order to increase the height of the cylindrical portions (convex portions) 90d1, 2 of the pump housing 1, there are two methods of digging inside the pump housing 1 or projecting it outward. The pump housing 1 is often provided with a structure for obtaining pump performance up to the limit of the outer wall surface, and it is difficult to dig deep inside. For this reason, it is necessary to increase the size of the outer periphery of the pump housing 1, which increases material costs and processing costs.

  Therefore, the heights u2 and u3 of the cylindrical portions (convex portions) 90d1 and 90d2 of the pump housing 1, that is, the depths of the grooves 90c and the recesses 90h are set to 1 to 2 mm or less from the flat portions 90b and 90e of the pump housing 1. The welding plane can be secured without deeply shaving the pump housing 1.

  The cylindrical portions (convex portions) 90d1 and 2 of the pump housing 1 and the corner portions 201 and 202 of the concave portion formed by the recess 90h or the groove 90c are connected by a curve of R0.2 to R1.0. This is matched with the cutting edge R of the cutting tool used when cutting. When using a butt joint for welding, it is desirable that the welds be parallel surfaces. If a parallel surface is not obtained and connected by a curved portion, the weld surface becomes uneven and the joining length changes. As a result, when welding is performed with the welding power set in advance in the welding machine, the designed joint length cannot be obtained.

  The reason why the heights of the cylindrical portions (convex portions) 90d1 and 90d1 are set to 1 to 2 mm will be described.

  When the corners 201 and 202 are R0.2, the parallel part can be secured by 1.8 mm, and even when the corners 201 and 202 are R1, the parallel part can be secured by 1 mm. On the other hand, the minimum length of the parallel portion required for laser welding is 0.5 mm on one side. That is, it is the distance which can ensure the minimum plane part of a welding part, considering the cutting edge R of a blade. Further, by setting R of corner portions 201 and 202 to 0.2 or more, a structure that is not a notch shape can be obtained, and the strength can be increased.

  Since the valve seat 32 is press-fitted and fixed to the pump housing 1 in a state where the valve seat 32 and the first core portion 33 are press-fitted and fixed, the relative position between the pump housing 1 and the first core portion 33 can be determined. Welding can be performed without holding the pump housing 1 and the first core portion 33.

  It is desirable that the flat surfaces 90b and 90e of the cylindrical portions 90d1 and 90d2 of the pump housing 1 and the abutting surfaces of the joining members 33 and 91 having the cylindrical portions are perpendicular to the central axis of the lateral hole forming the fluid chambers 92 and 93. . Further, it is desirable that the flat portion 90b as a butting surface between the pump housing 1 and the fuel joint 91 has no gap. The center axis of the pump housing 1 fluid chambers 92 and 93 and the center axis of the joining members 33 and 91 having cylindrical portions are preferably coaxial.

  This further improves the welding accuracy and assembly accuracy. As a result, the positional accuracy with respect to the mounting portion on the engine side, for example, the fuel pipe or the control signal input connector is improved.

  The joining members 33 and 91 having cylindrical portions are likely to be coaxial when the press-fitting portion with the pump housing 1 and the cylindrical outer diameter portion to be welded are processed with the same member.

  The flat portions 90b and 90e formed in the cylindrical portions 90d1 and 90d2 of the pump housing 1 are formed at a position of 1 to 2 mm from the bottom surface of the recess formed by the recess 90h or the groove 90c. The entire circumference can be welded by laser irradiation from the side.

  The basic configuration of the present invention configured as described above corresponds to the claims as follows.

  A flat surface portion (90f, 90g) processed on the side surface of the pump housing (1) is provided, and a fuel passage (92, 93) is formed in the center of the flat surface portion (90b, 90e) toward the inside of the pump housing (1). An annular surface (90b, 90e) for joining parts is provided around the opening of the fuel passage (92, 93), and a recess or groove is formed around the annular face (90b, 90e) for joining parts. Recesses (90h, 90h2, 90c) were formed. Preferably, the depth of the recesses (90h, 90h2, 90c) formed by the depressions or grooves is 1 to 2 mm. As a result, it has a processing flat surface portion (90b, 90e) formed on the side surface of the pump housing (1), has a fuel passage (92, 93) opening at its center, and a ring for joining parts at its tip. The above-mentioned goal is achieved by installing cylindrical portions (90b, 90d) having a height of 1-2 mm and having surfaces (90b, 90d). Preferably, the joint portion (90a) provided at the tip of the joint (91) as a part has an annular joint surface having the same diameter as the outer diameter of the cylindrical portions (90b, 90d).

  FIG. 7 is a second embodiment of the cross-sectional view of the high-pressure fuel pump shown in FIG.

  The side surface of the pump housing 1 has a flat portion 90b and is provided with an annular recess 90c. A hole is provided in the flat surface portion 90 b inside the annular recess 90 c, and the inner diameter portion of this hole is used as a fluid chamber 92. The fuel joining joint 91 having the same outer diameter as the inner wall surface of the annular recess 90c and the inner wall surface of the pump housing 1 annular recess 90c are joined to close the fluid chamber 92, and the fluid is obtained by welding. It is sealed.

  By setting the depth u2 of the annular recess 90c provided in the pump housing 1 to 1 to 2 mm or less from the flat portion 90b of the pump housing 1, a welding plane can be secured without deeply shaving the pump housing 1. By forming this welding plane, welding by a butt joint can be performed.

  A fuel joint having a convex portion 90a provided between the inner diameter of a hole (fluid chamber) 92 provided in the flat surface portion 90b of the pump housing 1 and the inner wall surface of the annular concave portion 90c, and having an inner diameter equal to the outer diameter of the convex portion 90a. The fuel joining joint 91 can also be fixed by press-fitting 91 into the convex portion 90a. As a result, welding can be performed without holding the pump housing 1 and the fuel joint 91 when welding is performed.

  By press-fitting and fixing the inner wall surface of the fuel joint joint 91 to the convex portion 90a of the pump housing 1, the fuel joint joint 91 will not move even if vibration is applied during the assembly operation or the pump housing 1 is tilted. Further, since the pump housing 1 and the fuel joint 91 are held coaxially and welding can be performed without shifting the relative position, the assembly accuracy can be improved.

  By fixing the inner wall surface of the joining member 91 having the cylindrical portion to the pump housing 1 convex portion 90a, the joining member 91 having the cylindrical portion is fixed while securing the space of the pump housing 1 fluid chamber 92. And the strength can be further increased.

  FIG. 8 is a bird's-eye view of the high-pressure fuel pump shown in FIG.

  According to the prior art, the lower surface portion of the pump housing 1 has a vertically cut shape like the high-pressure fuel pump shown in FIG. However, such a shape has a problem that a lot of burrs are generated after processing, and it takes time for finishing work. Therefore, a structure is provided in which a taper 94 is provided on the side surface of the pump housing 1. Thereby, the quantity of the burr | flash which generate | occur | produces at the time of the process of the pump housing 1 can be reduced, and the time of finishing work can be shortened. Since the volume is reduced by cutting the pump housing 1, the weight can be reduced. In addition, the body housing 1 is streamlined by the taper 94 so that heat from the engine is not retained. As a result, the amount of heat accumulated in the pump housing 1 is reduced, so that changes in performance due to temperature rise of the internal fluid and thermal deformation of internal components are reduced. By providing the taper 94 on the side surface of the pump housing 1, it is difficult to interfere with the installation tool when the high-pressure fuel pump is installed, and the work at the time of installation of the pump is facilitated. Moreover, even if the taper is divided into a plurality of stages, the burr reduction effect is improved.

  FIG. 9 is a third embodiment of the cross-sectional view of the high pressure fuel pump shown in FIG.

  As shown in the figure, the pump housing 1 can be applied in various shapes such as a perfect circle, an ellipse, a square, and a hexagon.

  According to the above embodiments, the following problems can be solved.

  In the prior art, since the welded joint is in the stepped portion protruding from the side surface of the pump housing, the outline of the high-pressure fuel supply pump including the joint is increased by the size of the protruding stepped portion.

  In addition, in the conventional technology in which the welded joint is at the stepped portion protruding from the side surface of the pump housing, the assembly accuracy is likely to deteriorate, and an excessive stress is applied to the connection pipe due to the displacement of the joint between the joint and the protruding stepped portion. May occur and break.

  Further, diffuse reflection occurs only when the focal position of laser irradiation is slightly deviated from the joint, and welding is not performed completely. For this reason, assembly position tolerance and positioning accuracy between the joint and the protruding stepped portion are strictly required, and high accuracy is required to control the position of beam irradiation in laser welding.

  According to this embodiment, positioning of the joint between the accessory such as the joint and the control valve mechanism and the pump housing is facilitated, and the accuracy thereof is improved. As a result, a small-sized and low-cost high-pressure fuel supply pump is achieved. Can provide.

  The present invention can be applied not only to a high-pressure fuel supply pump of a gasoline engine but also to a high-pressure fuel supply pump of a diesel engine.

DESCRIPTION OF SYMBOLS 1 Pump housing 2 Piston plunger 5 Cam 6 Cylinder 7 Cylinder holder 7a Cylindrical fitting part 7b Outer cylindrical surface part 7c Inner cylindrical surface part 8 Discharge valve unit 9 Metal diaphragm damper 11 Pressurization chamber 12 Discharge port 13 Plunger seals 61, 62 O-ring 90b, 90e Plane portion 90c Groove (concave portion)
90d1, 90d2 Cylindrical part 90h, 90h2 hollow (recessed part)
90f, 90g Welded joint 91 Fuel coupling joint 92, 93 Fuel passage (fluid chamber)
100 engine block

Claims (9)

A pump housing, a cylinder combined with the pump housing, a plunger supported by the cylinder so as to be reciprocally movable, and a plunger for pressurizing fluid in a pressurizing chamber formed between the cylinder and the pump housing. In what pressurizes the fuel sucked into the pressurizing chamber by reciprocation and discharges it from the pressurizing chamber,
A flat portion machined on the side surface of the pump housing is provided, a passage communicating with the fluid chamber inside the pump housing is opened in the flat portion, and an annular surface for joining parts is provided around the opening portion of the passage. A high-pressure fuel supply pump provided with a recess formed by a recess or a groove around the annular surface for joining the components. In claim 1,
A high-pressure fuel supply pump, wherein the depth of the recess or groove is 1 to 2 mm. A pump housing, a cylinder combined with the pump housing, a plunger supported by the cylinder so as to be reciprocally movable, and a plunger for pressurizing fluid in a pressurizing chamber formed between the cylinder and the pump housing. In what pressurizes the fuel sucked into the pressurizing chamber by reciprocation and discharges it from the pressurizing chamber,
The flat portion of the annular machined formed on the side surface of the pump housing, the cylindrical portion of the height 1~2mm the flat portion is formed, it is opened fuel passages in the center of its, for bonding to said flat portion A high-pressure fuel supply pump in which an annular surface is formed. In claim 3 ,
A high-pressure fuel supply pump in which an annular joint surface having the same diameter as an outer diameter of a cylindrical portion provided in a pump housing is formed on a joint surface provided at a tip of a part to be joined. A pump housing, a cylinder combined with the pump housing, a plunger supported by the cylinder so as to be reciprocally movable, and a plunger for pressurizing fluid in a pressurizing chamber formed between the cylinder and the pump housing. In what pressurizes the fuel sucked into the pressurizing chamber by reciprocation and discharges it from the pressurizing chamber,
A flat portion is provided on the side surface of the pump housing, a fuel passage perpendicular to the flat portion is provided, a cylindrical portion is formed on the outer periphery of the fuel passage, and the same diameter of the joining member having a cylindrical portion having the same diameter as the cylindrical portion A high-pressure fuel supply pump characterized in that a part is welded to the cylindrical part. The thing of Claim 5 WHEREIN:
The cylindrical portion on the outer periphery of the fuel passage is a high pressure fuel supply pump formed by providing an annular recess in the flat portion. The thing of Claim 5 WHEREIN:
The cylindrical portion on the outer periphery of the fuel passage is a high pressure fuel supply pump formed by providing an annular convex portion on the flat portion. In any one of claims 5 to 7,
The cylindrical portion on the outer periphery of the fuel passage is a high-pressure fuel supply pump in which the height of the cylindrical portion is 1 to 2 mm. In any one of claims 5 to 8,
At least one of the fuel passages is a high pressure fuel supply pump having a check valve.

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