JP6430354B2 - High pressure fuel supply pump - Google Patents

Description

  The present invention relates to a high-pressure fuel supply pump that pumps fuel to a fuel injection valve of an internal combustion engine, and particularly includes a pump body in which a pressurizing chamber that pressurizes fuel is formed, and functional parts such as an electromagnetic suction valve mechanism are provided in the pump body. It relates to the structure to be attached.

  There exists a thing of patent document 1 as a prior art of the high-pressure fuel pump of this invention. According to Patent Document 1, “the outer wall surface of the cover has a multi-sided cross section perpendicular to the axis of the plunger. Therefore, the outer wall of the cover has at least three or more planes. Therefore, one end of the fuel inlet. Since the fitting hole for fitting the first through hole and the second through hole can be provided on a plane different from the plane in which the first through hole and the second through hole are opened, the fuel inlet and the cover can be easily joined. In particular, when the fuel inlet and the cover are joined by welding or brazing, productivity is improved "(see paragraph 0015).

JP 2012-215164 A

  In FIG. 3 of the above-mentioned Patent Document 1, the fuel inlet and the cover are joined, but when this joined part is welded to the cover or the pump body, the stress due to the welding is concentrated on the welded part, so that the welded part is welded. There is a risk of cracks. If it does so, since there exists a possibility of causing a fuel leak from a crack location and causing the failure | damage of joining components, it is necessary to suppress this stress concentration.

  Therefore, an object of the present invention is to provide a high-pressure fuel pump that suppresses stress concentration at a welded portion of a welded part and improves reliability.

In order to achieve the above object, the high-pressure fuel supply pump of the present invention comprises:
"A function part which is inserted into the hole formed in the pump body, the first contact portion of the inner peripheral portion of the hole and the outer peripheral portion of the functional component on the outer peripheral surface is fixed by welding, welding A space is formed on the opposite side of the outer peripheral surface with respect to the formed part, and the outer peripheral portion of the functional component formed in the insertion direction of the functional component and the inner peripheral portion of the hole portion are in contact with each other. site the contact portion is the welded and provided separately from, Rukoto be located towards the center side from the outer peripheral surface of the pump body, the welded portion, the space in the order of the second contact portion ".

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the high pressure fuel pump which suppressed the stress concentration of the welding part of a welding component, and aimed at the improvement of reliability.

  Other configurations, operations, and effects of the present invention will be described in detail in the following examples.

1 is a longitudinal sectional view of a high-pressure fuel supply pump according to a first embodiment of the present invention. It is the horizontal direction sectional view seen from the upper direction of the high-pressure fuel supply pump by the first example of the present invention. It is the longitudinal cross-sectional view seen from FIG. 1 of the high-pressure fuel supply pump by 1st Example of this invention from another direction. 1 is a longitudinal sectional view of a high-pressure fuel supply pump in which a suction joint according to a first embodiment of the present invention is attached to a side surface of a pump body. 1 shows a welding structure of a discharge joint of a high-pressure fuel supply pump according to a first embodiment of the present invention. 1 is an enlarged longitudinal sectional view of an electromagnetic intake valve mechanism of a high-pressure fuel supply pump according to a first embodiment of the present invention, showing a state where the electromagnetic intake valve is in an open state. 1 shows a configuration diagram of an engine system to which a high-pressure fuel supply pump according to a first embodiment of the present invention is applied. FIG. 1 is a horizontal sectional view of a high-pressure fuel supply pump in which a suction joint according to a first embodiment of the present invention is attached to a side surface of a pump body, as viewed from above.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, a first embodiment of the present invention will be described in detail with reference to the drawings.

The configuration and operation of the system will be described with reference to the overall configuration diagram of the engine system shown in FIG.
A portion surrounded by a broken line indicates a main body of a high-pressure fuel supply pump (hereinafter referred to as a high-pressure pump), and indicates that the mechanism / part shown in the broken line is integrated in the pump body 1. .

  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). The fuel is pressurized to an appropriate feed pressure and sent to the low-pressure fuel inlet 10a of the high-pressure pump through the suction pipe 28. The fuel that has passed through the suction joint 51 from the low-pressure fuel suction port 10a is a pressure pulsation propagation preventing mechanism 100 having a valve 102, a pressure pulsation reducing mechanism 9, and a suction port 31b of an electromagnetic suction valve 300 that constitutes a variable capacity mechanism via a suction passage. To.

  The fuel that has flowed into the electromagnetic suction valve 300 passes through the fuel introduction passage 30p and the valve body 30 and flows into the pressurizing chamber 11. The reciprocating power is applied to the plunger 2 by the cam mechanism 93 of the engine. The reciprocating motion of the plunger 2 sucks fuel from the valve body 30 during the downward stroke of the plunger 2 and pressurizes the fuel during the upward stroke. Through the discharge valve mechanism 8, the fuel is pumped to the common rail 23 to which the pressure sensor 26 is attached. The injector 24 injects fuel into the engine based on a signal from the ECU 27. This embodiment is a high pressure pump applied to a so-called direct injection engine system in which an injector 24 blows fuel directly into a cylinder cylinder of an engine.

  The high pressure pump discharges the fuel flow rate so as to obtain a desired supply fuel by a signal from the ECU 27 to the electromagnetic suction valve 300.

  FIG. 1 is a longitudinal sectional view of the high-pressure pump of this embodiment, and FIG. 2 is a horizontal sectional view of the high-pressure pump as viewed from above. FIG. 3 is a longitudinal sectional view of the high-pressure pump as seen from a different direction from FIG. In FIG. 1, the suction joint 51 is provided at the upper portion of the damper cover, but FIG. 4 is a longitudinal sectional view of the high-pressure pump in which the suction joint 51 is provided on a side surface (not shown) of the pump body 1.

  First, the present embodiment will be described with reference to FIG. The high-pressure pump of the present embodiment uses a mounting flange 1e provided on the pump body 1 to be in close contact with the plane of the cylinder head 90 of the internal combustion engine and is fixed with a plurality of bolts (not shown).

  An O-ring 61 is fitted into the pump body 1 for sealing between the cylinder head 90 and the pump body 1 to prevent engine oil from leaking to the outside.

  A cylinder for guiding the reciprocating motion of the plunger 2 is attached to the pump body 1. An electromagnetic suction valve 300 for supplying fuel to the pressurizing chamber 11 and a discharge valve mechanism 8 for discharging the fuel from the pressurizing chamber 11 to the discharge passage and preventing backflow are provided. The fuel that has passed through the discharge valve mechanism 8 is connected to engine-side components by a discharge joint 12c.

  The cylinder 6 is fixed to the pump body 1 by press-fitting on the outer peripheral side thereof. The surface of the cylindrical press-fitting portion is sealed so that fuel pressurized from the gap with the pump body 1 does not leak to the low pressure side. By bringing the cylinder into contact with a plane in the axial direction, in addition to the seal of the cylindrical press-fit portion of the pump body 1 and the cylinder 6, it also functions as a double seal.

  At the lower end of the plunger 2 is provided a tappet 92 that converts the rotational motion of the cam 93 attached to the camshaft of the internal combustion engine into vertical motion and transmits it to the plunger 2. The plunger 2 is pressure-bonded to the tappet 92 by the spring 4 through the retainer 15. Thereby, the plunger 2 can be reciprocated up and down with the rotational movement of the cam 93.

  A plunger seal 13 held at the lower end of the inner periphery of the seal holder 7 is installed in a slidable contact with the outer periphery of the plunger 2 at the lower part of the cylinder 6 in the figure. Thereby, when the plunger 2 slides, the fuel in the sub chamber 7a is sealed and prevented from flowing into the internal combustion engine. At the same time, lubricating oil (including engine oil) for lubricating the sliding portion in the internal combustion engine is prevented from flowing into the pump body 1.

  A suction joint 51 is attached to the pump body 1. The suction joint 51 is connected to a low-pressure pipe that supplies fuel from the fuel tank 20 of the vehicle, and the fuel is supplied from here to the inside of the high-pressure pump. The suction filter 52 in the suction joint 51 serves to prevent foreign matter existing between the fuel tank 20 and the low-pressure fuel inlet 10a from being absorbed into the high-pressure fuel supply pump by the flow of fuel.

  The fuel that has passed through the low-pressure fuel intake port 10a reaches the intake port 31b of the electromagnetic intake valve 300 via the pressure pulsation reducing mechanism 9 and the low-pressure fuel flow path 10d.

  The discharge valve mechanism 8 provided at the outlet of the pressurizing chamber 11 includes a discharge valve sheet 8a, a discharge valve 8b that contacts and separates from the discharge valve sheet 8a, and a discharge valve spring that urges the discharge valve 8b toward the discharge valve sheet 8a. 8c, and a stopper 8d that determines the stroke (movement distance) of the discharge valve 8b. The discharge valve stopper 8d and the pump body 1 are joined by welding at the contact portion 8e to block the fuel and the outside.

  In a state where there is no fuel differential pressure in the pressurizing chamber 11 and the discharge valve chamber 12a, the discharge valve 8b is pressed against the discharge valve seat 8a by the urging force of the discharge valve spring 8c and is closed. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the discharge valve chamber 12a, the discharge valve 8b opens against the discharge valve spring 8c. The high-pressure fuel in the pressurizing chamber 11 is discharged to the common rail 23 through the discharge valve chamber 12a covered with the discharge valve cover 12d, the fuel discharge passage 12b, and the fuel discharge port 12. When the discharge valve 8b is opened, the discharge valve 8b comes into contact with the discharge valve stopper 8d, and the stroke is limited. Accordingly, the stroke of the discharge valve 8b is appropriately determined by the discharge valve stopper 8d. As a result, it is possible to prevent the fuel that has been discharged at high pressure into the discharge valve chamber 12a from flowing back into the pressurizing chamber 11 again due to the delay in closing the discharge valve 8b due to the stroke being too large, and the efficiency of the high pressure pump is reduced. Can be suppressed. Further, when the discharge valve 8b repeats opening and closing movements, the discharge valve 8b is guided by the outer peripheral surface of the discharge valve stopper 8d so that the discharge valve 8b moves only in the stroke direction. By doing so, the discharge valve mechanism 8 becomes a check valve that restricts the flow direction of fuel.

  As described above, the pressurizing chamber 11 includes the pump housing 1, the electromagnetic suction valve 300, the plunger 2, the cylinder 6, and the discharge valve mechanism 8.

  When the plunger 2 moves in the direction of the cam 93 due to the rotation of the cam 93 and is in the suction stroke state, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. When the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction passage 10d in this stroke, the valve body 30 is in an open state. Therefore, the fuel passes through the opening formed by opening the valve body 30, passes through the communication hole 1 a provided in the pump body 1, the groove 6 a of the cylinder 6, and the communication hole 6 b and flows into the pressurizing chamber 11. To do.

  After the plunger 2 completes the suction stroke, the plunger 2 starts to move upward and moves to the compression stroke. Here, the electromagnetic coil 43 remains in a non-energized state and no magnetic biasing force acts. The rod biasing spring 40 is set to have a biasing force necessary and sufficient to keep the valve element 30 open in a non-energized state. In the present embodiment, a so-called normally open high pressure pump is shown, but the present invention is not limited to this, and can be applied to a normally closed high pressure pump. The volume of the pressurizing chamber 11 decreases with the compression motion of the plunger 2. In this state, the fuel once sucked into the pressurizing chamber 11 once again passes through the opening of the valve body 30 in the valve-opened state. Since the pressure is returned to 10d, the pressure in the pressurizing chamber does not increase. This process is called a return process.

  From here, the electromagnetic suction valve 300 will be described with reference to FIG. The electromagnetic suction valve 300 sucks fuel into the pressurizing chamber 11 by moving the magnetic core 39, the movable core 36, the rod 35 and the valve body 30 arranged following them by energizing the electromagnetic coil 43. Refers to the sending mechanism. These functions are described in detail below.

  As described above, in the non-energized state, the valve element 30 operates in the valve opening direction by the strong rod urging spring 40, so that it is normally open, but from the engine control unit 27 (hereinafter referred to as ECU). Is applied to the electromagnetic suction valve 300, a current flows through the electromagnetic coil 43 via the terminal 46. When the current flows, the magnetic core 39 generates a magnetic attractive force.

  Accordingly, the movable core 36 is attracted in the valve closing direction by the magnetic attractive force of the magnetic core 39 on the magnetic attractive surface S shown in FIG. Between the movable cores 36, a rod 35 having a flange portion 35a for locking the movable core 36 is disposed. The rod biasing spring 40 is covered with a lid holding member 39 and a lid member 44. Since the rod 35 has the flange portion 35 a, the movable core 36 can be locked, so that the rod 35 can move together with the movable core 36. Therefore, the rod 35 disposed between the movable cores 36 can move in the valve closing direction when a magnetic attractive force is applied. Further, the rod 35 is disposed between the valve closing biasing spring 41 and the rod guide portion 37 b provided with the fuel passage 37 at the lower part of the movable core.

  The rod 35 is an inner peripheral portion of the flange portion 35a, and a recessed portion 35b that is recessed toward the inner peripheral side is formed at a position where the rod 35 contacts the movable core 36. As a result, an escape portion when the movable core 36 comes into contact can be formed, so that damage due to the collision of the rod 35 or the movable core 36 can be prevented. Further, the rod 35 is formed with an inclined portion 35c whose diameter decreases toward the tip at the tip on the valve body 30 side. As a result, even when the movable core 36 is slightly displaced when the movable core 36 is inserted into the rod 35, it can be easily assembled and the production efficiency can be increased. In addition, since the rod 35 is formed by a lathe process, a concave portion that is recessed on the opposite side of the valve body 30 is formed at the distal end portion on the valve body 30 side.

  A valve body 30, a suction valve biasing spring 33, and a stopper 32 are provided below the rod 35 (on the suction valve side). The valve body 30 protrudes toward the pressurizing chamber, and a guide portion 30 b is formed that is guided by the suction valve biasing spring 33. The valve body 30 is moved by the gap of the valve body stroke 30e as the rod 35 moves, so that the fuel supplied from the supply passage 10d in the valve open state is supplied to the pressurizing chamber. The guide portion 30b is press-fitted into the housing of the suction valve mechanism, and stops moving when it collides with the fixed stopper 32. The rod 35 and the valve body 30 are separate and independent structures.

  The valve body 30 closes the flow path to the pressurizing chamber 11 by contacting the valve seat of the valve seat member 31 disposed on the suction side, and the flow path to the pressurizing chamber 11 by moving away from the valve seat. Configured to open. Here, in recent high-pressure fuel pumps, further increase in pressure is required, for example, the discharged fuel becomes 30 MPa or more. Therefore, the pressure chamber 11 becomes high pressure, and the valve body 30 collides with the valve seat member 31. The impact when the valve body 30 collides with the stopper 32 is very large, and it is necessary to increase the strength thereof.

  In this embodiment, the valve body 30 is arranged in a flat plate shape, and includes a flat plate portion and a guide portion 30b that protrudes toward the pressurizing chamber. In this embodiment, the thickness of the flat plate portion is focused on as an element that affects the strength. That is, the strength is improved by increasing the thickness of the flat plate portion of the valve body 30 in the moving direction of the suction valve biasing spring 33 as shown in FIG. Specifically, the thickness of the flat plate portion is made thicker than the thickness of the guide portion 30b protruding from the flat plate portion. FIG. 6 shows a cross-sectional view of the position where the suction port 31b (flow path) formed in the valve seat member 31 is the largest. At this time, it contacts the flat plate portion of the valve seat member 31 on the downstream side with respect to the suction port 31b. It is desirable to make the thickness of the flat plate portion of the valve body 30 larger than the thickness of the valve seat portion in the moving direction. By comprising in this way, it is possible to give the intensity | strength of the valve body 30. FIG.

  In summary, the magnetic urging force overcomes the urging force of the rod urging spring 40 and the rod 35 moves away from the intake valve 30. Therefore, the suction valve 30 is closed by the biasing force by the suction valve biasing spring 33 and the fluid force caused by the fuel flowing into the suction passage 10d. After the valve is closed, the fuel pressure in the pressurizing chamber 11 rises with the upward movement of the plunger 2, and when the pressure exceeds the pressure at the fuel discharge port 12, high-pressure fuel is discharged via the discharge valve mechanism 8 to the common rail 23. Supplied. This stroke is called a discharge stroke.

  That is, the compression stroke of the plunger 2 (the upward stroke from the lower start point to the upper start point) includes a return stroke and a discharge stroke. And the quantity of the high-pressure fuel discharged can be controlled by controlling the energization timing to the coil 43 of the electromagnetic suction valve 300. If the timing of energizing the electromagnetic coil 43 is advanced, the ratio of the return stroke during the compression stroke is small and the ratio of the discharge stroke is large. That is, the amount of fuel returned to the suction passage 10d is small and the amount of fuel discharged at high pressure is large. On the other hand, if the energization timing is delayed, the ratio of the return stroke during the compression stroke is large and the ratio of the discharge stroke is small. That is, the amount of fuel returned to the suction passage 10d is large, and the amount of fuel discharged at high pressure is small. The energization timing to the electromagnetic coil 43 is controlled by a command from the ECU 27.

  By controlling the energization timing to the electromagnetic coil 43 as described above, the amount of fuel discharged at high pressure can be controlled to an amount required by the internal combustion engine. The relief valve 200 includes a relief valve cover 201, a ball valve 202, a relief valve presser 203, a spring 204, and a spring holder 205. The relief valve 200 is a valve that is configured to operate only when a problem occurs in the common rail 23 or the member ahead and the pressure becomes abnormally high, and the pressure in the common rail 23 or the member ahead is increased. The valve is opened only in the event of a failure and returns the fuel to the pressurized chamber. Therefore, it has a very strong spring 204.

  The low-pressure fuel chamber 10 is provided with a pressure pulsation reduction mechanism 9 that reduces and reduces the pressure pulsation generated in the high-pressure pump from spreading to the fuel pipe 28. In addition, a damper upper portion 10b and a damper lower portion 10c are provided above and below the pressure pulsation reducing mechanism 9 with a gap therebetween. When the fuel that has once flowed into the pressurizing chamber 11 is returned to the suction passage 10d through the intake valve body 30 that is opened again for capacity control, the fuel returned to the suction passage 10d causes the pressure in the low-pressure fuel chamber 10 to be reduced. Pulsation occurs. However, the pressure pulsation reducing mechanism 9 provided in the low-pressure fuel chamber 10 is formed of a metal diaphragm damper in which two corrugated disk-shaped metal plates are bonded together on the outer periphery and an inert gas such as argon is injected inside. The pressure pulsation is absorbed and reduced by expansion and contraction of the metal damper. Reference numeral 9b denotes a mounting bracket for fixing the metal damper to the inner peripheral portion of the pump body 1, and since it is installed on the fuel passage, the support portion with the damper is not part of the entire circumference but part of the mounting bracket 9b. It allows fluid to flow back and forth freely.

  The plunger 2 has a large-diameter portion 2a and a small-diameter portion 2b, and the volume of the sub chamber 7a increases or decreases as the plunger reciprocates. The sub chamber 7a communicates with the low pressure fuel chamber 10 through a fuel passage 10e. When the plunger 2 descends, fuel flows from the sub chamber 7a to the low pressure fuel chamber 10, and when it rises, fuel flows from the low pressure fuel chamber 10 to the sub chamber 7a.

  As a result, the flow rate of fuel into and out of the pump during the intake stroke or return stroke of the pump can be reduced, and the pressure pulsation generated inside the high-pressure pump is reduced.

  4 and 8 are cross-sectional views in the vertical and horizontal directions when a low-pressure fuel inlet is connected to the pump body 1 in the lateral direction. The reference numerals of the drawings are omitted because they overlap with the description of the above-described drawings. By using the configuration described in the present embodiment, it is possible to easily perform welding while preventing stress concentration regardless of the orientation of the low-pressure fuel inlet. The contents of the invention will be described in detail below.

  In this high-pressure fuel pump, it is desired that the suction joint 51, the discharge joint 12c, or the electromagnetic suction valve mechanism 300, which are functional parts, be freely installed in the radial direction with respect to the high-pressure fuel pump. This is to increase the degree of freedom of layout in the engine.

  The high-pressure fuel pump and the functional parts are joined by welding. Here, when the functional parts protruding outward from the outer surface of the pump body 1 are coupled by, for example, laser welding, the beams for laser welding need to be arranged without interfering with each other's functional parts or the flange 1e. There is.

  For example, when welding the discharge joint 12c, the laser beam 500 is irradiated as shown in FIG. 1, but it is necessary to arrange the beam so as not to interfere with the flange 1e and other functional parts. At this time, if the laser beam 500 is irradiated so as to be more parallel to the axial direction of the functional component, interference can be prevented, and the degree of freedom of arrangement of the functional components can be further increased.

  At the same time, it is necessary to sufficiently secure the reliability of the connecting portion between each functional component and the body 1 in order to prevent the fuel inside the pump from leaking to the outside. In other words, it is necessary to ensure a sufficient strength for the connecting portion.

  As described above, in order to increase the degree of freedom of the arrangement of these functional parts and to ensure the reliability of the coupling parts of the functional parts, the high-pressure pump of this embodiment is provided with a hole formed in the pump body 1. As shown in FIG. 5, for example, a discharge joint 12c is provided, and the outer peripheral part of the functional part and the inner peripheral part of the hole are fixed on the contact surface 12e by welding on the outer peripheral face of the pump body 1. Then, a space 400 is formed on the side opposite to the outer peripheral surface with respect to the welded portion.

  When the space 400 is not provided, stress concentrates on the joint during welding, and a notch shape having an acute angle or a small corner radius may be formed. However, in the case where the space 400 is provided, in order to have a sufficient space volume, a notch shape having a small acute angle or a small corner radius is generated so that stress is concentrated in the vicinity of the welded portion, particularly the weld end portion 401. do not do. Therefore, even when a load is applied to the welded portion, it can be shaped so as not to cause stress concentration in the welded portion.

  With the above configuration, it is possible to provide a high-pressure fuel pump that suppresses stress concentration at the welded part of the welded part and improves the reliability of the pump. In addition, the space 400 is formed by providing an annular recess shape in both the pump body 1 and the functional component. For example, specifically, the annular recess shape 1f of the body and the annular recess shape 12f of the discharge joint 12 are provided. As a result, stress concentration can be suppressed and the reliability of the pump can be improved as compared with the case where only one of the parts is provided with an annular concave shape. At this time, it is desirable that the concave shape is not a square but a shape close to a circle. This is because when the shape is close to a quadrangle, stress tends to concentrate on the corners.

  Next, as described in claim 3, the functional component has a diameter of a portion protruding from the surface of the pump body 1, for example, a diameter of the protruding portion of the discharge joint, for example, a diameter of an outer peripheral portion facing the hole, for example, a discharge joint. The weld portion diameter 12h is configured to be large. With this configuration, it is possible to facilitate laser welding along the axial direction of the functional component. Here, FIG. 4 and FIG. 8 show sectional views in the vertical and horizontal directions of the pump body 1 when the low-pressure fuel inlet 10a is connected in the horizontal direction for the convenience of the engine. As described above, even when there are many lateral connections of the functional parts and the low-pressure fuel inlet 10a, welding can be easily performed by applying the laser from the axial direction of the functional parts.

  Further, as described in claim 4, it is desirable that the size 402 in the radial direction of the space is larger than the difference 12i between the diameter of the protruding part of the functional component and the diameter of the outer peripheral part. It is possible to suppress the stress concentration described above by setting the space to such a size.

  Furthermore, it is preferable that the cross-sectional area created by the recessed shape 1f of the body 1 is larger than the cross-sectional area created by the recessed shape 12f of the functional component. Specifically, when actually operating the pump, the stress generated on the body side becomes larger due to the pressure applied inside the pump, so it is necessary to diffuse the stress concentration in a large space and avoid stress concentration. Is possible.

  It is desirable that a contact portion 12j is provided in the coupling portion on the center side of the body 1 in the space 400. The advantages of installing the contact part 12j are the following two points. One is suppression of the inclination by welding of the discharge joint 12c, and two is prevention of penetration of spatter (fine metal powder) generated during welding into the pump.

  The space 400 a is a space in a portion where the electromagnetic suction valve mechanism 300 is welded to the body 1. An annular recess shape is formed on the body 1 side, and the space 400a can be formed also on the electromagnetic suction valve mechanism 300 side.

  Here, as described in claim 5, it is desirable that the functional component and the hole are welded by applying a laser along the insertion direction of the functional component. For example, when laser welding is performed, laser welding cannot be performed if a flange portion is disposed between the laser irradiation portion and the welding portion. In other words, it is necessary to dispose the flange portion and other functional parts so that other members such as the flange portion are not interposed between the laser irradiation portion and the weld portion. That is, in this case, since the layout of the flange portion and other functional parts is limited, it can be said that the layout is poor. On the other hand, the layout can be improved by configuring the functional parts and the holes as described above.

  Further, as described in claim 6, the pump body 1 is provided with a flange portion for attaching the high-pressure fuel pump to the engine, and it is desirable that the pump body 1 and the flange portion are integrally formed by forging. Compared with the case where it is configured separately and welded and fastened, the number of parts can be reduced, and improvement in reliability as a structure can be expected.

  As described in claim 7, this space is formed in an annular shape over the entire circumference of the outer peripheral portion of the functional component. Specifically, as described in claim 8, the space 400 is formed in an annular shape over the entire circumference between the pump body 1 and the functional component. This is because the welded portion also serves as a sealing function for the fuel inside the pump and to ensure strength. For this reason, it is necessary to weld the entire circumference between the pump body 1 and the functional parts, and to disperse the stress.

  According to the ninth aspect of the present invention, in the sectional view in the axial direction of the functional component, the sectional area of the annular concave shape provided in the pump body 1 is larger than the sectional area of the annular concave shape provided in the functional component. It is characterized by being. This is because the stress generated in the pump body 1 tends to be larger than the stress generated in the functional parts when the pump is actually operated. This configuration is provided in order to play a role of distributing stress applied during actual operation.

  The functional component indicated in the present embodiment is any one of the suction joint 51 for sucking in the fuel, the discharge joint 12 for discharging the fuel pressurized in the pressurizing chamber, or the electromagnetic suction valve mechanism 300 as described in claim 10. It is. The pump body 1 that is required to have a higher welding strength is not limited to the above, and the present embodiment can be applied.

  This is the end of the description of the examples, but the present invention is not limited to the above-described embodiment, and can be widely modified and implemented. For example, in the above-described embodiment, the present invention is applied to a high-pressure fuel pump, but the above-described embodiment also applies to the position and method of arrangement of functional components in a high-pressure fuel pump that may be applied to metal parts that require welding. It is not restricted to the example of.

DESCRIPTION OF SYMBOLS 1 Pump body 2 Plunger 6 Cylinder 7 Seal holder 8 Discharge valve mechanism 9 Pressure pulsation reduction mechanism 10a Low pressure fuel suction port 11 Pressurization chamber 12 Fuel discharge port 13 Plunger seal 30 Suction valve 36 Anchor 40 Rod biasing spring 43 Electromagnetic coil 100 Pressure Pulsation propagation preventing mechanism 101 Valve seat 102 Valve 103 Spring 104 Spring stopper 200 Relief valve 300 Electromagnetic suction valve 400 Welding space 500 Laser beam

Claims (10)

With functional parts inserted into holes formed in the pump body,
The first contact portion between the outer peripheral portion of the functional component and the inner peripheral portion of the hole is fixed by welding on the outer peripheral surface,
A space is formed on the opposite side of the outer peripheral surface with respect to the welded part ,
A second contact portion where the outer peripheral portion of the functional component formed toward the insertion direction of the functional component and the inner peripheral portion of the hole portion are provided separately from the welded portion,
Toward the center side from the outer peripheral surface of the pump body, the welded portion, the space, high-pressure fuel pump, characterized that you position in the order of the second contact portion. The high-pressure fuel pump according to claim 1,
The space is formed by providing a recessed shape in both the pump body and the functional component ,
In the axial sectional view of the functional part, the high-pressure fuel pump is characterized in that a recessed sectional area provided in the pump body is larger than a recessed sectional area provided in the functional part . The high-pressure fuel pump according to claim 1,
The high-pressure fuel pump, wherein the functional component is configured such that a diameter of the outer peripheral portion facing the hole is larger than a diameter of a portion protruding from a surface of the pump body. The high-pressure fuel pump according to claim 3,
The high-pressure fuel pump, wherein a size of the space in a radial direction is large with respect to a difference between a diameter of a protruding portion of the functional component and a diameter of the outer peripheral portion. The high-pressure fuel pump according to claim 1,
A step portion for positioning the functional component is provided on the inner peripheral portion of the hole portion,
A high-pressure fuel pump, wherein a third contact portion that comes into contact with the step portion in a plane perpendicular to the insertion direction is provided at a tip of the functional component in the insertion direction . The high-pressure fuel pump according to claim 1,
A flange for attaching the high-pressure fuel pump to the engine;
The high-pressure fuel pump, wherein the pump body and the flange portion are integrally formed by forging. The high-pressure fuel pump according to claim 1,
The high-pressure fuel pump, wherein the space is formed in an annular shape over the entire circumference of the outer peripheral portion of the functional component. The high-pressure fuel pump according to claim 1,
The high-pressure fuel pump is characterized in that the space is formed in an annular shape over the entire circumference between the pump body and the functional component. The high-pressure fuel pump according to claim 1,
The high-pressure fuel pump according to claim 1, wherein the functional parts in the first contact portion and the second contact portion have the same outer diameter . The high-pressure fuel pump according to claim 1,
The high-pressure fuel pump, wherein the functional component is any one of a suction joint for sucking fuel, a discharge joint for discharging fuel pressurized in a pressurizing chamber, and an electromagnetic suction valve mechanism.

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