JP2013199873A - High-pressure fuel supply pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure fuel supply pump with enhanced quality by applying a technique to form a space capturing the sputter splashing to the side opposite the beam irradiation surface of the butting surfaces to a welding join between a pump housing and a mounting flange, suppressing the splashing of the sputter when the pump housing and the mounting flange are welded together, and reducing attachment to the pump housing external wall and other components.SOLUTION: A high-pressure fuel supply pump includes a pump housing where a projection is protruding outward about the radial direction in such a manner as to cover the welding join on the side opposite the beam irradiation surface in the neighborhood of the welds of the welding join between the pump housing and the mounting flange.

Description

  The present invention relates to a high-pressure fuel supply pump that supplies high-pressure fuel to a fuel injection valve of a direct injection internal combustion engine.

  The high-pressure fuel supply pump has a plunger that slides into the cylinder, and the tip of the plunger reciprocates in the pressurizing chamber, thereby compressing and pressurizing the fuel introduced from the suction valve mechanism into the pressurizing chamber, and a discharge valve mechanism. Discharge from.

  In the conventional high-pressure fuel supply pump, for example, as described in Japanese Patent Application Laid-Open No. 2011-1865, the annular outer peripheral portion of the pump housing on the side opposite to the pressurizing chamber and the inner peripheral portion of the mounting flange are fitted, In the fitting portion, a mounting flange is through-welded with a welding beam.

Japanese Unexamined Patent Publication No. 2011-1865 JP 2005-279778 A

  In such a configuration, when the mounting flange is welded to the annular outer periphery of the pump housing with a welding beam, the metal spatter melted by the heat during welding is pressed on the mounting flange on the opposite side of the welding beam irradiation surface. A large amount is generated and scattered on the room side. The spatter that scatters adheres to the pump housing outer wall and other parts. For this reason, there is a possibility that the external quality is deteriorated and the spatter falls off and is mixed as a foreign substance inside the pump.

  Here, in a high-pressure fuel supply pump, as described in, for example, Japanese Patent Application Laid-Open No. 2005-279778, a welding seam is formed as a butt seam by laser irradiation on the butt surface between the thick pump housing and the thin cover. What to do is known. In this conventional example, it is known to provide a space for capturing spatter scattered on the opposite side of the abutting surface between the cover and the pump housing from the welding beam irradiation surface.

  The purpose of the present invention is to apply the technology to the welded joint between the pump housing and the mounting flange, to suppress spatter scattering during welding of the pump housing and the mounting flange, and to reduce adhesion to the outer wall of the pump housing and other parts. Thus, an object is to provide a high-pressure fuel supply pump with improved quality.

  In the present invention, in order to achieve the above-mentioned object, a protrusion protruding outward in the radial direction so as to cover the weld joint on the opposite side of the weld beam irradiation surface in the vicinity of the weld joint of the weld joint of the pump housing and the mounting flange. The part is configured to provide a pump housing.

  According to the present invention configured as described above, when the mounting flange is welded to the pump housing with a welding beam, the protrusion becomes a wall and the sputter is formed between the joint between the pump housing and the mounting flange and the protrusion. The spatter melted by the heat during welding can be prevented from being scattered around. This makes it difficult for the spatter to scatter around the opposite side of the welding beam irradiation surface, and it is possible to reduce spatter adhesion to the outer wall of the pump housing and other parts.

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. The enlarged view near the annular fixed part of the high-pressure fuel supply pump according to the first embodiment in which the present invention is implemented is shown. The enlarged view of the vicinity of the annular fixing portion of the high-pressure fuel supply pump according to the first embodiment in which the present invention is implemented is shown and is enlarged compared with FIG. The enlarged view near the annular fixed part of the high-pressure fuel supply pump according to the second embodiment in which the present invention is implemented is shown. The enlarged view near the annular fixed part of the high-pressure fuel supply pump according to the third embodiment in which the present invention is implemented is shown. The enlarged view of the annular fixing part vicinity of the high-pressure fuel supply pump by 4th Example by which this invention was implemented is shown.

  Embodiments according to the present invention will be described below with reference to the drawings.

  In the present embodiment shown in FIGS. 1, 2, and 3, a cylinder 3 is fixed to the pump housing 1, and a plunger 2 that slides back and forth with the cylinder 3 is provided.

  A pressurizing chamber 4 defined by the pump housing 1 and the cylinder 3 is provided, and one end of the plunger 2 enters and exits the pressurizing chamber 4.

  A protrusion 5a is provided in the vicinity of the annular outer peripheral portion 5 on the engine mounting side of the pump housing 1, and the protrusion 5a is located on the side opposite to the irradiation surface of the welding beam. There is a gap between the lower end surface S2 of the protrusion 5a and the upper end surface S3 of the mounting flange 6.

  The annular outer peripheral portion 5 of the pump housing 1 and the inner peripheral portion of the mounting flange 6 are fitted to form an annular fixing portion 6a that is fixed by a welding beam.

  The protruding portion 5a has a cylindrical portion S1 that surrounds the outer periphery, and the cylindrical portion S1 has a larger radial dimension than the annular fixing portion 6a.

  According to the configuration as described above, even when the plate thickness t2 of the mounting flange 6 is through-welded by the welding beam, the spatter scattering is prevented by the protrusions 5a provided in the pump housing 1, so that the pressure chamber 4 side It becomes possible to reduce the amount of spatter adhering to the pump housing outer wall and other parts.

  At least two screwing portions (7, 8, 6b, 8a, 8b, 8c) for fixing the mounting flange 6 to the engine member 100, a pump housing outer wall portion on the pressure chamber 4 side, and an annular fixing portion 6a It is provided in between.

  The screwing portions (7, 8, 6b, 8a, 8b, 8c) are bolts 7 that pass through holes 6b provided in the mounting flange 6, and fasteners that are sandwiched between the head 7A of the bolt 7 and the mounting flange 6. Nine. Further, the bush 8 has a protrusion at the base. In addition, an annular protrusion 8b inserted into a hole 6b provided in the mounting flange 6 is provided at the center. As a result, the bolt 7 passes through the hole 8 c passing through the center of the bush 8 and is screwed into the engine mounting member 100.

  The bush 8 has a radial dimension that is larger on the mounting flange 6 side than the head 7A side of the bolt 7 at least in a part in the circumferential direction.

  A fastener 9 is narrowly attached to a hole 8 c located between the inner peripheral surface of the bush 8 and the outer peripheral surface of the bolt 7.

  On the side of the annular fixing portion 6a facing the engine mounting member 100, a recess 10 as an annular groove is provided inside and outside in the radial direction across the annular fixing portion 6a.

  Hereinafter, the configuration of the high-pressure fuel pump according to the embodiment will be described in more detail with reference to FIGS. 1 to 3.

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

  The high-pressure fuel supply pump is fixed to the engine by the flange 6, the bolt 7, and the bush 8. The flange 6 is welded to the pump housing 1 by an annular fixing portion 6a. In this embodiment, a welding beam is used.

  As shown in FIG. 1, the flange 6 fixes the pump housing 1 to the engine by two bolts 7.

  The two bushes 8 are attached to the flange 6 and are attached to the opposite side of the engine. The two bolts 7 are screwed into respective screws formed on the engine side, and the high pressure fuel supply pump is fixed to the engine by pressing the two bushes 8 and the flange 6 against the engine.

  FIG. 2 shows an enlarged view of the flange 6, the bolt 7, and the bush 8 part.

  The bush 8 includes a flange portion 8a and a caulking portion 8b. First, the caulking portion 8 b is caulked and joined to the mounting hole of the flange 6. Thereafter, the pump housing 1 and the annular fixing portion 6a are welded together by a welding beam. Thereafter, the resin fastener 9 is inserted into the bush 8, and the bolt 7 is further inserted into the fastener 9. The fastener 9 serves to temporarily fix the bolt 7 to the bush 8. That is, the bolt 7 is fixed so that it does not fall off the bush 8 until the high-pressure fuel supply pump is attached to the engine. When the high-pressure fuel supply pump is fixed to the engine, the bolt 7 is screwed and fixed to a screw portion provided on the engine side. At this time, the bolt 7 can be rotated in the bush 8 by the tightening torque of the bolt 7.

  Before the high-pressure fuel supply pump is fixed to the engine, the bolt 7 is attached to the high-pressure fuel supply pump and a drop-off prevention mechanism is provided. However, when the bolt 7 is attached to the engine, the fastener 9 is particularly unnecessary.

  The flange 6 is manufactured by press molding for productivity reasons. In this embodiment, the plate thickness t1 of the flange 6 is 4 mm. The annular outer peripheral portion 5 of the pump housing 1 and the inner peripheral portion of the mounting flange 6 are fitted to form an annular fixing portion 6a that is fixed by a welding beam.

  The welding beam needs to be irradiated from below in the figure. From the upper side in the figure, there are other parts and it is impossible to irradiate the welding beam over the entire circumference. Furthermore, the welding beam must penetrate the plate thickness t = 4 mm of the flange 6. If welding does not pass through the flange 6, the end face of the welded portion becomes a notch, and stress is concentrated in the notched portion due to the repeated load generated along with the high-pressure discharge, thereby causing fatigue failure.

  In order to weld through the flange 6 with the welding beam, it is sufficient to increase the output of the welding beam. However, since heat is always generated for welding, the flange 6 is thermally deformed by the heat. From the above viewpoint, it is better that the welding length for penetration welding with the welding beam is short.

  For this reason, only the thickness t2 of the annular fixing portion 6a is set to t2 = 3 mm. Thereby, the flange 6a can be through-welded by the welding beam. Further, since this t2 = 3 mm portion can be formed by press molding, the productivity is high.

  However, as a drawback of through welding, a large amount of spatter melted by heat during welding is generated on the pressure chamber 4 side of the mounting flange 6 on the opposite side of the welding beam irradiation surface and scattered around. This spatter adheres to the outer wall of the pump housing 1 and other parts. Furthermore, there is a problem that spatter falls off during assembly and enters the pump as foreign matter. In the valve seat portion that seats the fuel inside the pump, there is a possibility that the mixed spatter may cause a failure in function due to biting into the seat portion.

  Therefore, in this embodiment, the annular fixing portion 6a fixed by the welding beam between the pump housing 1 and the mounting flange 6 is provided with a protrusion 5a in the vicinity of the annular fixing portion 6a on the side opposite to the welding beam irradiation surface. Thereby, even when the plate thickness t2 of the mounting flange 6 of the annular fixing portion 6a is welded by the welding beam, the spatter scattering is prevented by the projection 5a provided on the pump housing 1, so that the outer wall of the pump housing on the pressurizing chamber 4 side is prevented. It is possible to reduce the amount of spatter adhering to the part and other parts.

  With the above configuration, it is possible to reduce the risk of spatter scattering even when the welding beam output is increased and the welding beam penetration width is expanded, so that the degree of freedom of the welding process is increased and the soundness of the welding quality is improved. Is possible.

  The step portion having the plate thickness t2 = 3 mm and t1 = 4 mm of the annular fixing portion 6a is provided on the engine side. Thereby, the hollow part 10 is formed. The upper end surface and the lower end surface of the annular fixing portion 6a are always raised above the base material. By providing the depression 10, it is possible to prevent this swell and engine interference. When the swell and the engine are in contact, when the high-pressure fuel supply pump is fixed to the engine with the bolt 7, bending stress is generated in the flange 6, leading to breakage of the flange 6.

  Thereby, breakage of the flange 6 can be prevented by the repeated load generated along with the high pressure discharge. Further, it is possible to prevent the flange 6 from being damaged due to contact between the raised portion of the annular fixing portion 6a and the engine.

  Next, a second embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the first embodiment is only that the lower end surface S2 of the protrusion 5a and the upper end surface S3 of the mounting flange 6 are in contact with each other. All the symbols and numbers described are the same as those in the first embodiment.

  In this configuration, even when the plate thickness t2 of the mounting flange 6 of the annular fixing portion 6a is welded by the welding beam, the welding beam does not penetrate the protruding chamber 5a provided on the pump housing 1 to the pressurizing chamber 4 side. For this reason, it is possible to prevent spatter scattering of the mounting flange 6 on the side opposite to the welding beam irradiation surface to the pressure chamber 4 side.

  Next, a third embodiment of the present invention will be described with reference to FIG. The difference between the present embodiment and the second embodiment is different only in that an annular cavity 5b serving as a sputter pool is provided on the contact surface portion with the annular fixing portion 6a interposed therebetween. All the symbols and numbers described are the same as those in the second embodiment.

  In this configuration, even when the plate thickness t2 of the mounting flange 6 of the annular fixing portion 6a is welded by the welding beam, the spatter can be confined in the annular cavity portion 5b provided in the pump housing 1. Spatter scattering to one outer wall part and other parts can be prevented.

  Moreover, since the annular cavity 5b plays the role of degassing, it is possible to improve the soundness of the welding quality by reducing the risk of blowhole generation due to gas entrainment during welding.

  Next, the fourth embodiment shown in FIG. 6 of the present invention shows another embodiment of the third embodiment. All the symbols and numbers described are the same as those in the third embodiment.

DESCRIPTION OF SYMBOLS 1 Pump housing 2 Plunger 3 Cylinder 4 Pressurizing chamber 5 Annular outer peripheral part 5a Projection part 5b Cavity part 6 Flange 6a Annular fixed part

Claims (4)

A cylinder fixed to the pump housing and a plunger slidingly reciprocating on the cylinder;
A pressurizing chamber defined by the pump housing and the cylinder and into which one end of the plunger enters and exits;
A mounting flange fixed to the pump housing by an annular fixing portion formed on an annular outer peripheral portion of the pump housing on the side opposite to the pressure chamber;
At least two screwing portions for fixing the mounting flange to the engine member;
In the pump having a welding beam irradiation surface for welding the annular fixing portion on the side of the annular fixing portion facing the engine member,
An annular protrusion that protrudes outward in the radial direction so as to cover the annular joint formed in the welded portion is provided in the vicinity of the welded portion and on the opposite side of the welding beam irradiation surface. High pressure fuel supply pump characterized by In claim 1,
A high-pressure fuel supply pump characterized by having an annular groove inside and outside in the radial direction with the annular fixing portion sandwiched at a position on the welding beam irradiation surface side of the welding portion. In claim 1,
A high-pressure fuel supply pump having a contact surface with which the upper end surface of the mounting flange contacts the lower end surface of the protrusion. In claim 3,
An annular cavity as a spatter pool is formed on the contact surface side of the welded portion.