Press-fit injector copper sleeve device

Abstract

The invention discloses a press-fit copper sleeve device for a fuel injector. The device comprises: a sleeve, the lower part of which has an end face for pressing the copper sleeve of the fuel injector; a stepped guide hole is provided in the middle core of the sleeve; a limit flange is fixed on the upper end of the sleeve; an end cover is slidably fitted in the sleeve; a force transmission sleeve is arranged on the inner side of the end cover; a mandrel is inserted into the sleeve, a spiral groove is provided on the shaft of the mandrel, a limit flange is provided on the upper part, and the mandrel is matched with the force transmission sleeve through a one-way thrust ball bearing; an arc-shaped ejector pin is provided at the lower part of the mandrel; a guide limit locking screw is inserted into the side of the sleeve, and the guide limit locking screw has a ball head arc surface; a pressure spring is provided between the sleeve and the end cover; and a return spring. The press-fit copper sleeve device for a fuel injector can avoid the generation of pull marks on the surface of the intermediate forming hole, and can ensure the coaxiality between the forming hole axis and the injector copper sleeve axis.

Description

Technical Field

[0001] The invention relates to the field of engines, in particular to a press-fitted fuel injector copper sleeve device. Background Art

[0002] At present, the process of pressing the copper sleeve of the fuel injector on the cylinder head of the diesel engine generally uses a moving mandrel to press down a fixed-size ball (the ball is not connected to the mandrel, and the ball is collected and reused) or directly uses the outer cylindrical surface of the mandrel to swell and press the mold. The former can only guarantee the local size (diameter) value of the middle formed inner hole of the outer cylinder of the boss of the lower end face of the copper sleeve of the fuel injector, but cannot guarantee the coaxiality of the axis of the formed hole and the axis of the copper sleeve of the fuel injector and the straightness of the formed hole itself. The latter will produce a scratch on the surface of the middle formed hole during the movement of the mandrel (pressing down and pulling out), and at the same time, it cannot guarantee the coaxiality of the axis of the formed hole and the axis of the copper sleeve of the fuel injector.

[0003] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to provide a press-fitting copper sleeve device for a fuel injector with a simple and reasonable structure, which can avoid the generation of pull marks on the surface of the intermediate forming hole and ensure the coaxiality between the axis of the forming hole and the axis of the copper sleeve of the fuel injector.

[0005] To achieve the above-mentioned purpose, the present invention provides a press-fit injector copper sleeve device, comprising: a sleeve, the lower part of which has an end face for pressing the injector copper sleeve; a stepped guide hole is provided in the middle core of the sleeve; a limit flange is fixed to the upper end of the sleeve; an end cover is slidably fitted in the sleeve for bearing and transmitting the pressure from the press; a force transmission sleeve is arranged on the inner side of the end cover for transmitting the pressure; a mandrel is inserted in the sleeve, the shaft of the mandrel is provided with a spiral groove, and the upper part is provided with a A limit flange cooperates with the power transmission sleeve through a one-way thrust ball bearing; an arc-shaped ejector is arranged at the lower part of the core shaft; a guide limit locking screw is penetrated through the side of the sleeve, and the guide limit locking screw has a ball head arc surface, which is used to cooperate with the spiral groove of the core shaft to realize rotational guidance; a pressure spring is arranged between the sleeve and the end cover, and is used to transmit the pressure of the press and the return of the end cover; and a return spring is arranged between the one-way thrust ball bearing and the sleeve, and is used for the return of the core shaft.

[0006] In a preferred embodiment, the shaft is provided with an elastic retaining ring at the upper end of the mandrel.

[0007] In a preferred embodiment, the limiting flange is fixed to the upper end of the shaft sleeve by means of a hexagon socket head screw.

[0008] In a preferred embodiment, an annular groove is provided between the stepped guide holes of the sleeve for positioning the return spring.

[0009] Compared with the prior art, the press-fitted copper sleeve device for fuel injector according to the present invention has the following beneficial effects: the press-fitted copper sleeve device for fuel injector can avoid scratches on the surface of the intermediate forming hole and ensure the coaxiality between the axis of the forming hole and the axis of the copper sleeve of the fuel injector. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the front structural view of a press-fitted injector copper sleeve device according to one embodiment of the present invention.

[0011] Figure 2 It is a schematic cross-sectional structure diagram of the AA direction of a press-fitted injector copper sleeve device according to one embodiment of the present invention.

[0012] Figure 3 The figure is a schematic diagram of the use structure of a press-fitted injector copper sleeve device according to one embodiment of the present invention.

[0013] Figure 4 It is a schematic structural diagram of the initial compression state of the press-fitted copper sleeve device of the fuel injector according to one embodiment of the present invention.

[0014] Figure 5 The figure is a schematic structural diagram of a press-fit injector copper sleeve device in a state where pressing is completed according to an embodiment of the present invention.

[0015] Figure 6 The figure is a schematic diagram of the cross-sectional structure of a shaft sleeve of a press-fitted copper sleeve device for a fuel injector according to an embodiment of the present invention.

[0016] Figure 7 The figure is a schematic diagram of the core shaft structure of a press-fitted copper sleeve device for a fuel injector according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0018] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0019] like Figures 1 to 6As shown, the specific structure of the press-fitted copper sleeve device for fuel injector according to the preferred embodiment of the present invention includes: an end cover 1, an elastic clamp ring for shaft 2, a limit flange 3, a force transmission sleeve 4, a one-way thrust ball bearing 6, a pressure spring 7, a return spring 8, a core shaft 9, a sleeve 10 and a guide limit locking screw 11. The press-fitted copper sleeve device for fuel injector can avoid the generation of pull marks on the surface of the intermediate forming hole and can ensure the coaxiality of the axis of the forming hole and the axis of the copper sleeve of the fuel injector.

[0020] Specifically, if Figure 6 As shown, the sleeve 10 is a basic assembly, and its lower part has an end face for pressing the copper sleeve of the fuel injector; an outer cylindrical surface for positioning the copper sleeve of the fuel injector is provided in the middle part, and a screw hole for a guide limit locking screw is provided for fixing the guide limit locking screw 11. A limit flange screw hole is provided on the upper end face. The middle core of the sleeve 10 is provided with two guide holes of different diameters (and a gap is avoided between the two guide holes) for matching with the cylindrical surfaces of different parts of the rod of the core shaft 9, and an annular groove is provided at the inner flange of the middle part for positioning the return spring 8.

[0021] The limiting flange 3 is fixed to the upper end of the shaft sleeve 10 by means of a hexagon socket head screw 5 , and is used for limiting the position of all movable parts arranged in the shaft sleeve 10 .

[0022] The outer cylindrical surface of the end cover 1 and the inner hole of the sleeve 10 are installed in a sliding manner to withstand and transmit the pressure from the press 12 and ensure that the line of action of the force is along the axial direction.

[0023] The force transmission sleeve 4 is arranged on the inner side of the end cover 1 for transmitting pressure.

[0024] like Figure 7 As shown, the mandrel 9 is inserted into the sleeve 10, and the rod diameters at different positions cooperate with the two guide holes of different diameters of the part 10 (sleeve) for axial direction guidance. The rod body of the mandrel 9 is provided with a spiral groove, which cooperates with the arc surface of the ball head of the guide limit locking screw 11 after assembly for rotation guidance. The upper part of the mandrel 9 is provided with a limit flange, which cooperates with the force transmission sleeve 4 through a one-way thrust ball bearing 6 (2 places). The lower part of the mandrel 9 is provided with an arc-shaped ejector pin.

[0025] The shaft elastic clamp ring 2 is arranged at the upper end of the core shaft 9, and is used to prevent the core shaft 9 from falling off after assembly.

[0026] The pressure spring 7 is arranged between the shaft sleeve 10 and the end cover 1 for transmitting the press pressure and returning the end cover 1 .

[0027] The return spring 8 is arranged between the one-way thrust ball bearing 6 and the annular groove of the inner flange of the middle part of the sleeve 10, and is used for returning the core shaft 9. The dimensions ФA1\ФA2, Фb\Фb1, Фc\Фc1 of each matching part are required to have the matching properties of the tooling level, and the material has high wear resistance.

[0028] In summary, the press-fitted copper sleeve device for the fuel injector can avoid scratches on the surface of the intermediate forming hole and ensure the coaxiality between the axis of the forming hole and the axis of the copper sleeve of the fuel injector.

[0029] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A press-fitted copper sleeve device for a fuel injector, characterized in that: include: The shaft sleeve has an end surface at the bottom thereof for pressing the copper sleeve of the fuel injector; a stepped guide hole is formed in the middle core of the shaft sleeve; A limiting flange fixed to the upper end of the shaft sleeve; An end cover is slidably fitted in the shaft sleeve and is used to bear and transmit the pressure from the press; A force transmission sleeve, which is arranged on the inner side of the end cover and is used for transmitting pressure; A mandrel is inserted into the sleeve, a spiral groove is provided on the shaft of the mandrel, a limited flange is provided on the upper part, and the mandrel cooperates with the force transmission sleeve through a one-way thrust ball bearing; an arc-shaped ejector pin is provided at the lower part of the mandrel; A rotation guide limit locking screw is inserted into the side surface of the sleeve, and the rotation guide limit locking screw has a ball head arc surface, which is used to cooperate with the spiral groove of the core shaft to realize rotation guidance; A pressure spring, which is arranged between the shaft sleeve and the end cover and is used to transmit the press pressure and return the end cover; and A return spring, which is arranged between the one-way thrust ball bearing and the shaft sleeve and is used for returning the core shaft; Wherein, an elastic shaft clamp is provided at the upper end of the core shaft; The limiting flange is fixed to the upper end of the shaft sleeve by means of a hexagon socket cylindrical head screw.

2. The press-fitted injector copper sleeve device according to claim 1, characterized in that: An annular groove is provided between the stepped guide holes of the shaft sleeve for positioning the return spring.

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