A kind of oil inlet cap press fitting fixture

Abstract

The present invention discloses an oil inlet cap press-fitting jig, comprising a bottom plate, a base arranged on the surface of the bottom plate, a mounting tube vertically erected on the surface of the base and mounting a mounting bracket through the top end face, a positioning ring groove opened on the top end face of the mounting tube and used to position the outer circle of the bottom shell of the mounting bracket, a lifting shaft vertically lifted and inserted in the positioning ring groove and used to position the nested mounting bracket, a vertical plate vertically erected on the surface of the bottom plate and used to position the seat edge plane close to the mounting bracket, a positioning ring sleeved on the top end of the lifting shaft and used to position the bottom outer circle of the nested oil inlet cap, an arched column vertically erected on the top end face of the lifting shaft and used to position the missing edge plane close to the bottom outer circle, and a pressure head vertically lifted and suspended above the mounting tube and used to press the oil inlet cap into the mounting bracket, wherein the chord side plane of the arched column is perpendicular to the surface of the vertical plate. The present invention can improve the assembly accuracy of the oil inlet cap and the mounting bracket and meet the assembly positioning conditions.

Description

Technical Field

[0001] The invention relates to the technical field of fuel pumps, and in particular to a fuel inlet cap press-fitting jig. Background Art

[0002] During the assembly process of the fuel pump, it is necessary to smoothly complete the assembly and assembly of multiple related components in sequence according to the assembly process.

[0003] The fuel pump has many components, among which the mounting bracket a and the fuel inlet cap b require high assembly accuracy. Figure 1 As shown, the mounting bracket a is cylindrical, with a bottom shell outer circle a1 at one end, and a positioning seat is installed on the outer wall of the circumference. The positioning seat is triangular and has a seat edge plane a2. The oil inlet cover b is bowl-shaped, with a bottom outer circle b1, and an oil inlet is opened at the center of the bottom outer circle b1. The bottom outer circle b1 is specifically a non-full circle with a missing arc, that is, there is a missing edge plane b2 in the circle. Figure 2 As shown, during assembly, the oil inlet cap b needs to be press-fitted into the inner end surface of the bottom outer circle a1 of the mounting bracket a to achieve a press-fit connection, while ensuring that the bottom outer circle b1 of the oil inlet cap b is exposed outside the mounting bracket a.

[0004] During the assembly process of the mounting bracket and the oil inlet cap, due to the high-precision assembly requirements, two assembly positioning conditions need to be guaranteed: one is the coaxiality of the oil inlet cap and the mounting bracket, and the other is that the missing edge plane of the oil inlet cap and the seat edge plane of the mounting bracket remain perpendicular after assembly.

[0005] In the prior art, the press-fitting operation of the oil inlet cap in the mounting bracket is mainly completed manually with the help of tools. For example, after the operator roughly aligns the oil inlet cap and the mounting bracket with the naked eye, the oil inlet cap is inserted into the mounting bracket, and then the oil inlet cap is pressed to the depth of the mounting bracket by a piston and other components until the oil inlet cap reaches the inner end surface of the bottom outer circle of the mounting bracket, and then pressurized for a period of time to complete the press-fit connection. However, during the press-fitting stroke of the oil inlet cap in the mounting bracket, the oil inlet cap is easily deflected due to the uneven force applied by the operator, and the arc surface of the oil inlet cap may not be able to press the inner end surface of the mounting bracket positively. At the same time, the coaxiality between the oil inlet cap and the mounting bracket cannot be guaranteed. In addition, due to the field of vision and other factors, the operator may easily cause the missing edge plane on the oil inlet cap to rotate and deviate during press-fitting, which results in the missing edge plane being unable to remain perpendicular to the seat edge plane of the mounting bracket after assembly.

[0006] Therefore, how to improve the assembly accuracy of the oil inlet cap and the mounting bracket and meet the assembly positioning conditions on the basis of realizing the assembly of the oil inlet cap and the mounting bracket is a technical problem faced by those skilled in the art. Summary of the invention

[0007] The object of the present invention is to provide an oil inlet cap press-fitting jig, which can improve the assembly accuracy of the oil inlet cap and the mounting bracket on the basis of realizing the assembly of the oil inlet cap and the mounting bracket, and meet the assembly positioning conditions.

[0008] In order to solve the above technical problems, the present invention provides an oil inlet cover pressing fixture, comprising a base plate, a base arranged on the surface of the base plate, a mounting tube vertically erected on the surface of the base and mounting a mounting bracket through the top end face, a positioning ring groove opened on the top end face of the mounting tube and used to position the outer circle of the bottom shell of the mounting bracket, a lifting shaft that can be vertically lifted and inserted in the positioning ring groove and used to position the nested mounting bracket, a vertical plate vertically erected on the surface of the base plate and used to position the seat edge plane tightly against the mounting bracket, a positioning ring sleeved on the top end of the lifting shaft and used to position the bottom outer circle of the nested oil inlet cover, a bow-shaped column vertically erected on the top end face of the lifting shaft and used to position the missing edge plane tightly against the bottom outer circle, and a pressing head that can be vertically lifted and suspended above the mounting tube and opposite to the lifting shaft and used to press the oil inlet cover into the mounting bracket, the chord side plane of the bow-shaped column is perpendicular to the surface of the vertical plate.

[0009] Preferably, it further comprises a guide rod vertically arranged in the installation tube, and a guide groove for clamping the guide rod to cooperate with the guide is opened on the outer circumferential surface of the lifting shaft.

[0010] Preferably, a limiting ring is sleeved on the outer circumferential surface of the lifting shaft, the top end surface of the limiting ring is used to abut against the bottom end surface of the positioning ring groove to limit the rising stroke of the lifting shaft, and the guide groove is opened on the outer edge of the limiting ring.

[0011] Preferably, an elastic member is connected between the bottom end surface of the lifting shaft and the surface of the base, so as to enable the lifting shaft to rise and reset after the pressure head presses the oil inlet cover into place.

[0012] Preferably, a bottom end surface of the lifting shaft is provided with an accommodating cavity extending along its axial direction, and the elastic member is a spring distributed in the accommodating cavity along the axial direction.

[0013] Preferably, the inner diameter of the positioning ring is interference-fitted with the outer circumferential surface of the top step of the lifting shaft, and the outer diameter of the positioning ring is equal to the outer diameter of the lifting shaft.

[0014] Preferably, two arched columns are distributed on the top end surface of the lifting shaft, and each of the arched columns is located at the radial ends of the top end surface of the lifting shaft.

[0015] Preferably, a receiving groove protruding from the bottom end surface of the oil inlet cover is provided at the center of the top end surface of the lifting shaft.

[0016] Preferably, the outer diameter of the pressure head is 1% to 3% smaller than the inner diameter of the mounting bracket, and the circumferential surface of the pressure head is smooth.

[0017] Preferably, the circumferential surfaces of the lifting shaft and the positioning ring are smooth.

[0018] The oil inlet cover press-fitting fixture provided by the present invention mainly includes a bottom plate, a base, a mounting tube, a positioning ring groove, a lifting shaft, a vertical plate, a positioning ring, an arched column and a pressure head. Among them, the bottom plate is the underlying structure of the press-fitting fixture, which is mainly used to install the remaining parts and provide a working environment for the press-fitting operation of the mounting bracket and the oil inlet cover. The base is arranged on the surface of the bottom plate, and the mounting tube is arranged on the surface of the base, and is vertically arranged and extended to a certain height in the vertical direction, and is mainly used to install the mounting bracket through its top end face, so that the bottom surface of the positioning seat of the mounting bracket is pressed against the top end face of the mounting tube. The positioning ring groove is provided on the top end face of the mounting tube, and is mainly used to cooperate with the outer circle of the bottom shell at the bottom of the mounting bracket, so that the outer circle of the bottom shell is installed in the positioning ring groove to realize the rapid positioning and installation of the mounting bracket on the mounting tube. The lifting shaft is vertically inserted in the positioning ring groove, and can perform vertical lifting movement in the positioning ring groove. It is mainly used to cooperate with the inner wall of the mounting bracket, so that the mounting bracket is sleeved on the circumferential surface of the lifting shaft to realize the positioning and installation of the mounting bracket. The vertical plate is vertically erected on the surface of the bottom plate and extends vertically to a certain height. It is mainly used to fit tightly with the seat edge plane on the mounting bracket to achieve circumferential positioning of the mounting bracket. The positioning ring is sleeved on the top position of the lifting shaft, and is mainly used to cooperate with the bottom outer circle of the oil inlet cover, so that the bottom outer circle of the oil inlet cover is nested in the positioning ring, and at the same time, the top end face of the lifting shaft and the bottom end face of the oil inlet cover are abutted to jointly achieve the axial positioning of the oil inlet cover. The bow-shaped column is vertically erected on the top end face of the lifting shaft, and its cross-sectional shape is bow-shaped. It is mainly used to use its chord side plane to fit tightly with the missing edge plane on the bottom outer circle of the oil inlet cover to achieve circumferential positioning of the oil inlet cover and prevent the oil inlet cover from rotating in the positioning ring. In addition, the chord side plane of the bow-shaped column is also perpendicular to the surface of the vertical plate. The pressure head is suspended above the mounting tube and aligned with the lifting shaft, capable of vertical lifting and lowering motion. It is mainly used to press the inner arc surface of the oil inlet cover during the descending stroke and press the oil inlet cover into the mounting bracket until it reaches the inner end surface of the bottom outer circle of the mounting bracket to complete the pressing operation.

[0019] In this way, the oil inlet cover press-fitting jig provided by the present invention realizes the positioning and installation of the installation bracket on the installation tube by nesting the lifting shaft with the installation bracket, installing the positioning ring groove with the outer circle of the bottom shell, and the vertical plate with the seat edge plane. At the same time, the positioning and installation of the oil inlet cover on the lifting shaft is realized by nesting the positioning ring with the oil inlet cover and the arched column with the missing edge plane. During the press-fitting process of the pressure head, since the positioning ring is coaxially arranged with the lifting shaft, and the lifting shaft is coaxially nested with the installation bracket, the oil inlet cover only performs vertical linear motion under the vertical pressure of the pressure head, ensuring the coaxial assembly requirements of the oil inlet cover and the installation bracket; at the same time, since the chord side plane of the arched column is perpendicular to the surface of the vertical plate, compared with the missing edge plane of the oil inlet cover and the seat edge plane of the installation bracket, and in the press-fitting stroke of the oil inlet cover, the oil inlet cover cannot rotate, and the installation bracket cannot rotate, so it can be ensured that the missing edge plane of the oil inlet cover and the seat edge plane of the installation bracket remain perpendicular after assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 The figure is a schematic diagram of the installation process of the mounting bracket and the oil inlet cap in the prior art.

[0022] Figure 2 It is a structural cross-sectional view of the mounting bracket and the oil inlet cover after being assembled in the prior art.

[0023] Figure 3 The present invention provides a schematic diagram of the overall structure of a specific implementation method.

[0024] Figure 4 for Figure 3 sectional view of .

[0025] Figure 5 It is a structural diagram of the pressure head pressing the oil inlet cap into the bottom end of the mounting bracket.

[0026] Figure 6 It is a schematic diagram of the exploded structure of the lifting shaft and the positioning ring.

[0027] Figure 7 It is a schematic diagram of the installation structure of the lifting shaft and the positioning ring.

[0028] Figure 8 It is a structural schematic diagram showing that the mounting bracket is lifted up by the elastic member after the oil inlet cap is pressed and installed.

[0029] in, Figure 1 — Figure 8 middle:

[0030] Mounting bracket—a, outer circle of bottom shell—a1, seat edge plane—a2, oil inlet cover—b, bottom outer circle—b1, missing edge plane—b2;

[0031] Bottom plate—1, mounting cylinder—2, lifting shaft—3, vertical plate—4, positioning ring—5, pressure head—6, guide rod—7, elastic member—8, base—9;

[0032] Positioning ring groove 21, bow-shaped column 31, guide groove 32, limiting ring 33, accommodating cavity 34, accommodating groove 35. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Please refer to Figure 3 , Figure 4 , Figure 3 This is a schematic diagram of the overall structure of a specific implementation method provided by the present invention. Figure 4 for Figure 3 sectional view of .

[0035] In a specific embodiment provided by the present invention, the oil inlet cover pressing fixture mainly includes a base plate 1, a mounting cylinder 2, a positioning ring groove 21, a lifting shaft 3, a vertical plate 4, a positioning ring 5, a bow-shaped column 31 and a pressure head 6, and a base 9.

[0036] Among them, the bottom plate 1 is the bottom structure of the press-fitting fixture, which is mainly used to install other parts and provide a working environment for the press-fitting operation of the mounting bracket a and the oil inlet cover b.

[0037] The base 9 is arranged on the surface of the base plate 1, and the mounting tube 2 is arranged on the surface of the base 9, and is erected in the vertical direction and extends to a certain height, mainly used for installing the mounting bracket a through its top end face, so that the bottom surface of the positioning seat of the mounting bracket a is pressed against the top end face of the mounting tube 2.

[0038] The positioning ring groove 21 is provided on the top end surface of the mounting tube 2 and is mainly used to cooperate with the outer circle a1 of the bottom shell at the bottom of the mounting bracket a, so that the outer circle a1 of the bottom shell is installed in the positioning ring groove 21 to realize the rapid positioning and installation of the mounting bracket a on the mounting tube 2.

[0039] The lifting shaft 3 is vertically inserted in the positioning ring groove 21, and can perform vertical lifting movement in the positioning ring groove 21. It is mainly used to cooperate with the inner wall of the mounting bracket a for installation, so that the mounting bracket a is sleeved on the circumferential surface of the lifting shaft 3 to realize the positioning installation of the mounting bracket a.

[0040] The vertical plate 4 is vertically arranged on the surface of the bottom plate 1 and vertically extends to a certain height, and is mainly used to be in close contact with the seat edge plane a2 on the mounting bracket a to achieve the circumferential positioning of the mounting bracket a.

[0041] The positioning ring 5 is sleeved on the top end of the lifting shaft 3, and is mainly used to cooperate with the bottom outer circle b1 of the oil inlet cover b, so that the bottom outer circle b1 of the oil inlet cover b is nested in the positioning ring 5, and at the same time, the top end face of the lifting shaft 3 and the bottom end face of the oil inlet cover b are abutted to jointly realize the axial positioning of the oil inlet cover b.

[0042] The bow-shaped column 31 is vertically arranged on the top end face of the lifting shaft 3, and its cross-sectional shape is bow-shaped. It is mainly used to utilize its chord side plane to be in close contact with the missing edge plane b2 on the bottom outer circle b1 of the oil inlet cover b to achieve circumferential positioning of the oil inlet cover b and prevent the oil inlet cover b from rotating in the positioning ring 5. In addition, the chord side plane of the bow-shaped column 31 also remains perpendicular to the surface of the vertical plate 4.

[0043] The pressure head 6 is suspended above the mounting tube 2 and aligned with the lifting shaft 3, and can perform vertical lifting motion. It is mainly used to press the inner arc surface of the oil inlet cover b during the descending stroke, and press the oil inlet cover b into the mounting bracket a until it reaches the inner end surface of the bottom outer circle b1 of the mounting bracket a, completing the press-fitting operation. The power source of the pressure head 6 can be a drive cylinder component, a motor component, etc.

[0044] In this way, the oil inlet cover pressing fixture provided in this embodiment realizes the positioning and installation of the mounting bracket a on the mounting tube 2 through the nesting of the lifting shaft 3 on the mounting bracket a, the installation of the positioning ring groove 21 on the outer circle a1 of the bottom shell, and the close contact of the vertical plate 4 to the seat edge plane a2. At the same time, the positioning and installation of the oil inlet cover b on the lifting shaft 3 is realized by the nesting installation of the positioning ring 5 on the oil inlet cover b and the close contact of the arched column 31 on the missing edge plane b2.

[0045] like Figure 5 As shown, Figure 5 It is a structural schematic diagram of the pressure head 6 pressing the oil inlet cover b into the bottom end of the mounting bracket a.

[0046] During the press-fitting process of the pressure head 6, since the positioning ring 5 is coaxially arranged with the lifting shaft 3, and the lifting shaft 3 is coaxially nested with the mounting bracket a, the oil inlet cover b only performs vertical linear motion under the vertical pressure of the pressure head 6, thereby ensuring the coaxial assembly requirements of the oil inlet cover b and the mounting bracket a; at the same time, since the chord side plane of the bow-shaped column 31 is perpendicular to the surface of the vertical plate 4, compared with the missing edge plane b2 of the oil inlet cover b and the seat side plane a2 of the mounting bracket a, and during the press-fitting stroke of the oil inlet cover b, the oil inlet cover b cannot rotate, and the mounting bracket a cannot rotate, so it can be ensured that the missing edge plane b2 of the oil inlet cover b and the seat side plane a2 of the mounting bracket a remain perpendicular after assembly.

[0047] In order to improve the vertical lifting accuracy of the lifting shaft 3 and prevent it from shaking or deflecting during the movement, a guide rod 7 and a guide groove 32 are added in this embodiment. The guide rod 7 is vertically arranged at a specific position on the surface of the base 9, and the bottom surface of the mounting tube 2 and the surface of the base 9 are respectively provided with upper and lower guide rod holes to ensure the relative position of the guide rod 7, thereby ensuring that the lifting shaft 3 can slide coaxially and extend all the way to the bottom end surface of the positioning ring groove 21, and the lifting shaft 3 is usually located at the central axis position of the mounting tube 2, and the guide rod 7 is usually located in the outer area of ​​the mounting tube 2. The guide groove 32 is provided on the outer circumferential surface of the lifting shaft 3, mainly used to form a clamping fit with the guide rod 7, so as to form a circumferential positioning of the lifting shaft 3 and prevent the lifting shaft 3 from generating circumferential rotation when performing vertical lifting.

[0048] Generally, one guide rod 7 can be provided in the installation tube 2 , or multiple guide rods can be provided along the circumferential direction. Correspondingly, multiple guide grooves 32 can also be provided at corresponding positions of the lifting shaft 3 in the circumferential direction.

[0049] Furthermore, in order to facilitate limiting the maximum lifting stroke of the lifting shaft 3, a limit ring 33 is added in this embodiment. Specifically, the limit ring 33 is sleeved on the outer circumferential surface of the lifting shaft 3, fixedly connected thereto, and generally located at the bottom end of the lifting shaft 3. The top end surface of the limit ring 33 sleeve is mainly used to form abutment with the bottom end surface of the positioning ring groove 21, so that after the lifting shaft 3 rises a certain distance, the lifting shaft 3 is limited from continuing to rise. Correspondingly, the guide groove 32 can be opened on the outer edge of the limit ring 33.

[0050] like Figure 8 As shown, Figure 8 It is a structural schematic diagram showing that the mounting bracket a is lifted up by the elastic member 8 after the oil inlet cover b is press-fitted.

[0051] Considering that after the press-fitting operation of the mounting bracket a and the oil inlet cover b is completed, the lifting shaft 3 is pressed into the mounting tube 2 by the pressing head 6. In order to facilitate the user to remove the finished product after press-fitting from the mounting tube 2, an elastic member 8 is added in this embodiment. Specifically, the elastic member 8 is arranged in the mounting tube 2 and distributed along the vertical direction, and the top of the elastic member 8 is connected to the bottom end surface of the lifting shaft 3, and the bottom end of the elastic member 8 can be connected to the surface of the base 9. When the pressing head 6 performs the press-fitting operation, the lifting shaft 3 gradually compresses the elastic member 8, and after the press-fitting operation is completed, the pressing head 6 gradually rises. At this time, under the elastic force of the elastic member 8, the lifting shaft 3 is gradually lifted up until the lifting shaft 3 returns to its original position and extends out of the top end surface of the mounting tube 2, so that the user can take the finished product and continue to nest the next mounting bracket a.

[0052] In a preferred embodiment of the elastic member 8, the elastic member 8 is specifically a spring. Accordingly, in this embodiment, a receiving cavity 34 is also provided on the bottom end surface of the lifting shaft 3. Specifically, the receiving cavity 34 extends along the axial direction of the lifting shaft 3 and has a certain length, and the spring is installed in the receiving volume and distributed along the axial direction thereof. At this time, the top end of the spring is connected to the inner top surface of the receiving cavity 34.

[0053] In order to facilitate the stable installation of the elastic member 8 in the installation tube 2, a base 9 is added in this embodiment. Specifically, the base 9 is arranged on the surface of the bottom plate 1, and can be connected by fasteners such as bolts or a clamping structure, and the bottom end of the elastic member 8 can be connected to the installation groove provided on the base 9. Similarly, the bottom end of the installation tube 2 can also be connected to the surface of the base 9, and the installation tube 2 can be tightened by fasteners such as bolts to prevent displacement and shaking during the press-fitting process.

[0054] Of course, the elastic member 8 can be not only a spring, but also an elastic rod or the like.

[0055] like Figure 6 , Figure 7 As shown, Figure 6 It is a schematic diagram of the exploded structure of the lifting shaft and the positioning ring 5. Figure 7 It is a schematic diagram of the installation structure of the lifting shaft and the positioning ring 5.

[0056] In order to enhance the positioning stability and accuracy of the oil inlet cover b, in this embodiment, the positioning ring 5 is specifically connected with the top outer cylindrical surface of the lifting shaft 3 by an interference fit, so as to fix the positioning ring 5 at the top position of the lifting shaft 3 and ensure the coaxiality and synchronous lifting movement of the positioning ring 5 and the lifting shaft 3. At the same time, in order to avoid motion interference, the outer diameter of the positioning ring 5 is consistent with the outer diameter of the lifting shaft 3.

[0057] In a preferred embodiment of the arched pillar 31, two arched pillars 31 are generally provided on the top end surface of the lifting shaft 3, and are respectively used to fit tightly with the two missing edge planes b2 of the oil inlet cover b. At the same time, the two arched pillars 31 are respectively located at the radial ends of the top end surface of the lifting shaft 3, and are in a mutually facing state.

[0058] In addition, considering that the center area of ​​the bottom end surface of the oil inlet cover b may have a partially protruding and uneven structure due to the influence of the processing technology, in view of this, the present embodiment provides a receiving groove 35 in the center area of ​​the top end surface of the lifting shaft 3. Specifically, the specific opening position of the receiving groove 35 is directly opposite to the center area of ​​the bottom end surface of the oil inlet cover b, so that when the bottom outer circle b1 of the oil inlet cover b is installed in the positioning ring 5, the uneven structure of the bottom center of the oil inlet cover b is accommodated by the space of the receiving groove 35, thereby ensuring that the bottom outer circle of the oil inlet cover b is tightly pressed against the top end surface of the lifting shaft 3.

[0059] In a preferred embodiment of the pressure head 6, considering that the front end of the pressure head 6 usually needs to be inserted into the mounting bracket a during the press-fitting operation, in order to avoid friction loss and prevent the mounting bracket a from being subjected to forces in other directions (except vertical pressure) of the pressure head 6 during the press-fitting operation, the outer diameter of the pressure head 6 in this embodiment is slightly smaller than the inner diameter of the mounting bracket a. Generally, the outer diameter of the pressure head 6 is 1% to 3% smaller than the inner diameter of the mounting bracket a. At the same time, the circumferential surface of the pressure head 6 is a smooth surface, and even if it forms surface friction sliding with the inner wall surface of the mounting bracket a, it can greatly reduce friction and wear, and avoid damage to the oil inlet cover during the press-fitting process.

[0060] Similarly, the circumferential surfaces of the lifting shaft 3 and the positioning ring 5 in this embodiment are also smooth surfaces, so as to reduce the wear on the inner circumferential surface of the mounting bracket a and the positioning ring groove 21.

[0061] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An oil inlet cap press-fitting fixture, characterized in that: The invention comprises a bottom plate (1), a base (9) arranged on the surface of the bottom plate (1), a mounting tube (2) vertically erected on the surface of the base (9) and mounting a mounting bracket (a) through the top end surface, a positioning ring groove (21) provided on the top end surface of the mounting tube (2) and used for positioning the outer circle (a1) of the bottom shell of the mounting bracket (a), a lifting shaft (3) vertically erected on the surface of the bottom plate (1) and used for positioning the seat edge plane (a2) close to the mounting bracket (a), and a lifting shaft (4) vertically erected on the surface of the bottom plate (1) and used for positioning the seat edge plane (a2) close to the mounting bracket (a). A vertical plate (4), a positioning ring (5) sleeved on the top of the lifting shaft (3) and used to locate the bottom outer circle (b1) of the nested oil inlet cover (b), an arched column (31) vertically erected on the top end surface of the lifting shaft (3) and used to locate the missing edge plane (b2) close to the bottom outer circle (b1), and a pressing head (6) vertically suspended above the mounting tube (2) and facing the lifting shaft (3) and used to press the oil inlet cover (b) into the mounting bracket (a), wherein the chord side plane of the arched column (31) is perpendicular to the surface of the vertical plate (4); It also includes a guide rod (7) vertically arranged in the installation tube (2), and a guide groove (32) for clamping the guide rod (7) to cooperate with the guidance is opened on the outer circumferential surface of the lifting shaft (3); The inner diameter of the positioning ring (5) is interference-fitted with the outer circumferential surface of the top step of the lifting shaft (3), and the outer diameter of the positioning ring (5) is equal to the outer diameter of the lifting shaft (3).

2. The oil inlet cap press-fitting jig according to claim 1, characterized in that: A limiting ring (33) is sleeved on the outer circumferential surface of the lifting shaft (3), the top end surface of the limiting ring (33) is used to abut against the bottom end surface of the positioning ring groove (21) to limit the rising stroke of the lifting shaft (3), and the guide groove (32) is opened on the outer edge of the limiting ring (33).

3. The oil inlet cap press-fitting jig according to claim 2, characterized in that: An elastic member (8) is connected between the bottom end surface of the lifting shaft (3) and the surface of the base (9) so as to enable the lifting shaft (3) to rise and reset after the pressure head (6) presses the oil inlet cover (b) into place.

4. The oil inlet cap press-fitting jig according to claim 3, characterized in that: The bottom end surface of the lifting shaft (3) is provided with an accommodating cavity (34) extending along its axial direction, and the elastic member (8) is a spring distributed in the accommodating cavity (34) along the axial direction.

5. The oil inlet cap press-fitting jig according to claim 1, characterized in that: Two of the arched columns (31) are distributed on the top end surface of the lifting shaft (3), and each of the arched columns (31) is located at two radial ends of the top end surface of the lifting shaft (3).

6. The oil inlet cap press-fitting jig according to claim 5, characterized in that: A receiving groove (35) protruding from the bottom end surface of the oil inlet cover (b) is provided at the center of the top end surface of the lifting shaft (3).

7. The oil inlet cap press-fitting jig according to claim 1, characterized in that: The outer diameter of the pressure head (6) is 1% to 3% smaller than the inner diameter of the mounting bracket (a), and the circumferential surface of the pressure head (6) is smooth.

8. The oil inlet cap press-fitting jig according to claim 7, characterized in that: The circumferential surfaces of the lifting shaft (3) and the positioning ring (5) are smooth.

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