Special press-fitting device for sheet parts
By designing a special pressing device for sheet parts, using the negative pressure air circuit of the negative pressure joint and the vacuum pipeline joint, combined with the coaxial guide design of the guide bushing, the problems of easy damage and complex operation of the sheet parts during the pressing process are solved, and a high-precision, stable and efficient pressing process is achieved.
Patent Information
- Application Number
- CN202422201213.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-09-09
AI Technical Summary
Thin parts are susceptible to external vibration or magnetic factors during pressing and assembly, resulting in damage or deformation. The existing processes require multiple steps of operation and human cooperation, which has problems with precision control and low production efficiency.
A special pressing device for thin-sheet parts is designed, using a negative pressure air circuit composed of a negative pressure joint and a vacuum pipeline joint. The thin-sheet parts are picked up and pressed into the negative pressure, and the coaxial guide to the fuel injector and the thin-sheet parts are achieved through the exquisite design of the guide bushing, ensuring the pressing accuracy and stability.
It realizes stable pickup and high-precision pressing of thin-sheet parts, avoids damage and drop of parts, simplifies the operation process, reduces human resource requirements, improves production efficiency, and reaches the accuracy requirement of ±0.005mm.
Smart Images
Figure CN223000028U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of part processing, in particular to a special press-fitting device for thin sheet parts. Background Art
[0002] Thin sheet parts are widely used in the fields of machining and manufacturing. Thin sheet parts are usually used to adjust the clearance in mechanical devices to ensure the appropriate spacing between components for normal operation. Thin sheet parts can be used to compensate for the dimensional errors of one or more parts to make the components fit better. In addition, they can also be used as dampers or shock absorbers in mechanical devices to balance the load distribution and reduce vibration.
[0003] The thickness of thin sheet parts is often less than 1 mm and the mass is light, and some are even less than 0.2 g / piece. Based on the structural characteristics of such thin sheet parts, during the entire process from transfer to press-fitting into the stepped hole of the fuel injector, they are extremely vulnerable to being flipped by external vibrations or magnetism and other adverse factors, resulting in damage to the parts during the press-fitting process or falling off after deformation, leading to failure. Seriously, it can cause the loss of the basic functions of the engine.
[0004] The process of press-fitting thin sheet parts into the stepped hole of the fuel injector usually requires five steps to complete, specifically: ① The thin sheet is picked up manually; ② Manually placed on the stepped hole of the fuel injector; ③ The two are placed together in the fuel injector fixing seat; ④ Manually align the thin sheet with the stepped hole of the fuel injector before starting the press; ⑤ Release the hand to start the press to press it in. However, in the above process, the thin sheet parts have the risk of falling and skewing. Once skewed, they will be deformed or damaged during the downward pressing process; and the entire operation requires at least two operators to work together, resulting in excessive occupation of human resources. In addition, in order to ensure that the press-fitting depth requirement meets 0.15 ± 0.05 mm, it is necessary to control the slow downward pressing of a high-precision press with an accuracy of 0.005 level to meet the press-fitting requirements. This not only increases the hardware cost, but also reduces the production efficiency during the slow press-fitting production process.
[0005] Therefore, it is urgent to develop a special press-fitting device for thin sheet parts that can integrate the above process flow to ensure the quality of press-fitting thin sheet parts into the fuel injector and improve the production efficiency of press-fitting thin sheet parts. Summary of the Utility Model
[0006] The purpose of the utility model is to provide a special press-fitting device for thin sheet parts to ensure the quality of press-fitting thin sheet parts into the fuel injector and improve the production efficiency.
[0007] The purpose of the utility model can be realized by the following technical solutions:
[0008] A special press-fitting device for thin sheet parts, which is used to press thin sheet parts into an injector. The press-fitting device includes a mounting base, a vacuum pipeline joint and a press-fitting assembly arranged on the mounting base. A negative pressure cavity communicated with the vacuum pipeline joint is arranged in the press-fitting assembly;
[0009] The press-fitting assembly includes a vertically arranged press head and a press rod coaxially arranged with and penetrating through the press head. A negative pressure joint is arranged at the bottom of the press rod, and a first ventilation hole communicated with the negative pressure cavity is arranged on the contact surface between the negative pressure joint and the thin sheet part;
[0010] A guiding bushing is sleeved outside the press rod in a sliding manner, and a housing connected to the mounting base is arranged outside the press-fitting assembly and the guiding bushing. A first gap is left between the top surface of the guiding bushing and the bottom surface of the press head. The bottom of the guiding bushing can be docked with the injector. After docking, a second gap adapted to the thickness of the thin sheet part is left between the top surface of the injector and the contact surface of the negative pressure joint. The thickness of the second gap is less than that of the first gap, and the net difference between the two is the press-fitting depth of the thin sheet part pressed into the injector.
[0011] Further, a plurality of first ventilation holes are uniformly arranged in a ring on the contact surface between the negative pressure joint and the thin sheet part.
[0012] Further, second ventilation holes corresponding to the first ventilation holes one by one are arranged at the bottom of the negative pressure cavity, and the first ventilation holes and the corresponding second ventilation holes are communicated through pipelines.
[0013] Further, the press-fitting assembly, the negative pressure cavity, the negative pressure joint and the guiding bushing are all coaxially arranged to ensure that the processes of negative pressure picking up and pressing the thin sheet part are all carried out on the same axis.
[0014] Further, the press head and the press rod are integrally formed, and a through negative pressure cavity is arranged inside.
[0015] Further, the guiding bushing includes a first annular part, a second annular part and a third annular part connected in sequence from top to bottom.
[0016] Further, the outer diameter of the second annular part is larger than that of the first annular part and the third annular part, and a first platform is formed between the second annular part and the third annular part.
[0017] Further, a clamping block capable of being clamped with the first platform is arranged at the bottom of the housing.
[0018] Furthermore, when the first platform contacts the clamping block of the housing, a first gap is left between the top surface of the first annular part and the bottom surface of the press head, and the first gap is the limiting distance for the guiding bushing to slide during press-fitting.
[0019] Furthermore, a first chamfer for guiding and correcting the central position of the fuel injector is provided at the bottom of the third annular portion, which can guide and correct the central position of the fuel injector and correct its coaxiality with the thin sheet part.
[0020] Furthermore, the third annular portion is provided with a second platform capable of abutting against the upper end surface of the fuel injector.
[0021] Furthermore, when the fuel injector abuts against the second platform, a second gap is left between the upper end surface of the fuel injector and the negative pressure joint.
[0022] Furthermore, a second chamfer for guiding and correcting the central position of the thin sheet part is formed between the second platform and the vertical inner wall of the third annular portion, which guides and corrects the central position of the thin sheet part, enabling the thin sheet part to be better picked up by the negative pressure joint.
[0023] Furthermore, the cover is installed at the bottom of the mounting seat through bolts, which increases the overall stability during the pressing process.
[0024] Compared with the prior art, the utility model has the following beneficial effects:
[0025] (1) The utility model picks up the thin sheet part by negative pressure through the negative pressure joint, and with the cooperation of an external press, the picked-up thin sheet part is successfully pressed into the fuel injector to a certain depth. The stable pressing of the thin sheet part can be realized through the function integration of a pressing device, ensuring the quality and production efficiency of pressing the thin sheet part into the fuel injector.
[0026] (2) The negative pressure air path composed of multiple ventilation holes, a negative pressure cavity and a vacuum pipeline joint in the utility model can stably pick up the thin sheet part through negative pressure, and will not flip under the influence of external vibrations or magnetism and other adverse factors, avoiding part damage or dropping during the pressing process.
[0027] (3) Through the ingenious design of the guiding bushing in the utility model, the central position of the fuel injector can be guided and corrected through the auxiliary guiding and correcting effect of two chamfers, the coaxiality between it and the thin round sheet is corrected, and the central position of the thin sheet part is guided and corrected, avoiding skew during the pressing process and improving the pressing accuracy.
[0028] (4) Through the ingenious design of the guiding bushing in the pressing device of the utility model, the depth is controlled by dead limit. On the premise of having no special requirements for the press, the accuracy of ±0.005 mm can be easily achieved, which is one order of magnitude higher than the tolerance of ±0.05 mm required by the drawing.
[0029] (5) During the entire press-fitting process of the press-fitting device of the present utility model, only one worker is required to load the fuel injector. At the same time, due to the highly integrated design, the floor space occupation and the investment in high-precision hardware equipment are reduced. The automated method shortens the single-piece cycle time from 10 s to 5.3 s, saving one worker and reducing the labor intensity and the requirements for manual skills. Description of the Drawings
[0030] Figure 1 It is a schematic diagram of the overall structure of the press-fitting device of the present utility model.
[0031] Figure 2 It is a cross-sectional view of the press-fitting device of the present utility model.
[0032] Figure 3 It is a schematic diagram of the first ventilation hole in Embodiment 2 of the present utility model.
[0033] Figure 4 It is a schematic diagram of the negative pressure air path in Embodiment 2 of the present utility model.
[0034] Figure 5 It is a schematic diagram of the guide bushing in Embodiment 3 of the present utility model.
[0035] Figure 6 It is a schematic diagram of the press-fitting process in Embodiment 3 of the present utility model.
[0036] Figure 7 It is the final effect diagram after the thin sheet part is pressed into the fuel injector in Embodiment 3 of the present utility model.
[0037] Figure 8 It is a schematic diagram of the guide bushing in Embodiment 4 of the present utility model.
[0038] Figure 9 It is a schematic diagram of the thin sheet part in Embodiment 5 of the present utility model.
[0039] Figure 10 It is a schematic diagram of the first gap and the second gap in Embodiment 5 of the present utility model.
[0040] Figure 11 It is a schematic diagram of the press-in depth in Embodiment 5 of the present utility model.
[0041] Explanation of the marks in the figure:
[0042] 1 - Mounting base;
[0043] 2 - Vacuum pipeline joint;
[0044] 3 - Press-fitting assembly, 31 - Negative pressure cavity, 311 - Second ventilation hole, 32 - Press head, 33 - Press rod;
[0045] 4 - Negative pressure joint, 41 - First ventilation hole;
[0046] 5 - Guide bushing, 51 - First annular part, 52 - Second annular part, 521 - First platform, 53 - Third annular part, 531 - First chamfer, 532 - Second platform, 533 - Second chamfer;
[0047] 6 - Housing, 61 - Clamping block;
[0048] 7 - Thin - sheet part;
[0049] 8 - Fuel injector. Specific embodiments
[0050] The present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present utility model, and gives detailed implementation manners and specific operation processes, but the protection scope of the present utility model is not limited to the following embodiments.
[0051] In the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present utility model; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.
[0052] It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0053] Embodiment 1:
[0054] A special press - fitting device for thin - sheet parts, used to press the thin - sheet part 7 into the fuel injector 8. As Figure 1-2 shown, the press - fitting device includes a mounting base 1, a vacuum pipeline joint 2 provided on the mounting base 1, and a press - fitting assembly 3. A negative - pressure cavity 31 communicating with the vacuum pipeline joint 2 is provided inside the press - fitting assembly 3.
[0055] The press-fitting assembly 3 includes a vertically arranged press head 32 and a press rod 33 that is coaxially arranged with and penetrates the press head 32; a negative pressure connector 4 is provided at the bottom of the press rod 33, and a first ventilation hole 41 that can communicate with the negative pressure cavity 31 is provided on the contact surface between the negative pressure connector 4 and the thin sheet part 7.
[0056] A guiding bushing 5 is slidably sleeved outside the press rod 33, and a housing 6 connected to the mounting base 1 is provided outside the press-fitting assembly 3 and the guiding bushing 5. A first gap is left between the top surface of the guiding bushing 5 and the bottom surface of the press head 32. The bottom of the guiding bushing 5 can be docked with the fuel injector 8, and a second gap adapted to the thickness of the thin sheet part 7 is left between the top surface of the fuel injector 8 and the contact surface of the negative pressure connector 4 after docking. The thickness of the second gap is less than that of the first gap, and the net difference between the two is the press-in depth of the thin sheet part 7 pressed into the fuel injector 8.
[0057] The negative pressure connector 4 in this embodiment can not only play the role of picking up the thin sheet part 7 by negative pressure, but also, with the cooperation of an external press, successfully press the picked-up thin sheet part 7 into the fuel injector 8 to a certain depth, and the stable press-fitting of the thin sheet part 7 can be realized through the function integration of one device.
[0058] Embodiment 2:
[0059] A special press-fitting device for thin sheet parts is used to press the thin sheet part 7 into the fuel injector 8. The press-fitting device includes a mounting base 1, a vacuum pipeline connector 2 provided on the mounting base 1, and a press-fitting assembly 3. A negative pressure cavity 31 communicated with the vacuum pipeline connector 2 is provided inside the press-fitting assembly 3. The vacuum pipeline connector 2 in this embodiment is connected to a vacuum pump for providing negative pressure power.
[0060] The difference from Embodiment 1 is that, as Figure 3-4 shown, the press-fitting assembly 3 in this embodiment includes a vertically arranged press head 32 and a press rod 33 that is coaxially arranged with and penetrates the press head 32; a negative pressure connector 4 is provided at the bottom of the press rod 33, and a plurality of first ventilation holes 41 are evenly arranged in a ring on the contact surface between the negative pressure connector 4 and the thin sheet part 7. A second ventilation hole 311 corresponding to each first ventilation hole 41 is provided at the bottom of the negative pressure cavity 31, and the first ventilation hole 41 and the corresponding second ventilation hole 311 are connected through a pipeline to form a complete negative pressure air path from the negative pressure connector 4 to the negative pressure cavity 31 to the vacuum pipeline connector 2.
[0061] Embodiment 3:
[0062] A special press-fitting device for thin sheet parts is used to press the thin sheet part 7 into the fuel injector 8. The press-fitting device includes a mounting base 1, a vacuum pipeline joint 2 provided on the mounting base 1, and a press-fitting assembly 3. A negative pressure cavity 31 communicated with the vacuum pipeline joint 2 is arranged in the press-fitting assembly 3. The press-fitting assembly 3 includes a vertically arranged press head 32 and a press rod 33 arranged coaxially with the press head 32 and penetrating through. A negative pressure joint 4 is provided at the bottom of the press rod 33, and a first ventilation hole 41 capable of communicating with the negative pressure cavity 31 is provided on the contact surface of the negative pressure joint 4 with the thin sheet part 7.
[0063] As Figure 5 shown, a guiding bush 5 is sleeved outside the press rod 33 in a sliding manner, and a housing 6 connected to the mounting base 1 is provided outside the press-fitting assembly 3 and the guiding bush 5. The housing 6 is installed at the bottom of the mounting base 1 through bolts. The press-fitting assembly 3, the negative pressure cavity 31, the negative pressure joint 4, and the guiding bush 5 are all arranged coaxially to ensure that the processes of negative pressure picking-up and pressing the thin sheet part 7 are carried out on the same axis.
[0064] The guiding bush 5 includes a first annular part 51, a second annular part 52, and a third annular part 53 connected in sequence from top to bottom. The outer diameter of the second annular part 52 is larger than that of the first annular part 51 and the third annular part 53. A first platform 521 is formed between the second annular part 52 and the third annular part 53, and a clamping block 61 capable of being clamped with the first platform 521 is provided at the bottom of the housing 6. When the first platform 521 contacts the clamping block 61 of the housing 6 (i.e., in the natural state before starting press-fitting), a first gap is left between the top surface of the first annular part 51 and the bottom surface of the press head 32. The first gap is the limiting distance for the guiding bush 5 to slide during press-fitting. The bottom of the guiding bush 5 can be docked with the fuel injector 8. After docking, a second gap adapted to the thickness of the thin sheet part 7 is left between the top surface of the fuel injector 8 and the contact surface of the negative pressure joint 4. The thickness of the second gap is smaller than that of the first gap, and the net difference between the two is the press-fitting depth of the thin sheet part 7 into the fuel injector 8.
[0065] As Figure 6-7 shown, when the bottom of the guiding bush 5 can be aligned with the fuel injector 8, the external press drives the entire press-fitting device to descend, and the first gap between the top surface of the first annular part 51 and the bottom surface of the press head 32 gradually decreases. The thin sheet part 7 placed on the upper end surface of the fuel injector 8 gradually approaches the negative pressure joint 4 and is picked up by negative pressure. As the press continues to apply pressure, the top surface of the first annular part 51 abuts against the bottom surface of the press head 32. Since the thickness of the second gap is smaller than that of the first gap, the thin sheet part 7 at this time will be pressed into the fuel injector 8, and the press-fitting depth is the net difference between the second gap and the first gap.
[0066] Example 4:
[0067] A special press-fitting device for thin sheet parts is used to press the thin sheet part 7 into the fuel injector 8. Different from Embodiment 3, in order to achieve automatic alignment of the thin sheet part 7 and the fuel injector 8 during the downward pressing process, a first chamfer 531 for aligning the central position of the fuel injector 8 is provided at the bottom of the third annular part 53. The third annular part 53 is provided with a second platform 532 that can abut against the upper end surface of the fuel injector 8. When the fuel injector 8 abuts against the second platform 532, a second gap is left between the upper end surface of the fuel injector 8 and the negative pressure joint 4. A second chamfer 533 for aligning the central position of the thin sheet part 7 is formed between the second platform 532 and the vertical inner wall of the third annular part 53.
[0068] As Figure 8 shown, during the downward pressing process, the fuel injector 8 first contacts the first chamfer 531 to align the central position of the fuel injector 8 and correct its coaxiality with the thin sheet part 7. Continuing to press down, the negative pressure joint 4 picks up the thin sheet part 7. After passing through the second chamfer 533, the central position of the thin sheet part 7 is aligned, enabling the thin sheet part 7 to be better picked up by the negative pressure joint 4.
[0069] Embodiment 5:
[0070] A special press-fitting device for thin sheet parts is used to press the thin sheet part 7 into the fuel injector 8. As Figure 9 shown, the thin sheet part 7 in this embodiment presents a thin circular disc shape and needs to be pressed into the stepped hole of the fuel injector 8, and the required pressing depth is 0.15 ± 0.05 mm. The thickness of the thin sheet part is 0.75 ± 0.05 mm, the diameter is φ6.235 mm, and the weight is 0.18 g / piece.
[0071] The press-fitting process of the thin sheet part 7 in this embodiment includes the following three aspects:
[0072] (1) Automatically pick up the thin sheet part 7 and automatically position it:
[0073] The parts are picked up by negative pressure, and the negative pressure air path is shown in Figure 4 . Specifically, the negative pressure joint 4 sucks up the thin sheet part 7 by means of vacuum negative pressure. Six first ventilation holes 41 are provided on the contact surface between the negative pressure joint 4 and the thin sheet part 7. The first ventilation holes 41 are connected to the main negative pressure air path of the vacuum pipeline joint 2 through the negative pressure cavity 31. After passing through the second chamfer 533 of the guide bushing 5, the central position of the thin sheet part 7 can be aligned during the suction process. The vacuum negative pressure value at the vacuum pipeline joint 2 is detected to judge whether there is air leakage. If there is no air leakage, at this time, since the six first ventilation holes 41 are blocked by the thin sheet part 7 that has been sucked in place, the vacuum negative pressure value reaches the maximum, and it is determined that the thin sheet part 7 has been sucked in place and the central positioning is completed synchronously. If there is air leakage, it means that the thin sheet part 7 does not fit flatly with the negative pressure joint 4, and an alarm will be prompted at this time until it is fully fitted and the negative pressure is the maximum.
[0074] (2) Guide bush for aligning the fuel injector:
[0075] After confirming that the thin sheet part 7 is in place, the press drives the entire press-fitting device to descend. During this process, the first chamfer 531 first contacts the outer circle of the fuel injector 8, which can align the central position of the fuel injector 8 and correct its coaxiality with the thin sheet part 7. Then continue to press down until the end of the fuel injector 8 contacts the second platform 532. At this time, push the guide bush 5 upward until its top contacts the first platform 521, and all strokes are completed. Since the depth is controlled by a dead stop, on the premise that there are no special requirements for the press, an accuracy of ±0.005 mm can be easily achieved, which is one order of magnitude higher than the ±0.05 mm tolerance required by the drawing.
[0076] (3) Control of the press-fitting depth:
[0077] As Figure 10-11 shown, the press-fitting depth is mechanically guaranteed by the fixture. When designing, a 1 mm gap (i.e., the first gap) is reserved between the first platform 521 and the top of the guide bush 5, and the end face of the negative pressure joint 4 is 0.85 mm higher than the upper end face of the fuel injector (i.e., the second gap). When all the upper gaps are compressed, the negative pressure joint 4 will move downward by 1 mm, eliminating the previously higher 0.85 mm, and just pressing down the thin sheet part 7 by 0.15 mm (the press-fitting depth), that is, 0.15 mm lower than the upper end face of the fuel injector 8, and successfully pressing the thin sheet part 7 into the fuel injector 8.
[0078] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the utility model. Obviously, those who are familiar with the technology in this field can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present utility model is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present utility model according to the disclosure of the present utility model should be within the protection scope of the present utility model.
Claims
1. A special press-fitting device for thin-sheet parts, used for pressing thin-sheet parts (7) into fuel injectors (8), characterized in that: The press-fit device comprises a mounting seat (1), a vacuum pipeline joint (2) and a press-fit assembly (3) arranged on the mounting seat (1); a negative pressure cavity (31) communicating with the vacuum pipeline joint (2) is arranged in the press-fit assembly (3); The press-fitting assembly (3) comprises a vertically arranged pressure head (32) and a pressure rod (33) coaxially arranged with and penetrating the pressure head (32); a negative pressure joint (4) is provided at the bottom of the pressure rod (33); a first vent hole (41) capable of communicating with the negative pressure cavity (31) is provided on the contact surface between the negative pressure joint (4) and the sheet part (7); The outer sliding sleeve of the pressure rod (33) is provided with a guide bushing (5), and the outer cover of the press-fitting assembly (3) and the guide bushing (5) is provided with a cover shell (6) connected to the mounting seat (1); a first gap is left between the top surface of the guide bushing (5) and the bottom surface of the pressure head (32); the bottom of the guide bushing (5) can be docked with the injector (8), and after docking, a second gap matching the thickness of the thin-film component (7) is left between the top surface of the injector (8) and the contact surface of the negative pressure joint (4); the thickness of the second gap is smaller than the first gap, and the net difference between the two is the pressing depth of the thin-film component (7) pressed into the injector (8).
2. A special press-fitting device for thin-sheet parts according to claim 1, characterized in that: A plurality of first vent holes (41) are evenly arranged on the contact surface between the negative pressure joint (4) and the thin sheet part (7).
3. A special press-fitting device for thin-sheet parts according to claim 2, characterized in that: The bottom of the negative pressure cavity (31) is provided with second ventilation holes (311) corresponding one to one with the first ventilation holes (41), and the first ventilation holes (41) are connected to the corresponding second ventilation holes (311) via a pipeline.
4. A special press-fitting device for thin-sheet parts according to claim 1, characterized in that: The press-fit assembly (3), the negative pressure cavity (31), the negative pressure joint (4) and the guide bushing (5) are all coaxially arranged.
5. A special press-fitting device for thin-sheet parts according to claim 1, characterized in that: The guide bushing (5) comprises a first annular portion (51), a second annular portion (52) and a third annular portion (53) which are sequentially connected from top to bottom; The outer diameter of the second annular portion (52) is greater than that of the first annular portion (51) and the third annular portion (53), and a first platform (521) is formed between the second annular portion (52) and the third annular portion (53).
6. A special press-fitting device for thin-sheet parts according to claim 5, characterized in that: The bottom of the cover shell (6) is provided with a clamping block (61) capable of clamping with the first platform (521); When the first platform (521) contacts the clamping block (61) of the housing (6), a first gap is left between the top surface of the first annular portion (51) and the bottom surface of the pressure head (32).
7. A special press-fitting device for thin-sheet parts according to claim 5, characterized in that: The bottom of the third annular portion (53) is provided with a first chamfer (531) for guiding the center position of the fuel injector (8).
8. A special press-fitting device for thin-sheet parts according to claim 5, characterized in that: The third annular portion (53) is provided with a second platform (532) capable of abutting against the upper end surface of the fuel injector (8); When the fuel injector (8) abuts against the second platform (532), a second gap is left between the upper end surface of the fuel injector (8) and the negative pressure joint (4).
9. A special press-fitting device for thin-sheet parts according to claim 8, characterized in that: A second chamfer (533) for correcting the center position of the sheet part (7) is formed between the second platform (532) and the vertical inner wall of the third annular portion (53).
10. A special press-fitting device for thin-sheet parts according to claim 1, characterized in that: The cover shell (6) is mounted on the bottom of the mounting seat (1) by means of bolts.