PTFE sheet press-fitting and sealing detection integrated device and method thereof

Abstract

A PTFE sheet press-fitting and sealing detection integrated device and method thereof belong to the technical field of sealing production. A support and a control mechanism are installed on a bench, a pressure head is installed on the control mechanism, the pressure head is slidably connected with the column of the support through the control mechanism to complete movement, a fixed base is installed in the middle of the bottom plate of the support, the fixed base is correspondingly matched with the pressure head, and a sealing detection seat is arranged in the fixed base. The method is as follows: parameter setting; workpiece assembly; press-fitting starting; coaxial positioning; press-fitting detection; sealing test; ejection and unloading; and multi-directional press fitting. The present application solves the coaxiality deviation problem caused by tolerance accumulation in the traditional process, realizes accurate regulation and control of the press-fitting interference amount, ensures batch stability, improves coaxial precision, realizes process integration and automatic sorting of unqualified products, and systematically solves the technical bottlenecks of coaxiality control difficulty, large interference amount fluctuation and detection redundancy in high-precision press fitting.

Description

Technical Field

[0001] This invention relates to an integrated device and method for PTFE sheet pressing and sealing performance testing, belonging to the field of sealing component manufacturing technology. Background Technology

[0002] Traditional external skeleton PTFE sheet pressing devices primarily rely on presser stroke control to achieve the pressing effect. However, due to the cumulative tolerance effect among the presser, external skeleton, and fixed base, it is difficult to guarantee the coaxiality control and interference stability of the external skeleton PTFE sheet during the pressing process. Specifically, the pressing amount distributed circumferentially in the radial direction exhibits significant unevenness, and this fluctuation is further aggravated with tooling wear or batch replacement, severely restricting the realization of high-precision pressing requirements.

[0003] Meanwhile, the existing technology system lacks the function of real-time detection of the sealing performance of the product after pressing, which means that the product needs to be verified by offline testing equipment after pressing, increasing the complexity of the process. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides an integrated device and method for PTFE sheet pressing and sealing performance testing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an integrated device for PTFE sheet pressing and sealing performance testing, comprising a platform, a support, a pressing head, a fixed base, a control mechanism, and a sealing test seat; the support and the control mechanism are mounted on the platform, the pressing head is mounted on the control mechanism, the pressing head moves by sliding connection between the control mechanism and the column of the support, the fixed base is mounted in the middle of the base plate of the support, the fixed base is correspondingly matched with the pressing head, and a sealing test seat is provided inside the fixed base.

[0006] The control mechanism includes a gearbox, a ball screw assembly, a stepper motor, a switch, a controller, and a pressing table. The output shaft of the stepper motor is fixedly connected to the input end of the gearbox, the output end of the gearbox is fixedly connected to the lead screw of the ball screw assembly, the lead nut of the ball screw assembly is fixedly connected to the middle of the pressing table, the two sides of the pressing table are slidably connected to the two columns of the support, and a pressing head is installed in the middle of the lower surface of the pressing table. The stepper motor is connected to the controller for signal transmission, and the controller controls the opening and closing through a switch.

[0007] The sealing detection seat includes a horizontal plate and a shaft. The shaft is fixed to the lower end of the horizontal plate. The horizontal plate is placed in the placement hole of the fixed base. The lower end of the shaft extends to the lower end of the bracket base plate. The middle part of the shaft passes through the upper surface of the horizontal plate and is provided with an air supply channel. The air supply channel is connected to an external air source. A force sensor is installed on the pressure head. The force sensor is connected to the controller for signal transmission.

[0008] The placement hole of the fixed base is a stepped hole that decreases radially from top to bottom. The lower hole of the stepped hole is used to place the skeleton, PTFE sheet and sealing test seat. The outer side of the pressure head is fitted with a sleeve with clearance, and the outer wall of the sleeve is in clearance sliding fit with the inner wall of the upper hole of the stepped hole.

[0009] The sleeve has a vertical groove on its side wall, and a screw is slidably installed in the vertical groove. The screw is threadedly fixed to the pressure head.

[0010] The inner wall of the sleeve is coated with a shape memory polymer coating, and the outer wall of the sleeve is provided with an annular heating module, which is connected to the controller for signal transmission.

[0011] The pressure head and the pressing table are connected by a flexible coupling.

[0012] The lower end of the shaft is connected to the ejector seat, the ejector seat is fixedly connected to the movable end of the cylinder, and the fixed end of the cylinder is fixed on the frame.

[0013] A vertically mounted drive motor is fixed to the upper end of the ejector seat. The output shaft of the drive motor is coaxially and fixedly connected to the drive gear. The drive gear meshes with the driven gear. The driven gear is coaxially and fixedly mounted on the outside of the shaft. The lower end of the shaft is rotatably connected to the ejector seat.

[0014] The present invention discloses a method for operating an integrated device for PTFE sheet pressing and sealing performance testing, the method comprising the following steps:

[0015] S1: Parameter setting: Start the controller to set the press-fit interference and sealing detection threshold;

[0016] S2: Workpiece assembly: Place the skeleton and PTFE sheet into the placement hole of the fixed base according to the assembly requirements;

[0017] S3: Press Start: Trigger switch controls the start of stepper motor, which drives ball screw assembly to move press table and press head downward;

[0018] S4: Coaxial positioning: The sleeve contacts the stepped hole on the fixed base, and the initial coaxial positioning is completed by axial sliding;

[0019] S5: Press-fit detection: After the press head contacts the PTFE sheet, the force sensor provides real-time feedback of pressure data, and the grating sensor and displacement sensor synchronously monitor the displacement of the press head. The controller controls the press-fit stroke in a closed loop according to the preset interference fit.

[0020] S6: Sealing test: The set pressure gas is input through the air supply channel of the sealing test seat, and the pressure sensor feeds back the pressure data in real time to detect the airtightness of the product after pressing. If the leakage exceeds the threshold, the product is unqualified.

[0021] S7: Ejection and unloading: The cylinder drives the sealing detection seat to eject the product. If the product is unqualified, the controller triggers an automatic air gun to blow the unqualified product to the scrap area; if the product is qualified, the product is removed to complete the pressing work.

[0022] S8: Multi-directional pressing: After a single pressing is completed, the drive motor drives the seal detection seat to rotate around the shaft by φ degrees, and the pressing steps are repeated until the cumulative rotation angle reaches 360° to eliminate the radial error of the tooling.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention solves the coaxiality deviation problem caused by tolerance accumulation in traditional processes by using a flexible coupling and a guide sleeve for coordinated positioning. Combined with closed-loop control of force sensors, displacement sensors, and stepper motors, it achieves precise control of the press-fit interference, ensuring batch stability. A multi-directional rotary press-fit process eliminates radial pressure unevenness and integrates a sealing detection function. Through real-time airtightness testing and an adaptive compensation structure (shape memory polymer coating + heating module), a press-fit-detection closed-loop system is formed. This improves coaxiality accuracy while achieving process integration and automatic sorting of defective products, systematically overcoming the technical bottlenecks of difficult coaxiality control, large interference fluctuations, and redundant detection in high-precision press-fitting. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 yes Figure 1 Enlarged view of point A;

[0027] Figure 3 This is a schematic diagram illustrating the sealing test performed after the product is press-fitted.

[0028] Figure 4 This is a schematic diagram of the product being ejected after being pressed. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] An integrated device for PTFE sheet pressing and sealing performance testing includes a platform 1, a support 8, a pressing head 12, a fixed base 15, a control mechanism, and a sealing test seat 16. The support 8 and the control mechanism are mounted on the platform 1. The pressing head 12 is mounted on the control mechanism. The pressing head 12 moves by slidingly connecting to the column of the support 8 through the control mechanism. The fixed base 15 is mounted in the middle of the base plate of the support 8. The fixed base 15 is correspondingly matched with the pressing head 12. The sealing test seat 16 is provided inside the fixed base 15.

[0031] The control mechanism includes a gearbox 2, a ball screw assembly 3, a stepper motor 4, a switch 5, a controller 6, and a pressing table 7. The output shaft of the stepper motor 4 is fixedly connected to the input end of the gearbox 2, the output end of the gearbox 2 is fixedly connected to the screw of the ball screw assembly 3, the nut of the ball screw assembly 3 is fixedly connected to the middle of the pressing table 7, the two sides of the pressing table 7 are slidably connected to the two columns of the bracket 8, and a pressing head 12 is installed in the middle of the lower surface of the pressing table 7. The stepper motor 4 is connected to the controller 6 for signal transmission, and the controller 6 controls the opening and closing through the switch 5.

[0032] The ball screw assembly 3 is equipped with a displacement sensor, and the lower surface of the pressing table 7 is equipped with a grating sensor 9. Both the displacement sensor and the grating sensor 9 are connected to the controller 6 for signal transmission and are used to measure the displacement of the pressing head 12.

[0033] The sealing detection seat 16 includes an integrally formed coaxial horizontal plate and a shaft. The shaft is fixed to the lower end of the horizontal plate. The horizontal plate is placed in the placement hole of the fixed base 15. The lower end of the shaft extends to the lower end of the base plate of the bracket 8. The middle part of the shaft passes through the upper surface of the horizontal plate and is provided with an air supply channel, which is connected to an external air source. A force sensor 10 is installed on the pressure head 12, and the force sensor 10 is connected to the controller 6 for signal transmission.

[0034] The placement hole of the fixed base 15 is a stepped hole that decreases radially from top to bottom. The lower hole of the stepped hole is used to place the skeleton 17, the PTFE sheet 18 and the sealing detection seat 16. The outer side of the pressure head 12 is fitted with a sleeve 14 with clearance. The outer wall of the sleeve 14 is in clearance sliding fit with the inner wall of the upper hole of the stepped hole. The guide sleeve 14 is used to ensure coaxiality.

[0035] The sleeve 14 has a vertical groove on its side wall, and a screw 13 is slidably installed in the vertical groove. The screw 13 is threadedly fixed to the pressure head 12. The sleeve 14 can move axially within a certain range to cooperate with the fixed base 15 in advance and further ensure coaxiality.

[0036] The inner wall of the sleeve 14 is coated with a shape memory polymer coating SMP with a glass transition temperature Tg = 60 ± 5℃. The shape memory polymer coating may also be doped with 10% carbon nanotubes (CNTs) to enhance thermal conductivity. The coating thickness is 0.3-1.0 mm and the surface roughness Ra ≤ 0.8 μm. The outer wall of the sleeve 14 is provided with an annular heating module, which is connected to the controller 6 for signal transmission.

[0037] When the coaxiality deviation of the press fitting is greater than 0.05mm, the controller 6 starts the heating module and heats up to Tg+20℃ within 10 seconds, causing the SMP to enter a high elastic state, softening the shape memory polymer coating and adaptively filling the gap; after cooling, a customized guide surface is formed, and the SMP cools down to below Tg within 40 seconds to compensate for tooling wear error.

[0038] It can also record the deviation, temperature curve, and deformation recovery rate of each compensation, establish a compensation parameter-effect mapping table, and train a BPNN neural network model based on historical data to predict the optimal heating parameters, temperature, and duration for different wear stages. After every 100 press fittings, the compensation strategy is automatically optimized, improving the average compensation efficiency by 15%-20%. This achieves adaptive and predictive maintenance of tooling error compensation, extends the life of key components by more than 3 times, and reduces the frequency of downtime calibration.

[0039] The pressure head 12 is connected to the pressing table 7 by a flexible coupling 11. The flexible coupling 11 can move radially within a certain range to ensure the coaxiality of the pressing.

[0040] The lower end of the shaft is connected to the ejector seat 23, the ejector seat 23 is fixedly connected to the movable end of the cylinder, and the fixed end of the cylinder is fixed on the frame 1. The cylinder is not shown in the attached drawings.

[0041] The ejector seat 23 is slidably connected to the frame 1. The cylinder drives the sealing detection seat 16 to move axially, which is used to eject the external skeleton type PTFE sheet after pressing, making it easy to pick up.

[0042] The upper end of the ejector seat 23 is fixed with a vertically arranged drive motor 22 via a mounting base. The output shaft of the drive motor 22 is coaxially and fixedly connected to the drive gear 21. The drive gear 21 is meshed with the driven gear 20. The driven gear 20 is coaxially and fixedly mounted on the outside of the shaft. The lower end of the shaft is rotatably connected to the ejector seat 23 via a bearing 24.

[0043] After each press-fit product is ejected, the drive motor 22 drives the sealing detection seat 16 to rotate radially by φ degrees to avoid tooling errors and ensure uniform pressure in the radial circumferential direction.

[0044] The value of angle φ is in the range of 5°≤φ≤30°, and 360 / φ is an integer.

[0045] An automatic air gun 19 is also installed on the bracket 8. The automatic air gun 19 is connected to an external air source and is connected to the controller 6 for signal transmission. The automatic air gun 19 can blow out high-pressure gas according to the control command to blow unqualified products to the waste area.

[0046] The present invention discloses a method for operating an integrated device for PTFE sheet pressing and sealing performance testing, the method comprising the following steps:

[0047] S1: Parameter setting: Start controller 6 to set the press-fit interference and sealing detection threshold;

[0048] S2: Workpiece assembly: Place the skeleton 17 and PTFE sheet 18 into the placement hole of the fixed base 15 according to the assembly requirements;

[0049] S3: Press Start: Trigger switch 5 controls the start of stepper motor 4, which drives ball screw assembly 3 to move press table 7 and press head 12 downward;

[0050] S4: Coaxial positioning: The sleeve 14 contacts the upper hole of the stepped hole of the fixed base 15, and the initial coaxial positioning is completed by axial sliding;

[0051] S5: Pressing detection: After the press head 12 contacts the PTFE sheet 18, the force sensor 10 provides real-time feedback of pressure data, the grating sensor 9 and the displacement sensor synchronously monitor the displacement of the press head 12, and the controller 6 controls the pressing stroke according to the preset interference fit closed loop.

[0052] S6: Sealing test: The set pressure gas is input through the air supply channel of the sealing test seat 16, and the pressure sensor 10 feeds back the pressure data in real time to detect the airtightness of the product after pressing. If the leakage exceeds the threshold, the product is unqualified.

[0053] S7: Ejection and unloading: The cylinder drives the sealing detection seat 16 to eject the product. If the product is unqualified, the controller 6 triggers the automatic air gun 19 to blow the unqualified product to the scrap area; if the product is qualified, the product is removed to complete the pressing work.

[0054] S8: Multi-directional pressing: After a single pressing is completed, the drive motor 22 drives the sealing detection seat 16 to rotate around the axis by φ degrees, and repeats the pressing steps until the cumulative rotation angle reaches 360° to eliminate the radial error of the tooling.

[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An integrated device for PTFE sheet pressing and sealing performance testing, characterized in that: The system includes a platform (1), a support (8), a pressure head (12), a fixed base (15), a control mechanism, and a sealing test seat (16). The support (8) and control mechanism are mounted on the platform (1). The pressure head (12) is mounted on the control mechanism and is slidably connected to the column of the support (8) via the control mechanism. The fixed base (15) is mounted in the middle of the base plate of the support (8). An automatic air gun (19) is also mounted on the support (8). The fixed base (15) and the pressure head (12) are correspondingly matched. 15) An internal sealing detection seat (16) is provided; the control mechanism includes a gearbox (2), a ball screw assembly (3), a stepper motor (4), a switch (5), a controller (6), and a pressing table (7); the output shaft of the stepper motor (4) is fixedly connected to the input end of the gearbox (2), the output end of the gearbox (2) is fixedly connected to the screw of the ball screw assembly (3), the nut of the ball screw assembly (3) is fixedly connected to the middle part of the pressing table (7), the ball screw assembly (3) is equipped with a displacement sensor, and the pressing table (7) The two sides of the platen (7) are slidably connected to the two columns of the support (8). A pressure head (12) and a grating sensor (9) are installed in the middle of the lower surface of the pressure table (7). The stepper motor (4) is connected to the controller (6) for signal transmission. The controller (6) controls the opening and closing through the switch (5). The sealing detection seat (16) includes a horizontal plate and a shaft. The shaft is fixed at the lower end of the horizontal plate. The horizontal plate is placed in the placement hole of the fixed base (15). The lower end of the shaft extends to the lower end of the bottom plate of the support (8). The middle part of the shaft penetrates the upper surface of the horizontal plate. There is an air supply channel, which is connected to an external air source; a force sensor (10) is installed on the pressure head (12), and the force sensor (10) is connected to the controller (6) for signal transmission; the placement hole of the fixed base (15) is a stepped hole that decreases radially from top to bottom, and the lower hole of the stepped hole is used to place the skeleton (17), PTFE sheet (18) and sealing detection seat (16); a sleeve (14) is slidably fitted on the outer side of the pressure head (12), and the outer wall of the sleeve (14) is slidably fitted with the inner wall of the upper hole of the stepped hole.

2. The integrated device for PTFE sheet pressing and sealing performance testing according to claim 1, characterized in that: The sleeve (14) has a vertical groove on its side wall, and a screw (13) is slidably disposed in the vertical groove. The screw (13) is threadedly fixed to the pressure head (12).

3. The integrated device for PTFE sheet pressing and sealing performance testing according to claim 2, characterized in that: The inner wall of the sleeve (14) is coated with a shape memory polymer coating, and the outer wall of the sleeve (14) is provided with an annular heating module, which is connected to the controller (6) for signal transmission.

4. The integrated device for PTFE sheet pressing and sealing performance testing according to claim 2 or 3, characterized in that: The pressure head (12) is connected to the pressing table (7) via a flexible coupling (11).

5. The integrated device for PTFE sheet pressing and sealing performance testing according to claim 3, characterized in that: The lower end of the shaft is connected to the ejector seat (23), the ejector seat (23) is fixedly connected to the movable end of the cylinder, and the fixed end of the cylinder is fixed on the frame (1).

6. The integrated device for PTFE sheet pressing and sealing performance testing according to claim 5, characterized in that: The upper end of the ejector seat (23) is fixed with a vertically arranged drive motor (22). The output shaft of the drive motor (22) is coaxially fixedly connected to the drive gear (21). The drive gear (21) is meshed with the driven gear (20). The driven gear (20) is coaxially fixedly mounted on the outside of the shaft. The lower end of the shaft is rotatably connected to the ejector seat (23).

7. A method for operating the integrated PTFE sheet pressing and sealing performance testing device according to any one of claims 1-6, characterized in that: The method includes the following steps: S1: Parameter setting: Start the controller (6) to set the press-fit interference and sealing detection threshold; S2: Workpiece assembly: Place the skeleton (17) and PTFE sheet (18) into the placement hole of the fixed base (15) according to the assembly requirements; S3: Press Start: Trigger switch (5) controls the start of stepper motor (4), which drives ball screw assembly (3) to move press table (7) and press head (12) downward; S4: Coaxial positioning: The sleeve (14) contacts the stepped hole on the fixed base (15) and completes the initial coaxial positioning by axial sliding; S5: Pressing detection: After the press head (12) contacts the PTFE sheet (18), the force sensor (10) provides real-time feedback of pressure data, the grating sensor (9) and the displacement sensor synchronously monitor the displacement of the press head (12), and the controller (6) controls the pressing stroke according to the preset interference closed loop. S6: Sealing test: The set pressure gas is input through the air supply channel of the sealing test seat (16), and the pressure sensor (10) feeds back the pressure data in real time to detect the airtightness of the product after pressing. If the leakage exceeds the threshold, the product is unqualified. S7: Ejection and unloading: The cylinder drives the sealing detection seat (16) to eject the product. If the product is unqualified, the controller (6) triggers the automatic air gun (19) to blow the unqualified product to the scrap area. If the product is qualified, the product is removed to complete the pressing work. S8: Multi-directional pressing: After a single pressing is completed, the drive motor (22) drives the sealing detection seat (16) to rotate around the axis by φ degrees, and repeats the pressing steps until the cumulative rotation angle reaches 360° to eliminate the radial error of the tooling.

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