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

Abstract

The invention discloses a PTFE sheet press-fitting and sealing performance detection integrated device and a method thereof, and belongs to the technical field of sealing element production. A support and a control mechanism are installed on the rack, a pressing head is installed on the control mechanism and is in sliding connection with a stand column of the support through the control mechanism to complete movement, a fixed base is installed in the middle of a bottom plate of the support, the fixed base and the pressing head are correspondingly arranged in a matched mode, and a sealing detection base is arranged in the fixed base. The method comprises the following steps: setting parameters; assembling the workpiece; press fitting is started; coaxial positioning is carried out; performing press fitting detection; testing the sealing performance; ejecting and unloading; and pressing in multiple directions. The problem of coaxiality deviation caused by tolerance accumulation in a traditional process is solved, accurate regulation and control of press fitting interference magnitude are achieved, batch stability is ensured, process integration and automatic sorting of unqualified products are achieved while the coaxial precision is improved, and the production efficiency is improved. And the technical bottlenecks of difficult coaxiality control, large interference magnitude fluctuation and detection redundancy in high-precision press fitting are systematically overcome.

Description

Technical Field

[0001] The invention relates to a PTFE sheet press-fitting and sealing detection integrated device and method thereof, belonging to the technical field of sealing component production. Background Art

[0002] The traditional press-fitting device for the exposed skeleton PTFE sheet mainly uses the stroke control of the press-fitting machine to achieve the press-fitting effect. However, due to the cumulative effect of tolerances among the press-fitting machine, the exposed skeleton and the fixed base, it is difficult to ensure the coaxiality control and interference stability of the exposed skeleton PTFE sheet during the press-fitting process. Specifically, the press-fitting amount distributed along the circumference in the radial direction shows significant unevenness, and with the wear of the tooling or batch replacement, the fluctuation amplitude is further aggravated, which seriously restricts the realization of high-precision press-fitting requirements.

[0003] At the same time, under the existing technical system, there is a lack of real-time detection function for the sealing performance of the product after pressing, which leads to the need for secondary verification of the product after pressing through offline detection equipment, increasing the complexity of the process. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the present invention provides a PTFE sheet pressing and sealing detection integrated device and method.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a PTFE sheet pressing and sealing detection integrated device, including a stand, a bracket, a pressure head, a fixed base, a control mechanism and a sealing detection seat; the stand is installed with a bracket and a control mechanism, the control mechanism is installed with a pressure head, the pressure head is connected with the column of the bracket through the control mechanism to complete the movement, the middle part of the bottom plate of the bracket is installed with a fixed base, the fixed base and the pressure head are arranged correspondingly, and a sealing detection seat is provided in the fixed base.

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

[0007] The sealing detection seat includes a horizontal plate and an axis rod, the axis rod is fixed at 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 axis rod extends to the lower end of the bracket bottom plate, the middle part of the axis rod 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, and the force sensor is connected to the controller 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, the PTFE sheet and the sealing detection seat. The outer clearance sliding sleeve of the pressure head is equipped with a sleeve, and the outer wall of the sleeve is slidingly matched with the inner wall clearance of the upper hole of the stepped hole.

[0009] A vertical groove is arranged on the side wall of the sleeve, a screw is slidably arranged in the vertical groove, and the screw is fixedly connected with the pressing head thread.

[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, and the heating module is connected to the controller for signal transmission.

[0011] The pressing head is connected to the pressing platform via a flexible coupling.

[0012] The lower end of the shaft rod 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 stand.

[0013] A vertically arranged driving motor is fixed to the upper end of the ejection seat, the output shaft of the driving motor is coaxially fixedly connected with the driving gear, the driving gear is meshedly connected with the driven gear, the driven gear is coaxially fixedly sleeved on the outside of the shaft, and the lower end of the shaft is rotatably connected with the ejection seat.

[0014] A working method of a PTFE sheet press-fitting and sealing detection integrated device of the present invention comprises 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 frame and PTFE sheet into the placement hole of the fixed base according to the assembly requirements;

[0017] S3: Press-fit start: The trigger switch controls the start of the stepper motor, driving the ball screw assembly to move the press-fit table and the press head downward;

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

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

[0020] S6: Sealing test: The set air pressure is input through the air supply channel of the sealing detection seat, and the force sensor feeds back the pressure data in real time to detect the air tightness of the product after press-fitting. 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 the automatic air gun to blow the unqualified product to the waste area; if the product is qualified, the product is removed to complete the pressing work;

[0022] S8: Multi-directional pressing: After completing a single press, the driving motor drives the seal detection seat to rotate φ degrees around the axis, and repeats the press steps until the cumulative rotation angle reaches 360° to eliminate the radial error of the tooling.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention solves the problem of coaxiality deviation caused by tolerance accumulation in traditional processes through the coordinated positioning of the flexible coupling and the guide sleeve; combines the closed-loop control of the force sensor, displacement sensor and stepper motor to achieve precise regulation of the press-fitting interference amount and ensure batch stability; adopts a multi-directional rotary press-fitting process to eliminate radial press unevenness, and integrates a sealing detection function, and forms a press-fitting-detection closed-loop system through real-time airtightness testing and an adaptive compensation structure (shape memory polymer coating + heating module). While improving the coaxial accuracy, it realizes process integration and automatic sorting of defective products, and systematically overcomes the technical bottlenecks of difficult coaxiality control, large interference fluctuations and redundant detection in high-precision press-fitting. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] Figure 2 yes Figure 1 A magnified image of point A;

[0027] Figure 3 This is a schematic diagram of the sealing test after the product is pressed;

[0028] Figure 4 It is a working diagram of the product being ejected after being pressed. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] A PTFE sheet pressing and sealing detection integrated device comprises a stand 1, a bracket 8, a pressure head 12, a fixed base 15, a control mechanism and a sealing detection seat 16; the stand 1 is installed with the bracket 8 and the control mechanism, the pressure head 12 is installed on the control mechanism, the pressure head 12 is slidably connected with the column of the bracket 8 through the control mechanism to complete the movement, the fixed base 15 is installed in the middle of the bottom plate of the bracket 8, the fixed base 15 is arranged to correspond to the pressure head 12, and the sealing detection seat 16 is arranged in the fixed base 15.

[0031] The control mechanism includes a transmission 2, a ball screw assembly 3, a stepper motor 4, a switch 5, a controller 6 and a press-fitting table 7; the output shaft of the stepper motor 4 is fixedly connected to the input end of the transmission 2, the output end of the transmission 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 press-fitting table 7, the two sides of the press-fitting table 7 are correspondingly 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 press-fitting table 7; the stepper motor 4 is connected to the controller 6 for signal transmission, and the controller 6 controls opening and closing through the switch 5.

[0032] The ball screw assembly 3 is internally provided with a displacement sensor, and the lower surface of the press-fitting table 7 is installed 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 press head 12 .

[0033] The sealing detection seat 16 includes an integrally formed coaxially arranged horizontal plate and an axis rod, the axis rod 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 axis rod extends to the lower end of the bottom plate of the bracket 8, the middle part of the axis rod passes through the upper surface of the horizontal plate and is provided with an air supply channel, and the air supply channel 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 clearance sliding sleeve of the pressure head 12 is equipped with a sleeve 14. The outer wall of the sleeve 14 is slidably matched with the inner wall clearance of the upper hole of the stepped hole. The guide sleeve 14 is used to ensure coaxiality.

[0035] The side wall of the sleeve 14 is provided with a vertical groove, in which a screw 13 is slidably provided. The screw 13 is threadedly fixedly connected to the pressure head 12. The sleeve 14 can move axially within a certain range to cooperate with the fixed base 15 in advance to further ensure coaxiality.

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

[0037] When the press-fit coaxiality deviation is greater than 0.05 mm, the controller 6 starts the heating module and raises the temperature to Tg+20°C within 10 seconds, so that the SMP enters a highly elastic state, the shape memory polymer coating softens and adaptively fills the gap; after cooling, a customized guide surface is formed, and the SMP cools to below Tg within 40 seconds to compensate for the tooling wear error.

[0038] At the same time, it can also record the deviation, temperature curve, and deformation recovery rate of each compensation, establish a compensation parameter-effect mapping table, train the neural network model BPNN based on historical data, and predict the optimal heating parameter temperature and duration at different wear stages. After completing every 100 press-fits, the compensation strategy is automatically optimized to increase the average compensation efficiency by 15%-20%, realizing adaptive and predictive maintenance of tooling error compensation, extending the life of key components by more than 3 times, and reducing the frequency of downtime calibration.

[0039] The pressing head 12 is connected to the pressing platform 7 via 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, and the ejector seat 23 is fixedly connected to the movable end of the cylinder. The fixed end of the cylinder is fixed on the stand 1, and the cylinder is not drawn in the accompanying drawings.

[0041] The ejection seat 23 is slidably connected to the stand 1, and the cylinder drives the sealing detection seat 16 to move axially, so as to eject the leaking skeleton PTFE sheet after the press-fitting is completed, so as to facilitate taking.

[0042] A vertically arranged driving motor 22 is fixed to the upper end of the ejection seat 23 through a mounting seat, and the output shaft of the driving motor 22 is coaxially fixedly connected with the driving gear 21, and the driving gear 21 is meshedly connected with the driven gear 20, and the driven gear 20 is coaxially fixedly sleeved on the outer side of the shaft, and the lower end of the shaft is rotatably connected with the ejection seat 23 through a bearing 24.

[0043] Each time after the sealing detection seat 16 ejects the pressed product, the driving motor 22 drives the sealing detection seat 16 to rotate radially by φ degrees, so as to avoid tooling errors and ensure uniform pressure in the radial and circumferential directions.

[0044] The value range of the φ angle is 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. The automatic air gun 19 is connected to the controller 6 for signal transmission. The automatic air gun 19 can blow out high-pressure gas according to control instructions to blow unqualified products into the waste area.

[0046] A working method of a PTFE sheet press-fitting and sealing detection integrated device of the present invention comprises the following steps:

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

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

[0049] S3: Press-fit start: trigger switch 5 to start stepper motor 4, drive ball screw assembly 3 to drive press-fit table 7 and press head 12 to move downward;

[0050] S4: Coaxial positioning: The sleeve 14 contacts the upper hole of the stepped hole of the fixed base 15, and completes the preliminary coaxial positioning through axial sliding;

[0051] S5: Press-fit detection: After the press head 12 contacts the PTFE sheet 18, the force sensor 10 feeds back pressure data in real time, the grating sensor 9 and the displacement sensor synchronously monitor the displacement of the press head 12, and the controller 6 controls the press-fit stroke in a closed loop according to the preset interference amount;

[0052] S6: Sealing test: input the set air pressure gas through the air supply channel of the sealing detection seat 16, and the force sensor 10 feeds back the pressure data in real time to detect the air tightness of the product after press-fitting. 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 waste area; if the product is qualified, the product is removed to complete the pressing work;

[0054] S8: Multi-directional pressing: After completing a single press-fitting, the driving motor 22 drives the sealing detection seat 16 to rotate around the axis by φ degrees, and the press-fitting steps are repeated 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 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 the spirit or essential features of the invention. 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, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0056] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A PTFE sheet press-fitting and sealing detection integrated device, characterized in that: The invention comprises a stand (1), a bracket (8), a pressure head (12), a fixed base (15), a control mechanism and a sealing detection seat (16); the bracket (8) and the control mechanism are installed on the stand (1); the pressure head (12) is installed on the control mechanism; the pressure head (12) is slidably connected with a column of the bracket (8) through the control mechanism to complete movement; a fixed base (15) is installed in the middle of the bottom plate of the bracket (8); the fixed base (15) and the pressure head (12) are arranged in a corresponding manner; and a sealing detection seat (16) is arranged in the fixed base (15).

2. The PTFE sheet press-fitting and sealing detection integrated device according to claim 1, characterized in that: The control mechanism comprises a transmission (2), a ball screw assembly (3), a stepper motor (4), a switch (5), a controller (6) and a press-fitting platform (7); the output shaft of the stepper motor (4) is fixedly connected to the input end of the transmission (2), the output end of the transmission (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 press-fitting platform (7), the two sides of the press-fitting platform (7) are correspondingly 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 press-fitting platform (7); the stepper motor (4) is connected to the controller (6) for signal transmission, and the controller (6) is controlled to open and close through the switch (5).

3. The PTFE sheet press-fitting and sealing detection integrated device according to claim 1, characterized in that: The sealing detection seat (16) includes a horizontal plate and an axle, wherein the axle is fixed at the lower end of the horizontal plate, and the horizontal plate is placed in a placement hole of a fixed base (15). The lower end of the axle extends to the lower end of the bottom plate of the bracket (8). The middle part of the axle passes through the upper surface of the horizontal plate and is provided with an air supply channel, and the air supply channel 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.

4. The PTFE sheet press-fitting and sealing detection integrated device according to claim 3, characterized in that: 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 clearance sliding sleeve of the pressure head (12) is provided with a sleeve (14), and the outer wall of the sleeve (14) is in clearance sliding fit with the inner wall of the upper hole of the stepped hole.

5. The PTFE sheet press-fitting and sealing detection integrated device according to claim 4, characterized in that: A vertical groove is provided on the side wall of the sleeve (14), a screw (13) is slidably provided in the vertical groove, and the screw (13) is threadedly fixedly connected to the pressure head (12).

6. The PTFE sheet press-fitting and sealing detection integrated device according to claim 5, 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, and the heating module is connected to the controller (6) for signal transmission.

7. A PTFE sheet press-fitting and sealing detection integrated device according to claim 2 or 6, characterized in that: The pressing head (12) and the pressing platform (7) are connected via a flexible coupling (11).

8. The PTFE sheet press-fitting and sealing detection integrated device according to claim 3, characterized in that: The lower end of the shaft rod is connected to an ejection seat (23), the ejection seat (23) is fixedly connected to the movable end of the cylinder, and the fixed end of the cylinder is fixed on the stand (1).

9. The PTFE sheet press-fitting and sealing detection integrated device according to claim 8, characterized in that: A vertically arranged driving motor (22) is fixed to the upper end of the ejection seat (23); the output shaft of the driving motor (22) is coaxially fixedly connected to the driving gear (21); the driving gear (21) is meshingly connected to the driven gear (20); the driven gear (20) is coaxially fixedly sleeved on the outer side of the shaft; and the lower end of the shaft is rotatably connected to the ejection seat (23).

10. A working method of the integrated device for pressing and sealing of PTFE sheets according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: S1: parameter setting: start the controller (6) to set the press-fit interference and sealing detection thresholds; S2: Workpiece assembly: placing the frame (17) and the PTFE sheet (18) into the placement hole of the fixed base (15) according to assembly requirements; S3: Press-fit start: The trigger switch (5) controls the start of the stepper motor (4), driving the ball screw assembly (3) to drive the press-fit platform (7) and the press head (12) to move downward; S4: Coaxial positioning: The sleeve (14) contacts the upper hole of the stepped hole of the fixed base (15), and the preliminary coaxial positioning is completed by axial sliding; S5: Press-fit detection: After the pressing head (12) contacts the PTFE sheet (18), the force sensor (10) feeds back pressure data in real time, the grating sensor (9) and the displacement sensor synchronously monitor the displacement of the pressing head (12), and the controller (6) controls the pressing stroke in a closed loop according to the preset interference amount; S6: Sealing test: inputting set air pressure gas through the air supply channel of the sealing detection seat (16), while the force sensor (10) feeds back pressure data in real time to detect the air tightness of the product after press-fitting. 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 waste area; if the product is qualified, the product is removed to complete the pressing work; S8: Multi-directional pressing: After completing a single press-fitting, the driving motor (22) drives the sealing detection seat (16) to rotate φ degrees around the axis, and the press-fitting steps are repeated until the cumulative rotation angle reaches 360 degrees, thereby eliminating the radial error of the tooling.

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