A polytetrafluoroethylene pipe joint hole drilling processing device assembled to a machine tool

Abstract

The present application relates to polytetrafluoroethylene pipe fitting processing technical field, especially polytetrafluoroethylene pipe fitting connecting hole drilling processing device for assembling machine tool, through the device, the conical block axial movement pushes the spherical ball to stretch out along the radial outward, and the uniform expansion of multiple points is carried out from the inner wall of the pipe fitting, and the outer cylinder thread drives the inner cylinder taper to contract radially to form annular clamping from the outer wall, realizing the double fixing of inside and outside cooperation.Polytetrafluoroethylene material has lower surface hardness and elastic modulus, and traditional unilateral clamping is easy to cause pipe deformation or slip due to uneven stress, and the scheme realizes the double fixing of inside and outside cooperation.Polytetrafluoroethylene material has lower surface hardness and elastic modulus, and traditional unilateral clamping is easy to cause pipe deformation or slip due to uneven stress, and the scheme realizes the double fixing of inside and outside cooperation.

Description

Technical Field

[0001] This invention relates to the field of polytetrafluoroethylene (PTFE) pipe processing technology, and in particular to a drilling device for PTFE pipe connection holes mounted on a machine tool. Background Technology

[0002] In fluid transport systems across chemical, semiconductor, biopharmaceutical, and aerospace industries, polytetrafluoroethylene (PTFE) pipe fittings are widely used as the core material for corrosion-resistant pipelines, ultrapure pipelines, and sealing connections due to their excellent corrosion resistance, high and low temperature resistance, and low coefficient of friction. However, because PTFE has relatively low surface hardness and a high elastic modulus, it is prone to plastic deformation during machining due to excessive clamping force, leading to out-of-roundness of the inner hole, indentations on the outer wall, or dimensional deviations. Furthermore, PTFE has a high coefficient of thermal expansion, and unstable clamping during drilling can easily cause quality problems such as hole misalignment, hole diameter deviation, or surface scratches. Therefore, achieving reliable fixation and precise positioning of PTFE pipe fittings during drilling has always been a key factor restricting processing efficiency and product quality.

[0003] Existing devices mostly use external clamping to fix pipe fittings. This single-sided or double-sided external clamping method is prone to producing local indentations on the pipe surface, and uneven clamping force distribution may also cause the pipe cross-section to become out of round. Although some solutions attempt to improve the stress condition by increasing the number of clamping points, due to the low hardness of polytetrafluoroethylene, the contact area and pressure distribution of external clamping can never simultaneously meet the dual requirements of reliable fixation and no damage to the pipe fitting.

[0004] In existing equipment, drill bit height adjustment mostly relies on threaded lifting mechanisms. Although these mechanisms can achieve positional adjustment within a certain range, they lack precise control over the axial position of the drill bit, i.e., the distance from the hole to the end face of the pipe fitting. When processing pipe fittings with different hole diameters or positions, it is often necessary to readjust the fixture position or change the tooling. This changeover operation is cumbersome and time-consuming, making it difficult to meet the actual needs of rapid changeover in multi-variety, small-batch production.

[0005] During drilling of polytetrafluoroethylene (PTFE) materials, burrs or flash are easily generated at the hole edges, requiring subsequent chamfering or deburring. Existing equipment only has drilling capabilities; hole finishing requires transferring the pipe to other equipment or changing tools for secondary processing. This not only increases the time spent on process changeovers and re-clamping but also affects the consistency of hole quality due to repeated positioning errors. Furthermore, existing equipment lacks effective protection measures for the chips generated during drilling. Splashing chips into moving parts such as guide rails can easily cause wear or jamming, affecting the long-term accuracy of the equipment. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a drilling device for connecting holes of polytetrafluoroethylene pipes, which is mounted on a machine tool, thereby solving the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A drilling device for connecting holes of polytetrafluoroethylene (PTFE) pipe fittings, mounted on a machine tool, includes a base, a guide rail on the base, a mounting bracket slidably mounted on the guide rail, a first air pump inside the mounting bracket, a connecting rod at the output end of the first air pump, a conical block at the end of the connecting rod away from the first air pump, a mounting cylinder slidably mounted on the side wall of the conical block, a sphere inside the mounting bracket, a retaining sleeve on the side wall of the mounting bracket, an outer cylinder rotatably mounted on the side wall of the mounting bracket, an inner cylinder threaded inside the outer cylinder, a limit strip inside the mounting bracket, and a... It has a circular ring, a mounting plate on the side wall of the base, a motor rotatably mounted on the side wall of the mounting plate, a synchronous belt drive assembly on the side wall of the motor output end, a rotating shaft inside the synchronous belt drive assembly, a slider rotatably mounted on the side wall of the rotating shaft, a grinding roller on the end of the rotating shaft away from the synchronous belt drive assembly, a drill bit on the end of the grinding roller away from the rotating shaft, a threaded rod on the side wall of the slider, an auxiliary shaft inside the synchronous belt drive assembly, a spring rod on the side wall of the auxiliary shaft, a second air pump on the side wall of the base, and a roller shutter-type protective cover on the side wall of the mounting bracket.

[0009] In one possible implementation, the mounting cylinder is disposed on the side wall of the mounting frame.

[0010] In one possible implementation, the spheres and the annular array of ferrules are arranged on the sidewall of the cylinder.

[0011] In one possible implementation, the limiting strip is slidably disposed inside the inner cylinder.

[0012] In one possible implementation, the ends of both the outer and inner cylinders that are furthest from the mounting bracket are gradually tapering.

[0013] In one possible implementation, the inner cylinder's contraction end has multiple axial gaps evenly distributed along the circumference.

[0014] In one possible implementation, the motor is fixedly mounted on the side of the base.

[0015] In one possible implementation, the slider is mounted on the mounting disk.

[0016] In one possible implementation, the spring rod is mounted on the mounting plate.

[0017] In one possible implementation, the output end of the second air pump is mounted on the mounting bracket, and the end of the roll-up protective cover furthest from the mounting bracket is mounted on the base.

[0018] Beneficial effects compared to existing technologies:

[0019] 1. In this solution, the device uses the axial movement of the conical block to push the ball outward radially, achieving multi-point uniform expansion and tightening from the inner wall of the pipe. This, combined with the outer cylinder thread driving the radial contraction of the inner cylinder's conical opening to form a ring clamp from the outer wall, achieves dual fixation through internal and external coordination. Polytetrafluoroethylene (PTFE) material has low surface hardness and elastic modulus. Traditional single-sided clamping is prone to pipe deformation or slippage due to uneven force. This solution, through multi-point contact of the inner wall expansion and uniform pressure of the outer wall clamping, effectively prevents the pipe from rotating or shifting axially during drilling, ensuring the accuracy of the processing position and avoiding pipe indentation or deformation caused by excessive local clamping force.

[0020] 2. In this design, the operator rotates a vertically mounted threaded rod, causing the slider to move up and down in the guide groove. The rotating shaft moves accordingly, while the auxiliary shaft, elastically supported by a spring rod, adaptively adjusts its angle and position to achieve precise alignment of the drill bit axis with the predetermined machining position. The drill bit is mounted at the end of the rotating shaft via a standard chuck or quick-change interface, allowing for rapid replacement according to different drilling requirements. This design solves the problem of frequent switching between different hole diameters and positions during PTFE pipe drilling, eliminating the need to redesign or replace the entire fixture set, significantly improving the versatility and changeover efficiency of the device.

[0021] 3. In this design, a grinding roller is coaxially mounted at the tail of the drill bit. Its outer diameter is slightly larger than the drill bit's diameter. When the drill bit completes drilling and retracts, the grinding roller immediately chamfers or deburrs the edge of the hole. This eliminates the need to change tools or transfer the drill bit to other equipment for finishing after drilling, reducing the time spent on secondary clamping and positioning errors, and improving hole quality and processing efficiency. Simultaneously, the roller-type protective covers at both ends of the mounting frame automatically extend and retract with the frame's movement, effectively preventing chips from splashing into the guide rail and causing wear or jamming, thus ensuring the long-term motion accuracy of the linear guide rail and the service life of the device. Attached Figure Description

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the guide rail structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the mounting bracket structure of the present invention;

[0026] Figure 4 This is a schematic diagram of the outer cylinder structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the annular structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the inner cylinder structure of the present invention;

[0029] Figure 7 This is a schematic diagram of the spherical structure of the present invention;

[0030] Figure 8 This is a schematic diagram of the installation disk structure of the present invention.

[0031] Legend: 11. Base; 12. Guide rail; 13. Mounting bracket; 14. First air pump; 15. Connecting rod; 16. Conical block; 17. Mounting cylinder; 18. Ball; 19. Sleeve; 21. Outer cylinder; 22. Inner cylinder; 23. Limiting strip; 24. Ring; 25. Mounting plate; 26. Motor; 27. Synchronous belt drive assembly; 28. Rotating shaft; 29. ​​Slider; 31. Grinding roller; 32. Drill bit; 33. Threaded rod; 34. Auxiliary shaft; 35. Spring rod; 36. Second air pump; 37. Roller-type protective cover. Detailed Implementation

[0032] Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can also be implemented in various different forms, and therefore the present invention is not limited to the embodiments described below.

[0033] The technical solution in this application embodiment is to solve the problems mentioned in the background art, and the overall idea is as follows:

[0034] Example:

[0035] Please refer to Figures 1 to 8 As shown in the figure, this embodiment introduces a drilling device for connecting holes of polytetrafluoroethylene (PTFE) pipe fittings assembled on a machine tool, which includes a base 11. The base 11 serves as the supporting foundation for the entire device, and two high-precision linear guide rails 12 are arranged parallel to each other on its upper surface. The guide rails 12 facilitate the smooth movement of the subsequent mounting frame 13, ensuring straightness and repeatability during the movement. The mounting frame 13 is slidably mounted on the guide rails 12 to support the clamping mechanism, drilling mechanism, and feed mechanism to be installed subsequently, and to provide stable support and guidance.

[0036] When the device is put into use, the operator first inserts the PTFE pipe fitting to be processed onto the outer wall of the mounting cylinder 17, so that the inner hole of the pipe fitting is initially fitted with the outer circle of the mounting cylinder 17. At this time, the first air pump 14 is started, and the piston rod of the first air pump 14 extends forward, pushing the connecting rod 15 connected to it to move horizontally in the axial direction. A conical block 16 is fixedly connected to the front end of the connecting rod 15. The conical block 16 is fitted into the inside of the mounting cylinder 17, and a wedge-shaped gap is formed between its outer conical surface and the inner wall of the mounting cylinder 17. When the conical block 16 moves forward under the push of the connecting rod 15, its outer conical surface gradually squeezes the ball 18 located in the radial through hole in the side wall of the mounting cylinder 17, forcing the ball 18 to move radially from the middle to both sides (i.e., from the center of the mounting cylinder 17 to the outer wall) until a part of the ball 18 protrudes from the side wall of the mounting cylinder 17 and tightly clamps the inner wall of the PTFE pipe fitting. The pipe fitting is initially tightened and fixed on the mounting cylinder 17 by using multi-point contact.

[0037] A ring of retaining sleeves 19 is arranged circumferentially on the outer wall of the mounting cylinder 17. The retaining sleeves 19 are made of elastic material, and their inner diameter is slightly smaller than that of the sphere 18. When the sphere 18 is pushed out by the conical block 16, the retaining sleeve 19 undergoes elastic deformation, encasing the sphere 18 and preventing it from accidentally detaching from the mounting sleeve during device vibration or pipe disassembly. This serves a dual purpose of preventing detachment and limiting positioning. The retaining sleeves 19, sphere 18, conical block 16, mounting cylinder 17, and connecting rod 15 together constitute a clamping unit. Subsequent connecting rods 15 are connected to the preceding conical blocks 16 via threads or pins, connecting multiple clamping units in series. All these units operate on the same principle and in the same manner. Notably, the end of the last section of the mounting cylinder 17 is a sealed structure, used to seal the internal channel of the mounting cylinder 17 and prevent the conical block 16 from detaching from the end during movement.

[0038] After the PTFE tubing is initially secured, the operator rotates the outer cylinder 21 counterclockwise. The outer cylinder 21 is rotatably mounted on the side wall of the mounting bracket 13 via bearings, and its inner wall is machined with internal threads. An inner cylinder 22 is coaxially mounted inside the outer cylinder 21, and the outer wall of the inner cylinder 22 is machined with external threads that mesh with the internal threads of the outer cylinder 21. When the outer cylinder 21 rotates, the inner cylinder 22 is restricted by a limiting strip 23 fixed to the side wall of the mounting bracket 13. The limiting strip 23 engages in the axial guide groove on the outer wall of the inner cylinder 22, preventing the inner cylinder 22 from rotating with the outer cylinder 21. Therefore, the inner cylinder 22 can only move in a horizontal linear motion along the axial direction. The end of the outer cylinder 21 away from the mounting bracket 13 is designed as a gradually tapering conical structure, and the end of the inner cylinder 22 away from the mounting bracket 13 is also a gradually tapering conical structure. Multiple axial gaps are evenly distributed along the circumference at the tapered end of the inner cylinder 22. As the inner cylinder 22 gradually moves towards the contraction end of the outer cylinder 21 under the threaded drive of the outer cylinder 21, the tapered portion of the inner cylinder 22 possesses radial contraction capability due to the presence of axial clearance. During the movement, it slowly clamps and locks against the side wall of the PTFE fitting, forming a uniform clamping force along the outer circumference of the fitting, thus securing the PTFE fitting again. This double-fixing method effectively prevents the PTFE fitting from rotating or shifting axially due to force during subsequent drilling, ensuring the accuracy of the machining position. A circular retaining ring 24 is also provided inside the outer cylinder 21. Its function is to prevent the inner cylinder 22 from excessively retracting and detaching from the interior of the outer cylinder 21 when the inner cylinder 22 rotates clockwise to reset, ensuring the reliability and safety of the mechanism's movement.

[0039] After all the work of fixing the PTFE pipe fittings is completed, the operator quickly replaces the drill bit 32 according to the size and shape of the hole required for the PTFE pipe fitting. The drill bit 32 is installed at the end of the rotating shaft 28 through a quick-change interface. After replacement, the operator rotates the vertically set threaded rod 33 according to the distance from the required hole position to the end face of the pipe fitting. The rotation of the threaded rod 33 will drive the slider 29 connected to it to move precisely up and down in the guide groove inside the mounting plate 25 until the slider 29 is adjusted to the appropriate distance position. At the same time as the slider 29 moves, the rotating shaft 28 inside the slider 29 will also move up and down accordingly. The synchronous belt drive assembly 27 set on the side wall of the rotating shaft 28 is used to transmit power from the motor 26 to the auxiliary shaft 34. Under the elastic support of the spring rod 35, the auxiliary shaft 34 can adaptively adjust its angle or position according to the change of the position of the rotating shaft 28, thereby achieving the effect of dynamically adjusting the spatial position of the rotating shaft 28 and ensuring that the axis of the drill bit 32 is always aligned with the predetermined processing position.

[0040] After all adjustments are completed, the drive motor 26, which is fixedly installed inside the mounting plate 25, is started. The output shaft of the motor 26 rotates, transmitting power to the synchronous belt drive assembly 27 via the drive pulley. The synchronous belt drive assembly 27 then smoothly transmits the power to the rotating shaft 28, which drives the drill bit 32 at the end to rotate at high speed, providing cutting power for drilling. After all preparations are complete, the operator starts the second air pump 36. The piston rod of the second air pump 36 extends, pushing the mounting frame 13 to move at a constant speed along the linear guide rail 12 on the base 11 towards the drill bit 32, so that the clamped PTFE tube gradually approaches the rotating drill bit 32, and drilling begins. At the same time, roller shutter-type protective covers 37 are provided at both the front and rear ends of the mounting frame 13. Their working principle is the same as that of a measuring tape. They can automatically extend or retract as the mounting frame 13 moves, which does not hinder the movement of the mounting frame 13 and effectively prevents the chips generated during drilling from splashing into the guide rail 12 of the base 11, causing wear or jamming. Specifically, a grinding roller 31 is coaxially arranged at the tail of the drill bit 32. Its outer diameter is slightly larger than that of the drill bit 32. When the drill bit 32 finishes drilling and withdraws, the grinding roller 31 immediately chamfers or deburrs the edge of the hole, realizing an integrated processing effect of finishing the hole after drilling. This reduces the time for process switching and secondary clamping, and improves processing efficiency and hole quality.

[0041] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool, comprising a base (11), characterized in that, The base (11) is provided with a guide rail (12), and a mounting bracket (13) is slidably mounted on the guide rail (12). A first air pump (14) is provided inside the mounting bracket (13). A connecting rod (15) is provided at the output end of the first air pump (14). A conical block (16) is provided at the end of the connecting rod (15) away from the first air pump (14). A mounting cylinder (17) is slidably mounted on the side wall of the conical block (16). A sphere (18) is provided inside the mounting bracket (13). A retainer (19) is provided on the side wall of the mounting bracket (13). An outer cylinder (21) is rotatably mounted on the side wall of the mounting bracket (13). An inner cylinder (22) is threadedly mounted inside the outer cylinder (21). A limit strip (23) is provided inside the mounting bracket (13). A ring (24) is provided inside the outer cylinder (21). A mounting bracket (27) is provided on the side wall of the base (11). The mounting plate (25) has a motor (26) rotatably mounted on its side wall. The output end of the motor (26) has a synchronous belt drive assembly (27) mounted on its side wall. The synchronous belt drive assembly (27) has a rotating shaft (28) inside. The rotating shaft (28) has a slider (29) rotatably mounted on its side wall. The end of the rotating shaft (28) away from the synchronous belt drive assembly (27) has a grinding roller (31) mounted on its side. The end of the grinding roller (31) away from the rotating shaft (28) has a drill bit (32) mounted on its side. The slider (29) has a threaded rod (33) mounted on its side wall. The synchronous belt drive assembly (27) also has an auxiliary shaft (34) inside. The auxiliary shaft (34) has a spring rod (35) mounted on its side wall. The base (11) has a second air pump (36) mounted on its side wall. The mounting bracket (13) has a roller shutter-type protective cover (37) mounted on its side wall.

2. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The mounting cylinder (17) is located on the side wall of the mounting frame (13).

3. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The spheres (18) and ferrules (19) are arranged in a ring array on the side wall of the cylinder.

4. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The limiting strip (23) is slidably disposed inside the inner cylinder (22).

5. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The outer cylinder (21) and the inner cylinder (22) are both in a gradually tapering state at the ends away from the mounting bracket (13).

6. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The inner cylinder (22) has multiple axial gaps evenly distributed along the circumference at its contraction end.

7. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The motor (26) is fixedly mounted on the side of the base (11).

8. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The slider (29) is mounted on the mounting plate (25).

9. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The spring rod (35) is mounted on the mounting plate (25).

10. The drilling device for connecting holes of polytetrafluoroethylene pipe fittings assembled on a machine tool as described in claim 1, characterized in that, The output end of the second air pump (36) is mounted on the mounting bracket (13), and the end of the roller shutter protective cover (37) away from the mounting bracket (13) is mounted on the base (11).

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