Polytetrafluoroethylene screw slotting machining method

Abstract

The invention relates to the technical field of screw machining, in particular to a polytetrafluoroethylene screw slotting machining method. The method comprises the steps that according to the specification, size and groove profile requirements of the polytetrafluoroethylene screw, milling parameters are optimized, and the optimized milling parameters reduce the generation of cutting force and heat; and milling and grooving are carried out according to the optimized milling parameters.

Description

Technical Field

[0001] This invention relates to the field of screw processing technology, and in particular to a method for grooving polytetrafluoroethylene screws. Background Technology

[0002] Polytetrafluoroethylene (PTFE) material properties: PTFE possesses excellent chemical stability, corrosion resistance, low coefficient of friction, and good electrical insulation, making it widely used in various fields with stringent material performance requirements. However, its soft texture, low melting point, and high coefficient of thermal expansion pose significant challenges to its processing.

[0003] Existing screw grooving technologies: Currently, conventional metal screw grooving methods mainly include milling, stamping, and laser grooving. Milling utilizes a high-speed rotating milling cutter to cut metal, achieving high machining accuracy. However, for PTFE screws, the high heat generated during milling can easily melt and deform the material, making it difficult to guarantee the accuracy of the groove shape, and the tool wears out quickly. Stamping is efficient, but requires the fabrication of complex molds. For soft materials like PTFE, stamping can easily cause overall screw deformation, failing to meet accuracy requirements. Laser grooving is a non-contact process with a small heat-affected zone, but the equipment cost is high, and the processing efficiency is low, making it uneconomical for mass production. Summary of the Invention

[0004] Purpose of the invention: To provide a grooving method for polytetrafluoroethylene (PTFE) screws, which solves the problems of thermal deformation of PTFE screws, poor grooving accuracy, and high labor intensity in single-piece processing in existing processing methods, and achieves high-precision, high-efficiency, and low-cost grooving processing of PTFE screws.

[0005] Technical solution: A grooving method for polytetrafluoroethylene (PTFE) screws is provided, comprising: Based on the specifications, dimensions, and slot requirements of the PTFE screws, the milling parameters were optimized. The optimized milling parameters reduced the generation of cutting force and heat. Milling and slotting are performed according to the optimized milling parameters.

[0006] Furthermore, the method also includes: During the milling and grooving process, low-temperature cold air is used to simultaneously cool the milling position of the PTFE screw. Furthermore, the optimized milling parameters include: The milling speed is controlled at 2500-3000 r / min, the feed rate is 50-100 mm / min, and the depth of cut is 0.2-0.5 mm.

[0007] Furthermore, the method also includes: Processing, inspection, and compensation.

[0008] Furthermore, the milling tools are made of alloy-coated tools with sharp cutting edges and high wear resistance.

[0009] Furthermore, before milling the groove according to the optimized milling parameters, the method further includes: Specialized tooling is used to position and tighten the PTFE screws during the processing to ensure the accuracy of the slotting position; by measuring the pop-out height of the PTFE screws, multiple PTFE screws are adjusted to a uniform height.

[0010] Furthermore, the specialized tooling includes: a fixing block; The fixing block has a wide through slot and a narrow through slot along its length. Multiple adjusting threaded holes are opened on the common groove wall of the wide and narrow through slots; mounting threaded holes are opened on the non-common groove wall of the narrow through slot, corresponding one-to-one with the adjusting threaded holes; the central axis of the mounting threaded hole is in the same straight line as the central axis of the corresponding adjusting threaded hole; the mounting threaded hole is used to install PTFE screws; the screw of the PTFE screw is exposed in the narrow through slot; the adjusting screw is installed from the wide through slot to the adjusting threaded hole, and the screw of the adjusting screw abuts against the screw of the PTFE screw in the narrow groove, so as to adjust the nuts of all PTFE screws to be in a straight line.

[0011] Furthermore, the diameter of the mounting threaded hole is smaller than the diameter of the adjusting threaded hole.

[0012] Beneficial effects: By using cold air to assist grooving and optimizing milling parameters, the thermal deformation of PTFE screws is effectively reduced, enabling the grooving size accuracy to be controlled within ±0.05mm and the surface roughness Ra to reach 0.8-1.6μm, meeting the requirements for high-precision applications.

[0013] The holding method allows for the processing of multiple parts at once, changing the original method of processing one part at a time. Compared with traditional processing methods, processing efficiency can be increased by 30%-50%, which can meet the needs of large-scale production. Attached Figure Description

[0014] Figure 1 This is a front view of the special tooling.

[0015] Figure 2 This is a side view of a special tooling.

[0016] Figure 3 This is a rear view of the special tooling. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0019] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0021] Existing processing methods for slotting polytetrafluoroethylene (PTFE) screws generally suffer from the following problems: the processing process can easily cause thermal deformation and melting of the PTFE screw material, resulting in out-of-tolerance grooving dimensions, poor surface quality, the ability to process only one product at a time, low processing efficiency, high labor intensity, and inability to meet the needs of large-scale production.

[0022] This invention provides a method for grooving polytetrafluoroethylene (PTFE) screws, comprising: Install the PTFE screw into the M8 threaded hole → Use a depth gauge to measure the screw protrusion height to ensure it is 15mm → Use an M8 screw to fix the PTFE screw from below → Fix the fixture in the designated position on the machine tool table → Run the machine tool program, low temperature cold air cooling assisted grooving → Remove the fixture → Disassemble the PTFE screw → Reinstall the PTFE screw → Run the machine tool program, low temperature cold air cooling assisted grooving (repeat the cycle).

[0023] Cooling-assisted milling and grooving: Low-temperature cold air cooling is used. During the milling and grooving process, compressed air can quickly remove the heat generated by milling, effectively reducing the temperature of the PTFE screw and preventing the material from deforming or melting due to heat.

[0024] Optimize milling parameters: Based on the specifications, dimensions, and slot requirements of the PTFE screws, precisely optimize the milling parameters. Control the milling speed at 2500-3000 r / min, the feed rate at 50-100 mm / min, and the depth of cut at 0.2-0.5 mm. By setting these parameters appropriately, while ensuring machining efficiency, minimize the generation of cutting forces and heat, thereby improving accuracy and surface quality.

[0025] Specific procedures: 1. Preliminary Preparation: Rigorous screening and inspection of the PTFE screw raw materials are conducted to ensure uniform material and absence of impurities. Appropriate cutting tools are selected based on the screw specifications and grooving requirements, such as alloy-coated tools with sharp cutting edges and high wear resistance. Tool selection must be precisely matched to the width and depth of the groove and the screw size; for example, for narrower grooves, a small-diameter end mill is used to ensure machining accuracy. Simultaneously, the machining equipment undergoes comprehensive debugging and calibration to ensure that the accuracy and stability of all equipment movements meet the machining requirements, and reasonable initial values ​​for machining parameters are set.

[0026] 2. Positioning and clamping: Specialized high-precision positioning fixtures are designed and used, such as... Figure 1-3 As shown, the positioning surfaces and threaded holes on the fixture are used to accurately determine the position of the PTFE screws during processing, ensuring the accuracy of the slotting position. The 13 PTFE screws were adjusted to a uniform height by measuring the PTFE ejection height. An elastic positioning device, such as for nylon screws or PTFE screws, is used to ensure sufficient clamping force while avoiding screw deformation due to over-tightening, thus ensuring both secure screw fixing and preventing damage.

[0027] 3. Machining: A medium-to-high-speed cutting process is employed. Based on the screw's material and size, the cutting speed is controlled at 2500-3000 r / min to reduce heat generation and minimize the risk of material deformation. The cutting speed is determined by considering material hardness, tool durability, and machining accuracy requirements, and the optimal speed value is obtained through multiple trials. A smaller feed rate is selected, generally controlled at 50-100 mm / min, to ensure smooth cutting and improve the surface quality of the groove wall. Feed rate adjustments need to be optimized based on changes in cutting force and tool wear to guarantee machining quality. The depth of cut is rationally determined according to the required grooving depth, controlled at 0.2-0.5 mm per cut, performed in multiple passes to ensure grooving accuracy. The depth of cut setting must consider tool rigidity, machine tool power, and material machinability to avoid tool damage or decreased machining accuracy due to excessive depth of cut. During the cutting process, cold air cooling is used to assist in grooving. The compressed air is directed towards the cutting part of the tool. By cooling the tool during the cutting process, it can also quickly remove the heat and debris generated during milling, effectively reducing the temperature of the PTFE screw and preventing the material from deforming or melting due to heat.

[0028] 4. Processing Inspection and Compensation: During the processing, the processed PTFE screws are inspected using high-precision measuring instruments. The inspection results are compared with the process parameters. If any deviation in processing accuracy is found, the position of the tool and processing parameters are adjusted and compensated in a timely manner to ensure that the grooving size accuracy is always controlled within ±0.05mm.

Claims

1. A method for grooving polytetrafluoroethylene screws, characterized in that, include: Based on the specifications, dimensions, and slot requirements of the PTFE screws, the milling parameters were optimized. The optimized milling parameters reduced the generation of cutting force and heat. Milling and slotting are performed according to the optimized milling parameters.

2. The method according to claim 1, characterized in that, The method further includes: During the milling and grooving process, low-temperature cold air is used to simultaneously cool the milling position of the PTFE screw.

3. The method according to claim 1, characterized in that, The optimized milling parameters include: The milling speed is controlled at 2500-3000 r / min, the feed rate is 50-100 mm / min, and the depth of cut is 0.2-0.5 mm.

4. The method according to claim 1, characterized in that, The method further includes: Processing, inspection, and compensation.

5. The method according to claim 1, characterized in that, The milling cutters are made of alloy-coated tools with sharp cutting edges and high wear resistance.

6. The method according to claim 1, characterized in that, Before milling the slot according to the optimized milling parameters, the method further includes: Specialized tooling is used to position and tighten the PTFE screws during the processing to ensure the accuracy of the slotting position; by measuring the pop-out height of the PTFE screws, multiple PTFE screws are adjusted to a uniform height.

7. The method according to claim 1, characterized in that, Specialized tooling includes: a fixing block; The fixing block has a wide through slot and a narrow through slot along its length. Multiple adjusting threaded holes are opened on the common groove wall of the wide and narrow through slots; mounting threaded holes are opened on the non-common groove wall of the narrow through slot, corresponding one-to-one with the adjusting threaded holes; the central axis of the mounting threaded hole is in the same straight line as the central axis of the corresponding adjusting threaded hole; the mounting threaded hole is used to install PTFE screws; the screw of the PTFE screw is exposed in the narrow through slot; the adjusting screw is installed from the wide through slot to the adjusting threaded hole, and the screw of the adjusting screw abuts against the screw of the PTFE screw in the narrow groove, so as to adjust the nuts of all PTFE screws to be in a straight line.

8. The method according to claim 7, characterized in that, The diameter of the mounting threaded hole is smaller than the diameter of the adjusting threaded hole.

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