Non-metallic thin gasket turning method

Abstract

The application provides a non-metallic thin gasket turning processing method and relates to the technical field of machining. The non-metallic thin gasket turning processing method adopts the processing mode of rough turning, semi-precision turning and precision turning, and a heat treatment process is carried out in the machining process to remove the internal stress of a workpiece. The specific turning precision processing steps are as follows: step one, rough and precision turning of a phi 46mm inner hole, rough and semi-precision turning of two end faces, leaving proper precision processing allowance, and leaving proper precision processing allowance for a 15mm step surface; step two, semi-precision turning of a R17Omm outer circle, leaving proper precision processing allowance; step three, turning the small end face, the phi 17mm outer circle inner hole and the large end face; step four, precision turning of a phi 10mm inner hole and a 15mm small step surface; and step five, precision turning of the shape to meet the size requirement. Through reasonable selection of clamping methods, design of special spinning device tooling and reverse turning tools, the product quality is finally ensured, the production efficiency is improved, and the cost of enterprises is saved.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically to a method for turning non-metallic thin gaskets. Background Technology

[0002] Non-metallic (non-ferrous metal) thin shim parts are rotating parts made of aluminum bronze, grade QAL9-4. These thin shim parts have a thickness of 2.89mm, relatively poor rigidity, and high precision requirements. Improper workpiece clamping using traditional clamping processes can lead to workpiece deformation during machining, affecting its dimensional and shape accuracy. The cutting heat generated during machining can also cause thermal deformation, making it difficult to control workpiece dimensions. Furthermore, under cutting forces, especially when using a cut-off tool, the geometry of the cut-off tool can easily cause vibration and deformation during machining, particularly resulting in a convex-concave shape on one side and a concave shape on the other, affecting the workpiece's dimensional accuracy, shape accuracy, positional accuracy, and surface roughness.

[0003] These parts are made of non-ferrous metals and cannot be clamped and machined using a magnetic chuck on a surface grinder. The parts require very high geometric precision; the coaxiality of the inner hole (φ44.96mm) to the outer diameter (φ70mm) must be 0.002mm, and the parallelism and flatness of the end faces (both 0.002mm and 0.002mm respectively) are key controllable factors during machining. This part is a consumable component, with 200 pieces processed per batch. Due to its high precision requirements and thin-walled nature, it is highly susceptible to deformation. Therefore, a non-metallic thin-walled gasket turning method is urgently needed to solve these problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a turning method for non-metallic thin gaskets, effectively solving the workpiece deformation problem and ensuring the shape and positional accuracy of the parts. The invention specifically analyzes the structural characteristics and machining difficulties of non-metallic (non-ferrous metal) thin gasket parts. By developing reasonable process routes and machining clamping schemes, and optimizing cutting parameters and tool cutting paths, the pass rate and productivity of parts can be improved, which has significant implications for improving product quality.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for machining non-metallic thin gaskets, employing roughing, semi-finishing, and finishing machining processes, including a heat treatment step during machining to remove internal stress in the workpiece. The specific finishing machining steps are as follows:

[0006] Step 1: Rough and finish machine the φ46mm inner hole, rough and semi-finish machine both end faces, leaving appropriate finishing allowance, and leave appropriate finishing allowance for the 15mm stepped surface;

[0007] Step 2: Semi-finish the outer diameter to R170mm, leaving an appropriate finishing allowance;

[0008] Step 3: Turn the machine around and perform semi-finishing of the small end face, the φ17mm outer diameter inner hole, and the large end face;

[0009] Step 4: Finish machining of the φ10mm inner hole and the 15mm small step surface;

[0010] Step 5: Finish the shape to meet dimensional requirements.

[0011] Preferably, the workpiece is a thin gasket-type part made of 2A12 aluminum alloy, and the finishing process is performed using a high-precision CNC lathe.

[0012] Preferably, in the turning and finishing step, a spinning device fixture is used. The fixture has through holes in both the axial and radial directions. The fixture has two sets of end face grooves in the axial direction and a 3mm inner cavity reserved on one side in the radial direction. After the workpiece is clamped, it is positioned by the φ46mm outer circle of the fixture and its left end face. The φ46mm outer circle of the fixture is turned in conjunction with the inner hole of the workpiece, and the clearance is controlled within 0.005mm.

[0013] Preferably, the spinning device fixture includes a T-shaped shaft a, a T-shaped shaft b, bearings, a fixture, jaws, and a chuck. The chuck is provided with jaws, and the fixture is installed on the inner side of the jaws. A workpiece is provided on one side of the fixture, and one side of the workpiece is connected to two bearings. The two bearings are respectively fixed at both ends of the T-shaped shaft b. The middle part of the T-shaped shaft b is fixed to one end of the T-shaped shaft a, and the other end of the T-shaped shaft a is fixed to the output end of the spinning machine.

[0014] Preferably, in the turning finishing step, a special reverse turning tool is used to machine the small φ15mm inner hole small step surface and the small φ5mm inner hole small step surface of the workpiece.

[0015] Preferably, the reverse cutting tool includes a cutting head and a tool holder, the cutting head is fixed to one end of the tool holder, and the cutting head is... Figure 3 As shown in the figure, the front cutting face of the cutter head is 3°, the radius of the cutting tip arc is 0.3mm, and the main rear cutting face of the cutter head is 5°.

[0016] This invention provides a method for machining non-metallic thin gaskets. It has the following advantages:

[0017] 1. By rationally selecting clamping methods and designing dedicated spinning device tooling and reverse cutting tool, this invention ultimately ensures product quality and improves production efficiency, saving costs for enterprises.

[0018] 2. This invention employs roughing, semi-finishing, and finishing machining methods, performs heat treatment during the machining process to remove internal stress in the workpiece, uses a spinning device for workpiece clamping, and designs a special reverse turning tool to machine the φ5mm small step surface of the inner hole according to the material and characteristics of the part. This ensures that there is no interference during machining, smooth chip removal, and that the tool is sharp and has sufficient rigidity and deformation, thereby improving the pass rate and productivity of the parts and improving product quality. Attached Figure Description

[0019] Figure 1 This is a schematic cross-sectional view of the tooling of the spinning device of the present invention;

[0020] Figure 2 This is a three-dimensional schematic diagram of the spinning device tooling of the present invention;

[0021] Figure 3 This is a schematic diagram of the reverse cutting tool of the present invention;

[0022] Figure 4 This is a schematic diagram of the method flow of the present invention.

[0023] Among them, 1. T-spindle a; 2. Bearing; 3. T-spindle b; 4. Workpiece; 5. Tooling; 6. Clamp; 7. Chuck; 8. Lathe tool. Detailed Implementation

[0024] 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, and 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.

[0025] Example:

[0026] like Figure 1-4 As shown, this embodiment of the invention provides a method for machining non-metallic thin gaskets, employing roughing, semi-finishing, and finishing processes. A heat treatment step is performed during the machining process to remove internal stress from the workpiece. The specific machining steps are as follows:

[0027] Step 1: Rough and finish machine the φ46mm inner hole, rough and semi-finish machine both end faces, leaving appropriate finishing allowance, and leave appropriate finishing allowance for the 15mm stepped surface;

[0028] Step 2: Semi-finish the outer diameter to R170mm, leaving an appropriate finishing allowance;

[0029] Step 3: Turn the machine around and perform semi-finishing of the small end face, the φ17mm outer diameter inner hole, and the large end face;

[0030] Step 4: Finish machining of the φ10mm inner hole and the 15mm small step surface;

[0031] Step 5: Finish the shape to meet dimensional requirements.

[0032] It effectively solves the problem of workpiece deformation, ensures the shape and position accuracy of parts, optimizes cutting parameters and tool cutting paths, and can improve the pass rate and productivity of parts, which has great significance for improving product quality.

[0033] In one specific embodiment, the workpiece is a thin gasket-type part made of 2A12 aluminum alloy. During processing, based on the characteristics of the part and the accuracy requirements, a high-precision CNC lathe is preferred for finishing.

[0034] The workpiece is greatly affected by temperature during the machining of 2A12 aluminum alloy. Conventional clamping methods (such as self-centering chucks, mandrels, etc.) can easily lead to workpiece deformation, making clamping and machining inconvenient and unable to guarantee accuracy. Using a spinning device for clamping results in less clamping force, higher clamping accuracy, and convenient loading and unloading.

[0035] In one specific embodiment, during the finishing turning step, a spinning device fixture is used to clamp the workpiece. To ensure that the workpiece is securely clamped in front of the spinning device, the spinning device fixture must have sufficient space. The fixture has through holes in both the axial and radial directions. The fixture has two sets of end face grooves in the axial direction and a 3mm inner cavity reserved on one side in the radial direction. After the workpiece is clamped, it is positioned by the φ46mm outer circle of the fixture and its left end face. The φ46mm outer circle of the fixture is machined in conjunction with the inner hole of the workpiece, and the clearance is controlled within 0.005mm to ensure accurate positioning during repeated clamping and easy alignment.

[0036] In one specific implementation, reference is made to... Figure 1-2 As shown, the spinning device fixture includes a T-shaft a1, a T-shaft b3, bearings 2, fixture 5, jaws 6, and a chuck 7. The chuck 7 has jaws 6, and fixture 5 is mounted on the inner side of the jaws 6. A workpiece 4 is placed on one side of fixture 5, and one side of workpiece 4 is connected to two bearings 2. The two bearings 2 are fixed to both ends of the T-shaft b3, and the middle of the T-shaft b3 is fixed to one end of the T-shaft a1. The other end of the T-shaft a1 is fixed to the output end of the spinning machine. Using this spinning device fixture for clamping results in low clamping force, high clamping accuracy, and convenient loading and unloading.

[0037] In one specific implementation, due to the extremely high geometric accuracy requirements of the workpiece, the parallelism of its two end faces is 0.002mm, and the φ44.96mm inner hole needs accurate positioning and easy alignment. The runout of the 15mm small step surface of the hole and the R170mm outer circle relative to the φ10mm inner hole is 0.002mm. The challenge with the φ15mm inner hole's small step surface and the outer circle and small end face is that if a double clamping is used, it is difficult to guarantee the required machining accuracy, while a single clamping operation lacks suitable machining tools for machining the φ5mm inner hole's small step surface. After analysis, the most reasonable choice is to machine the φ10mm inner hole and all external shapes under multiple clamping operations, and design a special reverse cutting tool to machine the small φ15mm inner hole's small step surface. Based on the part's material and characteristics, a special reverse cutting tool is designed to machine the φ5mm inner hole's small step surface, such as... Figure 3 The image shows a reverse lathe tool, which must ensure that there is no interference during machining, smooth chip removal, and that the tool is sharp and has sufficient rigidity for deformation.

[0038] refer to Figure 3 As shown, in the finishing turning process, a special reverse turning tool is used to machine the small step surface of the small φ15mm inner hole and the small step surface of the φ5mm inner hole.

[0039] In one specific embodiment, the reverse turning tool includes a cutting head and a tool holder, the cutting head being fixed to one end of the tool holder, and the cutting head being... Figure 3 As shown in the figure, the rake face of the cutter head is 3°, the radius of the cutter tip arc is 0.3mm, and the main flank face of the cutter head is 5°.

[0040] In one specific implementation, a tool with a large rake angle, small tip radius, and relatively sharpness is selected, along with reasonable cutting parameters, for finishing. When finishing the φ46mm inner hole, the consistency of part dimensions must be ensured to guarantee the consistency of the fit clearance between the hole and the tooling positioning step when the workpiece is turned around for machining, so as to facilitate accurate positioning and clamping. The clamping force of the tooling should be adjusted appropriately to ensure that the workpiece is securely clamped without causing the workpiece to move or deviate.

[0041] This paper focuses on the machining of non-metallic (non-ferrous metal) thin gasket parts. It analyzes the structural characteristics and machining difficulties of thin gasket parts in detail. By formulating reasonable process routes and machining clamping schemes, and optimizing cutting parameters and tool cutting paths, the deformation problem of workpieces is effectively solved, ensuring the shape accuracy and positional accuracy of parts. This can improve the pass rate and productivity of parts and has great significance for improving product quality.

[0042] Thin-walled gaskets are characterized by their thin walls, poor rigidity, and extremely high precision requirements. Furthermore, they cannot be machined using general-purpose precision machining tools such as magnetic chucks on surface grinders. All of these factors undoubtedly increase the difficulty of workpiece processing and manufacturing costs. This invention, through the rational selection of clamping methods and the design of a dedicated spinning device and reverse cutting tool, ultimately ensures product quality and improves production efficiency, saving costs for enterprises.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for machining non-metallic thin gaskets, characterized in that: The machining process employs roughing, semi-finishing, and finishing turning, with heat treatment performed during the process to relieve internal stress in the workpiece. The specific turning and finishing steps are as follows: Step 1: Rough and finish machine the φ46mm inner hole, rough and semi-finish machine the two end faces, leaving an appropriate finishing allowance, and leave an appropriate finishing allowance for the φ15mm small step surface; Step 2: Semi-finish the outer diameter to R170mm, leaving an appropriate finishing allowance; Step 3: Turn the machine around and perform semi-finishing of the small end face, the φ17mm outer diameter inner hole, and the large end face; Step 4: Finish machining of the φ10mm inner hole and the φ15mm small stepped surface; Step 5: Finish the shape to meet dimensional requirements; In the turning and finishing step, a spinning device fixture is used. The fixture has through holes in both the axial and radial directions. The fixture has two sets of end face grooves in the axial direction and a 3mm inner cavity reserved on one side in the radial direction. After the workpiece is clamped, it is positioned by the φ46mm outer circle of the fixture and its left end face. The φ46mm outer circle of the fixture is turned in conjunction with the inner hole of the workpiece, and the clearance is controlled within 0.005mm. The spinning device fixture includes a T-shaped shaft a, a T-shaped shaft b, bearings, a fixture, jaws, and a chuck. The chuck is equipped with jaws, and the fixture is installed on the inner side of the jaws. A workpiece is placed on one side of the fixture, and one side of the workpiece is connected to two bearings. The two bearings are respectively fixed at both ends of the T-shaped shaft b. The middle part of the T-shaped shaft b is fixed to one end of the T-shaped shaft a, and the other end of the T-shaped shaft a is fixed to the output end of the spinning machine. In the turning and finishing step, a special reverse turning tool is used to machine the φ15mm small step surface of the inner hole of the workpiece and the φ5mm small step surface of the inner hole. The reverse cutting tool includes a cutting head and a shank. The cutting head is fixed to one end of the shank. The front face of the cutting head is 3°, the radius of the cutting tip arc is 0.3mm, and the main back face of the cutting head is 5°.

2. The method for machining non-metallic thin gaskets according to claim 1, characterized in that: The workpiece is a thin gasket-type part made of 2A12 aluminum alloy, and the finishing process is performed using a high-precision CNC lathe.

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