A Turning Positioning Method for Shaft Parts for High-Efficiency and Low-Carbon Machining

Abstract

This invention provides a turning positioning method for shaft parts for efficient and low-carbon machining, comprising the following steps: S1, acquiring lathe information and workpiece information, wherein the lathe information includes the stiffness K of the lathe headstock. 头架 Workpiece information includes the stiffness K of the workpiece material. 工件 The invention employs the following methods: S1) Obtain the Young's modulus E and moment of inertia I of the workpiece material; S2) Obtain the length z of the machining position from the headstock; S3) Establish a mathematical model of the deformation δ at the machining position caused by both lathe deformation and workpiece deformation; S4) Obtain the workpiece overhang length L that minimizes the deformation δ; S5) Obtain the workpiece clamping position. By changing the clamping position, this invention allows machining of shaft-type parts at the location with the least deformation, effectively reducing machining time and achieving high-efficiency machining. Machining at the location with the least deformation also reduces the electrical energy consumed in material cutting, thus achieving carbon reduction.

Description

Technical Field

[0001] This invention relates to the field of machining, and in particular to a turning positioning method for shaft parts for efficient and low-carbon machining. Background Technology

[0002] Shafts are widely used in manufacturing due to their function of supporting and transmitting transmission components, transmitting torque, and bearing loads. Examples include polished rods and ball screws in lathe equipment; crankshafts used in various types of engines in the automotive industry; screws for deploying satellite antennas in the aerospace industry; and drill pipes used in engineering machinery. Currently, the global market size for shafts has reached US$500 billion, and as a global manufacturing center, China's market size for shafts is also continuously expanding, exceeding RMB200 billion.

[0003] With the increasing demand for shaft parts, reducing material waste and manufacturing time is a major task for companies to improve their competitiveness. In recent years, many domestic and foreign experts and scholars have put forward many fruitful studies on improving the processing efficiency of shaft parts. Lin Chunyang et al. studied the optimal process and inspection scheme suitable for slanted shaft parts from the perspective of processing technology, which improved the processing efficiency; Yang Pengwei et al. changed the surface roughness and machining chips by using dry ultrasonic-assisted turning of 304 stainless steel shaft parts, realizing the high efficiency of ultrasonic-assisted turning; Denkena Berend et al. used flow control method to realize the efficient and energy-saving supply of cutting fluid in cutting process from the perspective of cutting fluid; Wang Bing, Tang Chensheng, Liao Miao et al. all proposed methods to improve the processing efficiency of workpieces of different materials such as titanium alloys, aluminum alloys, and nickel-based high-temperature alloys from the perspective of materials. In addition, there are patent studies on improving workpiece processing efficiency. Wu Guangwu et al. proposed a workpiece fixing device for lathes to improve processing efficiency (Chinese Patent: CN201620304571.9), Wang Jianbin et al. proposed a workpiece clamping device to improve processing efficiency (Chinese Patent: CN202123301265.X), and Wan Zhiqiang et al. established a multi-dimensional index calculation model for processing procedures, enabling multi-process processing systems to achieve the processing expectations of the workpiece to be processed, making full use of the calculation data of processing indicators to improve processing efficiency (Chinese Patent: CN202310304776.1).

[0004] The aforementioned studies almost exclusively focus on machining processes, materials, and cutting fluids to achieve efficient machining of shaft parts. Very few studies optimize machining from the perspective of workpiece clamping position, i.e., positioning angle. Currently, workpiece positioning is often based on experience. For example, when using a three-jaw chuck for turning, if the workpiece diameter is less than or equal to 30mm, its overhang length should not exceed 5 times the diameter; if the workpiece diameter is greater than 30mm, the overhang length should not exceed 3 times the diameter. This approach does not adequately consider high-efficiency and energy-saving machining. Therefore, this patent analyzes the deformation of shaft parts and lathes during machining, focusing on optimizing the clamping position of shaft parts for high efficiency and energy saving. This approach has broad application prospects. Summary of the Invention

[0005] In order to achieve high efficiency and energy saving during the turning of shaft parts, this invention provides a turning positioning method for shaft parts with high efficiency and low carbon emissions. This method is based on the deformation of the machining point of the shaft part.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for positioning shaft parts during turning, aimed at high-efficiency and low-carbon machining, includes the following steps:

[0008] S1. Obtain lathe information and workpiece information. The lathe information includes the stiffness K of the lathe headstock. 头架 Workpiece information includes the stiffness K of the workpiece material. 工件 Young's modulus E and moment of inertia I of the workpiece material;

[0009] S2. Obtain the length z of the processing position from the head frame;

[0010] S3. Establish a mathematical model for the deformation δ at the machining location caused by the combined deformation of the lathe and the workpiece.

[0011] S4. Obtain the workpiece overhang length L value that minimizes the deformation δ.

[0012] S5. Obtain the clamping position of the workpiece.

[0013] As a preferred embodiment of the present invention, the mathematical model of the deformation amount δ at the machining position in step S3 includes the deformation amount at the machining position caused by the deformation of the lathe and the deformation amount caused by the force at the machining position.

[0014] The deformation at the machining location caused by machine tool deformation is mainly due to the displacement of the lathe headstock and the workpiece at a distance from the three-jaw chuck. The deformation amount function is as follows:

[0015]

[0016] In the formula, δ 机床 F represents the amount of deformation at the machining location caused by lathe deformation. p K is the radial cutting force. 头架 For the rigidity of the lathe headstock, K 工件 Let z be the workpiece stiffness, z be the distance from the machining position to the headstock, and L be the workpiece overhang length.

[0017] The deformation of the workpiece at the machining location caused by force is calculated using the cantilever beam formula in mechanics of materials. The deformation function is as follows:

[0018]

[0019] In the formula, δ 工件 F represents the deformation caused by stress at the machining point. p denoted as radial cutting force, z as the distance from the machining position to the headstock, E as the Young's modulus of the workpiece material, and I as the moment of inertia of the cross section.

[0020] That is, the mathematical model for the deformation δ at the processing location in step S3 is as follows:

[0021]

[0022] In the formula, δ represents the deformation at the machining location, and F p K is the radial cutting force. 头架 For the rigidity of the lathe headstock, K 工件 Let z be the stiffness of the workpiece, z be the distance from the machining position to the headstock, L be the overhang length of the workpiece, E be the Young's modulus of the workpiece material, and I be the moment of inertia of the cross section.

[0023] As a preferred embodiment of the present invention, the process of obtaining the minimum deformation amount δ in step S4 is to perform mathematical differentiation of the workpiece overhang length L on the mathematical model of δ in step S2, and obtain the calculation model of the workpiece overhang length L value when the deformation amount δ is minimized as shown in the following formula:

[0024]

[0025] In the formula, L is the overhang length of the workpiece, and K 头架 For the rigidity of the lathe headstock, K 工件 Let z be the stiffness of the workpiece, and z be the length of the machining position from the headstock.

[0026] In a preferred embodiment of the present invention, the clamping position in step S5 is the total length of the workpiece minus the overhang length.

[0027] Compared with existing technologies, the present invention has the following advantages:

[0028] 1. By changing the clamping position, the present invention can perform machining at the position where the deformation of shaft parts is minimal, which can effectively reduce machining time and achieve the goal of high-efficiency machining.

[0029] 2. This invention processes shaft parts at the location with the least deformation, reducing the electrical energy consumed in material cutting and achieving the goal of carbon reduction. Attached Figure Description

[0030] Figure 1 This is a schematic diagram for determining the optimal clamping position of shaft-type parts.

[0031] Figure 2 This is a schematic diagram of the deformation of shaft-type parts. Detailed Implementation

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] A method for positioning shaft parts during turning, aimed at high-efficiency and low-carbon machining, includes the following steps:

[0034] S1. Obtain lathe information and workpiece information. The lathe information includes the stiffness K of the lathe headstock. 头架 Workpiece information includes the workpiece material stiffness K. 工件 The Young's modulus E and moment of inertia I of the workpiece material;

[0035] S2. Obtain the length z of the processing position from the head frame;

[0036] S3. Establish a mathematical model for the deformation δ at the machining location caused by the combined deformation of the lathe and the workpiece.

[0037] S4. Obtain the workpiece overhang length L value that minimizes the deformation δ.

[0038] S5. Obtain the clamping position of the workpiece.

[0039] In a specific embodiment, the stiffness of the lathe headstock in step S1 is 6×10. 4 N / mm. The material stiffness at the machining point is 5×10 N / mm. 4 N / mm, Young's modulus E of the material is 5×10⁻⁶. 5 N / mm 2 and moment of inertia of cross section

[0040] In a specific embodiment, the processing position z is determined to be 100mm in step S2.

[0041] In a specific embodiment, the mathematical model describing the deformation δ at the workpiece machining position in step S3 is calculated based on the definition of stiffness. For shaft-type parts clamped in a three-jaw chuck, the optimal clamping position for the shaft-type parts is determined as follows: Figure 1 As shown, at point B on the workpiece, F can be obtained based on the torque. p (Lz)=F A L, then Similarly, at point A on the workpiece, F can be obtained from the torque. B L = F p z, then According to the definition of stiffness The deformation at point A of the workpiece can be obtained as follows: Similarly, the deformation at point B of the workpiece is

[0042]

[0043] Deformation at the machining location caused by machine tool deformation, such as Figure 2 Let AB be the workpiece axis, and A'B' be the workpiece axis after deformation under force. Based on the principle of triangle similarity, the deformation at the machining point is as follows:

[0044]

[0045] After processing, the deformation at the machining location caused by lathe deformation can be obtained as follows:

[0046]

[0047] In the formula, δ 机床 F represents the amount of deformation at the machining location caused by lathe deformation. p K is the radial cutting force. 头架 For the rigidity of the lathe headstock, K 工件 Let z be the workpiece stiffness, z be the distance from the machining position to the headstock, and L be the workpiece overhang length.

[0048] The deformation of the workpiece caused by the force at the machining position is calculated using the cantilever beam formula in mechanics of materials. The deformation function is as follows:

[0049]

[0050] In the formula, δ 工件 F represents the deformation caused by stress at the machining point. p denoted as radial cutting force, z as the distance from the machining position to the headstock, E as the Young's modulus of the workpiece material, and I as the moment of inertia of the cross section.

[0051] In summary, the deformation function of the workpiece is as follows:

[0052]

[0053] In a specific embodiment, the process of obtaining the minimum deformation amount δ in step S4 involves mathematically differentiating the workpiece overhang length L from the mathematical model of δ in step S2, and obtaining the workpiece overhang length L value that minimizes the deformation amount δ as shown in the following formula:

[0054]

[0055] make but,

[0056]

[0057] In a specific embodiment, in step S5, the overhang length is known to be 220mm, and the shaft-type parts are clamped.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for positioning shaft parts during turning, characterized in that, Includes the following steps: S1. Obtain lathe information and workpiece information. The lathe information includes the rigidity of the lathe headstock. Workpiece information includes the stiffness of the workpiece material. Young's modulus of the workpiece material and moment of inertia of cross section ; S2. Obtain the distance between the processing position and the headframe. ; S3. Establish the deformation at the machining location caused by both lathe deformation and workpiece deformation. Mathematical model; The deformation at the processing location in step S3 The mathematical model is as follows: In the formula, This represents the deformation at the machining location. Radial cutting force, For the rigidity of the lathe headstock, For the stiffness of the workpiece, The distance from the processing position to the headstock. The overhang length of the workpiece. The Young's modulus of the workpiece material. The moment of inertia of the cross section; S4. Obtain the deformation amount. Minimum workpiece overhang length value; The deformation amount in step S4 The minimum acquisition process is step S2. Mathematical model for workpiece overhang length By performing mathematical differentiation, we obtain the deformation amount. Minimum workpiece overhang length The calculation model for the value is shown in the following formula: In the formula, The overhang length of the workpiece. For the rigidity of the lathe headstock, For the stiffness of the workpiece, This refers to the distance between the processing position and the headstock. S5. Obtain the clamping position of the workpiece.

2. The method for positioning shaft parts during turning according to claim 1, characterized in that, In step S5, the clamping position is determined by subtracting the overhang length from the total length of the workpiece.

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