Compensation method for influence of numerical control machining environment temperature on workpiece size

Abstract

A compensation method for the influence of the numerical control machining environment temperature on the workpiece size comprises the following steps that a temperature monitoring module is deployed in a numerical control center, machining environment temperature data are monitored and obtained, and the machining environment temperature data are transmitted to the numerical control center; meanwhile, a part machining temperature threshold value is set in the numerical control center; during machining, the numerical control center obtains the machining environment temperature data from the temperature monitoring module in real time and compares the machining environment temperature data with the set part machining temperature threshold value to obtain a temperature difference value; according to the specific thermal expansion coefficient of the part material, the numerical control center calculates the scaling size of the part; a machining program adaptive to the current working procedure is loaded, the scaling size is corrected and compensated, the machining program is removed from the numerical control center after the machining working procedure is completed, circulation is conducted till all the machining working procedures on the machine tool are completed, the influence of the machining environment temperature on the part machining size in the numerical control machining process is effectively avoided, and the machining efficiency is improved. The use cost is low, the application range is wide, and the product percent of pass is high.

Description

Technical Field

[0001] The invention belongs to the technical field of numerical control machining, and in particular relates to a method for compensating the influence of the ambient temperature on the size of a workpiece during numerical control machining. Background Art

[0002] In the machining industry, CNC machine tools are the carriers of advanced manufacturing technologies and a crucial production tool for the equipment industry. They are primarily used in aerospace, medical, and shipbuilding industries. Technological advancements are driving increasing demand for specialized, complex, and high-quality parts, and the requirements for CNC machine tools are also rising. Simultaneously, CNC machine tools are developing towards higher efficiency, digitalization, and intelligence. However, fluctuations in cutting heat and ambient temperature during CNC machining can cause parts to expand and contract during machining, leading to dimensional fluctuations. This is particularly severe for magnesium and aluminum alloys, which can lead to quality issues.

[0003] In practice, the solution to the above technical problems is usually for workers to use experience-based estimates to manually compensate or make real-time measurements during the processing process. Although this can ensure that the dimensions on the processing site are correct, the dimensions may be out of tolerance once the ambient temperature changes. In addition, such operations are prone to quality problems due to estimation errors or measurement errors, affecting product yield and processing efficiency. Alternatively, air conditioning is installed in the processing workshop and a constant temperature device is installed for the processing coolant. However, this is relatively expensive and many factories do not have the conditions. This causes the dimensions of the processed workpiece to be unstable, affecting the product qualification rate. The existing technology solves the above technical problems by making corrections based on the thermal expansion coefficient of the parts and adding cutting fluid. However, the sampling and calculation processes are complicated and require the use of a specific system for processing and correction. This is expensive and has a limited scope of application.

[0004] For example, the patent document with publication number CN119937457A specifically discloses a CNC lathe processing system and method based on precision correction, which relates to the field of CNC machine tool management technology. It uses a specific CNC lathe processing system based on precision correction for processing, and sets up several temperature sensors on the lathe to collect temperature records of several working areas of the lathe, perform numerical sampling on the temperature records, calculate the predicted temperature of each working area, perform weighted calculation on the predicted temperature to obtain the processing reference temperature of the lathe, obtain the thermal expansion coefficient of the part, and correct the measured dimensions of the part based on the thermal expansion coefficient and the processing reference temperature to reduce the problem of reduced processing accuracy caused by dimensional changes of the part during the processing. However, this technical solution is relatively complex in the process of temperature monitoring, acquisition, prediction and calculation, and requires the use of a supporting specific system to achieve the correction of the measured dimensions of the part. The use and maintenance costs are high, and it is not suitable for the actual situation of most factories.

[0005] Therefore, there is an urgent need to design a technical solution that has a simple correction process, a wide range of applications, low maintenance costs, and can compensate and correct the workpiece size at a specific temperature without the use of a supporting system. Summary of the Invention

[0006] To solve the above technical problems, the present application provides a method for compensating the influence of ambient temperature on workpiece size in CNC machining, comprising the following steps:

[0007] S100, deploying a temperature monitoring module in the CNC center to monitor and obtain processing environment temperature data, and transmitting the processing environment temperature data to the CNC center; and setting a part processing temperature threshold in the CNC center;

[0008] S200, during processing, the CNC center obtains the processing environment temperature data from the temperature monitoring module in real time, and compares it with the set part processing temperature threshold to obtain a temperature difference Δt;

[0009] S300, the CNC center calculates the scaled size of the part based on the temperature difference Δt and a specific thermal expansion coefficient of the part material;

[0010] S400, according to the scaling size, the CNC center loads the processing program adapted to the current process, corrects and compensates the scaling size, removes the processing program from the CNC center after completing the current processing process, enters the next process and loops S200-S400 until all processing processes on the machine tool are completed.

[0011] Furthermore, the part processing temperature threshold is 20°C.

[0012] Furthermore, the temperature monitoring module is realized by connecting the PLC controller of the numerical control center with a temperature detection device, and the temperature detection device is arranged in the machine tool workshop.

[0013] Furthermore, the temperature detection device is a temperature sensor.

[0014] Furthermore, the PLC controller reads the processing environment temperature data in real time through macro variables, and inputs the processing environment temperature data into the CNC center in real time.

[0015] Furthermore, the correction compensation adopts scaling function compensation.

[0016] Furthermore, the material-specific thermal expansion coefficient is obtained from a parameter table of thermal expansion characteristics of different materials.

[0017] Furthermore, the temperature difference Δt is the processing environment temperature minus the part processing temperature threshold.

[0018] Furthermore, the calculation formula for the scaling size of the part is:

[0019] The scaled size of the part = 1 + temperature difference Δt * thermal expansion coefficient.

[0020] The beneficial effects of the present invention are as follows: by deploying a temperature monitoring module in a CNC center, using a built-in PLC controller to connect with a temperature detection device to realize temperature monitoring and acquisition functions, and then calculating the scaled size of the part in the CNC center through the temperature difference Δt between the processing environment temperature and the part processing temperature threshold, as well as the specific thermal expansion coefficient of the part material, the CNC center loads a processing program adapted to the current process, and corrects and compensates for the scaled size. The compensation calculation process is simple, and without the need for an additional supporting compensation system, the problem of thermal expansion and contraction of the processed parts caused by changes in the processing environment temperature during CNC processing, resulting in a difference in the final size of the parts, is effectively solved. No additional use cost is added, the system is applicable to most factories, and the product qualification rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of a method for compensating the effect of ambient temperature on workpiece size in numerical control machining, provided by an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the logic principle of a method for compensating the influence of the ambient temperature of a numerically controlled machining process on the size of a workpiece provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0024] An embodiment of the present invention provides a method for compensating for the effect of ambient temperature on workpiece dimensions during CNC machining. This method addresses the technical problem of dimensional changes in the workpiece caused by thermal expansion and contraction due to ambient temperature fluctuations during CNC machining. The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings.

[0025] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a method for compensating the influence of the ambient temperature of a numerically controlled machining environment on the size of a workpiece, comprising the following steps:

[0026] S100, deploying a temperature monitoring module in a numerical control center to monitor and obtain processing environment temperature data, and transmitting the processing environment temperature data to the numerical control center; and setting a part processing temperature threshold in the numerical control center.

[0027] The part processing temperature threshold is 20°C.

[0028] The temperature monitoring module is realized by connecting the PLC controller of the numerical control center with the temperature detection device, and the temperature detection device is arranged in the machine tool workshop.

[0029] The temperature detection device is a temperature sensor.

[0030] The PLC controller reads the processing environment temperature data in real time through macro variables, and inputs the processing environment temperature data into the numerical control center in real time.

[0031] S200, during processing, the CNC center obtains the processing environment temperature data from the temperature monitoring module in real time, and compares it with the set part processing temperature threshold to obtain a temperature difference Δt;

[0032] The temperature difference Δt is the processing environment temperature minus the part processing temperature threshold.

[0033] S300, the CNC center calculates the scaled size of the part based on the temperature difference Δt and a specific thermal expansion coefficient of the part material;

[0034] The material-specific thermal expansion coefficient is known and can be obtained from a parameter table of thermal expansion characteristics of different materials.

[0035] S400, according to the scaling size, the CNC center loads the processing program adapted to the current process, corrects and compensates the scaling size, removes the processing program from the CNC center after completing the current processing process, enters the next process and loops S200-S400 until all processing processes on the machine tool are completed.

[0036] The correction compensation adopts a scaling function compensation.

[0037] The calculation formula for the scaled size of the part is:

[0038] The scaled size of the part = 1 + temperature difference Δt * thermal expansion coefficient.

[0039] The present invention deploys a temperature monitoring module in a CNC center to monitor the processing environment temperature, obtain the temperature difference Δt between the temperature of the part processing process and the part processing temperature threshold, calculate the scaled size of the part according to the specific thermal expansion coefficient of the material, and finally load the processing program adapted to the current process according to the scaled size of the part, correct and compensate for the scaled size. After completing the current processing step, the processing program is removed from the CNC center and enters the next step. The cycle is repeated. The changes in the size of the workpiece caused by the change in the processing environment temperature in all processing steps on the machine tool can be corrected and compensated, thereby solving the influence of the processing environment temperature on the processing size, thereby improving the processing quality and efficiency.

[0040] The above disclosure is only a specific embodiment of the present invention, but the present invention is not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A method for compensating the effect of ambient temperature on workpiece size in numerical control machining, characterized in that: The following steps are involved: S100, deploying a temperature monitoring module in the CNC center to monitor and obtain processing environment temperature data, and transmitting the processing environment temperature data to the CNC center; and setting a part processing temperature threshold in the CNC center; S200, during processing, the CNC center obtains the processing environment temperature data from the temperature monitoring module in real time, and compares it with the set part processing temperature threshold to obtain a temperature difference Δt; S300, the CNC center calculates the scaled size of the part based on the temperature difference Δt and a specific thermal expansion coefficient of the part material; S400, according to the scaling size, the CNC center loads the processing program adapted to the current process, corrects and compensates the scaling size, removes the processing program from the CNC center after completing the current processing process, enters the next process and loops S200-S400 until all processing processes on the machine tool are completed.

2. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 1, characterized in that: The part processing temperature threshold is 20°C.

3. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 1, characterized in that: The temperature monitoring module is realized by connecting the PLC controller of the numerical control center with the temperature detection device, and the temperature detection device is arranged in the machine tool workshop.

4. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 3, characterized in that: The temperature detection device is a temperature sensor.

5. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 4, characterized in that: The PLC controller reads the processing environment temperature data in real time through macro variables, and inputs the processing environment temperature data into the numerical control center in real time.

6. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 1, characterized in that: The correction compensation adopts a scaling function compensation.

7. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 6, characterized in that: The material-specific thermal expansion coefficient is obtained from a parameter table of thermal expansion characteristics of different materials.

8. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 7, characterized in that: The temperature difference Δt is the processing environment temperature minus the part processing temperature threshold.

9. The method for compensating the effect of ambient temperature on workpiece size in numerical control machining according to claim 8, characterized in that: The calculation formula for the scaled size of the part is: The scaled size of the part = 1 + temperature difference Δt * thermal expansion coefficient.

Images