Method for identifying thermal boundary conditions based on boundary topology

Abstract

The present application relates to a kind of based on boundary topology's thermal boundary condition identification method, using thermal boundary detection unit, thermal boundary topology unit, thermal boundary condition identification unit, wherein: thermal boundary detection unit is built into the surface of main shaft system joint surface, the temperature of main shaft system joint surface is collected, the temperature data of main shaft system joint surface collected is used for thermal boundary topology, thermal boundary topology unit determines topology invariant and topological structure according to the temperature data of main shaft system joint surface collected, thermal boundary condition identification unit calculates thermal boundary condition according to topological boundary, and the thermal boundary condition of main shaft system is calculated by identification model, and the calculation result is stored in database for the accurate analysis of main shaft system thermal characteristics.The thermal boundary condition identification method of the present application can not only realize the identification of main shaft system joint surface contact thermal resistance, but also can realize the identification of heat source heat generation and convection heat transfer coefficient in main shaft system, and can be used for the accurate analysis of main shaft system thermal characteristics.

Description

Technical Field

[0001] This invention relates to a precise analysis method for the thermal characteristics of high-speed spindles, and particularly to a method for identifying thermal boundary conditions based on boundary topology. Background Technology

[0002] With the increase in spindle speed and the widespread application of electric spindles in high-speed machine tools, the thermal deformation generated by the high-speed operation of the spindle seriously affects the machining accuracy of the machine tool. Therefore, accurate analysis and control of the thermal characteristics of high-speed spindles is a key technology for improving machine tool accuracy. However, the thermal characteristics of the spindle system are like a "black box," with many thermal boundary conditions that cannot be accurately obtained, limiting the accuracy of thermal characteristic analysis and control. Therefore, solving the problem of accurate analysis and control of thermal characteristics under high-speed, high-efficiency, and high-precision working conditions is a key technology for high-speed spindles, and it is of great significance for improving machining accuracy and lifespan.

[0003] To accurately analyze the thermal characteristics of high-speed spindles, identifying the thermal boundary conditions is crucial. The heat generated by the internal heat source, the convective heat transfer coefficient, and the contact thermal resistance at the interface are three key parameters for thermal characteristic analysis; the accuracy of their identification determines the accuracy of the analysis. Currently, the most typical identification methods include theoretical calculations, experimental measurements, intelligent optimization, and inverse methods. However, due to the complexity of thermal boundary conditions and the limitations of experiments, there is a certain deviation between the identification accuracy and the actual values. Furthermore, the shape, location, and material of the thermal boundary, among other factors, make it difficult to determine the accurate values.

[0004] Therefore, a thermal boundary condition identification method based on boundary topology is proposed. The temperature of the interface of the spindle system is collected in real time by a micro-patch temperature sensor. A homogenization method is adopted, with the interface temperature as the topological invariant, to transform the interface with uneven surface and non-uniform medium into a continuous structure with known material properties, and to determine the material properties, structure and size of the continuum that keep the interface temperature constant. The thermal boundary conditions are identified by homeomorphism mapping and inverse method. Summary of the Invention

[0005] This invention addresses the problem of thermal boundary condition identification in CNC machine tool spindle systems by proposing a thermal boundary condition identification method based on boundary topology, which can be used to accurately identify the thermal boundary conditions of the spindle system.

[0006] This invention is achieved through the following technical solution:

[0007] A thermal boundary condition identification method based on boundary topology employs a thermal boundary detection unit, a thermal boundary topology unit, and a thermal boundary condition identification unit. The thermal boundary detection unit is embedded in the surface of the spindle system mating surface, collecting the temperature of the mating surface. This temperature data is used for the thermal boundary topology. The thermal boundary topology unit determines topological invariants and topological structure based on the collected temperature data. The thermal boundary condition identification unit calculates the thermal boundary conditions based on the topological boundary and uses an identification model to calculate the thermal boundary conditions of the spindle system. The calculation results are stored in a database for accurate analysis of the spindle system's thermal characteristics.

[0008] Furthermore, the thermal boundary detection unit includes: a miniature patch temperature sensor and a data acquisition system, wherein: the miniature patch temperature sensor is embedded in the surface of the spindle system mating surface to realize real-time measurement of the mating surface temperature, and the measurement result is transmitted to the host computer through the data acquisition system.

[0009] Furthermore, the thermal boundary topological unit includes: topological invariants and topological boundaries, wherein: the topological invariants are composed of the interface temperatures of the identified spindle system mating surface components, and the topological boundaries are formed by using a homogenization method to transform the discontinuous mating surfaces between two spindle system mating components into a structurally continuous continuum while keeping the interface temperatures constant.

[0010] Furthermore, the thermal boundary condition identification unit includes: a contact thermal resistance identification model, a heat flux density identification model, and a convective heat transfer coefficient identification model. The contact thermal resistance identification model identifies the contact thermal resistance of the main shaft system interface using a homeomorphic mapping method based on the structure and material properties of the topological boundary. The heat flux density identification model calculates the heat generated by the internal heat source using an inverse method based on the contact thermal resistance of the main shaft system interface and the interface temperature. The convective heat transfer coefficient identification model inversely calculates the convective heat transfer coefficient based on the heat flux flowing through the component and the interface temperature.

[0011] Furthermore, the thermal boundary detection unit embeds a miniature patch temperature sensor into the interface of the spindle system, transmits the detected interface temperature to the host computer, and plots a temperature distribution map based on the spindle system component structure and interface temperature, forming temperature distribution curves T1T2, T2T3, and T3T. wThe thermal boundary topology element extends the temperature distribution curve T1T2, and draws a line parallel to the X-axis through T3, intersecting the extension of T1T2 at point T3. The length L of T3T3 is measured. Based on the measured length L, the spindle system components are continuously topologically reconstructed. The heat transfer of the topological region L is equivalent to that of the mating surface. The thermal boundary condition identification element calculates the contact thermal resistance of the mating surface using the contact thermal resistance identification model based on the topological boundary L and the material properties of the spindle system components. Based on the contact thermal resistance calculation results and the interface temperature, the heat flux density identification model is used to calculate the heat flux flowing through the mating surface. Based on the heat flux flowing through the mating surface and the interface temperature, the convective heat transfer coefficient identification model is used to calculate the convective heat transfer coefficient. The same method is used to identify the thermal boundary conditions of the remaining mating surfaces of the spindle system, thereby achieving accurate identification of the thermal boundary conditions of the spindle system.

[0012] The beneficial effects of this invention are as follows:

[0013] The thermal boundary condition identification method based on boundary topology of the present invention can not only identify the contact thermal resistance of the spindle system mating surface, but also identify the heat generation and convective heat transfer coefficient of the heat source in the spindle system, and can also be used for accurate analysis of the thermal characteristics of the spindle system. Attached Figure Description

[0014] Figure 1 This is a structural diagram of the thermal boundary acquisition and topology module of the present invention;

[0015] Figure 2 This is a flowchart of the thermal boundary condition identification process of the present invention;

[0016] In the figure: 1. First micro patch temperature sensor, 2. First spindle system assembly, 3. Second micro patch temperature sensor, 4. Mating surface, 5. Third micro patch temperature sensor, 6. Second spindle system assembly, 7. Fourth micro patch temperature sensor, 8. Topological boundary. Detailed Implementation

[0017] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific identification processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0018] like Figure 1As shown, this embodiment discloses a thermal boundary condition identification method based on boundary topology, comprising: a first micro-patch temperature sensor 1, a first spindle system assembly 2, a second micro-patch temperature sensor 3, a mating surface 4, a third micro-patch temperature sensor 5, a second spindle system assembly 6, a fourth micro-patch temperature sensor 7, and a topological boundary 8. The first spindle system assembly 2 and the second spindle system assembly 6 form the mating surface 4. The first and second micro-patch temperature sensors 1 and 3 are embedded in the two surfaces of the first spindle system assembly 2, and the third and fourth micro-patch temperature sensors 5 and 7 are embedded in the two surfaces of the second spindle system assembly 6. The topological boundary 8 is determined by the temperatures measured by the first, second, and third micro-patch temperature sensors 1, 3, and 5.

[0019] like Figure 2 As shown, this embodiment achieves thermal boundary condition identification in the following way:

[0020] Thermal boundary detection unit according to Figure 1 The illustrated embodiment embeds a miniature patch temperature sensor into the interface of the spindle system, transmitting the detected interface temperature to a host computer. Based on the component structure and interface temperature, a temperature distribution map is plotted, forming temperature distribution curves T1T2, T2T3, and T3T. w The thermal boundary topology element extends the temperature distribution curve T1T2, and draws a line parallel to the X-axis through T3, intersecting the extension of T1T2 at point T3. The length L of T3T3 is measured. Based on the measured length L, the main shaft system component 2 is continuously topologically topologically reconstructed. The topological region L is equivalent to the heat transfer at the interface 4. The thermal boundary condition identification element calculates the contact thermal resistance of the interface 4 using the contact thermal resistance identification model based on the topological boundary L and the material properties (thermal conductivity λ) of the main shaft system component 2. Based on the contact thermal resistance calculation results, the interface temperatures T2 and T3, and the interface area A, the heat flux density identification model is used to calculate the heat flux flowing through the interface. Based on the heat flux flowing through the interface and the interface temperature T... w and fluid temperature T ∞ The convective heat transfer coefficient is calculated using a convective heat transfer coefficient identification model. The same method is used to identify the thermal boundary conditions of the remaining mating surfaces of the main shaft system, thereby achieving accurate identification of the thermal boundary conditions of the main shaft system.

[0021] The thermal boundary condition identification based on boundary topology described in this invention can achieve accurate identification of the thermal boundary conditions of the spindle system, ensuring the accuracy of the thermal characteristic analysis of the spindle system, and providing a basis for the thermal optimization design and thermal error control of the spindle system.

[0022] The beneficial effects of the thermal boundary condition identification based on boundary topology of the present invention are: accurate identification of the thermal boundary conditions of the spindle system, providing a basis for thermal optimization design and thermal error control of the spindle system; in addition, the built-in temperature sensor can monitor and analyze the operating status of heat sources in the spindle system in real time, preventing damage to the spindle system caused by overheating of bearings, motors, etc.

Claims

1. A method for identifying thermal boundary conditions based on boundary topology, characterized in that: The system employs a thermal boundary detection unit, a thermal boundary topology unit, and a thermal boundary condition identification unit. The thermal boundary detection unit is embedded in the surface of the spindle system mating surface, collecting the temperature of the mating surface. This temperature data is used for the thermal boundary topology. The thermal boundary topology unit includes topological invariants and topological boundaries. The topological invariants consist of the interface temperatures of the identified spindle system mating surface components. The topological boundaries, while maintaining constant interface temperatures, are topologically transformed from discontinuous mating surfaces between two spindle system components into a structurally continuous continuum using a homogenization method. The thermal boundary topology unit determines the topological invariants and topological structure based on the collected temperature data of the spindle system mating surface. The thermal boundary condition identification unit calculates the thermal boundary conditions based on the topological boundaries and uses an identification model to calculate the thermal boundary conditions of the spindle system. The calculation results are stored in a database for accurate analysis of the spindle system's thermal characteristics.

2. The thermal boundary condition identification method based on boundary topology according to claim 1, characterized in that: The thermal boundary detection unit includes a miniature patch temperature sensor and a data acquisition system. The miniature patch temperature sensor is embedded in the surface of the spindle system mating surface to achieve real-time measurement of the mating surface temperature. The measurement results are transmitted to the host computer through the data acquisition system.

3. The thermal boundary condition identification method based on boundary topology according to claim 1, characterized in that: The thermal boundary condition identification unit includes: a contact thermal resistance identification model, a heat flux density identification model, and a convective heat transfer coefficient identification model. The contact thermal resistance identification model identifies the contact thermal resistance of the main shaft system interface using a homeomorphic mapping method based on the structure and material properties of the topological boundary. The heat flux density identification model calculates the heat generated by the internal heat source using an inverse method based on the contact thermal resistance of the main shaft system interface and the interface temperature. The convective heat transfer coefficient identification model inversely calculates the convective heat transfer coefficient based on the heat flux flowing through the component and the interface temperature.

4. The thermal boundary condition identification method based on boundary topology according to claim 1, characterized in that: The aforementioned thermal boundary detection unit embeds a miniature patch temperature sensor into the spindle system mating surface, and transmits the detected interface temperatures T1, T2, T3, and T4. w Transmitted to the host computer, based on the spindle system component structure and interface temperatures T1, T2, T3, T... w Plot the temperature distribution diagram to form temperature distribution curves T1T2, T2T3, and T3T. w The thermal boundary topology element extends the temperature distribution curve T1T2, and a line parallel to the X-axis is drawn through T3, intersecting the extension of T1T2. Point, measured The length L is used to continuously topologically topologically connect the spindle system components. The heat transfer of the topological region L is equivalent to that of the mating surface. The thermal boundary condition identification unit calculates the contact thermal resistance of the mating surface using the contact thermal resistance identification model based on the topological boundary L and the material properties of the spindle system components. Based on the contact thermal resistance calculation results and the interface temperature, the heat flux density identification model is used to calculate the heat flux flowing through the mating surface. Based on the heat flux flowing through the mating surface and the interface temperature, the convective heat transfer coefficient identification model is used to calculate the convective heat transfer coefficient. The same method is used to identify the thermal boundary conditions of the remaining mating surfaces of the spindle system, thereby achieving accurate identification of the thermal boundary conditions of the spindle system.

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