Thermal compensation device and method for electric spindle of machine tool and numerical control machine tool

Abstract

The invention provides a thermal compensation device and method for an electric spindle of a machine tool and a numerical control machine tool, the thermal compensation device comprises a displacement detection device and a control device, a detection part of the displacement detection device is arranged on a tool handle connected with the spindle, and the detection part of the displacement detection device and a detection surface of the tool handle are arranged at an interval in the vertical direction; the detection part of the displacement detection device is opposite to and parallel to the detection surface of the cutter handle; the displacement detection device is used for detecting the thermal displacement of the main shaft in the vertical direction by detecting the distance change between the detection part of the displacement detection device and the detection surface of the cutter handle; and the control device is connected with the displacement detection device, and the control device is used for acquiring data detected by the displacement detection device and adaptively adjusting the position of the main shaft in the vertical direction according to the data detected by the displacement detection device. The thermal compensation device of the machine tool motorized spindle can effectively solve the technical problems that in the prior art, a thermal compensation device of a machine tool motorized spindle is complex in structure and poor in anti-interference capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tools, and in particular to a thermal compensation device and method for a machine tool electric spindle and a numerically controlled machine tool. Background Art

[0002] CNC machine tools are affected by many factors during the machining process, the most important of which is temperature change. During the operation of the machine tool, factors such as power consumption, mechanical friction and ambient temperature will cause heat to be generated, causing the temperature of the machine tool to change continuously, affecting its accuracy and stability. As the core component of CNC machine tools, the electric spindle is directly related to machining accuracy and efficiency. However, the thermal displacement that occurs during electric spindle machining is mainly reflected at the front end of the tool handle. The tool handle drives the tool to produce upward or downward thermal displacement in the Z-axis direction, thereby affecting the surface machining accuracy of the workpiece. Therefore, it is particularly important to compensate for the thermal error of the machine tool spindle.

[0003] At present, there are two main ways to reduce the thermal error of the electric spindle: thermal error suppression method and thermal error compensation method. The thermal error suppression method relies on improving the structural design of CNC machine tools and other methods of improving hardware or directly realizing temperature control to reduce thermal errors. This method can reduce the temperature rise of heat sources, balance the temperature rise and reduce the thermal deformation of CNC machining devices to a certain extent, but it will increase the cost of structural design and manufacturing. The thermal error compensation method is to obtain the error estimate of CNC machine tools through analytical modeling, and then use different methods to appropriately compensate, eliminate or reduce the error of the system. It is an effective and economical means to improve the machining accuracy of CNC machine tools. Therefore, the thermal error compensation method has become an important research field in modern precision engineering at home and abroad.

[0004] However, the existing thermal error compensation device is mainly implemented by temperature sensors and position sensors, and the temperature sensors and position sensors of the thermal error compensation device are arranged in parallel. Therefore, each temperature sensor and position sensor must be connected to the acquisition controller through a separate connection, resulting in complex wiring after multiple temperature sensors, multiple position sensors and the acquisition control unit are connected. In addition, since the temperature sensor of the thermal error compensation technology uses a thermal resistor or a thermocouple, the output electrical signal is weak, which leads to a decrease in the anti-interference ability of the thermal error compensation device, and the robustness and versatility of the error compensation model are not good enough.

[0005] Therefore, the prior art needs to be further developed. Summary of the invention

[0006] The purpose of the present invention is to overcome the above technical deficiencies and provide a thermal compensation device, method and CNC machine tool for a machine tool electric spindle to solve the technical problems of the thermal compensation device for the machine tool electric spindle in the prior art, which has a complex structure and poor anti-interference ability.

[0007] To achieve the above technical purpose, according to one aspect of the present invention: a thermal compensation device for an electric spindle of a machine tool is provided, comprising: a displacement detection device and a control device, wherein the detection portion of the displacement detection device is arranged on a tool handle connected to the spindle, the detection portion of the displacement detection device and the detection surface of the tool handle are arranged spaced apart in the vertical direction, and the detection portion of the displacement detection device and the detection surface of the tool handle are arranged opposite to and parallel to each other; the displacement detection device detects the thermal displacement of the spindle in the vertical direction by detecting the change in the distance between the detection portion of the displacement detection device and the detection surface of the tool handle; a control device is connected to the displacement detection device, and the control device is used to obtain data detected by the displacement detection device, and to adaptively adjust the position of the spindle in the vertical direction according to the data detected by the displacement detection device to achieve error compensation.

[0008] Furthermore, the thermal compensation device also includes: a fixing device, which is movably mounted on the tool handle in a vertical direction; a mounting surface of the fixing device is arranged opposite to a detection surface of the tool handle; and a detection portion of the displacement detection device is mounted on the mounting surface of the fixing device so as to adjust an initial distance between the detection portion of the displacement detection device and the detection surface of the tool handle by moving the fixing device in a vertical direction.

[0009] Furthermore, a through hole and at least one mounting groove are provided on the mounting surface of the fixing device, the through hole extends in a vertical direction, the axis of the through hole is arranged parallel to the axis of the tool handle, and the fixing device is sleeved on the tool handle through the through hole; at least one mounting groove is arranged at intervals from the through hole, and at least one mounting groove is arranged opposite to the detection surface of the tool handle; the displacement detection device includes at least one coil, and at least one coil forms a detection part of the displacement detection device; the coil and the mounting groove are arranged one-to-one correspondingly, and the coil is installed in the corresponding mounting groove; the coil and the detection surface of the tool handle are arranged opposite to and parallel to each other.

[0010] Furthermore, the thermal compensation device also includes: a potting material, which is poured into the mounting groove to fix the coil in the corresponding mounting groove through the potting material; and / or the tool handle includes a tool handle body and a positioning ring, the positioning ring is sleeved on the tool handle body, the positioning ring is coaxially arranged with the tool handle body and the main shaft respectively, and the bottom end surface of the positioning ring forms a detection surface of the tool handle; the cross-section of the mounting groove is circular, and the distance from the axis of the through hole to the edge of the mounting groove is smaller than the outer diameter of the positioning ring; the wall thickness of the positioning ring is larger than the outer diameter of the coil.

[0011] Furthermore, at least one wire outlet hole is provided on the side wall of the fixing device, and the wire outlet holes are respectively arranged in one-to-one correspondence with the mounting slot and the coil, and the wire outlet hole is connected to the corresponding mounting slot; the displacement detection device also includes: at least one signal line, the signal line is arranged in one-to-one correspondence with the coil, one end of the signal line is connected to the corresponding coil, and the other end of the signal line passes through the mounting slot and the wire outlet hole in sequence and is located on the outside of the fixing device; a processor, the processor is connected to one end of the signal line away from the corresponding coil, the processor receives data detected by the corresponding coil through the signal line; the processor is used to process the data detected by the coil.

[0012] Furthermore, the electric spindle of the machine tool includes a shaft body assembly and a spindle, a placement cavity is provided in the shaft body assembly, and at least part of the spindle is rotatably arranged in the placement cavity; the thermal compensation device also includes: a supporting device, the supporting device is installed on the shaft body assembly; the supporting device is connected to the fixing device, and the fixing device is movably arranged relative to the supporting device.

[0013] Furthermore, the supporting device includes: a first supporting frame and a second supporting frame, the first supporting frame and the second supporting frame are installed on the shaft assembly, the first supporting frame and the second supporting frame are respectively located on both sides of the fixing device, and the first supporting frame and the second supporting frame are arranged opposite to each other; the thermal compensation device also includes: a first connecting rod and a second connecting rod, the first connecting rod and the second connecting rod are coaxially arranged, the first connecting rod and the second connecting rod are respectively installed on the first supporting frame and the second supporting frame in an adjustable manner in the vertical direction, and an end of the first connecting rod away from the first supporting frame and an end of the second connecting rod away from the second supporting frame are both detachably connected to the fixing device; so that when the position of the first connecting rod relative to the first supporting frame and the position of the second connecting rod relative to the second supporting frame are adjusted, the fixing device is driven to move in the vertical direction.

[0014] Furthermore, the first support frame is provided with a plurality of first mounting holes, and each of the first mounting holes is spaced apart in the vertical direction; the second support frame is provided with a plurality of second mounting holes, and each of the second mounting holes is spaced apart in the vertical direction; each first mounting hole is arranged in a one-to-one correspondence with each second mounting hole; wherein, the fixing device is respectively connected to the first support frame and the second support frame by passing one end of the first connecting rod away from the fixing device through any one of the first mounting holes; and one end of the second connecting rod away from the fixing device through the corresponding second mounting hole.

[0015] Furthermore, the first support frame has a first mounting portion and a first connecting portion, the first mounting portion is connected to the first connecting portion, and the first connecting portion is located below the first mounting portion; the first mounting portion is used to be fixedly connected to the shaft assembly; the first connecting portion extends in a vertical direction, and a plurality of first mounting holes are provided on the first connecting portion, and the first mounting holes are spaced apart along the extending direction of the first connecting portion; the second support frame has a second mounting portion and a second connecting portion, the second mounting portion is connected to the second connecting portion, and the second connecting portion is located below the second mounting portion; the second mounting portion is used to be fixedly connected to the shaft assembly; the second connecting portion extends in a vertical direction, and a plurality of second mounting holes are provided on the second connecting portion, and the second mounting holes are spaced apart along the extending direction of the second connecting portion; the first connecting portion and the second connecting portion are arranged opposite to each other.

[0016] According to another aspect of the present invention, a numerically controlled machine tool is provided, comprising: the above-mentioned thermal compensation device.

[0017] According to another aspect of the present invention, a thermal compensation method is provided, which is applied to the thermal compensation device mentioned above; the thermal compensation method comprises: determining the initial output voltage of the displacement detection device before the machine tool is operated ; When the machine tool is running, obtain the current output voltage of the displacement detection device ; According to the current output voltage of the displacement detection device and the initial output voltage of the displacement detection device , adaptively adjust the position of the spindle in the vertical direction to achieve error compensation; where n is the number of detections of the displacement detection device, n≥1.

[0018] Further, according to the current output voltage of the displacement detection device and the initial output voltage of the displacement detection device , adaptively adjusting the position of the spindle in the vertical direction to achieve error compensation method, including: calculating the current output voltage With the initial output voltage The first voltage difference ; To set the absolute value of the first voltage difference The sensitivity of the displacement detection device The first voltage difference is compared and , determine the error compensation direction of the main axis in the vertical direction; according to the absolute value of the first voltage difference The sensitivity of the displacement detection device The comparison result and the determined error compensation direction are used to adjust the position of the spindle in the vertical direction; wherein the sensitivity of the displacement detection device The unit is .

[0019] Further, according to the absolute value of the first voltage difference The sensitivity of the displacement detection device The method for adjusting the position of the spindle in the vertical direction based on the comparison result of the error compensation direction and the determined error compensation direction includes: when 1, and when the error compensation direction of the spindle is determined to be vertically upward, control the spindle to move upward 1 ;when 1, and when the error compensation direction of the spindle is determined to be vertically downward, control the spindle to move downward 1 .

[0020] Further, according to the first voltage difference , a method for determining an error compensation direction of a main axis in a vertical direction, comprising: determining an error compensation direction of a main axis in a vertical direction according to a first voltage difference , judge the thermal displacement direction of the spindle; determine the error compensation direction of the spindle in the vertical direction according to the thermal displacement direction of the spindle; when the thermal displacement direction of the spindle is vertically upward, determine the error compensation direction of the spindle in the vertical direction to be vertically downward; when the thermal displacement direction of the spindle is vertically downward, determine the error compensation direction of the spindle in the vertical direction to be vertically upward.

[0021] Further, according to the first voltage difference , the method for determining the thermal displacement direction of the spindle includes: When , the thermal displacement direction of the main axis is vertically upward; when When , the thermal displacement direction of the main axis is vertically downward.

[0022] Furthermore, the thermal compensation method further includes: determining whether the speed of the spindle is switched; when the speed of the spindle is switched, calculating the next output voltage of the displacement detection device The current output voltage of the displacement detection device The second voltage difference According to the second voltage difference , to determine whether the next output voltage of the displacement detection device As a new initial output voltage of the displacement detection device ; When the next output voltage of the displacement detection device As a new initial output voltage of the displacement detection device When the new initial output voltage As the reference voltage, restart the thermal displacement detection of the spindle, and perform error compensation on the spindle based on the detection results.

[0023] Further, according to the second voltage difference , to determine whether the next output voltage of the displacement detection device As a new initial output voltage of the displacement detection device The method comprises: setting a second voltage difference With preset threshold to compare; when When the displacement detection device outputs the next voltage As a new initial output voltage of the displacement detection device .

[0024] Beneficial effects: The technical solution of the present invention is applied, and the thermal compensation device of the electric spindle of the machine tool provided by the present invention comprises: a displacement detection device and a control device, wherein the displacement detection device has a detection part, and the detection part of the displacement detection device is arranged on the tool handle connected to the spindle, and the detection part of the displacement detection device and the detection surface of the tool handle are arranged at intervals in the vertical direction, and the detection part of the displacement detection device is located below the detection surface of the tool handle. In addition, the detection part of the displacement detection device is arranged opposite to and parallel to the detection surface of the tool handle. The displacement detection device detects the thermal displacement of the spindle in the vertical direction by measuring the change in the distance between its detection part and the detection surface of the tool handle. The control device is connected to the displacement detection device, and the displacement detection device transmits the detected data to the control device. The control device adaptively adjusts the position of the spindle in the vertical direction according to the data detected by the displacement detection device, thereby realizing error compensation. It can be seen that by detecting the thermal displacement of the spindle in the vertical direction in real time through the displacement detection device, and adjusting the position of the spindle in time according to the detection data through the control device, the real-time compensation of the thermal displacement of the spindle can be realized. This mechanism ensures that the tool remains in the correct position, thereby significantly reducing the machining error caused by temperature changes, improving the surface machining accuracy of the workpiece, and shortening the warm-up time of the machine tool, so that the machine tool can enter the machining state faster, saving time and cost. At the same time, by compensating the thermal displacement of the spindle in real time, it can also reduce excessive wear and mechanical stress caused by thermal expansion, thereby extending the service life of the equipment, reducing downtime and rework caused by thermal displacement, and improving overall production efficiency. In addition, the thermal displacement of the spindle is detected by the displacement detection device, and the thermal compensation device reduces unnecessary components and connections, making the overall structure more concise. The displacement detection device is set on the tool handle, which is convenient for installation and debugging, shortening the equipment online time and facilitating later maintenance. Moreover, the device can be flexibly configured according to the needs of different machine tools, improving the adaptability and scalability of the device. In addition, the detection part of the displacement detection device is set parallel to the detection surface of the tool handle, so that the vertical distance between the two can be accurately measured, thereby monitoring the thermal displacement of the spindle in real time. This design reduces the error caused by improper installation angle and ensures the reliability of measurement. Through the direct connection between the control device and the displacement detection device, the complexity of signal transmission is reduced, and the possibility of electromagnetic interference or noise of the signal during transmission is reduced. The control device acquires the data of the displacement detection device in real time, so that the system can react quickly and make adjustments according to the actual thermal displacement, further enhancing the anti-interference ability. In addition, the control device can adapt to changes under various operating conditions and improve the flexibility and accuracy of the system operation. The thermal compensation device of the machine tool electric spindle of the present invention can effectively solve the technical problems of the thermal compensation device of the machine tool electric spindle in the prior art, which has a complex structure and poor anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A schematic structural diagram showing an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention; Figure 2 A schematic structural diagram showing a first viewing angle of a fixing device in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention; Figure 3 A second perspective structural schematic diagram of a fixing device in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention is shown; Figure 4 A schematic structural diagram of a first support frame in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention is shown; Figure 5 A schematic structural diagram of a second support frame in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention is shown; Figure 6 A schematic diagram showing the structure of a tool handle in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention is shown; Figure 7 A schematic diagram showing the structure of a processor in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention is shown; Figure 8 A schematic diagram showing a structure in which a processor in an embodiment of a thermal compensation device for a machine tool electric spindle of the present invention is arranged on the electric spindle; Fig. 9 A schematic flow chart showing an embodiment of a thermal compensation method of the present invention; Fig.10 A diagram showing the relationship between the displacement amount of the displacement detection device and the output voltage of the displacement detection device in an embodiment of the thermal compensation method of the present invention.

[0026] The above drawings include the following reference numerals: 1. displacement detection device; 11. coil; 12. processor; 121. placement bin; 2. fixing device; 20. mounting surface; 21. through hole; 22. mounting slot; 23. wire outlet hole; 24. adjustment slot; 25. connection hole; 3. supporting device; 31. first supporting frame; 310. first mounting hole; 311. first mounting part; 312. first connection part; 313. first opening slot; 32. second supporting frame; 320. second mounting hole; 321. second mounting part; 322. second connection part; 323. second opening slot; 4. first connecting rod; 5. second connecting rod; 100. tool handle; 101. detection surface; 102. tool handle body; 103. positioning ring; 200. shaft assembly; 201. first shaft; 202. second shaft; 203. flange; 300. electric spindle. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0028] See also Figures 1 to 8 As shown, according to an embodiment of the present invention, the present invention provides a thermal compensation device for an electric spindle of a machine tool, comprising: a displacement detection device 1 and a control device, wherein the detection portion of the displacement detection device 1 is arranged on a tool handle 100 connected to the spindle, the detection portion of the displacement detection device 1 and a detection surface 101 of the tool handle 100 are arranged at intervals in the vertical direction, and the detection portion of the displacement detection device 1 and the detection surface 101 of the tool handle 100 are arranged opposite to and in parallel; the displacement detection device 1 detects the thermal displacement of the spindle in the vertical direction by detecting the change in the distance between the detection portion of the displacement detection device 1 and the detection surface 101 of the tool handle 100; the control device is connected to the displacement detection device 1, and the control device is used to obtain data detected by the displacement detection device 1, and to adaptively adjust the position of the spindle in the vertical direction according to the data detected by the displacement detection device 1, so as to achieve error compensation.

[0029] It can be seen that the thermal compensation device of the electric spindle of a machine tool provided by the present invention comprises: a displacement detection device 1 and a control device, wherein the displacement detection device 1 has a detection part, the detection part of the displacement detection device 1 is arranged on a tool handle 100 connected to the spindle, the detection part of the displacement detection device 1 and the detection surface 101 of the tool handle 100 are arranged at intervals in the vertical direction, and the detection part of the displacement detection device 1 is located below the detection surface of the tool handle 100. In addition, the detection part of the displacement detection device 1 is arranged opposite to and parallel to the detection surface 101 of the tool handle 100. The displacement detection device 1 detects the thermal displacement of the spindle in the vertical direction by measuring the change in the distance between its detection part and the detection surface 101 of the tool handle 100. The control device is connected to the displacement detection device 1, and the displacement detection device 1 transmits the detected data to the control device, and the control device adaptively adjusts the position of the spindle in the vertical direction according to the data detected by the displacement detection device 1, thereby realizing error compensation.

[0030] It can be seen that by detecting the thermal displacement of the spindle in the vertical direction in real time through the displacement detection device 1, and adjusting the position of the spindle in time according to the detection data through the control device, the real-time compensation of the thermal displacement of the spindle can be achieved. This mechanism ensures that the tool is kept in the correct position, thereby significantly reducing the processing error caused by temperature change, improving the surface processing accuracy of the workpiece, and shortening the warm-up time of the machine tool, so that the machine tool enters the processing state faster, saving time and cost. At the same time, by compensating the thermal displacement of the spindle in real time, excessive wear and mechanical stress caused by thermal expansion can be reduced, thereby extending the service life of the equipment, reducing downtime and rework caused by thermal displacement, and improving overall production efficiency. In addition, by detecting the thermal displacement of the spindle through the displacement detection device 1, the thermal compensation device reduces unnecessary components and connections, making the overall structure more concise. The displacement detection device 1 is set on the tool handle 100, which is convenient for installation and debugging, shortening the equipment online time, and facilitating later maintenance. Moreover, the device can also be flexibly configured according to the needs of different machine tools, improving the adaptability and scalability of the device. In addition, by arranging the detection part of the displacement detection device 1 in parallel with the detection surface 101 of the tool handle 100, the vertical distance between the two can be accurately measured, thereby monitoring the thermal displacement of the spindle in real time. This design reduces the error caused by improper installation angle and ensures the reliability of measurement. By directly connecting the control device to the displacement detection device 1, the complexity of signal transmission is reduced, and the possibility of the signal being subject to electromagnetic interference or noise during transmission is reduced. The control device obtains the data of the displacement detection device in real time, so that the system can respond quickly and make adjustments according to the actual thermal displacement situation, further enhancing the anti-interference ability. In addition, the control device can adapt to changes under various operating conditions and improve the flexibility and accuracy of the system operation. The thermal compensation device of the machine tool electric spindle of the present invention can effectively solve the technical problems of the thermal compensation device of the machine tool electric spindle in the prior art, which has a complex structure and poor anti-interference ability.

[0031] Optionally, the displacement detection device 1 is a displacement sensor, preferably an eddy current displacement sensor.

[0032] Optionally, the detection surface 101 of the tool handle 100 is a flat end surface of the tool handle 100 , and the edge of the detection part of the displacement detection device 1 is located at the inner side of the edge of the detection surface 101 of the tool handle 100 , so that the edge of the detection part of the displacement detection device 1 cannot protrude from the edge of the detection surface 101 of the tool handle 100 .

[0033] Furthermore, the detection surface of the tool handle 100 is located above the detection portion of the displacement detection device 1 .

[0034] Optionally, the control device is a programmable logic controller (PLC).

[0035] Optionally, the spindle can be understood as the axis of the electric spindle of the machine tool, so that the tool handle 100 can be driven to rotate by the rotation of the spindle.

[0036] Specifically, Figures 1 to 3 As shown, the thermal compensation device also includes: a fixing device 2, which is movably mounted on the handle 100 in the vertical direction; the mounting surface 20 of the fixing device 2 is arranged opposite to the detection surface 101 of the handle 100; the detection part of the displacement detection device 1 is mounted on the mounting surface 20 of the fixing device 2, so that the initial distance between the detection part of the displacement detection device 1 and the detection surface 101 of the handle 100 can be adjusted by moving the fixing device 2 in the vertical direction. With such a structural arrangement, by setting the fixing device 2, the detection part of the displacement detection device 1 can be mounted on the handle 100 through the fixing device 2. The fixing device 2 can be movable relative to the handle 100 in the vertical direction, so that the initial distance between the detection part of the displacement detection device 1 and the detection surface 101 of the handle 100 can be adjusted. This design reduces the time and complexity required for initial calibration and improves work efficiency. At the same time, the mobility of the fixing device 2 enables the device to adapt to tools of different lengths and types, and has higher flexibility and versatility. In addition, by precisely adjusting the initial distance, measurement errors caused by external factors (such as vibration or temperature changes) can be reduced, providing a more stable working environment.

[0037] Furthermore, the mounting surface 20 of the fixing device 2 is in a horizontal plane state, and the mounting surface 20 of the fixing device 2 and the detection surface 101 of the tool handle 100 are parallel to each other.

[0038] Optionally, when adjusting the initial distance between the detection portion of the displacement detection device 1 and the detection surface 101 of the tool handle 100, the fixing device 2 reciprocates in the vertical direction. After the adjustment is completed, the fixing device 2 will remain stationary.

[0039] Specifically, Figure 2 and Figure 3As shown, a through hole 21 and at least one mounting groove 22 are provided on the mounting surface 20 of the fixing device 2. The through hole 21 extends in the vertical direction. The axis of the through hole 21 is arranged parallel to the axis of the knife handle 100. The fixing device 2 is sleeved on the knife handle 100 through the through hole 21. At least one mounting groove 22 is arranged at intervals from the through hole 21, and at least one mounting groove 22 is arranged opposite to the detection surface 101 of the knife handle 100. The displacement detection device 1 includes at least one coil 11, and at least one coil 11 forms a detection part of the displacement detection device 1. The coil 11 is arranged one-to-one with the mounting groove 22, and the coil 11 is installed in the corresponding mounting groove 22. The coil 11 is arranged opposite to and parallel to the detection surface 101 of the knife handle 100. With such a structural arrangement, the fixing device 2 is conveniently sleeved on the knife handle 100 by setting the through hole 21, and the coil 11 is conveniently installed in the corresponding mounting groove 22 by setting the mounting groove 22 and the mounting groove 22 corresponds to the coil 11, thereby ensuring the accuracy of the position of the coil 11. In addition, the coil 11 is parallel to and opposite to the detection surface 101 of the tool handle 100 , which can ensure the accuracy of detection and prevent detection errors.

[0040] Optionally, there are a plurality of mounting grooves 22 , which are evenly spaced around the circumferential direction of the through hole 21 , and there are a plurality of coils 11 , which are disposed in one-to-one correspondence with the plurality of mounting grooves 22 .

[0041] Furthermore, the fixture 2 is a symmetrical structure, having a central symmetry line, which is respectively parallel to the axis of the spindle and the axis of the tool handle 100. The axis of the through hole 21 coincides with the central symmetry line of the fixture 2.

[0042] Optionally, the axis of the through hole 21 coincides with the axis of the handle 100, and the diameter of the through hole 21 is greater than the diameter of the handle body 102 of the handle 100. In this way, when the handle 100 rotates with the spindle, the through hole 21 can avoid the handle 100, thereby effectively preventing interference and friction.

[0043] Specifically, the thermal compensation device also includes: a potting material, which is poured into the mounting groove 22 to fix the coil 11 in the corresponding mounting groove 22 through the potting material. With such a structural setting, by pouring the potting material into the mounting groove 22, the coil 11 can be effectively fixed, ensuring its position in the mounting groove 22 is stable, and reducing displacement caused by vibration or mechanical movement. The application of the potting material improves the impact resistance and wear resistance of the coil 11 and extends the service life of the equipment. And through potting, the contact between the coil 11 and the external environment is reduced, thereby reducing the impact of moisture, dust and other pollutants on the detection accuracy.

[0044] Optionally, the potting material is epoxy resin.

[0045] Specifically, Figure 2 , Figure 3 and Figure 6 As shown, the handle 100 includes a handle body 102 and a positioning ring 103, the positioning ring 103 is sleeved on the handle body 102, the positioning ring 103 is coaxially arranged with the handle body 102 and the spindle, and the bottom end surface of the positioning ring 103 forms the detection surface 101 of the handle 100; the cross section of the mounting groove 22 is circular, and the distance from the axis of the through hole 21 to the edge of the mounting groove 22 is less than the outer diameter of the positioning ring 103; the wall thickness of the positioning ring 103 (attached Figure 6 D1 is the wall thickness of the positioning ring 103) which is larger than the outer diameter of the coil 11. With such a structural arrangement, the positioning ring 103 is coaxially arranged with the tool handle body 102 and the spindle, ensuring the precise alignment of the tool and the spindle. This coaxial design effectively reduces vibration and deviation during machining and improves machining accuracy. The bottom end surface of the positioning ring 103 forms the detection surface 101 of the tool handle 100, providing it with a stable and reliable reference surface, thereby ensuring the consistency and reliability of the detection surface 101 and avoiding measurement errors caused by surface unevenness. In addition, the distance from the axis of the through hole 21 to the edge of the mounting groove 22 is designed to be smaller than the outer diameter of the positioning ring 103, ensuring that each mounting groove 22 is located at the inner side of the edge of the detection surface 101, preventing the edge of the coil 11 from protruding from the edge of the detection surface 101. Such a design can reduce external interference and noise and improve the stability of signal acquisition. Meanwhile, the wall thickness of the positioning ring 103 is greater than the outer diameter of the coil 11, thereby further ensuring that the coil 11 is always located inside the edge of the detection surface 101, thereby eliminating the adverse effects of the edge effect on the output signals of each coil 11. The detection accuracy of the displacement detection device 1 is improved.

[0046] Optionally, the wall thickness of the positioning ring 103 should be greater than 3 times the outer diameter of the coil 11 .

[0047] Specifically, Figure 2 , Figure 7 and Figure 8As shown, at least one outlet hole 23 is provided on the side wall of the fixing device 2, and the outlet hole 23 is respectively arranged in one-to-one correspondence with the mounting groove 22 and the coil 11, and the outlet hole 23 is connected with the corresponding mounting groove 22; the displacement detection device 1 also includes: at least one signal line and a processor 12, the signal line is arranged in one-to-one correspondence with the coil 11, one end of the signal line is connected with the corresponding coil 11, and the other end of the signal line passes through the mounting groove 22 and the outlet hole 23 in sequence and is located outside the fixing device 2; the processor 12 is connected with one end of the signal line away from the corresponding coil 11, and the processor 12 receives the data detected by the corresponding coil 11 through the signal line; the processor 12 is used to process the data detected by the coil 11. With such a structural setting, the outlet hole 23 is located on the side wall of the fixing device 2, so that the signal line can pass through the mounting groove 22 and the outlet hole 23 in an orderly manner, avoiding the problem of disorderly cables, thereby improving the neatness of the device and facilitating management and maintenance. The processor 12 receives the data detected by the corresponding coil 11 through the signal line, and then the processor 12 can quickly process the received data and adjust the position of the main shaft as needed to achieve error compensation, thereby improving the response speed of the device.

[0048] Furthermore, one end of each signal line located outside the fixing device 2 is connected to the processor 12 via an aviation socket.

[0049] Furthermore, if Figure 8 and Fig. 9 As shown, the processor 12 includes a placement chamber 121 and a circuit board, and the circuit board is located in the placement chamber 121 to protect the circuit board through the placement chamber 121. The circuit board is connected to each coil 11 through each signal line, and the circuit board is used to receive the signal detected by each coil 11, and perform signal amplification and other processing on the signal detected by each coil 11, and finally obtain the detected distance between the detection part and the detection surface, thereby detecting the thermal displacement of the spindle, and transmitting the detected result to the control device.

[0050] Furthermore, the processor 12 is disposed on a side wall of the shaft assembly 200 .

[0051] Furthermore, an adjustment groove 24 is provided on the mounting surface 20 of the fixing device 2. The adjustment groove 24 is arranged in one-to-one correspondence with the mounting groove 22. The adjustment groove 24 is respectively connected with the corresponding mounting groove 22 and the wire outlet hole 23, and the adjustment groove 24 is located on the side of the mounting groove 22 away from the through hole 21. After one end of the signal line is connected to the corresponding coil 11, the other end of the signal line passes through the mounting groove 22, the adjustment groove 24 and the wire outlet hole in sequence to connect with the processor 12. By setting the adjustment groove 24, the position of the corresponding signal line and the output and input ends of the coil 11 can be adjusted in the adjustment groove 24, and the corresponding signal line and the output and input ends of the coil 11 are fixed by the adjustment groove 24. In addition, the installation and later maintenance of the signal line and the coil 11 are also facilitated.

[0052] Specifically, Figure 1 As shown, the electric spindle 300 of the machine tool includes a shaft assembly 200 and a spindle, wherein the shaft assembly 200 is provided with a placement cavity, and at least part of the spindle is rotatably arranged in the placement cavity; the thermal compensation device also includes: a support device 3, which is mounted on the shaft assembly 200; the support device 3 is connected to the fixing device 2, and the fixing device 2 is movably arranged relative to the support device 3. With such a structural arrangement, the support device 3 is mounted on the shaft assembly 200, providing a stable mechanical support for the fixing device 2. This stable support reduces the error caused by vibration during the processing and improves the stability and reliability of the system. At the same time, the fixing device 2 is movably arranged relative to the support device 3, so that the position of the fixing device 2 can be flexibly adjusted according to actual needs, thereby ensuring that its position relative to the tool handle 100 is accurate, and then determining the position of the detection part of the displacement detection device 1 relative to the detection surface 101. This design also avoids the interference of the fixing device 2 with the tool handle, ensuring the smooth progress of the processing process.

[0053] Optionally, the fixture 2 and the support 3 are both made of materials with low thermal expansion and good rigidity, such as steel, ceramic materials, etc. By using such materials, the thermal displacement of the fixture 2 and the support 3 can be controlled within a minimum range during the high-speed operation of the spindle.

[0054] Specifically, Figure 1 , Figure 4 and Figure 5As shown, the support device 3 includes: a first support frame 31 and a second support frame 32, which are installed on the shaft assembly 200, and are respectively located on both sides of the fixing device 2, and the first support frame 31 and the second support frame 32 are arranged opposite to each other; the thermal compensation device also includes: a first connecting rod 4 and a second connecting rod 5, which are coaxially arranged, and the first connecting rod 4 and the second connecting rod 5 are respectively installed on the first supporting frame 31 and the second supporting frame 32 in an adjustable manner along the vertical direction, and the end of the first connecting rod 4 away from the first supporting frame 31 and the end of the second connecting rod 5 away from the second supporting frame 32 are both detachably connected to the fixing device 2; so that when the position of the first connecting rod 4 relative to the first supporting frame 31 and the position of the second connecting rod 5 relative to the second supporting frame 32 are adjusted, the fixing device 2 is driven to move in the vertical direction. With such a structural arrangement, the first supporting frame 31 and the second supporting frame 32 are respectively installed on the shaft assembly 200, providing a stable mechanical support for the entire thermal compensation device. The stability and reliability of the system are improved. The first connecting rod 4 and the second connecting rod 5 are coaxially arranged to ensure that the movement of the fixing device 2 in the vertical direction is smooth and symmetrical. This coaxial design ensures that the fixing device 2 will not deflect during the movement, and maintains high-precision displacement detection. At the same time, the first connecting rod 4 and the second connecting rod 5 are adjustably mounted on the first support frame 31 and the second support frame 32 in the vertical direction, so that the height of the fixing device 2 can be flexibly adjusted. Through this design, it can be ensured that the distance between the detection part of the displacement detection device 1 and the detection surface 101 is adjusted to a preset value. In addition, the first connecting rod 4 and the second connecting rod 5 are both detachably connected to the fixing device 2, which can facilitate the replacement and installation of the fixing device 2 according to actual needs, thereby reducing the difficulty and cost of maintenance.

[0055] Furthermore, two connecting holes 25 are provided on the fixing device 2, and the two connecting holes 25 are arranged at intervals on the side wall of the fixing device 2, and the two connecting holes 25 are arranged opposite to each other, and both connecting holes 25 are provided with internal threads, and one end of the first connecting rod 4 close to the fixing device 2 and one end of the second connecting rod 5 close to the fixing device 2 are provided with external threads adapted to the internal threads, so that the first connecting rod 4 and the second connecting rod 5 are detachably connected to the fixing device 2 through threaded connection.

[0056] Specifically, Figure 1 , Figure 4 and Figure 5As shown, the first support frame 31 is provided with a plurality of first mounting holes 310, and each first mounting hole 310 is arranged at intervals in the vertical direction; the second support frame 32 is provided with a plurality of second mounting holes 320, and each second mounting hole 320 is arranged at intervals in the vertical direction; each first mounting hole 310 is arranged in one-to-one correspondence with each second mounting hole 320; wherein, the end of the first connecting rod 4 away from the fixing device 2 is penetrated through any first mounting hole 310 in each first mounting hole 310; the end of the second connecting rod 5 away from the fixing device 2 is penetrated through the corresponding second mounting hole 320, so that the fixing device 2 is connected to the first support frame 31 and the second support frame 32 respectively. With such a structural setting, the plurality of first mounting holes 310 and the second mounting holes 320 are arranged at intervals in the vertical direction, providing a plurality of height selection points. The user can select the appropriate first mounting hole 310 and the second mounting hole 320 for connection according to actual needs to achieve precise height adjustment. Each first mounting hole 310 corresponds to each second mounting hole 320 one by one, ensuring that the mounting surface and the detection surface of the fixture 2 are arranged horizontally, and ensuring that the fixture 2 does not deflect during movement, maintaining high-precision displacement detection. Since there are multiple mounting holes to choose from, the height of the fixture 2 can be optimized by simply selecting the appropriate mounting hole during initial calibration. This flexibility makes the calibration process simpler and faster, reducing the time and complexity of initial setup. When the fixture 2 or its components need to be replaced or repaired, the fixture 2 can be easily disassembled and reinstalled by disassembling the first connecting rod 4 and the second connecting rod 5, reducing the difficulty and cost of maintenance.

[0057] Specifically, Figure 1 , Figure 4 and Figure 5As shown, the first support frame 31 has a first mounting portion 311 and a first connecting portion 312, the first mounting portion 311 is connected to the first connecting portion 312, and the first connecting portion 312 is located below the first mounting portion 311; the first mounting portion 311 is used to be fixedly connected to the shaft assembly 200; the first connecting portion 312 extends in the vertical direction, and a plurality of first mounting holes 310 are provided on the first connecting portion 312, and each first mounting hole 310 is spaced apart along the extending direction of the first connecting portion 312; the second support frame 32 has The second mounting portion 321 and the second connecting portion 322 are connected, and the second connecting portion 322 is located below the second mounting portion 321; the second mounting portion 321 is used to be fixedly connected to the shaft assembly 200; the second connecting portion 322 extends in the vertical direction, and a plurality of second mounting holes 320 are provided on the second connecting portion 322, and each second mounting hole 320 is spaced apart along the extending direction of the second connecting portion 322; the first connecting portion 312 is arranged opposite to the second connecting portion 322. With such a structural arrangement, the first mounting portion 311 and the second mounting portion 321 are respectively fixedly connected to the shaft assembly 200, ensuring the firmness of the entire supporting device and reducing the displacement caused by vibration or external force. The first connecting portion 312 and the second connecting portion 322 are provided with a plurality of first mounting holes 310 and second mounting holes 320 spaced apart along the vertical direction, providing a plurality of height selection points for the fixing device 2, and realizing precise height adjustment.

[0058] Furthermore, the shaft assembly 200 includes a first shaft 201 and a second shaft 202 , wherein the first shaft 201 is connected to the second shaft 202 via a flange 203 to enclose at least a portion of a placement cavity for placing the spindle. The first support frame 31 and the second support frame 32 are mounted on the flange 203 .

[0059] Optionally, the placement cavity is a symmetrical structure, the placement cavity has a central symmetry line, and the central symmetry line of the placement cavity is coaxially arranged with the axis of the main shaft.

[0060] Furthermore, if Figure 4 As shown, the first mounting portion 311 extends in a preset direction, the extension direction of the first mounting portion 311 is perpendicular to the extension direction of the first connecting portion 312, and the first mounting portion 311 is provided with a first opening groove 313, which extends in the extension direction of the first mounting portion 311. The thermal compensation device also includes: a first fastener, the limiting end of the first fastener is located below the first mounting portion 311, and the connecting portion of the first fastener is inserted into the first opening groove 313. When the first support frame 31 is mounted on the flange 203 by the first fastener placed in the first opening groove 313, the limiting end of the first fastener abuts against the bottom end surface of the first mounting portion 311.

[0061] Furthermore, if Figure 5 As shown, the second mounting portion 321 extends in a preset direction, the extension direction of the second mounting portion 321 is perpendicular to the extension direction of the second connecting portion 322, and a second opening groove 323 is provided on the second mounting portion 321, and the second opening groove 323 extends in the extension direction of the second mounting portion 321. The thermal compensation device also includes: a second fastener, the limiting end of the second fastener is located below the second mounting portion 321, and the connecting portion of the second fastener is inserted into the second opening groove 323. When the second support frame 32 is mounted on the flange 203 by the second fastener placed in the second opening groove 323, the limiting end of the second fastener abuts against the bottom end surface of the second mounting portion 321.

[0062] Optionally, the process of adjusting the distance between the detection part of the displacement detection device 1 and the detection surface 101 is: First, each coil 11 is installed on the fixing device 2, and each coil 11 is connected to the processor. At the same time, the first support frame 31 and the second support frame 32 are installed on the flange 203, and the first support frame 31 and the second support frame 32 are respectively located on both sides of the handle 100, and the first connecting portion 312 of the first support frame 31 and the second connecting portion 322 of the second support frame 32 are arranged opposite to each other.

[0063] Secondly, the fixing device 2 is sleeved on the handle body 102 of the handle 100 through the through hole 21, and then the displacement detection device 1 is turned on, and the fixing device 2 is moved in the vertical direction. The position of the detection part of the displacement detection device 1 relative to the detection surface 101 is adjusted according to the detection data of the displacement detection device 1. When the output voltage corresponding to the distance between the detection part of the displacement detection device 1 and the detection surface 101 reaches the set value, the first connecting rod 4 and the second connecting rod 5 are respectively connected to the fixing device 2 through the corresponding first mounting hole 310 and the second mounting hole 320 to fix the fixing device 2 at this position, which is the initial installation position. Thus, the adjustment work is completed. And the output voltage corresponding to the distance is used as the reference voltage to facilitate the subsequent detection of the thermal displacement of the spindle.

[0064] The present invention provides a CNC machine tool, characterized in that it comprises: the thermal compensation device of the above embodiment. With such a structural arrangement, the CNC machine tool has the same beneficial effects as those achieved by the thermal compensation device of the above embodiment, which will not be described in detail here.

[0065] The present invention provides a thermal compensation method, which is applied to the thermal compensation device mentioned above; Fig. 9 As shown, the thermal compensation method includes: S11. Before the machine tool is operated, determine the initial output voltage of the displacement detection device 1 .

[0066] S12: When the machine tool is running, obtain the current output voltage of the displacement detection device 1 .

[0067] S13, according to the current output voltage of the displacement detection device 1 and the initial output voltage of the displacement detection device 1 , and adaptively adjust the position of the main axis in the vertical direction to achieve error compensation. Wherein, n is the number of detections of the displacement detection device 1, n≥1.

[0068] By adopting such a control method, before the machine tool is operated, the initial output voltage of the displacement detection device 1 is determined. , which can provide a reference for subsequent error compensation. When the machine tool is running, the current output voltage of the displacement detection device 1 is obtained in real time. , can monitor the thermal expansion of the spindle in real time. According to the current output voltage of the displacement detection device 1 and the initial output voltage of the displacement detection device 1 , adaptively adjust the position of the spindle in the vertical direction, realize dynamic error compensation, ensure that the tool remains in the correct position, thereby significantly reducing the processing error caused by temperature changes, improving the surface processing accuracy of the workpiece, and shortening the warm-up time of the machine tool, so that the machine tool can enter the processing state faster, saving time and cost. In addition, by adjusting the position of the spindle in real time, the vibration and instability factors caused by thermal expansion are reduced, the stability of the processing process is ensured, and the processing error is further reduced. By adjusting the current output voltage of the displacement detection device 1 according to the current output voltage of the displacement detection device 1 and the initial output voltage of the displacement detection device 1 , adaptively adjust the position of the spindle in the vertical direction, and achieve accurate error compensation. This method not only enhances the stability and reliability of the system, but also simplifies the operation process and improves the flexibility and efficiency of the system.

[0069] like Fig.10 As shown, the measuring range of the eddy current displacement sensor is 500 microns, and the output voltage of the corresponding sensor is 0-10V, so that the distance of the detection part of the displacement detection device 1 relative to the detection surface 101 is adjusted by moving the fixing device 2 in the vertical direction, so that the distance of the detection part of the displacement detection device 1 relative to the detection surface 101 is less than the measuring range of the eddy current displacement sensor, and the output voltage corresponding to the distance of the detection part of the displacement detection device 1 relative to the detection surface 101 reaches a preset voltage value. When the output voltage corresponding to the distance of the detection part of the displacement detection device 1 relative to the detection surface 101 reaches the preset voltage value, the fixing device 2 is fixed at this position, and the output voltage is used as the initial output voltage of the displacement detection device 1 For example, when the measuring range of the eddy current displacement sensor is 500 microns, the distance between the detection part of the displacement detection device 1 and the detection surface 101 is adjusted to 250 microns, so as to determine the initial output voltage of the displacement detection device 1. is 5V.

[0070] To further ensure the accuracy of thermal compensation, the current output voltage of the displacement detection device 1 is determined. In the process, a multi-coil collaborative detection and data processing method was adopted. The specific steps are as follows: Signal acquisition: When there are multiple coils 11 , the signals detected by each coil 11 are sent to the processor 12 .

[0071] Signal processing: The processor 12 processes the signal detected by each coil 11 and converts it into a corresponding voltage signal.

[0072] Data fusion: The processor 12 calculates the average value of the voltage signals of all coils 11 as the current output voltage .

[0073] Through this method, not only the accuracy and reliability of the detection data are improved, but also the anti-interference ability of the system is enhanced, ensuring the high precision and stability of the spindle thermal compensation.

[0074] Specifically, according to the current output voltage of the displacement detection device 1 and the initial output voltage of the displacement detection device 1 , adaptively adjusting the position of the spindle in the vertical direction to achieve error compensation method, including: calculating the current output voltage With the initial output voltage The first voltage difference ; To set the absolute value of the first voltage difference The sensitivity of the displacement detection device 1 The first voltage difference is compared and , determine the error compensation direction of the main axis in the vertical direction; according to the absolute value of the first voltage difference The sensitivity of the displacement detection device 1 The comparison result and the determined error compensation direction are used to adjust the position of the spindle in the vertical direction; wherein the sensitivity of the displacement detection device 1 is The unit is By using this control method, the current output voltage With the initial output voltage The first voltage difference The sensitivity of the displacement detection device 1 By comparison, micron-level thermal compensation can be achieved, thus completing the spindle thermal displacement compensation operation efficiently and accurately, thereby improving the workpiece surface processing accuracy and shortening the machine tool warm-up time. In addition, voltage data is continuously collected during the processing to ensure the timeliness and accuracy of compensation.

[0075] Among them, the sensitivity of the displacement detection device 1 is This is the sensitivity of the eddy current displacement sensor. The sensitivity refers to the response capability of the device (i.e., eddy current displacement sensor) to a unit displacement change. Specifically, it is the change in the output signal (such as voltage) caused by a unit displacement change. Its unit is usually "voltage / displacement", for example Sensitivity reflects the accuracy of the displacement detection device in sensing and responding to tiny displacement changes.

[0076] Specifically, according to the absolute value of the first voltage difference The sensitivity of the displacement detection device 1 The method for adjusting the position of the spindle in the vertical direction based on the comparison result of the error compensation direction and the determined error compensation direction includes: when 1, and when the error compensation direction of the spindle is determined to be vertically upward, control the spindle to move upward 1 ;when 1, and when the error compensation direction of the spindle is determined to be vertically downward, control the spindle to move downward 1 By adopting such a control method, the absolute value of the first voltage difference is accurately determined. The sensitivity of the displacement detection device The comparison results of the number of detections are combined with the determined error compensation direction to adjust the vertical position of the spindle, which can accurately compensate for the deviation of the spindle in the vertical direction. The spindle is placed in the ideal position as much as possible during the processing, thereby improving the dimensional accuracy and shape accuracy of the processed workpiece and ensuring the processing quality.

[0077] Wherein, n is the number of detections performed by the displacement detection device 1 , and n≥1.

[0078] Optionally, the thermal compensation method in this embodiment uses an arithmetic progression for compensation.

[0079] Specifically, according to the first voltage difference , a method for determining an error compensation direction of a main axis in a vertical direction, comprising: determining an error compensation direction of a main axis in a vertical direction according to a first voltage difference , judge the thermal displacement direction of the spindle; determine the vertical error compensation direction of the spindle according to the thermal displacement direction of the spindle; when the thermal displacement direction of the spindle is vertically upward, determine the vertical error compensation direction of the spindle to be vertically downward; when the thermal displacement direction of the spindle is vertically downward, determine the vertical error compensation direction of the spindle to be vertically upward. Using such a control method, according to the first voltage difference , it is possible to determine the error compensation direction of the spindle and thus enable accurate displacement compensation.

[0080] Specifically, according to the first voltage difference , the method for determining the thermal displacement direction of the spindle includes: When , the thermal displacement direction of the main axis is vertically upward; when When the thermal displacement direction of the spindle is vertically downward, the control method can accurately determine the thermal displacement direction to ensure the correct direction of error compensation, avoid error accumulation caused by reverse compensation, and further improve machining accuracy.

[0081] Optionally, from Fig.10 It can be seen from the displacement amount and the output voltage of the displacement detection device 1 shown in the figure that the larger the displacement amount, the larger the corresponding output voltage of the displacement detection device 1. The detection part of the displacement detection device 1 is located below the detection surface 101. Therefore, when the distance between the detection part of the displacement detection device 1 and the detection surface 101 increases, the current output voltage of the displacement detection device 1 increases. Will become bigger, at this time It should be a positive value, and it can be determined that the thermal displacement direction of the spindle is vertically upward, so it is necessary to control the spindle to move downward to achieve error compensation. Similarly, when the distance between the detection part of the displacement detection device 1 and the detection surface 101 becomes smaller, the current output voltage of the displacement detection device 1 will become smaller, at this time It should be a negative value, and it can be determined that the thermal displacement direction of the spindle is vertically downward, so the spindle needs to be controlled to move upward to achieve error compensation.

[0082] Specifically, the thermal compensation method further includes: determining whether the spindle speed is switched; when the spindle speed is switched, calculating the next output voltage of the displacement detection device 1 The current output voltage of the displacement detection device 1 The second voltage difference According to the second voltage difference , to determine whether the next output voltage of the displacement detection device 1 As the new initial output voltage of the displacement detection device 1 ; When the next output voltage of the displacement detection device 1 is As the new initial output voltage of the displacement detection device 1 When the new initial output voltage As the reference voltage, restart the thermal displacement detection of the spindle, and perform error compensation on the spindle according to the detection results. With this control method, when the spindle speed switches, the system can update the initial output voltage in time to ensure that the subsequent thermal displacement detection is based on the latest reference voltage, thereby avoiding the accumulation of errors caused by speed changes. By real-time monitoring of the spindle speed and dynamically adjusting the reference voltage, the system can not only better adapt to speed changes, but also maintain high-precision processing capabilities. This thermal compensation method realizes thermal displacement compensation in the full speed range, is suitable for various complex working conditions, and significantly improves processing accuracy and system reliability.

[0083] Optionally, when the spindle switches speed, the output voltage of the displacement detection device may undergo a step change. For example, when the spindle switches from 6000 rpm to 12000 rpm, the current output voltage obtained is 5.14V, and the next output voltage drops to 5.10V. This indicates that the spindle has undergone significant vertical downward thermal displacement. At this time, if error compensation is to be performed, the system needs to wait for the output voltage to rise back to 5.14V before compensation can be performed. This results in a significant time delay in error compensation, and the thermal displacement cannot be corrected in real time, which may affect the machining accuracy. And delayed compensation may cause brief interruptions in the machining process, thereby affecting the overall production efficiency and continuity. However, by using the above method to immediately update the reference voltage when a significant step change is detected, it can ensure that subsequent thermal displacement detection is based on the latest reference point, reducing compensation delays.

[0084] Specifically, according to the second voltage difference , to determine whether the next output voltage of the displacement detection device 1 As the new initial output voltage of the displacement detection device 1 The method comprises: setting a second voltage difference With preset threshold to compare; when When the displacement detection device 1 outputs the next voltage As the new initial output voltage of the displacement detection device 1 By adopting such a control method, the second voltage difference With preset threshold By making a comparison, the initial output voltage can be adjusted in time, so that subsequent measurements can be carried out based on a more accurate reference. This method effectively reduces the measurement error caused by reference deviation and significantly improves the accuracy and reliability of the measurement. By dynamically adjusting the reference voltage, the measurement error caused by the accumulation of reference deviation is avoided, and the measurement accuracy of the entire system is improved.

[0085] Optionally, the specific steps of the thermal compensation method are: The sensitivity of the displacement detection device 1 is 14 mv / μm.

[0086] Step 1: Before the machine tool is operated, the distance between the detection part of the displacement detection device 1 and the detection surface 101 is adjusted to move the detection part of the displacement detection device 1 to the initial installation position, and the displacement detection device 1 collects the output voltage corresponding to the initial installation position. The output voltage is determined as the initial output voltage of the displacement detection device 1. .

[0087] Step 2: After the machine tool is running and the spindle is in operation, the displacement detection device 1 continuously collects the output voltage at a sampling rate of 2000 voltage values ​​per second. At the same time, the collected current output voltage With the initial output voltage Compare to detect whether the spindle has thermal displacement, and according to the current output voltage With the initial output voltage The first voltage difference , determine the error compensation direction of the spindle in the vertical direction.

[0088] The specific comparison process is: Step 21: When , the thermal displacement direction of the spindle is vertically upward, then the error compensation direction of the spindle is determined to be vertically downward; when When the thermal displacement direction of the spindle is vertically downward, the error compensation direction of the spindle is determined to be vertically upward. Is it greater than or equal to 1?

[0089] Step 22: If When it is greater than or equal to 1, the spindle is controlled to move upward or downward according to the determined spindle error compensation direction. .like When it is greater than or equal to 1, the spindle is controlled to move upward or downward according to the determined spindle error compensation direction. By analogy, if When it is greater than or equal to 1, the spindle is controlled to move upward or downward by 1 .

[0090] Among them, when the spindle is working normally, when the direction of thermal displacement generated by the spindle is vertically downward, the subsequent thermal displacement directions of the spindle are all vertically downward. Conversely, the same. At the same time, when the error compensation direction of the determined spindle is vertically upward, the circuit board of the displacement detection device 1 will send a high-level pulse signal to the PLC, and the PLC controls the spindle to move upward. When the error compensation direction of the determined spindle is vertically downward, the circuit board of the displacement detection device 1 will send a low-level pulse signal to the PLC, and the PLC controls the spindle to move downward.

[0091] Step 23: During the error compensation process, the counting module of the thermal compensation device accumulates the detection times of the displacement detection device 1 .

[0092] Step 3: During the rotation of the spindle, the spindle speed is detected in real time. When the spindle speed is switched, the output voltage of the displacement detection device 1 changes stepwise. At this time, the next output voltage of the displacement detection device 1 is determined. The current output voltage of the displacement detection device 1 The second voltage difference Is it greater than or equal to the preset threshold? If it is greater than, the next output voltage of the displacement detection device 1 is As the new initial output voltage of the displacement detection device 1 At this time, the detection times n of the displacement detection device 1 in the counting module is reset to 1. The subsequent times of the output voltage of the displacement detection device 1 are counted from 1, thereby starting a new round of arithmetic progression compensation.

[0093] Step 4: When the machine tool completes processing, the displacement detection device 1 cuts off the power supply and is in a closed state.

[0094] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable when appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0095] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0096] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0097] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0098] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A thermal compensation device for a machine tool electric spindle, characterized in that: include: A displacement detection device (1), wherein a detection portion of the displacement detection device (1) is arranged on a tool handle (100) connected to the main shaft, the detection portion of the displacement detection device (1) and a detection surface (101) of the tool handle (100) are arranged at intervals in the vertical direction, and the detection portion of the displacement detection device (1) and the detection surface (101) of the tool handle (100) are arranged opposite to and in parallel with each other; the displacement detection device (1) detects the thermal displacement of the main shaft in the vertical direction by detecting a change in the distance between the detection portion of the displacement detection device (1) and the detection surface (101) of the tool handle (100); A control device is connected to the displacement detection device (1), and is used to obtain data detected by the displacement detection device (1), and to adaptively adjust the position of the main shaft in the vertical direction according to the data detected by the displacement detection device (1) to achieve error compensation.

2. The thermal compensation device according to claim 1, characterized in that: The thermal compensation device further comprises: a fixing device (2), the fixing device (2) being movably mounted on the tool handle (100) along the vertical direction; a mounting surface (20) of the fixing device (2) being arranged opposite to a detection surface (101) of the tool handle (100); and a detection portion of the displacement detection device (1) being mounted on the mounting surface (20) of the fixing device (2), so that the initial distance between the detection portion of the displacement detection device (1) and the detection surface (101) of the tool handle (100) can be adjusted by moving the fixing device (2) along the vertical direction.

3. The thermal compensation device according to claim 2, characterized in that: A through hole (21) and at least one mounting groove (22) are provided on the mounting surface (20) of the fixing device (2); the through hole (21) extends along the vertical direction; the axis of the through hole (21) is arranged parallel to the axis of the knife handle (100); the fixing device (2) is sleeved on the knife handle (100) through the through hole (21); at least one mounting groove (22) is arranged at intervals from the through hole (21), and at least one mounting groove (22) is arranged opposite to the detection surface (101) of the knife handle (100); The displacement detection device (1) comprises at least one coil (11), wherein the at least one coil (11) forms a detection portion of the displacement detection device (1); the coil (11) and the mounting groove (22) are arranged in a one-to-one correspondence, and the coil (11) is installed in the corresponding mounting groove (22); the coil (11) and the detection surface (101) of the tool handle (100) are arranged opposite to and in parallel.

4. The thermal compensation device according to claim 3, characterized in that: The thermal compensation device further comprises: a potting material, the potting material being poured into the mounting groove (22) so as to fix the coil (11) in the corresponding mounting groove (22) through the potting material; and / or, The tool handle (100) comprises a tool handle body (102) and a positioning ring (103), wherein the positioning ring (103) is sleeved on the tool handle body (102), and the positioning ring (103) is coaxially arranged with the tool handle body (102) and the main shaft respectively, and the bottom end surface of the positioning ring (103) forms a detection surface (101) of the tool handle (100); the cross section of the mounting groove (22) is circular, and the distance from the axis of the through hole (21) to the edge of the mounting groove (22) is smaller than the outer diameter of the positioning ring (103); the wall thickness of the positioning ring (103) is larger than the outer diameter of the coil (11).

5. The thermal compensation device according to claim 3, characterized in that: At least one wire outlet hole (23) is provided on the side wall of the fixing device (2), and the wire outlet holes (23) are respectively arranged in one-to-one correspondence with the mounting slot (22) and the coil (11), and the wire outlet holes (23) are connected to the corresponding mounting slot (22); the displacement detection device (1) also includes: at least one signal line, the signal line being arranged in one-to-one correspondence with the coil (11), one end of the signal line being connected to the corresponding coil (11), and the other end of the signal line passing through the mounting groove (22) and the wire outlet hole (23) in sequence and being located outside the fixing device (2); A processor (12), the processor (12) being connected to an end of the signal line away from the corresponding coil (11), the processor (12) receiving data detected by the corresponding coil (11) through the signal line; the processor (12) being used to process the data detected by the coil (11).

6. The thermal compensation device according to claim 2, characterized in that: The electric spindle (300) of the machine tool comprises: a shaft assembly (200) and the spindle, wherein a placement cavity is provided in the shaft assembly (200), and at least part of the spindle is rotatably arranged in the placement cavity; the thermal compensation device further comprises: a support device (3), wherein the support device (3) is mounted on the shaft assembly (200); the support device (3) is connected to the fixing device (2), and the fixing device (2) is movably arranged relative to the support device (3).

7. The thermal compensation device according to claim 6, characterized in that: The support device (3) comprises: a first support frame (31) and a second support frame (32), the first support frame (31) and the second support frame (32) being mounted on the shaft assembly (200), the first support frame (31) and the second support frame (32) being located on two sides of the fixing device (2), respectively, and the first support frame (31) and the second support frame (32) being arranged opposite to each other; The thermal compensation device further comprises: a first connecting rod (4) and a second connecting rod (5), wherein the first connecting rod (4) and the second connecting rod (5) are coaxially arranged, and the first connecting rod (4) and the second connecting rod (5) are respectively mounted on the first support frame (31) and the second support frame (32) in an adjustable manner in the vertical direction, and an end of the first connecting rod (4) away from the first support frame (31) and an end of the second connecting rod (5) away from the second support frame (32) are both detachably connected to the fixing device (2); so that when the position of the first connecting rod (4) relative to the first support frame (31) and the position of the second connecting rod (5) relative to the second support frame (32) are adjusted, the fixing device (2) is driven to move in the vertical direction.

8. The thermal compensation device according to claim 7, characterized in that: The first support frame (31) is provided with a plurality of first mounting holes (310), and each of the first mounting holes (310) is arranged at intervals along the vertical direction; the second support frame (32) is provided with a plurality of second mounting holes (320), and each of the second mounting holes (320) is arranged at intervals along the vertical direction; each of the first mounting holes (310) is arranged in a one-to-one correspondence with each of the second mounting holes (320); The fixing device (2) is connected to the first support frame (31) and the second support frame (32) respectively by passing one end of the first connecting rod (4) away from the fixing device (2) through any one of the first mounting holes (310); and one end of the second connecting rod (5) away from the fixing device (2) is passed through the corresponding second mounting hole (320).

9. The thermal compensation device according to claim 8, characterized in that: The first support frame (31) comprises a first mounting portion (311) and a first connecting portion (312); the first mounting portion (311) is connected to the first connecting portion (312), and the first connecting portion (312) is located below the first mounting portion (311); the first mounting portion (311) is used for being fixedly connected to the shaft assembly (200); the first connecting portion (312) extends along the vertical direction, and a plurality of first mounting holes (310) are provided on the first connecting portion (312), and the first mounting holes (310) are spaced apart along the extending direction of the first connecting portion (312); The second support frame (32) comprises a second mounting portion (321) and a second connecting portion (322), wherein the second mounting portion (321) is connected to the second connecting portion (322), and the second connecting portion (322) is located below the second mounting portion (321); the second mounting portion (321) is used for being fixedly connected to the shaft assembly (200); the second connecting portion (322) extends along the vertical direction, and a plurality of second mounting holes (320) are provided on the second connecting portion (322), and the second mounting holes (320) are spaced apart along the extension direction of the second connecting portion (322); and the first connecting portion (312) and the second connecting portion (322) are arranged opposite to each other.

10. A numerically controlled machine tool, characterized in that: include: A thermal compensation device as claimed in any one of claims 1 to 9.

11. A thermal compensation method, characterized in that: The thermal compensation method is applied to the thermal compensation device described in any one of claims 1 to 9; the thermal compensation method comprises: Before the machine tool is operated, determine the initial output voltage of the displacement detection device (1) ; When the machine tool is running, the current output voltage of the displacement detection device (1) is obtained. ; According to the current output voltage of the displacement detection device (1) and the initial output voltage of the displacement detection device (1) , adaptively adjusting the position of the spindle in the vertical direction to achieve error compensation; Wherein, n is the number of detections performed by the displacement detection device (1), and n≥1.

12. The thermal compensation method according to claim 11, characterized in that: The displacement detection device (1) is used according to the current output voltage of the displacement detection device (1) and the initial output voltage of the displacement detection device (1) , adaptively adjusting the position of the spindle in the vertical direction to achieve error compensation, comprising: Calculate the current output voltage With the initial output voltage The first voltage difference ; The absolute value of the first voltage difference The sensitivity of the displacement detection device (1) The first voltage difference is compared and , determine the error compensation direction of the spindle in the vertical direction; According to the absolute value of the first voltage difference The sensitivity of the displacement detection device (1) and adjusting the position of the spindle in the vertical direction based on the comparison result and the determined error compensation direction; The sensitivity of the displacement detection device (1) is The unit is .

13. The thermal compensation method according to claim 12, characterized in that: The absolute value of the first voltage difference The sensitivity of the displacement detection device (1) The method of adjusting the position of the spindle in the vertical direction based on the comparison result and the determined error compensation direction comprises: when 1, and when it is determined that the error compensation direction of the spindle is vertically upward, the spindle is controlled to move upward 1 ; when 1, and when it is determined that the error compensation direction of the spindle is vertically downward, the spindle is controlled to move downward 1 .

14. The thermal compensation method according to claim 12, characterized in that: The first voltage difference , a method for determining an error compensation direction of the spindle in a vertical direction, comprising: According to the first voltage difference , determining the thermal displacement direction of the spindle; Determining the error compensation direction of the spindle in the vertical direction according to the thermal displacement direction of the spindle; When the thermal displacement direction of the spindle is vertically upward, determining the error compensation direction of the spindle in the vertical direction to be vertically downward; When the thermal displacement direction of the spindle is vertically downward, the error compensation direction of the spindle in the vertical direction is determined to be vertically upward.

15. The thermal compensation method according to claim 14, characterized in that: The first voltage difference , a method for determining the thermal displacement direction of the spindle comprises: when When , the thermal displacement direction of the main axis is vertically upward; when When , the thermal displacement direction of the main axis is vertically downward.

16. The thermal compensation method according to claim 11, characterized in that: The thermal compensation method further comprises: Determining whether the rotation speed of the spindle is switched; When the rotation speed of the spindle is switched, the next output voltage of the displacement detection device (1) is calculated. The current output voltage of the displacement detection device (1) The second voltage difference ; According to the second voltage difference , to determine whether the next output voltage of the displacement detection device (1) As the new initial output voltage of the displacement detection device (1) ; When the displacement detection device (1) outputs the next voltage As the new initial output voltage of the displacement detection device (1) When the new initial output voltage As a reference voltage, the thermal displacement detection of the spindle is restarted, and error compensation is performed on the spindle according to the detection result.

17. The thermal compensation method according to claim 16, characterized in that: The second voltage difference , to determine whether the next output voltage of the displacement detection device (1) As the new initial output voltage of the displacement detection device (1) methods, including: The second voltage difference With preset threshold Make comparisons; when When the displacement detection device (1) outputs the next voltage As the new initial output voltage of the displacement detection device (1) .

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