Method and device for monitoring elongation of machine tool lead screw shaft in real time

Abstract

The invention provides a method and device for monitoring elongation of a machine tool lead screw shaft in real time, and the method comprises the steps: a sensor detects the stress condition of a lead screw, and the sensor detects the stress condition of the lead screw and transmits the stress information to a first control system; the first control system calculates the elongation of the lead screw shaft; elongation feedback: the first control system transmits the elongation information of the lead screw shaft into a second control system; and thermal compensation: the second control system controls the machine tool to perform lead screw thermal compensation. The problems that the overall temperature change of the lead screw cannot be comprehensively evaluated and the thermal compensation model is unreliable in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the field of machine tool precision control, and in particular to a method and a device for real-time monitoring of the elongation of a machine tool lead screw shaft. Background Art

[0002] At present, the length of international and domestic lead screws will generally increase by 12 microns per meter when the temperature rises by 1°C. This deformation is totally unacceptable for machine tools that require accuracy within 8 microns per meter.

[0003] In the prior art, the screw temperature is detected and a fitting model is used to predict the thermal elongation of the screw, and error compensation is performed in the system. However, the temperature differences between various parts of the screw are relatively large when the screw is thermally deformed, and the sensors can only be arranged in non-interfering places due to space limitations. Therefore, it is impossible to fully evaluate the overall temperature change of the screw. In addition, the temperatures at different positions of the screw are inconsistent, resulting in different thermal elongations at different positions. Therefore, the model error of predicting the overall elongation of the screw by local temperature changes is extremely large. Summary of the invention

[0004] The present invention solves the problem that the prior art cannot comprehensively evaluate the overall temperature change of the lead screw and the thermal compensation model is unreliable.

[0005] In order to solve the above problems, the present invention provides a method and device for real-time monitoring of the elongation of a machine tool screw shaft, wherein the method for real-time monitoring of the elongation of a machine tool screw shaft specifically includes: The sensor detects the force condition of the lead screw, and the sensor detects the force condition of the lead screw shaft and transmits the force information to the first control system; The first control system calculates the extension of the screw shaft; Elongation feedback: the first control system transmits the screw shaft elongation information to the second control system; Thermal compensation: the second control system controls the machine tool and implements thermal compensation of the screw shaft.

[0006] Compared with the prior art, the technical effect achieved by the present technical solution is as follows: Since the temperatures of various parts of the screw are not the same during operation, the temperature rise in the working friction area is higher, and the temperature rise in the non-working area is lower, the prior art method of accurately calculating the elongation of the screw by measuring the temperature of various parts of the screw is not accurate. The present invention measures the elongation of the screw by setting a sensor to detect the pressure change caused by the elongation of the screw on the equipment. This measurement method is more accurate than the prior art, and the sensor can also help determine whether the screw is installed in place.

[0007] Furthermore, the first control system calculates the elongation of the screw shaft, specifically including: the first control system calculates the elongation of the screw shaft according to Hooke's law, and there is the following formula for calculating the elongation of the screw shaft: F / S =E×△L / L; wherein, F is the total force of the sensor, S is the cross-sectional area of ​​the screw shaft, E is the elastic modulus of the elongation of the screw shaft, △L is the elongation of the screw shaft, and L is the length of the screw shaft between the bearings at both ends.

[0008] Compared with the existing technology, the technical effect achieved by this technical solution is: using Hooke's law to calculate the elongation of the screw shaft Furthermore, the sensor detects the force condition of the screw, specifically including: the pressure sensor detects the pressure of the outer ring of the machine tool bearing on the bearing pressure plate; the vibration sensor detects whether the machine tool bearing is vibrating. When the vibration sensor generates an abnormal signal, the data is fed back to the second control system, and the second control system sends an alarm signal.

[0009] Compared with the existing technology, the technical effect achieved by this technical solution is: the pressure sensor detects the pressure changes caused by the elongation of the screw shaft, and the vibration sensor detects whether the machine tool has abnormal vibration during the screw shaft processing, and feeds back to the second control system to alarm, which is convenient for manual intervention.

[0010] Furthermore, the pressure sensor detects the pressure of the outer ring of the machine tool bearing on the bearing pressure plate, specifically including: when the pressure sensor data increases, it means that the screw shaft is elongated; when the pressure data of the pressure sensor on one side is greater than the pressure data of the pressure sensor on the other side, it means that the screw shaft is bent and deformed, and the data is fed back to the second control system, and the second control system sends an alarm signal.

[0011] Compared with the prior art, the technical effect achieved by this technical solution is that the state of the screw shaft can be determined by the data changes of the pressure sensors on both sides of the machine tool.

[0012] A device for real-time monitoring of the elongation of a machine tool screw shaft, capable of executing any of the methods for real-time monitoring of the elongation of a machine tool screw shaft as described above, the device for real-time monitoring of the elongation of a machine tool screw shaft comprising: a machine tool body; a first base, arranged on the machine tool body; a first bearing, arranged in the first base; a first spacer ring, arranged on a side of the first bearing away from the first base, the first spacer ring abutting and contacting the first bearing; a sensor, at least arranged on a side of the first spacer ring close to the first bearing; a first bearing pressure ring, detachably arranged on the first base, the first bearing pressure ring abutting and contacting the first spacer ring; a first control system, communicatively connected to the sensor, for calculating the elongation of the screw shaft; a second control system, communicatively connected to the machine tool body and the first control system, for controlling the machine tool body to perform thermal compensation on the screw shaft.

[0013] Compared with the prior art, the technical effects achieved by the present technical solution are as follows: the first bearing supports and fixes the screw, the first spacer ring ensures the processing gap between the screw shaft and the machine tool to avoid unnecessary friction and vibration, the sensor is used to detect and transmit the pressure changes and vibrations caused by the elongation of the screw shaft during processing, the first bearing pressure ring further fixes the installation position of the first bearing and the first spacer ring to prevent abnormal vibrations during the processing of the screw shaft, the first control system is used to receive sensor information, calculate the elongation of the screw shaft and then feed it back to the second control system, the second control system controls the machine tool to perform thermal compensation on the screw shaft, and the first base is used to support the first bearing, the first spacer ring and the first bearing pressure ring.

[0014] Furthermore, the device for real-time monitoring of the extension of the machine tool screw shaft also includes: a second base, arranged on the machine tool body, the second base is arranged opposite to the first base; a second bearing, arranged in the second base; a second spacer ring, arranged on the side of the second bearing away from the second base, the second spacer ring is in abutment with the second bearing; the sensor is also arranged on the side of the second spacer ring close to the second bearing; a second bearing pressure ring, detachably arranged on the second base; wherein the first bearing, the first spacer ring, the first bearing pressure ring, the second bearing, the second spacer ring and the second bearing pressure ring are all located on the same axis.

[0015] Compared with the prior art, the technical effect achieved by this technical solution is as follows: the second base is used to support the second bearing, the second spacing ring and the second bearing pressure ring. The second base is arranged opposite to the first base and is used to fix the two ends of the lead screw so that the lead screw can be stably processed by the machine tool. Among them, the second bearing, the second spacing ring and the second bearing pressure ring have the same functions as the first bearing, the first spacing ring and the first bearing pressure ring.

[0016] Furthermore, the device for real-time monitoring of the extension of the machine tool screw shaft also includes a locking member, which is arranged on a side of the second bearing close to the second bearing pressure ring and / or on a side of the first bearing pressure ring away from the first bearing.

[0017] Compared with the prior art, the technical effect achieved by this technical solution is: locking the bearing position, preventing the bearing from loosening, and further fixing the axial position of the screw.

[0018] Furthermore, the device for real-time monitoring of the extension of the machine tool screw shaft also includes: a spacer sleeve, which is arranged in the first base, specifically between the locking member and the first spacer ring.

[0019] Compared with the prior art, the technical effects achieved by this technical solution are: reducing or isolating the temperature transfer of the screw shaft during the processing, and reducing the noise and vibration generated during the processing.

[0020] Furthermore, the device for real-time monitoring of the extension of the machine tool screw shaft also includes: a motor and a coupling.

[0021] The motor is arranged on a side of the first base away from the second base; the coupling is arranged in the first base, and the coupling is connected to the motor.

[0022] Compared with the prior art, the technical effect achieved by this technical solution is: the coupling connects the screw shaft and the motor to realize transmission, and makes the transmission connection firm, and the motor provides driving force to rotate the screw shaft.

[0023] Furthermore, the device for real-time monitoring of the extension of the machine tool screw shaft also includes: a dustproof part, which is arranged on the second bearing pressure ring.

[0024] Compared with the prior art, the technical effect achieved by the technical solution is: covering the second bearing pressure ring to protect the second bearing pressure ring and prevent dust from entering the second base to affect the processing of the screw shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A flowchart of a method for real-time monitoring of the elongation of a machine tool lead screw shaft provided by the present invention; Figure 2 A schematic diagram of the structure of a device for real-time monitoring of the elongation of a machine tool lead screw shaft provided by the present invention; Figure 3 A is a partial view of a device for real-time monitoring of the elongation of a machine tool screw shaft; Figure 4 is a schematic diagram of the position of the sensor on the spacer; Figure 5 B is a partial view of a device for real-time monitoring of the extension of a machine tool screw shaft.

[0026] Description of reference numerals: 1-first base; 11-first bearing; 12-first spacer ring; 13-first bearing pressure ring; 2-sensor; 5-second base; 51-second bearing; 52-second spacer ring; 53-second bearing pressure ring; 6-locking piece; 7-spacer sleeve; 8-motor; 81-coupling; 9-dustproof piece. DETAILED DESCRIPTION

[0027] The object of the present invention is to provide a method and device for real-time monitoring of the elongation of a machine tool screw shaft, so as to achieve accurate measurement of the elongation of the screw shaft and effectively perform thermal compensation.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the present invention provides a method for real-time monitoring of the elongation of a machine tool screw shaft, which specifically includes: The sensor detects the force condition of the lead screw, and the sensor detects the force condition of the lead screw shaft and transmits the force information to the first control system; The first control system calculates the extension of the screw shaft; Elongation feedback: the first control system transmits the screw shaft elongation information to the second control system; Thermal compensation: the second control system controls the machine tool and implements thermal compensation of the screw shaft.

[0030] In the prior art, since the temperatures of various parts of the screw are not the same during operation, the temperature rise in the working friction area is higher, and the temperature rise in the non-working area is lower, and the sensor can only be arranged in a place that does not interfere with the processing, the measurement method of accurately calculating the elongation of the screw by measuring the temperature of various parts of the screw in the prior art is not accurate. Many parts of the screw shaft can only be measured non-contactly. Due to the influence of the working environment of the machine tool, the oil mist and water mist in the air will affect the accuracy of the non-contact measurement, causing errors in the temperature sensor measurement data. The present invention measures the elongation of the screw by setting a pressure sensor to detect the pressure change caused by the elongation of the screw on the equipment. Since both ends of the sensor are covered by the workpiece and are not affected by the environment, the accuracy is higher, and the sensor can also help determine whether the screw is installed in place and whether the installation accuracy is up to standard.

[0031] The first control system calculates the elongation of the screw shaft, specifically including the first control system calculating the elongation of the screw shaft according to Hooke's law, and there is the following formula for calculating the elongation of the screw shaft: F / S =E×△L / L; wherein F is the total force of the sensor, S is the cross-sectional area of ​​the screw shaft, E is the elastic modulus of the elongation of the screw shaft, △L is the elongation of the screw shaft, and L is the length of the screw shaft between the bearings at both ends.

[0032] The sensor detects the force condition of the screw, specifically including the pressure sensor detecting the pressure of the outer ring of the machine tool bearing on the bearing pressure plate; the vibration sensor detects whether the machine tool bearing is vibrating. When the vibration sensor generates an abnormal signal, the data is fed back to the second control system, and the second control system sends an alarm signal.

[0033] The pressure sensor detects the pressure change caused by the extension of the screw shaft, and the vibration sensor detects whether the machine tool has abnormal vibration during the screw shaft processing, and feeds back to the second control system to alarm, facilitating manual intervention.

[0034] The pressure sensor detects the pressure of the outer ring of the machine tool bearing on the bearing pressure plate. Specifically, when the pressure sensor data on both sides increases evenly, it means that the screw shaft is elongated; when the pressure data of the pressure sensor on one side is greater than the pressure data of the pressure sensor on the other side, it means that the screw shaft is bent and deformed. The data is fed back to the second control system, and the second control system sends an alarm signal, so that the state of the screw shaft can be judged by the data changes of the pressure sensors on both sides of the machine tool.

[0035] like Figure 2 , Figure 3 and Figure 4 As shown, the present invention also provides a device for real-time monitoring of the elongation of a machine tool screw shaft, which can execute the method for real-time monitoring of the elongation of a machine tool screw shaft as described in any of the above items, and the device for real-time monitoring of the elongation of a machine tool screw shaft comprises: a machine tool body (not shown in the figure); a first base 1, arranged on the machine tool body; a first bearing 11, arranged in the first base 1; a first spacer ring 12, arranged on a side of the first bearing 11 away from the first base 1, and the first spacer ring 12 is in abutment with the first bearing 11; a sensor 2, at least arranged on a side of the first spacer ring 12 close to the first bearing 11; a first bearing pressure ring 13, detachably arranged on the first base 1, and the first bearing pressure ring 13 is in abutment with the first spacer ring 12; a first control system (not shown in the figure), which is communicated with the sensor and is used to calculate the elongation of the screw shaft; a second control system (not shown in the figure), which is communicated with the machine tool body and the first control system, and is used to control the machine tool body to perform thermal compensation on the screw shaft.

[0036] Specifically, in this embodiment, the first spacer ring 12 abuts against the outer ring of the first bearing 11 .

[0037] The sensors 2 are evenly distributed circumferentially on the first spacing ring 12, including the inner ring, the middle ring and the outer ring. The inner ring is close to the inner edge of the first spacing ring 12, the outer ring is close to the outer edge of the first spacing ring 12, and the middle ring is located between the inner ring and the outer ring. The inner ring and the outer ring are pressure sensors, and the middle ring is a vibration sensor. The pressure sensors and vibration sensors of the inner ring and the outer ring are all staggered to more comprehensively detect the pressure of the outer ring of the bearing on the support surface.

[0038] The first bearing 11 supports and fixes the screw, the first spacer ring 12 ensures the processing gap between the screw shaft and the machine tool to avoid unnecessary friction and vibration, the sensor is used to detect and transmit the pressure changes and vibrations caused by the elongation of the screw shaft during processing, the first bearing pressure ring 13 further fixes the installation position of the first bearing 11 and the first spacer ring 12 to prevent abnormal vibration during the processing of the screw shaft, the first control system is used to receive sensor information, calculate the elongation of the screw shaft and then feed it back to the second control system, the second control system controls the machine tool to perform thermal compensation on the screw shaft, and the first base 1 is used to support the first bearing 11, the first spacer ring 12 and the first bearing pressure ring 13.

[0039] like Figure 5As shown, the device for real-time monitoring of the extension of the machine tool screw shaft also includes a second base 5, which is arranged on the machine tool body, and the second base 5 is arranged opposite to the first base 1; a second bearing 51, which is arranged in the second base 5; a second spacer ring 52, which is arranged on the side of the second bearing 51 away from the second base 5, and the second spacer ring 52 is in abutment with the second bearing 51; the sensor 2 is also arranged on the side of the second spacer ring 52 close to the second bearing 51; the second bearing pressure ring 53 is detachably arranged on the second base 5; wherein the first bearing 11, the first spacer ring 12, the first bearing pressure ring 13, the second bearing 51, the second spacer ring 52 and the second bearing pressure ring 53 are all located on the same axis.

[0040] The sensors 2 are also evenly distributed in the circumferential direction on the second spacing ring 52 , the inner ring and the outer ring are pressure sensors, and the middle ring is a vibration sensor.

[0041] The second base 5 is used to support the second bearing 51, the second spacing ring 52 and the second bearing pressure ring 53. The second base 5 is arranged opposite to the first base 1, and is used to fix the two ends of the screw so that the screw can be stably processed by the machine tool. Among them, the second bearing 51 supports and fixes the screw, and the second spacing ring 52 ensures the processing gap between the screw shaft and the machine tool to avoid unnecessary friction and vibration. The sensor is used to detect and transmit the pressure changes and vibrations caused by the elongation of the screw shaft during processing. The second bearing pressure ring 53 further fixes the installation position of the second bearing 51 and the second spacing ring 52 to prevent abnormal vibration during the processing of the screw shaft.

[0042] Refer again Figure 3 and Figure 5 The device for real-time monitoring of the extension of the machine tool screw shaft also includes a locking member 6. The locking member 6 is arranged on a side of the second bearing 51 close to the second bearing pressure ring 53, and / or, is arranged on a side of the first bearing pressure ring 13 away from the first bearing 11.

[0043] Lock the bearing position to prevent the bearing from loosening and further fix the axial position of the screw.

[0044] like Figure 3 As shown, the device for real-time monitoring of the extension of the machine tool screw shaft also includes a spacer 7 , which is arranged in the first base 1 , specifically between the locking member 6 and the first spacer ring 12 .

[0045] Reduce or cut off the temperature transfer of the screw shaft during processing, and reduce the noise and vibration generated during processing.

[0046] The device for real-time monitoring of the extension of the machine tool lead screw shaft also includes a motor 8 and a coupling 81.

[0047] The motor 8 is disposed on a side of the first base 1 away from the second base 5 ; the coupling 81 is disposed in the first base 1 , and the coupling 81 is connected to the motor 8 .

[0048] The coupling 81 connects the screw shaft and the motor 8 to realize transmission and make the transmission connection firm. The motor 8 provides driving force to rotate the screw shaft.

[0049] The device for real-time monitoring of the extension of the machine tool screw shaft also includes a dustproof member 9. The dustproof member 9 is arranged on the second bearing pressure ring 53.

[0050] The second bearing pressing ring 53 is covered to protect the second bearing pressing ring 53 and prevent dust from entering the second base 5 to affect the processing of the screw shaft.

[0051] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for real-time monitoring of the elongation of a machine tool screw shaft. It is characterized in that Specifically include: The sensor detects the force condition of the lead screw, and the sensor detects the force condition of the lead screw shaft and transmits the force information to the first control system; The first control system calculates the extension of the screw shaft; Elongation feedback: the first control system transmits the screw shaft elongation information to the second control system; Thermal compensation: the second control system controls the machine tool and implements thermal compensation of the screw shaft.

2. The method for real-time monitoring of the elongation of a machine tool screw shaft according to claim 1, It is characterized in that The first control system calculates the extension of the screw shaft, specifically including: The first control system calculates the extension of the screw shaft according to Hooke's law. The following formula exists for calculating the extension of the screw shaft: F / S=E×△L / L; Among them, F is the total force of the sensor, S is the cross-sectional area of ​​the screw shaft, E is the elastic modulus of the screw shaft elongation, △L is the elongation of the screw shaft, and L is the length of the screw shaft between the bearings at both ends.

3. The method for real-time monitoring of the elongation of a machine tool screw shaft according to claim 2, It is characterized in that The sensor detects the force condition of the lead screw, specifically including: The pressure sensor detects the pressure of the outer ring of the machine tool bearing on the bearing pressure plate; The vibration sensor detects whether the machine tool bearing is vibrating. When the vibration sensor generates an abnormal signal, the data is fed back to the second control system, and the second control system sends out an alarm signal.

4. The method for real-time monitoring of the elongation of a machine tool screw shaft according to claim 3, It is characterized in that The pressure sensor detects the pressure of the machine tool bearing outer ring on the bearing pressure plate, specifically including: When the pressure sensor data increases, it means that the screw shaft is extended; When the pressure data of the pressure sensor on one side is greater than the pressure data of the pressure sensor on the other side, it indicates that the screw shaft is bent and deformed, and the data is fed back to the second control system, which sends out an alarm signal.

5. A device for real-time monitoring of the elongation of a machine tool screw shaft, capable of executing the method for real-time monitoring of the elongation of a machine tool screw shaft as claimed in any one of claims 1 to 4, It is characterized in that The device for real-time monitoring of the elongation of the machine tool screw shaft comprises: Machine tool body; A first base, disposed on the machine tool body; A first bearing, disposed in the first base; A first spacer ring is provided on a side of the first bearing away from the first base, and the first spacer ring is in abutment contact with the first bearing; A sensor, at least disposed on one side of the first spacer ring close to the first bearing; A first bearing pressure ring is detachably arranged on the first base, and the first bearing pressure ring is in abutment contact with the first spacer ring; A first control system, in communication with the sensor, for calculating the elongation of the lead screw shaft; The second control system is communicatively connected with the machine tool body and the first control system, and is used for controlling the machine tool body to perform thermal compensation on the screw shaft.

6. The device for real-time monitoring of the extension of a machine tool screw shaft according to claim 5, It is characterized in that Also includes: A second base, disposed on the machine tool body, the second base being disposed opposite to the first base; A second bearing is disposed in the second base; A second spacer ring is provided on a side of the second bearing away from the second base, and the second spacer ring is in abutment contact with the second bearing; The sensor is also arranged on one side of the second spacer ring close to the second bearing; A second bearing pressure ring, detachably disposed on the second base; The first bearing, the first spacer ring, the first bearing pressure ring, the second bearing, the second spacer ring and the second bearing pressure ring are all located on the same axis.

7. The device for real-time monitoring of the extension of a machine tool screw shaft according to claim 6, It is characterized in that Also includes: The locking member is arranged on a side of the second bearing close to the second bearing pressure ring, and / or is arranged on a side of the first bearing pressure ring away from the first bearing.

8. The device for real-time monitoring of the extension of a machine tool screw shaft according to claim 7, It is characterized in that Also includes: The spacer sleeve is arranged in the first base, specifically between the locking member and the first spacer ring.

9. The device for real-time monitoring of the extension of a machine tool screw shaft according to claim 8, It is characterized in that Also includes: A motor is arranged on a side of the first base away from the second base; A coupling is arranged in the first base, and the coupling is connected to the motor.

10. The device for real-time monitoring of the elongation of a machine tool screw shaft according to any one of claims 6 to 9, It is characterized in that Also includes: The dustproof part is arranged on the second bearing pressure ring.

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