Method and device for monitoring elongation of a machine tool screw spindle in real time

Abstract

The application provides a method and device for monitoring elongation of a machine tool screw shaft in real time, and the method comprises the following steps: a sensor detects force acting on the screw, the sensor detects the force acting on the screw and transmits force information to a first control system; the first control system calculates elongation of the screw shaft; elongation feedback, the first control system transmits elongation information of the screw shaft to a second control system; and thermal compensation, the second control system controls the machine tool to implement thermal compensation of the screw. The application solves the problem that the prior art cannot comprehensively evaluate overall temperature change of the screw and the thermal compensation model is unreliable.

Description

Technical Field

[0001] This invention relates to the field of machine tool precision control, and more specifically, to a method and apparatus for real-time monitoring of the elongation of a machine tool lead screw. Background Technology

[0002] Currently, both internationally and domestically, lead screws generally elongate by 12 micrometers per meter when the temperature rises by 1°C. This deformation is completely unacceptable for machine tools that require an accuracy of less than 8 micrometers per meter.

[0003] In existing technologies, the thermal elongation of the lead screw is predicted by detecting the temperature of the lead screw and fitting a model. Error compensation is then performed in the system. However, since the temperature difference between different parts of the lead screw is relatively large during thermal deformation, and the sensors can only be placed in non-interfering locations due to space limitations, it is impossible to comprehensively assess the overall temperature change of the lead screw. In addition, the temperature is inconsistent at different locations of the lead screw, resulting in different thermal elongations at different locations. Therefore, the model that predicts the overall elongation of the lead screw by local temperature changes has a large error. Summary of the Invention

[0004] This invention addresses the problem that existing technologies cannot comprehensively assess the overall temperature change of the lead screw, and that thermal compensation models are unreliable.

[0005] To address the above problems, this invention provides a method and apparatus for real-time monitoring of the elongation of a machine tool leadscrew, wherein the method for real-time monitoring of the elongation of a machine tool leadscrew specifically includes: The sensor detects the force on the lead screw and transmits the force information to the first control system. The first control system calculates the lead screw shaft elongation; Elongation feedback: The first control system transmits the elongation information of the lead screw shaft to the second control system; Thermal compensation: The second control system controls the machine tool and implements thermal compensation for the lead screw shaft.

[0006] Compared to existing technologies, the technical effects achieved by this solution are as follows: Since the temperature of different parts of the lead screw is 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. Therefore, the existing method of accurately calculating the elongation of the lead screw by measuring the temperature of each part of the lead screw is not accurate. This invention calculates the elongation of the lead screw by setting up a sensor to detect the pressure change caused by the elongation of the lead screw to the equipment. This calculation method is more accurate than the existing technology, and the sensor can also help determine whether the lead screw is installed in place.

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

[0008] Compared to existing technologies, the technical effect achieved by this solution is: calculating the elongation of the lead screw shaft using Hooke's Law. Furthermore, the sensors detect the force on the lead screw, specifically including: a pressure sensor detects the pressure of the outer ring of the machine tool bearing on the bearing pressure plate; a vibration sensor detects whether the machine tool bearing vibrates. When the vibration sensor generates an abnormal signal, the data is fed back to the second control system, and the second control system issues an alarm signal.

[0009] Compared with existing technologies, the technical effects achieved by this solution are as follows: the pressure sensor detects the pressure change caused by the extension of the lead screw shaft, and the vibration sensor detects whether there is abnormal vibration of the machine tool during the machining process of the lead screw shaft, and feeds back to the second control system for alarm, which facilitates 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, when the pressure sensor data increases, it indicates that the lead screw shaft has elongated; when the pressure data of one side pressure sensor is greater than the pressure data of the other side pressure sensor, it indicates that the lead screw shaft has bent and deformed. The data is fed back to the second control system, and the second control system issues an alarm signal.

[0011] Compared with existing technologies, the technical effect achieved by this solution is that the state of the lead 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 lead screw shaft, capable of performing the method for real-time monitoring of the elongation of a machine tool lead screw shaft as described in any of the preceding claims, the device comprising: a machine tool body; a first base disposed on the machine tool body; a first bearing disposed within the first base; a first spacer ring disposed on the side of the first bearing away from the first base, the first spacer ring abutting against the first bearing; a sensor disposed at least on the side of the first spacer ring near the first bearing; a first bearing pressure ring detachably disposed on the first base, the first bearing pressure ring abutting against the first spacer ring; a first control system communicatively connected to the sensor, used for calculating the elongation of the lead screw shaft; and a second control system communicatively connected to the machine tool body and the first control system, used for controlling the machine tool body to perform thermal compensation on the lead screw shaft.

[0013] Compared with existing technologies, the technical effects achieved by this solution are as follows: the first bearing supports and fixes the lead screw; the first spacer ring ensures the machining clearance between the lead screw shaft and the machine tool, avoiding unnecessary friction and vibration; the sensor is used to detect and transmit the pressure changes and vibrations caused by the elongation of the lead screw shaft during machining; the first bearing pressure ring further fixes the installation position of the first bearing and the first spacer ring, preventing abnormal vibrations from occurring during the machining of the lead screw shaft; the first control system is used to receive sensor information, calculate the elongation of the lead 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 lead 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 elongation of the machine tool lead screw shaft also includes: a second base, mounted on the machine tool body, with the second base opposite to the first base; a second bearing, located inside the second base; a second spacer ring, located on the side of the second bearing away from the second base, with the second spacer ring in contact with the second bearing; a sensor also located on the side of the second spacer ring near the second bearing; and a second bearing retaining ring, detachably mounted on the second base; wherein the first bearing, the first spacer ring, the first bearing retaining ring, the second bearing, the second spacer ring, and the second bearing retaining ring are all located on the same axis.

[0015] Compared to existing technologies, the technical effects achieved by this solution are as follows: The second base supports the second bearing, the second spacer ring, and the second bearing retaining ring. The second base is positioned opposite to the first base and is used to fix both ends of the lead screw, enabling the lead screw to be stably machined by the machine tool. The functions of the second bearing, the second spacer ring, and the second bearing retaining ring are the same as those of the first bearing, the first spacer ring, and the first bearing retaining ring.

[0016] Furthermore, the device for real-time monitoring of the elongation of the machine tool lead screw shaft also includes a locking element. The locking element is located on the side of the second bearing near the second bearing pressure ring, and / or on the side of the first bearing pressure ring away from the first bearing.

[0017] Compared with existing technologies, the technical effects achieved by this technical solution are: locking the bearing position, preventing the bearing from loosening, and further fixing the axial position of the lead screw.

[0018] Furthermore, the device for real-time monitoring of the machine tool lead screw elongation also includes a spacer. This spacer is located within the first base, specifically between the locking element and the first spacer ring.

[0019] Compared with existing technologies, the technical effects achieved by this technical solution are: reducing or isolating the temperature transmission of the lead screw shaft during the machining process, and reducing the noise and vibration generated during the machining process.

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

[0021] The motor is located on the side of the first base away from the second base; the coupling is located inside the first base and is connected to the motor.

[0022] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the coupling connects the lead screw shaft and the motor to realize transmission, and makes the transmission connection firm; the motor provides driving force to make the lead screw shaft rotate.

[0023] Furthermore, the device for real-time monitoring of the elongation of the machine tool lead screw shaft also includes a dustproof component, which is located on the second bearing pressure ring.

[0024] Compared with the existing technology, the technical effect achieved by this technical solution is: to cover the second bearing pressure ring, which is used to protect the second bearing pressure ring and prevent dust from entering the second base and affecting the machining of the lead screw shaft. Attached Figure Description

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

[0026] Explanation of reference numerals in the attached figures: 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 component; 7-Spacer sleeve; 8-Motor; 81-Coupling; 9-Dustproof component. Detailed Implementation

[0027] The purpose of this invention is to provide a method and apparatus for real-time monitoring of the elongation of a machine tool lead screw shaft, so as to accurately calculate the elongation of the lead screw shaft and effectively perform thermal compensation.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be 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 lead screw shaft, specifically including: The sensor detects the force on the lead screw and transmits the force information to the first control system. The first control system calculates the lead screw shaft elongation; Elongation feedback: The first control system transmits the elongation information of the lead screw shaft to the second control system; Thermal compensation: The second control system controls the machine tool and implements thermal compensation for the lead screw shaft.

[0030] In existing technologies, the temperature varies across different parts of the leadscrew during operation, with higher temperature rises in the working friction area and lower temperatures in the non-working area. Furthermore, sensors can only be placed in locations that do not interfere with machining. Therefore, existing methods for accurately calculating leadscrew elongation by measuring the temperature of various parts of the leadscrew are inaccurate. Many parts of the leadscrew shaft can only be measured using non-contact methods. However, the machine tool's working environment, including oil and water mists in the air, can affect the accuracy of non-contact measurements, causing errors in the temperature sensor data. This invention calculates leadscrew elongation by using a pressure sensor to detect the pressure change caused by the leadscrew's elongation. Because the sensor's ends are covered by the workpiece, it is unaffected by the environment, resulting in higher accuracy. Additionally, the sensor can help determine whether the leadscrew is installed correctly and whether the installation accuracy meets standards.

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

[0032] The sensors detect the force on the lead screw, specifically including a pressure sensor that detects the pressure of the outer ring of the machine tool bearing on the bearing plate; and a vibration sensor that 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, which then issues an alarm signal.

[0033] The pressure sensor detects the pressure change caused by the extension of the lead screw shaft, and the vibration sensor detects whether there is abnormal vibration of the machine tool during the machining process of the lead screw shaft, and feeds back to the second control system for alarm, so as to facilitate 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 data from both pressure sensors increases uniformly, it indicates that the lead screw shaft is elongated; when the pressure data from one pressure sensor is greater than that from the other pressure sensor, it indicates that the lead screw shaft is bent and deformed. The data is fed back to the second control system, which issues an alarm signal, enabling the condition of the lead screw shaft to be determined by the changes in the data from 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 lead screw shaft, capable of performing the method for real-time monitoring of the elongation of a machine tool lead screw shaft as described in any of the preceding claims. The device for real-time monitoring of the elongation of a machine tool lead screw shaft includes: a machine tool body (not shown in the figure); a first base 1 disposed on the machine tool body; a first bearing 11 disposed within the first base 1; a first spacer ring 12 disposed on the side of the first bearing 11 away from the first base 1, the first spacer ring 12 abutting against the first bearing 11; a sensor 2 disposed at least on the side of the first spacer ring 12 near the first bearing 11; a first bearing pressure ring 13 detachably disposed on the first base 1, the first bearing pressure ring 13 abutting against the first spacer ring 12; a first control system (not shown in the figure), communicatively connected to the sensor, for calculating the elongation of the lead screw shaft; and a second control system (not shown in the figure), communicatively connected to the machine tool body and the first control system, for controlling the machine tool body to perform thermal compensation on the lead screw shaft.

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

[0037] Sensors 2 are circumferentially evenly distributed on the first spacer ring 12, consisting of an inner ring, a middle ring, and an outer ring. The inner ring is located near the inner edge of the first spacer ring 12, the outer ring is located near the outer edge of the first spacer ring 12, and the middle ring is located between the inner and outer rings. The inner and outer rings are pressure sensors, and the middle ring is a vibration sensor. The pressure sensors and vibration sensors on the inner and outer rings are staggered to comprehensively detect the pressure of the bearing outer ring on the support surface.

[0038] The first bearing 11 supports and fixes the lead screw, the first spacer ring 12 ensures the machining clearance between the lead screw shaft and the machine tool to avoid unnecessary friction and vibration, the sensor is used to detect and transmit the pressure changes and vibration caused by the elongation of the lead screw shaft during machining, 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 from occurring during the machining of the lead screw shaft, the first control system is used to receive sensor information, calculate the elongation of the lead 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 lead 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 elongation of the machine tool lead screw shaft also includes a second base 5, which is mounted on the machine tool body and is positioned opposite to the first base 1; a second bearing 51, which is located inside the second base 5; a second spacer ring 52, which is located on the side of the second bearing 51 away from the second base 5 and is in contact with the second bearing 51; a sensor 2 is also located on the side of the second spacer ring 52 near the second bearing 51; and a second bearing pressure ring 53, which is detachably mounted on the second base 5. 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] Sensor 2 is also circumferentially and evenly distributed on the second spacer ring 52. The inner and outer rings are pressure sensors, and the middle ring is a vibration sensor.

[0041] The second base 5 supports the second bearing 51, the second spacer ring 52, and the second bearing retaining ring 53. The second base 5 is positioned opposite the first base 1 and is used to fix both ends of the lead screw, enabling stable machining of the lead screw by the machine tool. The second bearing 51 supports and fixes the lead screw, the second spacer ring 52 ensures the machining clearance between the lead screw shaft and the machine tool, avoiding unnecessary friction and vibration. The sensor detects and transmits pressure changes and vibrations caused by the elongation of the lead screw shaft during machining. The second bearing retaining ring 53 further fixes the installation position of the second bearing 51 and the second spacer ring 52, preventing abnormal vibrations during lead screw shaft machining.

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

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

[0044] like Figure 3 As shown, the device for real-time monitoring of the elongation of the machine tool lead screw also includes a spacer 7. It is located inside the first base 1, specifically between the locking member 6 and the first spacer ring 12.

[0045] Reduce or isolate the temperature transmission of the lead screw shaft during the machining process, and reduce the noise and vibration generated during the machining process.

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

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

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

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

[0050] The second bearing retaining ring 53 is covered to protect it and prevent dust from entering the second base 5 and affecting the machining of the lead screw shaft.

[0051] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A device for real-time monitoring of the elongation of a machine tool lead screw shaft, characterized in that, The device for real-time monitoring of the elongation of the machine tool lead screw includes: Machine tool body; The first base is disposed on the machine tool body; The first bearing is disposed inside the first base; A first spacer ring is disposed on the side of the first bearing away from the first base, and the first spacer ring abuts against the first bearing. The sensor is disposed at least on the side of the first spacer ring near the first bearing; The first bearing retaining ring is detachably mounted on the first base, and the first bearing retaining ring abuts against the first spacer ring. The first control system is communicatively connected to the sensor and is used to calculate the elongation of the lead screw shaft. The second control system is communicatively connected to the machine tool body and the first control system, and is used to control the machine tool body to perform thermal compensation on the lead screw axis. The sensors are evenly distributed circumferentially in the first spacer ring. The sensors include an inner ring sensor, a middle ring sensor, and an outer ring sensor. The inner ring sensor and the outer ring sensor are both pressure sensors, and the middle ring sensor is a vibration sensor.

2. The device for real-time monitoring of machine tool lead screw elongation according to claim 1, characterized in that, Also includes: The second base is disposed on the machine tool body, and the second base is arranged opposite to the first base; The second bearing is located inside the second base; The second spacer ring is disposed on the side of the second bearing away from the second base, and the second spacer ring abuts against the second bearing; The sensor is also disposed on the second spacer ring on the side near the second bearing; The second bearing pressure ring is detachably mounted 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.

3. The device for real-time monitoring of machine tool lead screw elongation according to claim 2, characterized in that, Also includes: A locking element is provided on the side of the second bearing near the second bearing pressure ring, and / or on the side of the first bearing pressure ring away from the first bearing.

4. The device for real-time monitoring of machine tool lead screw elongation according to claim 3, characterized in that, Also includes: A spacer sleeve is disposed inside the first base, specifically between the locking member and the first spacer ring.

5. The device for real-time monitoring of machine tool lead screw elongation according to claim 4, characterized in that, Also includes: The motor is located on the side of the first base away from the second base; A coupling is disposed within the first base and is connected to the motor.

6. The device for real-time monitoring of machine tool lead screw elongation according to any one of claims 2 to 5, characterized in that, Also includes: A dustproof component is provided on the second bearing pressure ring.

7. A method for real-time monitoring of the elongation of a machine tool lead screw shaft, characterized in that, This is achieved by the device for real-time monitoring of the elongation of the machine tool lead screw shaft as described in any one of claims 1 to 6, and the specific steps of the method for real-time monitoring of the elongation of the machine tool lead screw shaft include: The sensor detects the force on the lead screw and transmits the force information to the first control system. The first control system calculates the lead screw shaft elongation; Elongation feedback: The first control system transmits the elongation information of the lead screw shaft to the second control system; Thermal compensation: The second control system controls the machine tool and implements thermal compensation for the lead screw shaft.

8. The method for real-time monitoring of the elongation of a machine tool lead screw shaft according to claim 7, characterized in that, The first control system calculates the lead screw shaft elongation, specifically including: The first control system calculates the lead screw elongation according to Hooke's law, and the following formula exists for calculating the lead screw elongation: F / S=E×△L / L; Where F is the total force on the sensor, S is the cross-sectional area of ​​the lead screw shaft, E is the elastic modulus of the lead screw shaft elongation, ΔL is the elongation of the lead screw shaft, and L is the length of the lead screw shaft between the bearings at both ends.

9. The method for real-time monitoring of the elongation of a machine tool lead screw shaft according to claim 8, characterized in that, The sensor detects the force on 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, which then issues an alarm signal.

10. The method for real-time monitoring of the elongation of a machine tool lead screw shaft according to claim 9, characterized in that, 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 indicates that the lead screw shaft has elongated. When the pressure data from one pressure sensor is greater than that from the other pressure sensor, it indicates that the lead screw shaft has bent and deformed. The data is fed back to the second control system, which then issues an alarm signal.

Images