Device, machine tool and method for adjusting friction torque of ball screw

Abstract

The invention relates to the technical field of machine tool precision control, in particular to a device for adjusting the friction torque of a ball screw, a machine tool for adjusting the friction torque of the ball screw and a method for adjusting the friction torque of the ball screw. The device comprises a ball screw, a prefabricated grinding nut and a jacking piece, the prefabricated grinding nut is used for grinding the ball screw, the shape of the prefabricated grinding nut is matched with that of the ball screw, and the prefabricated grinding nut is tightly attached to a ball screw raceway; the jacking piece is connected with the prefabricated grinding nut and drives the prefabricated grinding nut to be close to or away from the ball screw. When the nominal diameter of the ball screw changes in the working process, the ball screw is ground through the prefabricated grinding nut. The device can control the friction torque of the ball screw nut pair in real time, the stability of a machine tool in the operation process is effectively improved, and the machining quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool precision control, and in particular to a device for adjusting the friction torque of a ball screw, a machine tool for adjusting the friction torque of a ball screw, and a method for adjusting the friction torque of a ball screw. Background Art

[0002] Machine tools are the core production foundation of the entire equipment manufacturing industry, especially top-level machine tools such as ultra-high precision machine tools. Their technical level directly reflects the overall competitiveness of a country's manufacturing industry. As the transmission and positioning device of machine tools, the performance of ball screws also directly affects the overall processing level of machine tools. With the improvement of processing quality requirements, ball screws are required not only to meet the requirements of positioning accuracy and repeated positioning accuracy, but also to ensure that the friction torque fluctuation during the movement of the ball screw cannot be too large. The national standard GB / T 17587.3 quantitatively defines the fluctuation range of friction torque during the rotation of screw nut pairs of different sizes and different preloads. In the actual production process, the change of this torque fluctuation is often more difficult to guarantee than the stroke accuracy. At present, there is no practical and reliable method to improve the fluctuation of screw torque. Therefore, it is necessary to improve it. Summary of the invention

[0003] The invention solves the problem that the friction torque of a ball screw of a machine tool changes too much during operation, and provides a device capable of adjusting the friction torque of the ball screw in real time.

[0004] To solve the above problems, the present invention adopts the following technical solutions: a device for adjusting the friction torque of a ball screw: a ball screw, a prefabricated ground nut and a tightening piece, the prefabricated ground nut is used to grind the ball screw, the shape of the prefabricated ground nut matches the shape of the ball screw, and the prefabricated ground nut is tightly attached to the ball screw raceway; the tightening piece is connected to the prefabricated ground nut, and drives the prefabricated ground nut to approach or move away from the ball screw; when the nominal diameter of the ball screw changes during operation, the prefabricated ground nut grinds the ball screw.

[0005] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the friction torque will fluctuate during the movement of the ball screw nut pair. Since the size of the nut is constant, the main reason for this is the change in the size of the ball screw itself. The nominal diameters of the screws at different positions are different. The friction torque is large at the part with a large diameter, and small at the part with a small diameter. This device fixes the prefabricated grinding nut on the ball screw through a tightening member to limit the rotation of the prefabricated grinding nut. During the rotation of the ball screw, the prefabricated grinding nut will be subjected to the tightening force and rub against the screw, thereby achieving grinding and polishing of the entire screw. And according to the change of the friction torque during the rotation of the ball screw nut pair, different tightening forces are applied at different positions to improve the inconsistency of the nominal diameter after the screw grinding is completed, thereby improving the unstable friction torque during the movement of the screw nut pair, effectively improving the stability of the machine tool during operation, and improving the processing quality.

[0006] Furthermore, the prefabricated grinding nut includes: a first grinding wall and a second grinding wall, and the first grinding wall and the second grinding wall are symmetrically arranged on the ball screw raceway for grinding the ball screw.

[0007] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: by prefabricating two grinding nuts, and because the first grinding wall and the second grinding wall are symmetrically arranged on the ball screw raceway, when grinding the ball screw, they can act on the raceway from two opposite directions at the same time. In this way, the grinding force can be more evenly distributed in the circumferential direction of the raceway, avoiding the situation where the raceway is unevenly ground due to excessive or insufficient grinding force on one side. At the same time, the ball screw raceway usually has certain shape characteristics and precision requirements, and the symmetrically arranged first grinding wall and second grinding wall can better fit the shape of the raceway. During the grinding process, they can adaptively adjust the grinding action according to the actual shape of the raceway, more comprehensively cover the raceway surface, and ensure that all parts of the raceway can be effectively ground, thereby meeting the shape and precision requirements of the ball screw raceway and maintaining the good working performance of the ball screw.

[0008] Furthermore, the prefabricated grinding nut is provided with a nut mounting portion, and the tightening member is provided with a nut fixing portion, and the nut mounting portion and the nut fixing portion cooperate with each other to fix the prefabricated grinding nut.

[0009] Compared with the prior art, the technical effect achieved by adopting this technical solution is that the prefabricated ground nut can be firmly fixed on the jacking piece by the cooperation between the nut mounting portion of the prefabricated ground nut and the nut fixing portion of the jacking piece. When the jacking piece drives the prefabricated ground nut to approach or move away from the ball screw, and when the prefabricated ground nut performs a grinding operation on the ball screw, this stable connection can ensure that the prefabricated ground nut will not be displaced or shaken, thereby ensuring the accuracy and stability of the grinding action, which is conducive to improving the grinding quality of the ball screw and the adjustment accuracy of the friction torque.

[0010] Furthermore, the pressing member includes: a driving member and a connecting rod, the driving member is movably connected to the nut fixing part through the connecting rod, and the driving member drives the prefabricated grinding nut to approach or move away from the ball screw.

[0011] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the driving member is connected to the nut fixing part through a connecting rod, so that the tightening member can accurately control the tightening force of the prefabricated ground nut on the ball screw. The existence of the connecting rod can accurately transmit the driving force generated by the driving member to the prefabricated ground nut, thereby realizing the precise grinding of the ball screw. By adjusting the output force of the driving member, the grinding force of the prefabricated ground nut on the ball screw can be changed, thereby realizing fine adjustment of the friction torque of the ball screw to meet the requirements of the friction torque of the ball screw under different working conditions. The driving member can use an electric cylinder to provide pressure tightening. The greater the friction torque, the larger the nominal diameter of the ball screw, the greater the tightening force, and the higher the degree of grinding, which ultimately achieves the reduction of the fluctuation of the overall diameter change of the ball screw and ensures the reduction of the fluctuation of the friction torque over the full stroke of the screw.

[0012] Furthermore, the second object of the present invention is to provide a machine tool, which specifically comprises: a device for adjusting the friction torque of a ball screw as mentioned in any technical solution of the present invention. The beneficial effects thereof will not be described in detail here.

[0013] Furthermore, the machine tool includes: a guide rail, the guide rail is arranged parallel to the ball screw, and the tensioning member is also provided with a sliding groove, and the sliding groove is installed on the guide rail; when the device for adjusting the friction torque of the ball screw is working, the tensioning member slides within the guide rail travel through the sliding groove.

[0014] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: during the operation of the ball screw, since the prefabricated ground nut is fixed on the ball screw, the prefabricated ground nut will move on the guide rail with the tightening part. During the movement, it will be subjected to the tightening force and rub against the screw, thereby achieving the grinding and polishing of the entire screw.

[0015] Furthermore, the machine tool also includes a detection module, which includes: a force sensor, which is used to detect the tightening force of the tightening member on the prefabricated grinding nut, and the force sensor is arranged on the tightening member.

[0016] Compared with the existing technology, the technical effect achieved by adopting this technical solution is: by setting the detection module on the machine tool, the working state of the prefabricated grinding nut can be detected and fed back in real time, and the size of the top tightening force can be detected in real time by the force sensor. Since the size of the top tightening force is determined by the size of the friction torque, the larger the friction torque, the larger the nominal diameter of the ball screw, the larger the top tightening force, and the higher the degree of grinding, the overall diameter change fluctuation of the ball screw can be reduced, and the friction torque fluctuation of the ball screw can be reduced over the full stroke.

[0017] Furthermore, a third object of the present invention is to provide a method for adjusting the friction torque of a ball screw, which is applied to the device for adjusting the friction torque of a ball screw as mentioned in any technical solution of the present invention, comprising the steps of: Prefabricated ground nuts are made according to ball screws; Get the initial friction torque of the ball screw; The clamping member drives the prefabricated ground nut to be set close to the ball screw; Obtain the thrust of the tightening member during the operation of the ball screw; The push-out distance of the pressing member is changed according to the thrust force, so that the friction torque of the ball screw during the working process is proportional to the initial friction torque.

[0018] Compared with the existing technology, the technical effect achieved by adopting this technical scheme is as follows: according to the specific situation of the ball screw, a prefabricated ground nut is manufactured which fits perfectly with the ball screw raceway; while the ball screw rotates, the entire outer surface of the ball screw is ground in real time by the prefabricated ground nut, thereby ensuring that the friction torque fluctuation of the ball screw pair is reduced throughout its entire stroke.

[0019] Furthermore, the manufacturing of the prefabricated ground nut according to the ball screw specifically includes the following steps: Fill the grinding material into the semi-cylindrical mold; The semi-cylindrical mold is fixed on the ball screw, a prefabricated ground nut fitting the ball screw raceway is manufactured, and the ground nut is installed on the jacking part.

[0020] Compared with the prior art, the technical effect achieved by adopting this technical solution is: by filling the grinding raw material into the semi-cylindrical mold and fixing the semi-cylindrical mold on the ball screw to manufacture the prefabricated ground nut, it can ensure that the manufactured prefabricated ground nut is completely fitted with the ball screw raceway. This makes the grinding process more uniform and stable, thereby more accurately adjusting the friction torque of the ball screw and reducing uneven grinding and friction torque fluctuations caused by poor fitting.

[0021] Furthermore, the device is provided with a detection module, which includes: a force sensor and a friction torque detector, the force sensor is used to detect the size of the tightening force of the tightening member on the prefabricated grinding nut, and the force sensor and the friction torque detector are arranged on the tightening member; changing the push-out distance of the tightening member according to the thrust size, so that the friction torque of the ball screw during the working process is proportional to the initial friction torque, specifically including the steps of: When the friction torque of the ball screw is greater than the initial friction torque, increase the thrust of the clamping member; When the friction torque of the ball screw is less than the initial friction torque, reduce the thrust of the clamping member.

[0022] Compared with the prior art, the technical effect achieved by adopting this technical solution is: the force sensor can accurately detect the tightening force of the tightening member on the prefabricated ground nut, and combined with the friction torque detector, it can monitor the change of the friction torque of the ball screw in real time and accurately. Based on these precise detection data, the friction torque can be adjusted more accurately according to the relationship between the friction torque of the ball screw and the initial friction torque by changing the push-out distance of the tightening member, so that it is proportional to the initial friction torque, thereby achieving high-precision control of the friction torque of the ball screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the partial structure of a machine tool for adjusting the friction torque of a ball screw according to an embodiment of the present invention; Figure 2 In the embodiment of the present invention Figure 1 The structural schematic diagram of the device for adjusting the friction torque of the ball screw of the machine tool shown; Figure 3 For the embodiment of the present invention Figure 1 A schematic diagram of the first grinding wall structure of the prefabricated grinding nut shown; Figure 4 For the embodiment of the present invention Figure 1 A schematic structural diagram of a second grinding wall of a prefabricated grinding nut shown; Figure 5 For the embodiment of the present invention Figure 1 Another schematic diagram of the structure of the prefabricated ground nut shown; Explanation of the reference numerals: 10 - ball screw; 20 - tightening member; 201 - connecting rod; 202 - driving member; 203 - sliding groove; 204 - nut fixing portion; 30 - prefabricated grinding nut; 301 - first grinding wall; 302 - second grinding wall; 303 - nut mounting portion; 40 - force sensor. DETAILED DESCRIPTION

[0024] 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.

[0025] See also Figure 1-Figure 5 A device for adjusting the friction torque of a ball screw: a ball screw 10, a prefabricated ground nut 30 and a tightening piece 20, the prefabricated ground nut 30 is used to grind the ball screw 10, the shape of the prefabricated ground nut 30 matches the shape of the ball screw 10, and the prefabricated ground nut 30 is tightly attached to the raceway of the ball screw 10; the tightening piece 20 is connected to the prefabricated ground nut 30, and drives the prefabricated ground nut 30 to approach or move away from the ball screw 10; when the nominal diameter of the ball screw 10 changes during operation, the prefabricated ground nut 30 grinds the ball screw 10.

[0026] The friction torque will fluctuate during the movement of the ball screw 10 nut pair. Since the size of the nut is constant, the main reason for this is the change in the size of the ball screw 10 itself. The nominal diameters of the screws at different positions are different. The friction torque is large at the part with a large diameter, and small at the part with a small diameter. The device fixes the prefabricated grinding nut 30 on the ball screw 10 through the clamping member 20 to limit the rotation of the prefabricated grinding nut 30. During the rotation of the ball screw 10, the prefabricated grinding nut 30 will be subjected to the clamping force and rub against the screw, thereby achieving grinding and polishing of the entire screw. And according to the change in the friction torque during the rotation of the ball screw 10 nut pair, different clamping forces are applied at different positions to improve the inconsistency of the nominal diameter after the screw grinding is completed, thereby improving the unstable friction torque during the movement of the screw nut pair, effectively improving the stability of the machine tool during operation, and improving the processing quality.

[0027] Specifically, see Figure 3-Figure 5 The prefabricated grinding nut 30 includes: a first grinding wall 301 and a second grinding wall 302 . The first grinding wall 301 and the second grinding wall 302 are symmetrically arranged on the raceway of the ball screw 10 for grinding the ball screw 10 .

[0028] For example, the first grinding wall 301 and the second grinding wall 302 are configured as semi-cylinders to uniformly grind the ball screw 10 from two directions.

[0029] Since the first grinding wall 301 and the second grinding wall 302 are symmetrically arranged on the raceway of the ball screw 10, when the ball screw 10 is ground, they can act on the raceway from two opposite directions at the same time. This can ensure that the grinding force is distributed more evenly in the circumferential direction of the raceway, avoiding the situation where the raceway is unevenly ground due to excessive or insufficient grinding force on one side. At the same time, the raceway of the ball screw 10 usually has certain shape characteristics and precision requirements, and the symmetrically arranged first grinding wall 301 and second grinding wall 302 can better fit the shape of the raceway. During the grinding process, they can adaptively adjust the grinding action according to the actual shape of the raceway, more comprehensively cover the raceway surface, and ensure that all parts of the raceway can be effectively ground, thereby meeting the shape and precision requirements of the ball screw 10 raceway and maintaining the good working performance of the ball screw 10.

[0030] Specifically, see Figure 5 The prefabricated grinding nut 30 is provided with a nut mounting portion 303 , and the tightening member 20 is provided with a nut fixing portion 204 . The nut mounting portion 303 and the nut fixing portion 204 cooperate with each other to fix the prefabricated grinding nut 30 .

[0031] The prefabricated grinding nut 30 can be firmly fixed on the jacking member 20 by the nut mounting portion 303 of the prefabricated grinding nut 30 cooperating with the nut fixing portion 204 of the jacking member 20. When the jacking member 20 drives the prefabricated grinding nut 30 to approach or move away from the ball screw 10, and when the prefabricated grinding nut 30 performs a grinding operation on the ball screw 10, this stable connection can ensure that the prefabricated grinding nut 30 will not be displaced or shaken, thereby ensuring the accuracy and stability of the grinding action, which is conducive to improving the grinding quality of the ball screw 10 and the adjustment accuracy of the friction torque.

[0032] Furthermore, see Figure 2 The pressing member 20 includes: a driving member 202 and a connecting rod 201 . The driving member 202 is movably connected to the nut fixing portion 204 through the connecting rod 201 . The driving member 202 drives the prefabricated grinding nut 30 to approach or move away from the ball screw 10 .

[0033] For example, the driving member 202 may be an electric cylinder, which is convenient for installation and testing; For example again, the driving member 202 may be a gas cylinder, and the size of the pressing force can be determined by monitoring the change of gas pressure, thus saving detection modules.

[0034] The driving member 202 is connected to the nut fixing portion 204 through the connecting rod 201, so that the pressing member 20 can accurately control the pressing force of the prefabricated grinding nut 30 on the ball screw 10. The existence of the connecting rod 201 can accurately transfer the driving force generated by the driving member 202 to the prefabricated grinding nut 30, thereby realizing the precise grinding of the ball screw 10. By adjusting the output force of the driving member 202, the grinding force of the prefabricated grinding nut 30 on the ball screw 10 can be changed, thereby realizing the fine adjustment of the friction torque of the ball screw 10 to meet the requirements of the friction torque of the ball screw 10 under different working conditions. The driving member 202 can use an electric cylinder to provide pressure pressing. The larger the friction torque, the larger the nominal diameter of the ball screw 10, the greater the pressing force, and the higher the grinding degree, and finally realize the reduction of the fluctuation of the overall diameter change of the ball screw 10, and ensure the reduction of the fluctuation of the friction torque on the full stroke of the screw.

[0035] The second object of the present invention is to provide a machine tool, see Figure 1 The machine tool specifically comprises: the above-mentioned device for adjusting the friction torque of the ball screw 10. Its beneficial effects are not described in detail here.

[0036] like Figure 1 As shown, the machine tool also includes: a guide rail, which is arranged parallel to the ball screw 10, and the clamping member 20 is also provided with a sliding groove 203, and the sliding groove 203 is installed on the guide rail; when the device for adjusting the friction torque of the ball screw 10 is working, the clamping member 20 slides within the guide rail travel through the sliding groove 203.

[0037] During the operation of the ball screw 10, since the prefabricated ground nut 30 is fixed on the ball screw 10, the prefabricated ground nut 30 will move on the guide rail with the tightening member 20. During the movement, it will be subjected to the tightening force and rub against the screw, thereby achieving grinding and polishing of the entire screw.

[0038] like Figure 1-Figure 5 As shown, the machine tool further includes a detection module, which includes a force sensor 40 , which is used to detect the tightening force of the tightening member 20 on the prefabricated grinding nut 30 , and the force sensor 40 is arranged on the tightening member 20 .

[0039] By setting a detection module on the machine tool, the working status of the prefabricated grinding nut 30 can be detected and fed back in real time, and the size of the tightening force can be detected in real time by the force sensor 40. Since the size of the tightening force is determined by the size of the friction torque, the larger the friction torque, the larger the nominal diameter of the ball screw 10, the greater the tightening force, and the higher the degree of grinding. Ultimately, the overall diameter change fluctuation of the ball screw 10 is reduced, ensuring the reduction of the friction torque fluctuation over the full stroke of the ball screw 10.

[0040] The third object of the present invention is to provide a method for adjusting the friction torque of a ball screw 10, which is applied to the above-mentioned device for adjusting the friction torque of the ball screw 10, comprising the steps of: A prefabricated ground nut 30 is manufactured according to the ball screw 10; Obtaining the initial friction torque of the ball screw 10; The pressing member 20 drives the prefabricated grinding nut 30 to be set close to the ball screw 10; Obtaining the thrust of the pressing member 20 during the operation of the ball screw 10; The pushing distance of the pressing member 20 is changed according to the magnitude of the thrust, so that the friction torque of the ball screw 10 during the working process is proportional to the initial friction torque.

[0041] According to the specific situation of the ball screw 10, a prefabricated ground nut 30 is manufactured to fit completely with the raceway of the ball screw 10. While the ball screw 10 rotates, the entire outer surface of the ball screw 10 is ground in real time by the prefabricated ground nut 30 to ensure that the friction torque fluctuation of the ball screw 10 is reduced throughout the entire stroke.

[0042] Furthermore, the manufacturing of the prefabricated grinding nut 30 according to the ball screw 10 specifically includes the following steps: Fill the grinding material into the semi-cylindrical mold; The semi-cylindrical mold is fixed on the ball screw 10 to manufacture a prefabricated ground nut 30 that fits the raceway of the ball screw 10 , and the ground nut is installed on the tightening member 20 .

[0043] By filling the grinding raw material into the semi-cylindrical mold and fixing the semi-cylindrical mold on the ball screw 10 to manufacture the prefabricated ground nut 30, it is possible to ensure that the manufactured prefabricated ground nut 30 is completely fitted with the raceway of the ball screw 10. This makes the grinding process more uniform and stable, thereby more accurately adjusting the friction torque of the ball screw 10 and reducing uneven grinding and friction torque fluctuations caused by poor fitting.

[0044] For example, the grinding raw materials include diamond sand and glue. After filling the semi-cylindrical mold, it is tightly fitted with the ball screw 10 and is taken out after solidification to obtain a completely fitted half-piece prefabricated grinding nut 30.

[0045] Specifically, the device is provided with a detection module, which includes: a force sensor 40 and a friction torque detector, the force sensor 40 is used to detect the magnitude of the tightening force of the tightening member 20 on the prefabricated grinding nut 30, and the force sensor 40 and the friction torque detector are arranged on the tightening member 20; changing the push-out distance of the tightening member 20 according to the thrust magnitude so that the friction torque of the ball screw 10 during the working process is proportional to the initial friction torque. Specifically, the steps include: When the friction torque of the ball screw 10 is greater than the initial friction torque, the thrust of the clamping member 20 is increased; When the friction torque of the ball screw 10 is smaller than the initial friction torque, the thrust of the pressing member 20 is reduced.

[0046] The force sensor 40 can accurately detect the tightening force of the tightening member 20 on the prefabricated ground nut 30, and combined with the friction torque detector, it can monitor the change of the friction torque of the ball screw 10 in real time and accurately. Based on these accurate detection data, the friction torque can be adjusted more accurately according to the relationship between the friction torque of the ball screw 10 and the initial friction torque by changing the push-out distance of the tightening member 20, so that it is proportional to the initial friction torque, thereby achieving high-precision control of the friction torque of the ball screw 10.

[0047] 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 device for adjusting the friction torque of a ball screw (10), characterized in that: The device for adjusting the friction torque of the ball screw (10) comprises: Ball screw (10); A prefabricated grinding nut (30), the prefabricated grinding nut (30) being used to grind the ball screw (10), the shape of the prefabricated grinding nut (30) matching the shape of the ball screw (10), the prefabricated grinding nut (30) being closely attached to the raceway of the ball screw (10); A tightening member (20), the tightening member (20) being connected to the prefabricated grinding nut (30) and driving the prefabricated grinding nut (30) to move closer to or farther from the ball screw (10); When the nominal diameter of the ball screw (10) changes during operation, the prefabricated grinding nut (30) grinds the ball screw (10).

2. The device for adjusting the friction torque of a ball screw (10) according to claim 1, characterized in that: The prefabricated grinding nut (30) comprises: A first grinding wall (301) and a second grinding wall (302), wherein the first grinding wall (301) and the second grinding wall (302) are symmetrically arranged on the raceway of the ball screw (10) and are used to grind the ball screw (10).

3. The device for adjusting the friction torque of a ball screw (10) according to claim 2, characterized in that: The prefabricated grinding nut (30) is provided with a nut mounting portion (303), and the pressing member (20) is provided with a nut fixing portion (204), wherein the nut mounting portion (303) cooperates with the nut fixing portion (204) to fix the prefabricated grinding nut (30).

4. The device for adjusting the friction torque of a ball screw (10) according to claim 3, characterized in that: The pressing member (20) comprises: a driving member (202) and a connecting rod (201); the driving member (202) is movably connected to the nut fixing portion (204) via the connecting rod (201); and the driving member (202) drives the prefabricated grinding nut (30) to move closer to or farther from the ball screw (10).

5. A machine tool, characterized in that: include: A device for adjusting the friction torque of a ball screw (10) as claimed in any one of claims 1 to 4.

6. The machine tool according to claim 5, characterized in that: The machine tool comprises: a guide rail, the guide rail is arranged parallel to the ball screw (10), the pressing member (20) is further provided with a sliding groove (203), and the sliding groove (203) is installed on the guide rail; When the device for adjusting the friction torque of the ball screw (10) is in operation, the pressing member (20) slides within the travel of the guide rail through the sliding groove (203).

7. The machine tool according to claim 5, characterized in that: The machine tool further comprises a detection module, the detection module comprising: a force sensor (40), the force sensor (40) being used to detect the magnitude of the tightening force of the tightening member (20) on the prefabricated grinding nut (30), the force sensor (40) being arranged on the tightening member (20).

8. A method for adjusting the friction torque of a ball screw (10), characterized in that: A device for adjusting the friction torque of a ball screw (10) as claimed in any one of claims 1 to 4, comprising the steps of: Manufacturing a prefabricated ground nut (30) according to the ball screw (10); Obtaining the initial friction torque of the ball screw (10); The pressing member (20) drives the prefabricated grinding nut (30) to be arranged close to the ball screw (10); Obtaining the thrust of the pressing member (20) during the operation of the ball screw (10); The pushing distance of the pressing member (20) is changed according to the magnitude of the thrust force, so that the friction torque of the ball screw (10) during operation is proportional to the initial friction torque.

9. The method for adjusting the friction torque of a ball screw (10) according to claim 8, characterized in that: The method of manufacturing a prefabricated grinding nut (30) according to the ball screw (10) specifically comprises the following steps: Fill the grinding material into the semi-cylindrical mold; The semi-cylindrical mold is fixed on the ball screw (10), a prefabricated ground nut (30) that fits the raceway of the ball screw (10) is manufactured, and the ground nut is installed on the tightening member (20).

10. The method for adjusting the friction torque of a ball screw (10) according to claim 8, characterized in that: The device is provided with a detection module, the detection module comprising: a force sensor (40) and a friction torque detector, the force sensor (40) being used to detect the magnitude of the tightening force of the tightening member (20) on the prefabricated grinding nut (30), the force sensor (40) and the friction torque detector being arranged on the tightening member (20); The method of changing the pushing distance of the pressing member (20) according to the thrust force so that the friction torque of the ball screw (10) during operation is proportional to the initial friction torque specifically comprises the following steps: When the friction torque of the ball screw (10) is greater than the initial friction torque, the thrust of the pressing member (20) is increased; When the friction torque of the ball screw (10) is smaller than the initial friction torque, the thrust of the pressing member (20) is reduced.

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