Testing device for precision retentivity of feeding unit of numerical control grinding machine

Abstract

The invention discloses a numerical control grinding machine feeding unit precision retentivity test device which comprises a base lathe bed, a pair of stand columns are symmetrically and fixedly connected to the two sides of the top of the base lathe bed, the tops of the pair of stand columns are jointly and fixedly connected with an upper transverse frame, a cross beam is fixedly connected to the position, located below the upper transverse frame, between the pair of stand columns, and a movable supporting plate is installed at the front end of the cross beam. A middle cross beam is fixedly connected to the positions, corresponding to the cross beam, of the front ends of the pair of stand columns, and the test device further comprises a Z-direction loading assembly, a Y-direction loading assembly, an X-direction loading assembly and a motion supporting plate position adjusting assembly, and the stroke error of the ball screw is measured through a linear grating ruler and a high-precision angle encoder in the test device. The laser interferometer is used for measuring the straightness error of the workbench in the movement direction, the actual working condition of the linear feeding unit is simulated to carry out an accelerated degradation test, and the influence of the ball screw pair and the linear guide rail on the precision retentivity after abrasion is measured.

Description

Technical Field

[0001] The invention relates to the technical field of industrial machine tool precision retention research, and in particular to a CNC grinding machine feed unit precision retention test device. Background Art

[0002] The combined feed unit of a CNC grinding machine primarily consists of a linear guideway and a ball screw. These two components are crucial components in modern industrial and medical equipment, and their accuracy is one of the most significant factors affecting the positioning accuracy of the entire system. During the operation of a ball screw, wear on the screw and nut raceways can cause changes in raceway geometry. During the operation of a linear guide, wear on the slider and guideway raceways can cause changes in guideway straightness, directly impacting the transmission system's accuracy retention.

[0003] A search revealed that Chinese Patent Publication No. CN201711028873.3 proposes a wear pattern test device for a combined linear feed unit of a machine tool. Chinese Patent Publication No. CN201810221385.2 also proposes a corresponding test method based on this device. Similar test methods study wear by measuring parameters such as the positioning accuracy and straightness of the bed's linear feed unit. However, few studies have examined the wear patterns of the lead screw and guide rails mounted on the crossbeam. Because the crossbeam of a gantry machine tool is heavy and bears the weight of its upper slide and spindle box, it deforms significantly. The lead screw and guide rails mounted on the crossbeam also deform accordingly, causing changes in the contact deformation and wear of the lead screw and guide rail pairs. Therefore, the applicant designed a test device for the accuracy retention of a CNC grinding machine feed unit to study the accuracy degradation patterns of a combined linear feed unit of a gantry-type grinding machine, taking into account crossbeam deformation. The test device was designed to simulate actual operating conditions for testing, making the tests more meaningful and accurate. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present application provides a CNC grinding machine feed unit precision retention test device, which uses a linear grating scale and a high-precision angle encoder in the test device to measure the stroke error of the ball screw, and uses a laser interferometer to measure the straightness error of the worktable along the direction of motion. The actual working conditions of the linear feed unit are simulated to carry out accelerated degradation tests, and the impact of wear on the precision retention of the ball screw pair and linear guide rail is measured.

[0005] To achieve the above-mentioned objectives, the present application provides the following technical solution: a CNC grinding machine feed unit precision retention test device, comprising: a base bed, a pair of columns symmetrically fixedly connected to the top of the base bed on both sides, an upper cross frame fixedly connected to the tops of the pair of columns, a crossbeam fixedly connected between the pair of columns and below the upper cross frame, a moving support plate installed at the front end of the crossbeam, and a middle crossbeam fixedly connected to the front ends of the pair of columns at positions corresponding to the crossbeam;

[0006] It also includes a Z-direction loading assembly, which is installed on the upper cross frame and is used to apply a Z-direction load to the moving pallet;

[0007] Y-direction loading assembly, which is installed on the middle crossbeam and is used to apply Y-direction load to the moving pallet;

[0008] X-direction loading assembly, which is installed on the moving pallet and is used to apply X-direction load to the moving pallet;

[0009] The moving pallet position adjustment component is installed on the moving pallet and is used to adjust the X-axis position of the moving pallet.

[0010] Preferably, the Z-direction loading assembly includes a mounting frame fixedly connected to the bottom of the upper cross frame, and a Z-direction loading cylinder body is fixedly mounted on the mounting frame, and a pair of Z-direction loading cylinder bodies are provided.

[0011] Preferably, the Y-direction loading assembly includes a Y-direction loading cylinder body fixedly mounted on the middle crossbeam, and a pair of Y-direction loading cylinder bodies are provided.

[0012] Preferably, the X-direction loading assembly includes a force support plate installed at the front end of the beam, on which an X-axis force cylinder body is fixedly installed. The X-direction loading assembly also includes an X-axis AC servo motor fixedly installed at the front end of the beam and an X-axis ball screw pair laterally arranged at the front end of the beam. One end of the X-axis ball screw pair is fixedly connected to the output end of the X-axis AC servo motor through a coupling, and the other end of the X-axis ball screw pair is rotatably connected to a bearing bracket through a bearing. The bearing bracket is fixedly connected to the beam, and the force support plate and the X-axis ball screw pair are connected through a ball nut structure.

[0013] Preferably, the output end of the Z-direction loading cylinder body faces the moving pallet and is rotatably connected to the Z-direction roller, the output end of the Y-direction loading cylinder body faces the moving pallet and is rotatably connected to the Y-direction roller, and the output end of the X-axis force cylinder body faces the moving pallet and is rotatably connected to the X-axis roller, and the Z-direction roller, Y-direction roller and X-axis roller are in contact with the moving pallet.

[0014] Preferably, the moving support plate position adjustment assembly includes an axially loaded AC servo motor fixedly mounted on the front end of the beam and a U-axis drive screw pair laterally arranged at the front end of the beam. The U-axis drive screw pair is arranged parallel to the X-axis ball screw pair. One end of the U-axis drive screw pair is fixedly connected to the output end of the axially loaded AC servo motor through a coupling. The other end of the U-axis drive screw pair is rotatably connected to a bearing bracket through a bearing. The bearing bracket is fixedly connected to the beam. The moving support plate and the U-axis drive screw pair are connected through a ball nut structure.

[0015] Preferably, a pair of linear guide rails are fixedly connected to the front end of the beam, the linear guide rails are arranged parallel to the U-axis driving screw pair, and the force support plate and the motion support plate are slidably connected to the linear guide rails.

[0016] Preferably, it also includes a laser interferometer, which consists of a frequency-stabilized laser and an interferometer 6D sensor. The frequency-stabilized laser is fixedly mounted on the beam, and the interferometer 6D sensor is fixedly mounted on the moving support plate, and the positions of the frequency-stabilized laser and the interferometer 6D sensor correspond to each other.

[0017] Preferably, a linear grating ruler is installed between the moving support plate and the linear guide rail.

[0018] Preferably, a high-precision angle encoder is installed on one end of the U-axis driving screw pair and the X-axis ball screw pair.

[0019] The beneficial effects of the present invention are:

[0020] During the test process, the present invention uses a linear grating ruler and a high-precision angle encoder in the test device to measure the stroke error of the ball screw. At the same time, a laser interferometer is used to measure the straightness error of the workbench along the movement direction and the deflection angles in the X / Y / Z directions. The test uses a cylinder to apply loads on the X-axis, Y-axis and Z-axis to the workbench, simulating the actual working conditions of the linear feed unit to perform an accelerated degradation test, measuring the impact of the ball screw pair and linear guide rail on the accuracy retention after wear. Through the parameter changes monitored by various sensors on the test device, the accuracy degradation and wear rules of the test device are mathematically modeled and analyzed, and the accuracy retention of the linear feed unit is further studied. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the CNC grinding machine feed unit accuracy retention test device;

[0022] Figure 2 Schematic diagram of the upper cross frame and Z-direction loading assembly structure;

[0023] Figure 3 Schematic diagram of the structure of the middle beam and Y-direction loading components;

[0024] Figure 4 It is a schematic diagram of the structure of the crossbeam, moving pallet position adjustment component and X-axis loading component.

[0025] In the figure: 1. Base bed; 2. Column; 3. Middle crossbeam; 4. Upper cross frame; 5. Crossbeam; 6. Mounting frame; 7. Z-axis loading cylinder body; 8. Z-axis roller; 9. Y-axis loading cylinder body; 10. Y-axis roller; 11. Force support plate; 12. X-axis force cylinder body; 13. X-axis roller; 14. Motion support plate; 15. Linear guide; 16. X-axis ball screw pair; 17. U-axis drive screw pair; 18. X-axis AC servo motor; 19. Axial loading AC servo motor; 20. Bearing bracket; 21. Bearing. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Example

[0028] like Figures 1 to 4 As shown, a CNC grinding machine feed unit precision retention test device includes: a base bed 1, a pair of columns 2 are symmetrically fixedly connected to the top of the base bed 1 on both sides, the tops of the pair of columns 2 are commonly fixedly connected to an upper cross frame 4, a crossbeam 5 is fixedly connected between the pair of columns 2 and below the upper cross frame 4, a moving pallet 14 is installed at the front end of the crossbeam 5, and a middle crossbeam 3 is fixedly connected at the front end of the pair of columns 2 corresponding to the position of the crossbeam 5; it also includes a Z-direction loading component, a Y-direction loading component, an X-direction loading component and a moving pallet position adjustment component, the Z-direction loading component is installed on the upper cross frame 4, and is used to apply a Z-direction load to the moving pallet 14, the Y-direction loading component is installed on the middle crossbeam 3, and is used to apply a Y-direction load to the moving pallet 14, the X-direction loading component is installed on the moving pallet 14, and is used to apply an X-direction load to the moving pallet 14, and the moving pallet position adjustment component is installed The moving pallet 14 is used to adjust the X-direction position of the moving pallet 14. The moving pallet 14 is used to simulate the crossbeam of a gantry grinder. The Z-direction load is applied to the moving pallet 14 through the Z-direction loading component to simulate the gravity of the slide, spindle box and grinding wheel on the crossbeam of the gantry grinder, so that the crossbeam undergoes slight deformation. The Y-direction loading component applies the Y-direction load to the moving pallet 14, and the X-direction loading component applies the X-direction load to the moving pallet 14 to simulate the actual working conditions. It is used to simulate the loading forces in different directions on the crossbeam of the gantry grinder. The moving pallet position adjustment component is used to adjust the X-direction position of the moving pallet 14, so as to facilitate the adjustment of the force application position of the moving pallet 14, thereby realizing the simulation of the actual movement process of the linear feed unit on the crossbeam of the gantry machine tool, so as to facilitate the precision retention test of the feed unit of the CNC grinder, which is simple to operate and easy to use.

[0029] In this embodiment, if Figure 1 and Figure 2 As shown, the Z-direction loading assembly includes a mounting frame 6 fixedly connected to the bottom of the upper cross frame 4, and a Z-direction loading cylinder body 7 is fixedly installed on the mounting frame 6. The Z-direction loading cylinder body 7 is provided with a pair of output ends of the Z-direction loading cylinder bodies 7 facing the moving support plate 14, for applying a Z-direction load to the moving support plate 14.

[0030] In this embodiment, if Figure 1 and Figure 3 As shown, the Y-direction loading assembly includes a Y-direction loading cylinder body 9 fixedly mounted on the middle cross beam 3 , and a pair of Y-direction loading cylinder bodies 9 are provided, through the output end of the Y-direction loading cylinder body 9 toward the moving support plate 14 , for applying a Y-direction load to the moving support plate 14 .

[0031] In this embodiment, if Figure 1 and Figure 4 As shown, the X-direction loading assembly includes a force support plate 11 installed at the front end of the beam 5, and an X-axial force cylinder body 12 is fixedly installed on the force support plate 11, which is used to apply an X-direction load to the moving support plate 14 through the output end of the X-axial force cylinder body 12 toward the moving support plate 14.

[0032] In this embodiment, if Figure 1 and Figure 4 As shown, the motion support plate position adjustment assembly includes an axially loaded AC servo motor 19 fixedly mounted on the front end of the beam 5 and a U-axis driven screw pair 17 transversely arranged on the front end of the beam 5. One end of the U-axis driven screw pair 17 is fixedly connected to the output end of the axially loaded AC servo motor 19 through a coupling. The other end of the U-axis driven screw pair 17 is rotatably connected to a bearing bracket 20 through a bearing 21. The bearing bracket 20 is fixedly connected to the beam 5 and supports one end of the U-axis driven screw pair 17 through the bearing 21 and the bearing bracket 20. To improve the installation stability of the U-axis drive screw pair 17, the moving support plate 14 is connected to the U-axis drive screw pair 17 through a ball nut structure, and the U-axis drive screw pair 17 is driven to rotate by the axially loaded AC servo motor 19, thereby driving the moving support plate 14 to move axially along the U-axis drive screw pair 17, which is used to adjust the position of the moving support plate 14 so that the Z-direction loading cylinder body 7 and the Y-direction loading cylinder body 9 can apply loads to different positions of the moving support plate 14, which is helpful for collecting diverse test results and ensuring experimental accuracy.

[0033] In this embodiment, if Figure 4As shown, the X-axis loading assembly also includes an X-axis AC servo motor 18 fixedly mounted on the front end of the beam 5 and an X-axis ball screw pair 16 laterally arranged at the front end of the beam 5. The U-axis driving screw pair 17 is arranged in parallel with the X-axis ball screw pair 16. One end of the X-axis ball screw pair 16 is fixedly connected to the output end of the X-axis AC servo motor 18 through a coupling. The other end of the X-axis ball screw pair 16 is rotatably connected to a bearing bracket 20 through a bearing 21. The bearing bracket 20 is fixedly connected to the beam 5. The force support plate 11 is connected to the X-axis ball screw pair 16. The ball screw pairs 16 are connected by a ball nut structure. The moving support plate 14 is provided with an avoidance position for the X-axis ball screw pair 16 to pass through, and the force support plate 11 is provided with an avoidance position for the U-axis drive screw pair 17 to pass through. The X-axis AC servo motor 18 drives the X-axis ball screw pair 16 to rotate, thereby driving the force support plate 11 to move axially along the X-axis ball screw pair 16, so that the force support plate 11 can adapt to the position adjustment movement of the moving support plate 14, thereby maintaining the X-direction load applied to the moving support plate 14.

[0034] In this embodiment, if Figure 4 As shown, a pair of linear guide rails 15 are fixedly connected to the front end of the beam 5, and the linear guide rails 15 are arranged parallel to the U-axis driving screw pair 17. The force support plate 11 and the moving support plate 14 are slidingly connected to the linear guide rails 15. Through the set linear guide rails 15, when the moving support plate 14 and the force support plate 11 move and adjust their positions, the moving support plate 14 and the force support plate 11 are provided with a limiting and guiding function, thereby improving the stability and smoothness of the position adjustment of the moving support plate 14 and the force support plate 11.

[0035] In this embodiment, if Figure 2 、 Figure 3 and Figure 4 As shown, the output end of the Z-direction loading cylinder body 7 faces the moving pallet 14 and is rotatably connected to the Z-direction roller 8, the output end of the Y-direction loading cylinder body 9 faces the moving pallet 14 and is rotatably connected to the Y-direction roller 10, and the output end of the X-axis force cylinder body 12 faces the moving pallet 14 and is rotatably connected to the X-axis roller 13. The Z-direction roller 8, the Y-direction roller 10 and the X-axis roller 13 are in contact with the moving pallet 14. By connecting rollers to the output ends of the Z-direction loading cylinder body 7, the Y-direction loading cylinder body 9 and the X-axis force cylinder body 12, the friction force between them and the moving pallet 14 is reduced, which helps the position movement operation of the moving pallet 14.

[0036] An embodiment of the present invention provides a CNC grinding machine feed unit precision retention test device, which also includes a laser interferometer. The laser interferometer consists of a frequency-stabilized laser and an interferometer 6D sensor. The frequency-stabilized laser is fixedly mounted on the crossbeam 5, and the interferometer 6D sensor is fixedly mounted on the moving support plate 14. The frequency-stabilized laser and the interferometer 6D sensor correspond in position to each other. Setting up the laser interferometer can measure changes in the accuracy of the test device. The roll, yaw, and pitch angles and displacements of the moving carriage 14 are measured through the laser interferometer monitoring system. The laser interferometer is used to measure the straightness error of the moving carriage 14 along the direction of motion and the deflection angles in the X / Y / Z directions. The frequency-stabilized laser of the laser interferometer is fixed on the crossbeam 5, and the interferometer 6D sensor is fixed on the moving support plate 14 and reciprocates therewith. Since the degradation process of the test is relatively slow, the test is required for a certain period of time, and measurements are performed regularly. The measurement interval is preliminarily determined to be 1000 reciprocating cycles of the workbench, that is, data is collected once when the workbench completes 1000 reciprocating cycles, and online measurement is performed.

[0037] In this embodiment, a linear scale is installed between the moving pallet 14 and the linear guide 15, and high-precision angle encoders are installed at one end of the U-axis drive screw pair 17 and the X-axis ball screw pair 16. The linear scale and high-precision angle encoder in the test device are used to measure the stroke error of the U-axis drive screw pair 17 and the X-axis ball screw pair 16, and the gap between the moving pallet 14 and the U-axis drive screw pair 17 and the X-axis ball screw pair 16 is measured. Before the moving pallet 14 moves, the position of the moving pallet 14 is set to zero using the linear scale, and the position of the ball screw pair is set to zero through the encoder. When the movement is completed, the length value of the linear scale is read, and then the angle of rotation of the ball screw pair is read through the encoder. The value read by the encoder is converted into linear displacement, and then compared with the value obtained by the linear scale to obtain the positioning accuracy of the ball screw pair. The principle is shown in the following formula.

[0038]

[0039] Where Z is the distance the worktable moves, θ is the angle the screw shaft rotates, and l is the lead of the screw shaft.

[0040] The control method of the present invention is controlled by the controller of the test device. The control program of the controller can be implemented by simple programming by technicians in this field, so the present invention does not explain the control method and circuit connection in detail. Among them, the test device adopts a large flow relief valve with a pressure regulating valve to achieve high loading force, and controls the extension and contraction action of the cylinder and the action of the servo motor to coordinate and complete the loading test, which can realize one-way loading, reciprocating loading, unidirectional loading and multi-directional loading and other methods to simulate the working conditions.

[0041] Implementation plan: The test bench is run in without load: the linear guide 15, X-axis ball screw pair 16, and U-axis drive screw pair 17 on the test bench crossbeam 5 are lubricated, the X-axis AC servo motor 18 and the axial loading AC servo motor 19 are started, and the test device is run under no-load conditions, while ensuring that the running speed of the test device can be adjusted by the controller; to ensure normal operation of the test device and accurate data collection, the running speed of the X-axis AC servo motor 18 and the axial loading AC servo motor 19 is set to 2000r / min, and 100-300 reciprocating runs are performed according to the ambient temperature to fully warm up;

[0042] Carry out acceleration test: the Z-direction loading cylinder body 7 on the upper cross frame 4 is extended, and a Z-direction heavy load is continuously applied to the moving carriage 14 to simulate the gravity of the slide and the spindle box on the machine tool beam. During operation, the extension and contraction of each force cylinder can simulate the actual working conditions by unidirectional loading and multi-directional loading. The moving carriage 14 is driven by the U-axis screw pair 17 and the axial loading AC servo motor 19 to reciprocate. The drag carriage 11 realizes synchronous reciprocating motion through the X-axis ball screw pair 16 and the X-axis AC servo motor 18. When the Y-direction loading cylinder body 9 is extended, a Y-direction load is applied to the moving carriage 14. When the X-axis force cylinder body 12 is extended, an X-direction load is applied to the moving carriage 14. The size and direction of the load on the moving carriage 14 are changed by changing the extension length of the cylinder body through the controller of the test device.

[0043] Laser interferometer measurement: Setting up a laser interferometer can measure the change in the accuracy of the test device. The roll, yaw, and pitch angles and displacements of the moving carriage 14 are measured through the laser interferometer monitoring system. The laser interferometer is used to measure the straightness error of the moving carriage 14 along the direction of motion, as well as the deflection angles in the X / Y / Z directions. The laser interferometer's stabilized laser is fixed on the crossbeam 5, and the interferometer 6D sensor is fixed on the moving carriage 14 and reciprocates with it. Since the degradation process of the test is relatively slow, the test must be carried out for a certain period of time, and measurements must be performed regularly. The measurement interval is preliminarily determined to be 1000 reciprocating cycles of the workbench, that is, data is collected once when the workbench completes 1000 reciprocating cycles, and online measurement is performed;

[0044] Measure the gap between the moving carriage 14 and the U-axis drive screw pair 17 and the X-axis ball screw pair 16: Before the moving carriage 14 moves, use a linear scale to set the position of the moving carriage 14 to zero, and set the position of the ball screw pair to zero using an encoder. After the movement is completed, read the length value of the linear scale, and then read the angle of rotation of the ball screw pair using the encoder. The value read by the encoder is converted into a linear displacement, and then compared with the value obtained by the linear scale to obtain the positioning accuracy of the ball screw pair;

[0045] During the test process, the present invention uses a linear grating ruler and a high-precision angle encoder in the test device to measure the stroke error of the ball screw. At the same time, a laser interferometer is used to measure the straightness error of the workbench along the movement direction and the deflection angles in the X / Y / Z directions. The test uses a cylinder to apply loads on the X-axis, Y-axis and Z-axis to the workbench, simulating the actual working conditions of the linear feed unit to perform an accelerated degradation test, measuring the impact of the ball screw pair and linear guide rail on the accuracy retention after wear. Through the parameter changes monitored by various sensors on the test device, the accuracy degradation and wear rules of the test device are mathematically modeled and analyzed, and the accuracy retention of the linear feed unit is further studied.

[0046] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A CNC grinding machine feed unit precision retention test device, characterized in that: include: The base bed has a pair of columns symmetrically fixedly connected on both sides of the top of the base bed, the tops of the pair of columns are fixedly connected to an upper cross frame, a cross beam is fixedly connected between the pair of columns and below the upper cross frame, a moving support plate is installed at the front end of the cross beam, and a middle cross beam is fixedly connected at the front end of the pair of columns corresponding to the position of the cross beam; It also includes a Z-direction loading assembly, which is installed on the upper cross frame and is used to apply a Z-direction load to the moving pallet; Y-direction loading assembly, which is installed on the middle crossbeam and is used to apply Y-direction load to the moving pallet; X-direction loading assembly, which is installed on the moving pallet and is used to apply X-direction load to the moving pallet; The moving pallet position adjustment component is installed on the moving pallet and is used to adjust the X-axis position of the moving pallet.

2. A CNC grinding machine feed unit precision retention test device according to claim 1, characterized in that: The Z-direction loading assembly comprises a mounting frame fixedly connected to the bottom of the upper cross frame, a Z-direction loading oil cylinder body is fixedly mounted on the mounting frame, and a pair of Z-direction loading oil cylinder bodies are provided.

3. A CNC grinding machine feed unit precision retention test device according to claim 2, characterized in that: The Y-direction loading assembly comprises a Y-direction loading oil cylinder body fixedly mounted on the middle cross beam, and a pair of Y-direction loading oil cylinder bodies is provided.

4. A CNC grinding machine feed unit precision retention test device according to claim 3, characterized in that: The X-direction loading assembly includes a force supporting plate installed at the front end of the crossbeam, on which an X-axis force cylinder body is fixedly installed. The X-direction loading assembly also includes an X-axis AC servo motor fixedly installed at the front end of the crossbeam and an X-axis ball screw pair arranged horizontally at the front end of the crossbeam. One end of the X-axis ball screw pair is fixedly connected to the output end of the X-axis AC servo motor through a coupling, and the other end of the X-axis ball screw pair is rotatably connected to a bearing bracket through a bearing. The bearing bracket is fixedly connected to the crossbeam, and the force supporting plate and the X-axis ball screw pair are connected by a ball nut structure.

5. The CNC grinding machine feed unit precision retention test device according to claim 4, characterized in that: The output end of the Z-direction loading cylinder body faces the moving pallet and is rotatably connected to the Z-direction roller. The output end of the Y-direction loading cylinder body faces the moving pallet and is rotatably connected to the Y-direction roller. The output end of the X-axis force cylinder body faces the moving pallet and is rotatably connected to the X-axis roller. The Z-direction roller, Y-direction roller and X-axis roller are in contact with the moving pallet.

6. A CNC grinding machine feed unit precision retention test device according to claim 4, characterized in that: The motion support plate position adjustment component includes an axially loaded AC servo motor fixedly mounted on the front end of the beam and a U-axis drive screw pair laterally arranged at the front end of the beam. The U-axis drive screw pair is arranged in parallel with the X-axis ball screw pair. One end of the U-axis drive screw pair is fixedly connected to the output end of the axially loaded AC servo motor through a coupling. The other end of the U-axis drive screw pair is rotatably connected to a bearing bracket through a bearing. The bearing bracket is fixedly connected to the beam. The motion support plate and the U-axis drive screw pair are connected through a ball nut structure.

7. A CNC grinding machine feed unit precision retention test device according to claim 6, characterized in that: A pair of linear guide rails are fixedly connected to the front end of the beam. The linear guide rails are arranged parallel to the U-axis driving screw pair, and the force support plate and the motion support plate are slidably connected to the linear guide rails.

8. The CNC grinding machine feed unit precision retention test device according to claim 1, characterized in that: It also includes a laser interferometer, which consists of a frequency-stabilized laser and an interferometer 6D sensor. The frequency-stabilized laser is fixedly mounted on the crossbeam, and the interferometer 6D sensor is fixedly mounted on the moving support plate, and the positions of the frequency-stabilized laser and the interferometer 6D sensor correspond to each other.

9. The CNC grinding machine feed unit precision retention test device according to claim 7, characterized in that: A linear grating ruler is installed between the moving pallet and the linear guide rail.

10. The CNC grinding machine feed unit precision retention test device according to claim 6, characterized in that: A high-precision angle encoder is installed on one end of the U-axis drive screw pair and the X-axis ball screw pair.

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