A machine tool error data measuring device and processing method

Abstract

The invention relates to the technical field of machine tool error detection, and discloses a machine tool error data measuring device and a processing method, comprising a magnetic base connected to a workbench of a machine tool; a first standard ball is arranged at one end of a first ballbar, and the first standard ball is connected to the magnetic base; a second standard ball is arranged at one end of a second ballbar, and the second standard ball is connected to an end of the first ballbar away from the magnetic base, and the second ballbar is perpendicular to the first ballbar; a connecting ball is connected to an electric spindle of a machine tool, and the connecting ball is connected to an end of the second ballbar away from the second standard ball, and the electric spindle is coaxial with the second ballbar; an adjusting device comprises a bracket, and the bracket is respectively connected to the first standard ball, the first ballbar and the connecting ball. The invention can obtain more accurate measurement results.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool error detection, and in particular to a machine tool error data measuring device and a processing method. Background Art

[0002] With the continuous development of modern manufacturing industry, the high-end technology field has increasingly higher requirements for the precision of parts processed by CNC machine tools. Effective detection of machine tool geometric errors has become one of the important links to improve machining accuracy. The ballbar has become one of the widely used instruments in the field of CNC machine tool precision detection due to its advantages such as high measurement accuracy, low hardware cost, high measurement efficiency, simple installation and convenient operation.

[0003] During the measurement process, the ballbar moves along the CNC machine tool in a circular arc in clockwise and counterclockwise directions, measures the radius error, and separates the machine tool's verticality, servo mismatch, reverse jump, straightness, scale mismatch and other error terms through data processing and calculation. However, the ballbar can only measure the error change along the length of the rod, and can only analyze the arc trajectory on a single plane, and cannot simultaneously measure the axial error of the servo axis perpendicular to the plane (such as the Z axis). This undesired axial motion of the Z axis will lead to inaccurate ballbar measurement results. Especially when the ballbar is used in the measurement process of industrial robots, the axial motion perpendicular to the measurement plane objectively exists and cannot be effectively avoided, which will lead to inaccurate measurement results. Summary of the invention

[0004] The object of the present invention is to provide a machine tool error data measuring device and processing method, aiming to solve or improve at least one of the above-mentioned technical problems.

[0005] To achieve the above object, the present invention provides the following solution: The present invention provides a machine tool error data measuring device, comprising:

[0006] A magnetic base connected to the workbench of the machine tool;

[0007] A first ballbar, one end of which is provided with a first standard ball, wherein the first standard ball is connected to the magnetic base;

[0008] a second ballbar, one end of which is provided with a second standard ball, the second standard ball is connected to the end of the first ballbar away from the magnetic base, and the second ballbar is perpendicular to the first ballbar;

[0009] a connecting ball connected to an electric spindle of the machine tool, the connecting ball being connected to an end of the second ballbar away from the second standard ball, the electric spindle being coaxial with the second ballbar;

[0010] The adjusting device comprises a bracket, wherein the bracket is respectively connected to the first standard ball, the first ballbar and the connecting ball.

[0011] Optionally, a base cup is threadedly connected to the bracket, and the base cup is connected to the first standard ball.

[0012] Optionally, a positioning adjustment ball is threadedly connected to the bracket, and a positioning frame is provided on the positioning adjustment ball. The positioning frame includes a ring body, and the ring body is sleeved on the first ball bar and connected to the first ball bar by screws. A pair of first cylindrical guide posts and a first cylindrical magnet are provided on the ring body, and the pair of first cylindrical guide posts are used to resist the positioning adjustment ball, and the first cylindrical magnet is used to be magnetically connected to the positioning adjustment ball.

[0013] Optionally, an adjustment frame is threadedly connected to the bracket, and a pair of second cylindrical guide posts and a second cylindrical magnet are provided on the adjustment frame. The pair of second cylindrical guide posts are used to abut against the connecting ball, and the second cylindrical magnet is used to be magnetically connected to the connecting ball.

[0014] Optionally, a first connecting rod is provided on the connecting ball, and the first connecting rod is threadedly connected to the second ballbar.

[0015] Optionally, a second connecting rod is provided on the connecting ball, and the second connecting rod is connected to the electric spindle via a spring clamp.

[0016] Optionally, a connecting socket is provided at one end of the first ballbar away from the first standard ball, and the connecting socket is connected to the second standard ball.

[0017] Optionally, it also includes a calibration plate, which includes a glass base, a pair of support seats are provided at one end of the glass base, and any one of the support seats is provided with a plurality of support balls evenly distributed in the circumference, and the plurality of support balls are used to abut against the first standard ball or the second standard ball or the connecting ball; a pair of third cylindrical guide posts, a third cylindrical magnet and a limiting ball are provided on the other support seat, and the pair of third cylindrical guide posts are used to abut against the first standard ball or the second standard ball or the connecting ball, the third cylindrical magnet is used to be magnetically connected to the first standard ball or the second standard ball or the connecting ball, and the limiting ball is used to abut against the first standard ball or the second standard ball or the connecting ball.

[0018] Optionally, the first standard ball, the second standard ball and the connecting ball are of the same size.

[0019] The present invention also provides a machine tool error data processing method, comprising:

[0020] The first ballbar measurement result is obtained as ;

[0021] The second ballbar measurement result is obtained as ;

[0022] Based on the formula After the Z-axis axial error compensation calculation is completed, the original measurement result of the first ballbar is obtained as follows: ;

[0023] Based on the original measurement result of the first ballbar, , combined with the standard ballbar data processing method, the error calculations of several machine tools are obtained.

[0024] The present invention discloses the following technical effects: by arranging a first ballbar and a second ballbar which are perpendicular to each other, and the second ballbar is arranged coaxially with the electric spindle, and connecting the first standard ball, the first ballbar and the connecting ball as a whole through a bracket, the Z-direction offset of the first ballbar in the XY plane is transferred to the horizontal axial movement of the second ballbar, thereby changing the influence of the unexpected Z-axis axial error on the existing single ballbar measurement result, the unexpected Z-axis axial measurement error is directly reflected by the second ballbar, and the first ballbar which compensates the Z-axis axial error with a formula can obtain a more accurate measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the adjustment device of the present invention;

[0028] Figure 3 It is a schematic diagram of the positioning frame structure of the present invention;

[0029] Figure 4 It is an assembly diagram of the calibration plate and the first ballbar of the present invention;

[0030] Figure 5 It is an assembly diagram of the calibration plate and the second ballbar of the present invention;

[0031] Figure 6 It is a schematic diagram of the calibration plate structure of the present invention.

[0032] In the figure: 1. electric spindle; 2. connecting ball; 3. second ballbar; 4. connecting seat; 5. first ballbar; 6. magnetic seat; 7. workbench; 8. adjustment device; 8-1. base cup; 8-2. bracket; 8-3. adjustment frame; 8-4. positioning adjustment ball; 8-5. positioning frame; 8-51. ring body; 8-52. first cylindrical guide column; 8-53. first cylindrical magnet; 9. calibration plate; 9-1. glass base; 9-2. support ball; 9-3. support seat; 9-4. third cylindrical magnet; 9-5. third cylindrical guide column; 9-6. limit ball. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figure 1-Figure 6 The present invention provides a machine tool error data measuring device, comprising:

[0036] A magnetic base 6 is connected to a working table 7 of a machine tool;

[0037] A first ballbar 5, one end of which is provided with a first standard ball, and the first standard ball is connected to a magnetic base 6;

[0038] A second ballbar 3, one end of which is provided with a second standard ball, the second standard ball is connected to the end of the first ballbar 5 away from the magnetic base 6, and the second ballbar 3 is perpendicular to the first ballbar 5;

[0039] A connecting ball 2 is connected to the electric spindle 1 of the machine tool, the connecting ball 2 is connected to the end of the second ballbar 3 away from the second standard ball, and the electric spindle 1 is coaxial with the second ballbar 3;

[0040] The adjusting device 8 comprises a bracket 8 - 2 , and the bracket 8 - 2 is connected to the first standard ball, the first ballbar and the connecting ball 2 respectively.

[0041] By arranging a first ballbar 5 and a second ballbar 3 which are perpendicular to each other, and the second ballbar 3 being coaxially arranged with the electric spindle 1, and connecting the first standard ball, the first ballbar and the connecting ball 2 as a whole through the bracket 8-2, the Z-direction offset of the first ballbar 5 in the XY plane is transferred to the horizontal axial movement of the second ballbar 3, thereby changing the influence of the unexpected Z-axis axial error on the existing single ballbar measurement result, directly reflecting the unexpected Z-axis axial measurement error through the second ballbar 3, and the first ballbar 5 which compensates the Z-axis axial error through a formula can obtain a more accurate measurement result.

[0042] Furthermore, the total weight of the adjustment device 8 is less than 350 grams.

[0043] Furthermore, the connecting ball 2 is made of Invar steel, has a coaxiality of less than 0.002 mm, a radius of 6.25 mm, and after surface processing, has a dimensional tolerance of ±1 µm, a surface roughness of Ra ≤ 0.05 µm, and a sphericity of ≤ 0.5 µm.

[0044] According to a further optimization scheme, a base cup 8-1 is threadedly connected to the bracket 8-2, and the base cup 8-1 is connected to the first standard ball.

[0045] A further optimized solution is that a positioning adjustment ball 8-4 is threadedly connected to the bracket 8-2, and a positioning frame 8-5 is arranged on the positioning adjustment ball 8-4. The positioning frame 8-5 includes a ring body 8-51, and the ring body 8-51 is sleeved on the first ball bar 5 and connected to the first ball bar 5 by screws. A pair of first cylindrical guide posts 8-52 and a first cylindrical magnet 8-53 are arranged on the ring body 8-51. The pair of first cylindrical guide posts 8-52 are used to abut against the positioning adjustment ball 8-4, and the first cylindrical magnet 8-53 is used to be magnetically connected to the positioning adjustment ball 8-4.

[0046] According to a further optimization scheme, an adjustment frame 8-3 is threadedly connected to the bracket 8-2, and a pair of second cylindrical guide posts and a second cylindrical magnet are provided on the adjustment frame 8-3. The pair of second cylindrical guide posts are used to abut against the connecting ball 2, and the second cylindrical magnet is used to be magnetically connected to the connecting ball 2.

[0047] In a further optimized solution, a first connecting rod is provided on the connecting ball 2, and the first connecting rod is threadedly connected to the second ballbar 3. A second connecting rod is provided on the connecting ball 2, and the second connecting rod is connected to the electric spindle 1 through a spring chuck.

[0048] According to a further optimized solution, a connecting seat 4 is provided at one end of the first ballbar 5 away from the first standard ball, and the connecting seat 4 is connected to the second standard ball.

[0049] A further optimization scheme also includes a calibration plate 9, which includes a glass base 9-1. A pair of support seats 9-3 are arranged at one end of the glass base 9-1, and a plurality of support balls 9-2 uniformly distributed in the circumferential direction are arranged on any support seat 9-3, and the plurality of support balls 9-2 are used to abut against the first standard ball or the second standard ball or the connecting ball 2; a pair of third cylindrical guide posts 9-5, a third cylindrical magnet 9-4 and a limiting ball 9-6 are arranged on the other support seat 9-3, a pair of third cylindrical guide posts 9-5 are used to abut against the first standard ball or the second standard ball or the connecting ball 2, the third cylindrical magnet 9-4 is used to magnetically connect with the first standard ball or the second standard ball or the connecting ball 2, and the limiting ball 9-6 is used to abut against the first standard ball or the second standard ball or the connecting ball 2.

[0050] Calibration method of the first ballbar 5 and the second ballbar 3:

[0051] Place the second ballbar 3 on the calibration plate 9, the second standard ball at one end of the second ballbar 3 contacts the third cylindrical guide post 9-5 and the limit ball 9-6 on the calibration plate 9, the connecting ball 2 contacts the three supporting balls 9-2 on the calibration plate 9, and after the readings are stable, record the calibration value;

[0052] The second ballbar 3 and the first ballbar 5 are connected and then mounted on the calibration plate 9, the first standard ball at one end of the first ballbar 5 contacts the three support balls 9-2 on the calibration plate 9, and contacts the second standard ball connected to the connection seat 4 and the second ballbar 3, and the third cylindrical guide post 9-5 and the limit ball 9-6 on the calibration plate 9, respectively. The two first standard balls and the second standard balls constitute the two ends of the first ballbar 5, and the center distance between them represents the calibration radius of the first ballbar 5;

[0053] According to the standard size, the relationship between the readings of the first ballbar 5 and the second ballbar 3 and the standard size is calculated respectively, and the formula is used as the subsequent ballbar on-machine measurement reading conversion.

[0054] According to a further optimization scheme, the first standard ball, the second standard ball and the connecting ball 2 have the same size and a radius of 6.25 mm.

[0055] Installation steps:

[0056] Install the positioning frame 8-5 on the first ballbar 5 to complete the rough positioning;

[0057] Install the second ballbar 3 and the magnetic base 6 on the electric spindle 1 and the workbench 7 respectively, run the test machine tool equipment, connect the magnetic base 6 and the second standard ball at one end of the second ballbar 3 through magnetic force, and record the spatial coordinate position of the workbench 7;

[0058] Adjust the spatial position of the workbench 7 so that the spatial distance between it and the axis of the electric spindle 1 is the nominal measurement radius, and then install the first ballbar 5 so that it is connected to the second ballbar 3 and the magnetic base 6 respectively;

[0059] Install the adjustment device 8, connect the first standard ball of the first ballbar 5 and the connecting ball 2 respectively, and accurately adjust the positioning frame 8-5 installed for rough positioning so that it is in precise contact with the positioning adjustment ball 8-4;

[0060] The CNC machine tool is operated to make the worktable 7 perform a circular rotation motion with a radius equal to the nominal measurement radius around the axis of the electric spindle 1 according to the measurement rules; the ballbar instrument data recorder is started to complete the data collection of the first ballbar 5 and the second ballbar 3.

[0061] A machine tool error data processing method, comprising:

[0062] The first ballbar measurement result is obtained as , which represents the radius result rich in unexpected Z-axis axial error values;

[0063] The measurement result of the second ballbar 3 is obtained as , which directly reflects the unexpected Z-axis axial measurement error;

[0064] Based on the formula After the Z-axis axial error compensation calculation is completed, the original measurement result of the first ballbar 5 is obtained as follows: ;

[0065] Based on the original measurement result of the first ballbar 5: , combined with the standard ballbar data processing method, the precise center of rotation is found after least squares fitting, and the accurate radius error is calculated. According to the ISO230-4:2022 national standard, the error items of several machine tools are calculated.

[0066] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0067] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A machine tool error data measuring device, characterized in that: include: A magnetic base (6) connected to a workbench (7) of a machine tool; A first ballbar (5) having a first standard ball disposed at one end, wherein the first standard ball is connected to the magnetic base (6); a second ballbar (3), one end of which is provided with a second standard ball, the second standard ball being connected to an end of the first ballbar (5) away from the magnetic base (6), the second ballbar (3) being perpendicular to the first ballbar (5); A connecting ball (2) connected to the electric spindle (1) of the machine tool, the connecting ball (2) connected to the end of the second ballbar (3) away from the second standard ball, the electric spindle (1) and the second ballbar (3) being coaxial; An adjustment device (8) comprises a bracket (8-2), wherein the bracket (8-2) is respectively connected to the first standard ball, the first ballbar and the connecting ball (2); The calibration plate (9) further comprises a calibration plate (9), wherein the calibration plate (9) comprises a glass base (9-1), wherein one end of the glass base (9-1) is provided with a pair of support seats (9-3), wherein any one of the support seats (9-3) is provided with a plurality of support balls (9-2) evenly distributed in the circumferential direction, wherein the plurality of support balls (9-2) are used to abut against the first standard ball or the second standard ball or the connecting ball (2); and the other support seat (9-3) is provided with a pair of third cylindrical guide posts (9-5), a third cylindrical magnet (9-4) and a limiting ball (9-6), wherein the pair of third cylindrical guide posts (9-5) are used to abut against the first standard ball or the second standard ball or the connecting ball (2), wherein the third cylindrical magnet (9-4) is used to be magnetically connected to the first standard ball or the second standard ball or the connecting ball (2), and wherein the limiting ball (9-6) is used to abut against the first standard ball or the second standard ball or the connecting ball (2).

2. A machine tool error data measuring device according to claim 1, characterized in that: A base cup (8-1) is threadedly connected to the bracket (8-2), and the base cup (8-1) is connected to the first standard ball.

3. The machine tool error data measuring device according to claim 1, characterized in that: A positioning adjustment ball (8-4) is threadedly connected to the bracket (8-2); a positioning frame (8-5) is arranged on the positioning adjustment ball (8-4); the positioning frame (8-5) comprises a ring body (8-51); the ring body (8-51) is sleeved on the first ball bar (5) and connected to the first ball bar (5) via screws; a pair of first cylindrical guide posts (8-52) and a first cylindrical magnet (8-53) are arranged on the ring body (8-51); the pair of first cylindrical guide posts (8-52) are used to abut against the positioning adjustment ball (8-4); and the first cylindrical magnet (8-53) is used to be magnetically connected to the positioning adjustment ball (8-4).

4. The machine tool error data measuring device according to claim 1, characterized in that: An adjustment frame (8-3) is threadedly connected to the bracket (8-2), and a pair of second cylindrical guide pillars and a second cylindrical magnet are provided on the adjustment frame (8-3); the pair of second cylindrical guide pillars are used to abut against the connecting ball (2), and the second cylindrical magnet is used to be magnetically connected to the connecting ball (2).

5. The machine tool error data measuring device according to claim 1, characterized in that: The connecting ball (2) is provided with a first connecting rod, and the first connecting rod is threadedly connected to the second ballbar (3).

6. The machine tool error data measuring device according to claim 1, characterized in that: A second connecting rod is provided on the connecting ball (2), and the second connecting rod is connected to the electric spindle (1) via a spring clamp.

7. The machine tool error data measuring device according to claim 1, characterized in that: A connecting seat (4) is provided at one end of the first ballbar (5) away from the first standard ball, and the connecting seat (4) is connected to the second standard ball.

8. The machine tool error data measuring device according to claim 1, characterized in that: The first standard ball, the second standard ball and the connecting ball (2) have the same size.

9. A method for processing machine tool error data, based on a machine tool error data measuring device according to any one of claims 1 to 8, characterized in that: include: The measurement result of the first ballbar (5) is obtained as follows: ; The measurement result of the second ballbar (3) is obtained as follows: ; Based on the formula After the Z-axis axial error compensation calculation is completed, the original measurement result of the first ballbar (5) is obtained as follows: ; Based on the original measurement result of the first ballbar (5), , combined with the standard ballbar data processing method, the error calculations of several machine tools are obtained.

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