A measuring system and centering method for annular workpiece

Abstract

The present invention belongs to the field of high-precision measurement technology, and particularly refers to a measurement system and centering method for an annular workpiece. The measurement system includes an XY positioning platform, a rotating table, an XY manual adjustment table, and a distance sensor. The XY positioning platform is used for moving and positioning the annular workpiece in the X and Y directions; the rotating table is arranged on the XY positioning platform for rotating the annular workpiece; the XY manual adjustment table is arranged on the rotating table for fine-tuning the X and Y direction positions of the annular workpiece; the distance sensor is used to measure the distance from the distance sensor to the inner or outer wall of the annular workpiece. The distance sensor of the present invention is used to detect the distance to the inner and outer walls of the annular workpiece. The offset of the center of the annular workpiece can be calculated through the position of the minimum measurement value, and then the offset in the XY direction can be eliminated respectively through the XY manual adjustment table, so as to realize the precise centering of the annular workpiece. The measurement system and centering method of the present invention have the characteristics of convenient operation and high detection accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of high-precision measurement, and in particular relates to a measuring system and a centering method for an annular workpiece. Background Art

[0002] Annular thin-walled workpieces are indispensable components in national defense, aviation, information electronics, and optical systems. The cylindricity, surface error, and topography error of annular thin-walled workpieces greatly affect the performance of the system. Accurately and stably measuring the wall surface of annular thin-walled workpieces, thereby improving the machining accuracy of annular thin-walled workpieces, is an important and effective means to improve system performance.

[0003] In the measurement system of annular thin-walled workpieces, the centering error of the annular thin-walled workpiece and the centering error of the sensor are important sources of error. The centering error of the annular thin-walled workpiece and the centering error of the sensor directly lead to the measurement error of the annular thin-walled workpiece. This error is more significant and critical in the precision measurement system. Effectively suppressing and decomposing the centering error of the annular thin-walled workpiece and the centering error of the sensor is of greater significance for the precision measurement of annular thin-walled workpieces.

[0004] However, due to the processing and assembly errors of the measurement system, it is difficult to ensure the centering accuracy of the annular thin-walled workpiece and the centering accuracy of the sensor. Therefore, it is very necessary to develop an inner and outer wall measurement system and centering method for annular thin-walled workpieces to improve the measurement accuracy of annular thin-walled workpieces. Summary of the invention

[0005] The purpose of the present invention is to provide a measuring system and a centering method for an annular workpiece with simple structure, convenient operation and high measuring accuracy.

[0006] The object of the present invention is achieved in that:

[0007] A measuring system for an annular workpiece, comprising:

[0008] XY positioning platform, used for the movement and positioning of the annular workpiece in the X and Y directions;

[0009] A rotating table, arranged on the XY positioning platform, is used for rotating the annular workpiece;

[0010] An XY manual adjustment table is arranged on the rotating table, and a workpiece mounting position for clamping an annular workpiece is arranged on the XY manual adjustment table; the XY manual adjustment table is used to fine-tune the position of the annular workpiece in the X and Y directions; and

[0011] The distance sensor is used to measure the distance from the distance sensor to the inner wall or outer wall of the annular workpiece.

[0012] Preferably, the distance sensor is a dispersive confocal sensor.

[0013] A method for centering a ring-shaped workpiece measuring system, based on the above-mentioned ring-shaped workpiece measuring system, comprises the following steps:

[0014] Step 1: Install the annular workpiece on the rotating table, control the XY positioning platform, and move the annular workpiece to within the travel range of the distance sensor. At this time, set the center coordinates of the rotating table to (0,0), the outer diameter of the annular workpiece to r, and the eccentricity of the center of the annular workpiece in the X and Y directions to x0 and y0 respectively;

[0015] Step 2, move the XY positioning platform along the Y direction so that the distance sensor measures the distance from it to the outer wall of the annular workpiece, and record the reading of the distance sensor at the minimum measurement value position as s1;

[0016] Step 3: Drive the rotating table to rotate the annular workpiece 180°, then move the XY positioning platform along the Y direction to allow the distance sensor to measure the distance to the outer wall of the annular workpiece, and record the reading of the distance sensor at the same time, where the reading at the position of the minimum measurement value is s3; since the coordinate of the distance sensor in the x direction has not changed during this process, it can be obtained:

[0017] s1+r+x0=s3+r-x0 (1)

[0018] Then,

[0019]

[0020] Step 4: Adjust the XY manual adjustment table to move the annular workpiece in the X direction by a distance of Δx=x0, and eliminate the eccentric distance of the annular workpiece in the X direction;

[0021] Step 5, drive the rotating table to rotate 90 degrees, move the XY positioning platform along the Y direction, so that the distance sensor measures the distance from it to the outer wall of the annular workpiece, and record the reading of the distance sensor at the same time, and record the reading of the minimum measurement value position as s4;

[0022] Step 6: Drive the rotating table to rotate the annular workpiece 180°, then move the XY positioning platform along the Y direction to allow the distance sensor to measure the distance to the outer wall of the annular workpiece, and record the reading of the distance sensor at the same time. The reading of the minimum measurement position is s5, from which we can get:

[0023] s4+r+y0=s5+r-y0 (3)

[0024] Then,

[0025]

[0026] Step seven, adjust the XY manual adjustment table to move the annular workpiece in the Y direction by a distance of Δy=y0, and eliminate the eccentric distance of the annular workpiece in the Y direction, and the centering is completed.

[0027] Step eight, repeating steps two to seven, to further reduce the eccentricity error of the annular workpiece in the XY direction.

[0028] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects:

[0029] The distance sensor of the present invention is used to detect the distance to the inner and outer walls of the annular workpiece. The minimum measurement value position can be used to realize the centering of the sensor, and the offset of the center of the annular workpiece is calculated at the same time. Then, the offset in the XY direction is eliminated respectively by the XY manual adjustment table, so as to realize the accurate centering of the annular workpiece. The measuring system and the centering method of the present invention have the characteristics of convenient operation and high detection accuracy.

[0030] In the present invention, the centering error of the annular workpiece can be controlled to a sub-micron level, and the centering error of the sensor can be controlled to a sub-micron level. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the measurement system of the present invention.

[0032] Figure 2 It is a schematic diagram of the principle of the sensor measuring distance of the present invention.

[0033] Figure 3 It is a schematic diagram of the principle of steps 2-3 of the present invention.

[0034] Figure 4 It is a schematic diagram of the principles of steps five and six of the present invention.

[0035] The meaning of the symbols in the figure:

[0036] 101-Y-axis driving platform; 102-X-axis driving platform; 103-rotating table; 104-manually adjustable mounting position; 105-XY manual adjustment table; 106-annular workpiece; 107-distance sensor; 108-sensor mounting bracket; 109-mounting platform. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with specific embodiments:

[0038] like Figure 1 As shown, a measuring system for annular workpieces is mainly used to measure annular thin-walled workpieces, and can also measure outer circular parts or inner circular hole parts. It includes an XY positioning platform, a rotating table 103, an XY manual adjustment table 105 and a distance sensor 107.

[0039] The XY positioning platform includes an X-direction driving platform 102 and a Y-direction driving platform 101, which are respectively used for moving and positioning the annular workpiece 106 in the X direction and the Y direction. The travel of the XY positioning platform is tens of millimeters, and the positioning accuracy is at the micron level.

[0040] The rotating table 103 is disposed on the XY positioning platform and is used for rotating the annular workpiece 106 .

[0041] The XY manual adjustment table 105 is arranged on the manual adjustment installation position 104 of the rotating table 103, and the XY manual adjustment table 105 is provided with a workpiece installation position for clamping the annular workpiece 106. The XY manual adjustment table 105 includes an X-direction translation fine adjustment component for X-direction movement and a Y-direction translation fine adjustment component for Y-direction movement, which are respectively used to fine-tune the X-direction and Y-direction positions of the annular workpiece 106 to achieve the centering of the annular workpiece 106. Among them, the adjustment range of the XY manual adjustment table 105 is at the millimeter level, and the adjustment accuracy can reach the micrometer level.

[0042] The distance sensor 107 is preferably a dispersive confocal sensor, which is used to measure the distance from the distance sensor 107 to the inner wall or outer wall of the annular workpiece 106. The dispersive confocal sensor is in the shape of a long strip and is vertically mounted on the mounting platform 109 through the sensor mounting frame 108. The mounting platform 109 is a Z-direction driving platform and can move in the Z direction. Among them, the dispersive confocal sensor emits light at 90° and can directly measure the wall surface of an annular thin-walled workpiece with an accuracy of tens of nanometers.

[0043] In this embodiment, the X-axis driving platform 102, the Y-axis driving platform 101 and the Z-axis driving platform all include a servo motor, a screw transmission structure and a slide, and the servo motor drives the slide to perform linear motion through the screw transmission structure. The stroke of the XY positioning platform is tens of mm, and the positioning accuracy is at the um level. The positioning accuracy of the rotating table 103 is at the arc second level, and the rotation accuracy is at the um level.

[0044] In addition, the structures of the X-axis translation fine-tuning assembly and the Y-axis translation fine-tuning assembly are similar to the drive platform structure. Generally, the manually controlled screw transmission structure drives the slide to perform linear motion. Its stroke is at the mm level and the adjustment accuracy is at the μm level.

[0045] like Figure 2 As shown, the dispersive confocal sensor is turned on and the annular thin-walled workpiece is moved in one direction. The dispersive confocal sensor can measure the distance from the annular thin-walled workpiece to the outer wall in real time. The distance of the distance sensor 107 at the starting position is S begin , the distance to the end position is S end , the distance to the minimum measured value is S min .

[0046] A method for centering a ring-shaped workpiece measuring system, based on the ring-shaped workpiece measuring system, comprises the following steps:

[0047] Step 1, install the annular workpiece 106 on the rotating table 103, control the XY positioning platform, and move the annular workpiece 106 to the travel range of the distance sensor 107; at this time, set the center coordinates of the rotating table 103 to (0,0), the outer diameter of the annular workpiece 106 to r, and set the eccentricity values ​​of the center of the annular workpiece 106 in the X and Y directions to x0 and y0 respectively, that is, the starting coordinates of the center of the annular workpiece 106 are (x0, y0).

[0048] Step 2: Move the XY positioning platform along the Y direction so that the distance sensor 107 measures the distance to the outer wall of the annular workpiece 106, and record the reading of the distance sensor 107, wherein the reading at the minimum measurement value position is s1, and move to the minimum measurement value position. Figure 3 As shown, the 0° position of the sensor is when the distance sensor 107 is at the minimum measuring position.

[0049] Step three: drive the rotating table 103 to rotate the annular workpiece 106 180° clockwise.

[0050] In order to more conveniently demonstrate the position of the distance sensor 107 in the following steps, assuming that the rotating table 103 is relatively stationary, it is equivalent to that the distance sensor 107 rotates around the center of the rotating table 103, wherein the rotation radius R is the distance from the distance sensor 107 to the center of the rotating table 103.

[0051] At this time, Figure 3 It can be seen from the figure that the 180° position of the sensor is the relative position of the distance sensor 107 after the annular workpiece 106 rotates 180° clockwise.

[0052] Then, the XY positioning platform is moved along the Y direction so that the distance sensor 107 measures the distance to the outer wall of the annular workpiece 106 , and the reading of the distance sensor 107 is recorded at the same time, wherein the reading at the starting position is s2 and the reading at the minimum measurement value position is s3.

[0053] Since the coordinate of the distance sensor 107 in the x direction does not change during this process, it can be obtained that:

[0054] s1+r+x0=s3+r-x0 (1)

[0055] Then,

[0056]

[0057] Step 4: adjust the XY manual adjustment table 105 to move the annular workpiece 106 in the X direction by a distance of Δx=x0, and eliminate the eccentric distance of the annular workpiece 106 in the X direction.

[0058] Step 5: Drive the rotating table 103 to rotate 90° counterclockwise, move the XY positioning platform along the Y direction, and make the distance sensor 107 measure the distance to the outer wall of the annular workpiece 106. Meanwhile, record the reading of the distance sensor 107, wherein the reading of the minimum measurement value position is s4, and move to the minimum measurement value position. Figure 4 As shown, the 90° position of the sensor is the relative position of the distance sensor 107 at this time.

[0059] Step 6: Drive the rotating table 103 to rotate the annular workpiece 106 180°, then move the XY positioning platform along the Y direction to allow the distance sensor 107 to measure the distance to the outer wall of the annular workpiece 106, and record the reading of the distance sensor 107 at the same time, wherein the reading at the position of the minimum measurement value is recorded as s5, as shown in FIG. Figure 4 As shown, the 270° position of the sensor is the relative position of the distance sensor 107 at this time. It can be obtained that:

[0060] s4+r+y0=s5+r-y0 (3)

[0061] Then,

[0062]

[0063] Step seven, adjust the XY manual adjustment table 105 to move the annular workpiece 106 in the Y direction by a distance of Δy=y0, and eliminate the eccentric distance of the annular workpiece 106 in the Y direction, and the centering is completed.

[0064] Step eight, repeating steps two to seven, to further reduce the eccentricity error of the annular workpiece 106 in the XY directions.

[0065] The present invention can reduce the centering error of the annular workpiece to the sub-micron level through multiple measurements of the distance sensor 107 and the centering process of the XY manual adjustment table, thereby improving the measurement accuracy of the inner and outer wall measurement system of the annular thin-walled workpiece.

[0066] In addition, step 4 can also be arranged after step 6, and together with step 7, the eccentricity distance of the annular workpiece 106 in the XY direction can be eliminated at the same time.

[0067] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A centering method for a ring-shaped workpiece measuring system, characterized in that: The method is based on a measuring system for an annular workpiece, the measuring system comprising: XY positioning platform, used for the movement and positioning of the annular workpiece in the X and Y directions; A rotating table, arranged on the XY positioning platform, is used for rotating the annular workpiece; An XY manual adjustment table is arranged on the rotating table, and a workpiece mounting position for clamping an annular workpiece is arranged on the XY manual adjustment table; the XY manual adjustment table is used to fine-tune the position of the annular workpiece in the X and Y directions; and A distance sensor is used to measure the distance from the distance sensor to the inner wall or outer wall of the annular workpiece; Based on the above measurement system, the method comprises the following steps: Step 1: Install the annular workpiece on the rotating table, control the XY positioning platform, and move the annular workpiece to within the travel range of the distance sensor. At this time, set the center coordinates of the rotating table to (0,0), the outer diameter of the annular workpiece to r, and the eccentricity of the center of the annular workpiece in the X and Y directions to x0 and y0 respectively; Step 2, move the XY positioning platform along the Y direction so that the distance sensor measures the distance from it to the outer wall of the annular workpiece, and record the reading of the distance sensor at the minimum measurement value position as s1; Step 3: Drive the rotating table to rotate the annular workpiece 180°, then move the XY positioning platform along the Y direction to allow the distance sensor to measure the distance to the outer wall of the annular workpiece, and record the reading of the distance sensor at the same time, where the reading at the position of the minimum measurement value is s3; since the coordinate of the distance sensor in the x direction has not changed during this process, it can be obtained: s1+r+x0=s3+r-x0 (1) Then, Step 4: Adjust the XY manual adjustment table to move the annular workpiece in the X direction by a distance of Δx=x0, and eliminate the eccentric distance of the annular workpiece in the X direction; Step 5, drive the rotating table to rotate 90 degrees, move the XY positioning platform along the Y direction, so that the distance sensor measures the distance from it to the outer wall of the annular workpiece, and record the reading of the distance sensor at the same time, and record the reading of the minimum measurement value position as s4; Step 6: Drive the rotating table to rotate the annular workpiece 180°, then move the XY positioning platform along the Y direction to allow the distance sensor to measure the distance to the outer wall of the annular workpiece, and record the reading of the distance sensor at the same time. The reading of the minimum measurement position is s5, from which we can get: s4+r+y0=s5+r-y0 (3) Then, Step seven, adjust the XY manual adjustment table to move the annular workpiece in the Y direction by a distance of Δy=y0, and eliminate the eccentric distance of the annular workpiece in the Y direction, and the centering is completed.

2. The centering method of a ring-shaped workpiece measuring system according to claim 1, characterized in that: The distance sensor is a dispersive confocal sensor.

3. A method for centering a ring-shaped workpiece measuring system according to claim 1 or 2, characterized in that: Also includes: Step eight, repeating steps two to seven, to further reduce the eccentricity error of the annular workpiece in the XY direction.

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