A method for on-line measurement of coaxiality of motor core

Abstract

The application discloses a motor iron core coaxiality on-line measurement method and belongs to the technical field of motors, and comprises the following steps: calculating the fitting circle center coordinates of the outer circle surface of the motor iron core; calculating the fitting circle center coordinates of the inner circle surface of the motor iron core; moving the motor iron core up and down along the Z axis to obtain the fitting circle center coordinates of the outer circle surface and the fitting circle center coordinates of the inner circle surface of the motor iron core at different laminated sheets; calculating the straight line equation of the fitting straight line L1 of the outer circle surface or the straight line equation of the fitting straight line L2 of the inner circle surface of the motor iron core; and calculating the distance from the circle center of each layer of the inner circle surface to the fitting straight line L1 of the outer circle surface or the distance from the circle center of each layer of the outer circle surface to the fitting straight line L2 of the inner circle surface of the motor iron core. According to the motor iron core coaxiality on-line measurement method, only the coordinate data points of the outer circle surface and the inner circle surface of the motor iron core need to be collected, data processing is then performed, the coaxiality of the motor iron core can be obtained, the accuracy is high, the stability is high, the precision is high, the labor cost is saved, and the detection efficiency and the accuracy of detection data are improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to an online method for measuring the coaxiality of a motor core. Background Technology

[0002] The coaxiality of motor cores is generally tested manually or semi-automatically. The workpiece is manually or semi-automatically positioned and measured. After the measurement is completed, the corresponding display terminal shows the measured value of the workpiece size and determines whether it is qualified or unqualified. The workpiece is then manually removed and placed in the qualified or unqualified material box according to the judgment result. The operator's workload is high, which can easily lead to misjudgment. Moreover, most of the time, the workpieces are only taken to the measuring table for testing after a batch of workpieces has been produced. If a production accident such as tool breakage occurs, the problem will often cause a batch of finished parts to be scrapped by the time the inspection is discovered, which wastes materials and time. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an efficient and highly accurate online method for measuring the coaxiality of motor cores.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A method for online measurement of the coaxiality of a motor core includes the following steps:

[0006] Calculate the fitted center coordinates of the outer circular surface of the motor core: Scan the outer circular surface of the motor core using a first laser displacement sensor to obtain n (n≥2) coordinate data points (x... n y n Using the least squares method, the equation of the circle for the outer circular surface M1 is fitted as follows:

[0007] (x-x0) 2 +(y-y0) 2 =r1 2 (1)

[0008] in,

[0009]

[0010] in,

[0011]

[0012] The fitted center coordinates of the outer circular surface of the motor core are (x0, y0, z0), where z0 is a known value;

[0013] Calculate the fitted center coordinates of the inner circular surface of the motor core: Scan the inner circular surface of the motor core using a second laser displacement sensor to obtain i (i≥2) coordinate data points (x... iy i Using the least squares method, the equation of the circle of the inner circular surface M2 is fitted as follows:

[0014] (xx t ) 2 +(yy t ) 2 =r2 2 (9)

[0015] in,

[0016]

[0017] in,

[0018]

[0019] The fitted center coordinates of the inner circular surface of the motor core are (x t y t , z t ), where z t The value is known.

[0020] Move the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer circle and the inner circle at different laminations of the motor core.

[0021] Calculate the equation of the fitted line L1 on the outer circular surface of the motor core or the equation of the fitted line L2 on the inner circular surface: Use the least squares method to fit the spatial lines L1 or L2. The standard form of the equation of the fitted line L1 is:

[0022]

[0023] Equivalent transformation of equation (17) yields: in,

[0024]

[0025] (x s y s , z s Let ) be any point on the fitted line L1;

[0026] The standard form of the equation of the fitted line L2 is:

[0027]

[0028] Equivalent transformation of equation (24) yields: in,

[0029]

[0030] (xp y p , z p Let ) be any point on the fitted line L2;

[0031] Calculate the distance d from the center of the inner circle of each layer of the motor core to the fitted straight line L1 on the outer circle. i Or the distance d from the center of each outer circular surface to the fitted straight line L2 of the inner circular surface. n :

[0032]

[0033]

[0034] Calculate the coaxiality φ of the motor core: determine the maximum value from a plurality of the stated distances, wherein the coaxiality φ of the motor core is twice the maximum value.

[0035] φ=2max(d i ) or φ = 2max(d n ).

[0036] Furthermore, the step of moving the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer and inner circular surfaces of the motor core at different laminations specifically includes the following steps:

[0037] By having two first laser displacement sensors arranged along the radial direction of the motor core come into contact with the first outer circular surface of the motor core, the fitted center coordinates of the first outer circular surface are obtained.

[0038] The distance the drive motor core moves along the Z-axis is u1. Two first laser displacement sensors abut against the v1-th outer circular surface of the motor core, thereby obtaining the fitted center coordinates of the v1-th outer circular surface. h is the lamination thickness of the motor core, and u1 is an integer multiple of h;

[0039] By having two second laser displacement sensors arranged along the radial direction of the motor core contact the first inner circular surface of the motor core, the fitted center coordinates of the first inner circular surface are obtained.

[0040] The distance the drive motor core moves along the Z-axis is u2. Two second laser displacement sensors abut against the inner circular surface of the v2-th layer of the motor core, thereby obtaining the fitted center coordinates of the inner circular surface of the v2-th layer. h is the lamination thickness of the motor core, and u2 is an integer multiple of h.

[0041] Furthermore, in the step of calculating the linear equation of the fitting line L1 on the outer circular surface of the motor core or the linear equation of the fitting line L2 on the inner circular surface,

[0042] Furthermore, the calculation of the linear equation of the fitted straight line L1 on the outer circular surface of the motor core specifically includes the following steps:

[0043] Choose any z s The value is obtained by calculating x based on k1, k2, b1, and b2. s y s ;

[0044] Choose any value for C1, and based on k1 and k2, calculate the values ​​of A1 and B1 to obtain the equation of the fitted line L1.

[0045] Furthermore, in the step of calculating the linear equation of the fitting line L1 on the outer circular surface of the motor core or the linear equation of the fitting line L2 on the inner circular surface,

[0046] Furthermore, the calculation of the linear equation of the fitted straight line L2 on the outer circular surface of the motor core specifically includes the following steps:

[0047] Choose any z p The value is obtained by calculating x based on k3, k4, b3, and b4. p y p ;

[0048] Choose any value for C2, and based on k3 and k4, calculate the values ​​of A2 and B2 to obtain the equation of the fitted line L2.

[0049] Furthermore, in the step of calculating the fitted center coordinates of the outer circular surface of the motor core, r1 is the radius of the fitted circular surface of the outer circular surface of the motor core.

[0050]

[0051] in,

[0052] Furthermore, in the step of calculating the fitted center coordinates of the inner circular surface of the motor core, r2 is the radius of the fitted circular surface of the inner circular surface of the motor core.

[0053]

[0054] in,

[0055] Furthermore, the online measurement method for the coaxiality of the motor core also includes a verification step, which is located after the step of calculating the coaxiality φ of the motor core, and specifically includes the following steps:

[0056] The actual coaxiality φ' of the motor core is measured using a measuring instrument;

[0057] Calculate the error between the coaxiality φ of the motor core and the actual coaxiality φ';

[0058] If the error is within the preset range, it means that the motor core is qualified; if the error is not within the preset range, formulas (4)-(8) and formulas (12)-(16) should be corrected.

[0059] Furthermore, in the step of calculating the coaxiality φ of the motor core, the magnitude of the coaxiality φ is 0 to 0.1 mm.

[0060] Compared with the prior art, the online measurement method for the coaxiality of the motor core of the present invention includes the following steps: calculating the fitted center coordinates of the outer circular surface of the motor core; calculating the fitted center coordinates of the inner circular surface of the motor core; moving the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer circular surface and the fitted center coordinates of the inner circular surface at different layers of the motor core; calculating the linear equation of the fitted line L1 of the outer circular surface or the linear equation of the fitted line L2 of the inner circular surface of the motor core; calculating the distance from the center of the inner circular surface of each layer of the motor core to the fitted line L1 of the outer circular surface or the distance from the center of the outer circular surface of each layer to the fitted line L2 of the inner circular surface; and calculating the coaxiality of the motor core. In this application, taking the inner circular surface of the motor core as a reference, points are taken on each layer of the inner circular surface of the motor core using a second laser displacement sensor, and multiple fitting circle center coordinates are calculated. Then, a spatial straight line L2 is obtained by fitting. Points are taken on each layer of the outer circular surface of the motor core using a first laser displacement sensor, and multiple fitting circle center coordinates are calculated. Then, the distance from the fitting circle center of each layer of the outer circular surface of the motor core to the fitting straight line L2 is calculated. The largest distance value is then selected for calculation to obtain the final coaxiality φ of the motor core. This application only requires collecting coordinate data points of the outer and inner circular surfaces of the motor core, and then processing the data to obtain the coaxiality of the motor core. The accuracy of the obtained coaxiality is very high. Compared with manual inspection methods, it has high stability, high precision, and saves labor costs, greatly improving inspection efficiency and the accuracy of inspection data. This helps to improve the quality control of motor core manufacturing and meet customer needs. By setting up several sets of first laser displacement sensors and several sets of second laser displacement sensors, this application can quickly and accurately measure the motor core, improving the automation level of workpiece inspection, while avoiding damage caused by contact measurement. The entire operation is simpler and more flexible. Attached Figure Description

[0061] Figure 1 This is a flowchart illustrating the steps of the online measurement method for the coaxiality of the motor core according to the present invention. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or it can be fixed through another intermediate component. When a component is said to be "connected to" another component, it can be directly connected to the other component or it may be fixed through another intermediate component. When a component is said to be "set on" another component, it can be set directly on the other component or it may be set through another intermediate component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0065] like Figure 1 As shown, the present invention provides an online method for measuring the coaxiality of a motor core, comprising the following steps:

[0066] Calculate the fitted center coordinates of the outer circular surface of the motor core: Scan the outer circular surface of the motor core using a first laser displacement sensor to obtain n (n≥2) coordinate data points (x... n y n Using the least squares method, the equation of the circle for the outer circular surface M1 is fitted as follows:

[0067] (x-x0) 2 +(y-y0) 2 =r1 2 (1)

[0068] in,

[0069]

[0070] in,

[0071]

[0072] The fitted center coordinates of the outer circular surface of the motor core are (x0, y0, z0), where z0 is a known value;

[0073] Calculate the fitted center coordinates of the inner circular surface of the motor core: Scan the inner circular surface of the motor core using a second laser displacement sensor to obtain i (i≥2) coordinate data points (x... i y i Using the least squares method, the equation of the circle of the inner circular surface M2 is fitted as follows:

[0074] (xx t ) 2 +(yy t ) 2 =r2 2 (9)

[0075] in,

[0076]

[0077] in,

[0078]

[0079] The fitted center coordinates of the inner circular surface of the motor core are (x t y t , z t ), where z t The value is known.

[0080] Move the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer circle and the inner circle at different laminations of the motor core.

[0081] Calculate the equation of the fitted line L1 on the outer circular surface of the motor core or the equation of the fitted line L2 on the inner circular surface: Use the least squares method to fit the spatial line L1 or L2.

[0082] The standard form of the equation of the fitted line L1 is:

[0083]

[0084] Equivalent transformation of equation (17) yields: in,

[0085]

[0086] (x s y s , z s Let ) be any point on the fitted line L1;

[0087] The standard form of the equation of the fitted line L2 is:

[0088]

[0089] Equivalent transformation of equation (24) yields:

[0090] in,

[0091]

[0092] (x p y p , z p Let ) be any point on the fitted line L2;

[0093] Calculate the distance d from the center of the inner circle of each layer of the motor core to the fitted straight line L1 on the outer circle. i Or the distance d from the center of each outer circular surface to the fitted straight line L2 of the inner circular surface. n :

[0094]

[0095]

[0096] Calculate the coaxiality φ of the motor core: Determine the maximum value from several distances; the coaxiality φ of the motor core is twice the maximum value.

[0097] φ=2max(d i ) or φ = 2max(d n ).

[0098] In the step of calculating the fitted center coordinates of the outer circular surface of the motor core, for each layer of the outer circular surface of the motor core, the coordinates of the points on the outer circular surface and the coordinates of the fitted center of the outer circular surface are the same in the Z-axis direction. Therefore, the first displacement sensor can be used to select points on each layer of the outer circular surface in a two-dimensional plane. Additionally, the radius r1 of the fitted circular surface of the outer circular surface of the motor core can be calculated based on the fitted center coordinates.

[0099]

[0100] in,

[0101] In the step of calculating the fitted center coordinates of the inner circular surface of the motor core, for each layer of the inner circular surface of the motor core, the coordinates of the points taken on the inner circular surface and the coordinates of the fitted center of the inner circular surface are the same in the Z-axis direction. Therefore, a second displacement sensor can be used to take points on each layer of the inner circular surface in a two-dimensional plane. Since the inner diameter of the motor core is small, ordinary sensors cannot extend into the motor core. Therefore, the second displacement sensor includes a side extension rod, which is needed for measurement. In addition, the radius r2 of the fitted circular surface of the inner circular surface of the motor core can be calculated based on the fitted center coordinates.

[0102]

[0103] in,

[0104] Moving the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer and inner circular surfaces of the motor core at different laminations specifically includes the following steps:

[0105] By having two first laser displacement sensors arranged along the radial direction of the motor core come into contact with the first outer circular surface of the motor core, the fitted center coordinates of the first outer circular surface are obtained.

[0106] The distance the drive motor core moves along the Z-axis is u1. Two first laser displacement sensors abut against the v1-th outer circular surface of the motor core, thereby obtaining the fitted center coordinates of the v1-th outer circular surface. h is the thickness of the laminations of the motor core, and u1 is an integer multiple of h; this ensures that the first laser displacement sensor is in contact with the middle position of the outer circular surface of each motor core lamination, at which point the measurement accuracy is high.

[0107] By having two second laser displacement sensors arranged along the radial direction of the motor core contact the first inner circular surface of the motor core, the fitted center coordinates of the first inner circular surface are obtained.

[0108] The distance the drive motor core moves along the Z-axis is u2. Two second laser displacement sensors abut against the inner circular surface of the v2-th layer of the motor core, thereby obtaining the fitted center coordinates of the inner circular surface of the v2-th layer. h represents the thickness of the laminations in the motor core, and u2 is an integer multiple of h. This ensures that the second laser displacement sensor is in contact with the center of the inner circular surface of each lamination in the motor core, resulting in high measurement accuracy.

[0109] In the steps of calculating the equation of the straight line L1 fitted to the outer circular surface of the motor core or the equation of the straight line L2 fitted to the inner circular surface,

[0110] The specific steps for calculating the equation of the fitted straight line L1 on the outer circular surface of the motor core are as follows:

[0111] Choose any z s The value is obtained by calculating x based on k1, k2, b1, and b2. s y s ;

[0112] Choose any value for C1, and based on k1 and k2, calculate the values ​​of A1 and B1 to obtain the equation of the fitted line L1.

[0113] In the steps of calculating the equation of the straight line L1 fitted to the outer circular surface of the motor core or the equation of the straight line L2 fitted to the inner circular surface,

[0114] The specific steps for calculating the equation of the fitted straight line L2 on the outer circular surface of the motor core are as follows:

[0115] Choose any z p The value is obtained by calculating x based on k3, k4, b3, and b4. p y p ;

[0116] Choose any value for C2, and based on k3 and k4, calculate the values ​​of A2 and B2 to obtain the equation of the fitted line L2.

[0117] The online measurement method for the coaxiality of the motor core also includes a verification step, which is located after the step of calculating the coaxiality φ of the motor core. Specifically, it includes the following steps:

[0118] The actual coaxiality φ' of the motor core is measured using a measuring instrument;

[0119] Calculate the error between the coaxiality φ of the motor core and the actual coaxiality φ';

[0120] If the error is within the preset range, it means that the motor core is qualified; if the error is not within the preset range, formulas (4)-(8) and formulas (12)-(16) should be corrected.

[0121] In the step of calculating the coaxiality φ of the motor core, the value of coaxiality φ is 0 to 0.1 mm.

[0122] In this application, taking the inner circular surface of the motor core as a reference, points are taken on each layer of the inner circular surface of the motor core using a second laser displacement sensor, and multiple fitting circle center coordinates are calculated. Then, a spatial straight line L2 is obtained by fitting. Points are taken on each layer of the outer circular surface of the motor core using a first laser displacement sensor, and multiple fitting circle center coordinates are calculated. Then, the distance from the fitting circle center of each layer of the outer circular surface of the motor core to the fitting straight line L2 is calculated. The largest distance value is then selected for calculation to obtain the final coaxiality φ of the motor core. This application only requires collecting coordinate data points of the outer and inner circular surfaces of the motor core, and then processing the data to obtain the coaxiality of the motor core. The accuracy of the obtained coaxiality is very high. Compared with manual inspection methods, it has high stability, high precision, and saves labor costs, greatly improving inspection efficiency and the accuracy of inspection data. This helps to improve the quality control of motor core manufacturing and meet customer needs. By setting up several sets of first laser displacement sensors and several sets of second laser displacement sensors, this application can quickly and accurately measure the motor core, improving the automation level of workpiece inspection, while avoiding damage caused by contact measurement. The entire operation is simpler and more flexible.

[0123] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A method for online measurement of the coaxiality of a motor core, characterized in that: Includes the following steps: Calculate the fitted center coordinates of the outer circular surface of the motor core: Scan the outer circular surface of the motor core using a first laser displacement sensor to obtain n (n≥2) coordinate data points (x... n y n Using the least squares method, the equation of the circle for the outer circular surface M1 is fitted as follows: (x-x0) 2 +(y-y0) 2 =r1 2 (1) in, in, The fitted center coordinates of the outer circular surface of the motor core are (x0, y0, z0), where z0 is a known value; Calculate the fitted center coordinates of the inner circular surface of the motor core: Scan the inner circular surface of the motor core using a second laser displacement sensor to obtain i (i≥2) coordinate data points (x... i y i Using the least squares method, the equation of the circle of the inner circular surface M2 is fitted as follows: (x-x t ) 2 +(y-y t ) 2 =r2 2 (9) in, in, The fitted center coordinates of the inner circular surface of the motor core are (x t y t , z t ), where z t The value is known. Move the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer circle and the inner circle at different laminations of the motor core. Calculate the equation of the fitted line L1 on the outer circular surface of the motor core or the equation of the fitted line L2 on the inner circular surface: Use the least squares method to fit the spatial line L1 or L2. The standard form of the equation of the fitted line L1 is: Equivalent transformation of equation (17) yields: in, (x s y s , z s Let ) be any point on the fitted line L1; The standard form of the equation of the fitted line L2 is: Equivalent transformation of equation (24) yields: in, (x p y p , z p Let ) be any point on the fitted line L2; Calculate the distance d from the center of the inner circle of each layer of the motor core to the fitted straight line L1 on the outer circle. i Or the distance d from the center of each outer circular surface to the fitted straight line L2 of the inner circular surface. n : Calculate the coaxiality φ of the motor core: determine the maximum value from a plurality of the stated distances, wherein the coaxiality φ of the motor core is twice the maximum value. φ=2max(d i ) or φ = 2max(d n ).

2. The online measurement method for the coaxiality of the motor core according to claim 1, characterized in that: The process of moving the motor core up and down along the Z-axis to obtain the fitted center coordinates of the outer and inner circular surfaces of the motor core at different laminations specifically includes the following steps: By having two first laser displacement sensors arranged along the radial direction of the motor core come into contact with the first outer circular surface of the motor core, the fitted center coordinates of the first outer circular surface are obtained. The distance the drive motor core moves along the Z-axis is u1. Two first laser displacement sensors abut against the v1-th outer circular surface of the motor core, thereby obtaining the fitted center coordinates of the v1-th outer circular surface. h is the lamination thickness of the motor core, and u1 is an integer multiple of h; By having two second laser displacement sensors arranged along the radial direction of the motor core contact the first inner circular surface of the motor core, the fitted center coordinates of the first inner circular surface are obtained. The distance the drive motor core moves along the Z-axis is u2. Two second laser displacement sensors abut against the inner circular surface of the v2-th layer of the motor core, thereby obtaining the fitted center coordinates of the inner circular surface of the v2-th layer. h is the lamination thickness of the motor core, and u2 is an integer multiple of h.

3. The online measurement method for the coaxiality of the motor core according to claim 1, characterized in that: In the step of calculating the linear equation of the fitted line L1 on the outer circular surface of the motor core or the linear equation of the fitted line L2 on the inner circular surface, 4. The online measurement method for the coaxiality of the motor core according to claim 3, characterized in that: The calculation of the linear equation of the fitted line L1 on the outer circular surface of the motor core specifically includes the following steps: Choose any z s The value is obtained by calculating x based on k1, k2, b1, and b2. s y s ; Choose any value for C1, and based on k1 and k2, calculate the values ​​of A1 and B1 to obtain the equation of the fitted line L1.

5. The method for online measurement of coaxiality of motor core according to claim 1, characterized in that: In the step of calculating the linear equation of the fitted line L1 on the outer circular surface of the motor core or the linear equation of the fitted line L2 on the inner circular surface, 6. The online measurement method for the coaxiality of the motor core according to claim 5, characterized in that: The calculation of the linear equation of the fitted straight line L2 on the outer circular surface of the motor core specifically includes the following steps: Choose any z p The value is obtained by calculating x based on k3, k4, b3, and b4. p y p ; Choose any value for C2, and based on k3 and k4, calculate the values ​​of A2 and B2 to obtain the equation of the fitted line L2.

7. The method for online measurement of coaxiality of motor core according to claim 1, characterized in that: In the step of calculating the fitted center coordinates of the outer circular surface of the motor core, r1 is the radius of the fitted circular surface of the outer circular surface of the motor core. in, 8. The method for online measurement of coaxiality of motor core according to claim 1, characterized in that: In the step of calculating the fitted center coordinates of the inner circular surface of the motor core, r2 is the radius of the fitted circular surface of the inner circular surface of the motor core. in, 9. The method for online measurement of coaxiality of motor core according to claim 1, characterized in that: The online measurement method for the coaxiality of the motor core further includes a verification step, which is located after the step of calculating the coaxiality φ of the motor core, and specifically includes the following steps: The actual coaxiality φ' of the motor core is measured using a measuring instrument; Calculate the error between the coaxiality φ of the motor core and the actual coaxiality φ'; If the error is within the preset range, it means that the motor core is qualified; if the error is not within the preset range, formulas (4)-(8) and formulas (12)-(16) should be corrected.

10. The method for online measurement of coaxiality of motor core according to claim 1, characterized in that: In the step of calculating the coaxiality φ of the motor core, the magnitude of the coaxiality φ is 0 to 0.1 mm.

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