Pose adjusting method of deep micropore workpiece in three-coordinate measuring machine

Abstract

The invention discloses a pose adjusting method of a deep micropore workpiece in a three-coordinate measuring machine, the deep micropore workpiece is placed in the three-coordinate measuring machine as a to-be-measured workpiece, a moving measuring needle is used for detecting a cylindrical hole in the deep micropore workpiece, and the roundness of the cylindrical hole is measured; setting the Z axis of the three-coordinate measuring machine to be vertical, and setting the XOY surface to be horizontal; the center axis of the probe is parallel to the Z axis of the three-coordinate measuring machine. According to the pose adjusting method of the deep micropore workpiece in the three-coordinate measuring machine, the levelness of the deep micropore workpiece in the X-axis direction and / or the Y-axis direction is adjusted, so that the central axis of a cylindrical hole in the deep micropore workpiece is parallel to the Z-axis of the three-coordinate measuring machine. According to the invention, the accuracy and integrity of measurement data for measuring the deep micropore workpiece in the three-coordinate measuring machine by using the probe can be effectively ensured.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and more specifically to a method for adjusting the position and posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine, especially for the application of measuring the deep micro-hole workpiece with a contact probe. Background Art

[0002] Deep micro holes with high aspect ratios are widely present in various mechanical workpieces. The machining accuracy of deep micro holes affects the performance of the workpiece. Usually, holes with an aspect ratio greater than 5 are considered to have high aspect ratio characteristics, i.e., deep micro holes. Such holes usually need to be measured using contact measurement. In the prior art, contact measurement is often used in three-dimensional coordinate measuring machines, which have good repeatability and are widely used in precision measurement. For example, in the invention patent specification with publication number CN113237425A, the applicant proposed an automatic guidance method for measuring tiny workpieces with a single camera-assisted coordinate measuring machine, which can quickly and accurately guide the probe to the measurement position of the workpiece to be measured, and then implement contact measurement.

[0003] For a three-dimensional coordinate measuring machine that uses a stylus for contact measurement, the stylus calibration process before measurement is to ensure that the center axis of the stylus in the three-dimensional coordinate measuring machine is consistent with the Z-axis direction of the three-dimensional coordinate measuring machine, that is, the position of the workpiece to be measured is upright, the inner wall of the measuring hole is vertical, and the vertical stylus and the inner wall of the measuring hole are parallel to each other. However, in actual measurement, it is often the case that the position of the workpiece to be measured is not upright, and the inner wall of the measuring hole has an inclination angle. When the stylus is translated in the vertical plane, it is blocked by the upper edge of the inner wall of the measuring hole, resulting in a measurement blind area, and accurate and complete measurement data cannot be obtained. Summary of the invention

[0004] The present invention aims to avoid the deficiencies of the above-mentioned prior art and to provide a method for adjusting the posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine to ensure the accuracy and completeness of the measurement data when a probe is used to perform contact measurement on the deep micro-hole workpiece in a three-dimensional coordinate measuring machine.

[0005] The present invention adopts the following technical solutions to achieve the purpose of the invention:

[0006] The present invention discloses a method for adjusting the posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine. The deep micro-hole workpiece is placed in the three-dimensional coordinate measuring machine as a workpiece to be measured, and a moving stylus is used to detect a cylindrical hole in the deep micro-hole workpiece to measure the roundness of the cylindrical hole. The three-dimensional coordinate measuring machine has a vertical Z axis and a horizontal XOY plane. The stylus has a stylus ball fixed at the lower end of a stylus rod, and the central axis of the stylus is parallel to the Z axis of the three-dimensional coordinate measuring machine.

[0007] The position and posture adjustment method of the deep micro-hole workpiece in the three-dimensional coordinate measuring machine of the present invention is characterized in that: the position and posture adjustment method of the deep micro-hole workpiece in the three-dimensional coordinate measuring machine is: by adjusting the horizontality of the deep micro-hole workpiece along the X-axis and / or the Y-axis, the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine.

[0008] The method for adjusting the position and posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine of the present invention is carried out in the following steps:

[0009] Step 1, guide the measuring needle to the measuring position of the workpiece to be measured, record the measuring position as the initial position O, and the coordinates of the initial position O are marked as O (x0, y0, z0);

[0010] Step 2: Move the probe from the initial position O in the positive direction along the X-axis until the probe touches the workpiece and generates a trigger signal to stop moving. The probe stops at position A, and the coordinates of position A are marked as A(x1, y0, z0);

[0011] Step 3, move the probe from position A along the negative direction of the X axis until the probe touches the workpiece to be measured and generates a trigger signal and stops moving. The probe stops at position B, and the coordinates of position B are marked as B (x2, y0, z0);

[0012] Step 4: Move the probe from position B in the positive direction along the X-axis until the probe returns to the initial position O and is controlled to stop moving;

[0013] Step 5: Move the probe vertically downward along the Z direction from the initial position O for a certain distance and stop moving when it reaches position C. The coordinates of position C are marked as C (x0, y0, z1);

[0014] Step 6, move the probe from position C along the positive direction of the X axis until the probe is controlled to stop moving due to the trigger signal generated by the workpiece to be measured, and the probe stops at position D, and the coordinates of position D are marked as D (x3, y0, z1);

[0015] Step 7, move the probe from position D along the negative direction of the X axis until the probe is controlled to stop moving due to the trigger signal generated by the workpiece to be measured, and the probe stops at position E, and the coordinates of position E are marked as E (x4, y0, z1);

[0016] Step 8: Record the line connecting position A and position D as straight line l AD , and the line connecting position B and position E is recorded as straight line l BE ;

[0017] Then we have: Line l AD The slope k AD for:

[0018] Straight line BEThe slope k BE for:

[0019] If the values ​​of (x3-x1) and (x4-x2) are both zero, it indicates that the posture of the deep micro-hole workpiece meets the requirements, and the posture adjustment is ended;

[0020] If one of the values ​​of (x3-x1) and (x4-x2) is zero and the other is not zero, it is judged that the posture of the deep micro-hole workpiece does not meet the requirements. The position adjustment is achieved by adjusting the horizontality of the deep micro-hole workpiece along the X-axis so that the center axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine.

[0021] The method for adjusting the position and posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine of the present invention is also characterized in that:

[0022] According to the calculated adjustment angle θ1, accurate posture adjustment is achieved as follows:

[0023] If the value of (x3-x1) is not zero, the value of (x4-x2) is zero, and the adjustment angle θ1 is calculated by formula (1):

[0024]

[0025] Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ1, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine;

[0026] If the value of (x3-x1) is zero and the value of (x4-x2) is not zero, the adjustment angle θ2 is calculated by formula (2):

[0027]

[0028] Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ2, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine;

[0029] The same method is used to complete the adjustment on the Y axis.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. The method of the present invention is simple and easy to implement, and can effectively ensure the accuracy and integrity of the measurement data of deep micro-hole workpieces measured by a measuring needle in a three-dimensional coordinate measuring machine;

[0032] 2. The present invention can be realized by adjusting the horizontality of the deep micro-hole workpiece along the X-axis and / or the Y-axis using a two-dimensional angle adjustment seat without changing the installation position of the measuring needle. The adjustment method is simple and reliable.

[0033] 3. The method of the present invention is applicable to various application occasions such as circular hole feature measurement, cylindrical surface measurement, and boss surface measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of a measurement system in which the feature to be measured is a circular hole;

[0035] Figure 2 Schematic diagram of a measurement system in which the feature to be measured is a cylinder;

[0036] Figure 3 It is a schematic diagram of the XOZ plane when the measuring needle moves along the X-axis toward the inner wall of the circular hole when the workpiece to be measured is tilted to the right;

[0037] Figure 4 It is a schematic diagram of the XOZ plane when the measuring needle moves along the X-axis toward the inner wall of the circular hole when the workpiece to be measured is tilted to the left;

[0038] Figure 5 It is a schematic diagram of the XOZ plane when the measuring needle moves along the Z axis toward the bottom of the circular hole when the workpiece to be measured is tilted to the right;

[0039] Figure 6 It is a schematic diagram of the XOZ plane when the measuring needle moves along the Z axis toward the bottom of the circular hole when the workpiece to be measured is tilted to the left;

[0040] Figure 7 It is a schematic diagram of the XOZ plane when the measuring needle moves along the X-axis toward the inner wall of the circular hole when the workpiece to be measured is tilted to the right;

[0041] Figure 8 It is a schematic diagram of the XOZ plane when the measuring needle moves along the X-axis toward the inner wall of the circular hole when the workpiece to be measured is tilted to the left;

[0042] Fig. 9 It is a schematic diagram of the XOZ plane when the angle θ1 is adjusted when the upper side of the workpiece to be measured is tilted to the left;

[0043] Fig.10 It is a schematic diagram of the XOZ plane when the angle θ2 is adjusted when the upper side of the workpiece to be measured is tilted to the left;

[0044] Numbers in the figure: 1 measuring needle, 2 measuring ball, 3 circular hole, which is the measuring feature on the workpiece to be measured, 4 workpiece to be measured, 5 two-dimensional angle adjustment seat, 6 boss, which is the measuring feature on the workpiece to be measured. DETAILED DESCRIPTION

[0045] In the present embodiment, the posture adjustment method of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine is as follows: the deep micro-hole workpiece is placed in the three-dimensional coordinate measuring machine as a workpiece to be measured, and a moving stylus is used to detect the cylindrical hole in the deep micro-hole workpiece to achieve measurement of the roundness of the cylindrical hole; the Z axis of the three-dimensional coordinate measuring machine is vertical, and its XOY plane is horizontal; the stylus is a stylus with a stylus ball fixed at the lower end of the stylus rod, and the center axis of the stylus is parallel to the Z axis of the three-dimensional coordinate measuring machine. By adjusting the horizontality of the deep micro-hole workpiece along the X axis and / or the Y axis, the center axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z axis of the three-dimensional coordinate measuring machine.

[0046] In this embodiment, in order to realize the posture adjustment of the deep micro-hole workpiece in the three-dimensional coordinate measuring machine, the following settings are made: Figure 1 and Figure 2 The two-dimensional angle adjustment seat 5 shown in the figure, the workpiece 4 to be measured is fixed on the two-dimensional angle adjustment seat 5, and the two-dimensional angle adjustment seat 5 is used to adjust the horizontality of the workpiece 4 to be measured along the X-axis and along the Y-axis, thereby adjusting the two mutually perpendicular angle postures of the workpiece 4 to be measured. The applicant has disclosed an automatic guidance method for measuring tiny workpieces with a single camera-assisted coordinate measuring machine in the invention patent specification with publication number CN113237425A. In this embodiment, the method is first used to guide the probe 1 to the measuring position of the workpiece 4 to be measured, and then the posture adjustment of the deep micro-hole workpiece in the three-dimensional coordinate measuring machine is performed according to the following steps:

[0047] Step 1: The measuring needle is located at the measuring position of the workpiece 4 to be measured. The measuring position is recorded as the initial position O, and the coordinates of the initial position O are recorded as O(x0, y0, z0).

[0048] Step 2: Move the probe from the initial position O in the positive direction along the X-axis until the probe touches the workpiece 4 and generates a trigger signal to stop moving. The probe 1 stops at position A. The coordinates of position A are marked as A(x1, y0, z0). Figure 3 (b) and Figure 4 (b) as shown.

[0049] Step 3: Move the probe from position A along the negative direction of the X axis until the probe touches the workpiece 4 and generates a trigger signal to stop moving. The probe 1 stops at position B. The coordinates of position B are marked as B (x2, y0, z0). Figure 3 (c) and Figure 4 (c)).

[0050] Step 4: Move the probe 1 from position B in the positive direction along the X-axis until the probe 1 returns to the initial position O and is controlled to stop moving.

[0051] Step 5: Move the probe 1 vertically downward from the initial position O along the Z direction for a certain distance and stop moving when it reaches position C. The coordinates of position C are marked as C(x0, y0, z1). Figure 5 and Figure 6 shown.

[0052] Step 6: Move the probe 1 from position C in the positive direction along the X axis until the probe 1 is controlled to stop moving due to the trigger signal generated by the workpiece 4 to be measured. The probe 1 stops at position D. The coordinates of position D are marked as D(x3, y0, z1). Figure 7 (b) and Figure 8 (b) as shown.

[0053] Step 7: Move the probe from position D along the negative direction of the X axis until the probe stops moving due to the trigger signal generated by the workpiece to be measured. The probe stops at position E. The coordinates of position E are marked as E(x4, y0, z1). Figure 7 (c) and Figure 8 (c) as shown.

[0054] Step 8: Record the line connecting position A and position D as straight line l AD , and the line connecting position B and position E is recorded as straight line l BE ;

[0055] Then we have: Line l AD The slope k AD for:

[0056] Straight line BE The slope k BE for:

[0057] If the values ​​of (x3-x1) and (x4-x2) are both zero, it indicates that the posture of the deep micro-hole workpiece meets the requirements, and the posture adjustment is ended;

[0058] If one of the values ​​of (x3-x1) and (x4-x2) is zero and the other is not zero, it is judged that the posture of the deep micro-hole workpiece does not meet the requirements. The position adjustment is achieved by adjusting the horizontality of the deep micro-hole workpiece along the X-axis so that the center axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine.

[0059] In the specific implementation, the posture is accurately adjusted according to the calculated adjustment angle θ1 as follows:

[0060] If the value of (x3-x1) is not zero, the value of (x4-x2) is zero, and the adjustment angle θ1 is calculated by formula (1):

[0061]

[0062] Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ1, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine;

[0063] If the value of (x3-x1) is zero and the value of (x4-x2) is not zero, the adjustment angle θ2 is calculated by formula (2):

[0064]

[0065] Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ2, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine;

[0066] The same method is used to complete the adjustment on the Y axis.

[0067] Figure 1 and Figure 2 As shown, the workpiece 4 to be measured is fixed on the two-dimensional angle adjustment seat 5, and the two-dimensional angle adjustment seat 5 is used to adjust the horizontality of the workpiece 4 to be measured along the X-axis and along the Y-axis, thereby adjusting the two mutually perpendicular angle postures of the workpiece 4 to be measured. Figure 1 The workpiece feature of the workpiece 4 to be measured is a circular hole 3, Figure 2 The workpiece feature in the workpiece 4 to be measured is a boss 6 .

[0068] This embodiment adopts Figure 1 The system shown in the figure realizes the position adjustment of the workpiece measured by the coordinate measuring machine according to the following process, taking the circular hole as an example of the concave feature to be measured:

[0069] like Figure 3 , Figure 5 and Figure 7 As shown, the workpiece to be measured faces right above, and the workpiece 4, the measuring needle 1, and the measuring ball 2 are projected onto the XOZ plane for observation. The measuring needle 1 is guided to the measuring position of the workpiece 4 to be measured, i.e., the initial position O (x0, y0, z0), by using the automatic guiding method for measuring tiny workpieces using a single camera-assisted coordinate measuring machine disclosed in the invention patent specification with publication number CN113237425A.

[0070] Step 1: Figure 3 As shown in (a), the probe 1 is first moved in the positive direction along the X-axis until the probe 1 generates a trigger signal due to touching the workpiece 4 to be measured and stops at position A (x1, y0, z0). Figure 3 (b); then move the probe 1 in the negative direction of the X-axis until the probe 1 generates a trigger signal due to touching the workpiece 4 to be measured and stops at position B (x2, y0, z0), as shown in FIG. Figure 3 (c) as shown.

[0071] Step 2: Move the probe 1 in the positive direction along the X-axis until the probe 1 returns to the initial position O and is controlled to stop moving. Figure 5 As shown in (a), the probe 1 is moved downward along the Z axis for a distance to reach position C (x0, y0, z1). Figure 5 (b)

[0072] Step 3 Figure 7 As shown in (a), the stylus 1 is moved again in the positive direction along the X-axis until the stylus 1 generates a trigger signal due to touching the workpiece 4 to be measured and stops at position D (x3, y0, z1). Figure 7 (b) shows that the stylus 1 is moved in the negative direction of the X-axis until the stylus 1 generates a trigger signal due to touching the workpiece 4 to be measured and stops at position E (x4, y0, z1). Figure 7 (c)

[0073] Step 4: Connect position A and position D to get straight line l AD , connecting position B and position E, we have a straight line l BE , and have:

[0074] Straight line AD The slope k AD for: Straight line BE The slope k BE for:

[0075] At this time, the workpiece to be measured is tilted to the left, and the adjustment angle θ1 is calculated by formula (1), as follows: Fig. 9 As shown:

[0076] Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ1, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine.

[0077] For the case where the workpiece to be measured is facing left, the measurement and calculation process is as follows: Figure 4 , Figure 6 , Figure 8 and Fig.10 As shown, the adjustment angle θ2 is calculated by formula (2), and the horizontality of the workpiece to be measured along the X-axis is adjusted according to the angle θ2, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine; the same method is used to complete the adjustment along the Y-axis.

[0078] The method of the present invention is not limited to measuring circular holes or truncated cones in the embodiments, but is also applicable to holes or bosses with rectangular or other shapes in cross section.

Claims

1. A method for adjusting the posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine, wherein the deep micro-hole workpiece is placed in the three-dimensional coordinate measuring machine as a workpiece to be measured, and a moving stylus is used to detect the cylindrical hole in the deep micro-hole workpiece to measure the roundness of the cylindrical hole; the three-dimensional coordinate measuring machine has a vertical Z axis and a horizontal XOY plane; the stylus has a stylus ball fixed at the lower end of a stylus rod, and the central axis of the stylus is parallel to the Z axis of the three-dimensional coordinate measuring machine; the method is characterized in that: The method for adjusting the posture of the deep micro-hole workpiece in the three-dimensional coordinate measuring machine is: by adjusting the horizontality of the deep micro-hole workpiece along the X-axis and / or the Y-axis, the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine.

2. The method for adjusting the position and posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine according to claim 1, characterized in that Proceed as follows: Step 1, guide the measuring needle to the measuring position of the workpiece to be measured, record the measuring position as the initial position O, and the coordinates of the initial position O are marked as O (x0, y0, z0); Step 2: Move the probe from the initial position O in the positive direction along the X-axis until the probe touches the workpiece and generates a trigger signal to stop moving. The probe stops at position A, and the coordinates of position A are marked as A(x1, y0, z0); Step 3, move the probe from position A along the negative direction of the X axis until the probe touches the workpiece to be measured and generates a trigger signal and stops moving. The probe stops at position B, and the coordinates of position B are marked as B (x2, y0, z0); Step 4: Move the probe from position B in the positive direction along the X-axis until the probe returns to the initial position O and is controlled to stop moving; Step 5: Move the probe vertically downward along the Z direction from the initial position O for a certain distance and stop moving when it reaches position C. The coordinates of position C are marked as C (x0, y0, z1); Step 6, move the probe from position C along the positive direction of the X axis until the probe is controlled to stop moving due to the trigger signal generated by the workpiece to be measured, and the probe stops at position D, and the coordinates of position D are marked as D (x3, y0, z1); Step 7, move the probe from position D along the negative direction of the X axis until the probe is controlled to stop moving due to the trigger signal generated by the workpiece to be measured, and the probe stops at position E, and the coordinates of position E are marked as E (x4, y0, z1); Step 8: Record the line connecting position A and position D as straight line l AD , and the line connecting position B and position E is recorded as straight line l PE ; Then we have: Line l AD The slope k AD for: Straight line BE The slope k BE for: If the values ​​of (x3-x1) and (x4-x2) are both zero, it indicates that the posture of the deep micro-hole workpiece meets the requirements, and the posture adjustment is ended; If one of the values ​​of (x3-x1) and (x4-x2) is zero and the other is not zero, it is judged that the posture of the deep micro-hole workpiece does not meet the requirements. The position adjustment is achieved by adjusting the horizontality of the deep micro-hole workpiece along the X-axis so that the center axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine.

3. The method for adjusting the position and posture of a deep micro-hole workpiece in a three-dimensional coordinate measuring machine according to claim 2 is characterized in that: According to the calculated adjustment angle θ1, accurate posture adjustment is achieved as follows: If the value of (x3-x1) is not zero, the value of (x4-x2) is zero, and the adjustment angle θ1 is calculated by formula (1): Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ1, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine; If the value of (x3-x1) is zero and the value of (x4-x2) is not zero, the adjustment angle θ2 is calculated by formula (2): Adjust the horizontality of the workpiece to be measured along the X-axis according to the angle of θ2, so that the central axis of the cylindrical hole in the deep micro-hole workpiece is parallel to the Z-axis of the three-dimensional coordinate measuring machine; The same method is used to complete the adjustment on the Y axis.

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