Internal thread hole assembly and adjustment reference measuring device and its measuring method

Abstract

This invention provides a reference measuring device and method for assembling and adjusting internal threaded holes. The measuring device includes a reference plate and a reference post, which are fixedly connected. At least two reference holes and one mounting hole are formed on the reference plate. The mounting hole is not located on the line connecting any two reference holes. The reference post passes through the mounting hole and is fixedly connected to the reference plate. Positioning holes are formed at both ends of the reference post, and an external thread for mating with the internal threaded hole to be measured is formed at the end of the reference post that does not pass through the mounting hole. This invention allows for the accurate, rapid, and convenient determination of the orientation vector of the central axis of the internal threaded hole and the coordinates of the center point of the pitch diameter, thereby completely determining the spatial orientation of the internal threaded hole and significantly improving the assembly and adjustment accuracy and efficiency of assemblies containing internal threaded holes.

Description

Technical Field

[0001] This invention relates to the field of optical and precision mechanical assembly and adjustment technology, and in particular to a reference measuring device and method for internal thread hole assembly and adjustment. Background Technology

[0002] For precision optical systems in fields such as aerospace, remote sensing, and astronomy, in addition to manufacturing high-precision optical and mechanical components, it is also necessary to use effective methods to assemble and adjust each optical and mechanical component to its theoretical pose so that the overall system achieves the expected design specifications. Therefore, the accuracy and efficiency of the assembly and adjustment methods directly determine the achievement of the entire system's specifications and the development cycle.

[0003] In the assembly and adjustment of high-precision optomechanical systems, it is usually necessary to measure the spatial pose relationship between the reference coordinate systems of various components, and then adjust each component to its theoretical position through a precision adjustment mechanism to complete the assembly. Existing measurement schemes for the assembly and adjustment reference of internal threaded holes have significant errors. The center point of the pitch diameter at the entrance of the internal threaded hole is significantly affected by the machining accuracy of the threaded hole in that local area. Once a machining error occurs in the coaxiality of the local thread at the entrance of the threaded hole, causing the minor diameter and major diameter to be misaligned, it will directly lead to a deviation in the coordinates of the center point of the pitch diameter of the internal threaded hole. Secondly, given the small internal space of the internal threaded hole, most measuring equipment cannot enter. Existing technical solutions directly assume the central axis of the internal threaded hole is the normal to the reference plane at the entrance. However, in reality, due to limitations in the machining process, the central axis of the threaded hole is not perpendicular to the reference plane, but has an angle, which in turn leads to measurement errors in the assembly and adjustment reference of the threaded hole. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and to propose a reference measuring device and method for internal threaded hole assembly, which can significantly improve the assembly accuracy and efficiency of assemblies containing internal threaded holes.

[0005] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0006] The internal thread hole adjustment reference measuring device provided by the present invention includes a reference plate and a reference column. The reference plate and the reference column are fixedly connected. At least two reference holes and one mounting hole are provided on the reference plate. The mounting hole is not on the line connecting any two reference holes. The reference column passes through the mounting hole and is fixedly connected to the reference plate. Positioning holes are provided at both ends of the reference column. An external thread for mating with the internal thread hole to be measured is provided at the end of the reference column that does not pass through the mounting hole.

[0007] Preferably, the reference plate is polygonal in shape.

[0008] The method for measuring the adjustment reference of an internal threaded hole provided by this invention includes the following steps:

[0009] S1. Under the same coordinate system, use measuring instruments to measure the spatial coordinates of the center points of the reference hole and the positioning hole to obtain the first measurement data;

[0010] S2. Based on the first measurement data, establish coordinate system A, connect the center points of the positioning holes at both ends of the reference column with a straight line, and obtain the direction cosine of the straight line in coordinate system A.

[0011] S3. Adjust the reference measuring device for the internal thread hole by connecting it with the internal thread hole to be measured through the external thread until the external thread and the internal thread hole to be measured no longer move relative to each other.

[0012] S4. Using measuring instruments, measure the spatial coordinates of the center points of the reference hole, the exposed positioning hole, and the reference surface at the entrance of the internal thread hole to be measured, and obtain the second measurement data.

[0013] S5. Using the second measurement data, establish coordinate system A in the same way as step S2, and obtain the equation of the reference surface at the entrance of the internal thread hole and the direction cosine of the central axis of the internal thread hole under coordinate system A. Then, obtain the coordinates of the intersection of the equation of the reference surface at the entrance of the internal thread hole and the central axis of the internal thread hole, and use it as the coordinates of the center point of the inner diameter of the internal thread hole. Thus, all the assembly and adjustment references of the internal thread hole to be measured are obtained.

[0014] Preferably, when the measuring instrument is a laser tracker, the method for measuring the mounting reference of the internal threaded hole includes the following steps:

[0015] S1. Fix the internal thread hole mounting reference measuring device on the platform, and use a laser tracker to measure the first laser tracker target ball, the second laser tracker target ball, the third laser tracker target ball, and the fourth laser tracker target ball, and record the spatial coordinates of the center of the four laser tracker target balls; wherein, the first laser tracker target ball and the fourth laser tracker target ball are respectively installed on the positioning holes at both ends of the reference column, the second laser tracker target ball is installed on the reference hole closer to the first laser tracker target ball, and the third laser tracker target ball is installed on the reference hole farther from the first laser tracker target ball;

[0016] S2. Let the line connecting the first laser tracker target ball and the second laser tracker target ball be the X-axis, and the line connecting the first laser tracker target ball and the third laser tracker target ball be the Y-axis. With the center of the first laser tracker target ball, the second laser tracker target ball, or the third laser tracker target ball as the origin, after correcting the non-orthogonality error between the X-axis and the Y-axis, establish coordinate system A.

[0017] S3. Connect the centers of the first laser tracker target ball and the fourth laser tracker target ball with a straight line L to obtain the direction cosine of the straight line L in the coordinate system;

[0018] S4. Remove the target ball of the fourth laser tracker, and mate the internal thread hole mounting reference measuring device with the internal thread hole to be measured until the internal thread hole mounting reference measuring device and the internal thread hole to be measured do not move relative to each other.

[0019] S5. Measure the spatial coordinates of the first laser tracker target ball, the second laser tracker target ball, and the third laser tracker target ball using a laser tracker, and measure at least 3 points on the reference surface at the entrance of the internal thread hole to obtain the reference surface at the entrance of the internal thread hole to be measured by fitting.

[0020] S6. Construct coordinate system A using the spatial coordinates from step S5 in the same way as step S2. This will give you the direction cosine of the straight line L, which is the center axis of the internal thread hole to be measured. Intersect the straight line L with the reference plane at the entrance of the internal thread hole to get the spatial coordinates of the intersection point D. This is the coordinate of the center point of the middle diameter of the internal thread hole, thus obtaining the assembly and adjustment reference of the internal thread hole to be measured.

[0021] The present invention can achieve the following technical effects: the orientation vector of the central axis of the internal threaded hole and the coordinates of the center point of the pitch diameter can be determined accurately, quickly and conveniently, thereby completely determining the spatial pose of the internal threaded hole and greatly improving the assembly accuracy and efficiency of the assembly of the internal threaded hole. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the assembly structure of the internal thread hole adjustment reference measuring device provided in an embodiment of the present invention.

[0023] Figure 2 This is a flowchart of a method for measuring the reference of an internal threaded hole according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the assembly structure of a laser tracker embodiment provided according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the assembly structure of the mating internal threaded hole to be tested according to an embodiment of the present invention.

[0026] The reference numerals in the attached drawings include: reference plate 1, reference column 2, external thread 2-1, positioning hole 2-2, reference hole 3, first laser tracker target ball 4, second laser tracker target ball 5, third laser tracker target ball 6, fourth laser tracker target ball 7, reference surface at the entrance of the internal thread hole to be tested 8, and internal thread hole to be tested 9. Detailed Implementation

[0027] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0029] Figure 1 The assembly structure of the internal thread hole adjustment reference measuring device provided in an embodiment of the present invention is shown.

[0030] like Figure 1 As shown, the internal thread hole adjustment reference measuring device provided in this embodiment of the invention includes a reference plate 1 and a reference column 2. The reference plate 1 and the reference column 2 are fixedly connected. It is necessary to ensure that the reference column 2 and the reference plate 1 remain relatively stationary and that their positions no longer change.

[0031] At least two reference holes 3 and one mounting hole are provided on the reference plate 1. The mounting hole is not on the line connecting any two reference holes 3. The reference post 2 is installed on the reference plate 1 through the mounting hole. Positioning holes 2-2 are provided at both ends of the reference post 2. Through precision machining, it is ensured that the center point of the positioning hole 2-2 is located on the central axis of the reference post 2, and the line connecting the centers of the two positioning holes 2-2 is collinear with the central axis of the reference post. The end of the reference post 2 that does not pass through the mounting hole has an external thread 2-1 for mating with the internal thread hole to be measured.

[0032] The reference plate 1 is polygonal in shape, and preferably triangular in this embodiment of the invention.

[0033] In this embodiment of the invention, the number of reference holes 3 is preferably two. The positioning hole 2-2 that passes through one end of the mounting hole on the reference post 2 is connected to the two reference holes 3 respectively, and the included angle between the two connecting lines is 90°.

[0034] Figure 2 The flowchart of the internal thread hole assembly and adjustment reference measurement method provided by the embodiment of the present invention is shown.

[0035] like Figure 2 As shown in the figure, the measurement method based on the internal thread hole adjustment reference measuring device provided in this embodiment of the invention includes the following steps:

[0036] S1. Under the same coordinate system, use a measuring instrument to measure the spatial coordinates of the center point of the reference hole 3 and the positioning hole 2-2 to obtain the first measurement data.

[0037] S2. Based on the first measurement data, establish coordinate system A, connect the center points of the positioning holes 2-2 at both ends of the reference column 2 with a straight line, and obtain the direction cosine of the straight line in the coordinate system.

[0038] S3. Connect the internal thread hole to the reference measuring device through the external thread 2-1 and mate it with the internal thread hole to be measured until the external thread and the internal thread to be measured no longer move relative to each other.

[0039] S4. Using measuring instruments, measure the spatial coordinates of the center point of the reference hole 3, the exposed positioning hole 2-2, and the reference surface 8 at the entrance of the internal thread hole to be measured, and obtain the second measurement data.

[0040] S5. Using the measurement results from S4, establish a measurement coordinate system A again in the same way as S2, and obtain the equation of the datum plane 8 at the entrance of the internal thread hole under this coordinate system. Obtain the direction cosine of the central axis of the internal thread hole from the results of S2. Calculate the coordinates of the intersection point of the datum plane equation and the direction cosine. This is the coordinate of the center point of the mean diameter of the internal thread hole. Thus, all the assembly and adjustment datums for the internal thread hole to be measured are obtained.

[0041] Figure 3 The assembly structure of a laser tracker embodiment provided in this invention is shown.

[0042] like Figure 3 As shown, the above measuring instrument uses a laser tracker. Laser tracker target balls are installed at the reference hole 3 and the positioning hole 2-2 respectively. The laser tracker target ball contains a corner cube prism, which can return the incident light along 180°.

[0043] Figure 4 The assembly structure for mating with the internal threaded hole to be tested, provided by an embodiment of the present invention, is shown.

[0044] like Figure 4 As shown in the embodiment, the measurement method based on the internal thread hole adjustment reference measuring device includes the following steps:

[0045] S1. Fix the internal thread hole mounting reference measuring device on the platform. Use a laser tracker to measure the first laser tracker target ball 4, the second laser tracker target ball 5, the third laser tracker target ball 6, and the fourth laser tracker target ball 7. Record the spatial coordinates of the center of the four laser tracker target balls. The first laser tracker target ball 4 and the fourth laser tracker target ball 7 are respectively installed on the positioning holes 2-1 at both ends of the reference column 2. The second laser tracker target ball 5 is installed on the reference hole 3 which is closer to the first laser tracker target ball 4. The third laser tracker target ball 6 is installed on the reference hole 3 which is farther away from the first laser tracker target ball 4.

[0046] S2. Let the line connecting the first laser tracker target ball 4 and the second laser tracker target ball 5 be the X-axis, and the line connecting the first laser tracker target ball 4 and the third laser tracker target ball 6 be the Y-axis. With the center of one of the laser tracker target balls (first laser tracker target ball 4, second laser tracker target ball 5, or third laser tracker target ball 6) as the origin, establish coordinate system A after correcting the non-orthogonality error between the X-axis and the Y-axis.

[0047] S3. Connect the centers of the first laser tracker target ball 4 and the fourth laser tracker target ball 7 with a straight line L to obtain the direction cosine of the straight line L in the coordinate system.

[0048] S4. Remove the target ball 7 of the fourth laser tracker, and fit the internal thread hole mounting reference measuring device tightly with the internal thread hole 9 to be measured until the relative position of the internal thread hole 9 to be measured and the internal thread hole 9 to be measured remains unchanged.

[0049] S5. Measure the spatial coordinates of the first laser tracker target ball 4, the second laser tracker target ball 5, and the third laser tracker target ball 6 using a laser tracker. Measure at least 3 points on the reference surface 8 at the entrance of the internal thread hole 9 to be tested, and fit the reference surface 8 at the entrance of the internal thread hole to be tested.

[0050] S6. Using the measurement data from step S5, construct coordinate system A in the same manner as step S2 to obtain the direction cosine of the straight line L of the central axis of the internal thread hole 9 to be measured. Intersect the straight line L with the reference plane 8 at the entrance of the internal thread hole to obtain the spatial coordinates of the intersection point D. This is the coordinate of the center point of the mean diameter of the internal thread hole 9 to be measured, thereby obtaining the assembly and adjustment reference of the internal thread hole 9 to be measured.

[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0052] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0053] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method of measuring a counterbore reference, using a counterbore reference measuring device, characterized in that, The method comprises the following steps: The inner threaded hole installation and adjustment reference measurement device comprises a reference plate (1) and a reference column (2), the reference plate (1) is fixedly connected with the reference column (2), at least two reference holes (3) and one mounting hole are formed in the reference plate (1), the mounting hole is not on the connecting line between any two reference holes (3), the reference column (2) penetrates through the mounting hole and is fixedly connected with the reference plate (1), positioning holes (2-2) are formed at two ends of the reference column (2), and external threads (2-1) for cooperating with the to-be-measured inner threaded hole are formed at one end of the reference column (2) which does not penetrate through the mounting hole S1, in the same coordinate system, the spatial coordinates of the center points of the reference holes (3) and the positioning holes (2-2) are measured by using a measuring instrument, and first measurement data is obtained; S2, by means of the first measurement data, a coordinate system A is established, the center points of the positioning holes (2-2) at two ends of the reference column (2) are connected into a straight line, and the direction cosine of the straight line in the coordinate system A is obtained; S3, the inner threaded hole installation and adjustment reference measurement device is matched with the to-be-measured inner threaded hole through the external threads (2-1), until the external threads (2-1) no longer move relative to the to-be-measured inner threaded hole; S4, the spatial coordinates of the center points of the reference holes (3) and the positioning holes (2-2) exposed outside and the reference surface (8) at the entrance of the to-be-measured inner threaded hole are measured by using a measuring instrument, and second measurement data is obtained; S5, by means of the second measurement data, the coordinate system A is established in the same way as in step S2, the reference surface equation at the entrance of the inner threaded hole and the direction cosine of the central axis of the inner threaded hole are obtained in the coordinate system A, and then the coordinates of the intersection point of the reference surface equation at the entrance of the inner threaded hole and the central axis of the inner threaded hole are obtained as the center point coordinates of the inner threaded hole pitch circle, thus obtaining all installation and adjustment references of the to-be-measured inner threaded hole.

2. The method of aligning a reference measurement of a female threaded hole of claim 1, wherein, When the measuring instrument is a laser tracker, the inner threaded hole installation and adjustment reference measurement method comprises the following steps: S1, the inner threaded hole installation and adjustment reference measurement device is fixed on a platform, first, second, third and fourth laser tracker target balls (4), (5), (6) and (7) are measured by using a laser tracker, and the spatial coordinates of the centers of the four laser tracker target balls are recorded; wherein the first laser tracker target ball (4) and the fourth laser tracker target ball (7) are respectively installed on the positioning holes (2-2) at two ends of the reference column (2), the second laser tracker target ball (5) is installed on the reference hole (3) close to the first laser tracker target ball (4), and the third laser tracker target ball (6) is installed on the reference hole (3) far away from the first laser tracker target ball (4); S2, set the first laser tracker target ball (4) and the second laser tracker target ball (5) line as the X axis, the first laser tracker target ball (4) and the third laser tracker target ball (6) line as the Y axis, with the first laser tracker target ball (4), the second laser tracker target ball (5) or the third laser tracker target ball (6) as the origin, correct the non-orthogonal error of the X axis and the Y axis, and establish a coordinate system A; S3, the first laser tracker target ball (4) and the fourth laser tracker target ball (7) are connected into a straight line L, and the direction cosine of the straight line L in the coordinate system is obtained; S4, the fourth laser tracker target ball (7) is removed, the internal thread hole adjustment reference measurement device is matched with the to-be-measured internal thread hole until the internal thread hole adjustment reference measurement device and the to-be-measured internal thread hole do not move relative to each other; S5, the space coordinates of the first laser tracker target ball (4), the second laser tracker target ball (5) and the third laser tracker target ball (6) are measured by the laser tracker, and at least three points on the reference surface at the entrance of the internal thread hole are measured, and the reference surface (8) at the entrance of the to-be-measured internal thread hole is fitted; S6, the space coordinates of step S5 are constructed in the same way as step S2 to obtain the direction cosine of the straight line L of the center axis of the to-be-measured internal thread hole, the straight line L intersects with the reference surface at the entrance of the internal thread hole to obtain the space coordinates of the intersection point D, which is the center point coordinates of the pitch circle of the internal thread hole, so that the adjustment reference of the to-be-measured internal thread hole is measured.

3. The method of aligning a reference measurement of a female threaded hole of claim 1, wherein, The shape of the reference plate (1) is polygonal.

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