Measuring tool and concealed reference point measuring system
By designing the measuring tool, using the method of articulating the ball with the reference ball, the measuring tool is rotated multiple times to calculate the coordinates of the hidden reference point, which solves the problem of inconvenient measurement of hidden reference points and achieves efficient and low-intensity measurement effects.
Patent Information
- Application Number
- CN202422030402.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-08-21
AI Technical Summary
On industrial production lines, it is difficult to measure the coordinates of obscured hidden reference points. The prior art requires multiple handling of measurement equipment, which is very labor-intensive and time-consuming.
A measuring tool is designed, including a connecting rod, a target ball and a sphere. The sphere is articulated with the reference ball seat ball. By rotating the measuring tool multiple times, the target ball is placed within the measurable range of the laser tracker, and the coordinates of the hidden reference point are calculated using the laser tracker to measure the coordinates of the target ball.
It reduces the labor intensity of the measuring staff, reduces the need for handling laser trackers, improves measurement efficiency, and can complete coordinate measurement of hidden reference points within three minutes.
Smart Images
Figure CN223243559U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of measuring tooling, and in particular relates to a measuring tooling and a concealed reference point measurement system. Background Art
[0002] On some industrial production lines, such as pickling lines, twenty-high mill rolling lines, continuous annealing lines, automated production lines, etc., it is usually necessary to measure the position of the reference points on each device in order to correct the spatial position of the equipment and ensure the stable operation of each device on the industrial production line.
[0003] Measuring obscured reference points, that is, the reference points are blocked by some structures on the equipment or other equipment, and the measuring instrument cannot directly measure the coordinates of the reference points, has always been a difficult problem in industrial production line measurement.
[0004] In the related art, the method of measuring public point transfer stations is adopted to measure hidden benchmark points. This method requires surveyors to carry and move the measuring equipment many times. The surveyors have high labor intensity and take a long time. It usually takes 30 minutes to measure the coordinates of a hidden benchmark point. Utility Model Content
[0005] The present application aims to at least to some extent solve the technical problem of inconvenient coordinate measurement of hidden reference points in the related art. To this end, the present application provides a measuring tool and a hidden reference point measurement system.
[0006] In a first aspect, an embodiment of the present application provides a measuring tool, comprising:
[0007] A connecting rod having a first end and a second end disposed opposite to each other along a length direction of the connecting rod;
[0008] a target ball mounted on the first end of the connecting rod;
[0009] A sphere is mounted on the second end of the connecting rod, and the sphere is used for articulating with a reference ball seat, wherein the reference ball seat is mounted on the device to be detected.
[0010] In some embodiments, the measuring tool further includes a target seat connected to the target ball and the first end of the connecting rod, and the target ball is rotatably connected to the target seat.
[0011] In some embodiments, the target seat is adsorbed on the connecting rod by magnetic force; a spherical groove is provided on the target seat, the diameter of the spherical groove is consistent with the diameter of the target ball, and the target ball is adsorbed on the target seat by magnetic force and is partially located in the spherical groove.
[0012] In some embodiments, the target base is further bonded to the connecting rod.
[0013] In some embodiments, the measuring tool further includes a magnet, which is fixedly connected to the second end of the connecting rod and contacts the sphere. Under the action of the magnet, the sphere has magnetism.
[0014] In some embodiments, the connecting rod and the sphere are connected by a first connecting member and a second connecting member; the first connecting member is fixedly connected to the second end of the connecting rod, the second connecting member is fixedly connected to the sphere, and the first connecting member and the second connecting member are detachably connected.
[0015] In some embodiments, the first connecting member and the second connecting member are threadedly connected.
[0016] In some embodiments, the connecting rod includes a first rod body and a second rod body connected to each other, an end of the first rod body away from the second rod body is a first end, and an end of the second rod body away from the first rod body is a second end;
[0017] The first rod and the second rod are capable of relative movement, so that the total length of the first rod and the second rod can be changed.
[0018] In a second aspect, an embodiment of the present application further provides a hidden reference point measurement system, comprising:
[0019] A reference ball seat, the reference ball seat being used for fixed connection with the device to be detected, the reference ball seat having a spherical groove;
[0020] The measuring fixture described in the first aspect above, wherein the diameter of the sphere of the measuring fixture is the same as the diameter of the spherical groove, and the sphere is partially located in the spherical groove of the reference ball seat to be spherically hinged with the reference ball seat;
[0021] A laser tracker is used to detect the coordinates of the target sphere.
[0022] In some embodiments, the sphere is attracted to the reference spherical seat by magnetic force.
[0023] The utility model has at least the following beneficial effects:
[0024] The measuring fixture of this application includes a connecting rod, a target ball, and a sphere. During measurement, the sphere is articulated with a reference spherical seat mounted on the device to be tested. After the sphere is mounted on the reference spherical seat, the center of the sphere coincides with the hidden reference point. The coordinates of the sphere center are the coordinates of the hidden reference point.
[0025] Since the sphere is hinged to the reference ball seat, when the measuring fixture of this application rotates, the coordinates of the center of the sphere remain unchanged, and the target ball can be rotated to an unobstructed position and detected by the laser tracker.
[0026] After the present application is designed in this way, the operator rotates the measuring tool of the present application around the center of the sphere multiple times, so that the target ball can be located at multiple different positions. The laser tracker measures the coordinates of each position of the target ball, and then fits the coordinates of the target ball onto a ball through SA and other software. The center of the fitted ball is the center of the sphere, and the coordinates of the center are the coordinates of the hidden reference point.
[0027] After the present application is designed in this way, when measuring the coordinates of hidden reference points, the operator no longer needs to set up a public point transfer station, and only needs to rotate the measuring tool of the present application multiple times. The installation position of the laser tracker does not need to be changed, and the number of measurement personnel required is relatively low. It facilitates the measurement of hidden reference points, can accurately measure the coordinates of hidden reference points, and has a high measurement efficiency. After using the measuring tool of the present application, the coordinates of the hidden reference points can be measured in about three minutes. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0029] Figure 1 A schematic diagram of a measuring tool in some embodiments of the present application is shown.
[0030] Figure 2 Schematic diagrams of measuring tools in other embodiments of the present application are shown.
[0031] Figure 3 A schematic diagram of the structure showing the connection between the connecting rod and the sphere via the first connecting member and the second connecting member is shown.
[0032] Figure 4 A schematic diagram of a hidden reference point measurement system in some embodiments of the present application is shown.
[0033] Figure numerals: 100 - measuring tool, 110 - connecting rod, 111 - first rod body, 112 - second rod body, 120 - target ball, 130 - sphere, 140 - target seat, 150 - magnet, 160 - first connecting piece, 170 - second connecting piece, 200 - reference ball seat, 210 - spherical groove, 300 - laser tracker, 400 - equipment to be tested, 1000 - hidden reference point measurement system. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0035] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0036] In this utility model, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.
[0037] In addition, in this utility model, the descriptions of "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.
[0038] On some industrial production lines, such as pickling lines, twenty-high mill rolling lines, continuous annealing lines, automated production lines, etc., it is usually necessary to measure the position of the reference points on each device in order to correct the spatial position of the equipment and ensure the stable operation of each device on the industrial production line.
[0039] Measuring obscured reference points, that is, the reference points are blocked by some structures on the equipment or other equipment, and the measuring instrument cannot directly measure the coordinates of the reference points, has always been a difficult problem in industrial production line measurement.
[0040] In the related art, the method of measuring public point transfer stations is adopted to measure hidden benchmark points. This method requires surveyors to carry and move the measuring equipment many times. The surveyors have high labor intensity and take a long time. It usually takes 30 minutes to measure the coordinates of a hidden benchmark point.
[0041] In the related art, there is a technical problem that it is inconvenient to measure hidden reference points. The embodiment of the present application provides a measuring tool that can at least to some extent solve the technical problem of the inconvenience of measuring hidden reference points.
[0042] The present application is described below with reference to specific embodiments and with reference to the accompanying drawings:
[0043] like Figure 1 As shown, a measuring tool 100 (hereinafter referred to as measuring tool 100) for cooperating with a laser tracker 300 to measure the coordinates of a hidden reference point includes a connecting rod 110, a target ball 120 and a sphere 130; the target ball 120 is installed at a first end of the connecting rod 110; the sphere 130 is installed at a second end of the connecting rod 110, and the sphere 130 is used for ball-jointed connection with a reference ball seat 200, wherein the reference ball seat 200 is installed on the device to be detected 400.
[0044] Please refer to Figure 1 As shown, in Figure 1 In the embodiment, the upper end of the connecting rod 110 is the first end, and the lower end of the connecting rod 110 is the second end.
[0045] You can refer to Figure 4 As shown, it should be noted that the reference spherical seat 200 is fixedly connected to the device to be tested 400 and has a spherical groove 210 on the reference spherical seat 200. The center of the spherical groove 210 is the reference point of the device to be tested 400. The diameter of the sphere 130 should be the same as the diameter of the spherical groove 210 to ensure that when the sphere 130 is located in the spherical groove 210 and fits into the spherical groove 210, the center of the sphere 130 coincides with the center of the spherical groove 210. The coordinates of the center of the sphere 130 are the coordinates of the reference point.
[0046] The sphere 130 is spherically hinged to the reference ball seat 200 so that the sphere 130 can rotate around the center of the sphere to ensure that when the measuring fixture 100 rotates, the position of the center of the sphere 130 remains unchanged and always coincides with the center of the spherical groove 210, that is, always coincides with the reference point.
[0047] The principle of the measuring fixture 100 of the present application is as follows: after the sphere 130 is spherically articulated with the reference sphere seat 200, the measuring fixture 100 is rotated multiple times so that the target sphere 120 is positioned at at least three locations within the measurement range of the laser tracker 300. The laser tracker 300 then measures the coordinates of each position of the target sphere 120. Ultimately, the coordinates of the center of the sphere 130 are calculated from these position coordinates of the target sphere 120, thereby obtaining the coordinates of the obscured reference point. In other words, when using the measuring fixture 100 of the present application, the coordinates of the obscured reference point are not directly measured, but are instead calculated from multiple sets of target sphere 120 position coordinates.
[0048] With this design, when measuring the coordinates of hidden reference points, there is no need to set up a common point transfer station, the position of the laser tracker 300 does not need to be changed, and the operator does not need to carry or move the laser tracker 300 for measurement. The operator only needs to rotate the tooling so that the target sphere 120 can be located in at least three different positions within the measurement range of the laser tracker 300. Since the laser tracker 300 and other instruments do not need to be carried, the number of measurement personnel required is relatively low, and the labor intensity of the measurement personnel is reduced. After using the tooling of the present application, the operator can measure the coordinates of the hidden reference point in about three minutes, which has high measurement efficiency and facilitates the measurement of the coordinates of the obscured reference point.
[0049] The structure of the connecting rod 110 is not limited in this application. In some embodiments, the connecting rod 110 is hollow and has a circular cross-section. In some embodiments, the measuring tool 100 further includes a target base 140, which is connected to the target sphere 120 and the first end of the connecting rod 110. The target sphere 120 is rotatably connected to the target base 140.
[0050] In these embodiments, the target sphere 120 is rotatably connected to the target base 140, which is fixedly connected to the first end of the connecting rod 110. The target sphere 120 is rotatably connected to the target base 140, so that the target sphere 120 can rotate around the target base 140, so that the mirror surface of the target sphere 120 can face different directions to facilitate measurement by the laser tracker 300.
[0051] It should be noted that the structures of the target ball 120 and the target base 140 are diverse, and the specific structures of the target ball 120 and the target base 140 are known to those skilled in the art. In addition, the methods of rotational connection between the target ball 120 and the target base 140 are also diverse and known to those skilled in the art, and will not be elaborated here.
[0052] In some embodiments, the target seat 140 is magnetically adsorbed on the connecting rod 110; a spherical groove is provided on the target seat 140, the diameter of the spherical groove is consistent with the diameter of the target ball 120, and the target ball 120 is magnetically adsorbed on the target seat 140 and partially located in the spherical groove.
[0053] With this design, when the target ball 120 is placed in the spherical groove, the target base 140 absorbs the target ball 120, and the spherical surface of the target ball 120 contacts the inner wall of the spherical groove, allowing the target ball 120 to rotate within the spherical groove, thereby achieving a rotational connection between the target ball 120 and the target base 140. It should be noted that the target base 140 should be magnetic, and the target ball 120 and the connecting rod 110 should be made of a metal material such as iron, nickel, or cobalt to ensure that the target ball 120 can be absorbed on the target base 140, and the target base 140 can be absorbed on the connecting rod 110.
[0054] In some embodiments, the target holder 140 is further bonded to the connecting rod 110 .
[0055] The target base 140 and the connecting rod 110 are bonded together by glue to improve the stability of the connection between the target base 140 and the connecting rod 110 .
[0056] In some embodiments, the measuring tool 100 further includes a magnet 150 . The magnet 150 is fixedly connected to the second end of the connecting rod 110 and contacts the sphere 130 . Under the action of the magnet 150 , the sphere 130 has magnetism.
[0057] It should be noted that the sphere 130 should be made of a metal material such as iron, nickel, or cobalt. Under the action of the magnet 150, the sphere 130 will be magnetized by the magnet 150, so that the sphere 130 acquires magnetism. In these embodiments, the material of the reference sphere seat 200 can be made of a metal material such as iron, nickel, or cobalt, so that the sphere 130 can be adsorbed on the reference sphere seat 200 and partially located in the spherical groove 210 of the reference sphere seat 200. Under the action of the magnetic force, the entire measuring tool 100 can be fixed to the reference sphere seat 200. In this way, the sphere 130 can rotate along the center of the sphere in the spherical groove 210, and under the action of the magnetic force, the sphere 130 fits the spherical groove 210.
[0058] like Figure 3 As shown, in some embodiments, the connecting rod 110 and the sphere 130 are connected by a first connecting member 160 and a second connecting member 170; the first connecting member 160 is fixedly connected to the second end of the connecting rod 110, and the second connecting member 170 is fixedly connected to the sphere 130, and the first connecting member 160 and the second connecting member 170 are detachably connected.
[0059] The first connector 160 is fixedly connected to the second end of the connecting rod 110 to ensure that after the sphere 130 is connected to the first connector 160 via the second connector 170, the sphere 130 is located at the second end of the connecting rod 110. The first connector 160 and the second connector 170 can be detachably connected together by threaded connection, snap connection, bonding, etc., which are not limited in this application. The first connector 160 and the second connector 170 are detachably connected, so that the second connector 170 and the sphere 130 can be removed from the first connector 160, so that the sphere 130 and the second connector 170 can be replaced, so that the measuring tool 100 can be installed with spheres 130 of different diameters, suitable for reference ball seats 200 of different specifications.
[0060] The first connector 160 and the connecting rod 110 can be fixedly connected in various ways, as can the sphere 130 and the second connector 170, such as by welding, bonding, or clamping. In some embodiments, the first connector 160 and the second connector 170 are threadedly connected. With this design, rotating the sphere 130 can connect or disconnect the first connector 160 and the second connector 170, facilitating the connection and disconnection of the first connector 160 and the second connector 170.
[0061] In some embodiments, a threaded hole is provided on the second connecting member 170 , and an external thread is provided on the first connecting member 160 . The first connecting member 160 and the second connecting member 170 are threadedly matched with each other through the external thread and the threaded hole.
[0062] like Figure 2 As shown, in some embodiments, the connecting rod 110 includes a first rod body 111 and a second rod body 112 connected to each other, the end of the first rod body 111 away from the second rod body 112 is a first end, and the end of the second rod body 112 away from the first rod body 111 is a second end; the first rod body 111 and the second rod body 112 can move relative to each other so that the total length of the first rod body 111 and the second rod body 112 can be changed.
[0063] The total length of the first rod 111 and the second rod 112 can be changed so that the measuring tool 100 of the present application can be used in different scenarios. The connection between the first rod 111 and the second rod 112 is diverse. In some embodiments, the first rod 111 and the second rod 112 are arranged in parallel, and the first rod 111 is slidably connected to the second rod 112 along the length direction of the second rod 112 so that the total length of the first rod 111 and the second rod 112 can be changed. It should be noted that if the first rod 111 and the second rod 112 are slidably connected, a locking member should be provided on the first rod 111 or the second rod 112 so that after the first rod 111 slides to a certain position, the first rod 111 can be fixed to the second rod 112 under the action of the locking member so that the total length of the first rod 111 and the second rod 112 can remain unchanged. The locking member can be a screw or the like. The first rod 111 and the second rod 112 can be connected by threads. For example, a threaded hole is provided at one end of the second rod 112, and an external thread is provided on the peripheral wall of the first rod 111. The first rod 111 is located in the threaded hole and is threadedly connected to the threaded hole. By rotating the first rod 111, the total length of the first rod 111 and the second rod 112 can be changed. Figure 4 As shown, based on the same inventive concept, an embodiment of the present application further provides a concealed reference point measurement system 1000, comprising a reference spherical seat 200, a laser tracker 300, and the aforementioned measuring fixture 100. The reference spherical seat 200 is used for fixed connection with the device to be detected 400, and the reference spherical seat 200 has a spherical groove 210; the diameter of the sphere 130 of the measuring fixture 100 is the same as the diameter of the spherical groove 210, and the sphere 130 is partially located in the spherical groove 210 of the reference spherical seat 200, so as to be spherically articulated with the reference spherical seat 200; the laser tracker 300 is used to detect the coordinates of the target sphere 120.
[0064] The reference spherical seat 200 is fixedly connected to the device to be inspected 400. The center of the spherical recess 210 of the reference spherical seat 200 serves as the reference point of the device to be inspected 400. Since the diameter of the sphere 130 is the same as the diameter of the spherical recess 210, the center of the sphere 130 coincides with the reference point after the sphere 130 is positioned within the spherical recess 210. In other words, the coordinates of the center of the sphere 130 are the coordinates of the reference point. The structure of the laser tracker 300 is diverse and is not limited here.
[0065] Since the hidden reference point measurement system includes the measuring tool 100 described above in the present application, it naturally has all the beneficial effects of the measuring tool 100 of the present application, which will not be described in detail here.
[0066] In some embodiments, the ball 130 is attracted to the reference ball seat 200 by magnetic force.
[0067] It should be noted that at least one of the sphere 130 and the reference sphere seat 200 is magnetic, enabling the sphere 130 to be magnetically attracted to the reference sphere seat 200. This magnetic force secures the entire measuring fixture 100 to the reference sphere seat 200. With this design, the sphere 130 is attracted to the reference sphere seat 200 and positioned within the spherical recess 210, with the spherical surface of the sphere 130 aligned with the spherical surface of the spherical recess 210.
[0068] The following describes the working principle of the hidden reference point measurement system of this application:
[0069] When it is necessary to detect the coordinates of the reference point of the tool to be detected, the ball 130 of the measuring tool 100 is brought close to the reference ball seat 200. Under the action of the magnetic force, the ball 130 will be adsorbed in the spherical groove 210, and under the action of the magnetic force, the measuring tool 100 as a whole can be fixed on the reference ball seat 200; then, the measuring tool 100 is rotated so that the target ball 120 of the measuring tool 100 is located at multiple different positions within the measurement range of the laser tracker 300, and the laser tracker 300 measures each position of the measuring target ball 120. Position coordinates; then, the operator calculates the coordinates of the center of the sphere 130 based on the position coordinates of the target sphere 120, that is, the coordinates of the shielded reference point. Specifically, the operator can input these position coordinates of the target sphere 120 into software such as SA, and use these software to fit these position coordinates of the target sphere 120 on a sphere. The center of the fitted sphere is the center of the sphere 130; after measuring the position coordinates of the target sphere 120, the operator removes the measuring tool 100 from the reference sphere seat 200.
[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.
[0071] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.
[0072] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.
Claims
1. A measuring tool, characterized in that: include: A connecting rod (110) having a first end and a second end disposed opposite to each other along a length direction of the connecting rod (110); a target ball (120), the target ball (120) being mounted on the first end of the connecting rod (110); A sphere (130) is mounted on the second end of the connecting rod (110), and the sphere (130) is used for being spherically hinged with a reference ball seat (200), wherein the reference ball seat (200) is mounted on the device to be detected (400).
2. The measuring tool according to claim 1, characterized in that: The measuring tool (100) further comprises a target seat (140), wherein the target seat (140) is connected to the target ball (120) and the first end of the connecting rod (110), and the target ball (120) is rotatably connected to the target seat (140).
3. The measuring tool according to claim 2, characterized in that: The target seat (140) is adsorbed on the connecting rod (110) by magnetic force; a spherical groove is provided on the target seat (140), the diameter of the spherical groove is consistent with the diameter of the target ball (120), and the target ball (120) is adsorbed on the target seat (140) by magnetic force and is partially located in the spherical groove.
4. The measuring tool according to claim 3, characterized in that: The target seat (140) is also bonded to the connecting rod (110).
5. The measuring tool according to claim 1, characterized in that: The measuring tool (100) further comprises a magnet (150), wherein the magnet (150) is fixedly connected to the second end of the connecting rod (110) and contacts the sphere (130), and under the action of the magnet (150), the sphere (130) has magnetism.
6. The measuring tool according to claim 1, characterized in that: The connecting rod (110) and the sphere (130) are connected via a first connecting member (160) and a second connecting member (170); the first connecting member (160) is fixedly connected to the second end of the connecting rod (110), the second connecting member (170) is fixedly connected to the sphere (130), and the first connecting member (160) and the second connecting member (170) are detachably connected.
7. The measuring tool according to claim 6, characterized in that: The first connecting member (160) and the second connecting member (170) are threadedly connected.
8. The measuring tool according to any one of claims 1 to 7, characterized in that: The connecting rod (110) comprises a first rod body (111) and a second rod body (112) connected to each other, wherein an end of the first rod body (111) away from the second rod body (112) is a first end, and an end of the second rod body (112) away from the first rod body (111) is a second end; The first rod (111) and the second rod (112) are capable of relative movement, so that the total length of the first rod (111) and the second rod (112) can be changed.
9. A hidden reference point measurement system, characterized in that: include: A reference ball seat (200), the reference ball seat (200) being used for fixed connection with the device to be detected (400), the reference ball seat (200) having a spherical groove (210); The measuring jig (100) according to any one of claims 1 to 8, wherein the diameter of the sphere (130) of the measuring jig (100) is the same as the diameter of the spherical groove (210), and the sphere (130) is partially located in the spherical groove (210) of the reference ball seat (200) to be spherically hinged with the reference ball seat (200); A laser tracker (300) is used to detect the coordinates of the target sphere (120).
10. A concealed reference point measurement system according to claim 9, characterized in that: The sphere (130) is adsorbed on the reference spherical seat (200) by magnetic force.