Measuring tool for positioning circle center
By using adjustable connecting plate and beam emitter technology in the center positioning measurement tool, the problem of limited measurement range of existing tools is solved, and the rapid and accurate center positioning of circular components of different sizes is achieved, and the measurement range is expanded. Improved efficiency.
Patent Information
- Application Number
- CN202420325025.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-21
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-02-21
AI Technical Summary
Existing center measurement tools are limited by the size of their measurement tools, resulting in a limited range of measurement and cannot accommodate circular components of different sizes and positions.
A measuring tool for center positioning is designed, including an adjustable first and second connecting plates, which simulates any string of the circle and uses a beam emitter to project the beam along the straight line where the second connecting plate is located, and observe the beam The intersection quickly finds the center of the circle, expanding the measurement range.
No complex calculations or indirect measurements are required, and the center of the circle can be positioned quickly and accurately. It is suitable for circular parts of different sizes and positions, expanding the measurement range and improving measurement efficiency and accuracy.
Smart Images
Figure CN222143958U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of mechanical technology, and in particular to a measuring tool for locating the center of a circle. Background Art
[0002] In the precision manufacturing industry, especially when dealing with circular structural components such as glass substrate transfer tanks, accurate determination of the center of the circle is a crucial basic step. This is because the accuracy of the center of the circle is directly related to the accuracy of the subsequent assembly process, the sealing performance, and the efficiency and safety of the overall equipment operation.
[0003] The traditional manual method of determining the center of a circle depends on accurate point selection, line drawing, calculation process and the size of the measuring tool. Measurement errors and inaccurate human operation will lead to a decrease in the accuracy of locating the center of a circle. The existing patent CN203216411U provides a measuring tool for determining the center of a circle, including a central truncated cone and a left connecting rod and a right connecting rod, both of which are rotatably connected to the center of the central truncated cone at one end, and the other ends of the left and right connecting rods are respectively fixedly connected to the left and right truncated cones with the same diameter as the central truncated cone; the perpendicular bisectors of the left and right connecting rods are respectively fixedly connected to the left and right measuring rods. The left and right connecting rods can rotate around the center of the central truncated cone, so that a certain angle can be formed between the two connecting rods to ensure that the central truncated cone and the left and right truncated cones are tangent to the circular component to be measured; according to the theorem that the perpendicular bisector of any chord in a circle must pass through the center of the circle, the intersection of the left and right measuring rods is the center of the measured circular center component. This measuring device avoids the complicated marking and calculation process, and the left measuring rod and the right measuring rod are set as telescopic rods, which can adapt to the measurement of larger circular parts and expand the measuring range. However, since the left and right connecting rods and the left and right measuring rods in this measuring device are of fixed length, and the left and right measuring rods are fixedly connected to the left and right connecting rods, the measuring range of the measuring device is still limited.
[0004] Therefore, a measuring tool for locating the center of a circle is needed to at least solve the above problems. Utility Model Content
[0005] A technical problem to be solved by the present disclosure is: how to solve the problem that the existing measuring tools for determining the center of a circle are limited by the size of the measuring tools, resulting in a limited measuring range.
[0006] In order to solve the above technical problems, an embodiment of the present disclosure provides a measuring tool for locating the center of a circle, including: a pair of first connecting plates rotatably connected at one end, the first connecting plate is provided with a measuring scale along its length direction, and the first connecting plate is used to simulate any chord of the circle to be measured; each first connecting plate is slidably connected to a second connecting plate along a direction perpendicular to its length direction, and the straight lines where the two second connecting plates are located can intersect at one point; and a first light beam emitter, a first light beam emitter is arranged on each second connecting plate, and the first light beam emitter is used to project a light beam along the straight line direction where the second connecting plate is located.
[0007] In some embodiments, the measuring tool for center positioning also includes: a connecting part, which is slidably connected to the first connecting plate along the length direction of the first connecting plate, and one end of the second connecting plate is connected to the connecting part; a first limiting part, which is connected to the connecting part and the first connecting plate and is used to limit the displacement of the connecting part relative to the first connecting plate.
[0008] In some embodiments, a through hole is provided on the surface of the connecting portion, and the first limiting portion passes through the through hole and abuts against the surface of the first connecting plate.
[0009] In some embodiments, the first light beam emitter is connected to the connecting portion.
[0010] In some embodiments, the plane where the pair of first connecting plates are located is parallel to the plane where the second connecting plates are located.
[0011] In some embodiments, the measuring tool for center positioning further includes: a first protractor, a first protractor is provided at the connection between each first connecting plate and the second connecting plate, and the first protractor is used to measure the angle between the second connecting plate and the first connecting plate.
[0012] In some embodiments, a pair of first connecting plates are rotatably connected via a rotating shaft; the circle center positioning measuring tool further includes: a second limiting portion, the second limiting portion is connected to the rotating shaft and the pair of first connecting plates, and is used to limit the rotation angle of the pair of first connecting plates.
[0013] In some embodiments, the first connecting plate and the second connecting plate are both rulers with scales.
[0014] In some embodiments, at least one second connecting plate is provided with a groove along the length direction; the center positioning measuring tool also includes: a second light beam emitter, which is slidably connected in the groove of a second connecting plate, and the second light beam emitter is used to project a light beam in a direction perpendicular to the plane where the two second connecting plates are located.
[0015] In some embodiments, the measuring tool for center positioning further includes: a second protractor, the center of the second protractor is rotatably connected to the connecting ends of a pair of first connecting plates.
[0016] Through the above technical scheme, the circle center positioning measuring tool provided by the present invention simulates any chord of a circle through a pair of adjustable first connecting plates, and uses two intersecting second connecting plates to locate the circle center. The technician only needs to adjust the position of the second connecting plate according to the scale to find the circle center without complicated calculations or indirect measurement methods. By setting a first light beam emitter that can emit a light beam along the straight line where the second connecting plate is located, the measurement can be quickly completed by observing the intersection of the light beams, so that the circle center positioning measuring tool is not limited by the size of the tool, thereby expanding the measurement range. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0018] Figure 1 It is a structural schematic diagram of a circle center positioning measuring tool disclosed in an embodiment of the present disclosure.
[0019] Description of reference numerals:
[0020] 1. First connecting plate; 2. Second connecting plate; 3. Connecting portion; 4. First limiting portion; 5. Rotating shaft; 6. Second protractor. DETAILED DESCRIPTION
[0021] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.
[0022] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.
[0023] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0024] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.
[0025] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.
[0026] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.
[0027] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.
[0028] Example 1
[0029] The embodiment of the present disclosure provides a measuring tool for locating the center of a circle, such as Figure 1As shown, it includes: a pair of first connecting plates 1 rotatably connected at one end, the first connecting plates 1 are provided with measuring scales along the length direction, and the first connecting plates 1 are used to simulate any chord of the circle to be measured; each first connecting plate 1 is slidably connected to a second connecting plate 2 along a direction perpendicular to the length direction, and the straight lines where the two second connecting plates 2 are located can intersect at one point; and a first light beam emitter, a first light beam emitter is arranged on each second connecting plate 2, and the first light beam emitter is used to project a light beam along the straight line direction where the second connecting plate 2 is located.
[0030] The first connecting plate 1 connected in a pair of rotations at one end can adapt to circles of different sizes and positions by adjusting the angle and position. The second connecting plate 2 is connected to the first connecting plate 1 in a sliding manner along the length direction perpendicular to the first connecting plate 1. Since the first connecting plate 1 is provided with a measuring scale along the length direction, when the first connecting plate 1 simulates any chord on the circle, the second connecting plate 2 connected thereto can slide to the perpendicular bisector of the chord. According to the theorem that the perpendicular bisector of any chord in a circle must pass through the center of the circle, when both second connecting plates 2 slide to the perpendicular bisector of the chord simulated by the first connecting plate 1, the two second connecting plates 2 intersect at one point, which is the center of the circle to be measured. When the area of the circle to be measured is large, the length of the two second connecting plates 2 cannot support them to intersect at one point. The center positioning measuring tool provided by the embodiment of the present disclosure is provided by setting a first light beam emitter on each second connecting plate 2. The first light beam emitter can project a light beam along the direction of the straight line where the second connecting plate 2 is located. The light beam emitter is used to directly form an optical path intersection in space, which can intuitively display the center position of the circle, thereby improving the measurement efficiency and accuracy.
[0031] The circle center positioning measuring tool provided in the embodiment of the present disclosure can be applied to the circle center measurement of circular parts in any field, such as the field of glass substrate and glass medicine tube manufacturing technology. In this field, a transfer tank is involved. The circle center positioning measuring tool can be used to determine the circle center during the manufacturing process of the cover, tank body and base of the transfer tank to ensure the sealing of the welding.
[0032] The circle center positioning measuring tool provided by the embodiment of the present disclosure simulates any chord of a circle through a pair of adjustable first connecting plates 1, and uses two intersecting second connecting plates 2 to locate the circle center. The technician only needs to adjust the position of the second connecting plates 2 according to the scale to easily find the circle center without complicated calculations or indirect measurement methods. The measurement can be quickly completed by observing the intersection of the light beams emitted by the first light beam emitter, so that the circle center positioning measuring tool is not limited by the size of the tool, further expanding the measurement range. Even in the face of large or difficult-to-reach circular areas, as long as the light beam can reach and form an intersection, the circle center positioning can be achieved without directly contacting the circle to be measured or using traditional ruler tools for cumbersome geometric construction. This makes the circle center positioning measuring tool highly practical and flexible in a variety of application scenarios.
[0033] In some embodiments, the measuring tool for center positioning also includes: a connecting part 3, which is slidably connected to the first connecting plate 1 along the length direction of the first connecting plate 1, and one end of the second connecting plate 2 is connected to the connecting part 3; a first limiting part 4, which is connected to the connecting part 3 and the first connecting plate 1, and is used to limit the displacement of the connecting part 3 relative to the first connecting plate 1.
[0034] The connecting part 3 can be a hollow rod structure or a slider, which can be sleeved on the first connecting plate 1 and can slide back and forth along the length direction of the first connecting plate 1. One end of the second connecting plate 2 is fixedly connected to the connecting part 3. When the connecting part 3 moves along the first connecting plate 1, the second connecting plate 2 will also move accordingly. The displacement of the connecting part 3 relative to the first connecting plate 1 is limited by the first limiting part 4, so that when the connecting part 3 drives the second connecting plate 2 to move to the perpendicular bisector of the chord simulated by the first connecting plate 1, the position of the second connecting plate 2 is fixed, so as to avoid the second connecting plate 2 and the perpendicular bisector of the chord being offset during the measurement process, thereby affecting the accuracy of the measurement.
[0035] In some embodiments, a through hole is provided on the surface of the connecting portion 3 , and the first limiting portion 4 passes through the through hole and abuts against the surface of the first connecting plate 1 .
[0036] The through hole is located on the surface of the connecting part 3, and can be circular, square or other shapes. The specific shape and size are designed according to actual needs. The function of the through hole is to allow the first limiting part 4 to pass through it, so as to achieve the limiting connection between the connecting part 3 and the first connecting plate 1. The first limiting part 4 can be a bolt top screw. The first limiting part 4 passes through the through hole and abuts against the surface of the first connecting plate 1, providing additional support and stability, and effectively preventing the accidental movement of the connecting part 3 during the measurement process. The design of the through hole makes the installation and disassembly of the first limiting part 4 simple and convenient. The technician only needs to pass the first limiting part 4 through the through hole, and then adjust its position so that it abuts against the surface of the first connecting plate 1. This design simplifies the assembly steps and improves the ease of operation.
[0037] In some embodiments, the first light beam emitter is connected to the connecting portion 3 .
[0038] By directly connecting the first light beam emitter to the connecting part 3 (not shown in the figure), the connecting part 3 not only supports the second connecting plate 2, but also supports and fixes the first light beam emitter. When the connecting part 3 slides along the first connecting plate 1, the first light beam emitter will also move with it and keep the relative position with the second connecting plate 2 unchanged, thereby improving the stability during the measurement process, reducing the shaking or deviation of the light beam, and thus improving the accuracy of the measurement. At the same time, the first light beam emitter is directly connected to the connecting part 3, avoiding additional supporting structures or connecting part 3 parts, and simplifying the structure of the entire measuring tool.
[0039] In some embodiments, the plane where the pair of first connecting plates 1 are located is parallel to the plane where the second connecting plates 2 are located.
[0040] When the two first connecting plates 1 simulate any chord of the circle to be measured and are placed on the same plane, the second connecting plate 2 will also be located outside this plane, but remain parallel to it. Since the planes where the first connecting plate 1 and the second connecting plate 2 are located are parallel to each other, this ensures that when the two second connecting plates 2 intersect, the intersection point (i.e., the center of the circle) they determine is accurate, so as to avoid measurement errors caused by angle deviation or misalignment.
[0041] In some embodiments, the measuring tool for center positioning also includes: a first protractor, a first protractor is provided at the connection between each first connecting plate 1 and the second connecting plate 2, and the first protractor is used to measure the angle between the second connecting plate 2 and the first connecting plate 1.
[0042] The first protractor can be a protractor with a scale available on the market (not shown in the figure), which can be connected to the connecting portion 3 through a fixed base. Since the connecting portion 3 is slidably connected to the first connecting plate 1, it cannot be ensured whether the second connecting plate 2 is absolutely perpendicular to the first connecting plate 1. Therefore, a first protractor is set, and the 0 scale line of the first protractor is aligned with the straight line where the first connecting plate 1 is located, and it is observed whether the straight line where the second connecting plate 2 is located is on the 90° scale line of the first protractor. By observing the scale on the first protractor to measure the angle between the second connecting plate 2 and the first connecting plate 1, it can help technicians accurately adjust the position of the second connecting plate 2, and use the first limit portion 4 to lock the connecting portion 3, so that the position of the center of the circle can be more accurately located.
[0043] In some embodiments, a pair of first connecting plates 1 are rotatably connected via a rotating shaft 5; the center positioning measuring tool also includes: a second limiting portion, which is connected to the rotating shaft 5 and the pair of first connecting plates 1 and is used to limit the rotation angle of the pair of first connecting plates 1.
[0044] A pair of first connecting plates 1 are connected in rotation by a rotating shaft 5, so that they can rotate around the rotating shaft 5 to simulate the chord of the circle to be measured. In order to limit the rotation angle of the pair of first connecting plates 1, the measuring tool for center positioning also includes a second limiting part (not shown in the figure), and the second limiting part can be an existing structure such as a damping device, a locking mechanism, etc., such as a structure that limits the rotation of the screen in a laptop computer. The damping device can provide resistance when the pair of first connecting plates 1 rotate to a certain angle, so that the pair of first connecting plates 1 stop rotating. The locking mechanism can lock the position of the first connecting plate 1 when the pair of first connecting plates 1 rotate to a certain angle to prevent the first connecting plate 1 from continuing to rotate. By setting the second limiting part to limit the rotation angle of the first connecting plate 1, when the first connecting plate 1 simulates a specific chord on the circle to be measured, due to the limiting effect of the second limiting part, the first connecting plate 1 will remain stable at a specific angle and will not continue to rotate, so that the position of the chord can be more accurately controlled and adjusted. By setting the second limiting part, the operation difficulty and error of the technician can also be reduced, and the accuracy and efficiency of the measurement are improved.
[0045] In some embodiments, the first connecting plate 1 and the second connecting plate 2 are both rulers with scales.
[0046] The ruler can be a commercial item. Since the ruler is thin and light, it is easy to carry. At the same time, it can also make the circle center positioning measuring tool closer to the surface of the circle to be measured during the measurement process, so that the technician can read the scale value more intuitively to determine the position of a pair of first connecting plates 1 relative to the circle to be measured, and the relative position between the first connecting plate 1 and the second connecting plate 2, thereby reducing the measurement error and improving the accuracy of the measurement. Since the first connecting plate 1 and the second connecting plate 2 are both rulers, they can be used not only to measure length, but also to draw straight lines or mark positions. This makes the circle center positioning measuring tool have more functions and is suitable for different application scenarios.
[0047] In some embodiments, at least one second connecting plate 2 is provided with a groove along the length direction; the center positioning measuring tool also includes: a second light beam emitter, the second light beam emitter is slidably connected to the groove of a second connecting plate 2, and the second light beam emitter is used to project a light beam in a direction perpendicular to the plane where the two second connecting plates 2 are located.
[0048] When the center positioning measuring tool needs to measure the center of a structure such as a cylinder or a circular tube, since the cylinder or circular tube is hollow, it is impossible to directly measure the correct position of its center point during measurement. Therefore, the center positioning measuring tool provided by the embodiment of the present disclosure can be provided with a second light beam emitter for making auxiliary lines projected on a certain plane. Through a pair of first connecting plates 1, any two chords of a circular tube mouth are simulated, and two second connecting plates 2 are slid to the perpendicular bisectors of the two chords. When the two second connecting plates 2 intersect at a point, the point is the projection of the center of the cylinder or circular tube. The second light beam emitter is slid to the intersection point, and the second light beam emitter is used to project a light beam into the tube in a direction perpendicular to the plane where the two intersecting second connecting plates 2 are located. The path of the light beam in the tube is the center line, and then it is projected on the outer plane of the cylinder or circular tube, so that the true position of the center of the cylinder or circular tube can be measured, which not only improves the accuracy of the measurement, but also enhances the practicality and versatility of the measuring tool.
[0049] The first light beam emitter and the second light beam emitter may be infrared laser pens.
[0050] In some embodiments, the measuring tool for center positioning further includes: a second protractor 6 , the center of the second protractor 6 is rotatably connected to the connecting ends of a pair of first connecting plates 1 .
[0051] The second protractor 6 can be a semicircular or circular protractor with a scale marked on its edge for measuring angles. The center of the second protractor 6 can be designed with an axis or pin, which is inserted into the hole or groove of the connecting end of a pair of first connecting plates 1, thereby allowing the second protractor 6 to rotate freely around this axis or pin, so that the center of the second protractor 6 is rotatably connected to the connecting end of a pair of first connecting plates 1. When the second protractor 6 is rotatably connected to the connecting end of a pair of first connecting plates 1, the technician can observe the relative angle between the first connecting plate 1 and the second protractor 6. The second protractor 6 can not only measure the angle between a pair of first connecting plates 1, but also can be used independently, for example, to draw arcs or mark positions, which makes the center-of-circle positioning measuring tool have more functions and is suitable for different application scenarios.
[0052] The method of using the circle center positioning measurement tool provided in the embodiment of the present disclosure is described as follows:
[0053] like Figure 1As shown, a pair of 65cm long first connecting plates 1 with a 0cm scale are placed on the edge of the circle to be measured, and then the 30cm scale of each first connecting plate 1 is also placed on the edge of the circle to be measured, and one edge of two 40cm long second connecting plates 2 is respectively moved to the 15cm scale of the first connecting plate 1 connected thereto, and locked by the first limiter 4. The intersection of the two edges of the two second connecting plates 2 on the 15cm scale is the center of the circle to be measured. The center positioning measuring tool is suitable for measuring circles with a diameter range of 10cm to 300cm. If it is necessary to find the center point of a circle with a larger diameter to be measured, the first light beam emitter set on the second connecting plate 2 can be turned on. The above sizes and positions of the first connecting plate 1 and the second connecting plate 2 are just examples, and can be adjusted according to actual needs.
[0054] The circle center positioning measuring tool provided by the embodiment of the present disclosure can also be used in another way. For example, when a circle with a smaller diameter needs to be measured, if the first connecting plate 1 simulates the chord of the circle, the measurement result will be inaccurate. Due to the adjustability of the first connecting plate 1 and the second connecting plate 2, a pair of first connecting plates 1 and a pair of second connecting plates 2 can be tangent to the edge of the circle to be measured, so that the circle center positioning measuring tool can be enclosed into a square. After the square is formed, the technician can find the center of the circle by connecting the diagonals of the square. This method is particularly suitable for measuring circles with smaller diameters, thereby further broadening the scope of application of the tool.
[0055] The circle center positioning measuring tool provided in the embodiment of the present disclosure can accurately find the position of the circle center by simulating the chord and perpendicular bisector of the circle to be measured and utilizing light beam projection technology, thereby improving the measurement accuracy and simplifying the operation process. Moreover, it is not limited by the size of the tool and the measurement range is expanded, which makes the circle center positioning measuring tool highly practical and flexible in a variety of application scenarios.
[0056] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.
[0057] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.
Claims
1. A measuring tool for locating the center of a circle, characterized in that: include: A pair of first connecting plates (1) rotatably connected at one end, the first connecting plate (1) being provided with a measuring scale along its length direction, and the first connecting plate (1) being used to simulate any chord of a circle to be measured; Each of the first connecting plates (1) is slidably connected to a second connecting plate (2) along a direction perpendicular to its length, and the straight lines on which the two second connecting plates (2) are located can intersect at one point; and A first light beam emitter, one of the first light beam emitters is arranged on each of the second connecting plates (2), and the first light beam emitter is used to project a light beam along the straight line direction where the second connecting plates (2) are located.
2. The circle center positioning measuring tool according to claim 1, characterized in that: Also includes: A connecting portion (3), wherein the connecting portion (3) is slidably connected to the first connecting plate (1) along the length direction of the first connecting plate (1), and one end of the second connecting plate (2) is connected to the connecting portion (3); A first limiting portion (4), the first limiting portion (4) is connected to the connecting portion (3) and the first connecting plate (1), and is used to limit the displacement of the connecting portion (3) relative to the first connecting plate (1).
3. The circle center positioning measuring tool according to claim 2, characterized in that: A through hole is provided on the surface of the connecting portion (3), and the first limiting portion (4) passes through the through hole and abuts against the surface of the first connecting plate (1).
4. The circle center positioning measuring tool according to claim 2, characterized in that: The first light beam emitter is connected to the connecting portion (3).
5. The circle center positioning measuring tool according to claim 1, characterized in that: The plane where the pair of first connecting plates (1) are located is parallel to the plane where the second connecting plates (2) are located.
6. The circle center positioning measuring tool according to claim 1, characterized in that: Also includes: A first protractor is provided at the connection between each of the first connecting plate (1) and the second connecting plate (2), and the first protractor is used to measure the angle between the second connecting plate (2) and the first connecting plate (1).
7. The circle center positioning measuring tool according to claim 1, characterized in that: A pair of the first connecting plates (1) are rotatably connected via a rotating shaft (5); Also includes: A second limiting portion, the second limiting portion is connected to the rotating shaft (5) and the pair of the first connecting plates (1), and is used to limit the rotation angle of the pair of the first connecting plates (1).
8. The circle center positioning measuring tool according to claim 1, characterized in that: The first connecting plate (1) and the second connecting plate (2) are both rulers with scales.
9. The circle center positioning measuring tool according to claim 1, characterized in that: At least one of the second connecting plates (2) is provided with a groove along the length direction; Also includes: A second light beam emitter, the second light beam emitter is slidably connected in the groove of one of the second connecting plates (2), and the second light beam emitter is used to project a light beam in a direction perpendicular to the plane where the two second connecting plates (2) are located.
10. The circle center positioning measuring tool according to claim 1, characterized in that: Also includes: A second protractor (6), the center of the circle of the second protractor (6) is rotatably connected to the connecting ends of a pair of the first connecting plates (1).