Self-adaptive measuring device

Abstract

The embodiment of the utility model provides a self-adaptive measuring device, which is used for measuring the size parameter of an internal thread, and comprises a body; the first arm and the second arm are used for being inserted into the internal threads, extend in the first direction and are arranged on the body so that the second arm can move on the body relative to the first arm; the pair of abutting pieces are arranged on the side walls of the first arm and the second arm in a manner of extending oppositely in the second direction, and the end points of the pair of abutting pieces abut against the tooth bottom of the to-be-detected internal thread or abut against the tooth top of the to-be-detected internal thread; a fall matched with the pitch of the internal thread to be detected is formed between the pair of abutting pieces in the first direction. And the measurement reading unit is arranged on the body and is configured to display a relative displacement value between the first arm and the second arm so as to obtain the diameter length of the internal thread to be detected according to the relative displacement value. According to the invention, the height difference between the first arm and the second arm is adjusted to adapt to the pitch of various internal thread types, and the major diameter of the internal thread is accurately measured through the pair of abutting pieces.

Description

Technical Field

[0001] The present disclosure relates to the technical field of measuring tools, and in particular to an adaptive measuring device. Background Art

[0002] With the rapid development of modern industrial technology, especially the progress in precision machining and automated production, the requirements for the dimensional accuracy of parts are becoming increasingly stringent. Among them, the thread is a key element of connection and sealing, and its dimensional accuracy is directly related to the reliability and service life of the product. The measurement of internal threads, especially the large diameter measurement, has always been an important part of manufacturing and quality control. However, due to technical limitations and the shortcomings of traditional methods, it has led to problems such as low measurement efficiency and limited accuracy, and innovative solutions are urgently needed.

[0003] In the relevant internal thread measurement technology, the difficulties in measuring the major diameter are mainly reflected in the following aspects:

[0004] The measuring tools lack versatility and adaptability. The internal thread measuring tools in related technologies are often highly targeted and have poor adaptability to threads of different pitches and types (such as trapezoidal, pipe threads, and serrated threads). Measuring tools need to be customized according to different threads, resulting in low measurement efficiency and difficulty in meeting diversified production needs.

[0005] When measuring internal threads, especially large diameters, the depth of the threads, deep holes or the complexity of the thread structure increase the difficulty of measurement. Conventional tools are difficult to reach or contact, which affects the accuracy and efficiency of the measurement results. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an adaptive measurement device to solve the problems in the related art.

[0007] The present disclosure provides, in a first aspect, an adaptive measuring device for measuring dimensional parameters of an internal thread, comprising:

[0008] ontology;

[0009] A first arm and a second arm for inserting the internal thread, the first arm and the second arm extending along a first direction, and disposed on the body so that the second arm moves on the body relative to the first arm;

[0010] A pair of abutting members are respectively arranged on the side walls of the first arm and the second arm and extend in opposite directions along the second direction, and the end points of the pair of abutting members are respectively used to abut against the root of the internal thread to be detected, or respectively abut against the top of the internal thread to be detected; and a drop is formed between the pair of abutting members along the first direction to match the pitch of the internal thread to be detected;

[0011] The measurement reading unit is arranged on the main body and is configured to display the relative displacement value between the first arm and the second arm so as to obtain the diameter length of the internal thread to be detected according to the relative displacement value.

[0012] In an embodiment of the first aspect, the second arm includes a first moving portion, which is disposed on the body and moves on the body along the second direction.

[0013] In an embodiment of the first aspect, the second arm further comprises a second movable portion, which is disposed on the first movable portion and is movable along a first direction, so that the pair of abutting members form a drop along the first direction that matches the pitch of the internal thread to be detected.

[0014] In an embodiment of the first aspect, it includes: a locking mechanism for locking the second moving part on the second arm.

[0015] In an embodiment of the first aspect, the first moving part is further provided with an adjustment scale matching different tooth pitches.

[0016] In an embodiment of the first aspect, a drop formed by the pair of abutting members along the first direction is half of the tooth pitch.

[0017] In an embodiment of the first aspect, a shape of the pair of abutment members matches a root shape of the internal thread to be inspected.

[0018] In an embodiment of the first aspect, the path length is the sum of the relative displacement value and a preset value; the preset value is determined by a preset distance between a pair of calibration members respectively abutting against end points of the pair of abutting members.

[0019] In an embodiment of the first aspect, the relative displacement value includes a first relative displacement value between the first arm and the second arm obtained by reading the first relative displacement value between the first arm and the second arm obtained by indicating that the end points of the pair of abutting members abut against the root of the internal thread to be detected;

[0020] And / or, the relative displacement value also includes a second relative displacement value between the first arm and the second arm obtained by reading when the endpoints of the pair of abutting members abut against the crest of the internal thread to be tested.

[0021] In an embodiment of the first aspect, the measurement reading unit includes a reader disposed on the second arm, for reading the relative displacement value between the second arm and the first arm;

[0022] And / or, the measurement and reading unit includes a scale mechanism arranged on the body, which is used to read the distance between the first arm and the second arm to obtain the relative displacement value.

[0023] The beneficial effects of the present invention are as follows: in the present invention, by adjusting the drop between the first arm and the second arm, the pitch of various types of internal threads can be adapted, the measurement requirements of different industries and complex parts can be met, the versatility of the tool is improved, and a pair of abutments can abut the bottom or top of the internal thread to accurately measure the major diameter of the internal thread. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram showing the structure of a measuring device in one embodiment of the present disclosure is shown.

[0025] Figure 2 A schematic diagram of the local structure of a measuring device that contacts the root of an internal thread in an embodiment of the present disclosure is shown.

[0026] Figure 3 A schematic diagram of a partially enlarged structure showing an abutment member abutting against a bottom of an internal thread in an embodiment of the present disclosure.

[0027] Figure 4 A schematic diagram showing the structure of a measuring device measuring a standard block and returning the reading to zero in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] The following is an explanation of the embodiments of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the information disclosed by the present disclosure. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in the present disclosure can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0029] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0030] In the representations of the present disclosure, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples represented in the present disclosure and the features of different embodiments or examples, unless they are mutually contradictory.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of the present disclosure, "a group" means two or more, unless otherwise clearly and specifically defined.

[0032] In order to clearly describe the present disclosure, components not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0033] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0034] Although the terms first, second, etc. are used to represent various elements in this article in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate that there are the described features, steps, operations, elements, modules, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or a group of other features, steps, operations, elements, modules, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0035] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present disclosure. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0036] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which the present disclosure belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and shall not be overly interpreted as ideal or very formal meanings unless defined.

[0037] In related technologies, the difficulties in measuring large diameters are mainly reflected in the following aspects:

[0038] The measuring tools lack versatility and adaptability. The internal thread measuring tools in related technologies are often highly targeted and have poor adaptability to threads of different pitches and types (such as trapezoidal, pipe threads, and serrated threads). Measuring tools need to be customized according to different threads, resulting in low measurement efficiency and difficulty in meeting diversified production needs.

[0039] When measuring internal threads, especially large diameters, the depth of the threads, deep holes or the complexity of the thread structure increase the difficulty of measurement. Conventional tools are difficult to reach or contact, which affects the accuracy and efficiency of the measurement results.

[0040] In the present invention, the gap between the first arm and the second arm is adjusted to adapt to the pitch of various types of internal threads, thereby meeting the measurement needs of different industries and complex parts, improving the versatility of the tool, and a pair of abutments can abut the bottom or top of the internal thread to accurately measure the major diameter of the internal thread.

[0041] exist Figure 1 In the example, a represents movement in the second direction, b represents movement in the first direction, and H represents the height difference H between a pair of abutting members 400 .

[0042] In a first aspect, an adaptive measuring device is provided for measuring the dimensional parameters of an internal thread. Figure 1 In the example shown in the figure, the measuring device includes:

[0043] Ontology 100;

[0044] A first arm 200 and a second arm 300 for inserting the internal thread, the first arm 200 and the second arm 300 extending along a first direction and disposed on the body 100 so that the second arm 300 moves on the body 100 relative to the first arm 200;

[0045] A pair of abutting members 400 are respectively disposed on the side walls of the first arm 200 and the second arm 300 and extend in opposite directions along the second direction. Figure 2In the example, the end points of the pair of abutting members 400 are respectively used to abut against the root 401 of the internal thread to be detected, or respectively abut against the top 402 of the internal thread to be detected; a drop H matching the pitch of the internal thread to be detected is formed between the pair of abutting members 400 along the first direction;

[0046] The measurement reading unit 500 is disposed on the body 100 and is configured to display the relative displacement value between the first arm 200 and the second arm 300 so as to obtain the diameter length of the internal thread to be detected according to the relative displacement value.

[0047] Specifically, in some embodiments, the second arm 300 is slidably disposed on the body along the first direction, which can be achieved in the following ways.

[0048] For example, at the connection between the main body and the second arm 300, a precision ball track structure is provided, and the second arm 300 is equipped with a matching ball seat, and the ball rolls in the track, so that the second arm 300 can slide smoothly and stably. This method reduces friction, improves the sensitivity and durability of movement, and makes operation more labor-saving.

[0049] For another example, a sliding structure using a linear guide and a slider is used, wherein the second arm 300 is equipped with a slider and a linear guide is installed inside the body. The guide provides high rigidity and ensures the accuracy of linear motion, which is suitable for heavy loads or situations requiring precise measurement. The slider moves along the guide to achieve adjustment. Alternatively, the second arm 300 is provided with a sleeve portion that is slidably connected to the body, and the body passes through the sleeve portion so as to be able to slide along a first direction. Optionally, after sliding, the second arm 300 can be fixed to the body by fasteners such as screws or buckles. This design facilitates positioning. When manual adjustment is required, the fasteners are first loosened, and the second arm 300 slides into place along the body and then tightened. This is suitable for multi-point measurement that requires positioning.

[0050] In some embodiments, the end point shape of each abutment 400 can match the shape of the root 401 of the internal thread so as to abut against the bottom surface of the root 401, thereby directly and accurately measuring the major diameter. For example, the end point can be constructed as a sharp angle or a sphere. The internal thread is formed by spirally ascending or descending along a cylindrical surface. The root 401 of each circle is not on the same horizontal plane as the next top 402 point, but has a height difference. Therefore, this height difference, that is, the characteristic of the pitch, needs to be considered during measurement. In order to accurately measure the major diameter of the internal thread (the maximum width between two teeth), the end points of a pair of abutments need to abut against the root 401 with different heights on opposite sides, so a pair of abutments 400 move along the first direction to form a height difference H. In some embodiments, the pitch of threads varies, and the pitch of threads of different specifications varies greatly. In order to adapt to various threads, the design of the drop H can realize universal measurement of threads with different pitches, which is not limited to a single pitch, thereby improving the versatility and scope of use of the tool. The user only needs to adjust the drop H between a pair of abutting members 400 according to the thread pitch, and does not need to frequently replace a pair of abutting members 400. As an example, the abutting members 400 are usually made of wear-resistant, high-hardness, and non-deformable materials, such as cemented carbide, carbide steel, or ceramics, to ensure that the measurement accuracy does not decrease after long-term use.

[0051] Optional, in Figure 1 In this example, the second arm 300 includes a first moving portion 301 , which is disposed on the body 100 and moves on the body 100 along the second direction.

[0052] Specifically, in some embodiments, the first movable portion 301 is a portion mounted on the main body, and is implemented by the second arm 300 slidingly mounted on the main body, which will not be elaborated herein.

[0053] Optionally, the first movable part 301 is provided with a manual or automatic locking knob, which can be locked on the main body after being adjusted into place, so as to ensure stable measurement, avoid slipping and displacement, and ensure stable and reliable readings.

[0054] Optional, in Figure 1 In the example, the second arm 300 further includes a second moving portion 302 disposed on the first moving portion 301 and movable along a first direction, so that the pair of abutting members 400 form a drop H along the first direction that matches the pitch of the internal thread to be detected.

[0055] Specifically, in some embodiments, the second moving part 302 can be designed as a sliding block, attached to the guide rail of the first moving part 301, and fine-tuning the distance along the first direction can be achieved through push-pull operations. The slider is clearly marked, the operation is intuitive, and positioning is simple and fast. The push-up member 400 disposed on the second moving part 302 can be moved in the first direction through the second moving part 302.

[0056] Optional, in Figure 1 In the example, it includes: a locking mechanism 700 for locking the second moving part 302 on the second arm 300 .

[0057] Specifically, in some embodiments, a locking mechanism 700 is provided between the second moving part 302 and the second arm 300, which may be a rotary knob or a paddle lock. When the user operates, the locking mechanism 700 is rotated to lock and fasten the second moving part 302. The locking and unlocking operations are simple. The manual knob or paddle design has a distinct hand feel distinction, and the operator can easily identify the locked and unlocked states. Optionally, the locking mechanism 700 is made of wear-resistant materials, such as stainless steel or hard plastic, to ensure a long service life and reduce wear.

[0058] Optionally, the connection method between the locking mechanism 700 and the second movable part 302 can be divided into two situations: integrated design and separate design, each of which optimizes the convenience of operation and maintenance according to actual needs. In the integrated design, the locking mechanism 700 is fixedly connected to the second movable part 302, which may be a built-in spring lock, magnet or rotating pin, which directly acts on the second movable part 302 during operation. The advantages are compactness, integration, reduced risk of loss, intuitive operation, and suitable for quick locking. In the separate design, the locking mechanism 700 is separated from the second movable part 302 and designed as an independent component, such as an external lock, screw or manual locking clip, which is externally inserted into the second movable part 302 during operation. It is easy to maintain, replace, and adjust flexibly. It is convenient for different sizes and suitable for complex environments.

[0059] Optional, in Figure 1 In the example, the first moving part 301 is further provided with an adjustment scale 600 matching different tooth pitches.

[0060] Specifically, in some embodiments, an adjustment scale 600 is provided on the first movable part 301, and the adjustment scale 600 corresponds to a common pitch to form the adjustment scale 600, such as ISO, UNC, UNF, Whitworth and other standard threads. Each scale is precisely marked to facilitate the user to align the thread pitch. Optionally, the display parameters of the adjustment scale 600 can be set. For example, the adjustment scale 600 can distinguish different types of pitches by color or number, and quickly locate. The user can recognize it at a glance without calculation, and directly align the second movable part 302 with the required scale, thereby improving efficiency, saving time, and reducing errors. The adjustment scale 600 covers a wide range and adapts to different thread pitches, from fine to coarse pitches, meeting multiple industry standards, and improving the compatibility and versatility of the device.

[0061] Optionally, corresponding to the adjustment scale 600, the second movable part 302 is provided with a series of preset adjustment holes, and the hole spacing matches the common tooth pitch, such as increasing or decreasing by .1mm. The holes are precisely distributed on the second movable part 302, corresponding to the movement range, to provide selective positioning. At this time, the locking mechanism 700 can be a locking pin or a pin. When the second movable part 302 is aligned with the adjustment hole, the pin is inserted to fix it, and the locking pin is in place to ensure the stability of the second movable part 302 and prevent movement.

[0062] Optional, in Figure 1 In the example, the height difference H formed by the pair of abutting members 400 along the first direction is half of the tooth pitch.

[0063] Specifically, in some embodiments, the height difference H set along the first direction of the pair of abutting members 400 is half of the pitch of the thread to be measured, that is, the center distance between the thread bottom and the thread top 402. The height difference H ensures that the abutting members 400 can accurately correspond to the thread top 402 and the thread bottom 401.

[0064] Optional, in Figure 2 or Figure 3 In the example, the shape of the pair of abutting members 400 matches the shape of the root 401 of the internal thread to be detected.

[0065] Specifically, in some embodiments, the shape of a pair of abutments 400 is the shape of the root 401 of the internal thread to be measured, whether it is a trapezoid, a sawtooth or a specific special shape, to improve the accuracy of the measurement point and reduce the measurement error. The side of the abutment 400 has an appropriate avoidance space to ensure the gap with the side of the internal thread to avoid interference, to ensure smooth insertion and removal during measurement without obstruction, to avoid scratches and damage to the thread surface, and to improve durability. Optionally, the end points of the pair of abutments 400 are designed to be smaller than a radius of the major diameter of the internal thread, to ensure that during measurement, even if the abutment 400 contacts the root 401, it will not get stuck or hinder the measurement of the major diameter, to ensure that the measurement point does not interfere with the inner diameter of the internal thread.

[0066] Optionally, the path length is the sum of the relative displacement value and a preset value; the preset value is determined by a preset distance between a pair of calibration members respectively abutting against the end points of the pair of abutting members 400.

[0067] Specifically, in some embodiments, Figure 4As an example, first use a pair of standard blocks with their slot width as calibration to zero the measuring device. The calibration process involves aligning the abutment 400 with the standard block and adjusting the reading unit to zero to ensure that the starting point of subsequent measurements is accurate and without offset. Next, gently insert the moving probe into the internal thread to be measured to ensure stable contact and penetrate into the thread root 401 or the top 402. During measurement, the value F is read, and F represents the relative displacement value of the moving head and the second arm 300, that is, the total position from the calibration point to the current point. Finally, the major diameter of the internal thread is calculated based on the obtained value. The calculation formula for the major diameter of the internal thread (D) is: D=F+S, where F is the value measured by the movement of the second arm 300, and S is the slot width of the calibration block, that is, the preset value. Through standard block calibration, the reading error is eliminated, the accuracy of the zero point of the measurement starting point is ensured, and the accuracy of subsequent readings is improved.

[0068] Optional, in Figure 2 In the example, the relative displacement value includes a first relative displacement value between the first arm 200 and the second arm 300 obtained by reading when the end points of the pair of abutting members 400 abut against the thread bottom 401 of the internal thread to be detected.

[0069] Specifically, in some embodiments, the measuring device can be used to measure the major diameter and minor diameter of the internal thread. When the end points of a pair of abutments 400 contact the root 401 of the internal thread, the displacement value between the first arm 200 and the second arm 300 is the "first relative displacement value" F1. At this time, the value of the major diameter is calculated.

[0070] In another example, the relative displacement value may also be a second relative displacement value between the first arm 200 and the second arm 300 obtained by reading when the end points of the pair of abutting members 400 abut against the crest 402 of the internal thread to be detected.

[0071] Specifically, in some embodiments, when the end point of the abutment 400 is aligned with the crest 402 of the internal thread, the displacement value between the first arm 200 and the second arm 300 is measured and recorded as the "second relative displacement value" F2. At this time, the value of the minor diameter is calculated.

[0072] Optionally, the measuring device can be rotated at different angles to evaluate the roundness and ovality of the internal thread, ensuring comprehensiveness of the measurement by capturing the changes in the thread in different directions.

[0073] Roundness refers to the uniformity of the thread shape. Rotational measurement can detect whether the diameters of the thread are consistent at different sections. If they are not consistent, and if the measured values ​​at each point fluctuate greatly, it indicates that the thread may deviate from a circle and be elliptical.

[0074] Optional, in Figure 1In the example, the measurement and reading unit 500 includes a reader 501 disposed on the second arm 300 , and configured to read the relative displacement value between the second arm 300 and the first arm 200 .

[0075] Specifically, in some embodiments, a reader 501 is provided on the second arm 300, and a sensor (such as LVDTI2C or Hall effect sensor) can be used to continuously monitor the displacement value. The measurement of the reader 501 belongs to the prior art, and the present disclosure does not involve the improvement of the reader 501.

[0076] Optional, in Figure 1 In the example, the measurement reading unit 500 includes a scale mechanism 502 disposed on the body 100 , and is used to read the distance between the first arm 200 and the second arm 300 to obtain the relative displacement value.

[0077] Specifically, in some embodiments, the relative displacement value may also be manually read through the scale mechanism 502 .

[0078] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the protection scope of the present disclosure.

Claims

1. An adaptive measuring device, characterized in that: Used for measuring the dimensional parameters of internal threads, including: ontology; A first arm and a second arm for inserting the internal thread, the first arm and the second arm extending along a first direction, and disposed on the body so that the second arm moves on the body relative to the first arm; A pair of abutting members are respectively arranged on the side walls of the first arm and the second arm and extend in opposite directions along the second direction, and the end points of the pair of abutting members are respectively used to abut against the root of the internal thread to be detected, or respectively abut against the top of the internal thread to be detected; and a drop is formed between the pair of abutting members along the first direction to match the pitch of the internal thread to be detected; The measurement reading unit is arranged on the main body and is configured to display the relative displacement value between the first arm and the second arm so as to obtain the diameter length of the internal thread to be detected according to the relative displacement value.

2. The measuring device according to claim 1, characterized in that The second arm includes a first moving portion, which is disposed on the body and moves on the body along the second direction.

3. The measuring device according to claim 2, characterized in that The second arm further comprises a second moving portion, which is arranged on the first moving portion and can move along a first direction, so that the pair of abutting members form a drop along the first direction that matches the pitch of the internal thread to be detected.

4. The measuring device according to claim 3, characterized in that include: The locking mechanism is used to lock the second moving part on the second arm.

5. The measuring device according to claim 2, characterized in that The first movable portion is also provided with an adjustment scale matching different tooth pitches.

6. The measuring device according to claim 1, characterized in that The drop formed by the pair of abutting members along the first direction is half of the tooth pitch.

7. The measuring device according to claim 1, characterized in that The shape of the pair of abutment members matches the root shape of the internal thread to be detected.

8. The measuring device according to claim 1, characterized in that The path length is the sum of the relative displacement value and a preset value; the preset value is determined by a preset distance between a pair of calibration members respectively abutting against the end points of the pair of abutting members.

9. The measuring device according to claim 1, characterized in that The relative displacement value includes a first relative displacement value between the first arm and the second arm obtained by reading the first relative displacement value between the first arm and the second arm when the end points of the pair of abutting members abut against the root of the internal thread to be detected; And / or, the relative displacement value also includes a second relative displacement value between the first arm and the second arm obtained by reading when the endpoints of the pair of abutting members abut against the crest of the internal thread to be tested.

10. The measuring device according to claim 1, characterized in that The measurement and reading unit comprises a reader arranged on the second arm, for reading the relative displacement value between the second arm and the first arm; And / or, the measurement and reading unit includes a scale mechanism arranged on the body, which is used to read the distance between the first arm and the second arm to obtain the relative displacement value.

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