Dynamic inward inclination measuring device for turnout wing rail

Abstract

The utility model provides a turnout wing rail dynamic inward inclination measuring device which comprises two supporting columns and a follow-up structure, the two supporting columns are used for being connected with two ballast bed structures on the two sides of a wing rail respectively, and the two supporting columns extend in the vertical direction; the follow-up structure is located between the two supporting columns and comprises a sliding part and a connecting part, the two ends of the sliding part are in sliding connection with the two supporting columns respectively, the connecting part is arranged on the surface of the side, facing the wing rails, of the sliding part, and the connecting part is used for being connected with a to-be-detected wing rail in the two wing rails, so that when the to-be-detected wing rail inclines inwards, the to-be-detected wing rail inclines inwards; the measuring device is used for measuring the first sliding distance h1 and the second sliding distance h2 of the two ends of the sliding part sliding on the corresponding supporting columns respectively. According to the utility model, the problem that the dynamic inward inclination of the wing rail cannot be measured when a train passes in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of rail transit engineering, in particular to a device for measuring the dynamic inclination of a turnout wing rail. Background Art

[0002] There are usually many structural components at high-speed turnouts, and the speed of trains passing through turnouts is high, resulting in more severe impact between wheels and rails. Especially in the frog area of ​​high-speed turnouts, due to the presence of wheel load transition, high-speed trains will inevitably impact the wing rails when passing through the turnouts in the forward direction. The wing rails at some high-speed turnouts are made of ordinary steel rails, and the bottom of the wing rails has been cut. Under the impact load of the train, the wing rails are prone to vertical displacement and inward deformation. In addition, the bottom of the wing rail is in direct rigid contact with the iron pad. After the wing rail is inwardly tilted, the bottom of the wing rail is partially in contact with the iron pad, and the contact stress of the bottom of the wing rail increases sharply, reducing the fatigue performance of the wing rail.

[0003] However, in the prior art, the maintenance and repair of high-speed turnouts mainly focuses on the gap between the bottom of the wing rail and the iron pad under static conditions, and is unable to effectively measure the inclination of the wing rail under dynamic conditions. Once the inclination of the bottom of the wing rail is too large, it is easy to cause a sharp increase in the dynamic contact stress between the bottom edge of the wing rail and the iron pad, causing fatigue damage to the bottom of the wing rail.

[0004] In the prior art, a feeler gauge with a suitable thickness is usually used to repeatedly slide the gauge on the bottom of the wing rail one by one to confirm the size of the gap between the bottom of the wing rail and the iron pad. However, since there are many components in the frog structure, such as the heart rail, two wing rails and the top iron in a narrow space, it is difficult to measure directly with a feeler gauge. Therefore, there are difficulties in testing the method, a large workload for measurement, and the existing measurement method can only evaluate the gap under static conditions. If the elastic iron pad at the bottom of the wing rail is suspended, the dynamic deformation of the wing rail will be further increased, and its dynamic inward inclination will also increase accordingly. Only by measuring the dynamic inward inclination of the wing rail under the train load can the contact state between the bottom of the wing rail and the iron pad be effectively evaluated.

[0005] Therefore, it is necessary to propose a new testing device that can measure the dynamic inclination of the wing rail when a train passes by. Utility Model Content

[0006] The main purpose of the utility model is to provide a device for measuring the dynamic inclination of a turnout wing rail, so as to solve the problem in the prior art that the dynamic inclination of the wing rail cannot be measured when a train passes by.

[0007] In order to achieve the above-mentioned purpose, the utility model provides a dynamic inclination measuring device for a turnout wing rail, comprising two support columns and a follower structure, wherein the two support columns are respectively used to connect with two roadbed structures on both sides of the wing rail, and the two support columns extend in the vertical direction; the follower structure is located between the two support columns, and the follower structure comprises a sliding part and a connecting part, wherein the two ends of the sliding part are respectively slidably connected with the two support columns, the connecting part is arranged on the surface of the sliding part facing the wing rail, and the connecting part is used to connect with a wing rail to be measured among the two wing rails, so as to measure a first sliding distance h1 and a second sliding distance h2 of the two ends of the sliding part sliding on their respective corresponding support columns when the wing rail to be measured produces an inclination.

[0008] Furthermore, the sliding portion is detachably connected to the connecting portion.

[0009] Furthermore, the support column is detachably connected to the track bed structure.

[0010] Furthermore, the sliding portion includes a support beam and two slider structures, wherein the connecting portion is arranged on the surface of the support beam facing the wing rail; the two slider structures are respectively slidably arranged on two support columns, and the two slider structures are respectively hingedly matched with both ends of the support beam.

[0011] Furthermore, the support beam has a receiving cavity, which extends along the length direction of the support beam. The receiving cavity contains liquid and bubbles insoluble in the liquid, which are used for horizontal calibration when installing the support beam.

[0012] Furthermore, the connecting portion has a limiting groove, and the limiting groove is used to accommodate a part of the non-working side of the wing rail to be tested.

[0013] Furthermore, the groove contour line of the limiting groove is at least adapted to the outer contour line of the non-working side for fitting with the groove wall surface of the limiting groove.

[0014] Furthermore, the connecting portion includes a first beam section, a transition section and a second beam section connected to each other, wherein the first beam section and the second beam section are both arranged in the horizontal direction, and the transition section is arranged in the vertical direction, so that the first beam section, the transition section and the second beam section form a C-shaped limiting groove.

[0015] Further, the length of the first beam section is smaller than the length of the second beam section.

[0016] Further, at least the length of the second beam section is equal to the length of the bottom outer surface of the wing rail to be measured.

[0017] Furthermore, both support columns have slide grooves, and both ends of the sliding part are slidably arranged in the two slide grooves respectively, and scale lines are provided at the edges of the slide grooves for reading the first sliding distance h1 and the second sliding distance h2 of the two ends of the sliding part.

[0018] By applying the technical solution of the utility model, a device for measuring the dynamic inward inclination of a turnout wing rail is provided. The device for measuring the dynamic inward inclination of a turnout wing rail is configured to include two support columns and a follower structure. Meanwhile, the follower structure includes a sliding portion and a connecting portion. Both ends of the sliding portion are respectively slidably connected to the two support columns. The connecting portion is arranged on the surface of the sliding portion facing the wing rail. When measuring the inward inclination of one of the two wing rails, it is only necessary to connect the connecting portion to the wing rail. Thus, since the follower structure is connected to the wing rail to be measured as a whole, when the wing rail to be measured is inclinated during the passage of a train, both ends of the sliding portion of the follower structure slide on their respective corresponding support columns by a first sliding distance h1 and a second sliding distance h2. In addition, the distances between the two support columns and the fulcrum A on the wing rail to be measured are a first length L1 and a second length L2, which are known values. According to the calculated formula The inclination D of the wing rail to be measured can be directly calculated i , where the first sliding distance h1 is the sliding displacement of the end of the sliding part on one side of the wing rail to be measured, and the second sliding distance h2 is the sliding displacement of the other end of the sliding part on the opposite side of the wing rail to be measured, R b The width of the bottom of the wing rail. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0020] Figure 1 A schematic diagram showing a structure in which a device for measuring the dynamic inclination of a turnout wing rail according to an optional embodiment of the utility model is installed between two support columns;

[0021] Figure 2 Shows Figure 1 A schematic diagram of the structure of the state in which one of the two wing rails is in an inward tilt, in which the other wing rail is omitted;

[0022] Figure 3 Shows Figure 1 Schematic diagram of the structure of the support column of the turnout wing rail dynamic inclination measurement device.

[0023] The above drawings include the following reference numerals:

[0024] 1. Wing rail; 2. Ballast bed structure;

[0025] 10. Support column; 11. Slideway; 12. Scale line; 13. Pointer;

[0026] 20. Follow-up structure; 21. Sliding portion; 211. Support beam; 212. Sliding block structure; 22. Connecting portion; 221. Limiting groove; 222. First beam section; 223. Transition section; 224. Second beam section. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] In order to solve the problem in the prior art that the dynamic inclination of the wing rail cannot be measured when a train passes by, the utility model provides a device for measuring the dynamic inclination of the turnout wing rail.

[0029] like Figures 1 to 3 As shown, the dynamic inclination measuring device of the turnout wing rail includes two support columns 10 and a follower structure 20, wherein the two support columns 10 are respectively used to connect with the two ballast structures 2 on both sides of the wing rail 1, and the two support columns 10 extend in the vertical direction; the follower structure 20 is located between the two support columns 10, and the follower structure 20 includes a sliding portion 21 and a connecting portion 22, wherein the two ends of the sliding portion 21 are respectively slidably connected with the two support columns 10, the connecting portion 22 is arranged on the surface of the sliding portion 21 facing the wing rail 1, and the connecting portion 22 is used to connect with one of the two wing rails 1, so as to measure the first sliding distance h1 and the second sliding distance h2 of the two ends of the sliding portion 21 sliding on the respective corresponding support columns 10 when the wing rail 1 to be measured generates an inclination.

[0030] The present application provides a device for measuring the dynamic inward inclination of a turnout wing rail. The device is configured to include two support columns 10 and a follower structure 20. Meanwhile, the follower structure 20 includes a sliding portion 21 and a connecting portion 22. The two ends of the sliding portion 21 are respectively slidably connected to the two support columns 10. The connecting portion 22 is arranged on the surface of the sliding portion 21 facing the wing rail 1. When measuring the inward inclination of one of the two wing rails 1, it is only necessary to connect the connecting portion 22 to the wing rail 1. In this way, since the follower structure 20 is connected to the wing rail 1 to be measured as a whole, when the wing rail 1 to be measured is inclinated during the passage of a train, the two ends of the sliding portion 21 of the follower structure 20 slide on the corresponding support columns 10 by a first sliding distance h1 and a second sliding distance h2. In addition, the distances between the two support columns 10 and the fulcrum A on the wing rail 1 to be measured are respectively a first length L1 and a second length L2, which are known values. According to the inferred formula The inclination D of the wing rail 1 to be measured can be directly calculated i , wherein the first sliding distance h1 is the sliding displacement of the end of the sliding portion 21 on one side of the wing rail 1 to be measured, and the second sliding distance h2 is the sliding displacement of the other end of the sliding portion 21 on the opposite side of the wing rail 1 to be measured, R b It is the width of the bottom of the wing rail 1.

[0031] It should be noted that, in the present application, the sliding portion 21 is detachably connected to the connecting portion 22. In this way, by providing the follower structure 20 in a split structural form, the convenience of installation and disassembly of the follower structure 20 is ensured.

[0032] Optionally, the sliding portion 21 and the connecting portion 22 are matched in a concave-convex manner.

[0033] Optionally, the sliding portion 21 and the connecting portion 22 are magnetically engaged.

[0034] Optionally, the sliding portion 21 is snap-fitted with the connecting portion 22 .

[0035] Preferably, the connecting portion 22 is made of insulating material to avoid changes in the circuit inside the turnout.

[0036] It should be noted that, in the present application, the support column 10 is detachably connected to the ballast structure 2. In this way, the convenience of installation and removal of the support column 10 is ensured.

[0037] like Figure 1 and Figure 2As shown, the sliding part 21 includes a support beam 211 and two slider structures 212, wherein the connection part 22 is arranged on the surface of the support beam 211 facing the wing rail 1; the two slider structures 212 are respectively slidably arranged on the two support columns 10, and the two slider structures 212 are respectively hingedly matched with the two ends of the support beam 211. In this way, by setting the sliding part 21 to include a support beam 211 and two slider structures 212, wherein the support beam 211 plays a supporting role for the connection part 22 and the wing rail 1, the following stability of the following structure 20 is ensured, and the setting of the two slider structures 212 ensures the sliding reliability and sliding stability of the entire sliding part 21.

[0038] Preferably, at least the surface of the support beam 211 facing the wing rail 1 is a plane.

[0039] Optionally, the support beam 211 is provided with a position scale, which is used to align with the edge of the non-male left side of the wing rail 1 to ensure that the dynamic inclination measuring device of the turnout wing rail can be installed as quickly as possible.

[0040] It should be noted that, in an embodiment of the present application not shown in the figure, the support beam 211 has a receiving cavity, which extends along the length direction of the support beam 211, and contains liquid and bubbles insoluble in the liquid in the receiving cavity, so as to be used for horizontal calibration when installing the support beam 211. In this way, before the wing rail 1 tilts inward, it is ensured that the support beam 211 is in a horizontal state after the dynamic inclination measuring device of the turnout wing rail is installed, thereby ensuring the accuracy of the subsequent measurement of the first sliding distance h1 and the second sliding distance h2.

[0041] like Figure 1 and Figure 2 As shown, the connection part 22 has a limiting groove 221, and the limiting groove 221 is used to accommodate a part of the non-working side of the wing rail 1 to be measured. In this way, the connection reliability between the connection part 22 and the wing rail 1 is ensured.

[0042] It should be noted that in this application, Figure 1 As shown, the space between the two wing rails 1 is used for wheels to pass through, that is, the opposite surfaces of the two wing rails 1 serve as working surfaces, and the opposite surfaces of the two wing rails 1 serve as non-working sides.

[0043] Preferably, the groove contour of the limiting groove 221 is at least adapted to the outer contour of the non-working side for fitting with the groove wall surface of the limiting groove 221. In this way, it is ensured that there is as large a contact surface as possible between the two, thereby ensuring the connection reliability between the two.

[0044] like Figure 1 and Figure 2As shown, the connection portion 22 includes a first beam section 222, a transition section 223, and a second beam section 224 connected to each other, wherein the first beam section 222 and the second beam section 224 are both arranged in the horizontal direction, and the transition section 223 is arranged in the vertical direction, so that the first beam section 222, the transition section 223, and the second beam section 224 surround a C-shaped limiting groove 221. In this way, by setting the connection portion 22 to include the first beam section 222, the transition section 223, and the second beam section 224 connected to each other, it is ensured that the groove contour line of the limiting groove 221 of the connection portion 22 can be adapted to the outer contour line of the groove wall surface of the limiting groove 221.

[0045] Preferably, the length of the first beam section 222 is smaller than the length of the second beam section 224 .

[0046] Preferably, at least the length of the second beam section 224 is equal to the length of the bottom outer surface of the wing rail 1 to be measured. In this way, it is ensured that the second beam section 224 can provide sufficient support for the wing rail 1.

[0047] like Figure 1 and Figure 2 As shown, both support columns 10 have a slide groove 11, and the two ends of the sliding part 21 are respectively slidably arranged in the two slide grooves 11, and the edges of the slide grooves 11 have scale lines 12 for reading the first sliding distance h1 and the second sliding distance h2 of the two ends of the sliding part 21. In this way, it is convenient for maintenance personnel to directly read the first sliding distance h1 and the second sliding distance h2.

[0048] like Figure 3 As shown, the dynamic inclination measuring device of the turnout wing rail also includes a pointer 13, and the pointer 13 is slidably arranged with the support column 10, but the friction between the two is relatively large. When the train passes, the wing rail 1 is deformed under the action of the load, and further the two slider structures 212 slide downward, so that the two slider structures 212 push the pointer 13 on the corresponding side to move downward respectively. After the train passes, the pointer 13 remains stationary, thereby directly reading the first sliding distance h1 and the second sliding distance h2. By manually reading the maximum displacement of the slider structures 212 on both sides, the inclination amount of the wing rail 1 under dynamic conditions is calculated. In addition, this mechanical measurement and reading method is conducive to saving processing and manufacturing costs.

[0049] Of course, in an embodiment of the present application which is not shown in the figure, the support column 10 can also be designed with a contact displacement sensor, and the dynamic displacement of the two slider structures 212 can be directly obtained through the contact displacement sensor.

[0050] It should be noted that, in an embodiment of the present application which is not shown in the figure, the dynamic inclination measuring device of the turnout wing rail also has data storage and wireless transmission functions, and can collect measured data regularly.

[0051] It should be noted that in the present application, the above-mentioned calculation method requires that the turnout wing rail dynamic inclination measuring device be reset after use, including returning the pointer 13 to zero and re-leveling the support beam 211 at the bottom of the wing rail 1 to measure the dynamic inclination of the wing rail 1 when the next train passes.

[0052] It should be noted that in the present application, the installation and use steps of the dynamic inclination measuring device of the turnout wing rail are as follows: the first step is to install the connection part 22 at the throat of the wing rail 1, insert the support beam 211 into the connection part 22, and align the position mark on the support beam 211 with the edge of the non-working side of the rail bottom of the wing rail 1; the second step is to install the support columns 10 on both sides; the third step is to connect the support beam 211 with the two slider structures 212; the fourth step is to level the support beam 211 and return the initial values ​​of the dynamic inclination measuring device of the turnout wing rail to zero. After the train passes, the data of the dynamic inclination measuring device of the turnout wing rail can be read to obtain the maximum displacement of the two slider structures 212 on the left and right sides, and the inclination amount of the wing rail 1 under dynamic conditions can be calculated using the above formula.

[0053] It should be noted that in the present application, when the dynamic inclination measuring device of the turnout wing rail in the present application is used, the dynamic inclination amount of the wing rail 1 can be characterized by measuring the dynamic displacement of the two slider structures 212 on the left and right sides of the wing rail 1. Since the follower structure 20 is connected to the rail bottom of the wing rail 1 to form an integral structure, under the action of the train load, the wing rail 1 undergoes vertical displacement and torsion, driving the follower structure 20 at the rail bottom to produce vertical displacement and rotation. Further, the two slider structures 212 on the left and right sides slide downward, and the sliding amount of the two slider structures 212 on both sides is different due to the torsion. In addition, since the length of the support beam 211 at the rail bottom is much larger than the width of the rail bottom of the wing rail 1, under the action of the lever, the displacement effect produced by the torsion is more obvious, and the inclination amount of the wing rail 1 can be accurately calculated by measuring the vertical displacement of the two slider structures 212. In addition, the dynamic inclination measuring device of the turnout wing rail can be placed in the turnout line for a long time to perform long-term detection on the deformation state of the wing rail 1, and repair it in time when the dynamic displacement or inclination amount is abnormal. Therefore, the dynamic inclination measuring device for high-speed turnout wing rails in the present application effectively solves the problem of unclear dynamic service status of turnout wing rails in the prior art.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0055] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the utility model. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0056] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0059] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A device for measuring the dynamic inclination of a turnout wing rail, characterized in that: include: Two support columns (10), the two support columns (10) being respectively used to be connected to two ballast structures (2) on both sides of the wing rail (1), and the two support columns (10) both extend in a vertical direction; A follower structure (20), the follower structure (20) is located between the two support columns (10), the follower structure (20) comprises a sliding portion (21) and a connecting portion (22), wherein the two ends of the sliding portion (21) are respectively slidably connected to the two support columns (10), the connecting portion (22) is arranged on the surface of the sliding portion (21) on the side facing the wing rail (1), and the connecting portion (22) is used to connect to one of the two wing rails (1), so as to measure a first sliding distance h1 and a second sliding distance h2 of the two ends of the sliding portion (21) sliding on the corresponding support columns (10) when the wing rail (1) to be measured is tilted inward.

2. The turnout wing rail dynamic inclination measuring device according to claim 1, characterized in that: The sliding portion (21) is detachably connected to the connecting portion (22).

3. The device for measuring the dynamic inclination of a turnout wing rail according to claim 1, characterized in that: The support column (10) is detachably connected to the track bed structure (2).

4. The device for measuring the dynamic inclination of a turnout wing rail according to claim 1, characterized in that: The sliding part (21) comprises: A support beam (211), wherein the connection portion (22) is arranged on a surface of the support beam (211) facing the wing rail (1); Two slider structures (212), the two slider structures (212) are respectively slidably arranged on the two support columns (10), and the two slider structures (212) are respectively hingedly matched with two ends of the support beam (211).

5. The device for measuring the dynamic inclination of a turnout wing rail according to claim 4, characterized in that: The support beam (211) has a receiving cavity, the receiving cavity extends along the length direction of the support beam (211), and the receiving cavity contains liquid and bubbles insoluble in the liquid, so as to be used for horizontal calibration when installing the support beam (211).

6. The device for measuring the dynamic inclination of a turnout wing rail according to claim 1, characterized in that: The connecting portion (22) has a limiting groove (221), and the limiting groove (221) is used to accommodate a portion of the non-working side of the wing rail (1) to be measured.

7. The device for measuring the dynamic inclination of a turnout wing rail according to claim 6, characterized in that: The groove contour line of the limiting groove (221) is at least adapted to the outer contour line of the non-working side used for fitting with the groove wall surface of the limiting groove (221).

8. The device for measuring the dynamic inclination of a turnout wing rail according to claim 6, characterized in that: The connecting portion (22) comprises a first beam section (222), a transition section (223) and a second beam section (224) which are connected to each other, wherein the first beam section (222) and the second beam section (224) are both arranged in a horizontal direction, and the transition section (223) is arranged in a vertical direction, so that the first beam section (222), the transition section (223) and the second beam section (224) form a C-shaped limiting groove (221).

9. The device for measuring the dynamic inclination of a turnout wing rail according to claim 8, characterized in that: The length of the first beam section (222) is smaller than the length of the second beam section (224).

10. The device for measuring the dynamic inclination of a turnout wing rail according to claim 8, characterized in that: At least the length of the second beam section (224) is equal to the length of the bottom outer surface of the wing rail (1) to be measured.

11. The device for measuring the dynamic inclination of a turnout wing rail according to any one of claims 1 to 10, characterized in that: The two support columns (10) each have a slide groove (11), and the two ends of the sliding portion (21) are respectively slidably arranged in the two slide grooves (11), and the edges of the slide grooves (11) have scale lines (12) for reading the first sliding distance h1 and the second sliding distance h2 at the two ends of the sliding portion (21).

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