Self-centering uniform load holding test device
By designing self-centering fixtures and threaded fixtures in the load-keeping test device, the problem of uneven force applied to the thread samples with larger head diameters during the test is solved, and more accurate test data is achieved.
Patent Information
- Application Number
- CN202421077854.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-16
- Publication Date
- 2025-04-04
- Estimated Expiration
- 2034-05-16
AI Technical Summary
When the existing load-keeping test device tests a thread sample with a larger head diameter, the axial force deviation leads to uneven force, which easily leads to test failure.
A self-centered uniform load-holding test device is designed, using upper self-centered fixture and lower self-centered fixture, combined with threaded fixtures to ensure that the threaded head is subjected to uniform force during the test.
Through the design of a self-centering fixture, the influence on the bolts to be inspected can be reduced when there is a deviation between the upper test machine chuck and the lower test machine chuck, making the bolts more uniform in force and the test data more accurate.
Smart Images
Figure CN222719286U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of experimental detection technology, and in particular to a self-centering uniform load holding test device. Background Art
[0002] The proof load test, also known as the guaranteed load test, is a test used to evaluate whether threaded products (such as bolts, nuts, etc.) will undergo significant plastic deformation when subjected to an ultimate load. The main purpose of this test is to verify whether the threaded product has sufficient strength and stability when subjected to a predetermined load to ensure that it can work safely and reliably in actual use.
[0003] According to the provisions of 9.6 of GB / T3098.1-2010 standard for guaranteed load test, refer to Figure 3 After the test is unloaded, the total length l1 of the fastener sample should be the same as l0 before loading (its tolerance ±12.5um is the allowable measurement error). ±12.5um (±0.0125mm) is a very precise and fine size that can only be measured on a micrometer platform. However, there is a certain large deviation in the coaxiality of the axial tension of the tensile test equipment. When testing some parts with larger head diameters, the test force is not on the axis of the part, resulting in uneven force on the head bearing surface, causing oblique pulling of the part head and plastic deformation, which exceeds the deformation of ±12.5um, causing the test to fail easily. At this stage, many test laboratories use the method of calibrating the coaxiality of the test equipment to adjust the test equipment, but when encountering "samples with oversized head diameters", there will still be deviations in the axial force, resulting in inaccurate and failed tests. Utility Model Content
[0004] In view of this, the present application proposes a self-centering uniform load holding test device to improve the accuracy of detection.
[0005] According to one aspect of the present application, there is provided a self-centering uniform load holding test device, comprising: an upper test machine chuck, the upper test machine chuck being adapted to be connected to a top output end of a test machine and to move up and down in a vertical direction;
[0006] A lower testing machine chuck, which is suitable for connecting to the bottom output end of the testing machine and moving up and down in the vertical direction;
[0007] A threaded clamp, the threaded clamp is clamped on the lower testing machine chuck, and the threaded clamp is provided with a clamping threaded hole, and the opening direction of the clamping threaded hole is the same as the moving direction of the lower testing machine chuck;
[0008] A lower self-centering fixture, wherein the lower self-centering fixture is clamped on the upper test chuck, and the lower self-centering fixture is provided with a lower clamping hole, and the top of the lower clamping hole is recessed toward the bottom with a spherical mounting groove;
[0009] The upper self-centering fixture is a hemispherical structure, which matches the mounting groove, and the upper self-centering fixture is provided with an upper clamping hole, which corresponds to the lower clamping hole.
[0010] In one possible implementation, the lower clamping hole is located at the center of the lower self-centering fixture;
[0011] The upper clamping hole is located at the center of the upper self-centering fixture;
[0012] The cross-sectional diameter of the lower clamping hole is greater than the cross-sectional diameter of the upper clamping hole.
[0013] In one possible implementation, the curvature of the upper self-centering fixture is greater than the curvature of the mounting groove.
[0014] In a possible implementation, the lower self-centering fixture is a plate-like structure with a preset thickness, and the lower clamping hole is provided on the plate surface of the lower self-centering fixture; the upper self-centering fixture is a plate-like structure with a preset thickness, and the upper clamping hole is provided on the plate surface of the upper self-centering fixture;
[0015] The cross sections of the upper clamping hole and the lower clamping hole are both circular.
[0016] In a possible implementation, the upper clamping hole, the lower clamping hole and the clamping threaded hole are coaxially arranged.
[0017] In a possible implementation, the top cross-sectional diameter of the upper self-centering fixture is adapted to be larger than the bolt head diameter of the bolt to be inspected.
[0018] In a possible implementation, the upper self-centering fixture is embedded in the interior of the upper testing machine chuck and corresponds to the upper through hole of the upper testing machine chuck.
[0019] In a possible implementation, the threaded clamp is embedded in the lower testing machine chuck, passes through the lower through hole of the lower testing machine chuck, and extends to the upper through hole of the upper testing machine chuck.
[0020] In one possible implementation, the lower self-centering fixture and the upper self-centering fixture are both symmetrical structures.
[0021] In a possible implementation, the cross-sectional diameter of the mounting groove is larger than the cross-sectional diameter of the upper self-centering fixture;
[0022] The depth of the mounting groove is less than a preset thickness of the upper self-centering fixture.
[0023] The beneficial effects of the self-centering uniform load holding test device of the embodiment of the present application are as follows: the self-centering clamp includes a lower self-centering clamp and an upper self-centering clamp, which can fix the threaded head located at the internal thread of the upper testing machine chuck, and the contact side of the lower self-centering clamp and the upper self-centering clamp are both hemispherical structures, so that when the testing machine head drags the bolt through the upper testing machine chuck and the lower testing machine chuck, even if the upper testing machine chuck and the lower testing machine chuck deviate in the vertical direction, it can reduce the impact on the bolt to be inspected, so that the bolt to be inspected is subjected to more uniform force and the test data is more accurate. Specifically, the upper testing machine chuck is used to clamp the lower self-centering fixture and the upper self-centering fixture, the lower testing machine chuck is used to clamp the threaded fixture, and the bolt is then passed through the upper self-centering fixture, the lower self-centering fixture and the threaded fixture in turn, and connected with the internal thread of the threaded fixture, the upper testing machine chuck and the lower testing machine chuck are dragged in opposite directions, the self-centering fixture is against the bolt head of the bolt, and the threaded fixture fixes the screw body of the bolt, when the bolt is dragged in the opposite direction, since the contact surface between the lower self-centering chuck and the upper self-centering chuck is a concave hemispherical structure, and the contact surface between the upper self-centering chuck and the lower self-centering chuck is a protruding hemispherical structure, even if there is a small deviation between the upper testing machine chuck and the lower testing machine chuck in the vertical direction, the arc-shaped contact surface can make the force on the bolt more uniform, so that more accurate data can be obtained.
[0024] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.
[0026] Figure 1 A cross-sectional schematic diagram showing a self-centering uniform load holding test device according to an embodiment of the present application;
[0027] Figure 2 A partial cross-sectional schematic diagram showing a self-centering uniform load holding test device according to an embodiment of the present application;
[0028] Figure 3 A schematic diagram of the background technology of this application is shown. DETAILED DESCRIPTION
[0029] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.
[0030] Among them, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.
[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 the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0032] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
[0033] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.
[0034] See also Figure 1 and Figure 2The self-centering uniform load holding test device of the embodiment of the present application comprises: an upper testing machine chuck 110, a lower testing machine chuck 120, a threaded clamp 300, a lower self-centering clamp 220 and an upper self-centering clamp 210. The upper testing machine chuck 110 is used to connect the top output end of the testing machine and move up and down in the vertical direction. The lower testing machine chuck 120 is used to connect the bottom output end of the testing machine and move up and down in the vertical direction. The threaded clamp 300 is clamped in the lower testing machine chuck 120, and the threaded clamp 300 is opened. A clamping threaded hole is provided, and the opening direction of the clamping threaded hole is the same as the moving direction of the lower testing machine chuck 120. The lower self-centering fixture 220 is clamped on the upper testing machine chuck 110, and the lower self-centering fixture 220 is provided with a lower clamping hole 221, and the top of the lower clamping hole 221 is recessed with a spherical mounting groove toward the bottom. The upper self-centering fixture 210 is a hemispherical structure that matches the mounting groove, and the upper self-centering fixture 210 is provided with an upper clamping hole 211, and the upper clamping hole 211 corresponds to the lower clamping hole 221.
[0035] In this embodiment, the self-centering clamp includes a lower self-centering clamp 220 and an upper self-centering clamp 210, which can fix the threaded head located at the internal thread of the upper testing machine chuck 110, and the side where the lower self-centering clamp 220 and the upper self-centering clamp 210 contact each other are both hemispherical structures, so that when the testing machine head drags the bolt through the upper testing machine chuck 110 and the lower testing machine chuck 120, even if the upper testing machine chuck 110 and the lower testing machine chuck 120 deviate in the vertical direction, the impact on the bolt to be inspected can be reduced, so that the bolt to be inspected can be subjected to more uniform force and the test data can be more accurate. Specifically, the upper testing machine chuck 110 is used to clamp the lower self-centering fixture 220 and the upper self-centering fixture 210, and the lower testing machine chuck 120 is used to clamp the threaded fixture 300, and then the bolt is passed through the upper self-centering fixture 210, the lower self-centering fixture 220 and the threaded fixture 300 in sequence, and connected with the internal thread of the threaded fixture 300, the upper testing machine chuck 110 and the lower testing machine chuck 120 are dragged in opposite directions, the self-centering fixture is against the bolt head of the bolt, and the threaded fixture 300 fixes the screw body of the bolt. When the bolt is dragged in the opposite direction, since the contact surface between the lower self-centering chuck and the upper self-centering chuck is a concave hemispherical structure, and the contact surface between the upper self-centering chuck and the lower self-centering chuck is a protruding hemispherical structure, even if there is a small deviation between the upper testing machine chuck 110 and the lower testing machine chuck 120 in the vertical direction, the arc-shaped contact surface can make the force on the bolt more uniform, so that more accurate data can be obtained.
[0036] It should be noted that the testing machine, the testing machine chuck and the threaded clamp 300 are existing technologies. This application optimizes the threaded clamp 300 located inside the upper testing machine chuck 110 to make the data of the bolt more accurate during detection. Therefore, the testing machine, the testing machine chuck and the threaded clamp 300 will not be described in detail.
[0037] Among them, the testing machine chuck is a hollow structure, and a through hole is opened on the side away from the output end, so that the threaded clamp 300 with a boss structure is arranged inside the lower testing machine chuck 120, and extends to the outside of the lower testing machine chuck 120, and is abutted and fixed inside the lower testing machine chuck 120, and the upper self-centering chuck and the lower self-centering chuck are arranged inside the upper testing machine chuck 110, corresponding to the through hole opened in the upper testing machine chuck 110, and are abutted and fixed with the inner side of the upper testing machine chuck 110.
[0038] In a specific embodiment, the lower clamping hole 221 is located at the center of the lower self-centering fixture 220, the upper clamping hole 211 is located at the center of the upper self-centering fixture 210, and the cross-sectional diameter of the lower clamping hole 221 is larger than the cross-sectional diameter of the upper clamping hole 211, so that the upper self-centering fixture 210 can be stably set on the top of the lower self-centering fixture 220. Specifically, since one side of the upper self-centering fixture 210 body is a hemispherical structure, it contacts the concave side of the top of the lower self-centering fixture 220, and since the cross-sectional diameter of the lower clamping hole 221 is larger than the cross-sectional diameter of the upper clamping hole 211, at this time, the arc-shaped side wall of the upper self-centering fixture 210 can be partially located inside the lower clamping hole 221.
[0039] In a specific embodiment, the curvature of the upper self-centering clamp 210 is greater than the curvature of the mounting groove, which can ensure that the upper self-centering clamp 210 can rotate inside the mounting groove at the top of the lower self-centering clamp 220. Specifically, the cross-sectional diameter of the lower clamping hole 221 is greater than the cross-sectional diameter of the upper clamping hole 211, so that the arc-shaped side wall of the upper self-centering clamp 210 can be partially located inside the lower clamping hole 221, thereby improving the relative stability of the upper self-centering clamp 210 and the lower self-centering clamp 220. During the test, even if the upper testing machine chuck 110 and the lower testing machine chuck 120 have a small deviation in the vertical direction during the dragging process, the side of the upper self-centering clamp 210 with a hemispherical structure rotates relative to the mounting groove of the hemispherical side of the lower self-centering clamp 220, thereby reducing the force in the vertical direction of the bolt length.
[0040] In a specific embodiment, the lower self-centering fixture 220 is a plate-like structure with a preset thickness, and the lower clamping hole 221 is opened on the plate surface of the lower self-centering fixture 220. The upper self-centering fixture 210 is a plate-like structure with a preset thickness, and the upper clamping hole 211 is opened on the plate surface of the upper self-centering fixture 210. The cross-sections of the upper clamping hole 211 and the lower clamping hole 221 are both circular, and the diameters are slightly larger than the diameter of the bolt to be tested, which is convenient for bolt insertion testing.
[0041] In a specific embodiment, the upper clamping hole 211, the lower clamping hole 221 and the clamping threaded hole are coaxially arranged.
[0042] In a specific embodiment, the top cross-sectional diameter of the upper self-centering fixture 210 is larger than the bolt head diameter of the bolt to be inspected, so that the top of the upper self-centering fixture 210 can be against the bolt head of the bolt and dragged away from the lower self-centering fixture 220.
[0043] In a specific embodiment, the upper self-centering fixture 210 is embedded in the upper testing machine chuck 110, corresponding to the upper through hole of the upper testing machine chuck 110, and the threaded fixture 300 is embedded in the lower testing machine chuck 120, passes through the lower through hole of the lower testing machine chuck 120, and extends to the upper through hole of the upper testing machine chuck 110. In this way, the threaded fixture 300 is extended to detect shorter bolts.
[0044] In a specific embodiment, the lower self-centering fixture 220 and the upper self-centering fixture 210 are both symmetrical structures to ensure that the bolts are evenly stressed during the pulling process.
[0045] In a specific embodiment, the cross-sectional diameter of the mounting groove is larger than the cross-sectional diameter of the upper self-centering clamp 210 , and the depth of the mounting groove is less than the preset thickness of the upper self-centering clamp 210 , further enabling the upper self-centering clamp 210 to rotate inside the mounting groove of the lower self-centering clamp 220 .
[0046] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. A self-centering uniform load holding test device, characterized in that: include: An upper testing machine chuck, which is suitable for connecting to the top output end of the testing machine and moving up and down in the vertical direction; A lower testing machine chuck, which is suitable for connecting to the bottom output end of the testing machine and moving up and down in the vertical direction; A threaded clamp, the threaded clamp is clamped on the lower testing machine chuck, and the threaded clamp is provided with a clamping threaded hole, and the opening direction of the clamping threaded hole is the same as the moving direction of the lower testing machine chuck; A lower self-centering fixture, wherein the lower self-centering fixture is clamped on the upper testing machine chuck, and the lower self-centering fixture is provided with a lower clamping hole, and the top of the lower clamping hole is recessed toward the bottom with a spherical mounting groove; The upper self-centering fixture is a hemispherical structure, which matches the mounting groove, and the upper self-centering fixture is provided with an upper clamping hole, which corresponds to the lower clamping hole.
2. The self-centering uniform load holding test device according to claim 1, characterized in that: The lower clamping hole is located at the center of the lower self-centering fixture; The upper clamping hole is located at the center of the upper self-centering fixture; The cross-sectional diameter of the lower clamping hole is greater than the cross-sectional diameter of the upper clamping hole.
3. The self-centering uniform load holding test device according to claim 2, characterized in that: The curvature of the upper self-centering fixture is greater than the curvature of the mounting groove.
4. The self-centering uniform load holding test device according to any one of claims 1 to 3, characterized in that: The lower self-centering fixture is a plate-like structure with a preset thickness, and the lower clamping hole is provided on the plate surface of the lower self-centering fixture; the upper self-centering fixture is a plate-like structure with a preset thickness, and the upper clamping hole is provided on the plate surface of the upper self-centering fixture; The cross sections of the upper clamping hole and the lower clamping hole are both circular.
5. The self-centering uniform load holding test device according to claim 4, characterized in that: The upper clamping hole, the lower clamping hole and the clamping threaded hole are coaxially arranged.
6. The self-centering uniform load holding test device according to claim 4, characterized in that: The top cross-sectional diameter of the upper self-centering fixture is suitable to be larger than the bolt head diameter of the bolt to be tested.
7. The self-centering uniform load holding test device according to claim 1, characterized in that: The upper self-centering fixture is embedded in the upper testing machine chuck and corresponds to the upper through hole of the upper testing machine chuck.
8. The self-centering uniform load holding test device according to claim 7, characterized in that: The threaded clamp is embedded in the lower testing machine chuck, passes through the lower through hole of the lower testing machine chuck, and extends to the upper through hole of the upper testing machine chuck.
9. The self-centering uniform load holding test device according to claim 1, characterized in that: The lower self-centering fixture and the upper self-centering fixture are both symmetrical structures.
10. The self-centering uniform load holding test device according to claim 4, characterized in that: The cross-sectional diameter of the mounting groove is larger than the cross-sectional diameter of the upper self-centering fixture; The depth of the mounting groove is less than a preset thickness of the upper self-centering fixture.