Punching test fixture

Abstract

The utility model discloses a perforation test fixture, which comprises an upper clamping seat and a lower clamping seat, a first groove is formed in the upper part of the upper clamping seat; a first clamping block is arranged in the first groove; a first through hole is formed in the middle of the first clamping block; the first through hole penetrates through the upper clamping seat; the lower end face of the first clamping block is provided with an annular groove surrounding the first through hole. A lower clamping seat is arranged below the upper clamping seat; a second groove is formed in the upper part of the lower clamping seat; a second clamping block is arranged in the second groove; a second through hole is formed in the middle of the second clamping block; the second through hole penetrates through the lower clamping seat; an annular protruding block is arranged on the upper end face of the second clamping block around the second through hole. The annular protruding block is used for being matched with the annular groove to clamp the sample. According to the perforation test fixture, the tightness between the fixtures is improved, the fixtures are easy to replace after being abraded, the test requirements of samples with different sizes and specifications can be met, the processing cost is reduced, and the test efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of plate performance testing, in particular to a perforation test fixture. Background Art

[0002] Different materials will show ever-changing forms and complex and multifaceted behavioral properties under different environmental conditions. The materials used in the automotive industry are rich and diverse, from common plastics and metals to the recently popular lightweight and high-strength composite materials. The structure and components of the car are complex and precise, and are used in different parts with various topological shapes, so the materials used also need to reflect completely different characteristics. Especially when a car collides, many automotive materials such as high-strength steel, plastics, composite materials, etc. will suffer varying degrees of compression deformation, which can lead to material failure and fracture in severe cases. Therefore, it is necessary to obtain the mechanical behavior of materials under different stress states through experimental means, evaluate the performance characteristics of materials under different environmental conditions, and provide strong support for automotive structural design and safety performance evaluation.

[0003] The perforation test is to apply a load to the test piece fixed on the die through a hemispherical indenter to make it break. It is used to evaluate the mechanical properties of the material under a biaxial stress state (i.e., stress triaxiality is 0.66), i.e., the impact resistance under quasi-static or high-speed impact loads. The toughness, fracture, and energy absorption performance parameters of the material can be obtained. These parameters are of great significance for automobile structural design, collision simulation, and safety performance evaluation. The Chinese patent with announcement number CN214150173U discloses a sample clamping and fixing device for cupping test. Since the first clamping seat and the second clamping seat are provided with fixing holes, the first clamping seat and the second clamping seat and the sample plate are tightly fixed by bolts, which solves the problem of relative sliding between the plate sample and the mold due to the insufficient fit between the die and the blank holder in the prior art. The first clamping seat and the second clamping seat are relatively tight, and the sample plate is not easy to slide relative to each other during the experiment, which ensures the success of the experiment and the accuracy of the experimental data results.

[0004] The sample clamping and fixing device for the cupping test improves the tightness of the first clamping seat and the second clamping seat by bolts, but under the huge impact force, due to the small friction between the sample and the mold, there will still be cracking or relative sliding between the sample and the mold. Moreover, after repeated tests, the first clamping seat and the second clamping seat of the clamping and fixing device will constantly rub against the sample, and the clamping seat will have a certain degree of wear. The wear is mainly concentrated around the through hole. Later, the entire clamping seat needs to be replaced, which is not only difficult to replace, but also costly, which is also a problem that needs to be solved urgently. Utility Model Content

[0005] The purpose of the utility model is to provide a perforation test fixture to solve the above-mentioned shortcomings, solve the problem of relative sliding between the sample and the fixture, further improve the tightness between the fixtures, and facilitate replacement of the fixtures after wear. It can also meet the test of samples of different sizes and specifications, reduce processing costs, and improve test efficiency. To achieve the above-mentioned purpose, the utility model provides the following technical solutions:

[0006] A perforation test fixture comprises an upper clamping seat and a lower clamping seat; the upper portion of the upper clamping seat is provided with a first groove; a first clamping block is provided in the first groove; a first through hole is provided in the middle portion of the first clamping block; the first through hole passes through the upper clamping seat; an annular groove is provided around the first through hole on the lower end surface of the first clamping block; a lower clamping seat is provided below the upper clamping seat; a second groove is provided on the upper portion of the lower clamping seat; a second clamping block is provided in the second groove; a second through hole is provided in the middle portion of the second clamping block; the second through hole passes through the lower clamping seat; an annular protrusion is provided around the second through hole on the upper end surface of the second clamping block; the annular protrusion is used to cooperate with the annular groove to clamp the sample.

[0007] Furthermore, the upper clamping seat is provided with a plurality of fixing holes around it; the fixing holes penetrate the upper clamping seat; threaded holes are provided at positions of the lower clamping seat corresponding to the fixing holes; and bolts are penetrated through the fixing holes and the threaded holes.

[0008] Furthermore, it also includes a pressure head; a pressure head is arranged above the upper clamping seat; the end of the pressure head close to the upper clamping seat is hemispherical, and the other end is provided with a thread; the pressure head is connected to the test equipment through the thread.

[0009] Furthermore, the surface of the pressure head at the end close to the upper clamping seat is nitrided.

[0010] Furthermore, it also includes a base; the base is provided with third grooves of different sizes; the third groove is used to place the lower clamping seat; the lower clamping seat is provided with at least two positioning holes; the base is provided with positioning pins corresponding to the positioning holes one by one.

[0011] Furthermore, a test device is connected to the lower end of the base.

[0012] The beneficial effects of the utility model are:

[0013] The utility model discloses a perforation test fixture, including an upper clamping seat and a lower clamping seat; the upper part of the upper clamping seat is provided with a first groove; the first groove is provided with a first clamping block; the middle part of the first clamping block is provided with a first through hole; the first through hole penetrates the upper clamping seat; the lower end surface of the first clamping block is provided with an annular groove around the first through hole; the lower clamping seat is provided below the upper clamping seat; the upper part of the lower clamping seat is provided with a second groove; the second groove is provided with a second clamping block; the middle part of the second clamping block is provided with a second through hole; the second through hole penetrates the lower clamping seat; the upper end surface of the second clamping block is provided with an annular protrusion around the second through hole; the annular groove is used to cooperate with the annular protrusion to clamp the sample. The utility model discloses a perforation test fixture, which is clamped by the annular groove, the annular protrusion and the bolts to clamp the upper clamping seat and the lower clamping seat. When the fixture is worn, it is easy to replace, and it can also meet the test of samples of different sizes, reduce processing costs, and improve test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0015] Figure 2 It is a three-dimensional structural schematic diagram of the upper clamping seat and the first clamping block of the utility model;

[0016] Figure 3 It is a three-dimensional structural schematic diagram of the upper clamping seat of the utility model;

[0017] Figure 4 It is a three-dimensional structural schematic diagram of the lower clamping seat and the second clamping block of the utility model;

[0018] Figure 5 It is a three-dimensional structural schematic diagram of the lower clamping seat of the utility model;

[0019] In the accompanying drawings: 1-upper clamping seat, 2-lower clamping seat, 3-first groove, 4-first clamping block, 5-first through hole, 6-annular protrusion, 7-second groove, 8-second clamping block, 9-second through hole, 10-annular groove, 11-threaded hole, 12-pressing head, 13-base, 14-third groove, 15-positioning hole, 16-fixing hole. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.

[0021] Embodiment 1:

[0022] See attached Figures 1 to 5. A perforation test fixture comprises an upper clamping seat 1 and a lower clamping seat 2; a first groove 3 is provided on the upper part of the upper clamping seat 1; a first clamping block 4 is provided in the first groove 3; a first through hole 5 is provided in the middle of the first clamping block 4; the first through hole 5 passes through the upper clamping seat 1; an annular groove 10 is provided on the lower end surface of the first clamping block 4 around the first through hole 5; a lower clamping seat 2 is provided below the upper clamping seat 1; a second groove 7 is provided on the upper part of the lower clamping seat 2; a second clamping block 8 is provided in the second groove 7; a second through hole 9 is provided in the middle of the second clamping block 8; the second through hole 9 passes through the lower clamping seat 2; an annular protrusion 6 is provided on the upper end surface of the second clamping block 8 around the second through hole 9; the annular protrusion 6 is used to cooperate with the annular groove 10 to clamp the sample. From the above structure, it can be known that a perforation test fixture comprises an upper clamping seat 1 and a lower clamping seat 2, the upper clamping seat 1 is located above the lower clamping seat 2, and the upper clamping seat 1 and the lower clamping seat 2 are both square, have the same size, and are aligned. The upper clamping seat 1 is provided with a first groove 3, and a first clamping block 4 is provided in the first groove 3. A plurality of threaded holes can be provided on the first clamping block 4. The upper clamping seat 1 is provided with fixing holes at positions corresponding to these threaded holes. Bolts pass through the fixing holes and enter the threaded holes to cooperate with the threads to fix the first clamping block 4 in the first groove 3. A first through hole 5 is provided in the middle of the first clamping block 4. The first through hole 5 extends upward and passes through the upper clamping seat 1. An annular groove 10 is provided around the first through hole 5 on the lower end surface of the first clamping block 4; the lower clamping seat 2 is provided with a second groove 7. A second clamping block 8 is provided in the second groove 7. A plurality of threaded holes can be provided on the second clamping block 8. The lower clamping seat 2 is provided with fixing holes at positions corresponding to these threaded holes. Bolts pass through the fixing holes and enter the threaded holes to cooperate with the threads to fix the second clamping block 8 in the second groove 7. The second clamp block 8 corresponds to the first clamp block 4, and both the second clamp block 8 and the first clamp block 4 are nitrided to improve the hardness and wear resistance of both and extend their service life. A second through hole 9 is provided in the middle of the second clamp block 8. The second through hole 9 has the same size as the first through hole 5. The second through hole 9 extends downward and passes through the lower clamping seat 2 and is coaxial with the first through hole 5. An annular protrusion 6 is provided around the second through hole 9 on the upper end surface of the second clamp block 8. The annular groove 10 and the annular protrusion 6 can cooperate to fix and clamp the sample between the upper clamping seat 1 and the lower clamping seat 2. During the test, due to the friction between the sample and the upper clamping seat 1 and the lower clamping seat 2, after repeated tests, the upper clamping seat 1 and the lower clamping seat 2 will have different degrees of wear, and such wear mainly exists around the first through hole 5 and the second through hole 9. Therefore, grooves are respectively provided on the upper clamping seat 1 and the lower clamping seat 2, and clamping blocks are provided in the grooves. In this way, when the clamping blocks are worn, only the first clamping block 4 and the second clamping block 8 in the middle need to be replaced, and there is no need to replace the entire clamping seat. In addition, only the second clamping block 8 and the first clamping block 4 need to be nitrided accordingly, and there is no need to nitride the entire clamping seat, thereby saving costs.The utility model provides a perforation test fixture, wherein the annular groove 10 cooperates with the annular protrusion 6 to fix and clamp the sample between the upper clamping seat 1 and the lower clamping seat 2. When the fixture is worn, it is easy to replace, which reduces the processing cost.

[0023] Embodiment 2:

[0024] See attached Figures 1 to 5 . On the basis of the first embodiment, the upper clamping seat 1 is provided with a plurality of fixing holes 16 around it; the fixing holes 16 penetrate the upper clamping seat 1; the lower clamping seat is provided with a threaded hole 11 at a position corresponding to the fixing hole 16; and the fixing hole 16 and the threaded hole 11 are both provided with penetrating bolts. It can be known from the above structure that a plurality of fixing holes 16 are evenly provided around the first clamping block 4 on the upper clamping seat 1 at a certain distance from the first clamping block 4, the fixing hole 16 penetrates the upper clamping seat 1, and a threaded hole 11 is provided on the lower clamping seat 2 at a position corresponding to the fixing hole 16 on the upper clamping seat 1. The bolt passes through the fixing hole 16 and enters the threaded hole 11 to cooperate with the thread, so as to further relatively fix the upper clamping seat 1 and the lower clamping seat 2 and clamp the sample to be tested.

[0025] It also includes a pressure head 12; a pressure head 12 is arranged above the upper clamping seat 1; the end of the pressure head 12 close to the upper clamping seat 1 is hemispherical, and the other end is provided with a thread; the pressure head 12 is connected to the test equipment through the thread. As can be seen from the above structure, it also includes a pressure head 12, which is arranged above the upper clamping seat 1, is cylindrical, coaxial with the first through hole 5 and the second through hole 9, and has a cross-sectional size smaller than the first through hole 5. It can freely pass through the first through hole 5 and the second through hole 9. The cross-sectional size diameter of the pressure head 12 is preferably the diameter of the first through hole 5 minus 1.5 to 2 mm, so that the test results are convenient for benchmarking the simulation results, because when doing the corresponding simulation, it is to ensure that the deformation area of ​​the sample is within the first through hole 5, and the test accuracy is also improved. The end close to the upper clamping seat 1 is hemispherical, and the other end is provided with a thread. The pressure head 12 is connected to the test equipment through the thread. During the test, the pressure head 12 presses the sample into the second through hole 9 of the lower clamping seat 2 at a preset speed under the action of the test equipment.

[0026] The surface of the indenter 12 near the upper clamping seat 1 is nitrided. As can be seen from the above structure, the indenter 12 near the upper clamping seat 1 is hemispherical, and its surface is nitrided to make its surface hardness HV ≥ 950, and the core hardness HRC--38~42, which improves the life of the indenter 12 while ensuring the toughness of its core, avoiding the indenter 12 from breaking during the test, especially at a high strain rate; it can also make the surface roughness Ra ≤ 0.1μm, reduce the friction between the indenter 12 and the sample, and improve the test accuracy.

[0027] Embodiment three:

[0028] See attached Figures 1 to 5 . On the basis of the second embodiment, it also includes a base 13; the base 13 is provided with a third groove 14 of different sizes; the third groove 14 is used to place the lower clamping seat 2; the lower clamping seat 2 is provided with at least two positioning holes 15; the base 13 is provided with positioning pins corresponding to the positioning holes 15. It can be seen from the above structure that the perforation test fixture also includes a base 13, the base 13 is provided with a third groove 14 of different sizes, the lower clamping seat 2 is placed in the third groove 14, the third grooves 14 of different sizes are continuously arranged, the third grooves 14 are through the base 13 in the longitudinal direction of the base 13, and there are side walls on both sides in the horizontal direction to limit the lower clamping seat 2, the third grooves 14 of different sizes are stepped upward in the horizontal direction of the base 13, and the third grooves 14 of different sizes are used to place the lower clamping seat 2 of different sizes. When the size of the test sample to be tested changes, the base 13 does not need to be replaced, and the lower clamping seat 2 of the corresponding size is directly installed on the base 13. A perforation test fixture of the utility model can meet the needs of testing samples of different sizes. At least two positioning holes 15 are provided on the lower clamping seat 2. The positioning holes 15 can be set on the diagonal of the lower clamping seat 2 and are located near the edge of the lower clamping seat 2. Positions corresponding to the positioning holes 15 of the lower clamping seat 2 are provided with positioning pins on the base 13. The positioning pins and the positioning holes 15 cooperate to fix the lower clamping seat 2 on the base 13. When the lower clamping seat 2 needs to be replaced, it can be directly taken out to improve the test efficiency. A through hole is provided at the position of the base 13 corresponding to the second through hole 9 of the lower clamping seat 2. The size of the through hole is greater than or equal to the size of the second through hole 9, and the axis is the same.

[0029] The lower end of the base 13 is connected to a test device. As can be seen from the above structure, the base 13 and the test device are both provided with corresponding threaded holes, and matching bolts are arranged in the threaded holes, and the threaded holes and the bolts cooperate to fix the base 13 on the test device.

[0030] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the patent scope of the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein with equivalents. 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 perforation test fixture, comprising an upper clamping seat (1) and a lower clamping seat (2); characterized in that: The upper portion of the upper clamping seat (1) is provided with a first groove (3); a first clamping block (4) is provided in the first groove (3); a first through hole (5) is provided in the middle of the first clamping block (4); the first through hole (5) passes through the upper clamping seat (1); an annular groove (10) is provided on the lower end surface of the first clamping block (4) around the first through hole (5); a lower clamping seat (2) is provided below the upper clamping seat (1); a second groove (7) is provided on the upper portion of the lower clamping seat (2); a second clamping block (8) is provided in the second groove (7); a second through hole (9) is provided in the middle of the second clamping block (8); the second through hole (9) passes through the lower clamping seat (2); an annular protrusion (6) is provided on the upper end surface of the second clamping block (8) around the second through hole (9); the annular protrusion (6) is used to cooperate with the annular groove (10) to clamp the sample.

2. A perforation test fixture according to claim 1, characterized in that: The upper clamping seat (1) is provided with a plurality of fixing holes (16) around its periphery; the fixing holes (16) penetrate the upper clamping seat (1); threaded holes (11) are provided at positions of the lower clamping seat corresponding to the fixing holes (16); and bolts are provided penetrating therein.

3. A perforation test fixture according to claim 2, characterized in that: It also includes a pressure head (12); a pressure head (12) is provided above the upper clamping seat (1); the end of the pressure head (12) close to the upper clamping seat (1) is hemispherical, and the other end is provided with a thread; the pressure head (12) is connected to the test equipment via the thread.

4. A perforation test fixture according to claim 3, characterized in that: The surface of the pressure head (12) at the end close to the upper clamping seat (1) is nitrided.

5. A perforation test fixture according to claim 3, characterized in that: It also comprises a base (13); the base (13) is provided with third grooves (14) of different sizes; the third groove (14) is used to place the lower clamping seat (2); the lower clamping seat (2) is provided with at least two positioning holes (15); the base (13) is provided with positioning pins corresponding to the positioning holes one by one.

6. A perforation test fixture according to claim 5, characterized in that: The lower end of the base (13) is connected to a test device.

Images