Metal bar shearing test clamp

Abstract

The utility model relates to a metal bar shear test fixture. The test fixture comprises a pressure head and a base, the pressure head comprises an upper fixing column and a shearing assembly connected to the lower end of the upper fixing column, the upper fixing column is detachably matched with a movable cross beam of an external mechanical testing machine, and the shearing assembly comprises a shearing rod extending in the vertical direction and a shearing ring allowing a metal bar sample to enter and exit. The shearing rod is provided with a first installation hole which is through in the transverse direction so that the shearing ring can be installed in the first installation hole, and clearance fit between the shearing ring and the shearing rod is achieved. In the test fixture, the pressure head and the base are vertically connected to solve the problem that the fixture mounting seat occupies a large space, and meanwhile, consumables are reduced, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of metal materials, and particularly relates to a shearing test fixture for metal bars. Background Art

[0002] In recent years, with the rapid development of the manufacturing industry, the market demand for metal processing equipment with high efficiency, low energy consumption, low cost, and high precision has been increasing day by day. The shearing fixtures used to measure the shearing strength and anti-shearing performance of metal material samples are becoming more and more diverse in form and more refined in structure.

[0003] With the progress of processing technology and the improvement of precision requirements, the applicability and flexibility of shearing fixtures have also been greatly improved. For example, in the patent with the application number CN202221763283.1, a multifunctional shearing fixture is introduced in detail. This fixture is simple to operate and has good use effects. However, the mounting seat of this fixture has a large area, occupies a relatively large space, has relatively strict requirements for the processing environment, and this fixture requires the cooperation of staff to achieve the clamping effect on the workpiece in multiple aspects.

[0004] Another example is the patent with the application number CN201520318303.8, which details a double-shearing test fixture with simple processing technology, convenient operation, and low cost. However, this fixture has specific requirements for the shape of the material to be sheared, has a relatively small application range, and when shearing a material sample smaller than the shearing hole, the sample is likely to roll, thus causing certain errors in the determination of the anti-shearing performance of the sample, and the test results have relatively large fluctuations and certain limitations. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is that in the prior art, the mounting seat of the fixture occupies a relatively large space and the error in the determination of the anti-shearing performance of the sample is relatively large, and the applicability, flexibility, and accuracy are not ideal. To overcome the above defects of the prior art, the utility model provides a shearing test fixture for metal bars, including a shearing test fixture for metal bars and a method for testing the anti-shearing performance of metal bars.

[0006] The utility model provides a shearing test fixture for metal bars, and the test fixture includes a pressure head and a base;

[0007] The pressure head includes an upper fixing column and a shearing component connected to the lower end of the upper fixing column. The upper fixing column is detachably matched with the movable crossbeam of an external mechanical testing machine. The shearing component includes a shearing rod extending vertically and a shearing ring for the metal bar sample to enter and exit. The shearing rod is provided with a first mounting hole penetrating transversely for the shearing ring to be installed, so as to realize the clearance fit between the shearing ring and the shearing rod;

[0008] The base includes a left support sleeve, a right support sleeve, at least four threaded rods, a lower fixing column, and a groove seat connected to the upper end of the lower fixing column;

[0009] Both the left support sleeve and the right support sleeve are provided with insertion holes that penetrate horizontally for the entry and exit of the metal bar sample; both the left support sleeve and the right support sleeve are provided with first upper threaded holes that penetrate vertically from their upper surfaces to communicate with the insertion holes and are adapted to the threaded rods; both the left support sleeve and the right support sleeve are provided with first lower threaded holes that penetrate vertically from their lower surfaces to communicate with the insertion holes and are adapted to the threaded rods;

[0010] The lower fixing column is detachably fitted with the fixed crossbeam of the external mechanical testing machine;

[0011] The groove seat includes a bottom plate and two support parts that are distributed left and right on the bottom plate and are mirror-image corresponding to each other. The bottom plate and the two support parts enclose a groove with an upward opening for the up and down entry and exit of the shear rod;

[0012] Both of the two support parts are provided with second mounting holes that penetrate horizontally. The second mounting hole on the support part on the left side is for the left support sleeve to be inserted, realizing the clearance fit between the support part and the left support sleeve; the second mounting hole on the support part on the right side is for the right support sleeve to be inserted, realizing the clearance fit between the support part and the right support sleeve;

[0013] Both of the two support parts are provided with second upper threaded holes that penetrate vertically from their upper surfaces to communicate with the second mounting holes and are adapted to the threaded rods and correspond to the first upper threaded holes; both of the two support parts are provided with second lower threaded holes that penetrate vertically from their lower surfaces to communicate with the second mounting holes and are adapted to the threaded rods and correspond to the first lower threaded holes.

[0014] A metal bar shearing test fixture of the present utility model is based on the above-mentioned prior art problems. The used indenter includes a fixing column and a shearing component connected to the lower end of the fixing column. The shearing component includes a shear rod extending vertically and a shear ring. The shear ring can be inserted onto the shear rod. The groove presented by the groove seat in the base is for the up and down entry and exit of the shear rod, thereby forming a structure capable of freely connecting the indenter and the base vertically, thus solving the problem that the fixture mounting seat in the prior art occupies a large space, while reducing consumables and lowering the manufacturing cost.

[0015] Meanwhile, the utility model uses at least four threaded rods to replace the two double - helix screws in the prior art. Both the left support sleeve and the right support sleeve are provided with insertion holes for the metal bar sample to enter and exit. The left support sleeve and the right support sleeve are also provided with a first upper threaded hole and a first lower threaded hole that communicate with the insertion holes and are adapted to the threaded rods. Each of the two support parts on the groove seat is provided with a second mounting hole for respectively mounting the left support sleeve and the right support sleeve. Both support parts are provided with a second upper threaded hole that communicates with the second mounting hole, is adapted to the threaded rod, and corresponds to the first upper threaded hole; and both are also provided with a second lower threaded hole that communicates with the second mounting hole, is adapted to the threaded rod, and corresponds to the first lower threaded hole. Furthermore, after the left support sleeve and the right support sleeve are installed in the groove seat, each threaded rod can pass through the threaded holes and be inserted into the insertion holes, so that the metal bar sample is tightly fixed in the left and right support sleeves after being inserted, reducing the error in the measurement of the anti - shear performance of the sample and enhancing the accuracy of the test results. And the four threaded rods can be flexibly adjusted, so that the shear fixture can realize the forward and reverse loading of the test sample, facilitating the study of the kinematic hardening of the material, and greatly improving the applicability, flexibility, and accuracy of the fixture.

[0016] Finally, if the metal bar sample is directly sheared by the groove seat and the shear rod, the force it receives will be transmitted to the entire fixture, which is not conducive to long - term use. Therefore, the utility model uses the left support sleeve and the right support sleeve in combination with the shear ring for the metal bar sample to be inserted, which can play a buffering role during shearing. In addition, if a larger sample (with a difference of 1 - 2 mm from the shear limit size) is used, when the metal bar sample is directly sheared by the groove seat and the shear rod, it is very likely that the sample will get stuck in the groove seat after the experiment, and then the entire fixture needs to be repaired or replaced. Thus, by using the combination of the left support sleeve, the right support sleeve, and the shear ring, the utility model greatly improves the shear efficiency and operation cost, and has good use value.

[0017] In a possible implementation manner, the difference between the diameter of the first mounting hole and the outer diameter of the shear ring is (0.1 - 0.3) mm;

[0018] Compared with the prior art, adopting the above - mentioned technical solution can facilitate the installation or replacement of the shear ring. After the shear ring is installed in the shear rod, it is more conducive to realizing the clearance fit between the shear ring and the shear rod.

[0019] In a possible implementation manner, one end of the left support sleeve is provided with a first clamping edge, and one end of the right support sleeve is provided with a second clamping edge;

[0020] Furthermore, when the left support sleeve and the right support sleeve are installed on the groove seat, they will not extend too far into the groove seat, ensuring that the second upper threaded hole and the first upper threaded hole, and the second lower threaded hole and the first lower threaded hole can be accurately aligned in position, facilitating the insertion of the threaded rods into the respective threaded holes.

[0021] In a possible implementation manner, the insertion holes provided on the left support sleeve have the same diameter as the insertion holes provided on the right support sleeve;

[0022] Furthermore, it helps the same metal bar sample to be inserted into the left support sleeve and the right support sleeve simultaneously, so as to play a buffering role during shearing.

[0023] In a possible implementation manner, the second mounting holes provided on the support part on the left side are coaxially arranged with the second mounting holes provided on the support part on the right side;

[0024] Furthermore, it can ensure that the positions of the left support sleeve and the right support sleeve inserted into the groove seat are aligned, and the same metal bar sample is not distorted when inserted into the left support sleeve and the right support sleeve simultaneously, ensuring the reliability of the shearing test results.

[0025] In a possible implementation manner, the difference between the diameter of the second mounting hole provided on the support part on the left side and the outer diameter of the left support sleeve is (0.1 - 0.3) mm, and the difference between the diameter of the second mounting hole provided on the support part on the right side and the outer diameter of the right support sleeve is (0.1 - 0.3) mm;

[0026] Furthermore, it is convenient for the left support sleeve to be inserted into the second mounting hole on the support part on the left side, ensuring the clearance fit between the support part and the left support sleeve; it is convenient for the right support sleeve to be inserted into the second mounting hole on the support part on the right side, ensuring the clearance fit between the support part and the right support sleeve.

[0027] In a possible implementation manner, all the threaded rods are provided with a rotating rod at one end;

[0028] Furthermore, it is convenient for manual rotation when the threaded rod is screwed out of or into the threaded hole, ensuring that the position of the threaded rod is adjustable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of a metal bar shearing test fixture according to an embodiment of the present application installed on a mechanical testing machine;

[0030] Figure 2 It is a main sectional view of the structure of a metal bar shearing test fixture according to an embodiment of the present application after being assembled;

[0031] Figure 3 It is a side sectional view of the structure of a metal bar shearing test fixture according to an embodiment of the present application after being assembled;

[0032] Figure 4Schematic structural diagram of a metal bar shearing test fixture according to an embodiment of the present application;

[0033] Figure 5 Schematic sectional structure diagram of a metal bar shearing test fixture according to an embodiment of the present application;

[0034] Figure 6 Three - view drawings formed after the assembly of the indenter according to an embodiment of the present application;

[0035] Figure 7 Three - view drawings formed after the assembly of the base according to an embodiment of the present application;

[0036] Figure 8 Flow chart of the method listed in an embodiment of the present application.

[0037] Explanation of reference numerals:

[0038] 1. Indenter, 11. Upper fixing column, 12. Shearing assembly, 121. Shearing rod, 122. Shearing ring, 1221. Inner ring, 123. First mounting hole, 2. Base, 21. Left support sleeve, 211. First clamping edge, 22. Right support sleeve, 221. Second clamping edge, 23. Threaded rod, 231. Rotating rod, 24. Lower fixing column, 25. Groove seat, 251. Bottom plate, 252. Support part, 253. Groove, 254. Second mounting hole, 255. Second upper threaded hole, 256. Second lower threaded hole, 26. Insertion hole, 27. First upper threaded hole, 28. First lower threaded hole, 3. Mechanical testing machine, 31. Moving crossbeam, 32. Fixed crossbeam. Detailed implementation manners

[0039] First of all, those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0040] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0041] In the embodiments of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0042] In addition, it should also be noted that in the embodiments of the present application, unless otherwise clearly specified and limited, the term "vertical" refers to the vertical direction, which is shown as the vertical direction in the drawings of the embodiments of the present application, or more precisely, from top to bottom or from bottom to top in the drawings, that is, the up and down direction. The term "horizontal" refers to the horizontal direction, which is shown as the horizontal direction in the drawings of the embodiments of the present application, or more precisely, from left to right or from right to left in the drawings, that is, the left and right direction. "Clearance fit" means that there is a mounting hole for mounting object B on object A, and object B can be mounted on the mounting hole and there is a clearance between object B and object A.

[0043] The present application will be further described in detail below with reference to the drawings and specific embodiments.

[0044] See Figures 1 to 7 As shown, the embodiments of the present application disclose a shearing test fixture for metal bars. See Figure 1 、 Figure 4 and Figure 5 . The shearing test fixture includes a pressure head 1 and a base 2; see Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 . The pressure head 1 includes an upper fixing column 11 and a shearing assembly 12 connected to the lower end of the upper fixing column 11. The upper fixing column 11 is detachably fitted with the movable crossbeam 31 of an external mechanical testing machine 3, and the corresponding fitting connection relationship is as shown in Figure 1 . The shearing assembly 12 includes a shearing rod 121 extending vertically and a shearing ring 122 for the metal bar sample to enter and exit. The upper end of the shearing rod 121 is connected to the lower end of the fixing column 11. A first mounting hole 123 penetrating horizontally is provided on the shearing rod 121 for the shearing ring 122 to be inserted. It is required that the diameter of the first mounting hole 123 is adapted to the outer diameter of the shearing ring 122 to achieve the clearance fit between the shearing ring 122 and the shearing rod 121.

[0045] See Figure 4 and Figure 5As shown, in order to meet the clearance fit requirements between the shear ring 122 and the shear rod 121, in this embodiment, the difference between the diameter of the first mounting hole 123 and the outer diameter of the shear ring 122 is 0.1 - 0.3 mm. As a specific example, the difference between the diameter of the first mounting hole 123 and the outer diameter of the shear ring 122 is 0.1 mm, or 0.2 mm, or 0.3 mm.

[0046] See Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the base 2 in this embodiment includes a left support sleeve 21, a right support sleeve 22, at least four threaded rods 23, a lower fixing column 24, and a groove seat 25 connected to the upper end of the upper and lower fixing column 24. Among them, all the threaded rods 23 are provided with a rotating rod 231 at one end for hand-held twisting of the corresponding threaded rod 23. Both the left support sleeve 21 and the right support sleeve 22 are provided with insertion holes 26 that penetrate transversely for the entry and exit of metal bar samples; both are provided with first upper threaded holes 27 that penetrate vertically from their respective upper surfaces to communicate with the insertion holes 26 and are adapted to the threaded rods 23; both also are provided with first lower threaded holes 28 that penetrate vertically from their respective lower surfaces to communicate with the insertion holes 26 and are adapted to the threaded rods 23. One end of the left support sleeve 21 is provided with a first clamping edge 211, and one end of the right support sleeve 22 is provided with a second clamping edge 221. The insertion holes 26 provided on the left support sleeve 21 have the same diameter as the insertion holes 26 provided on the right support sleeve 22.

[0047] See Figure 1 As shown, the lower fixing column 24 is detachably fitted with the fixed crossbeam 32 of the external mechanical testing machine 3. See Figure 4 and Figure 5 As shown, the groove seat 25 includes a bottom plate 251 and two support portions 252 that are distributed left and right on the bottom plate 251 and are mirror-image reflections of each other. The bottom plate 251 is connected to the upper end of the lower fixing column 24, and the bottom plate 251 and the two support portions 252 enclose a groove 253 that opens upward for the up and down entry and exit of the shear rod 121.

[0048] Please continue to see Figure 4 and Figure 5As shown, both of the two support parts 252 are provided with second mounting holes 254 penetrating transversely. The second mounting holes 254 provided on the left support part 252 and the second mounting holes 254 provided on the right support part 252 are coaxially arranged. The second mounting hole 254 on the left support part 252 is for the left support sleeve 21 to be inserted, realizing the clearance fit between this support part 252 and the left support sleeve 21. Specifically, in order to realize the clearance fit between this support part 252 and the left support sleeve 21, in this embodiment, the difference between the diameter of the second mounting hole 254 provided on the left support part 252 and the outer diameter of the left support sleeve 21 is 0.1 - 0.3 mm, and the specific difference can be preferably 0.1 mm, 0.2 mm or 0.3 mm.

[0049] Please continue to refer to Figure 4 and Figure 5 As shown, the second mounting hole 254 on the right support part 252 is for the right support sleeve 22 to be inserted, realizing the clearance fit between this support part 252 and the right support sleeve 22. In order to realize the clearance fit between this support part 252 and the right support sleeve 22, in this embodiment, the difference between the diameter of the second mounting hole 254 provided on the right support part 252 and the outer diameter of the right support sleeve 22 is 0.1 - 0.3 mm, and the specific difference can be preferably 0.1 mm, 0.2 mm or 0.3 mm.

[0050] Refer to Figure 2 、 Figure 3 、 Figure 4 and Figure 5 As shown, in this embodiment, both of the two support parts 252 are provided with second upper threaded holes 255 that penetrate vertically from their upper surfaces to communicate with the second mounting holes 254 and are adapted to the threaded rod 23 and correspond to the first upper threaded holes 27. The so-called corresponding to the first upper threaded hole 27 means that when the left support sleeve 21 (or the right support sleeve 22) is inserted onto the left support part 252 (or the right support part 252), by moving or rotating the left support sleeve 21 (or the right support sleeve 22), the first upper threaded hole 27 provided on the left support sleeve 21 (or on the right support part 252) can be coaxially aligned with the second upper threaded hole 255, so that the threaded rod 23 can pass through the first upper threaded hole 27 and the second upper threaded hole 255 and enter the insertion hole 26 of the left support sleeve 21 (or the right support sleeve 22).

[0051] Meanwhile, in this embodiment, both of the two supporting parts 252 are provided with second lower threaded holes 256 which penetrate vertically from their lower surfaces to communicate with the second mounting holes 254 and are adapted to the threaded rod 23 and correspond to the first lower threaded holes 28. The so-called corresponding to the first lower threaded hole 28 means that when the left support sleeve 21 (or the right support sleeve 22) is installed on the left supporting part 252 (or the right supporting part 252), the left support sleeve 21 (or the right support sleeve 22) can be moved or rotated so that the first lower threaded hole 28 provided on the left support sleeve 21 (or the right supporting part 252) is coaxial with the second lower threaded hole 256, and then the threaded rod 23 can pass through the first lower threaded hole 28 and the second lower threaded hole 256 and enter the insertion hole 26 of the left support sleeve 21 (or the right support sleeve 22).

[0052] In addition, the insertion hole 26 of the left support sleeve 21 (or the right support sleeve 22) can be made to have the same size as the inner ring 1221 of the shear ring 122 as much as possible, preferably the same type of through hole, to ensure that the metal rod sample will not bend after being inserted into the two insertion holes 26 and the shear ring 122, and ensure the reliability of the shear result.

[0053] A metal bar shear test fixture disclosed in an embodiment of the present application can be applied to the shear resistance test of metal bars. See Figure 8 as shown, and the corresponding specific method includes the following steps:

[0054] S1: Assemble the indenter 1 and the base 2, and respectively perform the operations of installing the indenter 1 on the movable crossbeam 31 of the mechanical testing machine 3 and fixing the base 2 on the fixed crossbeam 32 of the mechanical testing machine 3;

[0055] Specifically, in this embodiment, step S1 includes the following steps:

[0056] S11: Install the shear ring 122 into the shear rod 121 to complete the assembly of the indenter 1, and connect the upper fixing column 11 to the movable crossbeam 31 of the mechanical testing machine 3 to complete the installation of the indenter 1;

[0057] After the shear ring 122 is installed into the shear rod 121, the assembly of the indenter 1 is completed. The pattern formed after assembly is as shown in Figure 2 or Figure 3 as shown, and the corresponding three-view drawings are as shown in Figure 6 as shown;

[0058] S12: Respectively perform the operations of installing the left support sleeve 21 into the left supporting part 252 and installing the right support sleeve 22 into the right supporting part 252;

[0059] S13: Screw the two threaded rods 23 into the respective second upper threaded holes 255 of the two supporting parts 252, and pass through the second upper threaded holes 255 and the first upper threaded holes 27. Screw the remaining two threaded rods 23 into the respective second lower threaded holes 256 of the two supporting parts 252, and pass through the second lower threaded holes 256 and the first lower threaded holes 28, thereby completing the assembly of the base 2. The corresponding assembly result is as shown in Figure 2 , Figure 3 shown. The three - view drawings of the corresponding assembly of the base 2 are as shown in Figure 7 shown;

[0060] S14: Connect the lower fixing column 24 to the fixed crossbeam 32 of the mechanical testing machine 3, thereby completing the installation of the base 2. The corresponding installation result is as shown in Figure 1 shown.

[0061] S2: Insert the metal bar sample into the left support sleeve 21 along the insertion hole 26 of the left support sleeve 21; or insert the metal bar sample into the right support sleeve 22 along the insertion hole 26 of the right support sleeve 22.

[0062] S3: Control the movable crossbeam 31 of the mechanical testing machine 3 to move downward so that the shear rod 121 is inserted into the groove 253 of the groove seat 25, and stop moving downward when the shear ring 122 moves to the middle of the left support sleeve 21 and the right support sleeve 22.

[0063] S4: Adjust the insertion depth of the metal bar sample to simultaneously enter the left support sleeve 21, the shear ring 122, and the right support sleeve 22.

[0064] S5: Adjust the respective positions of the four threaded rods 23 according to the shear requirements of the metal bar sample, and control the movable crossbeam 31 of the mechanical testing machine 3 to move downward or upward to complete the shearing;

[0065] Please continue to refer to Figure 8 shown. In this embodiment, step S5 includes the following steps:

[0066] S51: Determine whether the shear requirement of the metal bar sample is compression shear or tension shear. If it is compression shear, execute step S52; if it is tension shear, execute step S53;

[0067] S52: Rotate the two lower threaded rods 23 located below downward to make them return to the lower threaded holes 28, and rotate the two upper threaded rods 23 downward to fix the metal bar sample. Control the movable crossbeam 31 of the mechanical testing machine 3 to move downward until the metal bar sample is cut off;

[0068] S53: Rotate the upper two threaded rods 23 upward respectively to make them return to the second lower threaded holes 28, and rotate the lower two threaded rods 23 upward to fix the metal bar sample. Then, control the movable crossbeam 31 of the mechanical testing machine 3 to move upward until the metal bar sample is broken.

[0069] A metal bar shearing test fixture disclosed in an embodiment of the present application can achieve a large strain range when used for shearing experiments of materials. During the test process, the strain rate can be effectively controlled. During the deformation process, plastic instability phenomena such as buckling and necking hardly occur. Since forward and reverse loading can be carried out, shear performance tests can be performed according to the specific application scenarios of the research materials. At the same time, for the metal bar shearing test fixture of the embodiment of the present application, both the pressure head 1 and the base 2 can be firmly fixed on the mechanical testing machine 3, which fully improves the utilization rate of the fixtures of the existing equipment. In addition, the support sleeve of the fixture is connected by threaded rods, which ensures that the fixture will not move laterally during the test and will not affect the test results.

[0070] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inner" and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present application.

[0071] In the description of the present application, the description with reference to terms such as "one embodiment", "some embodiments", "in this embodiment", "specific examples", or "some examples" means that the specific features, mechanisms, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0072] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A metal bar shear test fixture, characterized in that: It comprises a pressure head (1) and a base (2); The pressure head (1) comprises an upper fixed column (11) and a shearing assembly (12) connected to the lower end of the upper fixed column (11); the upper fixed column (11) is detachably matched with a movable crossbeam (31) of an external mechanical testing machine (3); the shearing assembly (12) comprises a shearing rod (121) extending vertically and a shearing ring (122) for the entry and exit of a metal bar sample; the shearing rod (121) is provided with a first mounting hole (123) extending in the transverse direction for the shearing ring (122) to be installed therein, so as to achieve clearance fit between the shearing ring (122) and the shearing rod (121); The base (2) comprises a left supporting sleeve (21), a right supporting sleeve (22), at least four threaded rods (23), a lower fixing column (24) and a groove seat (25) connected to the upper end of the lower fixing column (24); The left support sleeve (21) and the right support sleeve (22) are both provided with an insertion hole (26) which penetrates in the transverse direction for the metal bar sample to enter and exit; the left support sleeve (21) and the right support sleeve (22) are both provided with a first upper threaded hole (27) which penetrates vertically from the upper surface thereof to communicate with the insertion hole (26) and is adapted to the threaded rod (23); the left support sleeve (21) and the right support sleeve (22) are both provided with a first lower threaded hole (28) which penetrates vertically from the lower surface thereof to communicate with the insertion hole (26) and is adapted to the threaded rod (23); The lower fixed column (24) is detachably matched with the fixed crossbeam (32) of the external mechanical testing machine (3); The groove seat (25) comprises a bottom plate (251) and two supporting parts (252) which are arranged on the bottom plate (251) in a distributed manner on the left and right sides and are mirror-reflective of each other. The bottom plate (251) and the two supporting parts (252) form a groove (253) which opens upwards for the shear rod (121) to enter and exit upwards. The two support parts (252) are each provided with a second mounting hole (254) extending in the transverse direction. The second mounting hole (254) on the support part (252) on the left side is for the left support sleeve (21) to be installed therein, so as to achieve a clearance fit between the support part (252) and the left support sleeve (21); the second mounting hole (254) on the support part (252) on the right side is for the right support sleeve (22) to be installed therein, so as to achieve a clearance fit between the support part (252) and the right support sleeve (22); The two support portions (252) are each provided with a second upper threaded hole (255) which passes vertically from the upper surface thereof to communicate with the second mounting hole (254), is adapted to the threaded rod (23), and corresponds to the first upper threaded hole (27); the two support portions (252) are each provided with a second lower threaded hole (256) which passes vertically from the lower surface thereof to communicate with the second mounting hole (254), is adapted to the threaded rod (23), and corresponds to the first lower threaded hole (28).

2. The metal bar shear test fixture according to claim 1, characterized in that: The difference between the diameter of the first mounting hole (123) and the outer diameter of the shear ring (122) is (0.1-0.3) mm.

3. The metal bar shear test fixture according to claim 2, characterized in that: One end of the left supporting sleeve (21) is provided with a first clamping edge (211), and one end of the right supporting sleeve (22) is provided with a second clamping edge (221).

4. The metal bar shear test fixture according to any one of claims 1 to 3, characterized in that: The insertion hole (26) provided on the left supporting sleeve (21) and the insertion hole (26) provided on the right supporting sleeve (22) have the same diameter.

5. The metal bar shear test fixture according to claim 4, characterized in that: The second mounting hole (254) provided on the support portion (252) located on the left side is coaxially arranged with the second mounting hole (254) provided on the support portion (252) located on the right side.

6. The metal bar shear test fixture according to claim 5, characterized in that: The difference between the diameter of the second mounting hole (254) provided on the support portion (252) on the left side and the outer diameter of the left support sleeve (21) is (0.1-0.3) mm, and the difference between the diameter of the second mounting hole (254) provided on the support portion (252) on the right side and the outer diameter of the right support sleeve (22) is (0.1-0.3) mm.

7. The metal bar shear test fixture according to claim 1 or 2 or 3 or 5 or 6, characterized in that: All of the threaded rods (23) are provided with a rotating rod (231) at one end.

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