Pull-off test clamp and pull-off test machine
By designing a pull-out test fixture suitable for sheet metal structures with significantly different strength properties, and utilizing a combination of upper and lower pull-out components, premature deformation of low-strength sheets is prevented, thus enabling reliability assessment and life prediction of riveted specimens made of dissimilar materials.
Patent Information
- Application Number
- CN202422916060.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-27
AI Technical Summary
Existing pull-out test fixtures are not suitable for two plate structures with significantly different strength properties, making it difficult to assess the structural strength reliability and predict the lifespan of riveted specimens made of heterogeneous materials.
A pull-out test fixture was designed, including an upper pull-out component, a fixing component, and a lower pull-out component. The low-strength plate is fixed by a threaded structure or snap-fit terminals, and the high-strength plate is hooked by claws to ensure that the low-strength plate does not deform and slip out prematurely during the test. The symmetrical structure and reinforced connecting plates are used to improve the uniformity of the load.
It effectively prevents low-strength plates from deforming and slipping prematurely during pull-out tests, ensuring the smooth progress of the tests and improving the accuracy of evaluating the connection performance of riveted specimens made of dissimilar materials.
Smart Images
Figure CN223500773U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of strength testing equipment technology, and more specifically, to a pull-out test fixture. Furthermore, this utility model also relates to a pull-out testing machine including the aforementioned pull-out test fixture. Background Technology
[0002] In the field of rail transit vehicle manufacturing and assembly, lightweighting of trains is one of the key technologies for achieving high-speed trains. Aluminum alloys have the material characteristics of low density and high plasticity, while steel has the material characteristics of high strength, high hardness, and high wear resistance. These two types of sheet metal are widely used in vehicle body manufacturing. As for sheet metal joining technology, riveting has been increasingly used due to its advantages such as no heat input, high degree of automation, and simple process. In particular, riveted specimens of dissimilar materials are widely used in various structures of transportation vehicles. Due to the large performance difference between steel and aluminum, and the fact that the clamping force of the ring groove rivet may decrease under the influence of impact, material creep, or deformation of the connection structure, dissimilar material riveted specimens have disadvantages such as difficulty in assessing structural strength reliability and difficulty in predicting lifespan. Therefore, tensile strength tests are often required to perform performance testing.
[0003] For similar pull-out test requirements, pull-out test fixtures exist in related technologies to perform pull-out tests on steel / steel riveted structures. By comparing load-displacement curves using a pull-out test machine, the optimal riveting parameters can be determined. However, existing pull-out test fixtures are not suitable for two types of plates with significantly different structural strength properties.
[0004] In summary, how to provide a pull-out test fixture suitable for two types of plate structures with significantly different strength properties is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0005] In view of this, the purpose of this utility model is to provide a pull-out test fixture that can effectively prevent low-strength plates from deforming and slipping prematurely during pull-out tests, and is suitable for pull-out tests on two plate structures with significantly different strength properties.
[0006] Another objective of this invention is to provide a pull-out testing machine that includes the aforementioned pull-out testing fixture.
[0007] To achieve the above objectives, this utility model provides the following technical solution:
[0008] A pull-off test fixture, comprising:
[0009] The upper pull-out component, the top of which is used to connect to the upper clamp of the pull-out testing machine;
[0010] A fixing member, which is movably connected to the bottom end of the upper pulling and detaching member, is used to clamp or loosen the low-strength plate in the heterogeneous material combination riveting specimen.
[0011] A lower pulling and detaching member, whose bottom end is used to be connected to the lower clamp of the pulling and detaching testing machine, and whose top end has two oppositely arranged hooks for hanging or detaching from the high-strength plate in the heterogeneous material combination riveting specimen.
[0012] In some possible embodiments, the fixing member is in a long strip-shaped flat plate structure, and both ends of the fixing member are used for detachable connection to the upper pulling and detaching member. A reserved through hole is provided at the middle position of the fixing member for inserting the rivet head in the heterogeneous material combination riveting specimen.
[0013] In some possible embodiments, the bottom end of the upper pulling and detaching member is a first pulling and detaching structure in a square shape with a first opening at the middle position of the bottom plate. Both the first end and the second end of the first pulling and detaching structure along its own length direction have first connection through holes.
[0014] Both ends of the fixing member have second connection through holes, and the fixing member can be inserted into the inner cavity of the first pulling and detaching structure, and the second connection through holes and the corresponding first connection through holes are coaxially extended to insert a threaded rod.
[0015] In some possible embodiments, the top end of the lower pulling and detaching member is a second pulling and detaching structure in a square shape with a second opening at the middle position of the top plate.
[0016] In some possible embodiments, the top end of the upper pulling and detaching member has a first connecting plate extending vertically for connecting to the upper clamp, and the bottom end of the lower pulling and detaching member has a second connecting plate extending vertically for connecting to the lower clamp;
[0017] The first connecting plate extends along the length direction of the first pulling and detaching structure, and the second connecting plate extends along the width direction of the second pulling and detaching structure;
[0018] Or, the first connecting plate extends along the width direction of the first pulling and detaching structure, and the second connecting plate extends along the length direction of the second pulling and detaching structure.
[0019] In some possible embodiments, the first connecting plate is located at the middle position of the top plate of the first pulling and detaching structure;
[0020] The second connecting plate is connected to the middle position of the bottom plate of the second pulling and detaching structure.
[0021] In some possible embodiments, the upper pulling and detaching member, the fixing member and the lower pulling and detaching member are all symmetric structures.
[0022] In some possible embodiments, the first connecting plate is connected to the first pull-out structure via a first reinforcing connecting plate, and the upper pull-out member has a three-layer stepped structure;
[0023] The second connecting plate is connected to the second pull-out structure via a second reinforcing connecting plate, and the pull-out member has a three-layer stepped structure.
[0024] In some possible embodiments, the upper pull-out member is equipped with a drive assembly, and the fixing member is connected to the output end of the drive assembly to drive the fixing member to move vertically up and down.
[0025] A pull-out testing machine, comprising the pull-out testing fixture described in any one of the above claims.
[0026] The pull-out test fixture provided by this utility model has an upper pull-out component with a rod or plate-like structure at its upper end, which can be used to fix the upper pull-out component on the upper clamp of the pull-out test machine. Similarly, the lower pull-out component has a rod or plate-like structure at its lower end, which can be used to fix the lower pull-out component on the lower clamp of the pull-out test machine.
[0027] Furthermore, the fastener can be fixed to the lower end of the upper pull-out component via a threaded structure or snap-fit terminals. After the fastener is installed in place, it can work with the upper pull-out component to clamp the low-strength plate in the heterogeneous material riveting specimen. Conversely, by removing the fastener from the upper pull-out component or pushing the fastener in the opposite direction, the low-strength plate in the heterogeneous material riveting specimen can be loosened and removed. The upper end of the lower pull-out component has an arched or L-shaped hook to hook the high-strength plate in the heterogeneous material riveting specimen.
[0028] In use, first fix the low-strength sheet. Specifically, place the easily deformable low-strength sheet between the upper pull-out member and the fixing member, and then adjust the upper pull-out member and / or the fixing member to clamp the low-strength sheet. Next, install the upper pull-out member on the upper clamp of the pull-out testing machine, that is, clamp the upper end of the upper pull-out member with the upper clamp so that a load can be applied to the heterogeneous material composite riveted specimen to be tested through the upper pull-out member. Adjust the lower pull-out member to hook the low-strength sheet of the heterogeneous material composite riveted specimen. Specifically, rotate the lower pull-out member so that it is aligned with the upper pull-out member. The pull-out component is then pushed down at a right angle so that the hook at the upper end of the pull-out component catches the low-strength plate of the heterogeneous material composite riveted specimen. The pull-out component is then installed on the lower clamp of the pull-out testing machine, that is, the lower end of the pull-out component is clamped by the lower clamp. Finally, the pull-out test can be carried out. The pull-out testing machine applies tensile force to the heterogeneous material composite riveted specimen to be tested step by step through the upper and lower pull-out components. The connection performance of the heterogeneous material composite riveted specimen is predicted based on the specimen morphology, rivet condition and load-displacement curve after pull-out.
[0029] In summary, using this pull-out test fixture can pre-fix the low-strength plate in a heterogeneous material composite riveted specimen, effectively preventing the low-strength plate from deforming and slipping prematurely during the pull-out test, thus ensuring the smooth conduct of the pull-out test. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0031] Figure 1 This is a schematic diagram illustrating the use of a specific embodiment of this utility model;
[0032] Figure 2 This is a schematic diagram of the structure of the upper pull-out component in a specific embodiment of this utility model;
[0033] Figure 3 This is a structural schematic diagram of the fastener provided in a specific embodiment of the present utility model;
[0034] Figure 4 This is a schematic diagram of the pull-down release component provided in a specific embodiment of the present utility model.
[0035] Figure label:
[0036] 1-Upper pull-out component; 11-First pull-out structure; 111-First connecting through hole; 12-First connecting plate; 13-First reinforcing connecting plate; 2-Fixing component; 21-Reserved through hole; 22-Second connecting through hole; 3-Lower pull-out component; 31-Second pull-out structure; 32-Second connecting plate; 33-Second reinforcing connecting plate. Detailed Implementation
[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0038] The core of this invention is to provide a pull-out test fixture that effectively prevents low-strength plates from deforming and slipping prematurely during pull-out testing. This fixture is suitable for pull-out testing of two plate structures with significantly different strength properties. Another core aspect of this invention is to provide a pull-out testing machine that includes the aforementioned pull-out test fixture.
[0039] Please refer to Figure 1 This utility model provides a pull-out test fixture, including an upper pull-out component 1, a fixing component 2, and a lower pull-out component 3. The top end of the upper pull-out component 1 is connected to the upper clamp of the pull-out testing machine; the fixing component 2 is movably connected to the bottom end of the upper pull-out component 1 to clamp or release the low-strength plate in the heterogeneous material riveting specimen; the bottom end of the lower pull-out component 3 is connected to the lower clamp of the pull-out testing machine, and its top end has two opposing claws for attaching or detaching from the high-strength plate in the heterogeneous material riveting specimen.
[0040] like Figure 1 As shown, the upper pull-out member 1 has a structure of rod or plate at its upper end, which can be used to fix the upper pull-out member 1 to the upper clamp of the pull-out testing machine. Similarly, the lower pull-out member 3 has a structure of rod or plate at its lower end, which can be used to fix the lower pull-out member 3 to the lower clamp of the pull-out testing machine.
[0041] Furthermore, the fastener 2 can be fixed to the lower end of the upper pull-out member 1 through a threaded structure or snap-fit terminal, etc. After the fastener 2 is installed in place, it can cooperate with the upper pull-out member 1 to clamp the low-strength plate in the heterogeneous material combination riveting specimen. Conversely, by removing the fastener 2 from the upper pull-out member 1 or pushing the fastener 2 in the opposite direction, the low-strength plate in the heterogeneous material combination riveting specimen can be loosened and removed. The upper end of the lower pull-out member 3 has an arched or L-shaped hook, etc., which can hook the high-strength plate in the heterogeneous material combination riveting specimen.
[0042] In use, first, fix the low-strength plate. Specifically, place the easily deformable low-strength plate between the upper pull-out member 1 and the fixing member 2, and then adjust the upper pull-out member 1 and / or the fixing member 2 to clamp the low-strength plate. Next, install the upper pull-out member 1 on the upper clamp of the pull-out testing machine, that is, clamp the upper end of the upper pull-out member 1 with the upper clamp so that the load can be applied to the heterogeneous material combination riveted specimen to be tested through the upper pull-out member 1. Adjust the lower pull-out member 3 to hook the low-strength plate of the heterogeneous material combination riveted specimen. Specifically, rotate the lower pull-out member 3 so that it is perpendicular to the upper pull-out member 1, and then push the lower pull-out member 3 horizontally so that the hook at the upper end of the lower pull-out member 3 hooks the low-strength plate of the heterogeneous material combination riveted specimen. Then install the lower pull-out member 3 on the lower clamp of the pull-out testing machine, that is, clamp the lower end of the lower pull-out member 3 with the lower clamp. Finally, the pull-out test can be performed. The test involves applying tensile force to the heterogeneous material composite riveted specimen through the upper pull-out component 1 and the lower pull-out component 3. The connection performance of the heterogeneous material composite riveted specimen is predicted based on the specimen morphology, rivet condition, and load-displacement curve after pull-out. Furthermore, the load-displacement curve can be automatically recorded and plotted by the pull-out testing machine. Test points are selected on this curve to estimate the slope. When the slope estimated using the latter two points is 2 to 3 times greater than the slope estimated using the former two points, the currently selected test point is located near the critical point between the linear elastic stage and the elastoplastic stage. When the slope of the load-displacement curve approaches 0, it indicates that the specimen has reached the pull-out limit. Finally, if the specimen's load-displacement curve meets this condition and exhibits bending fracture of the low-strength, low-rigidity plate without significant deformation or damage to the rivet, the joint performance of the heterogeneous material composite riveted specimen can be considered qualified.
[0043] In summary, using this pull-out test fixture can pre-fix the low-strength plate in a heterogeneous material composite riveted specimen, effectively preventing the low-strength plate from deforming and slipping prematurely during the pull-out test, thus ensuring the smooth conduct of the pull-out test.
[0044] To prevent interference when using fastener 2 to clamp low-strength plates in riveted specimens made of dissimilar materials with large differences, such as... Figure 3 As shown, based on the above embodiment, the fastener 2 is a long strip-shaped flat plate structure. The two ends of the fastener 2 are detachably connected to the upper pull-out member 1. The middle position of the fastener 2 has a reserved through hole 21 for inserting the rivet head in the heterogeneous material combination riveting test piece. The reserved through hole 21 can be a round hole or a square hole, etc.
[0045] Based on the above embodiment, the bottom end of the upper pull-out member 1 is a U-shaped first pull-out structure 11 with a first opening in the middle of the base plate. The first pull-out structure 11 has a first connecting through hole 111 at both its first and second ends along its own length direction. Both ends of the fixing member 2 have a second connecting through hole 22, and the fixing member 2 can be inserted into the inner cavity of the first pull-out structure 11, such that the second connecting through hole 22 and the corresponding first connecting through hole 111 extend with the same diameter to insert a threaded rod. It should be noted that "the second connecting through hole 22 and the corresponding first connecting through hole 111 extend with the same diameter" means that the second connecting through hole 22 is located on the extension path of the channel where the corresponding first connecting through hole 111 is located along its length direction.
[0046] like Figure 1 and Figure 2 As shown, the upper pull-out component 1 is a hollow rectangular column structure, with a first opening in the middle of its base plate. In the upper pull-out component 1, the left end of the top plate and the left side of the bottom plate have a common diameter channel serving as a first connecting through hole 111, and the right end of the top plate and the right side of the bottom plate have a common diameter channel serving as another first connecting through hole 111. Correspondingly, second connecting through holes 22 are provided at both the left and right ends of the fixing component 2. After the fixing component 2 is inserted into place, as... Figure 1 As shown, from top to bottom, the left first connecting through hole 111 located in a portion of the top plate of the first pull-out structure 11, the left second connecting through hole 22, and the left first connecting through hole 111 located in a portion of the left side structure of the bottom plate of the first pull-out structure 11 extend along the common diameter to allow for the insertion of a threaded rod; similarly, from top to bottom, the right first connecting through hole 111 located in a portion of the top plate of the first pull-out structure 11, the right second connecting through hole 22, and the right first connecting through hole 111 located in a portion of the right side structure of the bottom plate of the first pull-out structure 11 extend along the common diameter to allow for the insertion of a threaded rod.
[0047] Based on the above embodiment, the top of the pull-out member 3 is a U-shaped second pull-out structure 31 with a second opening in the middle of the top plate, as shown in the example. Figure 1 and Figure 4 As shown, with this configuration, the pull-down release component 3 has a simple structure and is relatively easy and cost-effective to manufacture.
[0048] Based on the above embodiment, the top end of the upper pull-out member 1 has a first connecting plate 12 extending vertically for connecting to the upper clamp, and the bottom end of the lower pull-out member 3 has a second connecting plate 32 extending vertically for connecting to the lower clamp.
[0049] like Figure 2 As shown, the uppermost end of the upper pull-out component 1 is the first connecting plate 12 extending vertically. Similarly, as... Figure 4As shown, the lowest end of the pull-down release piece 3 is also the second connecting plate 32 that extends vertically.
[0050] In some specific embodiments, the first connecting plate 12 extends along the length direction of the first pull-out structure 11, and the second connecting plate 32 extends along the width direction of the second pull-out structure 31; conversely, in other specific embodiments, the first connecting plate 12 extends along the width direction of the first pull-out structure 11, and the second connecting plate 32 extends along the length direction of the second pull-out structure 31.
[0051] In summary, in the two specific embodiments described above, when the lower pull-out member 3 and the upper pull-out member 1 are at right angles, that is, when the upper pull-out member 1 and the lower pull-out member 3 are in the state of clamping the heterogeneous material combination riveting test piece, the first connecting plate 12 is parallel to the second connecting plate 32, so as to facilitate the fixed connection of the pull-out test fixture by the upper clamp and the lower clamp.
[0052] Based on the above embodiment, the first connecting plate 12 is located in the middle of the top plate of the first pull-out structure 11; the second connecting plate 32 is connected to the middle of the bottom plate of the second pull-out structure 31 to improve the uniformity of the load applied to the heterogeneous material combination riveting specimen.
[0053] Based on the above embodiments, the upper pull-out member 1, the fixing member 2, and the lower pull-out member 3 are all symmetrical structures to further improve the uniformity of the load applied to the heterogeneous material combination riveting specimen and improve the accuracy of the test results.
[0054] Based on the above embodiments, the first connecting plate 12 is connected to the first pull-out structure 11 through the first reinforcing connecting plate 13, and the upper pull-out member 1 has a three-layer stepped structure; the second connecting plate 32 is connected to the second pull-out structure 31 through the second reinforcing connecting plate 33, and the lower pull-out member 3 has a three-layer stepped structure to improve the tensile strength of the upper pull-out member 1 and the lower pull-out member 3.
[0055] For example, such as Figure 2 As shown, the first connecting plate 12 extends along the width direction of the upper pull-out structure, and the width of the first connecting plate 12 is smaller than the width of the first reinforcing connecting plate 13. The width of the first reinforcing connecting plate 13 is smaller than the length of the top plate of the upper pull-out structure. The lengths of the first connecting plate 12, the first reinforcing connecting plate 13, and the width of the top plate of the upper pull-out structure are all equal. Figure 4 As shown, the second connecting plate 32 extends along the length direction of the pull-down structure. The length of the bottom plate of the pull-down structure is greater than the length of the second reinforcing connecting plate 33. The length of the second reinforcing connecting plate 33 is greater than the length of the first connecting plate 12. The width of the bottom plate of the pull-down structure is greater than the width of the second reinforcing connecting plate 33. The width of the second reinforcing connecting plate 33 is greater than the width of the first connecting plate 12.
[0056] Based on the above embodiment, the upper pull-out member 1 is equipped with a drive assembly, and the fixing member 2 is connected to the output end of the drive assembly to drive the fixing member 2 to move vertically up and down.
[0057] refer to Figure 1 As shown, the drive assembly may include an electric telescopic rod, or it may also include a motor, gears, and racks. The fixing member 2 is installed on the output end of the drive assembly. When in use, the drive assembly is started to drive the fixing member 2 to descend, thereby cooperating with the pull-out member 1 to clamp the low-strength plate in the heterogeneous material combination riveting specimen. Conversely, driving the fixing member 2 to rise will release the low-strength plate in the heterogeneous material combination riveting specimen.
[0058] In addition to the pull-out test fixture described above, this utility model also provides a pull-out testing machine that includes the pull-out test fixture disclosed in the above embodiments. For the structure of other parts of the pull-out testing machine, please refer to the prior art, which will not be repeated here.
[0059] It should be noted that the relational terms such as "first" and "second" mentioned above are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities; the terms "upper surface," "lower surface," "top," and "bottom" and the directional terms "upper," "lower," "left," and "right" mentioned above are defined based on the accompanying drawings in the specification.
[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0061] The pull-out test fixture and pull-out test machine provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.
Claims
1. A pull-out test fixture, characterized in that, include: The upper pull-out component (1) has its top end used to connect to the upper clamp of the pull-out testing machine; The fastener (2) is movably connected to the bottom end of the upper pull-out member (1) for clamping or loosening the low-strength plate in the heterogeneous material combination riveting specimen; The pull-out component (3) has its bottom end connected to the lower clamp of the pull-out tester, and its top end has two opposing claws for attaching or detaching from the high-strength plate in the heterogeneous material combination riveting specimen.
2. The pull-out test fixture according to claim 1, characterized in that, The fastener (2) is a long strip-shaped flat plate structure. Both ends of the fastener (2) are detachably connected to the upper pull-out member (1). The middle position of the fastener (2) has a reserved through hole (21) for inserting the rivet head in the heterogeneous material combination riveting test piece.
3. The pull-out test fixture according to claim 2, characterized in that, The bottom end of the upper pull-out member (1) is a first pull-out structure (11) with a first opening in the middle of the bottom plate, and the first pull-out structure (11) has a first connecting through hole (111) at both the first end and the second end along its own length direction. Both ends of the fixing member (2) have second connecting through holes (22), and the fixing member (2) can be inserted into the inner cavity of the first pull-out structure (11), and the second connecting through hole (22) and the corresponding first connecting through hole (111) have the same diameter extension to insert the threaded rod.
4. The pull-out test fixture according to claim 3, characterized in that, The top of the pull-out member (3) is a second pull-out structure (31) with a second opening in the middle of the top plate, which is shaped like a square.
5. The pull-out test fixture according to claim 4, characterized in that, The top end of the upper pull-out member (1) has a first connecting plate (12) extending vertically for connecting to the upper clamp, and the bottom end of the lower pull-out member (3) has a second connecting plate (32) extending vertically for connecting to the lower clamp. The first connecting plate (12) extends along the length direction of the first pull-out structure (11), and the second connecting plate (32) extends along the width direction of the second pull-out structure (31); Alternatively, the first connecting plate (12) extends along the width direction of the first pull-out structure (11), and the second connecting plate (32) extends along the length direction of the second pull-out structure (31).
6. The pull-out test fixture according to claim 5, characterized in that, The first connecting plate (12) is located in the middle of the top plate of the first pull-out structure (11); The second connecting plate (32) is connected to the middle position of the bottom plate of the second pull-out structure (31).
7. The pull-out test fixture according to claim 6, characterized in that, The upper pull-out component (1), the fixing component (2), and the lower pull-out component (3) are all symmetrical structures.
8. The pull-out test fixture according to claim 5, characterized in that, The first connecting plate (12) is connected to the first pull-out structure (11) through the first reinforcing connecting plate (13), and the upper pull-out member (1) has a three-layer stepped structure; The second connecting plate (32) is connected to the second pull-out structure (31) through the second reinforcing connecting plate (33), and the pull-out member (3) has a three-layer stepped structure.
9. The pull-out test fixture according to claim 1, characterized in that, The upper pull-out component (1) is equipped with a drive assembly, and the fixing component (2) is connected to the output end of the drive assembly to drive the fixing component (2) to move vertically up and down.
10. A pull-out testing machine, characterized in that, Includes the pull-out test fixture as described in any one of claims 1-9.