Metal sheet high temperature tensile test fixture

Abstract

The utility model discloses a metal sheet high temperature tensile test fixture, including upper clamping concrete and lower clamping concrete, the one end of upper clamping concrete and lower clamping concrete all is provided with internal thread hole, and upper clamping concrete and lower clamping concrete are respectively connected through internal thread hole and high temperature tensile rod screw thread, the middle part of upper clamping concrete and lower clamping concrete all is provided with clamping concrete through slot and dowel through -hole, and the inside of clamping concrete through slot is equipped with inserting sheet tensile test sample, and the end of sheet tensile test sample is provided with test sample end dowel hole, and test sample end dowel hole and dowel through -hole are aligned along horizontal direction, the middle part of clamping concrete through slot is equipped with the clamping groove dowel hole of front -back through -penetrating dowel through -hole center, be equipped with the bolt that inserts along the thickness direction of sheet tensile test sample in the clamping groove dowel hole, and the middle part of bolt is provided with bolt through -hole, and one end of bolt is provided with bolt through slot, the utility model discloses have simple operation, high reliability, the advantage that dismounts conveniently, the stability of clamping of fixture is improved significantly.

Description

Technical Field

[0001] This utility model relates to the field of tensile testing fixture technology, specifically a high-temperature tensile testing fixture for thin metal sheets. Background Technology

[0002] Thin sheet materials are increasingly widely used in high-end equipment fields such as automobile manufacturing and aerospace, and their high-temperature mechanical property testing has become a key link in material research and development and quality control. In high-temperature tensile testing of thin sheets, pin clamps are a traditional method of specimen clamping, connecting the specimen to the tensile testing machine by inserting pins after drilling holes at both ends of the specimen. However, with the development of thinner materials, the thickness of which is mostly less than 2.0 mm, the limitations of this clamp are becoming increasingly apparent, mainly in two aspects:

[0003] 1) Specimen pin hole deformation and test failure: Traditional pin clamps will generate a severe stress concentration effect around the pin hole during the tensile process. When the tensile load increases, the weak pin hole edge is very prone to "gap" phenomenon, that is, the pin hole is torn or elongated, causing the specimen to break prematurely in the non-test area. More seriously, pin hole deformation will introduce additional friction and local stress, which will distort the measured stress-strain curve and fail to accurately reflect the key performance parameters of the material such as high temperature plasticity and yield strength.

[0004] 2) Poor specimen alignment, resulting in eccentric force: When the specimen thickness is significantly smaller than the specified groove spacing of the fixture, such as a 0.5mm thin plate with a 3mm wide groove fixture, the specimen will tilt or wobble due to the mismatch in the groove spacing. In high-temperature environments, this tilt exacerbates the generation of non-axial load components, leading to premature buckling or shear deformation of the specimen. Although some laboratories have tried to alleviate the problem by adding shims, the shim gaps are difficult to completely eliminate, and instead introduce new sources of assembly error. Although the national standard GB / T228.2-2015 specifies the pin-type connection method for high-temperature tensile testing, it does not fully consider the special characteristics of thin plate testing, resulting in a large dispersion of test results. Utility Model Content

[0005] The purpose of this utility model is to provide a high-temperature tensile testing fixture for thin metal sheets, which has the advantages of simple operation, high reliability and convenient disassembly, and solves the problems in the prior art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A high-temperature tensile testing fixture for thin metal sheets includes an upper fixture and a lower fixture. Both the upper and lower fixtures have internally threaded holes at one end, and are threaded to a high-temperature tension rod via these holes. Both fixtures have a fixture groove and a pin through-hole in their middle sections. A thin sheet tensile specimen is inserted into the fixture groove, and a specimen end pin hole is formed at the end of the specimen, aligned horizontally with the pin through-hole. A clamping pin hole, penetrating the center of the pin through-hole, is located in the middle of the fixture groove. A pin inserted along the thickness direction of the thin sheet tensile specimen is placed in the clamping pin hole, with a pin through-hole in its middle and a pin groove at one end. The pin groove fits against the end of the thin sheet tensile specimen to limit the deformation space of the specimen end pin hole.

[0008] Preferably, the upper clamp and the lower clamp are detachably connected with pins. The pins pass through the pin through hole, the pin insertion through hole and the pin hole at the end of the sample in sequence along the horizontal direction, and are used to fix and lock the thin plate tensile sample, the pin and the upper clamp or the lower clamp.

[0009] It is worth noting that the pin is 40 mm long and 13.80 mm in diameter, and the pin through hole on the pin is 10 mm in diameter. However, it is necessary to ensure that the pin and the pin through hole, the pin hole at the end of the sample, and the pin through hole are compatible. If the hole diameter deviation is too large, it may cause difficulty in inserting the pin or loosening of the connection, affecting the locking effect.

[0010] Preferably, the pin is made of high-temperature alloy material, and the pin is clearance-fitted with the corresponding clamping slot pin hole on the upper and lower clamping bodies through its diameter, so as to achieve a tight connection with the upper and lower clamping bodies. The pin through hole of the pin is clearance-fitted with the pin through its diameter, so as to guide the pin through and lock it.

[0011] It is worth noting that high-temperature alloy materials possess excellent high-temperature resistance, strength, and stability, maintaining structural rigidity under high-temperature tensile testing conditions. This prevents the pin from softening and deforming due to high temperatures, ensuring reliable positioning and connection functions for the specimen and meeting the requirements of high-temperature testing scenarios. However, it is crucial to strictly control the gaps between the pin and the mounting hole of the clamp, as well as between the pin through hole and the pin. Excessive gaps will prevent a tight connection, while insufficient gaps may cause assembly jamming. Precise machining is necessary to ensure gap accuracy.

[0012] Preferably, the pin through hole is fitted with the pin through a clearance, allowing the pin to pass smoothly and form a coaxial positioning with the pin through hole and the pin hole at the end of the sample.

[0013] It is worth noting that the diameter of the pin through hole is 14 mm; however, it is necessary to ensure the coaxiality of the pin through hole, the insert pin through hole, and the pin hole at the end of the sample. If the coaxiality deviation is too large, the pin may get stuck when it is inserted, or even cause the pin hole or pin to deform, affecting the stability of the test and the service life of the parts.

[0014] Preferably, the axis of the pin through hole intersects perpendicularly with the central symmetry plane of the clamping body through groove, so as to realize that the force exerted on the sample when the pin is locked is distributed along the center of the upper clamping body and the lower clamping body.

[0015] It is worth noting that the axis of the pin through hole intersects perpendicularly with the center line of the through groove of the fixture. This ensures that the force direction of the specimen is consistent with the loading direction of the tensile tester, avoids eccentric stress, reduces the risk of specimen fracture in non-test areas, and improves the accuracy of test results. However, it is necessary to ensure the perpendicularity accuracy of the pin through hole axis and the center line of the through groove of the fixture during processing. If the perpendicularity is deviated, it will directly cause the specimen to be subjected to eccentric force, affecting the authenticity of the test data.

[0016] Preferably, the pin slot is located at one end of the pin, and the pin slot is adapted to the thickness of the thin plate tensile specimen to achieve a wrap-around limiting of the specimen clamping end.

[0017] It is worth noting that the distance between the edge of the slot and the end of the pin is millimeters; the width of the slot is 0.5 mm to 2.5 mm; however, it is necessary to select or process a pin of the corresponding width according to the sample specifications before the test.

[0018] Preferably, the center line of the clamping slot pin hole is located on the left and right symmetrical center plane of the upper or lower clamping body;

[0019] Only the slotted pin hole can be used to position the pin. The positioning accuracy of the pin through slot on the upper and lower clamping bodies is actually achieved by the perpendicularity of the pin through hole and the pin through slot machined on the pin 7.

[0020] It is worth noting that positioning by the center line of the pin ensures that the central axis of the specimen is collinear with the central axis of the clamp after the specimen is inserted into the through slot. This ensures that the stress on the specimen is distributed axially during tension, avoids eccentric stress, reduces specimen buckling or shear deformation, and improves the success rate and accuracy of the test results. However, it is important to confirm the installation direction of the pin during assembly to ensure that the center line of the pin through slot is precisely aligned with the central axis of the clamp, and to avoid misalignment failure due to reverse installation.

[0021] Preferably, the thickness of the thin plate tensile test specimen is adapted to the width of the pin slot of the pin.

[0022] It is worth noting that the width of the pin slot is customized according to the actual thickness of the thin plate tensile specimen, so that the pin fits tightly with the clamping end of the thin plate tensile specimen, eliminating the gap between the clamp and the specimen, and preventing the specimen from tilting or shaking during the tensile process; however, it is important to ensure that the tight fit is controlled within a reasonable range to avoid damage to the specimen clamping end due to interference fit, which would affect the test results.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] In this invention, the thin plate sample is fixed by a slotted pin without the need for any shims, which limits the deformation space of the sample pin hole and effectively solves the problem of test result distortion and test failure caused by excessive clamp clearance and deformation of the sample pin hole edge.

[0025] The slotted pin position corresponds to the center of the clamp body, ensuring good centering and coaxial clamping of the sample, avoiding eccentric stress and effectively improving the accuracy of test results.

[0026] The pin design is tightly integrated with the clamp body and pins, which can eliminate clamp gaps and prevent the sample from tilting or shaking; the friction force generated by the two orthogonal locking pins acts on two vertical planes, forming a very reliable mechanical interlock, ensuring that the sample is stable and does not slip during the tensile test; the device is simple to operate, highly reliable, and easy to disassemble. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the overall structure of this utility model;

[0028] Figure 2 This is a side view of the overall structure of this utility model;

[0029] Figure 3 This is a schematic diagram of the clamping body structure of this utility model;

[0030] Figure 4 This is a schematic diagram of the pin structure of this utility model;

[0031] Figure 5 This is a schematic diagram of the pin structure of this utility model;

[0032] Figure 6 This is a schematic diagram of the tensile test specimen structure of the metal sheet of this utility model.

[0033] Reference numerals: 1. Upper clamping body; 2. Lower clamping body; 3. Pin through hole; 301. Pin through hole; 4. Clamping groove pin hole; 5. Clamping body through groove; 6. Pin; 7. Pin; 8. Pin through groove; 9. Thin plate tensile specimen; 10. Specimen end pin hole. Detailed Implementation

[0034] 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.

[0035] To address the issue of poor stability in traditional fixtures in existing technologies, the following technical solution is proposed. Please refer to [link / reference needed]. Figure 1-6 ;

[0036] A high-temperature tensile testing fixture for thin metal sheets includes an upper fixture 1 and a lower fixture 2. Both the upper fixture 1 and the lower fixture 2 have internally threaded holes at one end, and are respectively connected to a high-temperature tension rod via these internally threaded holes. Both the upper fixture 1 and the lower fixture 2 have a fixture groove 5 and a pin through hole 3 in their middle sections. A thin sheet tensile specimen 9 is inserted into the fixture groove 5. The end of the thin sheet tensile specimen 9 has a specimen end pin hole 10, which is aligned horizontally with the pin through hole 3. A clamping groove pin hole 4, penetrating the center of the pin through hole 3, is located in the middle of the fixture groove 5. A pin 7, inserted along the thickness direction of the thin sheet tensile specimen 9, is located in the clamping groove pin hole 4. A pin through hole 301 is located in the middle of the pin 7, and a pin through groove 8 is located at one end of the pin 7. The pin through groove 8 fits against the end of the thin sheet tensile specimen 9 to limit the deformation space of the specimen end pin hole 10.

[0037] The upper clamping body 1 and the lower clamping body 2 are detachably connected by pins 6. Pins 6 pass horizontally through pin through holes 3, pin through holes 301, and sample end pin holes 10, respectively, to secure the thin plate tensile sample 9 and pins 7 to either the upper clamping body 1 or the lower clamping body 2. Pins 7 are made of high-temperature alloy material, and their diameter is clearance-fitted with the corresponding clamping groove pin holes 4 on the upper clamping body 1 and the lower clamping body 2, ensuring a tight connection. The pin through holes 301 of pins 7 are clearance-fitted with pins 6, guiding pins 6 through and locking them in place. The pin through holes 3 and 3 are clearance-fitted with pins 6. This allows the pin 6 to pass smoothly and form a coaxial positioning with the pin through hole 301 and the pin hole 10 at the end of the sample. The axis of the pin through hole 3 intersects perpendicularly with the central symmetry plane of the clamping body through groove 5, which is used to realize that the force on the sample when the pin 6 is locked is distributed along the center of the upper clamping body 1 and the lower clamping body 2. The pin through groove 8 opened on the pin 7 is located at one end of the pin 7. The pin through groove 8 is adapted to the thickness of the thin plate tensile sample 9 by its width, which is used to realize the wrap-around limit of the sample clamping end. The center line of the clamping groove pin hole 4 is located on the left and right symmetry center plane of the upper clamping body 1 or the lower clamping body 2. The thickness of the thin plate tensile sample 9 is adapted to the width of the pin through groove 8 of the pin 7.

[0038] Working principle: The upper clamping body 1 and the lower clamping body 2 are respectively connected to the upper and lower high-temperature tie rods by threads. One end of the thin plate tensile specimen 9 is inserted into the through groove 5 of the clamping body. The pin hole 10 at the end of the specimen is aligned with the pin through hole 3 of the clamping body. A pin 7 of a certain specification is inserted in the thickness direction of the specimen clamping end. The pin through groove 8 restricts the deformation space of the pin hole 10 at the end of the specimen. The pin through hole 301 is aligned with the pin through hole 3 and the pin hole 10 at the end of the specimen. Finally, the pin 6 is passed through the pin through hole 3, the pin through hole 301, and the pin hole 10 at the end of the specimen to fix and lock the specimen. Controlling the manufacturing precision of the clamping slot pin hole 4, the pin through slot 8, the pin through hole 301, and the pin 6 can effectively ensure that after the pin 7 is installed, the pin 6 is installed to position the pin 7 and the thin plate tensile specimen 9. This ensures that the central symmetry plane of the pin through slot 8 can be aligned with the central symmetry plane of the clamping slot 5. Through this cross-hole pin 7 design, the specimen can be firmly locked during the test, effectively limiting the deformation of the pin hole 10 at the end of the specimen, preventing the specimen from tilting or shaking, and greatly improving the success rate and accuracy of the test results.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A high-temperature tensile testing fixture for thin metal sheets, characterized in that, The device includes an upper clamping body (1) and a lower clamping body (2). One end of both the upper clamping body (1) and the lower clamping body (2) is provided with an internal threaded hole, and the upper clamping body (1) and the lower clamping body (2) are respectively connected to a high-temperature tie rod via the internal threaded hole. A clamping body through-slot (5) and a pin through-hole (3) are provided in the middle of both the upper clamping body (1) and the lower clamping body (2). A thin-plate tensile specimen (9) is inserted into the clamping body through-slot (5), and a specimen end pin hole (10) is provided at the end of the thin-plate tensile specimen (9). The pin hole (10) and the pin through hole (3) are aligned in the horizontal direction; the clamping body through groove (5) is provided with a clamping groove pin hole (4) that passes through the center of the pin through hole (3) from front to back. The clamping groove pin hole (4) is provided with a pin (7) inserted along the thickness direction of the thin plate tensile specimen (9). The pin (7) is provided with a pin through hole (301) in the middle. One end of the pin (7) is provided with a pin through groove (8). The pin through groove (8) fits with the end of the thin plate tensile specimen (9) to limit the deformation space of the pin hole (10) at the end of the specimen.

2. The high-temperature tensile testing fixture for thin metal sheets according to claim 1, characterized in that, The upper clamp (1) and lower clamp (2) are detachably connected with pins (6). The pins (6) pass through the pin through hole (3), the pin through hole (301) and the sample end pin hole (10) in the horizontal direction in sequence, which are used to fix and lock the thin plate tensile sample (9) and the pin (7) to the upper clamp (1) or the lower clamp (2).

3. The high-temperature tensile testing fixture for thin metal sheets according to claim 2, characterized in that, The pin (7) is made of high temperature alloy material, and the pin (7) is in clearance fit with the corresponding clamping slot pin hole (4) on the upper clamping body (1) and the lower clamping body (2) through its diameter, so as to achieve a tight connection with the upper clamping body (1) and the lower clamping body (2). The pin through hole (301) of the pin (7) is in clearance fit with the pin (6) through its diameter, so as to guide the pin (6) to pass through and lock.

4. The high-temperature tensile testing fixture for thin metal sheets according to claim 3, characterized in that, The pin through hole (3) is fitted with the pin (6) through a clearance fit, so that the pin (6) can pass through smoothly and form a coaxial positioning with the pin through hole (301) and the pin hole (10) at the end of the sample.

5. The high-temperature tensile testing fixture for thin metal sheets according to claim 4, characterized in that, The axis of the pin through hole (3) intersects perpendicularly with the central symmetry plane of the clamping body through groove (5), which is used to realize that the force on the sample when the pin (6) is locked is distributed along the center of the upper clamping body (1) and the lower clamping body (2).

6. The high-temperature tensile testing fixture for thin metal sheets according to claim 1, characterized in that, The pin slot (8) opened on the pin (7) is located at one end of the pin (7). The pin slot (8) is used to achieve a wrap-around limit on the clamping end of the specimen by adapting its width to the thickness of the thin plate tensile specimen (9).

7. The high-temperature tensile testing fixture for thin metal sheets according to claim 1, characterized in that, The center line of the clamping pin hole (4) is located on the left and right symmetrical center plane of the upper clamping body (1) or the lower clamping body (2).

8. The high-temperature tensile testing fixture for thin metal sheets according to claim 1, characterized in that, The thickness of the thin plate tensile test specimen (9) is adapted to the width of the pin slot (8) of the pin (7).

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