Tool for measuring percentage elongation after fracture and percentage reduction of area in tensile test

Abstract

The utility model belongs to the technical field of material tensile tests, and particularly discloses a tool for measuring percentage elongation after fracture and percentage reduction of area in a tensile test, which comprises two mounting seats, the distance between the two mounting seats can be adjusted, each mounting seat is provided with a sample loading hole, and the two sample loading holes are coaxial; an abutting piece is arranged in each sample loading hole, V-shaped grooves which are oppositely arranged are formed in the abutting pieces and the sample loading holes, and the structures of the V-shaped grooves are symmetrical; the movable rod is connected to the pressing piece and is used for driving the pressing piece to be far away from or close to the V-shaped groove of the sample loading hole. The connecting rod is fixed on one mounting seat, the other mounting seat is axially connected to the connecting rod in a sliding manner, and the locking piece is used for locking the positions of the mounting seats on the connecting rod. The two ends of the connecting rod are respectively fixed on the base and one of the mounting seats. According to the scheme, the problem that in the prior art, a tool used for assisting in measuring the percentage elongation after fracture and the end face shrinkage is poor in universality is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of material tensile testing, in particular to a tool for measuring elongation after fracture and section shrinkage rate in a tensile test. Background Art

[0002] The elongation after fracture of the mechanical properties of metal materials refers to the percentage of the elongated length of the test bar to the original length when the metal material breaks under the action of external force (tension). The cross-sectional shrinkage rate of the mechanical properties of metal materials refers to the percentage of the area of ​​the broken part of the test bar to the original area when the metal material breaks under the action of external force (tension).

[0003] The traditional manual method of measuring elongation and reduction of area is as follows: before the test, the gauge section is marked on the parallel section of the specimen surface (such as by dotting or using a marker); after the test, the test technician aligns the fracture ends of the broken specimen based on personal experience, measures the length of the gauge section and the diameter of the specimen at the fracture with a caliper, and finally calculates the elongation and reduction of area of ​​the specimen.

[0004] However, this traditional manual measurement method has the following problems: it is difficult to ensure the alignment requirements of the two ends of the sample during the measurement process (to ensure coaxiality) by relying solely on the personal experience of the technicians, and due to the differences in operating habits and operating strength among technicians, it is difficult to meet the repeatability and reproducibility requirements of the elongation test results by relying on personal experience; and when an irregular fracture appears on the sample after the test, it is difficult for the technicians to measure independently, and two or more people are required to complete the measurement collaboratively.

[0005] At present, most of the existing tools can only measure one of the elongation and the cross-sectional shrinkage, such as the rod-shaped tensile specimen elongation determination fixture with patent publication number / announcement number CN114577598A and the elongation detection device for metal material tensile test with CN214538944U. However, the existing comprehensive measurement tools for elongation and cross-sectional shrinkage have some other problems. For example, a new mechanical tensile elongation and cross-sectional shrinkage test tool with patent announcement number CN202583000U needs to hold the specimen with a pin when using the measuring device, and then control the rotation of the screw rod to adjust the distance between the movable plate and the fixed plate to achieve the splicing of the left and right broken specimens. This method has the following problems:

[0006] First, the sample is supported by a thimble. To ensure the coaxiality of the sample, the sample needs to have an end axial hole. However, the actual sample does not necessarily have an axial hole. For example, when the end of the sample is an external threaded cylindrical structure or a square structure, this device cannot be used for measurement, so its versatility is poor.

[0007] Secondly, because the tooling has a large base, if the sample needs to be measured again after the angle is changed, the sample needs to be disassembled and reinstalled; and in the test of elongation and cross-sectional shrinkage, multi-angle measurement is required to improve the test accuracy. Under the requirement of multi-angle measurement, multiple installations have to be carried out, and it is difficult to ensure the consistency of each installation, which not only increases the error caused by repeated loading, but also reduces the work efficiency in repeated loading.

[0008] Similarly, a device for auxiliary determination of cross-sectional shrinkage and elongation after fracture in a rod-shaped tensile test with patent announcement number CN207570920U also has the above-mentioned problems. Utility Model Content

[0009] The utility model aims to provide a tool for measuring elongation after fracture and cross-sectional shrinkage rate in a tensile test, so as to solve the problem of poor versatility of tools for auxiliary measurement of elongation after fracture and cross-sectional shrinkage rate in the prior art.

[0010] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0011] A tensile test elongation and cross-sectional shrinkage measurement tool comprises two mounting seats, the distance between the two mounting seats can be adjusted, each mounting seat is provided with a sample loading hole, and the two sample loading holes are coaxial; each sample loading hole is provided with a pressing piece, and the pressing piece and the sample loading hole are provided with V-shaped grooves arranged oppositely, and each V-shaped groove has a symmetrical structure; and also comprises a moving rod connected to the pressing piece, and the moving rod is used to drive the pressing piece to move away from or approach the V-shaped groove of the sample loading hole.

[0012] The principle and advantage of this scheme are as follows: since the ends of existing samples are either cylindrical or square, if this scheme is for samples with cylindrical ends, the ends of the samples are placed in the symmetrical V-grooves of the sample loading hole, and the movement of the moving rod to push the pressing piece is adjusted so that the two V-grooves clamp the ends of the samples in a four-point contact manner; if this scheme is for samples with square ends, the square ends are placed in the V-grooves, and the movement of the moving rod to push the pressing piece is adjusted so that the square ends are clamped by the two V-grooves in a surface contact manner, thereby fixing the ends of the samples. Compared with the existing technology, the versatility is improved.

[0013] In addition, the sample can also be clamped on a section of the cylinder near the end. Due to the presence of the movable rod, the enclosed space of the sample loading hole and the two V-grooves of the pressure piece can be adjusted, thereby meeting the clamping requirements of samples of different specifications and is not affected by the structure of the sample end, which greatly improves the versatility of this solution.

[0014] Preferably, as an improvement, the sample loading hole is provided with a first curved surface, the first curved surface on the sample loading hole is opposite to the V-shaped groove of the sample loading hole, and the pressing member is provided with a second curved surface facing the first curved surface, and the center line of the second curved surface, the center line of the first curved surface, and the center line of the V-shaped groove are all located on the same plane.

[0015] Beneficial effect: By setting the second arcuate surface and the first arcuate surface, the pressing member can quickly and accurately complete the position determination through the cooperation of the first arcuate surface and the second arcuate surface during the initial installation.

[0016] Preferably, as an improvement, the pressing member is slidably connected to the mounting seat.

[0017] Preferably, as an improvement, the moving rod is threadedly connected to the mounting seat to simplify the structure of the measuring tool.

[0018] Preferably, as an improvement, the pressing member is provided with a pushing groove, and the moving rod can extend into the pushing groove, so that the two can be quickly aligned during installation.

[0019] Preferably, as an improvement, it also includes a connecting rod fixed on one of the mounting seats, the remaining mounting seat is axially slidably connected to the connecting rod, and also includes a locking member for locking the mounting seat in position on the connecting rod.

[0020] Beneficial effect: When this solution is adopted, one of the mounting seats can move along the axial direction of the connecting rod to adjust the distance between the two mounting seats, which is convenient for assembling the sample; and after the assembly is completed, the position of the slidable mounting seat is locked by a locking piece, and after the installation position is locked, since the entire measuring device has a simple structure and the operating space between the mounting seats is large, it is convenient for the staff to flip the entire measuring tool with the sample, so as to perform measurements at different angles, avoiding the problem of repeated loading of samples in the prior art to achieve multi-angle measurement, and also avoiding the problem of reduced work efficiency caused by repeated loading of samples.

[0021] Preferably, as an improvement, the locking member has a screw, the screw is threadedly connected to the mounting seat, and one end of the screw screwed into the mounting seat can be tightly pressed against the connecting rod.

[0022] Beneficial effect: This solution makes the structure of the measuring tool simple and the cost low.

[0023] Preferably, as an improvement, it further includes a base, and both ends of the connecting rod are respectively fixed to the base and one of the mounting seats, so that the fixing of the connecting rod is more stable, which helps to ensure the stability of the movement of the movable mounting seat.

[0024] Preferably, as an improvement, the base and the mounting seat for fixing the connecting rod are both in the shape of a rectangular parallelepiped.

[0025] Beneficial effect: When this solution is adopted, the base and the rectangular mounting seat can be flipped, and after flipping 90 degrees, the entire measuring tool can still be well supported, thereby facilitating a worker to perform multi-angle measurement work.

[0026] Preferably, as an improvement, the number of the connecting rods is two, and the sample loading hole is located between the two connecting rods, so that the movable mounting seat is more stable when moving, which helps to ensure the coaxiality of the two mounting seats. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the utility model.

[0028] Figure 2 for Figure 1 Top view of the .

[0029] Figure 3 for Figure 2 AA section view in.

[0030] Figure 4 for Figure 2 BB section view in.

[0031] Figure 5 Different sample structures in the prior art. DETAILED DESCRIPTION

[0032] The following is further described in detail through specific implementation methods:

[0033] The reference numerals in the drawings of the specification include: fixed mounting seat 1, sample loading hole 10, first arc surface 11, movable mounting seat 2, base 3, connecting rod 4, locking member 5, pressing member 6, pushing groove 61, second arc surface 62, movable rod 7, and sample 8.

[0034] The embodiment is basically as shown in the attached Figures 1 to 4 Show.

[0035] A tensile test elongation and area shrinkage measurement tool, comprising a fixed mounting seat 1, a movable mounting seat 2 and a base 3 which are arranged in sequence, two symmetrical connecting rods 4 are detachably connected between the fixed mounting seat 1 and the base 3, the movable mounting seat 2 is slidably connected to the connecting rod 4, two locking members 5 are threadedly connected to the movable mounting seat 2, the locking members 5 are screws, each locking member 5 is threadedly connected to the mounting seat, and one end of each locking member 5 screwed into the mounting seat can be tightly pressed against the corresponding connecting rod 4.

[0036] The base 3 and the fixed mounting seat 1 are both in the shape of a rectangular parallelepiped. In this embodiment, the base 3 has the same height and width as the fixed mounting seat 1 along the axial direction of the connecting rod 4, and the height and width of the movable mounting seat 2 are smaller than those of the fixed mounting seat 1, so that when the measuring tool is flipped at an angle, the base 3 and the fixed mounting seat 1 can both support the measuring tool, thereby facilitating measurement after the angle changes.

[0037] The fixed mounting seat 1 and the movable mounting seat 2 are both processed with a sample loading hole 10, the two sample loading holes 10 are coaxially arranged, and the sample loading hole 10 is located in the middle of the fixed mounting seat 1 / the movable mounting seat;

[0038] Each sample loading hole 10 has a pressing member 6 in it. The pressing member 6 and the sample loading hole 10 are provided with V-shaped grooves arranged opposite to each other. Each V-shaped groove has a symmetrical structure. In this embodiment, the angle formed by the V-shaped groove is 90°.

[0039] The pressing member 6 is slidably connected to the corresponding mounting seat, and the fixed mounting seat 1 and the movable mounting seat are both threadedly connected with a moving rod 7. The end of the moving rod 7 facing the sample loading hole 10 is used to push the pressing member 6. After the moving rod 7 rotates, it can drive the pressing member 6 to approach / move away from the V-groove of the sample loading hole 10.

[0040] In order to facilitate the moving rod 7 to push the pressing member 6 , a pushing groove 61 is provided on the pressing member 6 , and the moving rod 7 can extend into the pushing groove 61 .

[0041] In order to facilitate the installation of the pressing member 6 and quickly align the pressing member 6 with the V-groove of the sample loading hole 10 during installation, a first curved surface 11 is processed on the sample loading hole 10, and the first curved surface 11 on the sample loading hole 10 is directly opposite to the V-groove of the sample loading hole 10. A second curved surface 62 facing the first curved surface 11 is processed on the pressing member 6, and the center line of the second curved surface 62, the center line of the first curved surface 11, and the center line of the V-groove are all located on the same plane.

[0042] When in use, the sample 8 is first placed in the sample loading holes 10 of the fixed mounting seat 1 and the movable mounting seat 2 , and the pressing member 6 is used to preliminarily fix the sample.

[0043] Then push the movable mounting base 2 to move along the connecting rod 4 to bring the fracture ends of the sample closer. After that, loosen one of the pressing parts 6 and adjust the angle of the sample to align the fracture ends of the broken sample 8. After the fracture ends are aligned, screw the movable rod 7 again so that the sample 8 is pressed tightly into the sample loading hole 10 by the pressing part 6.

[0044] Finally, the position of the movable mounting seat 2 on the connecting rod 4 is adjusted so that the fracture ends of the sample 8 are fully in contact with each other, and then the locking piece 5 is screwed so that the locking piece 5 fixes the movable mounting seat 2 on the connecting rod 4 .

[0045] This embodiment has the following advantages:

[0046] 1. When the present embodiment is used, in the case where the sample is fixedly clamped from the end, whether the end of the sample is cylindrical or square, the fixed clamping can be achieved with the cooperation of the sample loading hole 10 with the V-groove and the pressing member 6, thus ensuring the versatility of the present embodiment.

[0047] Second, after the sample is fixed, a technician can measure the sample at different angles independently by simply flipping the measuring tool without repeatedly disassembling the sample, achieving one-time clamping and multiple multi-angle measurements, greatly reducing measurement errors. In addition, the sample centering and the degree of sample adhesion are good by using the cooperation of the sample loading hole 10 with V-grooves and the pressing piece 6, which greatly improves the coaxiality and the repeatability and reproducibility of the measurement results, ensuring the measurement stability.

[0048] 3. This embodiment has a simple structure, and a large operating space near the sample after installation, which can facilitate the measurement of the data required for the elongation after fracture and the data required for the cross-sectional shrinkage rate, thereby simultaneously satisfying the measurement functions of the elongation after fracture and the cross-sectional shrinkage rate.

[0049] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A tensile test elongation and area reduction measurement tool, comprising two mounting seats, the distance between the two mounting seats being adjustable, characterized in that: Each mounting seat is provided with a sample loading hole, and the two sample loading holes are coaxial; Each sample loading hole is provided with a pressing piece, and the pressing piece and the sample loading hole are provided with V-shaped grooves arranged opposite to each other, and each V-shaped groove has a symmetrical structure; The utility model also comprises a moving rod connected to the pressing member, and the moving rod is used for driving the pressing member to move away from or approach the V-shaped groove of the sample loading hole.

2. A tensile test elongation and area reduction measurement tool according to claim 1, characterized in that: The sample loading hole is provided with a first curved surface, the first curved surface on the sample loading hole is opposite to the V-shaped groove of the sample loading hole, the pressing member is provided with a second curved surface facing the first curved surface, and the center line of the second curved surface, the center line of the first curved surface and the center line of the V-shaped groove are all located on the same plane.

3. A tensile test elongation and area reduction measurement tool according to claim 1, characterized in that: The pressing piece is slidably connected to the mounting seat.

4. A tensile test elongation and area reduction measurement tool according to claim 3, characterized in that: The moving rod is threadedly connected to the mounting seat.

5. A tensile test elongation and area reduction measurement tool according to claim 4, characterized in that: The pressing piece is provided with a pushing groove, and the moving rod can extend into the pushing groove.

6. A tensile test elongation and area reduction measurement tool according to any one of claims 1 to 5, characterized in that: It also includes a connecting rod fixed on one of the mounting seats, the remaining mounting seat is axially slidably connected to the connecting rod, and also includes a locking member for locking the mounting seat on the connecting rod.

7. A tensile test elongation and area reduction measurement tool according to claim 6, characterized in that: The locking piece is provided with a screw, which is threadedly connected to the mounting seat, and one end of the screw screwed into the mounting seat can be tightly pressed against the connecting rod.

8. A tensile test elongation and area reduction measurement tool according to claim 6, characterized in that: It also includes a base, and two ends of the connecting rod are respectively fixed on the base and one of the mounting seats.

9. A tensile test elongation and area reduction measurement tool according to claim 8, characterized in that: The base and the mounting seat for fixing the connecting rod are both in the shape of a rectangular parallelepiped.

10. A tensile test elongation and area reduction measurement tool according to claim 6, characterized in that: There are two connecting rods, and the sample loading hole is located between the two connecting rods.

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