Bar sample clamping tool of bar tensile testing machine

Abstract

A bar sample clamping tool of a bar tensile testing machine comprises an upper clamping device and a lower clamping device, and each clamping device comprises a fixing bar, a bar clamp and a steel ring; threads are arranged at the upper end of the fixing rod, and a convex circle structure is arranged at the lower end of the fixing rod. The bar clamp is a trapezoidal hollow cylindrical pipe; four cylindrical holes with different sizes are sequentially formed in the hollow cylindrical pipe from top to bottom; a conical hole is formed in the inner diameter of the steel ring; according to the utility model, a V-shaped or plane clamp is optimized, and a proper sample structure and size are designed, so that the requirements of a short R4 sample and a bar sample tensile test of a conventional wire rod are met. The technical problem that in a traditional clamping mode, due to the fact that the length of a clamping part is limited, when a V-shaped or plane clamp arranged on a conventional universal testing machine is used, clamping is difficult is solved. The total machining length of the sample is shortened, so that the overall machining efficiency of the sample is improved, and raw material resources are effectively saved.

Description

Technical Field

[0001] This utility model relates to a bar specimen clamping tool for a bar tensile testing machine, belonging to the field of tensile testing technology. Background Technology

[0002] The GB / T228.1-2021 standard explicitly lists R2, R4, and R7 specimens as recommended standard tensile test specimens, with R4 being the most commonly used. Furthermore, according to the testing machine usage specifications, during routine tensile testing, at least two-thirds of the specimen's clamping end must be completely within the clamps; in terms of specific length, this translates to a clamping end length of 50 to 60 mm. The total specimen length also has specific requirements: when using R4 standard and V-shaped or flat clamps, the total specimen length should be at least 170 to 190 mm. It is worth noting that the standard further elaborates on the relationship between the total specimen length and the clamping method, stating that the determination of the total specimen length Lt depends on the clamping method and follows a basic principle: Lt should be greater than the sum of the specimen's parallel length Lc and four times the original specimen diameter d0. In other words, as long as the specimen clamps meet the requirements and the specimen satisfies the condition that Lt is greater than 95 mm, the total specimen length is considered to meet the requirements.

[0003] In traditional clamping methods, due to insufficient specimen length, the clamping portion is too short when processing R4 specimens according to GB / T 228.1-2021, leading to clamping difficulties when using V-clamps or flat clamps equipped on conventional universal testing machines. Therefore, there is an urgent need to propose a new bar specimen clamping tool for bar tensile testing machines, customizing the tensile specimen dimensions based on the specific design of the clamp. By optimizing the specimen design, the total processing length of the specimen can be shortened, thereby improving the overall efficiency of specimen processing and effectively saving raw material resources. Utility Model Content

[0004] This invention aims to solve the problem of difficulty in clamping samples using conventional universal testing machines when the sample length is insufficient and the clamping part is too short, due to the traditional clamping method.

[0005] The technical solution of this utility model:

[0006] A bar specimen clamping tool for a bar tensile testing machine includes upper and lower clamping devices, wherein the clamping devices include a fixed bar, a bar clamp, and a steel ring;

[0007] One end of the fixing rod is provided with a thread, and the other end of the fixing rod is provided with a convex structure;

[0008] The threads on the fixing rod are used to connect with the V-shaped clamp thread of the tensile testing machine; the rod clamp is a truncated cone hollow tube, formed by the interlocking of two arc-shaped halves; the interior of the truncated cone hollow tube has four cylindrical holes of different sizes arranged in sequence: a first cylindrical hole, a second cylindrical hole, a third cylindrical hole, and a fourth cylindrical hole; the convex circular structure on the fixing rod is fitted into the second cylindrical hole; the tensile specimen is fitted into the third cylindrical hole;

[0009] The inner hole of the steel ring is tapered, and the steel ring is fitted onto the bar clamp to ensure tight fixation with the bar clamp and the tensile specimen.

[0010] Furthermore, the fixing rod has a diameter of φ30mm and a total length of 280mm; the upper end of the fixing rod is provided with an M30 threaded thread with a length of 80mm.

[0011] Furthermore, the convex circular structure is designed to be φ37mm*5mm.

[0012] Furthermore, the clamp is a trapezoidal hollow cylindrical tube with an upper outer diameter of 50mm, a lower outer diameter of 54mm, and an overall height of 75mm; the first cylindrical hole is φ14mm*12mm, the second cylindrical hole is φ28mm*20mm, the third cylindrical hole is φ38mm*26mm, and the fourth cylindrical hole is φ30mm*14mm; the four cylindrical holes are smoothly transitioned by a 1mm arc angle.

[0013] Furthermore, the outer diameter of the steel ring is 66mm, the upper inner diameter is 52mm, the lower inner diameter is 54mm, and the length is 30mm.

[0014] This utility model has the following beneficial effects:

[0015] This application optimizes V-shaped or planar clamps and designs suitable specimen structures and dimensions to meet the tensile testing requirements of short R4 specimens and conventional wire and bar specimens. This enables the tensile testing machine to test a wider variety of specimens. It solves the technical problem of clamping difficulties encountered when using V-shaped or planar clamps on conventional universal testing machines due to the limited length of the clamping area in traditional clamping methods. By optimizing the specimen design, the total processing length of the specimen is shortened, thereby improving the overall efficiency of specimen processing and effectively saving raw material resources. Attached Figure Description

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 This is a schematic diagram of the tensile testing machine.

[0018] Figure 2 This is a schematic diagram of the clamping device structure;

[0019] Figure 3 This is a schematic diagram of the fixed rod structure;

[0020] Figure 4 This is a schematic diagram of the fixture structure;

[0021] Figure 5 This is a schematic diagram of a steel ring structure;

[0022] Figure 6 This is a diagram of a tensile specimen.

[0023] Figure label:

[0024] In the figure, 1-fixed rod, 2-bar clamp, 3-steel ring, 4-tensile specimen, 11-thread, 12-convex structure, 21-first cylindrical hole, 22-second cylindrical hole, 23-third cylindrical hole, 24-fourth cylindrical hole. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the present utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0026] Example:

[0027] Combination Figures 1-6 This embodiment describes a bar specimen clamping tool for a bar tensile testing machine, comprising upper and lower clamping devices, wherein the clamping devices include a fixed bar 1, a bar clamp 2, and a steel ring 3;

[0028] One end of the fixing rod 1 is provided with a thread 11, and the other end of the fixing rod 1 is provided with a convex structure 12;

[0029] The thread 11 on the fixing rod 1 is used to connect with the V-shaped clamp of the tensile testing machine; the rod clamp 2 is a truncated cone hollow tube, formed by the interlocking of two arc-shaped halves; the interior of the truncated cone hollow tube has four cylindrical holes of different sizes arranged in sequence: first cylindrical hole 21, second cylindrical hole 22, third cylindrical hole 23, and fourth cylindrical hole 24; the convex circular structure 12 on the fixing rod 1 is fitted into the second cylindrical hole 22; the tensile specimen 4 is fitted into the third cylindrical hole 23;

[0030] The inner hole of the steel ring 3 is a tapered hole. The steel ring 3 is fitted onto the bar clamp 2 to ensure tight fixation with the bar clamp and the tensile specimen 4.

[0031] Furthermore, the fixing rod 1 has a diameter of φ30mm and a total length of 280mm; the thread 11 is an M30 thread with a length of 80mm.

[0032] Furthermore, the convex circular structure 12 is designed to be φ37mm*5mm.

[0033] Furthermore, the clamp 2 is a trapezoidal hollow cylindrical tube with an upper outer diameter of 50mm and a lower outer diameter of 54mm, and an overall height of 75mm; the first cylindrical hole 21 is φ14mm*12mm, the second cylindrical hole 22 is φ28mm*20mm, the third cylindrical hole 23 is φ38mm*26mm, and the fourth cylindrical hole 24 is φ30mm*14mm; the four cylindrical holes are smoothly transitioned by a 1mm arc angle.

[0034] Furthermore, the outer diameter of the steel ring 3 is 66mm, the upper inner diameter is 52mm, the lower inner diameter is 54mm, and the length is 30mm.

[0035] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A bar specimen clamping tool for a bar tensile testing machine, characterized in that, It includes two sets of clamping devices, one above the other, each clamping device including a fixed rod (1), a rod clamp (2), and a steel ring (3); One end of the fixing rod (1) is provided with a thread (11), and the other end of the fixing rod (1) is provided with a convex structure (12); The thread (11) on the fixing rod (1) is used to connect with the V-shaped clamp thread of the tensile testing machine; the rod clamp (2) is a truncated cone hollow tube, which is formed by the interlocking of two arc-shaped bodies; the interior of the truncated cone hollow tube has four cylindrical holes of different sizes arranged in sequence: the first cylindrical hole (21), the second cylindrical hole (22), the third cylindrical hole (23), and the fourth cylindrical hole (24); the convex circular structure (12) on the fixing rod (1) is fitted and installed in the second cylindrical hole (22); the tensile specimen (4) is fitted and installed in the third cylindrical hole (23); The inner hole of the steel ring (3) is a tapered hole. The steel ring (3) is fitted onto the bar clamp (2) to ensure tight fixation with the bar clamp and the tensile specimen (4).

2. The bar specimen clamping tool of the bar tensile testing machine according to claim 1, characterized in that, The fixing rod (1) has a diameter of φ30mm and a total length of 280mm; the upper end of the fixing rod (1) is provided with a thread (11) of M30 thread and a length of 80mm.

3. The bar specimen clamping tool of the bar tensile testing machine according to claim 2, characterized in that, Furthermore, the convex circular structure (12) is designed to be φ37mm*5mm.

4. The bar specimen clamping tool of the bar tensile testing machine according to claim 3, characterized in that, The clamp (2) is a trapezoidal hollow cylindrical tube with an upper outer diameter of 50mm and a lower outer diameter of 54mm, and an overall height of 75mm; the first cylindrical hole (21) is φ14mm*12mm, the second cylindrical hole (22) is φ28mm*20mm, the third cylindrical hole (23) is φ38mm*26mm, and the fourth cylindrical hole (24) is φ30mm*14mm; the four cylindrical holes are smoothly transitioned by a 1mm arc angle.

5. The bar specimen clamping tool of the bar tensile testing machine according to claim 4, characterized in that, The outer diameter of the steel ring (3) is 66mm, the upper inner diameter is 52mm, the lower inner diameter is 54mm, and the length is 30mm.

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