Clamp for tensile test of high-temperature pipe

Abstract

The utility model discloses a clamp for a tensile test of a high-temperature pipe. Wherein a plug core mounting threaded hole is formed in the center of the bottom of a cylinder top in the cylinder shell, the cylinder wall of the cylinder shell is arranged in the direction, facing the bottom, of the cylinder top, and threads used for mounting the cylindrical inner cavity are arranged in the cylinder wall of the cylinder shell; a coaxial circular truncated cone containing part is arranged in the center of the cylindrical shell, a large opening of the circular truncated cone containing part faces the direction of the cylinder top, and the three-petal wedge-shaped sleeve clamping component is arranged in the circular truncated cone containing part. The conical contact portion of the conical plug core abuts against the end face of the pipe to be measured from the inner side, the three-petal wedge-shaped sleeve clamping component is arranged on the periphery of the pipe to be measured in a pressing mode, and the outer side of the three-petal wedge-shaped sleeve clamping component and the wall face of the circular truncated cone containing portion are pressed. According to the utility model, the pipe is inserted into the three-petal wedge-shaped sleeve clamping part, and the plug core is also inserted into the pipe, so that the clamping end of the pipe is ensured not to have obvious plastic deformation, and abnormal fracture is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of testing the strength characteristics of solid materials by using mechanical stress, in particular to a clamp used for high-temperature pipe tensile testing. Background Art

[0002] As a key method for evaluating the mechanical properties of materials, tensile testing is widely used in the field of materials science. When conducting such tests, a secure grip of the specimen is essential to ensure the accuracy and reliability of the test results. However, traditional pipe clamp designs, such as wedge clamps and pliers, have drawbacks.

[0003] Among them, the operation process of the wedge-shaped clamp is cumbersome and inefficient, and the clamping process often causes plastic deformation of the specimen, affecting the accuracy of the test results; when the clamp-type clamp is performing a tensile test, due to the uneven distribution of clamping force, the pipe is prone to excessive deformation or even breakage at the clamping position, and the validity and reliability of the test data cannot be guaranteed.

[0004] In particular, in the high-temperature pipe tensile test environment, the clamp material softens due to high temperature, the clamping force of the wedge-shaped clamp and the pliers-type clamp is significantly weakened, and the specimen is very likely to slip, making the traditional clamp unable to meet the high-temperature test requirements. In addition, these traditional clamps are large in size and complex in structure, making it difficult to adapt to the limited space in the high-temperature furnace, which brings great inconvenience to the installation and use of the high-temperature tensile testing machine.

[0005] Therefore, a new type of fixture is needed to overcome the shortcomings of traditional fixtures in high temperature environments and ensure the accuracy and effectiveness of tensile tests. Utility Model Content

[0006] In view of the problems existing in the background technology, the utility model provides a clamp for tensile testing of high-temperature pipes to solve the problems in the prior art that the clamp is not effective, the specimen is prone to slipping or deformation and fracture, and thus it is difficult to ensure the accuracy and effectiveness of the test data. In order to achieve the above purpose, the utility model adopts the following technical scheme: including: a cylindrical shell, a cylindrical inner cavity, a conical plug and a three-petal wedge-shaped sleeve clamping component, wherein a testing machine connecting section is provided in the center of the top of the cylinder top in the cylindrical shell, and the outer periphery of the testing machine connecting section is provided with an external thread for connection with the testing machine; a plug installation threaded hole is provided in the center of the bottom of the cylinder top in the cylindrical shell, the cylinder wall of the cylindrical shell is arranged in the direction from the cylinder top to the bottom, and a thread for installing the cylindrical inner cavity is provided in the cylinder wall of the cylindrical shell; the cylindrical inner cavity is connected by threads It is installed in a cylindrical shell, and a coaxial truncated cone-shaped accommodation portion is provided in the center of the cylindrical shell, with the large mouth of the truncated cone-shaped accommodation portion facing the cylinder top, and a three-petal wedge-shaped sleeve clamping component is arranged in the truncated cone-shaped accommodation portion; one end of the conical plug is a threaded portion for threaded connection with the cylinder top of the cylindrical shell, and the other end of the conical plug is a conical contact portion, which presses against the end face of the pipe to be tested from the inside, and the three-petal wedge-shaped sleeve clamping component is pressed against the outer periphery of the pipe to be tested, and the outer side of the three-petal wedge-shaped sleeve clamping component is pressed against the wall surface of the truncated cone-shaped accommodation portion.

[0007] The three-petal wedge-shaped sleeve clamping component is composed of three identical wedge-shaped sleeve clamping components, and the inner side surface of each wedge-shaped sleeve clamping component is provided with anti-slip grooves.

[0008] The beneficial effects of the utility model are:

[0009] 1. The fixture has a simple structure and is easy to operate. The pipe is inserted into the three-petal wedge-shaped sleeve clamping component, and the plug is also inserted into the inner diameter of the pipe; the locking cylinder shell and the cylindrical inner cavity are locked by threads to ensure that the clamping end of the pipe will not have obvious plastic deformation and avoid abnormal fracture. Through unique structural design and optimization, the problems existing in the existing technology are effectively solved, providing a practical and efficient solution for high-temperature pipe tensile testing.

[0010] 2. A plugging core is provided in the inner cavity of the cylinder, which ensures that the pipe structure will not be deformed compared with the existing wedge-shaped clamps and clamp-type clamps, and also ensures the coaxiality requirements of the pipe sample.

[0011] 3. It has a self-locking function. When conducting a tensile test on a pipe, the cooperation of the clamping parts with the necking and the plugging core can increase the clamping force. In addition, the threaded locking of the cylindrical shell and the cylindrical inner cavity can effectively prevent the sample from slipping and falling out. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1The utility model is a cross-sectional schematic diagram of a fixture for high-temperature pipe tensile test with a pipe to be tested installed in the embodiment.

[0013] Figure 2 It is a longitudinal sectional schematic diagram of an embodiment of the utility model.

[0014] Figure 3 It is a schematic diagram of the structure of the three-petal wedge-shaped sleeve clamping component when it is laid flat in the embodiment of the utility model.

[0015] Wherein: 1-cylindrical outer shell, 2-cylindrical inner cavity, 3-truncated cone shaped accommodation portion, 4-conical plugging core, 5-three-petal wedge-shaped sleeve clamping component, 6-tube to be tested, 11-cylinder top, 12-cylinder wall, 41-threaded portion, 42-conical contact portion, 51-friction pattern, 111-testing machine connecting section, 112-plugging core mounting threaded hole. DETAILED DESCRIPTION

[0016] The following is a further detailed description of the utility model in conjunction with the accompanying drawings. The top, bottom, top and bottom in the description are descriptions made to clearly record the technical solution in conjunction with the accompanying drawings, rather than the directions in actual use, and do not restrict the scope of protection.

[0017] like Figure 1 to Figure 3 The embodiment of the utility model shown comprises: a cylindrical shell 1, a cylindrical inner cavity 2, a conical plugging core 4 and a three-petal wedge-shaped sleeve clamping component 5, wherein a testing machine connecting section 111 is provided at the top center of the cylinder top 11 in the cylindrical shell 1, and an external thread for connecting with a testing machine tension rod is provided on the outer periphery of the testing machine connecting section 111; a plugging core mounting threaded hole 112 is provided at the bottom center of the cylinder top in the cylindrical shell 1, a cylinder wall 12 of the cylindrical shell 1 is arranged in the direction from the cylinder top to the bottom, and a thread for mounting the cylindrical inner cavity 2 is provided in the cylinder wall of the cylindrical shell 1; the cylindrical inner cavity 2 is mounted in the cylindrical shell 1 by threaded connection, a coaxial truncated cone-shaped accommodation portion 3 is provided in the center of the cylindrical shell 1, and the large mouth of the truncated cone-shaped accommodation portion 3 faces the direction of the cylinder top 11, and the three-petal wedge-shaped sleeve clamping component 5 is arranged in the truncated cone-shaped accommodation portion 3, so that the outer shape of the three-petal wedge-shaped sleeve clamping component 5 matches the shape of the truncated cone-shaped accommodation portion 3 to ensure the accuracy and stability of assembly;

[0018] One end of the conical plug 4 is a threaded portion 41 for threaded connection with the cylinder top 11 of the cylindrical shell 1, and the other end of the conical plug 4 is a conical contact portion 42. The conical contact portion 42 presses against the end surface of the pipe to be tested 6 from the inside. The three-petal wedge-shaped sleeve clamping component 5 is pressed against the outer periphery of the pipe to be tested 6, and the outer side of the three-petal wedge-shaped sleeve clamping component 5 is pressed against the wall surface of the truncated cone shaped accommodation portion 3.

[0019] In this embodiment, Figure 3As shown, the three-petal wedge-shaped sleeve clamping component 5 is composed of three identical wedge-shaped sleeve clamping components, and the inner side surface of each wedge-shaped sleeve clamping component is provided with linear anti-skid patterns 51 for increasing the friction with the pipe wall, and the anti-skid patterns 51 are arranged along the circumferential direction.

[0020] In this embodiment, the outer shape of the cylindrical shell 1 includes but is not limited to a cylinder, with the goal of ensuring a compact structure and reducing processing difficulty.

[0021] When in use, the two embodiments are installed in pairs at both ends of the pipe 6 to be tested on a tensile testing machine with a high-temperature furnace:

[0022] First, select a suitable conical plug 4 and a three-petal wedge-shaped sleeve clamping component 5, wherein the small end and the large end of the conical plug 4 should be smaller and larger than the inner diameter of the pipe 6 to be tested, respectively; the inner diameter of the three-petal wedge-shaped sleeve clamping component 5 after closing should not be smaller than the outer diameter of the pipe 6 to be tested;

[0023] Then install the conical plug 4 into the top of the cylindrical shell 1;

[0024] Then, the pipe 6 to be tested is inserted into the truncated cone-shaped receiving portion 3, and then the three-petal wedge-shaped sleeve clamping component 5 is placed into the truncated cone-shaped receiving portion 3;

[0025] Finally, the cylindrical inner cavity 2 and the cylinder top 11 of the cylinder shell 1 are screwed together. During the final tightening process, the position of the three-petal wedge-shaped sleeve clamping component 5 is continuously adjusted to ensure that the pipe 6 to be tested, the conical plug 4 and the cylinder top 11 of the cylinder shell 1 are coaxial.

[0026] After both ends of the pipe 6 to be tested are installed, close the door of the heating furnace, set the temperature of the heating furnace to 300-900°C, and heat to the set temperature before conducting the tensile test on the tensile testing machine. It can be used for tensile performance and creep performance tests of pipes under different temperatures and speeds. It has a simple structure, convenient operation, and a small size. It meets the requirements of high-temperature tensile for compact fixture size, and can also ensure the coaxiality requirements of the tensile test and the credibility of the test data, and is practical.

Claims

1. A clamp for high temperature pipe tensile testing, characterized in that: include: A cylindrical shell (1), a cylindrical inner cavity (2), a conical plugging core (4) and a three-petal wedge-shaped sleeve clamping component (5), wherein a testing machine connecting section (111) is provided at the center of the top of the cylinder top (11) in the cylindrical shell (1), and an external thread for connecting to the testing machine is provided on the outer periphery of the testing machine connecting section (111); a plugging core mounting threaded hole (112) is provided at the center of the bottom of the cylinder top in the cylindrical shell (1); a cylinder wall (12) of the cylindrical shell (1) is arranged in a direction from the cylinder top to the bottom, and a thread for mounting the cylindrical inner cavity (2) is provided in the cylinder wall of the cylindrical shell (1); the cylindrical inner cavity (2) is mounted in the cylindrical shell (1) by threaded connection, and the cylindrical shell (1) ) is provided with a coaxial truncated cone-shaped accommodation portion (3) at the center thereof, the large opening of the truncated cone-shaped accommodation portion (3) faces the direction of the cylinder top (11), and the three-petal wedge-shaped sleeve clamping component (5) is arranged in the truncated cone-shaped accommodation portion (3); one end of the conical plug (4) is a threaded portion (41) for threaded connection with the cylinder top (11) of the cylinder shell (1), and the other end of the conical plug (4) is a conical contact portion (42), and the conical contact portion (42) presses against the end surface of the pipe to be tested (6) from the inside, and the three-petal wedge-shaped sleeve clamping component (5) is pressed against the outer periphery of the pipe to be tested (6), and the outer side of the three-petal wedge-shaped sleeve clamping component (5) is pressed against the wall surface of the truncated cone-shaped accommodation portion (3).

2. A clamp for high temperature pipe tensile testing according to claim 1, characterized in that: The three-petal wedge-shaped sleeve clamping component (5) is composed of three identical wedge-shaped sleeve clamping components, and the inner side surface of each wedge-shaped sleeve clamping component is provided with anti-slip grooves (51).

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