Persistent test hanging type sample connecting clamp capable of automatically adjusting coaxiality

Abstract

The utility model belongs to the technical field of creep durability tests of metal materials, and particularly relates to a durability test hanging type sample connecting clamp capable of automatically adjusting coaxiality, which is characterized in that an upper pull rod, a hanging type durability sample upper clamp, a hanging type durability sample, a hanging type durability sample lower clamp and a lower pull rod are connected in series and then are arranged on a durability testing machine; the hanging type lasting sample upper clamp and the hanging type lasting sample lower clamp are the same in structure, one end is a clamp base, the other end is a clamp spherical connector, a sample installation cavity used for being connected with a hanging type lasting sample is formed in the clamp base, and a center counter bore is formed in the sample installation cavity. The upper pull rod and the lower pull rod are the same in structure, one end is a pull rod base, the other end is a pull rod connecting threaded head, a spherical connector mounting cavity used for being connected with a clamp spherical connector is formed in the pull rod base, and a spherical connector sinking hole is formed in the spherical connector mounting cavity. The permanent test device has a high degree of freedom of movement, and the coaxiality of the permanent test is improved.

Description

Technical Field

[0001] This utility model belongs to the field of creep endurance testing technology for metallic materials, specifically a hanging specimen connection fixture for endurance testing that automatically adjusts coaxiality. Background Technology

[0002] A creep rupture testing machine is used to determine the creep strength of a material under a specified time, temperature, and constant tensile load. It simulates the deformation and failure process of materials under high temperature and high stress conditions. It has a wide range of applications in aerospace, energy, civil engineering, and manufacturing industries, and is a common piece of equipment used by metallurgical departments, research institutions, universities, and related factories and mines for material performance testing and research.

[0003] In high-temperature endurance testing of metallic materials, hanging specimen clamps are generally connected to tie rods via threads. Because the clamps and tie rods are repeatedly used during endurance testing, after prolonged exposure to high temperatures and loads, the connecting threads are prone to stripping, causing the clamps and tie rods to disengage. Localized thread stripping can also cause misalignment of the center lines between the clamps and tie rods, reducing coaxiality and potentially rendering the clamp unusable. Furthermore, the high-temperature oxidation and ablation caused by prolonged endurance testing can lead to the clamps and tie rods sticking together, making disassembly difficult or impossible. Utility Model Content

[0004] In order to solve the problems of slippage, reduced coaxiality, high-temperature oxidation and ablation, adhesion and difficulty in disassembling the fixture in the existing long-term test, the purpose of this utility model is to provide a hanging sample connection fixture for long-term test that automatically adjusts coaxiality.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] This utility model includes an upper pull rod, a hanging long-term specimen upper clamp, a hanging long-term specimen lower clamp, and a lower pull rod. Both ends of the hanging long-term specimen are connected to one end of the hanging long-term specimen upper clamp and one end of the hanging long-term specimen lower clamp, respectively. The other ends of the hanging long-term specimen upper clamp and the hanging long-term specimen lower clamp are connected to the upper pull rod and the lower pull rod, respectively. The upper pull rod, the hanging long-term specimen upper clamp, the hanging long-term specimen, the hanging long-term specimen lower clamp, and the lower pull rod are connected in series and installed on a long-term testing machine. The fixture has the same structure as the hanging permanent specimen clamp, with one end being a clamp base and the other end being a clamp spherical connector. The clamp base has a specimen mounting cavity for connecting with the hanging permanent specimen, and the specimen mounting cavity has a central countersunk hole. The upper pull rod has the same structure as the lower pull rod, with one end being a pull rod base and the other end being a pull rod connecting threaded head. The pull rod base has a spherical connector mounting cavity for connecting with the clamp spherical connector, and the spherical connector mounting cavity has a spherical connector countersunk hole.

[0007] Wherein: the spherical connector mounting cavity consists of interconnected partial spherical cavities, a spherical connector recessed hole, a central circular hole A, and a flared opening along the axial direction. The flared opening is located at the end of the pull rod base. After the clamp spherical connector enters the spherical connector mounting cavity through the partial spherical cavity, it moves axially to the spherical connector recessed hole.

[0008] The fixture base and the fixture spherical connector are connected by an arc-shaped transition section. The portion of the arc-shaped transition section located inside the spherical connector mounting cavity contacts the wall of the spherical connector's recessed hole and flared opening.

[0009] The diameters of the recessed hole and the central circular hole A of the spherical connector are equal, and are respectively smaller than the diameters of the partial spherical cavity and the trumpet-shaped opening.

[0010] The base of the pull rod is provided with a wrench-like surface for easy disassembly.

[0011] The connection between the threaded head of the pull rod and the base of the pull rod forms a frustum, the diameter of which is smaller than the outer diameter of both the threaded head and the base of the pull rod.

[0012] The sample mounting cavity consists of interconnected cylindrical cavities, a central countersunk hole, and a central circular hole B along the axial direction. The central circular hole B extends to the end of the fixture base. The hanging permanent sample enters the sample mounting cavity from the cylindrical cavity and moves axially to the central countersunk hole.

[0013] The diameter of the cylindrical cavity, the diameter of the central countersunk hole, and the diameter of the central circular hole B decrease sequentially.

[0014] The hanging permanent specimen has a parallel section in the middle and hanging specimen protrusions at both ends. There is a hanging specimen transition section between the hanging specimen protrusion and the parallel section at each end. The hanging specimen protrusion is inserted into the specimen mounting cavity and moves axially to the central countersunk hole.

[0015] The axial center lines of the upper pull rod, the upper clamp of the hanging permanent specimen, the hanging permanent specimen, the lower clamp of the hanging permanent specimen, and the lower pull rod connected in series are collinear.

[0016] The advantages and positive effects of this utility model are as follows:

[0017] 1. This utility model has a simple structure and is easy to install and remove. The clamp is connected to the upper and lower pull rods by a clamp ball connector, which has a high degree of freedom of movement. It can automatically adjust its position during the long-term test, thus improving the coaxiality of the long-term test.

[0018] 2. This utility model adopts a spherical connector for the clamp to connect with the spherical connector mounting cavity on the upper and lower pull rods. Unlike the traditional threaded connection, it improves the problems of slippage between the clamp and the pull rod after long-term high-temperature load use, as well as adhesion between the clamp and the pull rod due to high-temperature oxidation and ablation, which prevents disassembly. This extends the service life of the upper and lower pull rods and the upper and lower clamps of the hanging long-term sample, and reduces the cost of long-term testing.

[0019] 3. This utility model adopts a spherical connector for the clamp to be connected to the spherical connector mounting cavity on the upper and lower pull rods, which greatly improves the efficiency of disassembling the clamp. Especially after undergoing high temperature and long-term durability test, the advantages of this structural design are even more obvious. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the clamping and hanging sample of this utility model;

[0021] Figure 2 This is a front view of the structure of the hanging permanent sample upper (lower) clamp of this utility model;

[0022] Figure 3 This is a cross-sectional view of the internal structure of the hanging permanent sample clamp of this utility model;

[0023] Figure 4 for Figure 2 Sectional view A-A in the middle;

[0024] Figure 5 This is a front view of the structure of the upper (lower) tie rod of this utility model;

[0025] Figure 6 for Figure 5 The B-B section view in the diagram;

[0026] Figure 7 for Figure 5 C-C section view in the middle;

[0027] Figure 8 This is a three-dimensional structural diagram of the upper (lower) tie rod of this utility model;

[0028] Figure 9 This is a cross-sectional view of the internal structure of the upper (lower) tie rod of this utility model;

[0029] Figure 10 This is a schematic diagram of the structure of the hanging durable sample of this utility model;

[0030] Wherein: 1 is the upper pull rod, 101 is the pull rod connecting thread head, 102 is the frustum, 103 is the pull rod base, 104 is the spherical connector mounting cavity, 105 is the spherical connector countersunk hole, 106 is the central circular hole A, 107 is the trumpet-shaped opening, and 108 is the wrench plane; 2 is the hanging permanent specimen upper clamp, 201 is the clamp spherical connector, 202 is the arc-shaped transition connecting section, 203 is the clamp base, 204 is the specimen mounting cavity, 205 is the central countersunk hole, and 206 is the central circular hole B; 3 is the hanging permanent specimen, 301 is the hanging specimen boss, 302 is the hanging specimen transition section, and 303 is the hanging specimen parallel section; 4 is the hanging permanent specimen lower clamp, and 5 is the lower pull rod. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] like Figure 1 As shown, this utility model includes an upper pull rod 1, a hanging long-term specimen upper clamp 2, a hanging long-term specimen lower clamp 4, and a lower pull rod 5. Both ends of the hanging long-term specimen 3 are connected to one end of the hanging long-term specimen upper clamp 2 and the hanging long-term specimen lower clamp 4, respectively. The other ends of the hanging long-term specimen upper clamp 2 and the hanging long-term specimen lower clamp 4 are connected to the upper pull rod 1 and the lower pull rod 5, respectively. The upper pull rod 1, the hanging long-term specimen upper clamp 2, the hanging long-term specimen 3, the hanging long-term specimen lower clamp 4, and the lower pull rod 5 are connected in series as a whole and then installed on the loading system of the long-term testing machine. The axial center lines of the connected upper pull rod 1, the hanging long-term specimen upper clamp 2, the hanging long-term specimen 3, the hanging long-term specimen lower clamp 4, and the lower pull rod 5 are collinear.

[0033] like Figure 1 and Figure 10 As shown, in this embodiment, the hanging durable specimen 3 has a parallel section 303 in the middle and hanging specimen protrusions 301 at both ends. A transition section 302 connects each end of the hanging specimen protrusion 301 to the parallel section 303. The radial cross-sections of the hanging specimen protrusions 301, the transition sections 302, and the parallel sections 303 are all circular, and their outer diameters decrease sequentially.

[0034] like Figure 1 , Figures 2-4 and Figure 10As shown, the upper clamp 2 and lower clamp 4 of the hanging durable specimen in this embodiment have the same structure, with one end being a clamp base 203 and the other end being a clamp spherical connector 201. An arc-shaped transition section 202 connects the clamp base 203 and the clamp spherical connector 201. This arc-shaped transition section 202 increases the cross-sectional area of ​​the upper clamp 2 and lower clamp 4, improving their connection strength and service life. The clamp base 203 in this embodiment is cylindrical, and a specimen mounting cavity 204 for connecting to the hanging durable specimen 3 is provided on the clamp base 203. In this embodiment, the sample mounting cavity 204 consists of interconnected cylindrical cavities, a central countersunk hole 205, and a central circular hole B206 along the axial direction. The central circular hole B206 extends to the end of the fixture base 203. The diameters of the cylindrical cavities, the central countersunk hole 205, and the central circular hole B206 decrease sequentially. After the hanging sample boss 301 on the hanging durable sample 3 is inserted into the sample mounting cavity 204 from the cylindrical cavity, it moves axially to the central countersunk hole 205 to ensure that the position of the hanging durable sample 3 does not shift during the durability test. The hanging sample transition section 302 on the hanging durable sample 3 is located in the central circular hole B206.

[0035] In this embodiment, the diameter of the spherical connector 201 of the fixture is 0.5 to 0.8 times the diameter of the fixture base 203. The radial diameter of the cylindrical cavity in the sample mounting cavity 204 is 1.1 to 1.5 times the diameter of the hanging sample boss 301. The diameter of the central countersunk hole 205 is 1.05 to 1.1 times the diameter of the hanging sample transition section 302. The diameter of the central circular hole B206 is 1.05 to 1.2 times the diameter of the hanging sample parallel section 303. The axial length of the arc-shaped transition connection section 202 is 1.5 to 5 times the diameter of the fixture base 203.

[0036] like Figure 1 , Figures 5-10As shown, in this embodiment, the upper pull rod 1 and the lower pull rod 5 have the same structure. One end is a pull rod base 103, and the other end is a pull rod connecting thread head 101. A frustum 102 is formed between the pull rod connecting thread head 101 and the pull rod base 103. The pull rod connecting thread head 101 is used to connect with the loading system of the endurance testing machine. The diameter of the frustum 102 is smaller than the outer diameter of both the pull rod connecting thread head 101 and the pull rod base 103. In this embodiment, the pull rod base 103 is cylindrical. A spherical connector mounting cavity 104 for connecting with the spherical connector 201 of the clamp is provided on the pull rod base 103. The spherical connector mounting cavity 104 consists of interconnected spherical cavities, a spherical connector recessed hole 105, a central circular hole A106, and a trumpet-shaped opening 107 along the axial direction. The trumpet-shaped opening 107 is located at the end of the pull rod base 103. The diameters of the spherical connector recessed hole 105 and the central circular hole A106 are equal and respectively The diameter is smaller than that of the partial spherical cavity and the trumpet-shaped opening 107; after the spherical connector 201 enters the spherical connector mounting cavity 104 from the partial spherical cavity, it moves axially to the spherical connector recess 105, ensuring that the hanging permanent sample upper clamp 2 and the hanging permanent sample lower clamp 4 have sufficient freedom of movement and do not slide arbitrarily; the part of the arc-shaped transition connecting section 202 located in the spherical connector mounting cavity 104 contacts the hole wall of the spherical connector recess 105 and the trumpet-shaped opening 107.

[0037] In this embodiment, a wrench plane 108 is provided on the pull rod base 103 to facilitate disassembly. There are two wrench planes 108, which are symmetrically arranged along the axial center line of the pull rod base 103.

[0038] In this embodiment, a portion of the spherical cavity in the spherical connector mounting cavity 104 should be slightly larger than the clamp spherical connector 201. The radial diameter of the portion of the spherical cavity is 1.1 to 1.5 times the diameter of the clamp spherical connector 201. The countersunk hole 105 of the spherical connector should be slightly larger than the clamp spherical connector 201. The diameter of the countersunk hole 105 of the spherical connector is 1.05 to 1.2 times the diameter of the clamp spherical connector 201. The diameter of the central circular hole A106 is 1.1 to 1.5 times the diameter of the clamp spherical connector 201.

[0039] The working principle of this utility model is as follows:

[0040] Connect the upper pull rod 1 to the upper loading part of the endurance testing machine via the pull rod connecting thread head 101, and tighten it counterclockwise with a wrench at the wrench plane 108 position; insert the clamp ball joint 201 of the hanging endurance specimen upper clamp 2 radially into the ball joint mounting cavity 104 of the upper pull rod 1, and pull it axially downward to the ball joint countersunk hole 105, so that the clamp ball joint 201 and the ball joint countersunk hole 105 fit tightly together; insert the hanging specimen boss 301 of the hanging endurance specimen 3 radially from the specimen mounting cavity 204 of the hanging endurance specimen upper clamp 2, and pull it axially downward to the center countersunk hole 205, so that the lower end face of the hanging specimen boss 301 fits completely with the center countersunk hole 205, and ensure that the end faces are completely parallel; install the lower pull rod 5 and the hanging endurance specimen lower clamp 4 in the same way, and connect them to the lower loading part of the endurance testing machine. When the pull rod 5 is connected to the lower loading part of the endurance testing machine, the lower loading part of the endurance testing machine has a pull rod. One end of the pull rod is connected to the lower part of the endurance testing machine through a pull rod pin, and the other end of the pull rod is threaded to the pull rod connecting thread head 101 on the pull rod 5. Check if the upper tie rod 1, the upper clamp of the hanging long-term test specimen 2, the hanging long-term test specimen 3, the lower clamp of the hanging long-term test specimen 4, and the lower tie rod 5 are coaxial. Adjust the position of the tie rod in the lower loading part of the long-term test machine, clear the load to zero, insert the tie rod pin, apply the load, and tighten the upper clamp of the hanging long-term test specimen 2, the hanging long-term test specimen 3, and the lower clamp of the hanging long-term test specimen 4 to eliminate gaps. Confirm that the ball joint 201 of the clamp in the upper clamp of the hanging long-term test specimen 2 falls into the countersunk hole 105 of the ball joint of the upper tie rod 1, the ball joint 201 of the clamp in the lower clamp of the hanging long-term test specimen 4 falls into the countersunk hole 105 of the ball joint of the lower tie rod 5, and the hanging specimen bosses 301 at both ends of the hanging long-term test specimen 3 fall into the central countersunk hole 205 of the upper clamp of the hanging long-term test specimen 2 and the central countersunk hole 205 of the lower clamp of the hanging long-term test specimen 4, respectively. Finally, apply the preload, and the installation of the hanging long-term test specimen 3 is completed.

[0041] The clamp removal method is as follows: Pull out the pull rod pin on the loading system of the endurance testing machine, lift the pull rod 5 axially upward, so that the clamp ball joint 201 of the hanging endurance specimen lower clamp 4 exits the ball joint countersunk hole 105 of the pull rod 5, until the ball joint mounting cavity 104 of the pull rod 5 is parallel to or higher than the clamp ball joint 201 of the hanging endurance specimen lower clamp 4, push the clamp ball joint 201 of the hanging endurance specimen lower clamp 4 outward radially, loosen the pull rod 5 clockwise at the wrench plane 108 position of the pull rod 5; hold the hanging endurance specimen lower clamp 4 and push it axially upward, so that the hanging endurance specimen 3 One end of the hanging specimen boss 301 is disengaged from the central countersunk hole 205 of the hanging permanent specimen lower clamp 4, and moved to a position parallel to or lower than the specimen mounting cavity 204 of the hanging permanent specimen lower clamp 4. The hanging permanent specimen lower clamp 4 is then removed by translation. The hanging specimen parallel section 303 of the hanging permanent specimen 3 is grasped and pushed upward along the axial direction, so that the hanging specimen boss 301 at the other end of the hanging permanent specimen 3 is disengaged from the central countersunk hole 205 of the hanging permanent specimen upper clamp 2, and moved to a position parallel to or higher than the specimen mounting cavity 204 of the hanging permanent specimen upper clamp 2. The hanging permanent specimen 3 is then removed by translation. The removal methods of the hanging permanent specimen upper clamp 2 and the upper pull rod 1 are the same.

[0042] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A long-term test hanging specimen connection fixture with automatic coaxiality adjustment, characterized in that: The device includes an upper pull rod (1), a hanging long-term specimen upper clamp (2), a hanging long-term specimen lower clamp (4), and a lower pull rod (5). The two ends of the hanging long-term specimen (3) are connected to one end of the hanging long-term specimen upper clamp (2) and the hanging long-term specimen lower clamp (4), respectively. The other ends of the hanging long-term specimen upper clamp (2) and the hanging long-term specimen lower clamp (4) are connected to the upper pull rod (1) and the lower pull rod (5), respectively. The upper pull rod (1), the hanging long-term specimen upper clamp (2), the hanging long-term specimen (3), the hanging long-term specimen lower clamp (4), and the lower pull rod (5) are connected in series and installed on the long-term testing machine. The hanging long-term specimen upper clamp (2) and the hanging long-term specimen lower clamp (4) are connected... The upper pull rod (1) and the lower pull rod (5) have the same structure, with one end being a clamp base (203) and the other end being a clamp ball connector (201). The clamp base (203) has a sample mounting cavity (204) for connecting with the hanging permanent sample (3), and the sample mounting cavity (204) has a central countersunk hole (205). The upper pull rod (1) and the lower pull rod (5) have the same structure, with one end being a pull rod base (103) and the other end being a pull rod connecting thread head (101). The pull rod base (103) has a ball connector mounting cavity (104) for connecting with the clamp ball connector (201), and the ball connector mounting cavity (104) has a ball connector countersunk hole (105).

2. The automatic coaxiality adjustment hanging specimen connection fixture for long-term testing according to claim 1, characterized in that: The spherical connector mounting cavity (104) consists of interconnected spherical cavities, a spherical connector recessed hole (105), a central circular hole A (106), and a flared opening (107) along the axial direction. The flared opening (107) is located at the end of the pull rod base (103). The clamp spherical connector (201) enters the spherical connector mounting cavity (104) through the spherical cavity and then moves along the axial direction to the spherical connector recessed hole (105).

3. The automatic coaxiality adjustment hanging specimen connection fixture for long-term testing according to claim 2, characterized in that: The clamp base (203) and the clamp spherical connector (201) are connected by an arc-shaped transition section (202). The part of the arc-shaped transition section (202) located in the spherical connector mounting cavity (104) contacts the hole wall of the spherical connector recess (105) and the flared opening (107).

4. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 2, characterized in that: The diameters of the recessed hole (105) and the central circular hole A (106) of the spherical connector are equal, and are smaller than the diameters of the partial spherical cavity and the horn-shaped opening (107), respectively.

5. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 1, characterized in that: The pull rod base (103) is provided with a wrench surface (108) that facilitates disassembly.

6. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 1, characterized in that: The connection between the threaded head (101) of the pull rod and the base (103) is a frustum (102), and the diameter of the frustum (102) is smaller than the outer diameter of the threaded head (101) of the pull rod and the base (103).

7. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 1, characterized in that: The sample mounting cavity (204) consists of an interconnected cylindrical cavity, a central countersunk hole (205), and a central circular hole B (206) along the axial direction. The central circular hole B (206) extends to the end of the fixture base (203). The hanging permanent sample (3) enters the sample mounting cavity (204) from the cylindrical cavity and moves along the axial direction to the central countersunk hole (205).

8. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 7, characterized in that: The diameter of the cylindrical cavity, the diameter of the central countersunk hole (205), and the diameter of the central circular hole B (206) decrease sequentially.

9. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 1, characterized in that: The hanging permanent specimen (3) has a hanging specimen parallel section (303) in the middle and hanging specimen bosses (301) at both ends. There is a hanging specimen transition section (302) between the hanging specimen boss (301) and the hanging specimen parallel section (303) at each end. The hanging specimen boss (301) is inserted into the specimen mounting cavity (204) and moves axially to the central countersunk hole (205).

10. The long-term test hanging specimen connection fixture with automatic coaxiality adjustment according to claim 1, characterized in that: The axial center lines of the upper pull rod (1), the upper clamp of the hanging permanent specimen (2), the hanging permanent specimen (3), the lower clamp of the hanging permanent specimen (4), and the lower pull rod (5) connected in series are collinear.

Images