Rapid clamping and releasing mechanism for dynamic tensile test

Abstract

The invention relates to the technical field of material tensile tests, and provides a dynamic tensile test rapid clamping and releasing mechanism which comprises a hydraulic cylinder connected with a hydraulic power assembly; the elastic energy storage element is mounted on the cylinder body of the hydraulic cylinder; the tool bottom plate is fixed to a piston rod of the hydraulic cylinder and compresses the elastic energy storage element under the thrust action of the piston rod; the upper pull rod and the lower pull rod are jointly connected with a test piece, and a conical clamped part is arranged at the lower end of the lower pull rod; the clamping component comprises a clamping base fixed to the tool bottom plate and a plurality of clamping jaws arranged at intervals in the circumferential direction, and the lower ends of the clamping jaws are hinged to the clamping base; the cover plate is fixed relative to the cylinder body of the hydraulic cylinder, and a conical hole for extruding the upper end of the clamping jaw is formed in the cover plate, so that the conical clamped part is clamped by the clamping jaw; and the position detection element is used for sending a release signal when the upper pull rod is loaded to a target position. According to the invention, the test piece can be quickly released when being stretched to a specific distance, so that the mechanical property of the metal material when dynamic stretching is stopped is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of material tensile testing, in particular to a quick clamping and releasing mechanism for dynamic tensile testing. Background Art

[0002] When designing nuclear power structures, it's important to consider the impact of strong earthquake impact loads on the mechanical properties of materials. The strain rates of impact loads under strong earthquakes are primarily concentrated at low to medium strain rates, necessitating the use of a material testing machine to measure the dynamic tensile and dynamic fracture properties of materials at these low and medium strain rates. During the dynamic tensile test, the lower fixture clamps the lower portion of the specimen, while the upper fixture applies a preload to the upper portion. The upper fixture is connected to the loading component of the material testing machine to achieve high-speed tensile testing of the specimen.

[0003] However, during high-speed stretching, the upper clamp reaches the top of the material testing machine, completely breaking the specimen. The entire dynamic tensile test cannot be stopped midway, and the material cannot be released from the clamp at the set displacement, making it impossible to obtain the material's mechanical and material performance parameters at this time. Therefore, providing a mechanism that allows the metal material being tested to be stretched at a high loading rate in a material testing machine and then released instantaneously for a specific period of time (i.e., the specimen is instantly released from the force after being stretched to a certain extent) to obtain the mechanical properties of the metal material at the time the dynamic stretching stops is an urgent problem to be solved in this field. Summary of the Invention

[0004] The object of the present invention is to provide a quick clamping and releasing mechanism for dynamic tensile testing, so as to solve the defect that existing material testing machines cannot achieve instantaneous release of metal materials at a specific time after being stretched at a high loading rate.

[0005] The present invention is achieved through the following technical solutions:

[0006] A dynamic tensile test quick clamping and releasing mechanism, comprising:

[0007] a hydraulic cylinder connected to a hydraulic power assembly;

[0008] The elastic energy storage element is installed on the cylinder body of the hydraulic cylinder;

[0009] The tooling base plate is fixed to the piston rod of the hydraulic cylinder and compresses the elastic energy storage element under the thrust of the piston rod;

[0010] The upper pull rod and the lower pull rod are used to connect the test piece together, and the lower end of the lower pull rod is provided with a tapered clamping portion;

[0011] The clamping component includes a clamping base fixed on the tooling base and a plurality of clamping jaws spaced apart along the circumferential direction, wherein the lower ends of the clamping jaws are hinged to the clamping base;

[0012] The cover plate is fixed relative to the cylinder body of the hydraulic cylinder and is provided with a tapered hole inside for squeezing the upper end of the clamping claw so that the clamping claw can clamp the tapered clamped part;

[0013] and a position detection element to send a release signal when the upper pull rod is loaded to the target position. The hydraulic cylinder then unloads, and the tooling base plate is ejected downward under the action of the elastic energy storage element, causing the clamp to release the lower pull rod.

[0014] Optionally, a support shaft is provided on the clamping jaw near the lower end, and a first torsion spring is sleeved on the support shaft to keep the clamping jaw in a tendency to open outward.

[0015] Optionally, an upper connecting ear is provided at the lower end of the upper pull rod, and a lower connecting ear is provided at the upper end of the lower pull rod, and the upper connecting ear and the lower connecting ear are connected to the test piece via a pin shaft.

[0016] Optionally, the upper connecting ear is connected to the upper pull rod via a threaded connection, and the lower pull rod is connected to the lower connecting ear via a threaded connection.

[0017] Optionally, the elastic energy storage element is mounted on the cylinder body of the hydraulic cylinder through a mounting bracket, the mounting bracket includes a mounting block and two support rods, the support rods are fixedly connected to the top of the cylinder body, the mounting block is connected to the upper ends of the two support rods, the upper end of the elastic energy storage element is fixedly connected to the mounting block, and the lower end of the elastic energy storage element is against the tooling base plate.

[0018] Optionally, the position detection element is a displacement sensor.

[0019] Optionally, the position detection element is a travel switch, the travel switch and the cylinder body of the hydraulic cylinder are relatively fixed in position, and the upper pull rod is connected to a touch piece for triggering the travel switch.

[0020] Optionally, the touch member is a plate-shaped structure, one end of the touch member is rotatably connected to the upper pull rod via a pin shaft, and the pin shaft is sleeved with a second torsion spring to keep the touch member in an upward rotation tendency, and the upper pull rod is provided with a limit member above the touch member for limiting the upward rotation of the touch member.

[0021] Optionally, the hydraulic power assembly includes an oil tank, a servo motor, an oil pump, a reversing valve and a logic valve; the servo motor drives the oil pump to supply oil to the lower chamber of the hydraulic cylinder through the oil supply line, so that the piston rod of the hydraulic cylinder extends upward; the lower chamber of the hydraulic cylinder is connected to the oil tank through the return oil line via the logic valve and the reversing valve, and the reversing valve reverses after receiving a release signal, controls the logic valve to relieve pressure, and allows the hydraulic oil in the lower chamber of the hydraulic cylinder to flow back to the oil tank through the logic valve.

[0022] Optionally, the hydraulic power assembly further includes an overflow valve, which is arranged on an overflow pipeline, one end of the overflow pipeline is connected to the oil tank, and the other end of the overflow pipeline is connected to the oil supply pipeline.

[0023] The technical solution of the present invention has at least the following advantages and beneficial effects: In the present invention, the workpiece is connected between the upper pull rod and the lower pull rod. After the piston rod of the hydraulic cylinder is extended, the elastic energy storage element is in an energy storage and compression state under the squeezing action of the tooling base plate. At the same time, the clamping claw is squeezed by the tapered hole in the cover plate and contracts inward to clamp the tapered clamping portion of the lower pull rod. During the test, the upper pull rod is connected to the loading component of the material testing machine. The loading component drives the upper pull rod to rise, and the lower pull rod is fixed and kept stationary by the clamping claw. After the upper pull rod is loaded to the target position (that is, the specimen is stretched to the target distance), the position detection element reaches the trigger condition and sends a release signal. After the hydraulic power assembly receives the release signal, the hydraulic cylinder unloads, and at the same time, the elastic energy storage element releases energy. The tooling base plate and the piston rod of the hydraulic cylinder generate a large acceleration under the action of the elastic energy storage component, and are instantly ejected downward. The clamping claw also follows the downward movement and is no longer squeezed by the tapered hole in the cover plate. The lower pull rod is released, and the specimen is quickly released, so that the specimen is freed from the stress, thereby obtaining the mechanical properties of the metal material when dynamic stretching stops. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic structural diagram of a quick clamping and releasing mechanism for a dynamic tensile test provided in Example 1;

[0025] Figure 2 It is a schematic diagram of the installation structure of the elastic energy storage element and the cover plate;

[0026] Figure 3 is a schematic diagram of the clamping state of the clamping component;

[0027] Figure 4 It is a structural diagram of the clamping component;

[0028] Figure 5 Schematic diagram of the structure of the upper pull rod and the lower pull rod;

[0029] Figure 6 is the structural diagram of the specimen;

[0030] Figure 7 This is the working principle diagram of the hydraulic power component;

[0031] Figure 8 A schematic structural diagram of a quick clamping and releasing mechanism for a dynamic tensile test provided in Example 2;

[0032] Figure 9 Schematic diagram of the connection structure of the touch member in Example 2;

[0033] Figure 10 Schematic diagram of the connection structure of the travel switch in Example 2;

[0034] Figure markings: 1-hydraulic cylinder, 101-piston rod, 102-cylinder body, 2-elastic energy storage element, 3-mounting frame, 301-mounting block, 302-support rod, 4-upper pull rod, 401-upper connecting ear, 5-lower pull rod, 501-lower connecting ear, 502-clamped part, 6-tooling base, 7-clamping component, 701-clamping seat, 702-clamping claw, 703-first torsion spring, 8-cover plate, 9-connecting seat, 10-position detection element, 11-connecting bracket, 12-touch member, 13-limiting member, 14-oil tank, 15-servo motor, 16-oil pump, 17-reversing valve, 18-logic valve, 19-overflow valve, 20-check valve, 21-filter, 22-temperature sensor, 23-pressure sensor, 24-test piece. DETAILED DESCRIPTION

[0035] Example 1

[0036] refer to Figure 1 , a dynamic tensile test quick clamping and releasing mechanism, comprising a hydraulic cylinder 1, an elastic energy storage element 2, a tooling base plate 6, an upper pull rod 4, a lower pull rod 5, a clamping component 7, a cover plate 8 and a position detection element 10. The release mechanism provided by the present invention is used in conjunction with an existing material testing machine. There is no restriction on the specific type of material testing machine, as long as it can apply a tensile load to the material. As an option, for example, this embodiment adopts an Instron VHS160 / 100-20 high-speed material testing machine, that is, the Instron brand VHS series, a high-speed material testing machine with a model of 160 / 100-20. In actual application, a material testing machine (not shown) is used as a basic stand, and the hydraulic cylinder 1 is used as the main body. The various components are installed and integrated into a whole, which can be quickly installed on the base of the material testing machine. A force sensor can be set at the bottom of the hydraulic cylinder 1 to facilitate the detection of tensile loads.

[0037] The hydraulic cylinder 1 is connected to a hydraulic power assembly that realizes oil supply and oil return, that is, the hydraulic cylinder 1 realizes the loading and unloading of hydraulic oil through the hydraulic power assembly. Figure 2 The elastic energy storage element 2 is installed on the cylinder body 102 of the hydraulic cylinder 1, and the tooling base plate 6 is fixedly connected to the piston rod 101 of the hydraulic cylinder 1. Under the thrust of the piston rod 101, the tooling base plate 6 compresses the elastic energy storage element 2 to store energy.

[0038] refer to Figure 3-Figure 5, the upper pull rod 4 and the lower pull rod 5 are connected to the test piece 24 together, and the lower end of the lower pull rod 5 is provided with a tapered clamping portion 502; the clamping component 7 includes a clamping seat 701 fixed on the tooling base 6 and a plurality of clamping claws 702 arranged at intervals along the circumferential direction, and the lower ends of the clamping claws 702 are hinged to the clamping seat 701; the cover plate 8 is relatively fixed to the cylinder body 102 of the hydraulic cylinder 1, and a tapered hole is provided inside for squeezing the upper end of the clamping claw 702. After the piston rod 101 of the hydraulic cylinder 1 is extended, the clamping component 7 follows and rises, and the clamping claw 702 is gradually squeezed by the tapered hole inside the cover plate 8 until the tapered clamping portion 502 of the lower pull rod 5 is clamped (the clamping state is as shown in FIG. Figure 3 shown).

[0039] During the test, the upper pull rod 4 is connected to the loading component of the material testing machine, and the loading component drives the upper pull rod 4 to rise, and the lower pull rod 5 is fixed by the clamp 702 and remains motionless. After the upper pull rod 4 is loaded to the target position (that is, the specimen 24 is stretched to the target distance), the position detection element 10 reaches the trigger condition and sends a release signal. After the hydraulic power assembly receives the release signal, the hydraulic cylinder 1 unloads, and at the same time the elastic energy storage element 2 releases energy. The tooling base 6 and the piston rod 101 of the hydraulic cylinder 1 generate a large acceleration under the action of the elastic energy storage component, and are instantly ejected downward. The clamp 702 also follows the downward movement and is no longer squeezed by the tapered hole inside the cover plate 8. The lower pull rod 5 is released, realizing the rapid release of the specimen 24, so that the specimen 24 is freed from the force, thereby obtaining the mechanical properties of the metal material when dynamic stretching stops.

[0040] In this embodiment, the lower end of the upper pull rod 4 is provided with an upper connecting ear 401, and the upper end of the lower pull rod 5 is provided with a lower connecting ear 501. The upper connecting ear 401 and the lower connecting ear 501 are connected to the specimen 24 through a pin. It should be understood that two pin holes should be provided on the specimen 24 (refer to Figure 6 Furthermore, the upper connecting ear 401 is connected to the upper pull rod 4 by a thread, and the lower pull rod 5 is connected to the lower connecting ear 501 by a thread, which is convenient for processing, manufacturing and assembly.

[0041] As an option, four clamping jaws 702 are provided in this embodiment. In other embodiments, the number of clamping jaws 702 can of course be set to other numbers. Furthermore, in this embodiment, a support shaft is provided near the lower end of the clamping jaw 702, and a first torsion spring 703 is sleeved on the support shaft. Under the action of the first torsion spring 703, the clamping jaws 702 maintain a tendency to open outward, so that when the clamping jaws 702 are not squeezed by the tapered hole inside the cover plate 8, a large gap is left between the clamping jaws 702 so that the lower end of the lower pull rod 5 can be inserted into the gap between the clamping jaws 702 from the top of the cover plate 8. After the piston rod 101 of the hydraulic cylinder 1 is extended, the clamping jaws 702 are gradually squeezed by the tapered hole inside the cover plate 8 (while the first torsion spring 703 accumulates energy) until they clamp the tapered clamped portion 502 at the lower end of the lower pull rod 5. After the lower pull rod 5 is subsequently released, the clamping jaws 702 are quickly reset under the action of the first torsion spring 703.

[0042] Reference again Figure 2 , two elastic energy storage elements 2 are symmetrically arranged to ensure uniform force. As an option, the elastic energy storage element 2 of this embodiment is a nitrogen spring. It should be understood that the nitrogen spring uses high-pressure nitrogen as the medium, has a high compression ratio, high energy storage density, and fast response, which facilitates the rapid release of the test piece 24. In addition, the nitrogen spring has the advantages of constant elastic force, small size, long life (over 1 million times), strong adjustability, and flexible installation. In other embodiments, the nitrogen spring can of course be replaced by other elements, such as a hydraulic spring.

[0043] As an option, the elastic energy storage element 2 is installed on the cylinder body 102 of the hydraulic cylinder 1 through the mounting bracket 3. Specifically, the mounting bracket 3 includes a mounting block 301 and two support rods 302. The support rods 302 are fixedly connected to the top of the cylinder body 102. The mounting block 301 is connected to the upper ends of the two support rods 302. The upper end of the elastic energy storage element 2 is fixedly connected to the mounting block 301, and the lower end of the elastic energy storage element 2 is against the tooling base plate 6.

[0044] Based on the above, in this embodiment, the cover plate 8 is secured relative to the cylinder body 102 of the hydraulic cylinder 1 as follows: a connecting seat 9 is provided on the support rod 302. The connecting seat 9 is supported by a step on the support rod 302 and is secured by a nut connected to the support rod 302. As will be readily understood, the support rod 302 is threaded. The cover plate 8 is secured to the connecting seat 9 via screws. In other embodiments, the cover plate 8 can of course be secured relative to the cylinder body 102 of the hydraulic cylinder 1 using other means, such as providing a support member at the top of the cylinder body 102, to which the cover plate 8 is screwed.

[0045] In this embodiment, the position detection element 10 is a displacement sensor. The release signal is electronically triggered. When the displacement sensor detects that the upper pull rod 4 has been loaded to the target position (i.e., the specimen 24 has been stretched to the target distance), it sends a release signal to the hydraulic power assembly. In practice, a displacement sensor (not shown) can be mounted on the upper pull rod 4.

[0046] refer to Figure 7 In this embodiment, the hydraulic power assembly includes an oil tank 14, a servo motor 15, an oil pump 16, a relief valve 19, a reversing valve 17, and a logic valve 18. Optionally, the oil pump 16 can be a plunger pump. The servo motor 15 drives the oil pump 16 to supply oil to the lower chamber of the hydraulic cylinder 1 through the oil supply line, causing the piston rod 101 of the hydraulic cylinder 1 to extend upward. The relief valve 19 is located on the relief line, one end of which is connected to the oil tank 14 and the other end to the oil supply line. The lower chamber of the hydraulic cylinder 1 is connected to the oil tank 14 via the oil return line, through the logic valve 18 and the reversing valve 17. Upon receiving a release signal, the reversing valve 17 switches direction, controlling the logic valve 18 to relieve pressure, allowing the oil in the lower chamber of the hydraulic cylinder 1 to flow back to the oil tank 14 through the logic valve 18. In actual application, a one-way valve 20 and a filter 21 should be provided on the end of the oil supply line close to the oil tank 14. A temperature sensor 22 for detecting the internal hydraulic oil temperature is provided on the oil tank 14. In order to accurately control the pressure, a pressure sensor 23 can also be provided on the oil supply line.

[0047] There is no restriction on the brands and models of the various electrical components. For example, in this embodiment, the brand of the displacement sensor is Omron, and the model is Z4D-C01; the brand of the servo motor 15 is Shenzhen Huichuan Technology, and the model is MS1 H1-10C30CB; the brand of the oil pump 16 is Guiyang Haizhili, and the model is HYC-MP1 F0.65B; the brand of the overflow valve 19 is Ningbo Ketai, and the model is LRV-08; the brand of the reversing valve 17 is Ningbo Ketai, and the model is LSV6-12-2NOSP; the brand of the logic valve 18 is Beijing Huade, and the model is LC32B05E7X; the brand of the one-way valve 20 is Ningbo Ketai, and the model is CVR2000-G14; the brand of the filter 21 is Xinxiang Tongyuan, and the model is FLDA; the brand of the temperature sensor 22 is Beijing Xingyi, and the model is CWD-Z11; the brand of the pressure sensor 23 is Holywell, and the model is GPTJG3YG400BSCHX.

[0048] In actual applications, each electrical component is connected to the control system of the material testing machine to facilitate automatic control. It should be understood that controlling the operation of each electrical component through the control system can be achieved by those skilled in the art based on existing technology and common knowledge in the field, and is not an improvement point of the present invention. Therefore, it will not be elaborated in this embodiment.

[0049] Example 2

[0050] refer to Figure 8 The difference between this embodiment and embodiment 1 is that the position detection element 10 in this embodiment is selected differently. Specifically, the position detection element 10 in this embodiment selects a travel switch, that is, the release signal is triggered mechanically.

[0051] refer to Figure 10 The travel switch is relatively fixed to the cylinder body 102 of the hydraulic cylinder 1. As an option, the travel switch of this embodiment is installed as follows: the travel switch is installed on the connecting bracket 11, which is mounted on the support rod 302 and locked with nuts at the top and bottom. In this way, the height of the connecting bracket 11 can be easily adjusted, thereby achieving height adjustment of the travel switch to accommodate different types of test pieces 24. In other embodiments, the travel switch can of course be installed in other ways, for example, the travel switch can be installed on a fixed component of the material testing machine.

[0052] refer to Figure 9 The upper pull rod 4 is connected to a contact member 12 for triggering the travel switch. When the upper pull rod 4 is subjected to a tensile load (i.e., the upper pull rod 4 moves upward) under the action of the material testing machine, the contact member 12 touches the travel switch. As an option, the contact member 12 is a plate-shaped structure, one end of which is rotatably connected to the upper pull rod 4 via a pin, and a second torsion spring is sleeved on the pin to keep the contact member 12 in an upward rotation trend. The upper pull rod 4 is provided with a limit member 13 above the contact member 12 for limiting the upward rotation of the contact member 12. Under the action of the limit member 13, the contact member 12 remains parallel to the tooling base 6. Preferably, the limit member 13 is replaced by a screw. It is worth noting that such a setting ensures that the contact member 12 can trigger the travel switch while allowing the contact member 12 to rotate downward, thereby avoiding a hard collision between the contact member 12 and the travel switch due to setting errors or failures, thereby avoiding damage to the travel switch and its connecting structure.

[0053] Based on the above, the workflow of the release mechanism is divided into three stages: test preparation stage, standby stage and rapid release stage, as follows.

[0054] Test preparation stage: The servo motor 15 works to drive the oil pump 16 to rotate and provide a power source. The reversing valve 17 is normally closed and is in the left working state in the figure. The logic valve 18 controls the chamber pressure to increase. The logic valve 18 is in a closed state. The hydraulic oil flows to the lower chamber of the hydraulic cylinder 1. The piston rod 101 of the hydraulic cylinder 1 moves upward to the highest point under the action of the hydraulic oil. The elastic energy storage element 2 is in an energy storage compression state under the action of the thrust of the piston rod 101. At the same time, the clamping jaw 702 clamps the conical clamping portion 502 of the lower pull rod 5 under the squeezing of the conical hole inside the cover plate 8, thereby fixing the lower pull rod 5.

[0055] Standby stage: When the piston rod 101 of the hydraulic cylinder 1 is at its highest point, the servo motor 15 continues to run at a low speed to maintain the pressure in the hydraulic cylinder 1. When the servo motor 15 is on standby to maintain pressure, the overflow valve 19 continues to overflow and generate heat. The temperature sensor 22 detects the temperature of the hydraulic oil and issues an alarm when it reaches a certain temperature value. When it exceeds the set value, the motor is controlled to stop. Therefore, the standby state should not be too long.

[0056] Quick release stage: the upper pull rod 4 is stretched vertically upward at a constant speed under the action of the material testing machine. When it is stretched to the target position, the touch member 12 triggers the travel switch, thereby obtaining a release signal (it is easy to understand that in Example 1, the displacement sensor detects that the release signal is obtained when the upper pull rod 4 is stretched to the target position). The release signal is transmitted to the reversing valve 17, which controls the reversing valve 17 to be in the right working state in the figure. The control chamber of the logic valve 18 is depressurized, and the hydraulic oil in the lower chamber of the hydraulic cylinder 1 is discharged to the oil tank 14 at a large flow rate through the logic valve 18, thereby unloading the hydraulic cylinder 1. At the same time, the elastic energy storage element 2 releases energy, and the tooling base plate 6, the clamping component and the piston rod 101 of the hydraulic cylinder 1 generate a large acceleration under the action of the elastic energy storage component, and are instantly ejected downward. The clamping claw 702 also follows the downward movement and is no longer squeezed by the tapered hole inside the cover plate 8. The lower pull rod 5 is loosened, thereby achieving a quick release of the test piece 24 and freeing the test piece 24 from stress.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A dynamic tensile test quick clamping and releasing mechanism, characterized in that: include: a hydraulic cylinder connected to a hydraulic power assembly; The elastic energy storage element is installed on the cylinder body of the hydraulic cylinder; The tooling base plate is fixed to the piston rod of the hydraulic cylinder and compresses the elastic energy storage element under the thrust of the piston rod; The upper pull rod and the lower pull rod are used to connect the test piece together, and the lower end of the lower pull rod is provided with a tapered clamping portion; The clamping component includes a clamping base fixed on the tooling base and a plurality of clamping jaws spaced apart along the circumferential direction, wherein the lower ends of the clamping jaws are hinged to the clamping base; The cover plate is fixed relative to the cylinder body of the hydraulic cylinder and is provided with a tapered hole inside for squeezing the upper end of the clamping claw so that the clamping claw can clamp the tapered clamped part; and a position detection element to send a release signal when the upper pull rod is loaded to the target position. The hydraulic cylinder then unloads, and the tooling base plate is ejected downward under the action of the elastic energy storage element, causing the clamp to release the lower pull rod.

2. The dynamic tensile test quick clamping and releasing mechanism according to claim 1, characterized in that: A support shaft is passed through the clamping jaw near the lower end, and a first torsion spring is sleeved on the support shaft to keep the clamping jaw in a tendency to open outwards.

3. The dynamic tensile test quick clamping and releasing mechanism according to claim 1, characterized in that: An upper connecting ear is provided at the lower end of the upper pull rod, and a lower connecting ear is provided at the upper end of the lower pull rod. The upper connecting ear and the lower connecting ear are connected to the test piece through a pin shaft.

4. The dynamic tensile test quick clamping and releasing mechanism according to claim 3, characterized in that: The upper connecting ear is connected to the upper pull rod through threads, and the lower pull rod is connected to the lower connecting ear through threads.

5. The dynamic tensile test quick clamping and releasing mechanism according to claim 1, characterized in that: The elastic energy storage element is installed on the cylinder body of the hydraulic cylinder through a mounting bracket. The mounting bracket includes a mounting block and two support rods. The support rods are fixedly connected to the top of the cylinder body. The mounting block is connected to the upper ends of the two support rods. The upper end of the elastic energy storage element is fixedly connected to the mounting block, and the lower end of the elastic energy storage element is against the tooling base plate.

6. The dynamic tensile test quick clamping and releasing mechanism according to claim 1, characterized in that: The position detection element is a displacement sensor.

7. The dynamic tensile test quick clamping and releasing mechanism according to claim 1, characterized in that: The position detection element is a travel switch, the travel switch and the cylinder body of the hydraulic cylinder are relatively fixed in position, and the upper pull rod is connected to a touch piece for triggering the travel switch.

8. The dynamic tensile test quick clamping and releasing mechanism according to claim 7, characterized in that: The touch member is a plate-shaped structure, one end of which is rotatably connected to the upper pull rod via a pin shaft, and the pin shaft is sleeved with a second torsion spring to keep the touch member in an upward rotation trend. The upper pull rod is provided with a limit member above the touch member for limiting the upward rotation of the touch member.

9. The dynamic tensile test quick clamping and releasing mechanism according to any one of claims 1 to 8, characterized in that: The hydraulic power assembly includes an oil tank, a servo motor, an oil pump, a reversing valve and a logic valve; the servo motor drives the oil pump to supply oil to the lower chamber of the hydraulic cylinder through the oil supply pipeline, so that the piston rod of the hydraulic cylinder extends upward; the lower chamber of the hydraulic cylinder is connected to the oil tank through the return oil pipeline via the logic valve and the reversing valve. The reversing valve reverses after receiving a release signal, controls the logic valve to relieve pressure, and allows the hydraulic oil in the lower chamber of the hydraulic cylinder to flow back to the oil tank through the logic valve.

10. The dynamic tensile test quick clamping and releasing mechanism according to claim 9, characterized in that: The hydraulic power assembly further comprises an overflow valve, which is arranged on an overflow pipeline. One end of the overflow pipeline is connected to the oil tank, and the other end of the overflow pipeline is connected to the oil supply pipeline.

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