Hopkinson pull rod clamp

Abstract

The invention discloses a Hopkinson pull rod clamp which comprises a clamp body, a fixed clamping block axially extending from one end of the clamp body, a movable clamping block arranged opposite to the fixed clamping block, and a fastening mechanism for applying clamping force to the fixed clamping block and the movable clamping block, through the combination of the clamp body in modular design and the detachable clamping assembly and the combination of the fastening mechanism and the standardized interface, different clamping assemblies can be directly replaced to realize lossless dynamic clamping of different types of test pieces, so that the test precision and the equipment universality are improved, and the test efficiency is improved. The problems of slippage distortion caused by a conical surface gap and stress concentration caused by threaded connection of an existing device are solved, the stability and reliability of a Hopkinson pull rod test are remarkably improved, and the dynamic mechanical data acquisition efficiency of a complex test piece is improved.

Description

Technical Field

[0001] The invention relates to a material dynamic mechanical property testing technology, in particular to a Hopkinson pull rod clamp. Background Art

[0002] The Hopkinson bar test is an important method for studying the dynamic mechanical properties of materials at high strain rates. Its core lies in analyzing the dynamic response of the specimen through stress wave transmission. Existing fixtures mainly use threaded connections, conical surface fits or adhesive fixation to clamp the specimen and the tie rod. However, existing devices have significant limitations in practical applications: threaded or conical surface fits are prone to assembly gaps due to processing tolerances, resulting in interference from noise during stress wave propagation and reduced test accuracy; although adhesive fixation can reduce stress concentration, residual glue needs to be cleaned after each test, which is inefficient and cannot be reused. In addition, existing fixtures are mostly designed for specific specimens and lack versatility. When changing the specimen type, the fixture needs to be replaced as a whole, which increases the experimental cost and operational complexity. Summary of the Invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a Hopkinson tie rod clamp with high precision, high efficiency and high adaptability.

[0004] Technical solution: The Hopkinson pull rod clamp described in the present invention includes a clamp body, a fixed clamping block axially extending from one end of the clamp body, a movable clamping block arranged opposite to the fixed clamping block, and a fastening mechanism for applying axial clamping force to the fixed clamping block and the movable clamping block; an axial connecting port is provided at the other end of the clamp body; a detachable clamping assembly is provided on the opposing surfaces of the fixed clamping block and the movable clamping block, and the detachable clamping assembly is easy to replace and can adapt to the clamping requirements of different specimens; the fastening mechanism is connected across the fixed clamping block and the movable clamping block to provide stable clamping.

[0005] Preferably, the working surface of the clamping assembly is provided with an anti-slip texture to enhance friction, prevent the specimen from slipping, and improve test accuracy; the anti-slip texture includes at least one of corrugations, serrations, or discrete protrusions.

[0006] Preferably, positioning grooves are provided on the sides of the fixed clamping block and the movable clamping block, and the fastening mechanism includes a locking bolt and a clamping block that cooperates with the positioning groove. The locking bolt passes through the clamping block horizontally and applies axial pre-tightening force to improve assembly accuracy, reduce gaps, evenly distribute pre-tightening force, and avoid stress concentration.

[0007] Preferably, the clamp body and the fixing clamp block are fixed by at least one of integral casting, welding or bolt connection.

[0008] Preferably, the axial connection port is a threaded interface, and the threaded interface is a standardized interface, the diameter of which is consistent with the diameter of the Hopkinson rod, and a sealing ring is provided on the end face of the interface, which has strong compatibility, ensures the connection seal, and prevents loosening and vibration interference.

[0009] Preferably, the surface of the locking bolt of the fastening mechanism is provided with a wear-resistant coating, and the wear-resistant coating is titanium nitride or diamond-like carbon coating, which extends the service life of the device, reduces maintenance, and ensures stable clamping force.

[0010] Preferably, anti-slip gaskets are provided between the clamping block and the positioning grooves of the fixed clamping block and the movable clamping block to prevent the clamping block from shifting.

[0011] Preferably, the threaded portion of the locking bolt is provided with an anti-loosening structure, which keeps the bolt tight in a vibrating environment, avoids accidental loosening, and ensures safety.

[0012] Preferably, the fastening mechanism is further provided with a quick release assembly to improve operational efficiency.

[0013] Preferably, a rotary dust cover is provided at the outer end of the axial connection port, and the dust cover is hinged to the clamp body through a rotating shaft. The design of the dust cover protects the interface, prevents dust from affecting the connection, and prolongs the service life.

[0014] Beneficial effects: Compared with the existing technology, the present invention has the following significant advantages: through the combination of a modularly designed fixture body and a detachable clamping component, and combined with a fastening mechanism and a standardized interface, different clamping components can be directly replaced to achieve non-destructive dynamic clamping of different types of specimens, which not only improves the test accuracy and equipment versatility, but also solves the problems of slip distortion caused by conical surface gap and stress concentration caused by threaded connection in existing devices, significantly improves the stability and reliability of the Hopkinson pull rod test, and improves the efficiency of dynamic mechanical data acquisition of complex specimens. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is a schematic diagram of the connection between the clamp body and the fixed clamp block of the present invention.

[0017] Figure 3 It is a schematic diagram of the structure of the movable clamp of the present invention.

[0018] Figure 4 It is a schematic diagram of the clamping block structure of the present invention.

[0019] Figure 5 It is a schematic diagram of the locking bolt structure of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0021] like Figure 1-5 As shown, a Hopkinson pull rod clamp in this embodiment mainly consists of three main parts: a clamp body 1, a clamping part and a fastening mechanism 4, wherein the clamping part is divided into a fixed clamping block 2 fixedly connected to the end of the clamp body 1 and a movable clamping block 3 arranged opposite to the fixed clamping block 2. The clamp body 1 and the fixed clamping block 2 are fixedly connected by integral casting to ensure the firmness and integrity of the connection. A detachable clamping assembly 5 is provided on the opposite surfaces of the fixed clamping block 2 and the movable clamping block 3. The clamping assembly 5 can be replaced according to the different shapes and sizes of the specimen to meet the clamping requirements of various specimens. A corrugated anti-slip texture is provided on the working surface of the clamping assembly 5 to enhance the friction between it and time, prevent the specimen from slipping during the dynamic test, and thus improve the test accuracy.

[0022] The other end of the fixture body 1 is equipped with an axial connection port 6. This axial connection port 6 is a standardized threaded interface with a diameter consistent with that of the Hopkinson rod, ensuring compatibility and connection stability. A sealing ring is installed on the end face of the interface to effectively prevent the ingress of dust and other impurities, while also preventing loosening of the connection due to vibration during testing.

[0023] The fastening mechanism 4 spans between the fixed clamping block 2 and the movable clamping block 3 and specifically comprises a locking bolt 7 and a clamping block 8 that engages with lateral positioning grooves in the fixed and movable clamping blocks 2 and 3. The locking bolt 7 extends transversely through the clamping block 8 and applies an axial preload. By evenly tightening the locking bolt 7, the clamping block 8 stably clamps the fixed and movable clamping blocks 2 and 3, avoiding stress concentration and improving assembly precision. A titanium nitride wear-resistant coating is applied to the surface of the locking bolt 7, significantly improving the bolt's wear resistance, extending the device's service life, reducing maintenance frequency, and ensuring stable clamping force.

[0024] Anti-slip pads are placed between the clamping block 8 and the positioning slots of the fixed clamping block 2 and the movable clamping block 3 to effectively prevent the clamping block 8 from shifting during the clamping process, ensuring uniform distribution of the clamping force. Furthermore, the threaded portion of the locking bolt 7 is equipped with an anti-loosening structure, such as a lock nut or retaining washer, to ensure that the bolt remains tight in a vibrating environment, preventing test failure or inaccurate data due to accidental loosening.

[0025] The overall working process of the device is as follows: first, select a suitable clamping assembly 5 according to the property characteristics of the test piece to be tested, install the clamping assembly 5 on the fixed clamping block 2 and the movable clamping block 3, and place the test piece with the test piece between the fixed clamping block 2 and the movable clamping block 3 on which the clamping assembly 5 has been installed. The anti-slip texture of the clamping assembly 5 can enhance the friction between the test piece and the movable clamping block 3, preventing the test piece from slipping during the clamping process. Then, an axial clamping force is applied to the fixed clamping block 2 and the movable clamping block 3 through the fastening mechanism 4. Specifically, the locking bolt 7 is passed horizontally through the clamping block 8 and tightened so that the clamping block 8 stably clamps the fixed clamping block 2 and the movable clamping block 3, thereby firmly clamping the test piece in the middle and achieving reliable fixation of the test piece. The fixture body 1 is tightly connected to the incident rod or transmission rod of the Hopkinson rod. The sealing ring on the end face of the interface can prevent dust and other impurities from entering, while avoiding loosening of the connection due to vibration during the test, ensuring the stable transmission of stress waves between the rod and the fixture. In the Hopkinson bar test, when the impact end strikes the incident bar, a stress wave is generated. This stress wave propagates along the incident bar to the fixture body 1, and then is transferred through the fixture body 1 to the clamped specimen, subjecting the specimen to dynamic loads. Because the fixture's fastening mechanism 4 provides uniform clamping force and its overall structure is stable, reflections and interference from the stress wave during propagation are reduced, ensuring effective transmission of the stress wave to the specimen, thereby accurately testing the specimen's dynamic mechanical properties.

Claims

1. A Hopkinson tie rod clamp, characterized in that: The clamp comprises a clamp body (1), a fixed clamp block (2) axially extending from one end of the clamp body (1), a movable clamp block (3) arranged opposite to the fixed clamp block (2), and a fastening mechanism (4) for applying a clamping force to the fixed clamp block (2) and the movable clamp block (3).

2. The clamp according to claim 1, characterized in that: A detachable clamping assembly (5) is provided on the opposing surfaces of the fixed clamping block (2) and the movable clamping block (3), and a working surface of the clamping assembly (5) is provided with an anti-slip texture, wherein the anti-slip texture comprises at least one of corrugations, serrations or discrete protrusions.

3. The clamp according to claim 1, characterized in that: Positioning grooves are provided on the sides of the fixed clamping block (2) and the movable clamping block (3); the fastening mechanism (4) comprises a locking bolt (7) and a clamping block (8) matched with the positioning groove; the locking bolt (7) passes through the clamping block (8) transversely and applies a pre-tightening force.

4. The clamp according to claim 1, wherein: The other end of the clamp body (1) is provided with an axial connection port (6); the clamp body (1) and the fixed clamp block (2) are fixed by at least one of integral casting, welding or bolt connection.

5. The clamp according to claim 4, characterized in that: The axial connection port (6) is a threaded interface, and the threaded interface is a standardized interface, the diameter of which is consistent with the diameter of the Hopkinson rod, and a sealing ring is provided on the end face of the interface.

6. The clamp according to claim 3, characterized in that: The surface of the locking bolt (7) of the fastening mechanism (4) is provided with a wear-resistant coating, and the wear-resistant coating is titanium nitride or diamond-like carbon coating.

7. The clamp according to claim 3, characterized in that: Anti-slip pads are provided between the clamping block (8) and the positioning grooves of the fixed clamping block (2) and the movable clamping block (3).

8. The clamp according to claim 3, characterized in that: The threaded portion of the locking bolt (7) is provided with an anti-loosening structure.

9. The clamp according to claim 1, characterized in that: The fastening mechanism (4) is also provided with a quick release assembly.

10. The clamp according to claim 1, wherein: The outer end of the axial connection port (6) is provided with a rotary dust cover, and the dust cover is hinged to the clamp body (1) via a rotating shaft.

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