Quick-replaceable tensile test clamp and insert combination

Abstract

The utility model discloses a tensile test fixture and insert combination capable of being quickly replaced. The tensile test fixture and insert combination is provided with a pair of fixture bodies which are arranged in a temperature control environment box and are connected with tensile power. The reloading clamp is provided with inserts which are matched with clamp bodies and can be assembled in a separable mode, the front face of each clamp body is provided with a trapezoid groove with the top and the bottom being hollow, the bottom edge provided with the trapezoid groove is adjacent to the other clamp body, and the top edge of the trapezoid groove is far away from the other clamp body and is longer than the bottom edge. The front face of the clamp body is provided with a movable blocking piece close to the inclined waist wall of the trapezoid-shaped groove. The insert is a pair of rigid blocks which wrap and clamp the sample strip and are assembled and fixed, the appearance of the assembled insert is matched and compatible in the trapezoid-shaped groove, and the insert is limited by the movable blocking piece to be prevented from falling off or a reloading channel is reserved. According to the reloading clamp, the operation separation of sample reloading and clamp resetting in time and space is realized, the clamp distance does not need to be frequently adjusted, the door opening duration and the temperature variation amplitude of an environment box are favorably reduced, and the test efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to a fixture structure optimization, in particular to a replacement fixture and insert combination suitable for quickly replacing splines and efficiently performing tensile tests in low-temperature and high-temperature environments. Background Art

[0002] The tensile test is the fastest, most informative, most common and most basic test among all the tests for examining the mechanical properties of materials.

[0003] During low- and high-temperature testing, the tensile process is performed in an environmental chamber. Therefore, the fixtures and other components used in the tensile test are located within the chamber, and the test process must be maintained at a relatively stable, preset constant temperature. To minimize space usage and maximize temperature control efficiency, environmental chambers are typically designed with a relatively small volume. This means that specimen changes must also be performed within the chamber, which is confined and inconvenient. This, in turn, results in a time-consuming specimen change, prolonged chamber maintenance, and subsequent temperature control, requiring increased time and energy. This significantly impacts test efficiency and cost.

[0004] According to the traditional test process, the specimen is placed in an environmental chamber and cooled or heated together with the fixtures. After the temperature drops to or rises to the set temperature, the environmental chamber is opened, the position is adjusted to clamp the specimen on the fixture, and the distance between the fixtures is measured; then the environmental chamber door is closed, and after the temperature returns to the set temperature, the fixture is pulled to perform a tensile test; after the test is completed, the chamber door is opened again to remove the stretched specimen, and a new specimen is replaced, and the distance between the fixtures is remeasured. The environmental chamber door is closed, and after the temperature returns to the set temperature, a tensile test is performed on the second specimen, and this is repeated until the test is completed.

[0005] As can be seen, the traditional spline clamping method requires relatively long operation times in low or high temperatures and confined spaces, and has significant disadvantages in terms of field of view and fixture distance measurement. Consequently, the distance between fixtures cannot be fixed, making consistency difficult to ensure. This, to some extent, hinders the strict implementation of the plastics tensile standard (GB / T 1040 stipulates the distance between spline fixtures for calculating tensile nominal strain). Summary of the Invention

[0006] The purpose of the utility model is to provide a quick-change tensile test fixture and insert combination, which solves the problem of quick replacement of sample strips and reduces energy loss for maintaining temperature in an environmental box.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a quick-change tensile test fixture and insert combination, comprising a pair of fixture bodies that are installed in a temperature-controlled environment box and connected to a tensile power, the changing fixture is provided with an insert that is matched with the fixture body and can be detachably assembled, the front of each of the fixture bodies is provided with a trapezoidal groove with a top and bottom that is empty, the bottom side of the trapezoidal groove is adjacent to the other fixture body, the top side of the trapezoidal groove is away from the other fixture body, and the top side is longer than the bottom side, and a movable baffle is provided on the front of the fixture body at the inclined waist wall adjacent to the trapezoidal groove; the insert is a pair of rigid blocks that clamp the spline and are assembled and fixed, each insert is provided with a number of laterally penetrating screw holes, all of which are connected with fastening bolts to fix the spline and a pair of inserts, the outer shape of the assembled insert is adapted to be compatible with the trapezoidal groove, and is limited by the movable baffle to prevent the insert from falling off or giving up the changing channel.

[0008] Furthermore, a fixed shaft sleeve rod is provided in the temperature-controlled environment box, and the clamp body is docked with the fixed shaft sleeve rod on the same side and moves integrally, and the pair of clamp bodies are controlled to reset themselves to the origin.

[0009] Furthermore, a baffle groove is formed on the front side of the clamp body next to the trapezoidal groove, and one end of the elongated movable baffle is attached to the baffle groove by a positioning bolt, and the movable baffle is flipped and cut into the outward projection space of the trapezoidal groove, or reset to be completely received in the baffle groove.

[0010] Furthermore, the clamp body is provided with a pre-tightening assembly consisting of a pre-tightening push head, an adjusting rod and a spring at the top edge of the trapezoidal groove, wherein the pre-tightening push head is integrally formed with a rod body portion and a disc-shaped head portion, the rod body portion is guided and connected to the longitudinal groove formed by the clamp body and a rack is formed on the front side, the spring is sleeved on the rod body portion and its two ends are against the disc-shaped head portion and the inner wall of the top edge of the trapezoidal groove, the adjusting rod is pivotally positioned in the clamp body, and the adjusting rod extends outward to form an operating portion and is formed inward to form a fan-shaped gear meshing with the rack; the insert is formed toward the top edge as an open ring facing the disc-shaped head and clamped and pulled by force.

[0011] Furthermore, the opposite surface of the insert used to clamp the spline is processed into a damping surface, which can be a chamfered surface, a frosted surface or other surface types, in order to increase friction and prevent relative displacement between the insert and the tensile specimen (i.e., the spline).

[0012] Furthermore, the clamp body is provided with a limiting groove in the trapezoidal groove, and the insert is provided with a limiting protrusion on the back side facing the trapezoidal groove. When the insert and the clamp body are assembled, the limiting protrusion is plugged and compatible in the limiting groove.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the spline replacement and fixture resetting operations are separated in time and space through the insert, and the automatic resetting of the fixture solidifies the fixture spacing, without the need for frequent adjustment; and the splines and inserts can be replaced outside the environmental chamber, eliminating space limitations and facilitating the clamping position of the splines, with reliable spacing and clamping force at both ends; the replacement fixture is conducive to reducing the door opening time of the environmental chamber and the temperature variation range, thereby greatly improving test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the assembly structure of the fixture body and inserts on the top side of the replacement fixture of the utility model.

[0015] Figure 2 yes Figure 1 Schematic diagram of the back structure.

[0016] Figure 3 It is a schematic diagram of the assembly structure of the insert clamping spline in the replacement fixture of the utility model. DETAILED DESCRIPTION

[0017] The specific implementation methods of the present invention will be further described below in conjunction with the accompanying drawings to make the technical solution easier to understand and grasp, thereby making a clearer definition of the protection scope of the present invention.

[0018] The designers of this utility model have optimized the structure of existing tensile testing equipment in low-temperature environments, especially the many shortcomings of the clamps, and innovatively proposed a clamp and insert combination to solve the operability, energy consumption and efficiency problems of the test equipment when changing specimens and conducting continuous tests in a narrow space.

[0019] like Figure 1 As shown, the present invention is a quick-change tensile test fixture and insert combination, comprising a pair of fixture bodies 1 installed in a temperature-controlled environmental chamber (finished equipment, not shown) and connected to a tensile power source. As a major aspect of the technical improvement, the replacement fixture is equipped with an insert 2 that is a one-to-one match with the fixture body 1 and can be assembled separately. Since the two sets of fixture bodies and inserts installed at the opposite ends of the spline are identical, only one set will be illustrated and described in detail below. Figure 1As shown, the front of the clamp body 1 is provided with a trapezoidal groove 11 with a hollow top and bottom. The bottom edge 112 of the groove is adjacent to the other clamp body, while the top edge 111 of the groove is further away from the other clamp body, with the top edge being longer than the bottom edge. The front of the clamp body 1 is provided with movable retaining plates 3a and 3b, respectively, adjacent to the inclined waist wall 113 of the groove 11. The inserts 2 are a pair of rigid blocks that clamp the spline 7 and secure it in place. Each insert 2 has several lateral screw holes 21 extending through it, all of which are threaded with fastening bolts 62 to secure the spline 7 and the pair of inserts. In the illustrated embodiment, each insert has four screw holes and four fastening bolts, evenly distributed on either side of the clamped spline. The clamping range can be adjusted appropriately based on the thickness of the spline. The assembled inserts fit snugly within the trapezoidal groove 11, and are held in place by movable retaining plates to prevent them from falling out or obstructing the reloading channel.

[0020] As can be understood, the fixture body provides a downward-converging opening for the insert (and the enclosed spline), while a movable retaining plate provides stability and operational convenience for rapid insert replacement. As the tensile test force is increased (the distance between the two fixture bodies increases), the inserts, secured in the trapezoidal grooves, move integrally with the fixture body, gradually increasing the distance between the two sets of inserts. This allows the spline to be stretched under the preset low-temperature environment and under double-end force. This process effectively inherits the clamping efficiency of traditional similar tests. Its key advantage is that spline replacement is no longer confined to the confined space of the temperature-controlled environmental chamber; instead, it can be assembled off-chamber along with the inserts. This significantly improves operational convenience, while the pre-installed positions of the spline and inserts are precisely measured and adjusted. With redundant inserts, batches of spline specimens can be tested continuously without the frequent temperature fluctuations in the temperature-controlled environmental chamber, optimizing both efficiency and energy consumption.

[0021] Looking more closely at the structure of existing equipment, the temperature-controlled environmental chamber is equipped with a fixed-axis sleeve 5. The fixture body 1, via its integrally formed central axis boss 14, docks with the fixed-axis sleeve 5 on the same side. The two are coaxially connected and interconnected via through-pins or screws, enabling them to move with one another. The desired optimization involves adjusting the temperature-controlled environmental chamber and related equipment to adjust the telescopic travel of the fixed-axis sleeve so that the pair of fixture bodies can be controlled to return to their original position (i.e., the original clamping length that meets the spline tensile test standard).

[0022] The front of the clamp body 1 is formed with a baffle groove 15 next to the trapezoidal groove. One end of the long movable baffle is attached to the baffle groove 15 by a positioning bolt 61, and the movable baffle is flipped with the positioning bolt as the axis to cut into the outward projection space of the trapezoidal groove (for temporarily blocking the insert assembly), or reset to be completely accommodated in the baffle groove (suitable for convenient replacement of inserts).

[0023] The clamp body 1 is provided with a preload assembly at the top edge of the trapezoidal groove, consisting of a preload pusher 41, an adjustment rod 42, and a spring 43. The preload pusher 41 is integrally formed with a rod body 412 and a disc-shaped head 411. The rod body 412 guides through the longitudinal groove 13 formed in the clamp body and has a rack 4121 formed on its front. The spring 43 is sleeved onto the rod body 412, with its ends abutting against the disc-shaped head 411 and the inner wall of the top edge of the trapezoidal groove. The adjustment rod 42 is pivotally positioned within the clamp body 1, extending outward to form an operating portion and inward to form a fan-shaped gear (not shown) that meshes with the rack. Simultaneously, the insert is formed toward the top edge with an open collar 22 that faces the disc-shaped head 411 and receives force. Thus, once the insert and spline assembly are installed in the trapezoidal groove, initial compression is achieved through the rack drive of the preload assembly.

[0024] On the other hand, the opposing surface 23 of the insert 2, which is used to hold the spline, is treated as a damping surface. This damping surface can be configured as a chamfered surface, a frosted surface, or a similar surface shape to increase friction and prevent abnormal displacement and sliding between the insert and the spline during the tensile test, which could affect the test results.

[0025] In addition, Figure 2 and Figure 3 As shown, the fixture body 1 is provided with a retaining groove 16 within the trapezoidal groove, while the insert 2 is provided with a retaining protrusion 4 on the back side of the trapezoidal groove. When the insert and fixture body are assembled, the retaining protrusion is plugged into and compatible with the retaining groove to achieve initial positioning. In this embodiment, the retaining protrusion conforms to the inverted figure-eight shape of the retaining groove, with targeted positioning and combined spacing to accommodate the varying thicknesses of the splines. Furthermore, in this case, additional spline fixings, such as tightening bolts, can be reduced. The combined action of pre-compression and tensioning forces allows the insert to be firmly clamped against the center spline.

[0026] From the above detailed description of the embodiment of the quick-change fixture and insert combination used in the tensile test of the utility model, it can be seen that it has substantial characteristics and progress: the insert realizes the separation of spline replacement and fixture reset in time and space, and the automatic reset of the fixture solidifies the fixture spacing, without the need for frequent adjustment; and the splines and inserts can be replaced outside the environmental chamber, eliminating space limitations and facilitating the reliable clamping position, spacing between the two ends and clamping force of the splines; the replacement fixture is conducive to reducing the opening time of the environmental chamber and the temperature change range, speeding up the speed at which the temperature returns to the set temperature, thereby greatly improving the test efficiency.

[0027] In addition to the above embodiments, the present invention may also have other implementation methods. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A quick-change tensile test fixture and insert assembly comprising a pair of fixture bodies housed in a temperature-controlled environmental chamber and connected to a tensile power source, characterized in that: The changing fixture is provided with an insert that is matched with the fixture body and can be separably assembled. The front of each fixture body is provided with a trapezoidal groove with empty top and bottom. The bottom edge of the trapezoidal groove is adjacent to the other fixture body, and the top edge of the trapezoidal groove is away from the other fixture body, and the top edge is longer than the bottom edge. A movable baffle is provided at the inclined waist wall adjacent to the trapezoidal groove on the front of the fixture body; the insert is a pair of rigid blocks that are assembled and fixed by clamping splines, and each insert is provided with a number of laterally penetrating screw holes, all of which are connected with fastening bolts to fix the splines and a pair of inserts. The shape of the assembled insert is adapted to be compatible with the trapezoidal groove, and is limited by the movable baffle to prevent the insert from falling off or giving up the changing channel.

2. A quick-change tensile test fixture and insert assembly according to claim 1, characterized in that: A fixed shaft sleeve rod is provided in the temperature-controlled environment box, and the clamp body is docked with the fixed shaft sleeve rod on the same side and moves integrally, and a pair of the clamp bodies are controlled to reset themselves to the origin.

3. A quick-change tensile test fixture and insert assembly according to claim 1, characterized in that: A baffle groove is formed on the front side of the clamp body next to the trapezoidal groove, and one end of the elongated movable baffle is attached to the baffle groove by a positioning bolt, and the movable baffle is flipped and cuts into the outward projection space of the trapezoidal groove, or is reset and completely received in the baffle groove.

4. The quick-change tensile test fixture and insert assembly according to claim 1, characterized in that: The clamp body is provided with a pre-tightening assembly consisting of a pre-tightening push head, an adjusting rod and a spring at the top edge of the trapezoidal groove, wherein the pre-tightening push head is integrally formed with a rod body and a disc-shaped head, the rod body is guided and connected to the longitudinal groove formed by the clamp body and a rack is formed on the front, the spring is sleeved on the rod body and its two ends rest against the disc-shaped head and the inner wall of the top edge of the trapezoidal groove, the adjusting rod is pivotally positioned in the clamp body, and the adjusting rod extends outward to form an operating part and is formed inward to form a fan-shaped gear meshing with the rack; the insert is formed toward the top edge as an open ring facing the disc-shaped head and subjected to force.

5. The quick-change tensile test fixture and insert assembly according to claim 1, characterized in that: The opposite surfaces of the inserts used for enclosing the splines are processed into damping-enhanced surfaces.

6. The quick-change tensile test fixture and insert assembly according to claim 1, characterized in that: The clamp body is provided with a limiting groove in the trapezoidal groove, and the insert is provided with a limiting protrusion on the back side facing the trapezoidal groove. When the insert and the clamp body are assembled, the limiting protrusion is plugged and compatible in the limiting groove.

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