Test auxiliary device for testing stress cracking resistance and aging resistance of plastic

Abstract

The utility model provides a test auxiliary device for testing stress cracking resistance and aging resistance of plastics, which comprises a support, an upper supporting piece used for supporting the middle of a plastic test strip is arranged in the middle of the support, and lower pressing pieces used for pressing two ends of the plastic test strip are arranged on two sides of the support and spaced from the upper supporting piece. The supporting surface of the upper supporting piece is higher than the lower pressing surface of the lower pressing piece, so that the plastic test strip is limited between the upper supporting piece and the lower pressing piece in a bent shape. According to the utility model, the bracket is arranged, the upper supporting piece and the suspended lower pressing piece are arranged on the bracket, and the supporting surface of the upper supporting piece is higher than the lower pressing surface of the lower pressing piece, so that the middle part of the plastic test strip can be supported on the upper supporting piece, and the two ends of the plastic test strip are pressed by the lower pressing piece and cannot fall off; after the test auxiliary device and the plastic test strip on the test auxiliary device are placed in a use environment, stress cracking resistance and aging resistance tests of the plastic test strip are facilitated, the test time is shortened, the test period is shortened, and rapid judgment is facilitated; the device is simple in structure and convenient to operate, and can be widely applied to related tests such as stress cracking resistance tests and aging resistance tests of materials.

Description

Technical Field

[0001] This utility model relates to the field of plastics technology, and in particular to a test auxiliary device for testing plastics. Background Technology

[0002] With the increasing use of plastic materials in industrial product design, the performance requirements for these materials are becoming more stringent, and application tests such as stress cracking resistance and aging cracking resistance are becoming more widespread. Currently, laboratories typically place test strips horizontally or vertically in the testing environment, such as immersing them in chemical reagents or suspending them in a thermo-oxidative aging chamber. However, uneven placement or displacement / overlapping of the test strips during the test often leads to test failure. Furthermore, both horizontal and vertical placement of the test strips represent unstressed conditions, and the changes in appearance and cracking failure during stress cracking and aging tests are often very slow, resulting in long testing cycles and hindering rapid evaluation of material performance. Summary of the Invention

[0003] To address the aforementioned technical problems, this utility model proposes an auxiliary testing device for testing the stress cracking resistance and aging resistance of plastics. This device solves the problem that in the prior art, the plastic test strips are placed in a way that does not subject to stress, resulting in very slow failure changes and a long testing cycle.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0005] A testing auxiliary device for stress crack resistance and aging resistance of plastics includes a support frame. An upper support member is located in the middle of the support frame to support the middle of a plastic test strip. Lower pressure members, spaced apart from the upper support member, are located on both sides of the support frame to press down on both ends of the test strip. The supporting surface of the upper support member is higher than the pressing surface of the lower pressure members, so that the plastic test strip is curved and confined between the upper support member and the lower pressure members. This invention, by setting up a support frame with a suspended upper support member and a suspended lower pressure member, and with the supporting surface of the upper support member higher than the pressing surface of the lower pressure member, allows the middle of the plastic test strip to be supported on the upper support member, while the two ends are pressed down by the lower pressure members, preventing it from falling off. Simultaneously, the plastic test strip is curved. When this testing auxiliary device and the plastic test strip on it are placed in the usage environment, it facilitates stress crack resistance and aging resistance testing of the plastic test strip, shortens the testing time and cycle, and facilitates rapid evaluation.

[0006] Furthermore, in order to minimize interference between the upper support and the plastic test strip at the contact surface, the upper support is a first cylindrical rod with both ends connected to the bracket, so that the contact surface between the upper support and the bent plastic test strip is also curved, thereby reducing stress concentration.

[0007] Furthermore, in order to better limit the plastic test strip and prevent it from falling off the test auxiliary device, the lower side of the pressure member is provided with a limiting groove that cooperates with the plastic test strip to prevent the plastic test strip from sliding out under the pressure member after it deviates.

[0008] Furthermore, in order to minimize interference between the contact surface between the pressure member and the plastic test strip, the pressure member includes a second cylindrical rod, the two ends of which are connected to a bracket.

[0009] Furthermore, in order to better prevent the plastic test strip from falling off the test aid, the limiting member also includes a limiting member disposed on the lower side of the second cylindrical rod to form an inverted U-shaped limiting groove.

[0010] Furthermore, the limiting member includes a plurality of vertical rods spaced apart on the lower side of the second cylindrical rod, and the limiting groove is formed between adjacent vertical rods.

[0011] Furthermore, in order to facilitate obtaining more comprehensive test data on stress cracking resistance and aging resistance, the upper support is slidably mounted on the bracket to adjust the curvature of the plastic test strip.

[0012] Furthermore, in order to facilitate the adjustment of the height of the upper support member, the bracket is provided with vertical grooves at both ends, and the upper support member is provided with horizontal screws at both ends for passing through the grooves and fitting with the grooves with a clearance. One end of the screws that passes through the grooves is connected to a fastening nut for fastening the position of the screws.

[0013] Furthermore, in order to facilitate the adjustment of the height of the upper support, the bracket is provided with vertical grooves at both ends, and the upper support is provided with internal threaded holes at both ends. A butterfly-shaped fastening bolt is threaded through the groove, and the screw end of the butterfly-shaped fastening bolt passes through the groove and is threaded into the internal threaded hole.

[0014] Furthermore, in order to meet the purpose of the experiment while simplifying the structure of the device, the support includes at least two parallel and spaced-apart portal frames, a connecting rod connecting the adjacent portal frames, and a vertical plate located in the middle of the top of the portal frames; the lower pressure members are respectively connected to the two ends of the top of the adjacent portal frames; a vertical plate is provided in the middle of the top of the portal frames, and the two ends of the upper support member are slidably connected to the vertical plate.

[0015] The beneficial effects of this utility model are:

[0016] 1. This utility model sets up a bracket with a suspended upper support and a suspended lower pressure member on the bracket. The support surface of the upper support is higher than the lower pressure surface of the lower pressure member, so that the middle part of the plastic test strip can be supported on the upper support and the two ends are pressed down by the lower pressure member to prevent it from falling off. At the same time, the plastic test strip is curved, which facilitates the stress crack resistance and aging resistance test of the plastic test strip, and shortens the test time and test cycle, making it easier to judge quickly.

[0017] 2. The structure of this utility model is simple, avoiding destructive fixing methods such as drilling and gluing. This utility model relies on the plastic deformation of the plastic itself to effectively fix the test strips, ensuring that multiple test strips do not shift or overlap during the test, thus ensuring the validity of the test.

[0018] 3. The present invention facilitates the adjustment of the curvature of the plastic test strip by sliding the upper support member up and down, thereby adjusting the stress on the plastic test strip and making it easier to obtain more comprehensive test data on stress cracking resistance and aging resistance.

[0019] 4. This utility model has a simple structure and is easy to operate. It can be widely used in materials stress cracking resistance test, aging resistance test and other related tests. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0022] Figure 2 This is a side view of the structure of this utility model;

[0023] Figure 3 This is a schematic diagram illustrating the use of this utility model.

[0024] In the diagram: 1. Connecting rod, 2. Portal frame, 3. Lower pressure piece, 31. Second cylindrical rod, 32. Vertical rod, 4. Upper support piece, 5. Vertical plate, 6. Butterfly-shaped fastening bolt, 7. Plastic test strip. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figure 1 and Figure 3 As shown in Embodiment 1 of this utility model, a test auxiliary device for testing the stress cracking resistance and aging resistance of plastics includes a support frame. An upper support member 4 is provided in the middle of the support frame to support the middle of a plastic test strip 7. Lower pressure members 3, spaced apart from the upper support member 4, are provided on both sides of the support frame to press down the two ends of the plastic test strip 7. In this embodiment, the upper support member 4 and the lower pressure members 3 are suspended on the support frame, meaning that the two ends of the upper support member 4 and the lower pressure members 3 are respectively connected to the support frame, and the lower sides of the upper support member 4 and the lower pressure members 3 are open spaces. The supporting surface of the upper support member 4, which supports the plastic test strip 7, is higher than the pressing surface of the lower pressure member 3, which presses down on the plastic test strip 7, so that the plastic test strip 7 is curved and confined between the upper support member 4 and the lower pressure member 3. By placing this test auxiliary device and the plastic test strip on it in the usage environment, the stress cracking resistance and aging resistance tests of the plastic test strip are facilitated.

[0027] In this embodiment, the upper support member 4 is a first cylindrical rod, with both ends of the first cylindrical rod connected to the bracket. The lower pressure member 3 includes a second cylindrical rod 31, with both ends of the second cylindrical rod 31 connected to the bracket. The first cylindrical rod and the second cylindrical rod 31 are parallel and spaced apart. Furthermore, one second cylindrical rod 31 is provided on each side of the bracket, and the two second cylindrical rods 31 are symmetrically located on both sides of the first cylindrical rod.

[0028] Example 2 differs from Example 1 in that, to prevent the plastic test strip 7 from sliding out of the lower pressure member 3 due to the reaction force caused by its own bending, the lower side of the lower pressure member 3 is provided with a limiting groove that cooperates with the plastic test strip 7. The limiting groove is concave upward, and the plastic test strip 7 abuts against the top of the limiting groove to prevent it from sliding out of the limiting groove.

[0029] In this embodiment, the pressing member 3 includes a limiting member disposed on the lower side of the second cylindrical rod 31, that is, a limiting member is disposed on the lower side of the second cylindrical rod 31 to form the limiting groove. Furthermore, in this embodiment, the limiting groove is an inverted U-shape.

[0030] Specifically, the limiting member includes a plurality of vertical rods 32 spaced apart on the lower side of the second cylindrical rod body 31, and the inverted U-shaped limiting groove is formed between adjacent vertical rods 32.

[0031] Example 3 differs from Example 2 in that the upper support 4 is slidably mounted on the bracket to adjust the curvature of the plastic test strip 7.

[0032] In this embodiment, the bracket has vertical grooves at both ends, and the upper support member 4, i.e., the first cylindrical rod, has internal threaded holes at both ends. A butterfly-shaped fastening bolt 6 passes through the groove. The screw end of the butterfly-shaped fastening bolt 6 passes through the groove and is threaded into the internal threaded hole. The position of the upper support member 4 is fixed by tightening the butterfly-shaped fastening bolt 6 and abutting against the bracket.

[0033] In another embodiment, the bracket has vertical grooves at both ends, and the upper support member 4, i.e., the first cylindrical rod, has horizontal screws at both ends for passing through the grooves. The horizontal screws are fitted with the grooves with a clearance, allowing the horizontal screws to slide up and down within the vertical grooves. A fastening nut is connected to one end of the screw that extends out of the groove, used by the upper support member 4 to slide and adjust the position of the screw within the groove. By tightening the fastening nut, the fastening nut presses against both sides of the groove, thereby fixing the position of the screw.

[0034] In addition, a scale is provided on one side of the slide to facilitate adjustment of the height of the upper support.

[0035] Example 4 differs from Example 3 in that, as Figure 1 and Figure 2 As shown, the support includes two portal frames, several connecting rods, and two vertical plates 5. The two portal frames are parallel and spaced apart. The connecting rods connect between the two portal frames and between the two legs of each portal frame. The connection points of the connecting rods with the two portal frames are located at the middle of the portal frame legs. The pressing members 3 are respectively connected to the two ends of the top of adjacent portal frames, that is, both pressing members 3 are connected to the top of the two portal frames, and the connection points of the pressing members 3 with each portal frame are located at both ends of that portal frame. The two vertical plates 5 are respectively located at the middle position of the top of the two portal frames, and the sliding groove is provided on the vertical plates 5. The two ends of the upper support member 4 are slidably connected to the vertical plates 5.

[0036] Example 5 differs from Example 3 in that the bracket, upper support 4, lower pressure 3, butterfly-shaped fastening bolt 6 or screw and nut are all made of stainless steel.

[0037] Preferably, the two second cylindrical rods and one first cylindrical rod are all made of cylindrical stainless steel with polished surfaces, which facilitates the handling of plastic test strips and prevents scratches from forming on the surface of the plastic test strips, so as not to affect the judgment of test results.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some or all of the technical features thereof, within the spirit and principles of the present invention, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An experimental aid for testing the stress cracking resistance and the aging resistance of plastics, characterized in that The bracket comprises an upper support (4) for supporting the middle part of the plastic test strip (7), and two lower pressing members (3) for pressing the two ends of the plastic test strip (7) at intervals with the upper support (4), and the support surface of the upper support (4) is higher than the pressing surface of the lower pressing member (3), so that the plastic test strip (7) is limited between the upper support (4) and the lower pressing member (3) in a curved shape.

2. The test auxiliary device for testing plastic stress cracking resistance and aging resistance according to claim 1, characterized in that, The upper support (4) is a first cylindrical rod body, and the two ends of the first cylindrical rod body are connected with the bracket.

3. The test auxiliary device for testing stress cracking resistance and aging resistance of plastic according to claim 1 or 2, characterized in that, The lower side of the lower pressing member (3) is provided with a limiting groove matched with the plastic test strip (7) for preventing the plastic test strip (7) from sliding out from below the lower pressing member (3) after being deflected.

4. The test auxiliary device for testing plastic stress cracking resistance and aging resistance according to claim 3, characterized in that, The lower pressing member (3) comprises a second cylindrical rod body (31), and the two ends of the second cylindrical rod body (31) are connected with the bracket.

5. The test auxiliary device for testing plastic stress cracking resistance and aging resistance according to claim 4, characterized in that, The lower pressing member (3) further comprises a limiting member arranged on the lower side of the second cylindrical rod body (31) for forming the limiting groove in an inverted U shape.

6. The test auxiliary device for testing plastic stress cracking resistance and aging resistance according to claim 5, characterized in that, The limiting member comprises a plurality of vertical rods (32) arranged at intervals on the lower side of the second cylindrical rod body (31), and the limiting groove is formed between adjacent vertical rods (32).

7. The test auxiliary device for testing plastic stress cracking resistance and aging resistance according to any one of claims 1, 2, 4 to 6, characterized in that, The upper support (4) is arranged on the bracket in a sliding manner up and down for adjusting the curvature of the plastic test strip (7).

8. The test auxiliary device for testing plastic stress cracking resistance and aging resistance according to claim 7, characterized in that, The two ends of the bracket are provided with vertical sliding grooves, and the two ends of the upper support (4) are provided with horizontal threaded rods for penetrating through the sliding grooves and being matched with the sliding grooves in gaps, and one end of the threaded rod penetrating out of the sliding groove is connected with a fastening nut.

9. The test auxiliary device for testing plastic resistance to stress cracking and aging resistance according to claim 7, characterized in that, The two ends of the bracket are provided with vertical sliding grooves, and the two ends of the upper support (4) are provided with internal threaded holes, and a butterfly-shaped fastening bolt (6) is arranged on the sliding groove, and the threaded rod end of the butterfly-shaped fastening bolt (6) is threadedly connected into the internal threaded hole after penetrating through the sliding groove.

10. The test auxiliary device for testing plastic resistance to stress cracking and aging resistance according to any one of claims 1, 2, 4 to 6, 8 and 9, characterized in that, The bracket comprises at least two parallel and spaced-apart door-shaped frames (2), a connecting rod (1) connected between adjacent door-shaped frames (2), and a vertical plate (5) arranged at the middle of the top of the door-shaped frame (2); the lower pressing member (3) is connected at the two ends of the top of the adjacent door-shaped frame (2); and the two ends of the upper support (4) are slidingly connected on the vertical plate (5).

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