Loading clamp

Abstract

The utility model discloses a loading clamp which comprises an upper clamp, a lower clamp, a sliding block and a first fixing piece, the lower clamp is detachably connected with the upper clamp, the sliding block is connected to the upper clamp in a sliding mode, one end of the sliding block is used for being connected with a motor, the other end of the sliding block is used for clamping one end of a solid propellant test piece, and the lower clamp is used for clamping the other end of the solid propellant test piece; the first fixing piece is used for fixing the sliding block and the upper clamp. Compared with the prior art, the sliding block and the upper clamp are slidably connected, before the aging test, the sliding block moves relative to the upper clamp to stretch the solid propellant test piece, the first fixing piece prevents the solid propellant test piece from rebounding, and after the aging test, the upper clamp and the lower clamp are separated; the motor pulls the sliding block to enable the sliding block and the upper clamp to move upwards at the same time, the tensile test is continued, the clamps do not need to be assembled again, the first fixing piece is always kept in a fixed state in the whole process, the test process is simplified, and the accuracy of a test result is improved.

Description

Technical Field

[0001] The embodiment of the utility model relates to the technical field of material mechanics in the aerospace field, and in particular to a loading fixture. Background Art

[0002] There are many problems to be solved and verified in the production, service and storage of solid rocket engine propellants. Since the thermal expansion coefficient of the metal shell is lower than that of the propellant, residual thermal stress / strain will be generated during the solidification and cooling process. The grain will be constrained by the shell in the actual process, which makes the grain in a stress or strain state for a long time. Therefore, the conclusions drawn are different from those of the propellant billet and the predicted life of the engine is inaccurate. Therefore, it is more meaningful to study the storage aging characteristics of the propellant under the action of thermal-mechanical coupling.

[0003] In order to obtain the mechanical properties of propellant under the coupled-force aging, many researchers have designed corresponding fixtures to make the propellant reach the purpose of aging at a given strain rate in the initial state. However, after aging, the loading test needs to be continued. The current loading fixture cannot complete the aging test and the subsequent loading test at one time. In the subsequent loading test, the fixture needs to be reassembled, which is troublesome and cumbersome. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a loading fixture which can continuously perform aging and loading tests.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0006] A loading fixture comprises an upper fixture, a lower fixture, a slider and a first fixing member, wherein the lower fixture is detachably connected to the upper fixture, the slider is slidably connected to the upper fixture, one end of the slider is used to connect to a motor, and the other end is used to clamp one end of the solid propellant specimen, and the lower fixture is used to clamp the other end of the solid propellant specimen; the first fixing member is respectively connected to the slider and the upper fixture to fix the slider and the upper fixture.

[0007] As one embodiment, the loading fixture includes a second fixing member, the upper fixture is provided with a first through hole on two opposite sides, the lower fixture is provided with a second through hole on two opposite sides, and the second fixing member passes through the first through hole and the second through hole in sequence to fix the upper fixture and the lower fixture.

[0008] As one embodiment, the inner surface of the first through hole is smooth, the inner surface of the second through hole is provided with threads, the second fixing piece passes through the first through hole and is threadedly connected to the second through hole, and the aperture of the first through hole is larger than the aperture of the second through hole.

[0009] As one embodiment, the upper clamp includes a first main body and a first step portion, and the first step portion is connected to the opposite sides of the first main body; the lower clamp includes a second main body and a second step portion, and the second step portion is connected to the opposite sides of the second main body; the first through hole is opened in the first step portion, and the second through hole is opened in the second step portion; wherein the first step portion is used to abut against the lower clamp, and the second step portion is used to abut against the upper clamp.

[0010] As one embodiment, the first step portion is connected to the outer side surface of the first main body portion, and the first step portion is used to abut against the outer side of the lower clamp; the second step portion is connected to the inner side surface of the second main body portion, and the second step portion is used to abut against the inner side of the first main body portion.

[0011] As one embodiment, sliding grooves are provided on opposite sides of one of the upper clamp and the sliding block, and the other one of the upper clamp and the sliding block is slidably connected to the sliding grooves.

[0012] As one embodiment, the slider is provided with a fixing groove along its length direction, the upper clamp is provided with a fixing hole, the fixing groove is connected to the fixing hole, and the first fixing piece is passed through the fixing groove and the fixing hole and is threadedly connected to fix the slider and the upper clamp.

[0013] As one embodiment, the sliding block is provided with a plurality of fixing grooves along its width direction, and the upper clamp is provided with a plurality of fixing holes along its width direction, and the plurality of fixing grooves correspond to the plurality of fixing holes one by one.

[0014] As one implementation manner, the upper clamp is provided with a plurality of fixing holes along the extending direction of the fixing groove.

[0015] As one of the embodiments, the slider includes a third main body and a first limiting portion, the first limiting portions are provided on opposite sides of the third main body, the third main body and the first limiting portion together form a first clamping groove, the first clamping groove is used to clamp one end of the solid propellant specimen, and the first limiting portion is used to form a smooth curved surface on one side abutting against the solid propellant specimen; the lower clamp includes a second main body and a second limiting portion, the second main body is provided on opposite sides of the second limiting portion, the second main body and the second limiting portion together form a second clamping groove, the second clamping groove is used to clamp the other end of the solid propellant specimen, and the second limiting portion is used to form a smooth curved surface on one side abutting against the solid propellant specimen.

[0016] The beneficial effect of the utility model is that: the embodiment of the present application provides a loading fixture, including an upper fixture, a lower fixture, a slider and a first fixing member, the lower fixture is detachably connected to the upper fixture, the slider is slidably connected to the upper fixture, one end of the slider is used to connect the motor, and the other end is used to clamp one end of the solid propellant specimen, and the lower fixture is used to clamp the other end of the solid propellant specimen; the first fixing member is respectively connected to the slider and the upper fixture to fix the slider and the upper fixture. Compared with the prior art, the present application sets a slider, the slider is slidably connected to the upper fixture, before the aging test, the solid propellant specimen is stretched by moving the slider relative to the upper fixture, the first fixing member fixes the slider and the upper fixture to prevent the solid propellant specimen from rebounding, after the aging test, the upper fixture and the lower fixture are separated, the motor pulls the slider to make the slider and the upper fixture move upward at the same time, and the tensile test is continued, and the fixture does not need to be assembled again, and the first fixing member is always in a fixed state during the whole process, so that the solid propellant specimen will not rebound in the subsequent stretching process, simplifying the test process and improving the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a loading fixture according to an embodiment of the utility model is shown;

[0018] Figure 2 A schematic diagram of an exploded view of parts of a loading fixture according to an embodiment of the utility model is shown;

[0019] Figure 3 A schematic structural diagram of a slider according to an embodiment of the utility model is shown;

[0020] Figure 4 A schematic structural diagram of a lower clamp according to an embodiment of the utility model is shown.

[0021] Reference numerals:

[0022] 100, loading fixture; X, length direction; Y, width direction; 1, upper fixture; 11, first through hole; 12, slide groove; 13, fixing hole; 14, first main body; 15, first step portion;

[0023] 2. lower clamp; 21. second through hole; 22. second main body; 23. second limiting portion; 24. second clamping groove; 25. second step portion;

[0024] 3. Slider; 31. Fixing groove; 32. Third main body; 33. First limiting part; 34. First clamping groove; 4. Solid propellant specimen. DETAILED DESCRIPTION

[0025] In the present invention, the terms "disposed", "provided with", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "radial", "circumferential", etc. are based on the orientation or position relationship shown in the drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in this utility model can be understood according to specific circumstances.

[0029] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0030] See also Figure 1 The embodiment of the present application provides a loading fixture 100, including an upper fixture 1, a lower fixture 2, a slider 3 and a first fixing member (not shown in the figure), the lower fixture 2 is detachably connected to the upper fixture 1, the slider 3 is slidably connected to the upper fixture 1, one end of the slider 3 is used to connect to the motor, and the other end is used to clamp one end of the solid propellant specimen 4, and the lower fixture 2 is used to clamp the other end of the solid propellant specimen 4; the first fixing member is respectively connected to the slider 3 and the upper fixture 1 to fix the slider 3 and the upper fixture 1.

[0031] It should be noted that the solid propellant specimen 4 may be a dumbbell-shaped solid propellant specimen 4 .

[0032] In actual application, the upper clamp 1 and the lower clamp 2 are first connected together, the slider 3 is slidably connected to the upper clamp 1, and the first fixing part is removed so that the slider 3 can slide relative to the upper clamp 1. One end of the slider is used to connect to the output end of the motor, and the other end is used to clamp the solid propellant specimen 4. One end of the solid propellant specimen 4 is clamped by the slider 3, and the other end is clamped by the lower clamp 2.

[0033] After the solid propellant specimen 4 is installed, the motor is started, and the motor drives the slider 3 to move upward relative to the upper clamp 1 to stretch the solid propellant specimen 4 until it is stretched to a first preset state, and the first fixing member is connected to the slider 3 and the upper clamp 1 to fix the slider 3 and the upper clamp 1 together to prevent the solid propellant specimen 4 from rebounding, and a stress test is performed on the solid propellant specimen 4; then the loading fixture 100 is placed in an aging box for a preset aging time, the loading fixture 100 is taken out and cooled to room temperature, and a tensile test is performed again, the upper clamp 1 and the lower clamp 2 are separated, and the first fixing member remains in a fixed state, and the motor is started to drive the slider 3 and the upper clamp 1 to move upward relative to the lower clamp 2 to stretch the solid propellant specimen 4 to a second preset state, and a stress test is performed on the solid propellant specimen 4.

[0034] Compared with the prior art, the present application sets a slider 3, which is slidably connected to the upper clamp 1. Before the aging test, the solid propellant specimen 4 is stretched by moving the slider 3 relative to the upper clamp 1. The first fixing member fixes the slider 3 and the upper clamp 1 to prevent the solid propellant specimen 4 from rebounding. After the aging test, the upper clamp 1 and the lower clamp 2 are separated. The motor pulls the slider 3 to move the slider 3 and the upper clamp 1 upward at the same time to continue the tensile test. There is no need to assemble the clamp again, and the first fixing member is always in a fixed state during the whole process, so that the solid propellant specimen 4 will not rebound during the subsequent stretching process, which simplifies the test process and improves the accuracy of the test results.

[0035] The first fixing member may be a bolt or a stud.

[0036] See also Figure 2 The loading fixture 100 includes a second fixing member (not shown in the figure), first through holes 11 are opened on opposite sides of the upper fixture 1, and second through holes 21 are opened on opposite sides of the lower fixture 2. The second fixing member passes through the first through holes 11 and the second through holes 21 in sequence to fix the upper fixture 1 and the lower fixture 2.

[0037] Specifically, the second fixing member can be a bolt or a stud. After aligning the first through hole 11 and the second through hole 21, the second fixing member passes through the first through hole 11 and the second through hole 21 to fix the upper clamp 1 and the lower clamp 2. If the upper clamp 1 and the lower clamp 2 need to be separated, just remove the second fixing member. This arrangement is convenient to install and has a simple structure.

[0038] In one embodiment, the inner surface of the first through hole 11 is smooth, the inner surface of the second through hole 21 is threaded, the second fixing member passes through the first through hole 11 and is threadedly connected to the second through hole 21 , and the aperture of the first through hole 11 is larger than that of the second through hole 21 .

[0039] In order to facilitate the second fixing member to extend into the first through hole 11 and the second through hole 21, the present application sets the inner surface of the first through hole 11 to a smooth surface, so that it is more convenient for the second fixing member to extend into the first through hole 11. Compared with the threaded hole, the smooth first through hole 11 does not require the second fixing member to align with the thread to extend into, and the second fixing member can be extended vertically into the first through hole 11. The second through hole 21 is provided with threads to facilitate threaded connection with the second fixing member to achieve fixation of the upper clamp 1 and the lower clamp 2.

[0040] The aperture of the first through hole 11 is larger than that of the second through hole 21. Thus, the first through hole 11 and the second through hole 21 do not need to be completely aligned, and the second fixing piece can also pass through the first through hole 11 and extend into the second through hole 21 to be threadedly connected thereto. This arrangement is more convenient during assembly and simplifies the drilling process of the upper clamp 1 and the lower clamp 2. The second fixing piece only needs to pass through the first through hole 11 and be threadedly connected to the second through hole 21 to achieve fixation, thus saving the use of nuts.

[0041] See again Figure 2 The upper clamp 1 includes a first main body portion 14 and a first step portion 15, and the first step portion 15 is connected to the opposite sides of the first main body portion 14. The lower clamp 2 includes a second main body portion 22 and a second step portion 25, and the second main body portion 22 is connected to the second step portion 25 on the opposite sides. The first through hole 11 is opened in the first step portion 15, and the second through hole 21 is opened in the second step portion 25; wherein the first step portion 15 is used to abut against the lower clamp 2, and the second step portion 25 is used to abut against the upper clamp 1.

[0042] In actual application, when the upper clamp 1 and the lower clamp 2 are connected, the first step portion 15 just abuts against the lower clamp 2, and the second step portion 25 just abuts against the upper clamp 1. In this way, the first step portion 15 and the second step portion 25 play a positioning role, and the first through hole 11 and the second through hole 21 can be aligned through the abutment position of the first step portion 15 and the second step portion 25, which simplifies the assembly process of the loading clamp 100.

[0043] More specifically, the first step portion 15 is connected to the outer side of the first main body portion 14, and the first step portion 15 is used to abut against the outer side of the lower clamp 2; the second step portion 25 is connected to the inner side of the second main body portion 22, and the second step portion 25 is used to abut against the inner side of the first main body portion 14. This arrangement enhances the connection stability of the loading clamp 100.

[0044] Since the above-mentioned first through hole 11 is a smooth through hole, the second fixing piece is first extended into the first through hole 11, and the first step portion 15 is arranged on the outer side of the first main body portion 14, and the second step portion 25 is arranged on the inner side of the second main body portion 22. When the upper clamp 1 and the lower clamp 2 are connected, the first step portion 15 is located on the outside, which is convenient for the operator to extend the second fixing piece into the first through hole 11, which is beneficial to the installation and disassembly of the second fixing piece.

[0045] See again Figure 2 A slide groove 12 is provided on opposite sides of one of the upper clamp 1 and the sliding block 3 , and the other of the upper clamp 1 and the sliding block 3 is slidably connected to the slide groove 12 .

[0046] In one embodiment, a slide groove 12 is opened on the opposite sides of the upper clamp 1, and the slider 3 is slidably connected to the slide groove 12 to realize the sliding connection between the slider 3 and the upper clamp 1. The slider 3 is more stable when sliding, and the sliding heights on both sides are consistent without tilting, which is convenient for loading tests before aging.

[0047] The slider 3 is provided with a fixing groove 31 along its length direction X, and the upper fixture 1 is provided with a fixing hole 13, the fixing groove 31 is communicated with the fixing hole 13, and the first fixing member is passed through the fixing groove 31 and the fixing hole 13 and is threadedly connected to fix the slider 3 and the upper fixture 1.

[0048] In actual application, the fixing groove 31 extends along the length direction X of the slider 3. In this way, when the slider 3 slides to different positions, the fixing groove 31 is still connected to the fixing hole 13, and the first fixing piece passes through the fixing groove 31 and is threadedly connected to the fixing hole 13 to fix the slider 3 and the upper clamp 1.

[0049] In one embodiment, the slider 3 is provided with a plurality of fixing grooves 31 along the width direction Y thereof, and the upper fixture 1 is provided with a plurality of fixing holes 13 along the width direction Y thereof, and the plurality of fixing grooves 31 corresponds to the plurality of fixing holes 13 one by one.

[0050] In order to strengthen the fixed connection between the slider 3 and the upper clamp 1, the slider 3 is provided with a plurality of fixing grooves 31, and the upper clamp 1 is provided with a plurality of fixing holes 13. Thus, there are also a plurality of first fixing members, and the plurality of first fixing members fix the slider 3 and the upper clamp 1, thereby effectively strengthening the connection stability between the slider 3 and the upper clamp 1, preventing the slider 3 from sliding relative to the upper clamp 1, and avoiding affecting the tensile test.

[0051] In an alternative embodiment, the upper clamp 1 is provided with a plurality of fixing holes 13 along the extension direction of the fixing groove 31 , so that a plurality of first fixing members are respectively threadedly connected to the plurality of fixing holes 13 , which can also enhance the connection stability between the slider 3 and the upper clamp 1 .

[0052] See also Figure 3 The slider 3 includes a third main body portion 32 and a first limiting portion 33. The first limiting portions 33 are provided on opposite sides of the third main body portion 32. The third main body portion 32 and the first limiting portion 33 enclose a first clamping groove 34. The first clamping groove 34 is used to clamp one end of the solid propellant specimen 4. The first limiting portion 33 is used to have a smooth curved surface on one side thereof that abuts against the solid propellant specimen 4.

[0053] The slider 3 clamps the solid propellant specimen 4 through the first clamping groove 34, and the first limiting portion 33 abuts against the solid propellant specimen 4 to prevent the solid propellant specimen 4 from detaching during stretching. At the same time, one side of the first limiting portion 33 is a smooth curved surface, which can reduce the wear and tear between the first limiting portion 33 and the solid propellant specimen 4 and extend the service life of the clamp.

[0054] See also Figure 4 Similarly, the lower clamp 2 also includes a second limiting portion 23, and the second limiting portions 23 are provided on opposite sides of the second main body 22. The second main body 22 and the second limiting portion 23 enclose a second clamping groove 24, and the second clamping groove 24 is used to clamp the other end of the solid propellant specimen 4. The second limiting portion 23 is used to abut against the solid propellant specimen 4. The side of the second limiting portion 23 is a smooth curved surface. The second limiting portion 23 abuts against the solid propellant specimen 4 and prevents it from detaching. At the same time, the second limiting portion 23 has a smooth curved surface on one side, which effectively reduces the wear between the lower clamp 2 and the solid propellant specimen 4, and further extends the life of the clamp.

[0055] Different from the prior art, the embodiment of the present application provides a loading fixture 100, including an upper fixture 1, a lower fixture 2, a slider 3 and a first fixing member, the lower fixture 2 is detachably connected to the upper fixture 1, the slider 3 is slidably connected to the upper fixture 1, one end of the slider 3 is used to connect to the motor, and the other end is used to clamp one end of the solid propellant specimen 4, and the lower fixture 2 is used to clamp the other end of the solid propellant specimen 4; the first fixing member is respectively connected to the slider 3 and the upper fixture 1 to fix the slider 3 and the upper fixture 1. Compared with the prior art, the present application sets a slider 3, which is slidably connected to the upper clamp 1. Before the aging test, the solid propellant specimen 4 is stretched by moving the slider 3 relative to the upper clamp 1. The first fixing member fixes the slider 3 and the upper clamp 1 to prevent the solid propellant specimen 4 from rebounding. After the aging test, the upper clamp 1 and the lower clamp 2 are separated. The motor pulls the slider 3 to move the slider 3 and the upper clamp 1 upward at the same time to continue the tensile test. There is no need to assemble the clamp again, and the first fixing member is always in a fixed state during the whole process, so that the solid propellant specimen 4 will not rebound during the subsequent stretching process, which simplifies the test process and improves the accuracy of the test results.

[0056] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A loading fixture (100) for loading a solid propellant specimen (4), characterized in that: include: Upper fixture (1); A lower clamp (2) detachably connected to the upper clamp (1); A slider (3) is slidably connected to the upper fixture (1); one end of the slider (3) is used to connect to the motor, and the other end is used to clamp one end of the solid propellant specimen (4); and the lower fixture (2) is used to clamp the other end of the solid propellant specimen (4); A first fixing member is respectively connected to the slider (3) and the upper clamp (1) to fix the slider (3) and the upper clamp (1).

2. The loading fixture (100) according to claim 1, characterized in that: The loading fixture (100) comprises a second fixing member, first through holes (11) are provided on opposite sides of the upper fixture (1), second through holes (21) are provided on opposite sides of the lower fixture (2), and the second fixing member passes through the first through holes (11) and the second through holes (21) in sequence to fix the upper fixture (1) and the lower fixture (2).

3. The loading fixture (100) according to claim 2, characterized in that: The inner surface of the first through hole (11) is smooth, the inner surface of the second through hole (21) is provided with threads, the second fixing piece passes through the first through hole (11) and is threadedly connected to the second through hole (21), and the aperture of the first through hole (11) is larger than the aperture of the second through hole (21).

4. The loading fixture (100) according to claim 2, characterized in that: The upper clamp (1) comprises a first main body portion (14) and a first step portion (15), and the first step portion (15) is connected to two opposite sides of the first main body portion (14); the lower clamp (2) comprises a second main body portion (22) and a second step portion (25), and the second step portion (25) is connected to two opposite sides of the second main body portion (22); the first through hole (11) is provided in the first step portion (15), and the second through hole (21) is provided in the second step portion (25); wherein the first step portion (15) is used to abut against the lower clamp (2), and the second step portion (25) is used to abut against the upper clamp (1).

5. The loading fixture (100) according to claim 4, characterized in that: The first step portion (15) is connected to the outer side surface of the first main body portion (14), and the first step portion (15) is used to abut against the outer side of the lower clamp (2); the second step portion (25) is connected to the inner side surface of the second main body portion (22), and the second step portion (25) is used to abut against the inner side of the first main body portion (14).

6. The loading fixture (100) according to claim 1, characterized in that: Slide grooves (12) are provided on opposite sides of one of the upper clamp (1) and the sliding block (3), and the other of the upper clamp (1) and the sliding block (3) is slidably connected to the slide groove (12).

7. The loading fixture (100) according to claim 1, characterized in that: The slider (3) is provided with a fixing groove (31) along its length direction, the upper clamp (1) is provided with a fixing hole (13), the fixing groove (31) is communicated with the fixing hole (13), and the first fixing member is passed through the fixing groove (31) and the fixing hole (13) and is threadedly connected to fix the slider (3) and the upper clamp (1).

8. The loading fixture (100) according to claim 7, characterized in that: The sliding block (3) is provided with a plurality of fixing grooves (31) along its width direction, and the upper clamp (1) is provided with a plurality of fixing holes (13) along its width direction, and the plurality of fixing grooves (31) correspond to the plurality of fixing holes (13) one by one.

9. The loading fixture (100) according to claim 7, characterized in that: Along the extension direction of the fixing groove (31), the upper clamp (1) is provided with a plurality of fixing holes (13).

10. The loading fixture (100) according to claim 1, characterized in that: The slider (3) comprises a third main body (32) and a first limiting portion (33), the first limiting portions (33) being provided on opposite sides of the third main body (32), the third main body (32) and the first limiting portion (33) forming a first clamping groove (34), the first clamping groove (34) being used to clamp one end of the solid propellant specimen (4), and the first limiting portion (33) having a side that is used to abut against the solid propellant specimen (4) presenting a smooth curved surface; The lower clamp (2) comprises a second main body portion (22) and a second limiting portion (23), the second limiting portions (23) being provided on opposite sides of the second main body portion (22), the second main body portion (22) and the second limiting portion (23) forming a second clamping groove (24), the second clamping groove (24) being used to clamp the other end of the solid propellant specimen (4), and the second limiting portion (23) having a side that is used to abut against the solid propellant specimen (4) presenting a smooth curved surface.

Images