Plastic product fracture toughness testing mechanism

Abstract

The invention discloses a plastic product fracture toughness testing mechanism, and belongs to the technical field of plastic fracture toughness testing, the plastic product fracture toughness testing mechanism comprises a base station assembly used for placing a plastic product, and a pressure applying assembly used for applying fracture pressure to the plastic product is arranged on one side above the base station assembly; an observation assembly used for checking the plastic products is arranged on the other side of the upper portion of the base assembly, and a lighting assembly is arranged at the top of the base assembly. A first clamping assembly for fixing a plastic product is arranged on the base station assembly, and a second clamping assembly for secondarily fixing the plastic product is arranged on the first clamping assembly; the base station assembly is provided with a transmission assembly used for synchronously driving the first clamping assembly and the second clamping assembly, and the base station assembly is provided with a rotating assembly used for driving the lighting assembly to rotate in a surrounding mode. The bottom of the base station assembly is provided with a driving assembly used for driving the base station assembly to move linearly, and the transmission assembly and the rotating assembly are driven through the driving assembly. And the reliability of the test result is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic fracture toughness testing, and particularly to a fracture toughness testing mechanism for plastic products. Background Art

[0002] As an important material in modern industry and daily life, plastic products are widely used in various fields. Since plastic materials are often subjected to external forces such as impact, tension, or bending during use, their fracture toughness (i.e., the ability of the material to resist fracture under load) is an important indicator to measure the quality and performance of plastic products. To ensure the safety and service life of plastic products, it is necessary to accurately test and evaluate their fracture toughness. In the existing technology, the following problems mainly exist in the fracture toughness testing mechanism for plastic products:

[0003] During the fracture toughness testing process of plastic products, there are often problems of unstable fixation and incomplete observation. Since most of the existing clamping devices adopt rigid clamping structures, it is easy to cause uneven stress on the plastic products during clamping, and the specimen may be damaged during the testing process, affecting the accuracy and consistency of the test results. In addition, the observation position of plastic products during the testing process is fixed, and it is difficult to dynamically adjust according to the changes in the testing environment, resulting in observation blind spots during the testing process and unable to completely record the fracture deformation results of the specimen.

[0004] Therefore, we propose a fracture toughness testing mechanism for plastic products. Summary of the Invention

[0005] In order to overcome the deficiencies of the existing technology, the present invention provides a fracture toughness testing mechanism for plastic products, which significantly improves the test accuracy, operation convenience, and reliability of the test results through the efficient cooperation and precise control among various components.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A fracture toughness testing mechanism for plastic products, including a base component for placing plastic products, a pressing component for applying fracture pressure to plastic products is arranged on one side above the base component, an observation component for viewing plastic products is arranged on the other side above the base component, and a lighting component is arranged on the top of the base component;

[0008] A first clamping component for fixing plastic products is arranged on the base component, and a second clamping component for secondary fixing of plastic products is arranged on the first clamping component;

[0009] A transmission component for synchronously driving the first clamping component and the second clamping component is provided on the base component. The transmission component includes an outer cylinder, an inner ring, and a first gear ring. A rotating component for driving the lighting component to rotate around is provided on the base component. The rotating component includes a bottom cylinder and a second gear ring;

[0010] A driving component for driving the base component to move linearly is provided at the bottom of the base component. By means of the driving component, the transmission component and the rotating component are respectively driven.

[0011] As a preferred solution of the plastic product fracture toughness testing mechanism of the present invention, wherein: the base component includes a bottom plate, a supporting table, a cushion plate, and a pressure sensor. The supporting table is located at the center of the top surface of the bottom plate. The cushion plate is connected between the bottom surfaces of both sides of the supporting table and the top surface of the bottom plate. The pressure sensor is embedded in the top surface of the cushion plate.

[0012] As a preferred solution of the plastic product fracture toughness testing mechanism of the present invention, wherein: the pressing component includes a fixing plate, a support frame, and a telescopic cylinder. The bottom plate is located above the top surface of the fixing plate. The support frame is connected to the top of the fixing plate and covers above the top surface of the supporting table. The telescopic cylinder is installed at the top of the support frame.

[0013] As a preferred solution of the plastic product fracture toughness testing mechanism of the present invention, wherein: the observation component includes a camera. The camera is installed at the top of the support frame. The camera and the telescopic cylinder are respectively arranged on both sides of the top of the support frame.

[0014] As a preferred solution of the plastic product fracture toughness testing mechanism of the present invention, wherein: the first clamping component includes an elastic plate, a clamping plate, and a pressing plate. Square holes are equidistantly formed on the side wall of the supporting table along the outer circumferential surface, and the square holes extend to the inner bottom surface of the supporting table. The elastic plate is located inside the square holes and is fixedly connected between the top of the elastic plate and the inner top surface of the square holes. The clamping plate is connected to the inner top of the elastic plate. The clamping plate is obliquely arranged and the lower end is located inside the supporting table. The pressing plate is connected to the outer bottom of the elastic plate. The pressing plate is obliquely arranged and the upper end is located outside the supporting table.

[0015] As a preferred solution of the plastic product fracture toughness testing mechanism of the present invention, wherein: the second clamping component includes an air cushion and an airbag. The air cushion is arranged on the inner side surface of the elastic plate and is covered by the clamping plate. Through holes for the air cushion to penetrate are formed on the surface of the clamping plate. The airbag is arranged on the outer side surface of the elastic plate and is covered by the pressing plate. Air holes for internal communication between the airbag and the air cushion are formed on the elastic plate.

[0016] As a preferred embodiment of the fracture toughness testing mechanism for plastic products according to the present invention, the following is provided: The inner ring is sleeved on the outer circumferential surface of the supporting table and is slidably connected up and down therebetween. The outer cylinder is rotatably arranged on the top surface of the bottom plate and coaxially sleeves the supporting table. The inner circumferential surface of the outer cylinder is in screw engagement with the outer circumferential surface of the inner ring. The first gear ring is coaxially connected to the inner side wall of the lower end of the outer cylinder, and the first gear ring is located below the inner ring.

[0017] As a preferred embodiment of the fracture toughness testing mechanism for plastic products according to the present invention, the following is provided: The lighting assembly includes a lifting lamp holder and a supplementary light. The lifting lamp holders are distributed in a circular array on the top surface of the bottom cylinder. The supplementary light is connected to the top of the lifting lamp holder and faces the supporting table. The bottom cylinder is rotatably arranged on the outer circumferential surface of the bottom plate. The second gear ring is coaxially connected to the inner side wall of the lower end of the bottom cylinder, and the second gear ring is located below the bottom surface of the bottom plate.

[0018] As a preferred embodiment of the fracture toughness testing mechanism for plastic products according to the present invention, the following is provided: The driving assembly includes a lead screw, a positioning rod, a connecting sleeve, a guiding cylinder, and a worm. There are two positioning rods and they are parallelly distributed on both sides of the lead screw. The lead screw and the positioning rods are both rotatably arranged between the two sides of the bottom end of the support frame. The ends of the lead screw and the positioning rods both extend outside the support frame and are connected with hand wheels. The connecting sleeve and the guiding cylinder are both fixedly connected to the bottom surface of the bottom plate. The connecting sleeve is threadedly sleeved on the outer surface of the lead screw. The inside of the worm is hollow and slidably sleeved on the outer surface of the positioning rod. The inner circumferential surface of the worm is in circumferential engagement with the outer circumferential surface of the positioning rod. The guiding cylinders are located at both ends of the worm and are movably sleeved on the outer surface of the positioning rod. The guiding cylinder is fixedly connected to the connecting sleeve.

[0019] As a preferred embodiment of the fracture toughness testing mechanism for plastic products according to the present invention, the following is provided: The driving assembly further includes two sets of gear sets. The gear sets are rotatably arranged on the bottom plate. One set of the gear sets is in transmission connection between one side of the worm and the first gear ring, and the other set of the gear sets is in transmission connection between the other side of the worm and the second gear ring.

[0020] Compared with the prior art, the beneficial effects that the present invention can achieve are:

[0021] Through the reasonable configuration and efficient linkage of each component, the testing accuracy, operation convenience, and reliability of the test results are significantly improved, successfully solving the deficiencies of traditional fracture toughness testing devices in terms of accuracy, stability, synchronous control, observation and recording, etc.;

[0022] The cooperative design of the pressing component and the pressure sensor is adopted, which can apply a constant and accurate fracture load to the plastic product. Through the real-time feedback of the pressure sensor, the applied load can be dynamically adjusted to ensure uniform application of the load, significantly improving the accuracy and consistency of the test;

[0023] The dual clamping design of the first clamping component and the second clamping component utilizes the first clamping component to provide preliminary elastic support, and the second clamping component realizes flexible clamping through an air cushion. Finally, the transmission component controls the synchronous movement of the clamping components to ensure the stability of the fixed plastic product.

[0024] The observation component and the lighting component are used in combination, enabling a comprehensive observation of the plastic product at different light angles. Through the flexible adjustment of the rotation component, the lighting component can change its position according to the test environment, achieving dynamic adjustment and ensuring clear visibility throughout the test process.

[0025] The linkage design of the drive component, the transmission component, and the rotation component enables the device to achieve synchronous control, reducing the operation difficulty. The precise cooperation of the gear set and the worm structure makes the rotation, clamping, and loading actions of the device smoother and more accurate, improving the test efficiency. Description of the Drawings

[0026] Figure 1 It is a schematic structural diagram of a fracture toughness test mechanism for plastic products.

[0027] Figure 2 It is a schematic diagram of the support frame of a fracture toughness test mechanism for plastic products.

[0028] Figure 3 It is a schematic diagram of the bottom cylinder of a fracture toughness test mechanism for plastic products.

[0029] Figure 4 It is a schematic diagram of the support table of a fracture toughness test mechanism for plastic products.

[0030] Figure 5 It is a schematic diagram of the bottom plate of a fracture toughness test mechanism for plastic products.

[0031] Figure 6 It is a schematic diagram of the inner ring of a fracture toughness test mechanism for plastic products.

[0032] Figure 7 It is a schematic diagram of the elastic plate of a fracture toughness test mechanism for plastic products.

[0033] Figure 8 It is a schematic diagram of the worm of a fracture toughness test mechanism for plastic products.

[0034] Wherein: 1. Fixed plate; 2. Support frame; 3. Telescopic cylinder; 4. Camera; 5. Outer cylinder; 6. Bottom cylinder; 7. Lead screw; 8. Second gear ring; 9. Positioning rod; 10. Handwheel; 11. Connecting sleeve; 12. Worm; 13. Gear set; 14. Lifting lamp holder; 15. Supplementary light; 16. Support table; 17. Clamp; 18. Through hole; 19. First gear ring; 20. Inner ring; 21. Pressure plate; 22. Airbag; 23. Pad; 24. Pressure sensor; 25. Bottom plate; 26. Elastic plate; 27. Square hole; 28. Air cushion; 29. Air hole; 30. Guide cylinder. Detailed implementation manners

[0035] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will give a detailed description of the specific implementation manners of the present invention in conjunction with the accompanying drawings of the specification.

[0036] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0037] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0038] Embodiment

[0039] Please refer to Figures 1 to 8 As shown, the present invention provides a test mechanism for the fracture toughness of plastic products, including a base assembly for placing plastic products. The base assembly includes a bottom plate 25, a support table 16, a pad 23, and a pressure sensor 24. The support table 16 is located at the center of the top surface of the bottom plate 25. The pad 23 is connected between the bottom surfaces of both sides of the support table 16 and the top surface of the bottom plate 25. The pressure sensor 24 is embedded in the top surface of the pad 23. On one side above the base assembly, there is a pressing assembly for applying a fracture pressure to the plastic products. On the other side above the base assembly, there is an observation assembly for viewing the plastic products. A lighting assembly is provided on the top of the base assembly;

[0040] The supporting platform 16 serves as the bearing platform for the sample, ensuring the stability of the sample position during the test. The backing plate 23 connects the supporting platform 16 and the bottom plate 25, enhancing the stability of the overall structure. The pressure sensor 24 is embedded in the top surface of the backing plate 23 to monitor the load magnitude applied to the sample in real time, ensuring that the applied load is precisely controllable. The telescopic cylinder 3 is supported by the fixing plate 1 and the support frame 2 and can apply pressure precisely in the vertical direction. Under the feedback of the pressure sensor 24, the pressing force is controllable, ensuring stable and consistent test conditions.

[0041] The pressure application assembly includes a fixing plate 1, a support frame 2, and a telescopic cylinder 3. The bottom plate 25 is located above the top surface of the fixing plate 1. The support frame 2 is connected to the top of the fixing plate 1 and covers above the top surface of the supporting platform 16. The telescopic cylinder 3 is installed on the top of the support frame 2. The observation assembly includes a camera 4, and the camera 4 is installed on the top of the support frame 2. The camera 4 and the telescopic cylinder 3 are respectively arranged on both sides of the top of the support frame 2.

[0042] The camera 4 is installed on the top of the support frame 2 with precise positioning, and can monitor the deformation and fracture conditions of the sample in real time during the test. The position of the camera 4 does not interfere with that of the pressure application assembly, ensuring a clear shooting angle. The lighting assembly realizes light compensation and visualization enhancement. The supplementary light 15 is installed on the lifting lamp stand 14, and the lighting direction is adjustable to ensure uniform light on the surface of the sample. The cooperation between the bottom cylinder 6 and the second gear ring 8 enables the light to rotate and change its position for surrounding illumination, avoiding the observation blind area caused by insufficient light.

[0043] The base platform assembly is provided with a first clamping assembly for fixing plastic products. The first clamping assembly includes an elastic plate 26, a clamping plate 17, and a pressing plate 21. Square holes 27 are equidistantly formed on the side wall of the supporting platform 16 along the outer circumferential surface, and the square holes 27 extend to the inner bottom surface of the supporting platform 16. The elastic plate 26 is located inside the square holes 27, and the top of the elastic plate 26 is fixedly connected to the inner top surface of the square holes 27. The clamping plate 17 is connected to the inner top of the elastic plate 26. The clamping plate 17 is obliquely arranged and its lower end is located inside the supporting platform 16. The pressing plate 21 is connected to the outer bottom of the elastic plate 26. The pressing plate 21 is obliquely arranged and its upper end is located outside the supporting platform 16.

[0044] The first clamping assembly is provided with a second clamping assembly for secondary fixing of plastic products. The second clamping assembly includes an air cushion 28 and an airbag 22. The air cushion 28 is arranged on the inner side surface of the elastic plate 26 and is covered by the clamping plate 17. Through holes 18 for the air cushion 28 to penetrate are formed on the surface of the clamping plate 17. The airbag 22 is arranged on the outer side surface of the elastic plate 26 and is covered by the pressing plate 21. Air holes 29 for internal communication between the airbag 22 and the air cushion 28 are formed on the elastic plate 26.

[0045] The first clamping assembly and the second clamping assembly are double clamped. The elastic plate 26, the clamping plate 17 and the pressing plate 21 of the first clamping assembly cooperate to provide a primary elastic fixing effect to ensure accurate positioning of the sample. The second clamping assembly realizes flexible wrapping and fixing of the sample through the combined action of the air cushion 28 and the air bag 22 to prevent the inaccurate test result caused by the sliding or loosening of the sample during the test. The outer cylinder 5 and the inner ring 20 are screwed together through threads to realize synchronous drive, ensuring that the first clamping assembly and the second clamping assembly move synchronously and keep the force uniform.

[0046] The base assembly is provided with a transmission assembly for synchronously driving the first clamping assembly and the second clamping assembly, and the transmission assembly includes an outer cylinder 5, an inner ring 20 and a first gear ring 19. The inner ring 20 is sleeved on the outer circumferential surface of the support platform 16 and is slidably connected to each other up and down. The outer cylinder 5 is rotatably arranged on the top surface of the bottom plate 25 and coaxially sleeves the support platform 16. The inner circumferential surface of the outer cylinder 5 is threadedly engaged with the outer circumferential surface of the inner ring 20. The first gear ring 19 is coaxially connected to the inner side wall of the lower end of the outer cylinder 5, and the first gear ring 19 is located below the inner ring 20.

[0047] The base assembly is provided with a rotating assembly for driving the lighting assembly to rotate around, the rotating assembly includes a bottom cylinder 6 and a second gear ring 8, the lighting assembly includes a lifting lamp holder 14 and a fill light 15, the lifting lamp holder 14 is distributed in a circular array on the top surface of the bottom cylinder 6, the fill light 15 is connected to the top of the lifting lamp holder 14 and faces the supporting platform 16, the bottom cylinder 6 is rotatably arranged on the outer circumferential surface of the bottom plate 25, the second gear ring 8 is coaxially connected to the inner side wall of the lower end of the bottom cylinder 6, and the second gear ring 8 is located below the bottom surface of the bottom plate 25;

[0048] A driving assembly for driving its linear motion is provided at the bottom of the base assembly, and the transmission assembly and the rotating assembly are driven respectively by the driving assembly. The driving assembly includes a screw 7, a positioning rod 9, a connecting sleeve 11, a guide cylinder 30 and a worm 12. The positioning rod 9 has two and is parallelly distributed on both sides of the screw 7. The screw 7 and the positioning rod 9 are both rotatably arranged between the two sides of the bottom end of the support frame 2. The ends of the screw 7 and the positioning rod 9 extend to the outside of the support frame 2 and are connected to a handwheel 10. The connecting sleeve 11 and the guide cylinder 30 are both connected and fixed to the bottom surface of the bottom plate 25. The connecting sleeve 11 is threadedly sleeved on the screw 7, the interior of the worm 12 is hollow and slidably sleeved on the outer surface of the positioning rod 9, the inner circumferential surface of the worm 12 is engaged with the outer circumferential surface of the positioning rod 9 in the circumferential direction, the guide cylinder 30 is located at both ends of the worm 12 and movably sleeved on the outer surface of the positioning rod 9, the guide cylinder 30 is connected and fixed with the connecting sleeve 11, the driving assembly also includes two sets of gear sets 13, the gear sets 13 are rotatably set on the bottom plate 25, one set of gear sets 13 is transmission-connected between the worm 12 on one side and the first gear ring 19, and the other set of gear sets 13 is transmission-connected between the worm 12 on the other side and the second gear ring 8;

[0049] Through the linkage of the lead screw 7 and the positioning rod 9, the driving assembly can adjust the first clamping assembly, the second clamping assembly, the transmission assembly and the rotating assembly respectively.

[0050] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A test mechanism for the fracture toughness of plastic products, including a base component for placing plastic products, characterized in that: On one side above the base component, there is a pressing component for applying breaking pressure to plastic products. On the other side above the base component, there is an observation component for viewing plastic products. On the top of the base component, there is a lighting component; On the base component, there is a first clamping component for fixing plastic products, and on the first clamping component, there is a second clamping component for secondary fixing of plastic products; On the base component, there is a transmission component for synchronously driving the first clamping component and the second clamping component. The transmission component includes an outer cylinder (5), an inner ring (20) and a first gear ring (19). On the base component, there is a rotating component for driving the lighting component to rotate around. The rotating component includes a bottom cylinder (6) and a second gear ring (8); At the bottom of the base component, there is a driving component for driving its linear motion, and through the driving component, the transmission component and the rotating component are respectively driven.

2. The fracture toughness testing mechanism for plastic products according to claim 1, characterized in that: The base component includes a bottom plate (25), a supporting platform (16), a cushion plate (23) and a pressure sensor (24). The supporting platform (16) is located at the center of the top surface of the bottom plate (25). The cushion plate (23) is connected between the bottom surfaces of both sides of the supporting platform (16) and the top surface of the bottom plate (25). The pressure sensor (24) is embedded in the top surface of the cushion plate (23).

3. The fracture toughness testing mechanism for plastic products according to claim 2, characterized in that: The pressing component includes a fixing plate (1), a support frame (2) and a telescopic cylinder (3). The bottom plate (25) is located above the top surface of the fixing plate (1). The support frame (2) is connected to the top of the fixing plate (1) and covers above the top surface of the supporting platform (16). The telescopic cylinder (3) is installed on the top of the support frame (2).

4. A plastic product fracture toughness testing mechanism according to claim 3, characterized in that: The observation component includes a camera (4). The camera (4) is installed on the top of the support frame (2). The camera (4) and the telescopic cylinder (3) are respectively arranged on both sides of the top of the support frame (2).

5. The fracture toughness testing mechanism for plastic products according to claim 2, wherein: The first clamping component includes an elastic plate (26), a clamping plate (17) and a pressing plate (21). Square holes (27) are equidistantly formed on the side wall of the supporting platform (16) along the outer circumferential surface. The square holes (27) extend to the inner bottom surface of the supporting platform (16). The elastic plate (26) is located inside the square holes (27), and the top of the elastic plate (26) is fixedly connected to the inner top surface of the square holes (27). The clamping plate (17) is connected to the inner top of the elastic plate (26). The clamping plate (17) is obliquely arranged and its lower end is located inside the supporting platform (16). The pressing plate (21) is connected to the outer bottom of the elastic plate (26). The pressing plate (21) is obliquely arranged and its upper end is located outside the supporting platform (16).

6. The fracture toughness testing mechanism for plastic products according to claim 5, wherein: The second clamping component includes an air cushion (28) and an air bag (22). The air cushion (28) is arranged on the inner side surface of the elastic plate (26) and covered by the clamping plate (17). Through holes (18) for the air cushion (28) to penetrate are formed on the surface of the clamping plate (17). The air bag (22) is arranged on the outer side surface of the elastic plate (26) and covered by the pressing plate (21). Air holes (29) for internal communication between the air bag (22) and the air cushion (28) are formed on the elastic plate (26).

7. The fracture toughness testing mechanism for plastic products according to claim 2, wherein: The inner ring (20) is sleeved on the outer circumferential surface of the supporting platform (16) and is slidably connected up and down therebetween. The outer cylinder (5) is rotatably arranged on the top surface of the bottom plate (25) and coaxially sleeves the supporting platform (16). The inner circumferential surface of the outer cylinder (5) is threadedly engaged with the outer circumferential surface of the inner ring (20). The first gear ring (19) is coaxially connected to the inner side wall of the lower end of the outer cylinder (5), and the first gear ring (19) is located below the inner ring (20).

8. A plastic product fracture toughness testing mechanism according to claim 2, characterized in that: The lighting assembly includes a lifting lamp holder (14) and a supplementary lamp (15). The lifting lamp holders (14) are distributed in a circular array on the top surface of the bottom cylinder (6). The supplementary lamp (15) is connected to the top of the lifting lamp holder (14) and faces the supporting platform (16). The bottom cylinder (6) is rotatably arranged on the outer circumferential surface of the bottom plate (25). The second gear ring (8) is coaxially connected to the inner side wall of the lower end of the bottom cylinder (6), and the second gear ring (8) is located below the bottom surface of the bottom plate (25).

9. The fracture toughness testing mechanism for plastic products according to claim 3, characterized in that: The driving assembly includes a lead screw (7), a positioning rod (9), a connecting sleeve (11), a guiding cylinder (30) and a worm (12). There are two positioning rods (9) which are parallelly distributed on both sides of the lead screw (7). The lead screw (7) and the positioning rod (9) are both rotatably arranged between the two sides of the bottom end of the support frame (2). The ends of the lead screw (7) and the positioning rod (9) both extend to the outside of the support frame (2) and are connected with a hand wheel (10). The connecting sleeve (11) and the guiding cylinder (30) are both fixedly connected to the bottom surface of the bottom plate (25). The connecting sleeve (11) is threadedly sleeved on the outer surface of the lead screw (7). The inside of the worm (12) is hollow and slidably sleeved on the outer surface of the positioning rod (9). The inner circumferential surface of the worm (12) is circumferentially engaged with the outer circumferential surface of the positioning rod (9). The guiding cylinder (30) is located at both ends of the worm (12) and is movably sleeved on the outer surface of the positioning rod (9). The guiding cylinder (30) is fixedly connected to the connecting sleeve (11).

10. A plastic product fracture toughness testing mechanism according to claim 9, characterized in that: The driving assembly further includes two sets of gear sets (13). The gear sets (13) are rotatably arranged on the bottom plate (25). One set of the gear sets (13) is drivingly connected between one side of the worm (12) and the first gear ring (19), and the other set of the gear sets (13) is drivingly connected between the other side of the worm (12) and the second gear ring (8).

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