EVA (Ethylene Vinyl Acetate) adhesive film tension testing device

Abstract

The invention relates to the technical field of tension testing, and discloses an EVA adhesive film tension testing device which comprises a driving motor and a driving lead screw, a supporting plate is arranged between the tops of two stand columns, the driving lead screw is used for driving a cross beam to slide up and down, the driving motor is used for driving the driving lead screw to rotate, a testing cover is arranged on a base, and the testing cover is arranged on the base. The test cover is located below the cross beam, a connecting assembly is arranged at the bottom of the cross beam, the test cover is telescopic, the top of the test cover is detachably connected with the cross beam through the connecting assembly, the test cover is made of a high-temperature-resistant fireproof cloth material, and the test cover is communicated with a heater and an air conditioning unit through pipelines. According to the high-low-temperature tensile testing machine, the gauge length between the upper clamp and the lower clamp can be conveniently observed and adjusted before an EVA adhesive film sample is clamped, so that the testing efficiency is improved, meanwhile, tensile testing can be performed on samples with different lengths in high-temperature and low-temperature environments, and the application range of the high-low-temperature tensile testing machine is expanded.

Description

Technical Field

[0001] This application relates to the field of tensile testing technology, and in particular to an EVA film tensile testing device. Background Art

[0002] EVA film, also known as EVA hot melt adhesive film, is a hot melt adhesive film product based on ethylene-vinyl acetate copolymer (EVA). It is a colorless transparent or foggy polymer, odorless, tasteless, and non-toxic. EVA hot melt adhesive film usually contains 60%-90% of EVA components. This material is solid at room temperature and will melt into a viscous liquid when heated to a certain temperature, and re-solidify after cooling to form a firm bond. Therefore, EVA film is widely used in material lamination and bonding in various industries, such as shoe material lamination, luggage lamination, wall cloth lamination, automotive interior lamination, etc. In addition, due to its good properties in adhesion, durability, optical properties, etc., it is also widely used in fields such as solar cell encapsulation and electronic and electrical component sealing.

[0003] After the EVA film is produced and formed, a tensile testing machine is required to test its tensile properties. Since the EVA film is also widely used in fields such as battery encapsulation and electronic component sealing, it means that the EVA film also needs to be suitable for application environments at high temperatures. Therefore, it is also necessary to conduct tensile tests on the EVA film in a high-temperature environment.

[0004] The Chinese utility model patent with the authorization publication number of CN214096980U discloses a high and low temperature tensile testing machine, which includes a base and two columns. A cross beam slides up and down between the two columns. An upper clamp is provided in the middle of the cross beam. A test chamber is provided between the cross beam and the base. The upper clamp extends into the test chamber. A lower clamp is installed at the bottom of the test chamber. The upper clamp and the lower clamp are used to clamp the test sample. A servo motor, a reducer, and a lead screw are provided in the column to drive the cross beam to slide up and down, so as to stretch the test sample. An air duct is provided in the test chamber. A fan, a heater, and a temperature sensor are provided in the air duct. An equipment placement box is provided on the side of the test chamber. An air conditioner unit is provided in the equipment placement box. The air conditioner unit is connected to the air duct through a pipeline. The heater is used to heat the test chamber to simulate a high-temperature environment for tensile testing; the air conditioner unit is used to cool the test chamber to simulate a low-temperature environment for tensile testing.

[0005] In view of the above related technologies, the inventors found the following problems: 1. The upper fixture can only slide inside the test chamber. When testing an EVA film sample with a relatively long length, the film needs to be stretched over a relatively long distance before it breaks. However, the height of the test chamber is limited, and the ductility of the film is high. Therefore, there may be a situation where the film has not broken yet when the upper fixture has slid to the top inside the test chamber, resulting in a failed test. 2. In this solution, both the upper and lower fixtures are fixed inside the test chamber. Before clamping the sample, it is necessary to adjust the gauge length between the upper and lower fixtures according to the sample length. After the adjustment is completed, it is also necessary to measure the distance between the two fixtures with a ruler. However, since both fixtures are inside the test chamber, it is not convenient for the test personnel to perform the operations of adjusting the distance and measuring, which reduces the test efficiency. Summary of the Invention

[0006] In order to facilitate observing and adjusting the gauge length between the upper and lower fixtures before clamping the EVA film sample, thereby improving the test efficiency, and at the same time being able to perform tensile tests on samples of different lengths in high-temperature and low-temperature environments, expanding the applicable range of the high-low temperature tensile testing machine, the present application provides an EVA film tensile testing device.

[0007] The EVA film tensile testing device provided by the present application adopts the following technical solutions: An EVA film tensile testing device includes a base. Two columns are provided on the base. A lower fixture is installed on the base. A cross beam is slidably connected up and down between the two columns. An upper fixture is installed on the bottom surface of the cross beam. It also includes a heater and an air-conditioning unit, which are respectively used to provide a high-temperature environment and a low-temperature environment for the test. It further includes a driving motor and a driving lead screw. A support plate is provided between the tops of the two columns. The driving lead screw is rotatably connected between the base and the support plate and is located inside one column. The driving lead screw is used to drive the cross beam to slide up and down. The driving motor is used to drive the driving lead screw to rotate. A test cover is provided on the base. The test cover is located below the cross beam. A connecting component is provided at the bottom of the cross beam. The test cover is telescopic. The top of the test cover is detachably connected to the cross beam through the connecting component. The test cover is made of high-temperature resistant and fireproof cloth material. The test cover is communicated with the heater and the air-conditioning unit through a pipeline.

[0008] By adopting the above technical solution, before clamping the EVA film sample, the test cover is first in a contracted state. At this time, both the upper and lower clamps are located above the test cover, and the test cover does not block them. Thus, it is convenient to observe the distance between the upper and lower clamps, and the crossbeam can be moved up and down according to the length of the sample to adjust the gauge length between the upper and lower clamps. Then, the distance between them is measured with a ruler. Since there is no obstruction, it is convenient to adjust while observing, improving the test efficiency. After clamping the EVA film sample between the upper and lower clamps, the top of the test cover can be fixed to the crossbeam through the connection component. At this time, both the upper and lower clamps are located inside the test cover, and then the inside of the test cover is heated or cooled by the heater and the air conditioning unit, so as to provide a high-temperature or low-temperature environment for the tensile test. The drive motor is started, and the drive motor drives the drive screw to rotate. The drive screw drives the crossbeam to slide upward, and the crossbeam drives the upper clamp to slide upward, thereby stretching the EVA film sample. During the stretching process, the crossbeam drives the test cover to expand, so as to be applicable to samples with different stretching lengths and expand the application range of the high and low temperature tensile testing machine.

[0009] Optionally, an observation plate is hinged between the two columns. The observation plate is made of high-temperature resistant glass material, and an indicating scale is vertically marked on the observation plate. A pointer is horizontally and fixedly connected to the middle of the upper clamp, and the zero scale line of the indicating scale is aligned with the middle position of the lower clamp.

[0010] By adopting the above technical solution, when adjusting the distance between the upper and lower clamps, the height of the upper clamp can be adjusted while observing the position of the indicating scale pointed by the pointer, without measuring with a ruler after adjustment. Thus, it is convenient to determine the distance between the upper and lower clamps and improve the efficiency of distance adjustment.

[0011] Optionally, the bottom of the drive screw is rotationally connected to a rotating shaft through a bevel gear set. The other end of the rotating shaft is fixedly connected with an adjusting handwheel. A switching member is arranged on the support plate, and the switching member is used to disconnect the drive of the drive motor for the drive screw.

[0012] By adopting the above technical solution, when adjusting the distance, first use the switching member to disconnect the drive of the drive motor for the drive screw. At this time, the drive screw is converted from an electric drive to a manual drive mode. Then rotate the adjusting handwheel. The adjusting handwheel drives the rotating shaft to rotate. The rotating shaft drives the drive screw to rotate through the bevel gear set. The drive screw drives the crossbeam to slide up and down, thereby driving the upper clamp to slide. The pointer on the upper clamp indicates the indicating scale on the observation plate. The tester can slowly rotate the adjusting handwheel while observing the scale. When the pointer indicates the height to be adjusted, stop rotating the adjusting handwheel, thus completing the adjustment of the gauge length between the upper and lower clamps and making the distance adjustment more accurate and easy to control.

[0013] Optionally, a rotating pulley is coaxially and fixedly connected to the top of the driving lead screw, a driving pulley is coaxially and fixedly connected to the rotating shaft of the driving motor, the driving pulley and the rotating pulley are connected by a belt, the width of the driving pulley is greater than the width of the rotating pulley, the switching member includes a cylinder and a clamping block, an installation plate is further fixedly connected to the support plate, a fixed pulley is rotatably connected to the bottom surface of the installation plate, the fixed pulley is located above the rotating pulley and is coaxially arranged with the rotating pulley, the diameter of the fixed pulley is the same as that of the rotating pulley, the telescopic shaft of the cylinder is fixedly connected to the clamping block, and the clamping block is used for clamping the belt.

[0014] By adopting the above technical solution, when stretching, the cylinder extends, and the belt is driven downward by the clamping block to the rotating pulley, so that the driving motor can drive the driving lead screw. At this time, the driving of the driving lead screw is in the electric driving mode, and the stretching test can be carried out; when adjusting the distance, the cylinder contracts and drives the belt upward by the clamping block to the fixed pulley. At this time, the driving lead screw can be rotated by rotating the distance adjusting handwheel. At this time, the driving of the driving lead screw is in the manual driving mode, which is more convenient to control and observe during distance adjustment, and improves the accuracy of distance adjustment; at the same time, two control modes for one driving lead screw are realized through the switching member, so that the structure of the tensile test device remains concise while increasing the use function, thereby enhancing the functionality of the device.

[0015] Optionally, support frames are fixedly connected to both the top and the bottom of the test cover, the support frame at the bottom of the test cover is fixedly connected to the base, a hanging rod is arranged on the support frame at the top of the test cover, the connecting component includes a hook, and the hanging rod is used for hanging on the hook.

[0016] By adopting the above technical solution, when connecting the test cover and the cross beam, the hanging rod can be hung on the hook, so as to complete the connection of the test cover and the cross beam, and the operation is simple and convenient; when the test cover needs to be removed, the hanging rod is removed from the hook, and the disassembly of the test cover can be completed.

[0017] Optionally, a fixing groove is formed in the cross beam, the connecting component is located in the fixing groove, a fixing box is arranged on the top of the cross beam, the bottom surface of the fixing box is open, the connecting component includes a clamping rod, the clamping rod includes a first clamping rod and a second clamping rod, the second clamping rod is fixedly connected to the top of the first clamping rod, the top of the first clamping rod is rotatably connected in the fixing box, the hook is fixedly connected to the bottom of the first clamping rod, and a slider is vertically slidably connected in the fixing box, and the slider is used for driving the second clamping rod to rotate.

[0018] By adopting the above technical solution, the slider slides up and down, which can drive the second clamping rod to rotate up and down, thereby driving the bottom of the first clamping rod to rotate toward or away from the hanging rod, and then driving the hook to rotate toward or away from the hanging rod. When the hook rotates toward the hanging rod, the hanging rod is hung on the hook, thereby completing the fixation of the support frame, that is, completing the installation of the test cover; when the hook rotates toward the direction away from the hanging rod, the hook is disengaged from the hanging rod, thereby releasing the fixation of the support frame and allowing the test cover to be removed from the beam.

[0019] The top of the sliding panel also is provided with an interlock plate, and the interlock plate is fixedly mounted on the sliding panel and the interlock plate, and the interlock plate is fixedly mounted on the sliding panel.

[0020] When the cam is released, the slide column automatically slides into the first limit arc surface, driving the slider to slide downward, and the slider drives the guide plate to slide downward, and the guide plate pushes the connecting rod to rotate, so that its bottom moves in the direction away from the hanging rod, thereby causing the hook to be separated from the hanging rod, and the support frame can be removed. When installing and disassembling the test cover, it is only necessary to press the support frame upward twice to install and remove the support frame, thereby realizing the installation and disassembly of the test cover. The operation is simple and convenient. At the same time, the tester can choose to install or disassemble the test cover according to the test requirements. When conducting tests at room temperature, the test cover can be removed to facilitate observation and operation. When conducting tests in high-temperature and low-temperature environments, the test cover can be installed to facilitate providing high-temperature and low-temperature environments, improving the applicable range and convenience of the tensile test device.

[0021] Optionally, the width of the guiding channel is greater than the diameter of the sliding column. The guiding channel includes an inner guiding surface and an outer guiding surface. A channel for the sliding column to slide is formed between the inner guiding surface and the outer guiding surface. Both the inner guiding surface and the outer guiding surface are arranged in a diamond shape. The first limiting arc surface is located at the top of the outer guiding surface. A first guiding inclined surface is opened at the top of the inner guiding surface, and the first guiding inclined surface is directly below the first limiting arc surface. The second limiting arc surface is formed by bending the bottom of the inner guiding surface upward. The bottom of the outer guiding surface bends toward the direction close to the second limiting arc surface and forms a second guiding inclined surface and a third guiding inclined surface. The third guiding inclined surface is directly below the second limiting arc surface. The second guiding inclined surface deviates from the center of the second limiting arc surface in the vertical direction. A pause surface is provided between the second guiding inclined surface and the outer guiding surface.

[0022] By adopting the above technical solution, when installing the test cover, press the support frame upward. The push block pushes the push rod upward, and the push rod pushes the slider to slide upward. At this time, the sliding column on the positioning rod slides downward in the guiding channel. When sliding to the second guiding inclined surface, there is a sense of pause. At this time, the support frame can be released. Under the action of the spring, the sliding column automatically slides into the first limiting arc surface to lock the slider. At the same time, the guiding plate also pushes the bottom of the clamping rod to rotate toward the direction close to the hanging rod, so that the hook catches the hanging rod. The tester can know that the installation operation has been completed through the sense of pause, which plays a reminder role. When it is necessary to remove the support frame, press the support frame upward again. The push block pushes the push rod to slide upward, and the push rod pushes the slider to slide upward, so that the sliding column disengages from the second limiting arc surface. At this time, due to the guiding action of the third guiding inclined surface and the elastic force of the spring, the sliding column automatically slides into the first limiting arc surface, driving the slider to slide downward. At the same time, the slider drives the guiding plate to slide downward, and the guiding plate pushes the clamping rod to rotate, making its bottom move away from the hanging rod, so that the hook disengages from the hanging rod. At this time, the tester can know that the disassembly has been completed, and thus the test cover can be removed.

[0023] Optionally, the observation plate and one of the columns are connected by a spring pin. The spring pin includes a spring hanging ring and a limiting plate. The spring hanging ring is arranged on the observation plate, and the limiting plate is arranged on the column. The spring hanging ring is used to hang on the limiting plate. An observation port is vertically opened on one side of the test cover facing the observation plate, and the observation port is used to observe the stretching state of the EVA film sample.

[0024] By adopting the above technical solution, when conducting a tensile test in a high or low temperature environment, the spring hanging ring can be stretched and then hung on the limit plate, thereby completing the fixation of the observation plate, making the observation port closely fit with the observation plate, and improving the heat preservation performance of the test cover; at the same time, the opened observation port also facilitates observing the stretching state of the EVA film sample during the stretching process, which can ensure the heat preservation performance of the test cover and facilitate observing the situation inside the test cover.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. Before clamping the EVA film sample, first make the test cover in a contracted state. At this time, both the upper and lower clamps are located above the test cover, and the test cover does not block them. Therefore, it is convenient to observe the distance between the upper and lower clamps, and move the crossbeam up and down according to the length of the sample to adjust the gauge length between the upper clamp and the lower clamp. Then measure the distance between the two with a ruler. Since there is no obstruction, it is convenient to adjust while observing, improving the test efficiency; after clamping the EVA film sample between the upper and lower clamps, the top of the test cover can be fixed on the crossbeam through the connection component. At this time, both the upper and lower clamps are located inside the test cover, and then heat or cool the inside of the test cover through the heater and the air conditioning unit, thereby providing a high or low temperature environment for the tensile test. Start the driving motor, the driving motor drives the driving lead screw to rotate, the driving lead screw drives the crossbeam to slide upward, and the crossbeam drives the upper clamp to slide upward, thereby stretching the EVA film sample. During the stretching process, the crossbeam drives the test cover to expand, so as to be applicable to samples with different stretching lengths and expand the application range of the high and low temperature tensile testing machine; 2. When adjusting the distance, first use the switching part to disconnect the driving of the driving motor to the driving lead screw. At this time, the driving lead screw is converted from the electric driving mode to the manual driving mode. Then rotate the distance adjusting handwheel, the distance adjusting handwheel drives the rotating shaft to rotate, the rotating shaft drives the driving lead screw to rotate through the bevel gear set, the driving lead screw drives the crossbeam to slide up and down, thereby driving the upper clamp to slide. The pointer on the upper clamp indicates the indicating scale on the observation plate. The tester can slowly rotate the distance adjusting handwheel while observing the scale. When the pointer indicates the height that needs to be adjusted, stop rotating the distance adjusting handwheel, thereby completing the adjustment of the gauge length between the upper and lower clamps, making the distance adjustment more accurate and easier to control; 3. When installing and disassembling the test cover, only need to press the support frame upward twice to realize the installation and removal of the support frame, thereby realizing the installation and disassembly of the test cover. The operation is simple and convenient; at the same time, the tester can choose to install or disassemble the test cover according to the test requirements. When conducting the test at normal temperature, the test cover can be removed to facilitate observation and operation; when conducting the test in high and low temperature environments, the test cover can be installed, thereby facilitating the provision of high and low temperature environments and improving the application range and convenience of the tensile test device. Description of the Drawings

[0026] Figure 1 is the front view of the overall structure of the embodiment of the present application; Figure 2 is the front view of a partial structure of the embodiment of the present application, mainly used to show the driving component and the distance adjusting component; Figure 3 is the sectional view of a partial structure of the embodiment of the present application, mainly used to show the connecting component; Figure 4 is the left view of a partial structure of the embodiment of the present application, mainly used to show the guiding channel.

[0027] Explanation of reference numerals: 11, base; 12, column; 13, cross beam; 131, fixed groove; 132, sliding groove; 14, upper clamp; 15, lower clamp; 2, driving component; 21, driving motor; 22, driving lead screw; 23, support plate; 24, guiding rod; 25, mounting plate; 26, rotating pulley; 27, driving pulley; 3, distance adjusting component; 31, switching piece; 311, air cylinder; 312, clamping block; 313, clamping groove; 314, fixed pulley; 321, distance adjusting hand wheel; 322, rotating shaft; 323, bevel gear set; 33, observation plate; 34, spring pin; 341, spring hanging ring; 342, limiting plate; 351, indicating scale; 352, pointer; 4, test cover; 41, support frame; 42, observation port; 5, connecting component; 51, slider; 52, spring; 53, positioning rod; 54, sliding column; 55, guiding channel; 551, inner guiding surface; 5511, first guiding inclined surface; 5512, second limiting arc surface; 552, outer guiding surface; 5521, first limiting arc surface; 5522, second guiding inclined surface; 5523, third guiding inclined surface; 5524, pausing surface; 56, push rod; 57, clamping rod; 571, first clamping rod; 572, second clamping rod; 573, hook; 574, clamping pin; 58, guiding plate; 581, limiting groove; 591, pushing block; 592, hanging rod; 6, fixed box. Detailed implementation manners

[0028] The following further describes the present application in detail with reference to the attached Figures 1-4 drawings.

[0029] The embodiment of the present application discloses an EVA film tensile test device.

[0030] Refer to Figure 1 and Figure 2, An EVA film tensile test device includes a base 11. Two vertical columns 12 are provided on the base 11. A cross beam 13 is vertically slidably connected between the two columns 12. An upper clamp 14 is installed on the bottom surface of the cross beam 13, and a lower clamp 15 is fixedly connected to the base 11. A driving component 2 is arranged between the two columns 12 for driving the cross beam 13 to move up and down, thereby driving the upper clamp 14 to move up and down. A distance adjusting component 3 is also provided on the column 12. The distance adjusting component 3 is used to adjust the distance between the upper clamp 14 and the lower clamp 15 before stretching the EVA film sample. A test cover 4 is arranged between the cross beam 13 and the base 11. The test cover 4 can be telescoped up and down. The bottom of the test cover 4 is communicated with a heater and an air conditioner unit through a pipeline for providing a high temperature or low temperature environment. The bottom of the test cover 4 is fixedly connected to the base 11, and a connecting component 5 is arranged at the top. When only tensile testing is required at room temperature, the test cover 4 is in a contracted state and placed on the base 11; when tensile testing is required at different temperatures, the test cover 4 is stretched and installed under the cross beam 13 through the connecting component 5, so that both the upper clamp 14 and the lower clamp 15 are located inside the test cover 4. During the stretching process, the test cover 4 can slide up together with the upper clamp 14, so as to adapt to tensile testing of different sample lengths.

[0031] Refer to Figure 1 and Figure 2 , The driving component 2 includes a driving motor 21 and a driving lead screw 22. A support plate 23 is fixedly connected between the tops of the two columns 12. The driving lead screw 22 is rotatably connected between the base 11 and the support plate 23 and is located inside one of the columns 12. The axis of the driving lead screw 22 is vertically arranged, and one end of the cross beam 13 is threadedly connected to the driving lead screw 22. A guide rod 24 is arranged inside the other column 12. The axis of the guide rod 24 is vertically arranged and is fixedly connected between the base 11 and the support plate 23. The guide rod 24 passes through the other end of the cross beam 13 to guide the cross beam 13. The top of the support plate 23 is fixedly connected with a mounting plate 25. The driving motor 21 is fixedly connected to the mounting plate 25. The top of the driving lead screw 22 extends out of the support plate 23 and is coaxially fixedly connected with a rotating pulley 26. The rotating shaft of the driving motor 21 is arranged downward and is coaxially fixedly connected with a driving pulley 27. The width of the driving pulley 27 is greater than the width of the rotating pulley 26. The driving pulley 27 and the rotating pulley 26 are connected by a belt. When stretching the EVA film sample, the driving motor 21 drives the driving lead screw 22 to rotate through the belt, and the driving lead screw 22 drives the cross beam 13 to slide vertically, thereby driving the upper clamp 14 to slide in a direction away from the lower clamp 15 to perform tensile testing on the EVA film.

[0032] Refer to Figure 1 and Figure 2, the distance adjustment component 3 includes a switching member 31, a distance adjustment handwheel 321 and an observation plate 33. The switching member 31 is arranged on the support plate 23 and is used to disconnect the driving of the driving screw 22 by the driving motor 21. The bottom of the driving screw 22 is rotationally connected to a rotating shaft 322 through a bevel gear set 323. The axial direction of the rotating shaft 322 is perpendicular to the axial direction of the driving screw 22 and extends out of the column 12. The distance adjustment handwheel 321 is coaxially and fixedly connected to the rotating shaft 322. The observation plate 33 is located between the two columns 12 and is hinged to one of the columns 12 and connected to the other column 12 through a spring pin 34. The observation plate 33 is made of high-temperature resistant glass material. The observation plate 33 is arranged on one side of the front of the column 12. A scale 351 is vertically marked on the side of the observation plate 33 away from the cross beam 13. The zero scale line of the scale 351 is aligned with the middle position of the lower clamp 15. A pointer 352 is fixedly connected to the middle position of the upper clamp 14. The pointer 352 is horizontally arranged and is used to point to the scale 351.

[0033] Before clamping the EVA film sample, it is necessary to adjust the gauge length between the upper and lower clamps according to the length of the stretched sample. First, use the switching member 31 to disconnect the driving of the driving screw 22 by the driving motor 21, and then rotate the distance adjustment handwheel 321. The distance adjustment handwheel 321 drives the rotating shaft 322 to rotate. The rotating shaft 322 drives the driving screw 22 to rotate through the bevel gear set 323. At this time, the driving screw 22 is converted from an electric drive mode to a manual drive mode. The driving screw 22 drives the cross beam 13 to slide up and down, thereby driving the upper clamp 14 to slide. The pointer 352 on the upper clamp 14 indicates the scale 351 on the observation plate 33. The tester can slowly rotate the distance adjustment handwheel 321 while observing the scale. When the pointer 352 indicates the height that needs to be adjusted, stop rotating the distance adjustment handwheel 321, thereby completing the adjustment of the gauge length between the upper and lower clamps.

[0034] Refer to Figure 1, the switching member 31 includes a cylinder 311 and a clamping block 312. A fixed pulley 314 is rotatably connected to the bottom surface of the mounting plate 25. The fixed pulley 314 is located above the rotating pulley 26 and is coaxially arranged with the rotating pulley 26. The diameter of the fixed pulley 314 is the same as that of the rotating pulley 26. A clamping groove 313 is formed in the clamping block 312, and the belt is located in the clamping groove 313. The cylinder 311 is fixedly connected to the mounting plate 25 and the telescopic shaft of the cylinder 311 is arranged downward. The telescopic shaft of the cylinder 311 is fixedly connected to the clamping block 312, and the cylinder 311 is used to drive the clamping block 312 to move up and down. When stretching, the cylinder 311 extends to drive the belt to move downward to the rotating pulley 26 through the clamping block 312, so that the driving motor 21 can drive the driving lead screw. When adjusting the distance, the cylinder 311 contracts to drive the belt to move upward to the fixed pulley 314 through the clamping block 312. At this time, the driving lead screw can be rotated by rotating the distance adjusting handwheel 321. Through the switching member 31, the driving mode of the driving lead screw 22 can be changed from electric to manual, making it easier for the operator to control when adjusting the distance between the upper and lower jigs, and at the same time facilitating observation and operation, improving the accuracy of distance adjustment.

[0035] Refer to Figure 1 , the spring pin 34 includes a spring hanging ring 341 and a limiting plate 342. The spring hanging ring 341 is connected to the observation plate 33 by bolts, and the limiting plate 342 is connected to the column 12 by bolts. When fixing the observation plate 33, the spring hanging ring 341 is stretched and then hung on the limiting plate 342 to complete the fixing of the observation plate 33.

[0036] Refer to Figure 2 , support frames 41 are fixedly connected to both the top and bottom surfaces of the test cover 4. The support frame 41 on the bottom surface of the test cover 4 is fixedly connected to the base 11, and the support frame 41 on the top surface of the test cover 4 can be connected to the cross beam 13 through the connection assembly 5. An observation port 42 is vertically opened on one side of the test cover 4 facing the observation plate 33, and the observation port 42 is used to observe the stretching state of the EVA film sample. The test cover 4 is set to be foldable to achieve expansion and contraction, and the test cover 4 is made of high-temperature resistant and fireproof cloth material.

[0037] Refer to Figure 2 、 Figure 3 and Figure 4, the connecting components 5 are arranged in two groups. The two groups of connecting components 5 are symmetrically arranged and located between the driving lead screw 22 and the guide rod 24. Fixed grooves 131 are vertically formed at both ends of the top surface of the cross beam 13, and the two groups of connecting components 5 are respectively located in the two fixed grooves 131. A fixed box 6 is fixedly connected to the top surface of the cross beam 13. The bottom surface of the fixed box 6 is open, and the fixed box 6 communicates with the fixed groove 131. The two groups of connecting components 5 are both arranged in the fixed box 6 and located at both ends of the fixed box 6. The connecting component 5 includes a slider 51. The slider 51 is vertically slidably connected in the fixed box 6 and the fixed groove 131. The top of the slider 51 is fixedly connected to the top surface of the inner wall of the fixed box 6 through a spring 52. A positioning rod 53 is hinged to the top surface of the inner wall of the fixed box 6. The bottom end of the positioning rod 53 is rotatably connected to a sliding column 54. A guiding channel 55 is formed on one side of the slider 51 close to the positioning rod 53. The sliding column 54 at the bottom of the positioning rod 53 is slidably connected in the guiding channel 55. A push rod 56 is fixedly connected to the bottom surface of the slider 51. Only when the push rod 56 is pushed in the direction close to the spring 52 can the sliding column 54 be driven to slide in the guiding channel 55. Also due to the action of the spring 52, the sliding column 54 can be clamped in the guiding channel 55.

[0038] Refer to Figure 4 , the width of the guiding channel 55 is greater than the diameter of the sliding column 54. The guiding channel 55 includes an inner guiding surface 551 and an outer guiding surface 552. A channel for the sliding column 54 to slide is formed between the inner guiding surface 551 and the outer guiding surface 552. Both the inner guiding surface 551 and the outer guiding surface 552 are arranged in a rhombus shape. A first limiting arc surface 5521 is formed at the top of the outer guiding surface 552. A first guiding inclined surface 5511 is formed at the top of the inner guiding surface 551. The first guiding inclined surface 5511 is located directly below the first limiting arc surface 5521. The bottom of the inner guiding surface 551 is bent upward to form a second limiting arc surface 5512. The bottom of the outer guiding surface 552 is bent in the direction close to the second limiting arc surface 5512 and forms a second guiding inclined surface 5522 and a third guiding inclined surface 5523. The third guiding inclined surface 5523 is located directly below the second limiting arc surface 5512. The second guiding inclined surface 5522 is deviated from the center of the second limiting arc surface 5512 in the vertical direction. A pause surface 5524 is provided between the second guiding inclined surface 5522 and the outer guiding surface 552.

[0039] Refer to Figure 3 and Figure 4When the push rod 56 is not pushed, the spring 52 is in a telescopic state, and the slide column 54 is engaged with the first limit arc surface 5521; when the push rod 56 is pushed upward, the slide column 54 is separated from the first limit arc surface 5521 and slides along the first guide inclined surface 5511. When the slide column 54 slides to abut against the stop surface 5524, the push rod 56 is released. Due to the elastic force of the spring 52, the slider 51 moves downward. At this time, due to the guidance of the second guide inclined surface 5522, the slide column 54 automatically slides to the second limit arc surface 5521. When the slider 51 needs to be unlocked, the push rod 56 is pushed again, the slider 51 slides upward, the slide column 54 abuts against the third guide slope 5523 and slides along the third guide slope 5523. During this period, due to the elastic force of the spring 52, the slider 51 slides downward. When the slider 51 slides to the point where the slide column 54 is engaged with the first limiting arc surface 5521, the push rod 56 is released, the positioning rod 53 is locked, that is, the slider 51 is locked, and the slider 51 is reset.

[0040] Reference Figure 3 A clamping rod 57 is provided in the fixed box 6, and the clamping rod 57 includes a first clamping rod 571 and a second clamping rod 572. The second clamping rod 572 is fixedly connected to the top of the first clamping rod 571, and the top of the first clamping rod 571 is rotatably connected to the fixed box 6. The slider 51 is fixedly connected to the guide plate 58 on the side away from the positioning rod 53. The guide plate 58 is set to be U-shaped, and the second clamping rod 572 is rotatably connected to the guide plate 58. A clamping pin 574 is fixedly connected to the second clamping rod 572. Limiting slots 581 are vertically provided on both sides of the guide plate 58. The slider 51 slides up and down to drive the guide plate 58 to slide up and down. When the slider 51 slides upward until the bottom wall of the limiting groove 581 abuts against the locking pin 574, the slider 51 continues to slide upward, which can drive the second locking rod 572 to rotate, thereby driving the bottom of the first locking rod 571 to rotate toward the push rod 56; when the slider 51 slides downward until the top wall of the limiting groove 581 abuts against the locking pin 574, the slider 51 continues to slide downward, which can drive the second locking rod 572 to rotate, thereby driving the bottom of the first locking rod 571 to rotate away from the push rod 56.

[0041] Reference Figure 3 and Figure 4, a hook 573 is fixedly connected to the bottom of the first clamping rod 571. At both ends of the support frame 41 at the top of the test cover 4, two sets of connecting components 5 are respectively and fixedly connected with push blocks 591. A hanging rod 592 is fixedly connected to the side of one push block 591 facing the other push block 591. The two hanging rods 592 are respectively used for hanging on the two hooks 573. A chute 132 is vertically opened on the bottom surface of the cross beam 13 for the support frame 41 to slide. Horizontally, the hanging rod 592 is located between the corresponding push rod 56 and the hook 573. When it is necessary to hang the test cover 4 on the cross beam 13, the support frame 41 at the top of the test box is pulled into the chute 132. The push block 591 pushes the push rod 56 upward, and the push rod 56 pushes the slider 51 upward. At this time, the sliding column 54 on the positioning rod 53 slides downward in the guiding channel 55. When it slides to the second guiding inclined surface 5522, there is a sense of pause. At this time, the support frame 41 is released. Under the action of the spring 52, the sliding column 54 slides into the first limiting arc surface 5521, locking the slider 51. At the same time, the guiding plate 58 also pushes the bottom of the clamping rod 57 to rotate in the direction close to the hanging rod 592, so that the hook 573 catches the hanging rod 592, thus hanging the support frame 41 on the cross beam 13, enabling the test cover 4 to slide upward along with the cross beam 13, and the test cover 4 is stretched accordingly, so as to be applicable to the tensile test of samples with different lengths.

[0042] When it is necessary to remove the support frame 41, the support frame 41 is pushed upward. The push block 591 pushes the push rod 56 upward, and the push rod 56 pushes the slider 51 upward, causing the sliding column 54 to disengage from the second limiting arc surface 5512. At this time, due to the guiding action of the third guiding inclined surface 5523 and the elastic force of the spring 52, when the support frame 41 is released, the sliding column 54 automatically slides into the first limiting arc surface 5521, driving the slider 51 to slide downward. The slider 51 drives the guiding plate 58 to slide downward, and the guiding plate 58 pushes the clamping rod 57 to rotate, moving its bottom away from the hanging rod 592, so that the hook 573 disengages from the hanging rod 592, and the support frame 41 can be removed, causing the test cover 4 to contract and fold, thus facilitating the disassembly of the test cover 4.

[0043] The implementation principle of an EVA film tensile test device according to an embodiment of the present application is as follows: Before performing a tensile test on an EVA film sample, it is necessary to first adjust the gauge length between the upper and lower clamps according to the length of the stretched sample. When adjusting the distance, first start the cylinder 311 to contract the cylinder 311. The cylinder 311 drives the belt upward through the clamping block 312 to the fixed pulley 314, and changes the electric drive of the driving lead screw 22 to the manual mode. At this time, rotate the distance adjustment handwheel 321. The distance adjustment handwheel 321 drives the rotating shaft 322 to rotate. The rotating shaft 322 drives the driving lead screw 22 to rotate through the bevel gear set 323. The driving lead screw 22 drives the cross beam 13 to slide up and down, thereby driving the upper clamp 14 to slide. The pointer 352 on the upper clamp 14 indicates the indication scale 351 on the observation board 33. The tester can slowly rotate the distance adjustment handwheel 321 while observing the scale. When the pointer 352 indicates the height that needs to be adjusted, stop rotating the distance adjustment handwheel 321, thereby completing the adjustment of the gauge length between the upper and lower clamps.

[0044] Then start the cylinder 311 to extend the cylinder 311. The cylinder 311 drives the belt downward through the clamping block 312 to the rotating pulley 26. At this time, the driving lead screw 22 switches from the manual mode to the electric mode. Open the observation board 33 and clamp the EVA film sample between the upper and lower clamps. At this time, if only a tensile test at room temperature is required, the test can be started immediately. The drive motor 21 drives the driving lead screw 22 to rotate. The driving lead screw 22 drives the cross beam 13 to slide upward. The cross beam 13 drives the upper clamp 14 to slide upward, thereby performing a tensile test on the sample.

[0045] When a tensile test needs to be performed in a high-temperature or low-temperature environment, the support frame 41 at the top of the test hood 4 is mounted on the cross beam 13 through the connection assembly 5. Close the observation board 33. The opening of the test hood 4 fits with the observation board 33, so that the test hood 4 is closed. Both the upper and lower clamps are located inside the test hood 4. Then heat or cool the inside of the test hood 4 through the heater and the air conditioning unit, thereby providing a high-temperature or low-temperature environment for the tensile test. When performing the tensile test, the test hood 4 can extend as the cross beam 13 moves upward, so as to be applicable to samples with different tensile lengths.

[0046] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. An EVA film tensile test device, comprising a base (11), two columns (12) are arranged on the base (11), a lower clamp (15) is installed on the base (11), a cross beam (13) is slidably connected up and down between the two columns (12), an upper clamp (14) is installed on the bottom surface of the cross beam (13), and further comprising a heater and an air conditioning unit, which are respectively used to provide a high temperature environment and a low temperature environment for the test, and is characterized in that: It includes a driving motor (21) and a driving lead screw (22). A support plate (23) is provided between the tops of the two columns (12). The driving lead screw (22) is rotatably connected between the base (11) and the support plate (23) and is located inside one column (12). The driving lead screw (22) is used to drive the cross beam (13) to slide up and down. The driving motor (21) is used to drive the driving lead screw (22) to rotate. A test cover (4) is provided on the base (11). The test cover (4) is located below the cross beam (13). A connecting component (5) is provided at the bottom of the cross beam (13). The test cover (4) is telescopic. The top of the test cover (4) is detachably connected to the cross beam (13) through the connecting component (5). The test cover (4) is made of high-temperature resistant and fireproof cloth. The test cover (4) is communicated with a heater and an air-conditioning unit through a pipeline.

2. The EVA film tensile strength testing device according to claim 1, characterized in that: An observation plate (33) is hinged between the two columns (12). The observation plate (33) is made of high-temperature resistant glass. An indicating scale (351) is vertically marked on the observation plate (33). A pointer (352) is horizontally and fixedly connected to the middle of the upper clamp (14). The zero scale line of the indicating scale (351) is aligned with the middle position of the lower clamp (15).

3. An EVA film tensile strength testing device according to claim 2, characterized in that: The bottom of the driving lead screw (22) is rotatably connected to a rotating shaft (322) through a bevel gear set (323). The other end of the rotating shaft (322) is fixedly connected to an adjusting handwheel (321). A switching member (31) is provided on the support plate (23). The switching member (31) is used to disconnect the drive of the driving motor (21) for the driving lead screw (22).

4. An EVA film tensile strength testing device according to claim 3, characterized in that: A rotating pulley (26) is coaxially and fixedly connected to the top of the driving lead screw (22). A driving pulley (27) is coaxially and fixedly connected to the rotating shaft of the driving motor (21). The driving pulley (27) and the rotating pulley (26) are connected by a belt. The width of the driving pulley (27) is greater than the width of the rotating pulley (26). The switching member (31) includes a cylinder (311) and a clamping block (312). An installation plate (25) is also fixedly connected to the support plate (23). The bottom surface of the installation plate (25) is rotatably connected to a fixed pulley (314). The fixed pulley (314) is located above the rotating pulley (26) and is coaxially arranged with the rotating pulley (26). The diameter of the fixed pulley (314) is the same as the diameter of the rotating pulley (26). The telescopic shaft of the cylinder (311) is fixedly connected to the clamping block (312). The clamping block (312) is used to clamp the belt.

5. The EVA film tensile strength testing device according to claim 1, wherein: Support frames (41) are fixedly connected to both the top and the bottom of the test cover (4). The support frame (41) at the bottom of the test cover (4) is fixedly connected to the base (11). A hanging rod (592) is provided on the support frame (41) at the top of the test cover (4). The connecting component (5) includes a hook (573). The hanging rod (592) is used to be hung on the hook (573).

6. The EVA film tensile strength testing device according to claim 5, characterized in that: A fixing groove (131) is provided on the crossbeam (13), the connecting assembly (5) is located in the fixing groove (131), a fixing box (6) is provided on the top of the crossbeam (13), the bottom surface of the fixing box (6) is open, the connecting assembly (5) includes a clamping rod (57), the clamping rod (57) includes a first clamping rod (571) and a second clamping rod (572), the second clamping rod (572) is fixedly connected to the top of the first clamping rod (571), the top of the first clamping rod (571) is rotatably connected to the fixing box (6), the hook (573) is fixedly connected to the bottom of the first clamping rod (571), a slider (51) is vertically slidably connected in the fixing box (6), and the slider (51) is used to drive the second clamping rod (572) to rotate.

7. An EVA film tensile strength testing device according to claim 6, characterized in that: The top of the slider (51) is fixedly connected to the top surface of the fixed box (6) through a spring (52). A positioning rod (53) is rotatably connected in the fixed box (6). The positioning rod (53) is located on the side of the slider (51) away from the clamping rod (57). A guide channel (55) is provided on the side of the slider (51) facing the positioning rod (53). The bottom of the positioning rod (53) is rotatably connected to a sliding column (54). The sliding column (54) is slidably connected in the guide channel (55). A first limiting arc surface (5521) is provided at the top of the guide channel (55), and a second limiting arc surface (5512) is provided at the bottom of the guide channel (55). The first limiting arc surface (5521) and the second limiting arc surface (5512) are provided. The two limiting arc surfaces (5512) are both used to fix the sliding column (54), the bottom surface of the slider (51) is fixedly connected to a push rod (56), the support frame (41) is fixedly connected to a push block (591), the hanging rod (592) is fixedly connected to the push block (591), the slider (51) is fixedly connected to a guide plate (58) on the side facing the clamping rod (57), a limiting groove (581) is vertically provided in the guide plate (58), the second clamping rod (572) is fixedly connected to a clamping pin (574), the clamping pin (574) is located in the limiting groove (581), and when the slider (51) slides vertically, the limiting groove (581) is slidably connected to the clamping pin (574).

8. An EVA film tensile strength testing device according to claim 7, characterized in that: The width of the guiding channel (55) is greater than the diameter of the sliding post (54). The guiding channel (55) includes an inner guiding surface (551) and an outer guiding surface (552). A channel for the sliding post (54) to slide is formed between the inner guiding surface (551) and the outer guiding surface (552). Both the inner guiding surface (551) and the outer guiding surface (552) are arranged in a rhombus shape. The first limiting arc surface (5521) is located at the top of the outer guiding surface (552). A first guiding inclined surface (5511) is formed at the top of the inner guiding surface (551), and the first guiding inclined surface (5511) is located directly below the first limiting arc surface (5521). The second limiting arc surface (5512) is formed by bending the bottom of the inner guiding surface (551) upward. The bottom of the outer guiding surface (552) bends towards the second limiting arc surface (5512) and forms a second guiding inclined surface (5522) and a third guiding inclined surface (5523). The third guiding inclined surface (5523) is located directly below the second limiting arc surface (5512). The second guiding inclined surface (5522) is vertically offset from the center of the second limiting arc surface (5512). A pause surface (5524) is provided between the second guiding inclined surface (5522) and the outer guiding surface (552).

9. The EVA film tensile strength testing device according to claim 2, wherein: The observation plate (33) and one of the upright columns (12) are connected by a spring pin (34). The spring pin (34) includes a spring hanging ring (341) and a limiting plate (342). The spring hanging ring (341) is arranged on the observation plate (33), and the limiting plate (342) is arranged on the upright column (12). The spring hanging ring (341) is used to be hung on the limiting plate (342). An observation port (42) is vertically formed on one side of the test cover (4) facing the observation plate (33), and the observation port (42) is used to observe the tensile state of the EVA film sample.

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