A tensile testing apparatus

Abstract

The application relates to the technical field of mechanical property testing, in particular to a tension test equipment which comprises a vertical fixed stand column, a fixed seat is fixedly connected to the top of the stand column, a plurality of straight grooves are arranged in the fixed seat, and a sliding block is slidably arranged in the straight groove; a shell is fixed on the top of the sliding block, a sliding hole is vertically arranged on the top of the shell, and the sliding hole is used for accommodating a supporting rod to slide in and out of the shell; and a scraper is fixed on the top of the shell through a connecting structure, and the cutting edge of the scraper abuts against the surface of the supporting rod. The supporting rod distributed on the fixed seat in a circumferential direction is subjected to centrifugal motion, the closed loop wire belt is subjected to a stretching test, the stress distribution under the annular stress state of the wire belt is simulated, and the accuracy of test data is improved. The scraper forms a scanning track relative to the surface of the supporting rod through the lifting of the supporting rod, and there is no cleaning dead angle. The abrasion debris is prevented from adhering to the surface of the supporting rod, and the test precision of the next time is affected.

Description

Technical Field

[0001] This invention relates to the field of mechanical performance testing technology, and in particular to a tensile testing device. Background Technology

[0002] Cable ties, also known as cable ties, are widely used in electronics, automotive manufacturing, logistics packaging, and other fields, primarily for bundling cables, pipes, or goods. As a common fastener, its mechanical properties, especially tensile strength, are core indicators of product quality. Currently, the industry typically uses universal tensile testing machines to perform tensile tests on cable ties, either by forming the cable ties into a specific shape or by directly pulling on a single point to test its breaking strength.

[0003] However, in practical use, cable ties are typically locked in a closed loop and subjected to circumferential tension. For example, when bundling cables, the cable ties surround the cable bundle and expand outwards under stress. Existing tensile testing machines mostly use a single-point hook-and-pull method, where clamps at both ends directly hook the cable ties for linear tension. This stress distribution method differs significantly from the actual working state of the cable ties and cannot simulate the stress distribution under circumferential stress, resulting in test data that fails to accurately reflect the product's performance in real-world use. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a tensile testing device.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] Design a tensile testing device, including:

[0007] A vertically fixed column has a fixed base at the top. The fixed base has multiple straight slots through which a slider slides.

[0008] The housing is fixed to the top of the slider, and a sliding hole is vertically opened on the top of the housing to accommodate the support rod sliding in and out of the housing;

[0009] And a scraper, which is fixed to the top of the housing by a connecting structure, with the blade of the scraper abutting against the surface of the support rod.

[0010] Preferably, the connection structure includes a stud and a connector. The stud is fixed to the top of the housing, the connector is slidably fitted on the stud, and a nut is threaded onto the stud to lock the connector. The scraper is fixed to the end of the connector.

[0011] Preferably, a turntable is rotatably mounted on the column, and multiple inclined slots are opened through the turntable. A sliding seat is slidably fitted in the inclined slot, and a connecting shaft is rotatably mounted on the sliding seat at its bottom end and on the slider at its top end.

[0012] Preferably, the column is fixed on the base, a hydraulic cylinder is rotatably mounted on the base, a torque arm is fixed to the outer wall of the turntable, and the output shaft of the hydraulic cylinder is hinged to the torque arm.

[0013] Preferably, a nut seat is fixedly connected to the inner wall of the housing, and a reciprocating screw is threaded into the nut seat, with the bottom of the support rod fixedly connected to the top of the reciprocating screw.

[0014] Preferably, an internal spline tube is fixedly connected inside the support rod, and a spline shaft is slidably fitted inside the internal spline tube. The top end of the connecting shaft passes through the slider and is fixedly connected to the bottom end of the spline shaft.

[0015] Preferably, a fixing ring is fixed to the surface of the column, and multiple racks are fixed to the fixing ring. A gear is connected to the middle of the connecting shaft through a one-way bearing, and the gear matches the racks.

[0016] Preferably, an oil inlet is provided on one side of the housing, and a sealing bolt is threaded into the oil inlet. A piston is fixed to the bottom of the reciprocating screw, and flow channels are provided through the reciprocating screw and the piston to allow lubricating oil to circulate between the top and bottom of the housing.

[0017] Preferably, the slider has multiple blind holes inside, and round-headed tumblers slide within the blind holes. The outer wall of the connecting shaft has multiple grooves, and the round-headed tumblers cooperate with the grooves. A spring is provided inside the blind holes to apply a spring force to the round-headed tumblers pointing towards the connecting shaft.

[0018] The tensile testing device proposed in this invention has the following advantages: This device uses a centrifugal motion of a support rod circumferentially distributed on a fixed base to perform a tensile test on a closed-loop cable tie, simulating the stress distribution under annular stress on the cable tie and improving the accuracy of the test data. The raising and lowering of the support rod allows the scraper to form a scanning trajectory relative to the support rod surface, eliminating cleaning dead zones. This prevents wear debris from adhering to the support rod surface and affecting the accuracy of subsequent tests. Attached Figure Description

[0019] Figure 1 This is a structural schematic diagram of a tensile testing device proposed in this invention.

[0020] Figure 2 This is a schematic diagram of the mounting structure of the fixing seat of a tensile testing device proposed in this invention.

[0021] Figure 3This is a schematic diagram of the structure of the turntable of a tensile testing device proposed in this invention.

[0022] Figure 4 This is a schematic diagram of the structure of a fixing seat for a tensile testing device proposed in this invention. Figure 1 .

[0023] Figure 5 This is a schematic diagram of the structure of a fixing seat for a tensile testing device proposed in this invention. Figure 2 .

[0024] Figure 6 This is a schematic diagram of the external structure of the housing of a tensile testing device proposed in this invention.

[0025] Figure 7 This is a schematic diagram of the internal structure of the housing of a tensile testing device proposed in this invention.

[0026] Figure 8 This invention provides a tensile testing device. Figure 7 A schematic diagram of the main view structure.

[0027] Figure 9 This is a schematic diagram of the internal structure of the reciprocating lead screw of a tensile testing device proposed in this invention.

[0028] Figure 10 This invention provides a tensile testing device. Figure 9 Enlarged view of point A in the middle.

[0029] Figure 11 This is a schematic diagram of the internal structure of the spline tube of a tensile testing device proposed in this invention.

[0030] Figure 12 This is a schematic diagram of the sliding hole at the top of the housing of a tensile testing device proposed in this invention.

[0031] In the diagram: 1. Base; 2. Hydraulic cylinder; 3. Turntable; 4. Torque arm; 5. Fixed seat; 6. Column; 7. Sliding seat; 8. Gear; 9. Slider; 10. Connecting shaft; 11. Fixed ring; 12. Rack; 13. Inclined slot; 14. One-way bearing; 15. Straight slot; 16. Housing; 17. Oil inlet; 18. Sealing bolt; 19. Blind hole; 20. Spring; 21. Round-headed ball; 22. Groove; 23. Splined shaft; 24. Piston; 25. Nut seat; 26. Reciprocating screw; 27. Internal spline tube; 28. Flow channel; 29. ​​Support rod; 30. Stud; 31. Connector; 32. Scraper; 33. Nut; 34. Sliding hole. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Reference Figure 1 , Figure 11 and Figure 12 A tensile testing device includes a column 6, a fixed base 5 fixedly connected to the top of the column 6, a plurality of straight slots 15 extending through the fixed base 5, a slider 9 slidably fitted within the straight slots 15, a housing 16 fixedly connected to the top of the slider 9, a sliding hole 34 vertically opened at the top of the housing 16 for accommodating a support rod 29 sliding in and out of the housing 16, a plurality of studs 30 fixedly connected to the top of the housing 16, a connector 31 slidably fitted on the studs 30, a nut 33 threaded on the studs 30 for locking the connector 31, and a scraper 32 fixed to the end of the connector 31, the cutting edge of the scraper 32 abutting against the surface of the support rod 29.

[0034] When conducting a tensile test on the cable tie, the cable tie is locked into a closed loop and subjected to circumferential stretching. The closed loop of the cable tie is fitted onto the support rod 29 surrounding the column 6. Then, the slider 9 in the straight slot 15 simultaneously performs centrifugal motion, causing the support rod 29 to expand synchronously in all directions. During the expansion of the support rod 29, the closed loop of the cable tie is subjected to circumferential stretching until the cable tie breaks, thus completing the tensile test.

[0035] The cable tie is usually made of nylon-based thermoplastic material. During the circumferential stretching process, wear will inevitably occur at the contact point between the cable tie and the support rod 29. In order to prevent impurities generated by wear from adhering to the support rod 29 and affecting the accuracy of the next test, this application moves the connector 31 on the stud 30 so that the cutting edge of the scraper 32 abuts against the surface of the support rod 29. After tightening the nut 33, the contact state between the scraper 32 and the support rod 29 can be maintained. When the support rod 29 slides vertically in and out of the housing 16 in the sliding hole 34, the support rod 29 and the scraper 32 move relative to each other, and the impurities attached to its surface will be scraped off by the scraper 32 to achieve the purpose of cleaning the support rod 29.

[0036] like Figures 2-5 As shown, a turntable 3 is rotatably mounted on the column 6. Multiple inclined slots 13 are opened through the turntable 3. A sliding seat 7 is slidably fitted inside the inclined slots 13. A connecting shaft 10 is rotatably mounted on the sliding seat 7 at its bottom end and on the slider 9 at its top end. The column 6 is fixed on the base 1. A hydraulic cylinder 2 is rotatably mounted on the base 1. A torque arm 4 is fixedly connected to the outer wall of the turntable 3. The output shaft of the hydraulic cylinder 2 is hinged to the torque arm 4.

[0037] The hydraulic cylinder 2 acts as a power source to apply force to the torque arm 4, so that the torque arm 4 drives the turntable 3 to deflect around the column 6. During the deflection of the turntable 3, the inclined slot 13 will force the sliding seat 7 to move. The sliding seat 7 drives the slider 9 to move linearly in the straight slot 15 through the connecting shaft 10, so that the support rod 29 can make centrifugal or centripetal motion to complete the annular tensile test of the cable tie.

[0038] like Figures 6-11 As shown, a nut seat 25 is fixed to the inner wall of the housing 16. A reciprocating screw 26 is threaded into the nut seat 25. The bottom of the support rod 29 is fixed to the top of the reciprocating screw 26. An inner spline tube 27 is fixed inside the support rod 29. A spline shaft 23 is slidably fitted inside the inner spline tube 27. The top of the connecting shaft 10 passes through the slider 9 and is fixed to the bottom of the spline shaft 23. A fixing ring 11 is fixed to the surface of the column 6. Multiple racks 12 are fixed to the fixing ring 11. A gear 8 is connected to the middle of the connecting shaft 10 through a one-way bearing 14. The gear 8 matches the racks 12.

[0039] During movement, the connecting shaft 10 drives the gear 8 to move on the rack 12, and the gear 8 is driven by the rack 12 to rotate, wherein:

[0040] During the centrifugal motion of the strut 29 performing circumferential stretching of the cable tie, the one-way bearing 14 is in an overrunning state, during which the gear 8 idles without driving the connecting shaft 10 to rotate.

[0041] During the centripetal motion reset process after the test of the strut 29, the one-way bearing 14 is in a locked state. At this time, the gear 8 is essentially fixed on the connecting shaft 10. During this process, the gear 8 will drive the connecting shaft 10 to rotate synchronously.

[0042] When the connecting shaft 10 rotates, the splined shaft 23 at its top will drive the support rod 29 and the reciprocating screw 26 to rotate through the inner spline tube 27. The reciprocating screw 26 will make a vertical reciprocating linear motion in the nut seat 25. During the entire stroke of the gear 8 on the rack 12, the reciprocating screw 26 will make a reciprocating linear motion in the nut seat 25, thereby driving the support rod 29 to make a lifting motion. The support rod 29 rotates while lifting, so that the scraper 32 can scan the surface of the support rod 29, thereby enabling the scraper 32 to thoroughly clean the surface of the support rod 29.

[0043] like Figure 9 and Figure 10 As shown, the slider 9 has multiple blind holes 19 inside, and a round-headed ball 21 is slidably fitted inside the blind hole 19. The outer wall of the connecting shaft 10 has multiple grooves 22, and the round-headed ball 21 is fitted into the grooves 22. A spring 20 is provided inside the blind hole 19 to apply a spring force to the round-headed ball 21 pointing towards the connecting shaft 10.

[0044] The round-headed ball 21 abuts against the groove 22 under the elastic force of the spring 20 to apply resistance to the connecting shaft 10, thereby preventing the connecting shaft 10 from rotating due to vibration or during the idle rotation of the gear 8.

[0045] like Figures 6-9 As shown, an oil inlet 17 is provided on one side of the housing 16. A sealing bolt 18 is threaded into the oil inlet 17. A piston 24 is fixed to the bottom of the reciprocating screw 26. A flow channel 28 is provided through the reciprocating screw 26 and the piston 24 to allow the lubricating oil to circulate between the top and bottom of the housing 16.

[0046] Through the oil inlet 17, the test personnel can inject lubricant into the housing 16. When the piston 24 moves downward under the drive of the reciprocating screw 26, the support rod 29 will enter the housing 16 simultaneously. The lubricant at the bottom of the housing 16 will enter the top of the housing 16 through the flow channel 28 under the pressure of the piston 24, coating the surface of the support rod 29 with lubricant, reducing the coefficient of friction between the surface of the support rod 29 and the cable tie, and preventing wear due to excessive friction during the annular stretching of the cable tie. The worn part of the cable tie is very easy to break during the stretching process, causing the cable tie to break under the action of a small tensile force, which affects the accuracy of the test data.

[0047] The working principle is as follows:

[0048] (1) Stretching process: The output shaft of the hydraulic cylinder 2 is hinged to the torque arm 4 outside the turntable 3. The hydraulic cylinder 2 extends and retracts to drive the turntable 3 to deflect and rotate around the column 6.

[0049] The turntable 3 has several inclined slots 13, which fit into the sliding seat 7; when the turntable 3 deflects, the inclined walls of the slots 13 force the sliding seat 7 to move.

[0050] The sliding seat 7 drives the slider 9 to move through the connecting shaft 10, so that it moves linearly in the straight groove 15 of the fixed seat 5, so that the slider 9 makes reciprocating linear motion along the radial direction of the fixed seat 5.

[0051] The slider 9 carries the housing 16 in a centrifugal motion. The upper end of the housing 16 is stretched open by the support rod 29 to perform circumferential stretching.

[0052] During the stretching process, the connecting shaft 10 serves to transmit displacement and support load, and is not required to rotate during the stretching phase.

[0053] The cylinder 2 drives the turntable 3 to rotate. Through the cooperation of the inclined slot 13, sliding seat 7, connecting shaft 10 and slider 9, the angular displacement of the turntable 3 is converted into the radial reciprocating linear motion of the slider 9 on the fixed seat 5, so that the support rod 29 can open and close, and stretch the closed-loop cable strip until it breaks.

[0054] (2) Reset process: The connecting shaft 10 is equipped with a gear 8 through a one-way bearing 14 in the middle. The gear 8 is always meshed with the rack 12. When the slider 9 drives the connecting shaft 10 to return, the one-way bearing 14 is locked. The gear 8 and the connecting shaft 10 are essentially fixedly connected. When the rack 12 forces the gear 8 to rotate, the connecting shaft 10 is forced to rotate around its own axis. The rotation of the connecting shaft 10 is transmitted to the support rod 29 and the reciprocating screw 26 through the spline shaft 23 and the inner spline tube 27.

[0055] When the reciprocating screw 26 rotates, it will perform linear reciprocating motion in the fixed nut seat 25. Because the stroke of the rack 12 is limited, the reciprocating screw 26 will complete one lifting and lowering cycle within the nut seat 25 during the entire stroke of the rack 12.

[0056] The scraper 32 is fixed to the upper end of the housing 16 by the connector 31, stud 30, and nut 33. The scraper 32 is adjusted so that the cutting edge is in contact with the outer circle of the support rod 29.

[0057] The strut 29 moves up and down once driven by the reciprocating screw 26. During the movement, it rotates. The blade of the scraper 32 scans relative to the strut 29, scraping off the wear debris and adhering substances.

[0058] During the return stroke, the gear 8, rack 12 and one-way bearing 14 are used to convert part of the radial retraction stroke into the rotation and lifting motion of the support rod 29, allowing the scraper 32 against the surface of the support rod 29 to perform a scanning scraping. At the same time, the piston 24 delivers lubricating oil to the working section to reduce friction error in the next test.

[0059] One side of the housing 16 has an oil inlet 17, which is controlled by a sealing bolt 18 to inject lubricant into the housing 16. During the descent of the reciprocating screw 26, a piston 24 at its bottom applies pressure downwards, causing lubricant to enter the top of the housing 16 through the flow channels 28 in the reciprocating screw 26 and piston 24, thus lubricating the surface of the support rod 29 that descends into the housing 16. In the next tensile test, the friction between the stretched cable tie and the support rod 29 is more controllable, reducing the risk of premature cable tie breakage due to friction and resulting in lower data.

[0060] This device slides on the stud 30 via the connector 31, allowing the scraper 32 to adjust its cutting edge pressure. During the raising and lowering of the support rod 29, the scraper 32 forms a scanning trajectory relative to the surface of the support rod 29, eliminating cleaning dead zones and preventing wear debris from adhering to the surface of the support rod 29, thus affecting the accuracy of the next batch of tests.

[0061] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A tensile testing device, characterized in that, include: A vertically fixed column (6) is fixed to the top of the column (6) and a fixed seat (5) is fixed to the top of the fixed seat (5). Multiple straight slots (15) are opened through the fixed seat (5) and a slider (9) is slidably fitted inside the straight slots (15). The housing (16) is fixed on the top of the slider (9). A sliding hole (34) is vertically opened on the top of the housing (16) to accommodate the support rod (29) sliding in and out of the housing (16). And a scraper (32), which is fixed to the top of the housing (16) by a connecting structure, with the cutting edge of the scraper (32) abutting against the surface of the support rod (29).

2. The tensile testing equipment according to claim 1, characterized in that, The connection structure includes a stud (30) and a connector (31). The stud (30) is fixed to the top of the housing (16). The connector (31) is slidably fitted on the stud (30). A nut (33) is threaded on the stud (30) to lock the connector (31). The scraper (32) is fixed to the end of the connector (31).

3. The tensile testing equipment according to claim 1, characterized in that, A turntable (3) is rotatably mounted on the column (6). Multiple inclined slots (13) are opened through the turntable (3). A sliding seat (7) is slidably fitted inside the inclined slot (13). A connecting shaft (10) is rotatably mounted on the sliding seat (7) at its bottom end and on the slider (9) at its top end.

4. The tensile testing equipment according to claim 3, characterized in that, The column (6) is fixed on the base (1), and the oil cylinder (2) is rotatably installed on the base (1). A torque arm (4) is fixed on the outer wall of the turntable (3), and the output shaft of the oil cylinder (2) is hinged to the torque arm (4).

5. The tensile testing equipment according to claim 3, characterized in that, A nut seat (25) is fixedly connected to the inner wall of the housing (16), and a reciprocating screw (26) is threaded into the nut seat (25). The bottom of the support rod (29) is fixedly connected to the top of the reciprocating screw (26).

6. The tensile testing equipment according to claim 5, characterized in that, The support rod (29) has an internal spline tube (27) fixedly connected inside, and a spline shaft (23) is slidably fitted inside the internal spline tube (27). The top end of the connecting shaft (10) passes through the slider (9) and is fixedly connected to the bottom end of the spline shaft (23).

7. The tensile testing equipment according to claim 6, characterized in that, A fixing ring (11) is fixedly attached to the surface of the column (6), and a plurality of racks (12) are fixedly attached to the fixing ring (11). A gear (8) is connected to the middle of the connecting shaft (10) through a one-way bearing (14), and the gear (8) matches the rack (12).

8. The tensile testing equipment according to claim 5, characterized in that, The housing (16) has an oil inlet (17) on one side, and a sealing bolt (18) is threaded into the oil inlet (17). A piston (24) is fixed to the bottom of the reciprocating screw (26). A flow channel (28) is opened through the reciprocating screw (26) and the piston (24) to allow the lubricating oil to circulate between the top and bottom of the housing (16).

9. The tensile testing equipment according to claim 3, characterized in that, The slider (9) has multiple blind holes (19) inside, and a round-headed ball (21) is slidably fitted inside the blind hole (19). The outer wall of the connecting shaft (10) has multiple grooves (22), and the round-headed ball (21) is fitted with the groove (22). A spring (20) is provided inside the blind hole (19) to apply a spring force to the round-headed ball (21) pointing towards the connecting shaft (10).

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