Bending test device and testing method for detecting bending resistance of composite materials

Abstract

The present invention discloses a bending test device and a test method for detecting the bending resistance of composite materials, which relates to the technical field of test devices and solves the problem of low efficiency of placing samples one by one and the need to use measuring equipment to measure the lengths of both ends of the samples when placing the samples. A bending test device for detecting the bending resistance of composite materials comprises a test device body, and a sample placement table is installed on the outer surface of the test device body. The present invention can place multiple samples on a sample automatic replacement mechanism. During the use of the device, the sample that has been tested can be automatically replaced by the sample automatic replacement mechanism, and the position of the sample can be automatically positioned by the sample automatic positioning mechanism during the replacement process. The above technical solution increases the detection efficiency, detection accuracy and convenience of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of testing devices, and in particular to a bending testing device and a testing method for detecting the bending resistance of composite materials. Background Art

[0002] The matrix materials of composite materials are divided into two categories: metal and non-metal. Commonly used metal matrices include aluminum, magnesium, copper, titanium and their alloys. Non-metal matrices mainly include synthetic resins, rubber, ceramics, graphite, carbon, etc., and reinforcing materials mainly include glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, whiskers, and metals. In the process of developing new composite materials, in order to obtain their various values, it is necessary to use a variety of different equipment to conduct different tests on them. For example, when testing the bending resistance of composite materials, it is necessary to use a material bending mechanical properties machine to test them. This material bending mechanical properties machine can also be called a bending test device for testing the bending resistance of composite materials.

[0003] However, existing bending test devices for bending resistance have the problem that during the test, the specimen will deform, resulting in differences in the force-bearing surface, which in turn affects the test operation and test results. Patent number CN204988904U, which is named as a device for testing the bending performance of plate materials, solves the above problem by controlling the fixture spacing and force-bearing surface by rotating the support surface to improve its accuracy.

[0004] However, when using this new bending test device for anti-bending performance, samples can only be placed on the device one by one, and the detection efficiency is relatively low. When placing the sample on the device, it is necessary to use a vernier caliper or other measuring device to measure the length of both sides of the sample to ensure that the center point of the bottom end of the sample can be aligned with the center point of the upper end surface of the sample placement table. This placement method is not only inefficient but also has low accuracy. Therefore, it does not meet the existing needs. In this regard, we propose a bending test device and test method for detecting the anti-bending performance of composite materials. Summary of the Invention

[0005] The purpose of the present invention is to provide a bending test device and a testing method for detecting the bending resistance of composite materials, so as to solve the problems raised in the above background technology. However, when using this new bending test device for bending resistance, samples can only be placed on the device one by one, and the detection efficiency is relatively low. When the sample is placed on the device, a vernier caliper or other measuring device is needed to measure the length of both sides of the sample to ensure that the center point of the bottom end of the sample can be aligned with the center point of the upper end surface of the sample placement table. This placement method is not only inefficient but also has low accuracy.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solution: a bending test device for detecting the bending resistance of composite materials, comprising a test device body, a sample placement table mounted on the outer surface of the test device body, a downward pressure head mounted above the sample placement table, an automatic sample replacement mechanism mounted behind the sample placement table, and an automatic sample positioning mechanism fixedly mounted at each of the four end corners of the upper end surface of the automatic sample replacement mechanism;

[0007] The automatic sample replacement mechanism includes a driving mechanism, a rack transmission mechanism, and four sample placement boxes, each of which has a sample placed inside. The driving mechanism can move the four sample placement boxes in turn between the sample placement platform and the lower pressure head so that the bottom end of the sample inside the sample placement box between the sample placement platform and the lower pressure head is in contact with the upper end surface of the sample placement platform.

[0008] The four automatic sample positioning mechanisms each include a transmission mechanism and two positioning clamps. The two positioning clamps on the same automatic sample positioning mechanism are inserted into both sides of the same sample placement box. When the sample placement box moves to one side of the sample placement table, the transmission mechanism on the automatic sample positioning mechanism closest to the sample placement box will be connected to the rack transmission mechanism to push the two positioning clamps inward at the same time.

[0009] Preferably, the driving mechanism includes a cylindrical metal shell, a stepper motor, a circular turntable, an inclined rectangular groove, an inclined plate, a transmission shaft, an inclined fixing groove, a storage groove, an inclined fixing block, a fixing spring and a connecting rod. The cylindrical metal shell is fixed to one side of the test device body, and a stepper motor is installed on one side inside the cylindrical metal shell. The output shaft of the stepper motor is connected to the transmission shaft through a coupling.

[0010] Preferably, a bevel fixing groove is provided at each of the four end corners of the outer surface of the transmission shaft, a receiving groove corresponding to the position of the bevel fixing groove is provided inside the cylindrical metal shell, a bevel fixing block is provided inside the receiving groove, the surface of the bevel fixing block facing the bevel fixing groove is inserted into the interior of the bevel fixing groove, and a fixing spring is connected between the bevel fixing block and the inner wall of the receiving groove.

[0011] Preferably, a circular turntable is fixedly provided on the upper end surface of the transmission shaft, a sample placement box is provided at each of the four end corners on the outer side of the circular turntable, a square through hole is provided on the lower end surface of the sample placement box, two connecting rods are symmetrically provided on both sides between the sample placement box and the circular turntable, the connecting rods are connected to the circular turntable through a rotating shaft, and the surface of the connecting rod facing the sample placement box is fixed to the sample placement box.

[0012] Preferably, an inclined panel is provided between the sample placement table and the circular turntable, and both sides of the upper end surface of the inclined panel are inclined surfaces. An inclined rectangular groove is provided on the surface of the sample placement box facing the circular turntable, and the shape of the inclined rectangular groove matches the shape of the top end of the inclined panel. The top end of the inclined panel is inserted into the inside of the inclined rectangular groove on the outer surface of the sample placement box located above it.

[0013] Preferably, the rack transmission mechanism includes a lower rack and an upper rack, the lower rack is located on the upper side of the surface of the inclined plate facing the circular turntable, an upper rack is provided below the lower rack, only the front half of the lower end surface of the lower rack is provided with a tooth head, and only the rear half of the upper end surface of the upper rack is provided with a tooth head.

[0014] Preferably, the four transmission mechanisms each include an arc-shaped metal shell, a gear transmission shaft, a bevel gear A, a bevel gear B, a shaft, a bevel gear A, a spur gear A, a screw transmission shaft, a screw, an internal threaded sleeve, a hemispherical fixed groove, a metal ball, a spring and a transmission gear. The four gear transmission shafts are respectively located at the four end corners of the outer surface of the circular turntable, and the outer surface fixed sleeve of the gear transmission shaft located outside the circular turntable is provided with a transmission gear. The transmission gear closest to the inclined panel is located between the lower rack and the upper rack, and the tooth head of the transmission gear matches the tooth grooves on the lower rack and the upper rack at the same time.

[0015] Preferably, one end of the gear transmission shaft is inserted into the interior of the circular turntable, and the top of the gear transmission shaft inserted into the interior of the circular turntable is provided with a bevel gear A, and the bevel gear A is meshed with a bevel gear B. The axis of the bevel gear B is connected to a shaft, and the top of the shaft is inserted into the interior of the arc-shaped metal shell, and the top of the shaft inserted into the interior of the arc-shaped metal shell is provided with a bevel gear A, and the bevel gear A is meshed with a bevel gear B. The axis of the bevel gear B is fixed with a short shaft, and a spur gear B is fixed on one side of the bevel gear B and located on the outer surface of the short shaft, and one side of the spur gear B is meshed with a spur gear A, and two screw transmission shafts are symmetrically fixedly connected on both sides of the spur gear A, and a screw is provided on the outer side of the screw transmission shaft, and one side of the outer surface of the screw is provided with an internal threaded sleeve connected to its thread, and the surface of the positioning clamp facing the internal threaded sleeve is fixed to the internal threaded sleeve.

[0016] Preferably, a plurality of metal balls are provided at the four end corners of the outer surface of the screw drive shaft, the inner wall of the screw is evenly provided with hemispherical fixing grooves corresponding to the positions of the metal balls, and the metal balls are stuck in the interior of the hemispherical fixing grooves, and a spring is connected to one side of the outer surface of the metal ball.

[0017] A method for operating a bending test device for testing the bending resistance of composite materials includes the following steps: step A: placing a sample in each of four sample placement trays, then starting a stepper motor. The stepper motor drives a transmission shaft connected to the stepper motor to rotate. When the transmission shaft rotates, a circular turntable located at the top of the stepper motor also rotates. When the circular turntable rotates, the sample placement tray connected to the circular turntable via a connecting rod also rotates. When one of the sample placement trays moves to one side of an inclined plate and contacts it, and the stepper motor continues to rotate, the sample placement tray is pushed upward. As the sample placement tray is pushed upward, the top end of the inclined plate is inserted into an inclined rectangular groove on the outer surface of the sample placement tray. During the insertion process, the sample placement tray itself descends. As the sample placement tray descends, the bottom end of the sample located therein contacts the upper end surface of the sample placement tray.

[0018] Step B: As the transmission shaft rotates, the inclined fixing blocks stuck in the inclined fixing grooves on the outer surface of the transmission shaft will be pushed outward. In the process of being pushed outward, the inclined fixing blocks will compress the fixing springs. Since the interval angle between each inclined fixing groove is 90 degrees, every time the transmission shaft rotates 90 degrees, the four inclined fixing blocks will be respectively stuck in the interior of the inclined fixing grooves different from the original ones, thereby fixing the transmission shaft;

[0019] Step C: When the circular turntable rotates clockwise, the transmission gear on the outside will also move. When the transmission gear moves to one side of the lower rack and the circular turntable continues to rotate, the transmission gear will mesh with the lower rack and rotate clockwise with the rotation of the circular turntable. When the transmission gear rotates, it drives the bevel gear A to rotate. The bevel gear A drives the bevel gear B and the bevel gear A to rotate. The bevel gear A drives the bevel gear B and the spur gear B (518) to rotate. The spur gear B drives the spur gear A. The screw drive shaft rotates synchronously with the spur gear A. Because the metal ball of the screw drive shaft is stuck in the hemispherical fixing groove of the screw, the screw and the screw drive shaft rotate synchronously. The rotating shaft rotates synchronously. When the screw rotates, the internal threaded sleeve, which is sleeved on the outer surface of the screw and is threadedly connected to it but cannot rotate by itself, will move inward on the outer surface of the screw. As the screw moves, the positioning clamp fixed to it will also move inward. When the two positioning clamps inside the same sample placement box move inward at the same time, the position of the sample between them will be automatically adjusted, so that the center point of the bottom surface of the sample will be aligned with the center point of the top of the sample placement table. When the transmission gear passes through the lower rack, it will engage with the upper rack, thereby driving the rotating shaft to rotate counterclockwise. When the rotating shaft rotates counterclockwise, the two positioning clamps will move outward at the same time, thereby releasing the positioning of the sample.

[0020] Step D: When both ends of the positioning clamp are in contact with the sample, but the screw drive shaft for driving the screw to rotate is still rotating, a plurality of hemispherical fixing grooves are provided on the inner wall of the screw, and a plurality of metal balls connected to the spring but stuck in the hemispherical fixing grooves are provided on the outer surface of the screw drive shaft. The screw drive shaft drives the screw to rotate by the metal balls stuck in the hemispherical fixing grooves. When the positioning clamp can no longer move inward, but the screw drive shaft is still rotating, the metal balls will be pushed inward, thereby squeezing the spring. At this time, the rotating screw drive shaft will not drive the screw to continue rotating.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention provides a sample placement box at each of the four corners of the outer side of the circular turntable. When placing samples, one sample can be placed in each of the four sample placement boxes. After the device is used to test the samples, the sample automatic replacement mechanism can automatically replace the samples. During the testing process, the tested samples can be taken out and new samples can be placed in. The above technical solution improves the testing efficiency of the device.

[0023] 2. In the process of changing samples, the two positioning clamps will automatically move inward to support the sample located between them, so that the middle point of the lower end surface of the positioning clamp can be aligned with the center point of the upper end surface of the sample placement table. The above technical solution increases the convenience of the equipment and its detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a partial internal view of the overall structure of the automatic sample replacement mechanism of the present invention;

[0026] Figure 3 For the present invention Figure 2 Side view of the internal structure at A in the middle;

[0027] Figure 4 It is a side view of the automatic sample replacement mechanism of the present invention;

[0028] Figure 5 A side view of the automatic sample replacement mechanism of the present invention without the cylindrical metal housing and the circular turntable;

[0029] Figure 6 For the present invention Figure 4 Side view of the internal structure at B in the middle;

[0030] Figure 7 For the present invention Figure 6Top view of the internal structure at C in the middle;

[0031] Figure 8 For the present invention Figure 7 Side view of the internal structure at D in the middle.

[0032] Figure: 1, test device body; 2, sample placement table; 3, lower pressure head; 4, sample automatic replacement mechanism; 401, cylindrical metal housing; 402, stepping motor; 403, circular turntable; 404, sample placement box; 405, inclined rectangular slot; 406, inclined plate; 407, lower rack; 408, upper rack; 409, transmission shaft; 410, inclined fixing slot; 411, storage slot; 412, inclined fixing block; 413, fixing spring; 414, connecting rod; 5, sample Automatic positioning mechanism; 501, arc-shaped metal housing; 502, gear transmission shaft; 503, bevel gear A; 504, bevel gear B; 505, shaft; 506, bevel gear A; 507, spur gear A; 508, screw transmission shaft; 509, screw; 510, internal threaded sleeve; 511, positioning clamp; 512, hemispherical fixing groove; 513, metal ball; 514, spring; 515, transmission gear; 516, short shaft; 517, bevel gear B; 518, spur gear B. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0034] See also Figures 1 to 6 The present invention provides an embodiment of a bending test device for detecting the bending resistance of composite materials, comprising a test device body 1, a sample placement table 2 is installed on the outer surface of the test device body 1, a downward pressure head 3 is provided above the sample placement table 2, and an automatic sample replacement mechanism 4 is provided behind the sample placement table 2. An automatic sample positioning mechanism 5 is fixedly installed at each of the four end corners of the upper end surface of the automatic sample replacement mechanism 4;

[0035] The automatic sample replacement mechanism 4 includes a drive mechanism, a rack transmission mechanism, and four sample placement boxes 404. Each sample placement box 404 contains a sample. The drive mechanism can move the four sample placement boxes 404 in turn between the sample placement platform 2 and the lower pressure head 3 so that the bottom end of the sample inside the sample placement box 404 located between the sample placement platform 2 and the lower pressure head 3 is in contact with the upper end surface of the sample placement platform 2.

[0036] Each of the four automatic sample positioning mechanisms 5 includes a transmission mechanism and two positioning clamps 511. The two positioning clamps 511 on the same automatic sample positioning mechanism 5 are inserted into the two sides of the same sample placement box 404. When the sample placement box 404 moves to one side of the sample placement table 2, the transmission mechanism on the automatic sample positioning mechanism 5 closest to the sample placement box 404 will be connected to the rack transmission mechanism, thereby pushing the two positioning clamps 511 inward at the same time.

[0037] Furthermore, the driving mechanism includes a cylindrical metal shell 401, a stepper motor 402, a circular turntable 403, an inclined rectangular groove 405, an inclined plate 406, a transmission shaft 409, an inclined fixing groove 410, a receiving groove 411, an inclined fixing block 412, a fixing spring 413 and a connecting rod 414. The cylindrical metal shell 401 is fixed to one side of the test device body 1. The stepper motor 402 is installed on one side of the inner part of the cylindrical metal shell 401. The output shaft of the stepper motor 402 is connected to the transmission shaft 409 through a coupling; the outer part of the transmission shaft 409 is connected to the transmission shaft 409. The four corners of the surface are each provided with an inclined fixing groove 410, and the interior of the cylindrical metal shell 401 is provided with a receiving groove 411 corresponding to the position of the inclined fixing groove 410, and the interior of the receiving groove 411 is provided with an inclined fixing block 412, and the surface of the inclined fixing block 412 facing the inclined fixing groove 410 is inserted into the interior of the inclined fixing groove 410, and a fixing spring 413 is connected between the inclined fixing block 412 and the inner wall of the receiving groove 411; the upper end surface of the transmission shaft 409 is fixed with a circular turntable 403, and the four end corners of the outer side of the circular turntable 403 are each provided with a The sample placement box 404 has a square through hole on its lower end surface. Two connecting rods 414 are symmetrically provided on both sides between the sample placement box 404 and the circular turntable 403. The connecting rods 414 and the circular turntable 403 are connected by a rotating shaft. The surface of the connecting rods 414 facing the sample placement box 404 is fixed to the sample placement box 404. An inclined plate 406 is provided between the sample placement table 2 and the circular turntable 403. Both sides of the upper end surface of the inclined plate 406 are inclined surfaces. The surface of the sample placement box 404 facing the circular turntable 403 is provided with an inclined plate. The top of the inclined plate 406 is inserted into the inclined rectangular groove 405 on the outer surface of the sample placement box 404. The rack transmission mechanism includes a lower rack 407 and an upper rack 408. The lower rack 407 is located on the upper side of the inclined plate 406 facing the circular turntable 403. The upper rack 408 is provided below the lower rack 407. Only the front half of the lower end surface of the lower rack 407 is provided with a tooth head, and only the rear half of the upper end surface of the upper rack 408 is provided with a tooth head.

[0038] Working principle: When in use, check the use of each mechanism, move the device to the working area, connect the power supply, place a sample in each of the four sample placement boxes 404, and then start the stepper motor 402. The stepper motor 402 can drive the transmission shaft 409 connected to it to rotate. When the transmission shaft 409 rotates, the circular turntable 403 at its top will also rotate. When the circular turntable 403 rotates, the sample placement box 404 connected to the circular turntable 403 through the connecting rod 414 will also rotate. When one of them is turned off, the sample placement box 404 will rotate. As the sample tray 404 moves to one side of the inclined plate 406 and contacts it, and as the stepper motor 402 continues to rotate, the sample tray 404 is pushed upward. As the sample tray 404 moves upward, the top end of the inclined plate 406 is inserted into the inclined rectangular groove 405 on the outer surface of the sample tray 404. During the insertion process, the sample tray 404 itself descends. As the sample tray 404 descends, the bottom end of the sample inside it contacts the upper end surface of the sample placement table 2.

[0039] During the rotation of the transmission shaft 409, the inclined fixing block 412 stuck in the inclined fixing groove 410 on the outer surface of the transmission shaft 409 will be pushed outward. During the process of being pushed outward, the inclined fixing block 412 will squeeze the fixing spring 413. Since the interval angle between each inclined fixing groove 410 is ninety degrees, every time the transmission shaft 409 rotates ninety degrees, the four inclined fixing blocks 412 will be respectively stuck in the inside of the inclined fixing groove 410 different from the original one, thereby fixing the transmission shaft 409. Through the above technical solution, the inclined plate 406 can be accurately stuck in the inside of the inclined rectangular groove 405, thereby increasing the accuracy of the sample automatic replacement mechanism 4.

[0040] Furthermore, the four transmission mechanisms each include an arc-shaped metal housing 501, a gear transmission shaft 502, a bevel gear A503, a bevel gear B504, a shaft 505, a bevel gear A506, a spur gear A507, a screw transmission shaft 508, a screw 509, an internal threaded sleeve 510, a hemispherical fixing groove 512, a metal ball 513, a spring 514 and a transmission gear 515. The four gear transmission shafts 502 are respectively located at the four end corners of the outer surface of the circular turntable 403, and the outer surface of the gear transmission shaft 502 located outside the circular turntable 403 is A transmission gear 515 is provided on the surface fixed sleeve. The transmission gear 515 closest to the inclined plate 406 is located between the lower rack 407 and the upper rack 408, and the tooth head of the transmission gear 515 matches the tooth grooves on the lower rack 407 and the upper rack 408. One end of the gear transmission shaft 502 is inserted into the interior of the circular turntable 403. The top of the gear transmission shaft 502 inserted into the interior of the circular turntable 403 is provided with a bevel gear A503. The bevel gear A503 is meshed with the bevel gear B504. The axis of the bevel gear B504 is connected to the shaft 505. The top of the rotating shaft 505 is inserted into the interior of the arc-shaped metal shell 501. The top of the rotating shaft 505 inserted into the interior of the arc-shaped metal shell 501 is provided with a bevel gear A506. The bevel gear A506 is meshed with a bevel gear B517. The axis of the bevel gear B517 is fixed with a short rotating shaft 516. A spur gear B518 is fixed on one side of the bevel gear B517 and located on the outer surface of the short rotating shaft 516. A spur gear A507 is meshed on one side of the spur gear B518. Two screw transmission rotating shafts 508 are symmetrically fixedly connected on both sides of the spur gear A507. The screw transmission A screw 509 is provided on the outside of the rotating shaft 508. An internally threaded sleeve 510 is sleeved on one side of the outer surface of the screw 509 and is threadably connected to the screw 509. The surface of the positioning clamp 511 facing the internally threaded sleeve 510 is fixed to the internally threaded sleeve 510. A plurality of metal balls 513 are provided at the four end corners of the outer surface of the screw transmission rotating shaft 508. The inner wall of the screw 509 is evenly provided with hemispherical fixing grooves 512 corresponding to the positions of the metal balls 513. The metal balls 513 are snapped into the interior of the hemispherical fixing grooves 512. A spring 514 is connected to one side of the outer surface of the metal balls 513.

[0041] When the circular turntable 403 rotates clockwise, the transmission gear 515 on the outside will also move. When the transmission gear 515 moves to one side of the lower rack 407 and the circular turntable 403 continues to rotate, the transmission gear 515 will mesh with the lower rack 407 and rotate clockwise with the rotation of the circular turntable 403. When the transmission gear 515 rotates, it drives the bevel gear A503 to rotate. The bevel gear A503 drives the bevel gear B504 and the bevel gear A506 to rotate. The bevel gear A506 drives the bevel gear B517 and the spur gear B518 to rotate. The spur gear B519 rotates. 518 drives the spur gear A507, and the screw drive shaft 508 rotates synchronously with the spur gear A507. Because the metal ball 513 of the screw drive shaft 508 is stuck in the hemispherical fixing groove 512 of the screw 509, the screw 509 and the screw drive shaft 508 rotate synchronously. When the screw 509 rotates, the internal thread sleeve 510, which is sleeved on the outer surface of the screw 509 and is connected to it by thread but cannot rotate by itself, will move inward on the outer surface of the screw 509. As the screw 509 moves, the positioning clamp 511 fixed to it will also move inward. When the two positioning clamps located inside the same sample placement box 404 are When the clamps 511 move inward at the same time, the position of the sample between them will be automatically adjusted, so that the center point of the bottom surface of the sample will be aligned with the center point of the top of the sample placement table 2. When the transmission gear 515 passes through the lower rack 407, it will mesh with the upper rack 408, thereby driving the shaft 505 to rotate counterclockwise. When the shaft 505 rotates counterclockwise, the two positioning clamps 511 will move outward at the same time, thereby releasing the positioning of the sample. When both ends of the positioning clamp 511 are in contact with the sample, but the screw transmission shaft 508 for driving the screw 509 to rotate continues to rotate, the inner wall of the screw 509 is provided with multiple hemispherical The fixing groove 512 is provided with a plurality of metal balls 513 connected to the spring 514 but inserted into the hemispherical fixing groove 512 on the outer surface of the screw drive shaft 508. The screw drive shaft 508 drives the screw 509 to rotate by inserting the metal balls 513 into the hemispherical fixing groove 512. When the positioning clamp 511 can no longer move inward, but the screw drive shaft 508 is still rotating, the metal balls 513 will be pushed inward, thereby squeezing the spring 514. At this time, the rotating screw drive shaft 508 will not drive the screw 509 to continue rotating. The above technical solution increases the convenience of the equipment and its detection accuracy.

[0042] An operating method of a bending test device for detecting the bending resistance of a composite material comprises the following steps:

[0043] Step A: Place a sample in each of the four sample trays 404. Then, start the stepper motor 402. The stepper motor 402 drives the drive shaft 409 connected thereto to rotate. When the drive shaft 409 rotates, the circular turntable 403 located on its top also rotates. When the circular turntable 403 rotates, the sample trays 404 connected to the circular turntable 403 via the connecting rod 414 also rotate. When one of the sample trays 404 moves to one side of the inclined plate 406 and contacts it, and the stepper motor 402 continues to rotate, the sample tray 404 is pushed upward. As the sample tray 404 is pushed upward, the top end of the inclined plate 406 is inserted into the inclined rectangular groove 405 located on the outer surface of the sample tray 404. During the insertion process, the sample tray 404 itself descends. As the sample tray 404 descends, the bottom end of the sample inside it contacts the upper end surface of the sample tray 2.

[0044] Step B: During the rotation of the transmission shaft 409, the inclined fixing block 412 stuck in the inclined fixing groove 410 on the outer surface of the transmission shaft 409 will be pushed outward. During the process of being pushed outward, the inclined fixing block 412 will compress the fixing spring 413. Since the interval angle between each inclined fixing groove 410 is 90 degrees, every time the transmission shaft 409 rotates 90 degrees, the four inclined fixing blocks 412 will be respectively stuck in the interior of the inclined fixing groove 410 different from the original one, thereby fixing the transmission shaft 409;

[0045] Step C: When the circular turntable 403 rotates clockwise, the transmission gear 515 located on the outside will also move accordingly. When the transmission gear 515 moves to one side of the lower rack 407 and the circular turntable 403 continues to rotate, the transmission gear 515 will mesh with the lower rack 407 and as the circular turntable 403 rotates, the transmission gear 515 itself will also rotate clockwise. When the transmission gear 515 rotates, it drives the bevel gear A503 to rotate. The bevel gear A503 drives the bevel gear B504 and the bevel gear A506 to rotate. The bevel gear A506 drives the bevel gear B517 and the spur gear B518 to rotate. The spur gear B518 drives the spur gear A507. The screw drive shaft 508 rotates synchronously with the spur gear A507. Because the metal ball 513 of the screw drive shaft 508 is stuck in the hemispherical fixing groove 512 of the screw 509 When the screw 509 rotates, the internal threaded sleeve 510, which is threadedly connected to the outer surface of the screw 509 but cannot rotate by itself, will move inward on the outer surface of the screw 509. As the screw 509 moves, the positioning clamp 511 fixed to it will also move inward. When the two positioning clamps 511 inside the same sample placement box 404 move inward at the same time, the position of the sample between them will be automatically adjusted, so that the center point of the bottom surface of the sample is aligned with the center point of the top of the sample placement table 2. When the transmission gear 515 passes through the lower rack 407, it will mesh with the upper rack 408, thereby driving the rotating shaft 505 to rotate counterclockwise. When the rotating shaft 505 rotates counterclockwise, the two positioning clamps 511 will move outward at the same time, thereby releasing the positioning of the sample.

[0046] Step D: When both ends of the positioning clamp 511 are in contact with the sample, but the screw drive shaft 508 for driving the screw 509 to rotate is still rotating, a plurality of hemispherical fixing grooves 512 are provided on the inner wall of the screw 509, and a plurality of metal balls 513 connected to the spring 514 but inserted into the hemispherical fixing grooves 512 are provided on the outer surface of the screw drive shaft 508. The screw drive shaft 508 drives the screw 509 to rotate by inserting the metal balls 513 into the hemispherical fixing grooves 512. When the positioning clamp 511 can no longer move inward, but the screw drive shaft 508 is still rotating, the metal balls 513 will be pushed inward, thereby squeezing the spring 514. At this time, the rotating screw drive shaft 508 will not drive the screw 509 to continue rotating.

[0047] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A bending test device for detecting the bending resistance of composite materials, comprising a test device body (1), characterized in that: A sample placement platform (2) is installed on the outer surface of the test device body (1), a downward pressure head (3) is provided above the sample placement platform (2), and an automatic sample replacement mechanism (4) is provided behind the sample placement platform (2), and a sample automatic positioning mechanism (5) is fixedly installed at each of the four end corners of the upper end surface of the automatic sample replacement mechanism (4); The automatic sample replacement mechanism (4) includes a driving mechanism, a rack transmission mechanism, and four sample placement boxes (404), each of which has a sample placed inside. The driving mechanism can move the four sample placement boxes (404) in turn between the sample placement platform (2) and the lower pressure head (3) so that the bottom end of the sample inside the sample placement box (404) between the sample placement platform (2) and the lower pressure head (3) fits with the upper end surface of the sample placement platform (2); The four automatic sample positioning mechanisms (5) each include a transmission mechanism and two positioning clamps (511). The two positioning clamps (511) on the same automatic sample positioning mechanism (5) are inserted into both sides of the interior of the same sample placement box (404). When the sample placement box (404) moves to one side of the sample placement platform (2), the transmission mechanism on the automatic sample positioning mechanism (5) closest to the sample placement box (404) is connected to the rack transmission mechanism, thereby pushing the two positioning clamps (511) inward at the same time. The four transmission mechanisms each include an arc-shaped metal housing (501), a gear transmission shaft (502), a bevel gear A (503), a bevel gear B (504), a shaft (505), a bevel gear A (506), a spur gear A (507), a screw transmission shaft (508), a screw (509), an internal thread sleeve (510), a hemispherical fixing groove (512), a metal ball (513), a spring (514) and a transmission gear (515). The four gear transmission mechanisms each include an arc-shaped metal housing (501), a gear transmission shaft (502), a bevel gear A (503), a bevel gear B (504), a shaft (505), a bevel gear A (506), a spur gear A (507), a screw transmission shaft (508), a screw (509), an internal thread sleeve (510), a hemispherical fixing groove (512), a metal ball (513), a spring (514) and a transmission gear (515). The rotating shaft (502) is respectively located at the four end corners of the outer surface of the circular turntable (403), and the outer surface of the gear transmission rotating shaft (502) located outside the circular turntable (403) is fixedly sleeved with a transmission gear (515), the transmission gear (515) closest to the inclined plate (406) is located between the lower rack (407) and the upper rack (408), and the tooth head of the transmission gear (515) is matched with the tooth grooves on the lower rack (407) and the upper rack (408); One end of the gear transmission shaft (502) is inserted into the interior of the circular turntable (403), and the top of the gear transmission shaft (502) inserted into the interior of the circular turntable (403) is provided with a bevel gear A (503), and the bevel gear A (503) is meshed with a bevel gear B (504), and the axis of the bevel gear B (504) is connected to a shaft (505), and the top of the shaft (505) is inserted into the interior of the arc-shaped metal shell (501), and the top of the shaft (505) inserted into the interior of the arc-shaped metal shell (501) is provided with a bevel gear A (506), and the bevel gear A (506) is meshed with a bevel gear B (517), and the bevel gear B (517) is connected to the shaft of the bevel gear B (517). 7) is fixedly provided with a short rotating shaft (516) at the axis center, a spur gear B (518) is fixedly provided on one side of the bevel gear B (517) and on the outer surface of the short rotating shaft (516), a spur gear A (507) is meshed with one side of the spur gear B (518), two screw transmission rotating shafts (508) are symmetrically fixedly connected on both sides of the spur gear A (507), a screw (509) is provided on the outer side of the screw transmission rotating shaft (508), an internal thread sleeve (510) connected to the screw (509) is sleeved on one side of the outer surface of the screw (509), and a surface of the positioning clamp (511) facing the internal thread sleeve (510) is fixed to the internal thread sleeve (510).

2. A bending test device for detecting the bending resistance of composite materials according to claim 1, characterized in that: The driving mechanism comprises a cylindrical metal shell (401), a stepping motor (402), a circular turntable (403), an inclined rectangular groove (405), an inclined plate (406), a transmission shaft (409), an inclined fixing groove (410), a receiving groove (411), an inclined fixing block (412), a fixing spring (413) and a connecting rod (414); the cylindrical metal shell (401) is fixed to one side of the test device body (1); a stepping motor (402) is installed on one side inside the cylindrical metal shell (401); and an output shaft of the stepping motor (402) is connected to the transmission shaft (409) via a coupling.

3. A bending test device for detecting the bending resistance of composite materials according to claim 2, characterized in that: Each of the four end corners of the outer surface of the transmission shaft (409) is provided with an inclined surface fixing groove (410); the interior of the cylindrical metal shell (401) is provided with a receiving groove (411) corresponding to the position of the inclined surface fixing groove (410); the interior of the receiving groove (411) is provided with an inclined surface fixing block (412); the surface of the inclined surface fixing block (412) facing the inclined surface fixing groove (410) is inserted into the interior of the inclined surface fixing groove (410); and a fixing spring (413) is connected between the inclined surface fixing block (412) and the inner wall of the receiving groove (411).

4. A bending test device for detecting the bending resistance of composite materials according to claim 3, characterized in that: A circular turntable (403) is fixedly provided on the upper end face of the transmission shaft (409), and a sample placement box (404) is provided at each of the four end corners on the outer side of the circular turntable (403). A square through hole is provided on the lower end face of the sample placement box (404), and two connecting rods (414) are symmetrically provided on both sides between the sample placement box (404) and the circular turntable (403). The connecting rods (414) and the circular turntable (403) are connected via a rotating shaft, and the surface of the connecting rod (414) facing the sample placement box (404) is fixed to the sample placement box (404).

5. The bending test device for detecting the bending resistance of composite materials according to claim 4, characterized in that: An inclined panel (406) is provided between the sample placement table (2) and the circular turntable (403), and both sides of the upper end surface of the inclined panel (406) are inclined surfaces. The surface of the sample placement box (404) facing the circular turntable (403) is provided with an inclined rectangular groove (405), and the shape of the inclined rectangular groove (405) matches the shape of the top end of the inclined panel (406). The top end of the inclined panel (406) is inserted into the interior of the inclined rectangular groove (405) on the outer surface of the sample placement box (404) located above it.

6. The bending test device for detecting the bending resistance of composite materials according to claim 5, characterized in that: The rack transmission mechanism includes a lower rack (407) and an upper rack (408), wherein the lower rack (407) is located on the upper side of the surface of the inclined plate (406) facing the circular turntable (403), and an upper rack (408) is provided below the lower rack (407). Only the front half of the lower end surface of the lower rack (407) is provided with a tooth head, and only the rear half of the upper end surface of the upper rack (408) is provided with a tooth head.

7. The bending test device for detecting the bending resistance of composite materials according to claim 6, characterized in that: A plurality of metal balls (513) are provided at the four end corners of the outer surface of the screw transmission shaft (508), and the inner wall of the screw (509) is evenly provided with hemispherical fixing grooves (512) corresponding to the positions of the metal balls (513), and the metal balls (513) are inserted into the interior of the hemispherical fixing grooves (512), and a spring (514) is connected to one side of the outer surface of the metal ball (513).

8. An operating method of the bending test device for detecting the bending resistance of composite materials according to claim 7, characterized in that: Here are the steps: Step A: Place a sample in each of the four sample placement boxes (404), then start the stepper motor (402), which can drive the transmission shaft (409) connected thereto to rotate. When the transmission shaft (409) rotates, the circular turntable (403) located at the top thereof will also rotate. When the circular turntable (403) rotates, the sample placement box (404) connected to the circular turntable (403) via the connecting rod (414) will also rotate. When one of the sample placement boxes (404) moves to the inclined plate ( When one side of the sample placement box (406) contacts the other and the stepping motor (402) continues to rotate, the sample placement box (404) will be pushed upward. As the sample placement box (404) is pushed upward, the top of the inclined plate (406) will be inserted into the inclined rectangular groove (405) on the outer surface of the sample placement box (404). During the insertion process, the sample placement box (404) itself will descend. As the sample placement box (404) descends, the bottom end of the sample inside it will contact the upper end surface of the sample placement table (2); Step B: When the transmission shaft (409) rotates, the inclined surface fixing block (412) stuck in the inclined surface fixing groove (410) on the outer surface of the transmission shaft (409) will be pushed outward. When the inclined surface fixing block (412) is pushed outward, it will press the fixing spring (413). Since the interval angle between each inclined surface fixing groove (410) is 90 degrees, every time the transmission shaft (409) rotates 90 degrees, the four inclined surface fixing blocks (412) will be respectively stuck in the interior of the inclined surface fixing groove (410) different from the original one, thereby fixing the transmission shaft (409); Step C: When the circular turntable (403) rotates clockwise, the transmission gear (515) located on the outside will also move. When the transmission gear (515) moves to one side of the lower rack (407) and the circular turntable (403) continues to rotate, the transmission gear (515) will mesh with the lower rack (407) and as the circular turntable (403) rotates, the transmission gear (515) itself will also rotate clockwise. When the transmission gear (515) rotates, it drives the umbrella-shaped Gear A (503) rotates, bevel gear A (503) drives bevel gear B (504) and bevel gear A (506) to rotate, bevel gear A (506) drives bevel gear B (517) and spur gear B (518) to rotate, spur gear B (518) drives spur gear A (507), screw drive shaft (508) rotates synchronously with spur gear A (507), because the metal ball (513) of the screw drive shaft (508) is stuck in the hemispherical ball of the screw (509), The screw (509) and the screw drive shaft (508) rotate synchronously in the fixing groove (512). When the screw (509) rotates, the internal thread sleeve (510) which is sleeved on the outer surface of the screw (509) and is connected to the screw with a thread but cannot rotate by itself will move inward on the outer surface of the screw (509). As the screw (509) moves, the positioning clamp (511) fixed to it will also move inward. When two screws are located inside the same sample placement box (404), When the positioning clamps (511) move inward at the same time, the position of the sample between the two will be automatically adjusted, so that the center point of the bottom surface of the sample is aligned with the center point of the top of the sample placement table (2). When the transmission gear (515) passes through the lower rack (407), it will mesh with the upper rack (408), thereby driving the rotating shaft (505) to rotate counterclockwise. When the rotating shaft (505) rotates counterclockwise, the two positioning clamps (511) will move outward at the same time, thereby releasing the positioning of the sample. Step D: When both ends of the positioning clamp (511) are in contact with the sample, but the screw drive shaft (508) for driving the screw (509) to rotate is still rotating, a plurality of hemispherical fixing grooves (512) are provided on the inner wall of the screw (509), and a plurality of metal balls (513) connected to the spring (514) but inserted into the hemispherical fixing grooves (512) are provided on the outer surface of the screw drive shaft (508). The screw drive shaft (508) drives the screw (509) to rotate by inserting the metal balls (513) into the hemispherical fixing grooves (512). When the positioning clamp (511) can no longer move inward, but the screw drive shaft (508) is still rotating, the metal balls (513) will be pushed inward, thereby squeezing the spring (514). At this time, the rotating screw drive shaft (508) will not drive the screw (509) to continue rotating.

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