Method for detecting tensile strength of copper alloy wire

Abstract

The invention discloses a method for detecting the tensile strength of a copper alloy wire, which comprises the following steps of: 1, selecting a sample: randomly extracting 10-15 coils of wires from a produced copper alloy wire coil material, and eliminating subjective influence by randomly extracting the copper alloy wire coil material, so that the sample has objectivity; therefore, the sample can be uniformly distributed in the whole, the error index of the measured sample is reduced, and the purpose of deducing the overall index by using the sample index is achieved. According to the method for detecting the tensile strength of the copper alloy wire, the sample is cleaned and dried, so that the cleanness and dryness of the sample can be effectively ensured, the accuracy of detection data is ensured, and the contact area between the end part of the sample and the clamping mechanism can be increased by curling the end part of the sample, so that the fixing stability of the sample is ensured; in cooperation with the rotation effect of the clamping mechanism, the sample can be rolled, and the sample is prevented from sliding.

Description

Technical Field

[0001] The invention relates to the technical field of copper alloy wire material detection, and in particular to a method for detecting the tensile strength of a copper alloy wire material. Background Art

[0002] Copper alloy wire is an alloy made of pure copper and one or more other elements, which is stretched and formed. It has good electrical conductivity, wear resistance, ductility and corrosion resistance, and is widely used in various fields. After the production of copper alloy wire is completed, in order to ensure the quality of copper alloy wire, the tensile strength of copper alloy wire needs to be tested.

[0003] In the actual operation of the existing copper alloy wire tensile test, since the diameter of the copper alloy wire is generally small, the common tensile testing machine clamps will slip between the wire and the clamps when clamping the wire for testing, thus affecting the normal progress of the test. To this end, a copper alloy wire tensile strength testing method is proposed to better meet the actual testing needs in response to the above problems. Summary of the invention

[0004] The object of the present invention is to provide a method for detecting the tensile strength of a copper alloy wire to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for detecting the tensile strength of a copper alloy wire, comprising the following steps:

[0006] Step 1: Sample selection: randomly select 10-15 coils of copper alloy wire from the produced copper alloy wire coils. Randomly selecting copper alloy wire coils can eliminate subjective influences and make the samples objective, so that the samples can be evenly distributed in the whole, reducing the error index of the measured samples, so as to achieve the purpose of inferring the overall index with the sample index;

[0007] Step 2: Sample pretreatment: After randomly sampling the copper alloy wire coil, pretreat the sample according to the actual test needs to facilitate subsequent testing;

[0008] Step 3: The sample is clamped and fixed to the tensile machine. During the test, both ends of the pre-treated sample are clamped on the clamping mechanism of the tensile machine, and the length of the sample is greater than the distance between the two clamping mechanisms.

[0009] Step 4: The tensile testing machine is started to perform tensile testing. After the sample is clamped and fixed, the clamping mechanism is driven to move by controlling the driving mechanism to increase the distance between the clamping mechanisms, thereby realizing the detection of the tensile strength of the sample until the sample breaks. With the help of the pressure sensor, the tensile force f borne by the sample when it breaks can be obtained. The total tensile force borne by the sample when it breaks is F=2f.

[0010] Step 5: Calculate the tensile strength according to σ=F / A, and compare the obtained tensile strength of the copper alloy wire with the standard tensile strength σ1. When σ<σ1, the tensile strength of the copper alloy wire is unqualified; when σ≥σ1, the tensile strength of the copper alloy wire is qualified. Based on 10-15 groups of sample test data, it can be determined whether the overall production quality of the copper alloy wire is qualified.

[0011] Preferably, the pretreatment of the sample includes cutting the sample, cleaning and drying the sample, and curling the sample end. For the cutting of the sample, each selected copper alloy wire coil is cut by a cutting machine to ≥1200mm, and when the copper alloy wire coil is cut, 50mm-100mm is first removed from the end of the copper alloy wire coil. By removing the wire at the end of the copper alloy wire coil, the scratches and cracks at the end of the wire can be effectively avoided to affect the accuracy of the detection data.

[0012] Preferably, the cleaning and drying of the sample includes cleaning and drying the sample. For cleaning the sample, copper alloy degreasing and rust removing agent and water are mixed in a ratio of 1:5 to form a cleaning solution, and then the intercepted sample is placed in the cleaning solution, and manually turned over for 2-4 minutes. Through the above operation, the cleaning effect of the sample can be achieved, ensuring that the surface of the sample is clean, and avoiding the presence of oil stains and rust that affect the detection results.

[0013] Preferably, the sample is dried. After the sample is cleaned, water stains are wiped off with a towel, and the sample is dried with a dryer. Through the above operation, the sample can be dried to ensure that the sample is dry for subsequent testing.

[0014] Preferably, the sample end is curled to curl both ends of the copper alloy wire, thereby increasing the area of ​​the copper alloy wire end, facilitating the stability of clamping and fixing between the copper alloy wire and the clamping mechanism, and by curling the sample wire end, the stability of the sample wire clamping is ensured.

[0015] Preferably, the tensile testing machine is started to perform a tensile testing process including sample winding and sample tensile testing. When the sample is winding and performing the tensile testing, the driving mechanism drives the clamping mechanism to move. At this time, the copper alloy wire is in a bent state. When the clamping mechanism moves, the rotating mechanism in conjunction with the linkage can cause the clamping mechanism to wind up the copper alloy wire to ensure that the copper alloy wire is in a straight state. Through the above operations, the copper alloy wire can be straightened and the stability between the copper alloy wire and the clamping mechanism can be ensured by winding the copper alloy wire, thereby further avoiding slippage between the clamping mechanism and the copper alloy wire.

[0016] Preferably, the driving mechanism drives the clamping mechanism to move at a speed of 50 mm / min-100 mm / min. By limiting the moving speed of the clamping mechanism, the accuracy of the detection data can be ensured.

[0017] Preferably, the sample tensile force test can be achieved by driving the clamping mechanism to continue to move after the sample is rolled and straightened, and the tensile force f that the sample is subjected to when it breaks can be obtained in conjunction with the pressure sensor. Through the above operation, the magnitude of the tensile force when the copper alloy wire breaks can be determined, so as to calculate the tensile strength of the copper alloy wire.

[0018] Preferably, the tensile testing machine includes a base, a bracket, a driving mechanism and a clamping mechanism. The bracket is fixed on the base, and the driving mechanism is installed on the bracket. The driving mechanism includes a motor, a bidirectional threaded rod, a transmission gear and a movable plate. The motor is fixed on the bracket, and the output end of the motor is fixed with a bidirectional threaded rod, and the bidirectional threaded rod is symmetrically connected to the base and the bracket through bearings. At the same time, a transmission gear is fixed on the bidirectional threaded rod, and the transmission gears are transmitted through a toothed belt. The bidirectional threaded rod is connected to the movable plate through threads, and a clamping mechanism is installed on the movable plate. Through the above structure, a basic force can be provided for the movement of the clamping mechanism to ensure the normal operation of the device.

[0019] Preferably, the clamping mechanism includes a fixed frame, a vertical rod, a spring, a pressure sensor, a rotating frame, a fixed splint, a first threaded rod, a movable splint, a guide rod, a first gear and a convex gear rod, the fixed frame is arranged on the side of the movable plate, and the fixed frame is fixed with a vertical rod, and the vertical rod and the movable plate are slidably connected, and a spring is fixed between the vertical rod and the pressure sensor, the pressure sensor is fixed on the movable plate, the fixed frame is connected with a rotating frame by a bearing, the rotating frame is fixed with a fixed splint, and the fixed splint is connected with a first threaded rod by a bearing, and the first threaded rod is connected to the movable splint through a thread. At the same time, anti-slip teeth are arranged on the movable splint and the fixed splint, the movable splint and the guide rod are slidably connected, and the guide rod is fixed on the fixed splint, and a first gear is also fixed on the rotating frame, and the first gear and the convex tooth rod are meshingly connected, and the convex tooth rod is fixed between the base and the bracket. During the detection process, the rotating frame, the fixed splint and the movable splint can be rotated through the meshing transmission action between the first gear and the convex tooth rod, so as to realize the winding and straightening effect of the copper alloy wire, and the tensile strength detection effect of the copper alloy wire can be realized by cooperating with the action of the vertical rod, the spring and the pressure sensor.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The tensile strength testing method of the copper alloy wire can effectively ensure the cleanliness and dryness of the sample by washing and drying the sample, thereby ensuring the accuracy of the test data, and by curling the end of the sample, the contact area between the end of the sample and the clamping mechanism can be increased, thereby ensuring the stability of the sample fixation, and the sample can be rolled up with the rotation of the clamping mechanism, which can not only realize the straightening of the sample, but also further ensure the stability between the sample and the clamping mechanism, and avoid the sample from sliding;

[0022] 2. The copper alloy wire tensile strength testing method can achieve clamping and fixing of both ends of the copper alloy wire sample through the fixed clamping plate, the first threaded rod and the movable clamping plate when testing the copper alloy wire. During the testing process, the rotating frame, the fixed clamping plate and the movable clamping plate can be rotated in cooperation with the transmission action between the first gear and the convex gear rod to achieve the winding of the copper alloy wire and ensure that the copper alloy wire is in a straight state. In combination with the action of the vertical rod, the spring and the pressure sensor, the pulling force when the copper alloy wire breaks can be detected, thereby achieving the tensile strength test of the copper alloy wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the detection process of the present invention;

[0024] Figure 2 This is a schematic diagram of the sample pretreatment process of the present invention;

[0025] Figure 3 It is a schematic diagram of the tension detection process of the present invention;

[0026] Figure 4 It is a schematic diagram of the front view of the three-dimensional structure of the tensile machine of the present invention;

[0027] Figure 5 It is a schematic diagram of the front view cross-section three-dimensional structure of the tensile machine of the present invention;

[0028] Figure 6 It is a schematic diagram of the front view of the three-dimensional structure of the clamping mechanism of the present invention;

[0029] Figure 7 It is a bottom-up three-dimensional structural schematic diagram of the clamping mechanism of the present invention.

[0030] In the figure: 1. base; 2. bracket; 3. driving mechanism; 301. motor; 302. bidirectional threaded rod; 303. transmission gear; 304. movable plate; 4. clamping mechanism; 401. fixed frame; 402. vertical rod; 403. spring; 404. pressure sensor; 405. rotating frame; 406. fixed clamping plate; 407. first threaded rod; 408. movable clamping plate; 409. guide rod; 410. first gear; 411. convex tooth rod. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-Figure 7 The present invention provides a technical solution: a method for detecting the tensile strength of a copper alloy wire, comprising the following steps:

[0033] Step 1: Sample selection: 10-15 coils of copper alloy wire are randomly selected from the produced copper alloy wire coils, and the cross-sectional area A of the selected samples is equal. By randomly selecting the copper alloy wire coils, subjective influence can be eliminated, so that the samples are objective, so that the samples can be evenly distributed in the whole, and the error index of the measured samples can be reduced, so as to achieve the purpose of inferring the overall index with the sample index;

[0034] Step 2: Sample pretreatment: After randomly sampling the copper alloy wire coil, pretreat the sample according to the actual test needs to facilitate subsequent testing;

[0035] Step 3: The sample is clamped and fixed to the tensile machine. During the test, both ends of the pre-treated sample are clamped on the clamping mechanism 4 of the tensile machine, and the length of the sample is greater than the distance between the two clamping mechanisms 4;

[0036] Step 4: The tensile testing machine is started to perform tensile testing. After the sample is clamped and fixed, the driving mechanism 3 is controlled to drive the clamping mechanism 4 to move, so that the distance between the clamping mechanisms 4 increases, thereby realizing the detection of the tensile strength of the sample until the sample breaks. With the help of the pressure sensor 404, the tensile force f borne by the sample when it breaks can be obtained. The total tensile force borne by the sample when it breaks is F=2f.

[0037] Step 5: Calculate the tensile strength according to σ=F / A, and compare the obtained tensile strength of the copper alloy wire with the standard tensile strength σ1. When σ<σ1, the tensile strength of the copper alloy wire is unqualified; when σ≥σ1, the tensile strength of the copper alloy wire is qualified. Based on 10-15 groups of sample test data, it can be determined whether the overall production quality of the copper alloy wire is qualified.

[0038] The pretreatment of the samples includes cutting, cleaning and drying of the samples and curling of the sample ends. For cutting of the samples, each selected copper alloy wire coil is cut by a cutting machine to ≥1200mm, and before cutting the copper alloy wire coil, 50mm-100mm is removed from the end of the copper alloy wire coil to avoid scratches and cracks at the end of the wire affecting the accuracy of the test data; the cleaning and drying of the samples includes cleaning and drying of the samples. For cleaning of the samples, copper alloy degreasing and rust removal agent and water are selected with warm water at a temperature of 50℃-60℃ in a ratio of 1:5 to form a cleaning solution, and then the cut samples are placed in the cleaning solution and manually turned over for 2-4min; for drying of the samples, after the sample cleaning is completed, the water stains are wiped off with a towel, and the samples are dried in a dryer; for curling of the sample ends, both ends of the copper alloy wire ends are curled, so as to The area of ​​the end of the copper alloy wire is increased to facilitate the stability of the clamping and fixing between the copper alloy wire and the clamping mechanism 4; the tensile testing process of the tensile machine starting includes the winding and winding of the sample and the tensile testing of the sample. When the sample is wound and wound, the driving mechanism 3 drives the clamping mechanism 4 to move. At this time, the copper alloy wire is in a bent state. When the clamping mechanism 4 moves, the clamping mechanism 4 can be wound with the linkage rotating mechanism to ensure that the copper alloy wire is in a straight state; the driving mechanism 3 drives the clamping mechanism 4 to move at a speed of 50mm / min-100mm / min; the tensile testing of the sample, after the sample is wound and straightened, the driving mechanism 3 drives the clamping mechanism 4 to continue to move to realize the tensile testing of the sample, and the tensile force f borne by the sample when it breaks can be obtained in cooperation with the pressure sensor 404;

[0039] The tensile machine includes a base 1, a bracket 2, a driving mechanism 3 and a clamping mechanism 4. The bracket 2 is fixed on the base 1, and the driving mechanism 3 is installed on the bracket 2. The driving mechanism 3 includes a motor 301, a bidirectional threaded rod 302, a transmission gear 303 and a movable plate 304. The motor 301 is fixed on the bracket 2, and the output end of the motor 301 is fixed with the bidirectional threaded rod 302, and the bidirectional threaded rod 302 is symmetrically connected to the base 1 and the bracket 2 through a bearing. At the same time, the bidirectional threaded rod 302 is fixed with a transmission gear 303, and the transmission gears 303 are transmitted through a toothed belt. The bidirectional threaded rod 302 is connected to the movable plate 304 through threads, and the clamping mechanism 4 is installed on the movable plate 304; the clamping mechanism 4 includes a fixed frame 401, a vertical rod 402, a spring 403, a pressure sensor 404, a rotating frame 405, a fixed clamping plate 406, a first threaded rod 407, a movable clamping plate 408, a guide rod 409, a first gear 410 and a convex gear rod 411 The fixed frame 401 is arranged on the side of the movable plate 304, and a vertical rod 402 is fixed on the fixed frame 401, and the vertical rod 402 and the movable plate 304 are slidably connected, and a spring 403 is fixed between the vertical rod 402 and the pressure sensor 404, and the pressure sensor 404 is fixed on the movable plate 304. The fixed frame 401 is connected to a rotating frame 405 by a bearing, and a fixed clamping plate 406 is fixed on the rotating frame 405, and a first threaded rod is connected to the fixed clamping plate 406 by a bearing. 407, and the first threaded rod 407 is connected to the movable clamping plate 408 through a thread, and the movable clamping plate 408 and the fixed clamping plate 406 are both provided with anti-slip teeth, the movable clamping plate 408 and the guide rod 409 are slidably connected, and the guide rod 409 is fixed on the fixed clamping plate 406, and the first gear 410 is also fixed on the rotating frame 405, and the first gear 410 is meshed with the convex gear rod 411, and the convex gear rod 411 is fixed between the base 1 and the bracket 2;

[0040] When testing copper alloy wire, Figure 1-Figure 7As shown, after the copper alloy wire sample is processed according to step one and step two, the two ends of the copper alloy wire sample are curled. When testing, the end of the copper alloy wire sample is placed between the fixed clamping plate 406 and the movable clamping plate 408, and the first threaded rod 407 is rotated. The movable clamping plate 408 is moved by the threaded connection between the first threaded rod 407 and the movable clamping plate 408. The sliding guide effect between the movable clamping plate 408 and the guide rod 409 can ensure the stability of the movement of the movable clamping plate 408, until the end of the copper alloy wire sample is clamped and fixed by the cooperation of the movable clamping plate 408 and the fixed clamping plate 406. In addition, due to the curling treatment of the end of the copper alloy wire sample, the copper alloy wire sample can be increased. The area between the end of the wire sample and the movable clamping plate 408 and the fixed clamping plate 406, together with the anti-slip structure on the movable clamping plate 408 and the fixed clamping plate 406, can ensure the stability of the copper alloy wire sample clamping and fixing. According to the above principle, the two ends of the copper alloy wire sample can be clamped and fixed. At this time, the length of the copper alloy wire sample is greater than the distance between the upper and lower fixed clamping plates 406, so that the copper alloy wire sample is in a bent state. After the clamping is completed, the motor 301 is controlled to start and drive the bidirectional threaded rod 302 to rotate, and the transmission gear 303 and the toothed belt are cooperated to make the two bidirectional threaded rods 302 rotate synchronously, thereby driving the two movable plates 304 to move in opposite directions, and then driving the fixed frame 401 to move. At this time, the meshing transmission effect between the first gear 410 and the convex gear rod 411 causes the movable clamping plate 408 and the fixed clamping plate 406 to rotate under force, so that the winding and wrapping effect of the copper alloy wire sample can be realized. By winding the end of the copper alloy wire sample, the stability of the copper alloy wire sample fixation can be further increased to avoid sliding between the copper alloy wire sample and the movable clamping plate 408 and the fixed clamping plate 406, until the copper alloy wire sample is in a stretched state through the rotation and winding of the movable clamping plate 408 and the fixed clamping plate 406. At this time, the movable plate 304 continues to move. Since the copper alloy wire sample is in a stretched state, the fixed frame 401 does not move, that is, the movable plate 304 moves relative to the fixed frame 401. The sliding guide effect between the vertical rod 402 and the movable plate 304 can ensure the stability of the movement of the movable plate 304. At this time, the first threaded rod 407 is forced to contract, and the copper alloy wire is stretched by the force applied to the first threaded rod 407. In combination with the pressure sensor 404, the force applied to the first threaded rod 407 can be detected until the copper alloy wire breaks to obtain the tension f. Since the forces at both ends of the copper alloy wire are detected, the copper alloy wire breaking tension F=2f, and the tensile strength of the copper alloy wire is calculated according to σ=F / A. According to the above principle, the tensile strength test of multiple samples can be realized, and the tensile strength σ of the copper alloy wire obtained is compared with the standard tensile strength σ1. When σ<σ1,If the tensile strength of the copper alloy wire is not up to standard, when σ≥σ1, the tensile strength of the copper alloy wire is up to standard. The production quality of the overall copper alloy wire can be determined based on multiple sets of sample test data. This is the working principle of the tensile strength test method for copper alloy wire.

[0041] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the tensile strength of a copper alloy wire, characterized in that: The following steps are involved: Step 1: Sample selection: randomly select 10-15 coils of copper alloy wire from the produced coils; Step 2: Sample pretreatment: After randomly sampling the copper alloy wire coil, pretreat the sample according to the actual test needs to facilitate subsequent testing; Step 3: The sample is clamped and fixed to the tensile machine. During the test, both ends of the pre-treated sample are clamped on the clamping mechanism of the tensile machine, and the length of the sample is greater than the distance between the two clamping mechanisms. Step 4: The tensile testing machine is started to perform tensile testing. After the sample is clamped and fixed, the clamping mechanism is driven to move by controlling the driving mechanism to increase the distance between the clamping mechanisms until the sample breaks. With the help of the pressure sensor, the tensile force f borne by the sample when it breaks is obtained. The total tensile force borne by the sample when it breaks is F=2f. Step 5: Calculate the tensile strength according to σ=F / A, and compare the obtained tensile strength of the copper alloy wire with the standard tensile strength σ1. When σ<σ1, the tensile strength of the copper alloy wire is unqualified; when σ≥σ1, the tensile strength of the copper alloy wire is qualified. Based on 10-15 groups of sample test data, it can be determined whether the overall production quality of the copper alloy wire is qualified.

2. A method for detecting the tensile strength of a copper alloy wire according to claim 1, characterized in that: The sample pretreatment includes sample cutting, sample cleaning and drying, and sample end curling. For sample cutting, each selected copper alloy wire coil is cut by a cutting machine to a length of ≥1200 mm, and before cutting the copper alloy wire coil, 50 mm to 100 mm is removed from the end of the copper alloy wire coil.

3. A method for detecting the tensile strength of a copper alloy wire according to claim 2, characterized in that: The cleaning and drying of the sample includes cleaning and drying of the sample. For cleaning the sample, a copper alloy degreasing and rust removing agent and water are mixed in a ratio of 1:5 to form a cleaning solution, and then the intercepted sample is placed in the cleaning solution and manually inspected and turned over for 2-4 minutes.

4. A method for detecting the tensile strength of a copper alloy wire according to claim 3, characterized in that: The drying of the sample, after the sample is cleaned, the water stains are wiped off with a towel, and the sample is dried in a dryer.

5. A method for detecting the tensile strength of a copper alloy wire according to claim 2, characterized in that: The sample end curling treatment is to curl both ends of the copper alloy wire.

6. A method for detecting tensile strength of a copper alloy wire according to claim 1, characterized in that: The tensile testing machine is started to perform tensile testing, which includes sample winding and sample tensile testing. During the sample winding and tensile testing, the driving mechanism drives the clamping mechanism to move, and the copper alloy wire is in a bent state. When the clamping mechanism moves, the clamping mechanism is coordinated with the linked rotating mechanism to wind up the copper alloy wire.

7. A method for detecting the tensile strength of a copper alloy wire according to claim 6, characterized in that: The driving mechanism drives the clamping mechanism to move at a speed of 50 mm / min-100 mm / min.

8. A method for detecting tensile strength of a copper alloy wire according to claim 6, characterized in that: The sample tensile force test can be achieved by driving the clamping mechanism to continue to move after the sample is rolled up and straightened, and the tensile force f that the sample withstands when it breaks can be obtained in conjunction with the pressure sensor.

9. A method for detecting tensile strength of a copper alloy wire according to claim 1, characterized in that: The tensile machine comprises a base (1), a bracket (2), a driving mechanism (3) and a clamping mechanism (4); the bracket (2) is fixed on the base (1), and the driving mechanism (3) is installed on the bracket (2); the driving mechanism (3) comprises a motor (301), a bidirectional threaded rod (302), a transmission gear (303) and a movable plate (304); the motor (301) is fixed on the bracket (2), and the output end of the motor (301) is fixed with a bidirectional threaded rod (302), and the bidirectional threaded rod (302) is symmetrically connected to the base (1) and the bracket (2) through bearings; at the same time, a transmission gear (303) is fixed on the bidirectional threaded rod (302), and the transmission gears (303) are transmitted through toothed belts; the bidirectional threaded rod (302) is connected to the movable plate (304) through threads, and the clamping mechanism (4) is installed on the movable plate (304).

10. A method for detecting tensile strength of a copper alloy wire according to claim 9, characterized in that: The clamping mechanism (4) comprises a fixed frame (401), a vertical rod (402), a spring (403), a pressure sensor (404), a rotating frame (405), a fixed clamping plate (406), a first threaded rod (407), a movable clamping plate (408), a guide rod (409), a first gear (410) and a convex gear rod (411); the fixed frame (401) is arranged on the side of the movable plate (304); the vertical rod (402) is fixed on the fixed frame (401); the vertical rod (402) and the movable plate (304) are slidably connected; a spring (403) is fixed between the vertical rod (402) and the pressure sensor (404); the pressure sensor (404) is fixed on the movable plate (304); the fixed frame (401) The bearing is connected to a rotating frame (405), a fixed clamping plate (406) is fixed on the rotating frame (405), and a first threaded rod (407) is connected to the bearing on the fixed clamping plate (406), and the first threaded rod (407) is connected to the movable clamping plate (408) through a thread, and anti-slip teeth are provided on the movable clamping plate (408) and the fixed clamping plate (406), and the movable clamping plate (408) and the fixed clamping plate (406) are slidably connected, and the guide rod (409) is fixed on the fixed clamping plate (406), and a first gear (410) is also fixed on the rotating frame (405), and the first gear (410) and the convex gear rod (411) are meshedly connected, and the convex gear rod (411) is fixed between the base (1) and the bracket (2).

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