Internal thread copper pipe welding strength detection device

Abstract

The invention relates to the technical field of copper pipe detection, in particular to an internal thread copper pipe welding strength detection device which comprises an annular guide rail, two sliding seats arranged on the annular guide rail in a sliding mode and a driving unit, clamping units and detection units are arranged on the sliding seats, and the clamping units are used for fixing copper pipes. According to the invention, the problems of low speed and low efficiency of the traditional detection mode are effectively solved, the bending detection is used for replacing the traditional axial stretching detection, and the torque required for bending the copper pipe is far less than the tensile force required for axially snapping the copper pipe, so that the detection mode is more convenient, the structure is simple, the equipment cost is greatly reduced, and the detection efficiency is improved. Meanwhile, the copper pipe can be rapidly bent, the detection speed is higher, and the efficiency is higher; whether the welding strength is qualified or not can be quickly judged by detecting the deviation angles of the base metal on the two sides of the welding position, and the judgment mode is simpler and more efficient.

Description

Technical Field

[0001] This invention relates to the field of copper pipe testing technology, and in particular to a device for testing the welding strength of internally threaded copper pipes. Background Technology

[0002] In the fields of refrigeration, HVAC, and energy and chemical engineering, internally threaded copper tubes have become the core component of key heat exchangers (such as evaporators and condensers) due to their excellent heat transfer efficiency, compact heat exchange area, and good pressure resistance. In practical applications, multiple copper tubes often need to be connected by welding (mainly brazing) to form a circuit. Therefore, the quality of the welded joint directly determines the sealing reliability, long-term operational safety, and energy efficiency of the entire heat exchange system.

[0003] Currently, the industry commonly uses the axial tensile test method for destructive testing of the strength of copper pipe welded joints. This method requires fixing both ends of the welded joint specimen to be tested on a tensile testing machine, applying tensile forces in opposite directions along the axial direction of the pipe, and observing whether the specimen eventually breaks or deforms significantly at the weld position to determine whether the weld strength meets the strength standard. However, this traditional method has significant limitations: First, to achieve the tensile breaking of high-strength copper pipe joints, a large-tonnage tensile testing machine is required, resulting in high equipment investment and maintenance costs; second, the time required to increase from the initial load to the destructive load is long, leading to low testing efficiency. Summary of the Invention

[0004] This invention provides a device for testing the welding strength of internally threaded copper pipes, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A welding strength testing device for internally threaded copper pipe includes an annular guide rail, two slide blocks slidably disposed on the annular guide rail, and a driving unit. A clamping unit and a testing unit are disposed on the slide blocks. The clamping unit is used to fix the copper pipe and can rotate on the slide block through a support column. The testing unit is used to detect the rotation angle of the support column on the slide block. The driving unit is used to drive the two clamping units to approach each other along the annular guide rail trajectory and bend the copper tube.

[0006] Furthermore, the clamping unit includes a cylinder and a plurality of extrusion blocks disposed inside the cylinder and arranged along the circumference of the cylinder, wherein the plurality of extrusion blocks are close to or far from the axis of the cylinder.

[0007] Furthermore, the cylinder body is composed of two coaxially arranged single cylinders, and the plurality of extrusion blocks are divided into two groups corresponding to the two single cylinders, and the plurality of extrusion blocks in the two single cylinders are staggered in the circumferential direction of the single cylinders; Guide seats are provided on the inner wall of the single cylinder corresponding to each extrusion block. The extrusion block slides at an inclination on the guide seat, and the movement directions of the extrusion blocks in the two single cylinders are opposite. One single cylinder is rotatably connected to several extrusion blocks in the other single cylinder through several push-pull rods. The two single cylinders are connected by a hydraulic cylinder.

[0008] Furthermore, the clamping unit also includes a base frame connected to the support column, two support rings disposed on the base frame, and an auxiliary ring disposed on one of the support rings. The fixed end of the hydraulic cylinder is disposed on the auxiliary ring. The two single cylinders are respectively disposed in the two support rings, and one single cylinder is rotatably disposed in the corresponding support ring, while the other single cylinder is rotatably and slidably disposed in the corresponding support ring. A side plate is provided on the auxiliary ring, and a slot is provided on the side plate. A retaining edge is provided on the single cylinder to cooperate with the slot.

[0009] Furthermore, multiple slots are arranged along the axis of the single cylinder.

[0010] Furthermore, a push plate is provided on one of the single cylinders, the push plate is connected to the auxiliary ring through an elastic body, and the auxiliary ring is provided with a top post for limiting the push plate. A long platform is provided on the movable end of the hydraulic cylinder, and an inclined groove is provided on the long platform. A sliding column is slidably arranged in the inclined groove, and the sliding column is connected to the corresponding single cylinder.

[0011] Furthermore, the auxiliary ring is rotatably mounted on the support ring, and after the copper tube completes one bend and resets, the auxiliary ring is driven by a power motor to rotate 90° and bend the copper tube again.

[0012] Furthermore, the detection unit includes a sector-shaped resistor disposed on the slide and coaxial with the support column, and a conductive plate disposed on the support column and in sliding contact with the sector-shaped resistor. One end of the sector-shaped resistor and the conductive plate are both connected to an external circuit, and the sector-shaped resistor and the conductive plate are electrically connected to each other.

[0013] Furthermore, the slide is provided with a slat coaxial with the support column, and a plurality of electromagnets are arranged along the trajectory of the slat. A second conductive plate and a permanent magnet are staggered on the outer wall of the support column. During the rotation of the support column, the second conductive plate is electrically connected to at least one of the electromagnets, and the permanent magnet works in conjunction with the electromagnets.

[0014] Furthermore, a circular seat is provided at the bottom of the annular guide rail, a transmission column is rotatably provided on the circular seat, a connecting rod is provided on both of the sliding seats, the two connecting rods are connected by a transmission belt, and the transmission belt passes around the transmission column and drives the transmission. Several auxiliary rollers for supporting the transmission belt are provided on the circular seat. A transmission rack is slidably disposed on the circular base, the transmission rack is connected to one of the connecting rods, and the transmission rack is powered by a drive motor and a transmission gear; The two slides are connected by a spring.

[0015] The technical solution of this invention can achieve the following technical effects: This method effectively solves the problems of slow speed and low efficiency of traditional testing methods. By using bending testing to replace traditional axial tension testing, the torque required to bend the copper tube is much less than the tensile force required to break it along the axis. Therefore, the testing method is more convenient, the structure is simple, and the equipment cost is greatly reduced. At the same time, the copper tube can be bent quickly, making the testing speed faster and more efficient. By detecting the offset angle of the base material on both sides of the welding position, the welding strength can be quickly determined to be qualified, making the determination method simpler and more efficient. Since the bending direction and angle of the copper tube are adjustable, the testing mode can be more diversified, making it convenient to apply to different testing needs.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a device for testing the welding strength of internally threaded copper pipes; Figure 2 for Figure 1 Schematic diagram of the middle slide and clamping unit; Figure 3 This is a schematic diagram of the clamping unit. Figure 4 for Figure 3 Schematic diagram of the middle cylinder; Figure 5 for Figure 3 Schematic diagram of the middle support ring; Figure 6 for Figure 5 A structural diagram from another perspective; Figure 7 for Figure 2 Schematic diagram of the central support column; Figure 8 for Figure 7 A structural diagram from another perspective; Figure 9 for Figure 1 A schematic diagram of the structure of the drive unit; Figure 10 for Figure 9 Schematic diagram of the transmission belt structure; Reference numerals: 100, circular guide rail; 101, slide block; 200. Drive unit; 201. Round seat; 202. Transmission belt; 203. Connecting rod; 204. Transmission column; 205. Auxiliary roller; 206. Transmission rack; 207. Drive motor; 208. Transmission gear; 209. Spring; 300. Clamping unit; 301. Cylinder; 302. Extrusion block; 303. Single cylinder; 304. Guide seat; 305. Push-pull rod; 306. Hydraulic cylinder; 307. Base frame; 308. Support ring; 309. Auxiliary ring; 310. Side plate; 311. Slot; 312. Edge clamp; 313. Elastomer; 314. Push plate; 315. Top column; 316. Long platform; 317. Inclined groove; 318. Sliding column; 319. Power motor; 400. Support column; 401. Fan-shaped resistor sheet; 402. Conductive plate one; 403. Strip; 404. Electromagnet; 405. Conductive plate two; 406. Permanent magnet. Detailed Implementation

[0019] 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.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] like Figures 1 to 2As shown, this application provides a welding strength testing device for internally threaded copper pipes, including an annular guide rail 100, two slide blocks 101 slidably disposed on the annular guide rail 100, and a drive unit 200. A clamping unit 300 and a detection unit are provided on the slide blocks 101. The clamping unit 300 is used to fix the copper pipe, and the clamping unit 300 can rotate on the slide blocks 101 through a support column 400. The detection unit is used to detect the rotation angle of the support column 400 on the slide blocks 101. The drive unit 200 is used to drive the two clamping units 300 to approach each other along the trajectory of the annular guide rail 100 and bend the copper tube.

[0022] Specifically, the annular guide rail 100 is horizontally set, which can guide the two slides 101 so that the movement trajectory of the two slides 101 is arc-shaped. When the two slides 101 are located at the relative positions on both sides of the center of the annular guide rail 100, the distance between the two slides 101 is the largest. This position is set as the initial position, and the copper tube is installed at this position. The two slides 101 are allowed to move to either side of the line connecting them, thereby realizing the bending work of the copper tube. That is, the copper tube can be bent backward or forward. The specific bending direction can be determined according to the actual situation. Furthermore, since the angle of the copper tube can be changed arbitrarily in the circumferential direction when the copper tube is fixed, multiple bending detection modes of the copper tube can be realized. For example, when the copper tube is a straight tube, any bending mode is possible. When one side of the copper tube has a curved structure, its bending needs to be selected according to the direction of the curved structure of the copper tube. In addition, when the copper tube needs to be made into a bent tube, the bending direction of the copper tube during detection also needs to be selected according to its subsequent bending direction.

[0023] The two slide blocks 101 can move synchronously relative to each other, or one slide block 101 can be stationary while the other slide block 101 moves. Both can be used to bend the copper tube. The drive unit 200 can provide power for the movement of the slide blocks 101. In addition, since the slide blocks 101 are allowed to move in a circular motion on the annular guide rail 100, the distance between the two slide blocks 101 during relative movement is adjustable, and the bending angle of the copper tube can be changed at will. Therefore, different maximum bending angles can be selected according to parameters such as the copper tube wall thickness and copper tube diameter to detect the copper tube. This also realizes multiple detection modes for the copper tube.

[0024] In use, the two sliding blocks 101 are collinear with the center of the annular guide rail 100, fixing the two welded copper tubes onto the two clamping units 300. The welding position between the two copper tubes is located between the two clamping units 300, and to improve accuracy, this welding position can coincide with the axis of the annular guide rail 100. When the drive unit 200 drives the two sliding blocks 101 to move relative to each other, the two sliding blocks 101 bend the copper tubes through the clamping units 300. If the copper tube breaks directly at the welding position, the strength of the copper tube at the welding position is significantly less than that of the base material, and the copper tube weld is unqualified. If the copper tube only bends, since the length of the copper tube between the two clamping units 300 is fixed, and the copper tube will not form a sharp angle directly at the axis of the annular guide rail 100, the copper tube will bend. The bending of the tube will cause the clamping unit 300 and the support column 400 to rotate on the slide 101 in the opposite direction. That is, the direction of the base material on both sides of the welding position will be offset from its initial direction on the slide 101. The detection unit can detect this offset angle. When the rotation offset angle of the two support columns 400 is small and equal, the bending position of the copper tube is located at the welding position. At this time, the welding strength of the copper tube is unqualified. When the rotation angle of the two support columns 400 is large and equal, the bending position of the copper tube is located around the welding position and forms a large arc. At this time, the strength of the welding position is close to the strength of the base material, and the strength test is qualified. When the rotation angle of the two support columns 400 is not equal, the bending position deviates from the welding position and is located on the base material. At this time, the strength of the welding position is greater than that of the base material, and the strength test is qualified.

[0025] In some embodiments, high-pressure water can be introduced into the copper pipe during the copper pipe bending test. The high-pressure water is used to test the strength of the welded position on the inside of the copper pipe and to detect whether there is a leak at the welded position, thereby improving the accuracy and versatility of the test.

[0026] The technical solution of this invention effectively solves the problems of slow speed and low efficiency of traditional testing methods. By using bending testing to replace traditional axial tension testing, the torque required to bend the copper tube is much smaller than the tensile force required to break it along the axial direction. Therefore, the testing method is more convenient, the structure is simple, and the equipment cost is greatly reduced. At the same time, the copper tube can be bent quickly, making the testing speed faster and the efficiency higher. By detecting the offset angle of the base material on both sides of the welding position, the welding strength can be quickly determined to be qualified, which is simpler and more efficient. Since the bending direction and angle of the copper tube are adjustable, the testing mode can be more diversified, making it convenient to apply to different testing needs.

[0027] Furthermore, such as Figure 4 As shown, the clamping unit 300 includes a cylinder 301 and a plurality of extrusion blocks 302 disposed inside the cylinder 301 and arranged along the circumference of the cylinder 301. The plurality of extrusion blocks 302 are close to or away from the axis of the cylinder 301.

[0028] The cylinder 301 provides support for several extrusion blocks 302. When the copper tube passes through the cylinder 301, the extrusion blocks 302 can extrude the copper tube from the circumferential direction, thereby fixing the copper tube. Initially, the axis of the cylinder 301 is along the radial direction of the annular guide rail 100, and the two cylinders 301 are coaxially arranged, which facilitates the positioning of the copper tube. When the copper tube bends, the reaction force of the copper tube on the cylinder 301 will cause it to rotate relative to the slide block 101. At this time, the axis of the cylinder 301 deviates from its original axis direction. It should be noted that when the extrusion blocks 302 move synchronously, they will achieve the function of fixing the axis of the copper tube, and the axis of the copper tube will coincide with the axis of the cylinder 301.

[0029] Furthermore, such as Figures 3 to 4 As shown, the cylinder 301 is composed of two coaxially arranged single cylinders 303, and a number of extrusion blocks 302 are divided into two groups corresponding to the two single cylinders 303. In the circumferential direction of the single cylinders 303, the number of extrusion blocks 302 in the two single cylinders 303 are arranged alternately. Guide seats 304 are provided on the inner wall of the single cylinder 303 corresponding to each extrusion block 302. The extrusion block 302 slides at an inclination on the guide seat 304, and the movement directions of the extrusion blocks 302 in the two single cylinders 303 are opposite. One single cylinder 303 is rotatably connected to several extrusion blocks 302 in another single cylinder 303 through several push-pull rods 305. The two single cylinders 303 are connected by a hydraulic cylinder 306.

[0030] The guide seat 304 can provide guidance for the movement of the extrusion block 302. When the hydraulic cylinder 306 performs telescopic movement, it will push the two single cylinders 303 to move relative to each other. One single cylinder 303 will push the extrusion block 302 on the other single cylinder 303 to move through its push-pull rod 305, thereby causing the extrusion blocks 302 in both single cylinders 303 to move at an angle. The angle movement of the extrusion block 302 is decomposed into movement in the radial direction along the single cylinder 303 and movement in the axial direction of the single cylinder 303. The radial movement can be used to extrude the outer wall of the copper tube, thereby using the extrusion blocks 302 on the two single cylinders 303 to clamp the copper tube at two positions, and each position adopts a circumferential clamping method.

[0031] It should be noted that since the extrusion blocks 302 on both single cylinders 303 are inclined in opposite directions, the friction between the copper tube and the extrusion blocks 302 can be used to limit the copper tube in two directions along its own axis. Figure 4For example, when the copper tube tends to move to the right, the friction provided by the copper tube to the right-side pressing block 302 will cause the pressing block 302 to move towards the axis of the single cylinder 303. That is, the pressing blocks 302 on the right side provide stronger pressing force to the copper tube. When the copper tube tends to move to the left, the pressing blocks 302 on the left side also provide stronger pressing force to the copper tube. Thus, the pressing blocks 302 on both the left and right sides provide a clamping effect of locking to the left and locking to the right for the copper tube, making the copper tube more secure.

[0032] The rotation axes of the push-pull rods 305 at both ends and the extrusion blocks 302 and the single cylinder 303 are perpendicular to the axis of the single cylinder 303. In this way, the push-pull rods 305 can guide the two single cylinders 303, keeping them coaxial. The extrusion blocks 302 inside the single cylinder 303 can achieve synchronous movement. When the extrusion blocks 302 clamp the copper tube, they can make the axis of the copper tube coincide with the axis of the single cylinder 303.

[0033] Furthermore, such as Figures 3 to 6 As shown, the clamping unit 300 also includes a base frame 307 connected to the support column 400, two support rings 308 disposed on the base frame 307, and an auxiliary ring 309 disposed on one of the support rings 308. The fixed end of the hydraulic cylinder 306 is disposed on the auxiliary ring 309. Two single cylinders 303 are respectively disposed in the two support rings 308, and one single cylinder 303 is rotatably disposed in the corresponding support ring 308, while the other single cylinder 303 is rotatably and slidably disposed in the corresponding support ring 308. A side plate 310 is provided on the auxiliary ring 309, and a slot 311 is provided on the side plate 310. A retaining edge 312 is provided on the single cylinder 303 to cooperate with the slot 311.

[0034] The base frame 307 can support the two single cylinders 303 by two support rings 308. One support ring 308 fixes the position of the single cylinder 303 on it, while the other support ring 308 allows the single cylinder 303 on it to move freely. In this way, when the hydraulic cylinder 306 retracts, the single cylinder 303 can slide on the corresponding support ring 308, so that the two single cylinders 303 move closer or further away from each other.

[0035] The auxiliary ring 309 provides support for the hydraulic cylinder 306 and the side plate 310. When the two single cylinders 303 approach each other and the squeezing block 302 inside squeezes the copper tube, the two single cylinders 303 no longer move. At this time, the two single cylinders 303 can be rotated so that their upper clamping edge 312 is inserted into the clamping groove 311 on the side plate 310. The clamping groove 311 locks the position of the two single cylinders 303, so that the two single cylinders 303 cannot move relative to each other, thereby realizing the locking function of the copper tube.

[0036] Furthermore, such as Figure 6As shown, multiple slots 311 are arranged along the axis of the single cylinder 303.

[0037] When the clamping unit 300 clamps copper tubes of different diameters, the final distance between the two single cylinders 303 is not equal. At this time, the locking edges 312 on the two single cylinders 303 can be inserted into different slots 311 on the side plate 310, thereby realizing the locking function of copper tubes of different diameters. Since one single cylinder 303 is only allowed to rotate on the corresponding support ring 308, the locking edge 312 on the single cylinder 303 only cooperates with the fixed slot 311 on the side plate 310, while the other single cylinder 303 will cooperate with different slots 311 on the side plate 310. In some embodiments, several slots 311 can be configured only for the locking edge 312 on the single cylinder 303 that can move along its own axis, while the locking edge 312 on the single cylinder 303 that only rotates can be omitted, and it can also realize the locking function.

[0038] Furthermore, such as Figure 5 As shown, a push plate 314 is provided on a single cylinder 303. The push plate 314 is connected to the auxiliary ring 309 through an elastic body 313, and the auxiliary ring 309 is provided with a top post 315 to limit the push plate 314. A long platform 316 is provided on the movable end of the hydraulic cylinder 306. An inclined groove 317 is provided on the long platform 316. A sliding column 318 is slidably arranged in the inclined groove 317 and is connected to the corresponding single cylinder 303.

[0039] The push plate 314 is generally set on the single cylinder 303 in the support ring 308 corresponding to the auxiliary ring 309. The elastic body 313 provides elastic thrust to the push plate 314, which keeps it in contact with the top column 315, thereby limiting the position of the single cylinder 303 on the support ring 308. When the hydraulic cylinder 306 retracts, since the single cylinder 303 cannot rotate, the hydraulic cylinder 306 will push the single cylinder 303, which is allowed to move linearly, through the long platform 316 and the sliding column 318. The two single cylinders 303 move closer or further apart. When the extrusion block 302 completes the compression of the copper tube... During the clamping operation, the single cylinder 303 cannot move linearly. At this time, the power provided by the hydraulic cylinder 306 to the long platform 316 will cause the sliding column 318 to rotate through the inclined groove 317, that is, the two single cylinders 303 will rotate. The clamping edge 312 on the single cylinder 303 can smoothly slide into the corresponding clamping groove 311, thereby realizing the clamping and locking function of the clamping unit 300 on the copper tube. The clamping function will be realized first, and then the locking function will be realized. When the single cylinder 303 rotates, it will push the elastic body 313 to undergo elastic deformation through the push plate 314.

[0040] Furthermore, such as Figures 5 to 6As shown, the auxiliary ring 309 is rotatably mounted on the support ring 308. After the copper tube completes one bend and resets, the auxiliary ring 309 is driven by the power motor 319 to rotate 90° and bend the copper tube again.

[0041] When the auxiliary ring 309 rotates, the single cylinder 303 and its inner copper tube will rotate synchronously, thereby adjusting the angle of the copper tube and making it easy to bend the welding position on the copper tube in any direction.

[0042] During use, after the copper tube completes one bend, the two slide blocks 101 return to their original positions, and the two clamping units 300 straighten the copper tube again. Then, the auxiliary ring 309 rotates 90°, and the crease on the copper tube changes from a vertical state to a horizontal state. When the two slide blocks 101 move again and bend the copper tube, the hardness of the original crease position on the copper tube is relatively greater than that of the base material. The bending area will appear in other areas of the copper tube. If the bending position is still on the base material, then the strength of the copper tube welding position meets the specified requirements.

[0043] The above method allows for two strength tests on the same copper tube, resulting in higher accuracy.

[0044] Furthermore, such as Figure 7 As shown, the detection unit includes a sector-shaped resistor 401 disposed on the slide 101 and coaxial with the support column 400, and a conductive plate 402 disposed on the support column 400 and in sliding contact with the sector-shaped resistor 401. One end of the sector-shaped resistor 401 and the conductive plate 402 are both connected to an external circuit, and the sector-shaped resistor 401 and the conductive plate 402 are electrically connected to each other.

[0045] When the support column 400 rotates, it will drive the conductive plate 402 to move synchronously. The conductive plate 402 can contact different positions on the sector resistor 401, thereby changing the length of the sector resistor 401 connected to the circuit. The rotation angle of the support column 400 can be detected by detecting the change in current and resistance in the circuit.

[0046] Furthermore, such as Figure 7 and Figure 8 As shown, a slat 403 coaxial with the support column 400 is provided on the slide 101. Several electromagnets 404 are arranged along the trajectory of the slat 403. A conductive plate 405 and a permanent magnet 406 are staggered on the outer wall of the support column 400. During the rotation of the support column 400, the conductive plate 405 is electrically connected to at least one electromagnet 404. The permanent magnet 406 works in conjunction with the electromagnet 404.

[0047] Conductive plate 405 is connected to an external circuit, and this circuit is different from the circuit containing the sector resistor 401. When conductive plate 405 contacts an electromagnet 404 on the plate 403, the electromagnet 404 is connected to the circuit and generates magnetic force. The magnetic force on the electromagnet 404 will attract the permanent magnet 406. When the support column 400 rotates, the support column 400 needs to overcome the magnetic force. As the support column 400 rotates, conductive plate 405 will contact different electromagnets 404 on the plate 403 in sequence, so that several electromagnets 404 are charged in sequence and generate magnetic force. The electromagnets 404 that generate magnetic force are always close to the moving permanent magnet 406, so that the resistance on the support column 400 is constant. This resistance can be regarded as the reset force provided for the support column 400. At the same time, this force will not fluctuate too much with the rotation of the support column 400, that is, the reset force on the support column 400 is approximately constant.

[0048] The above structure can prevent the support column 400 from rotating arbitrarily. Since the conductive plate 405 and the permanent magnet 406 are misaligned, the charged electromagnet 404 and the permanent magnet 406 are misaligned with each other. This misalignment can ensure that the magnetic pull always provides a restoring force for the support column 400. If the charged electromagnet 404 and the permanent magnet 406 are aligned instead of misaligned, then when the electromagnet 404 and the permanent magnet 406 are aligned, the force between them will be perpendicular to the axis of the support column 400, and will not pull the support column 400 to rotate.

[0049] Furthermore, such as Figures 9 to 10 As shown, a circular seat 201 is provided at the bottom of the annular guide rail 100. A transmission column 204 is rotatably mounted on the circular seat 201. A connecting rod 203 is provided on each of the two sliding seats 101. The two connecting rods 203 are connected by a transmission belt 202, and the transmission belt 202 passes around the transmission column 204 and drives the transmission. Several auxiliary rollers 205 for supporting the transmission belt 202 are provided on the circular seat 201. A transmission rack 206 is slidably disposed on the round base 201. The transmission rack 206 is connected to a connecting rod 203. The transmission rack 206 is powered by a drive motor 207 and a transmission gear 208. The two slides 101 are connected by a spring 209.

[0050] The circular seat 201 can provide support for the annular guide rail 100. The arrangement of the two connecting rods 203 and the transmission column 204 is such that when one slide 101 and its connecting rod 203 move toward the transmission column 204, the connecting rod 203 will pull the other connecting rod 203 to move synchronously toward the transmission column 204 via the transmission belt 202, thereby making the two slides 101 move synchronously relative to each other. The movement of the transmission belt 202 will drive the transmission column 204 to rotate. In order to avoid friction between the transmission belts 202 on both sides of the transmission column 204 and between the transmission belts 202 and the circular seat 201, several auxiliary rollers 205 can be used for guidance, thereby reducing transmission friction.

[0051] The drive motor 207 is mounted on the circular base 201, and the transmission gear 208 is connected to the transmission rack 206. In this way, the drive motor 207 and the transmission gear 208 can drive the transmission rack 206 to move on the circular base 201. The transmission rack 206 can drive the corresponding connecting rod 203 to move, thereby providing power for the movement of the two clamping units 300 and the bending of the copper tube.

[0052] The spring 209 between the two slides 101 can be elastically bent when the two slides 101 move relative to each other, thereby providing a restoring force for the two slides 101 and ensuring that the transmission belt 202 is always taut.

[0053] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A device for testing the welding strength of internally threaded copper pipes, characterized in that, The device includes an annular guide rail, two slide blocks slidably disposed on the annular guide rail, and a drive unit. A clamping unit and a detection unit are disposed on the slide blocks. The clamping unit is used to fix the copper tube and can rotate on the slide block via a support column. The detection unit is used to detect the rotation angle of the support column on the slide block. The driving unit is used to drive the two clamping units to move closer to each other along the annular guide rail trajectory and bend the copper tube. The clamping unit includes a cylinder and a plurality of extrusion blocks disposed inside the cylinder and arranged along the circumferential direction of the cylinder, wherein the plurality of extrusion blocks are close to or far from the axis of the cylinder. The cylinder is composed of two coaxially arranged single cylinders, and the extrusion blocks are divided into two groups corresponding to the two single cylinders. In the circumferential direction of the single cylinders, the extrusion blocks in the two single cylinders are arranged alternately. Guide seats are provided on the inner wall of the single cylinder corresponding to each extrusion block. The extrusion block slides at an inclination on the guide seat, and the movement directions of the extrusion blocks in the two single cylinders are opposite. One single cylinder is rotatably connected to several extrusion blocks in the other single cylinder through several push-pull rods. The two single cylinders are connected by a hydraulic cylinder.

2. The welding strength testing device for internally threaded copper pipes according to claim 1, characterized in that, The clamping unit further includes a base frame connected to the support column, two support rings disposed on the base frame, and an auxiliary ring disposed on one of the support rings. The fixed end of the hydraulic cylinder is disposed on the auxiliary ring. The two single cylinders are respectively disposed in the two support rings, and one single cylinder is rotatably disposed in the corresponding support ring, while the other single cylinder is rotatably and slidably disposed in the corresponding support ring. A side plate is provided on the auxiliary ring, and a slot is provided on the side plate. A retaining edge is provided on the single cylinder to cooperate with the slot.

3. The welding strength testing device for internally threaded copper pipes according to claim 2, characterized in that, Multiple slots are arranged along the axis of the single cylinder.

4. The welding strength testing device for internally threaded copper pipes according to claim 2, characterized in that, A push plate is provided on one of the single tubes, and the push plate is connected to the auxiliary ring through an elastic body. The auxiliary ring is provided with a top post for limiting the push plate. A long platform is provided on the movable end of the hydraulic cylinder, and an inclined groove is provided on the long platform. A sliding column is slidably arranged in the inclined groove, and the sliding column is connected to the corresponding single cylinder.

5. The welding strength testing device for internally threaded copper pipes according to claim 2, characterized in that, The auxiliary ring is rotatably mounted on the support ring. After the copper tube completes one bend and resets, the auxiliary ring is driven by a power motor to rotate 90° and bend the copper tube again.

6. The welding strength testing device for internally threaded copper pipes according to claim 1, characterized in that, The detection unit includes a sector-shaped resistor sheet disposed on the slide and coaxial with the support column, and a conductive plate disposed on the support column and in sliding contact with the sector-shaped resistor sheet. One end of the sector-shaped resistor sheet and the conductive plate are both connected to an external circuit, and the sector-shaped resistor sheet and the conductive plate are electrically connected to each other.

7. The welding strength testing device for internally threaded copper pipes according to claim 1, characterized in that, The slide block is provided with a slat coaxial with the support column. Several electromagnets are arranged along the trajectory of the slat. A second conductive plate and a permanent magnet are staggered on the outer wall of the support column. During the rotation of the support column, the second conductive plate is electrically connected to at least one of the electromagnets. The permanent magnet works in conjunction with the electromagnet.

8. The welding strength testing device for internally threaded copper pipes according to claim 1, characterized in that, A circular seat is provided at the bottom of the annular guide rail, and a transmission column is rotatably mounted on the circular seat. A connecting rod is provided on each of the two slides, and the two connecting rods are connected by a transmission belt. The transmission belt passes around the transmission column and drives the transmission. Several auxiliary rollers for supporting the transmission belt are provided on the circular seat. A transmission rack is slidably disposed on the circular base, the transmission rack is connected to one of the connecting rods, and the transmission rack is powered by a drive motor and a transmission gear; The two slides are connected by a spring.

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