Medical steel wire rope stretching method

Abstract

The application discloses a medical steel wire rope stretching method and belongs to the technical field of medical steel wire ropes. First, the steel wire rope is placed in a preheating device for preheating treatment, and after reaching a preset temperature, the steel wire rope is installed on a stretching device for stretching. The steel wire rope is placed in a constant-temperature environment during stretching, and the crack propagation is judged by the bubble propagation on the surface of the steel wire rope. The stretching device comprises a first clamping part and a second clamping part for clamping the two ends of the steel wire rope respectively, the first clamping part is connected to a vibration excitation device through a first hollow rod, the second clamping part is connected to a stabilizing part through a second hollow rod, and the first clamping part and the second clamping part are respectively communicated with the two ends of the steel wire rope through channels formed in the inner sides. The application can solve the problem that the crack propagation of the steel wire rope cannot be recorded synchronously during the test of the existing medical steel wire rope, thereby limiting the test range.

Description

Technical Field

[0001] This invention belongs to the technical field of fatigue testing equipment, and specifically relates to a method for stretching medical steel wire ropes. Background Technology

[0002] In orthopedic surgery, medical steel wire ropes are widely used to bind bones and fix implants. Their performance directly affects the success of the surgery and the patient's recovery. Before mass production, medical steel wire ropes need to be simulated under cyclic or repetitive loads during actual use to evaluate their fatigue performance. For some hollow medical steel wire ropes, not only are conventional material fatigue performance tests required, but crack data also needs to be recorded; however, existing tensile testing methods for medical steel wire ropes cannot simultaneously record crack propagation during testing, resulting in a limited testing range. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a medical wire rope stretching method that can solve the problem that existing medical wire rope stretching methods cannot simultaneously record the crack propagation of the wire rope during testing, resulting in a limited testing range.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention discloses a method for stretching a medical steel wire rope. First, the steel wire rope is preheated in a preheating device until a preset temperature is reached. Then, the steel wire rope is installed on a stretching device for stretching. Simultaneously, the steel wire rope is placed in a constant-temperature environment, and the expansion of air bubbles on the surface of the steel wire rope is used to determine the extent of crack propagation. The stretching device includes a first clamping member and a second clamping member for clamping both ends of the steel wire rope. The first clamping member is connected to a vibration device via a first hollow rod, and the second clamping member is connected to a stabilizing member via a second hollow rod. The first and second clamping members are respectively opened on their inner sides... The channel is connected to both ends of the wire rope. The first clamping member is connected to the positive pressure air supply device through the first hollow rod. The excitation device and the stabilizing member are installed on the frame and connected to the controller. A transparent water pressure loading cylinder is installed on the frame. A pressure cap is provided with a sliding seal on the inner side of the water pressure loading cylinder. Water is contained in the space formed between the pressure cap and the water pressure loading cylinder. The water pressure loading cylinder is installed on the outer side of the wire rope. The first hollow rod slides and seals at the center of the pressure cap, and the second hollow rod slides and seals at the center of the water pressure loading cylinder. A first telescopic device for controlling the axial displacement of the pressure cap is also installed on the frame.

[0005] Furthermore, a radial loading assembly is installed on the outside of the wire rope. The radial loading assembly is connected to the output end of the second telescopic device. The second telescopic device is installed inside the hydraulic loading cylinder and can drive the radial loading assembly to move axially along the wire rope.

[0006] Furthermore, the radial loading assembly includes a support plate, a rotating seat fixed to the outer edge of the support plate, and a rotating ring installed parallel to the upper side of the support plate. The rotating ring is rotatably engaged with the rotating seat and is also connected to the rotation drive device. The support plate is connected to the output end of the second telescopic device. Several first pins are evenly distributed on the support plate. The first pins are hinged to one end of the pressure plate, and the other end of the pressure plate is connected to the rotating ring through an elastic connection device.

[0007] Furthermore, the elastic connection device includes a second pin, a connecting rod, a guide rod, a guide rod seat, a spring, and a third pin. The second pin is connected to the end of the pressure plate away from the first pin. The second pin is slidably installed in a groove opened on the connecting rod. A guide rod seat is fixed on the connecting rod, and a guide rod is fixed on the second pin. The guide rod slides through the guide rod seat. A spring connects the second pin and the guide rod seat. The third pin is connected to the end of the connecting rod away from the second pin. The third pin is also connected to the rotating ring.

[0008] Furthermore, a temperature control box is installed on the outside of the water pressure loading cylinder, and the temperature control box is mounted on the frame.

[0009] Furthermore, the first clamping member and the second clamping member have the same structure. The first clamping member includes a bottom shell fixed on the first hollow rod. A core shell is fixedly installed at the center of the bottom shell. Oblique holes are evenly opened on the core shell along the circumference. A rack clamping block is slidably installed in the oblique holes. A rotating shell is rotatably installed on the bottom shell. An internal thread that mates with the rack clamping block is opened on the inner side of the rotating shell.

[0010] Furthermore, the stabilizer is a torsion device, and the output end of the torsion device is connected to the second hollow rod.

[0011] Furthermore, the first hollow rod and the second hollow rod are rotatably connected to the rotating connecting seat, and the rotating connecting seat is installed to the frame.

[0012] The beneficial effects of this invention are as follows: This invention discloses a method for tensile testing of medical steel wire ropes, which allows for routine tensile testing of the steel wire rope using a vibration device. By installing a hydraulic loading cylinder on the outer side of the steel wire rope, and connecting the first clamping member to a positive pressure air supply device via a first hollow rod, when cracks appear on the outer side of the steel wire rope, the extent of crack propagation can be accurately determined by observing the expansion of air bubbles on the surface of the steel wire rope, thus providing more accurate test data in a timely manner.

[0013] In the device disclosed in this invention, a pressure cap is provided on the inner side of the water pressure loading cylinder for sliding sealing. By adjusting the position of the pressure cap, the test conditions of the wire rope under different pressures can be simulated, thereby making the test data more comprehensive.

[0014] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0015] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 This is a schematic diagram of the medical steel wire rope stretching method of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the radial loading component. Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 This is a schematic diagram of the structure of the first clamping component; Figure 6 for Figure 5 Enlarged view of point C in the middle; Figure 7 This is a schematic diagram of the rotating connecting seat.

[0016] The following are the markings in the attached diagram: 1. Wire rope; 2. First clamping member; 3. Second clamping member; 4. First hollow rod; 5. Second hollow rod; 6. Vibration device; 7. Frame; 8. Controller; 9. Hydraulic loading cylinder; 10. Pressure cap; 11. First telescopic device; 12. Radial loading assembly; 13. Second telescopic device; 14. Support plate; 15. Rotating seat; 16. Rotating ring; 17. Rotation drive device; 18. First pin; 10. Second pin; 20. Connecting rod; 21. Guide rod; 22. Guide rod seat; 23. Spring; 24. Third pin; 25. Slide groove; 26. Temperature control box; 27. Bottom shell; 28. Core shell; 29. ​​Inclined hole; 30. Rack and pinion clamp; 31. Rotating shell; 32. Internal thread; 33. Torque generator; 34. Rotating connecting seat. Detailed Implementation

[0017] like Figures 1-7As shown, this invention discloses a method for stretching a medical steel wire rope. First, the steel wire rope 1 is placed in a preheating device for preheating treatment. After reaching a preset temperature, the steel wire rope 1 is then installed on a stretching device for stretching. Simultaneously, the steel wire rope is placed in a constant temperature environment. The expansion of cracks is judged by the expansion of air bubbles on the surface of the steel wire rope 1. The stretching device includes a first clamping member 2 and a second clamping member 3 for clamping both ends of the steel wire rope 1. The first clamping member 2 and the second clamping member 3 have identical structures and are symmetrical about a horizontal plane. Taking the first clamping member 2 as an example, the first clamping member 2 includes a cylindrical bottom shell 27 fixed to a first hollow rod 4. A core shell 28 is fixedly installed at the center of the bottom shell 27. The core shell 28 extends downward along the axial direction, and oblique holes 29 are evenly distributed circumferentially on the core shell 28. Along the axial direction of the core shell 28, the oblique holes 29 gradually slope outwards. Three rack clamping blocks 30 are slidably installed in the three oblique holes 29 respectively. A rotating shell 31 is rotatably installed on the bottom shell 27. The inner side of the rotating shell 31 has an internal thread 32 that mates with the rack clamping blocks 30. For the sake of illustrating the structure, the enlarged view at point A of the present invention omits the bottom shell 27, which should be understood by those skilled in the art.

[0018] In practical use, the unidirectional rotating housing 31, under the action of the threaded engagement, drives the rack clamping block 30 to move axially along the inclined hole 29, thereby clamping the wire rope 1 at its lower end. When the wire rope 1 is stretched, it pushes the rack clamping block 30 outward. Under the limiting action of the inclined hole 29, the rack clamping block 30 can clamp the wire rope 1 more tightly, preventing it from loosening.

[0019] In the device of the present invention, the first clamping member 2 and the second clamping member 3 are respectively connected to the two ends of the steel wire rope 1 through the channels opened on the inner side. The first clamping member 2 is also connected to the positive pressure air supply device through the first hollow rod 4. The center of the three rack clamping blocks 30 forms a channel, and a hose can be installed in the channel. The hose is small enough to provide compressed gas to the first hollow rod 4 and the steel wire rope 1, thereby facilitating the observation of the expansion of the crack.

[0020] The first clamping member 2 is connected to the excitation device 6 via the first hollow rod 4. The excitation device 6 adopts an existing structure and can perform axial tension or compression tests. The second clamping member 3 is connected to the stabilizer via the second hollow rod 5. In some other embodiments, the stabilizer can be a conventional base, which can directly fix the second hollow rod 5. The introduced gas can be discharged through the lower end of the second hollow rod 5.

[0021] In this embodiment of the invention, the excitation device 6 and the stabilizer are simultaneously installed on the frame 7 and connected to the controller 8. The controller 8 is connected to the pressure sensor, force sensor, and air supply equipment of the test site. The above technologies are all prior art and will not be described in detail here.

[0022] Specifically, the frame 7 disclosed in this invention is equipped with a transparent hydraulic loading cylinder 9, which is cylindrical and made of explosion-proof glass. A pressure cap 10 is slidably sealed on the inner side of the hydraulic loading cylinder 9, and water is contained within the space formed between the pressure cap 10 and the hydraulic loading cylinder 9. When the pressure cap 10 moves downward, it compresses this space, thereby increasing the water pressure. Therefore, fatigue testing under different pressure conditions can be simulated, providing more comprehensive data. The hydraulic loading cylinder 9 is installed on the outside of the wire rope 1. A first hollow rod 4 is slidably sealed to the center of the pressure cap 10, and a second hollow rod 5 is slidably sealed to the center of the hydraulic loading cylinder 9. A first telescopic device 11 for controlling the axial displacement of the pressure cap 10 is also installed on the frame 7.

[0023] In this embodiment of the invention, the first telescopic device 11 employs a hydraulic cylinder. The upper end of the hydraulic cylinder is connected to a bracket, which is fixedly connected to the pressure cap 10. Under the telescopic action of the first telescopic device 11, the pressure cap 10 can be driven to compress or release the space. In some other embodiments, the first telescopic device 11 may employ a cylinder or other linear displacement mechanism, as will be understood by those skilled in the art.

[0024] In this embodiment, a radial loading assembly 12 is installed on the outer side of the wire rope 1. The radial loading assembly 12 can apply pressure to the wire rope 1 radially, thereby enabling fatigue testing of the wire rope 1 under radial pressure conditions. The radial loading assembly 12 is connected to the output end of the second telescopic device 13, which is installed inside the hydraulic loading cylinder 9. The second telescopic device 13 can drive the radial loading assembly 12 to move axially along the wire rope 1, thereby allowing selection of different positions.

[0025] In this embodiment, the radial loading assembly 12 includes a support disk 14, a rotating seat 15 fixed to the outer edge of the support disk 14, and a rotating ring 16 mounted parallel to the upper side of the support disk 14. The support disk 14 is generally annular and is used to support the entire structure. The prefabricated corresponding rotating ring 16 is also annular, and ball bearings are installed between the rotating ring 16 and the rotating seat 15. Therefore, the rotating ring 16 and the rotating seat 15 rotate in conjunction, reducing friction.

[0026] Furthermore, a gear ring is provided on the outer side of the rotating ring 16. The rotating ring 16 is also connected to the rotation drive device 17, which includes a gear meshing with the gear ring and a motor driving the gear to rotate. The support plate 14 is connected to the output end of the second telescopic device 13. Several first pins 18 are evenly distributed on the support plate 14. The first pins 18 are hinged to one end of the pressure plate, and the other end of the pressure plate is connected to the rotating ring 16 through an elastic connection device. When the motor drives the rotating ring 16 to rotate, the rotating ring 16 drives the pressure plate to rotate around the first pins 18 through the elastic connection device, thereby allowing the pressure plate to press the wire rope 1 radially. With the above structure, the present invention can apply pressure to the wire rope 1 at multiple points along the radial direction simultaneously, making control more convenient.

[0027] In this embodiment, the elastic connection device includes a second pin 10, a connecting rod 20, a guide rod 21, a guide rod seat 22, a spring 23, and a third pin 24. The second pin 10 is connected to the end of the pressure plate away from the first pin 18. The second pin 10 is slidably installed in a groove 25 opened on the connecting rod 20. The extension direction of the guide rod 21 is parallel to the groove 25. A guide rod seat 22 is fixed on the connecting rod 20. A guide rod 21 is fixed on the second pin 10. The guide rod 21 slides through the guide rod seat 22. A spring 23 is connected between the second pin 10 and the guide rod seat 22. The end of the connecting rod 20 away from the second pin 10 is connected to the third pin 24. The third pin 24 is also connected to the rotating ring 16. In this invention, the guide rod seat 22 on the connecting rod 20 can elastically press the second pin 10 with the spring 23 to achieve the radial elastic pressing of the pressure plate on the wire rope 1, so that the pressing degree of the wire rope 1 is uniform in all circumferential directions, and also reduces the possibility of jamming or damaging the surface of the wire rope 1.

[0028] In this embodiment, a temperature control box 26 is installed on the outside of the water pressure loading cylinder 9. The temperature control box 26 is installed on the frame 7. By setting the temperature control box 26, the temperature of the wire rope 1 during the fatigue test can be changed as needed.

[0029] In this embodiment, the stabilizer is a torsion device 33, and the output end of the torsion device 33 is connected to the second hollow rod 5. By setting the torsion device 33, torsional fatigue testing can be performed simultaneously on the same equipment, making operation more convenient and simplifying the structure. The first hollow rod 4 and the second hollow rod 5 are respectively rotatably connected to the rotating connecting seat 34, which is installed on the frame 7. The rotating connecting seat 34 can provide support for the first hollow rod 4 and the second hollow rod 5.

[0030] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for stretching a medical steel wire rope, characterized in that: First, the wire rope is preheated in a preheating device until it reaches the preset temperature. Then, the wire rope is installed on a tensioning device for tensioning. During tensioning, the wire rope is placed in a constant-temperature environment, and the expansion of air bubbles on the surface of the wire rope is used to determine the crack propagation. The tensioning device includes a first clamping member and a second clamping member for clamping both ends of the wire rope. The first clamping member is connected to the excitation device via a first hollow rod, and the second clamping member is connected to the stabilizing member via a second hollow rod. The first and second clamping members are connected to the wire rope through channels opened on their inner sides. The two ends are connected. The first clamping member is simultaneously connected to the positive pressure air supply device through the first hollow rod. The excitation device and the stabilizing member are simultaneously installed on the frame and connected to the controller. A transparent water pressure loading cylinder is installed on the frame. A pressure cap is provided with a sliding seal on the inner side of the water pressure loading cylinder. Water is contained in the space formed between the pressure cap and the water pressure loading cylinder. The water pressure loading cylinder is installed on the outside of the wire rope. The first hollow rod slides and seals at the center of the pressure cap, and the second hollow rod slides and seals at the center of the water pressure loading cylinder. A first telescopic device for controlling the axial displacement of the pressure cap is also installed on the frame. A radial loading assembly is installed on the outside of the wire rope. The radial loading assembly is connected to the output end of the second telescopic device. The second telescopic device is installed inside the water pressure loading cylinder. The second telescopic device can drive the radial loading assembly to move axially along the wire rope. The radial loading assembly includes a support plate, a rotating seat fixed on the outer edge of the support plate, and a rotating ring installed parallel to the upper side of the support plate. The rotating ring rotates and engages with the rotating seat. The rotating ring is also connected to the rotation drive device. The support plate is connected to the output end of the second telescopic device. Several first pins are evenly distributed on the support plate. A pin is hinged to one end of a pressure plate, and the other end of the pressure plate is connected to a rotating ring via an elastic connecting device. The elastic connecting device includes a second pin, a connecting rod, a guide rod, a guide rod seat, a spring, and a third pin. The second pin is connected to the end of the pressure plate away from the first pin. The second pin is slidably installed in a groove on the connecting rod. A guide rod seat is fixed on the connecting rod, and a guide rod is fixed on the second pin. The guide rod slides through the guide rod seat. A spring connects the second pin and the guide rod seat. The third pin is connected to the end of the connecting rod away from the second pin, and the third pin is also connected to the rotating ring.

2. The method for stretching a medical steel wire rope according to claim 1, characterized in that: A temperature control box is installed on the outside of the water pressure loading cylinder, and the temperature control box is mounted on the frame.

3. The method for stretching a medical steel wire rope according to claim 1, characterized in that: The first clamping member and the second clamping member have the same structure. The first clamping member includes a bottom shell fixed on the first hollow rod. A core shell is fixedly installed at the center of the bottom shell. Oblique holes are evenly opened on the core shell along the circumference. A rack clamping block is slidably installed in the oblique holes. A rotating shell is rotatably installed on the bottom shell. An internal thread that mates with the rack clamping block is opened on the inner side of the rotating shell.

4. The method for stretching a medical steel wire rope according to claim 1, characterized in that: The stabilizer is a torsion device, and the output end of the torsion device is connected to the second hollow rod.

5. The method for stretching a medical steel wire rope according to claim 4, characterized in that: The first hollow rod and the second hollow rod are respectively rotatably connected to the rotating connecting seat, and the rotating connecting seat is installed to the frame.

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