A cable curvature radius detection device and method for cable material testing

Abstract

The application relates to a cable curvature radius detection device and method for cable material testing, and belongs to the technical field of cable curvature radius detection. The cable curvature radius detection device for cable material testing comprises an optical detector and rotating inner rings, the rotating inner rings are hollowly arranged for fixing cables, and a shooting structure in the optical detector is directed to the cables fixed on the two groups of rotating inner rings; when the two rotating inner rings move relative to each other, the bending degree of the cables is adjusted; when the two rotating inner rings rotate synchronously, the circumferential surface of the cables directed to the shooting structure is adjusted; the application changes the circumferential surface of the cables directed to the optical detector by synchronous rotation, so that the shooting structure can acquire images of each circumferential surface of the cables, the curvature radius of the full circumferential surface of the cables is obtained, the blind area of the back arc surface and the circumferential bending deformation under a single visual angle is eliminated, the curvature data can truly and comprehensively reflect the mechanical response of the material under the full circumferential bending state.

Description

Technical Field

[0001] This invention relates to the field of cable curvature radius testing technology, and in particular to a cable curvature radius testing device and method for testing cable materials. Background Technology

[0002] Existing methods for detecting the radius of curvature of cables mostly employ optical inspection instruments. The pre-bent cable is placed in the inspection area, and images and point clouds of the curved surface are acquired using an industrial CCD camera, line laser profilometer, binocular stereo camera, or depth vision module. The radius of curvature is then calculated by the system. This non-contact optical inspection can simultaneously record the bending radius, local flatness, and changes in the arc shape after springback, making it suitable as a geometric measurement step in the testing of the bending performance of cable materials. However, such devices typically require the cable to be pre-bent and fixed into a specific shape, making it difficult to track curvature changes in real time during loading; and existing optical detection methods are based on a single fixed viewpoint or limited field of view, which can only obtain the two-dimensional profile of the cable bending section in a certain projection direction, and cannot achieve full circumferential detection of the cable.

[0003] In actual laying or dynamic bending tests, cables often do not bend along a single plane. At a bending point, there may be bending in different directions. Since single-view optical instruments can only photograph the side of the arc facing the lens, the other side of the arc facing away from the lens and the bending deformation in different directions of the cable circumference cannot be collected and identified. This makes it impossible to obtain the complete curvature distribution of the cable bending section within the 360° circumference range. It is very easy to miss the local wrinkles, flattening or stress concentration areas caused by bending, so that the obtained curvature data cannot truly and comprehensively reflect the mechanical response of the cable material under full circumferential bending. Summary of the Invention

[0004] Therefore, it is necessary to provide a cable curvature radius testing device and method for testing cable materials to address the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A cable curvature radius testing device for cable material testing includes an optical detector and symmetrical rotating inner rings. The rotating inner rings are hollow and used to fix the cable. The imaging structure inside the optical detector faces the cable fixed on the two sets of rotating inner rings. When the two rotating inner rings move relative to each other, they are used to adjust the degree of cable curvature. When the two rotating inner rings rotate synchronously, they are used to adjust the circumferential surface of the cable facing the imaging structure.

[0006] Preferably, the device further includes a rotating assembly for driving the inner rotating ring to rotate. The rotating assembly includes a sleeved outer ring, on which a rotary motor is fixedly connected. The inner rotating ring is rotatably connected within the sleeved outer ring. The output end of the rotary motor is fixedly connected to a driving gear, and a driven gear is fixedly connected to the inner rotating ring. The driven gear meshes with the driving gear.

[0007] Furthermore, the optical inspection instrument is equipped with an inspection platform, and an adjustment motor is fixedly connected to the bottom of the inspection platform. The output end of the adjustment motor is connected to an adjustment threaded rod. The threads at both ends of the adjustment threaded rod are in opposite directions and are both threadedly connected to sliding seats. The sliding seats are slidably connected to the inspection platform, and a rotating head is fixedly connected to the sliding seats. The sleeve outer ring is installed on the rotating head.

[0008] Furthermore, an auxiliary ring is fixedly connected to the upper end of the testing platform, the auxiliary ring being located between the two rotating inner rings, and a magnetic component is fixedly connected to the lower end of the testing platform, the magnetic component being magnetically attracted to the auxiliary ring.

[0009] Preferably, two sets of auxiliary rings are provided.

[0010] Preferably, the surface of the cable is coated with a grid pattern, which is a square grid pattern composed of equally spaced lines that intersect each other perpendicularly.

[0011] Furthermore, a coating roller is rotatably connected within a single rotating inner ring, the surface of the coating roller being provided with staggered coating teeth, and a corresponding pigment block being fixedly connected within the rotating inner ring; wherein, when the coating roller rotates, the coating teeth contact the pigment blocks, causing the coating teeth to be coated with pigment.

[0012] Furthermore, the brush rollers within the two rotating inner rings are arranged alternately.

[0013] Preferably, the inner rotating ring is provided with a guide groove for sliding of the shaft of the coating roller, and a locking groove is provided in the guide groove. A locking block corresponding to the locking groove is provided on the shaft of the coating roller. A piston groove is provided in the inner rotating ring, and a piston rod is slidably connected in the piston groove. A push head is fixedly connected to the piston rod in the direction close to the coating roller. The push head is in contact with the shaft of the coating roller. Multiple piston grooves are connected by a connecting groove.

[0014] A method for detecting the radius of curvature of cables used in cable material testing, including equipment for detecting the radius of curvature of cables used in cable material testing, mainly includes the following steps: The cable to be tested is inserted into the rotating inner ring. The outer surface of the cable contacts the paint teeth on the coating roller and drives the coating roller to rotate. During the rotation of the coating roller, a grid pattern is applied to the surface of the cable and the cable is locked after the coating is applied. Adjust the cable bend and use the imaging structure of an optical inspection instrument to photograph the bent cable segment to obtain the cable's radius of curvature. The two sets of rotating inner rings are driven to rotate synchronously, causing the cable to rotate around its own axis, thereby adjusting the cable orientation toward the circumferential surface of the optical inspection instrument. The optical inspection instrument's imaging structure is then used to photograph the rotating cable segment to obtain the cable's full circumferential radius of curvature.

[0015] Compared with the prior art, the present invention provides a cable curvature radius detection device and method for cable material testing, which has the following beneficial effects: This invention sets up two sets of symmetrical rotating inner rings. While adjusting the degree of cable bending, it uses synchronous rotation to change the cable's orientation toward the circumferential surface of the optical detector. This allows the imaging structure to acquire images of all circumferential surfaces of the cable, obtain the curvature radius of the cable in the entire circumferential direction, eliminate the blind spots in the acquisition of the back arc surface and circumferential bending deformation from a single perspective, and make the curvature data truly and comprehensively reflect the mechanical response of the material under the full circumferential bending state.

[0016] This invention controls two sets of rotating inner rings to move closer to each other, thereby gradually obtaining the curvature data of the cable from initial bending to ultimate failure, and determining the ultimate bending performance of the material under rated test conditions.

[0017] This invention coats the cable surface with a square grid pattern composed of equally spaced lines, providing rich feature points and feature lines for image recognition algorithms, significantly improving the accuracy and repeatability of curvature radius calculation. The straight structure of the grid changes to an arc as it bends, providing dual verification for curvature calculation. When damage occurs on the cable sheath surface, the system can accurately locate the damaged area by identifying the interruption of grid continuity, automatically eliminate interference segments to complete contour fitting, and ensure that the critical minimum curvature radius can still be accurately obtained before structural failure, avoiding misjudgment.

[0018] This invention automatically imprints a grid pattern on the cable surface before testing by rotating the coating roller and pigment block within the inner ring. The coating roller is locked by a piston rod and pusher, causing the coating teeth to press firmly against the cable for fixation. If the cable is misaligned during testing, the coating teeth will move relative to the cable and leave a contaminated section on the grid pattern. The misalignment distance can be quantified by measuring the span of the contaminated section, compensating for and correcting displacement errors in the radius of curvature calculation, and further improving testing accuracy.

[0019] The auxiliary ring of this invention works in conjunction with a magnetic component to guide the cable to bend and move adaptively in a plane parallel to the detection stage, limiting the bending direction to a stable plane, avoiding twisting or deviation, and improving the image quality. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the detection station in this invention; Figure 4 This is an isometric view of the detection stage in this invention; Figure 5 This is a schematic diagram of the adjusting threaded rod in this invention; Figure 6 This is a schematic diagram of the outer ring structure in this invention; Figure 7 This is a schematic cross-sectional view of the outer ring in this invention; Figure 8 This is a schematic diagram of the rotating inner ring in this invention; Figure 9 For the present invention Figure 8 Enlarged view of section A in the middle; Figure 10 This is a schematic diagram of the mesh texture structure in this invention; Figure 11 This is a schematic diagram of the structure of the coating roller in this invention; Figure 12 This is a schematic diagram of the structure in this invention, showing the staggered arrangement of coating rollers on two rotating inner rings; Figure 13 This is a schematic diagram of the rotating ring in this invention.

[0021] In the diagram: 1. Optical inspection instrument; 101. Inspection table; 2. Adjusting motor; 201. Adjusting threaded rod; 202. Sliding seat; 203. Rotating head; 3. Outer ring; 301. Rotary motor; 302. Drive gear; 4. Rotating inner ring; 401. Driven gear; 402. Pigment block; 403. Piston groove; 404. Connecting groove; 405. Piston rod; 406. Push head; 407. Locking groove; 5. Coating roller; 501. Paint teeth; 502. Locking block; 6. Auxiliary ring; 601. Magnetic component; 602. Rotating ring; 7. Mesh pattern. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] Example 1: Cable curvature radius testing equipment is used for cable material testing. Cable curvature radius is a data point reflecting the degree of cable bending. In cable material testing, it can be used to determine the deformation and springback of the insulation and sheath at the rated bending radius. Current methods for testing cable curvature radius mostly involve placing the bent cable in a... Figure 1 , Figure 2 Within the detection area of ​​the optical inspection instrument 1 shown, images and point clouds of the curved surface are acquired by an industrial CCD camera, a line laser profilometer, a binocular stereo camera, or a depth vision module, and the curvature radius of the cable is obtained by system calculation. This optical inspection method is completed directly within the imaging area of ​​the instrument, without the need for rigid contact with the cable surface. It can simultaneously record the bending radius, local flatness, and curvature changes after springback, making it suitable as a geometric measurement step in cable material testing. Such equipment usually requires the cable to be pre-bent and fixed into a specific shape, making it difficult to track curvature changes in real time during loading.

[0024] However, existing optical inspection methods are usually based on a single fixed viewpoint or limited field of view, which can only acquire the two-dimensional contour of the cable bending section in a certain projection direction. They cannot achieve full circumferential inspection of the cable. Secondly, in actual laying or dynamic bending tests, the cable often bends not only along a single plane, but may also bend in different directions at a bending point. Since single-view optical instruments can only photograph the side of the arc facing the lens, the other side of the arc facing away from the lens and the bending deformation in different directions of the cable circumference cannot be collected and identified. This makes it impossible to obtain the complete curvature distribution of the cable bending section within the 360° circumferential range. It is very easy to miss the local wrinkles, flattening or stress concentration areas caused by bending, so that the obtained curvature data cannot truly and comprehensively reflect the mechanical response of the cable material under full circumferential bending.

[0025] Therefore, refer to Figure 3 , Figure 4 and Figure 8This invention features two sets of symmetrical rotating inner rings 4, each hollow. The imaging structure within the optical detector 1 faces the two sets of rotating inner rings 4, allowing cable material to pass through. As the two rotating inner rings 4 move closer or further apart, the bending degree of the cable material, i.e., the radius of curvature, is adjusted. The imaging structure of the optical detector 1 captures images of the cable material's bending, and the system identifies and calculates the radius of curvature. Furthermore, as the two rotating inner rings 4 move closer together, the minimum radius of curvature of the cable material is gradually obtained. This process quantitatively acquires the entire process of the cable from initial bending to ultimate failure. Curvature data accurately determines the ultimate bending performance of materials under rated test conditions. When the two rotating inner rings 4 rotate synchronously, they are used to adjust the orientation of the cable material to the circumferential surface of the optical detector 1, so that the optical detector can capture images of the cable material on all circumferential surfaces, improve the recognition range, and realize 360° full circumferential detection of the cable bending section without blind spots. It effectively avoids the blind spots in the acquisition of the back arc surface and bending deformation in different circumferential directions under a single viewpoint, and comprehensively acquires the local wrinkles, flattening and stress concentration information of the single-point bending section in all circumferential directions, so that the curvature data truly and comprehensively reflects the mechanical response of the cable material under full circumferential bending.

[0026] In one specific implementation, refer to Figure 7 It also includes a rotating assembly that drives the inner rotating ring 4 to rotate. The rotating assembly is a sleeve outer ring 3, and a rotating motor 301 is fixedly connected to the sleeve outer ring 3. The inner rotating ring 4 is rotatably connected inside the sleeve outer ring 3. The output end of the rotating motor 301 is fixedly connected to a driving gear 302, and a driven gear 401 is fixedly connected to the inner rotating ring 4. The driven gear 401 meshes with the driving gear 302.

[0027] When the two inner rotating rings 4 need to rotate synchronously, the rotary motor 301 works, driving the inner rotating rings 4 to rotate through gear meshing.

[0028] In one specific implementation, refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 An inspection platform 101 is installed inside the optical inspection instrument 1. An adjustment motor 2 is fixedly connected to the bottom of the inspection platform 101. An adjustment threaded rod 201 is connected to the output end of the adjustment motor 2. The threads at both ends of the adjustment threaded rod 201 are in opposite directions and are each threadedly connected to a sliding seat 202. The sliding seat 202 is slidably connected to the inspection platform 101. Since the cable will change direction when bent, refer to... Figure 7 A rotating head 203 is rotatably connected to the sliding seat 202, and an outer ring 3 is mounted on the rotating head 203.

[0029] When the cable is passed through the two rotating inner rings 4, the cable is in a straight state. When it is necessary to adjust the two rotating inner rings 4 to bring the cable closer to each other so that the cable is in a bent state, the adjusting motor 2 is started. The adjusting motor 2 drives the adjusting threaded rod 201 to rotate, so that the two sliding seats 202 move closer to each other, so that the cable bends and the corresponding rotation of the outer ring 3 is adapted to the bending angle of the cable.

[0030] In one specific embodiment, when the two rotating inner rings 4 approach each other and bend the cable, the bending direction is not fixed, which affects the imaging effect of the optical detector. Therefore, refer to... Figure 3 and Figure 4 An auxiliary ring 6 is fixedly connected to the upper end of the testing table 101. The auxiliary ring 6 is located between two rotating inner rings 4. A magnetic component 601 is fixedly connected to the lower end of the testing table 101. The magnetic component 601 is magnetically attracted to the auxiliary ring 6, allowing the auxiliary ring 6 to slide along the table surface.

[0031] The magnetic component 601 is magnetically attracted to the auxiliary ring 6, which prevents the auxiliary ring 6 from moving upward and detaching from the detection table 101. When the cable passes through the auxiliary ring 6, the auxiliary ring 6 guides the cable to bend in a plane parallel to the detection table 101 and moves adaptively as the cable bends, thereby restricting the bending direction of the cable to a stable plane, allowing it to move only within the plane, avoiding upward or downward twisting or deviation, and improving the imaging quality of the optical inspection instrument.

[0032] Example 2: The cable curvature radius detection device for cable material testing is basically the same as in Example 1. However, it further fixes the cable material's curvature radius by adjusting the two rotating inner rings 4 to be close together, and synchronously drives the two rotating inner rings 4 to rotate. The optical detector can capture a full-circumferential image of the cable material at a fixed curvature radius. This method can acquire sequential images of a single bending point in multiple bending directions in space, generating a complete morphological dataset of the single-point bending segment at the fixed bending radius in all bending directions. This facilitates the analysis of the influence of different bending directions on the cable cross-sectional deformation and springback. In this detection method involving rotation under cable bending conditions, based on the electrical properties under bending conditions... When the cable material is rotated by rotating both ends, the bent part of the cable material will experience a compression phenomenon. When the bent section rotates around its own axis, the spatial orientation of the bending plane changes relative to gravity and the detection angle. The inner and outer sides of the bend are subjected to different radial pressures at different rotation angles, resulting in a single flattening deformation of the cross section. This compression stress concentration effect caused by a single multi-angle bend is used to simulate the local compression conditions that the same bending part is subjected to when it is twisted to different spatial directions at one time in actual cable laying, narrow space wiring, or static bending performance testing. That is, it simulates the stress state of a single point under a single bend in multiple directions such as horizontal, vertical, and inclined.

[0033] Example 3: The cable curvature radius detection device for cable material testing is basically the same as in Example 1. However, when the cable approaches its minimum curvature radius or has a large diameter, the force required to rotate the cable is greater, making rotation difficult. To avoid cable damage caused by forced twisting while bent, the cable is bent to the target curvature radius and an image is taken in one direction. Then, the cable is straightened and returned to its original position. Subsequently, the cable is rotated by a preset angle (5°, 10°, or 15°) while in a straight state, and then bent again to the same curvature radius and an image is taken. This process is repeated until a visual image of the cable in all circumferential directions is obtained. This rotation method, even when the cable is difficult to rotate due to bending, still enables sequential imaging of a single-point bending segment in multiple spatial directions, comprehensively reflecting the cross-sectional deformation and stress distribution of a thick cable or under extreme bending conditions. This provides a reliable and safe testing method for evaluating the bending performance of cable materials at their minimum curvature radius.

[0034] Example 4: The cable curvature radius detection device for cable material testing is basically the same as that in Example 1. However, it further involves bending the cable to a preset curvature radius by controlling two sets of rotating inner rings 4 to approach each other to a target distance, allowing the cable bending segment to reach the set bending degree. Then, the two rotating inner rings 4 are synchronously driven to rotate the cable around its own axis. During rotation, the optical detector 1 acquires contour images of the cable bending segment at preset angle intervals or continuously in real time. The system performs arc fitting calculations on the images at each rotation angle to obtain the real-time curvature radius value at that angle, and compares it with the initially set preset curvature radius. If the difference exceeds a set threshold, it is determined that the radius has changed. The amount and trend of radius change at each rotation angle are recorded, thereby quantifying the torsional and bending coupling deformation of the cable under bending conditions. This allows for precise quantification of the influence of torsional action on the cable bending shape, demonstrating the effect of the additional torque generated by rotation on the bending arc under circumferential asymmetric distribution of the cable. It can effectively identify the critical conditions for the increase or decrease of the bending radius due to torsional action, providing data support for the correction of the minimum allowable bending radius of the cable.

[0035] Example 5: The cable curvature radius detection device used for cable material testing is basically the same as that in Example 1. Furthermore, when using the optical detector 1 to photograph and identify the cable bending section, if the cable surface has a single color, lacks texture, or has high reflectivity, visual sensors such as industrial CCD cameras and line laser profilometers will find it difficult to accurately extract the edge features of the cable profile, resulting in difficulty in edge positioning and increased error in curvature radius calculation. At the same time, it is difficult to directly assess the spatial distribution and severity of deformation caused by bending, such as local wrinkles, flattening, or stress concentration, through images.

[0036] Therefore, refer to Figure 10 This invention coats the surface of the cable with a grid pattern 7, which is a square grid pattern composed of mutually perpendicular and equally spaced lines. Multiple parallel straight auxiliary lines are formed along the cable axis. Adjacent grid patterns 7 have different colors, creating a high-contrast visual mark. The grid pattern 7 can be pre-coated before the cable leaves the factory, or temporarily attached or printed onto the cable surface before testing. During the imaging process of the optical inspection instrument 1, the grid pattern provides rich feature points and feature lines for the image recognition algorithm, facilitating the extraction of the edge coordinates of the cable's bending profile and significantly improving the accuracy and repeatability of the curvature radius calculation. When the cable bends, the original straight structure along the axis transforms into an arc, and its curvature directly corresponds to the local curvature of the cable, providing dual verification for the curvature radius calculation. By observing the deformation of the grid pattern 7 during bending and rotation, the local strain distribution on the cable surface can be intuitively reflected, assisting in the identification of wrinkles, flattening, and stress concentration areas.

[0037] Secondly, when seeking the minimum radius of curvature for cable materials, damage may occur on the surface of the cable sheath. Surface damage alters the actual geometric contour of the cable's bent section, causing the optical inspection instrument 1 to misidentify the crack edges caused by the damage as the cable's bent contour line when acquiring images, thus causing the calculated radius of curvature to deviate from the true value. Simultaneously, missing or disordered image features in the damaged area can affect the system's automatic determination of the minimum radius of curvature. However, the square grid pattern 7 coated in this invention provides effective anti-interference capabilities. When damage occurs, the straight structure along the axial direction will break or misalign synchronously due to sheath cracking. The system can accurately locate the damaged area by identifying the continuity interruption of the straight structure and automatically exclude the damaged interference segment during curvature calculation, completing contour fitting based on the straight arc structure of the undamaged area. That is, even when the cable surface is damaged, it can still accurately obtain the true radius of curvature data, especially accurately determining the critical minimum radius of curvature before structural failure of the cable, avoiding misjudgment and improving the reliability of the test.

[0038] When applied to Example 1, the grid texture 7 provides a stable feature benchmark for contour recognition at all angles along the axial direction, avoiding edge extraction failure due to insufficient surface features under a single viewpoint, and ensuring the reliability and integrity of the curvature data in the entire circumference.

[0039] Secondly, it can promptly detect hidden cracks in blind areas such as the back arc surface during full-circumference inspection, thus avoiding the omission of structural damage.

[0040] When the mesh pattern 7 is applied to Example 2, by comparing the arc deformation of the straight structure in the axial direction under each rotation angle, the influence of different bending directions on the deformation and springback of the cable cross section can be quantitatively analyzed, making the full circumferential morphology data under a fixed curvature radius more intuitive.

[0041] When the mesh pattern 7 is applied to Example 3, since the cable needs to be straightened and re-bent multiple times during the step-by-step bending and rotation process, the straight line structure in the axial direction can serve as a stable spatial marker line to align the same detection area after each re-bending, ensuring the consistency and comparability of data in each circumferential direction.

[0042] When the mesh pattern 7 is applied to Example 4, the straight line structure of the square mesh can effectively distinguish between bending and torsion effects. When the cable is only bent, the straight line in the axial direction becomes a regular arc but remains parallel. When rotation introduces torsion, the straight line structure undergoes spiral distortion or shear misalignment. By identifying the distortion state of the straight line structure, it can help determine whether the change in the radius of curvature is caused by the coupling of torsion and bending or by material springback, thereby improving the accuracy of radius change detection and the reliability of critical condition identification.

[0043] In one specific embodiment, the mesh pattern 7 is sprayed and printed before testing, referring to... Figure 6 , Figure 8 , Figure 9 and Figure 11 A coating roller 5 is rotatably connected within a single rotating inner ring 4. The curvature of the coating roller 5 is similar to the circumferential curvature of the cable. Interlaced paint teeth 501 are provided on the surface of the coating roller 5 to imprint a grid pattern 7 on the cable surface. Corresponding pigment blocks 402 are fixedly connected within the rotating inner ring 4. When the coating roller 5 rotates, the paint teeth 501 contact the pigment blocks 402, so that the paint teeth 501 are coated with pigment.

[0044] When the cable is inserted into the rotating inner ring 4, the outer surface of the cable comes into contact with the paint teeth 501, and the paint teeth 501 and the brush roller 5 rotate when they come into contact, so that the paint teeth 501 alternately contact the pigment block 402 and the cable surface to coat the cable surface.

[0045] In one specific implementation, refer to Figure 12The brush rollers 5 in the upper and lower rotating inner rings 4 are staggered to prevent motion interference when the brush rollers 5 are fully arranged circumferentially in a single rotating inner ring 4; the middle state shown in the figure is a schematic diagram of the upper and lower rotating inner rings 4 when they are in the overlapping position, which is used to illustrate the staggered layout.

[0046] Secondly, during the coating process, the cable is first passed through two rotating inner rings 4 in sequence, and then pulled in the opposite direction after passing through the second rotating inner ring 4. This allows the cable, which is coated with pigment in both directions, to be positioned between the two rotating inner rings 4. In other words, the cable undergoes two coats when passing through the second rotating inner ring 4, which deepens the color of the overlapping area and forms a clear axial color boundary on the cable surface. This boundary can serve as a clear reference line extending along the cable axis, providing a stable circumferential positioning reference for the optical inspection instrument 1.

[0047] In one specific embodiment, to facilitate fixing the cable to the rotating inner ring 4 before bending and rotating the cable, and to prevent misalignment or movement of the cable during bending and rotating, refer to... Figure 9 The inner rotating ring 4 is provided with a guide groove for the sliding of the shaft of the coating roller 5, and a locking groove 407 is provided in the guide groove. A locking block 502 corresponding to the locking groove 407 is provided on the shaft of the coating roller 5. A piston groove 403 is provided in the inner rotating ring 4. A piston rod 405 is slidably connected in the piston groove 403. A push head 406 is fixedly connected to the piston rod 405 in the direction close to the coating roller 5. The push head 406 is in contact with the shaft of the coating roller 5. Multiple piston grooves 403 are connected by a connecting groove 404.

[0048] When it is necessary to fix the cable, gas is injected into the piston groove 403 to make the piston rod 405 and the push head 406 slide and squeeze the locking block 502 until it is in contact with the locking groove 407 and locked, so that the coating roller 5 stops rotating, and the paint teeth 501 on the coating roller 5 press the cable.

[0049] If the cable is still misaligned or moved, the coating teeth 501 will move relative to the cable, causing the grid pattern 7 located inside the rotating inner ring 4 to be coated and contaminated by the coating teeth 501 in real time. When the cable is removed after the test, the misalignment distance can be quantified by measuring the span of the contaminated section in the grid pattern 7, thereby compensating and correcting the error introduced by the displacement in the calculation of the radius of curvature and improving the test accuracy.

[0050] Secondly, the clearly defined boundary divides the cable surface into two distinct areas. When a certain area is damaged or contaminated, the coating stage to which it belongs can be quickly located, which helps to determine the source of the defect.

[0051] Example 6: The cable curvature radius testing equipment for cable material testing is basically the same as that in Example 4, but further, it refers to... Figure 4 When testing the radius of curvature of a flexible cable, in order to ensure that the flexible cable can rotate with the inner rotating ring 4, the cable needs to be compressed. That is, the coated teeth 501 will compress the cable. When dealing with flexible cables, the compression force can easily damage the cable surface. During bending and rotation, as the torsional force gradually moves to the middle detection part of the cable, the cable used for testing needs to be longer. It should be noted that with a longer cable, the rotational force transmitted from the inner rotating ring 4 at both ends to the middle detection part is also reduced. Therefore, refer to 4 and Figure 13 Two sets of auxiliary rings 6 are configured, and a rotating ring 602 is set in the inner ring of the auxiliary ring 6. The cable and the rotating ring 602 are interference-fitted. At this time, the area between the two auxiliary rings 6 is the detection area. When the inner ring 4 rotates, the rotational force is transmitted to the rotating ring 602 through the cable, so that the rotating ring 602 transmits the rotational force to the detection area. The interference fit can contain the cracks caused by extrusion damage on the side of the rotating ring 602 away from the detection area, without affecting the detection in the detection area, thus improving the accuracy of the detection of the curvature radius of the flexible cable.

[0052] In one specific embodiment, when the rotating ring 602 is used for testing thick cables or cables that are about to reach their minimum curvature radius, the transmission of the cable rotation force is slower. A detection structure is set on the rotating ring 602 to detect the rotation speed of the rotating ring 602. When the rotation speed of the rotating ring 602 is less than the rotation speed of the inner rotating ring 4, the operator can be alerted and the detection step of embodiment 3 can be switched.

[0053] Correspondingly, the degree of torsional deformation of the grid pattern 7 on both sides of the rotating ring 602 can be observed to help determine the transmission speed of the torsional force and whether it tends to the minimum curvature radius of the cable.

[0054] Example 7: The cable curvature radius detection method for cable material testing mainly includes the following steps: The cable to be tested is inserted into the rotating inner ring 4. The outer surface of the cable contacts the paint teeth 501 on the coating roller 5 and drives the coating roller 5 to rotate. During the rotation, the paint teeth 501 alternately contact the pigment block 402 and the cable surface, imprinting a square grid pattern 7 composed of mutually perpendicular and equally spaced lines on the cable surface, forming multiple parallel straight auxiliary lines along the cable axis as high-contrast visual marks.

[0055] Gas is introduced into the piston groove 403 in the inner rotating ring 4, driving the piston rod 405 and the pusher 406 to slide, pressing the locking block 502 on the rotating shaft of the coating roller 5 to move until it is in contact with the locking groove 407 and locked, so that the coating roller 5 stops rotating, and then the coating teeth 501 on its surface press against the cable surface to prevent the cable from axially misaligning or moving during subsequent bending and rotation.

[0056] Start the adjusting motor 2 at the bottom of the testing table 101, which drives the adjusting threaded rod 201 to rotate, causing the two threaded sliding seats 202 to move closer to each other along the testing table 101, thereby driving the two sets of rotating inner rings 4 to move closer to each other, so that the cable is bent to the target radius of curvature. During the bending process, the outer ring 3 is adaptively rotated by the rotating head 203 to adapt to the bending angle of the cable. At the same time, the cable is bent in a stable plane parallel to the surface of the testing table 101 under the guidance of the auxiliary ring 6, and the magnetic attraction between the magnetic component 601 and the auxiliary ring 6 restricts its separation, ensuring the stability of the bending direction.

[0057] The system uses the imaging structure of the optical inspection instrument 1 to photograph the bent cable segment; by identifying the rich feature points and feature lines provided by the mesh texture 7 on the cable surface, the system extracts the edge coordinates of the cable bending profile, performs arc fitting calculation, and obtains the cable curvature radius value under the current view.

[0058] When damage occurs on the cable surface, the system accurately locates the damaged area by identifying the interruption of the continuity of the straight line structure along the axial direction in the grid pattern 7, and automatically excludes the interference segment when calculating the curvature. The system then completes the contour fitting based on the arc structure of the undamaged area to avoid misjudgment.

[0059] The rotating motor 301 on the outer ring 3 is started, and the driven gear 401 on the inner ring 4 is engaged with the driving gear 302 to drive the two sets of inner rings 4 to rotate synchronously, thereby driving the cable to rotate around its own axis and adjusting the cable orientation toward the circumferential surface of the optical detector 1. During the rotation, the contour image of the cable bending section in the circumferential 360° range is collected at preset angle intervals or continuously in real time, and the calculation process is repeated to obtain the complete curvature distribution data of the single-point bending section of the cable in all directions of the circumference.

[0060] During the testing process, if the cable still experiences slight misalignment, the coating tooth 501 will move relative to the cable, forming a real-time contaminated segment on the grid pattern 7 within the rotating inner ring 4. After testing, the axial misalignment distance of the cable is quantified by measuring the span of this contaminated segment in the grid pattern 7, and the error introduced by displacement in the curvature radius calculation is compensated and corrected to output the final accurate curvature data.

Claims

1. A cable curvature radius testing device for testing cable materials, comprising an optical testing instrument (1), characterized in that, It also includes symmetrical rotating inner rings (4), which are hollow and used to fix cables. The imaging structure inside the optical detector (1) faces the cables fixed on the two sets of rotating inner rings (4). The degree of bending of the cable is adjusted as the two rotating inner rings (4) move relative to each other; When the two inner rotating rings (4) rotate synchronously, they are used to adjust the cable orientation toward the circumferential surface of the shooting structure.

2. The cable curvature radius testing device for cable material testing according to claim 1, characterized in that, It also includes a rotating assembly for driving the inner rotating ring (4) to rotate. The rotating assembly includes a sleeved outer ring (3), on which a rotary motor (301) is fixedly connected. The inner rotating ring (4) is rotatably connected inside the sleeved outer ring (3). The output end of the rotary motor (301) is fixedly connected to a drive gear (302), and the inner rotating ring (4) is fixedly connected to a driven gear (401), which meshes with the drive gear (302).

3. The cable curvature radius testing device for cable material testing according to claim 2, characterized in that, The optical detector (1) is equipped with a testing platform (101). An adjustment motor (2) is fixedly connected to the bottom of the testing platform (101). An adjustment threaded rod (201) is connected to the output end of the adjustment motor (2). The threads at both ends of the adjustment threaded rod (201) are opposite in direction and are threadedly connected to sliding seats (202). The sliding seats (202) are slidably connected to the testing platform (101). A rotating head (203) is fixedly connected to the sliding seat (202). The outer sleeve (3) is installed on the rotating head (203).

4. The cable curvature radius testing device for cable material testing according to claim 3, characterized in that, An auxiliary ring (6) is fixedly connected to the upper end of the testing platform (101). The auxiliary ring (6) is located between the two rotating inner rings (4). A magnetic component (601) is fixedly connected to the lower end of the testing platform (101). The magnetic component (601) is magnetically attracted to the auxiliary ring (6).

5. The cable curvature radius testing device for cable material testing according to claim 4, characterized in that, The auxiliary ring (6) is provided in two sets.

6. The cable curvature radius testing device for cable material testing according to claim 1, characterized in that, The surface of the cable is coated with a grid pattern (7), which is a square grid pattern composed of equally spaced lines that intersect each other perpendicularly.

7. The cable curvature radius testing device for cable material testing according to claim 6, characterized in that, A coating roller (5) is rotatably connected inside a single rotating inner ring (4). The surface of the coating roller (5) is provided with staggered paint teeth (501). A corresponding pigment block (402) is fixedly connected inside the rotating inner ring (4). When the coating roller (5) rotates, the coating teeth (501) come into contact with the pigment block (402) so that the coating teeth (501) are coated with pigment.

8. The cable curvature radius testing device for cable material testing according to claim 7, characterized in that, The two coating rollers (5) inside the two rotating inner rings (4) are arranged alternately.

9. The cable curvature radius testing device for cable material testing according to claim 7, characterized in that, The inner rotating ring (4) is provided with a guide groove for sliding the shaft of the coating roller (5). A locking groove (407) is provided in the guide groove. A locking block (502) corresponding to the locking groove (407) is provided on the shaft of the coating roller (5). A piston groove (403) is provided in the inner rotating ring (4). A piston rod (405) is slidably connected in the piston groove (403). A push head (406) is fixedly connected to the piston rod (405) in the direction close to the coating roller (5). The push head (406) is in contact with the shaft of the coating roller (5). Multiple piston grooves (403) are connected by a connecting groove (404).

10. A method for detecting the radius of curvature of a cable for testing cable materials, comprising the cable radius of curvature detection device for testing cable materials as described in claim 9, characterized in that, The main steps include: The cable to be tested is inserted into the rotating inner ring (4), and the outer surface of the cable is made to contact the paint teeth (501) on the coating roller (5) and drive the coating roller (5) to rotate. During the rotation of the coating roller (5), the cable surface is coated with the grid pattern (7), and the cable is locked after coating and imprinting. Adjust the cable bend and use the imaging structure of the optical inspection instrument (1) to take pictures of the bent cable segment to obtain the curvature radius of the cable; The two sets of rotating inner rings (4) are driven to rotate synchronously, which in turn drives the cable to rotate around its own axis, thereby adjusting the cable to face the circumferential surface of the optical detector (1), and using the imaging structure of the optical detector (1) to take pictures of the rotating cable segment in order to obtain the full circumferential curvature radius of the cable.

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