An induction welding tool for semi-steel cable and a welding method thereof

Abstract

The present application relates to the technical field of welding of semi-steel cable, and particularly relates to an induction welding tool for semi-steel cable and a welding method thereof. The welding tool comprises a coaxial positioning mechanism, an induction welding mechanism, a data acquisition assembly, an end face inclination angle determination module, a coaxiality detection module, an eccentric moment correction module and a welding quality detection module. The method comprises determining whether there is an angular inclination on the fitting end face based on a circumferential pressure balance index; under the condition that there is an angular inclination, determining whether the coaxiality is qualified based on the horizontal distance between the clamping groove and the vertical center line of the counterbore; determining whether the gravity eccentric moment of the semi-steel workpiece is qualified based on the bending deflection amount of the semi-steel workpiece, and adjusting the righting distance of the righting block based on the unqualified condition; welding the tail pipe and the semi-steel workpiece, and determining whether the welding quality is qualified based on the circumferential spreading uniformity of the metallurgical bonding layer, so as to optimize the preset balance index. The welding quality of the tail pipe and the semi-steel workpiece is improved.

Description

Technical Field

[0001] This invention relates to the field of welding technology for semi-steel cables, and more particularly to an induction welding fixture and welding method for semi-steel cables. Background Technology

[0002] Semi-steel cables, due to their excellent rigidity, stable radio frequency transmission performance, and strong anti-interference ability, are widely used in communication equipment, precision instruments, 5G base stations, testing equipment, and other fields. The welding of the tail tube to the semi-steel cable is a core and critical process in its assembly, directly determining the mechanical reliability, electrical contact consistency, and sealing performance of the semi-steel cable joint. Currently, induction welding is widely used for welding the tail tube to the semi-steel cable. This process has advantages such as fast heating speed, uniform heating, high welding efficiency, and a small heat-affected zone on the workpiece, and has become the mainstream welding method in the industry. Existing induction welding fixtures for semi-steel cables primarily focus on the coaxiality calibration of the clamping groove and countersunk hole, aiming to achieve basic positioning accuracy by ensuring error-free alignment of the semi-steel cable and tail tube when placed on the mating end face during welding. However, in actual production, the asymmetry of the structure of bent semi-steel cables leads to a deviation in the center of gravity moment. After the semi-steel cable is clamped and fixed, this deviation in the center of gravity moment generates a continuous small overturning moment, acting on the mating end face of the tail tube and the semi-steel cable, which may cause a slight angular tilt of the end face. This slight angular tilt can directly lead to uneven circumferential contact gaps on the mating end faces, resulting in small gaps on the tilted side and excessive tightness on the opposite side, which in turn can cause a series of quality problems during the welding process.

[0003] Chinese Patent Application Publication No. CN115401385A discloses a welding fixture and fixing method for high-frequency semi-rigid cable assemblies, including a base; a mounting side plate on the side of the base, one end of which is vertically connected to the base; several through I-shaped grooves on the mounting side plate; a first clamp and a second clamp, both of which can move freely along the I-shaped grooves on the mounting side plate; and a semi-rigid cable locking mechanism at the other end of each clamp. A positioning seat on the outer circumference of the mounting shaft is rotatable along the axial direction of the mounting shaft and is fixed by the locking mechanism. The beneficial effects of this invention are simple operation, low manufacturing cost, long service life, ability to weld irregularly shaped cables, small coaxiality error between the inner and outer conductors of the cable, flat reference surface, consistent welding product quality, and a 200% increase in efficiency.

[0004] The existing technology also has the following problems: during the welding process of the bent semi-steel workpiece and the tail pipe, the structural asymmetry of the bent semi-steel workpiece causes the center of gravity moment to be offset, resulting in the angular tilt of the contact end face between the tail pipe and the semi-steel workpiece, which in turn leads to poor welding quality between the tail pipe and the semi-steel workpiece. Summary of the Invention

[0005] Therefore, the present invention provides an induction welding fixture and welding method for semi-steel cables to overcome the problem in the prior art that the structural asymmetry of the bent semi-steel workpiece causes a deviation in the center of gravity moment during the welding process of the bent semi-steel workpiece and the tail tube, resulting in an angular tilt at the contact end face of the tail tube and the semi-steel workpiece, which in turn leads to poor welding quality of the tail tube and the semi-steel workpiece.

[0006] To achieve the above objectives, in one aspect, the present invention provides an induction welding fixture for semi-steel cables, comprising:

[0007] A coaxial positioning mechanism includes a base plate, a lifting slide table disposed at one end of the upper surface of the base plate, a straightening block disposed on the side surface of the lifting slide table for straightening a semi-steel workpiece, the straightening block being provided with a clamping groove, and a positioning seat disposed at one end of the upper surface of the base plate away from the lifting slide table.

[0008] The data acquisition component includes a laser line marker for detecting the coaxiality of the clamping groove and the countersunk hole, a miniature pressure sensor array for detecting the pressure between the tail tube and the inner wall of the countersunk hole, and an image acquisition device for acquiring image information of the semi-steel workpiece in real time.

[0009] The end face tilt angle determination module is used to determine whether there is an angular tilt at the contact end face of the tail tube and the semi-steel workpiece based on the comparison result of the circumferential pressure balance index of the pressure between the tail tube and the inner wall of the counterbore and the preset balance index.

[0010] A coaxiality detection module, which responds to the presence of angular tilt, determines whether the coaxiality of the clamping groove and the countersunk hole is qualified based on the horizontal distance between the vertical center lines of the clamping groove and the countersunk hole.

[0011] The eccentricity correction module, in response to the coaxiality being qualified, is used to determine whether the gravitational eccentricity of the semi-steel workpiece is qualified based on the bending deflection of the semi-steel workpiece, and adjusts the straightening distance of the straightening block based on the condition that the gravitational eccentricity is not qualified.

[0012] The welding quality inspection module is used to determine whether the welding quality of the tail pipe and the semi-steel workpiece is qualified based on the circumferential spreading uniformity of the metallurgical bonding layer at the weld end face of the tail pipe and the semi-steel workpiece, and to optimize the preset equilibrium index based on the unqualified conditions.

[0013] Furthermore, the positioning seat has several countersunk holes for accommodating the tail tube, and through holes coaxially connected to the countersunk holes to enable coaxial guidance of the semi-steel workpiece.

[0014] Furthermore, the end face tilt angle determination module determines that the contact end face of the tail tube and the semi-steel workpiece has an angular tilt based on the comparison result that the circumferential pressure balance index is less than the preset balance index.

[0015] Furthermore, under the condition of angular tilt, the coaxiality detection module determines that the coaxiality of the clamping groove and the countersunk hole is qualified based on the comparison result that the horizontal distance is less than or equal to a preset distance.

[0016] Furthermore, under the condition that the coaxiality is qualified, the eccentricity correction module determines that the gravity eccentricity of the semi-steel workpiece is unqualified based on the judgment result that the bending deflection is greater than the preset deflection.

[0017] Furthermore, under the condition that the eccentric moment of gravity of the semi-steel workpiece is unqualified, the eccentric moment correction module determines to adjust the straightening distance of the straightening block by a first distance adjustment coefficient based on the comparison result that the difference between the bending deflection amount and the preset deflection amount is less than or equal to the preset deflection difference.

[0018] The eccentric torque correction module determines the straightening distance of the straightening block to be adjusted by a second distance adjustment coefficient based on the comparison result that the difference in deflection is greater than the preset difference in deflection.

[0019] Furthermore, the circumferential spreading uniformity is determined based on the echo amplitude of the circumferential ultrasonic scan of the metallurgical bonding layer between the tailpipe and the semi-steel workpiece.

[0020] Furthermore, the welding quality inspection module determines that the welding quality of the tailpipe and the semi-steel workpiece is unqualified based on the comparison result that the circumferential spreading uniformity is greater than the preset uniformity.

[0021] Furthermore, under the condition that the welding quality of the tail pipe and the semi-steel workpiece is unqualified, the welding quality detection module sets several index correction coefficients to optimize the preset equilibrium index based on the difference between the circumferential spreading uniformity and the preset uniformity, and the comparison result of the difference between the preset uniformity and the preset uniformity.

[0022] On the other hand, the present invention also provides an induction welding method for semi-steel cables, including...

[0023] Based on the circumferential pressure balance index of the pressure between the tail tube and the inner wall of the counterbore, the comparison result with the preset balance index determines whether there is angular tilting at the contact end face of the tail tube and the semi-steel workpiece.

[0024] Under the condition that there is an angular inclination at the contact end face of the tail tube and the semi-steel workpiece, the coaxiality of the clamping groove and the countersunk hole is determined based on the horizontal distance between the vertical center lines of the clamping groove and the countersunk hole.

[0025] Under the condition that the coaxiality of the clamping groove and the countersunk hole is qualified, the gravitational eccentricity of the semi-steel workpiece is determined based on the bending deflection of the semi-steel workpiece, and the straightening distance of the straightening block is adjusted based on the condition that the gravitational eccentricity is not qualified.

[0026] The tailpipe and the semi-steel workpiece are welded together. Based on the circumferential spreading uniformity of the metallurgical bonding layer at the weld end face of the tailpipe and the semi-steel workpiece, the welding quality of the tailpipe and the semi-steel workpiece is determined to be qualified. The preset balance index is optimized based on the unqualified condition.

[0027] Compared with the prior art, the beneficial effects of the present invention are that the present invention forms a dual positioning guarantee through the clamping and straightening of the straightening block of the coaxial positioning mechanism and the rigid positioning of the positioning seat. Combined with the precise detection of coaxiality by the laser line marker and the real-time monitoring of the pressure distribution of the tail tube and the countersunk hole by the micro pressure sensor array, the positioning benchmark is accurately controlled, effectively avoiding the end face fitting tilting problem caused by tooling assembly deviation, improving the basic welding quality from the source, thereby improving the welding quality of the tail tube and the semi-steel workpiece.

[0028] Furthermore, by determining the end face tilt angle and detecting coaxiality, this invention accurately identifies whether there is an angular tilt on the contact end face of the microscopic semi-steel workpiece, and whether it is caused by the coaxiality deviation of the tooling or by the gravity of the semi-steel bending. Then, by adjusting the straightening distance of the straightening block, the eccentric torque of gravity generated by the bending of the semi-steel workpiece is offset, avoiding uneven weld gap caused by slight end face tilt, thereby further improving the welding quality of the tailpipe and the semi-steel workpiece.

[0029] Furthermore, the welding quality inspection module of the present invention uses ultrasonic scanning as its core to obtain data on the circumferential uniformity of the metallurgical bonding layer to accurately determine the welding quality. At the same time, it dynamically optimizes the preset balance index based on the welding defects, effectively reducing welding defects such as insufficient solder filling, cold solder joints, and excessively thin welds, and improving the mechanical bonding force and electrical contact consistency of the weld, thereby further improving the welding quality of the tailpipe and the semi-steel workpiece.

[0030] Furthermore, the semi-steel end-face cutting device of the present invention relies on the differential transmission mechanism of stepper motor drive and gearbox, and works in conjunction with the blade assembly and eccentric cover plate to achieve precise cutting of semi-steel outer conductor. The feeding depth is strictly controlled by length limiting screws to ensure that the end face of semi-steel workpiece is flat and dimensionally accurate, providing a preliminary guarantee for the tight fit between tail tube and semi-steel workpiece, reducing welding defects caused by uneven end face, thereby further improving the welding quality of tail tube and semi-steel workpiece. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the induction welding fixture for semi-steel cables according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram showing the positions of the tail tube and the semi-steel workpiece in the positioning seat according to an embodiment of the present invention;

[0033] Figure 3This is a structural block diagram of an induction welding fixture for semi-steel cables according to an embodiment of the present invention;

[0034] Figure 4 A flowchart for determining whether there is an angular tilt at the contact end face between the tailpipe and the semi-steel workpiece in an embodiment of the present invention;

[0035] Figure 5 This is a flowchart of an embodiment of the induction welding method for semi-steel cables according to the present invention;

[0036] Figure 6 This is a schematic diagram of the semi-steel end-face cutting device according to an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the cutter head structure according to an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of the blade assembly according to an embodiment of the present invention;

[0039] In the diagram: 1. Base plate, 2. Lifting slide, 3. Alignment block, 4. Clamping slot, 5. Positioning seat, 6. Induction welding head assembly, 7. Induction welding machine housing, 8. Semi-steel workpiece, 9. Tail tube, 10. Countersunk hole, 11. Through hole, 12. Image acquisition device, 13. Miniature pressure sensor array, 14. Housing, 15. Controller, 16. Cutting head, 17. Foot pad, 18. Gearbox, 19. Stepper motor mounting base, 20. Stepper motor, 21. Coupling, 22. Feed port, 23. Outer shaft of cutting head, 24. Inner shaft of cutting head, 25. Length limit screw, 26. Blade assembly, 27. Blade, 28. Tool holder, 29. Eccentric cover plate. Detailed Implementation

[0040] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0041] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0042] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Please see Figures 1-3 As shown, Figure 1 This is a schematic diagram of the induction welding fixture for semi-steel cables according to an embodiment of the present invention; Figure 2 This is a schematic diagram showing the positions of the tail tube and the semi-steel workpiece in the positioning seat according to an embodiment of the present invention; Figure 3 This is a structural block diagram of an induction welding fixture for semi-steel cables according to an embodiment of the present invention.

[0044] This invention provides an induction welding fixture for semi-steel cables, comprising:

[0045] The coaxial positioning mechanism includes a base plate 1, a lifting slide 2 fixedly disposed at one end of the upper surface of the base plate 1, a straightening block 3 fixedly disposed on the side surface of the lifting slide 2 for straightening the semi-steel workpiece 8, the straightening block 3 having a clamping groove 4, and a positioning seat 5 fixedly disposed on the upper surface of the base plate 1 away from the lifting slide 2, wherein the positioning seat 5 has a plurality of countersunk holes 10 for accommodating the tail tube 9, and a through hole 11 coaxially connected with the countersunk holes 10 to enable the semi-steel workpiece 8 to be coaxially guided.

[0046] An induction welding mechanism includes an induction welding machine housing 7 and an induction welding head assembly 6 sleeved on the outside of the welding position between the tail pipe 9 and the semi-steel workpiece 8 and fixed on the induction welding machine housing 7.

[0047] The data acquisition component includes a laser line marker for detecting the coaxiality of the clamping groove 4 and the countersunk hole 10, a miniature pressure sensor array embedded in the inner wall of the countersunk hole 10 for detecting the pressure between the tail tube 9 and the inner wall of the countersunk hole 10, and an image acquisition device disposed on the side surface of the induction welding machine box 7 for real-time acquisition of image information of the semi-steel workpiece 8.

[0048] The end face tilt angle determination module is used to determine whether there is an angular tilt between the contact end face of the tail tube 9 and the semi-steel workpiece 8 based on the comparison result of the circumferential pressure balance index of the pressure of the inner wall of the tail tube 9 and the counterbore 10 and the preset balance index.

[0049] The coaxiality detection module, in response to the presence of angular tilt, determines whether the coaxiality of the clamping groove 4 and the countersunk hole 10 is qualified based on the horizontal distance between the vertical center lines of the clamping groove 4 and the countersunk hole 10.

[0050] The eccentricity moment correction module, in response to the coaxiality being qualified, is used to determine whether the gravity eccentricity moment of the semi-steel workpiece 8 is qualified based on the bending deflection amount of the semi-steel workpiece 8, and adjusts the straightening distance of the straightening block 3 based on the condition that the gravity eccentricity moment is not qualified.

[0051] The welding quality inspection module is used to determine whether the welding quality of the tail pipe 9 and the semi-steel workpiece 8 is qualified based on the circumferential spreading uniformity of the metallurgical bonding layer at the welding end face of the tail pipe 9 and the semi-steel workpiece 8, and to optimize the preset balance index based on the unqualified conditions.

[0052] Specifically, the array of miniature pressure sensors can consist of four or eight sensors, centered on the central axis of the countersunk hole 10. These sensors are embedded along the same axial circumferential surface of the inner wall of the countersunk hole 10 near the through hole 11, and are evenly distributed circumferentially at 90° or 45° angles. The sensor detection surface is flush with the inner wall of the countersunk hole 10 without any protrusions or depressions. Each miniature pressure sensor uses a circular or square patch-type pressure sensor with a diameter less than 3mm or a side length less than 3mm. A thin, wear-resistant metal sheet, preferably made of stainless steel or beryllium copper, is applied to the surface of the sensor detection surface. The curvature of the metal sheet matches that of the inner wall of the countersunk hole 10, and its dimensions precisely match and tightly fit the sensor detection surface. The specific model of the miniature pressure sensor is not limited.

[0053] Specifically, the circumferential pressure balance index of the pressure on the inner wall of the tailpipe 9 and the countersunk hole 10 is the difference between 1 and the ratio of the average pressure value of the micro pressure sensor array to the average absolute error, wherein the average absolute error refers to the average of the absolute values ​​of the differences between individual pressure values ​​and the arithmetic mean.

[0054] Please see Figure 4 As shown, it is a flowchart of an embodiment of the present invention for determining whether there is an angular tilt at the contact end face between the tail tube 9 and the semi-steel workpiece 8.

[0055] Specifically, the end face tilt angle determination module determines that the contact end face of the tail tube 9 and the semi-steel workpiece 8 has an angular tilt based on the comparison result that the circumferential pressure balance index is less than the preset balance index.

[0056] The end face tilt angle determination module determines that there is no angular tilt between the mating end faces of the tail tube 9 and the semi-steel workpiece 8 based on the comparison result that the circumferential pressure balance index is greater than or equal to the preset balance index.

[0057] Specifically, the preset equilibrium index is set to a value range of [0.8, 0.95], and in this embodiment of the invention, 0.9 is preferred.

[0058] Specifically, the laser line marker is magnetically attached to the welding fixture during use. A level is used to adjust the position of the laser line marker, ensuring the emitted laser line is vertical. The laser line marker is then moved horizontally, allowing it to pass through the vertical center sections of both the countersunk hole 10 and the clamping groove 4. Image information of the laser line is acquired at the same point, and the two images are pre-processed and then superimposed to determine the horizontal distance between the two laser lines. After testing, the laser line marker is removed from the welding fixture. The specific model of the laser line marker is not limited.

[0059] Specifically, under the condition of angular tilt, the coaxiality detection module determines that the coaxiality of the clamping groove 4 and the countersunk hole 10 is unqualified based on the comparison result that the horizontal distance is greater than a preset distance;

[0060] The coaxiality detection module determines that the coaxiality of the clamping groove 4 and the countersunk hole 10 is qualified based on the comparison result that the horizontal distance is less than or equal to the preset distance.

[0061] Specifically, the preset distance is set to a range of [0.02mm, 0.1mm], and in this embodiment of the invention, 0.05mm is preferred.

[0062] Specifically, the countersunk hole 10 serves as the rigid positioning reference for the tailpipe 9. The axis of the tailpipe 9 is determined by the axis of the countersunk hole 10, which is the reference axis for welding. The clamping groove 4 serves as the secondary alignment reference for the semi-steel workpiece 8. By clamping the semi-steel workpiece 8, the axis of the semi-steel workpiece 8 is aligned with the axis of the tailpipe 9, ensuring that the axis of the semi-steel workpiece does not deviate. If the two are not coaxial, the clamping groove 4 will forcibly pull the axis of the semi-steel workpiece towards its own axis, causing the axis of the semi-steel workpiece 8 and the tailpipe 9 to form an artificial spatial angle. Even if adjustments are made later, the misalignment cannot be eliminated at the root. As the coaxial positioning mechanism is used for longer periods, the precision of the device will inevitably decrease. Therefore, when it is determined that there is an angular tilt at the contact end face of the tailpipe 9 and the semi-steel workpiece 8, a coaxiality test is first performed to ensure the contact reference of the end face of the semi-steel workpiece 8 and the tailpipe 9.

[0063] Specifically, the coaxiality of the clamping groove 4 and the countersunk hole 10 is an indicator of the geometric accuracy of the tooling hardware assembly. If the coaxiality is not up to standard, it will directly cause the central axis of the semi-steel to be geometrically offset from the central axis of the tail tube 9 after the semi-steel is clamped, which will result in an angular tilt of the mating end face. However, if the coaxiality is up to standard, it can only eliminate the geometric positioning error of the tooling hardware, and cannot cover the deviation problem caused by the structural characteristics of the bent semi-steel itself. Because the bent semi-steel has an asymmetrical structure, its center of gravity will deviate from its theoretical axis. Even under the ideal hardware conditions where the coaxiality of the clamping groove 4 and the countersunk hole 10 is up to standard and there is no axial error, the offset of the center of gravity will still generate a continuous small overturning moment, which will act on the mating end face of the tail tube 9 and the semi-steel, inducing a small angular deflection of ≤1° on the end face. If only an angular tilt is detected at the mating end face without further verification of coaxiality, it is impossible to distinguish whether the tilt is caused by excessive coaxiality of the tooling or by the overturning moment due to the weight of the bent semi-steel, which can easily lead to misjudgment and misadjustment. Furthermore, even a slight angular tilt at the mating end face can directly cause uneven circumferential contact gaps: if the gap on the tilted side is too large, it is easy to cause insufficient solder filling, excessive wetting angle, and local cold solder joints. If the mating on the opposite side is too tight, it is easy to cause solder to overflow and the weld to be too thin in some areas, which directly destroys the circumferential uniformity of the circumferential weld and reduces the mechanical bonding force and electrical contact consistency.

[0064] Specifically, the process of extracting the bending deflection of the semi-steel workpiece 8 is as follows: taking the central axis of the countersunk hole 10 as the vertical reference line, the image information of the semi-steel workpiece 8 is collected in real time by an image acquisition device, the central axis of the bending section of the semi-steel workpiece 8 is extracted after the image information is preprocessed, the number of horizontal pixels of the endpoint of the bending section away from the welding end from the vertical reference line is determined, and the physical distance converted from the number of horizontal pixels is determined as the bending deflection.

[0065] Specifically, the physical distance is calculated by multiplying the number of horizontal pixels by the side length of a single pixel. The product is the physical distance. For example, if the number of horizontal pixels is 20 and the side length of a single pixel is 0.2mm, the corresponding physical distance is 4mm.

[0066] Specifically, under the condition that the coaxiality is qualified, the eccentricity correction module determines that the gravity eccentricity of the semi-steel workpiece 8 is qualified based on the judgment result that the bending deflection is less than or equal to the preset deflection.

[0067] Based on the determination result that the bending deflection amount is greater than the preset deflection amount, the eccentric torque correction module determines that the gravity eccentric torque of the semi-steel workpiece 8 is unqualified.

[0068] Specifically, the preset deflection amount is set to a range of [5cm, 10cm], and in this embodiment of the invention, 6mm is preferred.

[0069] Specifically, when the eccentric torque correction module is not qualified under the condition that the gravitational eccentric torque of the semi-steel workpiece 8 is not qualified, it determines the straightening distance of the straightening block 3 by adjusting the first distance adjustment coefficient based on the comparison result that the difference between the bending deflection amount and the preset deflection amount is less than or equal to the preset deflection difference.

[0070] The eccentric torque correction module determines the straightening distance of the straightening block 3 by adjusting the second distance adjustment coefficient based on the comparison result that the difference in deflection is greater than the preset difference in deflection.

[0071] Specifically, the preset deflection difference value is set to a range of [1cm, 5cm], and preferably 3cm in this embodiment of the invention. The first distance adjustment coefficient is set to a range of [0.85, 0.89], and preferably 0.88 in this embodiment of the invention. The second distance adjustment coefficient is set to a range of [0.89, 0.94], and preferably 0.92 in this embodiment of the invention.

[0072] Specifically, the straightening distance refers to the distance from the contact surface between the tailpipe 9 and the semi-steel workpiece 8 to the position where the straightening block 3 clamps the semi-steel workpiece 8. When the gravitational eccentric moment is too large, the self-weight of the bent section of the semi-steel workpiece 8 will generate a significant overturning moment on the contact surface between the tailpipe 9 and the semi-steel workpiece 8, causing the end face to tilt at an angle. Reducing the straightening distance of the straightening block 3, so that the point where the straightening block 3 clamps the semi-steel cable is closer to the contact surface, and the lever arm is shorter. Without changing the overall posture of the semi-steel workpiece 8, only the end face of the semi-steel workpiece 8 is slightly flattened to counteract the local tilt caused by the gravity of the bent section.

[0073] Specifically, the method for determining the circumferential spreading uniformity of the metallurgical bonding layer on the welded end face of the tailpipe 9 and the semi-steel workpiece 8 is as follows: select several detection positions at equal angles along the circumference of the metallurgical bonding layer, obtain the echo amplitude of the corresponding position by ultrasonic scanning, and determine the circumferential spreading uniformity as the percentage of the standard deviation and the average value of several echo amplitudes. For example, if a single-point ultrasonic scanning device is used, and one scan covers a 60° angle range, then 6 circumferential scans are required, and 6 detection positions at equal angles must be selected.

[0074] Specifically, when the welding end face of the tailpipe 9 and the semi-steel workpiece 8 is not tilted at an angle, the circumferential gap of the welding end face is uniform, and the metallurgical bonding layer is in an ideal state of circumferential continuity, equal width, density and no defects. The propagation and reflection conditions of ultrasonic waves at each position in the circumferential direction are highly consistent. Therefore, the ultrasonic echo amplitude at each position is basically equal and the amplitude fluctuation is minimal. When there is an angle tilt of the welding end face, it will directly lead to uneven width of the circumferential gap of the weld, which in turn will cause problems such as uneven circumferential thickness, insufficient local fusion and significant differences in density of the metallurgical bonding layer. As a result, the reflection interface, propagation path and attenuation degree of ultrasonic waves at different circumferential positions will change significantly, which is manifested as large fluctuations in the echo amplitude at each position.

[0075] Specifically, the welding quality inspection module determines that the welding quality between the tail pipe 9 and the semi-steel workpiece 8 is unqualified based on the comparison result that the circumferential spreading uniformity is greater than the preset uniformity.

[0076] The welding quality inspection module determines that the welding quality of the tail pipe 9 and the semi-steel workpiece 8 is qualified based on the comparison result that the circumferential spreading uniformity is less than or equal to the preset uniformity.

[0077] Specifically, the preset uniformity is set to a range of [3%, 8%], and preferably 5% in this embodiment of the invention.

[0078] Specifically, under the condition that the welding quality of the tail pipe 9 and the semi-steel workpiece 8 is unqualified, the welding quality detection module sets several index correction coefficients to optimize the preset uniformity index based on the uniformity difference between the circumferential spreading uniformity and the preset uniformity, and the comparison result of the preset uniformity difference.

[0079] Specifically, the welding quality inspection module determines to increase the preset uniformity index by a first index correction coefficient based on the comparison result that the uniformity difference is greater than or equal to the preset uniformity difference.

[0080] Based on the comparison result that the uniformity difference is less than the preset uniformity difference, the welding quality inspection module determines to increase the preset balance index by a second index correction coefficient.

[0081] Specifically, the preset uniformity difference is set to a range of [2%, 5%], and preferably 3% in this embodiment of the invention; the first exponential correction coefficient is set to a range of [1.05, 1.08], and preferably 1.06 in this embodiment of the invention; the second exponential correction coefficient is set to a range of [1.02, 1.04], and preferably 1.03 in this embodiment of the invention.

[0082] Specifically, the way to optimize the preset equilibrium index by the index correction coefficient is that the product of the preset equilibrium index and the corresponding index correction coefficient is the optimized preset equilibrium index.

[0083] Please see Figure 5 As shown, it is a flowchart of an embodiment of the present invention for induction welding of semi-steel cables.

[0084] The present invention provides an induction welding method for semi-steel cables, comprising:

[0085] Step S1: Based on the circumferential pressure balance index of the pressure between the tail tube 9 and the inner wall of the counterbore 10, and the comparison result with the preset balance index, determine whether there is an angular tilt at the contact end face of the tail tube 9 and the semi-steel workpiece 8.

[0086] Step S2: Under the condition that there is an angular inclination at the contact end face of the tail tube 9 and the semi-steel workpiece 8, determine whether the coaxiality of the clamping groove 4 and the countersunk hole 10 is qualified based on the horizontal distance between the vertical center line of the clamping groove 4 and the countersunk hole 10.

[0087] Step S3: Under the condition that the coaxiality of the clamping groove 4 and the countersunk hole 10 is qualified, determine whether the gravity eccentricity moment of the semi-steel workpiece 8 is qualified based on the bending deflection amount of the semi-steel workpiece 8, and adjust the straightening distance of the straightening block 3 based on the condition that the gravity eccentricity moment is not qualified.

[0088] Step S4: Weld the tail pipe 9 and the semi-steel workpiece 8. Based on the circumferential spreading uniformity of the metallurgical bonding layer at the weld end face of the tail pipe 9 and the semi-steel workpiece 8, determine whether the welding quality of the tail pipe 9 and the semi-steel workpiece 8 is qualified, and optimize the preset balance index based on the unqualified condition.

[0089] Specifically, the welding process of the welding fixture is as follows: The tail tube 9 is placed into the countersunk hole 10 of the positioning seat 5, and the semi-steel workpiece 8 is inserted into the tail tube 9. The outer conductor of the semi-steel workpiece 8 is flush with the end face of the tail tube 9 against the end face of the countersunk hole 10 of the positioning seat 5. The dielectric layer of the semi-steel workpiece 8 extends into the through hole 11 of the positioning seat 5. Then, the lifting slide 2 and the straightening block 3 are adjusted to accommodate different semi-steel bending shapes for secondary straightening. After adjustment, induction welding is used to set the welding time and temperature to complete the welding of the tail tube 9 and the semi-steel workpiece 8. The diameter of the countersunk hole 10 matches the outer diameter of the tail tube 9, and the diameter of the through hole 11 matches the outer diameter of the dielectric layer of the semi-steel workpiece 8.

[0090] Please see Figures 6-8 As shown, Figure 6 This is a schematic diagram of the semi-steel end-face cutting device according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the cutter head structure according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the blade assembly according to an embodiment of the present invention.

[0091] The present invention provides a semi-steel end-face cutting device, comprising:

[0092] The power transmission mechanism includes a housing 14 with a controller 15 on the outside, a stepper motor mounting base 19 inside the housing 14, a stepper motor 20 fixedly mounted on the stepper motor mounting base 19, the output shaft of the stepper motor 20 being rigidly connected to the input shaft of a speed gearbox 18 via a coupling 21, the output end of the speed gearbox 18 being connected to a cutter head 16, and a feed port 22 being provided at the end of the cutter head 16 away from the speed gearbox 18;

[0093] The cutting mechanism includes a cutting head 16, which includes an outer shaft 23 and an inner shaft 24. The inner shaft 24 is coaxially nested inside the outer shaft 23. A blade assembly 26 is provided on the side of the inner shaft 24 near the feed port 22. The blade assembly 26 includes a tool holder 28 fixedly mounted on the front end of the inner shaft 24 for synchronous rotation with the inner shaft 24, a blade 27 mounted on the tool holder 28 for cutting the outer conductor of the semi-steel cable, an eccentric cover plate 29 sleeved on the inner shaft 24, located outside the tool holder 28, and cooperating with the tool holder 28 through an eccentric structure to limit the movement trajectory of the blade 27, and a length limiting screw 25 located on the front end of the inner shaft 24 to limit the feed depth of the semi-steel cable.

[0094] Specifically, the gearbox 18 adopts a 1:4 transmission ratio design, and its output end is mechanically connected to the outer shaft 23 and the inner shaft 24 of the cutter head, respectively, to achieve differential motion with the outer shaft of the cutter head rotating 4 revolutions and the inner shaft of the cutter head rotating 1 revolution.

[0095] Specifically, the feed port 22 is coaxially aligned with the center hole of the inner shaft 24 of the cutter head.

[0096] In practice, before welding the semi-steel workpiece 8 to the tail tube 9, a cutting process is required. First, a semi-steel end-face cutting device is used to cut off a portion of the seamless copper tube outer conductor of the semi-steel cable, flattening the end face of the semi-steel cable to obtain the semi-steel workpiece, which is then welded to the tail tube 9. The specific flattening process is as follows: the semi-steel cable is placed into the feed port 22 and pushed forward to the position of the length limit screw 25. Then, the stepper motor 20 rotates and passes through a 1:4 speed gearbox. The outer shaft 23 of the cutter head rotates four times, and the inner shaft 24 of the cutter head rotates one time. This can reduce the instantaneous cutting amount of the cutter and extend the tool life. The cutter holder 28 and the blade 27 rotate with the inner shaft 24 of the cutter head in the eccentric cover plate 29. The eccentricity is designed according to the thickness of the copper tube of the semi-steel cable, and back and forth cutting is performed. When the number of rotations set by the stepper motor 20 is reached, the rotation stops. After the product is taken out, the outer conductor is manually peeled off to obtain the semi-steel workpiece 8 with the flattened end face.

[0097] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. An induction welding fixture for semi-steel cables, characterized in that, include: A coaxial positioning mechanism includes a base plate, a lifting slide table disposed at one end of the upper surface of the base plate, a straightening block disposed on the side surface of the lifting slide table for straightening a semi-steel workpiece, the straightening block being provided with a clamping groove, and a positioning seat disposed at one end of the upper surface of the base plate away from the lifting slide table. The data acquisition component includes a laser line marker for detecting the coaxiality of the clamping groove and the countersunk hole, a miniature pressure sensor array for detecting the pressure between the tail tube and the inner wall of the countersunk hole, and an image acquisition device for acquiring image information of the semi-steel workpiece in real time. The end face tilt angle determination module is used to determine whether there is an angular tilt at the contact end face of the tail tube and the semi-steel workpiece based on the comparison result of the circumferential pressure balance index of the pressure between the tail tube and the inner wall of the counterbore and the preset balance index. A coaxiality detection module, which responds to the presence of angular tilt, determines whether the coaxiality of the clamping groove and the countersunk hole is qualified based on the horizontal distance between the vertical center lines of the clamping groove and the countersunk hole. The eccentricity correction module, in response to the coaxiality being qualified, is used to determine whether the gravitational eccentricity of the semi-steel workpiece is qualified based on the bending deflection of the semi-steel workpiece, and adjusts the straightening distance of the straightening block based on the condition that the gravitational eccentricity is not qualified. The welding quality inspection module is used to determine whether the welding quality of the tail pipe and the semi-steel workpiece is qualified based on the circumferential spreading uniformity of the metallurgical bonding layer at the weld end face of the tail pipe and the semi-steel workpiece, and to optimize the preset equilibrium index based on the unqualified conditions.

2. The induction welding fixture for semi-steel cables according to claim 1, characterized in that, The positioning seat has several countersunk holes for accommodating the tail tube, and through holes coaxially connected to the countersunk holes to enable coaxial guidance of the semi-steel workpiece.

3. The induction welding fixture for semi-steel cables according to claim 2, characterized in that, The end face tilt angle determination module determines that the contact end face between the tail tube and the semi-steel workpiece has an angular tilt based on the comparison result that the circumferential pressure balance index is less than the preset balance index.

4. The induction welding fixture for semi-steel cables according to claim 3, characterized in that, The coaxiality detection module determines that the coaxiality of the clamping groove and the countersunk hole is qualified based on the comparison result that the horizontal distance is less than or equal to a preset distance when there is angular tilt.

5. The induction welding fixture for semi-steel cables according to claim 4, characterized in that, Under the condition that the coaxiality is qualified, the eccentricity correction module determines that the gravity eccentricity of the semi-steel workpiece is unqualified based on the judgment result that the bending deflection is greater than the preset deflection.

6. The induction welding fixture for semi-steel cables according to claim 5, characterized in that, When the eccentricity moment correction module is not up to standard due to gravity eccentricity of the semi-steel workpiece, it determines the straightening distance of the straightening block to be adjusted by a first distance adjustment coefficient based on the comparison result that the difference between the bending deflection amount and the preset deflection amount is less than or equal to the preset deflection difference. The eccentric torque correction module determines the straightening distance of the straightening block to be adjusted by a second distance adjustment coefficient based on the comparison result that the difference in deflection is greater than the preset difference in deflection.

7. The induction welding fixture for semi-steel cables according to claim 6, characterized in that, The circumferential spreading uniformity is determined based on the echo amplitude of the circumferential ultrasonic scan of the metallurgical bonding layer between the tailpipe and the semi-steel workpiece.

8. The induction welding fixture for semi-steel cables according to claim 7, characterized in that, The welding quality inspection module determines that the welding quality of the tailpipe and the semi-steel workpiece is unqualified based on the comparison result that the circumferential spreading uniformity is greater than the preset uniformity.

9. The induction welding fixture for semi-steel cables according to claim 8, characterized in that, The welding quality inspection module, under the condition that the welding quality of the tail pipe and the semi-steel workpiece is unqualified, sets several index correction coefficients to optimize the preset uniformity index based on the uniformity difference between the circumferential spreading uniformity and the preset uniformity, and the comparison result of the preset uniformity difference.

10. A welding method using the induction welding fixture for semi-steel cables as described in any one of claims 1-9, characterized in that, include: Based on the circumferential pressure balance index of the pressure between the tail tube and the inner wall of the counterbore, the comparison result with the preset balance index determines whether there is angular tilting at the contact end face of the tail tube and the semi-steel workpiece. Under the condition that there is an angular inclination at the contact end face of the tail tube and the semi-steel workpiece, the coaxiality of the clamping groove and the countersunk hole is determined based on the horizontal distance between the vertical center lines of the clamping groove and the countersunk hole. Under the condition that the coaxiality of the clamping groove and the countersunk hole is qualified, the gravitational eccentricity of the semi-steel workpiece is determined based on the bending deflection of the semi-steel workpiece, and the straightening distance of the straightening block is adjusted based on the condition that the gravitational eccentricity is not qualified. The tailpipe and the semi-steel workpiece are welded together. Based on the circumferential spreading uniformity of the metallurgical bonding layer at the weld end face of the tailpipe and the semi-steel workpiece, the welding quality of the tailpipe and the semi-steel workpiece is determined to be qualified. The preset balance index is optimized based on the unqualified condition.

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