AFP wire half-automatic stranding machine and stranding control method thereof

Abstract

This invention provides a semi-automatic stranding machine for AFP conductors and its stranding control method, relating to the technical field of wire harness processing equipment. It includes a frame, a stranding turntable with multiple wire passage channels, and a drive assembly. The core improvement lies in the fact that the passive un-torsion bearing assembly corresponds one-to-one with the wire passage channels, and the flexible tension clamping mechanism is integrated inside the bearing. Specifically, a fixed housing is fixed to the inner ring of the bearing body, and its inner wall has radial grooves, housing steel balls and silicone tubing. A rotating ferrule drives the steel balls radially to squeeze the silicone tubing to grip the conductors. Multiple conductors are converged into a single strand by a wire-gathering component and pulled by a material-pulling servo assembly. This invention integrates un-torsion and tension clamping into the inner ring of the bearing, resulting in a compact structure. The silicone tubing provides flexible frictional tension, avoiding damage to the wires from metal clamping.

Description

Technical Field

[0001] This invention relates to the field of wire harness processing equipment technology, and in particular to a semi-automatic stranding machine suitable for AFP conductors (aluminum foil polyester composite shielded insulated conductors). Background Technology

[0002] In the fabrication of AFP conductors (such as multi-core shielded wire harnesses), the stranding process is a crucial step in ensuring the electrical performance and mechanical strength of the wire harness. However, existing stranding equipment has the following significant drawbacks: 1. Traditional untorsion mechanisms (such as untorsion gearboxes) and tension clamping mechanisms are usually two separate physical components, installed in series on the inlet side. This not only results in an excessively long axial dimension of the entire machine, occupying a large space, but also makes the wire threading path tortuous, increasing the risk of scratching the thin insulation layer of the AFP wires.

[0003] 2: For multi-channel stranding, if multiple conductors share a single untwisting mechanism, the degree of torsional stress release for each conductor will vary, resulting in loose, twisted, or unevenly pitched wire bundles after stranding.

[0004] 3: External tensioning mechanisms often use metal pressure rollers or spring sheets to apply pressure to the conductor. This rigid contact can easily damage the fragile insulation layer or the metallized shielding layer on the surface of the AFP conductor.

[0005] 4. Adjusting the pitch of the hinge usually relies on changing the gear or pulley to change the transmission ratio. This is complicated, time-consuming, and labor-intensive, and cannot meet the needs of modern manufacturing for rapid changeover of small batches and multiple varieties.

[0006] Therefore, there is an urgent need for a semi-automatic AFP conductor stranding machine with a compact structure, good unwinding synchronization, gentle tension control, and adjustable pitch, as well as its stranding control method. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention aims to provide a semi-automatic stranding machine for AFP conductors and its stranding control method. The unwinding and tension clamping are integrated into the inner ring of the bearing, resulting in a compact structure. The use of a silicone hose to provide flexible frictional tension avoids damage to the wire from metal clamps. Furthermore, the pitch is infinitely adjustable through a feed servo component, thus enabling rapid changeover for various AFP conductor specifications.

[0008] This invention provides the following technical solution: This invention provides a semi-automatic stranding machine for AFP conductors, including a frame, a stranding turntable, a turntable drive assembly, a passive untorsion bearing assembly, and a flexible tension clamping mechanism.

[0009] The stranding turntable is rotatably mounted on the frame and has multiple sets of wire passages distributed around its rotation center.

[0010] The turntable drive assembly is a drive motor mounted on the frame. The drive end of the drive motor is equipped with an external gear for meshing with the external gear ring of the stranded wire turntable, which is used to drive the stranded wire turntable to rotate.

[0011] The passive untorsion bearing assembly corresponds one-to-one with the wire passage. Each passive untorsion bearing assembly includes a bearing body, the outer ring of which is fixed inside the wire passage.

[0012] The flexible tension clamping mechanism is integrated into the passive untorsion bearing assembly, comprising a fixed housing, a silicone hose, a steel ball, and a rotating ferrule. The fixed housing is fixedly connected to the inner ring of the bearing body, has a central channel for the AFP wire to pass through, and its inner wall has at least three sets of radial grooves along the circumference. The silicone hose is fixedly disposed within the central channel of the fixed housing, and the AFP wire passes through the inner hole of the silicone hose. The steel ball is housed within the radial grooves of the fixed housing. The rotating ferrule is fitted onto the outer circumference of the fixed housing and driven by a threaded engagement to push the steel ball radially to compress the silicone hose, causing it to cover the wire.

[0013] Furthermore, it also includes a wire gathering component, a material pulling servo assembly, and a controller. The wire gathering component is located at the output end of the stranding turntable and is used to gather multiple stranded wires into a single strand bundle. The material pulling servo assembly is used to pull the bundle. The controller is configured to control the material pulling servo assembly to pull a fixed distance per revolution of the turntable. By setting up the wire gathering component, multiple dispersed stranded wires can be gathered into a single round bundle, facilitating subsequent pulling and take-up. The material pulling servo assembly, in conjunction with the controller, realizes digital control of the stranding pitch, where the pitch P is defined as: the distance the wire travels axially when it rotates around the stranding turntable once. In digital control, this relationship is simplified to: P = number of revolutions of the turntable / displacement of the material pulling servo. As long as the controller accurately controls the material pulling servo to move a certain distance per revolution of the turntable, digital control of the pitch can be achieved.

[0014] Furthermore, the bearing body is a low-friction ball bearing, with its inner ring fixedly connected to the end face of the fixed housing via a rigid connecting member, and the outer ring axially limited and circumferentially fixed to the inner wall of the wire passage via an elastic retaining ring and a pressure cap. The frictional holding torque between the silicone hose and the AFP wire is greater than the starting torque of the bearing body and less than the torsional yield limit of the AFP wire itself, so that the torsional stress generated by the wire during the stranding process drives the inner ring to deflect in the opposite direction relative to the outer ring to release the torsional strain.

[0015] Furthermore, the inner wall of the fixed housing has three sets of radial channels, evenly distributed at 120° intervals around the circumference. Using three sets of 120° evenly distributed channels ensures that the squeezing force of the steel ball on the silicone hose is evenly distributed in the circumferential direction, thereby balancing the frictional tension on the wire, preventing eccentricity or vibration of the wire during stranding, and improving the stranding quality.

[0016] Furthermore, the rotating sleeve has an inner conical surface, which, during screwing, presses against the steel ball, causing it to displace inward along the radial channel. By utilizing the inner conical surface to convert the axial screwing motion of the rotating sleeve into the radial displacement of the steel ball, the structure is simple and reliable, easy to operate, and can precisely control the extrusion pressure on the silicone hose, thereby precisely controlling the tension.

[0017] Furthermore, two sets of first ceramic guide sleeves are installed at both ends of each wire passage. By installing ceramic guide sleeves at the inlet and outlet of the wire passage, the high hardness and low coefficient of friction of the ceramic guide sleeves can effectively reduce the friction between the wire and the metal passage wall, prevent the wire insulation layer from being scratched, and reduce the resistance to wire pulling.

[0018] Furthermore, the hub assembly includes a bracket mounted on the rack and a second ceramic guide sleeve mounted on the bracket. The hub assembly also employs a ceramic guide sleeve to further protect the wire harness from scratches during the convergence process, ensuring the surface quality of the wire harness.

[0019] Furthermore, the material pulling servo component is an electric gripper driven by a linear module, with unidirectional traction along the wire harness axis. Using an electric gripper in conjunction with a linear module provides stable and precise traction force, ensuring consistent stranding pitch, and offering a high degree of automation, reducing manual intervention.

[0020] On the other hand, the present invention provides a semi-automatic stranding control method for AFP conductors, which uses the above-mentioned stranding machine and includes the following steps: S1: Pass the multiple AFP wires through the silicone tubing inside the passive untorsion bearing assembly one by one. S2: The threaded rotating ferrule is screwed in, and frictional tension is established by squeezing the silicone tubing with a steel ball; S3: Start the turntable drive assembly. The twisted wire turntable rotates, causing multiple wires to twist around the central axis. At the same time, the inner ring of the bearing body rotates synchronously with the twisting of the wires to achieve untwisting. S4: The multiple stranded wires are gathered into a single wire bundle by the wire gathering component, and the wire pulling servo component pulls the wire bundle at a fixed distance per revolution.

[0021] In this application, the torque reduction is not achieved by relying on the forced reverse drive of the active gear system, but by passive torque reduction using the controllable sliding boundary of the flexible friction interface. Specifically, the rotating ferrule elastically compresses the silicone tubing against the outer sheath of the AFP wire through the inner conical surface and steel ball, forming a controllable friction braking torque. During the winding process, the wire generates torsional stress around its own axis. This torsional stress is transmitted to the fixed housing, which is rigidly connected to the inner ring of the bearing body, through the friction interface. The bearing body is a low-friction ball bearing. Under the action of torsional stress, its inner ring generates a small angular displacement relative to the fixed outer ring in the opposite direction of the winding, thereby releasing the torsional strain of the wire. This is the torque reduction effect. The selected bearing body is preferably a miniature low-friction ball bearing, specifically a C3 clearance deep groove ball bearing or a miniature crossed roller bearing, with a rated starting torque of no more than 0.01 N·m, to ensure that the torsional stress preferentially drives the inner ring to rotate rather than accumulates in the wire body.

[0022] The beneficial effects of this invention are: 1: By integrating the flexible tension clamping mechanism into the inner ring of the passive untorsion bearing assembly, discrete components are eliminated, the axial length of the entire machine is significantly shortened, the wire threading path is minimized, and the risk of wire scratching is reduced. 2: The fixed housing rotates synchronously with the inner ring of the bearing body. As the wire untwistes, it is subjected to frictional tension from the silicone hose. The dynamic response is fast and the tension fluctuation is small, which ensures the uniformity of the twisting pitch. 3: Using silicone tubing as the contact medium, radial force is uniformly transmitted through steel balls, avoiding the hard squeezing and scratching of the insulation or shielding layer of the AFP wire by the metal pressure roller; 4. Each conductor has an independent untwisting and tension unit, which does not interfere with each other, making it particularly suitable for stranding high-precision wire harnesses such as multi-channel AFP conductors; 5: The twisting pitch is directly converted into the feed distance per revolution of the material pulling servo, which can be steplessly adjusted through the controller. There is no need to replace the mechanical transmission parts, resulting in extremely high changeover efficiency. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a three-dimensional schematic diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the stranded wire turntable and the turntable drive assembly of the present invention; Figure 3 yes Figure 2 Mid-section sectional view; Markings in the diagram: 1. Frame; 2. Stranded wire turntable; 3. Turntable drive assembly; 4. Feeding servo assembly; 5. Passive un-torsion bearing assembly; 6. Flexible tension clamping mechanism; 7. First ceramic guide sleeve; 8. Controller; 9. Cable assembly; 100. AFP wire; 51. Bearing body; 61. Fixing housing; 62. Silicone hose; 63. Steel ball; 64. Rotating ferrule; 91. Bracket; 92. Second ceramic guide sleeve. Detailed Implementation

[0024] Example 1: like Figures 1 to 3 As shown in the figure, this embodiment provides a semi-automatic stranding machine suitable for processing 6-core AFP shielded wire harnesses.

[0025] The frame 1 is welded from rectangular steel tubing and has leveling feet at the bottom. The stranding turntable 2 is supported above the frame 1 by precision crossed roller bearings, and six sets of wire guide channels are distributed around the center of the turntable. The turntable drive assembly 3 uses a servo motor, with an external gear mounted on the motor shaft end, which meshes with the external gear ring on the outer circumference of the stranding turntable 2 to form a reduction transmission, ensuring smooth rotation of the turntable and controllable angular displacement.

[0026] For the six sets of cable guide channels, there are six corresponding passive anti-torsion bearing assemblies 5. Each assembly uses a low-friction ball bearing as the bearing body 51, preferably a C3 clearance deep groove ball bearing, whose outer ring is fixed to the inner wall of the cable guide channel by an elastic retaining ring and a pressure cap. A flexible tension clamping mechanism 6 is integrated inside the bearing, specifically as follows: The fixed housing 61 is rigidly locked to the inner ring end face of the bearing body 51 via a locating key, end face cap screw, or set screw, or a combination thereof. This allows the frictional torque between the silicone hose 62 and the wire to be directly transmitted to the inner ring. The outer ring of the bearing body 51 is axially positioned and circumferentially fixed to the inner wall of the wire passage via an elastic retaining ring and a cap, thus forming a passive rotational torque-reducing unit with the bearing as the pivot. Three sets of radial grooves are evenly distributed along the circumference of the inner wall of the fixed housing 61.

[0027] The silicone tube 62 is a high-temperature resistant silicone tube with a Shore hardness of A60 and a wall thickness of 2mm. It is fixed to the central channel of the fixed housing 61 by adhesive bonding.

[0028] Steel ball 63 is a GCr15 steel ball with a diameter of 8mm, which is housed in a radial channel.

[0029] The rotating ferrule 64 is screwed onto the outer periphery of the fixed housing 61 via a trapezoidal thread, and its inner hole has a 15° inner conical surface. When tightened, the inner conical surface pushes the steel ball to radially compress the silicone hose 62, causing it to elastically deform and cover the outer sheath of the AFP wire 100.

[0030] Each set of wire passages has a first ceramic guide sleeve 7 press-fitted at its inlet and outlet. The wire outlet of the stranded wire turntable 2 is provided with a wire gathering component 9, including a bracket 91 and a second ceramic guide sleeve 92 mounted on the bracket, which is used to gather 6 dispersed stranded wires into a round wire bundle 200.

[0031] The material feeding servo component 4 uses an electric gripper driven by a linear module. The controller 8 is a PLC, which is connected to the turntable servo motor and the material feeding servo component via signal transmission. The controller 8 has a built-in electronic gear algorithm configured such that when the turntable rotates one revolution, the feed distance S of the material feeding servo component is 25mm (i.e., the twisting pitch is 25mm).

[0032] Work process: Threading: Thread the 6 AFP wires through the 6 sets of first ceramic guide sleeves 7, silicone tubing 62 and second ceramic guide sleeves 92 respectively, and hold them with electric grippers.

[0033] Establishing tension: Manually tighten the 6 rotating sleeves 64 until the resistance feels moderate, thus establishing the initial frictional tension.

[0034] Stranding: Start the equipment, and the turntable drive assembly 3 drives the stranding turntable 2 to rotate at 30 r / min. The 6 wires are stranded around the central axis, and at the same time, the inner ring of the bearing body 51 rotates synchronously with the twisting of the wires to release torsional stress (passive untwisting).

[0035] Traction: Controller 8 controls the material pulling servo component 4 to pull the wire harness at a speed of 25mm / r.

[0036] In this application, the controllable frictional tension application function of the silicone hose, steel ball, and rotating ferrule combination is coaxially integrated with the passive untorsion rotating pair of the inner ring of the low-friction ball bearing. The tension mechanism and the untorsion mechanism share the same rotation axis and are nested in the same radial space, so that each wire has an independent, synchronous, and compact untorsion and tension unit.

[0037] Example 2: This embodiment provides a control method based on the device described in Embodiment 1, specifically including the following steps: S1: Pass the 6 AFP wires 100 sequentially through the guide hole at the inlet end of the frame 1 and the silicone hose 62 inside the passive untorsion bearing assembly 5 until the wire ends extend out of the outlet end of the stranding turntable 2.

[0038] S2: The operator uses a tool to screw in the rotating ferrule 64. The threaded insertion of the ferrule 64 generates axial displacement, which, through the inner conical surface, presses against the steel ball 63, causing it to move inward along the radial groove, forcing the silicone hose 62 to undergo elastic deformation. The inner wall of the silicone hose 62 tightly adheres to the outer sheath of the AFP lead wire 100, forming a controllable frictional braking force. The operator adjusts the tension to a state where the lead wire does not slip or sag by observing the feel of the lead wire being pulled.

[0039] S3: Controller 8 receives the start command and simultaneously outputs pulse signals to the turntable drive assembly 3 and the material pulling servo assembly 4. The turntable drive assembly 3 drives the stranding turntable 2 to rotate, causing the six wires to revolve around the central axis, forming a stranded structure. During the stranding process, the wires are subjected to axial resistance from the material pulling servo assembly 4, generating a torsional tendency. This torsional force is transmitted to the inner ring of the bearing body 51, driving the inner ring to rotate relative to the fixed outer ring, thereby causing the wires to rotate in the opposite direction around their own axis, releasing the torsional stress generated by stranding (i.e., passive untorsion).

[0040] S4: The six stranded wires enter the wire-gathering component 9 and are gathered into a single-strand wire bundle under the constraint of the second ceramic guide sleeve 92. The controller 8 performs electronic gear synchronization: using the number of pulses fed back by the turntable encoder as the numerator and the number of pulses received by the material-pulling servo encoder as the denominator, the ratio is maintained. When the turntable rotates one revolution (360°), the controller 8 precisely controls the material-pulling servo component 4 to move forward 25mm, thus completing one pitch of stranding.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A semi-automatic stranding machine for AFP conductors, characterized in that, include: Rack (1); The stranding turntable (2) is rotatably mounted on the frame (1) and has multiple sets of wire passages distributed around its rotation center; The turntable drive assembly (3) is a drive motor mounted on the frame (1). The drive end of the drive motor is equipped with an external gear for meshing with the external gear ring of the stranded turntable (2) to drive the stranded turntable (2) to rotate. The passive untorsion bearing assembly (5) corresponds one-to-one with the wire passage. Each passive untorsion bearing assembly (5) includes a bearing body (51), the outer ring of which is fixed in the wire passage. The flexible tension clamping mechanism (6) is integrated into the interior of the passive untorsion bearing assembly (5) in a one-to-one correspondence, including: A fixed housing (61) is fixedly connected to the inner ring of the bearing body (51). The fixed housing (61) has a central channel through which the AFP wire (100) passes, and at least three sets of radial grooves are opened on the inner wall in the circumferential direction. A silicone hose (62) is fixedly installed in the central channel of the fixed housing (61), and an AFP wire (100) passes through the inner hole of the silicone hose (62); The steel ball (63) is housed in the radial channel of the fixed housing (61); A rotating sleeve (64) is fitted around the outer periphery of the fixed housing (61) and driven by a threaded engagement to push the steel ball (63) to radially compress the silicone hose (62) so that it covers the wire.

2. The semi-automatic stranding machine for AFP conductors according to claim 1, characterized in that: Also includes: A wire gathering component (9) is located at the output end of the stranded wire turntable (2) and is used to gather multiple stranded wires into a single strand bundle. A material pulling servo assembly (4) is used to pull the wire harness (200). The controller (8) is configured to control the material pulling servo assembly (4) to pull a fixed distance for each rotation of the turntable.

3. The semi-automatic AFP conductor stranding machine according to claim 1, characterized in that, The bearing body (51) is a low-friction ball bearing. Its inner ring is fixedly connected to the end face of the fixed housing (61) through a rigid connecting member. The outer ring is axially limited and circumferentially fixed to the inner wall of the wire passage through an elastic retaining ring and a pressure cap. The frictional holding torque between the silicone hose (62) and the AFP wire (100) is greater than the starting torque of the bearing body (51) and less than the torsional yield limit of the AFP wire (100) itself. This causes the torsional stress generated by the wire during the stranding process to drive the inner ring to deflect in the opposite direction relative to the outer ring to release the torsional strain.

4. The semi-automatic stranding machine for AFP conductors according to claim 1, characterized in that: The number of radial channels opened on the inner wall of the fixed housing (61) is three sets, which are evenly distributed along the circumference at 120°.

5. The semi-automatic stranding machine for AFP conductors according to claim 1, characterized in that: The rotating sleeve (64) has an inner conical surface. When it is screwed in, the inner conical surface presses against the steel ball (63) and moves it inward along the radial channel.

6. The semi-automatic stranding machine for AFP conductors according to claim 1, characterized in that: Two sets of first ceramic guide sleeves (7) are also installed at both ends of each set of cable passages.

7. The semi-automatic AFP conductor stranding machine according to claim 2, characterized in that: The hub component (9) includes a bracket (91) mounted on the frame (1) and a second ceramic guide sleeve (92) mounted on the bracket.

8. The semi-automatic AFP conductor stranding machine according to claim 2, characterized in that: The material pulling servo component (4) is an electric gripper driven by a linear module, and the pulling direction is unidirectional pulling along the wire harness axis.

9. A method for controlling the stranding of AFP conductors in a semi-automatic stranding machine, using the AFP conductor semi-automatic stranding machine as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1: Pass the multiple AFP wires (100) through the silicone tubing (62) inside the passive untorsion bearing assembly (5) one by one. S2: The threaded rotating ferrule (64) is screwed in, and the frictional tension is established by squeezing the silicone hose (62) through the steel ball (63); S3: Start the turntable drive assembly (3), the twisted wire turntable (2) rotates and drives multiple wires to twist around the central axis, while the inner ring of the bearing body (51) rotates synchronously with the twist of the wires to achieve untwisting; S4: The stranded wires are gathered into a single wire bundle by the wire gathering component (9), and the material pulling servo component (4) pulls the wire bundle (200) at a fixed distance per revolution.

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