Back-twist device for multi-core cables

Abstract

A multi-core cable detwisting device is provided, which simultaneously removes the sheath and corrects the twisted shape of the wire, and can correct the twisted shape better than the prior art. The multi-core cable detwisting device (1) comprises: a holding fixture (11) for holding the non-front end portion (5B) of the sheath (5), a holding fixture (26) for holding the front end portion (5A) of the sheath, a pulling device (30) for pulling out the front end portion (5A) of the sheath by moving the holding fixture (26), a rotating device (40) for rotating the holding fixture (26), and a control device (50) for controlling the pulling device (30) and the rotating device (40). The control device (50) is configured to execute a first control and a second control, wherein the first control pulls out the front end portion (5A) of the sheath without rotating it, and the second control pulls out the front end portion (5A) of the sheath while rotating it.

Description

Technical Field

[0001] The invention relates to a detwisting device for a multi-core cable, which pulls out a sheath at the front end of the multi-core cable and corrects the twisting state of the wires in the sheath. Background Art

[0002] A multi-core cable is known, comprising multiple wires and a sheath covering these wires. The multi-core cable can be processed by forming a deep cut at the front end of the sheath, or by removing the front end of the sheath to expose the front ends of the wires. Subsequently, for example, a terminal can be crimped onto the front ends of the wires. However, if a twist remains in the wires after the front ends of the sheath are removed, subsequent processing of the wires cannot be performed properly. Therefore, a device for correcting the twist in the wires has been proposed.

[0003] Japanese Utility Model Publication No. 3-120622 discloses a wire detwisting device that simultaneously detwists wires and removes their jackets. The device comprises a retaining member that holds the non-stripping portion of a multi-core cable's jacket, and a gripping unit that grips the jacket to be stripped. The gripping unit includes an upper member and a lower member that grip the jacket by clamping it. When removing the jacket, the gripping unit moves away from the retaining member, while the upper and lower members simultaneously move in opposite directions in the left-right direction. This allows the jacket to be removed while rotating.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Utility Model Application Laid-Open No. 3-120622 Summary of the Invention

[0007] (1) Technical issues to be resolved

[0008] The total rotation amount of the sheath can be preset based on the twist pitch of the wires twisted within the sheath. If the sheath stripping length is set to L [mm] and the total rotation amount of the sheath is set to α [degrees], the sheath rotates α [degrees] when it moves a distance L [mm] in the axial direction of the multi-core cable. When the sheath is removed at a constant speed and rotated at a constant rotational speed, the sheath rotation amount per unit distance traveled is α / L [degrees / mm].

[0009] Furthermore, the inventors' test results revealed that when the sheath is pulled out at a constant speed and rotated at a constant rotational speed, the twist of the wire may not be fully corrected if the sheath to be pulled out is long.

[0010] The present invention is made to solve the above-mentioned problems, and its purpose is to simultaneously remove the sheath and correct the twisted shape of the wires in a detwisting device for a multi-core cable, so as to correct the twisted shape better than the prior art.

[0011] (2) Technical solution

[0012] The present invention relates to a multi-core cable detwisting device that removes the front end portion of a sheath of a multi-core cable having a plurality of wires and a sheath covering the wires, and corrects the twisting of the wires. The detwisting device comprises: a retaining member that retains a non-front end portion of a sheath having a notch formed between the front end portion and the non-front end portion; a gripping member that grips the front end portion of the sheath; a pulling device that removes the front end portion of the sheath by moving at least one of the gripping member and the holding member so that the gripping member moves away from the holding member; a rotating device that rotates the front end portion and the non-front end portion of the sheath gripped by the gripping member relative to each other; and a control device that controls the pulling device and the rotating device. The control device is configured to execute a first control and a second control. The first control controls the extraction device and the rotation device so that the amount of rotation per unit distance of movement of the sheath tip portion is less than a predetermined amount of rotation during the period from the start to the end of extraction of the sheath tip portion. The second control controls the extraction device and the rotation device so that the amount of rotation per unit distance of movement of the sheath tip portion is greater than or equal to the predetermined amount of rotation. Furthermore, "less than the predetermined amount of rotation" includes a case where the amount of rotation is zero (in other words, no rotation).

[0013] When removing the sheath of a multi-core cable, the wires are stretched due to friction from the sheath. However, because the wires within the sheath are twisted, they become tightly attached when stretched. While the wires are tightly attached, even if the sheath is rotated in the opposite direction of the wire twist, the twist cannot be fully corrected if the amount of rotation per unit distance is small.

[0014] Furthermore, according to the above-mentioned detwisting device, the first control and the second control are executed from the start to the end of the extraction of the front end portion of the sheath. In the second control, the rotation amount of the front end portion of the sheath per unit distance of movement is larger. For example, when the stripping length of the sheath is set to L [mm] and the total rotation amount of the sheath is set to α [degrees], the rotation amount of the sheath per unit distance of movement in the second control is greater than α / L [degrees / mm]. Therefore, according to the above-mentioned detwisting device, the twisted shape can be corrected better than the conventional technology. On the other hand, in the first control, the rotation amount of the front end portion of the sheath per unit distance of movement is small or zero. Therefore, from the start to the end of the extraction, the total rotation amount of the front end portion of the sheath will not be too large. Therefore, excessive rotation of the front end portion of the sheath can be avoided, and the wire will not develop a new twisted shape in the opposite direction.

[0015] According to a preferred embodiment, the control device is configured to remove the distal end portion of the sheath without rotating it in the first control, and to remove the distal end portion of the sheath while rotating it in the second control.

[0016] According to the above aspect, since the front end of the sheath is not rotated in the first control, the rotation amount per unit movement distance of the front end of the sheath can be increased accordingly in the second control. Therefore, excessive rotation of the front end of the sheath can be avoided and the twisted state can be corrected well.

[0017] According to a preferred embodiment, the control device is configured to execute the second control after the first control.

[0018] According to the above aspect, the front end portion of the sheath can be pulled out satisfactorily, and the twisted shape of the electric wire can be corrected satisfactorily.

[0019] According to a preferred embodiment, the control device is configured to repeat the first control and the second control two or more times during a period from the start to the end of extraction of the distal end portion of the sheath.

[0020] The detwisting device described above can effectively correct the twist of the wire when executing the second control. In this case, the closer the wire portion is to the sheath portion held by the gripping device, the more effectively the twist is corrected. According to the above embodiment, the first and second controls can be repeated two or more times. Therefore, effective twist correction can be reliably performed. Consequently, the twist can be corrected more effectively.

[0021] According to a preferred embodiment, the pulling-out lengths of each time in the first control are equal to each other, and / or the pulling-out lengths of each time in the second control are equal to each other.

[0022] According to the above aspect, the first control and / or the second control becomes simple.

[0023] According to a preferred embodiment, the total withdrawal length of the tip end portion of the sheath during the nth (n is a predetermined natural number) first and second controls is shorter than the total withdrawal length of the tip end portion of the sheath during the mth (m is a predetermined natural number other than n) first and second controls. The rotation amount of the tip end portion of the sheath during the nth second control is smaller than the rotation amount of the tip end portion of the sheath during the mth second control.

[0024] According to the above aspect, the rotation amount per unit movement distance of the tip portion of the sheath can be made relatively uniform during the nth and mth first and second controls. Therefore, the twisting of the wire can be relatively uniformly corrected during the nth and mth first and second controls.

[0025] According to a preferred embodiment, when the total pulling-out length of the front end portion of the sheath in the n-th (n is a predetermined natural number) first control and second control is set to L n , and the rotation amount of the front end portion of the sheath in the nth second control is set to α n The total pulling-out length of the front end portion of the sheath in the n+1th first control and the second control is set to L n+1 , and the rotation amount of the front end portion of the sheath in the second control of the n+1th time is set to α n+1 When α n / L n =α n+1 / L n+1 .

[0026] According to the above aspect, the amount of rotation per unit distance of movement of the tip of the sheath is equal during the nth and n+1th first and second controls. Therefore, the twisting of the wire can be uniformly corrected during the nth and n+1th first and second controls.

[0027] According to a preferred embodiment, the rotating device includes an actuator for rotating the gripping member.

[0028] According to the above aspect, since the distal end portion of the sheath can be stably rotated, at least the second control can be stably executed. In addition, the gripping member can be miniaturized regardless of the rotation amount of the distal end portion of the sheath.

[0029] According to a preferred embodiment, the control device is configured to pull out the distal end portion of the sheath by 60 mm or more during a period from the start to the end of pulling out the distal end portion of the sheath.

[0030] Generally, the longer the extension length of the front end portion of the sheath is, the more difficult it is to correct the twisted shape of the wire. According to the above embodiment, the following effect can be significantly exerted, that is, the twisted shape can be corrected well compared with the conventional technology.

[0031] (3) Beneficial effects

[0032] According to the present invention, in the untwisting device for a multi-core cable, the sheath is pulled out and the twisted shape of the wires is corrected simultaneously, which can correct the twisted shape better than the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a perspective view of a twist relief device for a multi-core cable according to one embodiment.

[0034] Figure 2 It is a side view of the back-twist device.

[0035] Figure 3 (a) is a top view of a multi-core cable. Figure 3 (b) is a plan view of the multi-core cable showing the interior of the front end portion.

[0036] Figure 4 is a side view of the holding fixture.

[0037] Figure 5 It is a cross-sectional view of the holding fixture.

[0038] Figure 6 This is the main view of the holding fixture.

[0039] Figure 7 This is a block diagram of the control device and actuators.

[0040] Figure 8 This is a functional block diagram of the control device.

[0041] Figure 9 This is a diagram showing the relationship between the extraction sections of the sheath distal end portion and the control performed in these sections, according to one embodiment.

[0042] Figure 10 (a) is a photograph showing an example of a multi-core cable in which the front end portion of the sheath is pulled out using the method of the embodiment. Figure 10 (b) is a photograph showing an example of a multi-core cable in which the front end portion of the sheath is pulled out using a conventional method.

[0043] Figure 11 This is a diagram showing the relationship between the extraction sections of the sheath distal end portion and the control performed in these sections, in accordance with another embodiment.

[0044] Figure 12This is a diagram showing the relationship between the extraction sections of the sheath distal end portion and the control performed in these sections, in accordance with another embodiment. DETAILED DESCRIPTION

[0045] A backtwist device for a multi-core cable (hereinafter referred to as a backtwist device) according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Figure 1 is a perspective view of the back-twist device 1, Figure 2 3 is a side view of the backtwist device 1 . Figure 3 (a) is a top view of the multi-core cable 3, Figure 3 (b) is a plan view showing the interior of the front end portion of the multi-core cable 3 .

[0046] like Figure 3 (a) and Figure 3 As shown in (b), the multi-core cable 3 has: a plurality of coated electric wires 4, an uncoated electric wire 6, and a sheath 5 covering these electric wires 4 and 6. The electric wire 6 has a plurality of wires made of a conductor such as metal, which is omitted in the figure. The electric wire 4 has: a plurality of wires made of a conductor such as metal, and a sheath made of an insulator such as synthetic resin covering these wires. Hereinafter, the coated electric wires 4 and the uncoated electric wires 6 will be referred to as core wires and drain wires, respectively. Here, the multi-core cable 3 has four core wires 4. However, the number of core wires 4 is not particularly limited. In addition, the number of drain wires 6 is not particularly limited. The material of the sheath 5 is not particularly limited, and may be, for example, chloroprene rubber, polyvinyl chloride resin, polyethylene, etc.

[0047] like Figure 3 As shown in (a), a cut (also called a slit) 5C is pre-formed on the sheath 5 of the multi-core cable 3 processed by the back-twist device 1. The sheath 5 is divided into a front end portion (hereinafter referred to as the sheath front end portion) 5A and a non-front end portion 5B by the cut 5C. Figure 3 As shown in (b), a core wire 4 and a drain wire 6 are twisted in the sheath 5. That is, the core wire 4 and the drain wire 6 in the sheath 5 extend in a spiral shape and have a twisted shape. The detwisting device 1 is used to pull out the front end portion 5A of the sheath and correct the twisted shape of the exposed core wire 4 and the drain wire 6.

[0048] like Figure 1 As shown, the back-twist device 1 includes: a holding device 10 that holds the non-front end portion 5B of the sheath 5 of the multi-core cable 3; a gripping device 20 that grips the front end portion 5A of the sheath; a pulling device 30 that pulls out the front end portion 5A of the sheath; and a rotating device 40 that rotates the front end portion 5A of the sheath. Figure 2 As shown, the back-twist device 1 includes a control device 50 for controlling the holding device 10, the gripping device 20, the extraction device 30, and the rotation device 40. In the following description, for convenience, the front end portion 5A side of the sheath 5 ( Figure 2 The right side of the front end is called the front side, and the non-front end 5B side ( Figure 2 The left side of the sheath is called the rear side. The front end portion 5A of the sheath is the portion pulled out forward.

[0049] like Figure 1 As shown, the holding device 10 includes a holding fixture 11 having a pair of left and right clamping claws 11L and 11R, and an actuator 12 that drives the clamping claws 11L and 11R to move toward or away from each other. Actuator 12 is not particularly limited, but is comprised of an air cylinder. When the clamping claws 11L and 11R are moved toward each other, the holding fixture 11 closes. This holds the non-tip portion 5B of the sheath 5, sandwiched between the clamping claws 11L and 11R. When the clamping claws 11L and 11R are moved away from each other, the holding fixture 11 opens. This releases the non-tip portion 5B of the sheath 5 from being held.

[0050] The gripping device 20 includes a gripping jig 26 and an actuator 25 that opens and closes the gripping jig 26 .

[0051] Figure 4 is a side view of the holding fixture 26, Figure 5 It is a cross-sectional view of the holding jig 26 . Figure 6 2 is a front view of the holding fixture 26. The holding fixture 26 includes a first clamping claw 21 and a second clamping claw 22. The first clamping claw 21 and the second clamping claw 22 are opposed to each other so as to be able to hold the sheath front end portion 5A. Here, the first clamping claw 21 includes a plurality of triangular plate members 21a arranged in the front-to-back direction (see FIG. Figure 5 and Figure 6 ). Furthermore, the second clamping jaw 22 includes a plurality of triangular plate members 22a arranged in the front-to-back direction. The plate members 21a and 22a are arranged in a staggered manner in the front-to-back direction. The structures of the first and second clamping jaws 21 and 22 described herein are merely illustrative. The structures of the first and second clamping jaws 21 and 22 are not particularly limited as long as they can grip the sheath distal end portion 5A.

[0052] When the first clamping claw 21 and the second clamping claw 22 approach each other, the sheath tip 5A is clamped by the first clamping claw 21 and the second clamping claw 22. Thus, the sheath tip 5A is held by the first clamping claw 21 and the second clamping claw 22. When the first clamping claw 21 and the second clamping claw 22 move away from each other, the sheath tip 5A is released from grip.

[0053] like Figure 5 As shown in FIG, the holding fixture 26 includes: a link mechanism 23 connected to the first clamping claw 21 and the second clamping claw 22; and a piston rod 24 connected to the link mechanism 23. Figure 2As shown, the piston rod 24 is connected to the actuator 25. The actuator 25 is not particularly limited, and is composed of a cylinder. The piston rod 24 is connected in a manner that allows it to rotate relative to the actuator 25. Figure 2 As shown, when the actuator 25 moves the piston rod 24 forward ( Figure 2 When the piston rod 24 moves to the right, the first clamping claw 21 and the second clamping claw 22 separate from each other. That is, when the piston rod 24 extends forward, the holding clamp 26 opens and the holding of the holding clamp 26 is released. On the other hand, Figure 4 and Figure 5 As shown, when the actuator 25 moves the piston rod 24 backward, the first clamping claw 21 and the second clamping claw 22 approach each other. That is, when the piston rod 24 contracts, the holding clamp 26 closes and the holding clamp 26 holds the front end portion 5A of the sheath. In addition, Figure 4 The solid line represents the state in which the holding clamp 26 is closed, and the double-dashed line represents the state in which the holding clamp 26 is opened. In this way, the holding clamp 26 is opened and closed by the actuator 25. Figure 1 The piston rod 24 is omitted in the figure.

[0054] like Figure 1 As shown, the rotating device 40 includes: a support plate 43 that supports the holding clamp 26 in a rotatable manner; and a motor 41 that applies a rotational force to the holding clamp 26. The motor 41 is supported by the support plate 43. The rotating shaft 41a of the motor 41 is connected to the holding clamp 26 by a belt 42. The belt 42 is a transmission component that transmits the power of the motor 41 to the holding clamp 26. However, the transmission component is not limited to the belt 42, and can also be a transmission component in other forms such as a gear or a chain. In addition, the motor 41 is an example of an actuator that applies a rotational force to the holding clamp 26, but the actuator that applies a rotational force to the holding clamp 26 is not limited to the motor 41. In this embodiment, the rotating device 40 is configured to rotate the front end portion 5A of the sheath by rotating the holding clamp 26.

[0055] The extraction device 30 is configured to extract the front end portion 5A of the sheath by moving the holding fixture 26 away from the retaining fixture 11 along the length direction of the multi-core cable 3. The extraction device 30 includes: a movable table 31, which supports the holding device 20 and the rotating device 40; a motor 32, which moves the movable table 31 forward and backward; and a fixed table 35, which supports the movable table 31 and the motor 32. A guide rail 36 extending forward and backward is provided above the fixed table 35. A slider 37 is fixed to the lower right part of the movable table 31, which is slidably engaged with the guide rail 36. A ball screw 33 is connected to the motor 32. As shown in FIG. Figure 2As shown, a slider 34 engaged with the ball screw 33 is fixed to the lower left part of the movable table 31. A hole (not shown) for inserting the ball screw 33 is formed on the slider 34. A spiral groove engaged with the ball screw 33 is formed on the inner circumference of the hole. When the motor 32 rotates in one direction, the ball screw 33 rotates in the same direction, and the slider 34 moves forward. As a result, the holding fixture 26 moves forward. When the motor 32 rotates in the opposite direction, the ball screw 33 also rotates in the opposite direction, and the slider 34 moves backward. As a result, the holding fixture 26 moves backward. In this way, since the motor 32 rotates in one direction or the opposite direction, the holding fixture 26 moves forward or backward.

[0056] The control device 50 controls the holding device 10, the gripping device 20, the extracting device 30, and the rotating device 40. Figure 7 As shown, the control device 50 is composed of a computer having a CPU 50A, a ROM 50B, a RAM 50C, and the like. The control device 50 is communicatively connected to the actuator 12 of the holding device 10, the actuator 25 of the gripping device 20, the motor 32 of the extraction device 30, and the motor 41 of the rotation device 40. The control device 50 may be a dedicated computer for the backtightening device 1 or a general-purpose computer such as a personal computer.

[0057] Figure 8 1 is a functional block diagram of the control device 50. The control device 50 functions as the following extraction control unit 51 and rotation extraction control unit 52 by executing a computer program stored in the ROM 50B or an external storage device.

[0058] The extraction control unit 51 performs control (hereinafter referred to as first control) to extract the sheath distal end portion 5A without rotating it. Specifically, the extraction control unit 51 stops the motor 41 of the rotation device 40 and drives the motor 32 of the extraction device 30. As a result, the gripping jig 26 holding the sheath distal end portion 5A moves forward without rotating.

[0059] The rotation and extraction control unit 52 performs control of rotating and extracting the front end portion 5A of the sheath (hereinafter referred to as the second control). In detail, the rotation and extraction control unit 52 drives the motor 41 of the rotating device 40 and drives the motor 32 of the extraction device 30. As a result, the holding clamp 26 holding the front end portion 5A of the sheath rotates and moves forward. The second control is executed following the first control. In this embodiment, the first control and the second control are repeated multiple times during the period from the beginning to the end of the extraction of the front end portion 5A of the sheath. In addition, the twisting direction of the core wire 4 and the drain wire 6 in the sheath 5 (hereinafter referred to as the twisting direction) can be known in advance. In the second control, the front end portion 5A of the sheath is rotated in the opposite direction of the twisting direction of the core wire 4 and the drain wire 6.

[0060] The above describes the structure of the detwisting device 1. Next, the method for removing the sheath tip 5A using the detwisting device 1 will be described. In the following description, the method of removing the sheath tip 5A at a constant speed while rotating the sheath tip 5A at a constant angle from the start to the end of removal is referred to as the "conventional method." The removal method of this embodiment will be described in comparison with this conventional method.

[0061] The length of the sheath tip 5A removed (i.e., the stripping length) is set to L [mm], and the total rotation amount of the sheath tip 5A from the start of removal to the end of removal is set to α [degrees]. In conventional methods, since the sheath tip 5A moves forward at a constant speed while rotating at a constant rotation angle from the start of removal to the end of removal, the rotation amount per unit distance of movement of the sheath tip 5A is α / L [degrees / mm]. For example, when L = 80 [mm] and α = 960 [degrees], the sheath tip 5A is removed while rotating under the condition of α / L = 12 [degrees / mm].

[0062] On the other hand, in this embodiment, Figure 9 As shown, the period from the start to the end of the extraction of the sheath front end 5A is divided into 8 intervals, and the first control and the second control are repeated four times. The reference numerals C1 and C2 in the figure respectively represent the intervals in which the first control and the second control are executed. In the first control, the sheath front end 5A is not rotated but extracted at a constant speed for 10 mm. In the second control, the sheath front end 5A is extracted at a constant speed while being rotated at a constant speed, as in the conventional method. However, in this embodiment, a total rotation amount α = 960 [degrees] is performed by performing the second control a total of four times, so the average rotation amount per second control is 960 / 4 = 240 [degrees]. The rotation amount α / L per unit moving distance in the second control is 240 / 10 = 24 [degrees / mm], which is twice that of the conventional method.

[0063] exist Figure 10 (a) shows three examples of multi-core cables in which the sheath front end portion 5A is pulled out by the method of this embodiment. Figure 10 (b) shows three examples of multi-core cables in which the sheath front end portion 5A is pulled out by a conventional method. Figure 10 (a) and Figure 10 As can be seen from (b), according to this embodiment, the twisting shape of the core wire 4 and the noise-draining wire 6 can be corrected better than the prior art.

[0064] In the multi-core cable 3, friction is generated between the front end 5A of the sheath and the core wire 4, and between the front end 5A of the sheath and the drain wire 6. When the front end 5A of the sheath is rotated, the friction is used to transmit rotational force to the core wire 4 and the drain wire 6, thereby correcting the twisted shape. However, since the front end 5A of the sheath is stretched forward, the core wire 4 and the drain wire 6 are also stretched forward due to the friction. Here, since the core wire 4 and the drain wire 6 are twisted, they fit tightly together if stretched. If the core wire 4 and the drain wire 6 fit tightly together, it is presumed that the twisted shape of the core wire 4 and the drain wire 6 cannot be fully corrected unless the front end 5A of the sheath is rotated significantly. With the existing method, since the rotation amount of the front end 5A of the sheath per unit moving distance is small, it is presumed that the twisted shape of the core wire 4 and the drain wire 6 cannot be fully corrected.

[0065] In contrast, in the present embodiment, the first control and the second control are performed, and in the second control, the rotation amount of the sheath front end portion 5A per unit moving distance is larger. The rotational force per unit moving distance in the second control is twice that of the existing method. Therefore, it is presumed that the twisted form of the core wire 4 and the drain wire 6 can be fully corrected. In addition, although it is also possible to rotate the sheath front end portion 5A without pulling it out, depending on the operating conditions of the device, there is a situation where the core wire 4 and the drain wire 6 expand radially outward from the center of rotation and are buckled. However, in the second control, the sheath front end portion 5A is pulled out while being rotated. Therefore, the buckling of the core wire 4 and the drain wire 6 can be prevented.

[0066] In addition, for the existing method, it is possible to consider increasing the amount of rotation per unit moving distance. For example, for the existing method, it is possible to consider setting it to α / L = 24 [degrees / mm]. However, in this case, the total amount of rotation of the front end portion 5A of the sheath is 24 [degrees / mm] × 80 [mm] = 1920 degrees. The total amount of rotation is 2 times. However, if the total amount of rotation is too large, the core wire 4 and the drain wire 6 are excessively untwisted in the opposite direction of the twisting direction, and the quality of the core wire 4 and the drain wire 6 may be reduced. In addition, it is possible to bring a new twisting form in the opposite direction to the core wire 4 and the drain wire 6. On the other hand, according to the present embodiment, the front end portion 5A of the sheath is not rotated in the first control. Therefore, even if the amount of rotation per unit moving distance in the second control is large, the total amount of rotation of the front end portion 5A of the sheath will not be too large.

[0067] According to the present embodiment, the front end portion 5A of the sheath can be pulled out well, and the twisted form of the core wire 4 and the drain wire 6 can be corrected well without damaging their quality. According to the present embodiment, similar to the existing method, since the front end portion 5A of the sheath can be pulled out and the core wire 4 and the drain wire 6 can be corrected at the same time, the processing cycle of the multi-core cable 3 can be shortened. In addition, according to the present embodiment, since the twisted form of the core wire 4 and the drain wire 6 can be corrected better than the existing technology, the subsequent processing of the core wire 4 and the drain wire 6 can be carried out well. It is easy to automate the subsequent processing of the core wire 4 and the drain wire 6.

[0068] However, when the front end portion 5A of the sheath is rotated when it is located near the front ends of the core wire 4 and the drain wire 6, the parts near the front ends of the core wire 4 and the drain wire 6 can be untwisted, but the root parts cannot be untwisted. In particular, when the stripping length is long, such a tendency is greater. However, in this embodiment, the first control and the second control are repeated multiple times. Therefore, the core wire 4 and the drain wire 6 can be reliably untwisted from the beginning to the end of the extraction of the front end portion 5A of the sheath. In addition, in the second control, the twisted form of the part from which the front end portion 5A of the sheath was extracted in the first control can be centrally corrected. For example, when the second control is performed for the first time, the root parts of the core wire 4 and the drain wire 6 can be fully untwisted. When the second control is performed for the fourth time, the front end parts of the core wire 4 and the drain wire 6 can be fully untwisted. Therefore, even when the stripping length is long, the twisted form of the core wire 4 and the drain wire 6 can be well corrected.

[0069] In this embodiment, the sheath tip 5A is pulled at the same speed during the first and second controls. The sheath tip 5A is pulled out at the same speed during the first and second controls. In other words, the movement speed of the gripping jig 26 during the first and second controls is the same. Consequently, the movement speed of the sheath tip 5A remains constant during the transition from the first to the second control, and vice versa. Consequently, the sheath tip 5A can be pulled out stably.

[0070] In this embodiment, the extraction length in both the first control and the second control is 10 mm. The extraction length in the first control is equal to the extraction length in the second control. This allows the front end portion 5A of the sheath to be extracted well, and the twisted shape of the core wire 4 and the drain wire 6 to be corrected more effectively.

[0071] In this embodiment, the pull-out length in the first control from the first time to the fourth time is 10 mm. In addition, the pull-out length in the second control from the first time to the fourth time is 10 mm. The pull-out lengths of each time in the first control are equal to each other. The pull-out lengths of each time in the second control are equal to each other. As a result, the first control and the second control become simple. In addition, the core wire 4 and the disturbance-discharge wire 6 can be untwisted evenly.

[0072] In the detwisting device 1 of this embodiment, the rotation device 40 is configured to rotate the holding fixture 26. Rotating the holding fixture 26, which holds the sheath tip 5A, rotates the sheath tip 5A. Therefore, the sheath tip 5A can be rotated stably. Therefore, the first and second controls can be stably executed. Furthermore, in a structure that rotates the sheath tip by moving the upper and lower components that sandwich the sheath in opposite directions (see Japanese Utility Model Publication No. 3-120622), the dimensions of the upper and lower components (i.e., the length in the moving direction) must be proportional to the amount of rotation of the sheath tip. Therefore, if the sheath tip rotates significantly, the upper and lower components will become larger. On the other hand, with the rotation device 40 of this embodiment, the holding fixture 26 does not become larger even if the sheath tip 5A rotates significantly. Therefore, the holding fixture 26 can be miniaturized regardless of the amount of rotation of the sheath tip 5A.

[0073] In addition, in the detwisting device 1, the moving distance of the holding clamp 26 when the front end portion 5A of the sheath is pulled out is not particularly limited. In other words, the length of the pulled out front end portion 5A of the sheath (stripping length) is not particularly limited. However, generally, the longer the stripping length, the more difficult it is to correct the twisted form of the core wire 4 and the drain wire 6. Therefore, the longer the stripping length of the multi-core cable 3, the more obvious the effect of the detwisting device 1 of this embodiment, that is, the effect of being able to well correct the twisted form of the core wire 4 and the drain wire 6. For example, when the stripping length is more than 60 mm, the detwisting device 1 of this embodiment is particularly effective. The control device 50 can be configured to pull out more than 60 mm of the sheath front end portion 5A during the period from the start to the end of the pulling out of the sheath front end portion 5A.

[0074] While one embodiment of the present invention has been described above, the above embodiment is merely an example, and various other embodiments are possible. Next, another embodiment will be described.

[0075] In the embodiment described above, the pull-out length in the first control is equal to the pull-out length in the second control, both being 10 mm. However, the pull-out length in the first control and the pull-out length in the second control may be different. For example, Figure 11As shown, when the peeling length is 90 mm, the pull-out length in the first control can be set to 20 mm, and the pull-out length in the second control can be set to 10 mm. In this case, the pull-out length in the second control (= 10 mm) is 1 / 3 of the total pull-out length in the first and second controls (= 30 mm). The amount of rotation in the second control can be appropriately set. For example, the amount of rotation α / L per unit moving distance in the second control can be 3 times the amount of rotation α / L per unit moving distance in the existing method. In addition, the pull-out length in the first control can be longer or shorter than the pull-out length in the second control.

[0076] In the embodiment (refer to Figure 9 ), the pulling lengths of each first control are equal to each other, and the pulling lengths of each second control are equal to each other. For example, the pulling length of the first first control is 10mm, and the pulling length of the second first control is 10mm. However, the pulling lengths may be different for multiple first controls. In addition, the pulling lengths may be different for multiple second controls. For example, Figure 12 As shown, the first controlled pulling-out length for the first time may be 50 mm, and the second controlled pulling-out length for the second time may be 20 mm.

[0077] When the first control and the second control are performed multiple times, the rotation amount α / L per unit moving distance can be made constant. In this way, the twisting form of the core wire 4 and the disturbance wire 6 can be uniformly corrected. When n is set to a specified natural number, the total pulling length in the first control and the second control of the nth time is set to L n , set the rotation amount in the second control of the nth time to α n , set the total extraction length in the first control and the second control of the n+1th time to L n+1 , set the rotation amount in the second control of the n+1th time to α n+1 When , it can be set to α n / L n =α n+1 / L n+1 In e.g. Figure 12 In the example shown, since L1 = 60 mm and L2 = 30 mm, it can be set to α1 / 60 = α2 / 30. In this case, α2 = 0.5 × α1.

[0078] In the above example, L2 is shorter than L1, and α2 is smaller than α1. In this way, when performing the first control and the second control multiple times, the shorter the total pull-out length of each time, the smaller the rotation amount can be. When the total pull-out length in the nth first control and the second control is shorter than the total pull-out length in the mth first control and the second control (however, m is a specified natural number other than n), the rotation amount in the nth second control can be smaller than the rotation amount in the mth second control. In this way, the twisted shape of the core wire 4 and the interference-discharge wire 6 can be corrected more evenly.

[0079] In the first control and the second control, the extraction speeds may be equal or different. Furthermore, the extraction speeds in each of the first control steps may be different from one another. The extraction speeds in each of the second control steps may be different from one another. For example, the further back the extraction step is, the faster or slower the extraction speed may be.

[0080] For example, in the case of a multi-core cable 3 with a short stripping length, the twisted form of the core wire 4 and the drain wire 6 can be well corrected even if the first control and the second control are performed only once.

[0081] In the above embodiment, the first control is performed immediately after the sheath distal end portion 5A is started to be pulled out. However, the second control may be performed immediately after the sheath distal end portion 5A is started to be pulled out.

[0082] In the embodiment, the sheath front end portion 5A is not rotated in the first control, and the sheath front end portion 5A can be pulled out while being rotated in the first control. When the total rotation amount of the sheath front end portion 5A is constant, the rotation amount α / L per unit moving distance in the first control is made smaller than that in the prior art, so that the rotation amount α / L per unit moving distance in the second control can be made larger than that in the prior art. For example, in the first control, the sheath front end portion 5A is pulled out while being rotated at a first rotational speed, and in the second control, the sheath front end portion 5A is pulled out while being rotated at a second rotational speed that is greater than the first rotational speed. Even with such control, α / L can be made larger in the second control than in the prior art method. Therefore, the twisted shape of the core wire 4 and the drain wire 6 can be corrected better than in the prior art method.

[0083] During the period from the beginning to the end of the extraction of the front end portion 5A of the sheath, only the first control and the second control may be performed, or other controls may be performed in addition to the first control and the second control. For example, after the front end portion 5A of the sheath is first extracted, a control may be performed in which the front end portion 5A of the sheath is extracted while being rotated in the same direction as the twisting direction of the core wire 4 and the drain wire 6, and then the first control and the second control may be performed. In addition, in the second control, the front end portion 5A of the sheath is extracted while being rotated, and the rotation direction at this time is the opposite direction to the twisting direction of the core wire 4 and the drain wire 6.

[0084] The method for rotating the sheath tip 5A is not particularly limited. The structure for rotating the sheath tip 5A is not particularly limited. For example, the gripping jig 26 may include a pair of upper and lower clamp members, which move in opposite directions in the left-right direction while clamping the sheath tip 5A. In this case, the sheath tip 5A rotates by rolling on the pair of upper and lower clamp members.

[0085] In the above embodiment, the sheath tip 5A is rotated while the non-tip portion 5B of the sheath 5 is stationary. However, the structure and operation of the rotating device are not particularly limited as long as the sheath tip 5A can be rotated relative to the non-tip portion 5B. Alternatively, the non-tip portion 5B of the sheath 5 can be rotated without rotating the sheath tip 5A. Alternatively, the sheath tip 5A and the non-tip portion 5B can be rotated in opposite directions.

[0086] The structure of the gripping jig 26 is not particularly limited. The gripping jig 26 may have any structure capable of gripping the sheath distal end 5A. For example, the gripping jig 26 may include a pair of plate-shaped members that grip the sheath distal end 5A instead of the first and second gripping jaws 21 and 22 .

[0087] In the embodiment, the multi-core cable 3 has four core wires 4 and one drain wire 6. However, the number of core wires 4 and the number of drain wires 6 are not particularly limited. In addition, the drain wire 6 is not necessarily required. The multi-core cable 3 may have a plurality of coated wires and no uncoated wires. In addition, the multi-core cable 3 may have a plurality of uncoated wires and no coated wires.

[0088] In the above embodiment, the extraction device 30 extracts the sheath distal end portion 5A by moving the gripping jig 26. However, the extraction device 30 may also extract the sheath distal end portion 5A by moving the holding jig 11 away from the gripping jig 26. Furthermore, the extraction device 30 may also extract the sheath distal end portion 5A by moving both the gripping jig 26 and the holding jig 11 away from the holding jig 11.

[0089] The structure of the detwisting device 1 in the above embodiment is merely an example. As the detwisting device, any device capable of executing the above-mentioned first control and second control can be adopted.

[0090] Description of Reference Numerals

[0091] 1- Untwisting device for multi-core cable; 3- Multi-core cable; 4- Covered electric wire (core wire); 5- Sheath; 5A- Front end portion of the sheath; 5B- Non-front end portion of the sheath; 6- Uncovered electric wire (drain wire); 10- Holding device; 11- Holding clamp (Holding component); 12- Actuator; 20- Holding device; 25- Actuator; 26- Holding clamp (Holding component); 30- Pulling device; 32- Motor; 40- Rotating device; 41- Motor (actuator); 50- Control device.

Claims

1. A multi-core cable untwisting device, which pulls out the front end of a sheath of a multi-core cable having a plurality of electric wires and a sheath covering the electric wires, and corrects the twisting of the electric wires, and comprises: a holding member that holds a non-front end portion of the sheath having a cutout formed therebetween; a holding member for holding the front end portion of the sheath; a pulling device for pulling out the front end portion of the sheath by moving at least one of the holding member and the holding member so that the holding member is separated from the holding member; a rotating device for relatively rotating the front end portion and the non-front end portion of the sheath held by the holding member; as well as a control device for controlling the extraction device and the rotation device, The control device is configured to execute a first control and a second control, wherein the first control controls the extraction device and the rotation device so that the rotation amount per unit movement distance of the front end portion of the sheath is smaller than a predetermined rotation amount during the period from the start to the end of extraction of the front end portion of the sheath; Regarding the second control, the extraction device and the rotation device are controlled so that the rotation amount per unit movement distance of the distal end portion of the sheath is equal to or greater than the predetermined rotation amount.

2. The back-twisting device for a multi-core cable according to claim 1, characterized in that: The control device is configured to pull out the distal end portion of the sheath without rotating it in the first control, and to pull out the distal end portion of the sheath while rotating it in the second control.

3. The back-twisting device for a multi-core cable according to claim 1 or 2, characterized in that: The control device is configured to execute the second control after the first control.

4. The back-twisting device for a multi-core cable according to claim 1 or 2, characterized in that: The control device is configured to repeat the first control and the second control two or more times during a period from the start to the end of extraction of the distal end portion of the sheath.

5. The back-twisting device for a multi-core cable according to claim 4, characterized in that: The pulling-out lengths of each time in the first control are equal to each other, and / or the pulling-out lengths of each time in the second control are equal to each other.

6. The back-twisting device for a multi-core cable according to claim 4, characterized in that: The total pulled-out length of the front end portion of the sheath in the nth first control and the second control is shorter than the total pulled-out length of the front end portion of the sheath in the mth first control and the second control, where n is a predetermined natural number and m is a predetermined natural number other than n. The rotation amount of the front end portion of the sheath in the n-th second control is smaller than the rotation amount of the front end portion of the sheath in the m-th second control.

7. The back-twisting device for a multi-core cable according to claim 4, characterized in that: When the total pulling-out length of the tip of the sheath in the n-th first control and the second control is set to L n , and the rotation amount of the front end portion of the sheath in the nth second control is set to α n The total pulling-out length of the front end portion of the sheath in the n+1th first control and the second control is set to L n+1 , and the rotation amount of the front end portion of the sheath in the second control of the n+1th time is set to α n+1 When α n / L n =α n+1 / L n+1 , n is a specified natural number.

8. The back-twisting device for a multi-core cable according to claim 1 or 2, characterized in that: The rotating device includes an actuator for rotating the gripping member.

9. The detwisting device for a multi-core cable according to claim 1 or 2, characterized in that: The control device is configured to pull out the distal end portion of the sheath by 60 mm or more during a period from the start to the end of pulling out the distal end portion of the sheath.

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