JP2016081672A - Multicore cable and method for producing the multicore cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the fixation stability of a strain relief protecting the edge part of a multicore electric wire with a simple structure.SOLUTION: Provided is a multicore cable 10 obtained by covering a plurality of electric wires with an outer film, having a thick part 41 in which the coating thickness of the outer film 4 at both the edge parts in the longitudinal direction is thicker than the coating thickness of the other part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a multi-core cable and a method for manufacturing a multi-core cable, and more specifically, a multi-core cable having a protective portion for protecting the connector and the multi-core electric wire at a connection portion thereof, and a method for manufacturing the multi-core cable. About.

For cable harness applications such as medical equipment and communication devices, multi-core cables with an electrical connector having a plurality of core wires with a reduced diameter are used.
In such a terminal structure of a cable with an electrical connector, a connector is attached to the end portion of the multi-core cable, and a strain relief is fitted on the attachment portion. This strain relief protects the multicore cable and prevents the core wire from being pulled out or excessively bent.

  For example, Patent Document 1 discloses a cable including a multi-core electric wire and having a configuration in which an end is covered with a rubber boot. The rubber boot has the same function as the above strain relief that protects the end of the multicore cable. However, in Patent Document 1, it is created as a separate part from the multicore electric wire and attached to the multicore electric wire. It is configured to be.

JP 2011-210474 A

  As in Patent Document 1, a strain relief is usually created as a separate part from a multi-core electric wire, and the multi-core cable with a connector can be fixed by attaching the strain relief to the multi-core electric wire. Is created. However, the strain relief prepared as a separate part has a problem in that the strain relief is not fixed and the adhesiveness is not stable due to variations in dimensions or the resin material being different from the resin material of the outer sheath of the electric wire.

  The present invention has been made in view of the above circumstances, and provides a multi-core cable and a method for manufacturing a multi-core cable that realizes the fixing stability of the strain relief protecting the end of the multi-core electric wire with a simple structure. The purpose is to do.

  The multi-core cable according to the present invention is a multi-core cable in which a plurality of electric wires are covered with an outer sheath, and the covering thickness of the outer sheath at both longitudinal ends of the multi-core cable is equal to the covering thickness of other portions. It is a multi-core cable that is thicker than that.

  A manufacturing method of a multi-core cable according to the present invention is a manufacturing method of a multi-core cable in which a plurality of electric wires are covered with an outer sheath, and the wire including at least the plurality of electric wires is taken around in the longitudinal direction while surrounding the wire. The step of coating the resin material to be the outer cover, and the step of covering the resin material to be the outer cover is performed by changing either or both of the take-up speed of the wire and the discharge amount of the resin material, The step of changing the coating thickness of the resin material to be the jacket and connecting the connector with the relatively thick portions at both ends of the multi-core cable after the step of coating the resin material A method for producing a multi-core cable.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the multicore cable which implement | achieves the fixed stability of the strain relief which protects the edge part of a multicore electric wire with a simple structure, and a multicore cable can be provided.

It is a figure which shows an example of the cross-sectional structure of a multi-core cable in this invention. It is an external view which shows the structural example of the multicore cable of this invention. It is a figure which shows typically the extrusion molding machine for coat-molding the jacket which comprises a multicore cable.

First, embodiments of the present invention will be listed and described.
(1) The invention related to the multi-core cable of the present application is a multi-core cable in which a plurality of electric wires are covered with a jacket, and the coating thickness of the jacket at both ends in the length direction of the multi-core cable is other This is a multi-core cable that is thicker than the coating thickness of the part. Thereby, the fixation stability of the strain relief that protects the end portion of the multicore electric wire can be realized with a simple structure.

  (2) In the outer jacket, the inner diameter of the coating layer covering the plurality of electric wires is uniform, and the outer diameter of the outer jacket of the thick portion is not another thick wall. It is preferable that it is larger than the outer diameter of the jacket of the part. Thereby, the thick part of an edge part can be formed, without changing the magnitude | size of the space which accommodates a some electric wire.

  (3) At both ends of the multi-core cable, the end portion of the multi-core cable in which the jacket is thick has a portion where the coating thickness increases toward the end in the length direction. It is preferable. As a result, the thickness of the outer cover of the strain relief portion becomes thicker as it approaches the edge, so that the force due to bending can be absorbed and diffused, and when the cable end is bent, the inner wire (core To prevent the wire from being bent excessively.

  (4) It is preferable that a portion having a uniform coating thickness in the length direction is further provided on the end edge side of the portion where the coating thickness increases toward the edge in the length direction. More specifically, the shape from the middle part having a relatively small coating thickness to the end of the thick part of the cable end part is given.

  (5) The invention related to the method for manufacturing a multicore cable of the present application is a method for manufacturing a multicore cable in which a plurality of electric wires are covered with an outer sheath, while taking a wire including at least the plurality of electric wires in the longitudinal direction. And a step of coating a resin material as a jacket around the wire, and the step of coating the resin material as a jacket includes either a take-up speed of the wire or a discharge amount of the resin material or After changing the coating thickness of the resin material as the jacket by changing both, the connector having the relatively thick coating portions as both ends of the multi-core cable after the step of coating the resin material It is the manufacturing method of a multi-core cable which has the process of connecting. Thereby, the fixed stability of the strain relief that protects the end portion of the multi-core electric wire can be realized with a simple structure.

[Details of the embodiment of the present invention]
Specific examples of the multicore cable and the method of manufacturing the multicore cable according to the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, All the changes within the meaning and range equivalent to a claim are included.

  FIG. 1 is a diagram showing an example of a cross-sectional configuration of a multicore cable according to the present invention. Inside the multi-core cable 10, a plurality of core wires 1 are bundled, and a presser winding 2, a shield layer 3, and a jacket 4 are sequentially formed around the core wire 1. The core wire 1 is, for example, a diameter of about 1 mm or thinner, and a thin coaxial cable in which a central conductor 11, an insulating layer 12, a shield layer 13, and a covering layer 14 are formed in order from the center to the outside, or This is a small-diameter insulated wire whose central conductor is covered with a coating layer.

The presser winding 2 is, for example, a resin tape such as PET (polyethylene terephthalate) or a conductive resin tape that is wound around a plurality of bundled core wires 1 while being vertically attached. The shield layer 3 is formed by, for example, horizontally winding or braiding a plurality of copper strands around the presser winding 2. The jacket 4 is made of, for example, a resin material such as PVC (polyvinyl chloride), polyethylene, polyurethane, silicone, rubber, or an elastomer material.
The end of the multi-core cable 10 is removed, the plurality of core wires 1 are exposed, and a connector (not shown) is connected to the end of the exposed core wire 1.
The above configuration shows an example of a multi-core cable to which the present invention can be applied, and the embodiment according to the present invention can be applied to multi-core cables having various configurations.

  2A and 2B are external views showing a configuration example of the multicore cable of the present invention. FIG. 2A is an external view of the top surface of the multicore cable, and FIG. 2B is an end view of the multicore cable from the axial direction. FIG. A connector 15 is attached to both ends of the multicore cable 10. The outermost layer around the multi-core core wire 1 is covered with a jacket 4. The wire covering the outer jacket 4 includes at least a plurality of electric wires, and for example, the one having the configuration of FIG. 1 is applied. And the thick part 41 for providing the function similar to the conventional strain relief is provided in the both ends of the multi-core cable 10. By providing the thick part 41, the connection part of the edge part of a multicore cable is protected, and it prevents that the core wire 1 is bent too much.

The intermediate part 42 excluding the thick part 41 at both ends of the multicore cable 10 is formed with a substantially identical outer diameter smaller than that of the thick part 41. The thick part 41 and the intermediate part 42 are integrally formed of the same material. Specifically, in the molding step of molding the jacket 4 with a resin material, when the periphery of the wire to be coated including the core wire 1 is covered, the wire take-up speed is changed, or the discharge amount of the resin material By changing the length of the outer periphery of the multi-core cable 10, the thickness of the outer cover 4 is partially increased by intentionally changing the thickness in the length direction around the wire. Cut to form a part and process to connect the connector.
The ratio (T / t) between the maximum value T of the outer diameter of the thick part 41 and the substantially constant outer diameter t of the intermediate part 42 is preferably 1.2 or more and 3 or less. The length of the thick part 41 is preferably 5 mm or more, and more preferably 20 mm or more.
The outer diameter of the intermediate part 42 is preferably 5 to 12 mm. The thickness of the jacket 4 at the intermediate portion 42 is preferably 0.5 to 1.2 mm.

  The jacket 4 has a uniform inner diameter of the coating layer covering the wire material including the plurality of core wires 1, and the outer diameter of the thick portion 41 in which the jacket 4 is thicker is different from that of the other thick wall. It is larger than the outer diameter of the part that is not. By making the inner diameter of the coating layer uniform, the thick portion 41 at the end can be formed without changing the size of the space for accommodating the plurality of core wires 1. Further, the thick portion 41 includes a portion a in which the coating thickness increases toward the edge in the length direction of the multicore cable 10, and a portion b in which the coating thickness is uniform in the length direction on the further edge side of the portion a. have.

  FIG. 3 is a diagram schematically showing an extrusion molding machine for covering and forming an outer sheath constituting a multicore cable. On the unwinding machine 21, a reel around which a wire 30 to be coated for covering the resin material of the outer jacket 4 is wound is laid, and the wire 30 is taken up by the first take-up machine 22 and taken from the reel. It is unwound. The wire rod 30 to be covered with the jacket 4 is a wire rod including at least a plurality of core wires 1, and may be a bundle of a plurality of core wires 1, and as shown in FIG. It is good also as the wire etc. which were bundled up in multiple numbers and wound up in the state which wound the presser winding 2, the shield layer 3, etc. around it.

  The wire 30 taken up by the first take-up machine 22 is introduced into a crosshead die 24 attached to the extruder 23. In the extruder 23, the resin material for forming the outer cover 4 is melted and kneaded and discharged from the crosshead die 24. The discharge amount of the resin material is controlled by the rotational speed of the screw of the extruder 23. Inside the crosshead die 24, the resin material for the jacket 4 melted by the extruder 23 is coated around the wire 30 to be coated.

  The wire covered with the resin material for the jacket 4 is cooled by the cooling device 25, the jacket 4 is cooled and solidified, and the cable 10 'is formed. Thereafter, the molded cable 10 ′ is taken up by the second take-up machine 26 and taken up by the take-up reel 27 by the take-up machine 27. The cable 10 ′ taken up by the take-up reel is cut into a predetermined length, and a process for attaching connectors to both ends is performed to obtain a multicore cable 10.

In order to create the multi-core cable 10, in the present embodiment, either or both of the take-up speed of the wire 30 passing through the crosshead die 24 and the discharge amount of the resin material serving as the jacket 4 are changed, and the outer The coating thickness of the resin material to be covered 4 is intentionally changed.
When changing the take-up speed, the advance speed in the longitudinal direction of the wire rod 30 is changed by changing the take-up speed of the first take-up machine 22 and the second take-up machine 26. If the speed of the wire rod 30 becomes slow when the discharge amount from the extruder 23 is constant, the coating thickness of the resin material that becomes the jacket 4 becomes thick. Here, if the speed of the wire 30 is gradually changed, the coating thickness gradually changes according to the change.

When changing the discharge amount, if the take-up speed of the wire 30 is constant, increasing the discharge amount (discharge amount per unit time) increases the coating thickness of the resin material serving as the outer cover 4. become. If the discharge amount is gradually changed here, the coating thickness gradually changes in accordance with the change.
In the present embodiment, the coating thickness can be controlled by either the change in the take-up speed of the wire 30 or the change in the discharge amount, and the coating can be performed by combining both the change in the speed and the change in the discharge amount. The thickness may be controlled.

The control of the coating thickness of the jacket 4 is executed according to the specifications of the multi-core cable 10 to be created. That is, when the outer casing is extruded by the extrusion molding machine 20, the thick portion 41 in which the covering thickness of the outer casing 4 is thickened is partially provided at the positions to be the both ends of the multicore cable 10. The shape of the thick portion 41 can be made a desired shape by controlling either or both of the speed of the wire 30 and the discharge amount of the resin material of the jacket 4.
The multi-core cable 10 can be obtained by cutting the cable ′ covering the jacket 4 at the portion where the thick portion 41 is formed and attaching connectors to both ends of the cut cable ′.

DESCRIPTION OF SYMBOLS 1 ... Core wire, 2 ... Holding winding, 3 ... Shield layer, 4 ... Outer sheath, 10 ... Multi-core cable, 11 ... Center conductor, 12 ... Insulating layer, 13 ... Shield layer, 14 ... Covering layer, 15 ... Connector, DESCRIPTION OF SYMBOLS 20 ... Extruder, 21 ... Unwinder, 22 ... First take-up machine, 23 ... Extruder, 24 ... Crosshead die, 25 ... Cooling device, 26 ... Second take-up machine, 27 ... Winder, 30 ... Wire rods 41... Thick portion 42.

Claims (5)

  A multi-core cable in which a plurality of wires are covered with a jacket, and the jacket thickness of both ends of the multi-core cable in the longitudinal direction is thicker than the coating thickness of other portions. , Multi-core cable.   The outer cover has a uniform inner diameter of the coating layer covering the plurality of electric wires, and the outer diameter of the outer cover of the thick part is the other part of the outer wall that is not thick. The multi-core cable according to claim 1, wherein the multi-core cable is larger than an outer diameter of the jacket. At both ends of the multicore cable,
The multi-core cable according to claim 2, wherein an end portion of the multi-core cable having a thick outer jacket has a portion whose covering thickness increases toward an end edge in a length direction.   The multi-core cable according to claim 3, further comprising a portion where the coating thickness is uniform in the length direction on the end edge side of the portion where the coating thickness increases toward the end edge in the length direction. A method of manufacturing a multi-core cable in which a plurality of wires are covered with a jacket,
A step of covering the periphery of the wire with a resin material serving as an outer covering, while taking a wire including at least a plurality of electric wires in the longitudinal direction;
The step of coating the resin material to be the outer cover changes the coating thickness of the resin material to be the outer cover by changing either or both of the take-up speed of the wire and the discharge amount of the resin material,
A method of manufacturing a multi-core cable, comprising a step of connecting a connector after the step of coating the resin material, with the portions having a relatively large coating thickness as both ends of the multi-core cable.

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