JP2007109665A - Sheath wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the processing of a terminal or a middle part of a sheath wire. <P>SOLUTION: A sheath 5 is arranged so as to easily slide on a core 2 by reducing an adhesion force between the core 2 of the sheath wire 11 and the sheath 5. For example, in the case of mounting terminals 6 on both terminal parts of the sheath wire 11, if a terminal side at one side of the sheath 5 is removed, the terminals 6 can be mounted on both the terminal parts by making the residual sheath 5 slide on the core 2. Compared with a conventional sheath wire having a large adhesion force between the core and the sheath, the processing range of the sheath is narrowed, and the range of coating a protection material 7 on an exposed part of the core 2 is also reduced, and a man-hour and a quantity of the protection material 7 to be used are saved to attain cost reduction. The work of forming a notch and tearing off the sheath becomes unnecessary, the problem of the breakage of the core is prevented, and reliability is improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention, on the outer periphery of the two cores coated with an insulator conductors relates to a sheath wire having a sheath by extrusion of the resin of the insulator and the like.

6 and 7 show a sheathed electric wire 1 that is used, for example, for automobile wiring. 6 is a plan view of the vicinity of the end portion of the conductor 3 of the sheathed electric wire 1, and FIG. 7 is a cross-sectional view taken along the line AA of FIG. The sheathed electric wire 1 in the illustrated example has a structure in which a sheath 5 is formed by extruding resin on the outer periphery of two cores (insulating cores) 2 in which a conductor 3 is covered with an insulator 4. The sheath 5 is provided mainly for the purpose of mechanical protection.
In this type of conventional sheathed electric wire 1, the sheath 5 covered by extrusion molding is in close contact with the outer periphery of the core 2, and the degree of adhesion is the length of sheath removal required when attaching a terminal to the end of the electric wire. The short length was such that the sheath 5 could be cut out and removed from the core 2.

  The point in the case of attaching a terminal to the both ends of the conventional sheathed electric wire will be described with reference to FIGS. First, the cutter 5 is used to cut the sheath 5 in the vicinity of one end of the sheathed electric wire 1 (position A in FIG. 8A) with a cutter blade (cut in the circumferential direction), and peel off or remove the sheath on the end side. Then, the core 2 is exposed (FIG. 8B), the conductor 3 is then led out (FIG. 8C), and then the terminal 6 is attached to the conductor 3 (FIG. 8D). Next, the other terminal is processed in the same manner as above (FIGS. 8 (e) and (f)), and the terminal 6 is attached to the terminal (FIG. 8 (g)), and then the exposed core 2 is taped or the like. The protective material 7 is covered (FIG. 8 (h)).

Moreover, when attaching a terminal to the intermediate part of the conventional sheathed electric wire, there are the following three methods for exposing the core of the intermediate part.
As shown in FIGS. 9 (A) to 9 (C), the first method is to cut the sheath 5 in the middle part of the sheathed electric wire 1 by the blade of the cutter and separate it into two. To expose the core 2 in the middle of the electric wire.
In the second method, as shown in FIGS. 10 (a) to 10 (c), the sheath 5 is circularly cut at two locations spaced apart by an intermediate portion of the sheathed electric wire 1 with a blade, and the vicinity of the circular cutting position of the sheath 5a between them is cut. Is cut in the direction of the electric wire axis and then torn to the left and right to remove the split sheath piece 5a 'and expose the core 2.
In the third method, as shown in FIGS. 11A to 11C, two sheathed wires 1A and 1B in which the sheath 5 at the end is removed in advance and the conductor 3 is led out are connected to each other by a terminal 7. Is.

In the conventional processing method of the sheathed electric wire 1 shown in FIG. 8, in order to secure a work area for attaching the terminal 6 to the core 2, the sheath 5 in a range larger than the range necessary for attaching the terminal must be peeled off. did not become. Moreover, in order to attach the terminal 6 to both terminals, it was necessary to peel off the sheath 5 by a necessary length at both terminals. For this reason, the part where the core 2 is exposed becomes long, and the range in which the core 2 can be covered with the protective material 7 is considerably wide.
Further, since both ends of the sheath 5 are peeled off, when the length of the sheath wire 1 is short, the sheath 5 covering the core 2 is remarkably shortened, and the protection effect by the sheath 5 is reduced. It was.

The conventional method for processing the intermediate portion of the sheathed electric wire 1 shown in FIGS. 9 to 11 has the following problems.
First, in the first method of FIG. 9, when the sheath 5 is made of a hard material such as polyethylene, it is very difficult to bring the sheath 5 close due to its hardness.
Further, when the insulator 3 and the sheath 5 of the core 2 are made of the same kind of material, it is very difficult to bring the sheath 5 onto the core 2 because the adhesion between the core 2 and the sheath 5 is high. . For this reason, if the sheath 5 is forced to approach, the frictional force generated between the core 5 and the sheath 2 causes the force required to approach the core 2 to exceed the breaking load of the core 2, and the core 2 There was a case where it broke.
In the case of the second method of FIG. 10, when the material of the sheath 5 is a material having high tearability, that is, a material that cannot be easily torn such as rubber, the sheath 5 can be torn. It is necessary to deepen the cut into 5. However, there is a variation in the thickness of the sheath 5, and it is difficult to adjust the depth of cut in consideration of this variation. Therefore, there is a possibility that the core may be damaged when making the cut.
In addition, the third method of FIG. 11 can perform processing regardless of the material of the sheath 5, but the same process as the terminal processing of the sheath wire is performed twice, and is further connected by the terminal 7 and connected to a single wire. The operation of making the sheathed electric wire 1 is complicated because the number of work steps increases. In addition, the number of parts increases.

It is considered that there is no method for directly avoiding the above-mentioned problems in the sheath wire terminal or intermediate sheath removal, and the solution has been mainly sought in the processing technique itself. That is, there has been a demand for improving the method itself for removing the sheath from the core at the end or the middle of the sheath wire (see Japanese Patent Laid-Open Nos. 05-111123 and 10-056716, etc.). However, since such a conventional method becomes a special method and requires a special device, it is desired that the terminal or the intermediate portion can be processed by a usual simple sheath removing operation such as a ring cutting or a slide.
In addition, as a sheathed electric wire in which the sheath can be easily peeled off, a sheath drawing load with a minimum of 5 kgf (4.9 N) with respect to the length of 10 cm of the sheath is described in JP-A-7-65635 (paragraph) No. [0018] Table 1), this sheathed electric wire is a special electric wire in which a silicone oil is blended in an insulator and a release agent is interposed between the insulator and the sheath. In addition, the minimum pulling-out load 5 kgf / 10 cm is 50 kgf / 1 m, which is considerably large, and only a short end portion can be pulled out, and the effect of facilitating the sheath removal work is small.

The present invention has been made in view of the above circumstances, and without having a special structure in which a silicone oil is blended in an insulator or a release agent is used between the insulator and the sheath, the terminal or intermediate of the sheath wire It is an object of the present invention to provide a sheathed electric wire that can be easily processed by a normal simple sheath removing operation such as ring cutting or sliding .

The present invention for solving the above problems is a sheathed electric wire provided with a sheath by extrusion molding of the same kind of resin as the insulator on the outer periphery of two cores whose conductors are covered with an insulator ,
By reducing the adhesion between the core and the sheath, characterized in that the whole of at least one meter or more lengths separated of the sheath, and slidable relative to the core by a force of less than 0.5kgf And
In the sheath electric wire of the present invention, silicone oil is not blended in the insulator, and no release agent is interposed between the insulator and the sheath.

According to a second aspect of the present invention, in the sheathed electric wire according to the first aspect , both the insulator and the sheath are made of a thermoplastic elastomer.

According to a third aspect of the present invention, in the sheathed electric wire according to the first aspect , both the insulator and the sheath are made of a vinyl chloride resin.

According to the sheath electric wire of the present invention, the adhesion force between the core and the sheath is reduced, and the entire length of at least 1 meter or more separated from the sheath is applied to the core with a force of 0.5 kgf or less. Since it was made slidable, when processing the terminal and intermediate part of a sheath electric wire, a terminal or an intermediate part can be processed by sliding a sheath on a core. Therefore, compared to conventional sheathed wires, the processing range of the sheath is narrowed, so that the area where the exposed core can be covered with the protective material is also reduced, reducing the work man-hours and reducing the amount of protective material used. Down is achieved.
Further, it is not necessary to cut and tear the sheath in the longitudinal direction, and problems such as core damage do not occur and the reliability is improved.

Hereinafter, an embodiment of a sheath wire of the present invention with reference to FIGS.

The sheath wire 11 according to one embodiment of the present invention to be described below has a structure substantially the same as that shown in FIGS. 6 and 7, and includes two cores (insulating cores ) in which the conductor 3 is covered with the insulator 4. Line) 2 is a structure in which a sheath 5 is formed on the outer periphery of resin by extrusion molding of resin. The sheath 5 is provided mainly for the purpose of mechanical protection. Concretely describing the size and material of the sheathed electric wire 11 of the embodiment, the core 5 having a nominal thickness of 0.5 mm ² and a finished outer diameter of 1.55 mm having ^two cores 2 arranged in parallel and a thickness of 0.8 mm is provided. This is a sheathed electric wire 11 which is covered by extrusion molding and has a major axis of 4.8 mm and a minor axis of 3.2 mm as a whole. Insulator 3 and sheath 5 in the present invention are the same kind of resin, but in the examples both are styrene thermoplastic elastomers.

In the present invention, the adhesive force between the core 2 and the sheath 5 is reduced, and the entire length of at least 1 meter apart of the sheath 5 can be slid with respect to the core with a force of 0.5 kgf or less. Provided. In this case, when providing the sheath 5 by extrusion molding of resin on the outer periphery of the core 2, an adhesion reducing means for reducing the adhesion between the core 2 and the sheath 5 is employed.

  As an adhesion reducing means for reducing the adhesion between the core 2 and the sheath 5, the resin temperature when extruding the resin of the sheath material to the outer periphery of the core 2 is near the lower limit of the extrudable temperature (the insulator 3 and the sheath 5 are made of styrenic heat). In the case of a plastic elastomer, there is a method of setting to 200 ° C., for example. There is also a method in which the coating resin (sheath) is quenched immediately after the resin is extruded to the outer periphery of the core 2.

There is also a method of reducing the adhesion between the core and the sheath by improving the extrusion head of the extruder. FIG. 1 shows a simplified view of the main part of an extrusion head 10 of an extrusion molding machine. The tip of a nipple 9 is arranged near the outlet of the die 8, and the space between the tip 9 a of the nipple 9 and the die 8. The resin is extruded from the outer periphery of the core 2 so that the outer periphery of the core 2 fed in the direction of the arrow in the nipple 9 is covered as a sheath.
2A is an enlarged view of the tip portion of the nipple 9, FIG. 2B is a cross-sectional view taken along the line BB of FIG. 2B, L is the length of the tip portion 9a in the extrusion direction, and T is It is the thickness of the cylindrical front-end | tip part 9a. Reference numeral 8 a denotes the inner surface of the outlet opening of the die 8. By appropriately setting the length L and the thickness T, it is possible to reduce the adhesion between the core and the sheath. As a result of various experiments in the case of manufacturing the sheath wire 11 of the size and material described above, when the length L of the tip portion 9a of the nipple 9 is made substantially the same as the long diameter of the finished diameter of the sheath wire, the core and the sheath It was effective in reducing the adhesion between the two. In addition, reducing the nipple thickness T, for example, 0.2 mm or less, was also effective in reducing the adhesion between the core and the sheath. Therefore, if the sheath is coated by extrusion molding using the above methods alone or in combination, the core and the sheath can be used even if the core and the sheath are both rubber materials having a large frictional force such as thermoplastic elastomer. Can be made sufficiently small so that the entire length of at least 1 meter apart of the sheath can be slid with respect to the core with a force of 0.5 kgf or less .

If the insulator and the sheath are different types of resin, it is relatively easy to reduce the adhesion between the core and the sheath during resin extrusion, but in the case of the same type of resin, Therefore, it is not easy to realize a sufficiently low adhesion force by adopting general extrusion conditions. However, by appropriately selecting the extrusion conditions that reduce the adhesion force or combining them, the entire length of 1 m or more of the sheath is low enough to slide on the core with a force of 0.5 kgf or less. It is possible to achieve adhesion. Thus, the present invention has significance when the insulator and the sheath are the same kind of resin.
The idea of sliding a 1 meter long part, etc., was never found in a conventional sheathed wire, but the force of 0.5 kgf required to slide the sheath is a very light force. In particular, the size is such that almost no force is required, and is considerably smaller than the adhesion force between the core and the sheath in the conventional sheathed electric wire. The force required for the slide is sufficiently small, and it is very unlikely to depend on the diameter of the entire core (or sheath inner diameter). For example, in the case of a sheathed wire used for automobile wiring, regardless of the wire diameter The above low adhesion can be realized.
In addition, when the number of cores is as large as three or more, the contour of the entire core approaches a circle and the sheath contour approaches a circle, but it can be said that the sheath becomes easier to slide as the sheath contour approaches a circle. On the other hand, when the number of cores is two, the contour of the entire core becomes flat and the sheath contour becomes flat, but the flat sheath is difficult to slide. Thus, the present invention is meaningful when the number of cores is two and the difficulty of sliding the sheath becomes high.

Actually, by manufacturing the sheathed wire by adopting the above method, for example, the force required to pull out the sheath of the sheathed wire having a length of 1 m from the core could be suppressed to about 0.5 kgf at the maximum. (The length of the sheath is about 0.05 kgf at a length of 10 cm) . This force is surely below the breaking load value of the core, but does not stay there, and is small enough that it can be easily slid and pulled out of the core without tearing the sheath.
On the other hand, in the case of a sheath wire of the same size and material manufactured by the conventional method, the force required to pull out the sheath is approximately 15 kgf, which exceeds the breaking load value of the core. If you try to pull out the core, the core will break.

An example of a method for processing a sheathed wire in the case where the terminals are attached to both ends of the sheathed wire 11 having reduced adhesion between the core 2 and the sheath 5 as described above will be described with reference to FIG. The process up to the stage of attaching the terminal 6 to one end (right side) of the sheathed electric wire 11 is substantially the same as the conventional example described in FIG. That is, the sheath 5 is circularly cut (cut in the circumferential direction) in the vicinity of one end (position A in FIG. 3A) by the blade of the cutter, and the core 2 is exposed by removing the sheath on the end side ( Next, the insulator 4 is removed and the conductor 3 is extracted (FIG. 3C), and then the terminal 6 is attached to the conductor 3 (FIG. 3D).
In the present invention, the sheath electric wire 11 with reduced adhesion between the core 2 and the sheath 5 is used, and even if the sheath portion is long, the sheath 5 can be easily slid on the core 2, The core 2 of the other terminal can be exposed by sliding the remaining sheath 5 after the ring cutting to the terminal side (in the direction of arrow B) to which the terminal 6 is first attached (FIG. 3 (e)). Thereafter, the conductor 3 is led out and the terminal 6 is attached to the other terminal (left side) in the same manner as described above, and then the sheath 5 is slid back to the middle position of the electric wire (FIGS. 3 (F) to (G)), then The exposed core 2 is covered with a protective material 7 such as a tape (FIG. 3 (H)).

As described above, according to the sheathed electric wire 11 of the present invention, since a sufficiently long portion of the sheath 5 can be easily slid on the core 2, one terminal portion of the sheath 5 can be used when terminals are attached to both ends. The terminal 6 can be attached to both ends of the sheathed electric wire 11 simply by removing. Therefore, the processing range of the sheath 5 is narrow, and the range in which the exposed core 2 can be covered with the protective material 7 is also small. Thereby, an operation man-hour can be reduced and the usage-amount of the protective material 7 can be reduced.

A comparison of the effects of the sheathed electric wire 11 of the present invention described above with specific values in the case of the conventional example is as follows.
When the length of the electric wire is 127 cm, it is necessary to remove the sheath of one end by about 32 cm in the conventional processing method, and the sheath of about 64 cm is removed at both ends. Along with this, the length of the protective material covering the exposed core after the terminal attachment is about 30 cm.
On the other hand, according to the present invention, it is only necessary to remove the sheath at one end of about 32 cm. Therefore, the length of the protective material covering the exposed core at both ends of the electric wire is about 13 cm. The processing range is greatly reduced, and the amount of protective material used can be greatly reduced.
Although the degree of the effect differs slightly depending on the size and length of the sheathed electric wire, the processing range of the sheath can be suppressed to 60 to 70% of the conventional range.

In addition, in the said embodiment, when attaching the terminal 6 to one terminal of the sheath electric wire 11, the one end side part of the sheath 5 is cut off and removed, and the core 2 of the one end side is exposed, but FIG. ), (B), the core 5 on one end side may be exposed by simply sliding the sheath 5 to the other end side (left side) without cutting the ring. In this case, in the state of FIG. 4B, or after appropriately cutting off the portion of the sheath 5 that protrudes from the core 2, the terminal 6 is attached to the end of the exposed core 2 on the one end side (right side). FIG. 4 (c) corresponds to the stage of FIG. 3 (c), and the subsequent operations are the same as those in FIGS.
According to this method, the operation for cutting the sheath 5 for removing the sheath 5 is not necessary, so that the risk of damaging the core 2 is reduced.

  Next, an example of a sheath wire processing method in the case where a branch terminal is attached to the intermediate portion of the sheath wire 11 will be described with reference to FIG. First, the sheath 5 is circularly cut at a predetermined position (C position in FIG. 5 (a)) of the intermediate portion of the sheathed electric wire 11 by the blade of the cutter, and one side of the rounded sheath 5 (right side in FIG. 5 (a)). The part is slid to one side on the core 2 to expose the core 2 in the middle part of the electric wire, and the part of the sheath 5 that protrudes from the core 2 is cut off at an appropriate place (position D in FIG. 5B). (Fig. 5 (b), (c)). Next, if necessary, the left and right sheaths 5 are respectively slid toward the terminal side to expose the intermediate conductor 3 in a state where the exposed length of the intermediate core 2 is increased (FIG. 5 (d)), and then the conductor After the terminal 6 is attached to 3, the sheath 5 is returned to the center side (FIG. 3 (e)). In addition, subsequent protective material coating was omitted

According to the sheath wire intermediate portion processing method of FIG. 5 in the case where a terminal is attached to the intermediate portion of the sheathed electric wire 11, the sheath 5 can be appropriately slid on the core 2. By cutting the sheath 5 in a ring and sliding one end of the sheath 5, the core 2 in the middle portion of the electric wire is exposed and the terminal 6 can be attached. Therefore, the processing range of the sheath 5 is narrowed, the range in which the exposed core 2 is covered with the protective material 7 is small, and the number of work steps and the amount of the protective material 7 used are reduced.
Thus, it is unnecessary to expose the intermediate core 2 by incising and tearing the sheath in the longitudinal direction at the intermediate portion of the electric wire as in the conventional intermediate portion processing method of FIG. 10, and the sheath material is torn such as rubber. Even in the case of difficult materials, problems such as core damage do not occur.

  Note that FIG. 5 shows only the processing of the middle portion of the electric wire and does not consider terminal processing. However, when terminal processing is performed, the sheath 5 is slid to expose the core 2 of the terminal portion by a required length. Therefore, the operation of attaching the terminal to the terminal can be easily performed.

If both the core insulator and the sheath are made of a rubber material, the adhesion between the core and the sheath is large, and it is difficult to slide the sheath on the core. The effect of the present invention is remarkably exhibited when the sheath 5 is a thermoplastic elastomer that is the same rubber material, but is not necessarily limited to the rubber material. For example, even when both the insulator 3 and the sheath 5 are made of vinyl chloride resin, the adhesive force between the core and the sheath is large, so that it is effective even when the insulator 3 and the sheath 5 are both made of vinyl chloride resin. It is.

It is principal part sectional drawing which shows an example of the extrusion head for coat | covering a sheath on an outer periphery of a core by extrusion molding when manufacturing the sheath electric wire of this invention. (A) is the figure which expanded the front-end | tip part of the nipple of FIG. 1, (b) is BB sectional drawing of (a). It is a figure which shows an example of the processing method of the sheath electric wire at the time of attaching a terminal to the both ends of the sheath electric wire of this invention, and is a figure explaining the point which attaches a terminal to both the ends of a sheath electric wire. It is a figure explaining the other example of the method of the sheath removal at the time of exposing the core of the one end side of a sheath electric wire in FIG. An example of the processing method of the sheath electric wire at the time of attaching a terminal to the middle part of the sheath electric wire of the present invention is shown, and is a figure explaining the point which attaches a terminal to the middle part of a sheath electric wire. It is a top view of the edge part vicinity which led the conductor of the sheath electric wire, and is a figure common to this invention and a prior art example. It is an AA expanded sectional view of FIG. It is a figure explaining the terminal processing method of the conventional sheathed electric wire. It is a figure explaining the 1st method of the intermediate part processing method of the conventional sheathed electric wire. It is a figure explaining the 2nd method of the intermediate part processing method of the conventional sheathed electric wire. It is a figure explaining the 3rd method of the intermediate part processing method of the conventional sheathed electric wire.

Explanation of symbols

2 Core 3 Conductor 4 Insulator 5 Sheath 6 Terminal 7 Protective Material 8 Die 9 Nipple 9a Nipple Tip 10 Extrusion Head 11 Sheath Electric Wire L Nipple Tip Length T Nipple Tip Thickness

Claims (7)

In a sheathed electric wire in which a sheath is formed by extruding resin on the outer periphery of a core whose conductor is covered with an insulator,
A sheathed electric wire characterized in that the adhesion between the core and the sheath is reduced and the sheath is slidable with respect to the core.   The sheathed electric wire according to claim 1, wherein the separated length part of at least 1 meter is slidable with respect to the core as a whole.   The sheath electric wire according to claim 1, wherein a force required for pulling out the entire length portion of at least 1 meter or more separated from the core is smaller than a breaking load of the core.   The sheath electric wire according to claim 1, 2 or 3, wherein both the insulator and the sheath are made of the same material.   4. The sheathed electric wire according to claim 1, wherein the insulator and the sheath are both made of a thermoplastic elastomer.   The sheath electric wire according to claim 1, 2 or 3, wherein the insulator and the sheath are both made of vinyl chloride resin.   When manufacturing a sheathed electric wire by providing a sheath by extrusion molding of a resin on the outer periphery of a core whose conductor is covered with an insulator, the sheath is formed by extrusion molding having an adhesion reducing means for reducing the adhesion between the core and the sheath. A method for manufacturing a sheathed wire, comprising: providing a sheathed wire.

Images