JPH064282B2 - Laminating tape molding method and die used therefor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a laminate tape of a laminated sheath type cable into a tubular shape, and a die used for the method.

[Conventional technology and its problems]

A laminated sheath type cable is formed by molding a laminated tape, which is a laminate of aluminum foil and polyethylene film (PE), on the outer circumference of the cable core, with the PE layer on the outside, and heat-sealing the overlapped portion. Then, an outer cover made of high-density polyethylene (HDPE) or the like is extrusion-molded directly on the outer cover, and the inside of the outer cover and the PE layer of the laminating tape are
It is formed by fusing with heat and pressure during extrusion molding of the jacket.

The step of attaching the laminating tape to the cable core, that is, the method of molding the laminating tape into a tubular shape is as follows. First, as shown in FIGS. 1 and 2, a laminating tape forming roll 1, a forming gutter 2, a forming die 3, Heating blower 4,
The pressing roller 5 is provided in order in the traveling direction of the cable core a. As shown in FIG. 5, the forming roll 1 is composed of a drum-shaped male roll 1a and a drum-shaped female roll 1b which are orthogonal to the running direction, and both rolls 1a and 1b have an uneven curved peripheral surface 1a ', When the laminating tape b is fed into the 1b ', the laminating tape b is formed into a widthwise cross-shaped shape by the pressure contact of the concave and convex curved peripheral surfaces 1a' and 1b ', and the laminating tape b runs on the forming gutter 2. The laminate tape b is formed into a package shape so as to wrap the core a, and further, the laminate tape b is brought into pressure contact with the cable core a while pressing the cylinder die to a desired diameter with the molding die 3, and the laminate tape b is heated by the heating blower 4. The overlapping portion is heated, and the release roller 5 is pressed and heat-sealed (seamed).

In this molding step, the finish degree of the tubular molding of the laminate tape b is largely influenced by the inner surface shape of the die 3, that is, the land shape and its arrangement.

For this reason, the inventors of the present invention also use this as the introduction angle of the die 3,
Various studies have been conducted so that the desired cylindrical shape can be formed by changing the land length and the exit angle. But,
According to such an idea, in order to obtain a cylindrical laminated tape b which is stretched and repelled due to its elasticity, and which does not have a good outer diameter (shape) and which does not have a floating seam portion. I had a hard time.

In view of the above points, an object of the present invention is to enable tubular molding of a laminated tape to be performed easily and accurately.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, in the molding method according to the present invention, in the above-mentioned method, the draw molding using a molding die is a circular line contact around the cable core, and the line contact is the running. The number of steps is set along the direction and the diameter is gradually reduced.

Further, in the above-mentioned forming die used for the forming method, it is composed of a plurality of truncated cones, and the small diameter portion of the land is an inclined surface that gradually expands toward the outside. Is configured such that the land large-diameter portion is fitted on the same shaft as the upstream side in the traveling direction, and the small-diameter land portion of each truncated cone has a small diameter in the downstream direction in the traveling direction. is there.

[Action]

In the present invention thus constituted, the laminate tape is molded in the same manner as in the prior art. However, the laminate tape is sequentially formed by a plurality of stages of circular line contact at the time of drawing using the die. It is squeezed in various ways, and repulsion due to its elasticity is prevented. For this reason, no floating (separation of lines on both sides of the tape of the overlapping portion) occurs at the cylindrical overlapping portion of the laminated tape.

Further, since the drawing action is performed by the line contact, the contact resistance with the laminating tape is small, and the partial sagging (wrinkles) of the laminating tape does not occur.

〔Example〕

First, the forming die 3 will be described. As shown in FIG. 3, a plurality of truncated cone cylinders 3 ₁ , 3 _2, ... Are fitted together. The cylinder 3 ₁ ... (S3
The inner surface is hard muromu plating. Further, as shown in FIG. 4, the inner surface small-diameter portion 3 _a1 of the cylinder 3 ₁ has an inclined curved surface whose diameter gradually increases toward the outside. With respect to the cylinder 3 _{1 having} this structure, 35 pieces each having the small-diameter portion, A, B and C shown in Table 1 below were manufactured.

From among the plurality of cylinder 3 _{1 ...,} appropriate A according to the diameter of the cable core a, B, suitably a few select cylinder 3 _{1 ...} with C size, as shown in FIG. 3, sky Are fitted to the same shaft, and the small diameter portion 3 _a1 of each cylinder 3 ₁ ...
In the figure, the die 3 is configured so that the diameter gradually decreases to the left.

As shown in FIG. 1 and FIG. 2, this die 3 is set so that its large diameter portion is on the upstream side in the tubular molding process of the laminate tape b, as in the conventional case, and the laminate sheath type cable is set. Was manufactured. At this time, dice 3
In the above, since the small diameter part of each cylinder 3 ₁ expands outward, the laminating tape and the die land make circular line contact, and the expanded diameter part 3 _a1 ... gradually expands. Since the diameter was reduced, it was smoothly gradually squeezed as shown by the chain line in FIG. 3 to form a tubular shape, and the overlapped portions did not float and sagging did not occur.

[Advantages of the Invention] The present invention is configured as described above, prevents the repulsion of the laminating tape in the die, prevents the overlapping portion from floating, and prevents partial sagging. The tape is easily and surely formed into a tube with a high finish accuracy and is covered with the cable core.

[Brief description of drawings]

FIG. 1 is a schematic front view of an embodiment of a method for forming a laminated tape according to the present invention, FIG. 2 is a plan view of the same embodiment, FIG. 3 is an enlarged sectional view of a die of FIG. 1, and FIG. Is an enlarged sectional view of the truncated cone of FIG. 3, and FIG. 5 is a right side view of the forming roll of FIG. 1 ... Laminating tape forming roll, 2 ... Forming gutter, 3 ... Forming die, 3 ₁ , 3 ₂ ... Frustum of cone, 3 _a1 , 3 _a2 ... Small diameter part, 4 ... Heating blower, 5 ... Presser foot Roller, a ... Cable core, b ... Laminated tape.

Claims (2)

[Claims] 1. A cable core is made to travel in a straight line, and a molding roll, a molding gutter, a molding die, a heating means and a pressing roll are sequentially arranged along the traveling path, and the molding roll, the molding gutter and the molding are formed. Guide the laminating tape to the die,
In the method for forming a laminate tape, the laminate tape is formed into a tubular shape so as to wrap the cable core by them, and the overlapping portion of the tubular laminate is heated, and then heat-bonded by pressure contact with the pressing roll. Laminated tape characterized in that the draw-forming using a die is made into circular line contact around the cable core, and the line contact is made into a plurality of stages along the running direction and gradually reduced in diameter. Molding method. 2. The molding die used in the method for forming a laminated tape according to claim 1, comprising a plurality of truncated cones, the small diameter portion of the land of which gradually expands outward. Each of the truncated cones is fitted to the same shaft with the large diameter portion of the land as the upstream side in the traveling direction, and the small diameter portion of each of the truncated cones has the small diameter portion in the downstream side in the traveling direction. Molding die characterized in that the diameter gradually decreases toward the.