JP2003063741A - Winding core and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a winding core, capable of imparting a stepped flaw onto a sheet, in which a step is not generated when the sheet is started to be wound on a winding core; and a manufacturing method therefor. SOLUTION: In the winding core, a recessed line is formed in a length direction of an outer surface of a cylindrical body. A shape of cross section of the recessed line comprises a vertical surface in an approximate diameter direction of the cylindrical body; and a circular surface being approximately the same circle to the outer surface of the cylindrical body.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a winding core and a method for manufacturing the same.

[0002]

2. Description of the Related Art Usually, a long film or sheet (hereinafter, referred to as a sheet) is wound around a core such as a paper tube and manufactured, stored and transported as a wound body. A vinyl leather sheet used as an interior material for automobiles. For a flexible sheet like
The trace of the step at the beginning of winding on the core of the sheet sticks to the sheet,
It has a drawback that it cannot be used up to several meters from the beginning of winding and up to ten meters if the sheet is thick.

In order to eliminate the above-mentioned step marks, it has been practiced to wrap the sheet by sticking paper, a plastic sheet or the like on the step at the beginning of the sheet winding, but it is difficult to even stick the paper or plastic sheet evenly. Yes,
It was not possible to eliminate the step, and it was not possible to eliminate the mark of the step on the sheet.

[0004]

SUMMARY OF THE INVENTION In view of the above drawbacks, an object of the present invention is to provide a winding core and a manufacturing method thereof in which a step does not occur when the sheet is wound around the winding core and the sheet does not have a step. To provide.

[0005]

According to a first aspect of the present invention, there is provided a winding core in which a recess is formed in a length direction of an outer surface of a cylindrical body, and the cross section of the recess has a cylindrical shape. It is characterized by comprising a vertical surface in a substantially diametrical direction and an arc surface which is substantially the same circle as the outer surface of the cylindrical body.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A winding core according to the first aspect of the present invention will be described with reference to the drawings. 1 is a perspective view showing an example of a winding core of the invention according to claim 1, and FIG. 2 is an enlarged side view of A in FIG.

In the figure, reference numeral 1 is a winding core, in which a recess 12 is formed in the lengthwise direction of the outer surface of a cylindrical body 11. The recessed line 12 is formed by a vertical surface 13 in the substantially diametrical direction of the cylindrical body 11 and an arc surface 14 that is substantially the same circle as the outer surface of the cylindrical body 11.

It is sufficient that the vertical surface 13 is formed in a substantially diametrical direction as a whole, and the surface is preferably smooth, but may have irregularities. Further, it is preferable that the depth thereof is substantially the same as the thickness of the sheet to be wound. The arc surface 14 is deepest on the vertical surface 13 side and becomes shallower in the opposite direction.
The arc surface is also preferably smooth, but may have irregularities to the extent that no marks are transferred to the sheet.

If the depth of the vertical surface 13 is substantially the same as the thickness of the sheet to be wound, when the sheet is wound, the deepest portion (vertical surface portion) of the groove is filled with the sheet to be flush with the arc of the groove. Since the surface is substantially the same circle as the outer surface of the cylindrical body, it can be wound without a step.

The material of the core is paper; thermoplastic resin such as vinyl chloride resin, polyethylene resin, polypropylene resin, F
Although any material conventionally used as a core material such as RP and thermosetting resin such as epoxy resin can be used,
A thermoplastic resin is preferable for forming a uniform and accurate groove, and a vinyl chloride resin is particularly preferable.

Any known manufacturing method may be adopted as the method for manufacturing the above-mentioned winding core. For example, a method of molding and shaping in a mold, a cylindrical body is molded, and then a recess is formed by pressing, cutting or the like. However, it is difficult to connect the vertical surface and the depth, and to connect the vertical surface and the arc surface at a right angle. Therefore, in order to manufacture the thermoplastic resin, it is preferable to extrude the thermoplastic resin into a cylindrical body and perform cutting when the cylindrical body is cooled to a specific temperature.

That is, in the method for manufacturing a core according to the second aspect of the present invention, the melt extruded thermoplastic resin cylindrical body is cooled and the cylindrical shape is formed by cutting in a temperature range of 40 to 80 ° C. It is characterized in that a concave streak is formed in the length direction of the outer surface of the body.

A method of manufacturing a winding core according to the second aspect of the present invention will be described with reference to the drawings. FIG. 3 is a schematic view showing an example of a method of manufacturing a winding core according to the second aspect of the invention.

In the figure, reference numeral 2 is an extruder for melt-molding a thermoplastic resin into a cylindrical shape. The melt extruded thermoplastic resin cylindrical body 11 is sized by the sizing device 3, and then cooled by the cooling device 4 with cooling water, cooling gas or the like. Cooled thermoplastic resin cylindrical body 12
Is cut by the cutting device 5 in the temperature range of 40 to 80 [deg.] C. to form a groove and is cut to obtain a core.

When the temperature of cutting is high, it becomes difficult to form a groove having a constant shape, and when the temperature is low, the thermoplastic resin becomes hard and cutting itself becomes difficult. Therefore, cutting is carried out in the temperature range of 40 to 80 ° C. When the thermoplastic resin is vinyl chloride resin, the temperature is preferably 47 to 67 ° C.

The cutting may be performed by heating the once cooled cylindrical body instead of in-line, but it is more efficient to perform in-line cutting and a clear and uniform concave line can be formed. Therefore, it is preferable.

The cutting process may be performed by any conventionally known cutting device, but is preferably performed by the cutting device 5 shown in FIG. The cutting device 5 includes a fixed die 51 and a movable die 52. The fixed mold 51 is composed of split fixed molds 51a and 51b having a semi-cylindrical inner surface. The fixed fixed molds 51a and 51b are fixed by bolts 53, and a molding passage 54 through which the cylindrical body can pass is formed inside. ing.

The inner surface of the movable die 52 has an arcuate surface having the same shape as the molding passage 54. One end 52a of the movable die 52
The vicinity of the inner surface of is formed into a flat surface in the substantially diametrical direction of the molding passage 54, and the side surface is provided with a cutting portion 52b.

FIG. 5 is a vertical sectional view showing the shape of the cutting portion 52b. The cutting portion 52b has a rake angle θ and a second angle π.

A standing portion 52c is provided near the outer surface of the one end 52a of the movable die 52 in the direction of the arc surface of the molding passage 54, and the standing portion 52c has a bolt penetrating the standing portion 52c. 55 is attached. The movable die 52 has one end 52a.
So as to project inward of the molding passage 54, and the other end of the bolt 5
6 is pivotally supported on the side surface of the split fixed mold 51b.

Reference numeral 51c is a rib extending outward from the fixed fixed die 51b, and a tip portion of the rib 51c is formed with a bent portion 51d which is bent so as to cover the outside of the movable die 51.
The bent portion 51d has a bolt 57 that penetrates the bent portion 51d.
Is attached.

Therefore, the tip of the bolt 55 is fixed to the split fixed die 5.
1a is brought into contact with the outer surface of the bolt 1 and the tip of the bolt 57 is attached to the movable mold 52
The movable die 52 by fixing it to the outer surface of
Determine the shape of the groove to be cut.

Reference numeral 51e is a standing portion that is erected at the tip of a rib (not shown) extending outward from the split fixed die 51a toward the molding passage direction. The tip of the standing portion 51e is movable. The guide portion 51f is formed by bending in the mold 52 direction. A bolt 58 penetrating the guide portion 51f is attached to the guide portion 51f. By pressing the movable die 52 with the bolt 58 and pressing the movable die 52 against the rib 51c, the movable die 52 is fixed so as not to move in the molding passage 54 direction.

The core of the present invention can be efficiently obtained by using the above cutting device 5 and performing in-line cutting during the melt extrusion molding of the thermoplastic resin cylindrical body. In particular,
By fixing the movable die 52 with the bolts 55, 57 and 58, it is possible to obtain a winding core having a uniform and highly accurate recess.

[0025]

The structure of the core of the present invention is as described above. Therefore, when the sheet starts to be rolled, no step is formed and the sheet is not marked with the step, and therefore it is as flexible as a vinyl leather sheet. Even a sheet can be used efficiently until the beginning of winding.

Further, since the structure of the method of manufacturing the winding core of the present invention is as described above, it is possible to efficiently form the concave stripes, and the formed concave stripes are accurate and uniform.

[0027]

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a winding core according to the first aspect of the invention.

FIG. 2 is an enlarged side view of A in FIG.

FIG. 3 is a schematic view showing an example of a method of manufacturing a winding core according to the second aspect of the invention.

FIG. 4 is a perspective view showing an example of a cutting device.

FIG. 5 is a vertical cross-sectional view showing the shape of a cutting portion.

[Explanation of symbols]

1 core 11 cylindrical body 12 concave line 13 Vertical plane 14 arc surface 2 extruder 3 sizing device 4 Cooling device 5 cutting equipment 51 fixed type 52 movable 53, 55, 56, 57, 58 bolts 54 molding passage

Claims (3)

[Claims] 1. A cylindrical body is formed with a concave line in a length direction of an outer surface, and the cross-sectional shape of the concave line is a vertical surface in a substantially diametrical direction of the cylindrical body and an outer surface of the cylindrical body. A winding core, characterized in that it comprises arcuate surfaces that are substantially the same circle. 2. Forming a concave line in the lengthwise direction of the outer surface of the cylindrical body by cooling the melt-extruded cylindrical body made of a thermoplastic resin and cutting in the temperature range of 40 to 80 ° C. The method for producing a winding core according to claim 1, wherein 3. A fixed die having a molding passage through which a cylindrical body can pass, and the vicinity of the inner surface of one end is a substantially diametrical plane of the molding passage, and the inner surface has the same shape as the molding passage. The movable die, which is an arcuate surface of the movable die, has one end that can freely project inward of the forming passage and the other end of the movable die that is axially supported by the fixed die. The method for manufacturing a winding core according to claim 2, wherein the cylindrical body is cut by being passed.