JPH11216768A - Hollow double wall structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate to grasp insert members from the outside and to take them out when a hollow double wall structure is discarded and to surely classify a plastic material and a metal material. SOLUTION: A hollow double wall structure 1 is constituted of a surface wall 2, a back wall 3 facing the surface wall 2 at an interval and surrounding walls 4 forming a hollow part between the surface wall 2 and the back wall 3. An insert member in a continuous length being prepd. by sheathing a metal body in a continuous length with a plastic cylindrical body is inserted between facing surrounding walls 4. The end faces of the insert member 7 on the facing surrounding walls 4 are exposed outside. The insert member 7 is held on the back wall 3 by surrounding it with the surrounding walls integrally connected with the back wall 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow double-walled structure obtained by blow molding a thermoplastic, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, an inner rib formed in a hollow portion of a plastic hollow double-walled structure constituting an interior wall, a partition, a door of a building, a floor trunk lid or a rear parcel shelf of an automobile, and the like. A technique for improving strength and rigidity by inserting a flat and curved metal rod into the plate is described in JP-A-9-155957.

[0003]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 9-15 / 1997
The technology described in Japanese Patent No. 5957 was developed by the present applicant, but as a result of subsequent studies, it has been found that the following problems mainly exist in blow molding.

That is, in a case where a metal rod is inserted into a plastic molded body, such as a hollow double-walled structure of this kind, a plastic material and a metal material are reused at the time of disposal, after recycling of the material. It is necessary to separate the metal material from the plastic material because the metal body is completely buried inside the plastic molding and the metal body is not visible at all from the outside. Work is not easy.

Therefore, the present invention is intended to solve the above-mentioned problems, and even if the strength and rigidity are improved by inserting a long insert member, the present invention is not limited to this. A hollow double-walled structure is formed by covering a long metal body with a plastic tubular body, inserting the insert member between opposed peripheral walls, and exposing the end of the insert member to the outside. It is an object of the present invention to make it easy to grasp the insert member from the outside and take out the long metal body from the outside at the time of disposal, so that the plastic material and the metal material can be surely separated.

[0006]

In order to achieve the above object, a hollow double-walled structure according to the present invention comprises a front wall, a back wall opposed to the front wall at an interval, a front wall and a back wall. And a peripheral wall forming a hollow portion between the hollow double-walled structure and a hollow insert, in which a long metal member is covered with a plastic tubular body. The insert member is inserted between the surrounding peripheral walls and the end of the insert member is exposed to the outside, and the insert member is surrounded by a surrounding wall integrally connected to the back wall and held on the back wall. Is what you do.

A method for manufacturing a hollow double-walled structure according to the present invention includes a front wall, a back wall opposed to the front wall at an interval, and a periphery forming a hollow portion between the front wall and the back wall. A method of blow molding a hollow double-walled structure composed of a wall and
In the cavity of the mold that forms the back wall of the pair of split molds, insert a long insert member in which a long metal body is covered with a plastic cylindrical body, and then blow molding between the surrounding peripheral walls. By molding the hollow double-walled structure in which the elongated insert member is inserted and surrounded by the surrounding wall integrally connected to the back wall and held by the back wall, the end of the insert member is exposed to the outside. Characterized in that a hollow double-walled structure is obtained.

In the method of manufacturing a hollow double-walled structure according to the present invention, a holding piece is provided on a plastic tubular body of an insert member, and the holding piece is engaged with a groove formed in a cavity of a mold. It is preferred to hold.

[0009]

1 and 2 show a hollow double-walled structure according to an embodiment of the present invention. FIG. 1 is an overall perspective view as viewed from the back side, and FIG. It is an XX enlarged sectional view.

FIGS. 3 to 5 show a blow molding mode of a hollow double-walled structure according to an embodiment of the present invention. FIG. 3 is a sectional view showing a process before closing a mold. FIG. FIG. 5 is an enlarged sectional view taken along the line Y-Y, and FIG. 5 is a perspective view of the insert member.

FIG. 6 is a perspective view of a part of a hollow double-wall structure according to another embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a hollow double-walled structure. The hollow double-walled structure 1 has a panel shape,
Reference numeral 2 denotes a front wall, 3 denotes a back wall, and 4 denotes a peripheral wall. As shown in FIG. 2, the back wall 3 faces the front wall 2 at an interval. A hollow portion 5 is formed between 2 and the back wall 3. A fiber sheet 6 is attached to the entire surface of the front wall 2 so as to cover a part of the peripheral wall 4.
The fiber sheet 6 is attached in a blow molding step of the hollow double-wall structure 1 as described later.

An elongated insert member 7 is inserted into the hollow portion 5 of the hollow double-walled structure 1 so as to extend between the peripheral walls 4 facing each other. As shown in FIG. 2, the insert member 7 is formed by covering a long metal body 8 of a straight metal pipe with a plastic tubular body 9. As shown in FIG. 2, the insert member 7 is surrounded by a surrounding wall 10 integrally connected to the back wall 3 and is held integrally with the back wall 3. A part of the plastic tubular body 9 of the member 7 is exposed on the same plane as the back wall 3. Reference numeral 11 denotes the exposed portion. A gap 12 is provided between the elongated metal body 8 of the insert member 7 and the exposed portion 11 of the plastic tubular body 9.

As shown in FIG.
The insertion site of the insert member 7 forms an open recess 13, and the end of the elongated metal body 8 of the insert member 7 is exposed to the outside. The end of the insert member 7 is recessed inward from the outer surface of the peripheral wall 4 by the opening recess 13.
The end of the long metal body 8 of the insert member 7 may be sealed by inserting a cap-shaped seal (not shown).

In the embodiment shown in FIGS. 1 and 2,
Although a pipe having a circular cross section has been exemplified as the long metal body 8 of the insert member 7, the insert member 7 is not limited to this. For example, as shown in FIG. You can also. In the embodiment shown in FIG. 6, the plastic tubular body 9 that covers the strip-shaped long metal body 8 has a polygonal shape.

The hollow double-walled structure 1 according to the present invention comprises AB
S resin, modified polyphenylene oxide resin, polycarbonate resin, polyamide resin, polypropylene resin,
It is made of a blowable thermoplastic resin such as a polyethylene resin. The plastic tubular body 9 constituting the insert member 7 is made of the same material as that of the hollow double-walled structure 1, or a filler such as glass fiber, calcium carbonate, talc, mica or the like is contained in these thermoplastic resins. A glass wool formed by collecting a large number of fibers such as a thermoplastic resin or glass, or a foam formed from a fiber.

The hollow double-walled structure 1 according to the present invention is shown in FIG.
And blow molding in the mode shown in FIG. Reference numeral 14 denotes one split mold for forming the front wall 2, 15 denotes another split mold for forming the back wall 3, and a cavity 16 of the other split mold 15 holds the insert member 7. As shown in FIG. 4, the holding of the insert member 7 is performed by providing a holding piece 17 integrally with the exposed portion 11 of the plastic tubular body 9, and attaching the holding piece 17 to the cavity 16 of the other split mold 15. This is performed by inserting it into the groove 18. Holding piece 1
7 may be flaky. The holding piece 17 is cut off by an appropriate means after blow molding. In the embodiment shown in FIG. 6, the holding piece 17 is shown by a virtual line before being cut off.

At the time of blow molding, as shown in FIG. 3, the insert member 7 is inserted into the cavity 16 of the other split mold 15 and the fiber sheet 6 is arranged so as to face one mold 14. Next, the parison 20 is arranged between the extrusion head 19 and the molds 14 and 15.

Next, after closing the mold, a pressure fluid is blown into the parison 20 to perform blow molding. After blow molding, the surfaces of the front wall 2, the back wall 3 and the peripheral wall 4 constituting the hollow double-wall structure 1 are cooled by cooling the split dies 14 and 15,
The mold is opened by cooling and solidifying to the extent that the shape is maintained, and the hollow double-walled structure 1 is taken out of the split molds 14 and 15.

As described above, in the blow-molded hollow double-walled structure 1, the long metal body 8 of the insert member 7 inserted into the hollow portion 5 is covered with a plastic tubular body 9. Therefore, the elongated metal body 8 is not subjected to a tightening action due to cooling shrinkage after blow molding of the hollow double-walled structure 1. For this reason, at the time of disposal of the hollow double-walled structure 1, in addition to being able to reliably recognize that the elongated metal body 8 is inserted as the insert member 7 into the hollow double-walled structure 1, the long double-walled structure 1 can be recognized. Since the metal body 8 can be pulled out from the insert member 7, the long metal body 8 can be easily separated from the hollow double-walled structure 1 made of a thermoplastic resin.

[0021]

According to the present invention, even if the strength and rigidity are improved by inserting a long insert member, the long metal body is made of a plastic tubular body as the insert member. When the hollow double-walled structure is discarded, the insert member can be grasped from the outside and inserted, by inserting this insert member between the opposing peripheral walls and exposing the end of the insert member to the outside. A hollow double-walled structure capable of easily separating a long metal body and separating a plastic material and a metal material reliably is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a hollow double-walled structure according to an embodiment of the present invention as viewed from the back side.

FIG. 2 is an enlarged sectional view taken along line XX of FIG.

FIG. 3 is a partial cross-sectional view showing a blow molding mode of the hollow double-walled structure according to the embodiment of the present invention, showing a step before closing the mold.

FIG. 4 is an enlarged sectional view taken along line YY of FIG. 3;

FIG. 5 is a partial perspective view of an insert member.

FIG. 6 is a perspective view of a hollow double-walled structure according to another embodiment of the present invention as viewed from the back side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow double wall structure 2 Front wall 3 Back wall 4 Peripheral wall 5 Hollow part 6 Fiber sheet 7 Insert member 8 Long metal body 9 Plastic cylindrical body 10 Surrounding wall 11 Exposed part 12 Gap part 13 Opening concave part 14 One side Split mold 15 of the other split mold 16 cavity 17 holding piece 18 groove 19 extrusion head 20 parison

Claims (3)

[Claims] 1. A hollow double-walled structure comprising a front wall, a back wall facing the front wall at an interval, and a peripheral wall forming a hollow portion between the front wall and the back wall. Along the inside of the hollow portion, a long insert member in which a long metal body is covered with a plastic tubular body is inserted across the opposing peripheral walls, and the end of the insert member is exposed to the outside,
The hollow double-walled structure according to claim 1, wherein the insert member is surrounded by an enclosing wall integrally connected to the back wall and held by the back wall. 2. A hollow double-walled structure comprising a front wall, a back wall opposed to the front wall at an interval, and a peripheral wall forming a hollow portion between the front wall and the back wall. A method of blow molding, in which a long insert member in which a long metal body is covered with a plastic tubular body is inserted into a cavity of a mold that forms a back wall of a pair of split molds, and then blown. An elongated insert member is inserted between the peripheral walls opposed to each other by molding, and the hollow double-walled structure surrounded by the surrounding wall integrally connected to the back wall and held by the back wall is formed. A hollow double-walled structure having an end exposed to the outside. 3. The hollow double according to claim 2, wherein a holding piece is provided on the plastic tubular body of the insert member, and the holding piece is engaged with a groove formed in a cavity of the mold and held. A method for manufacturing a wall structure.