JPH0646934U - Blow molding equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] A container-type hollow article with high side wall rigidity is manufactured by blow molding. A first die 21 having a core portion 21a and a second die 22 having an inner surface shape surrounding the core portion 21a.
Blow molding device that is arranged opposite. A slide plate 23 whose tip is a part of the inner surface shape of the second mold is installed on the side of the second mold 22, and a slide plate 24 is installed on the bottom. Each slide plate can protrude to the vicinity of the side surface of the core portion 21a, and the parison 25 is sandwiched and welded between the tip of the slide plate and the surface of the core portion. After welding, the slide plate returns to the initial position (the position where the tip matches the inner surface of the mold), and pressurized air is supplied to the inside of the parison. Inside the parison, ribs (hidden ribs) 11 and 12 are formed which extend continuously from the outer wall of the parison toward the inner wall facing each other and whose tips are welded to the inner wall.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a blow molding device suitable for molding a cooler box or other container-type hollow articles, particularly a container-type hollow article containing hidden ribs.

[0002]

[Prior art]

 For example, a container-type hollow product such as a cooler box used as a cold-keeping box for fishing has a mold having a core portion and a mold having an inner surface shape surrounding the core portion, which are opposed to each other. Molded (blow molding) by closing and sandwiching a parison made of thermoplastic resin, and supplying pressurized air to the inside of the parison so that the parison conforms to the inner surface shape of both molds.

[0003]

[Issues to be solved by the device]

 However, the hollow article thus obtained does not have sufficient wall rigidity, and for example, when the inside of the hollow body is filled with heat-insulating foam beads, the wall pressure bulges and deforms due to the filling pressure. was there.

[0004]

[Means for Solving the Problems]

 The present invention has been made in view of the above problems, and relates to improvement of a blow molding apparatus suitable for manufacturing a container-type hollow article, which comprises a first mold having a core portion and a core portion. A second mold having an inner shape surrounding the second mold is arranged to face each other, and a slide plate having a tip part of the inner surface shape of the second mold is provided on a side part of the second mold in the vicinity of a side surface of the core part. It is characterized in that it is installed so that it can project up to (claim 1). It is optional to install the slide plate on the bottom of the second mold.

In the blow molding apparatus according to the present invention, the slide plate can be installed in the core portion of the first mold (claim 2), and one or more slide rods can be used instead of the slide plate. It can also be installed (claim 3).

[0006]

[Action]

 In the blow molding apparatus according to claim 1, a parison made of a thermoplastic resin is placed between both molds with the tip of the slide plate aligned with the inner surface of the second mold, and both molds are closed. Then, the slide plate is projected to the vicinity of the surface of the core part of the first mold (approximated to a distance not more than twice the parison thickness). Then, the front end of the slide plate pushes one wall of the parison toward the other wall, and the portions sandwiched between the front end of the slide plate and the core surface of the first mold facing each other are welded to each other. . When the welding is completed, the slide plate is pulled in until its tip is aligned with the inner surface of the second mold, and pressurized air is supplied to the inside of the parison almost at the same time, and the parison is placed along the inner surfaces of both molds and the slide plate tip, A container type hollow article is obtained.

The blow molding apparatus according to claim 2 has substantially the same operation as that of the blow molding apparatus according to claim 1, except that the parison is welded near the surface of the core portion of the second mold. Have.

The hidden ribs obtained by the device of the present invention are, for example, ribs 15a or 15b (Fig. 17) described in US Pat. No. 4,956,986, or a special feature related to the applicant's application. It is essentially the same as the hidden rib 7 described in the specification and the drawings attached to Japanese Patent Application No. 4-269215, and connects one wall portion which is present inside the blow-molded body and the other wall portion which faces the wall portion. It is called a hidden rib because its existence cannot be clearly recognized from the outside.

[0009]

【Example】

 1 to 3 show a blow molding apparatus 20 for forming a box-shaped hollow body 10 (see FIG. 3) for a cooler box, and a procedure for blow-molding the box-shaped hollow body 10 using the apparatus 20. It is a thing. The blow molding device 20 is attached to a first die 21 having a core portion 21a, a second die 22 having an inner surface shape surrounding the core portion 21a, and a side portion and a bottom portion of the second die 22. It is provided with slide plates 23 and 24 capable of protruding to the vicinity of the first mold 21. The slide plate 23 is for forming the hidden ribs 11 in the side wall of the box-shaped hollow body 10, and the slide plate 24 is for forming the hidden ribs 12 in the bottom wall. Is movable relative to the second mold 22 between the projecting positions shown in FIG. 2, and the tip thereof constitutes a part of the inner surface shape of the second mold 22 in the retracted position (that is, (It is flush with the inner surface of the mold 22).

The procedure for molding the box-shaped hollow body 10 using the blow molding device 20 is as follows. First, the slide plates 23 and 24 are fixed at the retracted position (if the mold is fixed at the projecting position from the beginning). (When the parison is closed, the parison is caught, which is inconvenient), and both dies 21 and 22 are closed to sandwich the parison 25 as in the ordinary blow molding (see FIG. 1). Next, when the slide plates 23 and 24 are projected to the vicinity of the core portion 21a of the first mold 21, the parison 25 of the portion is projected to the core portion 21a side, and the core portion 21a and the tip of the slide plate 23 or 24 are protruded. The parts sandwiched between are pressed against each other and welded together (see Fig. 2).

Subsequently, almost simultaneously with the supply of the pressurized air into the parison 25, the slide plates 23 and 24 are returned to the retracted position and fixed. At this time, since the tips of the hidden ribs 11 and 12 are welded and integrated inside the facing wall, they remain without being separated, and the outer shape of the parison 25 is maintained by the air pressure filled inside the two molds 21, 22 and the slide plate 23. , 24, and finally, as shown in FIG. 3, a box-shaped hollow body 10 having hidden ribs 11 and 12 in the side wall and the bottom wall is formed.

As far as the box-shaped hollow body 10 thus obtained is viewed from the outside, the presence of the hidden ribs 11 and 12 is not clear even if there are some traces of the slide plates 23 and 24. In the blow molding apparatus 20, since the slide plates 23 and 24 were installed on the second mold 22 corresponding to the outer wall portion 10a of the box-shaped hollow body 10, the structure of the obtained hidden ribs 11 and 12 was as shown in FIG. As shown in, the box-shaped hollow body 10 continuously extends from the outer wall portion 10a toward the facing inner wall portion 10b, and its tip is welded to the inner side of the facing inner wall portion 10b.

In addition, in the above-mentioned embodiment, since the side wall of the container-type hollow article stands substantially vertically, the slide plate is installed on the side of the second mold, but the side wall of the container-type hollow article to be molded is In the case where it is largely inclined outward (for example, in a dish shape), it can be attached to the side of the first mold without any trouble. Further, in the above-mentioned embodiment, the slide plate is used for forming the hidden rib, but one or more slide rods may be arranged and used. In that case, the portion sandwiched between the core portion facing the tip of the slide rod is welded.

[0014]

[Effect of device]

 According to the present invention, a highly rigid container-type hollow article having a hidden rib on the side wall (and also on the bottom wall if necessary) can be manufactured by blow molding.

[Brief description of drawings]

1A is a sectional view of a blow molding apparatus according to the present invention, and FIG. 1B is a sectional view taken along the line AA of FIG. 1A, showing a state before a hidden rib is formed.

FIG. 2A is a sectional view of the blow molding apparatus according to the present invention, and FIG. 2B is a sectional view taken along the line BB of FIG. 2A, showing a hidden rib being formed.

FIG. 3A is a sectional view of the blow molding apparatus according to the present invention, and FIG. 3B is a sectional view taken along line CC of FIG. 3A, showing a state after the hidden ribs are formed.

[Explanation of symbols]

 10 Box-shaped Hollow Body 11, 12 Hidden Rib 21, 22 Blow Molding Die 21a Core Part of Blow Molding Die 23, 24 Slide Plate 25 Parison

Claims (3)

[Scope of utility model registration request] 1. A first mold having a core portion and a second mold having an inner surface shape surrounding the core portion are arranged so as to face each other, and a tip end is an inner surface of the second mold on a side portion of the second mold. A blow molding device, characterized in that a slide plate forming a part of the shape is installed so as to be able to project to the vicinity of the side surface of the core part. 2. A first die having a core portion and a second die having an inner surface shape surrounding the core portion are arranged so as to face each other, and a tip of the first die has a core shape on a side portion of the core portion. A blow molding device, wherein a slide plate forming a part is installed so as to be able to project to the vicinity of the inner surface of the side part of the second mold. 3. The blow molding device according to claim 1, wherein one or more slide rods are installed in place of the slide plate.