JPS60105506A - Preparation of integrally blow-molded piece - Google Patents

Abstract

PURPOSE:To prepare voidfree pad material by a method wherein resin flow in a blow mold is adjusted by a baffle plate with notches and the corner sides of a mold corner member to prevent the resin from stagnating. CONSTITUTION:The baffle plate 5 with notches 5a..., 5b..., etc. is inserted previously into the conver member 1. Foam material is injected gradually into the cover member 1 and expanded. Then, the flow of the foam material is moved forcibly by the baffle plate 5 with notches toward the corner part 3a of the rise part. Stagnant expanded gas is extruded by this forced adjustment in order not to produce voids 4'. In this manner, the pad material 4 free from defects such as voids etc. can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method of manufacturing an integrally foamed molded product, in which a butt part is integrally foam-molded with a foam material inside a cover member such as a headrest.

BACKGROUND ART Conventionally, when manufacturing headrests, etc., for example,
The headrest cover is blow molded from the parison, and during the blow molding, the upper end of the shaft of the stay is inserted into the parison in advance, and after the blow molding, the butt part is formed by foam hardening of the foam material that is filled into the headrest cover. By fixing the upper end of the shaft of the stay with the butt part, the headrest cover and the butt part are integrated to form a headrest with the stay protruding. However,
In the headrest, when the foam material expands in volume through foaming, it is pushed in near the corners of the cover, causing the air that existed inside the cover and the foaming gas that was not captured by the foam material during foaming to stagnate. This causes the foam material to harden, creating a hollow part where there is no butt part.Also, if holes are made using a needle at each corner of the cover to exhaust gas, the foam material such as urethane foam may become a chain. It tends to seep through the pores and stain the epidermis, which can seriously impair the product's value.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a method for producing an integrally foamed molded article that can be foam-molded without producing the above-mentioned hollow portions.

That is, in the method for manufacturing an integrally foamed molded product according to the present invention, a baffle plate having a cut groove on the plate surface is supported by an axial member such as a stay, and the baffle plate is used to form a cover part with a mold after molding the cover part. By moving and guiding the resin flow of the foam material foaming within the member to the corner portion of the cover member, it is ensured that the foam hardened layer of the foam material can be integrally molded even at the corner portion.

Examples Below, a detailed description will be given with reference to the drawings.
It is as follows.

In the illustrated embodiment, a substantially horseshoe-shaped headrest having a cavity in the center is manufactured as an integrally foamed product. In this headrest, a gap 4' where the butt part 4 does not exist is likely to be formed at a corner 3a near the rectangular end face of the upright part 3 where the stay 2 protrudes from the cover member l. 3, a rectangular baffle plate 5 corresponding to the cross-sectional shape is arranged on the axis of the stay 2, and the baffle plate 5 forcibly guides the foaming flow of the foam material toward the corner as described later. This prevents the formation of voids 4' (see FIG. 1.2). A hard or semi-hard resin plate, metal plate, etc. can be used as the baffle plate 5, and grooves 5a, 5b, etc. are provided on the front and back surfaces as well as the peripheral side. (See Figure 3a).

Also, as this baffle plate 5, one having a step 5c on the side surface can be used (see Fig. 3), and one having a width of about O to ioam narrower than the planar area of the rising portion 3, or one having approximately the same area. may also be used.

Blow molding can be applied to mold the headrest. The blow molding mold 6 is divided into left and right molds e.
a, 8b, and a base 8c on which the split molds 8a, 6b are placed facing each other. The base 6c is provided with a valve 7a discharging compressed air in the center, and brackets 7b and 7c for mounting the stays 2 integrated with the headrest frame 2a are provided on the left and right sides of the valve 7a (4th version 1). (suspension)
.

Using this mold 6, firstly, the stay 2 bearing the baffle plate 5 on its axis is vertically supported by the brackets 7b and 7C, and then the parison forming the cover member 1 is moved from the goose head to the lower end side. It is extruded into an open cylindrical shape and placed on the base 6C so that the headrest frame 2a and the stay 2 are received inside it. Thereafter, the parison is clamped and fixed between the split molds 8a and Bb. During this mold clamping, in order to avoid damage due to the parison being pulled and coming into contact with the baffle plate 5, the baffle plate 5 is slid back and moved along the axis -1- of the stay 2 so that it is located at a wide part of the parison. I can do it. The retreat movement is slide bin 7
d, use 7e to reach near the headrest frame 2a.
It is only necessary to support the parison until it is blow-molded. After the mold 6 is clamped and fixed, compressed air is supplied into the parison from the valve 7a of the base 6C to form the cover member 1 having a desired 1R shape. Thereafter, the force formed into the <r body shape/<1 member l is removed from the mold 6, and the inside is filled with the foam material 8.

When filled with the foam material 8, the cover member 1 is inverted so that the stay 2 protrudes upward, and the foam material 8 is retained inside the top of the cover member 1 (see Fig. 5). Foam material 8. Along with this foaming,
The foam material 8 gradually increases in volume and rises, and the baffle plate 5
When the baffle plate 5 is raised to a retracted position, it is pushed up and the resin flows from the cut grooves 5a formed on the back surface of the baffle plate 5 to the cut grooves 5b formed on the circumferential side.・It moves upwardly while being guided by the cut grooves 5a... drilled on the surface of the baffle plate 5, and rapidly moves in the direction of the corner portion 3a within the space between it and the bottom portion 3b of the rising portion 3. (See Figure 6a). In addition, in the baffle plate 5 provided with the step 5C, a large amount of foamed resin accumulates at the step 5C and fills the corner portion 3a (see Fig. 6). The gas can be discharged from a gas vent hole 3C formed in the gas vent hole 3B, and the gas vent hole 3C may be formed by integrally molding a gas vent pipe during blow molding, or may be simply formed by perforating or the like.

In the above-described embodiment, the baffle plate 5 is inserted in advance when the cover member 1 is molded, but it may be attached to the shaft line member such as the stay 2 after the cover member 1 is molded. Further, although this embodiment shows a headrest having rising portions 3 corresponding to the left and right stays, the present invention can also be applied to the molding of a headrest having a generally trapezoidal shape on the right side. In that case, one baffle plate is installed between each stay, and the foaming flow of the foam material can be moved and guided to each corner of the square. Furthermore, it can be applied not only to the production of headrests but also to the production of various foam molded products, and the members on which the baffle plate 5 is attached and arranged include not only those protruding from the cover member l such as stays, but also foam. 1 for wood! It is also possible to use a frame with P-included layout/l.

In this way, the foaming flow of the foam material is forced through the cut grooves 5a..., 5b... of the baffle plate 5 into the rising portion 3.
If the foaming gas is moved in the direction of the corner, the foaming gas that tends to stay therein can be suppressed and moved and discharged from an appropriate gas venting point, so that it is possible to form a butt part 4 without a defective part. In addition, the baffle plate 5 allows the foam material to remain in the cut groove thereof, and can finally be cured integrally with the butt portion.

Effects of the Invention According to the method for manufacturing an integrally foamed molded product according to the present invention, the foamed flow of the foam material is rapidly raised through the grooves formed in the baffle plate and guided to move to the sandwiched portion, thereby preventing the foaming flow from stagnation. The foam material can be filled even in the corners by forcibly pressing the easily foaming gas, which prevents damage to the butt part.Furthermore, when manufacturing products such as headrests, the baffle plate can be used as a support plate for stays, etc. The support shaft member can be firmly fixed integrally with the butt part.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a headrest as an example of the integrally foamed molded product manufactured by the present invention, Fig. 2 is an explanatory view showing problems in manufacturing the same headrest, and Fig. 3a is used in the method according to the present invention. FIG. 3 is a perspective view of one embodiment of the baffle plate; FIG. 4 is an explanatory view of a mold used in the same method; FIG. 4 is an explanatory diagram of a mold used in the same method; FIGS. 5 and 6 a and b are partially enlarged side views showing the foaming flow of the foam material. Work: Cover part, 2 Axis member such as Nisty, 3a: Corner part, 5: Baffle plate, 5a, 5b: Cut groove, 6: Mold, 8
: Foam material.

Claims (2)

[Claims] (1) 10 boards! A baffle plate with a /J groove of 4=j is supported by an axis member such as a stay that is inserted into the cover member to be molded, and the cut groove of the baffle plate is used to insert the cover member into the cover member after molding the cover member. A method for manufacturing an integrally foamed molded product, characterized in that a resin flow of a foam material foamed within the member is moved and guided to a corner portion of a cover member. (2) The method for manufacturing an integrally foamed molded product according to claim 1, wherein the baffle plate is slidably and loosely supported on the axis of the stay or the like.