JPH0336010B2 - - Google Patents

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 pad portion is integrally foam-molded with a foam material inside a cover member such as a headrest.

BACKGROUND ART Conventionally, for example, when manufacturing a head rest, etc., a head rest cover is blow molded from a parison, and during the blow molding, the upper end of the shaft of a stay is inserted into the parison in advance, and the head rest cover is inserted into the parison after the blow molding. The head rest cover and the pad part are integrated by molding the pad part by foaming and hardening the foam material filled in the rest cover, and by fixing the pad part to the upper end of the shaft of the stay, the head rest cover and the pad part are integrated to form a head rest with the stay protruding. things are being done.
However, in this headrest, when the foam material expands in volume by foaming, the air that was pushed into the cover by foaming near the corners of the cover and the foaming gas that was not captured by the foam material during foaming are removed. This caused the foam to stagnate and harden, creating a hollow part where no patch existed.In addition, multiple holes were manually punched using a needle in each corner of the cover, and as the foam foamed, the stagnation formed in the holes. Although pretreatment is performed to discharge air and foaming gas that was not captured during foaming, not only the gas but also foam materials such as urethane foam leak through the holes and cause problems such as staining the skin. This can easily lead to a situation where the product value is significantly impaired.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a method for manufacturing an integrally foamed molded product 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 substantially square or square shape in longitudinal section is supported by an axial member such as a stay inserted into a cover member to be molded, and the cover member is By moving and guiding the resin flow of the foam material foaming inside the cover member after molding to the space between the side surface of the baffle plate and the corner side surface of the cover member, the foam material is reliably foamed and hardened at the corner portion. The layers can be filled and molded.

Embodiments Hereinafter, a detailed description will be given with reference to the drawings.

In the illustrated embodiment, a case is shown in which a substantially horseshoe-shaped headrest having a cavity in the center is manufactured as an integrally foamed molded product. In this headrest, a corner portion 3 near a rectangular end surface of a rising portion 3 that projects a stay 2 from a cover member 1 is provided.
Since a gap 4' where no part 4 is present is likely to occur at point a, a rectangular baffle plate 5 corresponding to the cross-sectional shape is installed on the axis of the stay 2 at the rising section 3.
As will be described later, the baffle plate 5 forcibly moves and guides the foaming flow of the foam material in the direction of the corner portion, thereby preventing the formation of a void portion 4' (see FIGS. 1 and 2). The baffle plate 5 is made of hard metal.
A semi-rigid resin plate, metal plate, metal plate, etc., formed into a substantially square or square shape in vertical section is used, and a plate whose width is about 3 to 10 mm narrower than the planar area of the rising part 3 can be used ( (See Figure 3). Blow molding can be applied to mold the headrest. The blow molding die 6 has split molds 6a and 6b on the left and right sides, and a base 6c on which the split molds 6a and 6b are placed facing each other. Base 6
Brackets 7b and 7c have a valve 7a in the center for discharging compressed air, and brackets 7b and 7c have stays 2 integrated with the head rest frame 2a placed on the left and right sides of the valve 7a.
Further, slide pins 7d and 7e are provided to push up the baffle plate 5 which is loosely fitted and supported on the axis of the stay 2.
is installed (see Figure 4).

Using this mold 6, the stay 2 is first supported by the brackets 7b and 7c, and the baffle plate 5, which is loosely fitted and supported in advance on each axis of the stay 2, is placed on the slide pin 7d,
7e to push it up close to the head rest frame 2a. Next, the parison forming the cover member 1 is extruded from the die head into a cylindrical shape with its lower end open, and placed on the base 6c so that the headrest frame 2a and the stay 2 are received inside the parison. After that, the parison is clamped and fixed between the split molds 6a and 6b, but at this time, the lower end side of the parison becomes the rising part 3 from which the stay 2 of the headrest protrudes, and the lower end side of the split molds 6a and 6b When forming a parting line, the baffle plate 5 is kept supported upward by the slide pins 7d and 7e in order to separate the baffle plate 5 from the parting line.
If the split molds 6a and 6b are clamped in this state, even if the parison forming the cover member 1 is displaced due to tension, it will not come into contact with the baffle plate 5 at an acute angle, so damage to the parison can be prevented. 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 three-dimensional shape. Thereafter, the cover member 1 molded into a three-dimensional shape is removed from the mold 6, and the inside is filled with the foam material 8. When the foam material 8 is filled, the cover member 1 is inverted so that the stay 2 protrudes upward, so that the foam material 8 stays inside the top of the cover member 1 (see Fig. 5), and the foam material 8 is 8. Foam. With this foaming, the foam material 8 gradually increases in volume and rises, and the baffle plate 5 located near the headrest frame 2a of the stay 2 is moved along the axis of the stay 2 by the flow of resin flowing into the recess 5a. It is then stably pushed up and moved upward (see Figure 6). The baffle plate 5 that is pushed up further rises inside the rising part 3 of the headrest and stops rising when it comes into contact with the end face forming the corner part 3a, and the foaming flow of the foam material is still increasing in volume. rapidly moves from the recess 5a of the baffle plate 5, bypassing the side wall 5b of the baffle plate 5, and toward the side surface of the corner of the rising portion 3 (see FIG. 7). At that time, the foaming gas can be discharged from a gas vent hole 3c formed at the bottom 3b of the rising portion 3, and the gas vent hole 3c is used as slide bins 7d and 7e.
The gas vent pipe may be integrally formed during blow molding, or it may be formed as a simple hole by perforation or the like later.

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 an axial member such as the stay 2 after the cover member 1 is molded. In addition, in this embodiment, the cover member is pulled by the clamping clamp of the mold and comes into contact with the baffle plate 5, and there is a risk that the cover member may be scratched and torn by the corner edges of the baffle plate, so the baffle plate 5 is The mold was clamped while being supported upward by a slide pin to keep it away from the parting line, but when it is made of an elastic material such as rubber, the baffle plate becomes curved and deformed due to pressure from the surroundings when clamping the mold. Since the corner edges do not come into contact with the cover member, it is possible to avoid the trouble of clamping the mold while supporting the baffle plate upward with a slide pin in order to prevent the above-mentioned damage. In addition, when using a stay with a baffle plate fixed in advance at a desired position, the stay 2 should be attached to the brackets 7b and 7c by 10 to 40 mm.
It is sufficient to attach the stay to a high degree and perform blow molding in the same manner, and then slide the cover by the amount that is raised when the stay is previously attached to the blow skin of the completed core bar. Further, in this embodiment, a head rest having rising portions 3 corresponding to the left and right stays is shown, but the present invention can also be applied to the molding of a head rest having a general trapezoidal shape. In that case, one baffle plate can be installed between each stay to guide the foaming flow of the foam material 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 are not limited to those protruding from the cover member 1 such as stays, but also foams. It can also be used as a frame embedded in a material.

In this way, if the foaming flow of the foam material is forcibly moved toward the corner of the rising portion 3 using the baffle plate 5, the gas or foaming gas that has accumulated in advance can be easily pressed and moved, allowing appropriate degassing. Since it can be discharged from a specific location, it is possible to form a pad portion 4 without any defective portions. In addition, the baffle plate 5 allows the foam material to stay in its recess and finally hardens integrally with the pad portion.

Effects of the Invention According to the method for manufacturing an integrally foamed molded product according to the present invention, the foam flow of the foam material flows into the recess and bypasses the side wall of the baffle plate, thereby forming a connection between the side wall and the side surface of the corner portion. Since the foaming gas, which tends to move and stay in the gap, can be forcibly pressed and the corner parts can be filled with foam material, there is no damage to the parts, and it is also suitable for manufacturing products such as headrests. It is also possible to use the baffle plate as a support plate to firmly and integrally fix a support shaft member such as a stay to the 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 headrest, and Fig. 3
The figure is an explanatory diagram showing the mounting state of the baffle plate used in the method according to the present invention, Figure 4 is an explanatory diagram of the mold used in the same method, and Figure 5 is an explanatory diagram showing the state in which the cover member is filled with the foam material after molding. The state explanatory diagrams, FIGS. 6 and 7, are partially enlarged side views showing the foaming flow of the foam material shown in FIG. 5. 1: Cover member, 2: Axis member such as stay, 3
a: Corner, 5: Baffle plate, 6: Mold, 8: Foam material.

Claims (1)

[Scope of Claims] 1. A baffle plate having a substantially square-shaped or square-shaped vertical section is supported by an axial member such as a stay inserted into a cover member to be molded, and after the cover member is molded with a mold, the baffle plate is A method for manufacturing an integrally foamed molded product, characterized in that the resin flow of the foamed foam material is moved and guided within the gap between the side surface of the baffle plate and the corner side surface of the 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, etc.