JPH0370612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing an integrally foamed molded product, which is applied to, for example, integrally foam-molding a pad portion with a foam material inside a cover member forming a headrest. It is something.

Conventionally, when manufacturing a head rest, for example, a head rest cover is blow molded from a parison, and during the blow molding, the upper end of the shaft of the head rest stay is housed in the parison in advance to form the head rest cover. Blow molding is performed, and after this molding, the foam material filled in the cover is foamed and hardened to form a pad part, and the pad part is further fixed to the upper end of the shaft of the headrest stay to connect the headrest cover and the pad part. Formation as an integrated headrest has been practiced.

However, in the manufacturing process of this headrest, as the volume of the foam material increases due to foaming, the air that existed inside the cover and the foaming gas that was not captured by the foam material during foaming are absorbed into the corners of the headrest cover. If the pad portion hardens while being pushed into the pad, a hollow portion where the pad portion does not exist is likely to be formed inside. If holes are made using a needle at each corner of the headrest cover in order to exhaust the air and gas, the foam material such as foamed urethane will seep out from the holes and cover the surface of the headrest cover. This can easily lead to situations such as staining, which can significantly reduce the product value.

In order to solve this problem, the applicant of the present application has manufactured a headrest by inserting a headrest stay in advance inside a parison that is molded as a headrest cover. A baffle plate formed of a plate is fixedly attached, and this baffle plate is connected to a head rest cover that is blow-molded from a parison, so that the baffle plate is located inside a bag-shaped rising part near the corner of the rising part. We previously proposed that the flow of resin accompanying the foaming of the foam material be forcibly moved to the corners of the bag to prevent cavities from forming in the pad.
No. 249061).

However, in this headrest manufacturing method, when a parison with a baffle plate placed inside is held between a mold with a parting line near the corner of the rising part formed in the bag shape of the headrest cover, this parison is As it is clamped in the mold, it is strongly pulled and comes into contact with the baffle plate, which may cause it to be scratched and torn by the corner edges of the baffle plate.

Problems to be Solved by the Invention The present invention has an object to prevent the parison formed as a cover member of an integrally foamed molded product from being damaged by baffle plates, and to form a parison in which the resin flow accompanying the foaming of the foam material continues to the cover member. An object of the present invention is to provide a method for manufacturing an integrally foamed molded article, which is devised so that the foam material can be moved and guided to the corner portion of the bag portion to be filled and foamed into the corner portion of the bag portion.

Means for Solving the Problems In the method for manufacturing an integrally foamed molded product according to the present invention, a cover member having a hollow three-dimensional bag portion is blow-molded from a parison using a mold, and then a foam material is placed inside the cover member. When integrally foam-molding the pad part into the entire interior of the cover member including the bag part by filling it with A baffle plate fixed in advance on the axis of an axial member such as a stay is housed inside a parison that forms a cover member together with the axial member, and the baffle plate accommodation area of this parison is set in a space relatively wider than the baffle plate. A parison is placed in the cavity space of the mold at a position corresponding to the cavity formed by the mold, and the parison to be clamped by the mold is blow-formed and then removed from the mold to obtain the cover member. The foam material is filled inside the obtained cover member and foamed, and the resin flow accompanying the foaming is applied to the corner of the bag portion formed in the cover member through the gap between the inner surface of the cover member and the end face of the baffle plate. The pad portion is foam-molded integrally with the cover member by forcibly guiding the movement.

Function: In this method of manufacturing an integrally foamed molded product, the baffle plate storage area of the parison is positioned corresponding to the cavity formed in a space relatively wider than the baffle plate, and the parison is clamped with a mold. It is possible to avoid damage to the parison by the baffle plate, form a cover member in which the baffle plate is housed inside near the corner of the bag part, and also use the baffle plate to prevent resin flow caused by foaming of the foam material into the bag part. Since the bags are forcibly moved and guided to the corners of the bags, it is also possible to prevent cavities from forming at the corners of the bag parts, making it possible to form an integrally foamed molded product with good marketability.

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

In the illustrated embodiment, as an example of an integrally foamed molded product,
A case is shown in which a substantially horseshoe-shaped headrest having a cavity in the central portion is manufactured. In this headrest, as shown in FIGS. 1 and 2, a substantially rectangular rising portion 3 that protrudes outward from the cover member 1 along the axis line of the headrest stay 2 is formed as a bag portion. A gap 4' where the pad part 4 does not exist is likely to be formed in the corner part 3a near the end face of the part 3. Therefore, a baffle plate 5 having a plate surface substantially corresponding to the cross-sectional shape of the riser 3 is fixedly mounted on the axis of the headrest stay 2 inserted in advance inside the riser 3, and this baffle plate 5 As will be described later, by forcibly moving and guiding the resin flow accompanying the foaming of the foam material to the corner portions of the rising portion 3, void portions 4' are prevented from forming at those portions.

A hard or semi-hard resin plate or a metal plate can be used as the baffle plate 5, or a porous plate material that can be impregnated with a foam material and finally hardened integrally with the pad part. May be used. This baffle plate 5 has a plate surface that is about 3 to 10 mm narrower than the cross-sectional shape of the rising portion 3 of the headrest.

In manufacturing the headrest, first, the cover member 1 is formed from a parison by using a blow molding mold 6 as shown in FIG. This mold 6 for blow molding includes left and right split molds 6a, 6b, and a base 6c on which the various molds 6a, 6b are placed facing each other. The lower ends 6d and 6e of each of the split molds 6a and 6b are mold surfaces that form a parting line on the rising portion 3 formed as a bag portion of the cover member 1, and these mold surfaces are provided so that they are opposite to each other. The cavity space is provided so that when the opening 6f is opened, the end face of the rising portion 3 having a relatively large opening 6f is not completely closed off, and a wide cavity portion is formed. Further, the base 6c is provided with a valve 7a in the center for discharging compressed air, and on the left and right sides thereof are brackets 7 that stand and support the headrest stay 2 which is integrated with the headrest frame 2a.
b, 7c are provided. This bracket 7
The headrest stay 2, which is vertically supported at b and 7c, has a narrow space between it and the inner side of the end surface forming the bottom 3b of the rising portion 3 by passing the axis of the headrest stay 2 through the plate surface. A baffle plate 5 housed inside the cover member 1 so as to be positioned is fixedly attached in advance on the axis.

Using the mold 6, the headrest stay 2 with the baffle plate 5 mounted on the axis is moved to the bracket 7.
b and 7c, and then extrude the parison forming the cover member 1 from the die head into a cylindrical shape with the lower end open. Inside this parison, a headrest frame 2a and a headrest stay 2 are placed.
is received and placed on the base 6c. Thereafter, the mold 6 is clamped and fixed so that the parison is sandwiched between the split molds 6a and 6b. Along with this mold clamping, the split mold 6 is made so that the lower end side of the parison becomes the rising part 3 of the cover member 1 that protrudes the headrest stay 2 to the outside.
A tensile force is applied to the parison from the point where it is held between the lower ends 6d and 6e of a and 6b. At that time, the lower end 6 which is the forming surface of the parting line
Since the openings 6f and d are open from the wide cavity portion, the tension of the parison can be relaxed as shown in FIG. 4, and the parison can be prevented from coming into contact with the baffle plate 5.

After the mold 6 is clamped and fixed, the parison can be formed into the cover member 1 having a desired three-dimensional shape by supplying compressed air into the inside of the parison from the valve 7a of the base 6c. Thereafter, the cover member 1 formed into a three-dimensional shape is removed from the mold 6, and the inside is filled with a foam material 8. When the foam material 8 is filled, the cover member 1 is inverted so that the headrest stay 2 protrudes upward as shown in FIG.
It stays inside the top of the bottle and foams. Along with the foaming, the foam material 8 rises while gradually increasing its volume. When this foam material 8 reaches the vicinity of the mounting position of the baffle plate 5, it bypasses the baffle plate 5.
It rapidly moves from the gap between the inner surface of the rising portion 3 and the end surface of the baffle plate 5 toward the corner of the rising portion 3. Along with this movement, the foaming gas is discharged outside through the gap between the baffle plate 5 and the inner surface of the rising portion 3 through the large hole in the cover member 1 through which the headrest stay 2 formed by the hole 6f is inserted. You can do it like this. After the pad portion 4 is integrally molded inside the opening of the cover member 1 using a foam material 8, a cap 9 is fitted into the opening of the cover member 1 and fixed with a tassel 10 as shown in FIG. It can be blocked by this.

In this way, if the foaming flow of the foam material is forcibly moved toward the corner of the rising portion 3 along the baffle plate 5, the pad portion 4 can be formed without any defects due to voids at the corner of the rising portion 3. It is also possible to integrally foam-mold the foam gas, and it is also possible to move the foaming gas that tends to stagnate under pressure and discharge it from an appropriate gas release point.

In addition, in the above-mentioned embodiment, a head rest having rising portions 3 corresponding to the left and right head rest stays is shown, but a head rest having a general trapezoidal shape can be formed using a cover member whose entire shape is formed into a bag shape. It can also be applied sometimes. In this case, by mounting one baffle plate across each head rest stay, it is possible to move and guide the resin flow accompanying the foaming of the foam material to each corner portion forming the square portion. Further, the present invention can be applied not only to the production of headrests but also to the production of various foam molded products. Furthermore,
The member for fixing the baffle plate 5 is not limited to a member protruding from the cover member 1 such as a headrest stay, but may also be a frame embedded in the foam material inside the cover member.

Effects of the Invention According to the method for manufacturing an integrally foamed molded product according to the present invention, when mold-clamping the parison, the accommodation portion of the baffle plate is positioned corresponding to the cavity portion which is wider than the baffle plate, and the parison is molded with a mold. Since the cover member formed from the parison is tightened, the cover member formed from the parison is prevented from being damaged by the baffle plate, and the resin flow is forcibly moved and guided by the baffle plate, which is housed in advance inside the cover member, to prevent the bag from being damaged. It is now possible to integrally mold a pad portion with no voids even in the corner portions of the shape of the cover member.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a headrest as an example of an integrally foamed molded product manufactured by the present invention, Fig. 2 is an explanatory view showing problems in the process of manufacturing the headrest, and Fig. 3 is a perspective view showing a headrest as an example of the integrally foamed molded product manufactured by the present invention. An explanatory view of the mold used, Fig. 4 is a partially enlarged side cross-sectional view showing a state in which the parison is clamped by the same mold, and Fig. 5 is an explanatory view of the state in which the cover member is filled with foam material after molding. , FIG. 6 is a partially enlarged side view showing resin flow accompanying foaming of the foam material. 1: Cover member, 2: Axis member such as head rest stay, 3: Bag portion, 3a: Corner portion of bag portion, 5:
Baffle plate, 6: Mold, 8: Foam material.

Claims (1)

[Claims] 1 After blow-molding a cover member having a hollow three-dimensional bag portion from a parison using a mold, the inside of the cover member is filled with foam material, and the pad portion is integrally foamed inside the entire cover member including the bag portion. In the method of manufacturing an integrally foamed molded product, a cover member is provided with a baffle plate that is positioned near a corner corresponding to the corner of the bag portion and is fixedly attached in advance on the axis of an axial member such as a head rest stay, together with the axial member. The parison is placed in the cavity space of the mold, with the baffle plate storage area of the parison corresponding to a cavity formed in a space relatively wider than the baffle plate. , the parison to be clamped with the mold is blow-molded and then removed from the mold to obtain a cover member;
The inside of the obtained cover member is filled with a foam material and foamed, and the resin flow accompanying the foaming is directed from the corner of the bag portion formed in the cover member through the gap between the inner surface of the cover member and the end face of the baffle plate. 1. A method for manufacturing an integrally foamed molded product, characterized in that the pad portion is foam-molded integrally with the cover member by forcibly guiding its movement.