JP2000158473A - Integrated foam mold - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent sticking of a foamed resin around an insert without using a seal member, and to reduce manufacturing cost. SOLUTION: An insert accommodating portion 6 for accommodating a part of an insert 2 extended from the inside of a cavity 5 is formed on a mating surface of an upper mold 3 with a lower mold 4, and an insert accommodating portion 6 of the lower mold 4 with the upper mold 3 is formed. A concave portion 10 is formed on the mating surface so as to be aligned with the insert housing portion 6.
Drain to the side. The foamed resin which has flowed out to the insert accommodating portion 6 side has a tapered back surface 1 of the gate 11 due to its own weight.
The burrs 12 flow down to the bottom side of the concave portion 10 along 1a and remain as burrs 12. As a result, the foamed resin sticks around the insert 2. Further, the burr 12 can be easily separated from the product part 1 by pulling by hand after the mold is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated foam molding die for integrally molding a part of an insert into a product part.

[0002]

2. Description of the Related Art For example, as shown in FIG. 3, a seat pad for an automobile as a foam molded body generally has a pad body 1 as shown in FIG.
Hooks (inserts) for attachment to the body at the periphery of
2 are provided integrally.

Conventionally, in order to manufacture a seat pad having such hooks 2 integrally, as shown in FIG. 4, a molding die composed of an upper die 3 and a lower die 4 is used.
An insert receiving portion 6 communicating with the cavity 5 is formed on the mating surface of the lower die 4 and a part of the hook 2 supported by the upper die 3 with a clip or the like is extended into the insert receiving portion 6. A space between the insert accommodating portion 6 and the cavity 5 is sealed by a sealing member 7 formed by winding a slab around the hook 2 in advance, and a foamed resin material is foamed in the cavity 5 to form a pad body 1 as a product portion. The remaining portion of the hook 2 is integrally molded. The insert accommodating portion 6 may be formed in the lower die 4 instead of the upper die 3, or may be formed in common with a joint portion of the upper die 3 and the lower die 4.

[0004]

However, according to the above-mentioned conventional molding method, the seal member 7 must be formed by winding a slab around the hook 2 in advance. In addition, since the sealing member 7 remains in the product part 1 as it is and becomes a consumable, there is a problem that the material cost increases and the cost burden is large.

There is a concept that the insert housing portion 6 is formed shallowly to reduce the clearance between the upper and lower dies 3 and 4 and the hook 5, thereby omitting the use of the seal member 7. However, since there is usually a tolerance of straightness of about ± 1 mm, there is a limit in narrowing the clearance, and when molded without a sealing member, leakage of the foamed resin from the cavity 5 is unavoidable, and the hook 5 The foamed resin sticks around the, and it is necessary to perform deburring after demolding.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to prevent foam resin from sticking around an insert without using a sealing member. Accordingly, it is an object of the present invention to provide an integrated foaming mold that greatly contributes to a reduction in manufacturing cost.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides an insert receiving part formed in a joining part of an upper die and a lower die, in which a part of an insert extending from the cavity is accommodated. In the integral foaming mold for integrally molding the remaining part of the product part with the product part, a recess is formed in the lower mold so as to be aligned with the insert accommodating portion, and the excess portion of the foamed resin is allowed to escape into the recess. I do.

In the integrated foaming mold having the above-described structure, the excess amount of the foamed resin flowing out of the cavity to the insert accommodating portion escapes into the recess of the lower mold by its own weight, and the foamed resin adheres to the insert. Will not be. In addition, since the foamed resin that escapes into the recess remains as a mass of burrs, it is easy to remove burrs after removing the mold.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an integral foaming mold according to one embodiment of the present invention. The integrated foam molding die is used for integral foam molding of the seat pad shown in FIG. 3 described above, and its entire structure is the same as that shown in FIG. 4 described above. The same reference numerals are given to the portions, and the overlapping description will be omitted.
In the present embodiment, a concave portion 10 is formed on the mating surface of the lower die 4 and the upper die 3 so as to be aligned with the insert accommodating portion 6. The concave portion 10 is formed to be considerably deeper than the insert accommodating portion 6 and is arranged close to the cavity 5 via a gate 11 having a small width (thin wall). The gate 11 is provided with a parting line P.D. The height of the top is set so as to be slightly lower than L, whereby the gate 11 and the upper die 3 are set.
A gap δ sufficiently larger than the straightness tolerance ± 1 mm of the hook 2 in the mold closed state is formed between the hook 2 and the hook (insert) 2 supported by the hook. The back surface 11a of the gate 11 on the concave portion 10 side has a predetermined angle α.
It is inclined upward.

In order to carry out foam molding using the above-described mold, the hook 2 is attached to the upper mold 3 using a clip or the like in a state where the mold is opened, while the cavity 5 is formed in the lower mold 4. A release agent is applied to the back surface 11a of the gate 11 including the surface. Then, a predetermined amount of a foamed resin material (foamed beads) such as polyurethane containing a foaming agent is put into the lower mold 4 and the mold is closed, followed by heating and foaming. Then, after the foamed resin fills the inside of the cavity 5, the surplus portion flows out to the insert accommodating portion 6 side through the gap between the gate 11 and the hook 2 and the gap between the upper mold 3 and the hook 2.

The foamed resin that has flowed out to the insert accommodating portion 6 flows down (escapes) into the concave portion 10 of the lower mold 3 along the back surface 11a of the gate 11 by its own weight, and gradually accumulates at the bottom side of the concave portion 10. . That is, the foamed resin hardly adheres to the tip of the hook 2 housed in the insert housing 6, and the tip of the hook 2 maintains the bare skin state. Since the gas generated by foaming accumulates in the space formed by the insert accommodating portion 6 and the concave portion 10, the foamed resin flowing out to the insert accommodating portion 6 side also receives this gas pressure and quickly forms the concave portion 10. It flows down to the bottom side, whereby the adhesion of the foamed resin to the tip of the hook 2 is more reliably prevented.

When the foaming is completed, the foamed resin that has flowed into the concave portion 10 remains in the product portion (pad body) 1 in the cavity 5 as a massive burr 12.
Is released from the lower mold 4 integrally with the product part 1 in accordance with the mold opening. At this time, a release agent is applied to the back surface 11a of the gate 11 in advance, and since the back surface 11a is inclined upward, the burr 12 is released from the lower mold 4 smoothly. Then, as shown in FIG. 2, when the burrs 12 are grasped by hand and pulled after the mold release, the connection of the burrs 12 to the product portion 1 may be thin, and the burrs 12 may be easily manufactured. The hook 1 is detached from the part 1 and is attached to the body by this.
2 is completed (FIG. 3). The height of the top end of the gate 11 is set to an appropriate height in consideration of the surplus amount of the foamed resin, the separability of the burr 12 from the product part 1, and the like.

[0014]

As described above, according to the integrated foaming mold of the present invention, the sealing member can be formed because the foamed resin can be prevented from sticking around the insert without using a special sealing member. Not only the extra work can be omitted, but also the extra material cost can be saved, and the burrs can be clumped and the deburring can be simplified, so that the production cost can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a main part of an integral foaming mold as one embodiment of the present invention and a usage mode thereof.

FIG. 2 is a schematic view showing an embodiment of deburring from a molded article formed by integral foam molding with the present molding die.

FIG. 3 is a perspective view showing the appearance of a seat pad as a foam molded article having an insert integrally.

FIG. 4 is a cross-sectional view showing a main part structure of a conventional integral foam molding die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Product part (pad main body) 2 Hook (insert) 3 Upper mold 4 Lower mold 5 Cavity 6 Insert accommodating part 10 Depression provided in lower mold 11 Gate 12 Burr

Claims (1)

[Claims] 1. An integrated foaming mold for accommodating a part of an insert extending from a cavity in an insert accommodating portion formed at a joining portion of an upper mold and a lower mold, and integrally molding the remaining part of the insert into a product part. 3. The integrated foam molding die according to claim 1, wherein a concave portion is formed in the lower die so as to be aligned with the insert accommodating portion, and an excess amount of the foamed resin is released into the concave portion.