JPH08132453A - Mold for molding headrest substrate - Google Patents

Abstract

PURPOSE: To provide a mold for molding a headrest substrate related to an assembling type headrest simplifying the transport route of a stay and eliminat ing the poor appearance of the packing style to reduce the delivery cost of the headrest or capable of molding a thick-walled headrest substrate within a short time without providing a steam assist though foam beads are used as a raw material. CONSTITUTION: A mold for molding a headrest substrate made of a foamed resin supported through a stay is equipped with a cavity mold 3 having a cavity formed thereto so as to follow the outer shape of the headrest substrate and a core mold 4 provided with the projection 7 suspended to the center part of the cavity at the time of mold clamping and the projection 7 is used in order to form the receiving space in which the stay can be inserted to the headrest substrate and has an almost flat shape and, further, the venting hole 75 capable of blowing steam into the cavity C is formed to the surface of the projection 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a foamed resin headrest base body which is a main body of a headrest attached to the upper end of a seat back of a vehicle or the like.

[0002]

2. Description of the Related Art A foldable or fixed headrest is attached to the upper end of a seat back of an automobile or the like so as to protect the head of an occupant and provide comfort. Such a headrest is made by arranging the base of the stay in the pillow-shaped sewn surface material, setting it in the foaming mold, and pouring the foaming raw material from the injection port provided in the surface material to foam and cure it. Integrated headrest base, skin material, and stay,
There is a product in which only the base of the stay is set in the foam molding die, the foaming raw material is poured, the foam is cured and taken out, and the integrally molded product of the stay and headrest base is covered with a skin material such as a fabric in a later step. Was.

[0003]

However, each of the above-mentioned conventional headrests has the following problems. The method of transporting the headrest depends on the plastic cardboard packaging (Fig. 11) and the trolley packaging (Fig. 12), but since the stay 2 is already integrally fixed to the headrest base 1 during transportation, The appearance deteriorated and the transportation efficiency did not increase. In addition, the stay 2 is carried in from the stay maker to the foam molding maker, and the stay molding 2 is integrated with the headrest base body 1 at the foam molding maker, and the finished product is further delivered to the assembly maker and assembled on the seat back. However, in the foam molding manufacturer, the stay 2 was only integrated with the headrest base body 1 and did not create new value. On the contrary, since the delivery flow of the stay 2 takes a detour, the distribution cost of the product is high.

On the other hand, in general, the required molding time greatly differs depending on the thickness of the foam-molded article made of expandable resin beads (hereinafter simply referred to as foam beads). FIG.
The relationship between the wall thickness of the foamed resin molded product and the molding time is shown in the graph in Fig. 3. As can be seen from the figure, if the wall thickness increases, it takes a long time to heat and cool the foamable resin material. Therefore,
A headrest substrate having a thickness of 120 mm or more took a very long time when the foamed bead molding was used, and the productivity was lowered. In addition, when the wall thickness is 100 mm or more, defective fusion is apt to occur in the central portion, and the product tends to be defective. As such a countermeasure, for example, Japanese Patent Laid-Open No. 1-283130.
Some of the molds shown in Japanese Patent Laid-Open Publication No. 1994-09242 have some thin tubular steam assists that project into the cavity and inject steam for fusion of foam beads into the center of the cavity via the steam assists. . However, when steam assist is provided, the frictional resistance when ejecting a molded product from the cavity increases, cracks and chips are likely to occur in the molded product, and there is an unnecessary hole in the molded product. The adoption of steam assist was not preferable as a mold for molding the headrest base.

The present invention solves the above-mentioned problems, and simplifies the transportation route of stays and eliminates the bad packing of the headrest to reduce physical distribution costs. For the purpose of providing a molding die for a headrest base body, which is capable of forming a thick headrest base body in a short time without using steam assist while using foam beads as a raw material. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION The gist of the first aspect of the present invention is a mold for molding a foam resin headrest base body supported via a stay, in which a recessed portion is formed in accordance with the outer shape of the headrest base body. And a core mold provided with a protrusion that hangs down at the center of the recess when the mold is closed. The protrusion forms a receiving space into which the stay can be inserted in the headrest base. A mold for molding a headrest base body, which has a substantially flat shape and further has a vent hole formed on the surface thereof, through which steam can be blown into the cavity.

A mold for molding a headrest base body according to the second aspect of the present invention is characterized in that the projection according to the first aspect of the present invention is detachably attached to the core mold by a fixing means. The mold for molding a headrest base according to a third aspect of the invention is the first or second aspect of the invention, in which the protrusion is formed into a flat bottomed bag shape, and a constricted portion is provided near the tip of the protrusion. When provided, the stay preventing rib is integrally formed in the receiving space to make it easier to pull out the stay. In the mold for molding the headrest base body of the fourth invention, the constricted portion of the third invention is discontinuously provided. A mold for molding a headrest base according to a fifth aspect of the present invention is the first or second aspect of the invention, in which a pipe having a plurality of vent holes for steam injection is bent into a U-shape, and a flat plate is fixed inside the pipe. By doing so, it is formed into a substantially flat shape. Here, "pipe" refers to a hollow tubular body, and its cross-sectional shape is not limited to a circle.

[0008]

Like the mold for molding the headrest base according to the first aspect of the invention, a substantially flat projection having a vent hole through which steam can be blown is provided, and a receiving space for inserting a stay is formed in the projection. Since the stay is arranged in the substantially central portion of the headrest base body, the maximum thickness of the foam beads that must be fused at the time of molding the headrest base body is half the thickness of the headrest base body. Therefore, even if the thickness of the headrest base body is about 120 mm, there is no fear of defective fusion, and the molding time can be shortened. When the projection is detachably attached to the core mold as in the second aspect of the invention, the replacement of the projection is facilitated and the stay shape can be flexibly changed. When the constricted portions are provided on the protrusions as in the third and fourth inventions, it is difficult to pull out the stays by inserting the stays into the headrest base body, and once they are fitted, the stay preventing ribs form the constricted portions. become. Therefore, the fixation of the stay to the headrest base body is ensured. Further, when the projection as in the fifth invention is formed, the pipe serves as a holding space for accommodating the stay in the headrest base body, and the flat plate serves as a receiving space for inserting the stay into the headrest base body, which is functional. A perfect headrest base is completed.

[0009]

EXAMPLES The present invention will be described in detail below based on examples. (1) Example 1 FIGS. 1 to 7 show an example of a mold for molding a headrest base according to the present invention. FIG. 1 is a perspective view of a headrest base body and a stay according to an embodiment, FIG. 2 is a vertical sectional view in which the headrest base body and the stay are combined, FIG. 3 is a sectional view taken along line IV-IV of FIG. 2, and FIG. Vertical section of the mold,
5 is a perspective view of the protrusion, FIG. 6 is a front view of FIG. 5, and FIG. 7 is a plan view of FIG.

In FIG. 1, a stay 2 is formed by bending a metal pipe into a substantially U-shape and has left and right leg portions 21 and 2.
1 and a connecting portion 22 connecting them. Stay 2
And the headrest base 1 are separately molded, and the connecting portion 22 of the stay 2 is later formed on the bottom surface 1 of the headrest base 1.
The holding spaces 1b, 1 which are inserted into the slit-shaped receiving space 1a opening at d and the stay 2 is located on the outer periphery of the receiving space 1a.
By fitting within c, both are combined as shown in FIGS. 2 and 3. The surface of the headrest base body 1 is covered with a skin material after the headrest base body 1 and the stay 2 are joined,
It will be a headrest product.

The mold for molding the headrest base 1 is a mold for foam molding using foam beads as a raw material, and includes a set of cavity mold 3 and core mold 4 as shown in FIG. . The cavity mold 3 is a headrest base body 1.
It is formed in a pillow-shaped concave / concave modeled after the outer shape of. The cavity mold 3 has a box-shaped frame 51 and bolts 5
Two chambers are fixed, and the chamber 51 is formed by the frame 51 and the cavity mold 3. The chamber chamber 5 is provided with a steam introduction pipe 53, a cooling introduction pipe 54, and a drain discharge pipe (not shown). Reference numeral 31 is a large number of through holes formed in the cavity wall surface of the cavity mold 3, which connects the cavity C and the chamber 5 and serves as an air escape path for filling the foam beads and a steam passage for steam heating. The through holes 31 are sized so that the foam beads a cannot pass through.

The core mold 4 is a convex mold in which a protrusion 7 is provided substantially in the center, and the protrusion 7 hangs down at the center of the concave portion of the cavity mold 3 when the mold is closed. Like the cavity mold 3, the core mold 4 is fixed to the box-shaped frame 61 with bolts 62 so that the frame 61 and the chamber 6
Create Then, in the chamber chamber 6, the steam introducing pipe 6
3, a cooling water introduction pipe 64 and a drain discharge pipe (not shown) are provided.

The projection 7 is for forming a receiving space 1a into which the stay 2 can be inserted in the headrest base 1, and is formed into a flat bottomed bag shape by pressing a stainless steel plate and welding the peripheral edge. The protrusion 7a is formed, and the flange 7b is fixed to the opening edge of the upper surface of the protrusion 7a. The protrusion 7a can be made of an aluminum plate or the like instead of the stainless steel plate. Reference numeral 79 indicates an opening. The bag-like width of the protruding portion 7a is substantially equal to the diameter of the stay 2, and the protruding portion 7a is formed by denting the stainless steel plate near the outer peripheral edge of the protruding portion 7a.
2 is provided. The constricted portions 71, 72 form cylindrical portions 73, 74 having a substantially U-shaped shape having the same cross section as the stay 2 on the outside thereof (FIGS. 5 to 7). Tube 73,
74 serves to create holding spaces 1b and 1c for accommodating the stay 2 in the headrest base 1. The headrest base 1 is provided with the shake-preventing ribs 14 and 15 by continuously providing vertically elongated constricted portions 71 on both sides of the protruding portion 7a. However, the constricted portion 72 disposed near the tip of the protruding portion 7a.
Are discontinuously provided. By providing the constricted portion 72 discontinuously, the rib 1 for preventing the headrest base body 1 from coming off
This is because the division notch 13 is formed in the first and the second portions 12. By providing the dividing notch 13, the slip-off preventing ribs 11 and 12 are provided.
Elastically deforms easily, and the stay 2 is easily inserted into the holding space 1c. The constricted portion 72 is provided on both surfaces of the protrusion 7a, but the slip-off preventing ribs 11 and 12 are on the right side (in FIG. 2).
Has a shape that forms a gentle slope. This is because by forming the gently inclined surface, the slip-out preventing ribs 11 and 12 can be smoothly expanded when the stay 2 is inserted.

A large number of vent holes 75 are formed on the surface of the protrusion 7a, and the protrusion 7a is shaped like a bottomed bag from the chamber chamber 6.
The steam that has entered the (opening 79) can be blown out into the cavity C. The diameter of the vent hole 75 is the same as that of the through hole 31.
Similarly to the above, the structure is such that the diameter of the foam beads is smaller than the diameter of the foam beads and the foam beads a injected from the filling gun 81 into the cavity C cannot pass through. The vent hole 75 in FIGS. 5 and 6 is drawn in a large size for easy understanding. The cavity wall surface of the core mold 4 is also provided with a through hole 41 similar to the cavity mold 3.

Reference numeral 76 indicates a brim that extends over the outer periphery of the protrusion 7a. By providing the collar 76, the auxiliary groove 1 having a constant width is provided on the outer peripheral edge of the holding spaces 1b and 1c of the headrest base 1.
6 and 17 are formed. Stay 2
This is because the receiving space 1a is easily expanded when the head is inserted into the headrest base body 1, and the stay 2 can be accommodated in the holding spaces 1b and 1c with a small force. The brim 76 may be omitted if the headrest base 1 is highly flexible (deformable).

The flange 7b is provided with a hole 77 for fixing to the core mold 4. The protrusion 7 is fitted into the opening 42 located at the center of the core mold 4, and the protrusion 7 is inserted into the hole 77.
The bolt 78 is fixed to the core mold 4 by utilizing. Although the bolts 78 are used as the fixing means in the present embodiment, any fixing means may be used as long as the flange 7b can be detachably fixed to the core mold 4. Reference numeral 81 indicates a filling gun attached to the core mold 4, and reference numeral 811 indicates a filling port thereof.
Reference numeral 82 indicates an eject pin, and reference numeral 821 indicates an eject port.

The headrest base body 1 is manufactured in the following manner by using the mold for molding the headrest base body.
First, after the cavity mold 3 and the core mold 4 are closed, the foaming beads a from the filling gun 81 into the cavity C (here, polyolefin resin foaming beads such as polypropylene, for example, manufactured by Kanegafuchi Chemical Co., Ltd., trade name “Kaneka Eperan PP45” is used). The foam beads a are filled in the cavity C, and the carrier air passes through the holes 3
1, 41 and vent holes 75 escape to the outside of cavity C.
Incidentally, it is preferable to carry out cracking filling while leaving a narrow gap S on the mold matching surface, because the carrier air can escape from the narrow gap S (FIG. 4).

Next, steam (steam pressure: 2 Kg / cm ² , temperature: about 133 ° C.) is supplied from the steam introducing pipes 53 and 63 into the chambers 5 and 6. The foam beads a in the cavity C are heated and fused by the supply of steam, and are molded into the headrest base 1. Here, chamber chamber 5,
The steam of No. 6 blows out into the cavity C from the ventilation hole 75 and the through holes 31 and 41. The steam is also blown out from the vent hole 75 of the protrusion 7 that hangs down in the center of the concave portion of the cavity mold 3, so that the steam is spread all over the expanded beads a in the cavity C. The steam and condensed water, which have exhausted the latent heat and finished their functions, are discharged from the drain discharge pipe to the outside of the system.

After that, a headrest base 1 as shown in FIGS. 1 to 3 is obtained by demolding the product through a curing process. The constricted portions 71, 72 are provided to prevent the ribs 11, 1 from coming off.
2. Even if the anti-vibration ribs 14 and 15 are formed, when the eject pin is pressed against the eject port 821 at the time of releasing the mold, the headrest base body 1 still has a warmth that can be easily elastically deformed, and polypropylene, polyethylene or the like remains. Because of its flexibility, it is in a state where it can be forced.

In the mold for molding the headrest base having the above-mentioned structure, when the headrest base 1 is manufactured, the structure of the protrusions 7 is simple and can be easily taken out from the mold, and can withstand high speed molding. Then, the maximum thickness at which the foam beads a have to be heat-fused by the blowout of steam into the cavity C from the vent hole 75 formed in the protrusion 7 that hangs down at the center of the cavity mold 3 is the thickness of the headrest base 1. It will be completed in half. Even in the thick (about 120 mm) headrest base 1, there is no defective fusion. Molding cycle is also short. Since the ventilation hole 75 is provided in the projecting body 7 which forms the receiving space 1a for stay insertion and the steam is blown from here, no steam assist or the like is required. Therefore, the product does not have unnecessary holes and is excellent in appearance and strength. Further, the headrest base body 1 made by using such a mold has a holding space 1 formed at the periphery of the receiving space 1a.
The stay 2 can be inserted into the b and 1c to complete an assembled headrest of the headrest base body 1 and the stay 2, and the bad packing of the conventional headrest can be eliminated, and the transportation route of the stay 2 can be simplified. Further, by providing the constricted portion 72 on the protrusion 7, the slip-off preventing ribs 11 and 12 are formed, and the stay 2
Once integrated into the headrest base 1 and housed, the headrest base 1 is integrated to make it easier to remove the stay 2. Since the constricted portion 72 is provided discontinuously, the dividing notch 13 is formed in the shake preventing ribs 11 and 12, so that the slip-out preventing ribs 11 and 12 retain elastic deformation even if the rib thickness is increased to some extent. In addition, the strength is increased to facilitate the work of inserting the stay 2. in addition,
Since the protrusion 7 is detachably attached to the core mold 4 by tightening bolts 78 as a fixing means, the protrusion 7 can be easily removed, and maintenance and design changes can be easily performed.

(2) Example 2 In this example, the projection 7 of Example 1 is replaced by a projection 9 as shown in FIG. The protrusion 9 is the protrusion 9a.
The projection 9a is formed by bending a pipe 91 having a large number of ventilation holes 93 for blowing out steam into a U-shape, and fixing a flat plate 92 to the inside by welding to form a substantially flat shape. The pipe 91 is a holding space 1 for the headrest base body 1.
b, 1c are made, and the same as the stay 2 diameter. The protrusion 9 is bolted to the core mold 4 using the hole 94. The configuration other than the protrusion 9 is the same as that of the first embodiment.
The molding die for the headrest base thus constructed is
Since the holding space 1b, 1c in which the stay 2 is housed is formed in the headrest base body 1 by bending the pipe 91 having the same diameter as the stay 2, the stay 2 becomes the holding space 1b, 1c in addition to the effect of the first embodiment. It fits perfectly, and a simple and highly accurate mold can be manufactured. Further, since the receiving space 1a is carried by the flat plate 92, although a little force is required for inserting the stay 2 into the headrest base body 1, the projection 9 is functional and the molding die for the headrest base body 1 is made inexpensive. Contribute to that.

(3) Embodiment 3 This embodiment is a mold for molding a headrest base body which employs a projection 7'as shown in FIG. The protrusion 7 ′ is the same as the molding die of the first embodiment except that the constricted portion 71 of the first embodiment is not formed. In the mold for molding the headrest base thus configured, since there are no shake preventing ribs 14 and 15 formed by the constricted portion 71, there is a shake toward the inside of the receiving space 1a, but there is a holding space in the outward direction. The shake is restricted on the outer circumferences of 1b and 1c. Therefore, the same effect as that of the first embodiment can be obtained while the protrusion 7'has a simple structure.

The present invention is not limited to those shown in the above embodiments, but can be variously modified within the scope of the present invention depending on the purpose and application. Cavity mold 3, core mold 4, protrusions 7, 7 ', 9
The shape, size, material, etc. of the above are not limited to those in the above embodiment, and can be dealt with according to the purpose. The skin material may be attached to the headrest as the final product, and may be integrated when the headrest base body 1 is molded. Various shapes can be considered for the shape of the constricted portion 72 that forms the slip-off preventing ribs 11 and 12 so that the stay 2 can be easily inserted but not easily pulled out. Holding space 1c in which the connecting portion 22 of the stay 2 is accommodated
Also, regarding the above, it is possible to form the cross section into a triangular shape and make it difficult for the connecting portion 22 to come off due to its wedge action. Polystyrene resin foam beads or the like can also be used as the foam beads.

[0024]

As described above, the molding die for the headrest base body according to the present invention is a molding die for providing the headrest base body of the assembly type headrest. Even a headrest base body exhibits excellent effects such as molding in a short time without causing defective fusion.

[Brief description of drawings]

FIG. 1 is a perspective view of a headrest and a stay according to a first embodiment.

FIG. 2 is a vertical cross-sectional view in which the headrest and stay of FIG. 1 are combined.

3 is a sectional view taken along line IV-IV in FIG.

FIG. 4 is a vertical cross-sectional view of a mold for molding a headrest base.

FIG. 5 is a perspective view of a protrusion.

FIG. 6 is a front view of a protrusion.

FIG. 7 is a plan view of a protrusion.

FIG. 8 is a perspective view of a protrusion according to a second embodiment.

9 is a partially enlarged perspective view of FIG. 7.

FIG. 10 is a perspective view of a protrusion according to a third embodiment.

FIG. 11 is a package diagram of a conventional headrest during transportation.

FIG. 12 is a conventional package view of a headrest during transportation.

FIG. 13 is a relational graph between the wall thickness of the foamed molded product and the molding time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Headrest base 1a Receiving space 11,12 Prevention rib 2 Stay 3 Cavity type 4 Core type 7,7 'Projection body 72 Constriction part 75 Vent hole 78 Bolt 9 Projection body 91 Pipe 92 Flat plate 93 Vent hole C cavity

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B60R 21/055 N // B29K 105: 04 105: 20 B29L 31:58 (72) Inventor Haruo Morita 8 Toei, Fujii-cho, Anjo City, Aichi Prefecture 1 Inoac Corporation Sakurai Plant

Claims (5)

[Claims] 1. A mold for molding a headrest base body made of foamed resin supported through a stay, comprising a cavity mold having a recessed contour that follows the outer shape of the headrest base body, and the recessed depression when closed. A core type in which a hanging protrusion is provided at the center of the head rest, the protrusion being for forming a receiving space into which the stay can be inserted in the headrest base body, and having a substantially flat shape, A mold for molding a headrest base, characterized in that a vent hole capable of being blown into the cavity is formed on the surface thereof. 2. The mold for molding a headrest base according to claim 1, wherein the projection is detachably attached to the core mold by a fixing means. 3. The prevention of the stay from coming out of the stay in the receiving space by making the projection into a flat bottomed bag shape and providing a constricted portion near the tip of the projection to make it easier to pull out the stay. The mold for molding a headrest base according to claim 1 or 2, wherein the rib is integrally molded. 4. The mold for molding a headrest base according to claim 3, wherein the constricted portion is provided discontinuously. 5. The projection is formed in a substantially flat shape by bending a pipe having a large number of vent holes for blowing steam into a U-shape and fixing a flat plate inside the pipe. The mold for molding the headrest base according to 1 or 2.