JPH09276074A - Hard rest manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method not only to restrain the leakage of a foaming raw material and obviate troubles such as step formation and openings, but also to obviate a boring operation for a stay hole. SOLUTION: A parison P suspended from a die head 6 is adapted to take in pin shafts 54 for forming a pair of stay holes, a nozzle for forming a funnel 14 united with a skin bottom surface and erect short plates putting the nozzle therebetween and disposed on the way from one pin shaft to the other, and a blow die is closed. Then, after air is blown into the parison P to mold the skin by blow molding a groove formed up to the halfway from one stay hole toward the other is expanded by the pin shafts, nozzle and short plates to form a slit, and then continuously both stays 21 are arranged from the slit through the stay hole to the out side of the skin to insert an insert 2 into the skin, thereafter inject a foaming raw material g into the skin from the funnel 14 and form a foaming body united with the skin by foam molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a headrest mounted on a seat back of a vehicle or the like.

[0002]

2. Description of the Related Art A headrest is mounted on the upper end of a seat back of an automobile or the like for comfort. One of the methods of manufacturing this headrest is to manufacture a headrest by using a blow-molded skin, incorporating the insert after molding the skin, and then injecting a foaming raw material into the skin. Such a headrest has a slit 92 as shown in FIG. 9 together with a stay hole 91 on the bottom surface 9a of the epidermis after molding the epidermis 9 when inserting the insert 2 as shown in FIGS. Was generally formed by a cutter or the like. The slit 92 was also necessary for injecting the foaming raw material.

[0003]

However, in the above-described manufacturing method, after the insert 2 is inserted into the skin 9, the foam raw material leaks from the slit 92 at the stage of injecting the foam raw material into the skin to perform foam molding. It was easy. Although the foam sheet material S for leak prevention is temporarily attached to the stay 2, it has not been possible to completely suppress the leak. Also, the slit 9
Since the mouth of No. 2 is large, even if the product is finished after foam molding, the slit portion often becomes a defective product with a step or a mouth opening. Further, conventionally, in addition to forming a slit with a cutter or the like, it took a lot of time to open the stay hole 91.

The present invention solves the above-mentioned problems by not only preventing the leakage of the foaming raw material while eliminating the leakage preventing slab, but also solving the problems such as the step and the opening, and the slit by the cutter or the like. It is an object of the present invention to provide a method of manufacturing a headrest that eliminates the need for forming and boring stay holes.

[0005]

In order to achieve the above object,
The gist of the present invention as set forth in claim 1 is a method of manufacturing a headrest in which an insert is inserted into a bag-shaped skin formed by blow molding, and then a foaming raw material is injected into the skin to perform foam molding of the skin integrated with a die head. In the hanging parison, a pair of pin shafts for forming stay holes, a nozzle for forming a funnel that is integrated with the bottom surface of the skin, and a middle of one of the pin shafts to the other pin shaft across the nozzle. Hold the short plate that has been placed upright, and close the blow mold, then,
After blowing air into the parison to form the skin by blow molding, the pin shaft, nozzle, and short plate divide the funnel from one stay hole toward the other stay hole, and in the middle area. By expanding or pushing the concave groove made up to, a slit is formed, then both stays are arranged from the slit to the outside of the epidermis and the insert is inserted into the epidermis,
Thereafter, a foaming raw material is injected into the skin from the funnel, and a foam integrated with the skin is formed by foam molding, which is a method of manufacturing a headrest. Here, in the case of "opening or pushing the concave groove to form a slit", when the groove bottom of the concave groove is already cut to form a slit, the slit formation is not necessary. A method of manufacturing a headrest according to a second aspect of the present invention is the method of manufacturing a headrest according to the first aspect, wherein the funnel is located near one stay hole and the funnel is located substantially in the middle of the slit, and the skin is formed by foam molding. It is characterized by forming an integral foam.

When the pair of pin shafts for forming the stay holes are held and blow-molded as in the first aspect of the invention, since the stay holes are formed on the bottom surface of the blow-molded skin, the stay holes will be formed later. It is not necessary to form stay holes. Further, the funnel is formed on the bottom surface of the skin by the nozzle, and the slit can be easily formed without processing by a cutter or the like by expanding or pushing the concave groove portion formed by the short plate. Further, the slits stop the one funnel from one stay hole and stop toward the other stay holes up to an intermediate area thereof, so that the mouth of the slit is limited to a size necessary for insert insertion. Furthermore, when inserting the insert into the outer skin, even if the mouth is opened as wide as possible, the funnel in the foam mold is firmly held in a funnel shape from both sides at the foam molding stage, so the mouth of the slit is closed. Leakage of foaming raw material is suppressed. In addition, there is no opening or step at the slit. Particularly, when the funnel is arranged so as to be closer to one stay hole and the funnel is located substantially in the middle of the slit, as in the invention according to claim 2,
Since the funnel is retained in the foam mold from both sides in a funnel shape, at the foam molding stage, the slit length is about 1 /
2, the leakage of the foaming raw material due to the formation of the slit, the step defect, etc. are drastically reduced.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method of manufacturing a headrest according to the present invention will be described in detail below. 1 to 6 show one embodiment of a method for manufacturing a headrest according to the present invention. FIG. 1 is a vertical cross-sectional view of a blow mold opened after molding a headrest skin, and FIG. Fig. 3 is a perspective view of the receiving member located, Fig. 3 is an enlarged perspective view of the bottom surface of the skin on which a slit is formed,
4 is a perspective view in which an insert is attached to the blow-molded skin of FIG. 3, FIG. 5 is a vertical cross-sectional view in which the skin integrated with the insert of FIG. 4 is set in a foam mold, and FIG. 6 is foamed in the foam mold of FIG. It is a perspective view of the molded skin integrated foam product.

Prior to the method of manufacturing the headrest, first,
The blow mold B for molding the headrest skin 1 will be described. The blow mold B includes a split mold 4, a receiver 5, and a die head 6 (FIG. 1). The split mold 4 forms a cavity of the headrest skin 1 in the mold closed state. It is a split mold with a two-split structure that opens in both left and right side directions. In the blow mold B, the cavity of the main body of the skin is formed in the closed state, and the stay 21 is formed from the cavity forming the bottom surface of the skin.
Is a portion extending to the outside of the epidermis and forms an annular recess 41 surrounding a pin shaft 54 (described later). The so-called bite-cutting projection 42 narrows the bottom surface of the annular recess 41 so that the tip end thereof approaches (or contacts) the pin shaft 54. The portion from the annular recess 41 to the biting protrusion 42 is
The pin shaft 54 has an axially symmetric shape that is concentric with the axial direction of the pin shaft 54.

Pin shafts 54, 54 are erected and fixed to the receiving tool 5 via blocks 51 at positions where the stay holes 16 are provided (FIG. 2). The pin shaft 54 is for forming the stay hole 16 in the bottom surface 1a of the skin, and is made of a pipe (a round bar is also possible) having a diameter substantially equal to the outer diameter of the stay 21. And
A nozzle 53 is arranged near one pin axis corresponding to the core width H of the insert 2. The nozzle 53 forms the funnel 14 integrated with the bottom surface 1a of the skin, and has a shape in which a short pipe is welded to the tip of the truncated cone. The nozzle 53
Also serves as an air outlet 531 for inflating air by blowing compressed air into the parison after the mold is closed. The nozzle 53 is arranged near the one pin axis, but it is preferable that the distance between the one pin axis 54 and the nozzle 53 is set to about ½ of the core width H of the insert 2. When the funnel 14 formed by the nozzle 53 is arranged at such a position, it is possible to more reliably suppress the leakage of the foaming raw material in the foaming molding step after forming the slit, and to effectively prevent the step and the opening phenomenon which have been conventionally seen. This can be solved (details will be described later). In addition, the nozzle 5
3 is sandwiched between one of the pin shafts 54 and the other pin shaft 54.
The short plates 57 and 58 for slit formation are erected up to the middle of. The plate thickness of the short plates 57 and 58 is 0.2 mm to 2.0 mm.
Within the range of 0.5 mm to 1.0 mm
It is. This is because when the thickness of the short plates 57 and 58 increases, the slit openings become too open. On the other hand, if the plate thickness of the short plates 57, 58 is small, the short plates may be bent during blow molding. If the short plate has a predetermined thickness and the tip edge thereof is sharpened in an acute angle, it is suitable for forming the slit 17. In the present embodiment, the columnar small protrusion 59 is integrally wrapped around the end of the short plate 58. The height of the small protrusion 59 is the same as that of the short plate 58. The receiving member 5 operates to move the piston rod 521 when the air cylinder 52 operates.
By moving forward and backward, it moves up and down. When the receiving tool 5 is placed at the upper point position and the mold is closed, the blow mold B holds the pin shaft 54, the nozzle 53, and the upper half portions of the short plates 57 and 58 (FIG. 1). By blow molding, pin shaft 54 and nozzle 5
3 and the tips of the short plates 57 and 58 are inserted into the parison P. The die head 6 is located above the receiving tool 5 and pushes out and supplies the cylindrical parison P in a semi-molten state.

The molding of the headrest skin 1 starts from under the mold open state of the blow mold (see FIG. 1). The parison P in a semi-molten state is supplied from the die head 6. A thermoplastic resin (here, vinyl chloride resin) plasticized by an extruder (not shown) is extruded from the die head 6 as a cylindrical parison. The lower end of this parison is the pin shaft 54, 54.
The parison P hangs down to cover the nozzle 53 and the short plates 57 and 58.

After ensuring such a state, the left and right split dies 4a and 4b are then closed. By this time, the air cylinder 52 has been actuated and the receiver 5 has been placed at the upper point position. Thus, the parison P grips the pin shafts 54, 54, the nozzle 53, and the short plates 57, 58, and the blow mold B is closed. The split mold 4 forms a cavity in the main body of the skin by closing the mold. As described above, the annular recess 41 and the biting protrusion 42 are formed around the pin axis.
There is a parison P there. After the mold is closed, air is supplied into the parison from the nozzle 53 of the receiver 5 for forming the funnel 14. Compressed air of about 0.5 to 1.1 MPa enters the block 51 through the conduit 9,
It blows out from the air outlet 531. By this injection of compressed air, the parison P sandwiched between the blow molds B swells, is welded and fixed to the cavity surface 46 of the blow mold B, and is shaped into a shape along the mold surface.

A headrest skin 1 is obtained by the blow molding, and a stay 21 is formed on the skin 1.
A band portion 11 is provided at a stay hole portion protruding outward from the area (FIG. 3). The band portion 11 is literally a stay 2
The inner diameter of the stay 1 is substantially equal to the outer diameter of the stay so that 1 can be tightened. Further, a trumpet-shaped funnel 14 is integrally formed on the bottom surface of the skin 1 near the pair of stay holes 16.
Since the nozzle 53 forming the funnel 14 is used as the blow-out air outlet 531, the funnel 14 is inevitably connected to the inside of the bag-shaped skin. Further, the short plates 57 and 58 form a concave groove that divides the funnel 14 from one stay hole 16 toward the other stay hole 16 and reaches an intermediate region thereof. After that, the shaped semi-molten resin is cooled and solidified. After that, the mold is opened (FIG. 1), and after the mold is removed, the valeros component divided by the biting protrusion 41 is removed.
Further, the slit 17 is formed by expanding or pushing the concave groove formed by the short plates 57 and 58. Incidentally, since the recessed groove is formed with the tips of the short plates 57 and 58 positioned not in the parison P, it may be already formed as a slit. Thus, the desired blow-molded skin 1 as shown in FIG. 3 is obtained.

Here, the funnel 14 is preferably divided into two pieces by the slit 17. This is because not only the insert 2 is easily attached to the outer skin 1, but also the divided funnel 14 is easily retained in its original shape by closing the foaming mold 7 by foam molding. In the present embodiment, the short plate 57, so that the slit length L becomes substantially the same as the core body width H,
58 are arranged. The funnel 14 is preliminarily blow-molded so as to be located approximately in the middle of the slit length L. By the way, one end of the slit 17 has one stay hole 16
There is no problem there because it starts from
It is preferable to provide the circular hole 18 by the small protrusion 59 as shown in FIG. When the slit 17 is expanded and the core portion 22 is inserted (described later), a force to tear the end of the slit 17 is applied by the expansion, but when the circular hole 18 is provided, the force can be dispersed. Is. Incidentally, regardless of the small protrusion 59,
The side edges of the short plate 58 may be rounded.

The skin 1 molded as described above is assembled into a headrest as a final product, and the procedure is as follows. First, both stays 21 and 21 are arranged outside the skin through the stay holes 16 and 16, and the insert 2 is inserted into the skin (FIG. 5). Specifically, the slit 17 is opened, the stay tip 211 is inserted into the slit 17, and the stay tip draws an arc so that the slit 1
The stay tip 211 is taken out from the stay hole 16 which is not connected to the stay 7. Then both stays 21,
21 is arranged outside the epidermis, and the insert 2 is inserted into the epidermis 1. In this set, the slit length L is the core width H
With the above, you can do it without much trouble. Therefore, in the present embodiment, the slit length L is substantially the same as the core body width H.

After that, the skin 1 incorporating the insert 2
Is set in the foaming mold 7 (FIG. 6). Then, the mold is closed. By closing the upper lid 71 of the foam mold 7, the split funnel 14 restores its original shape, although the cut line remains. At the same time, due to this restoration, the slit 1 that has been liable to bend and has a tendency to open up to that point
Close the mouth properly without dropping 7. Next, the foaming raw material g is poured from the injection nozzle 8. Foaming raw material g is funnel 14
It is easily poured into the epidermis because it can be received by. Subsequently, the funnel 14 is filled with an injection plug (not shown), and the foam 3 is molded by foam molding at a predetermined temperature. In the foaming stage, as described above, since the slit 17 is in a state where the mouth is properly closed, the foaming raw material g does not leak from there. Also,
Since the foaming mold 7 is designed to tighten the entire circumference of the band portion 11, the foaming raw material g does not leak from the band portion 11.

Thus, after the foaming and curing is completed, the head rest as shown in FIG. 7 is taken out by cooling and demolding. Finally, the funnel 14 is removed from the skin 1 and the desired headrest is completed.

According to the method of manufacturing the headrest having the above-described structure, even if various inserts 2 having the core portion 22 as shown in FIGS. Can be easily attached to the skin 1 to manufacture a headrest integrally formed with the skin. Because of the core portion 22,
The slit 17 is formed on the bottom surface 1a of the epidermis,
The slit 17 is provided from one stay hole 16 to another stay hole 1
Since it has formed only up to the middle area toward 6,
As in the past, there is no need to open the mouth unnecessarily. Further, the slit 17 cleanly closes the mouth as the funnel 14 is shaped by foam molding. Funnel-shaped recess 71
In order to keep the funnel 14 divided by the mold closing in the original shape, the upper lid 71 having the slit 1 forms slits even if the slits are bent up to that point or the slits themselves are open. It is restored to the previous epidermis shape. Especially,
When the funnel 14 is located near one stay hole and the funnel 14 is positioned substantially in the middle of the slit 17, the upper lid 71 of the foaming mold 7 is lifted and repaired when the slit 17 is most flexed. Slit 1
No. 7 closes his mouth more straight. Thus, even without the conventionally required foam sheet material S, there is no leakage of foam raw material in foam molding. The cost can be reduced by eliminating the foam sheet material S. Then, the shape of the funnel 14 is retained, so that there is no step in the slit 17 portion in the vicinity thereof, and as a result, the slit 17 closes the mouth in a straight line,
Foam molding (headrest) does not open. Further, the slit 17 is easily opened by opening the mouth when the insert 2 is inserted into the skin 1, but in the present embodiment, since the circular hole 18 is provided at the end of the slit 17, such a defect is suppressed. . Further, the insert 2 is assembled to the outer skin 1 later, but the slits 17 (concave grooves) and the stay holes 16 which must be provided in the outer skin 1 are jointed together by the short plates 57, 58 and the pin shaft 54 in the blow molding process. Since it is formed, it does not need to be formed by a cutter or the like. If the groove is expanded with a hand or the like, it becomes the slit 17 immediately. Since the funnel 14 is also integrally formed by blow molding with the nozzle 53,
It is easy to inject the foaming raw material g.

In the present invention, the present invention is not limited to those shown in the above embodiments, but can be variously changed within the scope of the present invention depending on the purpose and application. The shape, size, etc. of the skin 1, the insert 2, the foam 3, the split mold 4, the receiving tool 5, the die head 6, and the foam mold 7 can be appropriately selected according to the application.

[0019]

As described above, according to the method of manufacturing a headrest of the present invention, even if the insert having the core body is a rear assembly and the slits are formed, the slits are formed by a cutter or the like. Not only does this eliminate the need for a foamed sheet material, but it also eliminates the problems such as steps and mouth openings that are associated with the conventional slit formation, and is effective in reducing costs and improving quality.

[Brief description of drawings]

FIG. 1 is one mode of a method for manufacturing a headrest according to the present invention,
It is a longitudinal cross-sectional view of the blow mold opened after molding the headrest skin.

FIG. 2 is a perspective view of a receiver located in the lower part of FIG.

FIG. 3 is an enlarged perspective view of the bottom surface of the epidermis where slits are formed.

4 is a perspective view in which an insert is attached to the blow-molded skin of FIG.

FIG. 5 is a vertical cross-sectional view in which a skin having the insert of FIG. 4 integrated therein is set in a foaming mold.

FIG. 6 is a perspective view of a skin-integrated foam product foam-molded by the foam mold of FIG.

FIG. 7 is a perspective view showing a conventional technique, in which foam sheet materials are attached to various inserts.

FIG. 8 is a perspective view of a skin according to the related art.

[Explanation of symbols]

 1 Skin 1a Skin bottom 14 Funnel 16 Stay hole 17 Slit 2 Insert 3 Foam 6 Die head B Blow type P Parison g Foaming raw material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Houji Kawase 7-212-1 Seko, Kobe Town, Anpachi County, Gifu Prefecture

Claims (2)

[Claims] 1. A method of manufacturing a headrest in which an insert is inserted into a bag-shaped skin formed by blow molding, and a foaming raw material is injected into the skin to carry out foam-molding of the skin-integrated, and a pair of parisons hanging from a die head is provided. A pin shaft for forming a stay hole, a nozzle for forming a funnel that is integrated with the bottom surface of the epidermis, and a short plate that stands up from one of the pin shafts to the middle of the other pin shafts with the nozzle interposed therebetween. , And then the blow mold is closed, and then air is blown into the parison to form the skin by blow molding, and then the funnel is divided from one stay hole by the pin shaft, nozzle and short plate. By expanding or pushing the concave groove formed up to the middle area toward other stay holes in this way, a slit is formed,
Next, both stays are arranged from the slits to the outside of the skin through the slits, the insert is inserted into the skin, and then the foaming raw material is injected into the skin from the funnel, and the foam with integral skin is formed by foam molding. A method of manufacturing a headrest, comprising: forming a headrest. 2. The funnel is closer to one stay hole, and
With the funnel positioned approximately in the middle of the slit,
A method for manufacturing a headrest, which comprises forming a foam body integrated with a skin by foam molding.