JPH0647769A - Method for molding pad of air bag device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a method of forming a pad of an airbag device capable of reducing the number of set pins holding a flexible reinforcing insert. A method of molding a pad 11 of an airbag device by injecting and curing a molding material into a product cavity 33 of a molding die 31 through a gate. The pad 11 is an integrally molded body including a lid portion 13 and a bracket portion 17 that is formed to project near the base end of the lid portion 13 with a hinge portion 15 interposed. A flexible reinforcing insert 19 is embedded from the bracket portion 17 through the hinge portion 15 to the rear surface side of the lid portion 13. Then, the flexible reinforcing insert 19 is held by the set pin 39 formed on the bracket shaping portion 45 of the product cavity 33 so as to project from the mold,
The gate 47 is located at the end of the base of the lid shaping unit 43, and the molding material is injected from the gate 47.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a pad of an air bag device arranged in front of a passenger seat of an automobile. More specifically, the present invention relates to a method for molding a pad of an airbag device by injecting and curing a molding material through a gate into a product cavity of a molding die.

[0002] In the following description, a net insert is used as an example of the flexible reinforcing insert to be embedded in the pad, but the same applies to flexible woven fabrics, non-woven fabrics, perforated films and the like.

[0003]

2. Description of the Related Art As a pad 11 of an airbag device of this type, there is, for example, a structure shown in FIGS.

The pad 11 includes a lid portion 13 and a lid portion 13
It is an integrally molded body including a bracket portion 17 which is formed in the vicinity of the end of the base portion of the lid portion 13 so as to project in the back direction of the lid portion 13 with a hinge portion 15 interposed therebetween. Then, a net insert (flexible reinforcing insert) 19 is embedded from the bracket portion 17 through the hinge portion 15 to the back surface side of the lid portion 13. The net insert 19 is for reinforcing the hinge portion at that time because the lid portion 13 is suddenly opened when the air bag is actuated.

The bracket portion 17 has a plurality of mounting holes 17
a is formed. These mounting holes 17a are for inserting the bolts 29 fixed to the case 27 and fixing the bracket portion 17 with screws.

The pad 11 is one of the components of the airbag device M arranged inside the instrument panel 21 in front of the passenger seat of the automobile, and is arranged in the opening 2 of the instrument panel 21. It

The air bag device M has an air bag 25 that expands at a predetermined time, a pad 11 that covers the folded air bag 25, a case 27 that holds the air bag 25 and the pad 11, and a case 27 that holds the air bag 25 inside the case 27. Being an airbag 25
An inflator (not shown) that supplies a predetermined gas to
It is a configuration provided with.

The pad having the above-mentioned structure is constructed, for example, by injecting a molding material into a product cavity of a molding die through a gate.
Cure and shape. At this time, the product gate, which is a material injection port into the product cavity, is usually located on the tip side of the lid.

As the molding material, a polyester-based / polyolefin-based thermoplastic elastomer, or
An elastic polymer material such as polyurethane was used. The net insert 19 is made of a fiber such as polyamide woven in a stitch shape.

[0010]

Since the net insert has flexibility when forming the above-mentioned pad, movement and deformation of the net due to material flow are prevented. In particular, the net insert is partially removed from the set pin. In order to prevent it from appearing on the outer surface (design surface) of the lid, a large number of set pins for net inserts (including net holding pins)
Must be arranged on a predetermined mold surface of the molding die.

However, such an increase in the number of set pins is not desirable because it takes time to set the net insert or is unsuitable for automation, and the molding die becomes complicated.

In view of the above, an object of the present invention is to provide a method of forming a pad of an airbag device, which can reduce the number of set pins holding a flexible reinforcing insert.

[0013]

The present invention solves the above problems by the following constitution.

A method for molding a pad of an air bag device by injecting and curing a molding material into a product cavity of a molding die through a gate, wherein the pad comprises a lid and a base of the lid. It is an integrally molded body that consists of a bracket part that protrudes in the back direction of the lid part with a hinge part near the end of the part. Reinforcing flexibility from the bracket part through the hinge part to the back side of the lid part. In the configuration in which the insert is embedded, the flexible reinforcing insert is held by the set pin formed by projecting from the mold to the bracket shaping portion of the product cavity, and the gate is the original portion of the lid shaping portion. The molding material is located at the end and the molding material is injected from the gate.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same parts as those in the above-described example are designated by the same reference numerals, and the description thereof will be omitted in whole or in part.

(1) Pad 1 applied by the molding method of the embodiment
The configuration of No. 1 will be outlined again (see FIG.
3).

The lid 13 is an integrally molded body which is composed of a lid 13 and a bracket 17 which is formed in the vicinity of the base end of the lid 13 so as to project in the back direction of the lid 13 with a hinge 15 interposed therebetween.
Net insert (flexible reinforcing insert) 1 from the bracket 17 to the hinge 15 to the back side of the lid 13
9 is buried.

(2) The molding die 31 used in the molding method of the embodiment is usually for injection molding, and has a structure as shown in FIG. 1, for example.

A fixed mold (upper mold) 35 and a movable mold (lower mold) 37 for forming a product cavity 33 capable of molding the pad 11 at the time of mold clamping are provided. The tip of the bracket shaping portion 45 of the movable mold 37. A pin 39 forming the mounting hole 17a of the bracket portion 17 is formed at the portion so as to project upward. Further, a slide core 41 which slides the product horizontally so that the product can be released is incorporated. The product cavity 33 is composed of the lid shaping section 43 and the bracket shaping section 45.

In the above structure, the gate 47 for injecting the molding material is located at the end of the base portion of the lid end shaping portion 43. That is, the fixed line 35 and the movable line 37 of the paring line P.P. On L, it is formed at the end of the lid shaping section 43 on the side of the bracket shaping section 45. In the figure, 4
A runner 9 is connected to a sprue (not shown).

(3) Next, using the above molding die,
A method of forming the pad will be described.

The net insert 19 is spread and placed at a predetermined position with respect to the movable die 37 in a state where the slide core 41 is retracted in the die open state. At this time, the net insert 19 holds the mesh by locking it with the pin (set pin) 39. In this state, the net insert 19 does not move even if the net insert 19 is pulled toward the tip of the lid shaping unit 43. In addition, although the set pin of the net insert is also used as the pin 39 for forming the mounting hole here, a set pin may be provided separately, and further, the formation surface of the set pin is the bracket portion shaping portion. The surface may be on either side, and the holding manner is not limited to the locking, but may be a manner of sandwiching and fixing between the pin tip and the lid shaping surface.

Subsequently, the mold is clamped, and as shown in FIG. 1, the molding material is injected from the molding machine, and then the molding material is injected from the gate 25 into the molding cavity 33 through the sprue and runner 49. 11 can be molded.

At this time, at this time, the net insert 19
The flow of the material at the time of injecting the molding material (refer to the arrow in FIG. 1) is such that
It acts bidirectionally on the tip side of the bracket shaping section 45, that is, in the direction in which the net insert is pulled bidirectionally, and
Since it acts to press the lid back surface shaping surface 43b side,
There is no risk that the net insert 19 will be exposed and formed on the design surface side of the lid portion 13 or that it will be formed with large wrinkles. Further, the molding material flow is usually slightly more dominant toward the lid shaping portion 43 side in the material injection direction than toward the bracket shaping portion 45 side, but the net insert 19 is
Since the pin is held by the bracket shaping section 45, the net insert 19 does not flow.

Thereafter, the mold is opened to release the pad 11, and post-processing such as deburring is performed.

[0026]

The pad molding method of the present invention is such that the net insert (flexible reinforcing insert) is held by the set pin formed by projecting from the mold to the bracket shaping portion of the product cavity. Since the gate is located at the base end of the cover end applicator and the molding material is injected from the gate, the following operational effects are achieved.

The material flow at the time of pouring the molding material acts on the net insert bidirectionally on the tip side of the lid shaping section and the tip side of the bracket shaping section, that is, in the direction of pulling the net insert, and Since it acts to press the part back surface to the shaping surface side, there is no possibility that the net inserter is exposed and molded on the design surface side of the lid portion or is molded with large wrinkles. Further, the resin flow is usually slightly more dominant toward the lid tip shaping part side in the material injection direction than to the bracket part shaping part side, but the net insert is pin-shaped at the bracket shaping part. Since it is held, there is no risk of the net insert being washed away.

Therefore, it is not necessary to provide a set pin for holding the net insert other than the pin formed in the bracket shaping portion of the product cavity. That is, the number of holding pins for holding the flexible reinforcing insert can be reduced as compared with the related art. That is, since the mold structure can be simplified and the number of arrangements of the set parts can be reduced, the work of setting the net insert in the set part is simplified, and the insert work is simplified. The automation of the set becomes easy, which contributes to reduction of man-hours and manufacturing cost for pad manufacturing.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state of a molding die used in an embodiment of the present invention during mold clamping.

FIG. 2 is a sectional view showing an example of a pad to which the present invention is applied.

FIG. 3 is a perspective view of the pad.

[Explanation of symbols]

 11 ... Pad, 13 ... Pad lid, 15 ... Pad hinge, 17 ... Bracket, 31 ... Mold, 33 ... Product cavity, 35 ... Fixed mold, 37 ... Movable mold, 39 ... Mounting hole formation Pins (set pins), 41 ... Slide core, 43 ... Lid part shaping part, 45 ... Bracket part shaping part, 47 ... Gate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Kuriyama 1 Ochiai, Nagachi, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd. Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A method for molding a pad of an airbag device by injecting and curing a molding material into a product cavity of a molding die through a gate, the pad comprising a lid portion and the lid. Is a unitary molded body composed of a bracket portion projecting in the back direction of the lid portion with a hinge portion interposed in the vicinity of the base end of the lid portion, the back surface of the lid portion extending from the bracket portion to the hinge portion. In the configuration in which the flexible reinforcing insert is embedded up to the side, the flexible reinforcing insert is held by a set pin formed by projecting from the mold to the bracket shaping portion of the product cavity, and the gate is A method for molding a pad of an airbag device, comprising: locating the molding material at the base end of the lid shaping part and injecting the molding material from the gate.