JPS63251351A - Pad with air bag device - Google Patents

Abstract

PURPOSE:To facilitate sustaining a net in course of forming a cover layer by jointedly sustaining a flexible net at the top surface of an insert corresponding to the top surface of a pad portion to store an air bag with a cover through the medium of a connective arm portion formed on the top surface above the top of the cylindrical side wall of an insert. CONSTITUTION:A folded air bag 1 is stored inside a pad 11 placed on the center boss portion of a handle ring. The pad 11 is composed of a soft synthetic resins cover layer 12 and an insert 13. The cover layer 12 having a thin portion 12a on its top surface and the insert 13 having a flexible net 18 on its top surface make the air bag easy to fracture when it is spread out. The flexible net 18 is jointedly sustained through the medium of a connective arm portion 17a formed on the top surface above the top of a cylindrical side wall 15 of the insert. When the cover layer 12 is to be formed unitedly with the insert 13, it is easy to sustain a net in a mold because one side of the sustaining net 18 is jointedly sustained by a connective arm portion 17a so only the other side has to be sustained with a pair of tweezers.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pad for an airbag device that is installed in an automobile or the like and covers and accommodates an airbag that is inflated at a predetermined time.

<Prior Art> Conventionally, this type of pad has a substantially box shape with an upper wall and a side wall extending downward from the periphery of the upper wall, and when the airbag is deployed, the airbag pops out of the pad and expands greatly above the pad. It was mainly made of soft synthetic resin, and had a thin section on the top wall for breaking at a predetermined position.

Furthermore, in this type of pad, a flexible cotton-like net is embedded in the top wall and side wall excluding the thin part to prevent the pad from breaking and scattering when the airbag is deployed. An annular band made of aramid fiber or the like having high tear resistance was sewn onto the net at the lower part of the side wall (see Japanese Patent Laid-Open No. 110643/1983).

<Problems to be solved by the invention> When manufacturing this type of pad, a net and a band are sewn together, and a covering layer made of soft synthetic resin is applied to the front and back sides in separate processes. Forming it increases the number of man-hours.

Therefore, an insert is made by sewing a net and a band, and the insert is set in a suspended state by being locked to a number of set pins protruding from the mold surface against the mold surface. , it is desirable to form a coating layer.

However, when setting the insert, it is necessary to set the insert in a box shape that is almost the same as the shape of the pad while floating above the mold surface, but the net and band that make up the insert are both flexible. Since it is made of a material that is easily bent, there is a problem that it takes time and effort to set the insert.

The present invention solves the above-mentioned problems, and aims to provide a pad for an airbag device in which an insert can be easily set in a mold when molding a covering layer.

<Means for Solving the Problems> The pad of the airbag device according to the present invention is attached around the airbag that expands at a predetermined time, and is approximately box-shaped and includes an upper wall and a side wall extending downward from the periphery of the upper wall. In addition,
A pad for an airbag device, which is formed by integral molding in which an insert is covered with a covering layer made of soft synthetic resin, and the covering layer is provided with a thin part that breaks when the airbag is expanded at a predetermined position on the upper wall of the pad. The insert has a cylindrical synthetic resin base located on the side wall of the pad, and a flexible base located on the top wall of the pad that is separated at the thin part of the covering layer and connected to the upper part of the base. The base has a mounting part for attaching the pad to a predetermined part and a setting part for the mold used when molding the pad, and extends into the upper wall part of the pad to connect each net. The above-mentioned problem is solved by forming a holding portion that holds the device.

<Operations and Effects of the Invention> In the pad of the airbag device according to the present invention, the insert covered by the coating layer has a cylindrical synthetic resin base located on the side wall of the pad, and a base portion on the pad is disposed on the top of the base. The nets placed on the wall portions are connected to each other, and the base is formed with a mounting portion for attaching the pad to a predetermined portion and a setting portion for setting into a mold used when molding the covering layer.

Therefore, when setting the insert into the mold during molding of the covering layer, the base can be set via the setting part.

At that time, the base is made of synthetic resin and has shape retention properties,
In addition, since it is formed in a cylindrical shape, once the set part of the base is set in the specified mold, the base is easily set in the specified position with it floating above the mold surface, and then it is placed on the top wall of the pad. What is necessary is to lock the net to a predetermined set pin of the mold.

In the pad according to the present invention, each net is connected and held by a holding part that extends from the base and is located within the upper wall portion of the pad. Therefore, on the mold surface of the mold in which each net is set, the base holding part side of each net, that is,
There is no need for a set pin on the base side of each net, and it is only necessary to provide a set pin corresponding to the tip side of each net.

Therefore, when setting each net, it is only necessary to lock the tip end of each net to the setting pin, and each net itself can be easily set in the mold.

Incidentally, if we consider the case where a net in the upper wall part of a conventional pad is set in a mold, in the conventional pad, the net is formed from the pad side wall part to the upper wall part. Therefore, on the mold surface of the mold in which the net on the pad upper wall part is set, in addition to the vicinity of the tips of each net separated by the thin part of the coating layer, there are also areas near the periphery of the pad upper wall part on the base side, Alternatively, unless a set pin is provided near the upper end of the side wall of the pad, the net cannot be set while floating above the mold surface. Therefore, it is considered that the conventional setting of the net of the upper wall portion of the pad into the mold requires a large number of setting pins and is time-consuming.

As described above, the pad for the airbag device according to the present invention has the effect that the insert can be easily set in the mold during molding of the covering layer.

<Example> Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1.2, the pad 11 of the airbag device of the embodiment is arranged around the airbag 1 at the boss portion B of the steering wheel, and has a substantially rectangular upper wall 11A.
and four side walls 11B extending downward from the periphery of the upper wall 11A.The insert 13 is covered with a coating layer 12 made of a soft synthetic resin such as urethane.

The covering layer 12 of the pad upper wall 11A has a thin-walled portion 12a in a substantially H-shape so that it is easily broken when the airbag 1 is expanded.
is formed.

The insert 13 has a substantially rectangular parallelepiped cylindrical base 14 located at the pad side wall 11B, and a thin part 12a of the covering layer 12 located at the pad top wall 11A, which is separated from the base 14 and connected to the upper part of the base 14. (See FIGS. 1 to 3).

This net 18 has a mesh size of approximately 1 mm square openings, is woven from synthetic fibers such as polyamide, and has a flexibility of 7 mm.
have.

The base 14 is made of hard or semi-hard polyamide.

The body portion 15 is made of synthetic resin such as vinyl chloride resin or polyolefin resin. It includes a mounting part 16 and a holding part 17.

The main body portion 15 has a substantially rectangular cylindrical shape located on the pad side wall 11B, and includes a plurality of through holes 15a for preventing peeling of the coating layer 12.

The holding parts 17 are bent and extended from opposing parts in the front-rear direction at the upper part of the main body part 15 so as to enter slightly toward the center of the pad upper wall 11A, and each has an end of the net 18 at its tip. It is buried and maintained. Further, the bent portion of the holding portion 17 is arranged so that when the airbag 1 is expanded, the pad upper wall 11A can be opened smoothly after the thin wall portion 12a is broken, and the airbag 1 can be smoothly expanded above the pad 11. The hinge portion 17a is thin.

The attachment part 16 is used to attach the pad 11 to the backup plate 5 as a member to be attached, which will be described later.
It is composed of a mounting plate portion 16a with an annular groove 16c.

The mounting plate portion 16a is formed to extend downward over the entire circumference of the outer surface of the lower portion of the main body portion 15, and is provided with a plurality of mounting holes 16b at predetermined positions passing through the inner and outer circumferences.

The annular groove 16c is formed over the entire circumference of the lower end surface of the main body part 15 on the inner peripheral side of the mounting plate part 16a, and is used to fit a backup plate vertical wall part 5C, which will be described later.

The insert 13 is integrally molded with the net 18 as an insert when the base 14 is molded.

Therefore, this insert 13 has the advantage of being easier to manufacture than conventional inserts that use sewing.

In addition, the backup plate 5 includes, in addition to the pad 11,
It holds an airbag 1 and a gas supply device 4 for supplying gas to the airbag 1 at predetermined times, and is fixed to a core bar of a steering wheel (not shown).

This backup plate 5 also has an insertion hole 5 in the center.
The bottom wall 5a has a substantially rectangular shape with a hole 5b, and a vertical wall 5c extends upward from the edge of the bottom wall 5aJl. A mounting hole 5d is formed in the vertical wall portion 5c at a position corresponding to the mounting hole 16b of the mounting plate portion 16a of the base portion 14 when the vertical wall portion 5c is fitted into the annular groove 16c of the base portion 14. There is.

By the way, to explain how to assemble each member to the backup plate 5, the gas supply device 4 is inserted into the insertion hole 5b from below.
is inserted, and the flange portion 4a is brought into contact with the lower surface of the periphery of the insertion hole 5b, and the bolt 2a of the annular fastener 2 fixed to the lower part of the airbag 1 is inserted into the flange portion from the upper surface side of the back-up plate bottom wall 5a. 48 and by screwing the nut 3 onto the bolt 2a,
The airbag 1 and gas supply device 4 are assembled to the backup plate 5.

Next, the molding of the pad 11 of this example will be described.

As shown in FIGS. 4 and 5, the mold 7 used for molding is fixed to a movable mold 8 each having mold surfaces 8a and 9a for a predetermined cavity so that a predetermined cavity 7a is formed when the mold is clamped. It consists of type 9.

As shown in FIGS. 4 to 6, on the cavity mold surface 8a of the movable mold 8, there are two in total at the positions on the tip side where the nets 18 of the insert 13 approach each other when set. The set bins 10 are press-fitted.

These center bins 10 include a large diameter part 10a having a larger outer diameter than the mesh of the net 18, and a small diameter part 10b that can be inserted into the mesh of the net 18, and the small diameter part 10b extends from the tip to the base side ( It has a tapered shape in which the outer diameter gradually increases toward the large diameter portion 10a side). Note that the outer diameter of the small diameter portion 1obO on the base side is formed to be slightly larger than the mesh size of the net 18 in order to prevent the net 18 from coming off after being set.

Further, the movable mold 8 is formed with an annular groove 8b into which the mounting plate portion 16a of the insert 13 is fitted when set in a predetermined position, and a predetermined position on the inner circumferential surface of this annular groove 8b is provided with a A hemispherical locking protrusion 8c that is inserted into the mounting hole 16b of the plate portion 16a and can lock the periphery of the mounting hole 16b is formed. That is, the attachment part 16 of the pad 11 also serves as the setting part of the base part 14 in this insert 13.

Describing the method of molding the pad 11 using this mold 7, first, the base 14 of the insert 13 is set in the movable mold 8 when the mold is opened.

At this time, the base 14 is set by fitting the mounting plate portion 16a into the annular groove 8b of the movable mold 8 and locking the periphery of the mounting hole 16b with the locking protrusion 8c. Since it has shape retention properties, it is easy to hold and set, and after setting, the base 14 is formed into a cylindrical shape and is clamped from the outer circumferential side via the locking protrusion 8c. Since it is in a form that allows it to be set in the specified position reliably.

After that, by pulling the tip end of each of the two nets 18 and locking it to the set bin 10, as shown in FIG.
The insert 13 can be easily set in a floating state from the mold surface 8a for the cavity of the movable mold 8, and the same effects as described in the operation and effect of the invention described above can be achieved. - After that, if the mold is clamped and the molding material is injected into the cavity 7a of the mold 7 through a gate (not shown),
As shown in FIG. 5, it is possible to mold a pad 11 in which an insert 13 consisting of a net 18 and a base 14 is embedded, and then, by opening the mold and releasing the mold, a desired pad 11 can be obtained. can.

Then, if the pad 11 thus obtained is fitted with the vertical wall portion 5C within the annular groove 16c of the attachment portion 16 and fixed with the rivets 6 through the mutual attachment holes 16b and 5d,
The pad 11 can be assembled to the backup plate 5 to which the airbag 1 and gas supply device 4 have already been assembled. Incidentally, when attaching the pad 11 by fitting the vertical wall portion 5c of the back-up plate 5 into the annular groove 16c, it is possible to easily position the pad 11 and the backup plate 5 in the vertical direction at the time of attachment. .

In addition, in the pad 11 of the example, when the insert 13 is set in the movable mold 8 during molding of the coating layer 12, the base 14
As shown in FIG. 7, it can be inserted into some of the through holes 15C for preventing peeling of the coating layer 12 in the base main body 15, and these through holes A hemispherical locking protrusion 8d capable of locking the peripheral edge of the mold 15C may be provided on the cavity mold surface 8a of the movable mold 8, and these through holes 15c may be used as a set portion.

Further, in the pad 11 of the embodiment, the attachment portion 16 for the backup plate 5 is shown as being composed of the attachment plate portion 16a provided with the attachment hole 16b and the annular groove 16C, but as shown in FIG. Bolts 26 made of a magnetic material as attachment portions are embedded in predetermined positions at the lower end of the base 14, and flange portions 5e with attachment holes 5f are formed in the backup plate 5 in correspondence with these bolts 26. It may also be configured to be secured with a nut 27 through the attachment hole 5f. When the pad 11 is configured in this way, as shown in FIG. The bolts 26 may be embedded in the mold surface 8a for the cavity and used as a set part.Of course, instead of the bolts 26, nuts made of a magnetic material may be embedded in the lower end surface of the base 14 and used as the mounting part. A corresponding convex magnet may be embedded in the movable mold 8 so that the part can also be used as a set part.

Furthermore, in the pad 11 of the embodiment, the holding part 17 of the base part 14 in the insert 13 was shown to be formed from the same synthetic resin material as the other main body part 15 and the attachment part 16, but the pad 11 shown in FIG. As such, the holding portion 37 may be formed of a polymeric elastic material different from the main body portion 15 and the attachment portion 16, such as soft rubber or thermoplastic elastomer. When forming the holding portion 37 from such different materials,
By appropriately selecting its elasticity, it is possible to adjust the deformation load when the pad upper wall 11A opens after the thin wall portion 12a breaks when the airbag 1 is expanded. It becomes possible to adjust the load.

Furthermore, based on the same concept, as shown in FIG. 11, the holding portion 47 may be configured with a plurality of connecting arms 47a so as to connect the base main body portion 15 and the net 18 at a plurality of locations. In this case, by appropriately selecting the number and cross-sectional area of the connecting arms 47a, the pad upper wall 11
Since the deformation load when A is opened can be adjusted, the deployment load when the airbag is expanded can be adjusted.

Furthermore, in the embodiment, the backup plate 5 is shown as a member to which the pad 11 is attached. However, the member to be attached is not limited to the backup plate 5 fixed to the steering wheel. For example, when attaching the pad to the instrument panel or the back of the front seat, the member to be attached is not limited to the backup plate 5 fixed to the steering wheel. A frame-shaped (ring-shaped) bracket provided on the base plate or the like may also be used.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a pad used in an embodiment of the present invention, Fig. 2 is a perspective view of a pad of the embodiment, Fig. 3 is a perspective view of an insert used in the pad of the embodiment, and Fig. 3 is a perspective view of an insert used in the pad of the embodiment. Figure 4 is a cross-sectional view of the mold when inserts are set in the same example;
Fig. 5 is a sectional view of the mold during molding of the same example, Fig. 6 is a bottom view of the movable mold used in the same example, and Fig. 7 is a sectional view of the mold used in the molding of the same example. FIG. 8 is a sectional view showing how the pad of another embodiment is used; FIG. 9 is a sectional view of the mold showing the insert setting of the pad;
FIG. 0 is a sectional view showing how a pad is used in yet another embodiment, and FIG. 11 is a perspective view showing an insert in still another embodiment. DESCRIPTION OF SYMBOLS 1... Airbag, 11... Pad, 12... Coating layer, 13... Insert, 14... Base, 16... Mounting part, 16b... (Set part) mounting hole, 17... Holding part, 18... Net.

Claims (1)

[Claims] It is installed around an airbag that expands at a predetermined time, and has the following (a)
) to (d): (a) The pad is approximately box-shaped and includes an upper wall and a side wall extending downward from the periphery of the upper wall, and the insert is covered with a soft synthetic resin. (b) The covering layer is provided with a thin wall portion at a predetermined position on the upper wall of the pad, which breaks when the airbag is expanded; (c) The insert is formed of a single piece that covers the pad. A cylindrical synthetic resin base located on the side wall portion, and a flexible net located on the upper wall portion of the pad, separated at the thin wall portion of the covering layer and connected to the upper portion of the base. (d) The base portion includes a mounting portion for attaching the pad to a predetermined portion, and a setting portion for setting the pad into a mold used when molding the coating layer, and an upper wall portion of the pad. A holding portion is provided that extends to the inside and connects and holds each of the nets.