JP2006076347A - Air bag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily divide an air bag cover along a tear line upon inflation of the air bag in an air bag device. <P>SOLUTION: The circular tear line LC comprising grooves for dividing the air bag cover to respective cover pieces in inflation of the air bag and a plurality of, for example, four tear lines L1-L4 radially extending from the circular tear line Lc are provided on an inner surface of the air bag cover 50 for storing the air bag. Openings H1-H4 are provided on crossing part of the circular tear line Lc and the four tear lines L1-L4 respectively and cutting-in parts C for forming an acute angle relative to the respective tear lines are formed on the respective openings H1-H4. The tear lines are easily divided from the cutting-in parts at inflation of the air bag. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an airbag device for a driver's seat.

Conventionally, as an airbag device for an automobile driver's seat, a decorative member (center member) is fixed to a portion on the steering shaft extension of the steering device, and the airbag is folded and stored around the decorative member. Some bags have an air bag cover, but the decorative member with multiple functions such as a horn (horn) function is heavy, so it pops out or holds the decorative member when deployed. If the cover to scatter is scattered and hits the occupant, the occupant may be damaged.
Therefore, it is known that when the airbag is deployed, the airbag cover is opened by inflation of the airbag, and at the same time, the decorative member is fixed so as not to jump out to the passenger side together with the airbag.

FIG. 13 shows an example of an airbag apparatus. As shown in the drawing, a decorative member 21R provided at the center of the steering handle 24R is fitted into a guide sleeve 10R made of an inelastic material attached to a handle shaft, and an end 22R on the passenger side of the guide sleeve 10R is decorative. When the airbag 1R is deployed as shown, the decorative member 21R is held by the guide sleeve 10R so as not to move together with the deployed airbag 1R. (See Patent Document 1).
German Patent No. 1974991C2

  However, in the above-described conventional one, not only the guide sleeve 10R made of an inelastic material is separately provided, but also the guide sleeve 10R needs to be processed so as to accommodate and hold the decorative member 21R in the guide sleeve 10R. Thus, there is a problem that the production is complicated and the manufacturing cost is increased.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to make it possible to easily deploy an airbag by making it easier to cut the tear line when the airbag is deployed. It is. As a result, the concentration of force on the connecting member that fixes the center member (decorating member) to the support member is suppressed, and the connecting member is broken when the airbag is inflated, so that the center member (decorating member) becomes the airbag. To avoid damaging the occupant.

The invention of claim 1 includes an inflatable airbag, an airbag cover that covers the airbag, a support member that fixes the airbag and the airbag cover, a connecting member that attaches a center member to the airbag cover, an airbag An airbag device comprising a plurality of tear lines for dividing the airbag cover into a plurality of cover pieces and opening the airbag cover outward when the bag is inflated, wherein the tear line is a center when the airbag is deployed. A tear line formed around the center member mounting area of the airbag cover so as to separate the device from the open piece of the airbag cover, and a plurality of tear lines extending outward from the tear line. An opening is formed at a portion where the tear lines intersect with each other and hidden by the center member, and the opening intersects. An air bag device characterized by comprising a notch for each tier lines.
According to a second aspect of the present invention, in the airbag apparatus according to the first aspect,
The notch is an airbag device characterized in that the tip thereof forms an acute angle.
A third aspect of the invention is the airbag apparatus according to the first or second aspect, wherein a horn mechanism is attached to the connecting member.
According to a fourth aspect of the invention, there is provided the airbag apparatus according to any one of the first to third aspects, wherein the tear line is a groove formed inside the airbag.

In the present invention, since the tear line is provided in the airbag cover and the opening is formed at the intersection of each tear line, the airbag cover is easily divided along the opening and each tear line when the airbag is inflated. Can do. In addition, since the opening has a cut for each tear line, when the airbag is inflated, stress concentrates on the portion and the tear line can be easily cut. In addition, by making the tip of the cut into an acute angle, the stress on the tip can be more concentrated and the division can be further facilitated.
Further, since the airbag cover can be easily divided, the force does not concentrate on the connecting member to which the center member (decorative member) of the airbag device is attached when the airbag is inflated, and the center member (decorative member) is deployed when the airbag is deployed. ) Does not jump out to the passenger side with the airbag.
Further, since the opening cannot be visually recognized from the outside by the center member (decorative member), the appearance of the airbag device is not impaired.

Hereinafter, an airbag device for a driver's seat according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a front view showing a mounted state of the airbag device, and FIG. 2 is a cutaway side view showing a main part of the airbag device.

  As shown in FIGS. 1 and 2, the airbag device of the present embodiment is incorporated in a vehicle steering device, and includes a support member 20, a center member 30, an airbag 40, and an airbag cover 50. ing.

  The support member 20 is a member that is attached to an end portion side of a steering shaft (not shown) and is disposed at a substantially central portion of the steering wheel 10, and in the present embodiment, the base plate 16, the cushion plate 22, and the connecting member. 28.

FIG. 3 is a perspective view showing the back surface of the base plate 16.
The base plate 16 is formed in a substantially disk shape, and a hole 16h into which the inflator 18 can be fitted is formed at the center thereof, and an airbag cover mounting piece 16a and a base plate 16 are formed on the back side thereof. A mounting piece 16b for mounting itself is cut and raised from the disk surface. In this specification, for convenience, the driver's seat side is referred to as the front side, and the opposite side is referred to as the back side.

4 is a perspective view of the connecting member shown in FIG. 2. FIG. 4A shows the first embodiment, and FIG. 4B shows the second embodiment.
As shown in FIGS. 4A and 4B, the connecting members 28 and 28 'are bent at substantially right angles to the central portions 28a and 28a' having holes 28ah and 28ah 'into which the mounting bolts 27 are fitted. It is composed of a plate-shaped metal piece composed of formed leg portions 28b and 28b ′ and mounting legs 28c and 28c ′ bent at substantially right angles to the leg portions 28b and 28b ′. In addition, the mounting leg 28c according to the first embodiment is formed with a hole or recess 28d for positioning when combined with the cushion plate 22, as will be described later. Further, the mounting foot 28c 'according to the second embodiment is formed with a mounting hole 28e' corresponding to a mounting hole 22a 'of a cushion plate 22' and a mounting hole 16c of the base plate 16 which will be described later. It has come to be tightened together.

FIG. 5 shows a cushion plate according to the first embodiment, FIG. 5A is a rear view thereof, FIG. 5B is a side view showing a part of the cushion plate, and FIG. 6 is a cushion plate according to the second embodiment. FIG. 6A is a rear view of the cushion plate according to the second embodiment, and FIG. 6B is a side view showing a part thereof in cross section.
The cushion plate 22 according to the first embodiment has a substantially rectangular shape as shown in FIG. 5A, which is a rear view thereof, and an insertion hole 22h of the inflator 18 is provided at the center, and the insertion hole 22h Holes 22a into which screws or rivets 22c for attaching the cushion plate 22 to the base plate 16 are inserted are provided at the respective corners around.
Further, the back surface of the cushion plate 22 constitutes a contact surface 22b that can contact the front surface side of the base plate 16 via the airbag 40, and the contact surface 22b is a side view of FIG. 5B. As is apparent, a concave portion 22c formed by drawing, for example, is formed. The concave portion 22 c is formed to a depth substantially equal to the thickness of the mounting foot 28 c of the connecting member 28 when the cushion plate 22 is connected to the base plate 16. The concave portion 22c is formed with a convex portion 22d that can be engaged with and engage with a hole or recess 28d provided in the attachment leg 28c of the connecting member.

With this configuration, when connecting the base plate 16 and the cushion plate 22, the airbag 40 can be sandwiched and fixed between the surface of the base plate 16 and the abutting surface 22b of the cushion plate, and the surface side of the base plate 16 can be The attachment legs 28c of the connecting member 28 can be sandwiched and fixed between the concave portions 22c of the cushion plate 22.
Here, in the cushion plate 22 of the first embodiment, when the projection 22d is engaged with the hole or recess 28d of the coupling member 28, the coupling member 28 is clamped between the base plate 16 and the cushion plate 22. The positioning of the connecting member 28 can be easily performed.

  6A and 6B show a cushion plate 22 'according to the second embodiment. In the figure, the same reference numerals as those in FIGS. 5A and 5B denote the same or corresponding parts. In the second embodiment and the first embodiment of the cushion plate, the concave portion and the mounting hole are arranged outside the concave portion 22c in the first embodiment, whereas the concave portion and the mounting hole are arranged outside the concave portion 22c. The embodiment is different in that the mounting hole 22a ′ is disposed in the concave portion 22c ′, and is the same in other points. When the cushion plate 22 ′ according to the second embodiment is used, the connection member 28 ′ according to the second embodiment is used at the same time to connect the base plate 16 and the cushion plate 22 ′ to the surface of the base plate 16. And the cushion plate abutment surface 22′b, and the attachment leg 28c ′ of the connecting member 28 ′ is sandwiched between the surface side of the base plate 16 and the concave portion 22c ′ of the cushion plate 22 ′. Further, screws are inserted into the mounting holes 22a ′ of the cushion plate 22 ′, the holes 28e ′ of the connecting member 28 ′, and the holes 16c of the base plate 16 and fastened together.

  The inflator 18 is formed in a substantially thick disk shape, and is configured such that gas can be injected when a predetermined impact is detected. The inflator 18 passes through the hole 16h of the base plate 16 and is in close contact with the back surface side of the base plate 16, and is fixed together with the cushion plates 22, 22 'and the like by mounting bolts via the mounting hole 16c of the pace plate 16. The That is, the inflator 18 is fixed in a state of being protruded and disposed on the front side of the pace plate 16, and the jet gas from the inflator 18 is jetted on the front side of the base plate 16.

  In the present embodiment, the center member 30 (decorative member) includes a center main body portion 32 and a horn switch mechanism portion 34 attached to the center main body portion 32 as shown in FIG. The center member 30 may have a decorative shape such as, for example, an emblem of an automobile, instead of or in addition to the horn switch mechanism 34.

  As shown in FIG. 7, the center main body 32 is formed in a substantially bowl shape, and the surface side, that is, the driver side, is open. Further, an insertion hole 32ah into which the mounting bolt 27 can be inserted is formed in the bottom portion 32a of the center main body 32.

  Therefore, the center member 30 inserts the bolt 35 from the hole 32ah of the bottom 32a of the center main body 32 into the hole 52h of the central portion 52 of the airbag cover 50 and the connection holes 28ah and 28ah 'of the connection members 28 and 28'. Further, by fastening the nut 27 to the bolt 35 from the back side of the connecting members 28 and 28 ′, the bolts 35 are attached and fixed to the connecting members 28 and 28 ′ via the central portion 52 of the airbag cover 50, and thus the steering wheel. 10 is arranged in the substantially central portion, that is, on the axial extension of the steering shaft 12.

  As shown in FIG. 2, the horn switch mechanism 34 includes an operating portion 34a that closes the opening of the center main body 32, a biasing portion 34b such as a spring that biases the operating portion 34a toward the surface side, and a horn. A contact portion that is electrically connected through an electric wire and opens and closes in response to a pushing operation of the operation portion 34 a is provided, and is incorporated in the center main body portion 32. Then, by pushing and operating the operation portion 34a disposed at a substantially central portion of the steering wheel 10, the contact of the contact portion is closed and a sound is generated.

FIG. 8 is a cross-sectional view showing an example of the airbag 40.
As shown in FIG. 8, the airbag 40 is configured by sewing two base fabrics 41A and 41B, and includes an airbag body 44 that can be inflated and deployed in a bag shape, and an airbag body. And a cylindrical portion 46 extending toward the inside of the portion 44.

  The airbag main body 44 is formed in a bag shape that can be developed into a flat spherical shape (substantially elliptical shape). Further, an insertion hole 44 h through which the concave portion 52 of the airbag cover can pass is formed in the outer peripheral portion of the airbag main body 44. An air bag attachment hole 42ha is formed at a substantially central portion on the back side of the air bag body 44, and a small screw hole 42hb is formed around the air bag attachment hole 42ha.

  The airbag 40 sandwiches the periphery of the airbag attachment hole 42ha between the periphery of the hole 16h of the base plate 16 and the contact portion 22b of the cushion plate 22, and the base plate 16 and the cushion plate 22 are overlapped. The nut 25 is screwed onto the mounting bolt 27 protruding into the airbag cover 50 from the back side using the inflator mounting hole 16h of the base plate 16. In this state, the gas ejection portion of the inflator 18 (the front side portion of the inflator) is disposed in the airbag 40, and the ejection gas from the inflator 18 is introduced into the airbag 40, so that the airbag body 44 is a steering device. It can be deployed toward the driver's seat.

  The cylindrical portion 46 is formed in a substantially cylindrical shape that extends from the insertion hole 44 h into the airbag main body 44. The front end side opening 46a of the cylindrical portion 46 is formed so as to be able to be latched in the recess 52 of the airbag cover. Specifically, the opening diameter of the distal end side opening 46 a of the cylindrical portion 46 is formed to be smaller than the maximum outer diameter of the recess 2.

  Further, the cylindrical body 46 is formed so that the concave portion 52 can pass through the peripheral body portion 46b excluding the distal end side opening portion 46a. More specifically, the inner diameter of the peripheral body portion 46 b is larger than the maximum outer diameter of the recess 52. Note that the insertion hole, the peripheral body portion 46b, and the distal end side opening portion 46a of the tubular portion 46 are all set to a size that allows the connecting members 28 and 28 'to pass through.

In the form in which the airbag 40 is folded, the tubular portion 46 is folded around the center member 30 and the airbag body 44 is folded around the tubular portion 46. In the state in which the airbag 40 is folded, it is desirable that the airbag attachment hole 42ha, the distal end side opening 46 of the cylindrical portion 46, and the insertion hole 44h are all in agreement. By doing so, the connecting members 28, 28 ′ can be easily exposed to the front side of the airbag 40 through the airbag mounting hole 42 ha, the distal end side opening 46 of the cylindrical portion 46 and the insertion hole 44 h.
The airbag 40 is manufactured by stitching two base fabrics 41A and 41B.

  FIG. 9A is a perspective view of the airbag cover 50. As shown in the figure, the airbag cover 50 is formed in a substantially bowl shape by a resin, and includes a substantially truncated cone-shaped recess 52 for accommodating the center member (decorative member) 30 at the center thereof as already described. ing.

The airbag cover 50 covers the airbag 40 folded around the connecting members 28 and 28 ′, and the bolts 27 are inserted into the mounting holes 52 h of the recess 52 to connect the connecting members 28 and 28 ′. In addition to being fixed, it is fixed to the base plate 16 via the mounting piece 16a as will be described later.
In the state where the center member 30 is attached to the recess 52 of the airbag cover, the surface of the operation portion 34a is substantially flush with the surface of the airbag cover 50 as shown in FIG.

FIG. 9B is a rear view of the airbag cover. As shown in the figure, a groove-like tier that can be cut (broken) on the back surface of the airbag cover 50 leaving a central recess 52 fixed by the connecting members 28 and 28 'when the airbag 40 is inflated and deployed. A line is formed. That is, on the back surface of the airbag cover 50, when receiving the inflation pressure of the airbag, a circular tear line Lc around the central recess 52, and the central cover 52a can be divided into a plurality of cover pieces 50a, leaving the central portion. A plurality of, for example, four tear runs L1 to L4 extending radially from the tear line Lc are provided.
Here, in the illustrated example, the circular tear line Lc around the central recess 52 includes an intersection with the plurality of tear lines L1 to L4 in advance. Are formed at the intersections of the openings H1 to H4 with the tear lines L1 to L4. In other words, the ends of the openings H1 to H4 are cut with respect to the tear lines L1 to L4. An incision C having an acute angle is formed.
By providing the openings H1 to H4 with the cuts C in the tear line Lc of the airbag cover 50 in this way, concentrated stress acts on the ends of the openings and the cuts at the time of inflation. As a result, the open piece of the airbag cover 50 50a can be opened easily and reliably.

Note that the tear line around the central recess 52 is not necessarily circular, and may be an ellipse or any other shape as long as it makes a round around the recess. Further, the shapes of the openings HI to H4 are not limited to the substantially crescent shape, and the shape of the notch C is preferably such that the tip has an acute angle as shown in the figure, but it is not necessarily limited to the shape. In short, it is only necessary that a cut of any shape is provided at the intersection with the tear line Lc so that the tear lines L1 to L4 can be easily opened when the airbag is inflated.
Since the opening 52c is blocked by the center member (decorative member), the opening 52c is not visible from the outside, and there is no possibility of deteriorating the appearance of the airbag device.
The airbag cover 50 is divided into cover pieces 50a when the airbag 40 is inflated, and attachment pieces 50b provided for the respective cover pieces 50a are provided on the metal base plate 16 so that they can be opened independently. It is screwed individually to each of the plastically deformable mounting pieces 16a that are cut and raised from the disc portion and projecting from the back side of the base plate 16.

  In the above configuration, when the airbag 40 is inflated and deployed, the airbag cover 50 is pushed by the force and the tear line L around the center member 30 is pushed from the openings H1 to H4 to the end, that is, from the notch C. The broken cover pieces open to the outside, leaving a central recess 52 in the shape of a bowl. At this time, the cover pieces 50a are completely separated from each other, and a tear line is formed so that each cover piece 50a can be opened independently, and the mounting piece 16a of the base plate 16 is made of a metal that is a plastically deformable material. Therefore, the attachment piece 50a once deformed does not return to the original state.

  FIG. 10 is a view of each cover piece 50a in an opened state as viewed from the base plate 16 side. As shown in the figure, the airbag cover 50 is divided into cover pieces 50a when the airbag 40 is inflated, and the airbag 40 maintains the torsionally deformed state, so that the airbag 40 applies pressure from the inflator 18. It is configured to receive and smoothly expand.

When the airbag is inflated, when the portion of the tubular portion 46 formed in the airbag passes through the central recess 52 of the remaining airbag cover, the airbag 40 is located outside the back surface of the central recess 52. It is guided by a frustoconical surface whose diameter gradually increases toward the front side and expands outward.
That is, the airbag 40 is inflated while the tubular portion 46 passes through the periphery of the stationary central recess 52 of the airbag cover.
When the airbag 40 is inflated in this way, the inflation of the airbag 40 forward is slightly delayed due to the resistance when the body portion 46b of the cylindrical portion 46 passes through the recess 52. The pressure with which the airbag 40 hits the driver directly can be reduced.

Next, the assembly procedure of the airbag device will be described.
When the first airbag 40 is assembled, first, the airbag main body 42 and the cylindrical body 46 are appropriately folded in the surface side region of the base plate 16, and this is folded into the cylindrical body of the airbag 40 ′ in the airbag cover 50. The insertion holes 43h of 46 are stored in a state facing the recess 52 of the cover, and the mounting feet 28c and 28c 'of the connecting members 28 and 28' are respectively recessed portions 22c and 22c 'on the back surface of the cushion plates 22 and 22'. In this state, the peripheral edge portion of the airbag mounting hole 42ha is sandwiched between the peripheral edge portion of the hole 16h and the abutting portions 22b and 22b ′ of the cushion plates 22 and 22 ′. The cushion plates 22 and 22 'are overlapped. Thereafter, the nut 25 is screwed into the mounting bolt 27 protruding into the airbag cover 50 from the back side using the inflator mounting hole 16h of the base plate 16, and the horn switch mechanism 34 is assembled in the center main body 32. The base plate 16, the cushion plate 22, and the inflator are screwed.

  At this time, the connecting members 28, 28 ′ are arranged in the tubular body 46 through the airbag attachment hole 42 ha ′ of the tubular body 46 or the front end side opening 46 a. Further, the distal end side opening 46a of the cylindrical body 46 is formed so as to have a diameter smaller than the maximum diameter of the central recess 52 of the airbag cover 50 or is sandwiched, and when the airbag is inflated, The cylindrical body 46 is prevented from coming out of the central recess 52. Thereby, the assembly of the airbag apparatus shown in FIG. 2 is completed.

The deployment operation of this airbag device will be described.
First, the inflator 18 is ignited by the impact detection at the time of a vehicle collision or the like, gas is generated by the inflator 18, and this gas is introduced into the airbag 40. The airbag cover 50 receives the force when the airbag 40 starts to inflate, and breaks along the tear lines L1 to L4 and the cuts C and the openings H1 to H4 of the LC, that is, leaving the central recess 52, Each air cover piece 50a expands radially.

  After the airbag cover 50 is broken, at the initial stage where the airbag main body 44 begins to expand, the airbag main body 44 expands around the inflator 18 as shown in FIG. Extends on the front side extension of the center member 30 in the airbag main body 44.

  After the airbag body 44 is inflated to some extent, the portion of the airbag body 44 that is unevenly distributed below the center member 30, that is, the portion of the airbag body 44 that is lower than the tubular portion 46 is mainly used. As shown in FIG. 12, the airbag main body 44 is inflated and deployed into a flat spherical shape that is a natural inflated shape so as to push the portion where the insertion hole 44h of the airbag main body 44 is formed upward. To do.

  According to the present embodiment, since the center member 30 can be attached so that it cannot be popped out when the airbags 40, 40 ′ are deployed, the airbag 40 is not ejected when the airbag 40 is deployed. Can be inflated and deployed.

  In addition, although the above description was taken taking the airbag which has a cylindrical part inside as an example, the airbag accommodated in the airbag cover of the airbag apparatus of this invention is not only the above, For example, it is a matter of course that the center member may be an airbag that does not have a cylindrical portion that passes through a hole provided in the airbag when the airbag is inflated.

It is a front view which shows the airbag apparatus of this invention. It is sectional drawing which shows the principal part of the airbag apparatus of this invention. It is a perspective view of the back surface of a base plate. It is a perspective view of a connection member. The cushion plate which concerns on a 1st Example is shown, FIG. 5A is the back view, FIG. 5B is a side view. The cushion plate which concerns on a 2nd Example is shown, FIG. 6A is the back view, FIG. 6B is a side view. It is sectional drawing of a center member main body. It is sectional drawing which shows an airbag. An airbag cover is shown, FIG. 9A is the perspective view, FIG. 9B is a back view. It is the figure which showed the mode of the expansion of the airbag cover when an airbag expand | swells. It is sectional drawing which shows the initial state of expansion | swelling of an airbag. It is sectional drawing which shows a state when an airbag completes expansion | swelling. It is sectional drawing of the conventional airbag apparatus.

Explanation of symbols

10 ... steering wheel, 16 ... base plate, 18 ... inflator, 20 ... support member, 22, 22 '... cushion plate, 28, 28' ... connecting member, 30 ..Center member, 32 ... Center main body, 40 ... Airbag, 46 ... Cylindrical part, 50 ... Airbag cover, 52 ... Recess, H1-H4 ... Opening,
C: Cut.

Claims (4)

An inflatable airbag, an airbag cover that covers the airbag, a support member that fixes the airbag and the airbag cover, a connecting member that attaches a center member to the airbag cover, and an airbag cover when the airbag is inflated In an airbag device comprising a plurality of tear lines for dividing the cover into a plurality of cover pieces and opening the airbag cover outward,
The tear line includes a tear line formed around the center member mounting area of the airbag cover so as to separate the center device from the open piece of the airbag cover when the airbag is deployed, and outward from the tear line. Consists of extended tier lines,
An airbag device, wherein openings are formed in portions where the tear lines intersect with each other and hidden by the center member, and the openings have cuts for the intersecting tear lines. In the airbag apparatus described in Claim 1,
The airbag apparatus according to claim 1, wherein a tip of the cut has an acute angle. In the airbag apparatus described in Claim 1 or 2,
An airbag device, wherein a horn mechanism is attached to the connecting member. In the airbag apparatus as described in any one of Claim 1 thru | or 3,
The airbag device according to claim 1, wherein the tear line is a groove formed inside the airbag.

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