Patent Description:
Airbag devices have generally become standard equipment in vehicles in recent years. An airbag device is a safety device which is operated in the event of an emergency such as a vehicle collision, retaining and protecting passengers utilizing an airbag cushion which expands and deploys based on gas pressure. Prior to expansion and deployment, the airbag cushion is folded or rolled into a small, stowed form for installation in various places in a vehicle.

For example, patent Document <NUM> discloses a knee protection airbag device including an airbag that is folded and stowed on a lower surface side of a column cover covering a steering column and an inflator that supplies inflation gas to the airbag. In the knee protection airbag device of Patent Document <NUM>, an airbag into which the expansion gas discharged from the inflator flows protrudes from the stowed site on the lower surface side of the column cover, and expands and deploys so as to cover the lower surface side of the column cover. This enables protecting both knees of the driver.

In an emergency, an airbag needs to rapidly expand and deploy. However, if the housing does not readily open, the expansion and deployment of the airbag will be hindered, and expanding and deploying an airbag at the desired timing will be difficult. Therefore, there has been a demand for the development of technology enabling housing to open more readily.

In light of these issues, an object of the present invention is to provide an airbag module where the housing opens readily during expansion and deployment of the airbag. Document <CIT> discloses an airbag module according to the preamble of claim <NUM>.

To resolve the issues described above, a representative configuration of an airbag module according to the present invention includes the features of claim <NUM>.

According to the invention, extension of the bent portion of the connecting member causes an opening of the upper part of the housing to open. In other words, the opening of the housing readily opens during expansion and deployment of the airbag cushion. As the housing opens readily in this manner, speed of the airbag cushion deployment can be increased. This stabilizes deployment behavior and enables restraining the occupant more rapidly. Thus, occupant injury value can be reduced. In addition, the housing opening readily improves resistance of internal pressure reduction of the cushion during airbag cushion deployment. Therefore, the amount of cushion base material is anticipated to be reduced and the housing plate thickness is anticipated to be reduced enabling potential cost reduction.

The first member includes two side walls with an L shaped cross-section and the second member includes the two remaining side walls with an L shaped cross-section.

The first member includes three side walls and the second member includes two side walls with an L shaped cross-section and includes the remaining side wall.

These configurations also enable obtaining the same effect as described above.

The bent portion of the connecting member described above may have a hat shape protruding in a direction away from the first member or second member. Thus, sufficient deformation can be ensured by the bent portion, enhancing the effect described above. In addition, varying the length of the bent portion of the connecting member enables control of the discharge angle (discharge direction) of the airbag cushion during expansion and deployment as well as deployment amount of the airbag cushion.

The present invention enables providing an airbag module with the housing readily capable of opening when the airbag expands and deploys.

Different embodiments will hereinafter be described in detail with reference to the attached drawings. Dimensions, materials, other specific numerical values, and the like indicated in the embodiments are merely examples for ease of understanding of the invention and do not limit the present invention unless otherwise noted. Note that in the present specification and drawings, elements having essentially identical functions and configurations are labeled with identical symbols in order to omit redundant descriptions along with an illustration of elements not directly related to the present invention.

<FIG> is a perspective view of an airbag module <NUM> according to embodiment that does not belong to the invention. <FIG> is an overall perspective view of the housing <NUM> of the airbag module <NUM>, and <FIG> is a perspective view of the housing <NUM> of <FIG> observed from a different direction. <FIG> is a schematic cross-sectional view of the leg part of <FIG> taken along the line A-A. For ease of understanding, <FIG> illustrates an airbag cushion <NUM> and an inflator <NUM> not shown in <FIG> as dashed lines.

Note that the airbag module <NUM> of the present embodiment is assumed to be used as a knee airbag device that protects the knee portion of the passenger. However, the airbag module <NUM> of the present embodiment is not limited thereto, and can be used as an airbag for a motorcycle. In addition, the airbag module <NUM> of the present embodiment may also be used as an airbag to protect the occupant's head and chest.

As illustrated in <FIG>, the airbag module <NUM> of embodiment <NUM> includes an airbag cushion <NUM>, an inflator <NUM>, and a case type housing <NUM>. The inflator <NUM> is provided in the airbag cushion <NUM>. The airbag cushion <NUM> is stowed in the housing <NUM> in a folded or rolled up state.

As illustrated in <FIG>, the housing <NUM> is rectangular and has a first member <NUM> and a second member <NUM>. The first member <NUM> has three side walls 130a, 130b, and 130c. The second member <NUM> includes three side walls 140a, 140b, and 140c that are opposite the first member <NUM> and overlap inside the first member <NUM>.

As illustrated in <FIG>, leg parts <NUM> and <NUM> extend from bottom wall <NUM> and bottom wall <NUM> respectively of the first member <NUM> and the second member <NUM>. The housing <NUM> is secured with the leg parts <NUM> and <NUM> to the frame <NUM> by a bolt <NUM> and a nut <NUM>. In the airbag module <NUM> of the present embodiment, the bolt <NUM> connects the first member <NUM> and the second member <NUM>. Therefore, when the first member <NUM> and second member <NUM> rotate relative to one another, a rotational shaft 152a is the central axis of the bolt <NUM>.

As illustrated in <FIG>, in embodiment <NUM>, the housing <NUM> is provided with a pin <NUM> and a bracket <NUM> as a member for guiding the rotation of the first member <NUM> and the second member <NUM>. The pin <NUM> is secured to the first member <NUM>. The bracket <NUM> is arc-shaped and is secured to the second member <NUM>. An arc-shaped slot 164a in which the pin <NUM> is slidably inserted is formed in the bracket <NUM>.

<FIG> is a diagram describing the behavior of the housing of <FIG> during expansion and deployment of the airbag cushion <NUM>. Prior to expansion and deployment of the airbag cushion <NUM>, the pin <NUM> is positioned at start point P1 of the frame <NUM> slot 164a as illustrated in <FIG>. Furthermore, when the airbag cushion <NUM> expands and deploys, the first member <NUM> is pushed out by the pressure thereof. Thus, the pin <NUM> moves in the slot 164a of the bracket <NUM> and the first member <NUM> rotates relative to the second member <NUM> around a rotational axis <NUM> (central axis of the bolt <NUM>). Furthermore, as illustrated in <FIG>, the pin <NUM> moves to the end point P2 of the slot 164a and the opening <NUM> of the upper side of the case type housing <NUM> opens up.

With the configuration described above, rotation of the first member <NUM> with respect to the second member <NUM> causes the opening on the upper side of the housing <NUM> to open up. In other words, the opening of the housing <NUM> readily opens during expansion and deployment of the airbag cushion <NUM>. As the housing <NUM> opens readily in this manner, speed of the airbag cushion deployment can be increased. This stabilizes deployment behavior and enables restraining the occupant more rapidly. Thus, occupant injury value can be reduced. In addition, the housing <NUM> opening readily improves resistance of internal pressure reduction of the cushion during airbag cushion <NUM> deployment. Therefore, the amount of cushion base material is anticipated to be reduced and the housing <NUM> plate thickness is anticipated to be reduced enabling potential cost reduction.

Also, with the configuration described above, the pin <NUM> and the bracket <NUM> are provided to enable guiding the rotation of the first member <NUM> relative to the second member <NUM> in the housing <NUM>. Thus, stable operation is feasible and the desired behavior can be reliably obtained.

Further in the present embodiment, as illustrated in <FIG>, the housing <NUM> includes bearings <NUM> that are connected to the bolt <NUM> provided as a rotation axis 152a. Therefore, friction of the bolt <NUM> when the first member <NUM> rotates relative to the second member <NUM> can be reduced. Therefore, since the first member <NUM> and the second member <NUM> rotate more smoothly, the effects described above can be improved.

<FIG> is a diagram illustrating the variation of the housing of <FIG>. As illustrated in <FIG>, the housing <NUM> of the embodiment described above is formed from a combination of a first member <NUM> including three side walls 130a, 130b, and 130c and a second member <NUM> including three side walls 140a, 140b, and 140c.

The housing <NUM> illustrated in <FIG> is formed from a combination of a first member <NUM> having an L shaped cross section and including two side walls 182a and 182b and a second member <NUM> having an L shaped cross section and including the remaining side wall 184a and side wall 184b. The housing 120b illustrated in <FIG> is formed from a combination of a first member <NUM> including three side walls 130a, 130b, and 130c and a second member <NUM> having an L shaped cross section and including two side walls 186a and 186b. The housing 120c illustrated in <FIG> is formed from a combination of the first member <NUM> including three side walls 130a, 130b, and 130c and a second member <NUM> including the remaining side wall.

In this manner, the cross section of the first member and the second member does not necessarily have to be in the shape of a U. If four side walls surrounding the airbag cushion <NUM> can be formed, members with a shape other than an L shape can be used to the same effect as that described above.

<FIG> is a perspective view of the airbag module <NUM> according to embodiment <NUM> that does not belong to the invention and is an overall perspective view of a housing <NUM> of an airbag module <NUM>. Note, the airbag cushion <NUM> and inflator <NUM> (see <FIG>) are not shown in <FIG>. In addition, the bolt <NUM> (<FIG>) that provides the rotational shaft 152a is not shown.

The housing <NUM> of the airbag module <NUM> illustrated in <FIG> is formed of a first member <NUM> having three side walls 130a, 130b, and 130c and a second member <NUM> including the remaining side wall. The housing <NUM> is provided with a pin <NUM> that is a member for guiding rotation and an L shaped bracket <NUM>. The pin <NUM> is secured to the first member <NUM>. The bracket <NUM> has a slot 264a for the pin <NUM> to slide in and is secured to the second member <NUM>. Differing from the slot 164a of embodiment <NUM> illustrated in <FIG>, the slot 264a is linear.

With the configuration described above, the second member <NUM> is pushed from the pressure when the airbag cushion <NUM> expands and deploys. Thus, the pin <NUM> slides in the slot 264a of the bracket <NUM> and the second member <NUM> rotates relative to the first member <NUM> with a short side 240a of the second member <NUM> as a rotation axis. Furthermore, as illustrated in <FIG>, an opening 210a on the upper side of the case type housing <NUM> opens up. Therefore, the airbag module <NUM> of embodiment <NUM> can achieve the same effect as the airbag module <NUM> of embodiment <NUM>.

Note, the pin <NUM> slides in an arc-shaped path in the linear slot 264a so the slot 264a is preferably provided with sufficient width to prevent interference with the pin <NUM>.

<FIG> is a perspective view of an airbag module <NUM> according to embodiment <NUM> that corresponds to the present invention. <FIG> is an overall perspective view of the housing <NUM> of the airbag module <NUM>, and <FIG> is a perspective view of the housing <NUM> of <FIG> observed from a different direction. <FIG> is an expanded perspective view of the vicinity of the connecting member <NUM>.

As illustrated in <FIG>, the housing <NUM> of the airbag module <NUM> of embodiment <NUM> includes a first member <NUM> and a second member <NUM>. The first member <NUM> has three side walls 330a, 330b, and 330c. The second member <NUM> has three side walls, side wall 340a, side wall 340b, and side wall 340c that are arranged inside the first member <NUM>. The first member <NUM> and second member <NUM> are connected by the connecting member <NUM>.

As illustrated in <FIG> and <FIG>, the connecting member <NUM> includes a first connecting member <NUM> and a second connecting member <NUM>. The first connecting member <NUM> includes a joint part <NUM>, a connecting part <NUM>, and a bending part <NUM>. The joint part <NUM> is the location for joining with the first member <NUM> and the connecting part <NUM> is the location for connecting to the second connecting member <NUM>. The bending part <NUM> that is a bending location is formed between the joint part <NUM> and the connecting part <NUM>.

The second connecting member <NUM> includes a joint part <NUM>, a connecting part <NUM>, and a bending part <NUM>. The joint part <NUM> is the location for joining with the second member <NUM> and the connecting part <NUM> is the location for connecting to the first connecting member <NUM>. A bending part <NUM> that is the bending portion that is separated from the first member or the second member is formed between the joint part <NUM> and the connecting part <NUM>.

The connecting part <NUM> of the first connecting member <NUM> and connecting part <NUM> of the second connecting member <NUM> are secured by a bolt <NUM> illustrated in <FIG> and a nut <NUM> illustrated in <FIG>. Thus, the first member <NUM> and second member <NUM> are connected by means of the first connecting member <NUM> and second connecting member <NUM>.

With the configuration described above, upon expansion and deployment of the airbag cushion <NUM>, the pressure thereof causes the bending parts <NUM> and <NUM> that are the bent portions of the connecting member <NUM> to extend in the directions of the arrows D2 and D3 illustrated in <FIG>. Thus, the first member <NUM> separates from the second member <NUM> in the direction of the arrow D1 illustrated in <FIG> causing an opening 310a (see <FIG>) of the upper part of the case type housing <NUM> to open. Therefore, the airbag module <NUM> of embodiment <NUM> can achieve the same effect as the airbag module <NUM> of embodiment <NUM>.

In particular, in the present embodiment, the bending parts <NUM> and <NUM> that are bent portions have a hat shape protruding in a direction away from the housing <NUM>. Thus, sufficient deformation can be ensured by the bending parts <NUM> and <NUM>, enhancing the effect described above.

Note, in the present embodiment, a configuration using two connecting members (first connecting member <NUM> and second connecting member <NUM>) was illustrated but the configuration is not limited to this. For example, if the connecting part <NUM> of the first connecting member <NUM> is connected to the second member <NUM>, the effect described above can be achieved without requiring the second connecting member <NUM>.

The embodiment <NUM> of the present invention described above is a preferred example of the present invention, and other embodiments can be implemented or performed by various methods. In particular, unless described otherwise in the specification of the present application, the invention is not limited to the shape, size, configurational disposition, and the like of parts illustrated in detail in the attached drawings. Furthermore, expressions and terms used in the specification of the present application are used for providing a description, and the invention is not limited thereto, unless specifically described otherwise.

Therefore, it is obvious that a person with ordinary skill in the art can conceive various changed examples or modified examples within the scope described in the scope of the claims, which is understood to naturally belong to the technical scope of the present invention.

The present invention can be used as an airbag module for a knee airbag or an airbag for a motorcycle (bike).

Claim 1:
An airbag module (<NUM>), comprising:
a folded or rolled airbag cushion;
an inflator provided in the airbag cushion; and
a case type housing (<NUM>) for stowing the airbag cushion, wherein
the housing includes:
a first member (<NUM>) forming at least one side wall (330b) of the rectangular shape
a second member (<NUM>) that forms the remaining two or more side walls (340b) the rectangular shape; and
a connecting member (<NUM>) that connects the first member and the second member, and the connecting member has a bent portion (<NUM>) separated from the first member or second member and upon expansion and deployment of the airbag cushion, extension of the bent portion of the connecting member separates one of the first member or second member from the other causing an opening on the upper side of the case type housing to open,
characterized in that the first member includes three side walls (330a, 330b, 330c) and the second member includes three side walls (340a, 340b, 340c) including the remaining side wall (340b) and two contiguous side walls (340a, 340c) on either side thereof and overlaps with the first member