Patent Description:
Currently, nearly all vehicle steering wheels are equipped with a driver seat airbag device. The airbag cushion of the driver seat airbag device is primarily stored in the central hub of the steering wheel, and expands and deploys in front of an occupant by cleaving a plastic cover member or the like by the expansion pressure thereof. For example, in the steering wheel <NUM> of Patent Document <NUM>, when the airbag <NUM> expands and deploys, the cover body <NUM> is configured to open upward. In Patent Document <NUM>, by bringing the cover body <NUM> into contact with the rim part <NUM>, the airbag <NUM> is supported from the forward side of the vehicle by the cover body <NUM>.

Normally, the shape of an airbag cushion for the driver seat is determined based on the assumption that the occupant is seated in the seat in a normal posture. However, while traveling, the occupant may not always be in a constant posture, for example, they may lean forward unexpectedly. When the occupant is in a non-normal position relative to the seat sitting position (commonly known as out-of-position), the airbag cushion may contact the head of the occupant from below in the event of an emergency situation. In this case, the airbag cushion will cause the head of the occupant to retroflex backwards. Due to the structure of the human body, it is known that movements that rotate the head, such as retroflexing backwards, tend to place a burden on the body.

In addition, in recent years, a system that transmits a steering operation using an electrical signal is becoming popular. This manner of steering system is called steer-by-wire (SBW) where steering force is transmitted using a wiring harness rather than a steering shaft, and is attracting attention in terms of operability and design.

In the steer-by-wire steering system described above, rotation of greater than <NUM>° as in conventional systems is not required so the rim can be something other than a circular shape. For example, the rim may be provided only to the left and the right of the central hub or the part above the center on a conventional circular rim, in other words, the rim part 5a in <FIG> of cited document <NUM> may be omitted. The rim with the upper center omitted is beneficial in terms of design and visibility of meter displays, but the head of the occupant moves forward more readily as well. For example, when the rim part 5a in <FIG> of Patent Document <NUM> is omitted, the head of the occupant more readily moves forward, and the cover body <NUM> and the airbag <NUM> are more likely to push the head up from below. Document <CIT> discloses a driver seat airbag device, comprising a steering wheel of a vehicle and an airbag module according to the preamble of claim <NUM>.

In view of these issues, an object of the present invention is to provide a driver seat airbag device that takes safety into consideration when activated.

In order to resolve the problems described above, a representative configuration of a driver seat airbag device according to the present invention comprises the features of claim <NUM>.

With the configuration described above, even if the head of the occupant is positioned above the cover member, the cover doors open to the left and right so upward thrust of the head of the occupant by the cover doors can be prevented. Additionally, since the cover member also opens up to the upper region in addition to the frontal region, if the head of the occupant is positioned above the cover member, expansion pressure of the airbag cushion can more readily be dispersed toward the front of the vehicle. Herein, with the configuration described above reducing and dispersing force causing upward thrust on the head of the occupant suppresses backward retroflexion of the head and improves safety of the occupant.

The tear lines described above branch from near the center of the upper region to the left and right along the front edge of the upper region, extend towards the sides of the upper region, extend at each of the sides of the upper region towards the frontal region respectively, reaching the frontal region, and then respectively extending along the sides of the frontal region,
parts of the tear lines are omitted along the sides of the frontal region respectively that do not cleave, forming a pair of side hinge regions that are hinges for the two cover doors. This configuration enables implementing cover doors that open to the left and right and widely opening the upper region of the cover member.

The pair of side hinge regions are formed such that the respective axes thereof are parallel when viewed directly facing the frontal region. This configuration suitably enables implementing cover doors that open to the left and right.

The tear line described above may extend from near the center of the frontal region to the bottom end of the frontal region, branching from the bottom towards each of the sides of the frontal region, and up to the pair of side hinge regions. This configuration also suitably enables implementing cover doors that open to the left and right.

The one or more cover doors of the upper region are formed over <NUM> or more towards the front of the vehicle from the chin of an occupant, who is in contact with the steering wheel and in a state where motion toward the front of the vehicle has culminated. Causing the upper region of the cover member to open along these dimensions efficiently suppresses upward thrust of the airbag cushion on the head of the occupant.

The one or more cover doors described above are preferably formed to include a range in the upper region from the frontal region up to a point more forward in the vehicle than the module installation surface. This configuration also enables causing the upper region of the cover member to open widely.

A part of the tear line provided in the frontal region described above is preferably thinner than the tear line provided in the upper region. With this configuration, the cover member normally first cleaves from the frontal region while if the frontal region does not readily open, for example, if in contact with an occupant, cleaving starts from the upper region enabling dispersing expansion pressure of the airbag cushion toward the front of the vehicle.

The airbag cushion described above includes:.

The one or more discharge ports described above are preferably formed on a path connecting the inflator and tear line. The flow-regulating material of this configuration enables efficient cleaving of the cover member tear line.

The one or more discharge ports described above can discharge gas diagonally from the side opposite the frontal region. This configuration enables dispersing expansion pressure of the airbag cushion toward the front of the vehicle.

According to the present invention, a driver seat airbag device that takes safety into consideration when activated can be provided.

Preferred embodiments according to the present invention 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 diagram illustrating an overview of a driver seat airbag device (hereinafter referred to as airbag device <NUM>) according to an embodiment of the present invention. <FIG> is a diagram illustrating a state before activation of the airbag device <NUM>. Hereinafter, regarding <FIG> and other diagrams, a vehicle front-rear direction is illustrated by the symbols F (Front) and B (Back), a vehicle width direction of the vehicle by the symbols L (Left) and R (Right), and a vehicle up-down direction by the symbols U (Up) and D (Down).

The airbag device <NUM> is applied in the present embodiment as the airbag for the driver's seat for vehicles with a steering wheel on a left side (front row left side seat <NUM>). Hereinafter, descriptions are made assuming the front row left side seat <NUM>, for example, a vehicle outer side in the vehicle width direction (hereinafter, vehicle outer side) refers to a left side of the vehicle, and an inner side in the vehicle width direction (hereinafter, vehicle inner side) refers to a right side of the vehicle.

The airbag cushion (hereinafter, referred to as cushion <NUM> (see <FIG>) of the airbag device <NUM> is stored in a folded or rolled condition or the like in front of a seating position of the seat <NUM>, inside a central hub <NUM> of a steering wheel <NUM>. At this time, the cushion <NUM> is stowed together with an inflator <NUM> (see <FIG>) that supplies gas; forming an airbag module <NUM> (see <FIG>).

The steering wheel <NUM> is assumed to be of a configuration in which occupant operation is converted into an electrical signal and transmitted to the wheels, and the shape of a rim <NUM> gripped by the occupant is a different shape as compared to a conventional circular shape. As a result, the rim <NUM> has a shape of only being provided on the left, right and below the central hub <NUM> while the central upper part above the hub <NUM> is omitted.

<FIG> is a diagram illustrating a vehicle after activation of the driver seat airbag device <NUM>. The cushion <NUM> begins to expand based on gas from the inflator <NUM> (see <FIG>), opening a cover member <NUM> of the hub <NUM> (see <FIG>). The cushion <NUM> expands and deploys at the front of the seat <NUM> sitting position and restrains the upper torso, head, and chest of the occupant attempting to move forward from the seating position. The cushion <NUM> has a circular shape as viewed from the seating position side, and is formed by overlaying a plurality of panels that form the surface thereof and then stitching or adhering.

<FIG> is a diagram illustrating the after activated airbag module <NUM> in <FIG> from various directions. <FIG> illustrates the airbag module <NUM> of <FIG> viewed from slightly above the exterior of the vehicle. In <FIG>, a portion of the panel configuring the cushion <NUM> is cut out to expose the internal inflator <NUM>.

The cushion <NUM> has a shape similar to a truncated cone, with the diameter widening from the steering wheel <NUM> side (see <FIG>) toward the occupant side (vehicle rear side). The cushion <NUM> is formed from a plurality of panels and contains a front panel <NUM> positioned on the occupant side, a rear panel <NUM> positioned on the steering wheel <NUM> side (see <FIG>), and a side panel <NUM> connecting the front panel <NUM> and the rear panel <NUM> to form a side portion of the cushion <NUM>. The side panels <NUM> are also provided with vent holes 126a for discharging gas.

The inflator <NUM> is a device for supplying gas, and in the present embodiment, a disk type is used. Regarding the inflator <NUM>, a portion thereof formed with a gas outlet port <NUM> inserted into the cushion <NUM> through a rear panel <NUM>, is activated based on an impact detection signal transmitted from a sensor (not shown) to supply gas to the cushion <NUM>. The inflator <NUM> is provided with a plurality of stud bolts <NUM>. The stud bolts <NUM> pass through a rear panel <NUM> of the cushion <NUM> to fasten to the module installation surface <NUM> inside of the hub <NUM> of the steering wheel <NUM> (see <FIG>). The cushion <NUM> is also secured to the steering wheel <NUM> by fastening of the stud bolts <NUM> to the module installation surface <NUM>.

Note that examples of currently prevailing inflators include: types filled with a gas generating agent and that burns the agent to generate a gas; types filled with a compressed gas and supplies the gas without generating heat; hybrid types that utilize both a combustion gas and a compressed gas; and the like. Any of these types of inflators can be used as the inflator <NUM>.

<FIG> illustrates an occupant <NUM> normally seated in the cushion <NUM> and seat <NUM> as viewed from the left side in the vehicle width direction. The cushion <NUM> can restrain the occupant <NUM> from the head <NUM> to chest <NUM>, and to the abdomen <NUM> thereof, with the occupant side front panel <NUM> as the primary restraining surface. In an emergency, the occupant <NUM> attempting to move forward in the vehicle will make contact at an early stage from the upper portion 104a of the cushion <NUM>. The width of the upper portion 104a of the expanded and deployed cushion <NUM> is thicker than the width of the lower part 104b of the cushion <NUM>, enabling suitably absorbing the load from the head <NUM> of the occupant <NUM>. With the cushion <NUM> of the present example, the width in the front-rear direction of the vehicle decreases toward the lower part 104b, and therefore, the lower part 104b readily enters the narrow space between the steering wheel <NUM> and the abdomen <NUM>.

<FIG> is a diagram illustrating the steering wheel <NUM> in <FIG> from various directions. <FIG> is an enlarged view of the steering wheel <NUM> in <FIG>. A cover member <NUM> made of resin is attached to the central hub <NUM> of the steering wheel <NUM>. The frontal region <NUM> on the occupant side of the cover member <NUM> is a region formed as a flat surface or a curved surface that widens on the front face of the cover member <NUM> in the field of view as viewed from the passenger seated normally in the seat <NUM> (see <FIG>), with an emblem <NUM> or the like applied thereon.

In the following description, the upper and lower and left-right direction directions of the cover member <NUM> refer to the upper and lower left and right directions of the steering wheel <NUM> in the neutral position. Specifically, the vertical direction of the cover member <NUM> is the vertical direction when the frontal region <NUM> is viewed from the front of the steering wheel <NUM> in the neutral position, and does not represent the strict vertical direction. Additionally, the left-right direction of the cover member <NUM> is the left-right direction when the frontal region <NUM> is viewed from the front of the steering wheel <NUM> in the neutral position. Note that the front and rear of the cover member <NUM> means the forward side and rearward side of the vehicle as viewed from a position above the cover member <NUM> and does not mean a strict horizontal line in the front-to-back direction.

The cover member <NUM> in the present embodiment is configured so as to cleave open during expansion and deployment of the cushion <NUM> (see <FIG>) and two cover doors 154a and 154b open to the left and right. The cover doors 154a and 154b are defined by a tear line <NUM> provided in the cover member <NUM>.

<FIG> is a cross-sectional view along line A-A of the hub <NUM> of the steering wheel <NUM> in <FIG>. The airbag module <NUM> is stowed inside the hub <NUM> located in the center of the rim <NUM> (see <FIG>). The airbag module <NUM> is installed on the module installation surface <NUM> inside the hub <NUM> and is covered by the cover member <NUM>. The tear line <NUM> is provided in a groove on the side of the airbag module <NUM> of the cover member <NUM>. The tear line <NUM> induces a cleavage in the cover member <NUM> when subjected to inflation pressure from the cushion <NUM> by reducing the plate thickness of the cover member <NUM>.

<FIG> is a perspective view illustrating the cover member <NUM> in <FIG> by itself. <FIG> illustrates a cover member <NUM> prior to cleavage. The frontal region <NUM> of the cover member <NUM> covers the passenger side of the airbag module <NUM> (see <FIG>), and the upper region <NUM> covers the upper side of the airbag module <NUM>. The tear line <NUM> is provided from the frontal region <NUM> of the cover member <NUM> to the upper region <NUM>.

<FIG> is a diagram illustrating the cover member <NUM> after cleavage. The cover member <NUM> of the present embodiment is made of resin, and in a normal temperature environment (approximately <NUM>, for example), the expansion pressure of the cushion <NUM> causes cleaving starting at the tear line <NUM> (see <FIG>). In the cleaved cover member <NUM>, the two cover doors 154a and 154b open to the left and right when viewed from the proximity of the center of the frontal region <NUM>.

Regarding the cover doors 154a and 154b, the left cover door 154b includes an emblem <NUM> and the frontal region <NUM> and upper region <NUM> of the cover member <NUM> are formed so as to be divided into the left and right. The cover member <NUM> is formed with hinges 160a and 160b that connect a body of the cover member <NUM> to the cover doors 154a and 154a such that the cover doors 154a and 154b do not go flying.

As illustrated in <FIG>, the tear line <NUM> extends continuously from the center of the frontal region <NUM> to the vicinity of the center of the upper region <NUM> while avoiding the emblem <NUM>. In the upper region <NUM>, the tear line <NUM> extends from the central vicinity toward the front end <NUM> and branches to the left and right along the front end <NUM> to extend toward the side portions 164a and 164b of the upper surface region <NUM>, respectively. Also, the tear line <NUM> extends towards the frontal region <NUM> of side parts 164a and 164b of the upper region <NUM>. Upon reaching the frontal region <NUM>, the tear line <NUM> extends along each of the sides 168a and 168b of the frontal region <NUM>. Also, upon reaching the lower end <NUM> of the frontal region <NUM> below the emblem <NUM>, the tear line <NUM> branches from the lower end <NUM> towards the respective sides 168a and 168b of the frontal region <NUM>.

Note that in the descriptions above, vicinity of the center of the frontal region <NUM> indicates an area including the area center of gravity and vicinity with the frontal region <NUM> in a plane and viewed vertically from above and the area including the geometric center position of the frontal region <NUM> and the vicinity thereof. In addition, the center region of the upper region <NUM> means when viewing the upper region <NUM> as a plane perpendicularly from above, the area center of gravity thereof and nearby areas, the geometric center position of the upper region <NUM> and nearby areas, or simply the areas close to the centerline of the upper region <NUM> in left and right directions.

A part of the tear line <NUM> along the side parts 168a and 168b of the frontal region <NUM> is omitted and so cannot be broken. This non-breakable part forms a pair of side hinge regions 170a and 170b that are hinges 160a and 160b (see <FIG>) of the cover door 154a.

The pair of side hinge regions 170a and 170b are formed respectively on side parts 168a and 168b of the frontal region <NUM> where the tear line <NUM> is not present. The pair of side hinge regions 170a and 170b are formed such that the respective axes (see <FIG>) of the hinges 160a and 160b are parallel when viewed directly facing the frontal region <NUM>. With this configuration, the cover doors 154a and 154b are able to mutually open broadly in a <NUM>° direction relative to each other to form a wide opening.

<FIG> is a cross sectional view taken along line B-B of the steering wheel <NUM> of <FIG>. <FIG> illustrates the state prior to cleaving of the cover member <NUM>. As described above, the frontal region <NUM> of the cover member <NUM> covers the occupant side of the airbag module <NUM>. Also, the upper region <NUM> extends from the upper end of the frontal region <NUM> toward the front of the vehicle and covers the upper side of the airbag module <NUM>.

<FIG> illustrates the state after cleaving of the cover member <NUM>. In this embodiment, the upper region <NUM> (see <FIG>) of the cover member <NUM> is configured with a wide opening in consideration of safety when the cushion <NUM> (see FIG. <NUM>(a), and the like) expands and deploys. More specifically, compared to the module installation surface <NUM> where the inflator <NUM> of the airbag module <NUM> is installed and secured, an opening in the upper region <NUM> extends to a position beyond the module installation surface <NUM> by a distance S1 towards the front of the vehicle.

To achieve the configuration described above, the cover doors 154a and 154b (see <FIG>) are formed to include a range of the upper region <NUM> from the frontal region <NUM> side to a point more forward in the vehicle than the module installation surface <NUM> (see FIG. That is, the tear line <NUM> extends from near the center of the frontal region <NUM> to a point more forward on the vehicle than the module installation surface <NUM> near the center of the upper region <NUM>.

<FIG> is a diagram illustrating the occupant <NUM> in a non-normal seating position (normally called out-of-position) when the cushion <NUM> expands and deploys as in <FIG>. <FIG> illustrates the cushion <NUM> and the occupant <NUM> as viewed from the left side in the vehicle width direction. The angle of the steering wheel <NUM> can be suitably changed compared to <FIG>, and in a normal vehicle, the upper part is tilted more toward the front of the vehicle.

The cushion <NUM> may approach the head <NUM> of the occupant <NUM> from below, for example, when the occupant is leaning out of the seat <NUM> (see <FIG>). In this case, with the airbag device <NUM> according to the present embodiment, upward thrust of the cushion <NUM> is suppressed by the cover doors 154a and 154b to enable the cover doors 154a and 154b (see <FIG>) to open to the left and right. Therefore, even if the head <NUM> of the occupant <NUM> is located above the cover member <NUM>, upward thrust of the head <NUM> of the occupant <NUM> caused by the cover doors 154a and 154b can be prevented.

In addition, in the airbag device <NUM> according to the present embodiment, the upper region <NUM> part of the cover member <NUM> also is opened in addition to the frontal region <NUM>. In particular, the upper region <NUM> opens widely to a position of the vehicle more forward than the module installation surface <NUM>. Thus, when the head <NUM> of the occupant <NUM> is positioned above the cover member <NUM>, the cushion <NUM> can expand toward the front of the vehicle from the head <NUM> so as to avoid the head <NUM> of the occupant <NUM>. At this time, the expansion pressure toward the upper side of the cushion <NUM> is also dispersed toward the front of the vehicle, so thrust upward of the head <NUM> of the occupant <NUM> by the cushion <NUM> is suppressed.

<FIG> is a diagram illustrating an occupant <NUM> in proximity to the steering wheel <NUM> in <FIG>. <FIG> illustrates a steering wheel <NUM> before activation of the airbag device <NUM> and an occupant <NUM> in a non-normal seating position corresponding to <FIG>. <FIG> is a diagram illustrating the cover member <NUM> and the head <NUM> of the occupant <NUM> of <FIG> as viewed from above. In the airbag device <NUM>, as a guide for the dimension of the opening of the upper region <NUM>, for example, the upper region <NUM> preferably opens over a range of <NUM> or more from a chin <NUM> of the occupant <NUM> toward the front of the vehicle with the occupant in contact with the steering wheel <NUM> and movement toward the front of the vehicle stops (S2 > <NUM>).

Here, in the US Federal Motor Vehicle Safety Standards (FMVSS) standard <NUM> (FMVSS208) there is a definition related to the front collision test of the vehicle, and the evaluation of a restraining device such as an airbag or a seat belt is also defined therein with a non-normal seating position (out-of-position (hereinafter, abbreviated as OOP)). In the OOP test for airbags, the load experienced by the human body dummy is measured while the human body dummy is in proximity to the airbag.

In the OOP test described above, when the steering wheel <NUM> (see <FIG>) of the present embodiment is applicable, the steering wheel <NUM> is inclined toward the front of the vehicle at an angle of approximately <NUM>° to <NUM>° in the same manner as a normal steering wheel, but there is no rim <NUM> at the upper part. Therefore, the human body dummy that mimics the occupant <NUM> moves forward without the head <NUM> coming into contact with a structure, and the chin <NUM> and chest <NUM> are in proximity to the cover member <NUM>. When forward movement of the occupant culminates, opening of the cover member <NUM> upper region <NUM> over a range of <NUM> or more toward the front of the vehicle than the chin <NUM> of the occupant <NUM> (S2 > <NUM>), as illustrated in <FIG>, enables the cushion <NUM> to expand in front of the head <NUM> as illustrated in <FIG>, suppressing upward thrust of the cushion <NUM> on the head <NUM>.

Examples of an occupant <NUM> [sic] described above include a Hybrid III dummy and a Thor dummy that are human body dummies specified in FMVSS208. Hybrid III dummies are available in a plurality of models that mimic people of different physiques and genders. The Thor dummy is developed as a successor to the Hybrid III dummy, and models only the average body mass male.

Of the human body dummies, the AF05 model of the Hybrid III dummy mimics a female with a small build. In general, when a small adult female operates a vehicle, the seat <NUM> (see <FIG>) is often positioned further forward as compared to that of an adult male and is thus in a posture closer to the steering wheel <NUM>. Therefore, the head of a small adult female is more likely to be positioned over the cover member <NUM> of the steering wheel <NUM> as compared to an adult male or the like. In addition, small adult females have lower body tolerance and are more prone to injury than adult males.

Thus, with regards to the airbag device <NUM>, with the chest <NUM> of the AF05 model in contact with the frontal region <NUM> of the cover member <NUM>, the cover member <NUM> upper region <NUM> can be opened over a distance of <NUM> or more towards the front of the vehicle from the chin <NUM> of the AF05 model. This makes it possible to suitably ensure the safety of a small adult female. Furthermore, by applying the technical concept of this airbag device <NUM>, even for a steering wheel with a different shape or dimensions, the steering wheel cover member is opened over a range of <NUM> or more toward the front of the vehicle from the chin of an occupant whose forward movement has culminated so safety of the occupant can be suitably ensured.

<FIG> is again referred to. A series illustrating cleaving of the cover member <NUM> of the present embodiment. For example, in the tear line <NUM>, a portion of the tear line <NUM> provided in the frontal region <NUM>, in particular, a first thin part 156a is provided in a range along the emblem <NUM>, as a portion having the thinnest plate thickness. Furthermore, of the tear line <NUM>, subsequent to a first thin part 156a, a second thin part 156b is provided over a range branching in <NUM> directions from a front end <NUM> of the upper region <NUM> as thin portions. With this configuration, the cover member <NUM> will normally tear first from the frontal region <NUM> starting from the first thin part 156a. Furthermore, if the occupant <NUM> in a non-normal seating position (FIG. <NUM>(a)) contacts the frontal region <NUM> but the first cleavage part does not cleave, the pressure thereof is applied to the upper region <NUM> and causes cleavage with a starting point of the second thin part 156b. That is, when the occupant <NUM> is in a non-normal seating position, the cover member <NUM> can be easily cleaved from the upper region <NUM>, and the cushion <NUM> can expand and deploy in front of the head <NUM> of the occupant <NUM> to disperse the expansion pressure and prevent thrusting up of the head <NUM> of the occupant <NUM>.

With this airbag device <NUM>, the cover doors 154a and 154b (<FIG>) opening to the left and right and the cover member <NUM> upper region <NUM> open widely so upward thrust of the cushion <NUM> on the head <NUM> of the occupant <NUM> (see <FIG>) can be reduced and dispersed; suppressing backward retroflexion of the head <NUM> and thus ensuring safety of the occupant <NUM> upon activation.

Modified examples of each of the above-described components are described below that do not belong to the invention. In each of the diagrams <FIG>, the same sign is attached to the same elements as those already described, and descriptions of the previously mentioned elements are omitted. In the following description, components having the same name as a component already described are assumed to have the same function unless otherwise specified, even if marked with a different sign.

<FIG> is a diagram illustrating a first modified example (cover member <NUM>) of the cover member <NUM> in <FIG>. <FIG> illustrates the cover member <NUM> corresponding to <FIG> before cleavage. The cover member <NUM> of the present embodiment differs from the cover member <NUM> in that two cover doors 202a and 202b open up and down. The cover doors 202a and 202b are formed by bisecting the cover member <NUM> frontal region <NUM> such that an emblem <NUM> is included in the upper cover door 202b.

A tear line <NUM> cuts across the frontal region <NUM> avoiding the emblem <NUM>, reaches the side parts 168a and 168b of the frontal region <NUM>, and extends along the side parts 168a and 168b to a point close to the side parts 164a and 164b of the upper region <NUM>. From there, the tear line <NUM> extends close to the front end <NUM> of the upper surface region <NUM> along the side parts 164a and 164b of the upper region <NUM>. Herein, the tear line <NUM> extends along the side parts 164a and 164b of the upper region <NUM> to a point more forward in the vehicle than the module installation surface <NUM> of the upper region <NUM> (see <FIG>). Furthermore, a front hinge region <NUM> is formed as an end point of the tear line <NUM> in a region more forward in the vehicle than the module installation surface <NUM> of the upper region <NUM> as a region where the tear line <NUM> is omitted and that cannot be cleaved, provided as a hinge for the cover door 202a.

<FIG> illustrates the cover member <NUM> corresponding to <FIG> after cleavage. In this variation, if the head <NUM> of the occupant <NUM> is positioned above or below the cover member <NUM>, opening of the cover door 202a more to the front of the vehicle than the module installation surface <NUM> enables the cover door 202a to prevent the cushion <NUM> from thrusting up the head <NUM> of the occupant <NUM> from below. In addition, widely opening the upper region <NUM> of the cover member <NUM> enables dispersing the cushion <NUM> expansion pressure to a point more toward the front of the vehicle than the head <NUM> of the occupant <NUM>. As described above, even in this configuration, backward retroflexion of the head <NUM> can be reduced and dispersed by reducing upward thrust on the head <NUM> of the occupant <NUM>, and the safety of the occupant <NUM> can be improved.

<FIG> is a diagram illustrating the second to fourth modified examples of the cover member <NUM> in <FIG>. Each of the cover members differ in structure from that of the cover member <NUM> of <FIG> depending on the cover door structure.

<FIG> illustrates a cover member <NUM> of the second modified example. With the cover member <NUM>, a total of three cover doors are formed including cover doors 222a and 222b which open to the lower left and right and the cover door 202a which opens upward based on a tear line <NUM>. With the cover member <NUM> as well, similar to the cover member <NUM>, the cover door 202a opens at a point more to the front of the vehicle than the module installation surface <NUM> (see <FIG>), enabling reducing and dispersing the upward thrust force of the cushion <NUM> on the head <NUM> of the occupant <NUM>.

<FIG> illustrates a cover member <NUM> of the third modified example. The upper part of the cover member <NUM> is made up of two cover doors 242a and 242b that open to the left and right due to a tear line <NUM> and the lower part is made up of a cover door 242c that opens downward. With the cover member <NUM> as well, because the cover doors 242a and 242b include up to near the front end <NUM> of the upper region <NUM>, similar to the cover member <NUM> of <FIG>, upward thrust force of the cushion <NUM> on the head <NUM> of the occupant <NUM> can be reduced and dispersed, suppressing backward retroflexion of the head <NUM> and enabling improving the safety of the occupant <NUM> when activated.

<FIG> illustrates a cover member <NUM> of the fourth modified example. With the cover member <NUM>, a large part of the frontal region <NUM> and the upper region <NUM> are configured to open upward due to the tear line <NUM> as a single cover door <NUM>. With the cover member <NUM> as well, similar to the cover member <NUM>, the cover door <NUM> opens at a point more to the front of the vehicle than the module installation surface <NUM> (see <FIG>) enabling reducing and dispersing the upward thrust force of the cushion <NUM> on the head <NUM> of the occupant <NUM>.

<FIG> is a diagram illustrating a first modified example of the airbag module <NUM> in <FIG> (airbag module <NUM>). <FIG> illustrates the internal structure of the cushion <NUM> through each panel of the cushion <NUM>. Regarding the airbag module <NUM>, the cushion <NUM> is provided with a flow-regulating material <NUM> as an internal structure.

The flow-regulating material <NUM> is a member that guides the inflator <NUM> (see <FIG>) gas in a particular direction and is encapsulated in a bag shaped main bag <NUM> that makes up the outer surface of the cushion <NUM>. With the part including the gas outlet port <NUM> of the inflator <NUM> inserted into the main bag <NUM> covered, the flow-regulating material <NUM> is connected to the rear panel <NUM>. The flow-regulating material <NUM> includes side outlets 306a and 306b as well as a bottom outlet 306c as locations where the gas from the inflator <NUM> is discharged.

<FIG> is a diagram illustrating the flow-regulating material <NUM> in <FIG> from the side. The flow-regulating material <NUM> is formed in a bag shape by sewing, and a bottom outlet 306c is formed in an opening in the lower edge. The bottom outlet 306c is formed with a larger diameter than that of the side outlets 306a and 306b and more gas passes therethrough than the side outlets 306a and 306b. This causes the cushion <NUM> (see <FIG>) to expand and deploy preferentially from the lower part 104b. According to this configuration, the cushion <NUM> allows the lower part 104b to enter between the steering wheel <NUM> and the abdomen <NUM> of the occupant <NUM> at an early stage and to be sandwiched between the steering wheel <NUM> and the abdomen <NUM>.

<FIG> illustrates a state where the flow-regulating material <NUM> of <FIG> is unstitched and spread out on a plane. The flow-regulating material <NUM> is provided at the inlet port <NUM> where a part of the central inflator <NUM> (see <FIG>) is inserted and is secured together with the inflator <NUM> to the module installation surface <NUM> (see <FIG>).

<FIG> is a diagram illustrating the flow-regulating material <NUM> in <FIG> from various directions. <FIG> is a cross-sectional view of the flow-regulating material <NUM> along C-C in <FIG>. <FIG> schematically illustrates the upper part of the cover member <NUM> of <FIG>. The flow-regulating material <NUM> is made up of side outlets 306a and 306b and when viewing the frontal region <NUM> directly from the front, gas discharges diagonally upward to the left and right. This configuration enables efficient application of gas so that with respect to the cover member <NUM>, the cover doors 154a and 154b (see <FIG>) are opened to the left and right. In particular, the side outlets 306a and 306b are formed on a path connecting the inflator <NUM> and the tear line <NUM>. This configuration enables the tear line <NUM> of the cover member <NUM> to cleave efficiently.

<FIG> illustrates a state in which the cushion <NUM> is expanded using the flow-regulating material <NUM> in <FIG>. For the flow-regulating material <NUM> (see <FIG>), gas is discharged from the side outlets 306a and 306b but is not discharged directly upwards. Therefore, if the head <NUM> of a non-normal seating position occupant <NUM> (see <FIG>) is positioned above the steering wheel <NUM>, the cushion <NUM> expands to the left and right while enabling suppressing upward expansion pressure of the cushion <NUM>.

<FIG> is a cross-sectional view of the flow-regulating material <NUM> along D-D in <FIG>. The flow-regulating material <NUM> is set up so that when inflated, gas from the side outlets 306a and 306b flows out at an angle more towards the front of the vehicle than in the vehicle width direction. As illustrated in <FIG>, this configuration more readily enables dispersion of cushion <NUM> expansion pressure to the front of the vehicle in the case the occupant <NUM> is in a non-normal seating position.

<FIG> illustrates the flow-regulating material <NUM> and the steering wheel <NUM> in <FIG> as viewed from the left side in the vehicle width direction. With the flow-regulating material <NUM> in an expanded state, the side outlets 306a and 306b preferably discharge gas diagonally at a prescribed angle toward the front of the car, opposite the frontal region <NUM> (<FIG>). As illustrated in <FIG>, this configuration also more readily enables dispersion of the cushion <NUM> expansion pressure to the front of the vehicle in the case the occupant <NUM> is in a non-normal seating position.

Thus, the flow-regulating material enables efficient opening of the cover member <NUM> cover doors 154a and 154b to the left and right. Therefore, the flow-regulating material <NUM> enables suitably combining the cover member <NUM> (see <FIG>) having cover doors that open to the left and right and the cover member <NUM> (<FIG>). In addition, in applying the technical concept of the flow-regulating material <NUM>, implementing a flow-regulating material having a discharge port adapted to a tear line and cover door configuration of the cover member <NUM> (<FIG>), cover member <NUM> (<FIG>), or cover member <NUM> (<FIG>) is feasible.

<FIG> is a diagram illustrating a second modified example of the airbag module <NUM> in <FIG> (airbag module <NUM>). The airbag module <NUM> is provided with a flow-regulating material <NUM> as in the internal structure of the cushion <NUM>.

The flow-regulating material <NUM> is different from the flow-regulating material <NUM> of <FIG> in having an overall flat circular shape. Similar to the flow-regulating material <NUM>, the flow-regulating material <NUM> also has side outlets 306a and 306b and a bottom outlet 306c.

<FIG> illustrates a rear panel <NUM> of the flow-regulating material <NUM> of <FIG> unfolded on a flat surface. The rear panel <NUM> is provided with an insertion hole <NUM> in the center, notches are formed along the side outlets 306a and 306b and along the bottom outlet 306c on the left and right bottom edges and a notch is formed to make the flow-regulating material <NUM> round. <FIG> illustrates a front panel <NUM> of the flow-regulating material of <FIG> unfolded on a flat surface. The front panel <NUM> can be substantially circular and the flow-regulating material (see <FIG>) can be created by joining the edges to the rear panel <NUM> (<FIG>).

Thus, the flow-regulating material <NUM> also enables efficient opening of the cover member <NUM> cover doors 154a and 154b to the left and right. Therefore, the flow-regulating material <NUM> enables suitably combining the cover member <NUM> (see <FIG>) having cover doors that open to the left and right and the cover member <NUM> (<FIG>).

Preferred examples of the present invention were described above while referring to the attached drawings <NUM>-<NUM>. However, the embodiments described above are preferred examples 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.

Claim 1:
A driver seat airbag device, comprising a steering wheel (<NUM>) of a vehicle; and an airbag module (<NUM>) including an inflator (<NUM>) and an airbag cushion (<NUM>), the airbag module (<NUM>) being housed in the steering wheel (<NUM>), wherein
the steering wheel (<NUM>) comprises:
a variant rim (<NUM>) with upper center part thereof omitted;
a module installation surface (<NUM>) for installing the airbag module (<NUM>) provided in a center of the rim (<NUM>);
a cover member (<NUM>) covering the airbag module (<NUM>) installed on the module installation surface (<NUM>);
the cover member (<NUM>) comprises:
a frontal region (<NUM>) covering an occupant side of the airbag module (<NUM>);
an upper region (<NUM>) extending from the upper end of the frontal region (<NUM>) toward the front of the vehicle and covering the upper side of the airbag module (<NUM>); and
a tear line (<NUM>) provided in a groove shape on the airbag module side of the frontal region (<NUM>) and upper region (<NUM>), which cleaves open due to expansion pressure of the airbag cushion, and causes the frontal region (<NUM>) and upper region (<NUM>) to open as a plurality of cover doors;
the tear line (<NUM>) extends continuously from at least the center of the frontal region (<NUM>) to at least the center of the upper region (<NUM>), and
the plurality of cover doors includes a left cover door (154a) and a right cover door (154b) that open respectively from the center regions of the frontal region (<NUM>) and upper region (<NUM>) to the left and right,
characterized in thatthe tear line (<NUM>) extends from near the center of the frontal region (<NUM>) to a point near the center of the upper region (<NUM>) that is more forward on the vehicle than the module installation surface (<NUM>), such that
the cover doors (154a, 154b) are formed to include a region extending from the frontal region up to the point more toward the front of the vehicle than the module installation surface <NUM>), and
after cleaving of the cover member (<NUM>) an opening in the upper region (<NUM>) extends towards the front of the vehicle to a position beyond the module installation surface (<NUM>) by a distance (S1).