Patent Description:
Airbags are almost a standard fixture in vehicles of recent years. An airbag is a safety apparatus that operates during an emergency such as a vehicle collision, and inflates and deploys due to gas pressure so as to catch and thereby protect an occupant. There are various types of airbag, which vary according to installation location and application. For example, in order to protect a driver from a collision from a front-rear direction, a front airbag apparatus is provided in the centre of a steering wheel. Further, in order to protect an occupant from an impact from a vehicle width direction due to a side surface collision or the like, a curtain airbag apparatus is provided in the vicinity of a ceiling above a side window, a side airbag apparatus is provided in a side portion of a seat, and so on.

In many cases, the interior of a cushion is, in various airbag apparatuses, partitioned into a plurality of regions in consideration to the behaviour, occupant restraining force, and the like thereof during deployment. For example, the side airbag apparatus described in PTL <NUM> has a double structure in which an inner bag is provided inside an outer bag. In PTL <NUM>, the inner bag inflates to a high pressure so as to restrain a shoulder vicinity of an occupant, and the outer bag inflates to a low pressure so as to restrain a chest vicinity of the occupant.

The side airbag apparatus described in PTL <NUM> discloses an airbag according to the preamble of claim <NUM>.

With a configuration in which the interior of a cushion is partitioned by providing an inner bag as in PTL <NUM>, an amount used of fabric (base fabric) constituting the cushion increases. As the amount of base fabric used affects material costs when the cushion is mass produced, it is more effective to supress the amount of base fabric used to as little as possible. Further, in order to enable rapid inflation and deployment, it is necessary to realise a smooth flow of gas inside the cushion.

In view of such problems, an object of the present invention is to provide an airbag apparatus which allows an amount of base fabric used for a cushion to be suppressed and, further, enables gas to flow efficiently inside the cushion.

In order to solve the problem described above, an airbag apparatus according to the present invention has the technical features of claim <NUM>.

With the configuration of claim <NUM>, the interior of the cushion is partitioned by simply joining the base fabrics, hence there is no increase in the amount of base fabric used and material costs can be suppressed. Further, by realising a projecting vent using vent forming portions arranged in two rows at which the base fabrics are joined, a smooth flow of gas can be achieved using a simple configuration. It may also be supposed that that a vent portion could also be formed by, for example, simply providing an opening (an unsewn portion) midway along a boundary between the two chambers. However, depending on the way in which a force that acts on the base fabrics during inflation and deployment of the cushion is applied, it may be difficult for a force that acts in a direction so as to open the opening to be applied, such that a delay in gas flow could feasibly occur. However, with the projecting vent described above, a force acts on an inner side thereof as gas enters, hence, once gas has entered, the projecting vent does not close or collapse. Accordingly, the configuration described above enables a smooth flow of gas, whereby rapid inflation and deployment and occupant restraint can be achieved.

According to the invention, the projecting vent described above does also include a cylindrical portion in which the vent forming portions arranged in two rows extend towards a first chamber in parallel with each other. This configuration enables suitable realisation of a projecting vent that extends in a manner such that a diameter thereof is consistent.

The projecting vent described above may also include a first conical tube portion in which the vent forming portions arranged in two rows extend towards the first chamber while gradually separating from each other. This configuration enables realisation of a projecting vent that has a shape in which a diameter thereof gradually increases.

The projecting vent described above may also include a second conical tube portion in which the vent forming portions arranged in two rows extend towards the first chamber while gradually approaching closer to each other. This configuration enables realisation of a projecting vent that has a shape in which a diameter thereof gradually decreases.

The base fabric joint portion described above may also further include circular joint portions which close, in a circular shape, the respective ends of the vent forming portions arranged in two rows, and the projecting vent may also be formed by the vent forming portions arranged in two rows and the circular joint portions. As a load may be concentrated in the vicinity of the ends of the vent forming portions, the load is dispersed by providing the circular joint portions, whereby breakage, etc., of the base fabrics can be prevented.

According to the invention, the cushion described above is configured such that the cushion described above is for a side airbag which inflates and deploys at a side of an occupant in a vehicle seat, a second chamber of the two chambers is a rear chamber that houses the inflator and the first chamber is a front chamber that inflates and deploys at least towards the vehicle front side of the rear chamber, and the projecting vent extends from the opening to the interior of the front chamber. This configuration allows gas to flow smoothly from the rear chamber to the front chamber, enabling rapid inflation and deployment thereof.

According to an embodiment not belonging to the invention, the cushion described above may be configured such that the cushion described above is for a side airbag which inflates and deploys at a side of an occupant in a vehicle seat, the first chamber is a rear chamber that houses the inflator and the second chamber of the two chambers is a front chamber that inflates and deploys at least towards the vehicle front side of the rear chamber, and the projecting vent extends from the opening to the interior of the rear chamber. This configuration also allows gas to flow smoothly from the rear chamber to the front chamber, enabling rapid inflation and deployment thereof.

Inflation and deployment of the front chamber described above may also be completed later than inflation and deployment of the rear chamber. When the airbag apparatus is used as a side airbag, initially, the rear chamber located immediately beside the occupant is filled with gas in an efficient manner, after which the front chamber, which inflates and deploys over a wide area towards the front of the vehicle, is filled with gas. This configuration allows the cushion to be inflated and deployed rapidly while demonstrating more stable deployment behaviour, enabling early-stage restraint of the occupant to be achieved.

With the present invention, an airbag apparatus can be provided which allows an amount of base fabric used for a cushion to be suppressed and, further, enables gas to flow efficiently inside the cushion.

Preferred embodiments of the present invention will be described hereinafter in detail with reference to the accompanying drawings. Dimensions, materials, other specific numerical values, and the like disclosed in the embodiments are merely examples to facilitate understanding of the invention and, unless indicated otherwise, do not limit the present invention. Note that, in this description and in the drawings, elements which have a substantially similar function or configuration will be denoted by identical reference numerals, thereby eliminating redundant explanations, and elements that are not directly related to the present invention will be omitted.

<FIG> is a diagram illustrating a side airbag apparatus <NUM> according to a first embodiment of the present invention. In <FIG>, the side airbag apparatus <NUM> and a vehicle right side seat <NUM> to which the side airbag apparatus <NUM> is applied are illustrated from an inner side thereof in a vehicle width direction. As illustrated in <FIG>, in the side airbag apparatus <NUM>, a cushion <NUM> is configured to inflate and deploy at a side of the seat <NUM>.

The cushion <NUM> is a bag-shaped part that catches an occupant during an emergency such as when an impact occurs in the vehicle, and inflates and deploys in a flat shape between the occupant and a side door. The cushion <NUM> is formed in a bag shape by sewing or adhering together a plurality of base fabrics that have been layered one on top of the other. In the present embodiment, the cushion <NUM> is realised by using a vehicle outer side main panel 108a (see <FIG>) and a vehicle inner side main panel 108b as base fabrics, and sewing these base fabrics together in a bag shape. The cushion <NUM> is wound or folded so as to be housed in a housing (not shown) provided in a side portion of a seat back <NUM>. The housed-state cushion <NUM> is invisible from the outside due to being covered by a seat cover or the like from above. During operation of the side airbag <NUM>, the cushion <NUM> rips open the seat cover or the like and inflates and deploys towards the side of the occupant so as to restrain the occupant from the side.

An inflator <NUM> is installed together with the cushion <NUM> in the side portion of the seat back <NUM>. The inflator <NUM> is a gas generating device, which receives an operation signal transmitted from a vehicle side when an impact occurs and supplies gas to the interior of the cushion <NUM>. The inflator <NUM> adopted in the present embodiment is of a cylinder type (cylindrical type), and is enclosed and installed in the cushion <NUM> so that a longitudinal direction thereof is vertically oriented. A stud bolt (not shown) integrated with the surface of the inflator <NUM> is exposed from the interior of the cushion <NUM> to the outside thereof and fastened to the housing provided in the side portion of the seat back <NUM> or the like.

Inflators popular at present include a type that is filled with a gas generating agent and generates gas by causing combustion thereof, a type which is filled with compressed gas and supplies the gas without generating heat, a hybrid type which uses both combustive gas and compressed gas, and so on. Any of these types of inflator can be used as the inflator <NUM>.

<FIG> is a diagram illustrating the cushion <NUM> shown in <FIG> as observed from an inner side thereof in the vehicle width direction. <FIG> illustrates a dummy which represents an occupant <NUM>. The interior of the cushion <NUM> of the present embodiment is partitioned into two chambers. As illustrated in <FIG>, in the cushion <NUM>, a rear chamber <NUM> is provided in a lower area on a vehicle rear side as a first chamber, and a front chamber <NUM> is provided on a vehicle front side and a vehicle upper side of the rear chamber <NUM> as a second chamber. The inflator <NUM> is enclosed and installed in the rear chamber <NUM>.

The rear chamber <NUM> inflates and deploys mainly in the immediate vicinity of a shoulder E1, a chest, and the like of the occupant <NUM> so as to restrain the shoulder E1, the chest, and the like of the occupant <NUM>. An intermediate restraining member <NUM> which has a shape that curves and projects towards the front of the vehicle is provided at the top of the rear chamber <NUM>. The intermediate restraining member <NUM> is capable of efficiently restraining the vicinity of the shoulder E1 of the occupant <NUM>.

The front chamber <NUM> has a larger gas capacity than the rear chamber <NUM> and inflates and deploys widely from the rear chamber <NUM> towards the front of the vehicle and the top of the vehicle. The front chamber <NUM> widely restrains the head E2, the arm E3, and so on of the occupant <NUM> so as to achieve secure protection of the occupant <NUM>.

<FIG> is a perspective view illustrating the cushion <NUM> shown in <FIG>. In <FIG>, a portion of the vehicle inner side main panel 108a of the vehicle inner side main panel 108a and the vehicle outer side main panel 108b which constitute the surface of the cushion <NUM> has been omitted in order to illustrate an internal configuration. As illustrated in <FIG>, the cushion <NUM> is provided with a base fabric joint portion <NUM> which partitions the internal space thereof into two chambers, i.e. the rear chamber <NUM> and the front chamber <NUM>.

The base fabric joint portion <NUM> joins the main panel 108a and the main panel 108b in a linear manner by sewing and welding or bonding, making it impossible for gas to pass therethrough. Most of the base fabric joint portion <NUM> is provided along a boundary between the rear chamber <NUM> and the front chamber <NUM>. The base fabric joint portion <NUM> includes an upper joint portion 120a which is located on an upper side with respect to a projecting vent <NUM>, which will be described later, and a lower joint portion 120b which is located on a lower side with respect to the projecting vent <NUM>. As an alternative method of partitioning the cushion <NUM>, there also exists a method of partitioning by means of a part called a baffle, which is provided by using, for example, base fabric. However, in comparison to this method, the interior of the cushion <NUM> of the present embodiment is partitioned using only the base fabric joint portion <NUM>, hence there is no increase in the amount of materials such as base fabric used and material costs can be suppressed.

Gas is supplied from the rear chamber <NUM> to the front chamber <NUM> through the projecting vent <NUM>. The projecting vent <NUM> projects so as to extend from the rear chamber <NUM>, i.e. the second chamber of the two chambers to the interior of the front chamber <NUM>, i.e. the first chamber of the two chambers and inflates and deploys in a cylindrical shape so as to allow gas to flow between the two chambers. The projecting vent <NUM> is provided by means of an opening <NUM> which is provided between the upper joint portion 120a and the lower joint portion 120b, and two vent forming portions 125a and 125b, which extend together from both ends of the opening <NUM> towards a side of the front chamber <NUM> as portions of the base fabric joint portion.

The opening <NUM> is an area in which the base fabrics are not joined, and is provided midway along the base fabric joint portion <NUM> which forms the boundary between the rear chamber <NUM> and the front chamber <NUM>. The vent forming portions 125a and 125b are portions arranged in two rows, i.e. an upper row and a lower row, which form the projecting vent <NUM> in the base fabric joint portion <NUM>, and include the vent forming portion 125a on an upper side of the opening <NUM> and the vent forming portion 125b on a lower side of the opening <NUM>. With such a configuration, the projecting vent <NUM>, which extends from the opening <NUM> to the interior of the front chamber <NUM>, is formed when the cushion <NUM> inflates and deploys. The vent forming portions 125a and 125b, which are arranged in two rows, extend towards the front chamber <NUM> side in parallel with each other and form a cylindrical portion <NUM> in the projecting vent <NUM>. The cylindrical portion <NUM> is a part that extends in a manner such that a diameter thereof is consistent, and occupies the main portion of the projecting vent <NUM> of the present embodiment.

Circular joint portions 126a and 126b are provided at respective ends of the vent forming portions 125a and 125b. The circular joint portions 126a and 126b close the respective ends of the vent forming portions 125a and 125b in a circular shape. Although there is a tendency for a load to be concentrated in the vicinity of the ends of the vent forming portions 125a and 125b, the load can be dispersed by providing the circular joint portions 126a and 126b, whereby breakage (bursting) and the like of the base fabrics is prevented.

<FIG> is a diagram illustrating a process of inflation and deployment of the cushion <NUM> shown in Fig. <NUM>(a). As illustrated in <FIG>, when the inflator <NUM> operates, initially, the rear chamber <NUM> begins to inflate and deploy. <FIG> illustrates a state in which further gas is supplied from the inflator <NUM> shown in <FIG>. Gas is also supplied to the front chamber <NUM> from the rear chamber <NUM> through the projecting vent <NUM>. More specifically, a portion of the gas supplied to the rear chamber <NUM> flows into the front chamber <NUM> while causing the projecting vent <NUM> to inflate and deploy.

<FIG> is a diagram illustrating the process of inflation and deployment of the cushion <NUM> subsequent to <FIG>. When inflation and deployment of the rear chamber <NUM> have been completed, the front chamber <NUM> is also filled with gas, and inflation and deployment thereof are completed following a slight delay. In this way, in the present embodiment, inflation and deployment of the front chamber <NUM> are completed slightly later than inflation and deployment of the rear chamber <NUM> due to the gas flowing into the front chamber <NUM> via the projecting vent <NUM> only.

In the side airbag apparatus <NUM>, the rear chamber <NUM> located immediately beside the occupant is initially filled with gas in an efficient manner, after which the front chamber <NUM>, which inflates and deploys over a wide area towards the front of the vehicle, is filled with gas. This configuration allows early-stage restraint of the occupant to be achieved.

As described above, the front chamber <NUM> is a so-called delay chamber, inflation and deployment of which are completed slightly later than in the rear chamber <NUM>. By causing the front chamber <NUM> to function as a delay chamber, it is also possible to reduce the potential for harm to an occupant that is present, for example, in an unexpected (i.e. out-of-position) posture that differs from the regular seated state. For example, when an occupant is present near a vehicle outer side of the seat, the occupant is positioned at a vehicle front side of the cushion <NUM>, such that the cushion <NUM> comes into contact with the occupant in a linear manner. However, as the front chamber <NUM> is a delay chamber, the rigidity of the front chamber <NUM> is slightly suppressed immediately after operation of the inflator <NUM>, such that a load input towards the out-of-position occupant can be reduced. Further, by setting the front chamber <NUM> as a delay chamber, the occupant having been shaken back into position due to inertia can be restrained at a more appropriate timing, particularly when the side airbag apparatus <NUM> is, in a side collision or the like, provided on a side opposite to the collision as viewed from the occupant (a regular far side airbag).

In the present embodiment, the projecting vent <NUM> allows a smooth flow of gas to be maintained. <FIG> is a diagram comparing the cushion <NUM> shown in <FIG> and a cushion <NUM> of a comparative example. <FIG> is a cross-sectional view taken along the A-A line of the cushion <NUM> shown in <FIG>. As illustrated in <FIG>, the projecting vent <NUM> has a predetermined length which extends in a cylindrical shape, and a force acts thereon from an inner side thereof as gas enters, hence, once gas has entered, the projecting vent <NUM> does not close or collapse.

The cushion <NUM> illustrated in <FIG> is a comparative example of the cushion <NUM> shown in <FIG>, in which the projecting vent <NUM> has been omitted. In the cushion <NUM>, the vent portion <NUM> is realised by simply providing an opening (an unsewn portion) between an upper joint portion 12a and a lower joint portion 12b. <FIG> is a cross-sectional view taken along the B-B line shown in <FIG>. As illustrated in <FIG>, in the vent portion <NUM>, constriction occurs in the main panels 108a and 108b of the cushion <NUM>. This is because, as illustrated in <FIG>, the main panels 108a and 108b are sewn together above and below the vent portion <NUM>, such that there is limitation in terms of the size to which the vent portion <NUM> can inflate in comparison to the rear chamber <NUM> and the front chamber <NUM>.

<FIG> illustrates an ideal state of inflation and deployment of the cushion <NUM>, however, as shown in <FIG>, a phenomenon in which gas flow is hindered may occur in the cushion <NUM>. When the rear chamber <NUM> shown in <FIG> is inflated and deployed, for example, a force which acts in a vertical direction is applied to the rear chamber <NUM> by the gas. In such a case, the vent portion <NUM> is also pulled in the vertical direction. When this happens, areas of the main panels 108a and 108b in the vicinity of the vent portion <NUM> may be subjected to forces 16a and 16b, which act in a direction so as to close the vent portion <NUM>, as illustrated in <FIG>. In such a case, the vent portion <NUM> narrows and gas flow is hindered such that supply of gas to the front chamber <NUM> may be delayed.

Unlike the vent portion <NUM> shown in <FIG>, the projecting vent <NUM>, which has a predetermined length, illustrated in <FIG> is capable of receiving gas pressure in an efficient manner from an inner side thereof. For this reason, once gas has entered, the projecting vent <NUM> inflates to a cylindrical shape, and does not close or collapse thereafter. Accordingly, the cushion <NUM> of the present embodiment enables a smooth flow of gas, whereby rapid inflation and deployment and occupant restraint can be achieved.

<FIG> and <FIG> are diagrams illustrating modified examples of the cushion <NUM> shown in <FIG>, the example in <FIG> not belonging to the invention. In <FIG> and <FIG>, previously described constituent elements are denoted by the same reference numerals, thereby eliminating description thereof. Moreover, constituent elements having the same name as a previously described constituent element embody the same function as the previously described constituent element, even where reference signs differ therebetween.

Unlike the cushion <NUM> shown in <FIG>, a cushion <NUM> of the first modified example not belonging to the invention illustrated in <FIG> has a projecting vent <NUM> that projects so as to extend from the opening <NUM> to the interior of the rear chamber <NUM>. Specifically, vent forming portions 204a and 204b, which form the projecting vent <NUM>, extend from both ends of the opening <NUM> to the interior of the rear chamber <NUM>, and the projecting vent <NUM> projects from a side of the front chamber <NUM>, i.e. the second chamber of the two chambers, to a side of the rear chamber <NUM>, i.e. the first chamber of the two chambers. The projecting vent <NUM> also inflates to a cylindrical shape once gas has entered, and does not close or collapse thereafter. Accordingly, the projecting vent <NUM> also allows gas to flow smoothly from the rear chamber <NUM> to the front chamber <NUM>, which contributes to rapid inflation and deployment, etc., of the cushion <NUM>.

A cushion <NUM> of a second modified example not belonging to the invention shown in <FIG> is also provided with a projecting vent <NUM> that projects from the front chamber <NUM> side to the interior of the rear chamber <NUM>. In the cushion <NUM>, upper and lower vent forming portions 224a and 224b, which form the projecting vent <NUM>, are not parallel, but instead extend obliquely towards the interior of the rear chamber <NUM> so as to gradually separate from each other. Accordingly, the projecting vent <NUM> has a configuration in which a mouth serving as a gas inlet on the rear chamber <NUM> side is widened. With the projecting vent <NUM>, gas can be sent towards the front chamber <NUM> more efficiently in comparison to the projecting vent <NUM> shown in <FIG>.

A cushion <NUM> of a third modified example illustrated in <FIG> is provided with a projecting vent <NUM> that projects so as to extend from the opening <NUM> to the interior of the front chamber <NUM>. In the cushion <NUM>, an upper vent forming portion 246a and a lower vent forming portion 246b, which are arranged in two rows and form the projecting vent <NUM>, extend from the opening <NUM> to the front chamber <NUM> side in parallel with each other and, thereafter, extend while gradually separating from each other. As a result, the projecting vent <NUM> has a cylindrical portion <NUM> that extends in a manner such that a diameter thereof is consistent and a first conical tube portion <NUM> that has a shape which gradually increases in diameter, and has a shape in which a diameter thereof is larger on a distal side. The projecting vent <NUM> also enables gas to be sent efficiently from the rear chamber <NUM> towards the front chamber <NUM>.

A cushion <NUM> of the third modified example illustrated in <FIG> is provided with a projecting vent <NUM> that projects so as to extend from the opening <NUM> to the interior of the front chamber <NUM>. In the cushion <NUM>, an upper vent forming portion 266a and a lower vent forming portion 266b, which are arranged in two rows and form the projecting vent <NUM>, extend from the opening <NUM> to the front chamber <NUM> side while gradually getting closer to each other and, thereafter, extend in parallel with each other. As a result, the projecting vent <NUM> has a second conical tube portion <NUM> that has a shape which gradually decreases in diameter and a cylindrical portion <NUM> that extends in a manner such that a diameter thereof is consistent, and has a tapered shape in which a proximal side thereof has a larger diameter. The projecting vent <NUM> also enables gas to be sent efficiently from the rear chamber <NUM> towards the front chamber <NUM>.

Note that, although implemented in a side air bag in the above description, the technical concept of the present invention can also be implemented in a curtain air bag or in a knee air bag. As the interior of a cushion for a curtain airbag is, in general, partitioned into a plurality of chambers, the base fabric joint portion <NUM> described above can be applied thereto so as to partition the cushion into chambers and provide the projecting vent <NUM> therebetween. As a cushion for a knee airbag is also, similarly to that for a side airbag, flat and has an interior that is partitioned into a plurality of chambers, the base fabric joint portion <NUM> and the projecting vent <NUM> described above can be suitably implemented therein. A smooth supply of gas, as well as rapid inflation and deployment and occupant restraint can thus be achieved with a simple configuration in any of these types of air bag apparatus in the same way as in the side airbag apparatus <NUM> described above.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the embodiments described above are preferred examples of the present invention, and other embodiments can also be implemented or executed by various methods. Unless specifically indicated otherwise in the description of the present application, the present invention is not limited to the shapes, sizes of the detailed components shown in the accompanying drawings. Further, the expressions and terms used in the description of the present application are for explanatory purposes and, unless specifically indicated otherwise, are not limited thereto.

Accordingly, it would be obvious to a person skilled in the art that various modifications or amendments could be conceived within the scope of the claims, and a person skilled in the art would appreciate that such modifications or amendments naturally fall within the technical scope of the present invention.

Claim 1:
An airbag apparatus comprising:
an inflator (<NUM>) which supplies gas;
a cushion (<NUM>) in which base fabrics including at least a vehicle outer side panel (108b) and a vehicle inner side panel (108a) are formed into a bag shape, and which inflates and deploys due to the gas so as to protect an occupant (<NUM>) during a vehicle emergency;
a base fabric joint portion (<NUM>) at which the vehicle outer side panel (108b) and the vehicle inner side panel (108a) of the cushion (<NUM>) are joined, and which partitions the cushion (<NUM>) into at least two chambers; and
an opening (<NUM>) which is provided midway along the base fabric joint portion (<NUM>) and at which the base fabrics are not joined, characterized in that
the base fabric joint portion (<NUM>) includes vent forming portions arranged in two rows which extend together from both ends of the opening (<NUM>) towards a first chamber of two chambers and form a projecting vent (<NUM>) that projects from the opening (<NUM>) to the first chamber, and
the projecting vent (<NUM>) inflates and deploys during operation of the inflator (<NUM>) so as to flow the gas between the two chambers, wherein
the projecting vent (<NUM>) includes a cylindrical portion in which the vent forming portions arranged in two rows extend towards the first chamber in parallel with each other, wherein
the cushion (<NUM>) is for a side airbag which inflates and deploys at a side of an occupant (<NUM>) in a vehicle seat (<NUM>),
a second chamber of the two chambers (<NUM>) is a rear chamber that houses the inflator (<NUM>) and the first chamber (<NUM>) is a front chamber that inflates and deploys at least on a vehicle front side of the rear chamber (<NUM>), and
the projecting vent (<NUM>) extends from the opening (<NUM>) to an interior of the front chamber.