Airbag device

An airbag device includes a movement obtaining unit, an airbag, and an airbag controller. The movement obtaining unit is configured to obtain a movement of an occupant in an automobile. The airbag is deployable with different thicknesses into a gap between the occupant and a side portion of the automobile. The airbag controller is configured to restrict the thickness of the airbag that deploys toward the gap so that the airbag is inserted into the gap, if the airbag controller determines that the gap is smaller than a predetermined value on the basis of the movement of the occupant obtained by the movement obtaining unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Japanese Patent Application No. 2017-070368 filed on Mar. 31, 2017, the entire contents of which are hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present invention relates to an airbag device, specifically, to an airbag device that deploys an airbag between a side portion of an automobile and an occupant.

2. Related Art

There is an airbag device that deploys an airbag between a side portion of an automobile and an occupant to protect the occupant from impact of a collision of the automobile. For example, a side airbag deployable toward the front of an automobile along a side portion of the automobile is disposed in a side portion of a seat. By deploying the side airbag, it is possible to receive an occupant shifted toward the side of the automobile due to a collision and to absorb impact of the collision.

However, such a side airbag deploys so as to project considerably toward the front from the seat of the automobile, and thus the deployment location of the side airbag may become displaced.

As a technology that suppresses a displacement in a deployment location of a side airbag, for example, Japanese Unexamined Patent Application Publication (JP-A) No. 2006-82664 proposes a side-airbag device that suitably controls the deployment-expansion location of a side airbag. The side-airbag device includes a main deployable portion that deploys around the side of the chest of an occupant and a sub deployable portion that deploys around the side of the head or the side of the waist of the occupant. The sub deployable portion has an inner surface on which a pocket having an opening is disposed. The opening faces a gas generating source disposed inside the main deployable portion. Thus, when the main deployable portion deploys, the pressure of a deployment gas is applied into the pocket and enables the side airbag to easily deploy toward the vehicle upper side or the vehicle lower side, that is, in a direction deeper into the pocket, thereby suppressing a displacement of the deployment location of the side airbag.

However, because the side-airbag device in JP-A No. 2006-82664 deploys the side airbag in the vehicle up-down direction in order to control the deployment location of the side airbag, the side-airbag device has a drawback in which deployment toward the front is delayed. Therefore, it may become impossible for the side airbag to deploy at a predetermined location by, for example, coming into contact, in process of the deployment, with an occupant shifted toward a side portion of an automobile due to a collision. In particular, in an autonomously operated automobile, an occupant is shifted toward a side portion of the automobile at a high velocity and thus may reach an airbag deployment path before an airbag reaches the path. As a result, it may become impossible to deploy the airbag between the occupant and the side portion of the automobile and to receive the occupant by the air bag.

SUMMARY OF THE INVENTION

To address such a drawback in the related art, it is desirable to provide an airbag device that ensures reception of an occupant by an airbag.

An aspect of the present invention provides an airbag device including a movement obtaining unit that is configured to obtain a movement of an occupant in an automobile; an airbag that is deployable with different thicknesses into a gap between the occupant and a side portion of the automobile; and an airbag controller that is configured to restrict a thickness of the airbag that deploys toward the gap so that the airbag is inserted into the gap, if the airbag controller determines that the gap is smaller than a predetermined value on the basis of the movement of the occupant obtained by the movement obtaining unit.

DETAILED DESCRIPTION

Examples of the present invention will be described below on the basis of the attached drawings.

FIRST EXAMPLE

FIG. 1illustrates the structure of an automobile that includes an airbag device according to a first example of the present invention. The automobile is autonomously operable and includes an operation controller1that controls autonomous operation, a seat2disposed inside a passenger compartment, a seat belt3disposed at the seat2, and an airbag device4coupled to the operation controller1.

The operation controller1controls the autonomous operation of the automobile on the basis of pre-stored map data and a current position of the automobile. The operation controller1controls, for example, braking and steering of the automobile. The autonomous operation is not limited to operation that completely controls automobile operation. The autonomous operation includes an operation support system that supports an occupant D in a part of automobile operation.

The seat belt3is a three-point seat belt, which secures the shoulders and waist of the occupant D sitting in the seat2.

The airbag device4includes a housing5disposed in a side portion of the seat2, an airbag6stored in the housing5, and an inflator7disposed in the housing5.

The airbag6is a side airbag that is disposed in the seat2and deployable toward the vehicle front side along a side portion of the automobile. The airbag6is deployable with thicknesses different in the vehicle width direction, into a gap between the occupant D and the side portion of the automobile.

The inflator7is used to deploy the airbag6.

Next, the structure of the airbag device4will be described in detail.

As illustrated inFIG. 2, the airbag device4includes a movement obtaining unit8coupled to the operation controller1. An airbag controller9is coupled to the movement obtaining unit8. The airbag controller9is coupled to each of the inflator7and a tether cutting member10. The airbag6includes inner tethers11disposed therein.

Each inner tether11is disposed inside the airbag6so as to extend in the vehicle width direction of the automobile. One end of each inner tether11is secured to the airbag6on the side of a side portion12of the automobile and another end thereof is secured to the airbag6on the side of the seat2. The thus secured inner tethers11restrict the deployment thickness of the airbag6in the vehicle width direction to deploy the airbag6with a thickness that is smaller by a predetermined degree.

The tether cutting member10is used to cut the inner tethers11to thereby cause the airbag6to deploy larger in the vehicle width direction, in other words, to thereby increase the thickness of the airbag6.

The movement obtaining unit8obtains the movement of the occupant D. Specifically, the movement obtaining unit8obtains the movement of the automobile on the basis of control information of the operation controller1and calculates the movement of the occupant D on the basis of the obtained movement of the automobile.

The airbag controller9calculates the gap S between the occupant D and the side portion12of the automobile on the basis of the movement (shift), which is obtained by the movement obtaining unit8, of the occupant D toward the side portion12. If the airbag controller9determines that the gap S is smaller than a predetermined value, the airbag controller9restricts the thickness in the vehicle width direction of the airbag6that deploys toward the gap S, so that the airbag6is inserted into the gap S. Specifically, the airbag controller9deploys the airbag6with one of different thicknesses by controlling the tether cutting member10. If the airbag controller9determines that the gap S is smaller than the predetermined value, the airbag controller9deploys, without driving the tether cutting member10, the airbag6with a thickness that is smaller by a predetermined degree. In contrast, as illustrated inFIG. 3, if the airbag controller9determines that the gap S calculated on the basis of the movement, which is obtained by the movement obtaining unit8, of the occupant D toward the side portion12of the automobile is larger than or equal to the predetermined value, the airbag controller9cuts the inner tethers11by using the tether cutting member10to cancel restriction of the thickness of the airbag6that deploys toward the gap S and deploy the airbag6with a normal thickness.

Next, operation in the first example will be described.

First, as illustrated inFIG. 1, the automobile with the occupant D sitting in the seat2is autonomously operated by the operation controller1. During autonomous operation, the operation controller1sequentially outputs a movement amount of the automobile, for example, a degree of steering of the automobile to the movement obtaining unit8of the airbag device4. Upon receiving the degree of steering of the automobile from the operation controller1, the movement obtaining unit8calculates the movement of the occupant D on the basis of the degree of steering. Preferably, the movement obtaining unit8obtains a degree of braking of the automobile, in addition to the degree of steering, from the operation controller1. In this case, it is possible to calculate the movement of the occupant D with high accuracy.

If a collision of the automobile occurs, the impact of the collision is detected by a collision detector (not shown), and a signal of the collision is received by the airbag controller9(FIG. 2). Upon receiving the collision signal, the airbag controller9obtains the movement of the occupant D from the movement obtaining unit8.

The airbag controller9then calculates the gap S between the occupant D and the side portion12on the basis of the velocity of the movement of the occupant D obtained from the movement obtaining unit8. The movement of the occupant D is, for example, the movement of the occupant D toward the side portion12of the automobile. If the airbag controller9determines that the gap S is smaller than a predetermined value, the airbag controller9injects a deployment gas into the airbag6from the inflator7, without driving the tether cutting member10, to deploy the airbag6toward the front.

For example, upon receiving, from the movement obtaining unit8, the movement of the occupant D in autonomous operation in which steering and braking are simultaneously performed, the airbag controller9determines that the gap S is small and deploys the airbag6without driving the tether cutting member10.

Here, when the automobile is manually operated, it is difficult to perform braking and steering at maximum capacity of the automobile. However, when the automobile is autonomously operated by the operation controller1, the braking and steering at the maximum capacity of the automobile are possible. Therefore, both the movement of the automobile and the acceleration of the occupant D are larger in autonomous operation compared with manual operation. As a result, the gap S may rapidly become smaller. In that case, if the thickness of the airbag6is not restricted and the airbag6is deployed with the normal thickness, the airbag6comes into contact with the occupant D and becomes impossible to deploy at a predetermined location. Moreover, if the occupant D is shifted so as to close the gap S before the deployment of the airbag6, the airbag6becomes impossible to deploy between the occupant D and the side portion12of the automobile. As a result, the occupant D may not be received by the airbag.

Considering the above circumstance, the thickness in the vehicle width direction of the airbag6is restricted by the inner tethers11, and the airbag6is deployed toward the front with a thickness that is smaller by the predetermined degree than in a case where the airbag6does not have the inner tethers11. The length of each inner tether11is pre-adjusted so that the airbag6is inserted into the gap S, on the basis of a value of the gap S that is calculated based on that the movement of the occupant D is rapid. Thus, the airbag6, whose thickness is restricted by the inner tethers11, starts deployment toward the gap S with a thickness that enables insertion of the airbag6into the gap S.

As described above, if the gap S rapidly becomes smaller due to the rapid movement of the occupant D, the airbag6starts deployment with a thickness smaller than the gap S. Therefore, it is possible to insert the airbag6smoothly into the gap S while the airbag6deploys and to ensure the deployment of the airbag6between the occupant D and the side portion12of the automobile. Moreover, the deployment of the airbag6with the restricted thickness achieves an increase in deployment speed. The increase in the deployment speed enables the airbag6to receive, without fail, the occupant D that is shifted toward the side portion12of the automobile at a high velocity due to a collision.

When being deployed, the airbag6is restricted by a plurality of the inner tethers11so as to have a thickness that is substantially uniform overall. Therefore, partial contact of the airbag6with the occupant D is suppressed, which enables smooth insertion of the airbag6into the gap S.

The airbag controller9preferably controls the thickness of the airbag6such that the thickness is increased after the airbag6has been inserted into the gap S, as illustrated inFIG. 4. Specifically, the airbag controller9drives the tether cutting member10to cut the inner tethers11while injecting the deployment gas from the inflator7into the airbag6. As a result of the cutting of the inner tethers11, restriction of the thickness of the airbag6is cancelled, which causes the airbag6to deploy such that the thickness thereof is increased with the injection of the deployment gas.

As described above, the airbag6is deployed such that the thickness is increased after the airbag6has been inserted into the gap S, which ensures reception of the occupant D and absorption of the collision impact on the occupant D.

If a collision of the automobile occurs, the airbag controller9receives, from the movement obtaining unit8, the movement of the occupant D toward the side portion12of the automobile. As illustrated inFIG. 3, if the received movement of the occupant D is slow and thus the airbag controller9determines that the gap S is larger than or equal to the predetermined value, the airbag controller9drives the tether cutting member10to cut the inner tethers11and injects the deployment gas from the inflator7into the airbag6to deploy the airbag6. The airbag6, without thickness restriction by the inner tethers11, starts deployment with a larger thickness. The thickness of the airbag6is pre-adjusted to ensure absorption of collision impact on the occupant D. Therefore, when the airbag6does not become into contact with the occupant D while deploying toward the gap S, the airbag6is deployed without thickness restriction to ensure absorption of the collision impact on the occupant D.

According to the first example, the airbag controller9restricts the thickness of the airbag6that deploys toward the gap S so that the airbag6is inserted into the gap S, if the airbag controller9determines that the gap S between the occupant D and the side portion12of the automobile is smaller than the predetermined value on the basis of the movement of the occupant D. Therefore, it is possible to ensure the reception of the occupant D by the airbag6.

SECOND EXAMPLE

The movement obtaining unit8of the first example calculates the movement of the occupant D on the basis of the control information of the operation controller1; however, the movement of the occupant D may be obtained by any other methods.

For example, a movement obtaining unit21, as an alternative to the movement obtaining unit8of the first example, may be disposed, and an external environment measuring unit22may be additionally coupled to the movement obtaining unit21, as illustrated inFIG. 5.

The external environment measuring unit22measures the external environment in which the automobile travels. The external environment measuring unit22may be, for example, a camera.

The movement obtaining unit21receives external environmental information measured by the external environment measuring unit22. The movement obtaining unit21receives the control information from the operation controller1, as is in the first example. The movement obtaining unit21estimates the movement of the occupant D on the basis of the external environmental information received from the external environment measuring unit22and the control information received from the operation controller1.

For example, if the external environment measuring unit22detects an obstacle present in front of the automobile, the movement obtaining unit21determines whether the automobile will collide with the obstacle, on the basis of the control information of the operation controller1. If it is determined that the automobile will collide with the obstacle, the movement obtaining unit21calculates an amount of collision impact to be applied to the automobile, on the basis of the external environmental information and the control information. The movement obtaining unit8then estimates the movement of the occupant D sitting in the seat2on the basis of the calculated amount of the impact to be applied to the automobile.

Then, the airbag controller9calculates the gap S on the basis of the movement of the occupant D estimated by the movement obtaining unit21and controls the thickness of the airbag6that deploys toward the gap S.

According to the second example, the thickness of the airbag6that deploys toward the gap S is controlled on the basis of the movement of the occupant D estimated by the movement obtaining unit21. Thus, it is possible to deploy the airbag6at an early stage and to insert the airbag6into the gap S, which ensures reception of the occupant D by the airbag6.

THIRD EXAMPLE

The movement obtaining unit of each of the first and second examples may obtain measurement information obtained by measuring the movement of the occupant D in the automobile.

For example, an occupant movement measuring unit31, as an alternative to the operation controller1of the first example, may be coupled to the movement obtaining unit8, as illustrated inFIG. 6.

The occupant movement measuring unit31directly measures the movement of the occupant D in the automobile. The occupant movement measuring unit31may be, for example, a camera.

The movement obtaining unit8calculates the movement of the occupant D toward the side portion12of the automobile on the basis of the measurement information obtained by the occupant movement measuring unit31.

The airbag controller9calculates the gap S on the basis of the movement of the occupant D calculated by the movement obtaining unit8and controls the thickness of the airbag6that deploys toward the gap S.

According to the third example, it is possible for the movement obtaining unit8to calculate the movement of the occupant D toward the side portion12with high accuracy because the occupant movement measuring unit31directly measures the movement of the occupant D. Therefore, the deployment thickness of the airbag6can be appropriately controlled.

In each of the aforementioned first to third examples, the airbag6is deployable with two different thicknesses. However, the number of the different thicknesses is not limited to two provided that the airbag6is deployable with different thicknesses. For example, the airbag controller9may perform stepwise control such that the airbag6has one of different thicknesses according to the movement of the occupant D. In other words, the airbag controller9sets a plurality of values in a stepwise manner in accordance with the velocity of the movement of the occupant D and deploys the airbag6with a thickness in accordance with the set value. Therefore, it is possible to deploy the airbag6with a maximal size and to receive the occupant D more safely.

In each of the aforementioned first to third examples, the airbag6is restricted by the plurality of inner tethers11, immediately after starting deployment to be inserted into the gap S, so as to have a thickness that is substantially even overall; however, thickness restriction is not limited thereto provided that the thickness is restricted such that the airbag6is inserted into the gap S.

For example, the airbag6may be restricted to have a smaller thickness at a portion close to a leading end portion that is at the foremost position when the airbag6is deployed. Therefore, it is possible to insert the airbag6into the gap S even when the gap S is small and to ensure reception of the occupant D by the airbag6with higher certainty.

In each of the aforementioned first to third examples, the thickness of the airbag6is restricted by the inner tethers11; however, thickness restriction is not limited to restriction by the inner tethers11provided that the thickness of the airbag6is restricted such that the airbag6is inserted into the gap S.

For example, an airbag41may be disposed as an alternative to the airbag6of the first example, and a pressure valve42may be disposed as an alternative to the inner tethers11of the first example, as illustrated inFIG. 7.

The airbag41is divided by a divider43in the vehicle width direction into two deployment chambers44aand44b.

The pressure valve42is disposed in the divider43. When the deployment gas is injected from the inflator7into the deployment chamber44aof the airbag41at a pressure higher than or equal to a predetermined pressure, the deployment gas flows into the deployment chamber44b.

Therefore, it is possible to deploy the airbag41with one of different thicknesses, by controlling the pressure of the deployment gas to be injected into the airbag41from the inflator7.

In each of the aforementioned first to third examples, the tether cutting member10mechanically cuts the inner tethers11; however, the tether cutting member10is not limited thereto.

For example, the cutting member10may be a fragile portion that is included in each inner tether11and can be cut by being subjected to a predetermined pressure. The fragile portions enable the airbag controller9to cut the inner tether11at the fragile portions by controlling the pressure inside the airbag6to thereby vary the deployment size of the airbag6.

In each of the aforementioned first to third examples, the airbag6is a side airbag that is disposed in the seat2and deployable toward the front along the side portion12of the automobile. However, the airbag6is not limited thereto provided that the airbag6is deployable with different thicknesses, into the gap S between the occupant D and the side portion12of the automobile.

For example, the airbag6may be a curtain airbag that is disposed so as to extend in a front-rear direction of the automobile along an upper edge portion of the side portion12of the automobile and that is deployable toward the lower side of the automobile along the side portion12.

In each of the aforementioned first to third examples, the airbag device4is disposed in an autonomously operated automobile but may be disposed in a manually operated automobile. However, in a manually operated automobile, the movement of the occupant D tends to change less excessively than in an autonomously operated automobile. Thus, the airbag device4is preferably disposed in an autonomously operated automobile.