Air bag apparatus for a small size vehicle

To provide an air bag apparatus for a small size vehicle, wherein a seat for a driver is provided at a rear portion of a vehicle body and an instrument panel, which a driver on the seat can visually observe is provided at a front portion of the vehicle body. The air bag apparatus assures a wide range of inflation and expansion of an air bag and can be applied to a conventional small size vehicle without a significant design change. A plurality of air bags which can constrain a driver on a seat from a forward direction are connected to each other by a connection mechanism and are accommodated in a folded state in an instrument panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2002-118664, filed in Japan on Apr. 22, 2002, the entirety of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a small size vehicle, wherein a seat for a driver is provided at a rear portion of a vehicle body and an instrument panel, which a driver on the seat can visually observe, is provided at a front portion of the vehicle body. More particularly, the present invention relates to improvements in an air bag apparatus provided in a small size vehicle.

2. Description of Background Art

Conventionally, in a motorcycle disclosed in the official gazette of, for example, Japanese Patent Laid-Open No. 2001-219884, a single air bag in a folded state is disposed forwardly of a handle bar or the motorcycle.

In order to effectively constrain the driver on the seat, it is necessary for the air bag to be inflated and expanded to a wider range. If a single air bag is used such that it is expanded to a wide range, then it is difficult with a conventional small size vehicle such as a motorcycle to assure a space for accommodation of a large size air bag. Accordingly, it is sometimes necessary to effect significant design changes to accommodate such an air bag.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-described circumstance. It is an object of the present invention to provide an air bag apparatus for a small size vehicle, which assures a wide range of inflation and expansion of an air bag and can be applied to a conventional small size vehicle without the necessity of significant design changes to accommodate the air bag.

In order to attain the above-described object, according to a first aspect of the present invention, a small size vehicle includes a seat for a driver provided at a rear portion of a vehicle body and an instrument panel, which a driver on the seat can visually observe, provided at a front portion of the vehicle body. An air bag apparatus for the small size vehicle includes a plurality of air bags, which can constrain the driver on the seat from a front of the driver. The plurality of air bags are connected to each other by a connection mechanism and are accommodated in a folded state in the instrument panel.

With the above configuration, when the plurality of air bags are inflated and expanded, all of the air bags are connected to each other by the connection mechanism and are expanded over a wide range. Thus, the function of a large air bag can be secured by the plurality of small air bags while a wide range of expansion can be covered by the plurality of air bags to constrain the driver effectively. In addition, since each of the air bags may be of a small size, it is easy to assure the space for accommodating the air bags, and the air bag apparatus can be applied to a conventional small size vehicle without the necessity of significant design changes to accommodate the air bags.

Furthermore, according to a second aspect of the present invention, the air bag apparatus for a small size vehicle is provided, wherein the connection mechanism connects a pair of left and right air bags accommodated in a folded state on the opposite left and right sides of the instrument panel to each other. The connection mechanism is securely fastened to the vehicle body. With the above configuration, leftward and rightward movements of the pair of left and right inflated and expanded air bags can be restricted by the connection mechanism, which is securely fastened to the vehicle body to constrain the driver effectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, an embodiment of the present invention is described in connection with an example of the present invention shown in the accompanying drawings. It should be noted that the same reference numerals have been used to identify the same or similar elements throughout the several views.

FIGS. 1 to 6show an example of the present invention.FIG. 1is a side elevation of a motorcycle.FIG. 2is a view in a direction indicated by an arrow2inFIG. 1.FIG. 3is a view corresponding toFIG. 2but in a state wherein a steering handle bar is omitted for clarity.FIG. 4is an enlarged sectional view taken along line4—4ofFIG. 2.FIG. 5is a side elevational view corresponding toFIG. 1but in a state wherein the air bags are inflated and expanded.FIG. 6is a view in a direction of an arrow6inFIG. 5.

Referring first toFIG. 1, a body B of the motorcycle V includes a body frame (not shown), which is covered with a body cover6made of a resin material. A front wheel WF is supported rotationally at a lower end of a front fork7supported for steering movement at a front end of the body frame. A steering handle bar8is connected to an upper portion of the front fork7. Furthermore, a rear portion of the vehicle body B includes a main scat9for seating a driver in such a manner as to be positioned above a rear wheel WR. A pillion seat10is provided for seating a passenger on the rear side with respect to the main seat9. Side bags11are disposed on the left and right of the rear wheel WR. Furthermore, a trunk12is disposed upwardly of the rear wheel WR, rearwardly of the pillion seat10.

Referring also toFIGS. 2 and 3, an instrument panel13, which can be visually observed by a driver on the main seat9, is provided at a front portion of the body B. A plurality of air bag modules14are provided in the instrument panel13. In the present example, a pair of left and right air bag modules14,14are provided on the opposite left and right sides of the instrument panel13. However, it should be understood that additional air bag modules14could also be provided at other locations on the instrument panel13in addition to or as an alternative to the pair of left and right air bag modules14,14.

Referring toFIG. 4, each air bag module14includes an air bag housing15formed in the shape of a box. The air bag housing15is open at an upper end thereof and is formed integrally with the instrument panel13. An air bag16is accommodated in the air bag housing15. Furthermore, an inflator17is provided for generating gas for inflating and expanding the air bag16.

An opening16aof the air bag16is accommodated in a folded state in the air bag housing15. The opening16ais attached in an airtight manner to an upper open end of a supporting box18, which is formed in the shape of a box. The supporting box18is open at an upper end thereof and is accommodated in the air bag housing15and is secured to the air bag housing15, and the inflator17is attached to a lower closed end of the supporting box18.

Incidentally, a connecting net19serving as a connection mechanism is connected at one end side thereof to one of the air bags16of the air bag modules14,14disposed on the opposite sides of the instrument panel13. In particular, the pair of left and right air bags16accommodated in a folded state on the opposite sides of the instrument panel13are connected to each other by the connecting net19. In addition, the connecting net19is fixedly fastened at the other end thereof to the body B immediately forwardly of the main seat9.

Referring further toFIGS. 5 and 6, the connecting net19includes a net portion19awhich connects the two air bags16to each other, upon inflation and expansion of the two air bags16, in such a manner that it covers part of the two air bags16. A pair of supporting rope portions19b,19bare each connected at one end thereof to the net portion19a. In addition, each of the two supporting rope portions19b,19bis connected at one end thereof to the net portion19asuch that, upon inflation and expansion of the two air bags16, the two supporting rope portions19b,19bexpand into a substantially V-shape in plan while the other ends of the two supporting rope portions19b,19bare securely fastened to the body B immediately forwardly of the main seat9.

A substantially T-shaped accommodating groove20is in communication with the insides of the two air bag housings15. The accommodating groove20is formed on an upper face of the body B and extends from a position immediately forwardly of the main seat9to the locations of the two air bag modules14,14. The connecting net19is accommodated in the accommodating groove20with the two air bags16accommodated in a folded state in the air bag housings15.

Furthermore, a cover21made of a synthetic resin material is attached to the upper face of the body B. The cover21includes first lid portions21a,21awhich cover over upper end openings of the air bag housings15of the two air bag modules14,14and a second lid portion21bformed integrally with the first lid portions21a,21ain a substantially T-shape in such a manner as to cover over the accommodating groove20. The second lid portion21bconnects the two first lid portions21a,21a.

In addition, a fragile portion21cextends from a central portion in a widthwise direction of the second lid portion21bto central portions of the two first lid portions21a,21aand hinge portions21d,21dare disposed on the opposite sides of the fragile portion21c. The fragile portion21cand the hinge portions21dare formed on the cover21. The cover21is formed such that it can be broken readily by force acting upon the cover21by inflation and expansion of the two air bags16. Operation of the connecting net19is in response to the inflation and expansion of the two air bags16. In response to the break of the fragile portion21c, the cover21is opened around the hinge portions21d,21d. In particular, the connecting net19is accommodated in the accommodating groove20of the body B when the two air bags16are in a folded state. However, upon inflation and expansion of the two air bags16, the connecting net19breaks the cover21and projects outwardly from the body B.

Subsequently, action of the present example is described. A plurality of, for example, a pair of left and right, air bags16are accommodated in a folded state on the opposite sides of the instrument panel13. The net portion19aon one end side of the connecting net19is accommodated in the body B when the two air bags16are in the folded state. However, the net portion19aprojects from the body B to connect the two air bags16to each other, upon inflation and expansion of the two air bags16. The net portion19ais connected to the two air bags16. In other words, the pair of left and right air bags16, which can constrain a driver on the pillion seat10from a forward direction, are connected to each other by the connecting net19the pair of air bags16are accommodated in a folded state on the opposite left and right sides of the instrument panel13.

Accordingly, when the pair of air bags16are inflated and expanded, the two air bags16are connected to each other by the connecting net19and are expanded over a wide range as shown inFIG. 6. Thus, the function of a large size air bag can be accomplished by the pair of small size air bags16. Accordingly, a wide range of expansion can be covered by the pair of air bags16to constrain the driver effectively.

In addition, since each of the air bags16may be of a small size, it is easy to assure the space for accommodating the air bags16. Accordingly, the air bag apparatus can be applied to a conventional small size vehicle which includes the instrument panel13without a significant design change.

Furthermore, since the pair of supporting rope portions19b,19b, which form part of the connecting net19, are securely fastened to the body B, leftward and rightward movements of the pair of left and right inflated and expanded air bags16can be restricted by the connecting net19securely fastened to the body B to constrain the driver effectively.

While, in the example described above, the two air bags16are connected to each other by the connecting net19having the net portion19a, it is otherwise possible to use a connection belt which does not have a net portion as a connection mechanism in place of the connecting net19.

While the example of the present invention is described above, the present invention is not limited to the example described above, but various design alterations can be made without departing from the present invention recited in the claims.

As described above, according to the first aspect of the present invention, the driver can be constrained effectively by the air bags having a wide expansion range. In addition, the air bag apparatus can be applied to a conventional small size vehicle without a significant design change.

Furthermore, according to the second aspect of the present invention, leftward and rightward movements of the pair of left and right inflated and expanded air bags can be restricted by the connection mechanism securely fastened to the vehicle body to constrain the driver effectively.