WO1995003195A1

WO1995003195A1 - A safety arrangement for a motor vehicle and a connector for connecting shock tubes

Info

Publication number: WO1995003195A1
Application number: PCT/SE1994/000715
Authority: WO
Inventors: Torten Persson; Staffan Calsson; Yngve Håland
Original assignee: Autoliv Development Ab
Priority date: 1993-07-26
Filing date: 1994-07-26
Publication date: 1995-02-02
Also published as: GB2280529A; GB9315421D0

Abstract

In an airbag arrangement two sensors are provided. A first sensor (15) is mounted on the front door of a motor vehicle and is adapted to activate only an airbag (3) mounted on the front door. A second sensor (16) is mounted on the rear door (2) of the motor vehicle and is adapted to activate not only the airbag (3) on the front door but also second airbag (4) mounted on the back door. Each sensor transmits a shock along appropriate shock tubes to a connector associated with the appropriate airbag. Each connector then transmits the shock to the airbag through further shock tubes (9, 10; 11, 12). Each detector and each connector comprises a housing (20) defining a cavity (21) which is in communication with a repeater charge (26) of pyrotechnic material which is ignited in response to a shock being delivered to the cavity (21) through one of the shock tubes or from a percussion cap or pyrotechnic device within a seat (23) when penetrated by a stab (24) if the connector is also a sensor.

Description

A SAFETY ARRANGEMENT FOR A MOTOR VEHICLE AND A CONNECTOR FOR A CONNECTING SHOCK TUBES

The present invention relates to a safety arrangement and more particularly relates to a safety arrangement in a motor vehicle such as a motor car. In particular the invention relates to an airbag arrangement.

It has been proposed to provide a safety arrangement in a motor vehicle adapted to be activated in response to an accident occurring. One example of such a safety arrangement is an airbag adapted to be inflated in the event that a collision should occur to provide a degree of protection for the driver of the vehicle, or a passenger in the vehicle.

The present invention relates to an improved safety arrangement.

According to one aspect of this invention there is provided a safety arrangement for a motor vehicle, the arrangement comprising a plurality of sensors each adapted to respond to a sensed collision and at least one safety device, the safety device being adapted to be activated in response to a signal from any one of a predetermined plurality of the sensors, each such sensor being adapted to provide an output shock wave which is transferred by a shock tube to the safety device.

Preferably the safety device is an airbag.

Conveniently two sensors are provided associated with the airbag, activation of either sensor initiating inflation of the airbag, each sensor being connected by a shock tube to a connector, the connector being connected, by means of shock tube, to the airbag.

CONFIRMATION Advantageously the connector is connected by two shock tubes to two gas generators, the two gas generators being associated with the single airbag.

Conveniently the connector comprises a housing defining a cavity within the housing, each shock tube connected to the connector being in communication with the interior of the cavity, the cavity containing, or being in communication with, a repeater pyrotechnic charge adapted to be ignited in response to a shock wave delivered to the cavity through one of the shock tubes.

Advantageously at least one of the shock tubes is associated with a non-return valve adapted to permit the shock tube to deliver a shock to the cavity, but adapted to prevent the shock tube from receiving a shock from within the cavity.

Preferably each non-return valve comprises a resiliently biased metal strip or flap adapted to cover the end of an associated shock tube which otherwise would be in communication with said cavity.

Conveniently the connector also comprises a sensor, the cavity being provided with means retaining a percussion cap or pyrotechnic charge, so that any shock generated on ignition of the percussion cap or charge is directed to the cavity, means being provided adapted to activate the percussion cap or charge in response to a collision.

Advantageously the means to initiate the percussion cap or pyrotechnic charge comprise a stab, the stab being adapted to move to penetrate the percussion cap or pyrotechnic charge in response to deformation of part of the vehicle. The preferred arrangement comprises at least two sensors and at least two separate airbags. The arrangement is such that if one of the two sensors is activated, one specific airbag will be inflated whereas if the other sensor is activated both of the airbags will be inflated.

In a preferred embodiment one sensor is mounted on the front door of a motor vehicle, with one airbag being mounted on the front door, and another sensor is mounted on the back door, a second airbag being mounted on the back door.

Preferably, activation of either the sensor on the front door or the sensor on the back door will initiate inflation of the airbag on the front door, whereas activation of the sensor on the back door will initiate inflation not only of the airbag on the front door but also will initiate inflation of the airbag on the back door.

The invention also provides a connector for connecting shock tubes, the connector comprising a housing defining a cavity, passages leading to the cavity to receive shock tubes so that the ends of the shock tubes may be in communication with the cavity, and a repeater charge within the cavity or in communication with the cavity.

Preferably at least one passage for a shock tube is associated with an non-return valve adapted to permit a shock from the associated shock tube to enter the cavity to prevent any shock wave present in the cavity being communicated to the respective shock tube.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic side view illustrating the two side doors of a motor vehicle, illustrating sensors and airbag arrangements mounted within the doors;

Figure 2 is a diagrammatic horizontal sectional view illustrating a sensor and a connector of Figure 2;

Figure 3 is a vertical sectional view through the sensor and connector of Figure 2;

Figure 4 is a view corresponding to Figure 2 but showing a modified embodiment of the invention; and

Figure 5 is an enlarged sectional view of part of Figure 1.

Referring initially to Figure 1 of the drawings, the front door 1 and the rear door 2 of a motor vehicle are illustrated schematically.

An airbag arrangement 3 is illustrated mounted in the front door and an airbag arrangement 4 is illustrated mounted in the rear door. Each airbag arrangement is provided with two gas generators adapted to inflate a single airbag. Thus the airbag arrangement 3 comprises a single airbag which is provided with gas generators 5, 6 and the airbag arrangement 4 comprises a single airbag which is provided with gas generators 7, 8.

Each gas generator is triggered by a respective length of shock tube 9,10,11,12 respectively. (The shock tube may be sold under the Trade Mark "NONEL") . The two shock tubes 9 and 10 are each connected to a connector 13 and the two shock tube 11 and 12 are each connected to a connector 14. The lengths of the shock tubes 9 and 10 may be different and the lengths of the shock tubes 11 and 12 may be different.

A sensor 15 is provided mounted in the front door adapted to sense a side collision on the front door. A further sensor 16 is provided mounted on the rear door adapted to sense a side collision on the rear door.

The arrangement is such that if the sensor 15 detects an impact, the airbag 3 in the front door is activated whereas if the sensor 16 senses an impact, then both the airbag 3 in the front door and the airbag 4 in the rear door are activated.

The sensor 15 is connected by a length of shock tube 17 to the connector 13 and the sensor 16 is connected by a length of shock tube 18 to the connector 13 and by a further length of shock tube 19 to the connector 14.

It is to be understood that each detector 15, 16 is adapted to generate a pyrotechnic pulse or shock in response to a collision, that pulse or shock being transmitted, by the associated shock tube, as will be described hereinafter to the connector 13 and/or to the connector 14.

If the sensor 15, in the front door, detects an impact, a Shockwave is passed through the shock tube 17 to the connector 13, and from the connector 13, through the lengths of shock tube 9 and 10, to the gas generators 5 and 6 of the airbag 3, thus causing the airbag of the airbag arrangement 3 to inflate. If the sensor 16, in the rear door, detects an impact, a shock wave is passed through the shock tube 18 to the connector 13 and also through the shock tube 19 to connector 14. From the connectors 13 and 14 shock waves pass through the shock tubes 9, 10, 11 and 12 to the gas generators 5, 6, 7 and 8. Thus the airbags of both the front airbag arrangement 3 and the rear airbag arrangement 4 are activated.

Figure 2 illustrates the sensor 16 and the connector 13.

The sensor 16 comprises a housing 20 which defines, within it, a central open chamber 21.

The top of the chamber is connected by means of a bore 22 to an enlarged seat 23 adapted to contain a percussion cap or other pyrotechnic device.

A stab 24 is located in position adjacent the seat 23, the stab being made of metal or hard plastic.

The housing 20 is mounted in a fixed position and the stab 24 is connected to the outer skin of the vehicle so that if the outer skin is deformed inwardly the stab will penetrate the percussion cap or pyrotechnic charge within the seat 23. If the speed of deformation of the outer skin of the vehicle is in excess of a predetermined limit, the percussion cap or pyrotechnic charge will be ignited, providing a shock wave to the cavity 21.

Contained in a recess 25 at the bottom of the cavity 21 is a repeater pyrotechnic charge 26. This repeater pyrotechnic charge is designed so that whenever there is a shock present within the cavity 21 the repeater pyrotechnic charge 26 is ignited, thus providing a rather greater shock within the cavity 21.

The two shock tubes 18, 19 each have a terminal portion, the terminal portions passing through passages 27, 28 formed in the side wall of the housing 20, the ends of the shock tube thus communicating with the chamber 21.

It is thus to be understood that when the percussion cap of pyrotechnic charge within the seat 23 is activated, a large pressure or shock wave is created within the cavity 21, which initiates a pressure or shock wave which travels along the shock tubes 18 and 19.

The shock wave travelling along the shock tube 18 is directed towards the connector 13.

The sensor 15 may be of the same design as the sensor 16, but with only the shock tube 17 in communication with the cavity of the sensor.

The connector 13 comprises a cylindrical housing 30 defining, within it cover, a cavity 31. The end of the shock tube 18 passes through a passage 32 to communicate with the cavity 31, and the shock tubes 9, 10 and 17 pass through passages 33, 34 and 35 so that the terminal portions of the shock tubes are in communication with the cavity 31 within the housing 30.

Non-return valves 36, 37 are provided associated with the ends of the shock tubes 18 and 17. The non-return valves may comprise resiliently biased strips of metal or other material which, in an initial position, are biased against the end of the respective shock tube, thus shielding the end of the shock tube from any shock present within the cavity 31. However, it is to be understood that the nature of each non-return valve is such that if a shock is present on the respective shock tube, that shock will cause the non-return valve to open, permitting the shock to enter the cavity 31.

A recess 38 is provided within the cavity containing a repeater pyrotechnic charge 39, corresponding to the pyrotechnic charge 26 of the sensor 16.

It is, therefore, to be appreciated that if a shock from the sensor 15, generated in response to a collision being sensed by the sensor 15, travelling along the shock tube 17, reaches the connector 13, the shock wave will pass the non-return valve 37 and enter the cavity 31, but the non-return valve 36 will operate to prevent the shock wave from travelling on down the shock tube 18. However, the shock wave entering the cavity 31 will trigger the pyrotechnic charge 38 thus providing an enhanced shock wave within the cavity 31. This enhanced shock wave will initiate a shock wave in each of the shock tubes 9 and 10. The shock waves will travel along the shock tubes 9 and 10 to activate the gas generators 5 and 6 thus causing the airbag of the airbag arrangement 3 to inflate.

On the other hand, it is to be appreciated, that if a collision is sensed by the sensor 16, shock waves will travel along both the shock tubes 18 and 19, and the shock wave travelling along the shock tube 18 will enter the cavity 31 of the connector 13, thus again triggering the pyrotechnic charge 38 and causing shocks to travel along the shock tubes 9 and 10 to activate the gas generators 5 and 6, inflating the airbag of the airbag arrangement 3. Simultaneously, however, a shock will travel along the shock tube 19 to the connector 14 (which is on a very similar design to that of the connector 13) thus causing activation of the gas generator 7 and 8 and inflation of the airbag of the airbag arrangement 4.

By appropriate positioning of non-return valves, such as the non-return valves 36 and 37, a predetermined response can be achieved, with regard to inflation of one or more airbags in response to the activation of any particular sensor. However, it is of particular importance to note that in the described embodiment the airbag 3 mounted in the front door is activated in response either to activation of the sensor 15 in the front door or in response to activation of the sensor 16 in the rear door.

Referring to Figure 4 it is to be appreciated that the connector 13 has been modified not only to be a connector but also to be a sensor. The housing 30 has been provided with a bore 22' communicating with the chamber 31, the bore 22' leading to an enlarged seat 23' to receive a percussion cap to cooperate with a stab 24' . The bore 22' , seat 23' and stab 24' thus correspond with the bore 22, seat 23 and stab 24. The connector 14 may similarly be adapted to be a sensor.

In the arrangement of Figure 4 if the sensor 15 detects an impact, the airbag 3 in the front door is activated. If the sensor 13 detects an impact, the airbag in the front door is again activated. The non-return valves prevent the shock wave from travelling down the shock tubes 17 or 18.

If the sensor 16 detects an impact both the airbag 3 on the front door and the airbag 4 on the rear door are activated. If the connector 14 is adapted to be a sensor, if that sensor 14 detects an impact the airbag 4 in the rear door will be activated. Depending upon the positioning of non-return valves, the airbag 3 in the front door may or may not be activated. It is thus to be appreciated that a system may thus be designated that is deemed to be appropriate for any particular situation.

Referring now to Figure 5 a special arrangement is provided where the shock tube passes the junction between each door 40,41 and the ^MB"-Post 42. Figure 5 is an enlarged view of the junction between the door 40 and the "B"-Post 42. It can be seen that the shock tube 19 terminates in a cavity 43 defined within a housing 44. The housing 44 is somewhat similar to the housing 20 of the sensor 16 described above. The base of the housing 44 defines a cavity 45 which receives a repeater pyrotechnic charge 46. One side wall of the cavity 43, however, is formed by a rupturable membrane 47 formed, for example, of aluminium foil or the like, the membrane must be such as to retain the hermetic seal and integrity of the cavity 43, whilst being such that it will rupture in appropriate circumstances. The housing 44 is mounted in the door 40 with the membrane 47 being located immediately adjacent a corresponding membrane 47' in a corresponding housing 44' which is mounted in the "B'^Posted 42.

It is to be appreciated that there is no mechanical connection between the housing 44 and the housing 44' , permitting the door to be opened and closed freely. However, when the door is in the closed condition the housings 47 and 47^• are in the relative position illustrated in Figure 5. In the event that a shock wave passes through the shock tube 19 and enters the cavity 43, the repeater pyrotechnic charge 46 will be ignited, thus providing a rather greater shock wave within the cavity 43. This shock wave will rupture the membrane 47, and also rupture the immediately adjacent membrane 47', igniting the repeater pyrotechnic charge 46* which is present within the cavity 43' within the housing 44'. A shock is consequently transmitted through the shock tube 19• which is connected to the housing 44' .

It will thus be readily appreciated that the shock present in the shock tube 19 is effectively transmitted across the gap between the door and the ^MB^M-Post. In a similar way the shock is transmitted across the gap between the ^MB^M-Post 42 and the door 41, the shock thus being transmitted onwards through the shock tube 18 in door 41.

Claims

CLAIMS :

1. A safety arrangement for a motor vehicle, the arrangement comprising a plurality of sensors each adapted to respond to a sensed collision and at least one safety device, the safety device being adapted to be activated in response to a signal from any one of a predetermined plurality of the sensors, each such sensor being adapted to provide an output shock wave which is transferred by a shock tube to the safety device.

2. An arrangement according to claim 1 wherein the safety device is an airbag.

3. An arrangement according to claim 2, wherein two sensors are provided associated with the airbag, activation of either sensor initiating inflation of the airbag, each sensor being connected by a shock tube to a connector, the connector being connected, by means of shock tube, to the airbag.

4. An arrangement according to claim 3, wherein the connector is connected by two shock tubes to two gas generators, the two gas generators being associated with the single airbag.

5. An arrangement according to claim 3 or 4, wherein the connector comprises a housing defining a cavity within the housing, each shock tube connected to the connector being in communication with the interior of the cavity, the cavity containing, or being in communication with, a repeater pyrotechnic charge adapted to be ignited in response to a shock wave delivered to the cavity through one of the shock tubes.

6. An arrangement according to claim 5, wherein at least one of the shock tubes is associated with a non¬ return valve adapted to permit the shock tube to deliver a shock to the cavity, but adapted to prevent the shock tube from receiving a shock from within the cavity.

7. An arrangement according to claim 6, wherein each non-return valve comprises a resiliently biased metal strip or flap adapted to cover the end of an associated shock tube which otherwise would be in communication with said cavity.

8. An arrangement according to any one of claims 5 to 7, wherein the connector also comprises a sensor, the cavity being provided with means retaining a percussion cap or pyrotechnic charge, so that any shock generated on ignition of the percussion cap or charge is directed to the cavity, means being provided adapted to activate the percussion cap or charge in response to a collision.

9. An arrangement according to claim 8, wherein the means to initiate the percussion cap or pyrotechnic charge comprise a stab, the stab being adapted to move to penetrate the percussion cap or pyrotechnic charge in response to deformation of part of the vehicle.

10. An arrangement according to one of the preceding claims comprising at least two sensors and at least two separate airbags.

11. An arrangement according to claim 10, wherein one sensor is mounted on the front door of a motor vehicle, with one airbag being mounted on the front door, and another sensor is mounted on the back door, a second airbag being mounted on the back door.

12. An arrangement according to claim 11, wherein activation of either the sensor on the front door or the sensor on the back door will initiate inflation of the airbag on the front door, whereas activation of the sensor on the back door will initiate inflation not only of the airbag on the front door but also will initiate inflation of the airbag on the back door.

13. A connector for connecting shock tubes, the connector comprising a housing defining a cavity, passages leading to the cavity to receive shock tubes so that the ends of the shock tubes may be in communication with the cavity, and a repeater charge within the cavity or in communication with the cavity.

14. A connector according to claim 13, wherein at least one passage for a shock tube is associated with an non¬ return valve adapted to permit a shock from the associated shock tube to enter the cavity to prevent any shock wave present in the cavity being communicated to the respective shock tube.

15. A connector according to any one of the preceding claims also comprising a sensor, the cavity being provided with means retaining a percussion cap or pyrotechnic charge, so that any shock generated on ignition of the percussion cap or charge is directed to the cavity, means being provided adapted to activate the percussion cap or charge in response to a collision.

16. A connector according to claim 15, wherein the means to initiate the percussion cap or pyrotechnic charge comprise a stab, the stab being adapted to move to penetrate the percussion cap or pyrotechnic charge in response to deformation of part of the vehicle.