GB2266075A

GB2266075A - Vehicle impact sensor arrangement

Info

Publication number: GB2266075A
Application number: GB9208458A
Authority: GB
Inventors: Dion Kruse; Lars Yngve Haland
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1992-04-16
Filing date: 1992-04-16
Publication date: 1993-10-20
Anticipated expiration: 2012-04-16
Also published as: GB2266075B; GB9208458D0; DE4312408B4; DE4312408A1

Abstract

The arrangement comprises at least one sensor (15) which is directly or indirectly fixed to the monocoque shell of a motor vehicle and which is responsive to inward movement of part (16) of a door mounted on a motor vehicle. The pan of the door (16) adjacent the sensor (15) is reinforced. In another arrangement the sensors may be mounted on the "B" post and be activated by movement of reinforcing bars (see Figs 3, 4). The sensors may activate an air bag 14 or seat belt pretensioners. <IMAGE>

Description

2266075 DESCRIPTION OF INVENTION "Improvements in or Relating to a Vehicle

Impact Sensor Arrangement" THE PRESENT INVENTION relates to a vehicle impact sensor arrangement, and more particularly relates to a vehicle impact sensor arrangement adapted to sense an impact on a side of a vehicle and to activate a safety device within the vehicle such as an air-bag or a seat belt pretensioner.

When a vehicle, such as a motor car, is involved in an accident the vehicle can accelerate or decelerate rapidly. In such a situation a person travelling within the vehicle may continue to move at the original speed of the vehicle, due to inertia, and may thus impact with part of the vehicle which has accelerated or decelerated. For example, if a vehicle is subjected to a front impact, the main body of the vehicle may stop relatively rapidly, whilst the person in the vehicle continues to travel forwardly. Thus, in effect, the person travelling in the vehicle is thrown forwardly on to a f ixed part of the vehicle, such as the steering wheel or the dash-board. In a side impact situation, however, a person sitting near the side of the impact may be hit by the intruding outer shell of the vehicle bef ore the speed of the main body of the vehicle is changed and very soon after the impact is initiated. These side impact conditions dema nds special sensor arrangements.

If a safety device is to be activated in response to a side impact, then the sensor which senses the side impact must be able to respond to a side impact before the inside part of the door of the vehicle hits the seat or hits the person sitting on the seat. Because the total distance between the outer skin of the vehicle and the seat is very short, the sensor has to react very rapidly.

It has been proposed previously to mount side impact sensors in the door of a vehicle, even if the safety device is not located in the door. In this case however there is a disadvantage to have to transmit the signal from the sensor on the door to a safety device mounted on the monocoque shell of the vehicle, because the transmission line can be damaged.

According to this invention there is provided a vehicle impact sensor arrangement for sensing a side impact wherein the sensor arrangement comprises at least one sensor which is directly or indirectly fixed to the monocoque shell of the motor vehicle and is responsive to inward movement of part of a door mounted on the motor vehicle, said inward movement being mechanically transmitted to the sensor.

Preferably the part of the door adjacent the sensor is reinforced.

Conveniently the sensor is responsive to a predetermined deformation force or a predetermined distance of deformation or a predetermined speed or acceleration of deformation.

In one embodiment the sensor is mounted on the floor of the motor vehicle adjacent the lower part of the door.

Preferably the whole extent of the lower part of the door is reinforced.

In an alternative embodiment the sensor is mounted on the B-post.

Conveniently at least one door of the vehicle is provided with a substantially horizontally extending reinforcing bar, one end of the reinforcing bar being located adjacent the sensor.

Advantageously the sensor activates a safety device, such as an air-bag or a pre-tensioner. Conveniently the air-bag is located on the monocoque shell of the vehicle or in a seat provided within the vehicle.

Advantageously the sensor is an electrical sensor, such as a switch or a pyrotechnic sensor such as a percussion cap.

Preferably the sensor responds to a force in excess of 1 to 2 kN.

Advantageously the sensor responds to a speed of the operative part of the sensor in excess of 1 to 2 metres per second.

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 of part of the monocoque shell of a motor vehicle provided with a vehicle impact sensor arrangement in accordance with the invention, with parts of the doors of the vehicle being shown in phantom, FIGURE 2 is a sectional view taken on the line IIII of Figure 1, FIGURE 3 is a view corresponding to Figure 1 but illustrating an alternative embodiment of the invention, FIGURE 4 is a sectional view taken on the lines IVIV of Figure 3, FIGURE 5 is an enlarged view illustrating a B-post of a motor vehicle with a sensor in accordance with the invention as illustrated in Figures 3 and 4, also illustrating the position of reinforcing bars present in the doors of the vehicle, FIGURE 6 is a view taken on the line VI-VI of Figure 5, and FIGURE 7 is a diagrammatic view of the sensor shown in Figure 6.

Referring initially to Figures 1 and 2 of the accompanying drawings the central part of the monocoque shell 1 of a motor vehicle is illustrated. The part of the shell that is illustrated def ines a roof 2, a f loor 3, a front windscreen area 4 and side openings 5,6, which receive doors 7,8 respectively. Each door is provided with a horizontally extending reinforcing bar 9,10. Mounted within the monocoque shell 1 is a seat 11 which is mounted on a raised or profiled part 12 of the floor 3. Mounted within the back 13 of the seat is an air-bag 14 which is illustrated in the inflated condition. The air-bag is located in the part of the back 13 of the seat which is adjacent the door 7 so that, when inflated, the air-bag forms a cushion between a person sitting on the seat and the door 7.

Mounted at the side edge of the profiled parts 12 of the floor 3 adjacent the door 7 is a sensor 15 which acts as a trigger to inflate the air-bag 14. The sensor 15, as can be seen more clearly f rom Figure 2 is located adjacent the lower part of the door 7 and, as can be seen f rom Figure 2, the lower part of the door 7 is provided with reinforcing 16 so that the lower part of the door 7 is substantially rigid. The reinforcing 16 extends over the whole extent of the lower part of the door. The reinforcing may be a solid element that forms the lower part of the door, or a filling that is introduced to hollow interior of the door and then sets. The lower part of the door need not be reinforced if the door is sufficiently stiff.

The sensor may be an electrical sensor, comprising, for example, a switch or may be a pyrotechnic sensor comprising, for example, a percussion cap.

It is to be appreciated that if the vehicle illustrated in Figures 1 and 2 is involved in a side impact, the sensor 15, which is mounted on the monocoque shell of the motor vehicle, is activated by inward movement of the reinforced part 16 of the door 7. This part of the door will, of course, move inwardly, towards the sensor 15, if the vehicle is subjected to a side impact, the inward movement being mechanically transmitted from the point of impact (which may, for example, be in the region of the horizontal reinforcing bar 9) to the lower part of the door by the various mechanical elements that form the door.

Turning now to Figures 3 and 4 a modified embodiment of the invention is illustrated. In Figures 3 and 4 the same reference numerals have been used, as in Figure 1 to identify the various parts of the arrangement shown in Figures 3 and 4 which are the same as in Figures 1 and 2. These parts will not be re-described.

It is to be observed, with reference to Figures 3 and 4, that the reinforcing bars 9 and 10 which are mounted in the doors 7 and 8 extend to lie adjacent the "B-post" 17 which f orms part of the monocoque shell 1 and which is located between the doors 7 and 8. Figure 3 illustrates three sensors 18A, 18B, 19 mounted on the B-post in alignment with the reinforcing bars 9 and 10. It is envisaged that in a practical embodiment of the invention either the sensors 18A and 18B would be provided or, alternatively, the sensor 19 would be provided. Each of sensors 18A and 18B are aligned with part of a respective reinforcing bar 9 or 10, whereas the sensor 19 is aligned with the end regions of both of the reinforcing bars 9 and 10.

As can be seen, the sensor 19 is connected not only to the air-bag 14 which is mounted in the side of the back of the seat 13, but also to a further air-bag 20 which is mounted in the roof of the vehicle and, when inflated, is adapted to be located between the head of a person sitting on the seat 11 and the door 7 of the motor vehicle.

-7 It is to be appreciated that if the vehicle illustrated in Figures 3 and 4 is subjected to a side impact, if either the door 7 or the door 8 is impacted and thus moves inwardly, the part of the reinforcing bar 9 or 10 will move inwardly and will contact either the sensors 18 and 20 or the sensor 19. The sensor will respond and will effect inflation of the airbags 14 and 20.

Figure 5 illustrates the sensor 19 mounted on the B-post 17, and shows how the reinf orcing bars 9 and 10 extend adjacent the sensor 19. This structure is also illustrated in Figure 6. Referring to Figure 6 the form of the doors 7 and 8 can be observed and the rubber seals 21,22 provided on the doors can be identified located between the inner parts of the doors and the outer parts of the "B-post" 17. The sensor 19 can be seen to comprise a housing 23 provided with a plunger 24 adapted to move inwardly into the housing 23. It can also be observed that the horizontal reinforcing bars 9,10 extend into protruding portions 25,26 of the doors 7 and 8, these protruding portions lying immediately in front of the B- post 17 and thus being aligned with the sensor 19.

Figure 7 is an enlarged view of the sensor 19, showing the housing 23 and the plunger 24. The plunger 24 can move inwardly by a distance Ildll, as illustrated, when subjected to a force 'IF", as indicated by the arrow. Since action and re-action are equal and opposite a corresponding force 'IF" will be applied to the housing 23 by the Bpost 17.

The sensor may be an electrical sensor, comprising a switch or may be a pyrotechnic sensor, comprising a percussion cap, and is preferably responsive to a predetermined deformation, in other words responsive to a predetermined movement of the plunger 24, or responsive to a deformation f orce, in which case means may be provided within the housing 23 to resist movement of the plunger 24, the plunger only moving if the force applied to the plunger exceeds a predetermined threshold, or the sensor 23 may be responsive to the speed of movement of the plunger 24 or to the acceleration of the plunger 24. Preferably the sensor is responsive to a combination of deformation speed and force, the force preferably being between 1 and 2 kN, and the speed having a value of between 1 and 2 metres per second.

Whilst the invention has been described with reference to embodiments in which the sensor activates an air-bag mounted in the seat of the motor vehicle and an airbag mounted in the roof of the motor vehicle, the sensor may trigger other safety devices such as an air-bag mounted in the B-post or even a pre-tensioner. It is envisaged that if the doors of the vehicle are sufficiently stiff, the reinforcing elements may be omitted. The sensor may be indirectly mounted on the monocoque shell of the vehicle by an intermediate supporting plate or the like. However, the sensor is mounted so that it is substantially fixed in position relative to the monocoque shell.

Claims

CLAIMS:

1. A vehicle impact sensor arrangement for sensing a side impact characterised in that the sensor arrangement comprises at least one sensor which is directly or indirectly fixed to the monocoque shell of the motor vehicle and is responsive to inward movement of part of a door mounted on the motor vehicle, said inward movement being mechanically transmitted to the sensor.

2. An arrangement according to Claim 1 wherein the part of the door adjacent the sensor is reinforced.

3. An arrangement according to any one of the preceding claims wherein the sensor is responsive to a predetermined deformation force or a predetermined distance of deformation or a predetermined speed or acceleration of deformation.

4. An arrangement according to any one of the preceding Claims wherein the sensor is mounted on the floor of the motor vehicle adjacent the lower part of the door.

5. An arrangement according to Claim 4 wherein the whole extent of the lower part of the door is reinforced.

6. An arrangement according to any one of Claims 1 to 3 wherein the sensor is mounted on the B-post.

7. An arrangement according to Claim 6 wherein at least one door of the vehicle is provided with a substantially horizontally extending reinforcing bar, one end of the reinforcing bar being located adjacent the sensor.

8. An arrangement according to any one of the preceding claims wherein the sensor activates a safety device.

9. An arrangement according to Claim 8 wherein the sensor activates an air-bag.

10. An arrangement according to Claim 9 wherein the air-bag is located on the monocoque shell of the vehicle.

11. An arrangement according to Claim 10 wherein the air-bag is mounted in a seat provided within the vehicle.

12. An arrangement according to any one of the preceding claims wherein the sensor is an electrical sensor.

13. An arrangement according to Claim 12 wherein the sensor comprises a switch.

14. An arrangement according to any one of Claims 1 to 11 wherein the sensor is a pyrotechnic sensor.

15. An arrangement according to Claim 14 wherein the sensor comprises a percussion cap.

16. An arrangement according to any one of the preceding claims wherein the sensor responds to a force in excess of 1 to 2kN.

17. An arrangement according to any one of the preceding Claims wherein the sensor responds to a speed of li- the aperture part of the sensor in excess of 1 to 2 metres per second.

18. A sensor arrangement substantially as herein described with reference to and as shown in Figures 1 and 2 of the accompanying drawings.

19. A sensor arrangement substantially as herein described with reference to and as shown in the Figures 3 to 7 of the accompanying drawings.

20. Any novel feature or combination of features disclosed herein.