WO2006007962A1

WO2006007962A1 - Safety device for a motor vehicle

Info

Publication number: WO2006007962A1
Application number: PCT/EP2005/007159
Authority: WO
Inventors: Friedrich Reiter; Clark Rüdebusch
Original assignee: Daimlerchrysler Ag
Priority date: 2004-07-17
Filing date: 2005-07-02
Publication date: 2006-01-26
Also published as: DE102004034564A1

Abstract

The invention relates to a safety device for a motor vehicle with a gas generator and an airbag (10), which can be filled by the gas generator in the event of a crash and which comprises at least one inflow or outflow opening (11), a gaseous stream being discharged from the latter in an exit direction (25, 25', 25''). The exit direction (25, 25', 25'') can be deviated at an angle in relation to a main outflow direction (24) by deviation means. The deviation means can be configured by a curvature of a flow channel that is situated between the airbag (10) and the inflow or outflow opening (11), or a baffle can constitute the deviation means. To improve the efficiency of the safety device, the exit direction (25, 25', 25'') can be deviated by an angle of at least 30° in relation to the main outflow direction (24) in the flow channel (12).

Description

Safety device for a motor vehicle

The invention relates to a safety device for a motor vehicle according to the preamble of claim 1.

From the state of the art safety devices are known, which have a gas generator and a gas bag connected thereto, wherein a supply or Abströmöff¬ voltage with variable size is arranged on the gas bag. In the case of an accident, the gas bag is filled explosively by the gas generator. The internal pressure of the gas bag is then controlled via the inflow or outflow opening, so that at a high In¬ nendruck, for example in a heavy load of Gas¬ sack, much gas escapes, and at a less strong load less gas flows. However, for optimum protection of the vehicle occupants, it is advantageous if, in the case of a stronger collision and thus a greater load on the gas bag, the internal pressure increases and the gas bag thus remains harder, and vice versa, the gas bag is softer in the case of a minor impact with a lower load is to protect against injury. The same applies to different load cases due to vehicle occupants of different weights. In a so-called "50%" man, the gas bag should be tuned harder than lighter-weight vehicle occupants, such as, for example, a so-called "5%" woman. Devices for controlling the flow resistance and thus the amount of outflowing gas are known, in which an infinitely variable filling and venting of the airbag takes place via an electronically or electrically controlled valve. However, such devices are very expensive. Moreover, this technical solution is not suitable for very short time intervals in the millisecond range, which are relevant in the present field of safety technology.

German patent application DE 101 11 566 A1 discloses a safety device with an airbag and at least one inflow or outflow opening which is channel-shaped at least in some areas and has a variable flow cross-section which is dependent on the pressure and which is in this subarea automatically adjusts depending on the speed of the exiting gas flow. Depending on the load case, the gas volume that flows out of the inflow or outflow opening can thereby be determined.

The invention has for its object to provide a Sicherheits¬ device for a motor vehicle, whose Wir¬ is improved kung, and at the same time is inexpensive.

The object is achieved by the features of claim 1. An¬.

In the apparatus according to the invention, an outlet direction of a gas flow emerging from an inlet or outlet opening can be deflected by a deflection means relative to a main outflow direction of the gas flow, preferably by an angle of at least 30 °, in particular by approximately 90 °. The flow resistance is determined by the reverse flow principle. einflussbar. The deflection means may be located within a flow channel with boundary walls or else outside a flow channel in an area which influences the flow. The deflection of the gas stream is preferably carried out during the outflow, ie when emptying the gas bag, as well as the filling of the gas bag can be additionally or alterna¬ tively influenced by a deflecting favorable.

In a preferred embodiment of the safety device according to the invention, the deflection means can be formed by a curvature of a flow channel which is arranged between the gas bag and the inlet or outlet opening. The flow channel preferably consists of an elastic material and, for example, is curved or bent from a defined bend region along its longitudinal extension to the inflow or outflow opening. The Abknickbe¬ rich can be given for example by a weak or predetermined kink. Preferably, the mouth cross-section of the inlet or outlet opening is then arranged approximately parallel to the main outflow direction, and the gas stream emerging from the flow channel is thereby deflected. The greater the flow velocity of the outflowing gas flow, the stronger the repulsive force of the diverted gas flow. The flow resistance is thus influenced by the recoil principle, comparable to the function of a lawn sprinkler system. The flow channel is bent by the recoil effect in the opposite direction, preferably at the predefined bend region. This principle is comparable to a bent garden hose, in which no water escapes, because the water builds up in front of the bent part. The size of the recoil force acting on the flow channel advantageously influences its flow cross section. At a high flow rate, the recoil effect is increased Curvature of the flow channel reinforced, and the Strömungs¬ cross-section narrows. As a result, less gas can escape at a discharge opening, whereby the airbag remains hard longer, which is advantageous in a strong impact. When the flow velocity is reduced by a less violent load case, the flow cross-section of the flow channel, according to the above-described mechanism of mechanics, conversely continues, whereby more gas can escape. The airbag can yield faster, which protects against injuries. Moreover, the applications of the known security devices are extended and advantageously combinable.

In a preferred embodiment, side walls of the outflow channel can be gas-permeable at least in some areas; they may for example have a perforation. The amount of outflowing gas can be adjusted via the thickness of the perforation and the entire system can be tuned.

In an alternative embodiment, the flow of the gas flow emerging from the inlet or outlet opening can be deflected by a baffle plate arranged offset outwardly in the main outflow direction. The baffle plate is then located outside the outflow channel. Depending on the severity of the load case, the flow speed of the austre¬ border gas flow can increase or decrease, whereby the force acting on the baffle recoil force is affected. This, in turn, can influence the strength of the deflection or the curvature of the flow channel, as a result of which the flow cross section in the bending region and thus the exiting gas volume are also determined. It is advantageous in this case that the principle of the invention is not dependent on complicated flow effects, which makes easier tuning possible. In addition, by the safety device according to the invention a fine-tuning to different boundary conditions allows, for example, different load cases or a different body weight of the vehicle occupants to be protected.

An influencing of the outlet direction can be effected by an an¬ other design of kraftumlenkenden means, spielsweise in the form of a baffle plate, which yields only from a certain be¬ force. This is advantageous, for example, in the case of a so-called "out-of-position" position in which a vehicle occupant bumps against an atypical point of the airbag, resulting in less pressure and the gas flow escaping at a lower speed In this constellation, the airbag can yield more quickly and protects against injuries Such a baffle plate can be used individually or in combination with a curved flow channel.

Due to the size of the recoil force acting on the impact plate, it is also possible to move further shut-off mechanisms, such as slides or levers, with which the flow cross-section can be influenced. This can be done a further fine tuning.

In a preferred embodiment, the outlet direction of the gas stream emerging from the inlet or outlet opening can be deflected by twisting the flow channel. In this case, several inflow or outflow openings can be arranged on a circle along the circumference of the flow channel, preferably at the same distance from one another, which effect a directed deflection of the exiting gas flow approximately perpendicularly to the longitudinal extent of the flow channel. It can also be provided only an inlet or outlet opening. The gas flow emerging from the inlet or outlet openings advantageously produces a repulsive force which acts in the direction of exit of the exiting gas flow and can cause the flow duct to distort from a predefined point. The flow channel may be formed so that it is already twisted in itself before the gas flow exits, and this predetermined distortion is enhanced by the outflow. The gas can thus be better managed.

In order to optimally design the safety device according to the invention for the respective application, various coatings or surface structures can be provided on the inner surfaces of the flow channel in all exemplary embodiments. Also conceivable are a shark skin structure, a golf ball surface, strong tissue structures and / or the perforations already mentioned. These must be designed precisely in order to optimize the flow for the load case. Furthermore, a combination with further flow optimization possibilities, such as with guide elements inside and / or outside of the flow channel and the like, can take place.

Favorable embodiments and advantages of the invention are described in the description and the other claims.

In the following the invention will be explained in more detail with reference to the embodiments described in the drawing. The drawing, the description and the claims contain numerous features in combination, which the person skilled in the art expediently also individually considers and will summarize meaningful further combinations.

Showing: 1 shows schematically a device according to the invention with an optimized inlet or outlet opening;

FIG. 2 shows a safety device according to FIG. 1, in which the flow channel is perforated; FIG.

3a shows an alternative embodiment of a erfindungs¬ contemporary safety device and

Fig. 3b is a plan view of the front side of the Strömungska¬ nals.

Fig. 4 shows schematically an alternative embodiment of a safety device with a baffle plate, through which a slider can be moved.

In the figures, the same or substantially the same elements are numbered with the same reference numerals.

FIG. 1 shows a safety device according to the invention with an airbag 10. A gas generator, which also belongs to the safety device, through which the airbag is filled in the event of an accident, is not shown. The gas bag 10 is associated with a arranged in its shell compensation hole 18 and a discharge opening formed as a discharge opening 11. Between the gas bag 10 and the inflow or outflow opening 11, a flow channel 12 is formed, which is curved in the main outflow direction 24 in the region of the inflow or outflow opening 11 and can bend in a bend region 17. The bending region 17 can be provided with a predetermined bending point.

Due to this curvature, the gas flow emerging in an exit direction 25 from the inlet or outlet opening 11 can be deflected by an angle of approximately 90 ° to the longitudinal extension of the flow channel 12. The mouth cross-section of the inflow or outflow opening 11 is approximately parallel to the main outlet. mung direction 24 arranged. Depending on the speed of the gas flow exiting from the inlet or outlet opening 11, a repulsive force acts on the flow channel 12 in the region of curvature, with the result that the latter is deflected against the outlet direction 25 along a deflection direction 26 and thereby in the bending region 17 forms a kink. As a result of this bend, the flow cross-section 19 of the flow channel 12 narrows. The greater the flow velocity of the exiting gas flow, the greater the flow channel 12 is deflected in the deflection direction 26, and the flow cross section 19 narrows more bent garden hose can escape through the en¬ gene flow cross section less gas, and the air bag stays hard longer. Conversely, at a lower flow rate, a less severe constriction of the flow area 19 of the flow passage 12 occurs, and more gas can escape, thereby softening the air bag more quickly, protecting it from injury in a less severe impact.

To generate and / or enhance this recoil effect, a baffle plate arranged parallel to the mouth cross-section of the inlet or outlet opening 11 and outwardly in the outlet direction 25 can be arranged, which is not shown in FIG.

The embodiment shown in Figure 2 differs from that of Figure 1 in that in the flow channel 12 a plurality of perforations 27 are introduced. For reasons of simplicity, only some of the perforations 27 are provided with reference numerals. Depending on the number and size of the perforations 27, a fine-tuning of the overall system can take place. Elements that are the same or essentially the same are numbered in the drawings with the same reference numerals be¬.

In FIG. 3 a, the flow channel 12 is wound in a section 20 in the main outflow direction 24. As a result, twists 23 form on the surface of the flow channel 12, which form the shape of constrictions on the inner surface, which are not recognizable in FIG. By means of these constrictions, directed deflecting of the exiting gas stream at an angle of approximately 90 ° to the longitudinal extension of the flow channel 12 is effected in the outlet directions 25, 25 ', 25 ". At the end of the flow channel 12 facing away from the gas bag 10, there are three inlet or outlet openings 11, 21, 22, which are arranged at the same distance from one another along the circumference of the flow channel 12.

A plan view of the end face of the end of the flow channel 12 facing away from the gas bag 10 is illustrated in FIG. 3b, where the exact arrangement of the three inlet or outlet openings 11, 21, 22 with the outlet direction 25, 25 'is shown in FIG. , 25 '' emerging gas stream is recognizable. Depending on the speed of the exiting gas flow, due to the recoil effect, a rotation of the flow channel 12 about its axis is effected in an opposite direction 26, whereby the twisting is intensified and the flow cross section is reduced more or less strongly depending on the flow velocity , As a result, the flow is optimized depending on the load case.

FIG. 4 schematically shows an alternative embodiment of a safety device with a baffle plate 13, which spaces in the direction of the air flow exiting from an inlet or outlet opening 11 designed as a discharge opening is arranged offset outwards. The baffle plate 13 is verbun¬ via a hinge connection 28 with a slider 29, wherein the hinge joint 28 is rotatably mounted about an axis perpendicular to the image plane arranged. Two legs 30, 31 are immovably connected to the hinge connection 28, wherein the leg 30 establishes the connection to the baffle plate 13, and that of the legs 31 connects to the slide 29. The baffle plate 13 is at rest at an angle, For example, about 30 ° ,, the Mündungsquer¬ cut the inlet or outlet opening 11 and spaced from this, and the slider 29 is in rest position laterally offset and spaced from the inlet or Ab¬ strömöffnung 11. Depending on the speed of the From the inflow or outflow 11 escaping gas flow, the baffle plate 13 is moved in a direction indicated by an arrow. As a result, the baffle plate 13 is rotated in this direction, which at the same time causes a displacement of the legs 30, 31 rotatably mounted about the hinge connection 28 and also a displacement of the slide 29 in the direction of the outlet opening 21. The new position after the rotation is indicated in Figure 4 with dashed lines. The slide 29 is pushed at the new position at a certain distance over the outlet opening 21, whereby the Strömungsquer¬ cut is influenced. This allows a further fine tuning of the overall system.

Claims

Patentanspräche

1. Safety device for a motor vehicle with a gas generator and in the event of an accident by the gas generator to be filled gas bag (10), the at least one inflow or Abströmδffnung (11) is assigned, from which a gas flow in an outlet direction (25, 25 '). , 25 ''), characterized in that the outlet direction (25, 25 ', 25' ') with respect to ei¬ ner main outflow direction (24) is deflected by a deflection means.

2. Safety device according to claim 1, characterized in that the outlet direction (25, 25 ', 25' ') relative to the main outflow direction (24) by the deflection means by an angle of at least 30 ° is deflected.

3. Safety device according to claim 1 or 2, characterized in that the deflection means by a curvature of between the gas bag (10) and the inflow or outflow opening (11) an¬ ordered flow channel (12) is formed.

4. Safety device according to one of the preceding An¬ claims, characterized in that the deflection means is a baffle plate.

5. Safety device according to one of the preceding An¬ claims, characterized in that the mouth cross-section of the inlet or outlet opening (11) is arranged approximately parallel to the main outflow direction (24).

6. Safety device according to one of the preceding An¬ claims, characterized in that the outlet direction (25, 25 ', 25' ') of the inlet or outlet opening (11) exiting gas flow through a main outflow direction (24) offset outwardly arranged Baffle plate (13) is deflectable.

7. Safety device according to claim 6, characterized in that the baffle plate (13) via a rotatably mounted Ge steering connection (28) with a slide (29) is connected.

8. Safety device according to claim 6 or 7, characterized in that the baffle plate (13) by the exiting gas flow is movable, whereby the slide (29) depending on the Ge speed of the exiting gas flow wholly or partially over the supply or Abströmδffnung (11) is movable.

9. Safety device according to one of the preceding An¬ claims, characterized in that the outlet direction (25, 25 ', 25' ') of the inlet or outlet opening (11) exiting gas flow by twisting of the flow channel (12) is deflected.

10. Safety device according to claim 9, characterized in that by twists (23) of the flow channel (12) on the inside constrictions are formed, which cause a directed deflection of the exiting gas flow in approximately perpendicular to the longitudinal extent of the flow channel (12).

11. Safety device according to claim 9 or 10, characterized in that a plurality of inflow or outflow openings (11, 21, 22) are arranged on a circle along the circumference of the flow channel (12).

12. Safety device according to claim 11, characterized in that the supply or Abstrδmöffnungen (11, 21, 22) are arranged with Glei¬ chem distance from each other.

13. Safety device according to one of the preceding claims An¬, characterized in that side walls (15, 16) of the flow channel (12) are perfo¬ ration.

14. Safety device according to one of the preceding An¬ claims, characterized in that the flow channel (12) is formed from an elastic Mate¬ rial.