Airbag

Abstract

The invention relates to an airbag (1) with a cushion (2), a cold gas generator (8) which is fluidically connected to the cushion (2) and which is filled with a pressurized gas, wherein the cold gas generator (8) comprises a closure (9) which can be released by an electrical current pulse, wherein when activated by releasing the closure (9), the cold gas generator (8) abruptly releases the pressurized gas into the cushion (2), thereby inflating the cushion (2), and an actuator (3) for releasing the closure (9), wherein the actuator (3) comprises an induction coil (5) and a magnet (4) connected to a first end of a tension element (6), and a releasable blocking mechanism (7) is provided, which fixes the magnet (4) relative to the induction coil (5) in a predetermined position with a defined holding force, wherein the magnet (4) is fixed relative to the induction coil (5) by exerting a tension force on the tension element (6) which exceeds the holding force of the blocking mechanism (7), or the induction coil (5) can be displaced relative to the magnet (4) by exerting a tensile force on the actuator (3) which exceeds the holding force of the blocking mechanism (7), thereby generating the current pulse in the induction coil (5) required to release the fastener (9).

Description

[0001] Airbag

[0002] The present invention relates to an airbag having the features of the preamble of claim 1.

[0003] Airbags of the generic type comprise an inflatable cushion and a cold gas generator which contains a large amount of a highly pressurized gas, preferably nitrogen or CO2 in liquid form. When activated, the cold gas generator suddenly releases a very high volume flow of gas, which is then fed into the cushion to inflate it.

[0004] Such airbags are used, for example, to protect motorcyclists, skiers, cyclists, drivers of scooters or similar mobile vehicles. It is also conceivable to use such airbags to protect people at risk of falling or athletes practicing risky sports.

[0005] The airbag can, for example, be integrated into an item of clothing or worn as a separate item, e.g. in the form of an airbag vest. The airbag comprises the cushion which, in the intended arrangement of the airbag, is arranged in relation to the person to be protected in such a way that, when inflated, it unfolds to such a geometry that, in the event of a fall or a general hazard, the person to be protected is immersed in the cushion with the part of the body to be particularly protected or is covered by the cushion in the area of the part of the body to be protected.

[0006] Furthermore, such airbags can also be used wherever an abruptly inflated cushion can be of use. These can be, for example, swimming aids, buoyancy devices, rescue devices for rescuing people and creating free space or lifting devices and pressure devices in general.

[0007] The inflated cushion of the airbag deliberately creates a corresponding buoyancy or displacement volume, which generates the buoyancy, creates corresponding free spaces or can also be used to lift objects.

[0008] The cold gas generator in the airbag comprises a releasable closure which can be released by an electrical current pulse when the airbag is activated, so that the gas flow is released.

[0009] Such a gas generator is known, for example, from the publication DE 195 24 094 Al. The electrical current pulse is generated there with the aid of an energy source, which is supplied with energy from a car battery, for example.

[0010] A disadvantage of this solution is that an external energy source must be provided to activate the airbag.

[0011] Against this background, the invention is based on the task of providing an airbag with a cushion and a cold gas generator which can be activated without an external energy source.

[0012] In accordance with the invention, an airbag with the features of claim 1 is proposed for solving the task. Further preferred embodiments of the invention can be found in the subclaims, the figures and the associated description.

[0013] According to the basic idea of the invention, it is proposed that the actuator for releasing the closure comprises an induction coil and a magnet connected to a first end of a tension element, and a releasable blocking mechanism is provided which fixes the magnet in a predetermined position with respect to the induction coil with a defined holding force, wherein the magnet can be displaced relative to the induction coil by exerting a tensile force on the tensile element which exceeds the holding force of the blocking mechanism, or the induction coil can be displaced relative to the magnet by exerting a tensile force on the actuator which exceeds the holding force of the blocking mechanism, thereby generating the current pulse in the induction coil which is necessary for releasing the closure.

[0014] The proposed airbag thus comprises an actuator that can be activated independently of an external energy source, as it generates the energy required to release the closure itself in the form of a short current pulse. Activation is triggered by pulling on the tension element or on the actuator, and the resulting relative movement of the magnet by the induction coil or of the induction coil via the magnet after the holding force exerted by the blocking mechanism has been overcome. This means that the airbag can be used as a stand-alone unit and does not require any integration into a higher-level control or energy structure. If the airbag is to be used, for example, for rescuing and creating free space or as a buoyancy aid, the airbag can also be activated manually by the person operating it pulling on the tension element itself and thus actively triggering the airbag. To ensure that the airbag is not triggered unintentionally, e.g. in the event of vibrations, the magnet is held in place against the induction coil by the blocking mechanism up to the predetermined holding force. The holding force is dimensioned so that natural accelerations or other external mechanical effects on the airbag and in particular on the actuator do not in any case lead to the tensile forces acting on the tensile element and the magnet exceeding the predetermined holding force and the airbag being unintentionally triggered.

[0015] It is further proposed that the actuator comprises a housing to which the induction coil is attached, and the housing comprises a guide for the magnet, which is designed such that the magnet is guided relative to the induction coil during the relative movement and, in particular, executes a movement through the induction coil. The magnet and the induction coil are thus locally aligned with each other by the housing, and the movement of the magnet is precisely defined in its course by the guide in relation to the induction coil in such a way that the magnet is moved through the induction coil or the induction coil is moved over the magnet. It is further proposed that a steel plate is provided on the housing, to which the magnet is fixed by its magnetic attraction force against the tensile force exerted by the pulling element. The steel plate forms a device for fixing the magnet, wherein the magnetic properties of the magnet itself are utilized to fix the magnet. The magnetic force acting between the steel plate and the magnet can supplement the holding force of the blocking mechanism or, alternatively, be part of the holding force exerted by the blocking mechanism. The steel plate would thus be part of the blocking mechanism.

[0016] It is further proposed that the blocking mechanism comprises a locking element which is loaded by a spring and fixes the magnet in the predetermined position, and the force exerted by the spring on the locking element defines the holding force exerted on the magnet. The spring force of the spring is designed such that it defines the holding force, wherein a steel plate with a holding force acting on the magnet can also be provided.

[0017] It is also proposed that a guide contour is provided on the housing, in which the locking element is guided in a movement from a locking position to a release position. The guide contour on the housing guides the movement of the locking elements relative to the housing and thus also relative to the magnet.

[0018] It is further proposed that the current pulse comprises a current intensity of 1.2 A in a time span of 2 ms, preferably 1.75 A in a time span of 0.5 ms. The proposed current intensities and durations of the current pulses have been shown in various tests to be sufficient for releasing the seals of the applicant's cold gas generators.

[0019] It is further proposed that the magnet comprises a magnetic field with a magnetic flux density of at least 1 T. It is further proposed that the tensile element comprises at its second end a fastening attachment for fastening the tensile element to an external structure. The airbag can thus be easily integrated into a higher-level structure for automatic activation, wherein the tensile element automatically generates the tensile force in the tensile element required to release the lock and activate the cold gas generator or the airbag when the airbag moves relative to the attached second end of the tensile element due to the external attachment of the second end.

[0020] Furthermore, a vehicle with a restraint device with an airbag according to one of claims 1 to 8 is proposed for solving the task, in which the airbag comprises a person holder for fixing the airbag to a person siting on the vehicle, and the traction element is atached to the vehicle.

[0021] By carrying the airbag by the person to be protected and ataching the second end to the vehicle, a relative movement of the person to be protected in relation to the vehicle, which inevitably occurs in accidents, is used to deploy the airbag itself. This means that the airbag practically activates itself when the person moves relative to the vehicle, wherein the activation threshold and the direction of the movement of the person triggering the activation are defined by the design of the tension element and the atachment location of the second end.

[0022] The invention is explained below with reference to preferred embodiments with reference to the atached figures. It shows

[0023] Fig. 1 A vehicle according to the invention in the form of a motorcycle with a person siting on it with an airbag according to the invention in various positions of forward displacement; and Fig. 2 a cold gas generator with an actuator before activation; and

[0024] Fig. 3 the cold gas generator with the actuator during activation; and

[0025] Fig. 4 an enlarged view of the actuator as an individual part; and

[0026] Fig. 5 the actuator in various positions before and during activation.

[0027] Figure 1 shows a vehicle 100 according to the invention in the form of a motorcycle with a person 200 sitting on it, who is wearing an airbag 1 according to the invention, for example in the form of a vest. The vehicle envisaged here is a motorcycle, but it is also conceivable that the person 200 is siting on a bicycle, a scooter, a jet ski, a skibob or the like.

[0028] In the left-hand illustration a), the vehicle 100 with the person 200 can be seen before the airbag 1 is activated. The airbag 1 is designed as a vest and comprises a cushion 2 and an actuator 3 as basic elements, wherein the actuator 3 is arranged on the back of the person 200 in the deployed position of the airbag 1, and the cushion 2 covers a large part of the back, the shoulders and a part of the chest area. However, depending on the optimum restraint geometry for the person 200 to be protected, the cushion 2 can comprise any shape and also cover other parts of the body, such as the head in the form of a hood or side areas of the body.

[0029] As basic components, the actuator 3 comprises a housing 11 with an induction coil 5 arranged thereon and a magnet 4 displaceable in the housing 11. The magnet 4 is connected to a first end of a tension element 6, which is connected at its second end to the vehicle 100 in a tension-proof manner. For this purpose, the second end of the tension element 6 comprises a fastening atachment with which it can be fastened to a suitable counter attachment on the vehicle 100. The person 200 first puts on the airbag 1 and then attaches the second end of the tension element 6 to the vehicle, which practically puts the airbag 1 in a ready state.

[0030] If an accident occurs in this standby position of the airbag 1, as a result of which the person is accelerated relative to the vehicle, as can be seen in representations b) and c) of Figure 1, the tension element 6 is initially tensioned in a first phase. During the further movement of the person 200, the actuator 3 is then moved further relative to the magnet 4, wherein the magnet 4, which is blocked against this movement by the tensioned tension element 6, passes the induction coil 5.

[0031] This movement of the magnet 4 can also be seen in Figures 2 and 3 using two different positions of the magnet 4. In Figure 2, the position of the magnet 4 before the airbag 1 is activated can therefore be seen as shown in a) of Figure 1. The actuator 3 is connected via an electrical line 10 to a releasable closure 9 of a cold gas generator 8 of the airbag 1, which in turn is fluidically connected to the airbag 2 of the airbag 1. The actuator 3 also comprises a releasable blocking mechanism 7, which is arranged on the housing 11 in such a way that it fixes the magnet 4 in a predetermined position at a distance from the induction coil 5. The releasable blocking mechanism 7 can be seen in an enlarged view in Figure 4. As will be explained in more detail below, the releasable blocking mechanism 7 is designed in such a way that it blocks the magnet 4 with a predetermined holding force against movement in the direction of the induction coil 5.

[0032] If the pulling force in the tension element 6 increases to such an extent that the holding force exerted by the blocking mechanism 7 is exceeded, the magnet 4 is pulled through the induction coil 5, overcoming the holding force of the blocking mechanism 7. This generates a current pulse in the induction coil 5, which releases the releasable closure 9 of the cold gas generator 8 and activates the cold gas generator 8 to inflate the cushion 2. In the present embodiment example, the actuator 3 with the housing 11 and the induction coil 5 arranged thereon is pulled in relation to the magnet 4 blocked in the direction of this movement, but this is identical in result to pulling the magnet 4 by the actuator 3, since only the relative movement of the magnet 4 to the induction coil 5 or vice versa is important for generating the current pulse. The tensile force applied thus corresponds to the tensile force applied to the actuator 3 in this embodiment example.

[0033] The current pulse released when the magnet 4 passes through the induction coil 5 to release the closure 9 comprises a current intensity of 1.2 A in a time span of 2 ms, preferably 1.75 A in a time span of 0.5 ms. For this purpose, the magnet 4 comprises a magnetic field with a magnetic flux density of at least 1 T. Neodymium magnets have proven themselves as magnets 4 in the experiments. For the induction coil 5, a winding of an insulated copper wire with a diameter of 0.4 mm in at least 1000 turns with an inner diameter of 20 mm and a length of the induction coil 5 in the axial direction of 40 mm has proved to be useful.

[0034] Figure 4 shows an enlarged section of the actuator 3 with the magnet 4 and the releasable booking mechanism 7. A steel plate 16 is provided on the housing 11, to which the magnet 4 is additionally fixed by exerting its magnetic force. This facilitates assembly and the magnet 4 can be held in position relative to the housing 11 in a generally simplified manner. The releasable blocking mechanism 7 comprises a spring 15, a first end of which rests against an annular disk 12 and a second end of which is supported on the housing 11 in an axial direction. Two rod-shaped locking elements 13 are located on the side of the annular disk 12 facing away from the spring 15, each of which is guided in guide contours 14 extending obliquely outwards. The sides of the locking elements 13 facing away from the annular disk 12 rest against the end face of the magnet 4, so that they block the magnet 4 against movement in the direction of the induction coil 5 to be added in the illustration of figure 4. The locking element 13 is spring-loaded against the magnet 4 by the spring 15 via the annular disk 12. The first end of the tension element 6 is connected to the magnet 4, wherein the tension element 6 extends between the blocking elements 13, through the annular disk 12 and the spring 15 to the outside. The holding force exerted on the magnet 4 by the releasable blocking mechanism 7 defines the minimum tensile force to be applied via the tension element 6 to activate the airbag 1 or, conversely, the tensile force to be applied to the actuator 3 when the magnet 4 is blocked to activate the airbag 1. If the magnet 4 is in contact with a steel plate 16 and is therefore additionally held by its own magnetic force, the holding force to be overcome results from the sum of the holding force of the blocking mechanism 7 and the magnetic force between the magnet 4 and the steel plate 16. The spring 15 is a compression spring in the form of a spiral spring with annular coils on an identical diameter, through which the tension element 6 extends.

[0035] Figure 5 shows the releasable locking mechanism 7 with the magnet 4 in various positions. Figure a) shows the position of the magnet 4 before the airbag 1 is activated, i.e. corresponding to Figure la), Figure 2 and Figure 4. The magnet 4 is in contact with the steel plate 16 and is blocked against movement in the direction of the induction coil 5 to be added by the spring-loaded locking elements 13, which are in contact with the end face of the magnet 4. If a tensile force is now exerted via the tension element 6 or via the actuator 3, which exceeds the holding force of the blocking mechanism 7 and the magnetic force between the steel plate 16 and the magnet 4, the magnet 4 is displaced in the direction of the arrow in diagram b) or the actuator 3 with the housing 11, the blocking mechanism and the induction coil 5 is displaced against the direction of the arrow. This relative movement displaces the locking elements 13 in the guide contour 14 radially outwards. At the same time, the annular disk 12 is displaced in the direction of the induction coil 5 to be added via the locking element 13 by compressing the spring 15 or, conversely, the induction coil 5 is displaced in the direction of the annular disk 12. The locking elements 13 are displaced outwards until they are in contact with the radial outside of the magnet 4 and the magnet 4 can be displaced further between the locking elements 13 by the annular disk 12 and the spring 15, as can be seen in the illustration c) of Fig. 5. When the actuator 3 is moved, the housing 11 would be displaced further with the annular disk 12 and the spring 15 over the stationary magnet. This removes the blocking of the magnet 4 and the magnet 4 can be pulled by the induction coil 5 in the further movement to generate the necessary current pulse or, conversely, the actuator 3 can be moved with the induction coil 5 over the magnet 4. The current pulse required to release the closure 9 is generated on the basis of the law of electrical induction, which is then transmitted via the electrical line 10 to the closure 9 to release it. If the current pulse is to be increased, this can be done by increasing the number of turns of the induction coil 5, by using a magnet 4 with a higher magnetic flux density or by increasing the relative speed of the magnet 4 to the induction coil 5.

[0036] According to the invention, the holding force of the blocking mechanism 7 alone is sufficient to hold the magnet 4 in the deactivated state of the airbag 1. However, the holding force can be supported by the magnetic force between the steel plate 16 and the magnet 4.

[0037] The invention was described with reference to an application of the airbag I on a person 200 siting on a motorcycle. However, it is also conceivable to use the airbag 1 to protect persons 200 on other vehicles 100, provided that the persons to be protected comprise a fixed spatial reference to the vehicle 100, so that the tension element 6 can be atached to the vehicle 100 accordingly and a movement of the person 200 deviating from the normal position of the person 200 can be used to activate the airbag 1.

[0038] Furthermore, the airbag 1 according to the invention can also be used to rescue persons, e.g. as a buoyancy aid or to create free space. In this case, the airbag 1 can be positioned accordingly and triggered manually by pulling on the tension element 6. Such buoyancy aids can be used, for example, by skiers who have been caught in an avalanche. Furthermore, the airbags 1 can be used, for example, to rescue injured persons by positioning the airbags 1 in corresponding constrictions and enlarging the constrictions accordingly by activating the airbags 1 and inflating the cushions 2. List of reference symbols

[0039] 1 Airbag

[0040] 2 Cushion

[0041] 3 Actuator

[0042] 4 Magnet

[0043] 5 Induction coil

[0044] 6 Tension element

[0045] 7 Blocking mechanism

[0046] 8 Cold gas generator

[0047] 9 Closure

[0048] 10 Electrical line

[0049] 11 Housing

[0050] 12 Annular disk

[0051] 13 Locking element

[0052] 14 Guide contour

[0053] 15 Spring

[0054] 16 Steel plate

Claims

Claims:

1. Airbag (1) with-a cushion (2),-a cold gas generator (8) which is fl uidica lly connected to the cushion (2) and which is filled with a pressurized gas, wherein-the cold gas generator (8) comprises a closure (9) which can be released by an electrical current pulse, wherein-when activated by releasing the closure (9), the cold gas generator (8) abruptly releases the pressurized gas into the cushion (2), thereby inflating the cushion (2), and-an actuator (3) for releasing the closure (9), characterized in that-the actuator (3) comprises an induction coil (5) and a magnet (4) connected to a first end of a tension element (6), and-a releasable blocking mechanism (7) is provided, which fixes the magnet (4) relative to the induction coil (5) in a predetermined position with a defined holding force, wherein -the magnet (4) is fixed relative to the induction coil (5) by exerting a tension force on the tension element (6) which exceeds the holding force of the blocking mechanism (7), or -the induction coil (5) can be displaced relative to the magnet (4) by exerting a tensile force on the actuator (3) which exceeds the holding force of the blocking mechanism (7), thereby generating the current pulse in the induction coil (5) required to release the fastener (9).

2. Airbag (1) according to claim 1, characterized in that-the actuator (3) comprises a housing (11) to which the induction coil (5) is attached, and -the housing (11) comprises a guide for the magnet (4), which is designed in such a way that the magnet (4) executes a movement through the induction coil (5) during the displacement movement.

3. Airbag (1) according to claim 2, characterized in that-a steel plate (16) is provided on the housing (11), to which the magnet (4) is fixed by its magnetic attraction force against the tensile force exerted by the tension element (6).

4. Airbag (1) according to any one of claims 1 to 3, characterized in that-the blocking mechanism (7) comprises a locking element (13) which is loaded by a spring(15) and fixes the magnet (4) in the predetermined position, and-the force exerted by the spring (15) on the locking element (13) defines the holding force exerted on the magnet (4).

5. Airbag (1) according to claim 4 with reference back to any one of claims 2 or 3, characterized in that-a guide contour (14) is provided on the housing (11), in which the blocking element (13) is guided in a movement from a blocking position into a release position.

6. Airbag (1) according to any one of claims 1 to 5, characterized in that-the current pulse comprises a current intensity of 1.2 A in a time span of 2 ms, preferably of 1.75 A in a time span of 0.5 ms.

7. Airbag (1) according to any one of claims 1 to 6, characterized in that-the magnet (4) comprises a magnetic field with a magnetic flux density of at least 1 T.

8. Airbag (1) according to any one of claims 1 to 7, characterized in that-the tension element (6) comprises at its second end a fastening attachment for fastening the tension element (6) to an external structure.

9. Vehicle (100) with a restraint device with an airbag (1) according to any one of claims 1 to8, characterized in that-the airbag (1) comprises a person holder for fixing the airbag (1) to a person (200) seated on the vehicle (100), and-the tension element (6) is attached to the vehicle (100).

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