RU2803356C1 - Airbag - Google Patents

Abstract

FIELD: airbags.

SUBSTANCE: safety devices with an inflatable shell, such as an airbag, intended for installation in vehicles, in particular, in the area of driver seats, passengers in the cabin of a car, aircraft. The airbag contains an airbag 15, an inertial mechanical emergency sensor made in the form of a spring-loaded spool valve 3, mounted for movement in the guide cylinder 1, a container 14 with compressed gas containing exhaust channels 2. The spring-loaded inertial body 4 of the mechanical emergency sensor is located inside the spring-loaded spool valve 3, which covers the outlet channels 2, and in the initial state, the movement of the spring-loaded inertial body 4 is additionally limited by the conical stop 7, made in the internal cavity of the flow divider 8, or on the spool valve 3, in which is supported, for example, by spring-loaded balls 5 installed in the inertial body 4.

EFFECT: eliminating the use of explosives and reducing the time required to fill the airbag.

10 cl, 7 dwg

Description

The invention relates to safety devices with an inflatable shell, such as an airbag, intended for installation in vehicles, in particular, in the area of driver seats, passengers in the cabin/cabin of a car, aircraft.

In its most general form, an airbag-type safety device comprises a gas-inflated shell having an inlet for gas to enter it, and a system for supplying a gas flow to the shell, including a gas source, a channel connecting the shell inlet to the gas source, and a launch unit. recording a vehicle accident and sending a signal to create a gas flow from the gas source into the shell.

During normal operation of the vehicle, the shell is located in a folded position in the area of the passenger or driver's seat, for example in the steering wheel or in the instrument panel in front of the passenger. In the event of an accident, according to a signal from the sensor, the shell must be inflated to a ready state in an average of 40 ms. At the same time, the inflated shell protects a person from impacts, shocks, etc., limiting his movements inside the vehicle.

In known safety devices, a compressed gas reservoir or a pyrotechnic gas generator containing a solid substance, the combustion of which produces gas, is used as a gas source in the gas flow supply system. It is also known to use combined gas sources, including compressed gas and a pyrotechnic gas generator.

Pyrotechnic gas generators are widely used in safety devices such as airbags, for example, RU 2152883. However, their use has the disadvantage that hot gas enters the shell, which can cause burns or at least discomfort to the person being protected. In addition, the generated gas is toxic and, simultaneously with the activation of the safety device, forced ventilation must be turned on to remove toxic gas from the cabin.

In addition, reuse of the safety device requires the installation of a new pyrotechnic gas generator, which increases the cost of operating the safety devices.

The use of a compressed gas reservoir as a gas source in safety devices eliminates the possibility of burns and poisoning.

However, in known safety devices of this type, the supply of gas flow into the shell is mainly due to the destruction of a fragile membrane, which is a rapid exhaust valve, closing the flow area of the channel between the compressed gas reservoir and the inlet of the shell before the safety device is activated (US 5152550 B1). The destruction of the membrane is accompanied by the appearance of many fairly sharp fragments, which, if they enter the shell, can damage it and cause injury to a person. To prevent debris from entering the shell, a filter is installed in front of the shell inlet. However, the filter increases the hydraulic resistance in the inlet of the casing and slows down the filling rate.

In addition, to reuse this type of safety device, it is necessary to replace the membrane or the entire gas flow system, which requires special qualifications from the person performing such replacement and increases the cost of operating the safety device.

Known safety features include inflatable restraints, such as a crash pad, which are designed to absorb the impact of a user in a vehicle crash and are located on the steering wheel hub to protect the driver and on the dashboard under the windshield or in the backrests of the front seats to protect passengers. An inflatable barrier device typically operates from a fast-acting gas source, bottled, generator, or other type. An emergency sensor is used to activate the gas source at the required time, and a battery installed on the car is most often used as a power source.

Passive safety systems with such protective devices require complex electronic devices, both in their composition and as part of diagnostic tools, which leads to certain difficulties in the design layout of system elements on a vehicle and to a decrease in the reliability of the entire system.

The closest analogue (prototype) to this invention is an inflatable protective device according to patent RU 1729062, containing a guide cylinder, an inertial mechanical emergency sensor, made in the form of an inertial mass installed with the ability to move inside the guide cylinder, a fast-acting gas source, a trigger mechanism, including includes a deformable fuse installed between the inertial mass and the body, a striker and a sensing organ, and an inflatable cushion filled from a fast-acting gas source associated with an inertial mechanical emergency sensor, wherein the housing is made sealed and communicates with the inflatable cushion, the guide cylinder is made in one integral with the body, the inertial mass is a container with a fast-acting gas source, a striker rigidly mounted on it, connected by means of a sensing body to the outlet valves of the gas source, and a guide that encloses the container with the gas source and ensures sliding inside the guide cylinder. The disadvantages of the prototype are the difficulty of placement in existing vehicle structures, the presence of movable sealed joints, which reduces the reliability of the structure.

The purpose of the invention is to eliminate the shortcomings of the prototype, as well as the ability to set the airbag activation parameters in a wide range, reducing the time for bringing the airbag into working condition after reaching the criteria specified by the car developer for airbag activation, i.e. the range of values of the factors that determine the non-deployment and activation of the device in an accident, as well as the ability to integrate the airbag into existing designs of the steering wheel, front panel, etc. The elimination of explosives increases operational safety, and the reduction in response time reduces the number of driver injuries even when the seat belt is not fastened.

An airbag containing an inflatable cushion, an inertial mechanical emergency sensor made in the form of a spring-loaded inertial body mounted with the ability to move in a guide cylinder, a container with compressed gas containing exhaust channels, while the spring-loaded inertial body of the mechanical emergency sensor is located inside a spring-loaded spool a valve blocking the exhaust channels, and the movement of the spring-loaded inertial body is limited by a protrusion associated with the spool valve. This design allows the inertial body to accumulate energy and, upon impact with the protrusion associated with the spool valve, move the spool valve by an amount sufficient to begin opening the output channels, taking into account the duration of the overload without the use of explosives and an electronic control unit.

The inertial body contains locking elements that hold it in its original position until a given axial overload is exceeded, for example, due to the interaction of spring-loaded balls with a stop made in the form of a conical section, for example, inside a compressed gas flow divider. This design makes it possible to increase the energy stored by the inertial body, since the movement of the inertial body occurs at a greater overload, after exceeding the minimum specified overload, and the accuracy of the start of the process of starting the inertial emergency sensor mechanism.

Making the stop in the form of a conical section, with which the spring-loaded balls interact, directly on the spool valve allows, when a negative overload of about 40 g occurs, to sharply reduce the airbag response time by eliminating the time of movement of the inertial body before colliding with the stop associated with the spool valve, since in this In this case, the spool valve is affected not only by an overload, but also by an inertial body through spring-loaded balls acting on a stop in the form of a conical section made on the spool valve itself (this overload can be partially reduced by increasing the mass of the spool).

The amount of movement of the inertial body is 8...12 times greater than the movement of the spool valve before the opening of the exhaust channels begins, i.e., the force acting on the spool valve increases by approximately the same amount when the inertial body collides with the protrusion associated with the spool valve. This force is sufficient to overcome the friction forces of the sealing rings on the inner surface of the guide cylinder and the resistance of a strong spring, since the energy stored by the inertial body is only needed to open the spool valve slightly, and its further opening occurs due to the rapid increase in pressure in the cavity limited by the inertial body with the valve blocked by the central hole, the spool valve and the sealed partition made in the flow divider, since this cavity has a small volume, the pressure in this cavity increases sharply to the rupture pressure of the sealed partition, which also acts on the end of the inertial body and the spool valve, which move behind time is less than 1 ms, the exhaust windows are fully opened, while the filling time of the air cushion is sharply reduced; energy accumulation is also facilitated by the presence of a central hole in the inertial body, which reduces air resistance as it moves inside the spool valve.

The presence in the compressed gas flow divider of a sealed partition, on which a notch is made, consisting of radial and annular sections, ensures the stability of its rupture at a certain given pressure by changing the depth of the notch, and the intermittency of the concentric sections does not allow the sectors of the destroyed bridge to tear away from the flow divider, i.e. .e. prevents them from getting inside the air cushion and, as mentioned above, the presence of a sealed partition sharply reduces the opening time of the exhaust channels.

The presence of a threaded connection between the divider and the guide cylinder ensures reliable fastening of the air cushion to the container with compressed gas, and the radial channels made in the divider are located inside the air cushion, ensuring reversal and softening of the jet of compressed gas leaving the container.

The spool valve contains annular grooves with sealing rings made of a low-friction material, for example, fluoroplastic-4, and the small distance from the sealing ring to the beginning of the outlet channels, approximately 1.5 ... 2 mm, reduces the required energy to move the spool valve valve before the opening of said exhaust ports begins. The location of the outlet channels between two sealing rings ensures the tightness of the compressed gas container.

The presence of a locking ring, made in the form of, for example, a solid rim with radial protrusions, and the diameter of the inscribed circle of these protrusions is slightly smaller than the outer diameter of the spool valve, as well as an annular protrusion made at the end of the inner surface of the guide cylinder, ensure fixation of the spool valve in the open position exhaust channels and prevent their spontaneous overlap. The fixing ring can also be made in the form of a split ring, the inner diameter of which is less than the outer diameter of the spool valve by an amount that provides a wedge angle after the spool valve enters it.

At the end of the guide cylinder, in which the outlet channels are made, a cap made of elastic material, for example, rubber, is installed, which practically seals the cavity with the inertial body, excluding its contamination and moisture ingress into this cavity, and the cap is pierced with a needle, and if it swells from a small the amount of flowing gas does not affect the performance of the airbag, then the punctured hole opens and excess gas escapes through this hole, after which the seal of the cap is restored.

The container with compressed gas is rigidly connected to the chamber in which the inflatable cushion is placed. This design makes it possible to tear the panel along special hubs and keep the panel itself in its original state.

In fig. 1 shows a longitudinal section of an airbag installed in the steering wheel of a vehicle.

In fig. Figure 2 shows an enlarged view of the spring-loaded fixing elements resting against the flow divider.

In fig. 3 shows an enlarged view of the spring-loaded retaining elements resting on the spool valve.

In fig. Figure 4 shows a longitudinal section of an airbag installed in the front panel.

In fig. Figure 5 shows a valve closing a hole in the inertial body.

In fig. Figure 6 shows a partition with flow divider notches.

In fig. Figure 7 shows a graph showing the dependence of the response time of the airbag after reaching the specified parameters on the speed at which the vehicle collides with a rigid obstacle.

The airbag contains a guide cylinder 1 (Fig. 1-4) with exhaust channels 2, inside which there is a spool valve 3, and inside the spool valve 3 there is an inertial body 4, which is held in its original position, for example, by balls 5, spring-loaded springs 6, which in turn interact with the conical surface 7, made either inside the flow divider 8, or on the spool valve 3 itself, in which the stop 9 is made (Fig. 1 and 4). A weak spring 10 (Fig. 1 and 4) is installed between the stop 9 and the inertial body 4 (Fig. 1-4), and between the spool valve 3 (Fig. 1-4) and the retaining ring 11 (Fig. 1 and 4) strong spring 12. On the side of the strong spring 12, the guide cylinder 1 (Fig. 1-4) is closed with a cap 13 (Fig. 1 and 4) made of elastic material. The guide cylinder 1 (Fig. 1-4) passes through the container 14 (Fig. 1 and 4) with compressed gas and from the side of the inflatable cushion 15 (shown schematically) is closed by a flow divider 8 (Fig. 1-4), which, using a threaded The connection fixes the inflatable cushion 15 (Figs. 1 and 4) on the container 14 with compressed gas, while the radial channels made on the flow divider 8 (Figs. 1-4) are located inside the inflatable cushion 15 (Figs. 1 and 4). The flow divider 8 (Fig. 1-4) contains a sealed partition 16, on which a notch is made, consisting of radial 17 (Fig. 6) and annular 18 sections. Spool valve 3 (Fig. 1-4) contains grooves into which sealing rings 19 are installed, made mainly of fluoroplastic-4.

The airbag 15 (Fig. 1 and 4) in the folded state is located in the cavity formed by the container 14 with compressed gas and the cover 20 (Fig. 1) of the driver's airbag, attached to the container 14 using a clamp 21, and in the passenger airbag there is an inflatable the pillow 15 (Fig. 4) is also located between the container 14, fixed through brackets 22 to the frame of the car (not shown in Fig.), and the panel 23, attached to the front panel of the car (not shown in Fig.), while the brackets 24, rigidly connected to the container 14, pass through the windows made in the panel 23.

On the container 14 (Fig. 1) of the driver's airbag there are clips 25 installed, which fit into special holes made in the steering wheel niche, hooks 26 connected to spring latches also located inside the steering wheel niche (not shown in the Fig.), a board 27 made of dielectric with contacts 28 of the sound signal and springs 29, a check valve 30 for pumping and pumping the tank 14, and a strain gauge (not shown in the figure) of the gas pressure in the tank 14, glued to this tank, with the output of electrical wires together with the wires of the sound signal, which allows you to install an airbag in the steering wheel without significant modification, and brackets 22 (Fig. 4) rigidly connected to the container 14 allow you to install a passenger airbag in a car without an intermediate bracket and use the existing panel 23, since the container 14 with compressed gas serves as the power part this bracket.

In the inertial body 4 (Fig. 1-4) there is a central hole 31, which is blocked by a valve 32 (Fig. 1-5), the side part of which is rigidly connected to the inertial body 4 (Fig. 1-4), for example, with glue .

The device works as follows.

In frontal and close collisions, during the deformation of the car, the negative acceleration module of the car increases, and when it reaches its specified value, at which the airbag should operate, the radial movement of the balls 5 (Fig. 1-4) occurs towards the central hole, spring-loaded 6, releasing the inertial body 4, which, under the influence of inertial forces, deforms the weak spring 10 (Fig. 1 and 4) (the force of the weak spring must be sufficient to return the inertial body 4 to its original position after a false start, overcoming the friction forces of the inertial body 4 and balls 5 on the inner surface of the spool valve 3), accelerates, storing kinetic energy and upon impact with the stop 9 associated with the spool valve 3 (Fig. 1-4), moves it by an amount sufficient to begin opening the exhaust channels 2, while compressed gas from container 14 (Fig. 1 and 2) enters the cavity limited by the inertial body 4 (Fig. 1-4), the spool valve 3 and the sealed partition 16. Keeping the inertial body 4 in its original position is also possible, for example, due to constant magnet (in Fig. not shown), rigidly connected to the sealed partition 16, and in the initial position in contact with the inertial body 4, etc. Due to the small volume of the formed cavity in it, in a time of less than 1 ms, the pressure increases to a value approximately equal to half the pressure of the compressed gas in the container 14 (Fig. 1 and 2), which is also achieved by blocking the central hole 31 (Fig. 1- 4), which serves to reduce air resistance when moving the inertial body 4, by valve 32 (Fig. 1-5). This pressure is sufficient to rupture the sealed partition 16 (Fig. 1-4), along notches in the form of radial 17 (Fig. 6) and annular 18 sections. The maintained excess pressure in the above-mentioned cavity until the sealed partition 16 ruptures (Fig. 1-4) is sufficient for rapid (in less than 2 ms) movement of the spool valve 3 until the turns of the strong spring 12 close (Fig. 1 and 4) (force of the strong spring 12 should be sufficient to return the spool valve 3 to its original position after a false start by an amount insufficient to begin opening the spool valve 3) and bending the petals of the locking ring 11, which do not allow the spool valve 3 (Fig. 1-4) to return to its original position , thereby leaving the exhaust channels 2 open. The compressed gas through the destroyed sealed partition 16, hitting the bottom of the flow divider 8, exits through its radial channels, while the excess pressure that has arisen in the cavity between the container 14 (Fig. 1 and 4) with compressed gas and the lid 20 (Fig. 1) leads to to the rupture of the latter through special concentrators made in it and further filling of the volume of the air cushion 15. Since the area of the output channels 2 and radial channels in the flow divider 8 is more than 500 mm ² , the filling of the air cushion 15 occurs in less than 9 ms. In a similar way, the destruction of the panel 23 (Fig. 4) and the deployment of the passenger airbag 15 occurs.

A design option is also proposed in which balls 5 (Fig. 1-4), spring-loaded by spring 6 (Fig. 1 and 4) rest against stop 7 made directly on the spool valve. This makes it possible, with an overload of approximately 40 g, to ensure accelerated response, since the overload acts simultaneously on both the spool valve 3 (Fig. 3 and 4) and on the inertial body 4, which has not yet disengaged from the spool valve 3, which allows the outlet channels 2 to open faster without wasting time on moving the inertial body 4 until it hits the stop 9 (Fig. 1 and 4) connected to the spool valve 3 (Fig. 1-4). This, in turn, reduces the activation time of the airbag by approximately 15 ms when an overload occurs that is several times greater than the specified one; in this case, it is no longer necessary to ensure the specified overload duration of approximately 20 ms. At a given minimum overload of 5...8 g, set to activate the airbag, both the driver and passenger in an emergency move relative to the car much more slowly, and the time before the inertial body 4 collides with the stop 9 (Fig. 1 and 4) associated with the spool valve 3, which is approximately 20 ms, which is already required to prevent false activation of the airbag, for example, in a collision with a post, a fairly thin tree, where the overload will be sufficient, but its action time is not enough and the airbag should not be triggered. . In this situation, spring 10 will return the inertial body 4 to its original position, and spring 12 will return the spool valve 3 to its original position. In the version where the stop 7 (Fig. 1-4) is made on the flow divider 8, accelerated operation is also possible, but the overload should be much greater, since only the mass of the spool valve 3 is involved in the accelerated opening.

The presence of a strain gauge glued to the container 14 (Figs. 1 and 4) makes it possible to monitor the pressure drop in the container 14 below the permissible level at the current time, and the presence of a check valve 30 allows for timely pumping of the container 14 with compressed gas, for example, nitrogen.

The inflatable cushion 15 can be made from lighter fabric, for example, from parachute silk with a surface density of 47 g/ ^m2 , because it is not affected by hot gases, and due to the released volume, the volume of the container 14 with compressed gas can be increased, which allows reducing the pressure it contains up to 25 atm. In this case, the container 14 with compressed gas will no longer be classified as a high-pressure container.

The tilt of the steering wheel, which is approximately 18-24 degrees, has little effect on the performance of the inertial mechanical emergency sensor, since, for example, with a negative overload in a car collision equal to 6g, the inertial body will move in the hole of the spool valve 3 at an angle of inclination of 9.5 degrees, practically without friction, at a double angle of 19 degrees, the friction force of the inertial body 4 will be the same as when the spool valve 3 is horizontal, but the inertial body 4 will be pressed against the top of the inner surface of the hole in the spool valve 3. Slight deviation of the steering wheel tilt relatively 19 degrees has little effect on the operation of the mechanism, as does a non-direct impact of the car on an obstacle, not exceeding 30 degrees.

The dependence of the response time of the airbag after reaching the specified parameters (with the parameters of the inertial mechanical sensor given below is 6.2 g and the delay time is 20 ms) in milliseconds on the speed of the collision of the car with a rigid obstacle in km/h is shown in the graph (Fig. 7). To obtain the curve shown in the graph, the following parameters of the inertial mechanical airbag crash sensor were used:

Large spring preload force: 20 N

Stroke of a strong spring to complete deformation: 0.017 m

Pre-deformation of strong spring: 0.05m

Deformation before the spool valve begins to open: 0.002 m

Gas pressure in the tank: 5000000 Pa

Small O-ring diameter: 0.00064 m

Large O-ring diameter: 0.029m

Proportion of the diameter that determines the contact width: 0.6

Number of seals: 2

Friction set in seals: 0.2

Vehicle speed: from 0 to 50 m/s

Vehicle stiffness: 1,000,000 N/m

Vehicle weight: 2153 kg

Steering wheel angle: 20 degrees.

Load stroke: 0.02 m

Load friction set: 0.2

Load weight: 0.15 kg

Spool valve weight: 0.048 kg

Average ball spring force: 2N

Ball contact angle: 55 degrees.

Ball friction set: 0.2

Weak spring force: 1 N

Small spring stroke: 0.02 m

Small spring pre-deformation: 0.05 m

Spool valve window width: 0.0093 m

Spool valve window height: 0.0135 m

Number of windows: 4

Cylinder volume: 0.0006 ^m3

Volume of the cavity limited by a sealed partition: 0.00001 m ³

Volume of the cavity limited by the panel: 0.0002 ^m3

Airbag volume: 0.03 ^m3

Spool valve diameter: 0.029 m

Atmospheric pressure: 100000 Pa

Normal density: 1.25 kg/ ^m3

Diaphragm burst pressure: 3000000 Pa

Panel burst pressure: 1200000 Pa

Residual pressure in the cushion: 500000 Pa

Adiabatic index: 1.4

Time sampling value 0.0001 s

The graph shows zone I up to 15 km/h, where the airbag should not deploy. Zone II shows where triggering must necessarily occur. Transition zone III from 15 to 25 km/h, where the airbag may or may not deploy. Based on the calculation, it can be argued that this zone can be significantly reduced. By changing the above parameters of the inertial mechanical emergency sensor, you can vary the parameters of both the minimum overload and the minimum time required for the airbag to deploy.

Claims (10)

1. An airbag containing an airbag (15), an inertial mechanical emergency sensor made in the form of a spring-loaded inertial body (4) installed for movement in the guide cylinder (1), a container (14) with compressed gas containing exhaust channels (2), characterized in that the spring-loaded inertial body (4) of the mechanical emergency sensor is located inside the spring-loaded spool valve (3) covering the outlet channels (2), and the movement of the spring-loaded inertial body (4) is limited by the protrusion (9) associated with spool valve (3). 2. The pillow according to claim 1, characterized in that the inertial body (4) contains locking elements that hold it in its original position until a given axial overload is exceeded, for example, due to the interaction of spring-loaded balls (5) with a stop (7) made in in the form of a conical section, for example, inside a compressed gas flow divider (8). 3. The pillow according to claim 2, characterized in that the stop (7), made in the form of a conical section, with which the spring-loaded balls (5) interact, is made on the spool valve (3). 4. The pillow according to claim 1 or 2, characterized in that the amount of movement of the inertial body (4) is 8...12 times greater than the movement of the spool valve (3) before the opening of the exhaust channels (2), and the inertial body (4) contains a central hole (30) closed by valve (31). 5. The pillow according to claim 2, characterized in that the compressed gas flow divider (8) contains a sealed partition (16), on which a notch is made, consisting of radial (17) and annular (18) sections. 6. A pillow according to claim 2 or 5, characterized in that the flow divider (8) is installed with the possibility of attaching an inflatable pillow (15) to a container (14) with compressed gas, and the radial channels made in the flow divider (8) located inside the air cushion (15). 7. The pillow according to claim 1 or 4, characterized in that the spool valve (3) contains annular grooves with sealing rings (19), and the distance G from the sealing ring to the beginning of the outlet channels (2) is 1.5...2 mm, and said outlet channels (2) are located between the sealing rings (19). 8. The pillow according to claim 1, characterized in that at the end of the guide cylinder (1) a ring (11) is installed with the ability to fix the spool valve (3) in the position of open exhaust channels (2). 9. A pillow according to claim 1, characterized in that a cap (13) made of an elastic material, for example, rubber, is installed at the end of the guide cylinder (1), in which the outlet channels (2) are made. 10. A pillow according to claim 1, characterized in that the container (14) with compressed gas together with the lid (20) or panel (23) forms a cavity into which the inflatable pillow (15) is placed, and the container (14) with the lid ( 20) the driver's airbags are fixed to each other using a clamp (21) and special depressions made on the container (14) and corresponding protrusions made on the cover (20), and the passenger airbag container (14) is additionally fixed using brackets (24 ), welded to the container (14), entering the holes made in the panel (23).