FR3055857A1 - PYROTECHNIC GAS DISPENSER AND CORRESPONDING PUERICULTURE DEVICE - Google Patents

Abstract

Gas distributor for inflatable cushion (s) of a childcare device, characterized in that it comprises a gas inlet under pressure, able to be placed in communication with a tank containing a gas under pressure, a chamber detent reducing the pressure of said gas, and at least one gas outlet, adapted to be placed in communication with an airbag.

Description

The Holder of this patent application has described, in document W02016116308, a pyrotechnic gas generator suitable for childcare devices.

Such a gas generator for airbag (s) comprises in particular: at least one pyrotechnic charge and means for igniting / activating said charge triggered during a predetermined condition, a tank containing a gas under pressure and the mouth of which is closed by a closure element, and a gas discharge opening communicating with at least one airbag.

The gas generator further comprises a striker located in a conduit into which the gas discharge opening opens and which can be moved initially, when the predetermined condition is fulfilled, by the combustion gases generated by the charge. pyrotechnic in the direction of the shutter element, from an initial position to an open position, so as to pierce the latter by means of piercing means carried by said striker, said striker being able to be brought back, once the closing element pierced by the pressurized gas stored in the tank, towards the initial position, the pressurized gas escaping from the tank towards said gas discharge opening.

It is thus possible to supply an inflation gas to one or more airbags reliably using a gas generator structure which is simple and compact.

In addition, such a structure limits the deployment time of the airbags.

The pyrotechnic gas generator according to the invention uses a solid combustion gas production agent, as a source of movement of a striker towards a cylinder of pressurized gas. A front end of the striker is used to pierce the closing cap of the pressurized gas cylinder.

Once the bottle is pierced, the pressurized gas causes the striker to move in the opposite direction, the recoil of the striker allowing the pressurized gas to go towards a gas discharge orifice communicating with the airbag (s). The gas stored under pressure in the bottle is thus released to inflate / deploy the cushion (s).

Such a gas generator structure also has a reduced weight.

However, the communication between the tank and the airbag (s) is not covered in this document. This aspect is essential, however, because it is necessary to efficiently relax the gas, to bring it to a pressure, speed and / or flow rate suitable for inflating the cushion (s), in particular by avoiding the formation of carbon dioxide snow, when the gas contains CO ₂ .

Important constraints are also to be taken into account, with regard to the weight, size and solidity, in view of the particular constraints of a car seat, or of similar equipment, in particular the respect of the structure and the small space.

The invention particularly aims to provide a solution to at least some of these aspects.

This is achieved, according to the invention, using a gas distributor for airbag (s) of a childcare device, characterized in that it comprises a pressurized gas inlet, suitable to be placed in communication with a reservoir containing a pressurized gas, an expansion chamber reducing the pressure of said gas, and at least one gas outlet, capable of being placed in communication with an airbag.

According to a particular embodiment, the gas distributor comprises two gas outlets, each supplying an airbag.

In this case, said gas inlet, said expansion chamber and / or said gas outlets are advantageously configured so as to distribute substantially the same quantity of gas between the two airbags.

In particular, said expansion chamber can carry at least one switching element capable of directing the gas substantially homogeneously towards the two outlets.

In particular, the gas distributor may comprise at least one deflector placed in the upper part and oriented substantially along the axis of said gas inlet.

According to a particular embodiment, said gas inlet forms an angle of less than 90 ° with said tank.

According to a particular embodiment, the gas distributor comprises means for securing said tank.

According to a particular embodiment, the gas distributor carries at least one pyrotechnic charge and means for igniting / activating said charge triggered during a predetermined condition, to ensure the opening of said tank.

According to a particular embodiment, said expansion chamber ensures a passage from a pressure of substantially 30 bars at the level of said gas inlet to substantially 1 bar at the level of the gas outlet (s).

According to a particular embodiment, said expansion chamber is made of polyamide reinforced with glass fiber.

According to a particular embodiment, the gas distributor is dimensioned and configured to be housed in a car seat backrest.

The invention also relates to childcare devices capable of receiving a child comprising at least one gas distributor as described above.

According to a particular embodiment, this child care device comprises a harness having two suspenders intended to extend from the shoulders along the torso of a child, each of the suspenders carrying an inflatable safety element, capable of inflating in case of shock greater than a predetermined threshold.

According to a particular aspect of the invention, the childcare device comprises a seat, said gas generator being housed in the backrest, in at least one of the lateral flanks, and / or in the base of said seat.

Said inflatable safety elements can be supplied by at least one source of fluid, for example housed in the back of said seat, in the lateral sides, in the base, etc.

This childcare device can in particular be a car seat. According to other applications, it can also be a stroller, a carrycot, or a bicycle seat, for example.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment of the invention, given by way of simple illustrative and nonlimiting example, and of the appended drawings among which:

Figure 1 illustrates an example of a car seat using a pyrotechnic gas generator according to the invention intended to inflate inflatable elements carried by the harness of the car seat;

Figure 2 shows the car seat of Figure 1, the inflatable elements having been deployed;

Figure 3 shows the rear of the car seat of Figures 1 and 2, equipped with a pyrotechnic gas generator for inflating the inflatable elements;

Figures 4 to 9 illustrate the operation of the pyrotechnic gas generator;

FIG. 10 schematically illustrates an example of a striker tip used in the pyrotechnic gas generator; Figures 11 and 12 are two views showing an embodiment of a gas distributor according to the invention;

FIGS. 13, 14 and 15 are simplified views of the dispenser of FIGS. and 12, schematically illustrating the path of the gas;

Figures 16, 17, 18 and 19 illustrate the gas distributor on four sides, showing some of its dimensions;

Figures 20 and 21 are two sectional views of the gas distributor.

1. child car seat fitted with inflatable cushion (s)

The invention relates to childcare devices fitted with one or more airbags.

The embodiment described below relates to car seats for children. However, a person skilled in the art understands that the same approach can easily be adapted to other childcare devices, provided that they are equipped with one or more airbags.

As can be seen in FIG. 1, the child car seat 11 conventionally comprises a seat 111 and a backrest 112, here carrying a headrest 113, which can be movable in height, relative to the backrest 112.

The child is held in this seat 11 using a harness 12, comprising two straps 121 and 122, intended to be placed each on one of the shoulders of the child, and extending substantially vertically on the torso of this one, and a crotch leg 123.

When the harness is in place, the two shoulder straps 121 and 122 and the crotch leg 123 are secured by a locking loop 124. Each shoulder strap 121 and 122 carries a sheath 131, 132, coming to take position on the shoulders and / or the child's upper body, to improve comfort and safety.

In the embodiment described, each of these sleeves 131 and 132 contains an inflatable safety element 141, 142 (of which only one end is visible in FIG. 1, and protrudes from the sleeves). The rest of the inflatable safety elements are folded and housed in the sleeves, so that they can deploy effectively in the event of an impact. The ends of the inflatable safety elements 141, 142 are connected by securing means 15, securing them to one another, comprising two flexible portions, or straps, 151 and 152 each equipped with a buckle element respectively male and female.

In the event of a significant shock, above a predetermined threshold, the two inflatable safety elements 141 and 142 deploy automatically and very quickly, from the sleeves 131 and 132, in particular to protect the head of the child, and limit its travel towards the front, as shown in Figure 2.

2. gas generator

As described in the document W02016116308 mentioned above, the two inflatable safety elements 141 and 142 are supplied by inflation means in the form of a pyrotechnic gas generator 2, the operation of which is described below in relation to FIGS. 4 at 9.

As illustrated in FIG. 3, the gas generator 2 can be housed in the backrest 114 of the seat 11 in a housing provided for this purpose. This housing can, depending on the case, be placed in the back, seat or base of the car seat, or in any suitable location.

As illustrated in FIGS. 3 and 4, the gas generator 2 comprises a hollow body 22 comprising a horizontal cylindrical duct 221 into which there opens a duct, or opening, 222 for discharging the gases towards a gas distributor, described below . This conduit 222 is here cylindrical but may have other shapes. FIG. 4 shows the longitudinal axis A of the horizontal pipe 221 and the longitudinal axis B of the gas discharge pipe 222. These two axes A, B are here arranged at 90 °, but other values of inclination of the conduit 222 relative to the conduit 221 are possible. Thus, the gas discharge conduit 222 can be arranged obliquely to the longitudinal axis A of the horizontal conduit 221.

An open end of the horizontal pipe 221, located to the right of the gas discharge pipe 222, is intended to receive the neck of a cylinder 21 of a suitable fluid. The fluid contained in the cylinder may in particular be a gas such as carbon dioxide (CO ₂ ), helium, nitrogen, or any other fluid adapted to allow immediate inflation of the two inflatable safety elements 141, 142. The neck of the bottle can be screwed into the open end of the horizontal conduit 221.

A first end of a gas diffuser tube 26, which in this case is a flexible conduit, is connected to the fluid supply inlet (not shown) of the inflatable safety elements 141, 142, its second end being connected to the conduit 222 for removing the gases from the gas generator 2.

In addition to the gas reserve (gas bottle) 21, the gas generator 2 comprises a pyrotechnic assembly mounted in the other end of the horizontal pipe 221, located to the left of the pipe 222 for discharging the gases. This pyrotechnic assembly consists of a pyrotechnic (or explosive) charge 23, ignition means 25 of the pyrotechnic charge 23 and a striker 24, shown in FIG. 4.

The pyrotechnic charge 23 is in the form of a monolithic block of fuel (propellant for example) which produces gas by being ignited and burning. The pyrotechnic charge 23 is located in a combustion chamber 242 formed inside the striker 24, which makes it possible to limit the size of the gas generator 2. The combustion chamber 242 opens into the flat rear surface 244 of the striker 24 which is, in the position of FIG. 4, in contact with the ignition means 25.

The cylindrical striker 24 (also called ball) is movable in sliding in two opposite directions in the horizontal duct 221 and has, in this example, at the front, a bevelled tip 241 perforating (another shape can be envisaged, in particular a shape in a warhead) oriented towards the cylinder 21. The bevelled tip 241 comprises a surface inclined relative to the longitudinal axis A of the horizontal pipe 221 and oriented towards the pipe 222 for discharging the gases. The piercing tip 241 is surrounded by an annular collar 243.

In the initial position of FIG. 4, this perforating part 241 is situated opposite the conduit 222 for discharging the gases, at a distance from the cover 211 for closing the cylinder 21.

Although this is not illustrated in the figures, the gas generator 2 is controlled by a microcontroller / electronic control unit (ECU). If necessary (shock, accident, deceleration greater than a predetermined threshold, etc.), the microcontroller is capable of issuing a trigger instruction for the gas generator 2, in the form of an electrical signal which is transmitted to the means 25, so as to ensure the inflation of the two inflatable safety elements 141 and 142. The initiation of inflation during an impact must of course be done in the event of a sufficiently large impact. A suitable predetermined threshold is therefore defined.

If this predetermined threshold is exceeded, the ignition means 25 trigger the combustion of the pyrotechnic charge 23 in the combustion chamber 242. As illustrated by the arrow D1 in FIG. 5, once the combustion gas 231 fully occupies the volume of the combustion chamber 242, it causes the striker 24 to move in the horizontal conduit 221, towards the cylinder 21 (that is to say from left to right in FIG. 5).

In the position illustrated in FIG. 5, the end of the piercing part 241 of the striker 24 is in contact with the seal 211 for closing the carboy 21, and the combustion gas 231 is contained in the closed space located between the ignition means 25 and the striker 24.

In FIG. 6, the striker 24 has again moved towards the cylinder 21 under the effect of the combustion gas 231 and is in an open position. The rear surface 244 of the striker 24 is located opposite the conduit 222 for discharging the gases. The combustion gas 231 has escaped into the conduit 222 for discharging the gases communicating with the tube 26 and the airbags. The degassing of the pyrotechnic charge 23 therefore takes place towards the airbags. The perforating part 241 of the striker 24 has pierced the lid 211 for closing the cylinder 21 and is located in the neck of the cylinder

21. The flange 243 abuts against the neck of the cylinder 21, thus making it possible to keep the body of the striker 24 outside the cylinder 21 and the striker 24 to move back to direct the pressurized gas 211 towards the airbags.

The cylinder 21 being open and the combustion gas 231 being purged, as illustrated in FIG. 7, the pressurized gas 211 stored in the cylinder 21 applies sufficient pressure P to the perforating part 241 of the striker 24 to cause the latter to retreat into the horizontal conduit 221 (that is to say to move it in the opposite direction, from the cylinder 21 to the ignition means 25). As the striker 24 moves back to its initial position (as illustrated by the arrow D2 in FIG. 8), the gas under pressure coming from the cylinder 21 is directed into the conduit 222 for discharging the gases and inflates the airbags .

Thus, under the effect of the pressurized gas 211, the striker 24 moves back to a position for guiding the pressurized gas 211 to release the pressurized gas 211 in the conduit 222 for discharging the gases (FIG. 8).

In FIG. 9, the striker 24 has retreated to its initial position and the gas under pressure 211 is directed into the conduit 222 for discharging the gases, the plane of the flange being at the angle formed by the conduit 222 for gas evacuation and the horizontal duct 221.

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It should be noted that the striker 24 can take an intermediate position located between the initial position (FIG. 4) and the open position of the cylinder 21 (FIGS. 6 and 7).

Other aspects and variants

In the embodiment described above, the striker 24 has a beveled tip 241.

A striker having a pointed or pyramid-shaped end can be used. However, although a person skilled in the art would logically consider these forms for piercing a cover, the inventors have found that such forms do not allow optimal opening of the cover of the cylinder.

However, it has been observed by the inventors that an ogive shape allows an optimal opening of the cover 211 of the cylinder 21 and a better circulation of the gas around the tip of the ogive. A striker 24 'having a front end 241' in the form of a warhead is illustrated in FIG. 10. The angle a (alpha) of the two arcs of circle forming the warhead end can be more or less significant than that illustrated in Figure 10.

Note that the striker 24 is mounted tight in the rear part (that is to say on the side of the ignition means) to ensure that it is maintained throughout the life of the car seat. The rest of the striker body 24 is mounted with play to facilitate its movement when the load is triggered in particular.

3. gas distributor

The gas delivered by the cartridge 21 being at very high pressure (carbon dioxide at 60 bars, for example), it cannot by being directed directly, by simple pipes, towards the airbags.

A gas distributor 30 is therefore provided, as illustrated in FIGS. 11 to 21, which performs a triple function:

bringing the gas to an optimum pressure, speed and flow rate for inflating the cushions;

ensure gas expansion, and therefore avoid the formation of carbon dioxide snow;

π ensure symmetrical distribution of the gas in the two airbags, in the embodiment where two cushions are provided.

The regulator 30 thus comprises an expansion chamber 301, the volume of which is adapted to bring the gas to a pressure, a speed and a flow predefined at two outputs 302, 303, connected to the inputs of the cushions 141 and 142 respectively. In particular, at these outputs, the gas is brought down substantially to 1 bar. These specific values are essential constraints to be observed, to ensure effective inflation of the cushions.

The expansion chamber 301 comprises, at least in its upper part, a deflector, or switch, 304 ensuring a homogeneous distribution of the gas flow between the two cushions. It is substantially aligned (arrow 305) with the gas inlet 306 placed in the lower part of the chamber.

This gas inlet 306 is connected to the discharge opening 222 of the gas delivered by the canister, or tank. Note that, in the embodiment illustrated in FIGS. 11 to 21, this discharge opening 222 is not perpendicular to the gas cylinder 21, but that it forms an angle of less than 90 ° with the latter. . Consequently, the shape of the chamber 301 is asymmetrical, and defined so as to distribute the expanded gas homogeneously between the two outlets 302 and 303.

In this embodiment, the lower part 307 of the dispenser 30 carries the means necessary to receive (3071) the canister and integrate (3072) the opening elements of this canister.

The material used must of course be particularly resistant to resist the shock wave due to the explosion of the charge and the release of the gas. It may for example be polyamide reinforced with glass fiber (for example at 30%).

Such a dispenser is intended to be installed in particular in the back of a car seat. It must therefore be integrated in a reduced space, without harming the structural characteristics of the seat. The approach of the invention makes it possible to obtain reduced dimensions, as detailed in FIGS. 16 to 19. In particular, in the lower part (FIG. 18) the thickness is less than 2 centimeters.

Claims (15)

1. Gas distributor for inflatable cushion (s) of a childcare device, characterized in that it comprises a pressurized gas inlet, capable of being placed in communication with a tank containing a pressurized gas, an expansion chamber reducing the pressure of said gas, and at least one gas outlet, capable of being placed in communication with an airbag. 2. Gas distributor according to claim 1, characterized in that it comprises two gas outlets, each supplying an airbag. 3. Gas distributor according to claim 2, characterized in that said gas inlet, said expansion chamber and / or said gas outlets are configured so as to distribute substantially the same amount of gas between the two airbags. 4. Gas distributor according to claim 3, characterized in that said expansion chamber carries at least one switching element capable of directing the gas substantially homogeneously towards the two outlets. 5. Gas distributor according to claim 4, characterized in that it comprises at least one deflector placed in the upper part and oriented substantially along the axis of said gas inlet. 6. Gas distributor according to any one of claims 1 to 5, characterized in that said gas inlet forms an angle less than 90 ° with said tank. 7. Gas distributor according to any one of claims 1 to 6, characterized in that it comprises means for securing said tank. 8. Gas distributor according to any one of claims 1 to 7, characterized in that it carries at least one pyrotechnic charge and means for igniting / activating said charge triggered during a predetermined condition, for ensure the opening of said tank. 9. Gas distributor according to any one of claims 1 to 8, characterized in that said expansion chamber ensures a passage of a pressure of substantially 30 bars at the level of said gas inlet to substantially 1 bar at the level of the gas outlet (s). 10. Gas distributor according to any one of claims 1 to 9, characterized in that said expansion chamber is made of polyamide reinforced with glass fiber. 11. Gas distributor according to any one of claims 1 to 10, characterized in that it is dimensioned and configured to be housed in a car seat backrest. 12. Child care device capable of receiving a child comprising at least one gas distributor according to one of claims 1 to 11. 13. Child care device according to claim 12, characterized in that it comprises a harness (12) having two straps (121, 122) intended to extend from the shoulders along the torso of a child, each of suspenders (121, 122) carrying an inflatable safety element (141, 142), capable of inflating in the event of an impact greater than a predetermined threshold. 14. Child care device according to claim 12 or 13, characterized in that it comprises a seat, said gas generator (2) being housed in the backrest (114), in at least one of the lateral flanks, and / or in the base of said seat. 15. Child care device according to one of claims 12 to 14, characterized in that it is a car seat, a stroller, a carrycot, or a bicycle seat.