JPH07144991A - High-temperature chemical ignition device in gas generator - Google Patents

Abstract

PURPOSE: To obtain a device which acts a sufficient pressure elevation in a gas generator and, consequently assures a permissible ignition over the entire part starting from known constitution.

CONSTITUTION: The high-temp. chemical ignition device having an org. metallic detonator and a hermetically sealed igniter having an electrical igniting means at least partially embedded into the propagation charge of the gas generator is provided with at least two detonators 5, 6 in an ignition case and at this time the second detonator 6 has decreased blasting power with respect to the first detonator 5 and the first detonator 5 encloses the igniter 7 and is the org. metal explosive. The second detonator 6 is an inorg. mixture. Both detonators 5, 6 are compressed to a laminar form and are compactly hermetically sealed.

COPYRIGHT: (C)1995,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an organometallic detonator and at least partially embedded in the propellant charge of a gas generator,
A sealed igniter having electrical ignition means,
The present invention relates to a high temperature chemical ignition device in a gas generator.

[0002]

BACKGROUND OF THE INVENTION Gas generators (airbags) for collision protection systems according to the preamble of claim 1 are known (eg West German patent specification 4102275).
issue). Boron from U.S. Pat. No. 5109772 / potassium nitrate (BKN0 ₃₎ is a fast ignition material and diffusion of the ignition of the material generating gas for high temperature chemical fuels,
Used as a quick igniter for inflating airbags. In order to obtain the desired effect, boron / potassium nitrate (BKN0
₃ ) is distributed over a wide area along the entire gas generator and is coated with a disk for this purpose, which likewise forms a layered chamber. This is obtained by immersion of the correspondingly mechanical portion of the aqueous boron / potassium nitrate (BKN0 ₃₎ in with a subsequent drying step. Gas generators of this kind are ignited by conventional thermo-electric igniters. This configuration is relatively costly and bulky and only works with an improved flame distribution of the already ignited gas generator.

In the technological development of airbags and pyrotechnic bandages, the known systems negatively influence the gas diffusion and adversely affect the desired sufficient inflation of the airbag or mechanically. It has been shown to cause an ignition pressure pulse that causes overstrain. The same is true for pyrotechnic ballistic bands where the pressure piston is biased too quickly.

[0004]

The invention, starting from the known construction, creates a device which exerts a sufficient pressure rise in the gas generator and thus guarantees an overall acceptable ignition. This is an issue.

[0005]

According to the invention, the object of the invention is to provide the igniter with at least two initiators, the second initiator being in relation to the first initiator. With reduced blasting power, the first detonator is an organometallic explosive surrounding the igniter, the second detonator is an inorganic mixture, and both detonators are layered compressed and compacted and sealed. Will be solved.

The solution according to the invention consists in adapting the igniter to a system-technically suitable detonation rate in the range of priming agents, as a second and possibly other priming agent layer itself. It is based on the fact that a worthless explosive can be used.

The use of two detonators in the igniter actually results in an acceptable ignition of the first detonator-layer and subsequently a reduced ignition in the second less detonable explosive-layer. Acts on diffusion of ignition at speed.

The common compression of both explosive layers produces the desired detonating action, even with explosives of surprisingly low explosive force. The use of the propellant charge, or at least the composition of the propellant charge, has been demonstrated, according to claim 2, as provided in a gas generator.

The second initiator, according to claim 3, is a boron / potassium nitrate (BKN) in compressed form.
0 ₃ ) was specifically demonstrated. Corresponding to claim 4, lead trinitroresorcinol, in combination with other explosives having a low blasting power, produces the necessary ignition safety.

It makes sense to choose a ratio of both explosives according to claim 5 because on the one hand the required pressure configuration is ensured and on the other hand the spire pressure is avoided. .

In addition, the boron / potassium nitrate (BKN0 ₃ ) ratio according to claim 6 can be adapted and optimized for the desired pressure conditions. Suitable particle sizes of the claims paragraph 7 by boron / potassium nitrate (BKN0 ₃₎ produces a functional safety is improved.

[0012] Selection of the particle size or crystalline boron / potassium nitrate (BKN0 ₃₎ mixture helps to improve the quality of similarly ignition process. According to claim 9, the explosive layer in the synthetic resin is preferably compressed and sealed, which is significant for reaction chemistry and corrosion engineering reasons.

The use of a cauterizing wire according to claim 10 is highly regarded in connection with the use of two initiator layers and the cauterizing wire is very economical to manufacture. Next, embodiments of the object of the present invention will be described with reference to the drawings.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a bowl-shaped gas generator designated by 100. The gas generator consists of a combustion chamber housing 101 with a chamber not shown in detail, a baffle plate and a filter element and in the center boron / potassium nitrate (BKN0).
Cylindrical central tube 10 with a propellant charge 103 consisting of ₃ )
Have two. The holes 104 in the form of holes ensure, after ignition, the passage of gases into the combustion chamber 106, which is filled with so-called pellets known as pyrotechnic charge, known per se. The ignition signal is transmitted via the electrical plug 108 and the two-pole ignition cable 109.
Are connected via a sensor, generated and supplied to the device.

The igniter 1 is centered axially symmetrically and held by the support flange 105 and the chamber flange 105b. The safety axle 105a prevents axial movement and the safety bush 110 additionally serves for mooring. The details of the incorporation of the igniter 1 into the propellant charge 103 are apparent from FIG. In addition, there is a plug-in mooring section 9 here.

The housing 2, the metal cap formed by the flange, has a notch 3 on the end face, which has a target breaking point and ensures the intended gas penetration into the propellant charge 103. The case 2 thus formed has a charge cap 4 made of synthetic resin, and the first detonator 5 and the second detonator 6 are compressed under pressure in the charge cuff. There is. In the first initiator 5 there is a burning wire 7, which forms a resistive bridge between the contact pins 8 and acts as an electrical ignition means.

The contact pin 8 is cast on its end face in a flat glass insulator 10. As can be seen from the illustration essentially limited to the invention according to FIG.
03 and the second initiator consists of a mixture of the same material, namely a boron / potassium nitrate (BKN0 _3). The first detonator layer 5 is composed of lead trinitroresorcinol also called tricine.

As is apparent from FIG. 3, in a test capsule (test bomb) having a volume of 3 cm ³ , a test capsule within about 1 ms has a capacity of about 90.
A pressure of bar is constructed, which is reduced only very slowly during the 10 ms interval. At an ambient temperature of 85 ° C., a maximum pressure of 97 bar is constructed between 1 ms and 2 ms, which pressure drops to 80 bar after 0.5 ms and after 10 ms to 60 bar. At 20 ° C. the maximum pressure is 90 bar, dropping to 80 bar after 0.5 ms and to approximately 70 bar after 7 ms.

The pressure range which is unacceptable for system technical reasons is shaded in the diagram according to FIG. The object of the present invention satisfies the condition even at a very low temperature. At −35 ° C., a pressure of approximately 70 bar is built up in a time of less than 2.0 ms and this pressure remains unchanged for a time of more than 10 ms.

The pressure profile in the gas generator with the igniter according to the invention is essentially essential for the acceptable functioning of the collision protection system. It was demonstrated that an explosive layer of 75 mg of boron / potassium nitrate (BKN0 ₃ ) as a second detonator as well as a compressed first detonator of 30 mg of tricine was optimal. Potassium nitrate (KN0 ₃ )
The ratio of boron (B) with respect is boron 40% by weight potassium nitrate (KN0 ₃₎ 60 wt%.

The particle size of boron was in the range of 50 microns. The detonation gas diffusion in the igniter by means of quantitative changes within the limits stated in the claims allows the detonation gas diffusion to be adapted to the physical properties of the airbag or its mechanical distortability. Controlled by. Similarly, the pressure profile in the ammunition zone, along with other system parameters of the gas generator, is matched to the dynamic conditions of the pressure piston and the diffusion mechanism.

In order to obtain the detonation ignition effect of both explosive layers, compression in case 2 is necessary. 10,000 N / cm ²
It has been proved that the compressive force up to is reasonable. The surprising method does not cause accidents even with high obstacle pressure.

There can be more than one explosive layer if the igniter is to be adapted to a system-constrained, sufficient pressure regime. Similarly, conventional detonators can also be used with the desired pressure profile, with the igniter generally starting with a high explosive charge and converting to a lower explosive charge.

[0024]

According to the invention, it is possible to obtain a device in which a sufficient pressure rise is exerted in the gas generator and thus ensures an overall acceptable ignition.

[Brief description of drawings]

FIG. 1 shows a gas generator equipped with an ignition device according to the invention.

2 is an enlarged cross-sectional view of the gas generator of FIG. 1 showing details of the structure of the igniter.

FIG. 3 shows characteristic pressure curves obtained with an igniter according to the invention at different temperatures.

[Explanation of symbols]

 5 First detonator 6 Second detonator 7 Ignition means

Claims (10)

[Claims] 1. A high temperature chemical igniter in a gas generator comprising an organometallic detonator and a sealed igniter at least partially embedded in the propellant charge of the gas generator and having electrical ignition means. At least two detonators (5, 6) are provided in the ignition case, the second detonator (6) having a reduced detonation force relative to the first detonator (5). And the first detonator (5) is an organometallic explosive surrounding the ignition means (7), the second detonator (6) is an inorganic mixture and both detonators (5, 6) are layered. The high temperature chemical ignition device, wherein the high temperature chemical ignition device is compressed and hermetically sealed. 2. High-temperature chemical ignition according to claim 1, wherein the second initiator (6) consists of at least two compositions and the same composition is present in the propellant charge (103) in the gas generator (100). apparatus. 3. The high temperature chemical igniter according to claim 2, wherein the reaction composition of the second initiator (6) is boron and potassium nitrate. 4. The high temperature chemical ignition device according to claim 1, wherein the first initiator (5) is lead trinitroresorcinol. 5. The high temperature chemical ignition device according to claim 1, wherein the weight ratio of the first detonator (5) to the second detonator (6) is 1: 2 to 1: 5. 6. The ratio of boron to potassium nitrate is boron 1
0-70 wt% versus potassium nitrate (KN0 ₃₎ 30~90
The high temperature chemical igniter of claim 3, which is in weight percent. 7. Trinitroresorcin lead 80-120
The high temperature chemical igniter of claim 4, having a particle size of micron. 8. The high temperature chemical igniter of claim 6, wherein the boron / potassium nitrate has an average particle size of 40 to 70 microns. 9. A high-temperature chemical ignition device according to claim 1, wherein both initiators (5, 6) are sealed in a synthetic resin cap (4) in a compressed form. . 10. The ignition means (7) is a burning wire,
The high temperature chemical ignition device according to claim 1.