WO2021227578A1

WO2021227578A1 - Gas generator

Info

Publication number: WO2021227578A1
Application number: PCT/CN2021/075535
Authority: WO
Inventors: 罗运强; 杜涛; 张俊; 任响宁; 沈晓琛
Original assignee: 湖北航鹏化学动力科技有限责任公司
Priority date: 2020-05-15
Filing date: 2021-02-05
Publication date: 2021-11-18
Also published as: CN111548242B; CN111548242A

Abstract

The present invention relates to a gas generator. By changing the structure and layout of a filter and the formulation and type of a gas-generating drug to achieve staged combustion, the filtration efficiency of the filter is improved, the initial output voltage gradient of the gas generator is reduced, and a small size, a light weight and a reliable workability of the gas generator are achieved. In addition, by designing the gas generating agent composition formulation, using a zirconate, a silicate or a mixture of a zirconate and a silicate as a slag-forming agent and combining same with the rest of the components, the rest of the tablets, after burning in the filter, can coagulate and agglomerate, the pre-combustion state is well maintained, the melting and splashing of the tablets after burning to burn an air bag are completely avoided, and the slagging during the combustion of the gas generating agent composition is increased by at least 50%.

Description

The gas generator

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 202010413128.6, and the invention title is "gas generator" on May 15, 2020, the entire content of which is incorporated into this application by reference.

Technical field

The invention relates to a gas generator and belongs to the technical field of gas generators for automobile safety airbags.

Background technique

The car airbag gas generating agent is used as a gas-producing agent to be loaded into the gas generator, which is triggered when needed to produce a large amount of gas. The airbag consists of a gas generator and an air bag. Generally, when the collision exceeds the preset intensity, the gas generator is activated and triggered to start burning the internal gas generating agent to generate gas, inflate the air bag, and form a cushion air cushion between the interior and the human body to protect the human body from injury.

The early stage of the gas generating agent is mainly the sodium azide type gas generating agent formula. This formula has many advantages such as stable combustion, low combustion temperature, easy ignition, low internal pressure, high gas production rate, and less residue. However, due to environmental protection and human health and safety issues, it is now rarely used in automobile airbags.

At present, the mainstream gas generating agents worldwide are guanidine nitrate and basic copper nitrate gas generating agents, with guanidine nitrate as the main fuel and basic copper nitrate as the main oxidant. The combustion temperature of this type of gas generating agent is generally high. After combustion, basic copper nitrate mainly produces molten copper metal, which usually requires a multilayer metal filter to filter and cool it, leaving it inside the generator. On the one hand, the increase in the weight of the metal filter will increase the cost and the weight of the generator; on the other hand, even if the multi-layer filter is used, all the residues cannot be filtered. A small part of the residue can burn the air bag through the filter, and more serious will cause burns. human body.

Therefore, the solution is generally: 1. Reduce the amount of basic copper nitrate used, thereby reducing the molten copper residue formed after the combustion of the gas generating agent composition; 2. Add a form-retaining agent to the composition formula. The form-retaining agent is generally a high-melting substance, which functions to increase the viscosity of the molten residue and maintain its shape as a tablet matrix.

Strontium titanate is a metal compound with a high melting point. It has also been used in the field of airbag gas generating agents. For example, patent CN105801326A is a gas generating agent formulation mainly containing guanidine nitrate, basic copper nitrate, and titanate. However, this patent uses titanate as a form-retaining agent, which does not have a significant effect on the form-maintaining effect, and cannot play a good role in maintaining the combustion form, especially for basic copper nitrate content greater than 40%, and guanidine nitrate content greater than 40% The gas generating agent can not play a good role in maintaining the combustion form, and the gas generating agent formula is not easy to be ignited.

For example, patent CN100376515C discloses a gas generating composition, including guanidine nitrate, basic copper nitrate, auxiliary oxidizing agent sodium nitrate, copper oxide and iron oxide, and ignition modifiers (aluminum trioxide, copper chloride, copper chromate, Potassium chromate), the use of ignition modifier makes the gas generating composition easier to ignite, and the ignition delay period is short, but aluminum oxide is generally used for residue agglomeration and has little effect on ignition improvement; copper chloride is a weak oxidant for ignition The improvement effect is not great; copper chromate and potassium chromate are strong copper-containing oxidants, which can play a certain ignition improvement effect, but both will increase the residue content. Copper chromate increases the insoluble residue content, and potassium chromate can increase the content of residues. The content of dissolved residue and the burning of substances containing alkali metal potassium will form soluble aerosol particles, which is not good for residue agglomeration.

For another example, the patent US5827996A discloses a gas generating agent for airbags, including the use of azoles or metal salts, oxidizers, combustion catalysts, combustion control agents and slagging agents for fuel, azoles and metal salts for fuels, and solidification of the slagging agent. Additive to the combustion residue of the gas generating agent, which is beneficial to the filter in the airbag to remove the residue. However, the patent is applicable to the formulation of azoles as fuel. This type of formulation has a higher combustion temperature than the basic copper nitrate type of guanidine nitrate. Many, even if the slag forming agent is added, the form of the tablet cannot be maintained well.

In addition, the patent CN101952227B discloses a method for preparing a gas generating agent, adding guanidine nitrate, basic copper nitrate, auxiliary oxidants (such as potassium nitrate, strontium nitrate and sodium nitrate), burning rate regulator (potassium perchlorate), slag promoting Agent (silica, zinc oxide, ammonium oxide, aluminum oxide), tablet release aid and shape retention synergistic aid B (graphite, molybdenum disulfide, tungsten disulfide, boron nitride), the granulation used in this patent The method is spray granulation. Compared with wet granulation, spray granulation has higher energy consumption. In addition, the slag accelerator used in this patent mainly comes from metal oxides, such as silica, alumina, zinc oxide, and cerium oxide. As a slag accelerator, metal oxide can play a certain role in promoting slag agglomeration, but it is not obvious for maintaining the shape of the tablet.

The previous application with application number CN107698415A discloses a gas generating agent consisting of guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, strontium titanate, and talc. Although the application of strontium titanate has a slag-forming effect , But in the formula with BCN/GN as the system, its slag-forming effect is not significant. In practical applications, it is found that its slag-forming effect cannot meet the needs. And a large number of tests have shown that the density of the tablet is poor after burning. It is fragile and will easily cause it to fly out of the generator filter and fall into the air bag, which may ablate the air bag and bring potential hazards to the human body.

In addition, the gas generator is a key component in the field of automotive passive safety. The traditional gas generator structure generally uses a cup-shaped lower shell with a built-in filter. The filter is molded from low-carbon steel wire. The lower shell is embedded with an igniter seat, and the igniter seat is embedded with an igniter and an ignition shell. The ignition shell, the igniter seat, the upper shell, the lower shell, and the filter constitute a gas generating chemical chamber. The gas generating chemical chamber generally contains a cylindrical gas generating chemical, as shown in Figure 11.

This kind of pyrotechnic gas generator with a cup-shaped lower shell, due to the gas flow characteristic of the gas flow toward the exhaust port, the filter screen of the traditional structure gas generator is approximately equal to the height of the generator, and the traditional structure generator exhaust hole design On the upper shell, due to the above-mentioned characteristics of gas fluidity, only the part of the filter that is highly overlapped with the upper shell plays a role in filtering the residues generated by the combustion of gas generating chemicals, so the filter loses part of the power, which is not conducive to the small size of the gas generator Lightweight.

Because the utilization rate of the filter is not high, if the gas purity is improved, the weight of the filter needs to be increased, resulting in the large size and weight of the entire gas generator and heavy weight. In addition, the gas-generating drug chamber of the existing pyrotechnic gas generator is filled with cylindrical gas-generating drug. When the ignition powder acts on the gas-generating drug, all the gas-generating drugs are ignited at one time. The initial slope output of the pyrotechnic gas generator is too high, and the initial slope is too high, which will have a great impact on the pyrotechnic gas generator and easily cause the gas generator to fail. In order to realize the low initial slope of the gas generator and avoid greater impact and failure on the gas generator, a new gas-producing chemical structure is designed to realize the staged combustion characteristics.

Summary of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a gas generator that realizes staged combustion by changing the structure and layout of the filter and the formulation of gas generating drugs, thereby improving the filtering efficiency of the filter and reducing gas generation. The initial output slope of the gas generator realizes the small size, light weight and reliable operation of the gas generator; in addition, through the design of the gas generating agent composition formula, zirconate, silicate or a mixture of zirconate and silicate is used As a slag-forming agent, it can be combined with other components to make the tablets condense and agglomerate in the filter after burning. It keeps the pre-combustion state very well, completely avoids the melting of the tablets after burning and burns the air bag, so that the gas generating agent composition The slagging during combustion is improved by at least 50%.

The above-mentioned objects of the present invention are mainly achieved through the following technical solutions:

A gas generator includes an upper shell, a filter, a lower shell, an igniter seat, an igniter, an ignition shell, a gas generating powder, and an ignition powder. The igniter seat is embedded in the lower shell and is characterized in that : The lower shell has a double-cup structure and is composed of a first cup and a second cup with different inner diameters. The inner diameter of the first cup is larger than the inner diameter of the second cup; the upper shell is connected to the The opening of the cup body; the bottom surface of the first cup body and the bottom inner surface of the upper shell press the upper and lower end surfaces of the filter; the bottom inner surface of the upper shell, the second cup body, the outer surface of the igniter seat, and the outer surface of the ignition shell The surface and the inner surface of the filter constitute a gas generating chamber;

The gas generating agent composition adopted by the gas generator includes the following components in mass percentage content:

The slag-forming agent is at least one zirconate, or at least one silicate, or a mixture of at least one zirconate and at least one silicate.

In the above gas generator, the shape of the gas generating drug built in the gas generating drug chamber is a mesoporous columnar shape, and the ratio of the major axis to the minor axis radius of the columnar cross section is greater than one.

In the above gas generator, the inner diameter of the middle hole is greater than or equal to 1 mm and less than or equal to 3 mm, and the ratio of the major axis to the minor axis radius is greater than or equal to 1.5 and less than or equal to 4.

In the above gas generator, the filter is made by rolling more than one layer of metal material plates, and each layer of metal material plates has a thickness of 0.1mm to 1.0mm; each layer of metal material plates of the filter is evenly provided with vent holes , The diameter of the vent hole is not more than 0.5mm.

In the above gas generator, the ratio of the height of the filter to the height of the first cup is greater than 10.

In the above gas generator, the upper shell is an inverted cup body relative to the lower shell, more than one vent hole is evenly arranged on the side wall of the cup body, and the inner surface of the side wall of the cup body is pasted with a sealing foil, The sealing foil covers the vent hole.

In the above-mentioned gas generator, the inner diameter of the upper shell and the outer diameter of the opening of the first cup body are integrated by interference fit and welded.

In the above gas generator, the thickness of the upper shell and the lower shell is 1.0mm～2.0mm, and the material uses cold-rolled steel plate with a tensile strength greater than 300MPa; the ignition shell adopts a long cylindrical structure and a long cylindrical A fire hole is evenly arranged on the side wall of the shaped structure; the thickness of the ignition shell is 0.5 mm to 1.5 mm, and the material is cold-rolled steel plate with a tensile strength greater than 300 MPa.

In the above-mentioned gas generator, the igniter seat is inserted into the lower shell, and the combined part of the two adopts interference fit and is connected by welding to form a whole; the ignition shell connects the two through the metal deformation of the igniter seat Become one.

In the above gas generator, the zirconate is one or a combination of strontium zirconate, barium zirconate, or calcium zirconate.

In the above gas generator, the silicate is one or a combination of zirconium silicate or calcium silicate.

In the above gas generator, the slag-forming agent is a mixture of at least one zirconate and at least one silicate, and the mass ratio of zirconate to silicate is 1:0.5-3; preferably 1: 0.8～2.

In the above gas generator, the slag-forming agent is a mixture of strontium zirconate, zirconium silicate and calcium silicate, and the mass ratio of the three is 1:0.2-1.5:0.3-1.5, preferably 1:0.3-1: 0.5～1.

In the above gas generator, the slag-forming agent is a mixture of strontium zirconate and barium zirconate, and the mass ratio of the two is 1:0.5-3, preferably 1:0.8-2.

In the above gas generator, the lubricant is one or a combination of talc, graphite, calcium stearate, magnesium stearate, molybdenum disulfide or boron nitride.

In the above gas generator, the particle size D90 of the ammonium perchlorate is not greater than 20μm; the particle size D90 of the slag-forming agent is not greater than 5μm; the particle size D90 of the basic copper nitrate and the lubricant is not greater than 5μm .

In the above gas generator, the sum of the water content of each component of the gas generating agent composition is not more than 1% of the total mass of each component.

In the above gas generator, the gas generating agent composition is formed into a circular or elliptical sheet structure, a circular or elliptical cylindrical structure, a special-shaped sheet or cylindrical structure, a circular or elliptical single-hole structure, Round or oval porous structure, special-shaped single-hole or porous structure.

In the above gas generator, the diameter of the circular sheet structure is 3-15mm and the height is 2-5mm; the diameter of the circular columnar structure is 3-15mm and the height is 5-15mm; the circular single-hole structure The inner diameter is 0.5-2.5mm, the outer diameter is 3-15mm, and the height is 3-15mm; the inner diameter of the oval single-hole structure is 0.5-2.5mm, the long diameter is 3-20mm, the short diameter is 2-12mm, and the height is 3-15mm.

In the above gas generator, the gas generating agent composition is prepared by wet granulation, spray granulation or dry granulation; the specific preparation method of the wet granulation includes the following steps:

(1) The first material is obtained by mixing guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate and a slag-forming agent;

(2) Add water to the first material for wet mixing to obtain the second material, wherein the amount of water added is 8% to 15% of the total mass of the first material;

(3) Pass the second material through a 10-40 mesh screen to obtain the third material;

(4) Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and pass the 10-40 mesh screen again to obtain the fourth material;

(5) Add lubricant to the fourth material to form the material.

In the above gas generator, in the step (1), guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate and slag-forming agent are mixed in a mixing device to obtain the first material, and the mixing time is ≥5min; The time of wet mixing in the step (2) is 20min-60min; the wet mixing equipment is a kneader or a mixer.

In the above gas generator, the gas generating agent composition is prepared by wet granulation, and the specific preparation method includes the following steps:

(1) Mix guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, slag-forming agent and lubricant to obtain the first material;

(5) The fourth material is formed into material.

In the above gas generator, in the step (1), guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, slagging agent and lubricant are mixed in a mixing device to obtain the first material, and the mixing time ≥5min; the wet mixing time in the step (2) is 20min-60min; the wet mixing equipment is a kneader or mixer.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention adopts a double cup design for the lower shell of the gas generator, with a first cup and a second cup. The height ratio of the filter to the first cup can be greater than 10, so the filter The filtration efficiency of the pyrotechnic generator is greater than 90%, which avoids that the ratio of the height of the filter of the pyrotechnic generator to the lower shell is generally not greater than 3, only the part of the filter that is higher than the lower shell and overlaps the upper shell In order to filter the residue generated by the combustion of gas-producing drugs, the filtration efficiency of the filter is generally not more than 60%.

(2). The present invention adopts a gas-generating drug with a mesoporous cylindrical shape and a long-axis-short-axis radius ratio greater than 1, which realizes the staged combustion of the drug type, reduces the initial output slope of the gas generator, and avoids gas generation. Impact and failure of the device.

(3) The present invention realizes staged combustion by changing the structure and layout of the filter and the formula of the gas generating drug, thereby improving the filtering efficiency of the filter, reducing the initial output slope of the gas generator, and realizing the small size of the gas generator. Light weight and reliable operation, especially significantly reducing the weight of the filter in the gas generator;

(4) The present invention uses zirconate, silicate or a mixture of zirconate and silicate as the slag-forming agent of the gas generator in the gas generator for the first time. The combination of ammonium perchlorate and mold release agent enables the tablet to maintain its pre-combustion form after combustion, completely avoids the tablet's melting splash and burns the air bag after combustion, and significantly reduces the molten copper formed after the combustion and decomposition of basic copper nitrate. The residue significantly improves the low-temperature ignition performance of the composition and at the same time increases the combustion speed, so that the slagging during the combustion of the gas generating agent composition is increased by at least 50%.

(5) In the gas generating agent formula of the present invention using basic copper nitrate and guanidine nitrate as the system, zirconate, silicate or a mixture of zirconate and silicate is added for the first time as the slag-forming agent of the gas generating agent , The molten copper metal can be condensed and agglomerated into lumps. The melting point is about 2500K. The slag-forming agent is not easy to burn. When the gas generating agent composition is combusted, it can collect all the solid combustion product agglomerates together to make the gas The generator maintains its original shape after combustion; a large number of experiments show that the zirconate, silicate or the mixture of the two used in the present invention can form good condensation on the metallic copper melt formed after the decomposition of basic copper nitrate It can further reduce the molten copper residue, increase the viscosity of the molten residue and maintain its shape as a tablet skeleton, resulting in a significant effect of coagulation and slagging.

(6) The present invention uses zirconate, silicate or a mixture of zirconate and silicate as the slag-forming agent of the gas generating agent for the first time, so that the gas is generated while the burning rate of the gas generating agent remains unchanged. The slag formation during the combustion of the agent composition is increased by at least 50%. After the generator has done the TANKWASH residue test, the total content of insolubles and water-solubles is far less than 1g (USCAR industry requirements), and the total content is about 0.4g about.

(7) The present invention uses a certain amount of ammonium perchlorate and strontium nitrate as auxiliary oxidizers, which are used in conjunction with other components, and zirconate, silicate or a mixture of zirconate and silicate is added as gas generation The slag-forming agent can improve the low-temperature ignition performance of the composition and increase the combustion speed at the same time, and meet the requirements of the USCAR standard.

(8) The present invention optimizes the design of the process and process conditions of wet granulation, making the preparation process simple and easy to realize. At the same time, the release agent in the preparation method of the present invention can be mixed with the rest of the components before being wet. Method, you can also add lubricant at the end, the preparation method is more flexible.

Description of the drawings

Figure 1 is a diagram of the residue morphology of the gas generant composition tablet after combustion in Comparative Example 1 of the present invention;

2 is a morphological diagram of the residue after combustion of the gas generant composition tablet in Example 1 of the present invention;

3 is a diagram of the residue morphology of the gas generant composition tablet after combustion in Comparative Example 2 of the present invention;

4 is a morphological diagram of the residue after combustion of the gas generating agent composition tablet in Example 2 of the present invention;

5 is a diagram of the residue morphology of the gas generant composition tablet after combustion in Comparative Example 3 of the present invention;

Fig. 6 is a morphological diagram of the residue after combustion of the gas generant composition tablet in Example 3 of the present invention;

Fig. 7 is a morphological diagram of the residue after combustion of the gas generant composition tablet in Example 4 of the present invention;

Fig. 8 is a morphological diagram of the residue after combustion of the gas generant composition tablet in Example 5 of the present invention;

Fig. 9 is a morphological diagram of the residue after combustion of the gas generant composition tablet in Example 6 of the present invention.

Figure 10 is a schematic diagram of the structure of the gas generator of the present invention;

Figure 11 shows the shape of the original gas-producing pyrotechnic gas generator;

Figure 12 is the shape of the gas generating medicine of the gas generator of the present invention;

Figure 13 is a schematic diagram of the combustion process of the gas generating agent of the present invention;

14 is a schematic diagram of the combustion surface curve of the gas-producing medicine type of the present invention and the original gas-producing medicine type;

15 is a graph of the output slope of the pyrotechnic gas generator in the embodiment of the present invention and the comparative example;

Fig. 16 is a structural schematic diagram 1 of a modification scheme of the present invention;

Fig. 17 is a schematic structural diagram 2 of a modification of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments:

The gas generating agent composition of the present invention includes guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, slag-forming agent and lubricant, wherein the slag-forming agent is at least one zirconate or at least one silicic acid Salt, or a mixture of at least one zirconate and at least one silicate, the lubricant is selected from at least one of talc, graphite, calcium stearate, magnesium stearate, molybdenum disulfide or boron nitride ；

The mass percentage content of each component is as follows:

The above-mentioned zirconate is one or a combination of strontium zirconate, barium zirconate or calcium zirconate.

The above-mentioned silicate is one or a combination of zirconium silicate or calcium silicate.

The slag-forming agent is a mixture of at least one zirconate and at least one silicate, and the mass ratio of zirconate to silicate is 1:0.5-3.

In an optional embodiment of the present invention, the slag-forming agent is a mixture of strontium zirconate, zirconium silicate and calcium silicate, and the mass ratio of the three is 1:0.5-3:0.5-3.

In an optional embodiment of the present invention, the slag-forming agent is a mixture of strontium zirconate and barium zirconate, and the mass ratio of the two is 1:0.5-3.

The particle size D90 of the ammonium perchlorate is not more than 20 μm; the particle size D90 of the slag-forming agent is not more than 5 μm; the particle size D90 of the basic copper nitrate and the lubricant/release agent is not more than 5 μm.

The sum of the water content of each component of the above-mentioned gas generating agent composition is not more than 1% of the total mass of each component.

In an optional embodiment of the present invention, the gas generating agent composition is formed into a circular or elliptical sheet structure, a circular or elliptical columnar structure, a special-shaped sheet or columnar structure, a circular or elliptical single-hole structure, Round or oval porous structure, special-shaped single-hole or porous structure. The diameter of the circular sheet structure is 3-15mm and the height is 2-5mm; the diameter of the circular columnar structure is 3-15mm and the height is 5-15mm; the inner diameter of the circular single-hole structure is 0.5-2.5mm, and the outer diameter The elliptical single-hole structure has an inner diameter of 0.5 to 2.5 mm, a long diameter of 3 to 20 mm, a short diameter of 2 to 12 mm, and a height of 3 to 15 mm.

The preparation method of the gas generating agent composition of the present invention can be prepared by wet granulation, spray granulation or dry granulation. Among them, spray granulation or dry granulation can adopt traditional granulation technology.

The specific preparation method of wet granulation includes the following steps:

(1) Mix guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate and slag forming agent to obtain the first material; mix in the mixing equipment, the mixing time is ≥5min; the mixing equipment can be V-type mixing Machine, three-dimensional multi-directional motion mixer, automatic lifting hopper mixer, vibration mill, ribbon mixer or acoustic resonance mixer.

(2) Add water to the first material for wet mixing to obtain the second material. The wet mixing time is 20min-60min; the amount of water added is 8%-15% of the total mass of the first material; distilled water is preferably added. The equipment for wet mixing is a kneader or a mixer, for example, a horizontal kneader, a vertical kneader, a ribbon mixer, or an acoustic resonance mixer can be selected.

(4) Dry the third material until the water content is less than 0.5% of the total mass of the third material, and pass the 10-40 mesh screen again to obtain the fourth material; the drying equipment can be an electric heating oven, oil Bath oven, steam oven, double cone oven, vibrating fluidized bed or belt vacuum dryer.

(5) Add lubricant to the fourth material to form the material. The molding equipment can be a hydraulic press, a rotary tablet press or a powder molding machine.

Another specific preparation method of wet granulation includes the following steps:

(1) Mix guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, slag-forming agent and lubricant to obtain the first material; mix in the mixing equipment, the mixing time is ≥5min; the mixing equipment can be Pneumatic mixing equipment, V-type mixer, three-dimensional multi-directional motion mixer, automatic lifting hopper mixer, vibration mill, ribbon mixer or acoustic resonance mixer.

(5) The fourth material is formed into material. The molding equipment can be a hydraulic press, a rotary tablet press or a powder molding machine.

In the gas generating agent formula of the present invention using basic copper nitrate and guanidine nitrate as the system, zirconate, silicate or a mixture of zirconate and silicate is added as a slag-forming agent of the gas generating agent for the first time, so that the molten Copper metal can condense and agglomerate into lumps. The melting point is about 2500K, which is much higher than the melting point of metallic copper. A large number of tests have shown that the slag-forming agent is not easy to burn. When the gas generating agent composition is burned, it can attach all solid combustion products. The polymer is collected together so that the gas generating agent maintains its original shape after combustion. The zirconate, silicate or the mixture of the two of the present invention can form a good coagulation effect on the metallic copper melt formed after the decomposition of basic copper nitrate, and further reduce the molten copper residue. It can increase the viscosity of the molten residue and maintain its shape as a tablet skeleton, resulting in a significant effect of coagulation and slagging.

The mixing equipment used in the following embodiments is a three-dimensional multi-motion mixer (or ultra-efficient mixer), the kneader is a horizontal kneader, the drying equipment is a vacuum oven, and the molding equipment is a rotary tablet press.

Comparative example 1

The gas generating agent composition contains the following components in mass percentage content:

Guanidine nitrate 40%

Basic copper nitrate 40%

Strontium nitrate 12.75%

Ammonium perchlorate 1%

Strontium titanate 5.5%

Talc 0.75%

After these components are weighed, they are compressed into a 5mm diameter and 1.9mm thick disc by wet granulation and a rotary tablet press. The specific preparation method is: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate After mixing with strontium titanate through a mixing device, the first material is obtained; the first material is added to 15% distilled water for wet kneading for 60 minutes to obtain the second material, and the second material is passed through a 40-mesh screen to obtain the third material; The three materials are dried until the moisture content is less than 0.5% of the total mass of the third material, and the fourth material is obtained through a 40-mesh screen again; talc powder is added to the fourth material, and the material is formed by a rotary tablet press.

Put the prepared discs into the test gas generator, and conduct ignition and combustion tests. After the test, the generator was dissected and the shape of the tablet after burning was observed.

Figure 1 shows the morphology of the residue after combustion of the gas generant composition tablet in Comparative Example 1 of the present invention; the following Table 1 shows the soluble residue and insoluble residue of the gas generant composition tablet in the present invention after combustion. Statistics of weight and low-temperature ignition delay time; from Figure 1 and Table 1, it can be seen that the tablet is in the form of a sheet, which is close to the inner wall of the filter, and its density is poor. Falling into the air bag may ablate the air bag and bring potential danger to the human body. Its low temperature ignition time meets the requirement of less than 7ms.

Table 1

Example 1

Guanidine nitrate 40%

Basic copper nitrate 42.75%

Strontium nitrate 8%

Ammonium perchlorate 3%

Barium zirconate 5.5%

Talc 0.75%

After these components are weighed, they are compressed into a 5mm diameter and 1.9mm thick disc by wet granulation and a rotary tablet press. The specific preparation method is: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate The first material is mixed with barium zirconate through mixing equipment; the first material is added to 15% distilled water for wet kneading for 60 minutes to obtain the second material, and the second material is passed through a 40-mesh screen to obtain the third material; The three materials are dried until the moisture content is less than 0.5% of the total mass of the third material, and the fourth material is obtained through a 40-mesh screen again; talc powder is added to the fourth material, and the material is formed by a rotary tablet press.

Figure 2 shows the morphology of the residue after combustion of the gas generant composition tablet in Example 1 of the present invention; Table 2 below shows the soluble residue and insoluble residue of the gas generant composition tablet in Example 1 of the present invention after combustion. Weight and low-temperature ignition delay time statistics; from Figure 2 and Table 2, it can be seen that the shape of the tablet after high-temperature combustion is the original tablet shape. And it has harder strength and higher density to support it to maintain its original appearance. Its low temperature ignition time meets the requirement of less than 7ms.

Table 2

In this example, barium zirconate was added as a slag-forming agent, basic copper nitrate was used as the main oxidant, guanidine nitrate was used as the fuel, AP and strontium nitrate were used as auxiliary oxidants, and talc was used as a lubricant and mold release agent. After the device test, the tablet maintained a very good original appearance. After the TANKWASH test, the weight of water soluble and insoluble matter decreased significantly. At the same time, the burning speed of the composition is increased, and the ignition delay meets the strict requirements of USCAR.

Comparative example 2

Guanidine nitrate 52%

Basic copper nitrate 44%

Strontium titanate 4%

After these components are weighed, they are pressed into a 5mm diameter and 1.9mm thick disc by wet granulation and a rotary tablet press. The specific preparation method is: guanidine nitrate, basic copper nitrate and strontium titanate are mixed by mixing equipment Afterwards, the first material is obtained; the first material is added to 10% distilled water for wet kneading for 50 minutes to obtain the second material, and the second material is passed through a 35 mesh screen to obtain the third material; the third material is dried and dried Until the water content is less than 0.5% of the total mass of the third material, the fourth material is obtained through a 35-mesh screen again; talc powder is added to the fourth material, and the material is formed by a rotary tablet press.

The prepared discs are loaded into the test generator, and the ignition and combustion test is carried out. After the test, the generator was dissected and the shape of the tablet after burning was observed.

Figure 3 shows the morphology of the residue after combustion of the gas generant composition tablet in Comparative Example 2 of the present invention; Table 3 below shows the soluble residue and insoluble residue of the gas generant composition tablet in the present invention after combustion. Weight and low-temperature ignition delay time statistics; from Figure 3 and Table 3, it can be seen that the tablets are in the form of flakes and part of powder, which are close to the inner wall of the filter, and their density is poor, which will easily cause them to fly out of the generator filter and fall on the airbag In the medium, it may ablate the air bag and bring potential danger to the human body. Its low temperature ignition time meets the requirement of less than 7ms.

table 3

Example 2

Guanidine nitrate 50%

Basic copper nitrate 41.5%

Strontium nitrate 1.5%

Ammonium perchlorate 2%

Strontium Zirconate 4%

Talc 1%

After these components are weighed, they are compressed into a 5mm diameter and 1.9mm thick disc by wet granulation and a rotary tablet press. The specific preparation method is: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate After mixing with strontium zirconate and talc powder through mixing equipment, the first material is obtained; the first material is added to 10% distilled water for wet kneading for 50 minutes to obtain the second material, and the second material is passed through a 35-mesh screen to obtain the third material ; Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and then pass through a 35-mesh screen to obtain the fourth material; add talc to the fourth material and use a rotary tablet press Material shaping.

Figure 4 shows the morphology of the residue after combustion of the gas generant composition tablet in Example 2 of the present invention; Table 4 below shows the soluble residue and insoluble residue of the gas generant composition tablet in Example 2 of the present invention after combustion. Statistics of weight and low-temperature ignition delay time; from Figure 4 and Table 4, it can be seen that the tablet is in the form of the original tablet after high-temperature combustion, and has a significant coagulation effect. The residue is close to the inner wall of the filter. Very good original morphology, with harder strength and higher density to support it to maintain its original morphology. Its low temperature ignition time meets the requirement of less than 7ms.

Table 4

In this example, strontium zirconate was added as a slag-forming agent, basic copper nitrate was used as the main oxidant, guanidine nitrate was used as fuel, AP and strontium nitrate were used as auxiliary oxidants, and talc was used as a lubricant and release agent. After the device test, the tablet maintained a very good original appearance. After the TANKWASH test, the weight of water soluble and insoluble matter decreased significantly. At the same time, the burning speed of the composition is increased, and the ignition delay meets the strict requirements of USCAR.

Comparative example 3

Guanidine nitrate 45%

Basic copper nitrate 40%

Potassium perchlorate 5%

Copper oxide 4%

Silica 5%

Calcium stearate 1%

After these components are weighed, they are compressed into a disc with a diameter of 5mm and a thickness of 1.9mm by wet granulation and a rotary tablet press. The specific preparation method is: guanidine nitrate, basic copper nitrate, copper oxide, potassium perchlorate, and two Silicon oxide and calcium stearate are mixed through mixing equipment to obtain the first material; the first material is added to 10% distilled water for wet kneading for 50 minutes to obtain the second material, and the second material is passed through a 30-mesh screen to obtain the third material ; Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and then pass through a 30-mesh screen to obtain the fourth material; add talcum powder to the fourth material and proceed through a rotary tablet press Material shaping.

Figure 5 shows the morphology of the residue after combustion of the gas generant composition tablet in Comparative Example 3 of the present invention; Table 5 below shows the soluble residue and insoluble residue of the gas generant composition tablet in the present invention after combustion. Weight and low-temperature ignition delay time statistics; from Figure 5 and Table 5, it can be seen that agglomeration occurs after the tablet is burned, and a large amount of metallic copper is tinned out, which is attached to the inner wall of the filter. It is easy to fly out of the generator filter and fall into the air bag, which may ablate the air bag and bring potential danger to the human body. Its low temperature ignition time meets the requirement of less than 7ms.

table 5

Example 3

Guanidine nitrate 45%

Basic copper nitrate 40%

Strontium nitrate 4%

Ammonium perchlorate 5%

Calcium zirconate 5%

Calcium stearate 1%

After these components are weighed, they are compressed into a disc with a diameter of 5mm and a thickness of 1.9mm by wet granulation and a rotary tablet press. The specific preparation methods are: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, Calcium zirconate and calcium stearate are mixed through mixing equipment to obtain the first material; add the first material to 10% distilled water for wet kneading for 50 minutes to obtain the second material, and pass the second material through a 30-mesh screen to obtain the third material. Material; Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and pass through a 30-mesh screen again to obtain the fourth material; Add talc to the fourth material and pass through a rotary tablet press Carry out material shaping.

Figure 6 shows the morphology of the residue after combustion of the gas generant composition tablet in Example 3 of the present invention; Table 6 below shows the soluble residue and insoluble residue of the gas generant composition tablet in Example 3 of the present invention after combustion. Weight and low-temperature ignition delay time statistics; from Figure 6 and Table 6, it can be seen that the form of the tablet after high-temperature combustion is the original tablet shape, which has a significant coagulation effect. Very good original morphology, with harder strength and higher density to support it to maintain its original morphology. Its low temperature ignition time meets the requirement of less than 7ms.

Table 6

In this example, calcium zirconate is added as a slag-forming agent, basic copper nitrate is used as the main oxidant, guanidine nitrate is used as fuel, AP and strontium nitrate are used as auxiliary oxidants, and calcium stearate is used as a lubricant and mold release agent. After the airbag generator test, the tablet maintained a very good original appearance. After the TANKWASH test, the weight of water soluble and insoluble matter decreased significantly. At the same time, the burning speed of the composition is increased, and the ignition delay meets the strict requirements of USCAR.

Example 4

Guanidine nitrate 51.5%

Basic copper nitrate 35%

Strontium nitrate 6%

Ammonium perchlorate 3%

Strontium Zirconate 2%

Barium zirconate 2%

Magnesium stearate 0.5%

After these components are weighed, they are compressed into a disc with a diameter of 5mm and a thickness of 1.9mm by wet granulation and a rotary tablet press. The specific preparation methods are: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, Strontium zirconate, barium zirconate, and magnesium stearate are mixed by mixing equipment to obtain the first material; add 10% distilled water to the first material for wet kneading for 60 minutes to obtain the second material, and pass the second material through a 40-mesh sieve Net to obtain the third material; dry the third material until the water content is less than 0.5% of the total mass of the third material, pass through a 40-mesh screen again to obtain the fourth material; add talc powder to the fourth material, pass Rotary tablet press for material forming.

Figure 7 shows the morphology of the residue after combustion of the gas generant composition tablet in Example 4 of the present invention; Table 7 below shows the soluble residue and insoluble residue of the gas generant composition tablet in Example 4 of the present invention after combustion. Weight and low-temperature ignition delay time statistics; from Figure 7 and Table 7, it can be seen that the tablets are in the form of original tablets after high-temperature combustion, and have a significant coagulation effect. Very good original morphology, with harder strength and higher density to support it to maintain its original morphology. Its low temperature ignition time meets the requirement of less than 7ms.

Table 7

In this embodiment, strontium zirconate and barium zirconate are added as slag-forming agents, basic copper nitrate is used as the main oxidant, guanidine nitrate is used as fuel, AP and strontium nitrate are used as auxiliary oxidants, and magnesium stearate is used as lubricant and mold release agent. After the airbag generator test, the tablet maintained a very good original appearance. After the TANKWASH test, the weight of water soluble and insoluble matter decreased significantly. At the same time, the burning speed of the composition is increased, and the ignition delay meets the strict requirements of USCAR.

Example 5

Guanidine nitrate 55%

Basic copper nitrate 28%

Strontium nitrate 4%

Ammonium perchlorate 7%

Zirconium silicate 4%

Talc 2%

After these components are weighed, they are compressed into a disc with a diameter of 5mm and a thickness of 1.9mm by wet granulation and a rotary tablet press. The specific preparation methods are: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, Zirconium silicate and talc powder are mixed through mixing equipment to obtain the first material; add the first material to 10% distilled water for wet kneading for 55 minutes to obtain the second material, and pass the second material through a 35-mesh screen to obtain the third material; Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and pass through a 35-mesh screen again to obtain the fourth material; add talc to the fourth material, and pass the material through a rotary tablet press forming.

Figure 8 shows the morphology of the residue after combustion of the gas generant composition tablet in Example 5 of the present invention; Table 8 below shows the soluble and insoluble residues of the gas generant composition tablet in Example 5 of the present invention after combustion. Statistics of weight and low-temperature ignition delay time; from Figure 8 and Table 8 we can see that the tablets are in the form of original tablets after high-temperature combustion, and have a significant coagulation effect. Very good original morphology, with harder strength and higher density to support it to maintain its original morphology. Its low temperature ignition time meets the requirement of less than 7ms.

Table 8

In this example, zirconium silicate was added as a slag-forming agent, basic copper nitrate was used as the main oxidant, guanidine nitrate was used as fuel, AP and strontium nitrate were used as auxiliary oxidants, and talc was used as a lubricant and release agent. After the device test, the tablet maintained a very good original appearance. After the TANKWASH test, the weight of water soluble and insoluble matter decreased significantly. At the same time, the burning speed of the composition is increased, and the ignition delay meets the strict requirements of USCAR.

Example 6

Guanidine nitrate 48%

Basic copper nitrate 42%

Strontium nitrate 2.5%

Ammonium perchlorate 3%

Strontium Zirconate 1.5%

Zirconium silicate 2.5%

Talc 0.5%

After these components are weighed, they are compressed into a disc with a diameter of 5mm and a thickness of 1.9mm by wet granulation and a rotary tablet press. The specific preparation methods are: guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, Strontium zirconate, zirconium silicate and talc powder are mixed through mixing equipment to obtain the first material; add the first material to 10% distilled water for wet kneading for 60 minutes to obtain the second material, and pass the second material through a 40-mesh screen The third material; the third material is dried until the moisture content is less than 0.5% of the total mass of the third material, and the fourth material is obtained through a 40-mesh screen again; the fourth material is added with talcum powder and passed through rotary pressing The tablet machine performs material forming.

Figure 9 shows the morphology of the residue after combustion of the gas generant composition tablet in Example 6 of the present invention; Table 9 below shows the soluble residue and insoluble residue of the gas generant composition tablet in Example 6 of the present invention after combustion. Statistics of weight and low-temperature ignition delay time; from Figure 9 and Table 9, it can be seen that the form of the tablet after high-temperature combustion is the original tablet shape, which has a significant coagulation effect. Very good original morphology, with harder strength and higher density to support it to maintain its original morphology. Its low temperature ignition time meets the requirement of less than 7ms.

Table 9

In this embodiment, strontium zirconate and zirconium silicate are used as slag-forming agents, basic copper nitrate is used as the main oxidant, guanidine nitrate is used as fuel, AP and strontium nitrate are used as auxiliary oxidants, and talc is used as lubricant and mold release agent. After the airbag generator test, the tablet maintained a very good original appearance. After the TANKWASH test, the weight of water soluble and insoluble matter decreased significantly. At the same time, the burning speed of the composition is increased, and the ignition delay meets the strict requirements of USCAR.

In the above-mentioned comparative examples and examples of the present invention, three sets of parallel tests were performed and the average value was taken.

The above-mentioned gas generating agent composition is used in the gas generator of the structure of the present invention. For details, refer to the following embodiments:

Example 7

Referring to Figures 10, 12, and 13, the present invention includes an upper shell, a lower shell, an igniter seat, an igniter, an ignition shell, a filter, an ignition powder, and a gas generating powder. The igniter seat is embedded in In the lower shell, the igniter seat is connected to the igniter and the ignition shell. The lower shell 3 adopts a double cup design and is provided with a first cup body 3-1 and a second cup body 3-2. The upper shell 1 is connected to At the opening of the first cup body 3-1, the filter 2 is built in the first cup body, the bottom inner surface of the upper shell 1, the second cup body 3-2, the outer surface of the igniter seat 5, The outer surface of the ignition housing 7 and the inner surface of the filter 2 constitute a gas generating chemical chamber 4. The gas generating chemical chamber 4 contains a gas generating chemical 10, and the ignition housing contains an ignition chemical 9.

In a preferred embodiment of the present invention, the upper casing 1 adopts an inverted cup shape, and more than one vent hole 1-1 is uniformly arranged on the side wall of the cup body. The inner surface of the side wall of the cup body is pasted with a sealing foil 11, and the sealing The foil covers the vent 1-1. The ignition shell 7 adopts a long cylindrical structure, and a side wall of the long cylindrical structure is evenly arranged with a fire hole 7-1 for uploading.

The metal components of the pyrotechnic gas generator in the present invention: the upper shell 1, the lower shell 3, and the ignition shell 7 are all stretched out of low-carbon steel, and the thickness of the upper shell and the lower shell is usually 1.0mm~2.0 mm, the material uses cold-rolled steel sheet with a tensile strength greater than 300MPa, and the carbon content is required to be less than 0.2%. The thickness of the ignition shell 7 is generally 0.5 mm to 1.5 mm, and the material is a cold-rolled steel plate with a tensile strength greater than 300 MPa, and the carbon content is required to be less than 0.2%. The filter 2 is made by rolling more than one layer of metal material, and each layer of metal material is evenly arranged with a certain number of vents of a certain shape. The diameter of the vents is generally not more than 0.5mm, and the thickness of each layer of metal material is 0.1mm~ 1.0mm, there is a gap between the outer surface of the filter 2 and the side wall of the upper casing 1 as shown in Fig. 1 in this example. The sealing foil 11 is made of copper foil, aluminum foil, lead foil or non-metallic materials. The 5 part of the igniter base can be machined from low-carbon steel as required, and it is made by machining. The igniter base 5 is inserted into the lower shell 4, and the combined part of the two adopts interference fit, and the assembled ignition The base and the lower housing are joined together by laser welding; they can also be made of nylon injection molding. When nylon injection is used, the lower housing 3 and the igniter base 5 can be formed as a whole by injection molding. The reliability of the seal is ensured and the machining cost of the igniter seat is eliminated.

The ignition housing 7 of the pyrotechnic gas generator of the present invention connects the two into one body through the metal deformation of the igniter base 5. The filter 2 is placed in the first cup 3-1 of the lower shell 3, the filter 2 is coaxial with the first cup 3-1, the filter 2 is connected to the bottom surface of the first cup 3-1, and the upper shell 1 The bottom surface fits tightly. The upper shell 1 and the lower shell 3 are connected by laser welding. The inner diameter of the upper shell 1 matches the outer diameter of the opening of the first cup 3-1 of the lower shell 3. The fit fit, the assembled upper and lower shells are connected together by laser welding.

In order to reduce the initial output slope of the gas generator, the impact and failure of the gas generator are avoided. Based on the design of the lower shell as a double-cup body structure, the present invention performs a large number of designs on the shape of the gas-generating drug without limiting the formulation of the gas-generating drug. Research has found that if the combustion of the gas-generating tablet can be divided into two stages, The first stage is approximately equal surface combustion, and the second stage is reduced surface combustion, which can achieve the above objectives very well. After a lot of research, it is found that the shape of the gas generating drug is a mesoporous column with an elliptical cross section and the ratio of the major axis to the minor axis radius in the columnar cross section is greater than 1 (see Figure 12 and Figure 13), and the combustion can be divided into the above two stages. (For example, the cross-section is elliptical, or other shapes with a major axis and a minor axis). Figures 13 and 14 show the combustion process and the combustion surface curve of the gas generating drug with the major axis and minor axis radius ratio of 1.6. It can be seen from the figure that the drug type used in the present invention achieves staged combustion, and the traditional There is only one stage for the combustion of the medicine type. The traditional medicine type burns after 50 time units. The gas-producing medicine type of the present invention has a second stage of combustion after 50 time units. The staged combustion reduces the initial output slope of the generator.

Conclusive recommendations are given here. The specific value of the ratio of the major axis to the minor axis radius is calculated according to the system’s requirements for the output of the pyrotechnic gas generator and the charge of the gas generating agent. The thickness of the gas generating agent can also be calculated according to the system Adjust the output requirements of the pyrotechnic gas generator. When the pyrotechnic gas generator is working, the igniter 6 ignites the ignition powder 9, and the ignition powder 9 burns rapidly, and ignites the gas-producing powder 10 in the combustion chamber 4 through the flame transfer hole 7-1. The gas-producing powder 10 undergoes two combustion stages , The first combustion stage and the second combustion stage, adjust the ratio of the two combustion stages, thereby effectively reducing the initial output slope of the pyrotechnic gas generator. The size of the mesopore in the shape of the gas generating agent is given priority to select the range of the inner diameter of the mesopore greater than or equal to 1mm and less than or equal to 3mm. When the inner diameter of the mesopore is constant, the larger the ratio of the major axis to the minor axis, the longer the proportion of the second combustion stage. The lower the output slope. The radius ratio of the major axis to the minor axis is preferentially selected in the range of greater than or equal to 1.5 and less than or equal to 4 according to the requirements of the generator charge rate. The generator has a good inflation effect and has a small impact on the generator.

The pyrotechnic gas generator with the structure of the present invention uses the above-mentioned gas generating agent with good slag-forming effect of the present invention. The filter screen can be used with a weight of 110g to 120g, and the total weight of the generator can be reduced to 500g to 510g. There is no flame at 23°C. At a high temperature of 85°C, the flame is less than 50mm, which can meet the requirements of USCAR.

In this embodiment, the pyrotechnic gas generator with the above-mentioned structure is adopted, under the condition that the gas-generating drug formula and the charge amount remain unchanged, since the gas-generating drug using the formula of the present invention has a significant effect of condensing residue, the slag is formed The effect can be increased by 50%, and the filtration efficiency of the pyrotechnic gas generator filter can be significantly improved. A light-weight filter can be used to reduce the total weight of the gas generator. The weight of the filter of the pyrotechnic gas generator can be significant A reduction of 10% to 30% will significantly reduce the total mass of the gas generator by 10% to 30%, and at the same time solve the flame problem of normal temperature and high temperature.

Comparison

Using the original structure of the pyrotechnic gas generator, using the traditional formula, the filter weight is 140g to 150g, the total weight of the generator is 530g to 540g, and the flame experiment is performed. At 23°C, there is a flame, and at a high temperature of 85°C The flame is larger than 50mm and cannot meet the requirements of USCAR.

Example 8

Figures 16 and 17 are extended examples of the present invention. In this example, on the basis of Embodiment 7, there is no gap between the outer surface of the filter 2 and the side wall of the upper casing 1.

Example 9

A pyrotechnic gas generator for an airbag, comprising an upper shell, a filter, a lower shell, an igniter seat, an igniter, an ignition shell, a gas generating powder, and an ignition powder, wherein the igniter seat is embedded in the lower shell In the body, the lower shell is a cup structure with an opening and flanged outwards (for ease of presentation, the previous number is used in this example, and 3-2 is the main body of the lower shell. The cup structure is equivalent to the second cup in the previous example. , The flanging structure is equivalent to the first cup body 3-1) without side walls, the upper shell is fixedly connected to the outer end surface of the flanging structure; the inner surface of the bottom of the upper shell is pressed against the flanging structure The upper and lower end surfaces of the tight filter; the bottom inner surface of the upper casing, the side wall of the lower casing, the outer surface of the igniter seat, the outer surface of the ignition casing, and the inner surface of the filter constitute a gas generating chamber. In this example, there is no gap between the outer surface of the filter 2 and the side wall of the upper casing 1.

Example 10

In this example, on the basis of Embodiment 9, there is a gap between the outer surface of the filter 2 and the side wall of the upper casing 1.

The above are only the best specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or changes within the technical scope disclosed by the present invention. All replacements shall be covered within the protection scope of the present invention.

The content that is not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

The gas generator is characterized in that it includes an upper shell, a filter, a lower shell, an igniter seat, an igniter, an ignition shell, a gas generating powder, and an ignition powder. The igniter seat is embedded in the lower shell. It is characterized in that: the lower shell has a double-cup body structure and is composed of a first cup body and a second cup body with different inner diameters, and the inner diameter of the first cup body is larger than the inner diameter of the second cup body; the upper shell is connected At the opening of the first cup body; the bottom surface of the first cup body and the bottom inner surface of the upper shell press the upper and lower end surfaces of the filter; the bottom inner surface of the upper shell, the second cup body, the outer surface of the igniter seat, and the ignition The outer surface of the shell and the inner surface of the filter constitute a gas generating chamber;

The gas generating agent composition adopted by the gas generator includes the following components in mass percentage content:

The slag-forming agent is at least one zirconate, or at least one silicate, or a mixture of at least one zirconate and at least one silicate.
The gas generator according to claim 1, wherein the shape of the gas generating drug built in the gas generating drug chamber is a mesoporous columnar shape and the ratio of the major axis to the minor axis radius of the columnar cross section is greater than 1.
The gas generator according to claim 2, wherein the inner diameter of the middle hole is greater than or equal to 1 mm and less than or equal to 3 mm, and the ratio of the major axis to the minor axis radius is greater than or equal to 1.5 and less than or equal to 4.
The gas generator according to claim 1, wherein the filter is rolled by using more than one layer of metal material, and each layer of metal material has a thickness of 0.1 mm to 1.0 mm; The metal material plates of the layer are uniformly provided with vent holes, and the diameter of the vent holes is not more than 0.5mm.
The gas generator according to claim 1, wherein the ratio of the height of the filter to the height of the first cup is greater than 10.
The gas generator according to claim 1, wherein the upper shell is an inverted cup with respect to the lower shell, and more than one exhaust hole is evenly arranged on the side wall of the cup, and the side of the cup A sealing foil is pasted on the inner surface of the wall, and the sealing foil covers the vent hole.
The gas generator according to claim 6, wherein the inner diameter of the upper casing and the outer diameter of the opening of the first cup body are integrated by interference fit and welded.
The gas generator according to claim 1, wherein the thickness of the upper shell and the lower shell is 1.0mm～2.0mm, and the material uses cold-rolled steel plate with a tensile strength greater than 300MPa; the ignition shell A long cylindrical structure is adopted, and a fire hole is evenly arranged on the side wall of the long cylindrical structure; the thickness of the ignition shell is 0.5 mm to 1.5 mm, and the material is a cold-rolled steel plate with a tensile strength greater than 300 MPa.
The gas generator according to claim 1, wherein the igniter seat is inserted into the lower shell, and the combined part of the two adopts an interference fit and is connected by welding to form a whole.
The gas generator according to claim 1, wherein the ignition shell connects the two into one body through the metal deformation of the igniter base.
The gas generator according to claim 1, wherein the zirconate is one or a combination of strontium zirconate, barium zirconate, or calcium zirconate.
The gas generator according to claim 1, wherein the silicate is one or a combination of zirconium silicate or calcium silicate.
The gas generator according to any one of claims 1 to 12, wherein the slag-forming agent is a mixture of at least one zirconate and at least one silicate, the mixture of zirconate and silicate The mass ratio is 1:0.5-3; preferably 1:0.8-2.
The gas generator according to claim 13, wherein the slag-forming agent is a mixture of strontium zirconate, zirconium silicate and calcium silicate, and the mass ratio of the three is 1:0.2～1.5:0.3～1.5 , Preferably 1:0.3-1:0.5-1.
The gas generator according to claim 1 or 11, wherein the slag-forming agent is a mixture of strontium zirconate and barium zirconate, and the mass ratio of the two is 1:0.5-3, preferably 1:0.8- 2.
The gas generator according to any one of claims 1-12, wherein the lubricant is one of talc, graphite, calcium stearate, magnesium stearate, molybdenum disulfide or boron nitride Or combination.
The gas generator according to any one of claims 1-12, wherein: the particle size D90 of the ammonium perchlorate is not greater than 20 μm; the particle size D90 of the slag-forming agent is not greater than 5 μm; the basic nitric acid The particle size D90 of copper and lubricant is not more than 5μm.
The gas generator according to any one of claims 1 to 12, wherein the sum of the water content of each component of the gas generating agent composition is not more than 1% of the total mass of each component.
The gas generator according to any one of claims 1 to 12, wherein the gas generating agent composition is formed into a circular or elliptical sheet structure, a circular or elliptical columnar structure, a special-shaped sheet or Columnar structure, round or elliptical single-hole structure, round or elliptical porous structure, special-shaped single-hole or porous structure.
The gas generator according to claim 19, characterized in that: the diameter of the circular sheet-like structure is 3-15mm, and the height is 2-5mm; the diameter of the circular columnar structure is 3-15mm, and the height is 5~ 15mm; the inner diameter of the circular single-hole structure is 0.5~2.5mm, the outer diameter is 3-15mm, and the height is 3-15mm; the inner diameter of the oval single-hole structure is 0.5~2.5mm, the long diameter is 3-20mm, and the short diameter is 2-12mm. , The height is 3-15mm.
The gas generator according to any one of claims 1-20, wherein the gas generating agent composition is prepared by wet granulation, spray granulation or dry granulation; the specific preparation method of the wet granulation comprises the following steps :

(1) The first material is obtained after mixing guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate and a slag-forming agent;

(2) Add water to the first material for wet mixing to obtain the second material, wherein the amount of water added is 8% to 15% of the total mass of the first material;

(3) Pass the second material through a 10-40 mesh screen to obtain the third material;

(4) Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and pass the 10-40 mesh screen again to obtain the fourth material;

(5) Add lubricant to the fourth material to form the material.
The gas generator according to claim 21, characterized in that: in the step (1), guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate and slag-forming agent are mixed in a mixing device to obtain the first One material, the mixing time is ≥5min; the wet mixing time in the step (2) is 20min-60min; the wet mixing equipment is a kneader or a mixer.
The gas generator according to any one of claims 1 to 20, wherein the gas generating agent composition is prepared by wet granulation, and the specific preparation method includes the following steps:

(1) Mix guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, slag-forming agent and lubricant to obtain the first material;

(2) Add water to the first material for wet mixing to obtain the second material, wherein the amount of water added is 8% to 15% of the total mass of the first material;

(3) Pass the second material through a 10-40 mesh screen to obtain the third material;

(4) Dry the third material until the moisture content is less than 0.5% of the total mass of the third material, and pass the 10-40 mesh screen again to obtain the fourth material;

(5) The fourth material is formed into material.
The gas generator according to claim 23, characterized in that: in the step (1), guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, slagging agent and lubricant are carried out in a mixing device The first material is obtained by mixing, and the mixing time is greater than or equal to 5 min; the wet mixing time in the step (2) is 20-60 min; the wet mixing equipment is a kneader or a mixer.