CN101274614A - Gas generator - Google Patents

Abstract

The invention relates to a gas generator which comprises a main body which is internally provided with an ignition chamber, a combustion chamber and a filtration chamber; the main body is composed of an upper shell and a lower shell; the upper part of the lower shell is pressed into the lower part of the upper shell to form a ring band-shaped superposed peripheral face; a V-shaped welding bevel suitable for welding is formed by the radial-bent crown face of the upper shell and the upward circumferential face of the lower shell; the filtration chamber is composed of the outer wall of a filter screen and the inner circular ring of the upper shell; the ignition chamber is positioned next to the central position of the main body, and the vent holes of the combustion chamber are directly against the central position of the combustion chamber. The gas generator of the invention overcomes the defects of the prior art that shell distortion is needed to form an air flow passage, requirements on shell strength of the generator and the dimension of parts in the shell are high and distortion is comparatively large when the generator works, etc., and has the advantages that the establishment of initial pressure is fast, the internal pressure of the combustion chamber is low, the repetition of the pressure of an outlet is stable, filtration thereof is good, dust is less generated and the outlet temperature is low, and the generator is applicable to various gas generant, etc.

Description

Gas generator

Technical field

The present invention relates to a kind of gas generator that aeration gas flow is provided to the safety guard-safeguard buffer system of automobile.

Background technology

The safety guard-safeguard buffer system of automobile generally comprises impact microphone; controller; gas generator; airbag etc.; as shown in Figure 1; when automobile bumps; sensor is measured the inertial acceleration that automobile bumps and produces; and signal conducted to controller; controller is judged the size and the time length of crash acceleration; if the size of acceleration/accel and time length surpass or reach predetermined limit value; controller sends ignition signal and starts gas generator; gas generator starts the back a large amount of gases of generation and charges into airbag; airbag expands rapidly and is deployed in the occupant front, has avoided the occupant because other hard thing of inertial impact force and automobile collides and has produced injures and deaths.

Be better protection occupant, the safety guard-safeguard buffer system of automobile requires the initial pressure of gas generator to set up in fast, the combustion chamber to force down, and delivery pressure repeats to stablize, filters well, dust is few, temperature out is low.

U.S. Pat 6257617 provides adjustable-pressure air bag producer, utilize the Deformation control delivery pressure of gas generator, but the problem that this US Patent mainly exists is: (1) is because the producer internal pressure is higher, and is very high to the casing rigidity requirement, exists the potential safety hazard that housing breaks; (2) very high to the accessory size requirement of enclosure interior, there is poorly sealed problem in the accessory size error when big; (3) owing to need housing distortion to form gas channel, so the mechanical mechanics property of housing is bigger to the gas generant combustion effects in the combustion chamber, can not guarantee a stabilized combustion performance, and make the gas of generation can not obtain a stable delivery curve or feature; (4) because the filtering net in the combustion chamber is subjected to the combustion chamber dimensional restriction, the effect that can not well play cooling and filter, and the gentle residue of combustion that causes giving vent to anger is more, burns airbag easily, has the hidden danger to occupant's burn; Because distortion is bigger, producer might come off from system, the passenger is existed the danger of scald when (5) producer was worked.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, providing a kind of has initial pressure and sets up in fast, the combustion chamber and force down, delivery pressure is stable, filtration is good, temperature out is low, dust is few, and volume is suitable for the gas generator installed for a short time, the restriction between wire harness and the skipper's axis of orientation of avoiding lighting a fire of this gas generator.

Technical solution of the present invention: a kind of gas generator, be provided with ignition chamber, combustion chamber and filter chamber in the main body, gas generant is housed in the combustion chamber; Squib anchor fitting, squib, ignition powder are arranged in the ignition chamber, it is characterized in that: described main body is made of a upper shell and a lower house that is fitted in up and down together, the bottom that its lower house top is pressed into upper shell forms a ring-band shape and overlaps side face, and arc surface that upper shell radially bends and the lower house periphery that makes progress constitutes the V-type bevel for welding that is suitable for welding; Described filter chamber is made of the outer wall of filtering net and the interior annulus of upper shell, and cylindrical is ledge structure or N dome dot structure; Described ignition chamber is offset to one side of main center position, the ignition chamber center of aperture over against combustion chamber of giving vent to anger.

V-type bevel for welding welding back intensity is higher, because shape can make the weld seam molten bath darker, just in time can form a vee-type weld seam, has good tensile strength, and lower to the requirement of welding quality of fit simultaneously, therefore the bevel for welding than other type more can embody advantage; The tensile strength that this bevel for welding is good makes the present invention can bear higher interior pressure.

The biasing of ignition chamber can provide automobile safety air bag required desirable delivery pressure curve, the shortcoming that the curve that can avoid ignition chamber to occupy the gas generator at center is difficult to regulate.The air-cushion inflator that is used for the skipper position of prior art generally places the bearing circle center, and the igniting wire harness is subjected in the installation site and the restriction of steering shaft is difficult to install and adjust, and in use damages wire harness easily.And the ignition chamber biasing can be avoided the restriction of steering shaft, is easy to attachment point live wire bundle.

Evenly distributed on the annular side face of described upper shell have an air gate, and described air gate inboard is pasted with tinsel.The aperture of air gate can basis the gas generant performance requriements regulate.When the aperture increases interior pressure when can reduce producer and exciting, the interior pressure that then can increase producer is reduced in the aperture.

Described tinsel is corrosion-resistant steel, copper or aluminium foil, and being shaped as of tinsel is endless belt-shaped, and its width is 2～3 times of air gate aperture, can play sealing function like this.

Described upper shell top is a planar circumferential shape, and its outermost rounded edge is bent downwardly, and extends axially the back radial extension again and becomes a square platform.Planar circumferential shape has good processability, and the clamping location is simple, and it is convenient to measure; Square platform is convenient to be connected with other parts of gas-bag system then directly as butt flange; This body skin is to the invention provides a good profile space.

The bottom of described lower house is a planar circumferential shape, axially extends behind its outermost K/UP.Planar circumferential shape positioning and clamping is easy, is convenient to as reference plane; This lower house has played the effect in closed interior space for the present invention.

Described squib is by set collar and squib anchor fitting inwall flush fit, and being fixed is pressed in the bottom of squib anchor fitting.

The bottom stage of described squib anchor fitting is nested in the eccentric orfice of lower house, is the interference flush fit.

Described filtering net is an annular, is formed by the mould compacting of metal filament establishment back, perhaps form by expanded metal lath, punching net,

Described combustion chamber is the annulus combustion chamber that outer wall, combustion chamber lid and the dividing plate of inwall, the squib anchor fitting of filtering net constitutes, and the bottom of filtering net is respectively by lower house and dividing plate location simultaneously.

Its cylindrical of described filtering net is ledge structure or N dome dot structure, and wherein N is 2～10.

The present invention is by adopting the firing unit biasing and by in inner rational deployment, suitable step filtering net, the rational fixed limit of each assembly realized goal of the invention, and the present invention's advantage compared with prior art is:

(1) the abundant ingenious producer inner space that utilized of the present invention opens air gate at the upper shell side face, and the gas of Peng Zhanging directly enters airbag like this, to the occupant up to the safety precaution effect; At upper shell inner peripheral surface metal clad paillon foil, not only play the leak free effect, and after guaranteeing that gas generant is lighted, it is lower that the initial pressure of combustion chamber is set up fast, interior pressure simultaneously, solved housing because the problem of the high producer distortion of internal pressure.This mainly be because: after producer is activated, after gas generant is lighted, the pressure of combustion chamber increases sharply, the air communication filtering net, break through body skin inner peripheral surface tinsel and enter into airbag, the pressure that therefore breaks through tinsel is the enclosure interior pressure limit value, and it is not high to break through the pressure of tinsel, generally can be controlled between 5MPa～15MPa, also just solve the high-voltage problem of enclosure interior.

(2) comformability is strong, can adapt to the gas generant performance requriements of different combustion speed.Because the aperture of air gate and tinsel characteristic and combustion chamber internal pressure have linear relationship, produce the desired pressure delivery curve that is fit to buffer system work, and adopt the air gate in different apertures and the tinsel of varying strength can regulate combustion chamber prrassure.

(3) because filtering net has utilized the producer volume inside around, being fixed on gas generant directly as outer wall of combustion chamber fully like this, the producer volume is reduced; And filtering net is cylindrical shape, and cylindrical has step, can directly be positioned in the producer lower house, has more effectively reduced the gas generator volume.Filtering net can suitably be thickeied or increase density according to performance need, helps the cooling of high-temperature gas and the filtration of residue.

(4) location is reliable, and assembling is simple, convenient.Mode by lower house and dividing plate location filtering net has guaranteed the easy to assembly of gas generant.

(5) by the mode of ignition chamber biasing, help coordinating the grafting with signal wire harness plug, be convenient to the assembling of assembly; Improved the ignitability of this producer simultaneously, better pressure delivery curve can be provided.

(6) upper and lower casing of the present invention and squib anchor fitting all adopt suitable carbon steel material, cooresponding erosion resisting performance is not only arranged, and reduced cost effectively, have improved the competitiveness of product in market.

The embodiment that provides below in conjunction with accompanying drawing is described in further detail the present invention.

Description of drawings

Fig. 1 is a safety guard-safeguard buffer system workflow diagram;

Fig. 2 is a structural representation of the present invention;

Fig. 3 is a working state schematic representation of the present invention;

Fig. 4 looks cutaway view for filtration host of the present invention;

Fig. 5 is the birds-eye view of filtering net of the present invention;

Fig. 6 is the pressue-graph (+23 ℃) after the present invention lights a fire in the 60L leakproof tank;

Fig. 7 is the filter screen structure scheme drawing after the work of the present invention.

The specific embodiment

As Fig. 2, shown in Figure 3, main body 1 of the present invention is made of a upper shell 18 and a lower house 10 that is fitted in up and down together, the similar inverted cup-shaped of upper shell 18, and its top is a planar circumferential shape 17, its circumferential outermost is bent downwardly, and extends axially the back radial extension again and becomes a square platform 19.The periphery 36 of upper shell 18 is an annular arrangement, air gate 2 is evenly distributed on the periphery 36 of upper shell 18 by merry-go-round arrangement, the square platform of the flange of upper shell 18 19 positions are at air gate 2 times (referring to Fig. 2), the effect of square platform 19 is to be used as butt flange, is convenient to the present invention and is connected with the modular device of gas-bag system.Air gate 2 inboards on upper shell 18 peripheries, pasting layer of metal paillon foil 3, this tinsel 3 is the banded paillon foil of corrosion-resistant steel annular, and width is 2 times of air gate 2 apertures, just in time the outside of pore and isolated the coming in inside of producer can be guaranteed the sealing of producer in-to-in.

The bottom of lower house 10 is a planar circumferential shape, and lower house 10 is made up of bottom surface 20 and the ring-type periphery 21 that makes progress, and lower house 10 has an eccentric orfice 39 for an eccentric side position, and is suitable with squib anchor fitting bottom stage 22 sizes, is interference fit.Axially extend behind the 20 outermost K/UPs of bottom surface.Lower house 10 upwards the external diameter of periphery 21 and upper shell 18 periphery 36 internal diameters about equally, one ring-band shape coincidence side face is formed at the bottom that lower house 10 tops are pressed into upper shell 18, and arc surface 38 that upper shell 18 radially bends and lower house 10 upwards periphery 21 constitute the V-type bevel for welding 35 that is suitable for welding.

Be provided with combustion chamber 31, filter chamber 32 around central axis in the main body 1, eccentric position is provided with ignition chamber 34, squib anchor fitting 25, squib 12, ignition powder 9, small end lid 8 are arranged in the ignition chamber 34, set collar 11 is pressed between the middle part periphery 37 of squib 12 and squib anchor fitting 25 squib 12 is fixed, the small end at ignition chamber 34 tops lid 8 is sealed in ignition powder 9 in the squib anchor fitting 25, and the flange circular arc 40 by squib anchor fitting 25 upper end peripheries 24 covers 8 spacing chuckings with small end.Ignition powder 9 is the boron potassium nitrate of tablet or powdery.

Squib anchor fitting 25 is a tubular structure, by upper end periphery 24 and middle part periphery 37, inner conical surface 14, bottom periphery 27, bottom stage 22 is formed, the aperture 30 of giving vent to anger that symmetrical distribution is arranged on the squib anchor fitting 25 middle part peripheries 37 is as outlet passageway, ignition chamber 34 and squib anchor fitting 25 space outerpaces have been communicated with, aluminium foil 33 adhering and sealings of aperture 30 outsides usefulness annular of giving vent to anger, the aperture 30 of giving vent to anger faces the central axis 16 of combustion chamber, the bottom stage 22 of squib anchor fitting 25 bottom surfaces and eccentric orfice 39 sockets of lower house 10 bottom surfaces are interference fit.With laser welding squib anchor fitting 25 and lower house 10 are combined as a whole, played sealing function simultaneously ignition chamber 34.

Combustion chamber 31 is the annulus combustion chamber that outer wall, asbestos mat 5, combustion chamber lid 6 and the dividing plate 15 of inwall, the ignition chamber 34 of filtering net 4 constitutes, encircle be centered around central axis 16 around, the lower end step of filtering net 4 is nested into upwards periphery 21 inboards of lower house 10 simultaneously, the two size is suitable, be interference fit, dividing plate 15 is positioned at combustion chamber 31 bottoms again, can be nested into filtering net 4 inboards, dividing plate 15 cylindricals are suitable with filtering net 4 inside dimensions; Gas generant 7 is housed in the combustion chamber 31.Combustion chamber lid 6 is positioned at top of combustion chamber, is made up of end face 28 and side face 29, and end face 28 is flat circumferential, and side face 29 external diameters equate substantially that with filtering net 4 inner peripheral surface internal diameters the side face 29 of combustion chamber lid 6 can be nested in the filtering net 4.Dividing plate 15 off-centre have the flat groove 23 of a circular hole, and middle part periphery 37 external diameters of squib anchor fitting 25 can be enclosed within the middle of the flat groove of circular hole 23, and free-running fit with it.13 short circuit sockets.26 is the small rubber pad.

Filter chamber 32 is made of the interior annulus of the periphery 36 of the outer wall of filtering net 4 and upper shell 18.

Circumference V-type bevel for welding 35 places in upper shell 18 and lower house 10 formation use laser-beam welding machine along this chamfered welding, thereby constitute complete gas generator.

Shown in Fig. 4,5, filtering net 4 is a loop configuration, and cylindrical has step, is made up of periphery 43 and step periphery 44.Filtering net 4 is fixed in the lower house as the combustion chamber chamber outer wall, and the external diameter and the lower house internal diameter of filtering net 4 step peripheries 44 are suitable substantially, and filtering net 4 step peripheries 44 can be inserted in the side face inboard at lower house.Filtering net 4 outer peripheral faces and upper shell air gate have a fixed gap, and filtering net 4 inner peripheral surfaces directly constitute combustion chamber wall, can give full play to the cooling of filtering net and the effect of filtration.The upper surface 41 of filtering net 4 and lower surface 42 are the circle scalene cone, have avoided interfering with the interior circular arc generation of upper shell and lower house in assembling.

When crashing, when the acceleration/accel of generation met or exceeded the preset limit value of controller, the present invention was just started by the ignition signal that air bag system sends, referring to the airflow arrows direction of Fig. 3.After ignition powder 9 was lighted, high temperature gas flow broke through aluminium foil 33 on squib anchor fitting 25 side faces by the aperture 30 of giving vent to anger, and enters into combustion chamber 31.Gas generant 7 in the high temperature gas flow ignition combustion chamber 31, gas generant 7 burnings produce a large amount of gases, in osed top combustion chamber 31, form high pressure, at the pressure of combustion chamber 31 between 5MPa～20MPa, by filtering net 4, break through the tinsel 3 on upper shell 18 inner peripheral surfaces in this high pressure downstream again, enter into then in the airbag of air bag system, airbag expands and launches, and the occupant is played the safety precaution effect.

Producer is used the current point fire in insulation under 23 ℃ of temperature after 4 hours in the 60L leakproof tank, data as shown in Figure 6.

Container inner pressure is P _2max=0.162MPa reaches P _2max95% time t _95%max=51.7ms, container pressure time of origin 6.1ms.A large amount of solid residues that filtered online collection, as shown in Figure 7.

Claims (10)

1. a gas generator is provided with ignition chamber (34), combustion chamber (31) and filter chamber (32) in the main body (1), and gas generant (7) is housed in the combustion chamber (31); Squib anchor fitting (25), squib (12), ignition powder (9) are arranged in the ignition chamber (34), it is characterized in that: described main body (1) is made of a upper shell (18) and a lower house (10) that is fitted in up and down together, the bottom that its lower house (10) top is pressed into upper shell (18) forms a ring-band shape and overlaps side face, the arc surface that upper shell radially bends (38) and the lower house V-type bevel for welding (35) that periphery (21) formation is suitable for welding that makes progress; Described filter chamber (32) is made of the outer wall of filtering net (4) and the interior annulus of upper shell (18), and its cylindrical is ledge structure or N dome dot structure; Described ignition chamber (34) is offset to one side of main body (1) center, the ignition chamber center of aperture (30) over against combustion chamber (31) of giving vent to anger.

2. gas generator according to claim 1 is characterized in that: the periphery (36) of described upper shell (18) is gone up the evenly distributed air gate (2) that has, and described air gate (2) inboard is pasted with tinsel (3).

3. gas generator according to claim 2 is characterized in that: described tinsel (3) is corrosion-resistant steel, copper or aluminium foil, and being shaped as of tinsel (3) is endless belt-shaped, and its width is 2～3 times of air gate (2) aperture.

4. gas generator according to claim 1 is characterized in that: described upper shell (18) top is a planar circumferential shape, and its outermost rounded edge is bent downwardly, and extends axially the back radial extension again and becomes a square platform.

5. gas generator according to claim 1 is characterized in that: the bottom of described lower house (10) is a planar circumferential shape, axially extends behind its outermost K/UP.

6. gas generator according to claim 1 is characterized in that: described squib (12) is by set collar (11) and squib anchor fitting (25) inwall flush fit, and being fixed is pressed in the bottom of squib anchor fitting (25).

7. gas generator according to claim 1 is characterized in that: the bottom stage (22) of described squib anchor fitting (25) is nested in the eccentric orfice (39) of lower house, is the interference flush fit.

8. gas generator according to claim 1 is characterized in that: described filtering net (4) is annular, is formed by the mould compacting of metal filament establishment back, perhaps form by expanded metal lath, punching net,

9. gas generator according to claim 1, it is characterized in that: described combustion chamber (31) is an annulus combustion chamber of outer wall, combustion chamber lid (6) and dividing plate (15) formation of the inwall of filtering net (4), squib anchor fitting (25), and the bottom of filtering net (4) is respectively by lower house (10) and dividing plate (15) location simultaneously.

10. gas generator according to claim 1 is characterized in that: its cylindrical of described filtering net (4) is ledge structure or N dome dot structure, and wherein N is 2～10.

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