CN2719659Y - Safety air bag electric igniting tube - Google Patents

Abstract

The utility model relates to a safety air bag electric igniting tube, which is characterized in that an igniting mechanism comprises an insulating layer formed by sintering glass fiber, a metal core positive electrode that is arranged at the middle of the insulating layer and a copper annular negative electrode, and the periphery of the insulating layer is covered by the copper annular negative electrode. The contact points of the positive electrode and the negative electrode are connected by a bridge wire. The safety air bag electric igniting tube can effectively prevent detonating mistakenly caused by static electricity and radio frequency; meanwhile the safety air bag electric igniting tube can provide high reliability of ignition.

Description

The safety air bag squib

[technical field]

The utility model relates to a kind of safety air bag squib.

[background technology]

Along with increasing of electronic product on the automobile, and extraneous electronic environment becomes increasingly complex, and the application of safety air bag has just been proposed new requirement, promptly be allowed to condition at continuous enhancing and the electromagnetic environment be on the increase in still can reliable operation, to bring into play its protective effect.

At present, common safety air bag is traditional bridge silk energising ignition device with the squib employing, and the bridge silk of promptly burn-oning on bipolar electrode is given on the bridge silk and dipped in igniter again, and encapsulation is afterwards used.The profile of this squib as shown in Figures 1 and 2, inner structure is as shown in Figure 3.Wherein, each element numbers is: 1---base, 2---electrode, 3---electrode plug, 4---contact, 5---powder charge broad-mouthed receptacle for holding liquid, 6---igniter, the last shell of 7---, 8---liner, the unsettled bridge silk of 9---.

Please continue to consult Fig. 4 to Fig. 5, be respectively the electrode and the basic circuit thereof of simplification, the ignition principle of this squib is: when automobile serious head-on crash takes place reaches the setting value that safety air bag detonates, ECU switches on to squib, be that 0.028 millimeter, resistance are bridge silk (nichrome wire) energising of 1.8-2.2 ohm promptly to diameter, the heating of bridge silk reaches aglow state and lights the igniter that covers on it, thereby finishes its igniting mission.

For preventing that static or radio frequency from igniting squib, when making the electrode plug of fixed electorde, need give admixture graphite in the plastics, be in state of insulation to realize electrode plug in low voltage following time, electric current then flows through the bridge silk and realizes igniting; Electrode plug is breakdown when high potential effects such as static or radio frequency, and static or radio frequency are released by the electrode plug breakdown channel, does not then have enough big electric current to pass through in the bridge silk, the squib combustion miss, thus guaranteed safety.

As from the foregoing, bridge silk in this structure will reliably be welded in the end of two electrodes, the length of bridge silk has determined resistance sizes, two distance between electrodes should be considered to prevent to produce spark and ignite squib between two electrodes, to consider also to guarantee that the resistance of bridge silk is between 1.8-2.2 ohm, finally can only make two electrodes at a distance of about 1mm after the balance, then can only allow the bridge silk unsettled; For preventing static or radio frequency ignition squib, in the plastics of injection moulding electrode plug, need admixture electrically conductive graphite powder in addition.

The electrode diameter of this squib is generally 1 millimeter, the bridge filament diameter is 0.028 millimeter, the end difficulty that the bridge silk will reliably be welded in two electrodes is very big, must guarantee that two distance between electrodes are very accurate because finish the words of weldering bridge silk task with mechanical equipment, and fact proved in the electrode plug injection moulding process and to be difficult to accomplish this point because of influences such as the temperature of plastics, dwell times, and therefore easy pressurized of electrode or bump and be out of shape can only finish weldering bridge silk by hand.Manual precision is generally again than the repair and maintenance card, so the resistance scattered error is bigger, and can only scrap above the product of 1.8-2.2 ohm scope.Because the bridge silk is unsettled, easily make the injured even disconnection of bridge silk when dipping in igniter and in the normal use of product, increased reject rate again, also brought huge potential safety hazard to the user.

The quality of electrode plug has determined the electrostatic prevention and the RF capabilities of squib, and the quality of electrode plug mainly is subjected to the influence of content, distribution situation and the injection moulding density etc. of electrically conductive graphite in plastics.Electrically conductive graphite to be evenly distributed in plastics, the closely knit unanimity of injection moulding itself is exactly very complicated thing.In actual production,, generally want first test portion for guaranteeing product design, soon certain batch of material has a fling at tens products earlier, surveys could begin after its insulativity meets the demands to produce, and wants every aborning and survey its insulation resistance, up-to-standardly just can be used to weld electric bridge, otherwise must scrap.The unstable properties of conductive engineering plastics is a global difficult problem at present in addition, does not still have the actv. solution.As seen, the control technological parameter is difficult in the production, and reject rate is higher.

As seen, the shortcoming of the squib of this structure is the processing technology complexity, and yields is low, and product reliability is not high, and for this reason, the said goods is real to be further improved.

[utility model content]

Technical problem to be solved in the utility model is, a kind of safety air bag squib is provided, and can prevent from effectively to misquote quick-friedly by static and radio frequency are caused, can also provide higher igniting reliability simultaneously, simplifies technology, improves yields.

For solving the problems of the technologies described above the utility model:

A kind of safety air bag squib, it is characterized in that: its ignition mechanism comprises by glass fibre double burned insulating barrier and is positioned at the middle metal-cored positive electrode of insulating barrier, with the copper ring-type negative potential that is coated on the insulating barrier periphery, and positive and negative electrode connects its contact by the bridge silk.

In the preferred scheme:

Contact on the described positive and negative electrode and bridge silk are to locate in one plane.

Described ring-type negative potential is a connected to chassis.

The thickness of described insulating barrier is set according to the requirement of electrostatic prevention and radio frequency.

The thickness of described insulating barrier is set according to the requirement of bridge wire resistance size.

The utlity model has following advantage:

(1) manufacturability is good, has particularly solved the difficult problem that traditional squib is difficult to weld electric bridge, can improve the production yields of product by a relatively large margin, is fit to mechanization production.

(2) ability of electrostatic prevention and radio frequency increases substantially, but and accuracy control.Use conductive engineering plastics in the traditional squib, because the inborn defective of this kind plastics is difficult to accurately control the degree of electrostatic prevention and radio frequency, want continuous test portion in the production and every product is screened, the cost height of wasting time and energy, and novel squib has been owing to carried out thorough improvement to conventional confguration, thus but the thickness of insulating layer that forms by control glass fibre sintering and accuracy control electrostatic prevention and RF capabilities.

(3) resistance precision is very high.The resistance value of traditional squib can vary in size because of the crooked or trend of bridge silk, and the utility model is owing to enlarged the area of contact of an electrode and bridge silk, minimum to eliminate the bridge silk by this groundwork crooked and move towards influence to resistance from resistance to utilize electric current, and can the igniting reliability of safety air bag further be improved by the resistance value of control thickness of insulating layer accuracy control squib.

(4) product reliability improves.The bridge silk of traditional squib is unsettled, can cause easily being shaken in the automobile sport disconnected because of the weight of deadweight and medicament after dipping in igniter, and structure jackshaft silk of the present utility model can be close to crash-resistant electrode plug surface, igniter also has certain reinforcement effect to the bridge silk after being bonded at the electrode plug surface, so product reliability is improved.

(5) simplify firing circuit, met car electrics circuit developing direction.The utility model only needs an ignition wire to get final product the method for normal operation owing to adopt one extremely directly to communicate with vehicle body, has therefore simplified circuit, has saved the interface of clock spring, has also improved the reliability of electric system, meets car electrics circuit developing direction.

(6) be fit to mechanization production.Weldering electric bridge operation is the most important operation that influences ignition tube production efficiency and quality, and the bridge silk of traditional squib will be welded in two small electrode end faces in the groove, and is very difficult, is difficult to realize mechanization production.And in the utility model because the innovation of structure only need in one plane be welded 2 points, this has become the common method that mechanization is produced in electron trade.

(7) the bad product of processing has obtained elimination to the hidden danger that the safety air bag effect forms.In the electrode plug of traditional squib conducting medium is arranged, because the instability factor affecting such as (ageings of plastics) in the homogeneity of its distribution and the long storage, product in use performance can drift about, and this repeatedly is proved in practice.And use copper material and glass instead owing to the conductive engineering plastics of having abandoned unstable properties in the utility model, because copper material and glass all are extremely stable common used materials, therefore product in use can not eliminated hidden danger in the design because of material influences product reliability.

[description of drawings]

Fig. 1 is the outside drawing one of common safety air bag squib;

Fig. 2 is the outside drawing two of common safety air bag squib;

Fig. 3 is the cut-away view of common safety air bag squib;

Fig. 4 is the electrode scheme drawing of the common safety air bag squib through simplifying;

Fig. 5 is the telegraph circuit schematic diagram of common safety air bag squib;

Fig. 6 is the outside drawing one of the utility model safety air bag squib;

Fig. 7 is the outside drawing two of the utility model safety air bag squib;

Fig. 8 is the cut-away view of the utility model safety air bag squib;

Fig. 9 is the electrode scheme drawing of the utility model safety air bag squib through simplifying;

Figure 10 is the telegraph circuit schematic diagram of the utility model safety air bag squib;

Figure 11 is the bridge silk part birds-eye view of common safety air bag squib;

Figure 12 is the bridge silk part birds-eye view of the utility model safety air bag squib;

Figure 13 is the bridge silk burr scheme drawing of common safety air bag squib;

Figure 14 is the bridge silk burr scheme drawing of the utility model safety air bag squib.

[specific embodiment]

In conjunction with example the utility model is described in further detail with reference to the accompanying drawings:

A kind of safety air bag squib of the utility model, its profile such as Fig. 6 are to shown in Figure 7, inner structure as shown in Figure 8, the design of employing unipods, promptly an electrode 11 (ring electrode, negative pole) directly contacts with shell, in actual use, squib will firmly be fixed on the shell of gas generator, the shell of gas generator fixes with bearing circle again, so ring electrode 11 joins and ground connection with vehicle body in fact, thereby has constituted the loop through ECU and storage battery and core electrode 15 (positive pole).The insulating barrier 16 that between core electrode 15 and ring electrode 11, forms for the glass fibre sintering of ring-type, but by controlling the releasable electrostatic potential of its thickness accuracy control (punching voltage's height when thickness is big; A thickness hour breakdown potential is forced down), therefore, this structure has very good anti-static and RF capabilities.

In addition, the core electrode contact 14 of this squib and ring electrode contact 12 are in one plane, therefore bridge silk 13 welds than being easier to, and is on two electrode contacts 4 that are welded in the groove unlike the suspension bridge silk 9 of common squib, thereby is easy to realize mechanization production.

Please continue to consult Figure 11 and Figure 12, the bridge silk is the iron cobalt nickel alloy silk, electrical resistivity is higher, its two ends contact with ring electrode and core electrode, according to resistance string rule in parallel, the thickness of the insulating barrier 16 that the glass fibre sintering forms in the utility model has determined the resistance sizes of squib, also determined simultaneously the size of electrostatic prevention preventing RF ability, and it is irrelevant with the right and wrong of bridge silk and trend, therefore the precision of resistance value is very high, can the reject rate in the production be descended greatly, even and efficient hand-manipulated also can significantly improve because of bridge silk stretching or crooked change the whether.

Squib must be cut redundance after welding the bridge silk, to stay burr after cutting unnecessary bridge silk, in actual production, find institute's burr that stays often than anticipation greatly because the bridge silk is a screw-shaped, be similar to common electric stove wire, when being cut off, have by the situation that drags and stretch.

By Figure 13 and Figure 14 as seen, residual burr is different to the performance impact of product.Because the shell of traditional squib is a non-conductive, therefore the shell of making time spent bridge silk burr and ignition tube and the conductive electrode plug distance that are subjected to static and radio frequency are very near, thereby easily form the loop, form loop back axle silk burr heating meeting flashpoint fire tube and lead to a disaster.But, because the ring electrode of squib of the present utility model itself is exactly an electrode, burr on it without any influence, has only the burr on the core electrode influential to properties of product to the properties of product nature, and its influence is similar to the principle of traditional squib burr influence.As seen, theoretically, in the process of actual production squib of the present utility model, bridge silk burr has reduced half to the traditional squib of the adverse effect likelihood ratio of product, but actual conditions far moreover.Traditional squib weldering bridge portion is in groove, bridge silk burr is difficult to clean out, and the weldering bridge portion of novel squib is on the surface, can see weldering bridge quality and burr clearly, therefore burr at utmost can be cleaned out, the production yields can improve greatly, and product safety hidden danger is eliminated substantially in the design.

The foregoing description just embodies the preferred version of technical solutions of the utility model, those skilled in the art to wherein some part some changes that may make all embodied principle of the present utility model, belong within the protection domain of the present utility model.

Claims (5)

1, a kind of safety air bag squib, it is characterized in that: its ignition mechanism comprises by glass fibre double burned insulating barrier and is positioned at the metal-cored positive electrode in the middle of the insulating barrier and is coated on the copper ring-type negative potential of insulating barrier periphery, and positive and negative electrode connects its contact by the bridge silk.

2, safety air bag squib as claimed in claim 1 is characterized in that: contact on the described positive and negative electrode and bridge silk are to locate in one plane.

3, safety air bag squib as claimed in claim 1 is characterized in that: described ring-type negative potential is a connected to chassis.

4, safety air bag squib as claimed in claim 1 is characterized in that: the thickness of described insulating barrier is set according to the requirement of electrostatic prevention and radio frequency.

5, safety air bag squib as claimed in claim 1 is characterized in that: the thickness of described insulating barrier is set according to the requirement of bridge wire resistance size.

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