JP2003341467A - Inflator with cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inflator with a cap easy to mount thereon. <P>SOLUTION: The outer surface including a first gas exhaust port 22 of a diffuser part 20 is covered with the cap 40 having a second gas exhaust port 45. The cap 40 is fixed into a ring groove 31 provided in the diffuser part 20 by caulking a minimum diameter portion 41b. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflator for a curtain of an automobile or the like, an inflator for a side airbag, and an airbag device using the inflator.

[0002]

2. Description of the Related Art An inflator for an inflatable safety system for a motor vehicle is designed to provide optimum occupant protection depending on the seat position in the vehicle such as the driver's seat and passenger seat. Inflators for driver airbags, passenger airbags, side airbag inflators, curtain inflators, knee bolster inflators, inflatable seatbelt inflators, tubular system inflators, pretensioner inflators, etc. Inflators are known. Among these inflators, the curtain inflator is designed to instantly inflate and deploy a curtain-shaped airbag having a thickness of about several cm to the window side of the vehicle when the vehicle receives a lateral impact.

The following are known as related prior art. For example, U.S. Pat. No. 5,527,066 discloses a device for expanding a flexible container by using helium and hydrogen together.
No. 6, discloses a gas flow device for an airbag using a pressurized inert gas.
No. 886 discloses an airbag device for inflating an airbag with nitrogen or helium.
No. 03,493 discloses a side inflator housing for an air bag in which a pressurized gas and a gas generating agent are used in combination, and registered utility model publication No. 3031246 uses argon or nitrogen as the pressurized gas. A pressurized gas inflator has been disclosed.

[0004] Various inflators are required to be smaller and lighter in order to reduce the weight of the vehicle itself, and are also required to improve workability, simplify the manufacturing process, and improve safety during operation. However, none of the above-mentioned conventional techniques can sufficiently satisfy all of these.

An object of the present invention is to provide an inflator with a cap, which can be reduced in size and weight, improve workability, and simplify the manufacturing process, and an airbag device using the inflator.

[0006]

As a means for solving the above problems, the present invention provides a tubular inflator having a closed end at one end and an opening at the other end, the inside of which is filled with a pressurized medium. The inflator housing has a housing and a diffuser portion fixed to the opening side of the inflator housing and having a first gas discharge port for discharging the pressurized medium flowing out from the opening during operation to the outside. The outflow path of the pressurized medium between the blower and the diffuser part is closed by a rupture plate, and the diffuser part is provided with means for breaking the rupturable plate, and the diffuser part is at least the first gas exhaust. Provided is an inflator with a cap, which covers an outer surface including an outlet and has a cap having an opening serving as a second gas discharge port by caulking.

By attaching the cap by crimping in this manner, the manufacturing process can be simplified as compared with the case where welding or the like is applied. Further, when the airbag is attached to the inflator, it is possible to obtain an effect that the caulked portion can be used for connection and fixation.

In the above invention, the cap has a minimum diameter portion provided on both sides in the length direction, a maximum diameter portion provided at a central portion in the length direction, and between the minimum diameter portion and the maximum diameter portion. It is a barrel-shaped member having a step portion provided, and it is preferable that the step portion or the maximum diameter portion has an opening serving as the second gas discharge port, and the minimum diameter portion is attached to the diffuser portion.

By providing the second gas outlet at the step portion, the maximum diameter portion, or both the step portion and the maximum diameter portion, the space for distributing the pressurized medium between the first gas outlet and the second gas outlet. Therefore, the ejection of the pressurized medium is not hindered.

In the above invention, it is preferable that the cap is attached by caulking either one or both of the minimum diameter portions in a groove provided on the peripheral surface of the diffuser portion. The groove provided on the peripheral surface of the diffuser portion is preferably a continuous groove (ring groove) that goes around the peripheral surface.

By mounting in the groove in this way,
In addition to being able to more firmly fix the cap to the diffuser portion, when the airbag is attached to the inflator, the groove (caulking portion) can be used for connection and fixation.

In the above invention, the total opening area of the second gas outlet is larger than the total opening area of the first gas outlet, and the total opening area of the second gas outlet is the total opening area of the first gas outlet. It is preferably 1.5 times or more.

By thus defining the total opening area of the first gas outlet and the second gas outlet, the jet pressure of the pressurized medium can be controlled by the first gas outlet.

In the above invention, the plurality of first gas outlets are provided, and at least two of the plurality of first gas outlets are arranged at positions symmetrical to each other in the width direction or at positions close thereto. It is preferable.

According to the present invention, when the diffuser portion has a circular cross section in the width direction and two or three or more first gas outlets are provided, at least two first gas outlets are located in the width direction. It is arranged so as to be symmetrical or nearly symmetrical in the (radial direction). When three first gas outlets are provided, the three outlets are evenly arranged at an angle of 120 °, and when four are provided, four outlets are 90 °.
It is desirable that they are evenly arranged at an angle of, and the same applies when five or more are provided.

When an unexpected situation occurs such that a fire or the like occurs during transportation and storage of the inflator, and the inflator malfunctions, if there is only one first gas outlet,
The pressurized medium ejected from there causes the inflator to jump out like a rocket, which is extremely dangerous. However, as described above, if the arrangement of at least two first gas outlets is adjusted, and if the arrangement of three or four or more first gas outlets is adjusted, the above-mentioned abnormal situation may occur. To be prevented.

In the above invention, the cylindrical inflator housing having a symmetrical shape with respect to the axial direction and the width direction is used, whereby the workability at the time of manufacturing is improved.

Further, as a means for solving the above-mentioned problems, the present invention provides an air provided with an operation signal output means including an impact sensor and a control unit, and a module case in which the inflator with the cap and the airbag are housed in the case. Provide a back device.

[0019]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the inflator 10 of the present invention in the length direction, and FIG. 2 is a view for explaining a mounting method by caulking a cap.

The inflator housing 12 has an opening 14 on one end side, and the other end side is closed by swaging or spinning. In the internal space 16 formed by the inflator housing 12 and the diffuser portion 20, a pressurized medium composed of an inert gas such as argon or helium or a nitrogen gas has a maximum pressure of 60,000 k.
It is filled with about Pa. Inflator housing 1
2 has a circular cross section in the width direction, and the opening 14 also has a circular shape.

The inflator housing 12 can be made symmetrical with respect to the axial direction and the width direction. The pressurized medium is stored in the inflator housing 12 and the diffuser portion 20.
, The seal pin 17 is inserted into the pores provided in the closed end face, and then the seal pin 1 is inserted.
Weld the pores together with 7 to completely close them.

Opening 14 of inflator housing 12
The diffuser section 20 is connected to the side, and the diffuser section 20 has a first gas discharge port 22 for allowing the pressurized medium to flow out. The first gas exhaust port 22 is not closed, and a screen 29 made of an annular metal net for removing the fragments of the rupturable plate 19 is arranged inside the first gas exhaust port 22.

The inflator housing 12 and the diffuser portion 20 may be connected by welding (welding portion 26) as shown in FIG. 1, or a male screw portion may be provided on the outer peripheral surface of the end portion of the inflator housing 12 to form the diffuser portion 20. A female screw portion may be provided on the inner peripheral surface of the end portion, and the male screw portion and the female screw portion may be screwed together for connection.

The outflow passage 18 of the pressurized medium in the diffuser portion 20 is closed by a rupture plate 19, and the internal space 16 of the inflator housing 12 is maintained in a high-pressure airtight state before the operation.

An igniter 25 having an ignition charge is provided in the diffuser portion 20 as a means for destroying the rupturable plate 19. The igniter 25 is used in the inflator housing 12
And the diffuser portion 20 are connected to each other, and the rupture plate 19 is attached to the diffuser portion 20 through one opening.
It is fixed by caulking the peripheral edge 28 of the one end opening of the diffuser portion 20 after the fitting. The igniter 25 is the inflator housing 1
It is attached coaxially with the central axis of 2.

A cap 40 is attached to the diffuser portion 20 so as to cover the outer surface including the first gas outlet 22. The cap 40 includes minimum diameter portions 41a and 41b provided on both sides in the length direction, a maximum diameter portion 43 provided at a central portion in the length direction, and minimum diameter portions 41a and 41b.
And the stepped portions 42a, 42 provided between the maximum diameter portion 43 and
It is a barrel-shaped member having b. The cap 40 is crimped at the minimum diameter portion 41b and is fixed in the ring groove 31. It is desirable to provide a flat surface or a recess on the outer surface side of the minimum diameter portion 41a in consideration of connectivity when the airbag is attached.

The outer peripheral surface of the diffuser portion 20 and the cap 4
A distribution space 46 including the outer peripheral surface of the diffuser portion 20 and the maximum diameter portion 43 of the stepped portions 42 a and 42 b is formed between the zero and 0. Therefore, the pressurized medium ejected from the first gas exhaust port 22 flows into the distribution space 46 and is then ejected from the second gas exhaust port 45 provided in the step portions 42a and 42b, so that all the first medium is ejected. The same amount of the pressurized medium is ejected from the 2 gas discharge port 45.

Since the second gas outlets provided in the step portions 42a and 42b and the first gas outlet 22 do not face each other, the pressurized medium flowing into the distribution space 46 is ejected radially. The second gas discharge port 22 can be provided only on the step portion 42a or only on the step portion 42b in order to adjust the ejection direction of the pressurized medium according to the inflation / deployment direction of the airbag, and also the maximum diameter portion. It can be provided only on 43, and can also be provided on the step portions 42a and 42b and the maximum diameter portion 43.

The diameter of the first gas outlet 22 is preferably smaller than the diameter of the second gas outlet 45, and the same applies when a plurality of each is provided. Therefore, the total opening area of the second gas exhaust port 45 is larger than the total opening area of the first gas exhaust port 22, and is adjusted to 1.5 times or more.

From the viewpoint of preventing the inflator 10 from jumping out like a rocket at the time of erroneous operation, the first gas discharge port 22 is provided with two first gas discharge ports 22 at positions symmetrical with respect to the radial direction, for example. Is preferred.

Next, a method of attaching the cap 40 to the inflator 10 will be described. First, as shown in FIG. 2, the cap 40 is fitted into the diffuser portion 20 from the igniter 25 side and adjusted so that the minimum diameter portion 41b and the ring groove 31 are aligned with each other. At this time, the end portion of the minimum diameter portion 41a is in contact with the opening edge 28 of the diffuser portion 20, and an O-ring 30 is arranged in the contact portion to maintain airtightness. After that, the portion of the minimum diameter portion 41b of the cap 40 in FIG. 2 is caulked and fixed in the ring groove 31 as shown in FIG.

An airbag device using the inflator 10 is a combination of an actuation signal output means including an impact sensor and a control unit, a module case in which the inflator 10 and the curtain-shaped airbag 50 are accommodated in the case, and the like. For example, Japanese Laid-Open Patent Publication No.
The configuration can be the same as that shown in FIG. 17 of Japanese Patent No. 334517.

When the airbag is connected to the inflator 10, the opening of the airbag is covered with the cap 40, and the cap 40 is caulked into the ring groove 31 (the minimum diameter portion 41).
A method of tightening and connecting with a fixing band at the portion b) can be applied. By fixing the opening of the airbag in the ring groove 31 in this manner, the connection strength between the airbag and the inflator 10 is increased. Further, if necessary, the minimum diameter portion 41a (where a flat surface or a recess is provided) is similarly tightened with a fixing band, so that the connection strength can be further increased.

Next, the operation of the airbag device using the inflator 10 will be described with reference to FIG. When the vehicle receives an impact, the igniter 25 is activated in response to a signal from the impact sensor, and the igniting charge is ignited and burned to destroy the rupturable plate 19. Since the outflow path 18 of the pressurized medium is opened by the destruction of the rupture plate 19, the pressurized medium in the internal space 16 is
The first gas discharge port 2 through the outflow path 18 and the filter 29
After flowing into the distribution space 46 from 2, the second gas outlet 45
Is ejected through and inflates the airbag. At this time, the fragments of the rupturable plate 19 are removed by the filter 29.

[0035]

INDUSTRIAL APPLICABILITY The inflator of the present invention is easy to assemble, can reduce the burden on the operator, and can increase the connection strength when connecting the airbag.

[Brief description of drawings]

FIG. 1 is an axial sectional view of an inflator of the present invention.

FIG. 2 is a view for explaining how to attach a cap in the inflator shown in FIG.

[Explanation of symbols]

10 inflator 12 Inflator housing 19 rupture disc 20 Diffuser section 22 First gas outlet 25 igniter 31 ring groove 40 cap 45 Second gas outlet

Claims (8)

[Claims] 1. A cylindrical inflator housing having a closed end at one end and an opening at the other end, the inside of which is filled with a pressurized medium, and an inflator housing fixed to the opening side at the time of operation. A diffuser portion having a first gas outlet for discharging the pressurized medium flowing out from the opening to the outside, and the outflow path of the pressurized medium between the opening portion of the inflator housing and the diffuser portion is ruptured. An inflator which is closed by a plate, and further includes a destruction means for the rupturable plate in a diffuser part, and the diffuser part covers an outer surface including at least a first gas discharge port and becomes a second gas discharge port. An inflator with a cap, to which a cap having an opening is attached by caulking. 2. The cap is provided between a minimum diameter portion provided on both sides in the length direction, a maximum diameter portion provided at a center portion in the length direction, and between the minimum diameter portion and the maximum diameter portion. 2. The cap according to claim 1, which is a barrel-shaped member having a stepped portion, an opening serving as a second gas outlet in the stepped portion or the maximum diameter portion, and is attached to the diffuser portion at the minimum diameter portion. Inflator. 3. The inflator with a cap according to claim 2, wherein the cap is attached by caulking one or both of the minimum diameter portions in a groove provided on the peripheral surface of the diffuser portion. 4. The inflator with a cap according to claim 1, wherein the total opening area of the second gas outlet is larger than the total opening area of the first gas outlet. 5. The total opening area of the second gas outlet is 1.5 times or more the total opening area of the first gas outlet.
An inflator with a cap according to any one of 4 above. 6. A plurality of first gas outlets are provided,
The inflator with a cap according to any one of claims 1 to 5, wherein at least two of the plurality of first gas discharge ports are arranged at positions symmetrical to each other in the width direction or at positions close thereto. 7. The inflator with a cap according to claim 1, wherein the tubular inflator housing is symmetrical with respect to the axial direction and the width direction. 8. An airbag provided with an actuation signal output means including an impact sensor and a control unit, and a module case in which the inflator with a cap according to any one of claims 1 to 7 and an airbag are housed. apparatus.