JPH07108894A - Trigger member of device for actuating air bag - Google Patents

Abstract

PURPOSE:To enable a trigger member to be fabricated with ease and high accuracy while ensuring its property of being actuated surely and stably and to enable cost reduction to a large extent. CONSTITUTION:A trigger lever 50 for use in an actuating device comprises a plate-shaped trigger portion 52 and a lever portion 54 formed by the curving of a rod into a U-shape, and the end portions 60 of the trigger lever serve as fulcrums of turning movement. Therefore the major part of the trigger level does not require machining for fabrication, and the simple structure of the trigger lever enables cost reduction to a large extent and facilitates fabrication at high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trigger member which is attached to a vehicle and is used in an airbag starting device for inflating a bag.

[0002]

2. Description of the Related Art In an airbag, for example, an airbag attached to a steering wheel, a starting device is provided so that the bag is inflated by the starting device so as to be interposed between the steering wheel and an occupant when the vehicle suddenly decelerates. Has become.

Here, as shown in FIG. 18, in a conventional starting device 130 of this type, a spherical ball 134 is housed in a cylinder 132, and one end of a drive shaft 136 is in contact therewith. A trigger shaft 138 is fixed to the middle portion of the drive shaft 136.

The trigger shaft 138 is composed of an ignition pin 1
40, and the shaft portion 142 is rotatably supported by the body of the starting device 130.
As a result, the drive shaft 136 can rotate around the axis of the trigger shaft 138 together with the trigger shaft 138.

On the other hand, the other end of the drive shaft 136 has a bias pin 1 provided with a bias spring 146.
Pressed by 48. Therefore, the drive shaft 136 normally holds the ball 134 in a predetermined position in the cylinder 132, and the trigger shaft 13
8 engages the ignition pin 140 and resists the urging force of the firing spring 150 to bring the ignition pin 140 into a locked state.

At the time of sudden deceleration of the vehicle or the like, the ball 134 housed in a predetermined position in the cylinder 132 moves by inertial force against the biasing force of the bias spring 146 in the direction of arrow A, which is the forward direction of the vehicle, to drive. The shaft 136 is rotated, the trigger shaft 138 fixed to the drive shaft 136 rotates counterclockwise, and the locking of the ignition pin 140 by the trigger shaft 138 is released, whereby the ignition pin 140 is fixed to the detonator 152. A bag (not shown) is inflated upon collision and ignition (for example, JP-A-60-248454 and JP-A-6-246454).
0-248455, JP-A-60-248456, JP-A-60-248457, etc.).

[0007]

By the way, in such a conventional starting device 130, as shown in FIG. 17, a trigger shaft 138 fixed to a drive shaft 136 is provided.
Is manufactured by cutting a large-diameter rod material to process the shaft portion 142 thereof, and then further flattening the trigger portion 154. For this reason, the shaft portion 142 can be manufactured with high accuracy to smoothly operate the trigger shaft 138 and stabilize the operation performance, but on the other hand, there are drawbacks that there are many cutting portions and the manufacturing is complicated and the cost is high.

In this case, the trigger shaft 138 may be manufactured by processing a plate material instead of the bar material in order to reduce the cutting portion and reduce the cost, but the plate material is cut and the shaft portion is cut. Since it is extremely difficult to manufacture this shaft portion with high precision, on the other hand, if the shaft portion is manufactured as a separate body and then fixed to the main body portion, the structure and manufacturing process still remain. It is complicated and rather expensive.

As described above, in order to manufacture the shaft portion 142 with high accuracy and stabilize the operation performance of the trigger shaft 138, the manufacturing is complicated and the cost is high, and the manufacturing is easy and the cost is low. However, the accuracy of the shaft portion 142 deteriorates and the operation of the trigger shaft 138 becomes unstable, which is a trade off.

In consideration of the above facts, the present invention is a trigger member for an air bag starting device, which can be manufactured easily and highly accurately while ensuring a reliable and stable starting property, and can greatly reduce the cost. The purpose is to provide.

[0011]

A trigger member of an airbag start-up device according to the present invention includes a mass body for detecting a sudden vehicle deceleration by inertial movement, a detonator for expanding a bag, and a collision with the detonator at all times. A trigger member used in an airbag starting device including an ignition pin urged in a direction to rotate, which is formed in a plate shape, engages with the ignition pin, prevents movement of the ignition pin, and rotates. By doing so, a trigger portion for releasing the movement prevention of the ignition pin, and a U-shaped trigger portion and an intermediate portion fixed to the trigger portion, U
The base end of the letter U engages with the mass body to hold the mass body at a predetermined position, and the tip of the U-shape comes into contact with the main body of the starting device to serve as a fulcrum of rotation, and the mass is used when the vehicle suddenly decelerates. A lever portion that is rotated together with the trigger portion by inertial movement of the body,
It is characterized by consisting of.

[0012]

In the trigger member of the airbag starting device having the above structure, the U-shaped base end portion of the lever portion is normally engaged with the mass body and held at a predetermined position, and the trigger portion serves as an ignition pin. Engages to prevent movement. At the time of sudden deceleration of the vehicle, the lever part is rotated together with the trigger part by the inertial movement of the mass body,
The trigger part releases the movement prevention of the ignition pin. This causes the ignition pin to collide with the detonator.

Since the trigger portion is formed in a plate shape and the U-shaped tip of the lever portion simply fixed to the trigger portion abuts on the main body of the starting device, it serves as a fulcrum of rotation.
There are few parts manufactured by cutting as a whole (for example, in the case of a structure in which a shaft is provided by cutting a bar as in the conventional case, the cutting for this is indispensable), and the structure is simple. Therefore, it is not necessary to perform the cutting work for providing the shaft portion as in the conventional case, and the manufacturing is facilitated. Therefore, the cost can be significantly reduced as compared with the conventional case. Furthermore, since the U-shaped tip of the lever portion is the center of rotation (fulcrum), it is easy to manufacture with high precision, and reliable and stable startability can be secured.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 5 shows an airbag 10 to which a trigger lever 50 of an airbag starting device according to a first embodiment of the present invention is applied. The arrow FR direction in the figure indicates the front side of the vehicle.

In this airbag 10, the base plate 12 is supported by a support means (not shown) substantially parallel to the hub 14A of the steering wheel 14 (both are shown by imaginary lines). A bag 16, a cover 18, and an inflator 20 are attached to the base plate 12.

The bag 16 is arranged in a folded state on the occupant side of the base plate 12 (upper side in FIG. 5). The edge of the bag 16 on the opening side is attached to a substantially central portion of the base plate 12 via a ring plate 22. The ring plate 22 is fastened to the base plate 12 with bolts (not shown), and the edge of the bag 16 on the opening side is pressed against the base plate 12.

The cover 18 is arranged on the occupant side of the base plate 12 and stores the bag 16 between the cover 18 and the base plate 12. A frame-shaped cored bar (not shown) is embedded in the periphery of the cover 18, and is attached to the base plate 12 by a riveting or the like via the cored bar. This cover 18
A thin portion 24 is formed at a portion facing the base plate 12 and is easily broken at this portion.

The inflator 20 has a cylindrical shape, and is arranged so as to be inserted into the bag 16 while penetrating substantially the center of the base plate 12. A flange 20A is formed on the outer circumference of the inflator 20, and is fixed to the surface of the base plate 12 on the side opposite to the occupant (lower side in FIG. 5) with a bolt (not shown).

As shown in FIG. 4, a gas generating substance 30 is enclosed in the inflator 20. Gas generating substance 3
0 is decomposed by combustion to release a large amount of gas, and the gas can inflate the bag 16. The gas generating substance 30 may be, for example, one containing sodium azide. An explosive charge (not shown) is provided around the gas generating substance 30 so that the gas generating substance 30 is burned when a detonator 72 described later is ignited.

Further, the inflator 20 has a built-in starter 34 for igniting the detonator 72 to burn the gas generating substance 30.

As shown in FIG. 2, two cylinders 40 supported by a block 38 are provided side by side in a cylindrical case 36 of the starting device 34 (only one cylinder 40 is shown in the drawing). ing).

The cylinder 40 is arranged in a cylinder fitting hole 42 formed through the case 36 and the block 38 with an O-ring 44 interposed. A spherical ball 48 as a mass body is housed in the cylinder 40 so as to be movable in the direction of arrow A in FIG. The ball 48 moves in the direction of arrow A in FIG. 2 due to inertial force when the vehicle suddenly decelerates.

A trigger lever 50 as a trigger member is arranged in front of the ball 48 in the vehicle.

As shown in detail in FIG. 1, the trigger lever 50
Is composed of a trigger portion 52 and a lever portion 54. The trigger portion 52 is formed of a plate material in a block shape, and the upper one end corner portion 56 is for locking an ignition pin 66 described later.

On the other hand, the lever portion 54 is formed into a substantially U-shape by bending a round bar material, and an intermediate portion thereof is press-fitted into a through hole formed in the trigger portion 52 and integrally fixed thereto. There is. The lever portion 54 may be fixed to the trigger portion 52 by caulking or the like. The U-shaped base end portion 58 of the lever portion 54 is arranged in contact with the ball 48 and holds the ball 48 at a predetermined position. Further, a pair of U-shaped tip portions 60 of the lever portion 54 projecting from the trigger portion 52 are formed in a spherical shape, and the tip portion 60 is formed with a support concave portion 64 formed in the block 62 as shown in FIG.
It's getting in. Accordingly, the lever portion 54 and the trigger portion 52 are configured such that the tip portion 60 serves as a fulcrum of rotation and the tip portion 60 can be rotated in the direction of arrow A in FIGS.

The trigger portion 5 of the trigger lever 50 having the above structure
An ignition pin 66 is locked at 2.

The ignition pin 66 is composed of a pin portion 66A and a locking portion 66B formed in the axially intermediate portion of the pin portion 66A. The tip of the pin portion 66A (the end portion on the vehicle rear side in FIG. 2) is formed in a needle-like shape.
On the other hand, the locking portion 66B is formed in a disk shape in which a large diameter portion and a small diameter portion located on the vehicle rear side of the large diameter portion are continuous. The locking portion 66B (large diameter portion) corresponds to the trigger portion 52 (upper one end corner portion 56) of the trigger lever 50, and the ignition pin 66 has the locking portion 66B (large diameter portion).
Is locked to the trigger portion 52 (upper one end corner portion 56).

On the other hand, one end of a compression coil spring 68 abuts on the vehicle front side of the locking portion 66B (large-diameter portion) of the ignition pin 66. The compression coil spring 68 is a block 62.
It is housed in a bottomed hole 70 formed in, and by this, the ignition pin 66 is always urged toward the vehicle rear side.
The trigger lever 50 (trigger portion 52 and lever portion 54) rotates about the tip portion 60 as a fulcrum, and the engagement between the locking portion 66B of the ignition pin 66 and the trigger portion 52 (upper one end corner portion 56) is released. In this case, the urging force of the compression coil spring 68 moves the ignition pin 66 toward the vehicle rear side in FIG.
It is supposed to collide with 2.

The detonator 72 is designed to be exploded by collision with the ignition pin 66 and to ignite a transfer charge (not shown).

Next, the operation of the first embodiment will be described. In a normal state of the vehicle, in the trigger lever 50, the trigger portion 52 is urged to the vehicle front side via the compression coil spring 68, whereby the ball 48 is urged to the vehicle rear side by the lever portion 54. The cylinder 40 is accommodated in a predetermined position.

The ignition pin 66, which is biased toward the rear side of the vehicle by the compression coil spring 68, has its locking portion 66B.
The (large-diameter portion) is locked to the trigger portion 52 (upper one end corner portion 56) of the trigger lever 50.

When the vehicle suddenly decelerates, the ball 48 housed at a predetermined position in the cylinder 40 inertially moves in the direction of arrow A in FIG.
Press.

Therefore, the trigger portion 52 rotates together with the lever portion 54 with the tip portion 60 as a fulcrum, and the trigger portion 52 is rotated.
The engagement between the (upper one end corner portion 56) and the locking portion 66B of the ignition pin 66 is released. Therefore, the compression coil spring 68
By the urging force of the ignition pin 66, the ignition pin 66 moves in the direction opposite to the arrow A in FIG. 2, and the pin portion 66A collides with the detonator 72. Detonator 7
2 is ignited by the collision with the ignition pin 66 (pin portion 66A) and explosive charge not shown explodes, whereby the gas generating substance 30 is burned and the bag 16 is inflated.

Here, the trigger lever 50 of the starting device 34
Then, the trigger portion 52 is formed in a plate shape, and the lever portion 54 simply fixed to the trigger portion 52 is bent and formed in a U shape. Further, the U-shaped tip portion 60 of the lever portion 54 is formed in the block 62 ( Since it comes into contact with the support concave portion 64) and serves as a fulcrum of rotation, the number of parts manufactured by cutting is small as a whole, and the structure is simple. Therefore, for example, in the case of a structure in which a shaft is provided by cutting a rod as in the conventional case, the cutting process for this is indispensable, but in the trigger lever 50, the conventional shaft part is provided. No need for cutting process and easy production. Therefore, the cost can be significantly reduced as compared with the conventional case. Furthermore, since the U-shaped tip portion 60 of the lever portion 54 is used as the center of rotation (fulcrum), it is easy to manufacture with high precision, and reliable and stable startability can be secured.

Next, another embodiment of the present invention will be described. The parts that are basically the same as those in the first embodiment have the first
The same reference numerals as in the embodiment are given and the description thereof is omitted.

FIG. 6 shows a trigger lever 8 according to the second embodiment.
0 is shown. The trigger lever 80 is composed of a trigger portion 82 and a lever portion 84. The trigger portion 82 is formed of a plate material, and the center portion of the upper end is cut off at an acute angle to form a corner portion 86 for locking the ignition pin 66.

On the other hand, the lever portion 84 is formed in a substantially U-shape by bending a round bar as in the first embodiment, and as shown in FIG. 7, both ends of the trigger portion 82 in the longitudinal direction. It is fixed integrally by folding back and crimping. The U-shaped base end portion 88 of the lever portion 84 is arranged in contact with the ball 48 to hold the ball 48 at a predetermined position. The pair of U-shaped tip portions 90 of the lever portion 84 are formed in an arc shape in a side view (in other words, along the same direction as the moving direction of the ball 48) as shown in FIG. The tip 90 is inserted into the support recess 64 formed in the block 62. This allows
The lever portion 84 and the trigger portion 82 are configured such that the tip end portion 90 serves as a fulcrum of rotation and the tip end portion 90 is rotatable about the tip end portion 90 in the arrow A direction in FIG.

Also in the trigger lever 80 according to the second embodiment, the trigger portion 82 is formed in a plate shape, and the lever portion 84 simply fixed to the trigger portion 82 is formed by bending in a U shape. Since the tip portion 90 of the lever portion 84 abuts on the block 62 (supporting concave portion 64) and serves as a fulcrum of rotation, the entire portion manufactured by cutting is small and the structure is simple. Therefore, it is not necessary to perform the cutting work for providing the shaft portion as in the conventional case, and the manufacturing is facilitated. Therefore, the cost can be significantly reduced as compared with the conventional case. Furthermore, the tip portion 9 of the lever portion 84
Since 0 is the center of rotation (fulcrum), it is easy to manufacture with high precision, and reliable and stable startability can be secured.

In each of the above embodiments, the tip portion 60 of the lever portion 54 of the trigger lever 50 is formed in a spherical shape, and the tip portion 90 of the lever portion 84 of the trigger lever 80 is arcuate in side view. Although it is configured to be
The lever portion 54 (tip portion 60) and the lever portion 84
The tip shape of the (tip portion 90) is not limited to such a shape,
Other shapes may be used as long as they can rotatably support the trigger lever 50 and the trigger lever 80.

For example, the tip portion 96 may be formed in a conical shape like the lever portion 94 shown in FIG. 9, or the tip portion 102 may be formed in a wedge shape like the lever portion 100 shown in FIG. Even in these cases, since the tip of each lever is used as the pivot of rotation as shown in FIG. 11, there are few parts to be manufactured by cutting, the structure is simple and the manufacture is easy, and the cost is significantly reduced. It is possible to reduce
A reliable and stable startability can be secured. Furthermore, FIG.
2 and the tip portion 108 like the lever portion 106 shown in FIG.
14 may be formed by bending toward the sides closer to each other.
Like the lever portion 112 shown in FIG. 1, the tip portions 114 may be formed by bending toward the sides separated from each other. Further, like the lever portion 118 shown in FIGS. 15 and 16, the tip portion 120 may be formed by bending in the same direction as the moving direction of the ball 48. Even in these cases, since the bent end of each lever is used as the fulcrum of rotation, there is no part to be manufactured by cutting, the structure is simple and the manufacturing is easy, and the cost is greatly reduced. Can be planned.

[0041]

As described above, the trigger member of the airbag start-up device according to the present invention can be manufactured easily and with high accuracy while ensuring reliable and stable startability, and the cost can be greatly reduced. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a perspective view of a trigger lever according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a schematic structure of a starting device to which a trigger lever according to a first embodiment of the present invention is applied.

FIG. 3 is an enlarged sectional view of a main part of FIG. 2 showing a tip shape of a trigger lever according to a first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of the inflator showing a mounting state of the starting device.

FIG. 5 is a cross-sectional view showing a schematic structure of an airbag to which a starting device is applied.

FIG. 6 is a perspective view of a trigger lever according to a second embodiment of the present invention.

FIG. 7 is a transverse sectional view of a trigger lever according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view corresponding to FIG. 3, showing a tip shape of a trigger lever according to a second embodiment of the present invention.

FIG. 9 is a perspective view showing another example of the lever portion of the trigger lever.

FIG. 10 is a perspective view showing another example of the lever portion of the trigger lever.

11 is a cross-sectional view corresponding to FIG. 3 showing an arrangement state of the lever portion shown in FIGS. 9 and 10. FIG.

FIG. 12 is a perspective view showing another example of the lever portion of the trigger lever.

13 is a perspective view showing an arrangement state of the lever portion shown in FIG.

FIG. 14 is a perspective view showing another example of the lever portion of the trigger lever.

FIG. 15 is a perspective view showing another example of the lever portion of the trigger lever.

16 is a view showing the arrangement state of the lever portion shown in FIG.
It is sectional drawing corresponding to.

FIG. 17 is a perspective view showing a conventional trigger lever.

FIG. 18 is a vertical cross-sectional view of a starting device to which a conventional trigger lever is applied.

[Explanation of symbols]

 34 Starter device 48 Ball (mass body) 50 Trigger lever (trigger member) 52 Trigger part 54 Lever part 56 Upper end corner part 60 Tip part 66 Ignition pin 72 Detonator 80 Trigger lever (trigger member) 82 Trigger part 84 Lever part

Claims (1)

[Claims] 1. A starter device for an airbag, comprising a mass body for detecting sudden vehicle deceleration by inertial movement, and an ignition pin which acts on a detonator to expand the bag and always urged in a direction to collide with the detonator. A trigger member that is formed in a plate shape and that engages with the ignition pin to prevent movement of the ignition pin and rotates to release the movement inhibition of the ignition pin; Formed in a shape and having an intermediate portion fixed to the trigger portion, a U-shaped base end portion is engaged with the mass body to hold the mass body in a predetermined position, and a U-shaped tip end portion is a main body of the activation device. A trigger member for an airbag starting device, comprising: a lever portion that is brought into contact with the vehicle body and serves as a fulcrum of rotation and that is rotated together with the trigger portion by inertial movement of the mass body when the vehicle is suddenly decelerated.