JPH084365Y2 - Starter for air bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an air bag starting device for inflating a bag mounted on a vehicle.

[Prior Art] A so-called mechanical type that includes an inertial mass body (ball) is known as an air bag starter that expands the bag when the vehicle suddenly decelerates to intervene between the steering wheel and an occupant. (For example, JP-A-60-248454, JP-A-60-248454)
60-248455, JP-A-60-248456, JP-A-60-248457
Issue).

FIG. 6 is a perspective view showing essential parts of an air bag starting device of this type. In this figure, two sets (a pair) of essential parts are shown.

A ball 90 is housed in a cylinder 92 and one end of a drive shaft 94 abuts on the starting device. A trigger portion 96 is formed at an intermediate portion of the drive shaft 94, and engages with the ignition pin 98 to hold it. When the vehicle suddenly decelerates, etc., the ball 90 moves to rotate the drive shaft 94, which releases the locking of the ignition pin 98 by the trigger portion 96, and the ignition pin 98 is detonated (not shown).
The bag is expanded by igniting.

In addition, a safety device is incorporated in the starting device in order to prevent an accidental malfunction or the like when it is assembled into a vehicle, for example. As shown in FIG. 6, the safety device includes a lock lever 100 capable of abutting against the drive shaft 94 to prevent the drive shaft 94 from moving, and a lock shaft 10 engaging with the drive shaft 100 and separating from the drive shaft 94.
It is composed of two.

One end of the lock lever 100 is a contact portion 104,
It is in contact with the drive shaft 94. Further, a coil-shaped spring portion 106 is formed at the other end of the lock lever 100, and urges the contact portion 104 in the direction of coming into contact with the drive shaft 94. On the other hand, the end of the lock shaft 102 is formed in a conical shape to form a release surface 108, which corresponds between the drive shaft 94 and the lock shaft 102.

In such a starting device, the contact portion 104 of the lock lever 100 comes into contact with the drive shaft 94 to prevent the drive shaft 94 from moving when the safety device is in operation (for example, when the starting device is assembled to the vehicle). Therefore, the accidental malfunction of the starting device is prevented. When releasing the safety device after assembling the starter, the release shaft (not shown) pushes the lock shaft 102 in the direction of arrow D in FIG. 6, and the release surface 108 enters between the drive shaft 94 and the lock shaft 102. . Therefore, the lock lever 100 rotates against the urging force of the spring portion 106, and the contact portion 104 separates from the drive shaft 94 (in the direction of arrow E), which allows the drive shaft 94 to move, and the starter device. Is operable, that is, the safety device is released.

[Problems to be Solved by the Invention] By the way, in such an air bag starting device equipped with such a conventional safety device, in order to ensure a safe operating state of the safety device (that is, a starting device inoperable state), It is desirable to increase the biasing force of the spring portion 106 so that the contact portion 104 surely contacts the drive shaft 94 and is not easily separated.

However, in this case, if the urging force of the spring portion 106 of the lock lever 100 is simply increased, the contact force between the lock lever 100 and the release surface 108 of the lock shaft 102 is increased, and both are partially biased and worn, resulting in a frictional resistance. To increase.
Therefore, the lock shaft 102 needs to be hardened, which causes a cost increase.

In consideration of the above facts, the present invention is capable of smoothly performing an operation for preventing an inadvertent movement of the drive shaft and preventing a malfunction and an operation for enabling the movement of the drive shaft, which is reliable. The purpose is to obtain an air bag starting device with improved performance.

[Means for Solving the Problems] An air bag starting device according to the present invention includes a mass body that detects a sudden vehicle deceleration by inertial movement, an ignition pin that acts on a detonator to expand the bag, and abuts on the mass body. Drive that holds the mass body at a predetermined position and engages with the ignition pin to prevent movement of the ignition pin, and when the vehicle suddenly decelerates, rotates due to inertial movement of the mass body to release movement inhibition of the ignition pin. Moveable between a shaft and a first state in which the drive shaft is engaged with the drive shaft to prevent the drive shaft from rotating due to inertial movement of the mass body; and a second state in which the drive shaft is rotatable. The arranged lock bar, the lock shaft for engaging the lock bar by moving and forcibly separating the lock bar from the drive shaft, and the lock bar An actuating device for an air bag, comprising: a biasing member that biases the lock shaft in a direction in which the lock shaft is engaged with the drive shaft, wherein an operating portion protruding in a direction orthogonal to a moving direction of the lock shaft is formed in the lock shaft. Along with
A first guide portion that is capable of engaging the operating portion when the lock shaft is moved in one direction to press the lock bar to the first state, and is operated when the lock shaft is moved in a direction opposite to the one direction. A second guide part which is engaged with the lock bar to press the lock bar to the second state is formed on the lock bar together, and is connected to the lock shaft via the operating part and the first and second guide parts. It is characterized in that the lock bar is interlocked.

[Operation] In the air bag starting device having the above-described configuration, the operating portion formed on the lock shaft engages with the first guide portion or the second guide portion formed on the lock bar, and the lock bar is forced along with the movement of the lock shaft. Are linked to each other. That is, when the lock shaft held in a state of being separated from the drive shaft is reengaged with the drive shaft (when the safety device once released is reactivated, that is, when the activation device is inoperable again). However, the lock bar separated from the drive shaft smoothly returns to the lock shaft which is moved by the urging force of the urging member, and engages with the drive shaft again.
In other words, the safety device is smoothly reactivated.

Therefore, the operation for enabling the movement of the drive shaft can be surely performed, and the operation for preventing the accidental movement of the drive shaft to prevent the malfunction can be smoothly performed. The property is improved.

[Embodiment] FIG. 5 shows an air bag 10 to which an air bag starting device according to an embodiment of the present invention is applied. In addition,
The arrow FR direction in the figure indicates the vehicle front direction.

As shown in this figure, in the air bag 10, the base plate 12 is supported by a support means (not shown) substantially parallel to the hub 14A (shown in phantom line) of the steering wheel 14 (shown in phantom line). The base plate 12 has a back
16, a cover 18 and an inflator 20 are attached.

The bag 16 is on the occupant side of the base plate 12 (upper side in FIG. 5).
It is placed in a folded state. The opening 16 of the bag 16 is attached to a substantially central portion of the base plate 12 via a ring plate 22. Ring plate 22
Is fastened to the base plate 12 with a bolt (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. A thin portion 24 is formed at a portion of the cover 18 facing the base plate 12, and is easily broken at this portion.

The inflator 20 has a cylindrical shape, and is arranged in a state of being inserted into the bag 16 while penetrating substantially the central portion of the base plate 12. A flange 20A is formed on the outer periphery 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, the inflator 20 has a gas generating substance.
30 is enclosed. The gas generating substance 30 is decomposed by combustion to release a large amount of gas, and this gas can expand the bag 16. The gas generating substance 30 includes, for example, a substance containing sodium azide. An explosive charge and a detonator 60 (shown in FIG. 3), which are not shown, are provided around the gas generating substance 30 so that the gas generating substance 30 is burned when the detonator 60 is ignited. Further, the inflator 20 has a built-in starter 34 for igniting the detonator and burning the gas generating substance 30.

Here, FIG. 1 is a schematic perspective view showing the configuration of main parts of the starting device 34, and FIGS. 2 and 3 are sectional views of the starting device 34.

The starting device 34 is provided with two cylinders 40 side by side, which are supported by a cylindrical block 38. This cylinder 40
A spherical ball 42 as a mass body is housed therein so as to be movable in the direction of arrow A in FIGS. 2 and 3. The ball 42 moves in the direction of arrow A in FIGS. 2 and 3 due to inertial force when the vehicle is suddenly decelerated.

As shown in FIG. 3, on the vehicle front side of the ball 42, one end of the drive shaft 44 in the axial direction is arranged in contact with the ball 42. A trigger portion 46 is integrally fixed to the drive shaft 44 at a substantially intermediate portion in the axial direction of the drive shaft 44.

The trigger portion 46 is a substantially square trapezoidal block material, and support pins 48 are projectingly formed at both ends in the longitudinal direction thereof, and the support pins 48 are provided with support holes (not shown) formed in the block 38.
It is configured to be fitted inside to rotatably support the trigger portion 46 and the drive shaft 44.

On the other hand, the bias pin 50 is in contact with the other end of the drive shaft 44 in the axial direction.
A compression coil spring 52 is arranged between the block 38 and the block 38. For this reason, the drive shaft 44 is always urged in the forward direction of the vehicle via the bias pin 50 at the other end (the state shown in FIG. 3).
Under normal conditions, one end of the drive shaft 44 is pressed in the rearward direction of the vehicle to be housed in a predetermined position inside the cylinder 40.

Trigger part 46 integrally fixed to drive shaft 44
An ignition pin 54 is locked at the end of the vehicle on the front side. The ignition pin 54 is composed of a pin portion 54A and a locking portion 54B formed at an axially intermediate portion of the pin portion 54A. The tip of the pin portion 54A (the end portion on the vehicle rear side in FIG. 3) is formed in a needle-like shape. On the other hand, the locking portion 54B is formed in a disk shape, and the locking portion 54B is engaged with the vehicle front side end of the trigger portion 46 of the drive shaft 44 so that the ignition pin 54 is held. ing.

One end of the compression coil spring 56 is in contact with the vehicle front surface of the locking portion 54B. Compression coil spring 56
Are housed in a housing hole 58 formed in the block 39, whereby the ignition pin 54 is always biased in the vehicle rearward direction. The trigger portion 46 of the drive shaft 44 pivots around the support pin 48 to lock the trigger portion 46 and the ignition pin 54.
When the engagement with 54B is released, the urging force of the compression coil spring 56 causes the ignition pin 54 to move in the direction of arrow C (vehicle rearward direction) in FIG. .

The detonator 60 is exploded by collision with the ignition pin 54 and can ignite a transfer charge (not shown).

As shown in detail in FIGS. 1 and 2, a lock bar 62 is disposed on the side of the drive shaft 44. The lock bar 62 is a relatively long plate member, which is slidably fitted in a guide groove 64 formed in the block 39, and the tip end thereof can come into contact with the drive shaft 44 opposite to the ball 42. There is. Therefore, when the tip end of the lock bar 62 is in contact with the drive shaft 44 (first state), the ball
The rotation of the drive shaft 44 due to the inertial movement of the drive shaft 42 is prevented, and when the tip end of the lock bar 62 is separated from the drive shaft 44 (second state), the drive shaft 44 can be rotated.

At the other end of the lock bar 62 (the end opposite to the drive shaft) 44, guide holes 66 are formed as first and second guide parts. The guide hole 66 has a rectangular shape, and its longitudinal axis is in the moving direction of the ball 42 (drive shaft 44
Is formed so as to be inclined with respect to a direction orthogonal to the rotation axis line.

A lock shaft 68 is arranged on the side of the lock bar 62. The lock shaft 68 has a columnar shape, and its axis is arranged along the moving direction of the ball 42 (direction orthogonal to the rotation axis of the drive shaft 44), and the lock shaft 68 is provided in the bottomed storage hole 70 formed in the block 38. It is stored so that it can be moved.
At the end of the lock shaft 68 on the block 38 side, a pair of guide pins 72 are formed so as to project in a direction orthogonal to the axis, and the guide pins 72 are fitted into a groove 74 formed in the side wall of the storage hole 70 to allow the lock shaft 68 to fit. It prevents rotation around the axis and guides movement along the axis.

On the other hand, a pair of actuating pins 76 as actuating portions are formed in the axially intermediate portion of the lock shaft 68 so as to project in a direction orthogonal to the axial line of the lock shaft 68, similarly to the guide pins 72. The operating pin 76 is provided in the guide hole 66 of the lock bar 62 described above.
It goes inside and thereby connects the lock bar 62 and the lock shaft 68. Therefore, when the lock shaft 68 moves along the storage hole 70, the guide hole formed such that the longitudinal axis is inclined with respect to the moving direction of the ball 42, that is, the direction orthogonal to the moving direction of the lock shaft 68.
The actuating pin 76 presses the inner peripheral wall of 66, thereby interlocking the lock bar 62 with the lock shaft 68 and forcibly moving it toward or away from the drive shaft 44.

A compression coil spring 78 as a biasing member is arranged between the lock shaft 68 and the storage hole 70, and the direction in which the tip of the lock bar 62 engages with the drive shaft 44, that is, the lock shaft 68 is stored in the storage hole 70. The lock shaft 68 is constantly pressed in the direction in which it exits. Therefore, the lock bar 62 usually has a drive shaft at the tip.
It is in a state of abutting against 44 and preventing its rotation.

A hole 80 is formed in the block 39 on the side opposite to the housing hole 70, and a release pin 82 is inserted therein.
The release pin 82 corresponds to the lock shaft 68, and pushes the lock shaft 68 against the urging force of the compression coil spring 78 to move the lock shaft 68 in the direction of the storage hole 70 (direction of arrow B in FIG. 2).

 Next, the operation of this embodiment will be described.

In the air bag starting device 34 having the above-described configuration, the safety device operating state (starting device inoperable state) is set when the air bag starting device 34 is mounted on a vehicle. That is, in this state, one end of the drive shaft 44 is biased toward the front of the vehicle via the bias pin 50, whereby the ball 42
Is accommodated in a predetermined position in the cylinder 40 by being urged in the vehicle rearward direction by the upper end of the drive shaft 44.
Further, the ignition pin 54 urged in the vehicle rearward direction by the compression coil spring 56 has its engaging portion 54B retained by the trigger portion 46 of the drive shaft 44 (state shown in FIG. 3).

Further, the lock shaft 68 is pressed by the urging force of the compression coil spring 78 in the direction of exiting from the storage hole 70 (vehicle front side), and the operating pin 76 is positioned at one end portion (upper end portion in FIG. 2) of the guide hole 66. In this state, the lock bar 62 is in a state in which the tip end thereof abuts the drive shaft 44 to prevent its rotation (the state shown in FIG. 2).

Therefore, even when the starter 34 is assembled to the vehicle, the lock bar 62 abuts the drive shaft 44 to prevent the drive shaft 44 from moving, so that the ball 42
Does not move within the Trinder 40, so that careless malfunction of the activation device 34 and the like can be prevented.

When releasing the safety device after assembling the activation device 34,
Insert release pin 82 through hole 80 to lock
68 is pushed in the direction of arrow B in FIG. 2 against the urging force of the compression coil spring 78, and the lock shaft 68 moves along the storage hole 70. Therefore, the actuating pin 76 sequentially presses the inner peripheral wall of the guide hole 66 formed so that the longitudinal axis is inclined with respect to the direction orthogonal to the movement direction of the lock shaft 68, whereby the lock bar 62 is interlocked with the lock shaft 68. Then, it is forcibly moved and separated from the drive shaft 44. As a result, the drive shaft 44 can be moved, and the activation device 34 is in an operable state, that is, the safety device is released.

Here, for example, when the lock bar 62 held in a state of being separated from the drive shaft 44 is brought into contact with the drive shaft 44 again in order to remove the air bag 10 from the steering wheel 14, etc. The release pin 82 is pulled out from the hole 80 when actuating, that is, when the actuating device 34 is disabled again.

When the release pin 82 is pulled out from the hole 80, the lock shaft 68 moves in the vehicle front direction (the arrow FR direction in FIG. 2) by the urging force of the compression coil spring 78. Therefore, the operating pin 76 formed in the lock shaft 68 engages with the inner peripheral wall of the guide hole 66 formed in the lock bar 62, the lock bar 62 is forcibly interlocked with the movement of the lock shaft 68, and again. The drive shaft 44 is engaged and the rotation thereof is blocked. That is, when the lock bar 62 held in a state of being separated from the drive shaft 44 is re-engaged with the drive shaft 44 (when the once released safety device is operated again, that is, the activation device 34).
Even if the bet is in the inoperable state again), the lock bar 62 separated from the drive shaft 44 smoothly returns in conjunction with the lock shaft 68 moving by the biasing force of the compression coil spring 78 (biasing member). Then, the drive shaft 44 is engaged again. In other words, the safety device is smoothly reactivated.

Therefore, the operation for enabling the movement of the drive shaft 44 (release of the safety device) can be surely performed, and the operation for preventing the accidental movement of the drive shaft 44 to prevent the malfunction (safety) The operation of the device) can be performed smoothly, and the reliability is improved.

After the starter 34 is assembled and the safety device is released, when the vehicle suddenly decelerates, the ball 42 accommodated at a predetermined position in the cylinder 40 inertially moves in the direction of arrow A in FIG. Press the shaft 44.

Therefore, the trigger portion 46 of the drive shaft 44 rotates around the support pin 48, and the engagement portion between the trigger portion 46 and the ignition pin 54.
The engagement with 54B is released. Therefore, the urging force of the compression coil spring 56 causes the ignition pin 54 to move toward the arrow C in FIG.
And the pin portion 54A collides with the detonator 60. Detonator 60
Is ignited by the collision with the ignition pin 54 (pin portion 54A), the explosive charge not shown explodes, the gas generating substance 30 is burned, and the bag 16 expands.

As described above, in the activation device 34, the operation pin 76 and the guide hole 66 are provided.
Since the lock bar 62 is moved in conjunction with the lock shaft 68 via the shaft, the operation for engaging the drive shaft 44 becomes smooth, and the safety device is smoothly re-operated.

[Effects of the Invention] As described above, the air bag starting device according to the present invention is designed to prevent an inadvertent movement of the drive shaft and prevent an erroneous operation, and to enable the drive shaft to move. The operation can be performed smoothly, and the reliability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing the configuration of main parts of the starting device, FIG. 2 is a sectional view of the starting device showing an operating pin and a lock bar, and FIG. 3 is a sectional view of the starting device showing a drive shaft and an ignition pin. FIG. 4 is a partial cross-sectional view showing the mounting state of the starting device, FIG. 5 is a cross-sectional view showing the schematic structure of an air bag to which the starting device is applied, and FIG. 6 is a configuration of the main parts of a conventional starting device. It is a perspective view which shows roughly. 34 …… Starter, 42 …… Ball, 44 …… Drive shaft, 54 …… Ignition pin, 62 …… Lock bar, 66 …… Guide hole (first and second guide part), 68 …… Lock shaft, 76
...... Operating pin (operating part), 78 ... Compression coil spring.

Claims (1)

[Scope of utility model registration request] 1. A mass body for detecting sudden vehicle deceleration by inertial movement, and an ignition pin for acting on a detonator to expand a bag.
The mass body is held in contact with the mass body at a predetermined position and is engaged with the ignition pin to prevent movement of the ignition pin. A drive shaft for releasing movement inhibition, a first state for engaging with the drive shaft for preventing rotation of the drive shaft due to inertial movement of the mass body, and a second state for enabling rotation of the drive shaft. A lock bar movably disposed between the lock bar and the lock bar for moving the lock bar to forcibly separate the lock bar from the drive shaft, and a direction in which the lock bar engages with the drive shaft. An air bag starting device comprising: a biasing member for biasing the lock shaft, which is orthogonal to a moving direction of the lock shaft. And a first guide portion capable of pressing the lock bar into the first state by engaging the operation portion when the lock shaft is moved in one direction, while forming an operation portion projecting in a direction in the lock shaft. When the lock shaft is moved in the opposite direction to the one direction, the operating portion is engaged with the lock bar to form a second guide portion capable of pressing the lock bar into the second state. An activation device for an air bag, wherein the lock bar is interlocked with the lock shaft via first and second guide portions.