JPH05458Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air bag activation device that is attached to a vehicle and inflates the bag.

[Prior Art] An air bag, for example, an air bag attached to a steering wheel, is provided with an activation device that inflates the air bag and interposes it between the steering wheel and the occupant when the vehicle suddenly decelerates. It's summery.

In a conventional starter device 80 of this type, as shown in FIG. 6, a spherical ball 86 is housed in a cylinder 84, and one end of a drive shaft 88 comes into contact with the ball 86. On the other hand, the other end of the drive shaft 88 is pressed by a bias pin 83 equipped with a compression coil spring 82, which causes the drive shaft 88 to push the ball 86 into the cylinder 84.
It is held in place within the device.

The bias pin 83 has a spherical surface that contacts the drive shaft 88, thereby avoiding contact at the edges and achieving a smooth contact state.

When the vehicle suddenly decelerates, the ball 86 housed in a predetermined position within the cylinder 84 moves in the direction of arrow A, which is the forward direction of the vehicle, by inertia force against the biasing force of the compression coil spring 82 and swings the drive shaft 88. Then, the trigger shaft 90 fixed to the drive shaft 88 moves clockwise, and the engagement between the trigger shaft 90 and the ignition pin 92 is released.
This causes the ignition pin 92 to actuate the detonator 94 and inflate the bag (not shown).

By the way, in order to inflate the bag at a predetermined rapid deceleration of the vehicle, the pressing force of the drive shaft 88 by the bias pin 83, that is, the compression coil spring 82
The biasing force must be kept constant.

However, since the contact surface of the bias pin 83 with the drive shaft 88 is a spherical surface, even if there is a slight assembly error of the drive shaft 88, the bias pin 83 will not fit the drive shaft 88.
There were cases where the pressing position for 8 was shifted. Therefore, the overall length of the compression coil spring 82 that biases the bias pin 83 when assembled is not constant, and the biasing force of the compression coil spring 82 is not stable.

[Problem to be solved by the invention] Taking the above facts into consideration, the present invention provides an airbag activation device that constantly keeps the pressing force of the bias pin on the drive shaft that constitutes the airbag activation device constant, so that the sensing sensitivity does not fluctuate. The purpose is to provide equipment.

[Means for Solving the Problems] The air bag starting device according to the present invention includes a ball that detects sudden deceleration of a vehicle by inertial movement, a ball that engages with the ball to hold the ball in a predetermined position, and a device that prevents the ball from moving when the vehicle suddenly decelerates. A drive shaft that rotates due to inertial movement, an ignition pin that acts on the detonator and expands the bag, and an ignition pin that is fixed to the drive shaft and engages with the ignition pin to prevent the ignition pin from moving, and a drive that acts when the vehicle suddenly decelerates. a trigger shaft that rotates with the shaft to release the blocking of the ignition pin; a bias pin that presses the drive shaft in the opposite direction to the direction in which the trigger shaft releases the blocking of the ignition pin when the vehicle suddenly decelerates;
An airbag starting device comprising: a pressing portion of the bias pin that presses the drive shaft, which is wide in a direction perpendicular to the axis of the drive shaft and convex around the axis perpendicular to the axis of the drive shaft; It is characterized by its curved shape.

[Function] In the air bag starting device configured as described above, the bias pin is formed wide in the direction orthogonal to the axis of the drive shaft, that is, with a margin, so that even if the drive shaft is misaligned, Also, the pressing position by the bias pin remains constant. Therefore, the dimensions of the assembly portion of the biasing means for biasing the bias pin (for example, the overall length of the compression coil spring when assembled) are constant.

Therefore, the pressing force of the bias pin on the drive shaft can be kept constant, and the bag can always be properly inflated without fluctuation in sensitivity.

[Embodiment] Figs. 2 to 4 show an airbag 10 to which the present invention is applied. In addition, the arrow in the figure
The FR direction indicates the forward direction of the vehicle.

As shown in FIG. 4, in the airbag 10, a base plate 12 is supported substantially parallel to a hub 14A (indicated by an imaginary line) of a steering wheel 14 (indicated by an imaginary line) by support means (not shown). 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 passenger side of the base plate 12 (upper side in FIG. 4). The opening edge of the bag 16 is attached to the approximate center 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 opening side edge of the bag 16 is attached to the base plate 1.
I'm pushing it to 2.

The cover 18 is disposed on the passenger side of the base plate 12 (upper side in FIG. 4) and stores the bag 16 between it and the base plate 12. This cover 18
A frame-shaped core bar (not shown) is embedded around the base plate 12, and is attached to the base plate 12 with rivets or the like via the core bar. A thin wall portion 24 is formed at a portion of the cover 18 that faces the base plate 12, and is designed to be easily broken at this portion.

The inflator 20 has a cylindrical shape, and is inserted into the bag 16 through a substantially 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 passenger (lower side in FIG. 4) with bolts (not shown).

As shown in FIG. 3, this inflator 20 is filled with a gas generating substance 30. The gas generating material 30 is decomposed by combustion and releases a large amount of gas, which can inflate the bag 16. The gas generating substance 30 includes, for example, one containing sodium azide. A detonator and a booster charge (not shown) are provided around the gas generating substance 30, so that the gas generating substance 30 is combusted when the detonator ignites.

Further, the inflator 20 has a built-in starting device 34 for igniting a detonator (not shown) and burning the gas generating substance 30.

As shown in FIG. 2, within the cylindrical case 36 of the starting device 34 there are two
The cylinders 40 are arranged side by side. (Only one cylinder 40 is shown in the drawing). That is,
The cylinder 40 is screwed into a cylinder screw hole 42 bored through the case 36 and the block 38, and is movable in the direction of arrow A.

A screw 4 is provided on the outer periphery of the cylinder 40 in the longitudinal direction.
4 is carved, and a groove 46 is formed on the vehicle rear side of the cylinder 40. The tip of a driver 52 (shown in phantom lines) or the like can be fitted into this groove 46. Furthermore, a female thread 50 is formed on the inner circumferential surface of the cylinder screw hole 42 .

A spherical ball 48 is accommodated within the cylinder 40 so as to be movable in the direction of arrow A in FIG. The ball 48 is adapted to move in the direction of arrow A in FIG. 2 due to inertia when the vehicle suddenly decelerates.

A drive shaft 54 is disposed in the forward direction of the vehicle with the upper end of the drive shaft 54 in contact with the ball 48 . The drive shaft 54 passes through a hole formed in the diametrical direction of the trigger shaft 56 and is fixed integrally with the trigger shaft 56.

On the other hand, a bias pin 60 is in contact with the lower end of the drive shaft 54, and a bias spring 58 is disposed between the bias pin 60 and the block 38. Therefore, the drive shaft 54 has its lower end connected to the bias pin 6.
0 is always biased toward the front of the vehicle,
As a result, the ball 48 is normally urged toward the rear of the vehicle by the upper end of the drive shaft 54 and housed in a predetermined position within the cylinder 40 .

As shown in FIG. 1, the bias pin 60 has a substantially cylindrical shape, and a similarly cylindrical convex portion 61 with a slightly smaller diameter is formed protruding from the rear end, and a compression coil spring 5 is formed on the bias pin 60.
8. It is designed for inserting the tip.

Further, a pair of guide portions 63 are formed on the sides of the bias pin 60 so as to protrude along the axis thereof, and serve as guides when the bias pin 60 slides.

On the other hand, the tip of the bias pin 60 (that is, the end on the side that presses the drive shaft 54) has a wide width in a direction perpendicular to the axis of the drive shaft 54, and a pin that is perpendicular to the axis of the drive shaft 54. The pressing portion 65 is curved convexly around the axis. The widthwise dimension of this pressing portion 65 (the dimension in the direction orthogonal to the axis of the drive shaft 54) is formed to be sufficiently larger than the outer diameter dimension of the drive shaft 54. Therefore, even if the assembly position of the drive shaft 54 is shifted (that is, the drive shaft 54 is assembled with a shift in the direction perpendicular to the plane of the second drawing),
Drive shaft 5 due to this bias pin 60
4, the pressing position in the left-right direction on the paper surface of the second drawing is constant.

A notch 62 is formed in a portion in the longitudinal direction of the trigger shaft 56 that is integrally fixed to the drive shaft 54. A rear end of an ignition pin 66 that is biased toward the rear of the vehicle by a compression coil spring 64 is locked in the notch 62 . This ignition pin 6
6 is a notch 6 formed by the swinging of the trigger shaft 56.
When the engagement with the detonator 2 is released, the detonator 68 is guided by support means (not shown) to move toward the rear of the vehicle in FIG. 2 and collide with the detonator 68.

The detonator 68 is detonated by collision with the ignition pin 66, and can ignite a booster charge (not shown).

Next, the operation of this embodiment will be explained.

Ignition pin 66 and notch 6 of trigger shaft 56
2 and 2 is adjusted when the ball 48 is assembled.

That is, first, the cylinder 40 containing the ball 48 is screwed into the cylinder screw hole 42 using the driver 52, and the cylinder 40 is moved in the direction of arrow A. Then, the ball 48 and the drive shaft 54 come into contact with each other, and the drive shaft 54 is then moved in the direction of arrow A by the ball 48, so that the trigger shaft 5, which is integral with the drive shaft 54,
6 rotates clockwise, the ignition pin 66 that was engaged with the notch 62 of the trigger shaft 56
is released.

When the trigger shaft 56 and ignition pin 66 are released, the movement of the cylinder 40 is stopped,
The driver 52 is now rotated in the opposite direction by a predetermined distance, and the cylinder 40 is returned in the direction opposite to the direction of arrow A until the ignition pin 66 and the trigger shaft 56 reach the designed dimensions.

In this case, the cylinder 40 may be rotated by the number of rotations corresponding to the design dimensions by converting the thread pitch of the external thread 44 formed in the cylinder 40.

Finally, when the trigger shaft 56 and the ignition pin 66 are locked, the adjustment is completed.

Furthermore, after this, the starting device 34 is connected to the inflator 2.
It should be installed within 0.

By the way, the adjustment of the sharpness between the ignition pin 66 and the notch 62 of the trigger shaft 56 is performed by adjusting the bias pin 60 to adjust the pitch between the drive shaft 5 and the trigger shaft 56.
4, the pressing position in the left and right direction of the paper of the second drawing is determined. cannot be adjusted only by rotating the cylinder 40.

For this reason, conventionally, as shown in FIG. 5A, the position at which the bias pin 83 presses the drive shaft 88 is not constant, and the distance between the bias pin 83 and the block 89 varies by the dimension t. Therefore, the total length of the bias spring 82 assembled during this time is not constant,
It was not possible to make the pressing force of the drive shaft 88 constant by the bias spring 82.

However, in this embodiment, the tip of the bias pin 60 (that is, the end on the side that presses the drive shaft 54) has the drive shaft 54
A pressing portion 65 is formed with a wide width in a direction perpendicular to the axis of the drive shaft 54 and convexly curved around an axis perpendicular to the axis of the drive shaft 54. Since the dimension in the direction perpendicular to the axis of the drive shaft 54 is formed to be sufficiently larger than the outer diameter dimension of the drive shaft 54, the assembly position of the drive shaft 54 is in the direction perpendicular to the paper surface of the second drawing. Even if the drive shaft 54 is assembled with a deviation, the bias pin 60 presses the drive shaft 54 at a constant position in the left-right direction in the plane of the second drawing, as shown in FIG. 5B.

Therefore, the dimension between the bias pin 60 and the block 38, ie, the total length of the bias spring 58 when assembled, becomes constant. Therefore, the biasing force of the bias spring 58 (bias pin 6
The pressing force of the drive shaft 54 caused by 0 can be kept constant, and the bag can be constantly inflated without any fluctuation in sensitivity.

[Effects of the invention] As explained above, the air bag starting device according to the present invention can maintain a constant assembly position of the bias pin constituting the air bag starting device, and thereby the bias pin can push the drive shaft. It has an excellent effect in that the pressure is always constant and the sensitivity does not fluctuate.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a bias pin arranged in the starting device according to the present invention, Fig. 2 is a vertical sectional view showing the schematic structure of the starting device, and Fig. 3 is a partial sectional view showing the installation state of the starting device. Figure 4 is a sectional view showing the schematic structure of the airbag to which the activation device is applied, and Figure 5A.
5B is a schematic diagram showing the assembled state of the bias pin arranged in the conventional starting device and the drive shaft, and FIG. 5B is a schematic diagram showing the assembled state of the bias pin arranged in the starting device according to the present invention and the drive shaft. FIG. 6 is a vertical sectional view showing a conventional example of a starting device. 16...bug, 34...starting device, 40...
Cylinder, 48... Ball, 54... Drive shaft, 56... Trigger shaft, 58... Bias spring, 60... Bias pin, 62...
...notch part, 65...pressing part, 66...ignition pin.

Claims (1)

[Scope of utility model registration request] A ball that detects sudden deceleration of a vehicle by inertial movement, a drive shaft that engages with the ball and holds it in a predetermined position and is rotated by the inertial movement of the ball when the vehicle suddenly decelerates, and a detonator that acts on the detonator to deform the detonator. a trigger shaft that is fixed to the drive shaft and engages with the ignition pin to prevent movement of the ignition pin, and rotates with the drive shaft to release the prevention of movement of the ignition pin when the vehicle suddenly decelerates; An air bag starting device comprising: a bias pin that presses a drive shaft in a direction opposite to the direction in which the trigger shaft releases the ignition pin from being blocked when the vehicle suddenly decelerates, the pressing unit that presses the drive shaft of the bias pin. 1. A starting device for an airbag, characterized in that the air bag is wide in a direction perpendicular to the axis of a drive shaft and curved convexly around an axis perpendicular to the axis of the drive shaft.