JPH0620136Y2 - Vehicle acceleration detection device - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] <Industrial field of application> The present invention provides a device for automatically tightening the slack of a seat belt, an airbag device, or the like, which is provided in front of an occupant in the event of a collision. The present invention relates to a vehicle acceleration detection device for giving an operation signal to an occupant protection device that minimizes movement.

<Prior Art> A seat belt device for restraining movement of an occupant is provided in a seat of an automobile in order to prevent the occupant from being thrown forward in a collision accident or the like. It is preferable that these seat belt devices do not restrain the normal driving operation and tension only when a deceleration of a predetermined value or more is applied.
In Japanese Patent No. 61069, there is proposed a preloader device that detects the impact at the time of collision, ignites propellant, and uses the energy at this time to tension the seat belt. Further, U.S. Pat. No. 4,148,503 discloses a device that incorporates an airbag that rapidly inflates in the event of a collision into a steering wheel to reduce the impact on an occupant.

On the other hand, as a collision detection device for operating these occupant protection devices, a weight and a trigger that engages with the weight are used, and the trigger is activated by using the operation of the weight due to inertial force. The type is often used (see US Pat. No. 4,580,810). Due to the peculiarities of the usage situation, it is difficult to perform a normal operation test on these collision detection devices, so they reliably operate at the set deceleration, and do not malfunction during normal operation. Thus, extremely high operational reliability is required.

<Problems to be solved by the invention> As one method for improving the operation reliability,
For example, it is conceivable to provide a plurality of systems of sensor parts each including a weight and a trigger in parallel, and to operate a single drive device with the plurality of sensors. However, providing a plurality of sensors has a drawback that the size of the device is increased.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and its main purpose is to improve the operation reliability of a vehicle with a compact structure. It is to provide an acceleration detecting device for use.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, such an object is stored in advance in the sensor weight that is supported floatingly through the elastic means and the energy storage means. Energy releasing means for releasing energy, and trigger means for engaging the sensor weight to hold the energy releasing means in a non-operating position, and when a predetermined acceleration or deceleration acts on the vehicle An acceleration detecting device for a vehicle, wherein the energy releasing means is actuated by the displacement of the sensor weight, wherein the sensor weight is formed by combining a U-shaped rigid body in an inner and outer double structure and at both ends of each. And two pendulums that are pivotally supported by the sensor body of the vehicle acceleration detection device so that they can swing independently of each other about axes parallel to each other. It is accomplished by providing a vehicle acceleration detecting device according to symptoms.

<Operation> As described above, if the pendulum bent in a U shape is double combined, two pendulums that can swing independently of each other can be configured compactly. Moreover, since the pendulum can be suspended and supported at two points with a relatively wide interval, the swinging motion of the pendulum can be stabilized.

Therefore, it is possible to effectively reduce the probability of malfunction occurring without increasing the size of the structure.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show in detail an example of a vehicle acceleration detecting device constructed according to the present invention. A pair of pendulums 3a and 3b are suspended on both side surfaces of an upper portion of a sensor body 2 of the acceleration detecting device 1 so as to be swingable about an upper end portion thereof as a fulcrum. These pair of pendulums 3a
3b both have a U-shaped cross section whose upper side is open,
Both end portions 30a, 30b, 31a, 31b located above are respectively supported by support shafts 4a, 4b arranged in parallel with each other, and the inner and outer double layers are combined to interfere with each other's movements. Instead, it is possible to swing independently.

At the intermediate portion 5 of the sensor body 2 which protrudes into the space defined by the U-shaped portions of the two pendulums 3a and 3b, the front side is located along the tangential direction to the swing locus of the two pendulums 3a and 3b. An open cylindrical guide hole 6 is formed. A firing pin 7 for igniting a detonator such as a propellant as an energy storage means is inserted inside the guide hole 6.

The firing pin 7 is composed of a tip 8 and a bottomed cylindrical plunger 9 that slides into the guide hole 6, and the guide spring 6 is contracted between the bottom of the plunger 9 and the bottom of the guide hole 6 by a coil spring 10. It is constantly being urged toward the opening of.

A swing arm 11 is pivotally supported at a rear portion of the intermediate portion 5 of the sensor body 2 so as to be swingable downward. The free end portion 12 of the swing arm 11 is engaged with a bottom portion 13 immediately below the support shaft 4b of the inner pendulum 3b in the non-actuated position, whereby its downward swing is restricted.

On the free end side of the swing arm 11 in the middle portion, the trigger arm 1 is provided so as to be swingable in a seesaw manner via the support shaft 14.
5 is pivotally supported. The trigger arm 15 has a substantially crank shape in side view (FIG. 1) and a substantially U shape in front view (FIG. 2), and is a notch portion formed in the intermediate portion 5 of the sensor body 2 and opening downward. An upper open end 17 is projected from 16 into the guide hole 6, and the open end 17 is engaged with an engaging portion 18 formed on the plunger 9 of the firing pin 7.

On the bottom of the U-shaped portion of the outer pendulum 3a, a projecting piece 20 is provided so as to engage with the bottom of the U-shaped end 19 of the trigger arm 15 substantially directly below the support shaft 4a. There is. Then, the free end portion 12 of the swing arm 11 is engaged with the bottom portion 13 of the inner pendulum 3b, and the U-shaped end 19 of the trigger arm 15 is engaged with the protruding piece 20 of the outer pendulum 3a. The open end 17 of the engaging part 1 of the firing pin 7
By engaging with 8, the firing pin 7 is held stationary against the biasing force of the coil spring 10.

Inside the sensor body 2 facing the front end faces 21a and 21b at the bottoms of the two pendulums 3a and 3b, the two pendulums 3a and 3b are provided.
Of the bias springs 22a and 22b so that the bias springs 22a and 22b are on the center of the vertical direction and parallel to the axis of the guide hole 6.
Are juxtaposed. These bias springs 22a and 22b
Are in contact with the bottom front end surfaces 21a and 21b of the two pendulums 3a and 3b via the guide caps 23a and 23b, respectively, whereby the two pendulums 3a and 3b are always elastically urged rearward. .

In this way, the engagement between the protruding piece 20 of the outer pendulum 3a and the U-shaped end 19 of the trigger arm 15 and the engagement between the bottom portion 13 of the inner pendulum 3b and the free end portion 12 of the swing arm 11 are achieved. , Always kept.

Next, the operation procedure of the device of the present invention shown in the above embodiment will be described with reference to FIGS.

In a normal traveling state, the bias spring 2 corresponding to the moment of inertia acting on both pendulums 3a and 3b
The elastic forces of 2a and 22b are set so as to overcome each, and as shown in FIGS. 3 and 5, the swing arm 11 is engaged with the pendulum 3b on the inner side so that the support shaft 14 of the trigger arm 15 can be prevented. Is defined in its position, and at the same time the U-shaped end 19 of the trigger arm 15 is attached to the outer pendulum 3
When the trigger arm 15 is engaged with the protruding piece 20 of a.
The angle of is specified. Therefore, the trigger arm 15 is prevented from rotating, and the firing pin 7 is prevented from moving at the open end 17 of the trigger arm 15.

When the vehicle collides and a deceleration of a predetermined value or more acts in the traveling direction, the biasing forces of the bias springs 22a and 22b are overcome by the inertial forces of the two pendulums 3a and 3b, and the lower ends thereof are swayed forward. Both pendulums 3a and 3b tilt (4th
・ Figure 6 arrow Aa ・ Ab). This allows the outer pendulum 3
When the U-shaped end 19 of the trigger arm 15 is disengaged from the protrusion 20 of a, the restraint force by the open end 17 of the trigger arm 15 acting on the firing needle 7 is released, and the elastic force given by the coil spring 10 is released. Allows the open end 17 of the trigger arm 15 to
And the firing pin 7 is ejected toward the detonator F.

Further, when the free end 12 of the swing arm 11 is disengaged from the bottom 13 of the inner pendulum 3b, the swing arm 11 rotates downward (arrow B in FIG. 6). Then, the support shaft 14
Also, the free end 12 of the swing arm 11 is displaced downward together with the trigger arm 15, and the restraining force of the open end 17 of the trigger arm 15 against the shooting needle 7 is released in the same manner as described above, and the shooting needle 7 is ejected ( (Fig. 6).

When the tip 8 of the firing pin 7 strikes the detonator F, the propellant B is ignited, and the explosion pressure at this time drives a seat belt pro-leader device (not shown) or the like.

Now, in an acceleration detecting device for detecting such a vehicle collision, extremely high operational reliability is required. Therefore, in the present invention, as described in detail in the above embodiment, the pendulum 3a of two systems as the sensor weight is used.
3b is provided, and the engagement types of the pendulums 3a and 3b and the trigger means are different from each other. By doing so, for example, the protruding piece 2 of the outer pendulum 3a
0 and the U-shaped end 19 of the trigger arm 15 are stuck, or when the bottom 13 of the inner pendulum 3b and the free end 12 of the swing arm 11 are stuck, either of the pendulums 3a and 3b. Even if there is a problem in one of the engaging parts, the firing pin 7 is operated only by the operation of the other pendulum.
Is made possible.

In the above description of the operation, the individual pendulums have been described individually, but it goes without saying that the firing pin 7 is ejected without any change even when both pendulums 3a and 3b operate simultaneously.

By the way, the engaging force of each pendulum 3a, 3b with the swing arm 11 and the trigger arm 15 is mainly affected by the contact area between the two. Therefore, in order to reduce the manufacturing variation of this type of acceleration detection device, it is preferable that the dimensional accuracy of the contact portion of the above-mentioned engaging portion is increased as much as possible. Therefore, in the above embodiment, the distance from the fulcrum to each engaging portion is set to be larger than the distance from the fulcrum of each pendulum 3a, 3b to the position of the center of gravity. By doing so, the displacement of the center of gravity of each pendulum due to the inertial force is enlarged at each engaging portion, so that the size of the same portion can be set larger. Therefore, the management accuracy can be relatively relaxed.

On the other hand, in order to maintain a stable sensitivity characteristic, even if the trigger arm 15 is subjected to an inertia that is not released, the engaging portions of the pendulums 3a and 3b, the swing arm 11, and the trigger arm 15 are securely connected. I need to get back. In the above embodiment, in consideration of this point, both pendulums 3a, 3
b, the swing arm 11 and the trigger arm 15 are arranged so that the respective engaging portions are arranged substantially directly below the support shafts 4a and 4b of the pendulums 3a and 3b. At the same time, the two pendulums 3a and 3b are respectively supported at two points on the axis orthogonal to the displacement direction of the pendulum and spaced at appropriate intervals, and each bypass spring 22a is provided on the vertical line at the center between these support points.
・ The center of 22b is placed. By doing so, the operational stability of both pendulums 3a and 3b can be improved, and the elastic force of each bias spring 22a and 22b can act accurately on each pendulum 3a and 3b. Therefore, even when the pendulums 3a and 3b are slightly displaced, the engaging portions are not twisted, and the original position can be smoothly restored.

[Advantages of the Invention] As described above, according to the present invention, it is possible to provide two systems of the substantial detection device in a common body without increasing the size of the device. Therefore, it is possible to effectively eliminate the factor causing the malfunction of the acceleration detection device, further improve the reliability of the acceleration detection device, and achieve a great effect in making the structure compact.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention with a part thereof cut away, and FIG. 2 is a rear view of the same. 3 to 6 are explanatory views showing the operating state of the present embodiment. DESCRIPTION OF SYMBOLS 1 ... Acceleration detection device, 2 ... Sensor body 3a / 3b ... Pendulum, 4a / 4b ... Support shaft 5 ... Intermediate part, 6 ... Guide hole 7 ... Strike needle, 8 ... Tip 9 ... Plunger, 10 ... Coil spring 11 ... Swing arm , 12 ... Free end portion 13 ... Bottom portion, 14 ... Support shaft 15 ... Trigger arm, 16 ... Notch portion 17 ... Open end, 18 ... Engagement portion 19 ... U-shaped end, 20 ... Projection piece 21a / 21b ... Front end surface 22a / 22b ... Bias spring 23a / 23b ... Guide cap 30a / 30b / 31a / 31b ... End portion

Claims (3)

[Scope of utility model registration request] 1. A sensor weight floatingly supported via elastic means, an energy releasing means for releasing energy previously stored in an energy storing means, and the energy engaging with the sensor weight. Acceleration detecting means for a vehicle, which has a trigger means for holding the releasing means in a non-operating position, and the energy releasing means is activated by the displacement of the sensor weight when a predetermined acceleration or deceleration acts on the vehicle. In the device, the sensor weight has a rigid body bent in a U shape inside and outside 2
It is characterized by comprising two pendulums pivotally supported by a sensor body of the vehicle acceleration detection device so as to be combined with each other and swingable independently of each other about axes parallel to each other. Vehicle acceleration detection device. 2. The vehicle acceleration according to claim 1, wherein the energy releasing means and the trigger means are respectively disposed in a space inside a U-shaped portion of the pendulum. Detection device. 3. The first or second feature, wherein the resilient means comprises two coil springs arranged in parallel with each other on a vertical centerline between both pivotal support portions of the two pendulums. An acceleration detecting device for a vehicle according to claim 1.