JPH0262967A - Sensor - Google Patents

Abstract

PURPOSE: To readily execute detection even when this sensor is built in by a constitution wherein a bonding wire is extended above a pendulum and the bonding wire is fixed to both ends of a holding body and is a part of a closed electric circuit. CONSTITUTION: When an acceleration force acts on a sensor 11, a pendulum 12 is displaced from a non-operation position. Thereby, a projection piece 14 is bent or twisted in a range of a distortion measuring condition 15, then a resistance variation in proportion to the condition is created. The resistance variation is estimated by an estimation circuit to be sent to a control device. A bonding wire 17 is a mechanical stopper for the vibrating pendulum 12. A length of the bonding wire 17 is adjusted to a desired height of the maximum amplitude of the pendulum 12. When an over load is applied, the amplitude of the pendulum 12 is limited by the bonding wire 17. When the over load exceeds the limit, the bonding wire 17 is cut and an electric circuit is shut off. Thereby, an alarming device is activated, the destruction of the sensor 11 is detected and indicated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a monocrystalline material in which a pendulum is etched, which emits a control signal when a vehicle or a vehicle part deviates from its permissible position, and has a mass of one square centimeter. The present invention relates to a sensor for measuring acceleration, for example for automatically actuating a passenger protection device in a vehicle, in particular a motor vehicle, having a holder made of

[Conventional technology]

In acceleration detectors, it is known to limit the oscillations of a pendulum with seismic mass by means of a mounted housing. The N width is thereby limited, but the vibrating mass can easily be completely or partially stopped. However, this loss of the sensor cannot be checked in the installed state.

[Problem to be solved by the invention]

The object of the invention is to avoid the above-mentioned disadvantages.

[Means to solve the problem]

This problem is solved in that a glue line runs over the pendulum, which glue line is fixed at both ends of the holder and is part of a closed electrical circuit.

〔Effect of the invention〕

The sensor according to the invention with the features of claim 1 has the advantage that, in the event of an overload, the accelerated seismic mass is limited in vibration amplitude by the adhesive wire. If the overload exceeds a predetermined limit value due to the strength of the adhesive wire, this wire breaks and the electrical circuit is interrupted. The operating capacity of the sensor can thereby be easily detected and displayed even in the installed state. Furthermore, even during the manufacture of the sensor, the risk of damage to the sensor is reduced and the manufacturing process is improved by the simple manipulation of the adhesive wire.

By the means described in the embodiment section of the claims,
Advantageous further embodiments of the sensor mentioned in claim 1 are possible.

〔Example〕

Embodiments of the invention are shown in the drawings and explained in detail below.

In FIG. 1, a small piece of silicon is indicated at 10;
This silicon piece forms the housing of the sensor 11. Since the pendulum 12 of the sensor 11 used as the seismic mass is etched on the surface of the silicon piece,
An outer frame 13 is obtained. In this case, anisotropic and selective etching techniques can be used. Furthermore, it is also possible to use other manufacturing methods conventionally known from IC manufacturing. The pendulum 12 is etched from its surface in such a way that a lug 14 is formed which elastically suspends the pendulum from the frame 13. This lug 14 can act as a twisting lug or a bending lug.

In order to measure the deformation of the lug 14, which is proportional to the acceleration and deflection exerted by the pendulum 12, a strain measuring strip 5 is arranged on the lug 14.

The measurement signal of this strain-measuring strip is fed to an evaluation circuit (not shown). In the area of the end of the pendulum 12 opposite the lug 14, an adhesive line 17 is provided, which is attached at both ends to the silicon strip 10 by means of adhesive pads 18.

However, the adhesive line 17 can also be placed on the pendulum 12 at any other point. The adhesive wire 17 is part of a closed electrical circuit, of which the conductor 19 connected to the adhesive pad 18 is not shown in detail. This electrical circuit can be connected to the electrical circuit of the strain measuring strip 15 or can be led to its own reporting device.

An acceleration force acting on sensor 11 causes pendulum 12 to deflect from its inactive position. As a result, the projection 14 is bent or twisted in the area of the strain-measuring strip 15, thereby producing a proportional resistance change in this strain-measuring strip. This resistance reduction is evaluated in an evaluation circuit (not shown) and is further sent to a control device.

This control device can be used, for example, as a belt tensioner, an airbag,
Activate the vehicle's passenger protection devices such as rollpers, warning flashers, central restraints, or brake locking devices. Furthermore, it is also possible to control anti-sticking devices and/or chassis adjustment devices. For the vibrating pendulum 12, the adhesive line 17 is a mechanical stop. The length of this glue line, that is, the height of the loop of this glue line is 1
2 to the desired maximum vibration height. In the event of overload, ie if the acceleration forces are too high, the pendulum I2 is limited in its amplitude by the adhesive line 17. If this overload is further exceeded, the adhesive wire 17 will break and the electrical circuit will be interrupted. This activates the alarm system,
This alarm device is capable of detecting and indicating destruction of the sensor 11.

[Brief explanation of the drawing]

The drawing is a perspective view of the sensor. 10... Holder, 11... Sensor, 12... Pendulum, 17... Pa adhesive wire

Claims (1)

Claims: 1. Having a holder (10) made of monocrystalline material, in which is etched a pendulum (12) which emits a control signal and has a seismic mass when the vehicle or vehicle part deviates from its permissible position;
In a sensor for measuring acceleration, for example for automatically activating a passenger protection device in a vehicle, in particular a motor vehicle, a bonding line (17) runs on the pendulum (12), which bonding line connects to the holding body (10). ) and is part of a closed electrical circuit. 2. Sensor according to claim 1, characterized in that the adhesive line (17) is arranged in the area of the free end of the pendulum (12). 3. The adhesive line (17) is connected to the adhesive pad (
18) Sensor according to one of claims 1 and 2, characterized in that it is attached to a sensor. 4. Sensor according to one of claims 1 to 3, characterized in that the holder (10) is a piece of silicon.