JPH0710656B2 - Vehicle occupant protection device - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a vehicle occupant protection device that protects an occupant in the event of a vehicle collision.

[Prior art]

2. Description of the Related Art As a conventional vehicle occupant protection device, for example, there is one as shown in FIG. In the figure, reference numeral 1 denotes an acceleration sensor for detecting an acceleration signal of a vehicle, and a complete integration circuit in which the acceleration signals detected by the acceleration sensor 1 are serially connected in two stages.
Double-integrate with 2, 3 and when the integrated output exceeds a predetermined level, ignition device such as airbag system (not shown)
To protect the occupant by inflating the airbag and tightening the seat belt.

[Problems to be Solved by the Invention]

However, in such a conventional vehicle occupant protection device, for example, the integrating circuits 2 and 3 for calculating the amount of movement of the occupant that is determined to be a bad road are reset (created by another circuit not shown, In case of a bad road judgment reset signal output when it is judged that the vehicle is traveling), the inverting input and non-inverting input of the operational amplifiers 2a, 3a of the integrating circuits 2, 3 are short-circuited by the discharge switches 2b, 3b. Therefore, due to the residual resistance of the short-circuiting switch circuit, the voltage Vr
Remains, and the output of the operational amplifiers 2a and 3a However, there is a problem that the voltage cannot be reliably reset. The present invention has been made to solve the above problems, and an object thereof is to obtain a vehicle occupant protection device capable of reliably short-circuiting and discharging an integrating capacitor when resetting an integrating circuit. To do.

[Means for Solving the Problems]

An occupant protection device for a vehicle according to the present invention turns on upon receiving a reset signal when the acceleration sensor detects an acceleration signal and the detection output of the acceleration sensor and the acceleration signal is a signal without danger. An integrating circuit in which a discharging switch is connected in parallel to an integrating capacitor, a comparing circuit that outputs a trigger signal when the output of the integrating circuit exceeds a predetermined threshold value, and an occupant that operates by receiving the trigger signal from the comparing circuit. It consists of a protective device body.

[Action]

The vehicle occupant protection device according to the present invention integrates the detection output of the acceleration sensor, and when the acceleration signal is a signal without danger, the discharge switch connected in parallel to the integration capacitor receives the reset signal. It is designed to discharge the integrating capacitor.

【Example】

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.
In the figure, the same or equivalent components as in FIG. First, the configuration will be described. In the figure, 4 is a first incomplete integration circuit for incompletely integrating the detection signal from the acceleration sensor 1, and 5 is a first incomplete integration circuit for incompletely integrating the integrated output of the first incomplete integration circuit 4. 2 incomplete integrator circuits
The incomplete integration circuits 4 and 5 are obtained by connecting integration capacitors 4a and 5a and resistors 4b and 5b between the respective inverting input terminals and output terminals. 6a and 6b are discharge switches connected in parallel to the integration capacitors 4a and 5a.
b operates by receiving a reset signal when the acceleration signal is a signal without danger. Reference numeral 7 is a comparison circuit for comparing the integrated output of the second incomplete integration circuit 5 with a reference value. This comparison circuit 7 switches the output level to a high level when the integrated output exceeds the reference value. Reference numeral 8 is a drive circuit, and 9 is an ignition device which is the body of the occupant protection device. The ignition device 9 operates the airbag based on the output of the drive circuit 8. Next, the operation will be described. First, an acceleration signal having a collision waveform generated when a vehicle collides is detected by an acceleration sensor 1 attached to the vehicle, and is supplied to first and second incomplete integration circuits 4 and 5 to be subjected to incomplete double-stack integration. It When the resulting integrated output from the second incomplete integration circuit 5 exceeds the reference value of the comparison circuit 7, a high level signal is supplied to the drive circuit 8 to momentarily inflate the airbag to protect the occupant. . Further, even if the detection output of the acceleration sensor 1 is supplied to the first and second incomplete integration circuits 4 and 5 by traveling on a bumpy road surface or applying a sudden brake during normal traveling, the acceleration signal is dangerous. When the signal is not accompanied, a reset signal is supplied to the discharge switches 6a, 6b to short-circuit the discharge switches 6a, 6b and discharge the integration capacitors 4a, 5a. At this time, the output voltage due to the influence of the residual resistance (r) of the discharging SW And the output voltage in the case of the conventional circuit diagram 2. It gets smaller. Therefore, the integrated output of the second incomplete integration circuit 5 does not exceed the reference value of the comparison circuit 7, so that the ignition current is not supplied to the ignition device 9 via the drive circuit 8. In the above embodiment, the first and second incomplete integration circuits are used.
It goes without saying that the time constants of 2 and 3 may be the same or different. Further, in the above embodiment, the ignition current is supplied to the ignition device 9 to deploy the airbag, but it goes without saying that the seat belt tensioning device may be activated.

【The invention's effect】

As described above, according to the present invention, the configuration is provided with an acceleration sensor that detects an acceleration signal and an integration circuit that inputs a detection output from the acceleration sensor, and the acceleration signal is input to the integration circuit. The occupant is protected by operating the occupant protection device body by judging that the integrated value exceeds the threshold value, while stopping the integration operation when the acceleration signal is a signal without danger. Since the reset signal is generated and the integrating circuit has a configuration in which a discharging switch that is turned on by receiving the reset signal is connected in parallel to the integrating capacitor, the residual output voltage V ₀ becomes smaller than that of the conventional one as shown by the following formula. The effect that the occupant protection device main body does not malfunction due to noise such as the acceleration sensor output due to drift or sudden braking, and the charge of the integration capacitor can be reliably discharged is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a vehicle occupant protection device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing an example of a conventional vehicle occupant protection device. 1 ... Acceleration sensor, 4,5 ... Integrator circuit, 9 ... Ignition device, 4a, 5a ... Integrating capacitor, 6a, 6b ... Discharge switch. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An acceleration sensor (1) for detecting an acceleration signal.
And an integrator circuit (2, 3) for inputting the detection output from this acceleration sensor, inputting an acceleration signal into this integrator circuit for integration, and judging that the integrated value exceeds a threshold value In the vehicle occupant protection device for generating a reset signal for stopping the integration operation when the acceleration signal is a signal without danger while operating the protection device body to protect the occupant, the integration circuit (4 , 5) is a vehicle occupant protection device characterized in that discharge switches (6a, 6b) that are turned on in response to the reset signal are connected in parallel to the integrating capacitors (4a, 5a).