JP2000085529A - Occupant protection device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start the function of a seat belt pre-tensioner by means of an independent condition whether or not the starting condition of an air bag is satisfied. SOLUTION: A collision judging part 401 makes a judgement on collision based on an acceleration signal A1. A starting timing control part 402 operates the starting timing of an air bag so as to output a trigger signal A6 after the aforesaid start timing is kept waiting. A start timing control part 408 operates the start timing of a pre-tensioner 62 so as to output a trigger signal A10 after the aforesaid start timing is kept waiting. A judging part 403 for lateral overturning and the like makes a judgement on lateral overturning based on an angular acceleration signal A2 when an occupant wears a seat belt. The start timing of the seat belt pre-tensioner is operated so as to allow a trigger signal A8 to be thereby outputted to a start timing control part 404, after the aforesaid start timing is kept waiting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection system for a vehicle, and more particularly, to start a seatbelt pretensioner based on angular acceleration regardless of whether or not an airbag activation condition is satisfied. The present invention relates to a vehicle occupant protection device.

[0002]

2. Description of the Related Art In recent years, occupant protection devices, such as airbag systems and seatbelt pretensioners, have become widespread in order to protect occupants from impacts caused by vehicle collisions. In this type of occupant protection device, an acceleration sensor installed in a proper position of the vehicle detects acceleration in the front-rear or left-right direction, or front-rear, left-right direction, and determines a collision based on the detected acceleration. When the collision is determined, the ignition device of the airbag and the pretensioner is activated, the airbag is inflated, and the seat belt is involved to restrain the occupant.

[0003]

The occupant protection device described above is designed to be activated when the vehicle collides with an obstacle at a predetermined speed or more and it is determined that protection by the occupant protection device is necessary. However, the protection function differs between the airbag and the seatbelt. In other words, the airbag has only a protection function to prevent the occupant from crashing forward in a frontal collision and from colliding laterally in a side collision.
The seatbelt pretensioner retracts the seatbelt and restrains the occupant in the seat, so the occupant crashes forward in a frontal collision, laterally in a side impact, and upward in a vehicle rollover. Can also be blocked.

[0004] As described above, the conventional seatbelt pretensioner is configured to start in response to the start signal of the airbag although the protection function is different between the airbag and the seatbelt. However, the occupant protection ability of the seatbelt pretensioner could not be fully utilized.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle occupant protection device which can solve the above-mentioned problems of the prior art and can fully utilize the occupant protection ability of a seat belt pretensioner.

[0006]

In order to achieve the above object, the present invention provides a pretensioner for retracting a seat belt to restrain an occupant, and an angular acceleration detecting means for detecting an angular acceleration of the vehicle in a rollover direction. A rollover determining means for determining whether or not a change in posture such as rollover has occurred in the vehicle based on the angular acceleration detected by the angular acceleration detecting means; and a change in posture such as rollover by the rollover etc. determination means. And a pretensioner activating means for activating the pretensioner when it is determined that the occurrence has occurred.

According to the above configuration, the seatbelt pretensioner is activated based on the angular acceleration generated in the vehicle. Therefore, as in the case where the vehicle changes in posture such as rollover, the airbag is conventionally used. The seatbelt pretensioner can be started even in a collision mode in which the pretensioner could not be started because it was not started.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a main part of a vehicle occupant protection device according to one embodiment of the present invention.

[0009] The acceleration sensor 11 detects acceleration generated in the front-rear or left-right direction of the vehicle, or in the front-rear-right direction, and outputs an acceleration signal A1. The acceleration signal A1 is A / D
The signal is converted into a digital signal by the converter 21 and input to the CPU 40 via the I / O 30. The angular acceleration sensor 12
An acceleration generated in the rollover direction of the vehicle, that is, an angular acceleration is detected, and an angular acceleration signal A2 is output. Angular acceleration signal A2
Is a CPU via the A / D converter 22 and the I / O 30
Input to 40.

The seat belt speed sensor 13 detects the speed of pulling out the seat belt and outputs a speed signal A3. The speed signal A3 is output from the A / D converter 23 and the I / O3
0 is input to the CPU 40. The seat belt wearing sensor 14 detects whether the occupant is wearing a seat belt and outputs a wearing signal A4. Wearing signal A4
Is a CPU via the A / D converter 24 and the I / O 30
Input to 40.

When the CPU 40 receives various signals via the I / O 30, the CPU 40 executes an occupant protection program stored in the ROM 51 in advance, and switches the switching transistor 71 as an airbag activating means and the pretensioner activating means. The switching transistor 72 is controlled. The RAM 52 functions as a work area when executing the occupant protection program.

One end of each of the squib resistors 61a, 62a of the airbag 61 and the seat belt pretensioner 62 is connected to the power supply line L, and the other end is grounded via the switching transistors 71, 72, respectively. The power supply line L has a capacitor 7 for supplying a current to each of the squib resistors 61a and 62a.
3 and the battery 74 are connected.

FIG. 2 is a functional block diagram of the CPU 40. The same reference numerals as those described above denote the same or equivalent parts.

The collision determination unit 401 performs a collision determination process using the magnitude and waveform of the acceleration signal A1 output from the acceleration sensor 11 as parameters, and outputs a collision occurrence signal A5 when a predetermined collision condition is satisfied. The activation timing control unit 402 receives a collision occurrence signal A from the collision determination unit 401.
When 5 is output, the activation timing of the airbag 61 is calculated based on the acceleration signal A1, and after the activation timing, the trigger signal A6 is output. AND circuit 405
Outputs the logical product of the collision occurrence signal A5 and the trigger signal A6 to the base of the switching transistor 71 as an airbag activation signal A9.

When a collision occurrence signal A5 is output from the collision judging section 401, the activation timing control section 408 calculates an activation timing of the pretensioner 62 based on the acceleration signal A1, and waits for the activation timing to trigger a trigger signal. A10 is output. The AND circuit 409 outputs a logical product of the collision occurrence signal A5 and the trigger signal A10 to the OR circuit 407 as a pretensioner activation signal A12.

A rollover determining section 403 determines whether or not the occupant is wearing a seatbelt based on a wearing signal A4 output from the seatbelt wearing sensor 14. Rollover determination is performed using the magnitude and waveform of the angular acceleration signal A2 output from the acceleration sensor 12 as parameters. When the predetermined rollover condition is satisfied, it is determined that the vehicle has undergone a rollover or a posture change close to the rollover, and a rollover etc. occurrence signal A7 is output.

The start timing control unit 404 includes a speed signal A3 output from the seat belt speed sensor 13.
Is input, and when the rollover etc. occurrence signal A7 is output from the rollover etc. determination unit 403, the start timing of the seat belt pretensioner 62 is calculated based on the speed signal A3. Is output. The AND circuit 406 calculates the logical product of the rollover etc. occurrence signal A7 and the trigger signal A8 by a pretensioner activation signal A
It outputs to the OR circuit 407 as 11. OR circuit 407
Outputs the logical sum of the pretensioner activation signals A11 and A12 to the base of the switching transistor 72 as a pretensioner activation signal A13.

Next, the operation of the present invention will be described in detail with reference to the flowchart of FIG. When the CPU 40 starts the occupant protection program, the airbag activation algorithm and the pretensioner activation algorithm are executed in parallel by time division processing or interrupt processing.

In the airbag activation algorithm, in step S11, the acceleration signal A1 output from the acceleration sensor 11 is taken into the collision determination unit 401. In step S12, the acceleration G responding to the level of the acceleration signal A1 is compared with the collision determination reference acceleration Gref. If the detected acceleration G exceeds the collision determination reference acceleration Gref, a collision determination process is executed in step S13. You.

In step S13, the collision determination unit 401 performs a collision determination process using the magnitude and waveform of the acceleration signal A1 as parameters, and outputs a collision occurrence signal A5 when predetermined collision conditions are satisfied. In step S14, the activation timing control section 402 calculates the activation timing of the airbag 61 in response to the collision occurrence signal A5,
When the start timing is reached in step S15, step S1
At 6, a trigger signal A6 is output.

At this time, since the collision occurrence signal A5 is output from the collision judging section 401 and the AND circuit 405 is in the enabled state, the airbag activation signal A9 is input from the AND circuit 405 to the base of the switching transistor 71. . As a result, the switching transistor 71 conducts, and the electric charge stored in the capacitor 73 is supplied to the squib resistance 61a of the airbag 61, so that the airbag 61 is activated.

Further, when the collision occurrence signal A5 is output in step S13, in step S31, the activation timing control unit 408 calculates the activation timing of the pretensioner 62 in response to the collision occurrence signal A5. When the activation timing has been reached in step S32, the activation timing control unit 408 outputs a trigger signal A10.

At this time, since the collision occurrence signal A5 is output from the collision determination unit 401 and the AND circuit 409 is in an enabled state, the pretensioner activation signal A12 is output from the AND circuit 409 and the OR circuit 407 The signal is input to the base of the switching transistor 72. As a result, the switching transistor 72 conducts, and the electric charge stored in the capacitor 73 is supplied to the squib resistor 62a of the pretensioner 62, and the pretensioner is started.

On the other hand, in the pretensioner activation algorithm, in step S21, the rollover etc. determination unit 403 outputs the wearing signal A4 output from the seat belt wearing sensor 14.
It is determined whether or not the occupant is wearing the seat belt based on the.
Angular acceleration signal A output from angular acceleration sensor 12
Import 2.

In step S23, rollover determination processing is executed based on the level and waveform of the angular acceleration signal A2. If the angular acceleration signal A2 exceeds a predetermined value, it is determined that rollover or a posture change close to rollover has occurred. And outputs a rollover etc. occurrence signal A7. In step S24, the seat belt withdrawal speed signal A3 detected by the seat belt speed sensor 13 is taken into the activation timing control unit 404.

In step S25, the activation timing control unit 404 calculates the activation timing of the pretensioner 62 based on the seat belt speed signal A3, and then proceeds to step S25.
When the start timing is reached at 26, the trigger signal A
8 is output. This trigger signal A8 is supplied to the AND circuit 406.
Is input to the base of the switching transistor 72 via the. As a result, the switching transistor 72 conducts, and the electric charge stored in the capacitor 73 is supplied to the squib resistor 62a of the pretensioner 62, and the pretensioner 62 is started.

As described above, according to the present embodiment, the seatbelt pretensioner 62 is activated based on the angular acceleration generated in the vehicle. In addition, even in a collision mode in which the pretensioner could not be activated because the airbag was not activated in the past, the seatbelt pretensioner can be activated.

In this embodiment, the start timing of the pretensioner is calculated based on the pull-out speed of the seat belt, so that the pretensioner can be started at an optimum timing.

Further, in this embodiment, when the activation condition of the airbag is satisfied, the pretensioner is also activated regardless of the presence or absence of the angular acceleration, and the activation timing of the pretensioner at that time is calculated based on the acceleration signal. As a result, the pretensioner can always be started at an optimum timing regardless of the type of collision.

[0030]

According to the present invention, the following effects are achieved. (1) According to the first aspect, the seatbelt pretensioner is activated based on the angular acceleration generated in the vehicle. The seatbelt pretensioner can be started even in a collision mode where the pretensioner could not be started because it was not started. (2) According to the second aspect, the start timing of the pretensioner is calculated based on the pull-out speed of the seat belt, so that the pretensioner can be started at an optimum timing. (3) According to the third aspect, when the activation condition of the airbag is satisfied, the pretensioner is also activated regardless of the presence or absence of the angular acceleration, and the activation timing of the pretensioner at that time is calculated based on the acceleration signal. Therefore, the pretensioner can always be started at an optimum timing regardless of the collision type.

[Brief description of the drawings]

FIG. 1 is a block diagram of a vehicle occupant protection device according to an embodiment of the present invention.

FIG. 2 is a block diagram functionally showing a configuration of a CPU in FIG. 1;

FIG. 3 is a flowchart showing the operation of the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Acceleration sensor, 12 ... Angular acceleration sensor, 13 ... Seat belt speed sensor, 14 ... Seat belt wearing sensor, 61 ... Airbag, 61 ... Seat belt pretensioner

Claims (3)

[Claims] A seat belt pretensioner for retracting a seat belt to restrain an occupant; an angular acceleration detecting means for detecting an angular acceleration of the vehicle in a rollover direction; and an angular acceleration detected by the angular acceleration detecting means. A rollover determining means for determining whether or not a change in posture such as a rollover has occurred in the vehicle based on the vehicle; and activating the pretensioner when the rollover or the like determines that the posture change such as a rollover has occurred. An occupant protection device for a vehicle, comprising: 2. A seat belt speed detecting means for detecting a pull-out speed of a seat belt, and a starting timing control means for determining a starting timing of the pretensioner based on the seat belt speed detected by the seat belt speed detecting means. The vehicle occupant protection device according to claim 1, further comprising: the pretensioner activation unit activates the pretensioner at an activation timing determined by the activation timing control unit. 3. An airbag, acceleration detection means for detecting acceleration generated in the vehicle, collision determination means for determining whether a collision has occurred based on the acceleration detected by the acceleration detection means, Airbag activation means for activating the airbag at a predetermined timing when the collision determination means makes a collision determination; and second activation timing control means for determining activation timing of the pretensioner based on the acceleration. Wherein the pretensioner activation unit activates the pretensioner at the activation timing determined by the second activation timing control unit when a collision determination is made by the collision determination unit. The vehicle occupant protection device according to claim 1 or 2, wherein: