JP2959316B2 - Drive for occupant restraint - Google Patents

Abstract

PURPOSE:To feed a necessary and sufficient current to a squib so as to actuate an occupant restraint system when a vehicle collision is detected. CONSTITUTION:To the driving device of an occupant restraining device 100 in which a driving element 101 to operate the occupant costraining device 100, the first switch 102 to close by detecting a specific impact, and the second switch 103 to close according to the deceleration of the vehicle are connected in series, and a starting power is fed from a power source 10A to a starting element 101 when both the first and the second switches 102 and 103 are closed, a detecting means 105 to detect that the first switch 102 is closed is provided. Furthermore, a control means 106 to close the second switch 103 according to the deceleration of the vehicle when the detecting means 105 detects that the first switch 102 is closed, is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for an occupant restraint device for restraining and protecting an occupant in a collision.

[0002]

2. Description of the Related Art A start switch (hereinafter referred to as a squib) for operating an occupant restraint device such as an air bag is provided with a first switch that closes by a relatively small impact and a second switch that closes by a relatively large impact. And a driving device for an occupant restraint system in which the driving device is connected in series (for example,
See JP-A-2-63954). In this type of drive device, at the time of a vehicle collision, the first switch is closed first,
Subsequently, when the second switch is closed, a current flows from the power supply to the squib, and the occupant restraint device operates.

[0003]

However, in the above-described driving apparatus of the conventional occupant restraint system, even if the closing of the first switch is delayed for some reason and the first switch is closed after the closing of the second switch, the occupant cannot be closed. To ensure the operation of the restraint system, the power supply voltage must be increased and sufficient current must flow through the squib. Therefore, the electric circuit must be able to withstand a high voltage, and there is a problem that the device becomes large and the cost increases.

SUMMARY OF THE INVENTION It is an object of the present invention to allow a squib to supply a necessary and sufficient current to operate an occupant restraint system when a vehicle collision is detected.

[0005]

The present invention will be described with reference to FIG. 1 which is a claim correspondence diagram.
And a first switch 1 that closes upon detecting a predetermined impact G1
01 and a second switch 102, which is opened and closed based on the deceleration g of the vehicle detected by the deceleration detecting means 109, are connected in series, and when both the first switch 101 and the second switch 102 are closed, A driving device of an occupant restraint device 104 that is supplied with starting power to the starting element 103 from the vehicle, the closing device detecting means 105 detecting that the first switch 101 is closed, and the occupant restraining device based on the deceleration g of the vehicle. When the operation of the occupant restraint device 104 is determined by the operation necessity determining means 108 which determines the necessity of operation of the occupant 104 and outputs an operation signal, and when the operation necessity determination means 108 determines the operation, the deceleration g of the vehicle becomes a predetermined value. An operation signal holding unit 107 for holding an operation signal until the impact G1 or less, and a first switch 101 by a closed circuit detection unit 105 when the operation signal is held. When closed is detected the second switch 1
02 for closing the circuit 02. Further, the driving device of the occupant restraint device according to the second aspect is configured such that when the operation signal is held by the control means 106, the occupant restraint device 1
In this embodiment, the second switch 102 is closed for a time necessary for the operation of the switch 04.

[0006]

According to the driving device for an occupant restraint device of the first aspect, the first
In addition to detecting the closing of the switch 101, it determines whether or not the occupant restraint device 104 needs to be operated based on the deceleration g of the vehicle, and outputs an operation signal. Then, the occupant restraint device 104
Is determined, the deceleration g of the vehicle becomes equal to the predetermined impact G.
The operation signal is held until it becomes 1 or less, and when the closing of the first switch 101 is detected while the operation signal is held, the second switch 102 is closed. As a result, the first switch 101 and the second switch 102 are closed at the same time, the starting power is supplied from the power supply 100 to the starting element 103, and the occupant restraint device 104 operates. In the driving device for an occupant restraint device according to the second aspect, when the operation signal is held, the second switch 1 is turned on for a time necessary for the operation of the occupant restraint device 104.
02 is closed. As a result, the first switch 101 and the second switch 102 are simultaneously closed for the time required for the operation of the occupant restraint device 104, and the starting power is supplied from the power supply 100 to the starting element 103, so that the occupant restraint device 104 is operated.

[0007]

【Example】

-First Embodiment- FIG. 2 is a block diagram showing a configuration of the first embodiment. A driving device for operating an occupant restraint device such as an air bag includes a squib 1, a transistor 2, and an impact detection sensor 3 connected in series, and when the transistor 2 and the impact detection sensor 3 conduct, the power supply circuit 4 → the transistor 2 →
Current flows through the path of squib 1 → sensor 3 → ground. The impact detection sensor 3 is provided, for example, in a floor tunnel of a vehicle, and when a predetermined impact is detected, its contact is closed. The control circuit 5 controls the operation of the transistor 2 based on the deceleration g detected by the deceleration sensor 6. The deceleration sensor 6 is provided, for example, in a floor tunnel portion of the vehicle, and detects a deceleration g of the vehicle at the time of a collision.
The resistors 7 and 8 have a high resistance value, are connected in parallel to the transistor 2 and the shock detection sensor 3, respectively, and are used to detect the operation state of the shock detection sensor 3.

The power supply circuit 4 includes a circuit for supplying power to the squib 1 from the battery 41 via the diode 42, a circuit for boosting the terminal voltage of the battery 41 by the booster circuit 43 and supplying power to the squib 1 via the diode 44, A capacitor 45 which is constantly charged to a high voltage by the booster circuit 43 and supplies power to the squib 1 as an auxiliary power supply in the event of a collision, and reliably supplies power to the squib 1 in any case.

The control circuit 5 comprises a microcomputer and its peripheral components, and controls the operation of the transistor 2 by executing a control program described later. Control circuit 5
Are functionally equivalent to the collision determination unit 51 and the collision determination latch unit 5.
2. Sensor operation detection unit 53 and start signal output unit 54
Can be divided into The collision determination unit 51 determines whether or not the collision requires the operation of the occupant restraint device on the basis of the deceleration g of the vehicle detected by the deceleration sensor 6, and when it determines that the operation is required, outputs the operation determination signal T0 to the collision determination. Output to the latch unit 52. Upon receiving the operation determination signal T0 from the collision determination unit 51, the collision determination latch unit 52 latches the operation determination signal T0 for a period during which the deceleration g is equal to or greater than the preset value G1, and outputs the latch signal T0 'to the activation signal output unit 54. Output to Here, the set value G1 is a detection level of the impact detection sensor 3. The sensor operation detection unit 53 detects the operation of the impact detection sensor 3 and outputs an operation signal S to the activation signal output unit 54. When receiving the latch signal T0 ′ from the collision determination latch unit 52 and the activation signal S from the sensor operation detection unit 53, the activation signal output unit 54 outputs the activation signal T1 for turning on the transistor 2 for a predetermined time t.
Only to the base of transistor 2.

FIGS. 3 to 5 are flowcharts showing control programs executed by the microcomputer of the control circuit 5. FIG. The operation of the first embodiment will be described with reference to these flowcharts. FIG. 3 shows a collision determination processing routine of the collision determination unit 51 and the collision determination latch unit 52.
The microcomputer executes this processing routine at a predetermined cycle. In step S1, the deceleration g of the vehicle detected by the deceleration sensor 6 is read.
Based on the deceleration g detected in step 2, the necessity of the operation of the occupant restraint device is determined by a predetermined algorithm. It should be noted that various algorithms for determining whether or not to operate the occupant restraint system based on the deceleration g have already been proposed and will not be described because they are not directly related to the present invention. Step S
In step 3, it is determined whether or not the operation is performed. If the operation is performed, the process proceeds to step S4; otherwise, the process proceeds to step S7. Step S
At 7, the low level is set to the operation determination signal T0 and the latch signal T0 ', and the collision determination process ends.

When the operation of the occupant restraint system is determined, the operation determination signal T0 and the latch signal T0 'are made in step S4.
Is set to the high level, and the routine proceeds to step S5, where the deceleration g of the vehicle detected by the deceleration sensor 6 is read again. It is determined whether or not the deceleration g detected in the subsequent step S6 is equal to or greater than the set value G1, that is, whether or not the deceleration g of the vehicle is equal to or greater than the detection level of the impact detection sensor 3. Returning to step S5,
Otherwise, go to step S7. That is, once the operation of the occupant restraint system is determined based on the deceleration g of the vehicle, the operation determination signal T0 is latched only during the period when the deceleration g is equal to or higher than the detection level of the impact detection sensor 3. On the other hand, when the deceleration g is lower than the detection level of the impact detection sensor 3, the operation determination signal T0 and the latch signal T0 'are set to low level in step S7, and the collision determination process ends.

FIG. 4 shows an operation detection processing routine of the sensor operation detection section 53. The microcomputer executes this processing routine at a predetermined cycle. In step S11, it is determined whether or not the impact detection sensor 3 has been activated. In the drive circuit of the squib 1, even if the transistor 2 and the shock detection sensor 3 are not conducting, a minute current I1 always flows through the path of the power supply circuit 4 → the resistor 7 → the squib 1 → the resistor 8 → the ground. . When the impact detection sensor 3 is in a non-operation state, a potential proportional to the product (I1 · R8) of this minute current I1 and the resistance value R8 of the resistor 8 is generated at the point A in FIG. However, when the impact detection sensor 3 operates, the point A is short-circuited to ground by the contact, and the potential at the point A becomes zero. Therefore, the potential at point A is detected, and if the potential is equal to or higher than a predetermined level, the impact detection sensor 3 is determined to be inactive, and if the potential is lower than the predetermined level, it is determined that the impact detection sensor 3 is active. If the shock detection sensor 3 is operating, the process proceeds to step S12, and the operation signal S
Is set to high level, and if it is not operating, step S
Proceeding to 13, the operation signal S is set to a low level.

FIG. 5 shows a start signal output processing routine of the start signal output section 54. The microcomputer executes this processing routine at a predetermined cycle. In step S21, it is determined whether or not the activation signal S is at a high level. If the activation signal S is at a high level, the process proceeds to step S22; otherwise, the activation signal output process ends. In step S22, it is determined whether the latch signal T0 'is at a high level. If the latch signal T0' is at a high level, the process proceeds to step S23; otherwise, the activation signal output process ends. If the activation signal S is at the high level and the latch signal T0 'is at the high level, step S23
Sets the start signal T1 to a low level and outputs the signal, thereby turning on the transistor 2. At this time, since the contact of the impact detection sensor 3 is closed, the starting current I flows through the power supply circuit 4 → transistor 2 → squib 1 → impact detection sensor 3 → earth.

In step S24, a timer for managing the output time of the activation signal T1 is started.
At 5, it is determined whether or not the timer has expired. The timer is set to a time t during which the occupant restraint device operates reliably when the starting current I flows. If the activation signal T1 has been output for the time t, the process proceeds to step S26; otherwise, the process proceeds to step S26. In step S2 6 to set the high level to the start signal T1 output, transistor 2
Is turned off. On the other hand, in step S27, the operation signal S
It is determined whether both the latch signal T0 'and the latch signal T0' remain at the high level. If both remain at the high level, the output of the activation signal T1 is continued and the process returns to the step S25, and one of them has changed to the low level. If so, the process proceeds to step S26 to stop the output of the activation signal T1.

FIG. 6 shows the operation signal S, the deceleration g, and the deceleration g when the operation of the impact detection sensor 3 is delayed for some reason at the time of a vehicle collision and the operation of the occupant restraint system is determined first based on the deceleration g. 6 is a time chart illustrating changes in a latch signal T0 ′, a start signal T1, and a start current I. Time t
Assuming that the deceleration g of the vehicle exceeds the detection level G1 of the deceleration detection sensor 3 at 1 and the operation of the occupant restraint device is determined at time t2 and the operation determination signal T0 is output, at time t2
, The latch signal T0 ′ becomes high level. At this time, since the shock detection sensor 3 has not been operated yet, the starting signal T1 is not output, and the starting current I remains almost zero. Strictly, as described above, even when the transistor 2 and the impact detection sensor 3 are in a non-conductive state, the minute current I1 flows through the resistors 7 and 8, but the minute current I1 is Is very small as compared with the specified current I that activates the current.

If the shock detection sensor 3 is activated at time t3, the activation signal S goes high, and both the activation signal S and the latch signal T0 'are high, so that a low-level activation signal T1 is output. , The transistor 2 is turned on, and the prescribed current I for operating the occupant restraint system starts flowing to the squib 1. As long as the activation signal S and the latch signal T0 'are both at the high level, the activation signal T1 is kept at the low level for the time t, and the activation current I continues to flow. As a result, the occupant restraint device is activated by the squib 1. Thereafter, when the deceleration g becomes lower than the detection level G1 at time t5, the latch signal T0 'becomes low.

As described above, the transistor 2 is turned on in accordance with the deceleration g of the vehicle when the closed circuit of the shock detection sensor 3 is detected.
And the transistor 2 conduct simultaneously, the starting power is supplied from the power supply circuit 4 to the squib 1, and the occupant restraint device operates.

In the first embodiment described above, the deceleration
When the operation of the occupant restraint device is determined based on g , the latch signal T0 'is output only during the period when the deceleration g is equal to or higher than the detection level G1 of the impact detection sensor 3, but the operation of the occupant restraint device is determined. After that, the latch signal T0 'may be output for a predetermined time. FIG. 7 shows a processing routine for making such a collision determination.
Note that the same steps as those in the processing routine shown in FIG. 3 are denoted by the same step numbers, and differences will be mainly described. After setting the operation determination signal T0 and the latch signal T0 'to high level in step S4 in accordance with the determination of the operation of the occupant restraint device, a timer for managing the output time of the latch signal T0' is started in step S5A,
In the following step S6A, it is determined whether or not the timer has expired. If the preset output time of the latch signal has elapsed, the process proceeds to step S7, and if not, the process returns to step S6A.

-Second Embodiment- FIG. 8 is a block diagram showing a configuration of a second embodiment. The second embodiment differs from the first embodiment shown in FIG. 2 only in part of the configuration of the control circuit. The same reference numerals are given to similar devices, and differences will be mainly described. explain. The control circuit 9 includes the collision determination unit 51 and the collision determination latch unit 5 described above.
2 and a sensor operation detection unit 53, a T1 output time control unit 91 and a start signal output unit 92 are provided. The T1 output time control unit 91 sets the output enable signal E of the activation signal T1 to high level when both the activation signal S and the latch signal T0 ′ are at high level, and outputs the output enable signal E when the activation signal T1 is output for the set time t. Set E to low level. When the activation signal S, the latch signal T0 ', and the output enable signal E all become high level, the activation signal output unit 92 outputs the activation signal T1.
Is output for a predetermined time t.

FIGS. 9 to 10 are flowcharts showing a control program executed by the microcomputer of the control circuit 9. The operation of the second embodiment will be described with reference to these flowcharts. The collision judgment processing routine of the collision judgment unit 51 and the collision judgment latch unit 52 is the same as the routine shown in FIG. 3, and the sensor operation detection routine of the sensor operation detection unit 53 is the same as the routine shown in FIG. Therefore, their description is omitted.

FIG. 9 shows a T1 output time control routine of the T1 output time control section 91. The microcomputer executes this control routine at a predetermined cycle. Step S3
In step 1, it is determined whether the activation signal S and the latch signal T0 'are both at the high level. If both are at the high level, the process proceeds to step S32; otherwise, the process ends. In step S32, the output enable signal E is set to a high level and output, and the process proceeds to step S33. In step S33, it is determined whether or not the activation signal T1 has been output continuously for a time t during which the occupant restraint device can be operated.
If the start signal T1 is output continuously for a time, step S3 is performed.
Proceed to step 4; otherwise, end the process. Step S
At 34, the output enable signal E is set to a low level and output, and the process ends. That is, in the T1 output time control routine, the output enable signal E is set to the high level when both the operation signal S and the latch signal T0 'are at the high level. However, when the activation signal T1 is continuously output for the predetermined time t, the operation is started. The output enable signal E is set to the low level regardless of the signal S and the latch signal T0 '. Note that the start signal T1
Is output by a counter (not shown) of the control circuit 9.

FIG. 10 shows a start signal output processing routine of the start signal output section 92. The microcomputer executes this processing routine at a predetermined cycle. Step S41
It is determined whether the activation signal S, the latch signal T0 ', and the output enable signal E are all at the high level. If all are at the high level, the process proceeds to step S42; otherwise, the process ends. In step S42, the activation signal T1 is set to low level and output, and the transistor 2 is turned on. At this time, since the contact of the impact detection sensor 3 is closed, the starting current I flows through the power supply circuit 4 → transistor 2 → squib 1 → impact detection sensor 3 → earth.

In step S43, a timer for managing the output time of the activation signal T1 is started, and in step S4
At 4, it is determined whether or not the timer has expired. In the above-described timer, the time t during which the occupant restraint device operates when the starting current I flows is set. Start signal T1
Is output for t time, the process proceeds to step S45, and if not, the process proceeds to step S46. In step S45, the activation signal T1 is set to a high level and output, and the transistor 2 is turned off. On the other hand, in step S46, it is determined whether or not the activation signal S, the latch signal T0 ', and the output enable signal E are all at the high level. If the level has changed, the process proceeds to step S45. That is, in the activation signal output processing routine, the operation signal S,
When the latch signal T0 ′ and the output enable signal E are all at a high level, the activation signal T1 is output for a predetermined time t.

FIG. 11 shows a case where the contact point of the impact detection sensor 3 chatters for some reason during a vehicle collision.
Operation signal S, deceleration g, output enable signal E, start signal T1
6 is a time chart showing changes in the starting current I and the starting current I.
At time t11, the impact of the collision exceeds the detection level G1 of the impact detection sensor 3, and the impact detection sensor 3 is activated, an operation signal S is output, and based on the deceleration g detected by the deceleration sensor 6 at time t12. It is assumed that the operation of the occupant restraint device is determined, and the operation determination signal T0 and the latch signal T0 ′ are output. At time t12, since both the activation signal S and the latch signal T0 'are at the high level, the output enable signal E goes to the high level, the activation signal T1 goes to the low level, and the transistor 2 is turned on. Thus, the starting current I starts to flow.

However, at time t13 before the output time of the activation signal T1 reaches the specified time t, if the contact of the shock detection sensor 3 is opened for some reason, the output enable signal E becomes low level, and the activation signal T1 becomes low. The level becomes high, and the transistor 2 is turned off. Therefore, the starting current I becomes almost zero. When the contact point of the impact detection sensor 3 is closed again at time t14, the output enable signal E goes high, the activation signal T1 goes low, and the transistor 2 conducts. Then, the starting current I
Begins to flow.

When the low-level start signal T1 is continuously output for the specified time t and the start current I continues to flow, the start signal T1 becomes high level at time t15, the transistor 2 is turned off, and the start current T1 is turned off. I becomes almost 0. At this time, the output enable signal E also goes low at the same time, and once the start signal T1 has been output continuously for the specified time t, the output enable signal E never goes high again. At time t16, the impact detection sensor 3
Even if the contact of opens and the operation signal S becomes low level,
The driving device does not respond to this change since the squib 1 has already passed the starting current I for the specified time t.

As described above, the time t required for the operation of the occupant restraint system while the closed circuit of the impact detection sensor 3 is detected is obtained.
Only the transistor 2 is turned on, so that the shock detection sensor 3 is turned on for the time t necessary for the operation of the occupant restraint system.
And the transistor 2 are simultaneously turned on, the starting power is supplied from the power supply circuit 4 to the squib 1, and the occupant restraint device operates. Further, once the starting power is supplied to the squib 1 for the time t necessary for the operation of the occupant restraint device, the transistor 2 is turned off, so that wasteful power is not consumed.

In each of the embodiments described above, an airbag is described as an example of the occupant restraint device. However, the present invention can be applied to other occupant restraint devices such as a seat belt.

In the configuration of the above embodiment, the power supply circuit 4
Is a power supply, a squib 1 is a starting element, an impact detection sensor 3 is a first switch, a transistor 2 is a second switch, a sensor operation detection unit 53 is a closed circuit detection unit, and a collision determination unit 51 is an operation necessity determination unit. From the collision determination latch 52
, The activation signal output unit 54, the activation signal output unit 92, and the T1 output time control unit 91 constitute the control unit.

[0030]

As described above, according to the first aspect of the present invention, the closing of the first switch is detected and the necessity of the operation of the occupant restraint device is determined based on the deceleration g of the vehicle. Output a signal. When the operation of the occupant restraint device is determined, the operation signal is held until the deceleration g of the vehicle becomes equal to or less than the predetermined impact G1, and when the operation signal is held, the closing of the first switch is detected. And the second switch are closed, so that the first switch and the second switch can be closed at the same time. The restraint device can be reliably operated. Also,
According to the second aspect of the invention, when the operation signal is held, the second switch is closed only for the time required for the operation of the occupant restraint device. Therefore, the second switch is closed for the time required for the operation of the occupant restraint device. The first switch and the second switch can be closed at the same time, and the occupant restraint device can be reliably operated while preventing unnecessary power consumption.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims.

FIG. 2 is a block diagram showing a configuration of the first embodiment.

FIG. 3 is a flowchart illustrating a collision determination processing routine according to the first embodiment.

FIG. 4 is a flowchart illustrating a sensor operation detection processing routine according to the first embodiment;

FIG. 5 is a flowchart illustrating a start signal output processing routine according to the first embodiment;

FIG. 6 is a diagram illustrating an operation signal S, a deceleration g, and a latch signal T0 ′ in a case where the operation of the impact detection sensor is delayed for some reason during a vehicle collision and the operation of the occupant restraint device is determined first based on the deceleration g. 5 is a time chart showing changes in a start signal T1 and a start current I;

FIG. 7 is a flowchart showing another collision determination processing routine of the first embodiment.

FIG. 8 is a block diagram showing a configuration of a second embodiment.

FIG. 9 is a flowchart illustrating a start signal output time control routine according to a second embodiment.

FIG. 10 is a flowchart illustrating a start signal output processing routine according to the second embodiment;

FIG. 11 is a time chart showing changes in the activation signal S, the deceleration g, the output enable signal E, the activation signal T1, and the activation current I when the contact point of the impact detection sensor chatters for some reason during a vehicle collision.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Squib 2 Transistor 3 Shock detection sensor 4 Power supply circuit 5, 9 Control circuit 41 Battery 42, 44 Diode 43 Boost circuit 45 Capacitor 51 Collision judging unit 52 Collision judging latch unit 53 Sensor operation detecting unit 54, 92 Starting signal output unit 6 Reduction Speed sensor 7,8 resistor 91 T1 output time control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60R 21/32

Claims (2)

(57) [Claims] 1. A and Starting device Ru actuates the occupant restraint system, a first switch for closing to detect a predetermined shock G1, the deceleration g of the vehicle detected by the deceleration detecting means
And a second switch that is opened and closed based on
A driving device for passenger restraint system startup power is supplied from a power source to the activation device when the first switch and said second switch is both closed, closing detecting means for detecting that said first switch is closed The operation of the occupant restraint system based on the deceleration g of the vehicle.
And an actuation necessity determining means for outputting an actuation signal, and the operation of the occupant restraint device is determined by the actuation necessity determining means.
Then, the deceleration g of the vehicle is equal to or less than the predetermined impact G1.
Actuation signal holding means for holding the actuation signal until it is below
And when the operation signal is held, the closed circuit detecting means
When the closed state of the first switch is detected by
A driving device for an occupant restraint device, comprising: control means for closing a switch . 2. The drive device for an occupant restraint device according to claim 1, wherein the control unit is configured to perform a control when the operation signal is held.
Driving device for an occupant restraint device according to claim closed to Rukoto the second switch for the time necessary for the operation of the occupant restraint system.