JP2000038110A - Vehicular occupant restraint/protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular occupant restraint/protection device that establishes comfortable seat-belt-tightened environments and protects occupants properly. SOLUTION: In seat belt slackening control, if the seat belt needs slackening (S136 is YES), it is wound to the limit (S138 is YES), and is then unreeled again until it has a preset slack (S139). If the seat belt is locked during the unreeling operation (S140 is YES), the lock is released and the seat belt is wound again until it has the preset slack (S137). When the seat belt is not locked until it is unreeled by a first predetermined length (S141 is YES), it is thereafter taken up by a second predetermined length (S142 and S143) so that it is no locked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle occupant restraint system mounted on a vehicle such as an automobile, and more particularly to a vehicle using an electric retractor for winding and pulling out a seat belt for protecting the occupant. The present invention relates to an occupant restraint device.

[0002]

2. Description of the Related Art A vehicle occupant restraint protection device having an electric retractor for winding and pulling out a seat belt has been conventionally known.

[0003] Such an occupant restraint protection device for a vehicle, for example, has a predetermined size when it is detected that the seat belt is not being worn and the seat belt is being worn, and when the seat belt is pulled out. The seat belt is wound up to a winding limit by a seat belt winding force, and thereafter, the seat belt is pulled out for a predetermined time by a seat belt pulling force of a predetermined size to give a predetermined slack to the seat belt. .

[0004]

However, in the above-described conventional vehicle occupant restraint system, when the seat belt is locked when the motor is rotated to the drawer side, the force acting on the seat belt rewind side. Because there is no
The seat belt remains locked, and there is a risk that the seat belt cannot be pulled out unless conditions for winding up the seat belt are newly established.

[0005] Here, the conditions under which the seat belt is wound up are determined to include a danger of a collision when a sudden brake is applied, when the seat belt is not worn, or when a collision of the host vehicle is predicted. Sometimes.

The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle occupant restraint protection device which can provide a comfortable seat belt wearing environment and can appropriately protect an occupant. And

[0007]

According to a first aspect of the present invention, there is provided a vehicle occupant restraint protection device comprising: an electric retractor for winding and pulling out a seat belt by a driving force of a motor; When the occupant wears the seat belt, the seat belt is wound up to a winding limit and then pulled out by a predetermined amount, so that the seat belt is provided with slack giving means for giving slack to the seat belt, and locking means for locking the drawer of the seat belt. In the vehicle occupant restraint protection device, when the seat belt is pulled out by the slack applying means and the seat belt is pulled out by the locking means, the slack applying operation by the slack applying means is performed again from the beginning. Control means for performing the control as described above.

According to the structure of the present invention, when the seat belt is pulled out by the slack applying means and the seat belt is pulled out by the locking means, control is performed such that the slack applying operation by the slack applying means is performed again from the beginning. As a result, the occupant is always given a predetermined slack, providing a comfortable seat belt wearing environment and appropriately protecting the occupant.

In the occupant restraint protection device for a vehicle according to the present invention, the control means preferably controls the motor to take up the seat belt to a take-up limit in the slack applying operation when the seat belt is worn, and thereafter, The seat belt may be pulled out by a first predetermined amount, and the seat belt may be controlled to be wound again by a second predetermined amount smaller than the first predetermined amount.

According to this configuration, even if it is not detected that the seat belt is locked, the seat belt is wound after the seat belt is pulled out, which causes the locking of the seat belt. Is canceled. Also, when the seat belt is not locked,
Since the slack of the difference between the first predetermined amount and the second predetermined amount is provided, it is possible to provide a comfortable seat belt wearing environment and appropriately protect the occupant.

In the vehicle occupant restraint protection device according to claim 1, when the seat belt is pulled out by the locking means is locked, the winding force of the seat belt rewinding performed again by the slack applying means is the same as the above. The take-up force of the seat belt taken up by the slack applying means before locking may be made larger than the take-up force.

According to this configuration, for example, it is determined that there is a risk of vehicle collision, and the seat belt is wound with a winding force larger than the winding force before locking, and thereafter, there is no danger of vehicle collision. When it is determined that the slack imparting operation is performed, the seat belt is slightly pulled out due to the elasticity of the occupant's body and the like because the winding force is changed from a large winding force to a smaller winding force. Here, when the seat belt is locked, if the seat belt is wound with a winding force larger than the winding force before the lock, the lock can be released and the slack applying operation can be performed again. And the occupant can be appropriately protected.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an electric retractor 100 provided in a vehicle occupant restraint protection apparatus according to an embodiment of the present invention.

The electric retractor 100 has a frame 1. A reel shaft 3 that winds up the seat belt is rotatably mounted on the frame 1, and locks the seat belt when the vehicle is subjected to a predetermined deceleration or when the seat belt is pulled out at a predetermined acceleration. A known seat belt lock mechanism 2 is fixed.

Next, the central axis 3a of the reel shaft 3 is connected to the central axis of the reel shaft pulley 5,
The reel shaft pulley 5 is connected to a DC motor pulley 6 via a power transmission belt 7.

A predetermined number of external teeth are formed on the outer circumference of the pulley 5 for the reel shaft and the pulley 6 for the DC motor, respectively, and a predetermined number of internal teeth are also formed on the inner circumference of the power transmission belt 7. The external teeth of the shaft pulley 5 and the DC motor pulley 6 mesh with the internal teeth of the power transmission belt 7 without excess or deficiency.

The central axis of the DC motor pulley 6 is connected to the DC motor 10. Accordingly, the rotation of the DC motor 10 is controlled via the DC motor pulley 6 by the reel shaft 3.
Is transmitted to

The DC motor 10 is fixed to the frame 1 at at least two points.
1 is connected to an MPU (Micro Processing Unit) 14. The DC motor drive unit 11 controls the DC motor 1 based on a PWM (pulse width modulation) signal from the MPU 14.
0 rotation is controlled.

FIG. 2 is a circuit diagram of the DC motor drive unit 11. Terminals P1 and P2 in FIG. 2 are input terminals for a PWM (pulse width modulation) signal output from the MPU 14, and a PWM signal of, for example, 20 kHz is input to the terminals P1 and P2. The terminals P3 and P4 are output terminals for current detection, the terminals P5 and P6 are output terminals for voltage detection, and the terminals P1 to P6 are connected to the MPU 14, respectively. The voltage V in FIG.
b is supplied to the DC motor 10, and the plurality of transistors, FETs, and the like in FIG. 2 are for driving the rotation of the DC motor 10 to rotate forward or reverse according to the PWM signal from the MPU 14.

A circuit C1 in FIG. 2 is a current detection circuit for detecting a current i flowing through the DC motor 10 from a current flowing through the resistor r1, and an interface circuit (hereinafter, referred to as an interface circuit) for removing a current fluctuation due to the influence of the PWM signal. 1) and IF2. MPU14 is IF1
And a voltage signal from IF2, and detects a current i flowing through the DC motor 10 based on the voltage signal.

The circuit C2 is a voltage measuring circuit for measuring a voltage between terminals applied to the DC motor 10, and IF3 and I3 are used to remove fluctuations in terminal voltage due to the influence of the PWM signal.
F4 is provided. The MPU 14 receives voltage signals from IF3 and IF4, respectively, and measures a terminal voltage applied to the DC motor 10 based on the voltage signals.

Each of IF1 to IF4 has a low-pass filter configuration including, for example, a resistor r2, a resistor r3 having a smaller resistance value than the resistor r2, and a capacitor c3, and has a cutoff frequency set to, for example, 20 Hz. As a result, the current detection circuit C 1 and the voltage measurement circuit C 2
4 is reduced to -60 dB, and hardly affects the current that is to be detected by the current detection circuit C1 or the voltage between terminals that is to be measured by the voltage measurement circuit C2.

Returning to FIG. 1, the MPU 14 is provided with timers 12, 13, and 15 for measuring time, detects whether or not the tongue of the seat belt is attached to the buckle, and determines whether or not the tongue of the seat belt is released from the buckle. A buckle connection presence / absence detection unit 16 for detecting whether or not the vehicle is running, a vehicle speed detection unit 17 for detecting the speed of the host vehicle, and a collision prediction detection unit for detecting whether there is a danger of collision and whether or not collision is inevitable. 1
8 respectively. Also, the MPU 14
A memory (not shown) for storing a control program is provided, and a vibration flag for vibrating the seat belt by alternately winding and pulling out the seat belt during the program is provided.

The buckle connection presence / absence detecting section 16 detects whether or not the tongue of the seat belt is attached to the buckle or detects whether or not the tongue of the seat belt is released from the buckle, and sends a corresponding control signal to the MPU 14. Output. The vehicle speed detector 17 detects the speed of the host vehicle and outputs a control signal corresponding to the detected speed to the MPU 14. The collision prediction detecting unit 18 detects whether there is a danger of a collision and whether or not it is inevitable to collide, and outputs a control signal corresponding to the collision to the MPU.
14 is output.

FIG. 3 is a diagram showing an example of a control program executed by the MPU 14.
14 is stored in a memory (not shown) provided in the memory 14.

First, the counter n used in the present control program is set to 0 (n ← 0) and the seat belt storage flag is reset (step S10), and it is determined that the tongue of the seat belt is attached to the buckle. It is determined whether or not the connection has been detected by the connection presence / absence detector 16 (step S11).

If the buckle connection detection unit 16 does not detect that the tongue of the seat belt is attached to the buckle, the timer 15 is started (step S17), and the voltage between the terminals of the DC motor 10 is applied to the seat belt. Is determined (step S1).
8) If the seat belt is pulled out, the timer 1
5 is stopped and cleared (step S19), the seat belt storage flag is set (step S20), and the process returns to step S11. On the other hand, when the seat belt is not pulled out, the timer 15 determines whether or not a predetermined time t1 (for example, 4 seconds) has elapsed (step S2).
1) If the predetermined time t1 has not elapsed, the process returns to step S18. If the predetermined time t1 has elapsed, the timer 15 is stopped and cleared (step S2).
2) It is determined whether the seat belt storage flag is set (step S23).

If the seatbelt storage flag is set, the seatbelt storage flag is reset (step S24), the seatbelt storage control is performed (step S25), and the process returns to step S11.

FIG. 4 is a flowchart showing an example of the seat belt storage control.

In the seat belt storage control, a PWM signal is input from the MPU 14 to the DC motor drive unit 11 to rotate the DC motor 10 to the seat belt winding side (step S251). It is determined whether or not the seat belt is at the winding limit (step S252). If the seat belt is not at the winding limit, the process returns to step S251. To end. Here, the seat belt take-up limit means that the DC motor 10 does not rotate to the seat belt take-up side.

Returning to FIG. 3, if the seat belt storage flag is not set in step S23, it is determined whether the value of the counter n is 5 or more (step S2).
6) If the value of the counter n is 5 or more, the process returns to step S11. If the value of the counter n is less than 5, the seat belt storage control is performed in the same manner as in step S25 (step S27). After the belt storage control ends,
The value of the counter n is incremented by 1 (step S2
8) Return to step S11.

If the buckle connection detection unit 16 detects that the tongue of the seat belt is attached to the buckle in step S11, the timer interrupt measured by the timer 12 is enabled (step S1).
2). By the interruption by the timer interruption, a timer interruption process described later is performed, for example, every 0.1 s.

FIG. 5 is a flowchart showing an example of the timer interrupt processing.

First, in the timer interrupt processing, the timer interrupt is invalidated (step S121). Next, it is determined whether or not the buckle connection presence / absence detection unit 16 has detected that the tongue of the seat belt is attached to the buckle (step S122).
If it is not detected that the tongue of the seat belt is attached to the buckle, the counter n is set to 0 (n ← 0) and the seat belt storage flag is reset (step S123), and the seat belt storage in step S25 is performed. Jump to control (step S124).

Next, in step S122, when the buckle connection presence / absence detection unit 16 detects that the tongue of the seat belt is attached to the buckle, the collision prediction detection unit 18 outputs a signal indicating that collision is inevitable. It is determined whether or not a signal has been input (step S125). If a signal indicating that collision is inevitable is input, the timer 1
3, a predetermined time t3 (for example, 4 s) measured by
By inputting the M signal to the DC motor drive unit 11,
The DC motor 10 is rotated to the seat belt winding side (step S126). Thereby, the occupant is properly protected in the event of a collision. Thereafter, the timer interrupt is enabled (step S127), and the process proceeds to step S13 (step S128).

If it is determined in step S125 that a signal indicating that collision is inevitable has not been input, it is determined whether a signal indicating danger of collision has been input from the collision prediction detecting unit 18 (step S125). S129) If a signal indicating that there is a danger of collision is input, a PWM signal is input to the DC motor drive unit 11 to rotate the DC motor 10 alternately to the seat belt pull-out side and the seat belt winding side. And vibrating the seat belt,
The fourteenth vibration flag is set (step S130).
The vibration frequency at this time is set to 1 Hz to 10 kHz, and vibration is given to the occupant so as to be easily perceived as an alarm. After that, the process returns to step S125 while keeping the vibration.

If it is determined in step S129 that a signal indicating a danger of collision has not been input, it is determined whether or not the seat belt has been vibrated by the vibration flag of the MPU 14 (step S131). If it is in the vibration state, the vibration flag is reset and the vibration is stopped (step S132), and the process proceeds to step S127. On the other hand, when the seat belt is not in the vibration state, the timer interrupt is enabled (step S13).
3) Return to where the timer interrupt occurred.

Returning to FIG. 3, next, a seat belt slack application control is performed in order to give the occupant a proper slack without giving a feeling of pressure (step S13).

FIG. 6 is a flowchart showing an example of the seat belt slack giving control.

First, it is determined whether or not the buckle connection presence / absence detection unit 16 has detected that the seat belt tongue has been attached to the buckle (step S135). If it is not detected that
On the other hand, if this control is finished, and the buckle connection presence / absence detection unit 16 detects that the tongue of the seat belt is attached to the buckle, it is determined whether or not it is necessary to provide the seat belt with a slack (step). S136). Here, the case where it is necessary to impart the seat belt slack is a case where there is a change from the regular seat belt position. For example, (1) braking is performed during traveling at a predetermined vehicle speed or higher, and thereafter, the vehicle speed is reduced. (2) When the collision prediction detection unit 18 detects that there is a danger of a collision, and thereafter, when it is detected that there is no danger of a collision, (3) This corresponds to, for example, a case where the occupant pulls out the seat belt, and thereafter, the seat belt can be wound up. If it is determined in step S136 that the seat belt is not slackened, the control is terminated. If the seatbelt is slackened, the PWM signal is input from the MPU 14 to the DC motor driving unit 11 if the seatbelt slack is required. Then, the DC motor 10 is rotated to the seat belt winding side (step S137), and it is determined whether or not the seat belt is at the winding limit based on the current flowing through the DC motor 10 (step S138). Thereby, the improper slack of the seat belt is once completely removed.

If it is determined in step S138 that the seat belt is not at the winding limit, the process returns to step S137. If the seat belt is at the winding limit, the PWM signal from the MPU 14 is supplied from the MPU 14 to give a predetermined slack. By inputting to the drive unit 11, the DC motor 1
0 to the seat belt withdrawal side (step S
139), it is determined whether or not the seat belt withdrawal is locked by the seat belt lock mechanism 2 (step S140). Here, when the fluctuation of the voltage between the terminals of the DC motor 10 when the DC motor 10 is rotated to the side where the seat belt is pulled out is equal to or less than a predetermined value, it is determined that the seat belt drawer is locked. Note that when the current flowing through the DC motor 10 is equal to or greater than a predetermined value or when the variation in the current flowing through the DC motor 10 is equal to or less than the predetermined value, it may be determined that the seat belt drawer is locked.

If it is determined in step S140 that the seat belt has been locked, the lock is released, and the flow returns to step S137 to give a predetermined slack again. At this time, the winding force of the seat belt winding performed in step S137 is determined when it is determined that the seat belt needs to be given slack (YE in step S136).
The force is larger than the winding force of S). This is because the lock cannot be released unless such a winding force is used.

When the seat belt is pulled out and locked, for example, it is determined that there is a risk of vehicle collision, and the seat belt is wound with a winding force larger than the winding force before locking. When it is determined that there is no danger of a vehicle collision and the slack imparting operation is performed, that is, when it is determined that the seat belt needs to be slack imparted, the winding force changes from a large winding force to a smaller winding force. The seat belt may be slightly pulled out due to the elasticity of the body of the user, and the seat belt may be locked. In such a case, if the seat belt is wound with a winding force larger than the winding force before locking as described above, the lock can be released and the slack applying operation can be performed again.

If it is determined in step S140 that the pullout of the seat belt is not locked, the DC motor 1
It is determined whether or not the seat belt withdrawal amount has reached the first predetermined amount (for example, 10 cm) from the terminal voltage of 0 (step S141).

If the withdrawal amount of the seat belt has not reached the first predetermined amount, the flow returns to step S139 to continue withdrawal, while if the withdrawal amount of the seat belt has reached the first predetermined amount, Assuming that it was not normally detected whether or not the seat belt drawer was locked, the PWM signal was again input from the MPU 14 to the DC motor drive unit 11 for the purpose of insurance, so that the DC motor 10 was seated. The belt is rotated to the winding side (step S142).

Next, based on the voltage between the terminals of the DC motor 10, the winding amount of the seat belt is adjusted to a second predetermined amount (for example, 5c
m) is determined (step S143). If the seat belt retracting amount has not reached the second predetermined amount, the process returns to step S142, while the seat belt retracting amount has reached the second predetermined amount. When the predetermined amount has been reached, this control ends.

Returning to FIG. 3, it is next determined whether or not the seat belt has been pulled out based on the voltage between the terminals of the DC motor 10 (step S14). If the seat belt has not been pulled out, the determination is repeated. On the other hand, when the seat belt is pulled out, it is determined whether or not the seat belt pull-out is completed based on whether or not the voltage between the terminals of the DC motor 10 is equal to or less than a predetermined value (for example, 0.3 V) (step). S15). If the seat belt has not been pulled out, the determination is repeated. If the seat belt has been pulled out, the vehicle speed v is determined to be a predetermined value from a signal corresponding to the vehicle speed v input from the vehicle speed detection unit 17. It is determined whether it is larger than v1 (for example, 10 km / h) (step S16).

When the vehicle speed v is equal to or lower than the predetermined value v1, the determination is repeated. When the vehicle speed v is higher than the predetermined value v1, the flow returns to the seat belt slack provision control in step S13. Thereby, for example, when the vehicle is slowly backing for parking, the reel shaft does not rotate forward,
The seat belt will not be wound up to the winding limit while the occupant is looking backward.

As described above, according to the present embodiment,
In the seat belt slack provision control (FIG. 6), when it is necessary to provide the seat belt slack (step S136).
YES at step S138), the seat belt is wound up to the winding limit (YES at step S138), and then the seat belt is pulled out to give a predetermined slack (step S13).
9) If the seat belt is locked during withdrawal (YES in step S140), the seat belt is wound up to release the lock and give a predetermined slack again (step S137). If the seat belt is not locked, the seat belt is wound up by a second predetermined amount so that the seat belt is not locked after the seat belt withdrawal amount reaches the first predetermined amount (step S142, Step S143) The occupant is configured to be always given a predetermined slack and is configured to release an unnecessary seat belt lock. Therefore, the vehicle occupant restraint protection device according to the present embodiment can provide a comfortable seat belt wearing environment and appropriately protect the occupant.

[0051]

As described above in detail, according to the vehicle occupant restraint protection device of the first aspect, when the seat belt is pulled out by the slack applying means and the draw-out of the seat belt is locked by the locking means, Since the slack imparting means is controlled to perform the slack imparting operation again from the beginning, the occupant is always given a predetermined slack, thereby providing a comfortable seat belt wearing environment and appropriately protecting the occupant.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an electric retractor 100 provided in a vehicle occupant restraint protection device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a DC motor driving unit 11;

FIG. 3 is a diagram illustrating an example of a control program executed by an MPU 14;

FIG. 4 is a flowchart illustrating an example of seat belt storage control.

FIG. 5 is a flowchart illustrating an example of a timer interrupt process.

FIG. 6 is a flowchart illustrating an example of seat belt slack imparting control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Frame 2 Seat belt lock mechanism (locking means) 3 Reel shaft 5 Reel shaft pulley 6 DC motor pulley 7 Power transmission belt 10 DC motor (slack applying means) 11 DC motor drive unit 14 MPU (slack applying means, control means) 16) buckle connection presence / absence detection unit 17 vehicle speed detection unit 100 electric retractor

Claims (1)

[Claims] 1. An electric retractor for winding and pulling out a seat belt by a driving force of a motor, and by pulling out a predetermined amount after winding the seat belt to a winding limit when an occupant wears the seat belt. A slack imparting means for imparting slack to the seat belt,
A vehicle occupant restraint protection device comprising: a lock unit that locks the seat belt withdrawal. When the seat belt is pulled out by the slack imparting unit and the seat belt withdrawal is locked by the lock unit, the seat belt is locked again. An occupant restraint protection device for a vehicle, further comprising control means for controlling the slack imparting means to perform the slack imparting operation from the beginning.