JPH11278215A - Occupant constraining and protecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant constraining and protecting device for a vehicle to provide comfortable seat belt mounting environment by approximately coinciding containing operation of a seat belt with the intention of an occupant. SOLUTION: After pull-out assist of a seat belt is started, it is discriminated (steps S35-S42), based on a change amount Δv (Δv=|Vk -Vk-1 |) of the interterminal voltage Vk of a DC motor with the prescribed time interval (10 ms), whether or not the seat belt is pulled out by an occupant. When the seat belt is not pulled out by the occupant (YES at the step S41), until a time (j) is increased to a value higher than 200, namely, until 2s (=10 ms×200) elapses starting from first discrimination, discrimination (step S43) of whether it is discriminated whether it is detected by a buckle connection presence detecting part that discrimination and mounting of the tongue of the seat belt on the buckle are effected is repeated.

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 Conventionally, for example, the following is known as a vehicle occupant restraint protection device having an electric retractor for pulling out or winding up a seat belt. That is,
When the electric retractor pulls out the seat belt, the operation is performed based on the sum of the pulling force of the seat belt by the occupant and the pulling force of the seat belt by the driving force of the DC motor, and the seat belt is not pulled out only by the driving force of the DC motor. Like that.

[0003] The electric retractor is operated after a predetermined time has passed since the seat belt was pulled out by the occupant.
When it is detected that the seat belt is not worn, the seat belt is wound up. Here, the predetermined time is a time required at least from the time when the occupant pulls out the seat belt to the time whether or not the seat belt is worn.

FIG. 6 is a flowchart for explaining the details of the conventional seat belt pull-out control. The seat belt withdrawal control is a part of the main control performed by the MPU included in the vehicle occupant restraint protection device.

First, in step S61, it is determined whether or not the buckle connection presence / absence detecting section detects that the seat belt tongue is attached to the buckle, and it is detected that the seat belt tongue is attached to the buckle. If it is determined that the seat belt has been pulled out, a control signal for turning off the DC motor is output to the DC motor drive unit (step S69), and the control ends. On the other hand, when it is not detected that the tongue of the seat belt is attached to the buckle, the drive of the DC motor is temporarily turned off to assist in pulling out the seat belt.
The control signal for performing the FF is output to the DC motor drive unit (step S62).

Next, the voltage between the terminals of the DC motor and the polarity of the voltage between the terminals are measured by a circuit for detecting the voltage between the terminals of the DC motor (step S63). In addition, it is determined whether or not the polarity of the inter-terminal voltage is the polarity corresponding to the seat belt withdrawal side (step S64). Here, the case where the voltage between the terminals of the DC motor is 0.3 V or more and the polarity of the voltage between the terminals is the polarity corresponding to the pull-out side of the seat belt is, for example, the case where the occupant pulls out the seat belt lightly. .

If it is determined in step S64 that the voltage between the terminals of the DC motor is not equal to or higher than 0.3 V or the polarity of the voltage between the terminals is not the polarity corresponding to the side where the seat belt is pulled out, the process returns to step S63, When the voltage between the terminals of the motor is 0.3 V or more, and the polarity of the voltage between the terminals is the polarity corresponding to the side where the seat belt is pulled out, the DC motor is used to rotate the reel shaft to the side where the seat belt is pulled out. The control signal to be driven is output to the DC motor drive unit (step S65). Thereby, the seat belt can be easily pulled out.

Next, in step S66, it is determined whether or not the buckle connection presence / absence detecting section detects that the tongue of the seat belt is attached to the buckle, and it is detected that the tongue of the seat belt is attached to the buckle. If so, the process proceeds to step S69 described above. On the other hand, when it is not detected that the tongue of the seat belt is attached to the buckle, in step S67, for example, 7 seconds have elapsed since the electric signal for driving the DC motor was output to the DC motor driving unit. It is determined whether or not.

In step S67, if seven seconds have not elapsed, the process returns to step S65. If seven seconds have elapsed, the seat belt is pulled out, but the tongue of the seat belt is not attached to the buckle. Since the seat belt remains slack, a control signal for turning off the drive of the DC motor is output to the DC motor drive unit (step S6).
8) A known seat belt storage control is performed.

In the above conventional control, it is detected that the seat belt is not worn after the seat belt is pulled out by the occupant, and the seat belt storage control is not performed until at least seven seconds have elapsed.

[0011]

For this reason, if the user pulls out the seat belt without intending to wear it,
Since the seat belt is not wound up until a predetermined time has elapsed, the intention of the occupant who wants the seat belt to be retracted quickly differs from the actual retracting operation of the seat belt.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a vehicle occupant restraint protection device capable of providing a comfortable seat belt wearing environment by bringing a seat belt retracting operation closer to an occupant's intention. The purpose is to provide.

[0013]

According to a first aspect of the present invention, there is provided an occupant restraint protection system for a vehicle, comprising: an electric retractor for winding at least a seat belt; a driving unit for driving the electric retractor; In a vehicle occupant restraint protection device comprising: a drawer stop detecting unit configured to detect that the seat belt has been pulled out, when the stop of the seat belt is detected by the drawer stop detecting unit, It is characterized by comprising control means for controlling the driving of the driving means.

According to the construction of the present invention, when the stop of the seat belt withdrawal is detected by the withdrawal stop detecting means, the driving of the driving means is controlled, so that the user pulls out the seat belt without intending to wear it. in case of,
By driving the electric retractor by the driving means, the seat belt can be quickly wound up, and a comfortable seat belt wearing environment can be provided by bringing the retracting operation of the seat belt closer to the intention of the occupant.

[0015] The draw-out stop detecting means is based on at least one of a voltage applied to the driving means, an amount of change in the voltage applied to the driving means, a current applied to the driving means, and an amount of change in the current applied to the driving means. It may be configured to detect that the withdrawal of the seat belt has stopped.

According to this configuration, it is possible to electrically accurately detect that the withdrawal of the seat belt has stopped.

[0017]

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

FIG. 1 is a view 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. An urging force applying means such as a spiral spring is formed inside the reel shaft pulley 5, and the urging force always acts in the direction of winding the seat belt.

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 center axis of the DC motor pulley 6 is connected to the DC motor 10. Therefore, the rotation of the DC motor 10 is transmitted to the reel shaft 3 via the DC motor pulley 6.

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 rotation of the DC motor 10 based on a control signal from the MPU 14.

FIG. 2 is a circuit diagram of the DC motor drive unit 11. A circuit C1 in FIG. 2 is a current detection circuit that detects a current i flowing through the DC motor 10 from a current flowing through the resistor r1, and a circuit C2 is a voltage measurement circuit that measures a voltage v between terminals of the DC motor 10. The battery voltage Vb in FIG. 2 supplies a power supply voltage to the DC motor 10, and a plurality of transistors and FETs are used to drive the rotation of the DC motor 10 forward or reverse according to a control signal from the MPU 14. is there.

Referring back to FIG. 1, the MPU 14 is connected to a buckle connection presence / absence detector 16 for detecting whether or not the tongue of the seat belt is attached to the buckle and for detecting whether or not the tongue of the seat belt is released from the buckle. Have been. Further, the MPU 14 includes a timer 15 for measuring time. The MPU 14 determines whether or not the seat belt is pulled out based on the voltage v between the terminals of the DC motor 10, and determines whether or not the winding of the seat belt is completed based on the current i flowing through the DC motor 10.

When the MPU 14 determines that the seat belt has been pulled out, the MPU 14 outputs a control signal for driving the DC motor 10 to the DC motor drive unit 11 to rotate the reel shaft 3 to the side where the seat belt is pulled out. As a result, the seat belt pull-out assist is performed. here,
The seat belt is pulled out based on the sum of the seat belt pulling force by the occupant and the seat belt pulling force by the driving force of the DC motor 10. The electric retractor 100 is configured so that the seat belt is not pulled out only by the driving force of the DC motor 10.

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.

FIGS. 3 and 4 are flowcharts for explaining the details of the seat belt pull-out control performed by the MPU 14 when pulling out the seat belt. Note that the seat belt withdrawal control is a part of the main control performed by the MPU 14.

First, the DC motor 10 is controlled by the voltage measuring circuit C2.
The terminal voltage v of the DC motor 10 when the terminals are open is measured (step S31), and the measured terminal voltage v of the DC motor 10 is a predetermined value, for example,
It is determined whether the voltage is greater than 0.3 V (step S3).
2).

If the inter-terminal voltage v of the DC motor 10 is equal to or less than the predetermined value (0.3 V), the process returns to step S31, while the inter-terminal voltage v of the DC motor 10 is set to the predetermined value (0.3 V).
V), a control signal for driving the DC motor 10 to rotate the reel shaft 3 to the side where the seat belt is pulled out is output to the DC motor drive unit 11 (step S33). As a result, the seat belt pull-out assist is performed.

FIG. 5 is a diagram showing an example of the relationship between the voltage v between the terminals of the DC motor 10 and the elapsed time.

Here, the voltage v between the terminals of the DC motor 10 is represented by v _k (k = 0, 1, 2,...), And the variation Δv of the voltage v between the terminals of the DC motor 10 is | v _k −v _{k− 1} | still,
The unit time (the time corresponding to 1 in the figure) is, for example, 10 ms.
And

At time a in the figure, the voltage v _k between the terminals of the DC motor 10 changes to a waveform state. This is because the DC motor 10 attempts to drive against the urging force of the spiral spring or the like when the occupant pulls out the seat belt. On the other hand, at time b in the figure, the DC motor 10
_Has a constant value and does not fluctuate. This means that the occupant does not pull out the seat belt,
This is because the DC motor 10 is not trying to drive.

Returning to FIG. 3, the subscript counter k for the time j and the voltage v _k between the terminals of the DC motor 10 is reset (j ←
0, k ← 0) (step S34), and the voltage measurement circuit C2 measures the terminal voltage v _k of the DC motor 10 (step S35).

Next, it is determined whether or not the subscript counter k of the terminal voltage v _k of the DC motor 10 is 0 (step S).
36) If the subscript counter _k of the inter-terminal voltage v _k of the DC motor 10 is 0, the subscript counter k is incremented by 1 (k ← k + 1) (step S37). Thereafter, time adjustment is performed at predetermined time (10 ms) intervals to measure the inter-terminal voltage v _k of the DC motor 10 (step S38), and the process returns to step S35. Step S36 above
The subscript counter k of the voltage v _k between the terminals of the DC motor 10
If but not 0, the predetermined time (10 ms) the variation of terminal voltage v _k per _{Δv (Δv = | v k -v} k-1 |) is calculated (steps S39), 1 the index counter k Increment (k ← k + 1) (step S40).

Next, the change amount Δv (Δv = |) of the inter-terminal voltage v _k of the DC motor 10 calculated in step S39.
v _k -v _k-1 |) is a predetermined value, for example, to determine whether 0.1V smaller (step S41).

In step S41, the variation Δv of the voltage v _k between the terminals of the DC motor 10 (Δv = | v _k −v _k−1 |)
Is greater than or equal to a predetermined value (0.1 V), that is, when the occupant pulls out the seat belt, the time j
Is reset (j ← 0) (step S42), and it is determined whether the buckle connection presence / absence detecting unit 16 has detected that the tongue of the seat belt is attached to the buckle (step S43). If it is not detected by the buckle connection detection unit 16, the process returns to step S 38. If it is detected by the buckle connection detection unit 16, a control signal for stopping the driving of the DC motor 10 is sent to the DC motor drive. Output to the unit 11 (step S44)
This control ends.

In step S41, the variation Δv of the voltage v _k between the terminals of the DC motor 10 (Δv = | v _k −v _k−1 |)
Is smaller than a predetermined value (0.1 V), that is, when the seat belt is not pulled out by the occupant,
The time j is incremented by 1 (j ← j + 1) (step S45), and it is determined whether the time j is greater than a predetermined value, for example, 200 (step S46). Time j is 200
In the following cases, while the determination in step S43 is performed, if the time j is greater than 200, the time j is reset (j ← 0) (step S47), and the DC motor 10
Is output to the DC motor drive unit 11 (step S48), and the process proceeds to the seat belt storage control. Since the seat belt storage control is publicly known, its description is omitted.

As described above, according to the embodiment of the present invention, the withdrawal assistance of the seat belt is started (step S).
33), the change amount Δv (Δv = | v _k ) of the inter-terminal voltage v _k of the DC motor 10 at predetermined time (10 ms) intervals.
−v _k−1 |), it is determined whether or not the occupant has pulled out the seat belt (steps S35 to S41). If the occupant has not pulled out the seat belt (step S35). Step S
At 41, YES is determined until the time j becomes greater than 200, that is, 2s (= 10
Until the elapse of (ms × 200), the above determination and the determination of 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 S43) are repeated. After a lapse of 2 s (= 10 ms × 200) from the start, the control signal for stopping the drive of the DC motor 10 is output to the DC motor drive unit 11 (step S48), and the seat belt storage control is performed. If the user pulls out the belt without intending to wear it, the user can quickly wind up the seat belt, and a comfortable seat belt wearing environment can be provided by bringing the retracting operation of the seat belt closer to the intention of the occupant.

In the present embodiment, the change amount Δv of the inter-terminal voltage v _k of the DC motor 10 (Δv = | v _k −v _k−1 |)
It has been determined whether the occupant has pulled out the seat belt or not, but the magnitude of the terminal voltage v _k of the DC motor 10, the magnitude of the current i flowing through the DC motor 10, or Even if it is determined whether or not the occupant has pulled out the seat belt by using the change amount Δi of the current i flowing in the DC motor 10, the same effect as that of the present invention can be obtained.

[0042]

As described in detail above, according to the vehicle occupant restraint protection device of the first aspect, when the stop of the seat belt withdrawal is detected by the withdrawal stop detecting means, the driving of the driving means is performed. If the seat belt is pulled out without intending to wear it, the electric retractor can be driven by the driving means, and the seat belt can be quickly wound up, and the retracting operation of the seat belt can be made closer to the intention of the occupant. Thus, a comfortable seat belt wearing environment can be provided.

[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 flowchart illustrating details of seat belt pull-out control performed by an MPU when pulling out a seat belt.

FIG. 4 is a flowchart illustrating details of seat belt pull-out control performed by an MPU when pulling out a seat belt.

FIG. 5 is a diagram illustrating an example of a relationship between a terminal voltage v of the DC motor 10 and an elapsed time.

FIG. 6 is a flowchart illustrating details of a conventional seat belt withdrawal control.

[Explanation of symbols]

 Reference Signs List 1 frame 2 seat belt lock mechanism 3 reel shaft 5 reel shaft pulley 6 DC motor pulley 7 power transmission belt 10 DC motor (drive unit) 11 DC motor drive unit (drive unit) 14 MPU (control unit, pull-out stop detection unit) ) 100 Electric retractor

Claims (1)

[Claims] 1. A vehicle comprising at least an electric retractor for winding up a seat belt, a driving means for driving the electric retractor, and a drawer stop detecting means for detecting that the seat belt has been pulled out. An occupant restraint protection device, comprising: control means for controlling driving of the driving means when the stop of the seat belt withdrawal is detected by the pull-out stop detecting means. apparatus.