JP2001163185A - Seat belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance safety of a seat belt device with an impact absorbing (EA) mechanism. SOLUTION: At the stage of the possibility of collision, looseness of a seatbelt (302) is removed in advance, and after the collision, an occupant is restrained to a seat by an explosive seat take-up device 104. In addition, a load at a position where the occupant is brought into contact with the seat belt is limited by an energy absorbing mechanism (EA). Even if the occupant is moved by the EA mechanism, since the looseness of the belt is removed, the occupant is not moved to the area of an airbag 500 when the it is being expanded, and the head part of the occupant can be prevented from hitting the airbag in the middle of expansion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat belt device for effectively restraining an occupant in a seat in the event of a vehicle collision, and more particularly to improving the performance of protecting the occupant after restraining. The present invention relates to a seat belt device.

[0002]

2. Description of the Related Art Conventionally, in a seat belt retractor (retractor) for securely holding a vehicle occupant or the like in a seat, the belt retractor is controlled by inertial sensing means which responds to sudden acceleration, collision or deceleration. 2. Description of the Related Art An emergency lock retractor that includes an emergency lock mechanism for physically locking and effectively and safely restrains an occupant has been used. An example of such an emergency lock type belt winding device is disclosed in
No. 9024, Japanese Patent Publication No. 59-21624 and Jihei 2-
There is a seat belt winding device disclosed in Japanese Patent No. 45088. Further, there is also a seat belt device in which an explosive-type belt winding device (pretensioner) is provided so that slack of the belt is instantaneously removed at the time of collision.

[0003] However, when the seat belt is completely locked, when the vehicle collides, inertia force acts on the occupant in the collision direction, so that the occupant restrained by the seat belt is pressed against the seat belt. There is a risk that the chest may be damaged. For this reason, when the belt tension exceeds a predetermined value, a seat belt device provided with an EA (energy absorption) mechanism has been proposed, in which the seat belt is pulled out from the belt winding device to reduce the impact received by the occupant. Have been.

Further, when the occupant moves in the collision direction due to the impact of the collision, a secondary collision that collides with the steering wheel or the internal structure of the vehicle also occurs. Is done.

[0005]

However, when the occupant is wearing thick clothes, the amount of pulling out of the belt increases. If it takes time for the pretensioner to operate and the occupant to be restrained by the required seatbelt tension, an inertial force acting on the occupant during the winding of the belt acts on the seatbelt. When the withdrawal load applied to the seat belt exceeds a predetermined value, the EA mechanism operates to extend the seat belt. As a result, the occupant moves in the collision direction, and the deployed airbag may hit the head or the like.
Further, even when the determination of the collision detection is delayed, the occupant may similarly move, enter the deployment range of the airbag, and the deployed airbag may hit the head or the like at the deployment speed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a seat belt device provided with an EA mechanism, wherein the movement of an occupant is further reduced.

It is another object of the present invention to provide a seat belt device provided with an EA mechanism, in which a head of an occupant is unlikely to hit an airbag being deployed.

[0008]

To achieve the above object, a seat belt device according to the present invention comprises a seat belt for restraining an occupant to a seat and a first belt for varying the tension of the seat belt.
And second tension variable means, collision prediction means for predicting a collision of a vehicle and outputting a collision prediction signal according to the possibility of collision, and collision detection means for detecting a collision of the vehicle and outputting a collision detection signal An airbag device that deploys an airbag based on the collision detection signal to prevent a secondary collision of an occupant; and the first airbag device based on the collision prediction signal and the collision detection signal.
Control means for controlling the second tension varying means; and tension limiting means for limiting the tension so that the tension of the seat belt does not exceed a predetermined value.

With this configuration, the first tension varying means removes excess slack in the seat belt before the collision, and the second tension before the inertia force exerted by the occupant on the seat belt during the collision. The belt winding is completed by the tension varying means. For this reason, the tension limiting means (EA mechanism)
It is possible to prevent the occupant from moving more than a desirable amount in the collision direction even if is activated, and it is possible to avoid hitting the occupant's head or the like due to the deployment of the airbag.

[0010] Preferably, the first tension varying means includes:
The motor drives the seat belt to the retracting side or the delivering side, the second tension varying means instantly retracts the seat belt by the explosive force of the explosive, and the tension limiting means causes the metal rod to be pulled out by pulling out the seat belt. Twist to suppress increase in belt tension.

Preferably, the first and second tension changing means and the tension limiting means are provided in a belt winding device for winding one end of a seat belt.

Preferably, the first tension varying means and the tension limiting means are provided in a belt winding device for winding one end of a seat belt, and the second tension varying means is provided in a buckle portion.

[0013] Preferably, the second tension varying means and the tension limiting means are provided in a belt winding device, and the belt winding device is provided with forcible locking means capable of electrically locking a seat belt withdrawal. The first tension varying means is provided on a buckle portion. Preferably, the first tension varying means and the tension limiting means are provided on a belt winding device, and the second tension varying means comprises a seat belt. Is provided on a lap belt fixing portion for fixing the other end to the vehicle body.

[0014] Preferably, the second tension varying means and the tension limiting means are provided in a belt winding device, and the belt winding device is provided with a forcible locking means capable of electrically locking a seat belt withdrawal. The first tension varying means is provided in the lap belt fixing portion.

Preferably, the tension limiting means and the electrically lockable forcible locking means are provided in a belt winding device, the first tension varying means is provided in a buckle portion, and the second tension varying means is provided in a buckle portion. It is provided on the lap belt fixing part.

Preferably, the tension limiting means and the forcible locking means are provided on a belt winding device, the second tension varying means is provided on a buckle part, and the first tension varying means is a lap belt fixing part. Is provided.

Preferably, the tension limiting means and the forcible locking means are provided in a belt winding device, and the first and second variable tension means are provided in a lap belt fixing portion.

[0018] Preferably, the belt winding device is fixed to a seat. The lap belt is provided on the seat.

Preferably, the tension limiting means includes a torsion shaft and a magnetic fluid.

[0020]

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

FIG. 1 shows an example of a seat belt device for a vehicle. The seat belt device is an electric winding device 10 that winds a seat belt 302 that restrains an occupant to a seat 301.
0, a through anchor 303 that folds the seat belt 302 in the vicinity of the occupant's shoulder, a tongue plate 305 that penetrates the seat belt and engages with a buckle 304 arranged on the waist, and an anchor that fixes the end of the seat belt 302 to the vehicle body. 30
6, a switch 307 built in the buckle for detecting belt wearing, a control unit 200 (not shown) for controlling the motor of the belt winding device 100, a collision prediction unit 401 (not shown) for predicting a vehicle collision, It is configured by a collision detection unit 402 (not shown) and the like. An airbag device 500 is provided at the center of the handle. An airbag device is also provided on the dashboard and the door of the passenger seat (not shown).

FIG. 2 is an explanatory view schematically illustrating the configuration of the electric winding device 100. In the figure, the electric winding device 100 includes a frame 101. The frame 101 is provided with a reel 103 around which a seat belt 302 is wound, and a reel shaft 103a which is connected to the left end side of the reel 103 and serves as a central axis of rotation of the reel. At the right end of the reel shaft 103a, a seat belt lock mechanism 102, which will be described later, for locking the seat belt 302 from being pulled out, is provided. The seat belt lock mechanism 102 performs a VSI operation that locks the pullout of the belt when a predetermined deceleration acts on the vehicle, and a WSI operation that locks the pullout of the seat belt 302 when the seat belt 302 is pulled out at a predetermined acceleration. And The lock mechanism 102 includes the lock mechanism 10.
2 is further provided with an electromagnetic actuator 112 described later for forcibly operating the actuator 2 in response to a command signal. The operation of the electromagnetic actuator 112 is controlled by an output of a control unit 200 described later. Seat belt lock mechanism 102
Is configured so that the seat belt 302 can be wound by the electric motor 110 even when the seat belt 302 is pulled out.

The above-mentioned reel shaft 103a is a torsion shaft and also plays a role as an energy absorbing (EA) means. That is, the seat belt lock mechanism 102
When the seat belt is pulled out with a strong force and the reel 103 rotates with the right end of the reel shaft 103a (torsion shaft) locked by the reel shaft 103a, the reel shaft 103a
It is twisted around its axis and plastically deforms. Thereby,
The seat belt 302 is pulled out, and the impact energy acting on the occupant's body is absorbed by the seat belt 302.

The pretensioner 104 is operated via the control unit 200 by the output of a collision detector (not shown), rotates the reel shaft 103a in the seat belt winding direction, and forcibly winds the seat belt to take the occupant. Restrain to seat. The pretensioner 104 is, for example, an explosive-type pretensioner, and controls a gas generator, a cylinder that seals gas generated from the gas generator, a piston that moves in the cylinder by gas pressure, and movement of the piston through a clutch mechanism. Of the reel shaft 103a.

Pulley 10 fixed to reel shaft 103a
5 is a DC motor 11 via a power transmission belt 107.
It is connected to a pulley 106 fixed to the 0 axis. A predetermined number of external teeth are formed on the outer circumference of each of the pulleys 105 and 106, and a predetermined number of internal teeth are also formed on the inner circumference of the belt 107. The tooth ridges of the pulley 105 for the reel shaft, the pulley 106 for the motor, and the belt 107 mesh with each other without excess and deficiency, and the rotation of the motor 110 is transmitted to the reel shaft 103a. The motor 110 is fixed to the frame 101 at at least two points, and operates by an output of the control unit 200.

As shown in FIG. 3, a potentiometer 111 provided at the leftmost end of the reel shaft 103a is provided with a resistor to which voltage is applied to both ends, and a reel shaft 103a.
and a slider interlocked with the rotation of a. Then, a voltage value corresponding to the rotation amount from the reference position of the reel shaft 103a is output to the control unit 200. This allows
For example, the belt withdrawal amount can be estimated. Further, the amount of slack of the belt can be estimated by comparing the voltage value of the belt with no slack with the voltage value of the belt withdrawn.

FIG. 4 is a functional block diagram illustrating a schematic configuration of the control unit 200. As shown in the figure, the control unit 200 is configured by a microcomputer system. The CPU 201 controls the operation of an electromagnetic actuator (for example, a solenoid) 112 that loads a control program or data held in the ROM 202 into a work area of the RAM 203 and forcibly operates the motor 110 and the seat belt lock mechanism 102.

The collision prediction unit 401 shown in FIG. 3 determines whether there is a possibility that a collision between the host vehicle and an obstacle such as a preceding vehicle may occur, and whether the collision can or cannot be avoided. For example, a non-contact distance sensor such as a laser radar, an ultrasonic sensor, or the like measures the distance between the vehicle and an obstacle at predetermined time intervals. The relative speed is calculated from the temporal change of this distance. Divide the distance by the relative speed to calculate the time to collision. If the collision time is equal to or shorter than a predetermined time T1, a collision prediction signal is output as a possibility of collision. This signal is supplied to the input interface 204 and turns on the “collision prediction flag” in a flag area (flag register) provided in the RAM 203. This causes the CPU 201 to start an interrupt process described later.

The output of the buckle switch 307 sets a flag in the flag area provided in the RAM 203 via the input interface 204 in accordance with the presence or absence of the belt.

The collision detection unit 402 detects an impact generated on the vehicle body at the time of a collision by an acceleration sensor, performs signal processing on the acceleration signal, and detects a collision based on the magnitude and rising waveform. This signal is supplied to the input interface 204 and turns on the "collision detection flag" in the flag area in the RAM 203. This causes the CPU 201 to start an interrupt process described later.

Although not shown, since it is not directly related to the present invention, the output voltage of the potentiometer 111 is set to A / A at a predetermined cycle by the input interface 204.
D conversion is performed. The input interface 204 has a built-in CPU and monitors the converted output voltage data. For example, the difference between the previous value and the current value of the output voltage data determines the rotation state of the shaft 103a, and the positive or negative difference between the previous value and the current value of the output voltage data determines whether the seat belt is pulled out. The flag is set in the flag area of the RAM 203. Also, the output voltage data is stored in the RAM by the DMA operation.
Writing is performed in the rotation amount area 203. The amount of change in the pull-out direction from the output voltage data when the belt is wound up corresponds to the amount of slack in the belt. This slack amount is written in the belt slack amount area 1 of the RAM 203.

The value of the current flowing through the motor 110 is detected as a voltage value corresponding to the current by a current detector CT provided in a motor drive circuit 206 described later. This voltage value is input to the input interface 204 at a predetermined cycle.
/ D converted and written into the motor current area in the RAM 203 by the DMA operation. Since the current of the motor 110 is related to the rotation torque of the motor, the rotation torque can be estimated from the load current value. The rotation torque of the motor 110 is the pulling force (tension) of the seat belt 302.

When a predetermined condition set in the control program is satisfied, the CPU 201 outputs a forward rotation instruction, a reverse rotation instruction, and a drive stop instruction of the motor 110 to the output interface 20.
Give 5 The output interface 205 generates gate signals G1 and G2 corresponding to these instructions, and supplies them to the motor drive circuit 206. G1 and G
2 to “H” and “L” respectively.
G1 and G2 are set to "L" and "H", respectively, and in response to the drive stop command, G1 and G2 are set to "L" and "L", respectively.

FIG. 5 is a circuit diagram showing a configuration example of a motor drive circuit. A transistor bridge circuit is formed by the four transistors of the PNP transistors Q1, Q2 and the NPN transistors Q3, Q4. Transistor Q
1, the emitters of Q2 are connected to each other, and
Is supplied. The emitters of the transistors Q3 and Q4 are also connected, and a ground potential is supplied to the connection point.

As described above, the level of each emitter output current of the transistors Q 3 and Q 4 is detected by the current detector CT, and a level detection signal is sent to the input interface 204. The input interface 204 performs A / D conversion of the level detection signal, and writes the converted signal into the belt tension area of the RAM 203 by a DMA operation. Since the value of the load current flowing through the motor is related to the torque, the seat belt tension F can be estimated from this.

The collector of the transistor Q1 and the collector of the transistor Q3 are connected via a diode D1. The collector of the transistor Q2 and the collector of the transistor Q4 are connected via a diode D2. The base of the transistor Q1 and the collector of the transistor Q4 are connected via a bias resistor R1. The base of the transistor Q2 and the collector of the transistor Q3 are connected via a bias resistor R2. A DC electric motor M is connected between the collectors of the transistors Q1 and Q2.

In such a configuration, the transistors Q3,
A forward rotation command signal (G1 = “H”, G2 =
When "L") is supplied from the output interface 205, the transistor Q3 is turned on and the transistor Q4 is turned off. The collector of the transistor Q3 is brought to the ground level by conduction, and the base of the transistor Q2 is biased to a low level (substantially the ground level) via the resistor R2 to make the transistor Q2 conductive. The collector of the transistor Q4 is substantially at the level of the power supply Vc, and the base of the transistor Q2 is biased to a high level via the resistor R1.
Is made non-conductive. As a result, a forward current path is formed by the path of the power supply Vc, the transistor Q2, the motor M, the diode D1, the transistor Q3, and the ground, and the motor M rotates in the direction of winding the seat belt.

When a reverse command signal (G1 = “L”, G2 = “H”) is supplied from the output interface 205 to each gate of the transistors Q3 and Q4, the transistor Q3 is turned off and the transistor Q4 is turned on. The collector of the transistor Q4 is at the ground level, and the base of the transistor Q1 is biased to a low level via the resistor R1 to make the transistor Q1 conductive. The collector of the transistor Q3 is substantially at the level of the power supply Vc, and the transistor Q3 is connected via the resistor R2.
The base of 2 is biased high, causing transistor Q2 to become non-conductive. As a result, the power supply Vc and the transistor Q
1. A current path in the opposite direction is formed by the path of the motor M, the diode D2, the transistor Q3, and the ground, and the motor M rotates in a direction to pull out the seat belt.

When a drive stop command signal (G1 = "L", G2 = "L") is supplied to the gates of the transistors Q3 and Q4 from the output interface 205, both the NPN type transistors Q3 and Q4 become non-conductive. Become. Transistor Q
When the transistor 3 changes from the conductive state to the non-conductive state, the transistor Q3
Collector rises from ground level to near power level,
The base of the transistor Q2 is biased to a high potential to shut off the transistor Q2. Similarly, when the transistor Q4 changes from the conductive state to the non-conductive state, the collector of the transistor Q4 rises from the ground level to substantially the power supply level, and the base of the transistor Q1 is biased to a high potential to shut off the transistor Q1. In this way, when the drive stop command is issued, each transistor constituting the bridge becomes non-conductive.

Returning to FIG. 4, when the condition for operating the forced lock of the seat belt lock mechanism 102 is satisfied, the CPU 201 issues a lock command signal (solenoid operation command).
Is given to the output interface 205. The operation command set in the flag register of the output interface 205 is
The power is amplified by the power amplifier 207 from a logical level signal to a level at which the solenoid can be driven, and is applied to the solenoid 112. When the solenoid operates, the actuator moves, and the lock mechanism 102 of the winding device 100 operates. When the seat belt lock mechanism 102 is activated, the seat belt lock mechanism 102 prevents the seat belt from being pulled out to prevent the belt from being loosened, but allows the seat belt to be wound.

FIG. 6 is a flowchart illustrating a control mode of the control unit 200. In this example, the operation of the motor that winds up the seat belt as the first tension varying means is controlled.

The CPU 201 periodically monitors the seatbelt wearing flag by executing the main program (S12). When the seatbelt wearing flag is on (S12; Yes), the CPU 201 determines whether or not there is a possibility of a collision based on whether or not the collision prediction flag is set (S14). If the flag is on (S14; Yes), the motor drive circuit 206 is operated to rotate the motor 110 as a slack removing means or a variable tension means in the belt winding direction to wind the webbing 302. Perform (S16). This removes some slack in the seat belt. For example, winding may be performed until the belt exceeds a predetermined tension or for a predetermined time. The tension can be determined by reading the sample value written in the current value area of the RAM 203. This step removes slack in the seat belt before the collision.

If the seat belt is not worn (S12; No) or the collision prediction flag is off (S14; No), the CPU 201 does not need to remove the slack in the seat belt, and therefore, the motor 110 for winding the seat belt is used. To the output interface 205 to stop the rotation drive of the
18). As a result, the current supply from the motor drive circuit 206 to the motor 110 stops, and the motor 110 stops operating. This routine ends and returns to the main program.

The seat belt is stored in the belt winding device 100 by the force of the winding spring 114 when the seat belt is not worn. When the seat belt is worn, minimal slack is removed.

Next, the operation control of the pretensioner as the second tension varying means will be described with reference to FIG.

The CPU 201 executes this routine periodically or by interrupt processing. The CPU 201
In the seat belt wearing state (S22; Yes), it is determined whether a collision is detected (S24). When a collision is detected by turning on the collision detection flag (S24; Yes), the explosive pretensioner 104 as the second tension variable means is operated. Thereby,
The seat belt retracts quickly to remove slack and restrain the occupant. Non-fastening of seat belt (S22; N
o), if no collision is detected (S24; No), the second
The present routine is terminated without operating the tension changing means.

When an impact is applied to the vehicle by the VSI sensor provided in the belt winding device 100, the drawer of the seat belt 302 is locked. Further, when the seat belt 302 is suddenly pulled out by the WSI sensor provided in the belt winding device 100, the pulling out of the seat belt 302 is locked.

FIG. 8 is a flowchart for explaining the operation control of the airbag device.

The CPU 201 executes this routine periodically or by interrupt processing. The CPU 201
When a collision is detected by turning on the collision detection flag (S32; Yes), an ignition signal is supplied to the airbag device, the explosive is ignited, and the bag is deployed by rapid expansion of the combustion gas (S34). This prevents a secondary collision of the occupant into the passenger compartment. If no collision is detected (S32; No), this routine ends.

FIG. 9 is a flowchart for explaining the forced operation of the seat belt lock mechanism.

When the first or second tension varying means is provided other than the belt winding device, for example, when it is provided on a buckle or a lap belt fixing portion, when the variable tension means operates, the belt is wound. Acts in the direction of withdrawal from the device. Therefore, the seat belt lock mechanism is forcibly activated in advance to prevent the seat belt from being pulled out and secure the belt tension.

The CPU 201 periodically monitors the seat belt wearing flag by executing the main program (S42). When the seatbelt wearing flag is on (S42; Yes), the CPU 201 determines whether or not there is a possibility of a collision based on the setting of the collision prediction flag (S44). If the flag is on (S44; Yes), a lock command signal is given to the output interface 205, and the lock mechanism 102 of the winding device 100 is turned on.
To work. When activated, the seat belt lock mechanism 102 prevents the pulled-out seat belt from being pulled out to prevent the belt from becoming loose, but allows the seat belt to be wound (S46). Note that when an impact is applied to the vehicle by the VSI sensor provided in the belt winding device 100, the pullout of the seat belt 302 is locked. Further, when the seat belt 302 is suddenly pulled out by the WSI sensor provided in the belt winding device 100, the pulling out of the seat belt 302 is locked.

The CPU 201 operates the motor drive circuit 206 to rotate the motor 110 in the belt winding direction to wind the webbing 302 (S48).
This removes some slack in the seat belt. For example, winding takes place until the belt exceeds a certain tension.
Alternatively, it may be performed for a predetermined time. Tension is RAM
The determination can be made by reading the sample value written in the current value area 203. This step removes slack in the seat belt before the collision.

If the seatbelt is not worn (S42; No) or the collision prediction flag is off (S44; No), the CPU 201 does not need to operate the seatbelt locking mechanism, and thus releases the lock. To the output interface 205. Thereby, the lock is released, and the belt can be pulled out (S50). A command is issued to the output interface 205 to stop the rotation of the motor 110 for winding the seat belt (S52). As a result, the current supply from the motor drive circuit 206 to the motor 110 stops, and the motor 110 stops operating. This routine ends and returns to the main program.

This routine can also be applied to the case where the first or second tension varying means is provided in the belt winding device. The seat belt is stored in the belt winding device 100 by the force of the winding spring 114 when the seat belt is not worn. The same is true in that a minimum slack is removed when the seat belt is worn.

FIG. 10 is a graph for explaining the change over time in the seat belt tension when the first and second tension varying devices and the airbag device are operated according to the control procedures of FIGS. .

In FIG. 10, at time t1, it is determined that there is a possibility of collision, the motor 110 starts operating, and the belt tension increases from the tension F0 by the winding spring. At time t2, a collision occurs. At time t3, the collision is detected and the pretensioner 104 and the airbag device 500 operate. Seat belt is motor 11
0 and the pre-tensioner 104
The tension suddenly increases from the tension F1 at time t1. The seat belt lock mechanism 102 locks the seat belt withdrawal by the VSI operation due to the impact of the collision. Time t
In 4, the tension reaches F2, but further a forward inertial force acting on the occupant (acting in a direction to pull out the belt from the winding unit 100) further increases the tension. When the tension becomes F3 at time t5, the energy absorbing mechanism by the torsion shaft 103a operates to pull out the seat belt, thereby suppressing an increase in belt tension.

FIGS. 11 to 22 show the winding section 100 of FIG.
An exploded perspective view and a main part longitudinal section mainly illustrating a seat belt lock mechanism (mechanical lock mechanism for reel, seat belt acceleration sensing means (WSI), vehicle deceleration sensing means (VSI)) 120 and an electromagnetic actuator 112. FIG. In FIG. 11, the pretensioner is not attached. If necessary for vehicle characteristics, as shown in FIG.
A pretensioner 104 is installed between the retractor base 1 and the power transmission unit 15 in FIG.

11 to 16, most of the retractor base 1 has a U-shaped cross section, and winding side shaft through holes are respectively formed in the facing side plates 1a and 1b so as to face each other. A reel 3, which is a winding shaft around which a seat belt 302 (not shown) is wound, is rotatably mounted in a state where the reel 3 is inserted through these winding shaft through holes.

An engaging inner tooth 2 is formed on an inner peripheral edge of the winding shaft through hole provided in the side plate 1a, and a ring member 4 is arranged in parallel outside the winding shaft through hole. Ring member 4
Is subjected to drawing along the inner peripheral edge, and when the ring member 4 is fixed to the outer side surface of the side plate 1 a by the rivet 40, a gap is formed between the engagement internal teeth 2 and the inner peripheral edge of the ring member 4. It is configured such that an axial gap is created.

An emergency lock mechanism for preventing the seat belt from being pulled out in an emergency is disposed on the side plate 1a side of the base 1. A shaft 15c (reel shaft 1) driven by an electric motor 110 via a timing belt 107 (not shown) is provided on the side plate 1b side of the base 1.
A power transmission unit 15 including a pulley 105, a take-up spring 114, a potentiometer 111, and the like connected to the power transmission unit 15 is disposed. The reel 3 is a substantially cylindrical winding shaft integrally formed of an aluminum alloy or the like.
The trunk portion 28 around which the seatbelt is wound is provided with a slit opening 28a that penetrates in a diametrical direction for inserting and holding the end portion of the seatbelt. Further, a flange member 13 formed separately is attached to the outer peripheral portion of the reel 3,
Prevents buckling of the seat belt. The seat belt wound around the reel 3 mounted on the retractor base 1 is passed through a seat belt guide 41 attached to the upper portion of the retractor base 1 on the back plate side, so that the entry / exit position is regulated. .

On both end surfaces of the reel 3, a rotation support shaft for rotatably supporting the reel 3 is provided. On the sensor-side end surface of the reel 3, a support shaft pin 6 formed separately is rotated. It is press-fitted as a spindle. On the sensor-side end face of the reel 3, a support shaft 7 that pivotally supports a pawl 16 which is a lock member engageable with the engagement internal teeth 2 formed on the side plate 1a so as to swing and rotate is provided. ing. Further, when the pole 16 swings and rotates in the direction of engagement with the engagement internal teeth 2, the pole rear end 16 e opposite to the swing side end of the pole 16 is positioned,
When a large load is applied to the pole 16 between the engagement inner teeth 2 and the pole 16, a pressure receiving surface 45 that receives the load is provided on the sensor-side end surface of the reel 3.

Further, on the sensor-side end surface of the reel 3, a swing lever member 20 pivotally supported by a ratchet wheel 18, which is a latch member of a lock operating means to be described later, is swingably supported.
Is provided with a locking projection 8 for restricting the counterclockwise rotation of. The recess 9 includes a tension coil spring 36 for urging the ratchet wheel 18 to rotate in the seat belt withdrawing direction (the direction of arrow X2 in FIG. 12) and an arm 26c of a lock arm 26 for pressing a sensor spring 25 described later. It is a runaway to prevent interference.

The swinging end of the pawl 16 has engaging teeth 16c which can be engaged with the engaging internal teeth 2 formed on the side plate 1a.
Are integrally formed. In the center of the pole 16,
A shaft hole 16a that fits loosely into the support shaft 7 is provided therethrough. On the sensor side surface of the pole 16, an engagement protrusion 16b located on the swinging end side and a pressing projection 16 located on the pole rear end 16e side are provided.
and d are projected.

That is, since the shaft hole 16a is loosely fitted to the support shaft 7, the pawl 16 is pivotally supported on the support shaft 7 so as to be swingably rotatable and relatively movable by a predetermined amount. Also, reel 3
The tip of the spindle 7 that has passed through the shaft hole 16a of the pawl 16 is crimped into the locking hole 17b of the holding plate 17 into which the through-hole 17a is fitted by the spindle pin 6 that has been press-fitted. The plate 17 is connected to the pole 16 from the end face of the reel 3.
Is prevented from rising.

The end of the engaging projection 16 b of the pawl 16 is disposed outside the holding plate 17 and
It is inserted into a cam hole 18a formed in a ratchet wheel 18 which is rotatably supported on the ratchet wheel 18. Then, when the ratchet wheel 18 rotates relative to the reel 3 in the seat belt winding direction (the direction of arrow X1 in FIG. 12),
Since the cam hole 18a acts to move the end of the engaging projection 16b radially outward from the rotation center axis of the reel 3, the pawl 16 engages with the engaging internal teeth 2 formed on the side plate 1a. It is pivotally rotated about the support shaft 7 in the direction (direction of arrow Y1 in FIG. 11).

That is, the pawl 16 is pivotally rotated in the direction in which the pawl 16 engages with the engaging internal teeth 2, and the engaging teeth 16 c
Constitutes a lock means for preventing the reel 3 from rotating in the seat belt withdrawing direction by engaging with the engagement internal teeth 2. The ratchet wheel 18 is a ratchet wheel whose center hole is rotatably supported by the support pin 6, and a ratchet tooth 18 b for engaging with the sensor arm 53 of the vehicle body acceleration sensing means 51 is provided on the outer peripheral portion. Is formed. Furthermore,
The flange portion 6a of the support pin 6 pivotally supports a center hole 30a of an inertia plate 30 which is a disk-shaped inertia member for constituting a seatbelt acceleration sensing means which is an inertia sensing means for sensing a seat belt withdrawal acceleration. are doing. A locking claw 23 protruding from the periphery of the center hole of the ratchet wheel 18 toward the outside of the winding device engages with the engaging hole 30b to position the inertia plate 30 in the thrust direction. The elongated protrusion 24 of the inertia plate 30 is engaged with the elongated hole 24 formed in the ratchet wheel 18, and one end edge 24a of the elongated hole 24 is positioned in the rotation direction of the inertia plate 30 when the emergency lock mechanism is not operated. Positioning is performed (see FIG. 14).

As shown in FIG. 14, a shaft portion 22 for rotatably supporting the lock arm 26 and a spring hook portion 55 project from the outer surface of the ratchet wheel 18. Then, as shown in FIG. 18, an opening 56 through which the spring hook 55 is inserted is formed in the inertia plate 30. The opening 56 is formed in a long hole shape in which the inertia plate 30 is rotatable relative to the ratchet wheel 18 in a state where the spring hook portion 55 is inserted, and one end thereof has a spring corresponding to the spring hook portion 55. A hook 57 is provided.

The pair of spring hooks 5
A compression coil spring 58 is inserted between the fifth and the fifth 57. As shown in FIG. 17, the compression coil spring 58 is in a state where the engagement protrusion 31 on the inertia plate 30 is in contact with the other end 24b of the elongated hole 24 formed in the ratchet wheel 18 (that is, in a non-contact state). (Locked state).

The inner surface of the ratchet wheel 18 is provided with a spring hook 21 for hooking the other end of the tension coil spring 36 having one end hooked to the hook 17c of the holding plate 17, and is provided with a tension coil spring. Reference numeral 36 rotationally urges the ratchet wheel 18 with respect to the reel 3 in the seat belt withdrawal direction (the direction of arrow X2). As shown in FIG. 15, the lock arm 26 includes an engagement claw 26 b capable of meshing with the internal gear 34 a of the gear case 34, and a pair of hooks 1 provided on the outer surface of the ratchet wheel 18.
Linear sensor spring 25 supported at both ends by 8d
And an arm 26c for pressing a central portion in the longitudinal direction of the arm.

Therefore, the lock arm 26 is
b constitutes a locking member that meshes with the internal gear 34a, which is the engaged portion, to prevent the ratchet wheel 18 from rotating in the seat belt withdrawing direction. Then, the engaging claw 26b
Is pressed against the contact portion 32 of the inertia plate 30 by the urging force of the sensor spring 25.
An opening is formed in the ratchet wheel 18 corresponding to the swing range of the arm 26c, and the arm 26c penetrates the opening. This is for ensuring the engagement state of the arm 26c with the sensor spring 25. Things.

The contact portion 32 has a first cam surface 32a on which the rotation of the inertia plate 30 does not affect the lock arm 26, and a cam surface on which the back 26d of the engaging claw 26b of the lock arm 26 slides. And a second cam surface 32b that swings the lock arm 26 so that the engagement claw 26b meshes with the internal gear 34a in accordance with the rotation delay of the inertia plate 30 with respect to the third gear 3.

In the unlocked state of the emergency lock mechanism, the first
Is in contact with the back 26d of the lock arm 26, and the back 26d does not contact the second cam surface 32b until the rotation delay of the inertia plate 30 with respect to the reel 3 exceeds a certain amount. ing. The length of the first cam surface 32a (that is,
The amount by which the inertia plate 30 rotates while the 6d is in sliding contact) is the inertial force acting on the inertia plate 30 when the entire amount of the seatbelt is retracted.
Causes a rotation delay with respect to the reel 3, the first cam surface 32a is so small that the back 26d of the lock arm 26 does not reach the second cam surface 32b with such a rotation delay.
Is set.

The lock arm 2 according to the present embodiment
6 is a contact claw 26e at the swinging end opposite to the engagement claw 26b.
Are formed. The inertia plate 30 has a contact claw 26e corresponding to the contact claw 26e.
Is provided with a stepped portion 33 which can be contacted. Step 33
When the inertia plate 30 is at the initial position in the unlocked state, the contact of the contact claw 26e restricts the rotation of the lock arm 26 in the locking direction. As shown in FIGS. 18 and 19, the inertia plate 30
When the back portion 26d of the lock arm 26 comes into contact with the second cam surface 32b due to a rotation delay of a predetermined amount or more, the pressing force of the second cam surface 32b
Can swing in the locking direction.

Further, on a support shaft 19 protruding from the inner surface of the ratchet wheel 18, a swing lever member 20 which is supported by a shaft hole 20a is swingably disposed. The swing lever member 20 is appropriately restricted from rotating in the counterclockwise direction by a locking protrusion 8 protruding from the sensor-side end surface of the reel 3, and has a pressing protrusion 16 d protruding from the sensor side surface of the pawl 16. It is assembled between the reel 3 and the ratchet wheel 18 so that the clockwise rotation is appropriately regulated by abutting between the support shaft 19 and the locking projection 8.

At the center of the gear case 34 provided outside the inertia plate 30, a shaft support 34b for rotatably supporting the reel 3 via the shaft pin 6 is provided. The flange portion 6a of the support pin 6 abuts on the bottom surface of 34b, and serves as a positioning surface of the reel 3 in the axial direction. Further, a box-shaped storage unit 50 for storing a vehicle body acceleration sensing unit 51 which is an inertial sensing unit for sensing the acceleration of the vehicle body is provided below the gear case 34.

A sensor cover 35 is disposed outside the side plate 1a that covers the gear case 34.

Next, the operation of the seat belt retractor will be described. First, in the normal use state, as shown in FIG. 17, the ratchet wheel 18 is applied to the reel 3 by the urging force of the tension coil spring 36 hooked on the spring hook 21 and the hook 17c of the plate 17. On the other hand, the pawl 1 is urged in the seat belt withdrawing direction (the direction of arrow X2 in the drawing), and the engaging projection 16b is engaged with the cam hole 18a.
6 is urged in a direction disengaged from the engagement internal teeth 2. Therefore, the reel 3 is rotatable, and the seat belt can be freely pulled out.

When the seat belt acceleration sensing means including the inertia plate 30 or the vehicle body acceleration sensing means 51 operates in an emergency such as a collision, the locking means prevents the lock operating means from rotating in the seat belt withdrawing direction. The lock arm 26 or the sensor arm 53 prevents the ratchet wheel 18 from rotating in the seat belt withdrawing direction, and activates the locking means of the winding device.

Then, after the vehicle body acceleration sensing means 51 or the seat belt acceleration sensing means is operated and the rotation of the ratchet wheel 18 in the seat belt withdrawing direction is stopped,
Further, when the seat belt is pulled out from the winding device, the ratchet wheel 18 causes a rotation delay with respect to the reel 3,
Since the rotation relative to the seat belt winding direction (the direction of the arrow X1), the cam hole 18a of the ratchet wheel 18 moves the engaging projection 16b of the pawl 16 radially outward from the rotation center axis of the reel 3. Therefore, the pole 16 is engaged with the engaging internal teeth 2 about the support shaft 7 (in FIG.
(1 direction).

Further, when the seat belt is pulled out from the winding device, the engaging teeth 16c of the pawl 16 mesh with the engaging internal teeth 2 to complete the operation. In this state, there is a gap between the pole rear end 16 e of the pawl 16 and the pressure receiving surface 45 of the reel 3, and the swing lever member 20 is connected to the locking projection 8 of the reel 3.
The rotation is regulated almost without play by the pressure projection 16 d of the pawl 16.

Here, the shaft hole 16a of the pole 16 is loosely fitted to the support shaft 7 of the reel 3, and is pivotally supported on the reel 3 so as to be swingable and rotatable by a predetermined amount. Further, when the seat belt is further pulled out of the winding device, the pole 16 is moved relative to the reel 3 around the rotation center axis of the reel 3 until the rear end 16e of the pole comes into contact with the pressure receiving surface 45. Relative rotation.

At this time, the pressing projection 16d of the pawl 16 is stationary relative to the side plate 1a, but the locking projection 8 of the reel 3 rotates in the seat belt withdrawing direction (the direction of arrow X2). By this movement, the swinging lever member 20 is pushed by the locking protrusion 8 with the contact point with the pressing protrusion 16d as a rotation fulcrum, and is rotated clockwise in FIG. When the swing lever member 20 swings clockwise in FIG. 12 around the contact point with the pressing projection 16 d as a rotation center, the shaft hole 20 a supported by the support shaft 19 of the ratchet wheel 18 rotates the reel 3. It rotates in the seat belt winding direction (the direction of arrow X1) with respect to the center axis. As a result, the ratchet wheel 18 is reversely rotated with respect to the reel 3 in the seat belt winding direction (the direction of the arrow X1).

Accordingly, even in the locked state where the vehicle body acceleration sensing means 51 or the seat belt acceleration sensing means is operated and the locking means of the winding device prevents the rotation of the reel 3 in the seat belt withdrawing direction, the rotation in the seat belt withdrawing direction is prevented. The blocked ratchet wheel 18 connects the sensor arm 53 in the vehicle body acceleration sensing means 51 or the lock arm 26 in the seat belt acceleration sensing means to the gear case 3.
4 can be set in a free state that can be released from engagement with the internal gear 34a.

In the locked state of the pawl 16, if a large tension acts on the seat belt, the gear case 3
4 and the shaft 15c of the power transmission unit 15
Is deformed, and the reel 3 tends to move upward. This movement is caused by the contact surface 3 formed on the reel.
a and the groove 3b are stopped by contacting the engaging internal teeth 2 and the engaging internal teeth 62 (see FIG. 11) on the side plate 1b, respectively, and the tension acting on the seat belt is received by these surfaces.

When the vehicle is stopped and the tension applied to the seat belt is released, the engagement between the ratchet wheel 18 and the internal gear 34a of the gear case 34 of the sensor arm 53 or the lock arm 26 has already been released. Therefore, the ratchet wheel 18 is connected to the tension coil spring 3
6, the cam hole 18a of the ratchet wheel 18 moves the engaging protrusion 16b of the pawl 16 toward the rotation axis of the reel 3. At this time, the tension in the pull-out direction acting on the seat belt is released as described above, and the reel 3
Can rotate in the seat belt winding direction (direction of arrow X1), so that the reel 3 moves in the direction of arrow X1 until the tip of the engaging tooth 16c of the pawl 16 does not interfere with the tip of the engaging internal tooth 2. When the pawl 16 rotates, the engaging internal teeth 2
Is pivoted about the support shaft 7 in the direction of releasing the engagement with the reel 3, the lock of the reel 3 is released, and the seat belt can be pulled out freely.

Next, winding by the electric motor 110 is performed from the seat belt pulled-out state, and the power transmission mechanism 15
When the entire amount of the seatbelt is suddenly wound up according to the rotational force of the above, the inertia plate 30, which is the inertia member of the seatbelt acceleration sensing means, rotates in the winding direction with respect to the reel 3 that has stopped suddenly. , Reel 3
The reel 3 advances in the winding direction, and a rotation delay occurs with respect to the reel 3 when viewed in the pull-out direction of the reel 3. However, the engagement claw 26b of the lock arm 26 is
After the rotation delay of the inertia plate 30 with respect to the reel 3 reaches a predetermined amount, the engagement claw 26b is connected to the internal gear 32 at the contact portion 32 of the inertia plate 30 that swings in the direction of engagement with the internal gear 34a. 34a, and is constituted by two cam surfaces 32a and 32b for swinging in the direction of 34a, and until the rotation delay of the inertia plate 30 with respect to the reel 3 reaches a predetermined amount, the engagement claw 26b is
It does not swing in the engagement direction of 4a.

In the embodiment of the present invention, an electromagnetic actuator 112 is further provided in the lock mechanism configured and operated as described above, as shown in the lower part of FIG. The electromagnetic actuator 112 is shown in FIGS.
As shown in (1), it is composed of a solenoid (excitation coil) 112a, a coil spring (elastic member) 112b, a plunger (magnetic core) 112c with a flange, and the like, and is arranged below the vehicle body acceleration sensing means 51.

In the normal state, the solenoid 112a is excited. In this state, as shown in the figure, the plunger 112c does not contact the ball weight 54 and does not affect the lock mechanism 51. When the control unit 200 releases the excitation of the solenoid 112a to lock the seat belt (S30 and the like), the plunger 112c is lifted by the urging force of the spring 112b. Plunger 11
The tip of 2c pushes up the ball weight 54 through the opening at the bottom of the sensor cover 52. When the ball weight 54 is pushed up, the sensor arm 53 is moved upward in the figure, and its locking projection 53a meshes with the ratchet teeth 18b of the ratchet wheel 18. Thus, the rotation of the ratchet wheel 18 in the seat belt withdrawing direction (the direction of the arrow X2 in FIG. 12) is prevented. When the seat belt is pulled out and the reel 3 is rotated in the pulling-out direction, the rotation of the latched ratchet wheel 18 and the reel 3 causes the pawl 16 to move radially outward of the reel 3 and the inner teeth 2 of the frame 1a. Mesh. This prevents the reel 3 from rotating in the pull-out direction.

In this example, when the exciting current is supplied to the solenoid 112a, the locking operation is not performed, and when the exciting current is cut off, the locking operation is performed. That is, the lock mechanism is operated by supplying a low-level operation signal. Therefore, when the power supply to the seat belt device is cut off, the seat belt can be locked.

FIG. 22 shows another configuration example of the electromagnetic actuator 112. In this example, the electromagnetic actuator is a solenoid 112 mounted on a frame.
a, plunger 112c, plunger 112c at one end
And a coil spring 112b that applies a biasing force to the lever 112d in the clockwise direction in FIG. When the claw portion of the lever 112d moves and comes into contact with the tooth surface 18b of the ratchet wheel 18, the ratchet wheel 1
Then, the rotation mechanism 8 is stopped, and the lock mechanism by the pawl 16 and the internal teeth 2 of the frame is operated.

In a normal state in which the exciting current is supplied from the control unit 200 to the solenoid 112a, the solenoid 11
2a is the plunger 1 against the coil spring 112b.
The claw at the other end of the lever 112d rotatably supported at one end with the plunger 112c is separated from the ratchet wheel 18. Therefore, the lock mechanism does not operate.

Next, the CPU cuts off the supply of the exciting current from the control unit 200 to lock the seat belt (S46 and the like). The plunger 112c is pulled downward in the drawing by the urging force of the coil spring 112b, and the lever 112d is rotated. As a result, the claw portion at the other end of the lever 112d engages (engages) with the teeth 18b of the ratchet wheel, and prevents the ratchet wheel 18 from rotating in the seat belt withdrawing direction. When the seat belt is pulled out and the reel 3 is rotated in the pulling-out direction, the rotation of the ratchet wheel 18 and the reel 3 locked causes the pole 1 to rotate.
6 moves radially outward of the reel 3 and meshes with the internal teeth 2 of the frame 1a. As a result, the rotation of the reel 3 in the pull-out direction is prevented, and the lock is completed.

FIGS. 23 to 27 show examples of the structure of another seat belt device to which the present invention is applied. In each drawing, the same reference numerals are given to portions corresponding to FIG.

FIG. 23 shows an example of another seat belt device to which the present invention is applied. In this example, buckle 3
The electric winch 3 having a motor 311 and a reel 312 for winding a wire 313 connected to a buckle 304 as a tension variable device for pulling or pulling a belt to the side 04.
10 is provided. By rotating the motor 311 in the forward and reverse directions, the wire can be pulled out and drawn in. The control unit 200 uses the winch 31 instead of driving the motor 110.
By driving the motor 311 of 0, the slack of the seat belt 302 is removed. Also in this case, the belt tension can be estimated by detecting the current value of the motor 311. In this configuration, the belt winding device 100 includes:
Although it is desirable to have a forced lock mechanism and a pretensioner, it is not necessary to use an electric winding device. An anchor 306 for fixing the end of the seat belt 302 is attached to the seat 30.
It may be fixed to 1. This makes it possible to remove the slack of the belt more quickly because the length of the portion where the seat belt 302 is pulled out is shorter than when the end portion of the seat belt is fixed to the vehicle body.

FIG. 24 shows an example of another seat belt device to which the present invention is applied. In this example, a tension changing device for removing slack of the belt is provided on the anchor 306 side (lap belt fixing portion) for fixing the end of the seat belt 302. Similarly, as the variable tension device, the motor 31
1. Reel 3 for winding wire 313 connected to buckle
12 can be used. As another example of the tension varying device, for example, a configuration in which a wire is pulled by a screw rod that is rotationally driven by a motor and a nut that reciprocates on the screw rod can be used.

In the example shown in FIG. 25, the belt winding device 10
0 is not the lower part of the center pillar of the body, but the seat 301
Mounted on The present invention can be applied to such a configuration.

In the example shown in FIG. 26, an electric belt winding device and a pretensioner 104a provided on the buckle side are used.
It consists of:

In the example shown in FIG. 27, an electric belt winding device and an anchor 3 for fixing the end of the seat belt 302 are provided.
The pre-tensioner 104b is provided on the 06 side.

A pretensioner can be incorporated in the electric winch 310 shown in FIGS. 23 and 24.

In the seat belt device of the embodiment, an electric motor is used as the first tension varying means, and an explosive pretensioner is used as the second tension varying means.
Both may be motors. Further, a spring may be used as a power source. Both the first and second tension varying means can be provided in the belt winding device, and one or both of the tension varying devices can be attached to other than the belt winding device. In this case, the attachment place can be, for example, the buckle side or the lap belt fixing portion.

[0102]

As described above, in the seat belt device of the present invention, the slack of the seat belt is removed by the first tension varying means before the collision, and the higher tension is achieved by the second tension varying means at the time of the collision. Since the occupant is restrained to the seat by the tension and the airbag is deployed at the same time, the occupant moves in the collision direction by the energy absorbing mechanism, and it is possible to avoid a state in which the occupant's head or the like hits the airbag during deployment.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a seat belt device in which a child seat is placed on a seat.

FIG. 2 is an explanatory diagram illustrating a configuration example of an electric belt winding device.

FIG. 3 is an explanatory diagram illustrating a potentiometer 111.

FIG. 4 is a functional block diagram illustrating a configuration of a control unit 200.

FIG. 5 is a circuit diagram illustrating a configuration example of a motor drive circuit.

FIG. 6 is a flowchart illustrating a control example of a first tension varying unit by a control unit;

FIG. 7 is a flowchart illustrating a control example of a second tension varying unit by a control unit;

FIG. 8 is a flowchart illustrating a control example of an airbag device by a control unit.

FIG. 9 is a flowchart illustrating a forcible locking operation of the seat belt lock mechanism by the control unit.

FIG. 10 is a graph illustrating a change in seat belt tension when the seat belt device operates.

FIG. 11 is a perspective view showing an example of a part of the seat belt retractor.

FIG. 12 is a perspective view showing another example of the seat belt retractor.

FIG. 13 is a cross-sectional view of the ratchet wheel 18 of the lock mechanism shown in FIG. 12 in a rotation axis direction.

FIG. 14 is an explanatory diagram illustrating the operation of the lock mechanism due to sudden withdrawal of the seat belt (seat belt acceleration).

FIG. 15 is an explanatory diagram for explaining a lock arm 26;

FIG. 16 is an explanatory diagram illustrating an inertia plate 30.

FIG. 17 is an explanatory diagram illustrating the operation of the lock mechanism due to seat belt acceleration.

FIG. 18 is an explanatory diagram illustrating an operation of a lock mechanism due to seat belt acceleration.

FIG. 19 is an explanatory diagram illustrating the operation of the lock mechanism due to seat belt acceleration.

FIG. 20 is an explanatory diagram for explaining the operation (unlocked state) of the electromagnetic actuator.

FIG. 21 is an explanatory diagram illustrating an operation (locked state) of the electromagnetic actuator.

FIG. 22 is an explanatory diagram illustrating an example of another electromagnetic actuator.

FIG. 23 is an explanatory view showing an example in which an electric winch as a belt tension varying means is attached to the buckle side and a belt end is fixed to a seat.

FIG. 24 is an explanatory view showing an example in which an electric winch as a belt tension varying means is attached to an end of the belt.

FIG. 25 is an explanatory diagram showing an example in which a belt winding device is provided on a seat.

FIG. 26 is an explanatory diagram showing an example in which a pretensioner is provided on the buckle side.

FIG. 27 is an explanatory diagram illustrating an example in which a pretensioner is provided at an end of a seat belt.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 seat belt winding device 104, 104a, 104b explosive pretensioner 200 control unit 302 seat belt 304 buckle 305 tongue plate 310 electric winch 500 airbag device

Claims (1)

[Claims] A seat belt for restraining an occupant in a seat; first and second tension varying means for varying a tension of the seat belt; a collision prediction for predicting a collision of a vehicle and responding to a possibility of the collision; A collision prediction unit that outputs a signal, a collision detection unit that detects a collision of a vehicle, and outputs a collision detection signal, and an airbag device that deploys an airbag by the collision detection signal to prevent a secondary collision of an occupant. Control means for controlling the first and second tension varying means based on the collision prediction signal and the collision detection signal; and tension limiting means for limiting the tension so that the tension of the seat belt does not exceed a predetermined value. A seat belt device comprising: