JP2001334913A - Seat belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat belt device capable of performing the winding of a webbing by a motor without giving an incompatibility to an occupant. SOLUTION: This seat belt device for constraining the occupant to a seat by the webbing comprises the motor 110 for rotating a reel for winding the webbing; a drawing quantity detecting means 11 for detecting the drawing quantity of the webbing from the reel; winding determining means S230, S232 for determining whether the webbing is windable or not; and a control means S234 for controlling the motor on determining the windability and controlling the driving force of the motor so as to be larger, the larger is drawing quantity of the webbing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt device, and more particularly to an improvement in a seat belt device that winds up webbing with a driving force of a motor.

[0002]

2. Description of the Related Art Conventionally, a seatbelt device has been used for restraining an occupant in a seat in the event of a vehicle emergency so as to secure the occupant. The seat belt device includes a winding device (retractor) that winds and stores a webbing that restrains an occupant on a seat on a reel. This winding device uses a spiral winding spring to apply a weak rotating force to the reel in the winding direction, thereby removing excess slack of the webbing. Some winding devices have a built-in motor for rotating and driving the reel, and the webbing is wound by the motor. For example, in a seat belt device disclosed in Japanese Patent Application Laid-Open No. 2000-52926, a motor is used for a winding device, and the winding speed of the motor is set to “high” in response to “open” and “close” of a door. When the door is opened, the webbing is quickly wound up to prevent the webbing from being caught in the door.

[0003]

However, the tightening of the seat belt is different between the case where the excess slack of the webbing is gradually removed with a weak tension using a spiral winding spring and the case where the webbing is wound at a constant speed by a motor. Since the degree of adjustment is different, a wearer who is accustomed to the former may feel uncomfortable when using the latter.

[0004] In addition, Japanese Patent Laid-Open No. 2000-52926 described above
As shown in the figure, when the webbing is wound up at a high speed and the winding is suddenly stopped, the tongue plate into which the webbing is inserted may jump and hit the inner wall of the vehicle.

Accordingly, it is an object of the present invention to provide a seat belt device capable of winding a webbing without giving a wearer an uncomfortable feeling.

Another object of the present invention is to provide a seat belt device in which the tongue plate is prevented from jumping during webbing winding.

[0007]

According to the present invention, there is provided a seat belt apparatus for restraining an occupant to a seat by webbing, comprising: a motor for rotating a reel for winding the webbing; Withdrawal amount detecting means for detecting the amount of webbing withdrawn from the reel, winding determination means for determining whether or not the webbing can be wound, and controlling the motor when it is determined that the winding is possible, Control means for controlling the motor so that the rotational driving force of the motor increases as the amount of pulling out the webbing increases (or decreases the rotational driving force of the motor in accordance with the remaining amount of winding of the webbing). Prepare.

With this configuration, it is possible to take up the webbing as quickly as possible in the state where the webbing is mounted and to reduce the uncomfortable feeling of mounting the webbing by preventing the webbing from strongly restraining the occupant. . In addition, in the state where the webbing is not mounted, it is possible to prevent the tongue plate from jumping when the webbing is wound.

Preferably, in the state where the webbing is not mounted, when the webbing winding position is not at the storage origin, the winding determination means drives and winds the webbing with a predetermined winding force, and When it is wound up, it is determined that it can be wound up, and in the state of mounting the webbing,
When the winding position of the webbing is not at the mounting origin, the webbing is driven to be wound with a predetermined winding force. When the webbing is wound by a predetermined amount or more, it is determined that the webbing can be wound.

[0010] Preferably, the driving force of the motor set in accordance with the amount of pull-out is a first driving force necessary for winding the webbing.
And the second driving force which is the maximum driving force of the motor.

[0011]

FIG. 1 shows an example of a seat belt device for a vehicle. The seat belt device is used to move the occupant to the seat 3
01, an electric winding device 100 that winds one end of the webbing 302 with an electric motor, a through anchor 303 that turns the webbing 302 near the shoulder of the occupant, and the webbing 30.
2, a tongue plate 305 that engages with a buckle 304 disposed on the waist, an anchor plate 306 that fixes the other end of the webbing 302 to the vehicle body, and the buckle 30.
4, a buckle switch 307 for detecting the installation of the webbing, and a door switch 401 for detecting the opening and closing of the door.
(Not shown), and includes a control unit 200 (not shown) for controlling the motor 110 of the winding device 100.

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 the webbing 302 is wound, and a reel shaft 103a which is connected to the left end side of the reel 103 and serves as a center axis of rotation of the reel. The reel shaft 103a absorbs energy (E
A twist shaft for the purpose of A) may be used. At the right end of the reel shaft 103a, a seat belt lock mechanism 102 for locking the webbing 302 from being pulled out is provided. The seat belt lock mechanism 102 includes an operation of locking the pullout of the belt when a predetermined deceleration acts on the vehicle, and an operation of locking the pullout of the webbing 302 when the webbing 302 is pulled out at a predetermined acceleration. I have. Further, the lock mechanism 102 is further provided with an electromagnetic actuator 112 described later for forcibly operating the lock mechanism 102 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. The seat belt lock mechanism 102 is configured so that the webbing 302 can be wound by the electric motor 110 even when the webbing 302 is pulled out.

The pretensioner 104 is operated by the output of a collision detector (not shown), and
Is rotated in the seat belt winding direction to forcibly wind the seat belt and restrain the occupant to the seat. The pretensioner 104 is, for example, an explosive pretensioner, and includes a gas generator, a cylinder that seals gas generated from the gas generator, a piston that moves in the cylinder by gas pressure,
The movement of the piston is controlled by the reel shaft 10 via the clutch mechanism.
It is constituted by a transmission mechanism or the like for converting the rotation into the rotation of 3a.

The reel 103 is driven to rotate by a motor 110 via power transmission means. This power transmission means is, for example, a pulley 10 fixed to the reel shaft 103a.
5. Pulley 10 fixed to shaft of DC electric motor 110
6. It is composed of a power transmission belt 107 and the like disposed between the pulleys. A predetermined number of external teeth are formed on the outer circumference of the pulleys 105 and 106, respectively.
A predetermined number of internal teeth are also formed on the inner circumference of the. 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 or shortage.
The rotation of 10 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. The motor 110 is provided with an encoder 111, which detects the rotation of the rotation shaft of the motor and transmits a signal indicating the rotation direction and the number of rotations to the control unit 200.

FIG. 3 is a block diagram showing a portion related to the present invention in the control system of the seat belt device. As described above, the buckle switch 307 is built in the buckle, detects whether or not the webbing is attached, generates a signal according to whether or not the webbing is attached, and supplies the signal to the control unit 200. The door switch 401 detects opening / closing of a vehicle door and outputs a signal corresponding to the opening / closing. Further, speed information of the own vehicle is provided from an in-vehicle computer (not shown). Drive circuit 210
Is a motor 1 according to a signal supplied from the control unit 200.
10 is driven. The encoder 111 includes, for example, a magnetized disk in which N and S poles are alternately formed on the outer circumference provided on the rotating shaft of the motor 110, and two holes arranged so as to generate outputs that are shifted from each other by ４ period. A two-phase pulse train φ1 is detected by detecting the rotation of the rotating shaft of the motor with a sensor
And φ2 are generated, and the rotation direction and the rotation amount (rotation angle) are transmitted to the control unit 200. The pulse trains φ1 and φ2 are controlled by the control unit 2.
The data is digitized by an up / down counter in the input / output interface 00 and becomes an encoder output corresponding to the amount of webbing withdrawn. The control unit 200 includes, for example, a CPU that executes a control program, a RAM that stores processing data, a ROM that stores a program and the like, a built-in timer, and a microcontroller that includes an input / output interface that performs signal conversion and the like. The input / output interface sets a “belt wearing flag” and a “door opening / closing flag” in a flag register (or RAM) in accordance with opening / closing of the buckle switch 307 and the door switch 401, respectively. The CPU of the input / output interface monitors the encoder output and sets various flags in the flag register. For example, based on the difference between the previous value and the current value, a “movement flag” indicating whether the webbing 302 has moved, a “direction flag” indicating the winding direction of the webbing 302 (rotation direction of the motor), a reference value (storage origin, A “shift flag 1, 2” or the like indicating whether the webbing 302 has shifted from the storage origin based on the difference between the mounting origin) and the current value is set in the flag register. By referring to the various flags, the control unit 200 can determine the stop of the webbing winding, the deviation of the webbing 302 from the reference position, the presence or absence of the webbing, the opening and closing of the door, and the like. The motor 110 is controlled based on each input signal.

FIG. 4 is a flowchart for explaining the operation of the control unit 200. First, register values, flag values, and the like are set to respective predetermined values (initial values) by initialization (S10).
2). Subsequently, an operation of setting a storage origin is performed in order to memorize a rotation amount (encoder output) corresponding to a state in which the webbing 302 is stored (stored). For example, the motor 110
Is driven to drive the webbing 302 with a predetermined winding force (S104), and it is determined whether or not the winding operation of the webbing 302 is stopped (S106). This can be performed by the value of the movement flag described above. If not stopped, the winding operation is continued (S106; No,
S104). If it has stopped (S106; Yes),
It is determined that the winding limit of the webbing 302 is reached, and the output of the encoder is stored in the RAM as the storage origin (S10).
8). After storing the storage origin, the winding drive of the motor is stopped (S110). In this state, the motor can idle and the occupant can freely pull out the webbing 302.

Next, the control unit 200 controls the webbing 302
It is determined whether or not the extraction amount has shifted (changed) from the storage origin (S112). This can be done by reading the value of the deviation flag. If there is no deviation (S112; N
o), it is determined whether the door beside the seat to which the webbing to be monitored is attached has changed from a closed state to an open state based on a change in the door open / close flag (S114). If the door opens, the webbing 30
The second winding drive is performed (S104). Thus, when the door is opened, the storage origin of the webbing 302 is reset. For example, when the occupant does not wear the belt even when the door is closed, the storage of the webbing 302 is hindered, and the control unit stops winding the webbing 302 on the way, the storage origin in the state of the webbing 302 is determined. Is set,
When the occupant opens the door in order to get off, the winding drive is performed, the storage origin of the webbing 302 is set again, and the webbing 302 is returned to the original storage origin.

When the webbing 302 is displaced (S11)
2; Yes), it is determined that the webbing 302 has been pulled out by the occupant. Next, it is determined whether or not the webbing is attached based on the value of the buckle flag (S116). If the webbing 302 is not mounted (S116; N
o), it is determined whether or not the webbing 302 has been pulled out based on the value of the movement flag (S118). If the drawer does not stop (S118; No), the webbing 3 during this time
02 is monitored (S116, S116).
118).

When the withdrawal of the webbing 302 is stopped (S118; Yes), the control unit 200 supplies a low-level signal to the drive circuit 210 to cause the motor 110 to wind the webbing 302 with a weak driving force (S120). It is determined whether or not the webbing 302 has been wound based on the value of the movement flag (S122). If it is wound up,
It is determined that the webbing 302 can be wound (S1
22; Yes), the webbing withdrawal amount D from the storage origin
The winding drive is performed with the winding force F according to 1. Winding force F
Is set by, for example, F = K1 × D1. The control unit 200 supplies a signal of a level corresponding to the winding force F to the drive circuit 210 to cause the motor 110 to generate the winding force F. Here, K1 is a constant. The winding force F is set between a lower limit F1 and an upper limit F2 of the winding force. For example, considering the weight of the tongue plate and the sliding resistance between the webbing 302 and the through anchor, the interior parts of the vehicle, and the like, and the webbing 302, the lower limit value F1 is set to be equal to or greater than the winding force that can be stored without slack. The upper limit F2 is set to be equal to or less than the maximum force of the motor (S124). The control unit 200 reads the deviation flag,
It is determined whether the webbing 302 has been wound up to the storage origin (S126). If it has not been wound up to the storage origin (S126; No), steps S122 to S126 are repeated, and the winding force F according to the current webbing withdrawal amount.
To perform winding drive. Since the webbing withdrawal amount gradually decreases, the winding force F also decreases. Thereby, the webbing 302 is quickly wound by the large force of the motor, and at the end of the storage of the webbing 302, the webbing is wound with the webbing winding force suppressed. It is possible to reduce the possibility that the tongue plate collides with the inner wall of the vehicle and the like, and that the colliding sound and the inner wall are damaged. When the webbing 302 is wound up to the storage origin (S126; Ye)
s), the process returns to the winding stop state (S110), and the webbing is pulled out.

When the webbing is not wound up even if a weak force for winding up the webbing 302 is applied (S120) (S1).
22; No), for example, when the vehicle is stopped by an occupant or is caught by an in-vehicle accessory, this continues for a predetermined time (or a predetermined number of times of determination) (S1).
28; Yes), if the door is closed (S130;
Yes), reset the storage origin (S104 to S11)
0). Thereby, when the webbing is caught in the middle and the occupant gets in and the webbing 302 is not used,
Unnecessary driving of the motor can be stopped. If the predetermined time has not elapsed (S128; No) or the door is open (S130; No), it is determined that there is a high possibility that the occupant will use the motor, and the motor winding drive is temporarily stopped. After that (S132), steps S116 to S122 are repeated to take up the webbing 302.

As shown in FIG. 5, when the webbing is mounted (S116; Yes), the control unit 200 drives the motor to operate with a weak winding force in order to wind the webbing 302. (S202). It is determined whether the winding operation has stopped based on the output of the encoder (S204). If not stopped (S204; N
o), it is confirmed that the webbing 302 is mounted (S206; Yes), and the winding drive is continued (S2).
02 to S206). When the winding operation is stopped (S20)
4; Yes), and gradually increase the winding force (S20).
8) It is determined whether a predetermined winding force has been achieved (S).
210). If the winding force does not reach the predetermined value (S2
10; No), it is confirmed that the webbing 302 is attached (S212; Yes), and the winding force is continuously increased (S208 to S212). The predetermined winding force is
The force is such that excess slack of the mounted webbing 302 can be removed, and is, for example, about 40N. The reason why the winding force is gradually increased is to reduce the discomfort to the occupant as much as possible.

When a predetermined winding force is reached (S210; Y
es), the position (encoder output) of the webbing 302 is stored as the mounting origin (S212).

Thereafter, the winding force is gradually reduced (S2
14) It is determined whether the winding force has reached a predetermined value (S216). The predetermined value is, for example, a relatively low value of 0N or more. If the predetermined value has not been reached (S2
16; No), it is confirmed that the webbing 302 is mounted (S218), and the winding force is further reduced (S214). By gradually lowering the winding force, discomfort to the occupant is reduced. When the predetermined value is reached (S21
6; Yes), the winding drive of the webbing 302 is stopped (S220). After the drive is stopped, the control unit 200 drives the motor to the drawer side by a predetermined amount determined from the output of the encoder to give the webbing 302 a predetermined slack. Thereby, the feeling of oppression caused by the webbing is reduced (S222). If the webbing is released (S206; Yes, S212; Yes and S
218; Yes), the process proceeds to step S124 to wind the webbing 302.

Next, it is determined whether or not the withdrawal amount (webbing position) of the mounted webbing 302 has deviated from the mounting origin (S224). If it is shifted (S224;
Yes), it is determined whether the movement of the webbing 302 has stopped (S226). When the amount of withdrawal of the webbing 302 has not changed from the drawing origin (S224; N)
o), and when the movement of the webbing 302 is not stopped (S226; No), it is confirmed that the webbing 302 is mounted (S228), and the monitoring is continued (S224 to S228). If the mounting of the webbing 302 is released, the process proceeds to step S124 described above in order to wind the webbing 302.

When the movement of the shifted webbing 302 is stopped (S226; Yes), the control unit 200 transmits the webbing 3
02 is performed with a weak winding force (S230).
It is determined whether the webbing 302 can be wound up (S232). This corresponds to a determination as to whether or not the occupant has moved his body and returned to the original position, or whether or not the webbing 302 has been pulled out to stop pulling out and the webbing 302 has been set free. When it is determined from the output of the encoder that the webbing 302 has been wound (S232; Y
es) The winding drive is performed with the winding force F. Winding force F
Is represented by F = K2 × D2. D2 is the current withdrawal amount of the webbing 302 from the mounting origin, and K2 is a constant indicating the relationship between the winding force and the webbing withdrawal amount from the mounting origin. However, the winding force F is set so as not to exceed the range between the lower limit F3 and the upper limit F4. For example, the lower limit value F3 is equivalent to a winding force capable of winding the webbing 302 to the mounting origin in consideration of the weight of the webbing 302, the sliding resistance between the webbing and the through anchor, the interior parts of the vehicle, and the occupant's clothes. Power to do. Upper limit F
4 is the maximum value of the winding force that can be generated by the motor. In this way, a winding force corresponding to the webbing withdrawal amount is given to the motor (S234). It is determined whether the webbing 302 has been wound up to the mounting origin (S23).
6). If it has not reached the mounting origin (S236;
No), the winding force F according to the current amount of withdrawal (remaining amount of withdrawal) of the webbing 302 is reset, and the webbing 30 is removed.
2 is repeated (S232 to S236). Thus, the webbing is wound with a winding force corresponding to the remaining amount of the webbing 302 pulled out, so that the slack is removed in the same manner as the winding of the webbing 302 by the spiral spring, and the occupant's uncomfortable feeling is reduced. When the webbing 302 is wound up to the mounting origin (S236; Yes), the webbing 30
2 returns to the monitoring state as to whether or not it deviates from the mounting origin (S
224).

On the other hand, if the webbing 302 is not wound up even if the webbing 302 is driven to wind up (S23).
2; No), it is determined whether or not the unwound state continues for a predetermined time (or whether or not the unwound state has been repeated a predetermined number of times) (S238). This means that if the occupant moves and stops in that state, the webbing 30
This corresponds to the case where 2 has been pulled out and stopped. When the predetermined time has elapsed (S238; Yes), it is determined whether the speed of the host vehicle is equal to or higher than a predetermined value (S240). If the speed of the own vehicle exceeds the predetermined speed (S240; Yes), the process proceeds to step 202 to reset the mounting origin. If the predetermined time has not elapsed (S238; No), and if the speed of the host vehicle is equal to or lower than the predetermined speed (S240; No), the winding drive of the motor is temporarily stopped (S242), and the release of the webbing is monitored. While (S228), step S2
24 to S232 are repeated to check whether the webbing 302 has been wound up. If the webbing has been released (S228; No), the process proceeds to step S124 to wind up the webbing 302.

As described above, after the occupant wears the webbing and once sits down (S202 to S222), the changed seating position is changed to a new driving position (seating position) by changing the position or posture of the occupant. (S224)
To S230), the webbing is wound by the winding force that decreases according to the remaining amount of the withdrawal amount (S232 to S232).
S236), it is possible to reduce the sense of incongruity caused by performing the winding drive many times. In addition, since the predetermined speed is added to the judgment factor (S240), the occupant moves the body to pull out the webbing to check left and right safety in an extremely low speed state such as a temporary stop or a stop state, and continues the state for a while. In such a case, it is possible to avoid setting the mounting origin of the webbing in that state.

[0028]

As described above, in the seat belt device of the present invention, when the webbing is wound by the motor, the winding force is gradually reduced as the drawn webbing is wound. Less discomfort to the occupants. In addition, when the webbing is released, the tongue plate jumps due to the winding of the webbing is reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an outline of a seat belt device.

FIG. 2 is an explanatory diagram illustrating an electric winding device (retractor).

FIG. 3 is a block diagram illustrating a control system of the seat belt device.

FIG. 4 is a flowchart illustrating an operation of a control unit 200.

FIG. 5 is a flowchart illustrating an operation of a control unit 200.

[Explanation of symbols]

 110 Motor 111 Encoder 200 Control unit 307 Buckle switch 401 Door switch

Claims (1)

[Claims] 1. A seat belt device for restraining an occupant to a seat by webbing, a motor for rotating a reel for winding the webbing, a drawer amount detector for detecting a drawer amount of the webbing from the reel, Winding determination means for determining whether or not the webbing can be wound; and controlling the motor when determining that the webbing can be wound, and increasing the rotational driving force of the motor as the webbing withdrawal amount increases. And a control unit for controlling the seat belt device so that