JP2012011955A - Seat belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat belt device capable of reliably releasing an emergency lock mechanism, without imparting a sense of incongruity to an occupant.SOLUTION: The emergency lock mechanism 22 is released from a lock by a predetermined quantity or more of rotation in the webbing winding direction of a belt reel 12. A controller 21 includes: a low speed winding unit 50 for driving a motor 10 at a first speed of a low speed in the webbing winding direction; a high speed winding unit 51 for rotating the motor 10 at a second speed of a high speed in the webbing winding direction; and an electric current-detecting unit 52 for detecting a carrying electric current of the motor 10. The controller 21 performs driving of the motor 10 by the low speed winding unit 50 when releasing the lock, and switches to the driving of the motor 10 by the high seed winding unit 51 when the electric current-detecting unit 52 detects an electric current value of a predetermined value or more.

Description

  The present invention relates to a seat belt device for restraining an occupant seated on a seat by webbing.

  2. Description of the Related Art As a vehicle seat belt device, there is known a vehicle equipped with an emergency lock mechanism that mechanically locks a webbing drawer when vehicle behavior becomes unstable in an emergency.

This emergency lock mechanism has a lock actuating drum that rotates relative to the side of the belt reel around which the webbing is wound when a predetermined torque or more acts between the belt reel and the belt reel and the lock actuating drum in one direction. And a locking claw that meshes with the locking groove of the casing when rotated relative to the casing. Furthermore, it operates when the vehicle is in an unstable state at a position close to the lock operation drum (for example, when an acceleration (deceleration) of a predetermined amount or more is applied to the vehicle or the vehicle is tilted by a predetermined amount or more). A vehicle sensor is provided, and a braking force is applied to the lock operation drum by the operation of the vehicle sensor.
Therefore, when the vehicle behavior becomes unstable and the vehicle sensor is activated, the lock operation drum is braked, and when the webbing is about to be pulled out, the belt reel and the lock operation drum rotate relative to each other in one direction. Thereby, the lock claw meshes with the lock groove of the casing, and as a result, the rotation of the belt reel in the webbing pull-out direction is locked.
Also, after the emergency locking mechanism is locked, if the webbing pull-out force is lost and the belt reel rotates in the winding direction by the force of the return spring, the belt reel and the locking drum are rotated relative to each other by a predetermined amount. The engagement between the lock claw and the lock groove is automatically released.

By the way, in recent years, as a seat belt device for a vehicle, a device in which a motor is connected to a belt reel is known for assisting in winding a return spring and restraining an occupant according to a vehicle state.
In a seat belt device provided with such a motor, it has been studied that the emergency lock mechanism is unlocked by a motor. In this case, when the emergency lock mechanism is activated and the rotation of the belt reel in the webbing pull-out direction is locked, the emergency lock mechanism is forced to lock by rotating the belt reel by a predetermined amount or more in the winding direction with a motor. (For example, refer to Patent Document 1).

Japanese Patent No. 36552683

  However, in the case of the conventional seat belt device, when the emergency lock mechanism is unlocked, the motor suddenly rotates the webbing reel in the winding direction, giving the passenger a sudden tightening feeling, and the passenger mistaken for malfunction. Is concerned.

  Accordingly, the present invention is intended to provide a seat belt device that can reliably release the emergency lock mechanism without causing the passenger to feel uncomfortable.

The seat belt device according to the present invention employs the following means in order to solve the above problems.
The invention according to claim 1 includes a belt reel (for example, belt reel 12 of the embodiment) wound with webbing (for example, the webbing 5 of the embodiment), and the belt reel when the vehicle behavior becomes unstable. Emergency lock mechanism (for example, emergency lock mechanism 22 of the embodiment) that mechanically locks the rotation of the belt reel in the webbing pull-out direction and is automatically unlocked by the rotation of the belt reel more than a predetermined amount in the webbing take-up direction. A seat belt device comprising: a motor (for example, the motor 10 of the embodiment) that applies a rotational driving force to the belt reel; and a control device (for example, the controller 21 of the embodiment) that controls the motor. The controller drives the motor at a low speed in the webbing take-up direction when the emergency lock mechanism is unlocked, When the tension in the ring exceeds a predetermined value, characterized in that for switching the driving speed of the motor at high speed.
In this case, when the vehicle behavior becomes unstable and the emergency lock mechanism is locked and then the vehicle state is stabilized, the control device first drives the motor at a low speed in the webbing take-up direction. When the webbing tension becomes equal to or higher than the predetermined value while the webbing is being wound at a low speed, the control device switches the motor driving speed at that time.

  The invention according to claim 2 is the seat belt apparatus according to claim 1, wherein the control means drives the motor at a first low speed in the webbing take-up direction (for example, according to the embodiment). A low-speed winding means 50), a high-speed winding means for rotating the motor in the webbing winding direction at a high-speed second speed (for example, the high-speed winding means 51 of the embodiment), and an energization current of the motor is detected. Current detection means (for example, the current detection means 52 of the embodiment), and when the emergency lock mechanism is unlocked, the motor is driven by the low-speed winding means, and the current detection means is a predetermined value. When the above current value is detected, the motor is switched to driving of the motor by the high-speed winding means.

  According to a third aspect of the present invention, in the seat belt device according to the second aspect, the control means may cause the emergency lock mechanism to lock again during a total webbing winding time when the emergency lock mechanism is unlocked. When the predetermined time is reached, the winding drive of the motor is stopped.

  According to the first aspect of the invention, when the emergency lock mechanism is unlocked, the motor is first driven at a low speed in the webbing take-up direction, and the motor driving speed is increased when the webbing tension exceeds a predetermined value. Therefore, at the initial stage of unlocking, the webbing winding is started without causing a sudden pull-in feeling to the occupant, and the webbing is quickly performed from the time when the occupant starts to grasp that the unlocking is started to the unlocking position. Can be pulled in. Therefore, according to the present invention, the emergency lock mechanism can be reliably released without causing the passenger to feel uncomfortable.

  According to the second aspect of the invention, when the emergency lock mechanism is unlocked, the motor is first driven by the low-speed take-up means, the webbing tension increases, and the current detection value by the current detection means becomes a predetermined value. Since switching to motor driving by the high-speed take-up means is performed at the time described above, the emergency lock mechanism can be reliably released without giving a sense of incongruity to the occupant with a simple configuration.

  According to the third aspect of the invention, since the total winding time of the webbing at the time of unlocking is managed and the driving of the motor is stopped when the possibility that the emergency locking mechanism locks again becomes small, the emergency locking mechanism It is possible to eliminate the problem of frequent locking and unlocking.

1 is a schematic configuration diagram of a seat belt device according to an embodiment of the present invention. It is a schematic block diagram centering on the belt reel and controller of the seatbelt apparatus of one Embodiment of this invention. It is a disassembled perspective view of the emergency lock mechanism of the seatbelt apparatus of one Embodiment of this invention. It is a flowchart which shows the flow of control of the seatbelt apparatus of one Embodiment of this invention. It is a flowchart which shows the flow of control of the seatbelt apparatus of one Embodiment of this invention. It is a flowchart which shows the flow of control of the seatbelt apparatus of one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall schematic configuration of a seat belt device 1, and reference numeral 2 in the figure denotes a driver side seat on which a passenger 3 is seated.
The seat belt device 1 is a so-called three-point seat belt, and a webbing 5 is drawn upward from a retractor 4 attached to a center pillar (not shown), and the webbing 5 is supported on the upper side of the center pillar 6. And the tip of the webbing 5 is fixed to the vehicle body floor via an outer anchor 7 on the outer side of the passenger compartment of the seat 2. A tongue plate 8 is inserted between the through anchor 6 and the outer anchor 7 of the webbing 5, and the tongue plate 8 can be attached to and detached from the buckle 9 fixed to the vehicle body floor of the seat 2 on the inner side of the vehicle body. It has become.

  The webbing 5 is wound around the retractor 4 in the initial state, and the occupant 3 pulls it out by hand to fix the tongue plate 8 to the buckle 9, thereby restraining the chest and abdomen mainly of the occupant 3 with respect to the seat 2. To do. In addition, the seat belt device 1 automatically performs the winding and pulling-out operation of the webbing 5 by the electric motor 10 when the behavior of the vehicle becomes unstable or when the webbing 5 is slack during normal driving. To do. The motor 10 is controlled by a controller 21 (control device).

FIG. 2 is a schematic configuration diagram of the seat belt device 1 for explaining the functions of the retractor 4 and the controller 21.
As shown in FIG. 2, the retractor 4 has a webbing 5 wound around a belt reel 12 rotatably supported by a casing 14 (see FIG. 3, omitted in FIG. 2). The belt reel 12 is connected to a rotating shaft 10 a of the motor 10 via a power transmission mechanism 13 including a clutch 20 so as to be interlocked. The power transmission mechanism 13 decelerates the rotation of the motor 10 and transmits it to the belt reel 12. The retractor 4 is provided with a winding spring (not shown) that urges the belt reel 12 in the webbing winding direction. When the belt reel 12 and the motor 10 are separated by the clutch 20, the tension by the winding spring is increased. It acts on the webbing 5. The clutch 20 is turned on when the motor 10 is rotating forward, and is turned off when the motor 10 is rotated backward.

Further, the retractor 4 is provided with a rotation sensor 11 (position detection means) for detecting the rotation position of the belt reel 12. The rotation sensor 11 includes, for example, a magnetic disk in which different magnetic poles are alternately magnetized along the circumferential direction and rotates integrally with the belt reel 12, and a pair disposed in the vicinity of the outer peripheral edge of the magnetic disk. And a sensor circuit for processing a detection signal of the Hall element, and a pulse signal processed by the sensor circuit is output to the controller 21.
In this case, the pulse signal input from the sensor circuit to the controller 21 according to the rotation of the belt reel 12 is used to detect the rotation amount, rotation speed, rotation direction, and the like of the belt reel 12. That is, the controller 21 detects the amount of rotation of the belt reel 12 (the amount of winding / drawing of the webbing 5) by counting the pulse signal, and calculates the change rate (frequency) of the pulse signal to calculate the belt reel. 12 is obtained, and the rotation direction of the belt reel 12 is detected by comparing the rising edges of the waveforms of both pulse signals.

Further, on the input side of the controller 21, in addition to the rotation sensor 11, a longitudinal acceleration sensor 40 that detects acceleration in the longitudinal direction of the vehicle, a lateral acceleration sensor 41 that detects acceleration in the lateral direction of the vehicle, and the yaw direction of the vehicle Vehicle state detection means such as a yaw rate sensor 42 for detecting the angular acceleration is connected. Furthermore, although not shown in FIG. 2, the controller 21 is connected to other controllers such as a vehicle behavior stabilization system and a rear-end collision reduction brake system through an in-vehicle network, and information on when the vehicle is in an unstable state is It receives from these controllers through the network.
The controller 21 determines an emergency state (an unstable state of vehicle behavior) based on input signals from the longitudinal acceleration sensor 40, the lateral acceleration sensor 41, the yaw rate sensor 42, other controllers, and the like, and determines that the state is an emergency state. The energization of the motor 10 is controlled so that the webbing 5 is pulled in greatly or intermittently.

  The retractor 4 has a belt when a deceleration (acceleration) of a predetermined value or more acts on the vehicle (when the vehicle behavior becomes unstable) or when the webbing 5 is about to be pulled out suddenly. An emergency lock mechanism 22 that mechanically locks the rotation of the reel 12 in the webbing pull-out direction is provided.

FIG. 3 shows details of the emergency lock mechanism 22 provided in the retractor 4.
The casing 14 is provided with a pair of side walls 14A and 14B. The power transmission mechanism 13 (see FIG. 2) and a spring case (not shown) that house the return spring are attached to one side wall 14A. A retainer 24 that supports a lock operation drum 23 described later is attached to the side wall 14B. Further, a substantially circular hole 25 is provided in the side walls 14A and 14B on both sides, and a lock groove 26 inclined in the webbing take-up direction is formed on the inner periphery of the hole 25 in the other side wall 14B.

A locking base 27 is integrally fixed to one end side of the reel shaft 12 a of the belt reel 12, and a lock operation drum 23 is fitted to the tip of the reel shaft 12 a that passes through the locking base 27. The lock actuating drum 23 is fitted to the reel shaft 12a with a small frictional resistance. When the belt reel 12 is rotated normally, the lock actuating drum 23 rotates integrally with the belt reel 12, and a rotational force in the opposite direction is applied to the locking base 27. Sometimes, it rotates relative to the locking base 27 within a set angle range. A swing arm 28 having a lock claw 28a is swingably attached to a position separated from the rotation center of the locking base 27.
When the tip end side lock claw 28a swings radially outward and protrudes, the swing arm 28 engages with the lock groove 26 on the casing 14 side. The swing arm 28 meshes with the lock groove 26 inclined in the webbing winding direction, thereby locking the rotation of the belt reel 12 in the pulling direction and allowing the belt reel 12 to rotate in the winding direction. The swing arm 28 is provided with a guide protrusion 29 that protrudes in the direction of the lock operation drum 23.

The lock actuating drum 23 has a plurality of clutch teeth 32 projecting from the outer peripheral surface, and a cam hole 31 inclined with respect to the normal direction is provided on the disc surface in the central region so as to penetrate in the plate thickness direction. Yes. A guide projection 29 of the swing arm 28 is slidably fitted into the cam hole 31.
When the belt reel 12 (locking base 27) rotates relative to the lock operation drum 23 in the webbing pull-out direction, the guide protrusion 29 causes the lock claw 28a of the swing arm 28 to move in the radial direction by the guide action of the cam hole 31. Project outward. Thus, when the lock claw 28a of the swing arm 28 protrudes radially outward, the lock claw 28a is engaged with the lock groove 26 on the casing 14 side (locked). Further, from this state, when the belt reel 12 rotates relative to the lock operation drum 23 in the webbing take-up direction, the lock claw 28a of the swing arm 28 is similarly pulled back radially inward by the guide action by the cam hole 31. Thus, when the lock claw 28a of the swing arm 28 is pulled back inward in the radial direction, the engagement of the lock claw 28a with the lock groove 26 is released (the locked state is released).

  A centrifugal arm 33 is swingably attached to the disk surface of the lock operation drum 23. The centrifugal arm 33 is composed of a mass body that is greatly influenced by centrifugal force, and is attached to a position spaced from the rotation center of the lock operation drum 23 so as to be swingable. The centrifuge arm 33 is provided with a lock claw 34 on the arm tip side, receives a centrifugal force according to the rotation of the lock operation drum 23, and swings the lock claw 34 side outward in the radial direction. A biasing spring 35 is provided between the lock actuating drum 23 and the centrifugal arm 33 to urge the lock claw 34 side of the centrifugal arm 33 in the radially inward direction of the lock actuating drum 23 at all times.

  The retainer 24 is provided therein with a bearing structure (not shown) that rotatably supports the reel shaft 12a of the belt reel 12 and the shaft portion of the lock operation drum 23, and faces the outer peripheral side of the lock claw 34 of the centrifugal arm 33. A clutch tooth (not shown) having an internal tooth structure is provided. When the centrifugal arm 33 swings outward in the radial direction due to the centrifugal force, the lock claw 34 of the centrifugal arm 33 meshes with the clutch teeth of the retainer 24. The lock actuating drum 23 is thus locked in rotation, and when the webbing 5 is about to be pulled out from this state (the belt reel 12 is about to rotate in the webbing pull-out direction), as described above, the lock claw of the swing arm 28 is locked. 28a is engaged with the lock groove 26 on the casing 14 side (emergency lock mechanism 22 is locked).

In addition, a vehicle sensor 37 is provided at a position below the lock actuating drum 23 in the retainer 24 to operate the locking claw 36 by detecting the deceleration (acceleration) and inclination of the vehicle. In the vehicle sensor 37, a sensor weight 45 is disposed in a housing portion surrounded by a sensor case 38 and a sensor cap 39, and a locking claw 36 is integrally attached to the sensor weight 45. The sensor weight 45 swings according to the acceleration and inclination of the vehicle, and engages the locking claw 36 with the clutch teeth 32 of the lock operation drum 23 when the sensor weight 45 swings more than a specified amount.
Thus, when the locking claw 36 is engaged with the clutch tooth 32, the rotation of the lock operation drum 23 is locked. Accordingly, when the webbing 5 is to be pulled out in this state, the lock claw 28a of the swing arm 28 is engaged with the lock groove 26 on the casing 14 side (the emergency lock mechanism 22 is locked).

Here, after the emergency lock mechanism 22 locks the rotation of the belt reel 12 in the webbing pull-out direction as described above, the locked state is released when the belt reel 12 is rotated more than a predetermined amount in the webbing take-up direction. The That is, when the belt reel 12 rotates in the webbing take-up direction with the rotation of the lock operation drum 23 stopped, the relative positional relationship between the belt reel 12 and the lock operation drum 23 is returned to the initial position. The lock claw 28a of the swing arm 28 is pulled back by the guiding action of the cam 29 and the cam hole 31, and as a result, the engagement with the lock groove 26 is released (the emergency lock mechanism 22 is unlocked).
The operation in the webbing winding direction of the belt reel 12 for unlocking is basically performed by the driving force of the motor 10. Hereinafter, “unlocking” means unlocking by the motor 10.

FIG. 2 is a block diagram showing the function of the controller 21 that is executed when the emergency lock mechanism 22 is unlocked.
As shown in the figure, the controller 21 includes a low-speed winding means 50 that drives the motor 10 at a first low speed (constant speed) in the webbing winding direction when the emergency lock mechanism 22 is unlocked, and the motor 10. Is provided at a high speed second speed (constant speed) in the webbing take-up direction, and a current detection means 52 for detecting the energization current of the motor 10 is provided. The controller 21 first drives the motor 10 by the low-speed take-up means 50 when the lock is released. When the energization current of the motor 10 detected by the current detection means 52 exceeds a predetermined value, the motor 21 is at that time. 10 driving is switched to driving by the high-speed winding means 51.
At the time of unlocking, the controller 21 manages the total winding time of the belt reel 12 (motor 10) from the start of unlocking. When the total winding time reaches a predetermined time, the winding drive of the motor 10 is performed. Is supposed to stop. Here, the predetermined time until the winding drive of the motor 10 is stopped is set to a time when the emergency lock mechanism 22 is unlikely to be locked again after the unlocking is started.

Hereinafter, an example of the control including the unlocking operation of the seat belt device 1 will be described based on the flowcharts of FIGS.
FIG. 4 shows a main flow by the controller 21, FIG. 4 shows a flow of the emergency winding process S102 in the main flow, and FIG. 5 shows an emergency lock mechanism release process S104 in the main flow. Yes.
In step S101 of the main flow shown in FIG. 4, is occupant restraint by the seat belt device 1 required based on signals from the longitudinal acceleration sensor 40, the lateral acceleration sensor 41, the yaw rate sensor 42, other controllers, and the like? It judges whether or not, and proceeds to the next emergency winding process S102 only in the case of Yes. In the following steps, the signals from the longitudinal acceleration sensor 40, the lateral acceleration sensor 41, the yaw rate sensor 42, other controllers, etc. are actually used to determine whether or not the restraint is necessary or to determine whether to release the lock as in step S101. In step S102 and subsequent steps, an example in which only the longitudinal acceleration sensor 40 is used will be described.

In the emergency winding process S102, the current winding position of the webbing 5 (rotational position of the belt reel 12) and the acceleration acting on the vehicle are detected from the detection signals of the rotation sensor 11 and the longitudinal acceleration sensor 40 in step S201 shown in FIG. G is read, and the maximum acceleration Gmax from the start of the emergency winding process S102 is stored (updated), and the motor 10 is energized with current I (initially a specified initial current) to wind the webbing 5 To do.
Subsequently, in step S202, it is determined whether or not the current winding position X of the webbing 5 read in step S201 is not equal to the target winding position X1, and if Yes (not equal) here, step S203 is determined. In the case of No, the process proceeds to step S206.
In step S206, it is determined whether or not occupant restraint by the webbing 5 is necessary based on the current acceleration G acting on the vehicle. If yes, the process returns to step S201, and if no, The emergency winding process S102 is terminated and the process returns to the main flow.
In step S203, it is determined whether or not the current winding position X of the webbing 5 is smaller than the target winding position X1, and if Yes, that is, if it is smaller than the target winding position X1, in step S204. The energizing current I for the motor 10 is increased by a minute amount ΔI and the process proceeds to step S206. In the case of No, that is, when larger than the target winding position X1, the energizing current I for the motor 10 is reversed by a minute amount in step S205. ΔI is decreased and the process proceeds to step S206.
Therefore, in this emergency winding process S102, the energization current I of the motor 10 is controlled so that the winding position X of the webbing 5 always approaches the target winding position X1, and this control continues until the vehicle state is stabilized. Is done.

  When the emergency winding process S102 ends and the process proceeds to step S103 in FIG. 4, the maximum acceleration Gmax in the emergency winding process S102 is equal to or greater than the lock start acceleration G1 (acceleration at which the vehicle sensor 37 operates) of the emergency lock mechanism 22. In the case of Yes, the process proceeds to the emergency lock mechanism release processing S104. In the case of No, the process proceeds to Step S105.

In the emergency lock mechanism release processing S104, the motor 10 is rotated in the webbing take-up direction at a low first speed in step S301 shown in FIG. That is, at this time, the rotation speed of the motor 10 is calculated based on the detection signal of the rotation sensor 11, and the energization current to the motor 10 is controlled so that the rotation speed becomes a low first speed.
Subsequently, in step S302, it is determined whether or not the elapsed time T from the start of the emergency unlocking process 104 is equal to or longer than the predetermined time T1, and if the answer is YES, the emergency lock mechanism releasing process S104 is terminated. In the case of No, the process proceeds to step S303.
In step S303, it is determined whether or not the energization current I for the motor 10 is equal to or greater than the threshold current I1. If yes, the process proceeds to step S304. If no, the process returns to step S301. That is, the tension applied to the webbing 5 after reaching the first speed by the motor 10 at the first speed reaches a certain level of force (a force corresponding to the motor torque when the motor 10 is energized with the threshold current I1). Until then, the motor 10 is rotated at the first speed.
In step S304, the rotational speed of the motor 10 is switched to the second high speed, and the webbing 5 is wound up at the second speed.
Subsequently, in step S305, it is determined whether or not the elapsed time T from the start of the emergency unlocking process 104 is equal to or longer than the predetermined time T1, and in the case of Yes, the emergency lock mechanism releasing process S104 is terminated. In the case of No, the process returns to step S304. In other words, the webbing 5 is continuously retracted by the motor 10 at the second speed until the predetermined time T1 elapses from the start of the emergency unlocking process 104, and the webbing 5 retraction is terminated when the predetermined time T1 elapses.
Here, the predetermined time T1 is the total winding time of the webbing 5 at the time of unlocking, and this predetermined time T1 is unlikely to be locked again by the emergency lock mechanism 22 after the unlocking is started as described above. Set to time. Therefore, after the emergency lock mechanism release processing S104 is finished, the possibility that the emergency lock mechanism 22 is locked again becomes extremely small.

  When the emergency lock mechanism release processing S104 is finished and the routine proceeds to step S105 in FIG. 4, in step S105, the motor 10 is reversely driven for a short time to turn off the clutch 20, and the motor 10 and the belt reel 12 are shut off. And return.

  As described above, when the emergency lock mechanism 22 is unlocked, the seat belt device 1 first rotates the motor 10 at the first low speed in the webbing take-up direction, and tightens the occupant to advance the webbing 5. Since the driving speed of the motor 10 is switched to the second high speed when the tension of the belt 10 increases, the webbing 5 starts to be wound up without giving a sudden pull-in feeling to the occupant at the initial stage of unlocking. The webbing 5 can be quickly drawn to the unlocking position from the point of time when it is gradually felt that the unlocking has started. For this reason, when this seatbelt apparatus 1 is employ | adopted, the emergency lock mechanism 22 can be cancelled | released reliably, without giving a passenger | crew a sense of incongruity.

  In the case of the seat belt device 1, the rotational speed of the motor 10 changes when the lock is released, but both the first half and the second half of the winding process of the motor 10 are maintained at a constant speed. This contributes to reducing discomfort.

  Further, in the seat belt device 1 of this embodiment, the motor 10 is driven by the low speed winding means 50 at the initial stage of unlocking, the tension of the webbing 5 is increased, and the detected current value by the current detecting means 52 is Since switching to driving of the motor 10 by the high-speed take-up means 51 is performed when the predetermined value or more is reached, the emergency lock mechanism 22 is surely released without giving a sense of incongruity to the occupant with a simple configuration. I can do it.

  Further, in the seat belt device 1 of this embodiment, the total winding time of the webbing 5 after starting the unlocking operation is managed, and a predetermined time T1 with a low possibility that the emergency lock mechanism 22 is locked again has elapsed. At the time, the driving of the motor 10 is stopped. For this reason, after the unlocking operation of the emergency lock mechanism 22 is completed, the emergency lock mechanism 22 is locked again, and the problem that the lock operation and the unlock operation are frequently repeated can be eliminated.

  In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary.

DESCRIPTION OF SYMBOLS 1 ... Seat belt apparatus 5 ... Webbing 10 ... Motor 12 ... Belt reel 21 ... Controller (control apparatus)
22 ... Emergency lock mechanism 50 ... Low speed winding means 51 ... High speed winding means 52 ... Current detection means

Claims (3)

A belt reel wound with webbing,
When the vehicle behavior becomes unstable, the rotation of the belt reel in the webbing pull-out direction is mechanically locked, and the lock is automatically released by the rotation of the belt reel in the webbing winding direction by a predetermined amount or more. Emergency locking mechanism;
A motor for applying a rotational driving force to the belt reel;
In a seat belt device provided with a control device for controlling the motor,
The controller drives the motor at a low speed in the webbing take-up direction when the emergency lock mechanism is unlocked, and switches the driving speed of the motor to a high speed when the webbing tension exceeds a predetermined value. A seat belt device characterized by the above. The control means includes
Low-speed winding means for driving the motor at a first low speed in the webbing winding direction;
High-speed winding means for rotating the motor in the webbing winding direction at a high-speed second speed;
Current detecting means for detecting an energization current of the motor,
When the emergency lock mechanism is unlocked, the motor is driven by the low-speed winding means, and when the current detection means detects a current value greater than or equal to a predetermined value, the motor is driven by the high-speed winding means. The seat belt device according to claim 1, wherein the seat belt device is switched to.   The control means stops the winding operation of the motor when the total winding time of the webbing when the emergency locking mechanism is unlocked reaches a predetermined time when the emergency locking mechanism is less likely to lock again. The seat belt device according to claim 2, wherein

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