JP5504300B2 - Seat belt device - Google Patents

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, a device that winds a webbing and holds a position with a motor is known. In this seat belt device, a driving motor is connected to a reel around which a webbing is wound via a clutch which is a connecting / disconnecting means. In this seat belt device, when the webbing is not taken up or held by the motor, the clutch is maintained in the disengaged state. In an emergency or when the webbing is taken up, the clutch is in the connected state. Transmits motor torque to the reel.

  In this type of seat belt device, the motor and the reel are connected when triggered by rotation of the motor in one direction (webbing take-up direction), and the connection between the motor and reel is disconnected when triggered by the reverse rotation of the motor. A contact means (clutch mechanism) is used (see, for example, Patent Document 1).

  In the seat belt device described in Patent Document 1, when the connection / disconnection means is switched to the interruption state, the rotation speed of the motor is changed according to the load generated in the connection / disconnection means, thereby suppressing the generation of abnormal noise. It is like that. That is, in this seat belt device, when the load on the connecting / disconnecting means is small, the rotation speed of the motor is lowered, and the occurrence of noise due to the operation part of the connecting / disconnecting means rotating at a high rotation is prevented. .

JP 2008-179260 A

  By the way, in recent years, electronic control devices (electronic control systems) mounted on vehicles tend to increase more and more. For this reason, currently, a plurality of electronic control devices mounted on a vehicle are connected to each other by an in-vehicle communication system (for example, CAN), and various signals such as sensors are mutually shared. ing.

  Even in the above-described seat belt device, for example, a situation in which a front detection device or the like connected to another electronic control device is used through an in-vehicle communication system can be considered. In this case, if a communication failure occurs in the in-vehicle communication system after the seat belt device starts to pull in the webbing and hold the position by receiving a signal from the front detection device, etc., the webbing is pulled in and the position is released properly. It becomes difficult to do at the timing. In other words, if an appropriate signal is not input through the in-vehicle communication system, the passenger restraint due to webbing cannot be promptly released even if the emergency state is avoided. For this reason, there is a concern that the passenger may feel uncomfortable.

  Therefore, the present invention is intended to provide a seat belt device capable of releasing passenger restraint by webbing at an appropriate timing even when a communication failure occurs in an in-vehicle communication system.

The seat belt device according to the present invention employs the following configuration in order to solve the above problems.
The invention according to claim 1 is a reel that winds webbing (for example, the reel 12 of the embodiment), a motor that rotationally drives the reel (for example, the motor 10 of the embodiment), and between the motor and the reel. A connecting / disconnecting means (for example, connecting the motor and the reel in a connected state triggered by rotation in one direction of the motor, and disconnecting the motor and the reel triggered in reverse rotation of the motor) The emergency state determination unit (for example, implementation) that determines the emergency state of the vehicle based on the vehicle state information input via the clutch 20) of the embodiment and the in-vehicle communication system (for example, the in-vehicle communication system 53 of the embodiment). When the emergency state determination unit 55) and the emergency state determination unit determine that the emergency state is in an emergency state, the webbing is pulled in according to the emergency state at that time. Alternatively, the control unit (for example, the control unit 56 of the embodiment) that controls the motor so as to hold the position of the webbing and the vehicle state are detected, and the control signal is directly transmitted without going through the in-vehicle communication system. Communication fault detection for detecting a communication fault in the in-vehicle communication system and direct vehicle state detection means (for example, the brake switch 15, the accelerator sensor 16, the steering angle sensor 17, the YAW / G sensor 18 of the embodiment) output to the vehicle (For example, the communication failure detection unit 57 of the embodiment), and the control unit determines that the emergency state determination unit is in an emergency state, and the motor takes up the webbing or webbing When the communication failure detection unit detects a communication failure in the in-vehicle communication system after starting position holding, the detection signal of the direct vehicle state detection means Based on maintenance of the pull and position holding the webbing, or, is characterized in that to control the motor so as to perform the release.
Thus, when the communication failure detection unit detects a communication failure in the in-vehicle communication system after the motor starts pulling in the webbing or holding the webbing position in an emergency, the control unit is based on the detection signal of the direct vehicle state detection means. Controls the motor, and the webbing is pulled in and the position is maintained or released.

  According to a second aspect of the present invention, in the seat belt device according to the first aspect, the control means is a signal that means that the detection signal of the direct vehicle state detection means is that the vehicle has not escaped from the emergency state. In some cases, the motor is controlled to maintain the connection / disconnection device in a connected state.

  According to a third aspect of the present invention, in the seat belt device according to the first or second aspect, the control means is such that the detection signal of the direct vehicle state detection means indicates that the vehicle is out of the emergency state. In this case, the motor is controlled so that the connecting / disconnecting device is in a disconnected state.

  According to a fourth aspect of the present invention, in the seat belt device according to the third aspect, when the webbing is suddenly pulled out from the reel, or when the behavior of the vehicle changes greatly, the webbing drawer is mechanically locked. And an emergency lock mechanism (for example, the emergency lock mechanism 22 of the embodiment) that releases the locked state by rotating the reel in a winding direction from the locked state by a predetermined amount. The emergency state is determined by dividing it into a plurality of levels of urgency, and when the emergency status determination unit determines that the emergency lock mechanism is at a high level of urgency, the webbing is retracted. Then, when the communication failure detection unit detects a communication failure in the in-vehicle communication system, the direct vehicle state detection means at that time If the detection signal is a signal that means that the vehicle is to be released from the emergency state, the connecting / disconnecting means is disconnected after the reel is rotated by the predetermined amount in the winding direction to unlock the emergency lock mechanism. The motor is controlled so that the webbing position is maintained when the emergency state determination unit determines that the emergency level is low, and then the communication failure detection unit performs communication of the in-vehicle communication system. When a failure is detected, if the detection signal of the direct vehicle state detection means at that time is a signal that means that the vehicle is to be taken out of an emergency state, the connection / disconnection means is put into a cutoff state. The motor is controlled.

  According to the present invention, when the communication failure detection unit detects a communication failure of the in-vehicle communication system after the motor executes the pulling of the webbing or the position holding in an emergency, the control unit detects the direct vehicle state detection means. Since the motor is controlled based on the detection signal, the passenger restraint by webbing can be released at an appropriate timing regardless of the communication failure of the in-vehicle communication system. Therefore, according to the present invention, unnecessary passenger restraint due to webbing can be eliminated, and passenger comfort can be further enhanced.

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 of the control system of the seatbelt apparatus of one Embodiment of this invention. It is a disassembled perspective view of the emergency lock mechanism 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 is a diagram showing an overall schematic configuration of a seat belt device 1 according to the present invention, in which 2 is a seat on which an occupant 3 is seated. The seat belt device 1 of this embodiment is a so-called three-point seat belt device, 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. The tip of the webbing 5 is fixed to the vehicle body floor via an outer anchor 7 near the outside 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. Further, the seat belt device 1 automatically winds the webbing 5 by the electric motor 10 in an emergency, when the behavior change of the vehicle is large, or when the webbing 5 is stored in the retractor 4. . The motor 10 is controlled by a seat belt ECU 21.

FIG. 2 is a schematic configuration diagram of the seat belt device 1 for explaining the functions of the retractor 4 and the seat belt ECU 21.
As shown in FIG. 2, the retractor 4 has a webbing 5 wound around a reel 12 rotatably accommodated in a casing 14 (see FIG. 3; omitted in FIG. 2). The reel 12 is connected to a rotating shaft 10a of the motor 10 via a power transmission mechanism 13 including a clutch 20 (connecting / disconnecting means) so as to be able to be interlocked. The power transmission mechanism 13 decelerates the rotation of the motor 10 and transmits it to the reel 12. Further, the retractor 4 is provided with a return spring (not shown) that urges the reel 12 in the webbing take-up direction. When the reel 12 and the motor 10 are separated by the clutch 20, the tension by the take-up spring is applied to the webbing 5. It comes to work. The clutch 20 is switched between an on state and an off state, triggered by rotation of the motor 10 in the forward rotation direction (webbing winding direction) and rotation in the reverse rotation direction (webbing pull-out direction).

  Further, the retractor 4 is provided with a rotation sensor 11 (rotation position detecting means) for detecting the rotation position of the 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 a pair of magnetic disks that rotate integrally with the reel 12 and a pair of adjacently arranged outer peripheral edges of the magnetic disk. It consists of a Hall element and a sensor circuit that processes a detection signal of the Hall element, and a pulse signal processed by the sensor circuit is output to the seat belt ECU 21.

  In this case, the pulse signal input from the sensor circuit to the seat belt ECU 21 according to the rotation of the reel 12 is used to detect the rotation amount, rotation speed, rotation direction, and the like of the reel 12. In other words, the seat belt ECU 21 detects the amount of rotation of the reel 12 (the amount of webbing 5 pulled out) by counting the pulse signal, and calculates the speed of rotation (frequency) of the reel 12 by calculating the change speed (frequency) of the pulse signal. The winding / drawing speed of the webbing 5 is obtained, and the rotation direction of the reel 12 is detected by comparing the rising edges of the waveforms of both pulse signals.

On the input side of the seat belt ECU 21, in addition to the rotation sensor 11, a brake switch 15 that detects a brake operation by an occupant, an accelerator sensor 16 that detects an accelerator operation by the occupant, and a steering angle sensor that detects the presence or absence of steering. 17 and a YAY / G sensor 18 for detecting the yaw rate and acceleration acting on the vehicle are connected. The seat belt ECU 21 is connected to the following ECUs 50 to 52 through an in-vehicle communication system 53 such as a CAN (Controller Area Network).
<CMBS control ECU 50>
A CMBS (Collision Mitigation Brake System) ECU that detects a front obstacle such as a preceding vehicle by the millimeter wave radar 54 and automatically operates a brake according to an approach distance with the front obstacle.
<VSA control ECU 51>
ECU of VSA (Vehicle Stability Assist) system that controls the output of the engine and the braking force of the brake in an integrated manner to suppress disturbance in the behavior of the vehicle when the vehicle becomes unstable.
<Brake assist control ECU 52>
An ECU for a brake assist system that increases the braking force of the brake when a driver suddenly operates the brake.
In this embodiment, the millimeter wave radar 54 constitutes non-linear vehicle state detection means for outputting vehicle state information to the seat belt ECU 21 via the in-vehicle communication system 53, and includes the brake switch 15, the accelerator sensor 16, The steering angle sensor 17 and the YAY / G sensor 18 constitute direct vehicle state detection means for directly outputting vehicle state information to the seat belt ECU 21 without using the in-vehicle communication system 53.

Further, the seat belt ECU 21 determines the emergency state of the vehicle based on the vehicle state information (approach information to the front obstacle) transmitted from the CMBS control ECU 50 (millimeter wave radar 54) via the in-vehicle communication system 53. When the emergency state determination unit 55 and the emergency state determination unit 55 determine that it is an emergency state, the motor 10 is set so as to perform winding or position holding of the webbing 5 according to the emergency state at that time. A control unit 56 for controlling and a communication failure detection unit 57 for detecting a failure of the in-vehicle communication system 53 are configured.
In the case of this embodiment, the emergency state determination unit 55 performs the determination in two levels of urgency according to the approach distance to the front obstacle, and the control unit 56 determines the urgency level determined by the emergency state determination unit 55. The motor 10 is controlled in different modes according to the above. Specifically, in the case of a low level of urgency where the distance between the vehicle and the front obstacle is a certain degree, a torque is applied to the motor 10 so as to hold the webbing 5 in the drawing position (block the drawing). In the case of a high level of urgency at which the vehicle is closest to the front obstacle, the motor 10 is driven so as to pull in the webbing 5 by a predetermined amount and restrain the occupant.
Moreover, the communication failure detection part 57 monitors the signal state in the in-vehicle communication system 53, for example, and determines whether it is a failure based on the change (abnormality) of the signal state.

  By the way, in the retractor 4, when the webbing 5 is suddenly pulled out from the reel 12 (when the reel 12 is suddenly rotated in the webbing pull-out direction), or when acceleration or inclination exceeding a predetermined value occurs in the vehicle (the vehicle is An emergency lock mechanism 22 that mechanically locks the rotation of the reel 12 in the webbing pull-out direction is provided.

FIG. 3 is a diagram showing 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 and a spring case (not shown) that house the return spring are attached to one side wall 14A, and the other side wall 14B has A retainer 24 that supports a lock actuating drum 23 described later is attached. The side walls 14A and 14B on both sides are provided with a substantially circular hole 25, and a lock groove 26 inclined in the webbing take-up direction is formed on the inner periphery of the hole 25 of the other side wall 14B.

  A locking base 27 is provided at the other end of the reel 12, and a swinging arm 28 having a lock claw 28 a at the tip is attached to the outer peripheral edge of the locking base 27 so as to be swingable. When the tip end side of the swing arm 28 is pivoted radially outward and protrudes, the lock claw 28a meshes with the lock groove 26 on the casing 14 side. The lock claw 28a meshes with the lock groove 26 inclined in the webbing winding direction to lock the rotation of the reel 12 in the pull-out direction and allow the reel 12 to rotate in the winding direction. In addition, a guide pin 29 that protrudes toward the locking base 27 is provided at a position away from the swing center of the swing arm 28.

  The reel shaft 12a penetrates and projects at the axial center position of the locking base 27, and the lock operation drum 23 is fitted to the reel shaft 12a. The lock actuating drum 23 is fitted to the reel shaft 12a with a small frictional resistance. When the reel 12 rotates normally, the lock actuating drum 23 rotates integrally with the reel 12, and when a force in the opposite direction is applied to both, 12 relative to the set angle range.

  A long hole-shaped guide hole 31 into which the distal end portion of the guide pin 29 is inserted and engaged is formed in the outer peripheral edge portion of the lock operation drum 23. The guide hole 31 guides the guide pin 29 in a predetermined direction when the reel 12 rotates relative to the lock operation drum 23 in the webbing pull-out direction. ) Is displaced radially outward.

  Further, the lock operation drum 23 has a plurality of clutch teeth 32 formed on the outer peripheral surface, and a lock arm 33 is swingably attached to an end surface on the outer side in the axial direction. The lock arm 33 is made of a mass body that is affected 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 lock arm 33 is provided with a lock claw 34 on the distal end side of the arm, receives a centrifugal force according to the rotation of the lock operation drum 23, and swings the lock claw 34 side radially outward. A biasing spring 35 is provided between the lock actuating drum 23 and the lock arm 33 to urge the lock claw 34 side of the lock arm 33 in the radially inward direction of the lock actuating drum 23 at all times.

  The retainer 24 is fixed to the casing 14 so as to cover the front side and the periphery of the lock operation drum 23 and the lock arm 33. The retainer 24 is provided with a bearing structure (not shown) that rotatably supports the shaft portions of the reel 12 and the lock operation drum 23, and an internal tooth structure is not shown so as to face the outer peripheral side of the lock claw 34 of the lock arm 33. Clutch teeth are provided. The clutch teeth of the retainer 24 mesh with the lock claw 34 of the lock arm 33 when the lock arm 33 is subjected to centrifugal force and swings radially outward. As a result, the lock actuating drum 23 is locked in rotation. As a result, relative rotation with the reel 12 occurs, and the lock claw 28a of the swing arm 28 is displaced radially outward as described above. It will be engaged with the lock groove 26. Therefore, when the webbing 5 is about to be pulled out suddenly, the lock claw 28a of the swing arm 28 meshes with the lock groove 26 of the casing 14, so that the rotation of the reel 12 in the webbing pull-out direction is locked.

In addition, a vehicle sensor 37 that senses the acceleration of the vehicle and operates the locking claw 36 is provided at a lower portion in the retainer 24. 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 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 predetermined 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 reel 12 and the lock operation drum 23 rotate relative to each other. As a result, the lock claw 28a of the swing arm 28 meshes with the lock groove 26 of the casing 14, and the reel Twelve webbing pull-out directions are locked.

  The emergency lock mechanism 22 is released from the locked state when the reel 12 is rotated in the webbing take-up direction by a predetermined amount or more by the motor 10 after the rotation of the reel 12 in the webbing pull-out direction is locked as described above. The That is, when the reel 12 rotates in the webbing take-up direction with the rotation of the lock operation drum 23 locked, the relative positional relationship between the reel 12 and the lock operation drum 23 is returned to the initial position. When the relative positional relationship between the reel 12 and the lock operation drum 23 is returned to the initial position, the swing arm 28 is pivoted radially inward through the guide pin 29, and the engagement between the lock claw 28a and the lock groove 26 is released. Is done.

Hereinafter, an example of the control of the seat belt device 1 in an emergency will be described based on the flowchart of FIG.
In step S101, it is determined whether or not the emergency level determination unit 55 has determined the high degree of urgency. If the answer is Yes, the process proceeds to step S102. If the answer is No, the process proceeds to step S103.
In step S102, the motor 10 is driven in the webbing take-up direction so as to retract the webbing 5 by a predetermined amount (so-called pre-crash operation).
Subsequently, in step S104, it is determined whether or not a communication abnormality has occurred in the in-vehicle communication system 53 after the start of the pull-in control of the webbing 5, and in the case of Yes, the process proceeds to the next step S105, where Return in case.
In the case of No here, although omitted in the flowchart, when a danger avoidance completion signal is received from the CMBS control ECU 50 (millimeter wave radar 54) via the in-vehicle communication system 53, it will be described later. The passenger restraint by the webbing 5 is released by the same control as in steps S107 and S108.

In step S105, it is determined whether or not the acceleration detected by the YAW / G sensor 18 is a sufficiently small prescribed value G1 (for example, 0.24 g) and the brake switch 15 satisfies the OFF condition, If yes, the process proceeds to the next step S106. If no, the current control is continued. In other words, the current control is continued until the vehicle is avoided from the emergency state.
In step S106, it is determined whether or not any of the following conditions (a), (b), and (c) is satisfied.
(A) The accelerator sensor 16 is OFF.
(B) The rudder angle sensor 17 is OFF.
(C) The yaw rate detected by the YAW / G sensor 18 is a specified value Y1 (for example, 10 deg / s) or less.
If the determination in step S106 is Yes, the process proceeds to step S107. If No, the current control is continued. Here, the current control is continued until there is no situation where the risk avoidance behavior by the driver is predicted.

  In step S107, the reel 10 is rotated by a predetermined amount in the webbing winding direction by the motor 10, and the emergency lock mechanism 22 is unlocked. In the case of proceeding from step S101 to the pre-crash operation in step S102, the webbing 5 is about to be pulled out suddenly by a sudden braking operation, or a large acceleration (deceleration) acts on the vehicle. 22 operate together.

  In the next step S108, the motor 10 is driven in the reverse direction for a minute time, thereby disconnecting the clutch 20.

On the other hand, in step S103, it is determined whether or not the emergency state determination unit 55 has determined the low degree of urgency. If the answer is Yes, the process proceeds to step S109. If the answer is No, the process returns.
In step S109, the motor 10 is controlled so as to hold the drawing position of the webbing 5.
Subsequently, in step S110, after the position holding control of the webbing 5 is started, it is determined whether or not a communication abnormality has occurred in the in-vehicle communication system 53. If yes, the process proceeds to the next step S111. If it is, return.
In the case of No, although omitted in the flowchart, the same as step S108 is performed when a danger avoidance completion signal is received from the CMBS control ECU 50 (millimeter wave radar 54) via the in-vehicle communication system 53. The connection of the clutch 20 is cut off by the control.

  In step S111, it is determined whether or not any of the above conditions (a), (b), and (c) is satisfied in the same manner as in step S106. If yes, the process proceeds to step S108. In the case of No, the current control is continued. That is, here, the current control is continued until there is no situation where the risk avoidance behavior is predicted by the driver, and when there is no situation where the danger avoidance behavior is predicted, the process proceeds to step S108 and the motor 10 is driven in reverse. To disconnect the clutch 20.

  As described above, in this seat belt device 1, after the vehicle approaches a front obstacle and the pull-in control and the position holding control of the webbing 5 in an emergency are started, a communication failure occurs in the in-vehicle communication system 53. In this case, the control unit 56 of the seatbelt ECU 21 uses signals from the brake switch 15, the accelerator sensor 16, the steering angle sensor 17, the YAW / G sensor 18, and the like that are direct vehicle state detection means not via the in-vehicle communication system 53. Thus, since the motor 10 is controlled, the passenger restraint by the webbing 5 can be released at an appropriate timing regardless of the communication failure of the in-vehicle communication system 53.

  Specifically, in the seat belt device 1, when a communication failure occurs in the in-vehicle communication system 53 when the pull-in control of the webbing 5 is performed in a high-level emergency state, the YAW / G sensor 18 Based on the signal from the brake switch 15, it is determined whether or not the vehicle is in a situation to be avoided from the emergency state, and driving is performed based on the signals from the accelerator sensor 16, the steering angle sensor 17, and the YAW / G sensor 18. It is determined whether or not the danger avoidance behavior by the user is continued, and the motor 10 is controlled so as to continuously release the emergency lock mechanism 22 and disconnect the clutch 20 when these conditions are satisfied. Yes. For this reason, even when the signal of the millimeter wave radar 54 becomes unavailable due to a communication failure in the in-vehicle communication system 53, when the vehicle is avoided from the emergency state and the danger avoidance behavior by the driver is finished. The occupant restraint by the webbing 5 can be quickly released.

  Further, in this seat belt device 1, when a communication failure occurs in the in-vehicle communication system 53 when the position holding control of the webbing 5 is being executed in a low-level emergency state, the accelerator sensor 16 and the steering angle sensor 17. Based on the signal from the YAW / G sensor 18, it is determined whether or not the danger avoidance behavior is continued by the driver, and the motor 10 is controlled so that the clutch 20 is disconnected when the danger avoidance behavior is completed. Like to do. For this reason, even if the signal of the millimeter wave radar 54 becomes unavailable due to a communication failure of the in-vehicle communication system 53, the passenger can quickly reduce the passenger's lightness by the webbing 5 when the danger avoidance behavior by the driver is completed. The restraint can be released.

  Therefore, in this seat belt device 1, even when a communication failure of the in-vehicle communication system 53 occurs during the emergency pull-in control or position holding control of the webbing 5, the passenger restraint by the webbing 5 is performed at an appropriate timing. Therefore, the passenger does not feel uncomfortable due to unnecessary restraint by the webbing 5. For this reason, a passenger | crew's comfort can be improved more.

  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 10 ... Motor 12 ... Reel 15 ... Brake switch (direct vehicle state detection means)
16 ... Accelerator sensor (direct vehicle state detection means)
17 ... Rudder angle sensor (direct vehicle state detection means)
18 ... YAW / G sensor (direct vehicle state detection means)
20 ... Clutch (connection / disconnection means)
DESCRIPTION OF SYMBOLS 22 ... Emergency lock mechanism 53 ... In-vehicle communication system 55 ... Emergency state determination part 56 ... Control part 57 ... Communication failure detection part

Claims (4)

A reel for winding webbing,
A motor for rotationally driving the reel;
Interposed between the motor and the reel, the motor and the reel are connected when triggered by rotation of the motor in one direction, and the motor and reel are disconnected when triggered by rotation of the motor in the reverse direction Connecting and disconnecting means,
An emergency state determination unit that determines an emergency state of the vehicle based on vehicle state information input via the in-vehicle communication system;
When the emergency state determination unit determines that it is an emergency state, according to the emergency state at that time, the control unit that controls the motor to perform the webbing retraction or webbing position holding;
Direct vehicle state detection means for detecting a vehicle state and outputting a detection signal directly to the control unit without going through the in-vehicle communication system;
A communication failure detection unit for detecting a communication failure of the in-vehicle communication system,
The controller determines that the emergency state determination unit is in an emergency state, and after the motor starts winding the webbing or holding the webbing position, the communication failure detection unit When the communication failure is detected, the motor is controlled so as to maintain or release the webbing and maintain the position based on a detection signal of the direct vehicle state detection means. Belt device.   The control means controls the motor so as to maintain the connecting / disconnecting device when the detection signal of the direct vehicle state detecting means is a signal which means that the vehicle has not left the emergency state. The seat belt device according to claim 1.   When the detection signal of the direct vehicle state detection means is a signal that means that the vehicle is out of the emergency state, the control means controls the motor so that the connecting / disconnecting device is turned off. The seat belt device according to claim 1 or 2, wherein When the webbing is suddenly pulled out from the reel or when the behavior of the vehicle changes greatly, the webbing drawer is mechanically locked, and the reel is rotated by a predetermined amount in the winding direction from the locked state. An emergency lock mechanism for releasing the locked state;
The emergency state determination unit determines the emergency state of the vehicle by dividing it into multiple levels of urgency,
The controller is
When the emergency state determination unit determines that the emergency lock mechanism is at a high level of urgency, the webbing is pulled in, and then the communication failure detection unit detects a communication failure in the in-vehicle communication system. In this case, if the detection signal of the direct vehicle state detection means at that time is a signal that means that the vehicle is released from the emergency state, the reel is rotated by the predetermined amount in the winding direction, and the Controlling the motor so that the connecting / disconnecting means is shut off after unlocking the emergency lock mechanism;
When the emergency state determination unit determines that the degree of urgency is low, the webbing position is retained, and when the communication failure detection unit detects a communication failure in the in-vehicle communication system, then If the detection signal of the direct vehicle state detection means is a signal that means that the vehicle is to be removed from the emergency state, the motor is controlled so that the connection / disconnection means is put into a cutoff state. The seat belt device according to claim 3.

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