JP2008044469A - Vehicle seat belt device - Google Patents

Abstract

In a vehicle that reduces power consumption due to wasteful energization by stopping control of a belt pull-out prevention operation by a motor when a lock mechanism is activated and a lock state occurs in a vehicle emergency or running state instability A seat belt device is provided.
A vehicle seat belt apparatus includes a belt reel and a motor that pulls the belt and winds the belt around the belt reel, and further includes a vehicle running state determination unit and a predetermined inclination or acceleration on the vehicle body. A lock mechanism 100 that prevents rotation of the belt reel in the pull-out direction when acted, a lock state determination unit 61 that determines an operation state of the lock mechanism, and a control device 26 that controls the amount of current supplied to the motor. This control device reduces the energization amount to the motor 23 when the signal output from the lock state determination is the lock effective signal.
[Selection] Figure 5

Description

  The present invention relates to a vehicle seat belt device, and more particularly to a vehicle seat belt device that stops a control operation for occupant protection restraint when a lock operation is performed by a lock mechanism.

  With regard to seat belt devices equipped to protect occupants in vehicle seats, in recent years, a technology that suppresses posture changes by restraining occupants with belts in an emergency or when running conditions are unstable has been put into practical use. Has been.

  As a prior art disclosing a seat belt device, there are systems described in Patent Documents 1 and 2 below. Patent Document 1 discloses an occupant restraint protection system that performs control in consideration of the situation of the host vehicle, and more efficiently performs restraint protection for the occupant. Patent Document 2 discloses an occupant restraint protection system in which a pretensioner of a seat belt device is operated to effectively protect an occupant when a side slip of a vehicle body or idling of a driving wheel occurs during traveling. .

Further, in a vehicle seat belt device, a lock mechanism is provided that activates a vehicle sensor to prevent the belt from being pulled out in an emergency. As a prior art document related to the lock mechanism, there is Patent Document 3 which discloses a method of releasing the lock state when the lock mechanism is activated to generate a lock state. In the technique disclosed in Patent Document 3, in order to release the locked state after operating the reversible belt pretensioner for tightening the belt, the belt reel lock mechanism satisfies a predetermined release condition. Until unlocked, and then release the lock.
JP 2004-291967 A JP 2001-122081 A Japanese Patent No. 36552683

  According to the seat belt device of a vehicle, in order to prevent the belt from being pulled out so as to protect the occupant when the vehicle is in an emergency or when the running state is unstable, the motor is energized and driven in the pull-out preventing direction in the retractor. Also, in the event of a vehicle emergency, the lock mechanism attached to the retractor may operate depending on the situation. When the lock mechanism is activated and the belt reel is engaged in an emergency of the vehicle, the belt reel is fixed and the belt does not rotate in the pull-out direction. Under such circumstances, separately controlling the belt pull-out prevention direction with the seat belt device consumes useless power.

  Further, when the motor is operated in addition to the operation of the lock mechanism in the case of an emergency of the vehicle or the like, the belt pull-out can be stopped by the lock operation of the lock mechanism and the operation of the motor, so that the performance of cushioning may be reduced. is there.

  In view of the above problems, the object of the present invention is to stop the control of the belt withdrawal preventing operation by the motor in the retractor when the lock mechanism is activated and the locked state is generated in the event of an emergency of the vehicle or when the running state is unstable. Another object of the present invention is to provide a vehicle seat belt device capable of reducing power consumption due to wasteful energization, saving power and preventing deterioration.

  In order to achieve the above object, a vehicle seat belt apparatus according to the present invention is configured as follows.

  A seat belt device for a first vehicle (corresponding to claim 1) is an electric pre-comprising a belt reel that winds a belt and a motor that drives the belt reel to retract the belt and wind it on the belt reel. A tensioner, and further, a traveling state determination means for determining that the traveling state of the vehicle has changed to a predetermined state; and rotation of the belt reel in the pull-out direction when a predetermined inclination or acceleration acts on the vehicle body of the vehicle. A lock mechanism for blocking, a lock operation determination means for determining an operation state of the lock mechanism, and a control means for controlling an energization amount to the motor based on a signal output from the traveling state determination means. The control means drives the motor to be energized by a predetermined method when the signal output from the traveling state determination means is input, and outputs the signal to the motor when the signal output from the lock operation determination means is a lock effective signal. Reduce the amount of electricity.

  In the vehicle seat belt device described above, when a lock mechanism including a vehicle sensor (a lock mechanism that is sensitive to acceleration) is activated in the event of an emergency of the vehicle, the amount of current supplied to the motor for pulling in the belt is reduced. It is determined whether or not the lock mechanism is operated in the vehicle seat belt device that performs the holding control for protecting the occupant at a predetermined belt winding position, and the restraint protection control by the motor operation is stopped when the lock mechanism is activated. As a result, it is possible to optimize the motor energization amount, eliminate waste of power consumption, and prevent deterioration of the motor. Further, since it is possible to prevent the motor torque from opposing the belt pulling-out operation, it is possible to improve the buffering property.

  In the seat belt device of the second vehicle (corresponding to claim 2), in the above configuration, the control unit preferably energizes the motor when the lock valid signal output from the lock operation determination unit continues for a predetermined time. Stop.

  The seat belt device of the third vehicle (corresponding to claim 3) preferably has a winding position detecting means for detecting the winding position of the belt reel in the above configuration, and the winding position detecting means is a predetermined position. When the above winding is detected, the driving by the predetermined method is resumed.

  In the seat belt device for a fourth vehicle (corresponding to claim 4), preferably, the determination by the lock operation determining means is effective when the traveling state determining means detects a change in the traveling state. Sometimes, energization of the motor is prohibited.

  According to the present invention, in a vehicle seat belt device having a lock mechanism, when the lock mechanism is activated and the belt is prevented from being pulled out in an emergency of the vehicle, the motor energization for preventing the retractor from being pulled out is performed. The amount can be reduced or stopped, wasteful energization at the time of locking operation can be eliminated, and power saving and deterioration prevention can be achieved.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows an installed state of a seat belt device in a driver's seat, etc. FIG. 2 shows a main configuration of a seat belt retractor, and FIG. 3 shows an overall configuration of a control system for a seat belt device of a vehicle.

  In FIG. 1, a seat belt device 10 includes a belt (webbing) 13 that restrains the body of an occupant 11 to a seat 12. The belt 13 includes a belt portion 13 a that restrains the upper body of the occupant 11 and a belt portion 13 b that restrains the waist of the occupant 11. One end of the belt portion 13b is fixed to the vehicle body portion at the lower part of the passenger compartment by an anchor plate 14. The belt portion 13 a is folded back by a through anchor 15 provided near a shoulder of the occupant 11, and an end portion thereof is connected to a belt reel of the retractor 16. A tongue plate 17 is attached to the other common end of the belt 13. The tongue plate 17 is detachably attached to a buckle 18 fixed to the lower edge of the seat 12. The buckle 18 is provided with a buckle switch 19 that detects the connection of the tongue plate 17.

  FIG. 2 shows a main configuration of the seat belt retractor 16. The retractor 16 includes a belt reel (spindle) 22 that is rotatably provided in the housing 21 and a motor 23 that rotationally drives the belt reel 22. The belt reel 22 is coupled to the end of the belt portion 13 a of the belt 13, and the belt portion 13 a is wound around the belt reel 22. The shaft 22 a of the belt reel 22 is connected to the drive shaft 23 a of the motor 23 via a power transmission mechanism (gear mechanism) 24. The belt reel 22 is rotationally driven by a motor 23 via a power transmission mechanism 24. The retractor 16 includes a winding position detector 25 connected to the shaft 22a of the belt reel 22.

  The winding position detection unit 25 is preferably configured using a rotation angle sensor. For example, a magnetic sensor formed by combining a magnetic disk and two Hall ICs is used as the rotation angle sensor. The minimum resolution angle of the rotation angle sensor is, for example, 4 °, and is about 1.3 to 1.6 mm when converted into the belt length. As the winding position detection unit 25, a belt length sensor can be used instead of the rotation angle sensor.

  The winding position detection unit 25 detects the belt winding position by the belt reel 22 by detecting the rotation angle of the belt reel 22 with a rotation angle sensor. A detection signal output from the winding position detection unit 25 is input to the control device 26. The operation of the retractor 16 is controlled by the control device 26. The control device 26 controls the operation of the retractor 16 by controlling the energization amount of the drive current I1 supplied from the power source 27 to the motor 23 by the energization amount adjustment unit 28. The retractor 16 controlled by the control device 26 is configured as an electric pretensioner for maintaining the posture of the occupant 11. The occupant 11 who gets on the seat 12 is protected and restrained by the belt 13 in an emergency of the vehicle or when the running state is unstable, and the posture change is suppressed, and the desired safe state is maintained.

  Further, in the retractor 16 for the seat belt, a lock mechanism for preventing the belt portion 13a of the belt 13 from being suddenly pulled out at the other end portion of the belt reel 22 opposite to the shaft 22a when an emergency situation of vehicle traveling occurs. 100 is attached. The case where an emergency situation of vehicle travel occurs is a case where a predetermined inclination acts on the vehicle body or a predetermined acceleration acts on the vehicle body due to a collision, sudden braking, or the like. The locking mechanism 100 is a well-known device. The lock mechanism 100 is generally composed of a mechanism main body 101 and a vehicle sensor (V / S) 102. The mechanism main body 101 includes a ratchet wheel that is coupled to the shaft 22a and is rotatable in conjunction with the shaft 22a, a frame gear fixed to the housing frame, and a change in position. And a locking element that engages or disengages the frame gear. The vehicle sensor 102 includes a ball element (weight) and a lever element (actuator) on a sensor frame. When acceleration is generated in the vehicle body, the position of the ball element is changed in response, and the lever element is operated, and the lever element has a function of making an engagement state with the outer peripheral claw of the ratchet wheel.

  In the lock mechanism 100 described above, the locking element and the frame gear are not engaged in a normal state, and both are engaged in a locked state. Similarly, the outer peripheral claw of the ratchet wheel and the lever element of the vehicle sensor 102 are not engaged in the normal state, and both are engaged in the locked state.

  In the locking mechanism 100, the locking condition (in accordance with the regulations) by the vehicle sensor 102 is, for example, “locking at 50 mm or less or an arbitrary two-direction 27 ° inclination” at 0.45 G, and “25 mm or less at 0.7 G”. To lock in. " In addition, due to the variation in the mechanism, the conditions under which the vehicle sensor 102 can be unlocked have individual differences of about ± 5 mm in terms of the belt winding amount.

  Whether or not the lock mechanism 100 is in the locked state is determined by a lock state determination unit as described later.

  The above-described seat belt device 10 and the retractor 16 are devices on the driver's seat side, but a similar seat belt device and retractor are also provided on the passenger seat side. In the following, the “R side” is the driver seat side, and the “L side” is the passenger seat side.

  With reference to the block diagram of FIG. 3, the control system of the seat belt device 10 and the like will be described from the viewpoint of hardware.

  In FIG. 3, the control device 26 is constituted by a CPU. A block 30 including the control device 26 represents an electric pretensioner unit for holding the posture of the occupant 11 by a seat belt. The block 30 includes a power source 31, an in-vehicle network (CAN) communication unit 32, a rotation angle interface (rotation angle I / F) unit 33, and a communication unit 34 on the input side of the control device (CPU) 26, and on the output side thereof. An R-side motor drive control unit 35, an L-side motor drive control unit 36, and a recording unit 37 are provided. The recording unit 37 is a memory that stores data and a control program.

  On the input side of the block 30, a block showing the retractor 16 is provided as an example of a seat belt retractor. The retractor 16 includes a rotation angle interface (rotation angle I / F) unit 41 for transmitting a detection signal output from the winding position detection unit 25 described above to the control device 26. The rotation angle interface unit 41 is connected to the rotation angle interface unit 33 in the block 30 and sends a detection signal to the rotation angle interface unit 33. The retractor 16 is provided on each of the driver's seat side and the passenger seat side.

  The input side of the block 30 further includes an ACC (Adaptive Cruise Control) unit (control unit such as an obstacle detection device) 42, a VSA (Vehicle Stability Assist) unit (vehicle behavior stabilization control unit) 43, FI / AT ( A Fuel Injection / Automatic Transmission (44) unit, an SRS (Supplement Restraint System) unit (auxiliary restraint device unit) 45, and the like are provided. These input side elements include a vehicle running state detection unit such as a vehicle speed sensor. The ACC unit 42, the VSA unit 43, the FI / AT unit 44, and the like supply their output signals to the in-vehicle network communication unit 32 through the in-vehicle network 46. The SRS unit 45 includes an SRS control unit 45a that receives signals from the R-side buckle 47R and the L-side buckle 47L, and a communication unit 45b. Here, the R-side buckle 47R corresponds to the buckle 17 on the driver's seat side, and the L-side buckle 47L is a buckle of a seat belt device equipped on the passenger seat side. Each signal output from the R side buckle 47R and the L side buckle 47L is a detection signal of a built-in buckle switch. When receiving a signal from the R side buckle 47R or the L side buckle 47L, the SRS control unit 45a transmits the signal to the communication unit 32 of the block 30 via the communication unit 45b. Further, the SRS unit 45 supplies a warning signal to the warning lamp 48 when the seat belt is not normally used when the vehicle is traveling.

  An R-side motor 51 and an L-side motor 52 are provided on the output side of the block 30. The R-side motor 51 is a driving motor for the seat belt device on the driver's seat side, and is disposed corresponding to the R-side motor drive control unit 35. The R-side motor drive control unit 35 controls the energization amount from the power source (+ V) 27 based on a control command signal from the control device 26 and supplies a drive current to the R-side motor 51. The block 53 is a grounding part. The L-side motor 52 is a driving motor for the seat belt device in the passenger seat, and is disposed corresponding to the L-side motor drive control unit 36. The L-side motor drive control unit 36 controls the energization amount from the power source (+ V) 54 based on a control command signal from the control device 26 and supplies a drive current to the L-side motor 52. The block 55 is a grounding part. The grounding portions 53 and 55 are grounding terminals that form part of the vehicle body.

  FIG. 4 is a functional block diagram conceptually showing the basic structure of the control system of the seatbelt device 10 according to the present embodiment. This control system includes, as main elements, the winding position detection unit 25 described above, a lock state determination unit 61 that determines a lock state by the lock mechanism 100, a vehicle travel state determination unit 62, and a seat belt device control unit 63. And a belt drive unit 64.

  Based on the change in the winding position of the belt reel 21 detected by the winding position detection unit 25, the lock state determination unit 61 determines whether the operation state of the lock mechanism 100 is the locked state. The lock state determination unit 61 is implemented as a functional unit by executing a lock state determination program in the control device (CPU) 26 described above.

  The vehicle travel state determination unit 62 is realized by the arithmetic processing function of the control device (CPU) 26 described above, and compares the detection signal supplied from the vehicle travel state detection unit with a reference value prepared in advance. A determination process is performed for the running state of the vehicle. The vehicle travel state determined by the vehicle travel state determination unit 62 includes an emergency operation state and a travel unstable state of the vehicle. The vehicle running state detection unit includes a plurality of various sensors such as a vehicle body longitudinal acceleration sensor, a vehicle body lateral direction (lateral direction) acceleration sensor, a vehicle speed sensor, a rudder angle sensor, a wheel speed sensor, a roll angle sensor, and a turning direction sensor. Including at least one of the following. These sensors may be in a state where they can be used at least via the in-vehicle network.

  The seat belt device control unit 63, the arithmetic processing function of the control device (CPU) 26 described above, an R side motor drive control unit 35, and an L side motor drive control unit 36 are configured. The belt driving unit 64 is the retractor 16 described above, and more specifically, the R side motor 51 and the L side motor 52 described above.

  Next, a characteristic operation control example of the seat belt device 10 implemented by the seat belt device control unit 63 and the like will be described based on the above-described configuration shown in FIG. 4 and the flowchart shown in FIG. In this example, an example of the R-side motor 51 will be described.

  When the occupant 11 sits on the seat 12, the belt 13 is wound around the body, and the tongue plate 17 is coupled to the buckle 18 (R side buckle 47R), the belt 13 is attached to the occupant 11 body. At this time, the buckle switch 19 is turned on (step S11).

  In the seat belt device 10 in which the belt is mounted on the body of the occupant 11, as a basic operation, personal information and setting information of the occupant 11 are acquired in step S12. It is assumed that the occupant information and the setting information are prepared in advance and stored in the recording unit 37 shown in FIG. Crew information includes gender information, physique information, and the like. The setting information is information set as a preference according to the intention of the occupant 11.

  In subsequent steps S13 and S14, based on the acquired occupant information and setting information, the R-side motor 51 is operated to perform the belt winding operation by the belt reel 22 (step S13). Adjustment is performed until it becomes satisfactory (step S14). If YES is determined in determination step S14, the reference position is stored (step S15). Data relating to the reference position is stored in the recording unit 37 described above.

  Next, in determination step S16, it is determined whether or not there is a change in the traveling state of the vehicle. If the determination in step 16 is NO, the control operation flow ends immediately. If the determination is YES, step S17 and subsequent steps are executed.

  The determination step S16 for confirming a change in the traveling state of the vehicle is periodically executed while the vehicle is traveling and the appropriate holding operation control of the seat belt device 10 is required.

  The determination in the determination step S16 is performed by the vehicle travel state detection unit 61 and the vehicle travel state determination unit 62. Various contents of the vehicle running state determined in the determination step S16 are included. “Vehicle running state” includes, for example, a change in normal driving state such as a slightly large steering operation / accelerator operation, in addition to an emergency state such as skidding and sudden deceleration. There is also a traveling state in which the occupant is swung from side to side. For example, when the lateral acceleration becomes greater than or equal to a predetermined value, when a steering operation is greater than or equal to a predetermined value, or when a wheel is idling during a turn. Note that the steering operation described above includes not only an occupant's operation but also a change in driving direction due to automatic steering and external force.

  When it is determined in the determination step S16 that "the vehicle driving state has changed" (YES), it usually corresponds to a seat belt restraint state set in advance corresponding to a change in the vehicle driving state. Although the target position is set, in the present embodiment, it is determined whether or not emergency restraint is necessary before setting the target position (step S17).

  If YES in determination step S17, it is determined whether lock mechanism 100 is in an operating state based on the determination content of lock state determination unit 61 (determination step S18). If YES in determination step S18, the control is terminated. If NO, a restraining operation for emergency restraint is executed (step S19), and then the control is terminated.

  If NO in the determination step S17, the process proceeds to step S20, and normal target position setting control is performed. In step S20, a target position corresponding to a seat belt restraint state set in advance corresponding to a change in the running state of the vehicle is set. In a normal case, since the running state of the vehicle becomes unstable and an emergency state occurs, the target position is set in the direction of increasing the belt restraint. When the target position is set in step S20, the motor holding current for controlling the winding operation of the R-side motor 51 is determined so as to correspond to the target position.

  In the next step S21, control of the holding current for changing the belt winding amount by the R-side motor 51 is started.

  As a basic operation example of the seat belt device 10, when holding control is executed, the R-side motor 51 is driven with a required energization amount, whereby the belt reel 22 winds up the belt portion 13 a of the belt 13, The belt portion 13 a is pulled into the retractor 16. By maintaining the required motor energization amount of the R-side motor 51 as a holding current, the belt winding amount is set at a desired target position.

  However, in the case of the control flow according to the present embodiment, after step S21, it is determined whether or not the lock mechanism 100 is activated (determination step S22).

  If NO in the determination step S22, the holding current for setting the target position is controlled in steps S23 to S26. Control is continued until the “current value” determined by the holding current that is the control target is consistent with the “target position” in a stable state.

  In determination step S23, it is determined whether or not the current value does not match the target position. When the current value does not coincide with the target position in the determination step S23 (YES), the process proceeds to the next determination step S24. In determination step S24, the magnitude relationship between the current value and the target position is determined. When the current value is smaller than the target position, the motor energization amount is increased (step S25), and when the current value is larger than the target value, the motor energization amount is decreased (step S26). Thereafter, the process proceeds to determination step S27.

  Further, when the current value matches the target position in the determination step S23 (NO), the process immediately proceeds to determination step S27.

  If YES in the determination step S22, the lock mechanism 100 has already been locked, and the rotation of the belt reel 22 is blocked and fixed. Therefore, the holding current control is purposely set to the target position. There is no need to do. Therefore, a process of reducing or stopping the motor energization amount is performed (step S28). In principle, it is preferable to reduce the motor energization amount, but when the lock operation state by the lock mechanism 100 continues for a predetermined time, it is preferable to stop energization of the motor 23. As a result, unnecessary power consumption is surely prevented, and even if the retractor 16 is rotated in the retracting direction immediately after the motor energization is reduced and the locked state by the lock mechanism 100 is released, a sudden belt The passenger | crew 11 can be hold | maintained appropriately, without accept | permitting extraction.

  Further, when the vehicle traveling state determination unit 62 determines that the traveling state has changed, the motor 23 is prohibited from being energized when the lock state determination unit 61 detects the lock operating state by the lock mechanism 100. You can also Even when urgent restraint is required, when the lock mechanism 100 is operating, no further pulling out of the belt 13 occurs, and in the seat belt device 10 according to the present embodiment, the belt 13 is slackened in advance. Since the holding control is performed in a state in which the motor is removed, no further motor energization is required.

  In a subsequent step, it is determined whether or not the position change of the winding position of the belt 13 is greater than or equal to a predetermined value (Xth) (determination step S29). If YES in determination step S29, the process proceeds to determination step S24 described above, and motor energization amount increase / decrease control is performed according to the relationship between the current value and the target position (steps S25, S26). That is, when the winding position detection unit 25 detects a winding amount equal to or greater than a predetermined value (Xth), the holding current control by energizing the motor 23 is resumed. In this case, assuming that the lock state by the lock mechanism 100 is released, the normal holding control is resumed. Thus, even if the lock mechanism 100 is unlocked, the occupant 11 can be appropriately held and restrained.

  On the other hand, if NO in the determination step S29, the process proceeds to the above-described determination step S27.

  In determination step S27, it is determined whether or not the running state of the vehicle is stable. If the running state is not stable, the process returns to step S22, and the above steps S22 to S29 are repeated. While the running state is not stable, in principle, when there is no lock operation by the lock mechanism 100, control is performed so that the current value matches the target position. When there is a lock operation by the lock mechanism 100, the motor energization amount is reduced or stopped, and unnecessary holding control is substantially stopped to prevent wasteful power consumption.

  When it is determined in the determination step S27 that the traveling state is stable, the process proceeds to the next determination step S30. In the determination step 30, it is determined again whether or not the lock mechanism 100 is operating in the retractor 16 of the seat belt device 10. When the lock mechanism 100 is not operated, the process proceeds to the end terminal. When the lock mechanism 100 is operated, the process proceeds to the end terminal after executing the lock release control (step S31). The unlocking control in step S31 is performed by reversing the motor 23.

  When the vehicle is traveling and proper operation control of the seat belt device 10 is necessary, the above control process is continued.

  As described above, the electric pretensioner using the R-side motor 51 is configured. With this electric pretensioner, the position and posture of the occupant 11 are properly maintained, and when the lock mechanism 100 is activated and the belt reel 22 is fixed, the amount of current supplied to the motor 23 is reduced or stopped, Useless power consumption is prevented and motor deterioration is prevented.

  The configurations, shapes, sizes, and arrangement relationships described in the above embodiments are merely schematically shown to the extent that the present invention can be understood and implemented. Therefore, the present invention is not limited to the described embodiments, and can be variously modified without departing from the scope of the technical idea shown in the claims.

  INDUSTRIAL APPLICABILITY The present invention is a seat belt device for a vehicle equipped with a lock mechanism, and is used to eliminate unnecessary power consumption by reducing the amount of electric current supplied to the motor when the lock mechanism is locking when the vehicle is running. The

It is a side view which shows the mounting state of the seatbelt apparatus in a vehicle. It is a figure which shows the principal part structure of the retractor of the seatbelt apparatus which concerns on embodiment of this invention. 1 is a block diagram illustrating an overall configuration of a control system for a seat belt device according to the present embodiment. It is a block diagram which shows the principal part structure of the control system of the seatbelt apparatus which concerns on this embodiment. It is a flowchart which shows the characteristic control flow of the seatbelt apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Seat belt apparatus 11 Passenger 16 Retractor 22 Belt reel 23 Motor 25 Winding position detection part 26 Control apparatus 61 Lock state determination part 62 Vehicle travel state determination part 63 Seat belt apparatus control part 100 Lock mechanism 101 Mechanism main body part 102 Vehicle sensor

Claims (4)

A vehicle seat belt apparatus including an electric pretensioner configured by a belt reel that winds a belt, and a motor that drives the belt reel to retract the belt and wind the belt reel,
Traveling state determining means for determining that the traveling state of the vehicle has changed to a predetermined state;
A lock mechanism for preventing rotation of the belt reel in the pull-out direction when a predetermined inclination or acceleration is applied to the vehicle body;
Lock operation determination means for determining an operation state of the lock mechanism;
Control means for controlling an energization amount to the motor based on a signal output from the running state determination means,
The control means drives the motor to be energized by a predetermined method when a signal output from the traveling state determination means is input, and when the signal output from the lock operation determination means is a lock effective signal A seat belt device for a vehicle, wherein an amount of current supplied to the motor is reduced.   2. The vehicle seat belt device according to claim 1, wherein the control means stops energization of the motor when the lock effective signal output from the lock operation determination means continues for a predetermined time.   A winding position detecting means for detecting a winding position of the belt reel is provided, and when the winding position detecting means detects a winding of a predetermined level or more, the driving in the predetermined method is resumed. Item 3. The vehicle seat belt device according to Item 1 or 2.   4. When the travel state determination unit detects a change in the travel state, if the determination by the lock operation determination unit is valid, energization of the motor is prohibited. The vehicle seat belt device according to claim 1.

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