JP2008074270A - Seat belt device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat belt device for a vehicle that enables locking to be released without imparting an unnecessary tension to a passenger when releasing a locked state of a locking mechanism. <P>SOLUTION: The seat belt device 10 for a vehicle is provided with a pretensioner mechanism, which is composed of a belt reel 22 for winding a belt 13 and a motor 23 for driving the belt reel, a winding-position detection part 25 for detecting a winding position of the belt reel, a traveling-state determination part 62 for determining that a traveling state of a vehicle is changed into a prescribed state, and a control device 23 that controls a motor drive amount while controlling a conduction amount to the motor on the basis of a signal outputted from the traveling-state determination part so as to reduce the conduction amount or to stop conduction to the motor when the winding position reaches a prescribed value on the basis of a detection signal from the winding-position detection part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle seat belt device, and more particularly to a vehicle seat belt device that uses an electric pretensioner to release a locked state when a lock mechanism is locked in an emergency.

2. Description of the Related Art In recent years, a vehicle seat belt device is provided with a lock mechanism that activates a vehicle sensor to prevent the belt from being pulled out in an emergency or the like. As a method of releasing the lock state when the lock mechanism is operated and a lock state is generated, there is a method described in Patent Document 1 below. In the method described in Patent Document 1, 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 the unlocking operation is performed.
Japanese Patent No. 36552683

  According to the conventional unlocking method, when an event that is not taken into account when determining the unlocking condition, such as a tilt of the vehicle body due to an unexpected vehicle body state change such as puncture or suspension deformation, There is a possibility that an error occurs in the release condition and the release cannot be performed reliably. As a result, there is a possibility that the belt is pulled more than necessary in the belt pulling operation for releasing the locked state, and thus unnecessary tension is applied to the occupant.

  In view of the above problems, the object of the present invention is to enable unlocking without applying unnecessary tension to the occupant when the lock mechanism is activated and the locked state is generated. It is an object of the present invention to provide a vehicle seat belt device that can eliminate discomfort with respect to the vehicle.

  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 a vehicle seat provided with a pretensioner mechanism comprising a belt reel that winds the belt and a motor that drives the belt reel and pulls in the belt. A belt device, which is output from a winding position detecting means for detecting the winding position of the belt reel, a traveling state determining means for determining that the traveling state of the vehicle has changed to a predetermined state, and a traveling state determining means. The energization amount to the motor is controlled based on the signal to control the drive amount of the motor, and the energization amount is reduced when the winding position reaches a predetermined value based on the detection signal from the winding position detection means, or the motor And a control means for stopping energization.

  In the above vehicle seat belt device, the control means controls the motor drive amount based on the signal output from the traveling state determination means to control the motor drive amount, and based on the detection signal from the winding position detection means. When the winding position reaches a predetermined value, the energization amount is reduced or the energization to the motor is stopped. Therefore, when a lock mechanism such as a vehicle sensor (lock mechanism by acceleration) is operated, the lock state of the lock mechanism is changed. When releasing using an electric pretensioner, it becomes possible to release without applying unnecessary tension to the occupant when releasing the lock.

  The seat belt device of the second vehicle (corresponding to claim 2) preferably includes a lock mechanism for preventing rotation of the belt reel in the belt pull-out direction, and the control means unlocks the lock mechanism. In order to perform the above operation, there is a lock release means for driving the belt reel by a predetermined amount in the winding direction.

  In the third vehicle seat belt apparatus (corresponding to claim 3), in the above configuration, preferably, the predetermined value is a belt winding in a state in which the belt is adapted without slacking the occupant. A value obtained by adding a predetermined amount from the position in the belt drawing direction.

  According to the present invention, when the belt is locked by the lock mechanism in an emergency in the seat belt device of the vehicle, the motor energization amount is based on the output signal of the traveling state determination means when the lock state by the lock mechanism is released. By controlling the motor drive amount, and when the winding position reaches a predetermined value based on the detection signal from the winding position detection means, reducing the energization amount or stopping the energization to the motor, The pretensioner can be operated while leaving the necessary belt margin, and the lock can be released without applying unnecessary tension to the occupant.

  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 detector 25 is preferably configured as a rotation detector 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. Inside the control device 26, as a functional means, there is provided means for calculating a belt winding position based on position information regarding the belt 13 obtained by the winding position detection unit 25. 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 position / posture of the occupant 11.

  Further, in the seatbelt retractor 16, a lock mechanism 100 is attached to the other end of the shaft 22a of the belt reel 22 to prevent the belt portion 13a of the belt 13 from being pulled out suddenly when an emergency situation of vehicle travel occurs. The The lock mechanism 100 includes 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 and a lever element in a sensor frame. When undesirable acceleration occurs in the vehicle body depending on the unstable running state or behavior of the vehicle body, the position of the ball element changes and the lever element is operated, and the lever element is engaged with the outer claw of the ratchet wheel. It has a function to make.

  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.

  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 and stores data and a required control program to be described later.

  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 (including a behavior 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 functional configuration 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.

  The lock state determination unit 61 determines whether or not the operation state of the lock mechanism 100 is the lock state based on the change in the winding position of the belt reel 21 detected by the winding position detection unit 25. That is, when it is determined that the detection signal of the winding position detection unit 25 has not changed despite the motor 23 attempting to rotate the belt reel 22, the lock mechanism 100 is activated and locked. It is determined that it is in a state.

  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 running state detection unit includes a plurality of vehicle front-rear direction acceleration sensors, vehicle body left-right direction (lateral direction) acceleration sensors, vehicle speed sensors, rudder angle sensors, wheel speed sensors, roll angle sensors, turning direction sensors, and the like. It includes at least one of various sensors. 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 includes the arithmetic processing function of the control device (CPU) 26 described above, and an R side motor drive control unit 35 and an L side motor drive control unit 36. 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 first 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 configuration of the device shown in FIGS. 2 to 4 and the flowchart of FIG. . In this example, an example of the R-side motor 51 will be described.

  The flowchart shown in FIG. 5 is a control flow for releasing the locked state without applying unnecessary belt tension, that is, tension, to the occupant 11 when the lock mechanism 100 is activated and the locked state occurs in an emergency. Is shown.

  As a premise of the control flow shown in FIG. 5, it is assumed that normal seat belt mounting control is executed. That is, 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. Then, in the seat belt device 10, the control for removing the slack of the normal belt 13 and the holding control are performed, and the belt holding mounting operation that fits the body shape of the occupant 11 is executed. Further, as a basic operation example of the seat belt device 10, when an emergency (unstable traveling state or behavior) occurs during traveling of the vehicle, this is detected, and the R-side motor 51 is driven with a predetermined energization amount. As a result, the belt reel 22 winds up the belt portion 13 a of the belt 13 and pulls the belt portion 13 a into the retractor 16. Thereby, an electric pretensioner using the motor 23 is configured.

  Further, according to the seat belt mounting control unit 63 described above, the vehicle is based on a detection signal from the winding position detection unit 25 that detects the winding position of the belt reel 22 in a normal mounting state when the vehicle is traveling, and On the basis of a signal output from a vehicle travel state determination unit or the like that determines that the travel state of the vehicle has changed to a predetermined stable state, the amount of current supplied to the R side motor 51 is controlled to control the drive amount of the R side motor 51. Control. At this time, a detection signal from the winding position detection unit 25 is input, and based on this, the belt reel 22 is held and controlled at a predetermined winding position, and the occupant 11 is optimally held by the belt 13.

  In the above normal holding control, the belt reel 22 is rotated in the winding direction by a predetermined amount, and the occupant is restrained by the belt 13. At this time, while a certain amount of tension or tension acts on the belt 13, the belt 13 is prevented from being pulled out by a well-known motor reverse rotation prevention mechanism (not shown). At the same time, when the lock mechanism 100 is in the operating state, the tension is maintained even when the motor 23 is de-energized.

  Next, an operation for releasing the lock state when the lock mechanism 100 is locked will be described with reference to the flowchart shown in FIG.

  In the first determination step S11, it is determined whether or not there is a change in the running state. This determination process is executed by the vehicle running state determination unit 62. If NO in the determination step S11, the control is terminated because the lock mechanism 100 is not locked. In the case of YES in the determination step S11, it is assumed that the lock state is generated in the lock mechanism 100, and the process proceeds to the next processing step S12. In process step S12, energization control for energizing the motor 23, in this example, the R-side motor 51, is started.

  Thereafter, in the next determination step S13, is the current position relating to the winding position of the belt 13 obtained by the detection operation by the winding position detection unit 25 equal to or greater than a predetermined value, that is, a reference value (X0) set in advance? It is determined whether or not. If the current location is smaller than the reference value X0, the process proceeds directly to the next determination step S15. If the current location is greater than or equal to the reference value X0, that is, when the predetermined reference value is reached, processing step S14 is performed. Then, the process proceeds to determination step S15. In process step S14, it is executed to reduce or stop the energization amount to the motor. That is, when the winding position of the belt 13 reaches a predetermined value (reference value X0), the motor energization amount is reduced or stopped. The reference value X0 is preferably a value obtained by adding a predetermined amount from the belt winding position in a state in which the belt 13 in the fitted state is fitted to the occupant 11 without slackening.

  If it is determined at step S15 that the traveling state has not returned to the stable state (in the case of NO), the routine returns to step S13 and the above control procedure is repeated. If YES in determination step S15, that is, if the traveling state of the vehicle returns to a stable state, the process proceeds to next determination step S16.

  In the determination step 16, it is determined 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 (NO), the control is ended. When the lock mechanism 100 is operated, the lock release control (step S17) is executed and then the control is ended.

  According to the above control, when the lock mechanism 100 attached to the retractor 16 is locked in an emergency, the belt 13 is wound up by the electric pretensioner using the R-side motor 51 and the locked state is set. When attempting to release the belt, the upper limit value of the belt winding amount is determined based on the reference value X0, so that the belt 13 is wound while leaving a required belt pulling distance. As a result, when unlocking using the electric pretensioner based on the belt winding position, unlocking can be performed without applying unnecessary belt tension to the occupant 11.

  As described above, according to the control of the unlocking operation by the electric pretensioner in the seat belt device 10, the necessary pulling is performed based on the detection signal from the winding position detection unit 25 that detects the winding position of the belt reel 22. The lock mechanism 100 can be unlocked leaving a margin.

  Next, a second 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 configuration of the device shown in FIGS. 2 to 4 and the flowchart of FIG. . This example will also be described using the R-side motor 51 as an example.

  Similarly to FIG. 5, the flowchart shown in FIG. 6 also releases the locked state without applying unnecessary belt tension, that is, tension, to the occupant 11 when the locking mechanism 100 is activated and a locked state occurs in an emergency. The flow of control for performing is shown.

  In the first determination step S21, it is determined whether or not there is a change in the running state of the vehicle. If the determination in step 21 is NO, this control flow ends immediately, and if it is YES, step S22 and subsequent steps are executed.

  If YES in the determination step S21, the belt target position corresponding to the seat belt restraint state set in advance corresponding to the change in the running state of the vehicle is set to the reference value X0 or more (step S22). . When the target position is set in step S22, 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 S23, the control of the holding current for changing the belt winding amount by the R-side motor 51 is started.

  As an example of a basic operation of the seat belt device 10, 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 and pulls the belt portion 13 a into the retractor 16. . By maintaining the required energization amount of the R-side motor 51 as a holding current, the belt winding amount is set to a desirable target position.

  More specifically, the control of the holding current for setting the target position is performed until the “current value” determined by the holding current as the control object matches the “target position” in steps S24 to S27 as shown in FIG. Control continues.

  That is, when the current value does not coincide with the target position in the determination step S24, the process proceeds to the next determination step S25. In determination step S25, 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 S26), and when the current value is larger than the target position, the motor energization amount is decreased (step S27).

  Thereafter, in determination step S28, it is determined whether or not the traveling state of the vehicle is stable. If the running state is not stable, the process returns to step S24, and the above steps S25 to S27 are repeated. While the running state is not stable, control for matching the current value with the target position is performed.

  When the current value matches the target position in determination step S24, the process immediately proceeds to determination step S28. If it is determined at step S28 that the running state has not returned to the stable state (in the case of NO), the routine returns to step S24 and the above control procedure is repeated. If YES in determination step S28, that is, if the traveling state of the vehicle returns to the stable state, the process proceeds to the next determination step S29.

  In the determination step 29, it is determined 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 (NO), the control is ended. When the lock mechanism 100 is operated, the lock release control (step S30) is executed and then the control is ended.

  Even in the second control example described above, when the lock mechanism 100 attached to the retractor 16 is locked in an emergency, the belt 13 is wound up by the electric pretensioner using the R-side motor 51. When the lock state is to be released, the upper limit value of the belt winding amount is determined based on the reference value X0, so that the belt 13 can be wound while leaving a required belt margin. As a result, when unlocking using the electric pretensioner based on the belt winding position, unlocking can be performed without applying unnecessary belt tension to the occupant 11.

  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 used to release a lock state without applying unnecessary tension when a lock mechanism is operated in an emergency operation in a seat belt device of a vehicle.

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 functional block diagram which shows the function structure of the principal part of the control system of the seatbelt apparatus which concerns on this embodiment. It is a flowchart which shows the 1st example of the operation | movement procedure at the time of lock release of the seatbelt apparatus which concerns on this embodiment. It is a flowchart figure which shows the 2nd example of the operation | movement procedure at the time of lock release of the seatbelt apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Seat belt apparatus 11 Crew 13 Belt 16 Retractor 22 Belt reel 23 Motor 25 Winding position detection part 26 Control apparatus 61 Lock state determination part 62 Vehicle running state determination part 63 Seat belt apparatus control part 100 Lock mechanism 101 Mechanism main body part 102 Vehicle Sensor

Claims (3)

In a vehicle seat belt apparatus provided with a pretensioner mechanism comprising a belt reel that winds up a belt and a motor that drives the belt reel and pulls in the belt,
Winding position detection means for detecting the winding position of the belt reel;
Traveling state determining means for determining that the traveling state of the vehicle has changed to a predetermined state;
The energization amount to the motor is controlled based on the signal output from the running state determination means to control the drive amount of the motor, and the winding position is determined based on the detection signal from the winding position detection means. Control means for reducing the energization amount or stopping energization of the motor when the value of
A vehicle seat belt device comprising: A lock mechanism for preventing rotation of the belt reel in the belt drawing direction;
The control means includes unlocking means for driving the belt reel by a predetermined amount in the winding direction in order to unlock the locking mechanism.
The vehicle seat belt device according to claim 1.   3. The predetermined value is a value obtained by adding the predetermined amount in a belt pulling-out direction from a belt winding position in a state where the belt is fitted without giving a slack to an occupant. The vehicle seat belt apparatus according to claim.

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