JP2006044301A - Webbing takeup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a webbing takeup device free of indeliberate restriction of an air bag deployment even at having increased the restraining force of a webbing belt set on an occupant's body by the driving force of a motor. <P>SOLUTION: The webbing takeup device 10 determines whether or not a tension sensing signal is fed from a tension sensor 134 during the period from an obstacle sensing signal being emitted from the computation part 130 of an ahead monitoring device 132 till the motor 100 being started driving, i.e. whether or not a child seat set on the seat is secured by the webbing belt 34. Accordingly a tension increase of the webbing belt 34 due to the driving force of the motor 100 does not exert affection when determining whether or not the child seat set on the seat is secured by the webbing belt 34. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a webbing retractor constituting a seat belt device for restraining the body of an occupant seated on a seat of a vehicle or the like with a long belt-like webbing belt.

  A seat belt device that restrains the body of an occupant seated in a vehicle seat with a long belt-like webbing belt includes a webbing take-up device that is fixed to the vehicle body on the side of the seat. The webbing take-up device includes, for example, a spool whose axial direction is substantially in the vehicle front-rear direction, and the longitudinal base end side of the webbing belt is locked to the spool. The spool can wind the webbing belt around the outer periphery of the spool, and when the seat belt device is not used, the spool can be wound around the outer periphery of the spool and accommodated.

  The webbing take-up device is provided with a biasing member such as a spiral spring that biases the spool in the winding direction for winding the webbing belt. The webbing belt is wound up by the biasing force of the biasing member. When the webbing belt is mounted on the occupant's body, the slack of the webbing belt is removed by the urging force of the urging member.

  On the other hand, by winding a certain amount of webbing belt around the spool in a sudden deceleration state of the vehicle, etc., the slight slack called "slack" is eliminated and the restraining force of the occupant's body by the webbing belt is increased. Also, a mechanism for holding the occupant's body more reliably has been considered. This type of mechanism is generally configured to detect the sudden deceleration state of the vehicle with an acceleration sensor and forcibly rotate the spool in the winding direction with the driving force of a driving means such as a motor based on an electric signal from the acceleration sensor. (See Patent Document 1 for an example of such a so-called “motor retractor”).

On the other hand, the distance to other vehicles and obstacles in front is detected by a forward monitoring device such as a distance sensor, and when the distance to the preceding vehicle or obstacle is less than a certain value, the motor is operated, A configuration is also conceivable in which the spool is rotated in the winding direction with a rotational force of.
JP 2001-347923 A

  On the other hand, in addition to the above-described seat belt device, there is an airbag device as means for restricting the occupant's body from inertially moving toward the front side of the vehicle in the vehicle sudden deceleration state. The airbag device inflates and deploys the bag body on the front side of the seat in a vehicle suddenly decelerated state, and receives the body of an occupant who intends to move inertially toward the vehicle front side by the inflated and deployed bag body.

  By the way, in the airbag device corresponding to the passenger seat, when the child seat is fixed to the passenger seat, control is performed so that the bag body is not inflated and deployed even when the vehicle suddenly decelerates. Various methods have been devised for this control method. However, in the case where the child seat placed on the seat is fixed by the webbing belt, the webbing belt is used in comparison with the case where the occupant seated in the seat wears the webbing belt. Focusing on the fact that the tension acting in the longitudinal direction of the belt is sufficiently large, a configuration has been devised in which the tension acting on the webbing belt is detected by a tension sensor and the airbag device is controlled based on the detection result.

  Here, in the motor retractor as described above, the webbing belt is forcibly wound by rotating the spool in the winding direction by the driving force of the motor. For this reason, by forcibly winding the webbing belt in this way, the tension acting on the webbing belt may become equal to the tension when the child seat is fixed on the seat.

  In consideration of the above facts, the present invention provides a webbing take-up in which the deployment of the airbag is not inadvertently restricted even when the restraining force of the webbing belt attached to the occupant's body is increased by the driving force of the motor. The purpose is to obtain a device.

  In the webbing take-up device according to the first aspect of the present invention, the base end side in the longitudinal direction of the long belt-like webbing belt is locked, and the outer peripheral portion rotates by rotating in the one winding direction around its own axis. A spool for winding the webbing belt from the base end side, and a tension along the longitudinal direction of the webbing belt, and a child seat placed on a seat is restrained and fixed by the webbing belt. Tension detecting means for outputting a tension detection signal when the tension of the magnitude generated in the webbing belt acts on the webbing belt, and the output shaft is rotated by a driving force, and the rotation of the output shaft is transmitted to the spool to transmit the tension. The driving means for rotating the spool in the winding direction and the distance to the obstacle ahead of the traveling vehicle are detected, and the distance is less than a predetermined value. A front monitoring means for outputting an obstacle detection signal and an airbag control unit for controlling an airbag device provided in correspondence with the seat and capable of deploying a bag body in front of the seat in a vehicle sudden deceleration state And connected to both the tension detection means and the forward monitoring means, and the obstacle detection signal is input to drive the driving means, and the obstacle detection signal is input before the obstacle detection signal is input. Control means for outputting the child seat detection signal corresponding to the seat to the airbag control unit and disabling deployment of the airbag by inputting the tension detection signal until the drive means is driven. And.

  In the webbing take-up device according to the first aspect of the present invention, the webbing belt wound up and stored on the spool is pulled out and hung around the body of the vehicle occupant, for example, a tongue plate provided on the webbing belt Is held by a buckle device provided in the vicinity of the seat of the vehicle so that the webbing belt is attached to the occupant's body.

  Further, when the child seat is fixed on the seat, the webbing belt wound up and stored on the spool is pulled out with the child seat placed on the seat. Further, the buckle device holds the pulled-out webbing belt in the buckle device in a state where the webbing belt is engaged with a predetermined portion of the child seat. As a result, the child seat is fixed on the seat.

  Here, in this webbing take-up device, the tension detecting means detects the tension acting on the webbing belt in the longitudinal direction by the tension detecting means. Further, there is a difference in the tension acting on the webbing belt between the mounted state and the child seat fixed state. When the tension detecting means detects a tension of a magnitude that acts on the webbing belt in the child seat fixed state, the tension detecting means detects the tension from the tension detecting means. A detection signal is output.

  On the other hand, when the vehicle travels in such a mounted state or a child seat fixed state, a vehicle that is traveling or stopped in front of the traveling vehicle, or an obstacle other than the vehicle (hereinafter including the vehicle in front) The distance to the obstacle) is detected by the forward monitoring means. Next, when the distance to such an obstacle becomes less than a predetermined value, an obstacle detection signal is output from the front monitoring means.

  The obstacle detection signal output from the forward monitoring means is input to the control means. When the obstacle detection signal is input, the control unit operates the driving unit to rotate the spool in the winding direction. As a result, the webbing belt is wound around the spool. For example, if the webbing belt is attached to the body of the passenger seated in the seat in this state, the slack of the webbing belt called slack is removed. The occupant's body is held with a greater restraining force than before.

  Further, when the tension detection signal is output from the tension detection means between the input of the obstacle detection signal and the operation of the driving means, the tension detection signal is input to the control means.

  In this state, when a tension detection signal is input to the control means, a child seat detection signal is output from the control means. The child seat detection signal output from the control means is input to an airbag control unit that controls the airbag apparatus. The airbag device deploys the bag body to the front side of the seat in a vehicle rapid deceleration state.

  However, when the child seat detection signal is input to the airbag control unit, the airbag control unit disables the airbag device and does not deploy the airbag device even when the vehicle suddenly decelerates.

  Here, in the webbing take-up device according to the present invention, as described above, when the tension detection signal is input to the control unit from when the obstacle detection signal is input to the control unit until the drive unit is activated. Outputs a child seat detection signal.

  For this reason, even when the webbing belt is mounted, the driving unit operates to wind the webbing belt, and even if the tension acting on the webbing belt increases, a tension detection signal is output from the tension detection unit. In the control means, this tension detection signal is ignored. For this reason, in a state where the webbing belt is mounted on the occupant's body, the airbag device can be reliably operated.

  As described above, in the webbing take-up device according to the present invention, the detection by the tension detection means after the obstacle detection signal output from the front monitoring means is input to the control means until the drive means is activated. Based on the result, it is determined whether the webbing belt restrains the occupant's body or whether the child seat on the seat is fixed by the webbing belt. For this reason, it can prevent that deployment of an airbag is regulated carelessly.

<Configuration of the present embodiment>
FIG. 1 is a front sectional view showing an outline of the overall configuration of a webbing retractor 10 according to an embodiment of the present invention. FIG. 2 shows a seat belt device 12 to which the webbing retractor 10 is applied. The outline is shown by a side view.

  As shown in FIG. 1, the webbing take-up device 10 includes a frame 20. The frame 20 includes a flat plate 22. The back plate 22 is fixed to the vehicle body by fastening means (not shown) such as a bolt, for example, near the lower end of the center pillar 26 (see FIG. 2) of the vehicle 24. Thus, the webbing take-up device 10 is attached to the vehicle body.

  From both ends in the width direction of the back plate 22, a pair of leg plates 28 and 30 facing each other substantially in the vehicle longitudinal direction are extended in parallel to each other. A substantially cylindrical spool 32 is disposed between the leg plates 28 and 30.

  The spool 32 has an axial direction opposite to the leg plates 28 and 30 and is rotatable around its own axis. In addition, a longitudinal base end portion of a long belt-like webbing belt 34 is locked to the spool 32.

  The webbing belt 34 is wound and accommodated in a layered manner from the base end side on the outer peripheral portion of the spool 32 by rotating the spool 32 in the winding direction which is one of its axes. Further, when the webbing belt 34 is pulled from the front end side, the webbing belt 34 wound around the spool 32 is pulled out, and accordingly, the spool 32 rotates in a pulling direction opposite to the winding direction.

  As shown in FIG. 2, if the webbing take-up device 10 according to the present embodiment is applied to a driver seat or a passenger seat of the vehicle 24, the webbing belt 34 extends along the center pillar 26 of the vehicle 24. Is pulled out substantially upward of the vehicle. A shoulder anchor 36 that constitutes the seat belt device 12 together with the webbing retractor 10 is attached to the vehicle body near the upper end of the center pillar 26. The shoulder anchor 36 is formed with a slit hole 38 that allows the webbing belt 34 to pass therethrough, and the webbing belt 34 drawn out from the spool 32 passes through the slit hole 38 and is folded back substantially downward in the vehicle. .

  Further, as shown in FIG. 2, an anchor plate 40 is attached to the vehicle body in the vicinity of the webbing take-up device 10, and the tip of the webbing belt 34 is locked to the anchor plate 40.

  Further, the tongue plate 42 can be displaced by a predetermined range along the webbing belt 34 between the front end portion of the webbing belt 34 locked to the anchor plate 40 and the folded portion of the webbing belt 34 at the shoulder anchor 36. Is provided. Further, a buckle device 46 is provided on the opposite side of the webbing take-up device 10 and the anchor plate 40 via the seat 44 of the vehicle 24.

  The buckle device 46 is provided so that the front end side of the tongue plate 42 can enter. When the tongue plate 42 enters the inside of the buckle device 46 from the front end side, a latch (not shown) provided inside the buckle device 46 is provided. The tongue plate 42 is engaged to restrict the movement of the tongue plate 42 in the direction of coming out of the buckle device 46.

  On the other hand, as shown in FIG. 1, a torsion shaft 48 is provided coaxially with respect to the spool 32 inside the spool 32. Further, a fitting hole 50 is formed at the end of the spool 32 along the axial direction on the leg plate 28 side. The fitting hole 50 has a substantially circular shape with a cross section substantially coaxial with the spool 32, and the fitting hole 50 has a stepped shape in which the inner diameter dimension gradually increases toward one end in the axial direction.

  On the other hand, a lock mechanism 52 is provided at one axial end of the spool 32. The lock mechanism 52 includes a lock base 54. The lock base 54 includes a fitting portion 56.

  The fitting portion 56 is formed in a substantially columnar shape corresponding to the inner peripheral shape of the fitting hole 50, and the outer dimension is gradually reduced toward the other axial end of the spool 32 (leg plate 30 side). The fitting portion 56 is fitted in the fitting hole 50 so as to be coaxially rotatable relative to the spool 32 inside the fitting hole 50, and the end portion 48A of the torsion shaft 48 on the leg plate 28 side is coaxial and They are connected together.

  The lock mechanism 52 includes a case 58. The case 58 is provided outside the leg plate 28 (that is, opposite to the leg plate 30), and is fixed to the leg plate 28 integrally with the leg plate 28 by fastening means such as screws and fitting means such as fitting claws. ing. Inside the case 58, a member constituting the lock mechanism 52 such as a ratchet gear and a compression coil spring (not shown), and a spiral spring that urges the lock base 54 directly or indirectly in the winding direction are accommodated. Has been.

  The ratchet gear in the case 58 is pivotally supported by the lock base 54 so as to be coaxial with and relative to the spool 32 and the lock base 54. One end of the compression coil spring in the case 58 is locked to the ratchet gear, and the other end is locked to the lock base 54.

  When the urging force of the compression coil spring is increased by the lock base 54 rotating and compressing or pulling the compression coil spring, the compression coil spring urges the ratchet gear in the rotation direction of the lock base 54 by the urging force. The ratchet gear is configured to rotate following the lock base 54.

  Further, the ratchet gear is engaged with the lock plate 60 attached to the lock base 54, and the ratchet gear cannot follow the lock base 54 that is about to rotate in the pull-out direction (that is, the ratchet gear is locked). When the lock plate 60 rotates relative to the base 54 in the winding direction), the lock plate 60 is guided by the ratchet gear and moves outward in the rotational radial direction of the spool 32, and the internal teeth formed on the leg plate 28. The ratchet teeth 62 are engaged with each other. As a result, the rotation of the lock base 54 and consequently the spool 32 in the pull-out direction is restricted.

  Further, an acceleration sensor for the lock mechanism 52 (not shown) is disposed below the ratchet gear in the radial direction. The acceleration sensor includes an engaging claw that can move toward and away from the ratchet gear, a steel ball provided on the opposite side of the engaging claw to the ratchet gear, and a substantially dish-shaped mounting on which the steel ball is placed. And a mounting portion.

  The acceleration sensor for the lock mechanism 52 is configured such that when the steel ball rolls on the mounting portion in a state of rapid deceleration of the vehicle 24, the steel ball pushes up the engagement claw to move closer to the ratchet gear, and the engagement claw becomes the ratchet gear. Engage to regulate the rotation of the ratchet gear.

  As described above, the ratchet gear rotates following the lock base 54 by the urging force of the compression coil spring. However, when the rotation of the ratchet gear is restricted by the engagement claw of the acceleration sensor engaging the ratchet gear, the ratchet gear A relative rotation occurs between the gear and the lock base 54. Thereby, the lock plate 60 meshes with the ratchet teeth 62 as described above.

  On the other hand, a sleeve 82 is provided at an end 48B of the torsion shaft 48 on the leg plate 30 side. The sleeve 82 is formed in a bottomed cylindrical shape that opens toward the leg plate 28 side, and an end portion 48B of the torsion shaft 48 enters inside thereof, and the torsion shaft 48 and the sleeve 82 are coaxially and integrally connected. Has been.

  A circular hole 84 is formed in the spool 32 corresponding to the sleeve 82. The sleeve 82 is fitted into the circular hole 84 and is connected to the spool 32 coaxially and integrally.

  A shaft portion 86 extends coaxially with respect to the torsion shaft 48 and the spool 32 from the end surface of the sleeve 82 opposite to the torsion shaft 48. The shaft portion 86 passes through a circular hole 88 formed in the leg plate 30 and protrudes outside the leg plate 30.

  A clutch frame 90 is integrally attached to the leg plate 30 on the outside of the leg plate 30 by fastening means such as screws and fixing means such as fitting claws. A clutch 92 is accommodated inside the clutch frame 90. The clutch 92 includes a ring-shaped worm wheel 94. The worm wheel 94 is disposed coaxially with the shaft portion 86.

  Further, one or more pawls are provided inside the worm wheel 94. The pawl is mechanically connected to the worm wheel 94 at a position eccentric from the rotation center of the worm wheel 94, and rotates around the shaft portion 86 together with the worm wheel 94. Further, the pawl can be rotated with respect to the worm wheel 94 about an axis parallel to the shaft portion 86 at a connecting portion with the worm wheel 94.

  Further, an adapter (not shown) is provided on the axial center portion of the worm wheel 94. The adapter is coaxially and integrally connected to the shaft portion 86, and rotates integrally with the shaft portion 86 and eventually the spool 32.

  Further, ratchet teeth are formed on the outer peripheral portion of the adapter, and when the pawl rotates, the tip of the pawl engages with the ratchet teeth on the outer peripheral portion of the adapter. In this engaged state, the worm wheel 94 is mechanically coupled to the shaft portion 86 via the pawl and the adapter, and the rotation of the worm wheel 94 in the winding direction is transmitted to the shaft portion 86 via the pawl and the adapter, so that the shaft The part 86 is structured to rotate in the winding direction.

  On the other hand, as shown in FIG. 1, a motor 100 as a driving unit is provided below the spool 32. The motor 100 is on the opening direction side of the frame 20 in which the output shaft 102 has a substantially concave shape in plan view, that is, on the extending direction side of the leg plates 28 and 30 from the back plate 22, and the tip side thereof is the above clutch. It enters a gear case (not shown) different from the frame 90.

  A spur gear 104 is accommodated in the gear case. The gear 104 is coaxially and integrally attached to the output shaft 102. A spur gear 106 having a sufficiently larger number of teeth than the gear 104 is disposed on the side of the rotational radius direction of the gear 104 in the gear case.

  The gear 106 has a rotating shaft 108 in the same direction as the gear 104, and meshes with the gear 104. Further, a spur gear 110 having a sufficiently smaller number of teeth than the gear 106 is coaxially and integrally formed on the gear 106.

  Further, a spur gear 112 having a sufficiently larger number of teeth than the gear 110 is disposed on the side of the gear 110 in the radial direction of rotation in the gear case.

  The gear 112 has a rotating shaft 114 in the same direction as the gears 104 to 112 and meshes with the gear 110. The rotation shaft 114 of the gear 112 protrudes from the gear case and further enters the clutch frame 90. In the clutch frame 90, a worm gear 116 is provided coaxially and integrally with the rotating shaft 114 on the rotating shaft 114. The worm gear 116 meshes with the worm wheel 94, and the rotation of the output shaft 102 of the motor 100 is transmitted to the worm gear 116 via the gears 104 to 112, and when the worm gear 116 rotates, Then, the worm wheel 94 rotates.

  On the other hand, the motor 100 is electrically connected to the battery 124 via the driver 122, and the motor 100 is driven by being energized via the driver 122 to rotate the output shaft 102. Further, the driver 122 is electrically connected to an ECU 126 as a control unit, and when the drive control signal Ds output from the ECU 126 is input, power is supplied to the motor 100 to operate the motor 100.

  Moreover, ECU126 is electrically connected to the calculating part 130 which comprises the front monitoring apparatus 128 as a front monitoring means. The computing unit 130 is connected to the forward monitoring sensor 132 that constitutes the forward monitoring device 128 together with the computing unit 130. The front monitoring sensor 132 is provided in the vicinity of the front end of the vehicle 24, emits a monitoring signal such as infrared rays and radar toward the front side of the vehicle, and also travels in front of the vehicle and other obstacles (hereinafter referred to as front obstacles). The monitoring signal reflected by the vehicle including other vehicles traveling in front is referred to as an obstacle.

  The calculation unit 130 calculates the distance from the vehicle to the obstacle based on the time from when the monitoring signal is emitted from the front monitoring sensor 132 until it is reflected by the obstacle and received by the front monitoring sensor 132. . Further, the calculation unit 130 outputs the obstacle detection signal Ms when the calculation result is less than a predetermined size, that is, when the distance between the vehicle 24 and the obstacle ahead is less than a predetermined value. The obstacle detection signal Ms output from the calculation unit 130 is input to the ECU 126.

  The ECU 126 is electrically connected to a tension sensor 134 serving as a tension detection unit. The tension sensor 134 is provided on the anchor plate 40 described above. The tension sensor 134 detects a tension acting in the longitudinal direction on the webbing belt 34 in the vicinity of the anchor plate 40.

  Here, the child seat placed on the seat 44 acts on the webbing belt 34 when the child seat placed on the seat 44 is fixed, as compared with the case where the webbing belt 34 is wound around the body of the passenger seated on the seat 44. The tension is large enough.

  The tension sensor 134 outputs a tension detection signal Ts when a tension of a magnitude that acts on the webbing belt 34 when the child seat is fixed by the webbing belt 34 is detected. The tension detection signal Ts output from the tension sensor 134 is input to the ECU 126.

  Further, the ECU 126 is electrically connected to an ECU 138 serving as an airbag control unit that constitutes the airbag device 136. The ECU 138 is connected to the ignition device 140 that constitutes the airbag device 136 together with the ECU 138. If the operation stop signal is not output from the ECU 138 to the ignition device 140, the ignition device 140 operates when the vehicle suddenly decelerates. .

  When the ignition device 140 is activated, a gas generating agent provided in an inflator (not shown) is instantaneously burned and a large amount of gas is instantaneously generated. The gas generated in this way is supplied to the bag body constituting the airbag device 136, and the bag body is inflated and deployed in front of the seat 44.

<Operation and effect of the present embodiment>
Next, the operation and effect of the present embodiment will be described through the operation of the webbing take-up device 10.

  In the webbing take-up device 10, if the webbing belt 34 is pulled while pulling the tongue plate 42 while the webbing belt 34 is wound in layers on the spool 32, the webbing belt 34 wound on the spool 32 is pulled out. It is.

  The tongue plate 42 is inserted into the buckle device 46 while the webbing belt 34 pulled out in this way is hung around the front of the occupant seated on the seat 44, and the tongue plate 42 is held by the buckle device 46. The webbing belt 34 is attached to the body (hereinafter simply referred to as “attached state”).

  When the child seat is fixed on the seat 44, the webbing belt 34 wound around the spool 32 is pulled out with the child seat placed on the seat 44. Next, the pulled-out webbing belt 34 is engaged with a predetermined portion of the child seat, and the tongue plate 42 is held by the buckle device 46. Thereby, the child seat is fixed on the seat 44 by the webbing belt 34 (hereinafter, simply referred to as “child seat fixed state”).

  Here, in such a mounted state or a child seat fixed state, the webbing belt 34 is pulled out and hung around the occupant's body or child seat, so that a tension acts on the webbing belt 34 in the longitudinal direction. Such tension of the webbing belt 34 is detected by a tension sensor 134.

  Further, as described above, the tension acting on the webbing belt 34 is sufficiently larger in the child seat fixed state than in the mounted state. When the tension sensor 134 detects a tension of a magnitude that acts on the webbing belt 34 in the child fixed state, a tension detection signal Ts is output.

  Next, when the vehicle 24 travels in the mounted state or the child seat fixed state, the front monitoring device 128 operates and the ECU 126 reads and activates a control program as shown in FIG. Hereinafter, based on the flowchart of FIG. 3, an outline of control by the ECU 126 when the vehicle 24 travels will be described.

  When the vehicle 24 travels as described above and the front monitoring device 128 operates, the control program is started in step 200. Next, at step 202, it is determined whether or not an obstacle detection signal Ms is input to the ECU 126. If it is determined in step 202 that the obstacle detection signal Ms is not input to the ECU 126, the process returns to step 202 again.

  That is, the determination in step 202 is repeated until the obstacle detection signal Ms is input to the ECU 126, and the process waits until the obstacle detection signal Ms is input to the ECU 126.

  In this state, a monitoring signal is emitted from the front monitoring sensor 132 toward the front side of the vehicle. The emitted monitoring signal is reflected by an obstacle in front of the vehicle and received by the front monitoring sensor 132. The computing unit 130 computes the distance from the vehicle to the obstacle based on the time from when the monitoring signal is emitted from the front monitoring sensor 132 to when it is received.

  Further, the calculation unit 130 determines whether or not the calculation result is less than a predetermined value, that is, whether or not the distance from the vehicle 24 to the obstacle is less than the predetermined value.

  Next, when the calculation unit 130 determines that the distance to the obstacle is less than the predetermined value, the calculation unit 130 outputs an obstacle detection signal Ms. The obstacle detection signal Ms is input to the ECU 126.

  In this way, when the obstacle detection signal Ms is input to the ECU 126, the process proceeds from step 202 to step 204. In step 204, the signal Ts is read.

  Here, since the tension detection signal Ts is output from the tension sensor 134 in the child seat fixed state, the ECU 126 reads the tension detection signal Ts. Therefore, in the child seat fixed state, the process proceeds from step 206 to step 208, and the child seat detection signal Cs is output from the ECU 126. The child seat detection signal Cs output from the ECU 126 is input to the ECU 138.

  The ECU 138 outputs an operation stop signal when the child seat detection signal Cs is input. The operation stop signal output from the ECU 138 is input to the ignition device 140. When the operation stop signal is input to the ignition device 140, the ignition device 140 does not operate even if the vehicle suddenly decelerates.

  Therefore, in this state, the bag body is not inflated and deployed even when the vehicle is suddenly decelerated.

  Next, at step 210, the drive control signal Ds is output from the ECU 126, and the process ends at step 212. The drive control signal Ds output from the ECU 126 in step 210 is input to the driver 122. The driver 122 to which the drive control signal Ds is input energizes the motor 100 to drive the motor 100. When the motor 100 starts driving and the output shaft 102 rotates, the rotation of the output shaft 102 is transmitted to the worm gear 116 via the gears 104 to 112, and the worm gear 116 is rotated.

  Further, the rotation of the worm gear 116 is transmitted to the worm wheel 94 meshing with the worm gear 116 to rotate the worm wheel 94 of the clutch 92 in the winding direction. When the worm wheel 94 rotates in the winding direction, the pawl of the clutch 92 rotates and is connected to the adapter, and the clutch 92 is connected to the shaft portion 86 via the pawl and the adapter.

  Accordingly, when the shaft portion 86 rotates in the winding direction, the spool 32 connected to the shaft portion 86 via the sleeve 82, the torsion shaft 48, and the lock base 54 rotates in the winding direction. As the spool 32 rotates in the winding direction in this way, the webbing belt 34 is wound on the spool 32 from the base end side.

  When the webbing belt 34 is wound around the spool 32 in this way, the slack of the so-called “slack” of the webbing belt 34 is eliminated, and the webbing belt 34 is further wound around the spool 32 in this state. The child seat on the seat 44 is fixed with a strong restraining force.

  On the other hand, in the mounted state, the tension acting on the webbing belt 34 is sufficiently smaller than in the child seat fixed state. Therefore, the tension detection signal Ts is not output from the tension sensor 134 in the mounted state.

  For this reason, it is determined in step 206 that the tension detection signal Ts has not been input to the ECU 126 in step 206 described above, and the process proceeds to step 210 without going through step 208. Accordingly, the child seat detection signal Cs is not output from the ECU 126 in this state. For this reason, in this case, when the vehicle is suddenly decelerated, the ignition device 140 is activated, and the bag is inflated and deployed in front of the seat.

  As described above, the webbing retractor 10 reads the tension detection signal Ts after the obstacle detection signal Ms is output until the motor 100 starts to drive. For this reason, the ignition device 140 does not operate even if the motor 100 operates and a large tension is applied to the webbing belt 34 while the passenger is seated on the seat 44. Therefore, the occupant's body that moves inertially toward the front side of the vehicle in the vehicle sudden deceleration state can be held by the bag body inflated and deployed in front of the seat 44.

  In the present embodiment, the ECU 126 outputs the drive control signal Ds after the child seat detection signal Cs is output. However, if there is a time lag from when the drive control signal Ds is output until the motor 100 starts driving, the drive control signal Ds may be output before the tension detection signal Ts is read.

It is front sectional drawing which shows the structure of the webbing winding apparatus which concerns on one embodiment of this invention. It is a side view showing the outline of the composition of the seat belt device to which the webbing winding device concerning one embodiment of the present invention is applied. It is a flowchart which shows the outline of the flow of a process in a control means.

Explanation of symbols

10 Webbing take-up device 32 Spool 34 Webbing belt 100 Motor (drive means)
102 Output shaft 126 ECU (control means)
128 Forward monitoring device (forward monitoring means)
134 Tension sensor (tension detection means)
136 Airbag Device 138 ECU (Airbag Control Unit)

Claims (1)

A spool that winds up the webbing belt from the base end side to the outer peripheral portion by locking the longitudinal base end side of the long belt-shaped webbing belt and rotating it around one axis in one winding direction;
The tension along the longitudinal direction of the webbing belt is detected, and the child seat placed on the seat is restrained and fixed by the webbing belt so that the tension of the magnitude generated in the webbing belt is applied to the webbing belt. A tension detecting means for outputting a tension detection signal when acting,
Driving means for rotating the output shaft by a driving force, transmitting the rotation of the output shaft to the spool, and rotating the spool in the winding direction;
Forward monitoring means for detecting a distance to an obstacle ahead of the vehicle with respect to the running vehicle and outputting an obstacle detection signal when the distance is less than a predetermined value;
The tension detecting means and the front monitoring means are connected to an airbag control section that is provided corresponding to the seat and controls an airbag device that can deploy a bag body in front of the seat in a vehicle sudden deceleration state. The obstacle detection signal is inputted to drive the driving means, and the tension detection signal is inputted after the obstacle detection signal is inputted until the driving means is driven. A control means for outputting a child seat detection signal corresponding to the seat to the airbag control unit to disable deployment of the airbag by being input;
A webbing take-up device comprising:

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