JP2016155451A - Webbing winding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform smooth winding and storing of webbing using driving force of a motor.SOLUTION: When an engagement of a tongue and a buckle is released, a main try, in which a winding shaft is rotated in a winding direction by rotating an output shaft of a motor for a preset time period so as to wind webbing onto the winding shaft, is executed (step 236). Thereafter, a retry, in which the winding shaft is rotated in the winding direction by rotating the output shaft of the motor at a preset driving voltage and the motor is stopped when driving current reaches a preset current value, is repeated (steps 238-242). A time period from the rotation of the motor being started to the rotation being stopped is measured when executing the retry, and the retry is finished when the measured time period falls below a determination time, and storage assist by which the webbing is wound onto the winding shaft is finished (steps 244 and 246).SELECTED DRAWING: Figure 7

Description

  The present invention relates to a webbing take-up device.

  A vehicle such as a passenger car is provided with a seat belt device that restrains an occupant seated on the seat by webbing. The seat belt device is provided with a webbing take-up device for taking up and storing the webbing on a spool so that the webbing can be pulled out. The webbing take-up device takes up and stores the webbing drawn by the occupant when worn on a spool when not worn. In such a webbing take-up device, what is called a motor retractor that takes up and stores the webbing by rotating the spool in the webbing take-up direction by using the motor as the driving means and the driving force of the motor. is there.

  For a webbing take-up device that uses a motor, when the mounted state is released, the motor is energized to start winding the webbing onto the take-up shaft, the motor output shaft is locked, and the energizing current exceeds the threshold value. It has been proposed that when the energization to the motor is cut off by detecting the differential value of the increasing energization current and the webbing is fully stored when the differential value is greater than or equal to the reference value ( For example, see Patent Document 1.)

  In the proposal of Patent Document 1, when the webbing in the middle of winding involves a soft object such as an occupant's arm, the tangential slope of the energization current waveform is relatively gentle, but the webbing in the middle of winding is caught by a solid material. In this case, the slope of the tangent line of the current waveform becomes steep, so the differential value of the current that corresponds to the tangent line of the current waveform is used.When the differential value exceeds the reference value, all webbing is stored. Judging that it was.

  By the way, when the passenger gets off, the door is opened and closed. For example, a webbing before winding or a webbing in the middle of winding may be caught between doors that are opened and closed. If the webbing is wound while the webbing is sandwiched between the doors, even if the webbing remains unwound, the differential value of the energization current becomes equal to or greater than the reference value, and it is determined that the webbing is fully stored. there is a possibility.

  The webbing sandwiched between the doors can be wound on the take-up shaft by opening the door, but if it is determined that the webbing has been fully stored before it can be taken up, it is necessary to take up the webbing. In spite of this, there is a possibility of being left unrolled.

JP 2007-055308 A

  The present invention has been made in view of the above facts, and provides a webbing take-up device that enables proper webbing storage when winding and storing a webbing using a driving force of a motor. Objective.

  A webbing take-up device for achieving the above object is provided in which a base end of a webbing for restraining an occupant is locked and rotated in the take-up direction so that the webbing is taken up and stored in layers. A take-up shaft that rotates in the pull-out direction when the webbing is pulled out, an attachment / detachment detection unit that detects engagement and disengagement between a tongue provided on the webbing and a buckle fixed to the vehicle body, A motor having an output shaft that is rotated in a direction and rotating the output shaft in accordance with a supplied drive voltage, and transmitting the rotation of the output shaft of the motor to the winding shaft so that the winding shaft is wound on the winding shaft. A transmission means for rotating in the take-off direction, a current detection means for detecting the drive current of the motor, and when the engagement detection is detected by the attachment / detachment detection means, the drive voltage is supplied to control the output shaft of the motor. Rotated A confirmation operation for stopping the rotation of the output shaft and measuring the time from the start of rotation of the output shaft to the stop of rotation when the drive current detected by the current detection means reaches a predetermined limit value. And the determination corresponding to the time from the start of rotation to the stop when the output shaft is rotated in a state where the measurement time measured in the confirmation operation is wound on the winding shaft with the entire amount of the webbing wound Control means for controlling the confirmation operation to be repeated at a predetermined time interval until the time becomes equal to or less than a time, and when the measurement time becomes equal to or less than the determination time, control means for terminating the confirmation operation.

  According to the first aspect of the present invention, a confirmation operation for rotating the winding shaft in the winding direction of the webbing by operating a preset time interval motor is executed. At this time, if there is any webbing that can be wound, the webbing is wound around the winding shaft. In the confirmation operation, the webbing is taken up and the load on the take-up shaft increases, so that the drive current increases. The motor is stopped when the increased drive current reaches the limit value. The confirmation operation is repeated until the time from the start of rotation of the motor to the stop of rotation is measured and the measurement time becomes equal to or less than the determination time.

  The determination time corresponds to the time from the start of rotation to the stop of rotation when the motor is rotated in a state where the entire amount of webbing is wound around the winding shaft. The confirmation operation is terminated when the measurement time is equal to or less than the determination time, and thus the winding of the webbing around the winding shaft is terminated.

  Therefore, if there is unwinding of the webbing, the remaining webbing can be wound, and the winding of the webbing can be completed easily and appropriately.

  The webbing take-up device according to claim 2 corresponds to a time when the control means rotates the output shaft of the motor prior to the confirmation operation and the entire amount of the webbing is taken up by the take-up shaft. Performing a pre-operation for stopping the rotation of the output shaft after a lapse of time.

  According to the second aspect of the present invention, prior to the confirmation operation, the preliminary operation of rotating the motor is performed until the time corresponding to the time when the entire amount of the webbing is wound around the winding shaft has elapsed. Since the webbing pulled out from the winding shaft is wound around the winding shaft by this preliminary operation, the number of times the motor is operated in the confirmation operation can be reduced.

  In the webbing take-up device according to claim 3, in the preliminary operation, the control means rotates the output shaft at a rotation speed at which the take-up shaft becomes a pre-set take-up speed as the drive voltage. Supplying a voltage set in such a manner to the motor.

  According to the third aspect of the present invention, the drive voltage set so that the winding speed of the winding shaft in the pre-winding becomes a preset speed is supplied to the motor. At this time, by setting the winding speed of the winding shaft to a speed at which the webbing is gently moved and wound, the webbing can be smoothly moved and wound.

  In the webbing take-up device according to claim 4, the motor rotates the output shaft in a first direction or a second direction opposite to the first direction according to the supplied drive voltage, Transmission means transmits the rotation of the output shaft in the first direction to the take-up shaft to rotate the take-up shaft in the take-up direction, and the first of the output shaft. A range in which the rotation in the direction 2 is transmitted to the winding shaft to rotate the winding shaft in the winding direction, and the winding torque of the winding shaft does not reach a preset first torque. A second transmission means for transmitting the output torque of the output shaft to the take-up shaft, wherein the control means is configured to rotate the output shaft in the second direction in the preliminary operation. The drive voltage is supplied to a motor, and the output shaft is connected to the first shaft in the confirmation operation. Supplying the drive voltage to the motor to rotate in the direction of involves.

  According to the invention described in claim 4, the preliminary operation is performed by rotating the output shaft of the motor in the second direction and limiting the winding torque of the winding shaft to the first torque by the second transmission means. Rotate the winding shaft. Therefore, the winding shaft does not pull the webbing with a winding torque exceeding the first torque. Also, in the confirmation operation, by rotating the output shaft of the motor in the first direction, the winding shaft can be rotated in the winding direction via the first transmission means that does not limit the winding torque. The motor output shaft can be rotated until the current reaches the limit value.

  In the webbing take-up device according to claim 5, the control means obtains the limit value and the second torque in which the take-up torque of the take-up shaft is higher than the first torque in the confirmation operation. Including the current value of the drive current of the motor. Therefore, in the confirmation operation, the webbing can be pulled more strongly than the pre-operation, so that, for example, even when the webbing is sandwiched between the seat and the item on the seat, the webbing can be pulled out and wound up. .

  The webbing take-up device according to claim 6 is an open / close detecting means for detecting opening / closing of a door, a seating detecting means for detecting whether an occupant is seated on the seat, a vehicle speed detecting means for detecting a vehicle speed, and an operation of a shift lever. Including at least one detection means of a shift position detection means for detecting a position, and the control means starts supplying a drive voltage to the motor based on a detection result of the attachment / detachment detection means and the detection means. including.

  According to the invention described in claim 5, by including the detection result of at least one of the opening / closing detection means, the seating detection means, the vehicle speed detection means, and the shift position detection means, the webbing can be performed at an appropriate timing. Winding can be started.

  According to the present invention, it is possible to appropriately check whether or not the webbing winding has been completed, and to check whether the webbing winding has been completed or not and whether or not the winding has been completed. There is an effect that the webbing can be properly wound.

It is a schematic perspective view of the principal part of the vehicle which shows an example of the seatbelt apparatus which concerns on this Embodiment. It is a perspective view of the principal part which shows an example of a webbing winding device. It is a perspective view of the principal part which shows an example of a site | part different from FIG. 2 of a webbing winding device. It is a block diagram of the principal part which shows an example of the control part of the webbing winding device concerning this embodiment. It is a flowchart which shows an example of winding control of webbing. It is a flowchart which shows an example of fitting assistance control. It is a flowchart which shows an example of the storage assistance control which concerns on this Embodiment. It is a diagram which shows an example of the drive current of the motor with respect to time in the storage assistance which concerns on this Embodiment.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a seat belt device 10 according to the present embodiment. The seat belt device 10 is used in a vehicle 12 such as a passenger car. In the following description, the front of the vehicle 12 in the front-rear direction is indicated by an arrow FR, the upper side in the vertical direction is indicated by an arrow UP, and the inner side in the vehicle width direction is indicated by an arrow IN.

(Example of the configuration of the seat belt device)
The seat belt device 10 includes a webbing take-up device 16 that takes up and stores a long belt-like webbing 14 from a base end side that is one end side in the longitudinal direction. In the seat belt device 10, the webbing retractor 16 is disposed at, for example, the lower end portion of the center pillar 18 of the vehicle 12 and is fixed to a vehicle body (not shown). Further, the seat belt device 10 is a so-called three-point system, and the webbing 14 drawn out from the webbing take-up device 16 is wound around a slip joint 20 attached to the upper portion of the center pillar 18, for example. Wrapped. Further, in the seat belt device 10, the front end portion of the webbing 14 that is folded back by the slip joint 20 is locked to an anchor plate 22 that is fixed near the lower end portion of the center pillar 18.

  In the seat belt device 10, a tongue 24 that is slidable along the longitudinal direction of the webbing 14 is provided on the webbing 14 between the slip joint 20 and the anchor plate 22. The seat belt device 10 includes a buckle device 26. The buckle device 26 is disposed on a side opposite to the webbing retractor 16 of a seat (for example, a front seat) 28 on which an occupant riding the vehicle 12 is seated. The buckle device 26 includes an arm 32 having a buckle 30 attached to one end. For example, the other end of the arm 32 is fixed to the vehicle body so that the buckle 30 is in a predetermined position near the upper surface of the seat 28A of the seat 28. Has been. The seat belt device 10 is not limited to the buckle device 26, and the buckle 30 is provided between the attachment / detachment position of the seat 28 with the tongue 24 above the upper surface of the seat 28A and the storage position below the upper surface of the seat 28A. A buckle device provided with a lift-up mechanism to be moved may be used.

  In the seat belt device 10, the occupant seated in the seat 28 holds the tongue 24, pulls out the webbing 14 from the webbing take-up device 16, and engages the tongue 24 with the buckle 30. It becomes possible webbing wearing state. The seat belt device 10 is provided in each of the driver seat and the passenger seat, which are the front seats of the vehicle 12, and the rear seat is provided with seatable occupants. The seat belt device 10 provided in the seat will be described as an example. A known configuration is applied as the basic configuration of the seat belt device 10.

  2 and 3 show an example of the webbing take-up device 16 according to the present embodiment. As shown in FIG. 2, the webbing take-up device 16 includes a frame 34 that is fixed to a vehicle body (not shown). The frame 34 is formed in a U-shaped cross section, and includes leg plates 36 and 38 that face each other in the vehicle front-rear direction and are opposed to each other while being fixed to the vehicle body. A spool 40 serving as a winding shaft is disposed between the leg plates 36 and 38. In the present embodiment, the spool functions as an example of a winding shaft. The spool 40 is formed in a substantially cylindrical shape and is spanned between the leg plates 36 and 38 so as to be rotatable.

  In the spool 40, a base end portion that is one end side in the longitudinal direction of the long belt-like webbing 14 is engaged with the outer peripheral portion. The spool 40 is rotated in one direction about the axis (for example, the direction of arrow A in FIG. 2), whereby the webbing 14 is wound in layers, and the wound webbing 14 is at the end opposite to the base end side. By being pulled to the part side, it is rotated in the other direction (the direction opposite to one direction, the direction of arrow B in FIG. 2). In the following description, the arrow A direction is referred to as the winding direction of the webbing 14 and the arrow B direction is referred to as the drawing direction of the webbing 14 as an example.

  The spool 40 is provided with a rod-shaped torsion shaft (not shown) whose longitudinal direction is along the axial direction of the spool 40 at the shaft center portion. The torsion shaft is connected in a state in which the torsion shaft cannot rotate relative to the spool 40 in the vicinity of the end of the leg plate 38, and a known configuration that rotates integrally with the spool 40 is applied.

  A housing 44 of the lock mechanism 42 is attached to the leg plate 36 on the surface opposite to the leg plate 38. In the webbing take-up device 16, the lock mechanism 42 functions as an example of a lock unit that restricts the webbing 14 from being pulled out when the vehicle suddenly decelerates. The torsion shaft described above is directly or indirectly supported by the housing 44 so as to be rotatable. Inside the housing 44 is a so-called “VSIR mechanism” that operates when the vehicle suddenly decelerates and restricts rotation of the end of the torsion shaft on the leg plate 36 side in the pull-out direction. It constitutes a so-called “WSIR mechanism” that operates when the torsion shaft suddenly rotates in the pull-out direction, and restricts the end of the torsion shaft on the leg plate 36 side from rotating in the pull-out direction. A lock mechanism 42 is formed by accommodating various components.

  The leg plate 36 is provided with a pretensioner 46 on the side opposite to the leg plate 38. In the webbing take-up device 16, the pretensioner 46 functions as an example of a forced pulling means at the time of sudden vehicle deceleration. The pretensioner 46 operates in a vehicle suddenly decelerating state. By operating, the pretensioner 46 applies a rotational force in the winding direction to the end of the torsion shaft on the leg plate 36 side or the spool 40, thereby forcing the spool 40. Rotate in the winding direction. As a result, the seat belt device 10 prevents the occupant's body from moving forward of the vehicle by the webbing 14 during sudden deceleration of the vehicle.

  On the other hand, the webbing take-up device 16 is provided with a motor 48. In the present embodiment, the motor 48 functions as an example of a driving unit. The webbing take-up device 16 functions as a motor retractor that takes up the webbing 14 by rotating the spool 40 in the take-up direction by the driving force of the motor 48. In the webbing take-up device 16, the motor 48 is disposed below the spool 40 between the leg plates 36 and 38, for example. The motor 48 is arranged so that the axial direction of the output shaft 48A which is a rotation axis is along the axial direction of the spool 40, and the output shaft 48A is opposite to the leg plate 36 from a through hole 38A formed in the lower part of one leg plate 38. Is exposed. The motor 48 is rotationally driven in a second direction in which the output shaft 48A is opposite to the first direction and the first direction. In the following description, as an example, the first direction is the arrow C direction, the rotation in the direction of arrow C of the output shaft 48A of the motor 48 is referred to as normal rotation, the second direction is the arrow D direction, and the motor 48 The rotation of the output shaft 48A in the direction of arrow D is referred to as reverse rotation.

(Example of the configuration of the first transmission means)
A gear housing 50 as a housing member is attached to the leg plate 38 on the side opposite to the leg plate 36. In the gear housing 50, a lower recess 52 is formed in the lower portion as an accommodating portion that opens toward the side opposite to the leg plate 38. The lower recess 52 has a first recess 54 formed in the lower portion and a second recess 56 and a third recess 58 formed in the upper portion. Each of the first recess 54, the second recess 56, and the third recess 58 is formed in a cylindrical shape whose axial direction is along the axial direction of the output shaft 48A of the motor 48, and the lower recess 52 is the first recess 54, The second recess 56 and the third recess 58 are continuous so as to overlap each other. The first recess 54 has a larger diameter than the second recess 56 and the third recess 58, and the second recess 56 has a smaller diameter than the third recess 58.

  The gear housing 50 is formed with a cylindrical upper concave portion (not shown) that opens toward the leg plate 38 as an additional accommodating portion in the upper portion. The gear housing 50 is arranged such that the axis of the upper recess is coaxial with the axis of the spool 40. Further, the inner diameter of the upper recess is larger than the inner diameter of the first recess 54 of the lower recess 52, and the upper recess and the third recess 58 of the lower recess 52 are communicated with each other in the gear housing 50. (Not shown). Further, in the gear housing 50, the body portion of the motor 48 is fixed to the bottom wall of the lower recess 52, and the output shaft 48 </ b> A of the motor 48 is inserted into the bottom wall of the first recess 54 and protrudes into the first recess 54. ing.

  A driving force transmission mechanism 60 is accommodated in the gear housing 50. In the present embodiment, the driving force transmission mechanism 60 functions as an example of a transmission unit, and also functions as an example of a first transmission unit. An output gear 62 having flat teeth is attached to the output shaft 48A of the motor 48 protruding into the first recess 54. The second recess 56 of the lower recess 52 is provided with a two-stage shaft 64 coaxially with the second recess 56 and integrally with the bottom wall. The two-stage shaft 64 is provided with a two-stage gear 66, and the two-stage gear 66 is rotatably supported. In the two-stage gear 66, a large-diameter gear 68, each having external teeth and flat teeth, and a small-diameter gear 70 having a smaller diameter than the large-diameter gear 68 are formed coaxially and integrally and accommodated in the second recess 56. Has been. Further, the large-diameter gear 68 of the two-stage gear 66 has a larger diameter than the output gear 62 and meshes with the output gear 62. In the following description, the large diameter and small diameter of the gear indicate not only the outer diameter but also the number of teeth, and the large diameter gear has a larger number of teeth than the small diameter gear.

  The first recess 54 of the lower recess 52 is provided with an overload release mechanism 72 as a load limiting mechanism. In the first recess 54, a support shaft 74 is coaxially provided with the first recess 54 and is provided integrally with the bottom wall. On the support shaft 74, a ring holder 76 and a rotor 78 forming an overload release mechanism 72 are rotatably supported.

  The rotor 78 is a flat tooth with external teeth, and the ring holder 76 has a hollow shaft center (not shown), an outer diameter larger than that of the rotor 78, and a spur gear with external teeth. It is said that. The rotor 78 is coaxial with the ring holder 76, and one end side in the axial direction (the side opposite to the first recess 54 side of the gear housing 50) is inserted into the hollow interior of the ring holder 76.

  A predetermined number (for example, two) of ring members (not shown) formed of an elastic member are interposed between the inner peripheral surface of the hollow interior of the ring holder 76 and the rotor 78. The ring holder 76 is integrally rotatable via a ring member formed of an elastic member, and is rotatably supported by the support shaft 74 via the rotor 78. The ring holder 76 is rotatable relative to the rotor 78 against an elastic force (biasing force) received from the ring member by receiving a load (rotational torque) of a predetermined value or more in the rotation direction.

  The ring holder 76 has a larger diameter than the small diameter gear 70 of the two-stage gear 66, and meshes with the small diameter gear 70. The rotation of the output shaft 48 </ b> A of the motor 48 is transmitted to the ring holder 76 via the two-stage gear 66.

  Here, when the preloader 46 is operated, for example, the overload release mechanism 72 is operated when a rotational force with a load greater than a preset value is applied between the ring holder 76 and the rotor 78. The ring holder 76 and the rotor 78 are relatively rotated, and transmission of rotational force due to a load exceeding a preset value is prevented. As a result, the webbing take-up device 16 prevents the rotational force exceeding the preset load from being transmitted to the motor 48 and the like.

  In the third recess 58 of the lower recess 52, an external toothed spur intermediate gear 80 is coaxial with the third recess 58 and is rotatably arranged. The intermediate gear 80 has a larger diameter than the rotor 78 of the overload release mechanism 72 and meshes with the rotor 78.

  In the gear housing 50, a clutch mechanism 82 is disposed in an upper recess (not shown). In the present embodiment, the clutch mechanism 82 functions as an example of clutch means. The clutch mechanism 82 includes a clutch gear 84. The clutch gear 84 is hollow inside and is flat with external teeth. The clutch gear 84 has a diameter larger than that of the intermediate gear 80, and meshes with the intermediate gear 80 at a communication portion between the upper concave portion formed in the gear housing 50 and the third concave portion 58 of the lower concave portion 52. Accordingly, when the motor 48 is operated and the output shaft 48A is rotated in the forward direction (rotation in the direction of the arrow C), the clutch gear 84 causes the rotational force (driving force) of the output shaft 48A to become the output gear 62 and the second gear. The gear 66, the overload release mechanism 72 (ring holder 76 and rotor 78), and the intermediate gear 80 are decelerated and transmitted, and are rotated in the winding direction of the webbing 14.

  A predetermined number (for example, two) of lock levers (not shown) as clutch members are rotatably supported in the hollow inside of the clutch gear 84. In addition, a ratchet gear 86 is coaxially disposed at the axial center of the clutch gear 84. The ratchet gear 86 is connected to the spool 40 coaxially and in a relatively non-rotatable state via the end portion of the torsion shaft on the leg plate 38 side.

  The ratchet gear 86 has external ratchet teeth 86 </ b> A formed on the entire outer peripheral portion, and the ratchet teeth 86 </ b> A are disposed inside the hollow of the clutch gear 84. A substantially disc-shaped clutch cover 88 is disposed between the leg plate 38 and the clutch gear 84. The clutch cover 88 is attached so as to close the opening of the upper concave portion of the gear housing 50 with the ratchet gear 86 passing through the shaft center portion.

  In the clutch mechanism 82, when the clutch gear 84 is rotated in the winding direction by the forward rotation of the output shaft 48A of the motor 48, each of the lock bars (not shown) inside the clutch gear 84 rotates against the urging force. It is moved and meshes with the ratchet teeth 86A. Thus, in the clutch mechanism 82, when the clutch gear 84 is rotated in the winding direction, the clutch gear 84 and the ratchet gear 86 are integrally rotated, and the spool 40 is rotated in the winding direction.

  In the clutch mechanism 82, when the webbing 14 is pulled and the spool 40 is rotated in the pull-out direction, the ratchet gear 86 is rotated in the pull-out direction by the rotation of the spool 40 in the pull-out direction. In the clutch mechanism 82, the lock bar inside the clutch gear 84 is disengaged from the ratchet teeth 86A with respect to the rotation of the ratchet gear 86 in the pull-out direction, so that the clutch gear 84 and the ratchet gear 86 are relative to each other. Rotate. As a result, rotation of the spool 40 in the pull-out direction is prevented from being transmitted to the driving force transmission mechanism 60 and the like via the clutch gear 84.

  Further, in the clutch mechanism 82, the output shaft 48A of the motor 48 is rotated in the reverse direction, whereby the clutch gear 84 is rotated in the pulling direction, and the engagement state between the lock bar inside the clutch gear 84 and the ratchet teeth 86A is ensured. Is released. As a result, in the webbing take-up device 16 provided with the clutch mechanism 82, the pretensioner 46 and the like are operated to forcibly rotate the spool 40 in the take-up direction, and then rotate the output shaft 48A of the motor 48 in the reverse direction. Thus, the webbing 14 can be pulled out.

(Example of configuration of second transmission means)
On the other hand, a gear housing 90 is attached to the webbing take-up device 16 on the side opposite to the leg plate 38 of the gear housing 50. The ratchet gear 86 has a rotating shaft 86 </ b> B protruding from the through hole 50 </ b> A formed in the bottom wall of the upper recess of the gear housing 50 to the side opposite to the leg plate 38. Further, the ring holder 76 of the overload release mechanism 72 has a through hole 76A formed in the axial center portion, and is connected so as to rotate integrally with the rotor 78 by inserting a shaft or the like into the through hole 76A. Is done. In the following explanation, the axis of the ratchet gear 86 (the spool 40) as CL _1, showing the axis of the rotor 78 as CL _2. Further, for example, a sheet (not shown) may be interposed between the gear housing 50 and the gear housing 90.

  FIG. 3 shows an example of the driving force transmission mechanism 100 accommodated in the gear housing 90. In the present embodiment, the driving force transmission mechanism 100 functions as an example of a transmission unit and also functions as an example of a second transmission unit. 3 shows a state in which the gear housing 90 is viewed from the gear housing 50 side, and the right front side in FIG. 3 is the gear housing 50 and the leg plate 38 side (both are not shown in FIG. 3). In the description of FIG. 3, this direction is described as the gear housing 50 side or the leg plate 38 side.

In the gear housing 90, a fourth recess 102, a fifth recess 104, and a sixth recess 106 are formed on the surface on the gear housing 50 side. The fourth recess 102 is formed in a substantially cylindrical shape on the upper side of the gear housing 90, and the fifth recess 104 is formed in a substantially cylindrical shape on the lower side of the gear housing 90, with the upper side overlapping the fourth recess 102. It is continuous with the fourth recess 102. Further, the sixth recess 106 is formed in a substantially cylindrical shape partially overlapping the fifth recess 104 on the lower side of the gear housing 90, and is continuous with the fifth recess 104. Gear housing 90, the axis of the fourth recess 102 is a coaxial to the axis CL _1, the axis of the sixth recess 106 is attached to the gear housing 50 so as to be coaxial in the axial line CL _2.

  In the gear housing 90, a support shaft 108 is formed on the bottom wall of the fourth recess 102 coaxially with the fourth recess 102 and integrally with the bottom wall. A spool gear 110 is accommodated in the fourth recess 102. The spool gear 110 is formed in a bottomed cylindrical shape, and the opening side is directed to the bottom wall side of the fourth recess 102 and is rotatably supported by the support shaft 108.

  The spool gear 110 has external spur teeth. The spool gear 110 is provided with a winding spring 112 using a spiral spring or the like. The winding spring 112 functions as an example of an urging member. One end of the winding spring 112 is locked to the inner peripheral surface of the spool gear 110, and the other end is locked to an adapter (not shown) rotatably supported by the support shaft 108 of the fourth recess 102, for example. In contrast, the spool gear 110 is urged in the winding direction (the direction of arrow A in FIG. 3). For example, this adapter is prevented from rotating relative to the support shaft 108 by the urging force of the take-up spring 112, but is applied to the support shaft 108 by applying a rotational force stronger than the urging force of the take-up spring 112. On the other hand, relative rotation is possible in the winding direction and the drawing direction.

  The spool gear 110 is integrally formed with a rotating shaft 114 at the shaft center. The rotating shaft 114 protrudes from the spool gear 110 toward the gear housing 50. The spool gear 110 has a rotating shaft 114 coupled to a rotating shaft 86B (see FIG. 2) of the ratchet gear 86. Thereby, the spool gear 110 is rotated in the winding direction integrally with the ratchet gear 86 and the spool 40 by the urging force of the winding spring 112.

  Here, the urging force of the winding spring 112 is a weak urging force that does not cause the webbing 14 to be slack when the occupant wears the webbing 14. In other words, in the state where the occupant wears the webbing 14, the urging force is such that the webbing 14 does not sag and does not cause the occupant to feel tightness. Such a biasing force of the winding spring 112 is determined based on, for example, sensory evaluation of a person wearing the seat belt device 10.

  In the gear housing 90, a support shaft 116 is formed on the bottom wall of the sixth recess 106 coaxially with the sixth recess 106 and integrally with the bottom wall. The sixth recess 106 accommodates an idle gear 118 that is an external spur gear. The idle gear 118 is rotatably supported on the support shaft 116 of the sixth recess 106. The idle gear 118 is integrally provided with a rotating shaft 120 at the shaft center portion, and the rotating shaft 120 is inserted into the through hole 76A of the ring holder 76 and integrally rotates with the rotor 78 (see FIG. 3). Are linked together. Thus, the idle gear 118 is rotated in the direction of arrow F when the motor 48 operates and rotates in the forward direction (rotation in the direction of arrow C in FIG. 2), and the motor 48 operates and rotates in the reverse direction (indicated by the arrow in FIG. 2). Rotate in the direction of arrow D).

  On the other hand, the driving force transmission mechanism 100 includes a clutch mechanism 122. The gear housing 90 houses the clutch mechanism 122 in the fifth recess 104. The clutch mechanism 122 functions as an example of clutch means. The clutch mechanism 122 includes a base portion 124, a rotor 126, a clutch gear 128, and a clutch spring 130, and functions as a centrifugal sliding clutch.

  In the gear housing 90, a support shaft 132 is provided on the bottom wall of the fifth recess 104. The support shaft 132 protrudes integrally from the axial center part of the 5th recessed part 104 toward the gear housing 50 (refer FIG. 2).

  The base portion 124 is provided with a disk-shaped base plate 134. The base plate 134 is rotatably supported by a support shaft 132 formed in the fifth recess 104 of the gear housing 90. The base plate 134 is formed with a support shaft 136 at the axial center, and a substantially C-shaped side wall 138 is formed coaxially with the support shaft 136. The base plate 134 has a support shaft 136 and a side wall 138 projecting in the direction opposite to the gear housing 90. Further, the base plate 134 is formed with a pair of rectangular extending portions 140 that protrude outward from the peripheral edge in the radial direction. The extended portion 140 is formed such that a tip portion is formed in an arc shape coaxially with the base plate 134, and a protruding portion 140 </ b> A protrudes from the tip portion toward the gear housing 90.

  The rotor 126 is formed in a bottomed cylindrical shape, the opening side is directed to the base plate 134, and is arranged coaxially with the base plate 134. The rotor 126 is rotatable integrally with the base plate 134 by fitting a side wall 138 of the base plate 134 into an opening directed to the base plate 134. The rotor 126 is arranged such that one end side in the axial direction is a gear 142 formed with spur teeth with external teeth, the other end side is a non-gear part 144, and the non-gear part 144 is on the base plate 134 side. The rotor 126 is rotated by the rotational force of the motor 48 when the gear 142 is engaged with the idle gear 118 and the motor 48 (see FIG. 2) is operated.

  The clutch gear 128 is formed in a cylindrical shape, and external spur teeth are formed on the outer peripheral portion. The clutch gear 128 has an inner diameter that is larger than the outer diameter of the non-gear portion 144 of the rotor 126, and an inner peripheral surface that faces the non-gear portion 144, and is disposed coaxially with the rotor 126 and relatively rotatable. Has been.

  Clutch gear 128 is meshed with spool gear 110. The clutch gear 128 has an inner diameter larger than the outer diameter of the non-gear portion 144 of the rotor 126, so that a gap is formed between the clutch gear 128 and the rotor 126. For example, a torsion coil spring or the like is formed in the gap. A clutch spring 130 using is used. The clutch spring 130 has an outer diameter smaller than the inner diameter of the clutch gear 128 in the non-stretchable natural state, and can rotate relative to the clutch gear 128 in the normal state.

  The base portion 124 is provided with a lever 146 and a return spring 148 between the base plate 134 and the rotor 126. The lever 146 is formed of a pair of a cylindrical bearing portion 150 and connecting portions 152 and 154 that protrude radially outward from the outer peripheral portion of the bearing portion 150. Each of the connecting portions 152 and 154 is formed with a connecting projection 156 that protrudes in the same direction. The lever 146 is configured such that the support shaft 136 of the base plate 134 is inserted into the bearing portion 150 in a state where the connection protrusions 156 of the connection portions 152 and 154 are directed toward the base plate 134, so that the lever 146 can rotate relative to the base plate 134. Supported.

  A pair of long holes 158 are formed in the base plate 134 corresponding to the connection protrusions 156 of the connection portions 152 and 154 of the lever 146. The pair of long holes 158 are provided in pairs with the support shaft 136 therebetween, and each long shaft has an arc shape centered on the support shaft 136 and is formed as a through hole in the base plate 134. In the lever 146, each of the connecting protrusions 156 of the connecting portions 152 and 154 is inserted into the elongated hole 158 of the base plate 134, and the range in which the lever 146 can be rotated relative to the base plate 134 is limited.

  For example, a coil spring or the like is used as the return spring 148, and one end is locked to the connecting portion 152 of the lever 146. The return spring 148 is engaged with a side wall 138 formed on the base plate 134 at the other end. Accordingly, the return spring 148 urges the lever 146 in the arrow H direction with respect to the base plate 134. As a result, the lever 146 is held by the base plate 134 so that the connecting projection 156 is positioned at one end of the long hole 158 by the urging force of the return spring 148.

  Further, the lever 146 has an engaging recess 154 </ b> A in the connecting portion 154. The above-described clutch spring 130 is bent with both ends directed inward in the radial direction, one end locked to an engaging recess 154A formed in the connecting portion 154 of the lever 146, and the other end rotor. 126 is engaged with an engagement recess (not shown) formed in the non-gear portion 144 of 126.

  Thus, the clutch spring 130 is expanded in diameter by the lever 146 rotating in the arrow G direction with respect to the base plate 134 against the urging force of the return spring 148. The clutch spring 130 is brought into pressure contact with the inner peripheral surface of the clutch gear 128 by expanding the diameter, and is coupled and rotated integrally with the inner peripheral surface of the clutch gear 128 by a frictional force.

  The rotor 126 can be rotated integrally with the clutch gear 128 by the clutch spring 130 being integrally connected to the clutch gear 128 by the frictional force. The rotor 126 and the clutch gear 128 are rotated relative to each other when a rotational force exceeding the frictional force between the clutch spring 130 and the clutch gear 128 is applied. Further, the rotor 126 can be rotated relative to the clutch gear 128 by reducing the diameter of the clutch spring 130.

  On the other hand, in the clutch mechanism 122, a circular spacer 160 is disposed between the gear housing 90 and the base plate 134, and a pair of weights 162 is disposed between the spacer 160 and the base plate 134. The spacer 160 has a cylindrical shaft portion 160A formed at the shaft center portion, and a support shaft 132 is inserted through the shaft portion 160A. The spacer 160 has a pair of bottomed relief grooves 160B corresponding to each of the pair of long holes 158 formed in the base plate 134 around the shaft portion 160A. Each of the escape grooves 160 </ b> B is formed in an arc shape having the same diameter as the long hole 158 of the base plate 134, and the distal end portion of the connection protrusion 156 of the lever 146 protruding from the long hole 158 of the base plate 134 enters. The lever 146 and the spacer 160 are prevented from buffering each other when the distal end portion of the connecting projection 156 enters the escape groove 160B.

  Each of the weights 162 is formed in a strip shape having a wide outer shape and a substantially arc shape in the longitudinal direction and having an equivalent weight, and is disposed so as to surround the shaft portion 160A of the spacer 160. Each weight 162 is formed with a bearing hole 164 on one end side in the longitudinal direction. A support shaft (not shown) is formed on the base plate 134 at a predetermined position in the vicinity of a pair of outer peripheral portions sandwiching the shaft center portion on the surface of the gear housing 90. Each of the weights 162 is supported by the base plate 134 so as to be rotatable about the bearing hole 164 by inserting the support shaft of the base plate 134 into the bearing hole 164B.

  Each of the weights 162 has an engaging claw 166 formed in a substantially U shape on the other end side in the longitudinal direction. Each of the weights 162 is engaged with each of the engaging claws 166 in a state where the connection protrusion 156 of the lever 146 protruding from the long hole 158 of the base plate 134 is inserted into the substantially U-shaped inside.

  Here, in the clutch mechanism 122, when the rotor 126 is rotated in the arrow G direction, the base plate 134 is rotated in the arrow G direction. Each of the weights 162 is supported on the base plate 134 via a support shaft (not shown), and each of the weights 162 follows the rotation of the base plate 134 and rotates. At this time, each of the weights 162 is supported by the bearing hole 164B on one end side in the longitudinal direction, so that the engaging claw 166 side is rotated so that the diameter of the engaging claw 166 is expanded outward in the radial direction of the base plate 134 by centrifugal force. Move. At this time, the diameter of each of the weights 162 is brought into contact with the protrusion 140 </ b> A formed on the extending portion 140 of the base plate 134 and the diameter expansion is limited.

  Each of the weights 162 is engaged with the engaging claw 166 and the connecting projection 156 of the lever 146. By rotating so that the diameter of the weight 162 increases, the lever 146 follows the diameter of the weight 162. Thus, the base plate 134 is rotated in the direction of arrow G. One end of the clutch spring 130 is locked to the lever 146, and the end of the clutch spring 130 that is locked to the connecting portion 154 of the lever 146 as the lever 146 rotates in the arrow G direction. The diameter is increased by turning in the direction of arrow G. As a result, in the clutch mechanism 122, the clutch spring 130 contacts the inner peripheral surface of the clutch gear 128, and the clutch gear 128 rotates in the direction of arrow G integrally with the base plate 134.

  The spool gear 110 is engaged with the clutch gear 128, and when the clutch gear 128 rotates in the direction of the arrow G, the spool gear 110 is compensated for insufficient urging force of the winding spring 112, and the winding of the webbing 14 is compensated. It rotates in the direction of arrow A, which is the taking direction. That is, in the driving force transmission mechanism 100, when the output shaft 48A of the motor 48 is rotated in the reverse direction (in the direction of arrow D in FIG. 2), this rotational force is transmitted to the spool gear 110 and the spool gear 110 is rotated in the winding direction. . As a result, the spool 40 rotates in the winding direction to wind up the webbing 14 (see FIG. 2).

  Here, when the clutch spring 130 is in contact with the inner peripheral surface of the clutch gear 128 and the winding torque of the spool 40 reaches a preset torque, the clutch spring 130 rotates relative to the clutch gear 128 against the frictional force. To do. Therefore, the clutch mechanism 122 limits the winding torque of the spool 40 by the frictional force generated between the clutch gear 128 and the clutch spring 130.

  In addition, when the motor 48 stops and the rotation of the rotor 126 stops, the clutch mechanism 122 stops the rotation of the base plate 134. As a result, the lever 146 is rotated in the direction of the arrow H by the urging force of the return spring 148, and each of the weights 162 is rotated and reduced in diameter as the lever 146 rotates.

  In the clutch spring 130, the lever 146 is rotated in the direction of arrow H by the urging force of the return spring 148, so that one end side of the lever 146 engaged with the connecting portion 154 is rotated in the direction of arrow H to reduce the diameter. . The clutch spring 130 is separated from the inner peripheral surface of the clutch gear 128 by reducing the diameter. As a result, the clutch mechanism 122 releases the engagement state between the rotor 126 and the clutch gear 128, and the clutch gear 128 can rotate relative to the base plate 134. In the clutch mechanism 122, when the rotor 126 is rotated in the arrow H direction, the lever 146 is held in a state of being biased in the arrow H direction by the return spring 148, whereby the clutch gear 128 is moved to the base plate 134. Is maintained in a state in which it can rotate relative to each other.

(Example of control unit configuration)
FIG. 4 shows a schematic configuration of the control unit 170 provided in the webbing take-up device 16. The controller 170 controls the operation of the motor 48. The control unit 170 includes an ECU (Electronic Control Unit) 172 including various functional circuits such as a microcomputer, an A / D conversion circuit, a D / A conversion circuit, and a power circuit (drive circuit). In the present embodiment, ECU 172 functions as an example of a control unit. The seat belt device 10 is provided in each of the driver seat, the passenger seat, and the rear seat of the vehicle 12, and the rear seat is provided with a seatable occupant, but the ECU 172 includes a plurality of seats. Each belt device 10 may be provided, or one ECU 172 may control the winding of the webbing 14 of the plurality of seat belt devices 10.

  The ECU 172 is connected with a motor 48 to be controlled. The ECU 172 is supplied with electric power from a battery (not shown) provided in the vehicle 12, operates with electric power supplied from the battery, and operates the motor 48 with electric power supplied from the battery. The ECU 172 controls the rotation speed and rotation direction (forward rotation or reverse rotation) of the output shaft 48A of the motor 48 by controlling the drive voltage for operating the motor 48 and the polarity of the drive voltage. In the webbing take-up device 16, the rotation speed of the motor 48 is controlled to control the rotation speed of the spool 40, that is, the winding speed of the webbing 14 onto the spool 40. Further, the ECU 172 controls the output torque by limiting the current when the motor 48 is operated. In the webbing take-up device 16, the take-up torque of the spool 40 is obtained according to the output torque of the motor 48. Further, in the webbing take-up device 16, a tension corresponding to the take-up torque of the spool 40 is generated in the webbing 14, and the take-up torque is restricted, so that the load applied to the shoulder portion of the occupant wearing the webbing 14 is restricted. The

  As shown in FIG. 1, the seat belt device 10 is provided with a buckle switch 174 in the buckle device 26. Further, the vehicle 12 is provided with, for example, a door switch 178 for detecting opening / closing of the door 176, a seat switch 180 for detecting whether an occupant is seated on the seat 28A of the seat 28, and the like. In the present embodiment, the buckle switch 174 functions as an example of an attachment / detachment detection unit, the door switch 178 functions as an example of an opening / closing detection unit, and the seat switch 180 functions as an example of a seating detection unit.

  When the occupant seated on the seat 28 </ b> A of the seat 28 wears the webbing 14, the seatbelt device 10 pulls out the webbing 14 from the webbing retractor 16 and engages the tongue 24 with the buckle 30. In the seat belt device 10, the engagement between the tongue 24 and the buckle 30 is released by operating a release button (not shown) provided on the buckle 30. The buckle switch 174 outputs a signal corresponding to the engagement state between the tongue 24 and the buckle 30. For example, the buckle switch 174 outputs an on signal by engaging the tongue 24 with the buckle 30 and outputs an off signal when the engagement is released.

  The door switch 178 outputs a signal corresponding to the open / closed state of the door 176 by the occupant. For example, the door switch 178 outputs an off signal when the door 176 is closed, and outputs an on signal when the door 176 is opened. The seat switch 180 outputs a signal corresponding to the seating of the occupant on the seat 28A of the seat 28. For example, the seat switch 180 outputs an ON signal when an occupant sits on the seat 28 and is pressed with a pressure equal to or higher than a predetermined pressure, and outputs an OFF signal when the occupant leaves the seat and the pressing force becomes less than a predetermined value. .

  As shown in FIG. 4, a buckle switch 174, a door switch 178, and a seat switch 180 are connected to the ECU 172. The ECU 172 is connected to a vehicle speed sensor 182 that outputs a signal corresponding to the traveling speed of the vehicle 12 and a shift position sensor 184 that outputs a signal corresponding to an operation state (shift position) of a shift lever (not shown) of the vehicle 12. Has been. In the present embodiment, the vehicle speed sensor 182 functions as an example of a vehicle speed detection unit, and the shift position sensor 184 functions as an example of a shift position detection unit.

  The ECU 172 controls the operation of the motor 48 and controls the winding of the webbing 14 based on signals input from various detection means such as a buckle switch 174, a door switch 178, a seat switch 180, a vehicle speed sensor 182, and a shift position sensor 184. Take. In the present embodiment, various detection means such as a buckle switch 174, a door switch 178, a seat switch 180, a vehicle speed sensor 182, and a shift position sensor 184 are provided as an example. It is not limited to. As the detection means, at least the buckle switch 174 may be provided. In addition to the buckle switch 174, the detection unit may include at least one of a door switch 178, a seat switch 180, a vehicle speed sensor 182 and a shift position sensor 184. Further, when the buckle device 26 includes a lift-up mechanism, it is preferable to further include a detection unit that detects that the buckle device 26 has been moved to the storage position.

  The controller 170 is provided with a current sensor 186 that detects a current for driving the motor 48. In the present embodiment, the current sensor 186 functions as an example of a current detection unit. The ECU 172 is connected to a current sensor 186, reads the driving current of the motor 48 detected by the current sensor 186, and controls output power (for example, output voltage) so as not to exceed a preset current value. The output torque of the motor 48 is controlled. In the webbing take-up device 16, the take-up torque of the spool 40 is restricted by restricting the output torque of the motor 48. In the present embodiment, the current sensor 186 is provided separately from the ECU 172 as an example. However, the present invention is not limited thereto, and the ECU 172 may include the function of the current sensor 186.

  Here, the ECU 172 confirms whether or not the occupant is wearing the webbing 14 with the buckle switch 174. Further, the ECU 172 uses the door switch 178 and the seat switch 180 to check whether the occupant is seated in the seat and whether the occupant is expected to move the body. Further, the ECU 172 uses the vehicle speed sensor 182 and the shift position sensor 184 to check whether the vehicle 12 has started forward travel or has reached a state in which forward travel has started. For example, when the ECU 172 confirms that the possibility that the occupant is seated on the seat and moves the body is low, the ECU 172 confirms whether or not the webbing 14 can be in close contact with the occupant by the buckle switch 174. Further, the ECU 172 closes the webbing 14 closely to the occupant when, for example, the vehicle 12 reaches a state in which the vehicle 12 can start the forward travel or the vehicle 12 starts the forward travel with the tongue 24 engaged with the buckle 30. The webbing 14 is wound up. In the following description, the winding for bringing the webbing 14 into close contact with the occupant by the motor 48 is referred to as fitting assist.

  Further, when the ECU 172 confirms by the buckle switch 174 that the vehicle 12 is stopped and the occupant is disengaged from the tongue 24 and the buckle 30 for getting off, the webbing 14 is wound around the spool 40 and stored. . The ECU 172 operates the motor 48 to rotate the spool 40 in the winding direction, and winds the webbing 14 drawn from the spool 40 onto the spool 40. In the following description, the winding of the webbing 14 to the spool 40 for storing the webbing 14 by the motor 48 is referred to as a storage assist.

  As described above, the webbing take-up device 16 includes the driving force transmission mechanism 60 that transmits the rotational force of the motor 48 to the spool 40 and rotates the spool 40 in the take-up direction when the motor 48 rotates forward. . Further, the webbing take-up device 16 is provided with a driving force transmission mechanism 100 that transmits the rotational force of the motor 48 to the spool 40 and rotates the spool 40 in the take-up direction when the motor 48 rotates in the reverse direction. In the webbing take-up device 16, the driving force transmission mechanism 60 is used when fitting assist is executed. The webbing take-up device 16 uses the driving force transmission mechanism 100 in which the take-up torque of the spool 40 is limited as an example when the storage assist is executed, and thereafter, the take-up torque of the spool 40 is controlled. A possible driving force transmission mechanism 60 is used.

  When executing the fitting assist, the ECU 172 of the webbing take-up device 16 rotates the spool 40 in the take-up direction via the driving force transmission mechanism 60 by driving the motor 48 in the normal direction. At this time, the ECU 172 limits the output torque of the motor 48 by limiting the drive current of the motor 48 and limits the winding torque of the spool 40.

  In the seat belt device 10 according to the present embodiment, a load that the occupant receives from the webbing 14 when the webbing 14 is brought into close contact with the occupant is set, and the winding torque of the spool 40 is limited based on the set load. . That is, in order to obtain a high occupant restraint by the webbing 14, the spool 40 needs a large winding torque in order to pull the webbing 14 strongly so as not to generate so-called slack. However, if the winding torque of the spool 40 is too large, the occupant will receive a large load, causing discomfort to the occupant.

From here, in the seatbelt apparatus 10, for example, when performing fitting assist for bringing the webbing 14 into close contact with the occupant, the load (for example, the upper limit of the load) applied to the occupant by the webbing 14 based on the occupant restraint and sensory evaluation Is set. In the webbing take-up device 16, the upper limit of the take-up torque of the spool 40 is determined based on the set load, and the output torque of the motor 48 is set based on the set upper limit of the take-up torque. The ECU 172 of the webbing take-up device 16 has a limit value (a limit value) of the drive current I with respect to the drive voltage V of the motor 48 when performing the fitting assist based on the output torque of the motor 48 according to the take-up torque of the spool 40. Current I _F ) is set.

The ECU 172 sets the drive voltage V to a preset voltage V _F (for example, V _F = 12v), supplies the drive voltage V so that the motor 48 rotates in the forward direction, and starts fitting assist. Further, ECU 172 detects, for example, the driving current I of the motor 48 by the current sensor 186, the detected drive current I reaches the limit current _{I F} and (I ≧ _{I F),} to stop the operation of the motor 48 fitting End assist. Incidentally, ECU 172 is rotated forward rotation of the motor 48 at a predetermined drive voltage _V (V = V _F) shall be operated for a predetermined time, the driving current I during operation of the motor 48 is smaller than the limit current _{I F} (I ≦ The drive voltage V may be controlled to be I _F ).

  Further, when a large biasing force is applied so that the webbing 14 worn by the occupant does not sag in a state where the fitting assist has been completed, there is a possibility that the occupant may experience discomfort such as a feeling of pressure. From this point, in the seat belt device 10, the tension of the webbing 14 is set based on the sensory evaluation so that a non-compressed feeling can be obtained for the mounted occupant (not causing discomfort such as a feeling of pressure). The urging force of the take-up spring 112 of the webbing take-up device 16 is determined so that the urging force is obtained.

  Accordingly, the webbing take-up device 16 is limited in the take-up torque of the spool 40, and does not give a load that causes discomfort to the occupant wearing the webbing 14, thereby obtaining high occupant restraint. Further, the webbing take-up device 16 can maintain the restrained state of the occupant in a state in which the occupant feels uncompressed after the fitting assist is completed.

  On the other hand, when executing the storage assist, the ECU 172 first executes a main trie that operates the motor 48 for a predetermined time and winds the webbing 14 around the spool 40. Further, when the ECU 172 finishes the main trie, the motor 48 is operated at a preset time interval, and the winding of the webbing 14 remaining on the spool 40 and the winding of the webbing 14 to the spool 40 are completed. Execute retry to repeat the operation to confirm whether or not. In the present embodiment, as an example, the storage assist includes a main try, a retry, and an end determination. In the present embodiment, the main trie functions as an example of a preliminary operation, and the r-value trie functions as an example of a confirmation operation.

When executing the main trie, the ECU 172 sets the drive voltage V to a preset voltage V _T and reverses the motor 48 for a preset time Tm at the set drive voltage V (voltage V _T ). Rotate. As a result, the rotation of the motor 48 is transmitted through the driving force transmission mechanism 100, and the spool 40 is rotated in the winding direction with the winding torque being limited by the clutch mechanism 122. The rotational speed of the spool 40, that is, the moving speed of the webbing 14 during the main trie is determined by the drive voltage V (voltage V _T ) of the motor 48.

  When executing the retry, the ECU 172 sets the drive voltage V to a preset voltage Vr and rotates the motor 48 in the normal direction, thereby rotating the spool 40 in the winding direction via the drive force transmission mechanism 60. Let In addition, the ECU 172 ends one retry when the drive current I reaches a preset limit value Ir. Thus, the winding torque of the spool 40 at the time of retry, that is, the tension generated in the webbing 14 is limited by the limit value Ir of the drive current I. In the present embodiment, the limit value Ir functions as an example of a drive current limit value in the confirmation operation.

  Further, every time a retry is executed, the ECU 172 measures the time from the start of the operation of the motor 48 until the drive current I reaches the limit value Ir, and the measured time T and a preset determination time Ts are measured. Based on this, it is determined whether or not the winding of the webbing 14 has been completed. If it is not determined that the winding of the webbing 14 has been completed based on the measurement time T and the determination time Ts, the ECU 172 repeats the retry and determines that the winding has been completed, thereby ending the storage assist.

  Here, it is not preferable that the webbing 14 that has been released is wound around the spool 40 (the winding speed of the webbing 14) is not too fast or too slow. Affects time. In addition, when winding the webbing 14 that has been released, if the tension applied to the webbing 14 is large, the webbing 14 or the tongue 24 is pulled with an unnecessarily large tension. It is preferable that the tension is sufficiently lower than the tension for contacting the passenger.

  From here, in the seatbelt apparatus 10, the winding speed, winding time, and tension | tensile_strength of the webbing 14 which can store the webbing 14 smoothly and smoothly at the time of a main try are preset by a test. At this time, the tension is set to a sufficiently low tension as compared with the tension for bringing the webbing 14 into close contact with the occupant.

The ECU 172 is set with the operating time Tm of the motor 48 during the main trie based on the winding time set by the seat belt device 10 and the voltage of the drive voltage V of the motor 48 based on the winding speed. _VT is set. The voltage _{V T} is set lower than the voltage _{V F.} Further, the webbing take-up device 16 has a clutch mechanism provided in the driving force transmission mechanism 100 so that the take-up torque of the spool 40 is set based on the set tension of the webbing 14, and the set take-up torque is obtained. The frictional force between the clutch gear 128 and the clutch spring 130, that is, the outer diameter and the urging force of the clutch spring 130 are set. In the present embodiment, the winding torque of the spool 40 set at the time of the main try functions as an example of the first torque.

  When the webbing 14 is wound around and stored in the spool 40, for example, the occupant is stepping on the webbing 14, and the tongue 24 provided on the webbing 14 or the webbing 14 is caught by interior parts such as the seat 28 in the vehicle interior. A state in which the webbing 14 is sandwiched between the seat 28 and the occupant and the webbing 14 is sandwiched between the doors, that is, a state in which an external force that inhibits the winding of the webbing 14 is applied may occur. is there. In these cases, unwinding of the webbing 14 may occur.

  In the webbing take-up device 16, the webbing 14 is taken up when there is a take-up residue by performing a storage assist retry. In response to the retry, the ECU 172 is set with the limit value Ir of the drive current I so that the winding torque of the spool 40 is higher than that during the main try. The ECU 172 repeats the normal rotation of the motor 48 by a preset number of times until the drive current I of the motor 48 reaches the limit value Ir.

  Further, in order to reliably wind the webbing 14 during the retry, the winding torque of the spool 40 is larger than the winding torque during the main try, and the rotation speed of the spool 40 is higher than the rotation speed during the main try. Is preferred. However, when the winding torque of the spool 40 is too large and when the rotational speed of the spool 40 is too high, the webbing 14 is pulled strongly. For example, the webbing 14 is entangled with the passenger, Considering the possibility of being caught on a part, it is not preferable to pull the webbing 14 too strongly and quickly. From here, the webbing take-up device 16 performs a test or the like in consideration of the unwinding state of various webbings 14 with respect to the take-up torque and the rotational speed of the spool 40 at the time of retrying, without causing discomfort to the occupant. And it is set in the range which does not affect the components in a vehicle interior.

  In the ECU 172, the current value of the drive current I of the motor 48 that generates the winding torque set in the spool 40 at the time of retry is set as the limit value Ir, and the voltage Vr based on the rotation speed (the moving speed of the webbing 14). Is set. In the present embodiment, the winding torque set in the spool 40 at the time of retry functions as an example of the second torque. The determination time Ts is, for example, when the retry is executed in the winding end state in which the webbing 14 pulled out from the spool 40 is wound and stored until there is no longer length, the drive current I reaches the limit value Ir. It is set based on the time until. In the present embodiment, the determination time Ts functions as an example of the determination time.

  Hereinafter, winding of the webbing 14 using the motor 48 by the webbing winding device 16 will be described. The vehicle 12 may be equipped with a so-called child seat, which is an infant assist device, on the passenger seat and the rear seat. In this case, the fitting assist and the storage assist described below are omitted, and the detection of the buckle switch 174 is performed. General winding control based on the state may be performed. Whether or not the child seat is attached may be selected by providing a selection switch in the webbing take-up device 16 or the like.

  FIG. 5 shows an outline of the winding control of the webbing 14 in the webbing winding device 16. In this flowchart, in step 200, the open / closed state of the door 176 is confirmed, and in step 202, it is confirmed whether an occupant is seated on the seat 28. When an occupant gets on the vehicle 12, the door 176 is opened and then the door 176 is closed, and an output signal corresponding to the opening / closing operation of the door 176 is output from the door switch 178. Further, when the occupant who is on the vehicle sits on the seat 28, the output signal of the seat switch 180 is turned on.

  When the door 176 is closed, an affirmative determination is made at step 200, and when an occupant is seated on the seat 28 and an affirmative determination is made at step 202, the routine proceeds to step 204. In step 204, it is confirmed whether or not the buckle switch 174 is turned on. When the occupant wears the webbing 14 and engages the tongue 24 with the buckle 30, an affirmative determination is made in step 204, the process proceeds to step 206, and fitting assist control is executed.

  Here, even if the buckle switch 174 is on, the webbing 14 needs to be pulled out in order for the occupant to close the door 176 when the door 176 is open. Further, even when the buckle switch 174 is turned on, it is assumed that the occupant is not in an appropriate seating posture, for example, by lifting the waist from the seat 28A of the seat 28. From here, the webbing retractor 16 uses the door switch 178 and the seat switch 180 to predict whether or not the occupant is properly seated. Is determined to be engaged with the buckle 30, and the webbing 14 winding (fitting assist) is prevented from being started contrary to the passenger's intention.

  In this embodiment, an example in which the vehicle 12 is provided with the door switch 178 and the seat switch 180 and these are connected to the ECU 172 is described. However, one or both of the door switch 178 and the seat switch 180 are provided. In this case, the processing of the corresponding step may be omitted. That is, when the door switch 178 is not provided, the process of step 200 is omitted, when the seat switch 180 is not provided, the process of step 222 is omitted, and when the door switch 178 and the seat switch 180 are not provided, the step The processing of 220 and step 222 may be omitted.

  FIG. 6 shows an example of the fitting assist control executed in step 206. In step 220, the fitting assist reads the vehicle speed v output from the vehicle speed sensor 182 and confirms whether the vehicle speed v exceeds a preset speed vs. As the speed vs, a preset speed such as vs = 0 (km / h), vs = 5 (km / h) or vs = 10 (km / h) (for example, vs = 10 (km / h)) ) Applies.

  In step 222, the position of the shift gear detected by the shift position sensor 184 is read, and it is confirmed whether or not the position of the shift gear is the D range where the vehicle 12 travels forward or the position corresponding to the D range. In the case of a vehicle 12 equipped with an automatic transmission, it corresponds to non-forward running such as “P range”, “N range”, or “R range” (in the case of a manual transmission, “N position” and “R position”). In step 222, a negative determination is made.

  When the vehicle 12 moves forward and the vehicle speed v exceeds the speed vs (v> vs), an affirmative determination is made at step 220 and the routine proceeds to step 224. If the shift position of the vehicle 12 is a position corresponding to forward travel of the vehicle 12 such as “D range”, an affirmative determination is made in step 222 and the process proceeds to step 224.

When the ECU 172 proceeds to step 224, it performs fitting assist by rotating the motor 48 forward. The fitting assist, to set the drive voltage V to the voltage V _F, to operate the motor 48 in forward rotation by the driving voltage V set. As a result, the rotational force of the output shaft 48A of the motor 48 is transmitted to the spool 40 via the driving force transmission mechanism 60, the spool 40 is rotated in the winding direction, and the webbing 14 is wound around the spool 40 (fitting assist). Is started.

Thereafter, in step 226, it checks whether it has reached the limit current I _F which the drive current I of the motor 48 detected by the current sensor 186 is set in advance. Drive current I reaches the limit current I _F (I ≧ I _F), if an affirmative decision is made at step 226, the operation proceeds to Step 228 to end the fitting assist motor 48 is stopped.

By performing the fitting assist in this manner, the webbing 14 is brought into close contact with the occupant's body so as to obtain high occupant restraint, and the occupant can be reliably protected. Further, the limiting current I _F is that because the webbing 14 has been set based on no tension causing discomfort to the occupant (winding torque of the spool 40), thereby applying a load to be uncomfortable to the occupants There is no. Further, when the motor 48 is stopped, the urging force by the winding spring 112 is applied to the webbing 14, so that the passenger wearing the webbing 14 does not feel a pressure.

  In this embodiment, the vehicle speed sensor 182 and the shift position sensor 184 are used. However, one or both of the vehicle speed sensor 182 and the shift position sensor 184 may be provided. Processing may be omitted. Further, in place of the vehicle speed sensor 182 or the shift position sensor 184, fitting assistance may be performed by confirming whether or not the vehicle 12 has reached a state where it can travel using a parking brake switch or the like. Moreover, when the seatbelt apparatus 10 is provided with the buckle apparatus provided with the lift-up mechanism, the movement of the buckle 30 to the storage position may be included as a condition for starting the fitting assist. Thereby, by performing fitting assist before the buckle 30 moves to the storage position, it is possible to prevent the occupant from being further tightened by the webbing 14 when the buckle 30 moves to the storage position.

  By the way, as shown in FIG. 5, when the fitting assist control is completed, the routine proceeds to step 208. In step 208, the occupant confirms whether or not the engagement state between the tongue 24 and the buckle 30 is released in order to release the wearing state of the webbing 14. Here, when the engagement state between the tongue 24 and the buckle 30 is released, an affirmative determination is made in step 208, the process proceeds to step 210, and storage assist is executed.

  FIG. 7 shows an example of the storage assist control according to the present embodiment. The storage assist control is executed by shifting to step 210 in FIG. FIG. 8 shows an outline of a change in the drive current I of the motor 48 detected by the ECU 172 with respect to the time at the storage assist. In FIG. 8, the lower side from the origin of the drive current I (drive current I = 0) shows the current value in the reverse rotation, and the upper side from the origin shows the current value in the forward rotation.

  As shown in FIG. 7, in the storage assist control, in step 230, the vehicle speed detected by the vehicle speed sensor 182 is read to check whether or not the vehicle 12 is stopped. In step 232, the position of the shift lever is It is confirmed whether or not the vehicle is in the “P range” indicating the parking state of the vehicle. In step 234, it is confirmed whether the door 176 of the vehicle 12 is closed. When the vehicle speed v of the vehicle 12 is not v = 0, the vehicle is not stopped, and the occupant may wear the webbing 14 again. In addition, when the door 176 of the vehicle 12 is opened, it is considered that the occupant moves to get off, and the webbing 14 is wound around the spool 40 during the movement of the occupant, so that the webbing 14 becomes the body of the occupant. May be involved. Furthermore, when the position of the shift lever is a range where the vehicle can travel forward, such as “D range”, or when the position of the shift lever is “R range”, “N range”, etc., the vehicle 12 can start traveling forward. There is also a possibility that the occupant wears the webbing 14 again.

  In this way, when there is a possibility that the occupant will reattach the webbing 14 and when there is a possibility that the occupant may move his / her body to get out of the vehicle, the ECU 172 does not execute the storage assist of the webbing 14 and waits. To do. The ECU 172 monitors the state of the buckle switch 174. When the tongue 24 is engaged with the buckle 30 again, the ECU 172 ends the processing of this flowchart and shifts to fitting assist control.

  Here, for example, when the vehicle 12 is stopped, the shift lever is in the “P range”, and the opened door 176 is closed, if the determination in steps 230, 232, and 234 is affirmative, the storage is performed. Assist is executed.

In the storage assist, a main try is executed in step 236. In the storage assist main trie, the drive voltage V of the motor 48 is set to a preset voltage V _T , and the preset drive voltage V (V = V _T ) and a preset time Tm (for example, Tm = For about 2 seconds), the output shaft 48A of the motor 48 is operated to rotate in the reverse direction. As a result, the rotational force of the output shaft 48A of the motor 48 is transmitted to the spool 40 via the driving force transmission mechanism 100, and the spool 40 rotates in the winding direction to wind up and store the webbing 14.

  The driving force transmission mechanism 100 is provided with a clutch mechanism 122, and slipping occurs in the clutch mechanism 122 when the spool 40 reaches a winding torque that is preset or higher. Thereby, the spool 40 winds up the webbing 14 in a state where the winding torque is limited. Further, since the spool 40 is rotated at a rotational speed corresponding to the driving voltage V of the motor 48, when the webbing 14 is wound around the spool 40, the webbing 14 and the tongue 24 move smoothly. The operation time Tm of the motor 48 in the main trie is a time set based on the total length of the webbing 14, the winding speed of the webbing 14, and the like.

  As shown in FIG. 8, in the main trie, the winding torque of the spool 40 is limited by the clutch mechanism 122, so that the drive current I of the motor 48 exceeds the current value corresponding to the limited winding torque. There is nothing.

In FIG. 7, when the main try ends, the process proceeds to step 238, and a retry is executed at an interval of a preset time T _I (about several seconds, for example, T _I = 5 seconds). In the retry, the drive voltage V is set to a preset voltage Vr, and the limit value system Ir of the drive current I corresponding to the set drive voltage V (V = Vr) is set (I = Ir). Although the voltage Vr may be the voltage V _T , in the present embodiment, as an example, the voltage Vr is set higher than the voltage V _T (Vr> V _T ).

  In step 238, the output shaft 48A of the motor 48 is operated to rotate normally at the set drive voltage V (V = Vr), and time measurement is started. In the next step 240, the drive current I of the motor 48 is detected by the current sensor 186, and it is confirmed whether or not the detected drive current I has reached the limit value Ir.

  Here, when the drive current I reaches the limit value Ir, an affirmative determination is made at step 240 and the routine proceeds to step 242 where the motor 48 is temporarily stopped and one retry is completed. As shown in FIG. 8, when the motor 48 starts to rotate forward during the retry, the drive current I of the motor 48 increases according to the load that the spool 40 receives from the webbing 14. At this time, if there is a remaining webbing 14 that is not wound in the main trie, the drive current I becomes a current value necessary for winding the webbing 14, and the load increases as the winding of the webbing 14 progresses. To do.

  In FIG. 7, when one retry is completed, the process proceeds to step 244 to check whether the measured operation time T is equal to or less than a preset determination time Ts. If the operating time T exceeds the time Ts (T> Ts), a negative determination is made in step 244 and the process returns to step 238. Thereby, when the measurement time T is less than the determination time Ts, the retry is repeated as shown by a two-dot chain line in FIG. The retry may be terminated by reaching a preset number of times, and the elapsed time from the start of the retry for the first time is a preset time (for example, a range of several tens of seconds to several minutes). May be terminated by reaching a preset time).

  On the other hand, when the retry is executed in a state where the webbing 14 of the total amount of webbing 14 (the total length that can be wound) is wound on the spool 40, the drive current I of the motor 48 increases rapidly as shown in FIG. The limit value I is reached in a short time. That is, in the state where the webbing 14 is wound around the spool 40, the load on the spool 40 increases, the winding torque of the spool 40 increases rapidly, and the drive current I of the motor 46 also increases rapidly. The measurement time T is shortened.

  Further, when the webbing 14 in the middle of winding is caught on, for example, a shift lever or a side brake knob, the retry is executed and the webbing 14 is fully extended, so that the winding torque of the spool 40 is rapidly increased and measured. The time T reaches the determination time Ts or becomes shorter than the determination time Ts. In such a case, it is difficult to wind up the webbing 14 even if the retries are repeated. For example, before the occupant wears the webbing 14 next time, the occupant can unlock the catch of the webbing 14. It is valid.

  From this point, in step 244 of FIG. 7, when the measurement time T becomes equal to or less than the determination time Ts, it is determined that the storage of the webbing 14 has ended (positive determination), the retry is ended, and the storage assist is ended (step 246). ).

  Therefore, the webbing take-up device 16 can accurately determine the state in which the webbing 14 cannot be taken up, as well as the case where the entire amount of the webbing 14 has been taken up, and end the storage assist. Thereby, for example, the intermittent operation of the motor 48 is not unnecessarily repeated for winding the webbing 14, and the number of retries can be reduced. In addition, the intermittent operation of the motor 48 may be unnecessarily repeated, which may cause discomfort or discomfort to the occupant. However, since the retry can be completed at an appropriate timing, the occupant may feel discomfort. And no sense of incongruity.

  Further, in the webbing take-up device 16, for example, even when the webbing 14 is pinched by the door when a main try is executed, the webbing 14 remaining unwound is removed by releasing the pinching to the door during the retry. It can be wound and stored.

  Further, the ECU 172 of the webbing take-up device 16 measures the time until the drive current I of the motor 48 reaches the limit value Ir at the time of retry. For example, the ECU 172 detects the drive current I as time passes, Completion of winding of the webbing 14 can be determined easily and accurately as compared with the case where processing such as calculating the rate of change from the detected drive current I is performed.

  The present embodiment described above shows an example and does not limit the configuration of the present invention. For example, in this embodiment, the door switch 178, the vehicle speed sensor 182 and the shift position sensor 184 are used to check whether or not the storage assistance of the webbing 14 is possible. The result may be included. When the detection result of the seat switch 180 is included, it can be combined with the detection result of the door switch 178, for example. That is, the occupant disengages the tongue 24 and the buckle 30, then gets off and closes the door 176. From here, after the buckle switch 174 is turned off, the detection state of the door switch 178 changes from on (door 176 opened) to off (door 176 closed), and the door switch 178 is off. When it is detected that the vehicle is not seated on the seat 28 (the seat switch 180 is turned off), it can be determined that the storage assist start conditions in the door switch 178 and the seat switch 180 are satisfied.

  In the present embodiment, the vehicle speed sensor 182 is used. However, instead of the vehicle speed sensor 182, a parking brake sensor that detects the operation of the parking brake is used. When the parking brake is activated by the parking brake sensor, the vehicle It may be determined that 12 is stopped.

  Furthermore, in the present embodiment, it is determined whether or not the storage assist is started using the detection results of the door switch 178, the seat switch 180, the vehicle speed sensor 182 (or the parking brake sensor), and the shift position sensor 184. However, it is not limited to this. For example, at least one of a door switch 178, a seat switch 180, a vehicle speed sensor 182 and a shift position sensor 184 may be used. Further, none of the door switch 178, the seat switch 180, the vehicle speed sensor 182 and the shift position sensor 184 may be used. In these cases, the processing corresponding to the detection means that is not used may be omitted.

  In the present embodiment, the driving force transmission mechanism 60 including the clutch mechanism 82 is used as the first transmission means, and the clutch mechanism 122 is used as the second transmission means. However, the configurations of the first and second transmission means are as follows. It is not limited to these. If the first transmission unit is configured to transmit the rotation of the output shaft so that the winding shaft is rotated in the winding direction by rotating the output shaft of the driving unit in the first direction, Any configuration can be applied. Further, the second transmission means rotates the output shaft of the drive means in the second direction so that the rotation of the output shaft is transmitted when the winding shaft is rotated in the winding direction. Any configuration is applicable as long as the rotation of the output shaft is transmitted to the winding shaft within a range in which the winding torque of the winding shaft does not reach the preset first torque.

  Further, the transmission means is not limited to the first transmission means and the second transmission means, and at least is configured to transmit the rotation of the output shaft to the winding shaft and rotate the winding shaft in the winding direction. Any configuration can be applied.

10 seat belt device 14 webbing 16 webbing take-up device 24 tongue 30 buckle 48 motor 48A output shaft 60 driving force transmission mechanism 72 overload release mechanism 82 clutch mechanism 100 driving force transmission mechanism 122 clutch mechanism 170 control unit 172 ECU
174 Buckle switch 178 Door switch 180 Seat switch 182 Vehicle speed sensor 184 Shift position sensor 186 Current sensor

Claims (6)

The base end of the occupant restraining webbing is locked and rotated in the winding direction so that the webbing is wound and stored in layers, and the stored webbing is pulled out and rotated in the pulling direction. A winding shaft;
Detachment detecting means for detecting engagement and disengagement between a tongue provided on the webbing and a buckle fixed to the vehicle body;
A motor that includes an output shaft that rotates in a predetermined direction, and that rotates the output shaft in accordance with a supplied drive voltage;
Transmitting means for transmitting rotation of the output shaft of the motor to the winding shaft and rotating the winding shaft in the winding direction;
Current detection means for detecting the drive current of the motor;
When disengagement is detected by the attachment / detachment detection means, the drive voltage is supplied to rotate the output shaft of the motor, and the drive current detected by the current detection means reaches a predetermined limit value. The rotation of the output shaft is stopped, and a confirmation operation for measuring the time from the start of rotation of the output shaft to the rotation stop is executed, and the measurement time measured in the confirmation operation is applied to the winding shaft. When the output shaft is rotated in a state where the entire amount of the webbing is wound, control is performed so that the confirmation operation is repeated at a predetermined time interval until the output time becomes equal to or less than a determination time corresponding to the time from the start to the stop of rotation. Control means for terminating the confirmation operation when the measurement time is equal to or less than the determination time;
Including webbing take-up device. The control means rotates the output shaft of the motor prior to the confirmation operation, and rotates the output shaft after a time corresponding to the time that the entire amount of the webbing is wound on the take-up shaft has elapsed. Execute the pre-action to stop,
The webbing take-up device according to claim 1. In the preliminary operation, the control means supplies, to the motor, a voltage set so that the output shaft is rotated at a rotation speed at which the winding shaft has a preset winding speed as the driving voltage. To
The webbing take-up device according to claim 2. The motor rotates the output shaft in a first direction or a second direction opposite to the first direction according to the supplied drive voltage,
The transmission means transmits the rotation of the output shaft in the first direction to the winding shaft to rotate the winding shaft in the winding direction, and the output shaft The rotation in the second direction is transmitted to the winding shaft to rotate the winding shaft in the winding direction, and the winding torque of the winding shaft does not reach the preset first torque. Second transmission means for transmitting the output torque of the output shaft to the winding shaft within a range;
The control means supplies the drive voltage to the motor so as to rotate the output shaft in the second direction in the preliminary operation, and moves the output shaft in the first direction in the confirmation operation. Supplying the drive voltage to the motor for rotation;
The webbing take-up device according to claim 2 or 3 including the above. In the confirmation operation, the control means uses the limit value as a current value of a driving current of the motor that can obtain a second torque in which a winding torque of the winding shaft is higher than the first torque.
The webbing take-up device according to claim 4. At least one of opening / closing detection means for detecting opening / closing of the door, seating detection means for detecting whether or not an occupant is seated on the seat, vehicle speed detection means for detecting the vehicle speed, and shift position detection means for detecting the operation position of the shift lever. Including two detection means,
The control means starts supplying drive voltage to the motor based on the detection results of the attachment / detachment detection means and the detection means.
The webbing take-up device according to any one of claims 1 to 5, further comprising:

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