JP2007084021A - Webbing take-up device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a webbing take-up device capable of enhancing the comfortability when fitting the webbing by reducing the tension received by an occupant from the webbing when the webbing is fitted, and reducing the electric load on an on-vehicle power supply. <P>SOLUTION: When unfitting the webbing, the webbing 14 is firstly taken up by the urging force of a compact power spring 30 with the small spring constant, and the total amount of the webbing 14 is taken up by driving a drive motor 34 from the time when the take-up work by the power spring 30 is completed (when the urging force capable of performing the take-up is not affected). Thus, the tension received from the webbing 14 by an occupant is reduced when fitting the webbing, and the function as the tension reducer is also demonstrated. The electric addition to an on-vehicle power supply is also reduced since the drive motor 34 is not driven from the initial condition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a webbing take-up device capable of winding a webbing using a motor.

  For example, in a three-point seat belt device equipped for a front seat, one end of an occupant restraining webbing is locked to an anchor plate provided on the vehicle body floor, and the other end is provided near the lower part of the center pillar. The webbing take-up device is locked to the spool. An intermediate portion of the webbing is engaged with a shoulder anchor provided at an upper portion of the center pillar so as to be inserted therethrough, and a tongue plate is inserted into the intermediate portion.

  The occupant pulls the webbing against the urging force of the mainspring spring of the webbing take-up device by gripping the tongue plate, and engages the tongue plate with the buckle device standing on the side of the front seat, so that the lap side The webbing wearing state of the three-point seat belt device by the webbing and the shoulder side webbing can be achieved.

  Patent Document 1 below has a tension reducer function that winds up webbing slack with a spring to a degree that can reduce the feeling of pressure caused by webbing when the webbing is mounted, and winds the webbing with a motor when the webbing is stored. A motor-driven webbing take-up device is disclosed.

In this technology, when the tongue plate is detached from the buckle device, the second micro switch is turned on and the first micro switch is also turned on, so that the motor is driven. Even when the second micro switch is turned on by a capacitor provided in the circuit, the start of energization of the motor is delayed for a certain time. Thereby, it is possible to prevent the webbing from being taken up rapidly.
No. 7-32294

  However, in the case of the above prior art, the energization timing to the motor is determined by ON / OFF of the buckle switch, and the drive timing of the motor is delayed by a certain time using a capacitor. Winding of the webbing by the motor and winding of the webbing by the motor are performed at the same time, and there is a problem that the electric load on the in-vehicle power source increases.

  In consideration of the above-described facts, the present invention improves the comfort when wearing a webbing by reducing the tension that the occupant receives from the webbing when wearing the webbing, and further reduces the electrical load on the in-vehicle power source. Is the purpose.

  The webbing take-up device according to the first aspect of the present invention comprises a take-up shaft for taking up a webbing for restraining an occupant in layers, an urging means for urging the take-up shaft in the webbing take-up rotation direction, A motor that is connected to the take-up shaft via a drive force transmission path and that drives and rotates the take-up shaft in the webbing take-up rotation direction by applying a drive force; and a control unit that controls the drive of the motor. In the webbing take-up device, the urging force by the urging means is set to be weaker than the urging force required to take up the entire webbing on the take-up shaft, and the control means is provided by the urging means. The motor is driven and rotated so that the webbing that cannot be wound by the urging force is completely wound on the winding shaft.

  A webbing retractor according to a second aspect of the present invention is the buckle device according to the first aspect, wherein the control means is a buckle device in which a tongue plate inserted through an intermediate portion of the webbing is supported by a vehicle body or a vehicle seat. The motor is driven after a lapse of a predetermined time from the time when it is detached from the motor.

  According to the first aspect of the present invention, when the occupant wears the webbing, the webbing may be pulled out and mounted against the urging force of the urging means.

  When the occupant releases the webbing wearing state, the webbing is wound around the winding shaft by the biasing force of the biasing means.

  Here, in the present invention, since the urging force by the urging means is set to be weaker than the urging force required to wind up the entire amount of the webbing on the take-up shaft, the webbing is wound while the urging force is effective. Although it is wound around the take-up shaft, it is not taken up any further. However, in the present invention, since the motor is driven and rotated by the control means so that the webbing that cannot be wound by the urging force of the urging means is fully wound on the take-up shaft, the webbing is finally wound. It will be wound on the take-up shaft.

  In other words, since the motor is not driven and rotated while the urging force of the urging means contributes to the winding of the webbing, the webbing is taken up with the driving force of the motor and the urging force of the urging means overlapping. It will not be done. For this reason, as the urging means, one having a urging force weaker than that of the conventional full volume winding type can be used. Therefore, the webbing tension acting on the occupant when the occupant wears the webbing can be reduced, and the feeling of wearing the webbing can be reduced.

  In addition, since the motor is driven and rotated after the urging force of the urging means is used up effectively, the energization time to the motor is shortened compared to the configuration in which the motor is driven and rotated from the time when the webbing is released or in the vicinity thereof. Can do. Therefore, it is possible to reduce the electrical load on the in-vehicle power source.

  According to the second aspect of the present invention, the control means drives the motor after a predetermined time has elapsed since the tongue plate inserted through the intermediate portion of the webbing was detached from the buckle device supported by the vehicle body or the vehicle seat. Therefore, the timing for driving and rotating the motor from the time when the tongue plate is detached from the buckle device is determined. Therefore, it is not necessary to provide a special mechanism or sensor for measuring the timing for driving the motor.

  As described above, the webbing take-up device according to claim 1 includes a take-up shaft for taking up the occupant-restraining webbing in layers, and an urging means for urging the take-up shaft in the webbing take-up rotation direction. A motor connected to the take-up shaft via a driving force transmission path, and driving and rotating the take-up shaft in the webbing take-up rotation direction by applying a drive force; and a control means for controlling the drive of the motor. A webbing that is set so that the urging force of the urging means is weaker than the urging force required to wind up the entire amount of the webbing on the take-up shaft and cannot be wound by the urging force of the urging means by the control means Since the motor is driven and rotated so that the entire amount is wound on the take-up shaft, the comfort applied when wearing the webbing is reduced by reducing the tension that the passenger receives from the webbing when wearing the webbing. Improve, yet it has an excellent effect that it is possible to reduce the electrical load on the vehicle power supply.

  According to a second aspect of the present invention, there is provided the webbing retractor according to the first aspect of the present invention, wherein the control means includes a buckle device in which a tongue plate inserted through an intermediate portion of the webbing is supported by a vehicle body or a vehicle seat. Since the motor is driven after a lapse of a predetermined time from the time of separation, there is no need to provide a special mechanism or sensor for measuring the timing of driving the motor, and as a result, the webbing (total amount) can be wound at a low cost. It has an excellent effect that the system can be established.

  Hereinafter, an embodiment of a webbing take-up device according to the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 illustrates a schematic configuration of a webbing take-up device 10 according to the present embodiment in a side view. In this figure, each part is drawn in a simplified and schematic manner.

  As shown in this figure, the webbing take-up device 10 includes a frame 12 formed in a U shape in plan view. The frame 12 is fixed to the lower part of the center pillar with a bolt, so that the webbing take-up device 10 is attached to the vehicle body side.

  Both side portions 12A of the frame 12 extend in parallel with each other, and a winding shaft 16 that winds up an occupant-constrained webbing 14 in layers is rotatably supported between the both side portions 12A. In addition, although illustration is abbreviate | omitted, the resin cover is attached to the outer side of one side part 12A of the flame | frame 12, and the mainspring spring 30 as an urging means is accommodated in this cover. An inner end 30A of the mainspring spring 30 is engaged with an axial end portion of the winding shaft 16 (a spring engaging portion 18A of the connecting shaft 18 described later), and an outer end 30B of the mainspring spring 30 is attached to the resin cover. It is locked. Thereby, the mainspring spring 30 always urges the winding shaft 16 to rotate in the webbing winding rotation direction (arrow A direction).

  A known inertia lock mechanism (ELR) (not shown) configured to include an acceleration sensor is disposed outside the other side portion 12A of the frame 12. Therefore, when the vehicle suddenly decelerates, the ball of the acceleration sensor rolls, the pawl is pushed up, and the rotation of the V gear (lock wheel) (not shown) in the webbing pull-out direction is stopped. As a result, the lock plate moves outward in the radial direction, engages with the lock member, enters a locked state, and stops the rotation of the winding shaft 16 in the webbing pull-out direction.

  A connecting shaft 18 that is formed in a prismatic shape and has a small-diameter shaft-like spring locking portion 18A formed on the shaft core portion is coaxially and integrally attached to the end of the winding shaft 16 in the axial direction. ing. Further, a clutch case (not shown) is attached to one side 12 </ b> A of the frame 12 so as to surround the connecting shaft 18.

  In the clutch case, functional parts constituting a clutch mechanism such as a gear wheel 20, a ratchet 22, a pair of clutch pawls 24, a slider (unengaging member) (not shown), and a torsion coil spring 26 are accommodated.

  The ratchet 22 is formed in a disc shape, and a square hole 28 into which the connecting shaft 18 can be fitted is formed in the shaft core portion. The ratchet 22 is held by the winding shaft 18 with the connecting shaft 18 fitted in the square hole 28. Therefore, when the winding shaft 16 rotates, the ratchet 22 also rotates together.

  Further, worm teeth 20 </ b> A are formed on the outer peripheral portion of the gear wheel 20, and the driving force of the driving motor 34 is applied via the speed reduction mechanism 40. Specifically, a pinion 42 serving as an output gear is fixed to the output shaft 34 </ b> A of the drive motor 34, and the pinion 42 meshes with the large-diameter gear 44 of the speed reduction mechanism 40. A worm gear 48 is fixed to the support shaft 46 of the large-diameter gear 44, and the worm gear 48 meshes with the worm teeth 20 </ b> A on the outer peripheral portion of the gear wheel 20.

  Further, a clutch pawl 24 is pivotally supported on the side surface of the gear wheel 20 so as to be swingable around the support shaft 32. Therefore, when the gear wheel 20 rotates around the take-up shaft 16, the clutch pawl 24 also turns around the outer periphery of the take-up shaft 16. A torsion coil spring 26 that is grasped as an urging means in a broad sense is wound around the support shaft 32. One end of the torsion coil spring 26 is locked to the clutch pawl 24, and the other end is locked to the side surface of the gear wheel 20. Therefore, the torsion coil spring 26 always urges the clutch pawl 24 to rotate in a direction (arrow B direction) in which the engaging portion 24A meshes with the ratchet teeth 22A of the ratchet 22.

  When the drive motor 34 is not operated, a slider (unengaging member) (not shown) is connected to the base end of the clutch pawl 24 so that the engaging portion 24A of the clutch pawl 24 does not mesh with the ratchet teeth 22A of the ratchet 22. By interfering with the portion 24B, the clutch pawl 24 is held at a non-engagement position (a position rotated by a predetermined angle around the support shaft 32 in the direction opposite to the arrow B direction).

  The drive motor 34 described above is connected to a seat belt control ECU 50 as a control means, and its operation is controlled. Further, the seat belt control ECU 50 is connected to a buckle switch 52 provided in a buckle device supported in a standing state on the side of a vehicle body floor or a vehicle seat.

  Further, in the present embodiment, the urging force of the mainspring spring 30 described above is set to be weaker than the urging force necessary for winding the webbing 14 around the winding shaft 16. That is, in the webbing take-up device 10 according to the present embodiment, a spring having a smaller diameter and a smaller spring constant is used than a mainspring spring normally used in this type of webbing take-up device.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  In a state before the occupant wears the webbing 14, the engaging portion 24A of the clutch pawl 24 is held at a position where it does not engage with the ratchet teeth 22A of the ratchet 22 against the urging force of the torsion coil spring 26. Has been. Therefore, even if the winding shaft 16 rotates, the gear wheel 20 does not rotate.

  For this reason, the occupant pulls the tongue plate inserted through the webbing 14, pulls out the webbing 14 from the winding shaft 16 of the webbing winding device 10 against the urging force of the mainspring spring 30, and engages the buckle device. Thus, the webbing wearing state of the three-point seat belt device can be obtained. Note that when the tongue plate is engaged with the buckle device, the buckle switch 52 is turned ON, and a mounting detection signal is input to the seat belt control ECU 50.

  Thereafter, when the occupant presses the release button of the buckle device when getting off, the tongue plate is detached from the buckle device, the occupant is released from the webbing state, and the webbing 14 is wound around the take-up shaft 16. .

  Here, to explain in detail with reference to FIG. 2, in the present embodiment, a small spring spring 30 having a weak biasing force is used. It has an urging force equal to or greater than the urging force (belt winding force) F. For this reason, the webbing 14 is wound around the winding shaft 16 by a predetermined amount by the biasing force of the mainspring spring 30.

  At this time, when the tongue plate is detached from the buckle device, the buckle switch 52 is turned OFF, and the mounting release signal is input to the seat belt control ECU 50 (or the mounting detection signal is not input). As a result, the seat belt control ECU 50 starts the timer, measures the predetermined time T, and maintains the drive motor 34 in the non-operating state until the predetermined time T elapses. The predetermined time T is a belt winding force required for winding when the webbing 14 is wound up using a small spring spring 30 having a weak biasing force. It is the time to reach F.

  When the webbing 14 is wound only by the urging force of the mainspring spring 30 as described above, the winding operation of the webbing 14 is stopped when the belt winding amount of the retractor portion becomes L. Since the webbing winding operation by the mainspring spring 30 is temporarily stopped when the predetermined time T has elapsed, the seat belt control ECU 50 drives and rotates the drive motor 34. Thereby, winding of the webbing 14 by the drive motor 34 is started.

  When the drive motor 34 is driven forward and the pinion 42 is rotated counterclockwise (arrow C direction) in FIG. 1, the large-diameter gear 44 of the speed reduction mechanism 40 meshing with the pinion 42 is decelerated and rotated in the opposite direction. The worm gear 48 sharing the large diameter gear 44 and the support shaft 46 is rotated in the same direction (arrow D direction) as the large diameter gear 44. As a result, the gear wheel 20 is rotated in the arrow A direction (the direction opposite to the rotation direction of the worm gear 48), which is the webbing take-up rotation direction. When the gear wheel 20 rotates in the direction of arrow A, the engagement state between the clutch pawl 24 and the slider is released, the engagement portion 24A of the clutch pawl 24 engages with the ratchet teeth 22A of the ratchet 22, and the winding shaft 16 A driving force transmission path is connected. As a result, the entire webbing 14 is wound around the winding shaft 16 by the driving force of the driving motor 34.

  The drive motor 34 is automatically de-energized by the seat belt control ECU 50 when the time required for winding the entire webbing 14 has elapsed, and the winding operation of the webbing 14 is stopped.

  In other words, in this embodiment, the drive motor 34 is not driven and rotated while the urging force of the mainspring spring 30 contributes to the winding of the webbing 14, so that the driving force of the drive motor 34 and the mainspring spring 30 are not rotated. The webbing 14 is not taken up in a state where the urging force overlaps. In other words, in this embodiment, the urging force of the mainspring spring 30 is used to the extent that it can be used, and after the rotation of the winding shaft 16 in the webbing winding direction is temporarily stopped, the webbing winding of the winding shaft 16 by the drive motor 34 is performed. The taking direction rotation is resumed.

  Thereby, it becomes possible to use the mainspring spring 30 whose urging force is weaker than that of the conventional full-winding type. Accordingly, the pulling operation force of the webbing 14 when the occupant is wearing the webbing is also lightened, and after the webbing is worn, the webbing tension acting on the occupant can be reduced and the webbing feeling can be lightened (that is, the function as a tension reducer) can get).

  In addition, since the drive motor 34 is driven and rotated after the urging force of the mainspring spring 30 is used up effectively, the energization time to the drive motor 34 can be shortened. Therefore, it is possible to reduce the electrical load on the in-vehicle power source.

  As described above, according to the webbing take-up device 10 according to the present embodiment, the comfort of the webbing is improved by reducing the tension that the occupant receives from the webbing 14 when the webbing is worn, and the electric load on the in-vehicle power source is reduced. Can be reduced.

  Further, in the webbing take-up device 10 according to the present embodiment, when the tongue plate inserted through the intermediate portion of the webbing 14 is detached from the buckle device supported by the vehicle body floor or the vehicle seat (the buckle switch 52 is turned on) Since the drive motor 34 is driven after a lapse of a predetermined time (T) from the time when the signal is changed to the OFF signal, the timing for driving and rotating the drive motor 34 from the time when the tongue plate is detached from the buckle device is determined. Therefore, it is not necessary to provide a special mechanism or sensor for measuring the timing for driving the drive motor 34. As a result, according to the present embodiment, the system can be established at low cost.

  Further, in the webbing take-up device 10 according to the present embodiment, even if the power supply to the drive motor 34 is not ensured, the webbing 14 is taken up by the mainspring spring 30. Therefore, the webbing 14 is not stored or stored insufficiently. There is also an advantage that the webbing 14 can be prevented from being caught in the door.

  In the above-described embodiment, the timing for driving the drive motor 34 is set to T, which is the time point when the winding of the webbing 14 by the mainspring spring 30 is finished (the time point when the winding is stopped), but is not limited thereto. The drive motor 34 may be driven several seconds after the winding operation of the webbing 14 by the mainspring spring 30 is stopped.

  Further, in the above-described embodiment, the predetermined time T is measured by the timer of the seat belt control ECU 50 and the drive timing of the drive motor 34 is set. The belt winding amount detecting device 54 (see FIG. 1) for detecting the above may be set, and the drive motor 34 may be driven when the webbing winding amount by the mainspring spring 30 reaches a predetermined amount. As the belt winding amount detection device 54 in this case, a configuration in which a leaf spring is elastically pressed against the outer periphery of the shaft portion of the winding shaft 16 can be used.

It is a side view which shows the whole structure of the webbing winding device concerning this embodiment. It is a graph expressing the control content of the webbing take-up device according to the present embodiment.

Explanation of symbols

10 Webbing Winding Device 14 Webbing 16 Winding Shaft 18 Connecting Shaft (Winding Shaft)
20 Gear wheel (drive force transmission path)
22 Ratchet (drive force transmission path)
24 Clutch pawl (drive force transmission path)
26 Torsion coil spring (drive force transmission path)
30 Spring spring (biasing means)
34 Drive motor 40 Reduction mechanism (drive force transmission path)
42 Pinion (drive force transmission path)
44 Large-diameter gear (drive force transmission path)
48 Worm gear (drive force transmission path)
50 Seat belt control ECU (control means)
52 Buckle switch

Claims (2)

A winding shaft that winds up a webbing for restraining an occupant in layers;
Biasing means for biasing the winding shaft in the webbing winding rotation direction;
A motor that is connected to the winding shaft via a driving force transmission path and that rotates the winding shaft in the webbing winding rotation direction by applying a driving force;
Control means for controlling the driving of the motor;
A webbing take-up device comprising:
The urging force by the urging means is set to be weaker than the urging force required to wind up the entire amount of the webbing on the winding shaft,
The control means drives and rotates the motor so that the webbing that cannot be wound by the urging force of the urging means is fully wound on the winding shaft.
A webbing take-up device characterized by that. The control means drives the motor after a predetermined time has elapsed from the time when the tongue plate inserted into the intermediate portion of the webbing is detached from the buckle device supported by the vehicle body or the vehicle seat,
The webbing take-up device according to claim 1.

Images