JPH0571423B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic seat belt in which the tip of the webbing for restraining an occupant is guided by a guide rail provided on a vehicle body to automatically apply and release the webbing to the occupant. The present invention relates to a webbing drive device used in the device.

[Conventional technology]

A so-called automatic seat belt device has been proposed that automatically attaches and releases webbing to an occupant.

One end of the webbing is wound up by a take-up device placed in the center of the vehicle, and the other end of the webbing can be moved in the longitudinal direction of the vehicle along a guide rail placed near the roof side of the vehicle. The webbing is locked to a slider, and the slider is moved to attach or release the webbing.

In other words, when the slider moves toward the front of the vehicle on the guide rail, a space is created between the middle part of the webbing and the seat, and when the occupant sits on the seat, the slider moves toward the rear of the vehicle on the guide rail. Then, the webbing can be put on.

In this case, the slide is connected to a wire arranged along the guide rail, which in turn is connected to a rotating drum of a drive arranged in the lower part of the side wall of the vehicle. When the drive device is operated, the rotating drum is rotated by the motor to wind up or unwind the wire, and the slider moves accordingly.

The stop position of the slider corresponding to the webbing attachment position of the occupant is detected by a limit switch attached to the adjuster and stopped. This adjuster is locked at a predetermined position on the guide rail, and the locking mechanism is activated at the same time as the slider stops, thereby fixing the webbing to the vehicle body via the slider and adjuster.

As described above, the stop position of the webbing, that is, the slider, is determined by the locking position of the adjuster, so it is necessary to change the locking position of the adjuster according to the different physiques of the occupants. At this time, when the webbing is attached, that is, when the slider is locked to the adjuster, the slider must be moved together with the adjuster.

However, the slider is connected to a wire that moves it, which in turn is connected to a drive motor. As a result, the slider is prevented from moving, and the webbing mounting position cannot be adjusted in accordance with the physique of the occupant.

[Problem that the invention seeks to solve]

In consideration of the above-mentioned fact, the present invention moves the adjuster together with the slider without applying any load to the motor in a state where the slider that locks one end of the webbing is locked to the adjuster and the webbing is attached to the passenger. It is an object of the present invention to obtain a webbing drive device that allows the height of a webbing locking position to be freely adjusted.

[Means for solving problems]

The webbing drive device according to the present invention includes a guide rail disposed along the longitudinal direction of the vehicle on the roof side of the vehicle, and a webbing movably disposed within the guide rail, and one end of the webbing for restraining an occupant is locked. An automatic seat belt device comprising: a slider; and an adjuster arranged near the end of the guide rail on the rear side of the vehicle, capable of locking the slider, and adjusting the locking position in the vehicle height direction. The rope connected to the slider is wound up and unwound by a drum connected to the rotary drive shaft of the motor, thereby moving the webbing in the longitudinal direction of the vehicle along the guide rail to provide a seat to the occupant. An automatic device and a webbing drive device for releasing the webbing, which is provided between the rotary drive shaft and the drum, and connects the rotary drive shaft and the drum when the slider moves along the guide rail to stop the rotation. The rotary drive shaft and the drum are connected by transmitting the rotation of the drive shaft to the drum and actuated by a signal issued when adjusting the height of the adjuster with the slider being locked to the adjuster. The present invention is characterized in that it includes a clutch that releases the rotational drive shaft and interrupts transmission of rotational force between the rotational drive shaft and the drum.

[Effect]

In the webbing drive device configured as described above, when moving the webbing to attach and detach the webbing to and from an occupant, the drum and the rotational drive shaft are connected by the clutch, and driving force is transmitted. As a result, the slider moves in the longitudinal direction of the vehicle along the guide rail, and the webbing can be automatically unattached.

When the adjuster is moved with the slider that locks one end of the webbing locked on the adjuster and attached to the passenger, the clutch is actuated by the signal emitted when adjusting the height, and the rotational drive shaft and drum are moved. The connection between Therefore, even if the cable moves together with the adjuster and slider, this moving force is only transmitted to the drum and not to the rotational drive shaft. Therefore, the rotary drive shaft does not obstruct the movement of the drum, cable, slider, and adjuster, and the height of the webbing locking position of the adjuster can be adjusted by moving the adjuster together with the slider without applying any load to the motor. You can do it freely.

〔Example〕

FIG. 1 shows an exploded perspective view of a webbing drive device 10 according to a first embodiment of the present invention, and FIG. 2 shows an automatic seat belt device to which the webbing drive device 10 is applied. There is.

A guide rail 14 is provided on the roof side 12 of the vehicle.
is located. The leading end of the guide rail 14 extends along the front pillar 16, and the rear end is bent at a substantially right angle along the center pillar 18. A slider 20 is slidably disposed within the guide rail 14, and one end of a webbing 22 is locked therein. The other end of the webbing 22 is wound in layers with a predetermined biasing force by a winding device 24 disposed in the center of the vehicle. This take-up device 24 has a built-in inertia lock mechanism that instantly stops pulling out the webbing 22 in case of a vehicle emergency.

A wire receiving groove (not shown) is formed in the guide rail 14, and the wire 26, which is a cable, is tightly accommodated and slidably guided in the longitudinal direction of the guide rail 14. The tip of this wire 26 is locked to the slider 20.
is adapted to move together with the wire 26. The other end of the wire 26 is connected to the center pillar 18.
Webbing drive device 10 attached to the lower end of
is connected to. This webbing drive device 10
The wire 26 receives the driving force from the guide rail 14
The slider 20 slides inside the slider 20.
is designed to move toward the front or rear of the vehicle.

An adjuster 2 is installed near the rear end of the guide rail 14.
8 is placed. The adjuster 28 can slide on the guide rail 14 within a set range, and can be fixed at any position within the sliding range by operating a knob located outside. There is. Further, the adjuster 28 has a locking mechanism and can be engaged with the slider 20. Therefore, when the slider 20 moves along the guide rail 14 to the rear end of the guide rail 14 (ie, the position where the adjuster 28 is disposed), the slider 20 engages with the adjuster 28 and is fixed to the vehicle body.

In this way, the slider 20 is connected to the guide rail 14.
When the occupant is moved to the front end of the vehicle, a space is created between the webbing 22 and the seat, allowing the occupant to sit on the seat easily. After the occupant is seated, the slider 20 is moved by the webbing drive device 10. The guide rail 14 is then moved to the rear end of the vehicle, and is further engaged with the adjuster 28 and fixed to the vehicle body.
The occupant can wear the webbing.

Now, the webbing driving device 10, which is a means for driving the slider 20, that is, the wire 26, will be explained.

As shown in FIGS. 1, 3, and 4, the main body 30 of the webbing drive device 10 is formed into a substantially cylindrical shape with one end open, and a small diameter portion 34 protrudes from the bottom wall of a large diameter portion 32. It is formed. Small diameter part 3
A shaft 36 is fixed to the center of the bottom wall of 4 so as to protrude toward the large diameter portion 32. A worm wheel 38 is disposed within the small diameter portion 34 and is rotatably supported on a shaft 36 via a bush 39 . This worm wheel 38 meshes with a worm gear 42 coaxially attached to the drive shaft of a motor 40, so that the driving force of the motor 40 is transmitted. Furthermore, engagement protrusions 38A are formed at the end of the worm wheel 38 so as to protrude at equal intervals over the entire circumference. An outer drum 44 is disposed within the large diameter portion 32.

The outer drum 44 is formed in a cylindrical shape,
The shaft 36 passes through the center of the interior. A clutch portion 46 is disposed between the outer drum 44 and the worm wheel 38.

As shown in FIG.
and a lever 50. The electromagnet 48 is formed in an annular shape and is attached to the bottom 4 of the outer drum 44 so as to protrude toward the worm wheel 38.
It is fixed to 4A. Therefore, the electromagnet 48 is integrated with the outer drum 44. Electromagnet 48
A lever 50 is rotatably supported on the bottom portion 44A between the engagement protrusion 38A of the worm wheel 38 and the engagement projection 38A of the worm wheel 38. The lever 50 is an L-shaped member with a tip 5.
2 is the engagement protrusion 38A of the worm wheel 38
It is now possible to engage with

Further, the end corner portion 54 of the lever 50 corresponding to the electromagnet 48 is made of a magnetic material and is adapted to be sensitive to the magnetic force of the electromagnet 48. A torsion coil spring 56 is interposed between the lever 50 and the bottom portion 44A of the outer drum 44, and biases the tip portion 52 of the lever 50 in the direction in which it engages with the engagement protrusion 38A of the worm wheel 38, that is, in the axial direction. There is. Therefore, under normal conditions, the lever 50 is connected to the worm wheel 38.
The worm wheel 38 and the outer drum 44 are engaged with each other so that the worm wheel 38 and the outer drum 44 rotate integrally via the lever 50. However, when the electromagnet 48 is energized, the lever 50 is torsioned by the magnetic force and the biasing force of the coil spring 56 is applied. When the lever 50 rotates against the phantom line in FIG. 5, the engagement between the lever 50 and the worm wheel 38 is released, and the worm wheel 38 and the outer drum 44 rotate relative to each other.

A guide plate 5 is installed inside the outer drum 44.
8 is accommodated. The guide plate 58 is formed into a disk shape, and furthermore, a female threaded portion 58A is formed in the center. This female threaded portion 58A is a male threaded portion 36A formed at the intermediate portion of the shaft 36.
It is screwed together with the shaft 36, and can be moved in the axial direction of the shaft 36 by rotation. In this case, the thread pitches of the male threaded portion 36A and the female threaded portion 58A are set so that the guide plate 58 can move in the axial direction by the same amount as the outer diameter of the wire 26 every time it rotates.

Further, on the outside of the female threaded portion 58A of the guide plate 58, fan-shaped guide holes 60 whose inner circumferential walls are arcuate from the same axis of the guide plate 58 are formed at three locations spaced apart from each other. In these guide holes 60, an inner drum 62, which is erected and integrally fixed to the bottom portion 44A of the outer drum 44, is fitted, and the guide plate 58 is configured to rotate via the inner drum 62. There is.

An auxiliary plate 59 is fixed to the guide plate 58, and the end of the wire 26 is secured to the edge of the auxiliary plate 59 by a holder 64. Therefore, as the guide plate 58 rotates, the wire 26 is guided between the inner wall of the outer drum 44 and the outer wall of the inner drum 62, and the wire 26 is overlapped by the axial movement of the shaft 36 of the guide plate 58. It is designed so that it can be wound onto the inner drum 62 without any damage. Note that the distance between the inner wall of the outer drum 44 and the outer wall of the inner drum 62 is slightly larger than the outer diameter of the wire 26, and this also prevents the wire 26 from being wound twice. ing. Furthermore, the inner wall of the outer drum 44 and the guide plate 5
The distance between wire 2 and the outer peripheral edge of wire 2 is narrow.
6 will not get in between these.

The opening of the main body 30 is covered by a cover 66, thereby sealing the main body 30.

Incidentally, when the slider 20 is located at the end of the guide rail 14 on the front side of the vehicle, the motor 40 operates as follows.
It is designed to be activated when the door is closed after the occupant is seated. Furthermore, when the slider 20 is located at the rear end of the guide rail 14, the motor 40 is activated when the occupant opens the door. At this time, the drive shaft of the motor 40 is rotated in the opposite direction to that in the above case. The operation of these motors 40 is stopped when the slider 20 is moved and comes into contact with the vehicle front end or the vehicle rear end of the guide rail 14.

Further, the electromagnet 48 is energized by operating a knob arranged on the adjuster 28 for fixing the adjuster 28. That is, when the knob is pulled and the adjuster 28 becomes slidable, the power is applied, and when the knob is pushed and the adjuster 28 is fixed, the power is turned off.

Next, the operation of this embodiment will be explained.

When no occupant is on board, the slider 20 is located at the end of the guide rail 14 on the vehicle front side. In this state, the guide plate 58 of the webbing drive device 10 is attached to the bottom 44 of the outer drum 44.
It is stopped at the farthest point from A, that is, on the cover 66 side.

When the occupant takes a seat and closes the door, the motor 40 is activated. When the motor 40 operates, the worm wheel 38 rotates via a worm gear 42 coaxially attached to the drive shaft. At this time, due to the biasing force of the torsion coil spring 56, the tip portion 52 of the lever 50 is pushed against the engagement protrusion 3 of the worm wheel 38.
It is engaged with 8A. Therefore, the rotational force of the worm wheel 38 is transmitted to the outer drum 44 and the inner drum 62 via the lever 50. Furthermore, along with this, the guide plate 58
is rotated by the driving force of the motor 40 via the inner drum 62. This allows the wire 26
is guided by the inner wall of the outer drum 44 and the outer wall of the inner drum 62 and wound onto the inner drum 62.

In this case, the guide plate 58 moves the wire 26 toward the bottom 44A side of the outer drum 44 every time the guide plate 58 is rotated.
It moves according to the amount of winding onto the inner drum 62. The wire 26 is therefore tightly wound in a helical manner.

When the wire 26 is wound around the inner drum 62 of the webbing drive device 10, the slider 20 connected to the wire 26 is pulled by the wire 26, so that it is guided by the guide rail 14 and moves toward the rear of the vehicle. . Accordingly, the end of the webbing 22 on the slider side also moves accordingly.

This movement of the slider 20 is continued until the slider 20 abuts the end of the guide rail 14 on the vehicle rear side. That is, when the slider 20 reaches the end of the guide rail 14, the operation of the motor 40 is stopped, and the slider 20 is further engaged with the adjuster 28 and fixed to the vehicle body. As a result, the webbing 22 is placed in an attached state with the portion between the slider 20 and the take-up device 24 positioned on the chest of the occupant.

In this state, the occupant can adjust the optimal mounting position of the webbing 22 according to his/her physique by sliding the adjuster 28.
That is, at the same time as the knob disposed on the adjuster 28 is pulled, the electromagnet 48 in the webbing drive device 10 is energized. As a result, a magnetic force is generated in the electromagnet 48, and the tip end corner 54 of the lever 50 is pulled against the biasing force of the torsion coil spring 56 and rotated in the direction of arrow A in FIG. Therefore, the engagement between the tip portion 52 and the engagement protrusion 38A is released, and the outer drum 44
and the worm wheel 38 can rotate relative to each other. Therefore, the outer drum 44 can rotate relative to the motor 40, and the wire 26 wound around the inner drum 62 can be freely unwound without applying a load to the motor 40. Therefore, the adjuster 28 can be slid on the guide rail 14 and can be adjusted according to the physique of the occupant.

After completing the adjustment, push the knob again and adjust the adjuster 28.
At the same time as the electromagnet 48 is fixed, power to the electromagnet 48 is stopped. Therefore, the lever 50 that has been attracted by the magnetic force of the electromagnet 48 is rotated in the opposite direction to that when energized by the biasing force of the torsion coil spring 56, and the tip portion 52 is rotated in the opposite direction to the engaging protrusion 38A of the worm wheel 38.
engage with. Therefore, the outer drum 44 and the worm wheel 38, ie, the motor 40, are integrally connected.

When a passenger opens the door to exit the vehicle, the motor 40 is activated. In this case, the drive shaft of the motor 40 is rotated in the opposite direction to that when the passenger rides the vehicle. Furthermore, since the worm wheel 38 and the outer drum 44 are integrally connected via the lever 50, the rotational force of the motor 40 is transmitted to the outer drum 44 via the lever 50.
4. Inner drum 62 and guide plate 58
transmitted to. Therefore, the wire 26 that has been wound around the inner drum 62 is again guided by the inner wall of the outer drum 44 and the outer wall of the inner drum 62 and is unwound. Further, the guide plate 58 is connected to the wire 26
Because it moves to the cover 66 side according to the amount of unwinding,
The wire 26 is unwound while maintaining its tightly wound state.

When the wire 26 is unwound from the inner drum 62 of the webbing drive device 10, the slider 20 connected to the wire 26 is pushed by the wire 26 and moves toward the front of the vehicle along the guide rail 14. Accordingly, the end of the webbing 22 on the slider side also moves accordingly.

This movement of the slider 20 is continued until the slider 20 comes into contact with the vehicle front side end of the guide rail 14. That is, when the slider 20 reaches the end of the guide rail 14, the operation of the motor 40 is stopped, and the webbing 22 is thereby released from the attached state and returned to the state completely separated from the passenger, waiting for the next webbing 22 to be attached. state.

As described above, in this embodiment, when adjusting the mounting position of the webbing 22 according to the physique of the occupant using the adjuster 28, the wire 22 is adjusted using the lever 50.
6 and the motor 40, the adjuster 28 can be freely slid and adjusted without applying a load to the motor 40.

Next, other embodiments of the present invention will be described. Note that basically the same things as the first embodiment include:
The same reference numerals as in the first embodiment are given, and the explanation thereof is omitted.

A second embodiment of the invention is shown in FIGS. 6 and 7. Small diameter portion 3 of webbing drive device 70
A worm wheel 72 is rotatably supported on the shaft 36 via the bush 39 and is disposed within the worm wheel 4 . This worm wheel 72 meshes with a worm gear 42 coaxially attached to the drive shaft of the motor 40, so that the driving force of the motor 40 is transmitted.

A cantilevered arm portion 74 is formed at the tip of the worm wheel 72 by a notch. Arm portion 74
is elastically deformed and movable in the radial direction of the worm wheel 72. A tip corner portion 76 inside the tip of the arm portion 74 is formed of a magnetic material. Furthermore, an L-shaped engaging claw 78 is formed at the tip of the arm portion 74 and projects outward.

A protrusion 8 is formed from the bottom 44A of the outer drum 44.
0 protrudes toward the worm wheel 72, and an engagement groove 81 is continuously formed on the inner periphery of the protrusion 80. Normally, the engagement claw 78 of the worm wheel 72 engages with the engagement groove 81 to transmit the rotation of the worm wheel 72.

An electromagnet 82 is arranged inside the tip of the worm wheel 72 so as to correspond to the tip corner 76 . The electromagnet 82 is energized at the same time as the knob disposed on the adjuster 28 is operated, as in the first embodiment. Therefore, under normal conditions, the engaging claw 78 engages with the protrusion 80 and the worm wheel 72 and outer drum 44 rotate integrally, but the electromagnet 82
When energized, the arm portion 74 is elastically deformed by the magnetic force, and the engagement claw 78 comes out of the protrusion 80 as shown by the imaginary line in FIG. It is designed to rotate relative to the

In this embodiment as well, the passenger can use the adjuster 28
The optimal webbing 22 is created by sliding the
The mounting position can be adjusted. That is,
At the same time as the knob disposed on the adjuster 28 is pulled, the electromagnet 82 is energized and a magnetic force is generated, which causes the arm 74 with the tip end corner 76 of the arm 74 to be elastically deformed and the worm wheel 72 move in the direction of the axis. Therefore, the engaging claw 78 is disengaged from the protrusion 80, and the outer drum 44 and the worm wheel 72 begin to rotate relative to each other. Therefore, the wire 26 can be unwound and the position of the adjuster 28 can be adjusted without applying any load to the motor 40.

A third embodiment of the present invention is shown in FIGS. 8-12.

A worm wheel 92 is rotatably disposed within the small diameter portion 34 of the webbing drive device 90. A pair of wedge-shaped engagement grooves 94 are formed on the outer periphery of the tip of the worm wheel 92 so as to face each other. Further, a recess 96 is formed in the bottom portion 44A of the outer drum 44 at a position corresponding to the engagement groove 94. A piece 98 is fitted into this recess 96 via a compression coil spring 100.

The tip 98A of the piece 98 is tapered into a wedge shape, and when the engagement groove 94 of the worm wheel 92 is in the opposing position, the tip 98A is pressed by the biasing force of the compression coil spring 100.
A fits into the engagement groove 94.
In this state, a portion of the tip portion 98A protrudes from the axial end portion of the worm wheel 92. In this case, the length of the piece 98 is set such that the rear end 98B of the piece 98 is still located within the recess 96. Therefore, the tip 98A of the piece 98
When the outer drum 44 and the worm wheel 92 are fitted into the engagement groove 94, the outer drum 44 and the worm wheel 92 rotate together through the piece 98.

A disc-shaped release plate 102 is disposed between the worm wheel 92 and the outer drum 44 and is supported by a shaft portion 103 that passes through the axis of the worm wheel 92 and is rotatable relative to the worm wheel 92. There is. For this reason, the release plate 102
is also rotatable relative to the worm wheel 92. This release plate 102 is formed so that its outer diameter is slightly smaller than the outer diameter of the worm wheel 92. Furthermore, release plate 1
The engagement groove 9 of the worm wheel 92 is provided on the outer periphery of the worm wheel 92.
A distal end portion 9 protruding from the axial end of the worm wheel 92 with release grooves 104 having the same shape as the engagement grooves 94 formed at positions corresponding to 4 and facing each other.
Part of 8A can fit inside. When the piece 98 is fitted into the engagement groove 94, the tip 98A is also fitted into the release groove 104.
When the driving force of the motor 40 is transmitted to the worm wheel 92, the release plate 102 rotates together with the worm wheel 92. Further, when rotational force is transmitted only to the release plate 102 from another drive source to be described later, the release groove 10
4 comes into contact with the tip 98A of the piece 98,
A compression coil spring 100 as shown in FIG.
The piece 98 is pressed and moved in the direction of the recess 96 against the urging force of. When the outer drum 44 is rotated in this state, as shown in FIG.
4, the fitting is released, and the outer drum 4
4 and the worm wheel 92 can now rotate relative to each other.

A pair of substantially fan-shaped through holes 106 are bored in the middle part of the release plate 102. One end of a tension coil spring 108 is locked near one end edge of the through hole 106 . The other end of the tension coil spring 108 passes through the through hole 106 and is then locked to the worm wheel 92 . Further, a stopper pin 109 projects from the worm wheel 92 into the through hole 106, and is in contact with one end corner of the through hole 106. For this reason, the release plate 10
2 is rotatable with respect to the worm wheel 92 only in a direction that resists the biasing force of the tension coil spring 108 (in the direction of arrow A in FIG. 9). The tension coil spring 108 is attached with reference to the state in which the release groove 104 of the release plate 102 overlaps the engagement groove 94 of the worm wheel 92, and the release plate 102 overlaps the engagement groove 94 of the worm wheel 92.
Only when the engagement groove 94 and the release groove 104 are rotated relative to each other, a biasing force is exerted in the direction in which the engagement groove 94 and the release groove 104 overlap.

A substantially disc-shaped gear plate 110 is fixed to the rear end portion of the shaft portion 103 (on the opposite side from the outer drum 44). Therefore, the gear plate 110 is
03 to rotate integrally with the release plate 102. As shown in FIG. 10, serrated teeth 112 are formed on the outer periphery of the gear plate 110. Furthermore, a solenoid 114 is disposed on the main body 30 near the gear plate 110 so as to be able to engage with the toothed portion 112 . This solenoid 114
When the rod 116 is energized, the rod 116 protrudes in the axial direction. Therefore, when the solenoid 114 is energized and activated, the rod 116
is pressed to rotate the gear plate 110 by one tooth with the tooth portion 112.

Further, the solenoid 114 is electrically connected to a knob for fixing the adjuster 28 disposed on the adjuster 28, as in the first embodiment, and is energized by operating the knob.

Next, the operation of this embodiment will be explained.

In order to adjust the mounting position of the webbing 22, the passenger pulls the knob located on the adjuster 28, and at the same time, the solenoid 114 is energized and the rod 11 is energized.
6 slides. Therefore, the tooth portion 112 of the gear plate 110 is pressed by the rod 116, causing the gear plate 110 to rotate. Therefore, the release plate 102, which is integrated with the gear plate 110 via the shaft portion 103, rotates against the biasing force of the tension coil spring 108. When the release plate 102 rotates, the side wall of the release groove 104 comes into contact with the tip 98A of the piece 98, and as shown in FIG. 11, the piece 98 is pushed and moved in the direction of the recess 96 against the urging force of the compression coil spring 100. .

When the occupant moves the adjuster 28 in this state, the outer drum 44 is rotated by the wire 26 connected to the adjuster 28, and the tip 98A of the piece 98 is completely disengaged from the engagement groove 94 as shown in FIG. become. Therefore, the outer drum 4
4 and the worm wheel 92 can rotate relative to each other, and the wire 2 can be rotated without applying a load to the motor 40.
6 can be unwound and the position of the adjuster 28 can be adjusted.

When the adjustment of the mounting position of the webbing 22 is completed and the adjuster 28 is locked, the energization to the solenoid 114 is stopped, and the rod 116 is thereby moved to its original position. For this reason, the release plate 10
2 rotates in the opposite direction to that described above by the biasing force of the tension coil spring 108, and stops at a position where the engagement groove 94 and the release groove 104 overlap again. Further, when the outer drum 44 or the worm wheel 92 is slightly rotated manually or by motor driving force, the piece 98 is fitted into the engagement groove 94 again, and the worm wheel 92 and the outer drum 44 can be rotated integrally, and the motor 40 is driven. Be able to transmit power.

A fourth embodiment of the invention is shown in FIGS. 13 and 14.

A worm wheel 122 is rotatably disposed within the small diameter portion 34 of the wevig drive device 120. A pair of solenoids 124 are arranged on the outer periphery of the tip of the worm wheel 122 at positions facing each other and are connected to a vehicle power source via sliding contacts (not shown). The solenoid 124 has a rod 126, and normally this rod 126 protrudes outward in the radial direction of the worm wheel 122, but when energized, the rod 126
6 moves in the axial direction and retracts. The solenoid 124 is electrically connected to a knob for fixing the adjuster 28 disposed on the adjuster 28, as in the previous embodiment, and is energized by operating the knob.

Further, as shown in FIG. 14, a ring-shaped protrusion 128 is formed to protrude from the bottom 44A of the outer drum 44, and a plurality of recesses 130 that can be engaged with the rods 126 are formed on the inner periphery of the protrusion 128. It is formed by intervals. Usually this recess 130
A rod 126 is fitted into the outer drum 44 so that the outer drum 44 rotates integrally with the worm wheel 122.

In this embodiment as well, when the rider operates the adjuster 28, the solenoid 124 is actuated, and the rod 126 comes out of the recess 130 to release the engagement, thereby allowing the outer drum 44 and the worm wheel 122 to rotate relative to each other. Become. Therefore, the wire 26 can be unwound and the position of the adjuster 28 can be adjusted without applying a load to the motor 40.

A fifth embodiment of the present invention is shown in FIGS. 15 and 16.

A worm wheel 172 is rotatably disposed within the small diameter portion 34 of the webbing drive device 170. The tip of the worm wheel 172 has a first small diameter part 172A and a second small diameter part 17, which have successively smaller diameters.
2B is formed. A ring-shaped electromagnet 174 is fixed to the first small diameter portion 172A. The electromagnet 174 is energized at the same time as a knob disposed on the adjuster 28 is operated.

Further, a pair of slide grooves 175 are formed in the second small diameter portion 172B in the axial direction, and a clutch ring 176 is further disposed. The clutch ring 176 is a substantially ring-shaped magnetic material and is formed with a pair of guide protrusions 177 protruding inward. This guide protrusion 177 corresponds to the slide groove 17.
5 so that the clutch ring 176 can slide in the axial direction of the second small diameter portion 172B, and at the same time, the clutch ring 176 and the second small diameter portion 172B, that is, the worm wheel 172, rotate integrally. It's getting old.

In addition, the outer drum 4 of the clutch ring 176
Convex portions 178 are formed at the end portion on the fourth side to protrude at equal intervals over the entire circumference.

A compression coil spring 180 is disposed between the electromagnet 174 and the clutch ring 176. Therefore, the clutch ring 176 is always biased in a direction away from the electromagnet 174 (toward the outer drum 44).

An engaging protrusion 182 is formed on the bottom portion 44A of the outer drum 44 so as to protrude toward the worm wheel 172. A recess 184 having a size corresponding to the protrusion 178 is formed at the tip of the engagement protrusion 182, and is capable of engaging with the protrusion 178. Therefore, under normal conditions, the compression coil spring 1
80, the convex portion 178 and the concave portion 184 fit together, and the outer drum 44 and the worm wheel 172 rotate integrally. However, when the electromagnet 174 is energized, the clutch ring 176 is attracted. The outer drum 44 and the worm wheel 1 move against the biasing force of the compression coil spring 180, and the convex portion 178 and the concave portion 184 are disengaged from each other.
It is designed to be able to rotate relative to 72.

In this embodiment as well, normally the outer drum 44 and the worm wheel 172 rotate integrally due to the engagement between the convex portion 178 and the concave portion 184;
When the passenger operates the adjuster 28, the electromagnet 174
is activated, the fitting between the convex portion 178 and the concave portion 184 is released, and the outer drum 44 and the worm wheel 17
2 can be rotated relative to each other. Therefore, the wire 26 can be unwound without applying a load to the motor 40.

The webbing drive device according to the present invention is not limited to the one having the clutch described above, but may have another type of clutch.

〔Effect of the invention〕

As explained above, in the webbing drive device according to the present invention, the rotation of the rotary drive shaft is transmitted to the drum between the rotary drive shaft and the drum, and when the height of the adjuster is adjusted with the slider locked, this Since it is equipped with a clutch that cuts off the transmission of rotational force between the rotational drive shaft and the drum, when the slider that reduces one end of the webbing is locked to the adjuster and the webbing is attached to the passenger, no load is applied to the motor. This has an excellent effect in that the height of the webbing locking position of the adjuster can be freely adjusted by moving the adjuster together with the slider without adding additional force.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a webbing drive device according to a first embodiment of the present invention, FIG. 2 is a schematic diagram showing an automatic seat belt to which the webbing drive device of the present invention is applied, and FIG. 3 is a diagram of the present invention. FIG. 4 is a sectional view taken along the line of FIG. 3, and FIG. 5 is a cross-sectional view of the webbing drive device according to the first embodiment.
6 is a sectional view taken along the line of FIG. 6, FIG. 7 is a sectional view taken along the line of FIG. 6, and FIG. 8 is a sectional view of the third embodiment. 9th
The figure is a sectional view taken along the line of Fig. 8, Fig. 10 is a sectional view taken along the line of Fig. 8, and Fig. 11 is a sectional view taken along the line of Fig. 3.
FIG. 12 is an enlarged sectional view showing the state in which the release plate in the embodiment is rotated; FIG. 12 is an enlarged sectional view showing the state in which the piece in the third embodiment is disengaged from the engagement groove; FIG. 13 is a sectional view showing the fourth embodiment. Figure, 14th
The figure is a perspective view showing the bottom of the outer drum in the fourth embodiment, FIG. 15 is a sectional view showing the fifth embodiment,
FIG. 16 is an exploded perspective view showing members disposed within the small diameter portion in the fifth embodiment. 10... Webbing drive device, 38... Worm wheel, 44... Outer drum, 46... Clutch portion, 48... Electromagnet, 50... Lever, 7
0... Webbing drive device, 72... Worm wheel, 74... Arm portion, 78... Engaging claw, 81...
...Engagement groove, 82...Electromagnet, 90...Webbing drive device, 92...Worm wheel, 94...
Engagement groove, 96... recess, 98... piece, 102
...Release plate, 114...Solenoid, 12
0... Webbing drive device, 122... Worm wheel, 124... Solenoid, 130... Recess, 170... Webbing drive device, 172...
Worm wheel, 174...Electromagnet, 176...
...clutch ring, 178... recess, 184...
recess.

Claims (1)

[Scope of Claims] 1. A guide rail disposed on the roof side of a vehicle along the longitudinal direction of the vehicle, and a slider movably disposed within the guide rail and having one end of occupant restraint webbing latched. and an adjuster arranged near the end of the guide rail on the rear side of the vehicle and capable of locking the slider and adjusting the locking position in the vehicle height direction. , the rope connected to the slider is wound up and unwound by a drum connected to the rotary drive shaft of the motor, thereby moving the webbing in the longitudinal direction of the vehicle along the guide rail and automatically attaching it to the occupant. and a webbing drive device for releasing the webbing, which is provided between the rotary drive shaft and the drum, and connects the rotary drive shaft and the drum when the slider moves along the guide rail, transmits the rotation of the drum to the drum, and operates in response to a signal issued when adjusting the height of the adjuster with the slider locked to the adjuster, and releases the connection between the rotary drive shaft and the drum. A webbing drive device comprising a clutch that interrupts transmission of rotational force between the rotational drive shaft and the drum. 2. The clutch is arranged between an electromagnet fixed to the drum, an engagement protrusion formed on the rotational drive shaft, and the electromagnet and the engagement protrusion, and is engaged with or disengaged from the engagement protrusion by the magnetic force of the electromagnet. Webbing drive device according to claim 1, characterized in that it comprises a lever that can be moved. 3. The clutch includes an electromagnet disposed on the axial center side of the rotational drive shaft, an engagement groove formed in the drum,
Claim 1, further comprising: an engaging pawl formed on the rotational drive shaft, which is elastically deformed and moved in the axial direction by the magnetic force of the electromagnet, and is capable of engaging with or disengaging from the engaging groove. The webbing drive device according to item 1. 4. The clutch has a recess formed in the drum, an engagement groove formed in the rotational drive shaft, a piece arranged in the recess that can be inserted into or removed from the engagement groove, and a piece that can be engaged with the piece. The webbing drive device according to claim 1, characterized in that the webbing drive device comprises a release plate that presses the disposed piece to separate it from the engagement groove, and a solenoid that rotates the release plate when energized. . 5. The clutch includes a recess formed in the drum, and a solenoid that is fixed to the rotational drive shaft and can be inserted into or removed from the recess by being energized.
The webbing drive device described in Section 1. 6. The clutch is arranged between an electromagnet fixed to the rotary drive shaft, a recess formed in the drum, and the rotary drive shaft and the drum, and is moved in the axial direction of the rotary drive shaft by the magnetic force of the electromagnet. 2. The webbing drive device according to claim 1, further comprising a clutch ring having a convex portion that can be engaged with the concave portion.