JPH10244905A - Webbing take-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take out the whole quantity of webbing so that when the ELR (Emergency Locking Retractor) is changed over to the ALR(Automatic Locking Retractor), the webbing is not remained as a surplus winding in the take-up shaft, even if the webbing take-up device is provided with a function to change over the taking-out of the webbing in the neighborhood of full taking-out from the ELR to the ALR, and also to simplify the structure. SOLUTION: When the webbing is brought to a full taking-out condition, a cam 32 engages the ALR pawl 22 with the ratchet tooth 20 of a lock ring 18 to prevent the webbing taking-out rotation of a webbing take-up shaft; while, the taking-out of the whole quantity of webbing can be enabled by setting the ALR pawl 22 in such a condition that it is not possible to be engaged with the lock ring 18 by means of the interlocking inhibiting part 62 of the cam member 32 at least from a prescribed condition before the whole quantity of webbing is taken out from the take-up shaft up to the whole quantity take-up and further to shift to the take-up action.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a webbing take-up device which is used in a seat belt device and which can always keep the webbing from being pulled out after a predetermined amount of webbing has been drawn.

[0002]

2. Description of the Related Art A webbing take-up device provided in a vehicle has a built-in lock mechanism for preventing rotation of the webbing in the pull-out direction when necessary.

A webbing take-up device having a lock mechanism of this type can normally take up and pull out the webbing. When the vehicle suddenly decelerates, the speed is sensed by an acceleration sensor, and the lock mechanism instantaneously operates. A so-called ELR (Emergency Locking Retractor) that prevents rotation of the webbing in the pulling-out direction and a lock mechanism that operates when the surplus length is wound up after the occupant wears the webbing, and prevents further pulling out. There is a so-called ALR (Automatic Locking Retractor) in which the webbing is prevented from being pulled out when the webbing is almost completely wound into the winding device, and the webbing can be pulled out again.

[0004] Here, a webbing take-up device provided with these ELR and ALR has already been devised by the present applicant (for example, see Japanese Utility Model Application Laid-Open No. 3-11059).

In the webbing take-up device disclosed in this publication, a lock wheel that rotates following the take-up shaft and is prevented from rotating is operated by a lock means to prevent the take-up shaft from rotating in the webbing pull-out direction. And an ELR lever which is normally positioned at a distance from the lock wheel but engages the lock wheel to prevent rotation when the vehicle suddenly decelerates, and an engagement position and lock which engage the lock wheel. An ALR lever that is selectively held at a separated position separated from the wheel. Further, a release gear for switching the position of the ALR lever is disposed coaxially with the winding shaft.

This release gear is decelerated when the winding shaft rotates and rotates in the opposite direction. When the webbing is almost completely pulled out, the ALR lever is switched from the separated position to the engaged position. Further, the webbing is set to a substantially full-winding state so that the ALR lever is switched from the engaged position to the separated position.

By the way, in the above-described webbing take-up device in which ELR and ALR can be switched as required, in the state where the entire webbing is completely pulled out, the ALR is moved from the ELR to the ALR.
The configuration is such that the switching from the ELR to the ALR is performed at a timing with some margin. In other words, the state immediately before the webbing is brought into the fully drawn state (20 to 10 from the full drawn state).
The engagement relationship between the release gear and the ALR lever is set so that the ELR can be switched from the ALR to the ALR at a position about 0 mm closer to the ALR lever. Therefore, the usable length of the webbing varies, and the portion not always used (portion from the switching position to the webbing locking end to the winding shaft).
Will remain as extra winding on the winding shaft. For this reason,
Since the cutting length of the webbing is set in anticipation of the portion remaining as the extra winding, the cutting length of the webbing becomes longer, which causes an increase in cost.

Further, if a webbing take-up device is designed to eliminate a portion remaining as an extra winding of the webbing, a plurality of intermittent gears which are complicatedly formed with high precision for speed reduction may be used. The cost is high.

In view of the above facts, the present invention provides a webbing take-up device which has a simple structure and can be easily manufactured, in which the entire webbing can be pulled out and a portion remaining as an extra winding can be eliminated even if the device has the function of ALR. That is the purpose.

[0010]

According to a first aspect of the present invention, there is provided a webbing take-up device comprising: a take-up shaft for taking up webbing for restraining an occupant; a lock means for stopping rotation of the take-up shaft in a webbing pull-out direction; The lock means is urged to move to a position where the lock means is actuated and engages with the lock means, or is moved against the urging force to a position where the operation of the lock means is released to engage with the lock means. A detachably attached
An LR pawl, a first drive gear that rotates together with the winding shaft, a reduction mechanism that operates intermittently with a reduction gear that meshes with the first drive gear, and a rotation mechanism that rotates in conjunction with the reduction mechanism; A stopper having a guide surface portion in a part thereof, a cam member provided with an interlocking stopper, and a disk control provided with a stopper operating portion while being rotated by the interlocking stopper of the cam member. Wherein the ALR is used during normal use until the webbing wound around the winding shaft is pulled out to near its entirety.
In order to hold the pawl at the position where the operation of the locking means is released, the disc control restraining operation portion is positioned, and the cam member interlocking with the winding shaft controls the disc control when the webbing is completely pulled out. Pivotally move the ALR pawl from the stopping operation section onto the interlocking stopping section, hold the ALR pawl at a position where the locking means is released, and wind up the webbing from the fully drawn state. When started, the cam member interlocking with the winding shaft is rotated, the ALR pawl is released from the interlocking stop, and the lock unit is operated to switch to the ALR state. When the webbing is wound by a predetermined amount, the rotating cam member rotates the disc control. Wherein the stop operation section is adapted to set a state to hold the position for releasing the operation of the locking means the ALR pawl.

With the above-described configuration, the ALR
Since the pawl is released from the locking means by the interlocking stopper of the cam member until the full amount of the webbing is pulled out from the state before the full amount of the webbing is pulled out, the winding shaft is not stopped from rotating in the pulling direction. The webbing can be pulled out over the entire length.

According to a second aspect of the present invention, in the webbing take-up device according to the first aspect, the sensor pawl of the acceleration sensor device cannot be engaged with the locking means during a period from a state in which the webbing is fully wound to a state in which the webbing is pulled out by a predetermined small amount. Thus, the present invention is characterized in that the cam member is configured so as to be held by a stopping portion.

With the above construction, since the sensor pawl is released from the locking means by the stopper of the cam member from the state before the full amount of the webbing is pulled out to the time when the full amount is pulled out, the webbing is pulled out. It is possible to prevent a so-called end lock state in which the lock means cannot be released.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Schematic Configuration of Winding Apparatus) FIGS. 1 and 2 show a cross section of a main part of a webbing winding apparatus according to an embodiment of the present invention, and FIGS. It is shown.

As shown in FIG. 5, in this webbing take-up device, a main body frame 10 is fixed to a vehicle body by mounting bolts (not shown). The body frame 10 has a pair of legs 12A and 12B extending from both sides in parallel with each other. The sensor cover 16 is attached to the leg 12A on the near side in FIG.

A winding shaft 14 is supported by these frame legs 12A and 12B. Further, a through-hole (not shown) is formed in the center of the winding shaft 14 so as to penetrate in the radial direction, and one end of an occupant restraining webbing (not shown) is locked in the through-hole. I have. The arrow A in the drawing indicates the rotation direction of the winding shaft 14 due to the webbing being pulled out.

One end of a spring (not shown) is locked at the rear end of the winding shaft 14 (in the direction of the arrow RE in FIG. 5). Since the webbing is urged in the direction (the direction opposite to the direction of arrow A), the normal webbing is wound around the winding shaft 14 in the direction opposite to the direction of arrow A. Then, although not shown, the occupant can be put on the webbing by pulling out the webbing and engaging the tongue plate attached to the end of the webbing with the buckle device attached to the vehicle body. (Structure of Locking Means) A part of the winding shaft 14 is provided with a generally used locking means. As shown in FIGS. 1 and 8, a lock wheel 18 is mounted on the take-up shaft 14 in order to constitute the lock means. An external ratchet wheel 20 is formed on the outer periphery of the lock wheel 18. The external tooth ratchet wheel 20 includes an ALR pawl 22 described later for causing the locking means to perform a webbing pull-out stopping operation, and an acceleration sensor device 120.
And the sensor pawls 24 can be disengaged. When the pawls stop rotating, relative rotation with respect to the winding shaft 14 occurs.

In this locking means, in the ALR operation state, when the ALR pawl 22 faces the external ratchet wheel 20 so as to be able to lock it, or when a large acceleration is applied to the vehicle, the sensor pawl 24 moves the external ratchet wheel 2.
When the webbing is pulled in the pulling-out direction when the webbing is set to be locked at 0, the winding shaft 14 starts to rotate and follows the winding shaft 14 via a biasing means such as a spring. The lock wheel 18 also tries to rotate. However, at this time, when the ALR pawl 22 or the sensor pawl 24 meshes with the external tooth ratchet wheel 20 to stop the rotation of the lock wheel 18, the winding shaft 14
Only rotate a small amount. Then, in this locking means, the relative rotation operation of the lock wheel 18 and the winding shaft 14 causes
The claw portion of the lock means attached to the take-up shaft 14 which constitutes a part of the not-shown lock means meshes with an internal tooth ratchet wheel which is also formed integrally with the leg 12A which is not shown, and The webbing stops rotation in the pulling-out direction, and is configured so that the webbing is not pulled out any more. (Arrangement of ALR / ELR switching mechanism) As can be understood by comparing and comparing the drawings in FIGS. 1 to 7, in this webbing take-up device, the take-up device extending from the leg portion 12 </ b> A of the frame 10 of the main body of the webbing take-up device. Locking wheel 18 for locking means on shaft 14
A switching mechanism for switching between ALR and ELR is mounted on the outer portion. The switching mechanism between ALR and ELR is provided between the sensor cover 16 and the sensor plate 26 by the holder 2.
8, a disk control 30, a cam member 32, a ratchet member 34, and a rotor 36 are mounted. Further, the sensor cover 16 and the sensor plate 26
Between the ALR pawl 22 and the acceleration sensor device 12
0 is arranged. (Schematic Configuration of Sensor Cover) As shown in FIGS. 1, 2 and 5, the sensor cover 16 is fixed so as to cover a locking means having a locking ring 18 on the outer surface of one leg 12A. The winding shaft 14 extending from the leg 12A is formed in a circular cover shape with the extension shaft portion 14A at the center. As shown in FIG. 5, the sensor cover 16 is integrally formed with an ALR accommodating portion 38 for the ALR pawl 22 and a storage portion 40 for the acceleration sensor device 120 at two predetermined positions. A through hole 42 is formed at the center of the circular cover-shaped portion of the sensor cover 16, and the extension shaft 1 of the winding shaft 14 is formed through the through hole 42.
4A is extended. The rotor 36 is inserted into the extension shaft portion 14A. (Structure of Rotor) That is, as shown in FIGS. 4 and 7, the rotor 36 has a cylindrical shaft portion 44, and a hole The rotor 36 is inserted and fixed to the extension shaft portion 14A so that the extension shaft portion 14A is inserted and rotated integrally with the extension shaft portion 14A.

The rotor 36 is provided at the front end (in the direction of arrow FR) of the shaft portion 44 thereof with a first drive gear 47 which is an intermittent gear having two continuous teeth as clearly shown in FIG. ing. The rotor 36 is provided with a disk-shaped support plate portion 48 at an intermediate portion of the shaft portion 44.
On the front side surface of the support plate portion 48, an internal ratchet tooth portion 50 is formed in a three-dimensional manner so as to rise from the side surface. Further, a U-shaped groove (FIG. 7) is formed at each of four central angles on the circumference of a circle concentric with the shaft portion 44 of the support plate portion 48, thereby forming a substantially L-shaped groove as shown in FIG. An elastic support member 52 is formed integrally with a tongue-shaped tongue having a hook-like bent end. Further, a cylindrical shaft cylinder 54 is integrally formed on the support plate portion 48 at a position between the elastic support member 52 and the shaft portion 44 so as to be coaxial with the shaft portion 44. (Structure of Ratchet Member) A ratchet member 34 is mounted on the rotor 36 so as to be rotatable in one predetermined direction (webbing pull-out direction). The ratchet member 34 is formed in an annular shape, and a circular opening at the center thereof is formed as a supporting peripheral portion 56 which is rotatably supported by the elastic support member 52 (see FIG. 1). In addition, as shown in FIGS. 4 and 7, at two predetermined positions on the side surface of the ratchet member 34, the side surface portion is cut out in a substantially U-shape or an inverted U-shape to be curved and elongated along the circumferential direction. A cantilevered locking piece 58 is formed as a tongue piece. A bearing peripheral portion 56 is provided on the elastic support 52 of the rotor 36.
The ratchet member 34 supported by the latching member 58 has an end protruding portion of the locking piece 58 elastically pressed against the internal ratchet tooth portion 50, and the ratchet member 34 is attached to the rotor 36 by an arrow A in FIG.
When rotating in the direction (webbing pulling-out direction), the locking piece 58 slides on the internal ratchet teeth 50 and is elastically deformed to be freely rotatable. When trying to rotate in the direction opposite to the arrow A, the locking piece 58 is engaged with the internal ratchet teeth 50, and the rotation in the direction opposite to the arrow A is stopped.

The ratchet member 34 is formed on its outer periphery with a ratchet tooth portion 60 for facilitating the releasing operation of the sensor pawl 24 engaged with the external tooth ratchet wheel 20 of the lock wheel 18. (Configuration of Cam Member) The cam member 32 is mounted on the rotor 36 to which the ratchet member 34 is mounted as described above. As shown in FIG. 4 and FIG.
The whole is formed in a substantially disk shape, and a shaft cylinder portion 61 is integrally provided at a central portion thereof so as to protrude toward the rotor 36. As shown in FIG. 1, the shaft cylinder portion 61 is slidably fitted with the shaft cylinder 54 of the rotor 36 in the shaft cylinder hole, so that the rotor 36 and the cam member 32 are relatively freely rotatable. It is pivoted.

The outer periphery of the cam member 32 has an interlocking stop 6
2 and the stopping portion 64 are provided integrally. The interlocking stop portion 62 has a substantially trapezoidal plate shape, a part of which is a cam member 32.
The cam member 32 is formed integrally with the cam member 32 so as to be one step higher from the side surface of the cam member 32 on the disk control 30 side (the direction of arrow FR). Further interlocking stop part 6
In FIG. 2, each side portion of the cam member 32 along the diametrical direction corresponds to a part of the disc control 30 and serves as interlocking portions 62A and 62B for interlocking the disc control 30.

The stopping portion 64 is provided on the outer peripheral portion of the cam member 32.
A part of a small-diameter cylindrical peripheral surface is formed over a range of a predetermined central angle originating from the interlocking stopper 62, and the interlocking stopper 6 is formed.
Similarly to 2, the cam member 32 is formed to have a larger diameter than the outer diameter. A guide surface 66 that is inclined with respect to the connecting direction of the cam member 32 is formed at an end of the stop 64 opposite to the interlocking stop 62, and the guide surface 66 extends toward the tip of the cam member 32. It is inclined toward the center of.

On the side surface of the cam member 32 corresponding to the disc control 30, there is formed a ring-shaped pedestal 70 which is raised one step around the through hole of the shaft cylinder part 61, and is further raised further thereon. Thus, a cam rotation gear 68, which is an external gear, is integrally formed. Further, the cam member 32 is integrally formed with a cam rotation gear 68 and a rotation support portion 72 having a rectangular cross section and a ring shape around the pedestal 70. (Structure of Disc Control) The disc control 30 is rotatably supported by the cam member 32 at a rotation support portion 72 thereof. This disk control 30
Is formed in an annular shape with a round shaft opening 74 formed in the center of the disk. Then, as shown in FIG.
In a state where the rotary support portion 72 is axially inserted into the round shaft opening 74,
Both are rotatable relative to each other while the disc control 30 is slidably guided on the side surface of the cam member 32.

A stop operation section 76 for the ALR pawl 22 is formed integrally with the outer periphery of the disc cotton roll 30. The stopping operation portion 76 forms an arc-shaped extending portion by radially extending the disc control 30 over a range of a predetermined central angle, and a free end around the arc-shaped extending portion is shown in FIGS. 7 and projecting toward the cam member 32 in a hook shape in cross section, the projection forming portion is a restricting rib portion 77 in which the thickness of the outer peripheral portion of the restricting operation portion 76 becomes a predetermined width. ing. As a result, the portion of the disc control 30 where the stopping operation portion 76 is not formed is the small diameter portion 30A.

As shown in FIG. 7, a contact end 76A, which is one end of the stopping operation section 76, is formed in an L-shape so as to contact the interlocking section 62A of the interlocking stopping section 62. In addition, the other end of the stopping operation section 76 is provided with an interlocking section 62.
B along the diametrical direction of the disc control 30 so as to abut against the stop rib portion 78 along the diameter direction of the disc control 30.
Is provided. In addition, on this other end,
From the outer periphery of the disc control 30 to the top of the contact rib 78, a guide oblique side 80 is formed in which the plate surface of the disc control 30 is formed oblique to the radial line.

The leading end of the guide hypotenuse 80 in the radial direction has a diameter larger than that of the stop operation part 76, and a continuous line with the stop operation part 76 is formed as a gentle slope 80A.
When rotated counterclockwise as shown in FIG. 13, the driven table section 116 can easily move over the tip of the guide hypotenuse 80 and move to the interlocking stop section 62.

In the disk control 30 constructed as described above, the abutting end portion 76A of the disk control 30 is stopped by hitting the interlocking portion 62A while the disc control 30 is mounted on the cam member 32. The cam member 32 is rotatable relative to the cam member 32 in a range up to the stop at 62B. (Structure of Inner Part of Sensor Cover) As shown in FIGS. 1 and 6, a sensor plate 26 which is assembled to the sensor cover 16 to constitute a housing is provided with a disk control 3
0, cam member 32, ratchet member 34, and rotor 3
A main case portion 26A having a substantially front circular shape for covering a portion 6 (FIG. 3), and a holder case portion 26B for covering a holder 28 formed in a substantially small circular shape in an eccentric part thereof; An ALR pawl cover 26C for mounting and covering the ALR pawl 22, and the acceleration sensor device 1.
An acceleration sensor cover 26D that covers 20 is integrally formed.

As shown in FIG. 1, FIG. 2, and FIG. 6, an engaging claw portion 82 for the cam member 32 and large and small sliding guide ribs 84, 86 are provided at the inner central portion of the main case portion 26A. It is protruding. The interlocking claw 82 is provided with a plurality of small protruding pieces arranged in a substantially semicircular shape and erected.
At the front end of 2, a warp claw 88 having a substantially side surface triangular shape is formed. The warp claw portion 88 is engaged with the back side (the ratchet member 34 side) of the peripheral opening 68A extending into the hole of the shaft cylinder portion 61 opened at the center of the cam rotation gear 68 of the cam member 32, and acts as a stopper.

The small sliding guide rib 84 provided on the inner surface of the main case portion 26A is formed in a substantially semi-circular shape around the engaging claw portion 82, and the side surface of the cam member 32 in the assembled state shown in FIG. To limit the axial movement amount of the cam member 32.

The large sliding guide rib 86 provided on the inner surface of the main case portion 26A is arranged in a semicircular shape around the small sliding guide rib 84, and has a larger diameter and a higher height than the small sliding guide rib 84. In the assembled state shown in FIG. 1, the disk control 30 slides on the side surface of the disk control 30 to limit the axial movement of the disk control 30. (Structure of Holder) As can be understood from FIGS. 1, 2, and 6, the holder case portion 26B of the sensor plate 26 is
The sensor plate 26 is formed so as to protrude outward from the main case portion 26 </ b> A (opposite to the sensor cover 16, that is, in the direction of the arrow FR) in a small circle shape by one step. At the center of the holder case portion 26B, there is provided a support member 90 protruding toward the inner surface side (the sensor cover 16 side). This support member 90 is formed by connecting three prisms to the
It is arranged at the division position and formed as a rotation bearing shaft,
A claw portion 92 protruding outward in a substantially triangular shape is formed at each end. The holder 28 is rotatably supported by the support member 90. A cylindrical shaft hole 94 for forming a shaft hole is integrally provided at the center of the holder 28. As shown in FIG. 1, a support member 90 is passed through the shaft hole 94, and the claw portion 92 is engaged with a counterbore portion of the shaft hole 94 facing the disk control 30, so that the holder can be attached to the sensor plate 26. 2
8 is freely rotatable.

As shown in FIGS. 1 to 3 and FIG. 6, the holder 28 has a first driving gear 4
A reduction gear 96 which is an outer peripheral gear having a half tooth width is provided at every other tooth of the intermittent gear mechanism meshing with the gear 7. Further, an interlocking gear 98 that is a ring-shaped external gear that surrounds the shaft hole 94 is provided on a plane portion of the holder 28 on the disk control 30 side (arrow RE side). The interlocking gear 98 is in the assembled state of FIG.
With the cam rotation gear 68. (Configuration of ALR pawl) As shown in FIGS. 1, 3, and 6, the ALR pawl cover 2 of the sensor plate 26 is provided.
6C is formed at a position near one side below the main case portion 26A in each figure, and a round bar-shaped shaft pin 100 is erected on a part thereof. This shaft pin 10
0, a small cylindrical fitting protrusion 102 is integrally formed. The fitting protrusion 102 is provided at a corresponding hole of the sensor cover 16 shown in FIG. 104
Is fitted to.

As can be seen from FIGS. 3 and 6, the ALR pawl 22 has a shaft pin 1 inserted into a shaft hole 106 which is a round through hole.
00 is axially inserted and is supported by the ALR pawl cover 26C. The ALR pawl 22 has a cylindrical shaft portion 110 provided with a shaft hole 106 at a base end thereof, and a claw portion 108 for engaging with the external tooth ratchet wheel 20 of the lock wheel 18 at a distal end thereof. It protrudes integrally. A rectangular notch 114 is provided between the bearing portion 110 of the ALR pawl 22 and the claw portion 108, and the coil portion of the torsion coil spring 112 is inserted and attached to the outer peripheral portion of the bearing portion 110. With the urging force of the torsion coil spring 112, the ALR pawl 22
8 is urged in a direction to engage the external ratchet wheel 20 of the lock wheel 18.

On the side of the ALR pawl 22 opposite to the side on which the notch 114 is provided, a small base-like driven base 11 is provided.
6 are provided integrally. When the interlocking stop portion 62 of the cam member 32 or the stop operation portion 76 of the disc control 30 slides on the driven base 116, the ALR pawl 2
2 is configured to operate in a direction in which the claw portion 108 is separated from the outer peripheral ratchet wheel 20 of the lock wheel 18. That is, when the cam member 32 rotates clockwise from the state shown in FIG. 11, the interlocking stopper 62 presses the driven base 116 as shown in FIG. 12 to separate the ALR pawl 22 from the external tooth ratchet wheel 20. When the number 76 corresponds to the ALR pawl 22, as shown in FIGS.
The pawl 108 of the R pawl 22 is connected to the external ratchet wheel 20.
Away from (Structure of the acceleration sensor device) As can be understood in consideration of FIGS. 3, 5, and 6, the acceleration sensor cover portion 26D of the sensor plate 26 has a main case portion 2
The ALR pawl cover 26C is disposed on the lower side of 6A at a position opposite to the ALR pawl cover 26C. This acceleration sensor cover 2
6D, the sensor plate 26 is assembled to the sensor cover 16 to form a housing portion for the acceleration sensor device 120. This acceleration sensor device 120 is generally used. As shown in FIG. 3, a metal sphere 126 is formed in a receiving recess 124 which forms a part of a large-diameter spherical surface provided on a pedestal 122 fixed to a sensor plate 26. Is mounted, and the sensor pawl 24 supported by the column 128 of the base 122 is mounted.
Is mounted on the sphere 126. Then, when the sphere 126 moves so as to climb inside the receiving recess 124 by receiving a vehicle acceleration of a predetermined value or more, the sensor pawl 24 engages the claw 132 with the external tooth ratchet wheel 20 of the lock wheel 18. Be moved. (Gear Reduction Mechanism for Cam Member) Next, a gear reduction mechanism used for the above-described switching mechanism between ALR and ELR will be described with reference to FIG. In this gear reduction mechanism,
With respect to the first drive gear 47 which rotates integrally with the winding shaft 14,
The reduction gear 96 is engaged. This first drive gear 47
And the reduction gear 96 constitute a reduction mechanism by intermittent motion, and the rotation of the reduction gear 96
Performs an intermittent operation of continuously rotating two teeth and then stopping.

The intermittent operation of the reduction gear 96 is transmitted to a cam rotation gear 68 meshing therewith via an interlocking gear 98 that rotates integrally with the reduction gear 96, and is integrated with the cam rotation gear 68. The cam member 32 is rotated. (Switching operation between ALR and ELR) Next, the operation of the switching mechanism between ALR and ELR of the webbing take-up device in the present embodiment will be described.

First, when the webbing (not shown) is wound up to near its full length by the rotation of the winding shaft 14 of the webbing winding device in the direction opposite to the direction of arrow A, the state shown in FIG. 17 is obtained. In other words, the driven base 116 of the ALR pawl 22 rides on the outer peripheral surface of the stop operation unit 76 of the disc control 30 near the contact rib 78,
The claw portion 108 of the ALR pawl 22 is separated from the external ratchet wheel 20 of the lock wheel 18 to disable the engagement, and the operation of the ALR pawl 22 does not restrict the operation of the webbing in the pulling-out direction. It has been. Further, in the state of FIG.
Is located at a position off the guide surface 66 of the stopping portion 64 of the cam member 32 (since the guide surface 66 is stopped at a position distant from the claw 132 in the circumferential direction), the vehicle acceleration In response, the acceleration sensor device 120 operates to push up the sensor pawl 24 to the position indicated by the solid line in FIG. 9 and lock the webbing when the webbing is about to be pulled out, so that the webbing pulling-out operation can be stopped. ing. When the webbing is suddenly wound by the winding force of the winding shaft, the locking means is inadvertently activated by the relative rotation of the winding shaft 14 and the lock wheel 18 in the fully wound state, and the webbing is prevented from being pulled out. Even if an end lock state occurs, if a small amount of webbing is wound around the take-up shaft 14, the lock state can be released, so that the end lock does not continue.

Next, in a state where the webbing is pulled out by a required amount and the occupant seated on the seat is wound around the seat belt, the state is as shown in FIG. 10 through FIG.

That is, when the operation of pulling out the webbing from the fully wound state shown in FIG. 17 is started, the first drive gear 47 rotates in the direction of arrow B in FIG. Then, the reduction gear 94 meshing with the first drive gear 47 becomes
The gear intermittently rotates in the direction of arrow C in the figure, and the interlocking gear 98 integral with the reduction gear 94 also rotates in the direction of arrow C. The cam rotation gear 68 meshing with the interlocking gear 98 rotates in the direction of arrow B. Therefore, the cam member 32 integral with the cam rotation gear 68 is left with the arrow B except for the disk control 30.
Rotate in the direction. 9 to 17, in order to easily understand the rotating operation of the reduction gear 96, one tooth of the gear is a mark tooth 96A painted black.

In the above-described state, the cam member 32 rotating at a low speed after deceleration moves the interlocking stop portion 62 between the small diameter portion 30A of the disc control 30 and the vicinity of the contact end portion 76A toward the guide oblique side 80. At this time, a force to slightly rotate the cam member 32 due to friction with the cam member 32 is applied to the disc control 30. However, the ALR pawl 22 is formed between the raised protrusion at the contact end 76A and the gentle slope 80A. And the rotation of the cam member 32 due to friction is restricted.
In the case of 0, the operation forcibly operated by the interlocking stopper 62 of the cam member 32 is performed. Therefore, at this time, the ALR pawl 22 remains in a state in which the driven base 116 is mounted on the stop operation unit 76 of the disk control 30 and cannot be engaged with the external tooth ratchet wheel 20. At this time, the sensor pawl 24 maintains a state in which it can be engaged with the external tooth ratchet wheel 20. In the state of FIG. 10, the occupant wears the webbing by buckle engagement. Although the webbing is taken up and pulled out due to a change in the operating position, the cam member 32
When the claw 132 engages with the external ratchet wheel 20, the locking means stops the webbing withdrawal rotation of the winding shaft 14, and the occupant is restrained. When the occupant releases the mounting of the webbing, the state returns to the state shown in FIG.

Next, even if the take-up shaft rotates in a certain range in the webbing pull-out direction or the take-up direction due to a change in the driving posture of the occupant or a difference in the occupant's physique from the state of FIG. The stopping part 62 is the guide hypotenuse 80
Therefore, the state in which the disc control 30 holds the ALR pawl 22 does not change. When the webbing is further pulled out beyond the mounting range of this webbing,
The reduction gear 96 of the holder 28 rotates about one third from the state shown in FIG. 10 to reach the position immediately before switching shown in FIG. In the state shown in FIG. 11, the interlocking portion 62 </ b> B, which is the tip of the interlocking stop portion 62 of the cam member 32 that has turned in the direction of arrow B in conjunction with the reduction gear 96, is connected to the contact rib portion 7 of the disc control 30.
Contact 8 The other states are the same as the states in FIG. 10 described above.

Next, when the webbing is further pulled out from the state shown in FIG. 11, the cam member 3 is moved by the gear mechanism described above.
2 further rotates in the direction of arrow B while pushing the disk control 30 forward, and reaches the switching transition state shown in FIG.

In the state shown in FIG. 12, the ALR pawl 22
Is moved from the stop operation unit 76 to the gentle slope 80A.
And the ALR pawl 22 is maintained in a state in which the ALR pawl 22 cannot be engaged with the external tooth ratchet wheel 20. Note that the sensor pawl 24 maintains a state in which it can be engaged with the external tooth ratchet wheel 20.

Next, when the entire webbing wound around the winding shaft 14 is pulled out from the state shown in FIG. 12 as shown in FIG. 13, the cam member 32 is further rotated in the direction of arrow B by a gear mechanism, and The base 116 is the interlocking section 62 of the interlocking stop 62
The player has reached the fully drawn state shown in FIG. In the fully pulled-out state shown in FIG. 13, the other states are the same as those in FIG. Note that FIG.
In the state of ALR pawl 22 is external tooth ratchet wheel 2
Since it is not possible to engage with 0, the entire amount can be drawn out without leaving the webbing. For this reason, it is possible to prevent a small amount of webbing from being unwound around the winding shaft 14 by the webbing full-drawing operation, and to always make the webbing withdrawal length a constant length corresponding to the entire length of the webbing.

When assembling and manufacturing the webbing take-up device according to the present embodiment, the state shown in FIG. 13 is set as a state in which an initial state at the time of assembly is set, and is used as one reference for assembling work.

Next, when the webbing is rolled in a small amount from the state shown in FIG. 13, the state reaches the ALR switching state shown in FIG. That is, the first operation is performed by the webbing winding operation.
The drive gear 47 rotates in the direction of the arrow D, and the cam member 32 also rotates in the direction of the arrow D by the above-described gear mechanism interlocked with the drive gear 47 and separates from the disk control 30. By this operation, the driven base 116 of the ALR pawl 22
The ALR pawl 22 is disengaged from the interlocking stop 62 of the cam member 32, and the pawl 108 is engaged with the external ratchet wheel 20 of the lock wheel 18 by the biasing force of the torsion coil spring 112.

In the state of ALR shown in FIG. 14, the webbing can be rolled in and cannot be pulled out. That is, during the webbing winding operation, since the lock wheel 18 rotates in the direction of arrow D, the external ratchet wheel 20 rotates while sliding the claw 108 of the ALR pawl 22, so that the webbing winding operation is performed. Is possible.

However, when trying to pull out the webbing in the state shown in FIG. 14, the claw 108 of the ALR pawl 22 engages with the external tooth ratchet wheel 20 and the arrow D of the lock wheel 18 moves.
And the rotation in the opposite direction is stopped. Then, a relative rotation operation occurs between the lock wheel 18 and the winding shaft 14, the lock means operates, and the operation of pulling out the webbing is stopped. In addition,
Even in this state, the above-described operation of operating the lock unit by operating the acceleration sensor device 120 to stop the webbing from being pulled out is executed as it is.

Next, when the webbing is sufficiently entangled beyond the normal occupant mounting range from the use state of the ALR shown in FIG. 14, the cam member 32 is moved by an arrow D by the gear mechanism.
1 in which the interlocking portion 62A of the interlocking stop portion 62 abuts on the abutting end portion 76A of the disc control 30.
The ALR release start state shown in FIG. Note that FIG.
In the state shown in FIG. 7, the ALR pawl 22 and the sensor pawl 2
4 is in a state of acting similarly to FIG. 14 described above.

Next, when the webbing is further rolled in from the state of FIG. 15, the cam member 32 is further rotated in the direction of arrow D, and the disk control 30 is pushed and turned in the direction of arrow D. Then, the guide hypotenuse 80 of the disc control 30 scoops up the driven base 116 and the stop operation part 7
6 on which the claw 108 of the ALR pawl 22 cannot be engaged with the external tooth ratchet wheel 20 of the lock wheel 18.
Hold in the release completed state. The AL shown in FIG.
In the R release completed state, the sensor pawl 24 is set in a state where it can be engaged with the external tooth ratchet wheel 20 to operate the locking means and prevent the webbing from being pulled out.

Next, when the webbing is further involved from the ALR release completed state shown in FIG.
Is further rotated in the direction of arrow D together with the disk control 30, and its guide surface 66 scoops up the claw 132 of the sensor pawl 24, and this claw 132 is
In this state, the end lock preventing operation shown in FIG. With this,
In the operation state of end lock prevention shown in FIG.
The pawl portion 108 of the pawl 22 is also disabled from engagement with the external tooth ratchet wheel 20 by the stopping operation portion 76. Therefore, in the state where the webbing is fully wound around, the ALR
Since the pawl 22 and the sensor pawl 24 are both incapable of engaging with the external ratchet wheel 20, they do not operate the locking means to prevent the webbing withdrawal operation. For this reason, when the webbing is suddenly fully wound, the lock wheel 18 is moved by the inertia force to the winding shaft 14.
The end lock state in which the webbing cannot be pulled out thereafter because the webbing is pulled out by the locking means and the webbing is stopped by the locking means can be avoided.

When the webbing starts to be pulled out from the state shown in FIG. 17, the state returns to the state shown in FIG. 9, and the above-described operation is repeated.

Further, in this embodiment, since only the reduction mechanism using one set of intermittent gears is used as the gear mechanism for the switching operation between ALR and ELR, the gear parts are compared with the case where a plurality of intermittent gears are used. Can be easily and inexpensively manufactured and assembled.

[0052]

As described above, the webbing take-up device according to the present invention allows the entire webbing to be drawn out even if it has an ALR function, so that the webbing does not remain as an extra winding on the winding shaft. It has an excellent effect that a webbing take-up device having a simple structure and easy to manufacture can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional end view of a main part of an ALR / ELR switching mechanism of a webbing take-up device according to an embodiment of the present invention. However, the winding shaft 14 is not shown.

FIG. 2 is an exploded longitudinal sectional view of a portion corresponding to FIG. 1 of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a main part of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a main part of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

FIG. 5 is an exploded perspective view showing a main part of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

FIG. 6 is an exploded perspective view showing a main part of a portion corresponding to FIG. 3 of the ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention, viewed from the other side.

FIG. 7 is an exploded perspective view showing a main part of a portion corresponding to FIG. 4 of the ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention, viewed from the other side.

FIG. 8 is a schematic structural explanatory view of a gear mechanism part of a main part of an ALR / ELR switching mechanism part of the webbing take-up device according to the embodiment of the present invention.

FIG. 9 is a partial front view showing a partial cross section of a state in which the webbing of the ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention has been wound up to near its full length.

FIG. 10 is a partial front view showing a normal use state of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention in a partial cross section.

FIG. 11 is a partial cross-sectional front view showing a state immediately before switching of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention;

FIG. 12 is a partial cross-sectional plan view showing a state immediately before switching of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention in a partial cross section.

FIG. 13 is a plan view showing a main part of the webbing take-up device according to the embodiment of the present invention, in which the ALR / ELR switching mechanism is fully pulled out.

FIG. 14 is a main part plan view showing an ALR switching state of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

FIG. 15 is a main part plan view showing an ALR release start state of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

FIG. 16 is a main part front view showing an ALR release completion state of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention;

FIG. 17 is a main part front view showing an operation state of end lock prevention of an ALR / ELR switching mechanism of the webbing take-up device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Main body frame 12A Leg 12B Leg 14 Winding shaft 16 Sensor cover 18 Lock wheel 20 External ratchet wheel 22 ALR pawl 24 Sensor pawl 26 Sensor plate 28 Holder 30 Disk control 32 Cam member 34 Ratchet member 36 Rotor 47 First drive Gear 50 Internal tooth ratchet tooth part 62 Interlocking stop part 62A Interlocking part 62B Interlocking part 64 Stopping part 66 Guide surface part (Stopping part) 68 Cam rotation gear 76 Stopping operation part 76A Contact end part 77 Stopping rib part 78 Contact rib part Reference Signs List 80 Guide hypotenuse 96 Reduction gear 98 Interlocking gear 106 Shaft hole 108 Claw 120 Acceleration sensor device 132 Claw

Claims (2)

[Claims] A winding shaft for winding the webbing for restraining an occupant; a lock unit for stopping rotation of the winding shaft in a webbing pull-out direction; An ALR pawl that is engaged with the lock means or moves against a biasing force to a position where the operation of the lock means is released, and is mounted so as to be able to release the engagement with the lock means; A first drive gear that rotates, a speed reduction mechanism that operates intermittently with a reduction gear that meshes with the first drive gear, and a stop that is rotated in conjunction with the speed reduction mechanism and that has a guide surface portion in part thereof And a cam member provided with an interlocking stop portion, and a disc control provided with a stop operation portion while being rotated by the interlocking stop portion of the cam member. On the axis In normal use until the wound webbing is pulled out to near its full amount, the disc control stop operation unit is positioned so as to hold the ALR pawl at a position where the operation of the lock unit is released. Immediately before pulling out the entire webbing, the cam member interlocking with the winding shaft rotates the disc control to move the ALR pawl from the stopping operation section onto the interlocking stopping section, and the ALR pawl. Is held at a position where the operation of the locking means is released, and when the webbing is started to be fully retracted from the drawn-out state, the cam member interlocked with the winding shaft rotates, and the ALR pawl is moved from the interlocking stopper. ALR is released by setting the lock means to the position where the lock means is operated.
When the webbing is wound in a predetermined amount, the rotating cam member rotates the disc control, and the stopping operation unit releases the operation of the locking means on the ALR pawl. A webbing take-up device characterized in that the webbing take-up device is set so as to be held at a position. 2. A stop portion of the cam member is configured to hold the sensor pawl of the acceleration sensor device from being engaged with the locking means during a period from a state in which the webbing is fully retracted to a state in which the webbing is pulled out by a predetermined amount. The webbing take-up device according to claim 1, wherein: