JPH0241092Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a webbing winding device for winding up webbing for restraining an occupant, which is used in a seat belt device for protecting an occupant in a vehicle emergency.

[Background Art] In a seat belt device, one end of a webbing for restraining an occupant is wound up and stored in a webbing take-up device.

This webbing retractor is provided with a lock mechanism to ensure that the occupant is restrained by the webbing in the event of a vehicle emergency. As this locking mechanism, an automatic locking mechanism that prevents the webbing from being pulled out after the occupant has put on the webbing is widely used.

This automatic locking mechanism detects when the occupant attaches and releases the webbing by the rotation of the webbing take-up shaft, and a control board controls a pole that engages with a ratchet foil fixed to the webbing take-up shaft, allowing the occupant to attach and release the webbing. The system is designed to prevent withdrawals.

However, in conventional webbing retractors, the means for detecting the rotation of the retracting shaft and controlling the movement of the poles is complicated, or the operation is unstable, making it difficult to operate reliably after long periods of use. Sometimes you can't get it.

[Purpose of the invention] Taking the above-mentioned facts into consideration, the object of the present invention is to provide a webbing retractor that has a simple structure and can reliably restrain the occupant after the occupant has attached the webbing.

[Structure of the invention] In order to achieve the above object, the webbing take-up device according to the present invention is provided with a take-up shaft pivotally supported on the main body, and a pole engages with a ratchet foil fixed to the take-up shaft to take up the webbing. A webbing take-up device in which rotation of a shaft in a webbing pull-out direction is prevented,
a separating means for separating the pole from the ratchet foil when a predetermined amount or more of the webbing is wound around the winding shaft; a small ratchet foil fixed to the winding shaft; an annular control plate coaxially and rotatably supported; and an elastic pawl formed on the inner periphery of the control plate to engage with the small ratchet foil and to be elastically deformable in directions toward and away from the small ratchet foil; A pin fixed to the main body so as to be located near the outer periphery of the control plate, and a pin protruding from the outer periphery of the control plate to prevent rotation in the direction in which the small ratchet foil and the elastic pawl portion of the control plate engage when abutting the pin. and a first protrusion that abuts the pole to separate the pole from the ratchet foil and deform the elastic pawl in a direction away from the small ratchet foil, and a position on the outer periphery of the control plate that faces the first protrusion with the pin in between. and a second protrusion formed in the lattice wheel that abuts the pin to prevent rotation of the control plate and abuts the pawl to separate the pawl from the ratchet wheel.

In the present invention, when the webbing is fully wound, the pole is separated from the ratchet foil by the separating means. Therefore, the webbing can be easily pulled out. When the occupant pulls out the webbing, the take-up shaft is rotated in the direction in which the small ratchet wheel and the elastic claw part engage, and the control plate is rotated in the webbing drawing direction by the engagement between the small ratchet wheel and the elastic claw part. When the control plate rotates in the direction of pulling out the webbing, the first protrusion and the pin come into contact with each other, and rotation of the control plate is prevented. In this state, the first
The protrusion contacts the pawl to separate the pawl from the ratchet foil, and also deforms the elastic pawl portion in a direction away from the small ratchet foil. Therefore, even if the winding diameter of the webbing becomes smaller due to being pulled out, the webbing can be easily pulled out.

After the pulled out webbing is attached to the passenger, it is wound up somewhat. As a result, the elastic pawl comes into contact with and engages with the small ratchet foil, the control plate rotates a little in the webbing winding direction together with the small ratchet foil, and the first protrusion no longer comes into contact with the pole, so that the pawl and the ratchet foil are no longer in contact with each other. engage.

When winding the webbing, the control plate rotates in the webbing winding direction while the small ratchet wheel and the elastic pawl are engaged with each other. When the control plate rotates in the winding direction, the second protrusion and the pin come into contact with each other, and rotation of the control plate is prevented. In this state, the second protrusion abuts the pawl and separates the pawl from the ratchet foil. Further, since the winding shaft rotates in the direction in which the engagement between the small ratchet wheel and the elastic pawl portion is released, the elastic pawl portion is elastically deformed by the small ratchet foil in a direction in which it is separated from the small ratchet foil, thereby causing the small ratchet foil to engage with the small ratchet foil. The connection is canceled. Therefore, the webbing can be easily wound up.

In this way, in this invention, when the occupant is wearing the webbing, the pole and the ratchet wheel are engaged, and when the occupant is wearing the webbing, the pole and the ratchet wheel are disengaged. The occupant can be reliably restrained, and when the occupant is not wearing the webbing, the webbing take-up shaft is not prevented from pulling out the webbing and rotating in the take-up direction. Also,
Since the engagement between the pawl and the ratchet wheel can be controlled by rotating the control plate provided with the protrusion, the webbing retractor can be constructed at low cost and simple.

Further, since the control plate is rotated by the engagement between the small ratchet wheel and the elastic claw, the control plate can be rotated reliably.

[Embodiment of the invention] Figs. 1 to 3 show a webbing retractor 10 to which the invention is applied.

In this webbing retractor 10, a base 12 is fixed to a vehicle body 16 with bolts 14. A pair of leg plates 18 and 20 protrude parallel to each other from both sides of the base 12, and pivotally support the vicinity of both ends of the webbing take-up shaft 22.

One end of an occupant restraining webbing 24 is locked to an intermediate portion of the take-up shaft 22. Further, a mainspring spring winding device 26 is provided between the end of the winding shaft 22 protruding from the leg plate 20 and the leg plate 2, thereby attaching the winding shaft 22 in the winding direction of the webbing 24. It's spinning around.

Further, ratchet wheels 28 are fixed to the winding shaft 22 on both sides of the webbing 24 so as to rotate together with the winding shaft 22. Corresponding to this ratchet wheel 28 is a pole 30 which is pivotally supported on the leg plates 18, 20. This pole 30 is the second and third
As shown in the figure, it is housed in a shaft support hole 32 formed in the leg plates 18, 20, and when it engages with the ratchet wheel 28, the rotation of the webbing drawer of the winding shaft 22 is stopped. .
Note that the pawl 30 and the pivot hole 32 are arranged above the ratchet wheel 28, and are adapted to engage with the ratchet wheel 28 by the weight of the pawl 30.

One end of a leaf spring 34 serving as a separating means is fixed to the pole 30, and the tip of the leaf spring 34 is formed in a substantially U-shape, and the webbing 24 is wound in layers onto the winding shaft 22. It is in contact with the outer periphery. When the occupant releases the webbing 24 and a predetermined amount or more of the webbing 24 is wound onto the take-up shaft 22 by the biasing force of the mainspring spring take-up device 26, the outer circumference of the webbing 24 becomes larger and the pole 30 It is pushed up and separated from the ratchet foil 28. However, when the passenger pulls out the webbing 24 and puts it on, the webbing 24
4 has a smaller outer diameter so that the pawl 30 can engage with the ratchet foil 28.

The end of the pole 30 protruding from the leg plate 18 is configured to be controlled by a control plate 38. That is, the control plate 38 is supported coaxially with the winding shaft 22 and is rotatable relative to the winding shaft 22, and inside the control board 38, an elastic pawl 40 having a plurality of teeth is arranged in a cantilever shape along the inner periphery. It stands out. The elastic pawl 40 can engage with ratchet teeth 44 of a small ratchet foil 42 fixed to the winding shaft 22, and each ratchet tooth 44 is formed with a slightly larger tip angle θ so that the elastic pawl 40 can be easily disengaged. It's summery.

Therefore, when the winding shaft 22 rotates, the ratchet teeth 44 engage the resilient pawls 40 to rotate the control plate 38. However, if rotation of the control plate 38 is prevented,
The elastic pawl 40 is separated from the ratchet teeth 44 by the small ratchet foil 42 (radially outward direction).
, and only the winding shaft 22 and small ratchet wheel 42 rotate. Since the control plate 38 in this embodiment is made of resin, the elastic claw 40 can be elastically deformed in the direction of the arrow using its base end as a fulcrum.

A first protrusion 46 and a second protrusion 48 are protruded from the outer periphery of the control plate 38 at a predetermined interval.
A pin 50 protruding from is arranged. As a result, the rotation of the control plate 38 when pulling out the webbing is controlled so that the pin 50 is connected to the first protrusion 46 as shown in FIG.
The control plate 3
The rotation of the webbing 8 when winding up the webbing is restricted to a second position where the pin 50 comes into contact with the second protrusion 48, as shown in FIG.

Further, when the control plate 38 is rotated to the first position, the first protrusion 46 comes into contact with the pawl 30 and pushes it up, as shown in FIG. 2, thereby separating the pawl 30 from the ratchet wheel 28. When the control plate 38 is slightly rotated from the first position in the winding direction, the pawl 30 is accommodated in the recess between the first protrusion 46 and the second protrusion 48, and the ratchet foil 2 of the pawl 30 is rotated.
It becomes possible to mesh with 8. When the control plate 38 further rotates in the winding direction, it reaches the second position shown in FIG.

Note that a cover 52 for covering the control plate 38 is provided on the outside of the leg plate 18.

Next, the operation of this embodiment will be explained.

1 and 3 show the webbing 24 in a fully wound state when the occupant has released the webbing 24 from being attached. In order to attach the webbing 24, the occupant can attach the intermediate portion of the webbing 24 by pulling out an end (not shown) of the webbing 24 and engaging the tongue plate attached to this end with the buckle device.

When the webbing is fully wound, the pole 30 is the leaf spring 3.
4, and when the occupant pulls out the webbing 24, the first protrusion 46 touches this pole 3.
Since the pawl 30 abuts on the lower side of 0, even if the outer diameter of the webbing 24 around the take-up shaft 22 is reduced, the pawl 30 will not engage with the ratchet wheel 28.

When the occupant puts on the webbing 24, the webbing 24 is moved by a slight amount to the winding shaft 22 due to slight changes in the occupant's posture and changes in the abdomen due to breathing, before or immediately after the occupant assumes the driving position. It is wound up.

As a result, the ratchet teeth 44 of the small ratchet wheel 42 rotate the control plate 38 counterclockwise in FIG. 3 via the elastic pawl 40. The control board 38 is the second
When moved into position, the pawl 30 fits between the first projection 46 and the second projection 48 so that the pawl 30 engages with the ratchet foil 28. Therefore, the take-up shaft 22 is prevented from rotating in the direction of pulling out the webbing.
The occupant is restrained by the webbing 24.
The operation of the control plate 38 in this manner is controlled by the ratchet teeth 44.
This is ensured by the engagement of the elastic claws 40 with the elastic claws 40.

Therefore, when the vehicle is in an emergency situation such as a collision, the occupant is securely restrained by the webbing 24 and safety can be ensured.

After the occupant releases the webbing 24, the webbing 24 is automatically wound onto the winding shaft 22 by the biasing force of the mainspring spring winding device 26. Since the ratchet wheel 28 has a serrated shape with one side inclined, the pawl 30 does not interfere with the rotation of the winding shaft 22 to wind up the webbing. Furthermore, in this embodiment, until the outer diameter of the webbing 24 becomes large, the protrusion 48 rotates in the winding direction and pushes up the pawl 30 as shown in FIG. It is possible to prevent abnormal noises. When the webbing 24 is reattached, the control plate 38 returns to the state shown in FIG. 3 by slightly pulling out the webbing 24, and the above-mentioned operations are repeated.

Note that in the above embodiment, the pole 3 is
It is also possible to generate a biasing force in the direction of engagement with the ratchet foil 28 towards zero.

[Effects of the invention] As explained above, in the webbing take-up device according to the invention, the small ratchet foil, the separating means, the control plate, the elastic pawl, the pin, the first protrusion, and the second protrusion are used to connect the pole and the ratchet foil. Since the engagement is controlled, the occupant can be reliably restrained after the occupant wears the webbing with a simple structure.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional front view showing an embodiment to which the webbing retractor according to the present invention is applied, and FIG.
3 is a sectional view taken along the line in FIG. 1, and FIG. 4 is a sectional view similar to FIG. 2 in a state in which the webbing is wound up. DESCRIPTION OF SYMBOLS 10... Webbing take-up device, 22... Take-up shaft, 24... Webbing, 28... Ratchet foil, 30... Pole, 34... Leaf spring, 38...
...Control board, 40...Elastic claw, 42...Small ratchet foil, 46...First protrusion, 50...Pin.

Claims (1)

[Scope of utility model registration request] A webbing retractor comprising a take-up shaft pivotally supported on the main body, and in which a pole engages with a ratchet foil fixed to the take-up shaft to prevent rotation of the take-up shaft in the webbing pull-out direction, the take-up shaft a spacing means for separating the pole from the ratchet foil when the webbing is wound up by a predetermined amount or more; a small ratchet foil fixed to the winding shaft; and a spacing means coaxial with the winding shaft so that the small ratchet foil is located inside an annular control plate rotatably supported on the
an elastic pawl formed on the inner periphery of the control plate that engages with the small ratchet foil and is elastically deformable in directions toward and away from the small ratchet foil; and a pin fixed to the main body so as to be located near the outer periphery of the control plate. ,
The small ratchet foil of the control plate is provided protruding on the outer periphery of the control plate, and when it comes into contact with the pin, prevents rotation in the direction in which the small ratchet foil of the control plate and the elastic claw part engage with each other. A first protrusion that deforms in a direction away from the small ratchet foil, and a first protrusion that is formed on the outer periphery of the control plate at a position facing the first protrusion with the pin in between, contacts the pin to prevent rotation of the control plate, and is attached to the pole. a second protrusion that abuts and separates the pole from the ratchet foil.