JP6765391B2 - Retractor for seat belt - Google Patents

Description

The present invention relates to a seatbelt retractor, and more particularly to an improvement of a seatbelt retractor capable of suppressing sudden winding of a webbing and preventing the occurrence of an end lock.

Conventionally, as a seatbelt retractor for safely holding a vehicle occupant or the like in a seat, an emergency lock mechanism for physically locking the webbing drawer by a vehicle body acceleration sensing means that reacts to sudden acceleration, collision or deceleration is provided. Therefore, an emergency lock type retractor that effectively and safely restrains the occupant is used.

By the way, in a seatbelt retractor provided with an emergency lock mechanism, the rotation of the spindle (winding shaft) in the webbing pull-out direction may be locked even when the vehicle is not in an emergency and is unnecessary. That is, when the entire amount of webbing is suddenly wound from the webbing pull-out state according to the spring force of the take-up spring in the vehicle-mounted state, the emergency lock mechanism is activated by the impact to lock the rotation of the spindle in the webbing pull-out direction. In this case, the webbing cannot be pulled out. Moreover, at this time, since the entire amount of webbing is in the winding state, the spindle cannot rotate in the webbing winding direction, and the retractor falls into a so-called end-locked state.

For example, the emergency lock mechanism includes the following. One is to detect the sudden pull-out of the webbing and prevent the rotation of the spindle in the webbing pull-out direction (webbing acceleration sensing means: WS), and the other is to detect the sudden deceleration state of the vehicle and pull out the webbing of the spindle. It prevents rotation in the direction (vehicle body acceleration sensing means: VSI). In either case, the claws of the lock member are engaged with the internal teeth of the frame that supports the spindle by swinging the lock member that rotates integrally with the spindle to lock the spindle.

In such a retractor, there are the following three cases where end lock occurs.
Due to careless operation of the webbing acceleration sensing means (WS).
In general, the webbing acceleration sensing means has the principle that when the belt is pulled out rapidly, the rotation of the mass side is delayed from the spindle due to the inertia of the mass, so that the lock member pops out and bites into the internal teeth of the frame. Is used. However, when the webbing is stretched after a sudden winding of the webbing, the mass moves relative to the spindle with force, and the lock member bites into the internal teeth of the frame. Insufficient vehicle body acceleration sensing means (VSI) Due to a prepared operation.
This is a case where the ball, which is an inertial member, moves, the lever swings, and bites into the latch member to lock when acceleration is input to the vehicle body acceleration sensing means due to the vibration of the retractor due to the rapid winding of the webbing. ..
Due to careless operation of the lock member itself.
This is a case where the lock member itself bites into the internal teeth of the frame due to the momentum of winding up the webbing.

In the seatbelt retractor described in Patent Document 1, in order to prevent end lock due to careless operation, an end lock prevention mechanism that suppresses the winding outer diameter of the webbing to suppress the winding speed when the webbing is stored is provided. Are known.

Japanese Unexamined Patent Publication No. 2010-120527

However, in the seatbelt retractor described in Patent Document 1, if the webbing winding outer diameter at the time of storage differs depending on the vehicle layout, it becomes necessary to set the seatbelt retractor for each vehicle type, which causes a problem that the cost increases. ..

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to detect sudden winding of a webbing, suppress the winding speed to prevent the occurrence of end locks, and tongues and interior parts. It is an object of the present invention to provide a retractor for a seat belt that can prevent damage due to interference with the vehicle.

The above object of the present invention is achieved by the following configuration.
(1) A spindle that is rotatably supported by the frame and wound with webbing,
The bearing case fixed to the frame and
A latch ring having internal teeth formed on the inner peripheral surface and rotatably arranged with respect to the bearing case.
A plate rotatably connected to the spindle and
An operating position that is oscillatingly supported by the plate at a position that can be engaged with and disengaged from the internal teeth of the latch ring and engages with the internal teeth of the latch ring, and the internal teeth of the latch ring. A webbing take-up sensor lever that displaces between the disengaged position and
An urging member supported by the plate and urging the webbing take-up sensor lever toward the non-operating position.
With
When the webbing is wound at a predetermined speed or higher, the webbing winding sensor lever moves to the operating position, and when the latch ring rotates, a braking unit that applies a braking force to the latch ring is provided. A retractor for seat belts that is characterized by this.
(2) The bearing case is provided with an annular latch ring support portion that guides the outer peripheral surface of the latch ring.
The seatbelt retractor according to (1), wherein the braking portion is provided on the latch ring support portion, and the latch ring rotates to generate sliding friction on the latch ring.
(3) A locking member that locks the rotation of the spindle in the webbing pull-out direction by engaging with the frame.
A steering wheel that is supported by the spindle so as to be relatively rotatable and that operates the lock member by causing a rotation delay with respect to the spindle.
The bearing case with teeth formed on the inner peripheral surface and
When the webbing is oscillatingly supported by the steering wheel at a position where it can be engaged with and detached from the tooth portion of the bearing case and the webbing is pulled out at a predetermined speed or higher, the rotation of the steering wheel in the webbing pull-out direction is performed. Webbing drawer sensor lever to block and
The seatbelt retractor according to (1) or (2).
(4) The method according to (3), which has an acceleration sensor lever that can be locked with a tooth portion formed on the outer peripheral surface of the steering wheel, and further includes an acceleration sensor that detects acceleration in the horizontal direction. Retractor for seat belt.

According to the seatbelt retractor of the present invention, when the webbing is wound at a predetermined speed or higher, the webbing winding sensor lever moves to the operating position where it engages with the internal teeth of the latch ring, and the latch ring rotates. When doing so, a braking portion that applies braking force to the latch ring is provided. As a result, when a sudden winding of the webbing is detected, the winding speed of the spindle can be suppressed to prevent the occurrence of end lock. In addition, interference between the tongue and the interior parts can be prevented, and damage to the interior parts can be prevented.

It is a vertical sectional view of the retractor for a seat belt. It is an exploded perspective view of the main part of the retractor for a seat belt shown in FIG. (A) to (d) are side views showing the process of detecting the rapid winding of the webbing and engaging the internal teeth of the webbing winding sensor lever and the latch ring. (A) to (d) are side views showing a process in which a latch ring engaged with a webbing take-up sensor lever slides and rotates with respect to a bearing case, and a braking force is applied to the latch ring. FIGS. (A) to (D) are side views showing a process in which the engagement between the webbing take-up sensor lever and the internal teeth of the latch ring is released by reducing the rotational speed of the spindle.

Hereinafter, an embodiment of the seatbelt retractor according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a retractor for a seatbelt according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a main part thereof. As shown in FIGS. 1 and 2, the seatbelt retractor 1 is housed in a metal spindle 10 around which a webbing (not shown) is wound and a cover 12, and the spindle 10 is rotationally biased in the winding direction. A spring-type winding device 11, a metal U-shaped frame 13 that rotatably supports the spindle 10, a metal lock dock 20 as a lock member, a resin steering wheel 30, and inertia. The webbing pull-out sensor lever 41 (see FIG. 2) that also functions as a body, the bearing case 60 fixed to the frame 13, the latch ring 50 rotatably arranged on the bearing case 60, and the spindle 10 are integrated. A plate 70 that is rotatably connected, a webbing take-up sensor lever 80 that is oscillatingly supported by the plate 70 and has a function as an inertial body, and can be engaged with and detached from the internal teeth 51 of the latch ring 50, and a vehicle body. It mainly includes an acceleration sensor 90 as a vehicle body acceleration sensing means for detecting the acceleration of the bearing case 60, and a cover member 15 fixed to the frame 13 so as to cover the bearing case 60.

The frame 13 has left and right side plates 13A and 13B facing each other with the central portion in the axial direction of the spindle 10 interposed therebetween, and an emergency lock mechanism and an automatic lock mechanism are arranged on the outside of one side plate 13A, and the outside of the other side plate 13B. The take-up device 11 is arranged in. The shaft 14 on one end side of the spindle 10 penetrates the steering wheel 30 and the bearing case 60, and the square shaft 16 formed at the tip thereof fits into the square hole 71 (see FIG. 2) of the plate 70 and rotates integrally. It is fitted so that it does.

A large number of internal teeth 17 to which the claws 22 of the lock dock 20 can be engaged are formed on the inner circumference of the circular opening of the side plate 13A of the frame 13. The lock dock 20 is displaceably housed in a space secured on one end surface side of the spindle 10, and a claw 22 is held in an unlocking direction away from the internal teeth 17 of the frame 13 by an omega spring (not shown). Further, the cam pin 21 of the lock dock 20 is inserted into the cam hole 31 formed in the steering wheel 30.

The steering wheel 30 is rotatably supported by the spindle 10, and as shown in FIG. 2, a convex shape that swingably supports the cam hole 31 with which the cam pin 21 of the lock dock 20 is engaged and the webbing drawer sensor lever 41. It has a shaft 32 and a tooth portion 33 formed on an outer peripheral surface.

The cam hole 31 pushes the claw 22 of the lock dock 20 outward through the cam pin 21 when the steering wheel 30 rotates relative to the spindle 10. Then, by engaging the claws 22 protruding outward with the internal teeth 17 of the frame 13, the spindle 10 is locked to the internal teeth 17 of the frame 13, and the rotation in the webbing pull-out direction is mechanically locked.

The webbing drawer sensor lever 41 includes a claw 42 that can be engaged with the tooth portion 61 of the bearing case 60, and is swingably fitted to the convex shaft 32 of the steering wheel 30. The claw 42 of the webbing pull-out sensor lever 41 is rotationally urged by the webbing sensor spring 58 in a direction in which the claw 42 is separated from the tooth portion 61 of the bearing case 60. Therefore, normally, the claw 42 is held apart from the tooth portion 61 of the bearing case 60. That is, the steering wheel 30, the webbing pull-out sensor lever 41, and the webbing sensor spring 58 constitute the webbing speed sensing means 40.

As a result, when the webbing is rapidly pulled out due to the movement of the occupant, the webbing pull-out sensor lever 41 is rotated by inertial force, the claw 42 of the webbing pull-out sensor lever 41 is projected outward, and the tooth portion of the bearing case 60 is formed. It meshes with 61. As a result, the webbing speed sensing means 40 prevents the steering wheel 30 from rotating in the webbing pull-out direction.

When the spindle 10 rotates relative to the steering wheel 30 whose rotation is blocked, the claw 22 of the lock dock 20 is pushed outward through the cam pin 21 and meshes with the internal teeth 17 of the frame 13, and the webbing of the spindle 10 Mechanically lock the rotation in the pull-out direction.

Further, the acceleration sensor 90, which is a vehicle body acceleration sensing means, is rotated by a sensor holder 91, an inertial body (ball) 92 housed in the sensor holder 91 and displaced according to the acceleration in the horizontal direction, and a support shaft (not shown). It is provided with an acceleration sensor lever 93 that is movably arranged and whose tip tip 94 approaches and separates from the tooth portion 33 formed on the outer peripheral surface of the steering wheel 30.

In the vehicle body acceleration sensing means, when horizontal acceleration is applied to the acceleration sensor 90 due to sudden deceleration of the vehicle or the like, the ball 92 moves according to the vehicle body acceleration, the acceleration sensor lever 93 swings, and the tip tooth tip 94 is the steering wheel 30. Engage with the tooth portion 33 of the steering wheel 30 to lock the steering wheel 30. As the spindle 10 rotates relative to the steering wheel 30, the claws 22 of the lock dock 20 mesh with the internal teeth 17 of the frame 13, mechanically lock the webbing drawer, and restrain the occupant in an emergency. To protect.

Further, the bearing case 60 is a substantially cup-shaped member including an annular portion 62 and a side wall 63. At the center of the side wall 63, a through hole 64 through which the shaft 14 on one end side of the spindle 10 penetrates is provided. An annular protrusion 65 is formed on the inner diameter side of the annular portion 62 so as to project from the side wall 63 in the spindle 10 direction. The plurality of tooth portions 61 described above are formed on the inner peripheral surface of the annular protrusion 65.

An annular latch ring support portion 66 is integrally formed on the surface of the side wall 63 opposite to the spindle 10. The latch ring support portion 66 is integrally formed with a plurality of cantilever arms 68 (three in the embodiment shown in FIG. 2) that are notched in an L shape in the axial direction and the circumferential direction and extend in the circumferential direction. On the inner diameter side of the tip of the cantilever arm 68, a convex portion 69 protruding toward the inner diameter side is provided.
Further, engaging claws 67 for slidably and rotatably supporting the latch ring 50 are provided at three locations in the circumferential direction of the axial tip portion of the latch ring support portion 66.

The latch ring 50 is formed in a ring shape having a plurality of internal teeth 51 provided on the inner peripheral surface, and is rotatably fitted in the latch ring support portion 66 of the bearing case 60 fixed to the frame 13. The convex portion 69 is in contact with the outer peripheral surface of the latch ring 50 that fits inside the latch ring support portion 66 due to the elastic force of the cantilever arm 68. As a result, the latch ring 50 rotates with respect to the bearing case 60, so that sliding friction is generated between the latch ring 50 and the bearing case 60, and a braking force is applied to the latch ring 50.
That is, the cantilever arm 68 formed on the bearing plate 60 functions as a braking portion of the latch ring 50. However, the structure is not particularly limited as long as it can apply a braking force to the latch ring 50 when the latch ring 50 rotates, and the braking portion simply generates sliding friction with the latch ring 50. It may be a cylindrical surface of the ring support portion 66.

The plate 70 includes a boss 72 having a square hole 71, a convex shaft 73 that swingably supports the webbing take-up sensor lever 80, and a spring receiver 74. A square shaft 16 formed at the tip of the shaft 14 of the spindle 10 is fitted into the square hole 71 of the boss 72, and the plate 70 and the spindle 10 rotate integrally.

The webbing take-up sensor lever 80 includes a claw 81 that can be engaged with the internal teeth 51 of the latch ring 50, and is swingably fitted to the convex shaft 73 of the plate 70. A lever spring 82 is arranged between the spring receiver 74 and the webbing take-up sensor lever 80. The webbing take-up sensor lever 80 is urged in a direction in which the claw 81 is separated from the internal teeth 51 of the latch ring 50 by the elastic force of the lever spring 82.

Therefore, normally, the claw 81 is held in a non-operating position away from the internal teeth 51 of the latch ring 50. That is, the bearing case 60, the latch ring 50, the plate 70, the webbing take-up sensor lever 80, and the lever spring 82 constitute the end lock prevention means 55.
The end lock prevention means 55 acts when the webbing is pulled out, whereas the webbing speed sensing means 40 and the vehicle body acceleration sensing means (acceleration sensor 90) act when the webbing is wound up.

Hereinafter, the operation of the end lock prevention means 55 will be described with reference to FIGS. 3 to 5.
When the tongue inserted in the buckle is disengaged, the webbing is rapidly wound around the spindle 10 by the elastic force of the winding device 11. As shown in FIGS. 3A to 3D, when the webbing take-up sensor lever 80 rotates at a predetermined speed or higher together with the plate 70 as the spindle 10 rotates, the webbing take-up sensor lever 80 is displaced by centrifugal force. It swings around the convex shaft 73 against the elastic force of the lever spring 82 and is displaced to the operating position, and the claw 81 engages with the internal teeth 51 of the latch ring 50. As a result, the latch ring 50 rotates integrally with the plate 70.

Then, as shown in FIGS. 4A to 4D, when the latch ring 50 slides and rotates with respect to the bearing case 60, the latch ring in which the convex portion 69 comes into contact with the outer peripheral surface due to the elastic force of the cantilever arm 68. A sliding resistance (braking force) with the convex portion 69 acts on the 50 to suppress the rotation, and the rotation speed of the plate 70, that is, the spindle 10 is suppressed. As a result, the occurrence of end lock during winding of the webbing is suppressed.

Then, as shown in FIGS. 5A to 5D, when the rotational speed of the plate 70 eventually decreases due to the sliding resistance acting on the latch ring 50, the webbing take-up sensor lever 80 becomes elastic of the lever spring 82. Due to the force, the tip swings in the opposite direction about the convex shaft 73, the engagement between the claw 81 and the internal tooth 51 of the latch ring 50 is released, and the lever returns to the non-operating position. Then, the webbing is in a state of being wound around the spindle 10.

According to the seatbelt retractor 1 of the present embodiment, since the winding speed of the webbing is suppressed, the occurrence of the end lock of the webbing is suppressed, and the sudden interference between the tongue and the interior parts is prevented. It is possible to prevent damage to interior parts.

As described above, according to the seatbelt retractor 1 of the present embodiment, the spindle 10 rotatably supported by the frame 13 and wound with webbing, and the bearing case 60 fixed to the frame 13 are included. The latch ring 50 having internal teeth 51 formed on the peripheral surface and rotatably arranged with respect to the bearing case 60, the plate 70 rotatably connected to the spindle 10, and the internal teeth 51 of the latch ring 50. At a position where it can be engaged and disengaged, it is oscillatingly supported by the plate 70, and the operating position where the latch ring 50 engages with the internal teeth 51 and the engagement with the internal teeth 51 of the latch ring 50 are released. A webbing take-up sensor lever 80 that is displaced from the position and an urging member 82 that is supported by the plate 70 and urges the webbing take-up sensor lever 80 toward the non-operating position are provided, and the speed is equal to or higher than a predetermined speed. When the webbing is wound up, the webbing winding sensor lever 80 moves to the operating position, and when the latch ring 50 rotates, a cantilever arm 68 that applies a braking force to the latch ring 50 is provided. As a result, when a sudden winding of the webbing is detected, the winding speed of the spindle 10 can be suppressed to prevent the occurrence of end lock. In addition, interference between the tongue and the interior parts can be prevented, and damage to the interior parts can be prevented.

Further, the bearing case 60 is provided with an annular latch ring support portion 66 that guides the outer peripheral surface of the latch ring 50, a cantilever arm 68 is provided on the latch ring support portion 66, and the latch ring 50 rotates. As a result, sliding friction is generated in the latch ring 50, so that the rotation of the latch ring 50 can be suppressed with a relatively simple configuration, and the rotation speed of the spindle 10 is suppressed.

Further, the lock dock (lock member) 20 that locks the rotation of the spindle 10 in the webbing pull-out direction by engaging with the frame 13 is supported by the spindle 10 so as to be relatively rotatable, and a rotation delay is delayed with respect to the spindle 10. The steering wheel 30 that operates the lock dock 20 when generated, the bearing case 60 having the tooth portions 61 formed on the inner peripheral surface, and the steering wheel 30 at a position where it can be engaged with and detached from the tooth portions 61 of the bearing case 60. The steering wheel 30 is provided with a webbing pull-out sensor lever 41 that is movably supported and prevents the steering wheel 30 from rotating in the webbing pull-out direction when the webbing is pulled out at a predetermined speed or higher, so that when the webbing is pulled out rapidly. The webbing pull-out sensor lever 41 prevents the steering wheel 30 from rotating in the webbing pull-out direction, so that the claws 22 of the lock dock 20 mesh with the internal teeth 17 of the frame 13 to prevent the webbing from being pulled out.

Further, since it has an acceleration sensor lever 93 that can be locked with the tooth portion 33 formed on the outer peripheral surface of the steering wheel 30, and further includes an acceleration sensor 90 that detects acceleration in the horizontal direction, it is horizontal due to sudden deceleration of the vehicle or the like. When acceleration is applied, the claws 22 of the lock dock 20 and the internal teeth 17 of the frame 13 mesh with each other to mechanically lock the webbing drawer. This makes it possible to restrain and protect the occupants in an emergency.

The present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, and the like.
For example, in the above embodiment, it has been described that a braking force is applied to the latch ring 50 by the elastic force of the cantilever arm 68 integrally formed with the bearing case 60, but the present invention is not limited to the cantilever arm 68, and a resin spring or a metal spring is used. A member (braking portion) separately attached to the bearing case 60 such as the above may generate sliding resistance in the latch ring 50.

Further, the end lock prevention means 55 of the present invention operates as a seatbelt retractor for fixing a child seat or the like to a vehicle seat with a seatbelt when the entire amount of webbing is pulled out, and prevents the webbing from being pulled out during winding. However, it can also be applied to those equipped with an automatic locking mechanism that releases the operation when the entire amount of webbing is wound up.

1 Retractor for seat belt 10 Spindle 13 Frame 20 Lock dock (lock member)
30 Steering wheel 33 Tooth 40 Webbing speed sensing means 41 Webbing drawer sensor lever 50 Latch ring 51 Internal tooth 55 End lock prevention means 60 Bearing case 61 Tooth 70 Plate 80 Webbing take-up sensor lever 82 Lever spring (biasing member)
90 Acceleration sensor (vehicle body acceleration sensing means)
93 Accelerometer lever

Claims (3)

A spindle that is rotatably supported by the frame and wound with webbing,
The bearing case fixed to the frame and
A latch ring having internal teeth formed on the inner peripheral surface and rotatably arranged with respect to the bearing case.
A plate rotatably connected to the spindle and
An operating position that is oscillatingly supported by the plate at a position that can be engaged with and disengaged from the internal teeth of the latch ring and engages with the internal teeth of the latch ring, and the internal teeth of the latch ring. A webbing take-up sensor lever that displaces between the disengaged position and
An urging member supported by the plate and urging the webbing take-up sensor lever toward the non-operating position.
With
When the webbing is wound at a predetermined speed or higher, the webbing winding sensor lever moves to the operating position, and when the latch ring rotates, a braking unit that applies a braking force to the latch ring is provided. ,
The bearing case is provided with an annular latch ring support portion that guides the outer peripheral surface of the latch ring.
The brake portion is provided on the latch ring support portion, and the retractor for a seat belt is characterized in that sliding friction is generated in the latch ring by rotating the latch ring . A locking member that locks the rotation of the spindle in the webbing pull-out direction by engaging with the frame,
A steering wheel that is supported by the spindle so as to be relatively rotatable and that operates the lock member by causing a rotation delay with respect to the spindle.
The bearing case with teeth formed on the inner peripheral surface and
When the webbing is oscillatingly supported by the steering wheel at a position where it can be engaged with and detached from the tooth portion of the bearing case and the webbing is pulled out at a predetermined speed or higher, the rotation of the steering wheel in the webbing pull-out direction is performed. Webbing drawer sensor lever to block and
The seatbelt retractor according to claim 1, further comprising . The seatbelt according to claim 2 , further comprising an acceleration sensor that has an acceleration sensor lever that can be locked with a tooth portion formed on the outer peripheral surface of the steering wheel and that detects acceleration in the horizontal direction. Retractor.

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