JPS6216113Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a webbing take-up device for use in a seat belt device for protecting an occupant in a vehicle emergency, and for winding webbing for restraining an occupant.

A webbing take-up device used in a seat belt device uses a biasing force to wind up the end of the webbing for restraining an occupant, and in the event of a vehicle emergency, a lock device is used to instantly stop unwinding of the webbing.

This locking device has great strength because it is necessary to reliably support the inertia of the occupant who moves violently in the direction of collision in the event of a vehicle emergency. For this reason, conventionally, a locking means has been widely used in which a ratchet wheel is fixed to the winding shaft, and a lock bar pivotally supported by a frame is engaged with the ratchet wheel. However, although this meshing means consisting of a ratchet wheel fixed to the winding shaft and a lock bar securely locks the winding shaft, it has the disadvantage of increasing the outer diameter of the webbing winding device.

In addition, in a lock mechanism that does not use a combination of a ratchet wheel and a lock bar fixed to the winding shaft, the lock member rotating together with the winding shaft may become unbalanced, or the lock member may wobble between the winding shaft and the response acceleration. This causes instability.

In consideration of the above facts, the present invention aims to provide a webbing retractor which is small in size, has high strength when locked, and has stable response acceleration.

The webbing retractor according to the present invention has an internally toothed ratch foil fixed to the frame, and a lock member that is capable of moving a lock ring that causes a rotation delay with respect to the rewind shaft by a predetermined amount relative to the rewind shaft in the event of a vehicle emergency. The winding device is made smaller by having a structure that meshes with the internal toothed ratch wheel and stops the webbing unwinding rotation of the winding shaft, and the pin protruding from the lock member is accommodated in the elongated hole provided in the lock ring to constitute the guide means. As a result, the locking member is guided without play to stabilize the response acceleration, and when the lock is locked, the pin is housed in a wide part provided in a part of the elongated hole, thereby preventing damage to the guide means.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, a webbing retractor 10 according to this embodiment has a frame 12 fixed to a vehicle body 16 by mounting bolts 14.

A winding shaft 22 is pivotally supported by leg portions 18 and 20 extending parallel to each other from both sides of the frame 12. One end of the occupant restraining webbing 24 is wound in layers around the center of the winding shaft. Further, the inner end of a mainspring spring 26 is attached to the end of the winding shaft 22 passing through the leg 20, and the outer end of this mainspring spring is locked to a spring case 28 fixed to the leg 20. Therefore, the winding shaft 22 is biased in the winding direction of the webbing 24 (in the direction of arrow A in FIGS. 2 and 3).

An internal tooth ratchet foil 30 is provided on the outside of the leg portion 18.
is fixed with four rivets 32. As shown in FIG. 4, a pair of lock plates 34 and 36 are provided within the internal ratchet wheel 30 and serve as lock members.

These lock plates 34 and 36 have a rectangular protrusion 3 in the center that is a radial protrusion of the winding shaft 22.
A recess 40 for receiving the lock plate 8 is provided, so that the overall shape of the lock plates 34, 36 is approximately C-shaped. Also, both ends of this C-shape,
In other words, the lock plate 3 sandwiching the winding shaft 22
The end faces 42 of the winding shafts 4 and 36 are arranged on a straight line including the axis of the winding shaft 22, and serve as a contact surface with the other lock plate. Here, this end surface 42 is a sliding surface on which the pair of lock plates 34 and 36 move in opposite directions while sliding against each other when moving to the locked state shown by the two-dot chain line in FIG.

A lock pawl 44 is formed in a part of the outer periphery of the pair of lock plates 34 and 36, and when the lock plates 34 and 36 slide against each other on the end surfaces 42 and move in opposite directions, the internal tooth ratch wheel 30
The rotation of the lock plates 34, 36 about the winding shaft is stopped by meshing with the winding shaft. Therefore, the lock plates 34, 36 and the rectangular protrusion 38 (take-up shaft 22) can move relative to each other from the state shown by the solid line in FIG. 5 to the state shown by the two-dot chain line.

A pair of pins 46 are attached to the winding shaft 22 from the opposite surfaces of the lock plates 34 and 36 from the leg portions 18, respectively.
protrudes parallel to.

A support shaft 48 is coaxially attached to the rectangular protrusion 38 of the winding shaft 22 so as to rotate in pairs with the winding shaft 22. An inertia plate 50 serving as a locking wheel is rotatably supported on this support shaft 48 so as to be rotatable relative to the support shaft 48.As shown in FIG. A hole 52 is formed and corresponds to the pin 46. These elongated holes 52 have a width pinched part 52A on one side and a wide part 52B on the other side, and the width of the width pinched part 52A is large enough to tightly accommodate the pin 46.
The width dimension of B is such that there is play between it and the outer periphery of the pin 46.

A pin 46 is accommodated in these elongated holes 52, and both constitute a guide means, and when the pin 46 is accommodated in the width sandwiching portion 52A, a pair of lock plates 34, 36 are inserted into each other as shown in FIG. is spaced apart from the internal tooth ratchet foil 30, and the pin 46 is separated from the wide portion 5.
2B, the locking pawl 44 of the locking plate is adapted to engage the internally toothed ratchet foil 30.

A torsion coil spring 54 is interposed between the inertia plate 50 and the support shaft 48, so that the inertia plate 50 is biased clockwise with respect to the winding shaft 22 in FIG. 3, that is, in the webbing unwinding direction of the winding shaft. ing. Therefore, when the take-up shaft 22 is unwound in the webbing unwinding direction at a predetermined acceleration or less, the inertia plate 50 receives the spring biasing force, follows the take-up shaft 22, and rotates in pairs with the take-up shaft 22. In this state, the pin 46 is accommodated in the width sandwiched portion 52A of the elongated hole 52. Further, when the webbing unwinding rotation of the take-up shaft 22 is performed rapidly, the inertia plate 50 bends the torsion coil spring 54 by its inertia force, causing a rotation delay with respect to the take-up shaft 22, and in this state, the pin 46 is Winding shaft 22
It moves to the wide part 52B of the elongated hole 52 in response to the unwinding rotational force of the elongated hole 52.

Note that when the winding shaft 22 performs normal unwinding and winding rotation, the recesses 40 of the lock plates 34 and 36
The relationship between the winding shaft rectangular protrusion 38 and the recess 40 is
A part of the winding shaft acts as a stopper 40A and comes into contact with the rectangular protrusion 38 of the winding shaft due to the biasing force of the torsion coil spring 54 and is stopped.

The inertia plate 50 has ratchet teeth 56 carved on its outer periphery, which correspond to the pawls 58 pivotally supported on the legs 18. The pawl 58 is pushed up by an inertia ball 62 housed within a case 60 of the leg 18 into engagement with the ratchet teeth 56. This inertial ball 62 separates the pawl 58 from the ratchet teeth 56 when the vehicle is normally running, but when the vehicle acceleration reaches a predetermined value, it moves and engages the pawl 58 with the ratchet teeth 56, causing the webbing of the inertia plate 50 to be wound. It is designed to stop rotation in the output direction. Therefore, this inertial ball 62 has a role as an acceleration sensor, and is designed to prevent rotation of the inertial plate 50 even when the inertial plate 50 does not lag in rotation with respect to the winding shaft 22 due to inertial force. It's summery. Note that a dust cover 64 is attached to the leg portion 18 and the internal tooth ratchet foil 3 is attached to the leg portion 18.
0, the inertia plate 50, the inertia ball 62, etc. are covered.

Winding device 10 of this embodiment configured as described above
Then, the occupant can unwind the webbing 24 from the take-up shaft 22 and attach it. This webbing 24
During the unwinding and winding operations in normal use, a large rotational acceleration is not generated on the winding shaft 22, so the inertia plate 50 rotates following the winding shaft 22, and the unwinding rotation of the winding shaft 22 is locked. There's nothing to do. During the rotation of the winding shaft 22 in this normal running state, the pins 46 of the lock plates 34, 36 are tightly accommodated in the width pinching portion 52A of the elongated hole 52, so that the lock plates 34, 36 are fixed to the rectangular shape of the winding shaft 22. There is no rattling between the shaped protrusion 38 and no noise generation.

When the vehicle is in an emergency situation such as a collision, the occupant wearing the webbing 24 moves violently in the direction of the collision, so the webbing 24 is suddenly unwound from the take-up shaft 22, causing the take-up shaft 22 to receive a large unwinding acceleration. is issued. For this reason, the inertia plate 50 causes a rotational delay with respect to the winding shaft 22, and the rectangular protrusion 38
The lock plates 34, 36 are driven in opposite directions through the lock plates 34 and 36 into engagement with the internally toothed ratchet wheel 30 as shown in FIG. Therefore, the webbing unwinding rotation of the take-up shaft 22 is stopped instantaneously, and the occupant is securely restrained by the webbing 24, thereby ensuring safety. In this locked state, the pin 46 is inserted into the wide portion 52 of the elongated hole 52 as shown by the two-dot chain line in FIG.
It is loosely housed in B.

Since the lock plates 34 and 36 are arranged in opposite directions with respect to the axis of the winding shaft 22, there is no unbalance during rotation, and the lock plates 34 and 36 remain in the pin position until they move to the locked state. 46 receives the driving force of the winding shaft rectangular protrusion 38 while being tightly housed in the width sandwiching portion 52A of the elongated hole 52, so that the lock plates 34 and 36 can be quickly engaged with the internally toothed ratchet wheel 30. .

Further, since the vehicle acceleration that occurs in a vehicle emergency moves the inertia ball 62, the pawl 58 meshes with the ratchet teeth 56 and the webbing unwinding rotation of the inertia plate 50 is stopped. Even if a relative rotation occurs between the webbing 22 and the occupant is not thrown in the direction of the collision, or before the occupant is thrown, the occupant can be restrained by the webbing 24.

In this locked state, the inertia plate 50 is prevented from rotating, while the pin 46 receives the driving force of the winding shaft rectangular protrusion 38 and receives rotational force around the axis of the winding shaft 22. Pin 46 is elongated hole 5
However, in this embodiment, since one of the elongated holes 52 is the wide portion 52B, the pin 46 and the wide portion 52B are moved in the locked state.
There is a gap between the pin 46 and the inner periphery of the pin 46, so that there is no risk of the pin 46 or the elongated hole 52 being destroyed. In addition, this wide portion 52B also includes a pin 46, lock plates 34, 36, and a rectangular protrusion 38 of the winding shaft.
The pin 46 and the elongated hole 5 are
Unnecessary load applied between the two in the width direction of the elongated hole 52 can be eliminated.

Since the lock plates 34 and 36 are arranged in opposite directions with respect to the axis of the winding shaft 22, no unbalance occurs during rotation, and in the locked state, the rectangular protrusion 38 of the winding shaft 22 applies a compressive force between the recess 40 and the lock pawl 44 to stop the unwinding rotation of the winding shaft 22, so the strength of the lock plates 34, 36 is extremely high, and there is no risk of the lock plates 34, 36 being destroyed. few.
Furthermore, the engagement between the lock plates 34 and 36 and the internally toothed ratchet wheel 30 generates locking force at two locations because the pair of lock plates are arranged symmetrically with respect to the axis of the winding shaft 22. , this also makes it possible to stabilize the lock state.

Webbing 2 if the vehicle's emergency status ends.
4 by winding up the lock plate 34,
36 is again separated from the internal toothed ratchet wheel 30 and becomes the state shown in FIGS. 1 and 3, and can be used as a normal winding device.

In this case, since the pin 46 accommodated in the wide part 52B in the locked state has a space between it and the wide part 52B, the pin 46 can easily enter into the wide part 52A, and the elongated hole 52 This eliminates the jamming between the pin 46 and the elongated hole 52 that would otherwise occur if the width of the pin 46 is the same as that of the width sandwiching portion 52A over the entire area, thereby smoothing the movement of the pin 46. Note that the stepped portion 52C between the width sandwiched portion 52A and the wide width portion 52B is tapered so that the width gradually becomes narrower from the wide width portion 52B to the width sandwiched portion 52A, so that the pin 46 can be further easily guided to the width sandwiched portion 52A. can do.

As explained above, the webbing retractor according to the present invention uses a combination of an internally toothed ratchet foil fixed to the frame and a lock member that meshes with this, so the outer diameter of the retractor is small, and the webbing retractor uses a combination of an internally toothed ratchet foil fixed to the frame and a lock member that meshes with the internal tooth ratchet foil. In the guide means consisting of an elongated hole provided in a locking wheel that accommodates the pin, the elongated hole has a narrow portion and a wide portion, so the pin is accommodated without any gaps, and the response of the vehicle in an emergency is stabilized. It has an excellent effect of eliminating unnecessary load applied between the pin and the elongated hole and preventing damage to the pin or the elongated hole.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the webbing retractor according to the present invention, Fig. 2 is a left side view of Fig. 1, Fig. 3 is a sectional view taken along the line of Fig. 1, and Fig. 4 is a locking mechanism section. FIG. 5 is an enlarged view showing the locking state of the locking mechanism, and FIG. 6 is an exploded perspective view showing the inertia plate in the first position.
It is a side view seen in the figure-line direction. 10... Winding device, 12... Frame, 22...
... Winding shaft, 24 ... Webbing, 30 ... Internal tooth ratchet foil, 34, 36 ... Lock plate, 46 ... Pin, 50 ... Inertia plate, 52 ... Elongated hole, 52A ... Width clamping part, 52B ...Wide part, 56
...Rachet teeth.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A frame attached to the vehicle body, a take-up shaft that is pivotally supported by the frame and winds up one end of the occupant restraint webbing, and a vehicle that is supported coaxially with the take-up shaft. a locking wheel that causes rotational delay with respect to the winding shaft in an emergency; an internally toothed ratchet wheel fixed to the frame; and a latch wheel that is supported by the winding shaft and moves from a first position to a second position with respect to the winding shaft. a lock member that is relatively movable up to a second position and that engages with the internally toothed ratch foil to prevent rotation of the take-up shaft in the webbing unwinding direction; a pin protruding from the lock member; and a long hole provided in the lock ring. The elongated hole accommodates the pin and guides the lock plate from the first position to the second position when the rotation of the lock wheel is delayed. A webbing take-up device comprising: a wide nipping portion that tightly accommodates the pin in the first state of the lock member; and a wide portion that loosely accommodates the pin in the second state of the lock member. (2) As set forth in claim 1 of the utility model registration claim, the lock plates are provided as a pair with the winding shaft interposed therebetween, and are guided by the guide means so as to be movable in opposite directions. Webbing retractor. (3) The webbing retractor according to claim 1 or 2, wherein the locking wheel is prevented from rotating by an acceleration sensor in the event of a vehicle emergency.