JPS5828613Y2 - seat belt retractor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a seatbelt retractor used in a seatbelt system for restraining and protecting an occupant during a vehicle emergency.

The seatbelt retractor uses a ratchet wheel that winds the remaining part of the occupant restraint webbing onto an energized take-up shaft, and allows it to be unwound freely during normal driving conditions, and which is fixed to the take-up shaft in case of a vehicle emergency. Generally, the unwinding of the webbing is instantly stopped by engaging the lock bar, thereby reliably restraining the occupant.

However, in such a seat belt retractor, when the lock bar engages with the ratchet wheel in the event of a vehicle emergency, the tooth tips of the lock bar collide with the tooth tips of the ratchet wheel, causing the lock bar to be repelled and ensuring that the lock bar is ratcheted. It takes a long time to engage the wheel and stop the unwinding rotation of the ratchet wheel and take-up shaft, and a considerable amount of webbing is unwound during this time, so the occupant is not fully restrained, which is a function that guarantees the safety of the occupant. There was a risk that it would be damaged.

Taking this fact into consideration, the present invention aims to prevent the lock bar from being bounced back by the tooth tips of the ratchet wheel in the event of a vehicle emergency, and to ensure that the lock bar engages with the ratchet wheel to instantly stop the unwinding rotation of the ratchet wheel and the winding shaft. The purpose of the present invention is to provide a seat belt retractor that can perform the following functions.

In order to achieve the above object distantly, a seat belt retractor according to the present invention includes a retracting shaft that is rotatably supported by a frame and retracts the occupant restraint webbing, a ratchet foil fixed to the retracting shaft, a lock bar that is supported by the frame and engages with a ratchet wheel during tilting to prevent unwinding rotation of the take-up shaft; and a lock bar that is supported by the frame and has an elongated hole partially drilled in the elongated hole. an actuating plate into which the end of the locker is fitted to tilt the locker during rocking; an upper protrusion formed on the lever of the acceleration detecting device through which a pin passes and is spaced from the pin at an appropriate distance; a balancer that is supported at two points and includes a pair of bowls that are disposed at a pitch different from the tooth tip pitch of the ratchet wheel and can be engaged with the ratchet wheel; A guide groove is formed that extends in the radial direction of the ratchet wheel and into which the pin can be inserted, and guides the balancer in the ratchet engagement direction during rocking and transfers the force in the ratchet wheel rotational direction of the balancer to the operating plate. and a guide member that transmits rocking force to the balancer, and the balancer is stably operated by the acceleration detection device so that the pole of the balancer is engaged with the ratchet wheel, and the balancer causes the balancer to operate as a swinging force. The structure is such that the lockper is tilted via an operating plate, and the lockper engages with the tips of the teeth of the ratchet wheel without colliding with them, thereby quickly blocking the unwinding rotation of the winding shaft.

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

As shown in FIGS. 1 to 3, the frame 10 is made of sheet metal and bent into a U-shape, and the winding shaft 16 is attached to substantially parallel legs 12 and 14 connected to both ends of the frame 10. The end portion of the webbing 18 is wound up in layers while being supported.

Further, this winding shaft 16 is provided with a mainspring spring winding device 20 between the end protruding from the foot portion 12 and the foot portion 12, so that the winding shaft 16 is moved in the winding direction of the webbing 18 (first direction).
(clockwise direction).

As a result, if the occupant pulls the webbing 18 against the urging force of the mainspring spring take-up device 20, the webbing can be pulled out while rotating the take-up shaft 16 in the unwinding rotation direction of the webbing 18 (clockwise in FIG. 1). It is now possible to move.

A pair of ratchet wheels 22 are fixed to both sides of the central portion of the winding shaft 16 around which the webbing 18 is wound so as to rotate together with the winding shaft 16. A lockper 26 is pivotably supported in a notch 24 formed in the ratchet wheel 2 so as to be tiltable.
I am facing 2.

The center of gravity of the lock par 26 is determined so that it is urged away from the outer periphery of the ratchet wheel 22 by its own weight, and when the lock par 26 is tilted against this urging, the ratchet wheel 22 They mesh to prevent the unwinding rotation of the ratchet wheel 22 and the winding shaft 16.

A thin plate-shaped actuation plate 30 is supported on the shaft end 28 protruding from the foot 14 of the winding shaft 16 through a bearing hole 32 that is the center of its swing. An elongated hole 34 is formed therein, and the end portion of the locking member 26 protruding from the foot portion 14 is fitted into the end portion.

The elongated hole 34 has an inner diameter slightly larger than the outer diameter of the lock par 26, and is dimensioned to come into contact with the lock par 26 when the operating plate 30 swings slightly about the winding shaft 16.

This operating play) 30 is fitted onto the shaft end 2 of the winding shaft.
8 is further fitted with a stopper 36, which is fixed to the leg portion 14 of the frame 10 with a mounting screw 38, and the actuating plate 3
0 of the actuating plate 30.
It acts as a stopper when swinging in the counterclockwise direction as shown in the figure.
When the actuating plate 30 is in contact with the stopper 36 in this manner, the locking member 26 is moved to a position where it does not come into contact with the ratchet wheel 22.

A tension coil spring 40 is interposed between the stopper 36 and the actuation plate 30 to urge the actuation plate 30 counterclockwise in FIG. When it is rotated clockwise in FIG. 1, the elongated hole 34 tilts the locking member 26 so that it engages with the ratchet wheel 22.

Next, an acceleration detection device 4 is provided at the bottom of the leg portion 14 of the frame 10.
2 is installed.

This acceleration detection device 42 is composed of a bracket 44, a pendulum 46, and a lever 48, and the bracket 44 is fixed to the foot 14 by a press-fit pin 50 and a stepped press-fit pin 52.

A through hole 54 with a vertical axis provided in this bracket 44
The T-shaped head 56 of the pendulum 46 is inserted into and screwed together with the pendulum 46, so that the pendulum 46 can detect acceleration and swing.

The lever 48 is pivotally supported by the large diameter portion of the stepped press-fit pin 52, and the downward protruding portion 57 is placed on the head 56 of the pendulum 46, so that it can rotate in response to the swinging of the pendulum 46. There is.

Further, this lever 48 is fitted with a U-shaped balancer 58 so as to be supported at two points.

That is, an upper protrusion 60 is formed in the middle part of the lever 48, and this protrusion 60 comes into contact with the ceiling surface 62 of the balancer 58 to constitute one fulcrum, and the pin 6 passing through the balancer 58
4 is interposed between the tip of the lever 48 and the ceiling surface 62 to constitute the other fulcrum.

Furthermore, this pin 64 is connected to the L
It is inserted into the guide groove 68 of the letter-shaped guide member 66.

This guide groove 68 is formed approximately in the radial direction of the ratchet wheel 22 (direction of contact with and away from the ratchet tooth surface).

Therefore, this balancer 58 is able to swing around one of two fulcrums, but when the lever 48 rotates, it is pushed up by the lever 48 and rotates together with the lever 48 until an external force is applied. It has become.

Further, from this balancer 58, a pair of plate-shaped bowls 7 are connected.
0.72 protrudes in the horizontal direction, passes through the window 74 of the foot portion 14, and faces the outer diameter of the ratchet wheel 22 with a slight distance therebetween.

These bowls 70, 72 are located at a far distance from the center of rotation of the lever 48 in the horizontal position when the lever 48 is not rotated, so that when the lever 48 is rotated, these bowls 70, 72 simultaneously enter the rotation trajectory of the ratchet wheel 22. 72 is located at a position slightly lower than the bowl 70 (see FIG. 4).

Incidentally, as shown in FIG. 3, a mounting hole 76 is bored in the lower part of the frame 10, and the frame 10 is fixed to an appropriate position on the vehicle via a mounting bolt 78 and a washer 80.

In this embodiment configured as described above, when the webbing 18 is mounted on a vehicle, the webbing 18 can be pulled against the biasing force of the mainspring spring winding device 20 to cause the winding shaft 16 to unwind and rotate. Since it can be rotated in the direction (direction of arrow B in FIG. 1), it can be easily attached.

Next, if the vehicle falls into an emergency situation such as a collision after the webbing 18 is attached, the pendulum 46 detects the acceleration of the vehicle and swings, so the head 56 is moved to the balancer 58 via the lever 48.
is pushed up toward the axis of the ratchet wheel 22.

At this point, the balancer 58 receives only the push-up blade from the head 56 of the pendulum 46, so it rotates around the press-fit pin 52, which is the center of rotation of the lever 48, and is guided by the guide groove 68 to move the ratchet wheel 22. is moved in the radial direction, and the bowl 70.72 is inserted into the rotational trajectory of the ratchet wheel 22.

At this time, the balancer 58 is lifted around the stepped press-fit pin 52, but since it is moved in the radial direction of the ratchet wheel 22 along the guide groove 68, the ceiling surface 62 of the balancer 58 and the upper protrusion 60 will defect.

In such a vehicle emergency situation, the occupant wearing the webbing 18 is violently thrown in the direction of the collision of the vehicle, so the ratchet wheel 22 is violently rotated in the webbing unwinding direction (direction of arrow B in Figure 1). Therefore, the plate-shaped bowls 70 and 72 that engage with the ratchet wheel 22 receive force in this unwinding rotation direction (in FIG. 5, the plate-shaped bowls 70 and 72
(receives rotational force before the bowl 70) This rotational force passes through the guide groove 68 and the guide member 66 to the operating play)
30 is transmitted as a force that rotates the winding shaft 30 around the winding shaft 16.

Therefore, the operating plate 30 has its elongated hole 34 connected to the locking member 2.
6 is tilted within the notch 24 and engaged with the ratchet wheel 22, so that the unwinding rotation of the ratchet wheel 22 and the winding shaft 16 is abruptly stopped, and the occupant wearing the webbing 18 is reliably restrained.

Considering the case where the plate-shaped bowl 72 is rebounded by the tooth tip of the ratchet wheel 22 at the initial point of engagement with the ratchet wheel 22 in such an emergency state of the vehicle, the plate-shaped bowl 72 is moved in the approximately radial direction of the ratchet wheel 22. (4th
．． 5), the plate-shaped bowl 72 is repelled rapidly in the direction away from the ratchet wheel 22, and accordingly the balancer 58 is guided by the pin 6.
It receives a rotational force in the direction of arrow C in FIG.

Therefore, the plate-shaped bowl 70 protruding from the other side of the balancer 58 is reliably engaged with the ratchet wheel 22 by the strong rotational force of the balancer 58, and the operating plate 30 is moved onto the winding shaft 1.
It can be rotated 6 times.

Therefore, even if one of the bowls 72 is rebounded by the tooth tip of the ratchet wheel, the locking member 29 can be reliably engaged with the ratchet wheel 22.

Here, as shown in FIG. 4, a plate-shaped bowl 70.7 is provided.
Pitch P of 2 and pitch Q between the tooth tips of ratchet wheel 22
By making the bowls 70 or 72 different from each other, even if one bowl 70 or 72 is repelled by the tooth tips of the ratchet foil 22, the other bowl will surely mesh with the ratchet foil 22 without colliding with the tooth tips of the ratchet foil. This is an added feature.

Also, when one of the bowls 70 and 72 engages with the ratchet wheel 22, the locking member 26 is tilted at the same time.
It is easily possible to arrange the tooth tip of the ratchet wheel 22 so that it is inserted between the tooth tips of the ratchet wheel 22 and does not collide with the tooth tips of the ratchet foil.

In the above operation, it is extremely easy to design the balancer 58 to have a low center of gravity so that it will not rotate due to inadvertent vibrations, and each plate-shaped bowl is guided by the operating plate and connected to the ratchet wheel. Since it rotates together with the lever 48 until it engages, it is extremely stable when moved by the acceleration detection device, and even when it engages with the ratchet wheel, the guide member 66 prevents it from moving in the axial direction of the ratchet wheel. It is certain.

Since the balancer 58 is supported by the lever 48 at two points, the stability of the balancer 58 can be improved when it is operated by the acceleration detection device 42, as described above.

Moreover, since this two-point support is a mode in which the balancer 58 is placed on the upper protrusion 60 and the pin 64, the balancer 58 is placed on the lever 44.
8 rotates around the stepped pin 52, and when the pin 64 moves in the radial direction of the ratchet wheel 22 along the guide groove 68, the ceiling surface 62 of the balancer 58 and the upper protrusion 60 separate, and the balancer 58 can be moved horizontally, so that even when the bowl 72 is repelled by the ratchet wheel 22, the other bowl 7
0 can be instantly engaged with this ratchet wheel 22.

Furthermore, since the balancer 58 is supported by two points,
When the bowl 72 is bounced back by the ratchet foil 22, the ceiling surface 62 of the balancer 58 and the upper protrusion 60 are separated, the bowl 70 rotates around the pin 64, and can mesh with the ratchet foil 22.

In the present invention, the plate-shaped bowls 70 and 72 do not directly lock the ratchet wheel, and the force for stopping the ratchet wheel is taken care of by the locker 26, so the plate-shaped bowls are extremely sharp compared to the teeth of the locker 26. It can be made.

Therefore, the chances of the plate-shaped bowl colliding with the tips of the teeth of the ratchet wheel 22 are extremely small.

Since the seat belt retractor according to the present invention has the above-described structure, the tooth tip of the lockper does not collide with the tooth tip of the ratchet foil and is repelled, but reliably engages with the ratchet foil to speed up the unwinding of the webbing. The safety of the passengers is guaranteed.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the seat belt retractor according to the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is an exploded perspective view, and Figs. 4 and 5 are ratchet wheels. FIG. 3 is an explanatory diagram showing the relationship between the bowl and the lockper. 10... Frame, 16... Winding shaft,
18...Webbing, 22...Ratchet foil, 26...Lock par 30...
... Actuation plate, 42 ... Acceleration detection device,
58... Balancer, 66... Guide member, 70, 72... Bowl.

Claims (1)

[Scope of utility model registration request] a take-up shaft that is pivotally supported by the frame and winds up the occupant restraint webbing; a ratchet foil that is fixed to the take-up shaft;
a lock bar that is supported by the frame and engages with a ratchet wheel during tilting to prevent unwinding rotation of the take-up shaft; and a lock bar that is supported by the frame and has an elongated hole partially drilled in the elongated hole. an actuating plate to which an end of the lock bar is fitted and which tilts the lock bar during rocking, and a pin is passed through the actuating plate;
The lever is supported at two points by the upper protrusion formed on the lever of the acceleration detection device at an appropriate distance from the pin and the pin, and is disposed at a pitch different from the tooth tip pitch of the ratchet wheel. a balancer comprising a pair of bowls that can be engaged with a ratchet foil;
A guide groove is formed that is fixed to the actuating plate, extends in the radial direction of the ratchet wheel, and allows the pin to be inserted therein, and guides the balancer in the ratchet meshing direction during rocking and also guides the balancer in the ratchet engagement direction. A seat belt retractor comprising: a guide member that transmits a ratchet wheel rotational force to the actuating plate as a swinging force.