JPH037236Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a lock mechanism for a webbing retractor, which is used in a vehicle seat belt device and prevents the pulling out of occupant restraining webbing in a vehicle emergency.

[Background technology]

The lock mechanism for the webbing retractor stops unwinding the webbing from the retractor in the event of a vehicle emergency.
This ensures safety by keeping the occupant restrained by the webbing. Various types of lock mechanisms have been developed, and these can be broadly classified into mechanisms that prevent the rotation of the webbing take-up shaft, mechanisms that clamp the webbing, and mechanisms that combine both.

Further, lock mechanisms for preventing rotation of the winding shaft are divided into those that directly lock the winding shaft and those that lock the winding shaft indirectly through a lock ring and a lock plate. The former is a mechanism in which a locking wheel having ratchet teeth is fixed to the winding shaft, and in the event of a vehicle emergency, an acceleration sensor is activated and a pawl or trigger lever engages with the ratcheting teeth of the locking wheel. The latter differs from the former in that the lock wheel is not directly fixed to the winding shaft, but is similar in that an acceleration sensor and a pole prevent rotation of the lock wheel.

Further, as a means for preventing rotation of the lock ring, a mechanism is often used in which a pawl is engaged with ratchet teeth or notches provided around the lock ring. The separation of the pawl from the ratchet teeth is normally accomplished by utilizing the biasing force of a spring or the pawl's own weight.

However, if the webbing take-up device is installed at an angle for reasons of mounting on the vehicle body, it becomes difficult to separate the webbing take-up device from the ratchet teeth solely by the weight of the pole itself. In addition, in the case of a locking mechanism that operates the pole using the deflection of an inertial weight, the pole operating force due to this deflection is quite small, so it is difficult to design and manufacture a release spring that is suitable for this. There are drawbacks.

[Purpose of invention]

The present invention was devised in view of the above circumstances, and its purpose is to provide a webbing retractor with a pole that can be reliably separated from the locking wheel under its own weight even if the webbing retractor is installed at an angle to the vehicle body. An object of the present invention is to provide a lock mechanism for a webbing retractor.

[Structure of the idea]

In order to achieve the above object, the present invention engages a locking member such as a pole with a support portion of the locking member through a cam, so that the claw portion of the locking member is disengaged from the lock ring due to its own weight. It has been done. With this configuration, even in the case of an inclined webbing take-up device, the pole can be reliably disengaged, and a biasing member such as a spring can be omitted.

[Example of idea]

In the embodiment of the invention shown in FIG. 1, a frame 10 is secured to a vehicle body 14 with mounting bolts 12. A pair of leg plates 1 are attached from both sides of the frame 10.
6, 18 protrude, and these leg plates 16, 1
A webbing take-up shaft 20 is supported between the two.
In this embodiment, the webbing retractor is attached to the vehicle body 14.
A typical example is shown in which the winding shaft 20 is inclined at an angle of 90 degrees with respect to the horizontal line, that is, the winding shaft 20 is arranged so that its axis is in the vertical direction.

The winding shaft 20 winds one end of the occupant restraint webbing 22 in a layered manner, and a tongue plate (not shown) is attached to the other end of the webbing 22. Therefore, the occupant on the seat can put on the webbing by inserting the tongue plate into a buckle device (not shown) that stands up from the vehicle floor.

A mainspring spring 24 is provided between the winding shaft 20 and the end protruding from the leg plate 18.
4 is covered by a spring case 26. This mainspring spring 24 biases the winding shaft 20 in the webbing winding direction.

Further, a pair of lock rings 28 and 30 are fixed to the winding shaft 20 with the webbing 24 sandwiched therebetween, so that the lock rings 28 and 30 rotate together with the winding shaft 20. Corresponding to these lock wheels 28 and 30 is a long shaft-shaped pole 32 that is pivotally supported by the leg plates 16 and 18.
A pair of pawls 34 and 36 provided on the lock ring 2
The ratchet teeth 38, 40 of 8, 30 are adapted to engage with each other. Pawls 34, 36 and ratchet teeth 3
As can be seen from FIG. 2, the engagement of 8 and 40 prevents the lock wheels 28 and 30 and the take-up shaft 20 from rotating in the webbing unwinding direction, but allows them to rotate in the winding direction.

The end of the winding shaft 20 protruding from the leg plate 16 (the first
(upper end side in the figure) is covered with a cover 42.
An inertia lock mechanism 44 is housed inside. The inertia lock mechanism 44 locks the take-up shaft 20 and prevents the webbing 22 from being unwound when the webbing 22 is suddenly pulled out. Since this mechanism is well known, its details will be omitted.

An inertial weight 46 is swingably attached to the leg plate 18, and a sensing lever 50 is attached to the head 48 of the inertial weight 46.
The rear ends of are in contact with each other. The sensing lever 50 has a shape bent at two points, is supported by a horizontal pin 52, and is rotatable within a predetermined angle. Sensing lever 5
The tip of the lever is placed near the pawl 32, so that the tip of the lever presses the pawl 32 when the lever turns.

On the other hand, the lower end of the pole 32 (on the side of the leg plate 18) is supported by a bearing 54, as shown in an enlarged view in FIG. As can be seen from the figure, the end surface of the bearing 54 has a cam surface 56 with a part of its periphery inclined, and an axis-perpendicular surface 36A formed at the axial end of the pawl 36 is in contact with this cam surface 56. . Therefore, when no external force is applied to the pawl 32, the pawl 32 moves downward due to its own weight and at the same time rotates along the cam surface 56 by a predetermined angle. Movement of the pole 32 due to its own weight is caused by the cam surface 56
It is regulated by a terminal end portion, that is, a stepped portion 58. The slope of the cam surface 56 must be formed in a direction in which the pawl 36 of the pawl 32 separates from the ratchet teeth 40 of the lock ring 30.

The operating order of the lock mechanism of this embodiment constructed as described above is as follows. In the normal running state of the vehicle, the pole 32 is located downward due to its own weight,
The pawl 36 is in contact with a stepped portion 58 of the bearing 54. That is, the pawls 34, 36 and the ratchet teeth 3 of the locking ring.
8 and 40 are in a non-engaged state. During this time, the inertial weight 46 moves slightly, but it does not cause the sensing lever 50 to rotate.

Next, when acceleration of the vehicle exceeds a predetermined value,
The inertial weight 46 swings greatly and the sensing lever 50 is moved to the first position.
The tip of the sensing lever 50 presses the pole 32 by turning it clockwise in the figure. Therefore, the pawl 32 pivots counterclockwise as shown in FIG.
4 and 36 engage with the ratchet teeth 38 and 40 of the locking wheel to lock the winding shaft 20. At this time, the pawl 36 of the pawl 32 moves obliquely upward on the cam surface 56 of the bearing 54 against its own weight. The above-mentioned inertia lock mechanism 44 is connected to the pawl 32 or the sensing lever 5.
0, and the winding shaft 20 can be locked by the inertia lock mechanism 44.

Although the pressing operation of the sensing lever 50 against the pole 32 is temporary, in the event of a vehicle emergency, a large pulling force is applied to the webbing 22 due to the inertia of the occupant. Therefore, even if the tip of the sensing lever 50 leaves the pole 32, the claw 34 of the pole 32,
36 remains engaged with the ratchet teeth 38, 40 (as shown in FIG. 2).

When the pull-out force of the webbing 22 is removed, the pawl 32 rotates downward under its own weight as shown in FIG. 3, and the pawls 34, 36 are automatically engaged with the ratchet teeth 38, 40. It will be canceled on. Since the pole 32 is generally made of metal, its own weight is large and this release action is performed smoothly. Furthermore, since the bearing 54 is made of resin, the pawl 36
The friction generated between the pole 3 and the cam surface 56 is also small.
It does not interfere with the dissociation of 2.

As described above, according to this embodiment, even when the winding device is attached to the vehicle body in an inclined state, the pole 3
2 can be reliably released from the lock rings 28 and 30 by utilizing their own weight. Furthermore, since the mechanism is simple and the disengagement spring can be omitted, the number of parts can also be reduced.

In the above embodiment, the cam surface 56 is formed on the bearing 54 side of the pawl 32, but the cam surface 62 may be formed on the pawl 60 itself as shown in FIG. In this case, a cam surface 62 is provided on the lower surface of the pole 60, and the pole 60 is supported by a pin 64 or the like that contacts the cam surface 62. It is preferable that the slope of the cam surface 62 is formed so that the pawl 60 can be rotated in the direction in which it is separated from the ratchet teeth 36, as in the previous embodiment, and that a stepped portion 66 for a stopper is provided.

The locking wheel 30 shown in FIG. 4 is of an indirect locking type, unlike the previous embodiment. That is, the lock wheel 30 is configured to rotate following the winding shaft 20, and when the pawl 60 meshes with the lock wheel 30, the lock wheel 30 lags in rotation with respect to the winding shaft.
A locking member rotating with the winding shaft projects and engages with ratchet teeth formed in the frame.

[Effect of idea]

As mentioned above, in the present invention, the pawl and the pawl support part are engaged with each other with a cam, and the pawl is disengaged from the locking wheel by its own weight.
Even if the webbing take-up device is attached to the vehicle body at an angle, the pole can be reliably separated from the lock ring without requiring a return spring.

[Brief explanation of drawings]

Fig. 1 is a front view of a webbing retractor to which the lock mechanism for a webbing retractor of the present invention is applied, Fig. 2 is a sectional view taken along the line shown in Fig. 1, and Fig. 3 is an enlarged perspective view showing the cam mechanism. , FIG. 4 is an enlarged perspective view showing another embodiment. 20... Winding shaft, 22... Webbing, 28,
30... Lock ring, 32, 60... Paul, 46
...Inertia weight, 50... Sensing lever, 54... Bearing, 56... Cam surface.

Claims (1)

[Scope of utility model registration request] The vehicle has a take-up shaft for winding up occupant restraint webbing, and a locking member that prevents rotation of the take-up shaft in the webbing pull-out direction in the event of a vehicle emergency, and the pivot axis of the locking member is inclined with respect to the horizontal line. In the lock mechanism for a webbing retractor, a cam engagement portion is provided between the locking member and a support member that supports the locking member, in which the locking member pivots away from a take-up shaft rotation blocking position under its own weight. A lock mechanism for a webbing retractor, characterized in that it is provided with a lock mechanism for a webbing retractor.