JPH0323401Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a webbing lock device that is used in a seat belt device for protecting an occupant in a vehicle emergency, and that stops pulling out of the webbing for restraining the occupant in a vehicle emergency.

[Background technology and issues to be solved] In a seat belt device, the end of the webbing for restraining an occupant is wound around a take-up shaft in layers, and in the event of a vehicle emergency, an inertia lock mechanism prevents the webbing from being pulled out and rotated from the take-up shaft. The design is such that the vehicle is stopped and the occupant is restrained by the webbing.

In this case, if a large tension is applied to the webbing due to the inertia of the occupant after the rotation of the webbing drawer on the take-up shaft has been stopped, the webbing that is wound in layers around the take-up shaft will be tightened, causing the webbing to stretch. Outflow occurs.

For this reason, conventionally, the middle part of the webbing pulled out from the winding shaft is wound around a rock roller, and the rock roller is moved by the increased tension of the webbing in the event of a vehicle emergency and is pressed against the outer periphery of the layered winding section.
A configuration has been proposed in which the winding tightness in the layered winding portion is thereby eliminated.

However, in such a locking device, when the occupant is wearing the webbing, the layered winding section on the outer periphery of the winding shaft becomes smaller in diameter as the webbing is pulled out. The distance between the webbing becomes wider, and the stroke becomes larger by the length corresponding to the reduction in the webbing take-up diameter before the rock roller comes into contact with the layered take-up part in the event of a vehicle emergency.

The present invention takes the above facts into account, and aims to provide a webbing lock device that can reduce the distance between the rock roller and the outer periphery of the layered winding section even when the occupant is wearing the webbing. .

[Overview and operation of the device]

The present invention is a webbing in which the webbing pulled out from the layered winding section of the winding shaft is wound around the rock roller, and when the winding shaft stops rotating, the tension of the webbing increases and the rock roller is pressed against the outer periphery of the layered winding section. The locking device includes a winding diameter sensing roller that comes into contact with the outer periphery of the layered winding part of the webbing, and a winding diameter sensing roller and the lock roller that are connected to each other and biased in directions to separate from each other. pressing the sensing roller to the outer periphery of the layered winding section and moving the rock roller in a direction approaching the layered winding section in accordance with the reduction in the outer diameter of the webbing layered winding section;
When the tension of the webbing increases, the elastic body is elastically deformed by being pressed by the rock roller to allow the elastic body to be pressed against the outer periphery of the layered winding portion of the rock roller.

According to the above configuration, the elastic body presses the winding diameter sensing roller against the outer periphery of the layered winding section and connects the winding diameter sensing roller and the rock roller while urging them away from each other. As the outer diameter of the layered winding portion of the shaft decreases, the rock roller moves in a direction closer to the layered winding portion, following the movement of the winding diameter sensing roller in the axial direction of the winding shaft. Therefore, the rock roller and the outer periphery of the layered winding section are always arranged close to each other.

When the tension of the webbing increases in this state, the Rotsu crawler around which the webbing is wrapped will
This webbing presses the layered winding portion in a direction approaching it. Therefore, the elastic body itself is elastically deformed by the pressing force of the rock roller. In this way, the rock roller is allowed to press against the outer periphery of the layered winding portion. Here, the female force in the direction of separating the rock roller of the elastic body from the layered winding section is generally extremely small compared to the pressing force of the webbing pressing the rock roller when the webbing tension increases. Therefore, the rock roller directly presses the layered winding portion.

As a result, according to the present invention, in addition to the fact that the rotary roller and the outer periphery of the layered winding section are always arranged close to each other, the rotary roller presses the layered winding section directly, so that the vehicle It is possible to quickly prevent the layered winding portion from tightening in an emergency, and to minimize the extent to which the webbing stretches out.

[Embodiment of the invention] FIG. 1 shows a webbing retractor 10 to which the invention is applied. In this webbing retractor 10, a frame 12 is fixed to a vehicle body 16 with mounting bolts 14.

From both sides of the frame 12, a pair of leg plates 18,
20 protrude parallel to each other, and the winding shaft 22
is pivoted. One end of the occupant restraint webbing 24 is wound around the winding shaft 22 in a layered manner to form a layered winding section 24A, and the tip of the webbing 24 pulled out from the winding shaft 22 is used as a buckling device or the like. The intermediate portion of the webbing 24 is engaged with the webbing 24 so that the occupant can wear it.

A winding shaft 22 protruding from the leg plate 18 is provided with a mainspring spring winding device 26.
is biased and rotated in the winding direction of the webbing 24.

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. This ratchet wheel 28 has a pawl 30 which is pivotally supported on the leg plates 18 and 20.
is compatible. This pawl 30 engages with the ratchet wheel 28 in the event of a vehicle emergency using the driving force of an acceleration sensor 32 attached to the outside of the leg plate 20, and stops the rotation of the webbing pull-out of the take-up shaft 22.

Immediately below the winding shaft 22, a long hole 3 is provided to the leg plates 18, 20.
4 is formed. These long holes 34 are formed so as to extend in the radial direction of the winding shaft 22, and guide the vicinity of both ends of the roller shaft 36. A rock roller 38 is pivotally supported on this roller shaft 36 and is freely rotatable. The outer periphery of the lock roller 38 is a wave-shaped lock surface, and the intermediate portion of the webbing 24 extending from the winding shaft 22 to a mounting portion for an occupant (not shown) is wound around the lock roller 38.

One end of a torsion coil spring 42 is abutted near one end of the roller shaft 36. The leg plates 18 and 20 are connected to the central coil portion of the torsion coil spring 42.
A pin 44 extending across is inserted and supported, and the other end is bent at a right angle and a winding diameter sensing roller 46 is pivotally supported.

Here, the torsion coil spring 42 biases the winding diameter sensing roller 46 and the lock roller 38 in directions away from each other, disposing the roller shaft 36 at one end of the elongated hole 34, and moving the winding diameter sensing roller 46 toward the layered winding section. It is brought into contact with the outer periphery of 24A. However, as shown in FIG. 3, the biasing force of this torsion coil spring 42 is such that when the webbing 24 is pulled out and the outer diameter of the layered winding section 24A is reduced, the winding diameter sensing roller 46 follows this reduction. By moving in the axial direction of the shaft 22 and rotating clockwise about the pin 44 while keeping the included angle between the one end and the other end in contact with the roller shaft 36 constant, The outer periphery of the roller shaft 38 is the layered winding part 2
4A, and the roller 38 and the layered winding portion 24A are designed so that they are always at the same interval.

Next, the operation of this embodiment will be explained.

Normally, the torsion coil spring 42 holds the roller shaft 36 in the lowered position, so when the occupant pulls out the webbing 24, the rock roller 38 is rotated by the frictional force with the webbing 24, and the outer diameter inside the webbing 24 is reduced. Tsuterotsu Crawler 38
rises, and the roller 38 and layered winding section 24A
The distance between them is kept short.

When the vehicle is in an emergency situation such as a collision, the acceleration sensor 32 engages the pawl 30 with the ratchet wheel 28, so that the rotation of the take-up shaft 22 in the webbing pulling direction is stopped.

At the same time, the occupant moving in the direction of acceleration due to inertia applies a large tensile force to the webbing 24. Therefore, this tensile force causes the torsion coil spring 42 to bend against the force, and the rock roller 38 suddenly moves to the outer periphery of the layered winding section 24A, presses the layered winding section 24A, and presses the webbing 24.
This tension is prevented from acting on the layered winding portion 24A. Therefore, even though a large tensile force is acting on the webbing 24, the layered winding portion 24A does not become tightly wound, and the webbing 24 does not extend much.

It goes without saying that other elastic bodies such as compression coil springs may be used in place of the torsion coil springs of the above embodiments.

[Effect of idea]

As explained above, in the webbing lock device according to the present invention, the winding diameter sensing roller and the locking roller are connected to each other and biased in directions away from each other, and the winding diameter sensing roller is pressed toward the outer periphery of the layered winding section. In addition, the rock roller is moved in the direction approaching the layered winding part in accordance with the reduction in the outer diameter of the webbing layered winding part, and when the tension of the webbing increases, it is pressed by the rock roller and elastically deforms, causing the rock roller to move closer to the layered winding part. Since an elastic body is provided that allows pressure on the outer periphery of the layered winding section, even if the winding diameter of the layered winding section decreases as the webbing is pulled out, the rock roller and the outer periphery of the layered winding section are always kept close to each other. It has the excellent effect of being able to directly press the layered winding portion of the rock roller. Furthermore, this effect is extended to the effect that it is possible to quickly prevent the winding of the layered winding portion from tightening in the event of a vehicle emergency, and to minimize the extent of webbing extension.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a webbing retractor to which an embodiment of the webbing lock device according to the present invention is applied, FIG. 2 is a left sectional view of FIG. 1, and FIG. 3 is an operation diagram of FIG. 1. FIG. 4 is an exploded perspective view showing the main parts. DESCRIPTION OF SYMBOLS 10... Webbing winding device, 22... Winding shaft, 24... Webbing, 24A... Layered winding part, 34... Long hole, 36... Roller shaft, 3
8... Rotsu roller, 42... Torsion coil spring, 46... Winding diameter sensing roller.

Claims (1)

[Scope of utility model registration request] The webbing lock device is a webbing lock device in which the webbing pulled out from the layered winding part of the winding shaft is wound around a lock roller, and when the pull-out rotation of the winding shaft is stopped, the rock roller is pressed against the outer periphery of the layered winding part by increasing the tension of the webbing. The winding diameter sensing roller that comes into contact with the outer periphery of the layered winding part of the webbing, and the winding diameter sensing roller and the rock roller are connected to each other and biased in directions away from each other. The lock roller is moved in a direction approaching the layered winding section by pressing it against the outer periphery of the winding section and following the reduction in the outer diameter of the webbing layer winding section, and as the tension of the webbing increases, it is pressed by the lock roller and 1. A webbing lock device comprising: an elastic body that elastically deforms itself to allow pressing against the outer periphery of a layered winding portion of a rock roller.