JPH037237Y2 - - 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 that 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 action of engaging the lock wheel on the pole is performed by the lever of the acceleration sensor, but if this lever cannot be installed at the bottom of the pole due to the structure of the winding device, the lever can be used to directly move the pole in the direction of lock ring engagement. It becomes impossible to press the

[Purpose of invention]

The present invention was devised in view of the above circumstances, and its purpose is to provide a lock for a webbing retractor that allows power transmission between the lever of the acceleration sensor and the lock wheel locking member without any problem even when the operating directions of the lever and the lock wheel locking member are different. The goal is to provide a mechanism.

[Structure of the idea]

In order to achieve the above object, in the present invention, the locking member and the support shaft of the locking member are cam-engaged, and the pressing force of the sensing lever acting on the locking member is converted into a turning force in the direction of lock ring engagement. It is configured so that it can be converted.

[Example of idea]

In the embodiment of the invention shown in FIG. 1, a frame 10 is fixed to the vehicle body by mounting bolts 12. As shown in FIG. A pair of leg plates 1 are attached from both sides of the frame 10.
6 and 18 protrude, and a webbing take-up shaft 20 is pivotally supported between both leg plates 16 and 18.

The winding shaft 20 winds one end of the occupant restraining 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 wound around the end of the winding shaft 20 protruding from the leg plate 18, and the mainspring spring 24 is covered with a spring case 26. This mainspring spring 24 lightly biases the winding shaft 20 in the webbing winding direction.

Further, a lock ring 2 is provided on the leg plate 18 side of the winding shaft 20.
8 is fixed so that it rotates together with the winding shaft 20. A plurality of ratchet teeth 30 are carved on the outer periphery of the lock ring 28, as shown in FIG.
A pawl 32 corresponds to this ratchet tooth 30. The pawl 32 is rotatably attached to a horizontal support shaft 34 protruding from the inner surface of the leg plate 18, and engages with the ratchet teeth 30 of the locking wheel 28 to lock the winding shaft 20 in the event of a vehicle emergency.

As can be seen from FIG. 3, a cam groove 36 is formed on the outer surface of the support shaft 34, and the pole 3 is inserted into this cam groove 36.
A protrusion 38 provided on the inner surface of the hole 2 is fitted. Since the cam groove 36 is provided in a helical shape on the outer surface of the support shaft 34, when an external force in the axial direction is applied to the pawl 32, the pawl 32 moves in the axial direction and rotates by the helical angle of the cam groove 36. Become. Although the tip of the protrusion 38 is curved to allow the pawl 32 to operate smoothly, if the friction with the cam groove 36 is still large, a roller is installed in place of the protrusion 38.

Further, a compression coil spring 40 is wound around the support shaft 34 to bias the pole 32 in the direction in which the support shaft 34 projects. On the other hand, on the opposite side of the pole 32 is a lever 4.
The tips of the poles 2 and 3 are in contact with each other to prevent the pole 32 from moving in the axial direction. As can be seen from FIG. 1, the lever 42 is L-shaped and is attached to the frame 10 at its bent portion so as to be pivotable about a horizontal shaft 43, and its other end abuts against a head 46 of an inertial weight 44. The axis of the horizontal shaft 43 is perpendicular to the support shaft 34. The inertial weight 44 is for sensing acceleration generated in the vehicle, and is swingably supported by the frame 10.

The end of the winding shaft 20 protruding from the leg plate 16 (the first
The device shown in FIG. 1 is covered with a cover 48, and an inertia lock mechanism 50 is housed within the cover 48.
The inertia lock mechanism 50 locks the webbing 22 on the take-up shaft 20 when the webbing 22 is suddenly pulled out from the take-up shaft 20.
0 is locked to prevent the webbing 22 from unwinding. Although this mechanism is well known and its details will be omitted, the inertia lock mechanism 50 may be connected to the lever 42.

The operating sequence of the lock mechanism thus constructed is as follows. Under normal vehicle driving conditions,
The pawl 32 is in a non-engaging position (the position shown in FIGS. 1 and 3) with the ratchet teeth 30 of the lock ring 28 due to the biasing force of the compression coil spring 40. During this time, the inertial weight 44 moves slightly, but does not push up the rear end of the lever 42. Therefore, the webbing 24 worn by the passenger is only lightly stretched by the biasing force of the mainspring spring 24.

Next, when the acceleration of the vehicle exceeds a predetermined value (in an emergency), the inertia weight 44 swings greatly and the lever 42
is rotated clockwise in FIG. 1, and the tip of the lever 42 moves the pole 32 toward the leg plate 18 against the biasing force of the compression coil spring 40. Paul 32
is rotated in the counterclockwise direction in FIGS. 2 and 3 with axial movement by the action of the cam groove 36, and engages with the ratchet teeth 30 of the lock ring 28. This prevents the lock ring 28 and the take-up shaft 20 from rotating clockwise, and the drawing of the webbing 22 is stopped.

Although the pressing operation of the lever 42 against the pole 32 is temporary, in the event of a vehicle emergency, a large tensile force acts on the webbing 22 due to the inertia of the occupant. For this reason, the pole 32 of the lever 42
Even when the pressing force on the pawl 32 is released, the pawl 32 remains engaged with the ratchet teeth 30 as shown in FIG.

When the tensile force of the webbing 22 is removed, the pawl 32 is separated from the ratchet teeth 30 by the biasing force of the compression coil spring 40 and returns to the state shown in FIGS. 1 and 3.

As described above, according to this embodiment, even when the moving directions of the lever 42 and the pawl 32 are different, the power transmission between the lever 42 and the pawl 32 is performed smoothly, and the pawl 32 can be reliably separated from the ratchet teeth 30. There is. Further, even when the winding device is installed on the vehicle body at an angle, the operation of the lock mechanism will not be hindered by simply allowing the inertia weight 44 to hang down in the longitudinal direction.

In this embodiment, the support shaft 34 is provided with a cam groove 36 and the pawl 32 is provided with a protrusion 38, but by increasing the axial dimension of the pawl 32, a cam groove is provided on the inner surface of the hole of the pawl 32, and a protrusion or roller is provided on the support shaft 34. It may be provided.

Although a direct lock type retractor is shown in FIGS. 1 to 3, the lock mechanism for a webbing retractor of the present invention can also be applied to an indirect lock type retractor. In this case, the lock ring rotates following the winding shaft via the spring, and when the rotation of the lock ring is prevented by the pawl, the lock plate engages with the ratchet inner toothed foil fixed to the leg plate. Therefore, the take-up shaft is locked and unwinding of the webbing is stopped.

[Effect of idea]

As mentioned above, in the present invention, a locking member such as a pawl and this support shaft are engaged with each other by a cam, and the pressing force of the sensing lever acting on the locking member can be converted into a turning force in the direction of engaging the lock wheel. With this structure, even if the sensing lever and the locking member operate in different directions, the power can be transmitted between them without any problem.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of a webbing retractor to which the locking 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 a cam mechanism of the pole. FIG. 20... Winding shaft, 22... Webbing, 28...
...Lock ring, 32...Pole, 34...Spindle, 3
6...Cam groove, 38...Protrusion, 40...Compression coil spring, 42...Lever, 44...Inertia weight.

Claims (1)

[Scope of utility model registration request] A take-up shaft for winding up occupant restraint webbing, a locking member that prevents the take-up shaft from rotating in the webbing pull-out direction in the event of a vehicle emergency, and a locking member that is rotated around the take-up shaft to a rotation blocking position in the webbing pull-out direction. A webbing retractor having a support shaft capable of supporting the webbing, an emergency operating means for pressing the locking member to a rotation blocking position in the webbing drawer direction in a vehicle emergency, and a biasing means for disengaging the locking member from the blocking position. In the locking mechanism, the pressing force acting on the locking member provided between the locking member and the support shaft is converted into a turning force to the blocking position, and the locking member prevents the rotation of the take-up shaft in the webbing pull-out direction. A locking mechanism for a webbing take-up device, comprising a cam means for blocking the webbing.