JP3437486B2 - Webbing take-up device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a webbing take-up device, and more particularly to a lock plate for preventing rotation in a webbing pull-out direction and a lock plate for preventing webbing from being pulled out. And a torsion shaft capable of absorbing energy. 2. Description of the Related Art In a webbing take-up device, the rotation of a spool (winding shaft) in a webbing pull-out direction is locked when the vehicle is suddenly decelerated, so that the webbing is not pulled out. As this lock mechanism, a lock plate is disposed near the device frame on one end side of the winding shaft, and when the vehicle is suddenly decelerated, the lock plate is moved and meshes with lock teeth formed on the device frame, In this configuration, the rotation of the spool (winding shaft) in the webbing pull-out direction is prevented. Further, in such a webbing take-up device, when a webbing is pulled out, a predetermined amount of the webbing is pulled out to absorb energy. As this energy absorbing mechanism, for example, there is a structure in which a spool and a torsion shaft are arranged coaxially with the spool. Normally, the spool and the torsion shaft rotate integrally.However, when the rotation of the torsion shaft in the webbing withdrawing direction is prevented during rapid deceleration of the vehicle, the spool is pulled in the webbing withdrawing direction relative to the torsion shaft by the webbing pulling force. At this time, the torsion shaft is twisted to absorb energy, and a predetermined amount of rotation of the spool is allowed. Incidentally, in such a conventional webbing take-up device, in order to prevent the lock plate from rising (defective holding in a direction of detaching from the device frame along the axial direction of the take-up shaft), the take-up shaft is prevented. The notch for holding the lock plate is formed by cutting at the end of the lock plate. Alternatively, in order to prevent the torsion shaft arranged coaxially with the spool (winding shaft) from coming off, the screw is fixed or press-fitted using a screw. For these reasons, the number of parts has to be increased and special parts processing has been required, which has caused a high cost. SUMMARY OF THE INVENTION In view of the above facts, the present invention is to prevent the lock plate from floating to prevent the webbing from rotating in the pulling-out direction and to absorb energy when stopping the webbing from being pulled out. To provide a webbing take-up device capable of preventing the torsion shaft from slipping out without increasing the number of parts or requiring special parts processing, and also preventing dust and the like from entering the inside of the mechanism. It is an object. According to a first aspect of the present invention, there is provided a webbing take-up device comprising: a tubular spool from which a webbing is wound and drawn; and one end of the spool. A lock base provided coaxially with the spool so as to be rotatable relative to the device frame on the side thereof, and being normally rotated integrally with the lock base and engaged with the device frame during rapid deceleration of the vehicle. A lock plate that prevents rotation of the lock base in the webbing pull-out direction, and is provided coaxially with the spool in the spool, and one end is connected to the spool and the other end is connected to the lock base. The spool and the lock base are integrally rotated to prevent the lock base from rotating in the webbing pull-out direction of the lock base. A torsion shaft for rotating the spool relative to the lock base in the webbing pull-out direction while being twisted by the webbing pulling force in a stopped state. A lock plate cover provided with a nut portion, a hook portion to which the lock base is locked, and an outer peripheral flange portion overlapping the frame; and the device frame is formed by the lock plate cover and the spool. The lock base and the lock plate are covered by being sandwiched. In the webbing take-up device according to the first aspect,
The spool and the lock base are connected via a torsion shaft. Normally, they rotate together and the webbing can be freely pulled out and taken up. For example, at the time of rapid deceleration of the vehicle, the lock plate is engaged with the device frame, thereby preventing the lock base from rotating in the webbing pull-out direction. At this time, the webbing tensile force acts on the torsion shaft via the spool as a rotational force in the webbing pull-out direction. For this reason, the spool is rotated in the webbing pull-out direction with respect to the lock base while the torsion shaft is twisted, and the webbing is pulled out, thereby achieving energy absorption. Here, since the tip of the torsion shaft is locked to the push nut of the lock plate cover, the torsion shaft is prevented from coming off. In addition, since the lock base is locked to the lock plate cover by the hook portion, the lock plate held by the lock base is substantially covered by the lock plate cover, thereby preventing the lock plate from floating. Is done. Further, since the outer peripheral flange portion of the lock plate cover overlaps with the device frame, it is possible to prevent dust and the like from entering the inside of the mechanism. Further, since the lock base and the lock plate are covered with the device frame sandwiched between the lock plate cover and the spool as described above, the lock base and the lock plate, the spool and the tip of the torsion shaft, etc. The shaft portion is prevented from falling off from the device frame. As described above, the webbing take-up device according to the present embodiment can prevent the lock plate from rising to prevent the webbing from rotating in the pulling-out direction and can absorb energy when stopping the webbing from being pulled out. The prevention of the torsion shaft from coming off can be realized by providing a single lock plate cover, so that the number of components is reduced and no special component processing is required. Further, it is also possible to prevent dust and the like from entering the inside of the mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A webbing take-up device 10 according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a webbing take-up device 10 is provided.
Has a frame 11. The frame 11 includes a pair of leg pieces 12 and 14 facing each other in the vehicle front-rear direction, and a leg piece 1.
It is formed in a U-shape with a back piece 16 between 2 and 14. The back piece 16 extends downward, and its lower end is fixed to the vehicle body by bolts. Between the leg pieces 12 and 14 of the frame 11, there is provided a cylindrical spool 22 whose axial direction is the direction opposite to the leg pieces 12 and 14. One end of the webbing 24 is locked to the spool 22, and the rotation of the spool 22 allows the webbing 24 to be drawn out and wound around the spool 22. A lock base 28 is disposed inside the cylinder of the spool 22 at the end on the leg piece 12 side. As shown in detail in FIG. 2, the lock base 28 is rotatably supported coaxially with the spool 22 in the opening of the leg piece 12, and further, as shown in FIG. A lock plate 44 constituting the lock means is held so as to protrude in the radial direction. A pin 45 is formed on the lock plate 44. The lock base 28 has a spool 2
2, a torsion shaft 32 disposed at the axial center of the cylinder
Are connected to each other, and the lock base 28 is configured to always rotate integrally with one end of the torsion shaft 32. Further, one end of the torsion shaft 32 projects outward from the lock base 28 (leg piece 12), and a lock plate cover 48 is further attached. As shown in detail in FIGS. 3 to 5, the lock plate cover 48 is formed in a disk shape as a whole.
Push nut part 5 is cut and raised in the center part
0 is formed. This push nut portion 50 is locked to the tip of the torsion shaft 32. Also,
A pair of hooks 52 extend from the periphery of the lock plate cover 48 so as to face each other. These hooks 52
Are locked by locking protrusions 29 provided on the lock base 28. That is, the lock plate cover 48
The push nut portion 50 is locked to the torsion shaft 32, and the hook portion 52 is locked to the locking projection 29 of the lock base 28, so that the lock base 28 and the lock plate 44 are covered and attached. Have been. Further, an outer peripheral flange portion 54 is provided on the outer peripheral edge of the lock plate cover 48. The outer peripheral flange portion 54 overlaps the leg piece 12.
That is, the lock plate cover 48 covers the lock base 28 and the lock plate 44 with the leg piece 12 sandwiched by the spool 22. A V is provided on the side of the lock plate cover 48.
A gear 42 is provided. The V gear 42 is connected to the torsion shaft 32 protruding from the distal end of the lock base 28.
(In other words, it is supported by the push nut portion 50 of the lock plate cover 48). This V gear 42
Is rotatable relative to the lock base 28. As shown in FIG. 6, the V gear 42 is provided with a pin groove 46 into which a pin 45 formed on the lock plate 44 is fitted. Due to the relative rotation of the V gear 42 in the webbing pull-out direction with respect to the lock base 28, the pin 45
6, and the lock plate 44 is moved in the radially expanding direction. A lock claw 6 is provided at the outer end of the lock plate 44.
6 are formed, and further, on the leg piece 12 facing the lock claw 66, a lock tooth 64 serving as an internal tooth forming a lock means is formed. The lock pawl 66 meshes with the lock teeth 64 by the movement of the lock plate 44 in the radially expanding direction, and the rotation of the lock base 28 in the webbing pull-out direction is prevented. A compression coil spring (not shown) is disposed between the lock base 28 and the V gear 42. The compression coil spring rotates the V gear 42 integrally with the lock base 28. It is energizing. On the outer periphery of the V gear 42, V teeth 5 which are external teeth
6, and below the V gear 42,
An acceleration sensor (not shown) is provided to face the V tooth 56. When the inertial ball receives acceleration due to rapid deceleration of the vehicle and inertially moves forward of the vehicle, the acceleration sensor
The pawl rotates and meshes with the V tooth 56 of the V gear 42, so that the rotation of the V gear 42 in the webbing pull-out direction can be prevented. On the other hand, a sleeve 30 is arranged in the end of the spool 22 on the leg piece 14 side (end opposite to the lock base 28). The sleeve 30 is integrally connected to the spool 22 by fitting spline-shaped teeth, and is rotatably supported coaxially with the spool 22 by the leg pieces 14. The tip of the sleeve 30 is a leg piece 1
4 is projected outward, and a spring spring (not shown) is provided at the projecting end. Thus, the sleeve 30 is constantly urged to rotate in the webin winding direction. Further, the sleeve 30 is connected to the lock base 28 by the torsion shaft 32 described above. Thereby, normally, the spool 22, the sleeve 30, the torsion shaft 32, and the lock base 28 are configured to rotate integrally. Next, the operation of the present embodiment will be described. In the webbing take-up device 10 having the above structure,
The spool 22 and the lock base 28 are connected by a torsion shaft 32. Normally, they rotate together and the webbing 24 can be freely drawn and wound. At the time of rapid deceleration of the vehicle, the lock means including the lock plate 44 and the lock teeth 64 prevents the lock base 28 from rotating in the webbing pull-out direction. At this time, the webbing tensile force acts on the torsion shaft 32 via the spool 22 and the sleeve 30 as a rotational force in the webbing pull-out direction. Therefore, the spool 22 is rotated in the webbing withdrawing direction with respect to the lock base 28 while the torsion shaft 32 is twisted, and the webbing 24 is pulled out, so that energy is absorbed. Here, since the torsion shaft 32 has its tip end locked to the push nut portion 50 of the lock plate cover 48, the torsion shaft 3
2 is prevented. Also, lock plate cover 4
Since the lock base 28 is locked to the lock base 28 by the hook portion 52, the lock plate 44 held by the lock base 28 is substantially a lock plate cover 48.
The lock plate 44 is prevented from floating. Further, the lock plate cover 48
The outer peripheral flange portion 54 overlaps with the leg piece 12, so that dust and the like are prevented from entering the inside of the mechanism. Further, since the lock base 28 and the lock plate 44 are covered with the leg piece 12 sandwiched between the lock plate cover 48 and the spool 22 in this manner, the lock base 28, the lock plate 44 and the spool 22 are covered. Also, the shaft portion including the tip portion of the torsion shaft 32 is prevented from falling off from the leg piece 12. As described above, the webbing take-up device 10 according to the present embodiment prevents the lock plate 44 from lifting up to prevent rotation in the webbing pull-out direction, and absorbs energy when blocking the webbing 24 from being pulled out. To prevent the torsion shaft 32 from coming off.
This can be realized by providing a single lock plate cover 48, the number of components is reduced, and no special component processing is required. Further, it is also possible to prevent dust and the like from entering the inside of the mechanism. As described above, the webbing take-up device according to the present invention prevents the lock plate from rising to prevent the webbing from rotating in the pulling-out direction, and absorbs energy when stopping the webbing from being pulled out. The torsion shaft can be prevented from coming off without increasing the number of parts or requiring special parts processing. In addition, it has an excellent effect of preventing dust and the like from entering the inside of the mechanism. ing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a configuration of a webbing take-up device according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view showing details around a lock base and a lock plate cover of the webbing take-up device according to the embodiment of the present invention. FIG. 3 is a plan view of a lock plate cover of the webbing take-up device according to the embodiment of the present invention. FIG. 4 is a front view of a lock plate cover of the webbing take-up device according to the embodiment of the present invention. FIG. 5 is a cross-sectional view of a lock plate cover of the webbing take-up device according to the embodiment of the present invention. FIG. 6 shows details around a lock base and a lock plate of the webbing take-up device according to the embodiment of the present invention;
It is a side view in the state where a lock plate cover was removed. DESCRIPTION OF SYMBOLS 10 Webbing take-up device 12 Leg piece (device frame) 22 Spool 24 Webbing 28 Lock base 30 Sleeve 32 Torsion shaft 44 Lock plate 48 Lock plate cover 50 Push nut portion 52 Hook portion 54 Outer flange portion

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-119719 (JP, A) JP-A-11-59330 (JP, A) JP-A-9-277904 (JP, A) 246303 (JP, A) JP-A-7-251710 (JP, A) JP-A-8-72671 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60R 22/28 B60R 22 / 38

Claims (1)

(1) A cylindrical spool from which the webbing is wound and drawn, and a coaxially rotatable relative to the spool near an apparatus frame at one end of the spool. A lock base that is held by the lock base and that normally rotates together and engages with the device frame during rapid deceleration of the vehicle to prevent the lock base from rotating in the webbing pull-out direction; The spool is provided coaxially, and one end is connected to the spool and the other end is connected to the lock base. Usually, the spool and the lock base are integrally rotated, and the lock by the lock plate is used. In the state where the rotation of the base in the webbing pull-out direction is blocked, the spool is locked by the lock base while being twisted by the webbing pulling force. And a torsion shaft for rotating the torsion shaft relative to the webbing withdrawal direction. A webbing take-up device comprising: a push nut portion for locking a tip portion of the torsion shaft; and a hook portion for locking the lock base. And a lock plate cover provided with an outer peripheral flange portion overlapping the frame, wherein the lock base cover and the lock plate are covered by sandwiching the device frame between the lock plate cover and the spool. Webbing take-up device.