JPH035486Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of application of the invention] The invention is used in a seat belt device for protecting occupants in vehicle emergencies, and uses a wire spring to apply a predetermined biasing force to a locking ring that is pivotally supported on a webbing take-up shaft. In particular, the present invention relates to a spring mounting structure for a lock ring for rotation following the winding shaft.

[Conventional structure]

In the webbing take-up device, a lock ring is pivotally supported on the webbing take-up shaft so that it can follow and rotate under a predetermined biasing force.In the event of a vehicle emergency, the lock ring is delayed in rotation relative to the take-up shaft, causing the lock to be locked. A device is used to stop the rotation of the take-up shaft for pulling out the webbing.

A torsion coil spring is generally used as a spring to generate a biasing force on this lock ring, and one of the pair of straight parts of this torsion coil spring is locked to the lock ring, and the other is locked to the winding shaft. This causes the lock wheel to rotate following the webbing take-up shaft. This torsion coil spring is made small in order to improve response acceleration, and requires complicated assembly work to ensure accurate installation.

[Purpose of invention]

The object of the present invention is to obtain a spring mounting structure for a lock ring that can limit the mounting position of the torsion coil spring and allow the torsion coil spring to be mounted easily and quickly.

[Summary of the idea]

In the locking ring spring mounting structure according to the present invention, the setting shaft protruding from the locking ring is used for insertion into the coil part of the coil spring, and the cylindrical part coaxially arranged with the setting shaft is arranged outside the coil part. By forming a notch for inserting one straight part of the coil spring in the cylindrical part and a notch for rotating the other straight part of the coil spring within a predetermined angle range on the end face of the cylindrical part. This limits the mounting position of the torsion coil spring, thereby creating a uniform mounting condition and allowing the coil spring to be mounted easily and quickly.

[Example of idea]

FIG. 1 shows the main parts of a webbing retractor to which an embodiment of the present invention is applied.

The webbing take-up shaft 10 is pivotally supported by a frame (not shown), and by attaching this frame to the vehicle body, the winding device is mounted on the vehicle body.

A mounting hole 12 is bored in the winding shaft 10,
One end of the occupant restraint webbing (not shown) is locked so that it can be wound up in layers around the winding shaft 10. The other end of the webbing wound onto the take-up shaft 10 is secured to another vehicle body part via a buckle device or the like, so that the intermediate portion of the webbing can be worn by a passenger.

A support shaft 14 protrudes from one axial end of the winding shaft 10, and a lock ring 16 is attached to the tip of the support shaft 14.
is now pivoted.

A rectangular shaft portion 18 projects from the support shaft 14 in the radial direction. A pair of lock plates 22 having a rectangular groove 20 into which the rectangular shaft portion 18 is inserted rotate together with the winding shaft 10, and in the event of a vehicle emergency, these lock plates 22 move in opposite directions. It is designed to mesh with an internal tooth ratchet foil (not shown). This internal toothed ratchet wheel (not shown) is fixed to the frame, thereby stopping the rotation of the take-up shaft 10 for pulling out the webbing.

A set shaft 24 is arranged at the center of the lock ring 16, and the support shaft 14 is inserted into the center hole of the set shaft 24, so that the lock ring 16 can rotate coaxially with the winding shaft 10. It's becoming like that. A coil portion 26A of the torsion coil spring 26 is inserted into the outer periphery of the set shaft 24, and a cylindrical portion 28 disposed coaxially with the set shaft 24 into the lock ring 16 is inserted into the torsion coil spring coil portion 26A.
is placed outside.

Notches 30 are formed in the cylindrical portion 28 on opposite sides of the axis, and a portion of the cylindrical portion 28 forms an extension portion 32 extending in the tangential direction. A stopper 34 is formed at the end of this extension part 32, and one straight part 26B of the torsion coil spring is formed.
It is designed for contact.

As shown in FIGS. 2 and 3, the cylindrical portion 28 has a large axial height in a predetermined angle area adjacent to the notch 30 when viewed in the axial direction, and has a large height in the axial direction other than this and the extension portion 32. However, due to the notch 36, the shaft dimension is shortened.

As a result, as shown in FIG. 3, the other straight portion 26c of the torsion coil spring becomes
It is designed to reach the outside of the cylindrical portion 28 through this notch 36.

The other straight portion 26c of this torsion coil spring receives a deforming force from a locking protrusion 40 of a holder 38 uniformly attached to the winding shaft support shaft 14 at a predetermined angle, and is applied to the lock ring 16 against the winding shaft. It is designed to generate an urging force in the direction of follow-up rotation.

A pair of lock plates 22 each have a pin 4.
2 protrudes and is inserted into an elongated hole 44 formed in the lock ring 16. As a result, the pair of lock plates 22 are urged in a direction away from the internally toothed ratchet wheel (not shown), but when the lock ring 16 lags in rotation with respect to the winding shaft 10, it is guided into the elongated hole 44. The two wheels move in opposite directions and engage with the internal ratchet wheel.

Further, the lock wheel 16 has a ratchet wheel engraved on its outer periphery, and in the event of a vehicle emergency, the lock wheel 16 engages with an acceleration sensor and is prevented from rotating, so that it rotates relative to the winding shaft 10. Further, in the case of a webbing retractor not provided with an acceleration sensor, the lock ring 16 acts as an inertia plate and causes a rotational delay with respect to the sudden rotation of the webbing shaft 10 to pull out the webbing.

The assembly procedure of this embodiment will be explained.

The winding shaft 10 is pivotally supported on a frame (not shown),
A pair of lock plates are brought into contact with the rectangular shaft portion 18 at the end of the take-up shaft, and a lock ring 1 is attached to the take-up shaft support shaft 14.
6, the torsion coil spring 26 is inserted into the lock ring set shaft 24, and the holder 38 is fixed to the take-up shaft support shaft 14 to complete the assembly.

In this case, the torsion coil spring 26 is
6A to the outer periphery of the set shaft 24, and inserting one straight portion 26B into either one of the pair of notches 30, the other straight portion 26c will move in the tangential direction of the cylindrical portion 28 in correspondence with the notch 36. It will stand out.
As described above, since the torsion coil spring 26 can be attached to the set shaft 24 only in the state shown in FIG. The assembly position is restricted and uniform assembly is possible. The holder 38 can be mounted either as shown in FIG. 2 or on the opposite side of the winding shaft by 180 degrees, and the torsion coil spring 26 can be mounted as shown in FIG. Although it can be installed on the opposite side, the torsion coil spring 2
There is no change in the biasing force of 6.

[Effect of idea]

As explained above, in this invention, the mounting position of the torsion coil spring is limited by the set shaft, cylindrical portion, and notch provided on the lock ring, so it is possible to quickly and accurately assemble the lock ring to the winding shaft. Has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the main parts of a webbing retractor to which an embodiment of the present invention is applied, FIG. 2 is a front view of a lock ring, and FIG. 3 is a cross-sectional view taken along the line shown in FIG. 2. DESCRIPTION OF SYMBOLS 10... Webbing take-up shaft, 16... Lock ring, 24... Set shaft, 26... Torsion coil spring, 28... Cylindrical part, 30... Notch part, 36...
Notch.

Claims (1)

[Scope of utility model registration request] A lock ring spring mounting structure for mounting a lock ring to a winding shaft under a predetermined biasing force, wherein a set shaft is made to protrude from the lock ring for insertion into a coil portion of a coil spring, and the set shaft is inserted into a coil portion of a coil spring. A cylindrical part coaxially arranged with is disposed on the outside of the coil part, and the cylindrical part is formed with a notch for insertion of one straight part of the coil spring, and a cutout part is formed in the cylindrical part at a predetermined position when viewed in the axial direction of the cylindrical part. A spring mounting structure for a lock ring, characterized in that a rotation notch for rotating the other straight portion of the coil spring within an angular range is provided on the end face of the cylindrical portion.