JPH0532268B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to a retractor for a seat belt for an automobile, and particularly relates to a retractor for a seat belt for a vehicle, and particularly for retracting the position and posture of the seat of the wearer while the seat belt is being worn.
This invention relates to a self-locking belt retractor that automatically locks in a position that suits your body shape.

Prior Art and its Problems Many seat belts installed in automobiles are automatically retracted into a retractor and stored so as not to get in the way when not in use.

Most commonly used retractors do not have a locking mechanism, but when using these retractors, it is necessary to fully pull out the belt. It is necessary to adjust the length of the belt each time depending on the body shape, etc.

In addition, so-called emergency lock retractors are known that lock only when an accident occurs, sudden braking, or a sharp turn, but they have a complicated structure and the reliability of the locking mechanism is not always guaranteed. I couldn't say it was enough. Moreover, when installing a child's seat, the seat must always be securely fixed, but the emergency locking retractor cannot be used for the purpose of fixing this.

Furthermore, various types of specific structures of self-locking retractors similar to the present invention have been proposed. Many of these devices disable the locking mechanism in the initial state when the belt is wound.
The locking mechanism is maintained in the inoperative state while the belt is being pulled out from the retractor to put on the belt, and by retracting the belt slightly after the belt is put on, the locking mechanism is automatically moved to the operating position, and when the belt is pulled out again. A locking mechanism is activated to prevent belt withdrawal.

For example, many devices, including Japanese Patent Publication No. 44-5009, detect the winding diameter of the belt around the retractor in the initial state and set the lock mechanism to a non-operating state. However, the winding diameter of the belt may vary slightly depending on the winding state when the belt was wound after the previous use, and there is a drawback that the accuracy of setting the initial state is poor. Also, many of the conventional examples are
A part of the lock mechanism is exposed at the belt winding part of the belt winding shaft, and the lock mechanism may malfunction due to rust or foreign matter, or the operation of pulling out or retracting the belt may interfere with the operation of the lock mechanism. May cause adverse effects.

Purpose of the Invention The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an automatic locking retractor with good initial state setting accuracy and to ensure that the locking mechanism always operates reliably. It is something to do.

Configuration of the Invention The configuration of the present invention is as follows. That is, the overall structure includes a retractor body, a winding shaft that is rotatably supported on the retractor body and has a belt wound around its outer periphery, and a winding shaft that rotates in the belt winding direction. This self-locking seat belt retractor is equipped with a spring that applies force and a locking mechanism that prevents rotation of the take-up shaft in the direction of pulling out the belt after the belt is pulled out to use.

The structure of the lock mechanism according to the present invention is as shown below. That is, a locking ring having a recess formed in its inner periphery is fixed to the side surface of the retractor main body. A spindle is fixed to one end of the winding shaft, the spindle is fitted into the locking ring, and external teeth are carved on the outer periphery. A locking roller is fitted into the recess of the locking ring, and is movable between an engaged position and a non-engaged position with respect to the external teeth of the spindle.

A clutch is fitted to a side surface of the locking ring so as to be rotatable with respect to the winding shaft,
The clutch is always biased in the belt winding direction with respect to the retractor body, and the clutch has an elongated hole into which the locking roller is slidably fitted in the direction of engagement and disengagement with the external teeth of the spindle. It is perforated. When the clutch rotates relative to the retractor body in the direction of belt withdrawal, the elongated hole causes the locking roller to slide in the direction of engagement with the external teeth of the spindle.

A ratchet boss is integrally fixed to the take-up shaft, and ratchet teeth are formed on the outer periphery of the ratchet boss to engage in the direction in which the belt is pulled out.

A stopper lever is rotatably supported on a side surface of the outer periphery of the clutch. A pawl that can engage with the ratchet teeth of the ratchet boss is formed at the tip of the stopper lever, and the pawl is biased in a direction so as to engage the ratchet teeth.

Further, a friction spring having stopper portions formed at both ends of the ratchet boss is frictionally engaged with the ratchet boss. One stopper part of the friction spring is adapted to bias the stopper lever to a non-engaging position with respect to the ratchet teeth when rotating in the belt winding direction, and the other stopper part is adapted to bias the stopper lever to a non-engaging position with respect to the ratchet teeth. The stopper lever, which is in the non-engaging position with respect to the ratchet teeth when rotated to , is held in the non-engaging position.

Further, a cam member is fitted to the ratchet boss via a speed reduction mechanism, and a cam projection is formed on the outer periphery of the cam member to hold the stopper lever in a position in which it is not engaged with the ratchet teeth. .

Effect of the Invention In the present invention, in the initial state, the cam protrusion of the cam member holds the stopper lever in a non-engaging position with respect to the ratchet teeth of the ratchet boss, and the take-up shaft freely rotates to remove the belt. can be extracted. When the belt is pulled out, the cam member rotates at a reduced speed due to the rotation of the take-up shaft, and the stopper lever is released from being held by the cam protrusion, but the other stopper portion of the friction spring moves the stopper lever against the ratchet teeth. The belt can be pulled out while maintaining the belt in the disengaged position.

Next, by pulling out the belt and winding up the excess belt, the other stopper section is disengaged from the stopper lever and the stopper lever moves to the engagement position with the ratchet teeth, but the rotation direction of the ratchet boss is Since this is the direction in which the ratchet teeth are not engaged, it is possible to wind the belt.

When the belt is pulled out again, the stopper lever engages with the ratchet teeth of the ratchet boss, and the ratchet boss rotates the clutch via the stopper lever. As a result, the elongated hole of the clutch moves the locking roller to the engagement position with the spindle, and the locking ring and the spindle engage with each other via the locking roller, thereby locking the rotation of the winding shaft in the belt withdrawal direction. .

When the belt is unworn and wound onto the take-up shaft, one of the stopper portions of the friction spring biases the stopper lever into a non-engaging position with respect to the ratchet teeth. Then, the cam member is decelerated and rotates, holding the stopper lever in the non-engaging position and returning to the initial state.

Configuration of the embodiment In the drawings, 1 is a retractor main body,
It is composed of a bottom plate 1a and side plates 1b and 1c that stand opposite to each other on both side edges of the bottom plate 1a, and has a substantially channel-like shape. Bolt holes 1d for mounting are bored in the bottom plate 1a, and shaft support holes 1e, 1e are provided in the center of the side plates 1b, 1c.
1f is drilled. A plate 2 is fixed to the outer surface of the side plate 1b, and the plate 2
A spring receiver 2b is integrally protruded from the upper part of the outer surface of the spring holder 2 through a support plate 2a. Further, a through hole 2c is bored in the center of the plate 2, and a bushing portion 2d is protruded from the inner surface of the periphery of the through hole 2c.

Reference numeral 3 denotes a winding shaft, in the center of which a belt winding part 3a is formed, around which the belt A is wound. Further, this winding shaft 3 is connected to shaft support holes 1e and 1f of the side plate 1b and side plate 1c of the retractor main body 1 through the through hole 2c of the plate 2 and the bearing bush 4 at both ends.
It is rotatably supported on the shaft.

One end of the winding shaft 3 passes through the through hole 2c of the plate 2 and protrudes outward from the plate 2, and a spindle 5 having external teeth 5a carved on the outer periphery is integrally attached to the end. Fixed. The end of the winding shaft 3 further protrudes from the spindle 5 to form a fitting part 3b, and a notch 3c is formed at the tip of the fitting part 3b.

The other end of the winding shaft 3 protrudes outward from the side plate 1c of the retractor main body 1, and a groove 3e is formed at the base of the protrusion 3d, and a chamfer 3f is formed at the tip thereof. has been done. An E-ring 6 is fitted into the groove 3e to prevent the take-up shaft 3 from coming off, and a seat spring 7 is fitted into the protrusion 3d, and the groove 3f and the spring cover are fitted together. A full-length spring 9 is interposed between the belt and the belt 8, and the full-length spring 9 applies a rotational force to the winding shaft 3 in the belt winding direction.

A lock mechanism 10 is provided on the outer side of the side plate 1b. In the locking mechanism 10, 11 is a locking ring. The locking ring 11
A recessed portion 11a is formed on the outer periphery of the recessed portion 1.
A support plate 2a of the plate 2 is erected through 1a.

Two recesses 11b are formed at opposing positions on the inner circumference of the locking ring 11.
A guide edge 11c that is inclined with respect to the circumferential direction is formed from the innermost part of 1b toward the belt pull-out direction. On the other hand, on the plate 2, at a position corresponding to the recess 11b of the locking ring 11,
A diagonal long hole 2e is bored along the guide edge 11c. Further, 2f is a restraining piece erected on the plate 2 at the end of the elongated hole 2e within the recess 11b.

The spindle 5 of the winding shaft 3 is
It fits into the locking ring 11. Reference numeral 12 is a cylindrical locking roller, and a short columnar head 12a with a small diameter is protruded from the top thereof. The locking roller 12 is fitted into the recess 11b of the locking ring 11, and its bottom portion can slide along the elongated hole 2e of the plate 2.

In the state in which the locking roller 12 moves in the belt drawing direction, the locking roller 12 engages the external teeth 5 of the spindle 5.
a, and is sandwiched between the external teeth 5a and the guide edge 11c of the locking ring 11, thereby preventing rotation of the spindle 5 in the direction in which the belt is pulled out. On the other hand, when the locking roller 12 is rotated in the belt winding direction, the locking roller 12 is located at the innermost part of the recess 11b, and the locking roller 12 is disengaged from the external teeth 5a.

Reference numeral 13 denotes a plate-shaped clutch, which is rotatably fitted to the fitting portion 3b of the winding shaft 3 on the outer surface of the locking ring 11. Two elongated holes 13a are bored in the clutch 13 at positions facing each other, and the elongated holes 13a
3a is the head 12a of the locking roller 12.
are slidably fitted.

A notch 13b is formed on the outer periphery of the clutch 13, and the support plate 2a and spring receiver 2b of the plate 2 are fitted into the notch 13b. A small protrusion 13c is projected from the outer surface of the clutch 13 on one side of the notch 13b, and a stopper lever 14 is rotatably supported on the small protrusion 13c. . The stopper lever 14
is rotatably supported by the small protrusion 13c at its base 14a, and has a claw 14b and a restraining protrusion 14c at its tip. The restraining protrusion 14c
protrudes outward from the claw 14b, is formed in a box shape with an open end, and has a cavity 14d inside.

Therefore, the base 14a of this stopper lever 14
A helical spring 15 is interposed between the spring receiver 2b of the plate 2, and the helical spring 15 biases the stopper lever 14 so that its tip is directed toward the center of the clutch 13. In addition, the clutch 13 is biased in a direction that rotates in the belt winding direction with respect to the retractor body 1.

Reference numeral 16 denotes a ratchet boss, which is formed in four steps and is connected to the fitting portion 3 of the winding shaft 3.
b, and the winding shaft 3 is attached to the winding shaft 3 by the notch 3c.
It is fixed so that it rotates integrally with the The first step portion 16a and the second step portion 1 of the ratchet boss 16
6b and the third step portion 16c are the winding shaft 3.
The fourth step portion 16d is formed at an eccentric position of the third step portion 16c.

Ratchet teeth 16e are formed on the outer periphery of the first step portion 16a.
The claw 14b of the stopper lever 14 can be engaged with the stopper lever 14. Further, a groove 16f is formed on the outer periphery of the second step portion 16b, and the groove 16f
A friction spring 17 is fitted therein, and is engaged to follow the ratchet boss 16 by frictional force.

The friction spring 17 is formed by bending a wire, and includes an annular fitting portion 17a that fits into the groove 16f, and stoppers bent outward at both ends of the fitting portion 17a. Part 17b,
7c, one of which is the stopper part 17c.
A locking portion 17d is bent and formed at the tip.

A cam member 18 is fitted into the third step portion 16c of the ratchet boss 16 so as to be rotatable relative to the ratchet boss 16. The cam member 18 is
An annular projection 18b is provided on the outer periphery of the disc-shaped plate portion 18a, and a cam projection 18c is provided on the outer periphery of the annular projection 18b. Internal teeth 18d are formed around the periphery.

Furthermore, the fourth step portion 16d of the ratchet boss 16
An external gear 19 is rotatably fitted to the four-step portion 16d. External teeth 19a are formed on the outer periphery of the external gear 19, and the cam member 1
It meshes with the inner teeth 18d of No. 8, and three small protrusions 19b are protruded from the outer surface. On the other hand, in the center of the inner surface of the cover 20 covering the lock mechanism 10, three recesses 20a, which are sufficiently larger than the small protrusions 19b of the external gear 19, are formed at positions corresponding to the small protrusions 19b of the external gear 19. The small protrusions 19b are loosely fitted into the recesses 20a.

21 is a retractor boot that covers the retractor.

Operation of the Embodiment Figures 2 and 3 show the initial state of this embodiment, with the belt fully wrapped. In the initial state, the stopper lever 14 has the restraining protrusion 14c in contact with the outer edge of the cam protrusion 18c of the cam member 18, and the pawl 14b is not engaged with the ratchet tooth 16e of the ratchet boss 16. in position. In addition, the clutch 13 has a spiral spring 15
The locking roller 12 is rotated in the belt winding direction by the elasticity of the clutch 1.
The locking ring 11 slides along the long hole 2e of the plate 2 through the long hole 13a of the locking ring 11.
It is located at the innermost part of b. Locking roller 12 is therefore not engaged with spindle 5.

First, when belt A is pulled out to put on the seat belt, the winding shaft 3 around which belt A is wound
rotates in the belt pulling direction (counterclockwise in the drawing) while tightening the full spring 9. As a result, the spindle 5 and ratchet boss 16 also
It rotates together with the winding shaft 3. Therefore, by rotating the ratchet boss 16,
The friction spring 17 rotates with the ratchet boss 16, and the locking portion 17d at the tip of the stopper portion 17c enters the space 14d of the restraining protrusion 14c of the stopper lever 14, as shown in FIG. do. Thereafter, the friction spring 17 is stopped from rotating by the restraining protrusion 14c, slips between the friction spring 17 and the concave groove 16f of the ratchet boss 16, and is held in a fixed position relative to the retractor body 1.

Further, the fourth step portion 16d of the ratchet boss 16 is eccentric from the central axis of the winding shaft 3, and the external gear 19 is fitted into the fourth step portion 16d. It revolves around the central axis of the shaft 3. However, on the other hand, since the small protrusion 19b of the external gear 19 is loosely fitted into the recess 20a of the cover 20, the external gear 19 is inserted into the retractor body 1.
The external tooth 19 cannot rotate relative to the
a and the internal teeth 18d of the cam member 18 remain in mesh with each other, and the winding shaft 3 only revolves around the central axis. Therefore, while the external gear 19 revolves once, the cam member 18 moves between the internal teeth 18d and the external teeth 19.
The cam member 18 rotates by an angle corresponding to the difference in the number of teeth between the cam member 18 and a (one tooth in the drawing).
are decelerated by the take-up shaft 3 and rotated at low speed in the same direction.

When the belt continues to be pulled out, the cam member 1
8 continues to rotate, and as shown in FIG.
8c is pulled out from the position of the restraining protrusion 14c. However, since the locking portion 17d of the friction spring 17 enters into the space 4d of the restraining protrusion 14c, the stopper lever 14 does not rotate due to being supported by the locking portion 17d. Claw 14d
is held in a non-engaging position with respect to the ratchet teeth 16e of the ratchet boss 16. Therefore belt A
You can freely pull it out to the wearing state.

Next, when the excess belt is wound in after the belt is worn, the winding shaft 3 is moved by the elasticity of the spring 9.
Rotates in the belt winding direction (clockwise in the drawing). As a result, the ratchet boss 16 also rotates together with the take-up shaft 3, and the friction spring 17 is rotated along with the ratchet boss 16.
also rotate in the same direction. Therefore, the locking part 17d is pulled out from the space 14d of the restraining protrusion 14c, and as shown in FIG. The pawl 14b of the stopper lever 14 engages the ratchet tooth 1 of the ratchet boss 16.
6e to the engagement position. Thereafter, as the ratchet boss 21d further rotates in the winding direction, the friction spring 17 moves the stopper portion 17d to the restraining protrusion 14 of the stopper lever 14.
c, and the restraining protrusion 14c is brought into contact with the stopper part 17.
d in the radial direction, the stopper lever 14 is rotated counterclockwise, and the pawl 14b of the stopper lever 14 is moved to the non-engaging position with respect to the ratchet tooth 16e of the ratchet boss 16. The rotation of the stopper lever 14 is stopped when its end surface comes into contact with the inner surface of the cover 20, and the rotation of the friction spring 17 is also stopped at that position.

Next, when a pull-out force is applied to the belt A, the take-up shaft 3 first rotates in the belt pull-out direction (counterclockwise in the figure), and the ratchet boss 16 also rotates together with the take-up shaft 3. The friction spring 17 also rotates in the same direction, and the stopper portion 17
c comes into contact with the restraining protrusion 14c of the stopper lever 14 and is stopped. Also Ratchet Boss 1
The ratchet tooth 16e of No. 6 is connected to the stopper lever 1.
4, the ratchet boss 16
The rotational force pushes the pawl 14b and the stopper lever 1
4, the clutch 13 is rotated in the same direction against the elasticity of the helical spring 15.

When clutch 3 rotates in the belt pulling direction,
The long hole 13a pushes the locking roller 12 and moves it in the same direction. Therefore, the locking roller 12 locks the locking ring 1 as shown in FIG.
1 and the long hole 2e of the plate 2, and its head 12a moves along the long hole 13a of the plate 2.
As shown in FIG. and the spindle 5 are engaged with each other via the locking roller 12. Therefore, the locking mechanism 10 locks and the spindle 5
The rotation of the belt A is blocked, the take-up shaft 3 cannot rotate any further, and the drawing of the belt A is stopped.

When the pull-out force of the belt A is removed, the elasticity of the spring 9 generates a rotational force in the belt winding direction on the winding shaft 3. Therefore, the rotational force is applied to the spindle 5.
Due to the rotational force of the spindle 5 and the rotational force of the clutch 13 due to the elasticity of the helical spring 15, the locking roller 12 is moved between the guide edge 11c of the locking ring 11 and the elongated hole 2 of the plate 2.
e, it moves to the innermost part of the recess 11b and moves to a non-engaging position with respect to the external teeth 5a of the spindle 5. On the other hand, the clutch 13 also rotates in the belt winding direction due to the elasticity of the helical spring 15, and returns to the state shown in FIG. 6 again.

Unfasten the seat belt and retract belt A into the retractor.
6 also rotates together with the winding shaft 3, and the friction spring 17 also rotates in the same direction as the ratchet boss 16 rotates. By rotating in the winding direction, the stopper 17b of the friction spring 17 comes into contact with the restraining protrusion 14c of the stopper lever 14, and the restraining protrusion 14c pushes out the stopper 14 in the radial direction along the stopper part 17b, causing the stopper 14 to rebound. Rotate clockwise to move the pawl 14b of the stopper lever 14 to a position where it does not engage with the ratchet teeth 16e of the ratchet boss 16. The rotation of the stopper lever 14 is stopped when its end surface comes into contact with the inner surface of the cover 20, and when the rotation of the stopper lever 14 is stopped, the rotation of the friction spring 17 is also stopped at that position. .

On the other hand, the cam member 18 is decelerated and rotates in the winding direction at a low speed, and when the winding shaft 3 rotates until the belt A is wound up by a predetermined amount, the cam protrusion 18c of the cam member 18 stops the stopper lever 14. When the belt A reaches the position of the protrusion 14c, the belt A is completely wrapped around the retractor, resulting in the state shown in FIGS. 2 and 3, and returns to the initial state.

Effects of the Invention In the present invention, when the belt A is pulled out and worn, the retractor is reliably locked, and even if a pulling force is applied to the belt A, the retractor is not pulled out, and the length of the belt is You can always wear your seat belt under the correct wearing condition without having to adjust it.

Further, in the retractor of the present invention, since the initial state is set by the cam protrusion 18c of the cam member 18, the accuracy of the initial state is good. In addition, the locking mechanism is all attached to the cover 20 at the end of the retractor.
This is a safe and reliable automatic locking seatbelt retractor, as the locking mechanism is stored inside the seat, so the locking mechanism does not malfunction due to rust or foreign matter, and the belt does not have any negative effect on the locking mechanism. It becomes.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a central vertical cross-sectional view, and FIG. 2 is a view of the initial state -
3 is a cross-sectional view of the initial state. Figures 4 to 7 show the process of operation-
FIG. 4 shows a state where the belt is pulled out a little, FIG. 5 shows a state where the belt is pulled out a lot, and FIG.
FIG. 6 shows a state in which the belt has been pulled out and then wound into the retractor, and FIG. 7 shows a state in which a pulling force is applied to the belt again. FIG. 8 is a cross-sectional view of the same state as FIG. 7. A... Belt, 1... Retractor body, 3...
...Take-up shaft, 5...Spindle, 5a...External teeth, 9...Full spring, 10...Lock mechanism, 11
... Locking ring, 11b ... Recess, 12 ...
...Locking roller, 13...Clutch, 13
a... Long hole, 14... Stopper lever, 14b
...Claw, 16...Ratchet boss, 16e...Ratchet tooth, 17...Friction spring,
17b, 17c...stopper part, 18...cam member, 18c...cam protrusion, 18d...inner tooth, 1
9... External gear, 19a... External tooth.

Claims (1)

[Claims] 1. A retractor body 1, a winding shaft 3 that is rotatably supported on the retractor body 1 and around which the belt A is wound, and a rotational force applied to the winding shaft 3 in the belt winding direction. and a lock mechanism 10 provided at one end of the take-up shaft 3 to prevent rotation of the take-up shaft 3 in the belt pulling-out direction after the belt A is pulled out to use. In the automatic locking seat belt retractor, the locking mechanism 1
0 is fixed to the side surface of the retractor main body 1 and has a recess 11b formed on its inner periphery, and a locking ring 11 that is integrally fixed to one end of the winding shaft 3 and is fitted into the locking ring 11. A spindle 5 that is fitted together and has external teeth 5a carved on its outer periphery.
, a locking roller 12 that is fitted into the recess 11b of the locking ring 11 and can move between an engaging position and a non-engaging position with respect to the external teeth 5a of the spindle 5; and a side surface of the locking ring 11. a clutch 13 rotatably fitted to the winding shaft 3 and always biased in the belt winding direction with respect to the retractor main body 1;
The locking roller 12 is drilled in the clutch 13 and is slidably fitted in the direction of engagement and disengagement with the external teeth 5a of the spindle 5, and the clutch 13 is fitted in the direction of belt withdrawal with respect to the retractor body 1. Locking roller 1 by rotating
2, and a ratchet tooth 16e that is integrally fixed to the winding shaft 3 and that engages with the outer periphery of the winding shaft 3 in the direction in which the belt A is pulled out. The clutch 13 has a ratchet boss 16 which is rotatably supported on the side surface of the outer circumference of the clutch 13, and has a pawl 14b at its tip that can engage with the ratchet teeth 16e of the ratchet boss 16. The stopper lever 14 is biased in the direction of engaging with the ratchet tooth 16e, and the stopper lever 14 is frictionally engaged with the ratchet boss 16, and has its both ends disengaged from the ratchet tooth 16e when the stopper lever 14 rotates in the belt winding direction. A friction member formed with a stopper portion 17b that biases the belt to a position, and a stopper portion 17c that holds the stopper lever 14, which is in a non-engaging position with respect to the ratchet teeth 16e, in the non-engaging position when rotating in the belt withdrawal direction. The spring 17 decelerates and transmits the rotation of the take-up shaft 3, and when the belt A is wound around the take-up shaft 3 by a predetermined amount, the stopper lever 14 is moved to the ratchet tooth 16.
cam protrusion 18c held in a non-engaging position with respect to e;
A retractor for an automatic locking seatbelt, characterized by a cam member 18 having a cam member formed on the outer periphery.