JPS6339155Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seat belt retractor, and particularly to a seat belt retractor with a tensionless mechanism that does not allow an occupant to feel the tension caused by the winding spring of the retractor.

Various seat belt retractors with a tensionless mechanism are known, among which a guide plate with a spiral guide formed on one side is attached to the spool so as to be rotatable integrally with the spool, while the spiral A follower having spring properties is installed in a direction perpendicular to the spiral guide part and in a direction intersecting the spiral winding, and this follower moves along the spiral guide part as the guide plate rotates. At a predetermined position, the follower engages with a locking part provided on the spiral guide to prevent the spool from rotating in the belt winding direction, creating a tensionless system, while allowing the guide plate to rotate in the belt unwinding direction. What you get is known.

By the way, in the case of such a seatbelt retractor with a tensionless mechanism, when the buckle and the tongue are disengaged and the belt is removed to get out of the vehicle, it is desirable to release the above-mentioned memory of the belt tensionless. Therefore, in general, an engagement release means is provided to release the engagement between the follower and the locking portion of the spiral guide portion and the spool when the vehicle exits the vehicle.

As this disengagement means, a means is employed which electrically detects disengagement between the buckle and the tongue and electromagnetically operates a release lever that causes the follower to float.

However, this method uses the retractor's hoisting spring force to raise the locked follower all at once and disengage it, which requires a considerable amount of operating force, and the release lever cannot be moved electromagnetically. In order to operate the device, a high-power electromagnetic actuator is required, which inevitably increases the size of the device.

In view of the conventional situation, it is an object of the present invention to provide a seatbelt retractor with a tensionless mechanism that is equipped with a disengagement means that requires only a small force for disengagement of the follower.

In order to achieve the above object, in the present invention, the disengagement means includes a release lever which is rotatably mounted on the frame and has a wedge-shaped cam portion at its tip having a gentle slope for gradually allowing the follower to ride on it;
The release lever is actuated to cause the cam portion at the tip to enter between the follower and the frame, and when the follower is disengaged, the follower is gradually lifted up by the cam portion having a gentle slope. Therefore, the engagement can be released with a relatively small operating force.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 6, the seatbelt 1 has a loop portion 1a formed at its end that is connected to a long hole 3 of a spool 3.
a, and the shaft 8 is inserted and assembled to the spool 3. Flanges 4 and 5 are integrally formed at both ends of the spool 3, and ratchet teeth 5a are formed on the peripheral edge of one flange 5 to prevent the belt from being pulled out in an emergency by cooperating with an emergency lock mechanism to be described later. There is.

The side surface of the other flange 4 is integrally provided with ratchet teeth 4a on the same predetermined circumference as one of the locking portions that engage with a follower 13, which will be described later, to prevent the spool 3 from rotating in the belt winding direction. It is molded.

A spring 9 is attached to one end of the shaft 8 for biasing the spool 3 in the belt winding direction. 9a
is the same cover.

The frame 2 is formed in a U-shape, and a shaft through hole 2a is formed in a pair of opposing side walls. A follower penetration hole 2b is formed in one side wall so as to be continuous with the shaft through hole 2a, and a follower support pin 2c is provided protruding from the lower side. Also,
A fan-shaped hole 10a for supporting the ratchet pole is provided at the lower side of the other side wall. Further, a bush 15 is fitted into the shaft through hole 2a of the one side wall. 10A shows a known emergency lock mechanism, which includes a pendulum support 11 fixed to the frame 2, a pendulum 12 swingably attached to the support 11, one end supported in the door-shaped hole 10a, and an upper surface of the pendulum 12. The ratchet pole 10 is in contact with the ratchet pole 10. This emergency lock mechanism 10A senses a certain deceleration and acceleration of the vehicle by the swinging of the pendulum 12, and
The rotation of the spool 3 in the belt withdrawal direction is prevented by tilting the ratchet pawl 10 upward by the swinging motion of the belt 2 and causing the ratchet pole 10 to mesh with the ratchet teeth 5a formed on the outer periphery of one flange 5.

The guide plate 6 is rotatably supported by inserting a hole 6c into the shaft 8, and is pressed against the flange 4 surface by a compression spring 7 which is in elastic contact between the guide plate 6 and the side wall of the frame 2, thereby creating a frictional force. The spool 3 slides into and engages with the spool 3 so that it can rotate integrally with the spool 3. In the center of the side surface of the guide plate 6 on the flange 4 side, a recess 6b is formed which is recessed by the height of the ratchet tooth 4a and receives the ratchet tooth 4a.

A seat portion 6p for the spring 7 is formed at the innermost periphery of the other side of the guide plate 6, and a spiral guide portion 6h that rotates several times counterclockwise is formed on the outside thereof. The outer circumferential edge 6g of the seat portion 6p and the outer diameter of the bush 5 substantially match. Spiral guide part 6h
Reverse direction guide portion 6d from near the inner peripheral side toe portion 6i of
are formed in a counterclockwise direction. A stepped portion 6g is located at the intersection of the reverse guide portion 6d and the spiral guide portion 6h.
The spiral guide portion 6h forms a deeper groove. Further, the toe portion 6f of the reverse direction guide portion 6d is set closer to the seat outer peripheral edge 6g than the toe portion 6i of the spiral guide portion 6h.
Then, a follower 13 is placed in the middle of this spiral guide portion 6h, for example, in a portion slightly counterclockwise from the intersection with the reverse direction guide portion 6d.
The tip of the ratchet tooth 4a falls down and engages with the ratchet tooth 4a.
A through hole 6j is formed as a locking portion that cooperates with the belt to prevent rotation of the spool 3 in the belt winding direction. This through hole 6j is set at a position exactly on the same circumference as the ratchet teeth 4a of the flange 4. Further, a slope 6h is formed on the edge of the through hole 6j on the side where the spiral guide portion 6h advances in the counterclockwise direction.

The spiral guide portion 6h has an inclined surface 6 from a portion proceeding approximately half a turn counterclockwise from the inner toe portion 6i.
1, and then gradually descends, and in this embodiment, after about 4 turns, it rises again by the slope 6m and ends at the platform 6n. The spiral guide portion 6h is separated by a wall 6r up to the vicinity of the above-mentioned slope 6l, but after that it is separated by a step portion 6a formed as it gradually descends to form the guide portion 6h. The guide portion 6h is separated. The platform 6n is set at the same height as the wall 6r or slightly higher.

The follower 13 is made of steel wire, and includes an end portion 13a for locking into the split groove 2d of the support pin 2c, and a helical spring portion 13b that functions as both a torsion spring and a compression spring. , a linearly extending portion 13c, and a follower end portion 13d.
The helical spring portion 13b connects the follower end 13d to the spool 3 which intersects the spiral winding of the spiral guide portion 6h.
The guide member 6h is biased in the axial direction and in the direction perpendicular to the spiral guide portion 6h.

The follower support 14 is loosely fitted onto the support pin 2c, and is pressed against the side wall surface of the frame 2 by the helical spring portion 13b of the follower 13. The intermediate portion of the linearly extending portion 13c of the follower 13 is supported by the arm portion 14a of the support 14, thereby reinforcing the follower 13.

The disengagement means 17 includes a release lever 18 rotatably supported on a support pin 16 protruding from the side wall of the frame 2, and a Bowden cable 19 as an actuation means for actuating the release lever 18. . The release lever 18 has a follower 1 at the tip.
A wedge-shaped cam part 20 having a gentle slope 20a that allows the release lever 3 to ride gradually is integrally molded, and one end is engaged with the groove 16a of the support pin 16, and the other end is formed in the middle part of the release lever 18. small hole 1
The first,
The rotational force in the clockwise direction shown in Figure 2 is applied. Also,
The tip of the cam portion 20 is connected to the follower 13 and the frame 2.
It is arranged so that it can enter between the side wall, specifically between the back side of the arm portion 14a of the follower support 14 and the side wall of the frame 2.

The Bowden cable 19 has a pin 1 protruding from an arm portion 18a extending on one side of the release lever 18.
8c, and by pulling the Bowden cable 19, the release lever 18 is rotated counterclockwise in FIGS. 1 and 2. Although this Bowden cable 19 can be operated manually using a buckle release button or the like, in this embodiment, it is linked to a door (not shown) and is pulled when the door is opened.

Next, the operation of this embodiment will be described in detail.

When the door is opened and an occupant is seated, and the door is closed, the release lever 18 is rotated by pulling and releasing the Bowden cable 19 as the door is closed, causing the follower 13 to rise above the guide plate 6. Then, it is returned to its original position by its own elasticity. As described above, the follower 13 is biased by the helical spring portion 13b in the axial direction of the spool 3 and in the direction perpendicular to the spiral guide portion 6b.
contacts the peripheral edge 6g of the seat on the guide plate 6, which has approximately the same diameter as the outer diameter of the bush 5, and the tip 13d contacts the surface of the guide plate 6.

Next, when the belt 1 is pulled out to attach the belt, the guide plate 6 rotates together with the flange 4 because it is frictionally engaged with the flange 4. This information board 6
During the rotation process, since the toe 6b of the reverse guide portion 6d is set closer to the outer peripheral edge 6g of the seat, the follower end 13d is moved to the toe 6b while the guide plate 6 rotates once. Capture and engage. As a result, the guide plate 6 is prevented from further rotating in the direction of belt withdrawal and slips between it and the flange 4, while the belt 1 continues to be withdrawn (see FIGS. 7 and 8).

When the belt 1 is fully pulled out and the buckle and tongue (not shown) are engaged, the occupant assumes a correct seating posture.
The belt 1 is wound up by the force of the spring 9. In the winding process of the belt 1, when the guide plate 6 rotates together in the winding direction due to frictional engagement with the flange 4, the follower end 13d separates from the toe 6f of the reverse guide part 6d. From the stepped portion 6g to the spiral guide portion 6
h side and engages with the inner peripheral side toe 6i of the spiral guide portion 6h. Due to this engagement, the guide plate 6
Further rotation in the belt winding direction is prevented, causing slippage between the belt 1 and the flange 4, and the winding of the belt 1 is continued (see FIGS. 9 to 12).

Next, when the occupant moves his or her body forward a little, belt 1
is pulled out by a small amount, and due to the integral rotation of the guide plate 6 with the flange 4, the follower end 13d separates from the toe 6i and falls into the through hole 6j (13th,
(See Figure 14). Through hole 6 of this follower end 13d
By falling inward, the follower end 13d engages with the ratchet teeth 4a of the flange 4, preventing rotation of the spool 3 in the winding direction, resulting in a tensionless state. That is, the belt 1 has an angle θ between the toe 6i of the spiral guide portion 6h and the through hole 6j.
There will be slack by the length corresponding to . When the belt 1 is subsequently pulled out, the guide plate 6 rotates together with the flange 4, so that the follower end 13d first moves up along the slope of the ratchet tooth 4a, and then moves up the through hole 6j. It rises along the slope 6h, escapes from the through hole 6j, and moves outward along the spiral guide portion 6h. When the occupant returns from the forward leaning position to the original normal seating position, belt 1
is wound up again, and the follower end 13d moves toward the inner circumference along the spiral guide portion 6h, and returns to the through hole 6j.
It is captured by the ratchet teeth 4a and becomes tensionless.

Therefore, the belt 1 is always tensionless at the initially set tensionless length.

Here, after setting the tensionless length, the length of the belt that is further pulled out without canceling this memory is determined by the spiral guide portion 6h from the through hole 6j.
Although it is uniquely determined by the number of spiral turns, in this embodiment, it is set to approximately four turns, which is considered to be sufficient for practical use. When the belt 1 is further pulled out for some special reason, the follower end 13d runs onto the platform 6n formed at the end of the spiral guide 6h along the slope 6m (Figs. 17 and 18). ), guide section 6h
The restriction in the inner peripheral direction of the guide plate is released, and the punch returns to the outer peripheral edge 6g of the seat portion of the guide plate 6 due to the urging force of the follower 13 itself in the direction of the spool axis. At this time, the height of the platform 6n is equal to or slightly higher than the inner wall 6r of the spiral guide 6h.
Since it is set higher than r, the follower 13 instantly returns to the inner circumferential side due to the spring force of the helical spring portion 13b, so that the follower end 13d does not get caught on the wall 6r.

When a passenger exits the vehicle, it is considered that the passenger normally disengages the buckle and tongue (not shown), removes the belt 1, and then opens the door (not shown) and exits the vehicle. In this case, the belt 1 is still in a tensionless state when the engagement between the buckle and the tongue is released.
Then, when the door is opened, the Bowden cable 19 is pulled as the door opens, and the release lever 1
8 is rotated counterclockwise in FIG. 2 against the force of the helical spring 21. By rotating the release lever 18 in the counterclockwise direction, the wedge-shaped cam portion 20 at the tip enters between the back surface of the arm portion 14a of the follower support 14 and the side wall of the frame 2. Here, cam part 2
0 has a gentle slope 20a at its tip, so when the cam part 20 enters, the arm part 14a, together with the follower 13, gradually rides on this gentle slope 20a, and therefore, even with a relatively small operating force, the follower end 13d
is removed from engagement with the ratchet teeth 4a against the force of the winding spring 9, and raised from the guide portion 6h against the spring force of the helical spring portion 13b. As a result, the ratchet teeth 4a of the follower end 13d,
The engagement with the through hole 6j is released, and the follower 13 is biased toward the cam portion 20 by its own biasing force in the spool axis direction.
The ball slides on the flat surface 20b and returns until it hits the outer periphery of the button 5 with a snap. In this door open state, the follower 13
Since it rests on the flat surface 20b of the cam portion 20, the follower end portion 13d is still floating above the surface of the guide portion 6h. Then, when the door is closed, the pulling force of the Bowden cable 19 is released, so the release lever 18 returns to its original state by the force of the helical spring 21, and the follower 13 slides on the gentle slope 20a of the cam part 20 and releases the helical spring. Due to the spring force of the portion 13b, the end portion 13d comes into contact with the surface of the guide plate 6 and returns to the original set position.

FIG. 19 shows another embodiment of the invention.

In this embodiment, in addition to the flange 4, the flange 4
A disk 4' having approximately the same diameter as the disk 4' is used, and a pin 4'b protruding from the back side of the disk 4' is fitted into a small hole 4b formed in the flange 4 to be integrally assembled with the flange 4. be. Furthermore, ratchet teeth 4'a are recessed on the same predetermined circumference on the side surface of the disc 4' on the guide plate 6 side, so that the ratchet teeth 4'a can be engaged with and disengaged from the follower end 13d. Therefore, in this embodiment, as shown in FIG. 20, the recess 6b of the previous embodiment is not provided on the back side of the guide plate 6, and the guide plate 6 and the disk 4' come into sliding contact over substantially the entire surface, making it even more effective. The guide plate 6 and the disk, and thus the flange 4, can surely rotate together through frictional sliding contact and engagement.

21 and 22 show still another embodiment of the present invention. That is, in this embodiment, the relationship between the center side and the outer peripheral side of the spiral guide portion 6h of the guide plate 6 is reversed, and the opposite direction guide portion 6d and the toe of the spiral guide portion 6h are 6i is located on the outermost side of the guide plate 6, and a platform 6n with a slope 6m is set on the inner side. Therefore, the ratchet teeth 4a of the flange 4 are set closer to the outer circumference of the flange 4 in accordance with the setting closer to the outer circumference of the through hole 6j. Naturally, the biasing force of the follower 13 in the direction intersecting the spiral winding is set toward the outer periphery. Furthermore, when the follower end 13d is disengaged, the follower 13 is engaged with the toe 2b' of the follower penetration hole 2b shown in FIG. 1 and returns to the original set position. In this example, a wall 6y is formed on the outer peripheral edge of the guide plate 6 for safety reasons, and the follower 13 engages with the wall 6y to return to the set position.

In each of the embodiments described above, the spiral guide part is formed in a stepped shape, but if the guide part is separated by a wall, the guide part can be formed flat.

Further, the sloped base portion on the outermost or innermost circumference of the spiral guide portion is not necessarily required if the belt is not drawn out unnecessarily long after tensionless storage.

Furthermore, the reverse direction guide part is also unnecessary when the belt is arranged so as to be wound around a retractor and worn by the occupant, such as in the case of a passive seat belt. In this case, the toe of the spiral guide portion may be set closer to the innermost circumference or closer to the outermost circumference of the guide plate.

Furthermore, as a means of operating the release lever,
It may be an electromagnetic actuator that electrically detects the opening and closing of the door and the engagement and disengagement of the buckle and the tongue, and operates based on this detection action.

Further, the above is a case in which the present invention is applied to a device in which the guide plate is frictionally engaged with the spool so that they can rotate together, but the guide plate is fixedly assembled to the spool. The same can be applied to things.

As described above, according to the present invention, the release lever of the follower disengagement means is provided with a cam portion at its tip that has a gentle slope that allows the follower to ride on the follower gradually, and the cam portion is moved between the follower and the follower by the actuating means. Since the follower is disengaged by entering between the follower and the frame and gradually floating, the disengagement can be performed with a relatively small operating force, which has the advantage of further improving operability.

Further, when an electromagnetic actuator is used as the actuating means, it is possible to use a small actuator with low power, which has the advantage of reducing the size and weight of the entire retractor and reducing costs.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of one embodiment of the retractor of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a partially cutaway front view of the same, Fig. 4 is a side view of the guide plate, and Fig. 5 is a side view of the retractor of the present invention. Cross-sectional view along the 0-0 line in the figure, Figure 6 A, B, C, D
are A-A line, B-B line, and C-C in Fig. 5, respectively.
7, 9, 11, 13, 15, and 17 are side views showing the relationship between the guide plate and the follower when the retractor is in operation. Figure 8 is a cross-sectional view taken along line E-E in Figure 7, Figure 10 is a cross-sectional view taken along line F-F in Figure 9,
Fig. 12 is a sectional view taken along line GG in Fig. 11, Fig. 14 is a sectional view taken along line H-H in Fig. 13,
Figure 6 is a sectional view taken along line I-I in Figure 15, and Figure 18
The figures are a sectional view taken along the J-J line in Fig. 17, Fig. 19 is an exploded perspective view showing the second embodiment of the present invention, and Fig. 20 is an exploded perspective view showing the second embodiment of the present invention.
The figure is a cross-sectional view showing the relationship between the disk, the guide plate, and the actuator in the same embodiment, Figure 21 is a side view showing the guide plate in particular of the third embodiment of the present invention, and Figure 22 is the K of Figure 21. - It is a sectional view along the K line. DESCRIPTION OF SYMBOLS 1...Belt, 2...Frame, 3...Spool, 6...Guide plate, 6h...Spiral-shaped guide part, 6
j...Locking part (through hole), 6h...Slope, 9...
Winding spring, 13... Follower, 17... Engagement release means, 18... Release lever, 19... Operating means, 20... Cam portion, 20a... Gentle slope.

Claims (1)

[Scope of utility model registration request] It has a frame, a spool rotatably supported on the frame, a spring that biases the spool in the belt winding direction, and a spiral guide portion on one side, which is concentric with one end of the spool. a guide plate that is attached to the frame and rotates integrally with the spool; comes into elastic contact with the spiral guide part, moves along the spiral guide part as the guide plate rotates, and falls into engagement with a locking part provided at a predetermined position of the spiral guide part. , the guide plate and the spool are prevented from rotating in the belt winding direction, and the tip of the guide plate and the spool is prevented from rotating in the belt unwinding direction by climbing over the slope formed on one side edge of the locking part. In a seatbelt retractor, the seatbelt retractor includes a follower that allows rotation in a belt withdrawal direction, and an engagement release means that releases the engagement between the follower and the locking part, wherein the engagement release means is rotatably attached to the frame. the release lever, and an actuating means for rotating the release lever so that the tip of the lever enters between the follower and the frame; A seatbelt retractor characterized by forming a wedge-shaped cam portion having a gentle slope for riding on.