JPH0116698B2 - - Google Patents

Description

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

It is widely known that the tension caused by the winding spring of a seatbelt retractor compresses the occupant's chest and causes discomfort.As one way to solve this problem, many seatbelt retractors with a tensionless mechanism have been developed. It is also being implemented. According to one example, two friction plates having cam surfaces of different shapes on the outer diameter are frictionally engaged with a flange at one end of the spool, and each cam of the friction plates is attached to the spool. controlling the pawl that engages with the ratchet in the belt winding direction,
Pulling out when the belt is attached -> A small amount of entrainment after the belt is attached -> A tensionless system that detects the subsequent small amount of withdrawal and engages the pole and the ratchet to prevent the spool from being drawn in any further. It is. According to another example, engagement between a buckle and a tongue is sensed by a buckle switch, which energizes a solenoid to connect a pair of meshed gears that cannot rotate in one direction to the spool. The gears attached directly to the gears are meshed with each other, and since the pair of gears cannot rotate in one direction, the gears are tensionless.
Since the belt can be rotated in the opposite direction, the belt can be freely pulled out. Therefore, the length of the belt pulled out when the tongue and buckle are engaged is memorized and set as the tensionless length, and that tensionless length is also used for subsequent pulling out. This automatically stops the belt from winding up.

However, each of these known tensionless retractors has drawbacks. That is, in the former tensionless retractor, since there is a cam on the periphery of the friction plate, the memory is canceled if the tensionless length is pulled out one or more times after being memorized. Normally, when an occupant moves forward from a seated position, the spool of the seatbelt retractor is pulled out by 3 to 4 rotations, but with this type of tensionless retractor, even when the occupant returns to the normal position, it is not in a tensionless state. In addition, it is necessary to pull out a small amount of the belt, which inevitably causes discomfort to the occupants.
In the latter type, the belt pull-out length when the buckle and tongue are engaged becomes the tension-less length, so the belt is not wound up with more slack than necessary, and in the event of a collision, the belt will be unwound. This is dangerous because the occupant is thrown forward, causing a so-called secondary collision in which the passenger collides with a functional component inside the vehicle.

The present invention seeks to overcome these drawbacks of the prior art. That is, by engaging the buckle and the tongue, attaching the belt, and pulling out the belt by a certain amount after completely winding up the slack of the belt, this certain amount of drawn-out length is memorized as the tensionless length. , its memory length (tensionless length) is determined by the subsequent normal movement of the occupant.
The object of the present invention is to provide a seat belt retractor with a tensionless mechanism that always provides a constant amount of belt slack to the occupant.

In order to achieve the above object, in the present invention, the tensionless mechanism includes a locking part formed on the flange surface of one side of the spool and having a slope on one side edge;
It has a spiral guide part on one side, and a through hole provided at a predetermined position of the spiral guide part and having an inclined surface on one side edge, and is arranged concentrically with the flange surface of the spool. , pressed by a spring,
a guide plate that is attached to the frame that pivotally supports the spool; The tip is biased in the vertical direction as well as in the direction crossing the spiral winding, and the tip elastically contacts the spiral guide and moves along the spiral guide as the guide plate rotates. It falls into the through hole of the shaped guide part and engages with the locking part to prevent rotation of the guide plate and spool in the belt winding direction, and the tip of the spool falls into the locking part against rotation in the belt pull-out direction. a follower that allows the guide plate and the spool to rotate in the belt withdrawal direction by climbing over the slopes of one side edge of the section and the through hole; and a follower disposed between the guide plate and the follower, the follower and an engagement release means for pushing the tip of the follower in a direction away from the spiral guide part to release the engagement between the follower and the locking part. As a result, after the belt is attached by engaging the buckle and the tongue, the belt is pulled out a certain amount and the follower and the locking part engage, thereby memorizing a certain tensionless length.
Even when the belt is subsequently pulled out, the memorized length is not released due to the follower falling into the through hole again and engaging with the locking part during the belt winding process, and the belt When the belt is released, the engagement release means releases the engagement between the follower and the locking portion, thereby allowing the belt to be completely wound up.

1 to 20 show the seat belt retractor of the present invention. The seatbelt 1 is assembled to the spool 3 by inserting the loop portion 1a provided at the end thereof into the elongated hole 3a of the spool 3, and then inserting the shaft 8 therein. Flanges 4 and 5 are attached to both ends of the spool 3, and the flange 5 has ratchet teeth 5a formed in the radial direction of the flange to prevent the belt from elongating in an emergency. , the flange 4 has a locking portion protruding in the axial direction of the spool and facing in the belt winding direction, in order to engage with a follower 13 to be described later and prevent the spool from rotating in the belt winding direction;
For example, a ratchet tooth 4a with a slope formed on one side edge.
is formed integrally with the flange 4. Spring means 9 are attached to one end of the shaft 8, constantly biasing the belt in the winding direction. The frame 2 is made of a steel plate bent into a U-shape, and has a shaft through hole 2a 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. The frame 2 also includes a pendulum support 11, a pendulum 12 swingably attached to the pendulum support 11, and an upper surface of the pendulum 12 with one end supported by a fan-shaped hole 2f provided in the side wall of the frame 2. A known emergency locking mechanism consisting of a ratchet pawl 10 abutting the flange 5 is disposed corresponding to the flange 5. This emergency locking mechanism prevents a certain decrease in vehicle acceleration from pendulum 12.
The swing of the pendulum 12 causes the ratchet pole 10 to tilt upward, causing the ratchet pole 10 to mesh with the ratchet teeth 5a formed on the outer periphery of the flange 5, thereby tightening the belt of the spool 3. Prevents rotation in the pull-out direction.

The guide plate 6 is inserted into the shaft 8 and rotatably supported, and is pressed against the flange 4 surface by a compression spring 7 elastically loaded between the guide plate 6 and the side wall of the frame 2 to frictionally slide into contact. , are engaged and can rotate integrally with the spool 3.

The flange-side side surface of the guide plate 6 has an annular frictional engagement surface 6a and an annular concave surface 6b that is recessed from the frictional engagement surface by the height of the ratchet teeth 4a and accommodates the ratchet teeth. ing. On the guide surface side, there is a seat portion 6p of the compression spring 7 on the innermost side.
A spiral guide portion 6h is formed on the outer side of the guide portion 6h, which rotates counterclockwise several times and expands its diameter. A reverse guide plate 6d extends counterclockwise from near the inner end 6i of the spiral guide portion 6h. A stepped portion 6g is provided at the intersection of the reverse guide portion 6d and the spiral guide portion 6h, so that the spiral guide portion 6h forms a deeper groove. Note that the inner end 6f of the reverse guide portion is arranged closer to the center than the inner end 6i of the spiral guide portion (see FIG. 6A). A through hole 6j is provided in the spiral guide part 6 h outside the intersection with the reverse direction guide part. This through hole requires approximately the same distance from the axis as the ratchet tooth 4a, and an inclined surface 6 is provided outward (counterclockwise) of the spiral guide portion.
k (see Figure 6B). After the spiral guide portion 6h rises by the slope 6l (see FIG. 6C), it gently descends and rotates about four times.
It rises by a slope of 6m and ends at a platform 6n (6th
(See Figure D).

The spiral guide portion 6h extends up to the vicinity of the slope 6l mentioned above.
are separated by a wall 6r, but thereafter the guide portion 6h is separated by a stepped portion 6x formed as the guide portion 6h is gradually lowered.
The platform 6n is set at the same height as the wall 6r or slightly higher.

The follower 13 is a split groove 2d of the pin 2c of the frame.
an end portion 13a for locking to the end portion 13a, and a helical portion 13b having the functions of both a torsion spring and a compression spring.
, a linearly extending portion 13c, and a follower end portion 13d. The helical portion 13b is connected to the follower end 1
3d is biased in the axial direction of the spool 3, which intersects with the spiral winding of the spiral guide portion 6h, and in the direction perpendicular to the spiral guide portion 6h. In addition, the follower 6
is integrally formed from an elastic wire.

The follower support 14 is loosely fitted onto the pin 2c, and is pressed against the frame 2 by the helical portion 13b of the follower. The extension part 14a locks the intermediate part of the linear extension part 13c of the follower into one body,
The engagement between the follower end 13d and the ratchet 4a is reinforced.

The magnet 16 is fixed to the frame 2, and the follower release plate 18 is supported in the rectangular hole 2e of the frame 2 so as to be rotatable by a small angle.
It has one end that fits between the extension part 14a of the magnet 16 and the frame 2, and the other end that can be attracted to the core of the magnet 16. A spring 17 is disposed between the release plate 18 and the magnet 16 so that the release plate 18 does not normally come into contact with the follower 13. When the other end of the release plate 18 is attracted against the spring 17 by the excitation of the magnet 16, the linearly extending part 13c of the follower 13 is pushed outward together with the extension part 14a at one end, and the engagement is released here. constitute means.

Next, the operation of this embodiment will be explained.

The magnet 16 is energized until the door is opened, the occupant is seated, and the door is closed.
3 is pressed outward by the follower release plate 18,
The engagement with the guide plate 6 is released, and it comes into contact with the outer periphery of the bush 15 due to its own urging force in the direction of the spool axis. Next, when the door is closed, the follower 13 comes into contact with the inner edge 6q of the guide plate 6 (the outer diameter of the bush 15 and the inner edge of the guide plate coincide) due to its bias in the axial direction of the spool. Next, when the belt is pulled out to be attached, the guide plate 6 is in frictional engagement with the flange 4, so they begin to rotate together. However, within the first rotation, the inner end 6f of the reverse direction guide part 6d and the follower end 13d are engaged and captured, and the subsequent rotation of the guide plate 6 in the belt withdrawal direction is prevented, and the flange of the spool The belt is pulled out while slipping occurs between the 7th and 4th belts.
(See Figure 8). When the belt is fully pulled out and the buckle (not shown) and the tongue engage, the belt will be rolled up a little as the occupant assumes a correct seating posture. Due to this winding, the spool 3 and the guide plate 6 frictionally engaged with the spool rotate counterclockwise. Then, the follower end 13d advances inside the reverse direction guide section 6d in the direction of the intersection with the spiral guide section, and crosses the step section 6g between the reverse direction guide section and the spiral guide section (9th , see Figure 10) reaches the inner end 6i of the spiral guide portion, and therefore the subsequent rotation of the guide plate 6 in the belt winding direction is prevented, and the subsequent belt winding is caused by the guide plate 6 and the flange 4. It is absorbed by the slip in between (see Figures 11 and 12). Next, when the occupant moves his/her body a little, the belt is pulled out by a small amount, and the follower end 13d moves counterclockwise within the spiral guide section 6h, passes through the intersection with the reverse direction guide section, and ( There is a stepped section 6g from the spiral guide section to the reverse direction guide section, so it does not move.)
It reaches the through hole 6j (see FIGS. 13 and 14). The follower end 13d inserted into the through hole 6j engages with the ratchet teeth 4a formed on the flange 4, and
The spool 3 is prevented from rotating in the belt winding direction, resulting in a tensionless state. Note that the belt has a slack with a length corresponding to the angle θ between the inner end 6i of the spiral guide portion and the through hole 6j. During subsequent withdrawal, the guide plate 6 and flange 4 rotate as one, so that the follower end 13d first rises along the slope of the ratchet tooth 4a, and then rises along the slope of the through hole 6k.
By ascending along the same direction, it escapes from the through hole 6j and moves outward on the spiral guide portion 6h. When the occupant returns from the forward-leaning position to the original normal sitting position, the belt is wound up again and the follower end 13d
Returns inside the spiral guide part and enters the through hole 6j again.
It is caught inside and engaged with the ratchet teeth 4a, becoming tensionless. During this time, the guide plate 6 and the flange 4 do not slip, and therefore, the tensionless state is ensured at the initially set tensionless length.
Note that after setting the tensionless length, the length that can be further pulled out without canceling the memory of the length is controlled by the number of spirals of the spiral guide portion from the through hole 6j, but in this embodiment. In the example, it is set to approximately 4 rotations, which is considered to be sufficient for practical purposes.
If this rotates more than four times for some special reason, the follower 13 rides on the sloped base part 6n provided at the end of the spiral guide part, is released from the restraint by the guide part 6h, and rotates itself. When the guide plate is biased in the direction of the spool axis, it snaps back to the inner edge 6q of the guide plate (see FIGS. 17 and 18). Also, usually
Tensionless state, that is, the follower end 13d
It is considered that the seat belt is released from the occupant by disengaging the buckle and the tongue while the buckle passes through the through hole 6h and engages with the ratchet tooth 4a.
In this case, when the occupant opens the door, the magnet 16 is energized by the door switch, the follower release plate 15 moves the follower outward, and the guide plate 6
It releases its engagement with the guide plate, and similarly returns to the inner edge 6q of the guide plate with a snap due to its own biasing force.

FIG. 19 shows another embodiment of the invention. In this embodiment, a disk 4' having approximately the same diameter as the flange 4 is used separately from the flange 4, and a pin 4' protruding from the back side of the disk 4' is fitted into a small hole 4b made in the flange 4. It is assembled integrally with the flange 4. In addition, ratchet teeth 4'a having a slope on one side edge are recessed on the same predetermined circumference of 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. It is set as. 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.

21 and 22 show still another embodiment of the present invention. 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 portion 6i of the spiral guide portion 6h are On the outermost side of the guide plate 6, a platform 6n with a slope 6m is set on the inner side. Therefore, the ratchet teeth 4 of the flange 4
A is set near the outer periphery of the through hole 6j. Naturally, the radial bias of the follower 13 against the guide plate 6 is set toward the outer circumference. In addition, the follower end 13
When disengaging d, the follower 13 engages with the toe of the follower penetration hole 2b shown in FIG. 1 and returns to the original set position. A wall 6y is formed on the outer peripheral edge of the roller 6, and the follower 13 engages with the wall 6y to return to the set position. In each of the above embodiments, the spiral guide part is formed in a stepped shape, but if the guide parts are separated by a wall, the spiral guide part may be formed flat. be able to. 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.

FIG. 23 shows another follower release means. An end of a wire 20 is attached to one end of the follower release plate 15', and the other end of the wire 20 is attached to the door to release the follower from the guide plate using the opening force of the door.

FIG. 24 shows a drive circuit for the magnet 16 of the seat belt retractor shown in the first embodiment.

The present invention has many embodiments in addition to those described above. For example, (1) The follower release means was performed by opening the door, but the engagement of the buckle and tongue, the ON/OFF of the ignition switch, the presence or absence of a load on the seat surface, the passive seat belt Electromagnetic means such as a magnet or solenoid driven by the system or a manual switch, or mechanical means such as a wire or link may be used, and the follower may be released by pulling out the belt beyond a certain level.

(2) When the follower release means is actuated by the engagement of the buckle and the tongue, the above-mentioned reverse is performed on the condition that the belt is not continuously pulled out further after the buckle and the tongue are engaged. No direction guide is required. It is sufficient that the inner end of the spiral guide portion extends to the inner edge of the guide plate.

(3) It is not necessary to directly prevent the rotation of the spool in the winding direction by the engagement between the follower end 13d and the ratchet teeth 4a. The force of the winding spring 9 may be counteracted by meshing with each other. In this case, the force applied to the follower and the force for driving the follower release means can be reduced.

Since the present invention has the structure described in the claims, it has the following effects.

(1) After the belt is installed, it becomes tensionless when the belt is pulled out by a certain amount after being wound up, so the belt does not need to be pulled out more than necessary, improving operability.

(2) The amount of slack in the belt is determined by the angle between the end of the spiral guide and the through hole, and the optimum belt length for the occupant can be provided, so the amount of belt slack is greater than necessary. It is safe and will not cause any damage.

(3) Once the tension-less length is memorized, it cannot be canceled by normal occupant movements, and can always be set to tension-less when the correct seating position is restored. (4) It is inexpensive because it has a small number of parts and is easy to assemble. It is also small and lightweight.

[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 Cross-sectional view along line O-O in the figure, Figure 6 A, B, C, D
are A-A line, B-B line, and C-C in Fig. 4, respectively.
7, 9, 11, 13, 15, and 17 show the relationship between the guide plate and the follower when the retractor is in operation. A side view, FIG. 8 is a cross-sectional view taken along line E-E in FIG. 7, FIG. 10 is a cross-sectional view taken along line F-F in FIG. 9, and FIG. 12 is a cross-sectional view taken along line G-G in FIG. 14 is a sectional view taken along line H-H in FIG. 13, FIG. 16 is a sectional view taken along line I-I in FIG. 15, and FIG. 18 is a sectional view taken along line J-J in FIG. 17. 19 is an exploded perspective view showing the second embodiment of the present invention, FIG. 20 is a sectional view showing the relationship between the disk, the guide plate, and the actuator in the same embodiment, and FIG.
22 is a sectional view taken along line KK in FIG. 21, and FIG. 23 is a perspective view showing another example of the disengagement means. 24 are electrical circuit diagrams of the disengagement means shown in FIG. 1. 1... Belt, 2... Frame, 3... Spool, 4... Flange, 4a, 4'a... Locking part (ratchet teeth), 6... Guide plate, 6h... Spiral-shaped guide part, 6j... Through hole, 6k... Slope of through hole, 7... Spring, 9... Spring, 13... Follower, 18, 15'... Engagement release means.

Claims (1)

[Claims] 1 A frame, a spool rotatably supported on the frame, a spring that biases the spool in the belt winding direction, and a lock formed on the flange surface of one side of the spool and having a slope on one side edge. and a spiral guide portion on one side, a through hole provided at a predetermined position of the spiral guide portion and having an inclined surface on one side edge, concentrically with the flange surface,
and a guide plate that is pressed and attached by a spring and is able to frictionally slide and engage with the flange and rotate integrally with the spool, and a guide plate that is attached to the frame and perpendicular to the spiral guide part. direction as well as the direction that intersects the spiral winding, the tip elastically contacts the spiral guide and moves along the spiral guide as the guide plate rotates, and the spiral It falls into the through hole of the guide part and engages with the locking part to prevent rotation of the guide plate and the spool in the belt winding direction, and the tip of the guide plate and the spool fall into the locking part against rotation in the belt pull-out direction. and a follower that allows the guide plate and the spool to rotate in the belt withdrawal direction by climbing over the slope of each side edge of the through hole, and a follower that is disposed between the guide plate and the follower and that allows the follower to rotate. A seatbelt retractor comprising an engagement release means whose distal end is pushed in a direction away from the spiral guide part to release the engagement between the follower and the locking part.