JP2010149584A - Seat belt retractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a winding spring device for a seat belt retractor with a function relieving constriction to the chest region of an occupant when attaching a seat belt with a simpler structure. <P>SOLUTION: This winding spring device 13 for the seat belt retractor includes a retainer 15, a main spring 22, a spring cover 23, a ratchet wheel 19, a sub spring 18, and a rotation regulating mechanism. The rotation regulating mechanism includes a first cancel lever 27 oscillating along a first cam groove 24a together with rotation of a control plate 24, and releasing engagement of a lock arm 20 when a webbing is wound by a first rotational number in a winding direction a after start of winding of the webbing, and a second cancel lever 28 oscillating along a second cam groove 26a together with rotation of a second gear 26, and releasing the engagement of the lock arm 20 when it is pulled out to a second rotational number from a fully stored condition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a seat belt retractor including a webbing take-up spring device.

  A conventional seat belt device includes a main spring that urges the spindle in the winding direction, and a sub spring that generates an urging force in a direction opposite to the main spring. When the seat belt is mounted, the seat Various techniques have been devised for reducing the winding force of the belt to relieve the tightening of the chest of the occupant (see, for example, Patent Document 1).

In the winding spring device described in Patent Document 1, the outer end of the compensation spring, which is a sub-spring, cooperates with a ratchet wheel, which is a ratchet wheel, while the inner end is a spindle via a freewheeling clutch. Cooperate with the shaft. The freewheeling clutch causes force transmission from the shaft to the compensation spring when the pinion wheel is blocked and the shaft rotates in the winding direction, and stress is applied to the compensation spring. Acting in the opposite direction to the torque of the main drive spring. On the other hand, the freewheeling clutch allows relative rotational movement of the compensating spring in the winding direction with respect to the shaft. When the belt is removed from the buckle and the claw wheel is unlocked, the claw wheel rotates in the winding direction on the basis of the stressed compensation spring. The freewheeling clutch allows relative rotation of the compensation spring with respect to the shaft in this direction, so that there is no rapid deceleration of the ratchet wheel when the compensation spring is completely loosened.
JP-T-2004-521016

  By the way, in the winding spring device described in Patent Document 1, when the belt is detached from the buckle, the block of the claw wheel is released by the magnetic actuator. At this stage, the freewheeling clutch rotates the hook wheel in the winding direction based on the stress of the compensation spring. Further, when the compensation spring is completely loosened, the winding is performed by the entire torque of the main spring. However, since the stress of the compensation spring varies depending on the buckle release position, depending on the release position, there is a possibility that it cannot be completely wound up when the entire amount is stored.

  The present invention has been made in view of the above circumstances, and its purpose is to have a simpler structure, which can alleviate the tightening of the occupant's chest when the seat belt is worn, and is completely It is an object of the present invention to provide a seat belt retractor that can be wound around.

The object of the present invention is achieved by the following configurations.
(1) a retainer coupled to a spindle around which the webbing is wound;
A ratchet wheel rotatably arranged around the retainer;
A main spring having an inner end connected to the ratchet wheel and biasing the spindle in the winding direction;
A case member to which an outer end portion of the main spring is fixed;
An inner end is fixed to the retainer, an outer end is fixed to the ratchet wheel, and a subspring that biases the spindle in the winding direction with a biasing force smaller than the biasing force of the main spring;
A rotation restricting mechanism for restricting rotation of the ratchet wheel in the winding direction;
A webbing take-up spring device having
The rotation restricting mechanism is
A lock arm arranged to be detachable from the ratchet wheel;
A biasing member that biases the lock arm to engage with the ratchet wheel;
A control plate that rotates integrally with the retainer;
A gear member that rotates in conjunction with the control plate at a different rotational speed;
A first canceling lever that swings with the rotation of the control plate and releases the engagement of the lock arm when the spindle rotates by a first rotational speed in the winding direction after starting the webbing winding;
When the gear member is swung with the rotation of the gear member, the lock is applied when the webbing is pulled out or taken up between the full amount stored state and the spindle rotated by the second rotational speed from the full amount stored state. A second cancel lever for disengaging the arm;
A seat belt retractor comprising a spring device for winding a webbing.

  The seat belt retractor according to the present invention includes a retainer coupled to a spindle around which a webbing is wound, a ratchet wheel rotatably disposed around the retainer, an inner end connected to the ratchet wheel, and the spindle is wound up. Main spring that biases in the direction, case member to which the outer end of the main spring is fixed, the inner end is fixed to the retainer, the outer end is fixed to the ratchet wheel, and the biasing force is smaller than the biasing force of the main spring. It has a subspring that urges the spindle in the winding direction with a force, and a rotation regulating mechanism that regulates the rotation of the ratchet wheel in the winding direction. Thus, in the unlocked state where the rotation of the ratchet wheel is not restricted, the urging force of the main spring is transmitted to the spindle, and in the locked state where the rotation is restricted, only the urging force of the sub spring is transmitted to the spindle.

  The rotation restricting mechanism includes a lock arm that is detachably connected to the ratchet wheel, a biasing member that biases the lock arm to engage with the ratchet wheel, a control plate that rotates integrally with the retainer, and a control A gear member that rotates in conjunction with a rotation speed different from that of the plate, and swings with the rotation of the control plate. After starting the webbing winding, the lock arm is rotated when the spindle rotates by the first rotation speed in the winding direction. Pulling out the webbing between the first cancel lever for releasing the engagement and the swing of the gear member with the rotation of the gear member between the full amount storage state and the state in which the spindle has been rotated by the second rotational speed from the full amount storage state Alternatively, a second cancel lever for releasing the engagement of the lock arm during the winding operation is provided. In such structure, to alleviate the fastening of the occupant's chest when the seat belt is worn (tension Reduce function) that can, can further take fully wound when the total amount stored.

  Hereinafter, a seat belt retractor according to an embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the seat belt retractor 10 includes a retractor frame 11, and a spindle 12 for winding a webbing (not shown) is rotatably supported on the retractor frame 11. A winding spring device 13 for winding the webbing around the spindle 12 is attached to one side in the axial direction.

  The take-up spring device 13 includes a retainer 15, a gear wheel 16, a support plate 17, a sub spring 18, a ratchet wheel 19, a lock between a gear case 14 attached to one side of the retractor frame 11 in the axial direction and a spring cover 23. An arm 20, a coil spring 21, and a main spring 22 are provided. The take-up spring device 13 includes a control plate 24, a first gear 25, a second gear 26, a first cancel lever 27, and a second cancel lever 28 on the side of the spring cover 23. The gear case 14 and the spring cover 23 constitute a case member of the present invention.

  The spring cover 23 is formed with a recess (not shown) for accommodating the main spring 22. The main spring 22 is disposed between the spring cover 23 and the ratchet wheel 19. A sub spring 18, a support plate 17, and a gear wheel 16 are provided between the ratchet wheel 19 and the gear case 14, and the sub spring 18 is disposed so as to be accommodated inside the ratchet wheel 19. ing.

  The retainer 15 is fitted and fixed to one end of the spindle 12 in the axial direction, and rotates integrally with the spindle 12. The retainer 15 has a large-diameter shaft portion 15c in which a slit 15a is formed, and a small-diameter shaft portion 15d that protrudes in the axial direction at the tip thereof. One end of the large-diameter shaft portion 15c in the axial direction has a flange portion 15b that fits with the center hole 17a of the support plate 17 and supports the support plate 17 rotatably. The small-diameter shaft portion 15 d passes through center holes 19 a and 23 a formed in the ratchet wheel 19 and the spring cover 23.

  The main spring 22 is accommodated in the spring cover 23 and is wound in a spiral shape so as to be biased in the winding direction a from the inside toward the outside. An inner end portion of the main spring 22 is engaged with a slit 19e provided around the center hole 19a of the ratchet wheel 19 and connected to the ratchet wheel 19, and an outer end portion is a locking portion formed in the spring cover 23. (Not shown) is locked and fixed.

  The subspring 18 is wound in a spiral shape so as to be biased in the winding direction a from the inside toward the outside with a smaller number of turns than the main spring 22. The inner end of the subspring 18 is engaged with the slit 15 a of the retainer 15 and connected to the retainer 15, and the outer end is locked and fixed to a locking portion (not shown) formed on the ratchet wheel 19. ing.

  Accordingly, when the webbing is pulled out from the spindle 12 and the retainer 15 rotates in the pulling direction b, the subspring 18 urges the retainer 15 and the spindle 12 directly in the winding direction a by the tightened urging force. On the other hand, the main spring 22 urges the retainer 15 and the spindle 12 in the winding direction a through the ratchet wheel 19 and the subspring 18 by the urging force tightened.

  The gear wheel 16 is formed in a ring shape with a plurality of (three in the present embodiment) protrusions 16 a protruding in the axial direction toward the ratchet wheel 19. The gear wheel 16 is fixed to the ratchet wheel 19 and integrally rotates by engaging the protrusions 16 a with a plurality of recesses (not shown) formed in the ratchet wheel 19.

  The support plate 17 is rotatably fitted to the inner peripheral surface of the gear wheel 16. Therefore, the support plate 17 is supported so as to be rotatable relative to the gear wheel 16 and the retainer 15. The support plate 17 rotates integrally when the sub-spring 18 is tightened or released, thereby preventing the sub-spring 18 from coming into contact with the resin gear case 14. Reduces rotational resistance.

  The ratchet wheel 19 is disposed so as to be rotatable relative to the retainer 15 via the sub spring 18. The ratchet wheel 19 extends in the axial direction from the disk portion 19b and the side surface near the main spring 22 of the disk portion 19b, from the convex portion 19f having the center hole 19a and the slit portion 19e, and from the side surface near the sub spring 18 of the disk portion 19b. An annular portion 19d extending in the axial direction and having ratchet teeth 19c on the outer peripheral surface is formed.

  The lock arm 20, the coil spring 21, the control plate 24, the first gear 25, the second gear 26, the first cancel lever 27, and the second cancel lever 28 rotate in the winding direction a of the ratchet wheel 19. A rotation restricting mechanism for restricting

The control plate 24 is coupled to a small diameter shaft portion 15 d of the retainer 15 extending from the center hole 23 a of the spring cover 23. The first and second gears 25 and 26 are rotatably attached to the side surface of the spring cover 23. The control plate 24 meshes with the large gear 25 a of the first gear 25. The small gear 25 b of the first gear 25 meshes with the second gear 26. The first cancel lever 27 is formed in a substantially V shape and is supported on the side surface of the spring cover 23 so as to be swingable. One arm portion 27 a of the first cancel lever 27 has a protrusion 27 b that engages with a first cam groove 24 a formed in a substantially spiral shape on one side surface of the control plate 24. The second cancel lever 28 is also formed in a substantially V shape and is supported on the side surface of the spring cover 23 in a swingable manner. One arm portion 28 a of the second cancel lever 28 has a protrusion 28 b that engages with a second cam groove 26 a formed in a substantially spiral shape on one side surface of the second gear 26.
The inner and outer ends of the substantially spiral second cam groove 26a are closed to terminate, but the inner and outer sides of the substantially spiral first cam groove 24a are respectively circular. Has a shape.

  The lock arm 20 includes three arms 20a, 20b, and 20c, and is rotatably supported by the gear case 14. The first arm 20a is provided with a convex portion 20d that protrudes in an axial direction from an arc hole 23b formed in the spring cover 23, and the other arm portion 27c of the first cancel lever 27 and the second cancel portion 27c. The lever 28 can be brought into contact with the other arm portion 28c.

  A coil spring 21 is spanned between the second arm 20 b of the lock arm 20 and the gear case 14. The third arm 20 c is disposed so as to be able to engage with and disengage from the ratchet teeth 19 c of the ratchet wheel 19.

  As shown in FIG. 2, the rotation restricting mechanism has a protrusion 28b of the second cancel lever 28 between the state in which the webbing is not pulled out (the entire amount is stored) and the state in which the spindle 12 is rotated by the second rotational speed. Is positioned closer to the inner end of the cam groove 26 a of the second gear 26. The second cancel lever 28 presses the convex portion 20d of the lock arm 20 so that the third arm 20c of the lock arm 20 moves away from the ratchet teeth 19c of the ratchet wheel 19 against the biasing force of the coil spring 21. Include.

  On the other hand, when the webbing is pulled out by a predetermined amount (the amount by which the spindle 12 rotates at the second rotational speed), the second cancel lever 28 is moved in accordance with the rotation of the second gear 26 as shown in FIG. The protrusion 28b moves to the outside of the cam groove 26a of the second gear 26. The position shown in FIG. 3 is a position where the second cancel lever 28 releases the convex portion 20 d of the lock arm 20. The third arm 20 c of the lock arm 20 is engaged with the ratchet teeth 19 c of the ratchet wheel 19 by the biasing force of the coil spring 21. Thereby, the ratchet wheel 19 is prevented from rotating in the winding direction a. When the webbing is pulled out and the subspring 18 is released from tightening in the winding direction a, the third arm 20c of the lock arm 20 is engaged with the ratchet teeth 19c until the subspring 18 is completely tightened. When only the sub spring 18 is wound and the sub spring 18 is completely wound and pulled out, the third arm 20c of the lock arm 20 gets over the ratchet teeth 19c while the ratchet wheel 19 is pulled out in the pulling direction b. To be rotated. Although not shown, when the webbing is pulled out, the protrusion 27b of the first cancel lever 27 moves from the inside to the outside of the cam groove 24a of the control plate 24 according to the rotation of the control plate 24. .

  Further, as shown in FIG. 5, the rotation biasing force of the main spring 22 does not act on the retainer 15 in a state where the rotation of the ratchet wheel 19 in the winding direction “a” is restricted by the rotation restriction mechanism. For this reason, after the occupant's webbing pull-out operation is completed, only the rotational urging force with the sub-spring 18 tightened acts as the winding force of the retainer 15.

  Then, after the start of webbing winding, when the spindle rotates in the winding direction by the first number of rotations (three rotations), the protrusion 27b of the first canceling lever 27 becomes the cam groove of the control plate 24 as shown in FIG. It moves on the inner circle of 24a, and the engagement of the lock arm 20 is released. After the release, the sub-spring 18 is completely tightened by receiving the tightening force of the main spring 22. As a result, the main spring 22 releases the tightening up to the number of rotations at which the winding has been performed.

  Therefore, the first cancel lever 27 and the second cancel lever 28 of the rotation restricting mechanism are independent from each other. In other words, the first cancel lever 27 is turned on and off depending on the number of rotations within a predetermined range, and the second cancel lever 28 is completely separated from the first cancel lever 27 and is in a certain amount before being mounted from the fully retracted state. ON-OFF at the selected range. For this reason, at a certain winding amount before mounting, the tension reducing function does not work because the lock arm 30 is not operated by the second cancel lever 28 regardless of whether the first cancel lever 27 is ON-OFF or not. On the other hand, when the second cancel lever 28 is not engaged with the lock arm 30, as shown in FIGS. 9 and 10, the function and the case where the tension reduction functions by the ON-OFF by the first cancel lever 27. There are cases where it does not.

  Next, the operation of the winding spring device will be described together with the operation when the occupant wears / releases the seat belt.

1) When the webbing is started when the webbing is mounted on the occupant, the retainer 15 rotates in the pulling direction b together with the spindle 12 (see FIG. 1). In this state, the ratchet wheel 19 can rotate freely without being locked, and therefore can rotate in the pulling-out direction b via the subspring 18. Therefore, the main spring 22 connected to the sub spring 18 and the ratchet wheel 19 is tightened, and a rotational biasing force in the winding direction a is generated with respect to the retainer 15.

2) When the webbing is pulled out beyond a predetermined amount, the second cancel lever 28 of the rotation restricting mechanism is rotated counterclockwise by the second cam groove 26a as shown in FIG. The arm 20 is released. For this reason, rotation of the ratchet wheel 19 in the winding direction (winding direction a: see FIG. 1) is prevented. Thereafter, when the webbing is further pulled out, the ratchet wheel 19 rotates in the pulling direction b while the third arm 20c of the lock arm 20 gets over the ratchet teeth 19c.

  As shown in FIG. 4, when the webbing is further pulled out, the protrusion 27 b of the first cancel lever 27 is positioned on the outer circle of the cam groove 24 a of the control plate 24. For this reason, the first cancel lever 27 stays away from the convex portion 20d of the lock arm 20 regardless of the rotation of the ratchet wheel 19 in the pulling direction b.

3) After fitting the tongue into the buckle and attaching the webbing to the occupant, wind up the excess slack of the webbing. In this case, the rotation biasing force of the main spring 22 does not act on the retainer 15 in a state where the rotation of the ratchet wheel 19 is restricted in the winding direction a by the rotation restricting mechanism. For this reason, only the rotation urging force with the sub-spring 18 tightened acts as the take-up force of the retainer 15, and the take-up force of the retainer 15 is reduced (tension reducing function). Therefore, as shown in FIG. 6, the spindle is rotated twice from the webbing drawer (webbing length is 250 to 300 mm) to wind up the excess slack portion and fit the webbing to the occupant. In this state, the winding force of the retainer 15 is reduced, so that tightening of the occupant on the chest is alleviated.

4) When the tongue is removed from the buckle, the seat belt is released, and the webbing is wound, the winding force of the retainer 15 is reduced by the subspring 18 until the spindle 12 is wound three times. It is rolled up. Then, when the spindle 12 is wound three times, the protrusion 27b of the first cancel lever 27 moves on the inner circle of the cam groove 24a of the control plate 24 as shown in FIG. As a result, the other arm portion 27 c presses the convex portion 20 d of the lock arm 20, thereby unlocking the ratchet hole 19 and the lock arm 20. When further wound, the first cancel lever 27 remains stationary with its protrusion 27b positioned on the inner circle of the cam groove 24a, so that the unlocked state is maintained. When the lock is released, the rotation biasing force of the main spring 22 wound until the ratchet wheel 19 is locked when the webbing is pulled out acts on the retainer 15, and the webbing is wound by the rotation biasing force of the main spring 22. .

5) Here, the winding amount of the webbing in a state where a predetermined winding amount is wound up, that is, in a state where the tongue is fitted in the buckle without wearing the webbing (in the state where the tongue is fitted in the buckle, The second cancel lever 28 presses the lock arm 20 to release the lock from the state where the amount is the largest) to the state where the entire amount is stored. Therefore, as shown in FIG. 8, even when the webbing is once pulled out during the storage and the first cancel lever 27 releases the press of the lock arm 20, the ratchet is caused by the second cancel lever 28. The wheel 19 is not locked. Therefore, it is possible to prevent the tension reducing function from operating near the entire amount storage, and to completely wind up the webbing that is heavy on the tongue.

  As described above, according to the “winding spring device 13 for seat belt retractor” of the present embodiment, the retainer 15 connected to the spindle 12 around which the webbing is wound, and the retainer 15 is rotatably disposed around the retainer 15. A ratchet wheel 19, an inner end connected to the ratchet wheel 19, a main spring 22 that urges the spindle 12 in the winding direction, a spring cover 23 to which the outer end of the main spring 22 is fixed, and a retainer 15, an inner end is fixed to the ratchet wheel 19, an outer end is fixed to the ratchet wheel 19, a subspring 18 that biases the spindle 12 in the winding direction with a biasing force smaller than the biasing force of the main spring 22, and the ratchet wheel 19 A rotation restricting mechanism for restricting rotation in the winding direction. Thereby, in the unlocked state where the rotation of the ratchet wheel 19 is not restricted, the urging force of the main spring 22 is transmitted to the spindle 12, and in the locked state where the rotation is restricted, only the urging force of the sub spring 18 is transmitted to the spindle 12. Is transmitted to.

  The rotation restricting mechanism rotates integrally with the lock arm 20 detachably attached to the ratchet wheel 19, the coil spring 21 that urges the lock arm 20 to engage with the ratchet wheel 19, and the retainer 15. The control plate 24, the second gear 26 that rotates in conjunction with the rotation speed different from that of the control plate 24, and swings along the first cam groove 24a as the control plate 24 rotates, and starts webbing winding. After that, the first cancel lever 27 for releasing the engagement of the lock arm 20 when the spindle rotates by the first rotation number (three rotations) in the winding direction a, and the second gear 26 is rotated in accordance with the rotation of the second gear 26. 2 is swung along the cam groove 26a, and the spindle 12 is moved to a second rotational speed (the occupant is The second state is to release the engagement of the lock arm 20 when the webbing is pulled out or taken up between the state where the webbing is rotated by the amount of rotation of the webbing when the tongue is fitted in the buckle without attaching the ring. Since the cancel lever 28 is provided, it is possible to ease the tightening of the occupant on the chest when the seat belt is worn, and to completely wind up when the entire amount is stored.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

It is a disassembled perspective view for demonstrating the component of the seatbelt retractor which is one Embodiment of this invention. It is a side view of the winding spring apparatus which shows the state of the 2nd cancellation lever at the time of the webbing extraction | drawer operation start. It is a side view of the winding spring apparatus which shows the state of the 2nd cancellation lever at the time of pulling out predetermined amount of webbing. It is a side view of the winding spring apparatus which shows the state of the 1st cancellation lever when webbing is further pulled out. It is a side view of a winding spring device which shows the state of the 1st cancellation lever at the time of winding start of webbing (at the time of one rotation of winding). It is a side view of the winding spring apparatus which shows the state of the 1st cancellation lever at the time of winding up predetermined amount of webbing (at the time of winding 2 rotation). It is a side view of a winding spring device showing the state of the 1st cancellation lever at the time of winding exceeding the predetermined amount of webbing (after 3 windings). It is a side view of the winding spring device which shows the state of the 1st and 2nd cancellation lever in the winding amount with the largest winding residual amount in the state which latched the tongue to the buckle. It is a side view of the winding spring device which shows the state of the 1st and 2nd cancellation lever in the winding amount with the largest winding residual amount in the state which latched the tongue to the buckle. It is a side view of the winding spring device which shows the state of the 1st and 2nd cancellation lever in the winding amount with the largest winding residual amount in the state which latched the tongue to the buckle.

Explanation of symbols

10 Seat belt retractor (seat belt device)
12 Spindle 13 Winding spring device 14 Gear case 15 Retainer 16 Gear wheel 17 Support plate 18 Sub spring 19 Ratchet wheel 20 Lock arm (rotation restricting mechanism)
21 Coil spring (rotation restriction mechanism)
22 Main spring 23 Spring cover 24 Control plate (rotation restricting mechanism)
25 1st gear (rotation restricting mechanism)
26 Second gear (rotation restricting mechanism)
27 First cancel lever (rotation restricting mechanism)
28 Second cancel lever (rotation restricting mechanism)

Claims (1)

A retainer coupled to a spindle around which the webbing is wound;
A ratchet wheel rotatably arranged around the retainer;
A main spring having an inner end connected to the ratchet wheel and biasing the spindle in the winding direction;
A case member to which an outer end portion of the main spring is fixed;
An inner end is fixed to the retainer, an outer end is fixed to the ratchet wheel, and a subspring that biases the spindle in the winding direction with a biasing force smaller than the biasing force of the main spring;
A rotation restricting mechanism for restricting rotation of the ratchet wheel in the winding direction;
A webbing take-up spring device having
The rotation restricting mechanism is
A lock arm that is detachably attached to the ratchet wheel;
A biasing member that biases the lock arm to engage with the ratchet wheel;
A control plate that rotates integrally with the retainer;
A gear member that rotates in conjunction with the control plate at a different rotational speed;
A first canceling lever that swings with the rotation of the control plate and releases the engagement of the lock arm when the spindle rotates by a first rotational speed in the winding direction after starting the webbing winding;
When the gear member is swung with the rotation of the gear member, the lock is applied when the webbing is pulled out or taken up between the full amount stored state and the spindle rotated by the second rotational speed from the full amount stored state. A second cancel lever for disengaging the arm;
A seat belt retractor comprising a spring device for winding a webbing.

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