JP4512423B2 - Reclining adjuster - Google Patents

Description

  The present invention relates to a reclining adjuster that is attached to a seat of a vehicle or the like and appropriately adjusts an inclination angle of a seat back with respect to a seat cushion.

  In the conventional reclining adjuster, the sector gear is fixed to the seat back, while the sector gear and the detachable worm gear are rotatably attached to the seat cushion. The worm gear is connected to the operating shaft, and the meshing of the worm gear with the sector gear is released by pulling the operating shaft in the axial direction and further lifting it. When a load is applied to the seat back in this state, the seat back tilts and the tilt angle can be quickly changed.When the hand is released from the operating shaft, the worm gear meshes with the sector gear again, and the seat back Held in position. Also, if fine adjustment of the seat back tilt angle is required, rotating the operating shaft and rotating the worm gear will cause the sector gear meshing with the worm gear to gradually rotate, making the seat back stepless to any tilt angle. (For example, refer to Patent Document 1).

  Also, a sector gear and a worm gear having a lead angle greater than the friction angle are attached to the seat back and the seat cushion, respectively, and the seat back is tilted so that the worm gear is rotated via the sector gear to appropriately change the seat back tilt angle. A reclining adjuster has also been proposed (see, for example, Patent Document 2).

  Furthermore, in the case of a reclining adjuster having a sector gear and a worm gear that mesh with each other, abnormal noise may occur due to backlash that is play between the tooth surfaces of the sector gear and the worm gear. A reduction is also proposed (for example, see Patent Document 3).

Japanese Utility Model Publication No. 42-7950 (first page, FIG. 1) JP 10-217817 A (page 4, FIG. 1) Japanese Unexamined Patent Publication No. 2000-342371 (pages 2 and 3, FIG. 1)

  In the conventional reclining adjuster described above, if a large deceleration is applied to the vehicle body due to a vehicle collision or the like, a large load is applied to the meshing surface between the sector gear and the worm gear. The strength was secured.

  Therefore, in order to improve the strength of the reclining adjuster, it is necessary to increase the sizes of the sector gear, the worm gear and related parts.

  The present invention has been made in view of such problems of the prior art, and provides a compact reclining adjuster that can withstand heavy loads using a sector gear and a worm gear that have the required strength during normal use. The purpose is to do.

  In order to achieve the above object, the invention according to claim 1 of the present invention is a reclining adjuster for appropriately adjusting the inclination angle of the seat back with respect to the seat cushion, and is attached to the seat cushion so as to be rotatable. And a helical gear meshed with the worm gear and attached to the seat back via an auxiliary lock mechanism, and the auxiliary lock mechanism is connected to the helical gear and is part of the seat back. An external gear to be fitted and an internal tooth that is attached to the seat cushion and houses the external gear, and in normal use, the seat back is seated by engaging the worm gear and the helical gear. When a load greater than a predetermined value is input to the seat back, a part of the external gear is By shape, characterized in that so as to hold the seat back relative to said seat cushion at a predetermined angle by the inner teeth meshed.

  According to a second aspect of the present invention, a part of the seat back is a seat back mounting bracket, and a plurality of protrusions formed on the seat back mounting bracket and a plurality of protrusions formed on the external gear. The first convex portion is fitted.

  Furthermore, in the invention described in claim 3, two second convex portions are formed between the two adjacent first convex portions, and the other end of the pin whose one end is connected to the helical gear. It is made to fit in the recessed part between the said 2nd convex parts.

    According to the present invention, the worm gear is rotatably attached to the seat cushion, the helical gear meshing with the worm gear is attached to the seat back via the auxiliary lock mechanism, and the auxiliary lock mechanism is connected to the helical gear. An external gear that fits with a part of the seat back and an internal tooth that is attached to the seat cushion and houses the external gear are provided. During normal use, the seat back is seat cushioned by meshing with the worm gear and the helical gear. In contrast, when a load greater than a predetermined value is input to the seat back, the seat back is predetermined with respect to the seat cushion by deforming a part of the external gear and meshing with the internal teeth. Because it is held at an angle of, it can withstand heavy loads by using sector gears and worm gears that have the required strength during normal use It is possible to provide a compact reclining adjuster.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a reclining adjuster A according to the present invention, which is attached to a pair of brackets 2 and 4 that are integrally connected to each other so as to be rotatable, and is rotatably attached between the brackets 2 and 4. A worm gear 6 and a helical gear 8 that meshes with the worm gear 6 are provided. The brackets 2 and 4 are attached to a seat cushion (not shown), and the helical gear 8 includes a plurality of helical gears 8 as described later. It is attached to a seat back (not shown) via a pin, an external gear, and a seat back mounting bracket. The seat back is always urged forward by the elastic force of a balance spring (not shown). The worm gear 6 and the helical wheel 8 that mesh with each other have a lead angle larger than the friction angle.

  The front end and the rear end of the worm gear 6 are rotatably supported by the front bearing 10 and the rear bearing 12, respectively. The front bearing 10 and the rear bearing 12 are held by the brackets 2 and 4. Further, the brackets 2 and 4 have rectangular openings 2a and 4a formed in portions facing the worm gear 6, and a part of the worm gear 6 protrudes outside from the rectangular openings 2a and 4a, so that the worm gear 6 and the bracket 2 are provided. , 4 is prevented. That is, by providing the brackets 2 and 4 with the rectangular openings 2a and 4a, the distance between the brackets 2 and 4 is set short.

  A number of gear-shaped notches 6a as locked portions are formed on the cutting edge surface of the worm gear 6 located in the vicinity of the front bearing 10, and the lock claws are opposed to these notches 6a from below and mesh as necessary. A lock member 14 having 14 a is interposed between the brackets 2 and 4 and is swingably mounted around the mounting shaft 16. The lock member 14 is connected to an operation lever (not shown) for manually moving the lock claw 14a up and down to lock or unlock the lock claw 14a with respect to the notch 6a. The lock claw 14a is always biased upward (in the lock direction).

  Further, circular holes 4b and 8a are formed in the center of the bracket 4 and the helical gear 8, and one end is fitted into the circular hole 4b, and an intermediate portion thereof is freely inserted around the circular hole 8a. The helical gear 8 is rotatably attached. Further, a seat back mounting bracket 18 is rotatably attached to the other end (end portion on the bracket 2 side) of the central shaft 20, and the seat back is attached to the seat back mounting bracket 18. Furthermore, a plurality of (for example, four) pin holes 8b are formed at predetermined intervals around the circular hole 8a, and one end of the pin 22 is fitted into each pin hole 8b.

  Between the helical gear 8 and the seat back mounting bracket 18, an external gear 26 that meshes with the internal teeth 2 b formed on the bracket 2 when a large load is input is provided. A plurality of convex portions projecting toward the central portion are formed on the inner side of the external teeth 26a formed in the above. These convex portions include a plurality of (for example, four) substantially rectangular first convex portions 26b formed at predetermined intervals along the circumferential direction, and two adjacent first convex portions 26b. It consists of two mountain-shaped second convex portions 26c formed between them, and the other end of each pin 22 whose one end is inserted into the pin hole 8b of the helical gear 8 is between the two second convex portions 26c. Is inserted into the recess 26d.

  Further, the seat back mounting bracket 18 is formed with a circular hole 18a into which the end of the central shaft 20 is loosely inserted at the center thereof, and around the circular hole 18a toward the helical gear 8 by press molding, for example. A plurality of substantially U-shaped projecting portions 18b (the same number as the first projecting portions 26b of the external gear 26) formed in a convex shape are provided at predetermined intervals along the circumferential direction. A concave portion 18c having a shape complementary to the first convex portion 26b of the external gear 26 is formed in the installation portion 18b.

  The helical gear 8, the external gear 26, the seat back mounting bracket 18, and the seat back are integrally formed around the central axis 20 by fitting the first convex portion 26 b of the external gear 26 into the concave portion 18 c. The external gear 26 is configured to be rotatable, and is internally concentrically mounted on the bracket 2 in a state in which the external teeth 26 a are separated from the internal teeth 2 b of the bracket 2 by a predetermined distance. Note that the inner teeth 2b located above the worm gear 6 are notched in part (lower part) in order to avoid interference with the worm gear 6.

The operation of the reclining adjuster A having the above configuration will be described below.
In a normal state where the operation lever connected to the lock member 14 is not operated, the lock member 14 is urged in the direction of arrow B by the elastic force of the urging means such as a coil spring, and the lock claw 14a is It meshes with one of 6a. Therefore, the worm gear 6 cannot rotate, and the helical gear 8 that meshes with the worm gear 6 is also prevented from rotating. The external gear 26 is integrally fixed to the helical gear 8 via the pin 22, and the first convex portion 26 b of the external gear 26 and the protruding portion 18 b of the seat back mounting bracket 18 are connected. Because of the fitting, the inclination angle of the seat back with respect to the seat cushion is maintained at a predetermined angle.

  When it is desired to change the inclination angle of the seat back, the lock claw 14a and the notch 6a of the worm gear 6 are operated by operating the operation lever to rotate the lock member 14 in the direction opposite to the arrow B against the elastic force of the urging means. Therefore, the worm gear 6 can be freely rotated.

  Here, the lead angle of the helical gear 8 and the worm gear 6 meshing with each other are set to be larger than the friction angle, and the worm gear 6 rotates when a rotational force around the central axis 20 is applied to the helical gear 8. The seat back is moved forward by the elastic force of the balance spring, or the seat occupant is moved backward by applying a backward load to the seat back against the elastic force of the balance spring. When the hand is released from the operation lever at a desired position, the lock claw 14a of the lock member 14 is reengaged with one of the notches 6a of the worm gear 6 by the elastic force of the urging means, and the rotation of the worm gear 6 is prevented. The inclination angle of the back is kept at the current angle.

  Next, a case where a large load exceeding a predetermined value is input to the seat back due to a vehicle collision or the like will be described.

  When a load greater than the load applied to the seat back during normal use is applied to the seat back, the load is transmitted from the seat back to the seat back mounting bracket 18, the external gear 26, the pin 22, and the helical gear 8 in this order. At this time, since the helical gear 8 is engaged with the worm gear 6 and its rotation is prevented, a large load is applied to the contact surface between the inner surface of the second convex portion 26 c of the external gear 26 and the pin 22. Will be added.

That is, when a large load is applied to the front of the vehicle on the seat back, a large load is applied to the second convex portion 26c adjacent to the C direction of the pin 22, while a large load on the rear of the vehicle is applied to the seat back. A heavy load is applied to the second convex portion 26c adjacent to the direction 22 opposite to the C direction. As a result, one of the two second convex portions 26c located on both sides of each pin 22 is pressed and deformed outward, and the tooth surface located on the outer side in the radial direction moves outward and the bracket 2 Since the inner teeth 2b are engaged with each other, the seat back does not move forward or backward any further.

  In other words, even if a large deceleration is input to the vehicle body due to a vehicle collision or the like, the seat back is suddenly moved forward or backward by the auxiliary lock mechanism including the pin 22, the external gear 26, the internal teeth 2b, and the like. Is prevented.

  Note that, as described above, in the above-described configuration, the seat back is kept at a predetermined inclination angle by fitting the protruding portion 18b of the seat back mounting bracket 18 and the first convex portion 26b of the external gear 26 during normal seating. However, since the distance L (see FIG. 4) between the fitting portion and the central axis of the central shaft 20 can be set relatively long, the strength can be improved with a simple configuration.

  The reclining adjuster according to the present invention has a structure capable of withstanding a heavy load while using a sector gear and a worm gear having a strength required in normal use, and is therefore useful for a vehicle seat or the like to which a heavy load is applied due to a collision or the like. It is.

It is a disassembled perspective view of the reclining adjuster concerning this invention. It is a perspective view of the reclining adjuster of FIG. It is another perspective view of the reclining adjuster of FIG. It is a side view of the state which removed a part of reclining adjuster of FIG.

Explanation of symbols

2,4 bracket, 2a, 4a rectangular opening, 2b internal teeth, 4b circular hole,
6 Worm gear, 6a Notch, 8 Helical gear, 8a Circular hole,
8b pin hole, 10 front bearing, 12 rear bearing, 14 lock member,
14a lock claw, 16 mounting shaft, 18 seat back mounting bracket,
18a circular hole, 18b projecting part, 18c concave part, 20 central axis, 22 pin,
26 external gear, 26a external tooth, 26b first convex part, 26c second convex part,
26d recess, A reclining adjuster.

Claims (3)

A reclining adjuster for appropriately adjusting the inclination angle of the seat back with respect to the seat cushion,
A worm gear rotatably attached to a seat cushion, and a helical gear meshing with the worm gear and attached to a seat back via an auxiliary lock mechanism, the auxiliary lock mechanism being attached to the helical gear. It has an external gear that is connected and fits with a part of the seat back, and an internal tooth that is attached to the seat cushion and houses the external gear. In normal use, the worm gear and the helical gear mesh with each other. While the seat back is held at a predetermined angle with respect to the seat cushion, when a load greater than a predetermined value is input to the seat back, a part of the external gear is deformed to mesh with the internal teeth. A reclining adjuster characterized in that the seat back is held at a predetermined angle with respect to the seat cushion. A part of the seat back is a seat back mounting bracket, and a plurality of projecting portions formed on the seat back mounting bracket and a plurality of first convex portions formed on the external gear are fitted. The reclining adjuster according to claim 1. Two second protrusions are formed between the two adjacent first protrusions, and the other end of the pin whose one end is connected to the helical gear is connected to the recess between the two second protrusions. The reclining adjuster according to claim 2, wherein the reclining adjuster is inserted into the reclining adjuster.

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