JP2001157615A - Reclining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit application to a seat with a built-in shoulder belt by improving the strength of a lock greatly in a so-called round reclining device, furthermore permit application to two-door vehicles and recreational vehicles due to the ability to correspond to inclining back seats ahead and expand the rotating range of the back seats close to 180 deg., and satisfy the request for making the device lightweight with a slight increase in the number of parts. SOLUTION: Lock gears 5 and 6 are arranged at respective quarter positions where four pieces are unsymmetrical in a round reclining device. A flat projection part 22 is formed on a gear plate 2 that can engage with the lock gears 5 and 6, and the length angle βof the flat projection part 22 is made larger than the interval angle α between the adjacent lock gears 5 and 6. Furthermore, the shapes of the lock gears 5 and 6 are made unsymmetrical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat reclining device for adjusting a tilt angle of a back seat, and more particularly to a reclining device having a mechanism suitable for application to an automobile seat.

[0002]

2. Description of the Related Art As conventional miniaturized reclining devices, there are those described in Japanese Patent No. 2,645,583 and Japanese Patent Application Laid-Open No. 6-125821, which are also called round reclining devices. The round reclining device includes a substantially disk-shaped base plate and a gear plate rotatably mounted on the base plate, and a cavity (space) is provided between the base plate and the gear plate. A reclining lock / unlock mechanism is accommodated in the cavity. That is, internal teeth are formed on the inner periphery of the gear plate, and a plurality of lock gears having external teeth that can mesh with the internal teeth are assembled to the base plate so as to be slidable only in the radial direction.
The lock gear is pressed radially outward by a cam disposed at the center, and the cam is urged to rotate by a spring in a direction to press the lock gear against the internal teeth of the gear plate. Normally, the lock gear is engaged with the internal teeth of the gear plate by the urging force of the spring to lock the gear plate to the base plate.

[0003] A center shaft is inserted into a non-circular center hole (square hole) of the cam. By rotating the center shaft, the cam rotates against the urging force of the spring,
The lock can be released by releasing the force of the cam pressing the lock gear to release the engagement between the lock gear and the gear plate. Then, a reclining operation lever is provided on the center shaft to rotate the center shaft.

[0004] By fixing the base plate of the round reclining device to the seat bracket and the gear plate to the back seat bracket, the tilt angle of the back seat can be arbitrarily set and locked. That is, by pulling the reclining operation lever and rotating the center shaft, the round reclining device is unlocked and the inclination angle of the back seat is adjusted. If the reclining operation lever is released from the finger after the adjustment, the cam rotates by the urging force of the spring, the round reclining device returns to the locked state again, and the back seat is locked at the adjusted angular position. The above structure has the advantage that the round reclining device can be unitized, the external size of the device can be reduced, and the device is suitable for mass production because all the components of the lock mechanism are housed in the cavity between the base plate and the gear plate. There is.

Here, in a coupe-type two-door vehicle or the like, the back seat of the front seat is moved forward to facilitate getting on and off the rear seat. In order to simplify the operation when the back seat is moved forward, the internal teeth are not provided on the entire circumference of the gear plate so that the round reclining device maintains the unlocked state when the back seat is moved forward, Japanese Patent No. 2,645,583 discloses a configuration in which a flat convex portion on which a lock gear can ride is provided. When the back seat was moved forward, the lock gear rides on the flat convex portion so as not to mesh with the internal teeth. This patent publication discloses three lock gears, and each lock gear is disposed at a position of every 120 °. For this reason, the permissible rotation range of the back sheet is 120 ° at the maximum.

Japanese Utility Model Publication No. Sho 53-15529 discloses that two lock gears (lock plates) are used, and the two lock gears are arranged symmetrically at 180 ° to cancel the central component acting on the cam (pressing piece). There is disclosed an apparatus in which the strength of a round reclining device is improved.

Japanese Patent Laid-Open Publication No. Hei 10-71042 discloses a round reclining apparatus using two sets of round reclining units each composed of a base plate, a gear plate, a lock gear and the like. The purpose is to improve the rigidity of the reclining device by overlapping two sets. Here, two lock gears are used for one set of round reclining units.

[0008]

In the conventional automobile, the above-described round reclining device has a sufficient reclining strength. However, in recent years, there has been a movement in which the upper support point of the seat belt is provided not on the center pillar of the vehicle body but on the upper side of the back seat. This is because even if the seat is moved back and forth, the comfort of wearing the seat belt is not impaired. In a convertible vehicle, since there is no center pillar, the upper side of the back seat is inevitably the upper support point of the seat belt. As described above, in an automobile in which the upper side portion of the back seat is the supporting point of the seat belt, the load applied to the seat belt is applied to the back seat as it is, and a torque is applied to the reclining device.

During normal operation, there is no problem if the load applied to the seat belt is applied to the reclining device as torque. However, in an emergency such as a frontal collision of an automobile, an abnormally large torque is applied to the reclining device depending on the mode of the frontal collision, and the strength of the reclining device may be insufficient.

[0010] The strength of the round reclining device is determined by the total number of teeth of the lock gear and the effective length and the number of guide portions of the base plate for radially supporting the lock gear. Therefore, a lock gear having a large number of sheets is advantageous. Although three lock gears are advantageous, strength may still be insufficient. Therefore, if the number of lock gears is four and they are simply arranged at every 90 °, satisfactory strength can be obtained. However, in the case where a flat convex portion on which the lock gear can ride is provided in a part of the gear plate, the rotation allowable range of the back seat is limited to a maximum of 90 °,
There was a problem that it was not possible to cope with moving the back seat forward.

[0011] Also, the two round reclining units described in Japanese Patent Application Laid-Open No. 10-71042 have sufficient strength. However, the number of parts is doubled and the weight is also reduced by simply doubling.
Twice as much as the cost. This is contrary to the demand for weight reduction and cost reduction of automobile parts.

Further, when the number of the lock gears is increased while keeping the shape of the lock gears in a simple shape extending straight from the external teeth to the rear end portion, the lock gears are retracted and detached from the internal teeth of the gear plate to be unlocked. In this case, the rear ends of adjacent lock gears interfere with each other, causing a problem, and there is a problem that the number of lock gears cannot be increased. If the width of the lock gear is reduced to prevent interference at the rear end, there is a problem that the number of external teeth decreases and the strength decreases. If the shape of the lock gear is reduced in width at the rear and the shape of the lock gear is made symmetrical with a mushroom shape while keeping the number of external teeth as it is, the guide will be guided in the radial direction at the mushroom-shaped stem, so the effective length of the guide portion And the strength is reduced.

Therefore, the present invention can cope with the forward movement of the back seat while greatly improving the strength of the round reclining device, and can extend the allowable rotation range of the back seat to a maximum of about 180 °. It is an object of the present invention to provide a reclining device which can be applied to a door car or an RV car, and can satisfy the demand for automobile parts such as a small increase in the number of parts and a reduction in weight and cost. Further, the present invention increases the number of lock gears, which is indispensable for improving the strength of the round reclining device, while preventing interference of the rear end portion of the lock gear, and without reducing the effective length of the guide portion. It is an object of the present invention to provide a reclining device that can be used.

[0014]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, there is provided a base plate, a gear plate rotatably mounted on the base plate and having internal teeth, and A plurality of lock gears having external teeth that can be engaged with the internal teeth of the gear plate and are assembled and guided by the base plate so as to be movable only in the direction, and control the movement of the lock gears in the radially outward direction so that the lock gears A cam that meshes with the internal teeth, a spring that urges the cam to rotate in a direction that meshes the lock gear with the internal teeth, and a spring that is inserted through a non-circular center hole of the cam and rotates to oppose the urging force of the spring. A center shaft capable of rotating the cam to release the engagement between the lock gear and the gear plate. In the so-called round reclining device), the gear plate has a flat convex portion on the same circumference as the internal teeth, on which the lock gear can ride at a height higher than the internal teeth, and the internal teeth and the flat convex portions alternate. And four lock gears are prepared, and two lock gears are paired for each two lock gears, and the two lock gears of each pair are arranged at positions 180 ° apart from each other, while different The pair of lock gears are arranged at non-quadrant positions which are not perpendicular to each other, and the interval angle (α) between the external teeth of the two adjacent lock gears of the four lock gears indicates that The length angle (β) of the flat convex portion is made larger (α <β).

With this configuration, since the torque applied between the base plate and the gear plate is supported by two pairs, that is, four lock gears, the locking strength of the reclining device is extremely increased. Further, since the two paired lock gears are arranged at positions separated from each other by 180 °, the central component acting on the cam at the time of locking can be canceled, and the lock strength of the reclining device can be improved.

Further, since the length angle (β) of the flat convex portion is larger than the interval angle (α) between the external teeth of the two adjacent lock gears, the flat convex portion is formed with the rotation of the gear plate. There is a moment when both of the two adjacent lock gears are riding. In the state where at least one of the four lock gears rides on the flat convex portion and is pushed down in the radial center direction, the cam cannot rotate according to the urging force of the spring. Continue.
Therefore, for example, during the rotation of the gear plate from when the flat convex portion pushes down the right end of the external teeth of one lock gear to when it separates from the left end of the external teeth of the adjacent lock gear, the unlocked state continues. That is, 2 where the flat convex portions are close to each other.
A state in which the lock gears are unlocked over a wide angle range by bridging the lock gears appears. This unlocked angle range can be used for the angle range in which the back seat is moved forward.

When the flat convex portion is completely separated from the lock gear, the lock gear can mesh with the internal teeth of the gear plate, and the cam is opposed to the biasing force of the spring by the center shaft in the same manner as in a normal round reclining device. The gear plate remains locked unless it is rotated.
This lockable angle range can be used as a range for adjusting the inclination of the back seat.

The angle range obtained by adding the above-mentioned unlocked angle range and the lockable angle range, that is, the rotation allowable range of the back seat, is such that the paired lock gears are arranged at positions 180 ° apart from each other. Therefore, the maximum angle is 180 °. As described above, it is possible to increase the allowable rotation range of the back seat up to 180 ° while increasing the reclining strength by using four lock gears.

The number of parts of the reclining device is only two lock gears compared to the conventional device. There are more guides to guide the lock gear,
Since the guide portion is a portion formed by press working integrally with the base plate, it does not lead to an increase in the number of parts. The same applies because the flat convex portion is also formed integrally with the gear plate by press working. Thus, it has become possible to increase the reclining strength while minimizing the increase in the number of parts.

According to a second aspect of the present invention, in the so-called round reclining device, the shape of the lock gear is such that one of the two sides from the external teeth to the rear end has one side. While linearly extending from the end of the external teeth to the rear end in parallel to the sliding direction of the lock gear, the other side is narrowed from the end of the external teeth and narrowed, and then linearly. The lock gear has an asymmetric shape that reaches the rear end in parallel with the sliding direction of the lock gear.

With this configuration, the lock gear is asymmetric and its rear end is narrowed, so that the adjacent
Even if the lock gears are retracted due to unlocking, the rear ends do not interfere with each other. Since the shape of the lock gear is asymmetric, and one side portion extends linearly from the end of the external teeth to the rear end, one guide portion of the base plate also has a long length from the vicinity of the external teeth to the rear end. Effective length can be secured. For this reason, a very high lock strength can be ensured in the rotation direction in which the lock gear is supported with this long effective length. The direction of abnormally large torque applied to the reclining device of the shoulder belt built-in seat in the event of an emergency such as a frontal collision of the car described above is fixed in a certain direction, so an asymmetrical lock gear is arranged corresponding to that fixed direction. By doing so, it is possible to secure a strong strength against such an emergency. On the other hand, the other side of the lock gear is shorter than the one side, and the effective length of the other guide is shorter. Therefore, although the lock strength is sufficient in the rotation direction opposite to the above, the lock strength is lower than in the forward rotation direction. However, there is no problem in the reverse rotation direction, that is, the direction in which the back seat is tilted backward, because the required lock strength is smaller than the direction in which the back seat is tilted forward. Furthermore, it is not preferable that the lock strength in the direction in which the back seat is tilted backward has an excessive lock strength from the viewpoint of reducing the impact force (G resistance) on the human body when a rear collision of the vehicle is assumed. In the present invention, by setting the effective length of the guide portion on the other side appropriately, the lock strength in the forward direction is maintained sufficiently high while the lock strength in the rear direction is required by the body of the automobile body. The lock strength can be set to a sufficient level.

[0022]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing an automobile seat equipped with a reclining device according to the present invention. As is well known, a seat mainly includes a cushion seat 101 and a back seat 102, and a seat bracket (lower bracket) 103 is fixed to the cushion seat 101, and a back seat bracket (upper bracket) 104 is fixed to the back seat 102. Is done. The lower bracket 103 and the upper bracket 104 are fixed to different plates of the round reclining unit 105, respectively, and are rotatable with each other, that is, the inclination of the back seat 102 can be changed. A reclining operation lever 107 is mounted on a center shaft 106 at the center of the round reclining unit 105. Round reclining unit 105, center shaft 1
06, the reclining operation lever 107 constitutes a reclining device.

When the reclining operation lever 107 is pulled upward, the reclining device is unlocked and the back seat 1
02 can be adjusted. Here, the back sheet 102
Is an angle adjustment range in which the back sheet 102 is locked to the angular position at that time when the finger is released from the reclining operation lever 107, and the angle range of the illustration B in which the back sheet 102 is tilted forward. Is a free rotation range in which the unlocked state is maintained even when the finger is released from the reclining operation lever 107. As shown in the drawing, the back sheet 102 is rotatable from a forwardly inclined position in contact with the cushion sheet 101 to a backwardly inclined position in which the back sheet 102 is flat with the cushion sheet 101. The structure of such a reclining device will be described below.

FIG. 2 is a partially cutaway plan view showing the round reclining unit 105 of the reclining device according to the present invention, and FIG. 3 is a sectional view taken along line AA of FIG. FIG.
As shown in the figure, this round reclining unit 1
Reference numeral 05 denotes a substantially disc-shaped base plate 1 and a substantially bowl-shaped gear plate 2 which are overlapped with each other, and which are integrally rotatable with each other by ring caulking of the side peripheral portions with a bracket 3. Internal teeth 21 are formed on the inner peripheral surface of the gear plate 2. There is a cavity (space) 4 between the base plate 1 and the gear plate 2. As shown in FIG. 2, four lock gears 5, 6, 5,
6, a central cam 7, two spiral springs 8, 8, a member for locking and unlocking the lever plate 9 and the like are provided.

The base plate 1 has six guide projections 1
1, 12, 13, 11, 12, and 13 are base plates 1
And a linear portion (guide portion) of a side peripheral portion of each of the guide projections 11, 12, and 13.
And the lock gears 5 and 6 are slidably supported only in the radial direction. Outer teeth 51, 6 meshable with the inner teeth 21 of the gear plate 2 are provided on the outer peripheral side of each of the lock gears 5, 6.
1 is formed. The internal teeth 21 are not formed over the entire inner peripheral surface of the gear plate 2, but are formed on the same circumference as the internal teeth 21 so that the lock gears 5, 6 can ride over the internal teeth 21 at a height higher than the internal teeth 21. 22 are formed partially, and the internal teeth 21 and the flat convex portions 22 are alternately continuous.

The base plate 1 has two crescent-shaped protrusions 15 formed on the inner upper surface thereof on the left and right in the drawing, and one hook portion of the spiral spring 8 is engaged with each of the crescent-shaped protrusions 15. ing. A cam 7 is rotatably disposed at the center of the base plate 1. The cam 7 is plate-shaped and has a cam surface at both ends that abuts against the rear end surfaces of the lock gears 5 and 6 and a hook engaging portion that engages with the other hook portion of the springs 8, 8. It has a hole 71. The square hole 71 forms a non-circular center hole. The cam 7 is engaged with the spiral springs 8, 8 and is strongly urged in the counterclockwise direction in the drawing. The cam 8 comes into contact with the lock gears 5 and 6 and strongly urges the lock gears 5 and 6 radially outward by an urging force in the counterclockwise rotation direction. The center shaft 106 shown in FIG. 1 is inserted into the square hole 71 of the cam 7, and by rotating the center shaft 106, the cam 7 is rotated clockwise in the drawing against the urging force of the spiral springs 8, 8. You can do it.

The cam 7 is provided with two columnar projections 72 projecting upward in FIG. Also,
Each of the lock gears 5 and 6 is also formed with columnar projections 52 and 62 so as to protrude upward in the drawing. And cam 7
Further, a lever plate 9 is placed and incorporated from above the four lock gears 5, 6, 5, 6. Holes are formed in the lever plate 9 to be fitted with the protrusions 72, 72 of the cam 7, and the holes and the protrusions 72, 72 are fitted to rotate the lever plate 9 integrally with the cam 7. The lever plate 9 has four cam holes 91,
91, 91, 91 are opened, and the cam holes 91 are assembled so that the projections 52, 62 of the lock gears 5, 6 are engaged with each other. When the cam 7 and the lever plate 9 are rotated in the clockwise direction in the drawing, the peripheral edge of the cam hole 91 comes into contact with the projections 52, 62 of the lock gears 5, 6, so that the lock gears 5, 6 are retracted in the radial center direction. It has become.

FIG. 4 is a sectional view taken along line BB of FIG. FIG.
2 shows a center shaft 106 not shown in FIG. A spline portion is formed at the tip of the center shaft 106, and the square hole 71 (see FIG.
(Not shown in FIG. 2) is formed, and an operation lever mounting portion is formed at the rear end. As is clear from FIG. 3, the gear plate 2 is rotatably assembled to the base plate 1 such that the outer peripheral surface of the gear plate 2 is in sliding contact with the inner peripheral surface of the base plate 1, and is caulked by the bracket 3 so that the two plates 1 2 are integrally incorporated. The unit in which the base plate 1 and the gear plate 2 are integrated as described above is referred to as a round reclining unit, and the unit in which the center shaft 106 is incorporated in the round reclining unit is referred to as a round reclining device. Reclining operation lever 1 on center shaft 106
07 is attached.

On the back surface of the base plate 1, a plurality of circular protrusions 1B are formed on the same circumference, and on the back surface of the gear plate 2, a plurality of circular protrusions 2B are formed. Are also shown). These circular projections 1B, 2B are provided with a seat bracket (lower bracket) 10
3 or back seat bracket (upper bracket) 10
4. Usually, the lower bracket 103 is attached to the base plate 1 and a plurality of circular projections 1 are attached.
B fixes the base plate 1 so as not to rotate.
The upper bracket 104 is attached to the gear plate 2 so that the gear plate 2 rotates with the tilt of the back seat by a plurality of circular projections 2B. Of course, the bracket for attaching the base plate 1 and the gear plate 2 may be reversed.

FIG. 5 is an explanatory view showing the relationship between the arrangement of the lock gears 5 and 6 and the internal teeth 21 and the flat convex portions 22 of the gear plate 2. Four lock gears (5, 6, 5, 6) are prepared. The lock gear is paired every two gears (5 and 5
Or 6 and 6), two lock gears (5 and 5) of each pair.
Or 6 and 6) are located 180 ° apart from each other. On the other hand, different pairs of lock gears (5 and 6) are arranged in close positions that are not perpendicular to each other. That is, the four lock gears 5, 6 are arranged at non-quadrant positions. Here, an interval angle α representing the interval between the external teeth 51 and the external teeth 61 of the two adjacent lock gears (5 and 6) by an angle, and the length of the flat convex portion 22 of the gear plate 2 by an angle. And the length angle β
The length angle β is set to be larger (α <β). Specifically, the interval angle α was set to about 30 °, and the length angle β was set to about 40 °.

The operation will be described based on the above configuration. The gear plate 2 is rotated clockwise from the rotational position shown in FIG.
Is an angle range in which the inclination of the back seat can be adjusted and locked. That is, in this angular range A, the four lock gears 5, 6 are normally strongly pressed against the inner peripheral surface of the gear plate 2 via the cam 7 by the urging force of the spiral springs 8, 8, and the lock gears 5, 6 The external teeth 51, 61 mesh with the internal teeth 21 of the gear plate 2,
The gear plate 2 is locked. That is, the backseat 102 of the seat maintains the inclination angle. In the locked state, the torque applied to the gear plate 2 is reduced by 4
Since the lock gears 5, 6, 5, and 6 are used for the support, the lock strength is very high as compared with the support using the two lock gears. Further, since the two paired lock gears (5 and 5 and 6 and 6) are arranged at positions separated from each other by 180 °, the central component acting on the cam 7 at the time of locking can be offset, and the cam 7 The lock strength can be improved since no biased force is applied to the lock member.

The operation in the lockable angle range A will be described. When the occupant releases the lock to adjust the inclination angle of the back seat 102, the reclining operation lever 107 is pulled to rotate the center shaft 106.
Then, the cam 7 also rotates integrally. Referring to FIG. 2, when the cam 7 is rotated clockwise in the drawing against the urging force of the spiral springs 8, 8, the four lock gears 5, 6 can move radially inward. Teeth 21 and external teeth 51, 61
Is disengaged. At this time, the lever plate 9 also rotates integrally with the cam 7, and the inner peripheral edge of the cam hole 91 of the lever plate 9 comes into contact with the projections 52, 62 of the lock gears 5, 6, so that the lock gear 5,
6 is positively moved toward the center and disengaged. When the meshing is released, the rotation of the gear plate 2 becomes free, and the round reclining device is unlocked. When the round reclining device is unlocked, the reclining device is unlocked, and the tilt angle of the back seat 102 can be freely adjusted. When the adjustment is completed, the reclining operation lever 107 is loosened, so that the spiral spring 8,
The cam 7 rotates in the counterclockwise direction by the urging force of 8, and the cam 7 presses the lock gears 5 and 6 outward in the radial direction, so that the external teeth 51 and 61 of the lock gears 5 and 6 contact the internal teeth 21 of the gear plate 2. The gear plate 2 is engaged and locked.

The gear plate 2 is rotated counterclockwise from the rotational position shown in FIG.
The angle range B from when the external teeth 61 of the first gear rides on to when the flat convex portion 22 separates from the external teeth 51 of the lock gear 5 is an angle range in which the unlocking state continues to be unlocked. The angle range B is an angle range in which the back sheet 102 can be freely rotated by leaning forward.

The operation in the unlocked angle range B will be described. In a state where the reclining operation lever 107 is pulled and the lock gears 5 and 6 are retracted to be unlocked, the back sheet 102 is slightly tilted forward and the finger is released from the reclining operation lever 107. Then, gear plate 2
Is rotated slightly counterclockwise from the rotation position shown in FIG. 5, and one end of the external teeth 61 of one lock gear 6 rides on the end of the flat convex portion 22. Since the flat convex portion 22 is formed higher than the inner teeth 21, the lock gear 6 is kept pressed down in the radial center direction. For this reason, even when the finger is released from the reclining operation lever 107, the cam 7 cannot rotate according to the urging force of the spiral spring 8. Therefore, also
Since the cam 7 cannot be rotated, the lever plate 9 cannot be rotated, and the cam hole 91 remains engaged with the projections 52, 62 of the lock gears 5, 6, so that the other lock gears 5 can be engaged with the internal teeth 21 while being retracted. Unlocked state is maintained.

When the back sheet 102 is further tilted forward, the gear plate 2 rotates counterclockwise in FIG.
The flat convex portion 22 slides on the mountain of the external teeth 61 of the lock gear 6. Eventually, a part of the flat convex portion 22 separates from one lock gear 6 and reaches the external teeth 51 of another adjacent lock gear 5. At this time, the length angle β (about 40
°) is the interval angle α between the two lock gears 5 and 6 that are close to each other.
(About 30 °)
There is an overlapping region where the flat convex portion 22 bridges the interval angle α and pushes down the two lock gears 5 and 6. When the gear plate 2 is further rotated counterclockwise, the flat convex portions 2
2 is completely separated from one lock gear 6 and slides on the mountain of the external teeth 51 of the other lock gear 5 adjacent thereto. At this time, the lock gear 5 is pushed down in the radial center direction by the flat convex portion 22. Therefore, cam 7
Cannot rotate, and one lock gear 6 remains retracted. Therefore, the angle range B to be unlocked is the flat convex portion 2
2 is a wide range until completely separated from the external teeth 51 of the other lock gear 5.

The angle range C, which is the sum of the unlocking angle range B and the lockable angle range A, that is, the rotation allowable angle range C of the back seat, is a pair of lock gears (5 and 5 or 6). And 6) are arranged at a position 180 ° apart from each other, so that the maximum is 180 °.
In this way, it is possible to widen the permissible rotation range of the back seat up to 180 ° while increasing the reclining strength by using the four lock gears 5 and 6 and securing the angle range B for unlocking. became. Actually, the maximum allowable rotation range is 180 by a stopper member (not shown).
The rotation angle is limited within the range of °, and the rotation is set to a permissible rotation range according to the vehicle type to be used.

FIG. 6 is an explanatory diagram showing the relationship between the shapes of the lock gears 5, 6 and the shapes of the guide projections 11, 12, 13. As shown in FIG.
The guide projections 11, 12, 13 are formed integrally with the base plate 1 by press molding. The two lock gears 5 and 6 have a spacing angle D between the centers of their external teeth 51 and 61.
Are arranged close to each other so as to be about 60 °. Each lock gear 5, 6 has the same shape.

That is, one side 5A of the two sides extending from the external teeth 51 of the lock gear 5 to the rear end is the external teeth 51A.
From the left end to the rear end in parallel with the sliding direction of the lock gear 5. The other side 5B is narrowed from the right end of the external teeth 51 and narrowed, and then linearly reaches the rear end in parallel with the sliding direction of the lock gear 5. The distance a from the center line of the external teeth 51 to one side 5A is different from the distance b from the center line to the other side 5B (a> b).
Has an asymmetric shape. Similarly, the other lock gear 6 has one side 6A which linearly extends from the left end of the external teeth 61 to the rear end and the other side which narrows from the right end of the external teeth 61 to reach the rear end. 6B, and the distance a and the distance b from the center line are different (a> b).

The two lock gears 5 and 6 are guided by linear guide portions on the side peripheral portions of the three guide projections 11, 12 and 13, and are slidable in the radial direction. A long guide portion of the guide protrusion 11 slides on the long side 5A on the left side of the lock gear 5, and a short guide portion of the guide protrusion 12 slides on the short side 5B on the right. Similarly, in the lock gear 6, a long guide portion of the guide projection 12 slides on the left long side 6A, and a short guide portion of the guide projection 13 slides on the right short side 6B. A cam 7 for pressing the lock gears 5 and 6 is provided at the rear end of each lock gear 5 and 6.
Comes into sliding contact.

The operation based on the above configuration will be described. As shown in FIG. 6, the two lock gears 5 and 6 have an asymmetric shape, and the width (a + b) near the rear end is equal to the outer teeth 5.
Since the width of the lock gears 5 and 6 is smaller than the width of the lock gears 1 and 61, even if the interval angle D between the two lock gears 5 and 6 is set to a narrow space of about 60 °, the rear ends of the lock gears 5 and 6 that are close to each other at the time of unlocking can be obtained. It does not interfere with each other. At the time of unlocking, since it has an asymmetric shape, the rear end of the lock gear 5 is shaped to go under the rear end of the lock gear 6, and interference of the rear end can be prevented. Therefore, it is possible to arrange the four lock gears 5, 6, 5, 6 at non-quadrant positions without reducing the number of external teeth 51, 61.

Next, the lock strength at the time of locking will be considered. This is a case where a torque load is applied to the gear plate 2 in a state where the external teeth 51 and 61 are engaged with the internal teeth 21 of the gear plate 2. In FIG. 6, it is assumed that a torque load is applied to the gear plate 2 in the counterclockwise rotation direction. In the lock gear 5, a counterclockwise torque load is supported by the left longer side 5A. To be more precise, since a rotational moment acts on the lock gear 5, the support point near the external teeth 51 on the left side 5A of the lock gear 5 and the right side 5B shown by a mark in FIG. The bearing is supported by the effective length L determined by the support point near the end, that is, the effective length L of the guide portion of the guide projection 11. Since the effective length L is sufficiently long, it shows a sufficiently high lock strength. The same can be said for the lock gear 6, and the effective length of the guide portion on the right side of the guide convex portion 12 can be ensured to be sufficiently long.

As described above, when a torque load is applied to the gear plate 2 in the counterclockwise rotation direction, the effective length of the guide portion can be ensured to be sufficiently long, and the outer teeth 51, 61 of the lock gears 5, 6 can be secured. 600Kg-m because the total number of teeth can be ensured, the number of lock gears 5 and 6 is 4, and the number of guide portions supporting them is also 4.
The very high lock strength described above could be achieved. On the other hand, when a torque load in the clockwise direction in FIG. 6 is applied to the gear plate 2, the effective length of the guide portion is shorter than that in the counterclockwise direction because the right side portions 5B and 6B are short. The lock strength becomes weaker as compared with the counterclockwise direction. However, the conditions other than the effective length of the guide portion, the total number of the external teeth 51 and 61 and the number of the lock gears 5 and 6 are the same, so that the lock gear is 2
It was possible to obtain a sufficiently high lock strength as compared with a single conventional reclining device. And the right side 5B,
By appropriately setting the length of 6B, it was possible to obtain the necessary and sufficient clockwise lock strength required by the vehicle type. In addition, the number of parts is only two lock gears and the weight is slightly increased as compared with the conventional one.

Therefore, if the counterclockwise rotation direction of the gear plate 2 is set to the direction in which the back seat 102 is tilted forward,
Even with a shoulder-belt-incorporated seat having an upper support point for the seatbelt at the upper side of the backseat 102, a high-strength reclining device that can sufficiently withstand an emergency such as a frontal collision of an automobile can be provided. Even in the case of a rear collision of an automobile, a reclining device having not only an excessively high strength but also a necessary and sufficient lock strength required by a vehicle type could be obtained.

[0044]

As described above, according to the first aspect of the present invention, the length angle (β) of the flat convex portion is larger than the interval angle (α) of the adjacent lock gears. The number of locks is four, and while the lock strength is greatly improved, the range of angles to be unlocked can be widened so that the back seat can be moved forward and applied to two-door vehicles and RV vehicles. Has an excellent effect. In addition, the number of parts and the weight are slightly increased as compared with the improvement of the lock strength, so that there is an effect that it is possible to satisfy a demand for an automobile part such as weight reduction and cost reduction.

According to the second aspect of the present invention, the effective length (L) of the guide portion for supporting the torque load in one direction without reducing the number of teeth by making the shape of the lock gear asymmetrical.
And the lock strength has been improved, so that it is possible to apply a sufficient margin to a seat that may be subjected to an abnormally high torque load in only one direction, such as a seat with a built-in shoulder belt. It has a remarkable effect. Further, since the shape of the lock gear is asymmetric, even if adjacent lock gears are retracted due to unlocking, they do not interfere with each other. For this reason, there is an effect that it is easy to increase the number of lock gears and to easily improve the lock strength.

[Brief description of the drawings]

FIG. 1 is a side view showing a seat on which a reclining device according to the present invention is mounted.

FIG. 2 is a partially cutaway plan view showing a round reclining unit of the reclining device.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is an explanatory diagram showing the relationship between the arrangement of the lock gear and the internal teeth and flat protrusions of the gear plate.

FIG. 6 is an explanatory diagram showing the relationship between the shape of a lock gear and the shape of a guide projection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base plate 11-13 Guide convex part 2 Gear plate 21 Internal tooth 22 Flat convex part 5 Lock gear 51 External tooth 6 Lock gear 61 External tooth 7 Cam 8 Spiral spring

Claims (2)

[Claims] 1. A base plate, a gear plate rotatably mounted on the base plate and having internal teeth, and an outer gear that is mounted to be guided by the base plate so as to be movable only in the radial direction and meshes with the internal teeth of the gear plate. A plurality of lock gears having teeth, a cam for controlling the outward movement of the lock gear in the radial direction and meshing the lock gear with the internal teeth of the gear plate, and urging the cam in a direction for meshing the lock gear with the internal teeth; A spring, a center shaft capable of rotating the cam against the urging force of the spring by rotating through the non-circular center hole of the cam to release the engagement between the lock gear and the gear plate, In the reclining device, the gear plate has a lock gear mounted on the same circumference as the internal teeth at a height higher than the internal teeth. Raised flat protrusions are partially formed, and the internal teeth and the flat protrusions are alternately continued. Four lock gears are prepared, and a pair is formed for every two lock gears. The two lock gears in each pair are 1
80 ° apart, while the different pairs of lock gears are arranged in non-quadrant positions that are not perpendicular to each other, and outside the two adjacent lock gears of the four lock gears. A length angle (β) of the flat convex portion is made larger (α <β) than an interval angle (α) between the teeth and the external teeth. 2. A base plate, a gear plate rotatably mounted on the base plate and having internal teeth, and an external gear rotatably movable only in the radial direction and guided by the base plate and engaged with the internal teeth of the gear plate. A plurality of lock gears having teeth, a cam for controlling the outward movement of the lock gear in the radial direction and meshing the lock gear with the internal teeth of the gear plate, and urging the cam in a direction for meshing the lock gear with the internal teeth; A spring, a center shaft capable of rotating the cam against the urging force of the spring by rotating through the non-circular center hole of the cam to release the engagement between the lock gear and the gear plate, The shape of the lock gear is one of two sides from the external teeth to the rear end. Whereas in parallel to reach the rear end and the sliding direction of the linearly lock gear from the edge of the external teeth,
A reclining device characterized in that the other side has an asymmetric shape that narrows from the end of the external teeth and becomes narrower, and then linearly reaches the rear end in parallel with the sliding direction of the lock gear. .