JP3142164B2 - Reclining device for vehicle seat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat reclining device.

[0002]

2. Description of the Related Art Generally, a reclining device for a vehicle seat is provided with a lower arm fixed to a seat cushion and a lower arm in the front-rear direction, as described in a publication "New Edition of Automotive Engineering Handbook, Vol. 6, page 26". Equipped with an upper arm that is movably mounted to support the seat back, a ratchet is provided integrally with the upper arm, and a pole provided on the lower arm side is detachably engaged with the ratchet so that the upper arm can be released from the lower arm. It is configured to lock.

[0003]

The above-mentioned conventional reclining device requires gear-working parts such as a ratchet and a pole, so that the structure is complicated, and it is difficult to reduce the weight and thickness. Also, backlash occurs between the ratchet and the pole, resulting in a poor operation feeling. Further, the reclining angle of the seat back, that is, the minimum adjustment amount of the inclination angle of the seat back with respect to the seat cushion is determined by the pitch of the ratchet teeth, and cannot be adjusted steplessly. The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle seat reclining device that can be easily reduced in weight and thickness and that can adjust a reclining angle steplessly.

[0004]

SUMMARY OF THE INVENTION A reclining device for a vehicle seat according to the present invention includes a lower arm fixed to a seat section, an upper arm rotatably mounted in the front and rear direction to the lower arm, and a lower arm for supporting a seat back. Around the rotation center of the upper arm between the upper arms
A friction member having a piezoelectric effect interposed and frictionally engaged with the opposing surfaces of these arms , and a pulse generating means for generating a pulse train driving voltage applied to the friction member are provided. It is assumed that.

[0005]

According to this structure, when no drive voltage is applied to the friction member having the piezoelectric effect, the upper arm is restrained with respect to the lower arm by the frictional resistance between the member and the two arms. Does not rotate in the front-back direction. On the other hand, when a pulse train drive voltage is applied to the friction member having the piezoelectric effect, the member is contracted due to distortion generated by the piezoelectric effect. For this reason, the frictional resistance between the friction member having the piezoelectric effect and the two arms is reduced, so that the upper arm can rotate in the front-rear direction. Therefore, the reclining angle can be adjusted by applying a front-back force to the seat back.

According to the present invention, since the rotation of the seat back is regulated by utilizing the piezoelectric inverse effect of the friction member having the piezoelectric effect interposed between the two arms, complicated gears such as ratchets and pawls are provided. No need for machined parts. Therefore, the structure is extremely simple, and the reclining angle can be adjusted steplessly.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a reclining device according to an embodiment of the present invention; FIG. FIG. 3 shows a vehicle seat S provided with the device 10. The reclining device 10 includes a lower arm 11 fixed to the rear end of the seat cushion SC and an upper arm 12 fixed to the lower end of the seat back SB. The upper arm 12 can be pivotally moved in the front-rear direction by the stepped bolt 13. The reclining angle can be adjusted by rotating the seat back SB in the front-rear direction. Since the stepped bolt 13 has a slit 13a at the tip end, the inner end of the spiral spring 14 is locked by the slit 14a, and the outer end is locked by the hook plate 15 welded to the upper arm 12, so that the seat back The SB is urged forward by the spiral spring 14.

A friction ring 16 made of a material having a piezoelectric effect (hereinafter referred to as a piezoelectric material) is interposed between the lower arm 11 and the upper arm 12, a washer 17 is inserted into a stepped bolt 13, and a lock nut 18 is used to connect the upper arm to the upper arm. Of 1
2 and the lower arm 11 are pressed together.
It is tightened between 1 and 12. This friction ring 16
Polycrystalline ceramic piezoelectric materials such as BaTiO ₃ , PbZrO ₃ , PbTiO ₃ , and composite materials obtained by adding rubber to these powders are used. Further, as shown in FIG. 4, the friction ring 16 is connected to a pulse generator 19 that generates a driving voltage in the form of a square pulse train. When the reclining switch 20 provided on the side of the seat cushion SC is turned on, During that time, a drive voltage is applied.

In this embodiment, when the reclining switch 20 is off and no drive voltage is applied to the friction ring 16, the friction ring 16 and the arms 11, 1
Since the upper arm 12 is restrained with respect to the lower arm 11 by the frictional resistance between the two, the seat back SB does not rotate in the front-rear direction.

When the reclining switch 20 is turned on, a driving voltage in the form of a square pulse train is applied to the friction ring 16, so that the friction ring 16 is distorted due to a piezoelectric inverse effect. Therefore, the friction ring 16 and both arms 1
Since the frictional resistance between the upper arm 1 and the upper arm 12 is reduced.
2 can be rotated in the front-rear direction. Thus, if a force is applied to the seat back SB against the force of the spiral spring 14, the seat back SB can be rotated in the front-rear direction to adjust the reclining angle. When the reclining switch 20 is turned off, the distortion of the friction ring 16 disappears and the friction ring 16 expands.
Since the frictional resistance between the friction rings 1 and 12 and the friction ring 16 increases, the seat back SB does not rotate.

As described above, according to the present embodiment, both arms 1
Since the rotation of the seat back SB is regulated by utilizing the piezoelectric reversal effect of the friction ring 16 made of a piezoelectric material interposed between 1 and 12, a complicated gear machining part such as a ratchet or a pole is not required. This makes the structure very simple,
The apparatus can be made thinner and lighter, the reclining angle can be adjusted steplessly, and there is no backlash, so that a good operational feeling can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a reclining device according to one embodiment of the present invention.

FIG. 2 is an assembled sectional view showing the device.

FIG. 3 is a perspective view showing a vehicle seat provided with the device.

FIG. 4 is a block diagram showing a functional configuration of the device.

[Description of References] 10 ... Reclining device, 11 ... Lower arm, 12 ...
Upper arm, 13: Stepped bolt, 14: Spiral spring, 15: Hook plate, 16: Friction ring, 17: Washer, 18: Lock nut, 19: Pulse generator, 20: Reclining switch, S: Vehicle seat, SC ... Seat cushion, SB ... Seat back.

Claims (1)

(57) [Claims] A lower arm fixed to the seat section; an upper arm rotatably mounted in the front and rear direction on the lower arm to support a seat back; and a lower arm interposed between the lower arm and the upper arm.
Friction member, and that the vehicle seat reclining device according to claim which comprises a pulse generating means for generating a pulse train-like drive voltage to be applied to the friction member having a piezoelectric effect of frictionally engage the opposite faces of Luo each arm .