JPH0716351Y2 - Reclining device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a reclining device for a vehicle seat or the like.

(Prior Art) As one type of reclining device, as shown in the publication "Automotive Engineering Handbook, Vol. 6, page 26" (published by the Society of Automotive Engineers of Japan), a lower arm supporting a seat cushion and a rear portion of the lower arm. An upper arm that is tiltable in the front-back direction and is spring-biased forward to assemble to support the seat back; and a ratchet that is fixedly provided on one of these arms and has a plurality of teeth in an arc shape. A pole having a plurality of tooth portions swingably provided on the other of both arms and meshing with the ratchet so as to be engageable with and disengageable from the arm, pressing means for elastically meshing the pole with the ratchet, and meshing of the pole with the ratchet. There is a reclining device provided with a release lever for releasing.

Therefore, in this type of reclining device, as shown in FIG. 4, the ratchet 1 is provided with a tooth portion forming portion 1a having a large number of tooth portions formed in an arc shape and an arc surface portion 1b continuing from the tip thereof. On the other hand, a plurality of tooth portions of the pole 2 are formed in an arc shape having the same radius of curvature as that of the tooth portion so as to surely mesh with the tooth portion of the ratchet. Further, the arcuate surface portion 1b of the ratchet 1 is formed to have a diameter slightly larger than that of the tooth portion forming portion 1a. Therefore, when the upper arm is rotated to the maximum forward, the tooth top surface of the tooth portion 2a (referred to as the first tooth portion) on the base end side of the pole 2 repels the arc surface portion 1b of the ratchet 1. When the upper arm is gradually rotated rearward, the first tooth portion 2a of the pole 2 comes out of the same portion 1b while slidingly contacting the arc surface portion 1b, and at the same time, the second tooth portion 2b.
Slides on the same portion 1b and is disengaged from the same portion 1b, and finally the tooth portion 2c on the swinging end side is disengaged from the portion 1b, so that the pole 2 meshes with the tooth portion of the ratchet 1.

(Problems to be Solved by the Invention) By the way, just before the pole 2 meshes with the ratchet 1, the tooth crest surface of the first tooth portion 2a of the pole 2 becomes the tooth crest surface of a certain tooth portion of the ratchet 1. When the first tooth portion 2a is elastically abutted and comes off while slidingly contacting the tooth top surface of the tooth, it meshes with the tooth portion of the ratchet 1. For this reason, when the upper arm is swung quickly, the pole 2 jumps over one or more tooth portions of the ratchet 1 and a so-called tooth jump phenomenon occurs in which the ratchet 1 meshes with the ratchet 1. A reclining device to deal with this is disclosed in Japanese Utility Model Publication No. 55-111460. In the reclining device, the tooth length of each tooth portion of the pole is sequentially increased from the tooth portion on the base end side thereof, and immediately after the tooth portion on the swinging end side of the pole is disengaged from the arc surface portion of the ratchet. The pole is configured to positively mesh with a part of the tooth portion of the ratchet. Thereby, in the reclining device, the occurrence of the tooth jump phenomenon is suppressed. However, in the reclining device, the meshing state of the tooth portion of the pole with the tooth portion of the ratchet gradually becomes shallower from the swing end side of the pole to the base end side, which is a great concern for the meshing strength.

Therefore, an object of the present invention is to provide a reclining device having sufficient engagement strength of a pole with a ratchet and free from tooth jumping phenomenon.

(Means for Solving the Problem) The present invention provides a lower arm that supports a seat cushion,
An upper arm that is tiltable in the front-rear direction and is spring-biased forward to be attached to the rear portion of the lower arm to support the seat back, and a plurality of teeth that are fixedly provided on one of these arms and have an arc shape. A ratchet, a pole having a plurality of tooth portions swingably provided on the other of the both arms and engaging with the ratchet so as to be engageable with and disengaged from the arm, and pressing means for elastically meshing the pole with the ratchet. In a reclining device including a release lever for releasing engagement with a ratchet, a tooth tip top surface of one tooth portion of a plurality of tooth portions of the pawl on the base end side of the pawl is attached to the tooth portion of the ratchet. It is characterized in that it is formed in a taper shape that gradually separates from the tooth top surface toward the swing end side of the pawl in the state of contacting with the tooth top surface. That.

(Operation / Effect of the Invention) In the reclining device having such a configuration, the tooth portion on the base end side of the pole (corresponding to the above-mentioned first tooth portion)
The tooth top surface of is formed in the above-described tapered shape, and the tooth top surface of the tooth portion of the pole immediately after the pole comes off the ratchet is in sliding contact with the tooth top surface of one tooth portion of the ratchet, During this time, the pole is closer to the ratchet compared to the conventional one. Therefore, the pole is very likely to mesh with the ratchet immediately after it is disengaged from the tooth portion of the ratchet, and the tooth skipping phenomenon is unlikely to occur even if the upper arm is swung quickly.

Further, in the reclining device, since the tooth top surface of only the tooth portion on the proximal end side of each tooth portion of the pole is formed only in a specific taper shape, the tooth jumping phenomenon of the pole occurs. Not only is it prevented, but at the meshing part with the ratchet, the meshing of only one tooth on the base end side of the pole is shallow, and the means for preventing the tooth jump phenomenon is the ratchet of the pole. Does not affect the mating strength with respect to. Therefore, in the reclining device, the meshing strength of the pole with the ratchet is sufficiently high and reliable.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a reclining device according to an embodiment of the present invention. The reclining device 10 includes a lower arm 11 which is erected on an upper rail 21 of a seat track 20, an upper arm 12 which is rotatably attached to a rear portion of the lower arm 11 in a front-rear direction, and an upper arm 12 which is provided between the both arms 11.
Ratchet 13 and lower arm 11 mounted so as to rotate together with
A release lever 15 and a cam plate 16 integral with the release lever 15, and a tension spring 17 for biasing the release lever 15 counterclockwise in the drawing. And upper arm
It has a torsion spring 18 that biases 12 forward.

In the reclining device 10, as shown in FIG. 2, the ratchet 13 includes a tooth portion forming portion 13a having a large number of tooth portions formed in an arc shape and an arc surface portion 13b continuing from the tip thereof, and the pole 14 is The ratchet 13 has a plurality of teeth that mesh with the teeth of the ratchet 13. The release lever 15 is biased by a tension spring 17, and the pole 14 of the ratchet 13 is moved by the action of an engagement pin 14a provided on the cam groove 15a provided on the lever 15 and the pole 14 and facing the cam groove 15a. The cam plate 16 is meshed with the teeth, and the cam plate 16 presses the back of the pole 14 to maintain the meshed state. In this state, when the release lever 15 is rotated against the tension spring 17, the cam plate 16 rotates integrally with the lever 15 and separates from the back portion of the pole 14, and at the same time, the engagement pin 14a and the cam groove are formed. The pole 14 is separated from the ratchet 13 by the action with 15a. Therefore, the lock of the upper arm 12 with respect to the lower arm 11 is released, the upper arm 12 and the ratchet 13 integrated with the upper arm 12 are rotatable in the front-rear direction, and the inclination angle of the upper arm 12 is adjusted. When the upper arm 12 is rotated to the maximum by the action of the torsion spring 18, the teeth of the pole 14 are located on the arc surface of the ratchet 13.
Abut on 13b.

Thus, in the reclining device 10, as shown in FIGS. 2 and 3, the arc surface portion of the ratchet 13 is
13b is formed to have a diameter slightly larger than that of the tooth portion forming portion 13a, and in order that the pole 14 meshes with the ratchet 13, both tooth portion forming portions are formed in an arc shape having the same radius of curvature. Therefore, when the upper arm 12 is rotated to the maximum forward, the tooth portion 14b ₁ on the base end side of the pole 14 is
(Hereinafter referred to as the first tooth portion, which is referred to as the second tooth portion, the third tooth portion ... in sequence toward the swinging end portion), the top surface of the tooth tip elastically abuts the arc surface portion 13b of the ratchet 13. ing. Meanwhile, Paul 14
In the contact with the tooth tip top surface of the teeth 13c of the first tooth portion 14b ₁ of the addendum top surface ratchet 13, the tooth tip of the tooth portion 13c of the ratchet 13 toward the oscillating end portion of the pole 14 It is formed in a tapered shape that gradually separates from the top surface. That is, the first tooth portion
14b ₁ has a shape in which the hatched portion shown in FIG. 3 is removed as compared with the conventional first tooth portion.

Therefore, when the upper arm 12 is rotated to the front from the maximum rotated state, the ratchet 13 is rotated integrally with the upper arm 12, and the tooth tip of the first tooth portion 14b ₁ in the pole 14 is an arc surface of the ratchet 13. While sliding the part 13b, it comes off from the part 13b,
At the same time, the tooth tip of the second tooth portion 14b ₂ comes off the portion 13b while slidingly contacting the same portion 13b, and finally the fourth tooth portion 14b ₄ on the swinging end side comes off the portion 13b and the pole 14 becomes the ratchet 13 Mesh with. During this period, immediately after the fourth tooth portion 14b ₄ of the pole 14 comes off the arc surface portion 13b of the ratchet 13,
While the addendum top surface of the tooth portion 14b ₁ slides over the tooth tip top face of one tooth portion 13c of the ratchet 13, the addendum top surface of the first tooth portion 14b ₁ is formed in a tapered state as shown in FIG. 3 Because the first tooth
During the sliding contact of 14b ₁ , the pole 14 comes closer to the ratchet 13 as compared with the conventional device. Because of this, Paul 14 is a ratchet
Immediately after the tooth 13 is disengaged from the tooth portion 13c, the ratchet 13 is brought into a state in which it is extremely easy to mesh with the tooth 13 and the tooth skipping phenomenon is unlikely to occur even if the upper arm 12 is swung quickly.

By the way, in the reclining device 10, the tooth top surface of only the first tooth portion 14b1 which is the tooth portion on the base end side among the tooth portions of the pole 14 is formed only in a specific taper shape. At the meshing portion with the ratchet 13, only the first tooth portion 14b1 of the tooth portions of the pole 14 is in a shallow meshing state. Therefore, in the reclining device 10, such a means for preventing the tooth skipping phenomenon does not affect the meshing strength of the pawl 14 with respect to the ratchet 13, and the meshing strength of the pawl 14 with respect to the ratchet 13 is sufficiently high, so that it is reliable. Will be available.

[Brief description of drawings]

FIG. 1 is a front view of a reclining device according to an embodiment of the present invention, FIG. 2 is a partially enlarged view showing a relationship between a ratchet and a pole in the device, and FIG. 3 is an enlarged view of an arrow III portion in FIG. 4 and 5 are partial enlarged views corresponding to FIG. 2 in the conventional device. Explanation of code 10 …… Recliner, 11 …… Lower arm, 12 ……
Upper arm, 13 ... Ratchet, 13a ... Tooth part forming part, 13b ... Arc surface part, 13c ... Tooth part, 14 ... Pole,
14b ₁ ...... 1st tooth (base end side tooth), 14b ₄ ...... 4th tooth (oscillation end side tooth), 15 ...... release lever, 17 ...... tension spring, 18 ...... Torsion spring.

Claims (1)

[Scope of utility model registration request] 1. A lower arm that supports a seat cushion, an upper arm that is tiltably movable in the front-rear direction at the rear portion of the lower arm and is spring-biased forward to be installed to support a seat back, and is fixed to one of these two arms. And a pole having a plurality of tooth portions that are provided in a circular arc shape and a plurality of tooth portions that are swingably provided on the other of the two arms and that are removably screwed into the ratchet, and the same pole. Pressing means for elastically meshing with the ratchet,
In a reclining device including a release lever for releasing engagement with the ratchet, a tooth tip top surface of one tooth portion of a plurality of tooth portions of the pawl on a base end side of the pawl is provided with a tooth portion of the ratchet. The reclining device is formed in a taper shape that gradually separates from the tooth top surface toward the swing end side of the pole in the state of contacting with the tooth top surface.