JPH06253950A - Lumber support apparatus - Google Patents

Abstract

PURPOSE:To provide a lumbar support apparatus which has two supporting positions by eliminating a feeling of incongruity and hitting the bottom using a torsion bar. CONSTITUTION:A torsion bar 5 is bent vertically with the center line A of the rotation thereof as reference to form a pair of flat parts 51 and 52 and the back part of a person seated is supported by the flat parts.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lumbar support device having two support positions.

[0003]

2. Description of the Related Art Conventionally, as this type of lumbar support device, the one disclosed in Japanese Utility Model Laid-Open No. 58-149954 is known. This is a bell crank that is rotatably supported by the seat back frame, an upper support member that is supported at one end of the bell crank and supports a slightly upper part of the back of the seated person, and a seat supported by the other end of the bell crank. A lower support member that supports a slightly lower part of the back of the person,
And a drive mechanism linked to the bell crank. In this conventional device, the upper support member is moved in the seat back thickness direction by the one-way rotation of the bell crank due to the operation of the drive mechanism, whereby the back part of the occupant is pressed by the upper support member and the upper portion is pressed. A support feeling is obtained by the support member, and the lower support member is moved in the thickness direction of the seat back by the rotation of the bell crank in the other direction, whereby the back support of the seated person is pressed by the lower support member and the lower support member is pressed. The support feeling of the member was obtained.

[0004]

However, in the lumbar support device described above, since there is no elastic member in the support system of the upper and lower support members, a feeling of foreign matter at the time of support can be obtained by the support of the upper and lower support members. It was impossible to eliminate the bottoming feeling at the time of neutral when the support feeling due to the upper and lower support members is eliminated.

Therefore, it is a technical object of the present invention to provide a lumbar support device having two support positions in which a feeling of foreign matter and a feeling of bottoming are eliminated by using a torsion bar.

[0006]

[Constitution of the invention]

[0007]

In order to solve the above-mentioned technical problems, the technical means taken in the present invention is arranged in a seat back, one end of which is rotatably supported by a seat back frame and the other end of which is driven. It has a torsion bar linked to the mechanism, and the torsion bar has a pair of flat portions bent and formed in the up-down direction of the seat back on the basis of the rotation center line.

[0008]

According to the above technical means, two support positions can be obtained by the flat portion of the torsion bar. Therefore, it has two support positions in which the feeling of foreign matter and the feeling of bottoming are eliminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the lumbar mechanism 1 is arranged in a seat back 3 which constitutes one part of the seat 2 and supports the back of the seated person, and applies a pressing force to the back of the seated person. It improves the sitting comfort.

As shown in FIGS. 2 and 3, the lumbar mechanism 1 is composed of a drive mechanism 4 and a torsion bar 5.

The drive mechanism 4 is fixedly arranged on one side frame (not shown) of the seat back 3 via a bracket 6. The drive mechanism 4 includes a motor 41, a speed reduction mechanism 42 including a plurality of gears, a pinion gear 43, and a sector gear 44. The motor 41 and the speed reduction mechanism 42 are fixed to the bracket 6, and the pinion gear 4
3 is fixed to the output shaft 42a from the reduction mechanism 42. The sector gear 44 is rotatably supported on the bracket 6 by a pin 45, and meshes with the pinion gear 43. The sector gear 44 is provided with mounting holes 44a and 44b in which the torsion bar 5 is locked.

The torsion bar 5 is arranged across the width of the seat back 3. One end 5a of the torsion bar 5 is rotatably supported on the other side frame (not shown) of the seat back 3 coaxially with the pin 45, and the other end 5b is inserted into the mounting holes 44a and 44b to be inserted into the sector gear 4.
It is locked to 4. Further, the torsion bar 5 is bent upward and downward with reference to the rotation center axis line A, and flat portions 51 and 52 are formed. An upper support plate 7 and a lower support plate 8 are fixed to the torsion bar 5 in such a manner that they are supported by the flat portions 51 and 52, respectively.

Next, the operation will be described.

FIG. 4 shows a neutral state in which the lumbar mechanism 1 is not functioning, that is, no pressing force is applied to the back of the seated person. In this neutral state, the urging force is applied to the upper support plate 7 and the lower support plate 8 by the torsion bar 5,
Even if the seated person leans against the seat back 3 and does not feel any bottoming.

In this neutral state, the motor 4
When 1 operates in one direction, the sector gear 44 rotates about the pin 45 in one direction (counterclockwise direction in FIG. 3) via the reduction mechanism 42 and the pinion gear 43. As a result, the torsion bar 5 pivots in one direction (counterclockwise in FIG. 3), the flat portion 51 moves to the front side in the thickness direction of the seat back 3, and the upper support plate 7 pushes it against the seated person as shown in FIG. Pressure is applied (first support state in which the lumbar mechanism 1 is functioning). When the motor 41 operates in the other direction, the sector gear 44 rotates in the other direction (clockwise in FIG. 3) about the pin 45 via the reduction mechanism 42 and the pinion gear 43. As a result, the torsion bar 5 rotates in the other direction (clockwise in FIG. 3) and the flat surface portion 52 moves to the front side in the thickness direction of the seat back 3, and the lower support plate 8 presses the seated person as shown in FIG. Is given (the second support state in which the lumbar mechanism 1 is functioning).
This 1. Even in the second support state, the urging force is applied to the upper support plate 7 and the lower support plate 8 by the torsion bar 5, so that the seated person leans against the seat back 3 and does not feel a foreign object.

As shown in FIGS. 7 and 8, the motor 4
1 and the deceleration mechanism 42, a well-known spring cutting mechanism 47 that constitutes an operation handle 46 and a reverse rotation preventing mechanism.
May be In this case, the operation handle 46 is fixed to the driving member 47a side of the spring cutting mechanism 47, and the pinion gear 43 is fixed to the driven member 47b side of the spring cutting mechanism 47. Other configurations are the same as those in the above-mentioned embodiment.

[0018]

According to the present invention, two support positions can be obtained by the flat portion of the torsion bar. This makes it possible to provide a lumbar support device having two support positions in which the feeling of foreign matter and the feeling of bottoming are eliminated.

[Brief description of drawings]

FIG. 1 is a perspective view of a seat adopting a lumbar support device according to the present invention.

FIG. 2 is a plan view of a lumbar support device according to the present invention.

FIG. 3 is a side view of FIG.

FIG. 4 is a sectional view taken along line BB in FIG. 1 showing the operation of the lumbar support device according to the present invention.

5 is a sectional view taken along line BB in FIG. 1 showing the operation of the lumbar support device according to the present invention.

FIG. 6 is a cross-sectional view taken along line BB in FIG. 1 showing the operation of the lumbar support device according to the present invention.

FIG. 7 is a partial plan view corresponding to FIG. 2 showing a modified example of the drive mechanism.

FIG. 8 is a side view of FIG. 7.

[Explanation of symbols]

 1 Lumber mechanism (Lumber support device) 3 Seat back 4 Drive mechanism 5 Torsion bar A Rotation center line 51.52 Plane

Claims (1)

[Claims] 1. A seat bar having one end rotatably supported in a seat back frame and rotatably supported by a seat back frame and the other end linked to a drive mechanism, the seat bar up and down with respect to a center line of the rotation. A lumbar support device having a pair of flat portions bent in the direction.