JPH0734625Y2 - Seat device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a seat device capable of arbitrarily changing the spring constant of a spring that imparts cushioning properties.

[Prior Art] For example, in a vehicle seat back, a lumbar support device is used in order to adjust a supporting force of a lumbar portion (lumbar vertebra portion) of a seated person. A conventional lumbar support device includes a spring body that receives a load from the lumbar portion and a support plate that is directly or indirectly attached to the spring body, and the spring body can be adjusted to a front-back position with respect to the seat back frame. It is installed and configured. The position of the spring body is adjusted by operating a dial provided on the side surface of the seat back or the like. By this dial operation, the spring force of the spring body is adjusted, and the strength of the support force is adjusted.

[Problems to be Solved by the Invention] In the lumbar support device described above, since the support force is adjusted by adjusting the position of the spring body, it is necessary to mount the spring body in a movable state on the seat back frame. Not only is it complicated and complicated to assemble, but strengthening the support force pushes up the cushion pad and changes the external shape, which is a design problem. Further, there is a problem that it is difficult to obtain a desired support force when there is a mounting error or a dimensional error. The present invention has been made in consideration of such circumstances, and it is possible to adjust the support force with a simple structure by adjusting the spring constant without adjusting the position of the spring body. The present invention aims to provide a new seat device.

[Means for Solving the Problems] In order to achieve the above object, the present invention has a torsion bar having both ends attached to a seat frame so as to be twistable and rotatable, and is attached so as to impart a torsional rotation to the torsion bar. A load receiver at the time of sitting, an adjusting member that is inserted through the torsion bar in a state where the relative rotation of the torsion bar is restrained and moves in the longitudinal direction of the torsion bar, and an operating member that moves the adjusting member. It is characterized by

[Operation] In the above configuration, the adjusting member moves in the longitudinal direction of the torsion bar by the operation of the operating member, so that the effective length of the torsion bar changes and the spring constant is adjusted.

[Embodiment] FIGS. 1 and 2 show an embodiment in which the present invention is applied to a lumbar support portion of a seat back. A pair of brackets 1 are attached to appropriate members of the seat frame 9,
A torsion bar 3 is stretched over the bracket 1. The torsion bar 3 has a rectangular cross section, and both ends of the torsion bar 3 are rotatably inserted into the bracket 1 and each insertion end is retained. A proximal end side of a moment arm 8 is attached to the torsion bar 3, and a load receiver 7 that abuts against the lumbar portion of a seated person and receives the load is attached to the distal end side of the moment arm 8. In such a structure, the load acting on the load receiver 7 is transmitted to the torsion bar 3 via the moment arm 8 and imparts torsional rotation to the torsion bar 3.

Reference numeral 2 is an adjusting member in which the torsion bar 3 is inserted. The adjusting member 2 is slidably attached to a guide rail 4 that is stretched between the brackets 1. In this case, the guide rail 4 is stretched between the brackets 1 so as to be parallel to the torsion bar 3, and the torsion bar 3 is inserted through the adjusting member 2, so that the adjusting member 2 can be moved by the torsion bar 3. It is designed to move in the longitudinal direction. The insertion hole of the torsion bar 3 in the adjusting member 2 has a rectangular shape similar to the cross section of the torsion bar 3, and the adjusting member 2 and the torsion bar 3 are provided.
Mutual rotation is restrained. And the adjusting member 2
Is attached to the guide rail 4 in a non-rotatable state with respect to the guide rail 4, so that the insertion portion of the adjusting member 2 in the torsion bar 3 does not rotate.

6 is a rack attached to the adjusting member 2 so as to be parallel to the torsion bar 3, 5 is a pinion attached to the bracket 1 on one side so as to mesh with this rack, and 10 is attached to the shaft of this binion 5. Dials for rotating the pinion 5, which are operating members for moving the adjusting member 2 in the longitudinal direction of the torsion bar 3. Reference numeral 11 in the drawing denotes a metal fitting for mounting the load receiver 7.

In the above configuration, when the dial 10 is rotated in the forward and reverse directions, the adjusting member 2 moves in the longitudinal direction of the torsion bar 3.

This movement changes the effective length of the torsion bar 3 to which the moment arm 8 is attached, so that the spring constant of the torsion bar 3 changes. That is, the angular displacement of the torsion bar 3 with respect to the load on the moment arm 8 is proportional to the effective length of the torsion bar 3. Therefore,
By moving the adjusting member 2 closer to the moment arm 8, the torsion bar has less angular displacement with respect to the same load, and the spring has high rigidity. On the other hand, by moving the adjusting member 2 away from the moment arm 8, the torsion bar is moved. The angular displacement of is increased, and the spring becomes a less rigid spring. Therefore, in this embodiment, since the spring constant of the torsion bar 3 is adjusted to adjust the support force, the structure is simplified. Further, even if there is a deviation from the design value, this can be easily corrected.

The present invention is not limited to the above embodiment,
Various changes are possible. For example, the cushioning property of the seat cushion can be adjusted by applying it to the cushion spring portion of the seat cushion. Further, the torsion bar and the adjusting member may have an elliptical cross section, a parallel cut section of a circle, or other cross sectional shapes as long as mutual rotation is restricted.

[Effects of the Invention] As described above, the present invention changes the spring constant based on the effective length of the torsion bar for the adjusting member in which the relative rotation with the torsion bar is constrained. The effect is that the force can be adjusted arbitrarily, and the appearance of the seat is not deformed (which occurs when the pad is pushed up).

[Brief description of drawings]

FIG. 1 is an exploded perspective view of the present invention applied to a lumbar support portion of a seat back, and FIG. 2 is a sectional view taken along line II-II thereof. 2 ... adjustment member, 3 ... torsion bar, 5 ... pinion, 6 ... rack, 7 ... load receiver, 9 ... back frame, 10 ... dial.

Claims (1)

[Scope of utility model registration request] 1. A torsion bar having both ends attached to a seat frame so that the torsion bar is rotatable, a load receiving member mounted to impart torsional rotation to the torsion bar, and the torsion bar. A seat device, comprising: an adjusting member that is inserted through a torsion bar in a state where rotation is restricted and moves in the longitudinal direction of the torsion bar; and an operating member that moves the adjusting member.