JP2002153351A - Lumbar support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce uncomfortable feeling of a seated occupant in an arrangement state. SOLUTION: In this lumbar support device, an elastic wire body 6 has an initial state wherein the wire body 6 is bent in a recessed state to a back part support face 5a such that energizing force is generated by movement of one end part, to apply minimum support force to the support face 5a, and has an arrangement state wherein the wire body 6 becomes nearly linear to the support face 5a by movement of the end part to apply maximum support force to the support face 5a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lumbar support device for providing an adjustable support force for supporting the waist of a person sitting on a seat to a back support surface of a seat back of the seat.

[0002]

2. Description of the Related Art Conventionally, a lumbar support device of this type is disclosed in Japanese Utility Model Laid-Open No. 60-140457.

[0003] The elastic wire body extends in the width direction of the seat back so as to cross the back support surface of the seat back, and both ends are supported by the frame member of the seat back. A lumbar support device having an adjustment mechanism for moving one end of the seat back relative to the frame member in the width direction of the seat back. And, by the movement of one end of the elastic wire body by the operation of the adjusting mechanism,
The elastic wire is bent in the thickness direction of the seat back so as to generate a biasing force, thereby providing a supporting force to the back support surface of the seat back.

[0004] In this conventional device, the elastic wire is substantially parallel to the back support surface of the seat back by the movement of one end, so that an initial state in which the minimum support force is applied to the back support surface. The back support surface is bent in a convex shape so as to generate an urging force due to the movement of one end, whereby the back support surface is in an adjustment state in which the maximum support force is applied.

[0005]

However, in the above-described conventional apparatus, when the elastic wire is adjusted, the elastic wire is bent in a convex shape with respect to the back support surface of the seat back so as to generate an urging force. In this state, the pressure distribution on the back support surface increases substantially at the center of the back of the seated person in the width direction of the seat back. As a result, there is a possibility that the holding force in the width direction of the seat back of the back support surface for the occupant may be impaired.

Accordingly, it is an object of the present invention to solve the above-mentioned problems of the conventional device.

[0007]

Means for Solving the Problems In order to solve the above technical problem, the technical means adopted in the present invention is to generate an urging force by moving one end of the elastic wire. The back support surface of the seat back is bent in a concave shape so that the minimum support force is applied to the back support surface, and the one end moves to be substantially straight with the back support surface. Thus, the back support surface is brought into the adjustment state in which the maximum support force is applied.

According to this technical means, the elastic wire body changes its shape between a concave state and a substantially straight state with respect to the back support surface of the seat back, whereby the back support surface is formed. The applied supporting force is adjusted. Therefore, the elastic wire cannot be convex with respect to the back support surface, and as a result, the pressure distribution on the back support surface as in the conventional device does not increase in the width direction of the seat back substantially at the center of the back of the seated person. Can be done.

[0009] More preferably, the elastic wire is independent of a spring structure supported by the frame member and supporting the back support surface.

[0010] More preferably, the elastic wire body has a pair of pressing portions extending in the width direction of the seat back, and a U-shaped supporting portion connecting the pressing portions and forming the other end of the elastic body. It is good to have a shape.

More preferably, a bracket fixed to the frame member and engaged with the supporting portion of the elastic wire is preferably provided.

[0012] More preferably, the adjusting mechanism comprises a sector gear supported by the frame member, and one end of the resilient linear body supported by the frame member and connected to the sector gear substantially orthogonal to the sector gear. A movable member to which a free end of the pressing portion constituting the portion is connected.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a seat back 1 of a vehicle seat includes a seat back frame 2 serving as a frame of the seat back 1, a spring structure 3 serving as an elastic support of the seat back 1, and a book. A lumbar support device 4 which is a main part of the present invention, wherein the back support surface 5a
Are formed on the spring structure 3 and covered with a skin (not shown).

The seat back frame 2 has an inverted U-shape in which a pair of side frames 21 and 22 having a channel shape are connected to each other by a pipe-shaped upper frame 23.

The spring structure 3 includes a pair of left and right linear members 31 and 3.
It is a sheet-like member in which a plurality of formed wires 33 are stretched between two. The spring structure 3 includes a pair of left and right linear members 31 and 32 extending in parallel with the side frames 21 and 22 and extending the formed wire 33 in the width direction of the seat back (the left and right direction in FIG. 1). , 22 and the wires 31, 32 are connected to the seat back frame 2.
And is supported by the seat back frame 2. The spring structure 3 is bent and deformed in the thickness direction of the seat back (up and down direction in FIG. 4) when a seated person sitting on the vehicle seat leans on the seat back 1, and thereby the back support surface 5 a of the pad 5 is formed. To elastically support the back of the seated person.

As shown in FIG. 2, the lumbar support device 4 includes a torsion spring 6 and an adjusting mechanism 7.

The torsion spring 6 is formed by bending a wire into a U-shape, and includes a pair of upper and lower pressing portions 61 and a pair of upper and lower pressing portions 61 extending in the width direction of the seat back and substantially parallel to each other. A supporting portion 62 to be connected is integrally provided. The free ends of the pair of upper and lower pressing portions 61 (ends opposite to the ends connected by the support portions 62) are bent inward such that their end faces face each other at a predetermined interval, and Are formed. Further, a rectangular lumbar plate 8 long in the width direction of the seat back is fixed to the pressing portion 61. The plate body 81 of the lumbar plate 8 includes
The pair of cut-and-raised portions 82 projecting from the back side is
The lumbar plate 8 is fixed to the torsion spring 6 by inserting a pair of upper and lower pressing portions 61 between the cut-and-raised portion 82 and the plate body 81. .

The adjusting mechanism 7 includes a mounting bracket 71, a motor 73 having a reduction gear mechanism having a pinion gear 72 fixed to an output shaft 73a, a sector gear 74 meshing with the pinion gear 72, and a movable link 75 connected to the sector gear 74.
It is composed of

As shown in FIGS. 2 and 3, the mounting bracket 71 is formed with a pair of upper and lower flange portions 71a projecting toward the front surface and a bulging portion 71b projecting toward the rear surface and opening at the rear surface. Have been. The motor 73 accommodates the pinion gear 72 in the bulging portion 71b and is screwed to the surface of the mounting bracket 71. Sector gear 7
4 is rotatably supported on the rear surface side of the mounting bracket 71 by a pin 76, and its tooth portion is inserted into the opening of the bulging portion 71b and meshes with the pinion gear 72. The movable link 75 has a U-shape, is disposed on the front side of the mounting bracket 71, and has a pair of flange portions 71a.
It is rotatably supported by a pin 77 orthogonal to the pin 76 between the upper and lower arm portions 75a. The upper and lower arm portions 75a of the movable link 75 are formed with fitting holes 75d into which the support ends 63 of the torsion springs 6 are fitted.

A brim portion 75b is formed integrally with the upper arm portion 75a of the movable link 74. The flange portion 75b projects through the opening 71c formed when the flange portion 71a is formed in the mounting bracket 71, and protrudes toward the rear surface of the mounting bracket 71. The sector gear 74 is formed in the connecting hole 75c formed in the flange portion 75b. The connecting protrusion 74a formed integrally with the second member is inserted therethrough. Thereby, the sector gear 74 and the movable link 75 are connected, and the movable link 7
The rotation of the sector gear 75 causes the sector gear 75 to rotate.

In such a configuration, the distance between the end surfaces of the pair of upper and lower supporting ends 63 of the torsion spring 6 is
The distance between the pair of upper and lower arm portions 75a of the movable link 74 is smaller than the distance between the upper and lower arm portions 75a. The pair of upper and lower support ends 63 are vertically bent so as to increase the distance between the upper and lower arms 75a.
By being fitted into the fitting hole 75d, the movable link 75 is connected. Then, the mounting bracket 71 is fixed to the side frame 21 of the seat back frame 2, whereby one end of the torsion spring 6 is supported by the seat back frame 2.

The other end of the torsion spring 6 engages the support portion 62 with the support bracket 9, and the support bracket 9 is connected to the side frame 22 of the seat back frame 2.
, Is supported by the seat back frame 2. As shown in FIG. 5, the support bracket 9 has an L-shape in which a support portion 91 and an engagement portion 92 are integrally provided. A pair of fitting arms 91a are integrally formed on the back side of the support portion 91 to protrude.
a into the fitting hole 22 a formed in the side frame 22, the support bracket 9 is attached to the side frame 2.
It is fixed to 2. An engaging claw 9 is provided at the tip of the fitting arm 91a.
1b is formed, and this engaging claw 91b is
The support bracket 9 is prevented from falling off from the side frame 2 by being engaged with the engagement hole 22b near “a”. An engagement groove 92a is formed in the engagement portion 92, and the support portion 62 of the torsion spring 6 is engaged in the engagement groove 92a. In addition, the support bracket 9
The support portion 91 and the engagement portion 92 may be formed of different members.

As shown in FIG. 4, the movable link 75
Can take an initial position (solid line in FIG. 4) and an adjustment position (two-dot chain line in FIG. 4) by rotation of the sector gear 74. When the movable link 75 is at the initial position, the fitting hole 75d (the torsion spring) of the movable link 75 into which the supporting end 63 of the torsion spring 6 fits in the sheet width direction than when the movable link 75 is at the adjustment position. The support point on one end of the torsion spring 6 approaches the engaging groove 92b of the support bracket 9 (the support point on the other end of the torsion spring 6) with which the support portion 62 of the torsion spring 6 engages. When the movable link 75 is at the adjustment position, the pressing portion 61a of the torsion spring 6 is in the adjustment state A in which the shape becomes a straight line substantially parallel to the back support surface 5a (two-dot chain line shown in FIG. 4). When the movable link 75 is at the initial position, the fitting hole 75d of the movable link 75 approaches the engagement groove 92b of the support bracket 9, so that a biasing force is generated on the back support surface 5a. This is the initial state B of the shape bent concavely in the sheet thickness direction (solid line shown in FIG. 4).

As shown in FIG. 5, the support bracket 9
The inclined guide surface 92b is formed in the engaging portion 92 from the engaging groove 92a. Torsion spring 6
Before the support portion 62 is engaged with the engagement groove 92a, as shown in FIG. 5, the support portion 62 is in contact with the inclined guide surface 92b (dotted line in FIG. 5). Therefore, when assembling the torsion spring 6, first, the support end 63 is fitted into the fitting hole 75d of the movable link 75 at the initial position to connect the torsion spring 6 with the movable link at the initial position. In this state, the torsion spring 6
When the torsion spring 6 is pulled so as to bend the pressing portion 61 in the direction of the arrow shown in FIG. 5, the support portion 62 moves while being guided by the inclined guide surface 92b, and eventually engages with the engagement groove 92b. Thereby, the torsion spring 6 is easily assembled in the initial state B (solid line in FIG. 5).

The engagement groove 92a is provided in the torsion spring 6
In the initial state B, the back support surface of the pad 5 such as the urging force generated at the support end 63 due to the bending of the torsion spring 6, the load generated when the occupant leans on the seat back 1, and the tension load on the skin. It has a surface receiving the load from 5a and opens in the direction opposite to these forces. Therefore, in the initial state B of the torsion spring 6, the support end 63 of the torsion spring 6 does not come off from the engagement groove 92b of the support bracket 9. Further, in the adjustment state A of the torsion spring 6, the load on the support end 63
From the engagement groove 92b.

Next, the operation of the lumbar support device 4 will be described with reference to FIG.
Will be described.

When the torsion spring 6 is in the initial state A, the pressing portion 6 of the torsion spring 6
1 is concave with respect to the back support surface 5a, the torsion spring 6 does not apply a support force to the back support surface 5a (provides a minimum support force), and the back support surface 5a
Means that the back of the seated person is elastically supported by the spring structure 3. In this state, when the motor 73 is driven to rotate the pinion gear 72 to rotate the sector gear 74, the movable link 75 connected to the sector gear 74 is rotated from the initial position to the adjustment position, and the supporting end of the torsion spring 6 is rotated. The portion 63 moves away from the support portion 62 in the seat back width direction (the left-right direction in FIG. 4), and the pressing portion 61 of the torsion spring 6 becomes straight (the torsion spring 6 is in the adjusted state). As a result, the torsion spring 6 gives the maximum support force to the back support surface 5a, and the back support surface 5a elastically supports the back of the seated person with the spring structure 3 and the torsion spring 6. It will be. When the movable link 75 is adjusted to an arbitrary position between the initial position and the adjustment position by driving the motor 73, the torsion spring 6 moves the back support surface 5.
The supporting force applied to a is adjusted to an arbitrary supporting force desired by the seated person.

In the above-described embodiment, the output shaft 73a of the motor 73 is connected to the pin 7 supporting the movable link 75.
7, the rotation of the pinion gear 72 is transmitted to the movable link 75 via the sector gear 74.
By arranging the output shaft 73a of the motor 73 in a direction substantially parallel to the pin 77, for example, substantially parallel to the pin 77, the sector gear 74 is abolished, the pinion gear 72 meshes with the movable link 75, and the rotation of the pinion gear 72 is reduced. Direct movable link 7
5 may be transmitted.

[0029]

According to the present invention, the elastic wire is bent concavely with respect to the back support surface so as to generate a biasing force by the movement of one end, and the minimum support force is exerted on the back support surface. Since the arrangement is such that the applied state is substantially straight with respect to the back support surface by the movement of one end and the adjustment state in which the maximum support force is applied to the back support surface, the elastic wire is By preventing the back support surface from being convex, the pressure distribution on the back support surface can be prevented from increasing around the back of the occupant in the width direction of the seat back.
As a result, it is possible to reliably secure the feeling of holding the back support surface in the sheet width direction. In addition, in the adjustment state, the elastic wire does not become convex with respect to the back support surface, so that the lumbar support device surely gives the occupant a feeling of support (effectiveness) without giving the occupant a feeling of convexity. Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view of a seat buck on which a lumbar support device according to the present invention is mounted.

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

FIG. 3 is a sectional view showing an adjustment mechanism of the lumbar support device according to the present invention.

FIG. 4 is a schematic view showing the operation of the lumbar support device according to the present invention.

FIG. 5 is a front view showing the assembly of the elastic wire of the lumbar support device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seat back 2 Seat back frame (frame member) 3 Spring structure 5a Back support surface 6 Torsion spring (elastic wire) 7 Adjusting mechanism 9 Support bracket (bracket) A Adjusted state B Initial state 61 Pressed part 74 Sector gear 75 Movable link (Movable member)

Claims (5)

[Claims] An elastic wire extending in a width direction of the seat back so as to cross a back support surface of the seat back, and both ends of which are supported by a frame member of the seat back; and the frame member of the elastic wire. An adjustment mechanism for moving one end supported by the frame member in the width direction of the seat back with respect to the frame member, wherein the one end of the elastic wire body is moved by the operation of the adjustment mechanism. In a lumbar support device that applies a supporting force to a back support surface of the seat back by bending an elastic linear body in a thickness direction of the seat back so as to generate an urging force, the elastic linear body includes the one of the elastic linear bodies. The initial state in which the back support surface is concavely bent so as to generate an urging force by the movement of the end portion and the minimum support force is applied to the back support surface, and the movement of the one end portion The lumbar support device is substantially straight with respect to the back support surface, and is in an adjustment state in which a maximum support force is applied to the back support surface. 2. The lumbar support device according to claim 1, wherein the elastic wire is independent of a spring structure supported by the frame member and supporting the back support surface. 3. The elastic linear body has a U-shape having a pair of pressing portions extending in a width direction of the seat back and a supporting portion connecting the pressing portions and forming the other end of the elastic body. The lumbar support device according to claim 1, which is provided. 4. The lumbar support device according to claim 3, further comprising a bracket fixed to the frame member and engaged with the support portion of the elastic wire. 5. An adjusting mechanism comprising: a sector gear supported by the frame member; and a sector gear supported by the frame member substantially perpendicular to the sector gear and connected to the sector gear. 4. A movable member to which a free end of the pressing portion is connected.
The lumbar support device as described.