JPH0670647U - Lumber support mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] Regarding a lumbar support that supports the lumbar spine of a seated person in a vehicle seat, etc., the amount of deflection when seated is small, the support feeling is good, and the extrusion amount and the extrusion force can be changed The purpose is to provide a lumbar support that is easy and has a large degree of freedom in design. [Structure] A crankshaft-shaped torsion bar 14 whose both ends are rotatably supported on both sides of a seatback frame, a support plate 15 provided on a crankpin portion 14c of the torsion bar, and the torsion bar. Drive unit 16 for driving one of the crank arm portions 14b in the direction of the back of the seated person / in the direction away from the back
It consists of and.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lumbar support for supporting a lumbar vertebra of a seated person in a vehicle seat or the like.

[0002]

[Prior art]

 Next, a conventional example will be described with reference to the drawings. FIG. 4 is a top view of a conventional lumbar support, and FIG. 5 is an enlarged perspective view of a nut portion in FIG.

In FIG. 4, a side frame 2 a of a seat back frame 2 is provided inside the seat back 1. Reference numeral 3 is a shaft provided along the side frame 2a.

Numerals 4 and 5 are torsion bars having winding portions 4 a and 5 a wound around the shaft 3 at the base end portion. One rotation end of each of the torsion bars 4 and 5 extends to the center of the seat back 1, and a support plate 6 for pressing the lumbar vertebra of the seated person is attached to the tip of each of the rotation ends.

Reference numeral 7 is a threaded rod arranged so as to intersect the torsion bars 4, 5 on a plane parallel to the rotation plane of the torsion bars 4, 5. Reference numeral 8 is a motor for rotationally driving the screw rod 7, and 9 is a nut member that is screwed onto the screw rod 7 and has the other rotating ends of the torsion bars 4 and 5 engaged with the upper and lower surfaces thereof.

Next, the operation of the above configuration will be described. When the motor 8 is driven, the screw rod 7 rotates, and the nut member 9 whose rotation is restricted by the engagement of the torsion bars 4 and 5 moves along the screw rod 7. When the nut member 9 moves, the torsion bars 4 and 5 rotate about the shaft 3, and the support plate 6 moves the lumbar vertebra of the seated person in a pressing direction / a direction away from the lumbar vertebra of the seated person.

[0007]

[Problems to be solved by the device]

 However, in the lumbar support having the above structure, the support plate 6 has a structure which is attached to the free ends of the torsion bars 4 and 5 which rotate about the shaft 3.

Therefore, there is a problem that the torsion bar is largely deflected by the pressing force of the back of the seated person in the seated state, and the support feeling is insufficient. The present invention has been made in view of the above problems, and an object thereof is to provide a lumbar support mechanism having a small amount of deflection when seated and a good support feeling.

Another object of the present invention is to provide a lumbar support in which the extrusion amount and the extrusion force can be easily changed and the flexibility of design is large.

[0010]

[Means for Solving the Problems]

 The invention according to claim 1 for solving the above-mentioned problems is provided with a crankshaft-shaped torsion bar whose both ends are rotatably supported on both sides of the seatback frame, and a crankpin portion of the torsion bar. It comprises a support plate and a drive unit for driving one of the crank arms of the torsion bar in the direction toward and away from the back of the seated person.

According to a second aspect of the invention, in the torsion bar according to the first aspect of the invention, the base end portion of the torsion bar is loosely fitted to one side of the seat back frame. A first crank arm portion bent substantially at a right angle from the front end portion of the rotation support portion, a substantially right angle bent from a front end portion of the first crank arm portion, and separated from one side portion of the seat back frame. The crank pin portion extending in the direction of the arrow, the second crank arm portion bent substantially at a right angle from the tip portion of the crank pin portion, and the tip bent at a substantially right angle from the tip portion of the second crank arm portion. The part is composed of a second rotation support part which is loosely fitted to the other side part of the seat back frame.

According to a third aspect of the present invention, in the drive unit according to the first or second aspect of the invention, a base end portion is rotatably attached to the seat back frame side, and the torsion end is attached to the rotation end portion. A link having a first elongated hole extending in the radial direction and a second elongated hole extending in the same direction as the first elongated hole, through which the first crank arm portion of the bar is inserted; A screw rod arranged so as to intersect with the link, a nut member provided with a protrusion that is screwed into the screw rod and engages with the second long hole of the link, and the screw rod is rotationally driven. It consists of a motor.

[0013]

[Action]

 In the lumbar support mechanism according to the first and second aspects of the invention, both ends of the torsion bar are loosely fitted to both side portions of the seat back frame, and the support plate is attached to the substantially central portion. This corresponds to a model in which a load is applied to the approximately central part of the beam supported at both ends. On the other hand, the conventional lumbar support mechanism corresponds to a model in which a load is applied to the front end of a single-end support beam. Therefore, if the materials and diameters of the torsion bars are the same and the same load acts, the amount of deflection of the present invention is smaller than that of the conventional example, and the support feeling is good.

In the lumbar support mechanism according to the third aspect of the invention, the drive of the torsion bar is performed via the link that is locked to the first crank arm portion of the torsion bar. Therefore, by freely selecting the shape of this link, it is possible to freely select the extrusion amount and the extrusion force of the support plate. Also, by freely selecting the shape of the link, the degree of freedom in the mounting position of the motor is increased.

[0015]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a fragmentary perspective view of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a sectional view taken along line AA in FIG.

First, the configuration of the present embodiment will be described with reference to FIG. In the figure, 11 and 12 are side portions of the seat back frame. A bracket 13 is fixed to the side portion 11 of one of the seat back frames. A hole 13a is formed on a plane parallel to the seat back frame 11 of the bracket 13, and an elongated hole 13b is formed on a plane perpendicular to the seat back frame 11.

On the other hand, a hole 12 a at the same level as the hole 13 a of the bracket 13 is formed in the side portion 12 of the other seat back frame. Reference numeral 14 denotes a crankshaft-shaped torsion bar, one end of which is loosely fitted in the hole 13a of the bracket 13 and the other end of which is loosely fitted in the hole 12a of the seatback frame 12. The torsion bar 14 has a base end portion which is loosely fitted in a hole 13a of the bracket 13 of the one side portion 11 of the seatback frame and a tip end portion of the first rotation support portion 14a. The first crank arm portion 14b bent downward at a right angle and the first crank arm portion 14b are bent horizontally at a substantially right angle from the tip end portion of the first crank arm portion 14b, and separated from one side portion 11 of the seatback frame. Direction, a second crank arm portion 14d bent upward at a substantially right angle from the tip end portion of the crank pin portion, and a substantially right angle bent from the tip end portion of the second crank arm portion 14d. The bent and front end portion is composed of a second rotation support portion 14e which is loosely fitted in the hole 12a of the other side portion 12 of the seat back frame. A support plate 15 is attached to the crank pin portion 14c of the torsion bar 14.

Reference numeral 16 denotes a drive unit that drives the first crank arm portion 14b of the torsion bar 14 in the direction toward the back of the seated person / in the direction away from the back. Next, the drive unit 16 will be described. Reference numeral 17 is a link whose base end is rotatably attached to the bracket 13 using a pin 18. A first elongated hole 17a extending in the radial direction and a second elongated hole 17b also extending in the radial direction are formed at the rotating end of the link 17.

Reference numeral 19 is a screw rod that is rotationally driven by a motor 20 provided on the bracket 13 and that is arranged so as to intersect with the link 17. A nut member 21 is screwed onto the screw rod 19. On the upper surface of the nut member 21, a first protrusion 21a that engages with the second elongated hole 17b of the link 17 is formed. Further, the bracket 13 is formed with a guide hole 13c extending in the same direction as the screw rod 19, and the lower surface of the nut member 21 is formed with a second protrusion 21b engaging with the guide hole 13c. It

Next, the operation of the above configuration will be described. When the motor 20 is driven, the screw rod 19 rotates. In the nut member 21, the first protrusion 21a is engaged with the second elongated hole 17b of the link 17 and the second protrusion 21b is engaged with the guide hole 13c of the bracket 13, respectively. It moves along the screw rod 19 with the rotation of. When the nut member 21 moves, the link 17 rotates about the pin 18 and pushes the first crank arm portion 14b of the torsion bar 14 in the direction toward and away from the back of the seated person. Therefore, the torsion bar 14 swings in the direction of the arrow in FIG. 1 around the hole 13a of the bracket 13 on the one side portion 11 of the seat back frame and the hole 12a on the other side portion 12 of the seat back frame to support it. The plate 15 supports the lumbar spine of the seated person.

According to the above configuration, the first and second rotation support portions 14a and 14e, which are the opposite ends of the torsion bar 14, play in the holes 13a and 12a provided on both side portions 11 and 12 of the seat back frame. The structure is such that the support plate 15 is fitted and the support plate 15 is attached to the substantially central portion. This corresponds to a model in which a load acts on the substantially central portion of the support beams at both ends.

On the other hand, the conventional lumbar support mechanism corresponds to a model in which a load acts on the tip of the one-end support beam. Therefore, if the material, diameter, etc. of the torsion bar are the same and the same load is applied, the deflection amount of the present invention is smaller than that of the conventional example, and the support feeling is good.

Further, the torsion bar 14 is driven via a link 17 which is locked to the first crank arm portion 14b. Therefore, by arbitrarily selecting the shape of the link 17, the pushing amount and pushing force of the support plate 15 can be freely selected. Further, by freely selecting the shape of the link 17, the degree of freedom of the mounting position of the motor 20 is increased.

[0024]

[Effect of device]

 As described above, according to the present invention, the structure in which the torsion bar is supported at both ends makes it possible to realize a lumbar support mechanism with a small amount of deflection when seated and a good support feeling.

Further, since the torsion spring is driven via the link, it is possible to realize a lambertian support in which the pushing amount and pushing force can be easily changed and the degree of freedom in design is great.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a side view of the configuration in FIG.

FIG. 3 is a sectional view taken along the line AA in FIG.

FIG. 4 is a top view of a conventional lumbar support.

5 is an enlarged perspective view of a nut portion in FIG.

[Explanation of symbols]

 11,12 Seat back frame 14 Torsion bar 14b Crank arm part 14c Crank pin part 15 Support plate 16 Drive part 17 Link

Claims (3)

[Scope of utility model registration request] 1. A crankshaft-shaped torsion bar (14) whose both ends are rotatably supported on both sides of a seatback frame, and a support plate provided on a crankpin part (14c) of the torsion bar. (15) and one crank arm portion (14b) of the torsion bar
A lumbar support mechanism comprising: a drive section (16) for driving the seat back toward and away from the seated person. 2. The first rotation support part (14a), the base end part of which is loosely fitted to one side part (11) side of the seat back frame, the first rotation support part. A first crank arm portion (14b) bent substantially at a right angle from a tip portion of (14a), the first crank arm portion (1
4b) is bent at a substantially right angle from the tip of the seat back frame and extends in a direction away from the one side (11) of the seat back frame, the tip of the crank pin (14c) The second crank arm portion (14d) bent at a substantially right angle and the tip portion of the second crank arm portion (14d) are bent at a substantially right angle, and the tip portion is the other side portion of the seat back frame. (12)
The lumbar support mechanism according to claim 1, comprising a second rotation support portion (14e) loosely fitted to the side. 3. The drive portion (16) has a base end portion rotatably attached to the seat back frame side, and the torsion bar (14) at the rotation end portion.
The first crank arm portion (14b) of the first through-hole (17a) and the first long hole (1) extending in the radial direction.
7a), a link (17) having a second elongated hole (17b) extending in the same direction, a screw rod (19) arranged so as to intersect with the link (17), The second part of the link (17) is screwed into the screw rod (19).
A nut member (21) provided with a protrusion (21a) for engaging with the elongated hole (17b) of the above, and a motor (20) for rotationally driving the screw rod (19). The lumbar support described in 1 or 2.