JP2002345597A - Seat for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat for vehicles which allows riding persons to feel supported softly on their lumber vertebrae while securing the support for the their vertebrae. SOLUTION: The seat is constituted of a seat back frame 4 having a hollow part 4a, a roughly flat lumber support plate 29 which covers the hollow part 4a of the seat back frame 4 while the lower end part 29a thereof is rotatably pivoted on the seat back frame 4 by a support means 30, a lumber support mechanism 21 capable of freely controlling a roughly intermediate portion of the lumber support plate 29 to move longitudinally and an elastic member 12 which is so arranged as to hold the rear side of the upper end part 29b of the lumber support plate 29 while being spread between it and the seat back frame 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat, and more particularly to a vehicle seat having a lumbar support mechanism for holding a passenger's lumbar spine.

[0002]

2. Description of the Related Art As a conventional vehicle seat provided with a lumbar support mechanism for holding a passenger's lumbar spine, for example, as disclosed in Japanese Patent Application Laid-Open No. H10-146240, the inside of left and right side frames of a seat back frame is known. In each case, the upper and lower ends of a shaft frame whose axis is curved in a substantially arcuate shape toward the front are fixed with screws, and there is a structure in which a cloth spring is stretched between the shaft frames. Also,
As shown in Japanese Utility Model Laid-Open Publication No. 4-31545, the upper end of the lumbar support plate is engaged with a wire extending between the upper portions of the side frames of the seat back frame, and the lower end of the lumbar support plate is connected to the seat cushion. Some are provided on the front side of the supported lumbar plate holding bar.

[0003]

However, in such a conventional technique, since it cannot move back and forth, the depth for supporting the lumbar vertebra cannot be controlled, and the cloth spring is bent between the shaft frames. The occupants lack support for the lumbar spine. Further, in the latter technique, the occupant's waist cannot be supported at the seatback position in the driving state, and the lumbar support held by the wire is unlikely to bend, and the lumbar spine of the occupant may be compressed.

The present invention has been made by paying attention to such a conventional technique, and provides a vehicle seat which ensures the occupant's lumbar support and gives the occupant a soft feeling of supporting the lumbar vertebra. To provide.

[0005]

According to a first aspect of the present invention, there is provided a seatback frame having a hollow portion, and a lower end portion rotatable by the supporting means on the seatback frame while covering the hollow portion of the seatback frame. A lumbar support plate having a substantially flat plate shape supported by the lumbar support plate, a lumbar support mechanism capable of controlling a substantially intermediate portion of the lumbar support plate to be able to move back and forth, and a back side of an upper end portion of the lumbar support plate. And an elastic member stretched between the seat back frames.

According to the first aspect of the present invention, by operating the lumbar support mechanism, the substantially middle portion of the lumbar support plate can be moved in the front-rear direction, so that the lumbar vertebra of the occupant can be reliably supported. Can be. Moreover, since the upper end of the lumbar support plate is held by an elastic member, it does not give a feeling of pressure to the lumbar spine,
This will give a soft feeling of support to the occupant's lumbar spine.

According to a second aspect of the present invention, there is provided the vehicle seat according to the first aspect, wherein the elastic member is for an active headrest which can be extended only by a secondary collision load caused by a collision of the vehicle. Consisting of a return spring,
The upper end of the lumbar support plate is constantly urged forward.

According to the second aspect of the present invention, since the elastic member constantly biases the upper end of the lumbar support plate to the front side, the movement of the lumbar support plate to the front side by the operating means requires a small operating force. No problem. In addition, since the secondary collision load due to the collision of the own vehicle is applied to the elastic member via the lumbar support plate, the tension can be reliably transmitted to the occupant regardless of the seating position.

According to a third aspect of the present invention, there is provided the vehicle seat according to the first or second aspect, wherein the supporting means includes a lower end portion of the lumbar support plate having a cross section U.
It is formed in the shape of a letter.

According to the third aspect of the present invention, the lumbar support plate can be moved by bending the U-shaped cross section of the lower end of the lumbar support plate in the opening and closing direction.

According to a fourth aspect of the present invention, there is provided the vehicle seat according to the first or second aspect, wherein the support means forms a lower end of the lumbar support plate in an inverted U-shaped cross section. Do it.

According to the fourth aspect of the invention, the lumbar support plate can be moved by bending the inverted U-shaped cross section of the lower end of the lumbar support plate in the opening and closing direction.

According to a fifth aspect of the present invention, there is provided the vehicle seat according to any one of the first to fourth aspects, wherein:
A headrest support member is installed between the upper end portions of the side frames of the seat back frame so as to be rotatable back and forth, and the headrest support member has a headrest holder for holding an active headrest and an upper end portion of the lumbar support plate. A pressure receiving member adjacent to the back side is disposed, and the pressure receiving member is disposed at a position where it can receive a secondary impact load by an occupant accompanying a rear-end collision.

According to the fifth aspect of the present invention, since the headrest supporting member supporting the headrest holder supporting the active headrest is provided between the side frames, when the secondary collision force of the occupant is generated,
The front and rear movement of the active headrest is appropriately performed, and the occupant's neck is more reliably protected. Further, since the pressure receiving member supported by the headrest support member passes through the lumbar support plate, even if the occupant is in the out position, the lumbar support plate is large. The transmission of the load can be assured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that FR is described as a front side, RR is a rear side, UP is an upper side, and LWR is a lower side.

FIGS. 1 to 13 show an embodiment of the present invention. Reference numeral 1 denotes an automobile seat as a "vehicle", which comprises a seat back 2 and a well-known seat cushion (not shown). . Reference numeral 3 denotes an active headrest supported by the seat back 2.

The seat back 2 comprises a seat back frame 4, trims and pads (not shown) for covering the frame 4, a headrest support member 7, a pressure receiving member 8, a headrest holder 9, and a lumbar support mechanism 21. Be done.

The seat back frame 4 is provided in a substantially horizontal manner between side frames 5 and 5 made of symmetrical iron plates disposed on both sides and front FRs of upper ends 5a and 5a of the side frames 5. An upper cross member 10 made of an iron plate having a U-shaped cross section and a lower cross member 11 made of an iron plate which is installed substantially horizontally at lower ends 5b and 5b of the side frames 5, and has a hollow portion. 4a is formed. The side frame 5, the upper cross member 10, and the lower cross member 11 are mutually supported by welding GW.

A return spring for an active headrest which is an "elastic member" between the side frames 5 and 5 is an "elastic member" which does not bend during normal use and can be extended only by a secondary collision load due to a collision of the own vehicle. 12 and an S-shaped spring 35 for improving the ride comfort of the occupant by flexing with a load during normal use, and the return spring 12 for the active headrest is provided with an upper end 29b of a lumbar support plate 29 described later. Is held so as to urge the rear surface side toward the front side FR and is directly mounted on the side frames 5 and 5 of the seat back frame 4, and the S-shaped spring 35 is mounted on the side frame 5 via the clips 17 and 17. It becomes.

The pressure receiving member 8 has a straight portion 14 fixedly suspended by welding GW on a front surface FR at a central portion in the left-right direction of a rear surface portion 7b of the headrest support member 7 described later, Slightly forward FR from the lower end of straight section 14
And a curved portion 14a that hangs down from a bent position. A rear portion RR of a boundary between the straight portion 14 and the curved portion 14a has a bent portion 20 which is bent in the shape of a "ku" on the front side in a side view shown in FIG. The pressure receiving member 8 is located at a position where the occupant leaning on the seat back 2 can receive a secondary impact load due to a rear-end collision.

At the lower end 8a of the pressure receiving member 8, a cap 15 made of a synthetic resin is disposed so as to cover the lower end 8a of the pressure receiving member 8. On the surface of the rear side RR of the cap 15, The lower end 8a of the pressure receiving member 8 is engaged with the return spring 12 for the active headrest.
Is always urged toward the front side FR by the return spring 12 for the active headrest. That is, the rear surface portion 7b of the headrest support member 7 is constantly urged in a direction in which it comes into contact with a stopper surface 10a of the upper cross member 10 described later. Since the surface of the rear side RR of the cap 15 is formed as a smooth surface with little frictional resistance, the return spring 12 for the active headrest can slide up and down on the smooth surface.

The return spring 12 for the active headrest is formed in a wire shape, and may have a cross section of a substantially perfect circle or a substantially regular polygon, as long as it can rotate itself. In addition, the coil spring 12a has a "spring force" that does not extend under a sitting load of an occupant (not shown) but can extend only under a secondary impact load accompanying a rear-end collision.
Are formed at two places on the return spring 12 for the active headrest.

As shown in FIG. 3, the headrest support member 7 is made of an iron plate, extends right and left, and has an upper surface portion 7a and a rear surface portion 7b bent at right angles to form an inverted L-shaped cross section. It is formed in. As shown in FIG. 4, the headrest support member 7 is formed with support portions 7c, 7c whose left and right ends are bent from the rear surface portions 7b, 7b to the front FR. The upper ends 5a, 5a of the side frames 5, 5 of the seat back frame 4 are rotatably pivoted forward and backward FR, RR by stepped bolts 5c and bushes 6 for absorbing rubbing noise and shock during rotation. Be supported.

The upper part 7a itself and the rear part 7
As shown in FIGS. 4 to 6, first and second through holes 19 and 19a through which the headrest holder 9 is inserted and supported are formed in the bracket 7d which is bent and protruded to the front side FR from the side b.
Are formed coaxially in the vertical direction and separated from each other. In other words, the head 9a of the headrest holder 9 is supported by the upper first through hole 19, and the engaging portion 9b of the headrest holder 9 is supported by the lower first through hole 19a. Become.

As shown in FIGS. 1 to 4, the upper cross member 10 is made of an iron plate, and is integrally formed with an upper surface portion 10b extending left and right and the stopper surface 10a. The upper surface portion 10b has a U-shaped cross section in which the front side FR is closed and the rear side RR is opened. The stopper surface 10a is formed in a wall shape from below the upper surface portion 10b. The stopper surface 10a and the upper surface portion 10
b, the straight portion 14 of the pressure receiving member 8
A long hole 10c is formed before and after the can be inserted and moved. A cutout 10 is formed in the upper surface 10b to prevent interference with the stay 13 of the active headrest 3.
d and 10d are formed.

The rear surface 7b of the headrest support member 7
As shown in FIG. 3, the lower end 7e of the cushion member 16 is suspended from the upper cross member 10 to a position opposite to the stopper surface 10a which is suspended from the upper cross member 10. The lower end portion 7e of the rear surface portion 7b of the headrest support member 7 collides with the buffer portion 16a, and further movement is stopped. That is, the rotation preventing position of the headrest support member 7 itself to the rear side RR is specified.

The rear surface portion 7b of the headrest support member 7
The linear portion 14 of the pressure receiving member 8 is supported by welding, and when the pressure receiving member 8 approaches the stopper surface 10a of the upper cross member 10 as the headrest support member 7 rotates, the stopper surface The pressure receiving member 8 is provided in the second buffer portion 16b of the buffer member 16 disposed on the
The rear surface of the collides as shown in FIG. 7 and further movement is stopped. That is, the rotation preventing position of the headrest support member 7 itself to the front side FR is specified. The second buffer 16b is also a support for the buffer 16 on the stopper surface 10a.

As described above, the headrest holder 9 is supported by being engaged with the first and second through holes 19 and 19a formed in the headrest support member 7, and the stay of the active headrest 3 is provided. 13 is a member made of a synthetic resin. The headrest holder 9 has a well-known stopper mechanism that can move the stay 13 up and down as appropriate and can stop at an appropriate position.

As shown in FIG. 1, the straight portion 14 of the pressure receiving member 8 has a vertical shape when viewed from the front, and the holding position of the straight portion 14 is arranged on the rear side RR of the upper cross member 10. Therefore, even if the load of the occupant from the front side FR of the seat back frame 4, that is, the occupant is pressed against the seat back 2 from the front side FR, the shoulder point of the occupant becomes a straight line due to the collision of the own vehicle. Part 14
Will not interfere.

The lumbar support mechanism 21 includes an operating means 22 and a pin 23 so that a substantially intermediate portion of a lumbar support plate 29 described later can be controlled to be able to move back and forth.
, A support arm 25, a rod 26, a lumbar pressing member 27, and a winding spring 28.

The pin 23 is securely caulked to a bracket 37 which is welded and supported inside one of the side frames 5 (the left side in FIG. 1).
7, the support arm 25 is held, and a winding spring 28 is further wound thereon. The support arm 25 is rotatably supported by the pin 23.

The rod 26 is a round bar made of iron. One 26a is held by the support arm 25 by welding GW, and the other 26b is the other of the side frame 5 (FIG. 1).
On the right). The rod 26
The other 26b is bent halfway so as to be at the same position as the pin 23.

The lumbar pressing member 27 is made of a polypropylene resin square having a thickness of 2 mm,
6 and supported.

Reference numeral 29 denotes a lumbar support plate. The lumbar support plate 29 covers the hollow portion 4a of the seat back frame 4 and has a lower end 29a attached to the lower cross member 11 of the seat back frame 4 by a support means 30. It is rotatably supported. As shown in FIGS. 9 to 11, the lumbar support plate 29 has a vertical cross section with a front-side FR projecting, and FIG.
As shown in FIG. 2, although the cross section is concave on the front side FR, it is substantially in the shape of a flat plate. As shown in FIG. 8, it has a rectangular shape with a width of 240 mm and a length of 330 mm when viewed from the front, and has a thickness of 2 mm made of polypropylene. On the back surface of the lumbar support plate 29, that is, the surface on the rear side RR, a plurality of grid-like ribs 29c are formed as shown by broken lines in FIG. The rib 29c has the rod 26
Is formed with a fixing portion 31 which can be engaged with the fixing member. As shown in FIG. 13, the fixing portion 31 has an opening narrower than the rod 26, and is formed so as to be elastically fit and supported. Reference numeral 38 denotes an escape recess for preventing interference with the rod 26, and reference numeral 39 denotes a fitting portion to the rod 26 similar to the fixing portion 31.

As shown in FIGS. 9 to 11, the support means 30 is formed by integrally forming a lower end portion 29a of the lumbar support plate 29 in a U-shaped cross section. Code 32
Is the supporting means 30, that is, the lumbar support plate 2
9 through a through hole formed in the front side FR of the lower end portion 29a of the lower end portion 29a of the lower end portion 29a. It is held by the lower cross member 11.

Next, the operation according to this embodiment will be described.

By operating the operating means 22 of the lumbar support mechanism 21, the substantially middle portion of the lumbar support plate 29 can be moved in the front-rear direction, so that the lumbar spine of the occupant can be reliably supported. Moreover, the upper end 29b of the lumbar support plate 29
Is the return spring 12 for the active headrest
As a result, the lumbar vertebra of the occupant is not pressed and the lumbar vertebra of the occupant is softly supported.

Since the active headrest return spring 12 constantly urges the upper end 29b of the lumbar support plate 29 toward the front FR, the movement of the lumbar support plate 29 to the front FR by the operating means 22 is a light operation force. No. Further, the secondary collision load caused by the collision of the own vehicle is applied to the return spring 12 for the active headrest via the lumbar support plate 29.
, The transmission can be reliably performed regardless of where the occupant is seated.

Since the lower end portion 29a of the lumbar support plate 29 is formed in a U-shaped cross section, the U-shaped cross section of the lower end portion 29a of the lumbar support plate 29 bends in the opening / closing direction. 29 can move.

The seat back 2 is always in the state shown in FIGS. That is, the lower end 8 of the pressure receiving member 8 is formed by the return spring 12 for the active headrest.
Since the cap 15a is pressed against the front side FR, the rear surface portion 7b of the headrest support member 7 supporting the pressure receiving member 8 is in contact with the stopper surface 10a of the upper cross member 10 via the buffer member 16, and The active headrest 3 is held via a headrest holder 9 supported by the headrest support member 7.

In a driving state in which an occupant sits on a seat cushion of an automobile seat 1 including the seat back 2 and a seat cushion (not shown) and leans on the back of the seat back 2, the head of the occupant and the active headrest 3, there is a gap between the back of the occupant and the pressure receiving member 8. However, since a pad and a skin member (not shown) are interposed between the back of the occupant and the pressure receiving member 8, they are in close contact with each other. Further, when the occupant leans against the seat back 2 in a relaxed state when seated, the pad and the S-shaped spring 35 bend due to the load applied from the occupant's back, so that the occupant's back can be softly received. In state. Therefore, the seating feeling is good. Of course, no load is applied to the pressure receiving member 8. The lumbar support mechanism 21 protrudes toward the lumbar spine of the occupant and holds the lumbar spine.

In this state, when the own vehicle is collided, first, an impact load is applied to the front FR applied to the vehicle body, and the occupant receives a load in a direction of being thrown from the seat back 2 to the front FR. Next, a load moved to the rear side RR, that is, a secondary impact load (referred to as a secondary collision) is applied to the occupant. The impact value associated with the “secondary collision” is transmitted to the coil spring 12 a of the active headrest return spring 12 via the lumbar support plate 29.
Is greater than the load at which elongation begins, the coil spring 12 of the return spring 12 for the active headrest
As a is extended, the cap 15 at the lower end of the pressure receiving member 8 is moved to the rear side RR.

By moving the lower end of the pressure receiving member 8 to the rear side RR, the supporting portions 7c, 7c of the headrest supporting member 7 are moved.
FIG. 7C shows the stepped bolt 5c and the bush 6 centered on FIG.
As shown in FIG. The headrest holder 9 supported by the headrest support member 7 rotates to the front FR together with the headrest support member 7, and the stay 13 supported by the headrest holder 9 is controlled to rotate to the front FR together with the active headrest 3. In other words, by moving to the rear side RR of the occupant's head, the occupant's neck can be protected by reliably holding the occupant's head. Such rotation control is of course performed instantaneously.

Thus, the back of the occupant is
By moving to the rear side RR, the head of the occupant who should behave left is moved to the front side FR of the active headrest 3.
By moving to, it is surely held. Since the headrest supporting member 7 supporting the headrest holder 9 supporting the active headrest 3 is provided between the side frames 5 and 5, when the secondary collision force of the occupant occurs, the front and rear movement of the active headrest 3 is appropriate. The occupant's neck is more reliably protected. Further, since the pressure receiving member 8 supported by the headrest support member 7 is interposed through the lumbar support plate 29, even if the occupant is seated at an out position, that is, at a position that is not predicted, the lumbar support plate Since 29 is large, the pressure is reliably received, and the transmission of the load to the pressure receiving member 8 is ensured. Moreover, in this state, since the bent portion 20, which is the lower end of the straight portion 14, is bent forward in the shape of a "ku", the pressure receiving member 8 moves when the pressure receiving member 8 moves to the rear side RR. The space with the rear occupant is secured without protruding to the rear side RR.

Further, the stays 13, 13 of the active headrest 3 are held against the headrest holder 9.
Are supported so that they can move up and down, so that the active headrest 3 can be appropriately adjusted to the positions of the heads of occupants having different physiques.

Further, since the seat back 2 is formed in a square shape by the side frames 5 and 5, the upper cross member 10 and the lower cross member 11, the strength of the seat back 1 is remarkably improved, and a pressure in a secondary collision is received. There is no problem that the headrest support member 7 supporting the pressure receiving member 8 is deformed.

The pressure receiving member 8 is urged toward the front side FR by the return spring 12 for the active headrest and does not expand under a sitting load but can expand only under an impact load accompanying a rear-end collision. In a seated or relaxed state of the occupant, the active headrest return spring 12 does not extend in response to the backrest load of the occupant's back, and the occupant's back can be comfortably held by the S-shaped spring 35. Further, when a load due to a secondary collision due to a rear-end collision is applied, the coil spring 15a of the return spring 12 for the active headrest can be extended, so that there is no hindrance to the movement of the pressure receiving member 8, Can be moved reliably.

When the active headrest 3 is rotated to the front side FR by the secondary collision to be able to protect the occupant's neck, the stopper surface 10 of the upper cross member 10
The pressure receiving member 8 supported by the headrest support member 7 collides with the second buffer portion 16b of the buffer member 16 supported by the front head F of the active headrest 3.
Since the rotation angle to R can be limited, the occurrence of a problem that the active headrest 3 abnormally rotates to the front FR is prevented. That is, with one cushioning member 16,
Since the standing stop position and the front rotation stop position of the active headrest 3 are determined, the manufacturing cost is reduced. Also,
Position accuracy is easily obtained.

The pressure receiving member 8 corresponding to the back of the occupant, which can receive the impact load caused by the rear-end collision, is substantially I-shaped when viewed from the front and is largely protected by the lumbar support plate 29. Does not exist, an operating plate or the like for receiving pressure is unnecessary, and the cost is low, and only one pressure receiving member 8 is used.

Since the headrest support member 7 supporting the headrest holder 9 supporting the active headrest 3 is formed integrally with the upper surface portion 7a, the rear surface portion 7b, and the bracket 7d, there is no need to support each member. And there is no generation of distortion caused by supporting. Accordingly, there is no variation in the operation force of the stay 13 of the active headrest 3, and the active headrest 3 having a stable operation force can always be obtained.

Since the first through hole 19 and the second through hole 19a of the headrest support member 7 are formed in the headrest support member 7 integrally, the two through holes 19, 19a are formed.
Is reliably formed on a straight line, and can be smoothly moved up and down when the active headrest 3 is moved up and down, and no rubbing noise is generated.

FIG. 14 shows a modification of the supporting means different from the above-described embodiment. Reference numeral 40 denotes a supporting means formed by forming the lower end 29a of the lumbar support plate 29 into an inverted U-shaped cross section. The support means 40 has a support hole 4 in a plate 41 on the back side of the lumbar support plate 29.
2 are formed and supported by the lower cross member 11.

According to this modified example, the lumbar support plate 29 can be moved by the support means 40 of the lower end portion 29a of the lumbar support plate 29 having the inverted U-shaped section bent in the opening and closing direction.

In the above description, the head of the occupant is reliably held by the movement of the active headrest 3, but the movement of the active headrest 3 and the movement of the seat back 2 are relative. Even if the seat back 2 moves to the rear side RR due to the back of the occupant, the active headrest 3 does not move with respect to the occupant's head, and is held at that position, thereby protecting the occupant's head. Also included are those that are described as such.

[0055]

According to the first aspect of the present invention, the lumbar support plate can be moved in the front-rear direction by operating the lumbar support mechanism, so that the lumbar spine of the occupant can be reliably supported. can do. Moreover, since the upper end of the lumbar support plate is held by an elastic member, it does not give a feeling of pressure to the lumbar spine,
This will give a soft feeling of support to the occupant's lumbar spine.

According to the second aspect of the present invention, since the elastic member constantly urges the upper end of the lumbar support plate toward the front side, the movement of the lumbar support plate to the front side by the operating means requires a small operating force. No problem. In addition, since the secondary collision load due to the collision of the own vehicle is applied to the elastic member via the lumbar support plate, the tension can be reliably transmitted to the occupant regardless of the seating position.

According to the third aspect of the present invention, the lumbar support plate can be moved by bending the U-shaped cross section of the lower end of the lumbar support plate in the opening and closing direction.

According to the fourth aspect of the invention, the lumbar support plate can move by bending the inverted U-shaped cross section of the lower end of the lumbar support plate in the opening and closing direction.

According to the fifth aspect of the present invention, since the headrest support member supporting the headrest holder supporting the active headrest is provided between the side frames, when the secondary collision force of the occupant is generated,
The front and rear movement of the active headrest is appropriately performed, and the occupant's neck is more reliably protected. Further, since the pressure receiving member supported by the headrest support member passes through the lumbar support plate, even if the occupant is in the out position, the lumbar support plate is large. The transmission of the load can be assured.

[Brief description of the drawings]

FIG. 1 is a front view showing a seat back according to an embodiment of the present invention.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a sectional view taken along line SA-SA of FIG. 1;

FIG. 4 is an exploded perspective view of FIG. 1;

FIG. 5 is an exploded perspective view of the headrest support member of FIG. 4 as viewed from below.

FIG. 6 is a sectional view of an essential part of FIG. 5 after assembly.

FIG. 7 is an enlarged sectional view of a main part after the operation of FIG. 1;

FIG. 8 is a front view of the lumbar support plate of FIG. 1;

FIG. 9 is a side view of FIG. 8;

FIG. 10 is a sectional view taken along line SB-SB in FIG. 8;

FIG. 11 is a sectional view taken along line SC-SC of FIG. 8;

FIG. 12 is a sectional view taken along line SD-SD in FIG. 8;

FIG. 13 is a sectional view taken along line SE-SE of FIG. 8;

FIG. 14 is a side view corresponding to FIG. 9 showing a modified example of the lumbar support plate.

[Explanation of symbols]

Reference Signs List 1 automobile seat (vehicle seat) 2 seat back 3 active headrest 4 seat back frame 4a hollow portion of seat back frame 5 side frame 5a upper end of side frame 7 headrest support member 8 pressure receiving member 9 headrest holder 12 elastic member Return spring for active headrest 21 Lumbar support mechanism 29 Lumbar support plate 29a Lower end of lumbar support plate 29b Upper end of lumbar support plate 30, 40 Support means FR Front side RR Rear side UP Upper side LWR Lower side

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takahisa Tsuji 771 Koizono, Ayase-shi, Kanagawa Johnson Controls Automotive Systems, Inc. (72) Inventor Masaaki Miyazawa 771 Koizono, Ayase-shi, Kanagawa Johnson Controls Automotive Stem's F term (reference) 3B084 DB10 DB14 DC02 EB02 EC01 GA03 HA02 3B087 BD05 CD02 DB02 DC06

Claims (5)

[Claims] A seat back frame having a hollow portion, and a substantially flat lumbar support plate which covers the hollow portion of the seat back frame and has a lower end rotatably supported by the seat back frame by supporting means. A lumbar support mechanism capable of controlling a substantially intermediate portion of the lumbar support plate so as to be able to move back and forth, and a lumbar support mechanism disposed to hold the back side of the upper end of the lumbar support plate and stretched between the seat back frames. A vehicle seat, comprising: an elastic member comprising: 2. The vehicle seat according to claim 1, wherein the elastic member comprises a return spring for an active headrest which can be extended only by a secondary collision load due to a collision of the own vehicle, and is always a lumbar. A vehicle seat characterized in that the upper end of the support plate is biased forward. 3. The vehicle seat according to claim 1, wherein said supporting means is formed by forming a lower end portion of said lumbar support plate into a U-shaped cross section. Vehicle seats. 4. The vehicle seat according to claim 1, wherein the lower end of the lumbar support plate has an inverted U-shaped cross section. Vehicle seats to do. 5. The vehicle seat according to claim 1, wherein a headrest support member is installed between upper ends of the side frames of the seat back frame so as to be rotatable forward and backward. The headrest support member is provided with a headrest holder that holds an active headrest and a pressure receiving member that is adjacent to a rear surface side of an upper end portion of the lumbar support plate. A vehicle seat, wherein the vehicle seat is disposed at a position where a secondary impact load by an accompanying occupant can be received.