JPH07327773A - Seat back structure - Google Patents

Abstract

PURPOSE:To keep a natural seating attitude by forming U-shaped torsion parts which form an operating arm part, a torsion bar part and a fixed arm part respectively on support rod parts of upper and lower torsion bars where a support plate is hooked, and setting the length of the operating part part of the upper part smaller than that of the lower part. CONSTITUTION:Upper and lower torsion bars 35, 37 fitted to an outer peripheral frame respectively comprise support rod parts 35a, 37a, and torsion parts 36, 38, wherein the torsion parts 36, 38 form operating arm parts 36a, 38a, torsion bar parts 36b, 38b, and fixed arm parts 36c, 38c, and are bent to be substantially U-shaped. The lengths A, B of the operating arm parts 36a, 38a of the torsion bars 35, 37 are related by the following expression: A>B. When external force is applied to a support plate 31 hooked on the torsion bars 35, 37, the upper side is displaced more largely than the lower side by a difference between the lengths A and B. Accordingly, it is possible to prevent a stooped posture due to sinking of the back side and push-out feeling of the waist.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat including a seat cushion and a seat back, and more particularly to a seat back structure.

[0002]

2. Description of the Related Art Conventionally, as a structure of a seat frame 2 in a seat back 1 of this type, as shown in FIG. 6, an outer peripheral frame 3 is formed by bending a pipe material.
The upper frame 4, the left and right side frames 5, and the lower frame 6 are formed into a substantially rectangular frame body. The headrest brackets 7 are attached to the upper frame 4 at predetermined intervals. A side wire 8 is attached in an overhanging manner. Also,
Between the left and right side frames 5, S-shaped springs 9a, 9b, 9c are hooked on a hooking member (not shown) attached to the side frame 5 from the upper side at a predetermined interval, and the S-shaped springs 9a, 9b, 9c are hooked. Springs 9a, 9
The vertical wire springs 1 are formed in a substantially quadrangular shape as shown in FIGS.
0 is attached via a clip member 11. Further, as another configuration, as shown in FIG. 7, there is a configuration in which the lumbar support 12 is attached via the torsion bar 13 instead of the lower S-shaped springs 9c attached to the left and right side frames 5. As shown in FIGS. 8, 9 and 10, a seat back pad 15 is attached to the seat frame 2 provided in this way in an enclosing manner, and the seat back pad 15 and the backrest portion 16 at the center and the left and right sides are attached. And the back holder 16 is supported by the S-shaped springs 9a, 9b, 9c and the vertical wire spring 10, and
The side holder portion 17 is supported by the side wire 8,
Although not shown, a skin material is covered on the outer periphery of the seat back pad 15 to form the seat back 1.

[0003]

However, in this conventional seat back 1, the S-shaped springs 9a, 9b,
9c and the vertical wire spring 10 are connected by the clip member 11, so that the occupant is seated and the seat back 1 is seated.
When the person leans on the back, the entire surface of the backrest portion 16 does not bend, and the deflection in the vicinity of the central portion thereof becomes large, so that the occupant tends to be in a back posture, and there is a problem that the occupant is uncomfortable and tired easily. However, since the lower part of the seat back 1 is partially extruded, there is a problem that the balance of the support as the whole surface is poor and it tends to be extremely extruded, which causes a feeling of strangeness. Also, the side support is S-shaped. Spring 9
Since the a, 9b, and 9c are mounted laterally, there is a problem that the bending of the central portion becomes large and a feeling of lateral pressure easily occurs.

The present invention has been made to solve the above-mentioned conventional problems. When the occupant is seated on the seat, the upper body of the occupant can be kept in a natural posture, and the work such as driving can be performed. An object of the present invention is to provide a seat back structure that can be held in a suitable final posture.

[0005]

SUMMARY OF THE INVENTION In order to solve the above technical problems, the present invention is hooked and supported by torsion bars mounted above and below between left and right side frames of a substantially rectangular outer frame, and the upper and lower parts thereof are supported. A support plate having a concave concave part on the back and a convex part on the waist that follow the curve of the final seating posture is hooked on the torsion bar, and the operating arms and the torsion bar are provided at both ends of the horizontal supporting rods of the upper and lower torsion bars. And the fixed arm portion respectively form a substantially U-shaped torsion portion, and the lengths of the operation arm portions of the left and right upper torsion portions are longer than the lengths of the operation arm portions of the lower left and right torsion portions. Further, the seat back structure has torsion springs on the left and right of the upper and lower torsion bars.

[0006]

The upper body of the occupant is supported by the support plate having the concave back surface and the convex waist surface, and the displacement amount of the upper side of the support plate is large due to the difference in the lengths of the operating arms of the upper and lower torsion portions, The amount of displacement is given small, there is no need to have a stoop posture due to depression on the back side unlike in the past, and the feeling of pushing out the waist can be prevented, giving a spring feeling to the entire support surface, This functions to increase the support pressure of the human pelvis and the lumbar vertebra to ensure a stable posture.

[0007]

1 is a perspective view of a seat back frame 22, and FIG. 2 is a supporting plate 31, upper and lower torsion bars 35, 37 and a bracket 29. 30 is a perspective view showing the relationship with the seat back 30, FIG. 3 is a partial horizontal sectional view of the seat back 22, and FIG. 4 is a vertical sectional view. The seat frame 22 of the seat back 21 includes an outer peripheral frame 23, a support plate 31, and It consists of upper and lower torsion bars 35 and 37,
The outer peripheral frame 23 is formed by bending a pipe material as in the conventional case, and is formed into a substantially rectangular frame body by the upper frame 24, the left and right side frames 25, and the lower frame 26.
Head brackets 27 are attached at predetermined intervals, and side wires 28 are attached to the left and right side frames 25 in a protruding manner. Also, the left and right side frames 2
The upper bracket 29 of the upper torsion bar 35 and the lower bracket 30 of the lower torsion bar 37 are attached to the upper and lower predetermined positions of 6 by welding means or the like.
Key-shaped hooking grooves 29a for hooking and fixing 5, 37,
30a is pierced.

The support plate 31 is made of a synthetic resin material, a molded hard board, a spring plate, etc., and is formed in a substantially rectangular shape having a predetermined backrest width h. Edges are formed on both sides of the backrest width h. The portion 32 is formed, and a concave groove portion 33 having a substantially U-shaped cross section is provided in the central portion, and the concave groove portion 33 is formed.
Ribs 33a are formed at predetermined intervals. Also,
As shown in FIG. 3, the support plate 31 has a horizontal cross section which is curved in a concave shape toward the concave groove portion 33 in a predetermined range on the upper side thereof, and as shown in FIG. 1 on the lower side. A curved back concave surface 31a and a waist convex surface 31b that are formed in a curved shape in a convex shape and that substantially follow the curves of the back (thoracic vertebra) and the waist (lumbar vertebra) in the final posture in a seated state are formed. The edge 32 side is provided with the ability to bend in the direction of the arrow in the figure. Further, as shown in FIG. 2, the upper and lower torsion bars 3 are provided at predetermined positions above and below the groove 33.
A hook-shaped hooking groove 34 is formed to hook and lock 5, 37. In addition, in FIG. 2, the engaging groove 34 of the support plate 13 is shown so as to be inverted.

Next, the upper and lower torsion bars 35, 37 for engaging and supporting the support plate 31 will be described. The upper and lower torsion bars 35 and 37 are formed in substantially the same shape, and are formed by bending a piano wire, a hard steel wire or the like having a predetermined diameter. The upper torsion bar 35 has a predetermined shape. A horizontal support rod portion 35a having a mounting length of 1 and a torsion portion 36 are integrally bent at both ends thereof. The torsion part 36 is bent from the end of the support rod part 35a by a predetermined length A to form an operating arm part 36a.
A torsion bar portion 36b which is horizontally bent in the opposite direction with a predetermined length L is formed from the end portion of 6a. The torsion bar portion 36b is formed from the end portion of the torsion bar portion 36b in parallel with the operating arm portion 36a by a length A. The fixed arm portion 36c is formed, the torsion portion 36 is bent into a substantially U shape, and the upper end of the fixed arm portion 36c is engaged with the retaining groove 29a of the upper bracket 29 attached to the outer peripheral frame 23. Engaging claw 3
6d is formed.

Further, the lower torsion bar 37 has a horizontal support rod portion 37a having a predetermined mounting length, and a torsion portion 38 is integrally bent at both ends thereof.
Similar to the torsion portion 36, the torsion portion 38 is bent from the end portion of the support rod portion 37a by a predetermined length B to form an operating arm portion 38a. The end portion of the operating arm portion 38a is formed. A torsion bar portion 38b that is bent horizontally in the opposite direction with a predetermined length L is formed, and the operation arm portion 38a is formed from the end of the torsion bar portion 38b.
A fixed arm portion 38c having a length B is formed in parallel with the fixed arm portion 38c, and the torsion portion 38 is bent into a substantially U-shape. The lower end of the fixed arm portion 38c has a lower bracket 30 attached to the outer peripheral frame 23. Engaging claws 38d that are engaged with the engaging grooves 30a are formed. The operation arm portions 36 of the upper and lower torsion bars 35, 37 formed in this way
The lengths A and B of a and 38a are provided in the relationship of A> B.

The upper torsion bar 35 thus formed is hooked in the hooking groove 29a of the upper bracket 29 attached to the outer peripheral frame 23 via the fixed arm portion 36c. End 29b,
The distance a of 29c is a with respect to the length A of the fixed arm portion 26c.
The relationship of ≧ A is satisfied. The torsion bar portion 36b of the torsion portion 36 of the fixed arm portion 36c is inserted into the end portion 29b of the hooking groove 29a while being positioned, and the engaging claw at the end portion of the fixed arm portion 36c. 36d is engaged with the end 29c, and an E-ring 39 is attached to the engaging claw 36d to prevent the engagement from coming off. Similarly, the lower torsion bar 37 is also hooked in the hooking groove 30a of the lower bracket 30 attached to the outer peripheral frame 23 via the fixed arm portion 38c. The end portion 30b of the hooking groove 30a,
The distance b of 30c is b with respect to the length B of the fixed arm portion 38c.
There is a relation of ≧ B. An E-ring 39 is attached to the engaging claw 38d at the end of the fixed arm portion 38c thus locked to prevent it from coming off.

The support plate 31 is engaged with and supported by the upper and lower torsion bars 35 and 37 thus mounted via the upper and lower engaging grooves 34. When an external force acts on the support plate 31 in this state, the support plate 31 is also supported. The left and right actuating arm portions 36a and 38a of the upper and lower torsion bars 35 and 37 with which the plate 31 is hooked are torsion bar portions 36b and 38, respectively.
It is rotated about b, whereby a torsional force acts on the torsion bar portions 36b and 38b, and the support plate 31 is displaced rearward. This displacement is caused by the lengths A and B of the operating arm portions 36a and 38a. Support plate 3 due to the difference of
The upper side of 1 will be displaced more than the lower side,
When the external force is released, it is restored to its original position by the torsion restoring force of the torsion bar portions 36b and 38b. When the seat back pad 15 is attached to the seat frame 22 provided in this manner in a wrapped manner, the support plate 31 moves to the backrest portion 1.
The seat back 21 is formed by fittingly contacting a recess 16a formed on the back surface of the seat 6, and covering the outer periphery of the seat back pad 15 with a skin material (not shown).

Since the seat back 21 of this embodiment is formed as described above, when an occupant sits down and leans back on the seat back 21, the seat back pad 15 has a right side and a left side of the outer frame 23 on the back side. Concave portion 31a and waist convex surface 3 that substantially follow the curve of the final posture that is hung and supported by the torsion bars 35 and 37 mounted above and below the side frames 25 of
A support plate 31 having a support 1b is in contact therewith, and the torsion bars 36, 37a of the upper and lower torsion bars 35, 37 are respectively provided at both ends thereof.
38 is formed, and the length A of the operating arm portion 36a of the upper torsion portion 36 is formed longer than the length B of the operating arm portion 38a of the lower torsion portion 38. The upper body is supported by the support plate 31 having the back concave surface 31a and the waist convex surface 31b, and the displacement S1 of the upper side of the support plate 31 due to the difference between the length A of the operating arm 36a and the length B of the operating arm 38a. Is large, and the displacement amount S2 on the lower side is small (see FIG. 4), it does not have to be a cat-back posture due to a depression on the back side unlike the conventional case, and the feeling of pushing out the waist can be prevented, It is possible to give a feeling of spring to the entire surface, which can increase the support pressure of the human pelvis and the lumbar vertebra to ensure a stable posture, and also to give the human shoulder a degree of freedom. Wear. Further, by providing the concave groove portion 33 in the central portion of the support plate 31, the human spinal column can be supported straight, and a comfortable sitting posture can be secured.
Since the left and right edge portions of the support plate 31 are provided with the bending ability, it is possible to improve the fit feeling of the side portions. Further, the upper and lower torsion bars 35 and 37 are attached by engaging with the retaining grooves 29a and 30a of the upper and lower brackets 29 and 30 attached to the outer peripheral frame 23, and the support bracket 31 has its concave groove portion. Engagement groove 3 formed in 33
Since it is configured to hang on the support rods 35a, 37a of the upper and lower torsion bars 35, 37 via 4, the assembling work can be performed extremely labor-saving, and the number of work steps can be reduced. Further, it is possible to reduce the number of parts management steps by eliminating the fastening members such as clips.

In the above embodiment, the torsion portions 36 and 3 are provided on the left and right sides of the upper and lower torsion bars 35 and 37, respectively.
Although the number 8 is integrally formed as an example, the present invention is not limited to this and may be the configuration of the torsion bar 41 shown in FIG. 5, for example. That is, the torsion bar 41 has a support rod portion 42 made of a pipe material having a predetermined horizontal diameter.
A torsion spring (torsion portion) 43 is attached to the left and right of the support rod portion 42. The torsion spring 43 has a coil portion (torsion bar portion) 44 having a predetermined number of turns and a predetermined length A at one end of the coil portion 44.
An operating arm portion 45 (or length B) is formed, and a fixing portion 46 that is fitted and fixed to the supporting rod portion 42 by welding means is formed at the end portion thereof, and the other end of the coil portion 44 is operated. A fixed arm portion 47 having a length A (or a length B) corresponding to the arm portion 45 is formed, and an engaging claw 48 is formed at the end portion. Torsion bar 4 formed in this way
Reference numeral 1 denotes an E-ring 3 whose coil portion 44 is inserted through a support pin 50 provided at a predetermined position of a bracket 49 attached at a predetermined position of the left and right side frames 25 of the outer peripheral frame 23.
9. The engaging claw 48 of the fixed arm portion 47 is prevented from coming off by 9
Is an engaging hole 5 formed at a predetermined position of the bracket 49.
It is inserted in 1 and is prevented from coming off by an E ring 39. In this case, the space between the support 50 and the engagement hole 51 is formed to have the dimension A (or the dimension B). By adopting the torsion bar 41 formed in this way, the same operational effects as those of the above-described embodiment can be obtained. In addition,
Other configurations are the same as those in the above embodiment.

[0015]

Since the present invention is configured as described above, when an occupant sits on a seat and leans back on the seat back, the occupant's upper body has a support plate having a concave back surface and a convex waist surface. The displacement amount on the upper side of the support plate is large and the displacement amount on the lower side is small due to the difference in the lengths of the operating arms of the upper and lower torsion parts. It is possible to prevent the lumbar part from pushing out and to give a feeling of spring to the entire support surface, which raises the support pressure of the human pelvis and the lumbar vertebra to maintain a stable posture. It can be ensured and the human shoulder can be given a degree of freedom. In addition, the recessed groove portion 3 is formed in the center of the support plate 31.
By providing 3, the human spinal column can be supported straight and a comfortable sitting posture can be secured, and the support plate 3
(1) Since the left and right edges are provided with the bending ability, the fit feeling of the side portions can be improved. Further, the upper and lower torsion bars are attached to the engaging grooves of the upper and lower brackets attached to the outer peripheral frame, and the support bracket is attached to the upper and lower portions through the engaging grooves formed in the concave groove portions. Since it is configured to hang on the support rod of the torsion bar,
The assembling work can be performed extremely labor-saving, and the work man-hours can be reduced, and the fastening members such as clips can be eliminated to reduce the man-hours for parts management.

[Brief description of drawings]

FIG. 1 is a perspective view of a seat back frame.

FIG. 2 is a perspective view showing a relationship between a support plate, upper and lower torsion bars, and a bracket.

FIG. 3 is a partial horizontal sectional view of a seat back.

FIG. 4 is a vertical sectional view of a seat back.

FIG. 5 is a partial cross-sectional view showing another aspect of the torsion bar.

FIG. 6 is a perspective view of a conventional seat back frame.

FIG. 7 is a perspective view of another conventional seat back frame.

FIG. 8 is a horizontal sectional view of a conventional seat back.

FIG. 9 is a vertical sectional view of the seat back.

10 is a partial vertical cross-sectional view of the lower side of the seat back to which the seat back frame of FIG. 7 is attached.

[Explanation of symbols]

 21 seat back 22 outer peripheral frame 25 side frame 31 support plate 35, 37, 41 torsion bar 35a, 37a, 42 support rod part 36, 38, 43 torsion part 36a, 38a, 45 working arm part 36b, 38b, 44 torsion bar part 36c, 38c, 47 Fixed arm part

Claims (2)

[Claims] 1. A seat back structure, which is hung and supported by a torsion bar mounted above and below between left and right side frames of a substantially rectangular outer frame, and a final posture of seat seating on the upper and lower torsion bars. A support plate having a concave concave part on the back and a convex convex part on the waist is attached to the upper and lower portions of the horizontal supporting rods of the torsion bar, and the operation arm part, the torsion bar part and the fixed arm part are provided at both ends. A seatback structure in which U-shaped torsion portions are formed respectively, and the lengths of the operation arms of the left and right upper torsion portions are longer than the lengths of the operation arms of the left and right lower torsion portions. 2. The seat back structure according to claim 1, wherein the torsion portions are torsion springs on the left and right of the upper and lower torsion bars.