JP2003306065A - Seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent contact pressure from increasing in a region from buttocks to a thigh even after being seated for a long time, and to prevent an upper body from being pitched about a waist part. <P>SOLUTION: Both ends of a seat cushion and a back rest in the width direction of a seat are jointed, and a non-jointed part is provided between the jointed parts. A section corresponding to an open part 71 in a rear edge part of an intermediate cushion member 50A at the upper part of the seat is supported on a supporting shaft 42 by a plurality of supporting springs 43 arranged along the width direction of the seat. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat, and more particularly to a seat such as a vehicle seat mounted on a vehicle.

[0002]

2. Description of the Related Art A vehicle seat reduces the vibration of the driver's upper body due to cornering during driving, sudden lane changes, etc., and the burden of driving operations, and also absorbs vibrations during driving to prevent the driver from being shaken. It is important to reduce the physical burden. As a vehicle seat, a urethane sheet having urethane as a cushion material and a net sheet having a recently developed net material having a three-dimensional mesh structure (three-dimensional solid knit) as a cushion material are known.

As a urethane sheet, a sheet of urethane alone and a sheet using a support spring together are known.
In the case of the urethane seat, since the seat cushion and the backrest are separated from each other, there is a problem that a space is created between the seat and the buttocks, the supporting force of the waist is insufficient, and the hold performance is deteriorated.

The net seat is thin and exhibits high cushioning properties, has a large number of voids, and a three-dimensional three-dimensional knitted fabric having excellent breathability is stretched around the seat frame, and the cushion and the backrest are continuously formed. It is configured as a bucket type joined so as to be connected.

As shown in FIG. 16, the net seat is fixed to the seat frame on the plane of the top plate portion of the backrest 100 and the seat cushion 102, and is in the front-rear direction (X direction and Z direction) and the left and right direction. A three-dimensional three-dimensional knit 104 having different elasticity in (Y direction) is arranged. When fixing the three-dimensional three-dimensional knitted fabric to the seat frame, another three-dimensional three-dimensional knitted fabric having elasticity different from that of the top plate portion or a cloth spring is sewn around the three-dimensional three-dimensional knitted fabric of the top plate portion. Then, it is wrapped around the seat frame and fixed.

Further, the three-dimensional three-dimensional knitted fabric fixed to the seat frame is stretched at an elongation rate less than a predetermined value. However, the degree of tensioning the three-dimensional knitted fabric on the backrest top plate is continuously changed within the range of the above elongation rate in accordance with the shape of the buttocks of the human body and the S-shape of the back.

According to this net seat, since the seat cushion and the backrest are joined by the net and are continuously connected, the support rigidity of the waist portion is increased, and the holding performance is improved as compared with the urethane seat. be able to.

However, since the seat cushion and the backrest are connected to each other, when the seat is seated on the net seat, the backrest is pulled by the deformation of the seat cushion, and the net tension of the backrest causes the surface of the cushion top plate portion to be pulled. As the rigidity increases, the load on the rear edge of the seat cushion (joint portion with the backrest) increases as shown in FIG. 17, and the buttocks are pressed. As a result, when sitting for a long time, the contact pressure increases from the buttocks to the thighs,
The problem occurs.

Further, although the net seat has a smaller front-back vibration input from the backrest than the urethane seat, the upper body pitches around the waist due to the low-frequency vibration input to the waist, and it is combined with the bounce. Therefore, there is a problem in that uncomfortable feeling is generated and front-back vibration in a frequency band of 5 Hz or more becomes large.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and prevents contact pressure from increasing from the buttocks to the thighs even when the user sits down for a long time. An object of the present invention is to provide a sheet in which the pitching of the upper body is prevented.

[0011]

In order to achieve the above object, the present invention provides a seat cushion, a seat back frame attached to the seat cushion, and a backrest having a three-dimensional mesh structure stretched on the seat back frame. And a seat back having a sheet back, wherein elastic properties are different between both end portions in the width direction of the seat and a center portion in the width direction of the seat at a boundary portion between the seat cushion and the backrest. .

According to the present invention, since the elastic characteristics are made different between the widthwise both end portions of the seat and the widthwise central portion of the seat, it is possible to prevent the contact pressure from increasing from the buttocks to the thighs even when sitting for a long time. At the same time, it is possible to prevent pitching of the upper body centering on the waist.

In the present invention, it is effective to make the elastic characteristic of the central portion in the width direction of the sheet softer than the elastic characteristic of both end portions of the sheet in the width direction. In this way, the elastic characteristic of the central portion in the width direction of the seat is made softer than the elastic characteristic of both end portions in the width direction of the seat, that is, the elastic characteristic of both end portions in the width direction of the seat is adjusted to the both end portions in the width direction of the seat cushion and the backrest. If the portion is made stiffer than the elastic characteristic of the central portion in the width direction of the seat, the portion having a hard elastic characteristic can support the body side of the occupant, or the body side of the occupant and a portion outside the body side, and thus the roll or yaw. Even in the case of occurrence of, the seated person can be prevented from rotating in the roll or yaw direction. As a result, the hold performance can be improved and the fatigue during long-time operation can be reduced.

In the present invention, the seat cushion and the backrest are joined at both ends in the width direction of the seat, and a non-joined portion is provided between the joined portions of the seat cushion and the backrest. The portion corresponding to the backrest side is supported by an elastic body having an elastic coefficient equal to or less than a predetermined value, or a portion between the joint portion between the seat cushion and the backrest so that the elastic coefficient between the joint portions is equal to or less than a predetermined value. The elastic properties can be made different by joining the two.

As described above, when the seat cushion and the backrest are joined at both end portions in the width direction of the seat, the deformation of the seat cushion when seated is transmitted to the portion corresponding to the joint portion of the backrest, and the joint portion of the backrest is joined. Tension is generated in the part corresponding to the part. Therefore, the portion of the backrest where the tension is generated can support the body side of the seated person, or the body side of the seated person and a portion outside the body side, and even when a roll or yaw occurs, the seating position is reduced. It is possible to prevent a person from rotating in a roll or yaw direction. As a result, the hold performance can be improved and the fatigue during long-time operation can be reduced.

Further, a non-joint portion is provided between the joint portions of the seat cushion and the backrest, that is, the joint portions of the seat cushion and the backrest are not joined so as to be opened, and the non-joint portion of the seat cushion is opened. The portion corresponding to the backrest side is supported by an elastic body having an elastic coefficient equal to or less than a predetermined value, or a portion between the joint portion between the seat cushion and the backrest so that the elastic coefficient between the joint portions is equal to or less than a predetermined value. Are joined together.

When a non-joint portion is provided between the joined portions of the seat cushion and the backrest, that is, when the seat cushion is opened, the seat cushion is deformed when seated, and the open portion of the backrest (non-joint portion). Is not transmitted to the portion corresponding to the seat cushion, so that no tension due to the deformation of the seat cushion is generated in the portion corresponding to the open portion of the backrest. Therefore, the surface rigidity of the cushion top plate portion is reduced, the load on the rear edge portion of the seat cushion does not increase, and the contact pressure from the buttocks to the thighs does not increase when the user sits for a long time. The cushion tension is
The entire cushion is stretched so as to compensate for the change in posture due to the reduction in surface rigidity.

Further, when the portion between the joint portions of the seat cushion and the backrest is joined so that the elastic coefficient between the joint portions becomes a predetermined value or less, the seat cushion and the backrest are joined. The deformation of the seat cushion when seated is transmitted to the portion corresponding to the joint portion of the backrest. However, since the elastic coefficient between the joints is less than or equal to a predetermined value, the surface rigidity force due to the tension of the seat cushion generated in the portion corresponding to the joints of the backrest has a small value. Therefore, the load on the rear edge of the seat cushion does not increase significantly, and the contact pressure does not increase significantly from the buttocks to the thighs when the user sits for a long time.

In the present invention, in both cases of providing the non-joining portion between the joining portions and joining the joining portions, the portion of the seat cushion on the backrest side corresponding to the joining portion is Since the elastic body is supported by the elastic body having the elastic coefficient equal to or less than the predetermined value, the surface rigidity of the rear portion of the seat cushion is reduced when seated. Thereby, the body pressure in the cushion is dispersed, the skin is not locally pressed, and the skin is flexed uniformly due to vibration. That is, the strength of skin stimulation against vibration is reduced as compared with the conventional seat that is locally pressed, the riding comfort is improved, and the numbness during long-term sitting can be reduced.

The cushion tension is set so that the cushion as a whole is stretched so as to compensate for the change in the posture of depression due to the reduction in surface rigidity. Is prevented from largely sinking, and the feeling of bottoming can be suppressed.

In the present invention, in order to make the elastic characteristic of the central portion in the width direction of the seat softer than the elastic characteristic of both end portions in the width direction of the seat, the top plate portion of the seat cushion is connected to the seat back as a three-dimensional mesh structure, This can be achieved by making the structure of the central portion in the width direction of the sheet rougher than the structure of both end portions in the width direction of the sheet.

Further, the top plate portion of the seat cushion and the backrest may be sewn at the center portion in the width direction of the seat with a three-dimensional mesh structure member having elastic characteristics different from those of the backrest.

In the present invention, the center of gravity of the load when seated on the seat in each of a plurality of regions assumed to be on the left and right of the backrest surface symmetrical to the center line in the height direction of the seatback is A backrest corresponding to the dorsal region of the human body, which is surrounded by a straight line connecting the lower ends, a straight line connecting the upper ends of the left and right iliacs, and a straight line passing over the lumbar iliac costi along each of the left and right lumbar iliac costi Can be distributed outside.

By distributing the center of gravity of the load of the occupant as described above, the backrest supports the load of the occupant in a belt-like shape mainly on the outer side of the lumbar intestinal costal muscle, which is the side of the body. It is possible to reduce the supporting pressure from the buttocks, which is the center side of the person, to the lumbar region, and it is possible to suppress the occurrence of muscle fatigue (low back pain) due to poor circulation in the lumbar region, which increases the feeling of fatigue.

When the center of gravity of the load of the seated person is distributed as described above, between the straight line connecting the tops of the left and right ischium of the back region of the backrest and the straight line connecting the left and right iliac crests. It is effective that the ratio of the load acting on the lower half region to the total weight is 20% or more.

Further, the center of gravity of the load may be distributed below the region of the backrest and outside the lower region which has the same width as the region and is continuous with the region. As a result, it is possible to expand the region where it is possible to suppress the occurrence of muscle fatigue due to poor blood circulation in the lumbar spine, which increases the feeling of fatigue.

On the lower side of the area of the backrest,
It is preferable that the ratio of the load acting on the lower region having the same width as the region and continuing to the region to the total weight is 25% or less. That is, it is preferable that the load acting on the lower region extending below the back region by the width of the back region is 25% or less of the total load. As a result, the supporting load on the lumbar portion can be reduced, the muscles of the lumbar portion can be in a relaxed state, and low back pain can be reduced when sitting for a long time. The total load is the supporting load of the entire backrest when the backrest is defined as a seat portion supporting the body above the lower posterior iliac spine.

The ratio of the load to the total load is set to 25% or less as described above, because if the ratio exceeds 25%, the effect of reducing back pain is reduced.

Further, when the center of gravity of the load of the seated person is distributed as described above, the load in the region between the straight line passing through the left and right superior posterior iliac spines and the straight line passing through the left and right inferior posterior iliac spines It is preferable that the ratio to the total weight is 5% or more.

In the present invention, the tension in the horizontal direction is minimized at the portion corresponding to the horizontal line passing through the sitting posterior iliac spine height, and the tension is gradually increased from the tension minimum portion, or
The backrest can be stretched so that the slack in the horizontal direction becomes maximum at the portion corresponding to the horizontal line passing through the sitting posterior posterior spine height, and the slack becomes gradually smaller from the maximum slack portion.

By stretching the backrest having a three-dimensional mesh structure as described above, it is possible to hold the lumbar vertebrae from the buttocks of the human body so as to sink into the seatback. As a result, for example, in a vehicle, it is possible to reliably support the lateral shaking during traveling, and to reduce the burden on the lumbar region due to lack of supporting force,
It can reduce muscle fatigue in the lumbar region.

At this time, as the backrest of the three-dimensional mesh structure, a three-dimensional knitted fabric composed of an upper mesh layer, a lower mesh layer, and a pile layer having a large number of pile portions connecting the upper mesh layer and the lower mesh layer is formed. Can be used.

In the present invention, the elastic coefficient of the central portion in the width direction of the seat at the boundary portion between the seat cushion and the backrest is represented by the elastic coefficient in the normal direction when seated,
It is preferably 2 N / mm in consideration of muscle characteristics. Two
If it exceeds N / mm, the force transmitted from the seat cushion to the backrest when the seat cushion is deformed becomes large, the tension of the backrest becomes large, and the buttocks are pressed, which is not preferable.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to a vehicle seat will be described below in detail with reference to the drawings. In the present embodiment, the joint between the seat cushion and the backrest is opened so as not to be joined. In the drawings shown below, the arrow F direction is the front side in the vehicle front-rear direction, the arrow U direction is the upper side in the vehicle up-down direction (the seat height direction), and the arrow LR direction is the vehicle left-right direction (the seat width direction). ).

As shown in FIG. 1, the vehicle seat 30 includes:
The seat frame 32 is provided. Seat frame 32
Has a seat part frame 34 and a back part frame 36, and a seat cushion 38 is formed by providing a seat part cushion material on the seat part frame 34,
A seat back 40 is formed by stretching a seat back rest made of a cushion material having a three-dimensional mesh structure for the back on the back frame 36.

One end of the back frame 36 is provided at one end of the seat frame 34 along the left-right direction, and the support shaft 4 is provided.
It is connected so that it can rotate about the axis of 2.
A reclining mechanism that is rotatable in the front-rear direction is formed. The detailed description of the reclining mechanism is omitted.

The seat frame 34 includes a pair of side frames 44, and the seat cushion 38 has a plurality of coil springs 4 whose one end is supported by the side frames 44.
6 and a contour mat 48 elastically supported by the coil spring 46, and an intermediate cushion member 50 formed by an elastic body laminated on the upper surface of the contour mat 48 as a cushion material, and an intermediate cushion member. 5
The upper cushion member 52 is laminated on the upper surface of 0 and is stretched between the side frames 44. Further, as shown in FIG. 4, the intermediate cushion member 50 is configured by laminating an upper intermediate cushion member 50A and a lower intermediate cushion member 50B.

In the seat cushion 38, only the upper cushion member 52 extends forward and is folded back,
It is supported by the side frame 44 and a front end frame 44A that is stretched between the side frames 44.
As a result, the elastic compliance is increased, the damping function is increased, blood flow inhibition is suppressed, and the smoothness of pedal operation is improved when used as a driver's seat.

The intermediate cushion member 50 and the upper cushion member 52 of the seat cushion 38 are both formed of a three-dimensional three-dimensional knitted fabric which is a sheet material having a three-dimensional mesh structure described later, and the intermediate cushion member 50 is seated by an occupant. When this is done, the feeling of bottoming that occurs when only the upper cushion member 52 is arranged is suppressed, and the contour mat 48
The coil spring 46 reduces the feeling of foreign matter. The intermediate cushion member 50 may be formed by folding back the upper cushion member 52.

The intermediate cushion member 50 and the upper cushion member 52 are not limited to the three-dimensional three-dimensional knitted fabric, and any conventionally known structure using a mesh elastic member or a planar elastic member can be applied.

On the other hand, the back frame 36 of the seat back 40 is provided with a pair of side frames 54 extending in the seat height direction. The side frame 54 is provided with an elastic member made of urethane or the like. By forming this elastic member into a predetermined shape, side support portions 56 corresponding to the body side of the occupant seated on the seat 30 are formed on both sides of the seat back 40 in the left-right direction (width direction). A headrest 58 is provided in an upper portion between the side support portions 56, and a seat back rest 60 is stretched between the side support portions 56.

That is, FIG. 1 and FIG. 2 (A), FIG.
As shown in (B), the seat 30 is of a bucket type in which the seated occupant's body enters between the side support portions 56. On the surface of the side support portion 56, a surface material 56A is attached, which provides an appropriate cushioning property and a comfortable contact feeling. As the surface material 56A, a three-dimensional solid knitted fabric described later is used.

As shown in FIGS. 2 and 3 (A), the seat back 40 has an opening 62 formed by opening the space between the side support portions 56. 2 and 3 (A)
As shown in, the seat backrest 60 formed by the cushion member 64 made of a three-dimensional fabric is
The opening 62 is stretched.

That is, the seat backrest 60 is formed by the cushion member 64 stretched in the opening 62 which is the central portion facing the back of the occupant seated on the seat 30. Therefore, the seat backrest 60 formed of the cushion member 64 is provided in the side support portion 56.
Is stretched to the back frame 36 of the seat back via the.

The seat back rest 60 may be stretched directly on the back frame 36 of the seat back without the interposition of the side support portions 56.

Both widthwise end portions of the lower end portion of the seat back rest 60 are joined by sewing to both widthwise end portions of the upper cushion member 52 of the seat cushion 38. By joining in this manner, a pair of sewn joints 70A and 70B having a predetermined width is formed at the boundary between the upper cushion member 52 and the seat backrest 60 and located at both ends in the width direction of the seat.

Further, the portion between the joint portion between the upper cushion member 52 and the seat backrest 60 is open so as not to be joined. Therefore, the upper cushion member 5
An opening portion 71 having a predetermined width is formed at a portion between the joint portion between the seat backrest 60 and the seat backrest 60, that is, a portion between the sewn joint portions 70A and 70B. The width of the opening 71 is 1
50-250 mm is preferred, with an optimal value of 230 mm for 95% of Americans.

By the way, in order to carry out an accurate driving operation against the centrifugal force of the vehicle generated by the turning operation of the driver and the road surface disturbance, the wobbling of the seat cushion is made small and the holding performance of the seat supporting the whole body is improved. Need to improve. For that purpose, it is important to support the scapula, the ischium, and the front part of the thigh of the seat to prevent posture collapse.

Specifically, it is necessary to strengthen the support feeling of the seat cushion from the ischial tuberous position to 100 mm forward. Therefore, the front 20
Within the range of 0 mm and width 200 mm, if the seat cushion top plate's rigidity is maintained and the pressure force beside the ischial tubercle is reduced to give a small support feeling near the coccyx, the seat cushion rear part feels loose and wobbles. Disappear. In order to improve the top plate support pressure, an elastic body with an elastic coefficient different from that of the seat cushion is provided at the rear part of the seat surface, and a light support pressure is applied to the coccyx. , The vibration characteristics are improved. However, it is preferable to use a duffing type elastic coefficient having weak nonlinearity so that the feeling of bottoming is not increased.

Therefore, the upper intermediate cushion member 50A
A portion of the rear end edge portion corresponding to the open portion 71 at the seat backrest side edge portion is supported by the support shaft 42 by a plurality of support springs 43 arranged along the seat width direction. The elastic coefficient of the elastic portion formed by the plurality of support springs 43 and the rear end edge of the upper intermediate cushion member 50A is approximately zero in the seated state.
It is preferably 30 to 50 N / mm.

As described above, in the present embodiment, the widthwise ends of the upper cushion member 52 are connected to the seat backrest 6.
A body-side support structure is formed by joining the corresponding parts of 0 to reduce the lateral vibration of each part of the upper body. Further, by supporting the edge portion of the upper intermediate cushion member 50A corresponding to the opening portion 71 by the support spring 43, the tension of the backrest due to the cushion deformation due to sitting is only transmitted through both ends of the opening portion 71. Since the back-and-forth force of the backrest due to the bending of the cushion is reduced, the occupant mainly vibrates vertically. As a result, the holding performance is improved, and a high-frequency vibration is improved by approaching the one-degree-of-freedom vibration model of the cushion spring constant and the human body mass.

Although an example in which the backrest side portion of the seat cushion is supported by supporting the upper intermediate cushion material with the support spring has been described above,
The backrest side portion of the seat cushion may be supported by supporting the lower intermediate cushion material or the rear edge of the upper cushion material, and the backrest of the seat cushion may be adjusted by adjusting the elastic coefficient of the intermediate cushion material. You may make it support a side part.

Next, the three-dimensional knitted fabric used as the cushion member will be described with reference to FIGS.

As shown in FIG. 5, the three-dimensional knitted fabric 80
Is a pair of ground knitted fabrics 8 arranged apart from each other.
2 and 84, and a pile portion 88 formed by a large number of connecting threads 86 that reciprocate between the pair of ground knitted fabrics 82 and 84 to join them.

One ground knitted fabric 82 is, for example, as shown in FIG.
As shown in, a yarn 90 in which short fibers are twisted to form a mesh with a flat knitted fabric structure that is continuous in both the wale direction and the course direction is used. Further, the other ground knitted fabric 84 forms a honeycomb mesh from yarns 92 obtained by twisting short fibers, as shown in FIG. 7, for example. The other grand knitted fabric 84 has a larger mesh than the one grand knitted fabric 82. The ground knitted fabrics 82 and 84 are not limited to the thin structure and the honeycomb structure, and other mesh-shaped knitted fabric structures may be used.

As shown in FIG. 5, the connecting yarn 86 is knitted between the ground knitted fabrics 82 and 84 so that the one ground knitted fabric 82 and the other ground knitted fabric 84 maintain a predetermined space, and the pile is formed. The portion 88 is formed. As a result, the three-dimensional knit 80, which is a mesh knit, is given a predetermined rigidity.

The three-dimensional three-dimensional knit 80 is a ground knitted fabric 8.
Although the necessary waist strength can be provided by the thickness of the ground yarns (threads 90, 92) forming the yarns 2, 84, the ground yarns 90, 92 are in a range that does not make knitting work difficult. Is preferably selected. Although monofilament yarns can be used as the ground yarns 92, 92, multifilament yarns or spun yarns may be used in consideration of the texture, the softness of the surface feel, and the like.

It is preferable to use a monofilament yarn as the connecting yarn 86, and the thickness thereof is preferably in the range of 167 decitex to 1100 decitex. With multifilament yarn, cushioning properties with good restoring force cannot be obtained, and when the thickness is less than 167 decitex, the waist strength of the three-dimensional three-dimensional knit 80 decreases, and
If it exceeds the decitex, it will become too hard and the proper cushioning will not be obtained.

That is, by using a monofilament thread of 167 decitex to 1100 decitex as the connecting thread 86, the load of the occupant seated on the seat is
With the deformation of the mesh forming the ground knitted fabrics 82, 84,
The connecting yarns 86 forming the pile portion 88 can be supported by the deformation due to tilting or buckling, and the restoring force of the adjacent connecting yarns that impart spring characteristics to the deformed connecting yarns 86.
A flexible structure having a soft spring characteristic and free from stress concentration can be obtained.

The three-dimensional three-dimensional knit 80 may be provided with irregularities. That is, the ground knitted fabrics 82, 84 may be knitted so as to have unevenness on the surface, and when the unevenness is formed, spring elements having a substantially arch-shaped cross section can be formed on the ground knitted fabrics 82, 84. Because,
A soft spring characteristic can be imparted, and a structure having an elastic compliance substantially equal to or greater than the elastic compliance of muscle can be easily formed. The elasticity compliance is (deflection amount) /
It is calculated by (average pressure value of contacting surfaces).

The materials for the ground yarns 90, 92 and the connecting yarn 86 are not particularly limited, and examples thereof include synthetic fibers such as polypropylene, polyester, polyamide, polyacrylonitrile, rayon, regenerated fibers, wool,
Examples include natural fibers such as silk and cotton. These materials may be used alone or in any combination. Preferably, polyethylene terephthalate (P
ET), thermoplastic polyester fibers represented by polybutylene terephthalate (PBT), nylon 6,
Polyolefin fiber typified by nylon 66,
Alternatively, two or more kinds of these fibers are combined.

Further, the ground yarns 90 and 92 and the connecting yarn 8
The thread shape of 6 is not limited to the above description, and a thread having a round cross section, a thread having an irregular cross section, or the like may be used.

The pile structure of the pile portion 88, which is a method of arranging the connecting yarns 86 forming the pile portion 88, is shown in a side view of the connecting yarns 86 connecting the ground knitted fabrics 82 and 84. It can be classified into the types shown in FIGS. 8 (A) to 8 (E).

8 (A) and 8 (B) show a straight type in which the connecting yarn 86 is knitted substantially vertically between the ground knitted fabrics 82, 84. Of these, FIG. 8 (A) shows It is formed into a letter shape and is straightly woven, as shown in FIG. 8 (B).
Is a simple straight knit.

Further, FIG. 8C, FIG. 8D, and FIG.
(E) shows a cross type in which the connecting yarn 86 is knitted so as to intersect midway between the ground knitted fabrics 82 and 84. Of these, FIG. 8 (C) shows the connecting yarn 86 crossed in the shape of a figure 8, and FIG. 8 (D) shows the connecting yarn 86 simply crossed. Also, FIG.
In (E), two connecting yarns 86 are collected together and crossed (double crossed).

As shown in FIGS. 8 (C) to 8 (E), when the connecting yarns 86 are arranged diagonally so as to intersect with each other, the connecting yarns 86 are almost perpendicular to each other between the ground knitted fabrics 82, 84. 8A and 8B (see FIG. 8 (A) and FIG. 8 (B)), a soft spring characteristic with a large compression ratio is provided while maintaining a sufficient restoring force due to the buckling strength of each connecting yarn 86. There is an advantage that can be done.

Cushion members 52 and 64 using such a three-dimensional three-dimensional knit 80 have a low spring property and a high damping ratio, are easily deformed to follow the occupant's body shape, and are more easily fitted. It should be noted that the cushion member 64 of the seat back 40 and the widthwise both ends of the upper cushion member 52 of the seat cushion 38 are integrated by the three-dimensional knitted fabric 80 by stitching, so that when the occupant is seated, a large load is applied to the occupant. The part facing the lumbar region from the buttocks can be supported like a hammock in a direction in which the occupant can float from the buttocks to the lumbar region. This makes it easier to follow changes in the posture of the occupant and improves the feeling of sitting.

By the way, the three-dimensional three-dimensional knit 80 stretched as the cushion member 64 on the seat back rest 60 of the seat back 40 has an opening 6 as shown in FIG. 3 (B).
It is cut using a template 68 formed in a predetermined shape so as to match the template 66 that fits the two openings.

The pattern paper 68 has a predetermined height h from the seam joints 70A and 70B with the upper cushion member 52 of the seat cushion 38, which is the end portion on the seat cushion 38 side.
Between the two, a predetermined height h1 from the sewing joints 70A, 70B
It is formed so that it is widest most. Thereby, when the cushion member 64 is stretched on the seat back 40,
The seat backrest 60 is designed to be most loosened at a height h1 from the seat cushion 38.

That is, the cushion member 64 obtained by cutting the three-dimensional three-dimensional knit 80 using this paper pattern 68 is stretched on the seat backrest 60, whereby the cushion member 6 is formed.
4 is the position of height h1 from the sewn joint 70, where the slackest occurs. Further, the slack gradually decreases from this position toward the position of the seam joint 70 and the height h2, and when the height exceeds the height h2, the tension is kept within several percent.

The width dimension W0 of the pattern 68 at this height h1
Is larger than the width dimension WS of the corresponding portion of the pattern paper 66 by a predetermined widening rate α. That is, W0 = WS ×
(1 + α). In the present embodiment, as an example, the widening ratio α is set so that the width dimension W0 is wider than the width dimension WS by 4% (α = 0.0).
4).

As a result, the seat backrest 60 is
A cushion member 64 is stretched between the sewn joint 70 and the height h2 so that the slack is maximized at the position of the height h1.

On the other hand, the height h1 and the height h2 are set based on the figure of the person sitting on the seat 30. That is, the height h1 is set based on the sitting posterior iliac spine height, which is a position corresponding to the vicinity of the upper end of the iliac of a person seated on the seat 30, and the height h2 is the lower end of the clavicle. It is set based on the sitting scapula inferior angle, which is the position corresponding to.

The sitting posterior superior iliac spine height is the height from the seat surface at which the superior posterior iliac spine 16A of the ilium 16 shown in FIG. The average number of young men is 1
54.3 mm, the average for young women is 149.1 m
m, the average for young men and women is 151.8 mm. In addition, the average for middle-aged men, women, and middle-aged men and women is 1 each.
Since the height is 52.2 mm, 136.1 mm, and 144.3 mm, the height h is an example in the present embodiment.
1 is set to 150.0 mm.

The sitting scapula inferior angle height is the height from the seat surface of the scapula inferior angle 12A, which is the lower end of the scapula 12, and the average of Japanese adolescent males, adolescent females and adolescent males and females is 4 respectively.
It is 56.9 mm, 416.1 mm, and 437.2 mm. In addition, the averages of middle-aged men, women, and middle-aged men and women are 427.2 mm, 377.2 mm, and 401.1, respectively.
Since it is mm, the height h2 is set to 450.0 mm in the present embodiment in consideration of this numerical value.

In the seat 30, the width dimension of the opening 62 is set so that the side portion of the seated occupant is held by the side support portion 56. As a result, FIG. 3 (B)
Width Wa at height h2 on paper pattern 68 shown in FIG.
Is set based on the width of the lower corner of the scapula. The inferior scapular width is the linear distance between the inferior scapular angles 12A of the left and right scapula 12 shown in FIG. 9 (A), and the average of Japanese adolescent males, adolescent females and adolescent males and females is 194.7 mm, respectively. 1
It is 63.8 mm and 179.8 mm. In addition, the average of males, females, and males and females of mature years is 187.
It is 6 mm, 161.2 mm and 174.3 mm. From here, the width dimension Wa is made sufficiently wider than the width of the lower corner of the scapula so that the upper body of a person seated in the seat backrest 60 of the seat 30 can be accommodated and the seat backrest 60 can be accommodated. It is set so that the body side part at the time comes into contact with the side support part 56 forming the peripheral part of the opening part 62.

The three-dimensional three-dimensional knit 80 is attached to the cushion member 64.
When it is stretched as, it is possible to use any joining method. At this time, the surface material 5 of the side support portion 56
It is preferable to properly join the 6A and 6A so as to give a sense of unity. For example, when a cloth material such as felt is used as the surface material 56A, it is preferable to sew the cushion member 64 from the surface material 56A, thereby suppressing the lateral extension of the three-dimensional solid knit 80. On the other hand, it is possible to make it easy for elongation to occur in the vertical direction. Therefore, the deformation following the body shape of the human body is likely to occur, and the holding property and the stability at the time of sitting can be further improved.

In this way, the cushion member 64 formed by cutting the three-dimensional three-dimensional knit 80 is stretched, so that the seat back rest 60 of the seat back 40 is
A bending portion 72 is formed around a position of height h1 from the seat surface. As a result, the seat backrest is stretched so that the slack in the horizontal direction becomes maximum at the portion corresponding to the horizontal line passing through the sitting posterior posterior spine spine height, and the slack becomes gradually smaller from the maximum slack portion.

At this time, by tensioning the three-dimensional knitted fabric 80 as the cushion member 64 on the seat backrest 60, the spring property is lowered, the damping ratio is increased, and the upper body can be supported in a hammock shape. Become.

The upper body of the person seated on the seat 30 is accommodated between the side support portions 56, so that the back surface thereof faces the cushion member 64 stretched on the seat backrest 60. At this time, it faces the flexible portion 72 of the seat backrest 60 from the buttocks to the lumbar region.

At the bending portion 72, the cushion member 64 is provided.
The width dimension W0 is wider than the width dimension WS of the opening 62, and when the person sits down deeply, the lumbar region from the buttocks is accommodated in the seat backrest 60 so as to be wrapped in the cushion member 64. That is, the hips are accommodated and held from the buttocks so as to sink into the cushion member 64.

Further, the upper body is held by the side portions of the upper body contacting the side support portions 56. At this time, the central portion of the upper body abuts on the cushion member 64 stretched so as to close the opening 62. The cushion member 64 has a tension of several% or less at a portion above the height h2, but slightly bends in a region below this, so that the cushion member 64 is below the height h2. The upper body is wrapped and held by the cushion member 64 at the portion. Ie sheet 3
At 0, compared with the conventional S-shaped holding of the spine, which is conventionally in an appropriate sitting state, the person sits in a slightly stooped state.

Next, the distribution of the center of gravity of the seat backrest when seated in the vehicle seat of the present embodiment configured as described above will be described. First, Fig. 9 (A)
As shown in FIG. 2, a line 14 connecting the inferior scapula 12A and 12B of the human body 10 sitting on the seat cushion, a line 18 connecting the left and right iliac crests, and a line 2 passing on the lumbar iliac costal muscle (not shown).
Assume a back region 22 surrounded by zeros. At this time,
The line 20 passing on the lumbar iliac costus is approximately the position connecting the lower end of the scapula 12 and the upper end of the ilium 16.

As shown in FIG. 9B, a plurality of seat backrests are arranged symmetrically with respect to the back region 22 with the center line 24 along the height direction being sandwiched therebetween. The center of gravity when a load is applied to each of the divided regions 26 is distributed outside the back region 22. Note that FIG.
In (B) and FIG. 9 (C), the position of the center of gravity of the seat to which the present embodiment is applied is shown by a black circle, and the position of the center of gravity of a general seat having a conventional structure is shown by a black square.

As a result, the backrest supports the load of the seated person in a band-like shape mainly on the outer side of the lumbar intestinal costal muscle, which is the side of the body, and supports the seated person from the buttocks to the lumbar vertebra. It is possible to reduce the pressure, and it is possible to suppress the occurrence of muscle fatigue (backache) due to poor circulation in the lumbar spine, which increases the feeling of fatigue.

As shown in FIG. 9A, the back region 2
Assuming a lower region 28 extended by the width of the spine region 22 on the lower side of 2, the lower region 2 as shown in FIG. 9 (B).
The center of gravity of the load received by each of the regions 26 connected to each other is located outside the lower region 28.

As shown in FIG. 9A, the back region 2
The load acting on the lower region 28 extending to the lower side by the width of the spine region is about 13% or less of the total load.
As a result, the supporting load on the lumbar region can be reduced, the muscles of the lumbar region can be in a relaxed state, and low back pain can be reduced when sitting for a long time. Note that the total load is defined as the total load is the support load of the entire backrest when the backrest is defined as a seat portion that supports the body above the lower posterior iliac spine 16B (see FIG. 9A). There is.

FIG. 10B shows the measurement result of the body pressure distribution applied to the seat back 40 when the user sits on the seat 30. Further, FIG. 10C shows an example of the body pressure distribution on the seat back of the seat that has been conventionally optimized.

By the way, the cross-sectional shape of the back of the human body 10 projects backward from the spine 10A toward the body side. In particular, the scapula 12 and the bone portion of the superior posterior iliac spine 16A have a large protrusion.

On the other hand, a portion of the scapula 12 that extends from the scapula 12 to the ilium 16 and has a large posterior overhang is the ridge of the lumbar intestinal costal muscle not shown in this figure. When a person having such a back shape is seated on the seat, the shoulder blade 12, the upper posterior iliac spine 16A bone portion, and the muscle portion of the lumbar iliac costal muscle come into contact with each other at a high body pressure. Further, the cause of muscle fatigue in sitting for a long time is that the load acting on the muscles, that is, the body pressure becomes high and the blood vessels around the muscles are pressed, thereby impeding blood circulation.

Therefore, in order to reduce the muscle fatigue, it is necessary to consider the load burden on the major longissimus thoracic muscle and the lumbar iliac costus on the left and right along the spine. Therefore, the burden on the muscle was evaluated, and the area as the seat design requirement was set as follows.

That is, as shown in FIG. 10A (see also FIG. 9A), a line 14 connecting the lower ends (lower scapular angle 12A) of the left and right shoulder blades 12 of the human body 10 and the left and right iliac crests Line 18 that connects the lower scapula 12A and the line that connects the iliac crest
When the area surrounded by the back area 22 is defined as the back area 22, the seat 30 has a seat backrest 60 in the back area 22.
The cushion members 64 that are stretched over are opposed to each other. At this time, the line 20 that connects the lower scapula 12A and the iliac crest is on the left and right of the spine 10A of the human body and runs along the lumbar iliac costal muscle along the vertical direction.

On the other hand, in the seat backrest 60 of the present embodiment, the sewn joint portions 70A, 7A of the cushion member 64 are formed.
The position from 0B to the height h2 corresponds to the line 14 at the upper end of the back region 22.

Further, a region 28 extended by the width of the back region 22 is provided.
At the center of the is the posterior superior iliac spine 16A. The flexure portion 72 that is most loosened at a height h1 from the seam joint portions 70A and 70B of the cushion member 64 shown in FIG.
This is the position of the upper posterior iliac spine 16A when seated.

As a result, as shown in FIG. 10 (B), the body pressure distribution in the back region 22 of the seat back 40 in the seat of the present embodiment is shown in FIG. It can be seen that the body pressure is relatively low and the body pressure is high outside the line 20 in the back region 22 as compared with. Further, the body pressure is low in the lower end line 18 of the dorsal region 22, that is, in the vicinity of the line connecting the left and right iliac crests, and in the region 28 extending from the dorsal region 22, and at the outside of the region 28 on the left and right sides. The pressure is high.

This difference in body pressure distribution is due to the fact that the cushion member 64 of the backrest is loosened in accordance with the shape and size of the human body. That is, the flexure 72 of the height h1 of the superior posterior iliac spine 16A, which has a large bulge of the buttocks, is maximized, and the tension is set to several% or less when applied to the height h2 of the inferior scapular angles 12A and 12B. Since the cushion member 64 formed by cutting the three-dimensional three-dimensional knit 80 in accordance with the shape of the body is deformed by the installation, the ridge line in the transverse section of the back, that is, the portion in contact with the body side from the lumbar intestinal costal muscle. The body pressure becomes high.

When the line 18 at the lower end of the dorsal region 22 is hung under the ischial tuberosity, the cushion member 64 wraps the lumbar region from the buttocks by the flexure 72 at the height of the superior posterior iliac spine 16A. Housed in. Therefore, from the buttocks to the lumbar region, the net (cushion member 64) is started from the ridgeline in the cross section of the human body, that is, from the left and right lines of the region 28.
The body pressure increases at the body side that is in contact with.

On the other hand, in FIG. 9 (B), the center of the load in each region 26 is assumed, assuming a region 26 which is symmetrically divided by the seat back 40 of the seat 30 with the center line 24 interposed therebetween. The position of the center of gravity is created based on the pressure distribution shown in FIG. Further, FIG. 9C shows the load ratio of the upper and lower divided regions with respect to the supporting load of the backrest created based on the pressure distribution of FIG. 10B. This load ratio graph is for the seat back 40
The load ratio at each area position with respect to the total load received by is shown. 9 (B) and 9 (C), the center of gravity and the load ratio of the seat 30 are indicated by black circles, and the conventional example based on FIG. 10 (C) is indicated by black squares.

As shown in FIG. 9B, conventionally, the center of gravity of the load is located in the back region 22 and the region 28, whereas in the seat 30, the center of gravity of the load is located in the back region. 22
The position is far from the area 28. That is, conventionally, the body side can receive the pressure mainly on the back.

The supporting load distribution from the buttocks to the lumbar region of the conventional seat is 5th just below the line 18 of the iliac crest.
The load ratio increases near the lumbar spine, and the load ratio sharply decreases below that. This is because the cushion and the backrest are separated and there is a gap between the buttocks and the backrest.

On the other hand, the sheet of this embodiment is
Since the cushion member 64 formed by cutting the three-dimensional solid knit 80 in accordance with the shape of the body is deformed, the straight line passing through the left and right superior posterior iliac spine 16A and the left and right inferior posterior iliac spine 16B (FIG. 9).
The load ratio in the area between the straight line passing through (A) and FIG. 10 (A) is 10% or more, and there is no sudden change in the supporting load, and the load is evenly distributed. Further, the center of gravity is on the body side of the region 28, and the load ratio of the region 28 exceeds 35% in the conventional sheet calculated based on FIG. It is around.

As a result, in the seat 30, the supporting pressure on the lumbar region of the human body 10 can be reduced as a whole, so that the occurrence of poor blood circulation due to the high supporting pressure can be suppressed. That is, the supporting pressure does not interfere with blood circulation.

Further, even when the upper body is supported on a vehicle, the upper body is supported in a belt-like manner on the body side from the shoulder to the buttocks, due to the vibration of the upper body caused by the vibration while the vehicle is running. There is no shortage, and in order to compensate for the lack of support, it is possible to prevent unnecessary force from entering the lumbar region.

Therefore, the muscles of the lumbar vertebrae are kept in a relaxed state, and the occurrence of low back pain due to long-term sitting can be suppressed.

Further, in the conventional vehicle seat, when traveling on a swell road and an asphalt road surface, the cushion is greatly deformed due to low frequency vibration. In particular, when the cushion sinks, the net tension of the backrest increases and the longitudinal force acts on the lumbar region.As a result, the upper body combines the pitching of the upper body centered on the lumbar region and the bounce vibration, and Pleasure increases. On rough roads, high frequency vibration is the main component, so while the upper body does not respond to the longitudinal force due to the tension of the backrest, the vibration is transmitted to the waist.
The ride comfort of high-frequency vibration deteriorates.

On the other hand, in the net seat according to the present embodiment, since the central portions of the cushion and the backrest are open, the backrest due to the depression of the cushion even when traveling on a swell road or an asphalt road surface. Since the tension of the is greatly reduced, the longitudinal force acting on the waist is also reduced, pitching of the upper body is suppressed, and high-frequency vibration is also difficult to be transmitted. That is, by opening a part of the joint between the cushion and the backrest, it is possible to reduce the pitching and longitudinal vibration of the upper body, which were the problems of the conventional net seat against simple vertical vibrations, and to sit down for a long time. It is possible to significantly reduce the feeling of increase in contact pressure from the cushion.

Further, since the cushion and the backrest are connected on both sides of the open portion, the body side support performance can be maintained, and the roll performance and yaw rotation are not performed, so that the hold performance and the fatigue reduction in a long time driving are impaired. Never.

Further, by supporting the rear end of the cushion opening portion and the frame with an elastic body such as a spring having a smaller elastic modulus than that of the cushion, a support feeling near the tailbone can be provided, and the back of the buttocks at the time of sitting and vibration input. The wobble feeling that accompanies the roll disappears.

In the above description, an example in which the joint between the seat cushion and the seat backrest is opened without joining and an opening is provided between the joints has been described. You may make it join the part between the junction parts of a seat cushion and a backrest so that the elastic coefficient between them may become below a predetermined value.

In FIG. 11, the portion between the joint between the upper cushion member 52 and the seat backrest 60, that is, the portion corresponding to the open portion 71 described above is sewn with the thread 120 and loosened. Similar to the above, the part is supported by the support shaft 42 by a plurality of support springs 43. In FIG. 12, a three-dimensional three-dimensional knitted fabric 122 having a small elastic coefficient is interposed between the joint between the upper cushion member 52 and the seat backrest 60, and is sewn and loosened by the thread 120.

11 and 12, the elastic coefficient of the elastic portion composed of the plurality of support springs and the trailing edge portion of the upper cushion member 52, and the three-dimensional knitted fabric and the trailing edge of the upper cushion member 52. The elastic coefficient of the elastic portion composed of the portion and the elastic portion is set to a value of 2 N / mm or less when expressed by the elastic coefficient in the normal direction of the three-dimensional knitted fabric that acts on the buttocks when seated.

In the above description, an example in which the elastic coefficient is set to a predetermined value or less by interposing a three-dimensional three-dimensional knitted fabric in the portion between the joint between the cushion member and the seat backrest has been described. The elastic coefficient may be set to a predetermined value or less by making the pile structure of the part corresponding to the knitted fabric coarser than the other parts. The elastic coefficient may be set to a predetermined value or less by knitting with a thread having a small elastic coefficient, that is, a thread that easily expands and contracts.

Further, the present embodiment described above shows an example of the present invention and does not limit the configuration of the present invention. For example, in the present embodiment, the seat provided in a vehicle such as an automobile has been described as an example, but the seat of the present invention is not only a vehicle such as an automobile but also a seat for a person such as an aircraft seat or furniture. If so, it can be applied to various sheets. In particular, it can be used as a seat that sits for a long time, or as a seat that is subject to vibration or shaking.

Next, a vibration test conducted for confirming the effect of the longitudinal vibration absorption of the seat of this embodiment will be described. In this experiment, as shown in FIG. 13, a small uniaxial acceleration sensor was attached at a height position that would be the third lumbar vertebra when the floor feet and the backrest were stopped left and right, and a human being was seated while vertically vibrating with a random waveform. The vertical acceleration Gzh at the foot of the floor and the longitudinal acceleration G of the backrest.
The transfer characteristics of xw were investigated.

FIG. 14 shows the front-back vibration transmission characteristics of the conventional net seat and the net seat of the present embodiment. As shown in the figure, the net sheet of the present embodiment is 4 to 13H.
It can be understood that in the z frequency band, the gain is lower than that of the conventional net sheet, and the vibration absorption is significantly improved. The vibration peak near 5 Hz is the resonance in the front-back direction due to the spring element of the backrest and the human body.

Further, if the joint between the cushion and the backrest is partly opened, the influence of the back-and-forth force of the backrest is reduced, and the simple 1-degree-of-freedom vibration system model by the spring element of the cushion and the human body is approached as much as possible. Means that. Therefore, as shown in FIG. 13, the vibration transfer characteristics between the vertical acceleration Gzf and the vertical acceleration Gzh by the acceleration sensor installed in the lower part of the ischium of the cushion with respect to the vertical excitation acceleration Gzf were examined and compared with the conventional net seat.

As a result, the conventional net sheet is 5 Hz.
Although the gain is the largest and the resonance phenomenon is seen, 5H
There is a gain of 1 or more up to the frequency band of z to 11 Hz, which is different from the vibration characteristic waveform having a simple one degree of freedom.

On the other hand, the net sheet of this embodiment has about 3.
It can be said that a resonance phenomenon is observed at 6 Hz, and the gain is sharply reduced at frequencies higher than that, which is a vibration characteristic having a characteristic of a simple one-degree-of-freedom system. Therefore, in the seat of the present embodiment, it can be understood that the vibration gain is reduced at the resonance frequency of 5 Hz or more, which is the resonance frequency of the conventional net seat, and the riding comfort is significantly improved.

The net sheet of this embodiment has a resonance frequency lower than that of the conventional net sheet, but has a resonance gain of 1.5 in comparison with the conventional net sheet.
It becomes 0 and a little over 1.3 times. However, considering the balance between the magnitude of the shock input to the buttocks and the damping time of the vibration, the vibration gain transmitted from the floor to the cushion seems to be optimal at around 2.0. Rather, the fact that the gain is small like the conventional net seat means that the vibration damping is large and the impact input to the buttocks is also large.
It is rated as a uncomfortable seat. In this way, by opening a part of the joint between the cushion and the backrest, the front-back force of the backrest due to the depression of the cushion is significantly reduced, so that the riding comfort can be significantly improved.

[0120]

As described above, according to the present invention, both widthwise end portions of the seat cushion and the backrest are joined, and a non-joint portion is provided between the joined portions of the seat cushion and the backrest. A portion of the seat cushion corresponding to the non-joint portion is supported by an elastic body having an elastic modulus of a predetermined value or less, or a joint portion between the seat cushion and the backrest is adjusted so that the elastic coefficient between the joint portions is a predetermined value or less. Since the parts are joined, it is possible to provide a seat that prevents contact pressure from increasing from the buttocks to the thighs even when sitting for a long time and prevents pitching of the upper body centered on the waist. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a schematic perspective view in which a part of a vehicle seat of the present embodiment is cut away.

FIG. 2A is a front view of a vehicle seat according to the present embodiment, and FIG. 2B is a side view.

FIG. 3A is a schematic front view of the seat showing a state in which a cushion member is not stretched on the seat back, and FIG. 3B is a schematic diagram showing a pattern of the cushion member stretched on the seat back.

FIG. 4 is a cross-sectional view showing a part of a cross section taken along the height direction center line of the vehicle seat of the present embodiment.

FIG. 5 is a schematic sectional view showing a three-dimensional three-dimensional fabric used as a cushion member.

FIG. 6 is a schematic view showing an example of one ground knitted fabric used for a three-dimensional solid knitted fabric.

FIG. 7 is a schematic view showing an example of another ground knitted fabric used for a three-dimensional solid knitted fabric.

8 (A) to (E) are schematic cross-sectional views of a main part of a three-dimensional solid knitted fabric showing an example of application of a pile part.

FIG. 9A is a schematic view showing a skeleton of a human body, and FIG. 9B is a schematic view showing a distribution of a center of gravity of a load on a seat back.
(C) is a schematic diagram showing the distribution of the load ratio to the seat back.

FIG. 10 (A) shows a skeleton of a human skeleton.
A schematic view similar to (A), (B) a schematic view showing a load distribution to a backrest of a seat applied to the present embodiment,
(C) is a schematic diagram showing an example of load distribution to the backrest of the conventional seat.

FIG. 11 is a cross-sectional view showing a part of another example of the joint portion between the seat backrest and the upper cushion member.

FIG. 12 is a cross-sectional view showing a part of still another example of the joint portion between the seat backrest and the upper cushion member.

FIG. 13 is a schematic view showing the mounting positions of the acceleration sensor on the floor and before and after the backrest.

FIG. 14 is a diagram showing a comparison of the vibration transmission gains before and after the floor and backrest of the conventional example and the present embodiment.

FIG. 15 is a diagram showing a comparison between the vertical vibration transmission below the ischial tuberosity node and the vibration transmission gains before and after the backrest between the conventional example and the present embodiment.

FIG. 16 is a perspective view showing a net sheet using a conventional three-dimensional solid knitted fabric.

FIG. 17 is a perspective view showing load distribution of a seat cushion in a urethane seat and a net seat.

[Explanation of symbols] 10 human body 12 Shoulder blade 12A Lower scapula 14, 18, 20 lines 16 ilium 16A Superior posterior iliac spine 22 Back area 24 center line 26 areas 28 areas 30 sheets 38 seat cushion 40 seat back 56 Side support section 60 seat backrest 64 cushion member 71 Open section 80 three-dimensional knitted fabric 88 pile section

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Eiichi Yasuda             Aichi Prefecture Nagachite Town Aichi District             Ground 1 Toyota Central Research Institute Co., Ltd. (72) Inventor Shunichi Doi             Aichi Prefecture Nagachite Town Aichi District             Ground 1 Toyota Central Research Institute Co., Ltd. (72) Inventor, Etsuko Kato             Aichi Prefecture Nagachite Town Aichi District             Ground 1 Toyota Central Research Institute Co., Ltd. (72) Inventor, Etsunori Fujita             2-10 Yanoshinmachi, Aki-ku, Hiroshima-shi, Hiroshima             Issue Delta Touring Co., Ltd. (72) Inventor Yumi Ogura             2-10 Yanoshinmachi, Aki-ku, Hiroshima-shi, Hiroshima             Issue Delta Touring Co., Ltd. (72) Inventor Seiji Kawasaki             2-10 Yanoshinmachi, Aki-ku, Hiroshima-shi, Hiroshima             Issue Delta Touring Co., Ltd. F-term (reference) 3B087 DA01 DB04 DE03

Claims (11)

[Claims] 1. A seat comprising a seat cushion and a seat back having a seat back frame attached to the seat cushion and a backrest having a three-dimensional mesh structure stretched on the seat back frame. A seat in which elastic properties are different between both end portions in the width direction of the seat at the boundary portion between the cushion and the backrest and the center portion in the width direction of the seat. 2. The sheet according to claim 1, wherein the elastic characteristic of the central portion in the width direction of the sheet is made softer than the elastic characteristic of both end portions of the sheet in the width direction. 3. The seat cushion and the backrest are joined at both end portions in the width direction of the seat, a non-joint portion is provided between the joined portions, and a portion of the seat cushion on the backrest side corresponding to the non-joint portion has an elastic coefficient. Is supported by an elastic body having a predetermined value or less, or the portion between the joining portions of the seat cushion and the backrest is joined so that the elastic coefficient between the joining portions is not more than a predetermined value. The sheet described in. 4. The seat cushion top plate portion is connected to the seat back as a three-dimensional mesh structure, and the structure of the central portion in the width direction of the seat is made coarser than the structure of both end portions in the width direction of the seat. The sheet according to claim 3. 5. A top cushion portion and a backrest of a seat cushion are sewn with a three-dimensional mesh structure member having elastic characteristics different from those of the backrest in a widthwise central portion of the seat.
The sheet according to claim 3. 6. The elastic coefficient in the normal direction of the portion of the boundary portion between the seat cushion and the backrest, which is in contact with the buttocks of the seated person, is set to 2 N / mm or less. The sheet described in. 7. The center of gravity of the load when seated on the seat in each of a plurality of regions assumed on the left and right of the backrest surface symmetrically with the center line in the height direction of the seatback,
The dorsal region of the human body, which is surrounded by a straight line connecting the lower ends of the left and right shoulder blades, a straight line connecting the upper ends of the left and right iliacs, and a straight line passing over the lumbar iliac costi along each of the left and right lumbar iliac costi The seat according to any one of claims 1 to 6, wherein the seat is distributed outside the backrest corresponding to. 8. The center of gravity of the load is distributed below the region of the backrest and outside the lower region continuous with the region with the same width as the region. Sheet. 9. The ratio of the load acting on a lower region, which has the same width as the region and is continuous with the lower region, below the region of the backrest, to the total weight, is 25% or less. Alternatively, the sheet according to claim 8. 10. A ratio of a load to a total weight in a region between a straight line passing through the left and right superior posterior iliac spines and a straight line passing through the left and right posterior iliac spines is 5% or more. ~ The sheet according to any one of claims 9 to 10. 11. The tension in the horizontal direction is minimized at a portion corresponding to a horizontal line passing through the posterior iliac spine height above the sitting position, and the tension gradually increases from the minimum tension portion, or the slack in the horizontal direction is above the sitting position. 11. The backrest is stretched so that the maximum amount is reached at a portion corresponding to a horizontal line passing through the posterior spine and the looseness is gradually reduced from the maximum loosened portion. Sheet.