WO2015147268A1

WO2015147268A1 - Seat cushion

Info

Publication number: WO2015147268A1
Application number: PCT/JP2015/059644
Authority: WO
Inventors: 伊東　博之; 恵北崎; 村田　誠志郎; 塩谷　暁
Original assignee: 株式会社東洋シート; 株式会社ジェイエスピー
Priority date: 2014-03-28
Filing date: 2015-03-27
Publication date: 2015-10-01
Also published as: JPWO2015147268A1

Abstract

Provided is a seat cushion that comfortably fits to a user sitting thereon, has good cushioning properties, realizes weight reduction and is highly recyclable. The seat cushion comprises: a seat cushion pad that is provided with a seating face to be in contact with the user's lower thighs and hips, formed of a synthetic resin foam, and capable of undergoing bending deformation downward; a space that is positioned below the seat cushion pad and allows the bending deformation of the seat cushion pad; a seat cushion frame that is disposed below the seat cushion pad to be apart therefrom; and an elastic body supporting the seat cushion pad. When no load is applied, the seat cushion pad is supported not by the seat cushion frame but by the elastic body.

Description

Seat cushion

The present invention relates to weight reduction of a seat cushion, and particularly relates to a seat cushion for a vehicle, a ship, an aircraft, a chair or the like that is rich in recyclability, fit, and cushioning.

Generally, a vehicle seat cushion includes a metal seat frame and a wire, and generally urethane foam is used as a cushioning material and is entirely covered with a skin material. The load of the user is supported mainly by bending the urethane foam layer sandwiched between the seat frame or wire and the skin material in the compression direction, and the cushioning and fitting properties are mainly compressed by the urethane foam layer. It was obtained by the reaction force, the restoring force and the bending when bent in the direction.

Further, as a technique related to weight reduction of a vehicle seat cushion, Patent Document 1 shows a frame shape of a seat frame, a cross section of the seat frame has a mountain shape, and one side of the mountain shape on a frame shape inner peripheral side of the seat frame. A concave curved surface is formed by covering the seat frame with an elastic net and pulling the periphery of the seat frame from the top of the chevron and fixing it to the other side of the chevron. A technique is disclosed in which the seating surface is stretched so as to form a seating surface, and an angle is provided between the net and the inclined surface of the seat frame.

As another technique related to weight reduction, Patent Document 2 discloses a base plate detachably attached to a seat frame, a block disposed on the base plate, a spring plate disposed on the block, and the spring plate. And the block is disposed so as to form a predetermined space between the base plate and the spring plate, and the spring plate is PP (elastic foam). Polypropylene) beads foam, PE (polyethylene) beads foam, PP foam, PE foam, AS resin (acrylonitrile / styrene resin) foam, EVA (ethylene vinyl acetate copolymer resin) and urethane foam material The spring sheet is molded from the formed foam. It is a technique related to a vehicle seat flexes the space is disclosed when a force to said base plate direction was added.

JP 2002-28044 A Japanese Patent No. 4009490

In conventional general vehicle seat cushions, urethane foam is used as a cushioning material and is still frequently used because of its extremely high cushioning properties and excellent comfort. However, the urethane foam has a problem that it is inferior in recycling performance. Furthermore, in addition to being required to have optimal cushioning properties regardless of the weight of the user's weight, the vehicle seat cushion has a negative effect on the user's body against vertical acceleration applied to the user as the automobile moves. Functions that do not give pleasure are also required. In order to reduce fatigue when riding for a long time, it is necessary to secure cushioning and support the body so as not to cause discomfort. For this reason, the function cannot be satisfied with only a very lightweight and flexible urethane foam, and in order to obtain a certain degree of rigidity, the density of the urethane foam needs to be a certain level or more. There was no problem.

In the technique described in Patent Document 1, the net material that supports the load by the user is drawn into the seat frame installed around the seat cushion and firmly fixed, and the load applied by the seating of the user is transmitted through the net material. Ultimately, it was supported by the rigidity of the seat frame. Therefore, the structure of the seat frame must maintain a certain level of strength. For this reason, although the weight of the net material itself corresponding to the conventional cushion material is light, the weight of the seat frame tends to increase and the overall weight There was a problem that the reduction effect was not sufficient.

Furthermore, the cushioning property of the net material is limited because it is obtained mainly by the elongation of the material, and there is a tendency that sagging occurs due to long-term use and the merchantability is inferior. In addition, since the flat net material is stretched around the seat frame, the basic seat cushion shape is flat, and the three-dimensional shape necessary to support the user's body in an optimal position is obtained. As a result, there is a problem that the user feels uncomfortable. This is because an unstable hammock-like net material cannot stably support the user's body when a lateral G is applied to the user by the movement of the automobile.

Next, regarding the technique of Patent Document 2, the spring plate is a plate-like foam having a substantially rectangular outer shape, and a plurality of grooves are formed in the lateral direction on the side on which the user of the spring plate is seated. However, if the groove is shallow, flexibility cannot be given, and if the groove is deep, when the cushion material bends, excessive tensile force concentrates on the connecting part of the remaining groove bottom, causing large elongation deformation. There was a high risk of permanent deformation that could not be restored or fracture. If even a part of the connecting portion at the groove bottom is broken, the support is lost at once, the apparent hardness of the entire cushioning material is drastically lowered, and the function as the cushioning material is greatly impaired. Therefore, it is practically difficult to design the deflection of the cushion material to a certain level or more in order to avoid breakage, and it is difficult to provide a sufficient fit and comfort when seated.

Moreover, although the technique of patent document 2 has described that a favorable seating feeling can be obtained personally by selecting suitably the block from which height differs according to a user's physique, There was a problem that it was difficult to implement practically, because it was necessary to change the block to a height suitable for oneself before sitting down due to the weight of the weight.

Therefore, an object of the present invention is to provide a seat cushion that is rich in fit and cushioning when seated by a user, can be reduced in weight, and is highly recyclable.

In the present invention, the synthetic resin foam is flexible, capable of bending deformation, and has excellent resilience. The method described in JIS K7221-2: 2006 (23 ° C. ± 2 ° C., relative humidity 50 ± 350mm long with skin removed in 5% atmosphere
A load is applied to a test piece having a width of 100 mm and a thickness of 25 mm at a fulcrum distance of 300 mm and a test speed of 20 ± 1 mm / min until the maximum deflection is 90 mm, and a load deflection curve is recorded. ) Is a synthetic resin foam molded article having a bending deflection of 20 mm or more measured in accordance with (2) and a load of 2 to 100 N at the time of 20 mm deflection. Specifically, it refers to foamed polypropylene, foamed polyethylene, other polyolefin resin foams, modified polystyrene resin foams, and the like. The synthetic resin foam includes a bead foam molded body, and examples of the bead foam molded body include a polypropylene-based bead foam molded body and a polyethylene-based bead foam.

In the specific selection of the material, both ends of a bar-like or plate-like test piece having a length of about 400 mm are supported, the center is pushed back and forth by 25 mm and held for 30 minutes, and then the load is released to recover from the deformation of the sample. 90% or more is desirable. Alternatively, in accordance with a test performed on a conventional urethane foam seat cushion, the center portion of the sample supporting both ends is repeatedly pressed down and deformed a predetermined number of times, and the residual strain (also referred to as residual displacement) measured thereafter is measured. It is desirable that the amount is not more than a predetermined amount.

Such materials satisfying, for example of expanded polypropylene density ^{0.06g / cm 3 ~ 0.015g / cm} 3, more preferably a density ^{0.035g / cm 3 ~ 0.015g / cm} 3 or polyethylene foam, A density of 0.08 g / cm ³ to 0.03 g / cm ³ is preferable. On the other hand, rigid foamed urethane, polystyrene foam and the like which are poor in flexibility and can be easily broken by bending deformation are not preferable.

The inventors have studied materials in order to reduce the weight. As an example of a material that can be changed to urethane foam with an open-cell structure, synthetic resin foam that has a closed-cell structure is generally lighter and more rigid than urethane foam that has been generally used as a cushioning material for seat cushions. It has the advantage that it is rich and easy to recycle, but when using a cushion in the direction of compression and restoring force, the reaction force tends to increase rapidly with the deformation of the foam due to the repulsive force of the encapsulated air Therefore, it was felt that the cushioning property was lacking and the comfort was inferior.

In general, when a synthetic resin foam having a closed cell structure is used as a cushioning material by being bent in the compression direction like a urethane foam, it gradually loses its recovery force and generates creep as it is used for a long period of time. This is largely due to fatigue due to repeated deformation of the resin film constituting the bubbles and a drop in the pressure of the air contained therein. Therefore, it is not preferable as a material for automobile seat cushions used for a long time.

Therefore, the inventors analyzed the physical properties of the synthetic resin foam from various angles, so that it is not a structure that has been bent in the compression direction that has been used as a conventional general cushioning material, but can be bent and deformed. The present inventors have found that a method of utilizing the bending deformation and recoverability of a support made of a synthetic resin foam excellent in the above as a cushioning material is optimal.

In general, a general-purpose synthetic resin foam having a closed cell structure has an elastic range of about 2 to 5% for compression and tension. When bending deformation occurs on the surface of the seat surface that exhibits cushioning properties due to bending deformation, compressive deformation or tensile deformation occurs on the front surface or back surface, respectively. Although it shows, in the range beyond this, it is inferior in recoverability and a deformation | transformation accumulates. In the case of a seat cushion, the amount of displacement necessary to obtain a good seating feeling with the seat cushion is large, and it is only necessary to bend and deform the seat surface, which is a support made of synthetic resin foam and supported at both ends. When trying to obtain the amount of displacement, the degree of deformation exceeds the elastic range of the synthetic resin foam, and there is a concern that the deformation accumulates at every seating, leading to the present invention.

In order to solve the problem described in “Problems to be Solved by the Invention”, the invention of the seat cushion 2 according to claim 1 includes a seat surface on which a user's thigh lower part and a buttock abut, and a synthetic resin foam A seat cushion pad 4 that is composed of a body and bends and deforms downward, a space 10 that allows the seat cushion pad 4 to be bent and deformed below the seat cushion pad 4, and a space below the seat cushion pad 4. The seat cushion frame 5 and the elastic body 8 that supports the seat cushion pad 4 are provided, and the seat cushion pad 4 is not supported by the seat cushion frame 5 but is supported by the elastic body 6 when no load is applied. It is characterized by that.

The seat cushion 2 according to claim 2 is provided with the side support portion 21 in the form separated from the seat cushion pad 4 on the left and right end sides of the seat cushion pad 4 with which the flange portion 50 abuts. It is characterized by.

The seat cushion 2 according to claim 3 is the seat cushion 2 according to

claim

1 or 2, wherein the synthetic resin foam has a bending deflection amount measured according to the method of JIS K7221-2: 2006 of 20 mm or more and 20 mm deflection. Is a synthetic resin foam having a load of 2 to 100 N.

According to a fourth aspect of the present invention, the seat cushion 2 according to the second aspect of the present invention is configured such that the front view configuration of the boundary surface 23 between the seat cushion pad 4 and the side support portion 21 is directed outward in the downward direction from the upper end. It is characterized by comprising a slanted form.

The seat cushion 2 according to a fifth aspect of the present invention is the seat cushion 2 according to any one of the first to fourth aspects, wherein the elastic body is disposed on a bottom surface of the seat cushion pad 4 except for a range in which the user's rib is in contact with the seat cushion pad 4. 6 is provided with protrusions such as ribs 30 projecting downward so as to abut against 6.

The seat cushion 2 according to a sixth aspect is the seat cushion 2 according to any one of the first to fourth aspects, wherein the center portion of the seat cushion pad 4 is supported by the elastic body 6 in plan view, and the front and rear ends of the seat cushion pad 4 and / or The left and right ends are cantilevered, and the front and rear ends and / or the left and right ends of the seat cushion pad 4 are curved upward.

A seat cushion 2 according to a seventh aspect is the invention according to any one of the first to sixth aspects, wherein a thin plate-like body 31 is interposed between the bottom surface of the seat cushion pad 4 and the elastic body 6. Features.

The seat cushion 2 according to claim 8 is characterized in that, in any one of claims 1 to 8, a recess is formed on the surface of the seat cushion pad 4 so as to follow the collar portion 50 when the user is seated. To do.

A seat cushion 2 according to a ninth aspect of the present invention is the seat cushion 2 according to any one of the first to eighth aspects, wherein the seat cushion pad 4 and the side support portion 21 are covered, or the skin 9 that covers the seat cushion pad 4 is covered with the bottom surface of the seat cushion pad 4. On the side, it is locked by a locking member 32 attached to the left and right ends of the skin 9 or a locking member 32 attached to a cloth-like body 33 sewn to the left and right ends of the skin 9. .

In the invention of the seat cushion 2 according to the first aspect, it is possible to replace the conventionally used urethane foam with a synthetic resin foam. Therefore, weight reduction and improvement in recyclability can be achieved. It is possible. Despite the use of synthetic resin foam, which is relatively hard and inferior to cushioning, fit, and creep resistance, it is possible to give high cushioning and fit, and freedom of design High level of comfort and high comfort can be obtained, and even with long-term use, it exhibits good creep resistance equivalent to that of conventional urethane foam, so it has a high commercial value. Play.

As a form of the seat cushion 2 according to the first aspect, for example, there is a form A in which the seat cushion pad 4 is separated from the seat cushion frame 5 in the vertical direction when there is no load. The seat cushion pad 4 is always separated from the seat cushion frame 5 in the up-down direction when loaded by the user, or the seat cushion pad 4 is separated from the seat cushion frame 5 in the up-down direction when the user is seated. Then, there is a form C in which the seat cushion pad 4 comes into contact with the seat cushion frame 5 in the vertical direction by the sinking of the seat cushion pad 4.

In the case of the form A, the seat cushion pad 4 descends with a certain reaction force of the elastic body 6 due to elastic deformation such as elastic expansion and contraction of the elastic body 6 supporting the seat cushion pad 4 at the same time when the user is seated. Therefore, a good seating feeling can be obtained from the time of sitting. The seat cushion pad 4 that descends while being supported by the elastic body 6 has a load magnitude for each part captured in a plan view of the seat cushion pad 4 according to the body part such as the posture of the user and the rib part. By being different, the concave deformation is caused according to the magnitude of the load applied to each part of the seat cushion pad 4. Due to this dent deformation, the user can have a flexible impression and feel a comfortable seating feeling.

Therefore, the seat cushion pad 4 is lowered by the elastic deformation of the elastic body 6 and the deformation of the seat cushion pad 4 being dented from the portion other than the portion where the pressure is concentrated, so that the user may have a soft contact and sink the body. You can feel a comfortable cushion.

Next, at the time of loading by the user, in the case of the structure of form B, the same effect as the effect described in form A is obtained.

When the load applied by the user is Form C, after the seat cushion pad 4 descends and comes into contact with the upper end of the seat cushion frame 5, the seat cushion pad 4 is lowered in a state where both ends are supported with the seat cushion frame 5 as a fulcrum. The cushioning property according to the load of the user can be exhibited by the upward reaction force generated by bending deformation of the elastic body 6 and the upward reaction force of the elastic body 6. In the case of this structure, the user can comfortably cushion that the contact with the body sinks softly due to the lowering of the seat cushion pad 4 due to the elastic deformation of the elastic body 6 in the first stage and the concave deformation of the seat cushion pad 4. In addition to the elastic deformation of the elastic body 6 in the second stage, the bending deformation of the both ends supporting beams of the seat cushion pad 4 and the bending deformation of the seat cushion pad 4 with the seat cushion frame 5 as a fulcrum The user receives the impression that the seating surface is sufficiently flexible and can feel a comfortable cushioning property.

In any form of the seat cushion 2, the user's load W is applied to the elastic body 6 that supports the seat cushion pad 4, and the load is distributed to the elastic body 6 and the seat cushion pad 4. Since the load applied to the seat cushion pad 4 can be reduced, the seat cushion pad 4 is bent and deformed to exhibit cushioning properties when receiving the load W caused by the seating of the user, but the deformation range is kept within the elastic range. In addition, since the elastic body 6 is lowered, the user can feel that the seating surface is sufficiently flexible and can have a favorable seating feeling.

The invention of the seat cushion 2 according to claim 2 has the same effect as that of claim 1, and at the same time, the seat cushion pad in which the buttocks of the user who seats at least the seat cushion pad 4 and the side support portion 21 abuts. By separating the left and right end portions of the side support portion 21, the side support portion 21 is not drawn toward the center without being pulled by the bending deformation of the seat cushion pad 4 when the user is seated, so that the user feels pressure from the side support portion 21. The effect of not feeling. Moreover, since the material of the side support part 21 can also be set to a material different from the synthetic resin foam of the seat cushion pad 4, for example, the effect that the hardness of the side support part 21 can be arbitrarily set according to the use of the seat is also possible. Play.

The invention of the seat cushion 2 according to claim 3 has the same effect as that of

claim

1 or 2, and the conventional urethane foam, despite using a relatively hard synthetic resin foam. It has the effect of exhibiting the same good creep resistance.

The invention of the seat cushion 2 according to the fourth aspect has the same effect as that of the second aspect, and the seat cushion pad having a substantially vertical shape from the left and right ends of the seat cushion pad 4. 4 because the reaction force at the left and right end portions of the seat cushion 2 is high, there is a problem that the cushioning property of the seat cushion 2 is lowered. Since the seat cushion pad 4 is bent, the reaction force at the left and right end portions of the seat cushion pad 4 is reduced by bending deformation of the oblique portion when the user is seated. The reaction force generated in the seat cushion pad 4 of the seat cushion 2 is equalized over a wide range of the seat cushion pad 4. Achieve the results.

The invention of the seat cushion 2 according to claim 5 has the same effect as the effect of any one of claims 1 to 4, and makes the user feel a comfortable seating feeling without feeling uncomfortable with the sensitive buttocks in the body. There is an effect.

The invention of the seat cushion 2 according to claim 6 has the same effect as that of any one of claims 1 to 4, and the form of the seat cushion pad 4 further conforms to the seated person's buttocks 50. Therefore, the body pressure can be more positively distributed, and the left and right ends and / or the front and rear ends are cantilevered and bent according to the load on the user's body. Thus, when the lateral acceleration is applied and the body is tilted, the higher followability of the seat cushion 2 can be felt. Unlike the form in which the seat cushion pad 4 is supported at both left and right ends, the seat cushion pad 4 is cantilevered according to the user's physique and is bent and deformed so that the curved shape is opened upward. It is easy to fit the body and can improve body pressure dispersion and comfort.

The invention of the seat cushion 2 according to the seventh aspect has the same effect as the invention according to any one of the first to sixth aspects, and comes into contact with the seat cushion pad 4 made of a synthetic resin foam so that the seat cushion pad 4 is By interposing a hard thin plate-like body 31 between the elastic body 6 to be supported, permanent deformation that tends to occur can be prevented. Further, when comparing the cushioning properties when the thickness of the seat cushion pad 4 alone and the thickness when the seat cushion pad 4 and the thin plate-like body 31 are combined are the same, the case of the seat cushion pad 4 alone is compared. The cushioning property does not change depending on the part, but in the case of the combination body, the cushioning property can be finely adjusted partially by changing the material, hardness, thickness, etc. of the thin plate-like body 31. Become.

For example, when a hard material such as plastic is used as the material of the thin plate-like body 31, the concentration of stress applied to the surface of the cushion pad 4 can be reduced and partial deformation can be prevented. However, if a soft material such as urethane foam having a spring multiplier softer than that of the elastic body 6 is used, the sinking of the seat cushion pad 4 in contact with the part becomes deep, and the amount of sinking may vary depending on the part. As a result, the posture of the user when sitting can be made comfortable.

The invention of the seat cushion 2 according to claim 8 has the same effect as that of the invention according to any one of claims 1 to 7, and also makes the fit feel to the sensitive buttocks in the body, There is an effect of increasing stability.

The invention of the seat cushion 2 according to the ninth aspect has the same effect as the invention according to any one of the first to eighth aspects, and since the seat cushion pad 4 has conventionally been a flexible urethane foam, Although the seat cushion pad 4 of the present invention is hard, the skin 9 is covered with at least the surface of the seat cushion pad 4 so that the seat cushion pad 4 can be It can be locked by the locking member 32 attached to the cloth-like body 33 sewed in a form extended to the skin 9 on the back surface. As a result, the wire that has been inserted into the seat cushion pad 4 in the related art becomes unnecessary, and the weight reduction can be promoted.

It is a general | schematic perspective view of a sheet | seat. It is a general | schematic perspective view of a seat cushion (with skin). FIG. 6 is a cross-sectional view of the seat cushion of the form A when there is no load according to the present invention and a form cushion when there is no load (without skin), and is a cross-sectional explanatory view when there is no load. FIG. 4 is a schematic cross-sectional view taken along the line XX of the seat cushion shown in FIG. 3 when a load is applied and the seat cushion pad comes into contact with the seat cushion frame. FIG. 4 is an XX cross-sectional view of the seat cushion shown in FIG. 3, and is a schematic cross-sectional view when a load is applied and the seat cushion pad is being bent and deformed. FIG. 6 is a sectional view taken along line XX of the first seat cushion (without skin) of the form A when there is no load and the form C when there is no load. FIG. 7 is a sectional view taken along line XX of the seat cushion shown in FIG. FIG. 5 is a cross-sectional view taken along line XX of the seat cushion (with no skin) in a form in which the elastic body generates an upward reaction force due to elastic extension and the seat cushion pad and the side support portion are separated. FIG. 9 is a sectional view taken along the line XX of the seat cushion shown in FIG. 8 and is a schematic sectional view when a load is applied and the seat cushion pad is lowered. FIG. 9 is a sectional view taken along the line XX of the seat cushion shown in FIG. 8 when a load is applied and the seat cushion pad comes into contact with the seat cushion frame. It is a figure which shows the form which an elastic body produces an upward reaction force by elastic reduction. It is a perspective view of the seat cushion except the skin. FIG. 6 is a cross-sectional view when the bottom surface of the seat cushion pad is planar in the Y1-Y1 cross-sectional view. FIG. 6 is a cross-sectional view taken along the line Y1-Y1, in which an elastic body that generates an upward reaction force is provided by elastic reduction, and a rib in the left-right direction is formed on the bottom surface of the seat cushion pad. FIG. 6 is a cross-sectional view of the Y1-Y1 cross-sectional view in which left and right ribs are formed on the bottom surface of the seat cushion pad when the elastic body is changed to an elastic body that generates an upward reaction force by elastic extension. It is the perspective view which looked at the collar part periphery of the seat cushion pad of FIG. 15 from the bottom face side. It is the perspective view which looked at the form which made the circumference of a collar part of a seat cushion pad into a plane form from the bottom side of a seat cushion pad. FIG. 4 is a cross-sectional view of a seat cushion (without a skin) having a flat shape around the heel portion of the seat cushion pad, where (a) is an XX cross-sectional view and (b) is a Y1-Y1 cross-sectional view. FIG. 6 is a cross-sectional view of a seat cushion (without a skin) in which a thin plate-like body having rigidity is interposed between the bottom surface of the seat cushion pad and an elastic body, (a) is an XX cross-sectional view, and (b) is a cross-sectional view. It is Y1-Y1 sectional drawing. FIG. 4 is an explanatory view of a seat cushion (without a skin) in which a recess is formed on the surface of the seat cushion pad so as to conform to the outer shape of the user's buttocks, (a) is a perspective view, and (b) is Y2-Y2 around the buttocks It is sectional drawing. FIG. 10 is an XX cross-sectional view showing a form in which the skin covering the surface of the seat cushion pad is locked by a locking member sewn to the left and right ends of the skin on the bottom side of the seat cushion pad. It is the perspective view which looked at the form which latched the skin which coat | covered the surface of the seat cushion pad with the locking member which sewn the left and right ends of the skin on the bottom face side of the seat cushion pad on the left and right ends of the skin. FIG. 6 is a cross-sectional view taken along the line XX of a seat cushion (without a skin) provided with an insert on the seat cushion frame, and is a cross-sectional explanatory view when no load is applied. FIG. 5 is a cross-sectional view taken along the line XX of a seat cushion (without a skin) provided with an elastic contact body on a seat cushion frame, and is a cross-sectional explanatory view when no load is applied. It is explanatory drawing of a deformation | transformation of the seat cushion pad in the XX cross section in the case of the form which does not use an elastic body, Comprising: (a) showed the state at the time of no load, (b) showed the state at the time of load loading FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional explanatory drawing of the seat cushion pad which has the form where the form of the boundary surface of a seat cushion pad and a side support part was diagonally provided, Comprising: (a) is a figure which shows the time of no load, (b) is the time of load. FIG. It is a longitudinal cross-sectional explanatory drawing of the seat cushion pad which has the form where the form of the boundary surface of a seat cushion pad and a side support part was substantially suspended, Comprising: (a) is a figure which shows the time of no load, (b) is the time of load FIG. XX sectional view of the seat cushion (without skin), explanation of the form in which protrusions are provided below the ribs, the left and right end sides are cantilevered, and the seating surface is curved along the buttock FIG. It is explanatory drawing when a user sits on the seat cushion (with no skin) of FIG. 28, (a) is explanatory drawing when a buttock contacts the front-end | tip of the curved part of a seat cushion pad, (b) is It is explanatory drawing of a curved shape part when a user is seated. It is explanatory drawing of the form which mounted the soft body above the seat cushion (no skin) of FIG. It is a figure explaining the relationship between the load and displacement of a seat cushion pad when a load is applied by the user, where (a) is a form A when there is no load, and (c) is a form C when loaded. When there is no load, the configuration is A, and when the load is configuration C, and the elastic contact body 7 is provided on the seat cushion frame, when (c) is the configuration of FIGS. 6 and 7, (d) is the seat cushion. It is a figure which shows the case where a pad is not supported by an elastic body but is supported by a seat cushion frame. It is a comparison figure of the bending test by JISK7221-2 with a foam and a non-foam.

Hereinafter, embodiments of the seat cushion 2 according to the present invention will be described. The seat cushion 2 corresponds to the seating surface of the seat 1 shown in FIG. 1, and has a form as shown in FIG. 2, for example.

The seat cushion 2 according to the present invention includes a seat cushion pad 4 that is provided with a seating surface with which a user's lower thigh and buttocks abut, is made of a synthetic resin foam, and is bent and deformed downward, and the seat cushion pad 4 below the seat cushion pad 4. A space 10 that enables bending deformation of the seat cushion pad 4, a seat cushion frame 5 that is spaced apart below the seat cushion pad 4, and an elastic body 6 that supports the seat cushion pad 4. The seat cushion pad 4 is not supported by the seat cushion frame 5 but is supported by the elastic body 6 when there is no load. Here, as a form of the elastic body 6 that supports the seat cushion pad 4, a form in which the seat cushion pad 4 is supported by the elastic body 6 from below, or the seat cushion pad 4 is suspended by the elastic body 6 from above. There is a form to set. Further, the form of the seat cushion frame 5 that is spaced apart below the seat cushion pad 4 includes a form in which the seat cushion frame 5 is disposed only below the seat cushion pad 4, or the seat cushion frame 5 A configuration in which the seat cushion pad 4 is disposed downward from the side of the seat cushion pad 4 is also included.

As a form of the seat cushion 2, for example, when no load is applied, the seat cushion pad 4 is supported by the elastic body 6 without contacting the seat cushion frame 5, and when loaded by the user, the seat cushion pad 4 is supported. Causes a concave deformation according to the magnitude of the load applied to each part of the seat cushion pad 4, and the downward force of the load W and the upward reaction of the elastic body 6 caused by the elastic deformation of the elastic body 6. The force is balanced, or the downward force due to the load W, the upward reaction force of the elastic body 6 caused by the elastic deformation of the elastic body 6, and the left and right sides of the seat cushion pad 4 by the seat cushion frame 5 There is a form in which the upward reaction force generated by bending deformation downward in the end support state is balanced.

The synthetic resin foam is a synthetic resin foam having a bending deflection amount of 20 mm or more measured according to the method described in JIS K7221-2: 2006 and a load of 2 to 100 N when 20 mm is bent.

When a hard synthetic resin foam that is stiffer than urethane foam is used for the seat cushion pad 4, the user feels a comfortable seating feeling when seated on the seat cushion pad 4; Further, the present invention has been conceived by avoiding the seat cushion pad 4 from deforming out of the elastic region and being unable to recover and accumulating deformation.

In the seat cushion 2 of the present invention, the back surface of the seat cushion pad 4 is supported by the elastic body 6 as shown in FIGS. Preferably, the seat cushion pad 4 is supported by an elastic body 6 that is supported in an upward biased state.

Further, as an unloaded form, there is a form A in which the seat cushion pad 4 of the seat cushion pad 4 is separated from the seat cushion frame 5 in the vertical direction.

And as a form at the time of the load by the user, the seat cushion pad 4 is always separated from the seat cushion frame 5 in the vertical direction, or the seat cushion pad 4 is the seat cushion frame 5 at the beginning of the seating of the user. There is a form C consisting of a first stage separated in the vertical direction and a second stage in which the seat cushion pad 4 comes into contact with the seat cushion frame 5 in the vertical direction by the sinking of the seat cushion pad 4 thereafter.

The elastic deformation of the elastic body 6 includes elastic expansion and contraction, and the elastic body 6 is brought into contact with the back side of a seat cushion pad 4 made of a synthetic resin foam as shown in FIG. The seat cushion pad 4 can be moved up and down by elastic extension like the S spring shown in FIGS. 10 and 15 or by elastic reduction like the coil spring shown in FIGS. 11, 13 and 14. As shown in FIG. 3, the attachment position of the elastic body 6 to the seat cushion pad 4 is the back side of the seat cushion pad 4, the left and right sides of the seat cushion pad 4 (not shown), and the left and right ends of the seat cushion pad 4. Below (not shown).

In any form or mounting position, when the user sits down, the seat cushion pad 4 is caused to descend with a certain reaction force necessary to give the impression that the seat cushion pad 4 is flexible. In addition, the seat cushion pad 4 may be in any form or mounting position that does not cause bending deformation beyond its elastic range.

Next, the elastic body 6 may be made of a metal leaf spring, a metal linear spring, an S spring, a coil spring, rubber, a resin body having elasticity, or the like having a sufficient restoring force.

First, as a comparative example of the present invention, the elastic body 6 is not provided below the seat cushion pad 4, and the seat cushion pad 4 is supported by the seat cushion frame 5 so as to be supported at both ends. The form which has property is demonstrated.

As shown in FIG. 25 (a), when the seat cushion pad 4 is bent and deformed as shown in FIG. As shown in the figure, the amount of displacement of the seat cushion pad 4 that is bent downward due to the bending deformation of the seat cushion pad 4 changes as shown by the line s in proportion to the weight of the load. You can feel sex.

However, the user tends to feel higher cushioning when he / she feels the seat cushion pad 4 sinking at the moment of sitting, whereas the user does not easily cause the seat cushion pad 4 to sink. In addition, since the synthetic resin foam tends to have a narrow elastic region, there is a concern that when a heavy user sits many times, the elastic resin deforms out of the elastic region and cannot be recovered, and the deformation accumulates.

Therefore, when a heavy weight user is seated many times, the seat cushion pad 4 made of a synthetic resin foam may be deformed out of the elastic region and cannot be recovered, and the seat cushion pad 4 may be accumulated. The elastic body 6 was disposed so as to disperse the load on the. This corresponds to Form A when there is no load, and Forms B and C when loaded.

Next, an elastic body 6 that supports the seat cushion pad 4 in an upward biased state is disposed in order to make the user feel the sink of the seat cushion pad 4 at the moment when the user is seated. The pad 4 was separated from the seat cushion frame 5 in the vertical direction.

First, the case where the structure is changed from the form A when no load is applied to the form B when loaded is described. In order to allow the user to feel the sinking at the moment when the user is seated, the user is maintained in a state of being separated from the seat cushion frame 5 in the vertical direction by the elastic body 6 supported by the seat cushion pad 4 when no load is applied. At the beginning of the load due to the load, the seat cushion pad 4 does not come into contact with the seat cushion frame 5 with respect to the downward force due to the load, and is lowered by the elastic extension or contraction of the elastic body 6. It was set as the form which produces the reaction force of a direction.

By adopting the above configuration, the user can feel a comfortable cushioning that sinks at the moment of sitting.

Therefore, the form of change of the seat cushion pad 4 when the user is seated is the downward force due to the load of the user and the elastic extension of the elastic body 6 without the seat cushion pad 4 abutting against the seat cushion frame 5. Or there exists a form which balances with the upward reaction force of the elastic body 6 which descend | falls by elastic deformations, such as elastic reduction.

In the case of this configuration, as shown in FIG. 6, when no load is applied, the seat cushion pad 4 is maintained in a state where it does not come into contact with the seat cushion frame 5 by the elastic body 6 supported in the upward biased state. When the person's load is applied, as shown in FIG. 7, the seat cushion pad 4 starts to sink, and the seat cushion pad 4 is seen in a plan view according to the body part such as the posture of the user and the rib part. Depending on the magnitude of the load that is different for each part captured in step S2, the seat cushion pad 4 is depressed until it reaches a reaction force that balances with the downward force due to the load of the user while deforming indented. FIG. 7 shows that the position “a” on the surface of the seat cushion pad 4 at the time of no load is reduced to a subtraction amount “b”.

Further, as shown in FIG. 31 (c), the displacement amount that the seat cushion pad 4 sinks downward due to elastic deformation such as elastic expansion or contraction of the elastic body 6 is indicated by a line r in proportion to the weight of the load. Change like this. By this change, the user can feel a high cushioning property by feeling the sinking of the seating surface from the moment of sitting until the sinking stops.

Next, a description will be given of the case of a structure that changes from form A at no load to form C at the time of load. In this form, after the seat cushion pad 4 descends due to the downward force caused by the load of the user and the elastic deformation such as elastic expansion or contraction of the elastic body 6 and comes into contact with the upper part of the seat cushion frame 5 This is a form in which the upward reaction force generated by bending and deforming the seat cushion pad 4 downward in a state where both ends are supported and the upward reaction force of the elastic body 6 are balanced.

In this case, as shown in FIG. 3, when no load is applied, the seat cushion pad 4 is maintained in a state where it does not contact the seat cushion frame 5 by the elastic body 6 supported in the upward biased state. When the person's load is applied, as shown in FIG. 4, the seat cushion pad 4 starts to sink, and sinks while being deformed, and comes into contact with the seat cushion frame 5, and then, as shown in FIG. As shown, the seat cushion pad 4 has a both-end support structure with the left and right seat cushion frames 5 as fulcrums, and the seat cushion pad 4 is bent and deformed with both ends as fulcrums.

Further, as shown in FIG. 23, this form includes a form in which an insert 8 such as a nonwoven fabric is sandwiched between the seat cushion frame 5 and the seat cushion pad 4 in order to prevent rubbing noise. . The seat cushion frame 5 and the seat cushion pad 4 are not in direct contact with each other, but since the insert 8 does not have elasticity, the seat cushion pad 4 abuts against the left and right inserts 8 at the same time. The seat cushion pad 4 has a both-end support structure with the left and right seat cushion frames 5 as fulcrums, and the seat cushion pad 4 bends and deforms with both ends as fulcrums.

As shown in FIG. 31 (a), the amount of displacement that the seat cushion pad 4 sinks downward due to elastic deformation such as elastic expansion or contraction of the elastic body 6 is a transition of the line m in proportion to the weight of the load. From the time point k when the seat cushion pad 4 comes into contact with the seat cushion frame 5, the change as shown by the line n is caused by the bending deformation of the both ends supporting beam of the seat cushion pad 4. By this change, the user can feel a comfortable cushioning property that sinks mainly at the beginning of the seating, and thereafter can feel a comfortable cushioning property that feels like landing with a soft touch.

In the case of this form, as shown in FIG. 24, there is also a form in which the elastic contact body 7 is provided on the seat cushion frame 5. In the case of this configuration, when no load is applied, the seat cushion pad 4 is not in contact with the seat cushion frame 5 and the elastic contact body 7 by the elastic body 6 supported in the upward biased state as shown in FIG. When the user's load is applied, the seat cushion pad 4 starts to sink, and sinks while being deformed to be in contact with the elastic contact body 7 provided on the upper portion of the seat cushion frame 5. Thereafter, the elastic contact body 7 is compressed and deformed, and then the seat cushion pad 4 has a double-end support structure with the left and right seat cushion frames 5 as fulcrums, and the seat cushion pad 4 is bent and deformed with both ends as fulcrums. In the present invention, the phrase “abuts on the upper part of the seat cushion frame 5” refers to the case where the seat cushion pad 4 abuts on the seat cushion frame 5, or the elastic force of the upper part of the seat cushion frame 5. This includes the case of contacting the contact body 7 or the interposition 8.

The material of the elastic contact body 7 is sufficient when the seat cushion pad 4 descends and comes into contact and is subjected to a load and compresses and deforms within the elastic limit, and when the seat cushion pad 4 rises and separates and becomes unloaded. There are metal plate springs, metal linear springs, S springs, coil springs, rubbers, elastic resin bodies, etc. that have a good restoring force.

As shown in FIG. 31 (b), the amount of displacement that the seat cushion pad 4 sinks downward due to elastic deformation such as elastic expansion or contraction of the elastic body 6 is a transition of the line m in proportion to the weight of the load. From the time point k when the seat cushion pad 4 comes into contact with the upper elastic contact body 7 of the seat cushion frame 5 after the change as shown in FIG. After the compression of the elastic contact body 7, the change as shown by the line n is caused by the bending deformation of the both ends supporting beam of the seat cushion pad 4. Since the connection point between the line m and the line n is smoothly bent by the line q, the seat cushion 2 is sufficiently flexible when the user first descends the seating surface with a certain reaction force when sitting. After receiving the impression that there is, the displacement of the seat cushion pad 4 due to bending deformation is smoothly applied and the body is supported, so that a very comfortable seating feeling can be obtained.

In any of the structure from form A when no load is applied to form B when loaded and structure from form A when no load is applied to form C when loaded, the user's load is only the hard seat cushion pad 4 Since it is also applied to the elastic body 6, the load W applied to the seat cushion pad 4 can be reduced. Therefore, the seat cushion pad 4 which is hard and has a narrow elastic area is used in the elastic area regardless of the weight of the user's load. be able to.

Next, the height of the side support portion 21 is higher than the height of the seat cushion pad 4 as shown in FIG. 8, or the height of the side support portion 21 is substantially the same as the height of the seat cushion pad 4 as shown in FIG. There is a form. In the case where the height of the side support portion 21 is higher than the height of the seat cushion pad 4 as shown in FIG. 8, the seat cushion pad 4 and the side support portion 21 constituting the seat cushion pad 4 are seated at least. They are separated at the left and right ends of the seat cushion pad 4 with which the person's buttocks abut.

The separation form at the left and right end portions of the seat cushion pad 4 with which at least the seated user's buttocks abuts is, for example, the seat on which the user's buttocks that the seated user sits as shown in FIG. A form in which the left and right ends of the cushion pad 4 are separated, a form in which the front side is separated including the left and right ends of the seat cushion pad 4 with which the user's buttocks abuts the second separated form, and a third separated form. A form (not shown) in which the rear side is separated including the left and right end parts of the seat cushion pad 4 with which the seated user's buttocks abuts, and the fourth separation form is the seat cushion pad 4 and the side support part 21 in all front and rear directions. There is a form (not shown) that is separated over.

And the form of the front view of the boundary surface 23 between the seat cushion pad 4 and the side support portion 21 is inclined so as to go outward in the left-right direction as it goes downward from the upper ends of the left and right end portions of the seat cushion pad 4. There is also a configuration in which the seat cushion pad 4 is bent.

In the case where the height of the side support portion 21 is higher than the height of the seat cushion pad 4, in the case where the seat cushion pad 4 and the side support portion 21 are integrally molded, the effect of reducing the manufacturing cost by integral molding However, the seat cushion pad 4 is bent and deformed like a both-ends support beam with the left and right end portions as fulcrums by the seating of the user, and the central portion in the left and right direction is greatly recessed. As a result, the upper side of the side support portion 21 provided on the left and right end portions of the seat cushion pad 4 is inclined toward the center in the left-right direction, and the upper side of the side support portion 21 comes into contact with the user and the user feels pressure. There was a problem of feeling.

Therefore, as shown in FIG. 8, the seat cushion pad 4 and the side support portion 21 are separated from each other. FIG. 8 shows a state when no load is applied. In this state, the seat cushion pad 4 and the side support portion 21 are in contact with each other at the boundary surface 23. Thereafter, as shown in FIG. 9, when a user's load W is applied, the seat cushion pad 4 is slightly spaced from the left and right side support portions 21 and the boundary surface 23, and the seat cushion pad 4 and the left and right side support portions 21 are separated. Begin to. Further, even if the seat cushion pad 4 is lowered and bent downward, the gap of the boundary surface 23 is expanded as shown in FIG. 10 and the side support portion 21 is not affected left and right. As a result, even if the seat cushion pad 4 is lowered and bent downward, a change due to the bending deformation of the seat cushion pad 4 hardly affects the side support portion 21, and the upper side of the side support portion 21 is closer to the center in the left-right direction. This prevents the user from leaning and the user does not feel a sense of pressure when seated. Here, even if a gap occurs in the boundary surface 23, the seat cushion pad 4 and the side support portion 21 are covered with the skin 9, so that the user does not feel uncomfortable.

In the case of the first to third separation forms other than the fourth separation form in which the seat cushion pad 4 and the side support part 21 are separated across the entire front-rear direction, the range other than the left and right sides of the user's buttocks is Since there is little bending deformation, the inclination of the side support portion 21 closer to the center is reduced, and the effect that the user does not feel much pressure when seated is achieved.

Next, the form of the skin 9 with respect to the form of the seat cushion pad 4 and the side support part 21 will be described. When the seat cushion pad 4 is integrally formed with the side support portion 21, the seat cushion pad 4 is hard, so that the longitudinal cross-sectional shape of the skin 9 is substantially concave due to the side support portion 21 and the seat cushion pad 4. There is a problem that it is difficult to stretch the seat cushion pad 4 in close contact with the surface of the seat cushion pad 4, and there is a problem that the outer skin 9 is likely to be wrinkled in appearance.

Therefore, as shown in FIG. 8, in the case where the seat cushion pad 4 and the side support portion 21 are separated and the side support portion 21 is disposed on the inclined boundary surface 23, the skin 9 is attached to the seat cushion pad 4 and the side support. It becomes possible to draw in between the part 21 and it becomes easy to make the outer skin 9 adhere to the surface of the seat cushion pad 4 and to stretch it. Then, the skin 9 can be easily covered and stretched on the side support portion 21 after being stretched on the seat cushion pad 4, and there is an effect that wrinkles are hardly generated on the appearance of the stretched skin 9.

As shown in FIG. 27, the form of the boundary surface 23 between the seat cushion pad 4 and the side support portion 21 hangs downward from the left and right end portions of the seat cushion pad 4 in the case of no load. Although there are points t on the left and right ends of the substantially horizontal line u indicating the upper surface of the seat cushion pad 4 when there is no load, the seat cushion pad 4 is loaded when the user is seated as shown in FIG. The center portion in the left-right direction of the seat cushion pad 4 that is bent downward is spaced from the substantially horizontal line u-line when no load is applied in the up-down direction, but the point t that is the left-right end portion of the seat cushion pad 4 is drooping. Since the provided columnar body has rigidity and is not easily deformed, it exists on a substantially horizontal line u line. As a result, a large reaction force corresponding to the load is generated at the point t. Therefore, the user receives an impression that the left and right end portions of the seat cushion pad 4 are hard and feels uncomfortable at a specific part when sitting. was there.

Therefore, as shown in FIG. 8 or FIG. 26, the form of the boundary surface 23 between the seat cushion pad 4 and the side support portion 21 is inclined outwardly from the left and right ends of the seat cushion pad 4, When the seat cushion pad 4 is bent with respect to the seat cushion pad 4, as shown in FIG. 26 (a), in the case of no load, the left and right on the substantially horizontal line f indicating the upper surface of the seat cushion pad 4 at the time of no load. Although there is a point j at the end, as shown in FIG. 26 (b), the seat cushion pad 4 bends and deforms downward when the user is seated, and the center portion in the left-right direction of the seat cushion pad 4 is unloaded. A vertical gap occurs between the dotted line indicating the substantially horizontal line f line and the point j located at the left and right ends also moves downward from the dotted line indicating the substantially horizontal line f line when there is no load. So that the, by further bending deformation occurs in the columnar body is obliquely disposed, the reaction force in the j proximity points are right and left end portions of the seat cushion pad 4 is greatly reduced.

Accordingly, the reaction force generated in the seat cushion pad 4 can be equalized over a wide range of the seat cushion pad 4, so that the user is less likely to feel the reaction force in the vicinity of the left and right ends when seated, and the entire area of the seat cushion pad 4 is reduced. There is an effect of feeling the same sitting comfort.

Next, the thickness of the seat cushion pad 4 has a substantially uniform thickness as shown in FIG. 13, and protrusions such as ribs 30 for the purpose of reinforcement as shown in FIGS. There is a concave-convex shape provided with the. In order to further reduce the weight of the seat cushion pad 4, the ribs 30 and the like are reinforced in order to ensure the strength to withstand repeated use while reducing the thickness of the seat cushion pad 4. Although it has the effect of reducing the weight, the user's buttocks slightly feels that the seat cushion pad 4 has a different thickness.

Therefore, as shown in FIGS. 17 and 18, ribs 30 and the like that protrude downward to come into contact with the elastic body 6 are provided on the bottom surface of the seat cushion pad 4 except for a range in which the user's rib comes into contact in plan view. Although the protrusions are provided, the protrusions such as the ribs 30 are not provided on the surface of the bottom surface of the seat cushion pad 4 corresponding to the range in which the user's ribs abut in the plan view of the seat cushion pad 4.

The user's body is sensitive to touching parts of the buttocks and requires high cushioning. In the sitting position, the user's load is greatly applied to the buttocks contact area 25 of the seat cushion pad 4, and the hard part of the collarbone is the buttocks. It contacts the contact range 25. For this reason, the seat cushion pad 4 is thinned in order to easily cause bending deformation of the seat cushion pad 4 and enhance cushioning properties. However, in order to compensate for insufficient rigidity due to the thinning, protrusions such as ribs 30 are provided. Is provided. At that time, if the heel part is sensitive to the presence of a part having a different thickness of the seat cushion pad 4, the seating comfort is lowered, so that the thickness of the buttock contact area 25 of the seat cushion pad 4 is made uniform. Thereby, comfortable cushioning properties can be felt without the buttocks feeling uncomfortable.

The shape of the rib 30 is not a long rod-like body, but by providing a large number of ribs 30 in an uneven shape as shown in FIG. 23, the seat cushion pad 4 is easily bent and deformed by a load even if the rib 30 is provided. There is an effect.

Next, as shown in FIG. 28, in a plan view, a protrusion such as a rib 30 projecting downward to come into contact with the elastic body 6 on the bottom surface of the seat cushion pad 4 in a range where the user's rib comes into contact. There is also a form in which the left and right sides of the range excluding the range where the ribs contact are provided as a cantilever support configuration, and the seating surface has a shape in which the left and right sides are curved upward in a front view.

In the case of this form, when the user is seated, the left and right end portions of the seat cushion pad 4 are bent to the center side from the form shown in FIG. 29A to the form shown in FIG. Therefore, the user feels as if the body is wrapped and can obtain a comfortable seating feeling.

Further, as shown in FIG. 30, a soft cushion material such as urethane foam is placed on the seat cushion pad 4 of the synthetic resin foam. Since the skin 9 on the surface side of the seat cushion pad 4 is stretched by this cushion material, the user does not notice that a recess is formed on the surface of the seat cushion pad 4, and the cushioning property is improved. Play.

Next, as shown in FIG. 20, the outer shape of the vicinity of the rib is conformed so that the vicinity of the user's sciatal fits perfectly on the surface of the seat cushion pad 4 corresponding to the range where the sciatic of the user contacts in plan view. Thus, the recess 26 is formed.

In the user's body, the buttocks are sensitive to touching objects, and in the sitting position, the user's load is greatly applied to the seat cushion pad 4 in the range where the ribs abut, and the ribs on the surface of the seat cushion pad 4 where the ischia abuts By forming the concave portion 26 along the outer shape in the vicinity, the buttocks are seated firmly and stably on the seat cushion pad 4, and the seating feeling is enhanced.

Next, as shown in FIG. 19, a thin plate-like body 31 is interposed between the bottom surface of the seat cushion pad 4 and the elastic body 6. The material, hardness, thickness, and the like of the thin plate-like body 31 can be changed. A soft material such as urethane foam corresponds to a soft material, and a press felt in consideration of weight reduction as a hard material. Light and hard materials such as non-ferrous metals such as aluminum and synthetic resins such as plastic are applicable.

When a hard material such as plastic is used, the stress concentration on the surface of the cushion pad 4 can be reduced and partial deformation can be prevented, but the spring is softer than the elastic body 6. When a soft material such as urethane foam having a multiplier is used, the seat cushion pad 4 that contacts the part becomes deeper, and the amount of sinking can be made different depending on the part. The posture can be made comfortable.

Further, since the seat cushion pad 4 is manufactured from the same material at the portion having the seating surface, the seat cushion pad 4 alone cannot incorporate a measure for reducing stress concentration depending on the portion of the seating surface or make the cushioning property different depending on the portion. However, by selecting whether the thin plate member 31 is made of a soft material or a hard material depending on the part of the seating surface, it is possible to take measures against stress concentration and adjust the sinking amount depending on the part of the seating surface.

Next, as shown in FIGS. 21 and 22, the skin 9 that covers the seat cushion pad 4 and the side support portion 21 or covers the seat cushion pad 4 is arranged at the left and right ends of the skin 9 on the bottom surface side of the seat cushion pad 4. Is locked by a locking member 32 attached to the left and right ends of the skin 9 or a locking member 32 attached to a cloth-like body 33 sewn to the left and right ends of the skin 9. The sewing part of the skin 9 and the cloth-like body 33 may be a part where the skin 9 can cover at least the seat cushion pad 4.

Since the seat cushion pad 4 is a synthetic resin foam and has rigidity, the skin that covers the seat cushion pad 4 without attaching the terminal of the skin 9 to the wire inserted into the seat cushion pad 4 as in the prior art. 9 was able to be fastened with the ends of the cloth-like body 33 sewed in a form extending from the left and right end portions. This method is not limited to the seat cushion 2 and can be applied to the attachment of the skin 9 of the seat back as long as the seat back pad is manufactured from a synthetic resin foam.

This method of attaching the skin 9 makes it possible to attach the skin 9 to the seat cushion pad 4 before the seat cushion frame 5 and the seat cushion pad 4 are combined.

Next, the synthetic resin foam will be described. The synthetic resin foam in the present invention is flexible, can be bent and deformed, and has excellent restoration properties. The method described in JIS K7221-2: 2006 (23 ° C. ± 2 ° C., relative humidity 50 ± 5% A test piece having a length of 350 mm, a width of 100 mm, and a thickness of 25 mm, with the skin removed, is applied with a load of up to 90 mm at a fulcrum distance of 300 mm and a test speed of 20 ± 1 mm / min, and a load deflection curve is recorded. A synthetic resin foam molded body having a bending deflection of 20 mm or more measured according to the above and a load of 2 to 100 N at the time of 20 mm deflection. A synthetic resin foam molded article that causes fracture when the bending deflection is less than 20 mm is not suitable from the viewpoint of durability. When the cross section of the support body 3 required for supporting the pressing by the body becomes very large and the load at the time of 20 mm bending is more than 100 N, it becomes difficult to generate a preferable bending amount, and a preferable design is difficult. Specifically, it refers to foamed polypropylene, foamed polyethylene, other polyolefin resin foams, modified polystyrene resin foams, and the like. Among the foams, an in-mold molded body of resin foam particles is preferable from the viewpoint of shape flexibility (designability) considering a fit.

The polyolefin resin constituting the expanded particles used in the present invention is a polyolefin resin having an olefin component unit as a main component, specifically, a polypropylene resin, a polyethylene resin, and a mixture of two or more thereof. Is mentioned. The above-mentioned “main component” means that the olefin component unit is contained in the polyolefin resin in an amount of 50% by weight or more, and the content thereof is preferably 75% by weight or more, more preferably 85% by weight. % Or more, more preferably 90% by weight or more.

Examples of the polypropylene-based resin include resins having a propylene component unit of 50% by weight or more, and examples thereof include a propylene homopolymer or a copolymer with another olefin copolymerizable with propylene. Examples of other olefins copolymerizable with propylene include ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1 Examples thereof include α-olefins having 4 to 10 carbon atoms such as -heptene and 3-methyl-1-hexene. The copolymer may be a random copolymer or a block copolymer, and may be not only a binary copolymer but also a ternary copolymer. The other olefin copolymerizable with propylene in the copolymer is preferably contained in a proportion of 25% by weight or less, particularly 15% by weight or less, and the lower limit is 0.3% by weight. Preferably there is. These polypropylene resins can be used alone or in combination of two or more. Polypropylene resin has a tensile modulus (E) specified in JIS K7161: 1994 (test piece: JIS K-7162 (1994), test piece 1A type (direct molding by injection molding), test speed: 1 mm / min)) A resin foam obtained by foaming a base resin having a value of 600 MPa or more is preferable.

Examples of the polyethylene resin include resins having an ethylene component unit of 50% by weight or more, such as high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer. Polymers, ethylene-propylene-butene 1 copolymer, ethylene-butene 1 copolymer, ethylene-hexene 1 copolymer, ethylene-4 methylpentene 1 copolymer, ethylene-octene 1 copolymer, and the like. The mixture of 2 or more types is mentioned.

Then, in the specific selection of the synthetic resin foam, both ends of a rod-shaped test piece having a length of about 400 mm are supported, the center is pushed back and forth by 25 mm and held for 30 minutes, and then the load is released, and then the deformation from the sample is changed. Residual strain measured after the center portion of the sample that supported both ends was repeatedly pressed down and deformed in accordance with tests performed on materials with 90% or more recovery or conventional urethane foam seat cushions. A material in which is less than a predetermined amount is desirable. The predetermined number of times or the predetermined amount conforms to a specification arbitrarily determined when each vehicle manufacturer selects a conventional material.

Such materials satisfying, for example of expanded polypropylene density ^{0.06g / cm 3 ~ 0.015g / cm} 3, more preferably a density ^{0.035g / cm 3 ~ 0.015g / cm} 3, or of foamed polyethylene A density of 0.08 g / cm ³ to 0.03 g / cm ³ is preferable. Such a material is prepared by the method described in JIS K7221-2: 2006 (a test piece having a length of 350 mm, a width of 100 mm, and a thickness of 25 mm with the skin removed in an atmosphere of 23 ° C. ± 2 ° C. and a relative humidity of 50 ± 5%. In a test conducted in accordance with a distance between fulcrums of 300 mm, a test speed of 20 ± 1 mm / min up to a maximum of 90 mm, and a load deflection curve is recorded. However, the flexible urethane foam that has been conventionally used is not suitable as a material constituting the seat cushion of the present invention because the flexural rigidity is generally inferior to 0.46 N.

Below, the creep property and bending rigidity when a synthetic resin foam is used will be described. First, in order to evaluate the creep property, compression set according to JIS K 6767: 1999 was measured. A test piece having a length of 50 mm, a width of 50 mm, and a thickness of 25 mm is compressed into a 25% distorted state and left at a temperature of 23 ° C. ± 2 ° C. for 22 hours. The thickness is measured 24 hours after the end of compression. The compression set was determined by compression set (%) = (test specimen original thickness (mm) −thickness 24 mm after completion of compression (mm)) ÷ test specimen original thickness (mm) × 100.

As a result of the test, the compression set of the 45-fold polypropylene foam particle molded body was 11%. On the other hand, the compression set of the polyurethane foam by the same measuring method is 2% or less. This is because conventional urethane foam, which is generally used as a cushioning material for seat cushions, exhibits cushioning properties by compression deformation. If it is simply replaced with a synthetic resin foam, compression set is generated, and the original cushion It is shown that it is difficult to maintain the product and the commercial value is lowered.

On the other hand, the inventor is comparable to the urethane foam that has been used in the past when bending and recoverability of a synthetic resin foam that is capable of bending deformation and has excellent resilience is used as a cushioning material. It was conceived that the creep resistance is higher or higher.

When the synthetic resin foam is used as the seat cushion pad 4, the creep resistance exceeds that of the urethane foam. When the center part is pushed down and bending deformation occurs, each part of the member is pulled, compressed, sheared, etc. The member is deformed, but the degree of each deformation is less than the amount of direct deformation in the case of using a cushion material by simply compressing the member as in the past, and the elasticity that does not impair the recoverability Because it stops in the region.

Next, FIG. 32 shows a sample made of non-foamed resin plate (thickness 1 mm) made of an equivalent resin and a sample made of 45-fold foamed polypropylene foam (thickness 45 mm). ) JIS K7221-2: 2006 (length of 350 mm, width 25 mm, sample weight equivalent, thickness with the skin removed under an atmosphere of 23 ° C. ± 2 ° C. and relative humidity 50 ± 5%. It is a load-displacement diagram in the case where both ends are supported according to 300 mm and a load is applied up to 90 mm at a test speed of 20 ± 1 mm / min, and a load deflection curve is recorded, and this central part is pushed down. The width was kept constant at 25 mm, and the thickness was adjusted so that the sample weight was equal. The case of a non-foamed resin plate is represented by a load-displacement amount diagram M, and the case of a sample made of a foamed polypropylene 45-fold product is represented by a load-displacement diagram H.

From FIG. 32, it is shown that although the weight of the sample is the same, bending rigidity is greatly increased by using a foam. Conventionally, it has not been common to bend a foam and use it as a cushioning material. However, by using a foam, the weight of components required to obtain equivalent bending rigidity can be reduced, that is, the seat cushion 2. It is shown that the weight can be reduced.

DESCRIPTION OF SYMBOLS 1 Seat 2 Seat cushion 3 Seat back 4 Seat cushion pad 5 Seat cushion frame 6 Elastic body 7 Elastic contact body 8 Insert 9 Skin 10 Space part 21 Side support part 23 Boundary surface 25 Gutter contact range 26 Recess 30 Rib 31 Thin plate body 32 latching member 33 cloth-like body 40 soft layer 50 buttocks

Claims

A seat cushion pad made of a synthetic resin foam that bends and deforms downward, and a space that allows the seat cushion pad to be bent and deformed below the seat cushion pad. Part, a seat cushion frame spaced apart below the seat cushion pad, and an elastic body that supports the seat cushion pad, and the seat cushion pad is not supported by the seat cushion frame when no load is applied, A seat cushion characterized by being supported by an elastic body.
2. The seat cushion according to claim 1, wherein side support portions are provided in a form separated from the seat cushion pad on the left and right end sides of the seat cushion pad with which the collar portion abuts.
The synthetic resin foam is a synthetic resin foam having a bending deflection amount measured in accordance with a method described in JIS K7221-2: 2006 of 20 mm or more and a load at the time of 20 mm deflection of 2 to 100 N. The seat cushion according to claim 1 or 2.
The form of the front view of the boundary surface of the said seat cushion pad and the said side support part consists of a form inclined so that it might go outward as it goes below from an upper end, It is characterized by the above-mentioned. Seat cushion.
In a plan view, a protrusion such as a rib that protrudes downward so as to contact the elastic body is provided on the bottom surface of the seat cushion pad except for a range where the user's rib contacts. The seat cushion according to any one of claims 1 to 4.
In plan view, the center portion of the seat cushion pad is supported by an elastic body, the front and rear ends and / or the left and right ends of the seat cushion pad are cantilevered, and the front and rear ends and / or the left and right ends of the seat cushion pad face upward The seat cushion according to any one of claims 1 to 4, wherein the seat cushion has a curved shape.
The seat cushion according to any one of claims 1 to 6, wherein a thin plate-like body is interposed between a bottom surface of the seat cushion pad and the elastic body.
The seat cushion according to any one of claims 1 to 7, wherein a concave portion is formed on a surface of the seat cushion pad so as to follow a hip portion when the user is seated.
Covering the seat cushion pad and the side support part, or the skin covering the seat cushion pad is sewn on the bottom surface side of the seat cushion pad, the locking member attached to the left and right ends of the skin, or the left and right ends of the skin The seat cushion according to any one of claims 1 to 8, wherein the seat cushion is locked by a locking member attached to the cloth-like body.