JP5570056B2 - Seat structure - Google Patents

Description

  The present invention relates to a seat structure, and more particularly, to a seat structure that can be used as a seat for a transportation device such as an automobile, an aircraft, and a train, and can also be used as an office chair, a furniture chair, a sofa, or the like.

  In order to reduce the weight of the seat structure, the present applicant has proposed various seat structures using a tension structure provided with a three-dimensional solid knitted fabric or a two-dimensional net material on the cushion frame or the back frame. . In Patent Documents 1 to 3, a base net is stretched to a seat cushion portion via a torsion bar to give a predetermined cushion characteristic. In addition to a three-dimensional solid knitted fabric, a thin urethane material is used as a cushion material. Compared with the so-called `` placement structure '' type in which a conventional urethane material with a predetermined thickness is placed on a cushion pan, the vibration absorption characteristics and the shock absorption characteristics are improved while reducing the weight. Is. Further, in Patent Document 4, when a load exceeding a predetermined value is applied to the cushion material stretched on the back frame due to a rear-end collision or the like, the side frame falls down, thereby reducing the tension of the cushion material, and the impact is effective. It has a structure that can be attenuated automatically. According to this, a human body can be received and a shock can be attenuated with a simple configuration. In addition, there is an energy absorption effect due to the inward deformation of the side frame.

JP 2004-188164 A JP 2006-345902 A Japanese Patent Laid-Open No. 2006-345953 JP 2003-182427 A

  As described above, the seat structures of Patent Documents 1 to 4 are lightweight and excellent in vibration absorption characteristics and shock absorption characteristics, but the posture when the inertial force in the lateral direction acts during cornering or the like. Is supported mainly by the bulging portions on both sides of the seat cushion portion and the seat back portion. In order to enhance the support of the posture when the inertial force in the left-right direction is applied, it may be possible to increase the height by laminating urethane materials on the bulging portions on both sides, but if it is too high, the weight may increase. . There may also be a tight feeling. Therefore, it is desired that the supportability of the posture when the inertial force in the left-right direction is applied can be further improved while maintaining the characteristic of lightness regardless of whether the urethane material is laminated.

  On the other hand, although the seat structure of patent documents 1-4 contributes to weight reduction as mentioned above, the further weight reduction of a seat structure is calculated | required in recent years with the spread of a hybrid vehicle, an electric vehicle, etc. In order to reduce the weight, it may be possible to further reduce the thickness of the skeleton structure such as the side frame, but there is concern about the strength required for the seat structure only by reducing the thickness of the side frame or the like. is there. Therefore, it is conceivable to use a high tensile strength material with increased yield stress while reducing the thickness of the side frame or the like, or to add a beam material or the like between the opposing side frames. However, when such a beam member is added, the natural frequency in the left-right direction of the seat structure increases, and it becomes difficult to bend. In other words, since the rigidity is increased, the vibration / impact energy absorption performance due to the displacement of the skeleton structure is lowered.

  The present invention has been made in view of the above, and further, when the rigidity of the skeletal structure is increased, for example, while using a side frame having a thinner plate thickness than the conventional one for weight reduction, It is an object of the present invention to provide a seat structure excellent in vibration / impact energy absorption characteristics even in a structure provided with an additional beam material or the like for ensuring a predetermined rigidity or a structure using a high-tensile material.

  In order to solve the above problems, a seat structure of the present invention is a seat structure including a seat back portion and a seat cushion portion, and the seat cushion portion includes a pair of side frames and a pair of side frames. A front frame provided between the front portions and a rear frame provided between the rear portions of the pair of side frames are provided, and the front frame is spanned between the front portions of the pair of side frames. Supported by a torsion bar, and the rear frame is supported by a torsion bar spanned between the rear portions of the pair of side frames, and between the front frame and the rear frame, between an upper layer surface and a lower layer surface. A base net for cushion is hung around so as to form a loop with a gap.

  The seat back portion includes a back frame including a pair of side frames, an upper frame connecting the upper ends of the pair of side frames, and a lower frame connecting the lower ends of the pair of side frames; Preferably, the frame includes a back base net disposed so as to cover the pair of side frames of the frame.

  The seat back portion further has a pair of shoulder rib support portions corresponding to the shoulder ribs of the seated person, and the shoulder rib support portions are connected to each other, and has a substantially U-shape having a side covering portion extending downward from each shoulder rib support portion. Each side covering portion is disposed along each side frame via the back base net with the shoulder rib support portion facing upward, and at least one of the side covering portions when moved by the movement of the seated person It is preferable that the portion has a back movable pad capable of showing a relative operation with respect to the back base net.

  The seat back portion is formed with a width narrower than that of the back base net, and the back fixing is fixed to the back base net so that the lower portion is positioned at least at a portion corresponding to the pelvis from the pelvis of the seated person. It is preferable that a pad is provided, and the movable pad for back is disposed around the fixed pad for back.

  The pair of side frames of the back frame is formed of a plate-like member having a predetermined width and length, and the plate-like member is provided so that the width direction thereof is substantially along the front-rear direction. It is preferable that the edge and the rear edge are formed in a substantially linear shape.

  It is preferable that the back frame has a planar spring member that is stretched in the width direction at a position lower than the center part in the vertical direction of the pair of side frames.

  The pelvis support member further includes a pelvis support member that covers the front surface of the planar spring member, and when the front cover portion is pressed backward, the pelvis support member rotates backward and the planar shape It is preferable that the spring member be deformed.

  It can be set as the structure by which at least one part of the said planar spring member is embed | buried within the range of the thickness of the front surface coating | coated part of the said pelvis support member. It can be set as the structure by which at least one part of the said planar spring member is joined to the back surface of the front surface coating | coated part of the said pelvis support member. The pelvis support member preferably has a structure having a recess formed over a predetermined width. The interval in the width direction of the recesses is preferably in the range of 150 to 220 mm. The planar spring member is preferably provided with support blocks in the vicinity of both ends, and each support block is joined to the back surface of the front covering portion of the pelvis support member.

  It is preferable that inclined surfaces are provided in the vicinity of both ends in the width direction of the back surface of the front surface covering portion of the pelvis support member to which the support blocks are joined. It is preferable that the support blocks are engaged with the back surface of the front covering portion of the pelvis support member so as to be slidable in the lateral direction. The spacing between the support blocks is preferably in the range of 150 to 220 mm.

  The planar spring member is provided in a curved shape in which a central portion in the width direction bulges backward in plan view, and is attached so as to be deformed in the width direction when the pelvis support member is pressed backward. It is preferable.

  It is preferable that the pelvis support member has a substantially L-shaped cross section, and has a first groove portion in which a connecting rod that is spanned between the recliners of the seat back portion is disposed inside the vicinity of the corner portion. The pelvic support member is formed in a substantially L-shaped cross section, and an outer surface groove portion located on the rear side of the connecting rod spanned between the recliners of the seat back portion is formed on the outer surface in the vicinity of the corner portion. It is preferable that the bulging part which bulges downward is formed in one side part. The pelvic support member is preferably formed from a bead foam.

  After the lower end edge of the back base net is hung from the front edge side to the rear edge side of each side frame through the outside, it passes through the inside of each side frame and is pulled out to the front edge side and fixed. It is preferable. The cushion base net is formed by looping a single net member between a front frame and a rear frame, the end edges are engaged with each other by an engaging member, and the engaging member is It is preferable to be provided so as to be in contact with the front frame or the rear frame. The engaging member is preferably a slide fastener. The cushion surface layer cushion material provided on the cushion base net is preferably provided without being constrained by the cushion base net.

  According to the present invention, in the seat cushion portion, between the front frame and the rear frame that are elastically supported by the torsion bar, in a loop shape with a predetermined gap between the upper layer surface and the lower layer surface, Cushion base net is hung around. Therefore, when a centrifugal force acts on a curve, etc., there is a gap between the upper and lower surfaces, so one of the buttocks will sink and the reaction will cause the thigh, especially the other thigh to move upward. Trying to go up. As a result, the upper body of the human body generates a rotational force about the spinal column, the lateral force is dispersed into the longitudinal force, and the front frame is attracted rearward and raised. At that time, the pelvic support member acts to stabilize the posture on the person, and further, the turning force generated in the vertical direction acts to lower the raised thigh, particularly the other thigh downward, That is the power to stand on. As a result, the frictional force between the front frame and the thigh becomes a supporting force, and the lateral sliding of the human buttocks is suppressed by the above-mentioned turning force, and the posture when the inertial force in the left-right direction acts The supportability of can be improved. In addition, the force applied in the vertical direction is easily distributed to the two layers of the base net for cushion, and the layer received corresponding to the input G changes so that only the upper layer surface or both the upper layer surface and the lower layer surface are received. Therefore, it is also preferable in terms of vibration absorption and shock absorption characteristics.

  The back frame of the seat back part is composed of a pair of side frames, an upper frame and a lower frame, and other frames are arranged between the pair of side frames except that a pelvic support member is disposed near the lower part of the side frame. It is preferable to use a structure in which a base net for back is stretched on the back frame and the pelvis support member. If it does in this way, the rigidity of a peripheral part will become high among the base nets for backs, and the center part along the center line in the width direction will be easily bent back and forth. That is, since the support pressure on the body side outside the back base net is increased, when the left and right rolls are generated during traveling, the body tends to rotate around the spine and is easily converted into front and rear forces, Supportability becomes high. Therefore, when an inertial force in the left-right direction is applied during cornering or the like, a rotational motion occurs around the spine of the trunk, and it is easy to be pressed against the seat back portion. As described above, the side cushion is restrained from slipping in the seat cushion portion, and further, the back portion has a rotational motion centered on the spinal column. Therefore, the effect of suppressing the collapse of the posture due to the inertial force in the left-right direction is extremely high.

  Furthermore, when it is configured to include a movable back pad that is movably arranged with respect to the back base net supported by the back frame and has a shoulder rib support portion corresponding to the shoulder rib of the seated person, the shoulder rib is movable back pad. Is supported in contact with the shoulder rib support portion set in the above. As a result, the supportability of the shoulder ribs is further increased, and the above-mentioned rotational movement around the spinal column is more likely to occur, the force acts in the direction in which the shoulder ribs are pressed against the shoulder rib support portion, and the inertial force in the lateral direction functions. The collapse of the posture at the time can be further suppressed. On the other hand, since the scapula is a site that has a large range of movement, if the range of movement of the scapula is restricted, a cramped feeling occurs at the time of sitting, which hinders smooth breathing movement. The back movable pad moves according to the movement, so that the body movement is not hindered, so that a feeling of cramping or a breathing movement is not hindered. Even when the present invention is applied to a type having a high rigidity of the back frame and the cushion frame, the movable pad for back is easy to move, so that the vibration energy and the impact energy in the vertical direction input from the road surface are thereby reduced. Can be absorbed.

FIG. 1 is a front view showing a seat structure according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line CC of FIG. FIG. 3 is a side view of FIG. 4A is a cross-sectional view taken along line AA in FIG. 3 and a partial detail view thereof, and FIG. 4B is a diagram for explaining the movement. 5 is a cross-sectional view taken along line BB in FIG. FIG. 6 is an exploded perspective view showing the main part of FIG. FIG. 7 is a perspective view seen from the back side showing a state in which the back base net and the cushion base net are attached to the back frame and the cushion frame. FIG. 8 is a perspective view seen from the front side showing a state in which the movable pad for back, the pelvis support member, the base net for cushion, and the like are attached to the back frame and the cushion frame. FIG. 9 is a front view showing the back frame, the cushion frame, and the pelvis support member. 10 is a cross-sectional view taken along line BB in FIG. FIG. 11 is a perspective view showing configurations of a back frame and a cushion frame according to the embodiment. FIG. 12 is an external view showing a surface cushion material for a cushion. 13 is a cross-sectional view taken along line A in FIG. FIG. 14 is a view showing the pelvic support member used in the above embodiment, wherein (a) is a perspective view, (b) is a side view, (c) is a front view, (d) is a plan view, and (e). ) Is a cross-sectional view taken along line AA in FIG. FIG. 15 is a view showing another example of a pelvic support member, in which (a) is a perspective view, (b) is a side view, (c) is a front view, and (d) is an AA view of (c). FIG. FIG. 16 is a view showing still another example of the pelvic support member, where (a) is a perspective view seen from the back side before joining the S spring, and (b) is a back view showing a state where the S spring is joined. The perspective view seen from the side, (c) is the perspective view seen from the front side, (d) is AA sectional drawing of (c). FIG. 17 is a view showing still another example of the pelvic support member, where (a) is a perspective view seen from the back side before joining the S spring, and (b) is a back view showing a state where the S spring is joined. The perspective view seen from the side, (c) is the perspective view seen from the front side, (d) is AA sectional drawing of (c). FIG. 18 is a view showing a configuration of a back frame and a cushion frame in which still another example of the pelvis support member is arranged. 19 is a cross-sectional view taken along line AA in FIG. 20A and 20B are views showing the pelvic support member employed in FIGS. 18 and 19, in which FIG. 20A is a perspective view seen from the back side of the upper body joined with the S spring, and FIG. 20B joined the S spring. The perspective view seen from the back side before carrying out, (c) is a front view of the state which joined the S spring, (d) is the rear view of the state which joined the S spring, (e) is AA of (d). It is sectional drawing. FIGS. 21A to 21C are views for explaining the operation of the cushion base net used in the embodiment. FIG. 22 is a diagram for explaining the operation of the cushion base net used in the embodiment. FIG. 23 is a diagram for explaining the operation when the cushion base net used in the embodiment is applied to a sofa. FIG. 24 is a view showing a body pressure distribution of a subject in a static state when seated on a test example seat, (a) is a body pressure part distribution in a seat back part, and (b) is a seat cushion part. The body pressure distribution in is shown. FIGS. 25A to 25J are diagrams showing time series changes in body pressure distribution in the seat back portions of the test example sheet and the comparative example sheet during S-curve traveling. FIGS. 26A to 26K are diagrams showing changes in body pressure distribution in the seat back portions of the test example seat and the comparative example seat during the S-curve running, and are continued from FIG. 27A to 27C show the case where the angle of the seat back portion is tightened (upright of (a)), when slightly loosened (middle of (b)), and when further loosened (of (c)) FIG. 5 is a view showing body pressure distributions of a seat back portion and a seat cushion portion when turning a left curve in (relaxation). FIG. 28 is a diagram showing the vibration transmissibility of the test example sheet and the comparative example sheet. FIG. 29 is a diagram showing vibration transmissibility measured by seating subjects with different weights on a test example sheet. FIG. 30 is a diagram showing the measurement results of the fatigue level of the subject using the test example sheet and the comparative example sheet.

  Hereinafter, the present invention will be described in more detail based on the embodiments shown in the drawings. First, a vehicle seat structure 1 according to an embodiment of the present invention will be described with reference to FIGS. As shown in these drawings, the seat structure 1 of the present embodiment includes a seat cushion portion 10 and a seat back portion 20 provided to be tiltable with respect to the seat cushion portion 10.

  The cushion frame 100 constituting the seat cushion portion 10 includes a pair of side frames 110 and 120 arranged at a predetermined interval, a front frame 130 arranged on the front edge side of the side frames 110 and 120, and a rear edge side. And a rear frame 140 disposed on the rear side.

  The front frame 130 is formed in a substantially U shape having a horizontal portion 131 and arm portions 132 and 132 bent in a direction substantially perpendicular to both sides of the horizontal portion 131. The base end portions of the arm portions 132 and 132 are connected to first torsion bars 150 that are spanned between the vicinity of the front edge portions of the side frames 110 and 120, respectively. As a result, the elastic force of the first torsion bar 150 acts when the arm portions 132 and 132 and the horizontal portion 131 positioned therebetween rotate in the front-rear direction.

  Similar to the front frame 130 described above, the rear frame 140 has a substantially U-shape having a horizontal portion 141 and arm portions 142 and 142 bent in a direction substantially perpendicular to both sides of the horizontal portion 141. Formed. The base end portions of the arm portions 142 and 142 are connected to the second torsion bar 160 spanned between the vicinity of the rear edge portions of the side frames 110 and 120, respectively. As a result, the elastic force of the second torsion bar 160 acts when the arm portions 142, 142 and the horizontal portion 141 positioned therebetween rotate in the front-rear direction. In the present embodiment, in order to increase the strength of the cushion frame 100, a reinforcing pipe 125 spanned between the two side frames 110 and 120 is disposed on the rear side of the side frames 110 and 120 (see FIG. 11). The restoring force of the first torsion bar 150 and the second torsion bar 160 becomes a force that elastically supports the occupant, and the rotational force that converts the lateral force into the front-rear direction while allowing the occupant to move. One of the factors that arise.

  The cushion base net 170 is stretched between the horizontal portion 131 of the front frame 130 and the horizontal portion 141 of the rear frame 140 of the cushion frame 100 described above. The cushion base net 170 may be a two-dimensional fabric, a two-dimensional fabric laminated with a thin urethane material, or a three-dimensional solid knitted fabric disclosed by the present applicant in JP-A-2003-182427. Can do.

  One cushion base net 170 is looped around the horizontal portion 131 of the front frame 130 and the horizontal portion 141 of the rear frame 140, and the end edges are connected to each other. . By wrapping around the loop, the cushion base net 170 has a two-layer structure of an upper layer portion 171 and a lower layer portion 172, and a gap 173 is generated between the two layers. The connecting method of the edge portions of the base net 170 for cushion is arbitrary, and it can be connected by sewing means, but is engaged through an engaging member (not shown) such as a slide fastener, and the engaging member However, it is preferable to arrange them so as to be in contact with the front frame 130 or the rear frame 140. By doing so, the frictional force between the engagement member such as the slide fastener and the front frame 130 or the rear frame 140 is increased, and the front frame of the cushion base net 170 hung around in a loop shape. A relative positional shift with respect to 130 and the rear frame 140 can be suppressed.

  A cushion surface layer cushion material 180 is provided on the cushion base net 170. As the cushion surface layer cushion material 180, a three-dimensional solid knitted fabric, a bead foam, a urethane material, or a laminate thereof can be used. In this embodiment, as shown in FIG. 2 and FIG. 13, a three-dimensional solid knitted fabric 183 encapsulated between two upper and lower fabrics 181 and 182 and a bead foam 184 are used. That is, the foam foam 184 is laminated on the cushion base net 170, and the three-dimensional three-dimensional knitted fabric 183 sandwiched between the fabrics 181 and 182 is further laminated thereon. Further, the fabric 182 and the bead foam 184 disposed on the lower side are integrally fixed via the surface fastener 185, but the bead foam 184 and the cushion base net 170 are fixed. In other words, the bead foam 184 is placed on the cushion base net 170. Then, the side covering skin 186 is joined to the edge measuring portion of the upper fabric 181 and the side covering skin 186 is engaged with the cushion frame 100 via the engaging resin plate 186a. Therefore, the cushion surface layer cushion material 180 can be displaced relative to the cushion base net 170, and is particularly useful for absorbing vibration in the front-rear direction.

  The three-dimensional solid knitted fabric 183 includes, for example, a pair of ground knitted fabrics that are arranged apart from each other as disclosed in JP-A-2002-331603, JP-A-2003-182427, and the like. This is a knitted fabric having a three-dimensional three-dimensional structure having a large number of connecting yarns that reciprocate between a pair of ground knitted fabrics to couple them together. As the bead foam 184, for example, a foam molded body by a resin bead method containing at least one of polystyrene, polypropylene, and polyethylene can be used.

  Here, the three-dimensional three-dimensional knitted fabric 183 (in addition to the three-dimensional three-dimensional knitted fabric 183, it is of course possible to use a cushion material such as a urethane pad, a urethane pad or a laminate of a three-dimensional three-dimensional knitted fabric). Thus, although sandwiched between the upper and lower fabrics 181 and 182, it is preferable that the lower fabric 182 is made of a material that is less stretched than the upper fabric 181. For example, the upper fabric 181 can be synthetic leather, genuine leather, or the like, and the lower fabric 182 can be a non-woven fabric, a canvas, a two-dimensional net, a three-dimensional solid knitted fabric, or the like that has a smaller elongation. be able to. In addition to this, a thin plate-like body made of polypropylene or a bead foam formed in a sheet shape can be sewn to the lower fabric 182 and further laminated. The three-dimensional solid knitted fabric 183 having a predetermined thickness is sandwiched between the two fabrics 181 and 182, and the two fabrics 181 and 182 are directly sewn along a desired line. Thereby, since the upper fabric 181 is easier to stretch, as shown in FIGS. 12 and 13, the portion of the upper fabric 181 along the predetermined line is drawn in the direction of the lower fabric 182, A deep groove 181a is formed. By making such a groove 181a, the elastic function of the three-dimensional solid knitted fabric 183 can be sufficiently exerted, and a volume feeling can be produced when viewed from the surface of the seat cushion portion 10. In the case of a conventional cushioning material using a urethane pad with a predetermined thickness, the skin was caught in a groove formed in the urethane pad and engaged with the groove bottom. Since it is only necessary to sew the appropriate positions of the fabrics 181 and 182 using different fabrics 181 and 182, the groove 181 a can be easily formed.

  The groove 181a can also be formed by laminating a urethane pad on the fabrics 181 and 182 and so-called tapping.

  As shown in FIGS. 9 to 11, the back frame 200 constituting the seat back portion 20 is formed between a pair of side frames 210 and 220 arranged at a predetermined interval and the upper portions of the side frames 210 and 220. The first upper frame 230 and the second upper frame 240 are disposed, and the lower frame 250 is disposed between the lower portions of the side frames 210 and 220. The lower portions of the side frames 210 and 220 of the back frame 200 are connected to the rear portions of the side frames 110 and 120 of the cushion frame 100 via the reclining adjuster 40, and the back frame 200 can tilt forward and backward with respect to the cushion frame 100. Provided.

  Each of the side frames 210 and 220 of the back frame 200 is formed of a plate-like member having a predetermined width, and the width direction thereof is arranged in a direction substantially along the front-rear direction. Specifically, as shown in FIGS. 9 to 11, the width of the back frame 200 gradually increases from the upper side to the lower side, and the inclination of the back frame 200 with respect to the cushion frame 100 is approximately 90 degrees. When viewed from the side in the state of the degree, the front edge portions 210a and 220a are along a line inclined in a direction protruding forward from the upper side to the lower side, and the rear edge portions 210b and 220b are substantially vertical. It has a shape along a straight line. Further, both the front edge portions 210a and 220a and the rear edge portions 210b and 220b are substantially straight lines with no large unevenness in the middle.

  The first upper frame 230 includes a lateral frame portion 231 slightly inclined downward toward the outside, and the front edges of the pair of side frames 210 and 220 extending downward from the end portions of the lateral frame portion 231. It is a structure which has the vertical direction frame part 232 each connected by the upper end part. A headrest support portion 233 that is bent in a substantially inverted U shape is integrally formed at a substantially central portion of the lateral frame portion 231.

  The second upper frame 240 includes a lateral frame portion 241 that is slightly inclined downward toward the outside, and each trailing edge of the pair of side frames 210 and 220 extending downward from each end portion of the lateral frame portion 241. It has a structure having a vertical frame portion 242 respectively connected to the upper end portion.

  Here, in the present embodiment, between the side frames 210 and 220, from the lateral frame portions 231 and 241 of the first upper frame 230 and the second upper frame 240, lower end portions of the rear edges of the side frames 210 and 220, respectively. In the space up to the lower frame 250 spanned between, there is an intrusion space 260 in which no other frame is arranged.

  In a position slightly above the lower frame 250, that is, in a position corresponding to the vicinity of the waist from the upper part of the seated person's pelvis, an S spring 251 as a planar spring member spans around the front edge side of the side frames 210 and 220. Has been. The S spring 251 abuts near the waist from the seated person's pelvis and gives a sense of stroke in the front-rear direction. The S spring 251 is preferably provided in an arch shape in which the central portion in the width direction bulges forward or backward. If it is formed in an arch shape that bulges forward, it is easy to feel a stroke, and if it is formed in an arch shape that bulges backward, a fit feeling along the back of a person is improved. Since there is a problem of the preference of the seated person, it can be selected depending on the type of vehicle (sedan type, sports type, etc.) such as an automobile in which the seat structure of this embodiment is installed. When the S spring 251 is provided, when pressed on the upper edge side, the S spring 251 rotates rearward about the lower edge side, and the pelvis can be supported by the reaction force of the spring from diagonally downward to diagonally upward. Further, when an inertial force is input in the left-right direction, a stroke with a small reaction force is generated due to a relatively small spring constant, and the pelvis is firmly supported while causing a rotational motion. Note that the S spring 251 is preferably provided integrally with the pelvis support member 252 shown in FIGS.

  As shown in FIGS. 6, 8 to 10, and 14, the pelvis support member 252 is formed by processing a bead foam into a substantially L shape in a side view, and is formed with a narrower width than the S spring 251. And has a front surface covering portion 252a, and an upper portion thereof is a warped portion 252b. The front surface covering portion 252a covers the front surface of the S spring 251. It is only necessary to cover the front surface of the S spring 251, and the back surface of the front surface covering portion 252 a may be integrated with the front surface of the front surface covering portion 251 by bonding means such as adhesion. The S spring 251 is integrally molded so as to be embedded within the thickness range of the portion 252a. As shown in FIGS. 8 to 10, the warped portion 252 b extends upward from the front cover portion 252 a to a position corresponding to the waist of the seated person, and has an upper end edge slightly warped backward. By having the warped portion 252b, when the seat occupant applies a load to the rear, a force is applied to rotate the warped portion 252b diagonally downward, so that the reaction force is from the pelvis of the seated person to the waist. Is pressed from diagonally downward to diagonally upward.

  A first groove 252d is formed inside the vicinity of the corner of the substantially L-shaped pelvis support member 252. The pelvis support member 252 connects the first groove 252d between the left and right recliners. It is arranged around. Further, a second groove portion 252e is formed further rearward than the first groove portion 252d, and the second groove portion 252e is arranged to be engaged with the lower edge portion of the lower frame 250. Thereby, the substantially L-shaped pelvic support member 252 has a front-end covering portion 252a supported by the S spring 251 and a second groove portion 252e on the rear side supported by the lower frame 250. Since it also has elasticity, it becomes an elastic member for preventing breakage of the connecting rod 295 when the carrier carrier claw is inserted below the connecting rod 295 and conveyed in the production line of the seat structure 1.

  Further, by providing the pelvis support member 252 integrally with the S spring 251, the pelvis support member 252 projects the vicinity of the lower end of the back base net 270, which will be described later, to the front by the elasticity of the S spring 251. Help get shape.

  In this embodiment, the S spring 251 is used as the planar spring member integrated with the pelvis support member 252. However, a formed wire, a puller flex, or the like can be used instead of the S spring 251.

  A back base net 270 is supported on the side frames 210 and 220 and the first and second upper frames 230 and 240 of the back frame 200. 2 to 7, the back base net 270 includes a front cover portion 271 that covers the front side of the back frame 200, a back cover portion 272 that covers the back side, a side frame 210, Side surface covering portions 273 and 274 covering 220 are provided.

  The front covering portion 271 has a size from the horizontal frame portions 231 and 241 of the first upper frame 230 and the second upper frame 240 to a position corresponding to the lower frame 250. As shown in FIG. 2, the back cover portion 272 is provided on the respective rear edge sides of the side frames 210 and 220 up to the vicinity of the center in the vertical direction. The back surface covering portion 272 has a bag shape formed integrally with the front surface covering portion 271, and a slit 275 is formed at the boundary between the upper edge portion of the front surface covering portion 271 and the back surface covering portion 272. The headrest support 233 is covered so as to protrude from the head (see FIGS. 6 and 7).

  The side surface covering portions 273 and 274 are integrally provided on both sides of the front surface covering portion 271, and lower end edges 273 a and 274 a are hung from the front edge side to the rear edge side of the side frames 210 and 220 through the outside. After being rotated, it passes through the inside of each side frame 210, 220 and is fixed so as to be pulled out to the front edge side (see FIG. 7).

  By stretching the back base net 270 in this way, the portions near the side frames 210 and 220 corresponding to the body side of the seated person become parts with small bending back and forth, and the center line of the back base net 270 The part corresponding to the spinal column of the trunk along the trunk is easily bent back and forth. As a result, if an inertial force acts in the left-right direction during cornering, a rotational movement around the spine of the trunk tends to occur. When the rotational movement occurs, if the portion along the center line bends back and forth, the support pressure of the S spring 251 increases. This increased support pressure prevents the body from shifting in the left-right direction due to the frictional force generated between the seated person and the seat back portion 20 and the rotational force of the rotation.

  The seat back portion 20 is further formed with a narrower width than the back base net 270, and the back portion 20 is fixed to the back base net 270 so that the lower portion is located at a position corresponding to at least the waist portion of the seated person. A fixing pad 280 is provided (see FIGS. 4 and 6). The back fixing pad 280 is formed with a predetermined thickness from, for example, a three-dimensional solid knitted fabric, a urethane material, a bead foam or the like. Specifically, as shown in FIG. 4, the center line portions of the back surface cushion material 300 and the back base net 270 that cover the surface of the back fixing pad 280 are sewn together, Both side edges of the front layer cushion material 300 and the front covering portion 271 of the back base net 270 are also sewn, and fixedly disposed between the left and right back surface cushion materials 300 around the center line and the back base net 270. Is done. Further, by using the back surface cushion material 300 that is easier to extend than the back base net 270, as shown in FIG. 4, the back surface cushion material 300 is pulled along the sewing line, so that A recess 300a for providing a cushion feeling and volume feeling of the fixed pad 280 is formed. By having this back fixing pad 280, the back-and-forth stroke feeling from the vicinity of the waist to the chest is increased, and the support of the waist is enhanced. In order to reduce the weight, the back fixing pad 280 is preferably formed from a bead foam.

  Around the back fixed pad 280, a back movable pad 290 is disposed so as to cover the side frames 210 and 220 via the back base net 270. The back movable pad 290 has a pair of shoulder rib support portions 291 and 292 corresponding to the shoulder ribs of the seated person, and the shoulder rib support portions 291 and 292 are connected to each other and extend downward from the shoulder rib support portions 291 and 292. It is formed in a substantially U shape when viewed from the front having the covering portions 293 and 294. The side covering portions 293 and 294 are formed in a substantially U-shaped cross section so as to cover the front side, side surface side, and back side of the side frames 210 and 220. Then, on the back frame 200 covered with the back base net 270 as described above, the headrest support portion 233 is moved upward from between the shoulder rib support portions 291 and 292 so that the shoulder rib support portions 291 and 292 are positioned on the upper side. The side frames 210 and 220 are disposed so as to cover the side covering portions 293 and 294 having a substantially U-shaped cross section. Further, as shown in FIG. 4, the back surface cushion material 300 covers the outer surface of the back movable pad 290 (side covering portions 293 and 294), but covers the back movable pad 290 to allow movement. Is done. As a result, at least the side covering portions 293 and 294 of the movable back pad 290 follow the movement of the person as shown by the solid line from the position of the imaginary line in FIG. 270 indicates a relatively independent movement.

  The back movable pad 290 can also be formed from a three-dimensional solid knitted fabric, a urethane material, a bead foam, or the like. However, similarly to the above, it is preferable to form the back movable pad 290 from a bead foam. The bead foam cannot have a small spring constant when compressed by a pressure plate having a large area (diameter of 98 mm or more), and therefore the upper end of the back movable pad 290 (the headrest support portion 233 is inserted through the top). In other words, the spring constant in the thickness direction can be reduced in a pseudo manner by generating displacement by the elasticity of the beam with a cantilever structure having a fixed end. Therefore, it is desirable that the lower portions of the side covering portions 293 and 294 of the movable back pad 290 are open (see FIG. 6). When the back surface cushioning material 300 is pressed against a person's back, the side covering portions 293 and 294 of the movable back pad 290 are not fixed at the lower portion, so that the back around the side frames 210 and 220 is back. The base net 270 moves relatively inwardly (from the position indicated by the imaginary line in FIG. 4B to the position indicated by the solid line), and the stroke with little reaction force. A feeling is generated. Thereby, a person feels a small spring constant.

  By having the back movable pad 290, the shoulder ribs of the seated person abut against the shoulder rib support portions 291 and 292. Since the shoulder rib support portions 291 and 292 are located in the back base net 270 near the side frames 210 and 220, they are portions with less deflection in the front-rear direction than the portions along the center line. Therefore, when the shoulder rib of the seated person comes into contact, the shoulder rib support portions 291 and 292 exert a predetermined support pressure. As a result, a high frictional force is generated between the shoulder ribs and the shoulder rib support portions 291 and 292 compared to the portion corresponding to the center line of the back base net 270 which is easily bent back and forth, so that the inertial force in the left and right direction is increased. When working, the lateral displacement of the scapula support portions 291 and 292 is suppressed, and rotational motion about the spinal column is likely to occur with the pelvis as the input point. On the other hand, the back movable pad 290 is merely disposed so as to cover the side frames 210 and 220 by the side cover portions 293 and 294, and follows the movement of the person as described above, and S The elastic force by the spring 251 acts to move independently from the back base net 270. The human shoulder rib, pelvis or waist is a part that moves well. For example, if the shoulder rib support portions 291 and 292 are fixedly arranged, the range of movement of the shoulder rib is restricted, and a cramped feeling is generated. It interferes with respiratory movement. However, if the back movable pad 290 is movably disposed with respect to the back base net 270 in this way, the back movable pad 290 moves according to the movement of the shoulder ribs, and thereby the body movement is not hindered. Does not occur or obstructs respiratory movement. Even if the rigidity of the frame of the back frame 200 and the cushion frame 100 is increased, the back movable pad 290 is easy to move, thereby absorbing the vertical vibration energy and impact energy input from the road surface. Can do. In particular, in the present embodiment, the front edge portions 10a and 220a and the rear edge portions 210b and 220b of the side frames 210 and 220 of the back frame 200 are formed in a substantially straight shape without large unevenness as described above. The movable pad 290 is easily moved up and down.

  According to this embodiment, between the upper layer surface 171 and the lower layer surface 172 between the front frame 130 and the rear frame 140 elastically supported by the seat cushion portion 10, the first and second torsion bars 150, 160. A cushion base net 170 is looped around in a loop with a predetermined gap 173 therebetween. Therefore, when a centrifugal force acts on a curve or the like, since there is a gap 173 between the upper layer surface 171 and the lower layer surface 172, one of the buttocks tends to sink and the reaction causes the thigh, particularly the other thigh. The part tries to go up. When one of the buttocks sinks and the other thigh tries to rise upward, the front frame 130 is pulled up in the backward direction (the state shown in FIG. 21B). At that time, in order to maintain the posture, the person applies a struting force to lower the raised thigh, particularly the other thigh (downward state in FIG. 21C). As a result, the frictional force between the front frame 130 and the thigh is increased, the lateral sliding of the human buttocks is suppressed, and the supportability of the posture when the inertial force in the left-right direction acts is increased. be able to. In addition, this means that the left and right buttocks are supported by cushion materials having different spring constants, and as a result, a person can feel as an even feeling of support, creating a sense of security.

  Further, since the force applied in the vertical direction is dispersed in the two layers of the cushion base net 170, the load mass dependency is eliminated, which is preferable in terms of vibration absorption and shock absorption characteristics. In addition, when stretched in a loop shape, when sitting so that the center of gravity is located near the rear part of the seat cushion part 10, the upper layer part 171 near the rear part approaches the lower layer part 172 in the base net 170 for cushioning, It changes so that the gap 173 between the upper and lower two layers is eliminated. On the other hand, since the gap 173 between the upper layer portion 171 and the lower layer portion 172 close to the front portion remains in the normal state, the seat angle θ1 increases from θ1 to θ2 as shown in FIG. The support pressure increases and helps maintain a stable sitting posture.

  Further, in the seat back portion 20, as described above, the center portion of the back base net 270 along the center line in the width direction is easily bent back and forth, and the support pressure on the body side on the outside increases, so When left and right rolls are generated, the body rotates around the spinal column and is easily converted into a front-rear force, which increases the supportability of the seated person. Therefore, when cornering, for example, if an inertial force in the left-right direction is applied, rotational movement about the spine of the trunk tends to occur. As described above, while the side cushion is restrained from side slip in the seat cushion portion 10, the back portion is converted into a rotational motion centered on the spinal column. high.

  Furthermore, since the back movable pad 290 having the shoulder rib support portions 291 and 292 corresponding to the shoulder ribs of the seated person is provided so as to be movable with respect to the back base net 270 supported by the back frame 200, the shoulder ribs are provided. The shoulder rib support portions 291 and 292 set on the back movable pad 290 are in contact with and supported. As a result, the supportability of the scapula is further increased, the rotational movement about the spinal column becomes easier to occur, and the posture collapse when the inertial force in the left-right direction functions can be further suppressed. Further, in this embodiment, the reinforcing frame 125 is disposed to increase the rigidity of the cushion frame 100, and the natural frequency in the lateral direction of the frame itself is increased to reduce the vibration absorption characteristics. Since the movable pad 290 for movement is easy to move, the movement functions to absorb the vibration energy and the impact energy in the vertical direction input from the road surface. In other words, in order to reduce the vibration transmitted to the head, especially the brain as much as possible, in the vicinity of the trunk, the vibrations propagating on the surface of the body are attenuated by the deep muscles and built-in functions as dampers and dynamic dampers. However, the skeletal ribs and pelvis, which are far away from the trunk, have a small movement, such as the skeleton, because they have very little damping effect. is there. Further, as in the present embodiment, when the support pressure in the portion along the spinal column is smaller than the support pressure on the outer side, the curve of the spine tends to move. The curve of the spine moves due to breathing (deep breathing) and body movements, which causes fluctuations in internal pressure in the intervertebral disc, and nutritional supply and drainage of waste inside and outside the disc are actively performed, contributing to the prevention of back pain.

  These effects are summarized as follows. In other words, vibration absorption is improved by supporting the waist with a soft elastic force having a stroke (elastic force acting by the back movable pad 290, the back base net 270, the pelvis support member 252 and the S spring 251). In addition, since the inertial force in the left-right direction is converted into a force in the up-down direction with respect to the seating surface to generate a rotational force, the posture is also stabilized. This reduces the onset of back pain and eliminates the sense of incongruity when posture changes (feeling that something is touching or being disturbed by something), like when you are slowly in the room Induced to a relaxed state. This is because it does not interfere with the movement of the spine, which is flexible in the longitudinal direction. In addition, since the spinal column has high rigidity in the left-right direction, there is a sense of incongruity that movement is hindered by something when trying to move in the left-right direction. Is killed. In order to prevent the spinal curve from becoming a stooped posture, the outside of the pelvis and the lower back (a distance of 75 mm or more from the center in the width direction, preferably about 90 mm away) It becomes the pelvic upper support and the body side support that support the iliac crest. In addition, these lower back and pelvic support also serve to generate rotational force on the trunk while preventing the pelvis from turning backward. In the sitting posture in which the movements and movements in these states support the lower limbs with the heel, the muscles of the lower limbs called the second heart are moved, and the return of the veins to the heart is promoted. As a result, the blood circulation in the body is improved, the progress of fatigue is suppressed, and the muscle function and autonomic nerve function used before reaching the sitting posture are restored.

  Further, the back frame 200 extends from the lateral frame portions 231 and 241 of the first upper frame 230 and the second upper frame 240 to the lower frame 250 spanned between the lower edge portions of the rear edges of the side frames 210 and 220. There is an intrusion space 260 in which no other frame is arranged. Therefore, the seating person's back has high support pressure in the vicinity of the shoulder ribs and in the vicinity of the pelvis from the lower waist. Therefore, when an impact of a predetermined level or more is received due to the rear-end collision, the human body is displaced in a direction in which the base net 270 stretched on the back frame 200 is pushed. When the force for pushing the human body exceeds the tension of the back base net 270, the human body enters the intrusion space 260 while being supported by the back base net 270. When the back base net 270 is further pushed in, the front edge side of the side frames 210 and 220 is deformed so as to fall inward, and while further energy absorption is made, the human body further intrudes into the indentation space 260, The impact force will be attenuated. Further, the S spring 251 built in the pelvis support member 252 supporting the lumbar region and the pelvis is rotated downward by being pushed downward by a concentrated load. Alternatively, the connection portion with the pelvis support member 252 is released, the S spring 251 rotates, the reaction force decreases, and the upper body of the person enters the intrusion space 260 of the back frame 200. As a result, the human head is quickly supported by and supported by the headrest supported by the headrest support portion 233, and damage to the neck due to a sudden backward tilt of the head can be suppressed.

  Here, the pelvis support member 252 may have a structure as shown in FIG. The pelvic support member 252 has a width of 75 mm or more from the center in the width direction of the front covering portion 252a, preferably about 90 mm (around 150 mm or more, preferably 150 to 220 mm, more preferably 170 to 190 mm). And has a recess 252f formed. Accordingly, the S spring 251 is embedded in both side portions 252g sandwiching the concave portion 252f, and is exposed to the outside at a portion corresponding to the concave portion 252f. As a result, the back base net 270 covered with the pelvic support member 252 is more easily deflected at the portion corresponding to the recess 252f, and the rotational movement about the trunk spine at the time of cornering is further generated. It becomes easy. In addition, although the recessed part 252f may be formed in the predetermined depth from the back surface side of the front surface coating part 252a, you may form as a hole penetrated in the thickness direction. In any case, the S spring 251 is not in contact with the front surface covering portion 252a in the portion corresponding to the concave portion 252f, and has a gap so that the S spring 251 has bending elasticity and tensile elasticity. It is preferable to make the spring characteristics of the S spring 251 softer.

  A pelvic support member 252 as shown in FIG. 16 can also be used. The pelvis support member 252 is provided with a support block (hereinafter referred to as “S spring support block”) 251a integrally in the vicinity of both ends of the S spring 251 without embedding the S spring 251 in the front covering portion 252a. The support block 251a is bonded and integrated with the back surface of the front cover portion 252a. The S spring support block 251a is formed of, for example, a bead foam, and is provided near both ends of the S spring 251. The interval between the S spring support blocks 251a and 251a is 150 mm or more, preferably 150 to 220 mm, more preferably 170 to 190 mm, as described above. Further, as shown in FIG. 16, it is preferable to form angle-shaped joint portions 252h and 252h at a predetermined interval on the back surface of the front surface covering portion 252a. The S spring support blocks 251a and 251a are bonded to the outer inclined surfaces of the mountain-shaped joint portions 252h and 252h, respectively. Thereby, the S spring 251 is curved so that the central portion in the width direction swells rearward, and a gap is formed between the portion located between the S spring support blocks 251a and 251a and the front cover portion 252a. . Then, when the front surface covering portion 252a is pressed backward, the S spring 251 not only simply rotates the upper edge side backward with the lower edge as the center, but also the width direction of the S spring 251, that is, the direction in which the S character is broken. The force is also applied to deform. As a result, the elasticity of the S spring 251 in the width direction also acts, and the pelvic support member 252 including the S spring 251 can support the upper body of the person with a softer elasticity, and promote the above-described rotational movement of the upper body during cornering. be able to.

  As the pelvis support member 252, the one shown in FIG. 17 can be used. The pelvis support member 252 is provided with inclined surfaces 252i and 252i on the back surface of the front covering portion 252a, having a thickness near the center and gradually decreasing in thickness near both ends. In addition, grooves 252j and 252j are formed in the inclined surfaces 252i and 252i in the lateral direction. S spring support blocks 251a and 251a are provided in the vicinity of both sides of the S spring 251 as in FIG. 16, and the S spring support blocks 251a and 251a are attached so as to face the inclined surfaces 252i and 252i. . Protruding pieces 251b and 251b are provided on the surfaces of the S spring support blocks 251a and 251a facing the inclined surfaces 252i and 252i. The protruding pieces 251b and 251b are engaged with the grooves 252j and 252j of the inclined surfaces 252i and 252i. Is done. Other configurations are the same as those in FIG.

  In the pelvis support member 252 of the aspect shown in FIG. 17, when the front covering portion 252a is pressed backward, the S spring 251 not only simply rotates the upper end edge backward about the lower end edge but also supports the S spring. Since the protrusions 251b and 251b of the blocks 251a and 251a are integrated by engagement with the grooves 252j and 252j of the inclined surfaces 252i and 252i, the S spring 251 has a force in the width direction, that is, the direction of breaking the S character. When acted, the projecting pieces 251b and 251b can slide in the lateral direction along the groove portions 252j and 252j, and the deformation of the S spring 251 in the width direction is more easily performed than that in FIG. That is, the pelvis support member 252 shown in FIG. 17 can support the human upper body with softer elasticity than the pelvis support member 252 shown in FIG.

  18 to 20 are diagrams in which a pelvic support member 252 according to still another aspect is disposed. 19 and 20, the pelvis support member 252 is formed in a substantially L-shaped cross section. However, as shown in FIG. 14, the pelvic support member 252 has a substantially L-shaped pelvic support member 252 near the corner. The first groove portion 252d formed inside is not provided. Instead of the first groove portion 252d, an outer surface groove portion 252m is formed in the width direction near the corner portion of the substantially L-shaped pelvic support member 252, and the rear portion of the outer surface groove portion 252m is thicker than the first groove portion 252d. It is the exit part 252n. A groove portion 252p that engages with the lower frame 250 is formed on the inner surface side of the bulging portion 252n, like the second groove portion 252e of FIG.

  The pelvis support member 252 shown in FIGS. 18 to 20 is arranged such that the outer surface groove portion 252m is along the rear side of the connecting rod 295 between the recliners. As a result, the bulging portion 252n is lower than the lower portion of the connecting rod 295. It is arranged at the position where it bulges. With such a configuration, when the pelvis support member 252 is rotated backward, it is in a direction away from the connecting rod 295. Therefore, the stroke at the time of backward rotation is shown in FIG. There is an advantage that it can be taken larger than the one. As a result, the pelvis support member 252 is more easily rotated backward, and a rotational motion about the spinal column of the trunk is more likely to occur during cornering. In addition, since the outer surface groove portion 252m is arranged along the rear side of the connecting rod 295, it has the above-described bulged portion 252n. This bulged portion 252n functions as an elastic member for preventing damage to the connecting rod 295 when the wire is inserted and conveyed below the connecting rod 295. It is to be noted that an inclined surface 252r is provided on the back surface of the front cover portion 252a, and S spring support blocks 251a and 251a provided near both ends of the S spring 251 are joined to the inclined surface 252r in the same manner as in the above embodiment. (See FIG. 20).

(Test example)
First, the seat structure 1 shown in FIG. 1 (“test example seat”) was set in the driver's seat of a sedan type passenger car, and the body pressure distribution when the subject was seated in a static state was examined. FIG. 24A shows the body pressure distribution in the seat back portion, and FIG. 24B shows the body pressure distribution in the seat cushion portion. As a result, in the seat back portion, it can be seen that the support pressure in the body side portion is higher than the position along the spine of the upper body. Further, among the body side portions, the body pressure in the vicinity corresponding to the shoulder ribs and the pelvis (particularly the upper portion) is high, and in the seat cushion portion, the body pressure in the portion corresponding to the thigh is also high. Therefore, it can be seen that the test example sheet is a sheet having high supportability of the shoulder ribs, the pelvis (particularly the upper part), and the thigh.

  Next, a change in body pressure distribution was examined when the test example seat was run on an S-shaped curve at a speed of 80 km / h with a sedan type passenger car set in the driver's seat. For comparison, genuine passenger car seats used in the test ("Comparative seat": a seat structure that uses urethane pads as cushion materials for both the seat cushion and seat back, and the appearance and size are shown in the figure. The same test was performed in the same manner as in the embodiment shown in FIG. 25 and 26 show changes in body pressure distribution in the seat back portion 20. The period from 0.0 to 6.5 sec is from the time immediately before entering the right curve to the time when the right curve is released, and 7.0 to 10.0 sec is the period from after the right curve is released to the time when the left curve is released. Further, the left column at each measurement time is the result of the test example sheet, and the right column is the result of the comparative example sheet.

  In the case of the comparative example seat, in the right curve, a portion with a high body pressure is generated on the left side portion of the seat back portion between 0.5 and 4.5 seconds, particularly at 2.0 to 4.0 seconds, It can be seen that the subject's back is displaced to the left of the seat back. On the other hand, in the case of the test example sheet, the shift to the left side is clearly small. In addition, the contact area of the back portion in the meantime was between about 760 and about 1080 cm 2 for the comparative example sheet, whereas it was about 1,020 to about 1270 cm 2 for the test example sheet, and the back portion was stable in the test example sheet. And was in contact with the seat back.

  The same applies to the left curve, and the body pressure distribution on the right side of the comparative example sheet is high between 7.0 and 10.0 sec, particularly after 9.0 sec. In contrast, in the test example sheet, the body pressure distribution on the right side is only slightly increased. However, the body pressure distribution near the right shoulder rib is relatively high. Further, the contact area was about 670 to about 900 cm 2 for the comparative example sheet, whereas it was about 930 to about 1340 cm 2 for the test example sheet. From the above, it can be seen that in the test example sheet, even when the lateral direction G enters, the shift in the left-right direction is small.

  FIG. 27 is a test example sheet, when the subject tightens the angle of the seat back part (upright in (a)), slightly loosens (middle in (b)), and further loosens ((c)). The body pressure distribution of the seat back part and the seat cushion part when turning the left curve is shown. From these results, it can be seen that the body pressure distribution near the subject's left shoulder rib, right thigh, and pelvis is high in any posture. In other words, the inertial force when turning the left curve is not shifted in the left-right direction, but it is understood that the body is supported by the right thigh near the left shoulder rib and changed to a rotational motion centered on the spinal column. .

  FIG. 28 shows the vibration absorption characteristics of a test example sheet and a comparative example sheet set on a vibration exciter. In FIG. 28, in addition to the waveform of the input vibration input from the vehicle floor (vibrator in this test example) and the vibration transmissibility of the test example sheet and the comparative example sheet, the product of the present applicant is added to the comparative example sheet. The vibration transmissibility when the drive cushion made of the three-dimensional solid knitted fabric is placed ("reference example sheet") is also shown. As a result, it can be seen that the vibration transmissibility of the test example sheet is significantly reduced after the vicinity of 5 Hz even when compared with the reference example sheet as well as the comparative example sheet. This indicates that the vibration absorption characteristic due to the vertical movement of the back movable pad 290 is high. In the test example sheet, the vibration transmissibility in the vicinity of 4 Hz is higher than that of the comparative example sheet and the reference example sheet, but this is not a problem because it is out of the resonance point of the input vibration.

  FIG. 29 shows a test example sheet in which subjects with body weights of 58 kg, 70 kg, and 100 kg were seated and applied with the same input vibration as that shown in FIG. Is. From FIG. 29, it can be seen that, regardless of the weight, a low vibration transmissibility can be achieved similarly to the case of FIG. 28, and there is no significant difference in vibration absorption characteristics depending on the load.

  FIG. 30 is a graph obtained by examining the degree of fatigue when a subject is seated on a test example sheet and a comparative example sheet for 40 minutes in a static state without applying vibration. The sensory evaluation of the subject was also shown along with the degree of fatigue. The degree of fatigue was determined by a method proposed by the present applicant in WO2005 / 039415A1. That is, a method of obtaining a pulse value of a subject as a biological signal, obtaining a power value from the data, calculating an integral value by processing an absolute value of a time series signal of a gradient of the power value, and obtaining the integral value as a fatigue level It is. FIG. 30 shows that the test example sheet has a much lower degree of fatigue of the subject than the comparative example sheet. This is consistent with the sensory evaluation.

  The above description shows the case where the present invention is applied to a vehicle seat such as an automobile. However, the present invention is not limited to this and can be applied to an office chair, a furniture sofa, and the like. In particular, when a configuration in which the cushion base net 170 is looped between the front frame 130 and the rear frame 140 supported by the two front and rear torsion bars 150 and 160 in the seat cushion portion is applied as follows. Available to:

  When the seat cushion portion 20 is formed in this way, as shown in FIG. 23, the surface of the seat cushion portion is substantially horizontal (the position indicated by the solid line) when no person is seated. On the other hand, when a person is seated, as shown in FIG. 22, the upper layer portion 171 and the lower layer portion 172 on the rear side of the cushion base net 170 are in contact with each other, and the gap 173 is eliminated. Since the gap 173 between the upper layer portion 171 and the lower layer portion 172 is substantially maintained, a seating angle is added (θ2). Conventionally, when a seat angle is provided on a sofa or the like, it is necessary to have a cushion configuration with a seat angle from the beginning. However, in the case of a large sofa or the like, it may be used not only to sit down, but also to lie down on the seat cushion portion and to sleep on the back. In that case, it is difficult to maintain a sleeping posture if the sitting angle is on. However, according to the present invention, when lying in the vicinity of the center of the front frame and the rear frame, the cushion base net 170 maintains the stable sleeping posture because the upper layer portion 171 and the lower layer portion 172 are in contact with each other. Will be able to. In other words, if the present invention is applied, a sitting angle necessary for taking a stable sitting posture is set when sitting, while a flat surface without a sitting angle is made when taking a sleeping posture, This can be done without having to do anything.

DESCRIPTION OF SYMBOLS 1 Seat structure 10 Seat cushion part 100 Cushion frame 110,120 Side frame 130 Front part frame 140 Rear part frame 150 1st torsion bar 160 2nd torsion bar 170 Cushion base net 180 Cushion surface layer cushion material 181, 182 Fabric 183 Three-dimensional Three-dimensional knitted fabric 184 Bead foam 20 Seat back portion 200 Back frame 210, 220 Side frame 230 First upper frame 240 Second upper frame 250 Lower frame 251 S spring 252 Pelvic support member 260 Indentation space 270 Back base net 280 For back Fixed pad 290 Back movable pad 291, 292 Shoulder rib support part 300 Back surface cushion material

Claims (23)

A seat structure including a seat back portion and a seat cushion portion,
The seat cushion portion includes a pair of side frames, a front frame provided between front portions of the pair of side frames, and a rear frame provided between rear portions of the pair of side frames,
The front frame is supported by a torsion bar spanned between the front portions of the pair of side frames,
The rear frame is supported by a torsion bar spanned between the rear portions of the pair of side frames,
A seat structure in which a cushion base net is looped around the front frame and the rear frame so as to form a loop with a predetermined gap between an upper layer surface and a lower layer surface. The seat back portion is
A back frame comprising a pair of side frames, an upper frame connecting the upper ends of the pair of side frames, and a lower frame connecting the lower ends of the pair of side frames;
The seat structure according to claim 1, further comprising a back base net disposed so as to cover the pair of side frames of the back frame. The seat back portion further includes
A pair of shoulder rib support portions corresponding to the shoulder ribs of the seated person, the shoulder rib support portions are connected to each other, and are formed in a substantially U shape having a side covering portion extending downward from each shoulder rib support portion. Each side covering portion is disposed along each side frame via the back base net with the upper side facing upward, and at least a part of the side covering portion is moved by the movement of the seated person. The seat structure according to claim 2, further comprising a movable back pad that can exhibit a relative motion with respect to the seat. The seat back portion is formed with a width narrower than that of the back base net, and the back fixing is fixed to the back base net so that the lower portion is positioned at least at a portion corresponding to the pelvis from the pelvis of the seated person. With a pad,
The seat structure according to claim 3, wherein the back movable pad is arranged around the back fixed pad.   The pair of side frames of the back frame is formed of a plate-like member having a predetermined width and length, and the plate-like member is provided so that the width direction thereof is substantially along the front-rear direction. The seat structure according to any one of claims 2 to 4, wherein the edge portion and the rear edge portion are formed in a substantially linear shape.   The seat structure according to any one of claims 2 to 5, wherein the back frame includes a planar spring member that extends in a width direction at a position lower than a central portion in the vertical direction of the pair of side frames.   The pelvis support member further includes a pelvis support member that covers the front surface of the planar spring member, and when the front cover portion is pressed backward, the pelvis support member rotates backward and the planar shape The seat structure according to claim 6, wherein the spring member is deformed.   The seat structure according to claim 7, wherein at least a part of the planar spring member is embedded within a range of a thickness of a front surface covering portion of the pelvis support member.   The seat structure according to claim 7, wherein at least a part of the planar spring member is joined to the back surface of the front covering portion of the pelvis support member.   The seat structure according to any one of claims 7 to 9, wherein the pelvis support member has a structure having a recess formed over a predetermined width.   The seat structure according to claim 10, wherein an interval in a width direction of the concave portion is in a range of 150 to 220 mm.   The seat structure according to any one of claims 9 to 11, wherein the planar spring member is provided with support blocks in the vicinity of both ends, and each support block is joined to the back surface of the front covering portion of the pelvis support member. .   The seat structure according to claim 12, wherein inclined surfaces are provided in the vicinity of both ends in the width direction of the back surface of the front covering portion of the pelvis support member to which the support blocks are joined.   The seat structure according to claim 12 or 13, wherein each of the support blocks is slidably engaged with the back surface of the front covering portion of the pelvis support member in a lateral direction.   The seat structure according to any one of claims 12 to 14, wherein an interval between the support blocks is in a range of 150 to 220 mm.   The planar spring member is provided in a curved shape in which a central portion in the width direction bulges backward in plan view, and is attached so as to be deformed in the width direction when the pelvis support member is pressed backward. The seat structure according to any one of claims 7 to 15.   17. The pelvis support member is formed in a substantially L-shaped cross section, and has a first groove portion in which a connecting rod that is spanned between recliners of a seat back portion is disposed inside a corner portion thereof. The seat structure according to any one of the above.   The pelvic support member is formed in a substantially L-shaped cross section, and an outer surface groove portion located on the rear side of the connecting rod spanned between the recliners of the seat back portion is formed on the outer surface in the vicinity of the corner portion. 17. The seat structure according to any one of claims 7 to 16, wherein a bulging portion that bulges downward is formed at a side portion.   The seat structure according to any one of claims 7 to 18, wherein the pelvic support member is formed of a bead foam.   After the lower end edge of the back base net is hung from the front edge side to the rear edge side of each side frame through the outside, it passes through the inside of each side frame and is pulled out to the front edge side and fixed. The seat structure according to any one of claims 2 to 19.   The cushion base net is formed by looping a single net member between a front frame and a rear frame, the end edges are engaged with each other by an engaging member, and the engaging member is The seat structure according to any one of claims 1 to 20, wherein the seat structure is provided so as to be in contact with the front frame or the rear frame.   The seat structure according to claim 21, wherein the engaging member is a slide fastener.   The seat structure according to any one of claims 1 to 22, wherein the cushion surface layer cushion material provided on the cushion base net is provided without being restrained by the cushion base net.