Seat cushion

Abstract

To provide a seat cushion which is unlikely to be stuffy, is comfortable to sit on, is excellent in durability, and has excellent holding performance by suppressing a trampoline phenomenon.SOLUTION: A seat cushion is configured by using a center cushion formed by respective filament three-dimensional binders, and respective cushion members of a left side cushion placed on the left side of the center cushion and a right side cushion disposed on the right side of the center cushion, and supports a user's buttocks on an upper surface. Repulsive force during compression of the center cushion is smaller than a repulsive force during compression of the left side cushion and the repulsive force during compression of the right side cushion. High density smooth surface layers formed above the respective cushion members are adjacent to each other in a longitudinal direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This invention relates to a seat cushion for vehicles such as automobiles and wheelchairs. [Background technology]

[0002] Seat cushions used in vehicles are required to prevent the body from falling in the direction of centrifugal force when the vehicle turns a corner (hereinafter sometimes referred to as "holding ability"). For example, Patent Document 1 discloses a seat cushion that enhances holding ability by placing a soft cushion in the center of the seat surface and hard cushions on both sides. However, the seat cushion in Patent Document 1 uses urethane foam, which has low breathability, as the cushioning material, which presents problems such as becoming stuffy in hot weather such as summer.

[0003] In recent years, cushioning materials made of three-dimensional filament structures, formed by three-dimensionally fusing together multiple thermoplastic resin filaments, have attracted attention. For example, Patent Document 2 describes a method for manufacturing a three-dimensional filament structure (network structure) with a high-density smooth surface layer. Such three-dimensional filament structures have a high porosity and excellent breathability, which has the advantage of being less prone to stuffiness and easy to wash. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 61-137732 [Patent Document 2] Patent No. 4966438 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Considering the points mentioned above, it is possible to obtain a seat cushion that is less prone to stuffiness by using a three-dimensional filament bond. Furthermore, by providing a high-density smooth surface layer on the surface of the three-dimensional filament bond, the surface becomes smoother, improving seating comfort, and at the same time, the surface of the three-dimensional filament bond becomes stronger, which is expected to improve durability.

[0006] On the other hand, when a three-dimensional filament assembly with a high-density smooth surface layer is used as a seat cushion material to improve breathability and durability, a problem arises where the pressure in the center of the buttocks increases significantly, further reducing the holding ability. The mechanism by which the high-density smooth surface layer further reduces the holding ability will be explained below using Figures 15 and 16.

[0007] Figure 15 is a cross-sectional view of a seat cushion 200 made of a three-dimensional filament assembly with a high-density smooth surface layer on its surface. The seat cushion 200 is a roughly rectangular cushion formed of a three-dimensional filament assembly, and an upper high-density smooth surface layer 200a and a lower high-density smooth surface layer 200b are formed on the upper surface corresponding to the side on which the user sits and the lower surface on the opposite side.

[0008] Figure 16 is a cross-sectional view showing how the seat cushion 200 deforms when a user sits on it and presses against the buttocks B. As schematically shown by arrows F1 to F3, the pressure on the buttocks B from the seat cushion 200 is greatest near the center where the buttocks B sink the deepest (more precisely, the ischial tuberosity) (see arrow F1), and is smaller near the left and right ends where the buttocks B sink only shallowly (see arrow F3).

[0009] As a cause of the pressure difference in the left - right direction as shown by the arrows F1 to F3, it is due to the fact that the filament three - dimensional conjugate is an elastic body, that is, the deeper the indentation, the greater the pressure, and the shallower the indentation, the smaller the pressure. In the filament three - dimensional conjugate provided with a high - density smooth surface layer on the surface, due to the tension T1 of the high - density smooth surface layer, the force that lifts at the central part of the buttocks (more precisely, the ischial part that becomes a downward protrusion) acts strongly, so a phenomenon (hereinafter sometimes referred to as the "trampoline phenomenon") occurs where the pressure received from the seat cushion 200 becomes high in the vicinity of the central part of the buttocks. As a result, the buttocks easily roll left and right with the vicinity of the central part of the buttocks as a fulcrum, and the holding property is significantly reduced.

[0010] In view of the above - mentioned problems, an object of the present invention is to provide a seat cushion that is not stuffy, has good sitting comfort, excellent durability, and suppresses the trampoline phenomenon and also has excellent holding property.

Means for Solving the Problems

[0011] The seat cushion according to the present invention is composed of cushion members of a center cushion formed of a filament three - dimensional conjugate, a left - side cushion disposed on the left side of the center cushion, and a right - side cushion disposed on the right side of the center cushion, and is a seat cushion that supports the user's buttocks on the upper surface. The compression resilience of the center cushion is smaller than the compression resilience of the left - side cushion and the compression resilience of the right - side cushion, and the high - density smooth surface layers formed on the upper parts of the respective cushion members are adjacent to each other in the left - right direction.

[0012] According to this configuration, it is possible to obtain a seat cushion that is less likely to get stuffy, has good sitting comfort, is excellent in durability, suppresses the trampoline phenomenon, and also has excellent holding properties. In the seat cushion, the left-right direction substantially coincides with the direction of the user's hip width. The "high-density smooth surface layer" is a layer from the surface of the filament three-dimensional conjugate to a depth of 0.5 cm, having a higher bulk density than the inside thereof and in which the ends of the filaments (such as the cut ends of the cut filaments) do not protrude outward from the surface.

[0013] More specifically, as the above configuration, the right side surface of the left side cushion may be inclined in a downward direction as it goes to the right and is in surface contact with the left side surface of the center cushion, and the left side surface of the right side cushion may be inclined in a downward direction as it goes to the left and is in surface contact with the right side surface of the center cushion. The "fitting state" means a state in which the tip of the filament protruding from the surface of one filament three-dimensional conjugate penetrates into the interior of the other filament three-dimensional conjugate (a state of entering inside from the surface) among the filament three-dimensional conjugates in surface contact with each other.

[0014] More specifically, as the above configuration, the right side surface of the left side cushion may be inclined in a downward direction as it goes to the left and is in surface contact with the left side surface of the center cushion, and the left side surface of the right side cushion may be inclined in a downward direction as it goes to the right and is in surface contact with the right side surface of the center cushion.

[0015] More specifically, as the above configuration, the density of the high-density smooth surface layer of the center cushion may be smaller than the density of the high-density smooth surface layer of the left side cushion and the density of the high-density smooth surface layer of the right side cushion. The "density of the high-density smooth surface layer" refers to the bulk density in the high-density smooth surface layer.

[0016] More specifically, the above configuration may be such that the left side of the high-density smooth surface layer of the center cushion and the right side of the high-density smooth surface layer of the left side cushion are fixed by fusion, and the right side of the high-density smooth surface layer of the center cushion and the left side of the high-density smooth surface layer of the right side cushion are fixed by fusion.

[0017] More specifically, the above configuration may include a cushion cover with an anti-stretching member attached, wherein each cushion member is housed in the cushion cover and maintains a state of close contact with one another, and the anti-stretching member may be made of a material that is less prone to stretching than the material of the cushion cover and is arranged to surround each cushion member. [Effects of the Invention]

[0018] According to the present invention, the seat cushion is less prone to stuffiness, provides a comfortable seating experience, is highly durable, and also suppresses the trampoline effect, resulting in a seat cushion with excellent support. [Brief explanation of the drawing]

[0019] [Figure 1] This is a perspective view of the seat cushion 1 according to the first embodiment. [Figure 2] This is a cross-sectional view of the seat cushion 1 according to the first embodiment. [Figure 3] This is a cross-sectional view showing how the seat cushion 1 deforms when pressed against the buttocks B. [Figure 4A] This is a schematic diagram of the manufacturing apparatus 100 for three-dimensional filament assembly. [Figure 4B] Figure 4 is a cross-sectional view of the manufacturing apparatus 100 taken along the line A-A'. [Figure 5A] This is an explanatory diagram showing an example of the shape of the lower surface of the nozzle portion 116. [Figure 5B] This is an explanatory diagram showing an example of the shape of the lower surface of the nozzle portion 116. [Figure 6]This is a cross-sectional view of the seat cushion 2 according to the second embodiment. [Figure 7] This is a cross-sectional view showing how the seat cushion 2 deforms when pressed against the buttocks B. [Figure 8] This is a cross-sectional view of the seat cushion 3 according to the third embodiment. [Figure 9] This is a cross-sectional view of the seat cushion 4 according to the fourth embodiment. [Figure 10] This is a cross-sectional view of the seat cushion 5 according to the fifth embodiment. [Figure 11] This is a cross-sectional view of the seat cushion 6 according to the sixth embodiment. [Figure 12] This is a cross-sectional view of the seat cushion 7 according to the seventh embodiment. [Figure 13] This is a cross-sectional view of a seat cushion 8 according to the eighth embodiment and a modified example thereof. [Figure 14] This is a cross-sectional view of a seat cushion 9 according to the ninth embodiment and a modified example thereof. [Figure 15] This is a cross-sectional view of a seat cushion made of a three-dimensional filament assembly with a high-density smooth surface layer on its surface. [Figure 16] Figure 15 is a cross-sectional view showing how the seat cushion is deformed when pressed against by the buttocks. [Modes for carrying out the invention]

[0020] Each embodiment of the present invention will be described below with reference to the drawings. In the following description, the front-to-back, left-to-right, and up-to-down (thickness) directions (directions that are mutually orthogonal) of the seat cushion are as shown in Figure 1, etc. Unless otherwise specified, the cross-section of the seat cushion refers to the cross-section obtained when the seat cushion is cut by an arbitrary plane perpendicular to the front-to-back direction, and the cross-sectional view of the seat cushion refers to the view showing that cross-section. The cross-sectional shape of the seat cushion refers to the shape of the cross-section when viewed from the front (or rear).

[0021] The front-to-back, left-to-right, and up-to-down (thickness) directions (mutually orthogonal directions) of the manufacturing apparatus for the three-dimensional filament assembly are as shown in Figures 4A and 4B. Furthermore, the seat cushion of each embodiment has a basically symmetrical structure with a virtual plane dividing it in half horizontally as the plane of symmetry.

[0022] 1. First Embodiment First, a first embodiment of the present invention will be described. Figure 1 is a perspective view of the seat cushion 1 according to the first embodiment. Figure 2 is a cross-sectional view of the seat cushion 1.

[0023] The seat cushion 1 is composed of a center cushion 11 positioned in the center in the left-right direction, a left side cushion 12 provided in surface contact with the left side of the center cushion 11, and a right side cushion 13 provided in surface contact with the right side of the center cushion 11. The seat cushion 1 as a whole has a roughly rectangular parallelepiped shape, and the upper surface 1a of the seat cushion 1 supports the user's buttocks. The seat cushion 1 is basically used as a seat cushion for vehicles such as automobiles and wheelchairs, and is used so that its left-right direction roughly coincides with the width of the user's buttocks.

[0024] The center cushion 11 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is longer than the lower base, and has high-density smooth surface layers on its upper surface 11a and lower surface 11b. The left side surface 11c of the center cushion 11 is formed to slope downwards (the further to the right you go, the more downward it slopes) when moving to the right at an angle of approximately 45 degrees from a virtual plane perpendicular to the left-right direction (hereinafter sometimes referred to as the "vertical virtual plane"), and the right side surface 11d of the center cushion 11 is formed to slope downwards when moving to the left at an angle of approximately 45 degrees from the vertical virtual plane.

[0025] The left side cushion 12 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is shorter than the lower base, and has high-density smooth surface layers on its upper surface 12a and lower surface 12b. The left side surface 12c of the left side cushion 12 is formed in a planar shape perpendicular to the left-right direction, and the right side surface 12d of the left side cushion 12 is formed to slope downwards when moving to the right at an angle of approximately 45 degrees from the vertical virtual plane.

[0026] The right side cushion 13 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is shorter than the lower base, and has high-density smooth surface layers on its upper surface 13a and lower surface 13b. The left side surface 13c of the right side cushion 13 is formed to slope downward when moving to the left at an angle of approximately 45 degrees from the vertical virtual plane, and the right side surface 13d of the right side cushion 13 is formed in a planar shape perpendicular to the left-right direction.

[0027] The contact surfaces of the center cushion 11 and the left side cushion 12, and the contact surfaces of the center cushion 11 and the right side cushion 13, are in surface contact in an interlocking state. In this application, "interlocking state" refers to a state in which, in two filament three-dimensional assemblies that are in surface contact with each other, the tip of the filament protruding from the surface of one filament three-dimensional assembly is embedded in the interior of the other filament three-dimensional assembly (a state in which it has entered inward from the surface). Because the surface contact is in an interlocking state, the tip of the filament of one filament three-dimensional assembly is more likely to catch on the other filament three-dimensional assembly, slippage at the contact surface is suppressed, and unintended sinking of the buttocks can be prevented.

[0028] Furthermore, in the seat cushion 1, it is preferable to fix the cushion members 11, 12, and 13 so as not to slip, between the left side surface 11c of the center cushion 11 and the right side surface 12d of the left side cushion 12, and between the right side surface 11d of the center cushion 11 and the left side surface 13c of the right side cushion 13, so as not to slip when the seat cushion 1 deforms due to the user sitting on it.

[0029] One possible fixing method is to use a heating element, such as a heating plate or ultrasonic plastic welder, set to a temperature above the melting point of the thermoplastic resin of the three-dimensional filament bond, to fuse the left side of the high-density smooth surface layer of the upper surface 11a of the center cushion 11 with the right side of the high-density smooth surface layer of the upper surface 12a of the left side cushion 12, and the right side of the high-density smooth surface layer of the upper surface 11a of the center cushion 11 with the left side of the high-density smooth surface layer of the upper surface 13a of the right side cushion 13. By fixing each cushion member 11, 12, and 13 in this way, even if the seat cushion 1 deforms due to the load on the buttocks, slippage of each cushion member 11, 12, and 13 becomes less likely, making it possible to obtain stable holding performance and durability.

[0030] In addition to fusing the upper high-density smooth surface layers of each cushion member 11, 12, and 13 together in this manner, the lower high-density smooth surface layers of each cushion member 11, 12, and 13 may also be fused together to achieve a stronger fixation. That is, the left side of the high-density smooth surface layer of the lower surface 11b of the center cushion 11 and the right side of the high-density smooth surface layer of the lower surface 12b of the left side cushion 12, and the right side of the high-density smooth surface layer of the lower surface 11b of the center cushion 11 and the left side of the high-density smooth surface layer of the lower surface 13b of the right side cushion 13 may be fused together.

[0031] Alternatively, another method of fixing them is to house each cushion member 11, 12, and 13 in a cushion cover, thereby maintaining them in close contact with each other. By housing each cushion member 11, 12, and 13 in the cushion cover in a state where they are pressed together from side to side, the cushion members 11, 12, and 13 can be firmly fixed together, making them less likely to shift.

[0032] Furthermore, a cushion cover with an anti-stretching member attached may be used as the cushion cover that houses each of the cushion members 11, 12, and 13. This anti-stretching member should be made of a material that is less prone to stretching than the cushion cover material (for example, a general fabric) (a fabric that is less prone to stretching than the cushion cover fabric, or a resin or metal zipper, etc.) and should be positioned to surround each of the cushion members 11, 12, and 13. For example, the anti-stretching member may be formed in a band shape so as to surround the group of cushion members 11, 12, and 13 when housed in the cushion cover, when viewed from above or in front. By using a cushion cover with such an anti-stretching member attached, it is possible to maintain a more securely tightly fitted state between each of the cushion members 11, 12, and 13, and to make them less prone to shifting.

[0033] Another method to suppress slippage at the contact surface is to heat the ends of the filament 3D assembly and fuse them at the contact surface (fusion of the ends). However, if fusion is performed at the contact surface even outside of the high-density smooth surface layer, the density increases and a plate-like contact surface (boundary after fusion) is formed there, which can reduce the permeability of the contact surface or increase the resilience excessively. On the other hand, if only partial fusion is performed at the contact surface, the contact surface may peel off and become prone to deterioration after long-term use. Therefore, the cushion members 11, 12, and 13 may be integrally molded using the filament 3D assembly manufacturing apparatus 100 described later. This point will be explained in detail later.

[0034] Furthermore, the thickness (vertical dimension) of the seat cushion 1 is preferably 50 mm or more and 200 mm or less. If the thickness is less than 50 mm, it may be difficult to obtain sufficient support, and if the thickness exceeds 200 mm, the seat cushion 1 tends to become bulky.

[0035] The inclination angle of the contact surfaces between the center cushion 11 and the left side cushion 12, and between the center cushion 11 and the right side cushion 13, with respect to the vertical virtual plane is preferably 30 to 60 degrees. If the inclination angle is less than 30 degrees, the holding performance will be improved, but the feeling of pressure from the sides on the buttocks will be stronger, and the allowable range of buttock width will be reduced. On the other hand, if the inclination angle is greater than 60 degrees, the holding performance may be reduced.

[0036] To achieve good holding performance in the seat cushion 1, the compression rebound force of the center cushion 11 is set to be smaller than that of the left side cushion 12 and the right side cushion 13. The specific values ​​of the compression rebound forces of the center cushion 11, left side cushion 12, and right side cushion 13 should be appropriately determined according to the user's weight, the thickness of the seat cushion 1, etc.

[0037] For example, the compression rebound force of the center cushion 11 may be set to 50N or more and 80N or less, and the compression rebound forces of the left side cushion 12 and right side cushion 13 may be set to 100N or more and 300N or less. In order to obtain good holding performance, it is preferable that the compression rebound forces of the left side cushion 12 and the right side cushion 13 be 1.5 times or more and 4 times or less than the compression rebound force of the center cushion 11, and more preferably 2 times or more and 3 times or less.

[0038] In relation to the present invention, the compression rebound force of each cushion member 11, 12, and 13 is measured as follows. First, a loader with a disc-shaped pressure plate with a diameter of 150 mm attached to its tip is placed on the upper surface of the sample to be measured. Then, this loader is lowered at a speed of 0.4167 mm / s to compress the sample in the thickness direction, and the value of the load W (N) applied to the loader is recorded when the compressed thickness (mm) of the sample is 7.5 mm smaller than the initial thickness. This value of load W is taken as the compression rebound force (N).

[0039] In addition, when the upper surface of the measurement sample is narrower than the disk-shaped pressure plate with a diameter of 150 mm or when the upper surface of the measurement sample is not flat, the shape of the pressure plate may be changed so as to fit tightly to the upper surface of the measurement sample without any gaps. In this case, the compression resilience force (N) is calculated as W×S1 / S2, where the measured value (N) is denoted as W, the area (cm 2 ) of a circle with a diameter of 150 mm is denoted as S1, and the horizontal cross-sectional area (cm 2 ) of the pressure plate is denoted as S2.

[0040] As the density of the high-density smooth surface layer on the upper surface 11a of the center cushion 11, the upper surface 12a of the left side cushion 12, and the upper surface 13a of the right side cushion 13, it is preferably 5 g / cm 3 or more and 20 g / cm 3 or less as the average value. When the average value is less than 5 g / cm 3 , the smoothness and strength tend to decrease. On the other hand, when it exceeds 20 g / cm 3 , the surface tension becomes large and there is a risk that the trampoline phenomenon is likely to occur. In this embodiment, the density of the high-density smooth surface layer on the upper side of the center cushion 11 may be set to be smaller than the density of the high-density smooth surface layer on the upper side of the left side cushion 12 and the density of the high-density smooth surface layer on the upper side of the right side cushion 13.

[0041] As the density of the high-density smooth surface layer on the lower surface 11b of the center cushion 11, the lower surface 12b of the left side cushion 12, and the lower surface 13b of the right side cushion 13, there is no particular limitation, but it is preferably 25 g / cm 3 or more and 50 g / cm 3 or less as the average value. When the average value is less than 25 g / cm 3 , it is difficult to obtain sufficient strength. On the other hand, when it exceeds 50 g / cm 3 , there is a risk that the air permeability will decrease.

[0042] In this application, the high-density smooth surface layer refers to a layer extending to a depth of 0.5 cm from the surface of the three-dimensional filament assembly, having a higher bulk density than the inner layer, and where the ends of the filaments (such as the cut ends of severed filaments) do not protrude outward from the surface. The density of the high-density smooth surface layer refers to the bulk density of the high-density smooth surface layer. The density of the high-density smooth surface layer is determined by cutting a sample from the surface to be measured to a thickness of 0.5 cm, and then measuring the weight (g) of the sample and the volume (cm³) of the sample. 3 It is calculated by dividing by the volume (cm³) of the sample being measured. 3 ) is the upper surface area (cm²) of the measurement sample. 2 It can be calculated by multiplying the value by a thickness of 0.5 (cm).

[0043] In this embodiment, the seat cushion 1 has a rectangular parallelepiped shape, but the seat cushion may be made into a different shape, such as by changing the thickness in the front-to-back direction or by providing irregularities on the surface, as long as the effects of the present invention are not impaired.

[0044] Figure 3 is a cross-sectional view showing how the seat cushion 1 deforms when a user sits on it and presses against the buttocks B. As schematically shown by arrows F1 to F3, the pressure on the buttocks B from the seat cushion 1 decreases near the center where the buttocks B sink the deepest (more precisely, the ischial tuberosity) (arrow F1), and increases towards the user near the left and right ends where the buttocks B sink only shallowly (arrow F3).

[0045] The seat cushion 1 is formed from a three-dimensional filament assembly having a high-density smooth surface layer. By reducing the compression rebound force of the center cushion 11 and increasing the compression rebound force of the left and right side cushions 12 and 13, as shown in Figure 3, it becomes possible to prevent the pressure from the seat cushion 1 from becoming too high in the area near the center of the buttocks where it sinks deeply (high compression ratio), while increasing the pressure from the seat cushion 1 in the area near both ends of the buttocks where it sinks only shallowly (low compression ratio).

[0046] At the same time, since each side of the left and right side cushions 12 and 13 that contacts the center cushion 11 is inclined in the left-right direction, the pressure received by the buttocks B from the seat cushion 1 can be gradually increased from the center towards both ends in the left-right direction, thus widening the acceptable range of buttock width for which good hold can be maintained. As a result, a seat cushion 1 is realized that is less prone to stuffiness, comfortable to sit on, highly durable, and provides excellent hold for many users with different buttock widths.

[0047] Figure 4A is a schematic diagram of a manufacturing apparatus 100 for a three-dimensional filament assembly that can be used to manufacture a seat cushion 1. Figure 4B is a cross-sectional view of the manufacturing apparatus 100 shown in Figure 4A, taken along the line A-A'.

[0048] The filament three-dimensional assembly manufacturing apparatus 100 includes a molten filament supply unit 110 that discharges a molten filament group MF consisting of multiple molten filaments with diameters in the range of 0.3 mm to 3 mm vertically downward, and a fusion bonding and forming unit 120 that intertwines the molten filament group MF three-dimensionally, fuses the contact points, and then cools and solidifies them to form a filament three-dimensional assembly.

[0049] The molten filament supply unit 110 includes a pressurized melting unit 111 (extruder) and a filament discharge unit 112 (die). The pressurized melting unit 111 includes a material input unit 113 (hopper), a screw 114, a screw motor 115 for driving the screw 114, a screw heater (not shown), and a plurality of temperature sensors (not shown). Inside, a cylinder 111a is formed for transporting thermoplastic resin or thermoplastic elastomer (hereinafter sometimes collectively referred to as "thermoplastic resin, etc.") supplied from the material input unit 113 while heating and melting it with the screw heater.

[0050] A screw 114 is rotatably housed inside the cylinder 111a. A cylinder outlet 111b is formed at the downstream end of the cylinder 111a for discharging thermoplastic resin or the like toward the filament discharge section 112. The heating temperature of the screw heater is controlled, for example, based on a detection signal from a temperature sensor installed in the molten filament supply section 110.

[0051] The filament discharge section 112 includes a nozzle section 116, a die heater 118, and a plurality of temperature sensors (not shown). Inside, a guide channel 112a is formed to guide the molten thermoplastic resin discharged from the cylinder discharge port 111b to the nozzle section 116.

[0052] The nozzle section 116 is a roughly rectangular metal plate and is located below the filament discharge section 112, which is the downstream end of the guide channel 112a. Figure 5A shows an example of the shape of the lower surface of the nozzle section 116. As shown, multiple nozzle openings 116a for discharging molten filament are formed on the lower surface of the nozzle section 116. For example, the nozzle openings 116a are arranged in a staggered pattern in the front-back, left-right, and right directions, and the distance (pitch) between adjacent nozzle openings 116a is about 5 to 15 mm. In the example shown in Figure 5A, the cross-sectional shape of the nozzle opening 116a is a circle with an inner diameter of 1 mm, and the distance (pitch) between adjacent nozzle openings 116a is 10 mm. However, the specific shape of the nozzle openings 116a is not particularly limited.

[0053] Furthermore, the shape and inner diameter of each nozzle opening 116a, the spacing between adjacent nozzle openings 116a, or the proportion of the lower surface of the nozzle section 116 occupied by the nozzle openings 116a (density of nozzle openings 116a) can be appropriately adjusted according to the specifications of the three-dimensional filament assembly to be manufactured. This makes it possible to change the bulk density of the three-dimensional filament assembly 3DF formed by the manufacturing apparatus 100, or the shape and diameter of the filaments that make it up, and consequently, to adjust the compression repulsion force of the three-dimensional filament assembly 3DF.

[0054] The fusion bonding section 120 includes a cooling water tank 123, an underwater take-up machine (a pair of slat conveyors) 124, a plurality of transport rollers 125a to 125h, and a pair of support plates 121 that regulate the thickness of the three-dimensional filament bond. The support plate 121 is a metal plate having a downward-sloping flat plate-shaped inclined surface 121a and a bent portion including a flat plate-shaped vertical surface 121b that extends vertically downward from the lower end of the inclined surface 121a.

[0055] The receiving plate 121 guides the ends of the molten filament group MF in the thickness direction toward the center using the front and rear inclined surfaces 121a, thereby reducing the front-to-back dimension of the molten filament group MF to the distance between the front and rear vertical surfaces 121b, increasing the density of the ends of the molten filament group MF in the thickness direction while smoothing the surface and forming a high-density smooth surface layer. The density of the high-density smooth surface layer can be adjusted by changing the area of ​​the nozzle opening 116a located vertically above the inclined surface 121a of the receiving plate 121 (the diameter and number of nozzle openings 116a).

[0056] A cooling water supply device 122 is provided near the upper end of the receiving plate 121 to supply cooling water to the receiving plate 121. The cooling water tank 123 is a tank for storing cooling water W. Inside the cooling water tank 123 are an underwater take-up machine 124 and a plurality of conveyor rollers 125a to 125h. The underwater take-up machine 124 and the plurality of conveyor rollers 125a to 125h are driven by a drive motor (not shown), and the compression repulsive force of the filament three-dimensional assembly can be adjusted by changing the speed of the underwater take-up machine 124.

[0057] Examples of thermoplastic resins that can be used as materials for three-dimensional filament assemblies include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon 66, polyvinyl chloride resin, or polystyrene resin, as well as thermoplastic elastomers such as styrene elastomers, PVC elastomers, olefin elastomers, urethane elastomers, polyester elastomers, nitrile elastomers, polyamide elastomers, or fluorine elastomers.

[0058] The thermoplastic resin supplied from the material input section 113 is heated and melted in the cylinder 111a, and is then supplied as molten thermoplastic resin from the cylinder outlet 111b to the guide channel 112a of the filament discharge section 112, for example, by being pushed out by the screw 114. Subsequently, a group of molten filaments MF, consisting of multiple molten filaments, is discharged from each of the multiple nozzle openings 116a of the nozzle section 116 in a downward translational manner.

[0059] The molten filament group MF (multiple filaments made of thermoplastic resin) discharged from the nozzle section 116 has its thickness (front-to-back dimension) adjusted by the receiving plate 121 as described above, and is deflected by the buoyancy of the cooling water W in the cooling water tank 123, causing each molten filament within it to form random loops. These random loops intertwine three-dimensionally with adjacent random loops in a molten state, and in this three-dimensionally intertwined state, a three-dimensional filament assembly 3DF is formed where the contact points of the filaments are fused together.

[0060] The filament 3D assembly 3DF is transported by an underwater take-up machine 124 and multiple transport rollers 125a to 125h, while being cooled by the cooling water W in the cooling water tank 123, and is finally discharged to the outside of the cooling water tank 123. By cutting the filament 3D assembly 3DF, which is discharged in this manner, at appropriate intervals so that the cross-section is a plane perpendicular to the transport direction, intermediate filament 3D assembly bodies (approximately rectangular parallelepiped filament 3D assembly bodies) that can be used to form each cushion member 11, 12, and 13 can be obtained. The filament 3D assembly 3DF used to form the center cushion 11 should be one that is formed to have a smaller rebound force when compressed compared to the filament 3D assembly 3DF used to form the left side cushion 12 and the right side cushion 13.

[0061] The aforementioned intermediate has high-density smooth surface layers formed on both ends of the molten filament group MF in the thickness direction. One of these high-density smooth surface layers can be used as the upper high-density smooth surface layer of each cushion member 11, 12, 13, and the other can be used as the lower high-density smooth surface layer of each cushion member 11, 12, 13. In this case, the distance between the front and rear vertical planes 121b in the manufacturing apparatus 100 should be set to match the thickness of each cushion member 11, 12, 13. For example, each intermediate used to form each cushion member 11, 12, 13 can be cut with a cutter or the like to form the left and right sides of the cushion member, respectively, to obtain each cushion member 11, 12, 13.

[0062] Here, at the cross-section of the three-dimensional filament assembly formed by cutting with a cutter or the like, the ends of numerous filaments protrude outward due to the cutting of the loop shape of the filaments forming the three-dimensional filament assembly. When these cross-sections are brought into surface contact with each other, the aforementioned surface contact in the interlocking state is achieved. Therefore, by forming the left side surface 11c and right side surface 11d of the center cushion 11, the right side surface 12d of the left side cushion 12, and the left side surface 13c of the right side cushion 13 as such cross-sections, it becomes possible to easily achieve surface contact in the interlocking state at the contact surfaces of the center cushion 11 and the left side cushion 12, and at the contact surfaces of the center cushion 11 and the right side cushion 13.

[0063] However, the method of forming each cushion member 11, 12, and 13 is not limited to those described above, and each cushion member 11, 12, and 13 may be formed by other methods. Furthermore, as a method for forming a high-density smooth surface layer on a three-dimensional filament assembly, a method may also be employed in which a high-density smooth surface layer is formed by heating and melting a cut surface formed by cutting with a cutter or the like, while pressing it with a pressing tool or machine.

[0064] Alternatively, the distance between the front and rear vertical planes 121b in the manufacturing apparatus 100 may be set to match the thickness of the seat cushion 1, the left-right direction of the nozzle section 116 may be aligned with the left-right direction of the seat cushion 1, and the density of the nozzle opening 116a may be appropriately set according to the position of each cushion member 11, 12, 13, as shown in the nozzle section 116 illustrated in Figure 5B, thereby integrally molding each cushion member 11, 12, 13 using the manufacturing apparatus 100.

[0065] In the nozzle section 116 illustrated in Figure 5B, in the region corresponding to the position of the center cushion 11 (the region closer to the center in the left-right direction), the density of the nozzle opening 116a is set to be relatively small so that the bulk density of the three-dimensional filament assembly in the center cushion 11 is relatively small. On the other hand, in the regions corresponding to the positions of the left and right side cushions 12 and 13 (the regions closer to both ends in the left-right direction), the density of the nozzle opening 116a is set to be relatively large so that the bulk density of the three-dimensional filament assembly in the left and right side cushions 12 and 13 is relatively large. With a manufacturing apparatus 100 equipped with such a nozzle section 116, each cushion member 11, 12, and 13 can be molded integrally, and the compression rebound force of the left and right side cushions 12 and 13 can be made greater than the compression rebound force of the center cushion 11.

[0066] As described above, the seat cushion 1 is constructed using cushion members: a center cushion 11, a left side cushion 12 positioned to the left of the center cushion 11, and a right side cushion 13 positioned to the right of the center cushion 11, each formed from a three-dimensional filament assembly. The upper surface is configured to support the user's buttocks. The compression rebound force of the center cushion 11 is smaller than that of the left side cushion 12 and the right side cushion 13, and the high-density smooth surface layers formed on the upper parts of each cushion member 11, 12, and 13 are adjacent to each other in the left-right direction.

[0067] As described above, the seat cushion 1 is constructed using cushion members 11, 12, and 13 formed from highly breathable three-dimensional filament bonds, making it less prone to stuffiness compared to, for example, cushions made from urethane foam with low breathability. Furthermore, the seat cushion 1 is comfortable and durable because the high-density smooth surface layers on the upper parts of each cushion member 11, 12, and 13, which are adjacent to each other in the left-right direction, can support the buttocks. Moreover, since the high-density smooth surface layers formed on the upper parts of each cushion member 11, 12, and 13 are adjacent to each other in the left-right direction, any vertical misalignment of the high-density smooth surface layers between adjacent cushion members that would impair seating comfort is minimized.

[0068] Furthermore, by reducing the rebound force of the center cushion 11 when compressed and increasing the rebound force of the left and right side cushions 12 and 13 when compressed, it becomes possible to prevent the pressure on the buttocks from becoming too high in the area near the center of the buttocks where it sinks deeply (high compression ratio), while increasing the pressure from the seat cushion 1 in the area near both ends of the buttocks where it sinks only shallowly (low compression ratio). As a result, the seat cushion 1 is designed to suppress the trampoline effect and provide excellent support.

[0069] Furthermore, in the seat cushion 1, the right side surface 12d of the left side cushion 12 is sloped downward when moving to the right and is in surface contact with the left side surface 11c of the center cushion 11, and the left side surface 13c of the right side cushion 13 is sloped downward when moving to the left and is in surface contact with the right side surface 11d of the center cushion 11.

[0070] Therefore, the pressure on the buttocks from the seat cushion 1 can be gradually increased from the center toward both ends, thus widening the acceptable range of buttock width for which good hold can be maintained. As a result, the seat cushion 1 is a seat cushion with excellent hold for many users with different buttock widths. For example, even when used by a user with narrow buttocks, the left and right side cushions 12 and 13 can be used to support the buttocks, and it is possible to prevent the body from swaying from side to side due to centrifugal force when the vehicle turns a corner, and to prevent loss of hold as much as possible.

[0071] Furthermore, in the seat cushion 1, the right side surface 12d of the left side cushion 12 is in surface contact with the left side surface 11c of the center cushion 11 in an interlocking state, and the left side surface 13c of the right side cushion 13 is in surface contact with the right side surface 11d of the center cushion 11 in an interlocking state. As a result, the seat cushion 1 suppresses slippage at the contact surfaces of each cushion member 11, 12, and 13, making it possible to suppress unintended sinking of the buttocks.

[0072] 2. Second Embodiment Next, a second embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted.

[0073] Figure 6 is a cross-sectional view of the seat cushion 2 according to the second embodiment. The seat cushion 2 is composed of cushion members: a center cushion 21 located in the center in the left-right direction, a left side cushion 22 provided in surface contact with the left side of the center cushion 21, and a right side cushion 23 provided in surface contact with the right side of the center cushion 21. The seat cushion 2 as a whole has a substantially rectangular parallelepiped shape, and the upper surface 2a of the seat cushion 2 supports the user's buttocks.

[0074] The center cushion 21 is formed from a three-dimensional filament assembly with a trapezoidal cross-section, where the upper base is shorter than the lower base, and has high-density smooth surface layers on its upper surface 21a and lower surface 21b. The left side surface 21c of the center cushion 21 is formed to slope downwards when moving to the left at an angle of approximately 30 degrees from the vertical virtual plane. The right side surface 21d of the center cushion 21 is formed to slope downwards when moving to the right at an angle of approximately 30 degrees from the vertical virtual plane.

[0075] The left side cushion 22 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is longer than the lower base, and has high-density smooth surface layers on its upper surface 22a and lower surface 22b. The left side surface 22c of the left side cushion 22 is formed in a planar shape perpendicular to the left-right direction, and the right side surface 22d of the left side cushion 22 is formed to slope downwards when moving to the left at an angle of approximately 30 degrees from the vertical virtual plane.

[0076] The right side cushion 23 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is longer than the lower base, and has high-density smooth surface layers on its upper surface 23a and lower surface 23b. The left side surface 23c of the right side cushion 23 is formed to slope downwards when moving to the right at an angle of approximately 30 degrees from the vertical virtual plane, and the right side surface 23d of the right side cushion 23 is formed in a planar shape perpendicular to the left-right direction.

[0077] The contact surfaces of the center cushion 21 and the left side cushion 22, and the contact surfaces of the center cushion 21 and the right side cushion 23, are in surface contact in a mating state. The thickness of the seat cushion 2 is preferably 80 mm or more and 200 mm or less. If the thickness of the seat cushion 2 is less than 80 mm, it may be difficult to obtain good holding performance, and if the thickness exceeds 200 mm, the seat cushion 2 may become bulky.

[0078] The inclination angle of the contact surfaces between the center cushion 21 and the left side cushion 22, and between the center cushion 21 and the right side cushion 23, with respect to a vertical virtual plane is preferably 20 to 50 degrees. If the inclination angle is less than 20 degrees, the holding ability of the seat cushion 2 decreases, while if the inclination angle is greater than 50 degrees, the holding ability increases, but the pressure on the buttocks from the sides becomes too strong.

[0079] In order to achieve good holding performance in the seat cushion 2, the compression rebound force of the center cushion 21 is set to be smaller than that of the left side cushion 22 and the right side cushion 23. The specific values ​​of the compression rebound forces of the center cushion 21, left side cushion 22, and right side cushion 23 should be appropriately determined according to the user's weight, the thickness of the seat cushion 2, etc.

[0080] For example, the compression rebound force of the center cushion 21 may be set to 50N or more and 80N or less, and the compression rebound forces of the left side cushion 22 and right side cushion 23 may be set to 100N or more and 300N or less. In order to obtain good holding performance, it is preferable that the compression rebound forces of the left side cushion 22 and the right side cushion 23 be 1.5 times or more and 4 times or less than the compression rebound force of the center cushion 21, and more preferably 2 times or more and 3 times or less.

[0081] In the seat cushion 2, the density of the high-density smooth surface layer on the upper side of the center cushion 21 is set to be lower than the density of the high-density smooth surface layer on the upper side of the left side cushion 22 and the high-density smooth surface layer on the upper side of the right side cushion 23. The density of the high-density smooth surface layer on the upper surface 21a of the center cushion 21 is set to an average of 5 g / cm³. 3 And 20g / cm³ or more 3 The following is preferable: 5 g / cm³ 3 If the value is less than 20 g / cm³, smoothness and strength tend to decrease. 3Beyond a certain point, the surface tension increases, making the trampoline effect more likely to occur.

[0082] The density of the high-density smooth surface layer on the upper surface 22a of the left side cushion 22 and the upper surface 23a of the right side cushion 23 is 20 g / cm³ on average. 3 More than 50g / cm³ 3 Preferably, the average value is 20 g / cm³. 3 If it is less than 50g / cm², the holding power tends to decrease, while 50g / cm² 3 Beyond a certain point, the pressure distribution decreases, resulting in a stiff and uncomfortable seating experience.

[0083] There are no particular restrictions on the density of the high-density smooth surface layers of the lower surface 21b of the center cushion 21, the lower surface 22b of the left side cushion 22, and the lower surface 23b of the right side cushion 23, but an average value of 25 g / cm³ is acceptable. 3 More than 50g / cm³ 3 Preferably, the average value is 25 g / cm³. 3 If the value is less than 50 g / cm², it becomes difficult to obtain sufficient strength, while 50 g / cm² is the lower value. 3 Exceeding this limit may reduce breathability.

[0084] In this embodiment, the seat cushion 2 has a rectangular parallelepiped shape, but the seat cushion may be made into a different shape, such as by changing the thickness in the front-to-back direction or by providing irregularities on the surface, as long as the effects of the present invention are not impaired.

[0085] Figure 7 is a cross-sectional view showing how the seat cushion 2 deforms when a user sits on it and presses against the buttocks B. As shown in this figure, the seat cushion 2 supports the buttocks B on the upper surfaces of each cushion member 21, 22, and 23.

[0086] As schematically shown by arrows F1 to F3, the pressure on the buttocks B from the seat cushion 2 decreases near the center where the buttocks B sink the deepest (more precisely, the ischial tuberosity) (see arrow F1), and increases towards the user near the left and right ends where the buttocks B sink only shallowly (see arrow F3).

[0087] As explained above, in the seat cushion 2, the right side surface 22dc of the left side cushion 22 is inclined downward when moving to the left and is in surface contact with the left side surface 21c of the center cushion 21, and the left side surface 23c of the right side cushion 23 is inclined downward when moving to the right and is in surface contact with the right side surface 21d of the center cushion 21.

[0088] In addition to the fact that the compression rebound force of the center cushion 21 is smaller than that of the left side cushion 22 and the right side cushion 23, the contact surfaces of the center cushion 21 and the left side cushion 22 and the right side cushion 23 each slope downwards as they move outward in the left-right direction. As a result, when the user's buttocks load is applied to the seat cushion 2, the upper surfaces of the left and right side cushions 22 and 23 tend to tilt inward, pushing towards the user. Consequently, the trampoline effect can be suppressed without excessively lowering the density of the high-density smooth surface layer on the upper surface of the center cushion 21, thus achieving a balance between hold, durability, and a smooth seating experience.

[0089] Furthermore, as described above, since each contact surface is inclined, it is possible to increase the occupancy rate of the side cushions 22 and 23, which have high compressive rebound force, on the upper surface of the seat cushion 2 that supports the user's buttocks, without excessively reducing the volume of the center cushion 21. As a result, the left and right sides of the user's buttocks are supported by the left and right side cushions 22 and 23, which have high compressive rebound force, making it easier to obtain good support even if the user's buttocks are narrow, and further widening the acceptable range of buttock width for obtaining good support. For example, even when used by a user with narrow buttocks, the left and right side cushions 22 and 23 can be utilized to support the buttocks, and it is possible to prevent the body from swaying from side to side due to centrifugal force when the vehicle turns a corner, and to prevent loss of support as much as possible.

[0090] 3. Third Embodiment Next, a third embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted.

[0091] Figure 8 is a cross-sectional view of the seat cushion 3 according to the third embodiment. The seat cushion 3 comprises a center cushion 31 located in the center in the left-right direction, a left side cushion 32 provided in surface contact with the left side of the center cushion 31 in a mating state, a right side cushion 33 provided in surface contact with the right side of the center cushion 31 in a mating state, and a base cushion 34. The base cushion 34 is positioned below the seat cushion 3 so as to cover the entire underside of the center cushion 31, the left side cushion 32, and the right side cushion 33. The seat cushion 3 as a whole has a substantially rectangular parallelepiped shape and supports the user's buttocks with its upper surface 3a.

[0092] The center cushion 31 is formed from a three-dimensional filament assembly with a trapezoidal cross-section, where the upper base is shorter than the lower base, and has high-density smooth surface layers on its upper surface 31a and lower surface 31b. The left side surface 31c of the center cushion 31 is formed to slope downwards when moving to the left at an angle of approximately 45 degrees from the vertical plane, and the right side surface 31d of the center cushion 31 is formed to slope downwards when moving to the right at an angle of approximately 45 degrees from the vertical plane.

[0093] The left side cushion 32 is formed from a three-dimensional filament assembly with a trapezoidal cross-section, where the upper base is longer than the lower base, and has high-density smooth surface layers on its upper surface 32a and lower surface 32b. The left side surface 32c of the left side cushion 32 is formed in a planar shape perpendicular to the left-right direction, and the right side surface 32d of the left side cushion 32 is formed to slope downwards when moving to the left at an angle of approximately 45 degrees from the vertical plane.

[0094] The right side cushion 33 is formed from a three-dimensional filament assembly with a trapezoidal cross-section, where the upper base is longer than the lower base, and has high-density smooth surface layers on its upper surface 33a and lower surface 33b. The left side surface 33c of the right side cushion 33 is formed to slope downwards when moving to the right at an angle of approximately 45 degrees from the vertical plane, and the right side surface 33d of the right side cushion 33 is formed in a planar shape perpendicular to the left-right direction.

[0095] The base cushion 34 is formed from a roughly rectangular filament three-dimensional assembly and has high-density smooth surface layers on its upper surface 34a and lower surface 34b. The thickness of the seat cushion 3 is preferably 80 mm to 200 mm. If it is less than 80 mm, it is difficult to obtain good holding power, and if it exceeds 200 mm, the seat cushion tends to become bulky.

[0096] For the seat cushion 3 to achieve good holding performance, the compression rebound force of the center cushion 31 must be smaller than the compression rebound forces of the left side cushion 32 and the right side cushion 33. The compression rebound forces of the center cushion 31, the left side cushion 32, the right side cushion 33, and the base cushion 34 should be determined according to the user's weight and the thickness of the seat cushion 3. For example, the compression rebound force of the center cushion 31 should be 50N or more and 80N or less, the compression rebound force of the left side cushion 32 and the right side cushion 33 should be 100N or more and 300N or less, and the compression rebound force of the base cushion 34 should be 100N or more and 200N or less.

[0097] To obtain good holding performance, it is preferable that the compression rebound force of the left side cushion 32 and the compression rebound force of the right side cushion 33 be 1.5 times or more and 4 times or less than the compression rebound force of the center cushion 31, and more preferably 2 times or more and 3 times or less.

[0098] In the seat cushion 3, the density of the high-density smooth surface layer on the upper side of the center cushion 31 is set to be lower than the density of the high-density smooth surface layer on the upper side of the left side cushion 32 and the high-density smooth surface layer on the upper side of the right side cushion 33. The density of the high-density smooth surface layer on the upper surface 31a of the center cushion 31 is set to an average of 5 g / cm³. 3 And 20g / cm³ or more 3 The following is preferable: 5 g / cm³ 3 If the value is less than 20 g / cm³, smoothness and strength tend to decrease. 3 Beyond a certain point, the surface tension increases, making the trampoline effect more likely to occur.

[0099] The density of the high-density smooth surface layer on the upper surface 32a of the left side cushion 32 and the upper surface 33a of the right side cushion 33 is 20 g / cm³ on average. 3 More than 50g / cm³ 3 Preferably, it is 20 g / cm³.3 If it is less than 50g / cm², the holding power tends to decrease. 3 Beyond a certain point, the pressure distribution decreases, resulting in a stiff and uncomfortable seating experience.

[0100] There are no particular restrictions on the density of the high-density smooth surface layers of the lower surface 31b of the center cushion 31, the lower surface 32b of the left side cushion 32, and the lower surface 33b of the right side cushion 33, but an average value of 25 g / cm³ is acceptable. 3 More than 50g / cm³ 3 Preferably, it is 25 g / cm³. 3 If it is less than 50g / cm³, it becomes difficult to obtain sufficient strength. 3 Beyond a certain point, breathability decreases.

[0101] The density of the high-density smooth surface layer on the upper surface 34a of the base cushion 34 is 10 g / cm³ on average. 3 More than 30g / cm³ 3 Preferably, it is 10 g / cm³. 3 As a result, a high-tensile, high-density, smooth surface layer is formed in the middle layer of the seat cushion 3. Therefore, even when localized loads such as knee pressure are applied to the center of the center cushion 31, the trampoline effect can suppress the feeling of bottoming out. 30g / cm 3 Beyond a certain point, the surface tension becomes too high, which tends to make the seat feel hard.

[0102] The thickness of the base cushion 34 is preferably 40 mm or more and 80 mm or less. If it is less than 40 mm, it becomes difficult to suppress the feeling of bottoming out under localized load, and if it exceeds 80 mm, the seating comfort tends to feel hard.

[0103] In this embodiment, the seat cushion 3 has a rectangular parallelepiped shape, but it may be made into a different shape, such as by changing the thickness in the front-to-back direction or by providing irregularities on the surface, as long as the effects of the present invention are not impaired.

[0104] 4. Fourth Embodiment Next, a fourth embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted. The seat cushion of the fourth embodiment has basically the same configuration as the seat cushion of the first embodiment, except that the shape of the contact surfaces between each cushion member is different.

[0105] Figure 9 is a cross-sectional view of the seat cushion 4 according to the fourth embodiment. The seat cushion 4 comprises a center cushion 41 disposed in the center in the left-right direction, a left side cushion 42 provided in surface contact with the left side surface of the center cushion 41 in a mating state, and a right side cushion 43 provided in surface contact with the right side surface of the center cushion 41 in a mating state.

[0106] The center cushion 41 is formed from a three-dimensional filament assembly with a hexagonal cross-sectional shape, and has high-density smooth surface layers on its upper surface 41a and lower surface 41b. The left side 41c and right side 41d of the center cushion 41 each have two inclined surfaces that, as shown in Figure 9, move from the vertical end towards the center and then outward in the left-right direction.

[0107] The left side cushion 42 is formed from a three-dimensional filament assembly with a pentagonal cross-sectional shape, and has high-density smooth surface layers on its upper surface 42a and lower surface 42b. The left side surface 42c of the left side cushion 42 is formed in a planar shape perpendicular to the left-right direction, and the right side surface 42d of the left side cushion 42 is formed in a shape that allows for overall surface contact with the left side surface 41c of the center cushion 41.

[0108] The right side cushion 43 is formed from a three-dimensional filament assembly with a pentagonal cross-sectional shape, and has high-density smooth surface layers on its upper surface 43a and lower surface 43b. The left side surface 43c of the right side cushion 43 is formed in a shape that allows for overall surface contact with the right side surface 41d of the center cushion 41, and the right side surface 43d of the right side cushion 43 is formed in a planar shape perpendicular to the left-right direction.

[0109] 5. Fifth Embodiment Next, a fifth embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted. The seat cushion of the fifth embodiment has basically the same configuration as the seat cushion of the first embodiment, except that the shape of the contact surfaces between each cushion member is different.

[0110] Figure 10 is a cross-sectional view of the seat cushion 5 according to the fifth embodiment. The seat cushion 5 comprises a center cushion 51 disposed in the center in the left-right direction, a left side cushion 52 provided in surface contact with the left side surface of the center cushion 51 in a mating state, and a right side cushion 53 provided in surface contact with the right side surface of the center cushion 51 in a mating state.

[0111] The center cushion 51 is formed from a filamentous three-dimensional assembly with a roughly rectangular cross-sectional shape (however, each side on the left and right is arc-shaped), and has a high-density smooth surface layer on its upper surface 51a and lower surface 51b. The cross-sectional shapes of the left side 51c and right side 51d of the center cushion 51 are formed in an arc shape that bulges outward in the left-right direction.

[0112] The left side cushion 52 is formed from a filamentous three-dimensional assembly with a roughly rectangular cross-sectional shape (however, the right side is arc-shaped), and has high-density smooth surface layers on its upper surface 52a and lower surface 52b. The left side surface 52c of the left side cushion 52 is formed in a planar shape perpendicular to the left-right direction, and the cross-sectional shape of the right side surface 52d of the left side cushion 52 is formed in an arc shape that bulges to the left so that it can make overall surface contact with the left side surface 51c of the center cushion 51.

[0113] The right side cushion 53 is formed from a filamentous three-dimensional assembly with a roughly rectangular cross-sectional shape (however, the left side is arc-shaped), and has a high-density smooth surface layer on its upper surface 53a and lower surface 53b. The cross-sectional shape of the left side surface 53c of the right side cushion 53 is formed as an arc that bulges to the right so that it can make overall surface contact with the right side surface 51d of the center cushion 51, and the right side surface 53d of the right side cushion 53 is formed as a plane perpendicular to the left-right direction.

[0114] 6. Sixth Embodiment Next, a sixth embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted. The seat cushion of the sixth embodiment has basically the same configuration as the seat cushion of the second embodiment, except that it is provided with a plurality of cylindrical cavities h.

[0115] Figure 11 is a cross-sectional view of a seat cushion 6 according to the sixth embodiment. The seat cushion 6 comprises a center cushion 61 disposed in the center in the left-right direction, a left side cushion 62 provided in surface contact with the left side surface of the center cushion 61 in a mating state, and a right side cushion 63 provided in surface contact with the right side surface of the center cushion 61 in a mating state.

[0116] The center cushion 61 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is shorter than the lower base, and has high-density smooth surface layers on its upper surface 61a and lower surface 61b. Inside the center cushion 61, multiple cylindrical cavities h are formed, each extending from the front (knee side) to the back (waist side).

[0117] The left side cushion 62 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is longer than the lower base, and has high-density smooth surface layers on the upper surface 62a and the lower surface 62b. Inside the left side cushion 62, multiple cylindrical cavities h are formed, each extending from the front (knee side) to the back (waist side).

[0118] The right side cushion 63 is formed from a three-dimensional filament assembly with a trapezoidal cross-sectional shape where the upper base is longer than the lower base, and has high-density smooth surface layers on its upper surface 63a and lower surface 63b. Inside the right side cushion 63, multiple cylindrical cavities h are formed, each extending from the front (knee side) to the back (waist side).

[0119] 7. Seventh Embodiment Next, a seventh embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted. The seat cushion of the seventh embodiment has basically the same configuration as the seat cushion of the fourth embodiment, except that a portion of the left and right sides of the center cushion is made into a cavity h.

[0120] Figure 12 is a cross-sectional view of the seat cushion 7 according to the seventh embodiment. The seat cushion 7 comprises a center cushion 71 located in the center in the left-right direction, a left side cushion 72 located to the left of the center cushion 71, and a right side cushion 73 located to the right of the center cushion 71.

[0121] The center cushion 71 is formed from a three-dimensional filament assembly with a rectangular cross-sectional shape, and has high-density smooth surface layers on its upper surface 71a and lower surface 71b. The right side surface 71c and left side surface 71d of the center cushion 71 are formed in a planar shape perpendicular to the left-right direction.

[0122] The left side cushion 72 is formed from a three-dimensional filament assembly with a pentagonal cross-section and has high-density smooth surface layers on its upper surface 72a and lower surface 72b. The left side cushion 72 is formed in a shape equivalent to the left side cushion 42 of the fourth embodiment.

[0123] The right side cushion 73 is formed from a three-dimensional filament assembly with a pentagonal cross-section and has high-density smooth surface layers on its upper surface 73a and lower surface 73b. The right side cushion 73 is formed in a shape equivalent to the right side cushion 43 of the fourth embodiment.

[0124] Furthermore, the high-density smooth surface layers on the upper sides of the left side cushion 72 and the right side cushion 73 are adjacent to the high-density smooth surface layer on the upper side of the center cushion 71 in the left-right direction, and the high-density smooth surface layers on the lower sides of the left side cushion 72 and the right side cushion 73 are adjacent to the high-density smooth surface layer on the lower side of the center cushion 71 in the left-right direction. With this configuration, triangular prism-shaped cavities h are provided on both the left and right sides of the center cushion 71 in the seat cushion 7.

[0125] 8. Eighth Embodiment Next, an eighth embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted.

[0126] Figure 13 shows cross-sectional views of the seat cushion 8 according to the eighth embodiment and its various modifications. Note that, similar to the seat cushion 2 of the second embodiment, each cushion layer of the seat cushion shown in Figure 13 has a high-density smooth surface layer at the top and bottom, but the high-density smooth surface layer is omitted from the display in Figure 13. Also, in Figure 13, "H" indicates a high-rebound cushion made of a three-dimensional filament assembly with relatively high rebound force when compressed, and "S" indicates a low-rebound cushion made of a three-dimensional filament assembly with relatively low rebound force when compressed.

[0127] Figure 13(a) is a cross-sectional view of the seat cushion 8. The seat cushion 8 has a two-layer structure consisting of an upper cushion layer and a lower cushion layer, and the basic configuration of each cushion layer is the same as that of the seat cushion 2 of the second embodiment.

[0128] Figure 13(b) is a cross-sectional view of a modified seat cushion 81, which is a variation of seat cushion 8. Seat cushion 81 has the same configuration as seat cushion 8, except that the shape of the high-rebound cushion and low-rebound cushion in the lower cushion layer is different.

[0129] Figure 13(c) is a cross-sectional view of seat cushion 82, which is another modified example of seat cushion 8. Seat cushion 82 has the same configuration as seat cushion 8 except that the lower cushion layer of seat cushion 8 is inverted vertically.

[0130] Figure 13(d) is a cross-sectional view of seat cushion 83, which is yet another modification of seat cushion 8. Seat cushion 83 has the same configuration as seat cushion 82 except that the shape of the high-rebound cushion and low-rebound cushion in the upper cushion layer is different.

[0131] 9. Ninth Embodiment Next, a ninth embodiment of the present invention will be described. In the following description, emphasis will be placed on explaining matters that differ from the first embodiment, and explanations of matters that are common to the first embodiment may be omitted.

[0132] Figure 14 is a cross-sectional view of the seat cushion 9 according to the ninth embodiment and its various modifications. Note that each cushion layer of each seat cushion shown in Figure 14 has a high-density smooth surface layer on the upper and lower parts, similar to the seat cushion 2 of the second embodiment, but the high-density smooth surface layer is not shown in Figure 14. Also in Figure 14, "H" indicates a high-rebound cushion made of a filament three-dimensional composite with a relatively large rebound force when compressed, and "S" indicates a low-rebound cushion made of a filament three-dimensional composite with a relatively small rebound force when compressed.

[0133] Figure 14(a) is a cross-sectional view of the seat cushion 9. The seat cushion 9 has a three-layer structure consisting of an upper cushion layer, a middle cushion layer, and a lower cushion layer, and the basic configuration of each cushion layer is the same as that of the seat cushion 2 of the second embodiment.

[0134] Figure 14(b) is a cross-sectional view of a modified seat cushion 91, which is a modified version of seat cushion 9. Seat cushion 91 has the same configuration as seat cushion 9, except that the shapes of the high-rebound cushions and low-rebound cushions in the middle cushion layer and the lower cushion layer are different.

[0135] Figure 14(c) is a cross-sectional view of seat cushion 92, which is another modified example of seat cushion 9. Seat cushion 92 has the same configuration as seat cushion 9 except that the top and bottom of the upper cushion layer are reversed.

[0136] Figure 14(d) is a cross-sectional view of seat cushion 93, which is yet another modification of seat cushion 9. Seat cushion 93 has the same configuration as seat cushion 9, except that the upper cushion layer is made up of low-rebound cushion only.

[0137] Figure 14(e) is a cross-sectional view of seat cushion 94, which is yet another modification of seat cushion 9. Seat cushion 93 has the same configuration as seat cushion 9, except that the lower cushion layer is made up of only high-rebound cushioning.

[0138] Figure 14(f) is a cross-sectional view of seat cushion 95, which is yet another modification of seat cushion 9. Seat cushion 93 has the same configuration as seat cushion 9 except that the top and bottom of the lower cushion layer are reversed.

[0139] 10. Others The seat cushions according to each embodiment of the present invention described above are composed of cushion members, each formed from a three-dimensional filament assembly: a center cushion, a left side cushion positioned to the left of the center cushion, and a right side cushion positioned to the right of the center cushion, and support the user's buttocks on their upper surfaces. Furthermore, in these seat cushions, the compression rebound force of the center cushion is smaller than that of the left side cushion and the right side cushion, and the high-density smooth surface layers formed on the upper part of each cushion member are adjacent to each other in the left-right direction. As a result, these seat cushions are less prone to stuffiness, provide a comfortable seating experience, are highly durable, and also suppress the trampoline effect, resulting in excellent holding performance.

[0140] Although embodiments of the present invention have been described above, the configuration of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. In other words, the above embodiments should be considered to be illustrative in all respects and not restrictive. The technical scope of the present invention is indicated not by the above description of embodiments, but by the claims, and should be understood to include all modifications that fall within the meaning and scope equivalent to the claims. [Industrial applicability]

[0141] This invention can be used in seat cushions for various vehicles. [Explanation of symbols]

[0142] 1,2,3,4,5,6,7,8,9 Seat cushion 11,21,31,41,51,61,71 Center cushion 12, 22, 32, 42, 52, 62, 72 Left side cushion 13, 23, 33, 43, 53, 63, 73 Right side cushion 100 Manufacturing equipment 110 Molten filament supply unit 111 Pressurized melting section 111a Cylinder 111b Cylinder outlet 112 Filament discharge section 112a Channel 113 Material input section 114 Screw 115 Screw Motor 116 Nozzle section 116a Nozzle opening 118 Die Heater 120 Fusion joint forming part 121 Receiving plate 121a Slope 121b vertical plane 122 Cooling water supply system 123 Cooling water tank 124 Underwater retriever 125a~125h Conveyor rollers

Claims

1. A seat cushion comprising a center cushion formed from a three-dimensional filament assembly, a left side cushion positioned to the left of the center cushion, and a right side cushion positioned to the right of the center cushion, wherein the upper surface supports the user's buttocks, The rebound force of the center cushion when compressed is smaller than the rebound force of the left side cushion and the rebound force of the right side cushion when compressed. The thickness of the aforementioned seat cushion is 50 mm or more and 200 mm or less. The right side of the left side cushion is sloped downwards as you move to the right, and is in surface contact with the left side of the center cushion. The left side surface of the aforementioned right side cushion is sloped downwards when moving to the left, and is in surface contact with the right side surface of the aforementioned center cushion. The inclination angle of the contact surfaces between the center cushion and the left side cushion, and between the center cushion and the right side cushion, with respect to a virtual plane perpendicular to the left-right direction, is between 30 and 60 degrees. A seat cushion characterized in that the high-density smooth surface layers formed on the upper part of each cushion member are adjacent to each other in the left-right direction.

2. A seat cushion comprising cushion members, each formed from a three-dimensional filament assembly, a left side cushion positioned to the left of the center cushion, and a right side cushion positioned to the right of the center cushion, wherein the upper surface supports the buttocks of the user, The rebound force of the center cushion when compressed is smaller than the rebound force of the left side cushion and the rebound force of the right side cushion when compressed. The thickness of the aforementioned seat cushion is 80 mm or more and 200 mm or less. The right side of the left side cushion is sloped downwards when moving to the left, and is in surface contact with the left side of the center cushion. The left side surface of the aforementioned right side cushion is inclined downwards as one moves to the right, and is in surface contact with the right side surface of the aforementioned center cushion. The inclination angle of the contact surfaces between the center cushion and the left side cushion, and between the center cushion and the right side cushion, with respect to a virtual plane perpendicular to the left-right direction is between 20 and 50 degrees. A seat cushion characterized in that the high-density smooth surface layers formed on the upper part of each cushion member are adjacent to each other in the left-right direction.

3. The seat cushion according to claim 1 or 2, characterized in that the contact surfaces of the center cushion and the left side cushion, and the contact surfaces of the center cushion and the right side cushion are in surface contact in an interlocking state.

4. Having a cushion cover with an extension prevention member attached, Each of the cushion members is housed in the cushion cover, thereby maintaining a state of close contact with one another. The aforementioned extension prevention member is, The seat cushion according to claim 1 or 2, characterized in that it is made of a material that is less stretchable than the material of the cushion cover and is arranged to surround each of the cushion members.

5. The right side surface of the left side cushion is in surface contact with the left side surface of the center cushion in a state of interlocking, and the left side surface of the high-density smooth surface layer of the center cushion and the right side surface of the high-density smooth surface layer of the left side cushion are fixed by fusion, The seat cushion according to claim 1 or 2, characterized in that the left side surface of the right side cushion is in surface contact with the right side surface of the center cushion in an interlocking state, and the right side surface of the high-density smooth surface layer of the center cushion and the left side surface of the high-density smooth surface layer of the right side cushion are fixed by fusion.

6. A high-density smooth surface layer is also formed on the lower part of each cushion member, The left side of the high-density smooth surface layer at the bottom of the center cushion and the right side of the high-density smooth surface layer at the bottom of the left side cushion are fixed by fusion bonding. The seat cushion according to claim 5, characterized in that the right side of the high-density smooth surface layer at the bottom of the center cushion and the left side of the high-density smooth surface layer at the bottom of the right side cushion are fixed by fusion bonding.

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