Cushion body for vehicle seat

Abstract

To provide a cushion body for a vehicle seat which has good cushioning feeling and has good surface feel at low costs.SOLUTION: A cushion pad 10 which is a cushion body of an automobile seat 1 has a main part 11 which is a nearly flat part in a center part in a seat width direction that is a three-layer structure where a surface layer 17, an intermediate layer 16, and a rear surface layer 15, all made of foamed resin, are arranged from a side near a seating surface. The rear surface layer 15 is formed by foam molding using a molding mold. The surface layer 17 and the intermediate layer 16 are slab-like foamed resin. Hardness of the respective layers decreases from the intermediate layer 16, the rear surface layer 15, and the surface layer 17 in this order; and the thickness of the respective layers decreases from the rear surface layer 15, the surface layer 17, and the intermediate layer 16 in this order.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a cushion body for a vehicle seat, and more particularly to a cushion body for a vehicle seat having a multi-layer structure. [Background technology]

[0002] Conventionally, in vehicle seats installed in vehicles such as automobiles, cushions with a multi-layer structure are sometimes used to support the weight of a seated occupant while maintaining a soft feel at the contact area. In the seat cushion described in Patent Document 1, a cloth material is interposed as an intermediate layer between a high-hardness resin foam and a low-hardness resin foam to prevent bottoming out, settling, etc., and to maintain durability while providing seat performance such as body pressure / load distribution, stroke feeling, springiness, and touch feeling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-142571 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the seat cushion described in the above-mentioned Patent Document 1, the fabric material of the intermediate layer is less stretchable in the in-plane direction than the resin foam, so there is a risk of localized high seat pressure and uncomfortable sitting. In addition, two foaming resin moldings are required to integrate the fabric material of the intermediate layer with the high hardness resin foam and the low hardness resin foam, respectively, which increases the number of molds required and tends to lead to high costs.

[0005] In view of the above problems, an object of the present invention is to provide a cushion body for a vehicle seat which provides a good cushioning feeling and a pleasant surface feel at low cost. [Means for solving the problem]

[0006] The first invention of the present invention is a cushion body for a vehicle seat, characterized in that a main part, which is a substantially flat part in the center of the seat width direction, has a three-layer structure consisting of a surface layer, an intermediate layer, and a back layer, all of which are made of foamed resin, arranged from the side closest to the seating surface, and the back layer is formed by foam molding using a molding die, the surface layer and the intermediate layer are slab-shaped foamed resin, the hardness of each layer increases in the order of the intermediate layer, the back layer, and the surface layer, and the thickness of each layer increases in the order of the back layer, the surface layer, and the intermediate layer.

[0007] According to the first invention, the cushion body of the vehicle seat has a three-layer structure made of foamed resin, so that the in-plane stretch of each layer is not significantly different, and the risk of localized high seat pressure causing discomfort in the seat can be suppressed. In addition, since the three-layer structure is the main part, which is a substantially flat part in the center of the seat width direction, the slab-like intermediate layer and surface layer can be integrated by adhesion with the back layer foamed by a molding die, and the number of molding dies required can be reduced, thereby suppressing high costs.

[0008] The second invention of the present invention is characterized in that, in the above-mentioned first invention, the cushion body is a back pad applied to a seat back, and a first portion of the intermediate layer corresponding to the waist of a seated occupant has a higher hardness than a second portion which is the other portion.

[0009] According to the second invention, the back pad has an intermediate layer in which a first portion corresponding to the lumbar region of the seated occupant is formed to have a higher hardness than the second portion which is the other portion, so that the lumbar region of the seated occupant can be supported more strongly than other portions such as the back.

[0010] The third invention of the present invention is characterized in that, in the above-mentioned second invention, the connecting portion between the first part and the second part is a surface that is inclined with respect to the thickness direction, or a surface in which lines that bend at equal intervals when viewed in the thickness direction extend in the thickness direction.

[0011] According to the third aspect of the present invention, the connecting portion between the first and second portions is formed as a surface that is inclined with respect to the thickness direction, or as a surface that has lines that bend at equal intervals when viewed in the thickness direction, so that a sudden change in hardness can be prevented, thereby enabling the seated occupant's lower back to be supported without feeling uncomfortable. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view of an automobile seat to which a cushion body according to an embodiment of the present invention is applied; [Diagram 2] FIG. 2 is a plan view of a cushion pad of the automobile seat according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2. [Figure 4] 4 is a cross-sectional view taken along the line IV-IV of FIG. 2. [Diagram 5] FIG. 2 is a front view of a back pad of the automobile seat according to the embodiment. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI of FIG. 5. [Figure 7] 7 is a cross-sectional view taken along the line VII-VII of FIG. 5. [Figure 8] 13 is a modified intermediate layer of the back pad. [Figure 9] 13 is a modified intermediate layer of the back pad. [Figure 10] 13 is a modified intermediate layer of the back pad. [Figure 11] 13 is a modified intermediate layer of the back pad. [Figure 12] 13 is a modified intermediate layer of the back pad. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A cushion pad 10 and a back pad 20 applied to an automobile seat 1 according to one embodiment of the present invention will be described with reference to Figs. 1 to 7. In the following description, the directions will be described based on the up-down, front-back, left-right directions shown in each drawing. Here, the up-down, front-back, left-right directions are defined based on the automobile seat 1 when the automobile seat 1 is attached to an automobile floor F. Here, the automobile seat 1 corresponds to the "vehicle seat" in the claims. Also, the cushion pad 10 and the back pad 20 each correspond to the "cushion body" in the claims.

[0014] As shown in FIG. 1, an automobile seat 1 has a seat cushion 2 that supports the buttocks and thighs of a seated occupant, a seat back 3 that supports the waist and back of the seated occupant, and a headrest 4 that supports the head of the seated occupant. The seat cushion 2 has a cushion frame 2F that forms a skeleton, a cushion pad 10 that is a cushion material that is placed on the cushion frame 2F, and a cushion cover 2C that is a skin material that covers the cushion pad 10. The cushion pad 10 is an elastic body formed of urethane foam resin, and its outer shape determines the outer shape of the seat cushion 2. The seat back 3 has a back frame 3F that forms a skeleton, a back pad 20 that is a cushion material that is placed on the back frame 3F, and a back cover 3C that is a skin material that covers the back pad 20. The back pad 20 is an elastic body formed of urethane foam resin, and its outer shape determines the outer shape of the seat back 3.

[0015] As shown in Figs. 2 to 4, the cushion pad 10 has a main part 11 in the center in the left-right direction, and a pair of left and right side parts 12 located on the left and right sides of the main part 11. The main part 11 has an upper surface S1 on the seating side formed in a substantially flat shape in the horizontal direction, and is a part that supports the thighs and buttocks of a seated occupant from below. The pair of left and right side parts 12 has an upper surface S2 formed in a shape that protrudes upward from the upper surface S1 of the main part 11, and is a part that supports the thighs and buttocks of a seated occupant from the sides. A pair of left and right vertical grooves 13 that open upward and extend substantially in the front-rear direction are formed between the main part 11 and the pair of left and right side parts 12. In addition, a horizontal groove 14 that opens upward and extends in the left-right direction is formed slightly rearward from the center of the main part 11 in the front-rear direction. In the main portion 11 and the pair of left and right side portions 12, the surfaces opposite to the upper surface S1 and the upper surface S2 are formed as a lower surface S3 which is a surface corresponding to the upper surface of the cushion frame 2F.

[0016] As shown in FIG. 2 and FIG. 3, the main part 11 has a three-layer structure in which the back layer 15, the intermediate layer 16, and the surface layer 17 are arranged from the bottom. The pair of left and right side parts 12 has a one-layer structure formed only of the back layer 15. The back layer 15 has the upper surface S2 of the pair of left and right side parts 12, the back layer main part upper surface S4 which is the upper surface of the main part 11, and the lower surface S3. The back layer 15 is formed by foaming urethane resin using an upper mold (not shown) whose cavity surface shape corresponds to the upper surface S2 and the back layer main part upper surface S4, and a lower mold (not shown) whose cavity surface shape corresponds to the lower surface S3. The intermediate layer 16 is formed by cutting out a slab-shaped urethane foam resin so as to fit the shape of the back layer main part upper surface S4. The surface layer 17 is formed by cutting out a slab-shaped urethane foam resin so as to fit the shape of the intermediate layer 16. The hardness of the back surface layer 15, intermediate layer 16, and surface layer 17 is the highest, followed by the back surface layer 15 and the surface layer 17. The thickness of the back surface layer 15, intermediate layer 16, and surface layer 17 is the highest, followed by the surface layer 17 and intermediate layer 16.

[0017] After the back surface layer 15 is foam-molded, the intermediate layer 16 is attached to the upper surface S4 of the back surface layer main portion by adhesion and integrated. Next, the surface layer 17 is attached to the intermediate layer 16 attached to the back surface layer 15 by adhesion and integrated. At this time, as shown by the two-dot chain line in Fig. 3, a front protrusion 18 is formed at the upper front end of the cushion pad 10, and a rear protrusion 19 is formed at the upper rear end. When the cushion cover 2C is placed on the upper surface of the cushion pad 10, the front protrusion 18 and the rear protrusion 19 are compressed and deformed by the cushion cover 2C and take the shape shown by the solid line.

[0018] In the cushion pad 10 thus formed, the back layer 15, the intermediate layer 16, and the surface layer 17 are all made of urethane foam resin, and the stretch in the in-plane direction of each layer is not significantly different. This reduces the risk of localized high seat pressure and uncomfortable sitting comfort compared to when the intermediate layer is made of a material such as fabric that has significantly low stretch in the in-plane direction. In addition, since the three-layer structure is the main part 11, which is a substantially flat part in the center of the seat width direction, the slab-like intermediate layer 16 and the surface layer 17 can be integrated by adhesion with the back layer 15 foamed by a mold, reducing the number of molds required, thereby suppressing high costs.

[0019] As shown in Figs. 5 to 7, the back pad 20 has a main part 21 in the left-right center and a pair of left and right side parts 22 located on the left and right sides of the main part 21. The main part 21 has a front surface S5 on the seating surface side formed in a substantially flat shape in a direction perpendicular to the horizontal direction, and is a part that supports the waist and back of a seated occupant from behind. The pair of left and right side parts 22 has a front surface S6 formed in a shape that protrudes forward from the front surface S5 of the main part 21, and is a part that supports the waist and back of a seated occupant from the sides. A pair of left and right vertical grooves 23 that open forward and extend substantially in the front-rear direction are formed between the main part 21 and the pair of left and right side parts 22. In addition, a horizontal groove 24 that opens forward and extends in the left-right direction is formed slightly below the center of the main part 21 in the up-down direction. In the main portion 21 and the pair of left and right side portions 22, the surfaces opposite to the front surface S5 and the front surface S6 are formed as a rear surface S7 which corresponds to the front surface of the back frame 3F.

[0020] As shown in FIG. 6 and FIG. 7, the main part 21 has a three-layer structure in which the back layer 25, the intermediate layer 26, and the surface layer 27 are arranged from the bottom. The pair of left and right side parts 22 has a one-layer structure formed only of the back layer 25. The back layer 25 has a front surface S6 of the pair of left and right side parts 22, a back layer main part front surface S8 which is the front surface of the main part 21, and a rear surface S7. The back layer 25 is formed by foaming urethane resin using an upper mold (not shown) whose cavity surface shape corresponds to the front surface S6 and the back layer main part front surface S8, and a lower mold (not shown) whose cavity surface shape corresponds to the rear surface S7. The intermediate layer 26 is formed by cutting out a slab-shaped urethane foam resin so as to fit the shape of the back layer main part front surface S8. The surface layer 27 is formed by cutting out a slab-shaped urethane foam resin so as to fit the shape of the intermediate layer 26. The hardness of the back layer 25, the intermediate layer 26, and the surface layer 27 is the highest, followed by the back layer 25 and the surface layer 27. The thickness of the back layer 25, the intermediate layer 26, and the surface layer 27 is the highest, followed by the surface layer 27 and the intermediate layer 26.

[0021] After foam molding the back layer 25, the intermediate layer 26 is attached to the front surface S8 of the back layer main part by adhesive bonding, and integrated. Next, the surface layer 27 is attached to the intermediate layer 26 attached to the back layer 25 by adhesive bonding, and integrated. At this time, as shown by the two-dot chain line in Fig. 6, an upper protrusion 28 is formed at the front upper end of the back pad 20, and a lower protrusion 29 is formed at the front lower end. When the back cover 3C is placed on the front surface of the back pad 20, the upper protrusion 28 and the lower protrusion 29 are compressed and deformed by the back cover 3C, and take the shape shown by the solid line.

[0022] In the back pad 20 thus formed, the back layer 25, the intermediate layer 26, and the surface layer 27 are all made of urethane foam resin, and the stretch in the in-plane direction of each layer is not significantly different. This can reduce the risk of localized high seat pressure and uncomfortable sitting comfort, compared to when the intermediate layer is made of a material such as fabric that has significantly low stretch in the in-plane direction. In addition, since the three-layer structure is the main part 21, which is a substantially flat part in the center of the seat width direction, the slab-like intermediate layer 26 and the surface layer 27 can be integrated by adhesion with the back layer 25 foamed by a mold, reducing the number of molds required, thereby suppressing high costs.

[0023] 8 to 12 show modified examples of the present invention. All of them are modified examples of the intermediate layer 26 in the back pad 20. FIGS. 8 and 9 show an intermediate layer 26a as a first modified example. FIG. 8 is a front view seen from the front, and FIG. 9 is a side view seen from the left and right. In the intermediate layer 26a, a lower part 26a1 corresponding to the lumbar region of the seated occupant and an upper part 26a2 corresponding to the back of the seated occupant are connected by a connecting part 26a3. The lower part 26a1 is set to have a higher hardness than the upper part 26a2. The connecting part 26a3 is set so that the thickness of the lower part 26a1 gradually becomes thinner toward the top, and the thickness of the upper part 26a2 gradually becomes thinner toward the bottom. The parts whose thickness gradually changes are overlapped and bonded together to be integrated. This allows the lumbar region of the seated occupant to be supported more strongly than the back. In addition, the upper portion 26a2 and the lower portion 26a1 are integrated by bonding at the connecting portion 26a3 where the thickness of both portions changes gradually, so that a sudden change in hardness in the vertical direction can be prevented, and the lumbar region of the seated occupant can be supported without discomfort. Here, the lower portion 26a1 and the upper portion 26a2 correspond to the "first portion" and the "second portion" in the claims, respectively.

[0024] FIG. 10 shows the intermediate layer 26b as a second modified example. FIG. 10 is a front view seen from the front. In the intermediate layer 26b, a lower part 26b1 corresponding to the lumbar region of the seated occupant and an upper part 26b2 corresponding to the back of the seated occupant are connected by a connecting part 26b3. The lower part 26b1 is set to have a higher hardness than the upper part 26b2. The connecting part 26b3 is formed as a surface extending in the thickness direction in a triangular wave shape with an equal pitch when viewed from the front, and the lower part 26b1 and the upper part 26b2 are integrated by adhesion on this surface. This allows the lumbar region of the seated occupant to be supported more strongly than the back. In addition, the upper portion 26b2 and the lower portion 26b1 are integrated by bonding at the connecting portion 26b3, which is a surface that extends in the thickness direction in a triangular wave shape with equal pitch when viewed from the front, so that a sudden change in hardness in the vertical direction can be prevented and the lumbar region of the seated occupant can be supported without discomfort. Here, the lower portion 26b1 and the upper portion 26b2 correspond to the "first portion" and the "second portion" in the claims, respectively.

[0025] FIG. 11 shows the intermediate layer 26c as a third modified example. FIG. 11 is a front view seen from the front. In the intermediate layer 26c, a lower part 26c1 corresponding to the lumbar region of the seated occupant and an upper part 26c2 corresponding to the back of the seated occupant are connected by a connecting part 26c3. The lower part 26c1 is set to have a higher hardness than the upper part 26c2. The connecting part 26c3 is formed as a surface extending in the thickness direction in a substantially sinusoidal shape with an equal pitch when seen from the front, and the lower part 26c1 and the upper part 26c2 are integrated by adhesion on this surface. This allows the lumbar region of the seated occupant to be supported more strongly than the back. In addition, the upper portion 26c2 and the lower portion 26c1 are joined by bonding at the connecting portion 26c3 in a generally sinusoidal shape with equal pitch when viewed from the front, so that a sudden change in hardness in the vertical direction can be prevented, and the lumbar region of the seated occupant can be supported without discomfort. Here, the lower portion 26c1 and the upper portion 26c2 correspond to the "first portion" and the "second portion" in the claims, respectively.

[0026] FIG. 12 shows an intermediate layer 26d as a fourth modified example. FIG. 12 is a front view seen from the front. In the intermediate layer 26d, a lower portion 26d1 corresponding to the lumbar region of the seated occupant and an upper portion 26d2 corresponding to the back of the seated occupant are connected by a connecting portion 26d3. The lower portion 26d1 is set to have a higher hardness than the upper portion 26d2. The connecting portion 26d3 is formed as a surface extending in the thickness direction in a rectangular wave shape with an equal pitch when viewed from the front, and the lower portion 26d1 and the upper portion 26d2 are integrated by adhesion on this surface. This allows the lumbar region of the seated occupant to be supported more strongly than the back. In addition, the upper portion 26d2 and the lower portion 26d1 are joined by bonding at the connecting portion 26d3 in a rectangular wave shape with equal pitch when viewed from the front, so that a sudden change in hardness in the vertical direction can be prevented, and the lumbar region of the seated occupant can be supported without discomfort. Here, the lower portion 26d1 and the upper portion 26d2 correspond to the "first portion" and the "second portion" in the claims, respectively.

[0027] Although specific embodiments have been described above, the present invention is not limited to those external appearances and configurations, and various modifications, additions, and deletions are possible without departing from the spirit of the present invention. For example, the following can be mentioned.

[0028] 1. In the above embodiment, the modified example is applied to the back pad 20, but it can also be applied to the cushion pad 10. For example, the hardness of the portion of the intermediate layer 16 corresponding to the buttocks of the seated occupant and the portion corresponding to the thighs of the seated occupant may be changed, and the portion corresponding to the buttocks may be made harder than the portion corresponding to the thighs. Any of the first to fourth modified examples is adopted for the connecting portion.

[0029] 2. In the above embodiment, intermediate layer 16 is thinner than surface layer 17, and intermediate layer 26 is thinner than surface layer 27. However, this is not limited thereto, and intermediate layer 16 and surface layer 17 may have the same thickness, or intermediate layer 26 and surface layer 27 may have the same thickness.

[0030] 3. In the above embodiment, the present invention is applied to an automobile seat 1, but it may also be applied to seats for airplanes, ships, railway cars, etc. [Explanation of symbols]

[0031] 1. Car seats (vehicle seats) 2 Seat cushion 3 Seat back 10 Cushion pad (cushion body) 11 Main Section 12 Side section 15 Back layer 16 Middle Class 17 Surface layer 20 Back pad (cushion body) 21 Main Section 22 Side section 25 Back layer 26 Middle Class 26a middle class 26a1 Lower part (first part) 26a2 Upper part (second part) 26a3 Connecting part 26b Middle class 26b1 Lower part (first part) 26b2 Upper part (second part) 26b3 Connecting part 26c middle class 26c1 Lower part (1st part) 26c2 Upper part (second part) 26c3 Connecting part 26d middle class 26d1 Lower part (first part) 26d2 Upper part (second part) 26d3 Connection 27 Surface layer

Claims

1. A cushion body for a vehicle seat, comprising: The main portion, which is a substantially flat portion in the center of the seat width direction, has a three-layer structure including a surface layer, an intermediate layer, and a back layer, all of which are made of foamed resin, from the side closest to the seating surface. The back surface layer is formed by foam molding using a molding die, the surface layer and the intermediate layer are slab-shaped foamed resins, The hardness of each layer is, in order, harder than the intermediate layer, the back surface layer, and the front surface layer. The thickness of each layer of the cushion body for a vehicle seat is formed in the order of thickness of the back layer, the front layer, and the intermediate layer.

2. In claim 1, The cushion body is a back pad applied to a seat back, The cushion body for a vehicle seat has a first portion of the intermediate layer corresponding to the lumbar region of a seated occupant, the first portion having a higher hardness than a second portion which is the remaining portion.

3. In claim 2, A cushion body for a vehicle seat, wherein the connecting portion between the first portion and the second portion is a surface that is inclined with respect to the thickness direction, or a surface on which lines that bend at equal intervals when viewed in the thickness direction extend in the thickness direction.

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