Vehicle seat

Abstract

To improve occupant's seating feeling in a seat having hardness that partially varies.SOLUTION: A vehicle seat S includes: a seat frame Sa; a S spring 23a which is installed on the seat frame Sa and receives a load of an occupant; and a seat back pad 2a having multiple areas respectively formed by different materials and disposed between a skin material of the seat and the S spring 23a. The S spring 23a is disposed at a position facing a border part 41 of the multiple areas formed by the different materials which is included in the seat back pad 2a.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a vehicle seat provided with a seat pad having partially different hardnesses.

Background Art

[0002] A vehicle seat is known in which the hardness of the seat pad is made different according to the portion that supports the occupant. For example, Patent Document 1 below discloses a vehicle seat in which a side support portion is formed of foams having different hardnesses inside and outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the change in hardness is large at the boundary portion between different foams in the seat pad, a sense of discomfort may be caused at the boundary portion, and the seating feeling of the seat may be impaired.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a vehicle seat capable of improving the seating feeling of an occupant in a seat having partially different hardnesses.

Means for Solving the Problems

[0006] The above problems are According to the vehicle seat of the present invention, a seat back forming the skeleton of the backrest surface solved by In the seat width direction with respect to the seat back frame a frame, Covering the seat back a pressure receiving member installed on the frame and receiving the load of the occupant, and having a plurality of regions made of different materials, Back a seat pad disposed between the skin material and the pressure receiving member, The seat back pad includes an upper cushion region that supports the upper part of the occupant's upper body, a right side cushion region that supports the right side part of the occupant's upper body, and a left side cushion region that supports the left side part of the occupant's upper body, which are separated by groove portions. The front end and the rear end of the boundary portion of the plurality of regions made of different materials are at the same position in the seat vertical direction. The boundary portion is provided along the seat width direction and is located above the lumbar support region that supports the occupant's lumbar spine in the seat vertical direction. A second groove is provided in front of the boundary portion and

[0007] According to the above vehicle seat, at the boundary of the region made of different materials in the seat pad Since a groove (second groove) is provided in front of it, the occupant does not come into contact with the boundary portion the discomfort of the occupant at the boundary can be reduced. Thereby, the seating comfort of the occupant in the seat with partially changed hardness can be improved.

[0008] Also, in the above vehicle seat, The seat back frame includes an upper frame formed in an inverted U shape on the upper side, left and right side frames connected to and disposed on the left and right sides of the upper frame, and a lower frame installed at the lower end of the inner surface of the side frame. The boundary portion is located between the side frames in the seat width direction it may be 。

[0009] Also, in the above vehicle seat, The boundary portion and the portion of the groove provided along the seat width direction are arranged side by side in the seat vertical direction it may be 。

[0010] Also, in the above vehicle seat, The seat back pad has a lower cushion region surrounded by the groove at least on three sides in an inverted U shape, and the boundary portion is provided in the lower cushion region it may be 。

[0011] Also, in the above vehicle seat, A recess is formed on the side of the lower end of the seat back pad, where the width of the seat back pad is smaller than that of the boundary portion at a position lower than the boundary portion it may be 。

[0012] Also, in the above vehicle seat, A seat cushion frame forming the skeleton of a seat cushion, which is a seating portion that supports the occupant from below, and a reclining mechanism provided between the seat cushion frame and the seat back frame to rotatably connect the seat back. A seat cushion pad is placed on the seat cushion frame, the seat cushion pad is covered with a cushion skin material, a headrest is arranged on the upper surface side of the seat back, a headrest pad is placed on the pillar of the headrest, the headrest pad is covered with a headrest skin material, and the recess is provided avoiding the reclining mechanism it may be 。

[0013] Also, in the above vehicle seat, The width of the boundary portion in the sheet vertical direction is larger than the width of the second groove portion in the sheet vertical direction, and the boundary portion is provided so as to straddle the second groove portion in the sheet vertical direction. it may be 。

[0014] Also, in the above vehicle seat, In the seat back pad, the hardness of the region below the boundary portion is higher than the hardness of the region above the boundary portion. it may be. By doing so, the lower part of the upper body of the occupant can be stably held, making it easier for the occupant to maintain their posture. Also, by softly holding the upper part of the upper body of the occupant, the riding comfort is improved.

[0015] Also, in the above vehicle seat, the suspension part of the skin material formed at the boundary The second groove portion to The may be attached. By doing so, The skin material can be suspended at the position of the boundary. Thereby, since the sagging of the skin material at the boundary is prevented, the discomfort at the boundary can be reduced.

[0016] Also, in the vehicle seat described above, the boundary portion Made of different materials may be a compatible portion where the materials of the respective plurality of regions are compatible with each other. By doing so, the surface on which the load is input at the boundary portion can be widened. Thereby, the discomfort of the occupant at the boundary portion can be reduced.

Effect of the Invention

[0017] According to the present invention, it is possible to reduce the discomfort of the occupant at the boundary portion between regions made of different materials.

[0018] According to one aspect of the present invention, even when a plurality of regions made of different materials are provided in the seat back pad, it is possible to reduce the discomfort of the occupant at the boundary portion between the regions.

[0019] According to one aspect of the present invention, it is possible to reduce the change in hardness between the boundary portion of the regions made of different materials and its surroundings.

[0020] According to one aspect of the present invention, it is possible to suppress a sudden change in hardness between the boundary portion and its surroundings, and reduce the discomfort at the boundary portion.

[0021] According to one aspect of the present invention, it is possible to make the hardness change between the boundary portion and its surroundings smooth, and reduce the discomfort at the boundary portion.

[0022] According to one aspect of the present invention, it is possible to make the hardness change at the boundary portion smooth and reduce the discomfort.

[0023] According to one aspect of the present invention, it is possible to facilitate the maintenance of the occupant's posture and improve the riding comfort.

[0024] According to one aspect of the present invention, even when a plurality of regions made of different materials are provided in the seat cushion pad, it is possible to reduce the discomfort of the occupant at the boundary portion between the regions.

[0025] According to one aspect of the present invention, sagging of the skin material is prevented at the boundary portion, and the discomfort at the boundary portion can be reduced.

[0026] According to one aspect of the present invention, the surface on which the load is input at the boundary portion is widened, and the discomfort of the occupant at the boundary portion can be reduced.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Modes for Carrying Out the Invention

[0028] Hereinafter, with reference to FIGS. 1 to 14, a vehicle seat S according to an embodiment of the present invention (hereinafter, this embodiment) will be described. Note that the embodiments described below are for facilitating the understanding of the present invention and do not limit the present invention. That is, the present invention can be changed and improved without departing from its gist, and it goes without saying that equivalents thereof are included in the present invention. First, the outline of each figure will be described.

[0029] FIG. 1 is a perspective view of a vehicle seat S according to this embodiment, and FIG. 2 is a perspective view of a seat frame Sa that forms the skeleton of the vehicle seat S.

[0030] FIG. 3 is a front view of a seat back pad 2a that is a cushion material of the seat back 2, FIG. 4 is a cross-sectional view taken along line IV-IV of the seat back pad 2a, and FIG. 5 is a cross-sectional view taken along line V-V of the seat back pad 2a.

[0031] FIG. 6 is a top view of a seat cushion pad 1a that is a cushion material of the seat cushion 1, FIG. 7 is a cross-sectional view taken along line VII-VII of the seat cushion pad 1a, and FIG. 8 is a cross-sectional view taken along line VIII-VIII of the seat cushion pad 1a.

[0032] And FIGS. 9 to 14 are cross-sectional views taken along line V-V of seat back pads 2a according to the first to sixth modified examples, respectively.

[0033] <Configuration of Vehicle Seat S and Seat Frame Sa> First, based on FIGS. 1 and 2, the configuration of a vehicle seat S and a seat frame Sa according to this embodiment will be described.

[0034] As shown in FIG. 1, the vehicle seat S of this embodiment is mainly composed of a seat cushion 1, a seat back 2 disposed on the upper surface side of the seat cushion 1, and a headrest 3 disposed on the upper surface side of the seat back 2, and a seat frame Sa serving as a skeleton shown in FIG. 2 is provided inside the vehicle seat S.

[0035] In the following description, the "front-rear direction" means the front-rear direction as seen from the seat occupant of the vehicle seat S, and coincides with the traveling direction of the vehicle. The "seat width direction" means the lateral width direction of the vehicle seat S, and coincides with the left-right direction as seen from the seat occupant of the vehicle seat S. Further, the "vertical direction" means the height direction of the vehicle seat S, and coincides with the vertical direction when the vehicle seat S is viewed from the front.

[0036] The seat cushion 1 is a seating portion that supports the occupant from below, and is configured by placing a seat cushion pad 1a on a cushion frame 10 serving as a skeleton shown in FIG. 2 and covering the seat cushion pad 1a with a skin 1b.

[0037] The seat back 2 is a backrest portion that supports the occupant's back from behind, and is configured by placing a seat back pad 2a on a seat back frame 20 serving as a skeleton shown in FIG. 2 and covering the seat back pad 2a with a skin 2b.

[0038] The headrest 3 is a head portion that supports the occupant's head from behind, and is configured by placing a headrest pad 3a on a pillar (not shown) serving as a core material and covering the headrest pad 3a with a skin 3b.

[0039] The cushion frame 10 is composed of a substantially rectangular frame serving as a skeleton of the seat cushion 1. As shown in FIG. 2, it includes cushion side frames 11 arranged on the left and right sides, a pan frame 12 as a plate-shaped frame installed on the upper surface of the front side of each cushion side frame 11, a frame connection pipe 13 as a connecting member installed near the rear end of each cushion side frame 11, and S springs 14a and 14b that connect the approximate centers in the front-rear direction of each cushion side frame 11.

[0040] The S springs 14a and 14b are pressure-receiving members that support a passenger sitting on the seat cushion 1 from below. The S spring 14a and the S spring 14b located in front of the S spring 14a in the front of the seat are respectively installed and held on the cushion side frames 11 on both sides.

[0041] The cushion side frame 11 is made of a sheet metal member extending in the front-rear direction. The left cushion side frame 11 and the right cushion side frame 11 are spaced apart in the left-right direction in a parallel state with each other.

[0042] As shown in FIG. 2, a reclining mechanism 15 for rotatably connecting the seat back 2 to the seat cushion 1 is provided between the cushion side frame 11 and the seat back frame 20.

[0043] The reclining mechanism 15 is composed of a known mechanism, and includes a connecting shaft 16 that serves as a rotation axis of the reclining mechanism 15, a spiral spring 17 that biases the seat back frame 20 to an upright state, and a spring locking member 18 that locks the extending end portion of the spiral spring 17.

[0044] The connecting shaft 16 is composed of a pipe member having a substantially circular cross-section that connects the left and right end portions of the cushion side frame 11 and the seat back frame 20.

[0045] The connecting shaft 16 is connected by passing through a shaft through-hole (not shown) provided at the lower end portions on both left and right sides of the seat back frame 20 and a shaft insertion hole (not shown) provided at the rear end portions on both left and right sides of the cushion side frame 11.

[0046] The spiral spring 17 is composed of a spiral-shaped linear member and is provided at the rear end portions of the left and right outer side surfaces of the cushion side frame 11. One end portion of the spiral spring 17 is fixed to the lower end portions on the left and right outer sides of the seat back frame 20 by being hooked to the spring locking member 18, and the other end portion of the spiral spring 17 is hooked and fixed to a spring locking portion (not shown) provided on the left and right outer side surfaces of the cushion side frame 11.

[0047] The spring locking member 18 has a substantially L-shaped configuration formed by bending a sheet metal member. The upper end portion of the spring locking member 18 is fixed to the seat back frame 20, and bent portions 18a bent outward to the left and right are provided at the lower end portion. One end of the spiral spring 17 is hooked to the bent portion 18a to form the structure.

[0048] An operation lever (not shown) is attached to the outside of the cushion side frame 11. By operating this operation lever, the connecting shaft 16 rotates, and a mechanism is formed in which the seat back 2 rotates with respect to the seat cushion 1.

[0049] As shown in FIG. 2, the seat back frame 20 has a substantially rectangular frame body, an upper frame 21 of a hollow cylindrical body formed in a substantially inverted U shape on the upper side, left and right side frames 22 disposed by connecting to the upper frame 21 on the left and right sides, S springs 23a and 23b installed substantially at the center of the inner side surfaces of the respective side frames 22, and a lower frame 30 installed at the lower end portions of the inner side surfaces of the respective side frames 22. Note that the side frame 22 and the lower frame 30 may be integrally formed.

[0050] The left and right side frames 22 have a substantially U-shaped configuration formed by bending a sheet metal member inward to the left and right, extend in the vertical direction, and are spaced apart in the left and right directions in a parallel state. The left and right side frames 22 are formed in a shape that gradually projects forward continuously from the upper side to the lower side, and include a front bent portion 22a bent inward to the left and right from the front end portion and a rear bent portion 22b bent inward to the left and right from the rear end portion.

[0051] On the left and right inner surfaces of the left and right side frames 22, concave portions 22c that are recessed inward on the left and right are provided, and through holes that penetrate in the vertical direction are formed in the concave portions 22c.

[0052] The S-springs 23a and 23b are each pressure-receiving members that support the back and waist of the occupant from behind. In this embodiment, it is assumed that the pressure-receiving members are constituted by metal elastic members, but it is not limited thereto. For example, the pressure-receiving members may be constituted by resin, fabric, etc., and may not be elastically deformed. Further, the S-spring 23a and the S-spring 23b located below the seat relative to the S-spring 23a are each connected to the left and right side frames 22 by inserting and latching the left and right end portions into the through holes of the concave portions 22c.

[0053] The lower frame 30 has a substantially U-shaped configuration in which a sheet metal member is bent forward, and as shown in FIG. 2, is composed of a frame main body portion 31 that extends in the left and right directions and frame bent portions 32 formed by bending the left and right ends.

[0054] The frame bent portion 32 is arranged so as to abut against the inner surface of the side frame 22, and the upper end portion of the frame bent portion 32 and the lower end portion of the side frame 22 are welded and fixed.

[0055] A shaft through hole (not shown) that penetrates in the left and right directions is provided in the frame bent portion 32, and the connecting shaft 16 is connected by passing through the shaft through hole. A spring locking member 18 is fixed to the outer surface of the frame bent portion 32 by a fastening bolt 38.

[0056] As shown in FIG. 2, the frame main body portion 31 includes an upper end flange portion 33a and a lower end flange portion 33b that protrude forward. The upper end flange portion 33a and the lower end flange portion 33b are provided at the upper end portion and the lower end portion of the frame main body portion 31, respectively, and extend in the left and right directions.

[0057] Next, based on FIGS. 3 to 8, the configurations of the seat back pad 2a and the seat cushion pad 1a will be described.

[0058] <Configuration of Seat Back Pad 2a> First, based on FIGS. 3 to 5, the details of the seat back pad 2a will be described. As shown in FIG. 3, the seat back pad 2a includes a lower cushion region 40 that supports the lower part of the occupant's upper body, an upper cushion region 42 that supports the upper part of the occupant's upper body, a right side cushion region 44 that supports the right side part of the occupant's upper body, and a left side cushion region 46 that supports the left side part of the occupant's upper body. Each region is separated by a groove portion 48. Further, a headrest through-hole 52 through which the pillar of the headrest 3 is inserted is formed on the upper surface of the upper cushion region 42. And a suspension wire 54 for suspending the skin 2b on the front side of the seat is embedded in the seat back pad 2a.

[0059] The lower cushion region 40 includes a lower first cushion region 40a and a lower second cushion region 40b that are formed of different materials, and the boundary between the lower first cushion region 40a and the lower second cushion region 40b is defined as a boundary portion 41. Here, the lower first cushion region 40a is located above the lower second cushion region 40b. For example, the lower first cushion region 40a is a lumbar support region that supports the lumbar vertebra of the occupant, and in this case, the boundary portion 41 will be located above the lumbar support region.

[0060] Also, the above-mentioned lower first cushion region 40a and lower second cushion region 40b may be members made of the same raw material formed so that their performances such as hardness, density, and rebound resilience during foam molding are different, or may be members formed of raw materials with different performances such as hardness, density, and rebound resilience during foam molding respectively, or may be three-dimensional network elastic bodies with different structures. For example, the lower first cushion region 40a and the lower second cushion region 40b may be formed of different synthetic resin raw materials among polyurethane (PUR), polystyrene (PS), polyethylene (PE), polypropylene (PP), etc.

[0061] Also, the materials of both the lower first cushion region 40a and the lower second cushion region 40b may be selected such that the hardness of the lower first cushion region 40a is higher than that of the lower second cushion region 40b. As an example in this case, the lower first cushion region 40a may be formed by foaming PP (polypropylene) beads, and the lower second cushion region 40b may be formed by polyurethane foam. In this way, by making the hardness of the lower first cushion region 40a higher than that of the lower second cushion region 40b, the region supporting the lumbar vertebra of the occupant can be made hard, and the region supporting the upper body above the lumbar vertebra of the occupant can be made soft. As a result, it becomes possible to support the occupant's posture to be stable, and since the upper part of the upper body such as around the shoulders of the occupant sinks into the seat, the burden can be reduced and the sitting comfort can be improved.

[0062] Note that the boundary portion 41 between the lower first cushion region 40a and the lower second cushion region 40b is wavy in the example shown in FIG. 3 when viewed from the front of the seat, but is not limited thereto and may be formed into other curved shapes, linear shapes, or composite shapes (for example, broken lines, etc.) composed of a combination of two or more different curves and straight lines.

[0063] Furthermore, the boundary portion 41 between the lower first cushion region 40a and the lower second cushion region 40b may be a joint portion configured by bonding the lower first cushion region 40a and the lower second cushion region 40b after they are respectively formed, or may be an impregnated layer formed by one layer penetrating into the other layer in the formation of the lower second cushion region 40b with respect to the lower first cushion region 40a. Still further, the boundary portion 41 may be a compatible portion in which the molding material of the lower first cushion region 40a and the molding material of the lower second cushion region 40b are mixed and cured.

[0064] Further, as shown in FIGS. 3 to 5, a press felt 50 is bonded to the back surfaces (the surfaces on the rear side of the seat) of the lower first cushion region 40a and the lower second cushion region 40b. The press felt 50 is disposed at a position overlapping the boundary portion 41 in the vertical direction of the seat. Thereby, the strength around the boundary portion 41 can be increased.

[0065] Note that the upper cushion region 42, the right side cushion region 44, and the left side cushion region 46 may be formed of the same material as the lower first cushion region 40a or the lower second cushion region 40b, or may be formed of materials different from both.

[0066] Here, based on FIG. 5, the positional relationship between the boundary portion 41 and the S springs 23a and 23b which are pressure receiving members will be described. As shown in FIG. 5, the boundary portion 41 and the S spring 23a are disposed at positions where at least a part thereof overlaps in the vertical direction of the seat. Here, the front end portion 41a is the end portion on the front side of the seat of the boundary portion 41, and the rear end portion 41b is the end portion on the rear side of the seat of the boundary portion 41. In the example shown in FIG. 5, the front end portion 41a and the rear end portion 41b are at substantially the same position in the vertical direction of the seat, and both the front end portion 41a and the rear end portion 41b are disposed at positions overlapping at least a part of the S spring 23a in the vertical direction of the seat.

[0067] Note that in the example shown in FIG. 5, the boundary portion 41 is disposed at a position overlapping the S spring 23a in the vertical direction of the seat, but the boundary portion 41 may be disposed at a position overlapping the S spring 23b in the vertical direction of the seat. Other configuration examples of the arrangement of the boundary portion 41 and the S springs 23a and 23b will be described later.

[0068] As shown in FIG. 5, since the boundary portion 41 and the S spring 23a are arranged at positions facing each other in the sheet vertical direction, the boundary portion 41 receiving the load of the occupant can be supported by the S spring 23a. And the boundary portion 41 is a portion where the hardness changes from the hardness of the lower first cushion region 40a to the hardness of the lower second cushion region 40b. By being supported by the S spring 23a as described above, the hardness change around the boundary portion 41 can be alleviated.

[0069] <Configuration of the seat cushion pad 1a> Next, based on FIGS. 6 to 8, the details of the seat cushion pad 1a will be described. As shown in FIGS. 6 and 7, the seat cushion pad 1a includes a front cushion region 60 that supports the occupant's thigh, a rear cushion region 62 that supports the occupant's buttocks, a right side cushion region 64 that supports the occupant's right foot, and a left side cushion region 66 that supports the occupant's left foot. Each region is separated by a groove portion 68.

[0070] The front cushion region 60 includes a front first cushion region 60a and a front second cushion region 60b formed of different materials, and the boundary between the front first cushion region 60a and the front second cushion region 60b is defined as a boundary portion 61. Here, the front second cushion region 60b is located in front of the front first cushion region 60a. For example, the front first cushion region 60a is a sciatic tuberosity support region that supports the occupant's sciatic tuberosity. In this case, the boundary portion 61 will be located in front of the sciatic tuberosity support region.

[0071] Further, the above-mentioned front first cushion region 60a and front second cushion region 60b may be members made of the same raw material formed so that their performance such as hardness, density, and rebound elastic modulus during foam molding is different, or may be members formed from raw materials with different performance such as hardness, density, and rebound elastic modulus during foam molding, or may be three-dimensional network elastic bodies with different structures. For example, the front first cushion region 60a and the front second cushion region 60b may be formed from different synthetic resin raw materials among polyurethane (PUR), polystyrene (PS), polyethylene (PE), polypropylene (PP), etc.

[0072] Also, the materials of the front first cushion region 60a and the front second cushion region 60b may be selected so that the hardness of the front first cushion region 60a is higher than that of the front second cushion region 60b. As an example in this case, the front first cushion region 60a may be formed by foaming PP (polypropylene) beads, and the front second cushion region 60b may be formed of polyurethane foam. In this way, by making the hardness of the front first cushion region 60a higher than that of the front second cushion region 60b, the region supporting the occupant's ischial tuberosity can be made hard, and the region supporting the front of the occupant's ischial tuberosity can be made soft. As a result, it becomes possible to support the occupant's posture stably, and since the front of the occupant's thigh sinks into the seat, the burden is reduced and the sitting comfort can be improved.

[0073] Note that the boundary portion 61 between the front first cushion region 60a and the front second cushion region 60b is wavy in the example shown in FIG. 6 when viewed from above the seat surface, but is not limited thereto and may be formed into other curved shapes, linear shapes, or composite shapes (for example, broken lines, etc.) composed of a combination of two or more different curves and straight lines.

[0074] Furthermore, the boundary portion 61 between the front first cushion region 60a and the front second cushion region 60b may be a joint portion formed by bonding the front first cushion region 60a and the front second cushion region 60b after molding them respectively, or may be an impregnated layer formed by one layer penetrating into the other layer in the molding of the front second cushion region 60b with respect to the front first cushion region 60a. Further, the boundary portion 61 may be a compatible portion in which the molding material of the front first cushion region 60a and the molding material of the front second cushion region 60b are mixed and cured.

[0075] Note that the rear cushion region 62, the right side cushion region 64, and the left side cushion region 66 may be molded with the same material as the front first cushion region 60a or the front second cushion region 60b, or may be molded with materials different from both.

[0076] Here, based on FIG. 8, the positional relationship between the boundary portion 61 and the S springs 14a and 14b which are pressure receiving members will be described. As shown in FIG. 8, the boundary portion 61 and the S spring 14b are arranged at positions where at least a part thereof overlaps in the sheet front-rear direction. Here, the upper end portion 61a is the end portion on the upper side of the sheet of the boundary portion 41, and the lower end portion 61b is the end portion on the lower side of the sheet of the boundary portion 61. In the example shown in FIG. 8, the upper end portion 61a and the lower end portion 61b are at substantially the same position in the sheet front-rear direction, and both the upper end portion 61a and the lower end portion 61b are arranged at positions overlapping at least a part of the S spring 14b in the sheet front-rear direction.

[0077] Note that in the example shown in FIG. 8, the boundary portion 61 is arranged at a position overlapping the S spring 14b in the sheet front-rear direction, but the boundary portion 61 may be arranged at a position overlapping the S spring 14a in the sheet front-rear direction.

[0078] As shown in FIG. 8, since the boundary portion 61 and the S spring 14b are arranged at positions overlapping in the front-rear direction of the seat, the boundary portion 61 receiving the load of the occupant can be supported by the S spring 14b. And at the boundary portion 61, at the portion where the hardness changes from the hardness of the front first cushion region 60a to the hardness of the front second cushion region 60b, by being supported by the S spring 14b as described above, the change in hardness around the boundary portion 61 can be alleviated.

[0079] <Modification example> Next, a modification example of the seat back pad 2a will be described with reference to FIGS. 9 to 14. In the examples shown in FIGS. 9 to 14, although it is different from the seat back pad 2a described above regarding the configuration of the boundary portion 41 of the seat back pad 2a, since they are common in other points, the differences will be described below, and the description of the common points will be omitted.

[0080] FIG. 9 shows a V-V cross-sectional view of the seat back pad 2a according to the first modification example. As shown in FIG. 9, in the seat back pad 2a according to the first modification example, the front end portion 41a and the rear end portion 41b of the boundary portion 41 are located at different heights in the up-down direction of the seat, and the connection surface between the front end portion 41a and the rear end portion 41b forms a stepped structure (in other words, the front end portion 41a and the rear end portion 41b are connected in a stepped structure (stepwise)). Note that the front end portion 41a is located between the S spring 23a and the S spring 23b in the up-down direction of the seat, and the rear end portion 41b is located at a position overlapping the S spring 23a in the up-down direction of the seat. Also, the boundary portion 41 shown in FIG. 9 may be configured as an impregnated layer or a joint portion.

[0081] In this way, by forming the boundary portion 41 into a stepped structure with different heights of the front end portion 41a and the rear end portion 41b in the up-down direction of the seat, and opposing one end portion (the rear end portion 41b in this example) to the S spring 23a, the change in hardness between the boundary portion 41 and its surroundings in the seat back pad 2a can be made stepwise, and the rapid change in hardness between the boundary portion and its surroundings can be suppressed. Thereby, the change in hardness around the boundary portion 41 can be alleviated.

[0082] FIG. 10 shows a V-V cross-sectional view of the seat back pad 2a according to the second modification. As shown in FIG. 10, in the seat back pad 2a according to the second modification, the front end 41a and the rear end 41b of the boundary portion 41 are located at different heights in the seat vertical direction, and the connection surface between the front end 41a and the rear end 41b has a gradient structure (in other words, the front end 41a and the rear end 41b are connected by a gradient structure). Note that the front end 41a is located between the S springs 23a and 23b in the seat vertical direction, and the rear end 41b is located at a position overlapping the S spring 23a in the seat vertical direction. Further, the boundary portion 41 shown in FIG. 10 may be configured as an impregnated layer or a joint portion.

[0083] In this way, by forming the boundary portion 41 into a gradient structure in which the heights of the front end 41a and the rear end 41b in the seat vertical direction are different, and opposing one end (the rear end 41b in this example) to the S spring 23a, the hardness change between the boundary portion 41 and its surroundings in the seat back pad 2a can be made smooth, and it is possible to prevent the hardness of the boundary portion and its surroundings from changing abruptly. Thereby, the change in hardness around the boundary portion 41 can be alleviated.

[0084] FIG. 11 shows a V-V cross-sectional view of the seat back pad 2a according to the third modification. As shown in FIG. 11, in the seat back pad 2a according to the third modification, the boundary portion 41 has the same gradient structure as in the second modification described above, but is different from the second modification in the following points. That is, in the third modification, a groove portion 58 is provided in the portion of the front end 41a of the boundary portion 41, and further, a hanging-in portion 59 such as a wire for hanging in the skin material is provided in the groove portion 58, which is different from the second modification.

[0085] Thus, also in the third modification example, similar to the second modification example, the boundary portion 41 has a gradient structure in which the heights in the sheet vertical direction of the front end portion 41a and the rear end portion 41b are different. By opposing one end portion (the rear end portion 41b in this example) to the S spring 23a, the change in hardness between the boundary portion 41 and its surroundings in the seat back pad 2a can be made smooth, and it is possible to prevent the hardness from changing abruptly between the boundary portion and its surroundings. Thereby, the change in hardness in the vicinity of the boundary portion 41 can be alleviated. Further, in the third modification example, a groove portion 58 is provided in front of the boundary portion 41, so that the occupant does not come into contact with the boundary portion 41, and thus the discomfort of the occupant at the boundary portion 41 can be reduced.

[0086] In the first to third modification examples described above, the front end portion 41a is arranged between the S springs 23a and 23b, and the rear end portion 41b is arranged at a position overlapping the S spring 23a in the vertical direction. However, the front end portion 41a may be arranged at a position overlapping the S spring 23a or the S spring 23b in the vertical direction, and the rear end portion 41b may be arranged between the S springs 23a and 23b.

[0087] FIG. 12 shows a V-V cross-sectional view of the seat back pad 2a according to the fourth modification example. As shown in FIG. 12, in the seat back pad 2a according to the fourth modification example, the boundary portion 41 has a structure in which a groove portion 58 similar to that in the third modification example is provided, but it is different from the third modification example in the following points. That is, in the fourth modification example, the boundary portion 41 is different from the third modification example in that it is a compatible portion in which the material of the lower first cushion region 40a and the material of the lower second cushion region 40b are compatible.

[0088] Thus, in the fourth modification example, by opposing the boundary portion 41 to the S spring 23a, the change in hardness between the boundary portion 41 and its surroundings in the seat back pad 2a is made smooth, and it is possible to prevent the hardness from changing abruptly between the boundary portion and its surroundings. Further, by making the boundary portion 41 a compatible portion and increasing the load input area of the boundary portion 41, the discomfort of the occupant at the boundary portion 41 can be reduced. Also, in the fourth modification example, the skin material can be suspended in the suspension portion 59 provided in the groove portion 58 provided in the boundary portion 41. Thereby, since sagging of the skin material is prevented at the boundary portion 41, the discomfort at the boundary portion 41 can be reduced.

[0089] FIG. 13 shows a V-V cross-sectional view of the seat back pad 2a according to the fifth modification example. As shown in FIG. 13, in the seat back pad 2a according to the fifth modification example, each surface except the rear surface (the surface on the seat rear side) of the lower first cushion region 40a is covered with the lower second cushion region 40b, and the boundary portion 41 between the lower first cushion region 40a and the lower second cushion region 40b does not reach the front surface of the seat back pad 2a. In the example shown in FIG. 13, at least one of the rear end portions 41b of the boundary portion 41 is provided at a position facing the S spring 23a. In the example shown in FIG. 13, the lower rear end portion 41b of the boundary portion 41 is located below the S spring 23b, but the rear end portion 41b may be provided at a position facing the S spring 23b.

[0090] Also, in the example shown in FIG. 13, each surface except the rear surface of the lower first cushion region 40a is covered with the lower second cushion region 40b, but each surface except the front surface of the lower first cushion region 40a may be covered with the lower second cushion region 40b so that the boundary portion 41 does not reach the rear surface of the seat back pad 2a.

[0091] FIG. 14 shows a V-V cross-sectional view of the seat back pad 2a according to the sixth modification. As shown in FIG. 14, in the seat back pad 2a according to the sixth modification, the front end portion 41a at the boundary portion 41 between the lower first cushion region 40a and the lower second cushion region 40b is provided at a position facing the S spring 23b, and the rear end portion 41b is provided at a position facing the S spring 23a. Further, not limited to the example shown in FIG. 14, the front end portion 41a of the boundary portion 41 may be provided at a position facing the S spring 23a, and the rear end portion 41b may be provided at a position facing the S spring 23b.

[0092] Incidentally, the configurations of the above-described first to sixth modifications may be similarly applied to the boundary portion 61 of the seat cushion pad 1a.

Explanation of Reference Numerals

[0093] S vehicle seat Sa seat frame 1 seat cushion 1a seat cushion pad 1b skin 2 seat back 2a seat back pad 2b skin 3 headrest 3a headrest pad 3b skin 10 cushion frame 11 cushion side frame 12 pan frame 13 frame connecting pipe 14a, 14b S spring (pressure receiving member) 15 reclining mechanism 16 connecting shaft 17 spiral spring 18 spring locking member 18a bent portion 20 seat back frame 21 upper frame 22 side frame 22a front bent portion 22b rear bent portion 22c recess 23a, 23b S-spring (pressure-receiving member) 30 lower frame 31 frame main body part 32 frame bending part 33a upper flange part 33b lower flange part 38 fastening bolt 40 lower cushion region 40a first lower cushion region 40b second lower cushion region 41 boundary part 41a front end 41b rear end 42 upper cushion region 44 right side cushion region 46 left side cushion region 48 groove part 50 press felt 52 through hole for headrest 54, 56 suspension wire 58 groove part 59 suspension part 60 front cushion region 60a first front cushion region 60b second front cushion region 61 boundary part 61a upper end 61b lower end 62 rear cushion region 64 right side cushion region 66 left side cushion region 68 groove part

Claims

1. A seat back frame that forms the framework of a seat back that constitutes a backrest surface; a pressure receiving member that is supported on the seat back frame in a seat width direction and receives a load of an occupant; a seat back pad having a plurality of regions each made of a different material and disposed between a skin material covering the seat back and the pressure-receiving member; the seat back pad includes an upper cushion region that supports an upper part of an upper body of an occupant, a right side cushion region that supports a right side of an upper body of the occupant, and a left side cushion region that supports a left side of an upper body of the occupant, the right side cushion region being separated by a groove portion; a front end portion and a rear end portion of the boundary portion of the plurality of regions made of different materials are located at the same position in the seat up-down direction; the boundary portion is provided along the seat width direction and is located above a lumbar support region that supports the lumbar vertebrae of an occupant in the seat up-down direction, The vehicle seat is characterized in that a second groove portion is provided in front of the boundary portion.

2. The seat back frame comprises an upper frame formed in an inverted U-shape on the upper side, left and right side frames arranged on the left and right sides and connected to the upper frame, and a lower frame installed on the lower end of the inner surface of the side frames, The vehicle seat according to claim 1 , wherein the boundary portion is located between the side frames in the seat width direction.

3. A vehicle seat as described in claim 1 or 2, characterized in that the boundary portion and the portion of the groove portion arranged along the seat width direction are arranged side by side in the seat up-down direction.

4. The seat back pad has a lower cushion area surrounded by the groove portion on at least three sides in an inverted U shape, 4. The vehicle seat according to claim 1, wherein the boundary portion is provided within the lower cushion region.

5. A vehicle seat as described in any one of claims 1 to 4, characterized in that a recessed portion is formed on the side of the lower end of the seat back pad, in which the width of the seat back pad becomes smaller at a position lower than the boundary portion.

6. A seat cushion frame that forms the framework of a seat cushion, which is a seating portion that supports an occupant from below; a reclining mechanism provided between the seat cushion frame and the seat back frame and rotatably connecting the seat back, A seat cushion pad is placed on the seat cushion frame, and the seat cushion pad is covered with a cushion covering material. A headrest is disposed on the upper surface side of the seat back, A headrest pad is placed on the pillar of the headrest, and the headrest pad is covered with a headrest covering material.

6. The vehicle seat according to claim 5, wherein the recessed portion is provided so as to avoid the reclining mechanism.

7. A vehicle seat as described in any one of claims 1 to 6, characterized in that the width of the boundary portion in the seat vertical direction is greater than the width of the second groove portion in the seat vertical direction, and the boundary portion is arranged across the second groove portion in the seat vertical direction.

8. 8. The vehicle seat according to claim 1, wherein the hardness of the seat back pad in a region below the boundary portion is higher than the hardness of the region above the boundary portion.

9. The vehicle seat according to any one of claims 1 to 8, wherein a hanging portion of the cover material is attached to the second groove portion formed in the boundary portion.

10. 10. The vehicle seat according to claim 1, wherein the boundary portion is a compatible portion in which the materials of the plurality of regions made of different materials are compatible with each other.

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