Cushion spring

Abstract

To provide a cushion spring which can appropriately improve roll stiffness of a side part of a seat cushion.SOLUTION: A cushion spring 10 comprises: a pair of right and left formed wires 11 which are bridged on a seat cushion frame in a front-back direction; and a resin member 12 which is connected therewith. Each of the formed wires 11 includes a center wire 11A and a side wire 11B which are arrayed to each other in the right and left direction and extend in the front-back direction. The resin member 12 includes a rear connecting part 12C and a pair of deflection restraining parts 12A. The rear connecting part 12C extends to connect to right and left between the side wires 11B and the center wires 11A at a rear region of an ischium support part and between the center wires 11A. Each of the deflection restraining parts 12A extends connecting between all crank parts B1 that are repeatedly bent in the right and left direction formed from the rear connecting part 12C to each of the side wires 11B.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a cushion spring, and more particularly to a cushion spring that is connected to a seat cushion frame in the front-rear direction of a seat and receives the load of a seated occupant on its surface. [Background technology]

[0002] Patent Document 1 discloses a cushion spring that is bridged to a seat cushion frame that forms the framework of the seat cushion and receives the load of a seated occupant on its surface. This cushion spring includes a pair of left and right formed wires that are bridged between a front frame portion and a rear frame portion of the seat cushion frame. Each formed wire is folded back so as to form a U-shape in a plan view. Each formed wire is bridged so that the folded back center wire and side wire extend in the front-rear direction between the front frame portion and the rear frame portion of the seat cushion frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-73115 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, the center wire and the side wires are symmetrical to each other. Therefore, when increasing the roll rigidity of the side portion of the seat cushion, it is necessary to take measures such as partially hardening the side portion of the cushion pad. However, a configuration in which the hardness of the cushion pad is partially changed is likely to cause the pad to sag, vary in position, and vary in hardness, making it difficult to stably increase the roll rigidity. Therefore, the present invention provides a cushion spring that can appropriately increase the roll rigidity of the side portion of the seat cushion. [Means for solving the problem]

[0005] To solve the above problems, the cushion spring of the present invention employs the following means.

[0006] That is, a first invention of the present invention is a cushion spring that is bridged to a seat cushion frame in the seat fore-and-aft direction and receives the load of a seated occupant on its surface, the cushion spring having a pair of formed wires that are aligned in the seat width direction and bridged to the seat cushion frame in the seat fore-and-aft direction, and a resin member that is joined to the pair of formed wires, wherein the pair of formed wires each have a center wire and a side wire that are aligned with each other in the seat width direction and extend in the seat fore-and-aft direction, the center wire and the side wire are arranged in this order from the center of the seat cushion frame in the seat width direction toward the outside, and the resin member has a rear connecting portion that extends to connect between each of the side wires and the center wire and between each of the center wires in the seat width direction in an area rearward of the seat rear of ischial bone support portions that support the ischial bones of the seated occupant via the seat cushion pad of the pair of formed wires, and a pair of deflection regulating portions that extend from the rear connecting portion to connect between all of the crank portions that are formed on each of the side wires and bent so as to be repeatedly folded back in the seat width direction.

[0007] According to the first aspect of the present invention, when the weight of a seated occupant is applied to one of the formed wires, the load is also transmitted to the other one by the rear connecting portion of the resin member. As a result, each formed wire can stably receive the load without sinking downward. In addition, each bending restriction portion of the resin member can effectively restrict bending of the crank portion formed in each side wire. This makes it difficult for each side wire to sink downward when the load of a seated occupant is received on its surface. As a result, the roll rigidity of the side portion of the seat cushion is appropriately increased.

[0008] A second invention of the present invention is a cushion spring according to the first invention, wherein a pair of the deflection control portions support the seat cushion pad in a planar manner at an obliquely inward angle from the back side of the pad at a position higher than each of the side wires they connect.

[0009] According to the second aspect of the present invention, the pair of flexure restriction parts can support the thighs of the seated occupant in a wide, planar manner from the diagonally outer sides. The pair of flexure restriction parts extend to a position where they connect with the rear connecting part, which is located behind the seat bone support part. Therefore, the pair of flexure restriction parts can also support the bases of the thighs (greater trochanter and lesser trochanter) from the diagonally outer sides. As a result, it is possible to appropriately suppress wobbling in the roll direction of the posture of the seated occupant.

[0010] A third invention of the present invention is a cushion spring according to the first or second invention, wherein a pair of the deflection control portions connect all of the crank portions formed on each of the side wires in the seat front-rear direction across the entire area in the seat width direction.

[0011] According to the third aspect of the present invention, the downward sinking of each side wire can be more effectively restricted. As a result, the roll rigidity of the side portion of the seat cushion can be more appropriately increased. In addition, even if the seated occupant has a relatively small body type, the pair of deflection restricting portions can appropriately support the thighs of the seated occupant from the back side of the pad.

[0012] A fourth invention of the present invention is a cushion spring according to the first or second invention, wherein a pair of the deflection control portions have outward protruding portions that protrude outward beyond the portions of each of the side wires that protrude most outward in the seat width direction and support the seat cushion pad in a planar manner from the back side of the pad.

[0013] According to the fourth aspect of the present invention, the protruding portions protruding from the pair of deflection restricting portions can adequately support the thighs of a seated occupant from the rear side of the pad, even if the seated occupant has a relatively large body type. Each protruding portion protrudes from each deflection restricting portion that is integral with each side wire. Therefore, these protruding portions can provide a stable support that is less likely to sink downward.

[0014] A fifth aspect of the present invention is the cushion spring according to the first or second aspect, wherein inner edges of the pair of deflection restricting portions in the seat width direction have portions that are thinner than outer edges.

[0015] According to the fifth aspect of the present invention, the inner edges of the pair of deflection restricting portions are more flexible than the outer edges. This makes it possible to reduce the change in hardness between the area where the pair of deflection restricting portions are present and the area where they are not present. As a result, even if the pair of deflection restricting portions are present, it is possible to appropriately increase the dispersion of seating pressure when sitting.

[0016] The sixth invention of the present invention is a cushion spring according to the first or second invention, wherein the rear connecting portion has a central connecting portion connecting between the center wires and a pair of side connecting portions connecting between each of the side wires and the center wire, and the central connecting portion and the pair of side connecting portions support the seat cushion pad in a planar manner at a diagonally forward angle from the back side of the pad at a position higher than each of the center wires and each of the side wires that they connect.

[0017] According to the sixth aspect of the present invention, the center connecting portion and the pair of side connecting portions can provide a wide, planar support for the rear part of the seated occupant's buttocks behind the ischial bones from the diagonally rear side. This can appropriately suppress the wobbling of the seated occupant's pelvis in the roll direction. As a result, forward sliding caused by the wobbling of the seated occupant's buttocks can be appropriately suppressed.

[0018] The seventh invention of the present invention is a cushion spring according to the first or second invention, wherein the rear connecting portion has a concave clamping portion recessed from the front side of the seat to the rear side of the seat so that an object can be clamped from the rear side of the seat, and a rib extending into the recess of the clamping portion so as to form an upper surface flush with the rear connecting portion.

[0019] According to the seventh aspect of the present invention, even if the concave clamp portion is formed in the rear connecting portion, it is possible to appropriately ensure a support surface in the rear connecting portion that supports the seat cushion pad from the rear side of the pad. [Brief description of the drawings]

[0020] [Figure 1] 1 is a perspective view illustrating a schematic configuration of a cushion spring according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view showing the internal skeleton of the seat cushion. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 6 is a cross-sectional view of the seat cushion taken along line VI-VI in FIG. 5. [Figure 7] 2 is a cross-sectional view of the seat cushion taken along a vertical plane passing through the center in the seat width direction. FIG. [Figure 8] FIG. 11 is a plan view illustrating a schematic configuration of a cushion spring according to a second embodiment. [Figure 9] FIG. 11 is a plan view illustrating a schematic configuration of a cushion spring according to a third embodiment. [Figure 10] FIG. 10 is a view taken along the X arrow in FIG. [Figure 11] FIG. 13 is a plan view illustrating a schematic configuration of a cushion spring according to a fourth embodiment. [Figure 12] 12 is a cross-sectional view taken along line XII-XII in FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] First Embodiment (Schematic configuration of cushion spring 10) First, the configuration of a cushion spring 10 according to a first embodiment of the present invention will be described with reference to Figures 1 to 7. In the following description, when directions such as front, back, up, down, left and right are indicated, they refer to the respective directions shown in each figure.

[0023] In addition, when a direction is indicated with "seat" affixed thereto, such as the "seat width direction," it refers to the respective direction based on the seat cushion 1. In addition, in the following description, when a specific reference figure is not indicated or when there is no reference symbol corresponding to a reference figure, any of Figures 1 to 7 will be appropriately referred to.

[0024] As shown in Fig. 1, a cushion spring 10 according to this embodiment is applied to a seat cushion 1 of an automobile seat. The automobile seat includes a seat back (not shown) that serves as a backrest for a seated passenger, and the seat cushion 1 that serves as a seating portion.

[0025] The seat cushion 1 is installed on a floor of an automobile (not shown) via slide rails 5. This allows the position of the seat cushion 1 relative to the floor in the front-rear direction of the seat to be adjusted via the slide rails 5.

[0026] The slide rail 5 is installed to have a front-up rail angle of approximately 1 degree with respect to a floor (not shown). As a result, the seat cushion 1 is installed to face upward at approximately 1 degree with respect to the floor via the slide rail 5. Note that the front-up rail angle of the slide rail 5 is not limited to 1 degree, and may be 0 degrees or 5 degrees. Alternatively, it may be any other angle.

[0027] The seat cushion 1 has a seat cushion frame 2 that forms the framework thereof, and a seat cushion pad 3 that covers the upper side of the seat cushion frame 2. The seat cushion 1 further has a seat cushion cover 4 that covers the seat cushion pad 3 from the pad surface side.

[0028] The seat cushion 1 further includes a cushion spring 10 that is bridged to the seat cushion frame 2 in the front-rear direction of the seat. The cushion spring 10 functions as a pad receiving portion that receives the load of a seated occupant on its surface via the seat cushion pad 3.

[0029] 2, the seat cushion frame 2 is made of metal members assembled into a frame shape in a plan view. Specifically, the seat cushion frame 2 has lower arms 2A forming the left and right side frameworks of the seat cushion 1, and a front pipe 2B integrally bridging front portions of the lower arms 2A. The seat cushion frame 2 further has a rear pipe 2C integrally bridging rear portions of the lower arms 2A, and a front panel 2D integrally bridging upper edges of the front ends of the lower arms 2A.

[0030] 1, the seat cushion pad 3 is made of a polyurethane foam molded body. The seat cushion pad 3 is set so as to cover the entire upper area of ​​the seat cushion frame 2 from above the seat. As a result, the seat cushion pad 3 is set so that its peripheral portion is firmly supported from below the seat by the seat cushion frame 2, and its central portion is gently supported from below the seat by the cushion spring 10.

[0031] The seat cushion cover 4 is made of a planar member made of fabric. The seat cushion cover 4 is placed over the seat cushion pad 3 set on the upper part of the seat cushion frame 2, from the surface side of the pad. The front, rear, left and right ends of the seat cushion cover 4 are pulled under the seat and secured to the seat cushion frame 2. As a result, the seat cushion cover 4 is stretched widely over the surface of the seat cushion pad 3, and presses the seat cushion pad 3 against the upper part of the seat cushion frame 2 to hold it in a fixed position.

[0032] As shown in Fig. 3, the cushion spring 10 has a pair of left and right formed wires 11 made of round bar-shaped processed springs bent into a U-shape in plan view, and resin members 12 formed into a U-shape in plan view and connected to each formed wire 11. As shown in Fig. 4, each formed wire 11 is made of a single wire bent into a U-shape in plan view.

[0033] Specifically, each formed wire 11 is made of a wire bent into a U-shape in plan view, having a center wire 11A and a side wire 11B that are aligned in the seat width direction and extend in the seat front-rear direction. The center wire 11A and the side wire 11B have their rear ends connected to each other and their front ends spaced apart to form a U-shape in plan view.

[0034] Each formed wire 11 is shaped symmetrically in the seat width direction. Also, each formed wire 11 is arranged so as to be aligned symmetrically with respect to each other in the seat width direction. As shown in Fig. 2, each formed wire 11 is arranged so that the wire aligned toward the center of the seat cushion frame 2 in the seat width direction is a center wire 11A, and the wire aligned on the outside is a side wire 11B.

[0035] A front hook portion 11C is formed at the front end of the center wire 11A and the side wire 11B of each formed wire 11 so that the front end can be hooked from above onto the front pipe 2B. A rear hook portion 11D is formed at the rear end of the center wire 11A and the side wire 11B of each formed wire 11 so that the rear end can be hooked from above onto the rear pipe 2C.

[0036] 4, a plurality of crank portions A1, B1 are formed in the center wire 11A and the side wire 11B of each formed wire 11, the crank portions A1, B1 being alternately bent back in a crank shape on one side and the other side in the seat width direction. In each formed wire 11, the crank portions A1 formed in the center wire 11A and the crank portions B1 formed in the side wires 11B are bent toward and away from each other in the seat width direction, and are formed symmetrically in the seat width direction.

[0037] These crank portions A1 and B1 allow each formed wire 11 to extend in the seat width direction as well as the seat front-rear direction, thereby enabling each formed wire 11 to support the seat cushion pad 3 (see FIG. 1) in a planar manner from the rear side of the pad.

[0038] Each formed wire 11 has its center wire 11A and side wire 11B bent in a V shape in a side view. As shown in Fig. 7, this V-shaped bend allows each formed wire 11 to have a ischial bone support portion SA that supports the ischial bones of a seated occupant via the seat cushion pad 3, and is configured to prevent variation in ischial bone support reaction force due to differences in the body type of the seated occupant. This will be described in detail later.

[0039] 3, the resin member 12 is joined symmetrically in the seat width direction to each formed wire 11. Specifically, the resin member 12 has a pair of deflection restricting portions 12A joined to each formed wire 11 in a manner extending in the seat front-rear direction along each side wire 11B.

[0040] The resin member 12 also has a pad support surface 12B that forms the upper surface of each of the flexure restriction portions 12A. Each of the pad support surfaces 12B is formed at a position higher than each of the side wires 11B and forms a support surface that supports the seat cushion pad 3 (see FIG. 1) in a planar manner from the back side of the pad.

[0041] As shown in Fig. 6, each pad support surface 12B is configured to support the seat cushion pad 3 in a planar manner at an obliquely inward angle from the rear side of the pad. Therefore, these deflection restricting portions 12A can support the thighs of the seated occupant widely in a planar manner from the obliquely outer side. Each deflection restricting portion 12A is configured to have edges formed on the inner and outer edges in the seat width direction, which extend downward along each edge in a bent manner.

[0042] As shown in Fig. 5, the pair of flexure restriction parts 12A extend to a position where they are connected to the rear connecting part 12C, which is located on the rear side of the seat further than the ischial support part SA (see Fig. 7). Therefore, the pair of flexure restriction parts 12A can support the bases of the thighs (greater trochanter and lesser trochanter) of the seated occupant from the diagonally outer side. As a result, it is possible to appropriately suppress wobbling in the roll direction of the posture of the seated occupant.

[0043] The resin member 12 further has a rear connecting portion 12C extending in the seat width direction so as to connect the rear portions of the respective flexure regulating portions 12A. The resin member 12 is integrally formed with each formed wire 11 by integral molding. The resin member 12 is formed in a U-shape in a plan view with an opening between each flexure regulating portion 12A toward the front of the seat, due to the configuration including the pair of flexure regulating portions 12A and the rear connecting portion 12C.

[0044] Next, a detailed configuration of the resin member 12 will be described. As shown in Fig. 5, each deflection regulating portion 12A is formed so as to extend continuously in the seat front-rear direction along each of the straight vertical wire portions B2 that extend intermittently in the seat front-rear direction between the front hook portion 11C and the rear hook portion 11D of each side wire 11B. Each of the vertical wire portions B2 is formed side by side in a position on the same straight line.

[0045] As a result, each flexure restriction portion 12A is formed to connect all of the adjacent crank portions B1 in the front and rear of each side wire 11B. Each flexure restriction portion 12A has an extension portion A2 that extends in such a way that the connection width in the seat width direction of the portion connecting the crank portions B1 is continuously expanded inward in the seat width direction toward the rear of the seat.

[0046] Each of the extensions A2 is formed to project outwardly so as to define an inner peripheral edge of a concave curved surface in plan view along the outer edge of the buttocks of a seated occupant. Due to these extensions A2, each of the deflection restriction parts 12A is formed to have a shape in which the connection width of the part connecting the foremost crank part B1 of each side wire 11B and the second-from-front crank part B1 is narrowest.

[0047] Each flexure restriction portion 12A has a second widest connecting width between the second crank portion B1 from the front and the third crank portion B1 from the front of each side wire 11B. Each flexure restriction portion 12A has a second widest connecting width between the third crank portion B1 from the front and the fourth crank portion B1 from the front of each side wire 11B.

[0048] More specifically, each flexure restriction portion 12A is shaped to extend beyond the third crank portion B1 from the front and the fourth crank portion B1 from the front of each side wire 11B to the inside in the seat width direction and connect to the rear connecting portion 12C. In this sense, each extension portion A2 extending beyond the third crank portion B1 from the front and the fourth crank portion B1 from the front to the inside in the seat width direction forms part of the rear connecting portion 12C.

[0049] Each of the flexure restricting portions 12A is not formed at a position directly below the seat bones (not shown) of the seated occupant, but is formed at a position recessed from directly below the seat bones to the outside in the seat width direction. Similarly, the rear connecting portion 12C is not formed at a position directly below the seat bones of the seated occupant, but is formed at a position recessed from directly below the seat bones to the rear of the seat.

[0050] Moreover, each formed wire 11 is not formed at a position corresponding to directly below the ischial bones (not shown) of the seated occupant, but is formed at a position offset in the seat width direction from directly below the ischial bones. Specifically, each formed wire 11 is formed at a position offset inward and outward in the seat width direction from directly below the ischial bones so that the center wire 11A and the side wire 11B are disposed to sandwich positions corresponding to directly below the left and right ischial bones (not shown) of the seated occupant.

[0051] The flexure restriction portions 12A of each formed wire 11 restrict the opening between the five crank portions B1 arranged in front and behind the side wires 11B in the seat front-rear direction. In detail, the flexure restriction portions 12A of each side wire 11B restrict the opening between the front crank portion B1 and the second crank portion B1 in the seat front-rear direction ...

[0052] Each side wire 11B is configured so that the opening between the second crank portion B1 from the front and the third crank portion B1 from the front in the seat front-rear direction is restricted next stronger. Each side wire 11B is configured so that the opening between the third crank portion B1 from the front and the fourth crank portion B1 from the front in the seat front-rear direction is restricted next stronger.

[0053] In addition, the fourth crank portion B1 from the front and the fifth crank portion B1 from the front of each side wire 11B are connected over the entire area in the seat width direction by each bending restriction portion 12A, so that the opening between them in the front-rear direction of the seat is completely restricted. The resin member 12 allows the cushion spring 10 to be configured such that the ease of bending when subjected to a load from a seated occupant differs between the center wires 11A and the side wires 11B, even though the formed wires 11 are formed symmetrically to each other in the seat width direction.

[0054] 6, when the cushion spring 10 receives a load from a seated occupant, the center wires 11A are bent so as to sink downward relatively flexibly. On the other hand, the bending of each of the side wires 11B is restricted so that the side wires 11B are less likely to sink downward than the center wires 11A.

[0055] In detail, the bending restriction of each side wire 11B is weakened toward the front where the load applied by the seated occupant is smaller, and is strengthened toward the rear where the load applied by the seated occupant is larger, due to the shape of the bending restriction portion 12A with a varying joint width. This makes it possible to appropriately increase the roll rigidity of each side portion of the seat cushion 1.

[0056] The pad support surface 12B forming the upper surface of each deflection restricting portion 12A functions as a receiving surface for the seat cushion pad 3 when the weight of a seated occupant is applied to each side portion of the seat cushion 1. Since each pad support surface 12B is integrally provided with each side wire 11B of the cushion spring 10, which is deflection restricted, it is possible to perform stable receiving that is unlikely to sink downward.

[0057] More specifically, since the pad support surfaces 12B are integrally connected to each other by the rear connecting portion 12C, when a load from a seated occupant is applied to one of the pad support surfaces 12B, the load is transmitted to the opposite side wire 11B via the other pad support surface 12B. This allows each pad support surface 12B to stably receive the load of the seated occupant without sinking downward when the load is applied to each side portion of the seat cushion 1.

[0058] 5, the rear connecting portion 12C of the resin member 12 has a central connecting portion C1 that connects the left and right center wires 11A and a pair of side connecting portions C2 that connect the left and right side wires 11B and the center wire 11A. The central connecting portion C1 and the left and right side connecting portions C2 are each formed to have a flush upper surface.

[0059] The central connecting portion C1 is configured to have an opening Cn formed in its center in the seat front-rear direction, penetrating the seat in the shape of a long hole extending in the seat width direction. The central connecting portion C1 exposes a part of the crank portion A1 of each center wire 11A from the opening Cn. This makes it easier for the central connecting portion C1 to flex the crank portion A1 of each center wire 11A at the part exposed from the opening Cn when a load is applied from a seated occupant. Note that the central connecting portion C1 may be configured to not have the opening Cn, and to be integrally connected to each center wire 11A over its entire area.

[0060] As shown in Fig. 3, the upper surfaces of the central connecting portion C1 and the left and right side connecting portions C2 are formed at a position higher than the center wires 11A and the side wires 11B that they connect. The upper surfaces of the central connecting portion C1 and the left and right side connecting portions C2 form a support surface that supports the seat cushion pad 3 (see Fig. 1) from the back side of the pad in a planar manner. As shown in Fig. 7, the upper surfaces of the central connecting portion C1 and the left and right side connecting portions C2 form a support surface that supports the seat cushion pad 3 from the back side of the pad at an obliquely forward angle in a planar manner.

[0061] Therefore, the center joint C1 and the left and right side joints C2 can provide a wide, planar support for the rear part of the seated occupant's buttocks behind the ischial bones from the diagonally rear side. This can appropriately suppress the wobbling of the seated occupant's pelvis in the roll direction. As a result, forward sliding caused by the wobbling of the seated occupant's buttocks can be appropriately suppressed.

[0062] 3 and 5, the left and right side connecting parts C2 of the rear connecting part 12C are formed with concave clamp parts 12D capable of clamping a wire harness (not shown) (object) from the rear side of the seat. Each clamp part 12D is formed in a concave shape recessed in a vertical oval shape in a plan view from the upper surface of the left and right side connecting parts C2.

[0063] Ribs D1 are formed in the recess of each clamping portion 12D, projecting in a symmetrical upright shape from the left and right inner peripheral surfaces. Each rib D1 is formed so that its bottom surface is connected to the bottom surface of the corresponding clamping portion 12D. Also, each rib D1 is formed so that its upper surface is flush with the left and right side connecting portions C2. Even if the left and right side connecting portions C2 each have a concave clamping portion 12D formed on their upper surfaces, each rib D1 can appropriately secure a support surface on the upper surface of each side connecting portion C2 that supports the seat cushion pad 3 (see FIG. 1) from the back side of the pad.

[0064] As shown in FIG. 5, grooves formed in each pad support surface 12B that are recessed along the shape of each side wire 11B are grooves through which pressing pins (not shown) are passed to fix each formed wire 11 in position within the molding die for the resin member 12.

[0065] 7, the ischium support portion SA formed in each formed wire 11 is formed in a shape that reduces variation in ischium support reaction force due to differences in the body type of the seated occupant. Specifically, the ischium support portion SA is configured so that the entire area R in the front-rear direction of the seat between the first ischium support portion SA1 that supports the ischium when the AM95 mannequin is seated, and the second ischium support portion SA2 that supports the ischium when the JM32 mannequin is seated, is a flat spring surface that does not bend in the up-down direction of the seat in a side view.

[0066] Here, the AM95 mannequin is a mannequin with a relatively large body type that fits 95% of American men, and the JM32 mannequin is a mannequin with a relatively small body type that fits 32% of Japanese men. Therefore, most people's body types fall between the AM95 mannequin and the JM32 mannequin.

[0067] The ischial support portion SA extends straight upward toward the front in the region R in the side view. The portion of the seat cushion pad 3 disposed on the region R of the ischial support portion SA is formed so that the pad thickness is constant in the direction perpendicular to the extension direction of the ischial support portion SA.

[0068] With this configuration, the cushion spring 10 supports the ischial bones so that substantially the same ischial bone support reaction force acts on the ischial bone support portion SA when a person having a body type between the AM95 mannequin and the JM32 mannequin or between these is seated on the seat cushion 1. Therefore, it is possible to appropriately suppress the variation in ischial bone support reaction force due to differences in the body type of the seated occupant.

[0069] Therefore, even if the thickness of the seat cushion pad 3 placed on the region R of the ischial support portion SA is thin, the seating pressure acting on the ischial bones of the seated occupant can be appropriately distributed regardless of the body type. The region R of the ischial support portion SA is an intermediate region that leaves both ends of the straight portion that extends in a straight line between the bending point where each formed wire 11 bends in a V shape in a side view and the end point of the curve of the front hook portion 11C.

[0070] More specifically, the cushion spring 10 is bridged to the seat cushion frame 2 so that the spring surface of the ischial support portion SA has a front-rising angle θ of approximately 20 degrees with respect to the rail length direction of the slide rail 5. Due to this front-rising angle θ, the cushion spring 10 is able to appropriately suppress forward sliding of the buttocks of the seated occupant.

[0071] 5, the center wire 11A and the side wire 11B of each formed wire 11 are disposed at a position offset in the seat width direction from the position directly below the left and right ischial bones (not shown) of a seated occupant. More specifically, the center wire 11A and the side wire 11B of each formed wire 11 are disposed at a position offset in the seat width direction from the positions directly below the ischial bones of the AM95 mannequin and the JM32 mannequin.

[0072] With the above-described configuration, the seating pressure acting on the ischial bones of a seated occupant can be appropriately distributed regardless of the occupant's body type.

[0073] To sum up, the cushion spring 10 according to this embodiment has the following configuration: In the following, the reference characters in parentheses correspond to the respective components shown in the above embodiment.

[0074] That is, the cushion spring (10) is a spring that is bridged to the seat cushion frame (2) in the front-rear direction of the seat and receives the load of a seated occupant on its surface. The cushion spring (10) has a pair of formed wires (11) aligned in the seat width direction and bridged to the seat cushion frame (2) in the front-rear direction of the seat, and a resin member (12) joined to the pair of formed wires (11).

[0075] The pair of formed wires (11) each have a center wire (11A) and a side wire (11B) that are aligned with each other in the seat width direction and extend in the seat front-rear direction. The center wire (11A) and the side wire (11B) are arranged to be aligned in this order from the center of the seat width direction of the seat cushion frame (2) toward the outside. The resin member (12) has a rear connecting portion (12C) and a pair of flexure restriction portions (12A).

[0076] The rear connecting portion (12C) extends to connect between each side wire (11B) and the center wire (11A) and between each center wire (11A) in the seat width direction in an area rearward of the seat rearward of the ischial bone support portion (SA) that supports the ischial bones of the seated occupant via the seat cushion pad (3) of the pair of formed wires (11). The pair of deflection restricting portions (12A) extend from the rear connecting portion (12C) to connect between all the crank portions (B1) formed on each side wire (11B) that are repeatedly folded back in the seat width direction in the seat front-rear direction.

[0077] According to the above-mentioned configuration, when the weight of a seated occupant is applied to one of the formed wires (11), the rear connecting portion (12C) of the resin member (12) transmits the load to the other one of the formed wires (11). As a result, the formed wires (11) can stably receive the load without sinking downward. In addition, the bending restriction portions (12A) of the resin member (12) can effectively restrict bending of the crank portions (B1) formed on the side wires (11B). This makes it difficult for the side wires (11B) to sink downward when the load of the seated occupant is received on the surface of the side wires (11B). As a result, the roll rigidity of the side portions of the seat cushion (1) is appropriately increased.

[0078] In addition, the pair of flexure restriction parts (12A) support the seat cushion pad (3) from the rear side of the pad at a diagonally inward angle in a planar manner at a position higher than the side wires (11B) connecting them. According to the above configuration, the pair of flexure restriction parts (12A) can support the thighs of the seated occupant widely in a planar manner from the diagonally outer side. The pair of flexure restriction parts (12A) extend to a position where they are connected to the rear connecting part (12C) located on the rear side of the seat from the ischium support part (SA). Therefore, the pair of flexure restriction parts (12A) can support the bases of the thighs (greater trochanter and lesser trochanter) from the diagonally outer side. As a result, it is possible to appropriately suppress the wobbling of the posture of the seated occupant in the roll direction.

[0079] The rear connecting portion (12C) has a central connecting portion (C1) that connects the center wires (11A) and a pair of side connecting portions (C2) that connect each of the side wires (11B) and the center wire (11A). The central connecting portion (C1) and the pair of side connecting portions (C2) planarly support the seat cushion pad (3) at an obliquely forward angle from the rear side of the pad at a position higher than the connecting center wires (11A) and side wires (11B).

[0080] According to the above-mentioned configuration, the central connecting portion (C1) and the pair of side connecting portions (C2) can support the rear part of the buttocks of the seated occupant behind the ischial bones in a wide plane from the diagonally rear side. This can appropriately suppress the wobbling of the pelvis of the seated occupant in the roll direction. As a result, it is possible to appropriately suppress the forward sliding caused by the wobbling of the buttocks of the seated occupant.

[0081] In addition, the rear connecting portion (12C) has a concave clamp portion (12D) recessed from the front side of the seat to the rear side of the seat so that an object (a wire harness, not shown) can be clamped from the rear side of the seat, and a rib (D1) protruding into the recess of the clamp portion (12D) so as to form an upper surface flush with the rear connecting portion (12C). According to the above configuration, even if the concave clamp portion (12D) is formed in the rear connecting portion (12C), it is possible to appropriately ensure a support surface in the rear connecting portion (12C) that supports the seat cushion pad (3) from the rear side of the pad.

[0082] Second Embodiment Next, the configuration of a cushion spring 10 according to a second embodiment of the present invention will be described with reference to Fig. 8. In this embodiment, the second crank portion A3 from the front of each center wire 11A and the second crank portion B3 from the front of each side wire 11B are bent in a direction extending obliquely in the seat front-rear direction, rather than in a direction extending straight in the seat width direction.

[0083] Specifically, the crank portions A3, B3 are formed as follows in comparison with the second crank portions A1, B1 shown in the first embodiment. That is, the crank portions A3, B3 are bent in a direction extending diagonally forward so as to narrow the gap between each of the crank portions A1, B1 arranged in front of them, without narrowing the gap between each of the crank portions A3, B3 and the crank portions A1, B1 arranged in front of them. As a result, the gap between the crank portion A3 of each center wire 11A and the crank portion A1 arranged in rear of it is wider than the configuration shown in the first embodiment.

[0084] As a result, even if the seated occupant has a large build and his / her ischium is relatively forward, the shape of the crank portion A3 of each center wire 11A that extends diagonally forward can reduce the seating pressure acting on the ischium of the seated occupant. Also, because the crank portion A3 of each center wire 11A is shaped to extend diagonally forward, the bending angle of the corner portion at the end thereof is gentler than the bending angle of the corner portions of the second-from-the-front crank portions A1, B1 shown in the first embodiment.

[0085] As a result, the seating pressure acting on the ischial bones of the seated occupant can be more appropriately reduced. Since the configurations other than those described above are the same as those shown in the first embodiment, the same reference numerals are used and detailed description will be omitted.

[0086] Third embodiment Next, a configuration of a cushion spring 10 according to a third embodiment of the present invention will be described with reference to Fig. 9 and Fig. 10. In this embodiment, each of the bending restriction portions 12E coupled to each of the side wires 11B of the resin member 12 has a cylindrical shape extending in such a way as to connect all of the crank portions B1 formed on each of the side wires 11B in the seat front-rear direction over the entire area in the seat width direction.

[0087] Each of the flexure restricting portions 12E is formed to protrude slightly inward in the seat width direction from all of the crank portions B1 of each of the side wires 11B. As shown in Fig. 10, each of the flexure restricting portions 12E is integrally connected to the inner and outer ends of the foremost crank portion B1, the outer ends of the second and third crank portions B1 from the front, and the inner and outer ends of the fourth crank portion B1 from the front, respectively, for each of the side wires 11B.

[0088] Thereby, the opening between all the crank portions B1 of each side wire 11B in the seat front-rear direction is completely restricted by each deflection restricting portion 12E, As a result, the roll rigidity of the side portion of the seat cushion 1 can be further increased.

[0089] Furthermore, for example, even if the seated occupant has a relatively small body type and the thighs are positioned relatively inward, each deflection control portion 12E makes it possible to provide wide, planar support for the thighs from the tip to the base from the back side of the pad.

[0090] The inner edge of each of the deflection regulating parts 12E in the seat width direction is thinner than the outer edge. Specifically, each of the deflection regulating parts 12E is formed in a flat plate shape extending from its inner edge to its outer edge with a substantially constant plate thickness. However, the outer edge of each of the deflection regulating parts 12E has an edge part that extends downward along the outer edge in a bent shape. In addition, the bottom surface of each of the deflection regulating parts 12E has padding parts formed in various places to form joints with each of the side wires 11B.

[0091] Each of the deflection restricting portions 12E is configured such that the inner edge in the seat width direction does not have a bent edge portion like the outer edge, and the inner edge has a portion that is thinner than the outer edge. As a result, the inner edge of each of the deflection restricting portions 12E is configured to be more easily deflected than the outer edge. Note that, among the inner edges of each of the deflection restricting portions 12E, the portions that are connected to the crank portions B1 of each of the side wires 11B are partially padded.

[0092] The above-mentioned thin structure can reduce the change in hardness between the location where each deflection regulating portion 12E is provided and the location inside the location in the seat width direction. As a result, even if each deflection regulating portion 12E is provided, the seating pressure dispersion during sitting can be appropriately improved. The structure in which the inner edge of each deflection regulating portion 12E is thinner than the outer edge may be a structure in which the plate thickness of each deflection regulating portion 12E is gradually thinner from the outer edge to the inner edge, or a structure in which the plate thickness of the inner edge is partially thinner. The other structures are the same as those shown in the first embodiment, so the same reference numerals are used and detailed description is omitted.

[0093] Fourth embodiment Next, the configuration of a cushion spring 10 according to a fourth embodiment of the present invention will be described with reference to Fig. 11 and Fig. 12. In this embodiment, each deflection regulating portion 12A of the resin member 12 has an outward protruding portion A4 that protrudes outward from a portion of each side wire 11B that protrudes most outward in the seat width direction and supports the seat cushion pad 3 in a planar manner from the back side of the pad.

[0094] 11, specifically, each outwardly extending portion A4 is formed in a region between the front-to-rear crank portion B1 of each side wire 11B and the third crank portion B1 of each side wire 11B so as to extend outward from the portion of each side wire 11B that extends most outward in the seat width direction. Each outwardly extending portion A4 has an upper surface that is flush with the pad support surface 12B, which is the upper surface of each deflection restricting portion 12A.

[0095] Each outward protrusion A4 may be bent obliquely upward relative to each deflection restricting portion 12A. Also, each outward protrusion A4 may be protruding outward in the seat width direction from the entire area of ​​each deflection restricting portion 12A in the seat front-rear direction or from an area different from the above-mentioned area.

[0096] By forming the outward projections A4 on each deflection regulating portion 12A as described above, even if the seated occupant has a relatively large body type and the thighs are located relatively outward, it is possible to properly support the thighs of the seated occupant from the back side of the pad. Each outward projection A4 is configured to project from each deflection regulating portion 12A that is integral with each side wire 11B. Therefore, these outward projections A4 also enable stable support that is less likely to sink downward. Since the configuration other than the above is the same as the configuration shown in the first embodiment, the same reference numerals are used and detailed description is omitted.

[0097] Other embodiments Although the present invention has been described above using four embodiments, the present invention can be embodied in various forms other than the above-mentioned embodiments.

[0098] 1. The cushion spring of the present invention is applicable to seat cushions for seats mounted on vehicles such as automobiles and trains, as well as to seat cushions for seats mounted on vehicles other than vehicles such as aircraft and ships. The cushion spring is also applicable to seat cushions for seats other than vehicles.

[0099] 2. The cushion spring does not necessarily have to be provided so that each formed wire is symmetrical in the seat width direction with respect to the seat cushion frame. That is, one formed wire may have a different shape from the other formed wire. Also, the center wire and side wire of each formed wire do not necessarily have to be symmetrical in the seat width direction. Also, the center wire and side wire of each formed wire may not be connected by a single wire, but may be separate wires.

[0100] 3. In the second embodiment, the second crank portion from the front of each center wire is bent in a direction extending diagonally in the seat front-rear direction. However, the frontmost crank portion of each center wire may be bent in a direction extending diagonally in the seat front-rear direction. Also, both the frontmost crank portion and the second crank portion from the front may be bent in a direction extending diagonally in the seat front-rear direction, i.e., to form a V-shape in plan view.

[0101] 4. The inner edge in the sheet width direction of each deflection regulating portion shown in the first embodiment may be configured to be thinner than the outer edge, similarly to the configuration shown in the third embodiment.

[0102] 5. The cushion spring may further include a bridge wire that is integrally provided between the center wire of each formed wire and the front crank portion of the side wire from below. With the above configuration, the bridge wire functions as a stabilizer, and when the weight of a seated occupant is applied to one of the formed wires, the load is transmitted to the other. As a result, each formed wire can provide a stable support that is less likely to sink downward.

[0103] The above-mentioned bridging wire may be provided so as to bridge not only between the front crank parts of the center wires and side wires of each formed wire, but also between other crank parts from below. For example, by bridging each crank part that passes through the rear connecting part of the resin member that supports the rear part of the buttocks with the bridging wire from below, the rear connecting part can more appropriately support the rear part of the buttocks.

[0104] Also, the bridge wire may be provided so as to span integrally between the rear hook portions of the center wires that are hooked onto the rear pipes. This prevents the rear hook portions of the center wires from becoming closer to each other. As a result, when the weight of a seated occupant is applied to the rear connecting portion of the resin member, the rear hook portions of the center wires are prevented from shifting so as to reduce the distance between them, and the rear of the buttocks can be more appropriately supported by the rear connecting portion.

[0105] 6. In each embodiment, an opening is formed in the central connecting portion of the rear connecting portion to expose a part of the crank portion of each center wire. However, the rear connecting portion may be configured so that the central connecting portion does not have the above-mentioned opening. Moreover, regardless of whether an opening is formed in the central connecting portion of the rear connecting portion, the center wire and side wire of each formed wire may be formed so that the portion passing through the rear connecting portion extends straight in the front-rear direction of the seat without a crank portion.

[0106] In addition, the center wire and side wire of each formed wire may have a shape in which the portion passing through the rear connecting portion is bent in a direction extending diagonally in the seat front-rear direction so that both the rearmost crank portion and the second-rearmost crank portion form a V-shape in a plan view. By configuring each formed wire in this way, the wire length can be shortened compared to the configuration in which the portion passing through the rear connecting portion is a crank portion as in the configurations shown in each embodiment. As a result, the support rigidity of each formed wire that supports the rear connecting portion is increased, and the rear of the buttocks can be supported more appropriately. [Explanation of symbols]

[0107] 1 seat cushion 2 Seat cushion frame 2A Lower Arm 2B front pipe 2C Rear pipe 2D Front Panel 3 Seat cushion pad 4 Seat cushion covers 5 Slide rail 10 Cushion spring SA Sit bone support SA1 First ischial support area SA2 Second ischial support area 11 Formed Wire 11A Center Wire A1 Crank section A3 Crank section 11B Side wire B1 Crank section B2 Vertical wire section B3 Crank section 11C Front hook part 11D Rear hook part 12 Resin parts 12A Deflection control section A2 Extension A4 External extension 12B Pad support surface 12C Rear joint C1 Central joint Cn opening C2 Side joint 12D Clamp section D1 Rib 12E Deflection control part θ angle R area

Claims

1. A cushion spring is bridged to a seat cushion frame in the front-rear direction of the seat and receives the load of a seated occupant on its surface, A pair of formed wires arranged in a seat width direction and bridged in a seat front-rear direction to the seat cushion frame; a resin member connected to the pair of formed wires, The pair of formed wires each have a center wire and a side wire that are aligned in the seat width direction and extend in the seat front-rear direction, the center wire and the side wires are arranged in this order from the center of the seat cushion frame in a seat width direction toward an outer side, The resin member has a rear connecting portion extending in the seat width direction between each of the side wires and the center wire and between each of the center wires in an area rearward of the seat from a seat bone support portion that supports the seat bones of a seated occupant via a seat cushion pad of a pair of the formed wires, and a pair of deflection regulating portions extending from the rear connecting portion to connect all of the crank portions formed on each of the side wires that are bent so as to be repeatedly folded back in the seat width direction in the seat front-rear direction of the seat.

2. 2. The cushion spring according to claim 1, The pair of deflection regulating portions support the seat cushion pad in a planar manner at an obliquely inward angle from the rear side of the pad at a position higher than each of the side wires that they connect.

3. The cushion spring according to claim 1 or 2, The pair of deflection restriction portions connect all of the crank portions formed on the side wires in the seat front-rear direction across the entire area in the seat width direction.

4. The cushion spring according to claim 1 or 2, The pair of deflection regulating portions have outward protruding portions that protrude outward beyond the portions of each side wire that protrude furthest outward in the seat width direction and support the seat cushion pad in a planar manner from the back side of the pad.

5. The cushion spring according to claim 1 or 2, The cushion spring has inner edges of the pair of deflection regulating portions in the seat width direction that are thinner than the outer edges.

6. The cushion spring according to claim 1 or 2, The rear connecting portion has a central connecting portion that connects between each of the center wires, and a pair of side connecting portions that connect between each of the side wires and the center wire, and the central connecting portion and the pair of side connecting portions support the seat cushion pad in a planar manner at a diagonally forward angle from the back side of the pad at a position higher than each of the center wires and each of the side wires that they connect.

7. The cushion spring according to claim 1 or 2, The cushion spring has a concave clamping portion recessed from the front side of the seat to the rear side of the seat so that the rear connecting portion can clamp an object from the rear side of the seat, and a rib extending into the recess of the clamping portion so as to form an upper surface flush with the rear connecting portion.

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