Cushion spring

Abstract

To provide a cushion spring which can suppress variations of ischium support reaction force due to a difference in types of physique of seating crewmen.SOLUTION: A cushion spring 10 includes a formed wire 11 which is bridged on a seat cushion frame in a front-back direction. The formed wire 11 includes an ischium support part SA which supports the ischium of a seating crewman through a seat cushion pad 3. The ischium support part SA has a whole region R in a seat front-back direction between a first ischium support part SA1 to be a support part of the ischium when an AM95 mannequin is seated and a second ischium support part SA2 to be a support part of the ischium when a JM32 mannequin is seated so as to form a flush spring surface which does not bend in a seat vertical direction.SELECTED DRAWING: Figure 7

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 connected 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 formed wires that are connected between the front and rear frames of the seat cushion frame.

[0003] Each formed wire is bent in a valley shape in a side view so as to conform to the shape of the back surface of the seat cushion pad. Specifically, each formed wire is bent in a valley shape so as to conform to the shape of the seat cushion pad where the thickness of the pad bulges downward in a portion supporting the ischial bones of a seated occupant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-73115 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration described in Patent Document 1, the shape of the seat cushion pad and each formed wire is set based on a mannequin corresponding to a specific body type such as AM50. Therefore, if the ischial bone position deviates from the target position due to differences in the body type of the seated occupant, the ischial bone support reaction force varies, and the posture of the seated occupant tends to deviate from the target posture. Therefore, the present invention provides a cushion spring that can suppress the variation in ischial bone support reaction force due to differences in the body type of the seated occupant. [Means for solving the problem]

[0006] To solve the above problems, the cushion spring of the present invention employs the following means.

[0007] That is, the first invention of the present invention is a cushion spring that is bridged to a seat cushion frame in the front-to-rear direction of the seat and receives the load of a seated occupant on its surface, the cushion spring having a formed wire bridged to the seat cushion frame in the front-to-rear direction of the seat, the formed wire having an ischial bone support portion that supports the ischial bones of the seated occupant via the seat cushion pad, the ischial bone support portion forming a flush spring surface that is not curved in the up-down direction of the seat over the entire front-to-rear area of ​​the seat between a first ischial bone support portion that supports the ischial bones when an AM95 mannequin is seated, and a second ischial bone support portion that supports the ischial bones when a JM32 mannequin is seated.

[0008] 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.

[0009] According to the first aspect of the present invention, the ischial support portion of the formed wire is shaped to have a flush spring surface in the above-mentioned area, thereby making it possible to appropriately suppress variations in the ischial support reaction force due to differences in the body shape of the seated occupant.

[0010] The second invention of the present invention is a cushion spring according to the first invention, wherein the formed wire has a plurality of wire portions in the seat width direction that are bridged to the seat cushion frame in the seat fore-and-aft direction, and the plurality of wire portions are positioned in the seat width direction away from directly below the ischial bones when the AM95 mannequin is seated and away from directly below the ischial bones when the JM32 mannequin is seated.

[0011] According to the second invention, since the ischial support portion of the formed wire forms a flush spring surface, the seating pressure distribution can be appropriately improved even if the thickness of the seat cushion pad placed over this area is thin.

[0012] The third invention of the present invention is a cushion spring according to the first or second invention, wherein the formed wire is bridged so that the spring surface is angled upward toward the front with respect to the rail length direction of a slide rail that connects the seat cushion frame to the seat cushion frame so that the seat cushion frame can slide in the fore-and-aft direction of the seat relative to a floor.

[0013] According to the third aspect of the present invention, the cushion spring can be provided so as to be capable of preventing the buttocks of the seated occupant from sliding forward. [Brief description of the drawings]

[0014] [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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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 joined 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.

[0027] 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. Here, the center wire 11A and the side wire 11B of each formed wire 11 each correspond to the "wire portion" of the present invention.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The resin member 12 further has a connecting portion 12C extending in the seat width direction so as to connect the rear portions of the respective deflection restricting portions 12A. The resin member 12 is integrally formed with each of the formed wires 11 and is integrally joined thereto.

[0036] 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.

[0037] 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.

[0038] 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 seated person's buttocks. 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-most crank part B1 from the front is narrowest.

[0039] 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.

[0040] 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 connecting portion 12C. In this sense, each extension portion A2 extending from between 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 is a part of the connecting portion 12C.

[0041] 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 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.

[0042] 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.

[0043] 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 ...

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] More specifically, since the pad support surfaces 12B are integrally connected to each other by the connecting portion 12C, when a load from a seated occupant is applied to one pad support surface 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] That is, the cushion spring (10) is a spring that is connected 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 formed wire (11) that is connected to the seat cushion frame (2) in the front-rear direction of the seat. The formed wire (11) has a ischium support portion (SA) that supports the ischium of the seated occupant via the seat cushion pad (3).

[0061] The ischial support portion (SA) forms a flush spring surface with no bending in the up-down direction of the seat over the entire fore-and-aft area (R) between the first ischial support portion (SA1), which supports the ischial bones when the AM95 mannequin is seated, and the second ischial support portion (SA2), which supports the ischial bones when the JM32 mannequin is seated.

[0062] In this way, by making the ischial support portion (SA) of the formed wire (11) have a shape having a flush spring surface in the above-mentioned region (R), it is possible to appropriately suppress variations in the ischial support reaction force due to differences in the body shape of the seated occupant.

[0063] The formed wire (11) has a plurality of wire portions (11A, 11B) in the seat width direction that are bridged in the seat front-rear direction to the seat cushion frame (2). The plurality of wire portions (11A, 11B) are positioned in the seat width direction away from directly below the ischial bones of the AM95 mannequin when seated and away from directly below the ischial bones of the JM32 mannequin when seated.

[0064] According to the above configuration, since the ischial support portion (SA) of the formed wire (11) forms a flush spring surface, even if the thickness of the seat cushion pad (3) placed on this region (R) is thin, the seating pressure distribution can be appropriately improved.

[0065] In addition, the formed wire (11) is bridged to the seat cushion frame (2) so that the spring surface forms an angle (θ) rising forward with respect to the rail length direction of the slide rail (5) that connects the seat cushion frame (2) to the floor so that the seat cushion frame (2) can slide in the front-rear direction of the seat. According to the above configuration, the cushion spring (10) can be provided so as to suppress forward sliding of the buttocks of the seated occupant.

[0066] Other embodiments Although one embodiment of the present invention has been described above, the present invention can be embodied in various forms other than the above embodiment.

[0067] 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.

[0068] 2. The cushion spring does not necessarily have to be provided with a pair of formed wires symmetrical to the seat cushion frame in the seat width direction. In other words, one formed wire may have a different shape from the other formed wire. Also, the center wire and side wires constituting the wire portion of the formed wire do not necessarily have to have shapes symmetrical to each other in the seat width direction.

[0069] 3. The ischial support portion may be one that forms a flush spring surface that does not bend in the up-down direction of the seat in the area between the first ischial support portion that supports the ischial bones when the AM95 mannequin is seated and the second ischial support portion that supports the ischial bones when the JM32 mannequin is seated, in the front-to-rear direction of the seat. Therefore, the ischial support portion may be one that forms a flush spring surface that does not bend in the up-down direction of the seat beyond the above-mentioned areas.

[0070] The formed wire does not necessarily have to be bridged with the seat cushion frame so that the spring surface of the ischial support part is angled upwards at the front, and the spring surface of the ischial support part may be formed parallel to the rail length direction of the slide rail.The formed wire may be configured so that the wire part is located at a position that corresponds to directly below the ischial bones when the AM95 mannequin is seated and / or directly below the ischial bones when the JM32 mannequin is seated. [Explanation of symbols]

[0071] 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 (wire part) A1 Crank section 11B Side wire (wire part) B1 Crank section B2 Vertical wire section 11C Front hook part 11D Rear hook part 12 Resin parts 12A Deflection control section A2 Extension 12B Pad support surface 12C Joint θ angle R region

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, The seat cushion frame has a formed wire bridged in the front-rear direction of the seat, the formed wire has a seat bone support portion that supports the seat bones of a seated occupant via a seat cushion pad, The ischial support portion is a cushion spring that forms a flush spring surface with no bending in the up-down direction of the seat over the entire area in the fore-and-aft direction of the seat, including the first ischial support portion that supports the ischial bones when the AM95 mannequin is seated, and the second ischial support portion that supports the ischial bones when the JM32 mannequin is seated.

2. 2. The cushion spring according to claim 1, The formed wire includes a plurality of wire portions in a seat width direction, the wire portions being bridged to the seat cushion frame in a seat front-rear direction, A cushion spring in which the multiple wire portions are positioned in the seat width direction away from directly below the ischial bones when the AM95 mannequin is seated and away from directly below the ischial bones when the JM32 mannequin is seated.

3. The cushion spring according to claim 1 or 2, The formed wire is bridged to the seat cushion frame so that the spring surface is angled upward toward the front with respect to the rail length direction of a slide rail that connects the seat cushion frame to the floor so that the seat cushion frame can slide in the fore-and-aft direction of the seat.

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