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 formed wire 11 which is bridged on a seat cushion frame in a seat front-back direction; and a resin member 12 which is connected with the formed wire 11. The formed wire 11 consists of one wire including a center wire 11A and a side wire 11B which are arrayed in a seat width direction and ends of which are connected to each other extending in the seat front-back direction. The center wire 11A and the side wire 11B respectively include a plurality of crank parts A1, B1 which are alternatively repeatedly bent in one direction of the seat width direction and in the other direction in a crank shape. The resin member 12 includes a deflection restraining part 12A connecting between the plurality of crank parts B1 so as to regulate opening in the seat front-back direction between the crank parts B1 that are formed in the side wire 11B and are consecutively three or more in the front-back direction.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, the first invention of the present invention is a cushion spring that 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 cushion spring having a formed wire bridged to the seat cushion frame in the front-rear direction of the seat and a resin member joined to the formed wire, the formed wire consisting of a single wire having a center wire and a side wire that are aligned with each other in the seat width direction and extend in the front-rear direction of the seat so that one end of each is connected to each other, the center wire and the side wire are arranged in this order from the center of the seat width direction of the seat cushion frame toward the outside, and each has a plurality of crank portions that are bent so as to be folded back alternately in a crank shape to one side and the other in the seat width direction, and the resin member has a deflection regulating portion that connects the plurality of crank portions so as to regulate the opening in the front-rear direction of the seat between three or more consecutively aligned crank portions formed on the side wire.

[0007] According to the first aspect of the present invention, the bending of the crank portion formed on the side wire is effectively restricted by the bending restriction portion made of the resin member. This makes it difficult for the side wire to sink downward when the load of a seated occupant is received on the surface of the side wire. As a result, the roll rigidity of the side portion of the seat cushion is appropriately increased.

[0008] A second aspect of the present invention is a cushion spring according to the first aspect of the present invention, wherein the resin member has a pad support surface that supports the seat cushion pad in a planar manner from the back side of the pad at a position higher than the plurality of crank portions.

[0009] According to the second aspect of the present invention, the pad support surface formed on the resin member can function as a support surface when the weight of a seated occupant is applied to the side portion of the seat cushion. This pad support surface is integrally provided with the side wire of the cushion spring, which is restricted in bending, and therefore can provide a stable support that is less likely to sink downward.

[0010] A third aspect of the present invention is the cushion spring according to the first or second aspect, wherein the deflection restricting portion extends so as to continuously connect all of the crank portions in the seat front-rear direction.

[0011] According to the third aspect of the present invention, the downward sinking of the side wire can be more effectively prevented, and as a result, the roll rigidity of the side portion of the seat cushion can be more appropriately increased.

[0012] A fourth invention of the present invention is a cushion spring according to the third invention, wherein the deflection control portion has an expansion portion that continuously or intermittently widens the connecting width in the seat width direction of the portion connecting each of the crank portions toward the rear of the seat, inward in the seat width direction.

[0013] According to the fourth aspect of the present invention, the hardness of the side portion of the seat cushion can be adjusted so that the roll stiffness is higher toward the rear of the seat where the seating pressure of the seated occupant is higher, and lower toward the front of the seat where the seating pressure of the seated occupant is lower. This makes it possible to improve both the comfort when seated and the roll stiffness.

[0014] A fifth aspect of the present invention is the cushion spring according to the fourth aspect, wherein the extension portion protrudes beyond the crank portion toward the inside in the seat width direction.

[0015] According to the fifth aspect of the present invention, the roll rigidity of the side portion of the seat cushion can be more appropriately increased in the region where the extension portion protrudes beyond the crank portion to the inside in the seat width direction.

[0016] A sixth aspect of the present invention is a cushion spring according to the first or second aspect of the present invention, wherein the formed wire is shaped symmetrically in the seat width direction and is provided in a pair symmetrically in the seat width direction relative to the seat cushion frame.

[0017] According to the sixth aspect of the present invention, the formed wire has a symmetrical shape, which makes it possible to easily form the formed wire. Also, it is relatively easy to increase the roll rigidity of both side portions of the seat cushion symmetrically in the seat width direction. [Brief description of the drawings]

[0018] [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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] 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 6. 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.

[0021] In addition, when a direction is indicated with "seat" added 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 6 will be appropriately referred to.

[0022] 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.

[0023] The seat cushion 1 is placed on the floor of an automobile (not shown). The seat cushion 1 has a seat cushion frame 2 that forms the framework of the seat cushion 1, a seat cushion pad 3 that covers the seat cushion frame 2 from above, and a seat cushion cover 4 that covers the seat cushion pad 3 from the pad surface side.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] Each formed wire 11 is formed such that its center wire 11A and side wire 11B are bent in a V shape in a side view. This V-shaped bend allows each formed wire 11 to make the rearward portion of the seat cushion pad 3 (see FIG. 1) that supports the ischial bones of a seated occupant (portion where the pad thickness is thicker downward) sink deeply downward.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Each of the flexure restricting portions 12A is not formed in a portion (not shown) that supports the seated occupant's ischium, but is formed at a position that is set back from the portion that supports the ischium to the outside in the seat width direction. Similarly, the connecting portion 12C is not formed in a portion (not shown) that supports the seated occupant's ischium, but is formed at a position that is set back from the portion that supports the ischium to the rear of the seat.

[0044] 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 ...

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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 are passed to fix each formed wire 11 in position within the molding die for the resin member 12.

[0052] 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.

[0053] 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, and a resin member (12) that is joined to the formed wire (11).

[0054] The formed wire (11) is made of a single wire 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 so that one end of each wire is connected to each other. The center wire (11A) and the side wire (11B) are arranged in this order from the center of the seat cushion frame (2) in the seat width direction to the outside.

[0055] The center wire (11A) and the side wire (11B) each have a plurality of crank portions (A1, B1) that are alternately bent in a crank shape in one direction and the other direction in the seat width direction. The resin member (12) has a flexure restriction portion (12A) that connects the plurality of crank portions (B1) so as to restrict the opening between the three or more consecutively arranged crank portions (B1) formed on the side wire (11B) in the front-rear direction of the seat.

[0056] According to the above-mentioned configuration, the bending of the crank portion (B1) formed on the side wire (11B) is effectively restricted by the bending restriction portion (12A) of the resin member (12). This makes it difficult for the side wire (11B) to sink downward when the load of a seated occupant is received on the surface of the side wire (11B). As a result, the roll rigidity of the side portion of the seat cushion (1) is appropriately increased.

[0057] The resin member (12) also has a pad support surface (12B) that supports the seat cushion pad (3) from the back side of the pad in a planar manner at a position higher than the crank portions (B1). According to the above configuration, the pad support surface (12B) formed on the resin member (12) can function as a support surface when the weight of a seated occupant is applied to the side portion of the seat cushion (1). This pad support surface (12B) is integrally provided with the side wire (11B) of the cushion spring (10) whose bending is restricted, so that it is possible to perform stable support that is unlikely to sink downward.

[0058] In addition, the deflection restricting portion (12A) extends so as to continuously connect all of the crank portions (B1) in the front-rear direction of the seat. With the above-described configuration, the downward sinking of the side wire (11B) can be more effectively restricted. As a result, the roll rigidity of the side portion of the seat cushion (1) can be more appropriately increased.

[0059] In addition, the deflection restricting portion (12A) has an expansion portion (A2) that continuously expands the width of the connection between the crank portions (B1) in the seat width direction toward the seat rear and inward in the seat width direction. According to the above configuration, the hardness of the side portions of the seat cushion (1) can be adjusted so that the roll stiffness is higher toward the seat rear where the seat pressure of the seated occupant is higher, and lower toward the seat front where the seat pressure of the seated occupant is lower. This makes it possible to improve both the comfort of sitting and the roll stiffness.

[0060] In addition, the extension portion (A2) extends beyond the crank portion (B1) to the inside in the seat width direction. According to the above configuration, the roll rigidity of the side portion of the seat cushion (1) can be more appropriately increased in the region where the extension portion (A2) extends beyond the crank portion (B1) to the inside in the seat width direction.

[0061] Moreover, the formed wires (11) are shaped symmetrically in the seat width direction, and are provided in a pair symmetrically with respect to the seat cushion frame (2) in the seat width direction. According to the above configuration, the formed wires (11) have a symmetrical shape, which makes it possible to easily form the formed wires (11). Also, it is relatively easy to increase the roll rigidity of both side portions of the seat cushion (1) symmetrically in the seat width direction.

[0062] 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.

[0063] 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.

[0064] 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 wire of the formed wire do not necessarily have to have shapes symmetrical to each other in the seat width direction.

[0065] 3. The pad support surface of the resin member may form the upper surface of the flexure restriction portion, or may form the upper surface of an area outside the flexure restriction portion. The flexure restriction portion may be configured to connect three or more consecutively arranged crank portions so as to restrict the opening between the crank portions in the front-rear direction of the seat. Therefore, the flexure restriction portion may be configured to directly connect only the frontmost crank portion and the last crank portion among the three or more consecutively arranged crank portions, and not to connect the crank portions between them.

[0066] The extension portion of the deflection restricting portion may extend the width of the joint between the crank portions in the seat width direction continuously toward the rear of the seat, or may extend the width intermittently. That is, the extension portion may include an area where the joint width is partially narrowed or constant. The deflection restricting portion may have a constant joint width over the entire area in the front-rear direction of the seat, or may have a shape that extends the joint width toward the front of the seat. [Explanation of symbols]

[0067] 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 10 Cushion spring 11 Formed Wire 11A Center Wire A1 Crank section 11B Side wire B1 Crank section B2 Vertical wire section 11C Front hook part 11D Rear hook part 12 Resin parts 12A Deflection control part A2 Extension 12B Pad support surface 12C Joint

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 formed wire bridged to the seat cushion frame in the front-rear direction of the seat; a resin member connected to the formed wire, The formed wire is composed of a single wire having a center wire and a side wire that are aligned in the seat width direction and extend in the seat front-rear direction so that one end of each wire is connected to each other, the center wire and the side wire are arranged in this order from the center of the seat cushion frame in a seat width direction toward the outside, and each of the center wires has a plurality of crank portions that are alternately folded back in a crank shape toward one side and the other side in the seat width direction, The resin member has a deflection restricting portion that connects between the crank portions, which are three or more consecutively arranged in front and behind the side wire, so as to restrict the opening between the crank portions in the front-rear direction of the seat.

2. 2. The cushion spring according to claim 1, The resin member has a pad support surface that supports the seat cushion pad from the back side of the pad in a planar manner at a position higher than the crank portions.

3. The cushion spring according to claim 1 or 2, The deflection restricting portion extends so as to continuously connect all of the crank portions in the front-rear direction of the seat.

4. 4. The cushion spring according to claim 3, The deflection regulating portion has an expansion portion that continuously or intermittently expands the connecting width in the seat width direction of the portion connecting each of the crank portions toward the rear of the seat, inward in the seat width direction.

5. 5. The cushion spring according to claim 4, The extension portion of the cushion spring extends beyond the crank portion toward the inside in the seat width direction.

6. The cushion spring according to claim 1 or 2, The formed wire has a shape symmetrical in the seat width direction, and a pair of cushion springs are provided symmetrical in the seat width direction with respect to the seat cushion frame.

Images