Seat cushion spring and vehicle seat

Abstract

To provide a seat cushion spring and a vehicle seat capable of easily achieving both a spring property and a vibration attenuation property and securing a vibration attenuation performance with preferable balance in right and left.SOLUTION: A plurality of spring members 30A, 30B, 30C are stretched across a front frame 24 and a rear frame 26. The plurality of spring members 30A, 30B, 30C are arranged in parallel in a seat width direction, and include a first spring member 30A arranged in an intermediate part of the seat width direction of a seat cushion 12 and second spring members 30B, 30C arranged respectively in both outside portions of the seat width direction of the seat cushion 12. A laterally stretched wire 50 extending along the seat width direction and in a curved shape in plan view has a longitudinal intermediate part fixed to the first spring member 30A, and longitudinal both side portions held by a holding member 54 fixed to the second spring members 30B, 30C such that the side portions are slidable relatively to own axial direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a seat cushion spring and a vehicle seat. [Background technology]

[0002] 1 to 5 of Patent Document 1 below discloses a technology relating to a seat damper device as an example of a structure for damping vibrations in a vehicle seat portion. Briefly, in this prior art, an S-spring stretched between a pair of front and rear fixed frames elastically supports the seat portion, and the rear end of a flexible elongated member extending in the front-rear direction of the seat is fixed to the rear end of the S-spring, with a vibration-damping damper provided on the front end of the elongated member. This prior art also includes a forced conforming means for forcibly making the elongated member conform to the bending deformation of the S-spring. The forced conforming means includes a tubular member through which the elongated member movably passes, and this tubular member is fixed to the S-spring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-282865 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above prior art, the vibration of the S-spring can be damped using a damper, but the structure is complicated. Also, in the prior art, the tension direction of the S-spring and the extension direction of the elongated member are the same, so the performance of one damper affects the spring characteristics of one S-spring, making it not necessarily easy to achieve both springiness and vibration damping.

[0005] Meanwhile, paragraph

[0041] of the above-mentioned Patent Document 1 discloses various modified examples, one of which is a modified example in which a long member is stretched across the S-spring, the S-spring is provided with forced conformity means having a tubular member through which the long member can move freely, and one end of the long member is fixed to the right or left end of the S-spring. However, this modified example leaves room for improvement in terms of ensuring a good balance of vibration damping performance between the left and right sides.

[0006] In consideration of the above, the present invention aims to provide a seat cushion spring and a vehicle seat that have a simple configuration, can easily achieve both spring properties and vibration damping properties, and can ensure vibration damping performance in a well-balanced manner on the left and right sides. [Means for solving the problem]

[0007] The seat cushion spring of the first embodiment is equipped with a plurality of spring members that are spanned between the front and rear of the frame of the seat cushion in the fore-and-aft direction of the seat to elastically support the pad material from the underside of the seat and are arranged in parallel in the seat width direction, the spring members being a first spring member arranged in the middle of the seat width direction of the seat cushion and second spring members arranged respectively on both outer sides of the seat width direction of the seat cushion, and a cross wire that extends along the seat width direction and in a curved shape when viewed from above, the cross wire having a longitudinal middle portion fixed to the first spring member and both longitudinal side portions held by resin or rubber retaining members fixed to the second spring member so as to be slidable relative to the axial direction of the cross wire.

[0008] According to a first aspect of the seat cushion spring, multiple spring members are stretched between the front and rear of the frame of the seat cushion along the seat front-rear direction to elastically support the padding from below the seat, and are arranged in parallel in the seat width direction. The multiple spring members include a first spring member arranged in a central portion of the seat cushion in the seat width direction and second spring members arranged on both outer sides of the seat cushion in the seat width direction. Furthermore, a lateral wire extending along the seat width direction has a longitudinal central portion fixed to the first spring member and both longitudinal side portions held by resin or rubber retaining members fixed to the second spring member so as to be slidable relative to the axial direction of the lateral wire. Therefore, when the multiple spring members expand and contract, the lateral wire slides relative to the retaining members on both sides of the seat cushion in the seat width direction, generating sliding resistance between the lateral wire and the retaining members, thereby enabling balanced left-right vibration damping.

[0009] Furthermore, since the lateral wire extends in a curved shape in a plan view, when the second spring member disposed on the outer side of the seat cushion in the seat width direction attempts to displace outward in the seat width direction, a load acts on the lateral wire to deform the curved shape so that it approaches a straight line in a plan view. The deformation resistance of the lateral wire at this time also damps vibration. Therefore, it is possible to improve vibration damping performance despite the simple structure.

[0010] Furthermore, with this seat cushion spring, the springiness in the vertical direction of the seat is adjusted by a spring member arranged along the front-to-rear direction of the seat, and the vibration damping property is adjusted by a horizontal wire arranged along the width direction of the seat and a retaining member fixed to the second spring member so that the horizontal wire can slide relatively, making it easy to achieve both springiness and vibration damping property.

[0011] The seat cushion spring of the second aspect is the same as that of the first aspect, and includes a frame-shaped connecting wire that extends along the seat width direction in a portion of the seat cushion that is rearward of the center of the seat in the seat longitudinal direction and is fixed to the multiple spring members, and the lateral wire is arranged forward of the connecting wire in the seat longitudinal direction.

[0012] According to the second aspect of the seat cushion spring, a frame-shaped connecting wire extending along the seat width direction in a portion of the seat cushion rearward of the center in the seat front-rear direction is fixed to a plurality of spring members, and a lateral wire is disposed forward of the connecting wire in the seat front-rear direction. Therefore, it is possible to use the lateral wire to damp vibrations while effectively suppressing a wobbling sensation caused when an inertial force in the seat width direction acts on an occupant seated on the seat cushion with the connecting wire.

[0013] The seat cushion spring of the third aspect is the same as that of the first or second aspect, except that the number of spring members is three, and the longitudinal middle portion of the cross wire is fixed to one of the first spring members.

[0014] According to the seat cushion spring of the third aspect, the number of spring members is three, and the longitudinal middle portion of the lateral wire is fixed to one first spring member, so that adjacent spring members are allowed to move toward and away from each other in the seat front-rear direction positions where the lateral wires are provided. Therefore, even with the lateral wires provided, a soft feeling when sitting can be ensured.

[0015] A fourth aspect of the vehicle seat comprises a seat cushion on which an occupant sits and a seat back that supports the back of the occupant seated on the seat cushion, and the seat cushion has a seat cushion spring of any one of the first to third aspects.

[0016] According to the vehicle seat of the fourth aspect, the back of an occupant seated on the seat cushion is supported by the seat back. The seat cushion has the seat cushion spring of any one of the first to third aspects, and therefore the effects of the seat cushion spring described above can be obtained. [Effects of the Invention]

[0017] As described above, the seat cushion spring and vehicle seat of the present invention have the excellent effect of easily achieving both springiness and vibration damping properties with a simple configuration, thereby ensuring balanced vibration damping performance between the left and right sides. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing a vehicle seat according to an embodiment of the present invention; [Figure 2] 1 is a perspective view showing a part of the internal structure of a seat cushion in a vehicle seat according to an embodiment of the present invention. [Figure 3] 1 is a plan view showing a part of the internal structure of a seat cushion in a vehicle seat according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] A vehicle seat 10 according to one embodiment of the present invention will be described below with reference to Figures 1 to 3. Note that arrows FR, UP, and RH, which are appropriately shown in each figure, respectively indicate the forward, upward, and rightward directions of the vehicle seat 10. When the following description uses front-to-back, up-down, left-to-right directions, these directions will be taken to refer to directions relative to the vehicle seat 10 unless otherwise specified.

[0020] (Configuration of the embodiment) 1 is a perspective view of a vehicle seat 10 according to this embodiment. The vehicle seat 10 includes a seat cushion 12 that forms a seating portion on which an occupant sits and supports the buttocks and thighs of the seated occupant, a seat back 14 that supports the back of the occupant seated on the seat cushion 12, and a headrest 16 that supports the head of the occupant seated on the seat cushion 12.

[0021] The seat cushion 12 includes a seat cushion pad 12P as a padding material (cushioning material) and a seat cushion frame 20 (see FIG. 2) as a frame that supports the seat cushion pad 12P from the underside of the seat. The seat cushion pad 12P is made of a foam such as urethane foam, and the surface of the seat cushion pad 12P is covered with a seat cushion skin 12E. Note that in FIG. 1, to make it easier to understand the configuration of the seat cushion 12, a portion of the seat cushion skin 12E is cut away to show the seat cushion pad 12P.

[0022] The seat back 14 includes a seat back pad 14P, which is a padding material (cushion material), and a seat back frame (not shown) that supports the seat back pad 14P from the rear side of the seat. The seat back pad 14P is made of a foam such as urethane foam, and the surface of the seat back pad 14P is covered with a seat back skin 14E. In FIG. 1, to make it easier to understand the configuration of the seat back 14, a portion of the seat back skin 14E is cut away to show the seat back pad 14P.

[0023] Fig. 2 shows a perspective view of a portion of the internal structure of the seat cushion 12 when no load is applied (when no one is seated). Fig. 3 shows a plan view of a portion of the internal structure of the seat cushion 12 in a state similar to that of Fig. 2. As shown in Figs. 2 and 3, the seat cushion frame 20 includes a pair of left and right side frames 22 that form both sides of the seat cushion 12 in the seat width direction (seat left-right direction) and are arranged with the seat front-rear direction as their longitudinal direction. The pair of left and right side frames 22 are formed, for example, by press-forming sheet metal.

[0024] At the front of the seat cushion frame 20, front end portions of the pair of left and right side frames 22 are connected to each other in the seat width direction by a front frame (front pan) 24. The front frame 24 is formed, for example, by press-forming a metal plate, and both end portions in the seat width direction are fixed to the front portions of the left and right side frames 22 by means of welding or the like. At the rear of the seat cushion frame 20, rear end portions of the pair of left and right side frames 22 are connected to each other in the seat width direction by a rear frame 26. The rear frame 26 is formed, for example, from a metal pipe, and both end portions in the seat width direction are connected to the rear end portions of the left and right side frames 22 by means of caulking or the like.

[0025] A seat cushion spring (also called a "cushion suspension mat") 28 is attached to the seat cushion frame 20. The seat cushion spring 28, together with the seat cushion frame 20, supports the seat cushion pad 12P (see FIG. 1) from below the seat. The seat cushion spring 28 includes a plurality of spring members 30A, 30B, 30C (three in this example), a connecting wire 40, and a crossover wire 50.

[0026] The plurality of spring members 30A, 30B, and 30C are spanned between the front frame 24 (the front portion of the seat cushion frame 20) and the rear frame 26 (the rear portion of the seat cushion frame 20) in the seat front-rear direction. The plurality of spring members 30A, 30B, and 30C elastically support the seat cushion pad 12P (see FIG. 1) from the seat lower side and are arranged in parallel in the seat width direction. The plurality of spring members 30A, 30B, and 30C include a first spring member 30A arranged in a middle portion of the seat cushion 12 in the seat width direction, and second spring members 30B and 30C arranged on both outer sides of the seat cushion 12 in the seat width direction. In the following description, the first spring member 30A and the second spring members 30B and 30C will be referred to as spring members 30 when there is no need to distinguish between them. The spring members 30 are made of metal and are manufactured by bending a linear spring material.

[0027] One end 32 of the spring member 30 is attached by being engaged from the left and right direction to the rear end of the front frame 24. In addition, adjacent portions of the multiple spring members 30 in the seat width direction are connected to each other in the seat width direction at predetermined positions near one end 32 by connecting portions 25 made of resin.

[0028] The rear frame 26 is provided with a resin base member 27 whose length in the seat width direction is shorter than the axial length of the rear frame 26. The other ends 34 of the spring members 30 are integrally attached to both end portions (one end and the other end) and the center of the base member 27 in the seat width direction.

[0029] The intermediate portion of the spring member 30 in the front-rear direction has a wavy portion 36 that is bent alternately into a U-shape in plan view that opens to one side in the horizontal direction perpendicular to the bridge direction and then into a U-shape in the opposite direction. The shape and dimensions of the wavy portion 36 of each spring member 30 are set appropriately. The spring member 30 of this embodiment is an element that can be understood as a formed wire.

[0030] A connecting wire 40 extending along the seat width direction is fixed to the underside of the corrugated portions 36 of the multiple spring members 30 in a portion of the seat cushion 12 rearward of the seat front-rear center in the seat front-rear direction. The connecting wire 40 is made of metal and functions as a stabilizer that synchronizes the multiple spring members 30. In this embodiment, the connecting wire 40 is formed into a frame shape in a plan view with the seat width direction as the longitudinal direction by connecting both ends of a single wire bent into a substantially rectangular shape with a crimping member 42. The connecting wire 40 has a pair of front and rear horizontal extending portions 40A extending in the seat width direction and a pair of left and right vertical extending portions 40B extending in the seat front-rear direction. The crimping member 42 is made of, for example, a metal plate bent into a substantially C-shaped cross section, and the both ends of the wire are joined by crimping the crimping member 42.

[0031] The front and rear horizontal extension portions 40A of the connecting wire 40 are fixed to each of the wave-shaped portions 36 using clip members 44. The clip members 44 are made of, for example, metal and are bent to have a substantially C-shaped cross section. The multiple spring members 30 are connected to each other in the seat width direction by the connecting wires 40 fixed by the clip members 44.

[0032] For example, a plurality of bent portions 40V (here, two on the left and right) are formed on each of the front and rear horizontally extending portions 40A of the connecting wire 40. Each bent portion 40V is bent into a substantially V-shape in plan view. The left and right bent portions 40V are disposed between the spring members 30 adjacent to each other in plan view.

[0033] A lateral wire 50 is disposed forward of the connecting wire 40 in the seat longitudinal direction. The lateral wire 50 is made of metal and extends in a curved shape in a plan view along the seat width direction. To further explain, the lateral wire 50 is disposed, for example, in a curved shape (arcuate shape) convex toward the rear of the seat in a plan view, and is symmetrical with respect to a center line (not shown) of the seat cushion 12 in the seat width direction in a plan view. The lateral wire 50 is attached to the corrugated portions 36 of the multiple spring members 30 and is disposed so as to pass below the corrugated portions 36 of the multiple spring members 30. A longitudinal intermediate portion of the lateral wire 50 is fixed to a single first spring member 30A by a fixing member 52. Both longitudinal side portions of the lateral wire 50 are held by holding members 54 fixed to the second spring members 30B and 30C so as to be slidable relative to each other in the axial direction.

[0034] The fixing member 52 and the holding member 54 are both made of resin. The fixing member 52 is fixed to the center of the seat cushion 12 in the seat width direction. The wavy portions 36 of the multiple spring members 30 are fixed to the fixing member 52 so as to penetrate the fixing member 52 in the seat width direction, and the horizontal wire 50 is fixed to the fixing member 52 so as to penetrate the fixing member 52. The left and right holding members 54 are arranged at positions symmetrical to each other with respect to the center line (not shown) of the seat cushion 12 in the seat width direction, and have symmetrical shapes to each other. The wavy portions 36 of the multiple spring members 30 are fixed to the holding member 54 so as to penetrate the fixing member 52 in the seat width direction, and the horizontal wire 50 is held to the holding member 54 so as to be slidable (relatively movable) relative to the holding member 54 in the axial direction. The outer peripheral surface of the portion of the horizontal wire 50 held by the holding member 54 is in surface contact with the holding member 54. For example, the holding member 54 has elasticity that allows it to deform in response to deformation of the horizontal wire 50 in a direction intersecting its axial direction.

[0035] (Actions and Effects of the Embodiments) Next, the operation and effects of this embodiment will be described.

[0036] In this embodiment, the lateral wire 50 extending along the seat width direction has a longitudinal middle portion fixed to the first spring member 30A, and both longitudinal side portions held by resin holding members 54 fixed to the second spring members 30B, 30C so as to be slidable relative to the axial direction of the lateral wire 50. Therefore, when the plurality of spring members 30 expand and contract due to vibrations transmitted to the seat cushion 12 while the vehicle is traveling, the lateral wire 50 slides relative to the holding members 54 on both sides of the seat cushion 12 in the seat width direction, thereby generating sliding resistance (frictional force) between the lateral wire 50 and the holding members 54, thereby making it possible to damp vibrations in a balanced manner on the left and right (obtaining vibration damping characteristics that are substantially symmetrical on the left and right).

[0037] Furthermore, since the lateral wires 50 extend in a curved shape in a plan view, when an occupant is seated (when a high load acts on the seat cushion 12), the second spring members 30B, 30C arranged on the outer portions of the seat cushion 12 in the seat width direction tend to be displaced outward in the seat width direction (see the direction of arrow A in FIG. 3 ) due to the load from the buttocks of the seated occupant, and a load acts on the lateral wires 50 to deform the curved shape so that it approaches a straight line in a plan view. Vibrations are also damped by the deformation resistance force of the lateral wires 50 at this time. Therefore, vibration damping performance can be improved despite the simple structure.

[0038] Furthermore, in this embodiment, the springiness of the seat in the vertical direction is adjusted by the spring member 30 arranged along the front-to-rear direction of the seat, and the vibration damping property is adjusted by the horizontal wire 50 arranged along the width direction of the seat and the retaining member 54 fixed to the second spring members 30B, 30C and allowing the horizontal wire 50 to slide relative to it, so that it is easy to achieve both springiness and vibration damping property.

[0039] In this embodiment, a frame-shaped connecting wire 40 extending along the seat width direction in a portion of the seat cushion 12 that is rearward of the center in the seat front-rear direction is fixed to the plurality of spring members 30, and a lateral wire 50 is disposed forward of the connecting wire 40 in the seat front-rear direction. Therefore, the connecting wire 40 effectively suppresses the feeling of wobbling when an inertial force in the seat width direction acts on an occupant seated on the seat cushion 12, while the lateral wire 50 can dampen vibrations.

[0040] In this embodiment, the number of spring members 30 is three, and the longitudinal middle portion of the lateral wire 50 is fixed to one first spring member 30A, so that adjacent spring members 30 are allowed to move toward and away from each other in the seat front-rear direction positions where the lateral wires 50 are provided. Therefore, even when the lateral wires 50 are provided, a soft feeling when seated can be satisfactorily ensured.

[0041] As described above, the vehicle seat 10 having the seat cushion spring 28 of this embodiment has a simple configuration that easily achieves both springiness and vibration damping properties, making it possible to ensure balanced vibration damping performance on the left and right sides.

[0042] Furthermore, according to the configuration of this embodiment, even if the thickness of the seat cushion pad 12P (see FIG. 1) as the pad material is thin, it is possible to exhibit good vibration damping performance. In comparison with the comparative structure, in the comparative structure in which the pad material is placed on the cushion pan without providing a spring member in order to maximize the damping performance of the pad material, the pad material must be made thick to prevent the occupant from feeling like they are hitting the bottom. However, in this embodiment, since the spring member 30 is used and the horizontal wire 50 is provided, even if the thickness of the seat cushion pad 12P (see FIG. 1) is thin, it is possible to prevent the occupant from feeling like they are hitting the bottom and to exhibit good vibration damping performance.

[0043] Furthermore, for example, if a comparative structure in which a padding material is placed on the cushion pan without providing a spring member is adopted, the cushion pan would have a large mass, which would be disadvantageous in terms of weight reduction, but this embodiment does not adopt such a structure, which is advantageous in terms of weight reduction. Furthermore, the structure of this embodiment is also advantageous in terms of achieving cost reduction compared to the comparative structure.

[0044] Furthermore, when the configuration of this embodiment is adopted, the frictional force between the holding member 54 and the horizontal wire 50 can be adjusted by changing the diameter of the horizontal wire 50.

[0045] (Supplementary explanation of the embodiment) In the above embodiment, the holding member 54 is made of resin, but the holding member 54 may be made of rubber.

[0046] In the above embodiment, the number of spring members 30 is three, and the longitudinal middle portion of the horizontal wire 50 is fixed to one first spring member 30A, which is a preferable configuration, but as a modification of the above embodiment, the number of spring members 30 may be four, and the longitudinal middle portion of the horizontal wire 50 is fixed to two first spring members. The number of spring members 30 may be five or more.

[0047] In addition, in the above embodiment, as an example, the horizontal wire 50 is arranged so that it is curved convexly toward the rear side of the seat when viewed in a plane, but as a variation of the above embodiment, the horizontal wire 50 may be arranged so that it is curved convexly toward the front side of the seat when viewed in a plane.

[0048] In the above embodiment, the connecting wire 40 is provided in the seat cushion 12, and this configuration is preferable, but as a modification of the above embodiment, a configuration in which the connecting wire 40 is not provided may also be adopted.

[0049] In addition, in the above embodiment, the lateral wire 50 is positioned forward in the front-rear direction of the seat from the connecting wire 40, which is provided in a portion of the seat cushion 12 that is rearward of the center of the seat in the front-rear direction. However, as a variation of the above embodiment, a configuration can also be adopted in which the connecting wire (40) is provided in a portion of the seat cushion (12) that is forward of the center of the seat in the front-rear direction of the seat, and the lateral wire (50) is positioned rearward of the connecting wire (40) in the front-rear direction of the seat.

[0050] The above-described embodiment and the above-described modifications can be implemented in appropriate combinations.

[0051] The above describes one example of the present invention, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0052] 10 Vehicle seats 12 seat cushions 12P seat cushion pad (pad material) 14 Seat back 20 Seat cushion frame (seat cushion frame) 28 Seat cushion spring 30 Spring member 30A First spring member 30B, 30C Second spring member 40 connecting wire 50 Horizontal wire 54 Retaining member

Claims

1. a plurality of spring members that are arranged in parallel in the seat width direction and that are spanned between the front and rear portions of the frame of the seat cushion along the seat front-rear direction, elastically supporting the pad material from the lower side of the seat, and that include a first spring member that is arranged in a middle portion of the seat cushion in the seat width direction, and second spring members that are respectively arranged on both outer portions of the seat cushion in the seat width direction; a horizontal wire extending in a curved shape in a plan view along the seat width direction, with a longitudinal middle portion fixed to the first spring member and longitudinal both side portions held by a resin or rubber holding member fixed to the second spring member so as to be relatively slidable in its axial direction; A seat cushion spring.

2. a frame-shaped connecting wire extending along the seat width direction in a portion of the seat cushion rearward of a center in the seat front-rear direction and fixed to the plurality of spring members; The seat cushion spring according to claim 1 , wherein the horizontal wire is disposed forward of the connecting wire in the seat front-rear direction.

3. 2. The seat cushion spring according to claim 1, wherein the number of the spring members is three, and a longitudinal intermediate portion of the horizontal wire is fixed to one of the first spring members.

4. A seat cushion on which an occupant sits; a seat back that supports the back of an occupant seated on the seat cushion; Equipped with A vehicle seat, wherein the seat cushion comprises the seat cushion spring according to claim 1.

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