seat cushion

Abstract

Seat cushion, with: a seat cushion (3) which is attached to a seat cushion frame (2) and covered with a seat cushion cover (4), a locking hook (41) having a J-shaped cross-section and, in a sectional view, a curved section (42) and a straight section (43), wherein the straight section (43) is positioned and attached to an inner surface of an end section (4T) of the seat cushion cover (4) such that the straight section (43) is positioned closer to an edge (4T1) of the end section (4T) of the seat cushion cover (4) than the curved section (42), and the end section (4T) of the seat cushion cover (4) extends around the curved section (42) of the locking hook (41) from the outside, wherein the seat cushion frame (2) has wire elements (31, 32, 33, 34, 35, 36) and the wire elements (31, 32, 33, 34, 35, 36) have securing sections (K) which serve to secure the curved section (42) of the securing hook (41), which extends continuously along the securing sections (K) of the wire elements (31, 32, 33, 34, 35, 36), in order to secure the seat cushion cover (4) by hooking the curved section (42) onto the securing sections (K), the securing section (K) of at least one (31,32) of the wire elements (31,32,33,34,35,36) has a corner section (31C1,33C1) which, in a top view of the seat cushion frame (2), extends such that it runs transversely to the seat cushion frame (2) outwards at the same time towards the rear (Rr) of the seat cushion frame (2), and the corner section (31C1,33C1) of the at least one wire element (31,32) is bent in a triangular shape towards the top of the seat cushion frame (2) in such a way that the curved section (42) of the safety hook (41) is not secured to the safety section (K) of the at least one wire element (31,32) in the upwardly bent area.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a seat cushion in which a seat cushion pad is mounted on a seat cushion frame and covered with a seat cushion cover, and a securing hook attached to an end portion of the seat cushion cover is secured to a wire member(s) of the seat cushion frame, wherein the wire member has corner portions bent in a plan view, and the securing hook extends continuously along securing portions of the wire member(s). BACKGROUND OF THE INVENTION

[0002] As described in JP H11-89663 A, the wire element of the above-mentioned type of seat cushion has corner portions that are bent in plan view. Therefore, it is conceivable to also bend (deform) the securing hook so that it becomes parallel to the bent corner portions.

[0003] However, in this case, as in the Fig. 3A, Fig. 3B and Fig. 4, the opening width b of a curved portion 42 of each such corner portion 41A of the securing hook 41 is smaller than the opening width a of each of the non-corner portions (straight portions of the securing hook 41). This is a phenomenon that the curved portion 42 is deformed due to the difference between the circumferential length of an inner opening edge K2 and an outer opening edge K1 of the curved portion 42 in a sectional view, and the distance between the inner opening edge K2 and the outer opening edge K1 is therefore reduced. As a result, it becomes difficult to secure the corner portions of the securing hook 41 to the respective corner portions of the wire member, which deteriorates the workability of the work of securing the securing hook 41 to the wire member.

[0004] A conventional means for solving this problem is a first technique of using multiple wire elements, each having only one straight section, i.e., no curved section. A second technique is to form a cut to avoid interference with a corresponding corner portion of the wire element in each corner portion of the safety hook.

[0005] JP H10-248686 A discloses that a bent part to be bent into an almost inverted U-shape in the insertion direction (upward) of an engaging tool is integrally formed in an appropriate length at the lower part of an engaging wire at a nearly middle part in the longitudinal direction. The bent part can be formed simultaneously when a straight wire is bent into a lateral rectangular frame shape to manufacture the engaging wire. A trim strip is placed on a cushion frame, and the engaging tool is inserted from below into the lower part of the engaging wire to engage the trim strip by pulling the trim strip downward. Although the rotational force acts on the engaging tool by the pulling reaction force of the trim strip, the engaging tool is not rotated because the rotation of the engaging tool is stopped by the bent part.

[0006] JP 2014 - 100 992 A discloses a seat device comprising: a seat back frame; a pair of left and right cushion side frames respectively disposed at left and right portions of a lower part of the seat back frame; a pair of left and right support frames respectively supporting the left and right cushion side frames; connecting members that move the left and right cushion side frames up and down relative to the left and right support frames; and a surface covering material fastening member that extends from one of the left and right cushion side frames in a downward direction to a position overlapping with the lateral side of the connecting member and extends in a longitudinal direction to fasten a surface covering material covering a surface of a cushion attached to the left and right cushion side frames.A relief part that does not overlap with a rotary shaft on the other end part side of the connecting member in an axial direction is formed on the surface covering material fixing member.

[0007] JP S57 - 81 670 U discloses an improvement in the structure for fixing the lower edge of a seat cover, which is the seat cover of a vehicle seat, to a seat frame and makes it possible to design the shape of the lower edge with a high degree of freedom.

[0008] JP 2012-6495A discloses that a center wire, a right side wire, and a left side wire are included. The center wire is formed by bending into a U-shaped letter, and both edges are fixed near a front center of the pillow frame so that an opening direction can face upward. One end of the right side wire is fixed to a right side of the pillow frame, and the other end is bent upward at an obtuse angle and welded to a right-side folding part of the center wire at an overlapping position. One end of the left side wire is fixed to a left side of the pillow frame, and the other end is bent upward at an obtuse angle and welded to a left-side folding part of the center wire at an overlapping position. SUMMARY OF THE INVENTION

[0009] However, in the first technique, the number of wire elements and the number of wire points are increased, which means an increase in the number of parts and the number of manufacturing steps.

[0010] In the second technique, the formation of cuts in the securing hook reduces the strength of the securing hook, resulting in the problem that the seat cushion cover tends to wrinkle near the corner portions of the securing hook.

[0011] An object of the present invention is to provide a seat cushion which can reduce the number of parts and the number of manufacturing steps and can reduce the tendency of a seat cushion cover to wrinkle, although it is configured to facilitate the work of securing a securing hook to wire members.

[0012] The invention provides a seat cushion in which a seat cushion cover is mounted on a seat cushion frame and covered with a seat cushion cover, a securing hook attached to an end portion of the seat cushion cover is secured to wire elements of the seat cushion frame, at least one of the wire elements has a corner portion which is bent in a plan view, and the securing hook extends continuously along securing portions of the wire elements, wherein: the corner portion of the at least one of the wire elements is bent so as to be convex upwards, so that a corresponding corner portion of the securing hook is not secured to the corner portion of the at least one of the wire elements.

[0013] In this seat cushion, the corner portion of the at least one wire element is bent to be upwardly convex, thereby escaping the corresponding corner portion of the securing hook. Therefore, the corner portion of the securing hook does not need to be secured to the corner portion of the at least one wire element that has a narrow opening. Consequently, only the straight portions of the securing hook need be secured to the straight portions of the wire elements, thereby improving the workability of securing the securing hook to the wire elements.

[0014] Since the individual wire elements do not have to be divided into two elements, each with a straight lower wire section, the number of parts and the number of manufacturing steps can be reduced.

[0015] Furthermore, since it is not necessary to form a cut in the corner portion of the securing hook to prevent interference with the corner portion of the at least one wire member, the securing hook can be prevented from having reduced strength. Therefore, the portion of the seat cushion cover sewn to the securing hook at the position close to its corner portion can be tightly stretched. As a result, wrinkling of the seat cushion cover can be prevented even though the corner portion of the securing hook is not secured to the corner portion of the at least one wire member.

[0016] The above-mentioned seat cushion is preferably such that the corner portion of the at least one of the wire members is bent to assume a triangular shape which is convex upward.

[0017] In this seat cushion, the corner portion of the at least one wire element is inclined upward, allowing it to escape upward from the corner portion of the securing hook, thereby gradually disengaging from the securing hook. This makes it possible to smoothly perform the work of securing the securing hook to the wire elements, while improving the workability of the securing hook.

[0018] The seat cushion specified above is preferably such that: the safety hook has a J-shaped cross-section and is constructed in a sectional view from a curved section and a straight section, a back surface of the straight portion is placed on an inside surface of the end portion of the seat cushion cover such that the straight portion is positioned closer to an edge of the seat cushion cover than the curved portion, the straight section is attached to the end section of the seat cushion cover, the end section of the seat cushion cover is wound from the outside onto the securing sections of the wire elements and the curved section of the securing hook is secured to the securing sections of the wire elements, and an outer end surface, with respect to the circumferential direction, of the curved portion of the convex corner portion is received by the at least one wire element, thereby preventing the securing hook from rotating about the axes of the wire elements.

[0019] In this seat cushion, the end portion of the seat cushion cover is wound from the outside onto the securing portions of the wire elements, and the curved portion of the securing hook is secured to the securing portions of the wire elements. The outer end surface of the curved portion, with respect to the circumferential direction, is received by the convex corner portion of the at least one wire element, thereby preventing the securing hook from rotating around the axes of the wire elements. This prevents the securing hook from being released, i.e., disengaged from the wire elements, and the seat cushion cover from wrinkling.

[0020] The above-mentioned seat cushion is preferably such that an outer end, with respect to the circumferential direction, of the curved portion is formed with a projecting part projecting outward in the radial direction from the curved portion.

[0021] In this seat cushion, a side surface of the protrusion portion is received by the convex corner portion of the at least one wire element, thereby preventing the locking hook from rotating about the axes of the wire elements. Since the side surface of the protrusion portion is received by the convex corner portion of the at least one wire element, the locking hook can be more reliably prevented from rotating about the axes of the wire elements.

[0022] The invention makes it possible to provide a seat cushion that can reduce the number of parts and the number of manufacturing steps and can reduce the tendency of a seat cushion cover to wrinkle, although it is configured to facilitate the work of securing a securing hook to wire members. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view of a seat cushion of a rear seat for a motor vehicle. Fig. Figure 2A is a sectional view along the line AA in Fig. 1, Fig. 2B is a sectional view showing how a non-corner portion (straight securing hook portion) of a securing hook is secured to a non-corner portion (straight wire member portion) of a wire member, and Fig. 2C is a sectional view of a corner portion of the safety hook and a corner portion of the wire element. Fig. 3A is a plan view of a portion of a seat cushion frame and Fig. Figure 3B is an enlarged view of Part V of Fig. 3A. Fig. Figure 4 is a sectional view comparing the corner portion and the non-corner portion of the safety hook. Description of the symbols 2 seat cushion frame 3 seat cushion cover 4 seat cushion cover 4T end section of seat cushion cover 4T1: Edge of seat cushion cover 21: loop-shaped pipe element 21A: right pipe section 21B: left pipe section 21F: front pipe section 21R: rear pipe section 22: Springs 30: Support bracket 31: Wire element (first wire element) 31A: left wire section 31B: right wire section 31B1: upper end section 31C: lower wire section 31C1: Corner section of wire element (corner section of first wire element) 32: second wire element 32A: left wire section 32A1: upper end section 32B: right wire section 32B1: upper end section 32C: lower wire section 33: Wire element (third wire element) 33A: right wire section 33B: left wire section 33B1: upper end section 33C1: Corner section of wire element (corner section of third wire element) 34: fourth wire element 34C: Wire section 34C1: convex triangular shape 35: fifth wire element 35C: Wire section 36: sixth wire element 36C: Wire section 36C1: convex triangular shape 41: Safety hook 41A: Corner section of safety hook 41B: Corner section of safety hook 42: Curved section 42A: Projection part 42A1: Circumferential outer end surface of curved portion (side surface of protrusion part) 43: Straight section a, b: opening width A: Seam section B: Direction Fr: Front of the seat K: Security sections K1: outer opening edge K2: inner opening edge Rr: Back of the seat DETAILED DESCRIPTION OF THE INVENTION

[0023] An embodiment for carrying out the present invention will be described below with reference to the drawings.

[0024] Fig. 1 is an exploded perspective view of a seat cushion of a rear seat used in a motor vehicle. The seat cushion is provided with a seat cushion frame 2, a seat cushion support 3 (see Fig. 2A), which is attached to the seat cushion frame 2, and a seat cushion cover 4 (cover element), which covers the seat cushion support 3.

[0025] As in the Fig. 1, Fig. 2A and Fig. 2B, a resin securing hook 41 is sewn onto and secured to an end portion 4T of the seat cushion cover 4. The securing hook 41 is connected to a first wire element 31 to a sixth wire element 36 (see Fig. 1) of the seat cushion frame 2. Structure of the seat cushion frame 2

[0026] As in Fig. 1, the seat cushion frame 2 has a rectangular (elongated), loop-shaped tube element 21, which is constructed from a front tube section 21F, a rear tube section 21R, a left tube section 21B and a right tube section 21A. In Fig. 1, the symbols Fr and Rr indicate the front and back of the seat respectively.

[0027] A plurality of S-shaped springs 22 for absorbing a shock are stretched between the front tube portion 21F and the rear tube portion 21R so as to be spaced apart from each other in the longitudinal direction of the seat.

[0028] The first wire member 31 to the sixth wire member 36 are connected to a left end portion, a central portion, and a right end portion of the front pipe portion 21F, the right pipe portion 21A, the rear pipe portion 21R, and the left pipe portion 21B, respectively. Structure of the first wire element 31

[0029] As in Fig. 1, the first wire member 31 is configured such that the two upper ends of a wide, U-shaped wire member are welded and fixed to the left end portion of the front tube portion 21F. An upper end portion 31B1 of a right wire portion 31B of the first wire member 31 is bent toward the rear side Rr of the seat and supported from below by a support bracket 30 projecting from the front tube portion 21F toward the front side Fr of the seat.

[0030] As in the Fig. 1, Fig. 3A and Fig. As shown in Fig. 3B, in the first wire member 31, a lower wire portion 31C connecting the lower ends of a left wire portion 31A and the right wire portion 31B has a corner portion 31C1 bent in a plan view. The corner portion 31C1, which is a left portion of the lower wire portion 31C, is inclined to the rear side Rr of the seat when the position in the longitudinal direction of the seat is directed outward.

[0031] The corner portion 31C1 of the lower wire portion 31C is bent upward to assume a convex triangular shape such that a corner portion 41A (described later; see Fig. 1, Fig. 3A and Fig. 3B) of the safety hook 41 at the corner section 31C1 of the lower wire section 31C is not secured there (see Fig. 2C). Structure of the second wire element 32

[0032] The second wire member 32 is configured such that the two upper ends of a wide, U-shaped wire member are welded and fixed to the central portion of the front tubular portion 21F. An upper end portion 32A1 of a left wire portion 32A and an upper end portion 32B1 of a right wire portion 32B of the second wire member 32 are bent toward the rear side Rr of the seat and supported from below by respective support brackets 30 projecting from the front tubular portion 21F toward the front side Fr of the seat. A lower wire portion 32C connecting the lower ends of the left wire portion 32A and the right wire portion 32B is straight. Structure of the third wire element 33

[0033] The third wire member 33 is symmetrical to the first wire member 31 with respect to the vertical center line. An upper end portion 33B1 of a left wire portion 33B of the third wire member 33 is bent toward the rear side Rr of the seat and supported from below by a support bracket 30 projecting from the front tube portion 21F toward the front side Fr of the seat.

[0034] As in Fig. As shown in Fig. 1, in the third wire member 33, a lower wire portion 33C connecting the lower ends of the left wire portion 33B and a right wire portion 33A has a corner portion 33C1 that is bent in a plan view. The corner portion 33C1, which is a right portion of the lower wire portion 33C, is inclined to the rear side Rr of the seat when the position in the longitudinal direction of the seat is directed outward.

[0035] The corner portion 33C1 of the lower wire portion 33C is bent upward to assume a convex triangular shape such that a corner portion 41B (described later; see Fig. 1) of the securing hook 41 is not secured to the corner portion 33C1 of the lower wire portion 33C there. Structures of the fourth wire element 34 to sixth wire element 36

[0036] As in Fig. As shown in FIG. 1, the fourth wire member 34 and the sixth wire member 36, which are connected to the right tube portion 21A and the left tube portion 21B, respectively, have wire portions 34C and 36C extending in the front-rear direction of the seat. Furthermore, the wire portions 34C and 36C are bent upward to form convex triangular shapes 34C1 and 36C1, respectively. The fifth wire member 35, which is connected to the rear tube portion 21R, has wire portions 35C extending in the longitudinal direction of the seat.

[0037] The lower wire portions 31C-33C from the first wire member 31 to the third wire member 33, the wire portions 34C and 36C of the fourth wire member 34 and the sixth wire member 36, and the wire portions 35C (extending in the longitudinal direction of the seat) of the fifth wire member 35 are securing portions K to which the securing hook 41 is secured. Structure of the safety hook 41

[0038] As in Fig. 1, the securing hook 41 extends continuously along the securing sections K. This means that the securing hook 41 extends the corner section 41A (see Fig. 1, Fig. 3A and Fig. 3B), which corresponds to the lower wire section 31C of the first wire element 31, and the corner section 41B (see Fig. 1), which corresponds to the lower wire portion 33C of the third wire element 33.

[0039] As in the Fig. As shown in FIGS. 2A-2C, the securing hook 41 has a J-shaped cross section and is constructed, in a sectional view, of a curved portion 42 and a straight portion 43. The back surface of the straight portion 43 is placed on the inside surface of the end portion 4T of the seat cushion cover 4 such that the straight portion 43 is positioned closer to the edge 4T1 of the seat cushion cover 4 than the curved portion 42. The straight portion 43 is sewn and fixed to the end portion 4T. Reference symbol A denotes a seam portion.

[0040] The end portion 4T of the seat cushion cover 4 is wound from the outside onto the securing portions K from the first wire element 31 to the sixth wire element 36. The curved portion 42 of the securing hook 41 is adapted to and secured to the securing portions K.

[0041] As in Fig. 2C, the outer end, with respect to the circumferential direction, of the curved portion 42 is formed with a protrusion part 42A that protrudes outward in the radial direction from the curved portion 42. A side surface 42A1 (which is the same surface as the circumferential outer end surface of the curved portion 42) of the protrusion part 42A is contacted by the corner portion 31C1 (see Fig. 1) of the lower wire portion 31C of the first wire element 31, the corner portion 33C1 of the lower wire portion 33C of the third wire element 33, the convex portion 34C1 of the fourth wire element 34, and the convex portion 36C1 of the sixth wire element 36.

[0042] With the configuration indicated above, a rotation of the safety hook 41 around the axes of the wire elements 31, 33, 34 and 36 (ie a rotation in the direction indicated by the arrow B in Fig. 2A). This prevents the safety hook 41 from being released, ie, from being disengaged from the wire elements 31, 33, 34, and 36, and from the seat cushion cover 4 from being folded.

[0043] When configured as described above, the seat cushion according to the embodiment offers the following advantages: (1) As in Fig. 2C, the corner portion 31C1 of the lower wire portion 31C of the first wire member 31 and the corner portion 33C1 of the lower wire portion 33C of the third wire member 33 are not engaged with the corner portions 41A and 41B of the securing hook 41. Therefore, the corner portions 41A and 41B of the securing hook 41 do not need to be secured to the corner portion 31C1 of the lower wire portion 31C of the first wire member 31 and the corner portion 33C1 of the lower wire portion 33C of the third wire member 33.

[0044] As a result, it suffices that only the straight portions of the securing hook 41 are secured to the straight portions of the lower wire portions 31C and 33C of the first wire member 31 and the third wire member 33, thereby improving the operability of the work of securing the securing hook 41 to the lower wire portions 31C and 33C.

[0045] Since the individual lower wire sections 31C and 33C do not need to be divided into two straight sections, the number of parts and the number of manufacturing steps can be reduced.

[0046] Furthermore, since it is not necessary to form cuts in the corner portions 41A and 41B of the securing hook 41 for preventing interference between the corner portions 31C1 and 33C1 of the first wire member 31 and the third wire member 33, the securing hook 41 can be prevented from having reduced strength. Therefore, the portions of the seat cushion cover 4 sewn to the securing hook 41 at the positions close to the corner portions 41A and 41B thereof can be firmly stretched. As a result, wrinkling of the seat cushion cover 4 can be prevented even though the corner portions 41A and 41B of the securing hook 41 are not secured to the corner portions 31C1 and 33C1 of the first wire member 31 and the third wire member 33. (2) Since the corner portions 31C1 and 33C1 of the lower wire portions 31C and 33C of the first wire member 31 and the third wire member 33 are bent upward to form convex triangular shapes, the corner portions 31C1 and 33C1 are inclined upward. Therefore, the corner portions 31C1 and 33C1 can escape upward from the corner portions 41A and 41B of the securing hook 41, gradually disengaging from the securing hook 41. This makes it possible to smoothly perform the work of securing the securing hook 41 to the lower wire portions 31C and 33C, thereby improving its workability.

Claims

[1] Seat cushion, with: a seat cushion pad (3) mounted on a seat cushion frame (2) and covered with a seat cushion cover (4), a securing hook (41) having a J-shaped cross-section and having, in a sectional view, a curved portion (42) and a straight portion (43), wherein the straight portion (43) is placed and fastened to an inside surface of an end portion (4T) of the seat cushion cover (4) such that the straight portion (43) is positioned closer to an edge (4T1) of the end portion (4T) of the seat cushion cover (4) than the curved portion (42), and the end portion (4T) of the seat cushion cover (4) extends from the outside around the curved portion (42) of the securing hook (41), wherein the seat cushion frame (2) has wire elements (31, 32, 33, 34, 35, 36) and the wire elements (31, 32, 33, 34, 35, 36) have securing sections (K) which serve to secure the curved section (42) of the securing hook (41), which extends continuously along the securing sections (K) of the wire elements (31, 32, 33, 34, 35, 36), in order to secure the seat cushion cover (4) by hooking the curved section (42) onto the securing sections (K), the securing section (K) of at least one (31, 32) of the wire elements (31, 32, 33, 34, 35, 36) has a corner section (31C1, 33C1) which, in a plan view from above onto the seat cushion frame (2), extends in such a way that it runs transversely to the seat cushion frame (2) outwards and simultaneously to the rear side (Rr) of the seat cushion frame (2), and the corner section (31C1, 33C1) of the at least one wire element (31, 32) is bent in a triangular shape towards the top of the seat cushion frame (2) in such a way that the curved section (42) of the securing hook (41) is not secured to the securing section (K) of the at least one wire element (31, 32) in the upwardly bent section. [2] The seat cushion according to claim 1, wherein an outer end surface (42A1), with respect to the circumferential direction, of the curved portion (42) of the corner portion (31C1, 33C1) is received by the at least one wire member (31, 33), thereby preventing the securing hook (41) from rotating about the axes of the wire members (31, 32). [3] The seat cushion according to claim 2, wherein the outer end surface (42A1) of the curved portion (42), thus the free end of the curved portion (42), is formed with a projecting part (42A) projecting outward in the radial direction from the curved portion (42).

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