Vehicle seat

Abstract

To provide a vehicle seat that is able to prevent a wire for supporting a lumbar support from being pulled and separated from a back frame.SOLUTION: A vehicle seat 10 includes: a seat back 14 supporting the back part of a seated occupant from a seat rear side; a back frame 18 composing a skeleton of the seat back and having an insertion hole 32A; and a lumbar support 34 disposed in the seat back 14 and at a position facing the waist part of the seated occupant in a seat longitudinal direction. The vehicle seat 10 includes a support wire 36 extending from the lumbar support 34 toward the insertion hole 32A and locked to the insertion hole 32A while kept inserted into the insertion hole 32A. A notch 36C, which is directly or indirectly locked to an edge of the insertion hole 32A when the lumbar support 34 is pressed toward a seat rear side, is formed in the support wire 36.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Patent Document 1 below discloses a vehicle seat equipped with a lumbar support (posture-maintaining member) that supports the lower back of a seated occupant. The lumbar support described in this document has a wire that extends toward the back frame. The wire is inserted into a hole (a pivotal support portion) formed in the back frame, so that the lumbar support is supported by the back frame via the wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-136649 Summary of the Invention [Problem to be solved by the invention]

[0004] In the event of a rear-end collision, the lumbar support is pressed toward the rear of the seat with a strong force. Therefore, it is important to prevent the wire supporting the lumbar support from coming off the back frame. However, the configuration described in Patent Document 1 has room for improvement in this regard.

[0005] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a vehicle seat that can prevent a wire supporting a lumbar support from coming off from a back frame. [Means for solving the problem]

[0006] The vehicle seat of the first embodiment comprises a seat back that supports the back of a seated occupant from the rear side of the seat, a back frame that forms the skeleton of the seat back and has an insertion portion, a lumbar support that is positioned within the seat back in a position opposite the seat occupant's lower back in the fore-and-aft direction of the seat, and a wire that extends from the lumbar support toward the insertion portion, is engaged with the insertion portion when inserted into the insertion portion, and has a notch formed in it that engages directly or indirectly with the edge of the insertion portion when the lumbar support is pressed toward the rear side of the seat.

[0007] In the vehicle seat of the first aspect, the back of the seated occupant is supported from the rear side of the seat by the seat back, and the lumbar region of the seated occupant is supported from the rear side of the seat by the lumbar support. Here, a wire extends from the lumbar support and is inserted into an insertion portion of the back frame and engaged with the insertion portion. As a result, the lumbar support is supported on the back frame via the wire. Here, when the lumbar support is pressed toward the rear side of the seat during a rear-end collision of the vehicle, a notch formed in the wire engages directly or indirectly with the edge of the insertion portion. This makes it possible to prevent the wire supporting the lumbar support from coming loose from the back frame.

[0008] The second embodiment of the vehicle seat is the vehicle seat of the first embodiment, in which a bushing is attached to the edge of the insertion portion, and when the force pressing the lumbar support toward the rear of the seat exceeds a specified load, the bushing breaks and the notch directly engages with the edge of the insertion portion.

[0009] In the vehicle seat of the second aspect, a bushing is attached to the edge of the insertion portion. When the force pressing the lumbar support toward the rear of the seat exceeds a predetermined load, the bushing breaks and the notch directly engages with the edge of the insertion portion. By directly engaging the notch with the edge of the insertion portion in this way, the wire supporting the lumbar support can be more securely prevented from slipping out of the back frame.

[0010] A third aspect of the vehicle seat is a vehicle seat of the first aspect, in which a bush is attached to the edge of the insertion portion, the bush having a portion formed in a shape that gradually narrows as the wire moves in the direction of insertion into the insertion portion.

[0011] In the vehicle seat of the third aspect, a bushing is attached to the edge of the insertion portion. This bushing has a portion formed in a shape that gradually narrows as the wire approaches the insertion direction of the insertion portion. Therefore, when inserting the wire into the insertion portion, the tip of the wire can be guided along the portion of the bushing toward the insertion portion. This improves the workability when inserting the wire into the insertion portion. [Effects of the Invention]

[0012] The vehicle seat according to the present invention has the excellent effect of preventing the wire supporting the lumbar support from coming off the back frame. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a side view schematically showing a vehicle seat according to an embodiment of the present invention; [Figure 2] FIG. 2 is a front view showing a lumbar unit supported by a back frame. [Figure 3] FIG. 10 is an enlarged perspective view showing the vicinity of an upper locking portion of the support wire. [Figure 4]10 is a cross-sectional view showing a cross section of the support wire, the intermediate frame portion, and the bush taken along the front-rear and up-down directions at a portion corresponding to the upper locking portion of the support wire. FIG. [Figure 5] FIG. 5 is a cross-sectional view corresponding to FIG. 4, showing a state in which a vehicle has been hit from behind. DETAILED DESCRIPTION OF THE INVENTION

[0014] A vehicle seat 10 according to an embodiment of the present invention will be described with reference to Figures 1 to 5. In the drawings, the arrow FR indicates the front side of the seat, the arrow UP indicates the upper side of the seat, the arrow LH indicates the left side in the seat width direction, and the arrow RH indicates the right side in the seat width direction. Furthermore, in the following description, when directions such as front-rear, up-down, and left-right are indicated, they refer to front-rear in the seat front-rear direction, up-down in the seat up-down direction, and left-right in the seat width direction unless otherwise specified.

[0015] As shown in FIG. 1, the vehicle seat 10 of this embodiment includes a seat cushion 12 that supports the buttocks of a seated occupant from below, a seat back 14 that supports the back of the seated occupant from the rear, and a lumbar support unit 16 provided within the seat back 14.

[0016] As shown in FIGS. 1 and 2, the seat back 14 is configured to include a back frame 18 that forms the framework of the seat back 14 and a back pad 20 attached to the back frame 18.

[0017] The back frame 18 includes a pair of left and right side frame portions 22 that are spaced apart in the seat width direction and extend in the up-down direction. The back frame 18 also includes an upper frame portion 24 that connects the upper ends of the pair of left and right side frame portions 22 in the seat width direction, and a lower frame portion 26 that connects the lower ends of the pair of left and right side frame portions 22 in the seat width direction. The back frame 18 also includes an intermediate frame portion 28 that is located below the upper frame portion 24 and connects the upper portions of the pair of left and right side frame portions 22 in the seat width direction.

[0018] The intermediate frame portion 28 is formed, for example, by pressing a steel plate material. The intermediate frame portion 28 includes a base plate portion 30 extending in the left-right direction. Both left-right end portions 30A of the base plate portion 30 are offset forward relative to a left-right middle portion 30B of the base plate portion 30. The left-right end portions 30A of the base plate portion 30 are joined to a pair of left and right side frame portions 22 by welding or the like. The intermediate frame portion 28 also includes a lower flange portion 32 extending forward from the lower end of the left-right middle portion 30B.

[0019] As shown in Figure 2, the lumbar support unit 16 is composed of a lumbar support 34 arranged in the seat back 14 at a position facing the lower back of the seated occupant in the fore-and-aft direction, and a support wire 36 as a wire for supporting the lumbar support 34 on the back frame 18.

[0020] The lumbar support 34 includes a lumbar plate 38 formed using, for example, a resin material. The lumbar plate 38 is rectangular in shape when viewed from the front of the seat and is formed like a plate with a thickness extending in the front-to-rear direction, with appropriate lightening holes at both left and right ends and a central portion. The lumbar support 34 also includes a first fixing member 40, a second fixing member 42, and a third fixing member 44 that extend in the left-to-right direction behind the lumbar plate 38 and are spaced apart in the up-down direction. The first fixing member 40 is fixed to the upper end of the lumbar plate 38. The second fixing member 42 is fixed to the center of the lumbar plate 38 in the up-down direction. The third fixing member 44 is fixed to the lower end of the lumbar plate 38. The lumbar support 34 also includes an actuator 46 provided behind the lumbar plate 38. The actuator 46 is supported in a state spanning between the second fixing member 42 and the third fixing member 44. When the actuator portion 46 is actuated, the vertical distance between the second fixing member 42 and the third fixing member 44 changes, and the shape of the lumbar plate 38 changes.

[0021] The support wire 36 is formed, for example, by bending a steel rod and is bent into a generally U-shaped, left-right symmetrical shape with an open upper side when viewed from the front of the seat. Each portion of the support wire 36 is engaged with a first fixing member 40, a second fixing member 42, and a third fixing member 44. A longitudinal center portion 36A of the support wire 36 is disposed below the lumbar plate 38 when viewed from the front of the seat. The longitudinal center portion 36A of the support wire 36 is fixed to the lower frame portion 26 via a bracket 48. One end portion 36B of the support wire 36 extends upward relative to the left end portion of the first fixing member 40. The other end portion 36B of the support wire 36 extends upward relative to the right end portion of the first fixing member 40.

[0022] 2 and 3, one end 36B and the other end 36B of the support wire 36 are respectively engaged with both ends in the seat width direction of the lower flange portion 32 of the intermediate frame portion 28. Note that the configuration of the engaging portion between the one end 36B of the support wire 36 and the left end of the lower flange portion 32 is similar to the configuration of the engaging portion between the other end 36B of the support wire 36 and the right end of the lower flange portion 32. Therefore, in the following explanation, the configuration of the engaging portion between the one end 36B of the support wire 36 and the left end of the lower flange portion 32 will be described, and an explanation of the configuration of the engaging portion between the other end 36B of the support wire 36 and the right end of the lower flange portion 32 will be omitted.

[0023] 3 and 4, the lower flange portion 32 slopes downward as it extends rearward. An insertion hole 32A is formed at the left end of the lower flange portion 32 so as to penetrate the lower flange portion 32 as an insertion portion into which one end 36B of the support wire 36 is inserted from below. The edge of the insertion hole 32A has a circular shape when viewed from the thickness direction of the lower flange portion 32. In the following description, the insertion direction of one end 36B of the support wire 36 into the insertion hole 32A may be simply referred to as insertion direction A (direction of arrow A).

[0024] A bushing 50 is attached around the insertion hole 32A in the lower flange portion 32. The bushing 50 is formed into a cylindrical shape using, for example, a resin material. The bushing 50 includes a first cylindrical portion 52 and a second cylindrical portion 54 that is also formed into a cylindrical shape and is connected to the first cylindrical portion 52 below the first cylindrical portion 52. The first cylindrical portion 52 and the second cylindrical portion 54 are arranged coaxially. The outer diameter of the first cylindrical portion 52 is set to be smaller than the outer diameter of the second cylindrical portion 54. The inner surface of the first cylindrical portion 52 has a first tapered surface 52A that gradually narrows toward the second cylindrical portion 54. The inner surface of the second cylindrical portion 54 has a second tapered surface 54A that gradually narrows toward the first cylindrical portion 52. The connection between the first tapered surface 52A and the second tapered surface 54A on the inner periphery of the bushing 50 forms a corner 56 that is pointed radially inward of the bushing 50. The bushing 50 described above is attached to the lower flange 32 by inserting the first cylindrical portion 52 from below into an insertion hole 32A formed in the lower flange 32. Here, attachment of the bushing 50 to the lower flange 32 is completed when the second cylindrical portion 54 abuts against the lower surface of the lower flange 32. When attachment of the bushing 50 to the lower flange 32 is completed, the corner 56 of the bushing 50 is positioned radially inward of the edge of the insertion hole 32A.

[0025] As shown in FIG. 4 , a notch 36C recessed toward the center of the support wire 36 is formed at the rear of one end 36B of the support wire 36. The recess of this notch 36C relative to the outer circumferential surface of the support wire 36 gradually deepens toward the insertion direction A. The one end 36B of the support wire 36 described above is inserted from below into the insertion hole 32A formed at the left end of the lower flange 32 and into the bushing 50 attached to the lower flange 32. This completes the engagement of the one end 36B of the support wire 36 with the lower flange 32. When the one end 36B of the support wire 36 is completely engaged with the lower flange 32, the lower end of the notch 36C formed at the rear of the one end 36B of the support wire 36 is positioned adjacent to the corner portion 56 of the bushing 50 in the front-to-rear direction.

[0026] (Actions and Effects of This Embodiment) Next, the operation and effects of this embodiment will be described.

[0027] 1 and 2, in the vehicle seat 10 of this embodiment, the buttocks of the seated occupant are supported from below by the seat cushion 12, and the back of the seated occupant is supported from behind by the seat back 14. The lumbar region of the seated occupant is supported from behind by the lumbar support 34 via the back pad 20. When the actuator portion 46 of the lumbar support 34 is actuated, the vertical distance between the second fixing member 42 and the third fixing member 44 changes, and the shape of the lumbar plate 38 changes. This allows the state of support of the lumbar region by the lumbar plate 38 to be adjusted according to the physique and preferences of the seated occupant.

[0028] Here, the lumbar support 34 is supported by the back frame 18 via a support wire 36. As shown in Figures 3 and 4, one end 36B of the support wire 36 is inserted from below into an insertion hole 32A formed in the left end of the lower flange portion 32 and into a bushing 50 attached to the left end of the lower flange portion 32. Although not shown, the other end 36B of the support wire 36 is inserted from below into an insertion hole 32A formed in the right end of the lower flange portion 32 and into a bushing 50 attached to the right end of the lower flange portion 32.

[0029] When the lumbar support 34 is pressed rearward during a rear-end collision of the vehicle, the notch 36C formed in the support wire 36 is engaged with the corner portion 56 of the bushing 50, as shown in FIG. 5 . That is, the notch 36C formed in the support wire 36 is indirectly engaged with the edge of the insertion hole 32A via the bushing 50. This prevents the support wire 36 supporting the lumbar support 34 from slipping out of the back frame 18 (insertion hole 32A). This configuration also eliminates the need to insert the support wire 36 far enough into the insertion hole 32A to prevent the support wire 36 from slipping out of the insertion hole 32A. As a result, the amount of upward protrusion of the support wire 36 relative to the lower flange portion 32 can be reduced. This reduces the volume (capacity) of the space within the seat back 14 occupied by the support wire 36.

[0030] Furthermore, in this embodiment, when the force pressing the lumbar support 34 rearward exceeds a predetermined threshold during a rear-end collision of the vehicle, the bushing 50 cracks (destroys), and the notch 36C formed in the support wire 36 directly engages with the edge of the insertion hole 32A. By having the notch 36C directly engage with the edge of the insertion hole 32A in this way, the support wire 36 supporting the lumbar support 34 can be more securely prevented from coming off the back frame 18 (insertion hole 32A).

[0031] 3 and 4, in this embodiment, the inner surface of the second cylindrical portion 54 of the bushing 50 has a second tapered surface 54A that gradually narrows toward the first cylindrical portion 52 (insertion direction A). With this configuration, when inserting the support wire 36 into the insertion hole 32A, the tip 36D of the support wire 36 can be guided along the second tapered surface 54A toward the insertion hole 32A. This improves the ease of inserting the support wire 36 into the insertion hole 32A.

[0032] In the present embodiment, an example has been described in which the second tapered surface 54A that functions as described above is provided on the bushing 50, but the present invention is not limited to this. Whether or not to provide the second tapered surface 54A that functions as described above on the bushing 50 can be determined appropriately taking into consideration the assembly process of the vehicle seat 10, etc.

[0033] Furthermore, in the present embodiment, an example has been described in which, when the force pressing the lumbar support 34 rearward exceeds a predetermined threshold, the bushing 50 cracks (breaks) and the notch 36C formed in the support wire 36 directly engages with the edge of the insertion hole 32A, but the present invention is not limited to this. For example, the strength of the bushing 50 can be increased to prevent the bushing 50 from cracking in the event of a rear-end collision of the vehicle. Also, the bushing 50 can be omitted, and the notch 36C formed in the support wire 36 can be directly engaged with the edge of the insertion hole 32A.

[0034] The above describes one embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that it can be implemented in various other modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0035] 10 Vehicle seats 14 Seat back 18 Back Frame 32A Insertion hole (insertion part) 34 Lumbar support 36 Support wire (wire) 36C notch 50 Bush

Claims

1. a seat back that supports the back of a seated occupant from the rear side of the seat; A back frame that forms a framework of the seat back and has an insertion portion; a lumbar support disposed in the seat back at a position facing the lumbar region of a seated occupant in the front-rear direction of the seat; a wire extending from the lumbar support toward the insertion portion, and being engaged with the insertion portion when inserted into the insertion portion, the wire having a notch formed thereon, the notch being engaged directly or indirectly with an edge of the insertion portion when the lumbar support is pressed toward the rear side of the seat; A vehicle seat comprising:

2. A bushing is attached to the edge of the insertion portion, 2. The vehicle seat according to claim 1, wherein the bushing breaks when the force pressing the lumbar support toward the rear of the seat exceeds a predetermined load, and the notch directly engages with the edge of the insertion portion.

3. 2. The vehicle seat according to claim 1, wherein a bushing is attached to an edge of the insertion portion, the bushing having a portion formed in a shape that gradually narrows as the wire advances in the direction in which the wire is inserted into the insertion portion.

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