Headrest bushings and vehicle seats

Abstract

To obtain a headrest bush which can easily adjust a height of a rib for suppressing rattling of a stay of a headrest and can be easily assembled to a seat back frame, and a vehicle seat comprising the same.SOLUTION: A headrest bush 30 has a cylindrical part 36 which is inserted into an insertion hole formed at an upper end part of a frame of a seat back and inside which a stay of a headrest is inserted. A pair of front ribs 50A, 50B are so formed on a front face of the cylindrical part 36 as to be arranged in a circumferential direction, and a pair of rear ribs are so formed on a rear face of the cylindrical part 36 as to be arranged in the circumferential direction. On both sides in the circumferential direction with respect to the pair of front ribs 50A, 50B, a pair of slits 48A, 48B, which extend in an axial direction of the cylindrical part 36, are formed. The pair of front ribs 50A, 50B are pressed against an inner peripheral surface of the insertion hole, whereby a part between the pair of slits 48A, 48B bend to a rear side and closes a gap between itself and the stay.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a headrest bush and a vehicle seat. Background Art

[0002] The headrest support structure disclosed in Patent Document 1 below includes a bush that is inserted into a cylindrical holder provided at the upper end of a seat back frame, and a headrest stay that is inserted into an insertion opening provided in the bush. The bush is formed in a cylindrical shape, and two pairs of ribs are provided on the outer peripheral surface of the bush. The two pairs of ribs are arranged side by side in the circumferential direction of the holder. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2018-149885 Summary of Invention Problems to be Solved by the Invention

[0004] In the above prior art, the two pairs of ribs formed on the outer peripheral surface of the bush are brought into contact with the inner peripheral surface of the holder, and a part of the bush is deflected radially inward to suppress rattling of the stay relative to the bush, but there is a problem that adjusting the height of the ribs is difficult. When the height of the ribs is low, it becomes difficult to suppress the above rattling, while when the height of the ribs is high, the load when inserting the bush into the holder increases, making the assembly work complicated.

[0005] In consideration of the above facts, the present invention aims to obtain a headrest bush in which the height of the ribs for suppressing rattling of the headrest stay can be easily adjusted and which can be easily assembled to the seat back frame, and a vehicle seat provided with the same. Means for Solving the Problems

[0006] The headrest bush of the first embodiment is a headrest bush having a cylindrical portion into which a headrest stay is inserted, and into which an insertion hole formed at the upper end of the frame of the seat back is inserted, the headrest bush having a cylindrical portion into which a stay of the headrest is inserted, the headrest bush having a pair of one-side ribs formed circumferentially on one radial side of the outer circumferential surface of the cylindrical portion and which, when pressed against the inner circumferential surface of the insertion hole, cause the one radial side portion of the cylindrical portion to bend radially to the other side, the headrest bush having a pair of other-side ribs formed circumferentially on the other radial side of the outer circumferential surface of the cylindrical portion and which, when pressed against the inner circumferential surface of the insertion hole, cause the other radial side portion of the cylindrical portion to bend radially to the one side, the headrest bush having a pair of slits formed on at least one of the circumferential sides of the pair of one-side ribs and the circumferential sides of the pair of other-side ribs, which extend in the axial direction of the cylindrical portion.

[0007] In the first embodiment of the headrest bush, a cylindrical portion is inserted into an insertion hole formed in the upper end of the seat back frame, and the headrest stay is inserted inside the cylindrical portion. A pair of one-side ribs are formed circumferentially on one radial side of the outer surface of the cylindrical portion, and a pair of other-side ribs are formed circumferentially on the other radial side of the outer surface of the cylindrical portion. The pair of one-side ribs are pressed against the inner surface of the insertion hole, causing the one radial portion of the cylindrical portion to bend radially to the other side. The pair of other-side ribs are pressed against the inner surface of the insertion hole, causing the other radial portion of the cylindrical portion to bend radially to one side. A pair of slits extending axially from the cylindrical portion are formed on at least one of the circumferential sides of the pair of one-side ribs and on the circumferential sides of the pair of other-side ribs. This makes the portion between the pair of slits (i.e., the portion where the pair of one-side ribs or the pair of other-side ribs are formed) more flexible, thus facilitating height adjustment of each rib. Furthermore, the load required when inserting the cylindrical part into the insertion hole is reduced, making the assembly process easier.

[0008] In the second embodiment, the headrest bush is configured such that, in the first embodiment, the spacing between the pair of one-sided ribs is narrower than the spacing between the pair of other-sided ribs, and the pair of slits are formed on both sides of the pair of one-sided ribs in the circumferential direction.

[0009] In the second embodiment of the headrest bush, the spacing between the pair of one-sided ribs is set narrower than the spacing between the pair of other-sided ribs, and a pair of slits are formed on both sides of the pair of one-sided ribs in the circumferential direction, so that the spacing between the pair of slits can be set narrower. As a result, when the pair of one-sided ribs are pressed against the inner circumferential surface of the insertion hole, the load can be concentrated on the portion between the pair of slits in the cylindrical part (i.e., the portion where the pair of one-sided ribs are formed), making that portion more flexible.

[0010] In the third embodiment, the headrest bush is such that, in the second embodiment, the radial side is the front side of the seat, and the pair of slits are formed only on both sides in the circumferential direction relative to the pair of one-sided ribs.

[0011] In the third embodiment of the headrest bush, a pair of one-sided ribs are formed on the front-facing side of the circumferential surface of the cylindrical portion, and a pair of other-sided ribs are formed on the rear-facing side of the circumferential surface of the cylindrical portion. A pair of slits are formed only on both sides of the pair of one-sided ribs in the circumferential direction. As a result, the rear-facing portion of the cylindrical portion is less prone to bending than the front-facing portion. Consequently, for example, when an occupant's head hits the headrest during a rear-end collision, the bending of the rear-facing portion of the cylindrical portion can suppress the displacement of the headrest towards the rear of the seat.

[0012] The headrest bush of the fourth embodiment is configured such that, in any one of the first to third embodiments, the portions of the cylindrical section where the pair of one-sided ribs and the pair of other-sided ribs are formed have higher rigidity than the portions between the pair of one-sided ribs and the portions between the pair of other-sided ribs, the upper end of the seat back frame is made of sheet metal, and the pair of one-sided ribs and the pair of other-sided ribs are pressed against the burring portions formed on the edge of the insertion hole.

[0013] According to the fourth embodiment, the upper end of the seat back frame is made of sheet metal, and the cylindrical portion of the headrest bush is inserted into an insertion hole formed in the upper end. A pair of one-sided ribs and a pair of other-sided ribs are pressed against a burring portion formed at the edge of the insertion hole. In the cylindrical portion, the areas where the pair of one-sided ribs and the pair of other-sided ribs are formed have higher rigidity than the areas between the pair of one-sided ribs and the areas between the pair of other-sided ribs. By varying the rigidity in this way, even in a configuration where the one-sided ribs and other-sided ribs are pressed against a burring portion with poor shape stability, it is possible to precisely adjust the shape and dimensions of the part of the cylindrical portion that is to bend. As a result, the manufacturing of the headrest bush becomes easier.

[0014] A fifth embodiment of a vehicle seat comprises a seat back that supports the back of the occupant, a headrest that supports the head of the occupant, and a headrest bush in any one of the first to fourth embodiments, the cylindrical portion of which is inserted into an insertion hole formed at the upper end of the frame of the seat back, and the stay of the headrest is inserted inside the cylindrical portion.

[0015] In the fifth embodiment of the vehicle seat, the occupant's back is supported by the seat back and the occupant's head is supported by the headrest. The cylindrical portion of the headrest bush is inserted into an insertion hole formed in the upper end of the seat back frame, and the headrest stay is inserted inside the cylindrical portion. Since this headrest bush is of any one of the first to fourth embodiments, the aforementioned effects are obtained. [Effects of the Invention]

[0016] As described above, according to the present invention, it is possible to obtain a headrest bush and a vehicle seat equipped therewith, which allows for easy adjustment of the height of the rib for suppressing rattle of the headrest stay and is easy to assemble to the seat back frame. [Brief explanation of the drawing]

[0017] [Figure 1] It is a perspective view showing a part of the vehicle seat according to the embodiment. [Figure 2] It is a longitudinal sectional view showing the configuration around the headrest bush in the vehicle seat according to the embodiment. [Figure 3] It is a transverse sectional view showing the configuration around the headrest bush in the vehicle seat according to the embodiment. [Figure 4] It is a perspective view showing the headrest bush according to the embodiment. [Figure 5] It is a perspective view showing the headrest bush according to the embodiment. [Figure 6] It is a perspective view showing a headrest bush according to a comparative example. [Figure 7] It is a transverse sectional view showing the configuration around the headrest bush in the vehicle seat according to the comparative example. [Mode for Carrying Out the Invention]

[0018] Hereinafter, the vehicle seat 10 according to one embodiment of the present invention will be described with reference to FIGS. 1 to 5. Note that, in each drawing, some reference numerals may be omitted for the purpose of making the drawings easier to view. In addition, arrows FR, LH, RH and UP appropriately indicated in each drawing respectively indicate the front, left, right and upper sides of the vehicle seat 10. Hereinafter, when the description is given simply using the front-rear, left-right, and up-down directions, the directions refer to directions relative to the vehicle seat 10.

[0019] As shown in FIG. 1, the vehicle seat 10 according to the present embodiment includes a seat back 12 that supports the back of an occupant, a headrest 26 that supports the head of the occupant, and a pair of left and right headrest bushes 30 attached to the upper portion of the frame 14 of the seat back 12. The seat back 12 is erected from the rear end portion of a seat cushion (not shown) on which the occupant sits, and the headrest 26 is connected to the frame 14 of the seat back 12 via the pair of headrest bushes 30. Note that the pair of headrest bushes 30 may be regarded as constituent elements of the seat back 12.

[0020] The seat back 12 includes a seat back pad (not shown) that covers the frame 14, and a seat back skin 20 that covers the surface of the seat back pad. The seat back pad is formed of a foam material such as urethane foam, and the seat back skin 20 is formed into a bag shape by sewing a plurality of skin pieces made of fabric, leather, synthetic leather, or the like.

[0021] The frame 14 includes a pair of left and right side frames 16 extending in the vertical direction, and an upper frame 18 that connects the upper end portions of the pair of side frames 16 in the left-right direction. The pair of side frames 16 are manufactured by press-forming sheet metal, for example, and have a substantially U-shaped cross section with the center side in the left-right direction open when viewed in the vertical direction. The upper frame 18 is manufactured by press-forming sheet metal, for example, and as shown in Figure 2, has a substantially hat-shaped cross section with the rear side open when viewed in the left-right direction.

[0022] The upper frame 18 constitutes the upper end portion of the frame 14, and has an upper plate portion 18A and a lower plate portion 18B that face each other with an interval in the vertical direction. The upper plate portion 18A and the lower plate portion 18B are formed in a long plate shape with the left-right direction as the longitudinal direction and the vertical direction as the plate thickness direction. The front ends of the upper plate portion 18A and the lower plate portion 18B are integrally connected by a front plate portion 18C with the vertical direction as the longitudinal direction and the front-rear direction as the plate thickness direction. An upper flange portion 18D extends integrally upward from the rear end of the upper plate portion 18A, and a lower flange portion 18E extends integrally downward from the rear end of the lower plate portion 18B.

[0023] Upper insertion holes 22 are formed at both the left and right ends of the upper plate portion 18A, through which headrest bushes 30 are inserted. Below the left and right upper insertion holes 22, lower insertion holes 24 are formed at both the left and right ends of the lower plate portion 18B, through which headrest bushes 30 are inserted. The upper insertion holes 22 and lower insertion holes 24 correspond to the "insertion holes" in this invention. A front burring portion 22A, which is bent downwards, is formed at the front edge of each upper insertion hole 22, and a rear burring portion 22B, which is bent downwards, is formed at the rear edge of each upper insertion hole 22. Similarly, a front burring portion 24A, which is bent downwards, is formed at the front edge of each lower insertion hole 24, and a rear burring portion 24B, which is bent downwards, is formed at the rear edge of each lower insertion hole 24.

[0024] As shown in Figure 3, the front burring portion 22A has an arc shape that convex forward when viewed from the vertical direction, and the rear burring portion 22B has an arc shape that convex rearward when viewed from the vertical direction. Although not shown in the illustration, the front burring portion 24A has an arc shape that convex forward when viewed from the vertical direction, and the rear burring portion 24B has an arc shape that convex rearward when viewed from the vertical direction.

[0025] The headrest 26 has a stay 28 that forms its frame, a headrest pad (not shown) which is a cushioning material supported by the stay 28, and a headrest cover 29 that covers the surface of the headrest pad. The stay 28 is made of, for example, a bent metal pipe and has a roughly inverted U shape when viewed from the front or rear. The stay 28 is made of a pair of left and right legs 28A that extend in the vertical direction and a connecting part 28B that connects the upper ends of the pair of legs 28A in the left-right direction. The headrest pad is made of a foam material such as urethane foam. The upper part of the stay 28 is embedded in the headrest pad. The headrest cover 29 is made of a bag-like structure formed by sewing together a plurality of cover pieces made of cloth, leather or synthetic leather.

[0026] A pair of legs 28A of the stay 28 are connected to the frame 14 of the seat back 12 via a pair of headrest bushes 30. Each headrest bush 30 is manufactured, for example, by resin injection molding and is formed in a cylindrical shape overall. As shown in Figures 4 and 5, the headrest bush 30 has a cylindrical hole 32 formed from the upper end to the lower end into which the legs 28A of the stay 28 are inserted. A substantially circular plate-shaped stopper portion 34 is provided at the upper end of the headrest bush 30, and a substantially cylindrical cylindrical portion 36 is provided below the stopper portion 34.

[0027] A pair of legs 28A of the stay 28 are inserted from above into the cylindrical hole 32 of each headrest bush 30. A locking mechanism (not shown) is provided on the stopper portion 34 of each headrest bush 30, restricting the relative vertical movement of each leg 28A with respect to each headrest bush 30. A button 34A for releasing the locking mechanism is provided on the stopper portion 34 of at least one headrest bush 30, and by pressing this button 34A, the stay 28, i.e., the headrest 26, becomes able to move vertically relative to each headrest bush 30.

[0028] The upper part of the cylindrical portion 36 is provided with a substantially circular plate-shaped flange 38 that protrudes radially outward from the cylindrical portion 36. The flange 38 is in contact with the upper edge of the upper insertion hole 22 from above. Above the flange 38, there are a number of ribs 40 that extend vertically along the outer circumferential surface of the cylindrical portion 36 to the lower surface of the stopper portion 34. The number of ribs 40 are arranged at substantially equal intervals in the circumferential direction, for example.

[0029] Furthermore, on the right side in the vehicle width direction of the lower surface of the flange 38, a pair of left and right fitting projections 42 are provided, projecting to the left and right from the outer circumferential surface of the cylindrical portion 36. The pair of fitting projections 42 are fitted into a keyway (not shown) provided in the upper insertion hole 22. As an example, the fitting projections 42 are formed in a substantially rectangular cylindrical shape with the outer side in the left-right direction open, and the lower surface is formed in an arc shape. In addition, a right-angled triangular rib 44 is provided on the arc-shaped lower surface, extending downward along the outer circumferential surface of the cylindrical portion 36.

[0030] As shown in Figure 4, below the flange 38, the front surface of the cylindrical portion 36 (the outer peripheral surface on the front side of the seat; one radial side) is provided with an upper claw portion 46A and a lower claw portion 46B spaced apart in the vertical direction. The upper claw portion 46A and the lower claw portion 46B are formed in a rectangular shape when viewed in the front-rear direction, with their upper ends protruding outward from the outer peripheral surface of the cylindrical portion 36 and having an inclined surface that slopes toward the rear side of the seat as it extends downward. The upper claw portion 46A and the lower claw portion 46B are spaced apart in the axial direction of the cylindrical portion 36. The upper claw portion 46A is positioned so that its upper end catches on the lower edge of the upper insertion hole 22, and the lower claw portion 46B is positioned so that its upper end catches on the lower edge of the lower insertion hole 24. The upper claw portion 46A and the lower claw portion 46B function as retaining claws when the cylindrical portion 36 is inserted into the upper insertion hole 22 and the lower insertion hole 24.

[0031] Furthermore, the cylindrical portion 36 is provided with a pair of slits 48A, each positioned on both sides in the circumferential direction relative to the upper claw portion 46A, and extending vertically from the upper side to the lower side of the upper claw portion 46A. The pair of slits 48A penetrate the cylindrical portion 36 radially and are formed with a width narrower than the circumferential width of the upper claw portion 46A. Additionally, the cylindrical portion 36 is provided with a pair of slits 48B, each positioned on both sides in the circumferential direction relative to the lower claw portion 46B, and extending vertically from the upper side to the lower side of the lower claw portion 46B. The pair of slits 48B penetrate the cylindrical portion 36 radially and are formed with a width narrower than the circumferential width of the lower claw portion 46B.

[0032] The area between the pair of slits 48A and 48B is easily elastically deformed in the radial direction of the cylindrical portion 36. The upper claw portion 46A and the lower claw portion 46B are easily deflected to the rear (radially inward of the cylindrical portion 36) by the slits 48A and 48B on both sides in the circumferential direction, and are configured to deflect to the rear when the headrest bush 30 is inserted into the upper insertion hole 22 and the lower insertion hole 24 by sliding against the edges of the upper insertion hole 22 and the lower insertion hole 24.

[0033] Above the upper claw portion 46A, a pair of front ribs 50A are formed on the front surface (one radial side) of the cylindrical portion 36, projecting radially outward from the cylindrical portion 36. The pair of front ribs 50A are positioned between a pair of slits 48A and are spaced apart in the circumferential direction of the cylindrical portion 36. Similarly, above the lower claw portion 46B, a pair of front ribs 50B are formed on the front surface of the cylindrical portion 36, projecting radially outward from the cylindrical portion 36. The pair of front ribs 50B are positioned between a pair of slits 48B and are spaced apart in the circumferential direction of the cylindrical portion 36. These front ribs 50A and 50B correspond to the "one-sided ribs" in this invention. The areas of the cylindrical portion 36 where the pair of front ribs 50A and 50B are formed are formed to be radially thicker than the intermediate rib portions 52A and 52B, which are located between the pair of front ribs 50A and 50B, thus providing higher rigidity.

[0034] The pair of front ribs 50A are pressed against the inner surface of the front burring portion 22A, which is the inner surface of the upper insertion hole 22, thereby causing the portion between the pair of slits 48A at the front of the cylindrical portion 36 (one side in the radial direction) to bend towards the rear (the other side in the radial direction). The pair of front ribs 50B are pressed against the inner surface of the front burring portion 24A, which is the inner surface of the lower insertion hole 24, thereby causing the portion between the pair of slits 48B at the front of the cylindrical portion 36 (one side in the radial direction) to bend towards the rear (the other side in the radial direction).

[0035] As shown in Figure 5, below the flange 38, a pair of rear ribs 54A are formed on the rear surface (other radial side) of the middle section of the cylindrical portion 36 in the vertical direction, projecting radially outward from the cylindrical portion 36. The pair of rear ribs 54A are spaced apart in the circumferential direction of the cylindrical portion 36 and are positioned at the same height as the pair of front ribs 50A. Similarly, a pair of rear ribs 54B are formed on the lower rear surface of the cylindrical portion 36, projecting radially outward from the cylindrical portion 36. The pair of rear ribs 54B are spaced apart in the circumferential direction of the cylindrical portion 36 and are positioned at the same height as the pair of front ribs 50B. These rear ribs 54A and 54B correspond to the "other side ribs" in the present invention. In the cylindrical portion 36, the area where the pair of rear ribs 54A and 54B are formed is formed to be radially thicker than the intermediate rib portions 56A and 56B located between the pair of rear ribs 54A and 54B, thereby providing higher rigidity.

[0036] The pair of rear ribs 54A are pressed against the inner surface of the rear burring portion 22B, which is the inner surface of the upper insertion hole 22, thereby causing the rear portion (the other radial side) of the cylindrical portion 36 to bend forward (to one radial side). The pair of rear ribs 54B are pressed against the inner surface of the rear burring portion 24B, which is the inner surface of the lower insertion hole 24, thereby causing the rear portion (the other radial side) of the cylindrical portion 36 to bend forward (to one radial side).

[0037] The spacing between the pair of front ribs 50A and 50B is narrower than the spacing between the pair of rear ribs 54A and 54B, and the pair of slits 48A and 48B are formed only on both sides in the circumferential direction relative to the pair of front ribs 50A and 50B.

[0038] In the vehicle seat 10 with the above configuration, the occupant's back is supported by the seat back 12 and the occupant's head is supported by the headrest 26. The cylindrical portion 36 of the headrest bush 30 is inserted into the upper insertion hole 22 and the lower insertion hole 24 formed in the upper part of the frame 14 of the seat back 12, and the leg portion 28A of the stay 28 of the headrest 26 is inserted inside the cylindrical portion 36.

[0039] A pair of front ribs 50A and 50B are formed on the front surface of the cylindrical portion 36, arranged circumferentially, and a pair of rear ribs 54A and 54B are formed on the rear surface of the cylindrical portion 36, arranged circumferentially. The pair of front ribs 50A and 50B are pressed against the inner circumferential surfaces of the upper insertion hole 22 and the lower insertion hole 24, causing the front part of the cylindrical portion 36 to bend towards the rear. The pair of rear ribs 54A and 54B are pressed against the inner circumferential surfaces of the upper insertion hole 22 and the lower insertion hole 24, causing the rear part of the cylindrical portion 36 to bend towards the front. As a result, rattling of the headrest bush 30 relative to the frame 14 is prevented or effectively suppressed.

[0040] A pair of slits 48A and 48B are formed on both sides of the circumferential direction of the pair of front ribs 50A and 50B, extending in the axial direction of the cylindrical portion 36. This makes the portion between the pair of slits 48A and 48B (i.e., the portion where the pair of front ribs 50A and 50B are formed) more flexible, so that a change in the protruding height of the pair of front ribs 50A and 50B easily affects the change in the amount of deflection of the portion between the pair of slits 48A and 48B. As a result, the height adjustment of each of the ribs 50A, 50B, 54A, and 54B becomes easier. Moreover, the load when inserting the cylindrical portion 36 into the upper insertion hole 22 and the lower insertion hole 24 is reduced, making assembly work easier.

[0041] Furthermore, in this headrest bush 30, the spacing between the pair of front ribs 50A and 50B is set to be narrower than the spacing between the pair of rear ribs 54A and 54B, and a pair of slits 48A and 48B are formed on both sides of the pair of front ribs 50A and 50B in the circumferential direction. This allows the spacing between the pair of slits 48A and 48B to be set to be narrow. As a result, when the pair of front ribs 50A and 50B are pressed against the inner circumferential surfaces of the upper insertion hole 22 and the lower insertion hole 24, the load can be concentrated on the portion of the cylindrical portion 36 between the pair of slits 48A and 48B (i.e., the portion where the pair of front ribs 50A and 50B are formed), making that portion more flexible.

[0042] Furthermore, in this headrest bush 30, a pair of slits 48A and 48B are formed only on both sides in the circumferential direction of the pair of front ribs 50A and 50B. This makes the rear part of the cylindrical portion 36 less prone to bending than the front part. As a result, for example, when an occupant's head hits the headrest 26 during a rear-end collision of a vehicle, the bending of the rear part of the cylindrical portion 36 can suppress the displacement of the headrest 26 toward the rear.

[0043] Furthermore, in this embodiment, the upper frame 18 that constitutes the upper end of the frame 14 of the seat back 12 is made of sheet metal, and the cylindrical portion 36 of the headrest bush is inserted into the upper insertion hole 22 and the lower insertion hole 24 formed in the upper frame 18. Then, a pair of front ribs 50A, 50B and a pair of rear ribs 54A, 54B are pressed against the burring portions 22A, 22B, 24A, 24B formed on the edges of the upper insertion hole 22 and the lower insertion hole 24.

[0044] In the cylindrical portion 36, the areas where the pair of front ribs 50A, 50B and the pair of rear ribs 54A, 54B are formed have higher rigidity than the intermediate rib portions 52A, 52B between the pair of front ribs 50A, 50B and the intermediate rib portions 56A, 56B between the pair of rear ribs 54A, 54B. By varying the rigidity in this way, even in a configuration where the front ribs 50A, 50B and rear ribs 54A, 54B are pressed against the burring portions 22A, 22B, 24A, 24B, which have poor shape stability, it becomes possible to precisely adjust the shape and dimensions of the parts of the cylindrical portion 36 that are to bend. As a result, the manufacturing of the headrest bush 30 becomes easier.

[0045] The effects described above will be further explained with reference to the comparative examples shown in Figures 6 and 7. The headrest bush 100 in this comparative example does not have a pair of slits 48A and 48B, and the spacing between the pair of front ribs 50A and 50B and the spacing between the pair of rear ribs 54A and 54B are set to be the same.

[0046] In this headrest bush 100, a pair of front ribs 50A, 50B and a pair of rear ribs 54A, 54B are pressed against the inner circumferential surfaces of the upper insertion hole 22 and the lower insertion hole 24, causing the cylindrical portion 36 to bend radially inward over almost its entire circumference (see arrow P in Figure 7). This reduces the gap between the leg portion 28A of the stay 28 and the bush, suppressing rattle of the stay 28. However, because the bending portion is continuous and has high rigidity, even if the height of each of the ribs 50A, 50B, 54A, 54B is changed, the change in the amount of bending of the cylindrical portion 36 is small, making it difficult to adjust the gap reduction. In contrast, in this embodiment, the portion between the pair of slits 48A, 48B is formed to be narrow, reducing its rigidity. As a result, changing the height of the pair of front ribs 50A, 50B has a greater impact on the change in the amount of bending of the above portion, making adjustment easier.

[0047] Furthermore, in the headrest bush 100 described above, the cylindrical portion 36 is difficult to flex because it is deflected radially inward along almost its entire circumference. As a result, the amount of interference between each rib 50A, 50B, 54A, and 54B and the upper frame 18 increases, and the insertion force of the cylindrical portion 36 into the upper insertion hole 22 and the lower insertion hole 24 increases. In contrast, in this embodiment, the front ribs 50A and 50B are positioned in the area between a pair of elastically deformable slits 48A and 48B, so it is only necessary to flex the area between the pair of slits 48A and 48B. Therefore, the insertion force of the cylindrical portion 36 into the upper insertion hole 22 and the lower insertion hole 24 can be reduced.

[0048] Although the present invention has been described above with reference to embodiments, the present invention can be implemented with various modifications without departing from its spirit. Furthermore, it goes without saying that the scope of the present invention is not limited to the above embodiments. [Explanation of symbols]

[0049] 10 Vehicle seats 12 Seatback 14 frames 22 Upper insertion hole (insertion hole) 22A Front burring section (burring section) 22B Rear burring section (burring section) 24 Lower insertion hole (insertion hole) 24A Front burring section (burring section) 24B Rear burring section (burring section) 26 Headrests 28 Stay 30 Headrest Bushings 36. Cylindrical part 48A Slit 48B Slit 50A Front rib (one-sided rib) 50B Front rib (one-sided rib) 54A Rear rib (other rib) 54B Rear rib (other rib)

Claims

1. A headrest bush having a cylindrical portion that is inserted into an insertion hole formed in the upper end of the seat back frame, into which the headrest stay is inserted, A pair of one-sided ribs are formed circumferentially on one radial side of the outer surface of the cylindrical portion, and when pressed against the inner surface of the insertion hole, they cause the radially one side of the cylindrical portion to bend radially to the other side; A pair of other-side ribs are formed circumferentially on the other radial side of the outer surface of the cylindrical portion, and when pressed against the inner surface of the insertion hole, they cause the other radial side of the cylindrical portion to bend radially toward one side; A pair of slits extending in the axial direction of the cylindrical portion are formed on at least one of the circumferential sides of the pair of one-sided ribs and on at least one of the circumferential sides of the pair of other-sided ribs, It has, The spacing between the pair of ribs on one side is set to be narrower than the spacing between the pair of ribs on the other side. The pair of slits are formed on both sides in the circumferential direction of the pair of one-sided ribs, The aforementioned radial side is the front side of the seat, The pair of slits are formed only on both sides in the circumferential direction of the pair of one-sided ribs of the headrest bush.

2. A headrest bush having a cylindrical portion that is inserted into an insertion hole formed in the upper end of the seat back frame and into which a headrest stay is inserted, A pair of one-sided ribs are formed circumferentially on one radial side of the outer surface of the cylindrical portion, and when pressed against the inner surface of the insertion hole, they cause the radially one side of the cylindrical portion to bend radially to the other side; A pair of other-side ribs are formed circumferentially on the other radial side of the outer surface of the cylindrical portion, and when pressed against the inner surface of the insertion hole, they cause the other radial side of the cylindrical portion to bend radially toward one side; A pair of slits extending in the axial direction of the cylindrical portion are formed on at least one of the circumferential sides of the pair of one-sided ribs and on at least one of the circumferential sides of the pair of other-sided ribs, It has, In the cylindrical portion, the areas where the pair of one-sided ribs and the pair of other-sided ribs are formed are set to have higher rigidity than the areas between the pair of one-sided ribs and the areas between the pair of other-sided ribs. The upper end of the frame of the seat back is made of sheet metal, and the pair of one-sided ribs and the pair of other-sided ribs are pressed against the burring portion formed on the edge of the insertion hole of the headrest bush.

3. The spacing between the pair of ribs on one side is set to be narrower than the spacing between the pair of ribs on the other side. The headrest bush according to claim 2, wherein the pair of slits are formed on both sides in the circumferential direction relative to the pair of one-sided ribs.

4. A seat back that supports the back of the occupant, A headrest that supports the head of the aforementioned occupant, A headrest bush according to any one of claims 1 to 3, wherein the cylindrical portion is inserted into an insertion hole formed at the upper end of the frame of the seat back, and the stay of the headrest is inserted inside the cylindrical portion, A vehicle seat equipped with [a specific feature / feature].

Images