Reclining device and seat

Abstract

Provided is a reclining device that achieves effective abnormal noise prevention while allowing a gap between a cam and a connecting rod. A reclining device (5) comprises a pair of reclining mechanisms (6) each having an internal gear (30) and a cam (50), a connecting rod (7) that is coaxially connected to the respective cams (50) and rotates together with the cams (50), and resin bushings (8) having a fitting holes (8e) that can fit on fitting portions (7c) in the vicinity of end parts (7b) of the connecting rod (7). The resin bushings (8) are inserted in a bushing insertion hole (35) of the internal gear (30) in a state of contact with the inner-peripheral surface of the bushing insertion hole (35) so as to position the connecting rod (7) in relation to the cam (50) in a state in which a gap (9) is formed between an inner-peripheral surface (52a1) of a rod insertion hole (52a) of the cam (50) and an outer-peripheral surface (7f) of the connecting rod (7).

Description

Technical Field

[0001] The present invention relates to a reclining device and a seat provided with the reclining device.

Background Art

[0002] Conventional seats such as those in vehicles have a structure in which a seat back (rear seat back) can tilt in the front-rear direction with respect to a seat cushion (seat portion), and there is a seat provided with a reclining device that fixes the seat back at an arbitrary tilt angle.

[0003] The reclining device includes a pair of reclining mechanisms (recliners) disposed at positions on both sides in the width direction of the seat, and a connecting rod disposed so as to extend in the width direction of the seat and connecting the pair of reclining mechanisms.

[0004] Each of the pair of reclining mechanisms includes a cam coaxially coupled to both end portions of the connecting rod and capable of rotating together with the connecting rod. When the connecting rod receives a rotational operating force from outside the seat, the cam rotates in a predetermined direction together with the connecting rod, and it is possible to separate a lock plate disposed around the cam from an internal gear to release the lock.

[0005] In the structure in which the end portion of the connecting rod as described above is coaxially coupled to the cam, due to the following structural reasons, it is necessary to provide a gap between the inner peripheral surface of the through hole of the cam and the outer peripheral surface of the connecting rod. That is, due to dimensional variations and twisting of the frame assembly (that is, an aggregate of frames such as those of the seat back and seat cushion and reclining mechanisms assembled to the frame, and misalignment and distortion during frame assembly), there is a possibility of an unfavorable influence on the operability of the reclining mechanism and the locking load. In order to absorb such an influence, it is necessary to provide the above-described gap.

[0006] Because a gap needs to be provided between the cam and the connecting rod as described above, conventional reclining devices have the problem of the cam and connecting rod interfering with each other due to the shaking of the vehicle body or external impacts, resulting in abnormal noise (knocking noise).

[0007] Therefore, in order to prevent the generation of abnormal noise while allowing a gap between the cam and the connecting rod, the reclining device described in Patent Document 1 attempts to suppress abnormal noise by interposing a thin elastic ring between the cam and the connecting rod.

[0008] However, in a structure where a thin elastic ring is interposed between the cam and the connecting rod, as described in Patent Document 1, the relative positioning of the cam and the connecting rod is performed by the thin elastic ring, making it difficult to achieve effective noise prevention while allowing a gap between the cam and the connecting rod. The reason for this is as follows.

[0009] First, the dimensions of the elastic ring are limited by the width of the gap between the cam and the connecting rod, making it structurally difficult to increase the rigidity by making the elastic ring thicker. Given these dimensional constraints on the elastic ring, increasing its rigidity to prevent the aforementioned noise would make it difficult to insert the elastic ring into the gap between the cam and the connecting rod, affecting the assembly of the reclining device. On the other hand, decreasing the rigidity of the elastic ring would reduce the holding force of the connecting rod, causing it to contact the cam and generate noise even with slight movement of the connecting rod, making it difficult to achieve effective noise prevention while allowing the aforementioned gap. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 3972648 [Overview of the project]

[0011] The present invention has been made in view of the above circumstances, and aims to provide a reclining device that can achieve effective noise prevention while allowing a gap between the cam and the connecting rod. [Means for solving the problem]

[0012] The reclining device of the present invention comprises a pair of reclining mechanisms each having an internal gear fixed to the frame of one of the seat cushion or seat back, and a cam arranged in line with the thickness direction of the internal gear, and a connect rod extending along the width direction of the seat and coaxially coupled to the cam of each of the pair of reclining mechanisms, and rotating together with the cam, and holds the seat back tiltably relative to the seat cushion and fixes it at an arbitrary tilt angle, and is a cylindrical body having a fitting hole, and a fitting portion formed near the end of the connect rod The cam has a rod insertion hole into which the end of the connect rod can be inserted, and the internal gear has a bush insertion hole at the center of the internal gear into which the resin bush can be inserted, the fitting portion near the end of the connect rod fits into the fitting hole of the resin bush, the end of the connect rod protrudes to the outside of the resin bush, and the resin bush is inserted into the bush insertion hole of the internal gear in contact with the inner surface of the bush insertion hole so as to position the connect rod relative to the cam with a gap formed between the inner surface of the rod insertion hole of the cam and the outer surface of the connect rod. The fitting portion of the connect rod has a tapered shape that becomes narrower towards the end of the connect rod, and the fitting hole of the resin bush has a tapered hole portion that can be fitted into the tapered portion of the connect rod. The above-mentioned features include the inner circumferential surface of the bush insertion hole, as well as the edge of the bush insertion hole. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view showing the overall configuration of a seat equipped with a reclining device according to an embodiment of the present invention. [Figure 2]Figure 1 is an enlarged perspective view showing the arrangement of the resin bushing and reclining mechanism near the end of the connect rod. [Figure 3] Figure 2 is a perspective view showing the connect rod, resin bushing, and reclining mechanism separated. [Figure 4] Figure 3 is a perspective view of the resin bushing. [Figure 5] Figure 3 shows the connect rod, where (a) is an enlarged perspective view showing the structure around the end of the connect rod, (b) is a view of the end of (a) from the tip side, and (c) is a view of the structure around the end of (a) from the outer side. [Figure 6] Figure 1 shows the main structure of the reclining device, and Figure 2 is a cross-sectional diagram illustrating the structure in which the connecting rod, resin bushing, and reclining mechanism are connected. [Figure 7] Figure 6 is an enlarged cross-sectional view showing the resin bush and its surrounding area. [Figure 8] Figure 6 shows cross-sectional views of the connect rod and its surrounding area, where (a) is a cross-sectional view along line AA, (b) is a cross-sectional view along line BB, (c) is a cross-sectional view along line CC, (d) is a cross-sectional view along line DD, and (E) is a cross-sectional view along line EE. [Figure 9] Figure 3 is an exploded perspective view of the reclining mechanism. [Figure 10] This is a perspective view of a resin bush with an improved main body according to a modified example of the present invention. [Figure 11] Figure 10 shows a resin bushing, where (a) is a side view seen from the tip side of the claw portion, (b) is a front view, (c) is a side view seen from the tip side of the main body portion, (d) is a cross-sectional view of (c) along the FF line, and (e) is a plan view. [Figure 12] This is a cross-sectional diagram illustrating the structure in which the resin bushing shown in Figure 10 is connected to the connecting rod and reclining mechanism shown in Figure 6. [Figure 13] This is a perspective view of a small resin bush having an engaging portion that engages with a frame, according to another modification of the present invention. [Figure 14]FIG. 13 is a view showing a resin bush, where (a) is a side view seen from the tip side of the claw portion, (b) is a front view, (c) is a side view seen from the side facing the plane of the flange portion, (d) is a sectional view taken along line G-G of (c), and (e) is a plan view. [Figure 15] FIG. 13 is a cross-sectional explanatory view of a structure in which the resin bush, the connecting rod of FIG. 6, and the reclining mechanism are combined.

Embodiment for Carrying out the Invention

[0014] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0015] As shown in FIG. 1, the seat 1 of the present embodiment is a seat for a vehicle or the like, and includes a seat cushion 2 that supports the buttocks of the seated person, and a seat back 3 that is disposed at the rear of the seat cushion 2 to support the back of the seated person and is tiltable in the front-rear direction X of the seat 1 with respect to the seat cushion 2, a slide device 4 attached to the lower part of the seat cushion 2, and a reclining device 5.

[0016] The slide device 4 has a configuration that guides the seat cushion 2 slidably in the front-rear direction X of the seat 1 and can fix the seat cushion 2 at an arbitrary position. Note that in the seat of the present invention, the slide device 4 is not essential and may be omitted.

[0017] The reclining device 5 has a configuration that can fix the seat back 3 at an arbitrary inclination angle.

[0018] Specifically, as shown in FIGS. 2 to 3, the reclining device 5 of the present embodiment includes a pair of reclining mechanisms 6, a connecting rod 7 connected to the pair of reclining mechanisms 6, and a pair of resin bushes 8 fitted to fitting portions 7c in the vicinity of both end portions 7b of the connecting rod 7.

[0019] A pair of reclining mechanisms 6 are positioned on both sides of the seat 1 in the width direction Y. Each reclining mechanism 6 acts as a clutch to fix the seat back 3 at any desired tilt angle, and its detailed configuration will be explained separately later.

[0020] As shown in Figures 3, 6, and 9, the reclining mechanism 6 of this embodiment includes an internal gear 30 fixed to one of the frames of the seat cushion 2 or the seat back 3, in this embodiment to the frame 3a of the seat back 3 (specifically, the side frame that constitutes the side of the seat back 3) by fitting or welding, and a cam 50 arranged in line with the internal gear 30 in its thickness direction (i.e., the axial direction S of the connect rod 7 in Figure 3).

[0021] In other words, in the reclining device of the present invention, the reclining mechanism 6 only needs to include at least an internal gear 30 and a cam 50, and other components may be modified as appropriate.

[0022] The cam 50 has a rod insertion hole 52a into which the end 7b of the connect rod 7 can be inserted, as shown in Figures 6-7, 8(a), and 9. The rod insertion hole 52a has a substantially elliptical cross-sectional shape (specifically, a circular shape that is flattened inward from both sides) (see in particular Figures 8(a) and 9).

[0023] As shown in Figures 6-7 and 9, the internal gear 30 has a bush insertion hole 35 at its center, through which a resin bush 8 can be inserted via a through hole 3b (see Figures 3, 6-7) formed in the frame 3a. The bush insertion hole 35 has a circular cross-section.

[0024] The connect rod 7 is a rod-shaped member positioned to extend along the width direction Y of the sheet 1, as shown in Figures 1-3, and is manufactured from a hard material such as steel.

[0025] Specifically, the connect rod 7 has a central portion 7a with a circular cross-section, and a pair of ends 7b and a pair of fitting portions 7c located on both sides of the central portion 7a, as shown in Figures 5(a) to (c).

[0026] The end portion 7b has a shape that is close to an ellipse, corresponding to the substantially elliptical rod insertion hole 52a of the cam 50 (see Figures 8a and 9). Specifically, the end portion 7b has a pair of recesses 7e that are recessed radially inward at opposing radially opposite positions.

[0027] The end 7b of the connect rod 7 is inserted into the substantially elliptical rod insertion hole 52a of the cam 50, thereby coaxially coupling the connect rod 7 to each of the cams 50 of the pair of reclining mechanisms 6, and enabling it to rotate together with the cams 50 (see Figure 6).

[0028] As shown in Figures 6-7 and 8(a), when the end 7b of the connect rod 7 is inserted into the rod insertion hole 52a of the cam 50, a gap 9 is provided between the inner circumferential surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer circumferential surface 7f of the end 7b of the connect rod 7, similar to the prior art. This makes it possible to absorb undesirable effects on the operability and locking load of the reclining mechanism 6 caused by dimensional variations and twisting of the frame assembly.

[0029] As shown in Figures 5(a) and (c), the fitting portion 7c of the connect rod 7 is the portion that fits with the resin bush 8 located on both sides of the central portion 7a near the end portion 7b (i.e., at a position adjacent to the central portion 7a side of the end portion 7b, or at a position between the central portion 7a and the end portion 7b). The fitting portion 7c has a tapered portion 7d that becomes narrower towards the end portion 7b of the connect rod 7.

[0030] Specifically, the fitting portion 7c has a circular cross-section portion 7h (see Figures 7 and 8(e)) continuous with the central portion 7a, a substantially elliptical cross-section portion 7g (see Figures 7 and 8(c)) continuous with the end portion 7b, and a tapered portion 7d (see Figures 7 and 8(d)) that continuously connects the circular cross-section portion 7h and the substantially elliptical cross-section portion 7g. In the substantially elliptical cross-section portion 7g, a recess 7e is formed that is continuous with the end portion 7b (see Figures 5(a), 8(a)-(b)).

[0031] The tapered portion 7d has a circular cross-section in the part close to the circular cross-sectional portion 7h, but its cross-sectional shape transitions to a substantially elliptical cross-section similar to that of the end portion 7b as it approaches the end portion 7b.

[0032] The resin bush 8 is a cylindrical body made of resin material and has a fitting hole 8e. Specifically, as shown in Figure 4, it comprises a cylindrical main body portion 8a, a flange portion 8b, and a pair of claw portions 8d. The main body portion 8a, the flange portion 8b, and the pair of claw portions 8d are integrally formed in a linear arrangement along the axial direction S (see Figure 3) of the connect rod 7.

[0033] The resin bush 8 is made primarily of a resin material such as plastic to prevent the generation of abnormal noise between the connect rod 7 and the cam 50. Any elastic material such as rubber (e.g., synthetic rubber) or elastomer can be used as the material for the resin bush 8. The material for the resin bush 8 is preferably one that has low contact resistance with the internal gear 30 and frame 3a, and is resistant to wear.

[0034] The resin bush 8 has a fitting hole 8e that can be fitted into the fitting portion 7c near the end 7b of the connect rod 7. The fitting hole 8e is formed to penetrate the main body portion 8a and the flange portion 8b in the axial direction.

[0035] Therefore, as shown in Figures 6-7 and 8(c)-(e), when the fitting portion 7c of the connect rod 7 is fitted into the fitting hole 8e of the resin bush 8, the cylindrical main body portion 8a extends in the axial direction S of the connect rod 7 and can support the connect rod 7 in contact with it around its entire circumference.

[0036] The fitting hole 8e of the resin bush 8 has a shape corresponding to the outer diameter of the fitting portion 7c of the connect rod 7. Specifically, the fitting hole 8e has a circular cross-sectional hole portion 8e1 (see Figures 7 and 8(e)) corresponding to the circular cross-sectional portion 7h of the fitting portion 7c, a tapered hole portion 8e2 (see Figures 7 and 8(d)) corresponding to the tapered portion 7d, and a substantially elliptical cross-sectional hole portion 8e3 (see Figures 7 and 8(c)) corresponding to the substantially elliptical cross-sectional portion 7g.

[0037] The tapered hole portion 8e2 has a tapered shape that allows it to fit into the tapered portion 7d of the connect rod 7. In Figures 7 and 8(d), there is a small gap between the tapered portion 7d and the inner surface of the tapered hole portion 8e2, but this gap may be omitted.

[0038] The flange portion 8b of the resin bush 8 is a disc-shaped portion that protrudes radially outward from the end edge of the main body portion 8a (specifically, the outer end edge in the axial direction S in Figure 3). When the resin bush 8 is fitted into the fitting portion 7c of the connect rod 7, the flange portion 8b can contact the frame 3a of the seat back 3 to which the internal gear 30 is fixed (specifically, the side of the frame 3a opposite to the internal gear 30) from the axial direction S of the connect rod 7 (see Figures 3, 6-7).

[0039] As shown in Figures 4, 6-7, and 8(b), the pair of claw portions 8d protrude from the opposite side of the main body portion 8a on the flange portion 8b, extend in the axial direction S of the connect rod 7, and support the connect rod 7 from both sides.

[0040] As shown in Figure 8(b), the opposing portions 8d1 of the pair of claw portions 8d have a shape (for example, a concave-convex shape) that can fit into the substantially elliptical cross-section portion 7g of the fitting portion 7c of the connect rod 7. Specifically, the opposing portions 8d1 have a convex shape that can fit into a pair of recesses 7e formed in the substantially elliptical cross-section portion 7g of the fitting portion 7c.

[0041] Furthermore, the outer circumferential surface 8d2 of the pair of claw portions 8d, which is the surface opposite to the connect rod 7, has a shape that allows it to be fitted into the bush insertion hole 35 of the internal gear 30, as shown in Figures 6-7. Specifically, as shown in Figure 8(b), the outer circumferential surface 8d2 of the pair of claw portions 8d is curved in an arc shape, and the pair of claw portions 8d has a shape that allows it to be fitted into the bush insertion hole 35 (see Figure 9), which has a circular cross-section. That is, when the pair of claw portions 8d are fitted into the bush insertion hole 35, the arc-shaped outer circumferential surface 8d2 makes surface contact with the inner circumferential surface of the bush insertion hole 35, which has a circular cross-section, so a stable fitting state is obtained.

[0042] In the reclining device 5 configured as described above, when coaxially coupling the end 7b of the connect rod 7 to the reclining mechanism 6, as shown in Figures 2-3 and 6-7, first, the resin bush 8 is fitted to the fitting portion 7c near the end 7b of the connect rod 7. At this time, the end 7b of the connect rod 7 protrudes outward from the resin bush 8.

[0043] Next, the end portion 7b of the connect rod 7 and the pair of claw portions 8d of the resin bush 8 are inserted into the bush insertion hole 35 of the internal gear 30 through the through hole 3b of the frame 3a of the seat back 3. Specifically, the pair of claw portions 8d are fitted into the bush insertion hole 35, and the outer circumferential surfaces 8d2 of the pair of claw portions 8d are brought into contact with the inner circumferential surface and edge of the bush insertion hole 35. At this time, the resin bush 8 positions the connect rod 7 relative to the cam 50 in a state where it is inserted (specifically fitted) into the bush insertion hole 35 of the internal gear 30, such that a gap 9 is formed between the inner circumferential surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer circumferential surface 7f of the end portion 7b of the connect rod 7. As a result, the end portion 7b of the connect rod 7 can be fitted into the bush insertion hole 35 of the internal gear 30 while having a gap 9. Furthermore, when the resin bush 8 is inserted (fitted) into the bush insertion hole 35, it is sufficient that the outer peripheral surfaces 8d2 of the pair of claw portions 8d abut against at least a part of the inner peripheral surface of the bush insertion hole 35, and it is not necessary for them to abut against the edge of the inner peripheral surface of the bush insertion hole 35.

[0044] In the above configuration, the resin bush 8 can rotate together with the connect rod 7 and the cam 50 with its pair of claw portions 8d inserted into the bush insertion holes 35 of the internal gear 30.

[0045] (Detailed configuration of reclining mechanism 6) The detailed configuration of the reclining mechanism 6 of this embodiment will now be described. As mentioned above, in the present invention, the reclining mechanism 6 only needs to include at least an internal gear 30 and a cam 50, and other components may be modified as appropriate.

[0046] The reclining mechanism 6 is installed between the frame 2a of the seat cushion 2 and the frame 3a of the seat back 3 (see Figures 2-3).

[0047] As shown in Figure 9, the reclining mechanism 6 comprises a guide bracket 20, an internal gear 30, a spiral spring 40, a cam 50, four locking plates 60A to 60D, and a mounting ring 70.

[0048] As shown in Figures 3 and 6, the guide bracket 20 is fixed to the rear of the frame 2a (specifically the side frame) of the seat cushion 2. The internal gear 30 is fixed to the lower part of the frame 3a (specifically the side frame) of the seat back 3.

[0049] Furthermore, if the frame 2a of the seat cushion 2 shown in Figure 3 is located inside the frame 3a of the seat back 3, the internal gear 30 can be fixed to the frame 2a of the seat cushion 2, and the guide bracket 20 can be fixed to the frame 3a of the seat back 3.

[0050] As shown in Figure 9, the guide bracket 20 is formed in a disc shape, with a mounting hole 22 formed through its center for arranging the spiral spring 40. The outer end 41 of the spiral spring 40 engages with the engagement groove 22a provided on the inner circumferential surface of the mounting hole 22.

[0051] The internal gear 30 is formed in a circular shape in plan view and has a substantially concave cross-section. Internal teeth 32 are formed on the inner circumferential surface of the concave portion 31, and the concave portion 31 is positioned opposite the inner surface 20a (see Figure 6) of the guide bracket 20. The internal gear 30 is connected to the frame 3a of the seat back 3 via a connecting projection 34 that protrudes to the right rear side of the page in Figure 9.

[0052] The guide bracket 20 and the internal gear 30 are positioned with the guide bracket 20 and the concave portion 31 of the internal gear 30 facing each other, with the end face 31a1 of the peripheral wall 31a of the concave portion 31 abutting against the surface of the guide bracket 20, and are positioned by the mounting ring 70.

[0053] The mounting ring 70 has an annular bottom plate portion 71 formed in a substantially circular, annular shape with a predetermined width, and an annular side plate portion 72 extending in a direction substantially perpendicular to the outer peripheral edge of the annular bottom plate portion 71, that is, along the outer peripheral surface 31a2 of the peripheral wall 31a of the internal gear 30. In other words, the mounting ring 70 is formed in a shape such that the cross-sectional shape along the radial direction when the annular bottom plate portion 71 and the annular side plate portion 72 are combined is substantially L-shaped.

[0054] In this embodiment, the mounting ring 70 is positioned so that the guide bracket 20 and the concave portion 31 of the internal gear 30 are facing each other, and the locking mechanism, including the spiral spring 40, cam 50, and lock plates 60A to 60D, is housed in its internal space. The annular side plate portion 72 is then placed over the guide bracket 20, with its edge 72a extending beyond the outer circumferential surface 31a2 of the peripheral wall 31a of the internal gear 30, and reaching the outer circumferential surface 21b of the guide bracket 20 located on the side beyond the outer circumferential surface 31a2 (the left front side of the page in Figure 9). When assembled in this manner, the central protrusion of the internal gear 30 is exposed outward from the inner circumference of the annular bottom plate portion 71 (towards the right rear of the page in Figure 9). After the mounting ring 70 is installed in this manner, the portion of the annular side plate portion 72 facing the outer circumferential surface 21b of the guide bracket 20 is welded and fixed to the outer circumferential surface 21b. Therefore, when the seat back 3 rotates relative to the seat cushion 2, with the guide bracket 20 fixed to the frame 2a of the seat cushion 2, for example, and the connecting projection 34 of the internal gear 30 fixed to the frame 3a of the seat back 3, for example, the guide bracket 20 and the internal gear 30 rotate relative to each other. The mounting ring 70 rotates relative to the internal gear 30 together with the guide bracket 20, the radial movement of the internal gear 30 is restricted by the annular side plate portion 72 of the mounting ring 70, and the axial movement of the internal gear 30 is restricted by the annular bottom plate portion 71.

[0055] The cam 50 is a component for reciprocating the lock plates 60A to 60D in the radial direction of the cam 50. The cam 50 is provided with four engaging protrusions 51, 51 that extend in a roughly arc-shaped and angular manner at equal intervals in the circumferential direction, corresponding to the four lock plates 60A to 60D. In addition, the main body portion 52 of the cam 50, excluding the engaging protrusions 51, 51, has four stepped portions 52b, 52b formed at predetermined angles from the base of each engaging protrusion 51, 51, with the outer diameter increasing. The cam 50 is integrally fixed to one surface of the spacer plate 55, and a rod insertion hole 52a is formed through the center of the cam 50, through which the end portion 7b of the connect rod 7 is inserted. When the connect rod 7 is rotated in either forward or reverse direction using an operating member (not shown) attached to the end portion 7b of the connect rod 7, the cam 50 follows and rotates in the same direction.

[0056] The cam 50 is provided with a first shaft portion 53 that protrudes toward the guide bracket 20 from around the rod insertion hole 52a on the surface facing the guide bracket 20. The first shaft portion 53 is formed with an outer diameter smaller than the inner diameter of the spiral spring 40, and an engagement groove 53a is cut out of the first shaft portion 53 from the outer circumferential surface toward the center. The spiral spring 40 is positioned on the outer circumference of the first shaft portion 53, and its inner end portion 42 is engaged with the engagement groove 53a of the first shaft portion 53 (see Figure 8(a)), and is positioned together with the first shaft portion 53 in the placement hole 22 of the guide bracket 20. The outer end portion 41 of the spiral spring 40 is engaged with the engagement groove 22a formed on the inner circumferential surface of the placement hole 22 of the guide bracket 20, thereby biasing the cam 50 in one rotational direction.

[0057] The internal gear 30 is provided with a second shaft portion 36 that protrudes toward the cam 50 at its center. This second shaft portion 36 is inserted into a bearing hole (not shown) formed in the cam 50, thereby rotatably supporting the cam 50.

[0058] In this embodiment, four lock plates 60A to 60D are used. The four lock plates 60A to 60D are positioned to correspond to four angular engaging protrusions 51, 51 formed on the cam 50. The lock plates 60A to 60D can slide radially along a radially extending guide groove (not shown) formed on the guide bracket 20.

[0059] The lock plates 60A to 60D and the cam 50 are biased radially outward by the unidirectional rotation of the cam 50 due to the elasticity of the spiral spring 40, and displaced towards the center by the reverse rotation of the cam 50 by the connect rod 7. Each lock plate 60A to 60D has a substantially rectangular shape in plan view. Each lock plate 60A to 60D is also provided with engaging grooves 61, 61 that are cut out in a substantially arc shape from the inner circumferential surface. When the cam 50 rotates clockwise, each engaging projection 51, 51 engages with each engaging groove 61, 61, pulling the lock plates 60A to 60D toward the center of the cam 50. When the cam 50 is biased by the spiral spring 40 and rotates counterclockwise, the engaging projections 51, 51 and the stepped portions 52b, 52b press the lock plates 60A to 60D radially outward from the cam 50. External teeth 63, 63 are formed on the outer circumferential surfaces of the lock plates 60A to 60D, and when pressed radially outward, they engage with the internal teeth 32 of the internal gear 30, locking the guide bracket 20 and the internal gear 30 so that they cannot rotate relative to each other. This makes it possible to fix the seat back 3 at any tilt angle.

[0060] (Features of this embodiment) (1) The reclining device 5 of this embodiment holds the seat back 3 shown in Figure 1 so as to be tiltable relative to the seat cushion 2 and fixes it at any tilt angle.

[0061] As shown in Figures 1 to 6, the reclining device 5 comprises a pair of reclining mechanisms 6, each having an internal gear 30 fixed to the frame of either the seat cushion 2 or the seat back 3 (in this embodiment, the frame 3a of the seat back 3) and positioned on both sides of the seat 1 in the width direction Y, and a cam 50 positioned parallel to the internal gear 30 in its thickness direction (i.e., the width direction Y), and a connect rod 7 extending along the width direction Y of the seat 1, coaxially coupled to each cam 50 of the pair of reclining mechanisms 6, and rotating together with the cam 50.

[0062] The reclining device 5 of this embodiment is a cylindrical body having a fitting hole 8e, and further comprises a resin bush 8 fitted to a fitting portion 7c near the end 7b of the connect rod 7.

[0063] As shown in Figures 6-7, the cam 50 has a rod insertion hole 52a into which the end 7b of the connect rod 7 can be inserted. The internal gear 30 has a bush insertion hole 35 at the center of the internal gear 30 into which a resin bush 8 can be inserted.

[0064] As shown in Figures 6-7 and 8(a), the fitting portion 7c near the end 7b of the connect rod 7 fits into the fitting hole 8e of the resin bush 8, and the end 7b of the connect rod 7 protrudes to the outside of the resin bush 8. The resin bush 8 is inserted into the bush insertion hole 35 of the internal gear 30 in contact with the inner surface of the bush insertion hole 35 so as to position the connect rod 7 relative to the cam 50 with a gap 9 formed between the inner surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer surface 7f of the connect rod 7.

[0065] With this configuration, the resin bush 8 is inserted into the bush insertion hole 35 of the internal gear 30 in contact with its inner surface, so as to position the connect rod 7 relative to the cam 50 with a gap 9 formed between the inner surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer surface 7f of the connect rod 7. This allows the resin bush 8 to restrict the radial relative movement of the connect rod 7 relative to the cam 50, thereby preventing interference noise between the cam 50 and the connect rod 7. As a result, it is possible to effectively prevent abnormal noise while allowing a gap 9 between the inner surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer surface 7f of the connect rod 7.

[0066] Furthermore, the resin bush 8 is not positioned between the cam 50 and the connect rod 7 to position them relative to each other. Instead, it is inserted into the bush insertion hole 35 of the internal gear 30 and positions the connect rod 7 in this state. Therefore, it is not subject to dimensional constraints or rigidity constraints imposed by the gap 9 between the cam 50 and the connect rod 7. As a result, the resin bush 8 can be set to dimensions and rigidity that are less prone to wear compared to an elastic ring like those in the conventional technology (the structure described in Patent Document 1 above).

[0067] (2) In the reclining device 5 of this embodiment, the fitting hole 8e of the resin bush 8 has a shape corresponding to the outer diameter of the fitting portion 7c of the connect rod 7. That is, as shown in Figures 7 and 8(c) to (e), the fitting hole 8e has a circular cross section 8e1, a tapered section 8e2, and a substantially elliptical cross section 8e3.

[0068] With this configuration, the installation of the resin bush 8 to the fitting portion 7c near the end 7b of the connect rod 7 is completed simply by fitting the fitting portion 7c near the end 7b of the connect rod 7 into the fitting hole 8e of the resin bush 8, thus improving work efficiency. Moreover, the simple configuration of the connect rod 7 and resin bush 8 prevents the resin bush 8 from coming out axially from the internal gear 30, and also prevents the resin bush 8 from falling off the connect rod 7.

[0069] (3) In the reclining device 5 of this embodiment, as shown in Figures 3-4 and 6-7, the resin bush 8 has a flange portion 8b that abuts against the frame 3a of the seat back 3 to which the internal gear 30 is fixed from the axial direction S of the connect rod 7.

[0070] With this configuration, the flange portion 8b of the resin bush 8 comes into contact with the frame 3a of the seat back 3 from the axial direction S of the connect rod 7, thereby restricting the movement of the resin bush 8 in the axial direction S.

[0071] Furthermore, the flange portion 8b seals the gap between the resin bush 8 and the inner surface of the through hole 3b of the frame 3a, thereby preventing foreign matter from entering the reclining mechanism 6 through the through hole 3b.

[0072] (4) In the reclining device 5 of this embodiment, the resin bush 8 has a cylindrical main body portion 8a that extends in the axial direction S of the connect rod 7 and supports the connect rod 7 in contact with it around its entire circumference.

[0073] With this configuration, the cylindrical main body portion 8a of the resin bush 8 supports the connect rod 7 in contact with it around its entire circumference, which further restricts the radial relative movement of the connect rod 7 with respect to the cam 50, thereby improving the noise prevention effect.

[0074] (5) In the reclining device 5 of this embodiment, as shown in Figures 5 to 7, the fitting portion 7c of the connect rod 7 has a tapered portion 7d that becomes narrower towards the end 7b of the connect rod 7. As shown in Figures 7 and 8(d), the fitting hole 8e of the resin bush 8 has a tapered hole portion 8e2 that can be fitted into the tapered portion 7d of the connect rod 7.

[0075] With this configuration, the tapered portion 7d formed on the fitting portion 7c near the end 7b of the connect rod 7 fits into the tapered hole portion 8e2 of the fitting hole 8e of the resin bush 8, restricting the axial movement of the resin bush 8. As a result, without increasing the number of parts, a simple configuration using the combination of the connect rod 7 and the resin bush 8 prevents the resin bush 8 from coming out of the internal gear 30 in the axial direction, and also prevents the resin bush 8 from falling off the connect rod 7.

[0076] (6) In the reclining device 5 of this embodiment, as shown in Figures 4, 6-7 and 8(b), the resin bush 8 has a pair of claw portions 8d that extend in the axial direction S of the connect rod 7 and support the connect rod 7 from both sides.

[0077] With this configuration, the pair of claws 8d of the resin bush 8 support the connect rod 7 from both sides, which further restricts the radial relative movement of the connect rod 7 with respect to the cam 50, thereby improving the effect of preventing the generation of abnormal noise.

[0078] (7) In the reclining device 5 of this embodiment, as shown in Figure 8(b), the opposing portions 8d1 of the pair of claw portions 8d that face each other have a shape that can be fitted into the fitting portion 7c of the connect rod 7. That is, the opposing portions 8d1 have a convex shape that can be fitted into the recess 7e of the substantially elliptical cross-sectional portion 7g of the fitting portion 7c.

[0079] With this configuration, the opposing portions 8d1 of the pair of claw portions 8d of the resin bush 8 engage with the fitting portion 7c near the end 7b of the connect rod 7, thereby further restricting the radial relative movement of the connect rod 7 with respect to the cam 50, and improving the effect of preventing the generation of abnormal noise.

[0080] (8) In the reclining device 5 of this embodiment, as shown in Figures 6-7 and 8(b), each pair of claw portions 8d has an outer peripheral surface 8d2 which is the side opposite to the connect rod 7. Each outer peripheral surface 8d2 of the pair of claw portions 8d has a shape that can be fitted into the bush insertion hole 35 of the internal gear 30. That is, each outer peripheral surface 8d2 of the pair of claw portions 8d has an arc shape that can be fitted into the bush insertion hole 35 which has a circular cross-section.

[0081] With this configuration, the pair of claws 8d of the resin bush 8 fit into the bush insertion hole 35 of the internal gear 30, improving the effect of the pair of claws 8d supporting the connect rod 7 from both sides, and making it possible to further restrict the radial relative movement of the connect rod 7 with respect to the cam 50. In addition, the resin bush 8 and the connect rod 7 can be easily positioned simply by fitting the pair of claws 8d into the bush insertion hole 35, improving the workability of assembling the reclining device 5.

[0082] (9) The seat 1 of this embodiment, as shown in Figures 1 to 7, comprises a seat cushion 2, a seat back 3 positioned at the rear of the seat cushion 2 and tiltable in the front-rear direction X of the seat 1, and a reclining device 5 having the above configuration for fixing the seat back 3 at an arbitrary tilt angle.

[0083] The seat 1 described above includes a reclining device 5 in which a resin bush 8 is inserted into the bush insertion hole 35 of the internal gear 30 in contact with the inner surface of the bush insertion hole 35, so as to position the connect rod 7 with a gap 9 formed between the inner surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer surface 7f of the connect rod 7. This allows the resin bush 8 to restrict the radial relative movement of the cam 50 on the connect rod 7. As a result, it is possible to effectively prevent abnormal noise while allowing a gap 9 between the inner surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer surface 7f of the connect rod 7.

[0084] (modified version) As shown in Figures 4 and 7, the main body portion 8a of the resin bush 8 in the above embodiment has a length that allows it to fit over the entire fitting portion 7c of the connect rod 7, that is, a length that allows it to fit not only over the substantially elliptical cross-section portion 7g but also over the circular cross-section portion 7h and the tapered portion 7d. However, the present invention does not particularly limit the length of the main body portion 8a of the resin bush 8.

[0085] Therefore, as a modified example of the present invention, as shown in Figures 10 to 12, the length of the main body portion 8a of the resin bush 8 may be changed to a length that can be fitted only to the substantially elliptical cross-sectional portion 7g.

[0086] In the modified examples shown in Figures 10-12, the resin bush 8 can be miniaturized by shortening the main body portion 8a.

[0087] In the modified examples shown in Figures 10-12, the substantially elliptical cross-sectional portion 7g of the connect rod 7 (i.e., the portion having the recess 7e in Figures 8(b)-(c)) fits into the fitting hole 8e of the main body portion 8a of the resin bush 8 (specifically, the substantially elliptical cross-sectional hole portion 8e3 as shown in Figure 8(c)) and the convex opposing portions 8d1 of the pair of claw portions 8d, thereby restricting the radial relative movement of the connect rod 7 with respect to the cam 50, and improving the effect of preventing the generation of abnormal noise.

[0088] Furthermore, in this modified example, as shown in Figure 12, the resin bush 8 is not fitted with the tapered portion 7d of the connect rod 7. However, because the tapered portion 7d is positioned near the mounting position of the resin bush 8, it is possible to prevent the resin bush 8 from shifting axially and from coming loose (specifically, from coming loose from the through hole 3b of the frame 3a and the bush insertion hole 35 of the internal gear 30).

[0089] As shown in Figures 10 and 11(c) and (e), the resin bush 8 of this modified form has a pair of opposing planes on the outer circumferential surface of the main body 8a. Therefore, the rotation angle of the resin bush 8 and the connecting rod 7 can be easily adjusted using a tool.

[0090] Furthermore, as another modification of the present invention, as shown in Figures 13 to 15, the resin bush 8 may have no main body portion 8a and may have an engaging portion 8f that can engage with the frame 3a.

[0091] The engaging portion 8f is configured to engage with the frame 3a of the seat back 3 to which the internal gear 30 is fixed, and is composed of, for example, a claw that can engage with the edge of the through hole 3b of the frame 3a. The engaging portion 8f protrudes radially outward from the resin bush 8 from each of the outer peripheral surfaces 8d2 of a pair of claw portions 8d.

[0092] In the modified configuration shown in Figures 13-15, the engaging portion 8f of the resin bush 8 engages with the frame 3a of the seat back 3 to which the internal gear 30 is fixed (specifically, the edge of the through hole 3b). This prevents the resin bush 8 from falling off the frame 3a. Furthermore, since the resin bush 8 is securely fixed by both the frame 3a and the internal gear 30, the resin bush 8 can reliably restrict the radial relative movement of the cam 50 relative to the cam 50 on the connect rod 7, thereby improving the noise prevention effect.

[0093] Furthermore, if the internal gear 30 is fixed to the frame 2a of the seat cushion 2, the engaging portion 8f should be configured to engage with the frame 2a of the seat cushion 2.

[0094] Furthermore, in the modified configuration shown in Figures 13-15, the pair of claw portions 8d of the resin bush 8 each have an outer peripheral surface 8d2 that is the side opposite to the connect rod 7. The outer peripheral surface 8d2 has a tapered shape that slopes toward the center of the bush insertion hole 35 as it approaches the tip of the claw portion 8d, and contacts the edge of the bush insertion hole 35 of the internal gear 30. The edge is included in the inner peripheral surface of the bush insertion hole 35. In this configuration, by inserting the pair of claw portions 8d of the resin bush 8 into the bush insertion hole 35 with the edge of the bush insertion hole 35 in contact with the bush insertion hole 35, it is possible to position the connect rod 7 relative to the cam 50 with a gap 9 formed between the inner peripheral surface 52a1 of the rod insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the connect rod 7.

[0095] With this configuration, the tapered outer surfaces 8d2 of the pair of claw portions 8d of the resin bush 8 abut against the edge of the bush insertion hole 35 of the internal gear 30, thereby ensuring that the contact between the resin bush 8 and the internal gear 30 is reliably maintained. Furthermore, this configuration makes it possible to absorb dimensional variations in either the bush insertion hole 35 or the claw portions 8d, or both.

[0096] In the modified examples shown in Figures 13-15 above, miniaturization of the resin bush 8 can be achieved by eliminating the main body portion 8a.

[0097] Furthermore, as shown in Figure 15, although the resin bush 8 is not fitted with the tapered portion 7d of the connect rod 7, the tapered portion 7d is positioned near the mounting position of the resin bush 8, which makes it possible to prevent the resin bush 8 from shifting axially and coming loose (specifically, from coming loose from the through hole 3b of the frame 3a and the bush insertion hole 35 of the internal gear 30).

[0098] <Summary of Embodiments> The embodiments described above can be summarized as follows.

[0099] The reclining device of this embodiment comprises a pair of reclining mechanisms each having an internal gear fixed to the frame of one of the seat cushion or seat back, and a cam arranged in line with the thickness direction of the internal gear, and a connect rod extending along the width direction of the seat and coaxially coupled to the cam of each of the pair of reclining mechanisms, and rotating together with the cam, and holds the seat back tiltably relative to the seat cushion and fixes it at an arbitrary tilt angle, and is a cylindrical body having a fitting hole, which is fitted into a fitting portion formed near the end of the connect rod The present invention relates to a cam equipped with a resin bush, wherein the cam has a rod insertion hole into which the end of the connect rod can be inserted, the internal gear has a bush insertion hole at the center of the internal gear into which the resin bush can be inserted, the fitting portion near the end of the connect rod fits into the fitting hole of the resin bush, the end of the connect rod protrudes to the outside of the resin bush, and the resin bush is inserted into the bush insertion hole of the internal gear in contact with the inner surface of the bush insertion hole, so as to position the connect rod relative to the cam with a gap formed between the inner surface of the rod insertion hole of the cam and the outer surface of the connect rod. The inner surface of the bush insertion hole also includes the edge of the bush insertion hole.

[0100] In this configuration, the resin bush is inserted into the bush insertion hole of the internal gear in contact with the inner surface of the bush insertion hole, so as to position the connect rod relative to the cam with a gap formed between the inner surface of the rod insertion hole of the cam and the outer surface of the connect rod. This allows the resin bush to restrict the radial relative movement of the cam relative to the cam on the connect rod, thereby preventing interference noise between the cam and the connect rod. As a result, it is possible to effectively prevent abnormal noise while allowing a gap between the inner surface of the rod insertion hole of the cam and the outer surface of the connect rod.

[0101] In the above-described reclining device, it is preferable that the fitting hole of the resin bush has a shape corresponding to the outer diameter of the fitting portion of the connect rod.

[0102] With this configuration, the installation of the resin bushing to the connect rod is completed simply by fitting the mating portion near the end of the connect rod into the mating hole of the resin bushing, resulting in efficient work. Moreover, the simple configuration of the connect rod and resin bushing prevents the resin bushing from coming out axially from the internal gear, and also prevents the resin bushing from falling off the connect rod.

[0103] In the above-described reclining device, it is preferable that the resin bushing has a flange portion that contacts the frame of the seat cushion or seat back to which the internal gear is fixed, from the axial direction of the connect rod.

[0104] With this configuration, the flange portion of the resin bush comes into contact with the frame of the seat cushion or seat back from the axial direction of the connect rod, thereby restricting the axial movement of the resin bush.

[0105] In the above-described reclining device, it is preferable that the resin bush has a cylindrical body portion that extends in the axial direction of the connect rod and supports the connect rod in contact with it around its entire circumference.

[0106] With this configuration, the cylindrical body of the resin bush supports the connect rod in contact with it around its entire circumference, which further restricts the radial relative movement of the connect rod with respect to the cam, thereby improving the noise prevention effect.

[0107] In the above-described reclining device, it is preferable that the fitting portion of the connect rod has a tapered shape that becomes narrower towards the end of the connect rod, and the fitting hole of the resin bush has a tapered hole portion that can be fitted into the tapered portion of the connect rod.

[0108] With this configuration, the tapered portion formed in the fitting portion near the end of the connect rod fits into the tapered hole portion of the fitting hole of the resin bush, restricting the axial movement of the resin bush. As a result, without increasing the number of parts, it is possible to prevent the resin bush from coming out of the internal gear axially with a simple configuration of a connect rod and resin bush combination, and furthermore, it is possible to prevent the resin bush from falling off the connect rod.

[0109] In the above-described reclining device, it is preferable that the resin bushing has a pair of claws that extend in the axial direction of the connect rod and support the connect rod from both sides.

[0110] With this configuration, the pair of claws of the resin bushing support the connect rod from both sides, which further restricts the radial relative movement of the connect rod with respect to the cam, thereby improving the effect of preventing abnormal noise.

[0111] In the above-described reclining device, it is preferable that the opposing portions of the pair of claws have a shape that allows them to fit into the fitting portion of the connecting rod.

[0112] With this configuration, the opposing portions of the pair of claws of the resin bush fit into the fitting portion near the end of the connect rod, which further restricts the radial relative movement of the connect rod with respect to the cam, thereby improving the effect of preventing the generation of abnormal noise.

[0113] In the above-described reclining device, it is preferable that the pair of claw portions each have an outer peripheral surface that is opposite to the connect rod, and that the outer peripheral surface has a shape that can be fitted into the bush insertion hole of the internal gear.

[0114] With this configuration, the pair of claws of the resin bush fit into the bush insertion hole of the internal gear, improving the effect of the pair of claws supporting the connect rod from both sides, and further restricting the radial relative movement of the connect rod with respect to the cam. In addition, the resin bush and connect rod can be easily positioned simply by fitting the pair of claws into the bush insertion hole, improving the workability of assembling the reclining device.

[0115] In the above-described reclining device, the pair of claws each have an outer peripheral surface that is opposite to the connect rod, and the outer peripheral surface has a tapered shape that slopes toward the center of the bush insertion hole as it approaches the tip of the claw, and preferably contacts the edge of the bush insertion hole of the internal gear.

[0116] With this configuration, the tapered outer surfaces of the pair of claws of the resin bush abut against the edge of the bush insertion hole of the internal gear, thereby ensuring that the contact between the resin bush and the internal gear is reliably maintained. Furthermore, this configuration makes it possible to absorb dimensional variations in either the bush insertion hole or the claws, or both.

[0117] In the above-described reclining device, it is preferable that the resin bushing further has an engaging portion that can engage with the frame of the seat cushion or the seat back to which the internal gear is fixed.

[0118] With this configuration, the engaging portion of the resin bush engages with the frame to which the internal gear of the seat cushion or seat back frame is fixed, thereby preventing the resin bush from falling off the frame. Furthermore, since the resin bush is securely fixed by both the frame and the internal gear, the resin bush can reliably restrict the radial relative movement of the cam with respect to the cam in the connect rod, thereby improving the noise prevention effect.

[0119] The seat of this embodiment is characterized by comprising a seat cushion, a seat back positioned at the rear of the seat cushion and capable of tilting in the front-to-back direction of the seat, and the above-mentioned reclining device for fixing the seat back at an arbitrary tilt angle.

[0120] The above-described seat is equipped with a reclining device in which a resin bush is inserted into the bush insertion hole of the internal gear in a manner that contacts the inner surface of the bush insertion hole, so as to position the connect rod with a gap formed between the inner surface of the cam's rod insertion hole and the outer surface of the connect rod. This restricts the radial relative movement of the cam relative to the cam on the connect rod. As a result, it is possible to effectively prevent abnormal noise while allowing a gap between the inner surface of the cam's rod insertion hole and the outer surface of the connect rod.

[0121] According to the reclining device and seat of this embodiment, effective noise prevention can be achieved while allowing a gap between the cam and the connecting rod.

Claims

1. A pair of reclining mechanisms each having an internal gear positioned on both sides in the width direction of the seat and fixed to the frame of either the seat cushion or the seat back, and cams positioned parallel to the internal gear in the thickness direction, The seat comprises a connecting rod that extends along the width direction of the seat, is coaxially coupled to each of the cams of the pair of reclining mechanisms, and rotates together with the cams, A reclining device that holds the seat back so as to be tiltable relative to the seat cushion and fixes it at an arbitrary tilt angle, It is a cylindrical body having a fitting hole, and is equipped with a resin bush fitted into a fitting portion formed near the end of the connect rod, The cam has a rod insertion hole into which the end of the connect rod can be inserted, The internal gear has a bush insertion hole at the center of the internal gear into which the resin bush can be inserted. The fitting portion near the end of the connect rod fits into the fitting hole of the resin bush, and the end of the connect rod protrudes to the outside of the resin bush. The resin bush is inserted into the bush insertion hole of the internal gear in contact with the inner circumferential surface of the bush insertion hole, so as to position the connect rod relative to the cam with a gap formed between the inner circumferential surface of the rod insertion hole of the cam and the outer circumferential surface of the connect rod. The fitting portion of the connecting rod has a tapered shape that becomes narrower towards the end of the connecting rod. The fitting hole of the resin bush has a tapered hole portion that can be fitted into the tapered portion of the connect rod. A reclining device characterized by the following features.

2. In the reclining device according to claim 1, the fitting hole of the resin bush has a shape corresponding to the outer diameter of the fitting portion of the connect rod. A reclining device characterized by the following features.

3. In the reclining device according to claim 1 or 2, The resin bush has a flange portion that contacts the frame of the seat cushion or seat back to which the internal gear is fixed, from the axial direction of the connect rod. A reclining device characterized by the following features.

4. In the reclining device according to any one of claims 1 to 3, The resin bush has a cylindrical body portion that extends in the axial direction of the connect rod and supports the connect rod in contact with it around its entire circumference. A reclining device characterized by the following features.

5. In the reclining device according to any one of claims 1 to 4, The resin bush has a pair of claws that extend in the axial direction of the connect rod and support the connect rod from both sides. A reclining device characterized by the following features.

6. In the reclining device according to claim 5, The opposing portions of the pair of claws are the fitting portion of the connect rod. Having a shape that can be fitted, A reclining device characterized by the following features.

7. In the reclining device according to claim 5 or 6, Each of the pair of claw portions has an outer peripheral surface that is the side opposite to the connect rod, The outer circumferential surface has a shape that can be fitted into the bush insertion hole of the internal gear. A reclining device characterized by the following features.

8. In the reclining device according to claim 5 or 6, Each of the pair of claw portions has an outer peripheral surface that is the side opposite to the connect rod, The outer circumferential surface has a tapered shape that slopes toward the center of the bush insertion hole as it approaches the tip of the claw portion, and contacts the edge of the bush insertion hole of the internal gear. A reclining device characterized by the following features.

9. In the reclining device according to any one of claims 1 to 8, The reclining device is characterized in that the resin bushing further has an engaging portion that can engage with the frame of the seat cushion or the seat back to which the internal gear is fixed.

10. Seat cushion and, A seat back positioned at the rear of the aforementioned seat cushion and capable of tilting in the front-to-back direction of the seat, The reclining device according to claim 1, which fixes the seat back at an arbitrary tilt angle, is further comprising: A sheet characterized by the following features.

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