Tilting device and seat

Abstract

The present invention provides an inclination device that can effectively prevent abnormal noise while allowing a clearance between a cam and a connecting rod. The inclination device (5) includes: a pair of inclination mechanisms (6) each having an internal gear (30) and a cam (50); a connecting rod (7) coaxially coupled to each cam (50) and rotating together with the cam (50); and a resin bushing (8) having a fitting hole (8e) that can be fitted to a fitting portion (7c) near an end portion (7b) of the connecting rod (7). The resin bushing (8) is inserted into the bushing insertion hole (35) of the internal gear (30) in a state of abutting against the inner peripheral surface of the bushing insertion hole (35), so as to position the connecting rod (7) relative to the cam (50) in a state where a clearance (9) is formed between the inner peripheral surface (52a1) of the connecting rod insertion hole (52a) of the cam (50) and the outer peripheral surface (7f) of the connecting rod (7).

Description

Technical Field

[0001] The present invention relates to a tilting device and a seat including the tilting device. Background Art

[0002] In conventional seats for vehicles and the like, there is a seat including a tilting device that can fix a seat backrest (backrest portion) at an arbitrary tilting angle with respect to a seat cushion (seat portion) and can tilt the seat backrest in the front - rear direction with respect to the seat cushion.

[0003] The tilting device includes: a pair of tilting mechanisms (angle adjusters) disposed at positions on both sides in the width direction of the seat; and a link disposed to extend in the width direction of the seat and connecting the pair of tilting mechanisms.

[0004] Each of the pair of tilting mechanisms includes a cam. Each cam is coaxially coupled to both end portions of the link and can rotate together with the link. When the link receives a rotational operating force from outside the seat, the cam rotates in a specified direction together with the link and separates a locking plate disposed around the cam from an internal gear, thereby enabling unlocking.

[0005] In the case of adopting the structure in which the end portion of the link is coaxially coupled to the cam as described above, for 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 link. That is, due to dimensional deviations or distortions (i.e., offsets or deformations during assembly of the skeleton assembly) of the skeleton assembly (i.e., a combination of the skeletons of the seat backrest and seat cushion and the tilting mechanism assembled to the skeleton), it may have an adverse effect on the operability and locking load of the tilting mechanism. In order to absorb such effects, it is necessary to provide the above - mentioned gap.

[0006] Since it is necessary to provide the gap between the cam and the link as described above, in the conventional tilting device, the following problem occurs: the cam and the link interfere with each other due to the shaking of the vehicle body or an external impact, and abnormal noise (rattling sound) is generated.

[0007] Therefore, in order to prevent abnormal noise from occurring while allowing the gap between the cam and the link, in the tilting device described in Patent Document 1, abnormal noise is suppressed by interposing a narrow elastic ring between the cam and the link.

[0008] However, in the case of adopting the structure in which a narrow elastic ring is interposed between the cam and the link as described in Patent Document 1, the relative positioning of the cam and the link is performed by the narrow elastic ring. Therefore, it is difficult to effectively prevent abnormal noise while allowing the gap between the cam and the link. The reasons are as follows.

[0009] First, the size of the elastic ring is limited by the thickness of the gap between the cam and the connecting rod. Therefore, it is structurally difficult to increase the rigidity by increasing the thickness of the elastic ring. Under such a limitation on the size of the elastic ring, if the rigidity of the elastic ring is increased to prevent the above abnormal noise, it will be difficult to insert the elastic ring into the gap between the cam and the connecting rod, which will affect the assembly of the tilting device. On the other hand, if the rigidity of the elastic ring is reduced, the holding force of the connecting rod will decrease, and abnormal noise will occur as long as the connecting rod moves slightly and touches the cam. Therefore, it is difficult to effectively prevent abnormal noise while allowing the above gap.

[0010] Prior art documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Gazette No. 3972648 Summary of the invention

[0013] The present invention is made in view of the above situation, and its object is to provide a tilting device that can effectively prevent abnormal noise while allowing a gap between the cam and the connecting rod.

[0014] The tilting device of the present invention includes: a pair of tilting mechanisms, which are respectively arranged on both sides in the width direction of the seat, and each has an internal gear and a cam. The internal gear is fixed to one of the skeletons of the seat cushion and the seat back, and the cams are arranged side by side in the thickness direction of the internal gear; and a connecting rod, which extends along the width direction of the seat, is coaxially coupled to the cams of the pair of tilting mechanisms respectively, and rotates together with the cams. The tilting device tiltably holds and fixes the seat back relative to the seat cushion at an arbitrary tilt angle, and further includes: a resin bushing, which is a cylindrical body having a fitting hole and is fitted into a fitting portion formed near the end of the connecting rod. Wherein, the cam has a connecting rod insertion hole into which the end of the connecting rod can be inserted, the internal gear has a bushing insertion hole into which the resin bushing can be inserted at the central position of the internal gear, the fitting portion near the end of the connecting rod is fitted with the fitting hole of the resin bushing, the end of the connecting rod protrudes outside the resin bushing, and the resin bushing is inserted into the bushing insertion hole in a state of abutting against the inner peripheral surface of the bushing insertion hole of the internal gear, so as to position the connecting rod relative to the cam in a state where there is a gap between the inner peripheral surface of the connecting rod insertion hole of the cam and the outer peripheral surface of the connecting rod. The edge portion of the above bushing insertion hole is also included in the inner peripheral surface of the bushing insertion hole. Brief description of the drawings

[0015] Figure 1 It is a perspective view showing the overall configuration of a seat equipped with the tilting device according to an embodiment of the present invention.

[0016] Figure 2 It represents Figure 1 An enlarged perspective view of the configuration of the resin bushing and the tilting mechanism near the end of the connecting rod.

[0017] Figure 3 It is Figure 2 A perspective view of the separated state of the connecting rod, resin bushing, and tilting mechanism of

[0018] Figure 4 It is Figure 3 A perspective view of the resin bushing of

[0019] Figure 5 It represents Figure 3 A view of the connecting rod of , where (a) is an enlarged perspective view showing the structure around the end of the connecting rod, (b) is a view when observing the end in (a) from the distal end side, and (c) is a view when observing the structure around the end in (a) from the outer peripheral side.

[0020] Figure 6 It is composed of Figure 2 The connecting rod, resin bushing, and tilting mechanism of combined to form a Figure 1 Schematic cross-sectional view of the main structure of the tilting device of

[0021] Figure 7 It represents Figure 6 An enlarged cross-sectional view of the resin bushing and its peripheral part of

[0022] Figure 8 It is Figure 6 A line cross-sectional view of the connecting rod and its peripheral part of , where (a) is a cross-sectional view along line A - A, (b) is a cross-sectional view along line B - B, (c) is a cross-sectional view along line C - C, (d) is a cross-sectional view along line D - D, and (E) is a cross-sectional view along line E - E.

[0023] Figure 9 It is Figure 3 An exploded perspective view of the tilting mechanism of

[0024] Figure 10 A perspective view of the resin bushing of the improved main body part related to the modification example of the present invention.

[0025] Figure 11 It represents Figure 10 A view of the resin bushing of , where (a) is a side view when observing from the distal end side of the claw part, (b) is a front view, (c) is a side view when observing from the distal end side of the main body part, (d) is a cross-sectional view along line F - F of (c), and (e) is a top view.

[0026] Figure 12 It is Figure 10 The resin bushing of and Figure 6Schematic cross-sectional view of the structure formed by combining the connecting rod and the tilting mechanism.

[0027] Figure 13 It is a perspective view of a small resin bushing having an engaging portion that engages with the skeleton, which is related to another modification of the present invention.

[0028] Figure 14 It shows Figure 13 A view of the resin bushing, where (a) is a side view when viewed from the distal side of the claw portion, (b) is a front view, (c) is a side view when viewed from the side facing the plane of the flange portion, (d) is a cross-sectional view taken along line G-G of (c), and (e) is a top view.

[0029] Figure 15 It is Figure 13 The resin bushing of Figure 6 Schematic cross-sectional view of the structure formed by combining the connecting rod and the tilting mechanism. Detailed Description of the Preferred Embodiment

[0030] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0031] As Figure 1 shown, 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; a seat backrest 3 that is disposed at the rear of the seat cushion 2 to support the back of the seated person and is tiltable relative to the seat cushion 2 in the front-rear direction X of the seat 1; a sliding device 4 that is installed at the lower part of the seat cushion 2; and a tilting device 5.

[0032] The sliding device 4 has a structure that can guide the seat cushion 2 to slide in the front-rear direction X of the seat 1 and fix the seat cushion 2 at an arbitrary position. In addition, in the seat of the present invention, the sliding device 4 is not essential and can be omitted.

[0033] The tilting device 5 has a structure that can fix the seat backrest 3 at an arbitrary tilting angle.

[0034] Specifically, as Figures 2 to 3 shown, the tilting device 5 of the present embodiment includes: a pair of tilting mechanisms 6; a connecting rod 7 that is connected to the pair of tilting mechanisms 6; and a pair of resin bushings 8 that are fitted into fitting portions 7c near both ends 7b of the connecting rod 7.

[0035] The pair of tilting mechanisms 6 are disposed at positions on both sides in the width direction Y of the seat 1. Each tilting mechanism 6 is a mechanism that functions as a clutch for fixing the seat backrest 3 at an arbitrary tilting angle, and its detailed structure will be described separately later.

[0036] As Figure 3 , Figure 6 andFigure 9 As shown, the tilting mechanism 6 of the present embodiment includes: an internal gear 30, which is fixed to the frame of one of the seat cushion 2 and the seat back 3 by fitting or welding, etc. In the present embodiment, it is the frame 3a of the seat back 3 (specifically, the side frame constituting the side portion of the seat back 3); a cam 50, which is arranged side by side with respect to the internal gear 30 in its thickness direction (that is, Figure 3 the axial direction S of the link 7).

[0037] That is, in the tilting device of the present invention, the tilting mechanism 6 only needs to include at least the internal gear 30 and the cam 50, and other structural elements can be appropriately changed.

[0038] As Figures 6 to 7 , Figure 8 shown in (a) of Figure 9 and Figure 8 shown in (a) of Figure 9 , the cam 50 has a link insertion hole 52a into which the end 7b of the link 7 can be inserted. The link insertion hole 52a has a substantially elliptical cross-sectional shape (specifically, a circular shape flattened from both sides to the inside) (especially refer to

[0039] As Figures 6 to 7 and Figure 9 shown, the internal gear 30 has a bushing insertion hole 35 at the center position of the internal gear 30 into which the resin bushing 8 can be inserted after passing through the through hole 3b formed in the frame 3a (refer to Figure 3 , Figures 6 to 7 ). The bushing insertion hole 35 has a circular cross-section.

[0040] As Figures 1 to 3 shown, the link 7 is a rod-shaped member arranged to extend along the width direction Y of the seat 1, and is made of a hard material such as steel.

[0041] Specifically, as Figure 5 shown in (a) to (c) of

[0042] , the link 7 has: a central portion 7a with a circular cross-section; a pair of end portions 7b and a pair of fitting portions 7c arranged on both sides of the central portion 7a. Figure 8 shown in (a) of Figure 9 and

[0043] Based on the end 7b of the connecting rod 7 being inserted into the substantially elliptical connecting rod insertion hole 52a of the cam 50, the connecting rod 7 is coaxially coupled with the cams 50 of the pair of tilting mechanisms 6, and thus can rotate together with the cam 50 (refer to Figure 6 ).

[0044] As shown in (a) of Figures 6 to 7 and Figure 8 , in the inserted state of the end 7b of the connecting rod 7 and the connecting rod insertion hole 52a of the cam 50, a gap 9 is provided between the inner peripheral surface 52a1 of the connecting rod insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the end 7b of the connecting rod 7 in the same manner as in the prior art. Thereby, it is possible to absorb the adverse effects on the operability and locking load of the tilting mechanism 6 caused by dimensional deviations or distortions of the frame assembly.

[0045] As shown in (a) and (c) of Figure 5 , the fitting portion 7c of the connecting rod 7 is a portion that fits with the resin bushings 8 disposed on both sides of the central portion 7a near the end 7b (that is, at a position adjacent to the central portion 7a side of the end 7b or at a position between the central portion 7a and the end 7b). The fitting portion 7c has a tapered portion 7d having a tapered shape that becomes narrower as it extends toward the end 7b of the connecting rod 7.

[0046] Specifically, the fitting portion 7c has: a circular cross-sectional portion 7h continuous with the central portion 7a (refer to Figure 7 and Figure 8 (e)); a substantially elliptical cross-sectional portion 7g continuous with the end 7b (refer to Figure 7 and Figure 8 (c)); a tapered portion 7d that continuously connects the circular cross-sectional portion 7h and the substantially elliptical cross-sectional portion 7g (refer to Figure 7 and Figure 8 (d)). In the substantially elliptical cross-sectional portion 7g, a recess 7e continuous from the end 7b is also formed (refer to Figure 5 (a), Figure 8 (a) to (b)).

[0047] The tapered portion 7d has a circular cross-section near the circular cross-sectional portion 7h, but has a cross-sectional shape that transitions to a substantially elliptical cross-section similar to that of the end 7b as it extends toward the end 7b.

[0048] The resin bushing 8 is a cylindrical body formed of a resin material and having a fitting hole 8e. Specifically, as shown in Figure 4 , it includes 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 state of being linearly arranged along the axial direction S of the connecting rod 7 (refer to Figure 3 ).

[0049] In order to prevent abnormal noise from occurring between the connecting rod 7 and the cam 50, the resin bushing 8 is mainly formed of a resin material such as plastic. As the material of the resin bushing 8, as long as it is an elastic material such as rubber (e.g., synthetic rubber) or elastomer, it can be substituted. The material of the resin bushing 8 is preferably a material having characteristics such as low contact resistance between the internal gear 30 and the skeleton 3a and wear resistance.

[0050] The resin bushing 8 has a fitting hole 8e that can be fitted with a fitting portion 7c near the end portion 7b of the connecting rod 7. The fitting hole 8e is formed so as to penetrate the main body portion 8a and the flange portion 8b along the axial direction.

[0051] Therefore, as shown in (c) to (e) of Figures 6 to 7 and Figure 8 , in a state where the fitting portion 7c of the connecting rod 7 is fitted into the fitting hole 8e of the resin bushing 8, the cylindrical main body portion 8a can support the connecting rod 7 in a state of extending along the axial direction S of the connecting rod 7 and abutting against the connecting rod 7 in the entire circumferential range.

[0052] The fitting hole 8e of the resin bushing 8 has a shape corresponding to the outer diameter of the fitting portion 7c of the connecting rod 7. Specifically, the fitting hole 8e has: a circular cross-sectional hole portion 8e1 corresponding to the circular cross-sectional portion 7h of the fitting portion 7c (refer to Figure 7 and Figure 8 's (e)); a tapered hole portion 8e2 corresponding to the tapered portion 7d (refer to Figure 7 and Figure 8 's (d)); a substantially elliptical cross-sectional hole portion 8e3 corresponding to the substantially elliptical cross-sectional portion 7g (refer to Figure 7 and Figure 8 's (c)).

[0053] The tapered hole portion 8e2 has a tapered shape that can be fitted with the tapered portion 7d having a tapered shape in the connecting rod 7. In addition, in Figure 7 and Figure 8 's (d), there is a small gap between the tapered portion 7d and the inner peripheral surface of the tapered hole portion 8e2, but this gap can also be dispensed with.

[0054] The flange portion 8b of the resin bushing 8 is a disk-shaped portion that protrudes radially outward from the end peripheral edge of the main body portion 8a (specifically, the end peripheral edge on the outer side in the axial direction S of Figure 3 ). In a state where the resin bushing 8 is fitted to the fitting portion 7c of the connecting rod 7, the flange portion 8b can abut against the skeleton 3a of the seat back 3 to which the internal gear 30 is fixed (specifically, the surface on the opposite side of the internal gear 30 in the skeleton 3a) along the axial direction S of the connecting rod 7 (refer to Figure 3 , Figures 6 to 7 ).

[0055] As Figure 4 , Figures 6 to 7 , and Figure 8 as shown in (b) of FIG., a pair of claw portions 8d project from the surface of the flange portion 8b on the side opposite to the main body portion 8a, and extend along the axial direction S of the link 7 so as to support the link 7 from both sides.

[0056] As Figure 8 shown in (b) of FIG., the facing portions 8d1 of the pair of claw portions 8d facing each other have a shape (e.g., concavo-convex shape) capable of fitting with the substantially elliptical cross-sectional portion 7g of the fitting portion 7c of the link 7. Specifically, the facing portions 8d1 have a convex shape capable of fitting with a pair of recesses 7e formed on the substantially elliptical cross-sectional portion 7g of the fitting portion 7c.

[0057] In addition, as Figures 6 to 7 shown, the surfaces on the side opposite to the link 7 of the pair of claw portions 8d, i.e., the outer peripheral surfaces 8d2, have a shape capable of fitting with the bushing insertion holes 35 of the internal gear 30. Specifically, as Figure 8 shown in (b) of FIG., the outer peripheral surfaces 8d2 of the pair of claw portions 8d are curved in an arc shape, and have a shape that allows the pair of claw portions 8d to fit with the bushing insertion holes 35 having a circular cross-section (see Figure 9 ). That is, in a state where the pair of claw portions 8d are fitted in the bushing insertion holes 35, the arc-shaped outer peripheral surfaces 8d2 are in surface contact with the inner peripheral surfaces of the bushing insertion holes 35 having a circular cross-section, and thus a stable fitting state can be obtained.

[0058] In the tilting device 5 having the above-described structure, as Figures 2 to 3 , Figures 6 to 7 shown, when the end portion 7b of the link 7 is coaxially coupled to the tilting mechanism 6, first, the resin bushing 8 is fitted in the fitting portion 7c near the end portion 7b of the link 7. At this time, the end portion 7b of the link 7 is in a state of protruding outside the resin bushing 8.

[0059] Next, the end portion 7b of the link 7 and the pair of claw portions 8d of the resin bushing 8 are passed through the through holes 3b of the frame 3a of the seat back 3, and inserted into the bushing insertion holes 35 of the internal gear 30. Specifically, the pair of claw portions 8d are fitted into the bushing insertion holes 35, and the outer peripheral surfaces 8d2 of the pair of claw portions 8d are brought into contact with the inner peripheral surface and the edge of the bushing insertion holes 35. At this time, the resin bushing 8 is positioned relative to the cam 50 in a state where a gap 9 is formed between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the end portion 7b of the link 7, in a state of being inserted (specifically, fitted) into the bushing insertion holes 35 of the internal gear 30. Thus, the end portion 7b of the link 7 can be fitted into the bushing insertion holes 35 of the internal gear 30 with the gap 9. In addition, in a state where the resin bushing 8 is inserted (fitted) into the bushing insertion holes 35, it is sufficient that at least a part of the outer peripheral surface 8d2 of the pair of claw portions 8d is in contact with the inner peripheral surface of the bushing insertion holes 35, and it is not necessary to be in contact with the edge of the inner peripheral surface of the bushing insertion holes 35.

[0060] In the above structure, in a state where the pair of claw portions 8d are inserted into the bushing insertion holes 35 of the internal gear 30, the resin bushing 8 can rotate together with the link 7 and the cam 50.

[0061] (Detailed structure of the tilting mechanism 6)

[0062] Hereinafter, the detailed structure of the tilting mechanism 6 of the present embodiment will be described. As described above, in the present invention, the tilting mechanism 6 only needs to include at least the internal gear 30 and the cam 50, and other structural elements can be appropriately changed.

[0063] The tilting mechanism 6 is installed between the frame 2a of the seat cushion 2 and the frame 3a of the seat back 3 described above (see Figures 2 to 3 ).

[0064] As Figure 9 shown, the tilting mechanism 6 includes a guide bracket 20, an internal gear 30, a disc spring 40, a cam 50, four locking plates 60A to 60D, and a mounting ring 70.

[0065] As Figure 3 and Figure 6 shown, the guide bracket 20 is fixed near the rear of the frame 2a (specifically, the side frame) of the seat cushion 2. The internal gear 30 is fixed near the lower part of the frame 3a (specifically, the side frame) of the seat back 3.

[0066] In addition, when the frame 2a of the seat cushion 2 shown in Figure 3 is arranged inside the frame 3a of the seat back 3, it is sufficient to fix the internal gear 30 to the frame 2a of the seat cushion 2 and fix the guide bracket 20 to the frame 3a of the seat back 3.

[0067] As shown Figure 9 in the figure, the guide bracket 20 is formed in a disc shape, and a configuration hole 22 for arranging the disc spring 40 is formed through the center thereof. The outer end portion 41 of the disc spring 40 is engaged with an engagement groove 22a provided on the inner peripheral surface of the configuration hole 22.

[0068] The internal gear 30 is formed in a circular shape when viewed from above and is formed in a substantially concave shape in cross section. Internal teeth 32 are formed on the inner peripheral surface of the concave portion 31, and the concave portion 31 is arranged facing the inner side surface 20a of the guide bracket 20 (refer to Figure 6 ). The internal gear 30 is connected to the frame 3a of the seat back 3, for example, by a connecting projection 34 that protrudes to the right rear side of the paper surface of Figure 9 .

[0069] The guide bracket 20 and the internal gear 30 are positioned by the mounting ring 70 in such a manner that the guide bracket 20 faces the concave portion 31 of the internal gear 30 and the end surface 31a1 of the peripheral wall 31a of the concave portion 31 is butt-jointed with the facing surface of the guide bracket 20.

[0070] The mounting ring 70 has: a ring-shaped bottom plate portion 71, which is formed in a substantially circular ring shape with a specified width; and a ring-shaped side plate portion 72, which extends from the outer peripheral edge side of the ring-shaped bottom plate portion 71 in a substantially orthogonal direction, 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 in which the radial cross-sectional shape formed by the combination of the ring-shaped bottom plate portion 71 and the ring-shaped side plate portion 72 is substantially L-shaped.

[0071] In the present embodiment, the mounting ring 70 is covered in the following manner: in a state where the guide bracket 20 faces the concave portion 31 of the internal gear 30 and a locking mechanism including the disc spring 40, the cam 50, and the locking plates 60A to 60D is accommodated in the internal space thereof, the edge 72a of the ring-shaped side plate portion 72 extends beyond the outer peripheral surface 31a2 of the peripheral wall 31a of the internal gear 30 and reaches the outer peripheral surface 21b of the guide bracket 20 located on the side beyond this outer peripheral surface 31a2 ( Figure 9 the left front side of the paper surface of). If assembled in this way, the central protruding portion of the internal gear 30 is exposed outside relative to the inner peripheral circle of the ring-shaped bottom plate portion 71 ( Figure 9in the right depth direction of the paper surface). After the mounting ring 70 is assembled in this way, the portion of the annular side plate portion 72 thereof facing the outer peripheral surface 21b of the guide bracket 20 is welded and fixed to the outer peripheral surface 21b. Therefore, in a state where the guide bracket 20 is fixed to the frame 2a of the seat cushion 2, for example, and the connecting projection 34 of the internal gear 30 is fixed to the frame 3a of the seat back 3, for example, if the seat back 3 rotates relative to the seat cushion 2, 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.

[0072] The cam 50 is a member that moves the locking plates 60A to 60D back and forth in the radial direction of the cam 50. The cam 50 is provided with four engaging protrusions 51, 51 corresponding to the four arranged locking plates 60A to 60D and extending in a substantially arc shape and angularly at equal intervals in the circumferential direction. In addition, in the main body portion 52 of the cam 50 other than the engaging protrusions 51, 51, stepped portions 52b, 52b are formed at four positions, which bulge in such a way that the outer diameter becomes larger at positions separated from the bases of the respective engaging protrusions 51, 51 by a specified angle. The cam 50 is integrally fixed to one surface of the partition plate 55. A link insertion hole 52a through which the end portion 7b of the link 7 passes is formed through the center of the cam 50. If the link 7 is rotated in either the forward or reverse direction using an operating member (not shown) mounted on the end portion 7b of the link 7, etc., the cam 50 will rotate in the same direction following this operation.

[0073] The cam 50 is provided with a first shaft portion 53 that protrudes from the periphery of the link insertion hole 52a toward the guide bracket 20 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 disc spring 40, and an engaging groove 53a formed by cutting from the outer peripheral surface toward the center direction is formed on the first shaft portion 53. The disc spring 40 is disposed on the outer periphery of the first shaft portion 53, and its inner end portion 42 is engaged with the engaging groove 53a of the first shaft portion 53 (refer to Figure 8 (a)), and is disposed in the fitting hole 22 of the guide bracket 20 together with the first shaft portion 53. Since the outer end portion 41 of the disc spring 40 is engaged with the engaging groove 22a formed on the inner peripheral surface of the fitting hole 22 of the guide bracket 20, a force in one rotational direction is applied to the cam 50.

[0074] A second shaft portion 36 protruding toward the cam 50 is provided at the center of the internal gear 30. The second shaft portion 36 is inserted into a bearing hole (not shown) formed on the cam 50 to rotatably support the cam 50.

[0075] In the present embodiment, four locking plates 60A to 60D are used. The four locking plates 60A to 60D are arranged at positions corresponding to four angular engaging protrusions 51, 51 formed on the cam 50. The locking plates 60A to 60D can slide in the radial direction of the guide bracket 20 along a radially extending guide groove portion (not shown) formed in the guide bracket 20.

[0076] In the locking plates 60A to 60D and the cam 50, based on the rotation of the cam 50 in one direction due to the elasticity of the disc spring 40, a force acting outward in the radial direction is applied to the locking plates 60A to 60D. Based on the rotation of the cam 50 in the opposite direction due to the operation of the link 7, the locking plates 60A to 60D are displaced toward the center direction. Each of the locking plates 60A to 60D has a substantially rectangular shape in plan view. In addition, engaged grooves 61, 61 that are formed by substantially arcuately cutting away from the inner peripheral surface are provided in each of the locking plates 60A to 60D. When the cam 50 rotates in the clockwise direction, the engaging protrusions 51, 51 engage with the engaged grooves 61, 61, thereby pulling the locking plates 60A to 60D toward the center direction of the cam 50. When the cam 50 is urged by the disc spring 40 to rotate in the counterclockwise direction, the engaging protrusions 51, 51 and the stepped portions 52b, 52b press the locking plates 60A to 60D toward the outside in the radial direction of the cam 50. External teeth 63, 63 are formed on the outer peripheral surfaces of the locking plates 60A to 60D, and when they are pressed toward the outside in the radial direction, 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. Thus, the seat back 3 can be fixed at an arbitrary tilt angle.

[0077] (Features of the present embodiment)

[0078] (1) The tilting device 5 of the present embodiment can Figure 1 hold the seat back 3 shown relative to the seat cushion 2 so as to be tiltable, and fix it at an arbitrary tilt angle.

[0079] As Figures 1 to 6 shown, the tilting device 5 includes: a pair of tilting mechanisms 6, which are respectively arranged on both sides in the width direction Y of the seat 1, and each have an internal gear 30 and a cam 50. The internal gear 30 is fixed to the skeleton of one of the seat cushion 2 and the seat back 3 (in the present embodiment, the skeleton 3a of the seat back 3), and the cam 50 is arranged side by side with respect to the internal gear 30 in its thickness direction (that is, the above-mentioned width direction Y); a link 7, which extends along the width direction Y of the seat 1, and is coaxially coupled to the cams 50 of the pair of tilting mechanisms 6 respectively, and rotates together with the cam 50.

[0080] The tilting device 5 of the present embodiment further includes a resin bushing 8, which is a cylindrical body having a fitting hole 8e and is fitted into a fitting portion 7c near the end portion 7b of the link 7.

[0081] As Figures 6 to 7 shown, the cam 50 has a link insertion hole 52a into which the end portion 7b of the link 7 can be inserted. The internal gear 30 has a bushing insertion hole 35 at the center position of the internal gear 30 into which the resin bushing 8 can be inserted.

[0082] As Figures 6 to 7 and Figure 8 (a) of FIG. shows, the fitting portion 7c near the end portion 7b of the link 7 is fitted into the fitting hole 8e of the resin bushing 8, and the end portion 7b of the link 7 protrudes outside the resin bushing 8. The resin bushing 8 is inserted into the bushing insertion hole 35 in a state of abutting against the inner peripheral surface of the bushing insertion hole 35 of the internal gear 30 so as to position the link 7 relative to the cam 50 in a state where a gap 9 is formed between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the link 7.

[0083] According to this structure, the resin bushing 8 is inserted into the bushing insertion hole 35 in a state of abutting against the inner peripheral surface of the bushing insertion hole 35 of the internal gear 30 so as to position the link 7 relative to the cam 50 in a state where a gap 9 is formed between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the link 7. Thus, the resin bushing 8 can restrict the relative movement of the link 7 relative to the cam 50 in the radial direction of the cam 50 and can prevent interference noise from occurring between the cam 50 and the link 7. As a result, it is possible to effectively prevent abnormal noise while allowing the gap 9 between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the link 7.

[0084] In addition, since the resin bushing 8 is not arranged between the cam 50 and the link 7 to position the two relatively, but positions the link 7 in a state of being inserted into the bushing insertion hole 35 of the internal gear 30, it is not restricted by the dimensional limitation of the gap 9 between the cam 50 and the link 7 and the resulting rigidity limitation. Therefore, compared with an elastic ring as in the prior art (the structure described in the above-mentioned Patent Document 1), the resin bushing 8 can be set to have wear-resistant dimensions and rigidity.

[0085] (2) In the tilting device 5 of the present embodiment, the fitting hole 8e of the resin bushing 8 has a shape corresponding to the outer diameter of the fitting portion 7c of the link 7. That is, as Figure 7 and Figure 8 (c) to (e) of FIG. show, the fitting hole 8e has a circular cross-sectional hole portion 8e1, a tapered hole portion 8e2, and a substantially elliptical cross-sectional hole portion 8e3.

[0086] According to this structure, by simply fitting the fitting portion 7c near the end portion 7b of the connecting rod 7 into the fitting hole 8e of the resin bushing 8, the installation operation of the resin bushing 8 to the fitting portion 7c near the end portion 7b of the connecting rod 7 can be completed, so the working efficiency is good. Moreover, based on the simple structure formed by the combination of the connecting rod 7 and the resin bushing 8, it is possible to prevent the resin bushing 8 from axially coming off the internal gear 30, and it is also possible to prevent the resin bushing 8 from coming off the connecting rod 7.

[0087] (3) In the tilting device 5 of the present embodiment, as Figures 3 to 4 、 Figures 6 to 7 shown, the resin bushing 8 has a flange portion 8b that abuts against the skeleton 3a of the seat back 3 to which the internal gear 30 is fixed from the axial direction S of the connecting rod 7.

[0088] According to this structure, by the flange portion 8b of the resin bushing 8 abutting against the skeleton 3a of the seat back 3 from the axial direction S of the connecting rod 7, the movement of the resin bushing 8 in the axial direction S can be restricted.

[0089] In addition, by the flange portion 8b covering the gap between the inner peripheral surface of the through hole 3b of the resin bushing 8 and the skeleton 3a, it is possible to prevent foreign matter from invading the tilting mechanism 6 through the through hole 3b.

[0090] (4) In the tilting device 5 of the present embodiment, the resin bushing 8 has a cylindrical main body portion 8a that extends along the axial direction S of the connecting rod 7 and supports the connecting rod 7 in a state of abutting against the connecting rod 7 over the entire circumference.

[0091] According to this structure, since the cylindrical main body portion 8a of the resin bushing 8 supports the connecting rod 7 in a state of abutting against the connecting rod 7 over the entire circumference, it is possible to further restrict the relative movement of the connecting rod 7 in the radial direction with respect to the cam 50, and improve the effect of preventing abnormal noise from occurring.

[0092] (5) In the tilting device 5 of the present embodiment, as Figures 5 to 7 shown, the fitting portion 7c of the connecting rod 7 has a tapered portion 7d with a tapered shape that becomes narrower as it extends toward the end portion 7b of the connecting rod 7. As Figure 7 and Figure 8 (d) of shown, the fitting hole 8e of the resin bushing 8 has a tapered hole portion 8e2 with a tapered shape that can be fitted with the tapered portion 7d having a tapered shape in the connecting rod 7.

[0093] According to this structure, the tapered portion 7d with a tapered shape formed on the fitting portion 7c near the end portion 7b of the connecting rod 7 is fitted into the tapered hole portion 8e2 with a tapered shape of the fitting hole 8e of the resin bushing 8, restricting the axial movement of the resin bushing 8. Thus, without increasing the number of parts, it is possible to prevent the resin bushing 8 from axially falling off the internal gear 30 and also prevent the resin bushing 8 from falling off the connecting rod 7 by a simple structure formed by the combination of the connecting rod 7 and the resin bushing 8.

[0094] (6) In the tilting device 5 of the present embodiment, as shown in (b) of Figure 4 、 Figures 6 to 7 and Figure 8 , the resin bushing 8 has a pair of claw portions 8d that extend along the axial direction S of the connecting rod 7 and support the connecting rod 7 from both sides.

[0095] According to this structure, since the pair of claw portions 8d of the resin bushing 8 support the connecting rod 7 from both sides, it is possible to further restrict the relative movement of the connecting rod 7 with respect to the cam 50 in the radial direction, improving the effect of preventing abnormal noise from occurring.

[0096] (7) In the tilting device 5 of the present embodiment, as shown in (b) of Figure 8 , the facing portions 8d1 of the pair of claw portions 8d facing each other have a shape that can be fitted into the fitting portion 7c of the connecting rod 7. That is, the facing portion 8d1 has a convex shape that can be fitted into the concave portion 7e of the substantially elliptical cross-sectional portion 7g of the fitting portion 7c.

[0097] According to this structure, based on the fitting of the facing portions 8d1 of the pair of claw portions 8d of the resin bushing 8 into the fitting portion 7c near the end portion 7b of the connecting rod 7, it is possible to further restrict the relative movement of the connecting rod 7 with respect to the cam 50 in the radial direction, improving the effect of preventing abnormal noise from occurring.

[0098] (8) In the tilting device 5 of the present embodiment, as shown in (b) of Figures 6 to 7 and Figure 8 , the pair of claw portions 8d each have a surface on the opposite side with respect to the connecting rod 7, that is, an outer peripheral surface 8d2. The outer peripheral surfaces 8d2 of the pair of claw portions 8d each have a shape that can be fitted into the bushing insertion hole 35 of the internal gear 30. That is, the outer peripheral surfaces 8d2 of the pair of claw portions 8d each have an arc shape that can be fitted into the circular cross-sectional bushing insertion hole 35.

[0099] According to this structure, a pair of claw portions 8d of the resin bushing 8 are engaged with the bushing insertion hole 35 of the internal gear 30, which can improve the effect of supporting the link 7 from both sides by the pair of claw portions 8d and can further restrict the relative movement of the link 7 relative to the cam 50 in the radial direction. In addition, by simply engaging the pair of claw portions 8d with the bushing insertion hole 35, the positioning of the resin bushing 8 and the link 7 can be easily performed, improving the assembly workability of the tilting device 5.

[0100] (9) As Figures 1 to 7 shown, the seat 1 of the present embodiment includes: a seat cushion 2; a seat backrest 3, which is disposed at the rear of the seat cushion 2 and can tilt along the front-rear direction X of the seat 1; and a tilting device 5 having the above structure for fixing the seat backrest 3 at an arbitrary tilting angle.

[0101] The tilting device 5 included in the above seat 1 has the following configuration: the resin bushing 8 is inserted into the bushing insertion hole 35 in a state of abutting against the inner peripheral surface of the bushing insertion hole 35 of the internal gear 30, so as to position the link 7 in a state where a gap 9 is formed between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the link 7. Thus, the resin bushing 8 restricts the relative movement of the link 7 relative to the cam 50 in the radial direction of the cam 50. As a result, rattling can be effectively prevented while allowing the gap 9 between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the link 7.

[0102] (Modification example)

[0103] As Figure 4 and Figure 7 shown, the main body portion 8a of the resin bushing 8 in the above embodiment has a length that can be integrally engaged with the entire engaging portion 7c of the link 7, that is, a length that can be engaged not only with the substantially elliptical cross-sectional portion 7g but also with the circular cross-sectional portion 7h and the tapered portion 7d. However, in the present invention, there is no particular limitation on the length of the main body portion 8a of the resin bushing 8.

[0104] Therefore, as Figures 10 to 12 shown, as a modification example of the present invention, the length of the main body portion 8a of the resin bushing 8 can also be changed to a length that can only be engaged with the substantially elliptical cross-sectional portion 7g.

[0105] In Figures 10 to 12 the modification example, by shortening the main body portion 8a, miniaturization of the resin bushing 8 can be achieved.

[0106] Even in the case of Figures 10 to 12 this modification example, through the substantially elliptical cross-sectional portion 7g of the link 7 (that is, having Figure 8(from the concave portion 7e of (b) to (c)) and the fitting hole 8e of the main body portion 8a of the resin bushing 8 (specifically, Figure 8 such as the substantially elliptical cross-sectional hole portion 8e3 as in (c) thereof) and the opposing portions 8d1 of the convex shapes of the pair of claw portions 8d are fitted, and the relative movement of the link 7 with respect to the cam 50 in the radial direction can be restricted, improving the effect of preventing abnormal noise from occurring.

[0107] In addition, in this modification, as Figure 12 shown, the resin bushing 8 is not fitted to the tapered portion 7d of the link 7. However, since the tapered portion 7d is disposed near the mounting position of the resin bushing 8, it is possible to prevent the resin bushing 8 from shifting and disengaging in the axial direction (specifically, preventing disengagement from the through hole 3b of the frame 3a and the bushing insertion hole 35 of the internal gear 30).

[0108] As Figure 10 and Figure 11 shown in (c) and (e) thereof, the resin bushing 8 of this modification has a pair of opposing flat surfaces on the outer peripheral surface of the main body portion 8a. Therefore, the rotation angles of the resin bushing 8 and the link 7 can be easily adjusted using a tool.

[0109] In addition, as Figures 13 to 15 shown, as another modification of the present invention, the resin bushing 8 may also be a structure that omits the above-described main body portion 8a and has an engaging portion 8f that can engage with the frame 3a.

[0110] The engaging portion 8f has a structure that can engage with the frame 3a of the seat back 3 to which the internal gear 30 is fixed, and is, for example, composed of claws that can engage with the edge of the through hole 3b of the frame 3a. The engaging portion 8f projects outward in the radial direction of the resin bushing 8 from the respective outer peripheral surfaces 8d2 of the pair of claw portions 8d.

[0111] In this Figures 13 to 15 modification, the engaging portion 8f of the resin bushing 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). Thereby, the resin bushing 8 is prevented from falling off from the frame 3a. Moreover, since the resin bushing 8 is reliably fixed by both the frame 3a and the internal gear 30, the resin bushing 8 can reliably restrict the relative movement of the link 7 with respect to the cam 50 in the radial direction of the cam 50, improving the effect of preventing abnormal noise from occurring.

[0112] In addition, when the internal gear 30 is fixed to the frame 2a of the seat cushion 2, the engaging portion 8f only needs to engage with the frame 2a of the seat cushion 2.

[0113] In addition, in Figures 13 to 15In the illustrated modified example, each of the pair of claw portions 8d of the resin bushing 8 has an outer peripheral surface 8d2 which is a surface located on the opposite side with respect to the link 7, that is, an outer peripheral surface. The outer peripheral surface 8d2 has a tapered shape that inclines in a direction approaching the center of the bushing insertion hole 35 as it extends toward the distal end of the claw portion 8d, and abuts against the edge of the bushing insertion hole 35 of the internal gear 30. Further, the edge is included in the inner peripheral surface of the bushing insertion hole 35. In this structure, the pair of claw portions 8d of the resin bushing 8 are inserted into the bushing insertion hole 35 in a state of abutting against the edge of the bushing insertion hole 35, whereby the link 7 can be positioned relative to the cam 50 in a state where a gap 9 is formed between the inner peripheral surface 52a1 of the link insertion hole 52a of the cam 50 and the outer peripheral surface 7f of the link 7.

[0114] According to this structure, based on the fact that the tapered outer peripheral surface 8d2 of the pair of claw portions 8d of the resin bushing 8 abuts against the edge of the bushing insertion hole 35 of the internal gear 30, the abutting state between the resin bushing 8 and the internal gear 30 can be reliably maintained. Further, based on the above structure, dimensional deviations in either one or both of the bushing insertion hole 35 and the claw portion 8d can be absorbed.

[0115] In the above Figures 13 to 15 illustrated modified example, miniaturization of the resin bushing 8 can also be achieved by omitting the main body portion 8a.

[0116] Moreover, as Figure 15 illustrated, although the resin bushing 8 is not fitted to the tapered portion 7d of the link 7, based on the fact that the tapered portion 7d is arranged near the mounting position of the resin bushing 8, it is possible to prevent the resin bushing 8 from shifting and coming off in the axial direction (specifically, to prevent coming off from the through hole 3b of the frame 3a and the bushing insertion hole 35 of the internal gear 30).

[0117] <Summary of the Embodiment>

[0118] The above-described embodiment is summarized as follows.

[0119] The tilting device of this embodiment includes: a pair of tilting mechanisms, which are respectively arranged on both sides in the width direction of the seat, and each has an internal gear and a cam. The internal gear is fixed to the skeleton of one of the seat cushion and the seat back, and the cams are arranged side by side in the thickness direction with respect to the internal gear; and a connecting rod, which extends along the width direction of the seat, is coaxially coupled to the cams of the pair of tilting mechanisms respectively, and rotates together with the cams; this tilting device tiltably holds and fixes the seat back relative to the seat cushion at an arbitrary tilting angle, and further includes: a resin bushing, which is a cylindrical body having a fitting hole and is fitted into a fitting portion formed near the end of the connecting rod; wherein, the cam has a connecting rod insertion hole into which the end of the connecting rod can be inserted, the internal gear has a bushing insertion hole at the central position of the internal gear into which the resin bushing can be inserted, the fitting portion near the end of the connecting rod is fitted into the fitting hole of the resin bushing, the end of the connecting rod protrudes outside the resin bushing, and the resin bushing is inserted into the bushing insertion hole in a state of abutting against the inner peripheral surface of the bushing insertion hole of the internal gear, so as to position the connecting rod relative to the cam in a state where there is a gap between the inner peripheral surface of the connecting rod insertion hole of the cam and the outer peripheral surface of the connecting rod. The edge portion of the above-mentioned bushing insertion hole is also included in the inner peripheral surface of the bushing insertion hole.

[0120] According to this structure, the resin bushing is inserted into the bushing insertion hole of the internal gear in a state of abutting against the inner peripheral surface of the bushing insertion hole, so as to position the connecting rod relative to the cam in a state where there is a gap between the inner peripheral surface of the connecting rod insertion hole of the cam and the outer peripheral surface of the connecting rod. Thereby, the resin bushing can limit the relative movement of the connecting rod relative to the cam in the radial direction of the cam, and can prevent interference noise from occurring between the cam and the connecting rod. As a result, it is possible to effectively prevent abnormal noise while allowing the gap between the inner peripheral surface of the connecting rod insertion hole of the cam and the outer peripheral surface of the connecting rod.

[0121] In the above-mentioned tilting device, it is preferable that the fitting hole of the resin bushing has a shape corresponding to the outer diameter of the fitting portion of the connecting rod.

[0122] According to this structure, only by inserting the fitting portion near the end of the connecting rod into the fitting hole of the resin bushing, the installation operation of the resin bushing on the connecting rod can be completed, so the operation efficiency is good. Moreover, it is possible to prevent the resin bushing from falling off the internal gear along the axial direction and also prevent the resin bushing from falling off the connecting rod through a simple structure composed of the connecting rod and the resin bushing.

[0123] In the above-mentioned tilting device, it is preferable that the resin bushing has a flange portion, and the flange portion abuts against the skeleton of the seat cushion and the skeleton of the seat back on the axial side of the connecting rod, where the internal gear is fixed.

[0124] According to this structure, the flange portion of the resin bushing abuts against the skeleton of the seat cushion or the seat back from the axial direction of the link, and the movement of the resin bushing in the axial direction can be restricted.

[0125] In the above-mentioned tilting device, it is preferable that the resin bushing has a cylindrical main body portion that supports the link in a state of extending along the axial direction of the link and abutting against the link over the entire circumference.

[0126] According to this structure, since the cylindrical main body portion of the resin bushing supports the link in a state of abutting against the link over the entire circumference, the relative movement of the link with respect to the cam in the radial direction can be further restricted, and the effect of preventing abnormal noise from occurring can be improved.

[0127] In the above-mentioned tilting device, it is preferable that the fitting portion of the link has a tapered portion that becomes narrower as it extends toward the end of the link, and the fitting hole of the resin bushing has a tapered hole portion that can be fitted with the tapered portion in the link.

[0128] According to this structure, the tapered portion formed on the fitting portion near the end of the link is fitted with the tapered hole portion of the fitting hole of the resin bushing, restricting the axial movement of the resin bushing. Thus, without increasing the number of parts, it is possible to prevent the resin bushing from falling off the internal gear in the axial direction and also prevent the resin bushing from falling off the link by a simple structure composed of the link and the resin bushing.

[0129] In the above-mentioned tilting device, it is preferable that the resin bushing has a pair of claw portions that extend along the axial direction of the link and support the link from both sides.

[0130] According to this structure, since the pair of claw portions of the resin bushing support the link from both sides, the relative movement of the link with respect to the cam in the radial direction can be further restricted, and the effect of preventing abnormal noise from occurring can be improved.

[0131] In the above-mentioned tilting device, it is preferable that the portions facing each other in the pair of claw portions have a shape that can be fitted with the fitting portion of the link.

[0132] According to this structure, based on the fitting of the portions facing each other in the pair of claw portions of the resin bushing with the fitting portion near the end of the link, the relative movement of the link with respect to the cam in the radial direction can be further restricted, and the effect of preventing abnormal noise from occurring can be improved.

[0133] In the above-described tilting device, it is preferable that each of the pair of claw portions has a surface located on the opposite side with respect to the link, that is, an outer peripheral surface, and the outer peripheral surface has a shape that can be fitted into the bushing insertion hole of the internal gear.

[0134] According to this structure, the pair of claw portions of the resin bushing are fitted into the bushing insertion holes of the internal gear, which can improve the effect of supporting the link from both sides by the pair of claw portions, and can further restrict the relative movement of the link with respect to the cam in the radial direction. In addition, by simply fitting the pair of claw portions into the bushing insertion holes, the positioning of the resin bushing and the link can be easily performed, improving the assembly workability of the tilting device.

[0135] In the above-described tilting device, it is preferable that each of the pair of claw portions has a surface located on the opposite side with respect to the link, that is, an outer peripheral surface, and the outer peripheral surface has a tapered shape that inclines in a direction approaching the center of the bushing insertion hole as it extends toward the distal end of the claw portion, and abuts against the edge of the bushing insertion hole of the internal gear.

[0136] According to this structure, the tapered outer peripheral surface of the pair of claw portions of the resin bushing abuts against the edge of the bushing insertion hole of the internal gear, which can reliably maintain the abutting state between the resin bushing and the internal gear. In addition, based on the above structure, dimensional deviations in either or both of the bushing insertion hole and the claw portion can be absorbed.

[0137] In the above-described tilting device, it is preferable that the resin bushing further has an engaging portion that can engage with the frame of the seat cushion and the frame of the seat backrest in which the internal gear is fixed.

[0138] According to this structure, by engaging the engaging portion of the resin bushing with the frame of the seat cushion and the frame of the seat backrest in which the internal gear is fixed, the resin bushing is prevented from falling off the frame. Moreover, since the resin bushing is reliably fixed based on both the frame and the internal gear, the resin bushing can reliably restrict the relative movement of the link with respect to the cam in the radial direction of the cam, improving the effect of preventing abnormal noise from occurring.

[0139] The seat of the present embodiment includes: a seat cushion; a seat backrest disposed at the rear of the seat cushion and capable of tilting in the seat front-rear direction; and the above-described tilting device that fixes the seat backrest at an arbitrary tilting angle.

[0140] The tilting device of the above-described seat has the following configuration: A resin bushing is inserted into the bushing insertion hole of the internal gear in a state of abutting against the inner peripheral surface of the bushing insertion hole, so that the link is positioned in a state where a gap is formed between the inner peripheral surface of the link insertion hole of the cam and the outer peripheral surface of the link. Thus, the resin bushing restricts the relative movement of the link with respect to the cam in the radial direction of the cam. As a result, it is possible to effectively prevent abnormal noise while allowing a gap between the inner peripheral surface of the link insertion hole of the cam and the outer peripheral surface of the link.

[0141] According to the tilting device and the seat of the present embodiment, it is possible to effectively prevent abnormal noise while allowing a gap between the cam and the link.

Claims

1. An inclination device, characterized in that Comprising: A pair of tilting mechanisms, respectively arranged at positions on both sides in the width direction of the seat, and respectively having an internal gear and a cam, the internal gear being fixed to a skeleton of either the seat cushion or the seat back, and the cam being arranged side by side with respect to the internal gear in its thickness direction; and, A connecting rod, extending along the width direction of the seat, and coaxially coupled to the cams of the pair of tilting mechanisms respectively, and rotating together with the cams; This tilting device tiltably holds and fixes the seat back relative to the seat cushion at an arbitrary tilting angle, and further includes: A resin bushing, which is a cylindrical body having a fitting hole, and is fitted into a fitting portion formed near the end of the connecting rod; wherein, The cam has a connecting rod insertion hole into which the end of the connecting rod can be inserted, The internal gear has a bushing insertion hole at the center position of the internal gear into which the resin bushing can be inserted, The fitting portion near the end of the connecting rod is fitted with the fitting hole of the resin bushing, and the end of the connecting rod protrudes outside the resin bushing, The resin bushing is inserted into the bushing insertion hole of the internal gear in a state of abutting against the inner peripheral surface of the bushing insertion hole, so as to position the connecting rod relative to the cam in a state where a gap is formed between the inner peripheral surface of the connecting rod insertion hole of the cam and the outer peripheral surface of the connecting rod.

2. The tilting device according to claim 1, wherein: The fitting hole of the resin bushing has a shape corresponding to the outer diameter of the fitting portion of the connecting rod.

3. The tilting device according to claim 1 or 2, wherein: The resin bushing has a flange portion, and this flange portion abuts against the skeleton of the seat cushion and the skeleton of the seat back that fixes the internal gear from the axial direction of the connecting rod.

4. The tilting device according to claim 1 or 2, wherein: The resin bushing has a cylindrical main body portion, and this main body portion supports the connecting rod in a state of extending along the axial direction of the connecting rod and abutting against the connecting rod in the entire circumferential range.

5. The tilting device according to claim 1 or 2, wherein: The fitting portion of the connecting rod has a tapered portion that becomes narrower as it extends toward the end of the connecting rod, The fitting hole of the resin bushing has a tapered hole portion that can be fitted with the tapered portion in the connecting rod.

6. The tilting device according to claim 1 or 2, wherein: The resin bushing has a pair of claw portions that extend along the axial direction of the connecting rod and support the connecting rod from both sides.

7. The tilting device according to claim 6, wherein: The portions facing each other in the pair of claw portions have a shape that can be fitted with the fitting portion of the connecting rod.

8. The tilting device according to claim 6, wherein: Each of the pair of claw portions has a surface on the opposite side with respect to the connecting rod, that is, an outer peripheral surface, The outer peripheral surface has a shape that can be fitted with the bushing insertion hole of the internal gear.

9. The tilting device according to claim 6, wherein: Each of the pair of claw portions has a surface, i.e., an outer peripheral surface, located on the opposite side with respect to the link. The outer peripheral surface has a tapered shape that inclines in a direction approaching the center of the bushing insertion hole as it extends toward the distal end of the claw portion, and abuts against the edge of the bushing insertion hole of the internal gear.

10. The tilting device according to claim 1 or 2, wherein: The resin bushing further has an engaging portion that can engage with the skeleton of the seat cushion and the skeleton of the seat backrest in which the internal gear is fixed.

11. A seat, characterized in that Comprising: A seat cushion; A seat backrest, disposed at the rear of the seat cushion and capable of tilting in the front-rear direction of the seat; And, The tilting device according to claim 1, which fixes the seat backrest at an arbitrary tilting angle.

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