Reclining device and seat

Abstract

To provide a reclining device for suppressing rattling of a lock gear in a locked state.SOLUTION: A reclining mechanism 6 includes: four lock gears 60A-60D to be engaged with internal teeth 32 of an internal gear 30; and wedge members 80 for pressing the two main lock gears 60A, 60C among the four lock gears 60A-60D. Pressure faces 80c of the wedge members 80 and pressed faces 64 of the lock gears 60A. 60C have a curved face projectingly bending in mutually opposing directions. A perpendicular line L2 orthogonal at a contact point P1 with respect to a tangent line L1 to pass the contact point P1 where the pressure face 80c has contact with the pressed face 64 crosses a center line C extending in a radial direction through the center of a width in the circumferential direction of the main lock gears 60A, 60C. An intersection P2 of the perpendicular line L2 and the center line C exists in an area R on an inner side in the radial direction from radially outer side end parts 251 of guide wall parts 25A, 25B on both sides of the center line C.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventional vehicle seats include seats in which the seat back (backrest) is tiltable in the front-to-rear direction relative to the seat cushion (seat portion) and is equipped with a reclining device that fixes the seat back at any tilt angle.

[0003] For example, as shown in FIG. 9, the reclining device 101 described in Patent Document 1 includes an internal gear 102 having internal teeth 102a, a guide bracket 103 having two guide grooves 103a extending radially of the internal gear 102, two lock gears 104, a cam 105, and two wedge members 106.

[0004] As shown in FIG. 10, the guide groove 103a of the guide bracket 103 has a pair of guide walls 103b and 103c extending in the radial direction.

[0005] The lock gear 104 has external teeth 104a that can mesh with the internal teeth 102a of the internal gear 102, and a pressed surface 104b that is pressed by the wedge member 106. The lock gear 104 is disposed in the guide groove 103a of the guide bracket 103, and is movable radially along the pair of guide walls 103b, 103c.

[0006] The cam 105 is rotatable relative to the guide bracket 103 between a predetermined lock angle and a release angle, and by rotating from the release angle to the lock angle, the two lock gears 104 move radially from the release position to the engagement position.

[0007] The wedge member 106 has a substantially triangular shape. The wedge member 106 has a pressing surface 106a that abuts against the pressed surface 104b of the lock gear 104 and presses the lock gear 104. As shown in Fig. 10 , the wedge member 106 presses the lock gear 104 radially outward and circumferentially due to a pressing force F101 from the cam 105, and presses the lock gear 104 against a guide wall portion 103c that is located on the opposite side of the lock gear 104 from the wedge member 106. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4445549 Summary of the Invention [Problem to be solved by the invention]

[0009] 10, in the above configuration, pressing surface 106a of wedge member 106 and pressed surface 104b of lock gear 104 are both flat surfaces. Therefore, due to variations in the dimensional accuracy of wedge member 106 and lock gear 104, the position where pressing surface 106a and pressed surface 104b come into contact may vary, and the posture of lock gear 104 may become unstable. In particular, when the position where the pressing surface 106a and the pressed surface 104b come into contact is near the radially outer end of the pressing surface 106a, the force F102 with which the pressing surface 106a presses the pressed surface 104b is directed from the widthwise center of the lock gear 104 to the external tooth 104a that is closer to the wedge member 106, and is dispersed via the external tooth 104a to the internal tooth 102a of the internal gear 102. Therefore, the pressing force F102 cannot press the lock gear 104 against the guide wall portion 103c on the opposite side from the wedge member 106, making it difficult to eliminate rattle of the lock gear 104 in the locked state.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reclining device that can suppress rattle of a lock gear in a locked state. [Means for solving the problem]

[0011] The reclining device of the present invention includes a guide bracket fixed to one of a seat cushion and a seat back; an internal gear fixed to the other of the seat cushion and the seat back at a position opposite the guide bracket and rotatable relative to the guide bracket; a plurality of lock gears, each having external teeth that can mesh with internal teeth of the internal gear, that are arranged spaced apart circumferentially of the internal gear and that are movable in a radial direction of the guide bracket along the guide bracket between an engagement position where the external teeth and the internal teeth mesh with each other and a release position where the meshing is released; a cam that moves the plurality of lock gears radially from the release position to the engagement position; a lock spring that rotates the cam in a direction that moves the plurality of lock gears toward the engagement position; and a lock spring that rotates the cam in a radially outward direction by receiving a pressing force from the cam. and a wedge member pressing at least one lock gear, the guide bracket having multiple pairs of guide wall portions facing each other and guiding the multiple lock gears in the radial direction, the wedge member having a pressing surface that is interposed between the guide wall portion and the lock gear and presses the lock gear by receiving a pressing force of the cam, the lock gear having a pressed surface that is pressed by the pressing surface of the wedge member and extends in a direction inclined with respect to the radial direction, at least one of the pressing surface and the pressed surface has a shape in which at least a portion thereof protrudes in a direction opposing each other, a perpendicular line that is perpendicular to a tangent line passing through a contact point where the pressing surface and the pressed surface come into contact at the contact point intersects with a center line that passes through the center of the width of the lock gear in the circumferential direction and extends in the radial direction, and the intersection of the perpendicular line and the center line is present in a region that is radially inward of radially outer ends of the guide wall portions on both sides of the center line.

[0012] In this configuration, at least one of the pressing surface of the wedge member and the pressed surface of the lock gear has a shape in which at least a portion thereof protrudes in the direction opposite to the pressing surface. Furthermore, a perpendicular line perpendicular to a tangent line passing through the contact point where the pressing surface and the pressed surface come into contact intersects with a center line extending radially through the center of the circumferential width of the lock gear. The intersection of the perpendicular line and the center line is located in a region radially inward of the radially outer ends of the guide walls on both sides of the center line.

[0013] In this configuration, the contact point between the pressing surface of the wedge member and the pressed surface of the lock gear is reliably positioned at a radially inner position on the pressing surface. Therefore, when the pressing surface of the wedge member presses the pressed surface of the lock gear at the contact point with the pressed surface, the pressing force is directed in a direction along the perpendicular line, and at the intersection of the perpendicular line and the center line, the force is divided into circumferential and radial forces, thereby reliably pressing the lock gear in the circumferential direction against the guide wall portion on the opposite side of the wedge member. By specifying the load path in this way, the posture of the lock gear during movement is stabilized and rattling of the lock gear in the locked state can be suppressed.

[0014] In the above-described reclining device, it is preferable that the pressing surface and the pressed surface each have a portion that protrudes in a direction opposite to each other.

[0015] With this configuration, the contact point between the pressing surface of the wedge member and the pressed surface of the lock gear can be positioned further radially inward on the pressing surface, so that the lock gear can be firmly pressed against the guide wall portion on the opposite side of the center line from the wedge member, thereby more stabilizing the posture of the lock gear.

[0016] In the above-described reclining device, it is preferable that the pressed surface includes a curved surface that is curved so as to protrude in a direction facing the pressing surface.

[0017] In this configuration, the curved surface of the pressed surface can reliably contact the pressing surface of the wedge member, making it possible to more stabilize the posture of the lock gear. This allows for smooth engagement between the lock gear and the internal gear. It also ensures that the contact point between the pressing surface of the wedge member and the pressed surface of the lock gear is located radially inward on the pressing surface.

[0018] In the above-described reclining device, it is preferable that the curved surface of the pressed surface has an arc shape, and the center of the arc of the curved surface is within a range of a predetermined width including the center line of the lock gear.

[0019] With this configuration, it is possible to more reliably achieve that the contact point between the pressing surface of the wedge member and the pressed surface of the lock gear is located radially inward on the pressing surface.

[0020] In the above-described reclining device, it is preferable that the wedge member further has a cam contact surface that contacts the cam, and that the pressing surface and the cam contact surface each have an arc shape.

[0021] In this configuration, regardless of variations in the dimensional accuracy of the lock gear and the wedge member, the wedge member can receive a pressing force from the cam and press the lock gear smoothly and reliably.

[0022] In the above-described reclining device, it is preferable that the pressing surface and the cam contact surface have shapes that are line-symmetrical with each other across a line perpendicular to the guide wall portion.

[0023] In this configuration, the wedge member has the same shape even when the pressing surface and the cam abutment surface are reversed in the radial direction, and there is no risk of incorrect assembly even if the wedge member is assembled upside down, so assembly is easy.

[0024] The seat of the present invention is characterized by comprising a seat cushion, a seat back arranged at the rear of the seat cushion and capable of tilting in the fore-and-aft direction of the seat, and the above-mentioned reclining device that fixes the seat back at any tilt angle.

[0025] In a seat having such a configuration, the reclining device described above can reduce rattle of the lock gear in the locked state, which in turn can reduce rattle of the seat back. [Effects of the Invention]

[0026] According to the reclining device and seat of the present invention, rattle of the lock gear in the locked state can be suppressed. [Brief explanation of the drawings]

[0027] [Figure 1] 1 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] FIG. 2 is an exploded perspective view of the reclining mechanism of FIG. 1. [Figure 3] 3 is a perspective view of the cam, a pair of lock gears, a pair of sub-lock gears, a pair of wedge members, and a rotating plate shown in FIG. 2. FIG. [Figure 4] FIG. 4 is a diagram showing the completed state of the reclining mechanism in which the internal gear, a pair of main lock gears, a pair of sub-lock gears, a pair of wedge members, a cam, a guide bracket, and an attachment ring in FIG. 3 are combined. [Figure 5] 5 is an enlarged view showing a state in which the upper main lock gear in FIG. 4 is in an engaged position and the wedge member is in contact with the cam. FIG. [Figure 6] 6 is an explanatory diagram showing a load path starting from a pressing force from the cam in the cam, the wedge member, and the lock gear in FIG. 5. FIG. [Figure 7] 7 is an enlarged view of the vicinity of the contact point between the pressing surface of the wedge member and the pressed surface of the lock gear in FIG. 6. [Figure 8]10 is an explanatory diagram illustrating that the pressing surface and the cam contact surface of the wedge member have shapes that are line-symmetrical with respect to a line L3 that is perpendicular to the center line C. FIG. [Figure 9] 1A and 1B are diagrams showing the structure of a conventional reclining device. [Figure 10] FIG. 10 is an enlarged view of the lock gear and the wedge member of FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0028] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] As shown in FIG. 1, the seat 1 of this embodiment is a seat for a vehicle or the like, and includes a seat cushion 2 that supports the buttocks of a seated occupant, a seat back 3 that is disposed at the rear of the seat cushion 2 to support the back of the seated occupant and can be tilted in the front-to-rear direction X of the seat 1 relative to the seat cushion 2, a slide device 4 attached to the bottom of the seat cushion 2, and a reclining device 5.

[0030] The slide device 4 has a configuration that guides the seat cushion 2 so that it can slide in the front-rear direction X of the seat 1 and can fix the seat cushion 2 at any position. Note that the slide device 4 is not essential for the seat of the present invention and may be omitted.

[0031] The reclining device 5 has, as its main component, a reclining mechanism 6 that can fix the seat back 3 at any tilt angle. The reclining mechanism 6 is a part that includes the components of the reclining device of the present invention.

[0032] 1, the reclining device 5 of this 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 bushings 8 fitted near the ends on both sides of the connecting rod 7. The resin bushings 8 may be omitted.

[0033] The pair of reclining mechanisms 6 are disposed on both sides of the seat 1 in the width direction Y. Each reclining mechanism 6 is a mechanism for fixing the seat back 3 at an arbitrary tilt angle.

[0034] As shown in Figures 2 to 4, the reclining mechanism 6 comprises a disk-shaped guide bracket 20, an internal gear 30 arranged opposite the guide bracket 20 and having internal teeth 32, four lock gears 60A to 60D having external teeth 63 that can mesh with the internal teeth 32, namely a pair of main lock gears 60A, 60C and a pair of sub-lock gears 60B, 60D, a cam 50 that moves these four lock gears 60A to 60D radially of the guide bracket 20, at least one lock spring 40 (two in this embodiment) that rotates the cam 50, a pair of wedge members 80, an attachment ring 70 that attaches the internal gear 30 to the guide bracket 20, and a rotating plate 90 that rotates together with the cam 50. The pair of wedge members 80 are interposed between at least one of the four lock gears 60A-60D (in this embodiment, the pair of main lock gears 60A, 60C) and the cam 50, and are also interposed between each of the pair of main lock gears 60A, 60C and the guide wall portion 25A. With this arrangement, the pair of wedge members 80 press each of the pair of main lock gears 60A, 60C by receiving a pressing force from the cam 50. The rotating plate 90, the four lock gears 60A-60D, the cam 50, the pair of wedge members 80, and the two lock springs 40 are disposed between the guide bracket 20 and the internal gear 30.

[0035] The four lock gears 60A to 60D, i.e., a pair of main lock gears 60A, 60C and a pair of sub lock gears 60B, 60D, are arranged spaced apart in the circumferential direction of the internal gear 30 and are movable along the guide bracket 20 in the radial direction of the guide bracket 20 between an engagement position where their external teeth 63 engage with the internal teeth 32 of the internal gear 30 and a release position where they are released from this engagement. Specifically, the main lock gears 60A, 60C each have external teeth 63 that can mesh with the internal teeth 32 and are lock gears that perform strong meshing when pressed by the cam 50 via the wedge member 80. On the other hand, the sub lock gears 60B, 60D have external teeth 63 that can mesh with the internal teeth 32 and are lock gears that mesh with the internal teeth 32 to complement the strong meshing (lock strength) of the main lock gears 60A, 60C. In this embodiment, a small spiral spring is used as the lock spring 40.

[0036] Here, "strong meshing" of the main lock gears 60A, 60C means that the external teeth 63 and the internal teeth 32 mesh in a state where their tooth surfaces come into contact and press against each other. On the other hand, the sub-lock gears 60B, 60D are not required to mesh as strongly as the main lock gears 60A, 60C, where the external teeth 63 and the internal teeth 32 press against each other; they only need to mesh to complement the strong meshing (locking strength) of the main lock gears 60A, 60C.

[0037] The guide bracket 20 is a plate-shaped member having a circular center hole 22 in the center. The guide bracket 20 of this embodiment is fixed to either the seat cushion 2 or the seat back 3 near the rear of the frame 2a (see FIG. 1) (specifically, the side frame) of the seat cushion 2.

[0038] Specifically, as shown in FIG. 2, the guide bracket 20 has a disk-shaped main body portion 21 with a circular center hole 22 formed in the center, two accommodating portions 23 that each accommodate a lock spring 40, and a flange portion 24 provided along the outer periphery of the main body portion 21.

[0039] Each of the two accommodating portions 23 is recessed toward the outer surface 21a of the guide bracket 20, opens toward the inner surface 21b of the main body 21, and communicates with the center hole 22. Therefore, with the spiral portion of the lock spring 40 accommodated in the accommodating portion 23, the outer end portion 41 of the lock spring 40 can protrude into the center hole 22.

[0040] 2 and 4, the guide bracket 20 further has a plurality of guide wall portions 25 (guide portions) on the inner surface 21b of the main body portion 21 that guide the four lock gears 60A to 60D in the radial direction of the guide bracket 20. The plurality of guide wall portions 25 are provided around the center hole 22 at equal intervals in the circumferential direction and extend radially in the radial direction of the guide bracket 20. More specifically, the plurality of guide wall portions 25 are formed in pairs around the center hole 22 and extend radially in four directions. This makes it possible for the four pairs of guide wall portions 25 to guide the four lock gears 60A to 60D in the radial direction of the guide bracket 20.

[0041] The internal gear 30 is fixed to the other of the seat cushion 2 and the seat back 3 near the lower part of the frame 3a (see FIG. 1) (specifically, the side frame) of the seat back 3 at a position opposite the guide bracket 20.

[0042] As shown in FIG. 2 , the internal gear 30 has a recessed portion 31 that is circular when viewed in the axial direction of the internal gear 30 and has a generally recessed cross section. Internal teeth 32 are formed on the inner circumferential surface of the recessed portion 31 over the entire circumference of the inner circumferential surface. The internal gear 30 is disposed so that the bottom surface of the recessed portion 31 faces the inner surface 21b of the main body portion 21 of the guide bracket 20. A through-hole 33 is formed in the center of the recessed portion 31. The through-hole 33 is disposed so as to overlap with a through-hole (not shown) in the frame 3a of the seat back 3. The respective ends of the connect rod 7 and the resin bushing 8 are inserted into the reclining mechanism 6 through the through-hole 33.

[0043] 2, with the guide bracket 20 and the recessed portion 31 of the internal gear 30 facing each other, the peripheral edge of the recessed portion 31 is fitted into the guide bracket 20. This positions the internal gear 30 radially relative to the guide bracket 20.

[0044] Furthermore, the mounting ring 70 is fixed to the flange portion 24 by welding or the like to prevent the internal gear 30 from coming off in the axial direction. This allows the internal gear 30 to be connected to the guide bracket 20 so as to be rotatable relative to it.

[0045] As shown in FIGS. 2 to 4, the four lock gears 60A to 60D are members (so-called lock plates) having a generally rectangular shape in a plan view, each of which has external teeth 63 that can mesh with the internal teeth 32 of the internal gear 30. The lock gears 60A to 60D are arranged movably along the inner surface 21b of the guide bracket 20 while being guided in the radial direction of the guide bracket 20 by the guide wall portion 25 formed on the inner surface 21b. This allows the lock gears 60A to 60D to move between an engagement position where the external teeth 63 and the internal teeth 32 mesh with each other and a release position where the meshing is released. As shown in FIG. 2, a protrusion 61 that protrudes radially inward is formed on the inner circumferential surface of each lock gear 60A to 60D, facing the main gear-side protrusion 54 of the cam 50. Furthermore, an inner support protrusion 62 that protrudes in the direction of the rotation axis of the cam 50 is formed at a position near the protrusion 61 on the radially inner side of each of the lock gears 60A to 60D.

[0046] As shown in FIGS. 2 to 4, the pair of main lock gears 60A, 60C are arranged facing each other in the vertical direction so as to be aligned linearly with the cam 50 therebetween.

[0047] The pair of sub lock gears 60B, 60D are arranged opposite to the pair of main lock gears 60A, 60C at a distance of 90 degrees in the circumferential direction of the cam 50 and aligned linearly with the cam 50 in between.

[0048] As shown in Figures 2 to 4, a pair of main lock gears 60A, 60C aligned vertically and facing each other radially are common to the sub lock gears 60B, 60D in that they have the above-mentioned external teeth 63, protrusions 61, and inner support protrusions 62, but differ in that they have a pressed surface 64 and outer support protrusions 66 (dowels) shown in Figures 3 and 5.

[0049] 3 and 5, the pressed surface 64 is an inclined surface that extends in a direction inclined with respect to the radial direction on the inner peripheral side of the main lock gears 60A, 60C, and is a surface that is pressed by the wedge member 80 (specifically, the pressing surface 80c). The pressed surface 64 is arranged in a position aligned with the protrusion 61 in the circumferential direction. In other words, the pressed surface 64 is arranged in a position close to one guide wall portion 25A of the pair of guide wall portions 25A, 25B, and the protrusion 61 is arranged in a position close to the other guide wall portion 25B.

[0050] The outer support protrusion 66 is a protrusion that protrudes in the thickness direction at the width center of the main lock gears 60A, 60C, and is housed in the recessed portion 31 of the internal gear 30 and abuts against an arc-shaped step portion 31a (free zone) that protrudes inward and is formed in the recessed portion 31.

[0051] In this embodiment, the wedge member 80 has an approximately triangular wedge shape and is interposed between the pressed surface 64 of the main lock gears 60A, 60C, the guide wall portion 25 (more specifically, the guide wall portion 25A on the wedge member 80 side in Figure 5), and the cam 50, and is arranged in a state where it is sandwiched between the pressed surface 64 and the guide wall portion 25.

[0052] As shown in Figures 2 to 8, the wedge member 80 has an arc-shaped cam abutment surface 80a that contacts the cam 50 (specifically, the outer peripheral surface of the wedge abutment protrusion 55 described below), a flat guide wall abutment surface 80b that abuts against the guide wall portion 25A, and an arc-shaped pressing surface 80c that presses the pressed surfaces 64 of the main lock gears 60A and 60C.

[0053] 5 and 7, at least one of the pressing surface 80c and the pressed surface 64 of the main lock gears 60A, 60C (both in this embodiment) has a shape in which at least a portion thereof protrudes in the direction facing each other. In this embodiment, the pressing surface 80c is an arcuate surface that curves entirely toward the pressed surface 64. The pressed surface 64 also has a curved surface 64a that protrudes radially inward toward the pressing surface 80c.

[0054] 6 and 7, the pressing surface 80c and the pressed surface 64 come into contact at a contact point P1. Note that the contact point P1 is the point where the pressing surface 80c and the pressed surface 64 come into contact when viewed from the axial direction of the internal gear 30, but in reality, at the contact point P1, the pressing surface 80c and the pressed surface 64 are in line contact in the thickness direction of the main lock gears 60A, 60C.

[0055] 6, a perpendicular line L2 perpendicular to a tangent line L1 passing through a contact point P1 where the pressing surface 80c and the pressed surface 64 come into contact with each other intersects at a contact point L2 with a center line C extending radially through the center of the circumferential width of the main lock gears 60A, 60C at an intersection point P2. The tangent line L1 here is a common tangent to the pressing surface 80c and the pressed surface 64 at the contact point P1.

[0056] An intersection point P2 between the perpendicular line L2 and the center line C exists in a region R that is radially inward of the radially outer ends 251 of the guide wall portions 25A and 25B on both sides of the center line C. The radially innermost position of the region R is set, for example, to the radially innermost position 252 of the contact portion between the guide wall portions 25A and 25B and the main lock gears 60A and 60C.

[0057] The pressing surface 80c and the pressed surface 64 each have a portion that protrudes in a direction opposite to each other. In this embodiment, the pressing surface 80c is an arcuate surface (an arc with a radius of curvature R1 in FIG. 7) that curves entirely toward the pressed surface 64. The pressed surface 64 has a curved surface 64a that protrudes radially inward toward the pressing surface 80c.

[0058] In this embodiment, the pressed surface 64 includes the arc-shaped curved surface 64a that is curved so as to protrude in the direction facing the pressing surface 80c, as described above. Moreover, as shown in Fig. 7, the arc center O of the arc A1 (the arc with the radius of curvature R2 in Fig. 7) of the arc-shaped curved surface 64a of the pressed surface 64 is within a range of a predetermined width W that includes the center line C of the main lock gears 60A, 60C (preferably, on or immediately adjacent to the center line C).

[0059] As shown in FIGS. 5 to 8, the pressing surface 80c and the cam contact surface 80a of this embodiment each have an arc shape.

[0060] More specifically, as shown in FIG. 8, the pressing surface 80c and the cam contact surface 80a have shapes that are line-symmetrical with each other across a line L3 that is perpendicular to the guide portion 25.

[0061] Other configurations are as follows: As shown in Figures 2 to 4, the pair of sub lock gears 60B, 60D, unlike the main lock gears 60A, 60C, have a shape that is integrated with the wedge member 80. That is, as shown in Figure 3, the sub lock gears 60B, 60D have sub-side protrusions 67 that protrude radially inward on their radially inner sides and correspond to the wedge member 80.

[0062] The cam 50 is rotatable relative to the guide bracket 20 between a predetermined lock angle and an unlock angle. As shown in Figures 2 and 3, the cam 50 has a main body 51, a shaft 52 that protrudes from the main body 51 toward the guide bracket 20 in the axial direction of the cam 50 and is inserted into the center hole 22 of the guide bracket 20, and a pair of engagement protrusions 53 that engage with the rotation plate 90 (specifically, engagement holes 92, which will be described later).

[0063] 3 to 5, the main body 51 of the cam 50 has eight protrusions 54 to 57 that are multiple operating parts that move each of the four lock gears 60A to 60D in the radial direction. Specifically, the main body 51 has a pair of main gear side protrusions 54, a pair of wedge abutment protrusions 55, a pair of sub-gear first protrusions 56, and a pair of sub-gear second protrusions 57. A gap is provided between the pair of main gear side protrusions 54 and the protrusions 61 of the main lock gears 60A and 60C. The pair of wedge abutment protrusions 55 abut against a pair of wedge members 80.

[0064] As the cam 50 rotates from the release angle to the lock angle due to the rotational biasing force of the lock spring 40 shown in Figure 2, the above-mentioned protrusions 54 to 57 of the cam 50 come into contact with the four lock gears 60A to 60D, respectively, and press the four lock gears radially outward from the cam 50, moving them to the meshing position.

[0065] As shown in Figure 3, a rod engagement hole 58 is formed in the center of the main body 51 of the cam 50. The end of the connect rod 7 in Figure 1 engages with the rod engagement hole 58 through the through hole 33 of the internal gear 30. By manually rotating the connect rod 7, the cam 50 inside the reclining mechanism 6 can be rotated.

[0066] In this embodiment, the shaft portion 52 of the cam 50 is configured with a plurality of (two in this embodiment) protrusions that protrude from the main body portion 51 in the axial direction.

[0067] 2 engages with the shaft portion 52, whereby the lock spring 40 rotationally biases the cam 50 from the release angle to the lock angle. Specifically, as shown in Fig. 4, the protrusions 54 to 57 protruding radially outward from the cam 50 press the protrusions 61 of all of the lock gears 60A to 60D, and also press the pair of wedge members 80 pressing the pair of main lock gears 60A, 60C and the sub-side protrusions 67 of the pair of sub lock gears 60B, 60D radially outward from the cam 50, so that the lock spring 40 rotationally biases the cam 50 in a direction that moves the external teeth 63 of these lock gears 60A to 60D to an engagement position where they mesh with the internal teeth 32 of the internal gear 30.

[0068] The cam 50 is rotatably supported relative to the guide bracket 20 by the outer peripheral surface of the shaft portion 52 abutting against the inner peripheral surface of the center hole 22 of the guide bracket 20 .

[0069] As shown in Figure 2, the two lock springs 40 are accommodated in the above-mentioned accommodation section 23 on the inner surface 21b side of the main body 21 of the guide bracket 20, and are thereby evenly arranged circumferentially around the center hole 22, i.e., in this embodiment, on both sides of the center hole 22.

[0070] The lock spring 40 of this embodiment is a spiral spring formed by spirally winding a strip-shaped thin metal plate, and has an outer end 41 and an inner end 42. The inner end 42 engages with an engaging protrusion 23a provided in a recess of the accommodation portion 23 of the guide bracket 20.

[0071] The outer end 41 is engaged with the shaft 52 of the cam 50. As a result, the two lock springs 40 can each apply rotational force to the cam 50 in a direction that displaces the four lock gears 60A to 60D from the release position to the meshing position.

[0072] As shown in FIG. 3, the rotating plate 90 is a plate-like member that rotates together with the cam 50. The rotating plate 90 has a central through-hole 91 through which the connect rod 7 passes, a pair of engagement holes 92 that engage with the pair of engagement protrusions 53 of the cam 50, and four guide holes 93 into which the inner support protrusions 62 of each of the lock gears 60A to 60D are inserted. The pair of engagement protrusions 53 of the cam 50 engage with the pair of engagement holes 92, causing the rotating plate 90 to rotate integrally with the cam 50. Therefore, the inner circumferential surfaces of the guide holes 93 come into contact with the inner support protrusions 62 of each of the lock gears 60A to 60D as the rotating plate 90 rotates. This makes it possible to move each of the lock gears 60A to 60D from the meshed position to a disengaged position radially inward.

[0073] In the reclining mechanism 6 described above, switching between a locked state and an unlocked state is performed as follows. In the normal locked state, the cam 50 is biased in the locked direction by the rotational biasing force of the lock spring 40. In this state, a pair of protrusions 55 projecting radially outward from the cam 50 press a pair of wedge members 80 radially outward from the cam 50. The pressing force from the wedge members 80 strongly presses the pair of main lock gears 60A, 60C radially outward, maintaining them in the meshed position. This not only ensures that the external teeth 63 of these gears are firmly meshed with the internal teeth 32 of the internal gear 30, but also reduces (tightens) the widthwise clearance of the main lock gears 60A, 60C, thereby suppressing rattling.

[0074] On the other hand, when a rotational operating force is input to the connect rod 7, the cam 50 rotates in the opposite direction to the biasing direction of the lock spring 40, eliminating the pressing force of the protrusion 55 of the cam 50 pressing the two main lock gears 60A, 60C radially outward. At this time, the rotation plate 90 rotates together with the cam 50, and the inner support protrusions 62 of each lock gear 60A-60D are pressed radially inward by the inner circumferential surfaces of the guide holes 93. This pulls the four lock gears 60A-60D radially inward, displacing them from the meshed position to the unlocked position and establishing an unlocked state. In the unlocked state, the seat back 3 can be adjusted to any angle. After the seat back 3 is adjusted to any angle, removing the rotational operating force on the connect rod 7 restores the locked state due to the rotational biasing force of the lock spring 40.

[0075] (Features of this embodiment) (1) In the reclining mechanism 6 of this embodiment, as shown in FIGS. 3 and 5, the wedge member 80 is interposed between the pressed surface 64 of the main lock gears 60A, 60C and the guide wall portion 25A. The wedge member 80 has a pressing surface 80c that presses the main lock gears 60A, 60C by receiving a pressing force from the cam 50. The main lock gears 60A, 60C have a pressed surface 64 that extends in a direction inclined relative to the radial direction and is pressed by the pressing surface 80c of the wedge member 80. As shown in FIGS. 5 and 7, at least one of the pressing surface 80c and the pressed surface 64 (both in this embodiment) has a shape in which at least a portion of the pressing surface 80c and the pressed surface 64 protrudes in a direction opposite to each other. In this embodiment, the pressing surface 80c is an arcuate surface that curves entirely toward the pressed surface 64. The pressed surface 64 also has a curved surface 64a that protrudes toward the pressing surface 80c on the radially inner side.

[0076] As shown in FIG. 6, a perpendicular line L2, which is perpendicular to a tangent line L1 passing through a contact point P1 where the pressing surface 80c and the pressed surface 64 come into contact with each other, intersects with a center line C extending radially through the center of the circumferential width of the main lock gears 60A, 60C.

[0077] An intersection P2 between the perpendicular line L2 and the center line C exists in a region R that is radially inward of the radially outer ends 251 of the guide wall portions 25A, 25B on both sides of the center line C.

[0078] 6, in this configuration, the contact point P1 between the pressing surface 80c of the wedge member 80 and the pressed surface 64 of the main lock gears 60A, 60C is reliably located at a radially inner position on the pressing surface 80c. Therefore, the pressing force F2 generated when the pressing surface 80c of the wedge member 80 presses the pressed surface 64 of the main lock gears 60A, 60C at the contact point P1 with the pressed surface 64 is directed in a direction along the perpendicular line L2, and is divided into forces F21 and F22 directed in the circumferential direction and radial direction at the intersection P2 between the perpendicular line L2 and the center line C, so that the force F21 that presses the main lock gears 60A, 60C in the circumferential direction against the guide wall portion 25B on the opposite side to the wedge member 80 can be reliably obtained. By defining the load path in this way, the posture of the main lock gears 60A, 60C can be stabilized by being pressed firmly against the guide wall portion 25B on the opposite side of the wedge member 80 at the center line C. As a result, the posture of the main lock gears 60A, 60C is stabilized during movement, and rattle of the main lock gears 60A, 60C in the locked state can be reduced.

[0079] (2) In the reclining mechanism 6 of this embodiment, the pressing surface 80c and the pressed surface 64 each have a portion that protrudes in the direction opposite to each other. In this embodiment, the pressing surface 80c is an arcuate surface that curves overall toward the pressed surface 64. The pressed surface 64 also has a curved surface 64a that protrudes radially inward toward the pressing surface 80c.

[0080] With this configuration, the contact point P1 between the pressing surface 80c of the wedge member 80 and the pressed surface 64 of the main lock gears 60A, 60C can be positioned further radially inward on the pressing surface 80c. As a result, the main lock gears 60A, 60C can firmly press the guide wall portion 25B on the opposite side of the center line C from the wedge member 80, thereby more stabilizing the posture of the main lock gears 60A, 60C.

[0081] There are no particular limitations on the shapes of the protruding portions of the pressing surface 80c and the pressed surface 64. For example, the pressing surface 80c and the pressed surface 64 may be mostly formed of flat surfaces facing each other, with a protruding portion provided on a portion. Alternatively, the pressing surface 80c and the pressed surface 64 may be formed of arcuate surfaces that protrude in opposing directions. This configuration allows the pressing surface 80c and the pressed surface 64 to reliably come into point contact at one point.

[0082] (3) In the reclining mechanism 6 of this embodiment, the pressed surface 64 includes a curved surface 64a that is curved so as to protrude in a direction facing the pressing surface 80c.

[0083] With this configuration, the curved surface 64a of the pressed surface 64 can reliably contact the pressing surface 80c of the wedge member 80, making it possible to further stabilize the posture of the main lock gears 60A, 60C. This makes it possible to achieve smooth locking between the main lock gears 60A, 60C and the internal gear. It also makes it possible to reliably ensure that the contact point P1 between the pressing surface 80c of the wedge member 80 and the pressed surface 64 of the main lock gears 60A, 60C is located radially inward on the pressing surface 80c.

[0084] (4) 7, in the reclining mechanism 6 of this embodiment, the arc center O of the arc-shaped curved surface 64a of the pressed surface 64 is within a range of a predetermined width W that includes the center line C of the main lock gears 60A, 60C (preferably, on or immediately adjacent to the center line C). This configuration makes it possible to more reliably ensure that the contact point P1 between the pressing surface 80c of the wedge member 80 and the pressed surface 64 of the main lock gears 60A, 60C is located radially inward on the pressing surface 80c.

[0085] (5) 5 to 8, in the reclining mechanism 6 of this embodiment, the wedge member 80 has a cam contact surface 80a that comes into contact with the cam 50. The pressing surface 80c and the cam contact surface 80a each have an arc shape.

[0086] With this configuration, regardless of variations in the dimensional accuracy of the main lock gears 60A, 60C and the wedge member 80, the wedge member 80 can receive a pressing force from the cam 50 and smoothly and reliably press the main lock gears 60A, 60C.

[0087] (6) In the reclining mechanism 6 of this embodiment, as shown in FIG. 8, the pressing surface 80c and the cam contact surface 80a have shapes that are line-symmetrical with each other across a line L3 that is perpendicular to the guide wall portion.

[0088] In this configuration, the wedge member 80 has the same shape even when the pressing surface 80c and the cam abutment surface 80a are reversed in the radial direction, and there is no risk of incorrect assembly even if the wedge member 80 is assembled upside down, so assembly is easy.

[0089] (7) The seat 1 of this embodiment includes a seat cushion 2, a seat back 3 disposed at the rear of the seat cushion 2 and tiltable in the front-to-rear direction of the seat, and the reclining mechanism 6 that fixes the seat back 3 at a desired tilt angle. Therefore, since the seat 1 includes the reclining mechanism 6, it is possible to suppress rattle of the main lock gears 60A, 60C in the locked state. As a result, it is possible to suppress rattle of the seat back 3.

[0090] (Variation) (A) In the above embodiment, a configuration is shown in which four lock gears 60A to 60D are provided as the multiple lock gears, and a pair of main lock gears 60A, 60C that face each other in the radial direction have wedge members 80, but the present invention is not limited to this. In the present invention, it is sufficient that at least one lock gear among the multiple lock gears has a wedge member.

[0091] (B) In the above embodiment, the wedge member 80 has a substantially triangular shape, but the present invention is not limited to this. As shown in FIG. 8 , the wedge member 80 has a cam abutment surface 80a that contacts the pressing surface 52a of the cam 50, and various shapes can be used as long as the shape allows it to be sandwiched between the pressed surface 64 and the guide wall portion 25A. Therefore, the wedge member of the present invention may be not only triangular, but also trapezoidal or substantially pentagonal in shape. Even with wedge members of these shapes, it is possible to move the main lock gears 60A, 60C radially outward without wobbling while pressing them against the guide wall portion 25B.

[0092] (C) In the above embodiment, the guide bracket 20 is fixed to the frame 2a of the seat cushion 2, and the internal gear 30 is fixed to the frame 3a of the seat back 3. However, the present invention is not limited to this, and the guide bracket 20 and the internal gear 30 may be arranged in an interchangeable manner. In other words, the internal gear 30 may be fixed to the frame 2a of the seat cushion 2, and the guide bracket 20 may be fixed to the frame 3a of the seat back 3. [Explanation of symbols]

[0093] 1 sheet 2 seat cushions 2a frame 3 Seat back 3a frame 4 Slide mechanism 5 Reclining device 6 Reclining mechanism 7 Connecting Rod 20 Guide bracket 30 Internal gear 32 Inner teeth 40 Rock Spring 50 Cam 60A, 60C main lock gear 60B, 60D sub-lock gear 63 Outer teeth 64 Pressed surface 64a curved surface 70 Mounting ring 80 Wedge member 80a Cam contact surface 80b Guide wall contact surface 80c pressing surface

Claims

1. a guide bracket fixed to one of the seat cushion and the seat back; an internal gear fixed to the other of the seat cushion and the seat back at a position facing the guide bracket and rotatable relative to the guide bracket; a plurality of lock gears each having external teeth that can mesh with the internal teeth of the internal gear, the lock gears being arranged spaced apart in the circumferential direction of the internal gear and movable in the radial direction of the guide bracket along the guide bracket between an engagement position where the external teeth and the internal teeth mesh with each other and a release position where the engagement is released; a cam that moves the plurality of lock gears radially from the release position to the engagement position; a lock spring that rotates the cam in a direction in which the plurality of lock gears move toward the meshing position; a wedge member that presses at least one lock gear among the plurality of lock gears by receiving a pressing force from the cam toward the outside in the radial direction; Equipped with the guide bracket has a plurality of pairs of guide wall portions that face each other and guide the plurality of lock gears in the radial direction, the wedge member is interposed between the guide wall portion and the lock gear and has a pressing surface that presses the lock gear by receiving a pressing force from the cam, the lock gear has a pressed surface that is pressed by the pressing surface of the wedge member and extends in a direction inclined with respect to the radial direction, At least one of the pressing surface and the pressed surface has a shape in which at least a portion thereof protrudes in a direction facing each other, a perpendicular line perpendicular to a tangent line passing through a contact point where the pressing surface and the pressed surface come into contact with each other at the contact point intersects with a center line extending in the radial direction and passing through a center of the width of the lock gear in the circumferential direction, an intersection of the perpendicular line and the center line is located in a region radially inward of radially outer ends of the guide wall portions on both sides of the center line; A reclining device characterized by the above.

2. The reclining device according to claim 1, The pressing surface and the pressed surface each have a portion protruding in a direction opposite to each other. A reclining device characterized by the above.

3. The reclining device according to claim 1 or 2, The pressed surface includes a curved surface that is curved so as to protrude in a direction facing the pressing surface. A reclining device characterized by the above.

4. The reclining device according to claim 3, The curved surface of the pressed surface has an arc shape, The arc center of the curved surface is within a range of a predetermined width including the center line of the lock gear. A reclining device characterized by the above.

5. The reclining device according to claim 1 or 2, the wedge member further has a cam abutment surface that abuts against the cam, The pressing surface and the cam contact surface each have an arc shape. A reclining device characterized by the above.

6. The reclining device according to claim 5, the pressing surface and the cam contact surface have shapes that are line-symmetrical with each other across a line perpendicular to the guide wall portion, A reclining device characterized by the above.

7. Seat cushion and a seat back disposed at a rear portion of the seat cushion and tiltable in the front-rear direction of the seat; The reclining device according to claim 1 or 2, wherein the seat back is fixed at an arbitrary inclination angle. Equipped with A sheet characterized by:

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