Vehicle seat reclining device

Abstract

To provide a seat reclining device for a vehicle which can properly latch a lock spring.SOLUTION: A seat reclining device 4 for a vehicle includes a lock spring 50 consisting of a spiral spring which energizes a rotary cam 40 rotatably assembled with a guide 20 in a rotational direction for locking. The guide 20 includes: a storage hole 21A which stores the lock spring 50 in an axial direction; a locking hole 21Aa which extends from the storage hole 21A to lock an outer end part 52 of the lock spring 50; and a diameter reduction part 21Ab formed by reducing diameter at a part of the storage hole 21A which is abutted from an outer side in a radial direction to a wound part 53 extending in a spiral shape from an inner end part 51 of the lock spring 50 locked at the rotary cam 40 to the outer end part 52. The diameter reduction parts 21Ab are, when the seat reclining device 4 for a vehicle is locked, abutted to the wound part 53 in a sandwiching state in a radial direction from a plurality of portions in the rotational direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat reclining device, and more particularly to a vehicle seat reclining device having a locking mechanism that allows the reclining angle of a seat back to be adjusted. [Background technology]

[0002] Patent Document 1 discloses a vehicle seat reclining device that can adjust the reclining angle of the seat back by a predetermined pitch angle. This vehicle seat reclining device includes a ratchet connected to the seat back and a guide connected to the seat cushion, which are assembled axially so that they can rotate relative to each other.

[0003] A locking mechanism is provided between the ratchet and the guide, which can releasably lock the relative rotation between them. The locking mechanism includes a rotating cam provided at the center of the guide and a pawl that is pushed outward in the radial direction by the rotation of the rotating cam and engages with the ratchet. The rotating cam is normally pushed and held in the rotational direction that engages the pawl with the ratchet by the biasing force of a locking spring, which is a spiral spring hooked between the rotating cam and the guide. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-22400 Summary of the Invention [Problem to be solved by the invention]

[0005] The lock spring is set in a receiving hole drilled in the center of the guide, with its inner end engaged with the rotating cam and its outer end engaged with a locking hole extending from the receiving hole. Therefore, when the vehicle seat reclining device is transported as an assembly, there is a risk that the lock spring may become dislodged from the receiving hole and fall off due to vibrations, etc. Therefore, the present invention provides a vehicle seat reclining device that can appropriately prevent the lock spring from becoming dislodged. [Means for solving the problem]

[0006] To solve the above problems, the vehicle seat reclining device of the present invention employs the following means. That is, a first aspect of the present invention is a vehicle seat reclining device comprising: a ratchet and a guide axially assembled so as to be rotatable relative to each other; a rotating cam rotatably assembled to the guide; a pawl assembled to the guide and engaging with the ratchet when the rotating cam rotates in one direction, thereby locking the rotation; and a lock spring consisting of a spiral spring that rotates the rotating cam in the one direction relative to the guide, wherein the guide has an accommodating hole that axially accommodates the lock spring, a hooking hole extending from the accommodating hole and engaging an outer end of the lock spring, and a reduced diameter portion formed by reducing the diameter of a part of the accommodating hole so as to abut from the outside in the radial direction against a winding portion of the lock spring that extends spirally from the inner end that is hooked to the rotating cam toward the outer end, and wherein the reduced diameter portion is abutted against the winding portion from multiple points in the rotational direction in a radially sandwiched manner against the winding portion when the pawl is in a locked state in which it is engaged with the ratchet.

[0007] According to the first aspect of the present invention, the reduced diameter portion of the guide is fitted to the winding portion of the lock spring so as to sandwich it in the radial direction, making it difficult for the winding portion to shift axially relative to the guide, thereby making it possible to appropriately prevent the lock spring from falling out of the accommodation hole.

[0008] A second aspect of the present invention is the vehicle seat reclining device according to the first aspect, wherein the reduced diameter portions are provided at two positions in the rotation direction on either side of the rotation center of the guide.

[0009] According to the second aspect of the present invention, the number of contact points of the reduced diameter portion can be minimized, thereby ensuring a longer effective flexible length on the inner end side of the winding portion of the lock spring, which allows the lock spring to bend even when pressed between the reduced diameter portions.

[0010] The third invention of the present invention is a vehicle seat reclining device according to the first or second invention, wherein the outermost portion of the reduced diameter portion that is in contact with the portion closest to the outer end of the wound portion is positioned to be in contact with the corner of the bent portion where the outer end of the wound portion is bent back.

[0011] According to the third aspect of the present invention, the reduced diameter portion can be positioned closer to the outer end of the winding portion, thereby ensuring a longer effective flexible length on the inner end side of the winding portion that can bend even when pressed between the reduced diameter portions.

[0012] A fourth aspect of the present invention is the vehicle seat reclining device according to the first or second aspect, wherein an outer portion in the axial direction of the lock spring is positioned within the accommodating hole.

[0013] According to the fourth aspect of the present invention, in addition to preventing the lock spring from falling off, the lock spring can be appropriately held in a state where it does not protrude from the receiving hole. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view illustrating a configuration of a vehicle seat reclining device according to a first embodiment. [Figure 2] FIG. 2 is an enlarged exploded perspective view showing a main part of FIG. 1. [Figure 3] FIG. 3 is an exploded perspective view of FIG. 2 as seen from the opposite side. [Figure 4]FIG. 2 is an exploded perspective view of the vehicle seat reclining device. [Figure 5] FIG. 5 is an exploded perspective view of FIG. 4 as seen from the opposite side. [Figure 6] FIG. 2 is an exterior side view of the vehicle seat reclining device. [Figure 7] FIG. 2 is a front side view of the vehicle seat reclining device. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] FIG. 9 is a cross-sectional view illustrating the unlocked state from FIG. 8. [Figure 10] FIG. 10 is an exterior side view of a vehicle seat reclining device according to a second embodiment. [Figure 11] FIG. 10 is an exterior side view of a vehicle seat reclining device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0016] (First embodiment) <<General Configuration of Vehicle Seat Reclining Device 4>> First, the configuration of a vehicle seat reclining device (hereinafter referred to as a recliner) 4 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 9. In the following description, when directions such as front, back, up, down, left, and right are indicated, they refer to the respective directions shown in the respective drawings. Furthermore, when the term "seat width direction" is used, it refers to the left and right direction of a seat 1, which will be described later. Furthermore, in the following description, when a specific reference drawing is not indicated or when there is no reference symbol corresponding to a reference drawing, any of FIGS. 1 to 9 will be referred to as appropriate.

[0017] As shown in FIG. 1, the recliner 4 according to this embodiment is applied to a seat 1 that constitutes the right-hand seat of an automobile. The recliner 4 is configured as a reclining adjustment mechanism that connects a seatback 2 that constitutes the backrest portion of the seat 1 to a seat cushion 3 that constitutes the seating portion so that the backrest angle can be adjusted. Specifically, a pair of recliners 4 are provided on the left and right between the seatback 2 and the seat cushion 3. Each recliner 4 can be simultaneously switched between a locked and unlocked state to fix or unlock the backrest angle of the seatback 2.

[0018] 2 and 3, each recliner 4 is assembled between the lower end of each side frame 2F forming the left and right side framework of the seat back 2 and each reclining plate 3F connected to the rear end of the left and right side framework of the seat cushion 3 located on the outer side of these frames in the seat width direction. As a result, each recliner 4 connects each side frame 2F of the seat back 2 to each reclining plate 3F so that they can rotate relative to each other about the same axis.

[0019] As shown in Figure 1, each recliner 4 is normally held in a locked state, fixing the angle of the seatback 2. When the user pulls up the reclining lever 5 located on the outer side (right side) of the seat cushion 3, the recliners 4 are simultaneously released from their locked state. This switches each recliner 4 to an unlocked state, allowing the angle of the seatback 2 to be adjusted in the fore-and-aft direction of the seat. When the reclining lever 5 is released, each recliner 4 is biased back into its locked state.

[0020] Return springs 6 are attached between each side frame 2F of the seat back 2 and each reclining plate 3F located outside of the side frame 2F, applying a rotational biasing force to the seat back 2 in a forward tilting direction. The rotational biasing force of these return springs 6 releases the fixed state of the backrest angle set by each recliner 4, and the seat back 2 is raised to a position where it will contact the back of a seated occupant.

[0021] The seat back 2 adjusts its angle forward and backward to follow the movement of the seated occupant as the back of the seated occupant tilts forward and backward. By setting the return spring 6 in this way, the angle of the seat back 2 can be easily adjusted.

[0022] 2 and 3, each recliner 4 specifically has a ratchet 10 coupled to the outer surface of each side frame 2F of the seat back 2, and a guide 20 coupled to the inner surface of each reclining plate 3F. Each recliner 4 is configured to fix or release the backrest angle of the seat back 2 by switching between locking and unlocking the rotation of the ratchet 10 relative to the guide 20.

[0023] <<Configuration of each part>> The specific configuration of each part of each recliner 4 will be described in detail below. Note that each recliner 4 has a bilaterally symmetrical configuration. Therefore, the following will describe in detail the configuration of the recliner 4 located on the outer side (right side) of the vehicle as shown in Figures 2 and 3.

[0024] 4 and 5, the recliner 4 has a generally disk-shaped ratchet 10 and a guide 20 that are axially assembled together. The recliner 4 also has three pawls 30 that are assembled between the ratchet 10 and the guide 20, and a rotating cam 40 that moves the pawls radially inward and outward.

[0025] The recliner 4 also has a lock spring 50, which is a spiral spring that urges the rotating cam 40 in the direction of lock rotation relative to the guide 20. The recliner 4 also has a substantially cylindrical outer ring 60 that is mounted across the outer peripheries of the ratchet 10 and the guide 20.

[0026] The outer ring 60 functions as a retaining ring that holds the ratchet 10 and the guide 20 in an axially assembled state so that they can rotate relative to each other. The ratchet 10, guide 20, three pawls 30, and rotating cam 40 are each hardened by quenching after press molding, giving them a high structural strength.

[0027] Ratchet 10 As shown in Figure 4, ratchet 10 is made of a single metal disk-shaped member cut into a roughly disk-like shape. Ratchet 10 is configured by half-punching various portions in the plate thickness direction (axial direction). Specifically, ratchet 10 is configured such that the outer peripheral edge of its main body plate 11 is half-punched into a stepped cylindrical shape that protrudes in two stages to the right (axial direction) in the figure, which is the assembly direction to guide 20.

[0028] The half-blanking outermost cylindrical portion is formed as a cylindrical portion 12 with internal teeth 12A formed over the entire inner peripheral surface. An intermediate cylindrical portion 13 is formed between the cylindrical portion 12 and the main body plate 11, connecting them in a stepped manner. The internal teeth 12A of the cylindrical portion 12 have a tooth surface shape that allows the external teeth 31 formed on the outer peripheral surface of each pole 30, which will be described later, to mesh with each other from the radially inner side. The internal teeth 12A are shaped so that the tooth surfaces are arranged at equal intervals of 2 degrees in the rotational direction.

[0029] 3, a circular through-hole 11A is formed in the center (position on the rotation center C) of the main body plate 11 of the ratchet 10. An operating pin 5A, which is inserted into the center of a rotating cam 40 (described later), is inserted into this through-hole 11A from the left side in the figure in a freely rotatable state.

[0030] The ratchet 10 has three dowels 14 formed on the outer surface of its main body plate 11 by half-punching to protrude to the left in the figure. The ratchet 10 is integrally joined to the side frame 2F of the seat back 2 by fitting the three dowels 14 into three corresponding fitting holes 2Fa formed in the side frame 2F and welding them. The side frame 2F has a through-hole 2Fb that penetrates in the axial direction in a circular hole shape at a position axially opposite to the through-hole 11A formed in the center of the ratchet 10. The above-mentioned operating pin 5A is inserted axially through this through-hole 2Fb from the left side in the figure.

[0031] Guide 20 As shown in Figure 5, the guide 20, like the ratchet 10 described above, is made of a single metal disk-shaped member cut into a generally disk-like shape. The guide 20 is cut into a generally disk-like shape with an outer diameter slightly larger than that of the ratchet 10, and is configured by half-punching parts in the thickness direction (axial direction). Specifically, the guide 20 is configured such that a cylindrical part 22 that protrudes cylindrically to the left (axial direction) in the figure, which is the assembly direction to the ratchet 10, is formed by half-punching on the outer peripheral edge of the main body plate 21.

[0032] The cylindrical portion 22 is formed so that its inner diameter is slightly larger than the outer diameter of the cylindrical portion 12 of the ratchet 10. The guide 20 is set in such a way that the cylindrical portion 12 of the ratchet 10 is loosely fitted into the cylindrical portion 22 in the axial direction.

[0033] As a result, the guide 20 is assembled to the ratchet 10 in a state where the cylindrical portions 22, 12 fit loosely together radially inward and outward, supporting each other so as to be rotatable relative to each other. An outer peripheral ring 60, which will be described later, is mounted between the cylindrical portion 22 and the cylindrical portion 12 of the ratchet 10 so as to straddle the guide 20 from the outer periphery, so that the guide 20 is assembled to the ratchet 10 in a state where it is prevented from coming off via the outer peripheral ring 60 (see FIGS. 2 and 3, 6 and 7).

[0034] As shown in Fig. 5, guide walls 23 are formed by half-punching on the inner surface of main body plate 21 of guide 20 at three positions in the rotational direction. These guide walls 23 protrude in a generally fan-like shape toward the left (axial direction) in the figure, which is the direction of assembly to ratchet 10. The outer peripheral surfaces of the guide walls 23 on their radially outer sides are curved to form arcs of the same circle drawn around rotation center C of guide 20. Each guide wall 23 is set so as to fit loosely in the axial direction within cylindrical portion 12 of ratchet 10 which is assembled into cylindrical portion 22 of guide 20.

[0035] By forming each guide wall 23, concave pole accommodating grooves 24A are formed on the inner surface of the main plate 21 of the guide 20 in the rotational spacing areas thereof, into which three poles 30 (described later) can be set one by one so as to be slidable only inward and outward in the radial direction. Also, a cam accommodating groove 24B is formed in the center of the inner surface of the main plate 21 surrounded by each guide wall 23, into which a rotating cam 40 (described later) can be set so as to be rotatable around a rotation center C.

[0036] 8 and 9, each guide wall 23 supports the corresponding pole 30 set in each pole receiving groove 24A from both sides in the rotational direction by means of the restriction surfaces 23A, which are the both side surfaces in the rotational direction of the pole 30. As a result, each guide wall 23 is configured to support the pole 30 set therebetween from both sides in the rotational direction so that the pole 30 can slide only radially inward and outward.

[0037] Furthermore, each guide wall 23 supports the rotating cam 40 set in the cam accommodating groove 24B between them from the outside in the radial direction by the support surfaces 23B that are their inner peripheral surfaces. As a result, each guide wall 23 supports the rotating cam 40 set therebetween so that it can rotate approximately at the center (rotation center C) on the main body plate 21 of the guide 20.

[0038] 4 and 5, a generally circular accommodation hole 21A, into which a lock spring 50 (described later) is fitted, is formed in the axial direction at the center (position on rotation center C) of main body plate 21 of guide 20. A locking hole 21Aa is formed in accommodation hole 21A at a portion in the rotational direction, causing the hole shape of accommodation hole 21A to partially extend radially outward in an elongated shape. An outer end portion 52 of lock spring 50 fitted into accommodation hole 21A is fitted axially into locking hole 21Aa so as to be integral with the accommodation hole 21A in the rotational direction.

[0039] As shown in FIG. 2, guide 20 has three dowels 21B formed on the outer surface of its main plate 21 by half-punching so as to protrude to the right in the figure. The three dowels 21B are fitted into three corresponding fitting holes 3Fa formed in reclining plate 3F and welded to the reclining plate 3F, thereby integrally joining guide 20 to the reclining plate 3F. A circular through-hole 3Fb is formed in the reclining plate 3F at a position axially opposite to the accommodation hole 21A formed in the center of guide 20. The operating pin 5A described above is inserted axially through this through-hole 3Fb from the left side in the figure.

[0040] "Paul 30" As shown in Figures 4 and 5, each of the three poles 30 is made of a single metal plate-like member cut into a substantially rectangular shape. Each pole 30 is configured by half-punching parts in the thickness direction (axial direction). Specifically, each pole 30 has an offset surface portion 30B that forms the radially inner portion thereof, which is half-punched to the left side (axial direction) in the figure, which is the assembly direction to the ratchet 10, relative to the main surface portion 30A that forms the radially outer portion thereof.

[0041] 8, each pole 30 is set in a state in which it is accommodated one by one in each pole accommodating groove 24A formed on the main body plate 21 of the guide 20. As a result of the above-described setting, each pole 30 is supported in a planar manner from both sides in the rotation direction by the regulating surfaces 23A of each guide wall 23 that face each pole accommodating groove 24A from both sides in the rotation direction. As a result, each pole 30 is supported by the guide 20 so that it can only move radially inward and outward along each regulating surface 23A.

[0042] Specifically, when each pole 30 is set in each pole accommodating groove 24A, its main body surface portion 30A is set in a state in which it abuts against the main body plate 21 of the guide 20 in the axial direction. As a result, each pole 30 is set in a state in which the internal teeth 12A of the cylindrical portion 12 of the ratchet 10 set in the cylindrical portion 22 of the guide 20 face radially to the radially outer position of its main body surface portion 30A. The offset surface portion 30B of each pole 30 is set in a state in which it is spaced apart from the main body plate 21 of the guide 20 in the axial direction.

[0043] 4, external teeth 31 with their tooth surfaces facing radially outward are formed continuously over the entire rotational range on the outer peripheral surface of the main body surface portion 30A of each pole 30. The outer peripheral surface of each pole 30 on which these external teeth 31 are formed is formed into a convex curved surface shape that curves along the inner peripheral surface of the cylindrical portion 12 on which the internal teeth 12A of the ratchet 10 described above are formed.

[0044] The external teeth 31 of each pawl 30 are shaped so that the tooth surfaces are arranged at equal intervals at a pitch of 2 degrees in the rotational direction, similar to the meshing internal teeth 12A of the ratchet 10. With the above configuration, as shown in Fig. 8, each pawl 30 is pressed into the internal teeth 12A of the ratchet 10 from the radially inner side, causing the external teeth 31 to mesh with the internal teeth 12A.

[0045] A rotating cam 40 (described later) set in the center of the guide 20 is set in a radially opposing manner in the inner peripheral region of the main body surface portion 30A of each pole 30. With this setting, each pole 30 is provided such that each main body surface portion 30A faces the rotating cam 40 in the radial direction, and each offset surface portion 30B faces the rotating cam 40 in the axial direction.

[0046] As shown in Fig. 4, the main body surface portion 30A of each pole 30 has an inner peripheral surface formed with a pressed surface portion 32 having an uneven shape that is pressed from the radially inner side by the rotation of the rotating cam 40. In addition, as shown in Fig. 5, the offset surface portion 30B of each pole 30 has a retraction hole 33 formed to penetrate the middle portion in the axial direction, into which retraction pins 42 formed at three positions in the rotation direction of the rotating cam 40 and protruding in the axial direction are inserted.

[0047] 8, when the rotating cam 40 is rotated counterclockwise in the drawing by the biasing force of a lock spring 50 (described later), the pressed surface portions 32 of the pawls 30 are pressed from the radially inner side by the corresponding concave-convex pressing portions 44 formed on the outer peripheral surface of the rotating cam 40. As a result, the external teeth 31 of the pawls 30 are pressed against the internal teeth 12A of the ratchet 10 to engage with them, and are maintained in that state.

[0048] This meshing results in each pawl 30 being integrally coupled to the ratchet 10 in the rotational direction. As a result, relative rotation between the ratchet 10 and the guide 20 via each pawl 30 is locked.

[0049] 9, when the rotating cam 40 is rotated clockwise against the biasing force of the lock spring 50 by operating the reclining lever 5, the retraction holes 33 of each of the pawls 30 are retracted radially inward by the corresponding retraction pins 42 of the rotating cam 40. As a result, the external teeth 31 of each of the pawls 30 are disengaged from the internal teeth 12A of the ratchet 10 and are maintained in that state. This releases the rotational lock between the ratchet 10 and the guide 20.

[0050] "Rotating Cam 40" The rotating cam 40 is made of a single metal plate-like member cut into a roughly disc-like shape. The rotating cam 40 has a shape with roughly the same plate thickness as each pole 30, and is configured with several locations that have been half-punched in the plate thickness direction (axial direction). The rotating cam 40 is set in a state where it is housed in the cam housing groove 24B formed on the main body plate 21 of the guide 20.

[0051] The rotating cam 40 is set so as to be sandwiched in the axial direction between the main body plate 21 of the guide 20 and the offset surface portion 30B of each pole 30. As a result, the rotating cam 40 is set in a state in which the pressed surface portion 32, which is the inner peripheral surface portion of the main body surface portion 30A of each pole 30, is located radially outward of the rotating cam 40.

[0052] As shown in Fig. 5, a through-hole 41 is formed in the center of the rotating cam 40 (a position on the rotation center C), through which the aforementioned operating pin 5A is inserted axially from the left side of the figure and integrally connected in the rotational direction. The operating pin 5A is inserted axially through the through-hole 41 of the rotating cam 40, and its tip is integrally connected to the reclining lever 5 described above in Fig. 1. With this assembly, the operating pin 5A rotates the rotating cam 40 integrally as the reclining lever 5 is pulled up.

[0053] The operating pin 5A is integrally connected to the operating pin 5A inserted into the other recliner 4 described above in Figure 1 via a connecting rod 5B. As a result, when the reclining lever 5 is pulled up, both operating pins 5A are rotated simultaneously, and the rotating cams 40 of both recliners 4 are rotated simultaneously.

[0054] As shown in Fig. 4, the rotating cam 40 is formed in a generally disk shape that is slightly larger than the accommodation hole 21A formed in the center (position on the rotation center C) of the guide 20. Two hook pins 43 that protrude axially toward the interior of the accommodation hole 21A are formed on the outer surface of the rotating cam 40 that faces the accommodation hole 21A of the guide 20. As shown in Fig. 6, an inner end 51 of a lock spring 50 is hooked between these hook pins 43 and fixed thereto.

[0055] 5, on the inner surface of the rotating cam 40 that faces the offset surface portion 30B of each pole 30 in the axial direction, a retraction pin 42 is formed to protrude in the axial direction and to be fitted into the retraction hole 33 of each pole 30. The rotating cam 40 is assembled to the guide 20 in a state where it is elastically supported via a lock spring 50 as follows.

[0056] First, the rotating cam 40 is set in the cam accommodating groove 24B of the guide 20. Next, as shown in Fig. 6, the lock spring 50 is assembled into the accommodating hole 21A of the guide 20, with its inner end 51 hooked between the hook pins 43 of the rotating cam 40 and its outer end 52 hooked into the latch hole 21Aa extending from the accommodating hole 21A of the guide 20. In this way, the rotating cam 40 is assembled to the guide 20 in a state where it is elastically supported via the lock spring 50.

[0057] With the above assembly, the rotating cam 40 is constantly biased by the lock spring 50 to rotate in the counterclockwise direction shown in Figure 8 relative to the guide 20. Due to this rotational bias, the rotating cam 40 normally presses the pressed surface portion 32 of each pawl 30 from the radially inner side by each pressing portion 44 that bulges out from multiple locations on the outer circumferential surface of the rotating cam 40 in the rotational direction, thereby maintaining each pawl 30 in a state of meshing with the internal teeth 12A of the ratchet 10.

[0058] 9, the rotating cam 40 is rotated clockwise via the operating pin 5A when the reclining lever 5 is pulled up. As a result, the rotating cam 40 pulls each of the poles 30 radially inward via the retraction pins 42 inserted into the retraction holes 33 of the poles 30, thereby disengaging them from the meshed state with the internal teeth 12A of the ratchet 10.

[0059] Outer Ring 60 As shown in Figures 4 and 5, the outer ring 60 is made of a single thin metal plate member punched into a ring plate shape. The outer peripheral edge of the outer ring 60 is drawn into a cylindrical shape that protrudes in the axial direction, thereby forming an approximately cylindrical shape with a flange portion 62 that serves as a hollow disk-shaped seat. Specifically, the outer ring 60 is configured to have a hollow disk-shaped flange portion 62 that faces straight in the axial direction, and a connecting portion 61 that protrudes in an approximately cylindrical shape in the axial direction from the outer peripheral edge of the flange portion 62.

[0060] Specifically, the outer peripheral edge of the outer ring 60 is formed into a shape that is squeezed out to protrude in two steps in the axial direction into a stepped cylindrical shape, whereby the squeezed outer cylindrical portion is formed as a substantially cylindrical joint portion 61, and the inner cylindrical portion is formed as a stepped portion 63 that connects the joint portion 61 and the flange portion 62 in a stepped manner.

[0061] The outer ring 60 is attached as follows, spanning the outer peripheries of the ratchet 10 and the guide 20, and holds them in a state where they cannot come off in the axial direction. First, the three poles 30, the rotating cam 40, and the lock spring 50 are set in the guide 20. Next, the ratchet 10 is assembled to the guide 20, and these are set inside the cylinder of the outer ring 60.

[0062] 6, the axially protruding tip of the connecting portion 61 is crimped over the entire circumference onto the outer surface of the cylindrical portion 22 of the guide 20 (crimped portion 61A). As a result, the connecting portion 61 of the outer ring 60 is integrally connected to the cylindrical portion 22 of the guide 20. The flange portion 62 is also set in a state in which it fits over the entire circumference of the ratchet 10 from the outside in the axial direction. As a result, the outer ring 60 is attached so as to straddle the outer peripheries of the ratchet 10 and the guide 20, and holds them in a state in which they are prevented from coming off in the axial direction.

[0063] Rockspring 50 6, lock spring 50 is a spiral spring. Specifically, lock spring 50 has an inner end 51 that is hooked onto rotating cam 40, an outer end 52 that is hooked into hook hole 21Aa that extends from accommodation hole 21A of guide 20, and a winding portion 53 that extends in a spiral shape from inner end 51 toward outer end 52.

[0064] The inner end 51 is bent radially inward from the inner end of the winding portion 53. The inner end 51 is inserted from the outside in the axial direction between two hook pins 43 formed on the rotating cam 40 and hooked thereon, so that the inner end 51 is hooked integrally with the rotating cam 40 in the rotational direction.

[0065] The outer end 52 is bent radially outward from the outer end of the wound portion 53. The outer end 52 is inserted from the outside in the axial direction into a hooking hole 21Aa that extends radially outward from the accommodation hole 21A of the guide 20, and is hooked thereto so as to be integral with the guide 20 in the counterclockwise rotation direction in the drawing.

[0066] The wound portion 53 is formed in a spiral shape extending clockwise from the inner end portion 51 for a length of one and a half to two revolutions in the drawing. The wound portion 53 is accommodated in the accommodation hole 21A in a wound and tightened state to have an outer diameter slightly smaller than that of the accommodation hole 21A of the guide 20, because the outer end portion 52 of the lock spring 50 is engaged with the engagement hole 21Aa in a state in which the wound portion 53 is engaged with the accommodation hole 21Aa in a state in which the outer end portion 52 of the lock spring 50 is twisted in the winding and tightening direction.

[0067] However, the outer peripheral surface (outermost winding surface) of the winding portion 53 is sandwiched from the outside in the radial direction by reduced diameter portions 21Ab that bulge out from two locations in the rotation direction on the inner peripheral surface of the accommodation hole 21A. The reduced diameter portions 21Ab are formed at two positions in the rotation direction that sandwich the rotation center C of the guide 20.

[0068] Specifically, the reduced diameter portion 21Ab is composed of two points: a first reduced diameter portion B1 that abuts against the radially outer side of the corner where the outer end 52 of the winding portion 53 is bent back, and a second reduced diameter portion B2 that is formed at a position that faces the first reduced diameter portion B1 in the radial direction across the rotation center C. The first reduced diameter portion B1 and the second reduced diameter portion B2 are each configured to be pressed against the outer peripheral surface of the winding portion 53 by a resilient force exerted between the inner end 51 and the outer end 52 of the winding portion 53 when the rotating cam 40 is rotated by the rotational bias of the lock spring 50 to a lock position where each pawl 30 (see FIG. 8) is engaged with the ratchet 10 (initial state).

[0069] The pressing restricts radial outward deflection of the winding region of the winding portion 53 sandwiched between the first reduced diameter portion B1 and the second reduced diameter portion B2. However, the winding region of the winding portion 53 from the point of contact with the second reduced diameter portion B2 to the inner end 51 is not restricted as described above, and is therefore allowed to deflect radially outward. Therefore, in this region, the winding portion 53 can appropriately urge the rotating cam 40 to rotate in the lock rotation direction.

[0070] As described above, the lock spring 50 is configured to be pressed and sandwiched between the first reduced diameter portion B1 and the second reduced diameter portion B2 of the guide 20, making it difficult for the lock spring 50 to come axially out of the accommodation hole 21A of the guide 20. Therefore, when the recliner 4 is transported as an assembly, the lock spring 50 is appropriately prevented from coming out of the accommodation hole 21A and falling out due to vibration or the like. As a result, when the guide 20 of the recliner 4 is welded to the reclining plate 3F described above in Figure 2 after transportation, the step of inspecting whether the lock spring 50 has come out can be omitted.

[0071] The lock spring 50 is set in the accommodation hole 21A of the guide 20 so as to be completely contained within the hole 21A and not to protrude outward in the axial direction (see FIG. 7). In other words, the outer axial portion of the lock spring 50 is located within the accommodation hole 21A of the guide 20. With this configuration, the lock spring 50 can efficiently apply a rotational biasing force to the rotating cam 40 without causing significant friction with the reclining plate 3F described above in FIG. 2. Therefore, the lock spring 50, which is provided within the accommodation hole 21A so as not to protrude in the axial direction as described above, can be appropriately held by the first reduced diameter portion B1 and the second reduced diameter portion B2 provided on the guide 20 so as not to protrude outward in the axial direction from the accommodation hole 21A.

[0072] 6, the reduced diameter portion 21Ab is arranged so that the first reduced diameter portion B1 (corresponding to the "outermost portion" of the present invention), which is abutted against the portion closest to the outer end 52 of the wound portion 53, abuts against the corner where the outer end 52 of the wound portion 53 is bent back. This allows the first reduced diameter portion B1 and the opposing second reduced diameter portion B2 to be positioned closer to the outer end 52 of the wound portion 53. As a result, a long effective flexible length (the winding region from the point of contact with the second reduced diameter portion B2 to the inner end 51) can be ensured, over which the wound portion 53 is allowed to bend.

[0073] To summarize the above, the recliner 4 according to this embodiment has the following configuration: Note that the reference numerals in parentheses below correspond to the respective components shown in the above embodiment.

[0074] That is, the vehicle seat reclining device (4) has a ratchet (10) and a guide (20) that are axially assembled so as to be rotatable relative to each other, a rotating cam (40) that is rotatably assembled to the guide (20), a pawl (30) that is assembled to the guide (20) and that engages with the ratchet (10) when the rotating cam (40) rotates in one direction to lock the rotation, and a lock spring (50) consisting of a spiral spring that urges the rotating cam (40) to rotate in the one direction relative to the guide (20).

[0075] The guide (20) has a receiving hole (21A) that receives the lock spring (50) in the axial direction, a latching hole (21Aa) that extends from the receiving hole (21A) and latches the outer end (52) of the lock spring (50), and a reduced-diameter portion (21Ab) formed by reducing the diameter of a portion of the receiving hole (21A) so as to abut from the outside in the radial direction against a winding portion (53) of the lock spring (50) that extends spirally from the inner end (51) that is latched on the rotating cam (40) toward the outer end (52). In a locked state in which the pawl (30) is engaged with the ratchet (10), the reduced-diameter portion (21Ab) abuts against the winding portion (53) from multiple points in the rotational direction, sandwiching it in the radial direction.

[0076] According to the above configuration, the reduced diameter portion (21Ab) of the guide (20) is brought into contact with the wound portion (53) of the lock spring (50) so as to sandwich the wound portion (53) in the radial direction, which makes it difficult for the wound portion (53) to shift axially relative to the guide (20). As a result, it is possible to appropriately prevent the lock spring (50) from falling out of the receiving hole (21A).

[0077] Furthermore, the reduced diameter portions 21Ab are provided at two positions in the rotation direction on either side of the rotation center C of the guide 20. With this configuration, the number of contact points of the reduced diameter portions 21Ab can be minimized. This ensures that the effective flexible length of the inner end portion 51 of the winding portion 53 of the lock spring 50 can be increased even when pressed and pinched by the reduced diameter portions 21Ab.

[0078] Furthermore, the outermost portion B1 of the reduced diameter portion 21Ab, which is in contact with the portion closest to the outer end 52 of the wound portion 53, is positioned to contact the corner where the outer end 52 of the wound portion 53 is bent back. According to the above configuration, the reduced diameter portion 21Ab can be positioned closer to the outer end 52 of the wound portion 53. This ensures that the effective flexible length of the inner end 51 side of the wound portion 53, which can bend even when pressed and pinched by the reduced diameter portion 21Ab, is longer.

[0079] In addition, the outer axial portion of the lock spring (50) is located within the receiving hole (21A). According to the above configuration, the lock spring (50) is prevented from falling out and the lock spring (50) is appropriately held in a state in which it does not protrude from the receiving hole (21A).

[0080] (Second embodiment) Next, the configuration of a recliner 4 according to a second embodiment of the present invention will be described with reference to Figure 10. In this embodiment, recliner 4 has reduced diameter portions 21Ac that bulge out from the inner circumferential surface of accommodation hole 21A and sandwich wound portion 53 of lock spring 50 from the radially outer side. The reduced diameter portions 21Ac bulge out from three locations in the rotational direction.

[0081] Specifically, reduced diameter portion 21Ac is composed of three points: a first reduced diameter portion C1 (corresponding to the "outermost point" of the present invention) that abuts from the radial outside against the corner where outer end 52 of winding portion 53 is bent back, and a second reduced diameter portion C2 and a third reduced diameter portion C3 that are arranged separately at positions on either side of an extension of a line segment connecting first reduced diameter portion C1 and center of rotation C. Third reduced diameter portion C3 is the portion of reduced diameter portion 21Ac that abuts at a position closest to inner end 51 of winding portion 53 in the rotational direction. Second reduced diameter portion C2 is located between third reduced diameter portion C3 and first reduced diameter portion C1.

[0082] The first reduced diameter portion C1, the second reduced diameter portion C2, and the third reduced diameter portion C3 are each configured to be pressed against the outer peripheral surface of the winding portion 53 by the elastic force exerted between the inner end portion 51 and the outer end portion 52 of the winding portion 53 when the rotating cam 40 has rotated to the locked position due to the rotational force of the lock spring 50 (initial state).

[0083] The above-described pressing restricts radial outward deflection of the winding region of the winding portion 53, which is sandwiched between the first reduced diameter portion C1, the second reduced diameter portion C2, and the third reduced diameter portion C3. However, the winding region of the winding portion 53 from the point of contact with the third reduced diameter portion C3 to the inner end 51 is not restricted in this manner, and is therefore allowed to deflect radially outward. Therefore, in this region, the winding portion 53 can appropriately urge the rotating cam 40 to rotate in the lock rotation direction.

[0084] The configuration other than the above is substantially the same as the configuration shown in the first embodiment, so the same components as those shown in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0085] To summarize the above, the recliner 4 according to this embodiment has the following configuration: Note that the reference numerals in parentheses below correspond to the respective components shown in the above embodiment.

[0086] That is, the guide 20 has a reduced diameter portion 21Ac formed by reducing the diameter of a part of the receiving hole 21A so as to abut from the outside in the radial direction against the winding portion 53 extending spirally from the inner end 51 to the outer end 52 of the lock spring 50. In a locked state in which the pawl 30 is engaged with the ratchet 10, the reduced diameter portion 21Ac abuts against the winding portion 53 in a pinching manner in the radial direction from multiple points in the rotational direction.

[0087] According to the above configuration, the reduced diameter portion (21Ac) of the guide (20) is brought into contact with the wound portion (53) of the lock spring (50) so as to sandwich the wound portion (53) in the radial direction, which makes it difficult for the wound portion (53) to shift axially relative to the guide (20). As a result, it is possible to appropriately prevent the lock spring (50) from falling out of the receiving hole (21A).

[0088] Furthermore, the outermost portion C1 of the reduced diameter portion 21Ac, which abuts against the portion closest to the outer end 52 of the wound portion 53, is positioned to abut against the corner where the outer end 52 of the wound portion 53 is bent back. According to the above configuration, the reduced diameter portion 21Ac can be positioned closer to the outer end 52 of the wound portion 53. This ensures that the effective flexible length of the inner end 51 side of the wound portion 53, which can bend even when pressed and pinched by the reduced diameter portion 21Ac, is longer.

[0089] (Third embodiment) Next, the configuration of a recliner 4 according to a third embodiment of the present invention will be described with reference to Figure 11. Recliner 4 according to this embodiment is configured such that reduced diameter portion 21Ad bulges out from the inner circumferential surface of accommodation hole 21A and contacts winding portion 53 of lock spring 50 from the outside in the radial direction, in a sandwiched manner, so as to bulge outward to contact the outer circumferential surface of winding portion 53 in a planar manner over most of the area in the rotational direction of the outer circumferential surface (the outermost winding surface) of winding portion 53.

[0090] Specifically, reduced diameter portion 21Ad is formed by bulging out most of the area of ​​the inner peripheral surface of accommodating hole 21A in a spiral curve along the outer peripheral surface (outermost winding surface) of winding portion 53. Reduced diameter portion 21Ad is configured to abut in a planar manner against the outer peripheral surface (outermost winding surface) of winding portion 53 over a wide area in the rotational direction from the corner where outer end 52 of winding portion 53 is bent back to the point where it overlaps with inner end 51 of winding portion 53 in the rotational direction.

[0091] Even with this configuration, the winding portion 53 is allowed to bend radially outward in a winding region of approximately one turn from the point where it leaves contact with the reduced diameter portion 21Ad (the outer peripheral surface portion where the arrangement in the rotation direction overlaps with the inner end portion 51) to the inner end portion 51. Therefore, in this region, the winding portion 53 can appropriately urge the rotating cam 40 to rotate in the lock rotation direction.

[0092] The configuration other than the above is substantially the same as the configuration shown in the first embodiment, so the same components as those shown in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0093] To summarize the above, the recliner 4 according to this embodiment has the following configuration: Note that the reference numerals in parentheses below correspond to the respective components shown in the above embodiment.

[0094] That is, the guide 20 has a reduced diameter portion 21Ad formed by reducing the diameter of a portion of the receiving hole 21A so as to abut from the outside in the radial direction against the winding portion 53 extending spirally from the inner end 51 to the outer end 52 of the lock spring 50. In a locked state in which the pawl 30 is engaged with the ratchet 10, the reduced diameter portion 21Ad abuts against the winding portion 53 in a pinching manner in the radial direction from multiple points in the rotational direction.

[0095] According to the above configuration, the reduced diameter portion (21Ad) of the guide (20) is fitted to the wound portion (53) of the lock spring (50) so as to sandwich it in the radial direction, making it difficult for the wound portion (53) to shift axially relative to the guide (20). As a result, it is possible to appropriately prevent the lock spring (50) from falling out of the receiving hole (21A).

[0096] Other Embodiments Although the present invention has been described above using three embodiments, the present invention can be embodied in various forms in addition to the above embodiments.

[0097] 1. The vehicle seat reclining device of the present invention can be applied to automobile seats as well as to seats used in a wide range of vehicles other than automobiles, such as trains, or other vehicles other than automobiles, such as airplanes and ships. Furthermore, the vehicle seat reclining device may be one that connects the seat back to the seat cushion so that the backrest angle can be adjusted, or one that connects the seat back to a base, such as a bracket, fixed to the vehicle body so that the backrest angle can be adjusted.

[0098] 2. The vehicle seat reclining device may be configured such that the ratchet is connected to a base that is fixed to the vehicle body, such as a seat cushion, and the guide is connected to the seat back.

[0099] 3. The poles that lock the relative rotation between the ratchet and the guide may be arranged in a row of two or four or more in the direction of rotation. The arrangement of the poles in the direction of rotation is not limited to being evenly spaced, and they may also be arranged offset.

[0100] 4. The reduced diameter portions that are applied to the winding portion of the lock spring from the radially outer side in a pinching manner may be arranged at four or more positions in the rotational direction. Furthermore, the reduced diameter portions may be formed by forming the receiving hole in a shape other than a perfect circle, such as an ellipse, polygon, or other irregular shape, and do not necessarily have to be formed as partially protruding protrusions as shown in the above embodiments 1 and 2.

[0101] The outermost point of the reduced diameter portion that is in contact with the part closest to the outer end of the winding portion may be positioned so that it is in contact with a point that is spaced in the rotational direction from the corner where the outer end of the winding portion is bent back, toward the inner end.

[0102] 5. The receiving hole may be configured to receive the lock spring so that it protrudes outward in the axial direction. [Explanation of symbols]

[0103] 1 sheet 2 seat backs 2F side frame 2Fa mating hole 2Fb through hole 3 seat cushions 3F Reclining plate 3Fa fitting hole 3Fb through hole 4 Reclining device for vehicle seats 5 Reclining lever 5A operation pin 5B connecting rod 6 Return spring 10 Ratchet 11 Main board 11A through hole 12 Cylindrical part 12A Internal teeth 13 Intermediate cylindrical section 14 Dowel 20 Guide 21 Main board 21A Receiving hole 21Aa latching hole 21Ab Reduced diameter part B1 First reduced diameter section (outermost point) B2 2nd reduced diameter section 21Ac Reduced diameter part C1 First reduced diameter section (outermost point) C2 2nd reduced diameter section C3 3rd reduced diameter section 21Ad Reduced diameter part 21B Dowel 22 Cylindrical part 23 Guide Wall 23A Regulatory aspects 23B Support surface 24A Pole accommodation groove 24B Cam receiving groove 30 Paul 30A Main body surface 30B offset surface 31 Outer teeth 32 Pressed surface 33 Inlet hole 40 rotation cam 41 Through hole 42 Retractable pin 43 Hook pin 44 Pressing part 50 Rock Spring 51 Inner end 52 Outer end 53 Winding section 60 outer ring 61 Joint 61A Crimping part 62 Flange 63 Step C Rotation center

Claims

1. A vehicle seat reclining device, a ratchet and a guide that are axially assembled so as to be rotatable relative to each other; a rotating cam rotatably mounted on the guide; a pawl assembled to the guide, which is engaged with the ratchet by unidirectional rotation of the rotary cam to lock rotation; a lock spring formed of a spiral spring that rotates the rotating cam relative to the guide in one direction, the guide has an accommodating hole that accommodates the lock spring in the axial direction, a hooking hole that extends from the accommodating hole and hooks the outer end of the lock spring, and a reduced diameter portion that is formed by reducing the diameter of a part of the accommodating hole so that the reduced diameter portion can be brought into contact from the outside in the radial direction with a winding portion of the lock spring that extends spirally from the inner end that hooks on the rotating cam toward the outer end, In a vehicle seat reclining device, when the pawl is in a locked state where it is engaged with the ratchet, the reduced diameter portion is brought into contact with the winding portion in a pinching manner in the radial direction from a plurality of positions in the rotational direction.

2. 2. The vehicle seat reclining device according to claim 1, The vehicle seat reclining device, wherein the reduced diameter portions are provided at two positions in the rotation direction on either side of the rotation center of the guide.

3. 3. The vehicle seat reclining device according to claim 1 or 2, A vehicle seat reclining device in which the outermost point of the reduced diameter portion that is in contact with the part closest to the outer end of the wound portion is positioned to be in contact with the corner of the bent portion where the outer end of the wound portion is bent back.

4. 3. The vehicle seat reclining device according to claim 1 or 2, A vehicle seat reclining device in which an axially outer portion of the lock spring is positioned within the accommodating hole.

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