JP2007144131A - Vehicle seat reclining device - Google Patents

Abstract

There is provided a vehicle seat reclining device capable of obtaining a suitable operational feeling while suppressing an increase in the number of parts.
A connecting shaft is fitted with a clearance to a cam 31 that restricts or allows rotation of each upper plate relative to a lower plate. The spring 33 is wound around the rotation axis O of each cam 31, and the one end 33a and the other end 33b are locked to the lower plate and the cam 31, respectively, to restrict the cam 31 from rotating with respect to the lower plate. Energize in the direction of rotation on the side. The spring 33 is a pressing force that presses the connecting shaft 34 so as to eliminate the play of the clearance of the fitting of the cam 31 and the connecting shaft 34 in the rotation direction on the side where the cam 31 restricts the rotation of the upper plate relative to the lower plate. It has a portion 33c.
[Selection] Figure 2

Description

  The present invention relates to a vehicle seat reclining device.

  Conventionally, various types of vehicle seat reclining devices for inclining a seat back with respect to a seat cushion have been proposed. Such a vehicle seat reclining device is provided with a lock mechanism for restricting the rotation of the seat back relative to the seat cushion on both the left and right sides of the seat, and by switching the operation (lock / unlock) of these lock mechanisms, The back can be adjusted and held at a required inclination angle suitable for passenger seating or the like.

  For example, Patent Document 1 includes a lower plate (7) and a spring (18) engaged with the connection shaft at one end and the other end of the connection shaft (17). By urging the cam (16) to the side where the teeth (13) of the upper plate (8) and the teeth (12) of the pole (11) mesh with each other via the connecting shaft by this spring, the seat cushion Rotation of the seat back is restricted. However, since this spring urges the cam via a connecting shaft provided for connecting a locking mechanism disposed on both the left and right sides of the seat, the left and right locking mechanisms are caused by, for example, distortion of the seat frame or the floor surface. If an assembly error occurs in the rotation direction, there is a possibility that even if one of the lock mechanisms can hold the above-described engagement, the other lock mechanism has an insufficient urging force and cannot maintain the engagement.

On the other hand, Patent Document 2 includes a spring (5) wound around a rotation axis of a cam (32) and having one end and the other end locked to a lower plate (1) and a groove (32f) of the cam, respectively. Depending on the connecting shaft (4), the spring biases the cam toward the side where the teeth (25a) of the upper plate (2) and the teeth (33a) of the pole (33) mesh with each other. Therefore, the rotation of the seat back relative to the seat cushion is restricted.
JP 2001-299489 A JP 2000-342368 A

  By the way, in Patent Document 2, a sufficient clearance capable of absorbing an assembly error in the rotational direction between the lock mechanisms on both the left and right sides is set in the fitting portion between the connection shaft and the cam, and is integrated with the connection shaft. In the operation lever (7) provided in (3), a play corresponding to the clearance occurs in the operation direction coinciding with the rotation direction described above. Therefore, the sense of moderation is lost in the operation of the operation lever, and the feeling of operation becomes worse. Further, for example, when the vehicle is running, the operation lever may rattle with the connecting shaft within the clearance range and generate an abnormal noise.

  In order to avoid the influence of such play of the operation lever, a spring is separately provided to urge the operation lever directly, or an elastic body is interposed in the fitting portion between the connecting shaft and the cam. Has also been proposed by the present applicant. However, in this case, the number of parts must be increased.

  An object of the present invention is to provide a vehicle seat reclining device capable of obtaining a suitable operational feeling while suppressing an increase in the number of parts.

  In order to solve the above problem, the invention according to claim 1 is a pair of lower plates held on either the seat cushion side or the seat back side, and is rotatably supported by the lower plates. A pair of upper plates held on the other side of the seat cushion side and the seat back side, a pair of cams that restrict or allow the rotation of the upper plates with respect to the lower plate with rotation, and clearance between the cams And a connecting shaft for integrally rotating the pair of cams so as to allow the upper plate to rotate relative to the lower plate when an operating force is input, and windings around the rotation shafts of the cams. And one end and the other end are locked to the lower plate and the cam, respectively, and the cam is opposed to the lower plate of the upper plate. In a vehicle seat reclining device having a pair of springs biased in the rotational direction on the side that restricts rotation, the spring is in a rotational direction on one side and is equivalent to the clearance of the fitting between the cam and the connecting shaft. The gist is to have a pressing part that presses the connecting shaft so as to eliminate play.

  According to this configuration, the connecting shaft for integrally rotating the pair of cams is fitted to the cam with a clearance in the direction so as to absorb an assembly error in the rotation direction. And the play of the clearance of the fitting of the cam and the connecting shaft is eliminated in the rotational direction on one side when the pressing portion of the spring presses the connecting shaft. Therefore, when the operating force is input to the connecting shaft so as to allow the upper plate to rotate with respect to the lower plate, the play for the clearance is eliminated, so that a favorable operational feeling can be obtained. . Further, since the pressing portion is formed by using the spring that urges the cam in the rotation direction on the side that restricts the rotation of the upper plate relative to the lower plate, an increase in the number of parts is suppressed. The

  According to a second aspect of the present invention, in the vehicle seat reclining device according to the first aspect, the pressing portion has a rotation direction on a side where the cam restricts rotation of the upper plate with respect to the lower plate, and The gist is to press the connecting shaft so as to eliminate the play of the clearance between the cam and the connecting shaft.

  According to a third aspect of the present invention, in the vehicle seat reclining device according to the second aspect, the cam has a projecting portion that receives the pressing force from the spring, with the other end of the spring being locked. The press portion is a bent portion that applies a pressing force to the connecting shaft at a position different from the position of the protruding portion where the other end of the spring is locked.

  According to a fourth aspect of the present invention, in the vehicle seat reclining device according to the second aspect, the cam has a projecting wall portion projecting in the axial direction having a fitting hole for fitting with the connecting shaft. The projecting wall portion is formed with a groove portion that opens to the fitting hole side and is engaged with the other end of the spring, and the pressing portion is a member other than the spring that is engaged with the groove portion. The gist is that the end is a tip portion that is introduced to the fitting hole side and presses the connecting shaft.

  According to each of the above-described configurations, the play of the clearance between the cam and the connecting shaft is caused by the pressing portion of the spring pressing the connecting shaft, so that the cam rotates the upper plate relative to the lower plate. It is eliminated in the direction of rotation on the side that restricts movement. Therefore, when the operating force is input to the connecting shaft so as to allow the upper plate to rotate with respect to the lower plate, the play for the clearance is eliminated, so that a favorable operational feeling can be obtained. . That is, at the initial stage of operation, an operation force for rotating the connecting shaft against the pressing force by the pressing portion of the spring is required, and thereafter, the cam together with the cam against the biasing force of the spring. An operation force for rotating the connecting shaft is required, and a moderate operation feeling can be obtained throughout the operation period.

  According to a fifth aspect of the present invention, in the vehicle seat reclining device according to the fourth aspect, the pressing portion presses the connecting shaft at an axial position where the cam and the connecting shaft are fitted. Is the gist.

  According to this configuration, the pressing portion presses the connecting shaft at a position in the axial direction in which the cam and the connecting shaft are fitted, for example, in the axial direction in which the cam and the connecting shaft are fitted. Compared with the case where the connecting shaft is pushed out of position, the axis of the connecting shaft is further stabilized.

  A sixth aspect of the present invention is the vehicle seat reclining device according to the third aspect, wherein the pressing portion is adjacent to the axial position where the cam and the connecting shaft are fitted in the axial direction. The gist is to press the connecting shaft at a position.

  According to this configuration, the pressing portion presses the connecting shaft at a position adjacent to the axial direction with respect to the axial position where the cam and the connecting shaft are fitted, for example, the cam and Compared to the case where the connecting shaft is displaced from the axial position where the connecting shaft is fitted and the connecting shaft is pressed, the axis of the connecting shaft is further stabilized.

  According to a seventh aspect of the present invention, in the vehicle seat reclining device according to the first aspect, the pressing portion has a rotation direction on a side where the cam allows the upper plate to rotate with respect to the lower plate, and The gist is to press the connecting shaft so as to eliminate the play of the clearance between the cam and the connecting shaft.

  According to an eighth aspect of the present invention, in the vehicle seat reclining device according to the seventh aspect, the cam has a protrusion to which the other end of the spring is locked, and the pressing portion is a member other than the spring. The gist of the present invention is a terminal portion that extends from the position of the projection with which the end is locked and applies a pressing force to the connecting shaft.

  According to each of the above-described configurations, the play of the clearance between the cam and the connecting shaft is caused by the pressing portion of the spring pressing the connecting shaft, so that the cam rotates the upper plate relative to the lower plate. It is eliminated in the direction of rotation that allows movement. Therefore, when the operating force is input to the connecting shaft so as to allow the upper plate to rotate with respect to the lower plate, the play for the clearance is eliminated, so that a favorable operational feeling can be obtained. . That is, the play corresponding to the clearance between the cam and the connecting shaft is eliminated in advance in the rotation direction of the cam allowing the upper plate to rotate with respect to the lower plate. When the input of the operation force is started, the cam immediately rotates in the rotation direction of the upper plate that allows the upper plate to rotate with respect to the lower plate, and the permission of the rotation starts. At this time, since the operating force for rotating the connecting shaft together with the cam gradually increases against the biasing force of the spring, a direct operational feeling without an operation dead zone is obtained.

  According to the first to eighth aspects of the present invention, it is possible to provide a vehicle seat reclining device capable of obtaining a suitable operational feeling while suppressing an increase in the number of components.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
1 and 2 are an exploded perspective view and a front view showing a vehicle seat reclining device mounted on a vehicle such as an automobile. FIG. 3 is a cross-sectional view taken along line AA in FIG. The vehicle seat reclining device basically includes a pair of the structures shown in FIGS. 1 to 3 in the width direction of the vehicle seat. Here, the structure is arranged on the right side toward the front of the vehicle. Shown as a representative. Therefore, the following description will be made on behalf of the structure disposed on the right side as common to the structures disposed on each side.

  As shown in FIG. 3, the vehicle seat reclining device includes a seat cushion frame 11 made of a metal plate that forms the skeleton of the seat cushion, and the seat cushion frame 11 includes a metal plate that forms the skeleton of the seat back. A seat back frame 12 is connected via a lock mechanism 20 so as to be rotatable about a rotation axis O. The lock mechanism 20 is for switching between a state in which the rotation of the seat back frame 12 with respect to the seat cushion frame 11 is restricted and a state in which the seat back frame 12 is permitted, and basically the rotation of the seat back frame 12 with respect to the seat cushion frame 11. Maintains a dynamic regulation state.

Next, the lock mechanism 20 will be described.
The lower plate 21 fixed to the inner side surface of the seat cushion frame 11 by welding is formed by half blanking of a metal plate, and as shown in FIG. It is formed in a ring shape having 21a. The lower plate 21 is formed with a locking hole 21b that is continuous with the through hole 21a and is recessed radially outward.

  Further, the lower plate 21 is formed with a recess 22 that is circularly recessed on the opposite side of the seat cushion frame 11. And in this recessed part 22, the several (3) convex part 23 which protrudes from the bottom wall is formed for every predetermined angle. Each convex portion 23 includes two molded portions 23a and 23b divided in the circumferential direction, and has a side surface 23c that extends flat in the radial direction so as to be parallel to the adjacent convex portions 23. is doing. The lower plate 21 forms a guide groove 24 extending in the radial direction between the adjacent side surfaces 23c.

  As shown in FIGS. 1 and 3, the upper plate 26 fixed to the inner surface of the seat back frame 12 by welding is formed by half-cutting a metal plate and is equivalent to the inner diameter of the recess 22. And a ring shape having a shaft insertion hole 26a at the center. The upper plate 26 is mounted such that its outer peripheral surface is in sliding contact with the inner peripheral surface of the recess 22. That is, the upper plate 26 is pivotally supported by the lower plate 21. Accordingly, the seat back frame 12 is rotatably connected to the seat cushion frame 11 via the lower plate 21 and the upper plate 26 (lock mechanism 20).

  As shown in FIG. 3, the upper plate 26 is formed with a first recess 27 that is circularly recessed on the opposite side (lower plate 21 side) of the seat back frame 12. An inner tooth 27 a is formed on the inner peripheral surface of the first recess 27. In a state where the upper plate 26 is mounted on the lower plate 21, the internal teeth 27 a face the radial direction of the guide groove 24. The first recess 27 is formed with a second recess 28 having an inner diameter that is smaller than the inner diameter and concentrically recessed.

  In a state where the upper plate 26 is mounted on the lower plate 21, a ring-shaped holder 29 made of a metal plate is mounted on these outer peripheral portions, and the lower plate 21 and the upper plate 26 are relative to each other by the holder 29. It is prevented from coming off in the axial direction while being allowed to rotate.

  In a state where the upper plate 26 is mounted on the lower plate 21, a cam 31 formed by half punching of a metal plate rotates in the internal space formed by the concave portion 22 and the first and second concave portions 27 and 28. The shaft O is accommodated so as to be rotatable. As shown in FIG. 1, the cam 31 has a plurality of (three) cam portions 31a extending in the radial direction at predetermined angles, and each cam portion 31a has an upper plate 26 side parallel to the axial direction. A pin-like protrusion 31b is formed so as to protrude from the surface. Further, the cam 31 is formed with a fitting hole 31c having a flat cross-sectional shape (oval shape) that penetrates the central portion in the axial direction. Further, as shown in FIG. 3, the cam 31 is formed with a pin-like projecting portion 31 d that projects parallel to the axial direction toward the lower plate 21. In the state where the cam 31 is accommodated between the lower plate 21 and the upper plate 26 (internal space), the protruding portion 31d is the position of the intermediate portion between the through hole 21a and the fitting hole 31c in the radial direction. And it arrange | positions so that it may correspond with the position of the axial direction of the through-hole 21a (and locking hole 21b).

  As shown in FIG. 1, each guide groove 24 is provided with a pole 32 formed in a rectangular plate shape having a width slightly smaller than the width in the circumferential direction. The radial movement is guided by sliding contact with the side surface 23 c of the convex portion 23. In addition, external teeth 32a that mesh with the internal teeth 27a (see FIG. 3) of the upper plate 26 are formed at the tip of each pole 32, and the base end of each pole 32 penetrates in the thickness direction. A cam hole 32b is formed. The cam hole 32b is inclined with respect to the circumferential direction around the rotation axis O, and the pawl 32 is engaged with the cam hole 32b by inserting the projection 31b of the cam 31 therein.

  Further, as shown in FIG. 3, each pole 32 is provided with a step portion in the axial direction between the external teeth 32 a and the cam hole 32 b, and the end surface facing the radial direction of the step portion is a pole cam. A surface 32c is formed. The pole cam surface 32c extends so as to cross the side surface of the pole 32 and to have an inclination angle with respect to the pitch circle of the external teeth 32a. The pawl 32 is engaged with the pawl cam surface 32c when the tip end surface of the cam portion 31a comes into contact therewith.

  That is, when the cam 31 rotates to one side (clockwise direction in FIG. 1) in a state where the cam 31 and the pole 32 are accommodated between the lower plate 21 and the upper plate 26 (internal space), the pole 32 has a cam hole. When 32 b is pressed by the protrusion 31 b of the cam 31, it moves so as to be drawn in the radial direction along the guide groove 24. At this time, the engagement between the outer teeth 32 a of the pole 32 and the inner teeth 27 a of the upper plate 26 is released, so that the upper plate 26 can rotate with respect to the lower plate 21. And the rotation permissible state of the upper plate 26 with respect to the lower plate 21 is set.

  On the other hand, when the cam 31 rotates to the other side (counterclockwise direction in FIG. 1), the cam hole 32b of the pole 32 is pressed against the projection 31b of the cam 31, and the pole cam surface 32c is the front end surface of the cam portion 31a. When it is pressed, it moves so as to jump out in the radial direction along the guide groove 24. At this time, the outer teeth 32 a of the pole 32 and the inner teeth 27 a of the upper plate 26 are engaged with each other, and the upper plate 26 cannot rotate with respect to the lower plate 21. Then, the rotation restriction state of the upper plate 26 with respect to the lower plate 21 is set.

  A spring 33 is housed in the center of the lower plate 21, that is, on the inner peripheral side of the through-hole 21a. Ends 33 b are respectively engaged with the locking holes 21 b of the lower plate 21 and the protruding portions 31 d of the cam 31. The spring 33 is wound around the rotation axis O of the cam 31 so as to open the fitting hole 31c in the axial direction. The spring 33 is configured such that the cam 31 is rotated to the other side (counterclockwise direction in FIG. 1) with respect to the lower plate 21, that is, the rotation restriction state of the upper plate 26 with respect to the lower plate 21 is set. Energize to.

  Therefore, the cam 31 basically maintains the rotation restriction state of the upper plate 26 relative to the lower plate 21 and the rotation restriction state of the seat back frame 12 relative to the seat cushion frame 11 by the biasing force of the spring 33. . When the cam 31 rotates in the illustrated clockwise direction with respect to the lower plate 21 against the spring 33, the cam 31 switches to a state in which the upper plate 26 is allowed to rotate with respect to the lower plate 21.

  A connecting shaft 34 made of a metal rod, which is sequentially inserted into the through hole 21a of the lower plate 21 in which the spring 33 is accommodated, the fitting hole 31c of the cam 31 and the shaft insertion hole 26a of the upper plate 26, extends outward. And has a flange 34a that protrudes from the flange 34a on one side in the axial direction (lower plate 21 side) and is fitted into the fitting hole 31c with a clearance in the rotational direction (flat shape). Are integrally provided with a fitting portion 34b and a connecting portion 34c that is further provided on one side in the axial direction continuously to the fitting portion 34b. The connecting shaft 34 is positioned in the axial direction between the flange 34a adjacent to the spring 33 by attaching an annular push nut 35 to the tip portion protruding from the shaft insertion hole 26a. . At this time, the fitting portion 34b is arranged in accordance with the position of the fitting hole 31c in the axial direction (see FIG. 3), and is connected so as to rotate integrally with the cam 31. The spring 33 is arranged in accordance with the axial position where the cam 31 and the connecting shaft 34 are fitted.

  In addition, the connecting shaft 34 is connected at the connecting portion 34c so as to rotate integrally with the corresponding connecting portion 34c of the opposite connecting shaft 34 forming a pair. Therefore, when the connecting shafts 34 on both sides rotate in conjunction with each other, the cams 31 on both sides that fit in the fitting portions 34b of the corresponding connecting shafts 34 and the fitting holes 31c also rotate together. The connecting shaft 34 that integrally rotates the pair of cams 31 is fitted in the cam 31 with a clearance in the rotational direction so as to absorb an assembly error between the lock mechanisms 20 on both sides. Because.

  Further, the connecting shaft 34 is integrally provided with a mounting portion 34d that protrudes from the flange 34a to the other side in the axial direction (opposite the lower plate 21), and is connected to the connecting shaft 34 on one side shown in FIG. The operation lever 36 is attached so that the attachment portion 34d is inserted therethrough and connected to the connection shaft 34 so as to rotate integrally therewith. The operating lever 36 is configured to operate the cam 31 on both sides via the connecting shaft 34 against the spring 33 in the clockwise direction in the figure with respect to the lower plate 21, that is, the upper plate 26 with respect to the lower plate 21. This is for inputting an operation force for switching to the rotation-permitted state.

  Here, the spring 33 of the present embodiment will be further described. As shown in FIG. 2, the spring 33 is wound in the illustrated counterclockwise direction from the inner peripheral side toward the outer peripheral side. The one end 33a disposed on the outer peripheral side is bent radially outward and inserted and locked into the locking hole 21b, and the other end 33b disposed on the inner peripheral side is radially outward. It bends and is brought into pressure contact with the protruding portion 31d from the rotating shaft O side and is locked thereto. The spring 33 has a bent portion 33c as a pressing portion that elastically presses a corner portion of the fitting portion 34b having an oval shape in the vicinity of the protruding portion 31d in the counterclockwise direction. Have. As described above, the cam 31 (fitting hole 31c) and the connecting shaft 34 (fitting portion 34b) have a fitting clearance in the rotational direction, and the rotary shaft O is interposed between them. There is a play angle θ centered at. The bent portion 33c is connected in the counterclockwise direction shown in the figure so as to eliminate the play angle θ corresponding to the clearance, that is, the rotation direction on the side where the cam 31 restricts the rotation of the upper plate 26 relative to the lower plate 21. The shaft 34 is pressed. It goes without saying that the bent portion 33c presses the connecting shaft 34 at a position adjacent to the axial direction where the cam 31 and the connecting shaft 34 are fitted in the axial direction.

  More specifically, in the vicinity of the rotation axis O, the pressing force of the spring 33 is generated at two points of the other end 33b and the bent portion 33c. The pressing force to the cam 31 (projecting portion 31d) at the other end 33b is p, and the pressing force to the connecting shaft 34 (fitting portion 34b) at the bent portion 33c is equal to the magnitude of the pressing force p and in the opposite direction. Assuming −p, the distance between these two points is l, and the generated torque T of the spring 33 acting on the cam 31 is T = p × l.

  Further, since the direction of the pressing force −p has an offset of an eccentricity e with respect to the rotation axis O, a rotation torque of −p × e is applied to the connection shaft 34, and the connection shaft 34 is applied to the cam 31. It is biased counterclockwise in the figure. As a result, the play angle θ corresponding to the clearance for fitting the cam 31 and the connecting shaft 34 is eliminated.

  In such a structure, in order to allow the upper plate 26 to rotate with respect to the lower plate 21, when the operating lever 36 is operated to input an operating force to the connecting shaft 34, the clearance angle θ corresponding to the clearance is set. By eliminating, a suitable operational feeling can be obtained. That is, at the initial stage of operation, an operation force for rotating the connecting shaft 34 against the pressing force by the bent portion 33c of the spring 33 is required, and thereafter, the operation force against the urging force of the spring 33 is required. Therefore, an operating force for rotating the connecting shaft 34 together with the cam 31 is required, and a moderate operating feeling can be obtained throughout the operating period.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In this embodiment, the play (play angle θ) corresponding to the clearance of the fitting between the cam 31 and the connecting shaft 34 is caused by the bending portion 33 c of the spring 33 pressing the connecting shaft 34. The cam 31 is eliminated in the rotation direction on the side that restricts the rotation of the upper plate 26 with respect to the lower plate 21. Accordingly, when an operating force is input to the connecting shaft 34 in order to allow the upper plate 26 to rotate with respect to the lower plate 21, the play for the clearance is eliminated, so that a suitable operational feeling is achieved. Can be obtained. The bent portion 33c is formed by using the spring 33 that urges the cam 31 in the rotation direction on the side that restricts the rotation of the upper plate 26 with respect to the lower plate 21. The increase in score can be suppressed.

  Furthermore, since the clearance for the clearance is eliminated, for example, when the vehicle is traveling, it is possible to prevent the operation lever 36 from rattling with the connecting shaft 34 and the cam 31 from generating abnormal noise. it can.

  (2) In the present embodiment, the bent portion 33c presses the connecting shaft 34 at a position adjacent to the axial direction where the cam 31 and the connecting shaft 34 are fitted. Thus, for example, the axis of the connecting shaft 34 can be further stabilized as compared with the case where the connecting shaft 34 is pressed out of position in the axial direction in which the cam 31 and the connecting shaft 34 are fitted.

  (3) In the present embodiment, the cross-sectional shape of the connecting shaft 34 (fitting portion 34b) is an oval shape, so that the contact position with the bent portion 33c can be easily ensured as compared to, for example, a serration shape. The bent portion 33c can press the connecting shaft 34 in a more stable state.

(4) In this embodiment, the assembly error of the lock mechanisms 20 on both sides of the pair can be absorbed using the clearance of the fitting between the cam 31 and the connecting shaft 34.
(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In addition, since 2nd Embodiment is the structure which changed the cancellation | release aspect of the play for the clearance clearance of the cam and connection shaft in 1st Embodiment, the detailed description is abbreviate | omitted about the same part. .

  4 and 5 are an exploded perspective view and a front view showing a vehicle seat reclining device mounted on a vehicle such as an automobile. FIG. 6 is a cross-sectional view taken along line BB in FIG. As shown in FIG. 6, in the lock mechanism 40 of the present embodiment, a metal cam 41 is accommodated between the lower plate 21 and the upper plate 26 (internal space) so as to be rotatable around the rotation axis O. Yes. The cam 41 includes a protruding wall portion 41a having an outer diameter smaller than the inner diameter of the through hole 21a and protruding in a columnar shape on one axial side (lower plate 21 side). 41a is formed with a fitting hole 41b having a flat circular cross section (oval shape) that penetrates the central portion thereof in the axial direction. The fitting portion 34b of the connecting shaft 34 is fitted in the fitting hole 41b with a clearance in the rotation direction.

  Further, as shown in FIG. 5, the protruding wall portion 41a is formed with a groove portion 41c that extends in parallel with the radial direction and opens toward the fitting hole 41b in a manner that is offset from the rotation axis O by the eccentric amount e. ing. As shown in FIG. 6, in the state where the cam 41 is accommodated between the lower plate 21 and the upper plate 26 (internal space), the groove portion 41c (projecting wall portion 41a) is formed in the through hole 21a (and the engagement portion). It is arranged to coincide with the axial position of the stop hole 21b).

  As shown in FIG. 5, a spring 42 is housed in the central portion of the lower plate 21, that is, on the inner peripheral side of the through hole 21a. At the same time, one end 42a and the other end 42b are engaged with the engaging hole 21b of the lower plate 21 and the groove 41c of the cam 41, respectively. The spring 42 is wound around the rotation axis O of the cam 41, that is, on the outer peripheral side of the protruding wall portion 41a so as to open the fitting hole 41b in the axial direction. This spring 42 is set so that the cam 41 rotates in the other side (counterclockwise direction in FIG. 4) with respect to the lower plate 21, that is, the side on which the rotation restriction state of the upper plate 26 relative to the lower plate 21 is set. Energize to.

  Therefore, the cam 41 basically holds the rotation restriction state of the upper plate 26 relative to the lower plate 21 by the biasing force of the spring 42 and holds the rotation restriction state of the seat back frame 12 relative to the seat cushion frame 11. . When the cam 41 rotates in the illustrated clockwise direction with respect to the lower plate 21 against the spring 42, the cam 41 switches to a state in which the upper plate 26 is allowed to rotate with respect to the lower plate 21.

  Here, the spring 42 of the present embodiment will be further described. As shown in FIG. 5, the spring 42 is wound in the illustrated counterclockwise direction from the inner peripheral side toward the outer peripheral side. The one end 42a arranged on the outer peripheral side is bent radially outward and inserted and locked into the locking hole 21b, and the other end 42b arranged on the inner peripheral side is radially inward. It bends and is inserted and locked into the groove 41c.

  At this time, the other end 42b introduced to the fitting hole 41b side through the groove 41c protrudes to the fitting hole 41b side and elastically presses the corner of the fitting portion 34b having an oval shape. It has the front-end | tip part 42c as a press part to perform. Accordingly, a rotational torque is applied to the connecting shaft 34 by applying a pressing force that is offset from the rotating shaft O by the amount of eccentricity e, and the connecting shaft 34 is urged against the cam 41 in the illustrated counterclockwise direction. . As described above, there is a fitting clearance in the rotational direction between the cam 41 (fitting hole 41b) and the connecting shaft 34 (fitting portion 34b). There is a play angle centered around. The distal end portion 42c is connected to the connecting shaft 34 in the counterclockwise direction shown in the drawing so as to eliminate the play angle corresponding to the clearance, that is, the rotation direction on the side where the cam 41 restricts the rotation of the upper plate 26 relative to the lower plate 21. Press. Needless to say, the distal end portion 42c presses the connecting shaft 34 at an axial position where the cam 41 and the connecting shaft 34 are fitted.

As described above in detail, according to the present embodiment, the following effects can be obtained in addition to the effects (1), (3), and (4) in the first embodiment.
(1) In the present embodiment, the tip 42c presses the connecting shaft 34 at an axial position where the cam 41 and the connecting shaft 34 are fitted, for example, the cam 41 and the connecting shaft 34. Compared to the case where the connecting shaft 34 is pressed out of position in the axial direction in which the fitting shaft is fitted, the axis of the connecting shaft 34 can be further stabilized.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In addition, since the third embodiment has a configuration in which the play canceling portion corresponding to the clearance between the cam and the coupling shaft in the first embodiment is changed, the same reference numerals are given to the same parts. Detailed description thereof is omitted.

  7 and 8 are front views showing a part of the lock mechanism provided in the vehicle seat reclining device according to the present embodiment. In the lock mechanism of the present embodiment, the metal cam 51 accommodated between the lower plate 21 and the upper plate 26 (internal space) so as to be rotatable about the rotation axis O is as shown in FIG. Instead of the projecting portion 31d, a pair of pin-shaped projections 51a and 51b projecting in parallel with the axial direction are provided. These protrusions 51a and 51b are arranged at intervals.

  The spring 52 accommodated in the central portion of the lower plate 21 is formed by spirally winding a wire having a substantially rectangular constant cross section, and is wound in the illustrated counterclockwise direction from the inner peripheral side toward the outer peripheral side. Has been. Then, one end 52a and the other end 52b of the spring 52 are engaged with the engagement hole 21b (see FIG. 2) of the lower plate 21 and the projections 51a and 51b of the cam 51, respectively.

  That is, the linear other end 52b formed by bending the distal end portion on the inner peripheral side of the spring 52 is positioned on the protrusion 51a on the inner peripheral side of the base end, and is positioned on the protrusion 51b on the outer peripheral side of the intermediate portion. Therefore, it is inserted between these protrusions 51a and 51b. The other end 52b extends from the position of the protrusion 51b to form a terminal portion 52c as a pressing portion. Although the spring 52 is basically wound around the rotation axis O of the cam 51 so as to open the fitting hole 31c in the axial direction, as shown in FIG. The part 52c covers a part of the outer peripheral side of the fitting hole 31c.

  The spring 52 urges the cam 51 in the rotation direction (arrow direction in the figure) on the side where the rotation restriction state of the upper plate 26 with respect to the lower plate 21 is set. Therefore, the cam 51 basically holds the rotation restriction state of the upper plate 26 relative to the lower plate 21 by the urging force of the spring 52 and holds the rotation restriction state of the seat back frame 12 relative to the seat cushion frame 11. . When the cam 51 rotates in the illustrated clockwise direction against the lower plate 21 against the spring 52, the cam 51 switches to a state in which the upper plate 26 is allowed to rotate with respect to the lower plate 21.

  As shown in FIG. 8, the terminal portion 52c covering a part on the outer peripheral side of the fitting hole 31c elastically presses a corner portion of the fitting portion 34b having an oval shape. Therefore, a rotational torque is applied to the connecting shaft 34 by applying a pressing force, and the connecting shaft 34 is urged to the cam 51 in the illustrated clockwise direction. As described above, the cam 51 (fitting hole 31c) and the connecting shaft 34 (fitting portion 34b) have a fitting clearance in the rotational direction, and the rotary shaft O is interposed between them. There is a play angle centered around. The terminal portion 52c presses the connecting shaft 34 in the clockwise rotation direction shown in the drawing, that is, the rotation direction on the side where the cam 51 allows the upper plate 26 to rotate with respect to the lower plate 21 so as to eliminate the play angle corresponding to the clearance. To do. It goes without saying that the terminal portion 52c presses the connecting shaft 34 at a position adjacent to the axial direction where the cam 51 and the connecting shaft 34 are fitted in the axial direction.

As described above in detail, according to the present embodiment, the following effects can be obtained in addition to the effects (2) to (4) in the first embodiment.
(1) In the present embodiment, the play for the clearance of the fitting between the cam 51 and the connecting shaft 34 is such that the end portion 52c of the spring 52 presses the connecting shaft 34 so that the cam 51 is moved to the upper plate. 26 is eliminated in the rotation direction on the side that allows the rotation of the lower plate 21 with respect to the lower plate 21. Accordingly, when an operating force is input to the connecting shaft 34 in order to allow the upper plate 26 to rotate with respect to the lower plate 21, the play for the clearance is eliminated, so that a suitable operational feeling is achieved. Can be obtained.

  That is, the play of the clearance between the cam 51 and the connecting shaft 34 is eliminated in advance in the rotation direction on the side where the cam 51 allows the upper plate 26 to rotate with respect to the lower plate 21. Thus, as soon as the input of the operating force to the connecting shaft 34 is started, the cam 51 immediately rotates in the rotation direction on the side that allows the upper plate 26 to rotate with respect to the lower plate 21, and Allow (unlock) begins. At this time, since the operating force for rotating the connecting shaft 34 together with the cam 51 gradually increases against the biasing force of the spring 52, a direct operational feeling without an operation dead zone is obtained. The terminal portion 52c is formed by using the spring 52 that urges the cam 51 in the rotation direction on the side that restricts the rotation of the upper plate 26 relative to the lower plate 21. Can be suppressed.

  Furthermore, since the clearance for the clearance is eliminated, for example, when the vehicle is traveling, it is possible to prevent the operation lever 36 from rattling with the connecting shaft 34 and generating abnormal noise. it can.

In addition, you may change the said embodiment as follows.
-In the said 1st Embodiment, arrangement | positioning of the bending part 33c which presses the connection shaft 34 is an example. For example, a bent portion may be formed on the opposite side across the rotation axis O, and the opposite corner of the fitting portion 34b having an oval shape may be pressed by this bent portion. The point is that the connecting shaft 34 may be pressed by the spring 33 in the rotational direction on the side where the cam 31 restricts the rotation of the upper plate 26 relative to the lower plate 21.

  -In the said 2nd Embodiment, arrangement | positioning of the front-end | tip part 42c which presses the connection shaft 34 is an example. For example, a groove portion of the cam 41 is formed on the opposite side across the rotation axis O, and a corner portion on the opposite side of the fitting portion 34b having an oval shape is pressed by the tip portion of the other end 42b introduced from the groove portion. Also good. The point is that the connecting shaft 34 may be pressed by the spring 42 in the rotational direction on the side where the cam 41 restricts the rotation of the upper plate 26 relative to the lower plate 21.

  -In each above-mentioned embodiment, the section of fitting holes 31c and 41b and fitting part 34b is not restricted to an oval shape, and may be D shape or polygonal shape. The flat circular shape includes an elliptical shape and the like.

  In each of the above embodiments, the bent portion 33c or the distal end portion 42c that presses the springs 33 and 42 and the connecting shaft 34 may be displaced from the axial position where the cams 31 and 41 and the connecting shaft 34 are fitted. .

  In each of the above embodiments, the lower plate 21 and the upper plate 26 are held on the seat cushion side and the seat back side, respectively, but these relationships may be reversed.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
In the vehicle seat reclining device according to any one of claims 1 to 8,
The vehicle seat reclining device according to claim 1, wherein a cross-sectional shape of the connecting shaft fitted to the cam is a flat circular shape (an oval shape), a D shape, or a polygonal shape. According to this configuration, the cross-sectional shape of the connecting shaft is a flat circular shape, a D-shape, or a polygonal shape, so that the contact position with the pressing portion can be easily ensured compared to, for example, a serration shape, and the pressing The part can press the connecting shaft in a more stable state.

1 is an exploded perspective view showing a first embodiment of the present invention. The front view which shows the same embodiment. Sectional drawing along the AA line of FIG. The disassembled perspective view which shows the 2nd Embodiment of this invention. The front view which shows the same embodiment. Sectional drawing along the BB line of FIG. The front view which shows the 3rd Embodiment of this invention. The front view which shows the same embodiment.

Explanation of symbols

  O ... Rotating shaft, 11 ... Seat cushion frame, 12 ... Seat back frame, 20, 40 ... Lock mechanism, 21 ... Lower plate, 21b ... Locking hole, 26 ... Upper plate, 31, 41, 51 ... Cam, 31a ... Cam part, 31c, 41b ... fitting hole, 31d ... projecting part, 32 ... pole, 33, 42, 52 ... spring, 33a, 42a, 52a ... one end, 33b, 42b, 52b ... other end, 33c ... pressing part Bending portion as 34, connecting shaft, 34b fitting portion, 36 operation lever, 41a projecting wall portion, 41c groove portion, 42c tip end as pressing portion, 51a, 51b projection, 52c pressing Terminal part as a part.

Claims (8)

A pair of lower plates that are held on either the seat cushion side or the seat back side, and a pair of uppers that are rotatably supported by the lower plates and held on the other side of the seat cushion side or the seat back side A plate, a pair of cams that restrict or allow the rotation of each upper plate with respect to the lower plate as it rotates, and each of the cams is fitted with a clearance, and an operating force is input to the upper plate. A connecting shaft that integrally rotates the pair of cams so as to allow rotation with respect to the lower plate, and a winding shaft that is wound around the rotating shaft of each of the cams, and has one end and the other end that are associated with the lower plate and the cam, respectively. A pair of springs that are stopped and urge the cam in a rotational direction that restricts rotation of the upper plate relative to the lower plate. The seat reclining apparatus for a vehicle having bets,
The seat reclining device for a vehicle, wherein the spring includes a pressing portion that presses the connecting shaft so as to eliminate play of a clearance of fitting between the cam and the connecting shaft in one rotational direction. . The vehicle seat reclining device according to claim 1,
The pressing portion is configured to disengage the connecting shaft so as to eliminate a play corresponding to a clearance of fitting between the cam and the connecting shaft in a rotation direction on a side where the cam restricts rotation of the upper plate with respect to the lower plate. A seat reclining device for a vehicle characterized by pressing. The vehicle seat reclining device according to claim 2,
The cam has a protruding portion that receives the pressing force from the spring with the other end of the spring locked.
The vehicle seat reclining, wherein the pressing portion is a bent portion that applies a pressing force to the connecting shaft at a position different from the position of the protruding portion where the other end of the spring is locked. apparatus. The vehicle seat reclining device according to claim 2,
The cam includes a projecting wall portion that has a fitting hole that fits with the connecting shaft and projects in the axial direction. The projecting wall portion has an opening on the fitting hole side and the spring. A groove is formed to be locked at the other end,
2. The vehicle seat reclining device according to claim 1, wherein the pressing portion is a leading end portion that is introduced into the fitting hole side and presses the connecting shaft at the other end of the spring that is locked to the groove portion. The vehicle seat reclining device according to claim 4,
The vehicle seat reclining device, wherein the pressing portion presses the connecting shaft at an axial position where the cam and the connecting shaft are fitted. The vehicle seat reclining device according to claim 3,
The vehicle seat reclining device, wherein the pressing portion presses the connecting shaft at a position adjacent to the axial position where the cam and the connecting shaft are fitted. The vehicle seat reclining device according to claim 1,
The pressing portion is configured to disengage the connecting shaft so as to eliminate a play corresponding to a clearance of fitting between the cam and the connecting shaft in a rotation direction on the side where the cam allows the upper plate to rotate with respect to the lower plate. A seat reclining device for a vehicle characterized by pressing. The vehicle seat reclining device according to claim 7,
The cam has a protrusion to which the other end of the spring is locked,
The vehicle seat reclining device, wherein the pressing portion is a terminal portion that extends from a position of the projection to which the other end of the spring is locked and applies a pressing force to the connecting shaft.

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