JP2007029618A - Seat reclining apparatus for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a surface having a shear-drooped part from becoming a press-fitting surface side when press-fitting an external tooth gear manufactured by press molding in an internal tooth for a press-fitting a base plate. <P>SOLUTION: A press-fitting internal tooth 38 formed on the base plate 30 is provided with wide-width recessed portions 38a and 38b formed by providing no tooth, while the press-fitting surface side of the external tooth gear 10 is formed with a wide-width projecting portion 10b by filling the interval between the teeth to be fitted in the wide-width recessed portions 38a and 38b. When press-fitting the surface where the wide-width projecting portion 10b is formed to an engagement face side, the part of the wide-width projecting portion 10b of the external gear 10 is not engaged with the internal tooth gear 20 so as to detect the erroneous assembling. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle seat reclining device, which has a gear reduction mechanism with a small number of teeth difference method, and prevents erroneous assembly of gears.

  A differential transmission mechanism is adopted as an angle adjustment mechanism of the back seat in the vehicle seat reclining device, and the back seat is rotated at a high reduction ratio by electric drive.

As a conventional vehicle seat reclining device employing the differential transmission mechanism as described above, there are those described in Patent Documents 1 and 2. A base plate having a plurality of circular protrusions for fixing to the seat cushion side mounting arm, an external gear fixed to the base plate, and a circular protrusion for fixing to the seat back side mounting arm and the external teeth An internal gear that has one or two more teeth meshed with the external teeth of the gear than the external teeth, an eccentric drive means for moving the meshing portion of the internal gear with respect to the external gear in the circumferential direction, a base plate, A tooth ring and an inner tooth gear are overlapped in the axial direction and are configured by a holder ring that holds the outer peripheral portion thereof.
JP 2000-166679 A French additional patent FR-A-2759333

  However, in the vehicle seat reclining devices described in Patent Documents 1 and 2, the external gear is enlarged because the external gear is provided in two stages, one is press-fitted into the base plate, and the other is engaged with the internal gear. .

  On the other hand, it is conceivable that the external gear is in one stage and one side is press-fitted into the base plate, and the other side is meshed with the internal gear. However, as shown in FIG. In the case of manufacturing, a chamfered extracted portion 10a is generated on the outer peripheral surface of the end portion on one side (press-out side) of the external gear 10. When the surface where the extracted portion 10a exists is press-fitted into the base plate, the length in the axial direction of the portion that is press-fitted and coupled is shortened, so that there is a problem that the press-fitting strength is weakened. Therefore, even if it is misassembled, it cannot be found.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle seat reclining device that solves the above-described problems and can detect the occurrence of erroneous assembly.

  According to the first aspect of the present invention, there is provided a first member having an external gear coupled to one of a seat cushion and a seat back having a lower end pivotably provided with respect to the seat cushion, and the other. A second member having an internal gear having a larger number of teeth than the external gear, and a meshing portion in which the internal gear meshes with the external gear is moved along a circumference, and the first member The first member is press-fitted into a base plate coupled to the seat cushion or the seat back, and an eccentric drive mechanism that rotates the second member relative to the drive mechanism and a drive unit that drives the eccentric drive mechanism. In the vehicle seat reclining device, the internal teeth are formed, the press-fitting surface side of the external gear is press-fitted into the press-fitting internal teeth, and the meshing surface side of the external gear meshes with the internal gear. The internal teeth are formed with wide concave portions that are portions without teeth, and on the press-fitting surface side of the external gear, wide convex portions that are portions between the teeth and that enter the wide concave portions are formed. Features.

  According to this invention, the wide convex portion formed on the press-fitting surface side of the external gear is fitted and press-fitted into the wide concave portion formed in the press-fitting inner teeth. If the external gear is fitted with the press-fitting surface side and the meshing surface side upside down, when the rotational inspection is performed by moving the meshing portion where the external gear meshes with the internal gear in the circumferential direction, Since the portion does not mesh with each other, the meshing portion does not move, thereby detecting erroneous assembly. Therefore, if one side surface where the extracted portion generated when manufacturing the external gear by press molding is erroneously press-fitted, this is detected as an erroneous assembly.

  The invention according to claim 2 is the vehicle seat reclining device according to claim 1, wherein a plurality of combinations of the wide concave portion and the wide convex portion are provided.

  According to this invention, since a plurality of combinations of the wide concave portion and the wide convex portion are arranged in the circumferential direction, when the wide convex portion is located at the meshing portion during assembly, it is difficult to assemble it. Incorrect assembly itself can be prevented.

  According to the vehicle seat reclining device of the present invention, the inner portion for press-fitting is provided with a toothless portion to form a wide concave portion, while the outer gear is formed with a wide convex portion in which a space between teeth is buried. Therefore, if the wide convex part is fitted into the wide concave part and assembled, and the press-fitting surface side and the meshing surface side of the external gear are mistakenly installed upside down, the external gear meshes with the internal gear. When the rotation inspection is performed by moving the portion in the circumferential direction, the engagement portion is not moved because the engagement portion is not engaged in the portion provided with the wide convex portion, and erroneous assembly is detected. Therefore, if one side where the extracted part that occurs when manufacturing an external gear by press molding is accidentally press-fitted, this is detected, and the depth of the press-fitted joint is insufficient. The problem that the press-fit strength is reduced is prevented in advance.

  Hereinafter, embodiments of a vehicle seat reclining device according to the present invention will be described. The seat reclining device is provided between an attachment arm provided on the seat cushion and an attachment arm provided on the seat back, and adjusts an inclination angle of the seat back with respect to the seat cushion.

  An exploded perspective view and a sectional view of the seat reclining device are shown in FIGS. The seat reclining device includes a base unit (first member) 1 coupled to a seat cushion mounting arm 70, an internal gear (second member) 20 coupled to a seat back mounting arm 60, and a motor (not shown) And a center shaft 41 that is rotationally driven by a driving means).

  The configuration of the base unit 1 will be described. As shown in FIGS. 1 to 3, a circular recess 33 is formed on the surface of the base plate 30 facing the internal gear 20, and press-fitting internal teeth 38 are formed on the inner peripheral surface of the recess 33. ing. The base unit 30 is configured by integrating the base plate 30 and the external gear 10 by press-fitting the external gear 10 into the press-fitting internal teeth 38. As shown in FIG. 4, the right side in the axial direction of the external gear 10 is a press-fitting surface side that is press-fitted into the press-fitting inner teeth 38, and the left side is a meshing surface side that meshes with the internal gear 20.

  As shown in FIG. 2, each of the press-fitting inner teeth 38 has a wide concave portion 38a in which one internal tooth is omitted and a wide concave portion 38b in which two internal teeth are omitted alternately in three locations along the circumferential direction. Is formed.

  On the other hand, as shown in FIG. 1, a wide convex portion 10b is formed on the press-fitting surface side of the external gear 10 so as to fill one gap between the teeth and enter the wide concave portion 38a. The wide convex portion 10b may be fitted into either the wide concave portion 38a or the wide concave portion 38b. Further, as the external gear 10, one that is formed by press molding and has an extraction portion 10 a on one side surface (press release side) is used. As shown in FIG. 4, the meshing surface side of the external gear 10 is used. A dripping portion 10a is formed.

  As shown in FIG. 3, the internal gear 20 has a circular concave portion on the right side surface by forming a circular convex portion on the left side surface. And the internal tooth which is not illustrated is formed in the internal peripheral surface of this recessed part. As shown in FIG. 5, the number of teeth in the external gear 10 is, for example, 33, whereas the number of teeth in the internal gear 20 is 34, and the number of internal teeth is one more than the number of external teeth. Only has increased. Since the number of internal teeth is large, the center B of the internal gear 20 is eccentric downward and meshes with the center A of the external gear 10 at the moment.

  As shown in FIG. 5, an eccentric drive mechanism 3 is provided for moving a meshing portion H with which the internal gear 20 meshes with the external gear 10 along the circumference. The configuration of the eccentric drive mechanism 3 will be described below. A bearing cylinder 25 concentric with the internal gear 20 is formed inside the internal gear 20, while an internal peripheral surface 15 concentric with the external gear 10 is formed on the external gear 10. A circular eccentric space 4 is formed between the outer peripheral surface 25 a of the bearing cylinder 25 and the inner peripheral surface 15 of the external gear 10. A pair of lock plates 46 are disposed in the eccentric space 4, and the pair of lock plates 46 move in the eccentric space 4 along the circumferential direction, whereby the center B of the internal gear 20 becomes the external gear. Since the portion corresponding to the pair of lock plates 46 in the circumferential direction is pressed against the external gear 10 to cause meshing, the meshing is adjacent. The teeth will move on. That is, the meshing portion H is formed on the side where the pair of lock plates 46 are located, and the meshing portion H moves along the circumferential direction.

  If the lock plate 46 is configured as a single unit, the backlash at the meshing portion H increases or decreases when there is a variation in dimensions. Therefore, in order to always maintain a state without backlash, a pair of lock plates 46, and a spring 47 for urging the pair of lock plates 46 in the circumferential direction away from each other. The lock plate 46 is formed with a notch 46b for engaging the engaging portion 47a of the end of the spring 47 at the end of the larger width dimension.

  As shown in FIG. 5, the pair of lock plates 46 are fitted into the eccentric space 4 in a state where the ends having the larger width dimension are in contact with each other. The pair of lock plates 46 are urged in opposite directions in the circumferential direction by the urging force of the spring 47, and the center A of the external gear 10 and the center B of the internal gear 20 are caused by the wedge effect. The distance between them increases, and the pair of lock plates 46 maintains a state in which there is no gap between the bearing cylinder 25 and the external gear 10 without play. That is, the internal gear 20 is pushed downward in FIG. 5 with respect to the external gear 10, and the meshing with the external gear 10 is deepened, so that there is no backlash.

  The center shaft 41 is provided to press and move the pair of lock plates 46 arranged as described above along the circumferential direction inside the eccentric space 4. The center shaft 41 presses one end of the one lock plate 46 whose width is narrow along the circumferential direction, and turns the one lock plate 46. Here, when the pair of lock plates 46 are rotated once in the circumferential direction by the center shaft 41, the meshing position of the internal gear 20 with respect to the external gear 10 is one center tooth 41 corresponding to the difference in the number of teeth. Accordingly, the internal gear 20 is decelerated relative to the base unit 1 in the same direction as the rotation direction of the center shaft 41 with a high reduction ratio and is rotated relatively.

  The shape of the center shaft 41 will be described with reference to FIG. The center shaft 41 is formed integrally with the cylinder portion 42 inserted into the bearing cylinder 25 formed inside the internal gear 20, and the pair of lock plates 46 move in the axial direction. Thus, the flange portion 43 that restricts the eccentric space 4 from falling off and a pair of pressing portions 45 that protrude from the flange portion 43 along the axial direction are configured. An input shaft (not shown) connected to a motor (driving means) (not shown) is inserted inside the cylinder portion 42, and a rotational force can be transmitted from the input shaft to the cylinder portion 42. A plurality of axial grooves 41a are formed along the circumferential direction. A pair of pressing portions 45 is inserted into the eccentric space 4 from the axial direction by inserting the cylindrical portion 42 into the bearing cylinder 25, and each pressing portion 45 has a pair of pairs as shown by hatching in FIG. The lock plate 46 is located near the lower surface of the narrower width.

  As shown in FIGS. 3 and 4, the respective members are assembled in the axial direction, and a holder ring 50 is provided for restricting in the axial direction so that the base unit 1 and the internal gear 20 can rotate relatively. Yes. The side surface 51 of the holder ring 50 in FIG. 4 has a cylindrical shape before assembly, and is bent at a substantially right angle by narrowing down after the base unit 1 and the internal gear 20 are assembled.

  In order to prevent relative rotation between the base plate 30 and the mounting arm 70, the base plate 30 is formed with six circular protrusions 34 in the circumferential direction by embossing, while the mounting arm 70 has six fitting holes 71. The circular protrusions 34 are fitted into the fitting holes 71 and welded to each other. The internal gear 20 and the mounting arm 60 are also provided with six circular protrusions 24 and six fitting holes 61 for the same purpose. In addition, center holes 72, 35, and 62 are provided in the mounting arm 70, the base plate 30, and the mounting arm 60, respectively.

  Next, the operation of the vehicle seat reclining device will be described.

  First, assembly of the vehicle seat reclining device will be described. As shown in FIG. 5, the external gear 10 is meshed with the internal gear 20, and the pair of lock plates 46 are arranged in the eccentric space 4. As shown in FIGS. 3 and 4, after incorporating the spring 47 and the center shaft 41, the external gear 10 is press-fitted into the press-fitting inner teeth 38 of the base plate 30. At this time, as shown in FIG. 1, the wide convex portion 10b formed on the press-fitting side surface of the external gear 10 is press-fitted in a state of being fitted into the wide concave portion 38a or the wide concave portion 38b formed in the press-fitting inner teeth 38. become. Thereafter, the outer peripheral portions of the internal gear 20 and the base plate 30 are covered with a holder ring 50 to narrow down, thereby forming a side portion 51 and integrating them.

  If the press-fitting surface side and the meshing surface side of the external gear 10 are assembled upside down at the time of this assembly, the wide convex portion 10b is positioned on the meshing surface side. Therefore, when the meshing portion H in which the external gear 10 meshes with the internal gear 20 is moved in the circumferential direction and rotationally inspected, meshing is not performed at the position where the wide convex portion 10b exists. Therefore, it is detected that the meshing part H does not move and is misassembled. For this reason, when the external gear 10 having the extracted portion 10a generated when the external gear 10 is manufactured by press molding is used, one side surface where the extracted portion 10a exists is mistakenly used as the press-fitting internal tooth. In the case of press-fitting, this is detected as an erroneous assembly.

  Next, when the center shaft 41 rotates in any direction by rotating a motor (not shown), one of the pair of pressing portions 45 has one of the pair of lock plates 46 wider from the narrower side depending on the rotation direction. Press to the side. At this time, while the spring 47 is slightly compressed and the other lock plate 46 is rotated slightly in the same direction by the amount of compression, the pair of lock plates 46 are formed in the eccentric space without causing a gap between the members. It turns along the circumference inside 4. Thereby, the internal gear 20 and the external gear 10 mesh with each other at a portion corresponding to the pair of lock plates 46 in the circumferential direction, and the meshing portion H that is the meshing portion moves along the circumferential direction. When the meshing portion H makes one turn, the number of teeth of the internal gear 20 is one more than that of the external gear 10, so that the internal gear 20 itself turns the pair of lock plates 46 and the rotational direction of the meshing portion H. Rotate one tooth in the same direction as. That is, when the center shaft 41 is rotated, the internal gear 20 is decelerated with a large reduction ratio together with the seat back with respect to the base unit 1 fixed to the seat cushion, and is rotated in the same direction as the center shaft 41 rotates. Will do.

  In the present embodiment, the case where there is one wide convex portion 10b that fits into either of the wide concave portions 38a, 38b is shown, but a plurality of combinations are provided by increasing the number of wide convex portions 10b. May be. In this case, the wide protrusion 10b is positioned at the meshing portion H at the time of assembly without performing a rotation inspection, so that the assembly itself becomes difficult, so that erroneous assembly itself is prevented, and the inspection process is abolished and the number of discarded parts is reduced. Can be made. Moreover, although the case where the base plate is attached to the seat cushion has been described in the present embodiment, the base plate may be attached to the seat back.

A perspective view of an internal gear and an external gear in a vehicle seat reclining device (embodiment). The front view which looked at the base plate from the inner side (embodiment). 1 is an exploded perspective view of a vehicle seat reclining device (embodiment). Sectional drawing of vehicle seat reclining apparatus (embodiment). Explanatory drawing for demonstrating the effect | action of the vehicle seat reclining apparatus (embodiment). It is related with an external gear, (a) is a front view, (b) is a side view (conventional).

Explanation of symbols

1 ... Base unit (first member)
DESCRIPTION OF SYMBOLS 3 ... Eccentric drive mechanism 10 ... External gear 10a ... Extraction part 10b ... Wide convex part 20 ... Internal gear (2nd member)
DESCRIPTION OF SYMBOLS 30 ... Base plate 38 ... Press-fit inner teeth 38a, 38b ... Wide recessed part 41 ... Center shaft H ... Meshing part 60 ... Seat back side mounting arm 70 ... Seat cushion side mounting arm

Claims (2)

A first member having an external gear coupled to one of a seat cushion and a seat back having a lower end pivotably provided with respect to the seat cushion, and coupled to the other than the external gear. A second member having an internal gear with a large number of teeth, and a meshing portion where the internal gear meshes with the external gear are moved along a circumference, and the second member is moved with respect to the first member. An eccentric drive mechanism for relatively rotating; and a drive means for driving the eccentric drive mechanism;
In the first member, a press-fitting inner tooth is formed on a base plate coupled to the seat cushion or the seat back, and the press-fitting surface side of the external gear is press-fitted to the press-fitting inner tooth, and the meshing surface side of the outer gear is In the vehicle seat reclining device engaged with the internal gear,
The press-fitting inner teeth are formed with wide concave portions that are portions without teeth, while the external gears are formed with wide convex portions that are between the teeth and are inserted into the wide concave portions on the press-fitting surface side. A vehicle seat reclining device. 2. The vehicle seat reclining device according to claim 1, wherein a plurality of combinations of the wide concave portion and the wide convex portion are provided.

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