Retracting mechanism of vehicular outer mirror device

[0001] This application claims priority under 35 USC 119 from Japanese Patent Application No. 2004-261622, the disclosure of which is incorporated by reference herein.

[0002] 1. Field of the Invention

[0003] The present invention relates to a retracting mechanism of a vehicular outer mirror device disposed in a vehicle.

[0004] 2. Description of the Related Art

[0005] There is a vehicular door mirror device disposed with a retracting mechanism (e.g., see Japanese Patent Application Publication (JP-A) No. 2002-67805).

[0006] This type of retracting mechanism includes a support shaft fixed to a vehicle body, and a case member is pivotably supported on the support shaft. A rearview mirror is coupled to the case member, and the case member is always pivoted integrally with the mirror.

[0007] A gear plate formed as a helical gear is disposed on the support shaft inside the case member in a state where the rotation of the gear plate is prevented (deterred). A motor is fixed inside the case member, and a motor gear such as a worm gear is coupled to the output shaft of the motor. Intermediate gears such as twin gear comprising a worm gear and a helical gear are disposed inside the case member. The gears mesh with the motor gear of the motor output shaft and the gear plate, so that the motor gear and the gear plate are coupled together. Thus, when the motor is driven, the intermediate gears rotate while meshing the periphery of the gear plate. Thus, the case member is pivoted around the support shaft, and the mirror is stored or erected.

[0008] At the coupled portion of the output shaft of the motor and the motor gear, the end portion of the motor output shaft is formed in a double D-cut, where two sites opposing each other in the circumferential direction are chamfered in planar shapes, in order to transmit the rotational force of the motor to the motor gear. Thus, the output shaft of the motor and the motor gear are coupled together, and the rotational force of the motor is transmitted to the motor gear (e.g., see Japanese Utility Model Application Publication No. 5-58484).

[0009] However, when the motor is driven, a reaction force from the gear plate and the intermediate gears acts on the motor gear, and the motor gear tries to slant. Namely, at the coupled portion of the output shaft of the motor and the motor gear, a reaction force alternately acts on the D-cut surface and the circumferential surface other than the D-cut portion, and the motor gear repeatedly slants (wobbles) and does not slant (does not wobble) at a 90° pitch in accompaniment with the rotation of the output shaft of the motor. As a result, abnormal noises occur.

[0010] In consideration of these circumstances, the present invention provides a retracting mechanism of a vehicular outer mirror device that can stably couple the output shaft of the motor and the motor gear together and prevent the occurrence of abnormal noises.

[0011] A retracting mechanism of a vehicular outer mirror device of a first aspect of the invention comprises: a case member that is pivotably supported on a support shaft of a vehicle body and to which a vehicular outer mirror is coupled; a motor disposed in the case member; a motor gear that is disposed in the case member, is coupled to an output shaft of the motor, and is rotated by the driving of the motor; a gear plate attached to the support shaft such that its rotation with respect to the support shaft can be prevented; and intermediate gears that are disposed in the case member and mesh with the motor gear and the gear plate to couple the motor gear and the gear plate together, with the intermediate gears rotating while meshing the periphery of the gear plate in a state where the rotation of the gear plate with respect to the support shaft is prevented (deterred), whereby the outer mirror is pivoted together with the case member around the support shaft, wherein the coupled portion of the output shaft of the motor and the motor gear includes coupling retaining portions that are fitted together in a press-fitted state, retain the coupled state of the output shaft of the motor and the motor gear on the same axial line, and deter the slanting of the motor gear, and rotational force transmitting portions that oppose each other in a state where a predetermined gap is present between them and transmit only the rotational force of the motor to the motor gear.

[0012] It is preferable for the coupling retaining portions to be configured by a circular shaft portion that is disposed on the output shaft of the motor and is formed in a cross-sectionally circular shape and by a circular fitting hole that is formed in the motor gear so as to fit together with the circular shaft portion. Also, it is preferable for the rotational force transmitting portions to be configured by a double D-cut portion that is disposed on the output shaft of the motor and formed as the result of two sites that oppose each other in the circumferential direction being chamfered in planar shapes and by double D-protruding portions that are formed in the motor gear in correspondence to the double D-cut portion.

[0013] In the retracting mechanism of a vehicular outer mirror device of the first aspect of the invention, when the motor is driven in a state where the rotation of the gear plate with respect to the support shaft is prevented, the intermediate gears rotate while meshing the periphery of the gear plate. Thus, the case member is pivoted around the support shaft, and the outer mirror is stored or erected.

[0014] Here, the coupling retaining portions mutually fitted together in a press-fitted state and the rotational force transmitting portions opposing each other in a state where a predetermined gap is present between them are disposed at the coupled portion of the output shaft of the motor and the motor gear. The rotational force of the motor output shaft is transmitted by the rotational force transmitting portions, and the coupled state of the output shaft and the motor gear is retained on the same axial line and the slanting of the motor gear is prevented by the coupling retaining portions.

[0015] Namely, the coupled portion of the output shaft of the motor and the motor gear is configured to not just simply transmit the rotational force but also retain the coupled state of the output shaft and the motor gear. Moreover, the rotational force transmitting portions function to transmit the rotational force, and the coupling retaining portions function to retain the coupled state of the output shaft and the motor gear. In this manner, the respective functions are divided between independent separate sites.

[0016] For this reason, the output shaft of the motor and the motor gear can be stably coupled together, and even if the reaction force from the gear plate and the intermediate gears acts on the motor gear and the motor gear tries to slant—i.e., even if the reaction force alternately acts on the D-cut surface and the circumferential surface other than at the D-cut portion as has conventionally been the case—the motor gear does not repeatedly slant (wobble) and not slant (not wobble) at a 90° pitch in accompaniment with the rotation of the output shaft of the motor. As a result, the occurrence of abnormal noises can be prevented.

[0017] A retracting mechanism of a vehicular outer mirror device of a second aspect of the invention comprises: a support shaft fixed to a vehicle body; a case member that is pivotably supported on the support shaft and retains a vehicular outer mirror; a motor disposed in the case member; a motor gear that is disposed in the case member, is coupled to an output shaft of the motor, and is rotated by the driving of the motor; and a rotation transmitting mechanism that transmits the rotation of the motor gear to the support shaft to thereby cause the case member to rotate around the support shaft, wherein in the portion where the output shaft of the motor and the motor gear are coupled together, there are formed coupling retaining portions where the output shaft and the motor gear are fitted together and which retain their axial centers on the same axial line, and rotational force transmitting portions where the output shaft and the motor gear include mutually opposing planar surfaces and where the rotational force is transmitted between the output shaft and the motor gear via the planar surfaces.

[0018] A retracting mechanism of a vehicular outer mirror device of a third aspect of the invention comprises: a support shaft fixed to a vehicle body; a case member that is pivotably supported on the support shaft and retains a vehicular outer mirror; a motor disposed in the case member; a motor gear that is disposed in the case member, is coupled to an output shaft of the motor, and is rotated by the driving of the motor; and a rotation transmitting mechanism that transmits the rotation of the motor gear to the support shaft to thereby cause the case member to rotate around the support shaft, wherein in the portion where the output shaft of the motor and the motor gear are coupled together, there are formed coupling retaining portions where the output shaft and the motor gear are fitted together and which retain their axial centers on the same axial line, and rotational force transmitting portions where the output shaft and the motor gear include surfaces that oppose each other in a state where they include a predetermined gap and where the rotational force is transmitted between the output shaft and the motor gear via the surfaces.

[0019] As described above, the retracting mechanism of a vehicular outer mirror device of the present invention has excellent effects in that it can stably couple the output shaft of the motor and the motor gear together and prevent the occurrence of abnormal noises.

[0026] The overall configuration of a vehicular outer mirror device 10 to which a retracting mechanism 18 pertaining to an embodiment of the invention has been applied is shown in exploded perspective view in FIG. 6.

[0027] The vehicular outer mirror device 10 is formed as a door mirror device and includes a frame 12. A retaining member 14 is fixed to the frame 12, and a rearview mirror 16 is retained on the retaining member 14. The frame 12 is fixed to the retracting mechanism 18, which will be described in detail later. The retracting mechanism 18 is attached to a door mirror stay 20 that is fixed to a door (not shown) of a vehicle. Thus, the retracting mechanism 18 supports the mirror 16 via the frame 12 and the retaining member 14. The retracting mechanism 18 is a mechanism positioned in a deployed position, where it pivots the mirror 16 and is erect with respect to the door of the vehicle, and a stored position, where it is folded substantially along the door.

[0028] The frame 12, the retaining member 14 and the retracting mechanism 18 are housed in a door mirror visor 22. The door mirror visor 22 is configured by a vehicle front-side visor cover 24 and a vehicle rear-side visor rim 26 that are joined together. The visor cover 24 and the visor rim 26 are both fixed to the frame 12.

[0029] Here, the overall configuration of the retracting mechanism 18 is shown in cross-sectional view in FIG. 1.

[0030] The retracting mechanism 18 includes a stand 28 fixed to the door mirror stay 20. A support shaft 30 formed in a substantially circular cylindrical shape is disposed integrally with the stand 28 such that it rises vertically from the stand 28.

[0031] The retracting mechanism 18 also includes a case member 36. The case member 36 is formed in a substantially box-like shape. The support shaft 30 penetrates the case member 36 from below, whereby the case member 36 is axially supported on the support shaft 30 and is rotatable with respect to the support shaft 36. The case member 36 is fixed to the frame 12 and is always rotatable around the support shaft 30 integrally with the mirror 16 coupled via the frame 12 and the retaining member 14.

[0032] A drive motor 42 is fixedly housed inside the case member 36. A worm gear 46 serving as a motor gear is attached to an output shaft 44 of the motor 42. The upper end portion of the worm gear 46 is coupled to the output shaft 44, and the lower end portion of the worm gear 46 is supported on a support shaft 47. A helical gear 48 serving as an intermediate gear meshes with the worm gear 46. A shaft worm 50 serving as an intermediate gear is disposed integrally with the helical gear 48. The helical gear 48 and the shaft worm 50 always rotate integrally.

[0033] A gear plate 52 that configures the retracting mechanism 18 and has a substantially circular cylindrical shape is disposed inside the case member 36. The inner peripheral surface of the gear plate 52 corresponds to the outer peripheral surface of the support shaft 30. The support shaft 30 penetrates the gear plate 52, whereby the gear plate 52 is rotatably axially supported. A peripheral tooth 52A is formed on the outer peripheral surface of the gear plate 52. The gear plate 52 meshes with the shaft worm 50 at the peripheral tooth 52A. Thus, the rotational force of the drive motor 42 is transmitted to the gear plate 52 via the worm gear 46, the helical gear 48 and the shaft worm 50.

[0034] A clutch mechanism portion 54 is disposed at the periphery of the support shaft 30 above the gear plate 52. The clutch mechanism portion 54 ordinarily deters the rotation of the gear plate 52 with respect to the support shaft 30. Consequently, when the drive motor 42 is activated and the rotational force of the drive motor 42 is transmitted to the gear plate 52, the shaft worm 50 rotates while meshing the periphery of the gear plate 52 as a result of the reaction force of the rotational force. Thus, the case member 36 is pivoted around the support shaft 30 and the mirror 16 pivots in the retracting direction or the erect direction.

[0035] The coupled portion of the output shaft 44 of the drive motor 42 and the worm gear 46 is shown in cross-sectional view in FIG. 2, and a state where the output shaft 44 and the worm gear 46 shown in FIG. 2 have rotated 90 degrees is shown in FIG. 3.

[0036] The coupled portion is configured by coupling retaining portions 60 and rotational force transmitting portions 62.

[0037] As shown in FIG. 4, the coupling retaining portions 60 are configured by a circular shaft portion 64 and a circular fitting hole 66. The circular shaft portion 64 is disposed on the output shaft 44 of the drive motor 42 and is formed in a cross-sectionally circular shape. The circular fitting hole 66 is formed in the worm gear 46 in correspondence to the circular shaft portion 64. The coupling retaining portions 60 are fitted together in a press-fitted state and configured to retain the coupled state of the output shaft 44 and the worm gear 46 on the same axial line and to deter the slanting of the worm gear 46.

[0038] As shown in FIG. 5, the rotational force transmitting portions 62 are configured by a double D-cut portion 68 and double D-protruding portions 70. The double D-cut portion 68 is formed further towards the end of the output shaft 44 than the circular shaft portion 64. The double D-protruding portions 70 are formed in the worm gear 46 in correspondence to the double D)-cut portion 68. The double D-cut portion 68 is formed as the result of two sites that oppose each other in the circumferential direction being chamfered in planar shapes. The double D-cut portion 68 and the double D-protruding portions 70 oppose each other in a state where a predetermined slight gap is present between them. Namely, the double D-cut portion 68 and the double D-protruding portions 70 transmit only the rotational force of the drive motor 42 (the output shaft 44) to the worm gear 46.

[0039] Next, the action of the present embodiment will be described.

[0040] In the vehicular outer mirror device 10 to which the retracting mechanism 18 with the above configuration has been applied, ordinarily (in a state where the rotation of the gear plate 52 with respect to the support shaft 30 is prevented by the clutch mechanism portion 54), when the drive motor 42 is driven and the worm gear 46 is rotated, the rotational force is transmitted to the gear plate 52 via the worm gear 46, the helical gear 48 and the shaft worm 50, and the shaft worm 50 rotates (revolves) while meshing with the periphery of the gear plate 52 as a result of the reaction force of the rotational force. Thus, the case member 36 is pivoted around the support shaft 30, and the mirror 16 is pivoted in the retracting direction or the erect direction.

[0041] Here, in the retracting mechanism 18 pertaining to the present embodiment, the coupling retaining portions 60 (the circular shaft portion 64 and the circular fitting hole 66) mutually fitted together in a press-fitted state and the rotational force transmitting portions 62 (the double D-cut portion 68 and the double D-protruding portions 70) opposing each other in a state where a predetermined gap is present between them are disposed at the coupled portion of the output shaft 44 of the drive motor 42 and the worm gear 46. The rotational force of the drive motor 42 (the output shaft 44) is transmitted by the rotational force transmitting portions 62, and the coupled state of the output shaft 44 and the worm gear 46 is retained on the same axial line and the slanting of the worm gear 46 is prevented by the coupling retaining portions 60.

[0042] Namely, the coupled portion of the output shaft 44 of the drive motor 42 and the worm gear 46 is configured to not just simply transmit the rotational force but also retain the coupled state of the output shaft 44 and the worm gear 46. Moreover, the rotational force transmitting portions 62 function to transmit the rotational force, and the coupling retaining portions 60 function to retain the coupled state of the output shaft 44 and the worm gear 46. In this manner, the respective functions are divided between independent separate sites.

[0043] For this reason, the output shaft 44 of the drive motor 42 and the worm gear 46 can be stably coupled together, and even if the reaction force from the gear plate 52, the helical gear 48 and the shaft worm 50 acts on the worm gear 46 and the worm gear 46 tries to slant—i.e., even if the reaction force alternately acts on the D-cut surface and the circumferential surface other than at the D-cut portion as has conventionally been the case—the worm gear 46 does not repeatedly slant (wobble) and not slant (not wobble) at a 90° pitch in accompaniment with the rotation of the output shaft 44 of the drive motor 42. As a result, the occurrence of abnormal noises can be prevented.

[0044] In this manner, in the retracting mechanism 18 applied to the vehicular outer mirror device 10 pertaining to the present embodiment, the output shaft 44 of the drive motor 42 and the worm gear 46 can be stably coupled together and the occurrence of abnormal noises can be prevented.

[0045] In the present embodiment, a configuration was described where the retracting mechanism 18 was applied to the vehicular outer mirror device 10 formed as a door mirror device, but the retracting mechanism pertaining to the invention may also be applied to a vehicular fender mirror device or the like.