JP2000085470A - Outside mirror device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outside mirror device for an automobile reducing load applied to a gear train for transmitting the driving force of a motor. SOLUTION: A worm gear 21 impeding the transmission of rotational force applied from a main gear 12 is used as a gear to be meshed with the main gear 12, gears rotated by rotational force applied from lower stage gears are used as a gear train between the worm gear 21 and the motor 22. An outside mirror is stopped in a service position and a storage position by the worm gear 21, and since rotational force is not applied to the gear train between the worm gear 21 and the motor 22 other than the driving time of the motor, deformation, distortion and damage caused by stress application of the gear train are suppressed to a minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a door mirror device mounted on a front door of an automobile.

[0002]

2. Description of the Related Art Conventionally, an electrically retractable door mirror is rotated from a storage position (rearward tilting position) to a use position (side upright position) or from a use position to a storage position by driving a motor. Alternatively, as a position control method for stopping at the storage position, there is known a method of physically forcibly stopping the door mirror by a position restricting means such as a stopper when the door mirror reaches the use or storage position. According to this method, when a door mirror is stopped by a stopper, an excessive current flowing through a motor is detected and stopped (for example, Japanese Patent Laid-Open No. 7-29033). In this publication, a spring stopper and a projection are formed on a base plate fixed to the vehicle body, and a groove for accommodating the spring stopper and the projection is formed on the other side of the rotating mirror holder. A structure is disclosed in which a position where the mirror holder stops at a part is used as a mirror holder and a storage position.

[0003] In the above structure, when the motor is turned off after the spring stopper or the projection comes into contact with the end of the groove and stops at the use position or the storage position, the force for pressing the spring stopper or the projection against the end of the groove is reduced. Disappearing and the mirror holder may rotate in the direction in which the spring stopper or protrusion tends to move away from the end of the groove. To cope with this, a function to prevent this is provided to the gear group. For example, in the above structure, the main gear (referred to as a center gear in the specification)
A worm gear meshing with the worm gear is provided so that the worm gear cannot be rotated against the rotational power from the main gear. The reverse rotation of the main gear is prevented, and the mirror holder is fixed at a predetermined position.

[0004]

However, in the above structure, a worm gear is also attached to the drive shaft of the motor, which also prevents the transmission of rotational power from the lower stage. To the gear group between the worm gears that mesh with each other, a turning power is always applied in a specific direction even when the door mirror is not rotated. Therefore, it is necessary to design in consideration of the stress constantly applied to the gear group, and conventionally, a sintered metal having high strength has been used. If such a gear group is made of metal, an increase in weight is inevitable, which has been a factor that hinders downsizing and weight reduction of the door mirror mechanism.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an automobile door mirror device in which most of the gears can be formed of resin, and thus can be reduced in size and weight. .

[0006]

According to a first aspect of the present invention, there is provided a door mirror device comprising: a base plate formed so as to protrude substantially horizontally outside a vehicle body of a front door; and a main shaft supported substantially vertically by the base plate. A mirror holder rotatably supported by the main shaft; a main gear fitted to the main shaft for rotating the mirror holder; a motor for rotating the main gear; A group of gears interposed between gears for transmitting a driving force and having a deceleration function, and a group of gears interposed in a driving force transmission path by the motor and when a large force is suddenly applied to the mirror holder side, the vehicle body side And a clutch for releasing the coupling on the mirror holder side, and an automobile door mirror device comprising:
Of the gear group, only the gear that meshes with the main gear is constituted by a worm gear that prevents transmission of the rotational force applied from the lower gear, and the gear between the worm gear and the motor is a rotational force applied from the lower gear. Is transmitted.

In this configuration, when the door mirror arrives at the use position or the storage position by driving the motor and stops by the action of the position restricting means, and the motor is turned off, the reverse rotation force of the main gear is prevented by the worm gear meshing therewith. Then, the door mirror is surely stopped.
At the same time, the rotational force applied to the gear positioned higher than the worm gear is released.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 3, reference numeral 1 denotes a plastic or metal base plate formed so as to protrude substantially horizontally to the outside of a vehicle front door.
A hollow plastic or metal main shaft which is supported almost vertically in the center of the base plate 1,
It is fixed to the base plate 1 integrally with the base plate 1 or by screws or the like. The main shaft 2 is provided with a large-diameter portion 3 below and a small-diameter portion 4 above, and in the intermediate region 5, four elongated ridges 6 extending along the axial direction continuous with the large-diameter portion 3 are formed at equal intervals. Have been. Reference numeral 7 denotes an upper surface of the base plate 1, which is a pair of arc-shaped convex portions formed on the circumference around the main shaft 2 so as to face each other. Have been.

Reference numeral 8 denotes a mirror holder having a circular opening 9 formed thereon. The large diameter portion 3 of the main shaft 2 is rotatably supported on the base plate 1 through the opening 9. Reference numeral 10 denotes an arc-shaped groove formed on the back surface of the mirror holder 8 and around the opening 9 and accommodates the convex portion 7. The convex portion 7 moves in the groove 10. Both ends of the groove 10 are formed on inclined surfaces corresponding to both end shapes of the convex portion 7.
The use position is set when the protrusion 7 contacts one end of the groove 10, and the storage position is set when the protrusion 7 contacts the other end of the groove 10. The convex portion 7 and the groove 10 constitute a position restricting means for determining a use position and a storage position of the mirror holder 8. A mirror housing (not shown) is attached to the mirror holder 8, and a mirror (not shown) and an actuator (not shown) for tilting and driving the mirror left and right and up and down are attached to the mirror housing. Reference numeral 11 denotes a washer interposed between the base plate 1 and the mirror holder 8, and has an operation of smoothing the rotation of the mirror holder 8.

Reference numeral 12 denotes an upper part of the mirror holder 8,
A circular ring-shaped main gear rotatably fitted to the large diameter portion 3 of the main shaft 2 via the washer 13 with respect to the main shaft 2, an inner upper portion is hollowed out in a circular shape, and a bottom surface of the hollowed portion 14 is formed. Trapezoidal clutch claw 15
Are formed at equal intervals. 16 is the main gear 1
In the upper part of the clutch 2, a circular ring-shaped clutch fitted in the intermediate region 5 of the main shaft 2 is formed with four grooves 17 for engaging with the ridge 6 at equal intervals.
Therefore, the clutch 16 is fitted to the main shaft 2 so as not to rotate and move vertically. Reference numeral 18 denotes four trapezoidal clutch grooves formed on the lower surface of the clutch 16, which engage with the clutch claws 15 of the main gear 12. The clutch 16 is connected to the main gear 12
It is formed in a size to be accommodated in the hollow portion 14. The main gear 12 is formed of a sintered metal, and the clutch 16 is formed of a reinforced nylon resin described later.

Reference numeral 19 denotes a coil spring fitted on the main shaft 2 above the clutch 16, and its upper end is mounted in a state compressed by a push nut 20 fixed to the upper end of the main shaft. Therefore, the clutch 16, the main gear 12, and the mirror holder 8 are constantly biased from above by elastic pressure. The portion formed one step thinner above the ridge 6 functions as a spacer for positioning the coil spring 19 at a predetermined interval with respect to the main shaft 2.

Reference numeral 21 denotes a steel worm gear formed by cutting or rolling, and intersects the main gear 12 at 90 degrees. This worm gear 21
Has a function of preventing transmission of the rotational force applied from the main gear 12, and its advance angle is set to about 8 degrees or less, preferably about 4 degrees. If the advance angle is this angle, even if a force for rotating the worm gear 21 is applied from the main gear 12 to the worm gear 21, the worm gear 21 does not rotate in conjunction therewith. The advance angle refers to the angle of the tooth with respect to the direction perpendicular to the axis of the worm gear.

Reference numeral 22 denotes a forward / reverse rotation motor; 23, a top gear, that is, a spur gear fixed to the rotation shaft of the motor 22;
26 are two spur gears 24a and 24b, 25a and 25b, 26a and 2
The first, second, and third double gears 27 and 27 are a screw gear 27 b and a fourth double gear 27 and a spur gear 27 a having a larger diameter, and 28 is a screw gear formed coaxially with the worm gear 21. is there.

The motor shaft spur gear 23 is a first double gear 24
The small diameter gear 2 of the first double gear 24
4b is a large diameter gear 25a of the second double gear 25, a small diameter gear 25b of the second double gear 25 is a large diameter gear 26a of the third double gear 26, and a small diameter gear 26 of the third double gear 26.
b meshes with the large diameter gear 27a of the fourth double gear 27, and the small diameter screw gear 27b of the fourth double gear 27 meshes with the screw gear 28, respectively. The rotational force of the motor 22 is sequentially transmitted to the lower gears as described above. The shaft 29 of the fourth double gear 27 and the shaft 30 of the worm gear intersect at 90 degrees, the second double gear 25 is fixed to the shaft 29, and the first and third double gears 24 and 26 are fixed to the shaft 31. I have. The axes of the shafts 29, 31 and the motor 22 are in the same direction.

In this structure, when the motor 22 is turned on, the rotational force is reduced by the gear 23 and the first to fourth double gears 24, 25, 26, 27, and the screw gear 2
8, transmitted to the main gear 12 via the worm gear 21, and the door mirror rotates at an appropriate speed.

Here, a gear group between the worm gear 21 and the motor 22, that is, the gear 23, the first to fourth double gears 24, 25, 26, 27, and the screw gear 28 are formed of resin. As the resin material, a polyacetal resin reinforced by mixing potassium titanate whisker, glass fiber, carbon fiber, or the like, or a nylon resin mixed with the above-described reinforcing material is used.

Next, the operation of the above structure will be described. In a normal operation, that is, a rotation operation from the storage position to the use position or the reverse direction, the rotation force of the motor 22 causes the rotation force to be changed to the spur gear 23, the first to fourth double gears 24,
The speed is reduced via the gears 25, 26, 27, the screw gear 28, and the worm gear 21 and transmitted to the main gear 12. Since the main gear 12 is engaged with the clutch 16, a rotational force is applied thereto. Since the clutch 16 is supported so as not to rotate with respect to the main shaft 2, the clutch 16 attempts to rotate the main shaft 2. However, since the main shaft 2 is fixed to the vehicle body via the base plate 1, it does not rotate, and conversely, the motor 22 side, that is, the entire mirror holder 8 rotates about the main shaft 2.

This rotation range is regulated by position regulating means. That is, as shown in FIG. 4, the mirror holder 8 rotates with the rotation of the motor 22, and the groove 10 is
When the projection reaches the left end of the groove 10 as shown by the solid line (represented by a) and reaches the use position, and the projection 7 hits the right end of the groove 10 as shown by the dashed line. (B
(Represented by) and stops. The driving force by the motor 22 is set to be smaller than the force with which the protrusion 7 engages with the groove 10, and therefore, the protrusion 7 does not ride on the outside of the groove 10 and further rotates. The positional relationship between the projection 7 and the both ends of the groove 10 is set so that an appropriate use position and storage position of the mirror holder 8 can be obtained. Thus, the forward / reverse rotation of the motor 22 causes the door mirror to rotate from the use position to the storage position and from the storage position to the use position.

When the door mirror rotates and reaches, for example, the use position, the projection 7 hits the left end of the groove 10 (FIG. 4),
It stops with this pressed. In this state, the motor 22
Is turned off, and the rotational power of the gear group is released. At this time, only the worm gear 21 is locked at the released position, and fixes the main gear in a state where the convex portion 7 presses the left end of the groove 10. That is, the reaction force of the above pressing force (the convex portion 7 is
(Ie, a force that causes the main gear 12 to rotate in the reverse direction) is applied to the worm gear 21, but the worm gear 21 does not rotate in the reverse direction against this force. The same applies to the storage position. On the other hand, the gear 23 in the released state, the first to fourth double gears 24 and 25,
The screw gears 26 and 27 and the screw gear 28 are in an open state where they can rotate in the forward and reverse directions, and no stress is applied to them.

When an obstacle collides with the door mirror and a sudden external force is applied thereto, a strong rotational force is applied to the main gear 12 and the clutch pawls 15 of the main gear 12 are rotated.
However, since the clutch 16 is in contact with the clutch groove 18 of the clutch 16 on the inclined surface, the clutch 16 is pushed upward against the pressing force of the coil spring 19, the engagement with the clutch 16 is released, and the main gear 12 is released. You will be able to rotate freely. At the same time, the projection 7 of the base plate 1 comes off the groove 10 of the mirror holder 8, and the mirror holder 10 can freely rotate. Thus, when a sudden external force is applied to the door mirror from the front or the rear, the door mirror also turns suddenly backward or forward.

In the above structure, a spur gear and a screw gear are used as reversible gears in a group of gears between the motor 22 and the worm gear 21, but the lead angle of the worm gear is set to, for example, 10 degrees or more. Then, the worm gear can be reversely rotated by receiving the rotational force from the lower gear, so that the worm gear having such a structure can be used as one of such gear groups.

[0022]

According to the present invention, in order to stop the door mirror at the use position or the storage position, only the gear meshing with the main gear uses a worm gear for preventing transmission of the rotational force from the main gear, and the other gears are used. Since a gear that rotates by the rotational force from the lower gear is used, no rotational force is applied to the gear group between the worm gear and the motor except when the door mirror is rotated. Since the drive period of the gear group is much shorter than the rotational force release period, deformation, distortion, and breakage due to stress of the gear group between the worm gear and the motor can be minimized. Therefore, these gear groups conventionally formed of metal can be replaced with resin, and miniaturization and weight reduction can be achieved.

Further, according to the present invention, a normal worm gear, that is, a worm gear having a relatively small advance angle can be used as the worm gear for preventing the transmission of the rotational force from the main gear, so that a special mechanism is not used. The structure is simple and the cost can be kept low.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an automobile door mirror device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the door mirror device according to one embodiment of the present invention.

FIG. 3 is a sectional view of a door mirror device.

FIG. 4 is a sectional view showing a position regulating unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base plate 2 Main shaft 3 Large diameter part 4 Small diameter part 5 Intermediate area 6 Ridge part 7 Convex part 8 Mirror holder 9 Opening 10, 17 Groove 11, 13 Washer 12 Main gear 14 Cut-out part 15 Clutch 16 Clutch 18 Clutch groove 19 Coil spring 20 Push nut 21 Worm gear 22 Motor 23 Spur gear 24, 25, 26, 27 First, second, third, fourth double gear 28 Screw gear 29, 30, 31 Shaft

Claims (1)

[Claims] A base plate formed so as to protrude substantially horizontally outside a vehicle body of a front door, a main shaft substantially vertically supported by the base plate, a mirror holder rotatably supported by the main shaft; A main gear fitted to the main shaft and rotating the mirror holder, and a motor for applying a rotating power to the main gear;
A gear group interposed between the motor and the main gear for transmitting a driving force and having a deceleration function, and a gear group on the vehicle body side and the mirror holder side when a large force is suddenly applied to the mirror holder side. In the automotive door mirror device comprising a clutch for releasing the coupling, only the gear that meshes with the main gear of the gear group is constituted by a worm gear that prevents transmission of rotational force applied from a lower gear, and the worm gear A group of gears between the motor and the motor is constituted by gears for transmitting a rotational force applied from a lower stage.