JP3420783B2 - Drive mechanism of retractable door mirror - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for rotationally driving a visor, which is a housing of a mirror body in a door mirror, between a use position in which it is erected from a vehicle body and a storage position in which it is tilted to the vehicle body side. In particular, it relates to a drive mechanism using an ultrasonic motor as a drive source.

[0002]

2. Description of the Related Art Generally, a retractable door mirror is composed of a visor for holding a mirror body and a stay for attaching the visor to a door. A drive mechanism using an ultrasonic motor as a drive source for rotational drive in this type of retractable door mirror is proposed in, for example, Japanese Patent Application Laid-Open No. 62-94444. In this drive mechanism, a ring-shaped traveling-wave ultrasonic motor composed of a rotor and a stator is arranged around a fulcrum shaft provided in the stay so that one of the rotor and the stator is on the stay side and the other is on the other side. Is attached to the visor side, and the visor is rotated by the rotation of the rotor during energization.

[0003]

However, in this configuration, the space in which the ultrasonic motor can be arranged in the visor is limited to a comparatively small range, and the ultrasonic motor that can be used is necessarily of a comparatively small diameter. Limited, it is difficult to obtain sufficient torque to drive the visor.
Further, the ultrasonic motor has a feature that it can be rotated at a lower speed than the electromagnetic motor, but even if it is directly connected to the visor as a drive source of the door mirror, there is a problem that the rotation speed of the visor becomes too fast. Therefore, it is conceivable to provide a deceleration means in order to obtain a sufficient torque and an appropriate operation speed for driving the visor, but in that case, the drive mechanism may be upsized, and thereby the door mirror itself may be upsized.

Therefore, a technical problem to be solved by the present invention is to provide a drive mechanism using an ultrasonic motor, which is provided with a speed reduction means suitable for a small installation space.

[0005]

In order to solve the above-mentioned technical problems, the drive mechanism of the retractable door mirror according to the present invention is basically constructed as follows. That is, the drive mechanism of the retractable door mirror has a stator and a rotor, the ultrasonic motor rotating the rotor around the rotation center of the visor, and the first annular ring connected to either the stator or the rotor. A second ring member connected to the other one of the stator and the rotor, and the first ring member and the second ring member rotate about the center of rotation of the visor while interlocking with each other, The visor is provided with deceleration means for decelerating the rotational speed of the ultrasonic motor by the difference in the number of revolutions between the first annular member and the second annular member.

In the above structure, when the ultrasonic motor is activated to generate the rotational force in the rotor, the rotational force is transmitted to the second annular member connected to the rotor. The first annular member associated with the second annular member rotates. Therefore, the first
With the rotation of the annular member, the visor rotates about the rotation center of the ultrasonic motor. At this time, the rotation of the ultrasonic motor is delayed because the first annular member lags behind the second annular member due to the difference in the number of rotations between the first annular member and the second annular member. Thus, it is possible to rotate the visor at a lower speed than to directly rotate the visor, and it is possible to increase the torque accompanying the low speed rotation.

The speed reducing means is disposed between the outer ring as the first annular member, the inner ring as the second annular member, the outer ring and the inner ring, and is rotatably held by the member on the stay side. And a moving body.

According to the above construction, when the ultrasonic motor is activated to generate the rotational force in the rotor, the rotational force is transmitted to the rolling elements via the inner ring. Therefore, since the rolling element rotates, the outer ring rotates. Therefore, the visor rotates around the rotation center of the ultrasonic motor as the outer ring rotates. At this time, since the rotation of the outer ring of the bearing lags behind that of the inner ring by the difference in diameter, it is possible to rotate the visor at a lower speed than the direct rotation of the visor by the rotation of the ultrasonic motor, and also to increase the torque accompanying the low speed rotation. it can.

In this structure, the speed reducing means is constituted by a bearing using a ball or a cylindrical roller as the rolling element, or a planetary gear is used as the rolling element and a gear meshing with the inner ring and the outer ring is formed. The planetary gear mechanism can be used as a speed reducer.

The deceleration means is arranged between the outer ring as the first annular member, the inner ring as the second annular member, the outer ring and the inner ring, and is rotatably held by the member on the stay side. When the rotor is rotated, a part of the external gear is always meshed with the internal gear.

In this structure, when the ultrasonic motor is started, first, the eccentric cam rotates together with the rotor. Along with the rotation of the eccentric cam, the second annular member swings in the first annular member while rotating. At this time, the meshing position between the external gear and the internal gear changes, so that the second annular member rotates, which causes the visor to rotate. With this configuration, the visor can be rotated at a lower speed than in the above configuration, and a larger drive torque can be obtained.

Further, the speed reducing means includes a first annular member having an internal gear and a second annular member engaging with an eccentric cam connected to the rotor and having an external gear having a smaller number of teeth than the internal gear. The second annular member is held by the stay-side member so as to be displaceable by the eccentric amount of the eccentric cam, and the external gear is always meshed with the internal gear during displacement in all directions. ing.

In this structure, when the ultrasonic motor is activated, first, the eccentric cam rotates together with the rotor. As the eccentric cam rotates, the second annular member sways within a movable range defined by the eccentric amount of the eccentric cam. At this time, since the position of the external gear gradually changes, the meshing position between the external gear and the internal gear changes, the first annular member rotates, and the visor rotates accordingly. Also in this configuration, the visor can be rotated at a lower speed, and a larger drive torque can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A retractable door mirror having a drive mechanism according to an embodiment of the present invention shown in FIGS. 1 to 6 will be described in detail below.

First, the first embodiment shown in FIGS. 1 and 2 will be described. FIG. 1 is a schematic configuration diagram of this door mirror, and FIG. 2 is an enlarged sectional view taken along line II-II of FIG. In the figure, 1 is a stay fixed to the door of the vehicle body, 2 is a visor as a casing of the mirror body 3, and 4 is a stay 1.
It is a base plate fixed to. Reference numeral 5 denotes a bracket fixed to the visor 2, which holds the mirror body 3 via an angle adjusting mechanism (not shown).

The base plate 4 has a through hole 4a at a position corresponding to the center of rotation of the visor 2, and a retainer 6 is fixed to the through hole 4a. The retainer 6 has a flange 6a at one end, which is a cage (not shown) for holding the balls 7a of the ball bearing 7 at regular intervals.
Has been fixed. The inner ring 7b of the ball bearing 7 is fitted to the first sleeve 8, and the outer ring 7c is fitted to the cylindrical boss 5a formed on the bracket 5, and the boss 5a and the first sleeve 8 are relatively arranged. It can be rotated.

Reference numeral 9 denotes a ring-shaped traveling wave type ultrasonic motor. The ultrasonic motor 9 includes a stator 9a and a rotor 9b.
Although not shown in detail, the stator 9a is composed of an elastic ring and a piezoelectric element attached to its upper surface in the figure. Also, the rotor 9b
Are pressed against the lower surface of the elastic ring. In this ultrasonic motor 9, traveling waves are generated on the surface of the stator 9a by applying voltages having 90 ° phases different from each other to the opposing electrodes provided separately in the piezoelectric element, and the rotor 9b is generated when the traveling waves are generated. It is driven to rotate by frictional force.

The inner peripheral edge of the rotor 9b of the ultrasonic motor 9 is fixed to the upper end of the first sleeve 8, and the stator 9b
A second sleeve 10 is fixed to the inner peripheral edge of a so as to be located concentrically with the first sleeve 8. On the other hand, the ball bearing 7, the ultrasonic motor 9 and the sleeves 8 and 10
The fixing plate 11 is attached to the upper end of the boss 5a that accommodates the second sleeve 10 at a slight distance. A disc spring (urging means) 12 is arranged between the fixed plate 11 and the second sleeve 10, and the stator 9a and the rotor 9b of the ultrasonic motor 9 are in pressure contact with each other due to the urging force. The disc spring 12 is on the side of the fixed plate 11 and the second sleeve 1.
The 0 side is also provided with a rotation stop, which restricts the rotation of the second sleeve 10 with respect to the boss 5a.

On the other hand, the reference numeral 13 in FIG.
This is a drive unit of the ultrasonic motor 9. Each of the retainer 6, the first sleeve 8, the second sleeve 10, and the fixing plate 11 described above has a through hole at the center as shown in the drawing, and electrical wiring from the vehicle body side to the drive unit 13 is performed through these holes. ing. Ultrasonic motor 9
Are electrically connected to the drive unit 13 inside the visor 2.

In the drive mechanism of this embodiment, when the ultrasonic motor 9 is started, the traveling wave generated on the surface of the stator 9a produces a force that causes the rotor 9b to rotate relative to the stator 9a. This rotational force is transmitted to the ball 7a via the first sleeve 8 and the inner ring 7b of the ball bearing 7. Since the ball 7a is held by the cage fixed to the retainer 6, it does not revolve, but only rotates on the spot. When the ball 7a rotates, the outer ring 7c rotates due to the frictional force with the ball 7a. Therefore, with the rotation of the outer ring 7c, the bracket 5 rotates about the rotation center of the bearing 7, and at the same time, the visor 2 also rotates. At this time, the outer ring 7c of the bearing 7 is
The rotation is delayed with respect to the inner ring 7b by the diameter difference.

As described above, according to this embodiment, it is possible to rotate the ultrasonic motor 9 to rotate the visor 2 at a lower speed than to directly rotate the visor 2, and it is possible to increase the torque accompanying the low speed rotation. Further, since the bearing 7 is used as the deceleration means, it is possible to prevent the mechanism from being significantly increased in size, and the drive mechanism can be constructed at an extremely low cost. Although the position of the ball 7a is fixed in this embodiment,
The ball 7a may be revolvable by fixing the inner ring 7b.

Next, a second embodiment using a harmonic gear shown in FIGS. 3 and 4 will be described. FIG. 3 is a central longitudinal cross-sectional view of this storage mechanism, and FIG. 4 is IV- of FIG.
FIG. 4 is a sectional view taken along line IV.

The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, a fulcrum shaft 14a is formed on the base plate 14, and an eccentric cam 18 is rotatably mounted on the fulcrum shaft 14a. The eccentric cam 18 is
The sleeve 10 fixed to the rotor 9b of the ultrasonic motor 9 and fixed to the stator 9a is axially movable with respect to the fulcrum shaft 14a and is held in a state in which the rotation is restricted. On the other hand, the boss (first annular member) 15 of the bracket 15
An internal gear 15b is formed on the inner peripheral surface of a, the number of teeth between the eccentric cam 18 and the boss 15a is smaller than that of the internal gear 15b, and some of the teeth are always meshed with the internal gear 15b. An annular body (second annular member) 17 having a gear 17a is inserted. It should be noted that each of the gears 15b and 17a is shown with only some of the teeth for the sake of simplicity of the drawing.

In this embodiment, when the ultrasonic motor 9 is activated, first, the eccentric cam 18 rotates together with the rotor 9b. With the rotation of the eccentric cam 18, the external gear 17a swings in the internal gear 15b while rotating. Therefore,
The boss 15a rotates, which causes the visor to rotate. According to this embodiment, the visor can be rotated at a lower speed and a larger drive torque can be obtained as compared with the first embodiment. Further, also in this embodiment, since the speed reducing means is arranged coaxially with the ultrasonic motor 9,
It is possible to prevent the mechanism from significantly increasing in size.

Next, a third embodiment utilizing the constant velocity internal gear mechanism shown in FIGS. 5 and 6 will be described. FIG. 5 is a central longitudinal sectional view of this storage mechanism, and FIG. 6 is VI-VI of FIG.
It is a line sectional view.

Also in the present embodiment, the same components as those in the above-mentioned embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the base plate 24 is formed with six shafts 24 a located around the rotation center of the visor 2. Further, as in the second embodiment, the eccentric cam 28 is fixed to the inner peripheral edge of the rotor 9b of the ultrasonic motor 9. An annular body (second annular member) 27 is mounted around the eccentric cam 28, and has a hole 27a formed in the annular body 27 (having a diameter larger than the diameter of the shaft 24a by the amount of eccentricity of the eccentric cam 28). Shaft 24a is inserted into the shaft. A gear 25b along the epitrochoid curve is formed on the inner circumference of the boss (first annular member) 25a, and a gear 27b also along the epitrochoid curve is formed on the outer circumference of the annular body 27 with fewer teeth than on the boss 25a side. It is made up of numbers. Each gear 25b, 27b shows only part of its teeth, as in the second embodiment.

In this embodiment, when the ultrasonic motor 9 is activated, first, the eccentric cam 28 rotates together with the rotor 9b. As the eccentric cam 28 rotates, the annular body 27 moves to the shaft 2
It swings within the movable range defined by the gap between 4a and hole 27a. At this time, since the position of the external gear 27b of the annular body 27 changes little by little, the meshing position of the external gear 27b and the internal gear 25b changes, the boss 25a rotates, and the visor rotates accordingly. Also in this configuration, the visor can be rotated at a lower speed than in the first embodiment, and a larger drive torque can be obtained. Further, since the speed reducing means is arranged coaxially with the ultrasonic motor as in the second embodiment, it is possible to prevent the mechanism from increasing in size.

Further, in each of the above-mentioned embodiments, since all the speed reducing means are formed in an annular shape, there is an advantage that the wiring from the vehicle body to the visor can be passed through the drive mechanism.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a door mirror including a storage mechanism according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a central longitudinal sectional view of a storage mechanism according to a second embodiment.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a central longitudinal sectional view of a storage mechanism according to a third embodiment.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

1 stay 2 visor 3 mirror body 4 base plate 5 bracket 5a boss 6 retainer 7 ball bearing 7a ball 7b inner ring 7c outer ring 8 first sleeve 9 ultrasonic motor 9a stator 9b rotor 10 second sleeve 11 fixing plate 12 disc spring (biasing means) ) 13 drive unit 14 base plate 14a fulcrum shaft 24a shaft 15,25 bracket 15a, 25a boss
(First annular member) 15b, 25b Internal gear 17,27 Annular body (Second annular member) 17a, 27b External gear 27a Hole 18,28 Eccentric cam

Continuation of the front page (56) Reference JP-A-62-94444 (JP, A) JP-A-3-159832 (JP, A) JP-A-62-77257 (JP, A) Actual Kaihei 3-118843 (JP , U) Actual flat 4-93232 (JP, U) Actual flat 3-118844 (JP, U) Actual flat 1-114454 (JP, U) Actual 62-56346 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60R 1/06 B60R 1/074 H02N 2/00

Claims (4)

(57) [Claims] 1. A mechanism for rotationally driving a visor (2) holding a mirror body (3) by a retractable door mirror with respect to a stay (1) fixed to a vehicle body, the stator (9a) and a rotor. (9b), and the rotor (9b) is an ultrasonic motor (9) which rotates about the center of rotation of the visor (2)
And a first annular member (7c; 15a; 25a) connected to either the stator (9a) or the rotor (9b) and the other of the stator (9a) or the rotor (9b). Second annular member
(7b; 17; 27), and the first circular ring member (7c; 15a; 25a) and the second circular ring member (7b; 17; 27) are linked to each other and center around the rotation center of the visor (2). To the first ring member (7c; 15
a; 25a) and the second annular member (7b; 17; 27) by the difference in the number of revolutions, the deceleration means (7; 15a, 17,17,17,17,17) for decelerating the rotational speed of the ultrasonic motor (9). 18; 25a, 27, 28, 24a) are provided in the visor (2), the drive mechanism for the retractable door mirror. 2. The reduction means (7) comprises an outer ring (7c) as a first annular member, an inner ring (7b) as a second annular member, an outer ring (7c) and an inner ring (7b). Disposed between the stays
The drive mechanism for a retractable door mirror according to claim 1, characterized in that the drive mechanism comprises a rolling element (7a) rotatably held by the member (4) on the (1) side. 3. The reduction means (15a, 17, 18) engages a first annular member (15a) having an internal gear (15b) and an eccentric cam (18) connected to a rotor (9b). And a second annular member (17) having an external gear (17a) having a smaller number of teeth than the internal gear (15b), and when the rotor (9b) rotates, a part of the external gear (17a) 2. The drive mechanism for the retractable door mirror according to claim 1, wherein the drive mechanism is always meshed with the internal gear (15b). 4. The speed reducing means (25a, 27, 28, 24a) engages a first annular member (25a) having an internal gear (25b) and an eccentric cam (28) connected to a rotor (9b). And a second annular member (27) having an external gear (27b) which has a smaller number of teeth than the internal gear (25b), and the second annular member (27) is an eccentric cam (28). ) Is held by the member (24) on the stay (1) side so as to be displaceable by an eccentric amount, and the external gear (27b) always meshes with the internal gear (25b) during displacement in all directions. Claim 1 characterized by the fact that
Drive mechanism for the retractable door mirror described.