JPH069903Y2 - Outer mirror for automobile - Google Patents

Description

[Detailed Description of the Invention] Industrial Application The present invention relates to an automobile outer mirror, and
The present invention relates to improvement of a tilting mechanism of a mirror holder for supporting a mirror body.

2. Description of the Related Art Conventionally, various types of outer mirrors have been known as this type of outer mirror. As a general-purpose one, for example, a mirror main body is supported by a mirror holder, the center of the mirror holder is tiltably supported by a casing of a mirror case, and the casing fixed in the mirror case is used. A mirror holder is provided with an operation shaft whose tip is pivotally mounted, and a cylindrical drive gear is externally fitted and meshed with an outer peripheral portion of a portion of the operation shaft located in the casing. There is a type in which a drive gear is rotated to move the operation shaft back and forth in the axial direction to freely tilt the mirror holder with respect to the mirror case, that is, the casing. In such a mirror holder, it is necessary to support the drive gear on the casing so that the drive gear smoothly rotates with respect to the casing and that the casing does not rattle when the vehicle is traveling. For this reason, as shown in FIG.
The casing including 5 is composed of an upper casing 21 and a lower casing 22. The lower casing 22 has a recess 22a formed in its inner surface, and the upper end of the cylinder of the drive gear 23 is rotatably fitted in the recess 22a. On the other hand, the upper casing 21 has a recess 21a formed at the lower end of the inner surface thereof, and an annular spring member 24 is housed in the recess 21a so that the lower end of the drive gear 23 is recessed.
The drive gear 23 is rotatably fitted to a and is pressed by the biasing force of the spring member 24 toward the lower casing side so as to allow the drive gear 23 to rotate and reduce the rattling of the drive gear with respect to the casing. I have to.

However, in the structure described above, since the biasing force of the spring member acts along the axial direction of the drive gear, if the biasing force of the spring member is too large, the rotation loss of the drive gear will be lost. Therefore, the magnitude of the urging force applied to the drive gear is naturally limited, and it has not been possible to sufficiently solve the looseness of the drive gear.

Therefore, an object of the present invention is to solve the above problem, and even if the rotation loss of the drive gear is the same as the conventional one, it is possible to more effectively prevent the backlash of the drive gear. To provide.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention has a lower end portion of a drive gear having a conical shape, and an inclined surface of the lower end portion of the casing along a direction orthogonal to the axis of the drive gear. The supporting portion is configured to be pressed and supported. That is, the drive gear is
At its lower end, there is a lower conical portion having an inclined surface whose outer surface is tapered downward, and at the lower part of the casing, the base end is fixed to the casing and the protruding end is the lower conical part of the drive gear. A plurality of pressure contact portions that are elastically pressure-contacted to the inclined surface of the portion along the direction orthogonal to the axis of the drive gear to support the drive gear and that are slidable with respect to the inclined surface and are annularly arranged; A recess, into which the upper end of the drive gear is rotatably fitted, is formed on the inner surface of the upper portion of the casing so as to restrict the movement of the drive gear toward the mirror body in the axial direction.

Effect of the Invention In the above configuration, the pressure contact portion of the casing is pressed against the inclined surface of the lower end portion of the drive gear in the direction orthogonal to the axis of the drive gear to support the drive gear, and the drive gear is rotated by the drive of the drive device. At this time, the press contact portion slides on the inclined surface of the lower end portion of the drive gear and applies an urging force along the axis orthogonal direction to the drive gear to constantly press the drive gear to the inner surface of the upper portion of the casing. More effectively prevent rattling in the casing of.

Embodiment An embodiment according to the present invention will be described in detail below with reference to FIGS.

The outer mirror for a vehicle according to the present embodiment includes the first and second outer mirrors.
As shown in the figure, a mirror holder 1 supporting a mirror body (not shown) is supported by a mirror case (not shown) so as to be tiltable around a horizontal tilt central axis and a vertical tilt central axis, and Predetermined places on the back side, that is, a pair of mounting parts
Heads 1a, 1a of the pair of mirror holder push-pull operation shafts 4, 4 4b, 4b
Are attached so as not to be detachable along the axial direction, respectively, and the operation shafts 4 are provided in the casings 5 and 8 of the mirror case so as to be able to go in and out through the openings 5a, and the casings 5 and 8 are also provided.
Drive gears 7 are mounted in the casings 5 and 8 so as to be axially immovably and rotatably supported, and further fitted to and meshed with the outer peripheral portions of the operation shafts 4, respectively, to drive the drive devices in the casings 5 and 8. To rotate the drive gears 7 to move the operation shafts 4 back and forth along the axial direction.
Is tilted with respect to the mirror case to adjust the tilt of the mirror body.

The mounting portion 1a on the back surface of the mirror holder 1 is formed of a spherical concave portion, and the mirror holder 1 is tiltable about a horizontal tilt central axis and a vertical tilt central axis passing through the rotation center O thereof.

Each operation shaft 4 has a thin neck portion 4c and a spherical head portion 4b integrally formed along the axial direction at the tip of a leg portion 4a. Above head 4b
Is rotatably fitted to and supported by the mounting portion 1a of the mirror holder 1. The leg portion 4a has a thread formed on the outer peripheral surface thereof, and a concave portion 4d having a circular cross section with a small diameter and extending from the rear end portion end surface toward the head portion 4b along the substantially axial direction to the vicinity of the thin neck portion. To do.

Further, a lower casing 5 and the lower casing 5 are provided in a mirror case that tiltably supports the mirror holder 1.
Upper casing 8 engaging with
A part of the operation shaft 4, a drive device for the operation shaft 4, and the like are housed in the insides of 5, 8.

The lower casing 5 is formed with a through hole 5a having a diameter dimension larger than the outer diameter of the leg portion 4a of the operation shaft 4, and the leg portion 4a of the operation shaft 4 is axially arranged in the through hole 5a. To be freely movable and relatively tiltable.

On the other hand, the upper casing 8 is provided with two storage portions 8a which are recessed downward in FIG.
As shown in FIG. 2, in the opening portion of 8a, three support walls 8d, 8d, 8d having an annular cross-section at predetermined intervals and the support walls 8d, 8d are provided.
The pressure contact portions 8c are formed so as to protrude between d. Therefore, the press contact portion 8c and the support wall 8d are positioned so as to face the center of each storage portion 8a. A recess is formed inside the upper end of each support wall 8d.
Forming 8e. The storage portion 8a of the upper casing 8
A flexible guide protrusion 8b that protrudes toward the lower casing is formed at the center of the bottom of the. The guide protrusion 8b is configured so that its axis is eccentric with respect to the axis of the recess 4d of the operation shaft 4, and the outer diameter of the guide protrusion 8b is smaller than the inner diameter of the recess of the operation shaft 4. The guide protrusion 8b is fitted in the recess 4d of the leg 4a of the operation shaft 4 so as to be constantly in contact with the inner peripheral surface of the recess and relatively slidable and tiltable in the substantially axial direction. Thus, the movement of the operation shaft 4 in the substantially axial direction can be smoothly guided, and the frictional force between the operation shaft 4 and the guide protrusion 8b can prevent the operation shaft 4 from rattling.

Each drive device includes a drive motor (not shown) and a cylindrical drive gear 7 connected to the drive motor and externally fitted to the operation shaft 4. That is, in the drive gear 7, the lower end conical portion 7a formed on the upper casing side so as to project in the circumferential direction is rotatably fitted to the recesses 8e of the support walls 8d of the upper casing 8, and The pressure contact portion 8c is slidably pressed against the inclined surface 7b of the lower end conical portion 7a of the drive gear 7 to press the drive gear 7 toward each support wall 8d to position the drive gear 7. On the other hand, the upper end of the drive gear 7 is an inner surface concave portion of the lower casing 5 on the upper casing side.
5b is rotatably fitted. Therefore, the drive gear 7 is supported between the casings 8 and 5 to prevent the rattling and guide the rotation thereof. Axial through hole 7c at the center of the drive gear 7
The leg portion 4a of the operating shaft 4 is fitted therein, and the spring arm 7d attached to the inner surface of the through hole 7c is engaged with the external thread of the leg outer peripheral surface of the operating shaft 4 to drive the operating shaft 4. The gear 7 should not move freely in the axial direction of the operation shaft. Therefore, when the drive gear 7 rotates between both casings 5 and 8,
Since the drive gear 7 cannot move in the axial direction of the operation shaft with respect to the mirror case, the operation shaft 4 connected by the spring arm 7d moves back and forth substantially in the axial direction. In FIG. 1, reference numeral 2 denotes a rubber simple waterproof cap, which substantially seals the gap 3 between the operation shaft 4 and the opening 5b of the lower casing 5.

The outer mirror according to the above-described configuration is configured such that the drive gears 7 and the drive motors (not shown) are inserted into the casings 5 and 8 of the mirror case to incorporate the operation shafts 4 into the drive gears 7 and The head 4b of the operation shaft 4 is fitted to each mounting portion 1a of the mirror holder 1 so as to prevent the head 4b from slipping off from the casing side and assembled so as to freely tilt with respect to the mirror holder 1. .

The outer mirror having the mirror holder 1 assembled in the casings 5 and 8 of the mirror case in this manner operates as follows. That is, when the drive motor is driven, the drive gear 7 rotates, and the leg portion 4a of the operation shaft 4 moves back and forth substantially along its axial direction. At this time, when the mirror holder 1 is pushed by the operation shaft 4, the head 4b of the operation shaft 4 pushes the mounting portion 1a of the mirror holder 1 to move the mirror holder 1 to the horizontal tilt central axis or the vertical tilt central axis with respect to the mirror case. Tilt around either or both axes. When pulling the mirror holder 1 with the operation shaft 4, the head 4b of the operation shaft 4 pulls the mounting portion 1a of the mirror holder 1 to the casing side to move the mirror holder 1 horizontally or vertically with respect to the mirror case. Tilt around one or both of the central axes. The drive gear 7 has the three pressure contact parts 8
It is supported between c, 8c, 8c and the three support walls 8d, 8d, 8d and the recess 5b of the lower casing 5, and smoothly rotates around the axis. The force (see “Fh” in FIG. 4) exerted by the press contact portion 8c on the drive gear 7 through the inclined surface 7b is a direction orthogonal to the axial direction due to the inclination angle θ of the inclined surface 7b. Is decomposed into and. Then, the force acting on the axial mirror body side (force in the direction opposite to P _{1 in} FIG. 4) is received by the recess 5b of the lower casing 5, and the drive gear 7 tries to move to the mirror body side. On the other hand, the force acting in the direction orthogonal to the axis is offset by the plurality of pressure contact portions 8c evenly arranged on the circumference of the drive gear 7. The mirror holder 1
When the mirror holder 1 is tilted, the operation shaft 4 is attached to the casings 5 and 8 of the mirror case and the drive gear 7 so as to be tiltable and movable substantially along the axial direction. The head portion 4b tilts with respect to the mirror holder 1 in the mounting portion 1a, and also slightly tilts with respect to the casings 5 and 8 and the drive gear 7. In FIG. 1, the alternate long and short dash line shows the state where the operating shaft 4 is most retracted to the bottom of the storage portion 8a of the upper casing 8, and the dotted line shows the state where the operating shaft 4 is most advanced from the storage portion 8a.

According to the above-described embodiment, the pressure contact portion of the upper casing 8 is
The biasing force of 8c, 8c, 8c is applied to the inclined surface of the lower conical portion 7a of the drive gear 7.
The drive gear 7 is acted on the drive gear 7 in a direction orthogonal to the axis so as not to hinder the rotation of the drive gear 7 so much that the components of the urging force acting on the drive gear 7 from the pressure contact portions 8c together drive the drive gear 7 to the lower casing. Since it is pushed to the side, the drive gear 7 can be pushed to the lower casing side by the large biasing force of the pressure contact portion 8c as compared with the conventional outer mirror, and the backlash of the drive gear 7 can be prevented more effectively. You can Also,
Since the pressure contact portion 8c is formed integrally with the upper casing 8, it is not necessary to assemble a special member to press the drive gear 7 toward the lower casing. Further, since the drive gear 7 is pressed by the pressure contact portion 8c in the direction orthogonal to the axis, the drive gear 7
Since it is not necessary to position the pressure contact portion 8c at any one of the upper and lower portions in the axial direction, the dimension of the drive gear insertion portion along the axial direction can be made smaller.

Here, the effect of preventing rattling of the drive gear between the outer mirror of the above embodiment and the conventional outer mirror will be compared. As shown in FIGS. 3, 4, 7, and 8, the force acting downward along the axial direction of the drive gear 7 of the outer mirror according to the above embodiment, that is, the inserting force of the operating shaft 4 is P ₁ , and the pressure contact portion 8c is When the inclined surface 7b of the lower end conical portion 7a of the drive gear 7 abuts and the pressure contact portion 8c bends slightly, the biasing force acting on the lower end conical portion 7a of the drive gear 7 from the pressure contact portion 8c is Fh. The angle between the inclined surface 7b of the lower end conical portion 7a of 7 and the axial direction is θ, while the downward force along the axial direction acting on the drive gear of the conventional outer mirror, that is, the inserting force of the operating shaft is shown in FIG. As shown, P ₂ , and the coefficient of static friction is μ (= 0.
318), each insertion force is P ₁ = (sin θ + μcos θ) · Fh / (cos θ−μsin θ) =
0.708 · Fh, ∴Fh = 1.412 / P ₁ , P ₂ = Fv.

On the other hand, the loss due to the friction of the rotational torque of the drive gear is Tc ₁ = μ · [(sin θ−μ cos θ) / (cos θ + μ sin
θ)] · Fh · rc ₁ , Tt ₁ = μ · Fh · rt ₁ / (cos θ + μsin θ), T ₁ = Tc ₁ + Tt ₁ = [(sin θ−μcos θ + 1) / (cos θ + μsin θ)] · μ · Fh · r = 0 .303 · Fh ·
r, Tc ₂ = μ · Fv · rc ₂ , Tt ₂ = μ · Fv · rt ₂ , T ₂ = Tc ₂ + Tt ₂ = 2μ · Fv · r = 0.636 · Fv
・ It becomes r. Note that rc ₁ ≈rt ₁ = r, rc ₂ ≈rt ₂ =
Let r.

By the way, assuming that the loss of the rotational torque of the drive gear of the outer mirror of the present embodiment and the loss of the rotational torque of the drive gear of the conventional outer mirror are the same, the insertion force P ₁ acting on the drive gear of the present embodiment is And the insertion force P ₂ acting on the conventional drive gear are compared.

From the above condition T ₁ = T ₂ , 0.303 · Fh · r = 0.636 · Fv · r, ∴Fh = 2.10 · Fv, ∴1.412 · P ₁ = 2.10 · P ₂ , ∴ P ₁ = 1.49 · P ₂

Therefore, the force Fh acting on the drive gear of the outer mirror according to the present embodiment is about 2.1 times larger than the force Fv acting on the drive gear of the conventional outer mirror, The inserting force P ₁ acting is 49 than the inserting force P ₂ acting on the drive gear of the conventional outer mirror.
%, Which means that rattling can be more effectively prevented by this amount.

The present invention is not limited to the above embodiment,
It can be implemented in various other modes. For example, the pressure contact portion 8c
The shape, the number and the like of the above are not limited to those in the above embodiment, and may be arbitrary as long as the same effect can be obtained.

Effect of the Invention According to the above configuration, since the pressure contact force of the pressure contact portion of the casing is positively applied to the inclined surface of the lower end portion of the drive gear along the direction orthogonal to the axis, the pressure contact force is applied along the axial direction of the drive gear. The loss of the rotational torque of the drive gear is reduced as compared with the case where force is applied. Therefore, if the loss of the rotational torque is made equal to the loss of the rotational torque of the drive gear of the conventional outer mirror, a correspondingly large force can be applied to the drive gear. That is, the biasing force is not applied to the drive gear along the axial direction thereof, but the press contact force is elastically applied to the inclined surface formed on the drive gear along the axis orthogonal direction, so that the press contact force is applied to the inclined surface. The component force along the inclined surface and the component force orthogonal to the inclined surface act on the drive gear, and the component force along the inclined surface and the frictional force on the inclined surface due to the component force along the above-mentioned axis orthogonal direction both drive the drive gear. It acts as a force that pushes upward, that is, in the direction of pushing the operation shaft toward the mirror holder side. As a result, a large biasing force can be applied to the drive gear by the pressure contact portion, so that the force for pressing the drive gear upward becomes large, and rattling can be more effectively prevented.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of a casing portion of an outer mirror for an automobile according to an embodiment of the present invention, FIG. 2 is a plan view of an upper casing of the outer mirror, and FIGS.
The drawings are explanatory views in which the reaction force of the urging force acting from the support portion on the inclined surface of the lower end portion of the drive gear according to the above-described embodiment is decomposed into two component forces, and the rotational torque loss of the drive gear and the like are described. And FIG. 5 is an explanatory view for explaining loss of rotational torque of a drive gear of a conventional outer mirror, and FIG. 6 is an enlarged sectional view of a main part of a casing portion of a conventional outer mirror. FIG. 8 is a partially enlarged side view and a three-dimensional perspective view when the above embodiment is applied to an actual product. 1 ... Mirror holder, 1a ... Mounting part, 2 ... Simple waterproof cap, 3 ... Gap, 4 ... Operation axis, 4a ... Leg, 4b ...
… Head, 4c… Narrow neck, 4d… Recess, 5… Lower casing, 5a… Through hole, 5b… Recess, 7… Drive gear, 7a
...... Projection wall, 7b ... Sloping surface, 7c ... Through hole, 8 ... Upper casing, 8a ... Storage section, 8b ... Guide projection section, 8c ...
… Pressing contact part, 8d …… Supporting wall, 8e …… Recessed part.

Claims (1)

[Scope of utility model registration request] 1. A mirror holder (1) supporting a mirror body is tiltably supported with respect to a casing (5, 8) so that the casing (5, 8) can be axially moved in and out of the casing. An operating shaft (4) is provided, and the distal end portion (4b) of the operating shaft (4) is fixedly attached to the mirror holder (1) without being pulled out, and the operating shaft (4) is provided in the casing (5, 8). The casing (5, 8) is provided with a tubular drive gear (7) whose upper and lower ends are rotatably supported and is fitted to the outer periphery of the casing (5, 8). The drive gear (7) is rotated by being connected to the drive device in (5, 8), and the operation shaft (4) is moved substantially axially with respect to the casing (5, 8). In an outer mirror for an automobile, which is moved back and forth to tilt the mirror holder (1) with respect to the casing (5, 8), the drive gear (7) has a lower end. A bottom conical portion (7a) having an inclined surface (7b) whose outer surface is tapered downward, and a base end of which is fixed to the casing (8) at a lower portion of the casing (8), The projecting end elastically presses the inclined surface (7b) of the lower conical portion (7a) of the drive gear (7) in a direction orthogonal to the axis of the drive gear (7) to support the drive gear (7). Also, a plurality of pressure contact parts (8c) slidable with respect to the inclined surface (7b) and arranged in an annular shape.
And a recess (5b) in which the upper end of the drive gear (7) is rotatably fitted to the inner surface of the upper part of the casing (5) to restrict the movement of the drive gear (5) toward the mirror body in the axial direction. An outer mirror for an automobile, which is characterized by being prepared as described above.