JPH07291033A - Door mirror for automobile - Google Patents

Abstract

PURPOSE:To provide a simplified structure which can be rapidly turned forward or backward when abrupt external shock is applied to a motor-driven housing type door mirror. CONSTITUTION:A fixing ring 44 fixed at the upper end of a center shaft 21 is made to have a spring function and a clutch function. Namely, a center gear 41 inserted through the center shaft is elastically pressed down and at the same time a screw groove 42 formed in the upper surface of the center gear 41 is engaged with a clutch claw 47. The driving force of a motor 50 is transmitted to the center shaft 21 side by the clutch claw 47 to rotate a door mirror at the time of a normal state, and on the other side, when a shock is applied thereto, the clutch claw 47 is removed and the door mirror is rapidly turned forward or backward to relax the shock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric retractable door mirror mounted on a front door of an automobile, and particularly, in the case of collision with an obstacle, the door mirror can be folded forward or backward of the vehicle body and has a shock absorbing function. Regarding door mirrors.

[0002]

2. Description of the Related Art Conventionally, this kind of electric retractable door mirror is
Since it protrudes to the outside of the vehicle body, it may collide with an obstacle during traveling. In the event of such a collision, the electric system is released to mitigate the impact, and only the door mirror is suddenly moved forward and backward with respect to the mirror base without applying a rotational force due to an external force to the drive motor. A structure that allows it to be overturned is used.

FIG. 5 and FIG. 6 show one conventional example, 1 is a mirror base plate fixed to a front door of a vehicle body, 2
Is a hollow center shaft fixed to the base plate 1, and 3 is a mirror holder rotatably supported by the center shaft 2 on the base plate 1. Reference numeral 4 is a ball bearing for smoothly rotating the mirror holder 3 with respect to the base plate 1. A mirror (not shown) and an actuator (not shown) for tilting the mirror are attached to the mirror holder 3. A pair of flat surfaces 5 is formed on the center shaft 2 at a portion located above the mirror holder 3. Reference numeral 6 denotes a ring-shaped clutch, which is axially movably supported on the shaft 2 via a washer 7 on the mirror holder 3, and has four convex portions 8 and 8. This clutch 6 is formed with a flat surface 9 which corresponds to the flat surface 5 of the shaft 2 and therefore the clutch 6 cannot rotate relative to the shaft 2. Reference numeral 10 denotes a center gear rotatably supported by the shaft 2, the lower surface of which is hollowed out, and the clutch 6 is housed in the hollowed-out portion 11. On the upper surface of the cut-out portion 11, there are formed recesses 12 and 12-to which the protrusions 8 and 8-of the clutch 6 mesh. 13 is
A coil spring 15 penetrating the shaft 2 and elastically pressing the center gear 10 via a washer 14,
Is a fixing ring for fixing the upper end of the coil spring 13 near the upper end of the center shaft 2. 16
Is a worm gear that meshes with the center gear 10, and is connected to the forward / reverse rotation motor 18 via a reduction gear group 17.
The motor 18, the gear group 17, and the worm gear 16 are fixed to the mirror holder 3.

In the above structure, the normal center gear 10
With the clutch 6, the respective convex portions 8 and 8-and the concave portions 12 and 12-are engaged with each other by the force of the coil spring 13.
Both are in a mechanically coupled state. Therefore, when the motor 18 rotates, the driving force is transmitted to the center gear 10, and the center gear 10 is rotated to exert a force to rotate the clutch 6. However, since the clutch 6 is supported so as not to rotate with respect to the center shaft 2, the mirror holder 3 itself rotates with respect to the shaft 2. By rotating the motor 17 forward and backward,
The mirror holder 3 is rotated to the normal position or the storage position.

When an external force is suddenly applied to the door mirror from the front or the rear due to the collision of an obstacle or the like, the center gear 1 resists the spring force of the coil spring 13.
0 and the meshing part of the clutch 6 are disengaged, and the mirror holder 3 becomes rotatable with respect to the center shaft 2 and rapidly rotates rearward or forward of the vehicle body. This is because the magnitude of the rotational force of the center gear 10 due to the impact force exceeds the meshing force between the center gear 10 and the clutch 6 due to the coil spring 13.

[0006]

According to the above configuration, the following problems occur. a. The door mirror must be the minimum size required, but in the compressed state a coil spring 13 of about 3 cm is inserted through the center shaft 2, so the center shaft 2 must be lengthened accordingly and this drive The part becomes large, and the entire door mirror becomes unnecessarily large. as a result,
The wind resistance will increase, and the design will be unfavorable. b. The center gear 10 is movable in the axial direction of the center shaft 2, and when an external impact is applied to the door mirror, the center gear 10 disengages from the clutch 6 and moves slightly upward. This movement in the axial direction may wear the center shaft 2 and cause the center gear 10 to rattle against the center shaft 2. c.
When the center gear 10 moves slightly upward on the center shaft 2 and is driven in a state where the bite with the worm gear 16 is slightly deviated, wear of the teeth of both becomes large, causing a problem in durability.

The present invention has been made in order to solve such a problem, and provides a door mirror for an automobile in which a fixed ring is provided with the functions of the coil spring and the clutch described above, and the functions thereof are omitted.

[0008]

According to the present invention, there is provided a mirror base plate which projects outward from a vehicle body of a front door and is fixed substantially horizontally, a center shaft fixed substantially vertically to the mirror base plate, and the mirror base plate, A mirror holder rotatably supported by the center shaft, a center gear composed of a worm wheel supported by the center shaft in a rotatable state with respect to the center shaft, and an upper part of the center shaft above the center gear. A fixing ring that is fixed to the upper surface of the center gear, prevents the center gear from coming off, and constantly elastically presses the center gear downward, and position regulating means that regulates the position of the mirror holder with respect to the base plate. In the equipped car door mirror, The center gear has a thread groove formed on its upper surface, and the fixing ring has
A clutch claw that elastically engages with the thread groove of the center gear is formed.

[0009]

The rotating force of the motor is applied to the center gear via the worm gear and tries to rotate it. However, since the clutch claw of the fixing ring fixed to the center shaft is engaged with the thread groove on the upper surface of the center gear, the center gear cannot rotate, and on the contrary, the mirror holder side where the motor is attached is centered on the center shaft. Rotate.
The forward / reverse rotation of the motor causes the door mirror to rotate, that is, to rotate from the storage position to the use position and vice versa.

When an obstacle collides with the door mirror,
When an external force is suddenly applied from the front or the rear, the clutch claw of the fixed ring is pushed up against the elasticity by the rotation of the center gear, and the engagement between the clutch claw and the center gear is released. As a result, the center gear becomes rotatable about the center shaft, and the door mirror rapidly rotates forward or backward of the vehicle body.

[0011]

1 to 3, 19 is a mirror base plate made of plastic, ceramic or metal which is fixed to a front door of an automobile outwardly of a vehicle body and is fixed substantially horizontally, and 20 is a substantially central portion of the plate 19. A vertically formed hollow plastic or metal center shaft is fixed to the plate 19 either integrally with the plate 19 or by a screw or the like. 21 is the base plate 19
The groove bottom surface is inclined by the pair of first grooves formed concentrically at a position close to the base of the center shaft 20. Reference numeral 22 denotes a second groove formed outside the first groove 21 in an annular shape centered on the center shaft 20 in the same manner, and reference numeral 23 denotes a rectangular groove formed concentrically with the first groove 21. It is a protrusion.

Reference numeral 24 is a spring stopper made of a metal plate which is inserted into the center shaft 20, and comprises a central ring-shaped portion 25 and a pair of tongue-shaped stopper portions 26, 26 formed in the outer peripheral tangential direction. The tips of the stopper portions 26, 26 are bent in a V shape.
The spring stopper 24 is positioned and fixed to the base plate 19 by fitting a small hole 27 formed in a part thereof into a minute projection 28 provided on the base plate 20. That is, the tips of the stopper portions 26, 26 that are bent in a V shape are designed to be located exactly in the first grooves 21, 21.

Reference numeral 29 is a ring-shaped retainer having substantially the same size as the second groove 22, and circular holes 30, 30, 30 are formed at three locations separated by 120 °, and ball bear rigs 31, 31, 30 are formed therein. 31 are arranged. The retainer 29 is mounted on the center shaft 20 so that the ball bearings 31, 31, 31 are positioned in the second groove 22 and roll. Vertical spacers 32 are formed on the outer peripheral portion of the retainer 29 to facilitate rolling of the ball bearings 31, 31, 31. The ball bearings 31, 31, 31 allow the mirror holder to smoothly rotate with respect to the base plate 19.

Reference numeral 32 denotes a plastic mirror holder supported by the center shaft 20 with a retainer 29 and a spring stopper 24 sandwiched between the base plate 19 and a circular opening 33 located near the base of the center shaft 20. It is rotatable around the center shaft 20. A mirror and a mirror tilting device (not shown) are attached to the mirror holder 32. Reference numeral 34 denotes an opening 33 on the lower surface of the mirror holder 32, that is, the surface on the base plate 19 side.
A pair of third grooves formed in a circular arc shape centering on the center of the circle correspond to the protrusions 23 on the base plate 19. The third groove 34 has a depth of two steps, that is, a deep portion 35 and a shallow portion 36. The protrusion 23 enters the deep portion 35, and both ends of the deep portion 35 regulate the retracted position and the forward tilted position of the door mirror. 37 is a mirror holder 3
The fourth groove is formed on the upper surface of 2 and has an annular shape around the opening 33. The first groove 21, the third groove 34, the protrusion 23, and the spring stopper 24 constitute a position regulating unit that determines the position of the mirror holder 32 with respect to the mirror base plate 19.

Reference numeral 38 denotes a ring-shaped retainer which is inserted through the center shaft 20 and has three small holes 39, 3.
9, 39 are provided, and the small holes 39, 39, 39
Ball bearings 40, 40, 40 are arranged in the ball bearings 40, 40, 40, and the ball bearings 40, 40, 40 roll in the fourth groove 37.

Reference numeral 41 denotes a center gear, which is a worm wheel rotatably supported by the center shaft 20, and has screw grooves 42 and 43 formed on its upper surface and outer circumference. Since the center gear 41 contacts the mirror holder 32 via the ball bearing 40, it smoothly rotates with respect to the mirror holder 32.

Reference numeral 44 denotes a fixing ring fixed to the upper end of the center gear 41, which abuts on the upper surface of the center gear 41,
The center gear 41 is prevented from coming off the center shaft 20, and is constantly elastically pressed downward. The fixing ring 44 includes a fixing portion 45 that acts on the center shaft 20 by a force that tries to fix it, a spring elastic portion 46 that applies a downward elastic pressing force to the center gear 41, and an upper surface screw groove of the center gear 41. It is composed of clutch pawls 47, 47 that elastically engage with 42. The clutch pawls 47, 47 are formed by being bent into a V shape, and a cut groove 48 is provided between the clutch pawls 47, 47 and the fixing portion 45, so that downward elastic force is imparted.

Reference numeral 49 is a worm gear that meshes with the thread groove 43 on the side surface of the center gear 41, 50 is a reversible motor that applies rotational force to the worm gear 49, and 51 is a reduction gear. Each of these parts is fixed to the mirror holder 32 side.

Next, the operation of the above structure will be described. In a normal use state, the driving force is reduced by the rotation of the motor 50 via the reduction gear 51 and transmitted to the center gear 41 via the worm gear 49. Since the center gear 41 is engaged with the clutch pawls 47, 47, at the same time, the fixing ring 4 is engaged via the clutch pawls 47, 47.
Rotational force is also applied to 4. Since the fixing ring 44 is non-rotatably supported with respect to the center shaft 20, it tries to rotate the center shaft 20. However, the center shaft 20 is
Since it is fixed to the vehicle body via 9, the motor 50 side, that is, the entire mirror holder 32 rotates about the center shaft 20. Thus, the forward / reverse rotation of the motor 50 rotates the door mirror from the use position to the storage position and from the storage position to the use position.

The position control means regulates the use position, the storage position, and the forward tiltable position of the door mirror. Figure 4
As shown in, in the normal position (A), the protrusion 23
Is located substantially in the middle of the deep portion 35 of the third groove 34, and the spring stopper 24 is stopped by catching the end of the shallow portion 36 of the third groove 34. Storage position (B)
Is determined by the protrusion 23 hitting one end of the deep portion 35 of the third groove and stopping. The forward tilted position (C) is determined by the projection 23 hitting the other end of the deep portion 35 of the third groove 34 and stopping. The motor 50 is stopped at each stop position by detecting an excessive current flowing through the motor 50.

Next, when the door mirror collides with an obstacle and a strong force that pushes the door mirror backward or forward suddenly acts, a large turning force is applied to the center gear 41, and this turning force is applied to the clutch claw. The engaging force of 47 is exceeded, and therefore the clutch pawl 47 of the fixed ring 44 is disengaged from the upper surface thread groove 42 of the center gear 41. As a result, the mirror holder 32 becomes rotatable with respect to the center shaft 20, and the door mirror suddenly tilts backward or forward. The door mirror that is tilted backward or forward is shown in Fig. 4 (B).
As shown in (C), it is stopped by being restricted by the deep portion 35 of the third groove 34.

Since the clutch claw 47 is engaged with the upper surface thread groove 42 of the center gear 41 when the vehicle is tilted backward or forward, if the motor 50 is driven in this state,
The rotational force is transmitted to the center gear 41, and the door mirror can be rotated from the rearward tilt position to the normal position, from the front tilt position to the use position, and further to the rear tilt position.

[0023]

According to the present invention, since the fixing ring functions as the conventional coil spring and clutch, these parts are unnecessary, and the structure can be simplified and downsized.

Further, according to the present invention, since the center gear does not move in the axial direction of the center shaft, wear of the center shaft is suppressed as compared with the conventional device,
There is no rattling between the center gear and the center shaft.

Further, according to the present invention, by suppressing the movement of the center gear in the axial direction to the center gear, the engagement between the center gear and the worm gear does not deviate, and the wear between them is minimized. Therefore, the durability of the center gear and the worm gear can be improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a cross-sectional perspective view of the same example.

FIG. 3 is a perspective view showing a lower surface of a mirror holder.

FIG. 4 is a cross-sectional view showing a position control means of a door mirror.

FIG. 5 is an exploded perspective view showing a conventional example.

FIG. 6 is a partial cross-sectional perspective view showing a conventional example.

[Explanation of symbols]

 19 mirror base plate 20 center shaft 21 first groove 22 second groove 23 protrusion 24 spring stopper 29 retainer 32 mirror holder 34 third groove 37 fourth groove 38 retainer 41 center gear 44 fixing ring 45 fixing portion 46 spring elasticity Part 47 Clutch claw 49 Worm gear 50 Motor

Claims (1)

[Claims] 1. A mirror base plate which projects outward from a vehicle body of a front door and is fixed substantially horizontally, a center shaft fixed substantially vertically to the mirror base plate, and a rotatably supported by the center shaft on the mirror base plate. A mirror holder, a center gear that is supported on the center shaft in a rotatable state with respect to the center shaft, and a center gear that is fixed above the center shaft above the center gear and above the center gear. A door mirror for an automobile, comprising: a fixing ring that abuts against the center gear to prevent the center gear from coming off and to elastically press the center gear constantly downward; and a position regulating means that regulates the position of the mirror holder with respect to the base plate. That gear Thread groove on the surface is being engraved, and above the fixed ring, automobile door mirror, wherein the clutch pawls engaging with the elastic in the thread groove of the center gear is formed