JPH059958Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an outer mirror for an automobile, and more particularly to a memory mirror that detects the position or orientation of the mirror body using electrical means.

Prior Art Conventionally, as a method of detecting the position of a mirror holder using electrical means, a method using a semiconductor element called a Hall element is known.

FIG. 4 shows the concept of a mechanism for detecting the position of a conventional automobile outer mirror of this type. In the figure, a mirror holder 48 that supports the mirror body 47 from behind is tiltably mounted on a mirror case (not shown) at a rotation fulcrum 49.

On the other hand, one end of the operating screw shaft 43 is tiltably attached to a mounting portion 48a of the mirror holder. The operation screw shaft 43 is screwed into a nut member 44 including a spring arm 45, and the nut member 44 is connected to a drive device 46 inside the mirror case. The nut member 44 is rotated by the driving of the drive device 46, the operation screw shaft 43 is moved back and forth approximately along the axial direction toward the mirror case, and the mirror holder is tilted relative to the mirror case.

A magnet 42 is built into the end of the operation screw shaft 43 on the side opposite to the mirror, and a Hall element 41 is disposed on the axial extension of the operation screw shaft 43, facing the magnet 42.

According to the above configuration, when the operation screw shaft moves back and forth, the distance between the Hall element 41 and the magnet 42 changes, and the magnetic flux density acting on the Hall element 41 of the magnet 42 also changes.

By the way, as is well known, Hall elements have a phenomenon (called the Hall effect) in which when a magnetic field is applied in a direction perpendicular to a current flowing through a conductor, an electromotive force is generated in a direction perpendicular to both the current and the magnetic field. be. This generated voltage (called Hall voltage)
The position of the operating screw shaft 43 and, therefore, the position of the mirror body can be detected by using this.

This Hall element has a characteristic that the Hall voltage is proportional to the product of magnetic flux density and control current. That is,
Utilizing this characteristic, it is possible to detect changes in the distance between the magnetic flux source, that is, the magnet and the Hall element, in response to changes in magnetic flux density.

By the way, in the conventional example, when the operating screw shaft 43 moves back and forth, the shaft 43 tilts with respect to the support point 48a on the mirror holder side, and this tilting causes the nut member 4, which is located quite far away from the Hall element 41, to tilt.
It is regulated by 4. Therefore, the vibration at the end of the operating screw shaft on the side opposite to the mirror increases. As a result, the change in the magnetic flux received from the magnet 42 in the Hall element 41 is
A magnetic flux change that is large and is a combination of the axial displacement of the screw shaft 43 and the displacement in the direction perpendicular to the axis is sensed. Moreover, since the magnet 42 and the Hall element 41 are disposed facing each other on the same axis, the magnetic flux density changes extremely as the magnet moves. As a result, large measurement errors occur.

In this way, it can be said that the conventional example is not designed to avoid this large position measurement error.

Technical Problem of the Present Invention Therefore, the technical problem to be solved by the present invention is to measure the tilt angle of the mirror holder, in other words, the amount of longitudinal displacement of the operating screw shaft using a Hall element. The object of the present invention is to provide an outer mirror for an automobile having a configuration that minimizes measurement errors.

Summary (Structure) of the Present Invention In order to achieve the above technical problem, the present invention was constructed as follows.

That is, a mirror holder supporting a mirror body is supported so as to be tiltable about a horizontal tilting center axis and a vertical tilting center axis with respect to the mirror case, and an operating screw shaft is provided within the mirror case so as to be movable back and forth in the axial direction. The distal end head is tiltably attached to the mounting portion of the mirror holder, and the operation screw shaft is screwed into the nut member connected to the drive device in the mirror case, and the nut member is driven by the drive device. an outer mirror for an automobile, wherein the operating screw shaft is moved back and forth approximately along the axial direction with respect to the mirror case, and the mirror holder is tilted with respect to the mirror case;
A magnet is built into the opposite end of the operating screw shaft along the axial direction, and a magnet is built into the mirror case so that the opposite end of the operating screw shaft slides in the axial direction. a fixed fulcrum member that supports freely and tiltably; and a fixed fulcrum member that is located at a predetermined location around the opposite end of the operating screw shaft and near the fixed fulcrum member, and in a direction perpendicular to the axis of the operating screw shaft. A Hall element whose distance is approximately constant is provided.

(Function) According to the above configuration, the mirror holder is supported at one point and can be tilted about the fulcrum by the back and forth movement of the operating screw shaft. However, the operating screw shaft is supported at two points, the attachment portion to the mirror holder and the fixed support member, and also moves back and forth with respect to the mirror holder, so it also tilts. but,
Since the operating screw shaft is restrained by the fixed fulcrum member so that the distance in the direction perpendicular to the axis between the Hall element and the operating screw shaft having the magnet is maintained almost constant, the amount of tilting displacement is small in the vicinity of the fixed fulcrum member. It is approximately zero,
In addition, even at the opposite end of the screw shaft from the head side, it is suppressed very slightly.

That is, the magnet built in the opposite end of the screw shaft to the head side is only displaced approximately along the axial direction with respect to the Hall element.

Furthermore, the end of the magnet, that is, the end opposite to the head of the operating screw shaft, does not deviate from the fixed fulcrum member.

(Effects) According to the above configuration, the Hall element is stably influenced by the magnetic field generated by the magnet. In other words, the change in magnetic flux density as the distance between the magnet and the Hall element changes is continuous, and no extreme change, ie, discontinuity, occurs.

As a result, the Hall voltage change accompanying the magnetic flux density change is reliable and reflects the displacement of the distance between the magnet and the Hall element. In other words, highly accurate position measurement is possible.

Embodiments Below, embodiments of the present invention will be described in detail based on the drawings.

The automobile outer mirror according to this example is as follows:
As shown in FIG. 1, a mirror holder 1 supporting a mirror body (not shown) is supported in a mirror case (not shown) so as to be tiltable around a horizontal tilting center axis and a vertical tilting center axis, and the mirror holder 1 The head 4b of the mirror holder push/pull operation screw shaft 4 is attached to a predetermined location on the back surface of the mirror 1, that is, the mounting portion 1a, so as to be tiltable along the axial direction, and the head 4b is screwed into the nut member 7 connected to the drive device inside the mirror case. The mirror holder 1 is tilted relative to the mirror case by moving the operating screw shafts 4, which are connected together, back and forth by the drive of a drive device, thereby adjusting the tilting 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 is tiltable about a horizontal tilting center axis and a vertical tilting center axis passing through the rotation center O thereof.

As shown in FIG. 3, the operating screw shaft 4 has a thin neck portion 4c and a spherical head portion 4b integrally formed along the axial direction at the tip of the leg portion 4a. The head 4b is rotatably fitted into the mounting portion 1a of the mirror holder 1 and supported. The leg portion 4a has a thread formed on its outer circumferential surface, and has a built-in magnet 3 in its end opposite to the head.

The mirror case that tiltably supports the mirror holder 1 is provided with a lower casing 5 and an atsupa casing 8 that engages with the lower casing 5. drive device, etc.

The lower casing 5 includes the operating screw shaft 4.
A through hole 5a having a diameter larger than the outer diameter of the leg portion 4a is formed so that the leg portion 4a of the operating shaft 4 can be freely moved in the axial direction and relatively tilted within the through hole 5a. Penetrate.

On the other hand, the Atsupa casing 8 is formed with a through hole 8a through which the leg portion 4a of the operating screw shaft 4 passes. The through hole 8a is connected to the operating screw shaft 4.
The hole 8a has a diameter that is approximately the same as the diameter of the leg portion 4a, and the inner surface of the hole 8a is formed so that the screw shaft 4 can be tilted relative to the hole 8a, as shown in FIGS. 2A and 2B. It is formed in a semicircular or wedge shape.

The drive device includes a drive motor (not shown) and a nut member 7 connected to the drive motor and fitted onto the operating screw shaft 4. That is, the nut member 7 is positioned by rotatably fitting the protruding wall 7a formed protruding along the circumferential direction on the upper casing side into the inner side of the support wall 8c of the upper casing 8, and The upper surface of the nut member 7 is fitted into the upper casing side recess 5b of the lower casing 5 so as to be relatively rotatable, and the rotation of the nut member 7 is guided between the two casings 8 and 5. In the axial through hole 7c in the center of the nut member 7, a spring arm 7d which is rotatable integrally with the nut member 7 mounted on the inner surface of the nut member 7 is inserted around the outer circumferential surface of the leg of the operating screw shaft 4. The operating screw shaft 4 is prevented from freely moving along the axial direction of the operating shaft relative to the nut member 7 by being screwed into the screw. Therefore, when the nut member 7 rotates between the casings 5 and 8,
Since the nut member 7 cannot move along the axial direction of the operating screw shaft relative to the mirror case, the operating screw shaft 4, which is screwed together with the spring arm 7d, moves back and forth approximately in its axial direction.

The through hole 7c has a diameter larger than the diameter of the operating screw shaft 4 so that the operating screw shaft 4 can be tilted, and the spring arm 7 attached to the nut member 7
d is formed so that it can be eccentric within this hole 7c.

Further, the hole 8 is located on an extension line of the radial center line of the through hole 8a provided in the Atsupa casing 8.
A Hall element 6 is installed near a.

In FIG. 1, reference numeral 2 denotes a simple waterproof seal made of rubber that prevents moisture from entering the casings 5 and 8 from the operating shaft side.

According to the above configuration, the outer mirror formed by assembling the mirror holder 1 to the mirror case operates as follows. That is, when the drive motor is driven, the nut member 7 rotates and the leg portion 4a of the operating screw shaft 4 moves back and forth approximately along its axial direction. At this time, when pushing the mirror holder 1 with the operation screw shaft 4, the head 4b of the operation screw shaft 4 pushes the mounting part 1a of the mirror holder 1, and the mirror holder 1 is moved around the horizontal tilt center axis or vertical tilt center with respect to the mirror case. Tilt around one or both axes. Furthermore, when pulling the mirror holder 1 with the operation screw shaft 4, the head 4b of the operation screw shaft 4 pulls the mounting portion 1a of the mirror holder 1 toward the casing, and the mirror holder 1 is moved toward the horizontal tilt center axis or Tilt around one or both of the vertical tilting central axes. When the mirror holder 1 is tilted, the operating screw shaft 4 is assembled so that it can freely tilt with respect to the mirror case and can move approximately along the axial direction. is the above mounting part 1a
While tilting relative to the mirror holder 1 within the mirror holder 1,
It also tilts relative to the casings 5 and 8.

However, this tilting is regulated by the through hole 8a provided in the Atsupa casing 8, and almost no displacement occurs due to the tilting of the screw shaft 4 in the axis-perpendicular direction with respect to the Hall element mounting position. Furthermore, the end of the operating screw shaft 4 on the side opposite to the head is not configured to deviate from the through hole 8a. Also,
The tilting movement of the screw shaft 4 within the through hole 7c of the nut member 7 is absorbed by the eccentric movement of the spring arm 7d.

According to the above configuration, the distance between the Hall element 6 and the operating screw shaft 4 in the direction perpendicular to the axis hardly changes during the mirror tilting operation. Further, the outer periphery of the shaft end on the opposite head side of the screw shaft 4 always faces the Hall element 6.

That is, the magnet 3 built into the end of the operating screw shaft
is placed at a position such that at least a portion thereof always faces the Hall element 6 and the distance therebetween is kept constant. Therefore, the magnetic flux density from the magnet 3 detected by the Hall element 6 is detected as a continuous change as the magnet 3 moves. That is, when the center of the magnet 3 is on the attachment center line of the Hall element 6, the Hall element 6 detects the maximum magnetic flux density, and the detected magnetic flux density decreases as it moves away from it. In this way, by detecting the magnetic flux density surrounding the Hall element 6, that is, by the Hall voltage value,
The relative position of the operating screw shaft 4 and, by extension, the tilt angle of the mirror can be identified. Moreover, since the Hall element 6 is always placed between the two poles (S, N) of the magnet 3, the magnetic flux density change does not become discontinuous, and detection errors can be minimized.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, FIG. 1 is an enlarged cross-sectional view of the main part of an outer mirror for an automobile according to this embodiment, and FIGS. 2A and 2B are through holes 8 of FIG. 1.
FIG. 3 is a perspective view showing an operating screw shaft, and FIG. 4 is an explanatory diagram showing a mechanism of a conventional automobile outer mirror. 1...Mirror holder, 1a...Mounting part, 2...
Simple prevention seal, 3... Magnet, 4... Operating screw shaft, 4a... Leg, 4b... Head, 4c... Narrow neck, 5... Lower casing, 5a... Through hole, 5
b...Recessed portion, 6...Hall element, 7...Nut member, 7a...Protruding wall, 7c...Through hole, 7d...
Spring arm, 8...Atsupa casing, 8
a...through hole, 8c...support wall.

Claims (1)

[Claims for Utility Model Registration] A mirror holder 1 supporting a mirror body is supported so as to be tiltable about a horizontal tilt center axis and a vertical tilt center axis with respect to a mirror case, and can be moved back and forth in the axial direction within the mirror case. Operation screw shaft 4 provided in
The tip head 4b of the mirror holder 1 is attached to the mounting part 1 of the mirror holder 1.
The operating screw shaft 4 is screwed into a nut member 7 that is tiltably attached to the mirror case and connected to a drive device in the mirror case, and the nut member 7 is rotated by the drive of the drive device to perform the above operation. The screw shaft 4 is moved back and forth approximately along the axial direction with respect to the mirror case, and the mirror holder 1 is tilted with respect to the mirror case. A magnet 3 is built into the end of the shaft along the axial direction, and a magnet 3 is installed in the mirror case so that the end of the operating screw shaft 4 opposite to the head can be slid in the axial direction and tilted. A distance between a fixed fulcrum member 8 supported by the operating screw shaft 4 at a predetermined location around the opposite end of the operating screw shaft 4 and near the fixed fulcrum member in the direction perpendicular to the axis. An outer mirror for an automobile, characterized in that it is equipped with a Hall element 6 having a substantially constant value.