JP3882971B2 - Tilt sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tilt sensor, and more particularly to a tilt sensor suitable for detecting the tilt of a vehicle body such as a vehicle.
[0002]
[Prior art]
Some vehicles such as two-wheeled vehicles are equipped with an inclination sensor for detecting the inclination of the vehicle. .
[0003]
One conventional tilt sensor is described in, for example, Japanese Utility Model Publication No. 63-6646. As shown in FIG. 4 (a), which is a front view, and FIG. 4 (b), which is a side view, the tilt sensor described in the publication is fan-shaped with a non-magnetic material and a conductive material. The pendulum 10 is formed, two photosensors 11a and 11b provided in the vicinity of both ends thereof, and permanent magnets 12a and 12b arranged opposite to the front and rear of the fan shape. According to this tilt sensor, when the pendulum 10 swings to the left or right due to the tilt, the tilt can be detected by the pendulum 10 blocking the light of the photosensor 11a (11a1, 11a2) or 11b. Further, when the pendulum 10 tries to swing due to inertia during acceleration or deceleration of the vehicle, an eddy current is generated in the pendulum 10 by the action of the permanent magnets 12a and 12b, and a force that prevents the swing is generated in the pendulum 10. To do. For this reason, the oscillation can be suppressed and erroneous detection can be prevented.
[0004]
[Problems to be solved by the invention]
However, the conventional tilt sensor described above has a problem that the balance of rotation of the pendulum 10 is poor and its detection characteristics become unstable. Further, since the two photosensors 11a and 11b are used, there is a problem that the manufacturing cost is increased.
[0005]
An object of the present invention is to provide a tilt sensor having a weight with good rotation balance, eliminating the problems of the prior art described above. Another object is to provide a tilt sensor that can be created with a single photosensor.
[0006]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a weight composed of a conductive non-magnetic material and rotatably supported by a support shaft, and a rotation angle detection means for detecting the rotation angle of the weight. And a magnetic force source for applying an electromagnetic braking force to the weight, wherein the weight is a bottomed cylindrical body from which a part in the circumferential direction is removed, and the bottomed cylindrical body A central axis is used as the support shaft, the magnetic source is disposed inside the bottomed cylindrical body, a bottomed cylindrical yoke is provided, the magnetic source is disposed within the bottom surface of the yoke, A first feature is that a magnetic gap is provided between the inner circumferential surface of the cylinder and the magnetic force source, and the cylindrical portion of the weight is disposed in the magnetic gap . According to this feature, an electromagnetic braking force can be applied to the cylindrical portion of the weight, and the swing of the weight during acceleration or deceleration can be effectively suppressed.
[0007]
In the present invention, the weight is a bottomed cylindrical body partly cut away in the circumferential direction, the center axis of the bottomed cylindrical body is the support shaft, and is opposed to the notch. There is a second feature in that the rotation angle detecting means is arranged and the magnetic source is arranged inside the bottomed cylindrical body. According to this feature, since the rotation balance of the weight is good, the initial response can be improved.
[0008]
In addition, the present invention has a third feature in that an angle that is half of the notch of the weight is a detection angle of the rotation angle detection means. According to this feature, the rotation angle of the weight can be detected by one rotation angle detection means, for example, one photosensor.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. 1 is a perspective view of an embodiment of the tilt sensor of the present invention, FIG. 2 (a) is a front view, FIG. 1 (b) is a cross-sectional view taken along the line AA 'in FIG. 1 (a), and FIG. It is a disassembled perspective view of the structure of a part of sensor.
[0010]
The tilt sensor has a circular substrate 1, and a stepped cylindrical projection 1 a is formed at the center of the substrate 1 as is apparent from FIG. 2 (b), and a bearing 2 is formed at the center. It is mated. The yoke 3 has a bottomed cylindrical shape having a through hole 3a at the bottom, and the through hole 3a has substantially the same diameter as the outer periphery of the cylindrical projection 1a of the substrate 1. The magnet 4 is made of, for example, a ferrite magnetic material having an annular shape, and a plurality of N-pole and S-pole magnetic poles are alternately formed at equal intervals in the circumferential direction. The annular hole 4a at the center of the magnet 4 has substantially the same diameter as the outer periphery of the cylindrical protrusion 1a, like the through hole 3a.
[0011]
The weight 5 is a bottomed cylindrical body having a cylindrical portion 5a having a diameter slightly larger than the outer diameter of the magnet 4 and slightly smaller than the inner diameter of the yoke 3, and is partially cut away by a predetermined angle θ. (Hereinafter referred to as a notch 5c). The angle θ is preferably about 120 °. At the center of the weight 5, support shafts 5b1 and 5b2 extending in both the front and rear directions are fixed. The weight 5 is made of a conductive non-magnetic material, such as aluminum (Al), and its surface is made to have a high reflectance. The cover 6 has a half bowl shape that covers the lower half of the tilt sensor. A bearing 7 for supporting the support shaft 5b2 is fixed at the center. Further, at a position facing the notch portion 5 c of the weight 5, a rotation angle detecting means of the weight 5, for example, a reflective photosensor 8 is arranged.
[0012]
The tilt sensor including the above-described components is assembled as shown in FIGS. That is, the yoke 3 and the magnet 4 are fitted to the cylindrical protrusion 1 a of the substrate 1 by the through hole 3 a and the annular hole 4 a, and the weight 5 is disposed so as to face the magnet 4. . One of the support shafts 5b of the weight 5 extending in the front-rear direction is supported by the bearing 2 and the other 5b2 is supported by the bearing 6 so as to be rotatable. At this time, the cylindrical portion 5 a of the weight 5 is positioned in the magnetic gap between the yoke 3 and the magnet 4.
[0013]
When the inclination sensor is attached, for example, when the vehicle body of a vehicle such as a two-wheeled vehicle is not inclined more than a predetermined angle θ / 2, the photosensor 8 faces the notch 5c, and the photosensor 8 reflects. Does not detect light. Therefore, the tilt sensor does not detect the tilt of the vehicle body. On the other hand, when the vehicle body falls to the ground, the tilt sensor tilts together with the vehicle body. At this time, since the weight 5 is light on the side where the notch 5c exists and is heavy on the side where the notch 5c does not exist, the weight 5 always tries to maintain the same posture. On the other hand, the inclination sensor excluding the weight 5, that is, the substrate 1, the yoke 3, the magnet 4, and the photosensor 8 are inclined together with the vehicle body. As a result, the photosensor 8 comes to face the weight 5, and the photosensor 8 detects reflected light reflected from the surface of the weight 5 to detect that the vehicle body is tilted.
[0014]
As described above, according to the present embodiment, the inclination sensor can be formed by one photosensor 8, so that it can be produced at low cost. Further, since the area of the cutout portion 5c of the weight 4 is smaller than the area of the non-cutout portion, the rotation balance around the support shaft 5b of the weight 5 is good, and the weight 5 is supported on the support shaft compared to the conventional one. It can be smoothly rotated around 5b. Further, the force applied to the support shafts 5b1, 5b2 when the weight 5 is swung is made substantially uniform compared to the conventional one, and the life of the support shafts 5b1, 5b2 can be extended.
[0015]
Further, during acceleration or deceleration, the weight 5 may swing due to inertia, and the inclination may be erroneously detected. However, in this embodiment, the cylindrical portion 5a of the weight 5 has a gap between the yoke 3 and the magnet 4. Since the cylindrical portion 5a cuts off the magnetic field formed between the yoke 3 and the magnet 4, an eddy current is generated in the cylindrical portion 5a, and the weight 5 is electromagnetically braked. In addition, since the position where the electromagnetic braking is applied is the position farthest from the support shaft 5b which is the central axis of the weight 5, the moment increases and the effect of the electromagnetic braking increases. For this reason, the erroneous detection accompanying the said acceleration or deceleration can be prevented effectively.
[0016]
The tilt sensor of the present invention is preferably applied to, for example, a vehicle equipped with an injection type engine or the like. When the tilt sensor is applied to the vehicle, for example, when the vehicle falls while the vehicle is running, this can be detected, and the pump that sends fuel to the engine can be stopped to automatically stop the engine. .
[0017]
【The invention's effect】
As is clear from the above description, according to the present invention, the weight is formed of a bottomed cylindrical body having a part of the notch in the circumferential direction, and the magnetic source is disposed therein. The electromagnetic braking force acting on the weight can be increased. For this reason, it becomes possible to effectively suppress the swing of the weight during acceleration and deceleration, and to reduce erroneous detection of inclination.
[0018]
Further, since the rotation balance of the weight can be improved, the initial response can be improved. Furthermore, since the rotation angle of the weight can be detected by one rotation angle detection means, an inexpensive tilt sensor can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a tilt sensor according to an embodiment of the present invention.
FIG. 2 is a front view of the embodiment and a cross-sectional view taken along line AA ′.
FIG. 3 is an exploded perspective view of a part of the embodiment.
FIG. 4 is a front view and a side view of an example of a conventional apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2, 7 ... Bearing, 3 ... Yoke, 4 ... Magnet, 5 ... Weight, 6 ... Cover, 8 ... Photosensor.

Claims (6)

A weight composed of a conductive non-magnetic material and rotatably supported by a support shaft, rotation angle detecting means for detecting the rotation angle of the weight, and a magnetic source for applying an electromagnetic braking force to the weight In a tilt sensor with
The weight is a bottomed cylindrical body from which a part in the circumferential direction is removed, the central axis of the bottomed cylindrical body is the support shaft, and the magnetic source is provided inside the bottomed cylindrical body. And a bottomed cylindrical yoke, the magnetic force source is disposed in the bottom surface of the yoke, and a magnetic gap is provided between the cylindrical inner peripheral surface of the yoke and the magnetic force source. An inclination sensor characterized in that a cylindrical part of the weight is arranged in the part. A weight composed of a conductive non-magnetic material and rotatably supported by a support shaft, rotation angle detecting means for detecting the rotation angle of the weight, and a magnetic source for applying an electromagnetic braking force to the weight In a tilt sensor with
The weight is a bottomed cylindrical body with a part cut in the circumferential direction, the center axis of the bottomed cylindrical body is the support shaft, and the rotation angle detecting means is opposed to the notch. And the magnetic force source is disposed inside the bottomed cylindrical body, a bottomed cylindrical yoke is provided, the magnetic force source is disposed in the bottom surface of the yoke, and the cylindrical inner peripheral surface of the yoke A tilt sensor, characterized in that a magnetic gap is provided between the magnetic force source and the magnetic gap, and the cylindrical portion of the weight is disposed in the magnetic gap. The tilt sensor according to claim 2,
The tilt sensor, wherein the rotation angle detecting means is a photo sensor. The inclination sensor according to claim 2 or 3,
An inclination sensor characterized in that the half angle of the notch of the weight is a detection angle of the rotation angle detection means. A weight composed of a conductive non-magnetic material and rotatably supported by a support shaft, rotation angle detecting means for detecting the rotation angle of the weight, and a magnetic source for applying an electromagnetic braking force to the weight In a tilt sensor with
A weight that is opposed to the rotation angle detecting means and has a part removed, and a bottomed cylindrical body integrally formed with the weight and a cylinder, and the bottomed cylindrical body includes the weight An inclination sensor, wherein magnetic force sources are arranged concentrically, and the magnetic force source is an annular magnet. The tilt sensor according to claim 1, 2, or 5,
The magnetic force source is an annular magnet, and a plurality of N-pole and S-pole magnetic poles are alternately formed at equal intervals in the circumferential direction.

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