JPH04313015A - Inclination sensor - Google Patents

Abstract

PURPOSE:To improve the mobility of a pendulum by reducing the coefficient of friction of the bearing section of the pendulum. CONSTITUTION:Washers 5, 6, 15, and 16 made of a material having a small coefficient of friction are used to the bearing section 11 of a pendulum 10 and at the positions 2 and 3 of a case 1 with which the bearing section 10 comes into contact. By reducing the contact areas of the washers, the mobility of the pendulum 10 is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inclination sensor mounted on a vehicle or the like.

0002

2. Description of the Related Art Conventionally, a vehicle or the like may be equipped with an inclination sensor for detecting the inclination of the vehicle. As an inclination sensor, there is one in which a fan-shaped pendulum is rotatably provided in a case, and a radial slit is provided at a fixed radius position from the center of rotation to optically detect the rotation angle of the pendulum.

0003

[Problems to be Solved by the Invention] However, in conventional tilt sensors, the bearing part of the case and the bearing part of the pendulum are installed so that they are in direct contact with each other, or a flat washer is inserted between them. was. The tilt sensor is not necessarily installed horizontally on the vehicle, and there is a small gap between the case bearing, pendulum bearing, and washer end face, but if it is installed tilted in the axial direction, there will be a slight gap between these bearings. and the end surfaces of the washer will come into contact with each other. Therefore, there was a drawback that the pendulum was difficult to rotate and a minute angle of inclination could not be detected.

The present invention was made in view of the problems of the conventional tilt sensor, and it is a technical object to enable detection of minute rotation angles by reducing the friction coefficient of the bearing portion. Take it as a challenge.

[0005]

[Means for Solving the Problems] The present invention includes a case having coaxial bearings at opposing positions on side walls, and a case that is rotatably held along a rotational axis within the case and radially arranged around the rotational axis. A tilt sensor that detects the inclination based on a pulse signal from the light receiver, which has a pendulum having a slit, and a light emitter and receiver that are arranged opposite to each other on both sides of the slit of the pendulum and fixed to the case. There are first and second washers provided on each bearing portion of the case, third and fourth washers provided on each end of the bearing portion of the pendulum, and a first and third washer provided on each end of the bearing portion of the pendulum. The second and fourth washers are brought into contact with each other, and at least one of the washers in each set is a washer having a convex surface relative to the other.

[0006]

[Operation] According to the present invention having such features, the third and fourth washers are attached to both sides of the bearing portion of the pendulum, and the washers and the first and fourth washers provided on the bearing portion of the case are connected to each other. The second washer is in direct contact with the second washer. Therefore, the coefficient of friction of these washers is reduced, and by making at least one of each set of washers have a convex surface relative to the other, the coefficient of friction is significantly reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view taken along the line A--A showing the structure of a tilt sensor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line B--B. Case 1 of the tilt sensor as shown in these figures
Inside, there is a pair of bearings 2 coaxially on opposite sides of the side surface.
and 3 are provided. The bearings 2 and 3 each rotatably hold the shaft 4, and each has a cylindrical recess. Each bearing 2, 3 is also provided with a washer 5, 6 at its end. The washers 5 and 6 are first and second washers made of a material with a small coefficient of friction, such as Teflon, and have a convex shape in which their inward surfaces are mutually convex, as shown in FIG. 3(a). washer. Now, a pendulum 10 is attached to these bearings 2 and 3. As shown in the figure, the pendulum 10 is a substantially fan-shaped member having a bearing part 11 at its center, and has a large number of fine radial slits 12 formed at regular intervals on the circumference around the bearing part 11. Moreover, weights 13 are provided symmetrically inside the same. Further, a pair of convex portions 14a and 14b are provided symmetrically near the rotation axis,
Rotation of the pendulum 10 is regulated. The bearing part 11 of this pendulum 10 is fitted into a shaft 4 which has a through hole perpendicular to the surface of the pendulum 10 and passes through the bearing parts 2 and 3, and is held rotatably. In this embodiment, washers 15 and 16 are provided on both sides of the bearing portion 11, respectively. Washer 15,1
Reference numeral 6 denotes third and fourth washers made of a material such as Teflon having a small coefficient of friction like the washers 5 and 6, and having convex surfaces facing the washer 5 side and the washer 6 side as shown in the figure. shall be. Further, a light projecting section 17 and a light receiving section 18 are attached to the lower part of the case at positions facing both sides of the slit 12, respectively. The light projecting section 17 always emits a light beam to the light receiving section 18 side through the slit 12. The light receiving section 18 receives the light and detects a pulse caused by the movement of the slit of the pendulum plate.

In the tilt sensor having such a configuration, the Teflon washers 5 and 15 and 6 and 16 are in direct contact with each other, respectively. Since this contact is a point contact, the coefficient of friction is reduced, and the mobility of the pendulum 10 is greatly improved. Therefore, even if the tilt sensor is tilted by a small angle in the direction of arrow C or D, the tilt angle can be accurately detected. Also, if the tilt sensor itself is installed with its axis tilted from the horizontal state to the E or F direction, the coefficient of friction is small, so the pendulum will
When the pendulum tilts in the D direction, the pendulum also tilts accordingly, so a minute tilt angle can be detected. In this embodiment, the sets of washers 5 and 15 and sets of washers 6 and 16 are mutually convex washers, but at least one of the washers may be a convex washer. In addition, the shape of the washer is not limited to only spherical shape.
As shown in b), it is also possible to use a curved washer instead of a flat washer.

[0009]

As described above in detail, according to the present invention, the bearing portion of the case and the bearing portion of the pendulum are brought into contact with each other via a washer that does not come into contact with each other in a planar manner. Therefore, the coefficient of friction becomes small and a minute angle of inclination can be detected. Furthermore, when this inclination angle sensor is mounted on a vehicle, there are fewer restrictions on the mounting location, and empty space in the vehicle can be used effectively. Furthermore, the shapes of the case and the pendulum themselves may be the same as in the past, and the effects of the present invention can be achieved very easily since the washer is simply inserted.

[Brief explanation of drawings]

FIG. 1 is a sectional view taken along line A-A of a tilt sensor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of the tilt sensor according to the present embodiment.

FIG. 3(a) is a perspective view of the washer according to this embodiment;
b) is a perspective view of a washer according to another embodiment;

[Explanation of symbols]

1 case 2, 3, 11 Bearing part 4 axis 5, 6, 15, 16 Washer 10 Pendulum 12 Slit 17 Light projection part 18 Light receiving part

Claims (1)

[Claims] 1. A case having coaxial bearings at opposing positions on side walls, and a pendulum held rotatably along a rotational axis within the case and having a radial slit centered on the rotational axis. , a light emitter/receiver arranged opposite to each other on both sides of the slit of the pendulum and fixed to the case, and detects a tilt based on a pulse signal from the light receiver; first and second washers provided on each bearing portion, third and fourth washers provided on respective ends of the bearing portion of the pendulum; Bring the fourth washers into contact with each other,
A tilt sensor characterized in that at least one of each set of washers has a convex surface relative to the other.