JP2514351B2 - Tilt detection switch - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt detection switch for detecting and warning an excessive tilt.

[Outline of Invention]

The present invention, in the tilt detection switch, a space having a mortar-shaped bottom is provided in a closed container of a non-magnetic material, and a freely rolling ferromagnetic sphere is placed in the space to bring the space close to the bottom of the space from the outside of the container. By installing an iron detector,
It has a simple structure and operates in all directions.

[Conventional technology]

For safety, it is necessary to install a device for detecting an excessive inclination and issuing an alarm to a civil engineering machine such as a vehicle or a bulldozer or a crane. Conventionally, most of the inclinometers used in such devices are of a type that detects the position of a pendulum to generate an electric output, and an alarm output is generated when a certain angle is reached.

[Problems to be solved by the invention]

Although such a conventional inclinometer can easily generate an alarm output at a constant angle, it is expensive and is rarely used for alarm signals. Moreover, since the pendulum type inclinometer operates in only one direction in the horizontal plane and the inclination detection direction is determined, two or more inclinometers are required to operate in all directions. It becomes more complicated and expensive.

Therefore, the present invention seeks to inexpensively provide an omnidirectional tilt detection switch that operates in any direction in the horizontal plane.

[Means for solving problems]

The present invention comprises a non-magnetic cylindrical hermetically sealed container having a space having a mortar-shaped inclined bottom surface, and an iron or ferromagnetic material placed in the space and capable of rolling freely on the bottom surface. A tilt detection switch equipped with a sphere and an iron detector which is mounted close to the bottom surface of the space from the outside of the cylindrical hermetically sealed container and converts a positional change of the sphere into a change of an electric signal. The mortar-shaped inclined bottom surface has a first inclined portion that is substantially parallel to the horizontal axis at the center, and an acute second angle that is relatively large with respect to the horizontal axis.
And a third inclined portion having an acute angle with a relatively small angle with respect to the horizontal axis, and the sphere corresponds to the inclined angle of the object to be detected. I'm trying to locate one.

[Action]

With the above configuration, the position of the sphere on the bottom surface of the space changes greatly regardless of the direction of inclination of the container, so that inclination in all directions can be detected.

〔Example〕

FIG. 1 is a side sectional view showing a first embodiment of the present invention, and FIG.
The figure is an explanatory view showing an enlarged main part of the embodiment.

In these figures, (1) is a cylindrical container made of non-magnetic material such as brass, (1 ₁ ) is its lid, and its bottom surface (1 ₂ ) is a mortar shape with a certain inclination angle. are doing.
(2) is a spherical body made of iron or a ferromagnetic material having a high circularity used in a ball bearing, and has a diameter of 14 mm in the embodiment.
It was mm. (3) is a viscous fluid for a damper that fills the space containing the sphere (2), and in the embodiment, silicone oil having a viscosity of 500 cs was added. Then, the sealed structure by O-ring seal (1 _3), are so to reduce the adverse effects of vibration or acceleration. (4) is an iron detector,
(5) shows a cable for connecting this to a power source and taking out an output, and (6) shows a mounting plate.

The shape of the bottom surface (1 ₂ ) of the container (1) is a mortar shape that gradually decreases toward the center at a constant angle, but in this embodiment, as shown in detail in FIG. It consists of three parts. The portion A (first inclined portion) is the central axis
It is a plane perpendicular to OO '. The portion B (second inclined portion) is inclined at a relatively large angle (30 ° in the embodiment) with respect to the horizontal axis, and the portion C (third inclined portion) is slightly inclined (at the embodiment) with respect to the horizontal axis. 20 °) inclined. Therefore,
In this embodiment, if the axis OO 'is inclined by 30 ° with respect to the vertical line, the spherical body (2) comes to the position of rolling (2') along the inclined bottom surface. Then, if the inclination becomes 20 ° or less, the sphere (2)
Also returns to the lowest A part of the bottom surface (1 ₂ ).

In this embodiment, the thickness of the portion A is the smallest, about 2 mm, and when the sphere (2) is in the portion A, the distance between the sphere (2) and the detection surface of the iron detector (4) is 2 mm. Become. Then, at the position (2 ') where the sphere (2) has rolled out, this distance is about 8 mm. Therefore, if the position change of the sphere (2) is converted into the change of the electric signal by the iron detector (4), the output is inverted when the sphere (2) rolls to the position (2 ′) as described later. You can get a switch.

The flat A part is provided at the lowest position on the bottom surface (1 ₂ )
If there is no such A part, the sphere (2) will be placed on the bottom of the V shape, and the oil in the part surrounded by the lowest point and the sphere (2) will be sealed, and the sphere will be even if the inclination exceeds the limit. This is because the rolling in (2) may be suppressed and an error may occur.
This error can be avoided by making the shape of the portion A of the bottom surface (1 ₂ ) flat, and also by using a spherical surface having a radius larger than the radius of the spherical body (2).

Since the limit tilt angle of the tilt detection switch is generally required to be the same in any of the front-back and left-right directions in the horizontal plane, the shape of the bottom surface (1 ₂ ) is a sharp cone shape (mortar shape). The shape is easy to process. In a special case, the limit angle in the front-back direction is ± 30 °, but the limit angle in the left-right direction is ± 20 °, but in this case, the shape of the bottom surface (1 ₂ ) is an elliptical cone. do it.

Next, the iron detector (4) will be described with an example. The iron detector (4) consists of a detection head and a detection switching circuit. FIG. 3 is a side sectional view showing an example of a detection head, and FIG.
The figure is a top view of the detection head. In these figures, (10) is a metal or plastic non-magnetic container, (1)
1) is a saturable coil, (12) is a core of permalloy sheet, and A and B are magnet pieces having a rectangular cross-section magnetized in opposite directions. FIG. 5 is a diagram showing an example of the detection switching circuit. OSC is an oscillator, Q ₁ and Q ₂ are transistors, and (13) and (14) are output terminals. Both ends of the saturable coil (11) are connected to an oscillator OSC and are high-frequency excited. When the voltage at the point changes, transistors Q ₁ and Q ₂
Performs an on / off switching action.

In such an iron detector (4), the bias magnetic field generated by the two magnets A and B in normal times is the saturable coil (1
It is zero at the position where 1) is placed. When the ferromagnetic sphere (2) approaches the iron detector (4), a magnetic field distribution appears as if the magnets A and B were symmetrically present in the sphere (2), and the saturable coil A magnetic field that saturates it is applied to (11). This change in the magnetic field distribution can be called the magnetic mirror effect, but the voltage across the saturable coil (11) greatly changes due to a change in the magnetic field that is applied to the saturable core (12). That is, when the saturable core (12) is saturated by an external magnetic field, the change in magnetic flux density in the core due to high-frequency excitation becomes small, the inductance value of the coil decreases, and the voltage across the coil decreases. Therefore, the voltage at the point changes depending on whether the sphere (2) approaches or moves away from the output terminal (1
On / off outputs can be obtained at 3) and (14).

When using the iron detector (4) as described above, when the container (1) is not tilted, the sphere (2) is at the lowest point on the bottom surface (1 ₂ ) and the saturable coil (11) is saturated. In the state, the output of the iron detector (4) is off. Container (1)
When is tilted by a certain angle (30 ° in the example of Fig. 1), the sphere (2) rolls out and moves away from the iron detector (4) as described above, and the saturable coil (11) becomes unsaturated. Then, the output of the iron detector (4) is turned on. In addition, such on
An iron detector having a configuration different from that shown in the figure may be used as long as it can obtain an off output.

FIG. 6 is a side sectional view showing a second embodiment of the present invention. In the figure, the parts corresponding to those in FIG. 1 are designated by the same or similar reference numerals. The difference of this embodiment from the first embodiment is that an inner container (1 ') is further provided inside the container (1). The inner container (1 ′) can be replaced by opening the lid (1 ₁ ), and the alarm inclination angle can be changed by replacing the inner container (1 ′) with another inner container having a different inclination angle.
Incidentally, the inner container (1 ') of the bottom (▲ ^1' ₂ ▼) points to conical shape is similar to the first embodiment.

〔The invention's effect〕

As described above, according to the present invention, the following many advantages can be enjoyed.

1) A tilt detection switch having the same limit angle in all directions in the horizontal plane can be obtained.

2) By slightly changing the shape, it is possible to obtain a limit angle different in the front-rear direction and the left-right direction in the horizontal plane.

3) Since the space filled with oil and the iron detector are completely separated, the oil seal is easy.

4) The only thing that moves in a completely sealed container is a sphere, and since it has no supporting parts such as shafts, it is hard to break and has a long life.

5) Since the structure is simple, it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention, FIG. 2 is an explanatory view showing an enlarged main part of the same embodiment, and FIG. 3 shows an example of a detection head of an iron detector. Side sectional view, FIG. 4 is a top view of the same detection head, FIG. 5 is a circuit diagram showing an example of a detection switching circuit of an iron detector, and FIG. 6 is a side sectional view showing a second embodiment of the present invention. Is. (1) …… container, (1 ₂ ) …… its bottom, (2) …… sphere, (4) …… iron detector.

Claims (3)

(57) [Claims] 1. A non-magnetic cylindrical sealed container having a space having a mortar-shaped inclined bottom surface, and an iron or ferromagnetic material which is placed in the space and can freely roll on the bottom surface. A tilt detection switch having a spherical body and an iron detector that is mounted close to the bottom surface of the space from the outside of the cylindrical hermetic container and converts a positional change of the spherical body into a change of an electric signal. The mortar-shaped inclined bottom surface has a first inclined portion substantially parallel to the horizontal axis at the center, an acute second inclined portion that forms a relatively large angle with the horizontal axis, and a horizontal inclined axis. And a third inclined portion having an acute angle with which the opposite angle is relatively small, and the sphere is positioned at either the first or the third inclined portion in correspondence with the inclination angle of the object to be detected. Tilt detector. 2. The tilt detector according to claim 1, wherein the space is filled with a viscous fluid for damper. 3. The tilt detector according to claim 1, wherein the cylindrical hermetically-sealed container is composed of an outer container and an inner container, and the inner container is replaced to replace the first, second and An inclination detector capable of changing the angle formed by the third inclined portion.