JPH0663767B2 - Inclined state detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Purpose of the Invention (1) Field of Industrial Application The present invention detects an inclination state of an object such as a vehicle body of an agricultural tractor to detect an alarm signal and control the attitude of the agricultural tractor with respect to a working machine. A tilt state detection device used to generate a signal, in particular, a pendulum is oscillatably suspended on a support system attached to an object whose tilt state is to be detected, and the relative swing angle between the pendulum and the support system is electrostatically determined. The present invention relates to an improvement in what is detected capacitively.

(2) Conventional Technology Conventionally, such an inclination state detecting device is disclosed in, for example, Japanese Patent Publication No. 59-53.
It is already known as described in Japanese Patent No. 485.

(3) Problems to be Solved by the Invention In the conventional tilt state detection device, the swing direction of the pendulum is limited to one direction, and therefore the tilt angle direction to be detected is also limited to one direction. Therefore, when detecting the tilt angle in a certain direction, the two tilt state detection devices are
The detection directions must be different from each other by 90 °, which requires not only a large installation space but also an increase in cost.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a simple and effective tilt state detecting device that can detect a tilt state in any direction, which is a single device.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention is suspended in all directions by a support system attached to an object whose tilt state is to be detected. Pendulum, a bowl-shaped common electrode formed by forming a part of a sphere on the pendulum, and a spherical surface of the common electrode facing each other with a constant gap, and the pendulum swings in the first direction. Time,
A pair of first differential electrodes that are fixed to the support system side by side so that the facing areas of the common electrode increase and decrease opposite to each other, also face the spherical surface of the common electrode with a constant gap, and
When the pendulum swings in the second direction orthogonal to the direction, the pair of second differential electrodes are fixed to the support system side by side so that the facing areas of the common electrode increase and decrease in opposite directions, and both first difference electrodes. First detecting a capacitance difference between a moving electrode and a common electrode as a voltage
It is characterized in that the tilt state detecting device is constituted by the detecting means and the second detecting means for detecting the electrostatic capacity difference between the common electrodes of both the second differential electrodes as a voltage.

(2) Work If the pendulum swings relative to the support system as the object is tilted, the swing is divided into a component in the first direction and a component in the second direction.

The swing component in the first direction causes a difference in capacitance between the common electrodes of both the first differential electrodes, and the difference is taken out as a voltage by the first detecting means, and the first The tilt angle in one direction can be known.

Further, due to the swing component in the second direction, a difference occurs in electrostatic capacitance between the common electrodes of both the second differential electrodes, and the difference is taken out as a voltage by the second detection means, and the difference of the object The tilt angle in two directions can be known.

(3) Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1, a vehicle body of an agricultural tractor having a pair of left and right front wheels Wf, Wf 'and a pair of left and right rear wheels Wr, Wr'. B
State detection device S for detecting the inclination state in the right place
Is installed.

As shown in FIG. 2, this inclination state detecting device S has an outer case 1 attached to a vehicle body B via an elastic member 2, and a base opening for closing the outer case 1 to close the outer case 1. The base 3 is fixed via the seal member 4. A gate-shaped frame 5 is erected on the upper surface of the base 3, and a pendulum 6 is suspended in a central portion of the frame 5 via a universal joint 7 so as to be swingable in all directions.

The pendulum 6 includes a bowl-shaped weight 8 forming a part of a sphere, and the weight 8
And an arm 9 that is supported by the frame 5 via a universal joint 7 and swings the weight 8 around its bowl-shaped center. The weight 8 is made of a conductive material such as Al, Cu. It is molded from the non-magnetic material and has a common electrode for the first and second differential electrodes 14, 14 '; 15, 15' which will be described later.

A mounting plate 10 made of iron is fixed to the base 3 below the pendulum 6 with screws 11 together with the frame 5.
A bowl-shaped electrode substrate 12 having a diameter larger than that of the weight 8 and facing each other with a certain space on the spherical lower surface of the weight 8, and four or more facing the weight 8 with the electrode substrate 12 interposed therebetween. The above permanent magnets 13, 13 ... Are fixedly installed. These magnets 13, 13 ... Are arranged at equal intervals around the axis of the pendulum 6 and are adjacent to each other.
The magnetisms of 3 and 13 are arranged upside down.

The electrode substrate 12 is formed of an insulating material such as synthetic resin, and has a pair of first differential electrodes arranged in the left-right direction of the vehicle body B on the upper surface thereof, as shown in FIG. 14,1
4'and a pair of second differential electrodes 15 and 15 'which are also arranged in the front-rear direction of the vehicle body B with the center portion therebetween are formed. These electrodes 14, 14 '; 15, 15' are molded from a conductive non-magnetic material such as Cu, and are fan-shaped with a central angle of 45 ° so as to divide the upper surface of the electrode substrate 12 into four equal parts. It is formed.

As shown in FIG. 4, the common electrode for 8 pairs of weights is the oscillation circuit 16
Of the first capacitance-voltage conversion circuit 17 and the second differential electrodes 15, 15 'of the second capacitance-voltage conversion circuit 18 connected to the input terminal of the first capacitance-voltage conversion circuit 17. Connected to the input terminal of.

Where the capacitance between electrodes 8 and 14 is Cx, the capacitance between electrodes 8 and 14 'is Cx', the capacitance between electrodes 8 and 15 is Cy, and the capacitance between electrodes 8 and 15 is Be Cy ′. Then, the first capacitance-voltage conversion circuit 17 outputs a voltage proportional to the value of Cx'-Cx, and the second
The capacitance-voltage conversion circuit 18 outputs a voltage proportional to the value of Cy-Cy'.The output terminals of both circuits 17 and 18 have a left-right tilt angle indicator 19 and a front-back tilt angle. The display device 20 is connected to the left-right direction driving unit and the front-back direction driving unit of the attitude control device that controls the attitude of the working machine connected to the vehicle body B, respectively.

Next, the operation of this embodiment will be described.

When the vehicle body B of the agricultural tractor is kept horizontal, the weights 8, that is, the common electrode and the electrode substrate 12 are centered on the same vertical line. Therefore, the facing area of the right electrode 14 'with the common electrode 8 and the facing area of the left electrode 14 with the common electrode 8 are equal, the capacitance difference (Cx'-Cx) between them is zero, and the front electrode The area of the 15 electrodes facing the common electrode 8 and the area of the rear electrode 15 'facing the common electrode 8 are equal, and their capacitance difference (Cy-Cy') is also zero. The first and second capacitance-voltage conversion circuits 17 and 18 output voltages of a predetermined value (for example, 2.0 V) to the displays 19 and 20, respectively.

Now, if the vehicle body B of the agricultural tractor leans down to the right during work, for example, the base 3 of the tilt state detecting device S also leans down to the right along with the electrode substrate 12, while the pendulum 6 is in the current state. Since it is maintained, the pendulum 6 swings relative to the electrode substrate 12 to the right. Along with this, the facing area of the right electrode 14 'with the common electrode 8 increases, while the facing area of the left electrode 14' with the common electrode 8 decreases, so that the capacitance difference (Cx'-Cx) between them increases. , The first capacitance-voltage conversion circuit 17
Output voltage increases as shown by the line a in FIG. 5, whereby the right downward angle of the vehicle body B is displayed on the display unit 19.

On the contrary, when the vehicle body B inclines to the left, the capacitance difference (Cx'-Cx) decreases, and the output voltage of the first capacitance-voltage conversion circuit 17 is as shown by line b in FIG. As a result, the display unit 19 displays the leftward descending angle of the vehicle body B.

On the other hand, if the ratio of the facing area of the front electrode 15 and the common electrode 8 to the facing area of the rear electrode 15 'and the common electrode 8 does not change at this time, the output voltage of the second capacitance-voltage conversion circuit 18 changes. There is no.

Further, if the vehicle body B inclines forward and downward, for example, the pendulum 6 swings backward relative to the electrode substrate 12. Along with this, the facing area of the front electrode 15 with the common electrode 8 increases, while the facing area of the rear electrode 15 'with the common electrode 8 decreases, so that the capacitance difference (Cy-Cy') between them is reduced. The output voltage of the second capacitance-voltage conversion circuit 18 increases and the output voltage of the second capacitance-voltage conversion circuit 18 increases as shown in FIG. 5C, whereby the front-down angle of the vehicle body B is displayed on the display 20.

On the contrary, when the vehicle body B leans backward and downward, the capacitance difference (Cy-Cy ') decreases, and the output voltage of the second capacitance-voltage conversion circuit 18 decreases as shown by the line d in FIG. As a result, the rear descent angle of the vehicle body is displayed on the display 20.

When the vehicle body B is tilted in both the left and right directions and the front and rear directions, the tilt component in the left and right direction and the tilt component in the front and rear direction are simultaneously detected by the above operation.

When the pendulum 6 vibrates violently due to disturbance generated by starting, braking, and traveling of the agricultural tractor, the weight 8 rapidly moves so as to cross the magnetic flux formed between the adjacent permanent magnets 13 and 13. Eddy current is generated in the weight 8 so as to prevent its movement. That is, a magnetic braking force is applied to the pendulum 6 to dampen its sharp swing.

In this embodiment, the base 3, the frame 5, the mounting plate 10 and the electrode substrate 12 correspond to the supporting system in the present invention, the first capacitance-voltage conversion circuit 17 corresponds to the first detecting means, and the second capacitance. −
The voltage conversion circuit 18 corresponds to the second detection means.

C. Effects of the Invention As described above, according to the present invention, a pendulum suspended in a support system attached to an object whose tilt state is to be detected is swingable in all directions, and this pendulum forms a part of a sphere. And the bowl-shaped common electrode that is formed by facing the spherical surface of the common electrode with a certain gap, and when the pendulum swings in the first direction, the facing area of the common electrode increases or decreases in opposite directions. And a pair of first differential electrodes that are fixed to the support system side by side so as to face each other with a constant gap on the spherical surface of the common electrode and in a second direction orthogonal to the first direction. At the time of rocking, static electricity between a pair of second differential electrodes, which are fixed to the support system side by side so that the facing areas of the common electrodes increase and decrease in opposite directions, and the common electrodes of both first differential electrodes The capacitance difference between the first detection means for detecting the capacitance difference as a voltage and the common electrode of both the second differential electrodes is defined as the voltage. Since it is configured inclined state detection device and a second detecting means for detecting Te, it is possible to detect the inclination of all directions in a single apparatus, not be detected only in one direction inclined state 2
Compared to the case where the base tilt state detection device is installed in a different detection direction, the cost is extremely low, and since there is only one pendulum, the entire device does not become extra large,
It can be easily installed in a narrow space.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a plan view of a vehicle body of an agricultural tractor in which a tilt detecting device is installed, FIG. 2 is a vertical cross-sectional rear view of the tilt detecting device, and FIG. 2 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is an electric circuit diagram, and FIG. 5 is an output characteristic diagram of the first and second capacitance-voltage conversion circuits. S ... Inclination state detecting device, 3 ... Base as a supporting system, 6 ... Pendulum, 7 ... Universal joint, 8 ... Weight and common electrode, 14, 14 '... First differential electrode, 15,15 '…… Second differential electrode, 16 …… Oscillation circuit, 17…
... First capacitance-voltage conversion circuit as first detection means, 18 ...
... Second capacitance-voltage conversion circuit as second detection means

Claims (1)

[Claims] 1. A pendulum suspended in a support system attached to an object whose tilt state is to be detected so as to be swingable in all directions, and a bowl-shaped common electrode formed by forming a part of a sphere on the pendulum. ,
The common electrode is opposed to the spherical surface with a certain gap, and when the pendulum swings in the first direction, they are fixed side by side so that the areas facing the common electrode increase and decrease in opposite directions. The pair of first differential electrodes face the spherical surface of the common electrode with a certain gap therebetween, and when the pendulum swings in the second direction orthogonal to the first direction, the facing area of the common electrode is First detection means for detecting, as a voltage, a capacitance difference between a pair of second differential electrodes that are fixed to the support system side by side so as to increase and decrease in opposite directions, and a common electrode of both first differential electrodes. And a second detecting means for detecting a capacitance difference between the common electrodes of both the second differential electrodes as a voltage, and a tilt state detecting device.