JPH0434409Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention detects the inclination angle of agricultural machinery such as a tractor or other mechanical equipment, and uses the detected output to control the equipment, display the inclination angle, etc. The present invention relates to an inclination angle detection device used for.

[Prior Art] As an example of this type of inclination angle detection device, a device using a working transformer 1 as shown in FIG. 6 has been widely used. In this Figure 6,
A primary coil 1a and secondary coils 1b, 1b of the differential transformer 1 are fixed to the body 2 via a support member 3. Further, a pair of elongated plate springs 4, 4 are provided in a hanging manner on the body 2, and the movable core 1c of the operating transformer 1 is supported at the lower end side of each of these plate springs 4. Therefore, according to this configuration, when the body 2 is tilted, the movable core 1c is moved relative to the primary coil 1a and the secondary coil 1b. If the primary coil 1a is excited with a low frequency alternating current, an output voltage corresponding to the amount of displacement will appear in the secondary coil 1b, so the tilt angle of the aircraft body 2 can be detected according to this output voltage.

However, in the above conventional configuration, the differential transformer 1
The primary coil 1a and the secondary coil 1b
Since it is relatively expensive as it requires aligning and winding, there is a problem in that the price of the entire device increases. In addition, it is necessary to increase the dimensional accuracy between the primary coil 1a, the secondary coil 1b, and the movable core 1c inserted therein, that is, the attachment precision of the movable core 1c to the leaf spring 4, resulting in poor manufacturing efficiency. There is also the problem of becoming.

[Purpose of the invention] The present invention was devised in view of the above circumstances, and its purpose is to obtain a detection output with good linearity with an extremely simple configuration, to be able to do it at low cost, and to improve its manufacturability. It is an object of the present invention to provide an inclination angle detection device that has effects such as being able to realize an improvement in the angle of rotation.

[Summary of the invention] In order to achieve the above-mentioned object, the present invention attaches a weight made of a magnetic material to the lower end of an elastically deformable elongated member whose upper end is supported by the aircraft body and is provided in a hanging shape. A pair of detection devices are located on substantially the same horizontal plane so that their central axes are shifted by a predetermined distance, and are opposed to each other with the weights sandwiched between them with a predetermined clearance gap between them. A signal provided in the coil and the body, further detecting the amount of change in inductance of each detection coil due to a change in the distance between these detection coils and the weight, and outputting this as a signal indicating the inclination angle of the body. This configuration includes a processing circuit.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

1 and 2, a leaf spring 11 is an elastically deformable elongated member, and its upper end is supported by the ceiling wall 12a of the case 12, which is the fuselage body, and is provided in a hanging shape. It is provided so as to be swingable in the directions of arrow A and counter-arrow A in FIG. Reference numeral 13 denotes a weight made of a magnetic material that is attached and fixed to the lower end of the leaf spring 11, and is made of, for example, a rectangular iron plate. 14 and 15 are a pair of detection coils arranged diagonally, and these detection coils 1
Specifically, center axes 14a and 15a are shifted by a predetermined distance to positions on substantially the same horizontal plane on the opposing inner walls 12b and 12c of the case 12, and a predetermined distance between them and the weight 13 is provided. It is provided with sufficient clearances 16 and 17.

In FIG. 3 showing the electric circuit configuration, 18 is a sine wave oscillator, and between both output terminals of this is a series circuit of the pair of detection coils 14 and 15 and a resistor 1.
9 and 20 series circuits are connected, respectively, to form a bridge circuit. Then, the output from the output point P ₁ (the common connection point of the detection coils 14 and 15) is given to one input terminal of the differential amplifier 23 via the rectifier/smoothing circuit 21 and the resistor 22.
The output from output point P ₂ (common connection point of resistors 19 and 20) is applied to the other input terminal of differential amplifier 23 via rectifier/smoothing circuit 24 and resistor 25.
The sine wave oscillator 18, resistors 19, 20, rectifier/smoothing circuits 21, 24, resistors 22, 25, and differential amplifier 23 constitute a signal processing circuit 26 according to the present invention.

In the above configuration, the output voltages at the output points P ₁ and P ₂ are set to be balanced when the case 12 is not tilted. Therefore, when the case 12 is tilted in the direction of the arrow A or the direction opposite to the arrow A, the leaf spring 11 is displaced accordingly. One of the distances (corresponding to the dimensions of the extra gaps 16 and 17) expands while the other decreases. As a result, the inductances of the detection coils 14 and 15 change, resulting in a difference in the output voltages at the output points P ₁ and P ₂ , and the difference voltage is amplified by the differential amplifier 23 to change the inclination angle of the case 12 . A detection signal Vd having a voltage value corresponding to the voltage value is outputted as a detection signal Vd. In this case, the relationship between the distance X between the weight 13 and each detection coil 14, 15 and the inductance L of each detection coil 14, 15 becomes a nonlinear state as shown in FIG. Coils 14, 15
By connecting the coils in series and taking the inductance ratio of each coil 14 and 15, the detection output, that is, the detection signal
I try to obtain linearity of Vd. That is, according to this embodiment, as shown in FIG. 5 showing the relationship between the detection signal Vd and the inclination angle of the case 12, the detection signal Vd
shows good linearity within a predetermined tilt angle range. Moreover, in this way, the detection coils 14, 1
5 are connected in series and the detection signal Vd is obtained from the inductance ratio thereof, temperature changes in the characteristics of each detection coil 14 and 15 can be canceled out, and the temperature characteristics of the detection signal Vd can be improved. Furthermore, in this case, the magnetic flux density that runs longitudinally through each detection coil 14, 15 is strongest at its central axis, so if the detection coils 14, 15 are simply placed opposite each other, their magnetic fluxes will influence each other. The linearity of the detection signal Vd will be impaired. However, in this embodiment, since the detection coils 14 and 15 are arranged diagonally, it is possible to prevent as much as possible the mutual influence of magnetic flux between the detection coils 14 and 15, and thereby the detection signal
This makes it possible to improve the linearity of Vd. Also,
The magnetic flux generated by the detection coils 14 and 15 is determined by the ampere turns of the detection coils 14 and 15, and there is no need to wind the detection coils 14 and 15 in parallel. This makes it possible to simplify the structure and reduce costs accordingly. Of course, according to this embodiment, it is not necessary to increase the mounting precision of the weight 13 and the detection coils 14, 15 as much as the mounting precision of the movable core in a conventional differential transformer, thereby improving manufacturing efficiency. It becomes like this. Furthermore, according to this embodiment,
It is sufficient to provide a relatively small and lightweight weight 13, and the distance between the detection coils 14 and 15, as well as the swing width of the leaf spring 11, can be reduced, so that impact resistance can be improved.

[Effects of the invention] According to the present invention, as is clear from the above explanation, the inclination angle detection device for detecting the inclination angle of the aircraft and providing the detected output for controlling mechanical equipment, etc., has improved linearity. It is possible to obtain a good detection output with an extremely simple configuration and at low cost, and it also has practical effects such as improved manufacturability and impact resistance.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1 is a vertical side view, Figure 2 is a cross-sectional plan view, Figure 3 is a wiring diagram, and Figure 4 shows the inductance of the detection coil. Characteristic diagram, Figure 5 is a characteristic diagram of detection output,
FIG. 6 is a longitudinal sectional side view showing a conventional configuration. In the figure, 11 is a leaf spring (elongated member), 12 is a case (aircraft body), 13 is a weight, 14 and 15 are detection coils, 16 and 17 are clearance gaps, 18 is a sine wave oscillator, and 23 is a differential amplifier. , 26 indicate a signal processing circuit.

Claims (1)

[Scope of utility model registration request] An elastically deformable elongated member whose upper end is supported by the fuselage and is provided in a hanging shape, and a weight made of a magnetic material attached to the lower end of this elongated member, and mutual centers on approximately the same horizontal plane. a pair of detection coils provided on the body so that their axes are offset by a predetermined distance, and facing each other with the weight sandwiched therebetween with a predetermined clearance between them; and a signal processing circuit that detects the amount of change in inductance of each detection coil due to a change in the distance between these detection coils and the weight, and outputs this as a signal indicating the inclination angle of the aircraft body. An inclination angle detection device featuring: