JPS5873802A - Detector for rotation position - Google Patents

Abstract

PURPOSE:To simplify and miniaturize constitution of a rotation position detector, by a method wherein an AC voltage of a constant frequency is applied to a plurality of exciting coils of a stator to detect the current of the exciting coil changing corresponding to a rotation position of an iron core rotor. CONSTITUTION:An AC voltage having a constant frequency is applied to a plurality of exciting coils 2-1, 2-2 for a stator. If an iron core rotor 1, positioned eccentrically against the stator, turns, a current, detected directly by the exciting coils 2-1, 2-2 for the stator, produces a signal having the same frequency as that of a feed AC whose modulation changes corresponding to a rotor position. A difference processing is made through detection of the detected currents, and this causes a rotation position to be detected directly through the exciting coils for the stator without the use of a detecting coil. As a result, a constitution of a rotation position detector is simplified and miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to rotational position detection, for example to a rotational position detector for detecting the rotational position of a rotor of a synchronous motor.

For example, the torque control of a synchronous motor is performed by keeping the internal phase difference angle constant and using only the absolute value of the stator winding current9. It is necessary to detect the rotational position (angle) of the rotor.

A conventional rotational position detector is a variable reluctance type rotary transducer, which is equipped with a stator having a plurality of excitation coils and an IF number of detection coils, and an iron core rotor. , this pigeonhole, excitation coil and detection coil and σ vs. 9r
The first one is Suginari. 9, each excitation coil 1ctH
A constant high-frequency voltage is always applied, and therefore, the magnetic resistance of the magnetic circuit formed by each dynamic coil and the iron-core rotor increases due to the rotation of the iron-core rotor, and the excitation coil's vlL The current also changes and at the same time VC1 this change in current is induced in the sensing coil. If the shape of the iron core rotor q) and the winding of the coil are properly done, a sinusoidal output can be obtained from the voltage force generated by the conventional coil v(#a), and the difference in this sine wave output is the rotational position of the iron core rotor. It becomes VC to indicate.

However, unlike the above-mentioned conventional method, the detection coil must also be used together with the excitation coil, and sixthly, the winding work is changed to AM, which reduces the manufacturing cost. There is also the problem that the container itself becomes larger.

The purpose of the present invention is to directly detect changes in the excitation current):! I think VC Motozuhiro, the detection coil is missing!
Therefore, the broom is 1! l! The purpose is to reduce the manufacturing cost (1) and to reduce the wrinkles in the detector itself, thereby solving the problems of the conventional type mentioned above.

The present invention will be explained below with reference to drawing rc.

Figure @1 is a 1#h diagram of 2*Maki-Zo's rotational position detector as an embodiment of the 10th series of the present invention. In FIG. 1, the rotor 1 has an iron core and the stator rcTI is eccentric. 2-1.2-2q excitation coil, S-1,3-2ij
'I'm resisting. A voltage of high frequency oscillation -4 is always applied to each excitation coil 2-1, 2-2. Here, if the air gap length L (θ) between the iron core rotor 1 and the stator is appropriately determined, each excitation coil 2-1, 2-2 and the iron core rotor 1
The magnetic resistance of the magnetic circuit, which is defeated by the rotation of the iron core rotor 1, changes as the iron core rotor 1 rotates. As a result, sinusoidal □ voltages Vl and Vz with a rotation angle of 1 mm changed by the excitation frequency (*=2*/)' of the high-frequency oscillator 4 are shown in Fig. 2 LA) and Fig. 2 CB). You can get as much as K$.

Each of these voltages ■1. (2) If one wave is rectified by 2t and the difference t is taken, a voltage (5) proportional to a sine wave voltage, ie, sin #, is obtained as shown in FIG. 2(C) rc. The rotational position of the iron core theta 1 at this voltage is shown. In addition, the above-mentioned voltage v,
v2 is electrically located at a 180° listening position.

FIG. 3 is a circuit diagram of a rotation position 11f jet 4 having a six-pole structure as a second embodiment of the present invention. In Figure 5, the iron core rotor 1' has a shape A and 1 as the iron core rotor 1 in Figure 1.
Also, excitation coil 1 2-5.2-4 and resistor 3-5.5
-4 is added.

12) In case yζu, voltage Vl, VZ itvtg
Vc1a d” and at the same time one voltage v
s, V4 is also electrically located at 180@l@99 position. Also in Fig. 3, when the iron core rotor 1' rotates,
By each exciting coil and the iron core rotor 1',
The magnetic resistance of the magnetic circuit changes. As a result, the rotation angle θf adjusted by the excitation frequency nail of the frequency oscillator 4
Sinusoidal waveform related to C vle v2t v5* v
4. Each voltage r obtained from the pin fL is adjusted//it is detected.
Taking Oiwake t, two sinusoidal voltages, that is, 91n3θ(V
t-Vz), cos sft (V5-V4
A voltage proportional to "equivalent to" is obtained. These voltages...
The electric corner of the iron core rotor 1' of U6 bond construction will be shown.

In the above-described embodiments, a two-pole structure and a six-pole structure are shown as multipolar structures, but it goes without saying that the present invention can be applied to other multipolar structures.

As explained above, by implementing the present invention, since no detection coil is used compared to the conventional method, the winding work of the coil can be simplified by 7 times, and therefore, the manufacturing cost can be reduced. Moreover, the detection itself can be made into a shed.

[Brief explanation of drawings]

The fat diagram is a circuit of a two-structure rotational position detector as the first embodiment of the present invention, and FIGS. 2(M) to 2(C) are diagrams for explaining the circuit operation of the pile 1. The explanatory diagram, Figure @3, is a circuit diagram of a six-pole structure rotary position detector as a second embodiment of the present invention. 111': Rotor 2-1.2-2.2-3.2-4: Excitation coil s -
1, 5-2, s-3, 3-4,: Resistor 4: High frequency oscillator pigeon 3 figure

Claims (1)

[Claims] 1. A stator having an excitation coil to which an alternating current voltage of a constant frequency is supplied; a stator provided at the center of the armpit stator and equipped with a steel core rotor; A rotational position detector that generates rotational information corresponding to the rotation of the iron core rotor by detecting the rotational speed of the iron core rotor.