JPS6052680B2 - Pulse motor with position detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse motor equipped with a position detection circuit that electrically detects the position of a moving element.

In recent years, even in pulse motors, there have been cases in which a position detector is required to detect the position of the moving element relative to the stator in order to control the moving amount, moving speed, etc. of the moving element.

Conventionally, in the case of a rotary pulse motor, a rotating disk or the like is attached to the rotating shaft of the rotor, and a detector detects changes in the amount of light, magnetic flux, etc. as the disk rotates. The structure was common. However, in this conventional method, a rotary disk and a detector must be newly attached to the pulse motor, resulting in a complicated and large structure and poor manufacturing workability.

Further, the above-mentioned drawback naturally arises even when the above-mentioned technique is applied to a linear pulse motor because a new position detection member is required.

In view of the above-mentioned conventional nine colors, an object of the present invention is to provide a position detection circuit which has a simple structure and is easy to manufacture by electrically detecting the position of a mover without separately providing a member such as a rotating disk. To provide pulse motors.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a single-phase excitation rotary pulse motor will be described below with reference to the drawings.

In Figure 1, 1 is an oscillator that oscillates at a predetermined frequency, 2 is an AND gate in which the output terminal of oscillator 1 is connected to one input terminal, and the other input terminal is a flip-flop. It is connected to the output terminal of 3. 4 receives the clock signal CP shown in FIG.
This is a distributor that supplies excitation signals φAl, φB1, and φCl shown in FIG. 2 to the bases of the transistors 6, 7, and 8 for the phase and c phases, respectively.

The collectors of the transistors 6, 7 and 8 for each phase are commonly connected to each other and then connected to a positive power supply (+)V, and each emitter is connected to a resistor 9, 10, 11 and an exciting coil 12, respectively.
, 13 and 14 in series. 15 is a logic circuit whose input terminal is connected to the output terminal of the distributor 4, and whose output terminal is connected to field effect transistors (hereinafter simply referred to as FETs) 17, 18, 19 which are components of the switch circuit 16. , 20, 21, and 22 to output switch signals φA2, φB2, and φC2 in FIG.

That is, the drains of the FETs 17 and 18 are connected to the common connection point between the resistor 9 and the excitation coil 12, and the gates of the FETs 17 and 18 are respectively connected to the output terminal of the switch signal φA2 of the logic circuit 15.
The drains of FETs 19 and 2O are connected to the common connection point between the resistor 10 and the exciting coil 13, and the gates of FETs 19 and 2O are respectively connected to the output terminal of the switch signal φB2 of the logic circuit 15.
Each drain is connected to a common connection point between the resistor 11 and the excitation coil 14, and each gate is connected to the output terminal of the switch signal PC2 of the logic circuit 15, respectively. The FETs 17 and 19
, 2l are commonly connected, and then connected to a high frequency oscillator 24 via a resistor 23, and FETs 18, 2O, 2
After the respective sources of 2 are commonly connected, a waveform shaping circuit 25,
It is connected to the reset terminal RT of the flip-flop 3 via a counter 26 and a comparator 27.

28 is a digitizer whose input terminal is connected to the position setting signal input terminal 29 and whose output terminal is connected to the comparator 27, respectively.

30 is a start signal input terminal, which is connected to the set terminal ST of the flip-flop 3.

3 and 4 show the pulse motor of this embodiment, 31 is a stator having six salient poles, 32 is a rotor having four salient poles, and the stator. The excitation coils 12, 13, and 14 are wound around each of the salient poles 31.

The operation of the above configuration will be explained next.

The oscillator 1 and the high-frequency oscillator 24 are constantly oscillating, and in this state, after setting an appropriate number according to the desired rotation amount of the pulse motor from the position setting signal input terminal 29 to the digitizer 28, a start signal is input. A start signal is supplied from the terminal 30 to the flip-flop 3, and the flip-flop 3
Set. Then, the AND gate 2 receives both output signals from the oscillator 1 and the fritz-flop 3, and outputs the clock signal CP shown in FIG. Signals φAl, φBl, φC
1 is supplied to the bases of transistors 6, 7, and 8, and the excitation coils 12, 13, and 14 are sequentially excited, and the rotor 32 of the pulse motor rotates. On the other hand, the logic circuit 15 receives the signal from the distributor 4, and supplies the switch signal φA2 shown in FIG.
, 2O, the switch signal φB2 is applied to the gate of FET2l
, 22 are supplied with a switch signal φC2, respectively.

Note that this switch signal φA2 is the same as the excitation signal φC1.
B2 is a signal having the same phase as φA1, and φC2 having the same phase as φB1. Therefore, FETs 17 and 18 are connected to the excitation coil 1.
4 is excited, FETs 19 and 2O are activated when excitation coil 12 is excited, and FETs 2l and 2O are activated when excitation coil 12 is excited.
2 become conductive when the excitation coil 13 is excited. By the way, as the rotor 32 rotates,
Due to the change in magnetic resistance between the stator 31 and the rotor 32, the inductances of the excitation coils 12, 13, and 14 for each phase change as shown in FIG. 1.

Therefore, as shown in FIG. 5, the input terminal of the waveform shaping circuit 25 is connected to a resistor 23 and excitation coils 12, 13, 14 for each phase.
A high frequency signal with a partial pressure value determined by the inductance is output. This waveform is converted into the waveform shown in FIG. 5 by the waveform shaping circuit 25 and outputted to the counter 26 for counting. The pulse motor continues to rotate until the counted value in the counter 26 and the value in the register 28 match, and when they match, the comparator 27 outputs a reset signal to the reset terminal RT of the flip-flop 3. Since the flip-flop 3 stops outputting to the AND gate, the clock pulse CP is not supplied to the distributor 4, and the pulse motor stops.
As detailed above, the pulse motor of this embodiment can detect the position of the rotor by simply adding electric circuits such as a logic circuit 15, a switch circuit 16, a resistor 23, and a high-frequency oscillator 24 to a conventional pulse motor. Therefore, its structure is simple and manufacturing is easy.

As is clear from the above description, in the logic circuit 15 in this embodiment, the excitation signal φA1 outputted from the distributor 4 is applied to the gates of FETs 19 and 2O, and the excitation signal φB1 is applied to the gates of FETs 19 and 2O.
Excitation signal φC1 is applied to the gates of FETs 2l and 22,
An extremely simple circuit can be used as long as the wires are connected so that each output is output to the gate of l8, but for example, in the case of a multi-phase excitation pulse motor, it is also possible to connect the pulse motor in the forward direction (in the case of a linear pulse motor, forward rotation). When considering reversal (reverse for linear pulse motors), sequentially,
It can be easily estimated that selecting an excitation coil that is not energized requires a circuit as complex as the distributor.

Further, in this embodiment, a rotary pulse motor has been described, but it goes without saying that the present invention can also be applied to a linear pulse motor.

Furthermore, in this embodiment, the resistor 23 is connected to the output side of the high frequency oscillator 24, but this may be replaced with a capacitor or a coil. For example, when the resistor 23 is replaced with a capacitor, the capacitor and each exciting coil 12, 13 and 14 can be used to obtain a detection signal of a large voltage level, and when it is replaced with an inductance, the temperature coefficient can be made equal because it is the same element as the excitation coils 12, 13, and 14. can. As described above, the present invention electrically controls the moving element of the pulse motor by sequentially supplying a high frequency signal to the unexcited excitation coil of the pulse motor and detecting a change in the high frequency signal due to a change in the inductance of the coil. Since the movement position of the motor is detected, it is possible to provide a pulse motor that has a simple structure and is easy to manufacture, and its effects are significant.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram for explaining one embodiment of the present invention, Fig. 2 is a waveform diagram of each part thereof, Fig. 3 is a diagram showing the relationship between the stator and rotor of a pulse motor, and Fig. 4 5 is a diagram showing the relationship between the stator and the excitation coil, and FIG. 5 is a diagram showing changes in inductance of the excitation coil and waveforms at various parts in FIG. 1. In the figure, 5 is an excitation circuit, 12, 13, 14 are excitation coils,
16 is a switch circuit, and 24 is a high frequency oscillator.

Claims (1)

[Claims] 1. In a pulse motor in which a mover is driven by excitation coils for each phase, a circuit means that sequentially detects excitation coils to which no driving pulses are supplied and supplies a high-frequency signal to the coils; 1. A pulse motor with a position detection circuit, comprising: a position signal output circuit for deriving a high frequency voltage generated in a coil as a position signal of the moving element.