JPS6013399B2 - Starting method of commutatorless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting method for a commutatorless motor that requires advanced servo characteristics.

For example, non-commutator motors used to drive heads and carriages in printers are now required to have two to three times the servo performance versus weight of conventional motors.

In addition, a position detector is required for positioning the dial plate, etc., and a commutatorless motor requires a rotor angular position detector for excitation current distribution, but due to dimensional limitations, both detectors are required. In some cases, it may be difficult to establish a The position detector signal for positioning is incremental like a simple pulse train and does not represent an absolute value, so it cannot be used as is for excitation current distribution.

The present invention was made to solve the above problems,
Examples shown in the drawings will be described below. In FIG. 1, 1 is an electric motor, 2 is a driven machine, 3 is a character position detector, 4 is a position comparison circuit, 5 is a speed comparator, 6 is a multiplier, and 7
8 is a waveform generation circuit, 8 is a power amplifier circuit, 9 is an excitation command circuit, and A, B, C, and D are switches, respectively.

In Fig. 2, the Q-phase armature winding of the motor is 11
is an 8-phase armature winding, and both are arranged at a position of 90 degrees in electrical angle.

12 is a rotor, which indicates the direction of the magnetic axis of the rotating field.

1 is a state in which the rotor 12 is stopped naturally, and the magnetic field of the rotating field is at an angle of 8 with the phase winding 10. Therefore, this angle 8 is detected each time, but if it cannot be fixed at a certain fixed angle, an exciting current with a fixed positional relationship with the rotor cannot be obtained from an incremental signal such as a character position detector, and a non-commutated motor This means that operation cannot be started. Therefore, when the phase winding 10 in the state shown in FIG. 2 1 is excited with DC current, the rotor 12 rotates as shown in FIG.
become that way. At this time, in addition to the case where 6=0 and stable, it is also possible that a=shore. At this time, it is in an unstable state where it rotates with a slight external force and tries to settle down to 0=0. Even at this time, if a pulsed current is further passed through the 8-phase winding 11, the rotor 12 rotates rapidly and becomes stable at 8 white and 0. Returning to Fig. 1, when the position command pulse comes, switches A, B, and C remain open, switch D is closed, and the Q-phase winding 10 of the motor 1 is excited with direct current, and the pulse is applied to the 8-phase winding. A current flows through the current. As a result, the rotor 12 rotates to the reference angular position of H=0 as described above.

Immediately thereafter, switch D is opened and switch A is opened.
, C are opened, and the signal from the character position hawk detector 3 is input to the waveform generation circuit 7. The waveform generating circuit 7 includes a counter, ROM, etc., and the counter is reset together with the switch D, and starts counting the signal from the character position detector 3. Then, according to a predetermined number of counts (determined by the number of poles of the motor and the number of pulses per revolution), a waveform indicating the direction and duration of the current to excite the windings 10 and 11 is generated from the ROM. This waveform is multiplied by the output of the speed comparator 5 by the multiplier 6, and amplified by the power amplifier circuit 8 to become a two-phase sine wave.
, 1 1 are respectively excited in a predetermined order, and the haze motor 1 is started as a commutatorless motor. Furthermore, the switch B is also closed, the signal from the character position detector 3 and the position command pulse are compared by the position comparator 4, and the character is positioned and stopped at a predetermined character position. Although we have explained the case where the motor is two-phase, it can also be applied to a three-phase motor by adding a known two-phase three-phase converter.In this case, the two phases of the windings are excited with DC. , the remaining one phase can be excited with a pulsed current to stop the rotor from rotating, and this position can also be used as the reference angular position.As described above, the present invention can be applied to at least one phase of the armature winding. The rotor is rotated to the reference angular position by exciting one phase with direct current and the remaining one phase with pulsed current, and then the armature winding is rotated by counting the predetermined pulses of the positioning pulse signal. Since the motor is started and rotated by energizing it in a predetermined order, there is no need for a rotor angular position detector, and dimensional restrictions can be met without any problems, resulting in a compact, high-performance commutatorless motor. There are features that can be used.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram. i is the electric motor, 2 is the driven machine, 3 is the character position detector.
is a position comparison circuit, 5 is a speed comparator, 6 is a multiplier, 7 is a waveform generation circuit, 8 is a power amplifier, 9 is an excitation command circuit, A,
B, C, and D are switches, 10 is a Q-phase armature winding, 11 is a B-phase armature winding, and 12 is a rotor. Figure 1 Figure 2

Claims (1)

[Claims] 1 In a non-commutator motor that performs positioning using pulse signals for positioning, the rotor is referenced by exciting at least one phase of the motor windings with direct current and the remaining one phase with pulsed current. A method of starting a commutatorless motor in which the motor is rotated to an angular position and the windings of each phase are excited in a predetermined order from this position to operate as a commutatorless motor.