JPS605157B2 - Pulse motor drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse motor drive device, and particularly to prevention of step-out.

Conventional devices that use a stopper to position an object driven by a pulse mower outside have the following drawbacks.

In other words, the characteristic diagram in Figure 1 shows the relationship between the torque and rotation angle of the pulse motor, and in Figure a, the torque of the pulse motor is distributed in a sinusoidal manner with respect to the rotation angle, depending on the excitation state of the pulse motor. The slope of the torque becomes one region A and ten regions B, which appear alternately. In region A of -, the motor always tries to move toward the equilibrium point ○- due to the generation of torque and is stable, but in region B of 10, the direction of torque generation deviates from the equilibrium point ○1 and is unstable. be. Normally, the load angle refers to the difference between this stable equilibrium point 0- and the rotational position of the motor, and it is said that when the load angle exceeds ±m/2, it enters an unstable region. Next, as shown in Figure 1b, when the pulse motor is rotating while generating torque by changing the excitation state from a to b according to the input pulse, the object to be driven, for example, the turret, When the motor collides with the stopper, the motor stops, and the excitation state changes from c to d to e due to the input pulse, and negative torque is generated in the motor, causing the motor to step out.

This shortens the life of the cutter and causes variations in the accuracy of machining performed by the cutter. In view of the above drawbacks, the present invention detects the load angle of the pulse motor and limits this load angle to prevent the pulse motor from stepping out and to reduce the torque generated when the pulse motor stops rotating. The aim is to make management simple and inexpensive.

Hereinafter, one embodiment of the pulse motor drive device according to the present invention will be described with reference to the characteristic diagram in FIG. 2 and the block diagrams in FIGS. 3 and 4.

That is, in FIG. 3, 1 is a pulse oscillator, 1' is an input pulse train generated from this pulse oscillator 1, and this pulse train is passed through an OR circuit to a load angular force generator that detects the load angle at the same time as the pulse motor drive source 2. 3 is also input.

Reference numeral 3' denotes an output section for outputting upper and lower limit value signals of the load angular force sensor, and the pulse motor drive source 2 changes its excitation state in accordance with the input pulse train 1' to rotate the pulse motor 4. A pulse oscillator 5 is connected to the pulse motor 4, and this pulse oscillator generates a pulse train 5' according to the rotation of the pulse motor 4.

This pulse train 5' is separated into pulses in two directions by a two-phase pulse separation circuit 7, and fed back to the load angle force detector 3, where the load angle is detected. Therefore, it is desirable that the resolution of the pulse oscillator 5 and the resolution of the excitation state of the pulse motor drive source 2 be equal and sufficiently large. A dummy pulse oscillator 6 outputs a load angle limiting pulse 6' to the load angle force counter 3 and the pulse motor drive source 2 via an AND circuit in response to the load angle upper and lower limit values 8 and 8'.
Since the pulse motor drive device according to the present invention is configured as described above, when the input pulse train 1' is input from the pulse oscillator 1, the pulse motor 4 is stopped, and the pulse train 5 is output from the pulse oscillator 5. When ' is not output, the load angle of the pulse motor 4 is c' as shown in Figure 2.
→d'→e', and when the load angle reaches the upper limit 8, a load angle limiting pulse 6' is output from the dummy pulse oscillator 6 and input to the pulse motor drive source 2 and load angle force detector 3, respectively.

As a result, the load angle is restored to e'→d'. Since the input pulse train 1' is inputted from the pulse oscillator 1, the load angle becomes d'→e' again, and similarly, when the load angle limit value is reached, the load angle limit pulse causes the load angle to become e'→. That is, as long as the input pulse train 1' is generated from the pulse oscillator 1, the state of Ze' is manipulated and the pulse motor 4
In addition to limiting the torque of the motor, it is also possible to prevent the pulse motor from stepping out. The same aircraft also applies when the load angle is limited to the lower limit value 8'.

In the above embodiment, a dummy pulse oscillator was provided, and the load angle was limited by the load angle limiting pulse output from the dummy pulse oscillator.As shown in FIG. 4, the input pulse train 1' output from the pulse oscillator 1 , NAND
It goes without saying that the load angle can be limited by providing a circuit and stopping the motor by outputting the load angle limit values 8 and 8'.

As described above, according to the present invention, by limiting the torque of the pulse motor, step-out can be prevented, the life of driven objects, especially blades, can be extended, and machining accuracy can be significantly improved. Since limit values can be easily set, processing conditions can be easily managed.

[Brief explanation of the drawing]

FIG. 1 is a torque-to-rotation angle characteristic diagram of a pulse motor of a conventional device, FIG. 2 is a torque-to-rotation angle characteristic diagram of a pulse motor drive device according to the present invention, and FIGS. 3 and 4 are diagrams of a pulse motor according to the present invention. It is a block diagram showing a drive device. 1: Pulse oscillator, 1': Input pulse train, 2: Pulse motor drive source, 3: Load angle force counter, 3': Load angle upper and lower limit value output section, 4: Pulse motor, 5: Pulse oscillator, 5'
: Output pulse train, 6: Dummy pulse oscillator, 6': Load angle limiting pulse, 7: Two-phase pulse separation circuit, 8, 8': Load angle upper and lower limit values. In the diagram, the same symbols indicate the same or equivalent parts. shows. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 A pulse oscillator that oscillates pulses, a motor drive source that inputs drive pulses based on the pulses to drive the pulse motor, a pulse oscillator that generates a pulse train according to the rotation of the pulse motor, and a pulse oscillator that transmits the pulse train in two directions. a two-phase pulse separation circuit that separates the pulses into pulses; an OR circuit that receives an inverted input of the output pulse from the two-phase pulse separation circuit and the drive pulse to the motor drive source and obtains an OR output;
A load angle counter detects the load angle of the pulse motor based on the output of the R circuit, and an upper limit value and a lower limit value of the load angle are set, and when the detected load angle is about to exceed the limit value, the corresponding A pulse motor drive device comprising: a load angle upper and lower limit value output unit that limits a load angle by sending out an output that stops the drive pulse in a direction responsive to the limit value.