JPS61280778A - Motor controlling method - Google Patents

Abstract

PURPOSE:To eliminate an extremely low speed operating auxiliary drive device by controlling to switch an inverter by continuous and extremely low speed operating logic circuit. CONSTITUTION:When a machine is started, an extremely low speed operating logic circuit 14 is connected with an inverter 4 by switching means. Thus, the output current of the inverter 4 rises according to a command of the logic circuit 14 until the extremely low speed rotation waveform of a motor becomes a preferable waveform. Then, the switching means operates to interrupt the logic circuit 14 and the inverter 4, a continuous operation logic circuit 10 is connected with the inverter 4, and a motor 2 is switched to the normal continuous operation control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of controlling a motor that drives a printing machine or a loom.

[Conventional technology]

Conventionally, the rotation of motors that drive machines such as printing presses and looms has been controlled using inverters.

In this case 1: With a normal inverter, it is difficult to overcome the static friction of the machine and generate torque to the motor in the machine's slow-speed operation range, so a separate auxiliary drive device for slow-speed operation is prepared. was driving this drive.

[Problem that the invention seeks to solve]

As mentioned above, if a separate drive device is provided for the slow operating range of the machine, there is a drawback in that the cost of the entire device increases.

The present invention aims to eliminate the above-mentioned defects.

[Means to solve problems]

To achieve the above object, the present invention provides a method for controlling an inverter circuit according to commands from a logic circuit, and controlling the rotation speed and torque of a motor connected to the inverter circuit, including connecting a slow-speed logic circuit to the inverter circuit; When the motor is in fine-speed operation, the amount of voltage supplied to the motor is increased for a short period of time according to a command from the slow-speed logic circuit until the motor is in a good slow-speed rotation state.

[Effect]

When the motor that drives a machine such as a loom, a large voltage is supplied from the inverter circuit for a short period of time at the start of the drive according to a command from the slow-speed logic circuit, and the motor overcomes the static friction of the machine and generates torque. occurs, the motor smoothly rotates at a slow speed, and then shifts to a continuous operation state according to a command from another continuous operation logic circuit 6 [Embodiment] Please refer to an embodiment of the configuration of the present invention shown in the attached drawings below. This will be explained in detail.

In FIG. 1, 2 is a motor and 4 is an inverter circuit, which are connected to a converter bridge circuit (not shown). The inverter circuit 4 includes a PWM (pulse width modulation) carrier oscillation circuit 6 and a V/F pattern oscillation circuit 8.
It consists of Logic episode for continuous operation lol! r10 is connected. 12 is a speed setting input means, 14 is a logic circuit for slow speed operation, and 4 carrier oscillation circuit 16 is connected to PW.
and a V/F pattern oscillation circuit 18.

Reference numeral 24 denotes a brake-dedicated logic circuit, which is composed of a PWM carrier oscillation circuit 20 and a V/F pattern oscillation circuit 22. The logic circuits 10, 14. ．． 24 is connected to the speed setting input means 12 via a known switching means.

Next, the operation of this embodiment will be explained.

When starting the machine, the switching means connects the logic circuit 14 for slow operation to the inverter circuit 4, and the logic circuit 10 for continuous operation and the inverter circuit 4 are cut off. In this state, in a short period of time, the output current of the inverter circuit 4 increases according to the command of the slow-speed logic rotation 14 until the slow-speed rotation waveform of the motor becomes a good waveform. As a result, torque is generated in the motor to overcome the static friction of the machine, and the machine is smoothly driven to rotate at a very slow speed. Next, the switching means operates to disconnect the logic circuit 14 for slow operation and the inverter circuit 4, and the logic circuit 1 for continuous operation
0 is connected to the inverter circuit 4, and the motor 2 is switched to normal continuous operation control. When the motor 2 is stopped, the electromagnetic brake (not shown) is turned on, but at this time, the brake-specific logic connects to the inverter 4, instantly sets the inverter 4 to zero hertz, and applies direct current to the motor 2. The machine is set to effectively stop a machine such as a loom.

〔effect〕

As described above, in the present invention, the inverter circuit is switched and controlled by the logic circuit for continuous operation and slow-speed operation, so that it is possible to control the slow-speed inching operation of machines such as looms with an inexpensive device. Exists.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an electronic circuit block, and FIG. 2 is an explanatory diagram of a motor torque waveform. 2...Motor, 4...Inverter circuit. 6...PWM carrier oscillation times wr. 8...V/F pattern oscillation circuit. 10...Logic circuit, 12...Speed setting input means, 14...Logic circuit, 16...
・PWM carrier oscillation circuit, 18°°°. V/F pattern oscillation circuit

Claims (1)

[Claims] 1. In a method for controlling an inverter circuit according to commands from a logic circuit to control the rotational speed and torque of a motor connected to the inverter circuit, a slow-speed logic circuit is connected to the inverter circuit, and the motor A motor control method characterized in that during fine-speed operation, the amount of voltage supplied to the motor is increased in response to a command from the fine-speed logic circuit until the motor reaches a good fine-speed rotation state.