KR20000046977A - Method for controlling speed command signal of built-in spindle motor in machining center - Google Patents

Abstract

PURPOSE: A method is provided to reduce unnecessary mechanical and electrical impacts of the switching apparatus, which controls the motor having two winding coils for high and low speed, by applying the desired speed command signal only to the selected winding coil. CONSTITUTION: A motor equips two switching apparatus for controlling the winding coils respectively. The speed command data is stored into an address for speed command when receiving the main power and speed command. The stored one is compared to a reference data. If it is less or equal to the reference data, the turning flag and the switching signal for corresponding coil are turned off to turn on the switching apparatus for high speed so the motor keeps high speed. If the switching apparatus is turned on after receiving the main power, the switching operation is not performed. In next, if the one is greater than the reference data, the flag and the switching signal are turned on to turn on the switching apparatus for low speed so the motor keeps slow speed. The motor keeps the present speed until new speed command signal is received.

Description

Control method of speed command switching of built-in spindle motor of machine tool

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for controlling the speed command input of a built-in spindle motor for machine tools. Specifically, the present invention relates to a low speed and high speed winding in a built-in spindle motor applied to a high speed machine tool. In the case of external speed control through numerical control, the speed command input control method is used to execute the winding switching of low speed and high speed which is mechanically or electrically stable.

In general, the spindle motor has only one field coil (Stator Coil), so it is difficult to obtain a constant rotational speed in a wide range of rotation. There was a problem that the processing of becomes impossible.

Therefore, the spindle motor itself uses a built-in spindle motor composed of a low-speed winding and a high-speed winding so that the field winding of the motor maintains a constant rotational speed even at a high speed rotation.

As shown in FIG. 1, the built-in spindle motor has a built-in spindle together with a signal of the built-in spindle motor driver 3 when an electrical winding switching signal is input to the low-speed electronic switch 2 by the electrical relay 1. When it is transmitted to the low speed winding 4 of the motor and input to the high speed electromagnetic switch 2 ', the signal is transmitted to the high speed winding 4' of the built-in spindle with the signal of the built-in spindle motor driver 3 to control the winding switching. Configured to perform.

The programmable machine controller and the signal transmission method of the numerical control period for performing the winding switching control are shown in FIG.

When the winding switching request signal 10 is output from the programmable controller 200 to the numerical controller 100, the low speed and high speed areas are selected according to ON / OFF,

When the power line state confirmation signal 20 is output from the programmable controller 200 to the numerical controller 100, the numerical controller 100 informs the controller 100 of the low speed and high speed state according to ON / OFF. ,

When the power line switching signal 30 is output to the mechanical controller 200 that can be programmed in the numerical controller 100, the power line switching signal 30 is used as a switch signal for selecting a low speed and a high speed area according to ON / OFF,

When the speed detection signal 40 is output to the mechanical controller 200 which can be programmed by the numerical controller 100, it is confirmed that the motor speed fed back according to ON / OFF is more than or less than the switching point of the switching point. It is configured to output.

In the signal transmission method for performing the winding switching control configured as described above, when the winding switching request signal 10 is turned off, that is, there is a selection request for the high speed region, and when this is confirmed, the power line switching signal 30 is turned on. In the off state, when the winding switching request signal 10 is turned on, that is, there is a selection request of the low speed region, and when this is confirmed, the winding of the power line switching signal 30 is turned from the off state to the on state, and the speed is changed. The detection signal 40 confirms that the motor speed is above or below the switching point.

Referring to the conventional winding switching control as shown in the flow chart of Figure 3 based on the transmission method of the signals

Step S1 of turning on the speed detection signal when power is input;

Turning the winding switching signal on (S2);

Turning on the power line switching signal (S3);

Rotating the spindle when the speed command is input (S4);

Receiving the actual speed of the rotating spindle and comparing the actual speed of the spindle motor with the speed change point (S5);

If the actual speed is less than or equal to the switching point, the speed detection signal is turned off (S6);

Turning off the winding switching signal (S7);

Turning off the power line switching signal (S8);

If the actual speed is larger than the switching point, the speed detection signal is kept on (S9).

Therefore, the operation of the conventional winding switching control is as follows.

When the power is input, the speed detection signal detects the low speed area because the spindle motor is in the stopped state, and outputs the winding change signal and the power line change signal ON so that the low speed area is selected. (S1) (S2) (S3)

When the speed command is input in the low speed region, the spindle rotates to receive the actual speed that is rotated, and compares the actual speed of the spindle motor with the speed change point. It turns off and switches the electronic switch to high speed and outputs it to the numerical controller. (S4) (S5)

If the actual speed is greater than the switching point, the winding switching is controlled by maintaining the speed detection signal on to maintain the electronic switch at a low speed and feeding back to check whether the actual speed passes the switching point. )

In this method, when the switching operation is performed by the speed sensing signal, the machining is performed near the switching point, and if the actual speed to be fed back according to the load change during the machining is changed, the speed switching operation is frequently performed. The low and high speed electronic switch is frequently changed due to the change of feed speed, which affects the feed speed. Therefore, if the user operates the override switch for spindle speed control drastically, the high and low speed and high speed switchgear can be turned on and off. In addition to the switch itself, there was a problem of giving electrical and mechanical shocks to the peripheral electrical devices.

An object of the present invention is to implement a mechanically or electrically stable low speed and high speed winding switching when external speed control is performed through numerical control with a low speed and a high speed winding in a built-in spindle motor applied to a high speed machine tool. It is to provide a command input control method.

In order to achieve the above object, it is compared with a given speed detection level of the machine controller which can be programmed only when the user inputs a new command for the corresponding speed range, and it is determined which area, and accordingly the winding switching is performed, so that more stable winding To provide a conversion method.

1 is an electric circuit diagram for performing winding switching control of a built-in spindle motor;

2 is a simplified block diagram showing a transmission method of a mechanical controller and a numerical control period which can be programmed to perform winding switching control;

3 is a flowchart illustrating a control method of a conventional winding switching circuit;

4 is a flowchart showing the winding switching control method of the speed command of the present invention.

Explanation of symbols for the main parts of the drawings

1: relay 2: low speed electronic switch

2 ': High speed electronic switch 3: Driver for built-in spindle motor

4: low speed winding 4 ': high speed winding

10: winding change request signal 20: power line check status signal

30: power line switching signal 40: speed detection signal

100: numerical controller 200: programmable machine controller

The present invention, as shown in the flowchart of Figure 4, as a method for achieving the above object, the configuration of the input control method for switching the winding of the low speed and high speed by determining the speed detection level in the programmable machine controller

Turning on the high-speed winding switch when power is input (S10);

When the speed command is input, rotating the spindle to store the commanded speed value in the speed command address (S20);

Comparing the speed command value stored in the speed command address with a switching point reference value (S30);

When the speed command value is less than or equal to the reference value which is the switching port, the switching flag is turned off (S40);

Turning off the winding switching signal (S50);

Turning off the power line switching signal (S60);

When the speed command value is larger than the reference value of the changeover port, the switching flag is turned on (S70);

Turning the winding switching signal on (S80);

The power line switching signal is configured to turn on (S90).

The operation of the input control method for switching the winding of the low speed and the high speed by determining the speed sensing level of the present invention configured as described above is as follows.

Before the power is input, the built-in spindle motor parameter of numerical control is inputted to convert the value of the feedback speed detection level controlled by the numerical controller itself as a percentage and to a certain RPM (REVOLUTION) at the maximum value of the motor. PER MINUTE) and input the comparison data into the machine controller that can be programmed to set the conversion point reference value.

For example, if the built-in spindle motor parameter is 217 and the maximum rotational speed is 12000 RPM, converting the built-in spindle motor parameter 217 as a percentage converts the speed of 21.7% of the maximum speed into a turning point and finally 12000/217 = 2600 RPM. The conversion point reference value is set.

Therefore, when power is input, since there is no spindle speed command, the high-speed winding switch which is generally the default (DEFAULT) turns on. (S10)

If the user waits for the spindle speed command and the speed command is input, the speed value of the commanded spindle is stored in the speed command address (S20).

The final speed value stored in the speed command address is compared with the change point reference value.

If the speed command value is smaller than or equal to the reference value of the changeover port, the switching flag is turned off and the winding changeover signal is turned off to select the high speed range. Therefore, the power line changeover signal is turned off to maintain the high-speed area electromagnetic switch. Will be. If the high-speed switch is turned on after the power input, the switch switching operation does not occur. (S30) (S40) (S50) (S60)

If the speed command value is larger than the reference value of the changeover port, the switching flag is turned on, the winding changeover signal is turned on, and the low speed range is selected so that the power line changeover signal is turned on. The switching operation takes place. That is, the high speed winding switch is turned off and the low speed winding switch is turned on. (S30) (S70) (S80) (S90)

If the input of the speed command is confirmed, the routine is executed repeatedly. If not, the operation is continued in the selected winding.

As described above, the present invention performs winding switching control corresponding to low speed and high speed in the built-in spindle, that is, according to the user's speed command, thereby avoiding frequent large-capacity switch operation, reducing mechanical and electrical shock, and winding winding during processing. There is an effect that can improve the quality of the processing by preventing it from performing.

Claims (1)

Turning on the high-speed winding switch when power is input (S10); When the speed command is input, rotating the spindle and storing the commanded speed value in the speed command address (S20); Comparing the speed command value stored in the speed command address with a switching point reference value (S30); If the speed command value is less than or equal to the reference value of the changeover port, turning off the switch flag (S40); Turning off the winding switching signal (S50); Turning off the power line switching signal (S60); When the speed command value is larger than the reference value of the changeover port, turning on the switch flag (S70); Turning the winding switching signal on (S80); The control method of the speed command of the built-in spindle motor of the machine tool, characterized in that the power line switching signal is turned on (S90).