JPH0275004A - Spindle control system - Google Patents

Abstract

PURPOSE:To decrease the number of servo motors by using a servo motor as a spindle or a feed shaft and switching these two axes with an NC command. CONSTITUTION:A servo motor 5 is used as a spindle or a feed shaft by switching, and a revolution command 2 or a movement command 1 is selected via an NC command. Then the motor 5 is controlled by the NC command as a spindle or a feed shaft. As a result, the number of motors 5 is decreased and the reduction of cost is attained in a spindle control system.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a spindle control system in which a single servo motor is used by switching between a feed axis and a main spindle, and particularly to a spindle control system for a machine tool having a small sub-spindle. Regarding.

[Conventional technology]

One CNC machine tool performs complex machining, and attempts are made to perform as much of the machining required for one workpiece as possible with a single CNC machine tool.

This is because time for attaching and detaching workpieces, setting tools, etc. can be saved.

For this reason, many CNC machine tools are designed to have a rotation axis called a sub-spindle in addition to the main spindle.For example,
The CNC lathe has a main spindle for rotating the workpiece, and a sub-spindle for small drilling and simple milling. In these CNC machine tools,
In addition to the Z-axis, there is an auxiliary axis that controls the movement of the sub-main axis.

[Problem to be solved by the invention]

However, generally these sub-spindles and auxiliary axes rarely operate at the same time; for example, table indexing, magazine rotation axes, etc. do not operate simultaneously with the sub-spindle. Furthermore, the output of the sub-spindle is generally small.

The present invention has been made in view of these points, and has the following features:
The purpose of the present invention is to provide a spindle control system in which a servo motor on a stand is switched between the spindle and the feed axis.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a spindle control system in which one servo motor is used by switching between a feed axis and a main axis. A spindle control method is provided, characterized in that the servo motor is controlled as a spindle or a feed axis by the NC instruction.

(Function) One servo motor is used as the main shaft or feed shaft 7. The switching is performed by an NC command.

This allows the number of servo motors to be reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Figure 1 shows a block diagram of the spindle control system of the present invention.
When the servo motor 5 is used to feed the auxiliary axis by the C command, a position command 1 is commanded. At this time, an address specifying the auxiliary axis is specified. When it is desired to use the servo motor 5 as a sub-spindle, a specific G code and rotation speed are commanded. For example, command G--31500:. This command is given to the servo control circuit 3,
If there is a position command, the servo control circuit 3 receives a position feedback pulse from the servo control circuit 5 and performs position control. Furthermore, when a command is given to use the spindle as a sub-spindle, only rotation control is performed. As the servo control circuit 3, a digital servo control circuit is used.

The command is sent to the servo amplifier 4 and drives the servo motor 5. When the servo motor 5 is used as an auxiliary shaft, it is coupled to the feed shaft by a clutch (not shown). Moreover, when used as a sub-main shaft, it is coupled to the sub-main shaft by a clutch. This clutch can be controlled by automatically outputting a switching signal in response to a position command or a main shaft command, or by using a special auxiliary (M) function.

Further, since such a sub-main axis or auxiliary axis is often controlled by a PMC (programmable machine controller) or the like, it may be switched by a sequence program of the PMC.

FIG. 2 shows a schematic flowchart of the spindle control method of the present invention. In the figure, the number following S indicates the step number.

[S1] Check if it is a sub-spindle command, and if it is a sub-spindle command, go to S2.
If it is a position command, go to S3.

[S2] Create a speed command for the commanded rotation speed.

[S3] Create a movement command.

[S4] Output a position or speed command to each servo control circuit.

In this way, even one servo motor can be used to control the auxiliary shaft and the sub-main shaft, reducing costs.

Although the above example has been explained using a sub-spindle and an auxiliary shaft, the present invention is not limited thereto, and can be similarly applied to a normal main spindle and feed shaft as long as the output is small.

〔Effect of the invention〕

As explained above, in the present invention, the servo motor is used by switching between the main shaft and the feed shaft, so the number of servo motors is reduced and the cost is reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the spindle control method of the present invention, and FIG. 2 is a schematic flowchart of the spindle control method of the present invention. 1・−−１１−−−−・−・−Position command 2−・−１１１−−・−Spindle command 3−−−−−−−−−−−− Servo control circuit 4−−−−
−−・−・−−−−−Servo amplifier 5−・−1−−−−
--- Servo motor patent applicant Fanuc Co., Ltd. agent Patent attorney Takeshi Hattori Figure 2, Figure 1v

Claims (2)

[Claims] (1) In a spindle control method in which one servo motor is used by switching between the feed axis and the main axis, an NC command is used to issue either a rotation command or a movement command, and the NC command causes the servo motor to function as the main axis or the feed axis. A spindle control method characterized by the control. (2) The spindle control system according to claim 1, wherein the instruction for the spindle is given using a G code.