JPH0519832A - Control method for nc machine tool - Google Patents

Abstract

PURPOSE:To provide highly precise control at low cost only by an NC device for three-axis control without requiring programming which requires a long time and much labor for NC over the each-time reciprocation of a table and the fine feeding of a tool when machining is carried out while the reciprocation of the table and the fine feeding of the tool in each reciprocating operation are alternated synchronously with the control shaft of the NC machine tool. CONSTITUTION:The NC device 6 which has an each-time rotary feeding function provided in a speed command part 14, a tool diameter offset function provided in a program decoding and execution part 13, and a position comparing and position signal output function provided in a position comparison and position signal output part 11 is provided with a synchronizing signal generation part 12; and a signal generated by deciding that the table is positioned at either end of a reciprocal motion range is inputted to output a synchronizing signal signal to that when a main shaft makes one turn by the position detection part 10 of the NC device 6 and only the target position of the tool is inputted to the input operation part 7 of the NC device 6 to divide the movement quantity of the tool into fine feed of each reciprocating operation of the table, thereby performing a series of machining operation for a discontinuous shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an NC machine tool having a table in a main body of a machine tool and a spindle having a tool movable in a plane perpendicular to the moving direction of the table.

[0002]

2. Description of the Related Art Conventionally, when machining is performed by alternately synchronizing the reciprocating motion of a table and the micro-feed of the tool for each reciprocating motion of the table with the control axis of an NC machine tool, the reciprocating motion of the table and the micro-movement of the tool are performed every time. It is necessary to program the feed to the NC device, this method consumes a great deal of time and labor for programming, and it is not practical because grinding wheel diameter correction cannot be used in machining of discontinuous shapes, and it is not possible to use an external automatic programming device. I had to do some programming. As another method, it is difficult to control the reciprocating range and speed of the reciprocating motion of the table, and a complicated mechanism is required.
There was also a method using a hydraulic cylinder or a cam mechanism that was not the control axis. Further, a method of controlling a servomotor using a sequencer, which requires a special mechanical / electrical mechanism for that purpose, has also been used.

[0003]

When processing a 2.5-dimensional work 1 having a series of discontinuous cross sections as shown in FIG. 1, a circle having a grindstone tip R as shown in FIG. Using the plate-shaped grindstone 2 as a tool, as shown in FIG.
In step 5, the reciprocating motion of the table and the micro-feed of the tool were alternately repeated along the tool offset path, and the movement trajectory of the tool was as shown in FIG. There are several methods to realize this processing, but the problems will be described next. 1. A method of programming reciprocating motions of all tables and movement commands to tool micro feed positions in the NC. In this method, it is necessary to create a tool offset path from the workpiece machining shape shown in FIG. 3, calculate each minute feed position, and create an NC program for reciprocating the table and minute feed to each of those positions. In general, the minute feed of the tool is one tenths of the value of the tool tip R, and the tool radius offset function of NC cannot be used to calculate the tool offset path, and the program becomes huge. , It was necessary to introduce an automatic computer programming system.

2. A method of reciprocating the table with a hydraulic cylinder or cam mechanism. In this method, the range and speed of the reciprocating motion of the table need to be variable, but it is difficult to control these changes, and a complicated mechanism is required for the hydraulic circuit and the cam mechanism. In addition, it was not possible to perform machining to interpolate between the position of the table during reciprocating motion and the tool position. 3. A method of controlling a servo motor using a sequencer. With this method, the range and speed of the table reciprocation can be controlled with high precision with respect to the set values, but it was necessary to add a module for controlling the servo motor to the sequencer. Further, even with this method, it is not possible to perform processing for performing interpolation between the reciprocating position of the table and the tool position.

Therefore, an object of the present invention is to reciprocate the table every time when machining is performed by alternately synchronizing the reciprocating motion of the table and the minute feed of the tool for each reciprocating motion of the table by the control axis of the NC machine tool. And the minute feed of the tool does not require NC time-consuming programming, and the reciprocating motion of the table does not depend on the hydraulic cylinder or cam mechanism that is not the NC control axis, and there is no special mechanical NC of 3-axis control without controlling the servo motor using the sequencer required by the electric mechanism
An NC machine tool that can provide high-precision control at a low cost by using only the device, and that makes the machining program to be created extremely small and simple to save the preparation time and labor for training and daily machining. It is to provide a control method of.

[0006]

Therefore, the present invention has solved the above-mentioned problems by providing a control method for an NC machine tool as set forth in the claims.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIGS. FIG. 5 is a block diagram showing a configuration of an NC machine tool used in an NC machine tool control method according to an embodiment of the present invention. The NC machine tool includes a main body 5 and a table 3.
And a spindle 4 having a tool 2 movable in a plane perpendicular to the direction of movement of the table. FIG. 6 shows an N used in a method for controlling a NC machine tool according to an embodiment of the present invention.
It is a block diagram which shows the structure of C apparatus. The table reciprocating shaft and the tool moving shaft for machining a series of discontinuous shapes are all servo motors MZ, M controlled by the NC device 6.
It is driven by Y, MX and a feed screw (not shown).

The table 3 reciprocating motion is determined by the input operation unit 7 of the NC device 6 so that the double motion of the table 3 and the small movement of the tool 2 are alternately repeated. The minute feed amount of the tool 2 for each reciprocating table, the value of the tool tip R of the tool, the moving speed of the tool when the reciprocating table is not performed, and the like are input. These are stored in the data storage unit 8 of the device. The NC program for machining (hereinafter referred to as machining program) is a linear interpolation or circular interpolation command for the target position of the tool when there is no reciprocating motion of the table and micro feed of the tool. It is stored in the program storage unit 9 of the NC device 6.

The position of the table 3 is monitored by the position detection unit 10 in the NC device 6 by a movement signal from the position detector EX, and the table position is compared with the position and position signal output unit 11 in the NC device. Are constantly compared with the table reciprocating range of the data storage section 8, and the synchronization signal creating section 12 is notified immediately when the table position reaches both ends of the reciprocating range. In response to this notification, the synchronization signal creation unit 12 inputs the same signal as when the main shaft makes one rotation to the main shaft input of the position detection unit 10. Reference numeral 13 is a program decoding and execution unit, and 14 is a speed command unit.

A control method for an NC machine tool according to an embodiment of the present invention will be described. A minute movement command of the tool per one rotation of the spindle is commanded from the input target position of the tool provided in the speed command section 14. , The rotary feed function, the tool diameter offset function provided in the program decoding and execution unit 13, and the position during the table reciprocating motion provided in the position comparison and position signal output unit 11, the table 3 reciprocates The NC device 6 having a position comparison and position signal output function for determining that the position is located at both ends of the moving range and outputting a signal is used. By inputting a signal from the signal output unit 11 that determines that the table is located at both ends of the reciprocating range,
By causing the position detection unit 10 of the NC device 6 to output the same synchronization signal as when the main shaft makes one revolution and inputting only the target position of the tool to the input operation unit 7 of the NC device 6, the tool movement amount is A method for controlling an NC machine tool, characterized in that the table is divided into minute feeds for each reciprocating movement, and the reciprocating movement of the table and the minute feeding of a tool are alternately repeated to perform a series of discontinuous shape machining. It is what

That is, when the tool movement is started, the amount of tool movement is divided into minute feeds for each forward and backward movement of the table, and when the machine is started, an initialization program prepared in advance causes the cutting feed motor to rotate feed for each spindle. After the mode is set, the reciprocating motion of the table 3 is started based on the data stored in the data storage unit 8. After that, the reciprocating motion of the table 3 is continued until the table reciprocating motion stop command is executed at the end of machining. Repeats reciprocating motion. After that, the initialization program calls the machining program and the movement of the tool is executed, but it does not move until the rotation signal of the main spindle 4 is input because of the every rotation feed mode.

On the other hand, the position of the table is monitored by the position detection unit 10 in the apparatus by a movement signal from the position detector EX, and the table position is stored in the position comparison and position signal output unit 11 in the NC device 6 as data storage. The table reciprocating range of the unit 8 is constantly compared, and the synchronization signal creating unit 12 is notified immediately when the table position reaches both ends of the reciprocating range. In response to this notification, the synchronization signal generator 12 inputs the same signal as when the main spindle 4 makes one revolution to the main spindle input of the position detector 10. As a result, the speed command unit 14 commands the movement on the tool offset path by using the minute feed amount of the tool for each reciprocating motion of the table in the data storage unit 8 as the movement amount per one rotation of the spindle. As a result, the reciprocating motion of the table and the minute feed of the tool are performed until the target position of the tool offset path of the execution block is reached, and when the target position is reached, the next block is executed and repeated until the end of the machining program.

When the machining program ends, the initialization program is returned to, and when the table reciprocating motion stop command is issued, the table is stopped after returning to the reciprocating motion start position, and the cutting feed mode is set to the feed mode per minute without the table reciprocating motion. Return the tool to its initial position and stop the machine. When the table reciprocation is set not to be performed from the input operation unit 7 of the NC device 6, the cutting speed of the tool is used when the table reciprocation is not performed, and the machining is performed in the cutting mode of the feed per minute without the table reciprocation. It is possible to do with a single program with the previous machining program.

In a profile surface grinding machine as shown in FIG. 5 for 2.5-dimensional processing of precision molds and chips,
An example of the contents of the machining program for machining the shape of the work 1 as shown in FIG. 3 is shown below. The content in () is the instruction content. 01 (Program number) G41 G01 YP1y ZP1z (Whetstone diameter offset right command and cutting command to P1) YP2y ZP2z (Cutting command to P2) G02 YP3y ZP3z RP3r (Cutting command to P3) G03 YP4y To ZP4z RP4 Cutting command) G01 YP5y ZP5z (Cutting command to P5) M99 (End of program)

[0015]

As described above, according to the present invention, when machining is performed by alternately reciprocating the table and minute feed of the tool for each reciprocating motion of the table by the control axis of the NC machine tool. Each time the table reciprocates and the minute feed of the tool does not require a lot of time and labor for the NC programming, and the table reciprocation does not depend on the hydraulic cylinder or the cam mechanism which is not the NC control axis,
In addition, without controlling the servo motor using a sequencer, high-precision control can be provided at a low cost by using only NC with three-axis control, and the machining program to be created is very small and simple, and training is possible. Also, it is possible to provide a control method for an NC machine tool that saves preparation time and labor in daily machining.

[Brief description of drawings]

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 2.5 of a series of discontinuous shaped cross-sections machined using the NC machine tool control method of one embodiment of the present invention.
The perspective view of the three-dimensional work.

2 is a side view of a disk-shaped grindstone having a grindstone tip R which is a tool used for the work of FIG. 1 and an enlarged view of a grindstone tip R portion.

3 is a tool for machining the work of FIG. 1, P1 to P5
Explanatory drawing which shows the offset path | route of the tool which performs the process which repeats the reciprocating motion of a table | table and the micro feed of a tool alternately.

4] P1 to P5 of a tool for machining the work of FIG.
Explanatory drawing which shows the movement locus | trajectory of the tool which performs the process which repeats the reciprocating motion of a table | table and the micro feed of a tool alternately.

FIG. 5 is a block diagram showing a configuration of an NC machine tool used in an NC machine tool control method according to an embodiment of the present invention.

FIG. 6 is a block diagram showing the configuration of an NC device used in a method for controlling an NC machine tool according to an embodiment of the present invention.

[Explanation of symbols]

 1. ． Work 2. ． Tool 3. ． Table 4. ． Spindle 5. ． Main body 6. ． NC device 7. ． Input operation unit 10. ． Position detection unit 11. ． Position comparison and position signal output unit 12. ． Synchronization signal creation unit 13. ． Program decoding and execution unit 14. ． Speed command section

Claims (1)

Claim: What is claimed is: 1. An NC machine tool having a table in a main body of a machine tool and a spindle having a tool movable in a plane perpendicular to a moving direction of the table. A per-revolution feed function, which is provided in the speed command section, for issuing a command for minute movement of the tool per one rotation of the spindle from the input target position of the tool. Tool diameter offset function provided in the program decoding and execution unit, and c. An NC having a position comparison and position signal output function, which is provided in the position comparison and position signal output unit, and which outputs a signal by determining that the position of the table during reciprocating motion is located at both ends of the reciprocating range. Using the device, d. The synchronization signal generating section is provided in the NC device, and a signal from the position comparing and position signal outputting section that determines that the table is located at both ends of the reciprocating range is input, and the spindle rotates once. Of the sync signal of the NC device to the position detection unit of the NC device, and By inputting only the target position of the tool to the input operation unit of the NC device, the tool movement amount is divided into minute feeds for each reciprocating movement of the table, and reciprocating movement of the table and minute feeding of the tool are performed. A method for controlling an NC machine tool, characterized in that a series of discontinuous shapes are machined by alternately repeating the above.