JPH0746287B2 - Numerical control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial application field" The present invention relates to a numerical control device for machine tools (hereinafter referred to as NC device).
Regarding

"Conventional technology" NC device commands include axis movement commands (X, Y, Z commands) to move a table or tool, auxiliary function commands (M commands), spindle function commands (S commands), and tool commands. There is an MST instruction of (T instruction). For example, an automatic tool changer (hereinafter referred to as an ATC device) is operated by a T function command to selectively replace a desired tool, and the S function command changes the rotational speed of the spindle to a commanded rotational speed. The operation time required for exchanging tools and changing the spindle rotational speed is the non-cutting time that does not contribute to the cutting of the workpiece.

In order to reduce the non-cutting time, a numerical control system and a numerical control device that execute two instructions in parallel without interfering with the operation of a machine are disclosed in JP-A-57-90705 and JP-A-63-143607, respectively. It is disclosed by the publication.

[Problems to be Solved by the Invention] In the above numerical control method, after the operation of the machine caused by the command of a predetermined block is completed, the operation is shifted to the execution of the next block, or the completion of the operation is waited for. Instead, a special command for instructing whether to shift to the execution of the next block is put in the program, and the special command is discriminated to allow the machine to execute a single operation of one block or a parallel operation of a plurality of blocks. It is the one. In this case, the operator must determine whether two instructions can be executed in parallel, and insert a special command instructing parallel execution into the program, which is likely to cause human error in the program. There is a point.

Further, the numerical control device has a table of numerical control codes for executing the next block in the RAM or ROM without waiting for the end of the block (instruction) of the numerical control code, and a block when there is a block which is not completed. When the block to be executed corresponds to the block that executes the next block without waiting for the end of the block, the block to be executed and the next block are parallel. And then executed. In this case, whether two blocks are executed in parallel is determined by discriminating only the preceding one block.

Therefore, for example, if a tool change instruction is registered in a table that executes the next block without waiting for the end, if the tool change instruction is followed by a table positioning instruction, the two instructions will be executed in parallel. However, when the cutting feed command of the table follows the tool change command, the two commands that should not be executed in parallel are executed in parallel. Further, if the tool change instruction is registered in the table that waits for the end of the block when there is an unfinished block, the tool change instruction will not be executed in parallel even if the positioning instructions of the table which can be originally executed in parallel are consecutive. Further, if the tool change command is not registered in any of the above tables, there is a problem that the tool change command and the table positioning command are not executed in parallel even if they are consecutive.

The present invention has been made in order to solve the problems included in the above-mentioned respective prior arts, and can numerically operate by surely determining whether or not two consecutive specific instructions can be executed in parallel. The purpose is to provide.

"Means for Solving Problems" The numerical control device of the present invention for achieving the above-mentioned object generates a machining program in NC language from machining data in which a machining position, machining conditions, etc. are input, and the machining program is generated. In a numerical control device for sequentially controlling the operation of a machine in accordance with the command, whether or not there are two specific commands in succession that do not interfere with the operation even if they are executed simultaneously in the machining program. And a means for causing the machine to operate the two consecutive instructions in parallel according to the result of the determination.

[Operation] According to the above configuration, whether or not there are two specific instructions that do not interfere with the operation even if they are executed simultaneously in the internally generated machining program in NC language,
It discriminates based on the combination of two consecutive instructions, and the two consecutive instructions are executed in parallel according to the discrimination result.

[Examples] Examples of the present invention will be specifically described with reference to the drawings.

FIG. 2 is a front view of a machining center to which the NC device according to the present invention is applied, and FIG. 3 is a side view.

On the front of the column 22 that is placed upright on the base 21, the headstock
23 is mounted so that it can be raised and lowered. Headstock 23 is column 22
It is moved up and down by the Z-axis feed motor 9 provided above.
A spindle 25 is rotatably supported on a spindle headstock 23 and a spindle motor 10
Is driven to rotate. On the other hand, on the base 21, a table 27 on which a workpiece is placed is provided. The table 27 is slidably mounted on the saddle 28 and is movable in the horizontal X-axis direction and the front-back Y-axis direction in a horizontal plane. The table 27 is horizontally moved by the X-axis feed motor 7 and the Y-axis feed motor 8.

A tool changing device 30 (ATC device) is attached to the front surface of the column 22 independently of the headstock 23. The ATC device 30 radially holds 12 tools 32 on a rotatable tool magazine 31, and selects the tools 32 according to the index position of the tool magazine 31,
The tool 32 is exchanged between the spindle 25 and the tool magazine 31.
The tool magazine 31 is an ATC located on the back of the tool magazine 31.
It is rotationally driven by the motor 11.

Feed motor 7,8,9 for each axis, spindle motor 10 and ATC motor 11
AC servomotors are used for each of these and are controlled by the NC device 35 attached to the column 22. The NC device 35 is connected to an operation panel 36 arranged in the front. The operation panel 36 includes a keyboard 37 and a CRT display 38, and an operator can interactively input machining data to the NC device 35.

FIG. 1 is a block diagram showing an NC device 35 according to the present invention. The NC device 35 includes an operation data memory unit 1, an operation data buffer unit 2, an operation execution unit 3, a motor command buffer unit 4, and a motor control unit 5, and the operation execution unit 3 includes a keyboard 37, a CRT display 38, In addition, an external input / output device 6 such as an M command device is connected, and the motor control unit 5 has feed motors 7, 8, 9 for each axis, a spindle motor 10, and an ATC motor 11
, Etc. are connected to the servo motor.

The operation data memory unit 1 stores various machining programs managed by program numbers as files. The operation data buffer unit 2 is a part in which a command code group in NC language necessary for operation is stored, and a part of the machining program of the operation data memory unit 1 is compiled into NC language according to a command from the operation execution unit 3. Is stored. The contents of the operation data buffer unit 2 are sequentially updated according to the end of execution of the instruction code.

The operation execution unit 3 includes a processor unit (CPU),
The M command and the like are output according to the command code of the operation data buffer unit 2 and the command from the input device 6, and data is set in the motor command buffer unit 4 to give a command to the motor control unit 5. The motor command buffer unit 4 is a feed motor
This is a part in which command data for controlling the 7, 8, 9, the spindle motor 10, and the ATC motor 11 is stored.

The motor control unit 5 includes a processor unit (CPU) and controls various servomotors 7, 8, 9, 10, 11 according to command data set in the motor command buffer unit 4.

FIG. 4 is a diagram showing an internal configuration of the motor command buffer unit 4. The command data set in the motor command buffer unit 4 includes X-axis, Y-axis, and Z-axis motor movement command values 44, 45,
46, spindle command data 4 to command forward / reverse rotation of spindle 25, stop
7. In addition to the rotation speed command value 48 of the spindle 25, a tool replacement command value 43 that commands the rotation of the ATC motor 11 and commands the index position of the tool magazine 31 is included.

When each of these command data is set by the CPU of the operation execution unit 3 and the start flag 41 is set to "1", the motor control unit 5 follows the command data and sets the motors 7, 8,
9, the spindle motor 10 and the ATC motor 11 are started to rotate. At this time, the motor control unit 5 simultaneously starts driving the motor for which the command data is set. For example, if only the Z-axis movement amount command value 46 is set, the Z-axis motor 9 is driven and only the headstock 23 is moved up and down. Also, X-axis movement amount command value 44, Y-axis movement amount command value
If 45 and tool change command value 43 are set, X axis, Y
The axis motors 7 and 8 and the ATC motor 11 are driven, and the table 27
And the tool change are executed in parallel. Then, when all the operations instructed by the command data are completed, the motor control unit 5 sets the end flag 42 to "1" and notifies the operation execution unit 3 of the end of the instructed operation. The operation executing unit 3 receives the end flag 42, updates the execution pointer, generates instruction data of an instruction to be executed next, and sets and updates the instruction data in the motor command buffer unit 4, thereby sequentially executing a series of instructions. The motor control unit 5 is made to execute it.

When setting the command data in the motor command buffer 4 in accordance with the instruction code compiled into the NC language of the operation data buffer unit 2, the operation executing unit 3 normally outputs one instruction code for each instruction code designated by the execution pointer. To set. However, the tool change command (T △△) and table 27
If the positioning command (G00X △△△△ Y △△△△) continues, the command data of the two instructions are written in the motor command buffer section 4 at the same time and the start flag is set to "1". Then, the motor control unit 5 is caused to simultaneously start two operations of the tool exchange operation and the positioning of the table 27.

This is because the Z-axis origin return command (G28Z) is always inserted before the tool exchange command (T △△), and the tool exchange is performed at the position where the headstock 23 is raised near the ascending end. There is no risk that the movement of the table 27 interferes with the movement of the table 27, and two operations are executed in parallel to reduce the non-cutting time.

Even if it is a movement command of the same table 27, a tool change command (T △△) and a cutting feed command of table 27 (G01X △△△△
If Y.DELTA..DELTA..DELTA.) Continues, the parallel operation is not performed.

FIG. 5 is a flow chart showing the processing in the operation execution unit 3 for realizing the above-mentioned control concept.

When the process 100 is started, first, at step 101, it is checked whether or not an operation code buffer unit 2 stores an instruction code group. If the operation data buffer unit 2 is empty, the routine proceeds to step 102, where a part of the program is transferred from the operation data memory unit 1 to the operation data buffer unit 2. In step 103, it is checked whether the instruction code designated by the execution pointer and scheduled to be executed this time out of the instruction code group of the operation data buffer unit 2 is the tool change instruction (TΔΔ). If it is a tool change command, the process proceeds to step 104. In step 104, it is checked whether or not the next command is the positioning command of table 27 (G00XΔΔΔΔYΔΔΔΔ). If it is a positioning command for table 27, step 10
In step 5, the X-axis movement amount command value 44 and the Y-axis movement amount command value 45 of the motor command buffer unit 4 are set to the command values corresponding to the command. If the next command is not a table positioning command, step 105 is not executed and the process proceeds directly to step 106. In step 106, the command value corresponding to the current tool replacement command is set in the tool replacement command value 43 of the motor command buffer unit 4.

On the other hand, in step 103, if the instruction code this time is not the tool change instruction, the process proceeds to step 107. In step 107, it is checked whether or not the command code this time is a spindle command (M03S1000, etc.), and if it is a spindle command, the process proceeds to step 108 and the spindle command 47 of the motor command buffer unit 4 or the spindle speed command value 48. Set the command value corresponding to.

In this way, the command data corresponding to the command code is set in the motor command buffer unit 4 by the processing 200 of steps 103 to 108. At this time, when the tool exchange command and the positioning command of the table 27 are continuous, both command data are set in the motor command buffer unit 4 at the same time.

Next, at step 110, it is checked whether or not the instruction code is a supplementary external input / output instruction such as coolant on / off. No command data is set in the motor command buffer unit 4 with these commands, and the process proceeds from step 110 to step 111, in which a signal is directly output from the operation executing unit 3 to operate the external input / output device 6, and in step 112. Wait for the operation to complete and proceed to step 115. On the other hand, if the instruction is not the external input / output instruction, the process proceeds from step 110 to step 113.

In step 113, the start flag 41 of the motor command buffer unit 4 is set to "1", and the driving of the motors 7 to 11 is started according to the command data set in the process 200 of steps 103 to 108. In step 114, the operation of the motor control unit 5 is completed, and the end flag of the motor command buffer unit 4 is completed.
Wait until 42 becomes "1". If the end flag 42 becomes "1", the flow advances to step 115 to update the execution pointer to specify the next instruction to be executed. And step 10
Return to 1 and repeat the above processing.

In the embodiment described above, when the tool change command and the positioning command of the table 27 exist in succession, the two commands are executed in parallel. This utilizes the fact that the tool changing operation of the ATC device 30 and the moving operation of the table 27 do not interfere with each other due to the structure of the machine shown in FIGS. 2 and 3. Further, in the flow chart shown in FIG. 5, only when the table positioning command comes after the tool change command, it is determined, and in the opposite case, it is not determined. This is because the Z axis origin return command (G28Z) is always inserted before the tool change command in the machine of this embodiment, so the positioning command (G00XΔΔ) is immediately before the tool change command (TΔΔ).
Since ΔΔYΔΔΔΔ) cannot exist, it is omitted. However, the structure of the applied machine tool, especially
Depending on the structure of the ATC device 30, regardless of the order of instructions,
It is desirable and easy to perform a parallel operation when the above two instructions are consecutive.

Further, in the above embodiment, the parallel operation is always performed when the two specific instructions are consecutive, but the operator selects the parallel operation or the sequential operation according to the parameter set from the operation panel 36. It is also possible to enable it.

In the above-described embodiment, the tool change command and the X-axis or Y-axis positioning command are used as the two specific commands that do not interfere with each other even if they are executed at the same time, but the present invention is not limited to this. is not. For example, the spindle rotation command (MΔ
△ S △△) and X-axis or Y-axis positioning command (G00X △△△
△ Y △△△△) or Z axis positioning command (G00Z △
The parallel operation of ΔΔΔ) can be easily realized by performing the same processing in the NC device shown in FIG. To change the rotation speed of the spindle,
It takes about 0.1 to 0.2 seconds, and the non-cutting time can be shortened by moving the table 27 or the like during this time. It seems to be a little in parallel operation for about 0.2 seconds,
In the case of a work piece that frequently uses drilling, tapping, etc., the rotation speed of the spindle is frequently changed, and a considerable reduction in processing time can be expected.

"Effects of the Invention" As described above, the present invention has the above-described configuration, and determines whether or not two specific instructions, whose operations do not interfere even if they are executed simultaneously in a machining program, continuously exist. It is determined based on the combination of two instructions, and the two consecutive instructions are executed in parallel according to the result of the determination, so an instruction that should not be executed in parallel may be executed in parallel, There is an excellent effect that it is possible to surely prevent a problem that an instruction to be executed in parallel is not executed in parallel.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a block diagram of a numerical control device, Fig. 2 is a front view of a machine tool to which the present invention device is applied, Fig. 3 is a side view, and Fig. 4 is a motor. FIG. 5 is a diagram showing the configuration of the command buffer unit, and FIG. 5 is a flowchart showing the processing in the operation executing unit. 2 ... Operation data buffer section, 3 ... Operation execution section, 4 ... Motor command buffer section, 5 ... Motor control section, 7 ... X-axis feed motor, 8 ... Y-axis feed motor, 9 ... Z-axis feed motor, 10
… Spindle motor, 11… ATC motor, 23… Spindle base, 25… Spindle, 27… Table, 30… ATC device, 31… Tool magazine.

Claims (3)

[Claims] 1. A numerical control device for generating a machining program in NC language from machining data inputted such as machining position and machining condition, and sequentially controlling the operation of a machine in accordance with the instructions of the machining program, wherein the machining program includes: A discriminating means for discriminating whether or not there are two specific instructions that do not interfere with each other even if they are executed at the same time, based on the combination of two consecutive instructions, and the consecutive two instructions according to the discrimination result. A numerical control device comprising: means for operating a machine to execute one command in parallel. 2. The numerical controller according to claim 1, wherein the two specific instructions are a tool change instruction and an axis movement instruction that does not interfere with the tool change operation. 3. The numerical controller according to claim 1, wherein the two specific commands are a spindle rotation command and a shaft movement command.