JPH11165238A - Feed rate control method and apparatus in numerical control - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce damage to a collision part which may occur during an NC program test operation. SOLUTION: A test operation end judging section 7 for judging whether an NC program to be executed is a test operation end or not, when it is judged that the test operation is not ended, a feed speed commanded from the NC program is determined in advance. The set upper limit value is changed to a lower value, and when it is determined that the test operation has been completed, the upper limit value is not changed, and the upper limit feed speed changing unit 13 does not change the upper limit value.
A total / range designation discriminator 9 for judging whether to specify an upper limit for all feed speeds commanded from the C program or a range to set an upper limit for a predetermined range; The change unit 13 sets an upper limit value for the entire feed command when it is determined that the entire range is specified, and sets the upper limit value for a feed command within a predetermined range when it is determined that the range is specified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed rate control method and apparatus in numerical control, and more particularly to a feed rate control method and apparatus in numerical control for performing a safe test operation of an NC program.

[0002]

2. Description of the Related Art In a numerically controlled machine tool for processing a workpiece by relatively moving a tool and a workpiece by a feed shaft,
The feed speed of the feed shaft includes a cutting feed speed for processing a workpiece (hereinafter simply referred to as cutting feed) and a rapid feeding speed for positioning (hereinafter simply referred to as fast feeding speed).
The rapid traverse speed is usually set to the maximum speed in order to reduce the processing time. With the speeding up of the machine, the rapid traverse speed is further increased. Even if there is an operator error or NC program mistake, the feed speed at the time of rapid traverse is too fast, and the operator cannot use tools or workpieces of the machine tool. Inevitably colliding with each part, the collision part of the machine tool is more severely damaged than before. For this reason, when performing a test operation using a newly created NC program or an NC program obtained by editing an existing machining program, the operator usually operates the override button to increase the rapid traverse speed of the feed axis to the maximum speed of 25.
The test operation is performed by clamping to a speed of about% so that it can be stopped before a collision in an emergency.

[0003]

However, an operator may perform an erroneous operation such as forgetting to set the override button. At this time, if the collision occurs, the collision portion is damaged. In order to repair the damage at the collision portion, the machine must be stopped for a long period of time or costly.

[0004] Therefore, the present invention solves the above-mentioned problem, so that even if there is a mistake in setting the override button by the operator, N
It is an object of the present invention to provide a feed rate control method and apparatus in numerical control for performing a safe test operation of a C program, thereby reducing damage to a collision portion of a machine tool, and reducing time and cost required for repair.

[0005]

According to the present invention, there is provided a feed rate control method in numerical control according to the present invention, which numerically controls a tool and a workpiece relative to each other by a numerically controlled machine tool in accordance with an NC program to machine the workpiece. In the feed speed control method in
It is determined whether the C program has completed the test operation or has not been completed. If it is determined that the NC program has not been completed the test operation,
The feed rate during the program is regulated so as not to exceed a predetermined upper limit.

Further, in the feed rate control method in the numerical control device according to the present invention, when the NC program is determined to be one in which the test operation has not been completed, the method for regulating the feed rate may include all of the NC programs in the NC program. Or a range designating type that regulates a feed speed within a predetermined range of the NC program so as not to exceed the predetermined upper limit. Is determined, and if it is determined to be in the range designation type, the feed speed only within a predetermined range of the NC program is regulated so as not to exceed the upper limit value.

A feed rate control device in numerical control according to the present invention for solving the above-mentioned problems is a feed rate control device in numerical control for processing a workpiece by relatively moving a tool and a workpiece according to an NC program by a numerically controlled machine tool. Determining means for determining whether an NC program to be executed is a test machining completed or unfinished program, and the determining means determines that the NC program is a test operation not completed. And a feed speed changing means for restricting a feed speed in the NC program from exceeding a predetermined upper limit value.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of an embodiment of a feed rate control device in numerical control according to the present invention. FIG. 1 shows a feed rate control device 1 in numerical control according to the present invention. Although FIG. 1 shows a configuration for one feed shaft for easy understanding, a similar device is provided in an actual apparatus according to the number of feed shafts.

The NC program storage unit 2 stores a recording medium 2a such as a perforated tape, a magnetic tape, or an FD (floppy disk) on which an NC program created by part programming for processing a workpiece based on a part drawing is not shown. This is a storage unit for reading and storing via a reader, and also stores an NC program number set for each NC program.

The NC program editing unit 3 stores the NC program stored in the NC program storage unit 2 in a C (not shown).
While viewing the RT screen, editing is performed by operating a keyboard or mouse (not shown) to create a new NC program, and the created new NC program is stored in the NC program storage unit 2 again. The operation input unit 4 sets and registers a test end flag for identifying an NC program that has completed the test operation and an NC program that has not completed the test operation in accordance with the NC program number stored in the NC program storage unit 2. Input section.

The test operation end registration storage unit 5 is a storage unit for storing the test end flag registered by the operation input unit 4 according to the NC program number stored in the NC program storage unit 2. NC program reading and interpretation unit 6
Reads and interprets a desired NC program for executing machining from the NC program storage unit 2 in which a plurality of NC programs are stored in advance by comparing the NC program number.

The test operation end determining unit 7 determines whether or not the NC program to be executed read by the NC program reading and interpreting unit 6 has completed the test operation with reference to the test operation end registration storage unit 5, The determination result is sent to the whole / range designation determination unit 9. The operation input unit 4 also executes N
The general specification to clamp all the feed speeds described in all the blocks of the C program at a predetermined upper limit, or N
A whole / range designation identification flag is set in accordance with the NC program number stored in the NC program storage unit 2 for identifying whether or not only the feed speed in the block designated in the range within the C program is clamped at the upper limit. It is also an operation input section to register.

The whole / range designation registration storage section 8 stores the whole / range designation identification flag registered by the operation input section 4 as NC.
This is a storage unit that stores according to the NC program number stored in the program storage unit 2. Further, a simple selection signal that can be set by an operator may be provided instead of the whole / range designation registration storage unit 8. In this case, the setting of the whole designation or the range designation is performed irrespective of the NC program number.

When the test operation end determining unit 7 determines that the NC program for executing the information read by the NC program reading / interpreting unit 6 is not the test operation unfinished, the whole / range designation determining unit 9 determines that It is determined whether the feed command of the feed axis in the NC program is specified as a whole or a range by referring to the whole / range designation registration storage unit 8, and the determination result is sent to the upper limit feed speed changing unit 13.

The clamp speed storage unit 12 stores data of the feed speed specified for the entirety or the range, that is, the clamp speed for the rapid feed of the feed axis and the cutting feed set by a manual operation of an operator to perform a so-called override function. Store. As described above, since the fast feed and the cutting feed can be individually set as the respective clamp speeds, the test operation can be performed efficiently.

The feed speed changing unit 13 receives the determination result of the test operation end determination unit 7 and, when it is determined that the running NC program has ended the test operation, the feed speed stored in the NC parameter storage unit 14 in advance. The maximum speeds of the axis rapid traverse and the cutting feed are not changed, and when the NC program is determined to have not been completed in the test operation, the whole / range designation determining unit 9 receives the determination result, and the operating NC If it is determined that the entire program has been designated, N
The data of the maximum speeds of the feed axis rapid traverse and the cutting feed stored in the C parameter storage unit 14 are changed to the data of the respective clamp speeds for the rapid axis traverse and the cutting feed of the feed axis stored in the clamp speed storage unit 12, and the operation is performed. When it is determined that the NC program in the range has been designated, the data of the maximum speed of the feed axis and the maximum speed of the cutting feed is stored only in the program range. Change to speed data.

The feed speed changing unit 13 receives the determination result of the test operation end determination unit 7 irrespective of the determination result of the whole / range designation determination unit 9, and determines whether the NC program in operation is the test operation not completed. When it is determined that the maximum speed of the feed axis and the maximum speed of the cutting feed stored in advance in the NC parameter storage unit 14, the data is stored in the clamp speed storage unit 1.
2 may be changed to the data of the respective clamp speeds for the rapid feed and the cutting feed of the feed axis stored in 2.

The NC parameter storage unit 14 stores the feed rate control device 1 in the numerical control shown in FIG.
Stores the data of the maximum speed of the feed axis rapid traverse and cutting feed. The interpolation distribution speed control unit 10 reads a movement command and a speed command in accordance with a block in the NC program to be executed read by the NC program reading / interpreting unit 6 and reads the movement command and the speed command. Interpolation and distribution are performed based on the stored data of the maximum speeds of the feed axis rapid traverse and cutting feed, and a movement distribution command is sent to the servo control unit 11 at a predetermined cycle, for example, every 8 ms.

The servo control unit 11 drives a servo motor 15 connected to the feed shaft in accordance with the movement distribution command sent from the interpolation distribution speed control unit 10. The feed rate control device 1 in the numerical control of the present invention determines whether the upper limit of the feed rate is changed for the entire NC program when the NC program is determined to have not been completed in the test operation, or for a predetermined range. And the feed speed is clamped below the clamp speed for the rapid feed and the cutting feed of the feed shaft stored in the clamp speed storage unit 12 accordingly. Only when damage can occur, the upper limit of the feed speed can be changed by specifying the range to perform safe operation, and thus the efficiency of test operation can be improved.

Next, the operation of the feed rate control device shown in FIG. 1 when the NC program is executed will be described below. FIG. 2 is a flowchart showing the procedure of the feed speed control according to the present invention. The flowchart of FIG. 2 will be described with reference to FIG. In FIG. 2, the number following S indicates a step number. First, in step S1, it is determined whether or not the NC program to be executed is the one for which the test operation has not been completed. The test operation end registration storage unit 5 set in correspondence with the NC program number stored in the NC program storage unit 2 Is determined based on the test end flag stored in the
If S, the process proceeds to step S2, and if NO, the process proceeds to step S4.

In step S2, the NC program stored in the NC program storage unit 2 determines whether the target of the feed rate clamping in the NC program is the entire specification specified in the entire NC program or the range specified in a predetermined range. The determination is made based on the whole / range designation identification flag stored in the whole / range designation registration storage unit 8 registered corresponding to the program number. When the result of the determination is the whole designation, the process proceeds to step S3, and when the range is designated, Goes to step S11.

In step S 3, the parameters that define the upper limit of the feed speed stored in the NC parameter storage unit 14, ie, the data of the maximum speed of the feed axis rapid traverse and the cutting feed, are stored in the clamp speed storage unit 12. Rewrite with the data of each clamp speed for the feed axis rapid traverse and cutting feed. In step S4, the NC program is read and executed in block order. Next, in step S5, it is determined whether or not the block command executed in step S4 is M30 (program end rewind). If the determination result is YES, the process proceeds to step S6, and if NO, the process proceeds to step S8.

In step S6, the parameters rewritten in step S3 are returned to the original data, that is, the data of the maximum speed of each of the rapid feed and the cutting feed of the feed axis stored in the NC parameter storage unit 14. Next, in step S7, a test operation end flag of the executed NC program is set, and the flag is stored in the test operation end registration storage unit 5 according to the NC program number. In step S8,
The next block is read and the process proceeds to step S4.

If it is determined in step S2 that the range has been designated, the flow advances to step S11.
Read and execute the program in block order. Next, in step S12, it is determined whether or not the block command read in step S11 is a code indicating the start of range specification, for example, a code specified in advance such as M100, and if the determination result is YES, the process proceeds to step S13, where NC The parameter that defines the upper limit of the feed rate stored in the parameter storage unit 14, that is, the data of the maximum speed of the feed axis rapid traverse and the cutting feed, is stored in the clamp speed storage unit 12 for the rapid traverse and the cutting feed of the feed axis. The data is rewritten to each clamp speed data, and if the above determination result is NO, the process proceeds to step S14.

In step S14, it is determined whether or not the block command read in step S11 is a code indicating the end of range specification, for example, a code specified in advance such as M200. If the determination result is YES, the process proceeds to step S15. If NO, the process proceeds to step S16. Step S1
In step 5, the parameters rewritten in step S13 are returned to the original data, that is, the data of the maximum speeds of the feed axis rapid feed and cutting feed stored in the NC parameter storage unit 14.

In step S16, it is determined whether or not the block command executed in step S11 is M30 (program end rewind). If the determination result is YES, the process proceeds to step S6, and if NO, the process proceeds to step S17. . In step S17, the next block is read, and the process proceeds to step S11. Next, the feed speed control of the present invention will be described using a working example of a workpiece.

FIG. 3 is a diagram showing an example of machining a work, and FIG. 4 is a diagram showing an example of a machining program for machining a work as shown in FIG. Each row in FIG. 4 corresponds to each block command. First, the feed speed control device 1 starts reading and interpreting the NC program number 0005. At T01, the first tool is mounted, and at G91 G28 Z0.0, the origin is returned to the Z axis (spindle), and G91 G28 X0.0
At Y0.0, the origin return of the X axis and the Y axis is performed. M06 T
At 02, the tool is changed from the first tool to the second tool. S
8000 M03 with main shaft rotated clockwise 8000 RPM
Rotate with. The coolant is supplied in M08.

M100 indicates the start of the upper limit clamping of the feed rate. G90 G54G00 X55.0
At Y-45.0, the feed is clamped at the upper limit clamp speed from the origin (X, Y) = (0, 0) to the point b (X, Y) = (55.0, −45.0) and fast-forwarded. Then, Z100.0
Moves the Z axis by 100 mm, and Z2 moves the Z axis by 2 mm.
X13.0 Move to point c (113.0, 8.0) at Y8.0.

M200 indicates the end of the designation of the upper limit clamp of the feed rate. G01 Z-12.0 F4000
Feed at a cutting feed speed of 4000 mm / min from which the upper limit clamp speed of the cutting feed speed is released. The Y axis is d at Y-93.0.
Move to point (113.0, -93.0), move the X axis to point e (-3.0, -93.0) at X-3.0, and move to Y3.
At 0, the Y axis is moved to the point f (−3.0, 3.0), and X11
At 8.0, the X axis is moved to point g (118.0, 3.0).

Next, the Z axis is set to 1 by G00 Z100.0.
The feed is fast-forwarded to the position of 00 mm, the X-axis and the Y-axis are returned to the origins at X0.0Y0.0M05, and the main spindle is stopped. The coolant is stopped at M09, and the NC program is returned to the start position at M30. End the NC program with%. In the embodiment described above, each feed axis (X, Y, Z) of the three-axis orthogonal coordinate system has been described as an example, but the present invention is not limited to this, and the rotary feed axes (A,
It goes without saying that the same applies to B and C).

[0031]

As described above, according to the present invention,
The end / non-end of the test operation is automatically determined, the feed speed is automatically clamped, and the test operation of the NC program can be safely performed. Machine tool damage can be minimized,
Reduce the time and cost of repairing damage. Also NC
There is also an effect that the redundant check of the program security is not wasted.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a feed rate control device in numerical control according to the present invention.

FIG. 2 is a flowchart showing a procedure of feed speed control according to the present invention.

FIG. 3 is a diagram illustrating a processing example of a work;

FIG. 4 is an example of an NC program for processing the work shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Feed speed control device 2 ... NC program storage part 3 ... NC program editing part 4 ... Operation input part 5 ... Test operation end registration storage part 6 ... NC program reading and interpretation part 7 ... Test operation end discrimination part 8 ... Whole / range Designation registration storage unit 9 ... Overall / range designation determination unit 10 ... Interpolation distribution speed control unit 11 ... Servo control unit 12 ... Clamp speed storage unit 13 ... Upper limit feed speed change unit 14 ... Parameter storage unit 15 ... Servo motor

Claims (3)

[Claims] 1. A feed rate control method in a numerical control for processing a workpiece by relatively moving a tool and a workpiece according to an NC program by a numerically controlled machine tool, wherein the NC program to be executed has completed a test operation. It is determined whether the NC program is not completed or not. When it is determined that the NC program is not completed in the test operation, the feed rate in the NC program is regulated so as not to exceed a predetermined upper limit. A feed speed control method in numerical control, characterized in that: 2. When it is determined that the NC program is not completed in the test operation, the method of controlling the feed speed does not exceed all the feed speeds in the NC program by the predetermined upper limit value. It is determined whether the form is an entire designated form that restricts the feed rate or a range designated form that regulates a feed rate within a predetermined range of the NC program so as not to exceed the predetermined upper limit value. 2. The feed rate control method according to claim 1, wherein when it is determined that the feed rate within a predetermined range of the NC program does not exceed the upper limit value. 3. A feed rate control device in numerical control for processing a workpiece by relatively moving a tool and a workpiece according to an NC program by a numerically controlled machine tool, wherein the NC program to be executed is one in which test machining has been completed. Discriminating means for discriminating whether or not the NC program is not yet completed in the test operation. If the discriminating means determines that the NC program is not completed in the test operation, the feed rate in the NC program is a predetermined upper limit value. And a feed speed changing means for restricting the feed speed so as not to exceed.