JP2011237885A - Numerical control apparatus with function of tip r correction or tool diameter correction in control by tabular data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a numerical control apparatus with function of tip R correction or tool diameter correction by tabular data, in which correction of tabular data can be made unnecessary only by changing tip R correction amount or tool diameter correction amount, even if the tip of a bite tool or the like or the diameter of an end mill and the like is changed in operation by tabular data.SOLUTION: It is determined whether tip R correction or tool diameter correction is commanded or not. If it is commanded, the process proceeds to a step SA20, or otherwise the process proceeds to a step SA50 (SA10), startup of the tip R correction or tool diameter correction is executed (SA20), and main processing of the tip R correction or tool diameter correction is executed (SA30). Then, it is determined whether change or cancel of correction direction is executed or not. If cancel is executed, the process returns to the step SA10 to continue the processing, or otherwise the process returns to the step SA30 to continue the processing (SA40), the cancel processing of the tip R correction or tool diameter correction is executed (SA50), and the processing is ended.

Description

  The present invention relates to a numerical control device for controlling machine tools and industrial machines, and in particular, a path using table format data (pass table operation data) in which each axis of a machine controlled by the numerical control device operates synchronously. The present invention relates to a numerical control device that performs table operation.

  In operation using table format data, for example, all the axes operate in synchronism with time by designating the time passing through each point of the program path using table format data (path table operation data). In this way, table format data in which the position of the axis (movable axis) based on time, axis position, or spindle position is stored in the memory, and each axis is driven while sequentially reading the table format data. A numerical control device having a function (pass table operation function) is a known technique as disclosed in Patent Literature 1 and Patent Literature 2. The pass table operation function enables free tool operation that is not constrained by conventional machining programs, and shortens machining time and increases machining accuracy.

JP 59-177604 A JP 2003-303005 A

  As explained in the background art, in the conventional operation using the table format data (pass table operation), the time to pass through each point of the program route is specified by the table format data (path table operation data). Works in sync with time.

  However, for the operation by the table format data (pass table operation), the radius value of the tool such as the cutting edge R correction for correcting the error caused by the roundness of the cutting edge of the cutting tool or the like in the operation by the NC program, and the tool such as the end mill tool. When the tool radius correction for correcting the above is performed, the program path, the cutting edge R center path, and the tool center path are different, and therefore, a synchronization deviation from the designated time occurs in the axis on which these corrections are performed. For this reason, in the conventional table format data operation (pass table operation), every time the diameter of a cutting tool such as a bite tool or the diameter of an end mill tool changes, the error amount (change in diameter) is taken into account to change the table format data. There was a need to fix.

  Here, an example of operation (pass table operation) using conventional table format data will be described with reference to FIGS. 36 and 37. FIG. 36 is a diagram for explaining an example of a pass table operation according to the prior art before tool replacement. Moreover, FIG. 37 is a figure explaining the example of the pass table driving | operation based on the prior art after tool replacement | exchange.

  In accordance with the table format data (pass table operation data) shown in FIG. 36 (b), as shown in FIG. 36 (a), the tool 2 processes the workpiece 4 along the program path of the pass table, and forms the processed shape. 6 is generated. The tool 2 used at this time is a bite tool or the like, and its radius is 2.0 mm.

  FIG. 37A illustrates that the workpiece 4 is machined by replacing the tool 2 having a radius of 2.0 mm shown in FIG. 36 with the tool 3 having a radius of 3.0 mm. In addition, in order to generate the machining shape 6 on the workpiece 4 as in FIG. 36A, as shown in FIG. 37B, the program path of the table format data (pass table operation data) accompanying the tool change. Need to be changed.

  As described above, in the conventional table format data operation (pass table operation), the cutting edge R correction for correcting the error due to the roundness of the cutting edge of the cutting tool or the like, and the radius value of the tool such as the end mill tool are corrected. Since the tool radius correction could not be performed, it is necessary to correct the table format data (pass table operation data) in consideration of the error every time the cutting edge of a bite tool or the diameter of an end mill tool changes. It took time and was a problem.

  Therefore, an object of the present invention is to change only the cutting edge R correction amount and the tool diameter correction amount even when the diameter of the cutting edge of a tool such as a bite tool or the diameter of an end mill tool changes in operation based on table format data (pass table operation data). Another object of the present invention is to provide a numerical control device having a function of correcting the cutting edge R or correcting the tool radius in the control with table format data that can eliminate the need for correction of the table format data.

  The invention according to claim 1 of the present application is based on the time, the axis position, or the spindle position, the reference time, the axis or spindle position, and the axis or spindle position different from the reference axis or spindle. Is stored in a memory, and the reference time, the position of the axis or spindle, and the position of an axis or spindle different from the reference axis or spindle are sequentially read, In a numerical control device that controls the position of another axis or spindle in synchronization with the reference time, the position of the axis or spindle, and the position of the other axis or spindle in synchronization with the position of the axis or spindle, the cutting edge R correction amount or the tool diameter Storage means for storing the correction amount, command means for instructing valid / invalid of the cutting edge R correction or tool radius correction to the table format data, the table format data and the cutting edge R correction amount Or a correction amount calculating means for calculating a correction amount of the position of the other axis or spindle to be corrected with respect to the block of the table format data as the tool advances, and the correction amount calculating means. The calculation means for calculating the position of the another axis or spindle from the correction amount calculated by the above, the reference time, the position of the axis or spindle generated by performing the cutting edge R correction or the tool radius correction, Output means for outputting the position of the other axis or the main axis in which the synchronization deviation of the position of the main axis or the main axis is corrected, and the function of the cutting edge R correction or the tool diameter correction in the control based on the table format data Is a numerical control device.

The invention according to claim 2 is characterized in that the output means prefetches the table format data and acquires the change point of the tool traveling direction, and the tool is obtained from the change point of the tool traveling direction acquired by the acquisition means. When the tool turns inside the workpiece as a result of the determination by the determination unit that determines whether the workpiece is turned inside or outside, the synchronization deviation is caused by the change in the tool direction in the corrected tool path. When the tool stops until it is eliminated, and the tool goes outside the workpiece, an addition means for adding a constant movement pulse to the movement amount by the program until the synchronization deviation is eliminated in the section where movement is not on the program path The numerical control device having a function of correcting the cutting edge R or correcting the tool radius in the control based on the table format data according to claim 1.
The invention according to claim 3 further includes alarm means for determining whether or not the value of the addition result obtained by the adding means exceeds a set limit value and making an alarm when the value exceeds the limit value. A numerical control device having a function of correcting the cutting edge R or correcting the tool radius in the control using the table format data according to claim 2.

  According to the present invention, in operation based on table format data (pass table operation data), even if the diameter of a cutting edge such as a bite tool or an end mill tool changes, the table format is simply changed by changing the cutting edge R correction amount or the tool diameter correction amount. It is possible to provide a numerical control device having a function of correcting the cutting edge R or correcting the tool radius in the control based on table format data that can make correction of data unnecessary.

It is a schematic diagram of the operation function by the table format data which embodiment of this invention performs. It is a figure explaining the example of the pass table driving | operation (before tool change) which concerns on this invention. It is a figure explaining the example of the pass table driving | operation (after tool change) which concerns on this invention. It is a figure showing the cutting edge R center path and the program path of the cutting edge R center point of the tool when the G42 command (correction to the right of the moving direction of the tool) is performed at the starting point (the moving direction of the tool is changed from a straight line to a straight line) If changed).

It is a figure showing the cutting edge R center path and the program path of the cutting edge R center point of the tool when the G42 command (correction to the right of the moving direction of the tool) is performed at the starting point (the moving direction of the tool changes from a straight line to an arc) If changed). It is a figure explaining the table format data (path table operation data) containing a blade edge | tip R correction | amendment or a tool diameter correction | amendment command. 7 is a table showing the tool position when the cutting edge R correction amount or the tool radius correction amount is r in the program path of FIG. 6. FIG. 8 is a diagram for explaining the relationship between the program path and the tool position when the cutting edge R correction amount or the tool radius correction amount is r, shown in FIGS. 6 and 7. It is a figure explaining the cutting edge R center path | route of a tool when a G40 instruction | command is performed, and a program path | route (when the advancing direction of a tool is changed from a straight line to a straight line). It is a figure explaining the cutting edge R center path | route of a tool when a G40 command is performed, and a program path | route (when the advancing direction of a tool is changed from a circular arc to a straight line). It is a table | surface showing an example of a program path | route when the cutting edge R correction amount or tool radius correction amount is set to r. 12 is a table showing tool positions when the cutting edge R correction amount or the tool radius correction amount is r in the program path of FIG. 11. It is a figure explaining the relationship between a program path | route and a tool position when the cutting edge R correction amount or tool radius correction amount is set to r shown by FIG. 11 and FIG. It is a figure explaining the case where the advancing direction of a tool changes during a blade edge | tip R correction | amendment or tool warp correction, and a tool turns inside a workpiece | work, Comprising: The advancing direction of a tool is changed from a straight line to a straight line. It is a figure explaining the case where the advancing direction of a tool changes during cutting edge R correction | amendment or tool warp correction, and a tool turns inside a workpiece | work, Comprising: When the advancing direction of a tool is changed from a straight line to a circular arc. It is a figure explaining the case where the advancing direction of a tool changes during a blade edge | tip R correction | amendment or tool warp correction, and a tool turns inside a workpiece | work, Comprising: The advancing direction of a tool is changed from a circular arc to a straight line. It is a figure explaining the case where the advancing direction of a tool changes during a blade edge | tip R correction | amendment or tool warp correction, and a tool rotates inside a workpiece | work, Comprising: The advancing direction of a tool is changed from a circular arc to a circular arc. It is a figure explaining table format data (path table) including a cutting edge R correction or a tool diameter correction command when a tool turns inside a work. In the table number 2000 shown in FIG. 18, it is a table | surface showing an example of a tool position when the cutting edge R correction amount or tool diameter correction amount is set to r. FIG. 20 is a diagram for explaining a program path and a tool position when the cutting edge R correction amount or the tool radius correction amount is set to r shown in FIGS. 18 and 19. It is a figure explaining what kind of path | route the blade edge | tip R passes when the advancing direction of a program path | route changes from a straight line to a straight line. It is a figure explaining what kind of path | route the blade edge | tip R passes when the advancing direction of a program path | route changes from a straight line to a circular arc. It is a figure explaining what kind of path | route the blade edge | tip R passes when the advancing direction of a program path | route changes from a circular arc to a straight line. It is a figure explaining what kind of path | route the blade edge | tip R passes when the advancing direction of a program path | route changes from a circular arc to a circular arc. It is a table | surface showing an example of a program path | route when it is assumed that the cutting edge R correction amount or the tool diameter correction amount is r, and the synchronization deviation is eliminated between L5 and L6. It is a table | surface showing an example of a tool position, with the cutting edge R correction amount or the tool radius correction amount being r. FIG. 27 is a diagram for explaining the relationship between the program path and the tool position when it is assumed that the cutting edge R correction amount or the tool diameter correction amount is r and the synchronization deviation between L5 and L6 is eliminated, as shown in FIGS. . It is a flowchart explaining the algorithm which performs the cutting edge R correction | amendment or tool diameter correction | amendment which concerns on this invention. It is a flowchart explaining the algorithm of the startup process which performs the blade edge | tip R correction | amendment or tool diameter correction | amendment which concerns on this invention. It is a flowchart explaining the algorithm of the main process which performs the blade edge | tip R correction | amendment or tool diameter correction | amendment which concerns on this invention. It is a flowchart explaining the algorithm of the cancellation process of the cutting edge R correction | amendment or tool diameter correction | amendment which concerns on this invention. It is a figure explaining the means to calculate the correction amount of each axis concerning the present invention. It is a figure explaining the means to calculate the intersection S of the center path | route of the blade edge | tip R correction | amendment or tool diameter correction | amendment which concerns on this invention. It is a figure explaining the means to calculate the start point and end point of the area which does the movement which does not exist in the program route based on this invention. It is a principal part block diagram of the numerical control apparatus of one Embodiment of this invention. It is a figure explaining the example of the pass table driving | operation (before tool change) which concerns on a prior art. It is a figure explaining the example of the pass table driving | operation (after tool change) which concerns on a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is demonstrated about the structure same as description of a prior art, or a similar structure.
FIG. 1 is a schematic diagram of an operation function based on table format data executed by the embodiment of the present invention. In the embodiment of the present invention, the algorithm processing described with reference to FIGS. 28, 29, 30, and 31 described later is executed in the schematic diagram of FIG.
In the following, for the sake of explanation, it is assumed that the plane to be corrected is an XY plane, but the present invention can be similarly applied to a plane other than the XY plane and a three-dimensional space.

  An X-axis path table Tx and a Y-axis path table Ty are provided. The X-axis path table Tx stores the X-axis position with respect to the reference position. The Y-axis path table Ty stores the Y-axis position with respect to the reference position. A pulse from the position coder attached to the main shaft (main shaft position), a pulse from the position coder attached to the shaft (axis position), or a pulse based on the time from the external pulse generator as a reference is input to the counter 101. Input and count. Hereinafter, for simplification, the axis position is omitted.

  The count value of the counter 101 is multiplied by the override value set in the override means by the multiplier 102 and stored in the reference position counter 103. The reference position counter 103 is reset when the path table operation function is commanded. The value of the reference position counter 103 is input as a reference position to the X-axis and Y-axis path table interpolation processing units 104x and 104z. In the X-axis and Y-axis path table interpolation processing units 104x and 104y with the value of the reference position counter 103 as the reference position, the X-axis and Y-axis commands with respect to the reference position are referenced with reference to the X-axis path table Tx and Y-axis path table Ty. The position is obtained, the movement amount in the processing cycle is obtained, and the movement amount is output to the adders 106x and 106y as a command.

  The value of the reference position counter 103 is further input to the cutting edge R correction or tool radius interpolation processing units 107xt and 107yt. The cutting edge R correction or tool diameter interpolation processing units 107xt and 107yt refer to the cutting edge R correction or tool diameter correction table Tt for each processing cycle, and interpolate the correction amount related to the cutting edge R correction or tool diameter correction to obtain the interpolation correction amount. Output to the adders 106x and 106y, respectively. By outputting the value obtained as a result of the addition by the adders 106x and 106y to the control shaft motors 105x and 105y, the X and Y axes can be synchronized with the reference position.

  According to the present invention, in operation based on table format data (pass table operation data), even if the diameter of a cutting edge such as a bite tool or an end mill tool changes, the table format is simply changed by changing the cutting edge R correction amount or the tool diameter correction amount. Data correction is unnecessary. In order to solve the problems in the prior art, in the present invention, means for controlling the traveling speed of the tool so that the time passing through the point where the outer periphery of the tool contacts the machining surface coincides with the time programmed by the table format data. Is provided.

  FIG. 2 is a diagram for explaining an example of the pass table operation (before tool change) according to the present invention. FIG. 3 is a diagram for explaining an example of the pass table operation (after tool change) according to the present invention. In accordance with the table format data (pass table operation data) shown in FIG. 2B, as shown in FIG. 2A, the tool 2 processes the workpiece 4 along the program path of the pass table operation data, A machining shape 6 is generated. The tool 2 used at this time is a bite tool or the like, and its radius is 2.0 mm. As shown in FIG. 2A, in the present invention, the machining shape 6 and the program path set by the path table operation data match.

FIG. 3A illustrates that the workpiece 4 is machined by replacing the tool 2 having a radius of 2.0 mm shown in FIG. 2A with the tool 3 having a radius of 3.0 mm. FIG. 3B shows table format data (pass table operation data) used for generating the machining shape 6 on the workpiece 4 as in FIG. 2B. It can be understood by comparing the table format data (pass table operation data) shown in FIG. 2 (b) with the table format data (pass table operation data) shown in FIG. 3 (b). Even if is changed, the same machining shape 6 can be generated for the workpiece 4 without changing the table format data (pass table operation data).
As table format data, there are three types of tables, the X-axis path table Tx, the Y-axis path table Ty, the blade edge R correction or the tool radius correction Tt, which are operated in parallel. In the following, they are collectively expressed in one table as shown in FIG. 2 (b) and FIG. 3 (b).

<Startup process>
Next, start-up processing, which is processing when commanding the validity of cutting edge R correction or tool radius correction in the path table operation according to the present invention, will be described.
In the embodiment of the present invention, in the cutting edge R correction or the tool radius correction, the following commands can be given as an example.
・ G42 command: Command to correct to the right of the tool traveling direction
・ G41 command: Command to correct to the left in the direction of tool movement
・ G40 command: Command to cancel cutting edge R correction or tool radius command
These commands are known commands possessed by a numerical controller that controls the machine tool.
The startup process is also executed when the G42 command and the G41 command are switched. The operation when the G40 command is issued from the state in which the G42 command or the G41 command is valid will be described later as <Cancel processing>.
When the cutting edge R correction or the tool radius correction is invalid and the block for instructing the validity of the cutting edge R correction or the tool radius correction is executed, the cutting edge R correction or the tool is executed immediately before the next change of the tool traveling direction. Correction is performed at a constant speed so that the diameter correction is completed. Here, the block means a section from one reference value to the next reference value.

4 and 5 are diagrams showing the cutting edge R center path and the program path of the cutting edge R center point of the tool when the G42 command (correction to the right in the tool traveling direction) is performed at the starting point. Note that the tool center path of the tool is the same as that of the tool edge R center path, and therefore, the blade edge R center path will be described below as an example.

  FIG. 4 shows a case where the traveling direction of the tool is changed from a straight line to a straight line. When the cutting edge R correction is not performed, the cutting edge R center point 8 processes the workpiece 4 through a program path indicated by a solid arrow. In this case, a processing error occurs. On the other hand, when the cutting edge R correction according to the present invention is performed according to the G42 command, the cutting edge R center point 8 processes the workpiece 4 through the cutting edge R center path indicated by the broken-line arrow. The cutting edge R correction by the G42 command is completed when the cutting edge R center point 8 reaches a point S where the traveling direction of the tool changes.

  FIG. 5 illustrates a case where the traveling direction of the tool is changed from a straight line to an arc. When the cutting edge R correction is not performed, the cutting edge R center point 8 processes the workpiece 4 through a program path indicated by a solid arrow. On the other hand, when the cutting edge R correction according to the present invention is performed according to the G42 command, the cutting edge R center point 8 processes the workpiece 4 through the cutting edge R center path indicated by the broken-line arrow. The cutting edge R correction by the G42 command is completed when the cutting edge R center point 8 reaches a point S where the traveling direction of the tool changes.

  Next, the relationship between the program path and the tool position when the cutting edge R correction amount is r will be described with reference to FIGS. 6, 7, and 8. The same explanation can be made when the tool radius correction amount is r.

FIG. 6 is a diagram for explaining table format data (pass table operation data) including a cutting edge R correction or a tool radius correction command.
The path table number 1000 includes an X-axis program path and a Y-axis program for each block (L0, L1, L2, L3, L4, L5, L6, L7, L8) of time (time) or spindle position. The path and the cutting edge R correction or the tool radius correction command are set. After the G42 command at L0, the time (main shaft position) at which the traveling direction changes next is the point L5 shown in FIG. In FIG. 6, the notation (G42) means that each block of L1 to L8 is instructed as a modal information as a G42 command, although it is not a G42 command block.

  FIG. 7 is a table showing the cutting edge R center path of the cutting edge R center point that is the position of the tool when the cutting edge R correction amount is r in the program path of FIG. Here, the cutting edge R correction amount will be described as an example. FIG. 8 is a diagram for explaining the relationship between the program path and the cutting edge R center path when r is the cutting edge R correction amount shown in FIGS. 6 and 7. In FIG. 6, since the G42 command which is the cutting edge R command is set in the block L0 and the blocks L1 to L8 have the G42 command as modal information, when the cutting edge R correction amount is r, in each block When correction is performed, the position of the Y axis of the tool is corrected. In this example, the intersection S (see FIG. 8) at which the traveling direction of the tool changes is a point at which L5 changes in the traveling direction of the tool.

<Main processing for cutting edge R correction or tool radius correction>
Next, main processing of cutting edge R correction or tool radius correction in the path table operation according to the present invention will be described. There are two cases where the traveling direction of the tool changes during the cutting edge R correction or the tool diameter correction, when the tool rotates inside the workpiece and when the tool rotates outside the workpiece.
Hereinafter, each case will be described. 14-20 is a figure explaining the case where a tool turns the inner side of a workpiece | work. Moreover, FIGS. 21-27 is a figure explaining the case where a tool rotates the outer side of a workpiece | work.

(When the tool turns inside the workpiece)
This corresponds to the case where the workpiece side angle at the intersection of the program paths exceeds 180 degrees. In this case, since the tool movement path is shorter than the program path, the tool temporarily stops at the intersection of the cutting edge R center path (the point S where the traveling direction of the tool changes) in order to eliminate the synchronization shift. The tool starts to synchronize at the moment when the synchronization deviation of the tool position is eliminated with respect to the reference time, the axis or the position of the spindle. This makes it possible to synchronize the reference time, the position of the shaft or the spindle, the outer periphery of the tool and the contact position of the workpiece.

  FIG. 14 is a diagram for explaining a case where the advancing direction of the tool changes during the cutting edge R correction and the tool turns inside the workpiece, and the advancing direction of the tool is changed from a straight line to a straight line. The workpiece 4 is machined while moving the cutting edge R center of the tool corrected for the cutting edge R along the path of the cutting edge R center as shown in the figure. Since the cutting edge R center path, which is the movement path of the tool, is shorter by the dotted line section of the program path than the program path, the tool temporarily stops at the intersection S of the cutting edge R center path in order to eliminate the synchronization deviation. The tool starts to synchronize at the moment when the synchronization deviation of the tool position is eliminated with respect to the reference time, the axis or the position of the spindle. This makes it possible to synchronize the reference time, the position of the shaft or the spindle, the outer periphery of the tool and the contact position of the workpiece. The time to stop is a section between the intersection point of the perpendicular line and the program path, and a perpendicular line is drawn from the intersection point S to the program path. This interval can be calculated mathematically.

  FIG. 15 is a diagram for explaining a case where the advancing direction of the tool changes during the cutting edge R correction and the tool turns inside the workpiece, and the advancing direction of the tool is changed from a straight line to an arc. The workpiece 4 is machined while moving the cutting edge R center of the tool corrected for the cutting edge R along the path of the cutting edge R center as shown in the figure. Since the cutting edge R center path, which is the movement path of the tool, is shorter by the dotted line section of the program path than the program path, the tool temporarily stops at the intersection S of the cutting edge R center path in order to eliminate the synchronization deviation. The tool starts to synchronize at the moment when the synchronization deviation of the tool position is eliminated with respect to the reference time, the axis or the position of the spindle. This makes it possible to synchronize the reference time, the position of the shaft or the spindle, the outer periphery of the tool and the contact position of the workpiece.

FIG. 16 is a diagram illustrating a case where the traveling direction of the tool changes during the cutting edge R correction and the tool rotates inside the workpiece, and the traveling direction of the tool is changed from an arc to a straight line.
The workpiece 4 is machined while moving the cutting edge R center of the tool corrected for the cutting edge R along the path of the cutting edge R center as shown in the figure. Since the cutting edge R center path, which is the movement path of the tool, is shorter by the dotted line section of the program path than the program path, the tool temporarily stops at the intersection S of the cutting edge R center path in order to eliminate the synchronization deviation. The tool starts to synchronize at the moment when the synchronization deviation of the tool position is eliminated with respect to the reference time, the axis or the position of the spindle. This makes it possible to synchronize the reference time, the position of the shaft or the spindle, the outer periphery of the tool and the contact position of the workpiece.

FIG. 17 is a diagram for explaining a case where the advancing direction of the tool changes during the cutting edge R correction and the tool turns inside the workpiece, and the advancing direction of the tool is changed from an arc to an arc.
The workpiece 4 is machined while moving the cutting edge R center of the tool corrected for the cutting edge R along the path of the cutting edge R center as shown in the figure. Since the cutting edge R center path, which is the movement path of the tool, is shorter by the dotted line section of the program path than the program path, the tool temporarily stops at the intersection S of the cutting edge R center path in order to eliminate the synchronization deviation. The tool starts to synchronize at the moment when the synchronization deviation of the tool position is eliminated with respect to the reference time, the axis or the position of the spindle. This makes it possible to synchronize the reference time, the position of the shaft or the spindle, the outer periphery of the tool and the contact position of the workpiece.

  FIG. 18 is a diagram for explaining table format data (path table operation data) including a cutting edge R correction or a tool radius correction command when the tool turns inside the workpiece. The path table number 2000 is the X-axis program path, Y-axis program path, and cutting edge R correction for each block of time or spindle position (L0, L1, L2, L3, L4, L5, L6). Tool radius compensation command is set. A G42 command is set as modal information in the blocks L0 to L6. A block L3 is a change point of the traveling direction of the tool.

  FIG. 19 is a table showing an example of the tool position when the cutting edge R correction amount or the tool radius correction amount is r in the table number 2000 shown in FIG. FIG. 20 is a diagram for explaining the program path and tool position when the cutting edge R correction amount is r, as shown in FIGS. 18 and 19. In this case, since the tool movement path (cutting edge R center path) is shorter than the program path in the section of L2 → L3 → L4, the intersection of the cutting edge R center path (progress of the tool) is eliminated in order to eliminate the synchronization shift. The tool stops once at point S) where the direction changes.

(When the tool turns outside the workpiece)
Next, a case where the tool turns outside the workpiece will be described.
The case where the tool turns outside the workpiece corresponds to the case where the angle on the workpiece side at the intersection of the program paths is 180 degrees or less. FIGS. 21 to 27 are diagrams for explaining what route the cutting edge R center follows when the traveling direction of the program route changes.

  When the traveling direction of the program path changes, it is necessary to move without command to the program. This moving section is shown as a section of only a dotted line in FIGS. In the section of only the dotted line, the tool is moved by outputting a movement pulse having a constant value for each control cycle. However, since the reference time, the position of the axis or the spindle continues to advance during this time, the tool position is synchronized with the reference time, the position of the axis or the spindle when the movement of only the dotted line is completed. Deviation has occurred. In order to eliminate this synchronization deviation, a movement pulse having a constant value is added to the movement pulse by the program command until the synchronization deviation is eliminated after the section of only the dotted line is completed.

The moving pulse having a constant value can be set by a parameter, and can also be set by executing a program command as follows simultaneously with the G41 command or the G42 command. The fixed value can be set to an arbitrary value.
L0G42P8: (Correction is performed by 8 at the minimum setting unit for each control cycle of the numerical controller)

  FIG. 21 is a diagram for explaining what path the center of the cutting edge R passes when the traveling direction of the program path changes from a straight line to a straight line when the tool rotates outside the workpiece. In the dotted line section with only a dotted line, the tool moves with the output of a fixed value movement pulse, and in the overlapping section where the broken line and dotted line overlap, the correction delay is added to the fixed value movement pulse to recover the delay and eliminate the synchronization error. To do.

  FIG. 22 is a diagram for explaining what path the cutting edge R center passes when the traveling direction of the program path changes from a straight line to an arc. In the dotted line section with only a dotted line, the tool moves with the output of a fixed value movement pulse, and in the overlapping section where the broken line and dotted line overlap, the correction delay is added to the fixed value movement pulse to recover the delay and eliminate the synchronization error. To do.

  FIG. 23 is a diagram for explaining what path the cutting edge R center passes when the traveling direction of the program path changes from an arc to a straight line. In the dotted line section with only a dotted line, the tool moves with the output of a fixed value movement pulse, and in the overlapping section where the broken line and dotted line overlap, the correction delay is added to the fixed value movement pulse to recover the delay and eliminate the synchronization error. To do.

  FIG. 24 is a diagram for explaining what path the cutting edge R center passes when the traveling direction of the program path changes from an arc to an arc. In the dotted line section with only a dotted line, the tool moves with the output of a fixed value movement pulse, and in the overlapping section where the broken line and dotted line overlap, the correction delay is added to the fixed value movement pulse to recover the delay and eliminate the synchronization error. To do.

  FIG. 25 is a diagram for explaining table format data (path table operation data) including a cutting edge R correction or a tool radius correction command when the tool rotates outside the workpiece. The path table number 3000 is the X-axis program path, the Y-axis program path, and the cutting edge R for each block of time or spindle position (L0, L1, L2, L3, L4, L5, L6, L7). Compensation or tool radius compensation command is set. The G42 command is set as modal information in the blocks L0 to L7. A block L3 is a change point of the traveling direction of the tool.

  FIG. 26 is a table showing an example of the tool position when it is assumed that the cutting edge R correction amount or the tool radius correction amount is r in the table number 3000 shown in FIG. 25 and the synchronization deviation is eliminated between L5 and L6. is there. X1 and Y1 of the block L4 and X2 and Y2 of the block L5 are set according to the set value of the moving pulse having a constant value set when moving in the dotted line section (the section of only the dotted line and the overlapping section of the dotted line and the broken line). Change.

  FIG. 27 illustrates the relationship between the program path and the tool position when it is assumed that the cutting edge R correction amount or the tool radius correction amount shown in FIGS. 25 and 26 is r, and that the synchronization deviation is eliminated between L5 and L6. It is a figure to do.

<Cancel processing>
Next, a cancel process that is a process in the case of instructing the invalidity of the cutting edge R correction or the tool radius correction in the pass table operation will be described.
When a block for instructing invalidity of the cutting edge R correction or the tool radius correction is executed in a state where the cutting edge R correction or the tool diameter correction is valid, the cutting edge R correction or the tool is performed immediately before the next change of the tool traveling direction. Correction is performed at a constant speed so that the correction amount by the diameter correction becomes 0 (zero).

  9 and 10 are diagrams showing the cutting edge R center path and the program path of the tool when the G40 command is issued. Note that the tool center path of the tool is the same as that of the tool edge R center path, and therefore, the blade edge R center path will be described below as an example.

  FIG. 9 shows a case where the traveling direction of the tool is changed from a straight line to a straight line. The tool moving through the cutting edge R center path is canceled at a constant speed so that the correction amount of the cutting edge R correction becomes 0 (zero) from the point S1 where the traveling direction of the tool changes according to the G40 command. . The cutting edge R center point 8 passes through the cutting edge R center path indicated by the broken-line arrow, and after the G40 command, the correction amount becomes 0 at the time when the traveling direction changes next (point S2 where the traveling direction of the tool changes). The operation is complete.

  FIG. 10 shows a case where the traveling direction of the tool is changed from an arc to a straight line. The tool moving through the cutting edge R center path is canceled at a constant speed so that the correction amount of the cutting edge R correction becomes 0 (zero) from the point S1 where the traveling direction of the tool changes according to the G40 command. . The tool 2 passes through the cutting edge R center path indicated by the broken arrow, and after the G40 command, the operation that the correction amount becomes 0 is completed at the time when the traveling direction changes next (point S2 where the traveling direction of the tool changes). To do.

  Next, the relationship between the program path and the tool position when the cutting edge R correction amount is r will be described with reference to FIGS. 11, 12, and 13. The same explanation can be made when the tool radius correction amount is r.

  FIG. 11 is a diagram for explaining table format data (path table operation data) including a cutting edge R correction or a tool radius correction command. The path table number 1000 in FIG. 11 includes an X-axis program path and a Y-axis program for each block of time or spindle position (L0, L1, L2, L3, L4, L5, L6, L7, L8). The path and the cutting edge R correction or the tool radius correction command are set. In L0 to L1, a G41 command is commanded as modal information, and a G40 command is issued in L2. Next, the time when the traveling direction changes (spindle position) is a point L7 shown in FIG. In FIG. 11, the notation of (G41) means that each block of L1 to L4 is instructed as a modal information as a G41 command, although it is not a G41 command block. The notation of (G40) means that each block of L3 to L8 is instructed as a modal information G40 command.

  FIG. 12 is a table showing the tool position (cutting edge R center path) when the cutting edge R correction amount or the tool radius correction amount is r in the program path of FIG. Note that the tool center path of the tool is the same as that of the tool edge R center path, and therefore, the blade edge R center path will be described below as an example. FIG. 13 is a diagram for explaining the relationship between the program path and the tool position when the cutting edge R correction amount is r as shown in FIGS. 11 and 12. In FIG. 11, since the G40 command which is a command for canceling the cutting edge R command or the tool radius correction command is set in the block L2, when the cutting edge R correction amount is set to r, the correction is performed in each block. 12, the position of the Y axis of the tool 2 is corrected. In this example, the point S where the traveling direction of the tool changes is a point where L7 changes in the traveling direction of the tool.

FIG. 28 is a flowchart for explaining an algorithm for performing cutting edge R correction or tool radius correction according to the present invention. Hereinafter, it demonstrates according to each step. In the following flowcharts, when the tool to be used is a tool that performs the cutting edge R correction, the cutting edge R correction is performed, and when the tool to be used is a tool that performs the tool diameter correction, the tool diameter correction is performed.
The process of the flowchart starts when a G40 command, a G41 command, or a G42 command is commanded.

[Step SA10] It is determined whether cutting edge R correction or tool radius correction has been commanded. If so, the process proceeds to Step SA20, and if not, the process proceeds to Step SA50.
[Step SA20] Start-up processing for cutting edge R correction or tool radius correction is executed.
[Step SA30] The main processing of cutting edge R correction or tool radius correction is executed.
[Step SA40] It is determined whether or not the correction direction has been changed or canceled. If the correction direction has been changed or cancelled, the process returns to Step SA10 to continue the process, and the correction direction has been changed or canceled. If not, the process returns to step SA30 and continues. The change in the correction direction means a change from the G41 command to the G42 command, or a change from the G42 command to the G41 command. Cancel means G40 command.
[Step SA50] A canceling process of the cutting edge R correction or the tool radius correction is executed, and the process ends.

FIG. 29 is a flowchart for explaining an algorithm of start-up processing for performing cutting edge R correction or tool radius correction according to the present invention. Hereinafter, it demonstrates according to each step.
[Step SA200] The composite speed is calculated from the movement command values of the two axes that constitute the target plane of the cutting edge R correction or the tool radius correction.
[Step SA201] The correction amount of each axis is calculated from the correction amount and correction direction of the cutting edge R correction or tool radius correction.
[Step SA202] The correction amount of each axis is added to the position command value, and the corrected movement command value is calculated.
[Step SA203] The table format data is prefetched, and the change point of the tool traveling direction is acquired.
[Step SA204] The correction amount is interpolated and output so that the correction is completed when the change point in the traveling direction of the tool is reached.
[Step SA205] It is determined whether or not an excess of speed has occurred on each axis by adding the correction amount. If it exceeds, the process proceeds to Step SA206, and if not, the process ends.

FIG. 30 is a flowchart for explaining an algorithm of main processing for performing cutting edge R correction or tool radius correction according to the present invention. Hereinafter, it demonstrates according to each step.
[Step SA300] The table format data is prefetched, and the change in the tool traveling direction is acquired.
[Step SA301] It is determined whether or not the tool is turning inside the workpiece. If the tool is turned inside, the process proceeds to Step SA302. If the tool is not turned inside, the process proceeds to Step SA304.
[Step SA302] The intersection S of the cutting edge R center path when the cutting edge R correction is performed or the tool center path when the tool radius correction is performed is calculated.
[Step SA303] The tool is stopped at the intersection S until the synchronization deviation is eliminated, and the operation starts when the synchronization deviation is eliminated.
[Step SA304] The start point and end point of the section in which movement is not included in the program path are calculated.
[Step SA305] A movement pulse having a constant value is output from the start point to the end point of the section in which the movement is not included in the program path.
[Step SA306] A fixed value of the movement pulse is added to the movement amount by the program (table format data) and output until the synchronization error is eliminated.
[Step SA307] It is determined whether or not an overspeed has occurred by adding a constant value of the movement pulse to the amount of movement made in the program in Step SA306. If overspeed occurs, the process proceeds to Step SA308, where the speed is increased. If no excess occurs, the process ends.
[Step SA308] An overspeed alarm is generated and the process is terminated.

FIG. 31 is a flowchart for explaining an algorithm for canceling cutting edge R correction or tool radius correction according to the present invention. Hereinafter, it demonstrates according to each step.
[Step SA500] The table format data is prefetched, and the change point of the tool traveling direction is acquired.
[Step SA501] The correction amount is interpolated and output so that the correction amount becomes zero when the change point in the advancing direction of the tool is reached. The correction amount means the correction amount of each axis shown in step SA201 in FIG.
[Step SA502] It is determined whether or not an overspeed has occurred by adding the correction amount. If overspeed has occurred, the process proceeds to step SA503. If no overspeed has occurred, the process is terminated. .
[Step SA503] An overspeed alarm is generated and the process is terminated.

<Means for calculating the correction amount of each axis>
(See step SA201 in FIG. 29)
Next, means for calculating the correction amount of each axis according to the present invention will be described with reference to FIG. When performing the cutting edge R correction or the tool radius correction, two axes constituting the plane to be corrected are selected. Further, it is selected whether correction is performed on the left side of the traveling direction or on the right side of the traveling direction with respect to the traveling direction of the tool on the plane to be corrected. In the following, it is assumed that the X axis and the Y axis are selected as the two axes constituting the correction plane, and the left side of the traveling direction is selected as the correction direction.

  After performing the above setting, the traveling direction on the plane to be corrected is calculated from the selected biaxial movement command value. This can be calculated by calculating the X-axis and Y-components of the synthesis speed after calculating the biaxial synthesis speed. Assuming that the X axis moves at a speed of 400 mm / min and the Y axis moves at a speed of 300 mm / min, the magnitude of the combined speed is 500 mm / min as shown in FIG.

Since the correction direction is the left side of the traveling direction, when the correction amount of the cutting edge R correction or the tool radius correction is r [mm], the correction amounts in the X-axis direction and the Y-axis direction are as follows.
-Correction amount in the X-axis direction: -r * 300/500 [mm]
-Correction amount in the Y-axis direction: r * 400/500 [mm]
From the above, the correction amount when the correction direction is the left side of the traveling direction is expressed as follows.
(Correction amount in the X-axis direction) =-r * (Y-axis speed) / ((X-axis speed) ² + (Y-axis speed) ² )) ^1/2
(Correction amount in the Y-axis direction) = r * (X-axis speed) / ((X-axis speed) ² + (Y-axis speed) ² )) ^1/2
Similarly, the correction amount when the correction direction is the right side of the traveling direction is expressed as follows.
(Correction amount in the X-axis direction) = r * (Y-axis speed) / ((X-axis speed) ² + (Y-axis speed) ² )) ^1/2
(Correction amount in the Y-axis direction) = − r * (X-axis speed) / ((X-axis speed) ² + (Y-axis speed) ² )) ^1/2

<Means for detecting a change in the direction of travel of the tool>
(See step SA203 in FIG. 29, step SA300 in FIG. 30, and step SA500 in FIG. 31)
Next, a means for detecting a change in the traveling direction of the tool will be described. The advancing direction of the tool on the plane to be corrected can be determined by the amount of movement per unit time of the two axes constituting the plane.

  When the movement amount per unit time is (X, Y) = (0.5, 1.0) and (X, Y) = (1.0, 2.0), the traveling direction is the same. I can judge. On the other hand, when the movement amount per unit time is (X, Y) = (0.5, 1.0) and (X, Y) = (2.0, 1.0), the traveling direction is Can be judged different.

Therefore, the means for detecting the change in the traveling direction of the tool can be realized by the following method.
(1) The table format data is pre-read for the two axes (X axis and Y axis) constituting the plane to be corrected, and the movement amount for each control cycle of the numerical controller is calculated.
(2) X1 / Y1 NEQ X2 / Y2 when the movement amounts of the X axis and Y axis in the previous control cycle are X1 and Y1, respectively, and the movement amounts of the X axis and Y axis in the current control cycle are X2 and Y2, respectively. Are considered as points where the direction of travel of the tool changes. Note that NEQ means an inequality sign.

  In addition, the workpiece side angle at the program path intersection required to distinguish between when the tool turns inside the workpiece and when the tool turns outside the workpiece is the inner product of the program path vectors before and after the tool change point. Based on this calculation, the angle on the workpiece side can be obtained.

<Means for calculating the intersection S of the center path of the tool for cutting edge R correction or tool radius correction>
Next, means for calculating the intersection S of the center path of the cutting edge R correction or the tool radius correction according to the present invention will be described with reference to FIG. Consider the case where the tool 2 turns inside the workpiece 4 as shown in FIG.

First, from the coordinate values from L0 to L6, the cutting edge R center path before changing the traveling direction and the cutting edge R center path after changing the traveling direction are expressed by mathematical expressions. Here, the mathematical formula of the central route before and after the change of the traveling direction is as follows.
Formula of central route before change: y = x + 1.0
Formula of central route after change: y = 10.0
The coordinate value of the intersection S at this time can be obtained by solving the simultaneous equations of the central path before and after the change of the traveling direction. Intersection S = (9.0, 10.0)
From the above, the mathematical formula of the central route before and after the change of the traveling direction is expressed as follows: The mathematical formula of the central route before the change: y = a ₁ + b ₁
Formula of the central route after change: y = a ₂ + b ₂
In this case, the coordinate value of the intersection S is expressed as follows.
Intersection S = ((b ₂ −b ₁ ) / (a ₁ −a ₂ ), (a ₁ b ₂ −a ₂ b ₁ ) / (a ₁ −a ₂ ))

<Means for calculating the start and end points of a section that moves without being on the program path>
Next, means for calculating the start point and end point of a section in which movement is not included in the program route according to the present invention will be described with reference to FIG.

Consider the case where the tool turns outside the workpiece. As shown in FIG. 34, the start point of the section in which the movement that is not in the program path is performed is L3s that is the point where the cutting edge R correction or the tool radius correction is performed on the end point L3 of the program path before the traveling direction change. Similarly, the end point is L3e, which is the point at which cutting edge R correction or tool radius correction is performed on the end point L3 of the program path after changing the traveling direction.
The coordinate values of L3s and L3e can be calculated by means for calculating the correction amount of each axis. Regarding the movement path between L3s and L3e, the following method can be considered.
Similar to the means for calculating the intersection point S of the center path of the cutting edge R correction or the tool radius correction, a method of obtaining the intersection point S from the expression of the center path before and after the change of the traveling direction and moving through the intersection point S.
A method of moving in an arc of radius R, with L3 as the center and the start and end points as L3s and L3e, respectively.

  Next, with reference to FIG. 35, a numerical control device having a function of correcting the cutting edge R or correcting the tool radius in the control based on the table format data (pass table operation data) according to the present invention will be described. FIG. 35 is a principal block diagram of a numerical controller according to an embodiment of the present invention. By executing the program based on the above-described flowchart by the numerical control device shown in FIG. 35, it is possible to execute a path table operation capable of performing blade edge R correction or tool radius correction.

  The CPU 51 is a processor that controls the numerical controller 50 as a whole. The CPU 51 reads out a system program stored in the ROM 52 via the bus 59 and controls the entire numerical control apparatus according to the system program. The RAM 53 stores temporary calculation data, display data, and various data input by the operator via the display / MDI unit 90.

  The SRAM memory 54 is configured as a non-volatile memory that is backed up by a battery (not shown) and that retains the storage state even when the numerical controller 50 is turned off. In the SRAM memory 54, a machining program read via an interface (not shown), a machining program input via the display / MDI unit 90, and the like are stored.

  Further, the above-described table format data (path table) is stored in advance. In the ROM 52, various system programs for executing processing for creating and editing a machining program are written in advance.

  A PMC (programmable machine controller) 55 outputs a signal to an auxiliary device of the machine tool via an I / O unit 56 and controls it with a sequence program built in the numerical controller 50. In addition, it receives signals from various switches on the operation panel provided in the machine tool body, performs necessary signal processing, and then passes them to the CPU 51.

  The display / MDI unit 90 is a manual data input device having a display, a keyboard, and the like. The interface 57 receives commands and data from the keyboard of the display / MDI unit 90 and passes them to the CPU 51. The interface 58 is connected to the operation panel 91 and receives various commands from the operation panel 91.

  The axis control circuits 60 and 70 for each axis receive the movement command amount for each axis from the CPU 51 and output the command for each axis to the servo amplifiers 61 and 71. In response to this command, the servo amplifiers 61 and 71 drive the servo motors 105x and 105y for the X and Y axes. Each axis servo motor 105x, 105y has a built-in position / velocity detector. The position / velocity feedback signal from the position / velocity detector is fed back to the axis control circuits 60, 61 to perform position / velocity feedback control. . In FIG. 35, the position / speed feedback is omitted.

  Further, the spindle control circuit 80 receives a spindle rotation command and outputs a spindle speed signal to the spindle amplifier 81. The spindle amplifier 81 receives the spindle speed signal and rotates the spindle motor 82 at the commanded rotational speed. The position / speed detector 83 feeds back a feedback pulse (reference pulse) and one rotation signal to the spindle control circuit 80 in synchronization with the rotation of the spindle motor 82 to perform speed control. The feedback pulse (reference pulse) and one rotation signal are read by the CPU 51 via the spindle control circuit 80, and the feedback pulse (reference pulse) is counted by a counter (not shown) provided in the RAM 53.

  In the embodiment of the present invention, an example is shown in which a feedback pulse from a position / velocity detector attached to a spindle is used as a reference pulse, the spindle is used as a reference axis, and the X axis (105x) and Y axis (105y) are used as control axes. Yes. The control axis is not limited to these and may be further increased. When increasing, the table format data (path table) of the increasing control axis is stored in the SRAM 54 which is a non-volatile memory, and the axis control circuit, servo amplifier, and servo motor are increased.

  A counter that counts the reference pulse when the main axis is not used as a reference axis, and a pulse is generated when the reference axis is provided externally or when the reference axis is moved. May be provided. Alternatively, the control axis may be the reference axis. In this embodiment, the SRAM 54, which is a non-volatile memory, stores table format data (pass table operation data) shown in FIG. 6, FIG. 11, FIG. Then, the machining program described in the table format data stored in the SRAM 54 is executed.

2 Tool 3 Tool 4 Work piece 6 Machining shape 8 Cutting edge R center point 50 Numerical control device 51 CPU
52 ROM
53 RAM
54 SRAM
55 Programmable Machine Controller 56 I / O Unit 57, 58 Interface 59 Bus 60 Axis Control Circuit 61 Servo Amplifier 70 Axis Control Circuit 71 Servo Amplifier 80 Spindle Control Circuit 81 Spindle Amplifier 82 Spindle Motor 83 Position / Speed Detector 90 Display / MDI unit 91 Operation panel 101 Counter 102 Multiplier 103 Reference position counter 105x x-axis servo motor 105y y-axis servo motor

S intersection

Claims (3)

Memory of table format data that associates time, axis or spindle position with reference time, axis position or spindle position, and axis or spindle position different from the reference axis or spindle And sequentially reading out the reference time, the position of the axis or spindle, and the position of the axis or spindle different from the reference axis or spindle, and the reference time, position of the axis or spindle In the numerical control device for controlling the position of the another axis or the main shaft in synchronization with the position of the other axis or the main shaft in synchronization with
Storage means for storing the cutting edge R correction amount or the tool radius correction amount;
Command means for commanding validity and invalidity of the cutting edge R correction or the tool radius correction to the table format data;
A correction amount for calculating a correction amount for the position of the other axis or spindle to be corrected with respect to the block of the table format data as the tool advances from the table format data and the cutting edge R correction amount or the tool radius correction amount. A calculation means;
Calculating means for calculating the position of the another axis or the main axis from the correction amount calculated by the correction amount calculating means;
Outputs the reference time, the position of the axis or spindle, and the position of the other axis or spindle corrected by correcting the synchronization deviation between the position of the other axis or spindle and the position of the axis or spindle generated by correcting the cutting edge R or the tool radius. Output means for
A numerical controller having a function of correcting the cutting edge R or correcting the tool radius in the control based on the table format data. The output means prefetches the table format data and obtains a change point of the traveling direction of the tool;
Determination means for determining whether the tool turns inside or outside the workpiece from the change point of the traveling direction of the tool acquired by the acquisition means;
As a result of the determination by the determination means, when the tool turns inside the workpiece, the tool stops until the synchronization deviation is eliminated at the tool direction change point in the corrected tool path, and the tool turns outside the workpiece. Is an adding means for adding a constant movement pulse to the movement amount by the program until the synchronization deviation is eliminated in the section where the movement is not in the program path,
The numerical control device having a function of cutting edge R correction or tool radius correction in the control with the table format data according to claim 1.   3. The alarm unit according to claim 2, further comprising an alarm unit configured to determine whether or not a value of the addition result obtained by the adding unit exceeds a set limit value, and to make an alarm when the value exceeds the limit value. A numerical control device having a function of cutting edge R correction or tool diameter correction in control by table format data.

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