JP2010092405A - Numerically-controlled machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a numerically-controlled machine tool capable of associating a time chart of an instruction value, a feedback value, and a processing load in a movement instruction, and a processing program, and displaying them on the same screen. <P>SOLUTION: The numerically-controlled machine tool that comprises a feed shaft drive means for driving a feed shaft of the machine tool, a main shaft drive means for rotatably driving a main shaft equipped with a tool, a control means for controlling the feed shaft drive means and the main shaft drive means based on the processing program, and a display means, acquires, in real time, time-series data of an instruction value, an FB value and a processing load in the movement instructed by each movement instruction while processing a workpiece based on the processing program, associates the time chart of the instruction value, the FB value and the processing load, and the processing program, and displays them on the same screen of the display. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a numerically controlled machine tool, and more particularly to a machine that can display the state of a machine tool on a screen during movement execution (including during machining) according to each movement command.

  Conventionally, it is necessary to set a cutting speed or the like when creating a machining program to be used for machining a workpiece in a numerically controlled machine tool. In this case, the cutting speed recommended by the manufacturer is often adopted based on the catalog and technical data of the cutting tool manufacturer. However, the cutting speed recommended by the manufacturer has a large margin, so there is a limit to increasing the cutting speed. Here, in order to determine whether or not the cutting speed in each cutting process is appropriate, it is necessary to correctly grasp the processing load.

Therefore, in Patent Document 1, each NC command is idled, reference value data (disturbance load torque) relating to the machining load is acquired and stored in a memory, and the actual machining is performed by the machining load detection means. A machining load monitoring system is described in which a machining load is detected and an alarm is output when the actual machining load is greater than a corresponding reference value data by a predetermined value or more.
JP-A-8-85044

  The technique of Patent Document 1 is a machining load monitoring technique for monitoring whether or not the actual machining load is larger than the reference data, and it is possible to know which NC command in the machining program has a large machining load. However, when the machining load becomes larger than a predetermined value, it has not been possible to determine how much the load is.

  An object of the present invention is to provide a numerically controlled machine tool capable of grasping how much the machining load is limited.

  The numerically controlled machine tool according to claim 1 is a feed shaft drive means for driving a feed shaft of a machine tool, a spindle drive means for rotationally driving a spindle to which a tool is attached, and the feed shaft drive means based on a machining program. In a numerically controlled machine tool comprising a control means for controlling the spindle driving means and a display means connected to the control means, an identification label is attached to each movement command during machining of a workpiece based on a machining program In addition, data acquisition means for acquiring in real time processing load time series data in the movements commanded by each movement command, processing load time chart and processing obtained from the processing load time series data acquired by the data acquisition means And a first display control means for displaying the program in association with the same screen of the display means.

  The numerically controlled machine tool according to claim 2 is characterized in that, in the invention according to claim 1, the data acquisition means also acquires time series data of a command value and a feedback value in a movement commanded by each movement command in real time. Yes.

  According to a third aspect of the present invention, in the numerical control machine tool according to the second aspect, the first display control means displays the command value based on each movement command, a feedback value, a time chart of a machining load, and a machining program as the display means. It is characterized by being displayed in association with the same screen.

  According to a fourth aspect of the present invention, the numerically controlled machine tool according to the second aspect of the invention stores the command value, the feedback value, and the time series data of the machining load acquired by the data acquisition means in association with the movement command and the identification label. After the processing by the information storage means and the processing program, the time series data stored in the data storage means is read out, and the command value, the feedback value, the processing load time chart, and the processing program are displayed on the same screen of the display means. And a second display control means for displaying in association with each other.

  According to the first aspect of the present invention, the data acquisition means and the first display control means are provided, and the time chart of the machining load when the machining according to each movement command is executed and the machining program are displayed on the same screen of the display means. When the machining program block corresponding to the movement command with a large machining load is corrected, the portion with the large machining load is picked up from the machining load time chart, and the corresponding movement command (of the machining program) is displayed. Some) can be corrected. In this way, the machining program can be easily and efficiently corrected.

  According to the invention of claim 2, since the data acquisition means also acquires the time series data of the command value and the feedback value in each movement command, it becomes possible to create these time charts.

  According to the invention of claim 3, the command value, feedback value, machining load time chart and machining program in each movement command are displayed in correspondence with the same screen of the display means. Can be easily grasped, that is, a portion with a large machining load, and can be used to modify a machining program.

According to the invention of claim 4, when machining a workpiece by the machining program, the command value, the feedback value, and the time series data of the machining load are acquired and stored, and after the machining is finished, the command value and the feedback value are Since the processing load time chart and the processing program are displayed in association with the same screen of the display means, the location where the difference between the command value and the feedback value is large, that is, the location where the processing load is large, can be easily grasped and dealt with. The movement command (part of the machining program) can be corrected. In this way, the machining program can be easily and efficiently corrected. In addition, it is possible to easily grasp the part where the processing load is small, and the cutting conditions (
By increasing the cutting speed, the cutting time (cycle time) of the entire processing can be shortened.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

  A machine tool 1 shown in FIG. 1 is a numerically controlled machining center capable of performing desired machining (for example, “drilling”, “cutting”, etc.) on a workpiece by relatively moving the workpiece and a tool. is there. The machine tool 1 includes an iron base 2 that serves as a base, a machine main body (not shown) that is fixed to the upper portion of the base 2 and performs workpiece cutting, and is fixed to the base 2. And a box-shaped splash cover 4 covering the top of the.

  As shown in FIGS. 1 and 2, the base 2 is formed in a substantially rectangular parallelepiped shape that is long in the Y-axis direction (the direction perpendicular to the plane of FIG. 1). Legs 2a whose heights can be adjusted are respectively provided at the lower four corners of the base 2, and the machine tools 1 are installed at predetermined installation locations by installing these four legs 2a on the floor of a factory or the like. .

  A splash cover 4 shown in FIG. 1 is formed in a substantially rectangular parallelepiped box shape, and a machine main body and a processing region thereof are provided inside thereof. An opening (not shown) is provided on the front surface of the splash cover 4, and a pair of sliding opening / closing doors 5 and 6 are provided in the opening.

  A rectangular glass window 5a, 6a is provided at the approximate center of the doors 5, 6, respectively, a handle 5b is provided at the right end of the door 5, and a handle 6b is provided at the left end of the door 6. is there. The opening portions are opened by opening these handle portions 5b, 6b away from each other, and the operator attaches / detaches the workpiece to / from a table (not shown) fixed to the upper portion of the base 2.

  A rectangular operation panel 80 for operating the machine tool 1 is provided on the right side of the front opening. The operation panel 80 includes a keyboard 81 having a numeric keypad and various operation switches, and a display 82. The display 82 is for displaying a setting screen or an execution operation, and is provided above the keyboard 81.

  The operator operates the keyboard 81 while checking the display 82 of the operation panel 80 to set a machining program for executing workpiece machining, tool information, various parameters, and the like.

Next, the machine body 3 will be described.
As shown in FIG. 2, the machine body 3 includes a column 5, a spindle head 7, a spindle 9, a tool changer (ATC) 20, and a table 10. The column 5 is fixed to the upper surface of the column seat portion 4 on the rear portion of the base 2 and extends vertically upward. The spindle head 7 is provided so as to be movable up and down along the front surface of the column 5. The main shaft head 7 supports the main shaft 9 in a rotatable manner.

  The tool changer 20 is provided on the right side of the spindle head 7 and exchanges by attaching a tool holder (not shown) with a tool to the tip of the spindle 9. A table 10 is provided on the upper part of the base 2, and a workpiece is fixed to the table 10 so as to be detachable. A box-shaped control box 6 is provided on the back side of the column 5. A numerical controller 50 (see FIG. 3) for controlling the operation of the machine tool 1 is provided inside the control box 6.

Next, the moving mechanism of the table 10 will be described.
As shown in FIG. 2, the table 10 is moved in the X-axis direction (the left-right direction of the machine body 3) and the Y-axis direction (the depth direction of the machine body 3) by an X-axis motor 71 and a Y-axis motor 72 that are servo motors. Driven by movement. This moving mechanism has the following configuration. A rectangular parallelepiped support base 12 is provided below the table 10. A pair of X-axis feed guides extending along the X-axis direction are provided on the upper surface of the support base 12, and the table 10 is movably supported on the pair of X-axis feed guides.

  A support base 12 is provided on the upper portion of the base 2 and is movably supported on a pair of Y-axis feed guides extending along the longitudinal direction of the base 2. The table 10 is driven to move in the Y-axis direction along the Y-axis feed guide by a Y-axis motor 72 provided on the base 2. The table 10 is driven to move in the X-axis direction along the X-axis feed guide by an X-axis motor 71 provided on the support 12.

  Telescopic covers 13 and 14 that contract in a telescopic manner are provided on the left and right sides of the table 10 in the X-axis feed guide. In the Y-axis feed guide, a telescopic cover 15 and a Y-axis rear cover are provided before and after the support base 12, respectively. The X-axis feed guide and the Y-axis feed guide are always covered with telescopic covers 13, 14, 15 and a Y-axis rear cover. Therefore, it is possible to prevent the chips scattered from the processing region, the splash of coolant liquid, and the like from falling on each axis feed guide.

Next, the raising / lowering mechanism of the spindle head 7 will be described.
As shown in FIG. 2, the spindle head 7 is supported by a guide rail extending in the vertical direction on the front side of the column 5 so as to be movable up and down via a linear guide. The spindle head 7 is connected to a feed screw extending in the vertical direction on the front side of the column 5 by a nut. The spindle head 7 is driven up and down in the vertical direction by rotationally driving the feed screw in the forward and reverse directions by a Z-axis motor 73 (see FIG. 2).

Next, the main shaft 9 will be described.
As shown in FIG. 2, the spindle 9 is rotationally driven by a spindle motor 74 provided on the upper part of the spindle head 7. A holder mounting hole (not shown) that increases in diameter toward the tip is provided in the tip side portion of the main shaft 9. As shown in FIG. 2, the tool changer 20 grips and conveys a tool magazine 21 that stores a plurality of tool holders that support tools, a tool holder attached to the spindle 9, and other tool holders. A tool change arm 22 and the like are provided. The tool magazine 21 includes a plurality of tool pots that support the tool holder and a transport mechanism that transports the tool pots within the tool magazine 21.

Next, the electrical configuration of the numerical controller 50 will be described.
As shown in FIG. 3, the numerical controller 50 includes a microcomputer including a CPU 51, a ROM 52, and a RAM 53, an input interface 54, and an input / output interface 55. The input interface 54 is electrically connected with a keyboard 81 of the operation panel 80 and a Z-axis origin sensor 77 for detecting the origin of the main axis in the Z-axis (Z-axis origin). The ROM 52 stores a control program for display control such as machining load described later. The RAM 53 is provided with a data storage area for storing display data such as various machining loads acquired during machining of the workpiece and various work memories.

  The input / output interface 55 drives an X-axis drive circuit 61, a Y-axis drive circuit 62, a Z-axis drive circuit 63, a spindle drive circuit 64 that drives the spindle motor 8, and a display 82 of the operation panel 80. The CRT drive circuit 65 and the pump drive circuits 67 and 68 for driving the pumps 75 and 76 for supplying the coolant liquid to the injection nozzle and the center hole of the tool are electrically connected to each other.

  An X-axis motor 71 with an encoder 71a is connected to the X-axis drive circuit 61. An X-axis motor 72 with an encoder 72a is connected to the Y-axis drive circuit 62. A Z-axis motor 73 with an encoder 73a is connected to the Z-axis drive circuit 63. A Z-axis motor 74 with an encoder 74a is connected to the main shaft drive circuit 64.

  Based on the control signal from the CPU 51 of the numerical controller 50, the X-axis drive circuit 61, the Y-axis drive circuit 62, and the Z-axis drive circuit 63 drive the X-axis motor 71, the Y-axis motor 72, and the Z-axis motor 73, respectively. Thus, the table 10 can be moved to a desired position, and the spindle head 7 can be moved to a desired position in the height direction.

Next, the display control of the machining load and the like will be described based on the flowcharts of FIGS. In the figure, symbol Si (i = 1, 2,...) Indicates each step.
After the start of control, the designated machining program is displayed on the screen of the display 82 (S1). Next, the workpiece material to be processed as a test is fixed on the table 10 and program execution is started (S2). Next, one block (one line) of the machining program is read (S3).

  Next, it is determined whether or not the program is finished (S4). When the determination is No, the process proceeds to S5, and when the determination is Yes, the control is ended. In S5, it is determined whether or not the read block is a “movement command”. This “movement command” includes both a rapid feed command and a cutting feed command being processed. When the determination in S5 is No, the command execution is started in S6, and when the command execution is completed (S7: Yes), the process proceeds to S3.

  As a result of the determination in S5, if the read command is a movement command, identification labels (L1, L2,... Shown in FIG. 5) are attached to the movement command (S8). Next, execution of a movement command is started in S9. In the next S10, the command value, the feedback value (hereinafter referred to as FB value), and the machining load data of the designated movement axis (any of the X axis, Y axis, and Z axis) are acquired. In this case, the command value can be known directly from the machining program or through arithmetic processing. The feedback value can be determined from detection data of the commanded moving axis encoders 71a to 73a. When the machining load is large, the value of (command value−FB value) increases. Therefore, an actual error (command value−FB value) is adopted as a physical quantity reflecting the “machining load”. If the actual error is small, it can be determined that the processing load is small.

Next, in S 11, the movement command, identification label, command value, FB value, machining load, and time data (time series data) are stored in the data storage area of the RAM 53. FIG. 5 shows an example of data stored in the data storage area of the RAM 53. The above data is stored for each machining program. Next, in S12, the command value, the FB value, and the processing load time chart are displayed on the same screen of the display 82 so as to be identifiable for each movement command.
For example, as shown in FIG. 6, the X-axis movement command and FB value time chart and the processing load (actual error) time chart which is the difference between the command value and the FB value are shown on the left side of the screen of the display 82. The machining program is displayed in the right area of this screen.

  In addition, for example, the movement command G0X, the corresponding command value, the FB value, and the machining load become green so that the machining program, the movement command included in the machining program, the command value and the FB value, and the machining load correspond to each other. Displayed. The movement command G1X, the corresponding command value, the FB value, and the machining load are displayed in red, for example. The movement command G6X, the corresponding command value, the FB value, and the machining load are displayed in, for example, yellow. In this way, display is performed with different display colors so that the correspondence between the movement command, the command value corresponding to it, the FB value, and the machining load becomes clear. The marker M is also displayed on the screen. After the movement command is instructed by the marker M, the content of the movement command is corrected, and the corrected machining program can be saved.

In addition, instead of the method of associating the movement command, the command value, the FB value, and the machining load via the display color as described above, the identification labels (L1, L2,... Correspondence may be achieved by displaying the command value, the FB value, and the vicinity of the machining load.
The display example of FIG. 6 is an example in which the X axis is designated and displayed. When the Y axis is designated, the command value, FB value, actual error, and machining program related to the Y axis are displayed in the right area of the screen. When the Z axis is specified, the command value, FB value, actual error, and machining program related to the Z axis are displayed in the left area of the screen.

  Next, in S13, it is determined whether or not the movement command is completed. If the determination is No, the process returns to S10 and executes S10 and subsequent steps. If the movement command is completed, the process returns to S3 and executes S3 and subsequent steps. If it is determined in S4 that the machining program is finished, this control is finished. This control is executed in a control cycle of a predetermined minute time.

  Next, among the display control for processing load and the like, the control for reading the data stored in the data storage area of the RAM 53 by the control shown in FIG. 4 and displaying it on the screen of the display 82 as shown in FIG. After the start of control, the designated machining program is displayed in the right area of the screen of the display 82 (S20). Next, analysis of the program is started (S21). Next, one block (one line) of the machining program is read (S22).

  Next, it is determined whether or not the program is finished (S23). When the determination is No, the process proceeds to S24, and when the determination is Yes, the control is ended. In S24, it is determined whether or not the read block is a “movement command”. If the determination in S24 is No, the process returns to S22, and S22 and subsequent steps are repeated.

  If the read command is a movement command as a result of the determination in S24, the identification label of the movement command is read (S25). Next, in S26, the command value, FB value, machining load, and time data (time series data) corresponding to the movement command and the identification label stored in the data storage area of the RAM 53 are read. Next, in S27, as shown in FIG. 5, a time chart of the command value, the FB value, and the machining load is displayed in the left area of the screen of the display 82 so as to be identifiable by movement command. In this case as well, similarly to S12, the display color is changed for each movement command, so that the command value, the FB value, the machining load, and the movement command of the machining program are displayed in association with each movement command.

  Next, in S28, it is determined whether or not the movement command is finished. If the determination is No, the process proceeds to S26. If the determination in S28 is Yes, the process returns to S22, and S22 and subsequent steps are repeatedly executed. If it is determined by S23 that the machining program is finished, this control is finished. The above control is executed in a control period of a predetermined minute time.

The operation and effect of the numerically controlled machine tool described above will be described.
In order to display a processing load time chart and processing program when executing processing by each movement command in association with the same screen of the display 82, the portion of the processing program corresponding to the movement command having a large processing load is corrected. At this time, it is possible to quickly pick up a portion with a large machining load from the machining load time chart, and to quickly correct the corresponding movement command (part of the machining program). In this way, the machining program can be easily and efficiently corrected.
In addition, it is possible to easily grasp a part with a small machining load (a part with a small actual error), and shorten the cutting time (cycle time) of the whole machining by increasing the cutting condition (cutting speed) at that part. .

  Since time series data of command values and feedback values in each movement command is also acquired, it is possible to create and display these time charts. In order to display the command value, feedback value, machining load time chart and machining program for each movement command in correspondence with the same screen of the display 82, the location where the difference between the command value and the feedback value is large, that is, the machining load is large. The location can be easily grasped and can be used to modify the machining program.

  When machining a workpiece with a machining program, the command value, feedback value, and time series data of the machining load are acquired and stored. After the machining is completed, a time chart of the command value, feedback value, machining load, and machining program Are displayed in association with the same screen of the display 82, so that a part where the difference between the command value and the feedback value is large, that is, a part where the machining load is large, is easily grasped, and a corresponding movement command (part of the machining program) Can be corrected. In this way, the machining program can be easily and efficiently corrected.

  When the above command value, feedback value, machining load time chart, and machining program are displayed on the same screen of the display, the above time chart for each specified axis (X axis, Y axis, or Z axis). Therefore, the display information on the screen is not complicated, it is easy to see, and it is easy to use.

Next, an example in which the above embodiment is partially changed will be described.
1] In the above embodiment, (command value−FB value) is adopted as the machining load, but the drive currents of the motors 71 to 73 may be used as the machining load. Since the drive current of each axis motor is detected by the current detector in each axis drive circuit 61 to 63, the machining load of each axis can be surely known by acquiring the detected current value.

2] When assigning consecutive block numbers to a large number of blocks in the machining program,
The block number may be adopted as the identification label.

1 is a front view of a machining center according to an embodiment of the present invention. It is a perspective view of the machine main body of a machining center. It is a block diagram of a numerical controller. It is a part of flowchart of display control, such as processing load. It is explanatory drawing of the time-series data of an identification label, a movement command, command value, FB value, and processing load. It is a figure which shows the example of a display on the screen of a display. It is the remainder of the flowchart of display control, such as processing load.

Explanation of symbols

1 Machining center (Numerically controlled machine tool)
50 Numerical control device 61 X-axis drive circuit 62 Y-axis drive circuit 63 Z-axis drive circuit 64 Main-axis drive circuit 71 X-axis motor 72 Y-axis motor 73 Z-axis motor 74 Main-axis motor 82 Display

Claims (4)

Feed shaft drive means for driving a feed shaft of a machine tool, spindle drive means for rotationally driving a spindle to which a tool is attached, and control means for controlling the feed shaft drive means and the spindle drive means based on a machining program And a numerically controlled machine tool comprising display means connected to the control means,
A data acquisition unit that attaches an identification label to each movement command while processing a workpiece based on the processing program, and acquires time series data of a processing load in the movement commanded by each movement command in real time;
First display control means for displaying a processing load time chart obtained from time series data of the processing load acquired by the data acquisition means and a processing program in association with the same screen of the display means;
A numerically controlled machine tool characterized by comprising:   The numerically controlled machine tool according to claim 1, wherein the data acquisition unit also acquires time-series data of a command value and a feedback value in a movement commanded by each movement command in real time.   The display control means displays a command value based on each movement command, a feedback value, a machining load time chart, and a machining program in association with the same screen of the display means. Numerically controlled machine tools. Information storage means for storing the command value, feedback value, and processing load time series data acquired by the data acquisition means in association with the movement command and the identification label;
After completion of machining by the machining program, the time series data stored in the data storage means is read, and the command value, feedback value, machining load time chart, and machining program are displayed in association with the same screen of the display means. The numerically controlled machine tool according to claim 2, further comprising second display control means.