JPS62292346A - Adaptation control device for machine tool - Google Patents

Abstract

PURPOSE:To greatly improve an operating property by operating a control data indicating a target load based on a set machining condition, and controlling feed speed in such a way that a detected machining load approaches said target load. CONSTITUTION:When an operator inputs the data of machining conditions such as a workpiece material, using tools, etc. through a machining condition setting means B, a target load operating means C operates a control data which indicates the optimum target load, based on the inputted machining condition data. During actual machining, a feed speed control means D is operated to control feed speed in such a way that an actual machining load detected by a machining load detecting means A approaches a target load operated by the target load operating means C. Thereby, the operator can set a target load taking machining conditions into consideration and without need for obtaining a target load by means of an experiment, greatly improving an operating property.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention <Industrial Application Field> The present invention detects a machining load and changes the feed rate so that the detected machining load approaches a target load value. The present invention relates to an adaptive control device for a machine tool.

<Conventional technology> In recent years, in order to shorten machining time, adaptive control devices with a constant load control method that control the tool feed speed so that the machining load applied to the tool becomes a constant target load have been used in numerically controlled machine tools. came to be used.

<Problem to be solved by the invention> Therefore, in such an adaptive control device, it is necessary to determine the target load value in advance and set it in the adaptive control device. The task of setting the target load value has been extremely troublesome because it must be determined based on various machining conditions such as material, tool type, spindle rotation speed, etc., or it must be determined experimentally.

<Means for solving the problem> The present invention comprises a processing load detection means A for detecting processing load;
a machining condition setting means B for setting machining conditions such as the material of the workpiece; a target load calculation means C for calculating control data representing a target load value based on the machining conditions set in the machining condition setting means B; Feed rate control means is provided for increasing or decreasing the feed rate so that the machining load detected by the machining load detection means A approaches the target load calculated by the target load value calculation means C during machining. This is a characteristic feature.

When the operator inputs data on machining conditions such as the workpiece material and the tools used using the machining condition setting means B, the target load calculation means C determines the optimal target based on the input machining condition data. Calculates control data representing the load. During machining, the feed speed control means operates to change the feed speed so that the actual machining load detected by the machining load detection means A approaches the target load produced by the target load calculation means C.

<Example> Embodiments of the present invention will be described below based on the drawings.

In FIG. 2, 10 is a numerical control device, and this numerical control device IO includes servo motor drive circuits DUX, DUY.
, DUZ, and the sequence controller 11 are connected via the enclosure interface.

On the other hand, 20 is a machining center type machine tool controlled by the numerical control device having the above configuration, and the machining is performed by the rotation of servo motors 21, 22, and 23 driven by the servo motor drive circuits DUX, DUY, and DUZ, respectively. The relative position between the workpiece table 25 that supports the object W and the main shaft rod 24 that supports the main shaft 26 driven by the main shaft motor SM is three-dimensionally changed.

Further, 27 is a tool magazine that holds a plurality of types of tools, and the tools in the tool magazine 27 are selectively mounted on the spindle 26 by the magazine indexing device in the enclosure and the tool changing device 28, so that the workpiece W can be moved. Processing is performed.

The sequence controller 11 is connected to a personal computer 12 and a spindle motor drive circuit 15 that controls the rotational speed of the spindle motor SM. This personal computer 12 includes a microprocessor 12a, a clock signal generation circuit 12b, a ROM 12c, and a RAM 12.
d, fixed disk 12e, interface 12f, 1
2g.

The keyboard 14 and the CR7 display device 13 are connected to the interface 12h.

A machining load detection circuit 16a that detects the current supplied to the spindle morph SM is interposed between the spindle motor drive circuit 15 and the spindle motor SM. Furthermore, a load detection circuit 16b that detects the current flowing through the servo motor 23 is provided between the servo motor drive circuit DUZ and the servo motor 23.
is interposed. And these load detection circuits 16
The load signals output from the terminals a and 16b are connected to the personal computer 12 via an AD converter 17 and an interface 12g.

Fixed disk 12e of the personal computer 12
Inside, a plurality of storage areas CDFI to CDF99 for setting and storing target load values are formed in a file format as shown in Fig. 3 (as shown in Fig. 3). , the file name, detection axis, target load value LT, upper tolerance range width UR1, and lower tolerance range width LR are stored.

Note that the file name consists of T followed by a three-digit number, and this three-digit number represents the tool number used.

The personal computer 12 has an adaptive control function and the type of machining, machining dimensions, and
It has an automatic program function that automatically creates a numerical control program based on machining conditions such as the workpiece material and supplies it to the numerical control device 10.

Although the functions of the automatic program will not be described in detail, data such as the material of the workpiece, the type of machining, and machining dimensions inputted for each machining process are stored in an interactive data file on the fixed disk 12e.

Next, the personal computer 12 related to the adaptive control function
The operation will be explained.

1. Operation when setting the target load When setting the target load in the machine tool adaptive control system configured as described above, the operator first selects the initial setting program by following the menu displayed on the CR7 display device 13. do.

As a result, the microprocessor 12a of the personal computer 12 executes the program shown in FIG. It is displayed on the screen, and in response to this, the operator manually enters the 3-digit tool number, which is read (30), and a file name is created by adding a T in front of the input 3-digit number. Secure a storage area on the fixed disk 12e with this file name (31). After this, input data such as sampling interval and allowable range width on the screen, and when these data are entered manually, this are stored in the created memory file (32) to (34). For example, when machining is performed using tool No. 23 as described later, input 023 to form a file with the file name T023, and this After that, input the initial data mentioned above.

After inputting the above data, the operator follows the menu displayed on the CR7 display device 13 and selects the target load setting program. As a result, the microprocessor 12a of the personal computer 12 executes the program shown in FIG. When this program is executed, the microprocessor 12a displays the screen shown in FIG. The operator is asked to specify whether to input a new input (4o).

When the operator selects data input, the microprocessor 12a displays the screen shown in FIG. 5(b) on the CR7 display device 13, prompts the operator to select the material of the workpiece, and indicates that the type of machining is drilling. The operator is asked to select whether it is milling or milling (43).

When the operator inputs these data, the microprocessor 12a stores these data and, if drilling is selected, displays the screen shown in FIG. 5(C) and prompts the operator to input machining condition data ( 44).

The operator follows the display on this screen and inputs the data of the tool number, load detection axis, drill diameter, spindle rotation speed, and standard feed rate, and the microprocessor 12a temporarily stores these data in the memory.

In the case of milling, similar data input is performed on the screen shown in FIG. 5(d).

On the other hand, when using dialogue data, the process number is displayed and data such as the tool number and drill diameter are read out from the dialogue data file41), and only data not registered in the dialogue data file is input to the operator. let (42).

When the machining condition data is input as described above, the microprocessor 12a calculates a target load value based on the input data (46).

In the case of drilling, the calculation formula for this target load value differs depending on whether adaptive control is performed by detecting the spindle load or by detecting the feed load. When performing adaptive control by detecting the spindle load, the formula (1) below is used. When the target load is calculated by using Equation (2), when the feed load is detected, the target load LO is calculated using Equation (2). (11, (In formula 21, N is the spindle rotation speed, F is the feed rate, M is the workpiece material coefficient, D is the drill diameter, KL is the drive current-output torque coefficient of the feed motor, and 01 to C7 are constants. be.

L O= C1・(C2・N+C3・F)・M−D2
+C4...(1) Then, store this target load LO together with the detection axis data in a file whose file name is the tool number (47)
.

Perform these data entries for each of the tools used to complete the data entry.

2. When machining a workpiece using motion adaptive control, the personal computer 12 is set to the monitoring mode and the microprocessor 12a
The program shown in Fig. 6 is executed, and the numerical control device 10 is made to read a machine program in which M57 and M2S codes are programmed before and after the range where adaptive control machining is to be performed, as shown in Fig. 7, and the numerical control Start up the device 10.

By executing this program, M57 programmed in block N120 is read out, and when this code data is transferred to the personal computer 12 via the sequence controller 11, the microprocessor 12a of the personal computer 12 executes the steps. It is determined in (60) and the process moves to step (62).

When moving to step (62), the T code of the spindle tool stored in the sequence controller 11 is inputted from the sequence controller 11, and the data in the storage area with the same file name as the T code is read from the fixed disk 12e. ), then MFIN to the numerical control device 10.
A signal is output (64). Following this, the microprocessor 12a sets time data corresponding to the sampling interval in the clock generation circuit 12b, and causes the clock signal generation circuit 12b to output a sampling clock (65
).

Every time a clock is sent from this clock signal generation circuit 12h, the microprocessor 12a performs step (67).
) to execute the process of step (74). First, in step (67), it is checked whether M5B code data specifying the end of adaptive control has been sent.

If M2S code data is not output, T
The data of the target load values ■ and o are read from the file 032 (68), and the positive and negative allowable range widths tJR and UL are added and subtracted to the successive target load values LO to obtain the upper limit value UL.
and the lower limit value LL is calculated (69). Thereafter, the actual machining load is detected from the output of the AD converter 17 (70), and the override value is increased or decreased so that the detected machining load falls within the upper and lower limits (71) to (74). Note that the detection of the actual machining load is performed based on the output of the load detection circuit 16a when the detection axis is set to the main axis, and when the detection axis is set to the Z
If it is set to the axis, it is performed based on the output of the load detection circuit 16b.

In this way, adaptive control processing is performed, and the code data of M5B is read out by the numerical control device 10 and sent to the personal computer 1 via the sequence controller 11.
2, the microprocessor 12a determines this in step (67), performs clock stop processing (75), outputs MFIN (76), and performs clock stop processing (76) based on the data in the storage area with file name T023. (Completes adaptive control and returns to step (60).

Then, when the M code data representing the completion of the program is output to the microprocessor 12a, the adaptive control processing is completed.

<Effects of the Invention> As described above, in the present invention, the target load suitable for the machining conditions can be automatically calculated and set by manually inputting the machining conditions such as the workpiece material. There is no need to set the target load in consideration of machining conditions or to find the target load through experiments, which has the advantage of greatly improving work efficiency.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram for clearly demonstrating the present invention, Figures 2-
FIG. 7 shows an embodiment of the present invention, FIG. 2 is an overall view of a machine tool equipped with an adaptive control device, and FIG. 3 shows a storage area formed on the fixed disk 12e in FIG. 4 is a flowchart showing the operation of the microprocessor 12a in FIG. 2 during data input; FIG. 5 is a diagram showing the display screen of the CR7 display device 13 in FIG. 2; FIG. 6 is a flowchart showing the operation of the microprocessor 12a in FIG. 2 during machining, and FIG. 7 is a diagram of a program sheet showing an example of the Kani program. DESCRIPTION OF SYMBOLS 10... Numerical control device, 12... Personal computer, 12a... Microprocessor, L2e.=
Fixed disk, 16a, 16b...Load detection circuit, 1
7...AD converter, 20...Machine tool.

Claims (1)

[Claims] (1) In an adaptive control device for a machine tool that detects a machining load and changes the feed rate so that the detected machining load approaches a target load value, the machining load detection means for detecting the machining load; A machining condition setting means for setting machining conditions such as the material of the object, a target load calculating means for calculating control data representing a target load based on the machining conditions set in the machining condition setting means, Adaptive control of a machine tool, characterized in that it is provided with a feed rate control means for increasing or decreasing the feed rate so that the machining load detected by the load detection means approaches the target load value calculated by the target load calculation means. Device.