KR100478241B1 - Tools Measuring and Compensation Method of Machining Center - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool measurement and calibration method of a machining center, and in detail, supports a device setting mode, a manual measuring mode, and an automatic measuring mode. According to the mode, it is possible to maintain the machining precision of the CNC equipment by measuring the position value of the measurement measuring device probe, measuring the radius and length of the tool mounted on the main shaft, and determining whether the tool is worn or damaged. According to the tool measurement and correction method of the machining center, tool measurement is possible regardless of the tool shape due to the diversification of the tool used, and the tool interruption time for tool measurement can be compensated by correcting tool data according to the wear of the tool even during the process. It can reduce the size and provide a user-friendly advantage.

Description

Tool Measuring and Compensation Method of Machining Center

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool measurement and calibration method of a machining center, and more particularly, to a tool measurement and calibration method of a machining center capable of maintaining machining precision of CNC equipment by monitoring wear and damage of a used cutting tool.

In the mold machining process using machining centers, tool wear due to prolonged machining directly affects product precision and surface roughness. To prevent this, a tool monitoring system with a high degree of measurement speed is essential. Tool wear measurement method is a direct method of measuring tool wear such as CCD camera, laser sensor, etc., and cutting force is estimated by using physical factors generated during cutting process such as spindle motor current, acoustic emission signal, and surface temperature And accordingly there is an indirect method for predicting the amount of wear of the tool, but tool setting probe (tool setting probe) is used as a commercial technology.

The program needed to connect the tool setting probe and the CNC controller and measure is written using the user macro, but it is difficult for the user to use the macro program. Therefore, simple and low precision measurement is possible using only the simple measurement macro program supported by the CNC manufacturer. It is done.

It is possible to produce small quantities of various products by the flexible production system of CNC equipment according to the automation of processing equipment, but the tool measuring system due to the diversification of used tools does not follow this situation, and the research and development of measuring algorithms for various tool measuring is required. However, due to the lack of interpolation function due to the measurement speed, the measurement result cannot be corrected.

In addition, the measuring device is attached to the table (measurement space) of the CNC equipment, and the dial gauge is installed on the main axis of the equipment to input the measurement position to the CNC controller. Tool measurement is performed by inputting to the CNC controller, but due to the difficulty of selecting the concentric position due to the displacement of the probe due to the measured pressure of the dial gauge, there is a problem of excessive installation time and low position accuracy. In the tooling process, tool presetters and height presetters are additionally used, resulting in an increase in facility investment cost and a reduction in the available time of CNC equipment.

The present invention is to solve the above problems, it is possible to measure the tool irrespective of the type and shape of the tool used in the machining center, acquisition of the installation position value of the measuring device for measurement, automatic acquisition of the initial tool measurement value, It is an object of the present invention to provide a tool measuring and calibration method of a machining center that can measure the wear value and correct the tool value before the start of the use tool and during the driving of the machining program. It is still another object of the present invention to provide a measurement system capable of setting the necessary parameters for the user preparation function G code and optimal measurement so that it can be used regardless of the CNC controller used, and the interpolation of precision according to the measurement speed is possible, thereby improving the measurement accuracy by the measurement speed. It is possible to provide tool measurement and compensation methods for machining centers.

Tool measurement and calibration method of the machining center according to the present invention in order to achieve the above object is a process required for tool measurement and calibration, the device setting mode for obtaining the installation position of the measuring device for measurement, the machining center after the selection of the tool required for product processing Manual measurement mode to input the tool compensation value of CNC controller by acquiring the length and radius of the tool by installing it on the main axis, and automatic measurement mode process that enables automatic measurement and tool compensation by the measurement preparation function code during the machining process. It includes.

Hereinafter, described in detail with reference to the accompanying drawings.

1 is a flow chart showing a tool measurement and calibration process of the machining center according to the present invention. In addition, Tables 1 and 2, listed below, are stored so that the programs stored in the tool measuring system of the micronization center can be recognized. Indicates the auxiliary function M code function required.

Referring to FIG. 1, first, a user inputs a code including a tool measurement G code set in association with the selection of a tool measurement mode (step 1). In the code input process, the above-described arguments and variable values can be input together. The machining center then determines whether the input code is a G code corresponding to the device setting mode, manual measurement mode or automatic measurement mode. Here, the device setting mode measures the position of the measuring instrument probe mounted with a T-bolt at the free position of the machining center work table, and then automatically measures the position of the measuring instrument probe with the macro variable on the CNC controller. Inputting device location and storing it for later use. Manual measurement mode refers to measuring tool data such as radius and length of a selected tool mounted on a spindle and automatically inputting measured tool data to CNC controller. In this case, machining is performed immediately with the input tool data value. can do. In addition, the automatic measurement mode executes a program that automatically monitors whether or not a tool mounted on the spindle is worn before and during cutting using a CNC machining program. The measurement position and measurement point are determined according to the selected value, and the tool measurement is performed by determining the measurement frequency at each measurement position according to the repetition frequency (K) value selected by the user. In addition, when the difference between the currently measured tool data and the previously stored tool data for the same tool is out of the set damage range through the automatic measurement mode, an internal alarm is generated and the operation of the equipment is stopped. In addition, if the difference between the currently measured tool data and the previously stored tool data for the same tool is within the set range through the automatic measurement mode, it is determined as normal wear and tear, and the currently measured tool data is automatically transferred to the CNC controller. In the example shown for each of these modes, G100 is indicated by a code corresponding to the device setting mode, G101 is indicated by a code corresponding to the manual measurement mode, and G102 is an automatic measurement mode. It is indicated by the code corresponding to. In addition, the contents related to each mode, argument, and variable setting are recorded in the storage device. Therefore, if the code input by the user in the code judging step includes G100, the mode is set to the device setting mode (step 3). When it is set to the device setting mode, the machining center calls the measurement condition corresponding to the device setting mode. Here, the measurement conditions refer to conditions set for measurement positions, measurement directions, etc. corresponding to arguments or variables included in the code input in the code input step and other default values for the process for measurement. Thereafter, the positions of the contact points when the mutually different positions are contacted with each other by moving the main axes of three different positions with respect to the measurement measuring device probe (step 8), and the position of the measured measuring device probe is measured by the CNC controller. Enter and save as device location value (step 11). A more detailed description of performing the device setting mode will be described later. On the other hand, if the code entered by the user in the code judging step includes G101 is set to the manual measurement mode (step 3). If it is set to manual measurement mode, the machining center judges whether the position value of the measuring device probe is needed, and if not, it generates an alarm.If it is saved, it calls the measurement condition and then moves the spindle. By measuring the length or radius of the tool using the position value of the point of contact when the tool to be mounted on the spindle contacts the probe of the measuring device (step 9), the measured value can be used for subsequent machining. Save it as tool compensation information for the CNC controller (step 12). A more detailed description of the manual setting mode will be described later. If the code input by the user in the code determining step includes G102, the automatic setting mode is set (step 5). When it is set to the automatic measurement mode, the machining center determines whether the position value of the measuring device probe necessary for performing the automatic measurement mode is stored (step 6), and if not, generates an alarm (step 25) and stores the If yes, call the measuring condition (step 7), and then move the spindle to measure the length or radius of the tool using the coordinates of the contact points when the measuring tool mounted on the spindle contacts the measuring instrument probe ( Step 10), the current measured value is stored as tool compensation information of the CNC controller for use in subsequent machining (step 13). A more detailed description of the automatic measurement mode will be described later.

First, the sequence of the device setting mode will be described in more detail with reference to FIG. 3. If the measurement condition called in the measurement condition call step after step 3 of FIG. 1 is a three-position measurement, as shown in FIG. The measuring instrument probe of the type is moved in the direction of the arrow shown so as to contact at three different points. That is, when the tool of the main axis moves to the 8a position and contacts the probe, the coordinate value of the contact point at this time is stored, and the main axis is retracted and moved to the opposite side, and then proceeds to the 8c position to contact the probe. After storing the value, contact the probe at the position 8b again to store the coordinate value of the third contact point, and then calculate the center value of the probe by using the circle equation from the X and Y coordinate values for each contact point. Next, move the tool of the main shaft to the upper surface of the probe and then lower it in 8d direction. When the tool of the main axis contacts the probe, calculate the Z position of the probe at this time. Automatically input the position value of the measuring device probe. On the other hand, if there is no initial macro variable for the measuring device probe for measurement, the user manually moves the tool of the spindle to 8a position using a manual pulse generator (MPG), and then generates a contact signal. As described above, the measurement is performed automatically, and the measurement for accuracy correction after initial measurement is performed after the main axis is automatically aligned to the collision avoidance position of 8a by the input macro variable.

Next, the sequence of the manual setting mode will be described with reference to Fig. 4. The above-mentioned method is set by manual measurement mode in step 2 of Fig. 1 and then called by an argument code value or omission other than the mode selection code input in step 1. Measure the position of the tool from the fold value. To measure the tool position, first, align the main axis to the center of probe 1 axis (X axis in the example shown) using the position value of the measuring device probe set in the device setting mode, and then move to 9a position by manual pulse generator. The length and radius of the tool are calculated from the contact position value when the main axis is moved through the automatic start and the contact position when the probe is in contact with the probe while moving the main axis along the direction of the arrow. Is entered in the tool calibration screen. On the other hand, in order to prevent the interference of the tool by the vice or other jig installed on the CNC equipment table, the tool diameter measurement direction setting factor (Q) and the selected value shown in Table 1 are input together in step 1, Measure the tool diameter in the corresponding direction. That is, in the case of measuring the radius of the tool in any one of 9b to 9e in FIG. 4, the Q factor value corresponding thereto may be input in step 1.

Finally, the process of performing the automatic measurement mode will be described with reference to FIGS. 2, 5, 5A, 5B, and 5C. As described above, the automatic measurement mode is automatically performed before and after cutting by a CNC program. It is programmed so that it can be used to determine the wear and tear of the tool and to correct the tool data. This process will be described with reference to FIG. 2. For the code input in the code input step (step 1), it is determined in step 14 whether it corresponds to the codes illustrated in Tables 1 and 2 as being stored in the storage device, and the reading is performed. If possible, select a measurement method for the input code in addition to the G code (step 15). For example, if any one of values 1 to 4 is input for the Q factor in the measurement direction, a measurement condition corresponding to the value is called and then one position (one position) is measured (step 16). That is, as shown in Table 1, when the Q factor related to the measuring direction is not input, it is set to 1 as the default value, and the direction corresponding to 1, for example, the direction of 16b in FIG. Measure the radius. In contrast, when the measurement direction factor (Q) value is one of 1 to 4, any one corresponding to the input value among the directions indicated by 16b, 16b-1, 16b-2, and 16b-3 in FIG. 5A. Measure the radius of the tool by feeding the spindle so that the tool contacts the probe in the measurement direction of. In contrast, when the measurement direction factor is input to any one of 5 and 6, the radius is measured in two positions, that is, in two directions indicated by 17a and 17b in FIG. 5B or two directions indicated by 17c and 17d, respectively (step 17). . In addition, when the measurement direction factor is input as 7, the radius of the tool is measured in three positions, that is, in three directions indicated by 18a, 18b, and 18c in FIG. 5C. In addition, the process of measuring the radius and length of each tool determines whether the measurement repeat count determined according to the input value of the K value, which is the measurement repeat count setting factor input in step 1, is reached (step 19), and the set measurement repeat count is reached. In this case, since a small measured value may be measured compared to the actual tool by the tool rotation angle, the maximum value among the several measured values is determined as the current tool data, and then compared with the tool data for the same tool before. 20). If the result of the comparison exceeds the tool wear limit range set using the arguments in Table 1, it is determined as a tool break (step 21), and a corresponding shutdown and alarm is generated. In contrast, if it is determined in the tool wear limit range in step 20, it is determined as normal wear (step 22), and the tool data is corrected with the currently measured value (step 24). Further, if the comparison result value in step 20 is out of the tool offset value set using the tool length offset factor shown in Table 1, it is determined as a tool offset error (step 23), and an alarm is generated (step 25).

6 is a graphical user interface (GUI) screen for correcting a measurement delay error according to the selection of the measurement speed factor (F) shown in Table 1, and a linear regression in the interpolation equation according to the measurement value for each measurement speed. The measurement result is added to the measurement algorithm, and the measurement accuracy improvement function is added, and the tool monitoring system can be given the initial value shift amount for the initial error correction.

As described above, the present invention can measure the tool regardless of the tool shape according to the diversification of the used tool, and can reduce tool downtime for tool measurement because the tool data can be corrected according to the wear of the tool even during the process. It offers the advantages of being able to be used by the user.

In addition, it is possible to interpolate the delay error due to the measurement speed to reduce the measurement time required by the high-speed measurement and to improve the precision.

1 is a flow chart showing a tool measurement and calibration process of the machining center according to the present invention,

FIG. 2 is a flowchart illustrating a process of performing the automatic measurement mode of FIG. 1 in more detail.

3 is a diagram illustrating an example of a movement trajectory of a main axis for explaining a three-position measuring process in the process of performing the device setting mode of FIG. 1;

FIG. 4 is a diagram illustrating an example of a movement trajectory of a main axis for explaining a manual position measurement process for a tool in the process of performing the manual measurement mode of FIG. 1;

FIG. 5 is a diagram illustrating an example of a movement trajectory of a main axis for explaining a one-position measuring process in the process of performing the automatic measurement mode of FIG. 2;

5A to 5C are diagrams illustrating an example of a method of selecting a measurement direction in the process of performing the automatic measurement mode of FIG. 2;

6 is a photograph showing an example of a linear regression interpolation program creation screen according to a cutting speed.

Claims (3)

delete delete In the method of measuring and correcting the wear of the tool mounted on the spindle of the machining center, end. Determining whether the code input by the user is a device setting mode, a manual measurement mode, or an automatic measurement mode; I. If it is determined in step A that the code corresponds to the device setting mode, the tool mounted on the spindle of the machining center is brought into contact with the measuring measuring probe mounted on the work table of the machining center at three different places. Measuring the contact position value by moving, and calculating and storing the position value of the measurement measuring device probe from the measured value; All. If it is determined in step A that the cord corresponds to the manual measurement mode, the diameter and length of the tool mounted on the spindle are determined from the position value of the contact point when the tool mounted on the spindle moves to contact the measurement measuring device probe. Calculating at least one of the values and storing the calculated value as tool data; la. If it is determined in the step A that the code corresponds to the automatic measurement mode, the tool mounted on the main shaft is moved from the position value of the contact point when the tool mounted on the main axis is moved by moving the main shaft. Calculate a value of at least one of the diameter and length of, compare the previously calculated value and the previously measured value with respect to at least one of the diameter and the length of the tool mounted on the spindle, and compare the set value of wear range The tool measurement and calibration method of the machining center, characterized in that for correcting and storing the tool measurement information.