JPS5942249A - Correcting method of machining diameter - Google Patents

Abstract

PURPOSE:To enable to machine with high accuracy and to measure and correct automatically, by a method wherein a machining diameter accompanied by machining at each cutting stroke is measured, the measured value is compared with a designed value, and the tool is corrected a plurality of times by the output. while a correction quantity for a tool is outputted. CONSTITUTION:In an automatic machining correcting system in a balling on a machine tool or the like, after machining by an adjustable-type balling unit 4, the machining diameter is measured by a measuring probe 5. The data thus obtained are converted into a measured value of machining diameter by a measurement controller 6. A correcting calculator 7 compares the thus obtained value with an expected value (preset depth of cut), and calculates a correction quantity for the subsequent cutting stroke of the unit 4. Based on the correction quantity, a correcting controller 9 drives a correcting driving unit 10 to set the dimensions of the unit 4. Accordingly, it is enabled to machine with high accuracy and to measure and perform correction automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic machining diameter correction method in polling machining and the like on a machining machine.

Conventionally, the automatic machining diameter correction method in polling machining is
The inner diameter of the machined workpiece is automatically measured, the cutting edge position of the tool is automatically adjusted to the optimal position based on this measurement value, and the next workpiece in the order is machined using this corrected tool.
In other words, a so-called post-processing method is adopted in which the next workpiece is machined based on the previous workpiece machining.

However, with this post-processing method, if there is a margin in the target machining tolerance, it is possible to maintain machining accuracy within the predetermined tolerance by repeating the above-mentioned correction within the range that does not exceed the machining tolerance. However, if there is no margin for machining tolerance and the machining accuracy is high, it has the disadvantage that the required accuracy cannot be maintained with a single correction operation.

Therefore, in view of the above-mentioned drawbacks, the present invention aims to provide a machining diameter correction method that reliably obtains machining accuracy even in high-precision machining with a narrow machining tolerance.

The present invention achieves this object by setting the number of cuts a plurality of times to cut a workpiece, and after setting the number of cuts and the amount of cut per each cut in advance,
Measure the machining diameter associated with the machining of each cutting cycle above, compare this measured value with the predicted value set above in advance, output the tool correction amount, use this output to correct the tool, and use it for the next cutting cycle. The present invention is characterized in that the advancing depth of cut measurement correction operation is repeated the number of times described above.

Embodiments of the present invention will now be described with reference to FIGS. 1 to 3. FIG. 1 shows an example of a configuration used for the method of this embodiment. After machining the workpiece 1 using a boring tool 3 that rotates with the rotation of the spindle 2 and an adjustable boring unit 4, the machining diameter is measured using a measurement probe 5. The data obtained by this measurement is processed by the measurement control device 6 into a measured value of the machining diameter. This measured value is calculated by the correction calculation device 7.
The amount of correction for the next depth of cut of the adjustable boring unit 4 is calculated by comparing it with the predicted value, which is the depth of cut set in advance. This correction amount is output to the printer 8 and also to the correction control device 9. Correction control device 9
sets the dimensions of the adjustable boring unit 4 by driving the correction drive unit 10 based on the correction.

The above operation is performed a preset number of times in the program, and the next depth of cut is automatically corrected. Therefore, trial cutting is performed with a tool adjusted to a size smaller than the desired machining diameter, this machining diameter is automatically measured, and the position of the tool for the next cut is automatically corrected based on this data. Cutting is performed with a new tool position, measurement is performed, and so on, and this process is repeated over multiple cycles to perform high-precision boring processing. In this case, corrective cutting is performed multiple times on the same workpiece, resulting in so-called in-process machining. In addition, when measuring the machining diameter in FIG. 1, a highly accurate measurement result can be obtained by performing relative measurement with the ring cage 11.

FIG. 2 is a flowchart of this repetitive processing procedure. When START is pressed, the number of corrections and the initial depth of cut are printed out, and the machining program is started. After the first cutting, the machined diameter is automatically measured, this value is printed out, and the correction amount is calculated with reference to the predicted value. If the number of corrections is still less than the number of times, the tool diameter is corrected using the data obtained by calculating the correction amount. Next, a second cutting is performed using the corrected new tool diameter according to the machining program, and the above-described procedure is repeated. When a preset number of corrections is reached after a plurality of corrections, the measured value of the machining diameter is printed out, the tool correction is returned to zero, and the cutting process on the workpiece is completed. In this way, the workpiece is cut by repeating machining → measurement → prediction → adjustment → machining.

Figure 3 shows the predicted depth of cut of the workpiece in an example of three-time machining, where machining diameter D1 is the first machining, machining diameter D2, D3
is the amount cut in the second and third machining. In actual machining, for example, if the machining diameter D1 is obtained in the first machining as shown in Figure 4, the difference δ5 between the machining diameter D4 and the target machining diameter D1 is the cutting correction amount of the tool. ,
Based on this cutting depth correction amount, the tool is corrected in consideration of the next cutting depth δ6, and machining is performed with the next cutting depth δ6. This method is repeated for the number of cuts initially set (in this case, the number of cuts is three, and the correction is twice).

As explained above, according to the present invention, high-precision machining is possible by performing tool correction multiple times.In particular, in the past, measurement and correction after machining took a lot of time, but with the present invention, automatic measurement is possible.・Compensation is now possible, and the tool position is set by repeating the correction after trial cutting with undersize, so the predetermined machining accuracy can be obtained. Furthermore, when tools are automatically replaced by an automatic tool changer, the replacement errors that adversely affect machining accuracy can be eliminated by tool correction.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the machining diameter correction method according to the present invention, and FIG. 1 is a configuration diagram for explaining the method of this embodiment,
FIG. 2 is a flowchart, and FIGS. 3 and 4 are explanatory diagrams showing the difference between the set value and the actual value of the machining diameter of the workpiece, respectively. In the drawings, 1 is a workpiece, 4 is an adjustable boring tool, 6 is a measurement control device, 7 is a correction calculation device, 9 is a correction control device, and 10 is a correction drive unit.

Claims (1)

[Claims] When cutting a workpiece by setting the number of cuts multiple times, after setting the number of cuts and the amount of cut per each cut in advance, the machining diameter associated with the machining of each number of cuts is set. The measured value is compared with the predicted value set in advance, and the tool correction amount is output. The tool is corrected based on this output. The depth of cut measurement correction operation proceeds to the next cutting time. The machining diameter correction method is repeated.