JPH0223406A - Nc machine tool adaptive control device - Google Patents

Abstract

PURPOSE:To surely make the measured data of respective types of the measurement item close to a target value and to attain the smooth working by comparing the measured data, the target value and an allowable value and outputting the working conditions corresponding to the minimum allowable value out of the allowable value in which the measured data enter the range, as optimum working conditions to the NC machine tool. CONSTITUTION:Measured data such as a cutting force, a spindle torque, material, the condition of a tool and the contacting position of the tool and the workpiece and the measured data such as the temperature and the dimension, shape and surface roughness are inputted from an NC machine tool 10 side to an input part 12. From these measured data and the target value, allowable value, working conditions, etc., of respective types of the measurement item of a recording part 14, optimum working conditions are obtained by an arithmetic part 13. During the working work the operation is continuously executed and the optimum working conditions are outputted hourly. Thus, the measured data of respective types of the measurement item can be surely close to the target value, the change of the working conditions is small and the smooth working work can be performed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides an NC machine tool with optimum processing conditions to reliably and quickly obtain measurement data of various measurement items that indicate the processing state of a workpiece. The present invention relates to an NC machine tool adaptive control device that can approach a target value.

(Prior Art) Conventionally, the following methods are known as adaptive control methods applied to NC machine tools.

(1) Measure various measurement items that indicate the workpiece machining status, such as cutting force and spindle torque, and determine machining conditions such as cutting speed so that these measured data fall within the tolerance range for the target value.

(2) Measure tool wear, tool life, etc., and replace tools at appropriate times.

(3) Measure the dimensions and shape of the workpiece and process while correcting errors.

Furthermore, in these adaptive control methods, a feedback loop is generally formed and controlled for one measurement item. In other words, for example, when cutting force among measurement items is set to a certain target value, machining conditions such as cutting speed are input to the NC machine tool so that the measurement data of only this cutting force falls within the range of allowable values for the target value. are doing.

(Problems to be Solved by the Invention) As described above, in the conventional NC machine tool control method, a feedback loop is generally formed to control one measurement item.

However, what is required in actual machining work is to determine target values for a plurality of measurement items, and to find optimal machining conditions such that the measured data approaches the target values. For this reason, in practice, workers listen to the motor sounds of NC machine tools, measure the dimensions of workpieces, monitor finishing conditions, and check the cutting edge condition of tools. The above-mentioned optimal processing conditions have been determined based on the know-how of

It is said that the reason why conventional adaptive control methods can only control one measurement item is because the logic becomes complicated when determining optimal processing conditions for a plurality of measurement items.

The present invention has been made in consideration of these points,
It is an object of the present invention to provide an NC machine tool adaptive control device that can quickly and reliably bring measurement data of a plurality of measurement items close to target values by utilizing the know-how gained through the experience of a worker.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an input section into which measurement data of various measurement items indicating the processing state of a workpiece is input, target values of the various measurement items, and a target value that increases sequentially with respect to the target value. a recording section in which the set tolerance values are recorded, as well as processing conditions set so as to bring the measurement data of the measurement item closer to the target value in correspondence with these target values and tolerance values; a calculation unit that compares the measurement data from the storage unit with the target value and tolerance value from the recording unit, and calculates a machining condition corresponding to the minimum tolerance value among the tolerance values within which the measurement data falls within the range as the optimum machining condition; , and an output section for outputting the optimum machining conditions determined by the calculation section to the NC machine tool.

(Function) According to the present invention, the calculation unit compares the measurement data from the input unit with the target value and tolerance value from the recording unit, and corresponds to the minimum tolerance value among the tolerance values within which the measurement data falls within the range. The machining conditions to be used are the optimal machining conditions, and these optimal machining conditions are output to the NC machine tool via the output section, making it possible to reliably bring the measurement data of various measurement items close to the target values.
In addition, it is possible to perform smooth machining work by minimizing changes in machining conditions.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 3 are diagrams showing an embodiment of the NC machine tool adaptive control device according to the present invention.

In FIG. 2, the NC machine tool 10 is a machine tool main body 20.
and an NC control device 22 that controls the machining operation of the workpiece by the machine tool main body 20.

The NC control device 22 also includes an NC machine tool adaptive control device 11 that inputs optimum machining conditions into the NC control device 22.
is connected.

Furthermore, the machine tool main body 20 is provided with a temperature sensor 23 and a three-dimensional measuring device 24 for measuring the dimensions and shape of the workpiece.
C is connected to the machine tool adaptive control device 11.

Further, the NC control device 22 outputs total nl data of various measurement items, such as cutting force and spindle torque, to the NC machine tool adaptive control device 11.

Next, the NC machine tool adaptive control device 11 will be explained in detail with reference to FIG.

The NC machine tool adaptive control device 11 includes an input unit 12 into which measurement data of various measurement items indicating the machining state of the workpiece is input.
, a recording section 14 in which target values and tolerance values of various measurement items, and processing conditions set corresponding to these target values and tolerance values are recorded; and measurement data from the input section 12 and recording section 14. a calculation unit 13 that calculates the optimum machining conditions by comparing the target values and tolerance values of 15.

Next, the recorded contents in the recording section 14 will be explained with reference to FIG.

As shown in FIG. 3, target values are determined in advance for various measurement items such as cutting force and spindle torque, and allowable values that are set to increase sequentially with respect to the target values are recorded.

This tolerance value is set as follows.

For example, if the target value of cutting force is set as 20, the allowable value is ±1. ±2. ... and then set it to increase in size.

Next, corresponding to these target values and each allowable value, processing conditions are set and recorded so that the measurement data of the measurement item approaches the target value.

In other words, if the measurement data is within the tolerance range for the target values of various measurement items shown in the left column of Figure 3, if the processing conditions in the right column are followed, the measurement data will approach the target value (
convergence).

Here, one horizontal line in FIG. 3 is called a rule.

The target values and allowable values of the various measurement items shown in FIG. 3 and the processing conditions corresponding thereto have been determined through experience based on the know-how of the operator. Moreover, the recorded contents shown in FIG. 3 are recorded for each target value of various measurement items.

Next, the operation of this embodiment having such a configuration will be explained.

First, various totals n1 are input from the NC machine tool 10 side to the input section 12.
Measurement data for the item is input.

In this case, the NC control device 22 of the NC machine tool 10 sends information such as cutting force, spindle torque, material compared with NC data, tool wear, tool breakage, tool abnormal vibration, contact position of the tool and workpiece, etc. Measurement data is input. Furthermore, measurement data such as outside air temperature and workpiece temperature are input manually from the temperature sensor 23 of the NC machine tool 10. Furthermore, N
Measurement data such as the dimensions, shape, and surface roughness of the workpiece are input from the three-dimensional measuring device 24 of the C machine tool 10.

Subsequently, the optimum machining conditions are calculated in the calculation section 13 from the measurement data from the input section 12 and the contents recorded in the recording section 14, that is, the target values, tolerance values, machining conditions, etc. of various measurement items.

The calculation in the calculation section 13 is performed as follows.

(1) First, select a rule in which the measurement data falls within the range of allowable values set for the target value of each measurement item.

(2) Next, among the rules selected in item (1), the rule with the smallest allowable value is set as the optimal rule, and the machining conditions of this rule are determined as the optimal machining conditions.

(3) If there is no applicable rule in (1), do not process and leave the processing conditions to the operator.

For example, in Fig. 3, if the rules selected in section (1) are Rule 3, Rule 4, Rule 5, etc., Rule 3 with the smallest allowable value is considered the optimal rule, and the processing conditions for Rule 3 are Optimum processing conditions.

Subsequently, the optimum machining conditions determined by the calculation unit 13 are output to the output unit 15.
The results are then output to the NC control device 22, and machining work is performed by the NC machine tool 10 based on these optimal machining conditions.

The arithmetic operation in the arithmetic section 13 described above is performed continuously during the machining operation, so that the NC control device 221 outputs new optimum machining conditions every moment.

By outputting the optimum machining conditions to the NC control device 22 and performing the machining work in this way, the measurement data of various measurement items can be reliably brought close to the target values. In addition, by setting the machining conditions of the rule with the smallest allowable value as the optimum machining conditions, changes in the machining conditions can be reduced and smooth machining work can be performed.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reliably bring the total nj data of the 11 items of various ri closer to the target value, and it is also possible to perform smooth machining work by minimizing changes in machining conditions. Therefore, stable and reliable machining work can be performed without relying on the experiential know-how of workers as in the past.

[Brief explanation of the drawing]

1 to 3 are diagrams showing one embodiment of the NC machine tool adaptive control device according to the present invention, FIG. 1 is an overall system diagram of the NC machine tool adaptive control device, and FIG. 2 is a diagram showing the NC machine tool and FIG. 3 is an overall schematic diagram showing the NC machine tool adaptive control device, and is a diagram showing the recorded contents in the recording section. DESCRIPTION OF SYMBOLS 10... NC machine tool, 11... NC machine tool adaptive control device, 12... Input part, 13... Arithmetic part, 14
... Recording section, 15... Output section. Applicant's agent Mr. Sato

Claims (1)

[Claims] An input section into which measurement data of various measurement items indicating the processing state of the workpiece is input, and target values of various measurement items and tolerance values set to increase sequentially with respect to the target values are recorded. a recording section in which machining conditions set to bring measurement data of a measurement item closer to the target value in accordance with the target value and tolerance value are recorded; and measurement data from the input section and target values from the recording section. and tolerance values, and calculates the machining conditions corresponding to the minimum tolerance value as the optimum machining conditions among the tolerance values within which the measurement data falls within the range. An appropriate control device for an NC machine tool equipped with an output section for outputting to the machine.