JPS63312046A - Tool life detector - Google Patents

Abstract

PURPOSE:To judge simply properly tool life irrespective of cutting requirements by comparing the cutting efficiency of a tool bases on the workpiece cutting amount calculated per unit time and consumed electric power taken for cutting the workpiece with allowable cutting set efficiency. CONSTITUTION:A workpiece cutting amount per unit time calculated by a cutting amount calculating means 5 is obtained on the basis of the feed speed of a spindle 2 and the working shape of a workpiece W and the cutting efficiency of a tool 1 is obtained on the basis of consumed electric power detected by a consumed electric power detecting means 7 for the cutting of a workpiece W. And the life of a tool 1 is constitutionally judged by comparing the cutting efficiency with the allowable cutting efficiency preset by a tool life judging means 10. Thus, even when the feed speed of a spindle 2 is changed in cutting the workpiece W and the working shape is changed by converting the workpiece W, the life of tool 1 can be simply accurately detected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a tool life detection device that detects the sharpness of a tool such as a zeta drill or a lathe to determine its life.

(Prior art) Conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 58-196954, load fluctuations during cutting work, that is, fluctuations in power consumption of the drive motor, are detected, and this value is determined in advance under the same cutting conditions. The presence or absence of a tool abnormality caused by a decrease in the sharpness of the tool, etc. is detected by determining whether or not it is within a set tolerance range. However, in this configuration, since the above-mentioned allowable range is set as a value corresponding to certain cutting conditions, an appropriate determination cannot be made unless the actual cutting operation is performed under the same conditions as the cutting conditions. Therefore, when the feed rate of the spindle and the machining shape of the workpiece change in various ways, it is necessary to set various tolerance ranges in advance that correspond to the cutting conditions, and from within these tolerance ranges, it is necessary to The problem was that the structure of the device was complicated, and the device had to be selected to suit the cutting conditions.

(Object of the Invention) The present invention has been made to solve the above-mentioned problems, and provides a tool life detection device that can easily and appropriately detect the life of a tool regardless of cutting conditions. It is something.

(Structure of the Invention) The tool life detection device according to the present invention includes a feed rate detection means for detecting the feed rate of the spindle, a machining shape manual means for inputting the machining shape of the workpiece, the feed rate detection means and the machining shape manual power. A cutting amount calculating means for calculating the cutting amount of the workpiece per unit time according to an output signal from the means, a power consumption detecting means for detecting the power consumption when cutting the workpiece by the tool, and a cutting amount calculating means for calculating the cutting amount of the workpiece per unit time according to the output signal from the means. a cutting efficiency calculation means for calculating the cutting efficiency of the tool based on the workpiece cutting amount per unit time and the power consumption required for cutting the workpiece determined by the power consumption detection means; A tool life determination means is provided for determining the life of the tool by comparing the cutting efficiency with a preset allowable cutting efficiency.

According to the configuration described above, the cutting efficiency of the tool is determined based on the workpiece cutting amount per unit time calculated by the cutting amount calculation means and the power consumption required for cutting the workpiece detected by the power consumption detection means. By comparing this cutting efficiency with a preset allowable cutting efficiency in the tool life determining means, the tool life can be easily and appropriately determined regardless of the cutting conditions.

(Example) The tool life detection device shown in the drawings includes a feed rate detection means 3 for detecting the feed rate of a spindle 2 having a tool 1 such as a drill attached to its tip, and a tool life detecting means 3 for detecting the feed rate of a spindle 2 having a tool 1 such as a drill attached to the tip thereof, and The machining shape manual means 4 inputs the machining shape of the workpiece W such as the diameter or area of the machining hole, and the workpiece cutting amount per unit time is determined according to the output signals from the feed rate detection means 3 and the machining shape human power means 4. A cutting amount calculation means 5 calculates the amount of workpiece cut per unit time, a power consumption detection means 7 detects the power consumption of the drive motor 6 that rotationally drives the spindle 2, and the amount of workpiece cut per unit time calculated by the cutting amount calculation means 5. The cutting efficiency calculating means 8 calculates the cutting efficiency, that is, the cutting quality of the tool 1 based on the power consumption required for cutting the workpiece determined by the power consumption detecting means 7, and the cutting efficiency t′fjJ calculated by the calculating means 8. averaging means 9 for averaging cutting efficiency values;
By comparing the average value of the cutting efficiency outputted from this averaging means 9 with a preset allowable cutting efficiency, the tool 1
The tool includes tool life determining means 10 for determining the life of the tool. Then, the tool life determining means 10 determines that the average value of the cutting efficiency is smaller than the allowable cutting efficiency, and the tool 1
When it is determined that the life of the control means 1 has expired, the control means 1
A tool change command signal or the like is output to the tool 1 to automatically change the tool 1, or control is executed such as displaying that the life of the tool A1 has expired.

Further, the drive motor 6 detected by the power consumption detection means 7
The detected power consumption value is manually inputted to the comparison means 13 of the feed rate control device 12, and the comparison means 13 compares the detected power consumption value with the allowable power setting value output from the allowable power setting means 14. be compared. and drive motor 6
If it is confirmed that the power consumption exceeds the allowable power, the screw feed mechanism outputs a speed reduction command signal from the feed speed control means 15 and advances the main shaft 2 and the drive motor 6 toward the workpiece W. The drive motor 6 is configured to prevent the drive motor 6 from being overloaded by controlling the rotational speed of the 16 feed motors 17 to be reduced.

In order to determine the life of the tool A1 using the tool life detection device, the feed rate of the main spindle 2 detected during cutting of the workpiece W,
By integrating the machining shape of the workpiece W input in advance, that is, the area of the machined hole, the cutting amount of the workpiece W cut per unit time is calculated in the cutting calculation means 5, and the amount of cutting of the workpiece W is calculated. Drive motor 6 required for
After detecting the power consumption in the power consumption detection means 7,
The cutting efficiency calculation means 8 divides the cutting amount of the workpiece W by the /l″l power consumption of the drive motor 6, thereby calculating the cutting efficiency of the tool 1, which is the ratio of the workpiece cutting amount and the power consumption, for a predetermined period of time. Then, after correcting the detection error etc. by appropriately averaging the calculated value of the cutting efficiency,
By comparing this average value of the cutting efficiency and a preset allowable cutting efficiency in the tool life determining means 10, it is determined whether or not the life of the tool 1 has expired.

That is, when the cutting quality of the tool 1 deteriorates, the cutting resistance of the workpiece W increases, so the power consumption of the drive motor 6 increases, and the feed rate control device 12 operates to increase the speed of the main shaft 2.
The feed rate of the workpiece W decreases, and the amount of cutting of the workpiece W per unit time decreases. As a result, the cutting efficiency calculation means 8
The value of the cutting efficiency calculated in is reduced, and by determining that this cutting efficiency has become smaller than the above-mentioned allowable cutting efficiency, it can be confirmed that the first life of the tool has expired.

In this way, the cutting efficiency of the tool 1 is determined based on the amount of workpiece cut per unit time and the power consumption required for cutting this workpiece, and it is detected that the cutting quality of the tool 1 has deteriorated according to that value. Because the structure is configured to
The life of the tool 1 can be accurately determined without changing the value of the allowable cutting efficiency that serves as a comparison standard. Therefore, the configuration can be simplified compared to a conventional device in which the comparison reference value varies in accordance with changes in cutting conditions.

In addition, in the above embodiment, since the averaging means 9 is provided to appropriately average the calculated values of cutting efficiency, even if the power consumption of the drive motor 6 temporarily increases due to foreign matter getting caught in the machining part, etc. There is also an advantage that false detection can be prevented from occurring.

Note that the above-mentioned cutting efficiency varies depending on the type of tool 1 and the material of the workpiece W, so the cutting efficiency
In a machine tool or the like in which the type of the tool 1 and the material of the workpiece W change, an input means for inputting the type of the tool 1, etc. is provided, and a correction means for correcting the value of the allowable cutting efficiency according to the type of the tool 1, etc. It is desirable to have a structure that provides

Further, a display section is provided to display the cutting efficiency of the tool 1 determined by the cutting efficiency calculation means 8, and the cutting efficiency value displayed on the display section is configured to be used as a guideline for conversion and selection of the tool 1. It's okay.

(Effects of the Invention) As explained above, the present invention calculates the cutting amount of the workpiece based on the feed rate of the spindle and the machining shape of the workpiece, and calculates the cutting amount of the workpiece based on the power consumption required for cutting the workpiece. The cutting efficiency of the tool is determined by division, and the life of the tool is determined by comparing this cutting efficiency with a preset allowable cutting efficiency, so the feed rate of the spindle changes when cutting the workpiece. Further, even when the workpiece is changed and its machining shape changes, there is an advantage that the life of the tool can be easily and accurately detected by comparing the cutting efficiency with a specific allowable cutting efficiency.

[Brief explanation of drawings]

The drawing is a schematic diagram showing an embodiment of the tool life detection device according to the present invention. DESCRIPTION OF SYMBOLS 1... Tool, 2... Spindle, 3... Feed rate detection means, 4... Machining shape input means, 5... Cutting amount calculation means, 7... Power consumption detection means, 8. . . . Cutting efficiency calculation means, 10 . . . Tool life determination means.

Claims (1)

[Claims] 1. A feed rate detection means for detecting the feed rate of the spindle, a machining shape input means for inputting the machining shape of the workpiece, and a workpiece per unit time according to the output signals from the feed rate detection means and the machining shape input means. a cutting amount calculation means for calculating the cutting amount of the tool; a power consumption detection means for detecting the power consumption during cutting of the work by the tool; and a workpiece cutting amount per unit time and power consumption detection means determined by the cutting amount calculation means. A cutting efficiency calculation means that calculates the cutting efficiency of the tool based on the determined power consumption required for cutting the workpiece, and a cutting efficiency calculation means that compares the cutting efficiency of the tool determined by the cutting efficiency calculation means with a preset allowable cutting efficiency. A tool life detection device characterized in that it is provided with a tool life determination means for determining the life of a tool.