KR970007132Y1 - Tool failure/wear detection device by tracking fluctuation of load - Google Patents

Abstract

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Description

Tool breakage / wear detection to track load changes

1 is a graph showing a conventional tool breakage / wear detection method.

2 and 3 are schematic diagrams for explaining a general load change amount

4 is a graph showing a tool breakage / wear detection method according to the present invention

5 is a block diagram showing a tool breakage / wear inspection device according to the present invention

6 is a flow chart showing the operation flow of the tool breakage / wear detection device according to the present invention.

Explanation of symbols on the main parts of the drawings

1: Spindle Servo Unit 2: Tool Breaking / Wear Detection Device

3: NC unit 21: power supply

22: analog-to-digital converter 23: operation panel

24 processor unit 25 input / output unit

The present invention relates to a tool management of a machine tool device. In particular, it tracks the load variation of the spindle and tracks the load variation that can detect wear, breakage and life of the currently used tool. It relates to a tool breakage / wear detection device.

In general, all the tools used in the machine tool have a limited life, and thus may be broken during use. If the tool is broken during use, the workpiece (or material) may be damaged. It is necessary to stop the machine tool in order to make it useless and to replace the tool, and the breakage time cannot be predicted, which makes the work unstable. As shown in FIG. 1, the tool detection criterion and the tool wear reference value and the load of the main shaft were compared with each other to detect damage / wear of the tool.

That is, in FIG. 1, the horizontal axis is roughly divided into the "axis on", "cutting", "non-cutting", "cutting", and "spindle off" periods as the time axis, and the vertical axis is the load of the spindle (SPINDLE). (LOAD) indicates that the load rises rapidly at the time of "spindle on" and then falls to the unprocessed level, and the load is greater than that at the time of cutting (CUTTING START & END), and when the "spindle off", The load is applied and then drops to 0. During cutting, the tool status is monitored and when the load exceeds the set tool wear threshold, a tool wear signal is generated and sent to the controller of the machine tool device. When exceeding, the tool breakage signal is generated and transmitted to the controller of the machine tool. The machine tool inputs the tool wear signal or the tool breakage signal of the tool wear / damage detection device to determine the state of the tool. By and thereby is controlled so that the selection as to stop the machine tool apparatus or the replacement tool and improved machining efficiency.

However, in the conventional tool breakage / wear detection method as shown in FIG. 1, since the tool break reference level and the tool wear reference level are constant regardless of load variation, a material having different hardness or cutting amount with one tool When machining the surface of the tool, the wear and breakage of the tool is set based on a high load amount, there was a problem that can not accurately detect the wear and breakage of the tool.

That is, in the case of a CNC lathe, almost all processing is performed in the constant speed constant control (G96) mode, and as shown in FIGS. 2 to 3, the "perverse speed constant control" means a tool 14 per section. This means that the retention time should be constant, so that the larger the radius of the workpiece 12, the slower the rotational speed of the spindle 10, and the smaller the radius of the workpiece 12, the faster the rotational speed of the spindle 10, accordingly The load amount in (10) is also severely changed, and according to the material (i.e., workpiece 12) as shown in FIG. 3, the respective cutting amount and the machining direction and the hardness of each side of A, B, C, D Due to the large change in the state and the like, the fluctuation of the load is severe. Therefore, the state of the tool cannot be accurately detected by the conventional tool wear / damage detection method due to the fluctuation of the load.

In order to solve the above-mentioned problems, the present invention tracks a change in load to change a tool wear and a breakage reference level, thereby accurately detecting breakage and wear of the tool, thereby improving the operation rate of the machine tool. The purpose is to provide a damage / wear detection device.

In order to achieve the above object, the tool breakage / wear detection device of the present invention is a tool breakage of a factory machinery that detects the state of a tool by inputting a load value from a spindle servo unit according to an operator's key input and outputs it to the NC unit. In the wear detection device,

An analog-digital converter for converting the load value into digital; and

An operation panel which displays a state of a tool and inputs an operator's key;

According to the key input of the operation panel, the change of the load value is tracked in the sampling mode to preset the tool wear and tool breakage reference level, and the tool wear and damage reference value is compared with the digitally converted load value in the machining mode. And a processor unit generating a damage signal. And

And an input / output unit for transmitting the tool wear and damage signal to the NC unit to interface the processor unit and the NC unit.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The tool breakage / wear detection apparatus according to the present invention samples the variation of load at a predetermined sampling period (for example, 200 ms) while processing the sample material according to the corresponding machining program in the sampling mode as shown in FIG. The tool wear reference value and the tool break reference value are set as a percentage of the stored sampling value (for example, the tool wear reference value is 120% of the sampling value and the tool damage reference value is equal to 130% of the sampling value). It can be seen that the set reference values (tool wear reference value, tool damage reference value) change together with the change of load from the end to the end.

The apparatus of the present invention having such characteristics is connected to the spindle servo unit 1 for driving the spindle and detecting the load and the NC unit 3 for controlling the operation of the machine tool device as shown in FIG. A power supply device 21 for inputting AC power to supply DC power to each block; An analog-to-digital converter 22 for inputting a load value from the spindle servo unit 1 to digital conversion; An operation panel 23 which displays a state of a tool and inputs an operator's key; According to the key input of the operation panel 23, the change of the load value is tracked in the sampling mode to preset the tool wear and tool breakage reference levels, and the tool wear and breakage reference values set in the machining mode are compared with the digitally converted load values. Processor 24 for generating a tool wear and breakage signal; And an input / output unit 25 for transmitting the tool wear and damage signal to the NC unit 3 to interface the processor unit 24 with the NC unit 3.

The operation of the apparatus of the present invention configured as described above will be described in detail with reference to the flowchart of FIG. 6.

6 is a flowchart showing the flow of operation of the device of the present invention, in which the first to fourth steps are sampling modes for setting tool breakage / wear thresholds for tracking the change in load, and the fifth to twelfth steps. Is a machining mode that detects breakage / wear of a tool by comparing the set breakage / wear reference value with the actual load value.

Subsequently, the operation of each mode will be described. In the first step S1 of the sampling mode, after mounting the sample material to be processed, the operation mode 23 selects the sample mode,

In the second step S2, the cycle CYCLE of the part program is performed to store the sample value in the memory,

In the third step (S3) to check whether there is another sample material, if there is another sample material, replace it with the corresponding sample material, go back to the second step and repeat all the sample materials in the fourth step (S4) Release the sample mode.

As described above, all data according to the load value change is stored for each sample material to be processed in the sample mode, and the reference value is easily set because the tool wear or breakage reference value is set as a percentage (%) to the stored load value.

Subsequently, in the machining mode, the fifth step (S5) is equipped with the material to be processed corresponding to the sample material to perform a cycle of machining program

In the sixth step S6, if the load value generated during the fifth step is analog-to-digital converted, and there is no problem compared with the tool breakage and wear reference values set in the sampling mode, the fifth step S5 is continued. In step S7, if the threshold value is exceeded, it is determined whether wear or damage occurs.

At this time, if the wear threshold value is exceeded but the damage threshold value is not reached, it is judged as "wear" and the "tool wear signal" is generated in the eighth step to display an alarm on the operation panel 23 and the tool wear signal to the NC unit 3. Send,

If the damage threshold value is exceeded, it is determined as "breakage", and a tool breakage signal is generated in the ninth step S9 to display a corresponding alarm on the operation panel 23, and transmit the tool breakage signal to the NC unit 3.

In the tenth step S10, the NC unit 3 controls the machine tool in accordance with the tool wear signal to command another tool number (TOOL NO.) To replace the currently used tool, and in the eleventh step S11. After disabling the alarm in step 5, the process returns to the fifth step S5 to continue the machining cycle with the replaced tool.

In the twelfth step S12, the NC unit 3 controls the machine tool in accordance with the tool breakdown signal to terminate the machining cycle, stop the spindle, and replace the broken tool.

As described above, the present invention is used for tool management of a machine tool, and after setting the tool breakage or wear reference data that tracks the load variation from data according to the load variation of the sample material in the sampling mode, By detecting the state of the tool according to the set reference data, it can accurately detect the breakage or wear of the tool according to the load fluctuation, improve the operation rate of the machine tool device, and improve the processing quality by reducing the defective rate by managing the tool efficiently. It can be effective.

Claims (1)

In a tool breakage / wear detection device of a machine tool device that inputs a load value from a spindle servo unit (1) according to an operator's key, detects the state of a tool, and outputs it to the NC unit (3). An analog-to-digital converter 22 for inputting the load value and converting it into digital; and An operation panel 23 for displaying a state of a tool and inputting an operator's key; According to the key input of the operation panel 23, the change of the load value is tracked in the sampling mode to preset the tool wear and the tool breakage reference level, and the set tool wear and breakage reference value and the digitally converted load value in the machining mode are preset. A processor unit 24 for generating tool wear and breakage signals in comparison; And And an input / output unit (25) for transmitting the tool wear and damage signal to the NC unit (3) to interface the processor unit (24) with the NC unit (3).