SU1215943A1 - Apparatus for automatic running adjustment and wear monitoring of cutting tool - Google Patents

Description

The invention relates to the automation of mechanical engineering, in particular, to devices for monitoring the state of the cutting tool during machining, and can be used in machining on turning, revolving and other machine tools.

The aim of the invention is to increase reliability by simplifying the device. The drawing shows a diagram of the device.

The device includes a cutting temperature sensor 1, a differentiation unit 2, the input of which is connected to the output of the sensor 1 through an aglazhivayuschiy filter 3, and the output to the input of an amplifier 4 with an adjustable gain / C ratio by the first input of the adder 5, the integration unit 6 integrating the drive), the input of which is connected to the output of the amplifier 4, and the output to the tool-wear compensation mechanism 7 (built on the basis of a typical proportional link) and to the input of the first threshold element 8; memory trigger 9, the input of which is connected to the output of the threshold element 8, and the output through the key circuit 10 - to the input of the tool-change mechanism 11, the second and third threshold elements 12 and 13, whose inputs are connected to the output of the adder 5, and the outputs through the inverter 14 and the logic element OR 15 is connected to the alarm indicator of catastrophic wear (breakage or thermal fit) of tool 16 (it is either a signal lamp or a siren in combination with a relay that turns off the machine’s feed drive).

The device works as follows. First, the threshold elements 8.12 and 13 of the adder 5 are adjusted. To do this, the threshold element 8 is set to the response threshold corresponding to the maximum allowable tool wear, the adder 5 through the second input B sends a signal exceeding the threshold of the element 8 approximately 1.5 times element 12 is adjusted to the trigger threshold lower than the level of the signal applied to input B by about 10%, and element 13 is adjusted to the trigger threshold exceeding the level of the signal fed to input B to 30-40%. When the device is in operation, the cutting temperature sensor 1 generates a signal whose value has a constant component caused by the cutting conditions, the material of the tool and part, and the tool geometry, as well as the variable component caused by the tool wear. Pass through filter 3, smoothing out random oscillations of the signal, and block 2, calculating its derivative, sigVNIIPI Order 940/16 Circulation 826 Subscription Branch PPP "Patent, Uzhgorod, ul. Project, 4

The signal from sensor 1 is converted to a signal whose value is proportional to the intensity of tool wear under these machining conditions. The signal from block 2 is massaged in amplifier 4 in accordance with the gain / C, equal to the sensitivity of sensor 1 under the given processing conditions, and is integrated by block 6. As a result, the output of block 6 produces a signal proportional to

tool wear since system start up. This signal is fed to the wear compensation mechanism 7, which corrects the position of the tool in accordance with the wear. If the magnitude of the signal at the output of block 6 exceeds the threshold of operation of element 8, which corresponds to the excess of the maximum allowable wear of the tool, then the output of element 8 results in a signal that is remembered by trigger 9. At command A, the processing loop control device (not shown) The key 10 after the completion of machining the signal from trigger 9 will pass to the tool changing mechanism 11, which will replace the worn tool with a new one.

This is how the system works with normal tool wear. At the same time, at the output of block 2, the signal is constant, at the output of adder 5, too, threshold element 12 is turned on, element 13 is turned off, element 15 and the signaling device 16 do not receive signals.

In the case of a tool breakdown (catastrophic wear), the system works differently. First of all, there is either a sharp increase in the signal level at the output of block 2, or a decrease.

In the first case, the threshold element 13 is triggered and generates a signal that, passing through the OR element, turns on the alarm 16, which gives a light or sound signal and turns off the machine feed drive. In the second case, the element 13 does not change the state, but the element 12 is triggered. This is expressed in the disappearance of the signal at its output, which is converted by the inverter 14 into the appearance of a signal at the input of the signaling device 16. The latter works the same as in the first case.

The system works the same way when processing cylindrical, and when machining fittings. The only difference is that during machining of shaped parts, for example, on a computer-controlled machine tool, the value of / C should also be changed according to the program. The change must be made according to experimental dependencies that establish the relationship between the magnitude A and the cutting modes and the actual geometry of the tool.

Claims (1)

DEVICE FOR AUTOMATIC ADJUSTMENT AND CONTROL OF WEAR OF CUTTING TOOLS, comprising a wear sensor associated with a wear compensation mechanism and a tool change mechanism, characterized in that, in order to increase reliability, a series-smoothing filter connected between the wear sensor and the wear compensation mechanism is connected , a differentiation unit, an amplifier with adjustable gain and an integration unit, between the integration unit and the tool replacement mechanism, connected sequentially the first threshold element, trigger and key, and the output of the differentiation unit is connected to the inputted adder, the output of which is connected to the inputted second and third threshold elements connected in parallel, the output of the second threshold element is connected to the input logical element NOT, the output of the third threshold element is connected to the input logical OR element, the second input of which is connected with the logical element NOT, and the output - with the entered indicator of catastrophic wear. Yu SI ς © CO>