SU512045A1 - Device for controlling a centerless grinding machine - Google Patents

Description

one

The invention relates to the field of machine tools.

Devices for controlling metal cutting machines are known in which the energy parameters of the drive motor are used as a sensor signal of the control system.

The purpose of the invention is to improve the accuracy of processing.

This is achieved by the fact that the motor grinds, its range is switched on via a current transformer installed in the linear power supply wire, and through a step-down phase voltage transformer logarithmic converters, to the outputs of which permanent resistors are connected in such a way that the voltage drops on them are added, and oppositely, they are connected to a voltage dependent on the magnitude of the supply, and the resistors are connected to the input of a phase-sensitive amplifier operating at a carrier frequency, to the output of which a control is connected The winding of the magnetic amplifier filters, tuned by frequencies, proportional to the speed of the driving and grinding wheels, amplifiers are connected to the output of the filters, and the relay coils are connected to their outputs, the executive contacts of which are connected in parallel with the button connected in series with the actuator coil

the engine of the accelerated withdrawal of the grandma in the circle around back.

The invention is illustrated in the drawing.

The device contains an electric motor 1 drive grinding wheel 2 with the editing mechanism 3; direct current motor 4 for driving a drive circle 5 with straightening mechanism 6; transformers 7 and 8 of current and voltage connected to logarithmic converters 9 and 10 of current and voltage channels; a drive wheel speed control system, selective measuring channels, a grinding head movement control system.

Claims (1)

The drive circle engine speed control system includes an electric motor 4 with a shunt excitation winding 11, a magnetic amplifier 12 with control windings 13 and a bias 14 connected to the engine circuit 4, a phase-sensitive amplifier 15 loaded on the control winding 13, whose input is connected to a comparison circuit made up of load resistors 16 and 17 of logarithmic converters of a current channel and voltage, connected according to, and a resistor 18 of a setting circuit consisting of a power source 19, an indicator 20 and an adjustable resistor 21 connected in such a way that the voltage from the HSCTOpa 18 compensates for the voltage allocated to the resistors 16 and 17. The selective measuring channels include filters 22 and 23 tuned to frequencies proportional to the number of revolutions of the grinding and driving wheels connected to amplifiers 24 and 25, indicators 26 and 27 of the power increment of the motors of the skimming and driving circles are connected to the outputs of the amplifiers, and also coils of actuating relays 30, 31 of the diversion control are connected through variable resistors 28 and 29 grandmother. The grinding head movement control system, having a position indicator 32, consists of an AC electric motor 33 activated by contacts of a magnetic starter 34, the coil of which is turned on by a button 35 and in parallel connected normally open contacts 36 and 37 of executive relays 30, 31. The device also contains a power supply unit 38 electric motors. The device works as follows. When the machine is turned on, a voltage is applied to the control circuit and power circuits. When the pressure in the lubrication system reaches the desired value, the electric motors 4, 1 of the driving 5 and 2 of the grinding circles are turned on. The part is fed into the clicked-through area through the guide bars, the longitudinal feed and rotation of which is carried out during the grinding process by rotating the drive wheel 5. Using the setting power of the base power, the base power of grinding is indicated by the indicator 20, which is indicated by the absence of signals on the indicators 26 and 27 In this case, the signals taken from transformers 7 and 8 are fed to the inputs of logarithmic converters 9 and 10, are summed on resistors 16 and 17, and the resulting sum of voltages is subtracted from the voltage obtained of the resistor 18. If the voltage across the resistor 18 is equal to voltage across the resistors 16, 17, the indicators 26 and 27 indicate zero. As the grinding wheel becomes blunt, the power consumed for grinding increases, which leads to the appearance of voltage at the input of the amplifier 15 and the appearance of current in the winding 13. An increase in the current in the control winding reduces the voltage at the output of the magnetic winding. an amplifier, which lowers the rotational speed of the rotor of the electric motor 4 of the driving wheel 5 within the required limits. In the event of a Part in the grinding zone with a smaller allowance relative to the batch of parts, the power of the electric motor 1 decreases, and the system increases the speed of the drive wheel. Similar operation of the machine in the specified modes stabilizes the quality of the surface to be treated under the specified grinding conditions. Upon further dulling of the circle, its geometry is disturbed, which leads to a beating. At the output of the amplifier 15, voltage fluctuations appear with frequencies proportional to the speeds of rotation of the clamping 2 and the driving 5 circles. Frequency signals are extracted using filters 22 and 23, amplified by amplifiers 24 and 25; The signal level is controlled by indicators, the scales of which are calibrated as a percentage of the increment of the vibrational power. If the amplitude of the signals reaches a critical value set by resistors 28 and 29 and by changing the gain of the amplifiers 24 and 25, relays 30 or 31 are triggered, which, by contacts 36 and 37, turn on the magnetic starter 34, the drive head motor 33 switches off, the grinding process stops and the corresponding circle is edited. The invention is a device for controlling a centerless grinding machine, having individual drive motors of the driving and grinding wheels, as well as a wheelhead displacement engine, and a current process power measurement unit, including current transformers and voltages, connected to the power circuit of the grinding wheel engine with an executive relay, and a unit for deducting the initial power, and the driving circle motor is powered by a magnetic amplifier, characterized in that, in order to increase processing accuracy, summing resistors connected to current and voltage transformers through logarithmic converters are introduced into the device, and a setpoint of initial power values is connected to counter summing resistors, and the specified resistors are connected to the executive relay through the phase-sensitive amplifier and frequency filters, and to the output of the phase-sensitive amplifier The control winding of the magnetic amplifier is connected. .28 S J: UliuuiuiiiuuJf; i 32