SU942946A1 - Apparatus for automatic setting of feed of profiling machine - Google Patents

Description

(54) DEVICE FOR AUTOMATIC CONTROL

PRESENTING COPYING

one

This invention relates to automatic control of metal cutting machines and is intended for use on copy milling and copy grinding machines.

Devices are known for automatically controlling a master feed of a copying machine, comprising a meter of an error module of a tracking system whose input is the first input of the device, an error tolerant error setting device, a first matching element, inputs of which are connected to an error modulus output module and an error error setting generator, connected to the output of the first comparing element, an error regulator, a measuring transducer of the active power of the main motion engine, whose input is a second input device, the power setpoint and second comparing element whose inputs are connected to the outputs of the sensor 1 and the set point power.

A disadvantage of such devices is the low quality control of the tracking system, which reduces the processing accuracy.

MACHINE

The purpose of the invention is to improve the quality of control of the two output parameters of the copying process by organizing independent control loops.

This goal is achieved by introducing a logic device, a switch and a power controller, the input of which is connected to the output of the second comparing element and the output to one of the inputs of the switch, the other two inputs of which are connected to the outputs of the error controller and logic device. The inputs of the latter are connected to the outputs of the first and second matching elements, and 5 the output of the switch is the output of the device.

The drawing shows a block diagram of the proposed device.

The device 1 for automatically controlling the master feed of the copying machine (CS) 2 contains an error meter module (IMO) 3 of the tracking system, the input of which is the first input of the device, the setting unit 4 of the allowable error value (30) of the tracking system, the first matching element ( SE1) 5, the inputs of which are connected to the outputs IMO 3 and AO 4, connected to the output of the SE1, error controller 6 (PO), measuring transducer 7 of active power (IPM) of the main motion engine, whose input is the second input of the device, unit 8 power the second comparing element (СЭ2) 9, the inputs of which are connected to the outputs of the ЗМ and ИПМ, as well as additionally introduced power regulator 10 (РМ) connected by its input to the exit СЭ2 9, connected to the outputs СЭ1 5 and The SE2 9 logical device (LU) 11 and the switch (K) 12, the output of which is the output of the device, and the inputs are connected to the outputs of the LU II, PO 6 and PM 10. The device operates as follows. In the process of copying, it provides two modes of control of the drive of the master feed (PZP) KS 2: the mode of limiting the error of the following system and the mode of stabilization of cutting forces. In the mode of limiting the error of the servo system, the RO 6 is connected to the PPP input through K 12. This forms a closed control circuit consisting of a PPP, a follower of the copying machine, IMO 3, SE1 5, PO 6, and K 12. Occurs during processing The IMO 3 is perceived as the profile of the error of the working system. In accordance with the difference between the measured value of the error and its allowable value specified 30, which is formed at the output of the solar cell 1, the RO generates a control action on the LAR, which changes the target feed, and all dstvie varies and this error value power servo system. Consequently, the function of this control loop is reduced to maintaining the specified error value for tracking the copier profile, which, with small errors, in areas with a constant copy size leads to an increase in processing efficiency, and in transitions, it helps to limit the copying error and improve processing accuracy. In the mode of stabilizing the cutting forces, the PM 10 is connected to the input of the adjustable drive of the driving feed. Through the K 12, a closed control loop is formed, consisting of the PPP, the main drive engine, IPM, SE2 and PM. The active power consumed by the motor of the main movement from the electrical network is measured by means of IPM. DC signal proportional to the measured power. after subtracting the idle power, it is fed to the MNS 9, the output of which forms the difference between the actual power value and the reference level set by the ZM. This difference is fed to the input of the PM, which produces a control effect on the PPP, thereby changing the speed of the master feed so that through the cutting process to reduce the magnitude of the error obtained at the output of the SC 2. Since the measured active power is proportional to the cutting forces, its stabilization allows It does not carry out the machining of a part with a given stock removal rate, determined by loading the cutting tool. In addition, the stabilization of power leads to the stabilization of elastic deformations in the technological system AIDS (machine-device-tool-part), which allows to obtain the same value of the deviation of the treated surface from the specified dimensions. This deviation may be taken into account and compensated for when setting up the machine. Consequently, in this case, not only productivity increases, but also machining accuracy, and the size deviations do not depend on the system of static and random variations of the cutting process, associated with changes in the cut cross section, hardness of the material being processed, blunting of the cutting tool, etc. in power and in error, the tracking system provides an increase in productivity while ensuring a given machining accuracy. However, from a review of the operation of the control loops, it can be seen that conflicting conditions may occur for a master feed rate. For example, in areas with a constant copier size, the PO produces such a control action in order to maximize the speed of the master feed, while in order to stabilize the power it is necessary to limit the magnitude of this speed. On the contrary, in some transition sections of the processed circuit, the power may become less than a predetermined level and to increase it, an increase in the driving feed will be required, but at the same time, the speed should be low to reduce the power tracking system error. In order to prevent such situations from occurring, it is necessary in the control process to carry out an analysis of which of the circuits should operate at the moment. For this purpose, the LU I was entered into its structure. Signals from the outputs of СЭ1 and СЭ2 are fed to the inputs of the Linac. Depending on the magnitude and sign of these signals, in accordance with the switching function programmed in the LN circuit, control signals are generated at its output, which, at input K 12, ensure the closure of one or another control loop. Since each control loop contains different functional elements, the static and dynamic characteristics of the circuits are different. This necessitates two different controllers, each of which is calculated from the conditions of a given quality of functioning. corresponding to the control loop.

Thus, this device allows, using a logical device, selecting the switching function accordingly, to organize the power control of the main motion engine and the error of the power tracking system so as to achieve optimal process conditions that increase productivity and accuracy of processing, and the ability to create time independent error and power control loops, allows to improve the quality of data management process output parameters copying th processing.

Claims (1)

Invention Formula A device for automatic control of a master feed of a copying machine, comprising a meter of an error module modulus of a tracking system, whose input is the first input of the device, a setpoint of an acceptable error value, a first comparing element whose inputs are connected to the outputs of a meter module The error and error tolerance generator, connected to the output of the first comparison element, the error regulator, the measuring transducer of the active power of the main motion engine, whose input is the second input of the device, the power setting unit and the second comparison element, whose inputs are connected to the outputs of the measuring converter and power setting device , characterized in that, in order to improve the quality of control of the two output parameters of the copying process through the organization of control loops, a logic device, a switch and a power regulator are inputted, the input of which is connected to the output of the second comparison element, and the output is connected to one of the inputs of the switch, the other two inputs of which are connected to the outputs of the error regulator and logical device, and the inputs the latter is connected to the outputs of the first and second comparing elements, and the output of the switch is the output of the device -. Sources of information taken into account during the examination 1. Vavilov A. A., Verkholat M. E. and Rubashkin I. B. Powerful electromechanical follow-up systems for copying and milling machines. M.-L., “Mechanical Engineering, 1964, p. 22-29.