SU419848A1 - SELF-ADJUSTING AUTOMATIC CONTROL SYSTEM FOR ELASTIC MOVEMENTS OF LATHE - Google Patents

Description

one

The proposed device relates to a technique for automating the machining of metals during longitudinal turning on lathes and can be used in the machine tool, automobile, aviation, bearing and other industries.

The automatic control systems for elastic mixing of turning machines are known, which contain the first element of comparison, the inputs of which are connected respectively to the setter and the sensor of the elastic displacement of the AIDS system, and the output to the first input of the first key, the second control input of which is connected to the output of the zero-organ connected to the AIDS elastic displacement sensor; an amplifier, the output of which is connected to the first input of the second comparison element, the second input of which is connected to the output of the setpoint feed rate control unit, and the second switch, the first input of which is connected to a DC power source, and the second control input to the zero-output terminal; the electrical conductor, the input of which is connected to the output of the second comparison node, and the output to the input of the longitudinal feed mechanism, the output of the latter connected to the input of the AIDS system.

Significant disadvantages of the known automatic control systems

The class under study is the change in the parameters of the systems in the process of machining parts with variable allowance and varying metal hardness. At the same time, the transmission coefficient of the AIDS system (KSPR1D), which is proportional to the depth of cut and hardness of the material being processed, varies most significantly. The variations of the CSSP lead to a decrease in the static and dynamic accuracy of the elastic displacement control system.

In order to increase machine productivity and improve the quality of machined

parts, as well as ensuring static and dynamic accuracy when changing the depth of cut or operation of the machine, the system contains 1 nonlinear element whose input is connected to the output of the first key, and

output - to the input of the amplifier, the setting body

which is mechanically connected to the setter

elastic transfer system values

AIDS.

In addition, the self-adjusting system is characterized in that it contains a dark snifter of the infeed feed, the input of which is connected to the output of the second key, the output with the adjuster of the infeed feed amount, and the adjusting organ mechanically

associated with a setting knob.

FIG. 1 is a functional system diagram; in fig. 2 - a simplified electrical circuit diagram of the blocks drying the automatic compensation of changes in the transmission coefficient of the SPR1D system and the automatic transition of the system from the plunging mode to the working feed.

The self-adjusting system of automatic control of elastic displacements contains: unit deformation magnitude 1, first key 2, nonlinear element 3, amplifier 4, electric longitudinal feed 5, longitudinal feed mechanism 6, machine tool-device-part-system (AIDS) 7, sensor for elastic deformation 8, unit for setting feed rate 9, unit for reducing feed rate for 10, Biopofi key 11, source of current 12, zero body 13, resistors 14-16, capacitor 17. diodes 18.

The self-adjusting system of automatic control of elastic displacements is a closed automatic system for stabilizing the magnitude of the elastic deformation, which is defined by the setting device 1 (resistor 14, Fig. 2). The actual deformation value is measured by sensor 8, and the measurement result in the form of a nanorc dc loc is algebraically summed with the driving voltage t / back. The error signal and / backs is fed from via the key 2 to the input of the nonlinear element 3. The key 2 closes when there is a command on its control input from the null organ 13, which, according to a signal from the sensor 8, controls the moment the tool has penetrated into the part. The signal from the output of the nonlinear element 3 is fed to the input of the amplifier 4, amplified last and the output signal of the amplifier is summed algebraically with the signal from the feeder of the infeed 3. The summation is fed to the input of the electric drive of the longitudinal feed 5, the rotational speed of which turns into SCP by means of a longitudinal feed mechanism 6. The longitudinal feed rate is the regulatory impact on the AIDS system 7, the output coordinate of which is the elastic value Reformation and typical perturbation E - change in the cutting depth and the hardness of the workpiece material NB.

At the moment of insertion of the tool into the part, simultaneously with the closure of the system carried out by the key 2, the power supply 12 of the setpoint for the iodine insertion 9 (adjustable resistor 15, fig. 2) is turned off by means of the key 11. The key 11 opens if there is a command to his control input from the zero-body 13. As the keys 2, 11 can be used, respectively, the closing and opening contacts of the electromagnetic relay that receives the command and the operation of the zero-body. After disconnecting the voltage source

power 12, the rate of decay of the gap at the output of the setpoint feed rate controller t /: spon is determined by the constant time of the discharge; and the chains the resistor 15 is the 16th-5th bone resistor 17. The constant-time value is set by the adjustable resistor 16, the slider of which is mechanically locked with the setting engine of the feed rate of the plunging 9 in such a way that, with an increase in the voltage of the traverse / field 0, the con stant discharge time of the chain 15-16-17 decreases.

When the system is operating in the closed state, the error signal is numerically equal to

and,

and,

l + kp

where C / ass is the setpoint signal of the elastic strain, & p is the gain of the disconnected system.

At a certain value of the setting signal t / back and a sufficiently large gain of the open-loop system, which is the case in practice, the error signal

5 f / o is inversely proportional to ip. By incorporating into the direct circuit a system of nonlinear element 3, the transfer coefficient of which is proportional to the magnitude of the signal Lj, compensation for the variations of k-p due to the change in the transfer coefficient of the cpsd is achieved.

When a master signal is measured, in order to meet the conditions for compensating the variations of the SPID, by changing the transmission coefficient of the nonlinear element, it is necessary to change the characteristic of the latter. This is achieved by the mechanical connection between the handle of the step unit for the amount of elastic deformation (Fig. 2) and the handle

0 step switch circuit nonlinear elements. As nonlinear elements, semiconductor diodes 18 operating on a nonlinear part of the characteristic can be used.

Subject invention

Claims (2)

1. A self-adjusting system of automatic control of the elastic movements of the lathe, containing the first element of comparison, the inputs of which are connected respectively to the setting device and to the sensor of the elastic movement value of the AIDS system, and the output to the first input of the first 5 of the key, the second control input of which is connected to the output of the zero-organ connected to the elastic displacement sensor of the AIDS system, the amplifier whose output is connected to the first input of the second comparison element, the second input of which is connected to the output of the feed rate setting knob, and the second key, The first input of which is connected to a DC power source, and the second control input is connected to the output of the null organ; electric drive, the input of which is connected with the output of the second comparison node, and the output with the input of the androdol feed mechanism, the output is subsequently connected to the input of the AIDS system, characterized in that, in order to increase machine productivity and improve the quality of the machined parts, as well as provide static and dynamic accuracy when changing the depth of cut or modes of operation of the machine, it contains a nonlinear element, the input of which is connected to the output of the first key, and the output to the input of the amplifier, and whose tuning body is mechanically ki associated with setpoint values elastic movement AIDS system. 2. It is self-adjusting, and the system of claim 1, characterized in that it contains a cut-off feed rate sensor, the input of which is connected to the output of the second key, the output is connected to the input unit of the feed rate, and the tuning element is mechanically connected to the setting device filing cut 1i.