SU1220730A1 - Method of controlling the process of machining - Google Patents

Description

The invention relates to a machine tool industry, in particular, to automatic control of the process of finishing and strengthening mechanical processing of intermittent GEO-surfaces of parts, and can be used in various areas of mechanical engineering during strengthening processing on special machine equipment.

The aim of the invention is to increase the accuracy and increase the durability of the tool by controlling its position against the surface breaks, which eliminates the possibility of tool breakage.

FIG. 1 shows a block diagram of the device, realizing, its method; in fig. 2 - signal diagrams.

The device contains a transducer 1 for registering the magnitude of a hollow of a discontinuous surface associated with a block 2 for generating rectangular pulses with a duration equal to the length of the arc (value) of the depression, block 3 for delaying rectangular pulses connected via a first controlled electronic key 4 to a controlled integrator 5 , setting unit 6 of the depth of the deformed layer, adjustable electric drive 7 of the tool 8, converter, 9 recording the frequency of the workpiece 10, block 11 generating a correction control signal post about the integration time of unit 5, connected to the second controlled electronic key 12. The essence of the method is based on the peculiarities of forming a control signal that varies according to a complex law and ensures that the actuator acts on a smooth control of the working tool, eliminating the cyclic pulse loading of the latter, ensuring a predetermined depth of the deformed layer and its shaping quality when machining broken surfaces.

The depth of the deformed layer is set by the setting device b in the form of an analog voltage acting through block 5 and keys 4 and 12 on the electric drive 7, controlling the first position of the tool 8.

Taking into account the processing of discontinuous surfaces, the control signal, which varies in time according to a complex law, is formed as a function of the continuous path traversed by the tool. To do this, measure the length of the hollow of discontinuous surfaces using a contactless transducer 1 (for example, eddy current) and form a signal in the form of rectangular pulses using block 2, the duration of which is proportional to the length of the depression of the discontinuous part of the surface, and the length of the continuous part is proportional to the pause between pulses. Due to the speed of the adjustable drive and the leading measurement position on

25

yi-ol f with respect to the machining position, it is possible, taking into account changes in the surface profile and part rotation frequency, as well as transients, to form the voltage of the automatic correction of the control signal determining the smooth spraying speed and a predetermined depth of the deformed layer from the moment the tool touches the part.

0 Since the measurement position is ahead

processing position by the angle φ, then the generated signal in the form of a rectangular pulse is automatically delayed in time with the help of delay unit 3 by

15ZOh,

the value of T3a.i., where n - the number of revolutions

the details.

When the delay time (Thad) expires, the tool is removed from the treatment area by applying a square pulse 20 to the electronic switches 4 and 12. The electronic switch 4 closes and the electronic switch 12 opens, which causes the control signal from the output to stop. setting device 6 of the depth of the deformed layer to the input of the electric drive 7 through the electronic switch 4 and the integrator 5. Opening the electronic switch 12 quickly discharges the capacitance of the integrator 5 and prepares it for the subsequent control cycle to the next Orot details.

After the expiration of the length of the rectangular pulse, when the beginning of the continuous surface is fed into the treatment zone, the electronic key 4 is opened and the electronic key 12 is closed. The indicated state of the electronic switches provides an abrupt supply of a predetermined control voltage from the output of the setting device 6, corresponding to the specified depth of the deformed layer, through the integrator 5 to the input of the electric drive 7 of the transverse feeding of the tool 8 to the part 10.

The exponential insertion of Instrument 8 from the moment the tool 8 touches the part 8 is carried out by integrating a discrete increment of a predetermined signal by the integrator 5, which is supplied to the integrator 5 through the electronic key 4. In this case, the integration time constant is set automatically as a function of changing the frequency of rotation of a part with the help of a circuit formed by a converter 9 for registering the frequency of rotation of a part W and a unit 11 for generating a control voltage that changes the time constant RC circuit of the integrator 5, by changing the value of the resistor R, as which,

55 for example, using the drain - source transition of a field effect transistor.

A change in the resistance of the resistor R leads to a change in the rate of increment

thirty

35

45

50

curve going to the exponent. The maximum signal level after the integration time expires is set equal to the voltage set by setpoint 6 corresponding to a predetermined depth of the deformed station (Fig. 2, where Ui is the signal at the key 4 output; Ui is the signal at the output of block 5; U is the given signal; ti - rise time of the signal to a predetermined level). This signal level is maintained at the input of the adjustable actuator 7 as long as the continuous part of the workpiece surface is in the treatment area,

2

.

i.e. maintained for a time

, 30 (2S - d)

where n is the number of revolutions; but

LL

the central angle encompassing the length of the arc of the depression.

After the time t has elapsed, a rectangular pulse appears at the output of block 3, the switching state (position) of the electronic keys 4 and 12, and the process of controlling the lateral feed of the working tool 8 according to the described law repeats for each revolution of the part 10.

hell.

FIG. 2

Claims (1)

METHOD FOR CONTROLING THE PROCESS OF PROCESSING of discontinuous surfaces, in which the size of the workpiece is measured and the tool feed is controlled, providing a predetermined value of the deformable layer of the processed surface, characterized in that, in order to improve accuracy and increase tool durability, the moments of breaks of the processed surface under the tool are recorded and at these moments take it away from the surface being machined, determine the moments of the end of the surface breaks under the tool by measuring the length of the breaks and the speed of rotation of the part, and at these moments the tools report a mortise feed, which is carried out according to the exponential law of changing the magnitude of the deformable layer to its predetermined value. yu № Oh GO About FIG. 1