SU1445904A1 - Arrangement for controlling feed drive of machine operating element - Google Patents

Abstract

The invention relates to a machine tool industry, in particular to machines for electrolytic processing. The aim of the invention is to increase the accuracy, quality and productivity of processing by expanding the range of torque control and ensuring stable operation of the movement at small moments while pressing the working body to the workpiece. The device contains a control circuit that allows, during the pressing of the tool to the part with little effort, to exclude an abrupt change in the torque of the engine. The control resistor 16 is shunted by the breaker contact 17 of the control element, and the breaking contact 19 of the second control element is installed in the drive of the supply of the machine tool to the motor winding circuit. silt G g

Description

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The invention relates to machine tool construction, namely, to machines for electrolytic processing.

The aim of the invention is to improve the accuracy, quality and productivity of processing by expanding the range of torque control and ensuring stable operation of the engine at low moments while pressing the working body to the workpiece.

The drawing shows a diagram of the drive for feeding the table of a machine for the electrochemical machining of holes using tools equipped with polycrystals of superhard materials.

On the table 1 of the machine, there is a working body (grinding head) 2 with a tool 3 for machining a hole in the workpiece 4 fixed in the cartridge 5 of the workhead, which has the ability to move perpendicular to the direction of movement of the table. The tool and the workpiece are connected to the negative and positive poles respectively source of technological current. A hundred through a kinematic circuit is connected to an electric motor 6 of direct current 5 connected to a thyristor {at the control unit 7 via motor control circuits,

The kinematic chain consists of a nut with a running gear 8, which can be connected alternately by means of electromagnetic clutches 9 and .O can be connected with worm gears P and 12 with left or right cuts, and the belt transmission with pulleys 13-i5.

The control circuits contain an adjustable resistor 16 (Rl) s connected

Resistor R I 1 6 of type 1ShB-25E- 2.2 kΩ is additionally introduced into the drive circuit - into the control circuit of the excitation winding, resistors R2 (24.)

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motor and shunted disconnect-d | - type P11B-15G-360 Sm, R3 (23) type pin 17 (K1) of the control unit 1ШБ-15Е-6.8 kOhm - to the rotation speed task circuit and contacts K1 (17), 2 (20,25,26) relays 18 and 21 with limit switches 27 and 28.

The voltage of the process current source is connected to the workpiece and the instrument.

When filing a nominal capr same--. Neither the motor windings move the table from the 7SODE position rapidly to the treatment area, with the relays K1 (18) and K2 (2) disconnected. In the treatment area, the supply of a lubricant-coolant is included, as well as the corele 18 (K1), the windings of the reactor 19 (L) with the opening contact 20 (K2.1) of the second brine 21 (K2) on the feedback loop which, together with the resistors of the control unit 7, form the tachometer bridge of the rotational speed sensor, the reference circuit of the engine rotational speed with the main one is adjustable. resistor 22 (R4) and optional unregulated 23 (R3) and adjustable 24 (H2) resistors; -, the moving contacts of these adjustable resistors coe i; more

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between each other, with the opening contact 25 (K2.2) being introduced into the moving contact circuit of the main resistor to the point of its connection with the additional contact, and the second relay 21 closing contact 26 (K2.3) to the moving contact circuit of the additional resistor, 27 (SQI), which includes control relays 8 and 21 (K1, K2) in the working area, the switch 28 (SQ2), is turned off. these relays after the removal of the rough stock, and the switch 29 (SAL), disconnecting the relay 18 (K1) when the engine is running in the upper range of the torque control without changing the excitation voltage.

The magnitude of the resistor 23. (CZ) is adopted such that when the resistor 24 (R2) is fully removed, the current of the inhibited motor core does not exceed the nominal value.

Consider the operation of the feed drive. the table in the internal splicing machine for electrochemical grinding when machining the working area of the channel in carbide treads with a diameter of 3 mm (tests are carried out on a model).

For the table feed drive, a complete electric drive of the ET1E1-3 type was used, the kit of which includes a crystal regulating unit 7, an electric motor 6 of the type EP110 / 245 with a nominal voltage V B on the windings of the core and excitation and a horizontal current of the core 3, 27 A, the reactor 19 and the setting frequency adjuster 22 (the main adjustable resistor),

Resistor R I 1 6 of type 1ShB-25E- 2.2 kΩ is additionally introduced into the drive circuit - into the control circuit of the excitation winding, resistors R2 (24.)

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The GQ1 switch (27) switches the relays (18) K1 and (21) K2 on when the engine is running in the lower control range of the torque (when the engine is running in the upper range, the relay turns on (21) K2

The opening contact K2.1 (2.0) of the relay (21) K2 switches off the feedback, the opening contact K2.2 (25) turns off the main adjustable resistor R4 (22), and the closing contact K2.3 (26) connects additional resistors R2 (24 ), R3 (23), which reduces the voltage across the core to 0.6 V, the current in the core windings decreases to 0.32 A, the K1 break contact (17) of the relay 18 introduces the resistor R1 (16) into the circuit the winding BOZ-bullet, which reduces the voltage in it to 10 V. When the tool touches the workpiece, the motor torque becomes 0, Nm, and the techno a logical current flows through the circuit, the current source, the workpiece, the lubricant-cooling fluid, is pumped under pressure through the interelectrode gap of the tool -1ent, the current source, resulting in the electrochemical removal of the rough allowance. The interelectrode gap is created by current-conducting plates of polycrystalline superhard materials fixed on the conductive mandrel of the tool.

Then the table is reported to oscillate at a speed of 0.1-1 m / min, while the control elements K1 (18) K2 (21) are turned off by the SQ 2 limit switch (28), and the reversal is performed by alternately turning on the electromagnetic clutches 9 and 10 .

The grinding of the hole is carried out first with the technological current, and then fine-tuned without current, while

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With the help of special devices, the working surface of the tool is contacted with the conical surface 1.

Claims (1)

Invention Formula Drive control unit supplying the machine tool, containing a thyristor control unit, a direct current motor with an excitation winding with a control circuit, a speed reference circuit with a main adjustable resistor, a rotation frequency sensor in the form of a tachometer bridge, one of the arms of which is formed by the compensation winding of the reactor and resistors, characterized in that, in order to improve the accuracy, quality and performance of the treatment, the control circuit of the motor field winding is equipped with an adjustable resistor and two m control relays with normally closed and open contacts, the adjustable resistor of the control winding circuit is normally extended closed contact of the first relay, and in the shoulder tachometer. the bridge has a normally closed contact of the second relay, the reference frequency circuit is provided with two series-connected additional resistors connected in parallel to the main adjustable resistor, one of which is adjustable and the moving contacts regulated resistors are interconnected, with a normally closed contact in series with the moving contact of the main adjustable resistor, and a normally open contact of the second relay connected with the moving contact of the additionally introduced adjustable resistor.