SU1643181A1 - Servo control mechanism of hydraulic press - Google Patents

Description

(21) 4628338/27

(22) 12/29/88

(46) 23.04.91. Bul P 15

(71) Kramatorsk Industrial Institute

(72) Yu.A.Shvetsov, V.E.Ustinov and G.V.Vasyutin

(53) 621.97 (088.8)

(56) USSR author's certificate

V 1388326, class B 30 B 15 / 16.08.12.86,

(54) SERVICE CONTROL FOR THE SHAFT OF HYDRO DISTRIBUTOR OF HYDRAULIC PRESS

(57) The invention relates to mechanical engineering, in particular, to a servo drive for controlling the shaft of a hydraulic distributor of a hydraulic press. The purpose of the invention is to expand technological capabilities and increase productivity. The hydraulic booster is connected to the cavities of the power cylinder connected to the camshaft via two-position valves with electromagnetic control. Additional cylinders are installed symmetrically with respect to the camshaft, the cavities of which are interconnected and through an electromagnetically controlled valve with a pressure source and a drain line. The electronic control system allows precise positioning of the camshaft and automatically returning it to its original position in the event of system malfunctions, which increases the accuracy of the mechanisms. 1 il.

The invention relates to mechanical engineering, namely to hydraulic presses.

The purpose of the invention is to expand technological capabilities and increase productivity by increasing the accuracy of the mechanisms.

The drawing is a schematic diagram of the servo.

The servo drive includes a power cylinder 1, connected by its rod 2 with the camshaft 3, successively interconnected adder 4, power amplifier 5, electromechanical converter

6 and the hydraulic booster 7 with spools 8 and 9. The position sensor 10 is connected by its input to the shaft 3 and the output to the input of the adder 4, the output of which is connected to the input of the comparator 11, the output of which is connected to the input of the key 12, the second input of which is connected to the output generator 1 3 pulses. The output of the key 12 through the pulse counter 14 is connected to the input of the element 4 and 15, the output of which is connected to the key 16. The hydraulic booster 7 is connected to its outputs through two-way valves 17 and 18 with control electromagnets with piston 19 and rod 20 cavities. Symmetrical about

316

shaft 3 installed additional cylinders 21 and 22, interacting with their rods 23 and 24 with the shaft 3.

The cavities 25 and 26 of the cylinders 21 and 22 through the distributor 27 are connected to a pressure source and a drain line. The output of the switch 16 is electrically connected with the solenoids of the distributors 17.18 and 27.

The servo works as follows.

The error signal, proportional to the angle of rotation of the distributor shaft 3, is fed to the first input of the adder 4, summed with the signal coming from the output of the position sensor 10, amplified by the power amplifier 5 and fed to the input of the electromechanical converter 6, displacing proportional to this signal, the valve 9, resulting in the working fluid through the valves 17 and 18 enters the cylinder 1, which turns the shaft 3 into the specified positioning position. When approaching a predetermined position, by positioning the signal at the output of position sensor 10, having the opposite sign as compared to the signal at the first input of adder 4, increases, the signal at adder output 4 decreases and becomes equal to zero when the shaft 3 reaches the specified position of positioning, electromechanical The converter 6 closes the hydraulic booster 7 and the rod 2 of the cylinder 1 stops by turning the shaft 3 to the predetermined position. In case of malfunction of the electronic part of the servo drive, power amplifier 5 is an electromechanical transducer 6 or when the hydraulic booster 7 or sensor 10 is out of service, the signal at the output of the adder 4 for 0.2-0.3 s (maximum rotation time of the hydraulic control valve from one extreme) position in the other) will be different from zero. In this case, the comparator 11 sends a signal to the control input of the key 12, which begins to pass pulses from the output of the generator 13 to the input of the counter 14. After 0.2-0.3 s, the binary code of the number of pulses at the output of the counter 14 is compared with the binary code the task on element 4 and 15 and the latter sends a signal to the input of the key 16, which de-energizes the electromagnets

valves 17.18 and 27. At the same time, valves 17 and 18 are moved to the right position according to the scheme and the hydraulic connection of hydraulic booster 7 is disconnected from the cavities 19 and 20 of cylinder 1 and the cavities 19 and 20 are connected to the drain line. At the same time, the valve 27 moves to the right-hand position and disconnects the drain line from the cavities 25 and 26 of the additional cylinders 21 and 22 and connects the cavities 25 and 26 to a pressure source. The rods 23 and 24 moving to the extreme positions, set the shaft 3 in the neutral position, corresponding to the stop of the movable cross-member of the press.

The economic effect of the invention is achieved by expanding technological capabilities and increasing productivity.

5 0 5 Q .- D5 -;

five

Claims (1)

Invention Formula A servo drive for controlling a hydraulic control valve shaft, a press comprising a power cylinder connected to a camshaft by a rod, a series-connected adder, a power amplifier, an electromechanical converter and a hydraulic booster, a position sensor connected to the input of the camshaft and the output to the adder input, and a pressure source and a drain line connected to the hydraulic booster inlets, characterized in that, in order to expand technological capabilities and enhance by increasing the accuracy of the mechanisms, it is equipped with three two-position valves with electromagnetic control, two Additional power cylinders, a comparator, two keys, a pulse counter, a pulse generator and element 4I, while the additional power cylinders are installed symmetrically relative to the camshaft with the possibility of interaction with the latter and their cavities are interconnected and through one of the two-way valves with a pressure source and a drain line, hydraulic outlets are connected through the second and third distribution; dividers with the cavity of the main power cylinder, the comparator is connected by its input to the output of the adder, the first key is connected by the SRPMI inputs to the outputs of the adder and generator Sliena highway From pressure source pulses and outputs with a pulse counter, and the second key is connected to the input through element 4I with the outputs of the pulse counter and the output from the electromagnets of two-pin distributors.