SU1516374A2 - Control system for pumping/accumulator station of hydraulic presses - Google Patents

Abstract

The invention relates to mechanical engineering, namely to control systems of pump-accumulator stations. The purpose of the invention is to increase reliability and improve safety conditions. In the control system of the pump-accumulator station, additional flow meters, setters for maximum allowable flow rates and leakages and setter for the maximum allowable flow rate of liquid in the pressure line are installed. The electrical outputs of these devices are connected to a microprocessor, where the optimal number of pumps to be operated is calculated and the command is given to turn on or off their relief valves and electric drives, or turn on or off the press. 1 il.

Description

The invention relates to mechanical engineering, namely to control systems of pump and accumulator stations, and is an improvement of the invention according to the authors. St. No. 1283117.

The purpose of the invention is to increase reliability and improve safety conditions by controlling the amount of fluid flow in the discharge line.

The drawing is a schematic diagram of the control system.

The control system contains an accumulator 1, connected by a pressure line through a minimum level valve 2 to pumps 3, which inject fluid to presses and are equipped with discharge valves 5 and electric drives 6, flow meter 7, installed D line between pumps 3 and the press- {SP themselves, sensors 8 liquid level control, installed on the accumulator - D 1, setpoint adjusters 9 of average fluid flow, installed on j presses, microprocessor 10 and flow adjuster 11 of the maximum allowable flow rate of fluid in the pressure line. - Each of the presses 4 is provided with a setpoint 12 of the allowable amount of leakage from the press, a setting device 13 of the maximum allowable flow rate of the pressure line J of the press and additional flow meters with an electrical outlet installed in the pressure line of the press. The inputs of the microprocessor 10 are connected to sensors

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8, setting devices for the average fluid flow rate, setting device 11 for the maximum allowable flow rate of the pressure line, setting devices 12 with the allowable leakage from the presses, setting devices 13 for the maximum allowable consumption of the liquid for pressure lines of the presses C, flow meters 7 and I, and outputs for valve 2 minimum level-io n, unloading valves 5 and electric drives 6 pumps 3, as well as with pressures Ts.

The dials 11 - 13 are made in the form of a set of switches and 15 are used for inputting the initial information into the microprocessor 10. The flow meters I are equipped with a transducer of the measured travel of the fluid to an electrical signal.

The control system operates in the following way.

At the setting unit 9 of each press, k, the average fluid flow rate is set. The information from setters 9 enters microprocessor 25, where it is summed up and the number of pumps 3 is calculated to ensure the required flow rate. When the station is put into operation, the microprocessor 10, in accordance with the control algorithm, acts on the minimum level valve 2, the electric actuators 6 and the discharge valves 5 of the required number of pumps 3. The pumps 3 become under load, the minimum level valve 35 opens, the battery 1 connects to the pressure line which feeds the presses k. At the setting units 12 of each of the presses 4, the allowable value of 40 leaks from the press is set, and at the setting units 13 of each press, the maximum allowable flow rate of the pressure line of the given press k is set. Flow meters measure actual 45 instantaneous (current) flow rates of presses. Information from flow meters 1 enters microprocessor 10, where it is summed up during the technological cycle of manufacturing the product n on each of the presses.

 .

QU. q ;.

about

where Qts is the actual consumption of g g of liquid by an i-M press for the duration of the technological cycle of manufacturing the product,

T is the duration of the technological cycle of manufacturing the product on the i-th press, s; q is the instantaneous (current) flow rate of an i-M press, dm3 / s (measured by I flow meters).

In microprocessor 10, the actual amount of fluid leakage through leakages in the hydraulic system of each of the press presses 4 is calculated.

. QU-Qi.P where dQ is the actual amount of fluid leakage through leaks in the hydraulic system on ipress during the duration of the technological cycle of manufacturing the product, dmz; Рц is the calculated value of fluid consumption by i-M press for the duration of the technological cycle of the product, dm3 (this value is determined by summing up the information from the setting 9 of the average press fluid flow rate for the period of the technological cycle of the product).

The magnitude of ∆Rc is compared in microprocessor 10 with the setpoint on the setpoint 12 of the allowable leakage from this press k. In case of exceeding the actual value of the press fluid leakage, the setpoint value on the setting device 12 of the permissible leakage rate from the press A, the microprocessor 10 issues a command to the press, prohibiting it from further work. The magnitude of the set point on the setter 12 of the allowable amount of leakage from the press is established during operation.

The information from the flow meters And is compared in the microprocessor 10 with the settings on the setting devices 13 of the maximum allowable flow rates of the liquid of the pressure lines of the presses. If during operation the tightness of the line or compaction units of any press k is broken, at which the instantaneous (current) value of the fluid flow from the line of this press k exceeds the set point on its setting unit 13, the microprocessor 10 issues a command to close the minimum valve 2 and turn off electric drives 6 and loading valves 5 of pumps 3. Thus, the supply of fluid to the pressure line is stopped, the development of the accident at the press and in the station is prevented.

Information from the flow meter 7, measuring the instantaneous (current) flow rate of the liquid from the pressure line with all operating presses k, enters the microprocessor 10 and is compared with the set point on the setting unit 11 of the maximum allowable flow rate of the pressure line fluid. If during operation the leakage of the pressure line is broken, at which the instantaneous (current) flow rate of the pressure line exceeds the set point on its setting device 11, the microprocessor 10 also issues a command to close the minimum valve 2 and turn off the actuators 6 and the loading valves 5 of the pumps 3, thereby the supply of fluid to the pressure line is stopped and the development of an accident at the station is ruled out.

The economic effect of the implementation is achieved by increasing the reliability and safety of work.

Claims (1)

Invention Formula Control system of pump-accumulator station of hydraulic presses according to author. St. M 1283117, characterized in that, in order to increase reliability and improve safety conditions by controlling the amount of fluid flow in the pressure line, it is equipped with additional flow meters with electrical output, setting devices for maximum allowable flow rates and leaks in pressing lines, as well as setting unit permissible flow rate of fluid in the pressure line, with additional flow meters installed in the main lines of the presses, electrical outlets of additional flow meters, and setpoint max. flax allowable costs and leaks - in the line x presses setpoint maximum flow rate - in the pressure line and connected to inputs of the microprocessor. Compiled by V. Grinberg. Editor I. Shulla Tehred A. Kravchuk Order 6338/18 Circulation 528 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., W5 Proofreader T.Malets Subscription