Autonomous electrohydraulic steering drive with ls regulation

Abstract

FIELD: electrohydraulic servo drives.SUBSTANCE: autonomous electrohydraulic steering drive consists of a drive electric motor connected via a shaft to a pump and connected via an amplifier to a control microcontroller, to the input of which an external control signal is supplied, a make-up unit containing a pneumatic-hydraulic accumulator, check and safety valves, an electrohydraulic distributor controlled by a microcontroller, a hydraulic motor equipped with a displacement sensor, the output of which is connected to the control microcontroller, characterized in that it contains an OR valve connecting the cavities of the hydraulic cylinder with a load-sensitive control system including a constant pressure differential valve, a pressure compensation valve and a safety valve of the pump discharge line, wherein the pressure compensation valve is connected to the pump discharge lines before the constant pressure differential valve and after the OR valve, as well as with a cylinder for regulating the characteristic working volume of the pump.EFFECT: increase in the operating accuracy of an autonomous electrohydraulic steering drive when the static load changes, an increase in efficiency and stability while maintaining the weight and size characteristics by introducing a load-sensitive control system into the hydraulic drive.1 cl, 1 dwg

Description

[0001] The invention relates to servo-hydraulic drives and can be used in electro-hydraulic systems as an autonomous steering drive for controlling the flight of an aircraft.

[0002] A self-contained electro-hydraulic drive with combined output link speed control is known, which contains: electronic units of a control microprocessor and an amplifier-inverter, a brushless DC electric motor, a fixed pump, a hydraulic cylinder, a hydraulic compensator, make-up valves, safety valves, a filter, a hydraulic cylinder rod position sensor, an electro-hydraulic reverse valve with a linear electric motor, a reverse valve spool position sensor and differential pressure sensors at the inlet and outlet of the reverse valve. (Patent RU No. 2305210 / C2, IPC F15B 9 / 09, published on August 27, 2007).

[0003] The disadvantage of the analogue is the instability of the output characteristics of the autonomous electro-hydraulic drive.

[0004] A self-contained electro-hydraulic drive of the electro-hydrostatic type from Liebherr-Aerospace Lindenberg is known, containing an electronics unit of an electric motor and a ring valve, a brushless DC motor, a reversible unregulated pump, a hydraulic cylinder, and auxiliary elements: a gas-hydraulic hydraulic compensator, pump anti-cavitation valves, safety valves, an electro-hydraulic ring valve, cylinder anti-cavitation valves, a filter with its safety valve, a safety valve, positional feedback. (Konstantinov G.S. Prospects and problems of creating steering actuators with electric power supply / G.S. Konstantinov, V.M. Kuvshinov, I.P. Kuznetsov, A.A. Parshin, P.G. Redko, A.I. Steblinkin, L.V. Khaletsky / / Bulletin of the Moscow Aviation Institute: journal article - scientific article, Moscow, 2013 Moscow: Moscow Aviation Institute (National Research University), 2013, pp. 149-160.− EDN QCAWJZ, ISSN: 0869-6101.).

[0005] The disadvantage of the analogue is the unstable operation of the autonomous electrohydraulic steering drive when the load on the executive hydraulic motor changes, as well as the discrepancy between the input signals from the electric motor and the values ​​of the actual energy demand for the pump in a situation of random load on the hydraulic drive.

[0006] The closest in technical essence is an autonomous electrohydraulic steering drive with additional feedback on dynamic pressure, which contains a drive electric motor connected through a shaft to a pump and connected through an amplifier to a control microcontroller, to the input of which an external control signal is supplied, a make-up unit containing a pneumatic-hydraulic accumulator, check and safety valves, an electrohydraulic distributor controlled by a microcontroller, a hydraulic motor equipped with a displacement sensor, the output of which is connected to the control microcontroller, a valve connected to the cavities of the hydraulic motor, and also connected to a throttle, a spring-loaded plunger, pushers with adjustable springs, wherein the pushers themselves are connected to each other mechanically and at the same time connected to a rocker arm and then to a multi-position three-way distributor located inside a piston, which is mechanically connected to a pump.(Patent RU 2826237 C1, IPC F15B 9 / 09, published 06.09.2024).

[0007] The disadvantage of the prototype is the insufficient accuracy of the autonomous electrohydraulic steering drive when the static load on the actuator hydraulic motor changes.

[0008] The objective of the invention is to ensure that an autonomous electrohydraulic steering drive is insensitive to the load.

[0009] The technical result of the invention is to increase the operating accuracy of an autonomous electrohydraulic steering drive when the static load changes, to increase the efficiency and stability while maintaining the weight and size characteristics by introducing a load-sensitive control system (LS-control) into the hydraulic drive.

[0010] The stated problem is solved, and the technical result is achieved by the fact that an autonomous electro-hydraulic steering drive consisting of a drive electric motor connected through a shaft to a pump and connected through an amplifier to a control microcontroller, to the input of which an external control signal is supplied, a make-up unit containing a pneumatic-hydraulic accumulator, check and safety valves, a multi-position electro-hydraulic distributor controlled by a microcontroller, a hydraulic motor equipped with a displacement sensor, the output of which is connected to the control microcontroller, in contrast to the prototype has an "or" valve connecting the cavities of the hydraulic cylinder with a load-sensitive control system including a constant pressure differential valve, a pressure compensation valve and a safety valve of the pump discharge line, wherein the pressure compensation valve is connected to the pump discharge lines before the constant pressure differential valve and after the "or" valve,and also with a cylinder for regulating the characteristic working volume of the pump,

[0011] The essence of the invention is explained by a drawing, which shows a basic diagram of an autonomous electro-hydraulic steering drive with an additional load-sensitive control system (LS-control).

[0012] The autonomous electro-hydraulic steering drive comprises a pump 1 with a drive electric motor 2, an amplifier 3 and a control microcontroller 4, wherein the pump 1 supplies the working fluid to a multi-position electro-hydraulic distributor 5 connected to a hydraulic cylinder 6 equipped with a displacement sensor 7. The steering drive also comprises a make-up unit consisting of a pneumatic-hydraulic accumulator 8, check 9 and safety 10 valves. The cavities of the hydraulic cylinder 6 are connected by means of the “or” valve 11 with a load-sensitive control system (LS-control), which includes a constant pressure differential valve 12, a safety valve 13, a pressure compensation valve 14 and a cylinder 15 that controls the pump capacity. The pressure compensation valve 14 is connected to the discharge lines of the pump 1 before the constant pressure differential valve 12 and after the “or” valve, as well as with the cylinder 15 that controls the characteristic working volume of the pump.

[0013] The independent electro-hydraulic steering drive with LS control operates as follows.

[0014] The rotation frequency of pump 1 is determined by drive electric motor 2, amplifier 3 and control microcontroller 4. Pump 1 supplies working fluid to electro-hydraulic distributor 5 connected to hydraulic cylinder 6 equipped with displacement sensor 7, the output of which is connected to control microcontroller 4. An electrical signal supplied to electromagnets of electro-hydraulic distributor 5 controls the direction and speed of movement of piston of hydraulic cylinder 6.

[0015] The load sensitivity controller (LS controller) is capable of adjusting the operation of the autonomous electrohydraulic steering drive depending on various types of loads of varying magnitudes acting externally on the hydraulic cylinder rod. Initially, in the absence of control signals to the multi-position electrohydraulic distributor 5, the springs move its spool to the neutral position. However, since the spools' flow areas are closed, the resulting increase in pressure, acting on the pressure compensation valve 14, moves its spool, supplying pressure to the piston of control cylinder 15 of pump 1, and brings the pump to minimum capacity, while the hydraulic cylinder rod 6 remains stationary.

[0016] When a control signal is applied to multi-position electro-hydraulic valve 5, its spool moves proportionally to the incoming signal, and the working fluid enters the working chamber of hydraulic cylinder 6. The other chamber of hydraulic cylinder 6 is connected to the drain. The pressure downstream of multi-position electro-hydraulic valve 5 is determined by the loads acting on the piston rod of hydraulic cylinder 6. Constant pressure differential valve 12, using information from "OR" valve 11, detects this pressure change and opens, allowing flow and creating pressure sufficient to overcome the external load. As a result of valve 12 opening, the pressure upstream of it drops, and the piston of the control cylinder of regulator 15 of pump 1 moves under the action of a spring, increasing the working volume of pump 1.This leads to an increase in the pressure differential across hydraulic cylinder 6 and, accordingly, to an increase in the piston speed of hydraulic cylinder 6, which corresponds to the control signal according to the control program. The nominal pressure in the control system is set according to the current load. For this purpose, using the "or" valve 11, pressure is drawn from the working chamber of hydraulic cylinder 6 and transmitted to the pressure compensation valve 14 of pump regulator 1. The regulator sets the supply pressure of hydraulic cylinder 6 sufficient to overcome the external load and ensure the best energy characteristics.

[0017] Thus, the proposed hydromechanical regulator with LS regulation can improve the running stability and energy efficiency of the actuator hydraulic cylinder by using a load-sensitive control system in the hydraulic drive.

Claims

An autonomous electrohydraulic steering drive consisting of a drive electric motor connected via a shaft to a pump and connected via an amplifier to a control microcontroller, to the input of which an external control signal is supplied, a make-up unit containing a pneumatic-hydraulic accumulator, check and safety valves, an electrohydraulic distributor controlled by the microcontroller, a hydraulic cylinder equipped with a displacement sensor, the output of which is connected to the control microcontroller, characterized in that it additionally contains an "or" valve, connecting the cavities of the hydraulic cylinder with a load-sensitive control system including a constant pressure differential valve, a pressure compensation valve and a safety valve of the pump discharge line, wherein the pressure compensation valve is connected to the pump discharge lines before the constant pressure differential valve and after the "or" valve, as well as to a cylinder for regulating the characteristic working volume of the pump.

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