CN201461603U

CN201461603U - Hydraulic control device of oil motive

Info

Publication number: CN201461603U
Application number: CN2009200778205U
Authority: CN
Inventors: 万保中
Original assignee: SHANGHAI HUIYI HYDRAULIC ENGINEERING Co Ltd
Current assignee: Shanghai Huiyi Control System Co., Ltd.
Priority date: 2009-07-03
Filing date: 2009-07-03
Publication date: 2010-05-12
Anticipated expiration: 2019-07-03

Abstract

The utility model relates to a hydraulic control device of oil motive, which relates to the technical field of hydraulic control, and solves the technical problem that a prior system with low cost has slow response speed and low control reliability. The system comprises a piston type oil motive, a control unit and an oil tank, and is characterized in that the control unit comprises two direct-drive type volume control circuits which are connected in parallel, each direct-drive type volume control circuit comprises an oil pump, an alternating current servo motor, an accumulator and an electromagnetic reversal valve, an oil port of the oil pump is respectively connected with a work cavity and the accumulator of the oil motive through a hydraulic control one-way valve and the electromagnetic reversal valve, another oil port of the oil pump is connected with another work cavity of the oil motive through the hydraulic control one-way valve, the accumulator is respectively connected with two work cavities of the oil motive through two rapid switch electromagnetic valves, and the two oil ports of the oil pump are connected with the oil tank respectively through the hydraulic control one-way valve. The system has low cost and high control reliability, and has rapid response speed.

Description

A kind of hydraulic control device of oil engine

Technical field

The utility model relates to the technology of hydraulic control, particularly relates to a kind of technology of hydraulic control device of the oil engine that is used for small steam turbine (feed water pump) regulating system.

Background technique

Oil engine (oil hydraulic cylinder) is the power unit of steam turbine (feed water pump) adjusting and security system, and its major function is to change its piston action of control in real time by hydraulic pressure, and then the aperture of control steam turbine valve.

Traditional steam turbine (feed water pump) regulating system all adopts valve control oil engine electrohydraulic servo system, this system (referring to Fig. 2) adopts the electrohydraulic control Hs by outside fuel feeding, the oil inlet P of electrohydraulic control Hs is connected outside oil sources respectively with oil return inlet T, and two control ports connect two active chambers of piston type oil engine U2 respectively; Transfer valve bit instruction signal during operation, the valve position feedback signal LVDT of oil engine U2 after transferring electrical signal to, demodulator TD is compared with valve position command signal C, and according to comparative result control electrohydraulic control Hs action, and then the piston stroke of control oil engine U2.Because electrohydraulic control has speed of response faster, therefore this system can satisfy the requirement of the regulating system of steam turbine (feed water pump) to quick response well.But because the intrinsic structural feature of electrohydraulic control itself, make this system have following shortcoming: 1) requirement on machining accuracy of electrohydraulic control is higher, and its price is very expensive; 2) because the electro-hydraulic servo valve arrangement is tiny and valve body is fragile, therefore responsive especially to oil contamination, its spool is caused malfunctioning easily by the wearing and tearing of the impurity in the fluid, therefore must be equipped with the very high filtration system of filter precision; 3) because electrohydraulic control is responsive to temperature variation, and the energy loss of valve control oil engine electrohydraulic servo system is very serious, and its throttling heating is bigger, therefore must be equipped with more perfect cooling system; 4), thereby the volume and the complexity of entire system have been increased because electrohydraulic control by outside fuel feeding, therefore needs a cover pumping station system that constant pressure oil source is provided; 5) be in inoperative during the cycle (pressurize operating mode and idle running operating mode) when system, system still locates running state, has increased operating cost.Above-mentioned shortcoming makes that the cost of valve control oil engine electrohydraulic servo system is higher.

In order to overcome the shortcoming of valve control oil engine electrohydraulic servo system, a kind of directly driven volume controlled electro-hydraulic servo system (DDVC system) has appearred, the hydraulic main circuit of this system (referring to Fig. 3) adopts closed oil circuit, two hydraulic fluid ports of its oil pump D3 connect two active chambers of piston type oil engine U3 respectively, also are provided with Fill valve (two Pilot operated check valve H31, H32) that is used for balance sysmte oil mass difference in volume of positive and negative when operation and the locking-valve (two Pilot operated check valve H33, H34) that is used to pin piston rod in system; Control the output flow of oil pump D3 and the flow direction of hydraulic oil by AC servo motor M3 during operation, and then the piston stroke of control oil engine U3.This system has the following advantages: 1) because hydraulic main circuit is a closed circuit, therefore system with oil mass seldom and be subjected to the outside contamination chance less only needs little fuel tank (oil tank) get final product, and does not have sensing element in the system, so also do not need to be equipped with filtrating equipment; 2) owing to do not have throttle element in the directly driven volume controlled electro-hydraulic servo system, pressure loss is very little, so the heat that oil pump when work produces seldom, and system can not need to be equipped with cooling system from heat radiation; When 3) system only work in actuator, just start AC servo motor, when system is in inoperative (the pressurize operating mode and the operating mode that dallies) consumed energy hardly during the cycle, its operating cost is very low.Therefore directly driven volume controlled electro-hydraulic servo system relative valve control oil engine electrohydraulic servo system cost is lower, but because the sensitivity of AC servo motor and oil pump combination will be lower than the sensitivity of electrohydraulic control, therefore the speed of response of this system is slower, can't be applied to the large steam turbine higher to the quick closing valve functional requirement.

In addition, because valve control oil engine electrohydraulic servo system and directly driven volume controlled electro-hydraulic servo system all adopt single control oil channel, so its control reliability is relatively poor, and is accidents caused because of the control oil channel fault easily.

The model utility content

At the defective that exists in the above-mentioned prior art, technical problem to be solved in the utility model provide a kind of with low cost, control reliability is high, and has the hydraulic control device of the oil engine of rapid response speed.

In order to solve the problems of the technologies described above, the hydraulic control device of a kind of oil engine provided by the utility model, comprise piston type oil engine, control unit and fuel tank, it is characterized in that: described control unit is formed in parallel by two direct drive type volume control loops, and each direct drive type volume control loop comprises an oil pump, an AC servo motor, an accumulator and a solenoid directional control valve; Described oil engine comprises first active chamber and second active chamber, described oil pump comprises first hydraulic fluid port and second hydraulic fluid port, first hydraulic fluid port of described oil pump is through a Pilot operated check valve, solenoid directional control valve connects first active chamber and the accumulator of oil engine respectively, it is first oil circuit, second hydraulic fluid port of described oil pump connects second active chamber of oil engine through a Pilot operated check valve, it is second oil circuit, described accumulator connects two active chambers of oil engine respectively through two snap switch solenoid valves, Pilot operated check valve in described first oil circuit and second oil circuit is used to lock the piston rod of oil engine, each connects fuel tank through a Pilot operated check valve two hydraulic fluid ports of described oil pump, be used for the repairing of oil circuit oil mass difference in volume when oil pump is positive and negative to be moved, described AC servo motor connects oil pump, be used to control the oil pump operation, described accumulator is provided with pressure switch, be used to control the accumulator accumulation of energy, second active chamber of described oil engine connects fuel tank through a snap switch solenoid valve.

The hydraulic control device of the oil engine that the utility model provides has following beneficial effect: 1) owing to adopted the double pump redundancy scheme, its control unit is formed in parallel by two direct drive type volume control loops, thereby has improved the control reliability of system; 2) owing to adopt the direct drive type volume control loop, therefore do not need to be equipped with separately constant pressure oil source, filtrating equipment and cooling unit, thereby its cost is lower; 3) in the direct drive type volume control loop, added accumulator, can make quick response to control signal, cooperated AC servo motor to realize the quick closing valve of system again by accumulator.

Description of drawings

Fig. 1 is the schematic diagram of hydraulic control device of the utility model embodiment's oil engine;

Fig. 2 is the schematic diagram of existing valve control oil engine electrohydraulic servo system;

Fig. 3 is the schematic diagram of existing directly driven volume controlled electro-hydraulic servo system.

Embodiment

Below in conjunction with description of drawings embodiment of the present utility model is described in further detail, but present embodiment is not limited to the utility model, every employing analog structure of the present utility model and similar variation thereof all should be listed protection domain of the present utility model in.

As shown in Figure 1, the hydraulic control device of a kind of oil engine that the utility model embodiment is provided, comprise piston type oil engine U1, control unit and fuel tank X1, X2, X3, it is characterized in that: described control unit is formed in parallel by two direct drive type volume control loops, and each direct drive type volume control loop comprises an oil pump D1 (D2), an AC servo motor M1 (M2), an accumulator N1 (N2) and a solenoid directional control valve H11 (H21); Described oil engine U1 comprises first active chamber and second active chamber, described oil pump D1 (D2) comprises first hydraulic fluid port and second hydraulic fluid port, first hydraulic fluid port of described oil pump D1 (D2) is through a Pilot operated check valve H14 (H24), solenoid directional control valve H11 (H21) connects first active chamber and the accumulator N1 (N2) of oil engine U1, it is first oil circuit, second hydraulic fluid port of described oil pump D1 (D2) connects second active chamber of oil engine U1 through a Pilot operated check valve H15 (H25), it is second oil circuit, described accumulator N1 (N2) is respectively through two snap switch solenoid valve H12, H13 (H22, H23) two active chambers of connection oil engine U1, Pilot operated check valve H14 in described first oil circuit and second oil circuit, H15 (H24, H25) be used to lock the piston rod of oil engine U1, two hydraulic fluid ports of described oil pump D1 (D2) are respectively through a Pilot operated check valve H16, H17 (H26, H27) connect fuel tank X1 (X2), the repairing of oil circuit oil mass difference in volume when being used for the positive and negative operation of oil pump D1 (D2), described AC servo motor M1 (M2) connects oil pump D1 (D2), be used to control oil pump D1 (D2) operation, described accumulator N1 (N2) is provided with pressure switch K1 (K2), be used to control accumulator N1 (N2) accumulation of energy, second active chamber of described oil engine U1 connects fuel tank X3. through a snap switch solenoid valve H18

Described fuel tank X1, X2, X3 communicate with each other.

The workflow of the hydraulic control device of the utility model embodiment's oil engine is as follows:

When utilizing oil pump D1 control oil engine U1, start AC servo motor M1 earlier and drive oil pump D1 operation, snap switch solenoid valve H12, H13, H18 energising are ended, and second load port of connecting solenoid directional control valve H11 is oil-filled to accumulator N1, after the oil pressure of accumulator N1 reaches predetermined pressure, switch to first load port, make system enter readiness for operation by pressure switch K1 control solenoid directional control valve H11;

When needing oil engine U1 action, send control signal and give AC servo motor M1, AC servo motor M1 is according to the traffic direction of control signal control oil pump D1, thereby the piston rod of control oil engine U1 acts accordingly;

When needing quick control, control signal control AC servo motor M1 connects corresponding snap switch solenoid valve H12 or H13 outage in the time of operation, oil among the accumulator N1 is released in the oil circuit through corresponding snap switch solenoid valve H12 or H13, thereby control oil engine U1 makes quick response action; When snap switch solenoid valve H12 outage is connected, snap switch solenoid valve H18 outage is connected, make oil engine U1 can make response action faster;

During system maintenance, snap switch solenoid valve H13, the H18 connection of cutting off the power supply, oil is released among the fuel tank X3 among the accumulator N1 thereby make;

Utilize workflow and the oil pump D1 of oil pump D2 control oil engine U1 similar.

The hydraulic control device of the utility model embodiment's oil engine can adopt single pump control when moving, also can adopt double pump control.

Claims

1. the hydraulic control device of an oil engine, comprise piston type oil engine, control unit and fuel tank, it is characterized in that: described control unit is formed in parallel by two direct drive type volume control loops, and each direct drive type volume control loop comprises an oil pump, an AC servo motor, an accumulator and a solenoid directional control valve; Described oil engine comprises first active chamber and second active chamber, described oil pump comprises first hydraulic fluid port and second hydraulic fluid port, first hydraulic fluid port of described oil pump is through a Pilot operated check valve, solenoid directional control valve connects first active chamber and the accumulator of oil engine respectively, it is first oil circuit, second hydraulic fluid port of described oil pump connects second active chamber of oil engine through a Pilot operated check valve, it is second oil circuit, described accumulator connects two active chambers of oil engine respectively through two snap switch solenoid valves, Pilot operated check valve in described first oil circuit and second oil circuit is used to lock the piston rod of oil engine, each connects fuel tank through a Pilot operated check valve two hydraulic fluid ports of described oil pump, be used for the repairing of oil circuit oil mass difference in volume when oil pump is positive and negative to be moved, described AC servo motor connects oil pump, be used to control the oil pump operation, described accumulator is provided with pressure switch, be used to control the accumulator accumulation of energy, second active chamber of described oil engine connects fuel tank through a snap switch solenoid valve.