Abstract:
The present invention ensures that an element (13) that prevents falling of the load by entrapment of the hydraulic fluid within a hydraulic cylinder also functions as discharging the entrapped hydraulic fluid in order to assure the lowering operation at the same time. As the said novelty in the system shall also function as the load retainer check valve, it is possible to achieve very low leak rates without employing any lowering valve or system or without reducing the diametric gap between the spool and the body.
Abstract:
게시된 발명은, 도저 블레이드 작업장치 작동시 외부 부하에 의하여 발생하는 압력하강에 대응하여 체크가 미리 설정된 소정의 시차를 가지고 개폐되도록 함으로써, 소음 및 헌팅 현상이 크게 저감될 수 있도록 개량된 건설기계용 더블 체크밸브에 관한 것으로, 유압펌프와, 상기 유압펌프에 연결되고, 작업장치를 구동시키는 유압실린더와, 상기 유압펌프와 상기 유압실린더 사이의 유로에 설치되고, 절환시 유압실린더의 기동, 정지 및 방향전환을 제어하는 콘트롤밸브와, 상기 콘트롤밸브와 상기 유압실린더 사이의 제1유로와 제2유로를 개폐하도록 피스톤 실린더 일측에 설치되고, 각각 플런저 접지부 및 노치부를 구비하며 상기 작업장치의 일시적인 하강시 상기 유로 중 어느 하나로 부터 도입되는 신호압이 체크수압부에 작용시 서로 반대방향으로 절환되도록 분할형성되는 한쌍의 피스톤과, 상기 피스톤의 절환에 의해 가압되어 체크기능이 각각 해제되는 한쌍의 체크밸브 및 상기 피스톤 실린더 내부에 설치되며, 상기 노치부를 통과한 유량이 상기 피스톤 접지부에 압력을 형성함에 따라서 상기 피스톤을 상기 체크밸브의 체크기능 해제방향으로 이동시키는 플런저를 포함하여 구성되는 것을 특징으로 한다.
Abstract:
Offenbart ist ein stetig verstellbares Wegeventil mit einem Sitzschieber, an dem ein Ventilkegel ausgebildet ist, der in der Grundposition des Wegeventils gegen einen Ventilsitz vorgespannt ist. Das Wegeventil ist mit einer Vorsteuerung ausgebildet, wozu im Schliesskegel ein Vorsteuerventilsitz vorgesehen ist, der mit einem Vorsteuerventilkegel zusammenwirkt.
Abstract:
An assembly of a pair of electrically operated bidirectional proportional control valves (36,38) and a four-way direction control valve (30) governs the flow of fluid to and from a hydraulic cylinder (16). The four-way direction control valve alternately connects a pump supply line (12) to one of a pair of intermediate conduits (32,34) and a tank return line (14) to the other intermediate conduit. That connection determines the direction of movement of the cylinder piston (16). The intermediate conduits are coupled to chambers (22,26) of the cylinder by a separate one of the proportional control valves which meters the fluid flow to or from the respective chamber. Thus the proportional control valves control the rate of piston movement.
Abstract:
The invention relates to a pipe breakage safety valve with an internal servo-valve (1) having a piston (4) which in one position on a control edge (6) blocks the connection between two internal pressure unions (2, 3) of the servo-valve. At an axial distance from said control edge, the valve piston has another control edge (8) which fluidtightly separates from the pressure unions a preloading spring (5) of the valve piston or a spring chamber (9) containing said spring.
Abstract:
A screw-in valve has an essentially tubular screw part (2) provided with an outer thread (4) for threading into a valve housing and a flange (3) formed in one-piece with the screw-in part (2) and adjacent thereto, provided with a central bore (6) for a valve rod (7). The bore (6) of the flange (3) has an inner thread (8) for receiving an essentially tubular housing (10), provided at its end with an outer thread (9), of an actuator (11) that acts on the valve rod (7) in the axial direction, and/or the screw-in part (2) has an inner thread (21) for screwing onto an exchangeable, essentially tubular valve seat body (24).
Abstract:
A load lock valve (72) for a hydraulic system (44) is disclosed. The load lock valve may have a block (63) with a first bore (88), and a body (90) disposed within the first bore. The body may have a second bore (82), and first and second first radial ports (96, 98) in fluid communication with the second bore. The body may also have a valve seat (100), and a poppet (74) disposed within the body. The poppet may have a nose end (102), a control end (104), a balance passage (80) extending from the control end toward the nose end and terminating short of the nose end, and a third radial port (106) in fluid communication with the balance passage. The load lock valve may further have spring (78) configured to bias the poppet toward the first opening. The control end of the poppet is fluidly communicated with the first radial port when a sealing surface at the nose end is against the valve seat.
Abstract:
Ein Proportional-Drosselventil mit einem Ventilkolben (2), der in einem Ventilgehäuse (3) mit einem Fluideinlaß (4) und einem Fluidauslaß (5) in Längsrichtung verschiebbar geführt ist und der durch einen Energiespeicher, insbesondere in Form einer Druckfeder, gegen einen die Schließposition definierenden Hubanschlag (6) vorgespannt ist, dadurch gekennzeichnet, dass in dem Proportional-Drosselventil (1) ein Druckbegrenzungsventil (7) integriert ist, mit Hilfe dessen der Fluiddruck auf der Rückseite (8) des Ventilkolbens (2) im Sinne eines gegen die Vorspannung erfolgenden Entfernens vom Hubanschlag (6) bei Überschreiten eines vorgebbaren Druckes am Fluideinlaß (4) beeinflußt ist.
Abstract:
Offenbart ist eine Ventilanordung zur Ansteuerung eines Verbrauchers (116) und ein Verfahren zur Ansteuerung der Ventilanordnung, bei denen eine Zulauf-Drosseleinrichtung (4) und eine Ablauf-Drosseleinrichtung (6, 8) unabhängig voneinanderan steuerbar sind. Bei einfach wirkenden Verbrauchern wird die Ablauf-Drosseleinrichtung (6) derart angesteuert, dass bei Erreichen des gewünschten Hydrauliköl-Volumenstromes der Öffnungsquerschnitt der Ablaufdrossel (6) maximal ist, so dass die Energieverluste in der Ablaufleitung (120) auf ein Minimum reduziert sind.