Abstract:
Offenbart ist eine Hydraulikanordnung mit zumindest einer Verstellpumpe (4, 6). Diese wird von einem Pumpenregler (8, 10) in Abhängigkeit eines Solldrucks eingestellt. Die zumindest eine Verstellpumpe dient zur Versorgung zumindest eines Verbrauchers mit einer Druckmittelmenge. Des Weiteren ist ein Vergleichsventil (12, 14) vorgesehen, über das der Ausgangsdruck ab einem bestimmten Druckunterschied zum Solldruck abgebaut wird. D. h., übersteigt der Ausgangsdruck den Solldruck um einen vorbestimmten Wert, dann wird der Ausgangsdruck direkt oder indirekt über das Vergleichsventil gemindert.
Abstract translation:公开的是具有至少一个可变排量泵(4,6)的液压装置。 这是通过一个泵调节器(8,10)在上设定点压力的依赖性被设定控制。 所述至少一个可变排量泵用于与压力流体的数量提供至少一个使用者。 此外,比较阀(12,14)设置,通过该输出压力从一定的压力差减小到目标压力。 D. H中,出口压力超过一预定值的目标压力,输出压力是通过比较阀直接或间接地减少。
Abstract:
A two-stage pressure relief valve for use with hydraulic systems is disclosed. The two-stage pressure relief valve has a first stage that relieves increases in hydraulic system pressure over the normal operating pressure and up to a selected threshold pressure level, and a second stage that brings the hydraulic system pressure down to a selected reduced operating pressure that is below the normal operating pressure in response to increases in the operating pressure over the threshold pressure level.
Abstract:
A power machine (10) includes one or more steerable wheels (14). The wheels (14) are steerable using a hydraulic actuator (202, 204) to drive steering movement of the wheels (14). The power machine (10) also includes steering angle sensors (302, 304) which sense the steering angle and provide a signal indicative of the angle at which the wheels (14) are disposed relative to a longitudinal axis of the power machine (10). A hydraulic control system controls pressure of hydraulic fluid provided to the steering actuators (202, 204) based upon the steer angle position and desired change in position over time sensed by the steer angle sensors (302, 304).
Abstract:
A slew working vehicle (1) is equipped with a left traveling motor (13) and a right traveling motor (14) both for driving left and right traveling devices (2L, 2R) and controls the traveling motors (13, 14) independently with left and right hydraulic directional control valve (15, 16). A throttle valve(55)is provided in a pilot oil passage (54) to allow the oil path to pass in series through the hydraulic directional control valves (15, 16) downstream of the throttle valve (55) and to connect with a drain oil passage (30). This vehicle is also provided with a travel-alarming pressure switch (61) which operates by the pilot oil preessure which is the oil pressure in the pilot oil passage (54) between the throttle valve (55) and the upstream one of the left and right hydraulic control valves (15, 16).
Abstract:
The invention relates to a hydraulic control arrangement for the demand-feed regulated hydraulic fluid supply of preferably several hydraulic consumers which are provided with proportionally adjustable directional control valves (12). A required amount of hydraulic fluid can be delivered by two hydraulic pumps (30, 31) via a common supply line leading to the directional control valves. A first demand-feed regulator (45) is associated with the first hydraulic pump (30) and a second demand-feed regulator (46) is associated with the second hydraulic pump (31). A return valve (36) which opens into the feed line is mounted between the first hydraulic pump (30) and the feed line (26). According to the invention, a return valve (37) that opens into the feed line (26) is also arranged between the second hydraulic pump (31) and the feed line (26). Means (90, 91, 95, 96) for regulating the power use of the demand-feed regulator (45, 46) are provided, whereby said means can be modified in such a way that the hydraulic consumers can be exclusively supplied with hydraulic fluid by the first hydraulic pump (30) or the second hydraulic pump (31).
Abstract:
A hydraulic circuit (10) for controlling the speed of multiple hydraulic fluid power devices (18, 20) when the flow demand of the devices (18, 20) exceeds the flow capacity of a pressure source (6) supplying hydraulic fluid under pressure to the devices (18, 20) has multiple pressure controlled proportional flow supply valves (24) for controlling the supply of hydraulic fluid to the power devices (18,20). Load sense pressures which indicate the pressure delivered by the valves (24) to the corresponding devices (18, 20) are compared to determine the highest load sense pressure, which is compared to the supply pressure by a proportional speed sensing valve (94) to regulate the pilot pressure. In the preferred embodiment, the pilot pressure is regulated by the proportional speed sensing valve (94) to be equal to the differential between the supply pressure and the highest load sense pressure, and a limit control (231, 247) is provided in one form (215) of the proportional speed sensing valve. Thus, when the differential between supply pressure and the highest load sense pressure starts falling, as occurs when the flow demand exceeds the flow capacity of the pump (6) the pilot pressure is reduced, which reduces flow to the power devices (18, 20) proportionally to reduce the speeds of the devices (18, 20) while maintaining substantially constant the proportions of the speeds to one another.
Abstract:
Simultaneous operation efficiency in a case where a plurality of actuators are operated by one or a plurality of hydraulic pumps is improved. A delivery pressure passage (1a) of one hydraulic pump (1) and that (1a) of the other hydraulic pump (1) communicate with each other through a first short-circuit passage (39) via a pair of check valves (38, 38), and an unload valve (40) is provided in this first short circuit passage (39). The load pressure introduction passages (6, 6) on the left and right hydraulic pumps (1, 1) side communicate with each other through a second short circuit passage (36) via a pair of check valves (35, 35), and a relief valve (37) is provided in this short circuit passage (36). The unload valve (40) is unloaded by the differential pressure between the pump delivery pressure in the first short circuit passage (39) and the load pressure in the second short circuit passage (36), whereby a single relief valve (37) carries out a relieving operation both in the flow merging time and current branching time to equalize the maximum pump delivery pressures. The set pressure of the relief valve (37) can be a high level so as to relieve the valve (37) under a predetermined high load pressure and so as not to relieve the same, whereby the relieving operation can be arbitrarily controlled.
Abstract:
A hydraulic circuit (38, 54) may be used for controlling a plurality of hydraulic implements (36, 50, 52). The hydraulic circuit (38, 54) may include a first directional valve (66), a second directional valve (64), and a relief valve. A variable displacement pump (42) (42) may be fluidly coupled to the first directional valve (66), the second directional valve (64), and the relief valve. The hydraulic circuit (38, 54) may be communicably and operably coupled to a controller, and the controller (56) may be programmed to selectably control the hydraulic circuit (38, 54) between a first operational mode (60) and a second operational mode (62). Additionally, the controller (56) may be programmed to actuate the first directional valve (66) between an open position and a closed position and to actuate the second directional valve (64) between a first open position, a second open position, a first closed position and a second closed position.
Abstract:
본 발명의 실시예는 굴삭기의 압력피크 저감밸브에 관한 것으로, 굴삭기용 압력피크 저감밸브는 유암펌프로부터 토출되는 작동유가 유입되는 유입구가 단부에 형성되고, 유압 탱크와 연통되는 연통공이 외주면에 적어도 하나 이상 형성되는 포펫 시트와, 상기 포펫 시트의 내부에서 슬라이딩 되는 메인 포펫와, 상기 메인 포펫의 내부에 마련되는 포펫 스프링와, 상기 포펫 스프링의 일단부와 접촉하도록 그 일단부가 상기 메인 포펫에 삽입되는 밸브 시트와, 상기 밸브 시트의 단부에 형성되는 개폐공에 삽입되도록 마련되는 콘과, 상기 밸브 시트의 내부에 마련되는 조정 스크류, 및 상기 조정 스크류의 내부에서 슬라이딩 되는 피스톤을 포함한다.