摘要:
The invention relates to a hydraulic winch control, comprising a variable displacement motor (12) supplied with a pressure agent via a directional control valve (35) for driving the winch (10). Said directional control valve (70) is controlled via a control valve that is functionally linked with an adjusting lever (81). In a mooring operation, the directional control valve is subjected to a predetermined actuating pressure difference so that the flow of pressure agent to the variable displacement motor is reduced.
摘要:
The invention relates to a method for producing ground surfaces using a construction machine (1), especially a hydraulic excavator. Said construction machine comprises excavating equipment (2, 5, 7) which consists of one part or of multiple parts and which is equipped with a shovel (7) that can be placed on the ground surface. The construction machine also comprises a lifting cylinder (3) for lifting and lowering said excavating equipment. The lifting cylinder (3) of the excavating equipment is operationally connected to at least one work pump (9) via a control device (17, 8) that can be operated by a driver. In order to effect a weight compensation of the excavating equipment (2, 5, 7) and to adjust an approximately constant application force of the shovel (7) on the ground surface, the lifting side of the lifting cylinder (3) is, after actuating an operating element (16, 18), automatically subjected to the action of the adjustable compensating pressure of the pump (29) by supplying or evacuating the hydraulic medium.
摘要:
A pressure control valve 1 for supplying a pressure fluid, the pressure of which has been regulated, to a supply passage 61 in a solenoid valve aggregate 6 formed of a plurality of solenoid valves 60 arranged said by side in a line. tHE VALVE 1 is placed between a supply-exhaust block 5 for supplying and discharging a pressure fluid from and to the outside and the solenoid valve aggregate 6. A control valve body 10 of the pressure control valve 1 is provided with an input port in communication with a supply port 51 of the supply-exhaust block 5, an output port in communication with a supply passage 61 installed through the solenoid valve aggregate 6, a pressure regulating mechanism which regulates the pressure of the pressure fluid supplied from the supply port 51 and outputs a secondary pressure to the supply passage 61 of the solenoid valve aggregate 6 through the output port, and an exhaust passage that directly links a discharge passage of the solenoid valve aggregate 6 and an exhaust port 52 of the supply-exhaust block.
摘要:
An improved pressure-compensated hydraulic system for feeding hydraulic fluid from a variable displacement pump (18) to multiple hydraulic actuators (20). A separate valve section (13,14,15) controls the fluid flow between the pump (18) and a different actuator (20). Each valve section (13,14,15) has a pressure compensating valve (48) with a valve member (64) and poppet (60) within a bore (62) and biased apart by a spring. The poppet (60) acts as a check valve which prevents fluid flow from the actuator (20) through the valve section (13,14,15) to the pump (18) when the back pressure from the load exceeds the pump supply pressure. A pressure differential between the load-dependent pressure and the actuator pressure determines a position of the valve member (64) which controls the pressure applied to the pump pressure control input (32).
摘要:
Die Erfindung betrifft eine lastdruckunabhängige Steuerung der Geschwindigkeit von hydraulischen Stellelementen (3) bei vorauseilenden Lasten, insbesondere an Baumaschinen, mit mindestens einer Pumpe (17), mindestens einem Steuerschieber (4) sowie mindestens einer Druckwaage (11). Die Druckwaage (11) ist entweder in die Verbindungsleitung (6) des kontrolliert zu entleerenden Raumes (2) des als Hydraulikzylinder ausgebildeten Stellelementes (3) zum Steuerschieber (4) oder aber in die Leitung (7) zwischen dem Ausgang des Steuerschiebers (4) und dem Tank (9) eingesetzt. Der Rücklaufbereich des zugehörigen Steuerkolbens (5) ist als Differenzdruckblende (8) ausgebildet. Die Druckmeldung vor dem Durchtritt des Ölstromes durch die Differenzdruckblende (8) an die Druckwaage (11) ist über eine Leitung auf die der Federkammer (14) abgewandten Seite der Druckwaage (11) herbeiführbar.
摘要:
Die Erfindung betrifft eine lastdruckunabhängige Steuerung der Geschwindigkeit von hydraulischen Stellelementen (3) bei vorauseilenden Lasten, insbesondere an Baumaschinen, mit mindestens einer Pumpe (17), mindestens einem Steuerschieber (4) sowie mindestens einer Druckwaage (11). Die Druckwaage (11) ist entweder in die Verbindungsleitung (6) des kontrolliert zu entleerenden Raumes (2) des als Hydraulikzylinder ausgebildeten Stellelementes (3) zum Steuerschieber (4) oder aber in die Leitung (7) zwischen dem Ausgang des Steuerschiebers (4) und dem Tank (9) eingesetzt. Der Rücklaufbereich des zugehörigen Steuerkolbens (5) ist als Differenzdruckblende (8) ausgebildet. Die Druckmeldung vor dem Durchtritt des Ölstromes durch die Differenzdruckblende (8) an die Druckwaage (11) ist über eine Leitung auf die der Federkammer (14) abgewandten Seite der Druckwaage (11) herbeiführbar.
摘要:
A method of controlling the slewing operation of a slewing mechanism for slewing the revolving superstructure of a hydraulic backhoe or the like. The method comprises setting a swing mode selector valve (2) in a driving position to supply a working fluid discharged from a hydraulic pump (1) through a supply-and-discharge line to a hydraulic motor (3) to drive the hydraulic motor for a driving operation, setting one of a pair of relief valves (4a, 4b) provided between the swing mode selector valve and the hydraulic motor, associated with the supply side of the hydraulic motor for a set relief pressure higher than the set relief pressure of a main relief valve (12) for limiting the pressure in supply-and-discharge lines to the set relief pressure of the main relief valve while the hydraulic motor is operating in a driving mode, and setting the other relief valve associated with the discharge side of the hydraulic motor for a set relief pressure lower than the set relief pressure of the main relief valve to limit the pressure in the supply-and-discharge line associated with the discharge side of the hydraulic motor to the set relief pressure of the other relief valve while the hydraulic motor is operating in a braking mode. The method brakes the slewing mechanism smoothly to prevent the rapid abrasion of the braking surfaces of the components of the slewing mechanism.