摘要:
A method of controlling the stop of a hydraulic press, comprising the steps of controlling a servo-motor (37) by a rod pressure hold instruction part (67) to reversely rotate a bidirectional pump (29) so as to feed the hydraulic oil not exceeding a pressure caused by the self-weight of a ram (5U) to a bidirectional pump side pipe (49) in order to increase a pressure, and reducing a pressure difference between a pressure inside a pipe (43) for a speed selector valve (47) on the rod side cylinder cyamber side and a pressure inside a pipe (49) on the bidirectional pump side for the speed selector valve (47) to reduce a shock caused when the speed selector valve (47) is switched so as to stop the ram (5U) at a specified position.
摘要:
A control system (12, 70, 130, 160) for hydraulic circuit means (2, 64) having a variable displacement hydraulic pump (4, 60), and actuator means (6) driven by the pump, in which pump control means (22, 74. 164) controls a displacement volume varying member (8, 66) of the pump based on an operating signal (X L ) giving a command with respect to the position thereof and a detector signal (Y L ) indicative of the actual position thereof while restricting the operating speed of the member to a level below a predetermined maximum speed. The control system has maximum speed setting means (20, 72, 132. 162) previously setting a first predetermined maximum speed (a,) and a second predetermined maximum speed (a 2 . a3) higher than the first predetermined maximum speed for the operating speed of the variable displacement volume varying member (8, 66) and operative to select the first predetermined maximum speed (α 1 ) when the direction of operation of the actuator means (6) commanded by the operating signal agrees with the actual direction of operation thereof, and select the second predetermined maximum speed (α 2 , a3) when the position of the displacement volume varying member commanded by the operating signal is neutral or when the direction of operation of the actuator means commanded by the operating signal is opposite to the actual direction of operation thereof. The pump control means is constructed to effect the speed control of the displacement volume varying member based on the first or second predetermined maximum speed selected by the maximum speed setting means.
摘要:
A flow control system of a hydraulic pump for a construction machine is provided, which can variably control a discharge flow rate of the hydraulic pump in accordance with load pressure generated by a hydraulic actuator such as a boom cylinder. According to the flow control system of a hydraulic pump, the discharge pressure of the hydraulic pump and the operation rate of the operation lever for the hydraulic actuators is detected, and standard load pressures of the respective hydraulic actuators are set. If the discharge pressure of the hydraulic pump is higher than the preset standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is proportionally reduced for the same operation rate in accordance with degrees of loads generated by the hydraulic actuators, while if the discharge pressure of the hydraulic pump is lower than the standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is controlled in proportion to the operation rate.
摘要:
Erfindungsgemäß wird ein Verfahren zur Regelung einer Druckmittelzufuhr für einen hydraulischen Aktor (11) einer zyklisch arbeitenden Maschine bereitgestellt. Der Aktor wird von einer Verstellpumpe (13) mit einer Druckmittelmenge versorgt, wobei die Verstellpumpe von einem drehzahlgesteuerten Elektromotor (14) angetrieben wird. Der Druck bzw. die Druckmittelmenge wird von einem Pumpenregler (41) durch Ansteuern der Volumeneinstellung der Verstellpumpe geregelt. Das Verfahren weist einen Schritt des Erstellens eines Drehzahl-Profils zum Verändern der Drehzahl des Elektromotors (14) während eines Zyklus auf. Zudem ist ein Schritt des Ansteuerns der Drehzahl des Elektromotors (14) und der Volumeneinstellung der Verstellpumpe (13), bei dem innerhalb eines Zyklus der Maschine der Elektromotor (14) mit einem Vorgabewert für die Drehzahl gemäß dem erstellten Drehzahl-Profil angesteuert wird, vorgesehen. Es ist zudem ein Schritt des Ermittelns der Drehzahlabweichung (nl1,nl2) des Elektromotors (14) vorgesehen. Die Drehzahlabweichung ergibt sich aus der Abweichung der Drehzahl (n) des Elektromotors (14) von einem Sollwert (ns) für die Drehzahl. Der Schritt des Ansteuerns der Drehzahl des Elektromotors und der Volumeneinstellung der Verstellpumpe erfolgt in Abhängigkeit der ermittelten Drehzahlabweichung.
摘要:
A flow control system of a hydraulic pump for a construction machine is provided, which can variably control a discharge flow rate of the hydraulic pump in accordance with load pressure generated by a hydraulic actuator such as a boom cylinder. According to the flow control system of a hydraulic pump, the discharge pressure of the hydraulic pump and the operation rate of the operation lever for the hydraulic actuators is detected, and standard load pressures of the respective hydraulic actuators are set. If the discharge pressure of the hydraulic pump is higher than the preset standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is proportionally reduced for the same operation rate in accordance with degrees of loads generated by the hydraulic actuators, while if the discharge pressure of the hydraulic pump is lower than the standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is controlled in proportion to the operation rate.