Abstract: A method and system for the hydraulic control of a concrete placing boom (14) comprising a plurality of boom arms (16), wherein hydraulic drive cylinders (18) for the boom arms (16), which are connected to one another in an articulated manner, are controlled by a hydraulic circuit (34), wherein a supply pressure is supplied via a hydraulic pump (32) to the hydraulic circuit (34), and wherein a pressure signal is captured in the drive cylinders (18) by at least one pressure sensor (38) for each cylinder. The maximum pressure in the drive cylinders (18) is determined from the pressure signals and the supply pressure is adjusted by an electronic control unit (36) according to the maximum pressure.

Abstract: A method and system for the hydraulic control of a concrete placing boom (14) comprising a plurality of boom arms (16), wherein hydraulic drive cylinders (18) for the boom arms (16), which are connected to one another in an articulated manner, are controlled by a hydraulic circuit (34), wherein a supply pressure is supplied via a hydraulic pump (32) to the hydraulic circuit (34), and wherein a pressure signal is captured in the drive cylinders (18) by at least one pressure sensor (38) for each cylinder. The maximum pressure in the drive cylinders (18) is determined from the pressure signals and the supply pressure is adjusted by an electronic control unit (36) according to the maximum pressure.

Abstract: A manipulator for concrete pumps having an articulated boom with at least two boom arms and a hydraulic drive that pivots one or more of the boom arms. A hydraulic cylinder has piston and rod side working volumes. A hydraulic circuit has a first switching state in which the hydraulic circuit connects a first working port for feed or discharge of hydraulic fluid to the rod-side working volume and connects a second working port for feed or discharge of hydraulic fluid to the piston-side working volume. In a second switching state, the hydraulic circuit separates the first working port from the first fluid channel and thereby connects the first fluid channel to the second fluid channel for the feed of hydraulic fluid from the rod-side to the piston side working volume. A sensor acquires an operating state variable based upon which an activation assembly sets the switching state.

Abstract: A manipulator for concrete pumps having an articulated boom with at least two boom arms and a hydraulic drive that pivots one or more of the boom arms. A hydraulic cylinder has piston and rod side working volumes. A hydraulic circuit has a first switching state in which the hydraulic circuit connects a first working port for feed or discharge of hydraulic fluid to the rod-side working volume and connects a second working port for feed or discharge of hydraulic fluid to the piston-side working volume. In a second switching state, the hydraulic circuit separates the first working port from the first fluid channel and thereby connects the first fluid channel to the second fluid channel for the feed of hydraulic fluid from the rod-side to the piston side working volume. A sensor acquires an operating state variable based upon which an activation assembly sets the switching state.

Abstract: The invention relates to a hydraulic drive system for a belt conveyor with a motor-driven primary pump which is arranged in a hydraulic primary circuit and is intended for conveying hydraulic fluid, a hydraulic motor which is supplied with hydraulic fluid via the primary circuit and is intended for driving the belt conveyor, and a control device which influences the flow of hydraulic fluid in the primary circuit and is intended for controlling the belt speed of the belt conveyor. In exemplary embodiments, the primary pump is a variable displacement pump and has a pump regulator for regulating the conveyed flow of hydraulic fluid, and the control device comprises a hydraulic control circuit, which is operated by means of an auxiliary pump, for subjecting the pump regulator to an adjustable actuating pressure.

Abstract: The invention relates to a hydraulic drive system for a belt conveyor with a motor-driven primary pump which is arranged in a hydraulic primary circuit and is intended for conveying hydraulic fluid, a hydraulic motor which is supplied with hydraulic fluid via the primary circuit and is intended for driving the belt conveyor, and a control device which influences the flow of hydraulic fluid in the primary circuit and is intended for controlling the belt speed of the belt conveyor. In exemplary embodiments, the primary pump is a variable displacement pump and has a pump regulator for regulating the conveyed flow of hydraulic fluid, and the control device comprises a hydraulic control circuit, which is operated by means of an auxiliary pump, for subjecting the pump regulator to an adjustable actuating pressure.

Abstract: A device and a method for controlling a two-cylinder thick matter pump to achieve a reliable operation even of single-circuit two-cylinder thick matter pumps. To this end, the pipe switch includes a position transmitter responding to the pivoting position. At least two cylinder switching sensors are arranged on the working cylinders at a distance from each other, responding to the passing pistons of the drive cylinder, and/or a pressure sensor responding to the pressure course at the high-pressure outlet of the reversible pump is provided. A computer-assisted reversing device has a control routine responding to output signals of the position transmitter and to output signals of the cylinder switching sensors and/or the pressure sensors, enabling the programmed control of a control body for adjusting the flow quantity and direction of the reversible pump, and a reversing element arranged in the hydraulic branch of the pipe switch.

Abstract: The invention relates to a hydraulic circuit arrangement, in particular for the drive of concrete distributor masts. The circuit arrangement comprises at least one hydraulic load (34, 35, . . . ), the latter being connected at the inlet side by means of a feed line (64) to the pressure outlet of a hydraulic positive displacement pump (60), and comprises at least one proportional valve (56) which is arranged in the feed line (64), is assigned one of the loads and, in its rest position, blocks the feed line (64), and in an operating position, forms a throttle aperture (57) with a variable opening cross section. Also provided in the feed line (64) is a reversing group (82), which in the standby state is connected to the tank (62) and in the operating position is connected to the at least one load (34, 35, . . . ).

Abstract: A device and a method for controlling a two-cylinder thick matter pump comprising delivery pistons that are actuated by means of a hydraulic reversible pump (6) via hydraulic drive cylinders that are controlled by said pump in a push-pull manner. For each pressure stroke, the delivery cylinders (50, 50?) are connected to a delivery conduit (58) by means of a pipe switch (56). At the end of each delivery stroke, a reversal process of the pipe switch (56) and the reversible pump (6) is triggered. The aim of the invention is to achieve a reliable operation even of single-circuit two-cylinder thick matter pumps. To this end, the pipe switch comprises a position transmitter responding to the pivoting position thereof.

Abstract: In a thick matter pump, especially for delivering concrete, comprising two delivery cylinders, it is known to provide two position sensors in one of the two cylinders for control of the pistons. However, leakage of hydraulic fluid can lead to an imbalance of the two cylinders. In the invention two position sensors (52?, 52?) are provided, which are arranged at a defined distance from one of the ends of the drive cylinders and which respond to a drive piston (30?, 30?) that is passing by. To prevent the formation of concrete clots inside the delivery cylinders (10) and to prevent the occurrence of a slamming when the drive pistons (30?, 30?) reach their end of travel, the invention provides that both position sensors (52?, 52?) are arranged at a distance from the piston rod-side ends of both drive cylinders (24?, 24?) and, in addition, a correcting sensor (54) is arranged at a defined distance from the piston head-side end of one of the drive cylinders (24?).