Abstract: The invention relates to a boom arm for mobile concrete pumps and to a mobile concrete pump. The boom arm, having a first and second end, wherein at least one elbowed section, in which the main bending loads which occur during proper use act as torsional loads, is provided between the first and the second end of the boom arm, is made from a fiber composite material, wherein beyond the elbowed region the height of the boom arm in cross-section is greater than the width of the boom arm in cross-section and in the elbowed region the width of the boom arm in cross-section is greater than or equal to the height of the boom arm in cross-section. A concrete pump with a placing boom, arranged on a substructure, comprising at least two boom arms, at least one of which is designed according to the invention.

Abstract: A method for operating a hybrid vehicle having a prime mover including an internal combustion engine and an electric machine, the vehicle further having a transmission connected between the prime mover and a driven end and including multiple shift elements, the vehicle further having a separating clutch connected between the internal combustion engine and the electric machine, and a starting component which is provided by a separate launch clutch or by a shift element of the transmission. The method includes monitoring a rotational speed of one of the internal combustion engine, the electric machine, the transmission, or the driven end during travel with the internal combustion engine running and the separating clutch engaged. The method further includes determining an increase in driving resistance, and decoupling the internal combustion engine when the monitored rotational speed falls below or reaches a first limiting value by disengaging the separating clutch.

Abstract: A method for operating a drive train of a motor vehicle with a prime mover (1) including an internal combustion engine (2) and an electric machine (3), a separating clutch (6) connected between the internal combustion engine and the electric machine, and a transmission (5) connected between the prime mover (1) and a driven end (4) is provided. When at least one first operating condition is present, a previously decoupled internal combustion engine (2) is coupled such that the separating clutch (6) is actuated to engage. When at least one second operating condition is present, the coupling of the internal combustion engine is aborted, and an absolute value of a torque currently transmitted or currently transmittable by the separating clutch (6) is determined. The separating clutch (6) is disengaged at different rates depending on the absolute value of the torque currently transmitted or currently transmittable by the separating clutch (6).

Abstract: A method for operating a drive train of a motor vehicle with a prime mover (1) including an internal combustion engine (2) and an electric machine (3), a separating clutch (6) connected between the internal combustion engine and the electric machine, and a transmission (5) connected between the prime mover (1) and a driven end (4) is provided. When at least one first operating condition is present, a previously decoupled internal combustion engine (2) is coupled such that the separating clutch (6) is actuated to engage. When at least one second operating condition is present, the coupling of the internal combustion engine is aborted, and an absolute value of a torque currently transmitted or currently transmittable by the separating clutch (6) is determined. The separating clutch (6) is disengaged at different rates depending on the absolute value of the torque currently transmitted or currently transmittable by the separating clutch (6).

Abstract: A method for operating a hybrid vehicle includes monitoring, a rotational speed of an internal combustion engine (2) or a rotational speed of an electric machine (3) or a rotational speed of a transmission (4) or a rotational speed of a driven end (5) during travel with the internal combustion engine (2) running and the separating clutch (7) engaged in order to determine an increase in driving resistance. The method also includes, when the monitored rotational speed falls below or reaches a first limiting value, partially disengaging the separating clutch (7) toward a disengagement position in which a torque transmitted by the separating clutch (7) is adjusted such that an idling speed governor of the internal combustion engine (2) accelerates the rotational speed of the internal combustion engine toward the idling speed of the internal combustion engine (2).

Abstract: A method for operating a hybrid vehicle having a prime mover including an internal combustion engine and an electric machine, the vehicle further having a transmission connected between the prime mover and a driven end and including multiple shift elements, the vehicle further having a separating clutch connected between the internal combustion engine and the electric machine, and a starting component which is provided by a separate launch clutch or by a shift element of the transmission. The method includes monitoring a rotational speed of one of the internal combustion engine, the electric machine, the transmission, or the driven end during travel with the internal combustion engine running and the separating clutch engaged. The method further includes determining an increase in driving resistance, and decoupling the internal combustion engine when the monitored rotational speed falls below or reaches a first limiting value by disengaging the separating clutch.

Abstract: A method for operating a drive train includes determining target torques for prime movers (1, 2) at least depending on a driver-demanded output torque. When a form-locking shift element (9) is disengaged for a gearchange, the shift element (9) to be disengaged is relieved of load, via an actuation of the prime movers depending on the target torques. The shift element (9) to be disengaged is already actuated with a defined actuating pressure in the direction of disengagement before a theoretical relief from load depending on the target torques, and monitoring determines whether and at which actual torques the shift element (9) to be disengaged begins to move. The actual torques of the prime movers (1, 2), at which the shift element (9) to be disengaged begins to move, are determined as actual torques at which the shift element (9) to be disengaged is actually relieved of load.