Abstract: A friction wheel drive for an internal combustion engine's a unit belt drive for a secondary unit includes a control system, a friction wheel that engages frictionally with an outer side of a belt in a wrap-around portion of a drive wheel of the internal combustion engine and that is controlled by the control system to engage or disengage frictionally with a drive wheel of the secondary unit, and a guidance system having an arc section for guiding the movement of the friction wheel with the control system. The arc section is arranged equidistant from the axis of rotation of the drive or driven wheel relative to the driven wheel to the outside of the belt in the wrap-around portion for turning the secondary unit on and off.

Abstract: A belt drive for a secondary unit of an internal combustion engine includes a friction wheel drive having a friction wheel, a cam device for adjusting the engagement of the friction wheel to the drive wheel of the secondary unit, the cam device having a cam, a swivel arm by which the friction wheel is connected to the cam which is rotationally mounted on a side of the engine, and a spring biasing the swivel arm in a tension direction. The friction wheel is in permanent position of frictional engagement with a drive wheel of the secondary unit to drive the secondary unit and with an outside of a belt on a drive wheel of the internal combustion engine or of another secondary unit.

Abstract: A belt tensioning device for a continuous belt drive. The device includes a torsion spring assembly (20) with a longitudinal axis (A2) and with at least one torsion bar or torsion tube (32). The torsion spring assembly (20) can be clamped axially and in a rotationally fast way into a rack. A tensioning arm (19), at one end, is arranged at the torsion spring assembly (20) so as to be aligned approximately radially relative to the longitudinal axis (A2). A tensioning roller (15) is rotatably fixed at the other end of the tensioning arm (19). The axis of rotation (A1) of the tensioning roller (15) extends substantially parallel relative to the longitudinal axis (A2) of the torsion spring assembly (20), and the tensioning arm (19) can be resiliently supported relative to the rack so as to oscillate around the longitudinal axis (A2).

Abstract: A thermostatic valve arranged in the coolant circuit of an internal-combustion engine, has a main valve which is acted upon by cold coolant flow on the one side, and by hot coolant flow on the other side. The valve is actuated as a function of the coolant temperature by way of an expansion material element equipped with an electric heating device. To minimize the coldside influence onto the expansion material element, a capsule which stores the expansion material, has an end which limits the expansion material lower at the level of the closed main valve or on the mixing chamber side. At this end, a ring-shaped or sleeve-shaped heating element is arranged coaxially adjacent the control pin, or, individual heating elements are distributed along the circumference of the control pin in an adjacent manner.

Abstract: A method shuts down and switches on cylinders in a motor vehicle internal-combustion engine. Injection valves are controlled by an engine timing system as a function of vehicle operating conditions. The shutting-down of cylinders is carried out sequentially according to a defined program. Vehicle brakes can be acted upon in a power-operated manner. In order to prevent a switching jolt when shut-down cylinders are switched on again, when the cylinders are switched on again, the running up of the engine takes place in steps according to another defined program and a braking intervention is carried out.

Abstract: The invention concerns a device and method for cooling and preheating, especially of transmission fluid, of an internal combustion engine, with an equalization tank, with at least one radiator, which can be connected by means of an engine thermostat when a predetermined temperature is reached in the cooling loop, and with a water/oil heat exchanger. It is prescribed according to the invention that the forward stream (1) of a single water/oil heat exchanger (5) be branched off in the heating phase by means of a valve unit (3) essentially from the main cooling loop (12) of the internal combustion engine (17) and that its forward stream (1) in the cooling phase be taken by means of the same valve unit (3) essentially in the coolant side stream (13) from the low-temperature region (14) of the radiator (4) or a separate low-temperature cooler (14a) connected in the side stream after radiator (4, 4a).

Abstract: A cooling circuit includes a valve device (1, 1', 1") for a separate heat exchanger (42), especially of an internal combustion engine (48). To achieve a combined pressure limitation and pipe or hose break valve, a valve body (6, 35, 50), upon reaching a coolant throughput for maximum heat transfer in heat exchangers (42) located downstream, is actuated as a function of delivery pressure into an engaged position with a valve seat (5, 51). A throttle passage (7, 36, 52) maintains a coolant throughput that corresponds to maximum heat transfer. In the event of a pipe or hose break, the valve body (6, 35, 50) serving as part of a pipe or hose break is locked in a closed position.

Abstract: In order to control the temperature of the transmission oil of a motor vehicle driven by a liquid-cooled engine, a coolant/transmission oil heat exchanger is provided. The coolant stream supplied to the heat exchanger is miscible in a thermostatic valve from recooled and non-recooled coolant in order to achieve a desired temperature. Preferably the thermostatic valve is controlled by the temperature of the transmission oil, but it is also possible to have two expanding material elements as control pistons of the thermostatic valve, with one control piston being provided in the oil chamber of the thermostatic valve and the other control piston being provided in the coolant mixing chamber of the thermostatic valve. It is also possible, for purposes of precontrol, to electrically heat at least one of the control pistons.

Abstract: For a thermostatic valve in the coolant circulation system of an internal-combustion engine having an expansion material element penetrating the main valve for the cold-side stationary support and the hot-side driving connection with the valve disk of the main valve, it is provided for increasing the response characteristic of the thermostatic valve to act upon the expansion material element in the cold-side end section in addition by a hot coolant and/or to provide a metal film resistor as an electric heating device placed in the expansion material.

Abstract: A coolant temperature control system for an internal-combustion engine in a motor vehicle having an electrically heatable thermostatic valve whose method of operation can be shifted by electrical heating in the radiator operation direction. Control devices are provided for recognizing a defect of another system in the motor vehicle which controls the coolant flow. When a defect of this other system is recognized, the thermostatic valve is heated. Particularly when a defect is recognized, the heating of the thermostatic valve is controlled such that the coolant temperature is maintained below a preset coolant temperature threshold. Preferably, the recognition of a defect is carried out by means logically monitoring output signals of the other system.

Abstract: In a device for control of a motor vehicle engine operating at idle with two rows of cylinders, having a catalytic converter with an oxygen sensor associated with each, during operation of the engine at idle the injectors of one of the two rows of cylinders are alternately switched off. This switching of the injector shut-off from one row of cylinders to the other row of cylinders always takes place when the temperature of the catalytic converter associated with the row of cylinders that has just been shut-off falls below a predetermined temperature limit. Alternatively, in a device for control of a motor vehicle engine operating at idle with only one catalytic converter and only one oxygen sensor, during operation of the engine at idle the injectors are sequentially shut-off according to a predetermined program as a function of the engine firing order.

Abstract: In the case of a cooling system for an internal-combustion engine of a motor vehicle comprising a radiator and a thermostatic valve by means of which the temperature of the coolant can be controlled in a warm-up operation, a mixed operation and a radiator operation. The thermostatic valve containing an expansion element can be electrically heated for reducing the coolant temperature, the expansion element being designed such that the coolant temperature is controlled without any heating of the expansion element in the warm-up operation and/or the mixed operation to an upper operating limit temperature. In addition, a temperature switch is provided which, as a function of the coolant temperature detected at the or near the radiator outlet, releases the heating of the expansion element as required in order to shift the method of operation of the cooling system toward the radiator operation.

Abstract: In the case of a cooling system for an internal-combustion engine of a motor vehicle comprising a radiator and a thermostatic valve equipped with an electrically heatable expansion element, it is provided that, by means of three comparison stages which are connected in parallel, specifically a speed comparison stage, a load condition comparison stage and an intake air temperature comparison stage of a control, electric energy can be supplied to the expansion element of the thermostatic valve so that, depending on the demand, the temperature level of the coolant and thus of the internal-combustion engine switches from a high temperature level to a lower temperature level; that is, increases the cooling output depending on the demand.

Abstract: An arrangement is disclosed for the apportioning if the idling air of internal-combustion engines having an adjustment motor for driving an adjusting member for changing a flow control cross-section and a supplementary device which can be actuated when the internal-combustion engine is rendered inoperative and is used for controlling the adjusting member into a minimum opening of the flow cross-section serving as an emergency cross-section. The supplementary device comprises two magnets arranged to mutually affect one another, one of the magnets being rendered essentially inoperative during the operation of the internal-combustion engine and thus during the operation of the arrangement.

Abstract: A rocker arm for a valve of a combustion engine comprising a lever arm with an offset end portion arranged in parallel to the longitudinal axis of the rocker arm. On a side face of said lever arm offset portion there is fixed an element for adjusting the valve clearance, oriented along the longitudinal axis of the rocker arm.