Daimler Ag

Daimler Chrysler Ag

Jochen Weeber

Hans Braun

Ralf Körber

Michael Timmann

Erhard Rau

Hartmut Engels

Frank Weinert

Werner Engelin

The invention relates to a cooling system in which the fan output is determined by an output control from the characteristic curves of the fan motor, the operating parameters of the cooling system and the reference input variables predetermined in the form of temperature levels. Different characteristic curves for the activation of the fan motor are here assigned to the different set temperature levels. If the reference input variable for the control changes, this also results in a change of the characteristic curves for activation of the fan motor. In order to prevent the fan motor starting to howl, in the event of a change in the reference input variable for the fan control the operation of the fan motor is kept constant for an adjustable minimum waiting time. During this minimum waiting time, switching over of the cooling circuit may have caused the operating parameters of the cooling system to adjust to the new reference input variable to such a degree that howling of the fan motor is no longer of concern.

Cooling system for an internal combustion engine of a motor vehicle

In a coolant circuit for an internal combustion engine having two cylinder banks, a radiator for cooling the engine coolant, a pump and a thermostatic valve including a mixing chamber and first and second flow control valves, wherein the pump is connected to the radiator via an intake line for receiving coolant therefrom and supplying it to the cylinder banks which are in communication with the mixing chamber from which a radiator line extends to the radiator for returning heated coolant to the radiator under the control of a flow control valve, or supplying it via a bypass line to the intake line under the control of a bypass valve, a heating circuit is provided extending from one of the cylinder banks via a heater to the pump intake line and a heater control valve is disposed in the heating control circuit so that, upon opening of the heater valve, coolant flows from the other cylinder bank via the mixing chamber to the one cylinder bank and coolant from both cylinder banks jointly flows through the heating circuit back to the pump.

Coolant circuit for a coolant-cooled internal combustion engine

The invention relates to a method for actuating the valves in the three-way thermostat and in the heating cut-off valve of a cooling system. The valve setting in the cooling system is in this case selected such that during the warm-up phase of the engine, until the latter has reached its operating temperature, the coolant in the cooling ducts is brought to rest until the coolant temperature exceeds a predefined reference value.

Method for adjusting a coolant flow by means of a heating cut-off valve

The present invention relates to control of a fan during which the power of the fan is determined from the characteristic curves of the fan motor, the operating parameters of the cooling system and the reference variables which are predefined in the form of temperature levels. The various temperature levels which are to be set have different associated characteristic curves for actuating the fan motor. If the reference variable for the control changes, this also means a change in the characteristic curves for actuating the fan motor. In order to prevent the fan motor from whining, the operation of the fan motor is kept constant for a settable minimum waiting time when the reference variable for the control of the fan changes. During this minimum waiting time, the operating parameters of the cooling system can, if appropriate, be adapted by means of other control mechanisms which are independent of the fan to the new reference variable to such an extent that it is no longer necessary to take measures with respect to the whining of the fan motor.

Method for actuating a fan using a plurality of characteristic curves and a control program for controlling the power of the fan

A thermostatic valve for a coolant circuit of an internal combustion engine, with a housing through which the flow is capable of passing and which has a first throughflow orifice for connection to a first coolant line, a second throughflow orifice for connection to a second coolant line, and a third throughflow orifice for connection to a third coolant line, and with a closure member which is mounted in the housing and which can be adjusted by an actuating unit, the closure member having a first shut-off element for shutting off the first throughflow orifice and a second shut-off element, coupled to the first shut-off element, for shutting off the second throughflow orifice. The second shut-off element is assigned an adjusting device, via which the second shut-off element can be adjusted relative to the first shut-off element in such a way that the closure member can be brought, on one hand, into a passage position in which it can close exactly one throughflow orifice, and, on another hand, into a shut-off position, in which it can close two throughflow orifices.

Growing community of inventors

Filderstadt, Germany

Jochen Weeber