Daimler Chrysler Ag

Mercedes-benz Aktiengesellschaft

Daimler-benz Ag

Herbert Wieszt

Wolfgang Straub

Werner Salzer

The invention relates to a method for monitoring the refrigerant filling level of a refrigerating system, in particular a motor vehicle air-conditioning system, with a compressor subdividing the refrigerant circuit into a high-pressure side and a low-pressure side. The evaporator temperature is determined at the evaporator at short time intervals by means of an evaporator temperature sensor. According to the invention, there is provision for a time meter, t, to be activated when the evaporator temperature exceeds a predetermined threshold temperature.

Method for monitoring the refrigerant filling level in refrigerating system

The invention relates to a method for monitoring the refrigerant level in an air conditioner, in particular a motor vehicle air conditioner, with a compressor which subdivides the refrigerant circuit into a high-pressure side and a low-pressure side. The method includes the steps of measuring the pressure and the temperature on the high-pressure side at time intervals, determining an assigned temperature using the measured pressure with the aid of a refrigerant-specific function, and determining a refrigerant undercooling value which can be evaluated as a measure of the refrigerant level by subtracting the measured temperature from the assigned one.

Method for monitoring the refrigerant level in an air conditioner

A circuit arrangement for actuating an air-conditioning system or an automatic air conditioner in a vehicle, in which it is possible to switch the air-conditioning system or automatic air conditioner on and off when the engine is operating. Here, the air-conditioning system or automatic air conditioner is switched off, if the air-conditioning system or automatic air conditioner is operating while the engine is operating and the engine is switched off. Further, the air-conditioning system or automatic air conditioner continues to possess a function with which, when the engine of the vehicle is stationary, the residual heat of the engine is utilizable. Additionally, at least one function of the air-conditioning system or automatic air conditioner, which is switchable manually when the engine is operating, is switchable via the same control element used to activate and deactivate the function in which the residual heat is utilized when the engine is stationary.

Circuit arrangement for actuating an air-conditioning system or automatic air conditioner in a vehicle

A process provides vehicle-air-conditioning-influencing outside temperature information for an outside-temperature-dependent air conditioning of a motor vehicle interior, in the case of which the outside temperature is sensed continuously and the air-conditioning-influencing outside temperature information is obtained from the pertaining sensor signal. During hold phases which are triggered when a defined starting condition occurs, the air-conditioning-influencing outside temperature information is held at its temperature value when the sensed outside temperature value rises or stays the same. The hold phase starting condition consists of the fact that the vehicle speed is lower than a definable speed threshold value and the temperature of the motor vehicle driving engine or of a coolant for the driving engine is higher than a definable engine temperature threshold value or coolant temperature threshold value.

Process for providing outside temperature information for influencing

A method for controlling the evaporator temperature of an air conditioner as a function of the outside dew point, in which the dew point temperature of the intake air drawn in by the air conditioner to air-condition an interior and the blown air temperature setpoint that is associated with one or more variably presettable interior temperature setpoints is determined for the intake air to be blown out into the interior. At the beginning of each cooling cycle, a determination is made as to whether the evaporator is wet or dry. The evaporator temperature is then adjusted to a setpoint that is at most approximately as high as the dew point temperature and otherwise is approximately as high as the blown air temperature setpoint. This is for cases within presettable limits, with a wet evaporator and a blown air temperature setpoint that is above the intake air dew point temperature. Alternatively, interrogation of the evaporator state can be eliminated and the smaller of the blown air temperature setpoint and the outside temperature dew point temperature differential is selected as the evaporator temperature. A typical use of the method, for example, is in the air conditioners of motor vehicles.

Method for controlling the evaporator temperature of an air conditioner

A method for controlling the evaporator temperature of an air conditioner as a function of the outside dew point, in which the air temperature and the dew point temperature of the incoming air drawn in from outside by the air conditioner for air conditioning an interior are determined. An evaporator demand temperature without reheating is determined from the interior temperature setpoint information. On the one hand, the evaporator temperature is set to a setpoint that, within presettable temperature limits, is selected as the smaller value of the evaporator demand temperature. On the other hand, the evaporator temperature is set to a setpoint that, within presettable temperature limits, is the difference between the air temperature and the dew point temperature of the incoming air on the other. A typical use of the method, for example, is in the air conditioners of motor vehicles.

Method for evaporator temperature control as a function of the outside

A method and apparatus for ventilation of a vehicle interior which can be switched between an incoming air operating mode and a circulating air operating mode as a function of harmful substances. The incoming-air concentrations of several harmful gases are measured and are separately evaluated. In each case either an incoming air operation request or a circulating air operation request is generated. A circulating air operation adjustment command is generated if the analysis for at least one of the harmful gases results in a circulating air operation request. The incoming air operation the vehicle-interior concentration of each harmful gas is estimated continuously as a function of the pertaining measured incoming-air concentration and of an incoming air rate, and a circulating air operation adjusting command is generated if the estimated interior concentration of at least one harmful gas rises at a rate which exceeds a definable threshold value.

Arrangement and process for the ventilation of a vehicle interior as a

An air-conditioning unit is provided for a vehicle with an air-conditioning function depending on the outside dew point. The air-conditioning unit includes a device for determining the dew point temperature of the outside air, an air duct leading to a window of the vehicle and having a controllable closing device, a device for determining the temperature of the air blown through the ducts leading to the window of the vehicle and a control device for automatically opening and closing the air duct leading to a window of the vehicle by appropriately energizing the air duct closing device. The control device, in the cooling operation of the air conditioning unit, opens and closes this air duct automatically as a function of the dew point temperature determined for the outside air and as a function of the temperature determined for the air blown out through this air duct. The air duct is kept closed by the control device as long as the temperature of the air blown out is lower than the dew point temperature of the outside air plus a specifiable safety offset temperature, and is otherwise kept open at least partially.

Vehicle air conditioning unit with an air-conditioning function

A sun sensing arrangement for a motor vehicle, and a method of arranging a sun sensor in a motor vehicle, in order to sense incident sunlight. The motor vehicle has an engine hood which includes a top-side air inlet grid area. The sun sensor is arranged inside the air inlet grid area of the engine hood. This positioning permits sunlight to be sensed in a large solid-angle range which is not influenced by the vehicle windows or objects mounted on the roof of the vehicle, and the styling of the vehicle body shell is not noticeably influenced.

Sun sensing arrangement and method of arranging a sun sensor in a motor

A process for a refrigeration system having a compressor which divides the refrigerant circuit into a high-pressure side and a low-pressure side measures on the high-pressure side the relative pressure and the temperature at time intervals. Whereupon, using the measured pressure, and on the basis of a refrigerant-specific function, an assigned temperature is determined. By subtracting the measured from the assigned temperature, a supercooling value is determined. The value can be analyzed as a measure of the refrigerant fill-level. At least during an operating phase which is greater than zero, which operating phase is defined by pre-defined operating conditions, for the evaluation of the refrigerant fill-level, a maximum value is used. The maximum value is set at the start of this operating phase to the last determined supercooling value and, in the course of this operating phase, respectively to a newly determined supercooling value in which at the respective instant, the supercooling value is greater than the previous maximum value. This enables the fill-level to be reliably monitored, including for refrigeration systems having a regulated compressor.

Process for monitoring the refrigerant fill-level in a refrigeration

A process for monitoring the coolant level in a cooling system, in particular in a motor vehicle in which the relative pressure and the temperature of the coolant are measured on the high-pressure side of the coolant circuit, using the measured pressure value. A temperature assigned to the pressure value is established on the basis of a coolant specific function (temperature=f (pressure)) and the undercooling of the coolant is then determined by subtracting the measured temperature from the assigned temperature, which undercooling is analyzed as a measure for the coolant level.

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Grafenau, Germany

Herbert Wieszt