Cummins Engine Company, Inc.

Dipchand V Nishar

Thomas Dollmeyer

Christopher R Nelson

James A Cramer

A system for controlling air flow to an engine cooling system includes a control computer responsive to a number of engine and/or engine accessory operating conditions, and to various engine operational states to control operation of an engine cooling device. The engine operational states are each a function of at least engine fueling commands and include a 'free energy' state corresponding to zero fueling, an 'absorbing additional torque' state corresponding to zero fueling and activation of either service brakes or engine brakes, and a 'needs additional torque' state corresponding to a rapid positive change in fueling, recent gear shifting to the lower gears of the transmission with fueling above a predefined level or a high rate of change in fueling rate. All other engine operational states are defined as a don't care state. The control computer is operable to control the engine cooling device as a function of the number of engine and/or engine accessory operating conditions and a current engine operating state, wherein examples of the engine and/or engine accessory operating conditions include engine coolant temperature, rate of change of engine coolant temperature, intake manifold air temperature and air conditioner refrigerant pressure. The engine cooling device is preferably a single speed, dual speed or variable speed engine cooling fan.

System for controlling air flow to a cooling system of an internal

A system and method for air compressor control wherein the air compressor is loaded only when engine activities require it to be loaded or when free engine power is available to operate the compressor. An air compressor system is an engine-driven, piston-type compressor which operates in a loaded and an unloaded mode and provides air to a vehicle's air powered devices, such as service brakes, air suspension, windshield wipers, etc. The operating mode of the compressor is controlled by a pressure activated air governor which applies an air signal when pressure in a reservoir reaches a set level that activates a cap valve on an unloader stopping the air compressor. When the air pressure in the reservoir drops below a lower set pressure or when energy is 'free,' such as during downhill operations, the air governor exhausts the air signal allowing the air compressor to resume operation. Additionally, when the reservoir is of a pressure between the two set pressures and is in an unloaded state it will be maintained in that state for a set period of time to prevent rapid cycling of the air compressor. Further, when the reservoir is of a pressure between the two set pressures and is in a loaded state the air compressor will be unloaded after a set time interval that is based on a compressor head metal temperature to maintain threshold temperatures of the compressor head metal within a suitable range. Additionally, the compressor head is evaluated such that whenever the compressor head temperature exceeds a predetermined threshold temperature the air compressor is placed in an unloaded state until the compressor head temperature drops below the predetermined threshold temperature. The system is further capable of recording data indicative of compressor operation for detecting leaks in the air system and vehicle operator characteristics.

Air compressor control

An electronic air compressor control system and method including an actuator connected to an air compressor for regulating the loading and unloading of the air compressor based on predetermined conditions, a power supply electrically connected to the actuator for supplying a voltage thereto and a plurality of switches electrically coupled to the actuator and power supply for controlling the supply of voltage from the power supply to the actuator in order to control the operation of the air compressor based on a predetermined air compressor exhaust temperature threshold and minimum and maximum pressure thresholds. The unloading and loading of the air compressor is based on a predetermined air compressor exhaust temperature when the pressure within the wet tank is between the minimum pressure threshold and the maximum pressure threshold.

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Columbus, IN, United States of America

Dipchand V Nishar