Method for controlling a cooling circuit for an internal-combustion engine using a coolant temperature difference value
First Claim
1. A method for controlling a cooling circuit of an internal combustion engine having at least one coolant pump for controlling the rate of flow of coolant in the coolant circuit, a radiator in which heat is exchanged between air passing through the radiator and coolant in the radiator, a fan for controlling the flow of air through the radiator, and a control unit for controlling the speed of the coolant pump comprising the steps of controlling the speed of the coolant pump and the fan when the coolant temperature is below a predetermined low limit temperature value as a function of a required temperature difference between the coolant temperatures at a coolant inlet to the engine and at a coolant outlet from the engine, which is determined using at least two engine operating parameters which affect engine temperature, one of the inlet and outlet temperatures being sensed and the other being determined according to the at least two engine operating parameters, and controlling the speed of the coolant pump and the speed of the fan when the coolant temperature is above the predetermined selected low limit temperature value as a function of both the required temperature difference and a required coolant operating temperature.
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Accused Products
Abstract
A method for controlling a cooling circuit of an internal combustion engine which includes a coolant pump for adjusting a coolant flow rate, a radiator in which heat is exchanged between the coolant and an air flow which can be controlled by a fan, and a control unit which controls at least the speed of the coolant pump and of the fan as a function of a required temperature value of the coolant. In order to shorten the warm-up phase of the engine and to minimize the power consumption of the pump and of the fan when the coolant temperature is below a selected low level, the speed of the coolant pump and the speed of the fan are controlled based on maintaining a required temperature difference of the coolant between the inlet and the outlet of the engine and, after the selected low level has been reached, the speed of the coolant pump and of the fan are controlled both as a function of the required temperature difference and of a required coolant temperature level at the engine outlet.
48 Citations
9 Claims
- 1. A method for controlling a cooling circuit of an internal combustion engine having at least one coolant pump for controlling the rate of flow of coolant in the coolant circuit, a radiator in which heat is exchanged between air passing through the radiator and coolant in the radiator, a fan for controlling the flow of air through the radiator, and a control unit for controlling the speed of the coolant pump comprising the steps of controlling the speed of the coolant pump and the fan when the coolant temperature is below a predetermined low limit temperature value as a function of a required temperature difference between the coolant temperatures at a coolant inlet to the engine and at a coolant outlet from the engine, which is determined using at least two engine operating parameters which affect engine temperature, one of the inlet and outlet temperatures being sensed and the other being determined according to the at least two engine operating parameters, and controlling the speed of the coolant pump and the speed of the fan when the coolant temperature is above the predetermined selected low limit temperature value as a function of both the required temperature difference and a required coolant operating temperature.
Specification