Engine Cooling Circuit with Thermostatic Valve Control
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Solution Overview
Problem
Existing motor vehicle engine cooling circuits are complex and costly due to the need for multiple conduits for degassing and additional bypasses, particularly for automatic gearboxes which can overheat quickly, and they do not efficiently manage cooling and heating modes, especially during engine shutdown.
Innovation Solution
A cooling circuit design that separates the coolant outlet box from the radiator with a shut-off valve opening above a temperature threshold, allowing intermittent degassing without increasing complexity, and includes a temperature sensor to control valve openings, eliminating direct connections to the degassing box and bypasses, and enabling continued heating of the passenger compartment when the engine is stopped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple conduits are added to the cooling circuit for degassing and gearbox cooling, then the reliability and cooling capability are improved, but the device complexity and cost increase
Solution Approach 1:
The cooling circuit is designed with multi-functionality where the same cooling passages in the engine block serve multiple purposes: engine cooling, gearbox cooling, and degassing. The thermostat valve controls a single circulation path that can redirect coolant to different destinations (radiator or gearbox) based on thermal needs, eliminating the need for separate dedicated cooling circuits for each component.
Solution Approach 2:
The patent combines multiple cooling functions into a unified cooling circuit architecture. The degassing function is integrated into the existing cooling passages rather than requiring separate conduits. The thermostat valve merges the control of engine and gearbox cooling into a single control mechanism, reducing the overall number of components and simplifying the circuit while maintaining all necessary cooling and degassing functions.
2Temperature
If a bypass duct is added for gearbox cooling, then the cooling capability is improved, but the device complexity and cost increase
Solution Approach 1:
The thermostat valve is designed with multi-functionality to control coolant flow to multiple destinations. It can redirect coolant to the radiator for engine cooling or to the gearbox for transmission cooling based on temperature sensors and control signals, allowing a single valve to manage multiple thermal management functions without requiring separate control valves for each component.
Solution Approach 2:
The cooling circuit incorporates dynamic control through the thermostat valve which can adjust its position based on real-time temperature feedback from sensors. The valve transitions between different states (open to radiator, open to gearbox, or closed) to dynamically optimize cooling distribution, allowing the system to adapt to varying thermal conditions without fixed dedicated bypasses.
3Temperature
If the air heater is powered during engine shutdown, then the heating capability is improved, but the energy consumption increases
Solution Approach 1:
The cooling circuit maintains continuous coolant circulation even during engine shutdown through the thermostat valve being held in an open position by a control signal. This allows the air heater to continue receiving hot coolant from the engine block, maintaining passenger compartment heating capability without requiring the engine to be running, while the system monitors energy consumption to manage the extended operation.
Solution Approach 2:
The system incorporates temperature sensors and control logic that monitor both engine temperature and air heater operation status. The control unit receives feedback about the thermal state and adjusts the thermostat valve position accordingly, allowing intelligent management of the heating function during engine shutdown to balance comfort requirements with energy conservation goals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design simplifies the cooling circuit, reduces costs, and effectively manages the cooling and heating of both the engine and automatic gearbox without delaying engine heating, while allowing for efficient heating of the passenger compartment during engine shutdown.
Implementation Method 1
A temperature sensor (4) and a thermostat (5) are located in the outlet box (3)
Implementation Method 2
a thermostatic valve (5) which releases the flow of liquid between the outlet box (3) and a radiator (7) above a threshold temperature
Implementation Method 3
The function of the radiator (7) is to cool the cooling liquid, in this case water, flowing in the cooling circuit (1)
Implementation Method 4
a pump (8) delivering the coolant in pipes of the engine (2)
Implementation Method 5
A degassing box (18) receives the coolant through a line from the radiator (7) and removes bubbles from the coolant
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The circuit (1) has a cooling liquid outlet case (3) receiving a cooling liquid from an engine i.e. internal combustion engine (2). A cooling radiator (7) receives the liquid from the case. A thermostatic valve (5) closes the flow of the liquid between the case and the radiator. The valve is opened, when the temperature of the liquid in the case exceeds a threshold. A valve opening control controls intermittent opening of the valve, even when the temperature of the liquid in the case is lower than the threshold. An independent claim is also included for a method for controlling a cooling circuit.