Internal Combustion Engine Piston Cooling Oil Jet Control
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Solution Overview
Problem
High water content in engine oil can lead to emulsification, causing the oil to occlude the cavity in the piston, thereby preventing effective cooling by the first oil jet in internal combustion engines.
Innovation Solution
A control device for an internal combustion engine that includes a first oil jet to spray oil into a cavity through a hole on the piston's back surface, a second oil jet to spray oil on a different portion of the piston's back surface, and a processing circuit to manage the oil jet operations based on piston temperature, ensuring that the first oil jet is restricted and the second oil jet is used to warm the oil when the piston temperature is below a predetermined threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the first oil jet sprays oil into the cavity to cool the piston, then the cooling effect is improved, but when water content in the oil is high, the oil forms emulsion that occludes the cavity, preventing effective cooling
Solution Approach 1:
The patent applies dynamics by making the oil jet system adjustable and adaptive. The control device dynamically switches between different oil jet modes (first oil jet for cooling, second oil jet for warming) based on real-time piston temperature feedback. This dynamic control ensures oil is sprayed in the appropriate state - preventing emulsion formation at low temperatures while enabling effective cooling at high temperatures, thus resolving the contradiction between cooling effectiveness and system reliability.
Solution Approach 2:
The patent changes the temperature parameter of the oil by using two different spray configurations. The first oil jet sprays oil into the cavity for cooling when the piston is hot, while the second oil jet sprays oil to the outer surface for warming when the piston is cold. This parameter change in oil temperature and spray location prevents emulsion formation and ensures reliable operation across different temperature conditions.
2Temperature
If oil is sprayed continuously to ensure cooling, then cooling coverage is improved, but unnecessary oil injection occurs when the piston temperature is low, potentially causing emulsion formation
Solution Approach 1:
The patent implements feedback control by using a temperature sensor to continuously monitor piston temperature and adjusting the oil jet operation accordingly. When the piston temperature is below a predetermined threshold, the control device restricts or stops oil injection from the first oil jet, preventing emulsion formation. When the temperature exceeds the threshold, oil injection is activated for cooling. This feedback mechanism eliminates unnecessary oil injection while maintaining effective temperature control.
Solution Approach 2:
The oil injection system transitions from a static continuous spray to a dynamic conditional spray based on temperature feedback. The control device dynamically adjusts the spray state (on/off) and spray location (first or second oil jet) according to real-time piston temperature, preventing harmful emulsion formation during cold operation while ensuring adequate cooling during hot operation.
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 solution effectively suppresses cavity occlusion by the emulsified oil and warms the oil when the piston temperature is low, ensuring efficient cooling and preventing unnecessary oil injection.
Implementation Method 1
a first oil jet configured to spray, to cause oil to flow into a cavity extending through a piston, the oil toward a hole that is continuous with the cavity and is open to a back surface of the piston
Implementation Method 2
execute a second process for restricting the spraying of the oil from the first oil jet and spraying the oil from the second oil jet when the acquired temperature of the piston is lower than the predetermined temperature
Data Source
AI summary
The internal combustion engine includes a first oil jet that injects oil toward an inflow hole for flowing oil into the cavity, and a second oil jet that injects oil to a back surface so that the oil does not flow into the cavity. The control device of the internal combustion engine determines whether the temperature of the piston is equal to or higher than a specified temperature which is a threshold value for determining whether the piston has overheated to the extent that cooling is required. When the temperature of the piston is equal to or higher than the specified temperature, the control device cools the piston by using the first oil jet. When the temperature of the piston is lower than the specified temperature, the control device restricts the injection of the oil from the first oil jet and warms up the oil using the second oil jet.