Variable Valve Controller Viscosity Adaptation
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Solution Overview
Problem
Existing variable valve device controllers for internal combustion engines indiscriminately limit the operation of the phase changing mechanism based on hydraulic oil temperature, restricting valve timing changes and reducing the engine's operational flexibility.
Innovation Solution
A controller that adjusts the limiting control of the phase changing mechanism based on the viscosity of the hydraulic oil, allowing for a greater range of valve timing changes according to engine operation states by defining specific operational states and ranges, and varying the limiting control period and range based on oil viscosity and composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the operation of the phase changing mechanism is limited indiscriminately when hydraulic oil temperature is low, then the stability of feedback control is improved, but the valve timing adjustment range is excessively limited
Solution Approach 1:
The patent applies dynamics by making the limiting control adaptive rather than static. The controller dynamically adjusts the valve timing adjustment range based on real-time detection of hydraulic oil viscosity characteristics, allowing the system to transition between restricted and unrestricted modes of operation according to actual oil conditions, thereby resolving the contradiction between control stability and adjustment flexibility
Solution Approach 2:
The patent changes the control parameter from solely temperature-based to viscosity-based limiting control. By detecting the viscosity characteristic of the hydraulic oil and using this as the basis for determining whether to apply limiting control, the system adjusts the valve timing range appropriately according to the actual oil properties, preventing excessive limitation while maintaining stability when needed
2Reliability
If limiting control is applied based on hydraulic oil temperature, then control stability is ensured, but the operational flexibility is reduced
Solution Approach 1:
The patent implements feedback by continuously detecting the viscosity characteristic of the hydraulic oil and using this information to adjust the limiting control strategy. The controller receives feedback about the actual oil conditions and modifies the valve timing adjustment range accordingly, ensuring that operational flexibility is maintained when the oil viscosity indicates it is safe to do so, while still providing stability when necessary
3Reliability
If the variable range of valve timing is limited excessively, then control stability is maintained, but the engine performance is compromised
Solution Approach 1:
The patent changes the parameter basis for limiting control from temperature alone to viscosity characteristics. By detecting the actual viscosity of the hydraulic oil and adjusting the variable range accordingly, the system allows greater valve timing adjustment when the oil viscosity indicates low resistance, thereby improving engine performance while maintaining stability when the oil conditions require restricted 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 approach enhances the engine's ability to change valve timing in accordance with engine operation states, reducing the frequency of engine stalls and improving engine performance by tailoring the variable range and limiting period to the specific characteristics of the hydraulic oil.
Implementation Method 1
the operating speed of the phase changing mechanism varies under the influence of not only the temperature of hydraulic oil but also the viscosity of hydraulic oil
Data Source
AI summary
A controller for a variable valve device of an internal combustion engine includes a hydraulic valve timing changing mechanism that changes the valve timing VT of an intake valve, a valve timing locking mechanism that locks the valve timing VT to an intermediate phase, and an electronic controller that controls the operation of the valve timing changing mechanism. The electronic controller limits the variable range of the valve timing VT in accordance with the composition of hydraulic oil, when the operational state of the valve timing changing mechanism is a phase-unlocked state in which the valve timing VT can be changed.