Variable Inlet Valve Timing Control via Bevel Surface
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Solution Overview
Problem
Turbocharged internal combustion engines often face insufficient inlet air during low engine loads and start-up, due to shorter cam nose forms and higher pressures, which require improved control arrangements for inlet valve closure to ensure proper air supply for compression ignition.
Innovation Solution
A variable timing control arrangement for the closing phase of the inlet valve, utilizing a bevel control surface and adjustable components such as turnable piston members and sleeve members, allows for precise adjustment of the delay in valve closure to optimize air supply, incorporating a regulation shaft and control unit for optimal engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If higher pressures and shorter cam nose forms are used in turbocharged engines, then charging action occurs in shorter time, but the opening times of inlet valves become not long enough for sufficient air supply during low loads and start-up
Solution Approach 1:
The patent applies a variable inlet valve closure (VIC) system that dynamically adjusts the inlet valve closure timing based on engine operating conditions. The control means includes a bevel control surface that can change and variably adjust the timing of pressure release in the first chamber, allowing the valve closure timing to be extended when needed for sufficient air supply, while maintaining the short charging action time during high load conditions.
2Quantity of substance
If the inlet valve closure timing is extended to provide sufficient air supply, then air quantity for compression ignition is improved, but the valve closing phase duration increases
Solution Approach 1:
The system dynamically adjusts the valve closure timing by controlling pressure release in the first chamber through the bevel control surface. The control means can extend the valve closure timing when sufficient air supply is needed, while the ability to release pressure provides a mechanism to control the overall duration of the closing phase, allowing optimization between air quantity and time.
3Quantity of substance
If a delay function is added to the inlet valve closure control, then air supply during low loads and start-up is improved, but the control arrangement complexity increases
Solution Approach 1:
The patent uses a pneumatic control system where a first chamber and second chamber are connected via an outlet flow duct. Pressure can be supplied to the first chamber to create a delay function for inlet valve closure. The control means includes a bevel control surface that controls pressure release, using pneumatic principles to achieve variable timing adjustment without complex mechanical or electronic systems.
Solution Approach 2:
The system changes the timing parameter of valve closure by controlling pressure release in the first chamber. The bevel control surface allows variable adjustment of the pressure release timing, which directly controls the valve closure timing. This parameter-based control approach provides the delay function while keeping the control arrangement relatively simple compared to electronic control systems.
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 provides wider possibilities for delaying inlet valve closure, ensuring adequate air supply during low engine loads and start-up, enhancing engine performance by allowing full regulation from maximum to minimum delay, thus addressing the challenges of insufficient air supply in turbocharged engines.
Implementation Method 1
the control means for controlling the releasing of pressure in the first chamber include a bevel control surface arranged for changing and variably adjusting the timing of the releasing of pressure in the first chamber
Implementation Method 2
the guide member presses the piston member against the force of a spring when the control arrangement moves in the direction for lifting the inlet valve
Implementation Method 3
the opening of the outlet flow duct into the second chamber is selectively controlled by the guide member
Data Source
Figure 1
Figure 2
Figure 3~3a
AI summary
The invention relates to a control arrangement for an inlet valve in a piston engine adapted between a cam device (5) of a camshaft (4) of the engine (1) and an inlet valve mechanism (6) arranged to open and close the inlet valve (3) in association with a cylinder of the engine. The control arrangement (7) comprises a body part (8), in which a piston device (9) is movably arranged to be in force transmission connection with the cam device (5) and the valve mechanism (6), and a guide member (10) arranged in the body part (8) between the cam device (5) and the piston device (9) to be movably responsive with the movements of the cam device (5). The body part (8) and the piston device (9) define together a first chamber (13), into which hydraulic medium can be selectively fed. The flow of hydraulic medium out from the first chamber (13) is controlled for providing a delay in the closing of the inlet valve (3). The control means for controlling the releasing of pressure in the first chamber (13) include a bevel control surface (19a;25a;25'a;29a) arranged for changing the timing of the releasing of pressure in the first chamber (13).