Valve Timing Control Phase Displacement Restriction Mechanism
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Solution Overview
Problem
Existing valve timing control devices for internal combustion engines can only lock the relative rotational phase at a single predetermined lock phase, failing to accommodate variations in engine start conditions such as temperature, which affects optimal valve opening and closing timing.
Innovation Solution
A valve timing control device with a phase displacement restriction mechanism that allows the relative rotational phase to be locked at different phases by restricting displacement within a predetermined range, using a recess portion and insertion member biased to insert or retract, independent of the lock mechanism, and a retention mechanism to maintain the unrestricted state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the lock mechanism locks the relative rotational phase at a single predetermined lock phase, then the valve timing control device achieves reliable locking, but it cannot accommodate variations in engine start conditions such as temperature that affect optimal valve opening and closing timing
Solution Approach 1:
The locking function is segmented into two independent mechanisms: a lock mechanism for reliable locking at a predetermined phase, and a phase displacement restriction mechanism for limiting displacement within an allowable range. This segmentation allows each mechanism to specialize in one function, achieving both reliable locking and adaptability without excessive complexity
Solution Approach 2:
The phase displacement restriction mechanism introduces dynamic controllability by allowing the insertion member to move between inserted and retracted states based on operating conditions. This enables the system to switch between locked and restricted states, accommodating variations in engine start conditions while maintaining overall system reliability
2Reliability
If the insertion member is constantly biased to be inserted into the recess portion, then the phase displacement restriction mechanism achieves reliable restriction, but it cannot maintain the unrestricted state when needed for phase adjustment
Solution Approach 1:
A retention mechanism acts as an intermediary that counteracts the constant biasing force of the spring. When activated, the retention mechanism holds the insertion member in the retracted position despite the spring's inserting force, enabling the system to maintain the unrestricted state when needed while preserving the reliable restriction capability when the retention mechanism is not active
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
Enables the relative rotational phase to be locked at various phases, optimizing valve timing during engine start, reducing hydrocarbon emissions, and allowing for precise phase control, thereby improving engine performance and reducing emissions.
Implementation Method 1
the insertion member biased to be inserted into the recess portion
Implementation Method 2
displacing a relative rotational phase of the driven side rotational member to the driving side rotational member in a retarded angle direction by a supply of a fluid to the retarded angle chamber, an advanced angle chamber defined by the driving side rotational member and the driven side rotational member and displacing the relative rotational phase in an advanced angle direction by the supply of the fluid to the advanced angle chamber
Data Source
AI summary
A valve timing control device includes a driving side rotational member synchronously rotatable with a crankshaft of an internal combustion engine, a driven side rotational member synchronously rotatable with a camshaft that controls an opening and closing operation of valves of the internal combustion engine, a retarded angle chamber, an advanced angle chamber, a fluid supply and discharge mechanism, a lock mechanism for locking the relative rotational phase at a predetermined lock phase, a phase displacement restriction mechanism switching the relative rotational phase between a restricted state and an unrestricted state, the phase displacement restriction mechanism includes a recess portion and an insertion member so as to achieve the restricted state and the unrestricted state, and a retention mechanism for retaining the phase displacement restriction mechanism in the unrestricted state in which the insertion member is retracted from the recess portion.