Variable Valve Device External Oil Pump Maintenance
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Solution Overview
Problem
The maintenance of oil control valves and pumps for cylinder suspension mode in internal combustion engines is hindered by their location within the cylinder head, requiring the removal of the rocker cover, which complicates maintenance and increases the frequency of maintenance tasks.
Innovation Solution
A variable valve device with a camshaft-driven mode switching oil pump and oil control valve positioned on the outer wall of the engine body, allowing maintenance without detaching engine parts, ensuring secure oil pressure for mode switching even at low engine speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the oil control valve and pump are positioned inside the cylinder head, then the switching function is achieved, but maintenance becomes difficult requiring rocker cover removal
Solution Approach 1:
The oil control valve and pump are extracted from the internal cylinder head location and positioned on the external side of the cylinder head. This allows the switching function to be maintained while enabling direct maintenance access without removing the rocker cover, resolving the contradiction between functional integration and maintenance accessibility.
2Device complexity
If the lubricating oil pump is used for cylinder suspension mode switching, then the system is simplified, but oil pressure is insufficient at low engine speeds
Solution Approach 1:
A dedicated mode switching oil pump is introduced as an intermediary component specifically for cylinder suspension mode switching. This separate pump ensures reliable oil pressure delivery at all engine speeds without complicating the main lubrication system, resolving the contradiction between system simplicity and pressure reliability.
3Reliability
If a dedicated oil pump for cylinder suspension mode is added, then oil pressure is secured at low speeds, but maintenance frequency increases
Solution Approach 1:
The mode switching oil control valve and pump are merged into a single integrated assembly positioned externally on the cylinder head. This combination allows both components to be maintained together as one unit, reducing the overall maintenance burden despite the addition of the dedicated pump, thereby resolving the contradiction between pressure reliability and maintenance frequency.
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
Facilitates maintenance of the oil control valve and pump without disassembling the engine, ensuring reliable operation and increased maintenance frequency for the cylinder suspension mode, reducing maintenance complexity and time.
Implementation Method 1
a camshaft-driven mode switching oil pump which supplies an oil pressure for switching driving to the variable valve mechanism
Implementation Method 2
a camshaft-driven mode switching oil pump which supplies an oil pressure for switching driving
Implementation Method 3
the variable valve mechanism is driven by an oil pressure of the engine oil, and lifts (open and close) of an inlet valve and an exhaust valve
Data Source
AI summary
A variable valve device for an internal combustion engine includes an internal combustion engine body having a plurality of cylinders, a variable valve mechanism which is provided in the body and is switchable between at least two modes with oil pressure, a mode switching oil control valve which switches the variable valve mechanism to each mode, and a camshaft-driven mode switching oil pump which supplies an oil pressure for switching driving to the variable valve mechanism according to the switching of the mode switching oil control valve. The mode switching oil control valve is, along with the mode switching oil pump, provided in an outer wall surface of the body.