Valve Timing Control via Intermediate Member Flow Passage
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Solution Overview
Problem
Existing valve opening and closing timing control apparatuses for internal combustion engines face challenges in efficiently controlling the relative rotational phase between drive-side and driven-side rotational members due to hydraulic oil leakage and instability in the position of components caused by thermal expansion differences, which affects the precise timing of valve operations.
Innovation Solution
The apparatus incorporates an intermediate member, such as an adapter, with strategically positioned outlet flow passages that direct hydraulic oil between the advanced and retarded angle chambers, reducing leakage and maintaining stable component positions through hydraulic pressure, while the electromagnetic control valve adjusts the relative rotational phase by controlling fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hydraulic oil is supplied to control the relative rotational phase between drive-side and driven-side rotational members, then valve timing control precision is improved, but hydraulic oil leakage occurs reducing reliability
Solution Approach 1:
A one-way valve is introduced as an intermediary component in the hydraulic oil supply path. This one-way valve allows hydraulic oil to flow from the supply passage to the advanced angle chamber and retarded angle chamber, but prevents backward flow and leakage. The one-way valve acts as a mediator that maintains the hydraulic pressure necessary for precise valve timing control while preventing oil leakage that would compromise reliability.
2Ease of manufacture
If components are positioned using conventional mounting methods, then assembly is simplified, but thermal expansion differences cause position instability
Solution Approach 1:
The mounting member incorporates a thermal expansion compensation mechanism that adjusts component positions in response to temperature changes. As materials expand or contract with thermal changes, the mounting member's design allows for controlled parameter changes in position while maintaining stable relative positioning of the drive-side rotational member, driven-side rotational member, and camshaft. This compensates for thermal expansion differences without complicating the assembly process.
3Volume of moving object
If the control valve mechanism is positioned within the driven-side rotational member, then space utilization is improved, but manufacturing complexity increases
Solution Approach 1:
The control valve mechanism is segmented into modular components that can be manufactured separately and then assembled into the driven-side rotational member. The one-way valve, supply passage, and control valve elements are designed as discrete parts that can be produced using standard manufacturing processes, then integrated into the final assembly. This segmentation reduces the manufacturing complexity of integrating all components into a single monolithic piece while still achieving compact space utilization within the driven-side rotational member.
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 configuration ensures precise control of valve timing, reduces hydraulic oil leakage, and stabilizes the position of components, leading to improved operational smoothness and reliability of the valve opening and closing process.
Implementation Method 1
a hydraulic pump is configured to supply hydraulic oil to the control valve mechanism
Implementation Method 2
an electromagnetic control valve actuator is configured to move the spool in the advance direction and in the retard direction
Data Source
AI summary
A valve opening and closing timing control apparatus includes a drive-side rotational member, a driven-side rotational member, an intermediate member abutting the driven-side rotational member, a mounting member connecting the driven-side rotational member and the intermediate member to the camshaft in a state being mounted at the camshaft, and a control valve mechanism arranged with a same axis as a rotation axis of the drive-side rotational member. The intermediate member includes an inner peripheral surface in contact with the outer peripheral surface of the mounting member. The flow passage includes an outlet flow passage provided at the intermediate member and positioned along a radial direction for sending out a fluid which is supplied to an inner peripheral surface of the intermediate member to an advanced angle chamber or a retarded angle chamber provided between the drive-side rotational member and the driven-side rotational member.