Valve Timing Adjustment Device Axial Tension Alignment
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Solution Overview
Problem
The existing valve timing adjustment devices face issues with durability and productivity due to misalignment of countersunk and screw holes, leading to reduced axial tension and increased complexity in alignment processes.
Innovation Solution
A composite structure is designed with countersunk and screw holes having specific diameter differences and fitting parts that align correctly, allowing the plate screw component to engage without affecting alignment, thus ensuring proper fitting and securing the axial tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the countersunk hole and screw hole are accurately made in alignment before inserting the plate screw component, then the durability is improved, but the productivity falls since the alignment work becomes complicated
Solution Approach 1:
The plate screw component is designed with fitting parts that preliminarily align the countersunk hole and screw hole through interference fit, before the final tightening action. This preliminary alignment action eliminates the need for complicated pre-alignment work while ensuring proper positioning for durable connection.
Solution Approach 2:
The fitting parts of the plate screw component act as an intermediary mechanism between the countersunk hole and screw hole. These fitting parts facilitate automatic alignment through interference fit, serving as a mediator that resolves the alignment issue without requiring complex external alignment procedures.
2Productivity
If the axis of countersunk hole and screw hole are not in alignment, then the productivity is improved by omitting alignment work, but the axial tension becomes smaller and durability is lowered
Solution Approach 1:
The plate screw component performs self-alignment through its fitting parts that automatically position themselves correctly in the holes through interference fit. This self-service mechanism ensures proper alignment and maximum axial tension without requiring external alignment assistance, thereby maintaining both productivity and durability.
Solution Approach 2:
The fitting parts are designed with asymmetric interference fit characteristics that guide the plate screw component into proper alignment. The asymmetric geometry of the fitting parts and corresponding holes creates natural alignment forces that ensure the axes coincide, preventing misalignment while maintaining simple installation procedures.
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 enhances productivity by simplifying the alignment process and improves durability by maintaining the axial tension, ensuring high accuracy and reliability of the valve timing adjustment device.
Implementation Method 1
A difference δφa in diameter between the plate side fitting hole and the plate side fitting part, a difference δφb in diameter between the screw side fitting hole and the screw side fitting part
Implementation Method 2
a seat part having a tapered surface shape seated on the countersunk hole, a screw part shaped in a male thread and engaged with the screw hole
Data Source
AI summary
A composite structure includes: a cover plate having a countersunk hole and a plate side fitting hole; a bearing plate having a screw hole and a screw side fitting hole located opposite from the plate side fitting hole through the screw hole; and a plate screw component including a screw part engaged with the screw hole, and a plate side fitting part and a screw side fitting part respectively fitted with the plate side fitting hole and the screw side fitting hole to be in alignment with each other. A difference δϕa in diameter between the plate side fitting hole and the plate side fitting part, a difference δϕb in diameter between the screw side fitting hole and the screw side fitting part, and an effective difference δϕc in diameter between the screw hole and the screw part satisfy a dimensional relation of δϕa<δϕc and δϕb<δϕc.