Chain Tensioner Plug Venting for Adjustable Hydraulic Damping
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Solution Overview
Problem
Existing chain tensioners face challenges in adjusting hydraulic damper force due to temperature variations and engine-specific requirements, necessitating separate designs for different engine types, which increases costs and complexity.
Innovation Solution
A chain tensioner system where the hydraulic damper force can be easily adjusted by changing the plug with a different leak groove, allowing common parts to generate varying damper forces across different engine types without altering the internal structure of the cylinder and plunger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the leak gap setting is changed to adjust hydraulic damper force, then the damper force can be modified, but the characteristics change with temperature variations causing large differences between normal and high temperature performance
Solution Approach 1:
The invention divides the adjustment mechanism into separate modular components: the cylinder body remains fixed while interchangeable plugs with different leak groove configurations can be installed. This segmentation allows the leak gap characteristics to be changed by simply replacing the plug component, enabling adaptation to different temperature conditions and engine types without redesigning the entire tensioner assembly.
2Reliability
If separate chain tensioner designs are created for different engine types, then each engine type gets optimized performance, but manufacturing costs and design complexity increase
Solution Approach 1:
The invention creates a universal cylinder body design that can accommodate multiple plugs with different leak groove patterns. This single base design serves multiple engine types and applications, with the ability to switch between different performance characteristics by changing only the plug component. This eliminates the need for completely separate tensioner designs for different engines, reducing overall system complexity while maintaining engine-specific optimization.
3Reliability
If separate chain tensioner designs are created for different engine types, then each engine type gets optimized performance, but manufacturing costs increase
Solution Approach 1:
By segmenting the tensioner into a standardized cylinder body and interchangeable plugs, the manufacturing process can produce large quantities of common cylinder bodies and plugs separately through efficient mass production techniques. This modular approach allows each component to be manufactured optimally and then assembled, significantly reducing total manufacturing costs compared to producing complete custom tensioners for each engine type.
Solution Approach 2:
The invention enables the recovery and reuse of the expensive cylinder body component across multiple applications. Instead of discarding or redesigning the entire tensioner for each engine type, the durable cylinder body can be retained and paired with different plugs as needed, reducing material waste and manufacturing costs while maintaining performance optimization for different engines.
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 production of chain tensioners with diverse hydraulic damper forces using common components, reducing manufacturing costs and simplifying adaptation to different engine behaviors.
Implementation Method 1
a return spring biasing the plunger in the direction in which the plunger protrudes out of the cylinder
Implementation Method 2
hydraulic oil in the pressure chamber flows through a leak gap between the sliding surfaces of the plunger and the cylinder, thus damping and slowing down the movemerit of the plunger due to the viscous resistance of hydraulic oil
Implementation Method 3
a check valve provided at the end of the oil supply passage connected to the pressure chamber, and configured to allow only a flow of hydraulic oil from the oil supply passage toward the pressure chamber
Data Source
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AI summary
A chain tensioner (1) includes an oil supply passage (13) for supplying hydraulic oil into a pressure chamber (12) defined by a cylinder (9) and a plunger (10), and a check valve (14) provided at the end of the oil supply passage (13). A leak gap (15) is defined between the sliding surfaces of the cylinder (9) and the plunger (10). The plunger (10) is biased by a return spring (16) in the direction in which the plunger (10) protrudes out of the cylinder (9). A plug (18) is press-fitted in a cylindrical inner periphery of a through hole (17) formed in the plunger (10) to extend from a protruding end surface (11) of the plunger (10) to the pressure chamber (12) to define an air vent passage (20). It is possible to change the hydraulic damper force simply by replacing the plug (18) with another different kind of plug (18', 18") to define a different air vent passage (20', 20").