Valve Timing Adjuster Drain Flow Restrictor Design
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Solution Overview
Problem
Existing valve timing adjustment devices suffer from reduced responsiveness due to excessive hydraulic oil discharge through large cross-sectional area drain flow restrictors, which reduces the amount of oil re-supplied to retard and advance chambers.
Innovation Solution
A valve timing adjustment device with a hydraulic oil controller that includes a drain flow restrictor with a smaller cross-sectional area than the recycle oil passage, ensuring more hydraulic oil is re-supplied to the chambers while minimizing discharge through the drain flow restrictor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a drain flow restrictor with large cross-sectional area is used, then hydraulic oil can be discharged more easily from the chambers, but the responsiveness of the valve timing adjustment device is reduced due to excessive discharge
Solution Approach 1:
The patent applies parameter changes by precisely controlling the cross-sectional area of the drain flow restrictor to be smaller than the smallest passage cross-sectional area of the recycle oil passage. This parameter optimization ensures that hydraulic oil discharge is restricted to an appropriate level, preventing excessive discharge that would reduce responsiveness while still allowing necessary oil removal from the chambers.
2Ease of operation
If a drain flow restrictor with large cross-sectional area is used, then hydraulic oil discharge is facilitated, but the amount of oil re-supplied to the chambers is reduced
Solution Approach 1:
The patent optimizes the drain flow restrictor's cross-sectional area parameter to maintain an appropriate balance between discharge and re-supply. By setting the restrictor area smaller than the recycle passage area, the system ensures sufficient hydraulic oil is re-supplied to the chambers through the recycle oil passage while still allowing controlled discharge when needed.
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 enhances the responsiveness of the valve timing adjustment device by increasing the re-supplied hydraulic oil amount and reducing unnecessary discharge, thereby improving the device's operational efficiency.
Implementation Method 1
The drain flow restrictor is formed in the drain oil passage at a location between the partition and the drain port. A passage cross-sectional area of the drain flow restrictor is smaller than a smallest passage cross-sectional area of the recycle oil passage and is constant.
Implementation Method 2
The recycle oil passage connects between: a portion of the drain oil passage located between the partition and the drain port; and the retard supply oil passage or the advance supply oil passage.
Implementation Method 3
The valve timing adjustment device rotates the vane rotor in a retarding direction or an advancing direction by supplying hydraulic oil to retard chambers or advance chambers defined by the vane rotor in the inside of the housing.
Data Source
AI summary
A drain port of a hydraulic oil controller is connected to an oil discharge portion. Each of partitions partitions between a corresponding one of drain oil passages and a corresponding one of a retard supply oil passage and an advance supply oil passage. Each of the drain oil passages connects between the oil discharge portion and a corresponding one of a retard chamber and an advance chamber. A recycle oil passage connects between: a portion of each drain oil passage located between the corresponding partition and the drain port; and the retard supply oil passage or the advance supply oil passage. A drain flow restrictor is formed in the portion of each drain oil passage located between the corresponding partition and the drain port. A passage cross-sectional area of the drain flow restrictor is smaller than a smallest passage cross-sectional area of the recycle oil passage and is constant.