Hydraulic Valve Piston Ring Webs for Camshaft Adjuster Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic valves for camshaft adjusters face challenges in achieving optimal system behavior, particularly in the lower temperature range, and require a compact and efficient design that improves function and adjustment speed across varying temperature conditions.
Innovation Solution
A hydraulic valve design featuring a piston with outer ring webs that throttle tank outflow connections without control edges, allowing for precise fluid flow control and a bypass mechanism for enhanced adjustment speed, along with check valves for fluid diversion between chambers, ensuring efficient operation with viscous cold oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydraulic valve uses conventional control edges for throttling tank outflow connections, then the valve structure is simple, but the function in the lower temperature range deteriorates due to viscous cold oil
Solution Approach 1:
The piston is segmented into multiple ring webs (first, second, third, and fourth ring webs) that are axially spaced apart. Each ring web independently throttles a specific tank outflow connection (T1 or T2) in different end positions. This segmentation allows the valve to provide optimized flow control for each tank connection without requiring a single complex throttling mechanism, thereby improving cold temperature function while maintaining reasonable structural complexity.
2Speed
If the valve provides fast phaser function with bypass for quick fluid diversion, then the adjustment speed increases, but the system behavior and stability deteriorate
Solution Approach 1:
The valve provides dynamic flow control through the piston's ability to be positioned in different end positions (first, second, and intermediate positions). In intermediate positions, the valve enables a bypass function for fast adjustment speed. In end positions, the piston completely closes one tank outflow connection while throttling the other, providing stable hydraulic clamping. This dynamic positioning allows the system to switch between fast adjustment mode and stable clamping mode as needed.
Solution Approach 2:
The valve changes the throttling parameters of tank outflow connections based on piston position. In end positions, one tank connection is completely closed (throttling parameter = 0) while the other is throttled to a specific degree. In intermediate positions, both connections are partially open allowing bypass flow. This parameter change enables the valve to optimize system behavior for different operating conditions, achieving both fast adjustment and stable clamping.
3Reliability
If the piston completely closes both tank outflow connections in end positions, then the hydraulic clamping improves, but the oil exchange efficiency deteriorates
Solution Approach 1:
Instead of completely closing both tank outflow connections in end positions (which would maintain clamping but prevent oil exchange), the invention inverts the approach by completely closing one tank connection (T1 or T2) while leaving the other connection partially open for throttled flow. This allows the pressure chamber to be emptied through the throttled connection, maintaining hydraulic clamping while enabling continuous oil exchange and cooling, thus resolving the contradiction between clamping stability and oil exchange efficiency.
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
The design achieves improved function in the lower temperature range, reduced adjustment speed in the lower speed range, and increased adjustment speed in the upper speed range, while maintaining stable operation and efficient oil exchange.
Implementation Method 1
a piston (4) arranged in a bore (3) so as to be displaceable along a longitudinal direction (L) between a first end position and a second end position, with outer ring webs arranged on each of its axially outer ends in order to drain the tank outflow connection in the first or the second end position
Implementation Method 2
check valves arranged in the piston in the form of ball seat valves for utilizing alternating camshaft torques
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to a hydraulic valve (1), in particular for a rotary motor adjuster of a camshaft, comprising: - a bushing (2) with a piston (4) slidably arranged in a bore (3), - a supply port (P), - at least one first working port (A) and a second working port (B), and - at least one tank drain port (T1, T2), wherein a check valve (15, 16) is assigned to each of the first working port (A) and the second working port (B), and the first working port (A) and the second working port (B) can be alternately connected to each other and/or to the supply port (P) and/or to the tank drain port (T1, T2) by moving the piston (4) via at least one of the check valves (15, 16).According to the invention, the hydraulic valve (1) has five switching positions (10, 11, 12, 13, 14), wherein in the first and/or the fifth switching position (10, 14) the respective connection between the working port (A or B) and the tank drain port (T1, T2) is throttled without control edges.