Integrated Electro-Hydraulic Steering Control Valve Group
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electro-hydraulic steering control systems for excavation machines are cumbersome due to separate valve group housings for primary and redundant control circuits, leading to increased weight, space requirements, and potential leak points, with stagnant fluid circulation during non-operation causing decreased responsiveness, especially during cold startups and redundant system cutover.
Innovation Solution
A single valve group housing integrates the steering circuit, primary control circuit, and redundant control circuit, with internal passages for fluid communication, and thermal bleed paths to maintain fluid circulation and responsiveness, reducing weight and space while minimizing leak points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate valve group housings are used for primary and redundant control circuits, then reliability is improved through redundancy, but weight and space requirements increase
Solution Approach 1:
The patent combines the primary control circuit and redundant control circuit into a single integrated valve group housing, eliminating the need for separate housings. This merging maintains the redundancy function while significantly reducing overall weight and space requirements, directly resolving the contradiction between reliability through redundancy and weight reduction.
Solution Approach 2:
The single valve group housing is designed to serve multiple functions: housing both primary and redundant control circuits, providing internal fluid communication passages, and eliminating the need for external hoses. This multi-functionality allows the system to maintain redundant control capability while reducing the total number of components and overall weight.
2Reliability
If separate valve group housings are used for primary and redundant control circuits, then redundancy is achieved, but the number of leak points increases
Solution Approach 1:
By merging both control circuits into a single housing with internal fluid passages, the patent eliminates the external hoses and connection points that would otherwise create multiple potential leak paths. The internal integration ensures fluid communication while minimizing exposure points where leaks could occur.
3Stability of the object's composition
If pilot valves are biased to closed positions during non-operation, then system stability is maintained, but fluid circulation stops causing decreased responsiveness during cold startup
Solution Approach 1:
The patent incorporates thermal bleed paths that enable preliminary fluid circulation and warming of the hydraulic fluid before the system is fully activated. This preliminary action prevents cold, viscous fluid from causing delayed responsiveness when the system first starts up, while the closed bias position maintains system stability during non-operation.
Solution Approach 2:
The thermal bleed paths provide continuous fluid circulation and heating even when the pilot valves are in their closed bias position. This continuous useful action ensures the fluid remains at optimal temperature and viscosity, maintaining system responsiveness without compromising the stability provided by the closed bias position.
4Weight of stationary object
If a single valve group housing is used, then weight and space are reduced, but integration complexity increases
Solution Approach 1:
The patent integrates multiple control circuits into a single housing with internal fluid passages, eliminating the need for external hoses and multiple connection points. While this merging increases internal integration complexity, it significantly reduces overall weight and eliminates external leak paths, making the increased internal complexity worthwhile for achieving the weight and reliability goals.
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 integrated system enhances responsiveness during cold starts and redundant control crossovers, reduces maintenance needs, and optimizes packaging, leading to improved performance and efficiency by minimizing fluid resistance and potential leak points.
Implementation Method 1
a thermal bleed path from the pilot fluid supply line to the pilot fluid drain line downstream of the primary pilot valve for allowing flow of warm pilot fluid to the drain line when the primary pilot valve is in its closed position
Implementation Method 2
A thermal bleed orifice in the redundant control circuit for allowing flow of warm steering fluid to the drain line
Data Source
AI summary
A steering control system includes a steering circuit, a primary control circuit and a redundant control circuit. The primary control circuit includes primary proportional control valves, and a primary pilot valve having a thermal bleed of pilot fluid to warm the primary pilot valve when not operating to control the steering circuit. The redundant control circuit includes secondary proportional control valves, and a pressure reducing valve having a thermal bleed orifice allowing fluid flow to warm the pressure reducing valve when not operating to control the steering circuit. The thermal bleeds may also flow past the proportional control valves to raise their temperatures. The circuits of the steering control system are contained in a single valve group housing.