Pilot Hydraulic Pressure Control Under High Engine Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic systems in work machines face challenges in maintaining optimal pilot pressure levels, particularly when the engine load exceeds a predetermined threshold, leading to reduced output and increased difficulty in operating hydraulic actuators efficiently.
Innovation Solution
The hydraulic system incorporates a pressure adjustment valve in the drain oil path to alter the pilot pressure, ensuring it remains below the target pressure when specific conditions are met, thereby optimizing the operation of hydraulic actuators by adjusting the pilot pressure gradient in response to engine load and operation amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the engine load increases beyond a predetermined threshold, then the engine power output increases, but the pilot pressure becomes insufficient leading to reduced hydraulic actuator performance
Solution Approach 1:
A pressure adjustment valve is introduced as an intermediary component in the drain oil path between the control valve and hydraulic oil reservoir. This valve mediates the relationship between engine load and pilot pressure by selectively restricting drain flow, thereby maintaining adequate pilot pressure even when engine load increases and the hydraulic pump's pressure generation capability is compromised.
Solution Approach 2:
The pressure adjustment valve dynamically changes the drainage parameter (flow resistance) in the drain oil path based on system conditions. By adjusting the degree of flow restriction, the valve modifies the pilot pressure level to compensate for engine load variations, ensuring the pilot pressure remains within the optimal range for hydraulic actuator operation.
2Productivity
If the pilot pressure is increased to maintain actuator performance at high engine loads, then the hydraulic pump output improves, but the energy consumption and system complexity increase
Solution Approach 1:
The pressure adjustment function is extracted from the main hydraulic pump control system and implemented as a separate, dedicated pressure adjustment valve in the drain oil path. This extraction allows independent control of pilot pressure without requiring the hydraulic pump to operate at higher energy consumption levels, as the pressure adjustment is achieved through flow restriction rather than increased pump output.
3Stability of the object's composition
If a pressure control valve is used to regulate pilot pressure, then the pilot pressure stability improves, but the device complexity and number of components increase
Solution Approach 1:
The pressure adjustment valve is designed to perform multiple functions: it restricts drain oil flow to maintain pilot pressure, operates automatically based on system conditions, and integrates into the existing drain oil path without requiring separate control systems. This multi-functionality achieves pressure stability without adding significant complexity to the overall hydraulic system.
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 the ease of operation and maintains the hydraulic actuators' performance by setting a secondary pilot pressure that allows for smooth operation even at higher engine loads, preventing reduced output and improving overall system efficiency.
Implementation Method 1
The pressure adjustment valve is provided in the drain oil path to adjust the pilot pressure to be less than the target pilot pressure when a condition is satisfied
Data Source
AI summary
A hydraulic system in a work machine includes a hydraulic pump to supply pilot hydraulic oil. A work hydraulic actuator is to move a work device of the work machine. A control valve is to control the work hydraulic actuator based on a pilot pressure of the pilot hydraulic oil. A target pilot pressure of the pilot hydraulic oil is input through the work operation device to control, according to the target pilot pressure, the pilot pressure supplied from the hydraulic pump to the control valve. A pilot oil path connects the work operation device and the control valve to supply the pilot pressure to the control valve. A drain oil path is divided from the pilot oil path. A pressure adjustment valve is provided in the drain oil path to adjust the pilot pressure to be less than the target pilot pressure when a condition is satisfied.