Hydraulic Flow Control for Option Actuator Protection

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Solution Overview

Problem

Hydraulic machines face challenges in maintaining optimal workability while preventing damage to option actuators, as existing systems often supply working fluid at insufficient flow rates when multiple manipulators are used, leading to reduced performance and potential actuator damage due to excessive flow rates.

Innovation Solution

A hydraulic machine design featuring a first and second working fluid supply, flow control valves, and a confluence path that allows fluid combination, with a controller adjusting flow rates to ensure the first supply operates at its capacity and the second supply contributes only when necessary, preventing excessive flow to the option actuator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the second working fluid supply is controlled to discharge working fluid at a flow rate obtained by deducing the first capacity from the first maximum allowable flow rate when the first maximum allowable flow rate is higher than the first capacity, then the option actuator receives the required flow rate without damage, but the workability is reduced because the second supply cannot contribute its full capacity

Engineering Contradiction:
Improveoption actuator protectionVSAvoidworkability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The controller dynamically adjusts the flow rate control based on the relationship between the first maximum allowable flow rate and the first capacity. When the first maximum allowable flow rate is not higher than the first capacity, the second working fluid supply discharges at its full capacity. When the first maximum allowable flow rate is higher than the first capacity, the second supply discharges at a reduced flow rate (first maximum allowable flow rate minus first capacity). This dynamic adjustment resolves the contradiction by optimizing both actuator protection and workability based on real-time conditions.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the first working fluid supply is controlled to discharge working fluid at a flow rate equal to the first capacity, then the option actuator receives sufficient flow rate for improved workability, but the risk of excessive flow rate damaging the option actuator increases

Engineering Contradiction:
ImproveworkabilityVSAvoidactuator damage risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The controller acts as an intermediary between the first and second working fluid supplies and the option actuator. It calculates and controls the flow rates of both supplies based on the relationship between the first maximum allowable flow rate and the first capacity. By coordinating the discharge of both supplies, the controller ensures that the total flow rate to the option actuator does not exceed the first maximum allowable flow rate, thus preventing damage while maximizing workability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If multiple manipulators are operated simultaneously for combined operations, then the workability is improved, but the flow rate control becomes complex and may lead to insufficient or excessive flow rates

Engineering Contradiction:
Improvecombined operation capabilityVSAvoidflow rate control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The controller continuously monitors the flow rates of the first and second working fluid supplies and adjusts them based on the relationship between the first maximum allowable flow rate and the first capacity. This feedback mechanism ensures that even during combined operations of multiple manipulators, the total flow rate to the option actuator remains within safe limits while maximizing the contribution of both supplies, thus simplifying the control complexity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3724409B1Hydraulic machine
Publication Date: 2025.03.26 VOLVO CONSTRUCTION EQUIPMENT AB
  • EP3724409B1 patent drawingFigure 1
  • EP3724409B1 patent drawingFigure 2
  • EP3724409B1 patent drawingFigure 3

AI summary

A first required flow rate is calculated as a function of a first maximum allowable flow rate and a value of a first signal. A second required flow rate is calculated as a function of a value of the second signal. When the first maximum allowable flow rate is higher than a first capacity, the value of the first signal is a maximum level, and the value of the second signal is equal to or higher than a minimum level and equal to or lower than a maximum level, a first working fluid supply is controlled to discharge working fluid at a flow rate equal to the first capacity, and a second working fluid supply is controlled to discharge working fluid at a flow rate obtained by deducting the first capacity from the first maximum allowable flow rate, added to the second required flow rate.