Hydraulic Confluence Valve for Load Sensing Efficiency

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Solution Overview

Problem

The existing constant power controlled load sensing hydraulic systems face inefficiencies and energy loss due to slow actuator action and high pressure spikes when starting to overcome large external loads, leading to reduced productivity and energy wastage.

Innovation Solution

A hydraulic apparatus implementing confluence control with a load sensing unit and throttle governing unit, utilizing a confluence valve with parallel oil paths and pilot pressures to shunt fluid from the throttle governing unit to the load sensing unit, matching fluid resistance with external loads and preventing sudden pressure spikes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If constant power control is adopted in load sensing hydraulic system, then power source efficiency is improved, but actuator action speed deteriorates when starting to overcome large external loads

Engineering Contradiction:
Improvepower source energy lossVSAvoidactuator action speed
Core Design Contradiction:
Loss of energyVSSpeed

Solution Approach 1:

The invention dynamically switches between throttle governing mode and load sensing mode based on operational conditions. During startup when actuators need to overcome large external loads, the system operates in throttle governing mode which provides high flow and maintains fast actuator action. During normal operation, it switches to load sensing mode for energy efficiency. This dynamic mode switching resolves the contradiction between energy efficiency and actuator response speed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The confluence valve acts as an intermediary that merges oil paths from both throttle governing unit and load sensing unit. It directs oil flow based on operational needs: during startup, it channels oil through the throttle governing unit to ensure fast actuator response, while during normal operation, it directs flow through the load sensing unit for energy efficiency. This intermediary mechanism allows the system to achieve both fast response and energy efficiency at different times.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If variable displacement piston pump controls pressure based on maximum load pressure, then system pressure is maintained, but productivity deteriorates due to slow actuator response

Engineering Contradiction:
Improvesystem pressure controlVSAvoidactuator productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts pressure control strategy based on operational phase. During startup, the throttle governing unit provides unrestricted high flow to ensure fast actuator response and high productivity. During normal operation, the load sensing unit takes over pressure control to maintain system pressure reliability. This dynamic adjustment of control strategy resolves the contradiction between pressure control reliability and productivity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention segments the pressure control function into two separate units: throttle governing unit for high-flow startup conditions and load sensing unit for normal pressure control. Each unit handles specific operational phases, allowing the system to maintain both fast response during startup and reliable pressure control during operation without compromise.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If load sensing hydraulic system is used, then energy efficiency is improved, but system complexity increases due to additional components

Engineering Contradiction:
Improveenergy consumptionVSAvoidhydraulic system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The invention merges throttle governing unit and load sensing unit into a single integrated hydraulic system with a common oil source and confluence valve. This combination allows the system to leverage the energy efficiency of load sensing while incorporating the simple, fast-response characteristics of throttle governing during startup. The merged system achieves energy efficiency without requiring a complete redesign, thus limiting the increase in complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The confluence valve serves multiple functions: it merges oil paths from both units, directs flow based on operational mode, and enables the system to operate in either throttle governing or load sensing mode. This multi-functionality allows a single component to provide the benefits of both systems while minimizing the need for additional specialized components, thus limiting complexity increase.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 efficiency and reduces energy loss by ensuring actuators operate effectively under varying loads without excessive pressure increases, maintaining high productivity and minimizing energy wastage.

Implementation Method 1

the confluence valve being provided with a confluence channel that controls opening and closing of the parallel oil path to shunt fluid of the throttle governing unit to the load sensing unit

Methodology Applied
Scientific EffectHydraulic pressure control: Hydraulic Press

Implementation Method 2

a one-way valve, which are communicated with the load sensing unit and the throttle governing unit

Methodology Applied
Scientific EffectOne-way flow control: Valve

Implementation Method 3

when the first directional valve reverses due to a first pilot pressure thereof acting thereon, when the second directional valve reverses due to a second pilot pressure thereof acting thereon

Methodology Applied
Scientific EffectPilot pressure control: Valve

Data Source

PatentEP2947331B1Hydraulic apparatus based on confluence control mode
Publication Date: 2020.04.15 JIANGSU HENGLI HYDRAULIC
  • EP2947331B1 patent drawingFigure 1
  • EP2947331B1 patent drawingFigure 2

AI summary

A hydraulic apparatus based on a confluence control mode, comprising a load sensing unit provided with a first and a second reversing valves (1, 2), and a throttle governing unit provided with a fourth reversing valve (3). A confluence valve (5) and a one-way valve (6), which are communicated with the load sensing unit and the throttle governing unit, are arranged on a parallel oil path arranged in parallel with the fourth reversing valve (3). The confluence valve (5) is provided with a confluence channel (50) that controls opening and closing of the parallel oil path to shunt fluid of the throttle governing unit to the load sensing unit. A first pilot pressure (P1) acting on the first reversing valve (1) and a second pilot pressure (P2) acting on the second reversing valve (2) act on the confluence valve (5) independently or simultaneously to change a position of the confluence channel (50), thus implementing reversing of the confluence valve (5). With the confluence valve (5) being configured to be communicated with the load sensing unit and the throttle governing unit, a flow of the throttle governing unit can be shunted to the load sensing unit in time, thus avoiding the occurrence that an executive element in a system is slow in action, low in efficiency, and consumes energy of a hydraulic motor, and enabling the system to run with high efficiency and low energy consumption.