Hydraulic Flow Summation Valve for Stable Multi-Circuit Pressure

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Solution Overview

Problem

Existing hydraulic systems in vehicles face challenges in efficiently managing hydraulic fluid flow to multiple subsystems, leading to inefficiencies and potential pressure imbalances.

Innovation Solution

A hydraulic system with a priority valve and summation valve configuration, utilizing two pumps to manage fluid flow to steering, transmission, and auxiliary subsystems, with feedback mechanisms to stabilize pressure and flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single pump is used to supply hydraulic fluid to multiple subsystems, then the system structure is simple, but pressure imbalances and flow distribution inefficiencies occur

Engineering Contradiction:
Improvesystem structureVSAvoidhydraulic fluid distribution efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The hydraulic system is segmented into multiple independent pump units (first pump and second pump), each responsible for specific subsystems. The first pump supplies the steering subsystem through the priority valve, while the second pump supplies auxiliary subsystems through the summation valve, enabling independent flow control and eliminating pressure imbalances between different hydraulic circuits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The summation valve acts as an intermediary component that combines hydraulic flow from multiple sources. It receives flow from the first pump via the priority valve and flow from the second pump, then merges these flows to supply the auxiliary subsystem, enabling efficient flow distribution without direct connection between pumps.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If multiple pumps are used to supply hydraulic fluid to multiple subsystems, then flow distribution efficiency improves, but the system becomes more complex

Engineering Contradiction:
Improvehydraulic fluid distribution efficiencyVSAvoidsystem structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The priority valve and summation valve are merged into a coordinated control system where the priority valve handles steering subsystem requirements first, and the summation valve combines remaining flow from the first pump with flow from the second pump. This merging approach allows multiple pumps to work together efficiently without requiring complex independent control systems for each pump.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system implements feedback control through the priority valve and summation valve configuration, where pressure and flow conditions in the hydraulic system automatically regulate the distribution of fluid from multiple pumps. The valves respond to system demands and adjust flow distribution accordingly, eliminating the need for complex electronic control systems.

Inventive Principle:
Principle #23Feedback

3Reliability

If hydraulic flow is prioritized for one subsystem, then that subsystem receives optimal performance, but other subsystems experience reduced flow availability

Engineering Contradiction:
Improvesteering subsystem performanceVSAvoidhydraulic fluid flow availability
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The priority valve is configured to first satisfy the hydraulic flow requirements of the steering subsystem before allowing flow to pass through to other subsystems. This preliminary action ensures that critical steering operations always receive adequate hydraulic flow, while auxiliary subsystems receive remaining flow capacity without compromising steering performance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The summation valve serves multiple functions: it combines flow from the first pump with flow from the second pump, distributes combined flow to auxiliary subsystems, and maintains system pressure balance. This multi-functionality allows a single valve to handle complex flow distribution tasks that would otherwise require multiple separate control components.

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

Ensures stable and efficient hydraulic fluid distribution to multiple subsystems, maintaining optimal operating conditions and reducing response fluctuations.

Implementation Method 1

a priority valve (106) including a priority inlet (108) fluidly coupled to the first pump, a primary outlet (112) fluidly coupled to the first hydraulic outlet, and a secondary outlet (114) fluidly coupled to the second hydraulic outlet

Methodology Applied
Scientific EffectHydraulic flow prioritization: Pressure Gradient

Implementation Method 2

a summation valve (130) including a summation inlet (132) fluidly coupled to the second pump, a return outlet (138) fluidly coupled to the priority inlet (108) of the priority valve (106), an auxiliary outlet (140) fluidly coupled to the third hydraulic outlet

Methodology Applied
Scientific EffectHydraulic flow summation: Fluid Spray

Implementation Method 3

with feedback mechanisms to stabilize pressure and flow rates

Methodology Applied
Scientific EffectPressure feedback control: Feedback

Data Source

PatentEP4471297B1Hydraulic flow summation valve control system
Publication Date: 2026.03.25 CNH IND ITALIA SPA
  • EP4471297B1 patent drawingFigure 1~2
  • EP4471297B1 patent drawingFigure 3
  • EP4471297B1 patent drawingFigure 4

AI summary

A vehicle includes a chassis and a hydraulic system. The hydraulic system is configured to facilitate operation of the vehicle. The hydraulic system includes a first hydraulic outlet (200), a second hydraulic outlet (300), a third hydraulic outlet (400), a first pump (104) configured to produce a first flow, a second pump (120) configured to produce a second flow, a priority valve (106), and a summation valve (130). The priority valve (106) includes a priority inlet (108) fluidly coupled to the first pump (104), a primary outlet (112) fluidly coupled to the first hydraulic outlet (200), and a secondary outlet (114) fluidly coupled to the second hydraulic outlet. The summation valve includes a summation inlet (132) fluidly coupled to the second pump, a return outlet (138) fluidly coupled to the priority inlet of the priority valve, an auxiliary outlet (140) fluidly coupled to the third hydraulic outlet (400), and a first control input (134) coupled to the secondary outlet (114) of the priority valve.