Hydraulic Pressure Rail Control With Accumulators for Lower Throttling Loss

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Solution Overview

Problem

Current hydraulic systems for work machines, such as excavators, face inefficiencies due to inability to optimize pressure in high- and medium-pressure rails in real-time to match load demands, leading to throttling losses and energy waste.

Innovation Solution

A hydraulic arrangement with a common pressure rails configuration, including multiple parallel hydraulic lines and accumulators, is enhanced by control valves and sensing mechanisms to dynamically regulate pressure levels within the system, allowing for precise and quick adaptation to load demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional directional proportional control valves are used to control hydraulic actuators, then precise control of each hydraulic actuator is achieved, but a great deal of hydraulic fluid is routed back to tank causing energy waste

Engineering Contradiction:
Improveprecise controlVSAvoidenergy waste
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent extracts the throttling function from the traditional proportional control valves and replaces it with a logic valve system that directs hydraulic fluid based on binary decisions rather than continuous modulation. This removes the energy-wasting throttling mechanism while preserving control capability through a different approach.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses feedback from load sensing and position sensors to dynamically adjust valve actuation decisions. The control system monitors actual load conditions and actuator positions, then adjusts which accumulators are connected to which actuators in real-time, optimizing energy recovery and utilization based on actual system state.

Inventive Principle:
Principle #23Feedback

2Loss of energy

If common pressure rails configuration with accumulators is used, then energy recovery is enabled, but inability to optimize pressure in real-time leads to throttling losses

Engineering Contradiction:
Improveenergy recoveryVSAvoidreal-time pressure optimization
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic pressure optimization by using logic valves that can rapidly connect and disconnect different accumulators to different hydraulic actuators based on real-time load conditions. The system transitions from static pressure rails to a dynamically reconfigurable hydraulic network that adapts pressure distribution to match actual load demands.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the pressure parameter dynamically by selectively connecting accumulators at different pressure levels to different actuators. The logic valve system enables rapid switching between high-pressure and medium-pressure accumulators based on load requirements, optimizing pressure delivery and minimizing throttling losses.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If multiple accumulators are used in parallel to store pressurized hydraulic fluid, then energy storage capacity is increased, but pressure distribution cannot be optimized to match load demands

Engineering Contradiction:
Improvehydraulic fluid storageVSAvoidpressure distribution optimization
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent segments the hydraulic system into multiple independent pressure zones by using logic valves to selectively connect different accumulators to different actuators. Each accumulator operates as an independent energy storage unit that can be activated based on specific load conditions, allowing optimized pressure distribution across the hydraulic network.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The logic valve system acts as an intermediary between the multiple accumulators and the hydraulic actuators. It intelligently decides which accumulators should be connected to which actuators based on load sensing and position feedback, enabling optimized pressure distribution without requiring continuous modulation of valve openings.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables efficient energy use by minimizing throttling losses and optimizing pressure distribution, reducing fuel consumption and improving the responsiveness of hydraulic actuators to load changes.

Implementation Method 1

a first hydraulic accumulator (27) fluidly connected to said first line (21a) and a second hydraulic accumulator (28) fluidly connected to said second line (21b)

Methodology Applied
Scientific EffectHydraulic Accumulator: Hydraulic Accumulator

Data Source

PatentEP4491809A1Improved hydraulic arrangement for a work machine, control method thereof, and work machine comprising such hydraulic arrangement
Publication Date: 2025.01.15 CNH IND ITALIA SPA
  • EP4491809A1 patent drawingFigure 1
  • EP4491809A1 patent drawingFigure 2
  • EP4491809A1 patent drawingFigure 3

AI summary

A hydraulic arrangement (14, 214) for a work machine (1) comprising: a body (2) and a hydraulically actuated work implement (6); said hydraulic arrangement (14) comprises: pumping means (17) to suck hydraulic fluid from a tank (18) and to provide at outlet a pressurized flow of hydraulic fluid; one actuator (7) to operate the hydraulically actuated work implement (6); a hydraulic circuit (20) to put the source of hydraulic fluid (17) in communication with the hydraulic actuator (7); and a control valve arrangement (22) to selectively put the hydraulic circuit (20) in fluid communication with the hydraulic actuator (7); the hydraulic circuit (20) comprises: a first hydraulic line (21a) connecting the pumping means (17) with the actuator (7); a second hydraulic line (21c) connecting the tank (18) with the actuator (7); one hydraulic accumulator (26, 28) fluidly connected to the first hydraulic line (21a); the hydraulic accumulator (26, 28) comprises a first chamber (31a) connected to the first hydraulic line (21a) and a second preload chamber (31b), opposite to the first chamber (31a), connected to pumping means (17).