Hydraulic Implement Pressure Control with Load-Sensing Pump Feedback

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Solution Overview

Problem

Conventional hydraulic systems for work vehicles face inefficiencies and excessive heat generation when operating implements that require pressure control, as they are unable to adapt to downstream pressure control, leading to pumps being operated at reduced efficiency and maximum pressure output.

Innovation Solution

A system that includes a loading sensing line to provide feedback on downstream pressure, allowing pump control based on the load or restriction, thereby improving efficiency and reducing heat generation by avoiding unnecessary maximum pressure output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional hydraulic system uses a flow control valve to provide constant flow rate, then the pump can be operated at maximum pressure output to maintain flow rate, but this leads to significantly reduced pump efficiency and excessive heat generation when the auxiliary hydraulic component requires lesser flow rate due to downstream pressure control

Engineering Contradiction:
Improveflow rateVSAvoidpump efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent introduces a load sensing line that provides feedback from the downstream side of the pressure control valve to the pump control mechanism. This feedback loop allows the pump to sense the actual pressure demand downstream and adjust its output accordingly, preventing the pump from operating at maximum pressure when lower pressure is sufficient, thereby improving pump efficiency and reducing energy loss

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from a static constant flow rate control to a dynamic pressure-responsive control. The flow control valve is modified to respond to downstream pressure conditions, allowing the system to dynamically adjust the pump's pressure output based on actual operational needs, which optimizes energy efficiency while maintaining required productivity

Inventive Principle:
Principle #15Dynamics

2Productivity

If the pump is operated at maximum pressure output to maintain constant flow rate through the flow control valve, then the flow rate can be maintained, but this leads to excessive heat generation in the hydraulic system

Engineering Contradiction:
Improveflow rateVSAvoidheat generation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The load sensing line provides real-time feedback on downstream pressure conditions to the pump control system. This feedback mechanism enables the pump to operate at the minimum necessary pressure to maintain the required flow rate, avoiding excessive pressure buildup that would generate unnecessary heat, thus controlling temperature while maintaining productivity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the operating parameters of the pump from fixed maximum pressure to variable pressure based on downstream demands. By dynamically adjusting pressure parameters according to actual load conditions, the system maintains required flow rates while minimizing energy dissipation as heat

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the vehicle's hydraulic system uses a flow control valve configured to provide constant flow rate, then the system can operate efficiently for components not requiring pressure control, but the system is unable to adapt to downstream pressure control when implements require constant down pressure mode

Engineering Contradiction:
Improvesystem adaptabilityVSAvoidpump efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The hydraulic system is enhanced with a load sensing line that provides universal adaptability to different operating conditions. The same basic hydraulic circuit can now accommodate both traditional constant flow applications and new pressure-controlled constant down pressure applications, making the system multi-functional without sacrificing pump efficiency in either mode

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

Solution Approach 2:

The load sensing line introduces feedback capability that allows the system to adapt to downstream pressure control requirements. By sensing pressure conditions downstream and communicating this information to the pump control, the system automatically adjusts its behavior to maintain optimal efficiency regardless of whether the implement requires constant flow or constant down pressure mode

Inventive Principle:
Principle #23Feedback

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

The system enhances hydraulic efficiency and reduces heat generation by allowing the pump to operate based on actual pressure demands, improving the operation of implements in constant down pressure modes.

Implementation Method 1

a loading sensing line to provide feedback on downstream pressure

Methodology Applied
Scientific EffectPressure feedback: Pressure Gradient

Data Source

PatentEP3196482B1System for controlling the supply of hydraulic fluid to a work vehicle implement
Publication Date: 2021.03.17 CNH IND ITALIA SPA
  • EP3196482B1 patent drawingFigure 1
  • EP3196482B1 patent drawingFigure 2
  • EP3196482B1 patent drawingFigure 3

AI summary

In one aspect, a system for controlling the supply of hydraulic fluid to an implement of a work vehicle may generally include a pump, a control valve coupled to the pump and first and second fluid lines provided in flow communication with output ports of the control valve. The system may also include a pressure control valve provided in flow communication with the second fluid line that is configured to regulate a fluid pressure of the hydraulic fluid being supplied to a hydraulic cylinder of the implement. Additionally, the system may include a bypass fluid line configured to provide a flow path for hydraulic fluid between the pump and the second fluid line that is independent of the control valve and a load sensing line configured to provide an indication of the fluid pressure of the hydraulic fluid being supplied to the hydraulic cylinder.