Hydraulic Position Memory Circuit for Folding Farm Machines

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Solution Overview

Problem

Existing hydraulic systems in agricultural machinery fail to efficiently and precisely memorize and retrieve the position of hydraulic cylinders, leading to repeated adjustment maneuvers and loss of settings during folding or unfolding, especially when repositioning is necessary.

Innovation Solution

A hydraulic circuit with a separate hydraulic storage cylinder and a memory pilot/distribution unit that transfers and stores the oil volume corresponding to a specific position, allowing for precise retrieval of the cylinder position, even after repositioning, using the principle of volume conservation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a traditional hydraulic circuit is used without a memory function, then the device complexity is low, but the position setting is lost during folding or unfolding operations

Engineering Contradiction:
Improveposition settingVSAvoidhydraulic circuit complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The memory cylinder is integrated into the existing hydraulic circuit as a nested component. The memory cylinder receives and stores hydraulic fluid from the main cylinder during folding/unfolding operations, then returns the fluid to restore the original position. This nesting approach adds memory functionality without requiring a completely separate hydraulic system.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The memory cylinder is pre-configured with the capability to store hydraulic fluid at specific volumes corresponding to desired positions. During folding or unfolding, the system automatically transfers fluid to the memory cylinder to preserve the position setting before the main cylinder retracts, ensuring the position information is preserved in advance.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If a master-slave cylinder system with memory chamber is used, then the position can be memorized, but the memory function becomes non-operational when the entire rod must be retracted

Engineering Contradiction:
Improveposition settingVSAvoidmemory function availability
Core Design Contradiction:
Loss of informationVSAdaptability or versatility

Solution Approach 1:

The hydraulic system is segmented into two independent but interconnected cylinders: the main cylinder for position adjustment and the memory cylinder for position preservation. This segmentation allows the memory cylinder to independently store hydraulic fluid volume corresponding to the main cylinder position, enabling memory functionality to operate even when the main cylinder is fully retracted.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The memory cylinder acts as an intermediary between the main cylinder and the hydraulic fluid reservoir. It temporarily holds the hydraulic fluid that represents the position setting, mediating the transfer of fluid during folding/unfolding operations to preserve position information even when the main cylinder cannot maintain its position.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of moving object

If hydraulic cylinders are fully retracted during folding, then the transport dimensions are reduced, but the working depth setting is lost

Engineering Contradiction:
Improvetransport dimensionsVSAvoidworking depth setting
Core Design Contradiction:
Length of moving objectVSLoss of information

Solution Approach 1:

The position setting information is extracted from the physical position of the main cylinder and stored as a volume of hydraulic fluid in the memory cylinder. This extraction allows the main cylinder to be fully retracted for compact transport while the position information remains preserved in the memory cylinder as a stored fluid volume.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes the parameter representation of the position setting from a spatial parameter (cylinder extension length) to a volumetric parameter (hydraulic fluid volume in memory cylinder). This parameter transformation enables the position to be preserved independently of the main cylinder's physical position during folding operations.

Inventive Principle:
Principle #35Parameter changes

4Loss of information

If adjustment maneuvers are repeated after folding, then the position can be restored, but time is lost due to repeated adjustments

Engineering Contradiction:
Improveposition settingVSAvoidadjustment time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The memory cylinder provides self-service functionality by automatically storing the hydraulic fluid volume corresponding to the main cylinder position during folding operations. When unfolding, the system automatically retrieves the stored fluid volume to restore the position, eliminating the need for manual adjustment maneuvers and associated time losses.

Inventive Principle:
Principle #25Self-service

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

Enables easy, quick, and precise retrieval of hydraulic cylinder positions, minimizing time loss and ensuring consistent settings across multiple machine elements without the need for additional components like flow dividers.

Implementation Method 1

a memory circuit hydraulically connected to said main hydraulic circuit, said memory circuit comprising a storage cylinder comprising a piston dividing the storage cylinder into a first chamber and a second chamber, said first chamber being hydraulically connected to said first chamber of said main hydraulic cylinder

Methodology Applied
Scientific EffectHydraulic fluid transfer: Hydraulic Press

Implementation Method 2

allowing for precise retrieval of the cylinder position, even after repositioning, using the principle of volume conservation

Methodology Applied
Scientific EffectVolume conservation:

Data Source

PatentEP3964719B1Hydraulic circuit for an agricultural machine and associated agricultural machine
Publication Date: 2025.11.05 KUHN SA
  • EP3964719B1 patent drawingFigure 1
  • EP3964719B1 patent drawingFigure 2
  • EP3964719B1 patent drawingFigure 3

AI summary

The present invention relates to a hydraulic circuit for an agricultural machine, comprising a machine element actuated by a main hydraulic cylinder 1, comprising: - a main hydraulic circuit comprising: said main hydraulic cylinder (1) having at least one cylinder (2) comprising a first chamber (3) and a second chamber (4), which are separated from each other by a piston (5), and, said piston (5) being movable between an initial position (P1) to be memorized for which the first chamber (3) is capable of containing a volume of oil to be memorized (V1) and an intermediate position (P2) for which the first chamber (3) is capable of containing any volume of oil (V2) different from the volume of oil to be memorized (V1), - a memory hydraulic circuit hydraulically connected to said main hydraulic circuit comprising: a storage cylinder (8) comprising at least one first storage chamber (9),characterized in that said storage cylinder (8) is a separate entity from cylinder (2), and the first storage chamber (9) is hydraulically connected to said first chamber (3), such that said volume of oil to be stored (V1) contained in the first chamber (3) corresponding to the initial position (P1) of piston (5) is transferred into the first storage chamber (9) of said storage cylinder (8) to store the initial position (P1) during the movement of said piston (5) from the initial position (P1) to the intermediate position (P2) of said piston (5).