Quick Coupler Valve Sequencing Prevents Hydraulic Leakage

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Solution Overview

Problem

Existing quick-change devices for coupling tools to work machines, such as excavators, face the issue of hydraulic fluid leakage due to automated opening of the excavator-side coupling part when the tool-side coupling part is malfunctioning or contaminated, leading to operational inefficiencies and potential contamination.

Innovation Solution

The implementation of active, energy-actuated clutch valves on both the quick-change device and adapter sides, where the adapter-side valves open first, followed by the quick-change side valves, ensuring hydraulic fluid flow only after the adapter-side valves are open, preventing fluid escape in case of malfunctions and ensuring correct tool coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If automated opening of the excavator-side coupling part is implemented, then hydraulic coupling is achieved automatically without manual intervention, but hydraulic fluid escapes significantly when the tool-side coupling part is defective or contaminated

Engineering Contradiction:
Improveautomated hydraulic couplingVSAvoidhydraulic fluid escape
Core Design Contradiction:
Extent of automationVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by opening the adapter-side coupling part first before opening the excavator-side coupling part. This sequence ensures that the tool-side hydraulic circuit is prepared and ready to receive hydraulic fluid before the excavator-side valves open, preventing fluid escape in case the tool-side coupling part is defective or contaminated.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by monitoring the opening status and operational state of the adapter-side coupling part. The control system uses this information to determine whether to proceed with opening the excavator-side coupling part, thereby preventing fluid leakage when the tool-side component is malfunctioning.

Inventive Principle:
Principle #23Feedback

2Speed

If the excavator-side coupling part opens automatically, then coupling speed is improved, but hydraulic fluid leakage occurs due to defects or contamination in the tool-side coupling part

Engineering Contradiction:
Improvecoupling speedVSAvoidhydraulic fluid containment
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent maintains fast automated coupling while improving reliability by implementing a two-stage opening sequence. The adapter-side coupling part opens first as a preliminary action, allowing the system to verify proper tool-side functionality before the excavator-side coupling part opens, thus preventing fluid leakage while maintaining coupling speed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control system uses feedback from the adapter-side coupling part's opening status to determine whether to proceed with opening the excavator-side coupling part. This feedback mechanism ensures that hydraulic fluid is only released when the tool-side circuit is properly prepared, maintaining both speed and reliability.

Inventive Principle:
Principle #23Feedback

3Productivity

If clutch valves are opened simultaneously on both sides, then hydraulic connection is established quickly, but fluid escape occurs when tool-side coupling part is malfunctioning

Engineering Contradiction:
Improvehydraulic connection speedVSAvoidhydraulic fluid loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent segments the valve opening process into two distinct stages: first opening the adapter-side clutch valves, then opening the excavator-side clutch valves. This segmentation allows the system to verify proper tool-side functionality before releasing hydraulic fluid, maintaining productivity while preventing fluid loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adapter-side clutch valves are opened as a preliminary action before opening the excavator-side clutch valves. This ensures that the tool-side hydraulic circuit is prepared and able to receive fluid before the main hydraulic connection is established, preventing fluid escape while maintaining fast connection speed.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2378005B1Quick coupler for coupling a tool to a work machine
Publication Date: 2014.01.01 LEHNHOFF HARTSTAHL GMBH & CO KG
  • EP2378005B1 patent drawingFigure 1
  • EP2378005B1 patent drawingFigure 2
  • EP2378005B1 patent drawingFigure 3

AI summary

The device has a quick-changer (16) attached at a work machine, and an adapter (18) attached at a tool e.g. screening bucket, swivel bucket and hydraulic breaker. A locking device acts between the quick-changer and adapter and produces a mechanical coupling between the work machine and tool. Quick-changer sided coupling valves and adapter-sided coupling valves are controlled after production of the mechanical coupling between the work machine and the tool such that the adapter-sided and quick-change sided valves are actively opened in order during supply of energy.