Hydraulic Lift Circuit for Faster Empty Load Handling

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Solution Overview

Problem

Current load handling machines have a fixed lifting speed regardless of the load, which limits the optimization of cycle times for lifting empty load handling members from heights.

Innovation Solution

A load handling machine design featuring a hydraulic cylinder with a safety valve and pressure-sensitive valve configuration, allowing fluid circulation from the lowering chamber to the lifting chamber, enhancing lifting speed by adding fluid flow from a hydraulic fluid source, and a unidirectional fluid circulation line with a non-return valve for efficient fluid transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fixed lifting speed system is used, then the system is simple and reliable, but the cycle time cannot be optimized for empty lifting operations

Engineering Contradiction:
Improvecycle timeVSAvoidhydraulic system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the lowering chamber and lifting chamber into a single hydraulic cylinder system, allowing fluid to circulate between chambers. This integration enables the system to reuse hydraulic fluid from lowering operations to assist in lifting operations, optimizing cycle times without requiring completely separate systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces dynamic control through a programmable controller that adjusts the opening degree of the first throttling member based on detected lifting speed. This dynamic adjustment allows the system to adapt lifting speed to operational needs, improving productivity while maintaining manageable complexity through automated control.

Inventive Principle:
Principle #15Dynamics

2Speed

If lifting speed is increased for empty load handling members, then cycle time is improved, but control precision and smoothness may be compromised

Engineering Contradiction:
Improvelifting speedVSAvoidlifting smoothness
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent incorporates a feedback mechanism where a detector monitors the actual lifting speed and sends signals to a programmable controller. The controller then adjusts the first throttling member's opening degree based on this feedback, creating a closed-loop control system that maintains smooth operation while achieving higher lifting speeds.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the flow resistance parameter dynamically by adjusting the opening degree of the first throttling member. This parameter adjustment allows the system to optimize lifting speed while maintaining control precision and operational smoothness through variable flow control.

Inventive Principle:
Principle #35Parameter changes

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 configuration increases the empty lifting speed of the load handling member, thereby improving cycle times in specific working conditions and allowing smooth lifting with loads without jerks.

Implementation Method 1

a safety valve open in the direction of circulation of fluid from the source of hydraulic fluid to the lifting chamber and normally closed in the direction of circulation from the lifting chamber to the source of hydraulic fluid

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a pressure-sensitive valve arranged on the second fluid connection, this valve being configured to move from the closed position to the open position depending on the pressure prevailing on the portion of the first fluid connection

Methodology Applied
Scientific EffectPressure sensitivity: Pressure Gradient

Implementation Method 3

a unidirectional and closable fluid circulation line connecting the first and second fluid connections for a loop circulation of fluid from the lowering chamber to the lifting chamber

Methodology Applied
Scientific EffectNon-return valve mechanism: Valve

Implementation Method 4

a hydraulic cylinder for lifting the or at least one of the load handling members, said lifting cylinder comprising a lifting chamber and a lowering chamber

Methodology Applied
Scientific EffectPascal's law: Pascal's Law

Data Source

PatentEP4178903B1Load-handling vehicle
Publication Date: 2024.03.06 MANITOU BF SA
  • EP4178903B1 patent drawingFigure 1
  • EP4178903B1 patent drawingFigure 2
  • EP4178903B1 patent drawingFigure 3

AI summary

Load-handling vehicle comprising: - a load-handling member, - a jack (4) for lifting the load-handling member, comprising a lifting chamber (5) and a lowering chamber (6), - a fluid source (7), - a first fluid connection (8) from the lifting chamber (5) to the source (7), - a second fluid connection (9) from the lowering chamber (6) to the source (7), - the first connection (8) comprising a safety valve (10) that is open in the direction of the fluid source (7) towards the lifting chamber (5), and that is normally closed in the direction of the lifting chamber (5) towards the fluid source (7). A valve (11) arranged on the second link (9) is sensitive to the pressure of the portion of the first link (8) extending between the valve (10) and the source (7), and a unidirectional fluid circulation line (12), which can be closed according to the pressure weighing on the portion of the second fluid connection (9) between the valve (11) and the source (7), connects the first and second connections (8, 9).