Hydraulic Cylinder Piston Rod Speed Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing industrial truck hydraulic systems lack precision in regulating the movement of loads due to external influences such as pulling loads, oil viscosities, and temperature changes, leading to deviations between actual and desired speed and acceleration.

Innovation Solution

A control unit is implemented to specify target speed and acceleration for the piston rod of hydraulic cylinders, with sensor units measuring actual speed and acceleration, allowing for real-time adjustments to maintain precise movement control, thereby compensating for external disturbances and simplifying the hydraulic system structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional hydraulic systems are used to regulate load movement, then the system structure remains simple, but the speed control precision is insufficient due to external influences

Engineering Contradiction:
Improvespeed control precisionVSAvoidsystem structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a feedback control system where sensors continuously measure the actual speed and acceleration of the load, and the control unit compares these values with target values. Based on the deviation detected, the control unit automatically adjusts hydraulic valve openings to correct the movement parameters, thereby achieving precise speed and acceleration control despite external disturbances.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces conventional mechanical speed control mechanisms with an electronic control system. The control unit uses electronic signals to regulate hydraulic valves based on sensor feedback, substituting purely mechanical regulation with an electromechanical control approach that offers superior precision and responsiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If hydraulic valve openings are adjusted to control speed, then the load speed can be regulated, but external influences cause deviation from desired speed and acceleration

Engineering Contradiction:
Improvemovement control reliabilityVSAvoidspeed and acceleration accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The control system continuously monitors actual speed and acceleration through sensors and compares them with target values. When deviations are detected caused by external influences such as load variations or friction changes, the control unit automatically adjusts the hydraulic valve openings to compensate, ensuring reliable and accurate movement control throughout the operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts hydraulic valve openings in real-time based on current operating conditions and detected deviations. This dynamic control approach allows the system to adapt to changing external influences during operation, maintaining reliable and accurate speed and acceleration control rather than relying on fixed mechanical settings.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If multiple hydraulic cylinders operate simultaneously, then complex movements can be achieved, but coordination stability becomes difficult to maintain

Engineering Contradiction:
Improvesimultaneous movement capabilityVSAvoidcoordination stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The control unit receives feedback from sensors monitoring each hydraulic cylinder's actual speed and acceleration. Based on this feedback, the control unit independently adjusts the valve openings for each cylinder to maintain coordination and stability during simultaneous operations, ensuring that complex multi-cylinder movements remain synchronized and stable.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control unit serves multiple functions by simultaneously managing several hydraulic cylinders through a single integrated control system. It can independently regulate each cylinder's movement while maintaining overall coordination, providing versatile control capability for complex simultaneous movements without requiring separate control systems for each cylinder.

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

Data Source

PatentEP3336050B1Industrial truck with a control unit for regulating the movement of a piston rod of a hydraulic cylinder and such a method
Publication Date: 2019.11.13 JUNGHEINRICH AG
  • EP3336050B1 patent drawingFigure 1
  • EP3336050B1 patent drawingFigure 2
  • EP3336050B1 patent drawingFigure 3

AI summary

Industrial truck comprising a lifting frame with a load-bearing element, a hydraulic system comprising at least one hydraulic cylinder with a piston rod and a cylinder housing, and a hydraulic power unit, wherein the at least one hydraulic cylinder acts on the lifting frame via the piston rod, at least one sensor unit configured to determine an actual speed and/or an actual acceleration of the piston rod of the at least one hydraulic cylinder, and a control unit configured to specify a target speed and/or a target acceleration for the piston rod of the at least one hydraulic cylinder.to determine a control deviation of the actual speed determined by the at least one sensor unit from the target speed and/or the actual acceleration determined by the at least one sensor unit from the target acceleration and to control the movement speed and/or the acceleration of the piston rod based on the determined control deviation.