Shelf Stacker Dynamic Suspension for Lateral Stability

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Solution Overview

Problem

Shelf stackers with three-wheel suspension experience deteriorated lateral stability during pallet stacking and unloading, leading to elastic deflections and vibrations, which hinder efficient operation and increase construction costs due to the need for additional sensors and complex control systems.

Innovation Solution

The electronic control device triggers actuators to lower additional support means from a raised to a lowered position during vehicle standstill or load movement, transforming the three-wheel suspension into a five-wheel suspension, eliminating the need for additional sensors and reducing construction costs by providing continuous support and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a three-wheel suspension is used in the shelf stacker, then the construction cost is reduced and the device complexity is lowered, but the lateral stability deteriorates and elastic deflections increase

Engineering Contradiction:
Improvesuspension system complexityVSAvoidlateral stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The support means are made adjustable between a raised position (during movement) and a lowered position (during stacking operations). The electronic control device dynamically changes the suspension configuration based on operational phase, transitioning from a three-wheel to a five-wheel suspension when needed to improve lateral stability without permanently increasing complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The number of contact points with the ground is changed from three to five by lowering the support means. This parameter change in the suspension configuration allows the system to adapt the stability characteristic based on operational requirements while maintaining a simpler overall structure

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If additional support means are added to improve lateral stability, then the stability is improved, but the device complexity and construction cost increase

Engineering Contradiction:
Improvelateral stabilityVSAvoidsuspension system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Instead of permanently adding support wheels that would increase complexity, the patent uses movable support means that can be lowered only when needed during stacking operations. This dynamic activation provides stability improvement without permanently increasing the complex structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electronic control device automatically controls the support means based on operational status (movement vs. stacking), eliminating the need for manual intervention or complex mechanical linkages. The system self-adjusts the suspension configuration based on sensor input about the operational phase

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If the support means are lowered during stacking operations, then lateral stability is improved, but the transshipment time increases due to additional positioning steps

Engineering Contradiction:
Improvelateral stabilityVSAvoidtransshipment time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The support means are lowered in advance before stacking operations begin, ensuring that the stable five-wheel configuration is already in place when the load is positioned. This preliminary action eliminates delays during the actual stacking operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The electronic control device continuously monitors the operational status and keeps the support means in the optimal position throughout the stacking sequence. The system maintains continuous stability without interruption, allowing rapid transition through stacking phases without unnecessary positioning pauses

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3272699B1Shelf stacker
Publication Date: 2021.09.22 KION WAREHOUSE SYST
  • EP3272699B1 patent drawingFigure 1
  • EP3272699B1 patent drawingFigure 2
  • EP3272699B1 patent drawingFigure 3

AI summary

The invention relates to a stacker crane (1) with a load handling device that can be raised and lowered on a lifting frame, wherein the stacker crane (1) has a three-wheel chassis and is supported on a roadway by a steerable drive wheel (9) driven by a drive mechanism and two non-steered load wheels (8). The stacker crane (1) is provided with two lateral support elements (20), which are adjustably arranged on the stacker crane (1) between a position raised from the roadway, in which the support elements (20) have a clearance from the roadway, and a position lowered onto the roadway, in which the support elements (20) are in contact with the roadway. An actuator (21) is provided for adjusting the support elements (20) between the raised and lowered positions, and the actuators (21) of the support elements (20) are controlled by an electronic control unit.The load-handling device of the stacker (1) is movable in the transverse direction (Q) of the vehicle by means of a thrust drive. According to the invention, the electronic control unit (22) is designed such that, when the vehicle is stationary and/or during an extension movement of the load-handling device (6), the actuators (21) are controlled in such a way that the support elements (20) are actuated from the raised position to the lowered position.