Forklift Flap Hinge Damping for Noise Reduction

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Solution Overview

Problem

Industrial trucks with electric drive systems face challenges in maintaining the flap in an open position without obstructing access or protruding from the vehicle contours, while existing solutions like latching devices are prone to high stress, noise, and complex implementation.

Innovation Solution

A friction force-generating damping device is integrated into the multi-joint hinge, utilizing multiple friction contacts between the hinge brackets and vehicle components to securely hold the flap in the open position, ensuring a robust, space-saving, low-noise, and cost-effective solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a multi-link hinge is used to achieve a 180° opening angle, then the flap can fold completely to the side without obstructing access, but the hinge structure becomes complex and space constraints make it difficult to implement robust holding devices

Engineering Contradiction:
Improveflap opening angleVSAvoidhinge structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the holding function with the hinge structure itself by integrating friction elements directly into the hinge brackets. Instead of adding separate holding devices, the friction-bearing surfaces are incorporated into the existing hinge components, merging the holding function with the hinge structure to avoid additional complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces friction elements as intermediary components between the hinge brackets and the vehicle structure. These friction elements act as mediators that enable the holding function through frictional contact, allowing the flap to be held in the open position without requiring complex mechanical linkages or protruding structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a detent device or latch is used to hold the flap in the open position, then the flap can be secured, but the device requires robust design to withstand high kinetic energy engagement and produces noise

Engineering Contradiction:
Improveflap holding capabilityVSAvoidnoise and material stress
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of kinetic energy engagement into a beneficial friction-based holding mechanism. Instead of using a detent device that engages with high impact forces, the friction elements continuously maintain contact with the hinge brackets, converting the potential harmful impact into a smooth, continuous frictional force that holds the flap without noise or material stress.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If a gas spring is used to hold the flap in the open position, then the holding capability is sufficient, but the device protrudes laterally from the vehicle contour

Engineering Contradiction:
Improveflap holding capabilityVSAvoidvehicle contour
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent merges the holding function with the hinge structure by integrating friction elements directly into the hinge brackets. This eliminates the need for separate gas spring devices that would protrude from the vehicle contour, as the holding capability is achieved within the existing hinge assembly footprint.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If multiple friction contacts are implemented to securely hold the flap, then the holding reliability improves, but the device complexity increases

Engineering Contradiction:
Improveflap holding reliabilityVSAvoidfriction contact structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent achieves multiple friction contacts by integrating them directly into the hinge brackets and vehicle structure. Instead of adding separate components for each friction contact, the friction surfaces are merged with the existing hinge components, creating multiple contact points without proportionally increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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

The damping device effectively holds the flap open, preventing unintended closure and ensuring safe access to the energy supply unit, reducing material stress and noise, while being easy to integrate and adjust, thus enhancing operational safety and efficiency.

Implementation Method 1

a friction-generating damping device (20) is integrated into the multi-joint hinge (15), which has at least one frictional contact (21a-21d) formed between one of the two brackets (16, 17) of the multi-joint hinge (15) and a vehicle-mounted component (22)

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3333117B1Industrial truck, especially electrically operated industrial truck
Publication Date: 2019.09.11 STILL GMBH
  • EP3333117B1 patent drawingFigure 1
  • EP3333117B1 patent drawingFigure 2

AI summary

The invention relates to a forklift truck (1), in particular an electrically operated forklift truck, with a lateral frame opening for receiving a power supply unit, in particular a traction battery, and a flap (10) provided for covering the frame opening, which is movable between a closed position and an open position by means of a multi-joint hinge (15), in particular a four-joint hinge, wherein the multi-joint hinge (15) has a first bracket (16) and a second bracket (17), wherein the first bracket (16) is pivotably mounted on a first fixed pivot axis (D1) and on a first movable joint axis (G1) and the second bracket (17) is pivotably mounted on a second fixed pivot axis (D2) and on a second movable joint axis (G2). The multi-joint hinge (15) is provided with a friction-generating damping device (20) that holds the flap (10) in the open position.