Vehicle Floor Element Flat Underside Foam Expansion
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Solution Overview
Problem
The existing construction methods for floor elements in refrigerated vehicles face challenges in efficiently producing cost-effective, high-productivity floor elements with optimal thermal insulation and weight minimization, particularly when using flowable foam that expands and hardens in place, which complicates assembly and requires expensive tools to compensate for length deviations.
Innovation Solution
A floor element design with a flat underside and minimal thickness variations, allowing for easy insertion into a pressing tool, where the foam can expand and harden without deforming the element, and all surface elements are integrated into the lower cover layer, eliminating the need for complex rework and allowing for parallel production and simple assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If flowable foam is used that expands and hardens in place, then production cost is reduced, but assembly complexity increases and requires expensive pressing tools
Solution Approach 1:
The lower cover layer is designed with a flat underside before foam application, establishing a stable base that will accommodate foam expansion. The pressing tool is prepared in advance with a corresponding flat pressing surface, ensuring that when the flowable foam expands and hardens in place, the floor element maintains its shape without requiring complex adjustment mechanisms during assembly.
Solution Approach 2:
The invention changes the physical state parameters of the foam material by applying it in a flowable liquid state that subsequently expands and hardens. This parameter transformation allows the foam to adapt to the chamber shape automatically, reducing the need for precise pre-positioning and complex assembly tools, thereby resolving the contradiction between cost reduction and assembly complexity.
2Manufacturing precision
If the floor element is pressed during foam hardening, then foam expansion is controlled, but length deviations require expensive compensating tools
Solution Approach 1:
The pressing tool utilizes temperature parameter changes to control foam expansion during hardening. By adjusting the temperature of the pressing surfaces, the foam's viscosity and expansion rate are controlled, allowing precise dimensional control without requiring complex mechanical compensation mechanisms for length deviations, thereby reducing tool costs.
Solution Approach 2:
The pressing tool is designed with predetermined pressing surfaces that account for expected foam expansion. The flat pressing surfaces are positioned and dimensioned in advance to compensate for normal expansion variations, eliminating the need for expensive adjustable or compensating mechanisms during the actual pressing operation.
3Strength
If multiple thickness zones are created in the lower cover layer, then structural strength is improved, but the underside becomes uneven requiring complex pressing tools
Solution Approach 1:
The invention resolves the thickness variation issue by transitioning from a two-dimensional surface unevenness problem to a three-dimensional solution. The lower cover layer maintains a flat two-dimensional underside surface, while the thickness variations are accommodated within the three-dimensional depth of the layer itself and the foam chamber space. This dimensional reconfiguration allows a simple flat pressing tool to be used while still achieving the required structural strength through optimized thickness distribution within the layer.
4Productivity
If foam is applied before complete assembly, then production efficiency increases, but foam may escape and deform the floor element
Solution Approach 1:
The crossbars and lower cover layer are assembled in advance to create a contained chamber structure before foam application. This preliminary assembly establishes the boundaries that will contain the foam, allowing the foam to be applied safely before complete assembly is finalized, thereby improving production efficiency while maintaining foam containment reliability.
Solution Approach 2:
The lower cover layer acts as an intermediary containment structure that is installed before foam application to prevent foam escape. This intermediate component provides the necessary boundary for foam containment during expansion, enabling early foam application without compromising reliability, while the remaining assembly steps are completed afterward.
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 design reduces tool costs, simplifies handling, and enables the production of floor elements with high productivity and a visually flawless appearance, while maintaining thermal insulation and minimizing weight, using high-strength sheet steel with anti-corrosion coatings and polyurethane foam for effective insulation.
Implementation Method 1
production proves to be more difficult if a flowable foam is to be used, which only expands after it has been applied to the upper cover layer
Implementation Method 2
To ensure sufficient thermal insulation, these chambers are usually filled with foam
Implementation Method 3
using high-strength sheet steel with anti-corrosion coatings
Data Source
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AI summary
The element (B) has an upper cover layer (1) comprising an upper surface forming a loading platform (F). A lower cover layer (10) forms an opening to a lower side (US) of a vehicle e.g. lorry. Transverse bars (7a, 7b, 8) are aligned transverse to a longitudinal direction (L) of the element. The lower layer has lower and higher thickness zones (E1, E2, E3) between which a passage is provided when thickness increase occurs in a direction of a space defined by the layers so that the lower layer runs in the longitudinal when viewing until maximum of the passage in a plane.