Composite Plastic Hood for Vehicle Rooftop AC Unit

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Solution Overview

Problem

Rooftop air conditioning systems for road vehicles have a complex structure, making them expensive to produce and install.

Innovation Solution

A hood for the rooftop air conditioner is designed as a plastic composite component with a weather-resistant outer skin and a less expensive inner skin, where the inner skin is injection molded onto the outer skin, allowing for cost-effective series production and integration of key components like the evaporator and condenser units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a weather-resistant plastic is used for the entire hood, then weather resistance is improved, but production cost increases

Engineering Contradiction:
Improveweather resistanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The hood is divided into two functional layers: an outer skin made of weather-resistant plastic for protection, and an inner skin made of less expensive plastic for structural support. This segmentation allows each layer to perform its specific function optimally while reducing overall material costs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a composite structure by combining two different plastics with distinct properties. The outer skin uses weather-resistant material for durability, while the inner skin uses cost-effective material for structural integrity, achieving both weather resistance and cost efficiency through material composition.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If key components are pre-assembled into the hood, then installation effort is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improveinstallation effortVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent integrates key components such as the evaporator unit, condenser unit, and air filter directly into the hood structure during manufacturing. This merging of components reduces the number of separate assembly steps during installation, simplifying the installation process while the integrated design streamlines the manufacturing process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Essential components are pre-assembled into the hood during the manufacturing process rather than during vehicle installation. This preliminary action of assembling components before final installation reduces on-site installation effort and time, while the standardized pre-assembly process manages manufacturing complexity.

Inventive Principle:
Principle #10Preliminary action

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 production costs and simplifies installation by enabling pre-assembly of essential components, making the rooftop air conditioning system more affordable and easier to install on vehicles.

Implementation Method 1

the inner skin is injection molded onto the outer skin

Methodology Applied
Scientific EffectInjection molding:

Data Source

PatentEP3109078B1Hood of a roof-top air-conditioning system for a road vehicle
Publication Date: 2019.09.25 MAHLE INT GMBH
  • EP3109078B1 patent drawingFigure 1~2
  • EP3109078B1 patent drawingFigure 3
  • EP3109078B1 patent drawingFigure 4

AI summary

The present invention relates to a hood (12) for a roof-mounted air conditioning unit (1) of a road vehicle. Cost-effective manufacturing of the hood (12) can be achieved with an outer skin (32) made of a first plastic, located on an outer surface of the hood (12), and with an inner skin (33) located on an inner surface of the hood (12), which is injection-molded onto the outer skin (32) and which consists of a second plastic that differs from the first plastic of the outer skin (32).