Thermoformed Tailgate Load-Bearing Structures for Dimensional Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing manufacturing processes for load-bearing structures in automobile doors and tailgates face high costs and limitations in dimension due to the use of steel, aluminum, and injection molding, which are not cost-effective for large parts and require assembly of multiple pieces.
Innovation Solution
A thermoforming process using thermoplastic materials with structural fibers, allowing large-scale production of load-bearing structures with integrated internal metallic substructures and surplus material utilization for auxiliary parts, and a method involving variable mold distances and pressures to achieve dimensional stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If injection molding is used to manufacture large load-bearing structures, then manufacturing precision and strength are improved, but device complexity and cost increase due to limitations in injector size and the need to divide into multiple pieces
Solution Approach 1:
The patent replaces the injection molding process with a thermoforming process. Instead of injecting material under high pressure into complex molds, the process involves heating a thermoplastic sheet and forming it over a mold using vacuum or pressure. This substitution eliminates the limitations of injector size and reduces the complexity of manufacturing large structures, as the entire sheet can be formed in one operation without dividing into multiple pieces.
Solution Approach 2:
The patent changes the manufacturing parameters from injection molding (high pressure, high temperature, complex mold cycles) to thermoforming (controlled heating, vacuum or pressure forming). By controlling the temperature and pressure parameters during the forming process, the patent achieves the necessary structural strength while simplifying the manufacturing process and reducing device complexity.
2Strength
If injection molding is used for large load-bearing structures, then strength is improved, but manufacturing cost increases due to high costs of thermosetting technologies and injection of large parts
Solution Approach 1:
The patent replaces expensive injection molding processes with a more cost-effective thermoforming process. Thermoforming uses simpler equipment (heating chambers, vacuum formers) compared to expensive injection molding machines, particularly for large parts. This substitution significantly reduces manufacturing costs while maintaining structural strength through proper mold design and material selection.
Solution Approach 2:
The patent changes the manufacturing approach from injection molding to thermoforming, which involves different temperature and pressure parameter control. This parameter change enables the use of more economical materials and equipment, reducing manufacturing costs while achieving the required structural performance through optimized forming conditions.
3Ease of manufacture
If thermoforming of thermoplastics is used for large parts, then manufacturing cost and complexity are reduced, but manufacturing precision and dimensional stability are worsened
Solution Approach 1:
The patent applies preliminary action by pre-heating the thermoplastic sheet to a controlled temperature range before forming. This preliminary heating step ensures the material is at the optimal temperature for forming, which prevents dimensional instability during the forming process. The pre-heating stage is critical for achieving both manufacturing simplicity and dimensional precision in large thermoformed parts.
Solution Approach 2:
The patent carefully controls the temperature and pressure parameters during the thermoforming process to achieve dimensional stability. By maintaining specific temperature ranges and pressure levels, the patent prevents excessive deformation or warping of large parts. This parameter control enables the process to deliver both simplicity and precision, overcoming the traditional trade-off.
4Weight of moving object
If thermoplastic material is used instead of steel or aluminum, then weight is reduced, but strength and rigidity are worsened
Solution Approach 1:
The patent employs composite materials by combining thermoplastic material with reinforcement elements such as glass fibers, carbon fibers, or metal stiffening ribs. This composite approach allows the structure to achieve the necessary strength and rigidity while maintaining the weight advantage of thermoplastics. The reinforcement elements are integrated during the forming process, creating a lightweight yet strong composite structure that outperforms solid metal alternatives in weight-to-strength ratio.
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
Enables cost-effective, large-scale production of load-bearing structures with reduced complexity and cost, incorporating auxiliary elements and integrated substructures, while eliminating the need for supplementary upholstery.
Implementation Method 1
heating a sheet of thermoplastic material with dimensions equivalent to the load-bearing structure for tailgates of vehicles to a temperature between 200-400° C.
Implementation Method 2
cooling down the male mold and the female mold between 30-50° C.
Implementation Method 3
actuating the male mold and the female mold causing the pressing of the sheet of thermoplastic material at a temperature between 180° C. to 210° C. to obtain the load-bearing structure
Data Source
AI summary
Process for manufacturing a load-bearing structure for tailgates of vehicles by thermoforming, the process comprises obtaining a thermoforming press comprising a male mold and a female mold, wherein the male mold and the female mold comprise variable maximum distances between the male mold and the female mold, heat a sheet of thermoplastic material with dimensions equivalent to the load-bearing structure for tailgates of vehicles, cooling down the male mold and the female mold, placing the sheet of thermoplastic material between the male mold and the female mold, adjusting the male mold and the mold female causing the pressing of the sheet of thermoplastic material to obtain the load-bearing structure and dimensionally stabilize the load-bearing structure.