Tailgate-Integrated CNG Tank Layout for Refuse Vehicle Packaging
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Solution Overview
Problem
Existing refuse vehicles with CNG systems face space constraints, weight distribution issues, and aesthetic concerns, as well as damage risks from excessive height and difficult tank inspection and service.
Innovation Solution
A CNG system integrated into the tailgate of a refuse vehicle, with tanks positioned between hinges and following the vehicle's contour, providing a compact, lightweight design that maintains the vehicle's height and allows for easy inspection and service, while using existing structure for mounting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the CNG system is mounted to the chassis frame, then the system has structural support, but it requires a large amount of space which limits the capacity of the refuse vehicle and adds significant weight to the front axle
Solution Approach 1:
The CNG tanks are mounted in the vertical dimension within the tailgate structure, specifically utilizing the space between the tailgate hinges and the tailgate itself. This vertical integration allows the system to occupy minimal horizontal space while maintaining structural support through the existing tailgate framework.
Solution Approach 2:
The CNG tanks are nested within the existing tailgate structure, utilizing the space between the hinges and the tailgate panel. This nesting approach allows the CNG system to be housed within the existing vehicle structure without requiring additional external space or significantly increasing overall vehicle dimensions.
2Strength
If the CNG system is mounted to the chassis frame, then the system has structural support, but a large percentage of weight is added to the chassis front axle
Solution Approach 1:
By relocating the CNG system from the front chassis area to the rear tailgate area, the weight distribution is fundamentally changed. The tanks are positioned in the vertical space within the tailgate, moving the weight burden from the front axle to the rear axle and tailgate structure.
Solution Approach 2:
The invention utilizes the existing tailgate structure as a mounting framework, copying the structural support function from the chassis to the tailgate assembly. This allows the CNG system to be supported by the tailgate hinges and framework rather than adding weight to the front chassis.
3Ease of operation
If the CNG system is roof mounted, then the system is easily accessible, but it exposes the CNG unit to damage by low bridge overpasses, shop doors, tree limbs, etc. and adds significant weight to the front axle
Solution Approach 1:
The CNG tanks are positioned in the vertical dimension within the tailgate structure, between the hinges and the tailgate panel. This placement keeps the system below the vehicle's overall height profile, eliminating exposure to overhead obstacles while maintaining accessibility from the rear of the vehicle.
Solution Approach 2:
The invention copies the protective function of the vehicle body by integrating the CNG tanks within the tailgate structure itself. The tailgate panel and frame serve as protective enclosures, shielding the tanks from external damage while keeping the system accessible from the rear.
4Adaptability or versatility
If preassembled PODs are installed on the tailgate, then the CNG system is integrated, but the units are relatively large providing an overhang with the center of gravity measured from the tailgate hinge, creating a large moment on the tailgate raised cylinder and structure
Solution Approach 1:
The CNG tanks are positioned locally within the tailgate structure, specifically between the hinges and the tailgate panel. This localized placement concentrates the mass close to the hinge axis, minimizing the moment arm and reducing the rotational moment applied to the tailgate cylinder and structure.
Solution Approach 2:
The tanks are nested within the tailgate structure rather than mounted as external overhanging units. This nesting positions the CNG system within the existing structural envelope, eliminating the overhang and associated moment forces while maintaining integration with the tailgate assembly.
5Adaptability or versatility
If preassembled PODs are installed on the tailgate, then the CNG system is integrated, but the CNG fuel line routing is exposed due to the routing over the tailgate top cross member
Solution Approach 1:
The fuel line routing is nested within the tailgate structure, with lines routed through the internal framework and panels rather than externally along the top cross member. This internal routing conceals the fuel lines within the structured envelope of the tailgate, eliminating aesthetic concerns while maintaining functional integration.
6Volume of moving object
If tanks in the POD tailgate are stacked, then the CNG system is compact, but inspection and service of the tanks becomes difficult
Solution Approach 1:
The CNG system is segmented into multiple individual tanks rather than a single large stacked unit. This segmentation allows each tank to be independently accessed, inspected, and serviced. The tanks are arranged within the tailgate structure in a configuration that provides access pathways for maintenance personnel.
Solution Approach 2:
The invention copies the serviceability of external tank mounting by providing access pathways within the tailgate structure. The internal arrangement of tanks within the tailgate envelope maintains ease of access similar to external mounting, allowing inspection and service without requiring disassembly of the entire tailgate assembly.
7Adaptability or versatility
If preassembled POD assembly is used, then the CNG system is integrated, but the assembly is quite heavy adding additional weight to the refuse vehicle reducing its capacity
Solution Approach 1:
The tailgate structure serves multiple functions: it provides the vehicle's rear closure, structural support, and CNG system mounting framework. By making the tailgate multi-functional, the invention eliminates the need for separate POD assemblies, reducing overall weight while maintaining integration of the CNG system with the vehicle structure.
Data Source
AI summary
A refuse vehicle has a tailgate. The tailgate has a framework to secure CNG tanks. A cover overlays the frame work to provide an aesthetic appearance to the vehicle.