Commercial Vehicle Door Locking System Thermal Bridge Solution

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Solution Overview

Problem

Existing commercial vehicle door locking systems provide limited protection against burglary, can form cold bridges, and reduce insulation, while being difficult to use or offering inadequate security.

Innovation Solution

A door locking system with a joint connection between the door lock housing and the rear wall door using plastic or fiber-reinforced plastic, featuring an electric motor and locking elements housed in the door lock housing, and a latch receptacle on the rear wall frame for enhanced security and insulation preservation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a door locking system is integrated into the rear wall door, then security against break-ins is improved, but thermal insulation is reduced due to cold bridges

Engineering Contradiction:
Improvesecurity against break-insVSAvoidthermal insulation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The door lock housing is extracted from the rear wall door structure and positioned externally on the rear wall frame. This separation removes the locking mechanism from the insulated door panel, preventing it from creating cold bridges while maintaining its security function. The housing is positioned to engage with the door edge rather than being integrated into the door's insulated core.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A thermal break or insulating barrier is introduced between the door lock housing and the rear wall door. This intermediary element prevents direct thermal conduction through the locking mechanism, allowing the security function to be maintained while eliminating the harmful thermal bridge effect that would otherwise reduce the vehicle's thermal insulation performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a door locking system is integrated into the rear wall door, then security is improved, but the structure becomes more complex

Engineering Contradiction:
Improvesecurity against break-insVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The door locking system is segmented into a separate modular housing unit that can be independently positioned on the rear wall frame. This segmentation allows the locking mechanism to be designed and installed as a distinct component rather than being embedded within the complex multi-layer door structure, simplifying both the door assembly and the locking system installation.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the door lock housing is positioned on the cargo space side, then security is improved, but loading space is reduced

Engineering Contradiction:
Improvesecurity against break-insVSAvoidloading space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The door lock housing is extracted from the cargo space interior and positioned externally on the rear wall frame. This extraction eliminates the housing volume from the loading space calculation, maximizing the available cargo volume while maintaining the security function of the locking mechanism in an optimal position for engagement and resistance to forced entry.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution provides robust protection against break-ins, maintains insulation, and simplifies handling, ensuring the rear wall door can only be opened with significant damage, thus enhancing security without compromising the vehicle's structural integrity or insulation.

Implementation Method 1

a joining connection is provided between the door lock housing and the rear wall door, which has at least one joining means made of plastic or fiber-reinforced plastic extending at least substantially over the entire thickness of the rear wall door

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentEP3882420B1Utility vehicle body with door locking system
Publication Date: 2024.02.14 SCHMITZ CARGOBULL AG
  • EP3882420B1 patent drawingFigure 1
  • EP3882420B1 patent drawingFigure 2A
  • EP3882420B1 patent drawingFigure 2B

AI summary

The invention relates to a superstructure (2) of a commercial vehicle (1), in particular a truck, trailer or semi-trailer, with a rear wall frame (10) and a rear wall door (8), wherein the at least one rear wall door (8) is held in the closed position in the rear wall frame (10).In order to ensure reliable protection against break-ins of the commercial vehicle without incurring significant disadvantages compared to conventional bodies without additional door locking systems, it is provided that a door locking housing (18) is provided on the rear of the rear door (8), at least partially comprising an electric motor (19) and at least one locking element (20) adjustable by the electric motor (19) from a locking position to a release position and back, and that at least one locking receptacle (21) is provided on the rear wall frame (10) for receiving the at least one locking element (20) in the locking position.