Hermetic Heat-Generating Element With Test Channel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat-generating elements for motor vehicle electrical heating devices face challenges in maintaining hermetic sealing and ensuring reliable operation with high currents, particularly in preventing moisture and dirt ingress while allowing for quality control and leak testing.
Innovation Solution
A heat-generating element with a hermetically sealed receptacle accessible via an externally accessible test channel, featuring a connecting piece surrounded by a sealing element for leak testing and sealed installation, and a connection housing with a receptacle for the connecting piece to ensure sealed operation and quality control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the receptacle is hermetically sealed to protect PTC elements from moisture and dirt, then reliability is improved, but accessibility for quality control and leak testing deteriorates
Solution Approach 1:
The sealing system is segmented into the hermetically sealed receptacle and a separate test channel with connecting piece. The test channel provides controlled access for leak testing and quality control without compromising the hermetic seal of the main receptacle containing the PTC elements.
Solution Approach 2:
The test channel acts as an intermediary element between the external testing equipment and the hermetically sealed receptacle. It allows introduction of test media (gas or liquid) to verify sealing integrity without creating permanent openings that would compromise reliability.
2Ease of operation
If the test channel is made externally accessible for leak testing, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The connecting piece with sealing element serves multiple functions: it provides external access for leak testing, ensures hermetic sealing during testing, and maintains the integrity of the receptacle structure. This multi-functionality reduces the need for separate testing fixtures or disassembly procedures.
3Reliability
If the connecting piece is surrounded by a sealing element for hermetic installation, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The sealing element acts as a flexible barrier that compensates for minor dimensional variations and assembly tolerances. This flexible sealing approach achieves hermetic installation without requiring extremely tight manufacturing precision, as the sealing element can deform to accommodate small deviations.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a heat-generating element (6), particularly for an electric heating device of a motor vehicle, comprising a positioning frame (76) forming a receptacle (78) in which at least one PTC element (80) is received, and contact plates (82) bearing against two opposite sides of the PTC element (80). Furthermore, the present invention relates to an electric heating device, particularly for a motor vehicle, comprising a frame in which a layered structure with corrugated fin elements (64) and heat-generating elements (66) of the type mentioned above is received. With a view to increased electrical safety, the heat-generating element (66) is further developed according to the invention by sealing the receptacle (78) and making it accessible via at least one externally accessible test channel (116).The electric heating device has a nozzle receptacle (132) adapted for the sealing reception of a connecting nozzle (92) projecting from the heat-generating element (66). The present invention further relates to a method for manufacturing an electric heating device in which the tightness of the heat-generating elements is checked.