PTC heating device and method for producing same

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Solution Overview

Problem

PTC heating devices face challenges in effectively compensating for dimensional tolerances and ensuring reliable electrical and thermal contact between the PTC element and conductor elements, particularly in high-voltage applications, where direct electrical contact and efficient heat transfer are critical.

Innovation Solution

The PTC heating device employs ultrasonically welded frame segments that enclose the PTC element, with connecting segments designed to adjust for height tolerances and ensure electrical conductivity and heat transfer, using a plastic frame and sheet metal conductor elements that protrude beyond the frame for comprehensive coverage and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If frame segments are used to enclose the PTC element, then dimensional tolerances can be compensated, but the device complexity increases due to assembly requirements

Engineering Contradiction:
Improvedimensional tolerance compensationVSAvoidframe assembly complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The frame is divided into multiple frame segments that can be assembled around the PTC element. Each frame segment independently compensates for dimensional tolerances in specific areas, allowing the overall structure to accommodate variations in PTC element dimensions without requiring precise manufacturing of the entire frame as a single piece.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The frame segments are designed with movable or adjustable connections that allow dynamic adaptation to the actual dimensions of the PTC element. This enables the frame structure to self-adjust and compensate for tolerance variations through mechanical flexibility rather than rigid fixed dimensions.

Inventive Principle:
Principle #15Dynamics

2Reliability

If conductor elements are made to protrude beyond the frame, then electrical and thermal contact is improved, but the risk of incorrect assembly increases

Engineering Contradiction:
Improveelectrical and thermal contact reliabilityVSAvoidassembly error risk
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The conductor elements are pre-positioned and fixed to the frame segments during frame assembly, before the PTC element is installed. This preliminary positioning ensures that the conductor elements are already correctly oriented and spaced, reducing the risk of misalignment during final assembly and ensuring reliable contact surfaces are ready for the PTC element.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Identical frame segments with identical conductor element configurations are used on opposite sides of the PTC element. This symmetry creates a standardized, repeatable assembly pattern that reduces assembly errors through consistency and makes it easier to verify correct assembly through visual inspection.

Inventive Principle:
Principle #26Copying

3Ease of manufacture

If identical frame segments are used, then production is simplified, but the ability to handle asymmetric tolerance variations is reduced

Engineering Contradiction:
Improveproduction simplicityVSAvoidasymmetric tolerance handling
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The identical frame segments are designed with universal features that allow them to function in multiple positions and orientations. Each segment contains all necessary conductor elements and structural features to handle any tolerance variation scenario, making the segments interchangeable and adaptable to asymmetric conditions while maintaining production simplicity through standardization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution effectively compensates for height tolerances, ensures reliable electrical and thermal contact, and simplifies production by using identical frame segments and conductor elements, reducing the risk of incorrect assembly and enhancing the device's structural integrity and performance.

Implementation Method 1

The frame segments 4.1 and 4.2 are welded to one another, in particular ultrasonically welded

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Implementation Method 2

The heat generated by the PTC element is conducted directly through the conductor element to the outer side of the PTC heating device by thermal conduction

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

The heat generated by the PTC element is conducted directly through the conductor element to the outer side of the PTC heating device by thermal conduction

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4362606A1PTC heating device and method for producing same
Publication Date: 2024.05.01 EBERSPACHER CATEM GMBH & CO KG
  • EP4362606A1 patent drawingFigure 1
  • EP4362606A1 patent drawingFigure 2~3
  • EP4362606A1 patent drawingFigure 4~6b

AI summary

The present invention relates to a PTC heating device (2) with a frame (4) surrounding a receiving chamber (6), at least one PTC element (8) received in the receiving chamber (6), and conductor elements (14) electrically connected to the PTC element (8) and enclosing the PTC element (8) between them, each conductor element (14) being circumferentially surrounded by a frame segment (4.1; 4.2). For reliable connection of the frame segments (4.1; 4.2), they are welded together to enclose the PTC element (8) in the receiving chamber (6). In the method according to the invention, frame segments (4.1; 4.2) are injection molded from a plastic. Interacting connecting segments (40; 42) are formed on the frame segments (4.1; 4.2). Each of the frame segments (4.1; 4.2) is also connected to a conductor element (14). Then, at least one PTC element (8) is inserted between the frame segments (4.1; 4.2). The frame segments (4.1; 4.2) are brought close together until the connecting segments (40; 42) are in contact with each other. The connecting segments (40; 42) are then melted. During this process, the frame segments (4.1; 4.2) are brought further close together until the conductor elements (14) are in contact with the PTC element (8).