Photovoltaic Junction Box Strain Relief Connector Design

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Solution Overview

Problem

Existing photovoltaic panel boxes face challenges with connection options to the outside environment, heat balance, internal contacting, and structural design, particularly with simple connection plugs that are not suitable for practical use.

Innovation Solution

The solution involves a strain relief mechanism with a sleeve and clamping element that secures the connection line, additional connection plugs for cable management and testing, and latching means for easy assembly and audible feedback, along with a test opening for external electrical functionality verification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If simple connectors are used for connecting cables, then the device complexity is reduced, but the reliability of connections deteriorates under harsh real-world conditions

Engineering Contradiction:
Improveconnector designVSAvoidconnection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The connector is divided into separate functional components: a connector housing, a clamping element for cable securing, and a sealing element for environmental protection. This segmentation allows each component to be optimized independently while maintaining overall simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clamping element and sealing element are nested within the connector housing, with the sealing element positioned between the housing and the cable assembly. This nested arrangement provides reliable connection and sealing functions without adding external complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If additional components like strain relief and sealing elements are added to connectors, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The clamping element and sealing element are integrated into a single connector assembly that attaches to the housing in one operation. This merging of functions reduces the number of separate assembly steps and maintains practical simplicity despite enhanced reliability features

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If cable tails are supplied with attached connectors, then the ease of operation is improved, but the reliability deteriorates due to free movement and tangling risks

Engineering Contradiction:
Improvecable connectionVSAvoidcable stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The connector is pre-assembled with the cable tail during manufacturing, but the cable is routed through a guiding structure in the housing that prevents free movement and tangling. This preliminary action with preventive guidance maintains ease of connection while ensuring cable stability

Inventive Principle:
Principle #10Preliminary action

4Reliability

If locking means are added to fix component positions, then the reliability is improved, but the ease of operation deteriorates due to additional assembly steps

Engineering Contradiction:
Improvecomponent positioningVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The connector components feature self-aligning and self-latching mechanisms that automatically secure components in their correct positions during assembly. The housing structure guides the connector into proper alignment, and the clamping element automatically engages with the cable, eliminating the need for additional manual positioning or fastening steps

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2718985B1Photovoltaic junction box with improved external connectors
Publication Date: 2020.03.25 HIRSCHMANN AUTOMOTIVE GMBH
  • EP2718985B1 patent drawingFigure 1
  • EP2718985B1 patent drawingFigure 2
  • EP2718985B1 patent drawingFigure 3

AI summary

The invention relates to a photovoltaic junction box comprising a lower housing part (1) and an upper housing part (2) that cooperates with the lower housing part (1). A seal (3) is provided between the lower housing part (1) and the upper housing part (2), in addition to at least one connecting plug (4) for a connecting cable (5), and the interior of the photovoltaic junction box contains a contact support (6) comprising contacts. The junction box is characterised in that the connecting cable (5) is connected to the connecting plug (4) by means of a strain relief clamp, said strain relief clamp having at least one sleeve (400) that is displaceable over the connecting cable (5), and a clamping element (401) that combines with said sleeve and exerts a radial force upon the connecting cable (5).