Charging Connector Cover Layout to Prevent Unauthorized Unplugging

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Solution Overview

Problem

There is a risk that a charging cable for a battery unit in an electric hydraulic excavator can be unplugged by a third party without the knowledge of the operator during charging.

Innovation Solution

A working machine with a cover that has a cutout part, allowing the charging connector to be exposed while covering the switch in a lockably closed state, reducing the risk of unauthorized unplugging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the opening and closing part is located at the open position during charging to allow cable connection, then the charging operation is convenient, but the risk that a cable may be unplugged by a third party increases

Engineering Contradiction:
Improvecharging operation convenienceVSAvoidcable connection security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cover is divided into two functional zones: a cutout part that exposes only the charging connector for cable connection, and a locked area that covers the opening and closing part. This segmentation allows the charging port to be accessible while the control switch remains protected, resolving the contradiction between operational convenience and security.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cover acts as an intermediary element that mediates between the charging connector and the opening and closing part. By allowing the cable to pass through the cutout part while blocking access to the switch, the cover enables charging operations while preventing unauthorized unplugging, thus resolving the security-convenience contradiction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the charging connector is exposed to allow cable connection, then the charging process is accessible, but the switch becomes vulnerable to unauthorized operation

Engineering Contradiction:
Improvecharging accessibilityVSAvoidunauthorized switch operation
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cover design segments the accessible area (cutout part exposing the charging connector) from the protected area (locked area covering the opening and closing part). This allows the charging connector to be accessible for cable connection while the switch remains hidden and protected from unauthorized operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cover provides different levels of access to different components: the charging connector area is locally exposed through the cutout part for operational accessibility, while the opening and closing part area is locally covered and locked for protection. This local differentiation resolves the contradiction between accessibility and protection.

Inventive Principle:
Principle #3Local quality

3Reliability

If the cover is fully closed to protect internal components, then security is improved, but the charging connector becomes inaccessible

Engineering Contradiction:
Improvecomponent protectionVSAvoidcharging connector accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The charging connector is extracted from the fully enclosed cover space and exposed through the cutout part. This allows the charging connector to remain accessible for cable connection while the rest of the internal components remain protected by the closed cover, resolving the contradiction between protection and accessibility.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of making the entire cover open for charging access, the design inverts the approach by keeping the cover closed and creating a specific opening (cutout part) for the charging connector. This inverted approach maintains overall security while providing targeted accessibility, resolving the contradiction between protection and access.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP4624675A1Working machine
Publication Date: 2025.10.01 YANMAR HLDG CO LTD
  • EP4624675A1 patent drawingFigure 1
  • EP4624675A1 patent drawingFigure 2
  • EP4624675A1 patent drawingFigure 3

AI summary

[Problem] To reduce a risk that a cable is unplugged by a third party without the knowledge of a worker while a battery unit is being charged. [Solution] A working machine uses electric power of a battery unit as a driving source. The working machine includes: a charging connector to which a cable for charging the battery unit is to be connected; a switch for releasing lock applied when the charging connector is connected to the cable; a machine room that houses the battery unit, the charging connector, and the switch; and a cover that has a cutout part, and is openable and closable with respect to the machine room. The cover exposes the charging connector to outside through the cutout part while covering the switch in a lockably closed state.