Power Cord Thermal Sensor Protrusion for Accurate Blade Temperature Detection

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Solution Overview

Problem

Conventional power cords with thermal sensors fail to accurately detect the temperature between blades due to the sensor not being in contact with the enclosure, leading to potential safety impairments.

Innovation Solution

A power cord design where the thermal sensor protrudes from the core to be in contact with the enclosure, allowing for accurate temperature detection between the blades and enabling timely interruption of electric power in case of abnormal temperature rises.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the thermal sensor is retained in a recess of the core with spacing, then the sensor is protected and easily manufactured, but the temperature detection accuracy deteriorates

Engineering Contradiction:
Improvetemperature detection accuracyVSAvoidsensor retention structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The thermal sensor is extracted from the recess of the core and positioned to protrude toward the enclosure. This extraction allows the sensor to be closer to the blades without the constraint of being confined in a recess, thereby improving temperature detection accuracy while maintaining a relatively simple retention structure through the use of a sensor holding portion that extends from the core.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If the thermal sensor is in contact with the enclosure, then temperature detection accuracy improves, but the sensor may be affected by external heat sources

Engineering Contradiction:
Improvetemperature detection accuracyVSAvoidexternal heat interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The enclosure is provided with a localized sensor receiving portion that is specifically designed to receive the thermal sensor. This localized structure allows the sensor to be positioned close to the blades for accurate temperature detection while the rest of the enclosure maintains its protective function. The sensor receiving portion acts as a dedicated interface that minimizes external heat interference while enabling accurate local temperature measurement.

Inventive Principle:
Principle #3Local quality

3Reliability

If the thermal sensor protrudes from the core to contact the enclosure, then temperature detection reliability improves, but the manufacturing complexity increases

Engineering Contradiction:
Improvetemperature detection reliabilityVSAvoidplug assembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sensor holding portion is merged with the core structure, forming an integrated component. This integration allows the thermal sensor to protrude from the core in a controlled manner while maintaining structural integrity. The merging of the sensor holding portion with the core simplifies the overall manufacturing process compared to using separate retention mechanisms, as it can be formed as a single molded piece or integrated during the core assembly process.

Inventive Principle:
Principle #5Merging (Combining)

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 design enhances safety by ensuring reliable detection of temperature anomalies between the blades, allowing for immediate power cutoff and preventing overheating hazards.

Implementation Method 1

A part of the thermal sensor protrudes from the core to be in contact with the enclosure... configured to detect a temperature of a region between the male connectors (blades)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2706627B1Power cord
Publication Date: 2017.10.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2706627B1 patent drawingFigure 1
  • EP2706627B1 patent drawingFigure 2~3
  • EP2706627B1 patent drawingFigure 4

AI summary

A power cord (100) includes a plug (1) having blades (11) and a thermal sensor (5) configured to detect a temperature, and a cut-off means (3) configured to stop electric power from being supplied to the load connection portion from the blades (11) when a temperature detected with the thermal sensor (5) is higher than a prescribed temperature. The plug (1) includes a core (6) which retains the blades (11) and the thermal sensor (5), and an enclosure (7) which is formed by molding synthetic resin to cover an outside of the core (6). A part of the thermal sensor (5) protrudes from the core (6) to be buried in the enclosure (7).