Engine Stop Switch Placement Near Cooling Passage for Heat Protection

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Solution Overview

Problem

Existing engine designs face issues with the placement of emergency stop switches, which can compromise operability and are prone to damage from high temperatures, especially when placed in areas prone to heat, and can be difficult to access due to limited space in engine compartments.

Innovation Solution

The emergency stop switch is positioned at the cooling part or its peripheral part, such as the cooling water tank, away from hot exhaust outlets and turbochargers, allowing easy access and reducing the risk of heat damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the emergency stop switch is placed in a space portion formed at the top cover, then the switch is protected from accidental stepping, but the operability may be poor and the switch may be exposed to high temperatures

Engineering Contradiction:
Improveprotection from accidental steppingVSAvoidoperability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent transitions from vertical placement (top cover) to horizontal placement along the crankshaft direction. The emergency stop switch is positioned at the peripheral part of the cooling liquid passage, specifically at the end opposite to the exhaust outlet pipe, utilizing the lateral dimension of the engine structure rather than the vertical dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The cooling liquid passage serves as an intermediary structure that provides both thermal protection and operational accessibility. By placing the switch at the peripheral part of this passage, the design leverages the cooling liquid's temperature-regulating function to protect the switch while maintaining easy access.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the emergency stop switch is placed near the exhaust outlet pipe, then the switch is easily accessible, but the switch is exposed to high temperatures causing deterioration

Engineering Contradiction:
ImproveaccessibilityVSAvoidheat exposure
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The patent employs asymmetric placement within the cooling liquid passage structure. Instead of placing the switch at the exhaust side (hot end), it is positioned at the opposite end of the passage, creating an asymmetric thermal environment where one end is hot and the other is cool, with the switch located at the cool end.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the engine are assigned different thermal characteristics. The exhaust outlet pipe region maintains high temperature for combustion efficiency, while the peripheral part of the cooling liquid passage is maintained at low temperature, and the emergency stop switch is specifically located in this low-temperature zone.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the emergency stop switch is placed in a confined engine compartment, then the engine structure is compact, but the switch becomes difficult to access

Engineering Contradiction:
Improveengine compartment sizeVSAvoidaccessibility
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The peripheral part of the cooling liquid passage serves multiple functions: it provides structural support for the engine, acts as a thermal management pathway, and simultaneously serves as an optimal mounting location for the emergency stop switch. This multi-functional use of space achieves compactness without compromising accessibility.

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 placement improves the operability and durability of the emergency stop switch by keeping it cool and accessible, ensuring easy operation even in confined spaces.

Implementation Method 1

a cooling part included in a holding portion or passage of a cooling liquid

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 2

passage of a cooling liquid

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4242449B1engine
Publication Date: 2025.12.17 YANMAR HLDG CO LTD
  • EP4242449B1 patent drawingFigure 1
  • EP4242449B1 patent drawingFigure 2
  • EP4242449B1 patent drawingFigure 3

AI summary

To improve an engine provided with an engine stop switch. [Solution] An exemplary engine includes: an engine stop switch for stopping the engine; and a cooling part included in a holding portion or passage of a cooling liquid, wherein the engine stop switch is placed at the cooling part or at a peripheral part of the cooling part.