Internal Combustion Engine Crankshaft Detection Positioning

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Solution Overview

Problem

The challenge is to enhance the detection accuracy of a detection sensor in an internal combustion engine while minimizing crankshaft deflection, which affects the sensor's positioning and functionality.

Innovation Solution

The internal combustion engine structure incorporates a detection device positioned near an orthogonal virtual line passing through the crankshaft's center, orthogonal to the cylinder's center axis, and includes a balancer shaft to suppress vibration, allowing the detection device to be placed between the balancer shaft and the starting device, thereby reducing deflection and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the detection device is disposed at a suitable position for accurate detection, then detection accuracy is improved, but crankshaft deflection increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidcrankshaft deflection
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent positions the detection device in a specific spatial dimension (above the crankshaft center in the vertical direction, within a defined angular range) to achieve accurate detection while avoiding the harmful radial position that would cause crankshaft deflection. This dimensional repositioning resolves the contradiction between detection accuracy and crankshaft stability.

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

Solution Approach 2:

The patent introduces an intermediary positioning approach by defining a specific spatial zone (range A1) between the crankshaft center and the cylinder center axis. This intermediary zone allows the detection device to be positioned optimally for detection while maintaining sufficient distance from the crankshaft to avoid causing deflection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the detection device is positioned closer to the crankshaft center for better detection, then detection accuracy improves, but the risk of causing crankshaft deflection increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidcrankshaft deflection risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating a specific spatial zone (range A1) with distinct characteristics: close enough to the crankshaft center for accurate detection, but positioned in a localized area above the center where the harmful effect of deflection is minimized. This localized positioning achieves detection accuracy while avoiding the harmful radial proximity.

Inventive Principle:
Principle #3Local quality

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 configuration effectively suppresses crankshaft deflection, allowing for improved detection accuracy and efficient use of space, while also providing protection and reducing component count through integrated support members.

Implementation Method 1

a balancer shaft that suppresses vibration of the crankshaft

Methodology Applied
Scientific EffectVibration suppression: Damping

Data Source

PatentEP3992441B1Internal combustion engine structure
Publication Date: 2024.05.08 HONDA MOTOR CO LTD
  • EP3992441B1 patent drawingFigure 1
  • EP3992441B1 patent drawingFigure 2
  • EP3992441B1 patent drawingFigure 3

AI summary

An internal combustion engine structure includes: a crankshaft (10) that converts reciprocating motion of a piston (24) disposed inside a cylinder (12) of an internal combustion engine (2) to be mounted on a vehicle into rotational motion; a case member (11) that houses the crankshaft (10); a balancer shaft (14) that suppresses vibration of the crankshaft (10); a starting device (15) that starts the internal combustion engine (2); and a detection device (16) that is disposed between the balancer shaft (14) and the starting device (15) in a side view and determines the rotation speed of the crankshaft (10).