Radial Lost Motion Mechanism Attachment for Engine Miniaturization

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Solution Overview

Problem

Conventional lost motion mechanisms require increased thickness of engine components for attachment, leading to bulkiness and potential issues with clearance that can affect reliability.

Innovation Solution

A lost motion mechanism with a regulator, support, and attaching portion that includes a protrusion or recess for attachment to engine components without increasing thickness, featuring a through-hole for air and oil escape and a cylindrical cover for protection and bending limitation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lost motion spring is buried deeply into the cylinder head for attachment, then the attachment is secured, but the cylinder head thickness must be increased

Engineering Contradiction:

Improveattachment reliabilityVSAvoidcylinder head thickness

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The attaching portion is designed to extend in the radial direction of the lost motion spring rather than the axial direction, changing the attachment dimension from axial to radial. This allows the lost motion mechanism to be attached to the cylinder head without increasing its thickness, as the attachment occurs in a different spatial dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The attaching portion with protrusion or recess is integrated into the support structure, nesting the attachment feature within the existing radial extension of the support. This eliminates the need for separate attachment components that would increase axial thickness.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Strength

If the lost motion mechanism is attached to the engine with increased thickness, then the attachment is more secure, but the engine components become bulkier

Engineering Contradiction:

Improveattachment strengthVSAvoidengine component volume

Core Design Contradiction:

StrengthVSVolume of stationary object

Solution Approach 1:

The attaching portion is designed with localized protrusions or recesses that concentrate the attachment function in a specific radial region of the support. This localizes the structural modification needed for attachment, avoiding the need to increase the overall volume of the engine component while maintaining sufficient attachment strength at the critical interface.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If the attaching portion projects out of the support in the axial direction, then the attachment is easier, but the thickness of the engine portion must be increased

Engineering Contradiction:

Improveattachment easeVSAvoidengine portion thickness

Core Design Contradiction:

Ease of manufactureVSLength of stationary object

Solution Approach 1:

The attachment interface is oriented radially rather than axially, allowing the protrusion or recess to be formed on the radial surface of the support. This dimensional change enables easy attachment through radial alignment features while maintaining compact axial thickness.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3842623B1Lost motion mechanism, valve gear and engine

Publication Date: 2023.02.08 YAMAHA MOTOR CO LTD

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AI summary

A valve gear includes a lost motion mechanism including a lost motion spring. A pillar is inserted into the lost motion spring, and a seat supports a lower end portion of the lost motion spring. A protrusion is provided on an opposite side of the seat from the lost motion spring. When viewed from an axial direction of the lost motion mechanism, the protrusion does not project out of the seat. By fitting the protrusion into the recess of the cylinder head, the seat, i.e., the lost motion mechanism is attached to the cylinder head.