Small Engine Cylinder Head Combustion Chamber and Valve Angles

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Solution Overview

Problem

Small-sized general-purpose gasoline engines face challenges in meeting environmental standards without external purification means like catalytic converters, which increase costs and reduce flexibility and efficiency.

Innovation Solution

A cylinder head design with an arched smooth combustion chamber surface and strategically angled intake and exhaust valves, reducing the surface-to-volume ratio and optimizing the parameters for improved gas mixing and combustion efficiency, eliminating the need for external purifiers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a catalytic converter is used as external purification means, then the discharge standard can be met, but the cost increases and the volume and weight increase

Engineering Contradiction:

Improvedischarge emissionVSAvoidstructure complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the purification function into the combustion chamber itself by designing a spherical combustion chamber structure. The spherical shape promotes complete combustion of fuel through enhanced mixing and longer residence time of gases in the combustion chamber, thereby reducing emissions without requiring external purification devices like catalytic converters. This integration eliminates the need for separate emission control components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The combustion chamber performs self-purification through its spherical geometry which naturally promotes complete combustion. The spherical shape creates optimal flow patterns and mixing characteristics that enable the combustion process itself to minimize harmful emissions, making the system self-sufficient for emission control without external assistance.

Inventive Principle:

Principle #25Self-service

2Object-affected harmful factors

If a catalytic converter is used as external purification means, then the discharge standard can be met, but the use cost and maintenance cost increase

Engineering Contradiction:

Improvedischarge emissionVSAvoidproduction cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent combines the emission control function with the combustion chamber structure. The spherical combustion chamber design inherently promotes complete combustion through improved gas mixing and flow patterns, eliminating the need for separate catalytic converters. This reduces both production costs and maintenance costs while meeting emission standards.

Inventive Principle:

Principle #5Merging (Combining)

3Area of stationary object

If the combustion chamber surface adopts a wedge-shaped structure, then a high surface to volume ratio can be obtained, but the arrangement of valve assemblies is affected

Engineering Contradiction:

Improvecombustion chamber surface areaVSAvoidvalve assembly arrangement

Core Design Contradiction:

Area of stationary objectVSEase of operation

Solution Approach 1:

The patent employs a spherical combustion chamber structure instead of a wedge-shaped design. The spherical geometry provides optimal surface-to-volume ratio while creating symmetric flow patterns that facilitate proper valve assembly arrangement. The spherical shape ensures uniform gas distribution and mixing, enabling effective valve positioning without the geometric constraints of wedge-shaped designs.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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

The design enhances combustion efficiency, reduces fuel consumption and emissions, and meets or exceeds EPA3 standards without external purification systems, maintaining low costs and flexibility.

Implementation Method 1

Methodology Applied

Scientific EffectFluid dynamics:

Implementation Method 2

Mixture of the gasoline as fuel and air is burnt in the combustion chamber so as to generate plenty of heat energy to be as the driving energy

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS8991355B2Cylinder head of small-sized general-purpose gasoline engine and gasoline engine having the same

Publication Date: 2015.03.31 LONCIN GENERAL POWER EQUIPMENT CO LTD

AI summary

The invention discloses a cylinder head of a small-sized general-purpose gasoline engine and a gasoline engine having the same. The cylinder head of the small-sized general-purpose gasoline engine comprises a cylinder head body (1), and an intake passage (9), an exhaust passage (5) and a sparking plug mounting hole (8) arranged on the cylinder head body (1); a combustion chamber surface (7), being a arched smooth curve, is formed at the inner side of the cylinder head body (1); the cylinder head body (1) is provided with an intake valve (11) corresponding to the intake passage (9) and an exhaust valve (4) corresponding to the exhaust passage (5); the intake valve (11) is inclined towards the intake passage (9) from the bottom part to the top part; the exhaust valve (4) is inclined towards the exhaust passage (5) from the bottom part to the top part; and the included angle between the axis of the intake valve (11) and the axis of the exhaust valve (4) is 24±5 degrees. In the invention, the parameters between the combustion chamber and the intake valve as well as the exhaust valve are inter-coordinated and matched, the operation efficiency of the gasoline engine is improved, the fuel is saved, and the discharge is reduced.