Carburetor Enrichment Device with Variable Volume Feed Pump
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Solution Overview
Problem
Existing carburetors for internal combustion engines lack a simple structure that can reliably supply a defined quantity of fuel for easier engine starting, often resulting in inefficient fuel delivery and potential issues with gas bubbles in the fuel system.
Innovation Solution
A carburetor design featuring a fuel pump driven by fluctuating crankcase pressure, a manually actuable feed pump (purger) for pre-flooding and bubble removal, and an enrichment device with a variable volume enrichment chamber, where the feed pump's actuation changes the enrichment chamber volume to deliver a predefined fuel quantity, ensuring sufficient fuel supply to the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional carburetor with fuel pump and feed pump is used, then the basic fuel supply function is achieved, but the structure becomes complex and the ability to supply a defined quantity of fuel for starting is lacking
Solution Approach 1:
The patent combines the feed pump and enrichment device into a single integrated unit. The feed pump's actuation mechanism directly controls the enrichment chamber volume, merging two previously separate functions (fuel flooding and enrichment) into one coordinated system. This reduces overall device complexity while ensuring reliable defined fuel quantity supply for engine starting.
Solution Approach 2:
The feed pump serves multiple functions: it floods the fuel system with fuel before starting, removes gas bubbles from the fuel system, and simultaneously actuates the enrichment chamber to deliver a predefined quantity of fuel. This multi-functionality eliminates the need for separate enrichment mechanisms, simplifying the carburetor structure while improving reliability.
2Quantity of substance
If the feed pump is actuated to flood the fuel system, then gas bubbles are removed, but the enrichment chamber volume remains constant resulting in insufficient fuel delivery
Solution Approach 1:
The enrichment chamber is designed with variable volume that changes dynamically during feed pump actuation. As the feed pump bellows move, they directly alter the enrichment chamber volume through mechanical coupling, enabling the chamber to deliver a predefined quantity of fuel. This dynamic volume adjustment ensures sufficient fuel delivery without requiring complex separate control mechanisms.
3Manufacturing precision
If an electromagnetic valve is used to control fuel flow during starting, then the enrichment process can be automated, but the structure becomes more complex and defined fuel quantity control is difficult
Solution Approach 1:
The system uses the feed pump's own actuation mechanism to automatically control the enrichment chamber volume and fuel delivery quantity. The mechanical movement of the feed pump bellows directly translates to proportional enrichment chamber volume changes, creating a self-regulating system that delivers a predefined fuel quantity without requiring external electromagnetic valves or complex electronic control systems.
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 ensures a consistent and sufficient fuel supply to the engine, effectively aiding in easier starting and preventing gas bubbles, thereby enhancing engine reliability and performance.
Implementation Method 1
The fuel pump can advantageously be driven by the fluctuating pressure in a crankcase interior of the internal combustion engine
Implementation Method 2
The feed pump can in particular be a purger with an elastic pump bellows
Data Source
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AI summary
A carburetor for supplying a fuel/air mixture to an internal combustion engine (1) comprises a fuel pump (15), a feed pump (28) operated by an operator, and an enrichment device (29). The carburetor (9) has at least one fuel chamber (23) into which the fuel pump (15) supplies fuel. During operation, fuel is supplied from the at least one fuel chamber (23) into an intake port section (10) formed in the carburetor (9). The feed pump (28) is designed to supply fuel from the fuel chamber (23). The enrichment device (29) has an enrichment chamber (30) and is designed to supply fuel from the enrichment chamber (30) to the internal combustion engine (1).It is provided that the enrichment chamber (30) has a variable volume and that the feed pump (28) and the enrichment device (29) are coupled such that actuation of the feed pump (28) leads to a change in the volume of the enrichment chamber (30). For an internal combustion engine with a carburetor (9), it is provided that the enrichment chamber (30) is fluidically connected to a crankcase interior (8) of the internal combustion engine (1).