Method and apparatus for holding a cylinder valve closed during combustion

Abstract

An outwardly opening valve system for an engine includes an engine having a hollow piston cylinder in fluid communication with a gas passageway via an opening. The engine also has a piston bore that opens to the hollow piston cylinder. A portion of the opening includes an outward valve seat positioned adjacent the gas passageway. An outward valve member with a valve face is positioned substantially in the gas passageway. The valve member is moveable between a closed position in which the valve face is against the valve seat closing the opening and an open position in which the valve face is away from the valve seat. An intensifier piston is positioned to reciprocate in the piston bore and has one end contacting gas within the hollow piston cylinder. Finally, a coupling linkage interconnects the intensifier piston to the outward valve member so that the valve member is held closed during combustion by exploiting combustion pressure within the hollow piston cylinder.

Description

TECHNICAL FIELDThe present invention relates generally to outward opening valves for internal combustion engines, and more particularly to a method and apparatus for holding outwardly opening cylinder valves for an engine closed during combustion.BACKGROUND ARTIn the past, almost all engines utilized inwardly opening valves to permit the exchange of gases with the engine's hollow piston cylinders between each combustion event. The valve member typically includes an enlarged portion with an annular valve face that is positioned within the hollow piston cylinder and a stem attached to the enlarged portion that protrudes away through the opening connecting the cylinder to a gas passageway. During combustion, these valve members are held against their seats by the high pressure differential existing across the valve opening during combustion. In most cases, these types of valves are pushed open between combustion events by a cam that is driven directly by the engine. While these types o...

AI Technical Summary

Benefits of technology

In the method of the present invention, the intensifier piston is coupled to the outward valve member such that a force on the intensifier piston from combustion pressure within the hollow piston cylinder is transformed into a force on the outward valve member that is opposite in direction and greater in magnitude to a force on the outward valve member from the combustion pressure within the hollow piston cylinder. In other words, the coupling of the intensifier piston to the outward valve member allows the combustion pressure within the hollow piston cylinder to be exploited to hold the valve member closed during combustion to obtain the same advantage as the inwardly opening valve members of the prior art but without the risk of valve to piston contact that exists in prior art systems.

One object of the present invention is to eliminate the possibility of valve to piston contact during the operation of an engine.

Problems solved by technology

While these types of cam driven inwardly opening valves have performed well over many years, the current trend toward electronically controlled valves may render the inwardly opening valves of the prior art unsuitable.

Although valve to piston contact is a possibility with prior art cam driven systems, it rarely occurs because the mechanical interconnection of the various components makes such contact extremely unlikely.

In other words, potentially catastrophic valve to piston contact can occur simply because of an erroneous open command produced by the engine computer due to software errors and / or erroneous sensor inputs to the computer.

Thus, the real and perceived danger of valve to piston contact with electronically actuated and controlled valves has hindered movement in the industry to a camless engine that is completely electronically actuated and controlled.

However, outwardly opening valves have never been successfully implemented into diesel engines on a large scale because of the great difficulty in holding such valve members closed during the high pressures produced by combustion.

In those cases where outwardly opening valves have been successfully utilized, the actuation system utilized to both hold the valve closed and open the valve at desired times often requires large amounts of energy, which again renders such a system less than desirable.

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