Variable intake valve assembly for internal combustion engine

Abstract

An intake valve assembly of an internal combustion engine that includes a combustion chamber and an intake passage. The intake valve assembly comprises an intake valve movable into and out of engagement with a valve seat, a reciprocating primary valve tappet, and a secondary valve tappet axially non-movably attached to the primary valve tappet. The intake valve is mounted to the primary valve tappet and axially freely movable relative thereto. The primary valve tappet is configured for axially engaging the first intake valve to limit the axial movement thereof said intake valve away from the valve seat. The secondary valve tappet is configured for axially engaging the intake valve for mechanically moving the intake valve away from the valve seat. The intake valve is further operated fluidly in response to pressure differential between the intake passage and the combustion chamber.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This Application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 61 / 041,382 filed Apr. 1, 2008 by Ralph Moore.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to internal combustion engines in general and, more particularly, to an intake valve assembly of an internal combustion engine.[0004]2. Description of the Prior Art[0005]In a conventional internal combustion engine, intake and exhaust poppet valves regulate the gas exchange. A valve train (i.e. cams, drive gears and chains, rocker arms, push rods, lifters, etc.) regulate the poppet valves. Fixed valve timing of the poppet valves of the conventional internal combustion engine, and especially of the intake valve, represents a compromise between two conflicting design objectives: 1) maximum effective pressure within a cylinder, thus torque, at the most desirable points in a range of engine operating speeds, and 2...

AI Technical Summary

Benefits of technology

"The present invention provides an intake valve assembly for an internal combustion engine that allows for variable valve timing to improve engine performance at both low and high speeds. The assembly includes an intake valve, a primary valve tappet, and a secondary valve tappet. The intake valve is movable between a closed and open position and seals the combustion chamber from the intake passage when in the closed position. The primary valve tappet engages the intake valve and limits its movement, while the secondary valve tappet moves the intake valve away from the valve seat. The intake valve is operated both mechanically and fluidly in response to pressure differential between the intake passage and the combustion chamber. The invention reduces cost and complexity of the valve assembly and requires minimal modification to existing engines."

Problems solved by technology

The higher the RPM at which maximum power occurs, and the wider the range of an engine operating speed, the less satisfactory will be the ultimate compromise.

However, efficient valve timing at valve overlap (especially intake valve opening) is sensitive to the engine speed.

Too late intake valve opening at high engine speeds prevents good exhaust gas scavenging and cylinder charging.

This will also reduce the power of the engine.

However, this approach is complex and expensive, and takes away from durability of the internal combustion engine.

Thus, the intake valve assembly of the prior art, including but not limited to those discussed above, are susceptible to improvements that may enhance engine performance.

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