JPH07305611A - Four cycle engine having intake control valve - Google Patents

Abstract

PURPOSE:To dispense with an intake valve, improve heat efficiency, attain low-pollution and save energy by providing a control valve such as a rotary valve and a lead valve in an intake system of a uniflow type engine. CONSTITUTION:A control valve 2 is arranged on a downstream side of a supercharger 1 in an intake system of a uniflow type engine. A control valve 2 is opened in the vicinity of a bottom dead center of a piston 3 of the engine, so that intake is conducted from an intake port into a cylinder. The intake port is closed in a succeeding process where the piston 3 is lifted, that is, a compression process. Explosion is conducted in the vicinity of a top dead center, and shifting to an expansion process is conducted. In the explosion process, the control valve 2 is opened in order to prevent contraflow to an intake system. Afterward, an exhaust valve is opened and shifting to an exhaust valve is conducted. The exhaust valve is closed in the vicinity of the top dead center for completing one cycle. Reciprocating motion of the piston 3 in one cycle is extracted as power through a crank shaft or the like.

Description

The present invention relates to a four-cycle engine, which is characterized in that a control valve is provided in an intake system of a uniflow type engine. Explaining the process of this plan, the control valve opens near the piston bottom dead center, and intake air enters the cylinder through the intake port. The piston then rises, closing the inlet and entering the compression stroke. Then, it explodes near the top dead center and expands to the bottom dead center. The expansion stroke control valve is closed to prevent backflow into the intake system. Next, the exhaust valve opens, and the exhaust stroke goes to top dead center. The exhaust valve closes near top dead center and the piston moves down while lowering the temperature inside the cylinder. With this structure, the proposed design eliminates the need for an intake valve in the cylinder head, and it is possible to add spark plugs and fuel injection valves to that space. This enables uniform combustion in the cylinder and reduces NOX and HC. Also, since the compression ratio <expansion ratio, the thermal efficiency is improved,
It also helps save energy and reduce CO2. Furthermore, if a variable device, which is often used for the exhaust port of a 2-cycle engine, is applied to the intake port, it becomes possible to control the compression ratio and output, enabling a more efficient engine. It is especially effective if attached to the top and bottom of the intake port.

[Brief description of drawings]

FIG. 1 is a system diagram of claim 1 of the present invention.

[Explanation of symbols]

(1): Supercharger (2): Control valve
(3): Piston

Claims (1)

[Claims] 1. A four-cycle engine in which a control valve such as a rotary valve or a reed valve is provided in an intake system of a uniflow type engine.