RU2084649C1 - Method and device for preparing fuel mixture in carburetor four-stroke internal combustion engines - Google Patents

Abstract

FIELD: engine engineering. SUBSTANCE: inlet valve is arranged on the side surface of the cylinder so that to allow fuel-air mixture to enter cylinder at a pressure lower than the pressure of saturated fuel vapor. EFFECT: simplified method and device. 3 cl, 1 dwg

Description

 The invention relates to internal combustion engines, in particular to methods and systems for supplying fuel or a combustible mixture for combustion engine as well as devices for redistributing condensed fuel or homogenizing a combustible mixture. It can be applied and used in aviation, land, sea and river transport, as well as in other devices driven by an engine.

 There is a method of preparing the fuel mixture in the carburetors of four-stroke internal combustion engines, which then enters the engine cylinder and is compressed [1] In this method, there are no conditions for the complete conversion of the fuel mixture from a liquid state to vapor before burning, since the fuel mixture is sucked into the cylinder at pressure close to atmospheric. In our proposed invention, due to the supply of the fuel mixture into the cylinder at a pressure below the saturated vapor pressure of the fuel, droplets of fuel are boiled and the liquid fuel mixture is transferred to the vapor state.

 A device is known [1] in the cylinder head of which the intake and exhaust valves are located. Valves open and close using cam distributor. In the proposed device, the intake valve is located on the lateral surface of the cylinder, has, for example, a petal design and opens automatically only after the piston passes by it from the top dead center to the bottom dead center on the suction stroke.

 The technical result achieved by the application of this method of preparing the fuel mixture in the engine expressed in increasing the vacuum in the cylinder of the piston engine before the suction of the fuel mixture to a pressure below the pressure of saturated vapor of the fuel, which significantly affects the efficiency of the engine.

To obtain this technical result, a method is used to prepare the fuel mixture in internal combustion engines, which consists in converting liquid fuel in the engine cylinder to a vapor state before the compression cycle in it begins. An increase in the vacuum in the cylinder to a pressure lower than the pressure of saturated vapor of the fuel compared to the pressure close to atmospheric in the engine [1] provides:
the ability to work on low-octane fuel with an optimally high compression ratio of 12, since in this case the vaporous fuel does not detonate;
the ability to work on a very poor mixture with a fuel to air ratio of 1:36 versus 1:16 in conventional engine

 higher temperature and rate of combustion homogeneous combustion; which allows to increase the engine efficiency and its liter capacity, to reduce harmful emissions into the atmosphere and carbon formation.

 The drawing shows a longitudinal section of the engine during the first, second, third and fourth cycles.

 The following positions are given in the drawing: 1 piston engine 2 - crank mechanism; 3 cylinder; 4 inlet valve; 5 exhaust valve.

 A four-stroke carburetor internal combustion engine comprises a piston 1, a crank mechanism 2, a cylinder 3, an intake 4 and an exhaust valve 5. The inlet valve 4 has, for example, a flap design. It is located on the side surface of the cylinder 3 and opens due to the pressure differential in the cylinder and in the environment. The location of the valve 4 along the height of the cylinder is selected so that when the piston passes the valve during the suction stroke, the pressure in the cylinder is less than the pressure of saturated fuel vapor.

 The carbureted four-stroke internal combustion engine operates according to the well-known cycle [1] During the first stroke, the piston 1 (see drawing) of the engine moves from the top dead center (MW) to the bottom dead center (BDC). In contrast to the famous d.v.s. inlet 4 and outlet 5 valves are in the closed position. At the moment when the pressure in the cylinder 3 becomes lower than the saturated vapor pressure of the fuel, the intake valve 4 opens automatically and the working mixture is sucked into the cylinder 3. At the same time, droplets of fuel sprayed in the carburetor are boiled and the fuel is completely transferred to the vapor state. During the second stroke, the piston 1 moves from BDC to TDC, inlet 4 and outlet 5 valves are closed. There is a compression of the working mixture. The third stroke is the engine stroke, intake 4 and exhaust 5 valves are closed. Ignition occurs, expanding gases move piston 1 from TDC to BDC. During the fourth cycle, piston 1 moves from BDC to TDC, intake valve 4 is closed, exhaust valve 5 is open. The combustion products are released from the engine cylinder 3.

Claims (2)

 1. The method of preparation of the fuel mixture in the carburetor four-stroke internal combustion engines, which consists in converting the liquid fuel in the engine cylinder to a vapor state, characterized in that during the intake of the fuel mixture droplets of fuel are brought to a boil and completely transferred to the vapor state before combustion, and boiling droplets of fuel provide the fuel mixture into the cylinder at a pressure in it below the pressure of saturated vapor of the fuel.  2. A device for preparing a fuel mixture in a carbureted four-stroke internal combustion engine, comprising a cylinder, a piston installed in the cylinder, forming a combustion chamber with an cylinder, an intake and exhaust valve, characterized in that the intake valve is installed on the side of the cylinder and opens automatically when it is reached the pressure in the cylinder is lower than the pressure of saturated vapor of the fuel.