RU2206758C2 - Two-stroke internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: proposed engine has working cylinder with ring combustion chamber and inflow scavenging, working piston with crown made integral with rod and coupled with crankshaft. Piston of supercharger is arranged coaxially with working piston and is also coupled crankshaft. According to invention, nozzle chambers with mouths adjoining smaller and larger diameter of piston crown are made in rod and piston. Combustion chamber in radial section has form of segment, and at working stroke of working piston, owing to two-side tangential direction of flows from nozzle chambers, toroidal vortex is formed in ring combustion chamber. Piston of supercharger can be made two-step, ring, enclosing working cylinder and interacting with shaft in antiphase to working piston. Its inner step is coupled with air and scavenging channels, and outer step, with carburetor and automatic valves of combustion chamber. EFFECT: increased efficiency of engine at its full balancing. 4 cl, 5 dwg

Description

 The invention relates to a two-stroke two-cylinder internal combustion engine with straight-through cylinder blowing.

 Known two-stroke ICE Stelzer, containing coaxially located and rigidly connected two working pistons with rods and 2 working cylinders with straight-through purge and annular combustion chambers in the cylinder heads (patent SU 1192635, M.cl. F 02 B 71/00).

Its disadvantages:
1. The engine is completely unbalanced.

 2. There is no conversion of the reciprocating movements of the pistons into rotational for driving vehicles.

 3. Large losses of the mixture (or air) during the purge due to the placement of exhaust windows in the cylinder walls, and purge - in the central part of the cylinder.

 4. A large axial dimension that increases when the reciprocating piston rotary energy converter is installed.

 5. Large heat losses due to direct contact of the burning mixture with the walls of the working chamber and the rod.

 A two-stroke ICE is also known, comprising a piston integral with the rod and connected to the drive shaft, a direct-blowing working cylinder, a piston supercharger coaxially located and connected to the drive shaft (US Pat. Russia 2008461, Ml. F 02 B 33/02, F 02 B 25/20), adopted as a prototype.

Its disadvantages:
1. The engine is unbalanced.

 2. Large transverse dimension.

 3. Large losses of air or mixture during purging, due to the location of the exhaust windows in the side walls of the cylinder, and the purge - in its central part, large heating of the central part of the engine is unfavorable for its operation.

 4. Large heat losses due to direct contact of the burning mixture with the walls of the working chamber and the rod.

 The purpose of the invention is to achieve complete balance of the engine and increase its efficiency.

 For this purpose, in a push-pull ICE containing a piston integral with the rod and connected to the crank shaft, a direct-purge working cylinder, coaxially arranged, connected to the crank shaft of the supercharger piston, the same parts are introduced and are mirrored on the opposite side of the crank shaft and of the same name the parts are rigidly connected, the delivery pistons are made circular, covering the lower parts of the working cylinders and interacting with the crank shaft in antiphase to the working pistons.

New distinctive features in comparison with the prototype are:
1. The second piston with a rod, the working cylinder and the supercharger piston are rigidly connected from the opposite side of the crank shaft, the piston superchargers are made circular, covering the lower parts of the working cylinders and working pistons interacting with the crank shaft in antiphase.

 2. In the working cylinders, the inlet windows are controlled by working pistons, and the exhaust by their rods.

 3. In the rods and pistons are made nozzle chambers with mouths adjacent respectively to the small and large diameters of the piston bottom.

 4. The annular combustion chambers are made with radial partitions, and the surface of the chambers is coated with a catalytic layer.

 5. The supercharger is made with two-stage pistons and cylinders, the inner stage is connected with air and purge channels, the external stage is connected with channels with a carburetor and automatic valves.

 In FIG. 1 shows a longitudinal section of an engine; figure 2 is a transverse section of the engine in figure 1; figure 3 is a longitudinal section of the engine during the working stroke of the upper piston and the compression stroke in the lower cylinder; figure 4 is a section aa in figure 1; figure 5 is a longitudinal section of an engine with stepped discharge pistons.

 The engine contains coaxial pistons 1, 2, rigidly connected by jumpers 3 and made integral with rods 4, 5, working cylinders 6, 7 with working chambers 8, 9 and annular combustion chambers 10, 11, a supercharger 12 with coaxial ring pistons 13, 14, rigidly connected by massive jumpers 15 / Fig. 2 / and located in the coaxial cylinders 16, 17, the crank shaft 18 interacts with a cracker 19 with the lower parts / wings / 20, 21 of the pistons 1, 2 and with two cylindrical cams / eccentrics / 22, 23 with the bottoms of the pressure pistons 13, 14. In the rods 4, 5 and the working pistons 1, 2 there are nozzle chambers 24, 25 with nozzle mouths 26, 27. In the combustion chambers 10, 11, automatic valves 26 for supplying compressed gas or rich air-fuel mixture are installed. The combustion chamber 10, 11 has radially spaced rib walls 29.

In figure 1, 2, the rigidly connected working pistons 1, 2 are in the uppermost position, in the upper working cylinder 6 the piston 1 bmw, the combustion process is going on and the working stroke begins. In the lower working cylinder 7, the piston 2 is in NMT, there is an exhaust and purge with clean air, automatic valves 28 for supplying compressed gas or rich mixture are opened. And in the supercharger 12, the rigidly connected pressure pistons 13, 14 are in the lowest position, in the upper pressure cylinder 16 the piston is in N.M.T. There is an air inlet through the plate valve 30. In the lower pressure cylinder 17, the piston 14 is in bm, compressed air is supplied through the purge channels 31 to the lower working cylinder 7. After the crank shaft 18 is rotated 180 ^{°, the} processes in the cylinders 6, 7, 16, 17 are reversed.

 At the end of the piston stroke 1/2 /, the exhaust port 32 opens, the exhaust gas starts, then the purge windows 31 open, air purge begins, the pressure in the working chamber 8/9 / drops, automatic valves 26 and combustible gas or a rich gasoline-air mixture open pressure greater than the air pressure during purging, enters the compression chamber / KS / 10/11 /. After the piston passes 1/2 / Nm.t., when the piston 1/2 / rises, the purge 31 and outlet 32 windows overlap, compression begins in the working chamber 8/9 /, the pressure rises, air begins to enter the nozzle chambers 24, 25, and the automatic valves 28 are closed due to the inertia of the parts of the valve 28 and the gas / mixture / due to the kinetic energy of the flow continues to flow to the compressor 10/11 /, the fuel charge is recharged after closing the exhaust port 32. When the piston is further raised 1/2 / air enters the nozzle chambers, then gas / mixture /. With the approach of the piston 1/2 / k VMT ignition of the mixture occurs, ignition and the beginning of combustion. The pressure in the working chamber 8/9 / grows, the migration of the mixture into the nozzle chambers 24, 25 increases, near VMT at maximum pressure, the nozzle chambers 24, 25 are charged. This is favored by the peculiarity of the crank-rocker mechanism used — longer time for the piston 1/2 / to V. M. T. The hot mixture delivered to the nozzle chambers 24, 25, giving off heat to the walls of the nozzles 26 , 27, enters without turbulence and mixing with previously entered air and mixture.

 When lowering the piston 1/2 / lower V.M.T. the pressure in the working chamber 8/9 / becomes less than in the nozzle chambers 24, 25, therefore, the last hot mixture entering the nozzle chambers 24/25 / with high speed, thanks to the nozzle effect, returns back to the annular flame chamber КС 10/11 strengthening it and, thanks to the two-sided tangential direction of the nozzle flows, twisting into a toroidal vortex 33. The rod 4 and the segmented shape of KS 10/11 / contribute to the nucleation and preservation of the vortex 33. The outer layer of the shell of the vortex 33, in contact with the cold walls of the working chamber 8/9 / and fed vayas cold flow and air mixture from the nozzles 26, 27, does not participate in combustion. The toroidal vortex 33 is relatively stable and is stored in the working chamber 8/9 / BC m.t. The counter direction of high-speed flows from nozzle chambers 24, 25 to KS 10/11 / after high-speed motor and a toroidal vortex 33 during the working stroke of the piston 1/2 / provides a high rate of combustion of the mixture and a high pressure in the working chamber 8/9 /, the exhaust gas toxicity and the detonation multiplicity are reduced, which makes it possible to increase the compression ratio in CS 10/11 /.

The interaction of the cracker 19 of the crank 34 with the lower parts / wings / 20, 21 of the pistons 1, 2 simplifies the design of the two-cylinder engine, reduces its transverse dimension and weight, increases the possible number of revolutions and engine power. Coaxial, rigidly connected working 1, 2 and injection 13, 14 pistons interact with cranks 22/23 /, 34 of the shaft 18, shifted 180 ^o , so when working they move towards each other, with their respective masses and radii of the cranks 22/23 /, 34 full engine balance is ensured. Due to the free choice of the external diameter of the injection pistons 13, 14 and the size of the compression chamber 10, 11, it is possible to obtain the optimal values of productivity and discharge pressure for high-quality purging and charging of the engine cylinders 6, 7, it is possible to reduce the stroke of the delivery pistons 13, 14, their speed and pump losses. It becomes possible to place the supercharger 12 below the purge windows 31, use the clowns 22, 23 as cranks, which simplifies the design of the crank shaft 18.

 The pistons 13, 14 of the supercharger 12 are equipped with buffer springs 35, this allows you to get a power oscillatory circuit and to reduce the maximum load in the drive parts.

 When the engine is running, the transverse loads on the twin pistons 1, 2 that occur during the working stroke of the pistons 1, 2 when the center of the crank 34 is offset from the axis of the cylinders 6, 7, are perceived by the side surfaces of the two pistons 1, 2 located on opposite sides of the crank shaft 18, this reduces their size and reduces friction power losses, reduces wear.

 A rigid connection of the pistons 1, 2 is carried out inside the mirror of their cylinders 6, 7, this reduces the weight of the twin pistons 1, 2, simplifies the design and manufacturing technology, increases the reliability of the connection. Opening and closing of the exhaust window 32 is carried out by the stem 4/5 /, and the purge windows 31 - by the piston 1/2 /. The area of the exhaust window 32 is less than the area of the purge windows 31, therefore, the loss of injected air through the later closed outlet 32 is less / in the prototype, on the contrary /. When released, the exhaust gas pressure acts on the end surface of the stem 4/5 / and further increases the force effect on the piston 1, / 2 /, increasing the engine torque.

 It becomes possible to purge by rotating around the stem 4/5 / by means of the tangential inclination of the purge channels 31, cooling and cleaning of the exhaust gas of the working chamber 8/9 / are improved. Axial rotation of air is especially necessary when using compressed gas as a fuel - for mixing it with air before ignition. Efficient direct-flow blowing with compressed air allows to reduce the height of the windows 31, 32, to increase the degree of utilization of the piston stroke.

 The radial baffle ribs 29 in the combustion chamber 10, 11 during compression of the mixture, with the approach of the piston 1, 2 to VMT slow down the speed of rotation of the charge around the rod 4, / 5 /, this increases the reliability of ignition during start-up. The presence of a catalytic layer (for example, a platinum layer with a thickness of 20 μm) on the walls of KS 10, 11 provides self-ignition of the mixture at the end of the compression stroke / spark only for starting the engine /. When gasoline is used as fuel, the superchargers 12 are made with step pistons 13a, 14a and cylinders for separate compression of air and gasoline-air mixture. The processes in the stages of the supercharger coincide, this simplifies their isolation from each other / Fig. 5/.

 Reduced maximum combustion pressures and temperatures provide soft engine operation and a small amount of nitrogen oxides in the exhaust gas. The combustion of the bulk of the mixture in a toroidal vortex 33 at a high flow rate and isolation with a layer of air from the cold walls of the working chamber 8/9 / provides a high rate of combustion of the mixture, high temperature and pressure, increases the work of expanding gases and reduces the toxicity of exhaust gases. Heat losses are reduced, internal adiabatization occurs - with "cold" walls of the working chamber, the lubrication conditions of the pistons 1/2 / are improved, and mechanical losses are reduced.

Advantages of the engine:
- complete balance,
- smooth and soft work,
- separate lubrication,
- effective direct-flow purge with clean compressed air in the supercharger 12,
- reliable ignition during start-up and operation,
- stratification of the fuel charge provides low fuel consumption,
- intensified thermal process and internal adiabatization with relatively cold walls of the working chamber,
- low exhaust emissions
- high-quality and partially high-quality power control when working on gas and gasoline, respectively
- small transverse dimension and weight,
- small mechanical losses.

 All this increases the efficiency of the engine.

Claims (4)

 1. Two-stroke internal combustion engine containing a working cylinder with an annular combustion chamber and direct-flow blowing, a working piston with a bottom made integral with the rod and connected to the crank shaft, a supercharger piston located coaxially with the working piston and connected to the crank shaft, characterized in that nozzle chambers with mouths adjacent to the small and large diameters of the piston bottom are made to the rod and piston, the combustion chamber having a radial section in a segment shape, and due to the bilateral tangential direction of flows of nozzle chambers when working stroke of the working piston is twisted torus-shaped swirl.  2. ICE according to claim 1, characterized in that the combustion chamber is made with fins-baffles and coated with a catalytic layer.  3. ICE according to claim 1 or 2, characterized in that the purge windows are controlled by working pistons, and the exhaust windows by their rods.  4. ICE according to any one of claims 1 to 4, characterized in that the piston of the supercharger is made of a two-stage annular, covering the working cylinder and interacting with the shaft in antiphase to the working piston, while its internal stage is connected with air and purge channels, and the external stage is with carburetor and automatic combustion chamber valves.

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