RU2514468C2 - Two stroke ice with supercharging - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention may be used in automotive industry. Proposed engine with gas exchange crank-chamber comprises cylinder (8) with piston (4) furnished with two piston pins and two crankshafts (2) arranged in symmetry about cylinder axis (8). Every crankshaft (2) is coupled by con-rod (3) with one of piston pins. Compressor (16) cylinder is arranged on engine inner bottom side coaxially with cylinder axis (4). Compressor piston (13) is coupled by rod (12) with engine piston (4). Compressor (16) outer chamber is communicated via channels with crankcase chamber. Inner chamber of compressor (16) is isolated from crankcase chamber by means of sealing bush (5) arranged at rod (12). Bush (5) is locked between two halves of said crankcase.

EFFECT: possibility to replenish engine cylinder.

2 cl, 2 dwg

Description

The present invention relates to the field of engine building, in particular to two-stroke engines with a crank-chamber gas exchange scheme containing a cylinder, a piston with two piston fingers placed therein, two crankshafts symmetrically located relative to the axis of the cylinder, each of which is connected by a connecting rod to one of piston fingers [1].

These engines have a number of advantages, the main ones being the possibility of balancing the inertia forces of the reciprocating moving masses only due to the counterweight of the crankshaft, the absence of forces causing increased piston friction against the cylinder walls, the absence of reactive torque, improved specific energy and economic parameters in terms of power, mass and dimensions. However, taking into account the growth rate of the parameters of classic two-stroke carburetor engines with a crank-chamber gas exchange scheme and the need to ensure the competitiveness of the proposed engines made according to the scheme of one cylinder - two crankshafts, the need to develop measures to further increase the liter capacity and reduce the total mass of the engine installation becomes obvious .

A significant increase in engine power is achieved through the use of boost. Only the use of pressurization due to wave phenomena in exhaust systems in modern “two-stroke engines” makes it possible to increase their power by 40% [2], however, due to their large size and considerable mass, such systems are not acceptable for portable products.

For pressurization of two-stroke engines with a crank-chamber gas exchange scheme without the use of tuned exhaust systems, compressors (superchargers) are needed, in which air or a combustible mixture is compressed before they enter the cylinder, and the possibility of recharging, for which the exhaust windows in the cylinder, as a rule, should close before inlet.

Engines are known, for example, designs by A. Ivanitsky [3], which use autonomous compressors and asymmetric gas distribution phases to ensure high energy and economic parameters due to the use of two-piston engines with one of the crankshafts shifted along the rotation angle. Known engines "Zoller" (prototype) [3], characterized by a built-in compressor with a crankcase of variable volume and ensuring the asymmetry of the valve timing in a similar way due to the presence of a second piston controlled by a trailed connecting rod. To drive the crankcase (pressure) piston, an additional connecting rod is used, articulated with an eccentric on the crankshaft of the engine.

Similar designs are commonly used for sports engines that, for economic reasons, cannot compete with conventional single-cylinder engines of the same power achieved by simply increasing the volume.

The technical result of the proposed design solution is to increase engine power by increasing the average effective pressure by at least 25 ... 30% by applying boost while reducing its specific gravity by 15 ... 20%, which will provide it with competitiveness in a common market.

To achieve this result, a two-stroke internal combustion engine with a crank-chamber gas exchange scheme, comprising a cylinder, a piston with two piston fingers placed therein, two parallel crankshafts symmetrically located relative to the axis of the cylinder, each shaft being connected by a connecting rod to one of the piston fingers, equipped on the inside with an integrated compressor (supercharger) coaxially with the axis of the engine cylinder, the piston of which is connected to the engine piston by a piston, and the outside (supercharger) A N) of the pump chamber is connected by channels with crankcase space and serves to increase its filling with a mixture of fuel and an inner cavity isolated from the crankcase space by means of a sealing sleeve accommodated in said housing, and can be used as a compressor for household purposes; at the same time, to carry out recharging, the engine cylinder is equipped with additional inlet windows located above the main ones with inlet phases exceeding the exhaust phases, and to prevent the products of burned fuel from entering the crankcase into the crankcase, a check plate valve is installed in the plane of their connector, which blocks access to gases into the crankcase when the pressure in it is less than the pressure in the cylinder.

Figure 1 shows a cross section of the proposed engine, consisting of two halves of the crankcase 1, in which crankshafts 2 are located, connected by connecting rods 3 to the piston 4. The piston has a head located not in the upper part of the piston, but somewhat lower, forming as if from above miniskirt with inlet (purge) windows 6 matching the same windows in cylinder sleeve 7 of the cylinder 8. Outlet windows 10 are located above the upper edge of the piston skirt at its position at bottom dead center (BDC). The design of the OPK 9, installed between the cylinder and the crankcase, can be performed in various ways, for example, see figure 2. A carburetor (not shown) is mounted on the compressor cover 16, also equipped with an OPK 15. The rod 12 has a sealing sleeve 5 fixed between the halves of the crankcase, and a plastic piston 13 with a compression ring 14. The compressor cylinder is equipped with a sleeve. To intensify the combustion process, the combustion chamber is connected to the annular space by tangential channels 11. When using the engine as a motor compressor, the internal cavity of the pump 17 is equipped with a valve box 18 with suction and discharge valves located on the plate 19.

The use of engines using the proposed technical solutions is advisable for the drive of various mechanisms, which are subject to high requirements for specific gravity and dimensions. Given the presence of two drive shafts in the engine rotating in opposite directions, they are especially promising for the creation of portable compressors and pumps of the rotary gear type for mechanisms with pneumatic and hydraulic drives.

The results of the design study of the engine with a working volume of 75 cm ³ made according to the scheme one cylinder - two crankshafts, showed that the use of an integrated compressor (supercharger) with a diameter equal to the diameter of the engine cylinder, as well as OPK and other parts for recharging the cylinder, increases its weight by about 8% (400 g), which, taking into account the increase in power by only 25%, reduces its specific gravity by 17% and provides it with competitive advantages compared to conventional engines.

For information: the literature provides information that boost increases engine power from 40 to 100% or more [4]).

List of documents mentioned in the description

1. Two-stroke internal combustion engine. Patent RU No. 116906 U ₁ (Bednyagin L.V., Lebedinskaya O.L., publ. 06/10/12. Bull. No. 16).

2. Two-stroke engines in aviation. Alexander Gomberg (http: // engine.aviaport.ru/issues/02/page 38.html).

3. Gusev EM, Osipov MS A manual for car makers. - M.: Publishing House of DOSAAF USSR, 1980 (p. 72, fig. 59 d, 59 g, p. 7).

4. Heat engineering. Textbook / Hazen M.M., Matveev G.A., Grinevsky M.E. et al. Ed. G.A. Matveeva. - M.: Higher school, 1981.

Claims (3)

1. A two-stroke internal combustion engine with a crank-chamber gas exchange scheme, comprising a cylinder, a piston with two piston fingers placed therein, two crankshafts symmetrically located relative to the axis of the cylinder, each of which is connected by a connecting rod to one of the piston fingers, characterized in that from its inner bottom side coaxial to the axis of the cylinder there is a compressor cylinder (supercharger), the piston of which is connected to the engine piston by the rod, the external cavity of the compressor is connected by channels to the inside rternym space, its internal cavity is isolated from the crankcase space via a sealing sleeve located on the rod with its fixation between the two halves of the crankcase. 2. The engine according to claim 1, characterized in that the cylinder of the engine is equipped with additional inlet (purge) windows located above the main windows with inlet phases exceeding the exhaust phases, while the opposite (s) are placed between them in the plane of the cylinder and crankcase connector (s) f) lamellar (e) valve (s) preventing (e) the entry of products of burnt fuel from the cylinder into the crankcase when the pressure in it exceeds the pressure inside the crankcase. 3. The engine according to claim 1, characterized in that a double-acting piston pump is used as a compressor (supercharger), the outer cavity of which provides an additional supply of the fuel mixture to the crankcase, and the inner cavity is used to supply compressed air to the consumer.

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