RU2539230C1 - Two-piston engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: engine comprises cylinder with opposed pistons (3, 4). The latter are coupled with con-rods (5, 6) resting on crankshafts (7, 8). Said shafts are timed by mechanical gearing so that pistons can displace both to the right or to the left. Note here that clearance between pistons varies due to variation in horizontal projections of periodically inclining con-rods. Spark plug 1 is arranged nearby one edge of the cylinder while intake opening with check valve (9) communicated with fuel mix feed channel (10) is located nearby the other edge and discharge opening with check valve (11) communicated with exhaust channel (12).

EFFECT: simplified design, higher efficiency and reliability, decreased noise level.

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Description

Refers to mechanical engineering, namely to internal combustion engines.

To date, a huge variety of designs of internal combustion engines with various designs of the working bodies forming the expansion chamber has been proposed. A small group can be distinguished from them, characterized by the opposing arrangement of two pistons in one cylinder. The main advantage of such motors is to increase the specific power and reduce vibrations due to the out-of-phase movement of the pistons [1]. However, the inevitable complexity of the design is not compensated by the benefits.

There are examples of an extraordinary approach in this direction, where, in order to simplify gas distribution, the movement of pistons is carried out according to a complex law defined by their conjugation with the crankshaft through intermediate elements [2]. A significant drawback of this technical solution is the increased strength requirements of the said intermediate elements experiencing shock loads from the piston.

The objective of the invention was to develop an extremely simple internal combustion engine with a pair of pistons in cylinders without a forced gas distribution system.

As a prototype was taken the simplest valveless engine with the location of two pistons in one cylinder [3].

The essence of the invention is illustrated in figure 1, which shows the different stages of the engine, and the bottom indicates the main elements. The spark plug 1 is passed through the wall of the housing 2 to a cylindrical cavity, from the ends of which are inserted pistons 3 and 4, articulated with connecting rods 5 and 6, in which crankshafts 7 and 8 are connected through openings at the ends, interconnected by a mechanical transmission (not shown ), allowing pistons 3 and 4 to move only in the same direction: both to the right or both to the left. The housing has inlet and outlet windows, respectively, connecting the specified cavity through the check valve 9 with the feed channel of the combustible mixture 10 and through the check valve 11 with the exhaust channel 12.

The device operates as follows. With the conditionally initial angle of synchronous rotation of the crankshafts φ = 0 °, the pistons 3 and 4 are in the extreme left positions, and there is a slight gap between them. When turning the crankshafts 7 and 8 clockwise, the pistons move to the right, and the tilt angles of the connecting rods 5 and 6 increase. This leads to a shortening of their horizontal projections and, as a consequence, the relative divergence of the pistons. The resulting vacuum opens the valve 9 for the flow of the combustible mixture from the channel 10. There is a stroke "Inlet", ending at φ = 90 °, when the gap width reaches its maximum value.

With the subsequent rotation of the crankshafts, the pistons continue to move to the right, but already approaching each other and compressing the combustible mixture. The “Compression” stroke occurs, ending at φ = 180 °, which corresponds to the extreme right positions of the pistons. The cavity between the pistons is opposite the candle 1, which ignites the combustible mixture, leading to a sharp increase in pressure of the resulting combustion products. Obviously, in the simplest case, spark voltage can be applied continuously.

From the general principles of mechanics it follows that although gases press on both pistons, they are obliged to change the state of the system in the direction of increasing volume, i.e. widening the gap between the pistons, which just begins after passing the extreme right positions. This statement is easy to prove by examining in detail the difference in the torque acting on the crankshafts. There is a stroke "stroke", ending at φ = 270 °, when the second maximum of the relative divergence of the pistons is reached.

Then, when turning to φ = 360 ° (which is equivalent to φ = 0 °), “Release” occurs. Compressed gases between the pistons open the valve 11 and go into the exhaust channel 12.

Thus, one reciprocating piston cycle covers four standard strokes of a traditional internal combustion engine. For greater clarity, figure 2 shows the changes in horizontal coordinates x of the inner edges of the left (L) and right (P) pistons in the entire range of angles φ.

If the radius of the crank at the right crankshaft is greater than that at the left, it is easy to set a very close convergence of the pistons in the extreme left positions, regardless of the size of the gap between them in the extreme right positions (Fig. 3). This allows you to ensure the maximum possible completeness of absorption and release.

By introducing a slight lag in the angle of the right crankshaft from the left, it can be done so that the degree of expansion during the stroke is greater than the compression ratio of the combustible mixture. This can be seen in figure 4, where the lag is 10 °, and the angle φ refers to the left shaft. This circumstance makes it possible to increase the efficiency of the engine.

The combustible mixture is formed in a carburetor or mixer for gaseous fuels. The exhaust channel is connected to the exhaust pipe. A series of cylindrical cavities surrounded by a single liquid cooling jacket can be arranged in the engine housing. For them, the channel for supplying the combustible mixture, the exhaust channel and crankshafts will be common. The rotation of the crankshafts can be not only the same (as shown in figure 1), but also the opposite, provided that the moments of the horizontal arrangement of each pair of connecting rods coincide (minus the possible lag).

The absence of a forced gas distribution system leads to a significant reduction in noise levels, increased reliability and simplified engine operation.

The technical result of the invention is simplicity, economy, high reliability and low noise.

Information sources

1. US patent No. 1308400 from 01.07.1919

2. RF patent No. 2009347 of July 16, 1990.

3. US Patent No. 898913 of September 15, 1908.

Claims (1)

A two-piston engine containing at least one cylinder, in the walls of which there is a spark plug, inlet and outlet windows, and pistons pivotally connected to connecting rods inserted through the ends at the ends of which crankshafts are connected, connected by a mechanical transmission , characterized in that both pistons have the ability to move only in the same direction, and the inlet and outlet windows contain check valves.

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