CS206129B1 - Double-stroke motor with valve gear controlled by the shifting elements - Google Patents

Description

The invention relates to a two-stroke engine with a timing actuated by sliding elements geared to the crankshaft.

Two-stroke engines with piston-controlled vacuum diaphragm-controlled automatic diaphragm valves are known, as well as engines with forced control by rotary or sliding elements coupled to the crankshaft. The sliding elements, i.e., usually flat or cylindrical gate valves, are operated in the prior art by means of connecting rods or cams, the movement of which is tied to the movement of the crankshaft.

A disadvantage of the known two-stroke engines with piston distribution and vacuum-operated diaphragms is the low specific power. The disadvantage of all rotary slide valves is the complicated drive of the slide valve or, in the case of slide valves mounted on the crankshaft, the carburetor bearing is disadvantageous. In the prior art systems with sliding elements, the disadvantage is the complicated design and the high inertia forces of the heavier oscillating elements not allowing high engine speeds for which the forced distribution should be intended.

These disadvantages are overcome by the device according to the invention, characterized in that in the engine there are two separate levers, pivotable around a pin, on which a thumb engages in the shaped grooves of the two crankshaft arms, the exhaust channel being operable by a lamella designed for front work; the suction channel is operable by a lamella formed on the rear lever.

The advantage of the device according to the invention is the possibility of obtaining the highest engine parameters, since forced control of the intake and exhaust allows the ideal timing to be set. The whole device is very simple; its cam is formed by a shaped groove directly in the crankshaft arm. Another advantage is the low oscillating masses since the closing element is a light lamella. The inertia forces are advantageously reduced in that they are not sliding but pivotable, the angle of which can be reduced by arranging two slats for closing one channel or even by closing the slots of a fixed grid.

An exemplary embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is a schematic longitudinal section through the engine and Figure 2 is a detail of the pivoting lever. In Figure 1, a housing 1 is shown to which the cylinder 2 and the cylinder head are connected

3. In the housing 1, a crankshaft 4 with a connecting rod 5 and a sliding piston 6 is rotatably mounted. A carburettor is connected to the cylinder 2 via the intake port 7.

8. In the housing 1 there is further provided a pin 9 around which the rear lever 10 is pivoted, the thumb 11 of which fits into the shaped groove 12 of the crankshaft arm 13.

4. On the rear lever 10 is formed a rear lamella 14 closing the suction channel 15. The exhaust channel 16 is closed by the front fin 17 of the front lever 18.

In Fig. 2 there is a detail of the rear lever 10 with the rear lamella 14 closing the suction channel 15. The thumb 11 fits into the shaped groove 12 in the arm 13

Claims (1)

SUBJECT Two-stroke engine with sliding element-controlled transmission, in particular lamellas gear-connected to the crankshaft, characterized in that on both arms (13) of the crankshaft (4) there are shaped grooves (12) in which the thumb (11) is formed. two separate crankshaft levers 4. While the engine is running, the crankshaft 4 rotates and the thumb 11 of the rear lever 10 engaging the shaped groove 12 determines the movement of the rear lever 10 and thereby the control of the rear lap 14 in the intake passage 15. lever 18. BACKGROUND OF THE INVENTION pivotable about a pin (9), wherein a fin (17) for controlling the exhaust duct (16) is provided on the front lever (18) and a fin (14) for operating the intake duct (15) is provided on the rear lever (10).