FR2578289A1 - Internal combustion engine in which the fresh gases are fed in and precompressed by a cylinder separate from that employed in detonation and expansion of the gases - Google Patents

Abstract

Internal combustion engine, suitable for all uses, in which the various functions of the cycle are performed in two cylinders of different volume, which allows the ignited gases to expand much more fully before their discharge into the atmosphere and hence gives an improved thermal efficiency and less pollution. On the scale of the drawing, the admission-expansion ratio is 1/2.6. Each group of two cylinders performs one complete cycle per revolution. The drawing shows the cycle at the start of transfer: Inlet valve 1; Transfer valve 2; Exhaust port 3.

Description

Internal combustion engine in which the functions of suction of fuel gases and precompression, expansion, exhaust, are carried out in separate cylinders. This arrangement makes it possible to reserve for gas expansion a considerably greater volume than that of carburetted gases, admitted and compressed at the maximum rate compatible with the detonating properties of the fuel, than in conventional two or four stroke engines. hence better use of thermal energy and reduction of pollution, the gases being better burned. (At the scale of the drawings this proportion is 2.6 / I.)
WORKING
Cylinder A reserved for the suction and pre-compression of carburetted gases is connected to the intake manifold by means of valve N 1, it communicates with cylinder 8 by a very short channel (3), controlled by the N 2 valve, called transfer valve.

First stage of the cycle (Figures I, 2 and 3)
The piston of cylinder B, repo @ ssé by the explosion, descends to bottom dead center, as well as piston A, whose connecting rod is driven by the same crankshaft, but with an angular advance of 60 (Figure 6). The descent of this piston determines the suction of carburetted gases, the valve N 1 opening with a delay of 30 @, to avoid the discharge of residual gases.

At 45 @ before bottom dead center the piston of cylinder B releases the exhaust port (s). The transfer valve opens fifteen degrees before the obstruction of the exhaust port (s) is obstructed, in order to allow a slight flushing of part of the burnt gases not discharged into the atmosphere; note that the fresh gases repel the burnt gays from top to bottom and not laterally as in the classic two-stroke, hence the very low risk of entrainment of fuel gases. (The opening of this hunting angle will, of course, be determined to obtain the best performance.)
Second cycle time (Figure 4)
Resuming its upward stroke the piston A compresses in front of it the carburetted gases, until their total transfer in the cylinder B, when it arrives & at its top dead center, the valve 2 closes @ and the compression is completed at optimum rate.

The explosion then determines the start of a new cycle.

Legend of the abbreviations appearing on the drawings, plates 1/2 and 2/2
OA = Opening the intake valve
OT n "" of the transfer valve.

 O.E. = "" exhaust.

 F.E. = Closure of the exhaust.

 F.T. = "n of the transfer valve.

 L.E. = Exhaust light.

4 = Appendix to avoid the communication of the casing with the exhaust, in the high position of the piston (If it turns out to be necessary for construction.)
Figure 5 = direction of motor rotation, seen from the front.

 Figure 6 = offset of the crank pins on the crankshaft.

 Figure 7 on board 2/2 n Diagram of operation of cylinder B, with an estimate of the angles corresponding to the different points of the cycle.

 Figure 8, same diagram, but specific to cylinder A.

 Of course the different angles indicated on the diagrams should be determined at best, for optimum performance.

It would be beneficial to keep the engine half speed for the rotation of the camshaft, in this case this shaft would have double cams, opposite 180 @
The reduction of the intake-expansion ratio can be envisaged in a different way from that of the operating diagram shown on the 1/1 s plate instead of a cylinder A of bore less than the cylinder B, we could use cylinders of same diameter, but in this case the rod of A, longer, would be controlled by a shorter crank pin, to limit the stroke.

Claims (4)

 t) Device constituting a modification of the constitution and operation of an internal combustion engine, of two or four stroke cycle, characterized by the presence, for each complete cycle, of two cylinders of different volume. The smallest, (A), is reserved for the suction and the precompression of the carburetted gases, which are coated transferred into the cylinder (B), of much larger volume, in which the explosion and the expansion of the ignited gases.  2) Device according to claim 1 characterized by the transfer of gas from cylinder A to cylinder B provided by a very short channel and small section, opening at the head of cylinder B (3), allowing the passage of ees-gas after opening of the transfer valve (2)  3) Device according to claims I and 2:, characterized by the angular offset of the crank pins on the crankshaft (Fig.6) This offset permitting cylinder A to be punched at top dead center ahead of top dead center in cylinder B The transfer thus being total allows the completion of the compression before the zene where ignition occurs.  4) Device according to one of the preceding claims, characterized by the valve control provided by a camshaft rotating at half speed, but comprising double cams opposite 180