US2239262A

US2239262A - Four-stroke explosion engine

Info

Publication number: US2239262A
Application number: US236308A
Authority: US
Inventors: Violet Marcel Achille
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-10-23
Filing date: 1938-10-21
Publication date: 1941-04-22
Anticipated expiration: 1958-04-22

Description

April 22, 1941. M. A. VIOLET FOUR-STROKE EXPLOSION ENGINE Filed Oct. 21, 1938 Patented Apr. 22, 1941 FOUR-STROKE EXPLOSION ENGINE Marcel Achille Violet, Nanterre, France Application October 21 In France 4 Claims.

At the present time a great number of distribution devices for internal combustion engines of the four stroke type are already known, these devices including valves, sliding or oscillating sleeves or the like, rotating valves, and so on. Rotary valves, in particular, have the advantage 1938, Serial No. 236,308

ctober 23, 1937 of being noiseless, when working at very high speed, of making it possible to give the explosion chamber a suitable shape, and so on. However, such valves suffer from the disadvantage that, by reason of the fact that they are heated up to a very high temperature by the exhaust gases, proper lubrication is rendered extremely diflicult and makes it necessary to provide play which prevents a satisfactory fluid tightness being obtained.

The chief object of the present invention is to provide a device, including a rotary valve, which avoids these drawbacks.

According to a feature of the present invention, most of the exhaust gas is evacuated through orifices opened by the piston at the end of the downward stroke thereof. With such an arrangement, it is possible to open the distribution valve for the outflow of the exhaust gases only when the cylinder contains but a small part of the residual gases, these remaining gases being expanded and cooled. Consequently it is possible to avoid the heating of the rotary valve to an excessive temperature.

According to another feature of the present invention, I improve the filling of the cylinder with fresh gases by producing, at the end of the inlet stroke, through the orifices above mentioned, a supplementary suction. This permits of obtaining a further infiow of fresh gases into the engine, although the cylinder and the explosion chamber are already filled with fuel mixture at this time. However, it is necessary to take care that the suction is not too great, in order to avoid losing a certain amount of fresh gases which would escape through said orifices.

Other objects and advantageous features of the present invention will become apparent from the following detailed description of two specific embodiments thereof.

Two embodiments of the present invention will be hereinafter described, with reference to the accompanying drawing, given merely by way of example, and in which:

Fig. 1 is a vertical section of the cylinder of a single cylinder engine provided with a distribution system made according to the present invention, the piston being shown, in this view, at the end of its downward stroke;

Fig. 2 is a diagrammatic horizontal section of a multi-cylinder engine provided with dis tribution means made according to the present invention.

In Fig. 1, reference numeral I designates the cylinder; 2 is the piston, and 3 the rotary valve, turning at half-speed, which places the inside of the cylinder in communication successively with the exhaust pipe 4 and with the inlet pipe 5. Immediately above the level of the top of the piston when it is in the position shown by the drawing, there is provided an orifice 6. When the piston is in the position shown, the orifice 6 connects the inside of the cylinder with an exhaust pipe 1 provided with a light check valve 8. A chamber 9, the volume of which is substantially greater than the volume swept in the cylinder by a full stroke of the piston is provided between orifice 6 and check valve 8. This chamber is to ensure a smooth running of the engine under all conditions, especially at low speeds and when idling.

The operation of the engine above described is the following:

Piston 2, being in its downward stroke, finally reaches the position shown by Fig. 1. As soon as orifice 6 is opened, the high pressure gases escape, for the most part, through orifice 6 and pipe I. As soon as piston 2 has moved bad: in the upward direction and has covered orifice 6, rotary valve 3 opens the connection with pipe 4 and the burnt gases continue to escape from the cylinder, passing now into said exhaust pipe But as most of the hot gases have already escaped through pipe 1, the residual gases which now flow through the rotary valve are already expanded and consequently somewhat cooled, so that they do not heat the rotary valve excessively. At the end of the upward stroke, the upper face of the piston is at the position indicated by dotted line l0. As soon as the piston starts moving down, valve 3 comes into a position such that the inside of the cylinder is no longer connected with the outlet pipe 4 but is now connected with the inlet pipe 5. Suction of fresh gases into the cylinder now takes place. On the other hand, immediately after the escape of the exhaust gases through pipe I, check valve 8 will have come back onto its seat, and the gases remaining in chamber 9 will by this time have cooled down and will have produced a partial vacuum in said chamber. Therefore, now, atthe end of the suction stroke, when orifice 6 is uncovered by piston 2, the vacuum chamber 9 will suck partof the gases out of the cyl- Although I have described a device according to the invention as applied to a single cylinder engine, it can be applied to a multi-cylinder engine. Fig. 2 shOWS, by way of example, an embodiment of a four stroke engine provided with such an exhaust arrangement. In this case, the four cylinders A, B, C, and D are each provided with an exhaust pipe 20A, 20B, 20C,'and 20D, respectively, corresponding to pipe I of the preceding embodiment. These exhaust pipes are bent in the direction of the gaseous stream and they open into a manifold 2! closed at 22 and open at 23. Due to the bent-end portions and the direction of flow of the gases in the manifold 2| the individual pipes are subjected to an induction effect which tends to produce a slight vacuum therein. The manifold M is provided, at a suitable point, with a check valve corresponding to check valve 8 of the first embodiment, consisting, in the example illustrated by the drawing, of a valve 30. With this arrangement, the necessity of providing the exhaust pipe of each cylinder with a similar check valve is avoided.

In other respects, the distributing means of the respective cylinders are similar to those shown by Fig. 1. In the interest of simplicity these are not shown in Fig. 2. It will be readily understood that, when one of the four cylinders is in a position near the end of its charging stroke and its exhaust port 6 has been uncovered, the suction produced in the manifold 2| and the individual exhaust pipe of the cylinder being charged by the cylinder which is in the exhaust stroke facilitates this charging in a substantially similar manner as above explained in connection with the embodiment of the invention shown in Fig. 1 of the drawing.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efilcient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the appended claims.

What I claim is:

1. Method of operating a four cycle internal combustion engine provided with a rotary distributor valve having inlet and exhaust means for preventing subjection of the valve to excessive temperature of exhaust gas and for increasing the amount of fresh charge charged into the cylinder of the engine during the charging stroke, said method comprising passing a part of the hot exhaust gases of a cylinder toward the end of the working stroke into an auxiliary chamber from a port located near the bottom position of the upper surface of the piston, said port, being uncovered-before the exhaust means of the distributor valve, closing said port during the exhaust stroke, creating a partial vacuum in said auxiliary chamber and putting said chamber in communication with the interior of the cylinder for an extremely short time through said port at the end of the suction stroke of the piston to withdraw additional burned gas and facilitate charging the cylinder with fresh gas through the inlet means of the distributor valve.

2. Method of operating a four cycle internal combustion engine provided with a rotary dlstributor valve having inlet and exhaust means for preventing subjection of the valve to excessive temperature of exhaust gas and for increasing the amount of fresh charge charged into the cylinder of the engine during the charging stroke, said method comprising passing a part of the hot exhaust gases of a cylinder toward the end of the working stroke into an auxiliary chamber from a port located near the bottom position of the upper surface of the piston, said port being uncovered before the exhaust means of thedlstributor valve, closing said port during the exhaust stroke, creating a partial vacuum in said auxiliary chamber by cooling the gases therein during the exhaust stroke and the major portions of the charging stroke of the piston, opening communication between said auxiliary chamber and the interior of the cylinder for a short period toward the end of the charging stroke, to suck out additional stratifled burned gas and to draw additional fresh charge into the cylinder through the inlet means of the distributor.

3. The method of operating a multi-cylinder, foun stroke cycle internal combustion engine, each cylinder of which has a rotary distributor valve provided with inlet and exhaust means, and each cylinder having a supplementary exhaust port in its wall above but near the lowest position of the upper surface of its piston, said supplementary exhaust ports opening into auxiliary chambers, and a common exhaust pipe into which said chambers open in the direction of flow of the exhaust gases in said pipe for preventing excessive heating of the distributor valve by hot exhaust gases and increasing the amount of fresh charge charged into the cylinders, said method comprising passing part of the exhaust gases out of the cylinders through said supplementary exhaust ports to said auxiliary chambers when the pistons are near their lower positions in the working strokes before opening the exhaust means of the distributor valves, opening the exhaust means of the distributor valves during the exhaust strokes of the pistons, producing partial vacuum in said auxiliary chambers during the exhaust and major portion of the charging strokes of the respective portions by the induction effect of the exhaust gases of the other cylinders flowing in the exhaust pipe, opening the cylinders to their corresponding auxiliary chambers for extremely short periods near the end of the charging strokes so that the vacuum in said auxiliary chambers will suck out stratified burnt gases from the cylinders and draw additional fresh charge thereinto.

4. In a four stroke cycle internal combustion engine comprising a. cylinder having a reciprocatory piston therein, a rotary distributing valve having intake and exhaust means therein, located at the upper endof the cylinder, and said cylinder having an auxiliary exhaust port located in its side wall at a point immediately above the upper face of the piston when in its lowest position, an exhaust chamber for receiving the exhaust gases passing out of said auxiliary exhaust port; means for operating the distributing valve to open the exhaust means thereof after the exhaust gases have passed out of the auxiliary exhaust port to such extent as amazes to reduce the pressure in the cylinder to substantially atmospheric pressure, whereby the exhaust means of the distributor valve receives only expanded and cooled exhaust gases, means for creating a partial vacuum in said exhaust chamber during the exhaust stroke and major portion of the charging stroke, whereby additional stratified burned gases are sucked out oi the cylinder toward the end of the charging stroke by the vacuum in the exhaust chamber and additional fresh charge is sucked into the 5 cylinder to replace said additional burned gases.

MARCEL ACHILLE VIOLET.