US2618249A - Two-cycle crankcase compression engine - Google Patents

Description

.Nov. 18, 1952 H. TEEGEN TWO-CYCLE CRANKCASE COMPRESSION ENGINE 2 SHEETS-SHEET 1 Filed April l2, 1950 Patented Nov. 18, 1952 TWO-CYCLE CRANKCASE COMPRESSION ENGINE Hermann Teegen, Bielefeld, Germany Application April 12, 1950, Serial No. 155,386 In Germany April 25, 1949 (Cl. 12S-48) 6 Claims.

The invention relates to a new design and a respective equipment for the operation ofl twostroke internal combustion engines.

There are conventional designs for the operation of' two-stroke internal combustion engines, applying highlyv volatile fuels, a comparatively lowv compression and electrical ignition, for instance ignition plugs. Furthermore, we know two-stroke internal combustion engines working with fuels of difficult volatility, the so-called diesel fuels. For operation, air is sucked in and pressed into the combustion chamber, where it is compressed to a comparatively high degree, at the end of which process the fuel is injected through nozzles. For this purpose it is necessary to use special fuel pumps which press the fuel under high pressure into the compressed air.

The subject of our invention, however, is a third new design characterized in the way that fuel and air are carried directly into the crank case. The parts of the engine moving in the crank case function as atomizers of the fuel. The mixture of fuel and air passes from the crank case into the combustion chamber. There it is brought to self-ignition by a suflciently high compression. The engines working according to this design, in comparison with those internal combustion engines working according to the abovementioned two conventional designs, shcw the advantage that, the necessary amount of ccmpression having been reached, self-ignition will take place in all parts of the compression chamber at almost the same time. The designs applying electrical ignition make the ignition start from the spark plug as ignition point and expand from there globularly to all parts of the combustion chamber. In engines of the diesel principle the combustion starts locally from the fuel injection nozzle and stretches temporally over the period of the injection process. The well-.known motor knocking of the conventional typescaused by superimposition of pressure Waves isv entirely avoided by the design here claimed, asv the4 ignitionI will` take place simultaneously in all Darts of the, combustion chamber after the necessary compression has been reached.

When operating according to our invention, it is of advantage to let the fuel-air mixture, on its Way'from crank case to combustion chamber, pass along the piston in close touch with its surface. The warming ofv the fuel-air mixture is continued on its way to the. combustion chamber by means off heat exchange, on the other hand the piston ispermanently cooledin consequence 2 whereof the piston' Will never become toc` and will never jam in the cylinder.

It has already been suggested to alterthe,A compression in the conventional two-stroke4 internal Combustion engines by provision Off an axially shiftable cylinder bottom. According to the new design a way is shown in which, by alteration of the compression, the moment of ignition and simultaneously the control times of the engine can be regulated.

Another improvement of design and equipment can in certain cases be reached by additionally providing an atomizer before the inlet pointsof fuel and air into the crank case. It is possible, besides, to provide additional means of a better diffusion of the fuel, as described below.

As mentioned before, an alteration of the control times of the engine can be achieved simultaneously with the alterationl of; the compression. This can be managed by Way of special control elements, or the alteration cfvr the control times can be simultaneously effected by the regulating means of the alteration of the compress1on.

For the purpose of altering the compression, an intermediate part may be inserted betweenl the piston and the cylinder block, which for instance has the shape of a cylinder liner shiftable with regard to the piston and provided with special inlet, outlet, and recess ports. The recesses for the transportation of the fuel-air mixture from the crank case to the combustion chamber may be arranged in the cylinder liner and shaped like spatiallybent curves. On the one hand this results in a specially directed transportation of the fuel-air mixture into the combustion chamber. On the other hand it is of advantage to keep the recesses totally or partly open vto the inside of the cylinder for the purpose of h'eat exchange between piston and fuel-air mixture. In their spatial curvature the recesses stretch over an utmost possible part of the cylinder circumference.

Finally the fuel and the air, oronly' one of them, can be introduced through warmed parts of the engine. block, so that a prewarmng will take place.

The invention finally relates to thev arrangement and development of an additional atomizer for the air and the fuel. According to the invention, the operating pcsitions of the atomizer in agreement with the opening process are arranged in ,series` 1ike this: 11o-load., partial-load, full-load, and starting position.

Warm

' may be used for this purpose. y for instance may beapplied. In order to prevent Fig. 4 shows a cross-section through Fig. '1'

along section line a-b;

Fig. 5 shows a longitudinal section of the cylinder liner used for the alteration of the compression;

Fig. 6 shows a left-hand sde-view-uponrthe cylinder liner as represented in Fig. 5;

Fig. '7 shows a side-view of the adjusting part to which the cylinder liner is attached: v

Fig. 8 shows the same adjusting part in view from below; Y Y

Fig. 9' shows the element for the introduction of fuel and air, in the final position;

Fig. 10 shows the same element in the starting position for the engine.

I is the cylinder block, 2 the piston with the connecting rod 3 on the crank pin 4 of the crankshaft 5 6 is the crank case. The cylinder block I has the inlet port l for the fuel and the air, and the outlet port 8 for the exhaust gases. Between the cylinder block I and the piston 2 is inserted a cylinder` liner 9. It is axially shiftable in the cylinder block I. Bythe over-pressure in the combustion chamber I0 it is pressed outwards (in the example shown, upwards) and is kept in a definite position as to the piston by a stop devcedescribed hereinafter. The cylinder liner 9 has for instance the shape represented in Figs. 5 and 6. It isprovided with an inlet port II for the air and the fuel, with an outlet port I2 for the exhaust' gasesQand with recesses I3 for the passing-over of the fuel-air mixture, compressed in the crank case, to the combustion chamber il). There is a parallel function of the inlet port II with the inlet Vport 'I in thev cylinder block on the one hand, and'of the outlet port I2 with the outlet p'ort 8 in the cylinder block I on' the other hand.

' The piston passes with its bottom over' the ports I2 and 8 respectively; with its rear end it passes over the inlet ports 'I and I I. In order to make an alteration of the combustion chamber lli and thus of the compression possible to ones liking, the liner 9, as mentioned before, is axially shiftable. A cam plate I 4 is xed at its upper end, with two equal cams I5 displaced to each other by 180 degrees. The cam plate I4 is solidly inserted in the cylinder liner 9. lBy the over-pressure in the interior of the cylinder liner 9, i. e. in the combustion cham- Yber I 0, the liner, which, moreover, is secured against rotation by a wedge (not shown in the drawings) or something of the kind, vis pressed against an adjusting part I6. 'I'he adjusting part I6 is rotatable about its axis and has. two stops I'I functioning together with the cams I5. Cam I5 leans against these stopsI'I which, the

` adjusting part I5 being turned, will wander in anangle range of about 120 degrees. The adjusting part I6 can be turned in this'angle range from without. Any of the conventional means A Bowd en"wire the adjusting part I6 from being pressed to the 4 outside, it is made to lean with its front surface against a closing disc I8 which is attached to the upper end of an extended part of the block I9.

The introduction of fuel and air can, as proved by the operation of the engines, take place immediately through the port l. At the upper dead center position of the piston 2, the fuel and the air enter into the crank case 6, in which a partial vacuum was produced at the preceding active stroke. While going downwards into the lower dead center position, the piston 2 passes with its bottom over the upper ends of the recesses I3, so that the fuel atomized in the crank case 5 and the precompressed and the preheated fuel-air mixture can enter into the combustion chamber I. The recesses I3, as is shown in Figs. 5 and 6, stretch over an utmost possible range of the cylinder liner 9. 'I'hus the fuel-air mixture to a large extent comes in contact with the pist0n 2. The fuel-air mixture, on its way through the' recesses I3, in result of heat exchange is warmed by the piston jacket 2. At the same time, Vice Versa, the piston 2 is permanently cooled. At the next upward stroke'of the piston, the fuel-air mixture in the combustion chamber lil is compressed to such a degree as to let it come to self-ignition. Then the piston 2 goes down again. According to the two-stroke principle, every upward stroke of the pistoni leads to the compression, and every downward stroke of the piston 2 to the combustion of the fuel-air mixture.

During this process the cylinder liner 2 with the cams I5 leans permanently against the stops f' I 'I of the adjusting part I5, as the pressure prevailing in the combustion chamber even during the downward stroke of the piston urges the liner 2 upward and will raise it from a lower position when an adjustment of the part I5 permits such shift of the liner. According to the respective adjustment of the adjusting part I6 the compression can be regulated at ones liking with regard to the starting process, the no-load or the full-load position. The cams I5 show an essential rise in the no-load range, so that Ya slight turn in the starting phase may lead vto great changes of a low compression, while in the working range proper the cams I5 show a ilatter course, so that in the full-load range the compression may be more nely regulated; Y In the starting phase the compressionat rs is reduced, but then greatly raised. As soon as the engine is set in motion, the compression, according to the operating conditions, can be regulated by a respective turning of the adjustin part I6.

With the adjustment of the compressiony by the cylinder liner 9 is associated a simultaneous alteration of the control times, as the inlet ports I I and I2 and, furthermore, the recesses I3 are at once axially shifted. These shiftings vtake place in accordance with the expected increase of output of the engine. It is also possible to move the cylinder liner 9 and the control ports I I and I2 separately and, byv appropriate Coupling parts, to transmit'the desired motion from the adjusting partl upon the control elementsY I I, I2,I3.

In Fig. 3 it is shown, besides, how the air, @before entering into the crank case 6, can be introduced through an Yair-'inlet port 20,- and the fuel, respectively, through an inlet port -2I. 'I'hese ports in the shape of recessespass through the cylinder block I, thus permitting the fuel and the air to be pre-warmed. The recesses-'2U an'd 2l can also be made to pass along the cylinder block l. The chief thing is only that the fuel, or the air, or both simultaneously, must be warmed.

In Figs. 9 and 10, finally it is shown how the fuel and the air are regulated by a special atomizer whi-ch can be inserted in front of the inlet port l of the engine. again is the recess for air admission, and 2l the recess for fuel admission. In the nozzle 22 there is, axially shiftable a spindle 23, which is solidly attached to an axially shiftable piston 2&3. The piston 2d is axially shifted by a rod device 25, and passed into the closing position by a spring 2t (Fig. 9). Moreover, the piston 24 has an air-passageway 27, which can make the air-inlet port 29 communicate with the mixing recess 28. The mixing recess 28 leads to the inlet port 7 of the cylinder block. Besides, the cylinder chamber 29, in which the piston 2d shifts, communicates with the mixing recess 28 by means of an intermediate recess 30.

The operation of this atomizer is as follows. When the piston 2li is in the position acco cling to Fig. 9, the fuel admission and the air adn mission are interrupted. When the piston is moved outward in the direction of the arrow C, contrary to the effect of the spring 25, the spindle 23 releases the fuel supply more and more. Furthermore, a growing amount of air can pass to the mixing recess 28 by way of the air-inlet port 20 through the perforation 2l. In this manner the full-load position is reached by way of the no-load position. For the purpose of starting, the piston 2li must be entirely pulled out to the right hand according to the arrow C. Thus only a slight amount of air can pass from the recess 20 to the mixing recess 2B, while the spindle 23 releases the fuel supply to the largest extent. So a fuel-air mixture enriched with fuel enters into the engine for the purpose of starting.

Thus the subject of the invention shows the followingr succession of the various operating positions: no-load, partial-load, full-load, and starting position. The latter simplifies the starting operation of the engine extremely. After the engine has been set in motion, the piston 24, by Way of the full-load position, must be returned into the desired no-load position. For the operation of the rod device according to the direction of the arrow C any kinds of operating elements may be used, for instance a Bowden wire. Finally, it is possible to insert elements like sieves, bafe plates 3l, favouring the tearing of the fuel, between the fuel recess 38 and the cylinder block l or the crank case 6. It makes no difference whether these sieves 3l are placed more towards the fuel-inlet side or more towards the crank case.

What I claim is:

1. In a two-stroke internal combustion engine with a self-ignition including a crank case and a piston, a headed cylinder stationary with respect to said crank case, a cylindrical liner in which said piston is reciprocable, said liner including a closed head and being axially shiftable in said cylinder, and a cam device including two members, the rst one of said members being movably held in said cylinder head and adjustable from the outside, the second member being secured to the head of said liner, one of said members having a cam face engaged by said other member constituting a cam follower, and said cam face being non-uniformally sloped so as to cause a non-uniform axial shift of said liner upon a uniform adjustment movement of said first member.

2. A device as claimed in claim 1, said cam face being,r sloped more steeply in that portion which is engaged by the other member when the liner is near its position closest to the cylinder head, than in the portion engaged when the liner is near an opposite end position.

3. A device as claimed in claim 1, said rst member being an element rotatable about the axis of said cylinder and including a downward directed eccentric projection, and said second member projecting upwards from said liner and having a cam face engaged by said projection of said first member, one portion of said cam face being more steeply sloped than another portion thereof.

Ll. In a two-stroke engine with self-ignition including a stationary cylinder, a cylindrical liner having a closed head and being axially shiftable in said cylinder and a piston reciprocable in said liner, first means to adjust the position of said liner in said cylinder thereby to vary the combustion chamber, and second means to admit to said engine a combustible mixture adjusted according to the adjusted liner position, said second means comprising a first member in a controlling relationship to an air admission passage, a second member in controlling relationship to a fuel admission passage, and a connection of said members whereby in a first end position of said members both said admission passages are closed, in a second end position of said members said fuel admission passage is fully open and said air admission passage is slightly open, and in an intermediate position said air admission passage is fully open and said fuel admission passage is partly open.

5. A device as claimed in claim Ll, said second means comprising a slide valve controlling said air admission passage, and a needle Valve controlling said fuel aomission passage, means to conduct fuel having passed said needle valve into the current of air having passed said slide valve, and a third passage to admit the fuel-air mixture to said engine.

6. A device as claimed in claim 5, further comprising means partly obstructing the flow of the mixture in said third passage so as to tear up the fuel in said mixture.

HERMANN TEEGEN.

REFERENCES CTED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 808,336 Bogert Dec. 26, 1905 882,401 Melhuish Mar. 17, 1908 943,598 Hovey Dec. 14, 1909 1,125,375 Newton et al Jan. 19, 1915 1,125,376 Newton et al. Jan. 19, 1915 1,195,070 Nelson Aug. 15, 1916 1,289,006 Rowell Dec. 24, 1918 2,583,499 Teegen Jan. 22, 1952 FOREIGN PATENTS Number Country Date 5,100 Great Britain Mar. 1, 1911 129,373 Switzerland Dec. 17, 1928 884,757 France May 8, 1943

Images