DE3322121A1 - Two-stroke internal combustion engine - Google Patents

Abstract

A two-stroke engine contains an inlet and scavenging valve in the cylinder head together with a fuel injection system, a circulating pressurised lubrication system and a fan or a turbocharger which supports air charging of the cylinder and scavenging of the exhaust gases. The piston head is dome-shaped, one side being curved downwards onto the outlet slot, which is led through the wall of the cylinder above the bottom dead centre position of the piston head. The outlet slot is inclined outwards and downwards, largely following the inclination of the piston, in order to ease the flow of exhaust gases through there aided by the scavenging air, which enters through the inlet and scavenging valve. The valve is actuated by a cam, which is fitted on a camshaft on the cylinder head, which shaft is in turn connected to the crank shaft. The size of the cam is selected in such a way that the opening, closing and the opening duration of the valve is controlled, the valve being opened over about 140 DEG and the piston controlling the opening of the outlet slot over about 130 DEG , so that there is an overlap of about 5 DEG at each end of the opening of the outlet slot. It is worth noting that the oil scraper ring always remains below the outlet slot, in order to prevent lubricating oil from being able to escape through the outlet slot.

Description

Two-stroke internal combustion engine

The invention relates to a method for operating a high-speed vehicle and a high torque generating two-stroke multi-cylinder with gasoline or diesel powered internal combustion engine / in which an air blower or a series-connected turbocharger combination is used and the inner ones moving parts have a new design, and particularly relates to the design of the Purge valves created by the relatively large surface area of the cams of a camshaft and associated devices , which are all arranged in the cylinder head, can be opened and closed. Significant is also the piston arrangement, which is a new design feature having. A pressurized circulating lubrication system is used to maintain the essentials and to lubricate critical moving parts, making the invention a powerful device is made. The design and location of the exhaust ports in each cylinder also provide for the best possible engine operation.

The object of the invention is to avoid the many disadvantages, limitations, difficulties and poor performance of most two-stroke engines, especially those with pressure lubrication. In addition, flushing valves are to be created that are opened and closed by special cams, which have a relatively large contact area for a longer duration of the valve opening period. the

Valves and associated devices should be built into the cylinder head. Furthermore, a piston assembly be created, which reduces pressure lubrication problems and gets them under control. Farther the piston assembly, flush valves and associated devices are designed to conform to the shape and the arrangement of the exhaust ports in each cylinder so designed and an air blower applied that it leads overall to comparatively cleaner exhaust emission values. Furthermore should A motor can be created that has high torque and high speeds by being less agile Parts and a compact structure produced. In addition, the air blower assembly is intended to be an impeller of the blade type (scoop type) and have a compressor rotor, which together on a common shaft are attached, which is mounted on ball bearings and by means of a gear or a pulley can be driven.

This object is achieved using the features of the characterizing part of the claim 1 solved.

The subject of the invention is thus a supercharged two-stroke multi-cylinder internal combustion engine with in-line or V-shaped arrangement and a pressure lubrication system, which is characterized by the combination following features: a cylinder block with cylinder bores formed therein, a cylinder head on the upper end of the cylinder bores, which closes them, and a combustion chamber at the upper end of each Cylinder bore delimits a piston assembly in each bore that has a piston with a domed shape Bottom and a reciprocating connecting rod operatively connected to the piston

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the same between the top dead center and the has bottom dead center, a crankshaft which is rotatably mounted in the lower part of the block, the connecting rods are operatively connected to the crankshaft and an oil pan is the lower The end of the cylinder bores and the crankshaft encloses “and wherein the cylinder head is a camshaft has, which is rotatably mounted thereon and is in operative connection with the crankshaft, at least one intake and purge valve attached to the cylinder head and connected to the combustion chamber each cylinder bore is in operative connection, a rocker arm, which is movably attached to the cylinder head and one end engages the inlet and purge valve, a cam for each Rocker arm, which is formed on the camshaft, and in operative connection with the other end of the rocker arm stands, with the cam having a relatively large area of contact with the rocker arm for controlling the opening, closing and opening times of the inlet and purge valve and one Have outlet slot, which is arranged in the lower region of the cylinder walls of the cylinder bores, is guided downwards and outwards through the cylinder walls and from the reciprocating piston, which moves past it, is covered and uncovered.

Embodiments of the invention are shown in the drawings and will be described below described in more detail. It shows;

Fig. 1 is a schematic, partially sectioned side view of a cylinder and a Piston assembly, the piston in

last part of the working stroke at already

Ι partially open flush valve or

Exhaust valve is shown

FIG. 2 shows a representation similar to FIG. 1, but with the piston in the bottom dead

point is shown with the inlet valve fully open,

FIG. 3 shows a representation similar to FIG. 1,. however, the outlet slot through the

Piston covered at the beginning of the compression stroke with the inlet valve still partially open is shown

FIG. 4 shows a representation similar to FIG. 1, wherein

however the piston is shown in the top dead center of its compression stroke,

Fig. 5 is a broken away cross-sectional view of the piston and connecting rod assembly

alone,

Fig. 6 is a schematic, partially sectioned side view of a turbocharger, which with is connected to the engine,

FIG. 7 shows a representation similar to FIG. 6,

however, a V-arrangement is shown,

Fig. 8 is a broken away cross-sectional view

a preferred air blower design,

9 is a view from the left in FIGS. 8 and 8

Figure 10 is an example of the valve and slot diagram of the engine.

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In the drawings, the same reference numerals indicate corresponding parts in the different ones Figures designated.

Reference is first made to Figures 1 to 4, in which the reference numeral 10 denotes a cylinder generally, the one Cylinder wall 11, cooling water channels 12 formed therein, and a cylinder head assembly 13, attached to the top of the cylinder by conventional means (not shown).

A valve housing 14 protrudes over the cylinder head and is also by conventional means that are not are shown attached.

A piston assembly reciprocates in the cylinder, the piston assembly being indicated generally by the reference numeral 15 and a piston as a whole is denoted by 16 and a connecting rod, which is denoted as a whole by 17, has of details of which are described below.

An outlet slot 18 is formed through the wall of cylinder 11 on one side thereof, the outlet slot preferably being rectangular in shape and extending downwardly and outwardly through the wall as clearly shown in Figures 1-4.
30th

An exhaust pipe 19 leading to an exhaust manifold 20 (see Fig. 6) leads to the outlet slot on "its outside by a flange 21 and screws 22, and this outlet pipe 19 extends outward and downward at an angle of inclination angle of inclination similar to that of the outlet slot

through the cylinder wall 11 to facilitate the exit of the exhaust gases, as will be described below .

At least one, and preferably two or more, air intake and purge valves 23 are provided in the cylinder head 13, which normally sit on valve seats 24 and are held thereon by valve springs 25 at the upper ends 26 of the valve stems which pass through valve guides 27 in the head 13 on a conventional manner attack.

Preferably, these valves are operated by an overhead camshaft 28 which is on a

conventional manner (not shown) is rotatably mounted and with the crankshaft (not shown), which is also conventional, is in operative connection.
20th

The cams 29 of the camshaft, however, are designed with a relatively large contact surface 30A in order to the opening time of the air inlet valves 33 and also the time at which they are opened and closed ' be to control.

The cams 29 engage rocker arms or rocker arms 30, one end of which is attached to rocker arm bearings 31 are pivotally mounted and at the upper 'ends 26 of the valve stems with the other ends Attack 32A in a conventional manner.

In Figures 1 to 4, a total of 32 designated air blower arrangement is provided, the is operably connected to the engine in a conventional manner by the air intake valve

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to supply air under superatmospheric pressure via the channels 33, which is connected to an inlet line or may be connected to an intake manifold when a plurality of pistons and cylinders are used.

Details of the preferred embodiment of the Air blower assemblies are shown in Figures 3 and 9 and comprise a cylindrical housing 34, in which a fan blade assembly, the

1-0 is designated as a whole by 35, on a shaft is rotatably mounted, which is supported on bearings 37 and from the motor by means of a gear 38 or a toothed belt (not shown) is driven, which or with the camshaft on a conventional manner is drivingly connected by means of a timing chain or a toothed belt.

The fan has the aforesaid fan assembly 35 with an outer group of impeller blades 39 and an inner group of screw or Compressor blades 40 on. By rotating the fan assembly in the direction of arrow 41, Air is drawn in through the central inlet 42 in the center of the front wall of the housing, compressed and ejected through the outlet end 43 which is operatively connected to the air inlet valves 23, as described below.

Reference is made to the piston arrangement, <3, ie is shown in detail in FIG. 5. The piston is preferably made from an aluminum alloy and has a piston crown 44, a piston crown cap 45 and an outer, cylindrical jacket part 46.
35

The piston cap 45 is dome-shaped., As indicated by the

Reference numeral 47 is shown and is convexly curved, the one going to the outlet slot 18 Side of the cap 48 is curved down to a point 48 which is lower than the connection of the Cap with the bottom on the opposite side, which is represented by the reference numeral 50, so that the tip 51 of the dome is from the vertical centerline of the piston toward the side 50 is offset that of the lower side 49 on the outlet slot side of the cylinder in the assembled State is diametrically opposite.

This facilitates the flow of exhaust gases from the combustion chamber 52, taking over the fan assembly 32 incoming air helps. ·

A pair of opposing piston bosses 53 are in the wall of the piston in a conventional manner Formed way, and a piston pin 54 is mounted in these eyes and is also in the The piston pin end 55 of the connecting rod 17 is supported.

It is desirable to seal the outer ends of the eyes 53 in order to prevent lubricating oil from getting exits through it, and for this purpose a connecting rod or pin 56 extends freely through the Piston pin 54, which is hollow, and is e.g. B. attached by brazing to two concave sealing or sealing caps 57, each of which is somewhat within of the respective outer end 58 of the piston pin bosses of the piston is arranged, as can be seen from FIG see is.

A pair or more of piston rings 59 are seated in piston ring grooves 60 around the piston adjacent to it upper end of its bottom and an oil drain

strip ring 61 is inserted into an annular groove 62; which is arranged next to the lower end of the skirt of the piston, with oil return window 63 are formed in the shell at the lower end of the groove in a conventional manner.

What matters is the fact that the oil control ring always remains below the lower side 18A of the outlet slot when the piston is in the upper The dead center position is as shown in FIG.

The arrangement of the outlet slot 18 is such that it extends downward and outward on the walls of the The cylinder inclines, and the adjoining exhaust pipe is preferably rectangular in shape and may be provided with one or more vertical rods 64 to support the piston rings at the outlet port to prevent them from getting on the edges of the walls that delimit the slot, caught.

Reference is made to FIGS. 1 to 4 to describe the mode of operation up to this point.

in Fig. 1 the piston is approaching the lower end of the power stroke and the purge valve is just beginning to open up. In Fig. 2 the piston is at the lower end of the working stroke, with the outlet slot 18 is exposed and air passing through the now fully open purge or inlet valve, is supplied in sufficient quantity from the fan assembly 32 to pass the exhaust gases through the Completely flush out the outlet slot, which is due to the common angle of the piston head cap on this Place, the downwardly inclined outlet slot 18 and the outlet pipe 19 is facilitated.

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In this position the piston is in the bottom dead center, and in Fig. 3 it begins to move up on the compression stroke, covering the outlet port 18, although that Purge valve is still slightly open to ensure that there is a full charge of air in the combustion chamber 52 is fed.

The purge or inlet valve 23 now closes as the piston continues on the compression stroke to move up to the top dead center position, which is shown in FIG. When the piston is in this position, it will be seen that the aforementioned oil control ring 61 is always below the lower edge 18A of the outlet slot remains, so that lubricating oil cannot escape through this slot.

Within a few degrees when the piston reaches top dead center of its travel, as in FIG. 4 As shown, a fuel spray is provided over a conventional fuel injection assembly 65 injected, which is due to the highly compressed air between the cap of the dome-shaped piston head and ignite the combustion chamber of the cylinder head in a conventional manner, the Flush valve 23 is completely closed at this point. The mixture of ignited fuel and highly compressed air expands and pushes the moving piston down, wherein he executes the work or expansion stroke in the position shown in Fig. 1, and the The work cycle repeats itself over and over again.

It should be emphasized that the flushing valves 23 have a relatively large diameter in order to ensure that

that the air supplied to the cylinders 52 is sufficient to completely purge and charge the cylinders each time the piston reaches the bottom of its stroke.
5

It should also be emphasized that the flushing valves 23 are opened and closed at the correct timing with the piston movement. To this To achieve, the cams 29 of the camshaft 29 have a relatively large contact area 30A, and they are designed so that they the duration of the opening and closing of the flush valves 23 with respect to the Timing the piston movement correctly. The flushing valves 23, the rocker arms 30 and the cams 29 of the camshaft 28 mechanically contact each other and are all assembled on the cylinder head. The camshaft 28 is from the crankshaft by means of gears and a chain or toothed belt in a conventional manner Mechanically driven way.

Reference is made to the novel construction of the piston assembly shown in detail in FIG is. The piston is preferably made of an aluminum alloy and has a Piston head 44, a piston head cap and an outer cylindrical shell part 46.

As previously mentioned, the piston assembly shown in broken away form in Fig. 5 is Another important feature as it affects and alleviates lube oil problems especially when a pressure lubrication system is used on a two-stroke engine. The new design features of the piston assembly are as follows: the bottom 45 is dome-shaped to allow the flow of scavenging gases to facilitate a pair of piston rings 59

and a few. Sealing caps 57 installed at both ends of the piston bosses. For reasons For operational safety, these caps 57 are attached to a pin 56 by brazing, . which extends freely through the piston pin 54 which is hollow. The sealing caps 57 are installed at each extreme end of the piston bosses 58 to prevent lubricating oil from passing through can emerge.

Another important feature of the piston assembly is the oil control ring 61, which is located near the lower end of the piston skirt is arranged together with oil return holes 63, the task of which is to prevent that lubricating oil can flow off to the outlet slots 18 and that the oil scraper 61 always remains under the lower side 18A of the exhaust port when the piston is in the top dead center position its stroke is.

The outlet slot 18 is in the side of the cylinder wall next to the bottom dead center position of the piston arranged, sloping downward and outward, and covered and released by the piston to facilitate the flow of exhaust gases into the environment.

As mentioned above, the invention is suitable for single-cylinder or multi-cylinder engines with in-line or V-shaped arrangement, which are shown schematically in Figures 6 and 7, respectively.

It should be emphasized that the fan assembly 32 can be used with all cylinder arrangements .35, or alternatively one in-line switched turbocharger and air blower combination

can be used, as shown schematically in FIG. 7, in which it is designated as a whole by 66.

Finally, reference is made to Fig. 10, the Figure 10 shows a valve and slot diagram.

The width of the cams 30A is chosen so that the inlet and flushing valve at about 105 ° to 110 ° after top dead center and opens at about Closes 70 ° after bottom dead center, so that it remains open over about 140 °.

The arrangement of the outlet slot with respect to the The piston is such that the piston exits the outlet slot at about 115 ° after top dead center releases and covers or closes at about 65 ° after bottom dead center, so that the outlet slot remains uncovered over about 130 °. The relationship between the opening of the outlet port and the opening of the inlet and flushing valve is such that there is an overlap of about 5 ° at each end, when the inlet and flush valve is opened at about 5 ° before the release of the outlet slit and remains open for about 5 ° after the outlet slot is covered or closed.

This controls the opening and closing and the opening time of the inlet and flushing valve, wherein the piston and the location of the outlet slot are the opening, closing and opening duration control of the outlet slot.

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Claims (12)

PATENT ADVOCATE
OR. RICHARD KNEISSL- "" :: Widsnmayerstr, 46 ^ "^ ^ ^ _ ^ D-8000 MUNICH 22 ** "* TeL 089/295125 I Ü. Jun / 1983 Note from Antonio Ancheta, Winnipeg, Manitoba / Canada Two-stroke internal combustion engine Claims / 1 J Supercharged two-stroke multi-cylinder internal combustion engine with an in-line or V-shaped arrangement and a pressure lubrication system, geke η η is characterized by the combination of the following features: a cylinder bracket with cylinder bores formed in it, a cylinder head at the upper end of the cylinder bores, which closes them, and a combustion chamber Bounded at the top of each cylinder bore, a piston assembly in each bore, which has a piston with a dome-shaped bottom and a connecting rod operatively connected to the piston for reciprocating the same between a top dead center and a bottom dead center, a crankshaft, which in the lower part of the cylinder block is rotatably mounted, the connecting rods being operatively connected to the crankshaft and an oil pan enclosing the lower end of the cylinder bores and the crankshaft, the cylinder head having a camshaft attached thereto is rotatably mounted and is in operative connection with the crankshaft, at least one inlet and purge valve attached to the cylinder head and with the combustion chamber of each cylinder bore is in operative connection, a rocker arm which is movably attached to the cylinder head and engages with one end on the inlet and flush valve, a cam for each rocker arm that is arranged on the camshaft and in operative connection with the other end of the rocker arm stands, with the cam having a relatively large area of contact with the rocker arm for controlling the opening, closing and opening times of the inlet and flushing valve and have an outlet slot, "the one in the lower area the cylinder walls of the cylinder bores is arranged, downward and outward through the Cylinder walls and by the reciprocating piston moving past them is revealed and uncovered. 2. Internal combustion engine according to claim 1, characterized in that the cam is the Inlet and purge valve at about 110 ° past the top Dead center opens and closes at about 70 ° after bottom dead center and thereby the inlet and Keeps the flush valve open for about 140 ° / 3. Internal combustion engine according to claim 1 or 2, d a characterized in that the piston reveals the outlet slot at about 115 ° after top dead center and at about 65 ° closes after bottom dead center, so that the outlet slot opens over about 130 ° is. 4. Internal combustion engine according to claim 3 / characterized characterized in that the overlap between the inlet and flush valve and the Äuslaßschlitz is about 10 °, with the inlet and flushing valve about 5 ° before the opening of the outlet slot opens and closes about 5 ° after closing the outlet slit. 5. Internal combustion engine according to one of the preceding claims, characterized in that that the piston assembly means for controlling and reducing the loss of lubricating oil by flowing past includes, which have the piston with a dome-shaped piston crown cap, a piston skirt extending from there, piston pin bosses formed in the skirt below the dome-shaped bottom, sealing caps, which are located in the outer end of each piston pin boss to prevent oil leakage by flowing past them to prevent a piston pin that is mounted in the piston pin boss and the connecting rod with the piston operatively connects at least two piston rings that in spaced apart and parallel grooves in the bottom of the piston Are arranged over the piston pin bosses, at least one oil control ring, which is in an annular Groove is arranged around the skirt of the piston under the piston pin bosses, 30. - and drainage holes going through the jacket from the groove to prevent the loss of lubricating oil to reduce through the outlet slot, with the oil control ring always below the lowest The edge of the outlet slot remains when the piston is at top dead center. .- :: * :::: -;:.; 33ZZ I Z ι 6. Internal combustion engine according to one of the preceding claims / characterized in, that the outlet slot has a rectangular shape and downward and outward on the lower side of the cylinder wall is inclined, with the outlet slot of the piston closed and uncovered when it is between top dead center and bottom dead center in the cylinder bore emotional. 7. Internal combustion engine according to one of the preceding claims, characterized by an air blower part that works with the Engine is operatively connected and has an air inlet port and an air outlet, wherein the air outlet is operatively connected to the inlet and purge valve to allow sufficient air for loading and flushing the cylinder. 8. Internal combustion engine according to one of claims 1 to 6, characterized by a Turbocharger and an air blower connected in series, the air blower through the Exhaust gases of the engine is operated, and wherein the turbocharger and the air blower with the intake and purge valves are operatively connected to provide enough air to load and purge the cylinders to feed. 9. Internal combustion engine according to claim 5, characterized in that the piston pin is hollow and mounted in the piston pin bosses and a retaining pin between the locking caps is attached, which runs freely through the hollow piston pin and the sealing caps in a layer with a small distance inwards to the S .. ^: .. ¹ ' ^: . ^:: .J ' ^: .. ^: · ^: ο ο ZZi ζ I holds the outer ends of the piston pin bosses. 10. Internal combustion engine according to one of the preceding claims, characterized by a pressure circulating lubrication system in which lubricating oil stored in the oil pan and all essential moving parts by means of the pressure lubricant pump which is driven by the crankshaft via gears, the Lubrication system has a micro-oil filter to ensure that the essential moving Parts are always supplied with clean oil. 11. Internal combustion engine according to one of the preceding Claims, characterized in that the cam has an outer contact surface section having that with the inlet. and flush valve is engageable and extends over an angle of rotation of approximately 140 °, in order to thereby open and close the valve and its opening and closing times as a function to control of the size of the piston movement when the Äuslaßschlitz of the piston and is uncovered, with the exhaust slot uncovered over about 130 ° of crankshaft rotation and is covered over about 230 °. 12. Internal combustion engine according to one of the preceding Claims, characterized in that the gasoline by means of gasoline engines a fuel injection system or a Fuel injector attached to the Engine is screwed on, is injected, the Kraf tstoff injection device a metered amount of fuel in each inlet / flush valve opening of each cylinder at the appropriate point in time Dependence on the size of the piston movement an injected and where the fuel at the valve opening each cylinder 10 ° prior to closing each intake / purge valve on the compression stroke is injected.