DE1003986B - Four-stroke internal combustion engine - Google Patents

Description

Four-stroke internal combustion engine The invention relates to a four-stroke internal combustion engine with charging with at least two working cylinders and aims at an energy-side Improvement of the charging and reloading of such machines.

It is well known that when charging or recharging a four-stroke engine after completion of the intake stroke in the area of the bottom dead center through slots Air compressed in the cylinder wall is pushed into the cylinder, with the reloading air is provided by a compressor. The additional arrangement of a Compressor, the machine is structurally very expensive, and the drive of the compressor In addition, it also requires additional effort on the energy side.

The object of the invention is to remedy these deficiencies by means of improved measures to eliminate when reloading four-stroke internal combustion engines.

In two-stroke internal combustion engines, there is a method of scavenging and loading known from multi-cylinder machines in which the exhaust gases through slots escape and the purge air enters through other slots, which close earlier than the outlet slots, this method being that the after closure air charge escaping from the scavenging air slots through the exhaust slots through the Pressure of the exhaust gases of another cylinder is pushed back again, in which the exhaust of the burnt gases is just beginning. From this basic idea makes the present invention in transfer to four-stroke internal combustion engines so far Use, as well as exhaust gases in each case of a cylinder for charging an associated one other cylinder can be used; however, according to the invention, none of the cylinders are produced Intake air that has penetrated into the exhaust pipe is pushed back again, but rather Fresh air is recharged completely independently of the intake process, which in terms of weight a stronger recharging effect can be achieved than with the known back pressure of the intake air and is also preferably the post-charge air by suitable means is prevented from mixing with the exhaust gases.

The solution according to the invention is that, as with two-stroke internal combustion engines known per se, two cylinders out of phase in the work cycle work together in such a way that alternately exhaust gases of one cylinder in the other cylinder a recharge cause this cylinder connected by a known reload tube are, in order to partially utilize the adiabatic working gradient for the Reloading with the cylinders via provided on the same in the vicinity of the bottom dead center Slots communicating and self-contained, d. H. independent of the usual inlet valve, is filled with fresh air by means of control elements provided on the reloading tube stored in the tube in a rhythm that is coordinated with the control of the slots and alternately pushed over by exhaust gases from one cylinder into the other cylinder whereupon the residual gases present in the pipe in an intermediate cycle phase be pushed out by fresh air entering the same again. The each other Charging cylinders are advantageously 180 ° CA in their firing order offset.

Another feature of the invention is that in the reload tube a known freely movable drive member, e.g. B. in the form of a free-flying Piston, is arranged, which during its back and forth movement between air and the exhaust column is switched. This drive link is in its dead center position in each case for the cylinder that has just been reloaded, namely in such a way that that it alternately exhausts through the slots in the reload tube Exhaust gases in the direction of pressure in front of the air column present in the reload tube after the other Cylinder is moved towards. The fresh air to be brought into the reload tube from the outside can for example be promoted by a fan. Such a fan requires only a relatively small performance and thus a low cost, because the same thing essentially only has to displace the exhaust gases from the reloading tube and thus only low requirements are placed on its print delivery. Advantageously but you can significantly increase the reloading effect if, as already indicated, the controls of the reloading tube can work so that its outlet opening earlier when the inlet port is closed. In this case, with the help of the fan the fresh air stuck or stored in the reloading pipe is placed under overpressure. Instead of a fan, if the design of the crankcase is appropriate also the pumping action of the piston underside of those cylinders are used that a suitable crank offset compared to the working cylinders to be reloaded, z. B. 90 to 270 ° CA, so da.ß their conveying effect temporally with the air requirement of the reloading tube. It is true with valve-controlled Internal combustion engines already known a charging pipe device in which the exhaust gases a cylinder can be used to push over a quantity of fresh air. However is here the loading tube is not connected to a special slot control of the working cylinder, but connected to the usual outlet valve, and the fresh air pushed over is not alternately fed into another cylinder, but into one Receiving container from which they are returned to the same in the corresponding work cycle Cylinder from which the overthrust work was based is returned. These However, the arrangement has the disadvantage that the charging process is not affected by the adiabatic The energy contained in the exhaust is effected and immediately transferred to the charged Cylinder takes place, but that the loading work under the counter pressure of an intermediate cylinder, so, so to speak, with the effect of braking power. Then there is another Load from additional valves on the one switched on in the charging circuit. Intermediate container.

Next, an arrangement for gas engines is known in which the Exhaust gases from a working cylinder via a sliding piston arranged in the exhaust pipe operate a diaphragm pump, through which a gas charge is periodically introduced into the engine cylinders is promoted. This arrangement does not refer to the mutual cooperation the cylinder of four-stroke engines, nor is it used for reloading.

Finally, there is also an arrangement for multi-stage compression has been proposed in gas turbines and reciprocating engines in several compression chambers connected in parallel, the one sucked in in a first compression chamber Air through exhaust gases from a second compression chamber into the first with an increase in pressure is pushed over, with freely flying pistons arranged between the air and gas column could be. Again, it is not about an alternating reloading process, but a gradual increase in pressure of the compression air, which z. B. at a Piston engine has the serious disadvantage that the pistons and the cylinder spaces must be provided unequal size, whereby the mass balance is disturbed.

According to another modified embodiment of the invention can the reloading pipe also by a pipe slide operated by the internal combustion engine be replaced, with the inlet and outlet openings in the valve body and window are arranged in the rotatable part so that they interact with the outlet slots the cylinder controls the gas-air change in the tubular slide for reloading in the same way as with the reload tube described above the case is. If necessary, a free-flight piston can also be arranged in the tubular slide be.

In tabular form, the following work cycles result in chronological order for the subject matter of the invention: Control organs of Motor cylinder I Motor cylinder II reloading tube reloading tube (e.g. valves) A. At the end of the air piston at the end of the suction piston moves Closed expansion stroke is bes is determined by the after-pressure of the exhaust gas a part of the exhaust gas loading slots air from the engine cylinder I from the- into the reload tube after the engine cycle pushed pushed linder II and presses the Reload air through the Slots of cylinder II in this one B. Extension stroke Compression stroke Flying piston is located through the inlet control Intake stroke expansion stroke in dead position with motor cy- cle organ of the reloading linder II pipe enters air and displaces the exhaust gas through the outlet control organ of reloading pipe into the exhaust pipe tion C. At the end of the At the end of the expansion piston moves closed suction stroke becomes part of the exhaust pressure the reloading slots of the exhaust gas in the post-engine cylinder II of Air from the reloading robot pushed this away to the engine tube pushed in cylinder I and pushes the recharge air through the slots of the cylinder ders I into this one D. Compression stroke, extension stroke, flying piston is through the inlet control Reload Expansion stroke in dead position in the engine cycle of the cylinder I pipe, air enters and displaces the exhaust gas through the outlet control organ of reloading pipe into the exhaust pipe tion A. to D. Repetition of the work cycles The advantages of the invention are not only evident in the improvement of the recharging as such. There is, for example, another advantage that some of the exhaust gases flow off at the start of the extension stroke, whereby the mean pressure of the extension stroke is reduced.

In the drawing, the subject matter of the invention is shown schematically in several Embodiments shown. Here Fig.l shows or show a four-cylinder four-stroke internal combustion engine, in each case two cylinders assigned to one another by a reloading tube according to of the invention are connected, Fig. 2 is the associated crank angle diagram for the Time of the gas outlet or the simultaneous reloading in the mutually assigned Cylinders, FIGS. 3 to 8, arrangement schemes and crank angle diagrams similar to in Figs. 1 and 2, only for other work cycles and crank positions, Figs. 9 and 10 Arrangement scheme and working diagram similar to Fig. 1, but with the difference that Guide devices are arranged in the reload tube instead of a flying piston, FIG. 11 and Fig. 12 is an arrangement scheme and a working diagram of the same arrangement as in Figs. 9 and 12 10, but with a different work cycle, FIG. 13 shows a connection between the cylinders Reload tube, which is arcuate, FIG. 14 shows an embodiment which the reloading tube is replaced by a tube pusher.

In Fig. 1, the cylinders of a four-cylinder four-stroke internal combustion engine denoted by 1 to 4, while 5 is the reloading tube, each in the work cycle Cylinders 1 and 3 or 2 and 4 offset by 180 ° CA on the exhaust or charging side connects. The reloading tube only considered in the following for reasons of symmetry 5 between the cylinders 1 and 3 is via channels or slots 6, 7 with these cylinders tied together. The channels 6, 7 open into the cylinder 1, 3 in such a way that the Upper edges of the working pistons of these cylinders, the openings 6, 7 each to the im Open the diagram of Fig. 2 specified crank angle. The openings or channels 6, 7 serve both for the air inlet and the gas outlet. To that extent differentiates the arrangement does not differ from already used arrangements for reloading, in particular as they are known in two-stroke internal combustion engines.

In the reloading tube 5, a piston 8 (flying piston) is freely swinging and slidably arranged, the purpose and operation of which will be described. Farther are the same on the reload tube 5 controls 9, 10, il, 12 for opening and closing arranged, which od as valves. The like. Can be provided. The cylinders 1 and 3 have the same phase with regard to their crank position, with regard to their work cycle but are they against each other by two bars, i.e. H. 180 ° CA, offset. The cylinders 2 and 4 are assigned to each other in the same way as cylinders 1 and 3, only that they are offset from the latter by a crankshaft amount, like him common in four-cylinder engines or internal combustion engines with several cylinders is. As already mentioned, only the one according to the invention is required for further explanation Arrangement for cylinders 1 and 3 to be considered.

In the diagram of Figure 2, 13 denotes that crank position of Cylinders 1 and 3, each of which has the channels or slots 6, 7 from the top of the piston be steered up; this crank position is near bottom dead center 14, the top dead center is denoted by 15. In Figs. 1 to 8 is now a complete working cycle of the reloading tube 5 in connection with the motor cylinders 1, 3 illustrated, the one shown on the left of the drawing Arrangement schemes each the mode of operation and the one on the right in the drawing too See the diagrams to record the associated working times. In the arrangement schemes the exhaust gas is indicated by dots and the fresh air by dashed lines symbolized; the controls of the reloading tube are in the drawing simple flaps indicated.

According to FIGS. 1 to 8, the reloading tube device shown below works as follows: As can be seen from FIGS. The piston of cylinder 1 is in the expansion stroke, the piston of cylinder 3 in the intake stroke. In the crank position 13, where the slots 6, 7 are already open, exhaust gas from the cylinder 1 at the end of its expansion stroke passes through the slot 6 into the recharging tube 5, the control elements 9 to 12 of which are all closed at this point in time. The gas 18 entering under pressure drives the flying piston 8 in the direction of the cylinder 3 and pushes the air charge, indicated by arrow 16, into the cylinder 3, which was previously received in the reloading tube 5 during another work cycle.

3 and 4 show the operating state when the crankshaft has arrived at position 17 (FIG. 4). The flying piston 8 has now reached its dead position next to the cylinder 3 due to the exhaust gases of the cylinder 1 and has pushed the air charge 16 into the cylinder 3, while some of the exhaust gases 18 are located in the recharging tube 5. The reloading process of cylinder 3 is thus ended, and this cylinder begins compression; the slots 6, 7 are closed from this point in time by the working piston. While compression takes place in cylinder 3, at the same time cylinder 1 continues the exhaust stroke through the usual exhaust valve provided. When the crankshaft continues to rotate and has reached the position 19 according to FIG the recharging pipe, whereby the exhaust gas 18 to the outside via the control element il still open at this time, z. B. is displaced into the exhaust pipe not shown here. The flying piston 8 must of course be in its dead position at 3 so that it does not hinder the opening of the control element 11. As soon as all of the residual gas has been pushed out of the reloading pipe, the pipe 5 is only penetrated by pure fresh blower air, which, in order to increase the reloading effect, can be dammed up and pressurized by the fact that the control member 11 is closed earlier than the control member 9, with the fan 20 continues to work.

In Fig. 7 and 8, the working time is recorded in which the The crankshaft has completed one full revolution and is in position 21, which corresponds to the starting position 13 in FIG. 1 on the crank side. As can be seen the conditions with regard to the air-gas exchange in the reload tube are now opposite those of FIGS. 1 and 2 just reversed. Because now the cylinder 3 has its The expansion stroke has almost ended and the working pistons control the channels or Slots 6, 7, while all control elements 9, 12 of the reloading tube 5 meanwhile are closed. The exhaust gas 18 now penetrates from the cylinder 3 through the slot 7 into the reloading tube 5 and drives the flying piston 8 in the direction of the cylinder 1 back, with the cylinder 1 in the reload tube in an analogous manner as before 5 stored fresh air 16 being charged. The following The reloading tube is then flushed in a manner similar to that shown in FIG. is through the fan 22. In the illustration are only for schematic reasons of simplicity two fans 20, 22 used; in practice only one becomes expedient Provide fan that is switchable, or you will make the arrangement so that the rinsing of the reload tube with fresh air always in the same direction of flow he follows.

The alternating reloading process, as just described, can take place repeat cyclically as often as required. 9 to 12 is a modified embodiment of the invention shown in which in the reload tube 5 instead of a flying piston Guide devices 23 next to those connecting the reloading tube 5 with the cylinders 1, 3 Slots 6, 7 are arranged. The crankshaft position for FIG. 9 is shown in FIG. 10; it corresponds to the crank position according to FIG. 2. The guide devices 23 are preferably provided with a sieve-like number of through holes 24 as scattering nozzles and serve to ensure a tongue-like penetration of the exhaust gas flow into the recharge tube 5 to prevent and instead the exhaust gas flow in the reload pipe arise frontally allow. The exhaust gas jet 18 then displaces without the interposition of a flying piston the fresh air 16 after the cylinder 3. In contrast to the example according to FIGS 8 there are only two control organs in the execution of the reloading tube without flying pistons 9, 12 available. These can alternate to the outlet and inlet of the air and / or serve the gas; but they can also be used for both work cycles of the reloading tube be used so that, for example, the control member 9 for the fresh air inlet and the control element 12 is used for the exhaust gas outlet. In Fig. 11 is for this design the operating state of the reloading tube in the crank position 19 according to Fig. 12, wherein, as can be seen, the control organs in this working phase 9, 12 of the recharge tube are open and the residual gas 18 in the recharge tube 5 through the fresh air 16 conveyed by the fan 20 is expelled.

13 shows a reloading tube arranged between cylinders 1 and 3, functionally the same task as the reloading tubes described so far fulfilled, but differs from these by its aerodynamic shape. The same is arcuate and ends at its ends in the course of the channels 6, 7 each tangentially or almost tangentially into cylinders 1 and 3. on this way the mixture is formed by the simultaneous generation of swirl during reloading improved.

In the example according to FIG. 14, the reloading tube described so far is 5 is replaced by a pipe slide, designated as a whole as 25, which controls the air-gas exchange for the reloading of the cylinders 1, 3 in a similar manner as in the preceding has been described. This is in the pipe valve housing 26 with the inlet and outlet openings 27, 28 a tubular rotary valve 29 is arranged, which is from the (not shown) Crankshaft is driven off. The rotary valve 29 is provided with windows 30, which in interaction with the connection of the pipe slide with the cylinders 1, 3 producing channels 6, 7 and the openings 27, 28 the air-gas exchange in Bring the reloading organ in the same way as with the reloading tube 5 is the case. A flying piston can also be placed in the tubular reloading slide 25 be arranged, but not in the drawing for reasons of simplicity is shown. Such pipe slides are already known per se, but not in the arrangement according to the invention.

If you want the heat exchange between the exhaust gases and the Nc.chladerouber on the one hand or between the reloading pipe and the fresh air introduced into the same on the other hand favor, this can be done by the fact that a Internal ribbing is arranged; this must of course be designed in such a way that it with a suitable design of the flying piston a free-flying sliding movement of the latter in the reloading device or tube slide. This way you can save the potential energy of the exhaust gases and their heat content are also used, by inserting into the reloading tube or the reloading tube slide and therein stored fresh air charge warms up after closing the control organs, thereby is further pressurized and in this way the efficiency of the reloading device still enlarged.

Claims (14)

PATENT CLAIMS: 1. Four-stroke internal combustion engine with supercharging at at least two working cylinders, characterized in that, as in two-stroke internal combustion engines known per se, two cylinders (1, 3) out of phase in the work cycle work together in such a way that that alternately exhaust gases of one cylinder in the other cylinder a recharge effect, these cylinders being connected by a known reloading tube (5) are that with these cylinders over to the same in the vicinity of the bottom dead center provided slots (6, 7) is in communication and independently, d. H. from the usual The inlet valve is filled independently with fresh air, which is fed through the recharge pipe (5) provided control elements (9 to 12; 25) in the control of the slots (6, 7) coordinated rhythm stored in the pipe (5) and alternately by exhaust gases from one Cylinder is pushed over into the other cylinder, whereupon those present in the tube Residual gases are expelled by fresh air entering the same again. 2. Four-stroke internal combustion engine according to claim 1, characterized in that each during the extension and intake strokes or the simultaneous compression and expansion strokes of one or the other cylinder (1, 3), the slots (6, 7) closed and control members (9 to 12; 25), preferably longer for the air inlet than for the air or gas outlet, are open, while at the end of the expansion stroke or at the same time Suction stroke of one or the other cylinder (1, 3), the slots (6, 7) open and the control organs (9 to 12; 25) are closed. 3. Four-stroke internal combustion engine according to claims 1 and 2, characterized in that the Nachladerohr (5; 23) slots connecting with the cylinders (6, 7) of the working piston j in each case in the region of bottom dead center (14) at the same crank position, but out-of-phase work cycle. 4. Four-stroke internal combustion engine according to the claims 1 to 3, characterized in that a known free in the reloading tube (5) movable drive link (8), e.g. B. in the form of a free-flying piston, arranged is that gcschalten between the air and exhaust gas column during its back and forth movement is. 5. Four-stroke internal combustion engine according to claim 4, characterized in that the drive member (8) is in its dead center position in each case with that cylinder is located, which has just been reloaded, so that the drive link (8) alternately of the exhaust gases exhausting through the slots (6, 7) into the recharging pipe (5) is moved towards the other cylinder. 6. Four-stroke internal combustion engine according to claims 1 to 5, characterized in that each of the cylinders the same channels or slots (6, 7) for the outlet of the exhaust gases and the inlet the fresh air to be recharged. 7. Four-stroke internal combustion engine according to claims 1 to 5, characterized in that the fresh air to be introduced from the outside into the recharging pipe (5; 23) is conveyed by a fan (20, 22). B. Four-stroke internal combustion engine according to claims 1 to 5, characterized in that the fresh air to be introduced into the reloading pipe (5; 23) is conveyed by the crankcase pumping action of those cylinders which have a suitable crank offset, e.g. B. 90 to 270 ° CA have. 9. Four-stroke internal combustion engine according to claims 1 and 2, characterized in that a tube slide (25) actuated by the internal combustion engine is used as the reloading tube, in which the tube slide housing ( 26) has inlet and outlet openings (27, 28) and the rotatable part (29 ) Windows (30) are arranged in such a way that they, in cooperation with the slots (6,7) of the cylinders (1, 3), bring about the gas-air change in the tubular slide for reloading. 10. Four-stroke internal combustion engine according to claim 9, characterized in that a flying piston is slidably arranged in the tubular slide (25) which works in the same way as the flying piston (8) in the reloading tube (5). 11. Four-stroke internal combustion engine according to claims 1 and 2, characterized in that that instead of a flying piston (8) in the reloading tube (5) known guide devices (23) are arranged, which the exhaust gases in a broad front over the entire cross-section of the reloading tube. 12. Four-stroke internal combustion engine according to claim 10, characterized characterized in that the rinsing of the reload tube with fresh air is always in the same Direction of flow takes place. 13. Four-stroke internal combustion engine according to claims 1 to 12, characterized in that the reloading tube (5) between the associated Working cylinders (1, 3) is arcuate and in the course of the channels or slots (6, 7) opens tangentially into the cylinder (1, 3). 14. Four-stroke internal combustion engine according to claims 1 to 13, characterized in that for the purpose of increasing the heat exchange in the reloading tube, an internal ribbing permitting the movement of the free-flight piston (8) is arranged. Considered publications German Patent No. 646 900; French Patent No. 889,617; British Patent No. 592 995.