DE2322175A1 - INTAKE PIPE ARRANGEMENT FOR CARBURETTOR COMBUSTION MACHINES - Google Patents

Description

Applicant: ν. Seid KG Vergaserbau, 2 Hamburg 64, 2322175 Inventor: Hans A. Frhr. v. Seid, Ing. LOIL / O

Patent specification.

Intake manifold for carburettor internal combustion engines.

The invention relates to a carburetor internal combustion

machines, the transport of the fuel-air mixture ., Serving suction pipe arrangement with a Branching, the channels of which lead to several cylinders that work with an uneven firing order.

As it turned out, the mixtures that enter the individual cylinders differ greatly in their proportion of combustion air due to the uneven firing sequence. In a certain speed-load range, for example, the cylinder that aspirates after the larger time interval, ie the first intake cylinder, has a mixture with a lower proportion of combustion air than the next cylinder that ignites after the shorter time interval. The mixture in the cylinder with the first intake is richer in this case. This different mixture composition in the individual cylinders has a detrimental effect on the efforts to purify exhaust gases. In the case of combustion ₄ with a lack of air, the proportion of hydrocarbons and carbon monoxide in the exhaust gas is high, and in the case of a higher proportion. Excess air reaches the nitrogen oxides 4-hr maximum. This not only pollutes the atmosphere, it also means that the energy contained in the fuel cannot be used to a large extent. In order to achieve optimal combustion, the aim should therefore be to achieve the same mixtures in the individual cylinders.

409843/0225

Although it is known ,,, by compensating lines to bring about an equalization of the mixtures between different cylinders, but has It is only successful in the lower speed-load range set. ,

It is also known to use different channels in the branch channels that lead to the individual cylinders Provide cross-sections to the first aspirating To lean cylinders through narrower, more strongly curved and more heated pipe cross-sections to such an extent that they do not get a richer mixture than the cylinders that will be aspirated later (e.g. Ford V-6 cylinder and DB patent 2008393).

The object of the invention is to provide the An.r ~ bring about the equation of the Gbn in the individual cylinders in all areas of the engine speed map, instead of throttling the cylinders that first suck in there is an increase in the filling of the cylinders that suck in later Cylinder is achieved and accordingly the goal of mixture equality in all cylinders is achieved without loss of performance of the engine. ■

The mode of operation of the intake pipe according to the invention will first be described using the example of a 4-cylinder in-line engine explained. -

Have conventional intake manifolds for 4-cylinder engines usually a U-shaped shape, with the carburetor connected over the center of the apex of the intake manifold and the two pipe arms of the suction pipe at a more or less large distance from the central carburetor connection are designed as double pipes by a partition running in the direction of flow (e.g. Opel).

Other suction pipes have four individual pipe lengths, the one with a slight curvature spread like 4

409843/0225

Fingers of one hand radiate from a slightly enlarged carburetor connection manifold to the individual ones Lead cylinders (e.g. BMW and Citroen). With these intake manifolds, the flowing out of the downdraft carburetor is used Mixture sucked off on one side under the carburetor connection and redirected.

For structural reasons, four-cylinder in-line engines have a firing order that does not depend on the arrangement of the cylinders but with consecutive numbering the cylinders are 1-3-4-2 or 1-2-4-3.

Four-cylinder in-line engines with U-shaped intake manifold therefore have the disadvantage of a non-uniform suction sequence in the two suction pipe arms, because one Arm leads to cylinders 1 and 2 and the other arm leads to cylinders 3 and 4. '

From the assumed ignition position 1 - 3 - 4 - 2 results that the cylinders next to one another suck in 2 and immediately one behind the other, so that during this time in the intake manifold arm leading to cylinders 3 and 4 as long as there is no flow until cylinders 3 and 4 suck in immediately one after the other and then the mixture in to cylinders 1 and 2 leading suction tube arm comes to rest.

The intake cycle of the cylinders is based on on the angular position of the crankshaft to 180 ° - 540 ° 180 ° - 540 °, so that with cfer assumed firing order cylinders 2 and 3 each prime first after the break (540 °). This intake sequence now leads inevitably leads to a non-uniform mixture distribution, especially at full load in the lower speed range and in the partial load range a mixture that is too rich for the first intake cylinder and thus one unpleasant increase in the proportion of toxic exhaust gas components caused.

409843/0225

At full load and at low speeds, it takes place because of the lower air speed in the carburetor the mixture is no longer adequately prepared, as the fully open throttle prevents the mixture from increasing in speed. There it comes due to the low intake manifold vacuum does not result in sufficient evaporation of the fuel, see above that larger droplets of fuel entrained in the mixture are deposited on the wall of the intake manifold. Of the Fuel film deposited on the inner wall of the intake manifold crawls in the direction of the inlet ports of the cylinder head, in which it is because of its high temperature evaporates.

This evaporation of the fuel now takes place during the suction pauses before the two of them start working primary suction cylinders 2 and 3 lead to an enrichment of the mixture resting in the relevant intake manifold arms Apart from the increase in toxic exhaust gas components associated with a mixture enrichment Under certain circumstances, the enrichment can be so strong that the ignition limit is reached or exceeded, while the mixture depletion for the second suckling Cylinder can go so far that the lower ignition limit is reached or even fallen below. This Night manifests itself in restless engine running and combustion misfires when the machine is still cold and in that the fuel metering when accelerating can no longer be adjusted to the optimum mixture for each cylinder *. A general slimming of the mixture however, since the second-aspirating cylinders would also be subject to it, it is forbidden to do so that it is easy to under-cry for these cylinders the ignition limit can come.

An even filling of the cylinders is in engines whose cylinders are asymmetrical in the intake sequence work, that is, according to different

409843/0225 " ⁵ "

long suction pauses one after the other, also in Idle and not given in the partial load range, if all cylinders are to be supplied with mixture from just one carburettor

As a result of the intake pauses of different lengths, the intake manifold vacuum is reduced to varying degrees in the partial load range by the mixture flowing in via the throttle valve gap, so that the filling of the respective intake cylinder changes. ; That means that after a long pause ^! aspirating cylinder receives a larger filling than the cylinder aspirating after a short intake pause. In order to avoid this disadvantage, in the case of U-intake manifolds, the equalizing lines which bring about a certain pressure equalization in the intake manifolds in idle and part-load areas are used. These mixture equalizers only have a small cross-section.

In the manifolds leading to the intake valves of the U-shaped intake manifolds, due to the firing sequence, there are asymmetrical back oscillations with the mentioned time intervals of 180 ° -540 ° - 180 ° -540 ° crank angle, which relate to .das work of the carburetor can have a very unfavorable effect if it has a large inflow cross-section and consequently with low negative pressure, i.e. low air velocities should work. These vibrations increase the discrepancy in the filling values in the cylinders and can lead to the fact that the machine can only be operated very over-rich at higher speeds, runs unevenly or even stops working at intervals.

With the one-sided 4-finger tube for 4-cylinder machines the situation is similar. Here, those could arise in the individual distribution pipes separated asymmetrical oscillations of about 220 ° suction time and about 500 ° rest time " all of the pipes arrive symmetrically with a 180 ° sequence in the distribution chamber, if di <

4098A3 / 022S.

The length of the distribution pipe is really the same and adapted to the valve overlap and the engine speed would be, which is hardly feasible due to the space required under the hood. Here, however, occur in the one-sided distribution chamber uncontrollable vibration phenomena and eddies fertilize, the pulsating in conjunction with the one-sided suction of the mixture under the carburetor One-sided flow separations lead to the atomizer of the carburetor, which leads to an even mixture supply prevent all cylinders. Also occur in the carburetor because of the great distance from Center of mass of the machine. Strong vibrations, which are reflected in the critical speeds on the float can be transmitted so that the atomizer is periodically flooded in this speed range can·

The new intake pipe "of the present invention, the object · the uniform GempLschversorgung ■ all the cylinders of the engine at an optimal filling of the cylinders is achieved even in high speed ranges, characterized in that the unbalanced vibration of the gas column of l80 ° -540 ^o -l8Ö ^o -540 ° In the gas supply lines are transformed into a symmetrical oscillation system with a regular 360 ° time sequence, which is controllable and also causes a shock charging of the cylinders without disturbing the even, bilateral symmetrical »suction of prepared mixture from the carburetor at its connection. The intake manifold according to the invention is also characterized by an inner surface that is relatively small in terms of oscillation length, which is largely in the thermal area of the cylinder head, so that the wall here is dry anyway, while in the other part of the intake manifold a constant, rectified flow rate of the mixture is maintained, which support t from the liquid sale of the mixture flow in only two large-scale arcs, the failure of combustion

409843/0221

droplets of substance from the mixture and thus the wall

wetting reduced to a minimumDescription:

Fig. 1 shows an embodiment of the intake manifold according to the invention for a & - cylinder in-line engine in horizontal section.

Fig. 2 shows? the same example in a view of the connecting flanges to the cylinder head.

Fig. 3 shows the same example in a vertical cross-section through the center of the intake manifold.

Fig. 4 shows the same example in a vertical cross section through the front mixture feed bend and the connecting flange to the inlet port of the front cylinder.

Fig. 5 shows a similar example, schematically, in which part of the intake manifold is cast into the cylinder head.

Fig. 6 shows the example according to Fig. 5 in the vertical Cross-section.

Fig. 7 shows another example of the intake manifold according to the invention for a 4-cylinder V-engine schematically in supervision.

Fig. 8 shows the example according to Fig. 7 vertically

kaien cross-section.

Fig. 9 shows an intake manifold according to the invention in the version for an 8-cylinder V-engine, schematically in supervision.

Fig. 10 shows an intake manifold according to the invention for a 6-cylinder V-engine schematically in plan view.

409843/0225 _ ₈ .

Fig. 11 shows the suction pipe according to Fig. 10 in a vertical cross-section «

Fig. 12 shows a suction pipe according to the invention in the " Version for a 6-cylinder in-line engine viewed from above.

Fig. 13 a and b show in-line engines with a variation of the intake manifold according to the invention *

Fig. 14 shows schematically a suction diagram of two adjacent to one another, connected to the suction pipe according to the invention, in a time interval of 180 ° one after the other aspirating cylinders of a four-cylinder four-stroke engine.

For the figures 1-5, the same reference numerals are valid for the same parts of the subject matter of the invention. That The intake manifold according to the invention has for in-line four-cylinder engines the shape of an endless elongated loop made up of two straight pipe sections 5 and 6 as well two end arcs 7 and 8 is composed. All inlet ports 9 of the cylinders 1-4 are through the straight pipe

0 *

stretch 5, which is screwed to the cylinder head 11 with the flanges 10, with the full intake manifold cross-section tied together. At the front and rear end opening of the straight pipe section 5, the front closes Mixture feed elbow 7 and the mixture feed elbow 8 at the rear. The pipe bends 7 and 8 each run in Semicircle of 180 ° and are in turn connected to one another by the second outer straight pipe section 6, the has the connecting flange 12 for the carburettor in the middle.

The mixture flowing through the connection 12 into the pipe section 6 branches under the flange 12 and flows half to the front in "the pipe bend 7 and half to at the back into the pipe bend 8, so that the straight suction pipe section 5 lying at the inlet ports 9 on both Ends is fed with mixture. With an ignition sequence, 1-.3-4-2, the two front cylinders 2 and with a time interval of 180 ° and in alternation.

A09843 / 0225.

then the hip pair of cylinders 3 and 4, also with 180 ° time sequence.

As can be seen from the suction diagram in Fig. 14, the intake times of a cylinder pair 2, 1 or 3, 4 overlap due to the intake valve opening time, "which extends far beyond the UT with approx. 56 °, considerably. The inflow of mixture in a pair of cylinders 2, 1, as the diagram shows, moves with a certain amount through the changing piston speeds caused fluctuation, fluid from one cylinder 2 of the pair in the other Cylinder 1 over, so that one entitled for both cylinders 2, 1 of the pair the emergence of a common one Suction wave of approx. 416 ° duration can start, which shifts from one to the other cylinder.

Since a suction wave is induced alternately by the front 2, 1 and the rear pair of cylinders 3, 4, the result is in the straight suction pipe section 5 a symmetrical one Oscillation of about 30 cm oscillation length, which occurs during the intersection of the inlet valve opening times of a couple a charge of the primary suckling 2,3 and towards the end of the common intake period causes the second intake cylinder 1,4 to be charged,

The charging of the second intake cylinder 1.4 is supported by the fact that the straight intake manifold over the Gerais feed sheets 7 and 8 of both

Pages is fed. For example, has a primary suction cylinder 2 due to the vibration wave advancing in the pipe 5 and the first intake a large amount of filling, largely obtained via the mixture feed bends 8, The oscillation continues in the pipe section 5 and hits in front of the inlet port 9 of the cylinder 1 on the induced by the suction des.Zylinders 2 and with a delay over the mixture feed elbow '7 incoming counter-wave, which as a result of the long feed-in time in the outer tube 6 carries a rich mixture.

409843/0226 - 10, -

Generate the vibration waves that meet here from the pipe section 5 and the feed bend 7 In front of the inlet port of the cylinder 1 there is now a pressure tip which ensures that it is also with rich mixture is charged '.

If one chooses the length of each mixture feed elbow 7,8 so that it, together with half of the outer straight intake manifold section 6, has an oscillation length of Carburetor 12 to z'ur the outer inlet port 9 of the cylinder 1.4, which is the length of the inner straight Pipe section 5 corresponds to ideal suction conditions at the carburetor connection 12 and a uniform one Mixture supply and optimal filling of all cylinders even at full speed and load.

From Fig. 2, which shows the suction pipe in a view of the connecting flanges 10, it can be seen that the Row of flanges 10 of the usual engine series in Adapted motor vehicle, sloping from front to back, while the rear half of the pipe section lies horizontally in order to avoid unintentional fuel enrichment xm rear suction pipe part 5, 8. There is also a small condensate collecting channel here 15 is provided, which is vented to the outside through a narrow bore 16. The hole 16 leaves any after the machine has been switched off, the fuel that has accumulated flows off and is so narrow that the small amount of air sucked in by it while the machine is running, even when idling, does not disturb. Another, The narrow vent hole serving the same purpose is located in the middle of the lower wall of the pipe section 6, which here has a small oval condensation bowl 18 which is vented via the bore 17.

Pipe section 6 is designed to fall slightly on both sides of the carburetor connection 12. The gradient sets continues in the mixture feed bends 7, 8.

- 11 -

409843/0225

Under the connecting flange 12, the pipe section 6 initially has the cross section of a triangle with rounded corners 19 in Fig. 3. This cross-section quickly turns into a round circular cross-section on both sides of the condensation bowl 18 20 over, which merges into el'nen elypfischen cross-section 21 at the entry into the mixture feed elbow 7,8, which is more high than wide, which facilitates the passage of the mixture through the arches. 7, 8. At the exit of the arches 7, 8 the height of the cross section decreases while its width increases. In the inner straight Pipe section 5, the cross-section 22 is more wide than it is high and so adapts to the flat-oval shape of the inlet ports 9 at. The front mixture feed bend 7 is in the usual manner by a wind deflector 23 in front of a Hypothermia protected by the downdraft of the machine's fan.

To preheat the mixture and to reduce the wall wetting, a pipe section 6 with a preheating chamber is required 24 equipped, which is closed at the bottom by the cover 25, and of the circulating lubricating oil Machine is flowed through. An O-ring 26 is inserted into the sealing surface, which ensures a perfect Sealing ensures. Inside the preheating chamber 24 is the lower outer wall of the pipe section 5 with heating fins 27, which partly by enlarging the heat-transferring surface reduces the thermal conductivity equalize the lubricating oil, partly for a multiple deflection and turbulence of the oil flow

care for. The lower end cap 25 of the preheating chamber 24 is equipped with longitudinal cooling fins 28, through which the exhaust air flow of the fan passes. The engine oil flowing through the Voiwärmkammer 24 is partly from the suction pipe 6 through the heat transferred to the inflowing air mixture, partly from the cover 25 cooled by the heat given off to the fan wind, so that the preheating chamber 24 also forms an oil cooler, which replaces the usual water preheating. In contrast to conventional oil coolers

409843/0225

- 12 -

2322Ί75

the main part of the dissipated heat is not absorbed the outside air is released to the sucked-in fuel mixture.

This oil cooler 24, 25 is effective in every operating state of the engine. When the engine is throttled a strong relaxation of the mixture behind the throttle and thus, as in every refrigeration machine, a powerful cooling effect. When the throttle is wide open, the pressure drop is low and in relation to the Cooling not very effective. This is compensated by the fact that when the throttle is open a much larger Amount of air is enforced through the suction pipe 6.

Since the oil temperatures of today's souped up engines are already prolonged highway driving close to the danger limit for lubricity and leaking crankshaft bearings are not uncommon, as is the low temperature difference of about 20 ⁰ C, which produces this oil cooler, just tip the balance in order keep the oil temperature in the safe range.

Figures 5 and 6 show an identical suction tube with the same function, the inside of which is straight Section 5 of the intake manifold loop in the cylinder head is poured. Since this pipe part 5 from the inlet valve stems 30 is penetrated and is directly above the inlet valve actuator 31, the inlet ports 9 are omitted and there are * only * two connecting flanges 10 for the outer part 6, 7, of the suction pipe is required. The advantages of these constructions are in d'er even shorter connection of the Inlet passages 31 in an even more direct way, in improvement the flow conditions in the pipe section 5 via the inlet valves 31, in the reduction of the inner wall surface of the suction pipe system 5,6, ^ 8 by eliminating the branching inlet ports 9, in the further approach of the carburetor 12 to the center of gravity <ier machine, in the absence of 2 flanges,

409843/0225 - 13 -

2 seals and 4 studs, in the recess of weight and the even clearer structure of the machine.

Since part of the supply bends 7, 8 in the cylinder head 11 is and the Rohirteil 6 of the Saugrohrscheleife is moved closer to its heat zone, can with less Preheating of the outer raw part 6 got by will. In this version, the preheating consists only of a thermally conductive bolt 32, on the one hand mid: is screwed to the cylinder head 11 and on the other hand to the lower center "of the intake pipe part 6 approaches. The heat flow in the bolt 32 can be increased by a pressed-in copper rod 3a.

In Figures 7 and 8, the intake manifold according to the invention is modified for a 4-cylinder V-engine shown schematically, whose crankshaft is cranked 60 ° -120 ° - 60 ° -120 ° and the firing sequence 1-3-4-2 having. In this machine, cylinders 2 and 1, as well as cylinders 3 and 4, suck in asymmetric Interval from 120-240-120-240 ° in a row. The usual H-shaped suction tube for this machine Ground plan is replaced according to the invention by an endless pipe loop, one of which is attached to the cylinder blocks 1, 2 and 3, 4 connected vibrating pipe length 5 as well as one feeding through the pipe bends 8 in their ends Mixture feed section 6 with centrally located

which has the carburetor connection flange 12, so that from the mixture flowing into the pipe section 6 from the carburetor is branched into its halves. *

As a result of the special design of this 4-cylinder machine the pipe section 5 of the endless suction pipe loop can here not be a continuous straight line, but rather has a S-Porm, which consists of the straight end pieces 5a, the bends 7 and the continuous, diagonal in the horizontal lying connecting piece 5b consists of the end pieces 5ja each lying parallel to the machine, 7,8 flowing in from both sides * mixture into the

- 14 -

409843/0225

Inlet ports 9 of blocks 1, 2 and 3, 4, with the one through an arch 8 on the shorter one, through one of the arches The inflowing mixture reaches the inlet valves of a cylinder pair 1,2 or 3,4 over a longer distance. Included the second suction cylinder 1.4 of a pair 1.2 ad and 3.4 is each caused by the pressure peak "of the counter-oscillation the end. the connector 5b> in the filling ' favored, so that the usual disadvantage of the secondary suction cylinder is compensated. Because the cylinder pairs 1, 2 and 3, 4 only suck at intervals with longer intermediate times, can be fed into the vibration tube 5b Via the ends 5a of the mixture coming abundantly from the pipe 6 enter alternately. The carburetor 12 watery pipe, i; ück 6 crosses the connecting pipe 5b diagonally with a slope on both sides, which continues in the bends 8 up to the height of the pipe section 5.

In Fig. 9, the intake manifold of an 8-cylinder V-engine shows in the scheme is again according to the invention a straight pipe section 5 connecting the inlet ports 9 is provided for each cylinder block 1-4 and 5-8, the mixture at both ends via pipe bends 7.8 from another pipe section with the carburetor in the middle 6 is fed, the sections 5 with the bends 7, 8 and the pipe section 6 two endless loops form, in which, however, both loops 5, 7, .8, 6 form a coherent system because they are together are closed by the pipe section 6, so this feeds into the pipe bends 7, 8 of both loops.

As described in the introduction, the suction sequence of the 4 cylinders of a block in each one at the intake ports 9 lying pipe section 5 induces a symmetrical oscillation of 360 ° time sequence. This occurs the oscillation of one block 1-4 to that of the other block 5-8 shifted by 90. This timeframe The suction conditions would be shifted in common used pipe section 6 interfere under the carburetor connection 12 and as a result of the contiguous suction pipe

A098A3 / 0225

COPY

systems lead to an unfavorable mutual influence of the vibrations and thus the flexibility of the filling the cylinder lead if the bends 7 and 8 would have the same length and the Rohrstre.cke 6 with a dei straight stretches 5 would be equal in length.

The time shift of the 360 ° oscillations in the Blocks 1-4 and 5-8 by 90 ° is therefore compensated according to the invention in that the pipe section 6, .the the carburetor carries, for about half the length of a line 5 is shortened and that at each section 5 a short pipe bend 7 and a longer pipe bend alternately 8 is connected, whereby the vibrations in the tubes 5 harmonize with each other and the Flow velocities in the two halves of the tube 6 come into harmony.

In Figs. 10 and 11, the system of the endless suction pipe loop according to the invention for a 6-cyl. V-engine shown with cylinder blocks 1-3 and 4-6 at a 60 ° angle. With a firing order of 1-4-2-5-3-6 For this machine there would be three separate, crossing cross connections with one carburettor each necessary. With the loop system according to the invention, the machine can be optimal. With only one carburetor be driven.

In each engine block 1-3 and 4-6 either the cylinders 1, 2, 3 suck one after the other at equal intervals of 240 ° or the cylinders 4,5,6. Since the suction sides of one block 1,2,3 are those of the other block 4.5.6 by 60 ° ahead, the sucking of the cylinder groups induced vibrations in one common intake manifold interfere with each other and some of the cylinders would get too rich mixture while other cylinders would have to work too lean. In a manner known per se, therefore, for each cylinder group

however .in accordance with the invention
.separiert ©, endless suction pipes provided, which in the suction pipe system according to the invention are not of two

4098A3 / 0225 - ie -

co * ^v

-.16 -

are supplied with fuel mixture separately but only mm from a carburetor. For this purpose, it is necessary to insert a pipe section 36 carrying the carburetor 12 in the center, the oscillation length of which compensates for the difference between the oscillation cycles in the two endless intake manifold loops.

The lack of space between the cylinder heads 11 of the in Cylinder blocks 1, 2, 3 and 4, 5, 6, which are at a close angle to each other, are taken into account according to the invention, that the two pipe loops are largely on top of each other and cross each other at the pipe bends 7, 8, so that in each case a feeding pipe section 6 lies above a vibrating pipe section 5. In the At the apex of the slightly curved pipe sections 6 the transverse distributor pipe 36 opens.

A vibration is induced in each pipe section 5, alternating a counter shaft in the pipe bends 7, 8 generated, which brings fresh mixture and provides a charge of all ^ r cylinders.

With the 6-cylinder in-line engine sketched schematically in top view in Fig. 12, basically the same thing happens Suction pipe system with two endless loops for one each Group of three 1, 2, 3 or 4, 5, 6 of the cylinder block and the intermediate vibration pipe supplying it with mixture 36 apply.

In front of the inlet valves of each cylinder group 1,2,3 "or 4,5,6 is a pipe section 5 connecting the inlet ports 9, which is on both sides via pipe bends 7,8 mixture flows from the pipe section 6 closing the loop, which is the apex of the slightly curved Pipe sections 6 from the connecting pipe 36 flows in, which carries the carburetor 12 in the middle.

In Fig. 14 a variation of the invention is shown schematically in plan view, which is suitable for a 6- or 8-cylinder in-line machine is used

409843/0225 - 17 -

and also with only _r a carburetor works.

This engine is also provided with two endless intake manifold loops, which, however, in contrast to the versions according to Fig. IQ-12 not completely separated from each other but make partial use of the same stretch of pipe that is an integral part of the Forms suction pipe loops and .die has the carburetor flange 12 in the middle.

In the example chosen, an 8-cylinder in-line engine Cylinders 1-4 and 5-8 are grouped together, each with an endless loop of the intake manifold have £ n. The straight oscillation sections 5, which each supply four inlet ports 9 of four cylinders, run from the center of the machine in separate arcs 7, which cross each other at a distance from one another to the connecting line 36 lying parallel to the cylinder block, φΐβ "extends over the connection of the Bends 7 continue on both sides with the pipe sections 6. which merge into the outer pipe bends 8. The pipe bends 8 each open at the ends of the engine block into their associated pipe section 5.

The time shift of the vibrations induced in the pipe sections 5 of the cylinder group 1-4 and the group 5-8 is compensated for in this intake manifold arrangement in that the groups 1-4 and 5-8 are only connected to each other via pipe sections that are matched in length. For example, the shortest connection between cylinder 4 and cylinder 5 runs via the loop formed from ή the bends 7 and the connecting pipe 36, while a longer section is made up of bends 7 and one pipe section 5 and 6 each. The longest connection between the cylinders 5 and 6 runs over both pipe sections 5, both bends 8, both sections 6 and the connecting pipe 36. Since the motors are almost without exception installed in the chassis inclined in the longitudinal direction, the bridge can be bridged

409843/0225

the pipe bend 7 make favorable.

Figure 14 shows the velocity diagram. The ⁿ two piston velocities occurring next to each other and sucking in 180 ° apart are shown in curve K, the inlet valve opening times on the straight line and the flow velocities of the mixture in curve S. The resulting speed R in the pipe section 5 resulting from the inlet time overlap is shown in dotted lines.

The suction pipe according to the invention primarily yields an improvement in exhaust emissions. This is a lot when limited to just one carburetor easier to secure than when operating with several carburettors, which can result in setting errors.

The possible applications of the invention are not exhausted with the exemplary embodiments shown. Horizontal carburetors can also be used as integral components in the endless suction pipe loop, for example between the ends of the oscillation path 5, 10 and the pipe bends 7, 8 are inserted, the manifold pipe 6 would have only one air filter in the middle. If in the present drawings for the sake of simplicity and exhaust gas improvement on multi-carburetor arrangements was waived, this does not mean that no protection is claimed for them, insofar as it is in the intake manifold system around an endless loop acts with oscillation path according to the invention.

409843/0225

Claims (9)

1.) mixture Leading pipe for carburetor engine having a branch whose Kanäle.zu perform a plurality of cylinders, which operate with uneven firing sequence, characterized by the formation of the pipe as an endless loop having two large sheets and two ¹ straight Streaken, of which one , located close to the row of inlet valves of the cylinder head, connects all inlet ports of the cylinders with each other by the shortest possible route and is fed in at both ends from a mixture feed elbow that opens here at the end, while the other straight stretch of the intake manifold loop, arranged parallel to the cylinder row, has the connection in the middle for only one carburettor and merges into the mixture feed elbow at both ends (Piguren.l - 4). 2. Suction pipe according to claim 1, characterized in that the straight 'suction pipe stretch, the tight', on the row tier intake valves is located directly above the intake valve plates and from the valve stems penetrated is cast in the cylinder head and that at both ends of the feed arches for the mixture are flanged, their mixture from the outside and parallel to the cylinder head the branch pipe section that closes the endless loop and the carburettor in the middle carries and is moved closer to the cylinder head, received (Figures 5 and 6). 3. intake manifold according to claim 1, characterized in that for 6- and 8-cylinder engines, the cylinder are divided into two groups with identical, but time-shifted firing order, two endless Suction pipe loops are provided, each supplying a group and in their outer pipe sections a mixture distribution pipe opens that carries the carburetor in the middle and its length to the 409843/0225 " ² " Time shift of the vibrations in the two pipe loops, these coordinated to compensate is (Figure 12). 4. suction pipe according to claim 1 and 3, characterized in that that the two intake manifold loops are two identical but time-shifted firing, cylinder groups of a V-engine with their straight pipe sections one above the other and always a feeding one . Distribution line via a connecting line to the valve inlets Oscillation path, where the feed arcs intersect in the oscillation paths and the branch pipe, which supplies mixture to the manifolds, transversely between the cylinder heads (Figures 10 and 11). 5. suction pipe according to claim 1 and 3, characterized in that two endless on a 90 ° V machine Intake pipe loops with straight oscillation pipe sections located at the intake valves are provided, their out & end pipe, the center of the carburetor flange has, is used jointly for both pipe loops and in the pipe bends of both loops feeds * where the time shift of the identical suction sequences of the cylinder groups in the Vibration pipe sections are compensated by that on each straight pipe section in front of the valves a long and a short section alternately Feed pipe bend is connected, which opens into the • common outer section (Figure 9). 6. intake manifold according to claim 1 and 3, characterized in that an'einem 6- or 8-cylinder in-line engine two endless suction pipe loops for each one identical but with a time-shifted sequence suction Cylinder group are provided, each one in front of the Have vibration pipe section lying at the inlet valves, their outer feed arches arranged at the respective end of the cylinder block in the Pass over striving outer pipe sections 4Q9843 / 022S - 3 - and their inner feed arches, which are approximately in the middle of the cylinder block, cross one another at one inner branching line are connected, which has the carburetor in the middle and the outer tube tr ecken the loops complementary connects, whereby the feeding branch line a common Forms part of both loops' (Figures 13 a and b 7. intake manifold according to claim 1, characterized in that the lying in front of the intake valves of the engine Oscillating pipe section in 4-cylinder V-engines is given an S-shape so that the inlet ports of the one cylinder head via a vibrating tube lying diagonally in the cylinder square the intake ports of the other cylinder head have a connection with the full intake manifold cross-section the open ends of which are connected to pipe bends to be mixed, which also produce the mixture from a A distributor pipe arranged diagonally between the cylinder heads and having the carburetor in the middle and the oscillation tube crosses, making the entire suction tube an endless, in plan view 8-shaped loop forms (Figures 7 and 8). 8. intake manifold according to claim 1, characterized in that in 6- and 8-cylinder engines, the cylinder ignite and suck in groups in an identical but time-shifted sequence for each group separate, an endless loop, consisting of a vibration path in front of the inlet valves, two connected pipe elbows and the the loop closing, external distributor pipe with a central carburettor existing suction pipe is provided. 9. Suction pipe according to claims 1-8, characterized in that the condensate pan located under the carburetor and the deepest pipe section in front of the last inlet ports of the cylinder bank through a 409843/0225 - ⁴ ~ downward narrow bore is vented to the atmosphere. 10 · Suction pipe according to claims 1-8, characterized in that the external distributor pipe, which carries the downdraft carburetor in the middle, a heat exchanger through which the oil from the engine flows is cast, which on the one hand heats to the distributor pipe via internal heating and conducting fins and on the other hand transfers heat to the exhaust air flow of the fan via external cooling fins. 409843/0225 Blank page