DE3314911A1 - MULTI-CYLINDER COMBUSTION ENGINE WITH A COMBINATION OF TURBO AND PULSE CHARGES - Google Patents

Description

1-1, Hinodai 3-chome, Hino-shi, Tokyo 191, Japan-

Multi-cylinder internal combustion engine with a combination of turbo and pulse charging

The invention "relates to a multi-cylinder explosion engine with a combination of a turbocharger and a pulse charger.

It is known to provide multi-cylinder diesel engines with a compressor or "supercharger" to achieve the to increase the volumetric effectiveness of the engine. Acquaintance, widespread superchargers include, for example, turbo

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charger and impulse charger. Usually either the Turbocharger or the impulse supercharger used individually with the diesel engine.

With turbochargers, part of the waste heat from the exhaust gas is used to bring air into the engine cylinder under one To press pressure which is greater than atmospheric pressure. Turbochargers have a disadvantage in that they do do not increase the volumetric effectiveness over the entire speed range of the engine. For example a maximum increase in volumetric efficiency In the range of high engine speeds aimed at, the volumetric efficiency is at low engine speeds smaller than with normal air intake.

The same problem arises with impulse chargers where also a substantial increase in the volumetric]! Efficiency at low engine speeds is accompanied of a reduction in the volumetric efficiency at high engine speeds.

Turbochargers and impulse superchargers can have a maximum volumetric So only achieve efficiency in certain speed ranges, while outside these ranges lower volumetric efficiency is recorded. To address this disadvantage, it is common to use turbochargers and impulse superchargers are designed in such a way that the volumetric effectiveness is maximum in an engine speed range, in which the engine works frequently or in which the highest engine power is required.

The speed range in which the motor is impulse charged to achieve maximum volumetric efficiency, hereinafter referred to as the "adjustment area".

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Various attempts have been made that to overcome problems encountered with turbo and pulse chargers. In JP-PS 57-2892 are for the turbocharger on the one hand and the impulse charger on the other hand, different adaptation areas are given and the common The manifold of the suction pipe is kept short. Another suggestion sees only "impulse charging" before, whereby the engine cylinders are divided into two groups, the intake strokes of which do not overlap and which are each connected to respective intake manifolds, each of which has a first manifold, which is connected to a single second manifold to increase volumetric efficiency. The second manifold serves as a damping chamber so that the intake manifolds are independent Effect impulse charging. In a modification of this arrangement, the first headers are under an arch connected to the second manifold and the second manifold and the manifold serve as damping chambers for two pulse charging tuning ranges. In these earlier arrangements, however, is the form of the connection between the first and second headers with regard to an increase in engine power no further been investigated. -

Accordingly, the present invention is the The task is to provide a multi-cylinder explosion engine with a combination of turbo and impulse charging, whose suction pipe system has an increased volumetric Impulse charging enables efficiency.

According to the inventive solution to this problem are the cylinders of a multi-cylinder internal combustion engine are divided into two / one groups, the intake strokes of which do not exceed

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lobes; a pair of suction headers are with these two groups of engine cylinders connected and an exhaust manifold is connected to the engine cylinders. For the impulse charge is a pair of first Sarunel tubes provided, which is connected to the intake manifold are and a second collecting pipe, which is connected to the first collecting line. For turbo charging a turbine is provided that connects to the exhaust manifold is connected and a compressor which is connected to the second manifold. The impulse charge and the Turbocharging each have their own speed ranges of greatest volumetric efficiency. The first collecting ' Lines are curved in the area of the connection to the second collecting lines, the radius of curvature the inner wall is R and the inner diameter of the pipe along the curve D. The radius of curvature R and the inner diameter D is related to one another in the relationship R / D <i 0.05.

Below is an embodiment of the invention described in detail with reference to the drawing. Hereby:

Fig. 1 is a schematic representation of an Explosior.smotores with conventional impulse charging;

Fig. 2 is a representation of an explosion engine another type of conventional pulse charging;

3 shows an illustration of an internal combustion engine with a conventional combination of Turbo and impulse charging;

4 shows an illustration of an internal combustion engine

with a combination of turbo and pulse charging according to the present invention;

'Fig. 5 the characteristic dependencies between

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the volumetric efficiency and the Speed of the motor according to the invention;

Fig. 6 is a partial view of the connector

the tubes in an engine according to FIG. 4; and

7 shows a characteristic curve for the dependence between the volumetric efficiency and the quotient from the radius of curvature and the pipe diameter according to FIG. 6.

The invention is described below on the basis of a diesel engine described, but it is understood that the invention Combination of turbo and pulse charging can also be used in a corresponding manner according to the invention in gasoline engines is. ■

Turbochargers have a turbine that can be driven by the exhaust gas and a compressor that is driven by the Turbine is driven to bring air into the engine cylinder at a pressure higher than atmospheric pressure to press. Turbocharging alone does not succeed in increasing the volumetric efficiency sufficiently, since the latter tends to drop outside the tuning range of the turbocharger. On the other hand is the "impulse charging." roughly divided into two groups. With one type of impulse charging, an air intake oscillation is added used to initiate a pressure wave into the engine cylinder immediately before the intake valve closes. at The other type of impulse charging uses the moment of inertia of the air mass in the intake line to Forcing air into the engine cylinder. This inertia effect is basically nothing more than a pressure wave, those in the immediate vicinity of the Ansaua inlet

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works and the effect can be seen from the point of view of a Vibration of the air column in the air intake pipe considered will.

In Fig. 1 is an engine with conventional impulse charging shown. The six cylinders of the explosion engine 1 are divided into two groups, the air intake strokes of which do not overlap, correspondingly, two / intake lines with branches 2A, 2B lead to the groups of cylinders. The suction lines 2A, 2B are connected to a damping chamber 3, which in turn is connected to a single manifold 4 is connected. In this prior art arrangement, the air mass oscillates in each of the intake ducts 2A, 2B and the Damping chamber 3 serves as an open end for both intake line systems 2A, 2B, the damping chamber 3 has a large volume. Since the damping chamber 3 is heavy and takes up a large space, there is a need To create impulse superchargers that do not require such a damping chamber.

To meet this need, an arrangement was made in accordance with 2 proposed, in which two intake systems 12A, 12B are used together, their end sections extend parallel to each other and are combined to form a single tube 13, the cross-sectional area in the essentially the total cross-sectional area of the intake systems 12A, 12B corresponds. The pipe 13 is intended as a damping chamber works.

In the arrangements shown in FIGS. 1 and 2, the air columns in the line systems 2A, 2B, 12A, 12B periodically accelerated when opening the suction valves and thus caused to vibrate, with each column of air has its own resonance frequency. A maximum of air

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suction into the engine cylinder occurs when the resonance frequency coincides with the opening frequency of the inlet valves, the latter depending on the engine speed. Accordingly, the volumetric efficiency reaches its maximum when the engine speed reaches a certain level Value reached, while the efficiency decreases at other speeds.

Fig. 3 shows another known device according to JP-PS 57-2892. This device has resonance tubes 21 and Resonanζkammern 22, the arrangement being made is that the air pressure in the Resonanζkammer 22 increases is to get a larger amount of air into the engine cylinder 23 to press. As described in JP-PS 57-2892, the air columns in the resonance pipes 21 vibrate and have a single resonance frequency when the resonance chambers 22 have a relatively large volume. Included pressure waves run back to the resonance chambers 22 as soon as the engine speed is greater than the tuning range, whereby the volumetric efficiency is prevented from becoming smaller than when normal air is drawn in, although the Inertia effect is more or less reduced. In the engine of FIG. 3, a pulse supercharging is at low Engine speeds used, while at higher engine speeds a turbo charge is provided as well as overall a combination of both types of cargo. The resonance chambers 22 and the further chamber 24, however, require one large weight and volume of the entire assembly, which is obviously a disadvantage.

Fig. 4 shows a combination according to the invention of one Impulse charging and a turbo charging.

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The explosion engine 31 has six cylinders, which are divided into two groups, their suction strokes do not overlap. The cylinder groups are each connected to line systems 32A, 32B, which header pipes 33A and 33B, which converge to form a single manifold 34. The manifold 34 is over an intercooler 41 is connected to the compressor 36 of a turbocharger 35 which has a turbine 37, into which the exhaust gas from the exhaust pipe system 38 is introduced.

The headers 33A, 33B are still through a bypass pipe 39 connected to one another, which is opened or closed by means of a valve 40 arranged therein can be.

The impulse charging takes place in the motor 31 as follows: When the engine 31 rotates at a high speed, the turbocharger 35 becomes effective to feed air into the engine cylinders press. If the machine 31 rotates in the low or medium speed range, impulse charging takes place Forcing air into the engine cylinders. When valve 40 is closed, the impulse charging takes effect at low speeds, since the oscillation frequency of the pipe line system downstream of the collecting pipe 34 is low. When the Valve 40 swings the air in the line system downstream of the bypass pipe 39, which results in a higher resonance frequency, so that impulse charging also occurs is effective in the medium speed range. The intercooler 41 serves to control the temperature of the intake air which was compressed by the compressor 36 to increase the volumetric efficiency. The intercooler 41 can, however, also be dispensed with.

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Fig. 5 illustrates the results when the engine is operated. The volumetric efficiency <Ύ is specified on the vertical axis, while the horizontal axis is calibrated in speed units. Curve A shows the engine operation under the effect of the turbocharger 35, curve B the engine operation with the valve 40 open in the secondary line 39, and curve C the engine operation with the valve 40 closed.

The arrangement according to FIG. 4 is advantageous in that no large-volume chamber is required in the air intake line system is; so that the overall structure is relatively light in weight and in a relatively small space occupies. The secondary line 39 with the valve 40 provided therein enables the intake line system optionally has two different resonance frequencies to increase the volumetric efficiency of the engine.

In the case of impulse charging, there is usually an analysis aer vibrations in the pipe system and an experimental adaptation of the same are necessary. By calculations alone it was not possible to construct complete piping systems.

In the construction of the coupling between the line pipes 33A, 33B and the collecting pipe 34 as shown in FIG The following characteristics were found:

According to FIG. 6, the end sections of the parallel manifolds 33A and 33B are connected by means of a coupling 42 connected to the manifold 34. This coupling 42 is C-shaped and with its legs ir.it the collecting pipes 33a and 3 3B connected, while the manifold 3 4 with the

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Center of the arc of the C-shaped coupling 4 2 connected is. The pipe of the coupling 4 2 has the same diameter D as the headers 33A and 33B. The inside, curved wall of the coupling 4 2 is defined by the radius R of curvature. It was found that when the radius of curvature R is varied, the volumetric efficiency can be improved. The volumetric The efficiency has been improved in the area in which the pulse charging is effective while no significant increase in volumetric efficiency was achieved in the tuning range in which the turbocharger is effective. In other words, "the radius of curvature R influences the momentum charge," but no significant influence on the turbo charge.

7 shows the functional relationship E between the volumetric efficiency ⁷⁷ Ly and the quotient R / D, the volumetric efficiency being marked on the vertical axis, the quotient R / D being marked on the horizontal axis and R the radius of curvature of the inner wall of the Connector of the conduits and D is the inner diameter of each of the conduits 33A, 33B along the bend arrangement. The characteristic see curve E rises steeply at R / D = 0, and becomes less steep as soon as the value R / D = 0.05. At R / D = 0.1 the curve becomes flat. The volumetric efficiency - \ ^ remains substantially unchanged, when the ratio R / D is greater than 0.1.

The reasons for this characteristic curve shape are explained below.

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The impulse charging is closely related to the resonance frequency in the suction line system and changes into Dependence on how far the pipe system is viewed as a uniform vibration carrier can be. For values of R / D = 0.05 or more, the connection of the pipes 33A and 33B appears as a single one Pipe system, whereby the volume of the amount of air introduced into one of the two lines 33A or 33B corresponds to the total volume corresponds to the air coming from the manifold 34 and the other of the two manifolds 33A and 33B was fed. For example, the air fed into pipe 33A comes from pipes 33B and 34, while the air fed into the pipe 33B comes from the pipes 33A and 34, respectively. Accordingly a larger amount of air is introduced compared to conventional systems, i.e. a larger air mass is moved, which leads to the increase in volumetric efficiency.

These affect the effectiveness of the impulse charging Factors were obtained based on experimental results, which is a theoretical analysis of the data still required.

In particular, the impulse charging is related to the suction piping system influenced by the following factors: The length L of the suction line system, the cross-section F. of the suction line system and the resistance, u for the air flow in the suction line system.

The construction of the coupling between the manifolds 33A, 33B and the manifold 34 affects the impulse charging and the resistance , n, for the air flow im

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Suction piping system is seen as a determining factor. The latter changes with the ratio R / D and determines the volumetric efficiency. The flow resistance .u is used to increase the volumetric efficiency over the entire speed range of the Engine. In general, it can be said that the lower the flow velocity, the lower the flow resistance is. · ·

The advantageous effect of the value of the quotient R / D chosen here presumably follows from the two resonance frequencies, the low flow resistance and other, unknown causes.

The present invention is thus the result of more experimental work Attempts and a complete theoretical penetration of the problems are still pending.

According to the present invention, pulse charging and the turbocharging is combined with one another, with the impulse charging remaining effective in two or more tuning ranges, so that the volumetric efficiency is increased overall.

Since the turbocharger is preferably effective at high speeds and the impulse supercharger at low speeds is used, both the exhaust gases and the inertia effects are used effectively.

If the value R / D = 0.1 or greater, the volumetric efficiency remains essentially unchanged, see above that in this area the aforementioned value can be determined quite freely in order to meet the special design requirements to meet.

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HXM 1436 List of Reference Numbers

52 32A, 32B, Ansauq tube 32 ? - '33A, 3 3B, collective line 53 3 ¹ * collective line * 4 3? turbocharger ² '5 36 compressor 56 57 turbine 37 33 Exhaust manifold 58 39 secondary line 59 ^ O valve 40 41 41 42 coupling 42 Zt ^ 45 44 Hy 45 45 ^ 6 47 47 ZlC 45 49 '+9 50 50 51 51 52 52 55 55 54 54 SS 55 56 56 R7 57 53 ■. 55 S3 59 60 60 61 - "" Λ
O: 62 62 65 A * 64 64 65 65

ORIGlMAL INSPECTED

Claims (7)

Expectations h / multi-cylinder internal combustion engine, characterized in that the engine cylinders are divided into two groups, the intake strokes of which do not overlap; that a pair of suction pipes. (32A, 32B) are connected with branches to said groups of engine cylinders, respectively; that a pulse supercharger having a pair of first manifolds (33A, 33B) is respectively connected to the suction pipes (32A, 32B) with branches and that a single manifold (34) is connected to the first manifolds (33A, 33B); that an exhaust manifold (38) is connected to the engine cylinders; that a turbocharger (35) with a turbine (37) is connected to the exhaust manifold (38) and that a compressor (36) is connected to the second manifold (34), wherein the impulse supercharger and the turbocharger (35 ) have different speed ranges in which they increase the volumetric efficiency of the engine; and that said first manifolds (33A, 33B) in the area of their connection to the second manifold (34) are curved in an arc shape with a radius of curvature R of the inner wall and a diameter D of the pipes in the area of curvature, where the quotient R / D of the condition R / D > _ 0.05 is sufficient. r ce acre η. "YKi · Ο O 1 / Ω -ι 1 - 2 - 2. Multi-cylinder internal combustion engine according to claim 1, characterized characterized in that a secondary line (39) is provided which connects the first collecting lines (33A, 33B) connects with each other and has a valve (40). 3. Multi-cylinder internal combustion engine, characterized in that the engine cylinders are divided into two groups, whose suction strokes do not overlap; that an exhaust pipe system connected to the cylinders; that a pair of suction line systems (32A, 32B) with the two groups of cylinders are connected; that pulse charging devices connected to the suction lines (32A, 32B) to increase the volumetric efficiency to increase the engine in a first speed range, the devices for pulse charging a pair of first headers (33A, 33B), each of which having an end portion of said Suction lines (32A, 32B) are connected as well as a second, single manifold (34) to the pair of first busses (33A, 33B) is connected; that the pulse charging devices are tubular Coupling for connecting the first collecting lines (33A, 33B) to the second collecting line (34), wherein the tubular coupling (42) has an inside tube diameter D and is C-shaped in the manner of an arch is, the free legs of which are each connected to the end sections of said first collecting lines (33A, 33B) are connected, while the second collecting line (34) with the center of the C-shaped coupling piece (42) is connected and that the radius of curvature of the between the first manifolds (33A, 33B) extending Inner wall R and diameter D form a quotient which is equal to or greater than 0.05; and that a Turbocharger connected to the second manifold (34) BOE ₄ HMERTS ₄ ESOSFiMERi - .. '· 3 3 H 9 1 1 is to measure the volumetric efficiency of the engine in to increase a second speed range, which differs from the first speed range, wherein the Turbocharger has a turbine (37) which is connected to the exhaust line system (38) and a Compressor (36) which is connected to the second manifold (34). 4. Motor according to claim 3, characterized in that the end portions of the first manifolds (33A, 33B) in the Area of the coupling (42) run essentially parallel and occupy a distance from one another which is in the is substantially equal to twice the radius of curvature (R), the first manifolds (33A, 33B) the Have inner diameter D and the second collecting line (34) with the apex of the C-shaped coupling (42) connected is. 5. Motor according to claim 4, characterized in that a secondary line (39) between the pair of first Manifolds (33A, 33B) is provided downstream of the coupling (42), which by means of a valve (40) to open or close. 6. Multi-cylinder internal combustion engine, characterized in that that the engine cylinders are divided into two groups whose intake strokes do not overlap; that an exhaust pipe system connected to the cylinders; that a pair of suction line systems (32A, 32B) each with one of the group of cylinders is connected; that means for impulse charging with the suction pipe system (32A, 32B) is connected to the volumetric efficiency of the engine in a first speed range to enlarge, with the facilities for impulse charging a pair of first bus lines (33A, 33B) comprise _t of each of the intake manifolds (32A, 32B) is connected to one end and a single, second manifold (34) connected to the pair of first bus lines (33A, 33B ) connected is; that the devices for impulse charging have a tubular coupling (42) for connecting the first collecting lines (33A, 33B) to the second collecting line (34), which (coupling) has an inner tube diameter D and is C-shaped in the manner of an arc is, the legs of which are each connected to the end sections of the first manifolds (33A, 33B), while the second manifold (34) is connected to the apex of the C-shaped coupling (42) approximately in the middle, the C-shaped coupling - ■ treatment has an inner, curved wall which extends between the pair of first manifolds (33A, 33B) and is defined by the radius of curvature R; and that a turbocharger (35) is provided which is connected to the second manifold (34) to increase the volumetric efficiency of the engine in a second speed range which is different from the first speed range, the turbocharger having a turbine (37) which is connected to the exhaust pipe system, while its compressor (36) is connected to the second manifold (34). 7. Motor according to claim 6, characterized in that the end portions of the first manifolds (33A, 33B) run essentially parallel in the region of the coupling (42) and occupy a distance from one another which is essentially equal to twice the radius of curvature (R), the first collecting lines (33A, 33B) also have the inner diameter D and the second Manifold (34) is connected to the apex of the coupling (42) on its outer wall.