EP2077385B1 - Cylinder head for a combustion engine with bordering component - Google Patents

Description

• jeder Zylinder mindestens zwei Auslaßöffnungen zum Abführen der Abgase aus dem Zylinder aufweist,
• sich an jede Auslaßöffnung eine Abgasleitung anschließt, und
• die Abgasleitungen unter Ausbildung eines Abgaskrümmers zu einer Gesamtabgasleitung zusammenführen, wobei der Abgaskrümmer zumindest teilweise im Zylinderkopf integriert ist, und
• eine Leitung zur Rückführung von Abgas vorgesehen ist, die von dem Abgaskrümmer innerhalb des Zylinderkopfes abzweigt und durch den Zylinderkopf und das mindestens eine an den Zylinderkopf angrenzende Bauteil hindurchführt.

The invention relates to a cylinder head with an at least partially integrated in the cylinder head coolant jacket and at least one adjacent to the cylinder head component for an internal combustion engine having at least two cylinders, in which

• each cylinder has at least two exhaust ports for exhausting the exhaust gases from the cylinder,
• is connected to each outlet an exhaust pipe, and
• the exhaust pipes merge to form an exhaust manifold to form an exhaust manifold, wherein the exhaust manifold is at least partially integrated in the cylinder head, and
• a conduit for recirculating exhaust gas is provided which branches off from the exhaust manifold inside the cylinder head and passes through the cylinder head and the at least one component adjacent to the cylinder head.

Such an internal combustion engine describes, for example, the German patent application DE 100 62 169 A1 ,

Internal combustion engines have a cylinder block and a cylinder head, which are used to form the individual cylinders, i. Combustion chambers are interconnected. At the cylinder head and / or the cylinder block border a plurality of components d. H. Aggregates that perform a required for the operation of the internal combustion engine task.

The cylinder block has a corresponding number of cylinder bores for receiving the pistons or the cylinder tubes. The pistons are guided axially movably in the cylinder tubes and, together with the cylinder tubes and the cylinder head, form the combustion chambers of the internal combustion engine.

The cylinder head is often used to hold the valve train. In order to control the charge cycle, an internal combustion engine requires control means and actuators to operate these controls. As part of the change of charge the pushing out takes place the combustion gases through the outlet openings and the filling of the combustion chamber that is the suction of the fresh mixture or the fresh air through the inlet openings. To control the charge cycle four-stroke engines almost exclusively lift valves are used as control members that perform an oscillating lifting movement during operation of the internal combustion engine and thus release the inlet and outlet ports and close. The required for the movement of the valves valve actuating mechanism including the valves themselves is referred to as a valve train.

It is the task of the valvetrain to release the intake and exhaust ports of the combustion chamber in time or to close, with a quick release of the largest possible flow cross sections is sought to keep the throttle losses in the incoming and outflowing gas flows low and the best possible filling the combustion chamber with fresh mixture or an effective d. H. To ensure complete removal of the exhaust gases. Therefore, according to the prior art, two or more intake and exhaust ports are increasingly being provided as well as the cylinder head which is the subject of the present invention.

The inlet ducts leading to the inlet openings and the outlet ducts or exhaust ducts adjoining the outlet openings are at least partially integrated in the cylinder head according to the prior art. The exhaust pipes of the at least two exhaust ports of a single cylinder are often - within the cylinder head - merged into a cylinder associated partial exhaust gas line, these partial exhaust gas lines are then combined outside the cylinder to form a single overall exhaust line. The merging of the exhaust pipes to the entire exhaust line is referred to in general and in the context of the present invention as exhaust manifold or manifold.

Downstream of the manifold, the exhaust gases are then optionally supplied to the turbine of an exhaust gas turbocharger and / or one or more exhaust aftertreatment systems.

In addition, internal combustion engines are increasingly equipped with an exhaust gas recirculation, the line for returning the exhaust gas d. H. The return line usually branches off from the overall exhaust line downstream of or upstream of an exhaust gas aftertreatment system provided in the exhaust line, and downstream or upstream of a turbine of an exhaust gas turbocharger.

The exhaust gas recirculation, ie the recirculation of combustion gases from the exhaust gas side to the intake side of the internal combustion engine, is a measure to comply with future limit values for pollutant emissions, in particular the limit values for nitrogen oxide emissions. Since the formation of nitrogen oxides not only an excess of air, but also high temperatures A concept for reducing nitrogen oxide emissions is to develop combustion processes with lower combustion temperatures, where exhaust gas recirculation is a means of lowering temperatures.

wobei m_AGR die Masse an zurückgeführtem Abgas und m_Frischluft die zugeführte und gegebenenfalls komprimierte Frischluft bzw. Ladeluft bezeichnet.With increasing exhaust gas recirculation rate, the nitrogen oxide emissions can be significantly reduced. The exhaust gas recirculation rate X _{EGR is} determined as follows: $${\mathrm{x}}_{\mathrm{AGR}}\mathrm{=}{\mathrm{m}}_{\mathrm{AGR}}\mathrm{/}\left({\mathrm{m}}_{\mathrm{AGR}}\mathrm{+}{\mathrm{m}}_{\mathrm{fresh\; air}}\right)$$

where m _AGR the mass of recirculated exhaust gas and m _fresh air refers to the supplied and optionally compressed fresh air or charge air.

Exhaust gas recirculation is also suitable for reducing emissions of unburned hydrocarbons in the partial load range.

In order to achieve a significant reduction in nitrogen oxide emissions, high exhaust gas recirculation rates are required, which can be on the order of X _AGR ≈ 50% to 70%.

If the exhaust gas is branched off downstream of the exhaust manifold outside of the cylinder head, the tapping point for exhaust gas recirculation is arranged outside of the cylinder head. The return line must be connected to the entire exhaust line, for example by means of a flange connection. The joint is on the one hand a potential leakage point for the unwanted escape of exhaust gases, which implies high demands on the seal. On the other hand, this connection is thermally highly loaded by the hot exhaust gases, so that high demands are placed on the execution of the connection. If the entire exhaust line made of high temperature resistant material, the compound must also be made of costly and difficult to process material.

However, the prior art also includes concepts in which the Abgriffsstelle is integrated for exhaust gas recirculation in the cylinder head. The integrated into the cylinder head tapping point allows the one-piece design of manifold and return line ie the avoidance of training and thus the sealing of a non-positive connection point. Furthermore, the integration of the tapping point leads to a reduction in the number of components and to a more compact design. The latter also supports the effort to achieve as dense as possible a packaging of the drive unit in the engine compartment.

A cylinder head with a built-in cylinder head tapping point for exhaust gas recirculation describes, for example, the GB 2 370 073 A , The return line branches off from a partial exhaust gas line of a cylinder with two outlet openings, wherein the first portion of the return line is employed against the flow direction of the exhaust gas in the partial exhaust gas line used for branching, thus making it more difficult for exhaust gas to flow out of the associated cylinder.

For the formation of this section also a special casting core must be provided, since according to the GB 2 370 073 A the entire return line extends within the cylinder head and this section can not be formed in any other way, which makes the production difficult. In order to integrate the return line completely in the cylinder head, the cylinder head must also have the necessary material substance, which usually leads to an increase in weight. On the other hand, the complete integration of the return line leads to a comparatively small volume of the return line and thus to a good response of the EGR.

Against the background of the above, it is the object of the present invention to provide a cylinder head according to the preamble of claim 1, which is equipped with a built-in cylinder head tapping point for exhaust gas recirculation and in particular has a compact design with relatively low production costs.

• jeder Zylinder mindestens zwei Auslaßöffnungen zum Abführen der Abgase aus dem Zylinder aufweist,
• sich an jede Auslaßöffnung eine Abgasleitung anschließt, und
• die Abgasleitungen unter Ausbildung eines Abgaskrümmers zu einer Gesamtabgasleitung zusammenführen, wobei der Abgaskrümmer zumindest teilweise im Zylinderkopf integriert ist, und
• eine Leitung zur Rückführung von Abgas vorgesehen ist, die von dem Abgaskrümmer innerhalb des Zylinderkopfes abzweigt und durch den Zylinderkopf und das mindestens eine an den Zylinderkopf angrenzende Bauteil hindurchführt,
  und der dadurch gekennzeichnet ist, dass
• das angrenzende Bauteil eine Flüssigkeitskühlung aufweist, die vorzugsweise mit dem zumindest teilweise im Zylinderkopf integrierten Kühlmittelmantel kommuniziert.

This object is achieved by a cylinder head with an integrated at least partially in the cylinder head coolant jacket and with at least one adjacent to the cylinder head component for an internal combustion engine with at least two cylinders, in which

• each cylinder has at least two exhaust ports for exhausting the exhaust gases from the cylinder,
• is connected to each outlet an exhaust pipe, and
• the exhaust pipes merge to form an exhaust manifold to form an exhaust manifold, wherein the exhaust manifold is at least partially integrated in the cylinder head, and
• a conduit is provided for the recirculation of exhaust gas, which branches off from the exhaust manifold inside the cylinder head and passes through the cylinder head and the at least one component adjacent to the cylinder head,
  and which is characterized in that
• the adjacent component has a liquid cooling, which preferably communicates with the at least partially integrated in the cylinder head coolant jacket.

The cylinder head according to the invention has as in the GB 2 370 073 A described cylinder head via a built-in cylinder head tapping point for exhaust gas recirculation and thus consequently also on all the benefits that result from such a trained and arranged tap. In particular, the use of the cylinder head according to the invention allows a compact design of the internal combustion engine, the reduction of the required components and the prevention of Abgasleckagestroms. The inventive route of the return line also leads to a good response of the EGR, since a comparatively short return line can be realized.

In contrast to the cylinder head according to the GB 2 370 073 A but does not run the entire return line in the cylinder head. Rather, the return line leads only partially through the cylinder head, but in addition also by at least one adjacent to the cylinder head component.

As a component adjacent to the cylinder head, in the context of the present invention, any component is considered which adjoins the cylinder head without spacing or indirectly-for example, only separated by a gasket-ie adjoins, is connected to the cylinder head and already - in addition to receiving the return line according to the invention at least one further function, ie task with respect to the operation of the Internal combustion engine arrives. In this respect, the invention does not require an additional component and connected to the cylinder head, only to integrate the return line in this, but already existing and already for the operation of the Internal combustion engine required component used for partially receiving the return line.

Thus, eliminates all the disadvantages associated with a complete integration of the entire return line in the cylinder head, such as the weight increase of the drive unit due to the requirement of a voluminous and heavier cylinder head. In particular, the costs can be reduced. While in the complete integration of the return line in the cylinder head, the manufacturing cost - for the reasons already mentioned above - are high, causes the inventive approach d. H. the partial integration of the return line in an adjacent component only little or no additional costs. This is also due to the fact that in a component adjacent to the cylinder head is often a diecast part, in which an additional line can be easily introduced.

With the cylinder head according to the invention, the object underlying the invention is thus achieved, namely to provide a cylinder head with integrated Abgriffsstelle for exhaust gas recirculation, which has a compact design with low production costs.

Due to the fact that the return line according to the invention is passed through an adjacent component, the return line must, in principle, and in contrast to that in the GB 2 370 073 A leaked cylinder head from the cylinder head, which not only considerably simplifies the production of branching off of the manifold and arranged in the cylinder head portion of the return line, but also creates more freedom in training ie design of this section of the return line.

Thus, the return line - depending on the individual case - partially or completely be introduced by means of machining production process in the cylinder head.

The return line can also be partially or completely formed already during the casting of the cylinder head blank, which can be done by introducing a simple, outwardly open and therefore easily removable core. Part of the return line can also formed during casting of the cylinder head blank, wherein the complete return line is formed only by a post-processing.

Basically, the length of the return line decreases with the integration of the tapping point in the cylinder head, whereby the volume of the return line decreases, so that the response of the exhaust gas recirculation improves.

In the case of the cylinder head according to the invention, the adjoining component has liquid cooling, which preferably communicates with the coolant jacket integrated at least partially in the cylinder head. The liquid cooling provided in the adjacent component cools the exhaust gas passed through the return line or the component.

The lowering of the temperature in the recirculated hot exhaust gas flow increases the density of the exhaust gases. The temperature of the cylinder fresh charge, which occurs in the mixture of fresh air with the recirculated exhaust gases, is consequently also reduced, which contributes to a better filling of the combustion chamber with fresh mixture. By increasing the density, the volume is reduced, resulting in a decrease in flow losses. In addition, a downstream provided EGR valve is thermally less heavily loaded, so that optionally can be dispensed with a cooling of the EGR valve or less temperature-resistant and thus cheaper materials for the production of the valve can be used.

Further advantageous embodiments of the cylinder head are discussed in connection with the subclaims.

Embodiments of the cylinder head in which the exhaust manifold is completely integrated in the cylinder head are advantageous. This embodiment of the manifold or the cylinder head contributes to the solution of the problem underlying the invention, namely to realize a compact design of the cylinder head.

If, in addition, the turbine of an exhaust-gas turbocharger and / or an exhaust-gas aftertreatment system are arranged in the overall exhaust gas line, further substantial advantages result.

In principle, one endeavors to arrange a turbine as close as possible to the outlet of the internal combustion engine in order to be able to optimally use the exhaust enthalpy of the hot exhaust gases in this way and to ensure a rapid response of the turbocharger. Also, the way the hot exhaust gases to the various exhaust aftertreatment systems should be as short as possible, so that the exhaust gases are given little time to cool and the exhaust aftertreatment systems reach their operating temperature or light-off as soon as possible, especially after a cold start of the engine.

This can be achieved by minimizing the thermal inertia of the exhaust pipe section between the exhaust port on the cylinder and the exhaust aftertreatment system and exhaust port on the cylinder and turbine respectively, which can be achieved by reducing the mass and length of that section, including complete integration of the exhaust manifold in the cylinder head. The total travel distance of the exhaust pipes of the exhaust manifold is considerably shortened by the integration.

In addition, a cylinder head with fully integrated exhaust manifold due to the high thermal load on a comparatively bulky coolant jacket, which can also be used for cooling the exhaust gas passed through the return line - with the advantages already mentioned above.

Due to the shorter flow paths in the fully integrated exhaust manifold, the return line for the exhaust gas streams of all cylinders is comparatively easily accessible. This leads advantageously to the fact that the recirculation branching off from the manifold can be acted upon or acted upon by the exhaust gas of all cylinders of the internal combustion engine, which is also required for generating high recirculation rates, since the exhaust gas of a single cylinder or a single outlet port of a Multi-cylinder internal combustion engine is not enough.

Advantageous embodiments of the cylinder head, in which first the exhaust gas lines of the at least two outlet openings of each cylinder to a cylinder merge associated partial exhaust gas line before merge these partial exhaust gas lines of the at least two cylinders to the total exhaust gas line.

In turn, embodiments of the cylinder head in which the line for returning exhaust gas branches off from a partial exhaust gas line are advantageous.

This embodiment of the cylinder head according to the invention differs from concepts in which the return line branches off from the entire exhaust line or an exhaust pipe of a single outlet opening.

In the latter variant, a much more pronounced backflow of the exhaust components discharged from the other outlet openings would be required, which, however, does not occur or can not be achieved in practice in this way, so that high return rates with such a concept are not or only with difficulty realized could. In addition, a strong pulsation in the return line would be observed, since the return line would be acted upon substantially only with the exhaust gas of a single outlet opening.

On the other hand, the removal of the exhaust gas from the entire exhaust gas line would significantly increase the travel distance of the return line to be integrated into the cylinder head or complicate the routing of this return line. If necessary, this would require a considerable increase in the weight of the cylinder head d. H. cause.

Embodiments of the cylinder head in which the line integrated in the cylinder head for the return of exhaust gas runs in a straight line are advantageous. The rectilinear design of this section of the return line simplifies the production of the line considerably. A rectilinear return line can be formed for example in a simple manner by drilling.

In addition, a rectilinear course can serve to shorten the length of the return line and thus to reduce the volume of the line, which improves the response of the exhaust gas recirculation.

Embodiments of the cylinder head in which the line integrated in the cylinder head for returning exhaust gas runs essentially parallel to the longitudinal axis of the cylinder head are advantageous. The return line usually connects laterally to the exhaust manifold and is not guided in the direction of the cylinder longitudinal axis up or down.

It is advantageous if the line integrated in the cylinder head for the return of exhaust gas to form a funnel-shaped inlet region connects to the manifold or the partial exhaust gas line. In this embodiment, the diameter of the return line at the junction increases in the direction of the manifold, so that a funnel-shaped inlet region is formed, which promotes the influx of exhaust gas.

Advantageously, sharp edges, where the exhaust gas flow breaks off or swirls, are avoided. For this reason, embodiments of the cylinder head are advantageous in which the walls of the integrated return line in the cylinder head to buckle to form the funnel-shaped inlet region, whereby a trumpet-shaped inlet region is formed. An entrance area that widens towards the bend also reduces the pulsation.

Embodiments of the cylinder head in which the return line connects to the outside of the exhaust manifold are advantageous. This embodiment is advantageous because the cylinder head in this way only slightly by the introduction of. the integration of the return line is weakened or affected. In particular, the length of the return line is shortened, whereby the volume of the line is reduced, which - as already stated above - improves the response of the exhaust gas recirculation. Such a running return line also limits the interpretation of the cylinder head construction with respect to other requirements or functions as little as possible.

It should be noted in this context, in particular, that the cylinder head is anyway a thermally and mechanically highly loaded component, since the cylinder head already have a variety of tasks and functions. Thus, the cylinder head not only takes the valve train - as already described above - but also includes the Holes in which the bolts are introduced for connecting the cylinder head with the cylinder block. Optionally, additional lines for venting the crankcase are provided in the cylinder head.

In addition, a cylinder head with integrated exhaust manifold - as already mentioned - due to the high thermal load on a relatively bulky coolant jacket.

Against this background, it is thus advantageous if the return line integrated in the cylinder head has the smallest possible volume, which can be realized for example by the external connection of the return line to the exhaust manifold.

For the same reasons, embodiments are also advantageous in internal combustion engine with three and more cylinders, in which the return line branches off from the manifold in the region of an outer cylinder.

Furthermore, embodiments of the cylinder head in which the coolant jacket integrated in the cylinder head at least partially surrounds the return line are advantageous.

In this way, the exhaust branched off from the exhaust manifold, provided for a return exhaust gas is already cooled in the cylinder head. The thermal load of a downstream of the return line and downstream of the branch valve provided for controlling the return rate (EGR valve) decreases. With regard to the EGR valve, reference is made to the statements already made above. An optionally provided additional radiator for cooling the recirculated exhaust gas may under certain circumstances be dimensioned smaller or completely eliminated.

Embodiments of the cylinder head in which the line for returning exhaust gas leaves the cylinder head and enters directly into the at least one component adjacent to the cylinder head are advantageous.

Unlike embodiments in which the return line exits the cylinder head and downstream of the cylinder head again into the adjacent component enters the exit from the cylinder head in the present embodiment at the same time the entry into the adjacent component, so that no additional line pieces are required.

Embodiments of the cylinder head are advantageous in which the at least one component adjacent to the cylinder head is a coolant housing which serves to supply coolant to the coolant jacket integrated in the cylinder head and / or to discharge coolant from the coolant jacket integrated in the cylinder head, for example a water outlet housing.

Advantageously, the walls of the adjacent component which form the liquid cooling system are formed as large as possible in order to increase the heat transfer by convection, which can be done for example by the arrangement of cooling fins. The same applies to the walls of the integrated in the cylinder head coolant jacket.

Embodiments of the cylinder head in which the line for returning exhaust gas leaves the at least one component adjoining the cylinder head are advantageous. The return line can be routed downstream of the outlet to an additional cooler and from there or directly from the component to the inlet side of the internal combustion engine, for example, to a designated on the inlet side reservoir, called plenum.

Embodiments of the cylinder head in which a valve for controlling the return rate is provided in the line for recirculating exhaust gas are advantageous.

Both embodiments of the cylinder head, in which the valve is arranged between the cylinder head and the at least one component adjacent to the cylinder head, as well as embodiments in which the valve is integrated into the at least one component adjacent to the cylinder head, are advantageous.

In the last-mentioned embodiment, the valve can either be introduced into the component in such a way that it is at least partially or completely detached from the component is encased, or connect externally to the adjacent component, wherein a connection of the component and valve can be realized by means of flange connection. In this case, the exhaust gas to be recirculated flows from the component into the EGR valve, through the valve and optionally back into the component again, in which it is preferably cooled again when the component is again flowed through.

The valve can also be fully or partially integrated into the cylinder head.

Advantageously, the use of a cylinder head according to one of the aforementioned types, in particular in a supercharged internal combustion engine, since the exhaust gas recirculation and charging are often used in combination and a supercharged internal combustion engine is charged thermally higher.

Due to the cooling of the exhaust manifold and the return line in the cylinder head can be dispensed with the use of costly heat-resistant materials. This is due to the high exhaust gas temperatures, especially in supercharged internal combustion engines of relevance or advantage.

In addition, the dimensioning d. H. Determining the length of the exhaust ducts in supercharged internal combustion engines with respect to the combustion process of lesser importance than uncharged internal combustion engines, so that in turbocharged internal combustion engines, the generally short length of the at least partially integrated in the cylinder head manifold has no negative impact on the performance of the internal combustion engine.

The use of the cylinder head according to the invention is advantageous in particular in internal combustion engines that are charged by turbocharging. In these internal combustion engines, the turbine of an exhaust gas turbocharger is arranged in the overall exhaust line, thereby increasing the exhaust pressure upstream of the turbine and thus also the exhaust pressure in the manifold, which facilitates the introduction of the exhaust gas streams in the return line, so that high return rates can be realized.

Fig. 1

in einer Draufsicht den Gußkern der in einer ersten Ausführungsform des Zylinderkopfes integrierten Abgasleitungen mitsamt dem Gußkern für die integrierte Rückführleitung,

Fig.2

eine zweite Ausführungsform des Zylinderkopfes in einer perspektivischen Darstellung mit Blick auf die Montagestirnseite,

Fig. 3a

ein an den Zylinderkopf angrenzendes Bauteil in einer perspektivischen Darstellung mit Blick auf die Montagestirnseite, und

Fig. 3b

das in Figur 3a dargestellte Bauteil in einer perspektivischen Darstellung mit Blick auf die der Montagestirnseite gegenüberliegende Seite des Bauteils.

In the following the invention with reference to two embodiments according to the Figures 1 to 3b described in more detail. Hereby shows:

Fig. 1

in a plan view of the casting core of the integrated in a first embodiment of the cylinder head exhaust pipes together with the casting core for the integrated return line,

Fig.2

a second embodiment of the cylinder head in a perspective view with a view of the mounting end face,

Fig. 3a

a component adjacent to the cylinder head in a perspective view with a view of the mounting end face, and

Fig. 3b

this in FIG. 3a shown component in a perspective view with a view of the mounting end side opposite side of the component.

FIG. 1 shows in a plan view of the casting core 12 of the integrated in a first embodiment of the cylinder head exhaust pipes 4a, 4b, 5a, 5b, 5c, 6, so that FIG. 1 per se, the system of integrated in the cylinder head exhaust pipes 4a, 4b, 5a, 5b, 5c, 6 itself illustrates or reproduces why the reference numerals for the exhaust pipes 4a, 4b, 5a, 5b, 5c, 6 were registered or used. Shown is also provided in the cylinder head ie integrated line 7 for the return of exhaust gas or the casting core 11 used to form the return line 7.

At the in FIG. 1 illustrated casting core 12 and exhaust system is the exhaust pipes 4a, 4b, 5a, 5b, 5c, 6 of a cylinder head of a three-cylinder in-line engine. Each of the three cylinders 1a, 1b, 1c is provided with two outlet openings 2a, 2b, with an exhaust pipe 4a, 4b for discharging the exhaust gases adjoining each outlet opening 2a, 2b.

The discharge lines 4a, 4b lead together to form an exhaust gas manifold 3 to form an overall exhaust gas line 6. In this case, the exhaust gas lines 4a, 4b of each cylinder 1a, 1b, 1c initially lead to a partial exhaust gas line 5a, 5b, 5c associated with the cylinder 1a, 1b, 1c, whereby these partial exhaust gas lines 5a, 5b, 5c subsequently open downstream into a common total exhaust gas line 6. The exhaust gas leaves the cylinder head at the outlet 9 of the total exhaust line 6 from the cylinder head.

In the cylinder head, a line 7 for the return of exhaust gas is integrated. The return line 7 branches off from the exhaust manifold 3 integrated in the cylinder head, the return line 7 branching off from a partial exhaust line 5a of the manifold 3 and having an outlet 8 from the cylinder head.

At the in FIG. 1 illustrated embodiment, the rectilinear and parallel to the cylinder head longitudinal axis extending return line 7 branches off from the partial exhaust line 5a of an outer cylinder 1a, wherein the line 7 connects externally to the exhaust manifold 3.

The return line 7 connects to form a funnel-shaped inlet region 10 to the partial exhaust gas line 5a. In this case, the diameter of the return line 7 increases at the connection point in the direction of the partial exhaust gas line 5a. The inflow of exhaust gas is thereby simplified and that both the inflow from the cylinder 1 a, from the partial exhaust line 5 a, the return line 7 branches off, as well as the inflow from the other cylinders 1 b, 1 c.

The walls of the return line 7 bulge outwards in the direction of the partial exhaust gas line 5a, so that the inlet region 10 assumes a trumpet-shaped form.

Such a trained inlet region 10, which widens toward the partial exhaust gas line 5a, also leads to a reduction of the pulsation.

FIG. 2 shows a fragment of a second embodiment of the cylinder head 13 in a perspective view with a view of the mounting end face 14a, on which the cylinder head 13 with the in the FIGS. 3a, 3b is shown connected to the component or to this component to the cylinder head 13 connects.

The cylinder head 13 has two return lines 7a ', 7b' open to the assembly end face 14a for the exhaust gas to be recirculated. These cylinder-head-side return lines 7a ', 7b' form part of the complete return lines 7a, 7b, which only in the assembled state from the combination of the cylinder head-side return lines 7a ', 7b' with the These return lines 7a ', 7b' corresponding component-side return lines 7a ", 7b" put together ie result (see also FIGS. 3a and 3b ).

A first return line 7a, 7a 'extends upstream from an EGR valve which is attached to the adjacent component, whereas the second return line 7b, 7b' leads downstream from the EGR valve.

The exhaust gas flow branched off and returned from the exhaust manifold within the cylinder head 13 flows at the inlet A into the return line 7a, 7a 'and leaves this return line 7a, 7a' at the outlet B to pass the EGR valve. After flowing through the EGR valve, this exhaust gas stream enters the second return line 7b, 7b 'at the inlet C, flows through it and leaves the return line 7b, 7b' at the outlet D. In this case, the exhaust gas stream is cooled.

The cylinder head 13 has two cylinder-head-side coolant channels 17a ', 17b', which pierce the mounting end face 14a and pass into the adjacent component.

Furthermore, a line 20 'for venting the crankcase is integrated into the cylinder head 13, which also pierces the mounting end face 14a and merges into the adjacent component.

FIG. 3a shows a contiguous to the cylinder head component 15 in a perspective view of the mounting end face 14b. FIG. 3b shows this component 15 also in a perspective view, but with a view of the mounting end face 14b opposite side of the component 15th

That in the FIGS. 3a, 3b shown Wasserauslaßgehäuse 16 is a according to the cylinder head FIG. 2 adjacent component 15, which adjoins in the assembled state without spacing or indirectly via an intermediate seal to the cylinder head ie connects and is connected to the cylinder head by the mounting end face 14b of the Wasserauslaßgehäuses 16 placed flush on the mounting end face of the cylinder head and bolted. Optionally, a seal is placed therebetween.

In addition to receiving the return line 7a, 7b, the water outlet 16 has the primary task to dissipate the coolant from the cylinder head d. H. to control the coolant drain from the cylinder head.

The water outlet housing 16 has two return lines 7a ", 7b" open to the assembly end face 14b for the exhaust gas to be recirculated. These housing-side return lines 7a ", 7b" form part of the complete return lines 7a, 7b, which are formed only in combination with the cylinder head-side return lines 7a ', 7b' (see also FIG FIG. 2 ). With regard to the flow path of the exhaust gas to be recirculated, reference is made to the statements already made above.

The water outlet housing 16 has two housing-side coolant channels 17a ", 17b", which are open to the mounting end face 14b and connect to the cylinder head side coolant channels.

A water outlet housing 16 integrated line 20 "for venting the crankcase connects to the provided in the cylinder head vent line and pierces the mounting end face 14b.

As FIG. 3b can be removed, the Wasserauslaßgehäuse 16 has a recess 19 for receiving a thermostat. A provided on the housing 16 mounting flange 18 is used to connect an EGR valve. In this case, the exhaust gas to be recirculated flows from the housing 16 at the inlet 18a into the EGR valve, through the valve and at the outlet 18b back into the housing 16, in which it is cooled again when flowing through the second return line 7b.

reference numeral

1a a

cylinder

1b

cylinder

1c

cylinder

2a

outlet

2 B

outlet

3

exhaust manifold

4a

exhaust pipe

4b

exhaust pipe

5a

Part exhaust pipe

5b

Part exhaust pipe

5c

Part exhaust pipe

6

Total exhaust pipe

7

Line for recirculation of exhaust gas, return line

7a

Return line upstream of the EGR valve

7b

Return line downstream of the EGR valve

7a '

Cylinder-head-side return line upstream of the EGR valve

7b '

Cylinder head side return line downstream of the EGR valve

7a "

Component-side return line upstream of the EGR valve

7b "

Component-side return line downstream of the EGR valve

8th

Outlet of the return line from the cylinder head

9

Outlet of the entire exhaust line from the cylinder head

10

entry area

11

Cast core of the return line

12

Cast core of the exhaust manifold

13

cylinder head

14a

Mounting front side of the cylinder head

14b

Mounting end face of the water outlet housing

15

adjacent component

16

water outlet

17a '

Cylinder-head-side coolant passage

17b '

Cylinder-head-side coolant passage

17a "

component-side coolant channel

17b "

component-side coolant channel

18

mounting flange

18a

Inlet EGR valve

18b

Outlet EGR valve

19

recess

20 '

Cylinder-head-side pipe for venting the crankcase

20 "

Component-side line for venting the crankcase

A

Entry into the return line 7a

B

Exit from the return line 7a

C

Entry into the return line 7b

D

Exit from the return line 7b

AGR

Exhaust gas recirculation

Claims (10)

1. Cylinder head (13) having a coolant jacket which is at least partially integrated into the cylinder head (13) and having at least one component (15), which adjoins the cylinder head (13) for an internal combustion engine with at least two cylinders (1a, 1b, 1c), in which

   - each cylinder (1a, 1b, 1c) has at least two outlet openings (2a, 2b) for discharging the exhaust gases out of the cylinder (1a, 1b, 1c),

   - each outlet opening (2a, 2b) is adjoined by an exhaust line (4a, 4b),

   - the exhaust lines (4a, 4b) are merged, so as to form an exhaust manifold (3), to form an overall exhaust line (6), with the exhaust manifold (3) being at least partially integrated in the cylinder head (13), and

   - a line (7, 7a, 7b) for the recirculation of exhaust gas is provided, which line (7, 7a, 7b) branches off from the exhaust manifold (3) within the cylinder head (13) and leads through the cylinder head (13) and the at least one component (15) which adjoins the cylinder head (13),

   characterized in that
   the adjoining component (15) has a liquid-cooling arrangement which preferably communicates with the coolant jacket which is at least partially integrated into the cylinder head (13).
2. Cylinder head (13) according to Claim 1, characterized in that the exhaust manifold (3) is completely integrated in the cylinder head (13).
3. Cylinder head (13) according to one of the preceding claims, characterized in that firstly the exhaust lines (4a, 4b) of the at least two outlet openings (2a, 2b) of each cylinder (1a, 1b, 1c) merge to form a partial exhaust line (5a, 5b, 5c), which is associated with the cylinder (1a, 1b, 1c), before said partial exhaust lines (5a, 5b, 5c) of the at least two cylinders (1a, 1b, 1c) merge to form the overall exhaust line (6).
4. Cylinder head (13) according to Claim 3, characterized in that the line (7, 7a, 7b) for the recirculation of exhaust gas branches off from a partial exhaust line (5a, 5b, 5c).
5. Cylinder head (13) according to one of the preceding claims, characterized in that the line (7, 7a, 7b) for the recirculation of exhaust gas emerges out of the cylinder head (13) and then enters directly into the at least one component (15) which adjoins the cylinder head (13).
6. Cylinder head (13) according to one of the preceding claims, characterized in that the at least one component (15) which adjoins the cylinder head (13) is a coolant housing (16) which serves for supplying coolant into the coolant jacket which is integrated in the cylinder head (13) and/or for discharging coolant out of the coolant jacket which is integrated in the cylinder head (13).
7. Cylinder head (13) according to one of the preceding claims, characterized in that the line (7, 7a, 7b) for the recirculation of exhaust gas emerges out of the at least one component (15) which adjoins the cylinder head (13).
8. Cylinder head (13) according to one of the preceding claims, characterized in that a valve for controlling the recirculation rate is provided in the line (7, 7a, 7b) for the recirculation of exhaust gas.
9. Cylinder head according to Claim 8, characterized in that the valve is arranged between the cylinder head (13) and the at least one component (15) which adjoins the cylinder head (13).
10. Cylinder head (13) according to Claim 8, characterized in that the valve is integrated into the at least one component (15) which adjoins the cylinder head (13).

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