DE112006000986B4 - Cylinder head for a liquid-cooled internal combustion engine - Google Patents

Abstract

Cylinder head (230) for a liquid-cooled internal combustion engine, comprising a cooling chamber arrangement (210) with at least one cooling chamber (210a), which can be fluidly connected to a coolant jacket of a cylinder block connectable to the cylinder head (230) via at least two coolant paths (201, 202) arranged on a longitudinal side per cylinder, each via a transfer opening (204, 205) in a cylinder head sealing surface, wherein a first and second coolant path (201, 202) are arranged on different sides of a transverse engine plane (215) containing a cylinder axis (214), wherein a third coolant path (203) originating from a third transfer opening (206) is arranged at least partially in the region of the transverse engine plane (215), and wherein the third coolant path (203) leads separately from the first and second coolant paths (201, 202) to at least one partial cooling chamber (211) in a thermally stressed region of the cylinder head (230), characterized in that a riser channel (216) leading to an upper section (209) of the cooling chamber arrangement (210) branches off from the third coolant path (203).

Description

The invention relates to a cylinder head for a liquid-cooled internal combustion engine, with a cooling chamber arrangement with at least one cooling chamber, which can be flow-connected to a coolant jacket of a cylinder block connectable to the cylinder head via at least two coolant paths arranged on a longitudinal side per cylinder, each via a transfer opening in the cylinder head sealing surface, wherein a first and second coolant path are arranged on different sides of a transverse engine plane containing a cylinder axis, wherein a third coolant path starting from a third transfer opening is arranged at least partially in the region of the transverse engine plane, and wherein the third coolant path leads, separate from the first and second coolant paths, to at least one partial cooling chamber in a thermally stressed region of the cylinder head.

From the EP 1 387 052 A1 An exhaust system is known. The flow center lines of two merging pipes have an angle of less than or equal to 20°. However, the pipe interiors upstream of the outlet tongue are shaped in such a way that turbulence occurs in the outlet area. This severely disrupts the dynamic behavior of the exhaust flow, which can lead to power losses. A similar internal combustion engine is known from EP 1 342 890 A2 known.

By reference, the contents of the EP 1 363 010 A1 and EP 1 362 996 A1 included.

It is known to design the intake ports separately between the intake flange surface and the intake valves. It is also known to provide a common intake port in the cylinder head for each two intake valves of a cylinder, which only branches off in the region of the valve chamber. Furthermore, cylinder heads with two intake valves per cylinder are known, to which separate intake ports lead. The intake ports are fluidly connected via an opening in the region of a spiral-shaped valve chamber.

The known arrangements have the disadvantage of requiring a large flange surface area or a large number of inlet and outlet flanges. This increases the structural space requirements and manufacturing costs.

The DE 102 37 664 A1 discloses a cylinder head with two inlet openings for coolant flowing in from the cylinder block. A main cooling flow is directed between the two exhaust valves toward the spark plug dome, while a secondary cooling flow is formed in the left and right edge areas of the cylinder head chamber. In addition to these provisions, a cooling flow generated by a cooling channel in the region of a transverse engine plane directs coolant directly to a hot spot in the cylinder head housing, which is formed in the wall area of the combustion chamber at the level of the spark plug dome.

The DE 102 56 178 A1 shows a water jacket for a cylinder head, the water jacket having a constriction formed on a sub-path to allow cooling water, which is guided through a central path between two outlet ports, to flow evenly, thereby largely uniformly cooling the section between the outlet ports where heat buildup occurs. The coolant flows from the cylinder block into the cylinder head via two coolant paths.

The DE 699 10 249 T2 discloses a cylinder head for a liquid-cooled internal combustion engine with a circular water chamber for the cooling liquid used to cool the walls of the combustion chambers, the circle having ascending water channels arranged substantially parallel to and near recesses for the stems of the exhaust valves. A collection chamber is arranged in the upper section of the cylinder head. The cooling liquid is supplied to the water chamber via suitable openings formed in the bottom wall of the cylinder head.

The DE 102 51 360 A1 describes a liquid-cooled cylinder head with a coolant distribution channel, of which a lateral coolant channel is passed between a gas channel of an exhaust valve and a screw pipe of a cylinder head screw and a central coolant channel is passed between the two gas channels of the exhaust valves.

Particularly in cylinder heads with cross-flow cooling, it is known to arrange at least one transverse rib in the area of a transverse plane between the cylinders in order to distribute the coolant between both cylinders and to cause an inflow to the exhaust ports of adjacent cylinders.

However, in certain configurations and operating ranges, specifically increased cooling of thermally highly stressed areas of the cylinder head would be required.

From the WO 2004/ 063 551 A1 An inlet collector of the type mentioned is known. The group of The inlet duct sections originate from a first longitudinal side of the intake manifold housing. The flap shaft is mounted directly in the housing. During assembly, the flap shaft must be inserted into a bearing bore in the housing, and the flaps must then be fastened to the flap shaft with fastening screws. Therefore, the assembly and disassembly process of the flaps is relatively labor-intensive and time-consuming. The production of the deep hole for the shaft bearing is also relatively complex. Furthermore, separate machining openings are required on the longitudinal sides of the intake manifold opposite the flaps to machine the flap sealing surfaces.

It is known to pre-tension traction devices using automatic tensioning devices. However, automatic tensioning devices are relatively complex and cost-intensive and require a lot of installation space.

It is also known to manually tension traction devices such as belts by pivoting a unit, for example an alternator of an internal combustion engine. The position of the unit is manually fixed using a screw connection. The tensioning force must then be checked using a special measuring device. It is also known to use a spring with a predefined spring force as an assembly aid, which generates the required tensioning force of the traction device by pivoting the unit. After the position of the unit has been fixed using the screw connection, the spring is removed again. The disadvantage is that this special assembly tool is not always available for tensioning the traction device. In particular, in the event of an unexpected belt change, the belt tension cannot be adjusted to the intended value, or can only be roughly adjusted.

The object of the invention is to achieve targeted cooling in temperature-critical areas of the cylinder head.

According to the invention, this is achieved by branching off from the third coolant path into a riser channel leading to an upper partial cooling chamber.

In this case, it can be provided that the partial cooling chamber at least partially surrounds a central receiving shaft for a component opening into the combustion chamber. Alternatively or additionally, it is possible for the partial cooling chamber to at least partially surround a central receiving shaft for a component opening into the combustion chamber.

The coolant is routed from the third overflow opening in the cylinder block's coolant jacket via the third coolant path directly from the cylinder block's water jacket into the partial cooling chamber in the area of the web between the intake and exhaust valves and/or in the area of the mounting shaft for the central component. This makes it possible to supply precisely defined coolant flows to the thermally critical areas and ensure sufficient heat dissipation.

In an advantageous embodiment, the riser channel can be arranged approximately parallel to the cylinder axis. The riser channel facilitates the casting of the coolant paths through the casting cores and simultaneously serves as a degassing channel for the coolant. Furthermore, the riser channel can be used to direct a defined amount of coolant into the upper coolant chamber.

The height of the third coolant path is at least 0.5 to 3 times the thickness of the fire blanket. This ensures sufficient heat dissipation from thermally critical areas.

A further improvement in cooling performance can be achieved if the cross-section of the third coolant path decreases in the direction of coolant flow. The cross-section can be largest in the area of the overflow opening from the cylinder block, with the third coolant path preferably having a nozzle-like constriction in the area of the fire ceiling before entering the partial cooling chamber. The constriction can be formed, for example, by a bulge in the wall of the third coolant path, preferably at the channel ceiling of the coolant path. The constriction accelerates the coolant flow and can also be directed specifically to a hot spot.

The riser can be located upstream or downstream of the constriction.

Within the scope of the invention, it can further be provided that the first and/or the second coolant path is fluidly connected to the upper section of the cooling chamber arrangement via at least one cooling region bordering an outlet channel.

In a further development of the invention, two cooling chambers can be arranged in the cylinder head, with the first and/or second coolant paths leading into a first cooling chamber and/or the third coolant path leading into a second cooling chamber. Preferably, the first cooling chamber borders the fire deck and the second cooling chamber is arranged above the first cooling chamber. The first and second coolant paths, on the one hand, and the third coolant path, on the other, allow the coolant flows to be distributed specifically between the first and second cooling chambers.

In an embodiment not claimed, it is provided that in the mouth region of the two first and/or second exhaust pipes, the merging first and second exhaust pipes span an angle ≤ 30°, preferably ≤ 20°, wherein the angle is spanned by the tangents in reference points of the inner wall of the exhaust pipes, which reference points are defined by an amount corresponding to approximately half the diameter of the first and second exhaust pipes upstream of a first intersection point of the two tangents, and that a second intersection point of at least one of the two tangents with the wall of the second exhaust pipe or the collecting pipe is located downstream of the first intersection point of the two tangents by an amount which is greater than the diameter of the second pipe or the collecting pipe.

The defined channel design ensures unobstructed flow of exhaust gas from the first exhaust pipe into the second exhaust pipe or the manifold, largely avoiding flow losses. Tests have shown that these effects only occur when the angle is ≤ 30°, preferably ≤ 20°, and the second intersection point between the tangent and the downstream part of the channel wall is farther from the outlet tongue than the diameter of the pipe downstream of the outlet.

The diameter of the pipe section downstream of the respective mouth area is approximately 20% to 30% larger than the diameter of at least one incoming pipe.

The lengths of the exhaust pipes can be between 250 mm and 450 mm, the lengths of the second exhaust pipes between approximately 30 mm and 600 mm.

It is preferably provided that the lengths of at least two flow paths formed by a first and second exhaust pipe between cylinders and manifold of at least two cylinders with a successive firing order are approximately the same and preferably amount to between approximately 350 mm and 850 mm, particularly preferably 650 mm to 850 mm. It is particularly advantageous if the lengths of the flow paths through a first and second exhaust pipe for all cylinders between cylinder and manifold are approximately the same. In a particularly preferred embodiment, it is provided that the sum of the lengths of the flow paths of each two cylinders with a successive firing order is approximately the same and preferably amounts to between 700 mm and 1700 mm.

In this way, adverse influences on flows due to the ignition sequence can be avoided.

Preferably, the total length of the flow paths of all cylinders between the cylinder and the manifold is the same.

In order to achieve a flow calming after the manifold is opened, it is advantageous if the manifold has a straight section adjoining the opening area of the second exhaust pipes, the length of which is preferably greater than the diameter of the manifold.

In an embodiment not claimed, it is provided that the manifold, preferably adjacent to the straight section, has an exhaust gas aftertreatment device, wherein an inlet funnel can be arranged between the straight section and the exhaust gas aftertreatment device. Flow separation can be avoided in particular if the straight section of the manifold is followed by a diffuser whose length corresponds to at least twice the diameter of the manifold. Between inlet and outlet, the diffuser diameter preferably increases by at least approximately 20%. In an embodiment not claimed, it is provided that at least one flexible pipe section is arranged in at least a second exhaust pipe and/or in the manifold, wherein particularly preferably at least one flexible pipe section is arranged in every second exhaust pipe.

Particularly in constructions with limited ground clearance, it is advantageous if at least a first exhaust pipe and/or at least a second exhaust pipe is curved in a loop-like manner and is guided around an exhaust pipe of another cylinder.

When routing the exhaust pipes, particular attention must be paid to straight screw connections for the attachment of the manifold flanges to the cylinder head so that assembly and disassembly can be carried out as smoothly as possible.

The unstressed exhaust system is advantageously suitable for use in a vehicle with an underfloor catalytic converter.

A minimum number of connecting flanges can be achieved by mirroring the channel geometries of the intake and/or exhaust ports of at least two adjacent cylinders with respect to at least one transverse engine plane between the two cylinders. Furthermore, it can be provided that the channel geometries of the intake ports and/or exhaust ports of at least two adjacent cylinders are mirrored with respect to at least one transverse engine plane between the two cylinders.

By mirroring the port geometries, the ports for adjacent cylinders can be merged into a single flange. Preferably, at least two intake ports, preferably exactly two intake ports of intake valves of two adjacent cylinders, extend from a common intake port flange. Likewise, at least two exhaust ports of exhaust valves of two adjacent cylinders extend from a common exhaust flange. Intake and exhaust flanges can be arranged in the region of the transverse engine plane. A first transverse engine plane can intersect a first or second intake flange and/or an exhaust flange. The second transverse engine plane intersects only a second intake flange.

In a variant not claimed, the intake ports of the two intake valves of each cylinder are separated between the intake flanges and at least one valve chamber. This allows for an optimal arrangement of the intake coils and a minimal number of intake flanges, with the number of intake flanges being z+1, where z is the number of cylinders.

If the cylinder geometry is particularly cramped, the required channel cross-sections can still be achieved if at least two intake channels of each cylinder are fluidly connected to one another in the region of the preferably spiral-shaped valve chamber of an intake valve.

The flow connection of the two inlet channels in the area of a valve chamber has the additional advantage that the sand core can be stiffened during the casting process of the inlet channels.

In an embodiment not claimed, it can be provided that a common exhaust port extends from each of two exhaust valves of a cylinder, wherein the common exhaust ports of each of two adjacent cylinders lead to a common exhaust flange, wherein preferably the number of exhaust flanges is z/2, where z is the number of cylinders.

In an embodiment not claimed, the transverse rib is designed and/or arranged asymmetrically with respect to the transverse plane. This results in the coolant flow being throttled on one side of the transverse plane and unthrottled on the other side. Thus, more coolant is supplied to the thermally highly stressed areas of one cylinder than to the adjacent cylinder.

In this case, it can be provided that - viewed in a section normal to the cylinder axis - the center of gravity of the transverse rib is located outside the transverse plane. Alternatively or additionally, it can also be provided that the transverse rib has a longitudinal center plane with respect to which the transverse plane is symmetrical.

The transverse rib itself can be designed symmetrically with respect to a longitudinal center plane passing through the center of gravity. To reduce flow resistance, it is advantageous for the transverse rib to be shaped like an airfoil.

The transverse plane can be spanned by cylinder head bolts arranged between two cylinders.

To simplify the manufacture and assembly of the intake manifold, the valve shaft is mounted in at least one bearing body that can be firmly connected to the housing, wherein the bearing body can preferably be connected to the housing in a form-fitting manner. Particularly preferably, the bearing body can be connected to the housing in the region of the flange of the intake duct sections.

Deep-hole drilling for the valve shaft can be avoided by inserting the bearing body into a groove, preferably milled into the housing, with the shape of the bearing body adapted to the profile of the groove. A precise form fit can be achieved if the groove has a substantially conical profile.

Advantageously, the groove extends in the longitudinal direction of the flange, crossing the inlet channel sections of the group.

In order to enable rapid and correct positioning, it is advantageous if the correct position of the bearing body in the groove is defined by a centering device forming a positive connection, wherein the centering device is preferably formed by a projection of the bearing body or the housing, which interacts with a correspondingly shaped recess of the housing or the bearing body.

To simplify production, it is advantageous to provide a large number of bearing bodies. It is particularly advantageous if the valve shaft is mounted in a bearing body on both sides of each valve. This allows the valve shaft to be mounted without stress.

The bearing bodies are advantageously formed by plastic inserts. The housing of the intake manifold can be made of light metal, particularly aluminum or an aluminum alloy.

Particularly simple assembly and disassembly of the intake manifold can be achieved if the flaps, bearing bodies, and flap shaft are combined into a pre-assembly group. Since the flaps are located directly in the flange area, the flap sealing surfaces can be machined particularly easily from the flange side.

The unstressed inlet manifold is characterized by particularly simple manufacture and rapid assembly and disassembly processes, whereby deep hole drilling for the shaft bearings and intermediate flanges can be avoided.

To simplify the adjustment of the tension for the traction means, it is advantageous if the tensioning device has at least one pre-tensioning element, preferably formed by a helical spring, which exerts a predefined tensioning force on the unit in the tensioning direction, wherein the pre-tensioning element is supported on a tensioning nut fastened to the screw bolt of the screw connection.

It is preferably provided that the clamping nut is designed as a clamping sleeve.

Special tools for adjusting the tension of the traction device and measuring devices can be largely eliminated if the clamping nut has a stop that interacts with a first flange surface of the flange and defines the maximum preload force of the clamping element.

The pretensioning element presses the unit, such as an alternator, against the tensioning device in the tensioning direction. The tensioning nut is tightened until the stop almost lies on the first flange surface. This exerts the intended tensioning force on the unit via the pretensioning element. The unit can be easily fixed in this tensioned position by the screw connection having a lock nut which engages a second flange surface of the flange facing away from the first flange surface. The lock nut presses the flange against the tensioning nut, thereby fixing the position of the unit with the correct, predefined tension of the tensioning device.

• 1 ein nicht beanspruchtes Abgassystem in einer ersten Ausführungsvariante;
• 2 ein nicht beanspruchtes Abgassystem in einer zweite Ausführungsvariante;
• 3 das Detail III aus 1;
• 4 das Detail IV aus 1;
• 5 die nicht beanspruchte Abgasrohranordnung in einem Schnitt gemäß der Linie V-V in 1;
• 6 die nicht beanspruchte Abgasrohranordnung in einer Ansicht;
• 7 die nicht beanspruchte Abgasrohranordnung in einer Draufsicht;
• 8 ein erstes Einbaubeispiel für die nicht beanspruchte Abgasrohranordnung;
• 9 ein zweites Einbaubeispiel für die nicht beanspruchte Abgasrohranordnung;
• 10 eine Kanalanordnung eines nicht beanspruchten Zylinderkopfes in einer ersten Ausführungsvariante;
• 11 eine Kanalanordnung eines nicht beanspruchten Zylinderkopfes in einer zweiten Ausführungsvariante;
• 12 eine Kühlkanalkernanordnung eines erfindungsgemäßen Zylinderkopfes in einer Schrägansicht;
• 13 die Kühlkanalkernanordnung in einem Schnitt in einer Querebene gemäß der Linie XIII-XIII in 12;
• 14 die Kühlkanalkernanordnung in einer Ansicht von der Seite der Zylinderkopfdichtebene;
• 15 einen erfindungsgemäßen Zylinderkopf in einem Schnitt gemäß der Linie XV-XV in 12 oder 14;
• 16 eine Kühlraumanordnung eines nicht beanspruchten Zylinderkopfes in einem Schnitt gemäß der Linie I-I in 17;
• 17 diese Kühlraumanordnung in einem Schnitt gemäß der Linie VII-VII in 16;
• 18 eine Kühlraumanordnung in einer anderen Ausführungsvariante;
• 19 eine Schrägansicht des nicht beanspruchten Einlasssammlers;
• 20 den nicht beanspruchten Einlasssammler in einer Seitenansicht;
• 21 den nicht beanspruchten Einlasssammler in einem Schnitt gemäß der Linie XXI-XXI in 20; und
• 22 eine nicht beanspruchte Spanneinrichtung für ein Zugmittel.

The invention is explained in more detail below with reference to the figures. They show schematically:

• 1 an unclaimed exhaust system in a first embodiment;
• 2 an unstressed exhaust system in a second embodiment;
• 3 the detail III from 1 ;
• 4 the detail IV from 1 ;
• 5 the unclaimed exhaust pipe arrangement in a section along the line VV in 1 ;
• 6 the unclaimed exhaust pipe arrangement in a view;
• 7 the unclaimed exhaust pipe arrangement in a plan view;
• 8 a first installation example for the exhaust pipe arrangement not claimed;
• 9 a second installation example for the exhaust pipe arrangement not claimed;
• 10 a channel arrangement of a non-stressed cylinder head in a first embodiment variant;
• 11 a channel arrangement of a non-stressed cylinder head in a second embodiment;
• 12 a cooling channel core arrangement of a cylinder head according to the invention in an oblique view;
• 13 the cooling channel core arrangement in a section in a transverse plane according to the line XIII-XIII in 12 ;
• 14 the cooling channel core arrangement in a view from the side of the cylinder head sealing plane;
• 15 a cylinder head according to the invention in a section along the line XV-XV in 12 or 14 ;
• 16 a cooling chamber arrangement of a non-stressed cylinder head in a section along the line II in 17 ;
• 17 This cold storage arrangement in a section along the line VII-VII in 16 ;
• 18 a cold room arrangement in a different design variant;
• 19 an oblique view of the unstressed intake manifold;
• 20 the unused intake manifold in a side view;
• 21 the unclaimed inlet manifold in a section along the line XXI-XXI in 20 ; and
• 22 an unstressed tensioning device for a traction device.

Parts with the same function are provided with the same reference symbols in the different versions.

One in the 1 to 9 The exhaust system 10 shown for an internal combustion engine 20 in a non-claimed embodiment has an exhaust pipe arrangement with at least one first exhaust pipe 11, 12, 13, 14 per cylinder 1, 2, 3, 4. The ignition sequence of the cylinders is, for example, 1-3-4-2. Two cylinders 1, 4 or 2, 3, which do not follow one another directly in the ignition sequence, each open into a second exhaust pipe 15, 16. The second exhaust pipes 15, 16 subsequently combine in a common manifold 17. A catalytic converter 18 is arranged downstream of the manifold 17.

In the respective opening region 21, 22 and 23, the incoming first and second exhaust pipes 11, 14; 12, 13; 15, 16 each have an angle α ₁ , α ₂ of a maximum of 30° to one another, wherein the angle α ₁ , α ₂ is defined by the tangents t ₁ , t ₂ and t ₃ , t ₄ in reference points P ₁ , P ₂ and P ₃ , P ₄ of the respective inner wall 11a, 12a, 13a, 14a and 15a, 16a of the respective exhaust pipe 11, 12, 13, 14 and 15, 16. The reference points P ₁ , P ₂ and P ₃ , P ₄ are spaced from a first intersection point S ₁ or S ₃ by a distance - measured in the direction of the flow axis x ₁ or x ₂ of the downstream common second exhaust pipe 15, 16 or collecting pipe 17. The distance a ₁ or a ₂ is half the diameter d ₁ or d ₂ of the first or second exhaust pipes 11, 14; 12, 13 or 15, 16 opening into the mouth region 21, 22 or 23, as in 3 or 4 is shown.

At least one second intersection point S ₂ or S ₄ of a tangent t ₂ or t ₃ with the inner wall 15a of the common second exhaust pipe 15 or the inner wall 17a of the collecting pipe 17 lies downstream of the intersection point S ₁ or S ₃ by an amount b ₁ or b ₂ which is greater than the diameter d ₂ or d ₃ of the common second exhaust pipe 15 or 17. The diameter d ₂ or d ₃ of the common second exhaust pipe or of the collecting pipe 17 is 20% to 30% greater than the diameter d ₁ or d ₂ of the incoming first or second exhaust pipes 11, 14, 12, 13 or 15, 16.

The length of the first exhaust pipes 11, 12, 13, 14 is designated by L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , and the length of the second exhaust pipes 15, 16 is designated by L ₁₅ and L ₁₆ . In order to obtain an equal running length of the exhaust shafts of each cylinder 1, 2, 3, 4, the total length L ₁₁ + L ₁₅ , L ₁₃ + L ₁₆ , L ₁₄ + L ₁₆ , L ₁₂ + L ₁₆ of the flow paths of the first and second exhaust pipes 11, 15; 13, 16; 14, 15; 12, 16 of at least two consecutive cylinders 1, 3, 4, 2 is the same.

In order to obtain equal total lengths for the pipe sections of the cylinders 1, 2, 3, 4, it can be provided that at least one first exhaust pipe 12, 13 and/or one second exhaust pipe 16 is curved in an arc-like manner, wherein advantageously the first or second exhaust pipe 12, 13, 16 can be guided around another first or second exhaust pipe 11, 15, as in 5 is indicated. A loop-like upward guide is particularly advantageous when there is limited ground clearance due to vehicle conditions.

Particularly in the case of curved exhaust pipes 11, 12, 13, and 14, unobstructed, straight access for a tool with the diameter of the tool and the corresponding clearance for assembly and disassembly must be ensured. Therefore, a cylindrical clearance must be provided in front of each fastening screw.

Downstream of the junction of the second exhaust pipes 15, 16, a straight pipe section 17' of the collecting pipe 17 with the length L _G connects to the mouth region 23, wherein the length L _G is greater than the diameter d ₃ of the common collecting pipe 17. It can be, for example, 20 mm.

A diffuser 19 can be connected to the straight pipe section 17', the length L _D of which is at least twice the diameter d ₃ of the manifold 17. The diameter D _d of the diffuser outlet is approximately 20% larger than the diameter d ₃ of the diffuser inlet. In addition to or instead of the diffuser 19, an inlet funnel 24 can be arranged between the manifold 17 and the catalytic converter 18. The flow distance of the catalytic converter 18 to the cylinder head flange of the internal combustion engine 20 is, for example, 300 mm to 500 mm.

2 shows a non-claimed embodiment variant, wherein a flexible pipe section 25, 26 is arranged in the second exhaust pipes 15, 16. Compared to a flexible pipe section in the manifold 17, this arrangement has the advantage that the catalyst 18 can be brought closer to the outlet region 23.

As in 8 and 9 As shown, the exhaust system 10 can be equipped with a so-called sub For example, a catalyst 18 designed as a floor catalyst can be installed in a vehicle 30. The first exhaust pipes 11, 12, 13, 14 are connected to the front or rear of the direct-injection internal combustion engine and open into the second exhaust pipes 15, 16. The sum of the lengths L ₁₁ and L ₁₅ can be, for example, between 650 mm and 850 mm. This is followed by a short straight section, the manifold 17, and then the catalyst 18. A flexible pipe section 25, 26 is arranged in each of the second exhaust pipes 15, 16. The 9 The design shown with the exhaust pipes on the bulkhead side of the vehicle has the advantage that with the short pipe lengths required for gas dynamics, an underfloor catalytic converter can be implemented without the need for additional pipe lengths running under the internal combustion engine.

The subject matter of the present application can be used particularly advantageously in combination with one of the EP 1 362 996 A1 known piston and/or one from the EP 1 363 010 A1 known procedures can be applied.

The one in the 10 and 11 The cylinder head 110 shown in a non-claimed embodiment has a plurality of cylinders 101, 102, 103, 104 arranged next to one another in series, each with two intake valves 105, 106 and two exhaust valves 107, 108 per cylinder 101, 102, 103, 104. An intake port 105a, 106a leads to each intake valve 105, 106, and an exhaust sub-port 107a, 108a leads from each exhaust valve 107, 108, the sub-ports 107a, 108a per cylinder 101, 102, 103, 104 opening into a common exhaust port 109.

The valve pattern and the intake port arrangement 111, as well as the exhaust port arrangement 112 of at least two adjacent cylinders 101, 102, 103, 104 are each mirrored about a transverse engine plane 113a, 113b between two cylinders 101, 102, 103, 104. By mirroring the port geometries, the intake ports 105a, 106a and the exhaust ports 109 of two adjacent cylinders 101, 102, 103, 104 can be combined into a common intake flange 114, 115 or exhaust flange 117 in the region of the transverse engine plane 113a, 113b. The first transverse engine plane 113a intersects a first inlet flange 114 and an exhaust flange 117. The second transverse engine plane 113b intersects only a second inlet flange 115. Exceptions to this are the outer inlet ports 105a of the outermost cylinders 101, 104. Thus, on the exhaust side A, the number of exhaust flanges 117 is equal to half the number of cylinders, namely z/2, where z is the number of cylinders 101, 102, 103, 104. On the intake side E, for an optimal spiral arrangement of the inlet ports 106a, separate routing of the inlet parts of the two inlet ports 105a, 106a leading to the two inlet valves 105, 106 per cylinder 101, 102, 103, 104 is preferred. Due to the symmetrical arrangement, the number of intake flanges 114, 115, 116 is equal to the value z+1, where z is the number of cylinders. Furthermore, during the manufacture of the cylinder head 110, the sand core of the intake ports 105a, 106a can be stiffened by a flow connection 118 between the two intake ports 105a, 106a in the region of the valve chamber 106b, as shown in 10 is shown. 11 shows an arrangement in which the inlet channels 105a, 106a are completely separate.

The described intake and exhaust port arrangement 111, 112 allows the number of connecting flanges 114, 115, 116, 117 to be minimized and the cylinder head 110 to be designed very compactly. The mutual support of the individual intake ports 105a, 106a results in a robust structure. Furthermore, optimal port routing for swirl generation can be achieved.

Of the two intake ports 105a, 106a per cylinder 101, 102, 103, 104, intake port 105a is designed as a tangential port and intake port 6a as a spiral port.

The valve pattern can be rotated - as shown in the exemplary embodiments - or parallel to the longitudinal or transverse planes of the engine.

The cooling chamber arrangement 210 for a cylinder head 230 of an internal combustion engine formed by the cooling channel core arrangement 240 has at least one cooling chamber 210a, which can be fluidly connected to a water jacket (not shown) of a cylinder block via first, second and third coolant paths 201, 202, 203 and their passage openings 204, 205, 206 ( 12 to 15 ). The first and second coolant paths 201, 202 flow around outlet valves (not shown in detail) in an outer cooling region 207, 208. A portion of the coolant, e.g., 15% to 20% of the coolant quantity, can flow via vertical cooling regions 207a, 208a into an upper partial cooling chamber 209. The remainder of the coolant flows through the cylinder head 230 in the transverse direction along the fire deck 222 to a partial cooling chamber between two cylinders and subsequently to the opposite longitudinal side of the cylinder head 230, where the coolant collects along the engine towards a main outlet 231.

The coolant flow of the third coolant path 203 is led directly to a partial cooling chamber 211, which in the embodiment of a on the one hand into a web region 212 between the inlet valve and the exhaust valve and on the other hand into a partially annular region 213 adjacent to the fire deck around a central receiving shaft for a spark plug or an injection device. The third coolant path 203 is arranged essentially in the region of a transverse engine plane 215 of the cylinder head containing the cylinder axis 214. A riser channel 216, which is formed essentially parallel to the cylinder axis 214, branches off from the third coolant path 203 and opens into an upper section 209 of the cooling chamber 210a. The cooling regions 207, 208; 207a, 208a, the upper section 209, and the riser channel 216 thus surround the exhaust channels (not shown in detail), which lead through the free spaces 217, 218 into the 12 and 14 can be seen. The first, second, and third coolant paths 201, 202, 203 are connected to one another via the upper section 209 of the cooling chamber 210.

13 shows a core representation of the cooling chamber arrangement 210 in a section in the engine transverse plane 215.

The height h of the third coolant path 203 is 0.5 to 3 times the thickness s of the fire blanket 222 ( 15 )

In order to direct the coolant specifically to hot spots, at least one bulge 220 can be provided in the region of the channel cover 219 of the third coolant path 203, which forms a nozzle-like constriction 221 of the coolant path, through which the speed of the coolant is increased and redirected to thermally critical spots.

The riser channels 216 serve as degassing channels and as a flow connection to the upper partial cooling chamber 209.

The invention was explained using a cylinder head with cross-flow cooling. However, it is also applicable to cylinder heads with longitudinal flow.

The 16 to 18 show a cooling chamber arrangement 310 in a non-claimed embodiment variant with a cooling chamber 310a of a cylinder head 330 of an internal combustion engine with several cylinders A, B, C, D, which is continuous for several cylinders. Two cylinder head bolts 331, 332 arranged parallel with respect to the cylinder axis 314 span a transverse engine plane 333 centrally between each two cylinders A, B, C, D. In the area of the transverse engine plane 333, a transverse rib 334 is arranged in the water chamber 310a between each two cylinders A, B, C, D, which transverse rib 334 divides the coolant flowing transversely through the water chamber 310a according to the arrows 335 to the inlet channel walls 336, 337 of adjacent cylinders A, B, C, D on both sides of the transverse plane 333. The transverse plane 333 is normal to a longitudinal plane 333a spanned by the cylinder axes 314.

In this embodiment, the transverse rib 334 is arranged asymmetrically and off-center with respect to the transverse plane 333. The center of gravity S of the transverse rib 334 is thus eccentric to the transverse plane 333. The eccentricity is denoted by e.

In the exemplary embodiment, the transverse rib 334 is formed symmetrically with respect to a longitudinal center plane 338 of the transverse rib 334. However, an asymmetric, regular, or irregular shape of the transverse rib 334 is also possible. In particular, the transverse rib 334 can have a streamlined profile, for example, a wing profile.

Due to the off-center and asymmetrical positioning of the transverse rib 334, the clear width a ₁ to the inlet channel wall 336 on one side of the transverse plane 333 is smaller than the clear width a ₂ to the inlet channel wall 337 on the other side of the transverse plane 333. This causes the coolant flow to be throttled on one side and unthrottled on the other. This increases the coolant velocity on one side and slows it down on the other, allowing cooling to be adapted to the respective conditions.

In particular, it is also possible to cause a deflection of the flow by adjusting the transverse rib 334, as in 18 is shown. The longitudinal center plane 338 of the transverse rib 334 is inclined at an angle α > 0 to the transverse plane 333.

In the 19 to 21 1 shows a switchable intake manifold 401 with a housing 402 for an internal combustion engine with multiple cylinders in a non-claimed embodiment. The housing 402, which encloses a common collecting chamber 403 for all cylinders, is essentially constructed in one piece. From the collecting chamber 403, intake duct sections 404 lead to the cylinders (not shown in detail), which are integral with the housing 402. At least one group of intake duct sections 404 is designed to be switchable. The intake duct sections 404 are connected to a cylinder head (not shown in detail) via a flange 405.

In the area of the flange 405, flaps 406 can be arranged in the inlet duct sections 404 of the inlet manifold 401. The flaps 406 of several inlet duct sections 404 are connected via a common flap shaft 407. The flap shaft 407 is essentially wedge-shaped and mounted in bearing bodies 408 on both sides of each flap 406.

In the area of the flange 405, the housing 402 has a groove 409 that crosses the inlet channel sections 404 and is arranged longitudinally to the flange 405, advantageously milled, for receiving the bearing bodies 408. The profile of the groove 409 is essentially conical, with the bearing bodies having a correspondingly reciprocal shape. The groove 409 accommodates all the bearing bodies 408.

In order to fix the axial position of the bearing parts 408, centering devices 410 forming a positive fit are provided between the bearing bodies 408 and the groove 409. In the exemplary embodiment, the centering devices 410 are each formed by a projection 410a of each bearing body 408, which engages in a corresponding recess 410b of the groove 409. The projections 410a can be designed as lugs cast onto the bearing body 408, which have bores in the housing 402 as counterparts. However, radial webs can also be provided on the inner diameter of the bearing bodies 408, which engage in recesses in the valve shaft 407, thereby enabling positioning of the bearing bodies 408.

The flaps 406 can be pre-assembled on the flap shaft 407, possibly even soldered or welded using a suitable device, thus eliminating the need for complex machining of the flap shaft 407 (slots for flap insertion or threaded holes for flap fastening). In this case, it is advantageous if the bearing bodies 408 are assembled from two or more parts in order to secure them to the flap shaft 407 after the flaps 406 have been attached.

In any case, flaps 406, flap shaft 407, and bearing bodies 408 can be combined into a pre-assembly group 411 and inserted together into the housing 402 of the intake manifold 401. The bearing bodies 408 are formed, for example, by plastic inserts. The sealing of the flange 405 and the bearing body 408 with respect to the cylinder head can be achieved in a known manner, for example, using a soft material gasket.

The 22 shows a tensioning device 501 for a traction means 502, for example a belt, which acts on a drive pulley 503 of an assembly 504, for example an alternator. The traction means 502 is driven, for example, by the crankshaft of an internal combustion engine (not shown in detail). The assembly 504 is designed to be pivotable about an axis (not shown in detail), which is spaced from the axis of rotation of the drive pulley 503. The tensioning of the traction means 502 is achieved by pivoting the assembly 504 in the direction indicated by reference numeral 505.

The clamping device 501 has a screw connection 506 with a screw bolt 507, a clamping nut 508, a preload element 509, and a lock nut 510. The screw bolt 507 is supported with its first end 507a on a bracket 511 of the engine and is connected in the region of its second end 507b to a flange 512 of the unit 504, with the screw bolt 507 penetrating a bore 513 in the flange 512. The clamping nut 508 engaging the screw bolt 507 is designed as a clamping sleeve in the exemplary embodiment. The preload element 509, formed by a helical spring with a defined spring characteristic, is arranged between the clamping nut 508 and the flange 512, with the preload element 509 being pressed against the flange 512 by the clamping nut 508. To adjust the tension of the tensioning device 502, the clamping nut 508 is tightened, whereby the pretensioning element 509 is pressed against the flange 512 with increasing force. The clamping nut 508 has a stop 514 which defines the maximum pretensioning force of the pretensioning element 509. The clamping nut 508 is tightened until the stop 514 just rests on the first flange surface 515 of the flange 512. The distance between the stop 514 and the first flange surface 515, which decreases with the rotation of the clamping nut 508 in the pretensioning direction, is designated by x. The unit 504 is thus pressed by the pretensioning element 509 with the maximum permissible force in the tensioning direction 505, whereby the predefined tension of the tensioning device 502 is reached. In this position, the lock nut 510 is tightened in the direction of the clamping nut 508, whereby the lock nut 510 acts on a second flange surface 516 facing away from the first flange surface 515. The flange 512 is thus fixed between the clamping nut 508 and the lock nut 510.

By means of the described tensioning device 501, the intended tension of the traction means 502 can be adjusted without special tools and without a special measuring device, so that, for example, a replacement of the traction means 502 away from a workshop is possible with little effort and while maintaining the prescribed tension of the traction means 502.

Claims (15)

Cylinder head (230) for a liquid-cooled internal combustion engine, with a cooling chamber arrangement (210) with at least one cooling chamber (210a), which can be flow-connected to a coolant jacket of a cylinder block connectable to the cylinder head (230) via at least two coolant paths (201, 202) arranged on a longitudinal side per cylinder, each via a transfer opening (204, 205) in a cylinder head sealing surface, wherein a first and second coolant path (201, 202) are arranged on different sides of an engine transverse plane (215) containing a cylinder axis (214), wherein a third coolant path (203) originating from a third overflow opening (206) is arranged at least partially in the region of the engine transverse plane (215), and wherein the third coolant path (203) leads, separately from the first and second coolant paths (201, 202), to at least one partial cooling chamber (211) in a thermally stressed region of the cylinder head (230), characterized in that from the third coolant path (203) a riser channel (216) leading to an upper section (209) of the cooling chamber arrangement (210) branches off. Cylinder head (230) after Claim 1 , characterized in that the partial cooling chamber (211) is arranged in the region of at least one web (212) between an inlet valve (105, 106) and an outlet valve (107, 108). Cylinder head (230) after Claim 1 or 2 , characterized in that the partial cooling chamber (211) at least partially surrounds a central receiving shaft for a component opening into a combustion chamber. Cylinder head (230) according to one of the Claims 1 until 3 , characterized in that the riser channel (216) is arranged approximately parallel to the cylinder axis (214). Cylinder head (230) according to one of the Claims 1 until 4 , characterized in that the height (h) of the third coolant path (203) corresponds to at least 0.5 to 3 times the thickness (s) of a fire blanket (222) bordering the cylinder head sealing surface. Cylinder head (230) according to one of the Claims 1 until 5 , characterized in that the cross section of the third coolant path (203) decreases in the flow direction of the coolant. Cylinder head (230) after Claim 6 , characterized in that the cross section of the third coolant path (203) is largest in the region of the overflow opening (206) of the cylinder block. Cylinder head (230) according to one of the Claims 1 until 7 , characterized in that the third coolant path (203) has a nozzle-like constriction (221) in the region of the fire blanket (222) before entering the partial cooling chamber (211). Cylinder head (230) after Claim 8 , characterized in that the constriction (221) is formed by a bulge (220) of the wall. Cylinder head (230) after Claim 9 , characterized in that the wall is the channel ceiling (219) of the third coolant path (203). Cylinder head (230) according to one of the Claims 8 until 10 , characterized in that the riser channel (216) starts upstream of the constriction (221) from the third coolant path (203). Cylinder head (230) according to one of the Claims 8 until 10 , characterized in that the riser channel (216) starts downstream of the constriction (221) from the third coolant path (203). Cylinder head (230) according to one of the Claims 1 until 12 , characterized in that the first and/or the second coolant path (201, 202) is fluidly connected to the upper section (209) of the cooling chamber arrangement (210) via at least one cooling region (207, 208) bordering an outlet channel. Cylinder head (230) according to one of the Claims 1 until 13 , characterized in that two cooling chambers are arranged in the cylinder head (230), wherein the first and/or the second coolant path (201, 202) opens into a first cooling chamber and/or the third coolant path (203) opens into a second cooling chamber. Cylinder head (230) after Claim 14 , characterized in that the first cooling chamber is adjacent to the fire deck (222), and that the second cooling chamber is arranged above the first cooling chamber.

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