WO2016120124A1

WO2016120124A1 - Cylinder head of an internal combustion engine

Info

Publication number: WO2016120124A1
Application number: PCT/EP2016/050986
Authority: WO
Inventors: Dieter Grillenberger
Original assignee: Avl List Gmbh
Priority date: 2015-01-27
Filing date: 2016-01-19
Publication date: 2016-08-04
Also published as: AT516150B1; AT516150A4

Abstract

The invention relates to a cylinder head (1) of an internal combustion engine having a plurality of cylinders (2), having at least one cooling jacket (3) and at least one coolant drain channel (5) which extends in the longitudinal direction of the cylinder head (1) substantially over a plurality of cylinders (2) and is flow-connected to the cooling jacket (3) in the region of at least one cylinder (2) via in each case at least one connecting channel (4), wherein the coolant drain channel (5) has at least one outlet opening (6) in the region of at least one outlet-side end (7). In order to make simple adaptation of the through flow cross sections of the cooling chambers of individual cylinders possible, it is provided that at least one separating device (9) is arranged in the coolant drain channel (5), which separating device (9) divides the coolant drain channel (5) in the longitudinal direction in the region of at least one cylinder (2) into at least one first part chamber (10) and at least one second part chamber (11), wherein the first part chamber (10) and the second part chamber (11) can preferably be flowed through in different longitudinal directions.

Description

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Cylinder head of an internal combustion engine

The invention relates to a cylinder head of an internal combustion engine having a plurality of cylinders, with at least one cooling jacket and at least one extending in the longitudinal direction of the cylinder head substantially over a plurality of cylinder coolant extraction channel which is fluidly connected to the cooling jacket in the region of at least one cylinder via at least one connecting channel, wherein the Coolant extraction channel has at least one outlet opening in the region of at least one exit-side end.

JP 61-107 948 U l discloses a cooling structure for the cylinder head of an internal combustion engine, wherein in the area between two gas exchange valves outgoing from a side wall blind hole is arranged, which is divided by an insertion part in a lower and an upper part space. The coolant coming from the cylinder block flows into the lower subspace, is deflected by the insertion part and reaches the upper subspace from which it is fed to the water jacket of the cylinder head.

The JP 50-40 943 Ul shows a cylinder head with a transverse flow-through cooling space, with baffles are provided to prevent direct short-circuit currents between inlet and outlet and to allow better cooling in the fire deck.

In the case of water-cooled cylinder heads for a plurality of cylinders, a uniform throughflow situation is generally desired for each cylinder. In this case, a minimum flow should be formed in order to avoid local vapor bubble formation. In particular, a short-circuit flow should be avoided with the cylinders close to the outlet towards the outlet opening, as this would lead to small quantities of coolant flowing over the combustion chambers of cylinders remote from the outlet. The coordination of the inflow and outflow cross sections of the cooling chambers of the individual cylinders is complicated and is usually carried out by means of many iteration steps, the cross sections between the coolant jacket and the coolant outlet being tuned. Sometimes, however, the cross sections are reduced to a level at which there is a very great risk that the sand core required for the casting process itself breaks during handling or during the casting process of the cylinder head.

The object of the invention is to avoid these disadvantages and to allow easy adjustment of the flow cross sections of the cooling chambers of individual cylinders. - -

According to the invention, this takes place in that at least one separating device is arranged in the coolant extraction channel, which divides the coolant extraction channel in the region of at least one cylinder into at least one first and at least one second partial space. According to a variant of the invention, the first and second subspaces can be flowed through in different longitudinal directions.

As a result, short-circuit currents of cylinders close to the exit or their cooling jackets can be prevented and uniform mass flows can be achieved through the connection channels. This ensures optimal or need-based cooling over all cylinders, regardless of their position relative to the outlet opening of the coolant extraction channel.

The separating device is preferably formed substantially parallel to the longitudinal axis of the coolant discharge channel. It extends over at least one cylinder, preferably over at least two cylinders. For example, the separator may extend over at least half the length of the coolant extraction channel. In order to prevent a short-circuit flow of the cooling liquid between the cooling jackets of the outlet-side cylinder and the outlet opening, it is advantageous if the separating device is arranged at least in the region of the outlet-side end, wherein preferably the separating device emanates from the outlet opening. Starting from the outlet means here means that the separator takes its exit in the exit-side region of the coolant discharge channel and protrudes from this leading away into the coolant extraction channel. At least one connecting channel opens directly into the first subspace, while the outlet opening emanates from the second subspace. In a variant of the invention, connecting channels open exclusively into the first subspace. The separating device causes the coolant coming from the cooling jackets of the outlet-side cylinders to flow into the first subspace through the connecting channels and to flow in the first subspace along the separating device against the main flow direction of the coolant withdrawal channel directed towards the outlet opening. In the area of the end of the separating device facing away from the outlet opening, the coolant flows from the first subspace into the second subspace, reversing the flow direction, and merging with the coolant streams of the remaining cylinders. Finally, the combined coolant stream leaves the coolant extraction channel through the outlet opening.

A particularly simple production results when the separating device can be inserted from the outlet opening into the coolant extraction channel, wherein the separating device is preferably fixed by means of a connection flange adjoining the outlet opening or is formed integrally therewith. - -

Characterized in that the separator is inserted into the cast or drilled coolant extraction channel, a subsequent fine tuning of the coolant flows can be performed.

It is particularly advantageous if the separating device has at least one flow passage between the first and the second subspace. By number, size and shape of the cross-sectional areas of the flow crossings, the coolant flows of the cooling jackets of the individual cylinders can be adjusted.

In a preferred embodiment of the invention it is provided that the separating device is formed by a preferably at least partially planar partition. The dividing wall may be curved or flat or curved in one section or in individual sections and may be flat in another section or in other sections. The partition can for example consist of sheet metal. In order to allow a positionally correct fixing of the partition wall within the coolant extraction channel, it is advantageous if the coolant extraction channel has at least one substantially parallel to the longitudinal axis of the coolant extraction channel formed guide groove, wherein preferably two guide grooves are arranged diametrically with respect to the longitudinal axis. In this case, the dividing wall can, for example, be positioned essentially "upright", that is to say in the direction of the cylinder axes.

As an alternative to a dividing wall, provision may also be made for the dividing device to be formed by a tube. The tube is arranged within the coolant extraction channel, wherein a first subspace is designed as an annulus and the second annulus forms the tube interior. In a variant of the invention, the tube is arranged concentrically within the coolant extraction channel.

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

1 shows a known cylinder head in a plan view.

Fig. 2, the water chambers of the cylinder head in a section according to the

Line II - II in Fig. 1;

Fig. 3 and Fig. 4 each a cylinder head according to the invention in one

Top view in a different embodiment variants;

Fig. 5 to Fig. 8 coolant extraction ducts in various embodiments, each in a section along the line V - V in Fig. 3; - -

Fig. 9 and Fig. 10 is a detail of a respective coolant extraction channel velvet

Separating device in a longitudinal section in various embodiments;

11 shows a cylinder head according to the invention in a plan view in a further embodiment variant;

FIGS. 12 to FIG. 14 a coolant extraction channel including separating devices in plan views in various embodiments; and

FIG. 15 and FIG. 16 a detail each of a coolant extraction channel velvet

Separating device in a longitudinal section in different embodiments.

Functionally identical elements are provided in the embodiments shown in the figures with the same reference numerals.

Fig. 1 and Fig. 2 schematically show a cylinder head 1 of an internal combustion engine according to the prior art. The shown liquid-cooled cylinder head 1 for four cylinders 2 has at least one cooling jacket 3, wherein the cooling jacket 3 for each cylinder 2 flows through in the transverse direction. The coolant flows according to the arrow PI from the cooling chamber of the cylinder block, not shown, coming into the cooling jacket 3 of the cylinder head 1 and crosses it according to the arrows P2. A part of the coolant then flows according to the arrow P3 in the cooling chamber of the cylinder block. Another part - for example, 10% of the amount of coolant flowing into the cylinder head 1 from the cylinder block - flows according to arrows P4 via at least one connecting channel 4 per cylinder 2 into a coolant withdrawal channel 5 formed in the cylinder head 1, flows through this in a main flow P5 directed towards the outlet opening 6 and leaves the coolant extraction channel 5 according to the arrow P6 through an outlet opening 6 in the region of an outlet-side end 7 of the coolant extraction channel 5.

The length of the illustrated arrows P4 corresponds to the mass flows of the coolant. The longer the arrow, the higher the mass flow. It can be seen clearly that from the outlet next cylinder 2 more coolant enters the coolant extraction channel 5, as from the exit most remote cylinder 2. Thus, there is a short-circuit flow of the coolant at the outlet near cylinders 2 and thus to an uneven flow distribution. An elaborate coordination with many iteration steps so far flow cross sections in the cylinder head and in the coolant extraction channel 5 were fine-tuned, although there was the risk of small sized cross-sections. However, too small cross sections hinder the removal of vapor bubbles and hold the risk that - - The corresponding thin-sized sand core breaks during handling or during the casting process itself.

3 shows a cylinder head 1 according to the invention with a coolant extraction channel 5 extending over a plurality of cylinders 2, which is connected to the cooling jacket 3 in the region of each (in variants of the invention in the region of at least one) cylinder 2 via at least one connection channel 4. The cylinder head 1 differs from the prior art shown in FIGS. 1 and 2 in that a separating device 9 formed by a partition wall 8 is arranged in the coolant extraction duct 5 in the region of cylinders 2a close to the outlet. The separating device 9, in particular a longitudinal axis 9a of the separating device 9, is formed substantially parallel to the longitudinal axis 5a of the coolant extraction channel 5 and divides the coolant extraction channel 5 in the longitudinal direction in at least a first subspace 10 and at least a second subspace 11. In the illustrated embodiment are first and second subspace 10, 11 can be flowed through in different longitudinal directions. This means that, for example, the coolant in the first subspace 10 flows in a direction opposite to the coolant in the second subspace 11. The separating device has a first end 9b and a second end 9c, wherein the first end 9b is arranged in the region of the outlet-side end 7 of the coolant withdrawal channel 5. The first subspace 10 is closed in the region of the exit end 7 end side. The outlet opening 6 is arranged in the region of the outlet-side end 7 on the end face of the second partial space 11. In the exemplary embodiment, the separating device 9 extends over approximately half the length of the coolant extraction channel 5, that is, via two outlet-side cylinders 2a. Short circuit flows between the cooling jacket 3 of the outlet-side cylinder 2 a and the outlet opening 6 of the coolant withdrawal channel are prevented by the separating device 9. The coolant coming from the cooling jackets 3 of the outlet-side cylinders 2 a flows through the connecting channels 4 into the first subspace 10 and along the separating device 9 counter to the main flow direction P 5 of the coolant withdrawal channel 5 directed to the outlet opening 6. In the area of the second end 9 c facing away from the outlet opening 6 Separator 9, the coolant flows under reversal of the flow direction from the first subspace 10 into the second subspace 11, wherein it combines with the coolant streams P4 of the remaining outlet distant cylinder 2b. Finally, the combined coolant flow P6 of the second subspace 11 leaves the coolant removal channel 5 through the outlet opening 6.

A coordination of the distribution of the mass flows of the individual cylinders 2 can take place over the length LI of the separating device 9, or the ratio of the length LI of the separating device to the length L2 of the coolant withdrawal channel 5. If the - -

Separating device 9 does not extend to the exit end 7 of the coolant extraction channel 5 and this front ends can be influenced by said votes the flow behavior.

For a fine-tuning of the mass flows, it is advantageous if the separating device 9 has, as required, a number of flow transitions 12 between the first subspace 10 and the second subspace 11, as shown in FIG. 4 is shown. In this case, the cross-sectional areas and the shape of the flow passages 12 may be different. On the number, size, position and shape of the cross-sectional areas of the flow cross sections 12, the mass flows of the individual cylinders 2, as well as their distribution can be set very precisely.

The partition 8 may be formed for example by a sheet metal or plastic part, which is arranged in the coolant extraction channel 5. In particular, an elastic material, for example spring steel, can be used as the material for the dividing wall 8, which is elastically prestressed and positioned in the coolant extraction duct 5. By way of example, FIG. 5 shows some possible profiles for the partition wall 8 which is elastically supported on the inner walls 5b of the coolant extraction channel 5. In order to enable simple positionally correct positioning and to prevent twisting or twisting of the partition wall 8 in the coolant extraction channel 5, the edges 8a the partition in longitudinal grooves 5c of the coolant extraction channel 5 - during assembly - out or - be stored during operation - as shown in FIGS. 7 and 8 is shown. The longitudinal grooves 5c may extend over the entire length L2 of the coolant extraction channel 5 or only over parts thereof.

The partition wall 8 is inserted from the open exit-side end 7 of the example drilled or cast coolant extraction channel 5 in the axial direction in this. At the coolant extraction channel 5 includes a fastened, for example, with screws 13 on the cylinder head 1 connecting flange 14. In this case, the partition wall 8 in the region of the first end 9b of the separator 9 have an L-shaped bent mounting leg 8b, which is clamped between the flange 14 and the cylinder head 1, whereby the partition 8 is fixed immovably and in the correct position in the axial direction. "L-shaped bent" here means, in particular, that the fastening leg 8b is oriented substantially normal to the longitudinal axis 9a of the separating device 9. Optionally, the mounting leg 8b may be centered in a recess 15 of the cylinder head 1 and / or via a centering pin 16 with respect to the mounting flange 14 to allow for unambiguous positioning (Figure 9). - -

Alternatively, the partition wall 8 may also be integrally formed with the mounting flange 14, as shown in FIG. 10 can be seen.

The Fig. 11 to FIG. 16 show variant embodiments in which the separating device 9 is formed by a tube 18 which is inserted from the open outlet-side end 7 of the coolant extraction channel 5 in this, wherein the tube 18 and coolant extraction channel 5 may be formed concentrically. The tube 18 in this case has a smaller diameter than the coolant extraction channel 5. The cross-sectional shape of the tube 18 can be arbitrary - such as round, oval or polygonal - executed. The existing example of plastic or metal tube 18 separates the first compartment 10 from the second compartment 11, wherein the first compartment 10 is formed as an annular space which surrounds the second compartment 11 concentrically. The first subspace 10 is executed in the illustrated examples, again in the region of the exit end 7 closed frontally. However, it is also possible to provide on the front side openings with a defined cross-section, which open into a connected to the flange 14 outlet line. At least one outlet opening 6 is arranged at the outlet-side end 7 on the end face of the inner second partial space 11. In the illustrated examples, the separating device 9 extends in each case again over two outlet-side cylinder 2a, that is about half the length L2 of the coolant extraction channel 5. The coolant coming from the cooling jackets 3 of the outlet-side cylinder 2a flows through the connection channels 4 into the annular first partial space 10 one and along and outside of the tube 18 opposite to the outlet opening 6 directed main flow direction P5 of the coolant extraction channel 5. In the region of the outlet opening 6 remote from the second end 9c of the separator 9, the coolant flows reversing the flow direction from the outer first compartment 10 into the inner second Subspace 11, wherein it combines with the coolant streams P4 of the remaining outlet distant cylinder 2b. Finally, the combined coolant flow P6 of the second subspace 11 leaves the coolant removal channel 5 through the central outlet opening 6. As an alternative to a central installation position, the tube 18 can also be arranged eccentrically in the coolant withdrawal channel 5. The same applies to the position of the outlet opening. 6

Even in the embodiment as a pipe 18, the separating device 9 may have flow passages 12 between the first subspace 10 and the second subspace 11, which may be formed, for example, by bores in the pipe wall 18a. The flow passages 12 can be distributed over the entire circumference and over the entire length in the tube wall 18a (FIG. 12) or only on one side or in one region - for example on the side facing away from the connecting channels 4 (FIG. 13) or on the the connection channels 4 - - facing side (Fig. 14) may be arranged. The shape and diameter of the flow passages 12 are arbitrary.

In the region of the second end 9c of the separating device 9, the end face 18b of the tube 18 facing away from the outlet opening 6 can be designed to be tapered normal to the longitudinal axis 9a or with respect to this longitudinal axis 9a. By the length of the tube 18, the number, the size of the cross-sectional areas, as well as the shape and the position of the flow cross-over 12, a fine tuning of the coolant flows can be performed.

The tube 18 inserted from the open outlet-side end 7 of the example drilled or cast coolant extraction channel 5 in the axial direction in this. At the coolant extraction channel 5 includes a fastened, for example, with screws 13 on the cylinder head 1 connecting flange 14. In this case, the tube 18 in the region of the first end 9a of the separator 9 have a flange approach 18b, which is clamped between the flange 14 and the cylinder head 1, whereby the partition 8 is fixed immovably and in the correct axial position. By means of at least one centering pin 16, the tube 18 may be centered with respect to the cylinder head 1 or with respect to the mounting flange 14 in order to allow a clear rotational positioning (Fig. 15).

Analogous to FIG. 10, the tube 18 can also be integrated into the connecting flange 14, wherein the centering can be done by the Verschraubungsbild in the connection flange 14 (Fig. 16).

Claims

PATENT APPLICATIONS

1. Cylinder head (1) of an internal combustion engine having a plurality of cylinders (2), with at least one cooling jacket (3) and at least one in the longitudinal direction of the cylinder head (1) substantially over a plurality of cylinders (2) extending coolant extraction channel (5), with the Cooling jacket (3) in the region of at least one cylinder (2) via at least one connecting channel (4) is connected, wherein the coolant extraction channel (5) in the region of at least one outlet end (7) at least one outlet opening (6), characterized in that at least one separating device (9) is arranged in the coolant extraction channel (5) which divides the coolant extraction channel (5) in the longitudinal direction in the region of at least one cylinder (2) into at least one first partial space (10) and at least one second partial space (11).

2. Cylinder head (1) according to claim 1, characterized in that the first partial space (10) and second partial space (11) can be flowed through in different longitudinal directions.

3. Cylinder head (1) according to claim 1 or 2, characterized in that the separating device (9) is formed substantially parallel to the longitudinal axis (5a) of the coolant extraction channel (5).

4. Cylinder head (1) according to one of claims 1 to 3, characterized in that the separating device (9) is arranged at least in the region of the outlet-side end (7), wherein preferably the separating device (9) emanates from the outlet opening (6).

5. Cylinder head (1) according to one of claims 1 to 4, characterized in that at least one connecting channel (4) opens directly into the first part space (10) and the outlet opening (6) from the second part space (11) starts.

6. Cylinder head (1) according to one of claims 1 to 5, characterized in that the separating device (9) is formed by a preferably at least partially planar partition (8).

7. Cylinder head (1) according to claim 6, characterized in that the coolant extraction channel (5) at least one substantially parallel to the longitudinal axis (5a) of the coolant extraction channel (5) formed longitudinal groove (5c), wherein preferably two guide grooves (5c) diametrically with respect the longitudinal axis (5a) are arranged.

8. Cylinder head (1) according to one of claims 1 to 7, characterized in that the separating device (9) is formed by a tube (18).

9. Cylinder head (1) according to one of claims 1 to 8, characterized in that the separating device (9) starting from the outlet opening (6) in the coolant extraction channel (5) can be inserted, wherein preferably the separating device (9) by an exit side fixed to the coolant extraction channel (5) connecting flange (14) or is formed integrally therewith.

10. Cylinder head (1) according to one of claims 1 to 9, characterized in that the separating device (9) has at least one flow passage (12) between the first and the second subspace (10, 11).

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