AT519991A1 - Cylinder head with valve seat ring cooling - Google Patents

Abstract

The invention relates to a cylinder head (1) for an internal combustion engine having at least one cylinder, with at least one valve seat ring (5) for a globe valve, wherein the valve seat ring (5) is associated with an annular cooling channel (6, 6 ') extending at least between at least an inlet opening (70, 70 ') of an inlet channel (7, 7') and at least one outlet opening (80, 80 ') of an outlet channel (8, 8') extends at least partially around the valve seat, wherein inlet (7, 7 ') and outlet channel (8, 8 ') are arranged on the same side of the cylinder. For better cooling of the valve seat and easier production of the inlet channel (7, 7 ') opens in the tangential direction via the inlet opening (70, 70') in the annular cooling channel (6, 6 ') and the outlet channel (8, 8') branches in the tangential direction via the outlet opening (80, 80 ') from the annular cooling channel (6, 6') from.

Description

Summary

The invention relates to a cylinder head (1) for an internal combustion engine with at least one cylinder, with at least one valve seat ring (5) for a lift valve, the valve seat ring (5) being assigned an annular cooling channel (6, 6 '), which is at least between at least an inlet opening (70, 70 ') of an inlet channel (7, 7') and at least one outlet opening (80, 80 ') of an outlet channel (8, 8') extends at least partially around the valve seat, with inlet (7, 7 ') and outlet channel (8, 8 ') are arranged on the same side of the cylinder.

For better cooling of the valve seat and simpler manufacture, the inlet channel (7, 7 ') opens into the annular cooling channel (6, 6') in the tangential direction via the inlet opening (70, 70 ') and the outlet channel (8, 8') branches in the tangential direction via the outlet opening (80, 80 ') from the annular cooling channel (6, 6').

Fig. 3/20

PP31134AT

AVL List GmbH

Cylinder head with valve seat ring cooling

The invention relates to a cylinder head for an internal combustion engine with at least one cylinder, with at least one valve seat ring for a lift valve, the valve seat ring being assigned an annular cooling channel which is at least partially around the valve seat between at least one inlet opening of an inlet channel and at least one outlet opening of an outlet channel extends, the inlet and outlet channels being arranged on the same side of the cylinder.

Today's high-performance internal combustion engines have thermally highly stressed regions, for example in the area of the exhaust valve bridges between the exhaust valve seats. These areas are particularly at risk with regard to thermal deformation and thus increased valve wear.

In order to counteract this problem, the valve seats are surrounded with circumferential cooling channels - a valve seat ring cooling system, a coolant flow being caused around the valve seat between inlets and outlets.

The applicant's AT 513 262 B1 shows a solution in which the inlet and outlet are on the same cylinder side and the valve seat is flowed around in an angular range of at least 280 °. The short-circuit flow between the inlet and outlet is restricted by a throttling point - this prevents on the one hand an uncooled thermal bridge from forming in the area of the short-circuit flow and local overheating and thermal stresses, and on the other hand the majority of the coolant the valve seat over a long distance flows around. A disadvantage of this solution is, in particular, the design of the inlet and outlet channels, which are designed to run in parallel and impinge on the valve seat ring cooling in the radial direction, which results in traffic jams and a disrupted inflow. The implementation of the throttle point during production also means additional effort.

The applicant's AT 513 746 B1 therefore provides that several inlets are provided which are opposite an outlet which runs in the direction of the center of the cylinder, in particular an injector arranged there. The entrances are arranged asymmetrically with respect to a meridian plane of the valve seat ring.

This results in asymmetrical flows in the valve seat ring, which means 1/20

PP31134AT

AVL List GmbH can be used to efficiently cool thermally stressed areas. Disadvantages of this are, in particular, the insufficient short-circuit flow between the inlets and the loss of strength that results from the exit hole in the injector area, particularly in the case of large engines.

It is therefore an object of the invention to avoid the above-mentioned disadvantages of the prior art and to enable more uniform cooling of the valve seat ring and to reduce valve wear.

This object is achieved according to the invention with a cylinder head mentioned at the outset in that the inlet channel preferably opens into the annular cooling channel essentially tangentially via the inlet opening, and that a flow-around path, that is to say the long area of the annular cooling channel of the valve seat between the inlet and outlet openings, flows out extends from the inlet opening over an angular range from 195 ° to 345 ° and the outlet duct branches off from the annular cooling duct via the outlet opening in an angular region between the tangential and radial directions.

In other words, the annular cooling duct of a valve seat ring is both supplied with coolant from the same cylinder side and the coolant is discharged, the inlet duct and the outlet duct flowing around the valve seat ring over an angular range between 195 ° and 345 °. The specified angular range is the absolute value, irrespective of whether the valve seat ring is flowed through in a clockwise or counterclockwise direction.

The inflow of a coolant in a substantially tangential direction ensures a reduced pressure loss and the largest possible cross section in the intersection of the inlet channel-shaped cooling channel. The orientation of the outlet channel according to the invention enables the flow conditions in the annular cooling channel to be set.

In a variant of the invention, the annular cooling channel extends completely around the valve seat ring and in the flow direction the flow path runs between the inlet and outlet openings and a short circuit path between the outlet and the inlet opening. This enables complete flow around and cooling of the valve seat ring.

/ 20th

PP31134AT

AVL List GmbH

Thanks to the invention, an even more efficient cooling of the thermally highly stressed areas of a valve seat ring is possible since the inflow and outflow take place with little pressure loss. For this reason, only a small short-circuit flow is formed in the bypass path on the short connection between the inlet and outlet opening and no additional measures are necessary to suppress this short-circuit flow - these measures often have the disadvantage that local material can cause local overheating cause. The selected orientation of the outlet channel between the tangential and radial directions enables the coolant flow in the bypass path to be matched to the particular use of the cylinder head and sufficient cooling of this area to be achieved.

At the same time, production is greatly simplified because, in contrast to solutions of the prior art, standard processing methods - e.g. Drilling the inlet and outlet channels - can be used without time-consuming processing such as Milling in the head are needed.

The invention thus allows optimal cooling of valve seats with minimal manufacturing effort.

In a variant of the invention, a longitudinal central axis of the inlet channel and / or a longitudinal central axis of the outlet channel run tangentially to an inner channel wall of the annular cooling channel of the valve seat. This enables pressure-optimized inflow and outflow and turbulence can be reduced or completely prevented.

In order to enable a particularly simple manufacture of the cylinder head according to the invention, the inlet and outlet channels run in a common first plane. For example, when drilling, the drill must not be moved and readjusted. At the same time, only a minimal material thickness is influenced by the channels in the direction along the cylinder longitudinal axis.

In a variant of the invention, the inlet channel runs in a first level and the outlet channel in a second level. The first level runs differently than the second level. This allows the cooling flow profile to be given an additional direction.

/ 20th

PP31134AT

AVL List GmbH

The first level advantageously runs parallel to the second level. This also ensures comparatively simple production, since fewer adjustment steps are required, for example, when drilling.

Good use of the available space both in the cylinder head and during production can be achieved if the first level and / or the second level are / is parallel to a cylinder head sealing level.

In a further variant of the invention, at least the outlet duct is connected to a cylinder head cooling jacket. By applying different pressure levels to the intake port and cylinder head cooling jacket, it is easy to achieve favorable flow patterns. Both top-down cooling and from the cylinder block towards the cylinder head are possible.

If at least two globe valves with two associated ones in the cylinder head

Valve openings are provided, particularly good cooling of thermally highly stressed areas is ensured if the inlet channel is arranged on the side of the valve seat facing a valve bridge between the valve openings. The same can be achieved if two exhaust valves with associated exhaust valve openings and two intake valves with associated

Inlet valve openings are provided and at least the inlet channels are arranged in annular cooling channels of the valve seat rings of the outlet valve openings on the side of the valve seat rings facing an outlet valve bridge.

Further details, features and advantages of the invention result from the following explanation of non-restrictive exemplary embodiments schematically illustrated in the drawings. In it show:

Figure 1 is a plan view of a horizontal section through the cylinder head along line I-I in Fig. 7.

FIG. 2 shows a partial side view of the cylinder head from FIG. 1;

Fig. 3 shows a detail of a top view of the combustion chamber

Horizontal section through the cylinder head along line III-III in Fig. 2;

4 shows a detail of a vertical section through the cylinder head along the line IV-IV in FIG. 1;

/ 20th

PP31134AT

AVL List GmbH

5 shows a detail of a vertical section through the cylinder head along the line V-V in FIG. 1;

6 shows a detail of a vertical section through the cylinder head along the line VI-VI in FIG. 1;

7 shows a section of a vertical section through the cylinder head along the line VII-VII in FIG. 1; and

8 shows a schematic representation of a section of a top view on the combustion chamber side of a horizontal section through the cylinder head according to FIG. 3.

For reasons of clarity, similar elements are identified in the following figures with the same reference symbols.

In the exemplary embodiment shown, the figures show sections of a cylinder head 1 for at least one cylinder of an internal combustion engine. According to the illustration in FIG. 1, the cylinder head is provided with two inlet and two outlet valves designed as lift valves - the figures show the outlet valve openings 2a, 2b and the inlet valve openings 3a, 3b for the respective valves, in some cases also with an associated valve axis , Of course, the invention is also applicable to cylinders with fewer valves. A further opening is provided in the center of the cylinder, for example as a central opening 4 for an injection device.

At least for each exhaust valve, a valve seat ring 5 is arranged in the cylinder head 1, for example pressed in or glued in, as shown in FIGS. 4-7 can be seen. The valve seat ring 5, which is pressed or glued into the cylinder head 1, is surrounded by an annular cooling channel 6, 6 'for a coolant, which is at least between an (valve-side) inlet opening 70, 70' of an inlet channel 7, 7 'and an (valve-side) outlet opening 80 , 80 'of an outlet channel 8, 8' extends at least partially around the valve seat. The cooling channel 6, 6 ′ can run completely in the valve seat ring 5 or - as in the exemplary embodiment shown - partly molded into the cylinder head 1, partly in the valve seat ring 5. The cooling channel 6, 6 'can also be completely molded in the cylinder head 1.

/ 20th

PP31134AT

AVL List GmbH

Coolant is supplied from outside the cylinder / cylinder head 1 via the inlet duct 7 '(FIG. 4), flows into the annular cooling duct 6' via the inlet opening 70 '(FIG. 5) and enters the outlet opening 80' (FIG. 6) from the cooling duct 6 'into an outlet duct 8' (FIG. 7), from where it flows on. In the exemplary embodiment shown, the annular cooling duct 6, 6 'extends completely around the valve seat ring 5. There is a flow path 90, 90' where the coolant flows around the annular cooling duct 6, 6 'over a long path, and a short circuit path 91, 91'. , that is the shortest connection between inlet 70, 70 'and outlet opening 80, 80'. Inlet 7, 7 'and outlet channel 8, 8' are formed, for example, by bores emanating from a side surface of the cylinder head 1, as can be seen in FIG. 2. Inlet 7, 7 'and outlet channel 8, 8' are advantageously arranged on the same side of the cylinder - in the present example on the outlet side.

A balanced relationship between flow 90, 90 'and short circuit path 91.91' and thus good flow and cooling can be achieved if the center angle α (FIG. 1) of valve seat ring 5 between inlet 70 and outlet 80 is less than 180 °, advantageously less than 100 °. The center angle α is the angle between the radial connections between the valve seat ring center 50 on the one hand and the inlet 7 and outlet duct 8 on the other hand, in particular the point where a longitudinal central axis of the inlet duct (central longitudinal axis of the inlet 77) or the outlet duct (central longitudinal axis of the outlet 88) on the annular Cooling channel 6, or its outside 61, strikes. The long area of the annular cooling channel around which the coolant flows, between the inlet opening 70, 70 'and the outlet opening 80, 80' and thus the area around the flow path 90, extends over an angular range of 360 ° - α around the valve seat ring 5. According to the invention, the angular range is between 195 ° and 345 °. It has been found that the best possible heat dissipation from thermally critical areas of the cylinder head 1 can take place with this angular range of the flow path 90, 90 ′.

In the exemplary embodiment shown there is therefore one

Short circuit flow between the two openings 70, 70 ″, 80, 80 ″ on the short circuit path 91, 91 ″, on the other hand a cooling flow on the flow path 90, 90 ″ surrounding the valve seat over a long path.

/ 20th

PP31134AT

AVL List GmbH

As can be seen in particular in FIG. 3, the inlet channel 7, 7 'in the exemplary embodiment shown opens tangentially via the inlet opening 70 into the annular cooling channel 6, 6'. In the context of the present disclosure, tangential means that - within manufacturing tolerances - elements of inlet 7, 7 '/ outlet duct 8, 8' and annular cooling duct 6, 6 'touch at one point. This means that, for example, a side of the inlet 7, 7 '/ outlet channel 8, 8' facing away from the valve axis or the valve seat ring center 50, 50 'of the respective valve seat is also the side facing away (outer side 61,

') of the annular cooling duct 6, 6' touches at one point or that a side of the inlet 7, 7 '/ outlet duct 8, 8' facing the valve axis or the valve seat ring center 50, 50 'touches the side also facing (inner side 62, 62 ') touches the annular cooling channel 6, 6' at one point.

In the variant shown, the central longitudinal axis 77, 77 'of the valve seat extends tangentially to an inner channel wall (inside 62, 62' ') of the annular cooling channel 6, 6' and touches it at one point. The outlet duct 8, 8 'branches off from the annular cooling duct 6 via the outlet opening 80, the outlet longitudinal central axis 88 likewise extending tangentially to the inner duct wall 62 of the annular cooling duct 6 in the exemplary embodiment shown. The shape of the inlet 70, 70 'and outlet openings 80, 80' is thus approximately elliptical.

The tangential inflow and outflow allows a low-turbulence, good cooling flow around the flow path 90, 90 ', at the same time a low pressure loss is achieved and thus the short-circuit flow on the short-circuit path 91.91' is kept low. Cooling of the short-circuit flow area between inlet 70, 70 'and outlet opening 80, 80' is thus ensured, but sufficient coolant remains for cooling the thermally highly stressed areas of the valve seat ring 5 on the flow path 90, 90 'between inlet 70, 70 'and outlet opening 80, 80'.

According to the invention, the outlet channel 8, 8 'can branch off from the annular cooling channel 6 in an angular range between the tangential and radial directions. Tangential direction here means that the direction of flow in the outlet channel 8, 8 ′ corresponds to the direction of flow in the cooling channel 6, so the angle is 0 °.

/ 20th

PP31134AT

AVL List GmbH

Radial direction here means that the angle between the flow direction in the cooling duct 6 and in the outlet duct 8 is 8'90 °.

By varying the angle between the outlet channel and flow direction in the cooling channel 6 in the region of the outlet opening 80, 80 ', the pressure conditions and in particular also the amount of coolant between the flow 90, 90' and the short circuit path 91, 91 'can be set and the cooling effect for the respective one Optimize use case.

In the exemplary embodiment shown, a favorable cooling effect also results in particular from the fact that the inlet channel 7, 7 ′ is arranged or opens on the side of the valve seat ring 5 facing a valve bridge 100 between the outlet valves. Since a high thermal load occurs especially in the area of the outlet-side valve bridge 100, the freshly supplied coolant, which has a comparatively low temperature, can have a particularly good effect here. Even in the case of variants with fewer valves, it is advantageous if the inlet channels 7, 7 'run on the valve bridges 100 side.

FIG. 8 shows a representation of where an inlet channel 7 'opens into an annular cooling channel 6 and an outlet channel 8' exits again. An angle scale is shown, which shows 7 '0 ° at the entrance of the inlet channel, the exit of the outlet channel 8' takes place between 225 ° and 270 °; this results in a flow in the range of 195 ° to 345 ° according to the invention. The direction of the outlet channel 8 'lies between tangential and radial - the exit angle β is therefore between 0 ° (tangential course) and 90 ° (radial course). The outlet channel 8 'shown in solid lines has a very flat course, while an outlet channel 8' shown in dashed lines runs at an angle β close to 90 °. A valve connecting line 200 is shown between the valve seat ring centers 50 of the outlet valve openings 2a, 2b.

In e.g. In the exemplary embodiment shown in FIG. 3, inlet channels 7, 7 'and outlet channels 8, 8' run in a common first plane, the first plane lying in the leaf plane. This ensures simple manufacture, for example when drilling by quickly positioning the drill or when casting by simply inserting the drill cores. In a variant of the invention, the inlet channel 7, 7 'per valve seat runs in the first level and the outlet channel 8, 8' in / 20

PP31134AT

AVL List GmbH a second level - FIG. 4 shows this variant with a dashed outlet channel 8 ', which is slightly offset in the direction of a cylinder head sealing plane 110. The first level runs normal to the leaf level and coincides with the

Entry longitudinal central axis 77 'together, the second plane also runs normal to the sheet plane and coincides with the exit longitudinal central axis 88'. Here the first level is parallel to the second level, both are parallel to the

Cylinder head sealing plane 110 or to a valve seat ring plane 500 (see e.g. FIG. 6), which is defined by the valve seat ring 5 and, in the exemplary embodiment shown, runs parallel to the cylinder head sealing plane 110. As can be seen, the first and second levels in the exemplary embodiment shown likewise run normal to the valve axis 55 (see FIGS. 5-7). In a further variant, which is shown in FIG. 7, the first level runs obliquely to the second level - this embodiment is recognizable by the inlet channel 7 'shown in dashed lines. Both levels are normal to the leaf level again, the first level with the

Entry longitudinal central axis 77 'coincides and is represented by this, the second plane coincides with exit longitudinal center axis 88' and is represented by this.

As shown in Figs. 1 and 3, but in particular FIG. 7, the outlet duct 8, 8 'is connected to a cylinder head cooling jacket 120 which is pulled down in the direction of the cylinder head sealing plane 110. If there are two cylinder head cooling jackets, this can be, for example, the upper cylinder head cooling jacket (that is, further away from the cylinder head sealing plane 110). The area of the outlet channel 8, 8 'leading away from the valve seat ring 5 is closed after the connection to the cylinder head cooling jacket 120 on the outside of the cylinder head 1 with a plug 130, 130'.

Of course, variants are also possible where the outlet channel 8, 8 ′ is guided to the outside of the cylinder head 1 without connection to an upper cylinder head cooling jacket 120. For example, valve seat cooling can also be carried out with a separate cooling circuit.

The invention thus enables optimal, low-turbulence cooling of the valve seat, which is easy to manufacture and does not require any complex processing steps. Through the angular range of the flow path / 20 according to the invention

PP31134AT

AVL List GmbH

90, 90 'and the angular course of the outlet channel, optimal cooling of the valve seat 5, 5' and complete flow can also be achieved through the short-circuit path.

/ 20th

PP31134AT

AVL List GmbH

Claims (9)

Expectations 1. Cylinder head (1) for an internal combustion engine with at least one cylinder, with at least one valve seat ring (5) for a lift valve, the valve seat ring (5) being assigned an annular cooling channel (6, 6 ') which is at least between at least one inlet opening (70, 70 ') of an inlet channel (7, 7') and at least one outlet opening (80, 80 ') of an outlet channel (8, 8') extends at least partially around the valve seat, with inlet (7, 7 ') and outlet channels (8, 8 ') are arranged on the same side of the cylinder, characterized in that the inlet channel (7, 7') preferably opens substantially tangentially via the inlet opening (70, 70 ') into the annular cooling channel (6, 6') that a flow-around path (90, 90 '), that is to say the long area around which the annular cooling channel (6, 6') of the valve seat flows, between the inlet opening (70, 70 ') and outlet opening (80, 80') starting from the inlet opening ( 70, 70 ') extends over an angular range from 195 ° to 345 ° and the outlet channel (8, 8') via the outlet opening (80, 80 ') in an angular range between the tangential and radial directions from the annular cooling channel (6, 6' ) branches off. 2. Cylinder head (1) according to claim 1, characterized in that the annular cooling channel (6, 6 ') extends completely around the valve seat ring (5) and in the direction of flow the flow path (90, 90') between the inlet (70, 70 ') and outlet opening (80, 80') and a short circuit path (91.91 ') between the outlet (80, 80') and the inlet opening (70, 70 '). 3. Cylinder head (1) according to claim 1 or 2, characterized in that a longitudinal central axis (77, 77 ') of the inlet duct (7, 7') and / or a longitudinal central axis (88, 88 ') of the outlet duct (8, 8' ) run / runs tangential to an inner channel wall (62, 62 ') of the annular cooling channel (6, 6') of the valve seat. 4. Cylinder head (1) according to one of claims 1 to 3, characterized in that the inlet (7, 7 ') and the outlet channel (8, 8') run in a common first plane. 5. Cylinder head () according to one of claims 1 to 3, characterized in that the inlet duct (7, 7 ') runs in a first plane and the outlet duct (8, 12/20 PP31134AT AVL List GmbH 8 ″) runs in a second plane, the first plane preferably being parallel to the second plane. 6. Cylinder head () according to one of claims 4 or 5, characterized in that the first plane and / or the second plane are / is parallel to a valve seat ring plane (500). 7. Cylinder head (1) according to one of claims 1 to 6, characterized in that at least the outlet channel (8, 8 '') is connected to a cylinder head cooling jacket (120). 8. Cylinder head (1) according to one of claims 1 to 7, characterized in that at least two valve openings (2a, 2b, 3a, 3b) are provided and the inlet channel (7, 7 ') on that of a valve bridge (100) between the Valve openings (2a, 2b, 3a, 3b) facing side of the valve seat is arranged. 9. Cylinder head (1) according to one of claims 1 to 8, characterized in that two exhaust valve openings (2a, 2b) and / or two intake valve openings (3a, 3b) are provided, with at least the intake ports (7, 7 ') in annular Cooling channels (6, 6 ') of the valve seat rings (5) of the outlet valve openings (3a, 3b) are arranged on the side of the valve seat rings (5) facing an outlet valve bridge (110). 13/20 PP31134AT AVL List GmbH 1.4 Fig. 2 IV 14/20 PP31134AT AVL List GmbH 15/20 PP31134AT AVL List GmbH 16/20 PP31134AT AVL List GmbH 4.4 Fig. 8 17/20