WO2018218268A1

WO2018218268A1 - Cylinder head comprising valve seat insert cooling

Info

Publication number: WO2018218268A1
Application number: PCT/AT2018/060112
Authority: WO
Inventors: Andreas Zurk; Robert Pöschl
Original assignee: Avl List Gmbh
Priority date: 2017-06-02
Filing date: 2018-05-30
Publication date: 2018-12-06
Also published as: AT519991B1; CN110709596B; CN110709596A; JP2020521914A; DE102017219646A1; AT519991A1

Abstract

The invention relates to a cylinder head (1) for an internal combustion engine comprising at least one cylinder, having at least one valve seat insert (5) for a poppet valve, wherein an annular cooling channel (6, 6') is associated with the valve seat insert (5) and extends at least partially around the valve seat 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'), wherein the inlet channel (7, 7') and the outlet channel (8, 8') are arranged on the same side of the cylinder. In order to improve the cooling of the valve seat and provide a simpler manufacturing process, the inlet channel (7, 7') opens in a tangential direction via the inlet opening (70, 70') into the annular cooling channel (6, 6'), and the outlet channel (8, 8') branches in the tangential direction from the annular cooling channel (6, 6') via the outlet opening (80, 80').

Description

Cylinder head with valve seat ring cooling

The invention relates to a cylinder head for an internal combustion engine having at least one cylinder, with at least one valve seat ring for a globe valve, wherein the valve seat ring is associated with an annular cooling channel, at least between at least one inlet opening of an inlet channel and at least one

Outlet opening of an outlet channel extends at least partially around the valve seat, wherein the inlet and outlet channel are arranged on the same side of the cylinder.

Today's high-performance internal combustion engines have thermally highly stressed regions, for example in the field of exhaust valve bridges between the

Exhaust valve seats on. These areas are particularly at risk for thermal deformation and thus increased valve wear.

To counteract this problem, the valve seats with circumferential cooling channels - a valve seat ring cooling - surrounded, between the inlet and outlet coolant flow is caused to the valve seat.

Applicant's AT 513 262 B1 shows a solution in which inlet and outlet are made on the same cylinder side and the valve seat flows around in an angle range of at least 280 °. The short-circuit flow resulting between inlet and outlet is restricted by a restrictor - this prevents the formation of an uncooled thermal bridge in the area of the short-circuit flow, local overheating and thermal stresses and, on the other hand, the majority of the coolant over the long term flows around. Disadvantage of this solution is in particular the execution of the inlet and outlet channels, which are designed to run parallel and impinge in the radial direction on the valve seat ring cooling, resulting in traffic jams and a faulty inflow. The design of the throttle during production also means additional effort.

Applicant's AT 513 746 B1 therefore provides for multiple entries

are provided, which faces a running in the direction of the cylinder center, especially a arranged there injector outlet. The entrances are arranged asymmetrically with respect to a meridian plane of the valve seat ring.

This results in asymmetric flows in the valve seat ring, which thermally highly stressed areas can be cooled particularly efficiently. Disadvantages of this are in particular the insufficient short circuit flow between the entrances and the loss of strength, which is due to the

Outlet bore in the injector, especially for large engines results.

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

This object is achieved with a cylinder head mentioned above according to the invention that the inlet channel preferably opens substantially tangentially through the inlet opening into the annular cooling channel, that a

Umströmungsweg, so the long-flow area of the annular cooling channel of the valve seat between the inlet and outlet opening extending from the inlet opening over an angular range of 195 ° to 345 ° and the

Outlet channel in over the outlet opening in an angular range between

tangential and radial direction branches off from the annular cooling channel.

In other words, the annular cooling passage of a valve seat ring is charged by the same cylinder side with coolant as well as the coolant is discharged, wherein the inlet channel and the outlet channel flow around the valve seat ring over an angular range between 195 ° and 345 °. The specified angle range is the absolute value, regardless of whether the valve seat ring is flowed through in a clockwise or counterclockwise direction.

By the inflow of a coolant in a substantially tangential direction is a reduced pressure drop and the largest possible cross-section in the

Intersection inlet channel-annular cooling channel ensured. The inventive orientation of the outlet channel is a setting of

Flow conditions in the annular cooling channel allows.

In a variant of the invention, the annular cooling channel extends completely around the valve seat ring and in the flow direction the Umströmungsweg between the inlet and outlet openings and a short-circuit path between the outlet and the inlet opening extends. This allows complete flow and cooling of the valve seat ring. Thanks to the invention, an even more efficient cooling of the thermally highly stressed areas of a valve seat ring is possible because the inflow and outflow takes place with a low pressure loss. For this reason, only a small forms

Short-circuit flow in the bypass path on the short connection between the inlet and outlet and no additional measures to suppress this short-circuit flow are necessary - these measures are often the

Disadvantage of causing additional local overheating due to additional material. Due to the selected orientation of the outlet channel between the tangential and radial directions, the coolant flow in the bypass path can be matched to the particular use of the cylinder head and sufficient cooling of this area can be achieved.

At the same time, manufacturing is greatly simplified since, unlike prior art solutions, standard processing methods - e.g. Drilling the inlet and outlet channels - are used without elaborate processing such. Milling in the head are needed.

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

In a variant of the invention run / runs a longitudinal center axis of the

Inlet channel and / or a longitudinal central axis of the outlet channel tangent to an inner channel wall of the annular cooling channel of the valve seat. Thus, a pressure-optimized inflow and outflow is possible and turbulence can be reduced or completely prevented.

In order to allow a particularly simple production of the cylinder head according to the invention, the inlet and the outlet channel extend in a common first plane. This must be e.g. when drilling the drill are not laboriously 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 extends in a first plane and the outlet channel in a second plane. The first level is different than the second level. As a result, the cooling flow curve an additional

Be given direction. Conveniently, the first plane runs parallel to the second plane. As a result, a comparatively simple production can also be ensured since, for example, fewer adjustment steps are necessary during drilling.

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

In a further variant of the invention, at least the outlet channel is connected to a cylinder head cooling jacket. By applying different pressure levels on the inlet channel and cylinder head cooling jacket can thus achieve favorable flow characteristics in a simple manner. Both a cooling top-down and from the cylinder block in the direction of the cylinder head is possible.

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

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

Exhaust valve openings and two intake valves with associated

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

Further details, features and advantages of the invention will become apparent from the following description of schematically illustrated in the drawings, non-limiting embodiments. Show:

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

Fig. 2 is a fragmentary side view of the cylinder head of Fig. 1;

Fig. 3 shows a detail of a combustion chamber side view of a

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

6 shows a section of a vertical section through the cylinder head along the line Vl-Vl in Fig. 1.

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

8 is a schematic representation of a section of a combustion chamber side plan view of a horizontal section through the cylinder head of FIG. 3rd

In the following figures, like elements are marked with the same reference numerals for reasons of clarity.

The figures show in the illustrated embodiment fragmentary a cylinder head 1 for at least one cylinder of an internal combustion engine. As shown in Fig. 1, the cylinder head is provided with two designed as a lift valves inlet and two exhaust valves - in the figures are the

Exhaust valve openings 2a, 2b and the inlet valve openings 3a, 3b shown for the respective valves, partly with an associated valve axis.

Of course, the invention is also applicable to cylinders with fewer valves. In the center of the cylinder, a further opening, for example as a central opening 4 for an injection device is provided.

At least for each outlet valve, a valve seat ring 5 is arranged in the cylinder head 1, for example, pressed or glued, as shown in FIGS. 4-7 is apparent. The pressed into the cylinder head 1 or glued valve seat ring 5 is surrounded by an annular cooling channel 6, 6 'for a coolant which at least between a (valve side) inlet opening 70, 70' of an inlet channel 7, 7 'and a (valve side) outlet opening 80th '80' of an outlet channel 8, 8 'extends at least partially around the valve seat. The cooling channel 6, 6 'can thereby run completely in the valve seat ring 5 or - as in the illustrated embodiment - partly formed in the cylinder head 1, partly executed in the valve seat ring 5. The cooling channel 6, 6 'can also be completely formed in the cylinder head 1. Coolant is supplied from outside the cylinder / cylinder head 1 via the inlet channel 7 '(FIG. 4), flows via the inlet opening 70' (FIG. 5) into the annular cooling channel 6 'and exits at the outlet opening 80' (FIG. 6). from the cooling channel 6 'into an outlet channel 8' (FIG. 7), from where it continues to flow. In the illustrated

Embodiment, the annular cooling channel 6, 6 'extends completely around the valve seat ring 5. There is a Umstromungsweg 90, 90', where the coolant flows around the annular cooling channel 6, 6 'in a long way, and a Kurzschlussweg 91, 91', ie the shortest connection between inlet 70, 70 'and outlet 80, 80'. Entry 7, 7 'and outlet channel 8, 8' are formed, for example, by outgoing from a side surface of the cylinder head 1 holes, as shown in Fig. 2 can be seen. Conveniently, inlet 7, 7 'and outlet channel 8, 8' are arranged on the same side of the cylinder - on the outlet side in the present example.

A balanced ratio between Umströmungs- 90, 90 'and Kurzschlussweg 91, 91' and thus good flow around and cooling can be achieved when the center angle α (Fig. 1) of the valve seat ring 5 between inlet 70 and

Outlet opening 80 is smaller than 180 °, conveniently smaller than 100 °. Of the

Center angle α is the angle between the radial connections between the valve seat ring center 50 on the one hand and the inputs 7 and

Outlet channel 8 on the other hand, in particular the point where a longitudinal central axis of the inlet channel (entrance longitudinal central axis 77) and the outlet channel

(Exit longitudinal center axis 88) on the annular cooling channel 6, and the

Outside 61, impinges. The flowed around by coolant long area of the

annular cooling channel between inlet 70, 70 'and outlet opening 80, 80' and thus the region of the Umstromungswegs 90 extends over an angular range of 360 ° - α to the Ventilsitznng 5. According to the invention, the angular range between 195 ° and 345 °. It has been found that with this angular range of the Umstromungswegs 90, 90 ', a best possible heat dissipation from thermally critical areas of the cylinder head 1 can be done.

In the illustrated embodiment, therefore, there is a one hand

Short circuit flow between the two openings 70, 70 ', 80, 80' on the Kurzschlussweg 91, 91 ', on the other hand, the valve seat on a long road

surrounding cooling flow on the Umstromungsweg 90, 90 '. As can be seen in particular from FIG. 3, the inlet channel 7, 7 'in the embodiment shown opens tangentially via the inlet opening 70 into the annular cooling channel 6, 6'. Tangential in the context of the present disclosure means that - within manufacturing tolerances - elements of

Inlet 7, 77 'exit channel 8, 8' and annular cooling channel 6, 6 'touch in one point. This means that, for example, one of the valve axis or the

Valve seat ring center point 50, 50 'of the respective valve seat side facing away from the inlet 7, 77Augittskanals 8, 8' the likewise opposite side (outside 61, 61 ') of the annular cooling channel 6, 6' touched in one point or that one of the valve axis or the Valve seat ring center 50, 50 'facing side of

Inlet 7, 77 'exit channel 8, 8' the likewise facing side (inside 62, 62 ') of the annular cooling channel 6, 6' touched in one point.

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

The tangential inflow and outflow allows a low-turbulence, good cooling flow around the Umströmungsweg 90, 90 ', at the same time a low pressure drop is achieved and thus the short-circuit flow on the Kurzschlussweg 91, 91' kept low. Although a cooling of the short-circuit flow area between inlet 70, 70 'and outlet opening 80, 80' is thus ensured, but there is sufficient coolant for cooling the thermally highly stressed areas of the valve seat ring 5 on the Umströmungsweg 90, 90 'between inlet 70, 70th '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 tangential and radial direction. Tangential direction here means that the flow direction in the outlet channel 8, 8 'corresponds to the flow direction in the cooling channel 6, ie the angle is 0 °. Radial direction means here that the angle between the flow direction in the cooling channel 6 and in the outlet channel 8, 8 ^X 90 °.

By varying the angle between the outlet channel and the flow direction in the cooling channel 6 in the region of the outlet opening 80, 80 ', the pressure conditions and in particular the coolant quantity between Umstromungs- 90, 90' and Kurzschlussweg 91, 91 'set and the cooling effect for the respective

Optimize use case.

A favorable cooling effect results in the illustrated embodiment, in particular also by the fact that the inlet channel 7, 7 'is arranged or opens on the one valve bridge 100 between the exhaust valves facing side of the valve seat ring 5. Especially in the area of the exhaust side

Valve bridge 100 a high thermal load occurs, the freshly supplied, a comparatively low temperature having coolant can develop a particularly good effect here. Even with variants with fewer valves, it is favorable if the inlet channels 7, 7 'extend on the sides of the valve bridges 100.

8 shows an illustration where an inlet channel 7 'opens into an annular cooling channel 6 and an outlet channel 8' emerges again. In this case, an angle scale is shown, the entry of the inlet channel 7 '0 °, the outlet of the

Outlet channel 8 'takes place between 225 ° and 270 °; This results in a Umstromung in the inventive range of 195 ° to 345 °. The direction of the outlet channel 8 'is between tangential and radial - the exit angle ß is thus between 0 ° (tangential course) and 90 ° (radial course). The discharge channel 8 'shown in solid lines has a very flat course, while an outlet channel 8' shown by dashed lines runs at an angle β near 90 °. Between

Valve seat ring center points 50 of the exhaust valve openings 2a, 2b is one

Valve connection line 200 shown.

In the exemplary embodiment shown in FIG. 3, for example, inlet 7, 7 'and outlet channels 8, 8' extend in a common first plane, wherein the first plane lies in the plane of the page. For a simple production, for example when drilling by rapid positioning of the drill or casting by simply inserting the cores ensured. In a variant of the invention, the inlet channel 7, 7 'extends per valve seat in the first plane and the outlet channel 8, 8' in a second level - Fig. 4 shows this variant with a dashed running outlet channel 8 ', which is slightly offset in the direction of a cylinder head density plane 1 10. The first level runs normal to the leaf level and falls with the

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

Cylinder head sealing plane 1 10 or to a valve seat ring plane 500 (see, for example, Fig. 6), which is defined by the valve seat ring 5 and in the illustrated embodiment, parallel to the cylinder head density plane 1 10 extends. As can be seen, the first and second planes also run normal to the valve axis 55 in the illustrated embodiment (see Figures 5-7). In a further variant, shown in Figure 7, the first plane is oblique to the second plane - this embodiment is recognizable by the dashed line inlet channel 7 '. Both levels are normal again to the leaf level, with the first level with the

The longitudinal axis of entry 77 'coincides and is represented by the second plane coincides with the exit longitudinal central axis 88' and is represented by this.

As in Figs. 1 and 3, but in particular Fig. 7 can be seen, is the

Outlet channel 8, 8 'with a in the direction of the cylinder head density level 1 10th

pulled down cylinder head cooling jacket 120 connected. In the presence of two cylinder head cooling jackets, for example, this may be the upper (ie further from the cylinder head sealing plane 110) cylinder head cooling jacket. The away from the valve seat ring 5 region of

Outlet channel 8, 8 'is closed after connection with 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 without connection to an upper cylinder head cooling jacket 120 to the outside of the cylinder head 1. For example, the valve seat cooling can be done with a separate cooling circuit.

The invention thus enables optimal, low-turbulence cooling of the

Valve seat, which is easy to produce and manages without elaborate processing steps. Due to the inventive angular range of Umströmungswegs 90, 90 'and the angular course of the outlet channel optimal cooling of the valve seat 5, 5' and complete Umstromung can also be achieved by the Kurzschlussweg.

Claims

claims

1 . Cylinder head (1) for an internal combustion engine having at least one cylinder, with at least one valve seat ring (5) for a lift valve, wherein the valve seat ring (5) is associated with an annular cooling channel (6, 6 ') extending 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, inlet (7, 7 ') and outlet channel (8 , 8 ') are arranged on the same side of the cylinder, characterized in that the

Inlet channel (7, 7 ') preferably substantially tangentially over the

Inlet opening (70, 70 ') in the annular cooling channel (6, 6') opens, that a Umströmungsweg (90, 90 '), ie the long-flow area of the annular cooling channel (6, 6') of the valve seat between inlet ( 70, 70 ') and outlet opening (80, 80') extending from the inlet opening (70, 70 ') over an angular range of 195 ° to 345 ° and the outlet channel (8, 8') via the outlet opening (80, 80 ') branches off in an angular range between tangential and radial direction of the annular cooling channel (6, 6').

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 flow direction of the Umströmungsweg (90, 90') between the inlet (70, 70 ') and outlet opening (80, 80') and a Kurzschlussweg (91, 91 ') between the

Exit (80, 80 ') and the inlet opening (70, 70') extends.

3. Cylinder head (1) according to claim 1 or 2, characterized in that a longitudinal center axis (77, 77 ') of the inlet channel (7, 7') and / or a longitudinal central axis (88, 88 ') of the outlet channel (8, 8' ) tangentially to an inner channel wall (62, 62 ') of the annular cooling channel (6, 6') of the valve seat runs / runs.

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') extend in a common first plane.

5. Cylinder head () according to one of claims 1 to 3, characterized in that the inlet channel (7, 7 ') extends in a first plane and the outlet channel (8, 8 ') extends in a second plane, wherein preferably the first plane is 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 parallel to a valve seat ring plane (500) are / is.

7. Cylinder head (1) according to one of claims 1 to 6, characterized in that at least the outlet channel (8, 8 ') with a cylinder head cooling jacket (120) is connected.

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 the one valve bridge (100) between the Valve openings (2a, 2b, 3a, 3b) facing 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 inlet valve openings (3a, 3b) are provided, wherein at least the inlet channels (7, 7 ') in annular

Cooling channels (6, 6 ') of the valve seat rings (5) of the exhaust valve openings (3a, 3b) on the exhaust valve bridge (1 10) facing side of the valve seat rings (5) are arranged.