WO2001020154A1

WO2001020154A1 - Engine, preferably a reciprocating engine

Info

Publication number: WO2001020154A1
Application number: PCT/EP2000/008212
Authority: WO
Inventors: Arne Kvitsgård PETERSEN
Original assignee: Man B & W Diesel A/S
Priority date: 1999-09-10
Filing date: 2000-08-23
Publication date: 2001-03-22
Also published as: DE19943264C2; DE19943264A1; JP2003509622A; KR20020031177A; CN1136382C; KR100506468B1; JP3883866B2; AU6840400A; CN1373832A

Abstract

The invention relates to an engine, such as a two-stroke large diesel engine, comprising two parts (1, 7) that fit together, whereby a cooling channel (12) into which coolant can be introduced, sealing devices which close said cooling channel and which are offset in an axial direction, and supporting surfaces (9, 10) which absorb counter supporting forces are provided in the area of the juncture between the parts (1, 7) that fit together. Indication boreholes (19) which are provided for indicating a leakage and which terminate on an outer surface are assigned to said supporting surfaces. The inventive engine is characterized in that coolant is reliably prevented from seeping out or combustion gases are reliably prevented from leaking. To these ends, a sealing device assigned to the cooling channel is designed as a circular flat sealing ring (17) which is placed between the supporting surfaces (9, 10). A circular channel system (18) which interconnects the lateral flanks of the flat sealing ring that are located on the side of the supporting surfaces is assigned to said ring, and the indication boreholes (19) communicate with the channel system.

Description

Machine, preferably a reciprocating piston machine

The invention relates to a machine, preferably a reciprocating piston machine, with two intermeshing parts, in particular a large two-stroke diesel engine with at least one cylinder provided with an outlet opening which can be controlled by an outlet valve and which has a cylinder head into which a seat part associated with the outlet valve and containing the outlet opening is inserted is provided in the area of the joint between the intermeshing parts with a coolant to which a coolant can be applied, sealing said sealing ducts, offset in the axial direction with respect to one another, and the mutual supporting forces receiving support surfaces, to which indication holes ending on an outer surface are assigned to indicate a leak.

In a known two-stroke large diesel engine of the type mentioned above, the cylinders of which each have an outlet opening provided in the cylinder head, which can be opened or closed by an associated exhaust valve, is in the cylinder head the seat part which interacts with the exhaust valve and is penetrated by the outlet opening and is supported with a horizontal support surface on an associated support surface of the cylinder head. The seating area of the seat part is cooled. For this purpose, a circumferential cooling channel is provided in the area of the joint between the seat part and the cylinder head, to which cooling water can be applied. Above and below the cooling channel are provided in a circumferential groove of the seat part, designed as so-called O-rings, which are intended to seal the cooling channel. However, due to the high temperature stress, it can happen that the lower O-ring near the combustion chamber in particular is damaged and therefore leaks. The consequence of this is that cooling water can get into the combustion chamber, which is extremely undesirable and can lead to rapid wear of the running surface of the cylinder liner. There is also the risk that hot combustion gases can penetrate into the cooling channel, so that the cooling effect is lost. These dangers become particularly acute when the seat surfaces do not lie exactly against one another, for example due to foreign body particles, such as carbon particles, which have got between the seat surfaces.

The indication holes indicate such leaks. Nevertheless, there is a risk that the above-mentioned type of destruction has already occurred before such notification. Apart from that, cooling water leaking from the indication holes not only leads to a loss of cooling water, but also to wet the machine room, which is also undesirable.

Proceeding from this, it is therefore the object of the present invention to improve an arrangement of the type mentioned at the outset with simple and inexpensive means in such a way that high operational reliability is achieved.

This object is achieved according to the invention in that a sealing arrangement assigned to the cooling duct contains a circumferential flat sealing ring inserted between the support surfaces, to which a circumferential duct system connecting its side flanks on the support surface side is assigned, with which the indicator holes communicate.

With these measures, the disadvantages of the known arrangements described above are completely avoided. The flat sealing ring inserted between the support surfaces provides a high level of security against leaks. The flat sealing ring can be designed in a simple manner in such a way that foreign matter particles, such as carbon particles, etc., can be pressed in, so that a gap is definitely not formed. A material with a comparatively high temperature resistance can also be used to form the flat sealing ring. This enables the operating temperatures to be increased, which has an advantageous effect on the efficiency which can be achieved. It is preferably sufficient if the sealing arrangement assigned to the flat sealing ring is only that Contains flat sealing ring. No other sealants are required.

Advantageous refinements and appropriate further training of the higher-level measures are specified in the subclaims. In the case of a two-stroke large diesel engine of the type mentioned at the outset, the flat sealing ring inserted between the support surfaces can expediently be assigned to the lower, combustion chamber-side sealing arrangement of the cooling channel, preferably form it, since this seal is exposed to a greater temperature load than the upper seal removed from it. This can simply be designed as an O-ring.

Another expedient measure can be that the flat sealing ring is designed as a metal ring. This allows the properties mentioned above to be realized in a very simple manner. A copper alloy or a comparatively soft steel alloy can expediently be used to form the flat sealing ring. In this way it can be ensured that the flat sealing ring is elastically and easily plastically deformable under the effect of the operating forces. This ensures reliable tightness even in the event of unevenness, etc.

In a further development of the higher-level measures, the flat sealing ring can be provided with a plurality of through slots separated from one another by webs to form the channel system. These result in comparatively large, to the Cross-sections connected to the indication between the bottom and top of the flat sealing ring, which leads to a quick indication in the event of leakages.

Another advantageous embodiment can consist in that the flat ring for forming the channel system is provided on both sides with circumferential grooves which are connected to one another by connecting recesses passing through the common groove bottom. The production of circumferential grooves is comparatively simple, so that it is comparatively small The common groove base also ensures reliable stability in the radial direction.

A particularly stable flat sealing ring can be achieved in that, in order to form the channel system, circumferential channels are cut into the seat part and the cylinder head on the support surface side, which are connected to one another by recesses in the flat sealing ring.

Further advantageous refinements and expedient further developments of the superordinate measures are specified in the remaining subclaims and can be found in more detail in the following description of the examples with reference to the drawing. In the drawing described below:

FIG. 1 shows a section through the cylinder head of a cylinder of a large two-stroke diesel engine,

FIG. 2 shows a plan view of a flat sealing ring according to the invention,

FIG. 3 shows a cross section through the flat sealing ring according to FIG. 2,

Figure 4 shows a cross section through another embodiment of the flat sealing ring and

Figure 5 shows a cross section through another

Embodiment.

The main field of application of the invention is cylinder heads of two-stroke large diesel engines, in which the cylinders are provided with outlet openings which are provided in the region of the cylinder heads and can be controlled by a respectively assigned outlet valve. The basic structure and the mode of operation of such motors are known per se and therefore require no further explanation in the present context.

The cylinder head 1 of a large two-stroke diesel engine indicated in FIG. 1 is not shown in detail Cylinder liner fitted. The cylinder head 1 is provided with a comparatively large diameter, central outlet opening 2, to which an exhaust port 3 is connected. The outlet opening 2 can be opened or closed with respect to the cylinder chamber 5 by means of an associated outlet valve 4. The valve disk of the exhaust valve 4 is provided with a truncated cone-shaped contact surface 6, which is associated with a conical seat 8 which is molded onto a seat part 7 which is inserted into the cylinder head 1 and is penetrated by the exhaust port 2.

The cylinder head 1 and the seat part 7 inserted therein are held together by anchors, not shown, and are provided with mutually associated, horizontal support surfaces 9, 10 for transmitting the mutual support forces. To form the support surfaces 9, 10, the cylinder head 1 is provided with an upward step and the seat part 7 with a downward step. The mutual contact surfaces 6, 8 of exhaust valve 4 and seat part 7 are exposed to high mechanical and thermal loads. The contact surfaces can therefore be provided with an armor 11 consisting of a special material. At the same time, the seating area of the seat part 7 is cooled by means of a coolant.

For this purpose, a circumferential cooling channel 12 is cut in the area of the approximately cylindrical joint between the cylinder head 1 and the seat part 7 above the support surfaces 9, 10. This is through mutually facing, circumferential recesses of the Inner circumference of the cylinder head 1 and the outer circumference of the seat part 7 are formed. As can be seen on the left in FIG. 1, the cooling channel 12 can be supplied with a circulating coolant, normally cooling water, through supply and discharge lines. From the cooling channel 12 also branch holes 14 indicated on the left in FIG. 1 extend into the seating area of the seat part 7.

The cooling channel 12 is sealed in the axial direction by an upper and a lower sealing arrangement. The upper sealing arrangement remote from the combustion chamber is designed as an O-ring 15, which is inserted into a circumferential groove 16 cut in the area of the outer circumference of the seat part 7 and cooperates with the cylindrical inner circumference of the cylinder head 1. To form the lower sealing arrangement close to the combustion chamber, a circumferential flat sealing ring 17, which is inserted between the support surfaces 9, 10 and has a cross section that appears as a flat rectangle, is provided in the example shown. The thickness of the flat sealing ring is approximately 2 mm. Of course, in addition to the flat sealing ring 17, it would also be conceivable to provide further sealing means, such as an O-ring etc. arranged upstream of this.

The flat sealing ring 17 arranged between the support surfaces 9, 10 suitably consists of a comparatively soft steel alloy or a correspondingly soft copper alloy. In any case, this is a relative to the base material of the cylinder head 1 or the seat part 7 comparatively soft metal. In terms of strength, this should be such that it is elastically and to a small extent plastically deformable under the action of the forces occurring during operation. This allows a tight, sealing contact of the lateral contact flanks of the flat sealing ring 17 on the facing support surfaces 9 or 10 even if there is a certain surface roughness and / or foreign particles etc. between the surfaces mentioned. The deformability mentioned therefore simplifies production and assembly.

Although the flat sealing ring 17 ensures a high level of reliability, an indicator device is provided to increase the security, by means of which a leak can be indicated. The indication device contains a channel system 18, which connects the flat sealing ring 17 and connects the upper and lower joints between the lateral contact surfaces of the flat sealing ring 17 and the support surfaces 9, 10 facing them, with which the indication holes 19, which end on a visible outer surface and which are shown on the right in FIG. 1, communicate , Expediently, a plurality of indication bores 19 distributed uniformly over the circumference are provided.

These are arranged here in the seat part 7 and end in the region of the upper side of the seat part 7 radially outside the outlet duct housing 20 attached to the seat part 7. This has a collar comprising a collar of the seat part 7. In the area of the mouth of the indication bores 19 there is therefore a circumferential annular space 21, which is clearly visible from the outside. Liquid or escaping combustion gases emerging from the indicator bores 19 into the annular space 21 can therefore be quickly recognized with appropriate observation. The escaping leakage fluid can cause the machine parts surrounding the annular space 21 and the machine room to be wet. However, this case practically does not occur due to the high reliability of the flat sealing ring 17.

The flat sealing ring 17 can be provided to form the channel system 18, as can best be seen from FIG. 2, with a plurality of archers 23 separated from one another by narrow webs 22, which, according to FIG. 3, extend over the entire thickness of the flat cooking ring 17 and accordingly its underside and Connect the top together. In the example on which FIG. 2 is based, four archers 23 each assigned to a quadrant and four webs 22 are provided. With an inside diameter of the flat sealing ring of about 200 mm, the clear width of the arc slots 23 is about 2 mm, that is about 1% of the inside diameter. The width of the webs 22 can also be 2 mm, ie approximately 1% of the inside diameter.

The archers 23 are, as can be seen further in FIG. 2, expediently in the region of the radially inner half of the width of the flat sealing ring 17. This results in a wide, radially outer sealing surface 24. Since the archers 23 establish a connection between the underside and the top of the flat sealing ring 17 . any leakage liquid or leakage gases in each case get into the indication bores 19 starting from the top of the flat sealing ring 17, irrespective of whether the leakage occurs in the area of the bottom or the top of the flat sealing ring 17.

In the embodiment according to FIG. 4, the flat sealing ring 17 is provided on both sides with circumferential, mutually opposing grooves 25 which are connected to one another by bores 27 penetrating through the common groove bottom 26. This design results in a higher strength in the radial direction. Here too, a comparatively wide, radially outer sealing surface 24 can be provided. The axial thickness of the flat sealing ring 17 is 2 mm, ie just about 1% of the inside diameter. The radial thickness is 26 mm, which is a little less than 10% of the outside diameter.

In the embodiment according to FIG. 5, the cylinder head 1 and the seat part 7 are provided with mutually opposing, circumferential grooves 28 which interrupt the support surfaces 9, 10. The flat sealing ring 17 is provided with through holes 29 through its thickness, so that there is also a channel system connecting the top and bottom of the flat sealing ring 17 with which the indication holes 19 can communicate.

Claims

Expectations

Machine, preferably a reciprocating piston machine, with two intermeshing parts, in particular a two-stroke large diesel engine with at least one cylinder provided with an outlet opening (2) which can be controlled by an outlet valve (4) and which has a cylinder head (1) into which an outlet valve (4) assigned, the outlet opening (2) containing seat part (7) is inserted, in the region of the joint between the interlocking parts (cylinder head 1, seat part 7) a coolant (12) which can be acted upon with a coolant, displacing it and displacing it in the axial direction

Sealing arrangements and the supporting surfaces (9, 10) receiving the mutual supporting forces are provided, to which are assigned indication bores (19) ending on an outer surface for indicating a leak, characterized in that a sealing arrangement assigned to the cooling channel is inserted between the supporting surfaces (9, 10) , encircling flat sealing ring (17), to which an encircling channel system (18), which connects its side flanks on the supporting surface side, is assigned, with which the indicator holes (19) communicate.

2. Machine according to claim 1, characterized in that the flat sealing ring (17) consists of a material which is elastically and easily plastically deformable under the action of the operating forces.

3. Machine according to one of the preceding claims, characterized in that the flat sealing ring (17) is lined as a metal ring.

4. Machine according to one of the preceding claims, characterized in that the flat cake ring consists of a copper alloy or a soft steel alloy.

5. Machine according to one of the preceding claims, characterized in that the flat sealing ring (17) for loading the channel system (18) is provided with a plurality of archers (23) separated from one another by webs (22) and continuous over its height.

6. Machine according to one of the preceding claims 1 to 4, characterized in that the flat sealing ring (17) for forming the channel system (18) is provided on both sides with circumferential grooves (25) through the common groove bottom (26) penetrating connection recesses ( 27) are interconnected.

7. Machine according to one of the preceding claims 1 to 4, characterized in that the two, intermeshing Teüe (Zyünderkopf 1, Sitzteü 7) for loading the channel system (18) support surface side, circumferential channels (28), which through the height of the support ring (17) through recesses (29) are interconnected.

8. Machine according to one of the preceding claims, characterized in that the flat sealing ring (17) büein the associated sealing arrangement.

9. Machine according to one of the preceding claims, characterized in that in the case of a two-stroke large diesel engine, the flat sealing ring (17) inserted between the support surfaces (9, 10) is assigned to the lower, combustion chamber-side sealing arrangement of the cooling chimney (12), preferably this sealing arrangement.

10. Machine according to claim 9, characterized in that the combustion chamber distant sealing arrangement of the cooling channel (12) is grooved as a circumferential O-ring.

11. Machine according to one of the preceding claims, characterized in that in a two-stroke large diesel engine, the seat (7) with the cooling channel (12) outgoing cooling holes (14) extending into the seating area is provided.

12. Machine according to one of the preceding claims, characterized in that in the case of a two-stroke large diesel engine, the supply and discharge lines (13) assigned to the cooling channel (12) are arranged in the cylinder head (1).

13. Machine according to one of the preceding claims, characterized in that in a two-stroke large diesel engine, the indication bores (19) are arranged in the seat panel (7) and in a radially encompassing one of the connection channel areas (20) attached to the seat panel (7) End area of the top of the seat panel (7).