JP2022522478A - A device for sealing the combustion chamber of an internal combustion engine - Google Patents

Abstract

The present invention is a device for sealing a combustion chamber of an internal combustion engine, which has at least one piston and a cylindrical component for accommodating the piston, and the piston is on the upper side inside the component. It is movable alternately between the termination position of the piston and the lower termination position, and the component is attached to at least one sealing element having an abutment inserted in the groove in the region of the upper termination position of the piston. Action connectable, the sealing element is formed as a contraction sealing ring, with a molding in the region of the inner peripheral surface on the piston side, the piston is the upper end within the height of the molding. With respect to a device having a region of position.

Description

The present invention relates to a device for sealing a combustion chamber of an internal combustion engine.

The compression piston ring serves to seal the crankcase against the gas flow with respect to the combustion chamber of the internal combustion engine. This is done by a suitable piston ring mounted on the piston. The actual sealing action is caused by the formation of a hydrodynamic oil film between the piston ring and the cylinder, which is caused by the curved shape of the sliding surface and the corresponding piston speed. In this case, breaking the oil film results in hydrodynamic friction as well as mixed friction. The position of the piston ring is generally located a few millimeters below the piston crown of the piston, based on the strength of the piston by the cooling channel. This creates a so-called dead volume. This dead volume adversely affects the optimized efficiency of the system with respect to compression and gas / fuel mixing.

Automotive development and HD development typically use a system consisting of three piston rings, one oil ring and two compression rings. These piston rings seal the system against gas flow from the combustion chamber and oil flow from the crankcase, depending on the position of the piston during the stroke.

German Patent Invention No. 1930834 discloses an apparatus for deriving oil residues and combustion residues in a vertical crosshead internal combustion engine operated on a liquid fuel that is more or less prone to residue formation. ing. The device holds a stuffing box support with a stuffing box that seals the lower edge of the piston to the power mechanism chamber and seals against the piston rods that reciprocate during operation. It has an intermediate bottom and, in some cases, a valve housing located just above the intermediate bottom when the lower surface of the piston is used for compression of scavenging air. A delimiter in a mid-bottom or stuffing box support or optionally existing valve housing that acts as a power mechanism side delimiter of a protruding piston wheel or cylinder inner wall and an inner wall surface of an annular space extending parallel to it. Is equipped with a tension type or contraction type seal ring.

European Patent No. 2535540 discloses inserts for cylinders of internal combustion engines. This insert removes contaminants in the region of the topland of the piston that can be guided within the cylinder as the piston passes top dead center position. The insert has at least one first annular element that can be fixedly mounted within the radial recess of the cylinder and a radial groove of the first annular element formed in the first annular element. It comprises at least one second annular element that can be inserted therein. The second annular element is movable in the groove in the radial direction relative to the first annular element and is substantially immobile in the axial direction.

The underlying challenges of the present invention are to improve the device for sealing the combustion chamber of an internal combustion engine and adversely affect the optimized efficiency of the system with respect to compression and gas / fuel mixing mentioned at the beginning. The dead volume is structurally configured in another form.

Further, an underlying task of the present invention is to provide a sealing ring for sealing the combustion chamber of an internal combustion engine, which can optimize the so-called dead volume with respect to its adverse effects.

The above object is a device for sealing a combustion chamber of an internal combustion engine, which has at least one piston and a cylindrical component for accommodating the piston, and the piston is on the upper side inside the component. It is movable alternately between the termination position of the piston and the lower termination position, and the component is attached to at least one sealing element having an abutment inserted in the groove in the region of the upper termination position of the piston. Action connectable, the sealing element is formed as a contraction sealing ring, with a molding in the region of the inner peripheral surface on the piston side, the piston is the upper end within the height of the molding. It is solved by a device that has a positional area.

Advantageous improvements to the apparatus of the present invention can be found in the corresponding dependent claims.

The above-mentioned problem is also a sealing ring for sealing the combustion chamber of an internal combustion engine, which is formed as a contraction type sealing ring, and has upper side surfaces and lower side surfaces, and an outer peripheral surface and an inner peripheral surface. The inner peripheral surface is settled by a seal ring, which comprises a molded portion.

An advantageous improved form of the seal ring according to the present invention is described in the corresponding dependent claims.

An additional seal ring is inserted into the component surrounding the piston, such as the liner, to close the so-called dead volume between the topmost position of the top ring and the piston crown at the time of maximum compression. .. This prevents the gas / fuel mixture from entering the dead volume. Early ignition due to oil droplets cannot occur.

The seal ring is advantageously inserted into the liner groove and has an inward force component. The gap between the seal rings is exactly zero at the time of austerity. The piston crown terminates at top dead center in the middle of the austerity seal ring, and optionally the seal ring can be expanded in the direction of the liner groove if both dimensions overlap.

Depending on the subject of the invention, the following advantages:
-Reduction of dead volume-Improvement of efficiency by optimized combustion-Prevention of particle formation due to backflow gas flow-Prevention of oil droplets from scattering toward the combustion chamber.

The piston does not pass by the seal ring, but terminates at the top dead center at the seal ring, especially on the upper side surface of the seal ring.

Advantageously formed as a metal seal ring, the seal ring has a rectangular cross section. In this case, the inner peripheral surface with respect to the piston may be provided with various different geometric contours. An inner peripheral surface or a conical configuration shape formed in a tapered face shape is provided.

Similar to conventional piston rings, the seal ring built into the liner also has an upper side surface and a lower side surface. Unlike the conventional piston ring, in the seal ring according to the present invention, the outer peripheral surface certainly exists, but the molded inner peripheral surface is formed as a sliding surface with respect to the piston.

The seal ring is geometrically configured such that the area of the upper ring side surface has a smaller diameter than the area of the lower ring side surface. Therefore, during the ascending stroke, the piston slides along the inner peripheral surface (sliding surface) extending in a conical shape, and the seal ring provided with the abutment can be pressed and expanded. Based on this additional sealing location, the dead volume described above is reduced and the above-mentioned advantageous effects are obtained.

Due to the selected geometric relationship between the seal ring and the piston, the piston crown contacts the inner peripheral surface of the seal ring at the upper end point (dead center).

According to another idea of the present invention, a wear protection layer for reducing friction may be provided in the region of the inner peripheral surface (sliding surface) of the seal ring. The wear protection layer may be formed on the basis of, for example, Cr, CKS, PVD or DG.

The additional seal ring does not make its own axial motion with respect to the piston. The seal ring can move freely in the liner groove both in the axial direction and in the radial direction. In this case, the radial directional component can be formed outward only by the piston in the incorporated state.

The groove accommodating the seal ring may be machined and formed in the liner, or may be provided as a recess provided in a separate segment that can be machined and formed in the liner. If neither liner nor additional segment is given, the sealing element may be provided directly on the cylinder block.

The walls of the seal ring are limited by the wall thickness of the liner and may be individually designed (0.5-100 mm).

The object of the present invention is illustrated based on examples and described as follows.

It is a figure which shows the combustion chamber seal state including the seal ring inserted in the cylindrical component at one position of the piston arranged in this component. It is a figure which shows the combustion chamber seal state including the seal ring inserted in the cylindrical component at another position of the piston arranged in this component. It is a figure which shows the combustion chamber seal state including the seal ring inserted in the cylindrical component at the other position of the piston arranged in this component. It is a figure which shows the seal ring which is not in contact with a piston. It is a figure which shows the seal ring which is in contact with a piston.

1 to 3 show a device for sealing a combustion chamber of an internal combustion engine, which is simply shown. The following components, ie piston 1, having a plurality of grooves 2, 3, 4 for accommodating one piston ring 5, 6, 7 respectively are shown. The piston ring 7 is a conventional oil scraping ring, while the piston rings 5 and 6 are formed as compression rings. Piston 1 can move alternately between the simply outlined termination positions o, u. The piston 1 is guided between the terminal positions o and u in the cylindrical component 8. The component 8 is preferably formed as a liner in this embodiment, but may be formed by a conventional cylinder wall. The component 8 is provided with an accommodating groove 9 in the region of the upper end position o, and an additional sealing element 10 is inserted in the accommodating groove 9. The seal element 10 is formed as a contraction type seal ring formed in a rectangular cross section. The seal ring 10 has an upper side surface 11, a lower side surface 12, an outer peripheral surface 13, and an inner peripheral surface 14. In this embodiment, the inner peripheral surface 14 formed as the sliding surface is provided with a molded portion that expands in a conical shape. Radial force components are indicated by arrows. The piston 1 has a piston crown 15 on the combustion chamber side (upper end position o). The sliding surface 14 (molded portion) may include a layer 14'that reduces wear, for example, a Cr-based layer 14'. Alternative configurations based on CKS, PVD, DG are also possible.

FIG. 1 shows a position where the piston 1 is moving in the direction of the additional seal element 10 from the lower end position u, but has not yet made contact with the seal element 10. The molded portion 14 has a height h extending over the entire structural height of the seal element 10. In addition to conical moldings, curved moldings or other geometric contours are possible.

In FIG. 2, it can be recognized that the piston crown 15 is in contact with the sliding surface 14 (molded portion) of the seal element 10 in the region 16 within the height h of the seal element 10. The contractile seal element 10 is expanded (see arrow), thereby reducing the distance between the seal element 10 and the groove bottom 17 of the accommodating groove 9. In this initial contact, there is a preset spacing a between the lower side surface 12 of the seal element 10 and the piston ring 5 formed as a top ring.

FIG. 3 shows the position of the piston 1 in the region of the upper end position o of the piston 1. The distance a between the piston ring 5 and the lower ring side surface 12 of the seal element 10 is further reduced. The gap of the seal element 10, which cannot be recognized in FIG. 3, has the maximum clearance at the upper end position o of the piston 1. The contact region 16'between the piston crown 15 and the sliding surface 14 (molded portion) is located approximately at the height of the ring side surface 11 above the seal element 10.

Between the contact regions 16 and 16'shown in FIGS. 2 and 3, the combustion chamber is continuously sealed in the upper end position region o of the piston 1, so that the dead volume present in this region is reduced. At the same time, efficiency improvement can be obtained by optimized combustion. Particle formation due to the backflow gas flow is reliably prevented. The same is true for oil droplets splashing toward the combustion chamber.

4 and 5 show the seal ring 10. Aikuchi 18 can be recognized. The seal element 10 formed as a contraction seal ring is shown in FIG. 4 at a position not in contact with the piston (which cannot be seen in FIG. 4). The abutment gap FT is illustrated with its smallest dimensions.

FIG. 5 shows a seal ring 10 in contact with the piston. The abutment gap FT is shown in FIG. 5 with its maximum opening width.

1 Piston 2 Groove 3 Groove 4 Groove 5 Piston ring 6 Piston ring 7 Piston ring 8 Components (liner)
9 Accommodating groove 10 Sealing element 11 Upper side surface 12 Lower side surface 13 Outer peripheral surface 14 Inner peripheral surface (sliding surface)
14'Cr layer 15 Piston crown 16 Contact area 16'Contact area 17 Groove bottom 18 Abutment o Upper end position u Lower end position h Height Molded part FT Abutment gap

Claims (13)

A device for sealing a combustion chamber of an internal combustion engine, which has at least one piston (1) and a cylindrical component (8) for accommodating the piston (1), and the piston (1). Can move alternately between the upper end position (o) and the lower end position (u) inside the component (8), and the component (8) is the piston (8). In the region of the upper end position (o) of 1), the seal element (10) can be acted on and connected to at least one seal element (10) having a joint (18) inserted in the groove (9). 10) is formed as a contraction type seal ring, and a molded portion is provided in the region of the inner peripheral surface (14) on the piston (1) side, and the piston (1) is the molded portion (14). An apparatus having a region of the upper termination position (o) within a range of height (h). The device according to claim 1, wherein the seal ring (10) is formed as a contraction type seal ring, particularly a rectangular cross-section piston ring. The inner peripheral surface (14) of the seal ring (10) on the piston (1) side is characterized by having a molded portion extending in a conical shape or being formed as a tapered face-shaped sliding surface. The device according to claim 1 or 2. The molded portion (14) is substantially uniformly tapered in the direction of the lower side surface (12) starting from the upper side surface (11) of the seal ring (10), thereby at least the upper side. 1 to claim 1, wherein a close contact can be formed between the seal ring (10) or the molded portion (14) and the piston (1) in the region of the side surface (11). The device according to any one of up to 3. The contraction type seal ring (10) has a preset joint gap (FT), and the joint gap (FT) is formed by the ascending motion of the piston (1) and the molding of the seal ring (10). 1 to 4, which are variable in the region of the upper end position (o) of the piston (1), particularly expandable, based on the inner peripheral surface (14). The device according to any one of the above. The inner peripheral surface (14) of the seal ring (10) is characterized by comprising a protective layer (14') that reduces wear, in particular a protective layer (14') based on Cr, CKS, PVD or DG. The device according to any one of claims 1 to 5. The device according to any one of claims 1 to 6, wherein the component (8) is formed as a liner. The seal ring (10) is positioned above the piston ring formed as the top compression ring (5) toward the component member at a presettable interval, whereby the seal ring (10) is positioned. ) Is terminated at the uppermost termination position (o) of the piston crown (15) of the piston (1), according to any one of claims 1 to 7. The device according to item 1. The seal ring (10) is positioned above the piston ring formed as the top compression ring (5) toward the component member at a presettable interval, whereby the seal ring (10) is positioned. ) Is positioned outside the piston crown (15) of the piston (1), and in the region of the upper end position (o) of the piston (1), the piston crown ( 15. The apparatus according to any one of claims 1 to 7, wherein there is at least 20% overlap between the seal ring (10) and the molded portion of the seal ring (10). A seal ring for sealing the combustion chamber of an internal combustion engine, which is formed as a contraction type seal ring (10), and has an upper side surface (11), a lower side surface (12), and an outer peripheral surface (13). ), An inner peripheral surface (14), and a joint (18), and the inner peripheral surface (14) is formed as a sliding surface including a molded portion. 10. The seal ring according to claim 10, wherein the contraction type seal ring (10) is formed as a metal rectangular cross-section ring having a preset joint gap (FT). The seal ring according to claim 10 or 11, wherein the inner peripheral surface (14) includes a conical molded portion or is formed as a tapered face. The inner peripheral surface (14) is formed as a molded sliding surface, and at least the molded portion of the sliding surface (14) reduces wear particularly based on Cr, CKS, PVD or DG. The seal ring according to any one of claims 10 to 12, further comprising a protective layer (14').

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