JPS6140448A - Special form piston with piston ring - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a piston for an internal combustion engine operated on heavy oil, comprising:
It relates to a type having at least three compression rings seated in an annular groove.

PRIOR ART The present invention is based on a prior art piston with a piston ring unit in which the compression ring closest to the combustion chamber has a gas-tight abutment. However, although in pistons of such construction the gas flow can be sufficiently blocked, in practice the entire ignition pressure always acts in the radial and axial direction on the gas-tight compression ring. The mechanical load on the compression ring is extremely large.Therefore, due to the gas pressure acting on such a hermetic compression ring,
A relatively high degree of wear on the piston rings and on the cylinder running surfaces, at least in the region of the higher piston points, cannot be avoided. Also, if a gas-tight abutment is arranged on the compression ring closest to the combustion chamber, the compression in the direction towards the transmission chamber.

Each compression ring following the ring is practically not subjected to any pressure load or is subjected to only a weak pressure load, and therefore each compression ring is susceptible to so-called flapping phenomena during operation, which results in a loss of its sealing elements and oil consumption regulation. Its function as a member is almost completely lost. In this case, in internal combustion engines that run on heavy oil, residues such as soot and sulfur oxides are generated during the combustion of heavy oil, which is extremely poor in quality, and these residues are deposited on the cylinder running surface. During operation, it becomes combined with the lubricating oil present on the running surface.

Furthermore, if a gas-tight abutment is arranged on the compression ring closest to the combustion chamber, these residues are pulled away from the cylinder running surface by this ring during the working stroke of the piston, together with the lubricating oil, and thereby Relatively severe contamination of lubricating oil is almost impossible to avoid.

Furthermore, the lubricant oil produced by such residual particles has to be replaced relatively frequently with fresh lubricant oil, which increases the lubricant oil consumption of the internal combustion engine.

OBJECTS OF THE INVENTION It is therefore an object of the invention to improve the geometry of a piston of the type mentioned at the outset and the piston ring unit in such a way that, on the one hand, the desired high sealing effect is ensured and, on the other hand, the cylinder travel during the working stroke of the piston is improved. Scrape off the lubricating oil film adhering to the surface.

It is an object of the present invention to provide a lubricating oil in which the degree of contamination of lubricating oil can be kept as low as possible.

According to the invention, only the lowest compression ring towards the transmission chamber has a gas-tight abutment, while the other compression rings have a small external chamfer and a zero The compression ring closest to the combustion chamber is asymmetrically formed with a rounded transition surface towards the underside of the ring. It has an angular or spherical running surface and a non-airtight abutment. and a taper angle β of 0.5° to 2°, and a cylindrical short running surface section, with an outer chamfer or The outer surface of the web, in which the hollow groove is connected with a height of up to 40% of the height of the ring in question, and which is further located between the uppermost compression ring and the second compression ring from the bottom. distance to the cylinder running surface x 1. X27
2 is the same as or slightly thicker than the distance Xo that forms the piston play between the outer surface of the cylinder and the cylinder running surface, and the second compression ring from the bottom and the bottom The distance between the outer surface of the queso disposed between the compression ring and the cylinder running surface x 2. x 271 corresponds to approximately twice the distance between the piston outer surface and the cylinder running surface X. Furthermore, a notch formed on the circumferential surface of the piston is directly connected to the annular groove that receives the lowest compression ring, and the bottom of the notch is located between the outer surface of the piston and the cylinder running surface. The second compression ring from the bottom and one of the compression rings are located at a distance x3 from the cylinder running surface, which corresponds to about 3 to 4 times the formed distance Xo. The gas receiving volume ■2 or v2/, formed between the upper compression ring and the upper compression ring, is approximately equal to the gas receiving volume ■1 formed by surrounding the compression ring in the annular groove of the uppermost compression ring. It was resolved by doubling the value.

Embodiments In each figure, the inner cylinder surface of the cylinder or cylinder sleeve 2 is marked with numeral 1, and the piston of a two-stroke or Φ-cycle internal combustion engine that uses heavy oil as fuel is shown with numeral 3.
is attached. Further, the symbol Xo between the arrows indicates the distance between the piston outer surface Φ and the cylinder running surface 1 at which piston play should be formed. Further, the reference numeral 5 indicates an annular groove formed in the piston δ, and the reference numeral 6 indicates the annular groove formed in the piston δ, and the reference numeral 6 indicates the annular groove formed in the piston δ.
That is, it shows the compression ring closest to the combustion chamber. code 7
The annular groove 8, also formed in the piston 3, is seated in this annular groove and indicates the compression ring that is lowest in the drawing, ie closest to the transmission chamber. Reference numeral 9 also designates an annular groove formed in the piston 3, and reference numeral 10 designates the compression ring that is the second closest to the transmission chamber. In the embodiment shown in FIG. 1, the compression ring 6.8
．． 10 form one complete compression ring unit, in the embodiment shown in FIG.
and the second compression ring 10 from the bottom is arranged a further compression ring 12 which is seated in the annular groove 11, i.e. in this example the compression ring unit of the piston has four compression rings. It consists of a ring. However, the configuration of the invention is not restricted to compression ring units consisting of three or four compression rings, but can equally be implemented in pistons with more than four compression rings.

Furthermore, each drawing shows an annular groove 5 for the uppermost compression ring 6 and an annular groove 9 or 11 for the compression ring 10 or 12 which follows it in the direction to the transmission chamber. The residually formed web on the piston 3 between is indicated by the reference numeral 13, and this effect is indicated by the reference numeral X1 between the arrows.
The distance between the outer surface 14 of and the cylinder running surface 1 is shown. Furthermore, the reference numeral 15 designates a web remaining formed on the piston 3 between the annular groove 9 for the second compression ring from the bottom and the annular structure 7 for the bottom piston ring, and furthermore the reference numeral X2 or X2/1 indicates the distance between the outer surface 16 of the web 15 and the cylinder running surface 1. In the embodiment shown in FIG. 2, a web 17 is formed on the piston 3 between the annular grooves 1 and 9, and between the outer surface 16 of the web 17 and the cylinder running surface 1, A distance is formed between the arrows, indicated by the symbol X2/2.

Next, the special shape of the piston 3 and the structure of the piston ring unit according to the present invention will be described.

In the piston ring unit according to the invention, only the compression ring 8 closest to the transmission chamber, i.e. the lowest compression ring 8, has a gas-tight abutment; Shaped as a tapered ring with a taper angle α of 2° to 2° and a small external chamfer 19 on the lower side.

has been completed. The compression ring closest to the combustion chamber of the piston ring unit according to the invention has an asymmetrically angular or spherical running surface 20 with a rounded transition 21 towards the underside of the ring and a gas-tight It has a butt part that is not This abutment is not shown in the drawings, but its structure is known per se; it is a transverse slit passing radially through the piston ring, so that both ring ends meet each other with planes substantially parallel to each other. located at a distance.

The compression ring 10 of the piston ring unit according to the invention, which is the second closest to the transmission chamber, is also
As mentioned above, this chi-ξ ring also has a non-airtight abutting portion, a taper angle β from 0.5° to 2°, and a short cylindrical running surface section 22. , the lower side of this section 22 has an outer chamfered portion 23 (
In the example of FIG. 1) or the hollow groove 24 (in the example of FIG. 2) is formed with a height of up to 40% of the ring height.

According to a further embodiment of the invention (FIG. 2), the outer surface 14.16 of the web 13, 17 located between the uppermost compression ring 6 and the second compression ring 10 from the bottom. The distance X between the cylinder running surface 1 and X2/2 is the distance X that causes piston play to be formed between the screw top outer surface 4 and the cylinder running surface 1. is the same value or slightly larger.

Furthermore, the distance x2 or This value is approximately twice the distance Xo between the cylinder running surface 1 and the cylinder running surface 1. This results in an effective gas receiving volume V21V5 (in the example of FIG. 1) or V'2/21V which increases gradually from top to bottom between the individual compression rings.
2/1 + ■s (in the case of the example in FIG. 2) is formed.

Furthermore, according to the configuration of the present invention, a notch 25 is formed on the circumferential surface of the piston 30 directly connected to the annular groove 7 that receives the lowest compression ring 8, and the bottom of this notch 25 26 is spaced from the cylinder running surface 1 by a value X5 corresponding to about three to four times the distance Xo formed between the piston outer surface and the cylinder running surface 1.

Furthermore, according to the configuration of the present invention, - a gas receiving volume 2 formed between the second compression ring 10 from the bottom and the compression ring 6 or 12 located above it (example in FIG. 1); or V2/, (example in Figure 2) is twice the size of the volume 1 formed in the annular groove 5 surrounding the compression ring 6 closest to the combustion chamber. It is.

Second compression ring 10 from the bottom and bottom compression ring 8
The gas receiving volume ``5'' formed between the annular groove 5 and the gas receiving volume ``1'' surrounding the uppermost compression ring 6 is the same as, or slightly smaller than, or slightly Thick. In addition, in the embodiment shown in FIG. 2, the gas receiving volume ■2/2 formed between the top compression ring 6 and the second compression ring 12 is the same as the gas receiving volume ■2/, or smaller than that.

Distance greater than distance Xo×2. and X2/1 and X2/2, and in some cases also Xl and notch 25,
It is formed within a predetermined range by turning the piston 3.

The height of the outer chamfer 19 of the lowest compression ring 8 is 05% to 30% of the total ring height.

Furthermore, this lowest compression ring 8, like the second compression ring 10 from the bottom, has a short cylindrical running surface section, that is to say that this running surface section is designated by 27 in the example of FIG. This is shown below.

If the piston ring unit of the piston consists of three or more compression rings, for example four compression rings as shown in FIG. Each compression ring 12 arranged between the compression ring 1o that is the second closest to the device chamber has an abutment that is not airtight, i.e. this compression ring 12 has an arbitrarily formed running surface 26. It also has more.

The hollow groove 24 in the second compression ring IQ from the bottom (if this hollow groove is arranged instead of the outer chamfer 23)
As shown in FIG. 2, it has a conical annular surface or is formed from a plurality of annular surfaces located at right angles or at obtuse angles to each other.

Furthermore, as shown in FIG. 2, an annular groove 29 is turned into the piston in the area of a recess 25 arranged on the underside of the lowest compression ring 8, and an annular groove 29 is formed in this annular groove 29. ,
An oil scraping ring 30 crimped against the cylinder running surface 1 may also be attached thereto.

Due to the special construction of the piston according to the invention and the special piston ring mounting structure, the load on the compression ring closest to the combustion chamber and at the same time the load on each compression ring following this compression ring in the direction to the transmission chamber is reduced. is achieved. This largely prevents exhaust gas flow from the combustion chamber in the direction of the transmission chamber. The respective gas-receiving volume formed in the area between each compression ring is further filled and evacuated by scavenging or charging air, so that each compression ring and the annular web are kept clean and free from dirt deposits. Furthermore, the degree of heating of the abutting portions of each compression ring is also small.

Experiments have also shown that in a piston constructed and mounted according to the invention, the piston ring closest to the combustion chamber is the closest to the combustion chamber compared to a piston with a conventional ring unit having an air-tight abutment. The compression ring is pressed onto the cylinder running surface with a very low effective gas pressure, and at the same time each compression ring following it in the direction to the transmission is loaded relatively strongly (approximately twice to It has been found that it is possible to take on a gas pressure acting radially from the rear of each of these compression rings of three times the value. A further increase of approximately 40% is possible by providing external chamfers on the rings, but this is only possible if the compression ring closest to the transmission chamber, i.e. the lowest one, has an airtight abutment. This is possible only because of the pressure distribution, which, in combination with the optimum setting of the gas receiving volume between the individual compression rings, ensures good stability of the compression rings within the given annular groove. Formable.

During the entire working cycle, all the compression rings, i.e. each compression ring arranged below the compression ring closest to the combustion chamber, are also stably pressed onto the underside of the respective annular groove, which further reduces the cylinder travel. This ensures good contact of the ring running surface to the surface and thus an optimum oil scraping effect during the entire working stroke of the piston, which also results in relatively clean lubricating oil being removed from the cylinder running surface in large quantities. and sent in the direction of the transmission room.

Furthermore, the pressure loads of the individual compression rings are phase-shifted from top to bottom, and the individual gas receiving volumes v2. V2/
1. By setting V2/2 and especially (3) correctly, a gas flow in the direction from the lower side to the combustion chamber is formed inside the piston ring unit according to the present invention during the piston travel cycle. Guaranteed. This gas flow causes the dirt particles contained in the lubricating oil film still adhering to the cylinder running surface to be carried along with this film in the direction of the combustion chamber.

Effects of the Invention As is clear from the above-mentioned points, the piston having the structure of the present invention reduces the amount of oil used. It is also easily possible to keep the lubricating oil clean and regenerate even when using very poor quality fuels. −

[Brief explanation of the drawing]

The drawings show several embodiments of the invention, the first
The figure is a partial sectional view of a piston according to the invention with three compression rings, and FIG. 2 is a partial sectional view of a piston according to the invention with two compression rings. 1... Cylinder running surface, 2... Cylinder sleeve,
3... Piston, Cow... Piston outer surface, 5, 7, 9
．． 11.29... annular groove, 6, 8, 10.12...
Compression ring, 13, 15, 17... web, 14.1
6.16...Outer surface, 19.23...Outer chamfer,
20.26... Running surface, 21... Transition part, 22.2
7... Running surface division, 24... Hollow groove, 25...
Notch, 26...bottom, 30...oil scraping IJ
ng

Claims (1)

[Scope of Claims] 1. A piston for an internal combustion engine operated on heavy oil, of the type having at least three compression rings seated in an annular groove, 1. Only the bottom compression ring (8) has an airtight abutment,
The other compression ring has a small outer chamfer (19) and a 0.
It is formed from a tapered ring with a taper angle α of 5° to 2°, and the compression ring closest to the combustion chamber (6
) is a rounded transition surface (21) towards the underside of the ring.
It has a running surface (20) formed in an asymmetrical angular or spherical shape and a butt part that is not formed airtight, and has a compression part that is the second from the bottom with respect to the transmission chamber. The ring (10) has a non-hermetic abutment and a cylindrical short running surface section (22) with a taper angle β of 0.5° to 2°.
) is formed by a tapered ring having an outer chamfer (
23) or the hollow groove (24) is 40 of the relevant ring height.
% height, and the top compression ring (6) and the second compression ring from the bottom (1
0) of the web (13 or 17) located between the outer surface (
14 or 16), the distance X_1, The outer surface (16) of the web (15) arranged between the second compression ring (10) from the bottom and the lowest compression ring (8) and the cylinder running surface (1) are slightly larger. ) distance X_
2. An annular groove in which X_2_/_1 corresponds to approximately twice the distance X_0 between the piston outer surface (4) and the cylinder running surface (1) and further receives the lowest compression ring (8). (
7), there is a notch (2) formed on the circumferential surface of the piston (3).
5) are directly connected, and the bottom (26) of this notch (25) is connected to the piston outer surface (4) and the cylinder running surface (1).
) is located at a distance from the cylinder running surface (1) at a distance X_3 corresponding to approximately three to four times the distance X_0 formed between the compression ring and the second compression ring from the bottom. (10) and the compression ring (6, 12) located one above the compression ring (10).
A piston of special shape with a piston ring, characterized in that it is approximately twice the value of the gas receiving volume V_1 formed surrounding the compression ring (6) in the annular groove (5) of the piston ring. 2. Outer chamfer on the bottom compression ring (8) (
19. The piston of claim 1, wherein the height of 19) is approximately 5% to 30% of the ring height. 3. The lowest compression ring (8) and the second compression ring from the bottom (10) have a short cylindrical running surface section (27), as claimed in claim 1 or 2. Piston as described in section. 4. If more than two compression rings are arranged, the compression ring located between the top compression ring (6) and the penultimate compression ring (10) towards the transmission chamber. Each compression ring (12) has a non-tight abutment and an arbitrarily shaped running surface (26). Piston as described. 5. Instead of the outer chamfer (23), a hollow groove (24) is formed, which hollow groove (24) has a cone-shaped wall surface or a plurality of annular surfaces located at right angles or obtuse angles to each other; A piston according to claim 1, comprising: 6. An annular groove (2
9) is formed by turning, and in this annular groove (29),
2. Piston according to claim 1, further comprising an oil scraping ring (30) crimped on the cylinder running surface (1). 7. The gas receiving volume V_3 formed between the bottom compression ring (6) and the second compression ring (10) from the bottom is an annular groove for the top compression ring (6). Piston according to claim 1, wherein the piston is slightly smaller than, equal to or slightly larger than the gas receiving volume V_1 formed in (5) surrounding the compression ring (6).