DE2146153B2 - Cylinder liner for an internal combustion engine - Google Patents

Description

Weight percent

Molybdenum 65 to 90

Nickel 7 to 25

Chromium 1 to 6

Boron 0.3 to 1.5

Silicon 0.2 to 1.5

Remainder iron with minor
Amounts of carbon and
cobalt

and in a manner known per se by plasma arc flame spraying is upset.

2. Cylinder liner for an internal combustion engine according to claim 1, characterized in that that the refractory metal alloy in the grooves (29) consists of

Weight percent

Molybdenum 75

Nickel 17.5

Chromium 4.12

Boron 0.94

Silicon 1

Remainder iron with small amounts
of carbon and cobalt.

The invention relates to a cylinder liner for an internal combustion engine for use in Connection to a piston, the stroke of which ends near one end of the cylinder liner, wherein the piston has a plurality of axially spaced piston rings, which slide along the running surface of the cylinder liner during the stroke, the cylinder liner has a groove zone on its running surface in the area of the piston rings at their dead center, which surrounds at least one of the piston rings at the dead center of the stroke and which has a through one Flame spray applied refractory metal alloy is filled, which is bonded to the cylinder liner is, wherein the metal alloy has an inner diameter that corresponds to the inner diameter of the Tread matches.

Cylinder liners of internal combustion engines generally consist of gray cast iron with a carbon content of about 3 to about 3.5 ⁰ , a silicon content of about 1.8 to 2.20 0, a manganese content of about 0.60 to about 1.00 ⁰ Zo, a maximum sulfur content of about 0.15%> and a maximum phosphorus content of about 0.15%. Typical gray cast iron alloys for cylinder liners of internal combustion engines are those of the following composition:

Total carbon content Silicon content Manganese content Maximum
Sulfur content Maximum
Phosphorus content 3.10 to 3.40
3.00 to 3.30 1.90 to 2.20
1.80 to 2.10 0.60 to 0.90
0.70 to 1.00 0.15
0.15 0.15
0.10

These cylinder liners are subject to the greatest wear when the internal combustion engine is in operation at the ends of the stroke, especially at the point where the piston is in its dead center is located. In the dead center of the piston stroke, the direction of movement of the piston is reversed around, causing the piston to vibrate, so that the greatest side load at this point acts on the cylinder wall.

In order to counteract this wear, the proposal has already been made that the bore should be limited Wall of the cylinder liner at this point with a coating made of a hard, wear-resistant Metal, such as B. chrome, or a metal alloy with a greater wear resistance than the gray cast iron usually used. Have such cylinder liners however, they have the disadvantage that they are very expensive and very difficult to grind. It was already tried to reduce the wear and tear of the cylinder liners in the immediate vicinity of the top dead center of the top To counteract the piston ring that grooves over the entire length of the cylinder running surface provided, which are filled with metal by spraying or electrical deposition (cf. U.S. Patents 2,108,392 and 2,292,662).

From the German utility model 1 682 765 it is already known at the end of the cylinder liner to attach a groove zone for an internal combustion engine in the area of the top dead center of the piston, which is filled with a refractory metal alloy applied by flame spraying and has an inner diameter which corresponds to the inner diameter of the cylinder liner. Furthermore, it is already known from the journal »technica«, 1971, p. 17, the wear resistance of cylinder liners by applying wear-resistant alloy coatings after To improve plasma arc flame spraying processes, while following a proposal made in the German patent application St 2741 a / 46 el a cylinder liner with a porous barrel

surface is provided made of hard chrome, which one according to The cylinder liner according to the invention has

The cylinder liners known up to now were subjected to a tolerable electrochemical treatment

will open. the advantage that they are in the greatest wear

These known proposals for solving the problem of the groove zone exposed to a wear-resistant membrane the production of a cylinder liner for 5 tallüberzug, which is not only very solid on the an internal combustion engine that adheres to the pad placed on it, but also easily grinds itself Requirements suffices, but does not take into account and those to achieve a sufficient the difficulties encountered in grinding the lubricating effect required favorable porosity, wear-resistant coating occur and has, which extends over the entire depth of the central zone also take no account of the importance of the io stretches and therefore extends even with prolonged operation Porosity of the wear-resistant coating that breaks up the internal combustion engine as a result of this must, in order to have a sufficiently thick oil film on tendency increasing unavoidable wear the coating to achieve sufficient not changed. The cylinder lubrication according to the invention maintain. All of the feeder bushings that have had a devious, wear-resistant coatings and process 15 wear-resistant metal coating of the above Ren for the application of these coatings lead to any composition, have a far largest not a cylinder liner for a longer service life than conventional cylinder liners internal combustion engine, which in addition to sufficient wear and tear and a lower tendency to seize the KoI wear resistance at the critical points also the benringe, since they are at the critical points in the desired porosity to achieve a sufficient upper part of the lining against high temperatures has oil adhesion, is easy to sand and is durable.

adheres sufficiently firmly to the surface. While embodiments of the invention are in the

in "Werkstattstechnik", 1965, Issue 12, p. 603 bib drawing and are in the following next

606, it should be noted that certain wear and tear is described. It shows

solid alloys instead of flame spraying by 25 F i g. 1 a section through part of a

Plasma arc flame spraying are applied to the internal combustion engine with a cylinder liner

can, from the application of this application method of the invention, which the positions of the piston in

for the production of cylinder liners, in which the cylinder liner at the ends of the piston

shows the porosity to achieve the desired oil adhesion stroke,

ability plays a decisive role, is 30 F i g. 2 shows a partially broken away section

but not the talk. through the cylinder liner of FIG. 1,

The object of the present invention is now to provide F i g. 3 another embodiment of a cycle

a cylinder liner for a combustion engine liner according to the invention in section,
gate, which is indicated at the points of the highest point in Fig. 1 of the drawing with the number 10

wear has a coating that not only the 35 generally a part of an internal combustion engine with

Requirements placed on him with regard to the connection an engine block 11 with a bore 12 denotes

wear resistance is sufficient, but at the same time that of the net. by a cylinder liner 13 of the invention

Achieving a sufficient lubrication effect is lined. A piston 14 is slidable in

Has such porosity, is easy to grind and the cylinder liner 13 is arranged and moved

firmly adheres to the base. 40 deviates from a top dead center position, which is

According to the invention, this task is represented by drawn lines, to a lower dead solution, that in a cylinder liner for a dot position, which is shown in dashed lines. Internal combustion engine of the type mentioned at the beginning, the cylinder liner 13 is a gray cast iron tube 15 The grooves of the cylinder, which are exposed to the greatest wear, have an outwardly protruding flange 16 on the cable liner with a certain refractory 45 nem upper end. The shaft of the cylinder liner Metal alloy filled, which consists of 13 is inserted into the bore 12 of the engine block 11

Percent by weight pressed, and the flange 16 sits in a AusMolybdenum 65 to 90 recess 12 A on the top of the engine block

Nickel 7 to 25 ^u

Cj ₁₁ -O ₁₁₁ ι J ₃ J ₅ 6 so The piston 14 has a piston head 17

g 0 3 _or projecting to 15 ^ ^{NAC bottom} piston ring belt 18 and three

'! "!! ^!'"! '"!'! '! 0 ^ 2 to {, 5 slots 19, 20 and 21. The upper annular slot 19

'' takes a wedge-shaped sealing or fire ring

^{22 aUf} " ^{The middle groove 2} ° ^{takes a U}

? niSrinH Inhiff ^ ^{22 aUf} " ^{The middle groove 2} ° ^{takes a ZWeUen}

of carbon and cobalt ^ _{wedge-shaped sealing ring} g 23. The lower groove

and which in a manner known per se by Plasmabo- 21 receives an oil control ring 24. The oil drain

gene flame spray was applied. According to a strip ring 24 comprises above and below thin, up-

In a preferred embodiment, there is the refractory measuring column ring disks 25, which are placed on a

tal alloy in the grooves of the cylinder liner for circumferential spacer 26

Bring an internal combustion engine from 6u and be tensioned by him. The outer ones

Weight percent surfaces of the rings 22, 23 and 25 slide on the

Molybdenum 75 running surface 27 of the cylinder liner 13 and then

Nickel 17.5 ßen against this.

Chromium 4.12 i _m top dead center 17, the piston head about

Boron 0.94 65 flush with flange 16 of the cylinder liner

Silicon 1 13. The bottom dead center is located

Remaining iron with small amounts of part of the piston band 18 within the range

Carbon and cobalt. of the cylinder liner shaft. The tread

27 of the cylinder liner 13 is impaired at its upper part of the cylinder liner 13.

Beveled end at 28. But the pore size distribution is also important,

The running surface 27 of the cylinder liner 13 is provided with a sufficient oil 30 if the pore size is too small, for example near the edge and in the interior with grooves 29, for example 0.01 to 0.1 micron. The grooves 29, 30 are arranged in such a way that they do not guarantee the upper sealing ring 22 in the upper dead center, while on the other hand point and the lower oil control ring 24 in the lower one with excessively large pores in the order of 2 to dead center and a little over the upper parts 10 microns there is a risk that the grinding and lower parts of these rings will be held back in these positions, which also extends inexorably. The grooves 29 and 30 can be veiled i ° is desired.

nism-moderately shallow and its depth about 0.0051 to By applying the inventively used

be about 0.025 cm. The axial expansion of the th metal alloy after the plasma arc flame

Grooves can be approximately 1.27 cm. injection process, however, a sufficient

The grooves 29 and 30 have a fireproof velvet porosity with the desired pore size enlargement.

Metal alloy obtained by plasma arc flame spraying in which the majority of the pores have a

zen has been applied, filled. The strip feed size is from about 0.1 to 2 microns. In order to

Migen fillings 31 and 32 are also one of the main difficulties with the lining

training body 15 firmly connected and form a hard eliminated, which in the previously used cover

Surface. The fillings 31 and 32 are made with the materials, namely the one that the lubrication occurred

Running surface 27 ground flush. Since the tread 20 between the wear-resistant coating and the KoI-

27 except for the gray cast iron filling surfaces, especially when starting the combustion

and the filling surfaces only have a ratio motor, in which the frictional wear is unusual

moderately small part of the total surface of the running surface is high, for materials with a smooth surface

27 make up, is through the fillings 31, 32 with surface, such as a resin chrome coating, or with

their hard surfaces do not exceed grinding using the detonation flame spraying method.

moderately difficult. materials brought is inadequate.

The wear-resistant fillings 31 and 32 made of the metal alloys of the invention are applied in a known manner according to the material used with a hard surface That the applied 3 ° alloys act, and the alloy is de-wear-resistant fillings 31, 32 the desired length of an interface, which can have a different porosity and the desired pore size distribution binding material, connected to the cylinder with at the same time good adhesion to the cylinder liner material. As shown, have bushing material. the fillings 31 and 32 are arranged so that they

For this purpose, the alloys in 35 are located on both sides of the upper fire ring 22 in the upper

Form of narrow strips in the axial direction at the dead center and on both sides of the oil control ring

sprayed and then extend with the cylinder wall 24 in the bottom dead center of the piston stroke,

Ground flush, which has the advantage that instead of having a few individual fillings 31 and

Grinding no stress deformations and from this 32 the cylinder liner 13 can also with a

resulting breaks in the bond between the filling 40 be provided with a plurality of narrower fillings,

treatment 31, 32 made of the wear-resistant metal alloy which extends over the same area as the wider ones

tion and the walls of the grooves 29, 30 occur. Fillings 31, 32 extend. As shown in Fig. 3

For these reasons, the fillings 31, 32 in points have the cylinder liner formed in this way

in the axial direction a width of less than 1.27 cm. 13/1 in addition to parts that have the same

The erfindunesgemäße cylinder liner 13 may be provided 45 zugsziffer cylinder liner 13 identical

one or more fillings 31, 32 from which there are, instead of the individual groove 29 at the upper end

have given material in the cylinder barrel and the single groove 30 near the lower

socket 13 are embedded flush so that they have three grooves 33 at one end, which at the upper end

or more of the sealing rings of the piston 14 are provided in, as well as three similar grooves 34, which are shown in

surround top dead center. 5o near the lower end of the cylinder liner

According to the plasma arc flame spraying method 13 are provided, each groove 33, 34 through

Ren applied leather used according to the invention - a non-recessed surface 35 of the running surface 27

alloy has a total porosity of about 15 ⁰ O is separated from the other.

The grooves 33 are distributed with the aforementioned metal lung 31, 32, with 3% of the total alloy being filled with the formation of the fillings 36, rosity from pores approximately 0.01 while the grooves 34 with the same or a T 0.1 micron, about 9.9 ⁰ Zo of the total porosity of polyvinyl dissimilar metal alloy with a size of about 0.1 to 2.0 microns and hartren th surface are filled and the fillings 37 form 2.1 ^a / o of the total porosity from pores of one size. The fillings 37 generally range in size from 2 to 10 microns. This means that the invention has the same thickness as the fillings 31 and 32, but its cylinder liner according to the invention, which is the axial width to maintain it, is 0.15 to 0.635 cm, with the surfaces 35 required to maintain sufficient lubrication being of a similar or greater width Porosity. This is extremely important in wise men. In a preferred arrangement, too great a porosity can lead to a coating with the fillings 36 and the topmost filling 37 slightly poorer surface properties, in particular 65 wider than the two other fillings 37, ie too low wear resistance, these surfaces first the respective compression during · by a too low total porosity and record the oil scraper and the Verweilzei oil adhesion and the lubrication properties thereto is greater than the other panels 37th

1 sheet of drawings

'560

Claims (1)

2 claims: 1. Cylinder liner for an internal combustion engine for use in conjunction with a piston whose stroke ends near one end of the cylinder liner, the piston has a plurality of axially spaced piston rings which slide along the running surface of the cylinder liner during the stroke, the cylinder liner on its running surface in the area of the piston rings in its dead center has a groove zone which contains at least one of the piston rings surrounds at the dead center of the stroke and which is applied by a flame spray, Refractory metal alloy is filled, which is bonded to the cylinder liner, the filling has an inner diameter that corresponds to the inner diameter of the tread, characterized in that the refractory metal alloy in the grooves (29) consists 153 /