DD213719A1 - CYLINDER LINER - Google Patents

Abstract

The invention relates to a cylinder liner for heavy-duty diesel engines. The object of the invention to develop a cylinder liner, which has a good Zaehigkeits- and elongation behavior, good thermal conductivity and good sliding and Verschleißigenschaften conventional cylinder liner materials without the use of the alloying element molybdenum and while maintaining a low-alloy lamellar gray cast iron structure in all areas of the cylinder liner is solved in that a reinforcing ring made of steel with defined dimensions in the support area of the holding collar including a transition zone in the cylinder liner shaft is arranged and enters into an intermetallic compound with the base material of the cylinder liner.

Description

IiCeI 'the JSDf charge cylinder liner

Field of application of the invention

The invention relates to a cylinder liner for Eochleistungsdieseliaotoren.

Characteristic of the known technical solutions

Increasing demands on the performance of diesel engines in high-performance diesel engines mean that the demands on the materials of certain components, xu a, for cylinder liners are always higher * The cylinder liner of a high-performance diesel engine must withstand a wide range of stresses. It must guide the piston and absorb the oscillating movements of the same »good lubricity and some oil storage capacity in the running surface of the cylinder liner necessary · .. 'Against the stress on internal pressure and temperature - the cylinder liner must be designed durably fixed« That's how it - Select the end of the motor operation. Concerns of the Federation of. Liner ge ~ gen the housing wall, "particularly negative effect in o if the strained between the cylinder head and cylinder block sliding bushing not in their starting position back again .., .- why should socket expansion and thermal conductivity, the material of 4 run are matched to such conditions . "" Under these loads occur in the collar / the cylinder liner tension peaks, which can lead to cracking in the area of the holding collar and the transition to Zylinderlaufbüchsen- 'shaft is generally known., Die.Grauguß, high-quality alloy components as-ohrom »Hickel .

Molybdenum u. a »'^;'2s'u%' Uf: ühj? EQ: f:; Vum the durability; increase the demand for capacity and mass-performance ratio.

The disadvantage here is the high cost of the alloy components and still not in each case the growing loads justifying durability.

There are also cylinder liners made of cast iron, in which the cylindrical shaft made of gray cast iron with lamellar structure and the transition region from the cylindrical shaft to the retaining collar and the retaining collar itself made of nodular cast iron

 (Information sources * DE-OS 26 54 4? 4, F02. F I / I85

DB-OS 30 21 992, Ϊ ¹ 16 J 10/04).

A disadvantage of these cylinder liners is the poor heat transfer factor, so that a sufficient heat dissipation in the highly loaded zone, d. h, in the range of Zylinderlaufbuchsenbundes, is not guaranteed. In addition, with respect to the system cylinder liner-piston-piston ring is expected to deteriorate wear properties, especially in the O ^f J? Range.

It has also been proposed to modify a cylinder liner provided with low alloy components and having a lame-hard outer cast iron structure in the üraphit structure such that the retaining collar of the cylinder liner and the transition region from the cylindrical shank; to the holding collar up to 20 % of the shaft length consist of gray cast iron with Vermiformgraphitausbildung, while the remaining sliding surface retains the known lamellar structure.

(Information source: WP K) 2 F / 246 983 1). :: '.., ·' .: can meet the perspective further increasing loads extent to which these design a cylinder liner, has yet to be confirmed by long-term stress tests. '. '' :

Object of the invention

The object of the invention is »to provide a cylinder liner for high-performance diesel engines, which allows an increase in reliability and service life while reducing the repair effort *.

Explanation of the essence of the invention

The object of the invention is to develop a cylinder liner, which has a good Zählgkeits- and Delinungsverhalten, good thermal conductivity and good sliding and wear characteristics of common cylinder liners »materials, without using the high alloying ingredient molybdenum and while maintaining a low-alloy lamellar gray cast iron structure in all areas of the cylinder liner

According to the invention this object is achieved in that a reinforcing ring is provided with a wall thickness of 20 % to 50% of the wall thickness of the cylinder liner outside im.Auflage- · region of the retaining collar of the cylinder liner and by three to five times its wall thickness in the cylinder liner shaft extends, wherein the contact surfaces of the cylinder liner and the reinforcing ring enter into an intermetallic compound, ί;

The reinforcing ring is made of steel with a strength of 500 to 700 li.mm " ² .

In addition, in a further embodiment of the invention, the entire outer surface of the cylinder liner is bath nitrided.

embodiment

The lürfindung is explained in more detail with reference to a drawing. The designation shows in section a cylinder liner 1, which consists of the Lamellargrauguß 320 Or Si 2. Sin Armierungsring 2 with a wall thickness of 40 % of the wall thickness of the cylinder liner 1 is arranged on the tension side outside in on lageber oak of the retaining collar of the cylinder liner 1 and extends four times

its y / and thickness in the cylinder barrel shaft. The reinforcing ring 2 consists of the steel material H 53 with a strength greater than 500 N.ianT ² . The reinforcing ring 2 is encapsulated during casting of the cylinder liner 1 after prior fixing with the base material, which is caused by dio high heat formation an intermetallic connection between the base material of the cylinder liner 1 and the reinforcing ring 2. The reinforcing ring 2 is arranged so that in the subsequent mechanical processing of the reinforcing ring 2 in the outer wall of the cylinder liner 1 is visible.

Subsequent bath nitriding treatment makes it possible to reduce the corrosion resistance and wear

1! 5 and strength behavior again positively influence.

Such a designed cylinder liner thus receives% in running the good JÜgenschaften the previous casting materials and in the highly stressed Zonö des-Kaltebundes the elongation and strength properties of medium steel, so that the Haltebundbareich largely the causes of the previously permanently present Anrißgefahr is eliminated.

The improved fatigue properties thus also make it possible to dispense with the expensive alloying element molybdenum.

Claims (3)

iirfindung sprue h 1. Cylinder liner for Hochleisbungsdieselraotorea, consisting of Lamellargrauguß, characterized; characterized »that a reinforcing ring (2) with a wall thickness of 20% to 50% of the wall thickness of the cylinder liner (1) is provided outside in the support region of the retaining collar of the cylinder liner (1) and by three to five times its wall thickness in the cylinder bore Buchsenschaft extends, wherein the Berühxungsflächen the cylinder liner (1) and the reinforcing ring (2) enter into an intermetallic compound * 2. Cylinder liner according to item 1, characterized in that the reinforcing ring (2) consists of steel with a strength of 500 to 700 IT · mm '* 3 cylinder liner according to item 1, characterized in that the entire outer surface of the cylinder liner (1) is bath nitrided · For this 1 sheet drawing