DE1949256B1 - Valve arrangement of a piston internal combustion engine - Google Patents

Description

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The invention relates to a valve assembly to connect a material without the risk of a Piston internal combustion engine with a poppet valve and cracking or breaking off of the upper layer

a valve seat ring, which is made of armor together with one another.

have effective seat surfaces, of which at least preferably has the material of the outer layer

one with an armor from a layer of a 5 of the armor a corrosion-resistant surface,

metallic material is provided, the heat of which is resistant to aggressive substances, which it

Resistance and hardness is significantly greater than that which is exposed in operation, behaves inertly,

the metallic base material of the seat, and this property of the material is also

another layer of a different hard metal- the formation of deposits on the seat surface

Lischen material is available, the hardness of which is less than io largely avoided. If namely deposits

than that of the armor. arise on the valve seat, there is a risk that

It is Z. B. from the magazine "ATZ", 1936, p. 310, with the time under the influence of between the or the USA.-Patent 2 865 359 known, seat valve and the valve seat resulting impacts a surface and stem ends of valves and Valve seats part of the layer formed crumbles, whereupon hot piston internal combustion engines with armor 15 blow gases from the combustion chamber of the cylinder through a layer of a hardfacing alloy, as can. The influence of these gases, with the effect z. B. that under the brand name "Stellit" is comparable to a welding torch, leads to known material to be provided, whereby their life to a rapid destruction of the valve parts. Is significantly extended by duration. The well-known selection of the material mentioned will satisfy this armouring implementation, but it does not appear to a large extent avoided in diesel engines with heavy oil operation, in which the materials for the outer layer of the pan include high-temperature corrosion due to the erosion mentioned Have properties, a combination of vanadium, sodium and sulfur, which appears on the seat surfaces under the designation »superalloys«. It has been known high alloy metals to non-ferrous base, while trying this difficulty mm having a particularly high hardness of over 700 kp / by an esterification 25 ² HV application more resistant and have a harder Panze- and overcome nickel-based, cobalt-based or struggled. In the process, however, a tungsten base could be formed. Difficulties with the adhesion of the hard alloys to the relatively soft austenitic or ferritic base materials of the parts 30
the valve assembly. An outlet valve made of high-alloy chromium-nickel

On the other hand, from the German patent specification stahl for a diesel engine was used for an external one

748 506 a formation of seat surfaces of valve diameter of the valve plate of 130 mm with a

plates of internal combustion engines known, in which 4 mm thick layer of a hardfacing alloy

the valve disc with a stellite-like hard metal 35 can be seen, which is called "Haynes-Stellite 6"

is provided, whereupon one supplied by Union Carbide Corporation on top of this basecoat

thin layer of platinum a few microns thick.

or a platinum alloy, e.g. B. by vapor deposition on it, the valve disk was after a while Vacuum, is applied. In this version, the stellite is sandblasted and cut to 700 to Although two layers are used, the second is heated to 40 750 ° C, at which temperature an armor layer, the platinum layer, however, is so thin that it does not cover a nickel-based superalloy in the flame injection molding process was applied to ensure the strength of the sealing surface of the valve. The thickness of this ■ can contribute, and it also consists of a lining fraud after the final processing of the valve material, Platinum or a platinum alloy, the softer seat after the diamond grinding process 1.1 to is 1.2 mm than the stellite-like material below.

borrowed layer. With such a design, the materials of the valve had the following additions

thus also not the mentioned difficulty composition:

Fixed. Base material (austenitic steel):

The invention has the creation of a valve _{lg 5% c Q 45% c} ^ _{50 / gi 1ιη M g0 / M}

arrangement of the type mentioned to the goal, in which 50 ■, ₀ / -ψ j> _est p _e

the difficulties mentioned are avoided and '

in which a good connection of one to the upper intermediate layer (Stellite 6):

armor with great hardness with 28% Cr, I ⁰ I ₀ C, 4% W, the rest Co.

the basic material of the part and at the same time _armor (nickel-based superalloy):

a long service life in operation is achieved, so that 55. ■> _{0 /} " _{0 /} " _{0 /} . ".

Under certain circumstances, liquid cooling, which would otherwise be necessary, can be dispensed with ^{, which ^ ° 'D} / 0 M' ^u ' ^{y / o} ^ " ^{% ä lo ö1} ' ^ ^{5 / o re} ' ^ä ' ^{ä / o ß '.}

The valve arrangement according to the invention, by The hardness of the armor was 770 to

The hardness of the intermediate layer 400, which achieves the aforementioned goal, is 820 kp / mm ^{2 HV}

characterized in that the armor is made of a material from 60 to 450 kp / mm ² HV, the hardness of the chromium-nickel steel

With a hardness of over 700 kp / mm ² HV, the valve disk consists of 260 to 280 kp / mm ² HV.

and that the further layer between the armor valves formed in this way were in

and the base material of the seat is attached to a six-cylinder plunger-piston diesel engine

and their hardness in the range from 400 to 600 kp / mm ² HV heavy oil operation installed as exhaust valves and

and is larger than that of the base material. showed after two 1000 hours of endurance runs

Due to the design according to the invention, it is ⁵ heavy oil no signs of incipient corrosion

possible, in a reliable manner, even a very hard sion or other damage. The valves

Armor with a relatively soft base ran without any special liquid cooling.

Example 2

In essentially the same way, a valve was made from the following materials:
Base material:

Ferritic steel.

Intermediate layer (Stellite 32 from Union Carbide Corp.):

25% Cr, 1.7% C, 1% Si, 1% Mn, 1% Fe, 22% Ni, 12% W, the rest Co.

Upper armor (tungsten-based superalloy): 13% Co, 87% WC.

The upper armor was applied by flame spraying after the valve head had been preheated to 500 to 600 ^{° C.}

The valve, which was provided with a water cooling. had similar properties in operation like the valve according to example 1.

It goes without saying that in addition to the above-mentioned superalloys for the upper armor layer, too other well-known superalloys that are nickel-based, Cobalt base or tungsten base, can be used. Also for the intermediate layer materials other than those mentioned can be used.

The drawing shows a partial section of the outer edge of the valve disk of a valve designed according to the invention. The valve disk 1 with the diameter D is provided with an intermediate layer 2 and an armor 3. The greatest thickness of the intermediate layer is denoted with B , the thickness of the armor with A. In the embodiments according to the two examples, the diameter D was 130 mm, the thickness A 1.1 to 1.2 mm, the thickness B 3 mm.

Claims (9)

Patent claims: 1. Valve arrangement of a reciprocating internal combustion engine with a poppet valve and a valve seat ring, which have interacting seat surfaces, of which at least one mi * ¹ an armor made of a layer of a metallic. Material is provided whose heat resistance and hardness is significantly greater than that of the metallic base material of the seat, and another layer of another hard metallic material is present, the hardness of which is less than that of the armor, characterized in that the armor is made of one material with a hardness of over 700 kp / mm ² HV and that the further layer is attached between the armor and the base material of the seat and its hardness is in the range of 400 to 600 kp / mm ² HV and is greater than that of the base material. 2. Arrangement according to claim 1, characterized in that the material of the armor (3) has a corrosion-resistant surface, which is resistant to aggressive substances, which it is exposed during operation, behaves inertly. 3. Arrangement according to claim 1, · characterized in that the material of the armor is a is high-alloy, non-ferrous metal. 4. Arrangement according to claim 3, characterized in that the material of the armor a Nickel-based alloy is. 5. Arrangement according to claim 3, characterized in that the material of the armor a Cobalt based alloy is. 6. Arrangement according to claim 3, characterized in that the material of the armor a Tungsten based alloy is. 7. Arrangement according to claim 3, characterized in that the material of the intermediate. layer is a hardfacing alloy with a content of more than 20% of carbides of metals. 8. Arrangement according to claim 1, characterized in that the base material is an austenitic Steel is. 9. Arrangement according to claim 1, characterized in that the base material is a ferritic Steel is. 1 sheet of drawings