US2869532A

US2869532A - Exhaust valve for internal combustion engines

Info

Publication number: US2869532A
Application number: US668385A
Authority: US
Inventors: Sourdillon Andre
Original assignee: Societe Anonime de Vehicules Industriels et dEquipements SA SAVIEM
Current assignee: Societe Anonime de Vehicules Industriels et dEquipements SA SAVIEM
Priority date: 1956-06-30
Filing date: 1957-06-27
Publication date: 1959-01-20
Anticipated expiration: 1976-01-20

Description

Jan. 20, 1959 A. SOURDILLON EXHAUST VALVE FOR INTERNAL-COMBUSTION ENGINES Filed June 27, 1957 Fig.2

lllllllm IIII///// INVENTOR Andre sourdillon W774, M Y/ML ATTORNEYS Un ed States Patent EXHAUST VALVE FOR INTERNAL- COMBUSTION ENGINES Andr Sourdillon, Saint CIoud, France, assignor to Societe Anonyme de Vehicules Industriels et dEquipements Mecaniques (Savieni-Lrs), Paris, France, a company of France Application June 27, 1957, Serial No. 668,385

Claims priority, application France June 30, 1956 1 Claim. or. 123-188) The invention relates to a valve for engines such as internal-combustion engines and Diesel engines, and more particularly to an exhaust valve.

After a certain amount of use, a deposit is formed between the valve stem and the guide thereof. This deposit is particularly harmful, since it may cause the valve stem to become jammed, or prevent it from working properly. The valve then does not close completely, which involves damage to its bearing surface and its seat by a blow-lamp effect.

The deposit produced can consist either of carbonaceous materials in the case of ordinary petrol or oil fuel, or lead in thecase of petrol containing tetraethyl lead or similar compounds.

When the fuel contains tetra-ethyl lead for example, the deposit is formed chiefly by direct projection from the gases containing lead on to the valve stem.

The invention avoids the formation of a deposit between the valve stem and the valve guide, and also prevents the end of the valve guide from being heated by the exhaust gases. The result of this is that the lubricating oil can be used satisfactorily right up to the end of the valve guide.

According to the invention, the exhaust valve for engines comprising a valve head and a stem sliding in a guide is characterised in that the stem has an annular shoulder on the portion normally situated in the guide, said stem being of reduced diameter, above said shoulder and upwards to the outside of the guide, and the said shoulder passing outside the valve guide when the valve head is in the fully lifted position, the valve stem furthermore being fast with a cup whereof the concave side is disposed towards the said guide.

Other features of the invention will be apparent from the following description of methods of embodiment given by way of example, and illustrated in the accompanying drawings.

Figure 1 illustrates a valve according to the invention, the cup and part of the valve guide being shown in section.

Figure 2 illustrates a further embodiment of a valve according to the invention, the cup and part of the valve guide being shown in section, and the valve stem being partly cut away.

Figure 3 is an axial section of the cup fitted to the valve stem illustrated in Figure 2.

In Figure 1, the stem 1 of the valve 2 slides in a guide 3. The said stern comprises a cup 4 whereof the concave side is disposed towards the valve guide 3. The cup 4 covers the end of the guide.

In addition, the diameter of the valve stem' 1 is reduced in the region 5, in the vicinity of the end of the guide 3, in order to remove any deposit produced in the guide as soon as it forms. The shoulder 6 at the base of the reduced portion serves to drive out of the guide 3 any foreign body which might become lodged there.

2,869,532 Patented Jan. 20, 1959 F. ice

The cup 4, whereof the concave side is disposed towards the guide, can be fitted to the valve stem 1 in various ways. It may be welded or brazed on, or it may be attached mechanically to the stem, by screwing or crimping.

in Figures 2 and 3 as in the case of the preceding embodiment, the valve stem comprises a region 5 of reduced diameter, bounded at the base by a shoulder 6 which serves to drive out of the bore of the guide 3 any foreign body which might become lodged there, especially a lead deposit when the petrol contains tetra-ethyl lead or similar compounds.

This deposit of foreign matter is furthermore virtually non-existent because the cup 4 is so fitted that it always covers the top end of the guide 3. As may be seen in Figure 2, the lower edge 7 of the cup 4 extends along the guide 3 beyond the shoulder 6. When the said shoulder 6 has reached its highest position as shown by a dotted line in Figure 2, the lower edge 7 of the cup still completely surrounds the end of the guide 3, and virtually prevents the gases capable of depositing lead from reaching the guide 3.

Thus if a small quantity of lead is deposited at the end of the guide 3, it is easily removed each time the shoulder 6 emerges.

In order that the cup 4 may be satisfactorily attached to the stem 1, the latter comprises a cylindrical bearing surface 8 with which is engaged a collar 9 fast with the cup 4. The collar 9 has a cylindrical bore 10 of a diameter corresponding to that of the cylindrical bearing surface 8.

For attachment purposes, the collar 9 is pierced with orifices 11, and the stem 1 is likewise pierced with orifices 12.

These

orifices

11 and 12 are disposed opposite to one another, and filled with welding material 13.

The invention allows the use of cups made of a material which is different from that of the valve, and offers a good degree of resistance to the exhaust gases. The cups can, for example, be made of a metal of appreciably better quality than that of the valves. In addition, the cups can thus be made in the most suitable shapes for guiding the gases towards the exhaust.

It has furthermore been found experimentally that valves fitted with cups according to the invention can be used for a very long time with virtually no overhaul.

During supervised trials, it has been found for example that valves .fitted with cups according to the invention had their stems absolutely intact after operating for a thousand hours, and that there was no deposit of lead or similar materials at the end of the valve guide, while the stem and guide of a valve not comprising any cup arranged according to the invention were fouled with deposits after the same period of operation.

What I claim is:

An exhaust valve for internal combustion engines having a valve head on a valve stem sliding in a guide, an annular shoulder on the portion of said stem normally situated in the guide, said stem being of reduced diameter above said shoulder extending above the end of the guide, said'shoulder passing out of the guide when the valve head is in its fully lifted position, and a concave cup fixed to said stem with its concave side disposed towards and surrounding the guide, said shoulder being situated within said cup and the end of said guide being situated within said cup when the valve is in its fully lifted position.

(References on following page) Refer'enes Cited in the file of this patent UNITED STATES PATENTS Smith Apr. 24, 1906 Dahlgren June 19, 1917 5 Shepherd Nov. 20, 1923 De'vos-et a1. Mar. 23;, 1926