US3103921A - Cylinder head arrangements for internal combustion engines - Google Patents

Description

Sept. 17, 1963 H. SEIFERT ETAL 3,103,921

CYLINDER HEAD ARRANGEMENTS FOR INTERNAL COMBUSTION ENGINES Filed July 28, 1961 2 Sheets-Sheet 1 Sept. 17, 1963 H. SEIFERT ETAL 3,103,921

CYLINDER HEAD ARRANGEMENTS FOR INTERNAL COMBUSTION ENGINES Filed July 28. 1 961 2 Sheets-Sheet 2 United States Patent Ofi 3,103,921 Patented Sept. 17, 1963 ice 3,103,921 CYLINDER HEAD ARRANGEMENTS FOR INTERNAL COMBUSTION ENGINES Hans Seifert and Karl-Heinz Hoseus, Mannheim, Germany, assignors to Motoren-Werke Mannheim AG. vorm. Benz Abt. stat. Motorenbau, Mannheim, Germany, a German company Filed July 28, 1961, Ser. No. 127,574 Claims priority, application Germany Aug. 11, 1960 6 Claims. (Cl. 123-32) This invention relates to cylinder head arrangements for internal combustion engines. It is known to detachably mount the bodies of auxiliary combustion chambers on air-cooled, light-metal cylinder heads by means of fixing bolts which press the body onto the outer end face of a heavy metal ring let into a base plate of the cylinder head, the base plate forming an end of the cylinder space with which the auxiliary combustion chamber communicates via one or more transfer orifices.

In such a method of fixing, the mounting of the fixing bolts in the cylinder head offers considerable difliculties, since in operation the strength of the light metal in the region of the base plate near the transfer orifices and at the web between the valves, i.e. in the vicinity at which the fixing bolts must necessarily be screwed, is very low, due to the concentrated heat generation at these plates. Hence in the event of powerful tightening, the bolts are torn out of the light metal. This drawback may be obviated if the fixing bolts are screwed into parts of the cylinder head which are sufliciently remote from the highly heated places. In this known construction, however, a new drawback arises which is that the part of the base plate at which the combustion chamber body is applied, yields in a kind of creep process due to the continuous pressure of application and bulges towards the cylinder interior, so that the piston strikes against this part of the base plate.

According to the present invention there is provided a cylinder head arrangement for an internal combustion engine, comprising an air-cooled cylinder head that includes a base plate, an auxiliary combustion chamber body, there being an orifice for placing the chamber of said body in communication with a cylinder space of said engine, a yoke fixed in the cylinder head and including a ring supporting said body and arms extending outwardly from said ring, and fixing bolts detachably securing said body to said head, the bolts being screwed into said arms and urging said body against said ring.

In the temperature range coming into consideration the arrangement provided is practically thermally insensitive and is therefiore capable of supporting in continuous operation the stresses occurring.

A particular resistant construction of the supporting arms is obtained if the heavy metal ring terminates in, or at least approximately in, the plane of the surface of the base plate confining the cylinder space and if reinforcing and connecting ribs extend from the ring along said arms.

Leakages are obviated by the supporting arms having sleeves at the extremities thereof, into which sleeves the fixing bolts are screwed and which are completely surrounded by the light metal of the cylinder head.

Advantageously, the cylinder head is provided with projections against which the cylindrical parts of the supporting arms are pressed under the influence of the excess pressure prevailing in the cylinder space.

A connection, adequate for the present purpose, of the heavy metal ring and supporting arms with the light metal of the cylinder head can be obtained by the surface of the heavy metal ring and supporting arms having a roughness as normally produced by casting or forging.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the figures of the accompanying drawings, in which:

FIGURE 1 is a section through a cylinder head arrangement, the section being taken on the line 1--1 0f FIGURE 2,

FIGURE 2 is a section on the line 22 of FIGURE 1 and,

FIGURE '3 is a top plan view of the internal ing yoke.

As shown in FIGURES 1 and 2 of the drawings an internal retaining yoke 2, consisting of a heavy metal ring 3 and supporting arms 4, is cast in a light-metal aireooled cylinder head 1. The two supporting arms 4 respectively comprise a rib 6 and a sleeve or cylindrical part 5, and a rib 7 and a part 5. The parts 5 are connected to the ring 3 by the ribs 6 and 7 which serve as reinforcing ribs. The free end of the ring 3 terminates in the plane of a surface S of a base plate 9 which confines the cylinder space. Fixing bolts 10 are screwed into bores in the parts 5. The bolts 10 press an insert 11 on to the ring 3, the pressing force being transmitted from nuts 12 via spring packs 13, spherical washers 14, an external yoke 15, an auxiliary combustion chamber body 16 and packing rings 17 and 18. A transfer orifice 19 is situated in the insert 11, the insert 11 and the internal yoke 2 preferably being of heat-resistant steel. 20 indicates a threaded bore for the reception of an injection nozzle (not shown), which injects fuel into the pre-chamber 21. A threaded bore 24 formed in the chamber body 16 receives a glow plug (not shown) for the starting of the engine. The internal yoke 2 is cast or forged and has the rough surface which is produced by such manufacturing processes. The spring packs 13 serve to equalize the different thermal expansions of the auxiliary combustion chamber body 16 and the bolts 10. In order that the combustion pressure in the cylinder space acting on that surface of the ring 3 which lies in the plane of the surface 8 may not break loose the bond between the yoke 2 and the surrounding light metal of the cylinder head 1, parts 5 of the yoke 2 are so arranged as to bear against the lower flat surfaces of the projections 22.

We claim:

1. A cylinder head arrangement for an internal combustion engine, comprising an air-cooled cylinder head that includes a base plate, an auxiliary combustion chamber body, there being an orifice for placing the chamber of said body in communication with a cylinder space of said engine, a yoke fixed in the cylinder head and including a ring supporting said body and arms extending outwardly from said ring, and fixing bolts detachably securing said body to said head, the bolts being screwed into said arms and urging said body against said ring.

2. A cylinder head arrangement according to claim 1, wherein said arms have at the outer extremities thereof internally threaded sleeves for receiving said bolts, said sleeves being surrounded by the metal of the cylinder head.

3. A cylinder head arrangement for an internal combustion engine, comprising an air-cooled cylinder head that includes a base plate, an auxiliary combustion chamber body, there being an orifice for placing the chamber of said body in communication with a cylinder space of said engine, a yoke fixed in the cylinder head and including a ring and arms which extend outwardly from said ring, said ring being entered in an aperture in said base plate and supporting said body, an end surface to said ring, said end surface being approximately in the plane of that surface of said base plate which is remote from said body, and fixing bolts detachably securing said retainbody to said head, said bolts being screwed into said arms and urging said body against said ring.

4. A cylinder head arrangement according to claim 3, wherein said arms have at the outer extremities thereof internally threaded sleeves for receiving said bolts, and wherein there are projections on said cylinder head against which projections the sleeves are urged by the combustion gases in said space.

5. A cylinder head arrangement according to claim 4, wherein said projections extend inwardly from an interior wall of said head, said bolts passing through said projections.

6. A cylinder head arrangement for an internal combustion engine, comprising an air-cooled cylinder head that includes a base plate, 'an auxiliary combustion chamher body, there being an orifice for placing the chamber of said body in communication with a cylinder space of said engine, a first yoke fixed in the cylinder head and including a ring supporting said body and arms extending outwardly from said ring, a second yoke having apertured end portions and a central portion co-operating with said body, and fixing bolts passed through said apentured end portions and secured in said arms to cause said central portion to urge said body against said ring.

References Cited in the file of this patent UNITED STATES PATENTS 2,985,155 Hockel May 23, 1961

Claims (1)

1. A CYLINDER HEAD ARRANGEMENT FOR AN INTERNAL COMBUSTION ENGINE, COMPRISING AN AIR-COOLED CYLINDER HEAD THAT INCLUDES A BASE PLATE, AN AUXILIARY COMBUSTION CHAMBER BODY, THERE BEING AN ORIFICE FOR PLACING THE CHAMBER OF SAID BODY IN COMMUNICATION WITH A CYLINDER SPACE OF SAID ENGINE, A YOKE FIXED IN THE CYLINDER HEAD AND INCLUDING A RING SUPPORTING SAID BODY AND ARMS EXTENDING OUTWARDLY FROM SAID RING, AND FIXING BOLTS DETACHABLY SECURING SAID BODY TO SAID HEAD, THE BOLTS BEING SCREWED INTO SAID ARMS AND URGING SAID BODY AGAINST SAID RING.

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