US3331359A

US3331359A - Cylinder head of an internal combustion engine comprising two intake and two exhaustvalves for each cylinder

Info

Publication number: US3331359A
Application number: US473614A
Authority: US
Inventors: Skatsche Othmar
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-08-21
Filing date: 1965-07-21
Publication date: 1967-07-18
Anticipated expiration: 1984-07-18
Also published as: GB1098997A; AT251352B; FR1426551A; DE1296460B

Description

July 18, 1967 O SKATSCHE 3,331,359

CYLINDER HEAD OF AN INTERNAL COMBUSTION ENGINE COMPRISING TWO INTAKE AND TWO EXHAUST VALVES FOR EACH CYLINDER Filed July 21, 1965 3 Sheets-Sheet l I. Aw;

3,331,359 PRISING 5 Sheets-Sheet 2 STION ENGINE COM FIG. 4

' IIII O. SKATSCHE III/I TWO INTAKE AND TWO EXHAUST VALVES FOR EACH CYLINDER (Ill CYLINDER HEAD OF AN INTERNAL COMBU July 18. 1967 Filed July 21, 1965 y 18, 1967 I o. SKATSCHE 3,331,359

CYLINDER HEAD OF AN INTERNAL COMBUSTION ENGINE COMPRISING TWO INTAKE AND TWO EXHAUST VALVES FOR EACH CYLINDER Filed July 21, 1965 5 Sheets-Sheet 3 United States Patent 3,331,359 CYLINDER HEAD OF AN INTERNAL COMBUS- TION ENGINE COMPRISING TWO INTAKE AND TWO EXHAUST VALVES FOR EACH CYLINDER Otllmar Skatsche, Graz, Austria, assignor to Hans List, Graz, Austria Filed July 21, 1965, Ser. No. 473,614 Claims priority, application Austria, Aug. 21, 1964, A 7,274/64 4 Claims. (Cl. 123-75) ABSTRACT OF THE DISCLOSURE A cylinder head of an internal combustion engine of which each cylinder comprises two intake valves and two exhaust valves with a reversal of the valves with every second cylinder of the engine. Four spiral ducts of the inlet ports of two adjacent cylinders each terminating in a common suction port and are arranged in a central relation to the four intake valves associated therewith.

For heavy-duty internal combustion engines generally equipped with intake valves for each cylinder assembly, vigorous and regular turbulence of the air entering the combustion chamber is of the essence. However, it is generally very difficult to suitably arrange and design twist-producing inlet ports of multiple-valve cylinder heads so as to obtain the best flow conditions possible. The reasons why previous elforts of engine builders invariably ended in some sort of compromise solution are mainly of a structural nature.

Quite a number of combinations of oblique and oblique-and-spiral ducts are already known. However, experience has shown oblique ducts to present inferior flow properties and lower twist rates than spiral ducts. Moreover, oblique ducts are much more sensitive to lack of casting precision with regard to the achievement of a uniform twist in all cylinders of a multi-cylinder engine than are spiral ducts. This sensitivity naturally affects four-valve cylinder heads, each comprising two oblique ducts at the inlet end to an even greater extent.

Similar conditions prevail also in the conventional combination of one spiral duct and one oblique duct in fourvalve cylinder heads. In order to achieve the best flow properties possible in this instance, both the intake valves and the valve seat rings of the oblique duct and of the spiral duct are inevitably of different design so as to obtain approximately identical flow conditions in both valves.

Consequently, the use of two spiral ducts in four-valve cylinder heads is desirable. Since in automotive, and in particular, in truck engines featuring two intake valves for each cylinder these are usually arranged by pairs in transverse relation to the crankshaft axis as this arrangement represents the simplest and cheapest solution with regard to the operation of the valves, it was the obvious thing to do to arrange two twist ducts extending in transverse relation to the crankshaft axis one behind the other. However, the draw-back of this arrangement resides in the fact that due to the inherent properties of spiral ducts the second spiral duct located behind the first as viewed in the direction of flow, is handicapped with regard to its flow characteristics, particularly as far as the attainable twist rate is concerned, by greater resistance to flow in the longer feed duct as compared with the first spiral duct located in front as viewed in the direction of flow.

For that reason, large-sized engine types were built wherein the intake valves are arranged in a row in parallel relation to the crankshaft axis and equipped with individual identical spiral ducts extending in transverse relation to the crankshaft axis. However, this arrangement requires a comparatively expensive and complicated valve gear for the operation of the intake and exhaust valves which is both uneconomic and hardly practicable for engine construction in view of certain design and space requirements.

It is the object of the invention to overcome the drawbacks of cylinder heads of conventional design for internal combustion engines comprising two intake and two exhaust valves for each cylinder and to improve flow conditions at the suction end. According to the invention this is achieved by the provision of spiral ducts of at least approximately equal shape and length extending in pairs as far as the top of the cylinder head where they terminate in a common suction port. This design makes for identical flow conditions in both spiral ducts as a result of which identical twist rates obtain both for the intake valves of a cylinder assembly and for all cylinders. Flow conditions are further improved by the downdraft effect produced by the vertical arrangement of the suction ports. Another advantage of the design of the cylinder head according to the invention resides in the possibility of preserving the arrangement of the intake valves in a row extending in parallel relation to the crankshaft as is customary particularly with truck engines, thereby keeping the cost involved and space required for the operation of the valves on a moderately low level.

According to a preferred embodiment of the invention, the two spiral ducts meet inside the cylinder head and terminate in a common suction port preferably located in the plane of symmetry including the crankshaft axis between the intake valves, thereby shortening the flow routes leading to the intake valves and reducing the resistance to flow accordingly.

Finally, according to the invention the location of the intake and exhaust valves can be reversed in every second cylinder, the four spiral ducts of each pair of adjacent cylinders terminating in a common suction duct preferably half-way between the respective intake valves. The combination of four spiral ducts each to form a structural unit exposed to the impact of the air not only simplifies the general design of the cylinder head but assures also absolutely identical flow conditions in the four spiral ducts.

Further details of the invention will appear from the following description of two embodiments of the invention with reference to the accompanying drawings in which:

FIG. 1 shows a horizontal cross-sectional view of a cylinder head of an internal combustion engine comprising two intake and two exhaust valves for each cylinder on line I-I of FIG. 2 representing a vertical cross-sectional view on line 11-11 of FIG. 1, Whereas FIGS. 3 and 4 show similar views of another variant of the cylinder head on lines IIIIH and lV-IV respectively,

FIG. 5 showing a vertical cross-section in transverse relation to the crankshaft axis on line VV of FIG. 3.

The illustration shown in FIG. 5 is also applicable to the variant shown in FIG. 1. The drawings show only a portion of the internal combustion engine extending apapproximately over two adjacent cylinder assemblies.

In both types of cylinder heads the cylinder fairing 2 is located atop the cylinder head 1, with a packing 4 in between, the said fairing being closed on top by a cover 3 with the insertion of a packing 5. The injection nozzle 6 of each cylinder assembly arranged in coaxial relation to the cylinder axis together with the nozzle-holder 7 enclosed in a nozzle-holder protection tube 8, is inserted in a through bore of the cylinder head 1.

Each cylinder assembly comprises two intake valves 9 and 9' and two

exhaust valves

10 and 10, both the

intake valves

9, 9 and the exhaust valves 10, 10' being arranged by pairs in planes extending in perpendicular relation to the crankshaft axis. The valve gear is located above the cylinder head 1 inside the cylinder head fairing 2 and comprises a vertically movable bridge 11 transmitting the motion of the rocker arm 12 actuated by the push rod 13 to the

valve couple

9, 9 and 10, 10, respectively.

The inlet ports 14, 14' of the

valves

9, 9 are designed as spiral ducts for the purpose of imparting an initial twist to the ingoing air for combustion and are of approximately equal shape and length so that the twist rates for the two

intake valves

9, 9 are also identical. The inlet ports 14, 14' extend in an upward direction towards the top of the cylinder head 1. In the embodiment illustrated in FIGS. 1 and 2 the

inlet ports

14 and 14 of each cylinder assembly meet inside the cylinder head 1 so as to form a common duct 15 terminating in a vertical suction port 16 defined by a tube 17 inserted in the area of the upper sealing flange of the cylinder head 1. The suction ports 16 of all cylinder assemblies are located in the plane of symmetry between the intake valves 9 and 9' including also the crankshaft axis of the engine.

Referring to the cylinder head shown in FIGS. 3 to 5, the location of the intake and

exhaust valves

9, 9' and 10, 10' respectively, of adjacent cylinder assemblies is inverted so that the

intake valves

9, 9 of each pair of adjacent cylinders can be combined so as to form a single unit for the supply of air for combustion. The inlet ports 14, 14' of each of these valve groups extend jointly in an upward direction toward the top of the cylinder head so as to form a common duct 15 also terminating in a vertical suction port 16 in the area of the upper sealing surface of the cylinder head 1. In this instance, the suction port 16 is arranged in a central relation to the associated four intake valves.

The cylinder heads hereabove described with references to the accompanying drawings are but a few examples taken from a multitude of possible embodiments of the invention. In particular, the scope of the present invention is by no means restricted with regard to the cross-sectional design of the inlet ports.

What is claimed is:

1. A cylinder head of an internal combustion engine of which each cylinder comprises two intake valves and two exhaust valves, the said valves extending in perpendicular relation to a crankshaft axis of the internal combustion engine, each of the said intake valves comprising an inlet port designed as a spiral duct, the spiral ducts of all inlet ports being of approximately the same shape and length, pairs of the said spiral ducts ascending to the top of the cylinder head and terminating there in a common suction duct, the location of the intake valves and exhaust valves being reversed with every second cylinder of the internal combustion engine, and the four spiral ducts of two adjacent cylinders each terminating in the said common suction port.

2.. A cylinder head as claimed in claim 1, wherein the said four spiral ducts of two adjacent cylinders each are located in a central relation to the four intake valves associated therewith.

3. A cylinder head of an internal combustion engine comprising a plurality of cylinders, each cylinder comprising two intake valves and two exhaust valves, the said valves extending in perpendicular relation to a crankshaft of the internal combustion engine, the location of the intake valves and exhaust valves being reversed with every second cylinder of the internal combustion engine, each intake valve comprising an inlet port designed as a spiral duct, and a suction port in the top of the cylinder head, the four spiral ducts of two adjacent cylinders each ascending to the top of the cylinder head and terminating in the said suction port.

4. A cylinder head as claimed in claim 3, wherein the said four spiral ducts of two adjacent cylinders each are located in a central relation to the four intake valves associated therewith.

References Cited UNITED STATES PATENTS 2,318,914 5/1943 Anderson et al 123-30 2,909,971 8/1959 Kauifmann et al. 123--30 X 3,020,896 2/1962 Meurer et al. 123-30 3,054,390 9/1962 Meurer et al. 123-30 3,125,075 3/1964 Wittek 123-30 3,240,190 3/1966 Christian et al. 12330 FOREIGN PATENTS 1,201,809 7/1959 France.

844,352 8/ 1960 Great Britain.

899,760 6/ 1962 Great Britain.

MARK NEWMAN, Primary Examiner.

WENDELL E. BURNS, Assistant Examiner.