US 3824973 A
An oil drain system for an overhead camshaft internal combustion engine includes a jet pump nozzle having an intake end in communication with the main oil gallery of the cylinder head and a nozzle end operative to direct a stream of oil under pressure into a cylinder head drain passage, whereby the drain flow of oil from the cylinder head to the engine crank case is improved.
Claims available in
Description (OCR text may contain errors)
United States Patent 11 1 Harhaus July 23, 1974 CYLINDER HEAD OIL DRAIN SYSTEM 3,008,544 11/1961 Krizman .1 184 69 Inventor: volker haus war n Mich. 3,439,703 4/1969 Toda et al. l23/l 19 B Assigneei P Corporation, Primary Examiner-Manuel A. Antonakas Dem)", Mlch- Attorney, Agent, or Firm-Paul Fitzpatrick  Filed: June 1, 1973 211 Appl. N0.: 366,002 ABSTRACT An oil drain system for an overhead camshaft internal [52 us. (:1. 123/119 B, 123/9038, 184/69 Combustion engine includes a J P nozzle having 51 Int. Cl F021 9/02 an intake end in Communication with the main Oil 5 Field f Search 123/196 M, 1 19 B, 9037, lery of the cylinder head and a nozzle end operative to 123/9033 9033; 184/69 direct a stream of oil under pressure into a cylinder head drain passage, whereby the drain flow of oil from 5 References Cited the cylinder head to the engine crank case is im- UNITED STATES PATENTS f 2,250,200 7/1941 Lowther 123/119 B 2 Claims, 4 Drawing Figures 1 CYLINDER HEAD OIL DRAIN SYSTEM BACKGROUND OF THE INVENTION The present invention relates to oil supply systems for internal combustion engines and particularly to'the oil drain portions of oil supply systems for overhead camshaft engines.
The oil provided under pressure to the camshaft bearings of an overhead camshaft internal combustion engine is generally allowed to collect on the cylinder head floor and drain from there to the crank case through suitable drain passages provided in the cylinder head and engine block. However, it is desirable in most internal combustion engines to provide venting for the gases that blow by the piston rings; and in some overhead camshaft engines the vent is provided in the cylinder head with the oil drain passages used as conduits for the upward flow of these gases from the crank case to the cylinder head. The upward flow of blow-by gases has a tendency to inhibit downward flow of oil through the oil drain passages; and in some cases it is desirable to aid this downward flow of oil to prevent excessive oil buildup in the cylinder head. The desirability is greatest at high engine speeds when the blow-by gas pressure is highest.
SUMMARY OF THE INVENTION To increase the rate at which the oil in the cylinder head of an overhead camshaft internal combustion engine is returned to the crank case, the present invention provides a nozzle, the inlet end of which is in communication with the main oil gallery of the cylinder head to receive oil under pressure and the discharge end of which is positioned to direct a stream of the oil under pressure into the upper end of one of the oil drain passages. The' stream of oil under pressure creates a reduced pressure within the oil drain passage known as the jet pump effectyand the reduced pressure aids in the drainage of oil from the cylinder head floor through this oil drain passage. The remainder of the oil drain passages are not affected and continue to conduct blow-by gases upward.
Additional features and advantages of the invention will be apparent from the following drawings and description.
SUMMARY OF THE DRAWINGS FIG. 1 is a cutaway view of a portion of an engine with an oil drain system according to the invention.
FIG. 2 is a section view along line 22 in FIG. 1.
FIG. 3 is an enlarged view of the jet pump nozzle shown in FIG. 1.
FIG. 4 shows an alternative embodiment of the jet pump nozzle shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an internal combustion engine, shown generally as 2, has a cylinder head 4 mounted atop an engine block 6. The engine block 6 contains four pistons, one of which is shown at 8. Each piston 8 carries piston rings 9 in a cylinder 10. The engine block 6 has attached to the bottom thereof an oil sump or crank case, shown schematically at 12. The top surface of each piston 8 forms with the cylinder head 4 a combustion chamber 14 in which gases are burned to supply mechanical power to the piston 8. A small portion of these gases, called blow-by gases, escapes from the combustion chamber 14 between the piston rings 9 and the walls of the cylinder 10 into the crank case area 13.
In order to supply lubricating oil to the cylinder head 4, an oil pump 32 draws oil from the crank case 12 through the conduit 34, as shown in FIG. 1 and forces the oil under pressure through another conduit 36, as shown in FIG. 2, to the main oil gallery 38 in the cylinder head 4. The pump pressure forces the oil from the main oil gallery 38 through a plurality of bearing supply passages 40 to the bearing surfaces of the journals 20. The cylinder head 4 has a floor 42 from which oil drain passages 43, 44, 45 and 46 extend downward to meet with corresponding oil drain passages 47, 48 and 49 and 50 in the engine block 6. The oil passages 44 through 50 are provided so that oil that collects on the floor 42 of the cylinder head 4 may drain to the crank case 12 and blow-by gases within the crank case area 13 may move upward to the cylinder head 4 for recirculation through the crank case ventilation system.
According to my invention, an access hole 52, as shown in FIG. 3, is drilled through the cylinder head 4 to the main oil gallery 38 from above; and a smaller diameter hole 54 is drilled from the bottom of the main oil gallery 38 toward the oil drain passage 46. A nozzle 56, having a nozzle end 58 below and an intake end 60 of enlarged diameter above, is inserted through the access hole 52 and the hole 54, into which the nozzle end 58 fits snugly, until the enlarged intake end 60 abuts the bottom of the main oil gallery 38. In FIG. 3, the nozzle 56 as shown is long enough so that, when it is in place, the nozzle end 58 projects into the interior of the oil drain passage 46. The opening of the oil drain passage 46 may be enlarged, if necessary, to accommodate the nozzle end 58.
An alternative embodiment is shown in FIG. 4. In this embodiment, the nozzle 56 is shorter so that the nozzle end 58 does not project into the oil drain passage 46.
However, the oil drain passage 46 is modified at its upper end by an oil receiving passage 64 in communication with oil drain passage 46 but aligned to better receive a stream of oil under pressure from the nozzle 56.
In either embodiment, a plug 62 is forced into the access hole 52 to close it after the insertion of the nozzle 56.
1. In an oil supply system for an internal combustion engine, the internal combustion engine including a cylinder head, a main oil gallery in the cylinder head for supplying oil therein, a floor in the cylinder head for the collection of oil therein, an oil sump below the cylinder head, pump and conduit means for supplying oil under pressure from the oil sump to the main oil gallery, one or more oil drain passages in the cylinder head having an upper end terminating at the cylinder head floor and a lower end in communication with the oil sump, the improvement comprising:
2. The improvement of claim 1 wherein the jet conduit means is a nozzle having an enlarged diameter intake end retained within the main oil gallery and a nozzle end aligned to direct a stream of oil under pressure into the one drain passage.