Cast Oil Pan for Internal Combustion Engine

The present invention relates to a cast engine oil pan for an internal combustion engine which is designed to facilitate draining of the entire oil pan while maintaining a seal between the sump and the pickup tube, the pan having a particular configuration of integral passages therein to allow for reversibility of the pan to accommodate for front or rear sump applications.

Commonly, internal combustion engines employ a separate pick-up tube completely divorced from the oil pan. Such a pick-up tube is manufactured from multiple components and is then attached to the engine using a separate gasket or seal and required fasteners. Some engine oil pans have been manufactured that incorporate some form of integral oil pick-up tube or passage. Most such attempts have in fact used a separate tube that is welded or otherwise attached permanently to the oil pan. As such these previous designs do little to reduce either the total numbers of components, the number of possible leak paths, or the alignment difficulties associated with multiple components.

In U.S. Pat. No. 4,479,463, there is provided a reversible oil pan having a pair of integrally cast vertical suction passage which are located in the side walls of the pan and which have upwardly opening galleries extending from the vertical passages to diagonally opposite corners of the pan for engagement with a pick-up channel in the crankcase. However, the upward opening galleries would appear to present a sealing problem, potentially resulting in the oil pump starvation.

Accordingly, it is a primary object of the invention described and claimed herein to provide an oil pan for an internal combustion engine having cast, integral oil pick-up passages, thereby producing a one piece design and reducing the number of potential leak points and assembly alignment issues.

Another object of the invention is to provide an oil pan having cast passages which is reversible to accommodate front and rear sump applications.

A further object of the invention is to provide an oil pan incorporating structure therein which prevents sludge accumulating at the bottom of the oil pan from being ingested into the engine.

Still another object of the invention is to provide an oil pan having the passages arranged to allow all fluid chambers to be completely drained by means of a single drain plug.

These and other objects are specifically met by the cast oil pan of the present invention wherein a suction passage is integrally formed in the oil pan and extends to outlets disposed respectively at a transversely centered position at each end of the oil pan. The suction passage has screened window inlets disposed in the sump portion of the pan adjacently above the bottom surface to permit coarsely filtered oil to enter the suction passage. A drain passage is further integrally cast in the oil pan below the suction passage in the region of the drain plug and a drain hole extends between the suction passage and the drain passage to permit the suction passage to be drained along with the oil in the sump. A single drain plug seals both a drain hole in the bottom of the drain passage of the oil pan and the drain hole between the bottom of the suction passage and the drain passage to prevent solids accumulating in the drain passage from being ingested into the engine through the suction passage.

Other objects and advantages of the invention will become more apparent upon perusal of the detailed description thereof and upon inspection of the drawings in which:

FIG. 1 is a side view through an oil pan made in accordance with the teachings of the present invention shown mounted to a portion of an internal combustion engine in a rear sump position;

FIG. 2 is a side view through an oil pan made in accordance with the teachings of the present invention shown mounted to a portion of an internal combustion engine in a front sump position;

FIG. 3 is a plan view of the oil pan of the present invention;

FIG. 4 is a longitudinal partly-exploded cross-section through a portion of the oil pan channel incorporating the plug taken along the line 4--4 of FIG. 3; and

FIG. 5 is a transverse cross-section through the oil pan channel incorporating the plug and taken along the line 5--5 of FIG. 1.

Referring now to the drawings in greater detail, there is illustrated in the drawings a reversible, completely drainable, cast oil pan for an internal combustion engine made in accordance with the teachings of the present invention and generally identified by the reference numeral 10.

As shown in FIGS. 1 and 2, the oil pan 10 may be used for front sump applications as well as rear sump applications by merely reversing its longitudinal alignment relative to the engine crankcase generally identified as 26. Such reversibility is provided by the provision of a transversely-centered suction passage 12 integrally cast into the oil pan 10 which runs along the bottom surface 28 thereof the length of the pan 10 from a shallow end 14 to a deep sump end 16 thereof and up the interior sides of end walls 18 and 20, respectively, to form an oil outlet 30 at each end of the suction passage 12, one of which communicates with an oil pump oil intake 22 in a bottom surface 24 of an engine 26 and the other of which may be open.

The suction passage 12 is a hollow cast tubular structure having its bottom wall in most places coincident with the bottom surface 28 of the pan 10. However, as best seen in FIG. 5, in the lowermost oil holding or sump area 32 at the sump end 16 of the oil pan, a drain passage 42 to be discussed below is cast between the suction passage 12 and the bottom surface 28 of the oil pan.

To provide access for oil entrained within the sump area 32 to enter into the suction passage 12, at least one window inlet 34 is provided in the side portions 40 of wall 36 defining the hollow tubular sump passage 12 at a selected level adjacently above the bottom surface 28 of the oil pan 10 but substantially below the normal oil level in the sump area 16. Since the oil collected in this sump area may contain larger particulates and metal debris which should not enter the engine oil pump, the window inlet 34 is covered with mesh screen 38 (FIG. 4) to provide a strainer to keep such larger particulates and metal debris from being sucked into the passage 12. Further, the window 34 is set a predetermined height above the bottom surface 28 of the oil pan to keep as much sludge as possible from being sucked into the engine 26 as well. In the particular embodiment disclosed, the passage 12 is shown to have a generally rectangular cross-section, and a screened window 34 is provided in each sidewall 40 of the passage 12.

From looking at FIGS. 3, it will be seen that the suction passage 12 divides the bottom surface 28 of the oil pan 10 into two halves up to the vertical extent of the suction passage 12. This poses a problem in the sump area 32 when oil is to be completely drained from the pan 10. In this respect, oil must be drained from the suction passage 12 in the area below the window and must also be drained from the sump area 32 to either side of the passage 12.

As shown in FIGS. 4 and 5, the problem presented is simply alleviated in the present embodiment of the pan 10, by providing a single, tiered, drain port configuration 40 including the drain passage 42 beneath the suction passage 12 which empties the pan 10 entirely, and a drain hole 43 which empties the entire content of the passage 12.

In this respect, in the sump area 32 of the pan 10, a drain passage 42 is created which extends to either side of the passage 12, tunneling under the passage 12 and terminates centrally therebeneath in a drain port 41 which is disposed directly beneath and in axial alignment with a cooperating drain port 43 of smaller diameter provided in a bottom wall 46 of the passage wall 36 in the area above the drain passage 42.

Thus, a single drain plug 52 can be used for engaging the tiered port configuration 40, the port 41 of the depression 42 being sealed completely and the port 43 of the passage 12 merely being closed off without sealing by the insertion of the end 50 of the plug 52 thereinto to keep sludge and debris on the bottom of the oil pan from being sucked into the suction passage 12. The drain plug 50 may be of a conventional magnetic type configured to accommodate the tiered port configuration 40.

Thus, a completely drainable, reversible cast oil pan is provided which has an integrally cast oil pick-up passage thereby resulting in a one-piece design, eliminating separate additional components previously required and assembly alignment issues associated therewith and reducing the possible points of leakage. It will be evident to those of ordinary skill in the art that various modifications and alterations may be made in the embodiment of the invention disclosed herein without departing from the inventive teaching herein. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims.