Patent Document

TECHNICAL FIELD 
     The present invention relates to an oil pan having a plurality of vertical baffles which divide the oil pan into four chambers to limit oil movement during high acceleration vehicle maneuvers. 
     BACKGROUND OF THE INVENTION 
     A typical oil pan is disposed beneath a cylinder block and crank shaft of an internal combustion engine. Such an oil pan is configured to receive oil that drains or is otherwise exhausted from the cylinder block and the crank shaft and/or main bearings that support the crank shaft. The oil collects in a sump of the oil pan and is then pumped from a sump pick-up location into a lubrication system associated with the engine. The oil pan may also be provided with a horizontal baffle that inhibits oil from moving away from the pick-up location during high acceleration (i.e., “high G”) vehicle maneuvers, such as sudden turning, acceleration, or braking events. 
     The horizontal baffle may require a two-piece construction of the oil pan. The horizontal baffle is effective in limiting “sloshing” of oil during high acceleration maneuvers, but also delays the return of the oil into the sump for redistribution to the engine. The oil collects on top of the horizontal baffle and can become entrained in the crankshaft windage, which slows the flow of oil draining into the sump after it has been discharged by the engine. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved oil pan which eliminates the need for a horizontal baffle, thereby enabling a one-piece construction and reducing the cost and weight of the oil pan, as well as the quantity of oil required for the engine. 
     More specifically, the invention provides an oil pan for an engine including a body having a floor and side walls. The body has a plurality of baffles extending vertically from the floor and intersecting each other and the side walls in a manner to form four chambers. The side walls have openings to allow adequate oil flow therethrough between the chambers. One of the chambers acts as an oil pick-up chamber. 
     Preferably, the body is a one-piece cast aluminum component, and the four chambers include the oil pick-up chamber, a rear chamber, and two side chambers. One of the openings is positioned at a base of one of the baffles to communicate the rear chamber with the oil pick-up chamber, and two more of the openings are positioned at a base of another two of the baffles, respectively, to communicate the two side chambers with the oil pick-up chamber. 
     The baffles forming the rear chamber are angled with respect to the side walls and with respect to each other to form a funnel shape to direct oil toward the pick-up chamber. 
     A first of the baffles separates one of the side chambers from the oil pick-up chamber; a second of the baffles separates the other of the side chambers from the oil pick-up chamber; a third of the baffles separates the other of the side chambers from the rear chamber; a fourth of the baffles separates the rear chamber from the oil pick-up chamber; and a fifth of the baffles separates the rear chamber from one of the side chambers. The first, second and fourth baffles are sufficiently tall to prevent a substantial amount of oil from sloshing over the baffles during high acceleration vehicle maneuvers. 
     The opening in the first baffle is preferably substantially the same size as the opening in the second baffle. The opening in the fourth baffle is preferably smaller than the openings in the first and second baffles. 
     Another aspect of the invention provides an engine including an engine block having at least one cylinder and a crankshaft. A crankshaft oil deflector is positioned below the crankshaft. An oil pan is connected with the engine block closely adjacent the crankshaft oil deflector. The oil pan has a plurality of vertical baffles dividing the oil pan into four chambers, as described above. The oil pan is characterized by the absence of a horizontal baffle extending over the oil pan. 
     The above features and other features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross sectional view of an engine having an oil pan in accordance with the invention; 
         FIG. 2  is a top plan view of an oil pan and pick-up tube corresponding with  FIG. 1 ; 
         FIG. 3  is a perspective view of the oil pan of  FIG. 2 ; and 
         FIG. 4  is a cut away perspective view of the oil pan of FIGS.  2  and  3 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows an engine  10  including a cylinder block  11  having a plurality of cylinders  12 ,  13  that house a plurality of pistons  14 ,  15 , respectively. The engine also includes a crankshaft  17  that is connected to the pistons  14 ,  15  by connecting rods  18 ,  19 , respectively. The crankshaft  17  is rotatable with respect to the cylinder block  11  so as to cause the pistons  14 ,  15  to reciprocate in the cylinders  12 ,  13 . 
     Rotation of the crankshaft  17  causes air to rotate with the crankshaft. This rotating air may be referred to as “crankshaft windage.” During operation of the engine, some oil that would otherwise drain into the oil pan may instead become entrained in the crankshaft windage. Accordingly, the engine  10  further includes the crankshaft oil deflector  20  which is operative to remove oil from the crankshaft windage and drop the oil into the oil pan  30 . 
     The oil pan  30  is shown in greater detail in  FIGS. 2-4 . As shown, the oil pan  30  is preferably a one-piece cast aluminum component and includes a body  32  having a floor  34  and side walls  36 ,  38 ,  40 ,  42 . The body  32  also includes vertical baffles  44 ,  46 ,  48 ,  50 ,  52  which divide the oil pan into four chambers, including a left side chamber  54 , an oil pick-up chamber  56 , a right side chamber  58 , and a rear chamber  60 . The first baffle  44  separates the left side chamber  54  from the oil pick-up chamber  56 . The second baffle  46  separates the oil pick-up chamber  56  from the right side chamber  58 . The third baffle  48  separates the rear chamber  60  from the right side chamber  58 . The fourth baffle  50  separates the rear chamber  60  from the oil pick-up chamber  56 . The fifth baffle  52  separates the rear chamber  60  from the left side chamber  54 . 
     The baffles  44 ,  46 ,  48 ,  50 ,  52  are sufficiently tall to prevent a substantial amount of oil from sloshing over the baffles during high acceleration vehicle maneuvers. Preferably, the baffles are as tall as possible; i.e., the baffles extend to a position closely adjacent the crankshaft oil deflector  20 , as shown in FIG.  1 . 
     As shown in  FIG. 2 , an oil pick-up tube  62  extends into the oil pick-up chamber  56 , and has an oil pick-up head  64  which is positioned approximately 6 millimeters from the floor  34  of the oil pick-up chamber  56  for collecting oil from the oil pick-up chamber  56 . 
     As shown most clearly in  FIGS. 3 and 4 , the baffles  44 ,  46 , and  50  each include an oil flow opening  66 ,  68 ,  70 , respectively. As shown, these openings  66 ,  68 ,  70  are formed at the base of the respective baffle  44 ,  46 ,  50  closely adjacent the floor  34 . The openings  66 ,  68 ,  70  are sized to allow adequate oil flow between the respective chambers. For instance, in a high acceleration left turn, the oil in the oil pan  30  would be forced toward the side wall  40 . However, only a limited amount of oil would exit the oil pick-up chamber  56  through the opening  68 . Simultaneously, substantially the same amount of oil would enter the oil pick-up chamber  56  through the opening  66  so that the oil pick-up head  64  of the oil pick-up tube  62  remains submerged in oil. Therefore, the vehicle may maintain such a high acceleration turn for a relatively long period of time. Similarly, in a high G right turn, the oil would be forced toward the left side wall  36 , and in this instance, the same amount of oil exiting the oil pick-up chamber  56  through the opening  66  would enter the oil pick-up chamber  56  through the opening  68 , thereby assuring that the oil pick-up head  64  remains submerged. 
     In high G fore/aft acceleration situations (such as sudden turning, acceleration or braking events), the opening  70  in the baffle  50  maintains an adequate amount of oil flow between the oil pick-up chamber  56  and the rear chamber  60 . For example, during a high G braking situation, a limited amount of oil flows through the opening  70  from the rear chamber  60  into the oil pick-up chamber  56  to assure that the oil pick-up head  64  remains submerged. As shown most clearly in  FIG. 2 , the baffles  48 ,  52  are angled with respect to each other and with respect to the side walls  36 ,  40  to form a funnel shape to direct the oil toward the opening  70  and into the oil pick-up chamber  56  during such high G braking. Also, during a high G forward acceleration, the opening  70  only allows a limited amount of oil to exit the oil pick-up chamber  56  into the rear chamber  60 , thereby assuring that the oil pick-up head  64  remains submerged. 
     The openings  66 ,  68  are preferably the same size, and both are greater than the size of the opening  70 . However, these openings  66 ,  68 ,  70  would be appropriately sized to accommodate the configuration of the oil pick-up head  64 . 
     The openings  66 ,  68 ,  70  are sized for optimum performance for all driving conditions and oil viscosities. The openings permit sufficient flow with viscous oil, like that observed during −20° F. cold start, and with less viscous oil, like that observed during race track operation (310+° F.). 
     Accordingly, when the vehicle experiences high lateral and longitudinal accelerations, the oil flow control openings  66 ,  68 ,  70  act to limit the flow of oil away from the oil pick-up screen on the oil pick-up head  64 . The resultant performance of the vertical baffles and oil flow control openings is that the oil slosh is controlled and the oil pick-up screen remains submerged under all operating conditions, which allows the engine to operate at high vehicle accelerations for longer periods of time than current production vehicles. 
     The invention provides several benefits. The engine lubrication system performance is enhanced by the baffles and oil flow control openings. Oil drain back is increased, resulting in less oil starvation. Also, oil aeration and oil temperature is decreased. The bearings also receive more consistent oil pressure. Because oil is eliminated from the crankshaft windage, a gain of approximately two horsepower has been observed with the use of the present invention. The invention also results in significant weight and cost reductions. The one-piece casting reduces design complexity and material compared to other oil pan designs. The gasket and bolts required to complete the two-piece production design are eliminated and the engine is able to operate with one less quart of oil (about 1.82 pounds) than a comparable production design. The weight reduction associated with the use of this invention is estimated to be approximately four pounds (hardware plus one quart less of oil) per engine build. This weight reduction will also improve fuel economy. The cost reduction associated with the use of this invention is significant. By eliminating the horizontal baffle, there is no oil resting on top of such a baffle which may become entrained in the crankshaft windage, and increase engine friction. 
     While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.

Technology Category: f