Abstract:
An engine is provided with a cylinder block and a ladderframe having a portion of an oil conduit and a deflector. The engine has a metal-to-metal seal positioned between the ladderframe and block to circumferentially surround the oil conduit, and has a gasket seal positioned between the ladderframe and block to be outboard and spaced apart from the oil conduit. The deflector is positioned between the metal-to-metal seal and the gasket seal. An engine component is provided with a member having a deflector and forming an oil conduit. The deflector has an arcuate deflector surface following an outer wall of the oil conduit to redirect oil escaping the oil conduit. A ladderframe is configured to provide a deflection surface, with the deflection surface positioned to guide high pressure oil away from adjacent RTV seals.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to GB 1609835.2 filed Jun. 6, 2016, which is hereby incorporated by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    This invention relates to improvements in or relating to the use of features intended to control the flow of a lubricant, also referred to as oil, within a vehicle engine, and in particular to the deflection of flow of oil. 
       BACKGROUND 
       [0003]    Metal-to-metal seals are deployed in various locations within automotive systems, typically for internal seals in parts of the system where there is some tolerance of imperfection, that is, where the seal may still perform its required function despite being less than 100% effective. 
         [0004]    For example, the oil connections in the low end of an engine which are internal to the engine may still function effectively where seals are less than perfect, because oil escaping through these seals will drain back to the oil sump. The oil can safely drain back to the oil sump without exiting the engine. Therefore there is no detrimental effect on the perceived quality of the engine which will continue to run, but the fuel consumption of the engine will increase and the pumping requirements will also increase. It therefore remains the aim to improve or maximize the efficiency of sealing throughout the engine. 
         [0005]    When a metal-to-metal seal starts to leak, it can result in a jet of oil spraying from the leak point. If the conduit containing the seal is a high pressure conduit, then the oil may be at high pressure or pressurized. This oil can cause damage to adjacent seals, particularly those formed from room temperature vulcanizing (RTV) silicone rubber. 
         [0006]    It is against this background that the present invention has arisen. 
       SUMMARY 
       [0007]    According to embodiments of the present invention there is provided a ladderframe or engine component configured to provide a deflection surface positioned to guide high pressure oil away from adjacent RTV seals. If high pressure oil is incident directly on RTV seals, the oil may cause the seal to fail over time. The deflection surface is configured to divert the high pressure oil to prevent it from landing directly on the RTV seal. In this way the integrity of the RTV seal is preserved and with it the efficiency of the engine and the user&#39;s perception of the quality of the engine. 
         [0008]    In an embodiment, an engine is provided with a cylinder block defining a portion of an oil conduit intersecting a lower surface of the block, and a ladderframe having an upper surface intersecting another portion of the oil conduit and a deflector adjacent to the another portion of the oil conduit. The engine has a metal-to-metal seal positioned between the upper surface of the ladderframe and the lower surface of the block to circumferentially surround the oil conduit, and a gasket seal positioned between the upper and lower surfaces to be outboard and spaced apart from the oil conduit. The deflector is positioned between the metal-to-metal seal and the gasket seal. 
         [0009]    In another embodiment, an engine component is provided with a member having a deflector and forming an oil conduit intersecting an upper surface. The oil conduit has an inner wall and an outer wall extending transversely to the upper surface. The deflector has an arcuate deflector surface following the outer wall of the oil conduit and positioned adjacent to and radially outboard thereof to redirect oil escaping the oil conduit and flowing towards an adjacent room temperature vulcanizing seal. 
         [0010]    The invention will now be further and more particularly described, by way of example only, and with reference to the accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  shows a cross section through a prior art ladderframe and highlights the area of concern; 
           [0012]      FIG. 2  shows a cross section through a ladderframe according to the present invention; 
           [0013]      FIG. 3  shows a perspective view of a deflection surface; and 
           [0014]      FIG. 4  shows how the deflection surface would operate in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    As required, detailed embodiments of the present disclosure are provided herein; however, it is to be understood that the disclosed embodiments are merely exemplary and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure. 
         [0016]      FIG. 1  shows a ladderframe  100  and cylinder block  110  of an engine where the ladderframe is positioned between the cylinder block on an oil sump (not shown). The ladderframe  100  may support main bearings and an engine crankshaft. Each of the ladderframe  100  and the cylinder block  110  define portions of a high pressure oil conduit  101  that are in direct fluid connection when the ladderframe  100  is connected to the cylinder block  110 . There are two seals between the ladderframe  100  and the cylinder block  110 : a metal-to-metal seal  102  is provided midway along a high pressure oil conduit  101  adjacent to the inner engine  106  and a gasket seal  104  is provided at the interface further from the inner engine  106 , for example, along an outer edge region of the ladderframe and cylinder block. A lower surface of the cylinder block  110  cooperates with an upper surface of the ladderframe  100  and the seals  102 ,  104  when the engine is assembled. 
         [0017]    A metal-to-metal seal  102  is chosen for the inner seal because if the seal fails then oil escaping from the conduit  101  between the ladderframe  100  and the cylinder block  110  will drain back into the oil sump. Whilst this will have some negative impact in terms of efficiency of the engine, failure of this seal cannot directly result in the oil exiting the engine and thereby damaging the users&#39; perception of the engine overall. As a metal-to-metal seal is more economical to implement due to the lack of additional parts or additional sealant application being required during assembly and as it has limited negative impact in the case of failure, it is preferred for this location. 
         [0018]    A gasket seal  104  is provided at the interface further from the inner engine  106 . A gasket seal includes an additional part, typically in the form of a room temperature vulcanizing (RTV) gasket or O-ring which ensures that no oil leaks. This is particularly important at this location because oil leaking from this seal  104  would not naturally drain back to the oil sump and could exit the engine, adversely affecting the users&#39; perception of the engine. 
         [0019]      FIG. 1  shows the path taken by oil  120  in the situation where the metal-to-metal seal  102  has failed with a conventional ladderframe and oil is leaking from the conduit  101 . The oil  120  is incident on the gasket seal  104 . The oil  120  is at high pressure and could compromise the integrity of the gasket seal  104 . This therefore creates an area of concern  130 . If the high pressure oil or pressurized oil  120  did damage the gasket seal  104  then oil could seep from the engine in the direction marked by arrow A. 
         [0020]      FIG. 2  shows the same cross section through a ladderframe  10  and cylinder block  11  as  FIG. 1 , but the ladderframe  10  shown in  FIG. 2  is provided with a deflection surface  14  or deflector surface  14  according to the present disclosure. The deflector  15  is integral with the ladderframe  10 . The ladderframe  10  is a cast part and the deflector  15  is produced as part of or during the casting process. 
         [0021]    The deflector  15  includes a support  16  and a deflection surface  14 . The deflector  15  disrupts the oil  120  spraying from the metal-to-metal seal  102  and diverts it back towards the oil sump (not shown) beneath the ladderframe  10 , and opposed to the cylinder block  11 . As will be readily apparent from  FIG. 2 , the gasket seal  104  is no longer in the path of oil  120  spraying from the metal-to-metal seal  102 . 
         [0022]      FIG. 3  shows a part perspective view of the ladderframe  10  clearly showing the deflector  15 . The deflector  15  has an elongate support  16  and a deflection surface  14 . The deflection surface  14  is arcuate. The deflection surface  14  conforms closely to, but does not touch, the metal-to-metal seal  102  in the high pressure oil conduit  101  leading from the ladderframe  10  into the cylinder block  11 . The deflection surface  14  arc is a circular arc with a radius slightly larger than the radius of the conduit  101 , or slightly larger than a radius of the outer surface or outer wall of the conduit  101 . As shown, the inner edge  17  of the deflection surface  14  is spaced apart from the outer edge or surface of the high pressure oil conduit  101 , and has a radius that is larger than the adjacent radius of the conduit  101 . The support  16  extends away from the deflection surface  14 , initially substantially orthogonally and then curves away to interface with the surface of the ladderframe  10 . The exact configuration of the support  16  is not critical to the functioning of the deflector  15 , the support  16  will be shaped in any way practical to provide the deflection surface  14  in a position to divert the high pressure oil spray away from the gasket seal  104 . 
         [0023]    The top part of the deflection surface  14  can be machined if required as a result of process constraints. In the illustrated embodiment, the top of the deflector  15  is machined at the same time as the joint surface of the ladderframe  10  or surface that cooperates with the block  11  and seal  102 , such that the defector top is co-planar with the surface of the ladderframe. This is due to the proximity between the conduit  101  and the deflector  15  and the size of the cutter. However, in some embodiments, the top surface could be machined separately if it was far enough from the conduit  101 . In such a configuration the deflector  15  would be higher than the metal-to-metal seal  102 , or offset above the ladderframe surface, thereby optimizing protection of the RTV seal  104 . 
         [0024]    The deflection surface  14  illustrated in  FIG. 3  has a substantially constant cross sectional area or substantially constant width along the length of the deflector, tapering slightly at the ends or end regions. This delivers the required deflection of the oil, with a minimal addition to the overall weight of the ladderframe  10 . However, it would also be understood that the thickness of the deflection surface  14  could vary whilst still allowing the deflection surface  14  to function as required. 
         [0025]    The deflection surface  14  illustrated in  FIG. 3  has an arcuate shape with a substantially constant angle of curvature. However, in other embodiments not illustrated in the accompanying drawings, the curvature may be non-uniform or even non-existent. The curvature may be modified in order to guide the oil incident on the deflection surface  14  back to the oil sump (not shown). 
         [0026]      FIG. 4  shows an end view of the conduit  101  with the deflector  15  and deflection surface  14  diverting incident oil  120  to protect the gasket seal  104 . 
         [0027]    According to embodiments of the present invention there is provided a ladderframe configured to provide a deflection surface positioned to guide high pressure oil away from adjacent RTV seals. If high pressure oil is incident directly on RTV seals, the oil may cause the seal to fail over time. The deflection surface is configured to divert the high pressure oil to prevent it from landing directly on the RTV seal. In this way the integrity of the RTV seal is preserved and with it the efficiency of the engine and the user&#39;s perception of the quality of the engine. 
         [0028]    The deflection surface may be integral with the ladderframe so that the provision of the deflection surface does not entail any additional manufacturing steps or components. 
         [0029]    The ladderframe, including the deflection surface, may be provided as a cast part. Casting can achieve the complex geometries required to provide the ladderframe with the deflection surface in a single manufacture step. 
         [0030]    The deflection surface may be arcuate. An arcuate deflection surface will guide oil incident thereon to flow safely back to the oil sump without being incident on the RTV seals. 
         [0031]    At least part of the deflection surface, in particular the top part of the deflection surface can be machined if required by the process. 
         [0032]    It will further be appreciated by those skilled in the art that although the invention has been described by way of example with reference to several embodiments it is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined in the appended claims. While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure.