Abstract:
An improved internal combustion engine lubricating system that includes an oil filter that is mounted on a mounting bracket that is fixed to a side face of an engine component that has direct communication with the oil pump and the engine main oil gallery to minimize the number of passages that must be sealed to prevent leakage and to make a more compact assembly.

Description:
BACKGROUND OF INVENTION 
   This invention relates to an internal combustion engine and more particularly to the lubricating system for such engines. 
   As is well known, internal combustion engines require a lubricating system for providing lubricant to their moving components. In addition to the lubricating function, the lubricant also generally serves the function of cooling the engine, at least partially. With at least four cycle engines, the lubricating system includes a lubricant reservoir that stores the lubricant, an oil pump, that pressurizes the stored lubricant and circulates it through suitable passages to the lubricated areas and a return to the reservoir. Normally an oil filter is provided through which the circulated oil is passed to entrap foreign articles and prevent them from reaching the lubricated surfaces. Often the oil filter is associated with a heat exchanger to aid the cooling operation. 
   Thus the lubricating system requires a number of components, a drive for the pump or pumps, a filter arrangement and the formation and provision of the requisite passages for the lubricant flow, return and passage through the filter. Since the filter normally involves a cartridge that requires servicing, access and ease of servicing is important. 
   Japanese published application Hei 6-299863 shows a typical type of prior art approach to this problem. As seen therein, the engine has a cylinder block in which cylinder bores are formed. A bulkhead formed separately from the cylinder block and secured to its lower face acts with the cylinder block to support a crankshaft. A separate oil pan is secured to the lower face of the bulkhead and an oil pump driven by the crankshaft is supported on the bulkhead and depends into the oil pan. In addition to this construction conventionally the engine is provided with a bracket protruding from the engine body for removably securing an oil filter. The oil filter communicates with the engine through oil passages formed in the cylinder block, the bulkhead, and the bracket. Thus resulting in a complicated arrangement having a number of connecting joints that require effective sealing. 
   Another example of this complicated arrangement is shown in U.S. Pat. No. 5,647,315. That arrangement also adds an oil cooler to the oil filter body further complicating the plumbing of the oil and coolant passages. Also the mounting arrangement for the filter element is somewhat complicated and bulky. 
   It is therefore a principal object of the invention, to provide an effective oil filter mounting and connecting arrangement that reduces the number of connecting joints and permits more latitude in the filter mounting. In addition another object is to simplify and make the oil filter mounting more compact without adversely affecting serviceability. 
   SUMMARY OF INVENTION 
   This invention is adapted to be embodied in an internal combustion engine and lubricating system therefore. The engine is comprised of an engine body consisting of a cylinder block having at least one cylinder bore formed therein with a cylinder head assembly affixed to an end of the cylinder block in closing relation to the cylinder bore. A piston reciprocates in the cylinder bore and drives a crankshaft. A crankcase assembly is fixed to another end of the cylinder block assembly and cooperates with the cylinder block to journal the crankshaft. The crankcase assembly including an oil pan member for collecting lubricant from the engine. An oil pump is driven by the crankshaft and depends at least in part into the oil pan. A mounting pad is formed on a side surface of a single component of the engine. An oil delivery passage formed in the single component communicates with the oil pump and terminating at an oil delivery port opening through the side surface and within the mounting pad. An oil discharge passage for delivering filtered oil to the engine is also formed in the single component and begins at an oil discharge port opening through the side surface and within the mounting pad. The assembly is completed by an oil filter attaching bracket affixed to the mounting pad and adapted to detachably mount an oil filter. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a front elevational view of an internal combustion engine and accessory drive constructed in accordance with an embodiment of the invention. 
       FIG. 2  is an enlarged front elevational view of the engine looking in the same direction as  FIG. 1 , but with the timing cover of the engine removed. 
       FIG. 3  is a side elevational view of the engine. 
       FIG. 4  is an enlarged cross sectional taken along the line  4 — 4  in  FIG. 2 . 
       FIG. 5  is a side elevational view looking in the same direction as  FIG. 3 , showing only the assembled cylinder block and crankcase assembly in solid lines and some of the engine accessories in phantom. 
       FIG. 6  is an enlarged view looking in the same direction as  FIG. 1 , of the oil filter and mounting arrangement therefore with portions broken away and shown in section. 
   

   DETAILED DESCRIPTION 
   Referring now in detail to the drawings and initially primarily to  FIGS. 1–3 , a multi-cylinder, four-stroke internal combustion engine embodying the invention is indicated generally by the reference numeral  11 . In the illustrated embodiment the engine  11  is shown as having four in line cylinders. Of course, from the following description it will be obvious to those skilled in the art, that the invention can be utilized with engines having other numbers of cylinders and other engine configurations. In addition the invention is not limited to engines operating on the four stroke principle. 
   The engine  11  is adapted to be mounted on and power a vehicle such as an automobile and is depicted as being mounted vertically therein, although the invention is not so limited. The engine  11  has an engine body, indicated generally at  12  supported in a suitable fashion by a vehicle body (not shown), engine body  12  is comprised of a cylinder block, indicated generally at  13 . The cylinder block  13  is formed with four cylinder bores  14  ( FIG. 2 ) having parallel axes  15 . Detachably affixed, in a known manner, to the lower end of the cylinder block  13  is a bulkhead, indicated generally at  16 , to form the upper portion of a crankcase assembly. 
   A cylinder head assembly  17  is secured to the upper face of the cylinder block  13  in a known manner and closed the upper ends of the cylinder bores  14 . The cylinder head assembly  17  supports valves for controlling the admission of a charge into the engine combustion chambers and the discharge of exhaust gasses therefrom in any suitable manner and as is well known in this art. These valves are operated in a manner to be described. This valve and operating mechanism is enclosed by a cylinder head cover  18  that is secured to the upper face of the cylinder head  17 . 
   The aforedescribed crankcase assembly, the upper portion of which is formed by the lower part of the cylinder block  13  and bulkhead  16  is completed and closed by an oil pan, indicated generally at  19 , that is suitably secured to the lower face of the bulkhead  16  and contains lubricating oil. 
   The engine  11  is provided with pistons  21  reciprocating in the cylinder bores  14  and connected by connecting rods  22  to drive a crankshaft  23 . The crankshaft  23  rotates about an axis  24  that extends generally horizontally. The crankshaft  23  is journalled about this axis  24  by bearings carried by the cylinder block  13  and bulkhead  16  in a manner well known in the art. 
   The aforementioned intake and exhaust valves are operated in a suitable manner by a valve actuating mechanism, indicated generally at  25 . This valve actuating mechanism  25  is comprised of an intake camshaft  26  and an exhaust camshaft  27  in suitable operational engagement with the intake valves and exhaust valves, (not shown) respectively. The camshafts  26  and  27  haves axes that extend parallel to the axis  24  of the crankshaft  23 . A timing chain  28  interconnects a sprocket provided on one end of the crankshaft  23  with sprockets on the ends of the camshafts  26  and  27  to drive them in timed relation at one half the rotational speed thereof. 
   As has been noted, the cylinder block  13  is made by casting, and preferably of low pressure cast aluminum with the cylinder head  17  formed of the same material and fixed to the upper face thereof in a known manner. The aforedescribed crankcase assembly and specifically an upper flange  29  of the bulkhead  16  is affixed thereto in any suitable manner. Oil pan  19  has a generally dish-shaped oil pan body  31  opening upward and an outward flange  32  formed integrally with the upper outer edge of the oil pan body  31  that is sealingly engaged with the lower face of the bulkhead  16  to add to the rigidity of the structure. 
   The engine  11  is provided with a number of accessories disposed in the outer lateral vicinity of the engine body  12 . Some of these accessories are for engine operation while others are for vehicle or other purposes. These include an air compressor  33  for vehicle air conditioning, an engine coolant pump  34  for delivering coolant to a coolant jacket formed in the engine body  12  to cool the engine body  12 , an alternator  35  for generating electrical power for the vehicle and engine ignition, and a power steering pump  36  for power assist of the vehicle steering. Each of these accessories  33 ,  34 ,  35  and  36  are driven in a well known manner from a pulley  37  that is affixed to the crankshaft  23  by means of a serpentine belt  38 . 
   As has been noted, the engine driven accessories include the coolant pump  34 . This pump  34  has an outer housing that is integral with the cylinder block  13  and thus reinforces it. This outer housing includes a discharge duct portion  39  that communicates with cooling jackets  41  ( FIG. 2 ) formed in the cylinder block  13  around the cylinder bores  14 . These cooling jackets  41  also cooperate with cooling jackets (not shown) formed in the cylinder head  17 . The coolant also passes through a heat exchanger (not shown) in a manner well known in the art. 
   In addition to the cooling system just described and in accordance with the invention, the engine  11  is provided with a lubricating system that includes the crankcase assembly and specifically the oil pan  19 . The lubricant is supplied by this system to portions of the engine  11  to be lubricated such as bearings for the crankshaft  23  and the camshafts  26 ,  27 . The lubricating system is provided with an oil pump  42  supported directly on the bulkhead  16  so that it protrudes downward from the lower face of the bulkhead  16  to be disposed in the oil pan  19 . 
   The oil pump  42  may be of any known type and has a drive shaft  43  to which a sprocket  44  affixed to an end thereof that extends outwardly in the oil pan  19 . The sprocket  44  is driven by a driving chain  45  that is driven in turn by a sprocket  46  fixed to one end of the crankshaft  23 . This drive will now be described in more detail by primary reference to  FIG. 4 . There is provided a tensioner mechanism, indicated generally by the reference numeral  47 , for maintaining the desired tension in the oil pump driving chain  45 . The tensioner  47  is includes a tension arm  48 , one end of which is pivoted on the bulkhead  16  by a pivot shaft  49 , so that the other end can be rotated about an axis  51  defined by the pivot shaft  49 . The other end of the arm  48  is urged into contact with the chain  45  by a spring  52  to maintain the desired tension. 
   The oil pump  42  supplies its pumped lubricant to the lubricated components of the engine  11  through a feed system that includes a removable oil filter of the cartridge type, indicated generally by the reference numeral  53 . This is mounted on the engine  11  and particularly on the bulkhead  16  by a mounting bracket, indicated generally at  54  as shown best in  FIG. 6 . This mounting bracket  54  is affixed, in a manner to be described shortly, on a mounting pad  55  formed integrally on a side face of the bulkhead  16 . 
   In addition to carrying the oil filter  53 , the mounting bracket  54  carries an oil cooler, indicated generally by the reference numeral  56 . This oil cooler  56  is interposed, in a manner to be described shortly, between the mounting bracket  54  and the oil filter  53 . Referring now additionally to  FIG. 5 , it will be seen that the mounting pad  55  is formed as an outward projection of the side face of the bulkhead  16  and defines an inlet cavity  57  and a discharge cavity  58  that are separated by an angularly disposed dividing wall  59 . 
   Continuing to refer primarily to  FIGS. 5 and 6 , it will be seen that the oil pump  42  discharges the pumped oil in a vertical direction to enter a vertically extending passage  61  that extends in the bulkhead  16  from its lower face. This vertical passage  61  intersects a horizontal passage  62  that terminates in the inlet cavity  57  of the mounting pad  55  via an opening  63 . 
   After passing through the oil cooler  56  and the filter  53 , in a manner to be described shortly, the cooled and filtered lubricant is delivered to the discharge cavity  57  for delivery to the lubricated components of the engine  11  through an opening  64  of the main oil gallery of the engine  11  that is formed initially in the bulkhead  16 . The opening  64  communicates with the initial part of the main oil gallery, indicated by the reference numeral  65 , that is formed in the bulkhead  16  as seen in  FIG. 6 . From there the oil passes to the aforenoted lubricated components of the engine through suitable passages, as is well known in the art. 
   Continuing to refer primarily to  FIG. 6 , it will be seen that the mounting bracket  54  which is formed separately from the bulkhead  16  has a pair of side flanges  66  that have openings for receiving fasteners  67  for removable attachment to the mounting pad  55  formed on the outer lateral face of the bulkhead  16 . 
   The oil cooler  56  has an outer housing  68  of a generally ring shape with a generally flat upper surface  69  that is held in sealing relation with a mating lower surface of the mounting bracket  54  by means of a shoulder  71  of a fastener, indicated generally by the reference numeral  72 . The fastener  72  has a threaded portion  73  that is received in a tapped opening of the mounting bracket  54  to load a sealing gasket  74  between the mating face  69  of the oil cooler  56  and the mounting bracket  54 . 
   Positioned within the oil cooler body  69  is a heat exchanger  75  that receives engine coolant from the engine cooling jacket  41  via a conduit  76  and fitting  77  ( FIG. 3 ). After this coolant passes through the heat exchanger  75  it is returned to the cooling jacket  41  via a return fitting  78  and return conduit  79 . 
   Referring again to  FIG. 6 , the oil filter  53 , as has already been noted, is of the canister type and includes a can shaped outer housing  81  in which a filter media of any desired type  82  is received. This outer housing is formed with an end wall  83  having a tapped opening  84  that is threaded onto a lower threaded portion  85  of the fastener  72 . A sealing ring  86  is thus sealingly compressed between the end wall  83  and the lower face of the heat exchanger body  68 . 
   The cylinder block oil passage  62  mates with an oil delivery passage  87  formed in the mounting bracket  54  that terminates in a plurality of downwardly opening passages to communicate with the upper wall of the oil cooler  56  in the area inwardly of the sealing gasket  74 . The oil cooler outer housing has a plurality of openings  88  in this area to permit oil to enter into the oil cooler  56  for cooling in the direction indicated by the arrows. 
   In a like manner the lower wall of the oil cooler housing  68  has a plurality of discharge openings to permit the oil to enter the area of the oil filter end wall  83  inwardly of the sealing ring  86  again as shown by the flow indicating arrows. The oil then enters the oil filter  53  to flow through the filter media  82  through openings in the end wall  83  as also shown by the flow indicating arrows. 
   The thus cooled and filtered oil then exits the filter  53  and cooler  56  through an internal passage  89  formed in the fastener  72 . The oil then flows into a delivery passage  91  formed in the mounting bracket  54 , as again shown by the flow arrows. The delivery passage  91  in turn communicates with the initial part  65  of the engine main oil gallery formed in the bulkhead  16  to deliver the cooled and filtered oil to the engine  11 . After the lubrication, the lubricating oil is returned to the oil pan  19  in any known manner for repeated delivery by the oil pump  42 . 
   In the above case, the oil filter  53  and the oil cooler  56  are both located on an axis defined by the fastener  72 . The lubricating oil flows in an axial direction evenly through the oil filter  53  and the oil cooler  56 , and returns through the passage  89  in the fastener  72 . Thus, the filtration of the lubricating oil by the oil filter  53  and the cooling by the oil cooler  56  can be achieved effectively. 
   Since all of the oil delivery passages and return passages between the oil pump  42 , the oil cooler  56 , oil filter  53  and the engine lubricating main gallery  65  are formed in a single engine body piece, in this case the bulkhead  16 , the number and location of sealing surfaces required by the prior art constructions is substantially reduced with not only cost savings but good insurance against leakage. Also, since the bracket  54  is a separate body from the bulkhead  16 , it is possible to select a variety of postures and positions of the oil filter  53  and the oil cooler  56 , which are secured to the bracket  54 , by selecting a variety of shapes of the bracket  54 . Therefore, adoption of suitable postures and positions of the oil filter  53  and the oil cooler  56  permits arranging the engine body  12 , the oil filter  53 , and the oil cooler  56  in a compact manner, thereby preventing the lubricating system from being oversized. 
   Of course those skilled in the art will readily understand that the described embodiment is only exemplary of forms that the invention may take and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. For examples only, the engine  11  may be a two-stroke engine and/or the axes  15  of the cylinder bores  14  may be inclined with respect to the vertical.