Abstract:
An internal combustion engine ( 1 ), includes a cylinder head ( 2 ) and a cylinder block ( 3 ), with a crankcase ( 10 ) being fixed to the cylinder block ( 3 ), and with the crankcase ( 10 ) including at least one oil pump. In order to reduce the production effort the oil pump is arranged in the crankcase ( 10 ), with the oil pump ( 40 ) being connected with a flange ( 43 ), and with the flange ( 43 ) being fixed to a mounting wall ( 42 ) of the crankcase ( 10 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an internal combustion engine which includes a cylinder head and a cylinder block, with a crankcase being fixed to the cylinder block, and with the crankcase including at least one oil pump. 
     2. The Prior Art 
     It is known to arrange the cylinder head and the cylinder block as a unit. Such head-cylinder-block units are also known as monoblocs. An integral crankcase is usually adjacent to the head-block unit. Furthermore, internal combustion engines with multi-part crankcases are known, with one crankcase part and bearing bracket for the crankshaft bearing being cast together into one piece. This component is also known as “bed plate”. In the case of monobloc internal combustion engines, individual bearing blocks with individual bearing brackets were used up until now in order to enable the necessary accessibility for machining the cylinder bores. 
     An internal combustion engine with cylinder head and cylinder block is known from GB 2 425 570 B, with the cylinder head and the cylinder block being integrally arranged. 
     It is known from JP 2000-337117 A to fix an oil pump having an integrated control valve by means of screws from the outside to the crankcase. The mounting opening will simultaneously be sealed in an oil-tight manner by the flange of the intake line. It is disadvantageous that there is a relatively large number of areas that need to be machined. 
     It is the object of the invention to reduce the machining effort in an internal combustion engine of the kind mentioned above. 
     SUMMARY OF THE INVENTION 
     This is achieved in accordance with the invention in such a way that the oil pump is arranged in the crankcase, with the oil pump being connected with a flange, and with the flange being fixed to a mounting wall of the crankcase. 
     Simple fixing with little machining effort can be achieved when the flange is connected with the mounting wall by at least one first screw and the oil pump with the flange by at least one second screw, with preferably the second screws being longer than the first screws. 
     It is especially advantageous when the oil pump is arranged on an inside surface of the mounting wall, with preferably the flange being arranged on an outside surface of the mounting wall, with the first and second screws being insertable into respective screw boreholes from the flange side. The oil pump is fixed by the flange to the second part of the crankcase. Said flange is arranged in such a way that the first screws for the pump and the second screws for the flange are disposed on the same side, which is the outside of the crankcase. The flange is pressed with the short first screws against the clamping surface of the first part of the crankcase and the oil pump is pulled by the long second screws against the face surface of the flange. The advantage of this arrangement is that only a machining of the clamping surface and the centering bore for the flange is necessary from the outside in order to install the oil pump in the interior of the bottom part. 
     The machining effort can be reduced substantially especially in the case of internal combustion engines with an integral head-block unit formed by the cylinder head and the cylinder block. It is preferably provided further that the crankcase consists of a first part adjacent to the head-block unit and a second part adjacent to the first part, with the first and the second part being divided in a plane containing the axis of a crankshaft, preferably normal to the cylinder axes, with preferably the first and/or the second part forming at least one main bearing for the crankshaft. Preferably, the oil pump is arranged in the second part of the crankcase. An arrangement in the first part is also alternatively possible. 
     The invention will be explained below in greater detail by reference to the drawings: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an internal combustion engine in accordance with the invention in a sectional view along the line I-I in  FIG. 2 ; 
         FIG. 2  shows the internal combustion engine in a sectional view along the line II-II in  FIG. 1 ; 
         FIG. 3  shows the internal combustion engine in a sectional view along the line III-III in  FIG. 1 ; 
         FIG. 4  shows the internal combustion engine in a top view; 
         FIG. 5  shows the internal combustion engine in accordance with the invention in a sectional view along the line V-V in  FIG. 1 ; 
         FIG. 6  shows the internal combustion engine in a view along the line VI-VI in  FIG. 5 ; and 
         FIG. 7  shows the internal combustion engine in a further sectional view through the crankcase along the line VII-VII in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1 to 4  show an internal combustion engine  1  with a cylinder head  2  and a cylinder block  3 , with the cylinder head  2  and the cylinder block  3  being arranged in an integral fashion to form a head-block unit  4 . A crankcase  10  is adjacent to the head-block unit  4 , which crankcase consists of an upper first part  7  and a bottom second part  8 . The cylinder liners  9  are screwed into the head-block unit  4 . It is also possible alternatively to arrange the cylinder liners  9  integrally with the head-block unit  4 . 
     The head-block unit  4 , the first part  7  and the second part  8  of the crankcase  10  can consist of different materials. An especially light crankcase  10  can be realized when all components are made of light metal. It is alternatively also possible to make the head-block unit  4  and the first part  7  of light metal, and to make the cylinder liners  9  and the highly loaded second part  8  of gray cast iron. The distance between the individual cylinders arises from the condition that a complete mounting chamfer  13  needs to be arranged for the O-ring seal  11  of the cooling water chamber  12 . In the case of the integral cylinder liner, the cylinder distance will be smaller. The two-part crankcase  10  can accommodate at least one mass balancing shaft  20 , at least one injection-pump drive shaft and/or at least one oil pump  30 . 
     As is shown in  FIGS. 1 to 4 , the outlet lines  14  can be integrated in the head-block unit  4 . Furthermore, the inlet lines  15  and the inlet collector  16  can also be integrated partly in the head-block unit  4 . Especially in the case of a gasoline engine, long feed lines  17  (“ram pipes”) can be housed in the cylinder head cover  18  and the head-block unit  4 . The inlet collector  16  lies in this case at a lower position. 
     As is shown in  FIG. 1 ,  FIG. 5 , and  FIG. 6 , the mass balancing shaft  20  can be integrated in the first part  7 . The position of the mass balancing shaft  20  will be found in such a way that the balance weights  21  of the mass balancing shaft  20  are able to rotate with sufficient distance from the envelope  22  of the connecting rod (not shown in closer detail), wherein the axis  20   a  of the mass balancing shaft  20  does not necessarily have to lie in the plane ε of the axis  19   a  of the crankshaft  19 . In order to ensure that the machining of the bearing bores  23  can occur independent from the head-block unit  4 , the bearing bores  23  are housed in the flanged bushes  24 . They are fixed with flange screws  25  in the first part  7 . A first pin  26  which is arranged as an alignment pin is arranged on the straight connecting line  27  between the axis  19   a  of the crankshaft  19  and the axis  20   a  of the mass balancing shaft  20  at a precisely defined distance to the axis  19   a  of the crankshaft  19  in the region of the face sides  5  of the first part  7 . The first pin  26  is guided in a borehole  6  of the flanged bush  24  and keeps the necessary distance for the engagement of the two gearwheels  28 ,  29  for driving the mass balancing shaft  20  by the crankshaft  19 . 
     The machining of the area  30  for fixing the flanged bushes  24  in the first part  7  can occur from the outside. A respective recess  31  for accommodating the flanged bushes  24  is provided in the head-block unit  4 . 
     A second pin  32  with two flattened portions in its cross-section is further provided in the region of the face side  5  of the first part  7  in order to ensure parallelism of the mass balancing shaft  20  in relation to the crankshaft  19 . The two flattened portions  33  are aligned parallel to the connecting line  27  between the axis  19   a  of the crankshaft  19  and the axis  20   a  of the mass balancing shaft  20 . The flanged bush  24  comprises a guide opening  39  which corresponds with the second pin  32 . As a result, the flanged bush  24  can be pivoted about the first pin  26  without leading to any disadvantages for the tooth engagement of the two gearwheels  28 ,  29 . 
     In this way, the receiving bores  34  for the main bearings  35  of the crankshaft  19  and the bearing bores  23  in the flanged bushes  24  can be machined independent from the head-block unit  4  in one clamping. 
     The drive of the mass balancing shaft  20  can also occur with a chain instead of the gearwheels  28 ,  29 . 
     As is shown in  FIG. 5 , the mass balancing shaft  20  can also be arranged for driving an injection pump  36 . The mass balancing shaft  20  comprises a cam  37  for this purpose which acts upon the drive tappet  38  of the injection pump  36 . The position of the cam  37  can be chosen at will and can also be provided in the region of the bearing on the side of the flywheel as an alternative to the symmetrical arrangement as shown in  FIG. 5 . 
     Furthermore, an oil pump  40  can also be arranged in the crankcase  10 , i.e. either in the first part  7  or in the second part  8 . 
       FIG. 7  shows an embodiment in which the oil pump  40  is positioned in the second part  8 . The drive of the oil pump  40  occurs via the crankshaft  19  by the drive gearwheel  41 . For the purpose of fixing the oil pump  40 , a flange  43  is inserted into a mounting wall  42  of the second part  8 . The flange  43  is fixed by short first screws  44  to the mounting wall  42  of the second part  8 . Long second screws  45  pull the oil pump  40  against the face side  46  of the flange  43 . As a result, the oil pump  40  is not pressed by internal screws against the second part  8 , but is drawn by external second screws  45  against the face surface  46  of the flange  43 . 
     The screws  44 ,  45  for fixing the flange  43  and the oil pump  40  are arranged on the same externally accessible side of the crankcase  10 . 
     The advantage of this arrangement is that only one machining of the clamping surface  47  and the centering borehole  48  for the flange  43  is necessary from the outside in order to install the oil pump  40  in the interior of the crankcase  10 . 
     The drive of the oil pump  40  can also occur via a chain (not shown in greater detail) as an alternative to the drive via the drive gearwheel  41 .