Abstract:
An engine configuration includes an internal combustion engine with a plurality of cylinders, at least one turbocharger and a first and a second exhaust gas tract. A turbine of the at least one turbocharger is associated with the first exhaust gas tract. Increased torque and increased power can be achieved when a bypass exhaust gas line emerging from at least one cylinder, which is associated with the first exhaust gas tract, is connected to the first exhaust gas tract such that it bypasses the at least one turbocharger.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation, under 35 U.S.C. § 120, of copending International Application No. PCT/EP2005/006765, filed Jun. 23, 2005, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German Patent Application No. DE 10 2004 034 314.4, filed Jul. 15, 2004; the prior applications are herewith incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION  
     Field of the Invention  
       [0002]     The invention relates to an engine configuration including an internal combustion engine with a plurality of cylinders and at least one turbocharger.  
         [0003]     European Patent Publication No. EP 0 716 221 B1 discloses a configuration of an internal combustion engine having two cylinder banks with two exhaust gas tracts which are connected via an exhaust gas collecting pipe. The connection can be established and interrupted depending on load conditions. A turbocharger is provided in one of the exhaust gas tracts.  
       SUMMARY OF THE INVENTION  
       [0004]     It is an object of the invention to provide an engine configuration including an internal combustion engine with increased torque and power.  
         [0005]     With the foregoing and other objects in view there is provided, in accordance with the invention, an engine configuration, including:  
         [0006]     a first exhaust gas tract;  
         [0007]     a second exhaust gas tract;  
         [0008]     an internal combustion engine having a plurality of cylinders, at least one of the cylinders being assigned to the first exhaust gas tract;  
         [0009]     the internal combustion engine having a turbocharger with a turbine assigned to the first exhaust gas tract; and  
         [0010]     a bypass exhaust gas line connected to the first exhaust gas tract, the bypass exhaust gas line starting at least one of the cylinders assigned to the first exhaust gas tract and bypassing the turbocharger.  
         [0011]     In other words, according to the invention, there is provided a configuration with an internal combustion engine with a several cylinders and at least one turbocharger as well as a first and a second exhaust gas tract, wherein a turbine of the at least one turbocharger is assigned to the first exhaust gas tract, wherein a bypass exhaust gas line emerging from at least one cylinder, which is associated with the first exhaust gas tract, is connected to the first exhaust gas tract such that it bypasses the at least one turbocharger. The exhaust gas turbine of the turbocharger is charged by fewer than all cylinders of the internal combustion engine, preferably by half of the cylinders. The internal combustion engine is preferably a spark ignition engine. The power of the internal combustion engine can be increased by charging the internal combustion engine. In order to reduce fuel consumption, the system can advantageously be combined with a cylinder deactivation. The response time of the turbocharger or turbochargers can be reduced by a specific configuration of the turbocharger or turbochargers.  
         [0012]     According to another feature of the invention there is provided a first cylinder bank and a second cylinder bank; and the cylinders of the internal combustion engine are disposed in a respective one of the first cylinder bank and the second cylinder bank. By providing the cylinders assigned to the first exhaust gas tract in the first cylinder bank and the cylinders assigned to the second exhaust gas tract in the second cylinder bank, the control of the possibly deactivatable cylinders is made easier in case of high or low power demand on the internal combustion engine. It is advantageous if the compressor of the at least one turbocharger provides all cylinders of both cylinder banks with the corresponding air-mass flow for the respective requested torque. A single throttle device, via which the total air-mass flow needed by the internal combustion engine is taken in, is then advantageously sufficient. Cylinders which do not supply exhaust gas to the turbine can be deactivated, i.e. shut off, through the use of a cylinder deactivation or their throughput can at least be reduced in case of low loads and/or low engine speeds. The compression conditions are preferably individually adjusted for the cylinders, for example such that the deactivatable cylinders have a higher compression and the other cylinders have a lower compression.  
         [0013]     In accordance with an advantageous embodiment, a second turbocharger is provided in the bypass exhaust gas line. In accordance with an advantageous development, the second turbocharger is dimensioned to be different from the first turbocharger. This allows an advantageous tuning for different power and engine speed ranges of the internal combustion engine.  
         [0014]     In accordance with an advantageous embodiment, a separate turbocharger is assigned to each cylinder bank wherein a bypass exhaust gas line, which starts at at least one cylinder assigned to the second exhaust gas tract, is connected to the second exhaust gas tract such that it bypasses the second turbocharger. The air intake side can be shared by both cylinder banks. Alternatively, an air intake side of the internal combustion engine as well an exhaust gas system can advantageously be separated at least as a dual flow configuration along their entire running length, such that the two cylinder banks have their respective separate air supply. When there is a correspondingly low load request, a part of the cylinders can be shut off i.e. deactivated such that either at least a part of the cylinders or up to all cylinders of a cylinder bank are shut off or, alternatively, respectively some of the cylinders of the two cylinder banks, preferably an equal number of cylinders of the two cylinder banks, are shut off. Accordingly the two turbochargers are charged with exhaust gas by fewer than all cylinders of a cylinder bank. The exhaust gas of the remaining cylinders can be fed into the respective exhaust gas tract while the respective turbine of the respective turbocharger is bypassed. The internal combustion engine is preferably a spark ignition engine with direct fuel injection.  
         [0015]     According to another feature of the invention, the cylinders are assigned to a respective one of the first exhaust gas tract and the second exhaust gas tract, the cylinders assigned to the first exhaust gas tract are disposed in the first cylinder bank and the cylinders assigned to the second exhaust gas tract are disposed in the second cylinder bank.  
         [0016]     According to another feature of the invention, the internal combustion engine has a further turbocharger, the further turbocharger is provided in the bypass exhaust gas line connected to the first exhaust gas tract. According to another feature of the invention, the further turbocharger is dimensioned to be different from the turbocharger.  
         [0017]     According to another feature of the invention, the internal combustion engine has a further turbocharger, the turbocharger is assigned to the first cylinder bank, and the further turbocharger is assigned to the second cylinder bank.  
         [0018]     According to another feature of the invention there is provided a further bypass exhaust gas line connected to the second exhaust gas tract, the further bypass exhaust gas line starts at least one of the cylinders assigned to the second exhaust gas tract and bypasses the further turbocharger.  
         [0019]     According to another feature of the invention, the first cylinder bank and the second cylinder bank each have a respective separate air supply.  
         [0020]     According to an alternative feature of the invention, the first cylinder bank and the second cylinder bank have a common air supply.  
         [0021]     According to another feature of the invention, the first exhaust gas tract and the second exhaust gas tract have respective running lengths and are separated from one another along the running lengths such that the first exhaust gas tract and the second exhaust gas tract form at least a dual-flow configuration along the running lengths.  
         [0022]     According to another feature of the invention, given ones of the cylinders, whose exhaust gas can be fed into the first exhaust gas tract by passing the turbine of the turbocharger, are configured such that their throughput can be reduced or completely deactivated.  
         [0023]     According to another feature of the invention, the further turbocharger, which is provided in the bypass exhaust gas line, has a turbine; and given ones of the cylinders, whose exhaust gas can be fed into the first exhaust gas tract by passing the turbine of the turbocharger or the turbine of the further turbocharger, are configured such that a throughput of the given ones of the cylinders can be reduced or completely deactivated.  
         [0024]     According to another feature of the invention, the further turbocharger, which is assigned to the second cylinder bank, has a turbine; and given ones of the cylinders, whose exhaust gas can be fed into the first exhaust gas tract or the second exhaust gas tract by passing the turbine of the turbocharger or the turbine of the further turbocharger, are configured such that a throughput of the given ones of the cylinders can be reduced or completely deactivated.  
         [0025]     According to another feature of the invention, the given ones of the cylinders, which are configured to be deactivatable with respect to their throughput, have a compression greater than a compression of non-deactivatable ones of the cylinders of the internal combustion engine.  
         [0026]     According to another feature of the invention, the internal combustion engine is a direct-injection spark-ignition engine.  
         [0027]     Other features which are considered as characteristic for the invention are set forth in the appended claims.  
         [0028]     Although the invention is illustrated and described herein as embodied in a engine configuration including an internal combustion engine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.  
         [0029]     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]      FIG. 1  is a schematic view of an engine configuration including an internal combustion engine with twelve cylinders and a turbocharger that can be supplied with exhaust gas by an exhaust gas tract in accordance with the invention;  
         [0031]      FIG. 2  is a schematic view of an engine configuration including an internal combustion engine with twelve cylinders and a respective turbocharger in each exhaust gas tract, the turbochargers being dimensioned to be equal in accordance with the invention;  
         [0032]      FIG. 3  is a schematic view of an engine configuration including an internal combustion engine with twelve cylinders and a respective turbocharger in each exhaust gas tract, the turbochargers being dimensioned different from one another in accordance with the invention; and  
         [0033]      FIG. 4  is a schematic view of an engine configuration including an internal combustion engine with two turbochargers each being charged only by a part of all the cylinders in accordance with the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]     Referring now to the figures of the drawings in detail and first, particularly, to  FIG. 1  thereof, there is shown a first preferred embodiment of an engine configuration according to the invention. An internal combustion engine  10  that is embodied as a twelve-cylinder spark ignition engine has two separate cylinder banks  11  and  12  with a number of cylinders  13  and  14  and, respectively,  15 . Those cylinders, which form a group with respect to their function, are respectively denoted by the same reference numeral. A first exhaust gas tract  1  and a second exhaust gas tract  2  extend separated from one another in a dual-flow configuration along their entire running length. A turbocharger  20  is provided in the first exhaust gas tract  1  and is placed, with its compressor  22 , in an intake line  17 . The compressor  22  supplies the air plenum  18 , which is shared by both cylinder banks  11 ,  12 , with an air-mass flow via the intake line  17 .  
         [0035]     Exhaust gas lines of the cylinders  15  of the second cylinder bank  12  lead into an exhaust gas collecting line  40  of the second exhaust gas tract  2  in which a first catalytic converter  41 , in particular a precatalytic converter, and a second catalytic converter  42 , in particular a main catalytic converter, and a muffler  43  are provided. The cylinders  15  are configured such that they can be deactivated, i.e. shut off, or at least their throughput be reduced.  
         [0036]     In the first exhaust gas tract  1 , a turbine  21  of the turbocharger  20  is provided in a first exhaust gas line  23  which collects exhaust gas of exhaust gas lines of the cylinders  13  and channels it into an exhaust gas collecting line  26  of the first exhaust gas tract  1 . A first catalytic converter  27 , in particular a precatalytic converter, and a second catalytic converter  28 , in particular a main catalytic converter, and a muffler  29  are provided along the running length of the exhaust gas collecting line  26 . Upstream of the first catalytic converter  27 , an exhaust gas line  24  ends at a mouth  25 , wherein the exhaust gas line  24  collects, via exhaust gas lines that are not specifically denoted, exhaust gas of the cylinders  14  of the first cylinder bank  11  and feeds it to the exhaust gas collecting line  26  by passing the turbocharger  20 . The cylinders  14  are configured such that they can be deactivated or at least their throughput be reduced.  
         [0037]      FIGS. 2 and 3  illustrate an advantageous embodiment which is modified with respect to the configuration shown in  FIG. 1  wherein a further turbocharger  50  is provided in the first exhaust gas tract  1 . The configuration in  FIGS. 2 and 3  corresponds largely to the configuration of  FIG. 1  and reference is made to  FIG. 1  for its explanation. Unlike in  FIG. 1 , a turbine  51  of the turbocharger is provided in the exhaust gas line  24  such that the turbine  51  can be supplied with exhaust gas of the cylinders  19 . As can be seen in  FIG. 2 , the two turbochargers  20  and  50  are dimensioned to be equal whereas, in accordance with  FIG. 3 , the turbochargers  20  and  50  are dimensioned to be different from one another. The cylinders  19  are expediently configured such that they cannot be deactivated. The compressor  52  of the turbine  50  feeds compressed air into the common intake line  17  and supplies together with the compressor  22  of the turbocharger  20  the common air plenum  18 . A respective part of the cylinders  13  and  19  of the first cylinder bank  11 , which are assigned to the first exhaust gas tract  1 , bypasses in each case one of the two turbochargers  20  and  50 , to be precise their turbines  21 ,  51 , that are assigned to the first cylinder bank  11  or the first exhaust gas tract  1 . Exhaust gas of the cylinders  13  bypasses the second turbocharger  50 , while exhaust gas of the cylinders  19  bypasses the first turbocharger  20 .  
         [0038]      FIG. 4  explains in a schematic representation a further preferred embodiment of the invention. An internal combustion engine  10 , which is embodied as a twelve-cylinder spark ignition engine, has two separate cylinder banks  11  and  12  with a number of cylinders  13  and  14  and, respectively,  15 . A first exhaust gas tract  1  and a second exhaust gas tract  2  extend separated from one another in a dual-flow configuration along their entire running length. A first turbocharger  20  is provided with its turbine  21  in the first exhaust gas tract  1  and with its compressor  22  in an intake line  17   a . The compressor  22  supplies an air-mass flow to the air plenum  18   a  of the first cylinder bank  11 . A second turbocharger  30  is provided with its turbine  31  in the second exhaust gas tract  2  and with its compressor  32  in an intake line  17   b . The compressor  32  supplies an air-mass flow to the air plenum  18   b  of the second cylinder bank  12 .  
         [0039]     Exhaust gas lines of the cylinders  14  of the first cylinder bank  11  merge via their bypass exhaust gas line  24  into an exhaust gas collecting line  26  of the first exhaust gas tract  1  wherein a first catalytic converter  27 , in particular a precatalytic converter, and a second catalytic converter  28 , in particular a main catalytic converter, and a muffler  29  are provided along the running length of the exhaust gas collecting line  26 . The cylinders  14  are preferably configured such that they can be deactivated, i.e. shut off. A further group of cylinders  13  feeds their exhaust gas via exhaust gas lines into an exhaust gas collecting line  23 , which feeds the exhaust gas to the turbine  21  of the first turbocharger  20 . The bypass exhaust gas line  24  feeds, at its mouth  25  downstream of the turbine  21 , into the exhaust gas collecting line  26 .  
         [0040]     The layout at the second cylinder bank  12  is constructed in a mirror symmetry to the first cylinder bank  11 . Exhaust gas lines of the cylinders  15  of the second cylinder bank  12  feed, via a bypass exhaust gas line  46 , into an exhaust gas collecting line  40  of the second exhaust gas tract  2 , wherein the bypass exhaust gas line  46  feeds into the exhaust gas collecting line  40  at a mouth  45 . A first catalytic converter  41 , in particular a precatalytic converter, and a second catalytic converter  42 , in particular a main catalytic converter, and a muffler  43  are provided along the running length of the exhaust gas collecting line  40 . The cylinders  15  are preferably configured such that they can be deactivated. A further group of cylinders  16  feeds their exhaust gas via exhaust gas lines into an exhaust gas collecting line  44 , which feeds the exhaust gas to the turbine  31  of the second turbocharger  30 . The bypass exhaust gas line  46  feeds, at its mouth  25  downstream of the turbine  31 , into the exhaust gas collecting line  40 .