Abstract:
A switching resonance intake system is provided an internal combustion engine with a first and a second cylinder bank. The cylinder banks are each coordinated with a resonance container with a group of swing pipes leading to the cylinders, and the resonance containers are joined together by resonance pipes provided with switching valves. In the intake system, the swing pipes coordinated with the one cylinder bank are connected to the resonance container adjacent to the other cylinder bank. The intake system is intended for use in an internal combustion engine with cylinder banks having a V-layout.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority, under 35 U.S.C. §119, of German application DE 10 2007 010 309.5, filed Feb. 23, 2007; the prior application is herewith incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention concerns a switching resonance intake system, hereinafter, intake system, for short, for an internal combustion engine, with a first and a second cylinder bank. The cylinder banks are each coordinated with a resonance container with a group of swing pipes leading to the cylinders, and the resonance containers are joined together by resonance pipes provided with switching valves. 
     Intake systems with resonance charging for optimal filling of the cylinders under different engine speeds and load ranges are familiar in the prior art. Thus, German patent DE 103 21 323 B3 represents and describes an intake system of the kind mentioned-above, configured for a 6-cylinder flat engine. This intake system by virtue of the fact that it is intended for a flat engine is symmetrical in configuration. Between the two resonance containers connected to the swing pipes there are provided two resonance pipes, while each resonance pipe has a central switching valve. The air supply to the intake system occurs in such a way that an air supply line has two individual pipes leading to one of these resonance pipes, which pass upstream into a single common pipe segment, in which a throttle valve is disposed. This concept of an intake system has proven to work well in a flat engine and thanks to the cylinder arrangement that is specific to a flat engine it enables a compact configuration for the intake system. The switching resonance pipes are disposed between the two resonance chambers. 
     A similar intake system is known from published, German patent application DE 198 42 724 A1, corresponding to U.S. Pat. No. 6,250,272. Here, a throttle valve is coordinated with each individual pipe leading to the resonance pipe. 
     A switching resonance intake system for an internal combustion engine with two cylinder banks in a V-layout is known from published, German patent application DE 39 40 486 A1. Here, two curved groups of swing pipes are opposite each other. Within the curve, resonance chambers are arranged, into which annular, length-adjustable resonance channels emerge. For this, the resonance channels on the one hand are provided with rotary slide valves; thanks to the rotation, an opening provided in the slide valve is moved and thereby changes the length of the resonance channels in continuous fashion. All resonance channels are oriented in the same direction. The swing pipes assigned to the one cylinder bank are connected to those resonance chambers adjacent to this cylinder bank. The resonance chambers are located between the resonance pipes and the swing pipes. The two resonance chambers are connected to each other by a channel, in which a switching valve is arranged. In relation to the lengthwise orientation of the internal combustion engine and, thus, the intake system, the swing pipes are arranged, on the one hand, around the resonance channels and, on the other hand, parallel to each other and in planes perpendicular to the lengthwise axis of the internal combustion machine. Due to the annular arrangement of the resonance pipes in this intake system, one has a configuration with a large structural height. 
     European patent EP 1 105 631 B1, corresponding to U.S. Pat. No. 6,435,152, shows an intake system with swing pipe and resonance system, in which resonance and swing pipes are disposed alternatingly next to each other in a ring around a central inner space. The inner space accommodates a rotary slide valve formed of several chambers, with which one can vary the length of the pipes continuously. Two resonance chambers are formed in the slide valve, which can be connected by a gate. The resonance pipes can be altered not only in the length, but also in their cross section, by shutting off one of the resonance pipes. 
     German patent DE 40 32 380 C2 discloses an intake system for an internal combustion engine of the in-line kind, wherein the intake system has two resonance chambers, to each of which are connected resonance pipes of different length or different cross section. These resonance pipes can be switched in groups and in the same direction for the two resonance chambers. The resonance chambers can be connected to each other by a gate. The air supply comes via the resonance pipes to the resonance chambers and from there to the swing pipes. 
     BRIEF SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a switching resonance intake system for an internal combustion engine that overcomes the above-mentioned disadvantages of the prior art devices of this general type, in which the switching resonance intake system is suitable for an internal combustion engine with cylinder banks in V-layout, and the intake system has a compact configuration. 
     With the foregoing and other objects in view there is provided, in accordance with the invention, a switching resonance intake system for an internal combustion engine having a first and a second cylinder bank. The switching resonance intake system contains resonance containers each being coordinated with the cylinder banks; a group of swing pipes leading to cylinders of the cylinder banks, the swing pipes associated with one of the cylinder banks being connected to the resonance container adjacent to the other one of the cylinder banks; resonance pipes joining together the resonance containers; and switching valves disposed in the resonance pipes. 
     The problem is solved for an intake system of the kind mentioned above in that the swing pipes coordinated with the one cylinder bank are connected to the resonance container adjacent to the other cylinder bank. 
     Accordingly, based on the configuration of the intake system according to the invention, the swing pipes connected to the one, first cylinder bank are connected to the resonance container which is disposed next to the other second cylinder bank and the swing pipes connected to the second cylinder bank are connected to the resonance container which is next to the first cylinder bank. This basic configuration of the intake system makes possible the most diverse modifications, and in all of them one can achieve a compact configuration for the intake system, thanks to the mentioned coordination of swing pipes and resonance containers. 
     Thus, according to a preferred embodiment of the invention, the swing pipes and/or the resonance pipes are disposed inside the resonance container. Thus, one has a nested arrangement for the parts bringing about the leading of air into the intake system. The volumes of the resonance containers enclose the swing pipes and/or the resonance pipes. 
     In particular, the swing pipes coordinated with the particular cylinder bank are passed through the resonance container that is next to the cylinder bank. 
     An especially compact configuration of the intake system can be achieved when the swing pipes of the intake system, starting from the cylinder banks, are curved in the direction of the top side of the intake system and/or the resonance pipes starting from the cylinder banks are curved in the direction of the bottom side of the intake system. In particular, the group of intake pipes of the intake system is curved in one direction and the group of resonance pipes of the intake system is curved in the opposite direction, in particular, the two groups are nested one in the other. Preferably, the resonance pipes are curved in a U-shape. 
     In view of the fundamental principle of the invention, it is considered especially advantageous to arrange the swing and resonance pipes at a slant to a plane running across the lengthwise axis of the internal combustion engine, i.e., transverse to the crankshaft axis of the internal combustion engine. Preferably, the swing pipes are disposed parallel to each other and the resonance pipes parallel to each other, while the orientation of the swing pipes and the resonance pipes differs from each other. 
     The switching valves associated with the resonance pipes are disposed in the end or the central regions of the resonance pipes. If they are disposed in the end regions, one gets an optimized charging, albeit with higher structural expense for the case when each resonance pipe is coordinated with a central switching valve. In the case when the switching valves are disposed in the end regions of the resonance pipes, each resonance pipe has two switching valves; when disposed in the central regions, there is one switching valve for each resonance pipe. 
     Preferably, the resonance pipes form a first and a second resonance stage, which can be switched independently of each other, wherein a first switchable resonance pipe forms the first resonance stage and two second switchable resonance pipes form the second resonance stage. 
     According to a special embodiment of the invention, the air supply of the intake system has two supply lines, which are connected directly to the resonance container. Thus, the air supply does not go to one of the resonance pipes, but directly to the two resonance containers. This produces an especially good charging outcome. 
     The air supply preferably has at least one throttle valve, wherein the two air supply lines are disposed between the throttle valve and the two resonance containers. It is quite conceivable to assign a throttle valve to each air supply line, which will then open in synchronization. The length of the particular supply line preferably corresponds to at least half the length of a resonance pipe. 
     In view of the concept of the invention, an especially compact intake system can be achieved by nesting the individual functional components of the intake system in each other. Structurally, this is accomplished, in particular, by a multipiece configuration of the housing components of the intake system. Thus, the intake system has a bottom shell, an insert placed in this, a middle shell, and a top shell. The bottom shell holds, in particular, the switching valves and the bottom shell has the flange connection to the cylinder head and reproduces a partial geometry of the resonance pipes and the swing pipes. The insert reproduces, in particular, a partial geometry of the resonance pipes. The middle shell has, in particular, a flange for the connection of the throttle valves, lower admission fittings for the swing pipes and a partition wall between the two resonance containers; moreover, the middle shell reproduces partial geometries of the resonance pipes and the swing pipes. The top shell, in particular, has admission fittings for the swing pipes and the resonance pipes and reproduces partial geometries of the resonance pipes and swing pipes. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a switching resonance intake system for 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. 
     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 SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a schematic functional diagram of a switching resonance intake system according to the invention; 
         FIG. 2  is a diagrammatic, three-dimensional representation of the intake system, seen from above at a slant; 
         FIG. 3  is a diagrammatic, three-dimensional view of the intake system shown in  FIG. 1 , seen from below at a slant; 
         FIGS. 4 to 7  are diagrammatic, three-dimensional views showing the formation of the intake system from the individual components; 
         FIG. 8  is a diagrammatic, cross sectional view through the intake system, cut in the region of an intake connector; and 
         FIGS. 9 to 12  are schematic representations of the intake system to illustrate the functional principle of the intake system. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures of the drawing in detail and first, particularly, to  FIG. 1  thereof, there is shown a switching resonance intake system  1  for an internal combustion engine configured as a V6 engine with a resonance container  2  and a resonance container  3 . The air supply of the intake system  1  has two supply lines  4  and  5 , which are connected directly to the resonance containers  2  and  3 . A throttle valve  6  governs the amount of air being supplied to the supply lines  4  and  5 . Instead of the one throttle valve  6  shown, there can be two synchronously opening throttle valves, each throttle valve cooperating with one supply line  4  or  5 . 
     The two resonance containers  2  and  3  are connected by two resonance pipes  7  and  8 . The resonance pipe  7  has a central switching valve  9 , the resonance pipe  8  has a central switching valve  10 . 
     The resonance container  2  is assigned a group of three swing pipes  11 , which are connected to one cylinder bank  12  of the internal combustion engine. The resonance container  3  is assigned a group of swing pipes  13 , which are connected to the other cylinder bank  14  of the internal combustion engine. The peculiarity of the intake system of the invention is, and the functional representation is to be interpreted in this sense from the aspect of the structural configuration of the intake system, that the resonance container  2  disposed at the left side is connected via the swing pipes  11  to the cylinder bank  12  located on the right side in the structural configuration and the resonance container  3  disposed on the right is connected via the swing pipes  13  to the cylinder bank  14  arranged on the left in the structural configuration. 
       FIGS. 2 and 3  illustrate the intake system  1  operating by the functional principle of  FIG. 1  in its structural configuration, namely, in three-dimensional views, shown at a slant from beneath and from above. One recognizes the multipiece makeup of the intake system  1 , especially the multipiece makeup of the housing  15  of the intake system  1 . The multipiece makeup is prominently shown by the representation of  FIGS. 4 to 7 . 
       FIGS. 1 to 7  shall now be described to explain the makeup of the intake system  1 . 
     The intake system  1  is used in a V6 engine. Depicted in the region of the bottom side of the housing  15  are the discharge openings  16  of the six swing pipes  11 ,  13 , while three swing pipes  11  form a first group and three swing pipes  13  form a second group. The reference number  12  indicates the cylinder bank coordinated with the swing pipes  11 , the reference number  14  indicates the cylinder bank coordinated with the swing pipes  13 . At the bottom side of the housing  15 , three resonance pipes are formed. The one resonance pipe is designated by the reference number  8  in the sense of the diagram in  FIG. 1 , the other two resonance pipes are designated by  7  in the sense of  FIG. 1 . In the region of the vertical central axis of the intake system, which goes across the axis of the crankshaft of the internal combustion engine, the central switching valves  9  and  10  are coordinated with the resonance pipes  7  and the resonance pipe  8 , respectively. The switching valves  9  and  10  can pivot on an axis  19 , while the common adjustment of the switching valves  9  is done by a servo-drive  20  and the adjustment of the switching valve  10  by a servo-drive  21 . In the position shown in  FIG. 4 , the switching valves  9  and  10  close the resonance pipes  7  and the resonance pipe  8 , respectively. In a position preferably rotated about 90 degrees, they open up the passage of the resonance pipes  7  and  8 . 
     For the air supply, the intake system  1  has a supply pipe connector  22 , which is provided with a vertical partition wall  23  ( FIG. 2 ), so that two separate airflows enter the housing  15 , forming the supply lines  4  and  5  in this way. Near the partition wall  23  and upstream from it, a throttle valve (see  FIG. 11 ) with circular cross section can pivot about a horizontal transverse axis of the supply pipe connector  22 , which in its blocked position closes the passage of the supply pipe connector  22  and can move along a semicircular front contour  24  of the partition wall  23  in order to reach its fully open position. The drive unit for the throttle valve is also not depicted. 
     The following description pertains to the individual parts of the intake system  1  and the assembly of these parts to form the intake system  1 . 
       FIG. 4  illustrates a lower shell  25  of the intake system  1 . This has the actuators for the two resonance stages, specifically, the drive unit  20  for the two switching valves  9  and the drive unit  21  for the switching valve  10 . Moreover, the lower shell  25  has a flange connection  26  near the cylinder bank  14  and a flange connection  27  near the cylinder bank  12 . Continuous holes for the fastening of the lower shell  25  to the cylinder head—eight holes are present—are indicated by reference number  28 . 
     Finally, a partial geometry of the resonance pipes  7  and  8  is reproduced in the lower shell  25 , and moreover a partial geometry of the swing pipes  11  and  13  is reproduced in the lower shell  25 . 
       FIG. 5  shows a molded part inserted from above into the lower shell  25 , being designated as insert  29 . The insert  29  is an additional shell for production layout of the resonance pipes, i.e., the resonance pipe  8  and the two resonance pipes  7 . From  FIG. 5  one notices that resonance pipes  7  and  8  are created with a U-shaped bend, the apex of the U being directed downward. Moreover, from  FIG. 5  one notices (and also refer to  FIG. 12  in this regard) that the resonance pipes  7  and  8  as well as the swing pipes  11  and  13  are disposed at an angle α to a lengthwise center axis  30  of the intake system  1 , and thus to the crankshaft axis of the V6 engine, which deviates from a right angle and is less than a right angle.  FIG. 12  shows this angle with respect to a parallel line to the lengthwise center axis  30 . Therefore the cylinders of the cylinder bank  12  of the engine are displaced slightly toward the cylinders of the cylinder bank  14  of the engine in the longitudinal direction. The bank offset results because two connecting rods are mounted in each journal in the crank mechanism of the engine. 
       FIG. 5 , finally, shows a central groovelike seat  31  extending along the length of the insert  29 , whose function shall be described in the next paragraph. 
       FIG. 6  illustrates a middle shell  32  connected to the lower shell  25  and insert  29  after they have been assembled. It contains the supply pipe connector  22 , the lower admission fittings  33  of the swing pipes  11  and  13 , as well as the partition wall  34  of the two resonance containers  2  and  3 , while the partition wall  34  being continuous in the lower region engages with the seat  31  (see  FIG. 8 ). 
     Moreover, as is to be seen from the representation of  FIG. 8 , partial geometries of the resonance pipes  7  and  8  and of the swing pipes  11  and  13  are reproduced in the middle shell  32 . 
       FIG. 7  shows the arrangement described thus far and an upper shell  37  placed thereon. The upper shell  37  reproduces the upper admission fittings for the swing pipes  11  and  13 , the admission fittings for the resonance pipes  7  and  8 , the partial geometry of the resonance pipes  7  and  8  and the swing pipes  11  and  13  (see  FIG. 8 ). Only  FIG. 2  shows that the upper shell  37  is closed with a cover  38 . This is not significant to the functioning of the intake system  1 . 
       FIG. 8  shows a cross section through the intake system  1  of the invention to illustrate the basic layout. It shows that the partition wall  34  forms the two resonance containers  2  and  3 , separated from each other. They basically occupy the space of the housing  15  that is not occupied by the swing pipes  11 ,  13  or the resonance pipes  7 ,  8 . From the trend of the cross section in  FIG. 8  one infers that the swing pipes and the resonance pipes are arranged inside the resonance containers  2  and  3 . This is clear from the trend of the cross section shown in  FIG. 8 . It is shown there that the swing pipe  8  is led through the resonance container  2 . If the trend of the cross section does not occur in the region of the swing pipe  11 , but rather that of the swing pipe  13  on the other side of the intake system, one gets a cross sectional pattern corresponding to the mirror image of  FIG. 8  with respect to the partition wall  34 . The functional principle per  FIG. 9  shows that the swing pipes  11  draw air from the resonance container  2  and the swing pipes  13  draw air from the resonance container  3 . The respective swing pipes  11  and  13  taper toward the cylinder bank  12  and  14 . 
       FIG. 10  shows a functional representation to illustrate the function of the resonance pipes  7 ,  8 . The respective resonance pipe  7  or  8  is U-shaped, and the length of the respective resonance pipes is the same. The switching valve  10  serves to open the resonance stage  1 , the switching valve  10  opens the resonance stage  2 . The cross section of the resonance stage  1 , i.e., that of the resonance pipe  8 , is smaller than the cross section of the resonance stage  2 , i.e., that of the combined cross section of the two resonance pipes  7 . 
       FIG. 11  shows the functional principle of the air intake of the swing pipes from the resonance containers. The swing pipes  11  draw air from the resonance container  3 , the swing pipes  13  draw air from the resonance container  2 . 
       FIG. 12  illustrates the functional principle of the intake module with regard to the resonance pipe  7 , forming the resonance stage  1 , and that of the two resonance pipes  8 , forming the resonance stage  2 . The diameter of the resonance pipe  7  corresponds to the diameter of the respective resonance pipe  8 , so that the combined diameter of resonance stage  2  is greater than the diameter of resonance stage  1 . The switching valve  9  serves to open the resonance stage  1 , the two synchronously operated switching valves  10  serve to open the resonance stage  2 . These switching valves  10  are shown in  FIG. 12  as a continuous bar. 
     The resonance intake system functions as follows: in a lower rpm region, resonance stage  1  and resonance stage  2  is closed. In a middle rpm region, resonance stage  1  is open and resonance stage  2  is closed. In an intermediate range between the medium rpm range and the upper rpm range, the resonance stage  1  is closed and resonance stage  2  is open. In an upper rpm range, resonance stage  1  and resonance stage  2  is open. 
     Thus, the intake system of the invention makes sure that the natural frequency of the intake system is adapted for optimal filling of the cylinder in a V-engine over the entire rpm range.