Abstract:
The object of this invention is that a suction device for an internal combustion engine is to be compact. The suction device comprising a casing having an air inlet and a plurality of outlets, a filter in the casing for filtering air from said air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes. According to the present invention, the suction device can be made compact to thereby effectively use an engine room of an automobile.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 08/715,627 filed Sep. 18, 1996; now U.S. Pat. No. 5,960,759 which is a divisional of application Ser. No. 08/307,461 filed Sep. 19, 1994 (now U.S. Pat. No. 5,638,784), the entire disclosures of which are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a suction device for supplying air and fuel to combustion chambers of an internal combustion engine, and more particularly to a suction device which can be constructed compactly. 
     In connection with a V-type internal combustion engine in which a plurality of cylinders are arranged in a V-shape, there is described a conventional suction device in U.S. Pat. Nos. 5,003,933 and 5,094,194, for example. In this conventional suction device, a plurality of individual suction pipes and a collector for distributing suction air to the individual suction pipes are integrated compactly, but an air cleaner, a suction air quantity detecting means, a throttle valve, and fuel injection valves are not integrated with the suction device. These latter elements are individually mounted. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a suction device which can be constructed compactly so as to integrate all parts from the air cleaner to the suction ports and eliminate any spaces other than an air passage for supplying suction air to an internal combustion engine, thereby making it possible to increase the space for mounting other parts and the internal combustion engine in an engine compartment of the automobile or to reduce the size of the engine compartment to more effectively use the space provided for the engine. 
     A casing of a suction device has such a shape as to be fitted within a space defined between right and left banks of a V-type internal combustion engine. The inside of the casing is partitioned into several spaces for mounting an air cleaner, an air collector, and a plurality of individual suction pipes in such a manner that these elements are arranged adjacent to each other. 
     The air cleaner, the air collector, and the individual suction pipes are arranged adjacent to each other, being separated by a partition, thereby forming an air passage in each element. Accordingly, all parts constituting the suction device can be integrated, and any unnecessary spaces, other than the air passage, can be eliminated to thereby realize a suction device having a compact structure. 
     In summary, the present invention provides a compact suction device including all parts from the air cleaner to the suction ports. 
     The suction device has the following functions. Air admitted from an inlet  5  of an air cleaner  3  is introduced through a passage  6  and an air cleaner element  33  to a suction air quantity detecting means  7 . A throttle valve  8  is located downstream of the suction air quantity detecting means  7 . The air passing through the throttle valve  8  is introduced through an air collector  10  to individual suction pipes  11  corresponding to the cylinders of the engine. Thereafter, the air is sucked through suction ports  4 , forming outlets of the suction device, into combustion chambers  12  of the engine. The passage  6 , the individual suction pipes  11 , and the air collector  10  are arranged adjacent to each other through a partition or directly. 
     Further, a control unit  13  for controlling the engine is located in the passage  6  downstream of the inlet  5  of the air cleaner  3 . 
     According to the present invention, the suction device, including the elements from the air cleaner to the suction ports, can be made compact, to thereby effectively use the space in the engine compartment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional front view of a suction device according to a first preferred embodiment of the present invention, as mounted on a V-type internal combustion engine. 
     FIG.  2 ( a ) is a schematic sectional front view taken along line A—A in FIG. 2 b , which is a schematic sectional side view of the suction device. 
     FIG. 3 is a schematic sectional side view of a suction device according to a second preferred-embodiment of the present invention. 
     FIG. 4 is a schematic sectional side view of a suction device according to a third preferred embodiment of the present invention. 
     FIG. 5 is a view illustrating a flow of air in the suction device according to the first preferred embodiment. 
     FIG. 6 is an air flow diagram relating to a flow of air in the suction device according to the first preferred embodiment. 
     FIG. 7 is a view illustrating a flow of air in the suction device according to the first preferred embodiment. 
     FIG. 8 is a schematic side view illustrating a positional relation between the suction device and the internal combustion engine. 
     FIG. 9 is a schematic side view illustrating a control unit in the suction device. 
     FIG. 10 is a schematic sectional side view of a suction device according to a fourth preferred embodiment of the present invention. 
     FIG. 11 is a schematic diagram illustrating an air passage shown in FIG.  10 . 
     FIG. 12 is a schematic sectional side view of a suction device according to a fifth preferred embodiment of the present invention. 
     FIG. 13 is a schematic sectional side view of a suction device according to a sixth referred embodiment of the present invention. 
     FIG. 14 is a cross section taken along the line C—C in FIG.  13 . 
     FIG. 15 is a schematic sectional side view of a suction device according to a seventh preferred embodiment of the present invention. 
     FIG. 16 is a cross section taken along the line C—C in FIG.  15 . 
     FIG. 17 is a schematic side view illustrating a swirl passage provided in a suction device according to an eighth preferred embodiment of the present invention. 
     FIG. 18 is a schematic plan view illustrating swirl control valves provided in the suction device according to the eighth preferred embodiment. 
     FIG. 19 is a schematic front view illustrating the swirl control valves shown in FIG.  18 . 
     FIG. 20 is an enlarged view of an essential part shown in FIG.  19 . 
     FIG. 21 is an enlarged view of a modification of each swirl control valve in the eighth preferred embodiment. 
     FIG. 22 is a schematic perspective view illustrating a preferred embodiment of the swirl passage shown in FIG.  17 . 
     FIG. 23 is a schematic perspective view illustrating another preferred embodiment of the swirl passage shown in FIG.  17 . 
     FIG. 24 is a schematic perspective view illustrating the flows of air and fuel in forming a swirl. 
     FIG. 25 is a schematic sectional front view of a suction device according to a ninth preferred embodiment of the present invention. 
     FIG. 26 is a schematic sectional side view of the suction device shown in FIG.  25 . 
     FIG. 27 is a cross section taken along the line C—C in FIG.  26 . 
     FIG. 28 is a view similar to FIG. 27, showing a tenth preferred embodiment of the present invention. 
     FIG. 29 is a top plan view illustrating a layout in an engine compartment of an automobile. 
     FIG. 30 is a cross section taken along the line X—X in FIG.  29 . 
     FIG. 31 is a schematic sectional side view of a suction device according to an eleventh referred embodiment of the present invention. 
     FIG. 32 is a schematic sectional front view of a suction device according to a twelfth preferred embodiment of the present invention. 
     FIG. 33 is a sectional side view of a suction device according to a thirteenth preferred embodiment of the present invention. 
     FIG. 34 is a cross section taken along the line B—B in FIG.  33 . 
     FIG. 35 is a cross section taken along the line A—A in FIG.  33 . 
     FIG. 36 is a schematic diagram illustrating a resonance suction length in the suction device shown in FIG. 33 when a variable induction valve is closed. 
     FIG. 37 is a diagram similar to FIG. 36, when the variable induction valve is opened. 
     FIG. 38 is a sectional side view of a suction device according to a fourteenth preferred embodiment of the present invention 
     FIG. 39 is a cross section taken along the line B—B in FIG.  38 . 
     FIG. 40 is a cross section taken along the line A—A in FIG.  38 . 
     FIG. 41 is a horizontal sectional view of a preferred embodiment of the an air flow meter shown in FIG.  38 . 
     FIG. 42 is a left side view of the air flow meter shown in FIG.  41 . 
     FIG. 43 is a view similar to FIG. 41, showing another preferred embodiment of the air flow meter. 
     FIG. 44 is a schematic diagram illustrating a resonance suction length in the suction device shown in FIG. 38 when a variable induction valve is closed. 
     FIG. 45 is a diagram similar to FIG. 44, when the variable induction valve is opened. 
     FIG. 46 is a sectional side view of a suction device according to a fifteenth preferred embodiment of the present invention. 
     FIG. 47 is a cross section taken along the line C—C in FIG.  46 . 
     FIG. 48 is a cross section taken along the line A—A in FIG.  46 . 
     FIG. 49 is a cross section taken along the line B—B in FIG.  46 . 
     FIG. 50 is a sectional side view of a suction device according to a sixteenth preferred embodiment of the present invention. 
     FIG. 51 is a cross section taken along the line B—B in FIG.  50 . 
     FIG. 52 is a cross section taken along the line A—A in FIG.  50 . 
     FIG. 53 is a sectional side view of a fuel gallery provided in a suction device according to a seventeenth preferred embodiment of the present invention. 
     FIG. 54 is a sectional side view of the suction device including the fuel gallery shown in FIG.  53 . 
     FIG. 55 is a sectional side view of a suction device according to an eighteenth preferred embodiment of the present invention. 
     FIG. 56 is a cross section taken along the line A—A in FIG.  55 . 
     FIG. 57 is a top plan view illustrating a layout in an engine compartment of an automobile when an engine is longitudinally mounted. 
     FIG. 58 is a view similar to FIG. 57, when the engine is transversely mounted. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first preferred embodiment of the present invention is shown in FIG. 1, which is a sectional front view of right and left cylinder trains  1  and  2  of an internal combustion engine  20  and a suction device  21 . The internal combustion engine  20  is a V-type internal combustion engine wherein the right and left cylinder trains  1  and  2  are so arranged as to form a V-shape, as viewed in front elevation. While the number of cylinders in the V-type internal combustion engine  20  is six in this preferred embodiment, it may be eight or twelve as known in the art. The suction device  21  has a casing including an inlet  5  to an air cleaner  3  and suction ports  4  forming a plurality of outlets to the engine cylinders, the suction device  21  being located in a space defined between the right and left cylinder trains  1  and  2 . 
     Thus, the suction device  21  is designed to have a compact structure. FIG.  2 ( a ) is a sectional front view of the suction device  21  with the right cylinder train  1  not shown, and FIG.  2 ( b ) is a sectional side view of the suction device  21 . As shown in FIGS.  2 ( a ) and  2 ( b ), air admitted from an inlet  5  of the air cleaner  3  is introduced through a passage  6  and an air cleaner element  33  to a suction air quantity detecting means  7 . The suction air quantity detecting means  7  is an air flow meter of any type, such as a hot-wire type, movable vane type, or Karman vortex type. A throttle valve  8  is provided downstream of the suction air quantity detecting means  7 . The throttle valve  8  is electrically driven by a motor  9  in this preferred embodiment; however, it may be mechanically driven by a wire. The air passing through the throttle valve  8  is introduced through a collector  10  into a plurality of individual suction pipes  11  respectively communicating with a plurality of cylinders of the engine  20 . 
     More particularly, the air is sucked through the suction ports  4 , forming the outlets of the suction device  21 , into combustion chambers  12  of the engine  20 . In order to make the structure compact, the passage  6  of the air cleaner  3 , the individual suction pipes  11 , and the collector  10  are arranged in this order from the upper side of the suction device in adjacent relationship to each other through partitions or directly. The order of arrangement of these sections is not critical to the invention, but the passage  6  of the air cleaner  3 , the collector  10 , and the individual suction pipes  11  may be arranged in this order from the upper side of the suction device. A control unit  13  is located in the passage  6  of the air cleaner  3  at a downstream portion thereof in consideration of compactibility and coolability. With this arrangement, the control unit  13  can be cooled by the air flowing in the passage  6 . To ensure the compactibility, the control unit  13  is located in the passage  6  just over the top of the individual suction pipes  11  or the collector  10 . A plurality of fuel injection valves  91  for injecting fuel are respectively located in the suction ports  4  of the individual suction pipes  11 , and a plurality of air passages (swirl passages)  14  for forming a swirl of air in the combustion chambers  12  are respectively located in the suction ports  4 . 
     Further, a plurality of swirl control valves  15  for controlling the quantity of suction air flowing through the suction ports  4  and the quantity of suction air flowing through the air passages  14  are respectively located in the individual suction pipes  11 . In this preferred embodiment, all or at least one of the individual suction pipes  11 , the swirl control valves  15 , and the fuel injection valves  91  are provided on the collector  10  serving as a negative pressure chamber downstream of the throttle valve  8 . While the suction air quantity detecting means  7  is located upstream of the throttle valve  8  in this preferred embodiment, the detecting means  7  may be located downstream of the throttle valve  8 . The throttle valve  8  is mounted on a member (a portion below the line A—A in FIG.  2 ( b )) forming the suction ports  4  respectively communicating with suction ports  17  formed in the engine  20 . 
     A second preferred embodiment of the present invention is shown in FIG.  3 . In this preferred embodiment, the individual suction pipes  11  and the suction ports  4  communicating with the suction ports  17  of the engine  20  are formed in a single member (a portion below the line A—A in FIG.  3 ), and the throttle valve  8  is mounted to this member. 
     A third preferred embodiment of the present invention is shown in FIG.  4 . In this preferred embodiment, the collector  10  is formed just above the individual suction pipes  11 . The air passing through the throttle valve  8  is first raised to the collector  10  and then flows down into the individual suction pipes  11 . With this arrangement, the individual suction pipes  11  are located nearer to the engine  20 , so that the suction device  21  can be easily mounted on the engine  20  with a simple structure. 
     FIGS. 5,  6 , and  7  illustrate the flow of suction air in the first preferred embodiment shown in FIG.  2 ( b ). The air passage from the inlet  6  of the air cleaner  3  to the collector  10  is formed so that the air flows along a certain plane A, as shown in FIG.  6 . On the other hand, the air passage from the collector  10  to the suction ports  4  is formed so that the air flows along a certain plane B perpendicular to the plane A, as also shown in FIG.  6 . Thus, the flow of suction air changes in three-dimensional direction at the collector  10  only, thereby reducing the suction resistance. 
     FIG. 8 schematically illustrates a positional relation between the internal combustion engine  20  and the suction device  21  as viewed in side elevation. Reference numerals  22  and  23  denote a front end and a rear end of the engine  20 , respectively. The air inlet  5  of the suction device  21  is located just above the front end  22  of the engine  20 . Accordingly, when the engine  20  is longitudinally mounted on an automobile in such a manner that the front end  22  of the engine  20  is directed to the front of the automobile, cool air can be readily introduced into the air inlet  5  of the suction device  21 . Further, a pulley  24  and a fan belt  25  are provided at the front end  22  of the engine  20 , so that there is no space for arranging the suction air quantity detecting means  7 , the throttle valve  8 , and a vertical passage  26  (see FIG. 7) at the front end portion of the suction device  21 . Accordingly, these elements are arranged at the rear end portion of the suction device  21  just above the rear end  23  of the engine  20 . In the suction device  21 , these elements are arranged behind the individual suction pipes  11 . 
     FIG. 9 schematically illustrates the arrangement of the control unit  13 . As mentioned above, the control unit  13  is located downstream of the air cleaner element  33  in the air passage  6  of the air cleaner  3  in order that the control unit  13  can be cooled by cool air just introduced from the air inlet  5 . Further, in consideration of the compactibility of the collector  10  and the individual suction pipes  11  and the maintainability of the control unit  13 , the control unit  13  is located above a portion  29  where the collector  10  and the individual suction pipes  11  are arranged. Since the control unit  13  must be adjusted upon delivery or inspection after being manufactured, the control unit  13  is located at such a position that a lid (not shown) provided on the suction ports  4  can be removed at a portion upstream of a throttle valve mounting portion  30 . 
     A fourth preferred embodiment of the present invention is shown in FIG.  10 . In this preferred embodiment, the air cleaner element  33  is located in a front portion of the air passage  6  of the air cleaner  3 , and the suction air quantity detecting means  7  is located in a rear passage portion  27  downstream of the air cleaner element  33 . With this arrangement, no bent passage portion is present upstream of the suction air quantity detecting means  7 , but a long straight passage portion can be ensured upstream of the detecting means  7 , thereby reducing detection error of the detecting means  7 . Further, the throttle valve  8  is located in the vertical passage  26  for the purpose of prevention of fixation of the valve  8  due to stain and for the purpose of improvement in maintainability. 
     FIG. 11 schematically illustrates the arrangement of the air passage in the fourth preferred embodiment of FIG.  10 . The air cleaner  3 , the suction air quantity detecting means  7 , the throttle valve  8 , and the collector  10  leading to the individual suction pipes  11  having the fuel injection valves  91  are arranged adjacent to each other. That is, as shown in FIG. 11, mounting members A, B, C, and D for respectively mounting the above elements  3 ,  7 ,  8 , and  10  are connected together in an integral or direct fashion. With this arrangement, it is possible to reduce detection error of the detecting means  7  due to suction air pulsation caused by blow-back from the combustion chambers upon full opening of the throttle valve  8 . That is, since the air passage from the air cleaner  3  to the collector  10  can be shortened, the volume of the air column in which vibration occurs can be reduced, to thereby reduce the pulsation. 
     A fifth preferred embodiment of the present invention is shown in FIG.  12 . In this preferred embodiment, a circuit  32  of the suction air quantity detecting means  7  is located inside the control unit  13 , thereby saving space. 
     A sixth preferred embodiment of the present invention is shown in FIGS. 13 and 14. FIG. 14 is a cross section taken along the line C—C in FIG.  13 . Referring to FIG. 14, reference numerals  11   a ,  11   b , and  11   c  denote individual suction pipes extending along a left bank of an internal combustion engine, and reference numerals  11   d ,  11   e , and  11   f  denote individual suction pipes extending along a right bank of the internal combustion engine. The individual suction pipes  11   a ,  11   b , and  11   c  are arranged in a direction A, and the individual suction pipes  11   d ,  11   e , and  11   f  are also arranged in the direction A. The throttle valve  8  lies on a line of symmetry between the arrangement of the individual suction pipes  11   a  to  11   c  and the arrangement of the individual suction pipes  11   d  to  11   f . Further, a throttle shaft of the throttle valve  8  extends in a direction B perpendicular to the direction A. This arrangement of the throttle valve  8  is important because the throttle valve  8  is located adjacent to the collector  10 . With this arrangement, the throttle valve  8  is rotated to equally open to the left arrangement of the individual suction pipes  11   a  to  11   c  and the right arrangement of the individual suction pipes  11   d  to  11   f , thereby effecting uniform distribution of air to the left and right arrangements. 
     A seventh preferred embodiment of the present invention is shown in FIGS. 15 and 16. FIG. 16 is a cross section taken along the line C—C in FIG.  15 . In this preferred embodiment, the throttle valve  8  is mounted in a vertical passage  34 . Similar to the sixth preferred embodiment shown in FIGS. 13 and 14, the throttle shaft of the throttle valve  8  extends in a direction B perpendicular to a direction A of arrangement of individual suction pipes  11   a  to  11   c  or arrangement of individual suction pipes  11   d  to  11   f . Accordingly, uniform distribution of air to both arrangements can be effected. 
     An eighth preferred embodiment of the present invention is shown in FIGS. 17 to  24 . FIG. 17 schematically shows a mechanism for forming a swirl of air in a combustion chamber  50  of an internal combustion engine. A suction port  46 , as a downstream end portion of an individual suction pipe  47 , is arranged adjacent to a collector  45  downstream of a throttle valve (not shown) through a partition  51  in consideration of space saving. A suction passage (swirl passage)  49  is formed so as to connect the collector  45  through the partition  51  to the suction port  46 . Further, a swirl control valve  48  is located in the individual suction pipe  47  between the collector  45  and an outlet  52  of the suction passage  49 . When the swirl control valve  48  is closed, suction air is allowed to flow through the suction passage  49 , whereas when the swirl control valve  48  is opened, the suction air is allowed to flow primarily through the individual suction pipe  47 . With this arrangement, the suction passage  49  can be easily formed because the collector  45  and the individual suction pipe  47  are adjacent to each other through the partition  51 . 
     FIGS. 18 to  21  show a modified arrangement of plural swirl control valves  48  applied to a V-type internal combustion engine. As shown in FIGS. 18 to  20 , a plurality of individual suction pipes  53  and  54  of the V-type internal combustion engine are alternately arranged so as to intersect with each other at an intermediate portion in a space between right and left banks of the engine. The swirl control valves  48  are located in the individual suction pipes  53  and  54  at this intermediate portion, and are supported on a common shaft  55 . If two or more support shafts for the swirl control valves  48  were provided, an increased space would become necessary, causing an increase in cost. As shown in FIG. 21, each swirl control valve  48  may be formed as a swirl control valve  100  partially cut away, as shown by a dashed line. Further, in the case where each suction port has two main passages, each swirl control valve may be formed as a swirl control valve partially cut away so as to close one of the two main passages. 
     FIG. 22 shows a preferred embodiment of the suction passage  49 . In FIG. 22, reference numerals  56   a  and  56   b  denote two suction valves provided in each cylinder of an internal combustion engine, and reference numeral  57  denotes a surface of the connection between the individual suction pipes  47  and the engine head. Two suction passages (swirl passages)  49   a  and  49   b , through which the collector  45  communicates with the suction port  46 , are formed on an outer wall surface of each individual suction pipe  47 . That is, the walls of the suction passages  49   a  and  49   b  are partially formed by parts  59   a  and  59   b  of the walls of the individual suction pipe  47 . The suction passages  49   a  and  49   b  have respective outlets  52   a  and  52   b  opening toward the suction valves  56   a  and  56   b , respectively. 
     FIG. 23 shows another preferred embodiment of the suction passage  49 . In this preferred embodiment, the outlets  52   a  and  52   b  of the suction passages  49   a  and  49   b , formed adjacent to each individual suction pipe  47 , are open to the connection surface  57  independently of an outlet of the suction port  46 . The outlets  52   a  and  52   b  are respectively connected to inlets  61   a  and  61   b  of two suction passages (swirl passages)  63   a  and  63   b  formed in the engine head. Outlets  62   a  and  62   b  of the suction passages  63   a  and  63   b  open near the suction valves  56   a  and  56   b , respectively. With this arrangement, a strong swirl can be easily formed in the combustion chamber. 
     FIG. 24 shows the flows of air and fuel. Reference numerals  64   a  and  64   b  denote the flows of air blown from the suction passages  49   a  and  49   b , respectively, and reference numeral  65  denotes the sprays of fuel injected from the fuel injection valve  91 . The outlets  52   a  and  52   b  of the suction passages  49   a  and  49   b  are directed so that the air flows  64   a  and  64   b  do not directly blow against the fuel sprays  65 . If the air flows  64   a  and  64   b  having a high velocity blow directly against the fuel sprays  65 , the fuel sprays  65  will change their directions so as to strike against a wall surface of the suction passage in the engine head, so that the fuel sprays  65  will not properly enter the cylinder of the internal combustion engine. To avoid this problem, the nozzles of the fuel injection valve  91  are arranged so that the fuel sprays  65  may be directed to central portions of the suction valves  56   a  and  56   b , and the outlets  52   a  and  52   b  of the suction passages  49   a  and  49   b  are arranged in direction so that the air flows  64   a  and  64   b  may be directed to outside end portions of the suction valves  56   a  and  56   b . Also, in the case of a single suction valve per cylinder, the fuel spray from the fuel injection valve may be directed to a central portion of the suction valve, and the air flow from the suction passage  49  directed to an outer peripheral portion of the suction valve. 
     A ninth preferred embodiment of the present invention is shown in FIGS. 25 to  27 . FIG. 27 is a cross section taken along the line C—C in FIG.  26 . In this preferred embodiment, a partition  70  is formed in the collector  10  at a transversely central position thereof to define left and right collectors  74   a  and  74   b . Accordingly, the air passing through the throttle valve  8  is divided by the partition  70  to flow into the left and right collectors  74   a  and  74   b . Further, a variable induction valve  73  is mounted on the partition  70  so as to effect communication between the left and right collectors  74   a  and  74   b . The variable induction valve  73  is operated according to an operational condition of the engine, thereby changing the effective suction length of an individual suction pipe  71  or  72 . That is, when the variable induction valve  73  is closed in a low-speed condition of the engine, the effective suction length can be made large, whereas when the variable induction valve  73  is opened in a high-speed condition of the engine, the effective suction length can be made small. 
     A tenth preferred embodiment of the present invention is shown in FIG. 28, which is a view similar to FIG.  27 . In this preferred embodiment, a partition  75  separating the collector  10  into the left and right collectors  74   a  and  74   b  is extended rearwardly between two throttle valves  77   a  and  77   b  to a downstream position of a suction air quantity detecting means (not shown), which is located upstream of the throttle valves  77   a  and  77   b . Thus, an extended partition  76  is formed between the throttle valves  77   a  and  77   b  and the suction air quantity detecting means. That is, an air passage where the suction air quantity detecting means is located is formed as a single passage, but an air passage from a downstream area of the detecting means through the throttle valves  77   a  and  77   b  to the collectors  74   a  and  74   b  is formed as dual separate passages. The variable induction valve  73  mounted on the partition  75  in this preferred embodiment is operated similarly to the ninth preferred embodiment shown in FIG.  27 . 
     FIGS. 29 and 30 schematically illustrate a layout in an engine compartment  80  of an automobile in which a suction device  81  according to the present invention is mounted. FIG. 30 is a cross section taken along the line X—X in FIG.  29 . The suction device  81  is located in a space defined between left and right banks of a V-type internal combustion engine  82 . Reference numerals  83   a  and  83   b  denote spaces where an air cleaner, a throttle valve, etc. were conventionally located. In accordance with the present invention, since these elements are incorporated in the suction device  81 , any other parts located in the spaces  83   a  and  83   b  can be easily maintained or inspected. 
     An eleventh preferred embodiment of the present invention is shown in FIG.  31 . In this preferred embodiment, an EGR (exhaust gas recirculation) passage  90  is provided in the suction device  21  so that outlets  93  of the EGR passage  90  respectively open into the individual suction pipes at positions downstream of the fuel injection valves  91 . If an EGR device is provided in a collector  90  as in the prior art, the fuel injection valves located downstream of the EGR collector are stained by an EGR gas. To avoid this problem, the outlets  93  of the EGR passage  90  in this preferred embodiment are located downstream of the fuel injection valves  91  to thereby prevent the staining of the valves  91  by the EGR gas. 
     A twelfth preferred embodiment of the present invention is shown in FIG.  32 . In this preferred embodiment, an EGR passage  95  is connected to a swirl passage  94  for forming a swirl of air in the combustion chamber of the internal combustion engine. With this arrangement, suction air from the swirl passage  94  and EGR gas from the EGR passage  95  can be uniformly mixed in the combustion chamber. 
     A thirteenth preferred embodiment of the present invention is shown in FIGS. 33 to  37 . FIG. 34 is a cross section taken along the line B—B in FIG. 33, and FIG. 35 is a cross section taken along the line A—A in FIG. 33. A partition  105  for equally dividing an air passage in a suction device  100  into right and left areas is provided in a collector  101 , a throttle portion  102  in which the throttle valve  8  is located, a vertical passage  103 , and an upper horizontal passage  104 . Further, a variable induction valve  106  is mounted on the partition  105  so as to effect communication between the right and left portions of the collector  101 . In the upper horizontal passage  104 , the partition  105  extends from the rear end of the passage  104  to an area downstream of an air flow meter  107 . The air flow meter  107  is located in a single air Passage, and an air cleaner element  108  is located upstream of the air flow meter  107  in this single air passage. The purpose of provision of the partition  105  is to obtain a supercharging effect. That is, when the variable induction valve  106  is closed, a supercharging effect can be obtained in a low-speed condition of an internal combustion engine; whereas, when the variable induction valve  106  is opened, the effective point of the supercharging effect is shifted to a high-speed region of operation of the engine. 
     This effect will be described in detail with reference to FIGS. 36 and 37. In these drawings, reference numeral  110  denotes a cylinder of the internal combustion engine, and reference numeral  109  denotes an individual suction pipe of the suction device  100 . FIG. 36 shows a closed condition of the variable induction valve  106 . In this closed condition, the resonance suction length participating in the supercharging is the sum of the length of the individual suction pipe  109 , the length of collector  101 , the throttle portion  102 , the length of the vertical passage  103 , and the length of the upper horizontal passage  104 , which distance is a considerably large length. Accordingly, the resonance frequency is low, and a resonance effect occurs in a low-speed condition of the engine. On the other hand, when the variable induction valve  106  is opened as shown in FIG. 37, the resonance suction length becomes the length of the individual suction pipe  109  plus the distance from it to the variable induction valve  106 . Thus, the resonance suction length is shortened, and the resonance effect therefore occurs in a high-speed condition of the engine. In this manner, the resonance suction length can be changed by opening and closing the variable induction valve  106  to thereby obtain a resonance supercharging effect in a wide operational range of the engine. 
     A fourteenth preferred embodiment of the present invention is shown in FIGS. 38 to  45 . FIG. 39 is a cross section taken along the line B—B in FIG. 38, and FIG. 40 is a cross section taken along the line A—A in FIG.  38 . This preferred embodiment is similar to the thirteenth preferred embodiment with the exception that the partition  105  is extended to a position upstream of the air flow meter  107  and downstream of the air cleaner element  108  in the upper horizontal passage  104 . Accordingly, the air flow meter  107  is provided so as to pass through the partition  105  and extend across the upper horizontal passage  104 . When the variable induction valve  106  is closed, the suction length can be made larger than that in the thirteenth preferred embodiment shown in FIG. 33. A control unit  111  is located in the upper horizontal passage  104 , so as to be cooled by air flow. 
     In this preferred embodiment, the air flow meter  107  is so designed as to measure the quantities of air flows in two air passages  121  and  122  separated by the partition  105 . FIGS. 41 and 42 show a preferred embodiment of the air flow meter  107 . FIG. 42 is a cross section taken along the line A—A in FIG.  41 . As shown in FIGS. 41 and 42, lead wires  118  are embedded in a probe  112 , and two hot wires  113  and  114  are connected to the lead wires  118 . The two hot wires  113  and  114  are located in two air passages  116  and  117  respectively communicating with the two air passages  121  and  122  separated by the partition  105 . Accordingly, the velocities of air flows in the two air passages  121  and  122  can be measured by the hot wires  113  and  114 , respectively. Then, an average of the velocities thus measured is calculated to thereby detect the quantity of suction air sucked into the internal combustion engine. Reference numeral  115  denotes a resistor for compensating for suction air temperature. The resistor  115  is located in the air passage  117  in this preferred embodiment; however, it may be located in the air passage  116 . FIG. 43 is another preferred embodiment of the air flow meter  107 . In this preferred embodiment, the air flow meter  107  has a common air inlet  120  equally exposed to the two air passages  121  and  122  separated by the partition  105 , and has two air outlets  123  and  124  respectively communicating with the two air passages  121  and  122 . Further, a single hot wire  119  is located in a common air passage formed just downstream of the air inlet  120 . With this arrangement, an average velocity of air flows in the two air passages  121  and  122  can be measured by the hot wire  119 . 
     FIGS. 44 and 45 schematically illustrate a resonance supercharging effect in the fourteenth preferred embodiment shown in FIG.  38 . FIG. 44 shows a closed condition of the variable induction valve  106 . In this closed condition, the resonance suction length is a total distance from the individual suction pipe  109  to the upstream side of the air flow meter  107 . Accordingly, the resonance suction length in this preferred embodiment can be made larger than that in the thirteenth preferred embodiment shown in FIG. 36, so that an engine speed at which the resonance supercharging effect occurs can be shifted to a lower point as compared with the embodiment shown in FIG.  36 . On the other hand, when the variable induction valve  106  is opened, as shown in FIG. 45, the resonance suction length is shortened as shown by a wavy line similar to the embodiment shown in FIG.  37 . Thus, an engine speed range where the resonance supercharging effect occurs can be more greatly widened as compared with the embodiment shown in FIGS. 36 and 37. 
     A fifteenth preferred embodiment of the present invention is shown in FIGS. 46 to  49 . FIG. 47 is a cross section taken along the line C—C in FIG. 46; FIG. 48 is a cross section taken along the line A—A in FIG. 46; and FIG. 49 is a cross section taken along the line B—B in FIG.  46 . In this preferred embodiment, a part of the partition  105  is utilized as a substrate for a control unit  125 . With this arrangement, it is unnecessary to define a special space for locating the control unit  125 . The flow of suction air will be described with reference to FIGS. 47 to  49 . The suction air passes through the air cleaner element  108  and is then divided by the partition  105  in the upper horizontal passage  104  as shown in FIG.  47 . Then, the suction air flows down in the vertical passage  103  and passes through the throttle portion  102  as shown in FIG.  48 . Then, the suction air enters the collector  101  and is led from inlets  126  of individual suction pipes to suction ports  127  of an internal combustion engine, as shown in FIG.  49 . 
     A sixteenth preferred embodiment of the present invention is shown in FIGS. 50 to  52 . FIG. 51 is a cross section taken along the line B—B in FIG. 50, and FIG. 52 is a cross section taken along the line A—A in FIG.  50 . In this preferred embodiment, a part of the vertical partition  105  is utilized as a substrate for the control unit  125  similar to the fifteenth preferred embodiment shown in FIG.  46 . Further, various wiring patterns connected between the control unit  125  and various elements, such as the air flow meter  107  and the throttle valves  8 , are formed on the vertical partition  105  and a horizontal partition  140 . More specifically, a wiring pattern  137  connected to a power switch  130  for an igniter is printed on the horizontal partition  140  and the vertical partition  105 . Similarly, there are printed on the horizontal partition  140  and/or the vertical partition  105  a wiring pattern  138  connected to the air flow meter  107 , a wiring pattern  136  connected to an actuator  131  for driving the variable induction valve  106 , a wiring pattern  139  connected to a motor  132  for driving the throttle valves  8 , and a wiring pattern  135  connected to the fuel injection valves  91 . With this arrangement, no wire harnesses are required, thereby providing various effects, such as weight reduction, cost reduction, and space saving. The flow of suction air in this preferred embodiment is similar to that in the fifteenth preferred embodiment shown in FIGS. 47 to  49 . 
     A seventeenth preferred embodiment of the present invention is shown in FIGS. 53 and 54. In this preferred embodiment, a wiring arrangement  142  is built in a fuel gallery  141  connected to the fuel injection valves  91 . The wiring  142  is electrically connected to each fuel injection valve  91  to transmit a signal for controlling a valve opening timing and a valve opening period of each fuel injection valve  91 . A power element  143  for driving the fuel injection valves  91  and a fuel pressure regulator  144  are mounted on the fuel gallery  141 . While the power element  143  is heated, it is cooled by fuel flowing in a fuel passage  145  formed in the fuel gallery  141 . The wiring  142  is connected to a terminal  146 , which is in turn connected to a wiring pattern  147  leading to the control unit  125 , as shown in FIG.  54 . With this arrangement, the construction of wiring to the fuel injection valves  91  can be simplified. 
     An eighteenth preferred embodiment of the present invention is shown in FIGS. 55 and 56. FIG. 56 is a cross section taken along the line A—A in FIG.  55 . In this preferred embodiment, an EGR (exhaust gas recirculation) device effective for purification of an exhaust gas is provided. The exhaust gas from an exhaust pipe (not shown) is introduced from a passage  152  through a solenoid valve  151  to a passage  148 . As shown in FIG. 56, the passage  148  is formed in the vertical partition  105 , and communicates through branch pipes  150  respectively to individual suction pipes  149 . Accordingly, the exhaust gas is supplied from the passage  148  through the branch pipes  150  and the individual suction pipes  149  to cylinders of an internal combustion engine. The quantity of the exhaust gas to be supplied to the passage  148  is controlled by the solenoid valve  151 . 
     FIGS. 57 and 58 illustrate different layouts of a suction device  160  according to the present invention in an engine compartment  165  of an automobile  166 . The layout shown in FIG. 57 represents the case where a V-type internal combustion engine is longitudinally mounted. In this case, since the suction device  160  is mounted between left and right banks  163  and  164  of the V-type internal combustion engine, the side spaces between the engine and tires  167  are free and available, so that other parts can be easily mounted in these spaces and maintenance on such parts can be easily carried out. On the other hand, the layout shown in FIG. 58 represents the case where the V-type internal combustion engine is transversely mounted. In this case, since the suction device  160  is mounted between the left and right banks  163  and  164  of the engine, a partition  169  between the engine compartment  165  and the passenger compartment  168  can be shifted frontward in the automobile  166 . That is, the space of the engine compartment  165  can be reduced to thereby enlarge the space available in the passenger compartment  168 . In this manner, various advantages can be obtained owing to the compact design of the suction device  160 . 
     According to the present invention, the suction device including parts extending from the air cleaner to the suction ports, is compact, so that the space available in the engine compartment can be effectively used in such a manner that an additional mounting space for other parts can be provided, maintenance can be easily carried out, and the passenger space can be enlarged.