JP6260184B2 - Internal combustion engine supercharging system - Google Patents

Description

  The present invention relates to a supercharging system in an intake system suitable for application to an engine of a vehicle such as a motorcycle.

  In a vehicle such as a motorcycle, in order to improve the fuel consumption and output of an engine that is an internal combustion engine, a combination of engine displacement reduction and turbocharger is used, that is, engine displacement is reduced and intake efficiency by the turbocharger is used. May be improved at the same time.

  When a supercharger is used, the air pressurized by the supercharger becomes high temperature, and as a result, the intake efficiency decreases. An intercooler is added to cool the intake air without sacrificing intake efficiency. Thus, when using a supercharger, an intercooler is usually used together.

JP 2010-163891 A

As described above, in an engine that uses both a supercharger and an intercooler, efficient cooling of intake air by the intercooler and effective component arrangement and piping for reducing turbo lag (response delay) are required. The Conventionally, it has not been easy for motorcycles or the like to meet this type of request within a limited space.
Patent Document 1 discloses a structure in which a throttle body, an intercooler, and an air cleaner are arranged in the order from the cylinder head of the engine in the order between the seat rails.

  Especially when accelerating suddenly, it is necessary to inhale a large amount of air, and if the intercooler's ventilation resistance is large, the pressure in the surge tank placed in the immediate vicinity will drop, and this will affect the proper fuel injection by the injector. I get out. In such a case, the actual situation is that there is no auxiliary device for supplementing the intake air amount. Thus, it has been extremely difficult for conventional internal combustion engines to cope with an abrupt throttle operation.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a supercharging system for an internal combustion engine that can effectively cope with a rapid throttle operation and the like.

The supercharging system for an internal combustion engine of the present invention includes a supercharger that compresses intake combustion air, an intercooler for cooling the air compressed by the supercharger, and air from the intercooler. An internal combustion engine supercharging system comprising a surge tank that flows to a throttle body, one end connected to an intermediate portion of a connecting pipe connecting the supercharger and the intercooler, and the other end connected to the surge tank or the intercooler. A bypass pipe connected to an intermediate portion of an intercooler outlet pipe connecting the cooler and the surge tank, and having a control valve for controlling opening and closing of the bypass pipe at an appropriate position in the middle of the bypass pipe , connected to the throttle body A second surge tank that is separate from the surge tank, and the second surge tank is provided on the connecting pipe. It is characterized by Rukoto.

  In the supercharging system for an internal combustion engine according to the present invention, a third surge tank directly connected to the surge tank is provided.

  The supercharging system for an internal combustion engine according to the present invention is characterized by comprising a second pressure accumulator connected directly to the surge tank.

  The supercharging system for an internal combustion engine according to the present invention is characterized by being applied to an intake system of an engine of a motorcycle.

  According to the present invention, particularly when the throttle is suddenly opened, the intake air can be immediately supplied into the surge tank via the bypass pipe, and deficiency of the intake air can be suppressed. In particular, when applied to a motorcycle or the like in which the throttle operation significantly affects the stability of the vehicle body, an output characteristic closer to the occupant's intention can be obtained, so that the operability and riding comfort of the vehicle are improved.

1 is a side view of a motorcycle according to an embodiment of the present invention. 1 is a front perspective view of a motorcycle according to an embodiment of the present invention. 1 is a rear perspective view of a motorcycle according to an embodiment of the present invention. It is a side view around an engine unit according to an embodiment of the present invention. It is a top view around the engine unit according to the embodiment of the present invention. It is a bottom view around the engine unit according to the embodiment of the present invention. It is a perspective view which shows the surroundings of the intake system of the engine unit which concerns on embodiment of this invention. 1 is a left side view of an engine including an intake system and the like according to an embodiment of the present invention. 1 is a right side view of an engine including an intake system and the like according to an embodiment of the present invention. 1 is a top view of an engine including an intake system and the like according to an embodiment of the present invention. It is a figure which shows typically the distribution | circulation route of the intake air in the intake system which concerns on embodiment of this invention. It is a perspective view which shows the intercooler which concerns on embodiment of this invention. It is a perspective view which shows the main structures of the supercharging system of the internal combustion engine of this invention. 1 is a schematic diagram showing a main configuration of a supercharging system for an internal combustion engine according to the present invention. It is a perspective view which shows the main structures of the modification in the supercharging system of the internal combustion engine of this invention. FIG. 7 is a schematic diagram showing a main configuration of a modification of the supercharging system for the internal combustion engine of the present invention.

Hereinafter, preferred embodiments of a supercharging system for an internal combustion engine according to the present invention will be described with reference to the drawings.
1 to 3 show a schematic configuration of a motorcycle 100 as an application example of the present invention. FIG. 1 is a side view, FIG. 2 is a front perspective view, and FIG. 3 is a rear perspective view. First, the overall configuration of the motorcycle 100 will be described with reference to these drawings. In the drawings used in the following description, including FIGS. 1 to 3, the front of the vehicle is indicated by an arrow Fr, the rear of the vehicle is indicated by an arrow Rr, and the lateral right side of the vehicle is indicated by an arrow R as necessary. Thus, the left side of the vehicle is indicated by an arrow L.

  In FIG. 1 to FIG. 3, two front forks 103 are provided at the front of a vehicle body frame 101 (main frame) made of steel or aluminum alloy so as to be turnable left and right by a steering head pipe 102. It is done. A handle bar 104 is fixed to the upper end of the front fork 103 via a steering bracket 105. A front wheel 106 is rotatably supported on the lower portion of the front fork 103, and a front fender 107 is fixed so as to cover the upper portion of the front wheel 106.

  The vehicle body frame 101 is integrally coupled to the rear portion of the steering head pipe 102, branches in a bifurcated pair of left and right sides toward the rear, and extends while being widened rearward and downward from the steering head pipe 102. In this example, it may be a so-called twin spar type frame that is adopted as suitable for a vehicle or the like that requires high speed performance. Although not shown, the seat rail extends rearward from the vicinity of the rear portion of the vehicle body frame 101 with a moderate amount of rearward rise, and supports the seat 108 (seat seat). The vehicle body frame 101 has a three-dimensional structure in which the vehicle body frame 101 is bent or bent downward in the vicinity of the rear end portion thereof, the left and right sides are coupled to each other at the lower end thereof, and a space is formed inside as a whole.

  A swing arm 110 is coupled to the vicinity of the rear end of the body frame 101 via a pivot shaft 109 so as to be swingable in the vertical direction. A rear wheel 111 is rotatably supported at the rear end of the swing arm 110. In this example, the rear wheel 111 is cantilevered on the rear side of the swing arm 110. A rear shock absorber 112 is mounted between the vehicle body frame 101 and the swing arm 110. In particular, the lower end side of the rear shock absorber 112 is connected to both the vehicle body frame 101 and the swing arm 110 via a link mechanism 113. . A driven sprocket 114 around which a chain 118 that transmits engine power, which will be described later, is wound is attached to the rear wheel 111, and the rear wheel 111 is rotationally driven through the driven sprocket 114. A rear fender 115 that covers the vicinity of the front upper portion is provided in the immediate vicinity of the rear wheel 111.

  In the exterior of the vehicle, although not shown in detail, the front part and the left and right side parts of the vehicle are mainly covered by a cowling or a side cowl. In addition, a seat cover or a seat cowl 116 is attached around the seat 108 at the rear portion of the vehicle, and a so-called streamlined vehicle exterior form is formed by these exterior members. A fuel tank 117 is mounted on the front side of the seat 108.

  The engine unit 10 is mounted substantially in the center of the motorcycle 100. 4 to 6, the engine unit 10 includes an engine 11, and a water-cooled multi-cylinder four-cycle gasoline engine is used in the present embodiment. The engine 11 is a parallel two-cylinder engine in which # 1 and # 2 cylinders are arranged side by side in the left and right (vehicle width direction). A cylinder 13 and a cylinder head are disposed above a crankcase 12 that houses a crankshaft supported horizontally on the left and right. 14 and the cylinder head cover 15 are integrally coupled so as to overlap one another (FIG. 4), and an oil pan 16 is attached to the lowermost part. In addition, the cylinder axis line of the engine 11 is arranged to be inclined moderately forward. The engine 11 is suspended and coupled to the vehicle body frame 101 via a plurality of engine mounts so as to be integrally coupled and supported on the inside of the vehicle body frame 101, and acts as a rigid member of the vehicle body frame 101 by itself.

  A transmission case 17 is coupled to the rear portion of the crankcase 12, and a countershaft and a plurality of transmission gears (not shown) are disposed in the transmission case 17. The power of the engine unit 10 is finally transmitted from the crankshaft through a transmission to a drive sprocket 18 (see FIG. 4 and the like) which is an output end of the engine unit 10, and the drive sprocket 18 transmits a power transmission chain 118 (see FIG. 1). The driven sprocket 114, and thus the rear wheel 111, is driven to rotate.

  Note that the crankcase 12 and the transmission case 17 are integrally coupled to each other and constitute a casing assembly of the engine unit 10 as a whole. A plurality of auxiliary machines including a starter motor for starting the engine, a clutch device, and the like are mounted or coupled at appropriate positions of the casing assembly, and the entire engine unit 10 including these is supported by the vehicle body frame 101.

  The engine 11 further includes an intake system that supplies air (intake air) and an air-fuel mixture supplied from an air cleaner and a fuel supply device (which will be described later), and exhaust gas after combustion is supplied to the engine 11. An exhaust system exhausted from the engine, a cooling system that cools the engine 11, a lubrication system that lubricates the movable part of the engine 11, and a control system (ECU; Engine Control Unit) that controls the operation thereof are attached. A plurality of functional systems cooperate with the above-mentioned auxiliary machines and the like by the control of the control system, whereby the engine unit 10 as a whole is smoothly operated.

  More specifically, first, an intake port 19 (intake port; see FIG. 4) is opened on the rear side of the cylinder head 14 in both the # 1 and # 2 cylinders in the intake system, and an intake pipe 21 (intake pipe) is formed in the intake port 19. ) Is connected to the throttle body 20. The throttle body 20 is provided with a throttle valve (not shown) that opens and closes an intake passage formed in the throttle body 20 in accordance with the accelerator opening, and controls the flow rate of air supplied from an air cleaner, which will be described later. Is done. In this example, the throttle valve shafts of # 1 and # 2 cylinders are arranged coaxially, and have a valve drive mechanism 22 that drives them mechanically, electrically or electromagnetically. On the other hand, each throttle body 20 is provided with an injector 23 for fuel injection downstream of the throttle valve, and the fuel in the fuel tank 117 is supplied to these injectors 23 by a fuel pump. In this case, each injector 23 is connected to a delivery pipe 24 laid horizontally in the vehicle width direction on the upper side, and fuel is distributed from the delivery pipe 24 connected to the fuel pump. Each injector 23 injects fuel into the intake passage in the throttle body 20 at a predetermined timing under the control of the control system, whereby a mixture of a predetermined air-fuel ratio is supplied to the cylinders 13 of the # 1 and # 2 cylinders.

  Here, as shown in FIG. 4 or FIG. 6, the air cleaner 26 is provided at a predetermined interval below the magneto chamber 25 provided at the lower part of the engine 11, that is, on the left side of the crankcase 12 and on the left side of the oil pan 16. (Abbreviated by an alternate long and short dash line in FIG. 4 etc.) are arranged adjacent to each other. The air cleaner 26 is provided with an air filter in a box-shaped casing, and the air taken in the casing is cleaned by the air filter. An air outlet for purified air is opened in the front portion of the casing of the air cleaner 26, and an air supply pipe 27 is connected to the outlet. The air supply pipe 27 extends from the air cleaner 26, wraps around the front of the crankcase 12 as shown in FIG. 4, then curves upward, and further passes through the left side of the cylinder 13 and is air-cooled in this example. Connected to the intercooler 28.

  The intercooler 28 cools the air supplied from the air supply pipe 27, and the cooled air is supplied to the throttle bodies 20 of the # 1 and # 2 cylinders via the surge tank 29. . In this example, a supercharger 30 (turbocharger) is provided in the middle of the air supply pipe 27, that is, on the front side of the engine 11, and compresses the sucked air. Specific configurations of the intercooler 28 and the supercharger 30 will be described later.

  Next, in the exhaust system, an exhaust port 31 (exhaust port; see FIG. 4) is opened on the front side of the cylinder head 14 for both the # 1 and # 2 cylinders, and an exhaust pipe 32 (exhaust pipe) is connected to the exhaust port 31. The The exhaust pipe 32 of each cylinder temporarily extends downward from the exhaust port 31, merges and integrates at the front side of the cylinder 13, and then goes around the lower right part of the crankcase 12 and further extends rearward. A muffler (silencer) is attached to the rear end of the exhaust pipe 32. In this example, the drive unit side of the supercharger 30, that is, a turbine is arranged in the middle of the exhaust pipe 32, and a compressor that is rotationally driven by this turbine is arranged in the middle of the air supply pipe 27. Thus, in the present embodiment, a turbocharger that uses the exhaust flow of the engine 11 to pressurize the air sucked from the air cleaner 26 and supply the air to the intercooler 28 is employed.

  Although not shown in detail in the cooling system, a water jacket is formed around the cylinder block including the cylinder 13 so that the cooling water circulates, and the cooling water supplied to the water jacket is formed. It is equipped with a radiator 33 for cooling. The radiator 33 is supported at an appropriate position of the front of the engine unit 10 by using the body frame 101 or the like.

  Furthermore, a lubricating system for supplying lubricating oil to the movable parts of the engine unit 10 and lubricating them is configured. Although not shown in detail in the same manner, this lubrication system includes a valve operating device configured in the crankshaft and the cylinder head 14, a cam chain, a transmission, and the like that connect them. In this embodiment, a normal oil pump is used for the lubrication system, and the oil sucked from the oil pan 16 by this oil pump is fed to the lubrication system.

  Next, the basic configuration of the supercharging system of the engine unit 10 of the present invention, particularly in the intake system, will be further described. As shown in FIG. 7, the throttle body 20 and the surge tank 29 are disposed behind the cylinder head 14. The intercooler 28 is located behind the cylinder head 14 and the throttle body 20 and is disposed adjacent to the surge tank 29. The supercharger 30 is provided in front of the intercooler 28.

  FIG. 8 is a left side view of the engine 11 including the periphery of the intake system, FIG. 9 is a right side view thereof, and FIG. 10 is a top view thereof. In this example, the intercooler 28 has a thin box shape that is inclined so that the front side is appropriately lowered, and the longitudinal direction of the intercooler 28 extends in the longitudinal direction of the vehicle body. An air supply pipe 27 is connected to the box-shaped front end face of the intercooler 28 from the front. Referring to FIG. 1, the intercooler 28 is disposed below the seat 108, and at least a part (near the rear portion) is positioned rearward with respect to the front end of the seat 108 in a plan view of the vehicle body.

  The box-shaped upper surface of the intercooler 28 is defined as a wind receiving surface 28A, and the lower surface thereof is defined as a heat radiating surface 28B. By inclining the intercooler 28 and directing the air receiving surface 28A diagonally forward, it is possible to reduce the bending on the path from the introduction of the cooling air to the discharge, compared to the case where it is horizontally arranged without inclining, so that the intercooler 28 can be introduced from the front of the vehicle body. It is easy to receive the traveling wind, and the exhaust hot air that has passed through the intercooler 28 is easily flowed backward. Furthermore, the heat radiating surface 28B side of the lower surface of the intercooler 28 is disposed so as to face the space above the rear wheel 111 as shown in FIGS.

  FIG. 11 schematically shows air flow paths in the intake system. As described above, the air supply pipe 27 connected to the front end face of the intercooler 28 communicates with the interior of the intercooler 28, that is, the air inlet 28 a is disposed on the front side of the intercooler 28. A partition plate 34 is provided in the center of the interior of the intercooler 28 along the longitudinal direction. In this case, the partition plate 34 does not reach the rear end of the intercooler 28, so that the air flow path inside the intercooler 28 has a substantially U-shape. Become. In this example, a flow path is formed which flows from the front to the rear on the left side of the intercooler 28 and flows back from the rear end to the front from the rear on the right side of the intercooler 28. Further, an outlet pipe 35 is connected to the upper surface of the box-shaped front end portion of the intercooler 28, as shown in FIG. 12 and the like, that is, an air outlet 28b is arranged on the front side of the intercooler 28 in this case as well. Thus, in the intercooler 28 of this example, the air inlet 28a and the outlet 28b are set on one side.

  The surge tank 29 is arranged behind the cylinder head 14 as described above, but is connected to the outlet pipe 35 on the lower surface on the rear end side (see FIGS. 8 and 9). Further, in a plan view of FIG. 10 and the like, it is widened toward the throttle bodies 20 of the # 1 and # 2 cylinders to form a substantially triangular shape, and is connected to the throttle bodies 20 at the front end face. In this case, as shown in FIG. 8 or FIG. 9 or the like, a part (near the front) of the intercooler 28 is disposed so as to overlap the surge tank 29 in the vertical direction.

  Here, the basic operation of the supercharging system in the present invention will be described. First, by disposing the intercooler 28 adjacent to the surge tank 29, the air path between them can be shortened and the throttle response is improved. Moreover, since piping can be reduced, it leads to weight reduction and a reduction in the number of parts. Further, by arranging the intercooler 28 behind the engine 11, the layout on the front side of the engine 11 where the radiator 33, the exhaust pipe 32, and the supercharger 30 (mainly in the case of a turbo) are arranged can be facilitated. .

  Further, by disposing the supercharger 30 in front of the intercooler 28, the supercharger 30 is disposed in the vicinity of the engine 11, and the intake system parts can be concentrated, so that piping can be shortened and simplified. In addition, the operability of the vehicle is improved because the component weight is concentrated in the center of the vehicle body. In this example, a turbocharger 30 that is a so-called turbo that compresses intake air using an exhaust flow needs to be disposed in front of the engine 11 adjacent to an exhaust pipe 32 extending from the front side of the cylinder 13. By arranging the cooler 28 at the rear, the layout in front of the engine 11 is facilitated.

  Further, in the intercooler 28, the air inlet 28a and the outlet 28b are positioned on one side (the front half of the vehicle body), and the internal air flow path has a substantially U shape. Thus, by adopting a configuration in which the air flow path is folded back inside the intercooler 28, the intercooler 28 can be set wider than the conventional U-shaped pipe occupied as compared with the case where the folded U-shaped pipe is provided. As a result, the limited space or space below the seat 108 can be utilized to the maximum, so that the cooling efficiency of the intake air is improved and the number of parts can be reduced.

  Further, the intercooler 28 is located below the seat 108 and at least a part thereof is located behind the front end of the seat 108 in a plan view of the vehicle body. As a result, the intercooler 28 that generates high-temperature exhaust hot air is disposed below (directly below or behind) the seat 108, so that the exhaust hot air is less likely to hit the passenger as compared with the case where it is provided in front of the seat 108. Comfort is improved.

Further, the intercooler 28 is arranged in such a manner that the heat radiating surface 28B on one side faces the space above the rear wheel 111 (and below the seat 108). As a result, the intercooler 28 is disposed so as to be exposed in the space below the seat 108 at the rear of the vehicle body, so that the heat radiating surface 28B can easily cool the air by touching the outside air, and the exhausted air can be more easily removed. Superior to sex.
In addition, since a part of the intercooler 28 overlaps the surge tank 29 in the vertical direction, the air supply pipe 27 from the supercharger 30 can be further shortened by collecting and arranging the components. In this case, the weight of the component parts is concentrated at the center of the vehicle body, so that the operability of the vehicle is improved.

  Further, the intercooler 28 is arranged with its longitudinal direction extending in the longitudinal direction of the vehicle body. Thus, by arranging the intercooler 28 so that the air flow path is substantially straight with respect to the air supply pipe 27 extending in the front-rear direction from the supercharger 30 positioned in front, a resistance portion against the flow of air Reduced and better throttle response. In addition, in the motorcycle 100 or the like that is elongated in the front-rear direction, the passage path length can be secured by turning back the minimum path by extending the intercooler 28 forward and backward, and the cooling efficiency is excellent.

  Now, the supercharging system for an internal combustion engine according to the present invention has the basic structure as described above, and in particular, as shown in FIG. 13, one end of a connecting pipe 27A (air feed) connecting the supercharger 30 and the intercooler 28. A bypass pipe 36 connected to the middle portion of the pipe 27 and having the other end connected to the surge tank 29. More specifically, the other end of the bypass pipe 36 is connected to the side (left side) of the surge tank 29. Furthermore, a control valve 37 for controlling the opening and closing of the bypass pipe 36 is provided at an intermediate portion of the bypass pipe 36. In this case, the other end of the bypass pipe 36 may be connected to an intermediate portion of the outlet pipe 35 (see FIG. 12) that connects the intercooler 28 and the surge tank 29.

  Here, as described above, when the engine 11 is accelerated rapidly, a large amount of air needs to be sucked, and the intercooler 28 itself becomes a ventilation resistance as it is, and the pressure in the surge tank 29 decreases. Therefore, in the supercharging system of the present invention, in such a case, the control valve 37 is operated and the bypass pipe 36 is opened. The operation of the control valve 37 can be controlled to open according to the throttle operation, that is, when the throttle opening speed exceeds a predetermined speed, based on a signal from the throttle opening sensor or the like. Alternatively, the control valve 37 is opened according to the internal pressure of the surge tank 29, that is, when the internal pressure is lower than the predetermined internal pressure, so that the surge tank 29 passes through the bypass pipe 36 from the connection pipe 27A as shown by the dotted line in FIG. Air flows into. Thereafter, the operation is controlled so that the control valve 37 is closed after a predetermined time has elapsed and the internal pressure of the surge tank 29 has returned to a predetermined value. The closing operation of the control valve 37 is performed according to, for example, the elapsed time from the opening operation, the internal pressure measurement value of the surge tank 29, or the like.

  Thus, according to the state of the auxiliary device of the internal combustion engine, by opening the control valve 37 in a situation where the air in the surge tank 29 is suddenly sucked into the engine 11, for example, when the throttle is suddenly opened, The intake air can be immediately supplied into the surge tank 29 without going through the intercooler 28 having a relatively large ventilation resistance, and deficiency of the intake air can be suppressed. The same effect can be obtained when the other end of the bypass pipe 36 is connected to the outlet pipe 35.

  Furthermore, the supercharging system of the present invention includes a second surge tank 38 that is separate from the surge tank 29 connected to the throttle body 20. The second surge tank 38 is provided on the connecting pipe 27A as shown by a two-dot chain line in FIGS. More specifically, the second surge tank 38 is connected to the side of the cylinder 13 (the left side of the # 1 cylinder). In this case, one end of the bypass pipe 36 is connected to the second surge tank 38, and the bypass pipe 36 is opened and closed by the control valve 37 as described above. The second surge tank 38 is preferably disposed adjacent to the surge tank 29, and air can be supplied more quickly by arranging in this manner.

  In this example, the second surge tank 38 functions as a spare surge tank on the connection pipe 27A. That is, when the air is bypassed by the bypass pipe 36, the volume of the intake air that does not pass through the intercooler 28 can be secured in increments corresponding to the capacity of the second surge tank 38. Providing the second surge tank 38 not only simply bypasses the intercooler 28 via the bypass pipe 36 but also effectively suppresses the deficiency of the intake air in the main surge tank 29 when the throttle is suddenly opened. can do.

  Next, FIG.15 and FIG.16 has shown the modification of the supercharging system of this invention. In particular, a third surge tank 39 directly connected to the surge tank 29 is provided, and both are connected to each other via a connecting pipe 40. More specifically, the third surge tank 39 is disposed above the surge tank 29 as shown in FIG. The basic configuration of this example may be the same as that of FIG. 13, for example, the bypass pipe 36 is opened and closed by the control valve 37, and the second surge tank 38 is provided on the connection pipe 27A. On the other hand, the bypass pipe 36 and the second surge tank 38 are not necessarily used together, that is, an embodiment using only the bypass pipe 36 is also possible.

  In this example, by providing the third surge tank 39, an effect equivalent to substantially increasing the capacity of the surge tank 29 can be obtained. That is, in addition to efficiently supplying air by the bypass pipe 36, deficiency of intake air in the surge tank 29 at the time of sudden opening of the throttle can be effectively suppressed.

  In a further modification of the supercharging system of the present invention, either or both of the second surge tank 38 and the third surge tank 39 are replaced in the middle of the intake system including the connecting pipe 27A to the surge tank 29 described above. The accumulator is a pressure accumulator. Although illustration of this accumulator is omitted, a normal one can be used. That is, the accumulator has a pressure-accumulated gas sealed in a rubber film or the like, and in this example, the intake air supplied by the connecting pipe 27A. Is temporarily stored in an accumulator casing. Then, when the pressure of the intake air outside the accumulator casing decreases, the intake air accumulated in the accumulator casing is pushed out and released. Thus, the pressure accumulator operates to maintain the pressure of the gas in the above-described intake system, particularly in the surge tank 29.

  Specifically, an accumulator is provided on the connection pipe 27 </ b> A instead of the second surge tank 38, and this accumulator is made to cooperate with the bypass pipe 36. In this way, by providing an accumulator, which is a pressure accumulator capable of holding the intake air at a high pressure, on the connecting pipe 27A, a part of the intake air is stored in the accumulator during normal travel, and the air is released during bypass. As a result, the pressure drop in the surge tank 29 during the sudden opening of the throttle can be suppressed.

  Further, instead of the third surge tank 39, another accumulator (second pressure accumulator) connected directly to the surge tank 29 may be provided. Also in this case, by providing an accumulator as a second pressure accumulator, an effect equivalent to substantially increasing the capacity of the surge tank 29 can be obtained, and the intake air in the surge tank 29 at the time of sudden opening of the throttle can be obtained. The deficiency can be effectively suppressed.

  As described above, according to the present invention, the intake air can be immediately supplied into the surge tank 29 by opening the control valve 37 in accordance with the state of the auxiliary device of the internal combustion engine, including the case of sudden opening of the throttle. The lack of air can be suppressed, and the mixed state of fuel and intake air can be optimized. In particular, when applied to a vehicle in which the throttle operation significantly affects the stability of the vehicle body, such as a motorcycle, an output characteristic closer to the occupant's intention can be obtained, thereby improving the operability and ride comfort of the vehicle.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
The configuration of the present invention is not limited to the “motorcycle” itself, but may be applied to a vehicle such as a straddle-type vehicle (such as a three-wheeled scooter or an ATV), a snowmobile, or a marine jet. Like the motorcycle, these are vehicles in which the throttle operation significantly affects the stability of the vehicle body, and by applying the present invention, it is possible to expect a special improvement in operability and riding comfort.
In the above embodiment, the example of the water-cooled parallel two-cylinder engine has been described. However, the number of cylinders and the cooling method of the engine 11 can be selected as appropriate, and can be applied to an air-cooled engine having three or more cylinders, for example. is there.

10 Engine Unit, 11 Engine, 12 Crankcase, 13 Cylinder, 14 Cylinder Head, 16 Oil Pan, 17 Transmission Case, 18 Drive Sprocket, 19 Inlet, 20 Throttle Body, 21 Intake Pipe, 22 Valve Drive Mechanism, 23 Injector, 24 Delivery pipe, 25 Magnet chamber, 26 Air cleaner, 27 Air supply pipe, 27A Connecting pipe, 28 Intercooler, 29 Surge tank, 30 Supercharger, 31 Exhaust port, 32 Exhaust pipe, 33 Radiator, 34 Partition plate, 35 Outlet pipe, 36 bypass pipe, 37 control valve, 38 second surge tank, 39 third surge tank, 40 connecting pipe, 100 motorcycle.

Claims (6)

An internal combustion engine comprising a supercharger for compressing the intake combustion air, an intercooler for cooling the air compressed by the supercharger, and a surge tank for flowing air from the intercooler to the throttle body The supercharging system of
One end is connected to an intermediate portion of a connecting pipe connecting the supercharger and the intercooler, and the other end is connected to an intermediate portion of the surge tank or the intercooler outlet pipe connecting the intercooler and the surge tank. Have a bypass pipe,
A control valve for controlling the opening and closing of the bypass pipe at an appropriate position in the middle of the bypass pipe ;
Wherein with said second surge tank is separate from the surge tank connected to the throttle body, the second internal combustion engine supercharging system surge tank, characterized in Rukoto provided on the connecting pipe. An internal combustion engine comprising a supercharger for compressing the intake combustion air, an intercooler for cooling the air compressed by the supercharger, and a surge tank for flowing air from the intercooler to the throttle body The supercharging system of
One end is connected to an intermediate portion of a connecting pipe connecting the supercharger and the intercooler, and the other end is connected to an intermediate portion of the surge tank or the intercooler outlet pipe connecting the intercooler and the surge tank. Have a bypass pipe,
A control valve for controlling the opening and closing of the bypass pipe at an appropriate position in the middle of the bypass pipe;
A supercharging system for an internal combustion engine, comprising: a pressure accumulating device that operates so as to hold the pressure of the pressure accumulating gas, wherein the pressure accumulating device is provided on the connecting pipe. The pressure accumulator can hold the intake air at a high pressure and operates to maintain the pressure of the gas in the surge tank;
3. The pressure reduction in the surge tank is suppressed when the throttle is suddenly opened by storing a part of the intake air in the pressure accumulator during normal driving and releasing the air during bypass. A supercharging system for an internal combustion engine as described. The supercharging system for an internal combustion engine according to claim 1 , further comprising a third surge tank directly connected to the surge tank. The supercharging system for an internal combustion engine according to claim 2 or 3, further comprising a second pressure accumulator connected directly to the surge tank.   The supercharging system for an internal combustion engine according to any one of claims 1 to 5, wherein the supercharging system is applied to an intake system of an engine of a motorcycle.

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