JP5937863B2 - engine - Google Patents

Description

  The present invention relates to an engine having two superchargers.

  2. Description of the Related Art Conventionally, a configuration (two-stage supercharging system) including two superchargers is known for engines such as cars and ships. In the two-stage supercharging system, the exhaust gas discharged from the cylinder is used to rotate the turbine of the first supercharger, so that the air is compressed and sent to the cylinder side. The second supercharger further compresses the air compressed by the first supercharger and then sends the air to the cylinder. Thereby, since the flow volume of the air supplied to a cylinder can be increased, the output of an engine can be improved. In the two-stage supercharger system, air is supplied as described above.

  On the other hand, the exhaust gas discharged from the cylinder is first sent to the second supercharger. Moreover, said two superchargers are mutually connected by the supercharger connection pipe. The exhaust gas used by the second supercharger is supplied to the first supercharger through the supercharger connecting pipe. Patent Documents 1 to 3 disclose this type of two-stage supercharging system. Patent Documents 1 to 3 disclose automobile engines, engines for construction machines such as power shovels, aircraft engines, and the like as objects to which the two-stage turbocharger system is applied.

JP 2011-99332 A JP 2011-163001 A Japanese Patent No. 3953636

  By the way, in this two-stage supercharging system, in order to ensure the low speed torque of the engine, a configuration in which the second supercharger is usually made small is employed. However, the small turbocharger has a significant increase in the rotational speed of the turbine when exhaust gas is supplied, compared to the large supercharger. Further, the second supercharger also has an influence that exhaust gas is supplied first, and the rotational speed of the turbine is likely to increase as compared with the first supercharger.

  Therefore, when the second supercharger is downsized, the rotational speed of the turbine may exceed the allowable rotational speed. This is a large load on the second supercharger, so it is considered that the second supercharger is damaged or the life is shortened. However, if the size of the second supercharger is increased, it becomes impossible to ensure the low speed torque of the engine.

  The present invention has been made in view of the above circumstances, and its main purpose is that the turbocharger reaches an allowable rotational speed without increasing the size of the supercharger to which exhaust gas is first supplied. It is an object of the present invention to provide an engine having a configuration that prevents the above.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

According to an aspect of the present invention, an engine having the following configuration is provided. That is, the engine includes an exhaust manifold, a front-stage supercharger, a supercharger connecting pipe, a rear-stage supercharger, a bypass pipe, a delivery amount valve, and a first intercooler . The exhaust manifold collects exhaust gases discharged from a plurality of cylinders. The front-stage supercharger includes a compressor and a turbine, is connected to the exhaust manifold, and supplies air using exhaust gas sent from the exhaust manifold. The supercharger connecting pipe is connected to the front-stage supercharger, and exhaust gas used by the front-stage supercharger flows. The latter-stage supercharger includes a compressor and a turbine, and performs air supply using exhaust gas sent from the supercharger connecting pipe. The bypass pipe connects the exhaust manifold and the supercharger connecting pipe, and sends the exhaust gas supplied from the exhaust manifold to the supercharger connecting pipe without being divided. The delivery amount valve is attached to the bypass pipe and adjusts the amount of exhaust gas delivered to the supercharger connection pipe. The first intercooler is disposed between the front-stage supercharger and the rear-stage supercharger, and cools the air taken into the rear-stage supercharger. When the longitudinal direction of the crankshaft is the crankshaft direction and the direction perpendicular to both the crankshaft direction and the height direction is the apparatus width direction, the compressor and the turbine of the front turbocharger are in the crankshaft direction. The compressor and the turbine of the rear-stage supercharger are arranged side by side in the apparatus width axis direction, and the longitudinal direction of the turbocharger connecting pipe is the same as the crankshaft direction.

Thereby, it is possible to prevent the exhaust gas exceeding the allowable amount from being sent to the upstream turbocharger by adjusting the delivery amount valve. Therefore, it is possible to reduce the load applied to the preceding supercharger. Moreover, since the front-stage supercharger can be reduced in size, a low-speed torque can be sufficiently ensured. The front-stage supercharger is arranged at one end in the apparatus width direction, the rear-stage supercharger is arranged at one end in the crankshaft direction, and the turbine of the rear-stage supercharger turbine and compressor is the front-stage supercharger in the apparatus width direction. More preferably, it is arranged on the side where the feeder is arranged .

  In the engine, it is preferable that the delivery amount valve is attached to the supercharger connecting pipe side from the center of the bypass pipe.

  As a result, the temperature of the exhaust gas that touches the delivery valve can be lowered slightly, so that the delivery valve can be prevented from sticking without cooling (or not at all) the delivery valve.

  The engine preferably has the following configuration. That is, the exhaust manifold is formed with at least an exhaust port for connecting to the front-stage supercharger and an exhaust port for connecting to the bypass pipe. The direction indicated by the phantom line connecting both the exhaust ports and the longitudinal direction of the supercharger connecting pipe are the same direction.

  As a result, a rational layout in which the supercharger connecting pipe follows the exhaust manifold can be realized. Further, in this layout, the bypass pipe can be shortened, so that it is possible to suppress the energy loss of the exhaust gas sent to the rear-stage supercharger.

  In the engine, it is preferable that the exhaust manifold and the supercharger connecting pipe are arranged at the same height.

  Thereby, since a bypass pipe | tube can be shortened further, the energy loss of the exhaust gas sent to a back | latter stage supercharger can further be suppressed.

1 is a perspective view of a marine engine according to an embodiment of the present invention. The top view of a marine engine. The front view of a marine engine. The perspective view which shows a mode that exhaust gas is supplied to a supercharger. The route diagram showing an air supply route and an exhaust route. The top view which shows a mode that exhaust gas is supplied to a supercharger. The perspective view which shows the positional relationship of the apparatus of an air supply system.

  Next, embodiments of the present invention will be described with reference to the drawings. First, the overall configuration of the marine engine 1 will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view of a marine engine 1 according to an embodiment of the present invention. FIG. 2 is a plan view of the marine engine 1. FIG. 3 is a front view of the marine engine 1. FIG. 4 is a perspective view showing how exhaust gas is supplied to the supercharger.

  In the following description, as shown in FIG. 1, the vertical direction of the marine engine (engine) 1 is referred to as the height direction, and the longitudinal direction of the crankshaft 61 (see FIG. 2) of the marine engine 1 is the crankshaft direction. A direction perpendicular to both the height direction and the crankshaft direction is referred to as a device width direction. Further, the upper side in FIG. 1 (the side on which the top cover 10 is disposed) in the height direction is defined as the upper side.

  The marine engine 1 of this embodiment is an inboard type diesel engine mounted on a vessel such as a pleasure boat. Further, the marine engine 1 employs a two-stage supercharging system.

  The marine engine 1 includes a top cover 10 as shown in FIG. The top cover 10 is configured in a flat plate shape, and is arranged so that the thickness direction coincides with the height direction. The top cover 10 is not limited to a flat plate shape, and may have a configuration in which bending (or bending) is formed at least partially. A valve cover, a cylinder block, and the like are disposed below the top cover 10.

  The marine engine 1 includes a first supercharger (second-stage supercharger) 22, a first intercooler 23, a second supercharger (front-stage supercharger) 24, and a second intercharger as a two-stage supercharging system. The cooler 25 and the supply pipes 21a-21d which connect them are provided.

  The first supercharger 22 includes a turbine and a compressor inside the housing. The turbine is configured to rotate using exhaust gas. The compressor is connected to the same shaft as the turbine and rotates as the turbine rotates. The 1st supercharger 22 can compress air and can supply air compulsorily, when a compressor rotates. With this configuration, the flow rate of the air supplied to the cylinder using the exhaust gas can be increased, so that the output of the marine engine 1 can be increased. In addition, since air is rapidly compressed by inhaling by the 1st supercharger 22, the said air becomes high temperature. This high-temperature air is sent to the first intercooler 23 through the air supply pipe 21a.

  A plurality of cooling pipes through which seawater flows are arranged inside the housing of the first intercooler 23. The air sent from the first supercharger 22 is configured to flow around the cooling pipe. With this configuration, the first intercooler 23 can cool the air sent from the first supercharger 22 by heat exchange with seawater. The air cooled by the first intercooler 23 is sent to the second supercharger 24 through the air supply pipe 21b.

  The 2nd supercharger 24 is the structure equivalent to the 1st supercharger 22, and as shown in FIG. 4, it has the turbine housing 24a in which the turbine was incorporated, and the compressor housing 24b in which the compressor was incorporated. . The second supercharger 24 can compress the air sent from the first intercooler 23. This compressed air becomes high temperature as described above. Then, this high-temperature air is sent to the second intercooler 25 through the air supply pipe 21c. In addition, the detail of the structure by which exhaust gas is supplied to the 1st supercharger 22 and the 2nd supercharger 24 is mentioned later.

  The 2nd intercooler 25 is the structure equivalent to the 1st intercooler 23, and cools the air sent out from the 2nd supercharger 24 by heat exchange with seawater. The air cooled by the second intercooler 25 is sent to the air supply manifold 28 via the air supply pipe 21d.

  A common rail type fuel injection mechanism is disposed in the cylinder head inside the top cover 10. The marine engine 1 further compresses the compressed air supplied to the cylinder, and then drives the piston up and down by injecting fuel by the fuel injection mechanism. Thereby, the marine engine 1 can generate motive power.

  The marine engine 1 includes a flywheel housing 62, an oil pan 63, and an oil filter 26, as shown in FIG.

  The flywheel housing 62 is disposed at an end portion on the first supercharger 22 side in the crankshaft direction. A transmission 75 is connected to the flywheel in the flywheel housing 62 via a clutch (not shown). A marine propulsion device or the like is connected to the transmission 75. Thereby, the output of the marine engine 1 can be transmitted to the propulsion device or the like, or shut off.

  The oil pan 63 is disposed on the surface (bottom surface) opposite to the top cover 10 in the height direction. The oil pan 63 is a member for accumulating engine oil supplied to the inside of the engine (main movement system parts such as a cylinder). The engine oil stored in the oil pan 63 is sent into the engine by an unillustrated oil pump.

  The engine oil delivered by the oil pump passes through the oil filter 26. Thereby, metal powder, dust, etc. contained in engine oil can be removed. In the present embodiment, the oil filter 26 includes two filters (a full flow filter and a bypass filter).

  Next, with reference to FIG. 4 to FIG. 6, the flow of exhaust gas, in particular, the configuration for supplying exhaust gas to the first supercharger 22 and the second supercharger 24 will be described. FIG. 5 is a route diagram showing an air supply route and an exhaust route. FIG. 6 is a plan view showing how exhaust gas is supplied to the first supercharger 22 and the second supercharger 24.

  As shown in FIG. 5, the exhaust gas discharged from a plurality of (six in this embodiment) cylinders is collected into one or a plurality (one in this embodiment) by the exhaust manifold 71 and discharged from the exhaust port 72. Is done. The exhaust manifold 71 is disposed at the end portion on the second supercharger 24 side in the apparatus width direction (see FIG. 4 and the like). Hereinafter, the flow of the exhaust gas discharged from each exhaust port 72 will be described.

  As shown in FIG. 5, an EGR pipe 51 is connected to the exhaust port 72 on the second intercooler 25 side. The EGR pipe 51 is cooled by the EGR cooler 52 and then sent to the air supply manifold 28. An EGR valve 53 is attached to the EGR pipe 51, and the flow rate of the exhaust gas supplied to the air supply manifold 28 can be adjusted.

  The second supercharger 24 is connected to the central exhaust port 72. Thereby, exhaust gas can be supplied to the second supercharger 24. The exhaust gas that has rotated the turbine through the turbine housing 24 a of the second supercharger 24 is sent to the first supercharger 22 via the supercharger connecting pipe 41.

  As described above, the second supercharger 24 is preferably small in order to ensure low-speed torque. However, there is a possibility that a small supercharger may be damaged by exceeding an allowable rotational speed when a large amount of exhaust gas is supplied.

  In order to avoid this, a waste gate passage 46 that connects the exhaust manifold 71 and the supercharger connecting pipe 41 is disposed in the second supercharger 24 (see FIG. 5). Thereby, a part of the exhaust gas discharged from the exhaust manifold 71 can be sent to the first supercharger 22 without passing through the second supercharger 24. A valve 47 is attached to the wastegate passage 46. Thereby, the flow volume of the exhaust gas supplied to the turbine housing 24a of the 2nd supercharger 24 can be adjusted.

  In the present embodiment, as shown in FIG. 5, the waste gate passage 46 is disposed in the second supercharger 24. Thereby, the size of the wastegate passage 46 is restricted by the size of the second supercharger 24.

  Thus, by providing the wastegate passage 46, the amount of exhaust gas supplied to the turbine housing 24a can be reduced.

  However, even if the valve 47 is completely opened, depending on the amount of exhaust gas discharged from the exhaust manifold 71, excessive exhaust gas may flow into the turbine housing 24a. In this case, the second supercharger 24 may be damaged.

  In the present embodiment, in order to solve this problem, a bypass pipe 42 that connects the exhaust port 72 at the end on the first supercharger 22 side and the supercharger coupling pipe 41 is disposed (see FIG. 5). As a result, the exhaust gas discharged by the exhaust manifold 71 can be sent directly to the first supercharger 22 (without passing through the wastegate passage 46 and the second supercharger 24).

  In addition, a delivery amount valve 43 is attached to the bypass pipe 42. Thereby, the flow volume of the exhaust gas supplied to the 1st supercharger 22 can be adjusted. Further, the delivery amount valve 43 has a large capacity, and when it is completely opened, it is assumed that the entire amount of exhaust gas discharged from the cylinder can be discharged.

  Next, a layout for shortening the bypass pipe 42 will be described. The exhaust gas immediately after being discharged from the cylinder has high temperature and pressure and high energy. Therefore, by shortening the path from the cylinder to the supercharger, it is possible to suppress the energy loss of the exhaust gas and to operate the supercharger efficiently.

  Therefore, in the present embodiment, the following layout is adopted. That is, as shown in FIG. 6, in the present embodiment, the longitudinal direction of the exhaust manifold 71 coincides with the crankshaft direction. Accordingly, the exhaust ports 72 are formed side by side in the crankshaft direction. Therefore, the imaginary line L1 connecting the exhaust port 72 indicates the crankshaft direction.

  On the other hand, the first supercharger 22 and the second supercharger 24 are arranged side by side in the crankshaft direction. Therefore, the supercharger connecting pipe 41 that connects them is arranged so that the longitudinal direction is the crankshaft direction. From the above, the direction indicated by the imaginary line L1 connected to the exhaust port 72 and the longitudinal direction of the supercharger connecting pipe 41 coincide.

  Accordingly, the bypass pipe 42 can be shortened by bringing the supercharger connecting pipe 41 closer to the exhaust manifold 71. Moreover, in this embodiment, since the height of the supercharger connecting pipe 41 and the exhaust manifold 71 is equal, the bypass pipe 42 can be further shortened.

  Further, as shown in FIG. 6, the bypass pipe 42 is connected to the first supercharger 22 side from the center of the supercharger connecting pipe 41. By arranging the bypass pipe 42 in this way, the exhaust gas reaches the first supercharger 22 without flowing much through the supercharger connecting pipe 41. Therefore, loss of exhaust gas energy can be prevented.

  Next, the position of the delivery valve 43 and the cooling of the delivery valve 43 will be described.

  As described above, since the exhaust gas immediately after being exhausted from the exhaust manifold 71 is at a high temperature, the delivery amount valve 43 may be fixed depending on the use environment, material, and the like.

  In this respect, in the present embodiment, the temperature of the exhaust gas contacting the delivery amount valve 43 can be slightly lowered by disposing the delivery amount valve 43 from the supercharger connecting pipe 41. Specifically, as shown in FIG. 6, the delivery amount valve 43 is attached to the first supercharger 22 side from the center of the bypass pipe 42.

  Further, when the sticking cannot be prevented only by the position of the delivery amount valve 43, the sticking can be prevented by cooling with cooling water or the like. In particular, when the exhaust manifold 71 is water-cooled, the delivery valve 43 can be cooled with a simple configuration by flowing a part of the cooling water flowing through the exhaust manifold 71 to the periphery of the delivery valve 43. In particular, in this embodiment, since the length of the bypass pipe 42 is short, the delivery amount valve 43 can be cooled without making the length of the cooling pipe so long. At this time, it is preferable that only the delivery amount valve 43 is cooled without cooling the exhaust gas.

  As described above, the marine engine 1 of the present embodiment includes the exhaust manifold 71, the second supercharger 24, the supercharger connection pipe 41, the first supercharger 22, the bypass pipe 42, A delivery amount valve 43. The exhaust manifold 71 collects exhaust gases discharged from a plurality of cylinders. The second supercharger 24 is connected to the exhaust manifold 71 and supplies air using the exhaust gas sent from the exhaust manifold 71. The supercharger connection pipe 41 is connected to the second supercharger 24, and the exhaust gas used by the second supercharger 24 and the exhaust gas via the wastegate passage 46 flow therethrough. The first supercharger 22 supplies air using the exhaust gas sent from the supercharger connection pipe 41. The bypass pipe 42 connects the exhaust manifold 71 and the supercharger connection pipe 41 and sends the exhaust gas sent from the exhaust manifold 71 to the supercharger connection pipe 41 without being divided. The delivery amount valve 43 is attached to the bypass pipe 42 and adjusts the amount of exhaust gas delivered to the supercharger connection pipe 41.

  Thus, by adjusting the delivery amount valve 43, it is possible to prevent the exhaust gas exceeding the allowable amount from being sent to the second supercharger 24. Accordingly, the load applied to the second supercharger 24 can be reduced. Moreover, since the 2nd supercharger 24 can be reduced in size, low speed torque can fully be ensured.

  In the marine engine 1 of the present embodiment, the delivery amount valve 43 is attached to the supercharger connecting pipe 41 side from the center of the bypass pipe 42.

  As a result, the temperature of the exhaust gas that touches the delivery valve 43 can be lowered a little, so that the delivery valve 43 can be prevented from sticking without cooling the delivery valve 43 too much (or at all).

  In the marine engine 1 of the present embodiment, the direction indicated by the imaginary line L1 connecting the plurality of exhaust ports 72 and the longitudinal direction of the supercharger connecting pipe 41 are the same direction.

  Thereby, a rational layout in which the supercharger connecting pipe 41 is along the exhaust manifold 71 can be realized. Further, in this layout, since the bypass pipe 42 can be shortened, energy loss of the exhaust gas sent to the first supercharger 22 can be suppressed.

  Moreover, in the marine engine 1 of this embodiment, it arrange | positions so that the exhaust manifold 71 and the supercharger connection pipe 41 may become the same height.

  Thereby, since the bypass pipe 42 can be further shortened, the energy loss of the exhaust gas sent to the first supercharger 22 can be further suppressed.

  Next, the arrangement of the equipment and the oil filter 26 constituting the two-stage turbocharging system of the present embodiment will be described from various viewpoints. In the following description, the devices (the first supercharger 22, the first intercooler 23, the second supercharger 24, and the second intercooler 25) and the oil filter 26 that constitute the two-stage supercharging system are summarized. Are sometimes referred to as “superchargers”.

  First, with reference to the plan view (FIG. 2), the arrangement of the supercharger and the like in the plan view will be described. Since the thickness direction and the height direction of the top cover 10 coincide with each other as described above, the plan view in the present embodiment can also be referred to as “a view seen in the thickness direction of the top cover 10”.

  The first supercharger 22 is disposed at one end of the marine engine 1 in the crankshaft direction. The first intercooler 23, the second supercharger 24, and the second intercooler 25 are all disposed at one end of the marine engine 1 in the device width direction. These three devices are arranged side by side in the crankshaft direction so that the first intercooler 23 is close to the first supercharger 22. The oil filter 26 is disposed at the other end of the marine engine 1 in the crankshaft direction (the end opposite to the transmission 75 side).

  In addition, the superchargers and the like of the present embodiment are all arranged so as not to overlap each other. As a result, a worker who performs maintenance on the top cover 10 can perform maintenance without removing other devices, so that a layout with good workability is realized.

  Next, with reference to a front view (FIG. 3), the position in the height direction of the supercharger or the like will be described. In the present embodiment, the upper surface of the top cover 10 constitutes a part of the upper surface of the marine engine 1. The lower surface of the oil pan 63 constitutes a part of the lower surface of the marine engine 1. Therefore, the length from the lower surface of the oil pan 63 to the upper surface of the top cover 10 can be said to be the height of the marine engine 1. Hereinafter, as shown in FIG. 3, half of the height of the marine engine 1 is referred to as a “reference height”.

  At this time, all of the turbochargers and the like are arranged above the reference height (on the top cover 10 side). More specifically, not only the upper end of the supercharger or the like, but also the center and lower end thereof are arranged above the reference height. Further, the upper surfaces of the first supercharger 22, the first intercooler 23, and the second intercooler 25 are disposed so as to substantially coincide with the upper surface of the marine engine 1.

  With this configuration, since the supercharger and the like are located on the upper part of the marine engine 1, it is easy for an operator who performs maintenance on the top cover 10 to access the supercharger or the like (good workability). Layout is realized.

  Next, the lengths of the air supply pipes 21a to 21d are compared with reference to a perspective view (FIG. 7) showing the positional relationship of the air supply system devices.

  Here, the length of the air supply pipe 21a is the length of the air path from the first supercharger 22 to the first intercooler 23, and the same applies to the other air supply pipes. Therefore, in this embodiment, the length of the path | route of the air supplied to a cylinder can be compared by comparing the length of an air supply pipe | tube.

  In this embodiment, “the length of the air supply pipe 21a <the length of the air supply pipe 21b” is established, and “the length of the air supply pipe 21c <the length of the air supply pipe 21d” is established.

  With this configuration, the air supply pipe 21a and the air supply pipe 21c through which high-temperature air passes can be made relatively short. Therefore, since the part which needs to be covered with a heat insulating material etc. among the whole air supply pipe | tube can be shortened, cost can be reduced.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  The shapes and layouts of the parts constituting the marine engine 1 are examples and can be changed as appropriate. For example, the number of cylinders, the arrangement of the supercharger and the intercooler, and the like can be changed according to the required size and specifications.

  The object to which the present invention is applied may be either a marine main engine or an auxiliary machine. Moreover, it is not restricted to a ship, The engine for motor vehicles or work vehicles may be sufficient.

1 Marine Engine (Engine)
DESCRIPTION OF SYMBOLS 10 Top cover 11 Partition part 21a-21d Air supply pipe 22 1st supercharger (rear stage supercharger)
23 1st intercooler 24 2nd supercharger (front turbocharger)
25 Second intercooler 41 Supercharger connecting pipe 42 Bypass pipe 43 Delivery amount valve 71 Exhaust manifold 72 Exhaust port

Claims (5)

An exhaust manifold that collects exhaust gases discharged from a plurality of cylinders;
A pre-supercharger that includes a compressor and a turbine, is connected to the exhaust manifold, and supplies air using exhaust gas sent from the exhaust manifold;
A turbocharger connecting pipe connected to the upstream turbocharger, through which exhaust gas used by the upstream turbocharger flows;
A rear-stage supercharger that includes a compressor and a turbine and performs air supply using exhaust gas sent from the supercharger connecting pipe;
A bypass pipe that connects the exhaust manifold and the supercharger connecting pipe, and sends the exhaust gas supplied from the exhaust manifold to the supercharger connecting pipe without being divided;
A delivery amount valve that is attached to the bypass pipe and adjusts the amount of exhaust gas delivered to the turbocharger connection pipe;
A first intercooler that is disposed between the front-stage supercharger and the rear-stage supercharger and that cools air taken into the rear-stage supercharger;
With
When the longitudinal direction of the crankshaft is the crankshaft direction and the direction perpendicular to both the crankshaft direction and the height direction is the device width direction,
The compressor and the turbine of the front turbocharger are arranged side by side in the crankshaft direction,
The compressor and the turbine of the rear turbocharger are arranged side by side in the apparatus width axis direction,
The engine characterized in that a longitudinal direction of the supercharger connecting pipe is the same as the crankshaft direction. The engine according to claim 1,
The front-stage supercharger is disposed at one end in the apparatus width direction,
The rear turbocharger is disposed at one end in the crankshaft direction,
Of the turbine and the compressor of the rear-stage supercharger, the turbine is disposed on a side where the front-stage supercharger is disposed in the apparatus width direction. The engine according to claim 1 or 2 ,
The engine, wherein the delivery amount valve is attached to the supercharger connecting pipe side from the center of the bypass pipe. The engine according to any one of claims 1 to 3 ,
The exhaust manifold is formed with at least an exhaust port for connecting to the front-stage supercharger and an exhaust port for connecting to the bypass pipe,
An engine characterized in that a direction indicated by a virtual line connecting both the exhaust ports and a longitudinal direction of the supercharger connecting pipe are the same direction. The engine according to claim 4 ,
The engine, wherein the exhaust manifold and the supercharger connecting pipe are arranged at the same height.

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