JP2021041833A - Cooling structure of power generation unit for range extender vehicle - Google Patents

Abstract

To efficiently cool a power generation unit for a range extender vehicle which generates power by a power generation engine.SOLUTION: A power generation engine 20 includes: a cylinder case 22; and a first cooling fan 25. The cylinder case 22 is provided with an opening 22a for exhausting air. A muffler 50 has: a muffler body 51; and a cover member 53 formed by a heat shielding plate. The cover member 53 and the cylinder case 22 are connected by a communication passage component 40. Air taken by the first cooling fan 25 flows into the cover member 53 through the cylinder case 22 and the communication passage component 40 to be exhausted to the outside.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cooling structure of a power generation unit for a range extender vehicle.

As an electric vehicle driven by an electric motor, a vehicle equipped with a small generator is known. The small generator has, for example, a power generation engine, and the power generation engine can generate electric power to supply electric power to an electric vehicle. By supplying electric power to the electric motor of the electric vehicle, the small generator can extend the cruising range of the electric vehicle, for example. As such a small generator, for example, an apparatus disclosed in Patent Document 1 is known.

The small generator generates electricity by a power generation engine and has an inverter or the like. Further, a small generator requires a cooling structure for cooling an engine for power generation, an electric device such as the inverter, and the like.

Japanese Unexamined Patent Publication No. 2008-169114

Since a small generator like the above example generates heat by operating a power generation engine, it is necessary to reduce the size and efficiently dissipate heat. For example, a power generation engine generates a large amount of heat as compared with other devices constituting a small generator. Further, the muffler into which the exhaust gas exhausted from the power generation engine flows in also becomes hotter than other devices. Therefore, power generation engines and mufflers are required to have higher cooling performance than other devices.

However, in the structure shown in the above example, the space between the devices constituting the power generation unit is used as a cooling passage, and air is passed through the cooling passage to lower the ambient temperature. Therefore, a large amount of air flows into the space around the device that does not require high cooling performance (device with low calorific value), and the space around the device that requires high cooling performance (device with high calorific value). On the other hand, there is a possibility that the amount of air flow will decrease. Therefore, in the structure as in the above example, there is room for improvement in cooling a device having a large calorific value such as a power generation engine.

The present invention has been made to solve the above problems, and an object of the present invention is to be able to efficiently cool a power generation unit that generates power by a power generation engine, and in particular, to efficiently cool a power generation engine or the like. It is possible to provide a cooling structure for a power generation unit for a range extender vehicle.

The cooling structure of the power generation unit for a range extender vehicle according to the present invention for achieving the above object comprises a power generation engine that supplies electric power to the vehicle and a muffler through which exhaust gas emitted from the power generation engine flows. I have. In the cooling structure of the power generation unit for the range extender vehicle, the power generation engine has a cylinder case for accommodating a cylinder portion and a cooling fan for inflowing air into the cylinder case, and is provided on a wall portion of the cylinder case. Is provided with an opening for exhausting air in the cylinder case, and the muffler includes a muffler main body through which the exhaust gas flows, a cover member covering the muffler main body and formed by a heat shield plate. A connecting passage component is provided between the cover member and the cylinder case, and the air taken in by the cooling fan passes through the cylinder case and the connecting passage component of the cover member. It is configured to flow inside and be exhausted to the outside.

According to the present invention, it is possible to efficiently cool the power generation engine or the like of the power generation unit that generates power by the power generation engine.

It is a top view which shows one Embodiment of the cooling structure of the power generation unit for a range extender vehicle which concerns on this invention. It is a schematic perspective view which shows the member which comprises the 1st cooling system of FIG. It is a side view which looked at the power generation unit of FIG. 1 from the left side in the vehicle width direction. It is a perspective view which shows the state which removed the cylinder case and the like of FIG. It is a top view of the connecting passage component of FIG. 2 and its periphery. FIG. 5 is a rear view of the connecting passage parts and the like of FIG. 5 as viewed from the rear side of the vehicle. The first cooling passage is shown in the cross-sectional view taken along the line AA of FIG.

Hereinafter, an embodiment of the cooling structure of the power generation unit for a range extender vehicle according to the present invention will be described with reference to the drawings (FIGS. 1 to 7).

In the figure, the arrow Fr direction indicates the front in the vehicle front-rear direction. The "front (front end) and rear (rear end)" in the description of the embodiment correspond to the front and rear parts in the front-rear direction of the vehicle. Further, the arrows R and L indicate the right side and the left side in the vehicle width direction, respectively, and the "left and right" in the present embodiment correspond to the "left side" and the "right side" when the occupant faces the front of the vehicle. There is.

As shown in FIG. 1, the cooling structure of the range extender vehicle power generation unit 1 of the present embodiment has two cooling systems, that is, a first cooling system 11 and a second cooling system 12. .. First, the configuration of the power generation unit 1 will be described. The power generation unit 1 of the present embodiment includes a power generation engine 20, a fuel tank 30, a muffler 50, an inverter 35, and a generator 38 (power generation unit). Further, the power generation unit 1 is arranged in a region surrounded by a frame 2 having a substantially rectangular parallelepiped shape.

The generator 38 is connected to the right side of the power generation engine 20 in the vehicle width direction, and the power generation engine 20 drives to generate power. A radiator 39 and an inverter 35 are connected to the generator 38.

The fuel tank 30 is a tank filled with fuel for driving the power generation engine 20, and is arranged on the right side of the power generation engine 20 in the vehicle width direction as shown in FIG. A cap 30a for closing an opening (not shown) for refueling is attached to the upper wall surface 31 of the fuel tank 30.

As shown in FIG. 2, the muffler 50 is connected to the power generation engine 20 via a connecting pipe 28, which will be described later, and the exhaust gas released from the power generation engine 20 flows in through the connecting pipe 28. Release to the outside. The muffler 50 includes a muffler main body 51 and a cover member 53, and details of these will be described later.

As shown in FIGS. 1 and 7, the inverter 35 is a substantially rectangular parallelepiped device fixed to the upper part of the fuel tank 30 and extending in the front-rear direction of the vehicle, and is electrically connected to the generator 38. A plurality of heat radiation fins 36 are provided below the inverter 35. Each of the heat radiating fins 36 protrudes downward from the lower part of the inverter 35 and extends in the vehicle front-rear direction, and the plurality of heat radiating fins 36 are arranged at intervals in the vehicle width direction.

First, the details of the first cooling system 11 will be described. As shown in FIG. 2, the first cooling system 11 is configured such that cooling air flows from the power generation engine 20 toward the muffler 50. The first cooling system 11 includes a power generation engine 20, a muffler 50, and a connecting passage component 40.

Here, the configuration of the power generation engine 20 will be described. As shown in FIGS. 2 to 4, the power generation engine 20 includes a cylinder case 22 for accommodating a cylinder portion 21, a connecting pipe 28, a crankshaft 24, a crankcase 23 covering the crankshaft 24, and a first. It has a cooling fan 25.

The power generation engine 20 is arranged so that the crankshaft 24 extends in the vehicle width direction. The crankcase 23 surrounds the crankshaft 24 and extends in the vehicle width direction. As shown in FIG. 3, the first cooling fan 25 is attached to the left end of the crankshaft 24 in the vehicle width direction via a speed reducer or the like, and rotates with the rotation of the crankshaft 24. Further, the first intake port 27 provided in the first cooling fan 25 is arranged so as to face the left outer side in the vehicle width direction. In this example, the first intake port 27 is arranged on the left outer side in the vehicle width direction of the power generation unit 1.

The cylinder cases 22 are arranged side by side on the vehicle rear side of the crankcase 23 and extend in the vehicle width direction. As shown in FIGS. 5 and 6, an opening 22a for exhausting air in the cylinder case 22 is provided at the right end of the cylinder case 22 in the vehicle width direction. Further, a fan cover 26 covering the first cooling fan 25 is attached to the left side portion of the crankcase 23 and the cylinder case 22 in the vehicle width direction. The fan cover 26 extends in the front-rear direction of the vehicle and is connected to the left end portion of the cylinder case 22 in the vehicle width direction so as to communicate with fluid. The air taken in by the first cooling fan 25 passes through the inside of the fan cover 26 and flows into the inside of the cylinder case 22.

As shown in FIG. 4, a plurality of cooling fins 21a are provided on the outer surface of the cylinder portion 21 of the power generation engine 20. For example, as shown in FIG. 4, the plurality of cooling fins 21a provided on the upper surface of the cylinder portion 21 project upward from the upper surface of the cylinder portion 21 and are spaced apart from each other in the vehicle front-rear direction to the vehicle width direction (muffler). It extends along the longitudinal direction of 50).

As shown in FIGS. 2 and 3, the connecting pipe 28 is connected to the muffler main body 51, which will be described later, of the muffler 50. The exhaust gas generated when the power generation engine 20 is being driven circulates inside the connecting pipe 28, flows into the inside of the muffler main body 51, and is exhausted from the muffler main body 51 to the outside.

The muffler 50 has a muffler main body 51 and a cover member 53. The muffler main body 51 is a long member extending in the vehicle width direction and has a catalyst or the like inside. As shown in FIGS. 2 and 7, an upper surface 51a convex upward and a substantially flat lower surface 51c And a front wall surface 51b facing the front of the vehicle and a rear wall surface 51d facing the rear of the vehicle. The front wall surface 51b and the rear wall surface 51d extend substantially perpendicular to the lower surface 51c.

A connecting pipe 28 is connected to the left end portion of the muffler main body 51 in the vehicle width direction, and an outer exhaust pipe 52 for exhausting exhaust gas to the outside is provided at the right end portion in the vehicle width direction. As shown in FIG. 2, the outer exhaust pipe 52 extends from the right end of the muffler main body 51 to the right outside in the vehicle width direction and is curved downward on the vehicle. The outer exhaust pipe 52 is provided with an exhaust port (not shown) facing below the vehicle.

The cover member 53 has a hollow substantially rectangular parallelepiped shape, and as shown in FIG. 2, the muffler main body 51 is housed inside. The cover member 53 extends in the vehicle width direction along the longitudinal direction of the muffler main body 51, has openings at both ends in the vehicle width direction, and is formed of a heat shield plate (inner heat shield plate 53A, outer heat shield plate 53B). .. The left end portion of the cover member 53 in the vehicle width direction is arranged side by side in the vehicle width direction and faces the opening 22a of the cylinder case 22. In this example, the opening 22a of the cylinder case 22 is located above the opening at the left end of the cover member 53.

As shown in FIG. 2, the inner heat shield plate 53A has an upper surface portion 53a and a front surface portion 53b extending downward from the front end of the upper surface portion 53a. The upper surface portion 53a is arranged at an interval on the upper side of the vehicle with respect to the upper surface 51a of the muffler main body 51, and the front surface portion 53b is arranged at an interval on the front side of the vehicle with respect to the front wall surface 51b of the muffler main body 51. Has been done.

The outer heat shield plate 53B has a lower surface portion 53c and a rear surface portion 53d extending upward from the rear end of the lower surface portion 53c. The lower surface portion 53c is arranged with a space below the vehicle with respect to the lower surface 51c of the muffler main body 51, and the rear surface portion 53d is arranged with a space behind the vehicle with respect to the rear wall surface 51d of the muffler main body 51. Has been done. The muffler main body 51 is supported by a bracket or the like with respect to the lower surface portion 53c, the front surface portion 53b, the rear surface portion 53d, and the like of the cover member 53. As a result, the distance between the upper surface portion 53a, the front surface portion 53b, the lower surface portion 53c and the rear surface portion 53d of the cover member 53 and the upper surface 51a, the front wall surface 51b, the lower surface 51c and the rear wall surface 51d of the muffler main body 51 is maintained. There is.

Further, as shown in FIG. 2, a flange 53f projecting upward from the vehicle is provided at the rear portion of the upper surface portion 53a of the inner heat shield plate 53A, and the flange 53f is an upper portion of the rear surface portion 53d of the outer heat shield plate 53B. Is joined with bolts or the like. Although not shown, the lower portion of the front surface portion 53b of the inner heat shield plate 53A and the front portion of the lower surface portion 53c of the outer heat shield plate 53B are joined.

The connecting passage component 40 is an annular member provided between the cylinder case 22 and the cover member 53, connecting the left end portion of the cover member 53 in the vehicle width direction and the opening 22a of the cylinder case 22, and is a light metal. , A heat-resistant resin material, a heat shield plate similar to the cover member 53, or the like. The connecting passage component 40 extends in the vehicle width direction, closes the opening at the left end of the cover member 53, and closes the opening 22a of the cylinder case 22.

As shown in FIGS. 5 and 6, the upper portion of the connecting passage component 40 connects the left end of the upper surface portion 53a of the cover member 53 and the upper portion of the opening 22a, and the vehicle proceeds from the opening 22a toward the cover member 53. It is configured to be wider in the front-back direction.

Similarly, the front portion of the connecting passage component 40 connects the left end of the front surface portion 53b of the cover member 53 and the front side portion of the opening 22a. The front portion is inclined toward the front side of the vehicle from the opening 22a toward the cover member 53. Further, the lower portion of the connecting passage component 40 connects the left end of the lower surface portion 53c of the cover member 53 and the lower portion of the opening 22a, and is inclined downward from the opening 22a toward the cover member 53. ..

Further, the rear portion of the communication component 40 connects the left end of the rear surface portion 53d of the cover member 53 and the rear side portion of the opening 22a. In the present embodiment, the rear portion of the connecting passage component 40 is arranged so as to penetrate the connecting pipe 28 in a sealed state.

As shown in FIG. 7, the distance between the upper surface portion 53a, the front surface portion 53b, the lower surface portion 53c and the rear surface portion 53d of the cover member 53 and the upper surface 51a, the front wall surface 51b, the lower surface 51c and the rear wall surface 51d of the muffler main body 51 is , Consists of a first cooling passage 58 through which air flows. The air exhausted from the opening 22a of the cylinder case 22 flows into the first cooling passage 58 via the connecting passage component 40.

Here, the air flow of the first cooling system 11 will be described. The air taken in from the first intake port 27 by the first cooling fan 25 passes through the inside of the fan cover 26 and flows into the inside of the cylinder case 22. At this time, air is blown to the plurality of cooling fins 21a on the outer surface of the cylinder portion 21. The air blown onto the cooling fins 21a flows between the adjacent cooling fins 21a along the longitudinal direction (vehicle width direction) of the cooling fins 21a to cool the cooling fins 21a.

The air that has passed between the cooling fins 21a of the cylinder portion 21 is exhausted from the opening 22a of the cylinder case 22 and flows into the connecting passage component 40. The air flowing inside the connecting passage component 40 flows through the first cooling passage 58 formed between the cover member 53 and the muffler main body 51, cools the muffler main body 51, and is exhausted from the opening at the right end of the cover member 53. Then, for example, it is diffused and exhausted to the outside of the power generation unit 1.

Subsequently, the details of the second cooling system 12 will be described. The second cooling system 12 is configured so that cooling air flows toward the muffler 50 through the heat radiation fins 36 of the inverter 35. As shown in FIGS. 1 and 7, the second cooling system 12 has a first air guide duct 61 and a second air guide duct 64. The first air duct 61 is attached to the upper part of the fuel tank 30 in a state of covering a part of the upper wall surface 31 of the fuel tank 30 and the heat radiation fins 36 of the inverter 35. The second air guide duct 64 is connected to the first air guide duct 61 and is attached to the upper part of the fuel tank 30 in a state of covering a part of the upper wall surface 31 of the fuel tank 30.

The first air duct 61 extends in the front-rear direction of the vehicle, has a U-shaped cross section that opens downward in the vehicle, and covers the upper wall surface 31 of the fuel tank 30 from the upper side of the vehicle. The front portion of the first air guide duct 61 projects toward the front side of the vehicle from the front end of the fuel tank 30, and a second cooling fan 63 is provided in the front portion.

The front portion of the first air guide duct 61 projects toward the front side of the vehicle from the front end of the fuel tank 30, and a second cooling fan 63 is provided in the front portion. Further, a second intake port 62 into which outside air flows is provided at the front end of the first air guide duct 61 located on the vehicle front side of the second cooling fan 63. The second intake port 62 is arranged so as to face the front of the vehicle. In this example, the second intake port 62 is arranged at the front portion of the power generation unit 1. By rotating the second cooling fan 63, outside air is taken in from the second intake port 62.

An inverter 35 is attached to the upper surface portion 61a of the first air duct 61. For example, an opening is provided in the upper surface portion 61a, and the inverter 35 is attached to the opening. As shown in FIG. 7, the heat radiation fins 36 of the inverter 35 are arranged on the vehicle lower side of the upper surface portion 61a of the first air duct 61.

The second air guide duct 64 has a U-shaped cross section that opens downward to the vehicle, and is inclined downward from the rear end of the first air duct 61 toward the rear side of the vehicle. The rear portion of the second air duct 64 projects toward the rear side of the vehicle from the rear end of the fuel tank 30, and the radiator 39 is arranged at the rear portion. At the rear end of the second air duct 64, a second exhaust port 65 that opens so as to face the cover member 53 of the muffler 50 is provided.

The first air guide duct 61 and the second air guide duct 64 cover the recess 32 of the fuel tank 30 from the upper side of the vehicle, and a second cooling passage 68 is formed.

The air taken in from the second intake port 62 by the second cooling fan 63 flows into the second cooling passage 68. At this time, air is blown to the plurality of heat radiation fins 36 of the inverter 35. The air blown onto the heat radiating fins 36 passes between the adjacent heat radiating fins 36 and cools the heat radiating fins 36. The air that has passed between the heat radiating fins 36 is blown onto the outer surface of the radiator 39 to cool the radiator 39. The air blown to the radiator 39 is blown from the exhaust port onto the upper surface portion 53a of the cover member 53 of the muffler 50 to cool the muffler 50. The air blown onto the upper surface portion 53a of the cover member 53 is, for example, diffused to the outside of the power generation unit 1 and exhausted.

The first cooling system 11 makes it possible to cool a large amount of heat generated from the power generation engine 20 and the muffler 50 to such an extent that the endurance temperature of the machine such as the heat generation engine 20 is not exceeded. The air temperature of the air cooling the cooling fins 21a of the cylinder portion 21 of the power generation engine 20 becomes high, but the air flowing through the first cooling system 11 is a power generation unit other than the members constituting the first cooling system 11. It can be discharged to the outside of the power generation unit 1 in a state where the influence on the space in which the constituent members of 1 are arranged is suppressed.

The air exhausted from the opening 22a of the cylinder case 22 flows into the first cooling passage 58 via the connecting passage component 40. The flow path cross-sectional area of the first cooling passage 58 is smaller than the flow path cross-sectional area of the connecting passage component 40. Therefore, since air flows from the wide space into the narrow space, the flow velocity of the air in the first cooling passage 58 is larger than the flow velocity in the connecting passage component 40, so that the heat transfer coefficient is high and the muffler is sufficiently used. Can be cooled to.

Further, the air flowing through the first cooling system 11 is isolated from the space in the power generation unit 1 in which other devices are arranged by the cylinder case 22, the connecting passage component 40, and the cover member 53. Therefore, it is possible to suppress the diffusion of heat in the first cooling system 11 into the power generation unit 1, and the heat affects the electric equipment such as the inverter 35, the fuel tank 30, and the intake air to the power generation engine 20. Can be reduced.

Further, according to the present embodiment, the longitudinal direction of the cooling fins 21a of the cylinder portion 21 is arranged so as to be the vehicle width direction, and the flow direction from the cooling fins 21a to the opening 22a is set to the longitudinal direction of the muffler 50. Since the layout is adapted to the vehicle width direction), the air taken in from the first cooling fan 25 flows without stagnation, so that the flow loss can be reduced and the local temperature rise can be reduced. As a result, the cooling efficiency is increased in the entire first cooling system 11.

Further, the cover member 53 is formed along the longitudinal direction of the muffler main body 51. As a result, the first cooling passage 58 between the muffler main body 51 and the cover member 53 becomes a narrow passage that is substantially homogeneous in the vehicle width direction, so that cooling air having a high flow velocity flows, and the heat transfer coefficient can be kept high. Therefore, the muffler main body 51 can be sufficiently cooled.

Further, in the present embodiment, since the first cooling fan 25 is synchronized with the crankshaft 24, the air flow rate taken in by the first cooling fan 25 changes according to the operation (particularly the rotation speed) of the power generation engine 20. For example, the air volume is configured to increase as the rotation speed of the crankshaft 24 increases. That is, when the rotation speed of the crankshaft 24 increases and the calorific value increases, the air volume of the cooling air also increases accordingly, so that cooling can be performed efficiently.

Further, in the present embodiment, the crankcase 23 is provided with a fan cover 26 that covers the first cooling fan 25 to form a series of passages with the cylinder case 22, so that the air introduced by the first cooling fan 25 is introduced. It can be sprayed directly toward the cooling fin 22 of the cylinder portion 21 without being involved in the cooling of other devices. That is, since the air immediately after being introduced by the first cooling fan 25 can be uniquely used for cooling the power generation engine 20 having the largest calorific value, the power generation engine 20 can be efficiently cooled. Further, the air flow direction on the outer surface of the cylinder portion 21 is controlled so as to be orthogonal to the thin Linda axis, for example, and the cooling efficiency of the power generation engine 20 can be improved.

Further, as described above, by setting the longitudinal directions of the crankshaft 24 and the muffler 50 to be the same (vehicle width direction), the power generation engine 20, the muffler 50, and various pipes are arranged in a straight line. Since it can be arranged in, a compact layout is possible. Since the layout requires a certain length, in the present embodiment, the layout is arranged along the vehicle width direction.

Further, in the above configuration, the first intake port 27 faces the outside in the vehicle width direction. As a result, it is possible to suppress the direct reception of the steering wind when the vehicle is running, and to reduce the intrusion of muddy water, dust and the like. Therefore, the air flow path of the first cooling system 11 can be kept clean, and the decrease in cooling efficiency can be reduced.

The description of the present embodiment is an example for explaining the present invention, and does not limit the invention described in the claims. Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

For example, in the present embodiment, the power generation unit 1 is arranged in the inner region of the frame 2 assembled in a substantially rectangular parallelepiped shape, but the present invention is not limited to this. For example, the power generation unit 1 may be housed in the case. In this case, the exhaust port of the outer exhaust pipe 52 provided at the end of the muffler main body 51 may be arranged on the outside of the case, and the exhaust port of the first cooling system 11 may be arranged so as to face the outside of the case. .. Further, in this case, the second cooling system 12 may be provided with an exhaust port for exhausting the air that has cooled the cover member 53 of the muffler 50 to the outside of the case, for example, at the left end portion of the muffler 50.

Further, in the present embodiment, the cooling fins 21a provided on the upper surface of the cooling fins 21a of the cylinder portion 21 are extended along the vehicle width direction, but the present invention is not limited to this. For example, the cooling fins 21a may be inclined so as to connect between the first cooling fan 25 and the opening 22a.

1 Power generation unit 2 Frame 11 First cooling system 12 Second cooling system 20 Power generation engine 21 Cylinder part 21a Cooling fin 22 Cylinder case 22a Opening 23 Crankcase 24 Crankshaft 25 First cooling fan 26 Fan cover 27 First Intake port 28 Communication pipe 30 Fuel tank 31 Upper wall surface 32 Recession 32a Bottom surface 35 Inverter 36 Heat dissipation fin 38 Generator 39 Radiator 40 Communication passage parts 50 Muffler 51 Muffler body 51a Upper surface 51b Front wall surface 51c Lower surface 51d Rear wall surface 52 Member 53A Inner heat shield plate 53a Upper surface portion 53b Front portion 53B Outer heat shield plate 53c Lower surface portion 53d Rear surface portion 53f Flange 58 First cooling passage 61 First air guide duct 61a Upper surface portion 62 Second intake port 63 Second cooling fan 64 Second air duct 65 Second exhaust port 68 Second cooling passage

Claims (4)

In the cooling structure of a power generation unit for a range extender vehicle, which comprises a power generation engine that supplies electric power to the vehicle and a muffler through which exhaust gas emitted from the power generation engine flows.
The power generation engine has a cylinder case for accommodating a cylinder portion and a cooling fan for inflowing air into the cylinder case, and an opening for exhausting air in the cylinder case is provided in the wall portion of the cylinder case. There is a part,
The muffler has a muffler main body through which the exhaust gas flows, and a cover member that covers the muffler main body and is formed of a heat shield plate.
A connecting passage component is provided between the cover member and the cylinder case.
The range extender vehicle is configured such that the air taken in by the cooling fan flows inside the cover member through the cylinder case and the connecting passage component and is exhausted to the outside. Cooling structure of the power generation unit. Between the cylinder case and the cylinder portion, the air taken in by the cooling fan flows along the longitudinal direction of the muffler body,
A cooling fin extending along the longitudinal direction of the muffler is provided on the outer surface of the cylinder portion.
The cover member extends along the longitudinal direction of the muffler body and extends.
A cooling passage extending in the longitudinal direction of the muffler body is formed between the muffler body and the cover member.
The range extender according to claim 1, wherein the connecting passage component is connected to one of the cover members in the longitudinal direction, and an exhaust port is provided in the other end in the longitudinal direction. Cooling structure of vehicle power generation unit. The cooling fan is attached to the crankshaft of the power generation engine and rotates with the rotation of the crankshaft.
The power generation engine has a crankcase that covers the crankshaft, and the crankcase is provided with a fan cover that covers the cooling fan.
The cooling structure for a power generation unit for a range extender vehicle according to claim 1 or 2, wherein the fan cover communicates with the cylinder cover. The longitudinal direction of the crankshaft and the muffler body is arranged along the vehicle width direction.
The cooling structure for a power generation unit for a range extender vehicle according to claim 3, wherein the intake port provided in the cooling fan is arranged so as to face the outside in the vehicle width direction.

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