JP7375397B2 - Cooling structure of power generation unit for range extender vehicle - Google Patents

Description

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

BACKGROUND ART Vehicles that are equipped with a small generator are known as electric vehicles driven by electric motors. The small-sized generator has, for example, a power generation engine, and can generate power with the power generation engine and supply electric power to the electric vehicle. By supplying power to the electric motor of the electric vehicle by the small generator, for example, the cruising distance of the electric vehicle can be extended. As such a small-sized generator, for example, a device disclosed in Patent Document 1 is known.

The small generator generates electricity using a power generation engine, and includes an inverter and the like. Moreover, a small-sized generator requires a cooling structure for cooling a power generation engine, an electric device such as the inverter, and the like.

Japanese Patent Application Publication No. 2008-169114

A small-sized generator like the above example generates heat by operating the power generation engine, so it is necessary to reduce the size and dissipate heat efficiently. For example, a power generation engine generates a large amount of heat compared to other devices that make up a small generator. Furthermore, the muffler into which exhaust gas from the power generation engine flows also has a higher temperature 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 caused to flow through the cooling passage in an attempt to lower the ambient temperature. As a result, a large amount of air flows into the space around devices that do not require high cooling performance (devices that generate a low amount of heat), or into the space around devices that require high cooling performance (devices that generate a large amount of heat). On the other hand, there is a possibility that the amount of air flowing will decrease. Therefore, in the structure as in the above example, there is room for improvement in cooling a device that generates a large amount of heat, such as an engine for power generation.

The present invention has been made to solve the above problems, and its purpose is to efficiently cool a power generation unit that generates power using a power generation engine, and in particular, to efficiently cool a power generation engine, etc. An object of the present invention is to provide a cooling structure for a power generation unit for a range extender vehicle.

A cooling structure for a power generation unit for a range extender vehicle according to the present invention to achieve the above object includes 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. We are prepared. In the cooling structure of the power generation unit for a range extender vehicle, the power generation engine has a cylinder case that accommodates a cylinder portion, and a cooling fan that flows air into the cylinder case, and a wall portion of the cylinder case has a cooling fan that flows air into the cylinder case. is provided with an opening for exhausting the air in the cylinder case, and the muffler includes a muffler main body formed in a long length through which the exhaust gas flows, and a muffler main body that covers the muffler main body and that covers the muffler main body. a cover member extending along the longitudinal direction and formed of a heat shield plate, the cylinder case and the muffler being arranged side by side along the longitudinal direction of the muffler body, and the cover member and the cylinder case, a communication passage part is provided along the longitudinal direction of the muffler body so as to connect the opening of the cylinder case and the cover member, and the passage part is taken in by the cooling fan. The air flowing into the cylinder case flows into the cover member along the longitudinal direction of the muffler body via the cylinder case and the communication passage component. , is configured to be exhausted to the outside, and the cross-sectional area of the flow path inside the cover member is set to be smaller than the cross-sectional area of the flow path of the communication passage component .

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

1 is a plan view showing an embodiment of a cooling structure for a power generation unit for a range extender vehicle according to the present invention. FIG. 2 is a schematic perspective view showing members constituting the first cooling system in FIG. 1. FIG. FIG. 2 is a side view of the power generation unit of FIG. 1 viewed from the left side in the vehicle width direction. FIG. 3 is a perspective view showing a state in which the cylinder case and the like of FIG. 2 are removed. FIG. 3 is a top view of the communication passage component and its surroundings in FIG. 2; FIG. 6 is a rear view of the connecting passage components and the like shown in FIG. 5 as viewed from the rear side of the vehicle. A cross-sectional view taken along the line AA in FIG. 1, showing the first cooling passage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cooling structure for a power generation unit for a range extender vehicle according to the present invention will be described below with reference to the drawings (FIGS. 1 to 7).

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

As shown in FIG. 1, the cooling structure of the power generation unit 1 for a range extender vehicle according to 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 explained. The power generation unit 1 of this embodiment includes a power generation engine 20, a fuel tank 30, a muffler 50, an inverter 35, and a generator 38 (power generation section). Further, the power generation unit 1 is arranged within an area 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 generates power when the power generation engine 20 is driven. 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 disposed on the right side of the power generation engine 20 in the vehicle width direction, as shown in FIG. A cap 30a is attached to the upper wall surface 31 of the fuel tank 30 to close an opening (not shown) for replenishing fuel.

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

As shown in FIGS. 1 and 7, the inverter 35 is a substantially rectangular parallelepiped device that is fixed to the upper part of the fuel tank 30 and extends in the longitudinal direction of the vehicle, and is electrically connected to the generator 38. A plurality of heat radiation fins 36 are provided at the bottom of the inverter 35. Each of the heat radiation fins 36 protrudes downward from the lower part of the inverter 35 and extends in the longitudinal direction of the vehicle, and the plurality of heat radiation fins 36 are spaced apart from each other in the vehicle width direction.

First, details of the first cooling system 11 will be explained. The first cooling system 11 is configured so that cooling air flows from the power generation engine 20 toward the muffler 50, as shown in FIG. The first cooling system 11 includes a power generation engine 20, a muffler 50, and a communication passage component 40.

Here, the configuration of the power generation engine 20 will be explained. As shown in FIGS. 2 to 4, the power generation engine 20 includes a cylinder case 22 that accommodates a cylinder portion 21, a communication pipe 28, a crankshaft 24, a crankcase 23 that covers the crankshaft 24, and a first It has a cooling fan 25.

The power generation engine 20 is arranged such 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 reduction gear or the like, and rotates as the crankshaft 24 rotates. 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 of the power generation unit 1 in the vehicle width direction.

The cylinder case 22 is arranged in line with the crankcase 23 on the rear side of the vehicle, and extends in the vehicle width direction. As shown in FIGS. 5 and 6, an opening 22a for exhausting air within 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 that covers the first cooling fan 25 is attached to the left side of the crank case 23 and the cylinder case 22 in the vehicle width direction. The fan cover 26 extends in the longitudinal direction of the vehicle and is connected to the left end of the cylinder case 22 in the vehicle width direction so as to communicate fluidly therewith. 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 protrude upward from the upper surface of the cylinder portion 21 and are spaced apart from each other in the longitudinal direction of the vehicle. 50 longitudinal direction).

The communication pipe 28 is connected to a muffler main body 51 of the muffler 50, which will be described later, as shown in FIGS. 2 and 3. Exhaust gas generated when the power generation engine 20 is driven flows through the communication pipe 28, flows into the muffler body 51, and is exhausted from the muffler body 51 to the outside.

The muffler 50 includes 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 etc. inside, and as shown in FIGS. 2 and 7, has an upper surface 51a that is convex above the vehicle and a substantially flat lower surface 51c. , 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 perpendicularly to the lower surface 51c.

A communication pipe 28 is connected to the left end of the muffler body 51 in the vehicle width direction, and an outer exhaust pipe 52 through which exhaust gas is exhausted to the outside is provided at the right end 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 outer side in the vehicle width direction, and is curved toward the lower side of the vehicle. The outer exhaust pipe 52 is provided with an exhaust port (not shown) that faces downward from 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 body 51, is open at both ends in the vehicle width direction, and is formed of heat shield plates (inner heat shield plate 53A, outer heat shield plate 53B). . The left end of the cover member 53 in the vehicle width direction is arranged in line with and faces the opening 22a of the cylinder case 22 in the vehicle width direction. In this example, the opening 22a of the cylinder case 22 is located at the upper part of 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 vehicle from the front end of the upper surface portion 53a. The upper surface portion 53a is arranged at a distance above the vehicle from the upper surface 51a of the muffler main body 51, and the front surface portion 53b is arranged at a distance from the front wall surface 51b of the muffler main body 51 toward the front side of the vehicle. 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 spaced from the lower surface 51c of the muffler main body 51 toward the lower side of the vehicle, and the rear surface portion 53d is spaced from the rear wall surface 51d of the muffler main body 51 toward the rear of the vehicle. has been done. The muffler main body 51 is supported on the lower surface portion 53c, front surface portion 53b, rear surface portion 53d, etc. of the cover member 53 via a bracket or the like. As a result, the distance between the upper surface 53a, front surface 53b, lower surface 53c, and rear surface 53d of the cover member 53 and the upper surface 51a, front wall surface 51b, lower surface 51c, and rear wall surface 51d of the muffler main body 51 is maintained. There is.

Further, as shown in FIG. 2, a flange 53f that protrudes upward from the vehicle is provided at the rear part of the upper surface part 53a of the inner heat shield plate 53A, and the flange 53f is attached to the upper part of the rear surface part 53d of the outer heat shield plate 53B. It is connected to the base with bolts, etc. Although not shown, the lower part of the front surface part 53b of the inner heat shield plate 53A and the front part of the lower face part 53c of the outer heat shield plate 53B are joined.

The communication passage component 40 is an annular member that is provided between the cylinder case 22 and the cover member 53, connects the left end of the cover member 53 in the vehicle width direction and the opening 22a of the cylinder case 22, and is made of light metal. , a heat-resistant resin material, a heat shield plate similar to the cover member 53, or the like. The communication 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 part of the communication passage component 40 connects the left end of the upper surface part 53a of the cover member 53 and the upper part of the opening 22a, and as it goes from the opening 22a toward the cover member 53, It is configured to be wider in the front and back direction.

Similarly, the front part of the communicating passage component 40 connects the left end of the front part 53b of the cover member 53 and the front side part of the opening 22a. The front portion is inclined toward the front of the vehicle as it goes from the opening 22a toward the cover member 53. Further, the lower part of the communication passage component 40 connects the left end of the lower surface part 53c of the cover member 53 and the lower part of the opening 22a, and is inclined toward the lower side of the vehicle as it goes from the opening 22a to 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 this embodiment, the communication pipe 28 is disposed through the rear part of the communication passage component 40 in a sealed state.

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

Here, the flow of air in the first cooling system 11 will be explained. 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 onto 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 adjacent cooling fins 21a along the longitudinal direction (vehicle width direction) of the cooling fins 21a, thereby cooling the cooling fins 21a.

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

Next, details of the second cooling system 12 will be explained. The second cooling system 12 is configured so that cooling air flows toward the muffler 50 through the radiation fins 36 of the inverter 35 . The second cooling system 12 includes a first air guide duct 61 and a second air guide duct 64, as shown in FIGS. 1 and 7. The first air guide duct 61 is attached to the upper part of the fuel tank 30 so as to cover a part of the upper wall surface 31 of the fuel tank 30 and the 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 so as to cover a part of the upper wall surface 31 of the fuel tank 30.

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

A front portion of the first air guide duct 61 projects further toward the front of the vehicle than the front end of the fuel tank 30, and a second cooling fan 63 is provided at the front portion. Further, a second air intake port 62 through 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 of the power generation unit 1. As the second cooling fan 63 rotates, outside air is taken in from the second intake port 62.

The inverter 35 is attached to the upper surface portion 61a of the first air guide 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 lower side of the vehicle on the upper surface portion 61a of the first air guide duct 61. As shown in FIG.

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

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

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 onto the plurality of radiation fins 36 of the inverter 35. The air blown onto the radiation fins 36 passes between adjacent radiation fins 36 and cools the radiation fins 36. The air that has passed between the radiation fins 36 is blown onto the outer surface of the radiator 39 to cool the radiator 39. The air blown onto the radiator 39 is blown from the exhaust port onto the upper surface portion 53a of the cover member 53 of the muffler 50, thereby cooling the muffler 50. The air blown onto the upper surface portion 53a of the cover member 53 is, for example, diffused and exhausted to the outside of the power generation unit 1.

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 an extent that does not exceed the endurance temperature of the machine such as the heat generation engine 20. Although the air temperature of the air that has cooled the cooling fins 21a of the cylinder section 21 of the power generation engine 20 becomes high, the air that has passed through the first cooling system 11 does not pass through the power generation unit other than the members constituting the first cooling system 11. It is possible to discharge the power to the outside of the power generation unit 1 while suppressing the influence on the space in which the components of the power generation unit 1 are arranged.

Air exhausted from the opening 22a of the cylinder case 22 flows into the first cooling passage 58 via the communication passage component 40. The cross-sectional area of the first cooling passage 58 is smaller than the cross-sectional area of the communication 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 higher than the flow velocity in the communication passage component 40, so that the heat transfer coefficient is high and the muffler is sufficiently can be cooled to

Furthermore, the air flowing through the first cooling system 11 is isolated from a space in the power generation unit 1 in which other devices are arranged by the cylinder case 22, the communication passage component 40, and the cover member 53. Therefore, it is possible to suppress the heat in the first cooling system 11 from diffusing into the power generation unit 1, and the heat affects electrical equipment such as the inverter 35, the fuel tank 30, and the intake air to the power generation engine 20. It is possible to reduce the amount of

Further, according to the present embodiment, the longitudinal direction of the cooling fins 21a of the cylinder part 21 is arranged to be in the vehicle width direction, and the flow direction from the cooling fins 21a to the opening 22a is set in the longitudinal direction of the muffler 50 ( Since the layout is made according to the width direction of the vehicle, the air taken in from the first cooling fan 25 flows without stagnation, thereby reducing flow loss and local temperature rise. As a result, the cooling efficiency of the entire first cooling system 11 increases.

Further, a 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, allowing cooling air with a high flow velocity to flow, thereby maintaining a high heat transfer coefficient. Therefore, the muffler main body 51 can be sufficiently cooled.

Furthermore, in this embodiment, since the first cooling fan 25 is synchronized with the crankshaft 24, the amount of air taken in by the first cooling fan 25 changes depending on the operation (particularly the rotation speed) of the power generation engine 20. For example, the air volume is configured to increase as the rotational speed of the crankshaft 24 increases. That is, as the number of rotations of the crankshaft 24 increases and the amount of heat generated increases, the amount of cooling air also increases accordingly, allowing efficient cooling.

Furthermore, in this embodiment, the crankcase 23 is provided with a fan cover 26 that covers the first cooling fan 25 and forms a series of passages with the cylinder case 22, so that the air introduced by the first cooling fan 25 can be It is possible to directly spray the cooling fins 22 of the cylinder portion 21 without involving the cooling of other devices. That is, the air immediately after being introduced by the first cooling fan 25 can be used primarily for cooling the power generation engine 20, which generates the largest amount of heat, so the power generation engine 20 can be efficiently cooled. Furthermore, the direction of air flow on the outer surface of the cylinder portion 21 is controlled, for example, so as to be perpendicular to the cylinder axis, thereby making it possible to improve the cooling efficiency of the power generation engine 20.

In addition, as described above, by making the longitudinal direction of the crankshaft 24 and the muffler 50 the same (vehicle width direction), the power generation engine 20, the muffler 50, and the routing (arrangement) of various pipes can be arranged in a straight line. This allows for a compact layout. Since this layout requires a certain length, in this embodiment, the layout is arranged along the vehicle width direction.

Further, in the above configuration, the first intake port 27 faces outward in the vehicle width direction. This prevents direct exposure to steering wind when the vehicle is running, and reduces the intrusion of muddy water, dust, etc. Therefore, the air flow path of the first cooling system 11 can be kept clean, and a decrease in cooling efficiency can be reduced.

The description of this 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 of the claims.

For example, in the present embodiment, the power generation unit 1 is arranged in the inner region of the frame 2 assembled into a substantially rectangular parallelepiped shape, but the invention is not limited thereto. For example, the power generation unit 1 may be housed in a case. In this case, the exhaust port of the outer exhaust pipe 52 provided at the end of the muffler 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 example, at the left end of the muffler 50, for exhausting the air that has cooled the cover member 53 of the muffler 50 to the outside of the case.

Further, in the present embodiment, the cooling fins 21a of the cylinder portion 21, particularly the cooling fins 21a provided on the upper surface, extend along the vehicle width direction, but the invention is not limited thereto. For example, the cooling fins 21a may be inclined so as to connect the first cooling fan 25 to 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 fins 22 Cylinder case 22a Opening 23 Crank case 24 Crank shaft 25 First cooling fan 26 Fan cover 27 First Intake port 28 Connection pipe 30 Fuel tank 31 Top wall surface 32 Recess 32a Bottom surface 35 Inverter 36 Radiation fins 38 Generator 39 Radiator 40 Communication passage parts 50 Muffler 51 Muffler body 51a Top surface 51b Front wall surface 51c Bottom surface 51d Rear wall surface 52 Outside exhaust pipe 53 Cover Member 53A Inner heat shield plate 53a Top part 53b Front part 53B Outer heat shield 53c Lower part 53d Rear part 53f Flange 58 First cooling passage 61 First air guide duct 61a Top part 62 Second intake port 63 Second cooling fan 64 Second air guide duct 65 Second exhaust port 68 Second cooling passage

Claims (4)

In a cooling structure for a power generation unit for a range extender vehicle, the cooling structure includes 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 includes a cylinder case that accommodates a cylinder portion, and a cooling fan that allows air to flow into the cylinder case, and an opening that exhausts air in the cylinder case in a wall of the cylinder case. A department has been set up,
The muffler includes a long muffler body through which the exhaust gas flows, and a cover member that covers the muffler body, extends along the longitudinal direction of the muffler body, and is formed of a heat shield plate. have,
The cylinder case and the muffler are arranged side by side along the longitudinal direction of the muffler main body,
A communication passage component is provided between the cover member and the cylinder case so as to connect the opening of the cylinder case and the cover member along the longitudinal direction of the muffler body,
The air taken in by the cooling fan flows into the cylinder case, and the air that flows into the cylinder case flows through the cylinder case and the communication passage component along the longitudinal direction of the muffler body. configured to flow into the interior of the cover member and be exhausted to the outside ;
A cooling structure for a power generation unit for a range extender vehicle, wherein a cross-sectional area of a flow path inside the cover member is set to be smaller than a cross-sectional area of a flow path inside the communication passage component. Between the cylinder case and the cylinder part, air taken in by the cooling fan flows along the longitudinal direction of the muffler body,
Cooling fins extending along the longitudinal direction of the muffler are provided on the outer surface of the cylinder part ,
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 one longitudinal end of the cover member is connected to the communication passage component, and the other longitudinal end is provided with an exhaust port. Cooling structure for vehicle power generation units. The cooling fan is attached to the crankshaft of the power generation engine and rotates with 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 case . The longitudinal direction of the crankshaft and the muffler body are arranged along the vehicle width direction,
4. 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 to face outward in the vehicle width direction.