JPH0522637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motorcycle equipped with an air guide duct for cooling an intake system of an engine of the motorcycle.

[Prior Art] In a motorcycle in which an engine is fixed to a body frame and a fuel tank is provided above the engine, the engine's intake device such as a carburetor, intake conduit, air cleaner, etc. is connected to the fuel tank. It is often installed below and near the engine.

In this case, in order to prevent the engine from being exposed to high temperatures, a wind guide plate is opened in front of the engine and cooling air from the guide plate is guided to the engine cylinders (Japanese Patent Application Laid-open No. (See Publication No. 55-128615).

[Problems to be Solved by the Invention] In the conventional example described above, a decrease in power performance due to a temperature rise in the engine cylinder can be prevented, but the cooling air also cools the carburetor, which causes icing. There was a problem.

This invention has been made in view of the problems of the conventional technology, and provides an air guide duct that can improve intake efficiency and prevent icing of the carburetor by cooling the intake passage upstream of the carburetor. The aim is to provide a motorcycle equipped with

[Means for Solving the Problems] In order to achieve the above object, a motorcycle equipped with a wind guide duct according to the present invention has a carburetor disposed in the middle of an intake passage extending rearward from the rear side of the engine cylinder. In addition, in a motorcycle having an air guide path for introducing running wind to the rear side of the cylinder, the air guide path is connected to an inlet end facing forward at the front side of the cylinder and an intake passage behind the carburetor. The invention is characterized by comprising a wind guide duct having an outlet end that opens toward the wind direction.

[Function] When the motorcycle is running, fresh and cold air is very easily introduced into the air guide duct that opens in front of the engine, and this air is covered by the fuel tank and is difficult to be exposed to by the running wind due to the presence of the engine, etc. The air is discharged from the outlet end opening of the air guide duct towards the intake device which is exposed to high temperatures. At this time, since the outlet end opening of the air guiding duct is located on the upstream side of the carburetor, the cold running air does not hit the carburetor, but the air warmed by the cylinder hits the carburetor. Further, the air warmed by the carburetor and the cold running air from the air guide duct are mixed appropriately to cool the intake passage appropriately.

[Example] An example of the present invention will be described below with reference to the drawings.

In the figure, A is the body frame, a is the engine, b is the turbocharger, 1 is the fuel tank, and 2 is the seat.

The vehicle body frame A includes a down tube 3, a main valve 4, a tank rail 5, a seat biller tube 6 integrated with the tank rail 5, a seat rail 7, and a back stay 8 as its constituent members.

Engine a has a plurality of cylinders, for example four cylinders.
It is a cycle engine, and an exhaust pipe 9 is connected to each cylinder.

The exhaust pipes 9 are collected at a lower part of the engine a, and a turbocharger b is connected to the downstream side of the collection part 10.

The turbocharger b supercharges the intake air to the engine a, and is driven by exhaust energy from the collecting section 10.

11 is a tube member 12 attached to the turbocharger b.
The air cleaner 11 is connected to the turbocharger b through which air is introduced to the turbocharger b.

The air introduced into turbocharger b is sent under pressure to engine a, but between this turbocharger b and engine a, in detail, there is no air on the upstream side of the carburetor 13 connected to each cylinder of engine a. A surge tank 14 is provided.

The surge tank 14 is made of metal, such as aluminum casting, and has a relatively large capacity, and includes pipe members 15,
16 via turbocharger b and carburetor 1
3, the air pumped from turbocharger b is temporarily stored and rectified to prevent intake interference due to intake pulsation of engine a.

In such an air intake device, the air introduced into the turbocharger b is compressed and expands as the temperature rises, so a means for cooling the air is provided.

This cooling means includes cooling fins 17 provided on the outer peripheral surface of the surge tank 14.

The cooling fins 17 are integrally provided on substantially the entire outer periphery of the surge tank 14 and extend in the front-rear direction. Therefore, by providing the cooling fins 17 on the surge tank 14 having a large volume, that is, surface area, the heat dissipation effect is further promoted. Internal air is effectively cooled.

On the other hand, cooling fins 18 are provided on the outer periphery of the pipe member 15 that connects the turbocharger b to the surge tank 14 so that the air can be cooled even on the way from the turbocharger b to the surge tank 14.
is provided.

The air guide duct 19 according to the present invention has an inlet end 22 that opens toward the front in front of the cylinder of the engine a, and an outlet end 23 that opens toward the intake passage behind the carburetor 13. The air guide duct 19 allows the airflow to reach the air intake system, which is covered by the engine and tank rails 5 and is difficult to reach due to the presence of the engine, etc., and achieves a sufficient effect of cooling the air in the air intake system. The running wind does not hit the carburetor 13. Since the air around the carburetor 13 is sucked by the flow of the introduced running air, hot air is not trapped around the carburetor.

Note that the fresh and cold air discharged from the air guide duct 19 is introduced into the air intake device through the air cleaner 11, thereby further increasing the air intake efficiency.

[Effects of the Invention] In this invention, the air guide path is constituted by an air guide duct having an inlet end facing forward at the front side of the cylinder and an outlet end opening toward the intake passage behind the carburetor. Therefore, when the motorcycle is running, fresh, cold air is very easily introduced into the air guide duct that opens in front of the engine, and this air is covered by the fuel tank and is difficult to reach due to the presence of the engine, etc., and has a high temperature. The cold running air does not hit the carburetor, as it is discharged from the outlet end opening of the wind guide duct toward the intake device, which is exposed to
Since the air heated by the cylinder hits the carburetor, icing of the carburetor is prevented. In addition, the air warmed by the carburetor and the cold running air from the air guide duct are mixed appropriately and cool the intake passage appropriately, so the intake efficiency is improved without adversely affecting the atomization of gasoline due to excessive cooling. can be improved.

[Brief explanation of the drawing]

FIG. 1 shows a partially cutaway side view of an embodiment of the invention, and FIG. 2 shows a sectional view thereof. a...engine, 13...carburizer, 19...blow guide duct, 22...inlet end, 23...outlet end.

Claims (1)

[Claims] 1. In a motorcycle that has a carburetor disposed in the middle of an intake passage extending rearward from the rear side of a cylinder of the engine, and has an air guide passage that introduces running air to the rear side of the cylinder, the air guide passage is connected to the cylinder. A motorcycle equipped with an air guide duct, characterized in that the air guide duct is configured with an inlet end that faces forward and opens at the front side of the carburetor, and an outlet end that opens toward the intake passage on the rear side of the carburetor. .