JP2646485B2 - Carburetor cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a carburetor cooling device for preventing heat damage from an engine.

(Conventional technology) A carburetor connected to an engine intake port is generally close to the engine, and is susceptible to heat damage such as percolation due to conduction or radiant heat from the engine. In order to prevent this, there is a method that intercepts conduction heat by interposing an insulator in a connection passage with the engine and intercepts radiant heat by interposing a shield plate. In addition, the layout is designed to facilitate the heat radiation by making it easy to touch the outside air and running wind.

However, a top field intake system is adopted in which the intake passage is linearly introduced substantially parallel to the cylinder axis.
In the cycle engine, it is difficult to take the above measures, and there is a disadvantage that the influence of heat damage is increased.

That is, the intake passage opens on the upper surface of the head cover, the carburetor is mounted on the upper surface of the head cover, and the air cleaner case is connected to the upper end of the carburetor, so that the carburetor is hidden in a narrow space vertically sandwiched between the head cover and the air cleaner case, It is difficult to touch the outside air efficiently, and it becomes a form that hot air can easily gather. If the air cleaner case is placed on the top of the head cover to house the carburetor and the air is sucked directly from the internal atmosphere, the air sucked into the case will come into contact with the carburetor, but it will be damaged by heat compared to the conventional type. It's still easy.

(Problems to be Solved by the Invention) As described above, the automatic carburetor with the carburetor mounted on the upper surface of the head cover and the air cleaner case connected above it.
There is a problem that a carburetor is susceptible to heat damage from an engine in an engine such as a wheeled vehicle, and the present invention provides a carburetor cooling device that prevents heat damage by promoting heat radiation of a carburetor unit. The purpose is to:

[Configuration of the invention]

(Means for Solving the Problems) With the above object, in the carburetor cooling device of the present invention, an automatic carburetor having an carburetor mounted on an upper surface of an engine head cover and an air cleaner case connected above the carburetor is mounted.
In an engine such as a wheeled vehicle, an independent carburetor chamber is formed which is surrounded by upper and lower wall surfaces including a head cover upper surface and an air cleaner case bottom surface and a peripheral wall surface extending from the head cover or the air cleaner case. The carburetor chamber is housed, and only the inlet is opened on the bottom surface of the air cleaner case, and the carburetor chamber has a wind guide port on the front wall and an exhaust port on the rear wall to allow the traveling wind to pass through the room.

(Operation) With the configuration described above, the traveling wind passes through the carburetor chamber as the vehicle travels, contacts the carburetor, and cools it. Since the carburetor chamber is formed as an independent chamber, even in a state in which a plurality of carburetors are in a forest, outside air enters into the inner central portion and widely touches the carburetor to enhance the cooling effect.

Thus, the carburetor is always cooled, thereby preventing heat damage from heat conduction and radiant heat from the engine side. Therefore, the conventionally used insulator and shield plate can be omitted.

Further, since the carburetor chamber forms one heat insulating layer, the air in the air cleaner case is indirectly cooled without being heated by the heat of the engine, so that it has an advantageous effect on the density of the intake air, that is, on the output.

(Embodiment) A description will be given below with reference to the drawings showing an embodiment of the present invention.

In FIG. 4, the motorcycle has an engine unit 1 arranged at the center of the vehicle body, which forms the core of the frame, and front and rear wheels 2 and rear wheels 3 arranged front and rear.

A front end of a swing arm 4 that supports the rear wheel 3 is pivotally supported by a rear edge of the engine unit 1, and a rear cushion unit 5 that is also mounted on the rear edge of the engine unit 1.
Is suspended by the shock absorber. A seat rail 7 on which the seat 6 is placed and a seat pillar 8 supporting the seat rail 7 are attached to the rear upper edge of the engine unit 1. Reference numeral 9 denotes a fuel tank disposed in front of the seat 6.

Next, a front fork 10 for buffering and suspending the front wheel 2 is supported via a steering head 12 via a steering head 12 at a box type connected to the upper front of the engine unit and at the front of a frame 11. 13 is its front cushion unit, 14
Indicates a handle.

As shown in FIGS. 1, 2 and 3, the frame 11 is a box type having openings 15 and 16 on the upper surface and the lower surface. Fixed. Mounting legs 18 on both sides of the lower surface
Is extended.

In addition, an inner flange 19 protrudes from a middle portion of the inner wall of the frame 11, and a partition plate 20 is stretched. Frame below inner flange 19
11 The front wall has an air vent 21 and the rear wall has an air vent 22.

The engine unit 1 has an engine portion extending forward and upward, and is provided with a rib 22 surrounding an upper surface peripheral portion of a head cover 1b attached to the cylinder head 1a. As shown in FIG. 4, an intake passage 24 that opens into the combustion chamber 23 of the cylinder head 1a extends directly upward along the axis of the cylinder 25, penetrates the head cover 1b, and opens on the upper surface thereof. Then, the carburetors 26 connected to the intake passage 24 are arranged on the upper surface of the head cover 1b.

The box-shaped frame 11 is connected to the engine unit 1 by fastening the attachment legs 18 to both side surfaces of the cylinder head 1a with fastening bolts 27. At this time, the opening
The 16 inner flanges 28 and the ribs 22 are joined via a sealing material 29, the opening 16 is closed by the head cover 1b,
An independent carburetor chamber 30 is formed between the carburetor 26 and the carburetor 26. Then, the inlet of the carburetor 26 penetrates through the partition plate 20 and opens into the frame 11 via the air funnel 31.

An air cleaner element 32 is put on the opening 15 on the upper surface of the frame 11, and a cap 33 is put on it. An inlet 34 opens in the cap 33. The fuel tank 9
Is continuously connected to the rear of the cap 33.

Thus, the inside of the frame 11 is formed as an air cleaner case together with the cap 33. The air sucked from the inlet 34 is purified through the air cleaner element 32, enters the frame 11, and opens inside the air funnel 31.
From the carburetor 26.

On the other hand, a traveling wind that is introduced from the wind guide port 21 and passes through the exhaust port 22 due to the traveling of the vehicle passes through the carburetor chamber 30 in the lower portion of the frame 11. This traveling wind widely contacts the outer surface of the carburetor 26 and cools the carburetor 26. Although the carburetor 26 is in a state where it is likely to receive heat from the engine, the cooling effect effectively prevents heat damage such as percolation.

Further, since the air in the frame 11 cut off in the carburetor chamber 30 is not heated by the heat of the engine, the temperature of the air taken into the carburetor 26 is stable, and the setting of the carburetor is easy, and at the same time, There is a positive effect on output characteristics due to air density.

In the figure, reference numeral 35 denotes a conduit connected to the exhaust port 22, and when its tip is opened to a portion having a negative pressure effect, an increase in air flow can be expected. In some cases, a fan can be used together.

〔The invention's effect〕

As described above, the carburetor cooling device according to the present invention includes:
The carburetor mounted on the top surface of the head cover was housed in a separate carburetor chamber formed between the top surface of the head cover and the bottom surface of the air cleaner case, and only the inlet was opened in the air cleaner case to allow the traveling wind to pass through the carburetor room. This has the effect of promoting the cooling of the carburetor due to the heat radiation, thereby protecting the engine from heat damage and improving the engine output performance.

[Brief description of the drawings]

FIG. 1 is a side view of an essential part of an engine showing a carburetor cooling device according to an embodiment of the present invention, FIG. FIG. 4 is a side view of the motorcycle equipped with the engine shown in FIG. 1, and FIG.
FIG. 3 is a vertical sectional side view showing a cylinder head portion of the engine shown in FIG. 1 ... Engine unit, 1a ... Cylinder head, 1b ...
… Head cover, 21 …… Ventilation port, 22 …… Exhaust port, 26 ……
Carburetor, 30 ... Carburetor room.

Claims (1)

(57) [Claims] In an engine such as a motorcycle having a carburetor mounted on an upper surface of an engine head cover and an air cleaner case connected above the upper and lower wall surfaces comprising an upper surface of the head cover and a lower surface of the air cleaner case, and extending from the head cover or the air cleaner case. An independent carburetor chamber surrounded by the provided peripheral wall is formed, the carburetor body is accommodated in the carburetor chamber, only the inlet is opened at the bottom of the air cleaner case, and a wind guide port is provided on the front wall of the carburetor chamber. A carburetor cooling device characterized in that an exhaust port is provided on a rear wall so that traveling wind passes through a room.