JPH0717220B2 - Heat insulation structure of carburetor for scooter type motorcycles - Google Patents

Description

The present invention relates to a carburetor mounted on a scooter type motorcycle and a motorcycle, for preventing so-called percolation in which bubbles are generated due to temperature rise of fuel. Regarding the heat insulating structure.

[Conventional technology]

In a scooter-type motorcycle, it is general that a seat lower portion of a rear portion of a vehicle body is surrounded by a side cover, and an engine unit is vertically swingably disposed in the side cover. In such a vehicle, in order to improve the cooling efficiency of the engine, a forced air-cooled engine in which outside air is forcedly introduced around the engine by a cooling fan is often adopted. In such a forced air-cooled engine, the temperature of the cooling air rises while cooling each part of the engine and becomes hot air that is discharged toward the lower part of the vehicle body.

[Problems to be solved by the invention]

However, since the discharged cooling air has a high temperature, it is easily floated by its buoyancy. In particular, in a vehicle in which the engine surroundings are surrounded by side covers, there is no problem during traveling, but when stopped due to a signal or the like, hot air easily accumulates in the side covers. Therefore, in the motorcycles and motorcycles of this type, for example, the ambient temperature of the carburetor rises, the fuel temperature in the carburetor rises, and percolation easily occurs.

The present invention has been made to solve such a conventional problem, and prevents the ambient temperature around the carburetor from rising due to hot air after cooling the engine, and percolates the fuel in the carburetor. It is an object of the present invention to provide a heat insulating structure for a carburetor in a scooter type motorcycle or tricycle capable of preventing the heat generation.

[Means for solving problems]

The present invention relates to a scooter-type motorcycle including a forced air-cooled engine in a side cover so that the engine can swing freely,
A shield plate made of an elastic material is attached to the air shroud covering the engine above the cooling air discharge port and below the carburetor so that the shield plate shields the gap between the air shroud and the inner surface of the side cover. It is the heat insulating structure of the vaporizer characterized by the above.

Here, in the present invention, it is not always necessary to provide a gap between the outer end of the shield plate and the side cover, but rather the outer end of the shield plate may be brought into contact with the inner surface of the side cover.

[Action]

In the heat insulating structure of the carburetor according to the present invention, since the gap between the air shroud and the side cover is shielded by the shielding plate above the cooling air discharge port, hot air from the discharge port is prevented from rising due to buoyancy or the like. This can be prevented even when the vehicle is stopped due to a signal waiting, etc. Therefore, the ambient temperature around the vaporizer does not rise due to the hot air from the discharge port, and the occurrence of percolation can be prevented. In this case, since the shielding plate of the present invention is made of an elastic member such as rubber, even if the engine unit swings up and down even when the shielding plate and the side cover are in contact with each other, abnormal noise and vibration are generated. Almost never.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 are views for explaining a heat insulating structure of a carburetor in a scooter type motorcycle according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a scooter type motorcycle to which the structure of this embodiment is applied. A steering wheel cylinder 2a fixed to a front end portion of a body frame 2 of the motorcycle 1 has a front wheel 3 at its lower end. A front fork 4 which supports the steering handle 4a at its upper end is pivotally supported. A seat 5 is mounted above the rear portion 2b of the vehicle body frame 2, and a side cover 23 is arranged below the seat 5 so as to surround the lower portion. A swing type power unit 6 is arranged in the side cover 23 so as to be vertically swingable.
The power unit 6 is mainly a forced air-cooled four-cycle engine 10, a carburetor 24 connected to a cylinder head 10a of the engine 10 via an intake pipe 9, and an air cleaner 11 connected to the carburetor 24. It is composed of a transmission case 7 connected to a crankcase 10d of the engine 10. A rear wheel 8 is supported on a rear end portion of the transmission case 7, and the transmission case 7 and the rear portion of the vehicle body frame 2 are supported.
A cushion unit 25 is provided between the cushion unit 25 and 2b.

Further, the cylinder head 10a and the cylinder 10 of the engine 10 are
A steel plate air shroud 12 is disposed in the portion b to cover them. The air shroud 12 is a right shroud 1 that covers the right side surface, the upper side surface, and the left side surface of the engine 10, respectively.
3. It comprises an upper shroud 14 and a left shroud 15, which are fixed to the engine 10 by mounting bolts 16, respectively. An insertion port 15a for inserting the intake pipe 9 is formed on the upper surface of the left shroud 15, and an exhaust duct for discharging cooling air is provided in the left shroud 15.
18 connected. A fan case cover 17 that covers a cooling fan (not shown) is attached to the right side surface of the crankcase 10d, and an upper edge portion of the cover 17 is connected to a lower edge of the right shroud 13. As a result, the outside air is sucked into the fan case cover 17, and the air is blown along the surface of the engine 10.
A cooling passage is configured to discharge the air from.

The left shroud 15 and the upper shroud 14 are then
A shielding plate 19 is provided on the upper surface of the. The shielding plate 19 is formed by sticking an aluminum foil on the lower surface of a rubber substrate, and is composed of a left side portion 19a and a right side portion 19b. The right side
19b extends on the upper surface of the upper shroud 14 so as to cover the lower part of the carburetor 24, and shields radiant heat from the upper shroud 14. The left side portion 19a extends outward and rearward in the vehicle radial direction on the upper surface of the left side shroud 15 and has an outer end 19c.
Is opposed to the side cover 23 with a slight gap 23a, so that the left side portion 19a of the air shroud 1
The gap between 2 and the side cover 23 is almost completely shielded.
The left side portion 19a has an insertion opening 1 for the left shroud 15 described above.
An insertion opening 19d having the same shape as that of 5a is formed, and an assembling cutout 19e is formed from the insertion opening 19d to the outer end 19c.

Further, on the upper surface of the insertion port 19d of the left side portion 19a of the shielding plate 19,
A rubber seal plate 20 is arranged, and a pressing plate 21 arranged on the seal plate 20 is fixed to the left shroud 15 by a mounting bolt 22, whereby the seal plate 20 and the shield plate 19 are arranged on the air shroud 12. It is fixed together with. The peripheral edge of the seal port 20a formed in the seal plate 20 is in contact with the outer peripheral surface of the intake pipe 9 in a pressed state due to its elasticity, whereby the left shroud is
The gap between the insertion port 15a of 15 and the intake pipe 9 is completely closed. Note that 20b is a notch for assembly.

Next, the function and effect of this embodiment will be described.

First, the case where the shielding plate 19 of this embodiment is mounted on the air shroud 12 in a state where the carburetor 24 and the like are assembled will be described. The shielding plate 19 is fitted into the intake pipe 9 by opening the notch 19e. The left side portion 19a and the right side portion 19b are aligned with a predetermined position, the sealing plate 20 is fitted on the intake pipe 9 in the same manner as described above, and finally the pressing plate 21 is placed and fixed by the mounting bolt 22. To do.

Next, the flow of the cooling air in the apparatus of the present embodiment will be described. The cooling air A sucked by the cooling fan as the engine 10 rotates is the cylinder 10b of the engine 10, the cylinder head 10a, and the shrouds 13-15. While cooling each part of the engine 10 through the gaps, the hot air B is discharged from the exhaust duct 18 to the lower side of the engine.

In this case, in the conventional device, there is a problem that the hot air B rises through the space between the engine 10 and the side cover 23 due to its buoyancy and tends to collect around the carburetor 24, especially when the vehicle is stopped. . On the other hand, in this embodiment, since the gap between the engine 10 and the side cover 23 is almost completely shielded by the shield plate 19, it is possible to almost completely prevent the hot air B from rising from the gap and therefore the carburetor 24. The surrounding ambient temperature does not rise, and percolation of fuel in the carburetor can be prevented.

Here, since the shielding plate 19 of the present embodiment is made of a rubber plate and has elasticity, even if it interferes with the side cover 23, it is deformed according to this, and abnormal noise and vibration are hardly generated.

Further, the shielding plate 19 of the present embodiment is formed by sticking an aluminum foil on the lower surface and has a shape that covers the lower part of the carburetor 24, so that the radiant heat from the engine 10 can be shielded, and from this point as well, vaporization is performed. It has the effect of preventing the percolation of the container 24.

Furthermore, in the structure of the present embodiment, since the gap between the intake pipe 9 and the insertion port 15a of the air shroud 12 is closed by the seal plate 20, abnormal noise due to the interference between the air shroud 12 and the intake pipe 9,
Cooling air can be prevented from leaking out without generating vibration and cooling efficiency can be improved.

In the above embodiment, the shield plate 19 has a two-layer structure of a rubber plate and an aluminum foil and covers the lower part of the carburetor 24. However, in the present invention, the shield plate has such a structure. It is not necessary to use the above, but the point is that the plate made of an elastic member may be configured to shield the gap between the engine and the side cover.

Further, in the above-described embodiment, a slight gap 23a is provided between the shield plate 19 and the side cover 23, but the present invention does not necessarily need to provide the gap, and both may be brought into contact with each other. Even in this case, since the shielding plate is made of an elastic member, problems such as abnormal noise and vibration due to vertical swing of the engine unit hardly occur, and rising of hot air can be prevented more reliably, It is even more effective as a measure against percolation.

Further, although the scooter type motorcycle has been described in the above embodiment, the present invention is not limited to such a vehicle, and the front one wheel,
The present invention can be applied to any vehicle such as a scooter type automatic three-wheeled vehicle having two rear wheels, as long as the engine is swingably mounted in the side cover.

〔The invention's effect〕

As described above, according to the heat insulating structure for the carburetor in the scooter-type motorcycle according to the present invention, the gap between the air shroud of the engine and the side cover is provided above the cooling air discharge port and below the carburetor. Since it is shielded by the elastic member shielding plate, it is possible to prevent the occurrence of abnormal noise and vibration, and also to prevent the ambient temperature around the carburetor from rising and to prevent the occurrence of percolation.

[Brief description of drawings]

1 to 3 are views for explaining a heat insulating structure of a carburetor in a scooter type motorcycle according to an embodiment of the present invention, FIG. 1 is a front view thereof, and FIG. 2 is a plan view thereof. FIG. 3 is a side view of a scooter type motorcycle to which the example structure of the above embodiment is applied. In the figure, 1 is a scooter type motorcycle, 2 is a vehicle body frame, 10 is an engine, 12 is an air shroud, 18 is a cooling air exhaust duct, 19 is a shielding plate, 23 is a side cover, and 24 is a carburetor.

Claims (1)

[Claims] 1. A rear cover of a vehicle body is surrounded by a side cover, and a forced air-cooled engine is vertically swingably arranged in the side cover so that cooling air for cooling each part of the engine is discharged below the engine. In a scooter type motorcycle, a shield plate made of an elastic member is attached to an air shroud covering the engine above the cooling air discharge port and below the carburetor, and the air shroud and the side cover are attached by the shield plate. A heat shield structure for a carburetor in a scooter-type motorcycle, characterized by shielding the gap between the inner surface of the car and the car.