JPH046597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motorcycle equipped with a water-cooled engine, and particularly relates to a location where a radiator for engine cooling water is installed.

Generally, motorcycles equipped with water-cooled engines are
It is known that the radiator is installed in the down tube in front of the engine. However, when arranging a radiator between the front of the engine and the front wheels, it has been impossible to arrange a large radiator that can sufficiently cool the engine due to the installation space of the vehicle body and the aerodynamic resistance of the vehicle body.

This invention aims to eliminate such problems. The present invention will be explained below with reference to illustrated embodiments. In the figure, reference numeral 1 denotes a motorcycle for competition, in which a front fork 4 having a front wheel 3 is supported in front of a body frame 2 so as to be freely turnable, and a rear fork 6 having a rear wheel 5 at the rear can be freely swung up and down. Supported. A down tube 2a and a main pipe 2b constituting the vehicle body frame 2 are connected to each other below the engine to form a so-called cradle-type frame. 7 is a water-cooled two-stroke engine suspended in the center of the vehicle body frame 2; 8 is a drive chain wound between the engine 7 and the rear wheels 5; A fairing 10 having a windshield 9 is attached to the vehicle body frame 2, and a cooling air intake 10a is opened in the front of the fairing 10. A running air passage 11 is formed on the lower surface of the engine 7 by a fairing thereof, which communicates with the intake port 10a at the front. 12 is the running wind passage 11
A radiator is provided inside, 13 is a passenger seat, and 13a is a fuel tank.

Note that it is preferable that the area around the cooling air intake port 10a widens greatly in a wrapper shape to guide the running wind that has passed past the sides of the front wheels 3 into the running wind passage 11.

3 and 4 show the surroundings of the engine 7 in detail. The water-cooled engine 7 has a crankcase 7a and a cylinder 7b extending upward. 14 is an intake system such as a carburetor connected to the front surface of the cylinder 7b of the engine 7; 15 is an exhaust system in an exhaust pipe connected to the rear surface of the cylinder 7b of the engine 7;
It has b. This configuration in which the exhaust pipe 15 is connected to the rear surface of the cylinder 7b can leave a larger space on the lower surface of the engine 7 compared to the conventional arrangement in which the exhaust pipe 15 extends toward the rear of the vehicle body through the lower surface of the engine. 16 is a cooling water pump;
The discharge port is connected to the cylinder 7b via the water supply pipe 17a.
The inlet is connected to the water inlet of the water intake pipe 17.
The water suction pipe 17b is connected to the drain port of the cylinder 7b via the pipe 17b, and a radiator is interposed in the middle of the water suction pipe 17b. The radiator 12 consists of a heat radiation part 12a and two cooling water tanks 12b, 12b sandwiching the heat radiation part 12a, and is bolted to the vehicle body frame 2 by stays 18, 19 so that the lower part thereof projects forward. FIG. 5 shows a modification of the radiator 12, and the radiator 12 shown in FIG.
In contrast to the conventional radiator in which cooling water tanks 12b are provided at the upper and lower portions of the heat radiator 12a, the one shown in FIG. 5 has cooling water tanks 12b arranged on the right and left sides of the heat radiator 12a. , the vertical dimensions of the radiator 12 are reduced. The running air passage 11 provided on the lower surface of the engine 7 is covered by the lower wall 10c of the fairing 10 to prevent muddy water and dirt from the road surface thrown up by the front wheels 3 from splashing onto the radiator 12. . 10
d is a running air duct integrally molded with the fairing 10, which connects the radiator 12 from the intake port 10a.
It extends to the front of the.

In the embodiment device having the above configuration, when the vehicle starts running, the running wind that has passed through the sides of the front wheels 3 is guided to the front surface of the radiator 12 from the intake port 10a provided in the fairing 10, and the radiator 12
cools the engine cooling water inside it,
Thereafter, it extends from the open rear part of the fairing 10 to the rear of the vehicle body via both sides of the rear wheel 5. and,
The radiator 12 is attached to the lower part of the vehicle body frame 2 with the lower part protruding forward, and the lower part and both sides of the radiator are covered with the fairing 10, so the radiator can be installed in a place with little clearance on the lower surface of the crankcase. Because it is effectively contained and the traveling wind hits the inclined surface of the radiator,
It is possible to generate a downward partial pressure due to the traveling wind.

As described above, the present invention provides a motorcycle in which a water-cooled engine is mounted on a body frame, in which an intake system is connected to the front surface of the cylinder of the water-cooled engine that extends upward from the body frame, and an exhaust system is connected to the rear surface of the cylinder. The radiator is mounted on the lower part of the vehicle body frame with the lower part protruding forward, avoiding the front of the intake system, and the lower part and both sides of the radiator are covered with fairings, so that it is protected from the wind while driving. This allows the engine's intake system to be cooled, preventing the intake system from heating up and deteriorating intake efficiency, and since the cylinders are also cooled by the running wind, the cooling capacity of the radiator is reduced. There is no need to provide a large radiator, and the amount of protrusion on the left and right sides of the vehicle body is reduced, which not only reduces the aerodynamic resistance of the vehicle body to airflow, but also reduces the weight of the vehicle, making it easier to maneuver. In addition, since the radiator is installed at an angle at the bottom of the vehicle body frame, with the bottom part protruding forward, the radiator can be effectively placed in a place with little clearance on the underside of the crankcase, and the effective surface area is small considering its low installation height. In addition to providing a radiator with a large capacity, the bottom and both sides of the radiator are covered with fairings, and the wind from the vehicle hits the inclined surface of the radiator, creating a downward partial pressure due to the wind from the vehicle. This increases the ground contact pressure of the driving wheels and improves the drivability of the motorcycle.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a side view of a competition motorcycle, FIG. 2 is a front view,
Figure 3 is a cross-sectional side view of the main parts of the fairing.
FIG. 4 is a front view thereof. FIG. 5 is a front view corresponding to FIG. 4 showing another embodiment. 7... Engine, 10... Fairing, 11
...Traveling wind passage, 12...Radiator.

Claims (1)

[Claims] 1. In a motorcycle in which a water-cooled engine is mounted on a body frame, an intake system is connected to the front surface of the cylinder of the water-cooled engine that extends upward from the body frame, and an exhaust system is connected to the rear surface of the cylinder. 1. A water-cooled motorcycle engine, characterized in that a radiator is installed at the lower part of a body frame at an angle so that the lower part protrudes forward, and the lower part and both sides of the radiator are covered with fairings.