JPS6245113B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiator for a motorcycle equipped with a water-cooled engine.

Motorcycles generally use air-cooled engine cooling, but when equipped with a multi-cylinder, large-displacement engine, water-cooled engine cooling is used to evenly cool each part of the engine.

In a motorcycle equipped with such a water-cooled engine, a water jacket is provided around the outer periphery of the engine, and a radiator is provided in front of the engine. Cooling water heated by the engine is sent to a radiator by a water pump and cooled. It then goes back to the water jacket to cool the engine.

Such radiators are conventionally mounted in the upper part of a downtube extending downwardly from the steering head between the engine and the front wheels. This is because the radiator can be arranged efficiently and the contact area with the radiator's airflow can be increased. However, if the radiator is installed in the above position, the left and right ends of the radiator protrude significantly due to the cooling capacity and shape of the radiator, as well as the installation space, which may increase the aerodynamic resistance of the vehicle body to airflow. The dot was hot.

SUMMARY OF THE INVENTION An object of the present invention is to provide a radiator that can solve the above problems and reduce the aerodynamic resistance of a vehicle body to airflow.

The radiator according to the present invention is divided into an upper part and a lower part with the engine intake system in between, and is fixed to a down tube of a vehicle body frame, and the lower part is configured to protrude downward from the lowest end of the down tube. There is.

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a schematic side view of a motorcycle having a radiator according to the present invention, and FIG. 2 is a front view of the radiator portion taken in the direction of arrow Z in FIG. In Figures 1 and 2, 1 is a steering head pipe, 2 is a front fork, and the steering head pipe 1 has two upper tubes 3 and two down tubes 4 symmetrically.
are respectively attached, and the tubes 3 and 4 are connected at the lower portions of the left and right sides to form a single unit, forming a triangular space inside when viewed from the side. A water-cooled engine 8 having three cylinders 5, 6, and 7 is provided in this space together with a crankcase 9.
0 to 13 are fixed to the upper and down tubes 3 and 4. In addition, each cylinder 5,
6 and 7 are provided with carburetors 14, 15, and 16, each having an intake hole in the traveling direction, and exhaust pipes 17 and 18 (one not shown) extending long to the rear end of the vehicle body. A stay 20 is provided on the front wheel 19 side of the down tube 4 above the intake holes of the carburetors 14 and 15.
A radiator 22 is fixed by 21.
Further, a radiator 25 is fixed to the front wheel 19 side of the down tube 4 below the intake hole of the carburetor 16 by stays 23 and 24 so as to protrude downward from the lowest end of the down tube 4. The shape of the radiator 22 when viewed from the front wheel 19 is a square, and the shape of the radiator 25 is so-called an inverted trapezoid, with the width of the lower end gradually becoming narrower than that of the upper end. Note that the radiators 22 and 25 are provided with a water intake pipe and a water discharge pipe (not shown) so that cooling water circulates to a water jacket (not shown) provided in the engine 8.

In this configuration, the radiator 22 is provided at the same position as the conventional one, but as shown in FIG. 3, the width of the radiator 22 is smaller than that of the conventional one (broken line a). For this reason, since the capacity of the radiator 22 is reduced accordingly, an inverted trapezoidal radiator 25 is provided below the down tube 4, avoiding the carburetors 14, 15, 16, etc. that require air flow. Therefore, the total capacity of the radiators remains the same as before, and the individual radiators 22, 25
The shape, especially the protrusion at both left and right ends, becomes smaller.

As a result, the outline of the car body, that is, the cowling (symbol A in Figure 2 and code B in Figure 3) becomes smooth and streamlined due to the reduced protrusion of the radiator, which reduces the aerodynamic resistance of the car body to the airflow. It is possible to reduce the In addition, the center of gravity of the vehicle is lowered, further increasing stability, and at the same time, the bank angle is sufficient, making it possible to drive with a large lean angle when cornering.

Furthermore, the air intake system of the engine can be cooled by the running wind that passes between the upper and lower radiators, and it is possible to prevent the intake system from being heated and deteriorating the intake efficiency.

In this way, according to the radiator of the present invention, the aerodynamic resistance to the airflow of the vehicle body is reduced, so
In particular, it is possible to improve the running performance of competitive motorcycles.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a motorcycle having a radiator according to the present invention, FIG. 2 is a front view of the radiator section taken from the direction of arrow Z in FIG. This is an instruction diagram. Explanation of symbols of main parts, 1...Steering head pipe, 3...Upper tube, 4...Down tube, 8...Water-cooled engine, 22, 25
...radiator.

Claims (1)

[Scope of Claims] 1. A radiator for a motorcycle equipped with a water-cooled engine, which is divided into an upper part and a lower part with the intake system of the water-cooled engine in between, and is fixed to a down tube of a vehicle body frame, and A radiator characterized in that the lower portion projects downward from the lowest end of the down tube. 2. The radiator according to claim 1, wherein the lower portion has a width smaller at the lower end than at the upper end.