JPH11141335A - Engine cooling system of motor-bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To balance a temperature of a front cylinder with that of a rear cylinder. SOLUTION: The thermostats 19A, 19B are separately mounted on a cooling water outflow port 97 of a front cylinder 90, and a cooling water outflow port 97 of a rear cylinder 91 of a water cooled two cylinder V-engine of a motor-bicycle. Whereby the opening and closing temperatures of the thermostats 19A, 19B can be easily agreed with each other or can be easily changed. Accordingly the water temperature of the front cylinder 90 and that of the rear cylinder 91 can be easily balanced with a simple structure, and the combustion state can be remarkably stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle engine cooling system for balancing water temperatures of front and rear cylinders such as a V-type water-cooled two-cylinder engine.

[0002]

2. Description of the Related Art A conventional motorcycle engine cooling system uses a water pump 93 to cool a V-type water-cooled two-cylinder engine 9 by cooling water (see arrows) cooled by a radiator 95 as shown in FIG. , Front cylinder 9
0 and the rear cylinder 91, the cylinder head 96, and the single thermostat 19 in the inside of the conduction 26 are sequentially passed to the radiator 95 again to cool the V-type water-cooled two-cylinder engine 9.

[0003]

The conventional engine cooling device for a motorcycle is constructed as described above, and the front cylinder 90 is apt to receive cooling air (see the arrow in FIG. 9). Therefore, there is a problem that the temperature of the front cylinder 90 and the rear cylinder 91 cannot be balanced.

The present invention has been made in view of the above-described conventional problems, and has as its object to provide an engine cooling device for a motorcycle that can balance the temperature between a front cylinder and a rear cylinder.

[0005]

According to a first aspect of the present invention, in order to achieve the above object, a cooling liquid is supplied to a passage inside an engine to cool the engine. A V-type water-cooled engine having a rear cylinder and a substantially V-shape when viewed from the side is characterized in that a thermostat is attached to each of a coolant passage of the front cylinder and a coolant passage of the rear cylinder. It is preferable that the set temperature for opening the thermostat of the rear cylinder is set lower or equal to the set temperature for opening the thermostat of the front cylinder.

Here, the "V-type water-cooled engine" in the claims may be a two-cylinder engine or an engine having two or more cylinders. The “coolant passage” includes at least a coolant outlet of each cylinder and a conductor.

According to the first aspect of the present invention, since the thermostat valves are separately set in the respective coolant passages of the front cylinder and the rear cylinder, the opening / closing temperatures of the plurality of thermostat valves can be individually set. Therefore, the temperature balance between the front cylinder and the rear cylinder can be easily achieved.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the motorcycle engine cooling device according to the present embodiment, thermostats 19A and 19B are attached to a cooling water outlet 97 of a front cylinder 90 and a cooling water outlet 97 of a rear cylinder 91 of a V-type water-cooled two-cylinder engine 9 of the motorcycle 1, respectively. Like that.

The motorcycle 1 has a highly rigid and lightweight diamond frame made of an aluminum alloy, and the diamond frame has a separable seat rail frame.
At the front of the diamond frame, a head pipe is provided at an angle, and a cylindrical double-acting front fork 2 is pivotally supported on the head pipe via a bearing so as to be steerable.
A separate handle 3 and the like are mounted on an upper portion of the front fork 2, and a front wheel 4 and a front brake 5 are mounted on a lower inner tube (see FIGS. 1 to 4).

As shown in FIG. 1, a cowling 7 having a screen 6 is mounted on a front portion of the vehicle. Air cowls 8 are provided on both right and left sides of the cowling 7, respectively. When traveling wind is introduced from each air duct 8 into the air cleaner 92, the inside of the air cleaner 92 is pressurized, so that the intake efficiency is improved and the output is improved.

Below the center of the diamond frame,
As shown in FIGS. 1 and 2, the V-type water-cooled two-cylinder engine 9
A fuel tank 10 having a built-in filter and the like is mounted above the diamond frame from the front to the center. A lightweight swing arm 11 made of aluminum alloy is pivotally supported via a damping unit at a pivot portion at a rear portion of the diamond frame, and a rear wheel 12 is supported at a rear portion of the swing arm 11 via a bearing. In addition, a hydraulic rear brake 13 is mounted. Further, mufflers 15 connected to the lower part of the V-type water-cooled two-cylinder engine 9 via connecting pipes 14 are attached to the lower left and right sides of the rear part of the diamond frame.

A plurality of frame covers 1 for reducing air resistance are provided from the center to the rear of the diamond frame.
6 are mounted in combination. The seat 17 is located above the frame cover 16 from the center to the rear.
And a pillion sheet 18 are detachably mounted (see FIGS. 1 and 2).

As shown in FIGS. 5 and 6, the V-type water-cooled two-cylinder engine 9 has a structure in which a front cylinder 90 and a rear cylinder 91 are shifted from each other by about 90 °. Water pump 9
3 and an oil cooler 94, and an inclined radiator 95 are mounted at the front. A cylinder head 96 is mounted on the front cylinder 90 and the rear cylinder 91 via a gasket, and a cooling water outlet 97 is opened in the cylinder head 96. Each cooling water outlet 97 and the radiator 95 are connected to an upper part. It is connected via a hose 98. A water jacket (not shown) is formed around the front cylinder 90 and the rear cylinder 91 so as to surround them.

The water pump 93 is composed of a volute pump and is mounted on the front side of the clutch cover.
Cooling water driven by idle shaft (for example, Long Life Coolant (LLC) which has rust prevention effect and freeze prevention effect)
It is used to circulate). Also,
The radiator 95 includes an upper tank, a lower tank, a water tube, and a bimetallic electric fan 99, and functions to cool high-temperature cooling water with air.

Further, thermostats 19A and 19B
As shown in FIG. 7, are mounted directly on the cooling water outlets 97 of the front cylinder 90 and the rear cylinder 91, and are connected to a radiator 95 via a Y-shaped upper hose 98. Each thermostat 19A, 19B
A sealing case 22 filled with wax 21 is fitted into an opening at the center of the lower part of a case 20 as its main body.
A bar 23 penetrating the upper part of the case 20 is reciprocally supported by the enclosing case 22, and an on-off valve 24 having a small bypass hole is fitted to this bar.
An on-off valve coil spring 25 is fitted and elastically mounted, and is configured in a wax pellet type.

Each of the thermostats 1 configured as described above
9A and 19B open and close the water channel by expansion and contraction of the wax 21, and function to control the flow of the cooling water from the lower part to the upper part. In the thermostats 19A and 19B, the valve opening set temperature of the thermostat 19B of the rear cylinder 91 is set lower than or equal to the valve opening set temperature of the thermostat 19A of the front cylinder 90 in consideration of the influence of cooling air. .

In the above configuration, when the impeller of the water pump 93 is driven, the cooling water indicated by the arrow is supplied from the water jacket of the front cylinder 90 to the cylinder head 96, the cooling water outlet 97, the thermostat 19A for the front cylinder 90, and the upper hose 98. , A radiator 95, and a lower hose of the radiator 95, and flow into the water pump 93. Almost simultaneously with this, the cylinder head 96, the cooling water outlet 97, the rear cylinder 91
And flows into the water pump 93 through the thermostat 19B, the upper hose 98, the radiator 95, and the lower hose in this order. Thus, the water pump 9
The cooling water flowing into 3 is pressurized and circulates again inside the V-type water-cooled two-cylinder engine 9.

According to the above configuration, the front cylinder 90
Since the thermostats 19A and 19B are independently attached to the respective cooling water outlets 97 of the and the rear cylinder 91, the opening and closing temperature settings of the thermostats 19A and 19B can be easily made the same or changed. Therefore, the water temperature balance between the front cylinder 90 and the rear cylinder 91 can be extremely easily achieved with a simple configuration, and the combustion state can be remarkably stabilized. Further, since the thermostats 19A and 19B are mounted inside the V-type water-cooled two-cylinder engine 9, a remarkable compactness of the structure can be expected and the appearance can be adjusted.

FIG. 8 shows a second embodiment of the present invention. In this case, a thermostat 19A for the front cylinder 90 and a thermostat 19A for the rear cylinder 91 are provided inside the Y-shaped conductor 26. Thermostat 19
B and B are separately mounted. The other parts are the same as those in the above-described embodiment, and the description is omitted.

In this embodiment, the same operation and effect as those of the above-described embodiment can be expected, and there is no need to change the structure of the V-type water-cooled two-cylinder engine 9 at all. So it's really convenient.

In the above-described embodiment, the motorcycle 1 shown in FIGS. 1 to 4 has been described. However, the present invention is not limited to this, and can be applied to other types of motorcycle 1 as appropriate. The water jacket may be of a wet liner type or a dry liner type. The radiator 95 may be either a vertical flow type or a cross flow type. Further, the shape, structure, number, etc. of the conductor 26 and the thermostats 19A, 19B can be appropriately increased or decreased.

[0022]

As described above, according to the first aspect of the present invention, there is a special effect that the temperature of the front cylinder and the rear cylinder of the engine can be balanced. Further, it is possible to reduce the warm-up time in which the coolant temperature of the front cylinder rises to the set fluid temperature as compared with the related art. Furthermore, according to the second aspect of the present invention, it is possible to suppress a rise in the temperature of the rear cylinder, which tends to rise more than the front cylinder, so as to exceed the designed liquid temperature.

[Brief description of the drawings]

FIG. 1 is an overall plan view showing an embodiment of a motorcycle engine cooling device according to the present invention.

FIG. 2 is an overall side view showing an embodiment of a motorcycle engine cooling device according to the present invention.

FIG. 3 is an overall front view showing the embodiment of the motorcycle engine cooling device according to the present invention.

FIG. 4 is an overall rear view showing the embodiment of the motorcycle engine cooling device according to the present invention.

FIG. 5 is a side view showing an engine in the embodiment of the motorcycle engine cooling device according to the present invention.

FIG. 6 is a front view showing an engine in the embodiment of the engine cooling device for a motorcycle according to the present invention.

FIG. 7 is an explanatory sectional view showing an embodiment of a motorcycle engine cooling device according to the present invention.

FIG. 8 is a sectional explanatory view showing another embodiment of the motorcycle engine cooling device according to the present invention.

FIG. 9 is an explanatory sectional view showing a conventional engine cooling device for a motorcycle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 9 V-type water-cooled two-cylinder engine 19A Thermostat 19B Thermostat 20 Case 21 Wax 22 Enclosure case 23 Bar 24 Open / close valve 25 Coil spring 26 Conduction (coolant passage) 90 Front cylinder 91 Rear cylinder 92 Air cleaner 93 Water pump 94 Oil cooler 95 Radiator 96 Cylinder head 97 Coolant outlet (coolant passage) 98 Upper hose

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02B 61/02 F02B 61/02 E

Claims (2)

[Claims] 1. A motorcycle engine cooling device for cooling a motorcycle by flowing a coolant through an internal passage of the engine, wherein the engine is provided with a front cylinder and a rear cylinder in a substantially V-shape in a side view. A motorcycle engine cooling device, wherein thermostats are respectively attached to a coolant passage of the front cylinder and a coolant passage of the rear cylinder. 2. The motorcycle engine cooling device according to claim 1, wherein the set temperature of the thermostat of the rear cylinder is set lower than or equal to the set temperature of the thermostat of the front cylinder.