JP3797001B2 - Motorcycle engine cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motorcycle in which a radiator is installed in front of a water-cooled engine. More specifically, the present invention relates to an engine cooling device for a motorcycle with improved air bleedability in a cooling water passage and maintenance performance such as cooling water replenishment. Is.
[0002]
[Prior art]
FIG. 7 is a left side view showing an example of the surroundings of a motorcycle equipped with a water-cooled engine. In general, in an engine 80 of a motorcycle, a cylinder block 82 and a cylinder head 83 are inclined forward on the upper surface of a crankcase 81, and a water pump 84 is provided on one side of the crankcase 81. Such an engine 80 is mounted on the front portion of the vehicle body frame 85, and a radiator 86 is installed in front of the engine 80. A fuel tank (not shown) is placed above the engine 80.
[0003]
An outlet passage 87 extends from a water jacket (not shown) formed inside the cylinder head 83 of the engine 80, and the other end is connected to the radiator 86. On the other hand, an inlet passage 88 extends from the water jacket inside the cylinder block 82, and the other end is connected to the discharge port of the water pump 84. Further, the other end of the suction passage 89 extending from the suction port of the water pump 84 is connected to the radiator 86.
[0004]
Since a cooling water passage (not shown) serving as a water jacket outlet of the cylinder head 83 needs to be formed on the rear side in order to make the engine compact, the outlet passage 87 is inevitably led out from the rear surface of the cylinder head 83. The outlet passage 87 extends once upward from the cylinder head 83 and is connected to the radiator 86 through the head cover 90 attached on the cylinder head 83.
[0005]
The reason why the outlet passage 87 is passed above the head cover 90 is that if the outlet passage 87 extends forward through the side of the cylinder head 83, the outlet passage 87 protrudes in the vehicle width direction and the vehicle width increases. Because there is a concern to do. In particular, in the case of a cradle-type body frame 85 as shown in FIG. 7 or a body frame in which a frame pipe passes close to the side of the cylinder head 83, such as a diamond-type frame, the outlet passage 87 In order to secure the insertion space, it is necessary to widen the space between the left and right frame pipes, which necessitates an increase in the size and weight of the entire vehicle body.
[0006]
In addition, in models where the front half of the vehicle body is covered with a cowling, the cowling covers the outer side of the frame pipe, which is widened as described above, so that the entire width of the cowling is expanded, and the aerodynamic performance and styling of the motorcycle are expanded. Deteriorates significantly. Therefore, the above-described adverse effect is avoided by passing the outlet passage 87 above the head cover 90.
[0007]
By the way, the cooling water replenishment cap 91 for injecting cooling water into such a cooling device and simultaneously venting the entire cooling water path must be provided at the top of the entire cooling water path. The position is necessarily near the top of the outlet passage 87.
[0008]
[Problems to be solved by the invention]
However, if the cooling water replenishment cap 91 is provided at the top of the outlet passage 87, which is the uppermost part of the cooling water path, the fuel tank is positioned immediately above the cooling water replenishment cap 91, and the cooling water is replenished. Since the fuel tank must be removed or lifted upward each time, the workability is very poor. For example, if the outlet passage 87 is once extended downward from the extension portion and connected to the radiator 86, the problem caused by the outlet passage 87 protruding in the vehicle width direction as described above can be solved. This makes it difficult to vent the cooling water passage.
[0009]
The present invention has been made to solve the above problems, and includes a vehicle body frame through which a frame pipe passes close to the cylinder head side of the engine, and a motorcycle in which the front half of the vehicle body is covered with a cowling. To provide an engine cooling device for a motorcycle that can reliably release air from the cooling water path without increasing the size of the vehicle body or expanding the cowling width, and has good workability when refilling the cooling water. With the goal.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an engine cooling device for a motorcycle according to the present invention is a water-cooled engine in which a cylinder block and a cylinder head are inclined forward on the upper surface of a crankcase. Is mounted on the front portion of the vehicle body frame, a radiator is installed in front of the engine, and an outlet passage extending from a cooling water outlet provided on the rear surface of the cylinder head is connected to the radiator. The other end of the outlet passage connected at one end to the cooling water outlet provided at the uppermost part of the entire engine cooling water path is temporarily extended downward from the cooling water outlet to the side of the cylinder block on the side where the cam chain housing is provided. In addition, it contacts the radiator through the lower part of the frame pipe. To one, between the cooling water outlet and the radiator, and the outlet passage connecting an air vent hose rerouting, after once extended upward the air vent hose from the cooling water outlet, and the cam chain housing Is connected to the upper part of the radiator at a position higher than the outlet passage through the side surface of the cylinder head on the opposite side and the frame pipe, and a cooling water replenishing cap for air bleeding is provided at the upper part of the radiator.
[0012]
When the engine cooling device for a motorcycle is configured as in claim 1, the cooling water outlet portion is the uppermost portion of the cooling water passage on the engine side, and the air in the cooling water passage gathering here passes through the air bleeding hose. The cooling water replenishment cap provided at the upper part of the radiator is surely discharged to the outside. Therefore, the outlet passage can be freely piped without considering air venting, and a layout that does not protrude in the vehicle width direction is possible, so the vehicle body can be increased in size and cowling width due to the protrusion of the outlet passage. Can be prevented. In addition, since the cooling water replenishment cap is provided on the radiator, workability at the time of cooling water replenishment is good. Since the air bleeding hose can be made much thinner than the outlet passage, it does not protrude in the vehicle width direction and does not get in the way.
[0013]
In general, the distance between the left and right side surfaces of the cylinder head and the frame pipe is larger on the anti-cam chain housing side than on the cam chain housing side. For this reason, if an air bleeding hose is provided on the side opposite to the cam chain housing , there is no need to increase the distance between the cylinder head and the frame pipe in order to pass the air bleeding hose. I can prevent it.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a left side view showing an example of a motorcycle to which an embodiment of the present invention is applied.
[0015]
The motorcycle 1 has a front wheel 4 supported by a front fork 3 that is pivotally supported by a head pipe 2 a of a body frame 2, and a swing that supports a rear wheel 6 on a pivot shaft 5 that is installed at the center lower part of the body frame 2. The arm 7 is pivotally supported.
[0016]
An engine 8 is mounted on the lower half of the front half of the body frame 2, a fuel tank 9 is installed above the engine 8, and a seating seat 10 and a pillion seat 11 are placed behind the fuel tank 9. The front half of the motorcycle 1 is covered with a streamlined cowling 12 to reduce air resistance and improve the appearance during traveling.
[0017]
2, 3 and 4 are a left side view, a front view and a plan view around the engine 8, respectively. The engine 8 is, for example, a water-cooled parallel 4-cylinder DOHC engine, and a cylinder block 14, a cylinder head 15, and a head cover 16 are tilted forward on the upper surface of the front portion of the crankcase 13. A cam chain housing 17 (see FIGS. 3 and 4) is provided on, for example, the right side surface of these members 14, 15 and 16, and a cam chain for driving a camshaft (not shown) is accommodated therein.
[0018]
By the way, the body frame 2 is a diamond-type frame that uses the engine 8 itself as a strength member, and includes a pair of left and right thick frame pipes 2b extending obliquely downward and rearward from the head pipe 2a. It is located close to the sides of the cylinder head 15 and the head cover 16.
[0019]
As shown in FIG. 1, a fuel injection device 19 and an air cleaner 20 are connected to the rear portion of the cylinder head 15, and the upper portion of the fuel injection device 19 and the air cleaner 20 are in a recess (not shown) provided inside the fuel tank 9. It is stored in. Further, as shown in FIG. 3, four exhaust ports 21 are connected to the front surface of the cylinder head 15 in the vehicle width direction, and four exhaust pipes 22 are connected thereto. These exhaust pipes 22 hang down from the exhaust port 21 and curve backward, and are connected to the exhaust muffler 25 via the collecting pipe 23 and the muffler pipe 24.
[0020]
Further, a radiator 27 for exchanging heat of the cooling water is installed in front of the engine 8, and an electric fan 28 is provided on the rear surface thereof. The radiator 27 is cooled by the traveling wind blown from the front when the motorcycle 1 is traveling. However, when the motorcycle 1 cannot be cooled by the traveling wind, such as when the motorcycle 1 is stopped, the electric fan 28 is activated to assist the radiator 27. Cooling. Below the radiator 27, an oil cooler 29 that is also cooled by traveling wind is installed.
[0021]
As shown also in FIG. 5, a water pump 31 is installed on the left side of the crankcase 13 of the engine 8, and a cooling water reservoir tank 32 is attached in the vicinity thereof. A cooling water inlet 33 is provided on the rear surface of the cylinder block 14, and a cooling water outlet 34 is provided on the rear surface of the cylinder head 15. The cooling water inlet 33 serves as an inlet for cooling water to a water jacket (not shown) formed inside the cylinder block 14, and the cooling water outlet 34 serves as an outlet for cooling water from the water jacket inside the cylinder head 15. The cylinder block 14 and the water jacket of the cylinder head 15 communicate with each other.
[0022]
A hose-like inlet passage 35 extends from the cooling water inlet 33, and the other end is connected to the discharge port 31 a of the water pump 31. Similarly, a hose-like outlet passage 36 extends from the cooling water outlet 34, and the other end is connected to a radiator inlet 27a provided on, for example, the upper right front surface of the radiator 27 (see also FIG. 6). Further, a suction passage 38 extending from the suction port 31 b of the water pump 31 is connected to a radiator outlet 27 b provided on the lower left rear surface of the radiator 27. On the upper surface of the radiator 27, for example, a cooling water replenishment cap 39 that also serves as an air vent is provided on the right side thereof.
[0023]
By the way, from the cooling water outlet 34 on the rear surface of the cylinder head 15, a thin air bleeding hose 41 is extended separately from the outlet passage 36, and the other end is connected to the upper portion of the radiator 27. The air bleeding hose 41 is once extended upward from the cooling water outlet 34 and connected to the radiator 27 through a position higher than the outlet passage 36.
[0024]
That is, as shown in FIG. 4, the air bleeding hose 41 extends from the cooling water outlet 34 and then extends substantially horizontally toward the left side, for example, and the cylinder head 15 on the opposite side (left side) from the cam chain housing 17. (Head cover 16) Extends forward through the side and the left frame pipe 2b of the vehicle body frame 2 and further passes right through the front of the cylinder head 15 and the head cover 16 to the upper right rear surface of the radiator 27 (radiator inlet). 27a). The air vent hose 41 is preferably disposed so as to continue to rise from the coolant outlet 34.
[0025]
The reservoir hose 42 extending from the cooling water reservoir tank 32 is connected to the vicinity of the cooling water replenishing cap 39 of the radiator 27 through the right side of the engine 8, for example, and the reservoir overflow hose 43 extending from the cooling water reservoir tank 32 is also downward It extends and the other end is open.
[0026]
The radiator 27, the water pump 31, the cooling water reservoir tank 32, the cooling water inlet 33, the cooling water outlet 34, the inlet passage 35, the outlet passage 36, the suction passage 38, the cooling water replenishing cap 39, and the air hose described above. 41 and the like are elements constituting the engine cooling device according to the present invention.
[0027]
When the engine 8 is operated, the water pump 31 is driven, and the cooling water is supplied from the radiator 27 → the suction passage 38 → the water pump 31 → the inlet passage 35 → the cooling water inlet 33 → the water jacket in the cylinder block 14 → the water in the cylinder head 15. The engine 8 is cooled by the cooling water that circulates in the order of the jacket → the cooling water outlet 34 → the outlet passage 36 → the radiator 27 and heat-exchanged by the radiator 27.
[0028]
In this engine cooling device, since the cooling water outlet 34 is the uppermost part of the entire cooling water path on the engine 8 side, air (bubbles) contained in the cooling water path gathers in the cooling water outlet 34, from which the air vent hose It passes through 41 and escapes to the top of the radiator 27 and is discharged from the cooling water replenishment cap 39 to the outside. Then, the cooling water is replenished from the cooling water reservoir tank 32 correspondingly. Since the air bleeding hose 41 extends upward from the cooling water outlet 34 once and passes through a position higher than the outlet passage 36 and is connected to the upper portion of the radiator 27, the air bleeding is reliably performed.
[0029]
As described above, since the air bleeding hose 41 is surely ventilated, the piping layout of the outlet passage 36 does not need to consider the air bleeding property, and the outlet passage 36 can be freely piped. For example, as in this embodiment, if the outlet passage 36 is once extended downward from the cooling water outlet 34 and connected to the radiator 27 through the right side of the cylinder block 14 and the lower side of the frame pipe 2b, there is a relatively large space. An outlet passage 36 is provided at a portion to prevent the outlet passage 36 from projecting in the vehicle width direction, thereby preventing an increase in the overall width of the vehicle body frame 2 and an increase in the width of the cowling 12 due to the projection of the outlet passage 36. .
[0030]
On the other hand, the air vent hose 41 is much narrower than the outlet passage 36, and the air vent hose 41 is the side of the cylinder head 15 opposite to the cam chain housing 17 (here, the left side) and the frame pipe on the left side of the body frame 2. 2b. Since the space between the left side surface of the cylinder head 15 and the left frame pipe 2b is wider than the right side due to the absence of the cam chain housing 17, the air bleeding hose 41 is disposed on the side opposite to the cam chain housing 17 in this way. Therefore, there is no need to particularly widen the distance between the cylinder head 15 and the frame pipe 2b in order to pass the air bleeding hose 41, and in this respect as well, the enlargement of the vehicle body and the increase in the width of the cowling 12 can be effectively suppressed.
[0031]
Further, in this engine cooling device, since the coolant replenishment cap 39 is provided on the upper portion of the radiator 27, even if the front half of the vehicle body is covered with the cowling 12 as in the motorcycle 1, the fuel tank 9 is provided. The cooling water replenishment cap 39 can be easily attached and detached without removing it, and workability at the time of cooling water replenishment is good.
[0032]
In this embodiment, the engine 8 is a parallel 4-cylinder DOHC engine. However, the present invention is not limited to this type, and the above configuration can be applied to other water-cooled engines.
[0033]
【The invention's effect】
As described above, in the motorcycle engine cooling device according to the present invention, the cooling water outlet extending from the outlet passage and the radiator are connected by an air bleeding hose that is separate from the outlet passage. The air vent hose was extended upward from the cooling water outlet and then connected to the upper part of the radiator through a position higher than the outlet passage, and a cooling water replenishing cap was also provided at the upper part of the radiator, so the piping layout of the outlet passage Liberalization and prevention of enlargement of the vehicle body and expansion of the cowling width due to the outlet passage projecting in the width direction of the vehicle, while ensuring that the cooling water passage is vented, and the cooling water replenishment cap is located on the top of the radiator To improve workability when cooling water is replenished. It is possible.
[0034]
In the motorcycle engine cooling apparatus according to the present invention, when the cam chain housing of the engine is provided on one side of the engine, the air bleeding hose is disposed on the opposite side of the cylinder head from the cam chain housing. Since it is arranged between the side and the frame pipe of the body frame, there is no need to widen the distance between the cylinder head and the frame pipe in order to install the air bleeding hose. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a left side view showing an example of a motorcycle to which an embodiment of the present invention is applied.
FIG. 2 is a left side view around the engine.
FIG. 3 is a front view around the engine.
FIG. 4 is a plan view around an engine showing an embodiment of the present invention.
FIG. 5 is a schematic left side view showing the overall configuration of the engine cooling device.
FIG. 6 is a right side view near a radiator.
FIG. 7 is a schematic left side view showing the overall configuration of a conventional engine cooling apparatus.
[Explanation of symbols]
1 Motorcycle 2 Body frame 2b Frame pipe 8 Engine
13 Crankcase
14 cylinder block
15 cylinder head
17 Cam chain housing
27 Radiator
31 Water pump
32 Cooling water reservoir tank
33 Cooling water inlet
34 Cooling water outlet
35 Inlet passage
36 Outlet passage
38 Suction passage
39 Cooling water replenishment cap
41 Air bleeding hose

Claims (1)

A water-cooled engine with the cylinder block and cylinder head tilted forward on the upper surface of the crankcase is mounted on the front of the vehicle body frame, and a radiator is installed in front of the engine, and is installed on the rear surface of the cylinder head. In the motorcycle engine cooling device in which the outlet passage extending from the cooling water outlet is connected to the radiator, the other end of the outlet passage connected to the cooling water outlet provided at one end at the top of the entire engine cooling water path Extending downward from the cooling water outlet and connecting to the radiator through the side of the cylinder block on the side where the cam chain housing is provided and under the frame pipe , the outlet passage is between the cooling water outlet and the radiator. Another route air Connected by comes hose, after once extended upward the air vent hose from the cooling water outlet, radiator upper at a position higher than the outlet passageway through between the opposite side of the cylinder head side and the frame pipe and the cam chain housing And a cooling water replenishing cap that also serves as an air vent at the top of the radiator.

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