JP2000248938A - Engine cooling device for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform air bleed in a cooling water route, and improve workability when cooling water is replenished, without enlargement in size of a vehicle body, expansion of a cowling width, etc., even in a motorcycle provided with a vehicle body frame with a frame pipe passing adjacently in the sideward of a cylinder head of an engine to cover the front half part of the vehicle body with a cowling. SOLUTION: The part between a cooling water outlet 34 provided in a rear surface of a cylinder head of an engine 8, and a radiator 27 is connected by an air bleed hose 41 of a route different from an outlet passage 36, the air bleed hose 41, after extended once upward from the cooling water outlet 34, is connected to an upper part of the radiator 27 through a position higher than the outlet passage 36, and a cooling water replenishing cap 39 commonly used as air bleed is provided in the upper part of the radiator 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle having a radiator installed in front of a water-cooled engine,
More specifically, the present invention relates to an engine cooling device for a motorcycle, which has improved maintainability such as air bleeding in a cooling water path and replenishment of cooling water.

[0002]

2. Description of the Related Art FIG. 7 is a left side view showing an example around a motorcycle equipped with a water-cooled engine. In general, an engine 80 of a motorcycle has a cylinder block 82 and a cylinder head 83 installed on a top surface of a crankcase 81 with a forward inclination, and a water pump 84 provided on one side surface of the crankcase 81. Such an engine 80 is mounted on the front part of the body frame 85, and a radiator 86 is installed in front of the engine 80. A fuel tank (not shown) is mounted above the engine 80.

An outlet passage 87 extends from a water jacket (not shown) formed inside a cylinder head 83 of the engine 80, and the other end is connected to a radiator 86. On the other hand, an inlet passage 88 extends from a water jacket inside the cylinder block 82, and the other end is connected to a discharge port of a water pump 84. Further, a suction passage extending from a suction port of the water pump 84.
The other end of 89 is connected to a radiator 86.

Since a cooling water passage (not shown) serving as an outlet of the water jacket 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 temporarily extends upward from the cylinder head 83, and is connected to a radiator 86 through above a head cover 90 mounted on the cylinder head 83.

The reason why the outlet passage 87 is passed above the head cover 90 is as follows.
This is because when the 87 is extended forward through the side of the cylinder head 83, there is a concern that the outlet passage 87 protrudes in the vehicle width direction to increase the vehicle width. 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 an insertion space, it is necessary to increase the distance 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 a vehicle type in which 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 aerodynamics of the motorcycle are increased. Performance and styling deteriorate significantly. Therefore, outlet passage
By passing the 87 over the head cover 90, the above adverse effects are avoided.

By the way, a cooling water replenishing cap 91 for injecting cooling water into such a cooling device and simultaneously bleeding air from the entire cooling water path needs to be provided at the top of the entire cooling water path. The position is necessarily near the top of the outlet passage 87.

[0008]

However, when the cooling water replenishing 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 located immediately above the cooling water replenishing cap 91. When refilling the cooling water, the fuel tank must be removed or lifted up each time, so the workability is very poor. Note that, for example, if the outlet passage 87 is temporarily extended downward from its extension to connect to the radiator 86, the problem caused by the outlet passage 87 projecting in the vehicle width direction as described above can be solved. This makes it difficult to release air from the cooling water path.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a motorcycle is provided with a body frame through which a frame pipe passes close to a side of a cylinder head of an engine, and a front half of the body is covered with a cowling. Also, a motorcycle engine cooling device that can reliably release air from the cooling water path and has good workability when replenishing cooling water without increasing the size of the car body or expanding the cowling width, etc. The purpose is to provide.

[0010]

According to a first aspect of the present invention, there is provided a motorcycle engine cooling apparatus according to the present invention, wherein a cylinder block and a cylinder head are inclined forward on an upper surface of a crankcase. The water-cooled engine installed at the front of the body frame is installed,
A radiator is provided in front of the engine, and an outlet passage extending from a cooling water outlet provided on a rear surface of the cylinder head is connected to the radiator. In a motorcycle engine cooling device, a radiator is provided between the cooling water outlet and the radiator. Is connected to the above-mentioned outlet passage by an air vent hose which is different from the outlet passage.The air vent hose is once extended upward from the cooling water outlet, and then connected to the upper portion of the radiator through a position higher than the outlet passage, and the air is exhausted to the upper portion of the radiator. A cooling water replenishing cap was also provided for double use.

Further, in order to achieve the above object, a motorcycle engine cooling apparatus according to the present invention is provided.
As described in the above, when a cam chain housing is provided on one side of the engine, the air release hose is connected to a side of the cylinder head opposite to the cam chain housing and a frame pipe of the body frame. Arranged through.

When the engine cooling device for a motorcycle is constructed as in claim 1, the portion of the cooling water outlet is the uppermost portion of the cooling water passage on the engine side, and the air in the cooling water passage gathering here is vented. The water is reliably discharged from the cooling water replenishing cap provided on the radiator through the hose. Therefore, the outlet passage can be freely laid without considering the air bleeding property, and the layout can be made such that the outlet passage does not protrude in the vehicle width direction. Can be prevented from being extended. Further, since the cooling water replenishing cap is provided at the upper part of the radiator, workability at the time of replenishing the cooling water is good. Since the air release hose can be made much thinner than the outlet passage, it does not protrude in the vehicle width direction and does not become an obstacle.

In general, the distance between the left and right side surfaces of the cylinder head and the frame pipe is greater on the side opposite to the cam chain housing than on the side of the cam chain housing.
For this reason, if the air release hose is provided on the side opposite to the cam chain housing as in claim 2, it is not necessary to particularly widen the interval between the cylinder head and the frame pipe to pass the air release hose, so that the size of the vehicle body can be increased. This prevents the cowling width from expanding.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a left side view showing an example of a motorcycle to which one embodiment of the present invention is applied.

The motorcycle 1 has a body frame 2
A front arm 4 is supported on a front fork 3 pivotally supported by a head pipe 2a, and a swing arm 7 supports a rear wheel 6 on a pivot shaft 5 installed at the lower center of the body frame 2.
Is supported.

An engine 8 is mounted on the lower front half of the body frame 2, a fuel tank 9 is installed above the engine 8, and a seat 10 and a pillion seat 11 are placed behind the fuel tank 9. The first half of the motorcycle 1 is covered with a streamlined cowling 12 to reduce the air resistance during traveling and improve the appearance.

FIGS. 2, 3 and 4 each show an engine 8
It is a left side view, a front view, and a plan view of the surroundings. Engine 8
Is, for example, a DOHC engine of a water-cooled parallel 4-cylinder,
A cylinder block is provided on the upper surface of the front of the crankcase 13.
14, a cylinder head 15, and a head cover 16 are installed to be inclined forward. A cam chain housing 17 (see FIGS. 3 and 4) is provided, for example, on the right side of these members 14, 15, and 16 and houses a cam shaft for driving a cam shaft (not shown).

Incidentally, the body frame 2 is provided with an engine 8
It is a diamond type frame that utilizes itself as a strength member, and has a pair of left and right thick frame pipes 2b extending obliquely downward from the head pipe 2a, and these frame pipes 2b are located on the sides of the cylinder head 15 and the head cover 16 of the engine 8. Located close to.

As shown in FIG. 1, a fuel injection device 19 and an air cleaner 20 are connected to a rear portion of the cylinder head 15. An upper portion of the fuel injection device 19 and the air cleaner 20 are provided inside the fuel tank 9. Not fit into the recess. Further, as shown in FIG. 3, four exhaust ports 21 are continuously provided in the vehicle width direction on the front surface of the cylinder head 15, and four exhaust pipes 22 are connected thereto. These exhaust pipes 22 hang down from the exhaust port 21 and curve rearward, and are connected to an exhaust muffler 25 via a collecting pipe 23 and a muffler pipe 24.

A radiator 27 for exchanging heat with cooling water is provided in front of the engine 8, and an electric fan 28 is provided on a rear surface thereof. The radiator 27 is cooled by the traveling wind blown from the front when the motorcycle 1 travels. However, when cooling by the traveling wind cannot be expected, such as when the motorcycle 1 is stopped, the electric fan 28 operates to activate the radiator 27.
Is additionally cooled. In addition, below the radiator 27, an oil cooler 29 that is also cooled by the traveling wind is installed.

As shown in FIG. 5, a water pump 31 is provided on the left side of the crankcase 13 of the engine 8.
A cooling water reservoir tank 32 is mounted 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 a cooling water inlet to a water jacket (not shown) formed inside the cylinder block 14,
The cooling water outlet 34 serves as an outlet for cooling water from a water jacket inside the cylinder head 15. In addition,
The water jackets of the cylinder block 14 and the cylinder head 15 communicate with each other.

A hose-shaped inlet passage 35 extends from the cooling water inlet 33, and the other end thereof is connected to the water pump 31.
Is connected to the discharge port 31a. Also, cooling water outlet
A hose-like outlet passage 36 extends from 34, and the other end is connected to a radiator inlet 27a provided on the upper right front surface of the radiator 27 (see also FIG. 6). Furthermore, the suction port of the water pump 31
A suction passage 38 extending from 31b is connected to a radiator outlet 27b provided on the lower left rear surface of the radiator 27. On the upper surface of the radiator 27, for example, a cooling water replenishing cap 39 also serving as an air vent is provided on the right side thereof.

From the cooling water outlet 34 on the rear surface of the cylinder head 15, a thin air vent hose 41 extends separately from the outlet passage 36, and the other end is connected to the upper part of the radiator 27. The air release hose 41 is temporarily extended upward from the cooling water outlet 34, and is connected to the radiator 27 through a position higher than the outlet passage 36.

That is, as shown in FIG.
41 extends from the cooling water outlet 34 and then extends substantially horizontally, for example, to the left, so that the cam chain housing 17
Side of the cylinder head 15 (head cover 16) on the opposite side (left side) and the frame pipe 2 on the left side of the body frame 2
b and extends forward, and further the cylinder head
15 and the right side of the radiator 27 (the radiator inlet 27
a). The air bleeding hose 41
Is preferably arranged to keep rising from the cooling water outlet 34.

A reservoir hose 42 extending from the cooling water reservoir tank 32 is connected, for example, to the vicinity of the cooling water replenishing cap 39 of the radiator 27 through the right side of the engine 8 and also has a reservoir overflow hose 43 extending from the cooling water reservoir tank 32. Extends downward and is open at the other end.

As described above, 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 3
5. The outlet passage 36, the suction passage 38, the cooling water replenishment cap 39, the air release hose 41, and the like are elements that constitute the engine cooling device according to the present invention.

When the engine 8 is operated, the water pump 31 is driven, and the cooling water is supplied from the radiator 27 to the suction passage 38.
→ Water pump 31 → Inlet passage 35 → Cooling water inlet 33 → Water jacket in cylinder block 14 → Water jacket in cylinder head 15 →
The coolant circulates in the order of the cooling water outlet 34 → the outlet passage 36 → the radiator 27, and the engine 8 is cooled by the cooling water heat exchanged by the radiator 27.

In this engine cooling device, the cooling water outlet 34 is located at the uppermost part of the entire cooling water path on the engine 8 side, so that air (bubbles) contained in the cooling water path collects in the cooling water outlet 34, and from there. Air release hose
It escapes to the upper part of the radiator 27 through 41 and is discharged from the cooling water replenishing cap 39 to the outside. Then, the cooling water is replenished from the cooling water reservoir tank 32 accordingly. The air bleeding hose 41 once extends upward from the cooling water outlet 34 and is connected to the upper part of the radiator 27 through a position higher than the outlet passage 36, so that the air bleeding is reliably performed.

As described above, since the air bleeding hose 41 ensures air bleeding, it is not necessary to consider the air bleeding property in the piping layout of the outlet passage 36, and the outlet passage 36 can be freely laid. 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 below the frame pipe 2b, a portion where there is a relatively large space is provided. The outlet passage 36 is provided to prevent the outlet passage 36 from protruding 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 protrusion of the outlet passage 36.

On the other hand, the air bleeding hose 41 is much thinner than the outlet passage 36, and the air bleeding hose 41 is connected to the side (here, the left side) of the cylinder head 15 opposite to the cam chain housing 17 and the left side of the vehicle body frame 2. With the frame pipe 2b. The distance between the left side of the cylinder head 15 and the left frame pipe 2b is
Since there is no cam chain housing 17, it is wider than the right side. Therefore, by disposing the air release hose 41 on the side opposite to the cam chain housing 17, the air release hose 41 is provided.
Cylinder head 15 and frame pipe 2b
It is not necessary to particularly widen the interval between them, and in this regard, it is also possible to effectively suppress an increase in the size of the vehicle body, an increase in the width of the cowling 12, and the like.

Further, in this engine cooling device, since the cooling water replenishing 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 like the motorcycle 1, The cooling water replenishing cap 39 can be easily attached and detached without removing the tank 9, and the workability at the time of refilling the cooling water is good.

In this embodiment, the engine 8 is a parallel four-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]

As described above, the engine cooling device for a motorcycle according to the present invention provides an air bleeding hose between the radiator and the cooling water outlet extending from the outlet passage. Since the air vent hose was once 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, a cooling water replenishing cap was also provided at the upper part of the radiator to serve as an air vent. The layout of the passages is liberalized and the vent passage protrudes in the vehicle width direction to prevent the vehicle body from becoming large and the cowling width from expanding. Since the refill cap is provided at the top of the radiator, It is possible to improve the work of.

Further, in the engine cooling device for a motorcycle according to the present invention, when the cam chain housing of the engine is provided on one side of the engine, the air release hose is connected to the cam chain housing of the cylinder head. Since it is arranged between the opposite side and the frame pipe of the body frame, it is not necessary to particularly widen the interval between the cylinder head and the frame pipe in order to arrange the air release hose. Can be prevented from being extended.

[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 has been applied.

FIG. 2 is a left side view around an engine.

FIG. 3 is a front view around an 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 entire configuration of the engine cooling device.

FIG. 6 is a right side view near the radiator.

FIG. 7 is a schematic left side view showing the entire configuration of an engine cooling device according to a conventional technique.

[Explanation of symbols]

 Reference Signs List 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 Passageway 39 Cooling water refill cap 41 Air release hose

Claims (2)

[Claims] 1. A water-cooled engine having a cylinder block and a cylinder head inclined forward on an upper surface of a crankcase is mounted on a front portion of a body frame, a radiator is installed in front of the engine, and the cylinder head is mounted on the engine. In a motorcycle engine cooling device in which an outlet passage extending from a cooling water outlet provided on a rear surface is connected to the radiator, a passage separate from the outlet passage 36 is provided between the cooling water outlet 34 and the radiator 27. The air bleeding hose 41 is connected, and the air bleeding hose 41 is temporarily extended upward from the cooling water outlet 34, and then connected to the upper part of the radiator 27 through a position higher than the outlet passage 36, and the upper part of the radiator 27 is also cooled for air release. Automatic refueling with water refill cap 39 Car of the engine cooling system. 2. When the cam chain housing 17 is provided on one side of the engine 8, the air bleeding hose 41 is connected to the side of the cylinder head 15 opposite to the cam chain housing 17 and to the vehicle body frame 2. The engine cooling device for a motorcycle according to claim 1, wherein the engine cooling device is arranged to pass between the frame pipe (2b) and the frame pipe (2b).