JPH03258917A - Engine cooling device - Google Patents

Abstract

PURPOSE:To facilitate air bleeding operation and to prevent residual of air in a cooling fluid passage of an engine by providing a filler hole of a cooling device on the engine side. CONSTITUTION:A cooling water passage 66 through which cooling water flows is formed on at least a cylinder head 55 of an engine 16, the cooling water passage 66 is communicated with a radiator 70 for circulation of cooling water between the cooling water passage 66 and the radiator 70. Also, a filler hole 87 opened and closed by a cap 88 is provided at the highest position of a piping 86 of the cooling water arranged from the cooling water passage 66 to the radiator 70. Here, the filler hole 87 is provided on the side of the engine 16. By this, the cooling water can be filled directly into the cooling water passage 66 of the engine 16, and residual of air at the part which requires cooling the most in all the flow path of the cooling water is prevented. Thus, efficiency of cooling is improved, and as no attention should be paid to air bleeding opera tion, the air bleeding operation can be carried out easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cooling device for, for example, a motorcycle engine, and particularly to a structure around a cooling water inlet.

[Prior Art] A scooter-type motorcycle includes a swing-type engine unit that integrates an engine and a V-belt automatic transmission. Conventionally, forced air-cooled engines have been used in this type of engine unit, but recently there has been a trend toward water-cooled engines in order to improve quietness and obtain stable performance.

When the engine is water-cooled, the water jacket of the engine is connected to the radiator via piping.
Cooling water is circulated between the radiator and the radiator. Since the radiator is usually installed at a higher position than the engine, a cooling water inlet that is opened and closed by a cap is provided at the top of the radiator.

[Problems to be Solved by the Invention] However, according to this conventional configuration, the cooling water inlet is installed in the radiator away from the engine, so
Depending on the layout of the piping connecting the radiator and the engine, it may be difficult for the air carried into the water jacket to bleed out when, for example, air is to be removed when exchanging cooling water.

For this reason, it takes time to bleed air, and there remains a possibility that air may accumulate in the water jacket of the parts of the engine that require the most cooling, such as the cylinder head.

The present invention was made based on these circumstances, and
An object of the present invention is to provide an engine cooling device that facilitates air removal work, makes it difficult for air to remain in a coolant passage of an engine, and improves cooling efficiency.

[Means for Solving the Problems] Therefore, in the present invention, a cooling water passage through which cooling water flows is formed at least in the cylinder head of the engine, and this cooling water passage is communicated with the radiator, so that the cooling water passage and the cooling water passage are connected to each other. In an engine cooling system, the cooling water is circulated between the cooling water and the radiator, and an injection port is provided at the highest position of the cooling water flow path from the cooling water passage toward the radiator, and the injection port is opened and closed by a cap. is provided on the engine side.

[Operations] According to this configuration, by providing the injection port in the engine, the cooling water can be directly injected into the cooling water passage of the engine, and the cooling water can be directly injected into the part of the cooling water flow path that requires the most cooling. Air becomes difficult to accumulate.

Therefore, cooling efficiency is improved, and there is no need to pay more attention to air bleeding than in the past, making the air bleeding easier.

[Embodiment 1] An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a scooter-type motorcycle.

The frame designated by reference numeral 1 in FIG. 7 is provided with a steering head vibe 2 at its front end. A front wheel 4 is supported by the steering head vibe 2 via a front fork 3.

Moreover, one down tube 5 extending downward is connected to the steering head vibe 2. The lower end portion of the down tube 5 extends rearward substantially horizontally, and a pair of left and right main vibrators are connected to the rear portion of this horizontal portion 5a. The main vibro is raised immediately after the horizontal portion 5a, and the upper end of this raised portion 7 forms an extension portion 8 extending rearward. A fuel tank 9 and a storage box 10 for storing a helmet, for example, are installed on the top surface of this extension part 8, and a seat 11 is installed on the top surface of these fuel tank 9 and storage box 10. It is located.

A swing type engine unit 15 is arranged below the extension part 8 of the main vibro.

As shown in FIG. 6, this engine unit 15 includes a four-stroke single-cylinder engine 16 and a transmission case 1 extending rearward from the left side of a crankcase 17 of this engine 16.
8, and a support protrusion 19 protruding from the upper surface of the crankcase 17 is swingably supported by the extension part 8 via an engine bracket 20.

The crankcase 17 has a left case 17a and a right case 17b.
It is divided into. Both cases 17a.

A crank chamber 21 is formed between the crankshafts 17b, and a crankshaft 22 is accommodated in the crank chamber 21. A left case 17a of the crankcase 17 and a left side surface of a transmission case 18 connected thereto are covered by a case cover 23. Both cases 17a.

A transmission chamber 24 is formed between the transmission chamber 18 and the case cover 23, and one end of the crankshaft 22 is introduced into the front end of the transmission chamber 24.

A driven shaft 25 parallel to the crankshaft 22 is supported at the rear of the transmission chamber 24, and a V-belt automatic transmission 26 that interlocks the driven shaft 25 and the crankshaft 22 is housed within the transmission chamber 24. ing.

■The belt automatic transmission 2B has a structure similar to that of a conventionally known one, and as shown in FIG.
A secondary sheave 29 is attached to the outer circumference of the sheave 27 via a centrifugal clutch 28, and a V-belt 30 is wound between these sheaves 27.29. By changing the diameter of the winding 30, the gear ratio between the crankshaft 22 and the driven shaft 25 is automatically changed.

The driven shaft 25 is interlocked with an axle 32 of a rear wheel 31 via a gear transmission (not shown), and this axle 32 is supported by the rear end of the transmission case 18.

On the other hand, the engine 16 has a cylinder block 35 extending substantially horizontally forward from the front end of the crankcase 7.
It is equipped with The cylinder block 35 is composed of a bore portion 37 forming a cylinder 36 and cooling fins 38 protruding from the outer peripheral surface of the bore portion 37.
The inner piston 39 is connected to the crankshaft 22 via a connecting rod 40.

The cylinder block 35 is surrounded by an air shroud 41. At the right end of air shroud 4I,
A fan cover 42 is provided continuously. This fan cover 42 is attached to the right case 17 of the crank case 17.
It also serves as a crankcase cover that continuously covers b.
An axial fan 43 is arranged inside the fan cover 42. The fan 43 is located on the right side of the cylinder block 35, and is provided facing a continuous portion of the air shroud 4L and the fan cover 42.

The rotating shaft 44 of the fan 43 is connected to the right case 17.
The support stay 45 is pivotally supported via a bearing 47 on a boss portion 4G of a support stay 45 extending from b, and a driven pulley 48 is mounted on this rotating shaft 44.

The fan cover 42 also integrally covers a flywheel magnet 49 fixed to the right end of the crankshaft 22. A drive pulley 51 is attached to the rotor shaft 5o of the flywheel magneto 49, and a belt 52 is wound between the drive pulley 51 and the driven pulley 48. Therefore, the fan 43 is driven to increase its speed by power transmission from the crankshaft 22, and when the fan 43 is driven to rotate, outside air is drawn in from the suction port 53 on the right side of the air shroud 41. The air is forcibly blown around the cylinder block 35.

A downwardly opening discharge port 54 is provided at the left end of the air shroud 41, and outside air blown around the cylinder block 35 is discharged outward through the discharge port 54.

Further, a cylinder head 55 is connected to the front end of the cylinder block 35. As shown in FIG. 3, the cylinder head 55 is inserted between the rising portions 7 of the main vibro, and the cylinder head 55 is formed with an intake port 57 and an exhaust port 58 that open into the combustion chamber 56. . The intake port 57 and the exhaust port 58 are arranged vertically with respect to the bore center X1 of the cylinder 3B, and the intake port 57 and the exhaust port 58 are opened and closed by an intake valve and an exhaust valve (not shown).

The intake port 57 extends above the cylinder head 55 and is opened rearward, and a carburetor 60 is connected to this open end via a joint 59.

The carburetor 60 is connected to an air cleaner 69, which is arranged above the transmission case 18 and the case cover 23.

Furthermore, a valve operating chamber 61 is formed at the front end of the cylinder head 55 . A camshaft 62 for opening and closing the intake valve and the exhaust valve is accommodated in the valve operating chamber 61. camshaft 6
One end of 2 is introduced into the chain passage 63 on the left side of the cylinder block 35 and cylinder head 55,
A timing sprocket 6 is attached to the introduction end of this camshaft 62.
4 is installed. The front end of the chain passage 63 is continuous into the crankcase 17, and a timing chain 65 is wound between the crankshaft 22 in the crankcase 17 and the timing sprocket 64.

By the way, the cylinder head 55 of the engine 1G of this embodiment is of a water-cooled type;
A cooling water passage 66 surrounding the combustion chamber 56, the intake port 57, and the exhaust port 58 is formed inside the engine. A cooling water passage 67 connected to the cooling water passage 6B is formed on the lower surface of the cylinder head 55, and a cooling water passage 67 is formed on the right side of the upper part of the cylinder head 55.
A cooling water outlet 68 connected to the cooling water outlet 6 is formed.

Furthermore, since the cylinder head 55 is water-cooled, a radiator 7o is installed at the suction port 53 of the fan cover 42, as shown in FIG.

The radiator 7o is equipped with a vertical water flow type radiator core 71, and an upper tank 72 and a lower tank 73 are provided at the upper and lower ends of the radiator core 7I, respectively. A radiator bracket 74 is welded to the front end and rear end of the radiator core 71.

The above-mentioned crank case 17 is attached to the radiator bracket 74.
A support stay 75 is formed toward the right side of the right case 17b and the cylinder head 55, and this support stay 7
As shown in FIG. 4, a vibration isolating rubber 76 is provided at the tip of 5. As shown in FIG. Further, on the right side of the right case 17b and the cylinder head 55, a plurality of column-shaped mounting seats 77 are protruded, and the vibration isolating rubber 76 is mounted on the tip surface of the seat 77. are placed one on top of the other, and are tightened and fixed by screws 78.

Therefore, the radiator 70 is vibration-proofly supported with respect to the engine I6 via the vibration-proof rubber 76.

The lower tank 73 of the radiator 70 is connected to the cooling water port 67 of the cooling water passage 66 via a pipe 80. Further, a water supply pipe 81 extending upward is connected to the cooling water outlet 68 of the cooling water passage 66, as shown in FIGS. 1 and 2. A connecting portion 82 bent at right angles is formed at the lower end of the water supply pipe 81, and this connecting portion 82 is inserted liquid-tightly into the cooling water outlet 68 via a seal ring 83. A bracket 84 is welded to the outer peripheral surface of the water supply pipe 81. As shown in FIGS. 4 and 6, the lower end of this bracket 84 is inserted between the seat portion 77 and the vibration isolating rubber 76 for mounting the cylinder head 55. Water supply pipe 81 is connected to cylinder head 55
directly supported.

A connecting pipe section 85 branched from the water supply pipe 81 is provided at the upper part of the water supply pipe 81 . The connecting pipe portion 85 is the pipe 8
The cooling water passage 66 of the cylinder head 55 is connected to the upper tank 72 of the radiator 70 through the upper pipe 86, the water supply pipe 81, and the lower pipe 80.
A cooling water flow path is configured to connect the radiator 70 and the radiator 70 .

A large-diameter filler neck 87 that serves as a cooling water inlet is formed above the branching portion of the connecting pipe portion 85 in the water supply pipe 81 . The filler neck 87 is provided at the highest position in the cooling water flow path including the radiator 70 and the cooling water passage 86.
7 is removably attached to a pressure adjusting valve 88 which includes a built-in pressure regulating valve and a negative pressure valve (not shown).

An overflow vibe 89 is connected to the filler neck 87. As shown in FIG. 3, this overflow vibe 89 is connected to a reservoir tank 90.
This reservoir tank 90 is arranged immediately in front of the cylinder head 55.

Further, a cooling water pump 9 for circulating cooling water is provided in the middle of the lower piping 80 connecting the radiator 70 and the cooling water passage 66.
5 is provided. The cooling water pump 95 includes a pump body 96 attached to the left side of the cylinder head 55 and a pump cover 97 that covers the left side of the pump body 96. A pump chamber 98 is formed between the pump body 96 and the pump cover 97. A suction port 99 and a discharge port 100 are formed in the pump cover 97 and are connected to the pump chamber 98.
9 and the discharge port 100 are connected to the lower pipe 8D.

An impeller 101 is housed within the pump chamber 98.

The drive shaft 102 of this impeller 101 is connected to the pump body 96
One end of the drive shaft 102 is led out into the chain passage 63 and coaxially connected to the camshaft 62. Therefore, the cooling water pump 95 is driven by the camshaft 62.

In the case of this embodiment, a blow-by gas separation chamber 10 connected to the chain passage 63 is provided on the outer periphery of the boss portion 96a.
5 is formed. A breather port 10B is formed in this separation chamber 105, and this breather port 106 is connected to the air cleaner 69 via a breather vibe 107.

In such a configuration, while the engine 16 is operating, the fan 43 is constantly driven to rotate, and outside air is sucked in through the suction port 53 of the fan cover 42, so that the outside air passes through the radiator 70 installed in the suction port 53. .

Furthermore, while the engine 16 is operating, the coolant pump 95 is driven by the camshaft 62, so that coolant is circulated between the coolant passage 66 of the engine 16 and the radiator 70.

That is, the cooling water that has become high in temperature while flowing through the cooling water passage 66 of the cylinder head 55 flows from the cooling water outlet 6B to the upper tank 72 of the radiator 70 through the water supply pipe 81, the connecting pipe #85, and the upper pipe 86, and from there. It is guided to the radiator core 71. In the process of passing through the radiator core 71, this cooling water passes through the suction port 5.
The cooling water that has been cooled by exchanging heat with the outside air drawn into the cooling water tank 3 is guided from the lower tank 73 to the cooling water passage 66 again through the lower piping 80.

Incidentally, in the above configuration, a water supply pipe 81 extending upward from the cooling water outlet 68 is connected to the cylinder head 55, and a filler neck 87 serving as an inlet is provided at the upper end of this water supply pipe 81. When changing the water,
New cooling water is directly supplied to the cooling water passage 6 of the cylinder head 55.
6 can be injected directly.

Therefore, air is less likely to accumulate in the part of the cooling water flow path that requires the most cooling, that is, the cooling water passage 66 of the cylinder head 55, and the cooling efficiency is improved.

Furthermore, since air is less likely to accumulate in the cooling water passage 6B, there is no need to pay more attention to the air removal operation than in the past, and the air removal operation can be performed more easily.

Furthermore, in this embodiment, since the radiator 7o is fixed to the right side of the cylinder block 35, the lengths of the upper and lower pipes 80, 88 that connect the radiator 70, the cylinder head 55, and the cooling water pump 95 can be kept short. The cooling water flow path outside the engine 16 can be short.

Therefore, not only can the piping go and ge be routed easily, but also the air mixed in the cooling water during the air bleeding operation can be easily removed, and the working time can be shortened.

Furthermore, as the cooling water flow path is shortened, the flow resistance of the cooling water is also reduced, so the cooling water pump 95 can also be used with a small capacity. Therefore, there is an advantage that the load on the engine 16 that drives the cooling water bomb 95 is reduced accordingly, and the horsepower loss of the engine 16 can be minimized.

In the above embodiment, the cylinder block of the engine is forced air-cooled, and only the cylinder head is water-cooled, but the present invention is not limited to this, and both the cylinder head and cylinder block may be water-cooled.

Further, the radiator is not limited to being fixed to the engine side, but may be installed, for example, in front of the front fork with good ventilation, and the engine is not limited to a unit swing type with an integrated V-belt automatic transmission.

Further, the engine cooling device according to the present invention is not limited to use in motorcycles, but can be similarly applied to other vehicles such as four-wheeled vehicles and small snowmobiles.

[Effects of the Invention] According to the present invention described in detail above, since the cooling water can be directly injected into the cooling water passage of the engine, air is less likely to accumulate in the portion of the cooling water flow path that requires the most cooling. Therefore, the efficiency of cooling is improved, and there is no need to pay more attention to the air bleeding operation than in the past, and the air bleeding operation can be performed more easily.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention. Figure 1 is a front view of the engine with the cylinder head partially cut away, Figure 2 is a side view of the cylinder head, and Figure N3 is the positional relationship between the frame and the engine unit. FIG. 4 is a sectional view of the cylinder head, FIG. 5 is a rear view of the cylinder head, FIG. 6 is a sectional view of the entire engine unit, and FIG. 7 is a side view of the scooter type motorcycle. 16...Engine, 55...Cylinder head, 66
...Cooling water passage, 70...Radiator, 87...
Inlet (filler neck), 88...cap (pressure cap).

Claims (1)

[Claims] A cooling water passage through which cooling water flows is formed at least in the cylinder head of the engine, and this cooling water passage is communicated with a radiator to circulate the cooling water between the cooling water passage and the radiator. An engine cooling device comprising an injection port opened and closed by a cap at the highest position of a cooling water flow path from the cooling water to the radiator, characterized in that the injection port is provided on the engine side. .