JPH0216323A - Water cooled engine for motorcycle - Google Patents

Abstract

PURPOSE:To heighten an equipment work quality, by forming part of the flow route of engine cooling water sent out of a water pump, integrally with a crank case cover, and at the same time, opening the outlet of a cooling water passage at the surface of exposure toward the outer direction of the crank case cover. CONSTITUTION:An oil pump 8 is fitted at the front end side portion of a crank case cover 6 covering the both side surfaces of a crank case 4 provided with a cylinder 5 extending upward to a front end upper surface, and at the same time, a water pump 12 is fitted at the location of the lower side portion 13 of an oil pump cover 10. The housing cover 16 of this pump 12 is fitted so as to blockade an opening 14 formed at the crank case cover 6. Also, a cooling water passage 29 which is connected to a pump chamber 18 and extends in a direction along the side surface of the cover 6, is formed integrally with the crank case cover 6, and the outlet 29a of this passage 29 is opened at the surface of exposure toward the outer direction of the cover 6, and a cooling water pipe 31 which is connected to the cylinder 5, is connected to this outlet 29a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water-cooled engine for a motorcycle, and particularly to the structure of a cooling water passage that guides cooling water sent from a water pump to a cylinder side.

[Prior Art] Modern motorcycles tend to have water-cooled engines in order to maintain stable output while driving.

By the way, when the engine is water-cooled, it is necessary to connect the engine and the radiator with a cooling water passage, and forcibly circulate the engine cooling water in the cooling water passage with a water pump. Since this water pump is driven by the shaft output of the crankshaft, conventionally, for example,
As seen in Jitsukō No. 54-26447,
The water pump is built into the side of the crankcase near the crankshaft. A cooling water pipe from the radiator and a cooling water pipe toward the cylinder are connected to this water pump, and this cooling water pipe is routed around the cylinder and crankcase of the engine.

[Problems to be Solved by the Invention] However, with this configuration, the long cooling water pipe passes through the side of the engine cylinder and crankcase, so the existence of this cooling water pipe creates a complicated and complicated structure around the engine. .

For this reason, in a motorcycle where the engine is exposed to the outside, the appearance is very unsatisfactory.

Moreover, if many cooling water pipes are installed around the engine, the cooling water pipes become a nuisance when performing maintenance work on the engine, resulting in a problem that the work requires a great deal of time and effort.

Therefore, it is an object of the present invention to not only maintain a good appearance, but also to prevent the cooling water pipes from interfering with maintenance work, and to improve the connection work between the cooling water pipes and the cooling water passages. An object of the present invention is to provide a water-cooled engine for a motorcycle in which the cross-sectional area of the cooling water passage can be freely set according to the position and shape of the auxiliary equipment on the crankcase side.

[Means for Solving the Problems] Therefore, in the present invention, the rotating shaft of the water pump is provided to pass through the crankcase cover that covers the side surface of the crankcase, and the rotating shaft is provided on the outside of the crankcase cover through which the rotating shaft passes. A cover is provided, a pump chamber is formed between the cover and the crankcase cover, and an impeller is provided at the tip of the rotating shaft facing the pump chamber, while the crankcase cover is connected to the pump chamber and includes: A cooling water passage extending in the direction along the side surface of the crankcase cover is integrally formed, the outlet of this cooling water passage is opened on the outwardly exposed surface of the crankcase cover, and a cooling water pipe connected to the cylinder is connected to this outlet. It is characterized by being connected.

According to this feature, a part of the flow path of the engine cooling water sent out from the water pump is formed integrally with the crankcase cover, so there is no place for the engine cooling water to flow around the crankcase. There is no need to run any pipes, which makes the engine area more organized. Also, if the pipes are omitted, the area around the crankcase is wide (open), so when performing engine maintenance work, the pipes will not get in the way.

Furthermore, since the outlet of the cooling water passage is opened in the outwardly exposed surface of the crankcase cover, this outlet does not enter a deep position in the engine. Therefore, when connecting a cooling water pipe to the outlet of the cooling water passage, the position of the outlet can be easily recognized as G1, and the workability of attaching and detaching the cooling water pipe is improved.

Further, since the cooling water passage is formed in the direction along the side surface of the crankcase cover, the cooling water passage does not straddle the pedestal part with the crankcase, and no special seal is required. At the same time, if the cooling water passage is formed integrally with the crankcase cover, the cross-sectional shape of the cooling water passage can be changed as appropriate depending on the position and shape of the auxiliary equipment on the crankcase side. It is possible to secure a cross-sectional area and prevent interference with the above-mentioned auxiliary machinery.

[Example] The present invention will now be described based on an example shown in the drawings.

Reference numeral 1 in FIG. 2 is a frame that constitutes the body of a motorcycle, and this frame 1 is provided with a pair of left and right down tubes 2. The engine 3 is mounted on these down tubes 21. The engine 3 of this embodiment is a water-cooled two-stroke single-cylinder engine, and is provided with a cylinder 5 extending in the L direction on the upper surface of the front end of the crankcase 4. Both sides of the crankcase 4 are covered with a crankcase cover 6 (only one is shown), and the front end side of one crankcase cover 6 has a cylinder 5, a crank chamber (not shown), and an intake passage for a carburetor 7. An oil pump 8 is attached to pump lubricating oil.

A clutch 9 is disposed at the rear end of one side of the crankcase 4, which is located behind the oil pump 8. The sides of the oil pump 8 and the clutch 9 are covered by an oil pump cover 10 and a clutch housing 11, which are formed into nail tubes on the sides of the crankcase cover 6. It protrudes laterally beyond the side surface of the case cover 6.

Further, a water pump 12 is attached to one crankcase cover 6. The water pump 12 has an oil pump cover 10 and a clutch housing 11 on top.
The water pump 12 is located in a lower portion 13 sandwiched between the water pumps 12 and 12, the details of which are shown in FIG.

That is, the lower part I3 of the crankcase cover 6 has an opening (4) that opens toward the side of the motorcycle body.
is formed. A housing cover 16 is attached to the periphery of the opening 14 via a gasket 15, and the housing cover 16 closes the opening 14 in a fluid-tight manner. A partition wall 17 is integrally formed on the inside of the crank case cover 6 and is interposed between the crank r-seat 4 and the opening 14. A pump chamber 18 is formed which is separated from the crankcase 4 side.

A rotating shaft 20 passes through the partition wall 17 of the pump chamber 18 via an oil seal 19. One end of the rotating shaft 20 faces the pump chamber 18, and an impeller 21 is attached to one end of the rotating shaft 20. In addition, the rotating shaft 20
The other end is led out to the crankcase 4 side, and a drive gear 22 for rotationally driving the rotating shaft 20 is attached to the outer periphery of this other end.

A drain hole 23 for draining engine cooling water in the pump chamber 18 is formed through the lower part of the housing cover 16 . A drain bolt 24 is inserted through the drain hole 23, and the insertion end of the drain bolt 24 is screwed into a screw hole 25 of the crankcase cover 6.

Therefore, this drain bolt 24 also has the function of fixing the housing cover 16 to the crankcase cover 6.

Further, the housing cover 16 is provided with a cooling water port 26 connected to the pump chamber 18 . This cooling water population 2
The opening end of the cooling water inlet 26 is connected to the first cooling water pipe 2 at the lower part of the radiator 27 attached to the rear side of the down tube 2.
8.

By the way, a cooling water passage 29 is integrally formed in the upper crankcase cover 6. The cooling water passage 29 extends vertically along the side surface 6a of the crankcase cover 6, and in the case of this embodiment, the cooling water passage 29 extends along the side surface 6a of the crankcase cover 6.
And clutch housing! It passes between 1 and 1. The lower end of the cooling water passage 29 is connected to the upper part of the pump chamber 18, and the outlet 2 at the upper end of the cooling water passage 29 is connected to the upper part of the pump chamber 18.
9a is opened on the upper surface exposed to the outside of the crankcase cover 6, and the cross-sectional shape of the cooling water passage 29 is changed as appropriate between the pump chamber 18 and the outlet 29a.

One end of a second cooling water pipe 31 is fluid-tightly connected to the outlet 29a of the cooling water passage 29 via an O-ring 30. The other end of the second cooling water pipe 31 is connected to the side surface of the cylinder 5 and continues to the water jacket inside the cylinder 5.

Furthermore, a cooling water outlet 33 at the top of the cylinder head 32
One end of a third cooling water pipe 34 is connected to the radiator 27, and the other end of this third cooling water pipe 34 is connected to the radiator 27.
connected to the top of the

Therefore, the engine cooling water radiated by the radiator 27 is sucked into the pump chamber 18 of the water pump 12 through the first cooling water pipe 28 by the rotation of the impeller 21, and the pressure is gradually increased in the pump chamber 18. The coolant is then sent out into the cooling water passage 29.

This engine cooling water is force-fed from the cooling water passage 29 through the second cooling water pipe 31 to the water jacket of the cylinder 5, and cools the cylinder 5 and the cylinder head 32 as it flows through the water jacket. This engine cooling water is then returned to the radiator 27 via the third cooling water pipe 34, where heat is radiated, and then guided to the cylinder 5 via the water pump 12 again.

According to this configuration, the water pump 12 is provided on the crankcase cover 6, and the cooling water passage 29 connected to the pump chamber 18 is integrally formed in the crankcase cover 6. There is no need to run pipes to route cooling water. Therefore, the area from the crankcase 4 to the cylinder is neatly arranged, and the appearance of the engine 3 is improved accordingly. Moreover, if the pipes are omitted from around the crankcase 4, the area around the crankcase 4 is left wide open, so when performing maintenance work on the engine 3, the pipes will not get in the way. .

Furthermore, since the outlet 29a of the cooling water passage 29 is opened in the outwardly exposed surface of the crankcase cover 6, the outlet 29a does not enter deep inside the engine 3.

Therefore, when connecting the second cooling water pipe 31 to the outlet 29a of the cooling water passage 29, the position of the outlet 2921 can be easily confirmed, and the workability of attaching and detaching the cooling water pipe 31 is improved. .

Further, since the cooling water passage 29 is formed along the side surface of the crankcase cover 29, it does not straddle the part between the crankcase 4 and a special seal.

At the same time, if the cooling water passage 29 is formed integrally with the crankcase cover 6, the cross-sectional shape of the cooling water passage 29 can be changed as appropriate depending on the position and shape of the auxiliary equipment on the crankcase 4 side. Therefore, there is an advantage in that it is possible to secure the cross-sectional area of the cooling water passage 29 while preventing interference with the above-mentioned Supplementary II.

Note that the engine according to the present invention is not limited to a two-stroke engine, but may be a four-stroke engine, and the number of cylinders is not limited to a single cylinder, but may be a multi-cylinder engine.

Further, in the above embodiment, the oil pump is provided in front of the clutch, but it may also be provided in the rear of the clutch.

[Effects of the Invention] According to the present invention described in detail above, there is no need to route the pipes for passing the engine cooling water around the crankcase, so the engine cooling water is gathered all around the crankcase, and the engine cooling water is reduced accordingly. Improves appearance. Moreover, since the area around the crankcase is wide open, pipes do not get in the way when servicing the engine.

Furthermore, since the outlet of the cooling water passage can be seen from the outside of the crankcase cover, the position of the outlet can be easily confirmed when connecting the cooling water pipe to this outlet.
Improves the workability of attaching and detaching cooling water pipes.

In addition, the cooling water passage does not need to straddle the base of the crankcase cover and the crankcase, eliminating the need for special seals, and the cross-sectional shape of the cooling water passage can be adjusted to match the position and shape of the auxiliary equipment on the crankcase side. The cross-sectional area of this cooling water passage can be ensured and interference with the above-mentioned auxiliary equipment can be prevented.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view of the water pump and its surroundings, and FIG. 2 is a side view of the entire engine. 4...Crankcase, 5...Ninda, 6...
Crankcase cover 12...Water pump, 1
G... Cover (bousing cover), 18... Pump chamber, 20... Rotating shaft, 21... Impeller, 29...
...Cooling water passage, 29a...Outlet, 31...Cooling water pipe. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] On the crankcase cover that covers the side of the crankcase,
A rotating shaft of the water pump is provided through the crankcase cover, a cover is provided on the outside of the crankcase cover through which the rotating shaft passes through, a pump chamber is formed between this cover and the crankcase cover, and a rotating shaft facing the pump chamber is provided. An impeller is provided at the tip of the shaft, and the crankcase cover is integrally formed with a cooling water passage that is connected to the pump chamber and extends in a direction along the side surface of the crankcase cover, and the outlet of this cooling water passage is connected to the crankcase. A water-cooled engine for a motorcycle, characterized in that an opening is formed on an outwardly exposed surface of a case cover, and a cooling water pipe connected to a cylinder is connected to this outlet.