JP3392851B2 - Coolant passage structure for V-type small liquid-cooled engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle, a compact all-terrain vehicle (compact terrain vehicle, hereinafter also simply referred to as ATV), a snowmobile, a compact leisure vehicle, and a compact planing boat. The present invention relates to a cooling liquid passage structure for a V-type small liquid-cooled engine mounted on a vehicle or the like.

[0002]

2. Description of the Related Art A motorcycle, a small ATV (small terrain vehicle), a snowmobile, a small leisure vehicle, a small planing boat, or the like has a small liquid-cooled engine (hereinafter Some are equipped with a water-cooled engine). In the case of these water-cooled engines, a low-temperature cooling water (cooling liquid) cooled by a radiator is generally formed around a combustion chamber of the engine from a water pump rotated by a drive shaft of the engine. Supplied to the jacket side. In the conventional case, in a small engine, such as a motorcycle engine, the water pump is arranged in the lower part of the engine as described in JP-A-3-117614, and from this water pump, a flexible rubber hose or the like is provided. In many cases, water is supplied to the water jacket side formed in the cylinder of the engine above.

However, in this case, in an engine such as a motorcycle, the rubber hose around the engine is visible from the outside. However, motorcycles, small rough terrain vehicles,
In the case of leisure vehicles, in addition to good performance, fashion is highly evaluated today,
If a rubber hose is placed around the engine, no matter how you design the appearance of the engine itself, the engine part as a whole will feel awkward. Also,
When a rubber hose is used, the circumference of the engine is complicated by the rubber hose, and the number of parts and the number of assembling steps are increased, which increases the manufacturing cost of the engine part.

The present invention has been made in view of the above circumstances, and it is a V-type liquid cooling system that is clean in appearance and contributes to a reduction in manufacturing cost by reducing the number of parts and the number of assembly steps. An object of the present invention is to provide a coolant passage structure for a rotary engine.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems by
This can be solved by the cooling liquid passage structure of the V-type liquid cooling engine having the following configuration. That, V type small liquid cooled engine according to the present invention, the water pump, the water jacket side, which is formed on the cylinders arranged in a V-type, V-type small configured to cool leading the coolant A coolant passage structure for a liquid-cooled engine, wherein the water pump is located at a lower end of the engine.
To such, di annexed to the crankcase of the engine
Attach it to the generator cover or its vicinity, and make sure that it is built into the outer periphery of the generator cover.
A liquid flow passages are provided in the form, characterized by being configured to direct the coolant to the water jacket side, which is formed in each cylinder of the engine.

According to the cooling liquid passage structure of the V-type small liquid-cooled engine thus constructed, however, the cooling liquid is supplied from the water pump to the water jacket side of the cylinder through the liquid passage inside the cover. From being
It eliminates the need for conventional rubber hoses, makes it possible to achieve a design that is extremely sleek in appearance, and the area around the engine is not complicated.

Further, in the above invention, the above-mentioned cold
From the generator cover,
So that everything goes through these inside the crankcase
When configured, the design is extremely sleek in appearance.
This is the preferred configuration.

Further, in the above invention, the above
Part of the generator cover is
When the inner wall is formed, it is a practically preferable configuration.

Further, in the above invention, a water gallery communicating with the liquid passage and having a liquid passage hole for each cylinder and extending in parallel with the crankshaft at a portion sandwiched by the cylinders is provided, and a V type is provided. If the water gallery is formed in the crankcase while the cooling liquid is guided to each of the cylinders, the structure of the liquid passage hole can be simplified, and the V-shape can be achieved with little pressure loss. The cooling liquid can be supplied to the water jacket of each cylinder arranged in the above.

Further, in the above invention, the rotating shaft of the water pump is coaxial with the rotating shaft of the oil pump.
The sprockets for driving these rotating shafts
At the position between the water pump and the oil pump
When installed, the engine has a compact and rational structure.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION V according to an embodiment of the present invention will be described below.
The liquid coolant passage structure of the small-sized liquid-cooled engine will be described in detail with reference to the drawings together with the configuration of an all-terrain vehicle to be mounted. FIG. 1 is an overall side view of an all-terrain vehicle equipped with an engine having a cooling liquid passage structure of a V-type small liquid-cooled engine according to this embodiment, and FIG. 2 is a flow of cooling liquid from a water pump to a cylinder side. A right side sectional view of the engine portion showing the (cooling liquid passage) from a side view,
3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a water pump showing the configuration of the liquid passage of the generator cover in which the liquid passage shown in FIGS. 2 and 3 is shown by a broken line (hidden line). FIG. 3 is a side view with the cover and the impeller removed.

As shown in FIG. 1, a riding type four-wheel all-terrain vehicle A has steering bar-type handles Hn rotatably mounted on a vehicle body Fr, left and right front wheels Wf, and left and right rear wheels Wr. have. Further, in the riding type four-wheel all-terrain vehicle A, a front carrier Cf is arranged in front of the handle Hn, a cover T covering the upper part of the air cleaner is provided behind the handle Hn, and a cover T for riding is provided behind the cover T. Sheet Se
And the rear carrier Cr is disposed on the rear side of the sheet Se. Further, footboards Fb are respectively disposed on the left and right sides of the seat Se, diagonally below the front and at positions substantially equal to the height of the axles of the front wheels Wf and the rear wheels Wr. A V-type 2-cylinder OHC 4-cycle engine (hereinafter, simply referred to as V-type engine) E is disposed below the cover T so that the lower end thereof has a height substantially equal to the height of the footboard Fb. ing. V type engine E
The two cylinders are arranged at the front and rear so as to have an included angle in the front and rear direction. The V-type engine E includes a torque converter and a transmission gear unit (not shown), a front output shaft Pf or a rear output shaft Pr arranged substantially in the front-rear direction,
And the front wheels Wf or the rear wheels Wr are driven via a differential device (not shown).

In the riding type four-wheeled all-terrain vehicle A constructed as described above, the rider straddles the seat Se, places his / her foot on the footboard Fb, and holds the steering wheel Hn with both hands. Drive A.

By the way, the V-type engine is a water-cooled type (liquid-cooled type), and a water pump P is arranged at the lower end of the engine E as shown in FIG. As shown in FIG. 3 which is a cross-sectional view or FIG. 5 which is a partial cross-sectional view, this water pump P includes an impeller 1A rotatably disposed in a central portion, an intake port 1a and a discharge port 1b. And a pump chamber 1B that covers the impeller 1A. In this embodiment, the outer wall of the pump chamber 1B is formed by the cover P2 of the water pump P. When the impeller 1A is driven from the crankshaft 10 side, as shown in FIG. 2, the cooling liquid is sucked from the suction port 1a communicating with the radiator (not shown) arranged in front of the vehicle body. The cooling water is discharged from the discharge port 1b toward the water jacket 25 (25A, 25B) provided in the cylinder S of the engine E. The inner wall 1Ba and the discharge port 1b of the pump chamber 1B shown in FIG. 4 are formed by utilizing a part of the generator cover 20 attached to the side portion of the engine. In addition, the generator chamber 20 includes the pump chamber 1
A liquid passage (water passage) 20A having a circular cross section, which communicates with the B discharge port 1b, is integrally formed. That is, the liquid passage 20A is built in the outer peripheral portion of the generator cover 20 so as to form a part of the generator cover 20, and as shown in FIG.
It is formed from the outlet of the discharge port 1b of B to the vicinity of the lower end of the cylinder S of the engine. The liquid passage 20A communicates with a water gallery 22g formed integrally with the crankcase 22 near the lower end of the cylinder S. The water gallery 22g is illustrated in FIG. 3 so as to connect the cylinders S1 and S2 to a portion sandwiched between the cylinders S1 and S2 that are adjacent to each other in the front and rear (left and right in FIG. 2) arranged in a V shape. So that it extends substantially parallel to the crankshaft 10. Therefore, this water gallery 22
g is formed by bending approximately 90 degrees with respect to the liquid passage 20A. That is, in FIG.
It is formed so as to extend in the depth direction of the paper from the upper end of A. And in this water gallery 22g,
As schematically shown in FIG. 3, the water jacket 25A of the first cylinder S1 (see FIG. 2) facing the front of the vehicle body.
(See FIG. 2) Fluid passage hole 22a and second cylinder S2 located behind the first cylinder S1 (see FIG. 2)
It has a liquid passage hole 22b communicating with the water jacket 25B (see FIG. 2) (see FIG. 2). The liquid passage holes 22a and 22b are provided in the cylinder liquid passage 26 formed on the cylinders S1 and S2 side, as shown in FIG.
a, 26b, and consequently, as described above, communicates with each water jacket 25A, 25B. Therefore, the coolant passage of the V-type liquid-cooled engine according to this embodiment includes the generator cover 20 to the crankcase 22.
It is configured to pass through all of them inside. In FIG. 2 and FIG. 4, 28 is the liquid passage 2
A lid member for sealing the end portion of 0A, and this liquid passage 20A
This is for covering the opening portion required when die casting is performed integrally with the generator cover 20.

Further, in this embodiment, as shown in FIG. 3, the rotation shaft Pa of the water pump P is rotatably supported by the generator cover 20 and is extended inside the engine E. The extended portion serves as the rotating shaft of the oil pump 30 for lubricating the engine E.
That is, the water pump P and the oil pump 30 share the rotation axis Pa. A sprocket 26 is integrally provided on the rotary shaft Pa, and the sprocket 26 is connected to the sprocket 12 integrally provided on the crankshaft 10 by a chain 14. Therefore, when the crankshaft 10 rotates, the water pump P and the oil pump 30 operate.

In this embodiment, the liquid passage 20A is
Although it is formed integrally in the generator cover as described above, it may be formed integrally in another cover provided on the side of the crankcase depending on the arrangement of the generator cover. Further, the cover is not limited to one cover, and may be formed by using two or more covers.

In FIG. 2, C is a carburetor and A is a carburetor.
c is an air cleaner, Q is a cooling tube for supplying cool air to the belt converter, Ex is an exhaust pipe, and Of is an engine oil filter.

By the way, if the cooling liquid passage structure according to the present invention is adopted in an ATV or the like where the engine side surface is exposed from the side as in this embodiment, a hose or the like for the cooling liquid becomes unnecessary, so that the engine is eliminated. It is particularly effective because the part can be made to have a neat appearance. Even if the water pump is arranged in the lower part of the engine away from the cylinder as in this embodiment, if the cooling liquid passage is formed by using the cover such as the generator cover as described above, the cooling liquid passage can be easily formed. It can be manufactured at low cost.

[0019]

According to the cooling liquid passage structure of the V-type liquid cooling engine according to the present invention, the cooling liquid flows from the water pump to the cylinder side through the liquid passage built in the cover such as the generator cover. Since it is supplied, a rubber hose exposed to the outside as in the conventional case is not required, so that the appearance of the entire engine can be made a clean design.

Further, since the number of parts and the number of assembling steps can be reduced, the manufacturing cost of the V-type liquid-cooled engine can be reduced.

[Brief description of drawings]

FIG. 1 is an overall side view of an all-terrain vehicle equipped with an engine having a cooling liquid passage structure for a V-type small liquid-cooled engine according to this embodiment.

FIG. 2 is a right side cross-sectional view of an engine portion showing a side view of a flow of a cooling liquid (cooling liquid passage) from a water pump to a cylinder side.

FIG. 3 is a sectional view taken along the line III-III of FIG.

FIG. 4 is a side view showing a configuration of the liquid passage of the generator cover having the liquid passage shown in FIGS. 2 and 3 in a broken line, with the cover of the water pump and the impeller removed.

5 is a partial cross-sectional view taken along the line VV of FIG. 4 showing the configuration of the connection portion between the water pump and the cover of the liquid passage shown in FIG.

[Explanation of symbols]

E ... Engine S (S1, S2) ... Cylinder P: Water pump 20 ... Generator cover (cover) 20A ... fluid passage 22 ... Crank case 25 (25A, 25B) ... Water jacket

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Claims (5)

(57) [Claims] 1. A water pump arranged in a V-shape
To the water jacket side formed on each cylinder ,
A cooling liquid passage structure for a V-type small liquid-cooled engine configured to guide and cool a cooling liquid, wherein the water pump is located at a lower end portion of the engine.
As was attached to the crankcase of the engine generator
A shape that is attached to the generator cover or its vicinity and built into the outer periphery of the generator cover.
State in providing liquid flow passages, coolant passages structure of the V-type small liquid cooled engine, characterized by being configured to direct coolant to the water jacket side, which is formed in each cylinder of the engine. 2. The cooling liquid passage of the cooling liquid passage structure comprises :
This is everything from the generator cover to the crankcase
2. The cooling liquid passage structure for a V-type small liquid-cooled engine according to claim 1, wherein the cooling liquid passage structure is configured to pass through the inside of these components . 3. A portion of the generator cover is the
The cooling liquid passage structure for a V-type small liquid-cooled engine according to claim 1 or 2, wherein an inner wall of the water pump is formed . 4. A water gallery communicating with the liquid passage and having a liquid passage hole for each cylinder and extending parallel to the crankshaft at a portion sandwiched by the cylinders is provided to form each V-shape. 3. The V according to claim 2, wherein the water gallery is formed in the crankcase while the cooling liquid is introduced into the cylinder.
Type liquid cooling engine coolant passage structure. 5. The rotating shaft of the water pump is coaxial with the rotating shaft of the oil pump, and these rotating shafts are driven.
The sprocket for this is the water pump
The cooling liquid passage structure for a V-type small liquid-cooled engine according to any one of claims 1 to 4, wherein the cooling liquid passage structure is arranged between the oil pumps .