JP2853002B2 - Engine water cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water cooling device for an engine, and more particularly, to a device for shortening the entire length of an engine.

[0002]

2. Description of the Related Art FIG.
There are the following. This has the following basic structure as in the present invention. That is, the cylinder block 1
01, a gear case 103 is attached to the front side surface 102, a crankshaft end 104 is projected forward from the gear case 103, and the crank pulley 10 is attached to the crankshaft end 104.
5, and a pump input pulley 108 is fixed to a pump shaft 107 inserted into the water pump chamber 106.
A cooling fan 109 is fixed to a pump shaft 107 in front of the pump input pulley 108, and a timing belt 110 is wound around the crank pulley 105 and the pump input pulley 108 in series to form a belt transmission mechanism 111. .

In a motor having such a basic structure, a pump shaft 1 is driven from a crankshaft via a belt transmission mechanism 111.
07, the cooling water is forcibly circulated, and the cooling fan 109 is rotated.

In the prior art, since the water pump chamber 106 is provided on the front side wall 117 of the gear case 103, the water pump chamber 106 is provided on the front side 1 of the cylinder block 101.
The projecting dimension 118 of the cooling fan 109 from 02 is relatively long.

[0005]

In the above prior art, the projecting dimension 118 of the cooling fan 109 from the front side surface 102 of the cylinder block 101 is relatively long, which causes the overall length of the engine to be long.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine cooling device capable of shortening the entire length of the engine.

[0007]

According to the present invention, as shown in FIG. 1A, a gear case 3 is attached to a front side surface 2 of a cylinder block 1 and a crankshaft end 4 is provided forward from the gear case 3. The crank pulley 5 is externally fitted and fixed to the crankshaft end 4, and as shown in FIG.
A pump input pulley 8 is fixed to a pump shaft 7 inserted into the water pump chamber 6, and a cooling fan 9 is fixed to the pump shaft 7 in front of the pump input pulley 8, as illustrated in FIG. Crank pulley 5 and pump input pulley 8
A water cooling system for an engine, in which the timing transmission belt 11 is formed by winding the timing belt 10 in series, is characterized as follows.

That is, as exemplified in FIG.
The belt transmission mechanism 11 is housed in a belt case 12 attached to the front side surface 2 of the cylinder block 1, and is shown in FIG.
As shown in FIG. 1, a part of the belt case 12 is led out to the outside along the front side surface 2 of the cylinder block 1, and the water pump chamber 6 is provided on a rear side wall 14 of the lead portion 13. A cooling water introduction pipe 16 for introducing cooling water from the radiator 15 to the rear side of the chamber 6
Is provided.

[0009]

The present invention has the following functions and effects. That is, as illustrated in FIG. 1B, the water pump chamber 6 is arranged on the lateral side of the front side surface 2 of the cylinder block 1, and the cooling water introduction pipe 16 is arranged on the rear side of the water pump chamber 6. Therefore, the cooling fan 9 can be disposed so as to be largely retracted, and as shown in FIG. 1A, the projecting dimension 18 of the cooling fan 9 from the front side surface 2 of the cylinder block 1 is shortened, and Total length can be shortened.

[0010]

An embodiment of the present invention will be described with reference to the drawings.
1 and 2 are diagrams illustrating a water cooling device for an engine according to an embodiment of the present invention. The engine used in this embodiment is an overhead cam type vertical water-cooled two-cylinder gasoline engine.

The structure of this engine is as follows. That is, as shown in FIG. 2, the cylinder head 19 and the head cover 20 are sequentially assembled on the upper side of the cylinder block 1. An oil pan 22 is mounted on the lower side of the cylinder block 1, and a gear case 3 is mounted on a front side of the cylinder block 1. Incidentally, reference numeral 2 in FIG.
3 is a carburetor, 24 is an air cleaner, 25 is an exhaust muffler, and 26 is an oil filter element. FIG.
As shown in FIG. 1A, a valve cam shaft 27 is provided in the cylinder head 20.

The structure of the water cooling system for this engine is as follows. That is, as shown in FIG. 1A, a cylinder jacket 28 is provided inside the cylinder block 1, and a head jacket 29 is provided inside the cylinder head 19, and these are communicated via the communication holes 30. Further, a cooling water discharge pipe 31 is led out from the cylinder head 19,
This is communicated with the upper tank 32 of the radiator 15, and the lower tank 33 is communicated with the cylinder jacket 28 via the water pump chamber 6, as shown in FIG. A pump shaft 7 is inserted into the water pump chamber 6, and a pump blade 34 is attached to the pump shaft 7. Further, a cooling fan 9 is provided on the front side of the engine, and faces the radiator 15 as shown in FIG.

In this water cooling device, the water pump chamber 6
By driving the pump blades 34 inside the both jackets 28.
The cooling water circulates between the radiator 29 and the radiator 15, and the cooling air flows through the radiator 15 by driving the cooling fan 9, and the cooling water is cooled by radiating the cooling air.

The structure of the drive unit for the pump blades 34 and the cooling fan 9 of this water cooling device is as follows. That is, as shown in FIG.
, A gear interlocking mechanism 36 including a crank gear 35 and the like is covered from the front side. A crankshaft end 4 protrudes forward from the gear case 3, and a crank pulley 5 is fitted and fixed to the end thereof.

As shown in FIG. 1B, a pump input pulley 8 is fixed to a pump shaft 7 inserted into the water pump chamber 6, and a cooling fan 9 is mounted on the pump shaft 7 in front of the pump input pulley 8. Has been fixed. As shown in FIG. 2, a timing belt 10 is provided to the crank pulley 5, the pump input pulley 8, and the valve camshaft input pulley 37.
Are wound in series to form a belt transmission mechanism 11. The timing belt 10 is given a predetermined tension by a tension pulley 38. In this drive,
By the rotation of the crank pulley 5, the pump input pulley 8,
The valve camshaft input pulley 37 is interlocked, and the valve camshaft 27, the cooling fan 9, and the pump blade 34 shown in FIG. 1B are driven.

In this embodiment, the following configuration is employed to reduce the overall length of the engine. That is,
As shown in FIG. 2, a belt transmission mechanism 11 is housed in a belt case 12 attached to the front side surface 2 of the cylinder block 1. The belt case 12 extends upward from the gear case 3 and is formed in a triangular shape having tops on the upper, lower, and right sides. The belt case 12 includes a front case portion 39 (see FIG. 1) and a rear case portion 40. The rear case portion 40 is provided integrally with the gear case 3.

As shown in FIGS. 1A and 1B, the rear case portion 40 is formed along the front side surface 2 of the cylinder block 1. As shown in FIG. 1 (B), the right top portion of the belt case 12 is led out to the outside along the front side surface 2 of the cylinder block 1, and the water pump chamber 6 is formed along the rear side wall 14 of the leading portion 13. Is formed. The radiator 1 is located behind the water pump chamber 6.
A cooling water introducing pipe 16 for introducing the cooling water from the cooling water 5 is provided. As a result, the water pump 6 is located on the lateral side of the front side surface 2 of the cylinder block 1 and the cooling water introduction cylinder 16 is arranged behind the water pump chamber 6.
The cooling water fan 9 can be disposed so as to be largely retreated, and as shown in FIG. 1A, the projecting dimension 18 of the cooling fan 9 from the front side surface 2 of the cylinder block 1 is shortened.
The overall length of the engine can be shortened.

In this embodiment, as shown in FIG. 1B, the water pump chamber 6 is
The front part is covered with a front cover 41, an outlet 42 communicating with the cylinder jacket 28 is provided on the left side, and a rear bulging part 43 is provided on the right side. The rear bulging portion 43 is formed in an elbow tubular shape. The pump blade 34 is accommodated at the start end thereof, and a thermostat chamber 44 is provided at the end thereof, and a thermostat 45 is provided therein. Then, the cooling water introduction pipe 16 is led out of the thermostat chamber 44 to the right. A communication pipe 46 connected to the lower tank 33 of the radiator 15 shown in FIG. As a result, the rear bulging portion 4 containing the thermostat 45 in the lateral side space 21 of the cylinder block 1
3 are disposed, and the lateral side space 21, which is originally a dead space, is effectively used, so that the engine is downsized.

The thermostat chamber 44 communicates with a cooling water discharge pipe 31 of the head jacket 19 shown in FIG. Therefore, the low-temperature cooling water from the radiator 15 that has passed through the thermostat 45 and the head jacket 2 that has passed through the bypass passage 47
The high-temperature cooling water from No. 9 is mixed in the thermostat chamber 44, and the opening and closing control of the thermostat 45 is performed based on the temperature of the mixed cooling water. With the existing thermostat that has a thermostat at the cooling water discharge port of the head jacket, the thermostat opens only with the water temperature of the head jacket, and the low-temperature cooling water of the radiator is supplied to the cylinder jacket at a stretch to rapidly cool the high-temperature cylinder. In contrast to this, in this control method, the thermostat 45 opens according to the temperature of the mixed cooling water, and the low-temperature cooling water from the radiator 15 is gradually supplied to the cylinder jacket 28. There is no such defect.

FIG. 3 shows a modification of the above embodiment.
In this modified example, front and rear openings 48 and 49 are formed before and after the head jacket 29 of the cylinder head 19, and front and rear seating surfaces 50 and 51 are formed around these peripheral portions.
8.49 have the same shape and front and rear seating surfaces 50 and 51 have the same shape. The cooling water discharge pipes 31 having the same shape can be attached to and detached from the front and rear seating surfaces 50 and 51, respectively. Other structures are the same as in the above embodiment. In this modified example, normally, the cooling water discharge pipe 31 is attached to the front seating surface 50, and the rear opening 49 is closed with a belch plug 52. Since there is no need to provide a thermostat in the cooling water discharge pipe 31, a compact structure that can be disposed in the gap 53 between the cylinder head 19 and the belt case 12 can be provided.

The rear opening 49 is always higher than the front opening 48 depending on the mounting condition of the engine, or the rear opening 49 is frequently higher than the front opening 48 due to pitching or rolling of the engine. In such a case, the cooling water discharge pipes 31 are attached to both the front and rear seating surfaces 50 and 51, and the two discharge pipes 31 and 31 are joined by a collecting pipe, and the upper part of the radiator 15 shown in FIG. Connect to tank 32. In this manner, when the cooling water discharge pipe 31 is also provided on the rear seating surface 51, even when the rear opening 49 is at a high position, air near the rear opening 49 flows out of the rear cooling water discharge pipe 31, It is possible to prevent air from being trapped near the rear opening 49.

[Brief description of the drawings]

FIG. 1 is a view for explaining a main part of an engine according to an embodiment of the present invention. FIG. 1 (A) is a longitudinal side view, and FIG. 1 (B) is a cross-sectional plan view.

FIG. 2 is a front view of the engine of FIG. 1, with a front case portion of a belt case removed.

FIG. 3 is a view for explaining a modification of the embodiment of FIG. 1, and is a longitudinal sectional side view near a cylinder head.

FIG. 4 is a diagram corresponding to FIG.

[Explanation of symbols] 1 ... cylinder block, 2 ... front side, 3 ... gear case,
4: Crank shaft end, 5: Crank pulley, 6: Water pump chamber, 7: Pump shaft, 8: Pump input pulley,
9: cooling fan, 10: timing belt, 11: belt transmission mechanism, 12: belt case, 13: lead-out part, 1
4 rear wall, 15 radiator, 16 cooling water inlet pipe.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01P 5/10 F02B 67/06 F02F 7/00

Claims (1)

(57) [Claims] 1. A gear case (3) is attached to a front side surface (2) of a cylinder block (1), and a crankshaft end (4) protrudes forward from the gear case (3). (4)
And a pump input pulley attached to a pump shaft (7) inserted into the water pump chamber (6).
(8) is fixed, and a cooling fan (9) is fixed to the pump shaft (7) in front of the pump input pulley (8).
Timing belt (1) is connected to (5) and pump input pulley (8).
0) is wound in series to form a belt transmission mechanism (11), wherein the belt transmission mechanism (11) is attached to the front side surface (2) of the cylinder block (1). The belt case (12) is housed in a case (12), and a part of the belt case (12) is led out to the outside along the front side surface (2) of the cylinder block (1).
The water pump chamber (6) is provided on the rear side wall (14) of the (13), and a radiator is provided on the rear side of the water pump chamber (6).
A water cooling device for an engine, comprising a cooling water introduction pipe (16) for introducing the cooling water from (15).