JPH01151708A - Cooling structure of engine - Google Patents

Abstract

PURPOSE:To rotate cooling liquid to cause radiation and cooling thereof so as to disuse a radiator or the like by providing a rotary member on the rotary shaft of an engine, and circulating the cooling liquid pressure-fed by a pump to a cooling passage, through a radiation passage formed on the rotary member. CONSTITUTION:An engine 1 has a cooling passage 101 which supplies cooling liquid pressure-fed by a pump 25 to required portions. In this cooling structure, a rotary member 37 which has a required diameter and rotates unitedly with a rotary shaft 13 is provided on a part projecting from the engine case 3 of the rotary shaft 13 driven by the engine 1. A radiation passage 71 for cooling liquid is formed with a necessary length on the rotary member 37. The radiation passage 71 and the cooling passage 101 are communicated with each other through a connection passage 121 formed on the rotary shaft 13, so that the cooling liquid pressure-fed from the pump 25 is circulated to the cooling passage 101 through the radiation passage 71. Thus, the rotation of the radiation passage 71 causes the radiation and cooling of the cooling liquid flowing therethrough.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine cooling structure, and more particularly to an engine cooling structure that performs cooling using a liquid such as water or lubricating oil.

(Prior art) A system that cools the engine by supplying liquid such as water or engine lubricating oil to appropriate locations using a pump was developed in Utility Model Application No. 58-3.
It is known from Publication No. 7920, etc.

And in those that use liquid to cool the engine,
A liquid passage (such as a quarter jacket) is formed around the cylinder, and the liquid flowing through this liquid passage provides a sound insulation function.

Therefore, an engine that uses liquid for cooling is advantageous not only in terms of cooling, but also in terms of reducing engine noise.

However, a water-cooled engine that uses water is provided with a radiator, and an engine that uses lubricating oil is provided with an oil cooler as disclosed in Japanese Utility Model Application No. 61-92713, that is, to lower the temperature of the liquid. A heatsink for this purpose is required separately from the engine body.

(Problem to be solved by the invention) Therefore, although the conventional structure can reduce engine noise, it is necessary to secure space for radiator installation separately from the engine body, which increases the size of the engine and reduces the number of parts. This problem is increasing, especially since general-purpose engines installed in various types of work machines are required to be more compact.

The present invention has been devised in view of the above circumstances, and the purpose of the present invention is to reduce the temperature of the engine cooling liquid by omitting the conventional radiator and oil cooler, and to achieve compactness and a reduction in the number of parts. The purpose of the present invention is to provide an engine cooling structure that can improve the efficiency of engine cooling.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cooling structure for the engine 1, which includes a cooling passage 101 for cooling the engine by supplying engine cooling liquid to appropriate locations using the pump 25. A rotating member 37 of a required diameter that rotates integrally with the rotating shaft 13 is provided on a portion of the rotating shaft 13 that rotates due to the drive of the engine 1 and protrudes from the engine case 3, and the rotating member 37 is provided with an engine cooling liquid. A heat radiation passage 71 is provided with a required length, and the cooling passage 101 and the heat radiation passage 71 are connected, and the engine cooling liquid pumped from the pump 25 is transferred to the heat radiation passage 7.
1 and returning to the cooling passage 101 is provided on the rotating shaft 13.

(Function) The rotating member 37 and the heat radiation passage 7 are driven by the engine 1.
1 rotates, and the temperature of the engine cooling liquid flowing through the heat radiation passage 71 is lowered.

The rotating member 37 and the heat dissipation passage 71 can be arranged compactly on the side of the engine case 3, so there is no need to secure a space separately from the engine case 3 for arranging the radiator and oil cooler as in the past. , the engine 1 can be made more compact.

The conventional radiator, cooling fan, and oil cooler can be omitted, and the rotating member 37 and the heat dissipation passage 71 can be easily constructed, so that the number of parts can be reduced.

Since the cooling passage 101 and the heat radiation passage 71 are connected using the rotating shaft 13, the engine cooling liquid can be received between the cooling passage 101 and the heat radiation passage 71 with a simple configuration without increasing the number of parts. Delivery can be made.

Furthermore, if a crankshaft is used as the rotating shaft 13 or a flywheel is used as the rotating member 37, the cooling structure can be configured without increasing the number of parts accordingly.

Further, if engine lubricating oil is used as the engine cooling liquid, it is possible to lubricate and cool each part of the engine.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional side view of a main part of the engine, and FIG. 2 is a view taken along the line II--II in FIG. 1.

1 is a general-purpose engine, 3 is an engine case, and engine 1
is a liquid-cooled engine that uses lubricating oil to lubricate and cool various parts of the engine.

The engine case 3 includes a cylinder block 5, a cylinder head 7, and the like.

The cylinder block 5 is provided with a cylinder 9 and a crank chamber 11, and the crank chamber 11 is provided with a crankshaft 13.

15 is a camshaft, and the camshaft 15 is rotated by meshing with a gear 17 and a crankshaft gear (not shown).

Cam shaft 15 is formed with cam portions 21A and 21B for opening and closing intake valve 19A1 and exhaust valve 19B.

One end of the camshaft 15 is supported by a bearing portion 23 of the cylinder block 5, and an oil pump 25 is provided at the other end of the camshaft 15.

The oil pump 25 is arranged by attaching a pump case 27 to a plate 29 on the side of the engine case 3 with bolts 31, and uses the camshaft 15 as a drive shaft of the oil pump 25.

The crankshaft 13 has one journal portion 33 supported by a bearing portion 35 of the cylinder block 5, and the end portion of the crankshaft 13 is supported by a bearing portion 35 of the cylinder block 5.
The crank chamber 11 is made to protrude outward from the crank chamber 11.

37 is a flywheel, and the flywheel 37 is attached to the protruding portion 39 of the crank 1M13 via a nut 41.

The flywheel 37 is composed of two divided bodies 43 and 45 that can be divided in the axial direction of the crankshaft 13.

The inner divided body 43 located on the cylinder block 5 side is made of a magnetic material such as FC material, and the outer divided body 45 located on the end side of the crankshaft 13 is made of a material with high thermal conductivity such as an aluminum alloy material. The outer peripheries of both the divided bodies 43 and 45 are fastened together with bolts 47.

The inner divided body 43 includes a boss portion 49, a disk portion 51 that bulges outward in the radial direction from the boss portion 49, and a cylindrical portion 53 that extends from the outer periphery of the disk portion 51 toward the cylinder block 5 side.

A starter gear 55 is attached to the cylindrical portion 53, and magnets 59 housed in a holding member 57 at intervals in the circumferential direction are attached via screws 61 and a holding plate 63. A stator coil is disposed on the radially outer side of 43, and the inner divided body 43 is used as a rotor of the generator.

Reference numeral 71 denotes a heat radiation passage for lowering the temperature of the lubricating oil, and the heat radiation passage 71 is provided in the flywheel 37.

The heat dissipation passage 71 is composed of a lubricating oil-filled lower 3, a maze-like passage 75, a lubricating oil outlet lower 7, and the like.

Two lubricating oil-filled lowers 3 are formed on the inner circumferential surface 49A of the boss portion of the inner divided body 43, and a mating surface 79 of the inner divided body 43 extends radially outward from each lubricating oil filled lower 3 on the outer periphery of the mating surface 79 of the inner divided body 43. A passage 83 having an opening 81 is provided in the section.

The outer divided body 45 includes a boss portion 85, a disk portion 87 that bulges outward in the radial direction from the boss portion 85, and a cylindrical portion 89 that extends from the outer periphery of the disk portion 87 to the inner divided body 43. , boss part 85
is fitted into the boss portion 49 via the O-ring 90, and the disc portion 87 is positioned and attached to the end side of the crankshaft 13.

A plurality of cooling fins 91 are formed on the outer surface of the disc portion 87 at intervals in the circumferential direction.

Further, as shown in FIG. 2, a plurality of arc-shaped wall portions 95 bulging toward the mating surface 93 are formed on the inner surface of the disc portion 87 at intervals in the radial direction. The notches 97 are formed as appropriate by shifting the phase.

The maze-like passage 75 communicates with the mating surface 79 of the inner dividing body 43, the inner surface of the disk portion 87, the wall portion 95, the boss portion 49, and the boss portion 85 from the inner circumference to the outer circumference of the flywheel 37. Let it form.

The opening 81 is located on the outer periphery of the maze-like passage 75, and the boss portion 49 is formed with two passages 99 extending radially inward from the inner periphery of the maze-like passage 75.
are opened on the inner circumferential surface 49A of the boss portion to form two lubricating oil outlet lower parts 7.

Next, a cooling passage 10 for lubricating oil that lubricates and cools the engine.
1 will be explained.

The cooling passage 101 connects the camshaft 1 to the oil pump 25.
A passage 103 inside the cylinder block 5, a passage 105 formed in the side wall of the cylinder block 5 and communicating with the passage 103 and having an opening 105A on the bearing inner circumferential surface 35A, an annular groove formed in the bearing inner circumferential surface 35A and sandwiched between oil seals 107. 109, a passage 111 extending from the annular groove 109 to the cylinder head 7 side;
, a passage 113 formed around the cylinder 9, etc.

Particularly in the cooling passage 101, engine noise is reduced by the lubricating oil flowing through the passage 113 formed around the cylinder 9.

The heat radiation passage 71 and the cooling passage 101 are connected to the crankshaft 13.
The connection is made through a connection path 121 formed inside.

The connecting passage 121 is composed of a first passage 123 that communicates the opening 105A with the lubricating oil inlet 73, and a second passage 125 that communicates the lubricating oil outlet lower 7 with the annular groove 109.

Annular grooves 127, 129, and 131 are formed on the outer circumferential surface of the crankshaft 13 in a portion facing the opening 105A and the lubricating oil lower 3, and in a portion facing the lubricating oil outlet lower 7, so that the lubricating oil lower 3 and the lubricating oil O-rings 133 are fitted on both sides of the annular grooves 129 and 131 facing the lower protrusion 7.

Next, the flow of lubricating oil will be explained.

The engine 1 drives the crankshaft 13 and the flywheel 37, and the rotation of the camshaft 15 drives the oil pump 25.

The lubricating oil flows from the oil pump 25 to the heat radiation passage 71 via passages 103 and 105 and the first passage 123.

The heat radiation passage 71 is rotating, and the heat radiation passage 71 is rotating.
In this case, heat is radiated and cooled from the lubricating oil in approximately proportion to the rotational speed, and the temperature of the lubricating oil is lowered.

In the embodiment, the heat dissipation passage 71 is constituted by a maze-like passage 75 to ensure a large surface area, the heat dissipation fins 91 are formed, and the outer dividing body 45 is made of a material with high thermal conductivity. The temperature of the lubricating oil can be lowered more efficiently.

Next, the lubricating oil flows from the heat radiation passage 71 to the second passage 125,
The respective lubricating parts are supplied via channels 111,113.

In the embodiment, between the passage 105 and the first passage 123,
Since the lubricating oil is transferred between the second passage 125 and the annular groove 109, the journal portion 33 of the crankshaft 13
lubrication is also performed at the same time.

Therefore, according to this embodiment, the heat dissipation passage 71 can be arranged compactly on the side of the engine case 3, and therefore, the space for arranging the radiator and oil cooler can be saved separately from the engine case 3 as in the conventional case. There is no need to secure it, and the engine 1 can be made more compact.

In addition, since the heat radiation passage 71 is rotating, even when the engine 1 is mounted on a working machine such as a lawn mower,
Unlike the conventional radiator type, there is no problem of being covered with foreign matter such as grass, and the conventional radiator, cooling fan, and oil cooler can be omitted, and the heat dissipation passage 71 can be easily configured, so the number of parts can be reduced. can be achieved.

In addition, since the cooling passage 101 and the heat radiation passage 71 are connected using the crankshaft 13, the cooling passage 101 and the heat radiation passage 1 can be easily configured without increasing the number of parts.
The lubricating oil can be transferred between 7.

Furthermore, if the crankshaft 13 is used as the rotating shaft and the flywheel 37 is used as the rotating member as in the embodiment, the cooling structure can be configured without increasing the number of parts accordingly.

Further, if engine lubricating oil is used as the engine cooling liquid as in the embodiment, it is possible to lubricate and cool various parts of the engine.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the figure, the same members and locations as in the first embodiment are given the same reference numerals.The second embodiment differs from the first embodiment in that the heat radiation passage 271 is constructed using two pipes. .

213 is the crankshaft, 237 is the flywheel, 271
is a heat radiation passage.

The flywheel 237 includes a boss portion 249 that is fitted onto the crankshaft 213, a disk portion 251 that bulges outward in the radial direction from the boss portion 249, and a disk portion 251 that extends from the outer periphery of the disk portion 251 toward the cylinder block 5 side. A cylindrical part 253 is provided, and a disc part 2
A holding member 256 is attached to the outer peripheral edge of the outer surface of 51.

The heat radiation passage 271 has a lubricating oil population 273 and a spiral passage 2.
75, a lubricating oil outlet 277, etc.

The spiral passage 275 is formed by spirally bending a single tube body 276, and is joined to the outer surface of the disk portion 251 between the outside of the boss portion 249 of the flywheel 237 and the inside of the holding member 256. establish.

The heat radiation passage 271 is communicated with the cooling passage 101 through a connection passage 321 formed inside the crankshaft 213.

That is, the lubricating oil population 273 is formed in the flywheel 237 in communication with the first passage 323 of the crankshaft 213, and the lubricating oil population 273 and the pipe body 276 are formed in the flywheel 237.
A passage 283 is formed that connects the outer peripheral end 276A of the.

The lubricating oil outlet 277 is connected to the second passage 325 of the crankshaft 213.
A passage 299 is formed in the flywheel 37 to connect the lubricating oil outlet 277 and the inner peripheral end 276B of the tube body 276.

The function and effect of dissipating heat from the lubricating oil through the heat dissipation passage 271 and making the engine more compact are the same as in the first embodiment.

In the first and second embodiments, the case where the crankshaft 13.213 was used as the rotating shaft and the flywheel 37.237 was used as the rotating member was explained, but the rotating shaft and the rotating member are those of the embodiment. It is not limited to , but is optional.

Moreover, a liquid such as water may be used as the engine cooling liquid.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, the temperature of the engine cooling liquid can be lowered by omitting the conventional radiator and oil cooler, and it is possible to reduce the size and number of parts. It is possible to obtain a cooling structure for the engine that can
It is particularly suitable for use in general-purpose engines.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a main part of an engine, FIG. 2 is a view taken along the line II--II in FIG. 1, and FIG. 3 is a cross-sectional side view of a main part of an engine according to a second embodiment. In the figure, 1 is the engine, 3 is the engine case, 13 is the crankshaft, 25 is the oil pump, 37.237 is the flywheel, 71.271 is the heat radiation passage, 121.321
is a connecting path.

Claims (4)

[Claims] (1) In an engine cooling structure equipped with a cooling passage that cools the engine by supplying engine cooling liquid to appropriate locations using a pump, a shaft that rotates when driven by the engine protrudes from the engine case. A rotating member of a required diameter that rotates integrally with the rotating shaft is provided, a heat radiation passage for engine cooling liquid is provided in the rotary member with a required length, the cooling passage and the heat radiation passage are connected, and the heat radiation passage is pressurized from a pump. An engine cooling structure, characterized in that the rotary shaft is provided with a connecting path for returning the engine cooling liquid to the cooling passage through the heat radiation passage. (2) The engine cooling structure according to claim 1, wherein the rotating shaft is a crankshaft. (3) The engine cooling structure according to claim 1, wherein the rotating member is a flywheel. (4) The engine cooling structure according to claim 1, wherein the engine cooling liquid is an engine lubricating oil.