JPS5849380Y2 - Agricultural forced air-cooled side valve engine - Google Patents

Description

[Detailed description of the invention] The purpose of the invention is to improve the performance of removing dust such as straw waste, as well as the cooling performance of a forced air-cooled side valve engine installed in agricultural machinery such as combine harvesters and binders.

Conventionally, in order to improve the contact between the cooling air and the fins,
There were almost no gaps between the fins of the cylinder body and the baffle plate, and between the fins of the cylinder head and the fan cover.

As a result, during agricultural work, straw debris and the like were carried by the cooling air, clogging the fins and dirt floor, causing the engine to overheat, and causing the straw debris to catch fire and cause a fire.

Moreover, the cooling performance was also poor due to the high ventilation resistance and low air volume.

In order to eliminate these drawbacks,
As disclosed in the above issue, it was considered to create a gap between the fins of the cylinder head and the upper plate of the fan cover, and to discharge straw waste etc. from this gap.

However, simply leaving gaps like this increases the ventilation cross-sectional area, lowers the wind speed, and makes contact between the cooling air and the fins worse, further reducing cooling performance. Accumulated tAt caught on the leading edge of the fin
However, they still have the disadvantage of overheating the engine and causing a fire.

In order to eliminate such drawbacks, the present invention forms a foreign matter passage gap between the fins of the cylinder head and the upper plate of the fan cover, and widens the entrance of this gap and narrows the outlet. Allowing straw waste etc. to easily flow into the gap,
By exhausting the air vigorously to the outside while accelerating, and by narrowing the gap outlet, the cooling air pressure inside the fan cover is increased, and the contact between the cooling air and the fins is improved, and the main flow of the cooling air is transferred to the side valve. This is to bring the cylinder closer to the intake and exhaust block, which is the hottest part of the cylinder body.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a crankcase, and an air-cooled side valve type cylinder body 2 and a cylinder head 3 are placed and fixed in this order on the upper side of the crankcase.

The cylinder portion 2a of the cylinder body 2 is placed on the right side, and the intake and exhaust block portion 2bH is placed on the left side.

A cooling fan 4 is fixed to the front end protrusion of the crankshaft 5 on the front side of the crankcase 1.

The front circumferential parts of the fan 4, cylinder body 2, and cylinder head 3 are covered with a fan cover 7, and a cooling air intake port 6 is opened at the front of the lower half of the fan cover 7, and a cooling air outlet 13 is opened at the back of the upper half of the fan cover 7. It opens facing the front of the cylinder body 2 and cylinder head 3.

The windward side of the cooling air outlet faces the cylinder portion 2a, and the leeward side faces the intake/exhaust block portion 2b.

Fins 2' are protruded from the cylinder portion 2a of the cylinder body 1 in multiple vertical stages so as to run back and forth.

The fins 2' are covered with an air guide plate 8, and the starting end of the air guide path 14 in the air guide plate 8 is connected to the cooling air outlet 13 of the fan cover 7.
The end portion thereof communicates with the atmosphere at the back surface of the cylinder portion 2a.

A foreign matter passage gap C with a width of 5 mm or more is formed between the baffle plate 8 and the tip end edge of the cylinder fin 2'.

Fins 3' run in the front-rear direction on the upper surface of the cylinder head 3 and protrude in parallel from side to side.

The upper front corner of the head fin 3' is formed in a concave arc slope downward in the front.

The terminal end of the upper plate portion 7' of the air outlet 13 for cooling the fan cover 7 is located above the slanted front lens corner, and
The upper plate part 7' is formed in a linear plane in the longitudinal direction substantially parallel to the cylinder head 3, with its starting end located on the front side of the front edge of the head fin 3'.

A foreign matter passage gap a is formed between the linear upper plate portion 7' and the inclined front ball corner of the head fin 3'.
The inlet 15 is wide and the outlet 16 is narrow, and the outlet width is 5 mm or more.

FIG. 3 shows a modification of FIG. 2, in which the head fin 3'
The slope of the upper front corner of the front corner has been changed from an arc to a straight line.

Next, to explain its operation, even if the cooling air blown by the cooling fan 4 contains foreign matter such as straw, the foreign matter passage gap a between the fan cover 7 and the cylinder head 3
Also, foreign matter does not flow out through the passage gap C between the cylinder head main body 2 and the baffle plate 8 and become clogged.

Further, even if straw waste is caught on the fins 2', 3', etc., it is easily blown away by the cooling air and does not remain in the ventilation passage.

In addition, in this case, the main flow of the cooling air that has been pressurized and turned into a swirling flow within the fan cover 7 flows as shown in A in FIG.
It flows toward the intake/exhaust block side where the temperature is highest.

This is because the fan cover 7 has only its linear upper plate portion 7'.
Since it overlaps the end of the cylinder head 3 and the front upper corner of the fin 3' is slanted, the air guide plate is disposed close to the entire upper surface of the conventional cylinder head 3. Compared to the case where there is a fan cover 7, there is less resistance to the air flowing over the cylinder head 3, and the flow direction regulating action by the fins 3' is smaller, and the cooling air is blocked from flowing according to the direction of rotation within the fan cover 7. Therefore, the mainstream of the swirling cooling air is directed toward the intake/exhaust block side.

Therefore, in this case, the high temperature side of the cylinder head 3 is easily cooled efficiently.

Furthermore, since the fan cover 7 overlaps only the end of the cylinder head 3, most of the cylinder head 3 is exposed upward, making operations such as repairing the cylinder head 3 and replacing the plug 12 easier. There is.

However, even if the end of the fan cover 7 is arranged to extend above the cylinder head 3 with a large gap as shown by the imaginary line 7 in FIG. There is no difference.

The present invention operates as described above, and for the reasons detailed below, it improves the performance of removing dust such as straw waste, eliminates engine overheating and fire occurrence, and improves cooling performance. , the engine output can be improved, and the allowable continuous operation time can be extended.

(a) Since the entrance of the foreign matter passage gap between the head fin and the upper plate of the fan case is wide, straw waste and the like are less likely to get caught on the front edge of the head fin and easily flow into the foreign matter passage gap.

Moreover, since the foreign matter passage gap becomes narrower on the exit side, straw waste and the like are gradually accelerated within the foreign matter passage gap and are blown out with force.

Moreover, since the outlet of the foreign matter passage gap is narrow, the cooling air pressure inside the fan cover increases, and straw waste and the like are blown out to the outside more forcefully.

Due to these synergistic effects, dust removal performance is extremely high.

(b) In addition to covering the circumference of the cylinder body with an air guide plate, the upper plate of the fan cover is formed into a linear plane in the front and back direction that is almost parallel to the cylinder head, which gives directionality to the cooling air and allows the fan to The cooling air pressure inside the cover can be increased, and the cooling air comes into strong contact with the head fins, which become hot, and provides powerful cooling.

Moreover, the cooling air is guided straight through the linear upper plate portion and continues to make sufficient contact with the head fins from the front to the rear, thereby providing good cooling.

Moreover, since the cooling air pressure inside the fan cover is high, the main flow of the cooling air approaches the intake/exhaust block, strongly cooling the wall of the exhaust port, which becomes particularly hot.

Due to the synergistic effect of the above, the cooling performance of the engine is extremely high.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view, and FIGS. 2 and 3 are side views of the fan cover in a longitudinal section. 1... Crank case, 2... Cylinder body, 2a... Cylinder part of 2, 2b...
...Intake and exhaust block, 2'...2a fin, 3...Cylinder head, 3'...3
fins, 4...cooling fan, 7...
Fan case, 7'...7 upper plate part, 8...
...Air guide plate, 13...Cooling air outlet, 14.
...Air guide path, 15...Entrance of the head side foreign matter passage gap, 16...Outlet of the head side foreign matter passage gap, a...Head side foreign matter passage Gap, b...
...upper corner of 3', C... foreign object passage interval on the cylinder body side.

Claims (1)

[Scope of utility model registration request] An air-cooled side valve type cylinder body 2 and a cylinder head 3 are fixed in order on the crankcase 1, and the cylinder part 2a and intake/exhaust block part 2b of the cylinder body 2 are arranged on the left and right,
A cooling fan 4 is arranged on the front side of the crankcase 1, and a cooling air outlet 13 of a fan cover 7 that covers the cooling fan 4 is opened so as to face the front surface of the cylinder body 2 and the cylinder head 3. A baffle plate 8 is opened so that the upper side in the direction of rotation of the cooling fan faces the cylinder part 2a, and the lower side in the direction of rotation of the fan faces the intake/exhaust block part 2b, and covers the fins 2' of the cylinder part 2a of the cylinder body 2. The air guide path 14 inside is connected to the cooling air outlet 1 of the fan cover 7.
3, a foreign matter passage gap C is formed between the baffle plate 8 and the tip end edge of the cylinder fin 3', and the cylinder head 3 is connected to the cylinder head 3.
The fins 3' protruding from the top surface run in the front-rear direction and are arranged in parallel on the left and right, the front upper corner of the head fin 3' is formed in a downwardly inclined shape, and the upper side of this inclined front ball corner is formed. The terminal end of the upper plate part 7' of the cooling air outlet 13 of the fan cover 7 is positioned, and this upper plate part 7' is shaped into a linear plane in the longitudinal direction that is approximately parallel to the cylinder head 3. The starting end of the section T' is located in front of the front edge of the head fin 3', and the entrance of the foreign matter passage gap a is formed between the linear upper plate section 7' and the inclined upper corner of the head fin 3'. 15 wide, exit 16
A forced air-cooled side valve engine for agricultural use, characterized by having a narrow shape.