JPS5815610Y2 - Single cylinder OHV engine lubrication system - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a warming device for a single cylinder OHV engine.

Generally, an 0HV (overhead valve type) engine is equipped with a pressure-feed type warming device to warm valve operating members in a rocker chamber, such as a rocker arm and a rocker arm shaft.

However, it is expensive and uneconomical to equip a single-cylinder OHV engine with a pressure-feeding type heating device. The purpose is to ensure that the valve train parts in the room are kept warm, and for this purpose, a ventilation passage is created that starts at the crank chamber, passes through the rocker room, and ends at the tappet room equipped with a blazer device. The engine is characterized by the fact that a mist-like oil can be actively supplied into the rocker chamber by the ventilation effect of the blazer device in response to pressure fluctuations in the crank chamber.

Examples of this invention will be described below based on the drawings.

FIG. 1 is a sectional view of a main part of a general-purpose single-cylinder forced air-cooled OHV engine.

As shown in the figure, the engine E includes a piston 4, a crankshaft 5, and other external structures that integrally form a cylinder barrel, such as a crankcase 1, a head block 2, and a rocker cover 3.
1. It accommodates moving members such as a camshaft 6, a valve train V driven by the camshaft 6, and intake/exhaust valves 7A and 7B.

The above-mentioned valve train V includes a tappet 9 and a bushing rod 10 that run vertically through the tappet chamber 8, and a bushing rod cover bushing that covers the outer surface of the bushing rod 10 and is installed between the tappet chamber 8 and the rocker chamber 11. It is composed of a shrod insertion hole 12, a rocker arm 13 housed in the rocker chamber 11, a rocker arm shaft 14, a rocker arm bracket 15, and the like.

A reed valve type blazer device 16 is attached to the open end surface of the tappet chamber 8.

The flexible device 16 and the crank chamber 17 are communicated through a ventilation passage P passing through the locker chamber 11.

This ventilation passage P is connected to first and second passages Pi and P2 formed in the cylinder peripheral wall and the inner wall of the head block 2, respectively, in order to communicate the crank chamber 17 and the lowest part of the rocker chamber 11. , a rocker chamber 11 , a space within the bushing rod cover 12 , and a tappet chamber 8 .

No. 1 above. As shown in FIG. 2, the second passages Pi and P2 are formed in two in parallel in the front and rear.

In the figure, reference numeral 18 is a spoon for scooping up oil, 19 is a pleather pipe that guides blow-by gas to the air cleaner 20,
21 is an oil return hole connected to the bottom wall of the tappet chamber 8.

The diameter of this oil return hole 21 is 1 to 211! #! When the first and second passages P1. The hole diameter of P2 is set to approximately 6.5 mm.

As described above, when the ventilation passage P is formed via the rocker chamber 11, the mist-like oil filling the crank chamber 17 is reliably removed from the rocker chamber by moving the flow-by gas.
1, thereby locking the rocker and arm 13.
and the rocker arm shaft 14 can be sufficiently warmed.

Furthermore, since the direction of gas movement is reversed within the locker chamber 11,
Most of the mist oil is liquefied in the same chamber 11, and the first,
It flows down into the crank chamber 17 via the second passages P1 and P2.

Furthermore, even if the button is pressed in the tappet chamber 8, mist-like oil is separated due to a sudden change in the cross-sectional area of the ventilation passage, but the liquefied oil flows through the oil return hole 21 to the crank chamber 17.
Flow inward.

FIG. 3 shows another embodiment.

In this case, between the oil return hole 21 and the crank chamber 17,
A buffer chamber 22 filled with steel wool is provided.

As explained above, in this invention, in a single cylinder OHV engine, a ventilation passage for discharging blow-by gas to the outside is formed via the rocker chamber. The mist-like oil that fills the room is moved into the rocker chamber along with the ventilation flow to warm the valve operating parts such as the rocker arm and rocker arm shaft. Not only can the device be obtained, but also the valve train members can be positively and reliably warmed.

Furthermore, in the present invention, the blazer device is formed facing the tappet chamber, and the rocker chamber and the tappet chamber are communicated with each other through the bushing rod insertion hole. As it flows down the narrow space between the blow-by gas and the outer circumferential surface, it comes into contact with the inner wall of the insertion hole and the outer circumferential surface of the bushing rod, and the oil contained in the blow-by gas adheres to and is removed from the inner wall of the insertion hole and the outer circumferential surface of the bushing rod. It is possible to improve the efficiency of removing oil from blow-by gas.

Furthermore, since an oil pump and a transmission member for driving the oil pump are not required, the weight of the engine can be reduced accordingly.

[Brief explanation of drawings]

The drawings show an embodiment of this invention; Fig. 1 is a sectional view of the main part of a single-cylinder OHV engine, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1,
FIG. 3 is a sectional view of main parts showing another embodiment. 8...Tappet room, 11...Rocker room, 16...Furezer device, 17...Crank room, P...Ventilation passage.

Claims (1)

[Scope of utility model registration request] A tappet chamber 8 is formed on the outer surface of the crank chamber 17 of a vertical overhead valve single-cylinder engine, and a flare device 16 is mounted facing the tappet chamber 8.
1 through an oil return hole 21, and the rocker chamber 1 located on the crank chamber 11 and the cylinder head.
1 and a ventilation passage P formed to have a larger diameter than the oil return hole 21.
A heating device for a single cylinder OHV engine, characterized in that a rocker chamber 11 and a tappet chamber 8 are communicated with each other through a bushing rod insertion hole.