JPS6316808Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a valve lubrication structure for an OHV vertical engine, which is intended to reduce oil consumption and ensure lubrication especially around the exhaust valve.

As a type of general-purpose engine, an OHV type vertical engine in which intake and exhaust valves are arranged horizontally has been put into practical use, and the lubricating oil passage for valve lubrication of such an engine is located at the intake port where the temperature conditions of the cylinder and cylinder head are mild. It is installed through the side.

However, if the lubricating oil passage is opened near the intake valve in the Rotsuker arm chamber,
Most of the oil is drawn toward the intake valve due to the negative pressure in the intake port, which increases oil consumption and causes insufficient lubrication around the exhaust valve.

The present invention was developed to eliminate such inconveniences, and its purpose is to improve the lubricating oil passage on the intake valve side in the Rocker arm chamber in this type of OHV vertical engine. The object of the present invention is to provide a valve lubrication structure that prevents more oil from flowing than necessary, reduces oil consumption, and at the same time ensures lubrication around the exhaust valve.

In order to achieve the above object, the present invention has been developed to provide a passageway between the cylinder of an OHV type vertical engine in which intake and exhaust valves are arranged horizontally and a head cover thereof, and an opening above the exhaust valve in the rocker arm chamber. The gist is that a lubricating oil passage is formed to

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional plan view of the engine, FIG. 2 is a side view of the same, FIG. 3 is a vertical cross-sectional side view of the cylinder and cylinder head, and FIG. 4 is a front view of the cylinder head.

Engine 1 has a crankshaft 11 as shown in the diagram.
It is a vertical engine that is supported vertically and cantilevered at the bottom, with the cylinder 4 facing horizontally and the crankcase 3 facing vertically, and the crankcase 3, cylinder 4, and cylinder head 5 are all cast as one piece. A cylinder barrel 2 is formed, and a crankcase cover 6 made of a steel plate is attached to an opening 3a cut diagonally from the base of the cylinder 4 in the upper part of the crankcase 3.

On the other hand, a piston 15 sliding inside the cylinder 4 is connected to a crank pin 12 of a crankshaft 11 via a connecting rod 16.
1 is a shaft part 13 forming the lower part of the shaft part 13, which is vertically cantilevered on the crankcase 3, and an oil slinger 19 is located near the end of a horizontally supported camshaft 17 which is orthogonal to the shaft part 13 and engages with gears. The rotation of the oil slinger 19 scrapes up the oil accumulated at the bottom of the crank case 3 toward the crank web 14, turns the oil into a mist in the crank chamber C, and lubricates the inside of the engine 1 as is known.

In addition, two left and right intake/exhaust valves 21 and 31 are arranged horizontally in the cylinder head 5, and each valve 2
Valve springs 23, 33 are compressed between the head 5 and retainers 22, 32 fitted to the ends of the stems 21a, 31a, respectively.
34, and the tips of push rods 25, 35 are engaged with the lower ends of each arm 24, 34, respectively. The cylinder head 5 is provided with a cylinder head cover 7 made of a steel plate that covers the valve drive system.
is attached, thereby forming a rocker arm chamber R inside the head cover 7.

The push rods 25, 35 are inserted into passages 8, 9 formed at the bottom of the cylinder 4 and the cylinder head 5, and the lifters 26, 36 connected to the base ends of the push rods 25, 35 are connected to the cams 18, 18 of the camshaft 17. are engaged with each other.

In the OHV type vertical engine 1 in which the intake and exhaust valves 21 and 31 are arranged horizontally in parallel as described above,
In the present invention, first, in order to guide oil from the crank chamber C side to the rocker arm chamber R side, the cylinder 4 and cylinder head 5 are connected as shown in FIGS. 1 and 2.
A lubricating oil passage 41 is formed through the upper corner of the intake port 51 side. This lubricating oil passage 41 is inclined so that the opening 42 that opens toward the crank chamber C side is at the lower side, and the upper rocker arm chamber R side opening 43 opens at the upper end surface 53 of the peripheral wall 52 of the cylinder head 5. ing.

An exhaust valve 3 is attached to the upper end surface 53 of the cylinder head peripheral wall 52 as shown in FIGS. 3 and 4.
A groove 56 having a U-shaped cross section is formed up to the upper part of the groove 5.
6 is communicated with the side of the opening 43 of the lubricating oil passage 41, and is bent 57 toward the exhaust side rocker arm 34 to form an opening 58 facing directly above the rocker arm 34.

Attach the cylinder head cover 7 to the end face of the cylinder head peripheral wall 52 using its peripheral piece 71 and seal the gasket 7 with the cylinder head cover 7.
As shown in FIG. A new lubricating oil passage 55 is formed laterally by closing with the piece 72.

Next, the operation of the above valve lubrication structure will be described.

First, mist-like oil in the crank chamber C is forced into the lubricating oil passage 41 by the pulsating pressure in the crank chamber C during engine operation, passes through the passage 41 provided on the intake port 51 side where the temperature condition is gentle, and then flows into the cylinder. The oil flows into the rocker arm chamber R through a new horizontal lubricating oil passage 55 formed in the upper part between the head 5 and the head cover 7 through a downward opening 58 facing directly above the exhaust side rocker arm 34.

From this opening 58, the stem 31a of the exhaust valve 31, the retainer 32, and the rocker arm 34 are exposed.
The oil is reliably dripped onto the top, and the area around the exhaust valve 31 is well lubricated, and the high-speed rocking of the exhaust valve 31, rocker arm 34, etc. causes the oil to become mist again and float inside the rocker arm chamber R. This also lubricates the area around the intake valve 21. In this way, the intake valve 21
Since oil does not drip directly to the intake valve 21 side and no more oil than necessary goes to the intake valve 21 side, wasteful oil consumption can be prevented.

Further, the new lubricating oil passage 55 can be formed by simply installing a U-shaped groove 56 horizontally in the cylinder head 5 and closing this with the head cover 7, so that machining is easier than using a through hole.

As is clear from the above description, according to the present invention, a lubricating oil passage 41 is formed on the intake port 51 side of the cylinder 4 and cylinder head 5 of the engine 1, with one opening 42 opening in the crank chamber C. The other opening 43 of the oil passage 41 is connected to one end of a lubricating oil passage 55 formed between the cylinder head 5 and its head cover 7, and the lubricating oil passage 5
The opening 58 at the other end of the exhaust side rocker arm 34
Since the oil mist in the crank chamber C is supplied to the rocker arm chamber R through the lubricating oil passages 41 and 55, the oil can be actively sent to the exhaust valve side. In addition to ensuring lubrication around the exhaust valve,
Oil consumption can also be reduced because no more oil than necessary goes to the intake valve side.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional plan view of the engine, FIG. 2 is a side view thereof, FIG. 3 is a vertical side view of the cylinder and cylinder head, and FIG. 4 is a front view of the cylinder head. In the drawing, 1 is the engine, 4 is the cylinder, 5 is the cylinder head, 7 is the head cover, 11 is the crankshaft, 21 and 31 are the intake and exhaust valves, and 24
34 is an intake side rocker arm, 34 is an exhaust side rocker arm, 41 is a lubricating oil passage, 42, 43 are its openings, 55 is another lubricating oil passage, 58 is its opening, C
is the crank chamber, and R is the Rocker arm chamber.

Claims (1)

[Scope of Claim for Utility Model Registration] In an OHV type vertical engine in which intake and exhaust valves are arranged horizontally, one opening 42 is provided in the crank chamber C on the intake port 51 side of the cylinder 4 and cylinder head 5 of the engine 1. The other opening 43 of this lubricating oil passage 41 is connected to one end of a lubricating oil passage 55 formed between the cylinder head 5 and its head cover 7, and the lubricating oil passage 55 is opened. The opening 58 at the other end faces directly above the exhaust side rocker arm 34, so that the mist-like oil in the crank chamber C is directed to the lubricating oil passages 41, 55.
A valve lubrication structure for an OHV type vertical engine, characterized in that the valve lubrication is supplied to the rocker arm chamber R via the valve lubrication structure.