JPS6024888Y2 - Lubricating device between engine piston and connecting rod small end - Google Patents

Description

[Detailed description of the invention] The purpose of the invention is to improve the lubrication performance of a device that lubricates the part that connects the piston and the small end of the connecting rod using droplets of lubricating oil that are scattered inside the engine crankcase. .

At the part that connects the engine piston and the small end of the connecting rod, the clay content of the lubricating oil decreases due to engine combustion heat.
Not only is it easy to run out of the oil film, but it is also high up and difficult for lubricant droplets to reach, so the connected parts tend to lack lubrication.
It wears out or seizes prematurely, shortening its lifespan.

Therefore, the present inventor considered what is shown in FIG. 9 prior to the present invention.

The small end 7a of the connecting rod 7 removes the lubricating oil droplets that are about to drip after adhering to the ceiling wall 5a inside the piston 5.
This is a lubricating device in which a rib 31 is integrally formed from a ceiling wall 5a of a piston 5 to guide a lubricating oil supply hole 30 formed in an upwardly expanding shape at the upper end.

In this structure, since the feed rod 7 swings as the piston 5 moves up and down, the lubricating oil supply hole 30 provided in the small end 7a of the connecting rod 7 also swings constantly, so that the lubricating oil dripping from the rib 31 is reliably supplied. The lubricating oil is no longer poured into the lubricating oil supply hole 30.

This invention was proposed to eliminate the above drawbacks.
An oil passage hole is formed on the lateral side of the outer peripheral surface of the small end of the connecting rod, and an oil receiver is formed to protrude laterally outward from the lateral side, and the lubricating oil received by the oil receiver is passed through the oil hole. The connecting portion between the piston and the small end of the connecting rod is sufficiently lubricated.

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

FIG. 1 shows a longitudinal side view of a water-cooled two-stroke engine.

In this engine E, a cylinder block part 3 in which a cylinder 2 is installed and a cylinder head part 4 are sequentially fixed to the upper part of a crankcase 1.

The cylinder 2 of the cylinder block portion 3 has a piston 5
This piston 5 is connected to a crankshaft 6 supported in the crankcase 1 by a connecting rod 7.

This is done by aligning the bearing part 10 of the large end 7a of the connecting rod 7 with the pin hole 9 of the two front and rear disc-shaped crank arms 8 fixed to the crankshaft 6. A crank pin 12 is press-fitted therein.

On the other hand, the bearing portion 1 of the small end portion 7b of the connecting rod 7
1, after aligning the bearing 14 installed here with the piston pin hole 15, the piston pin 16 is inserted into the pin hole 15.
When inserted, both ends are fixed with stop rings (not shown) to prevent them from coming out.

Both side surfaces 17 of the outer peripheral surface 17 of the small end 7b of the connecting rod 7
As shown in FIGS. 1 to 3, the oil receiver 18 is extended laterally and outwardly, and the small end 7b on the proximal side of the oil receiver 18 has an outer circumferential surface. 17 to piston pin hole 15
The two oil holes 19 are open toward the end.

A plate-shaped lubricating tool 27 is formed in the internal space of the piston 5, and the small end 7b of the connecting rod 7 is connected to the piston 5.
When connected to the screw boss 20 by the piston pin 16, the oil filling tool 27 is positioned above the oil receiver 18 provided on the side surface 17a of the outer peripheral surface 17 of the small end 7b of the connecting rod 7. It is integrally formed to protrude from the peripheral wall of the piston 5 (see FIGS. 1 and 4).

The cylinder block portion 3 is provided with an intake port 21, an exhaust port 22, and an air supply passage 23.
is formed so as to communicate the crankcase 1 and the combustion chamber 24.

A separate lubrication system is used for lubrication of this engine E, which is based on a lubricating hydraulic pump 2 driven by a crankshaft 6.
At step 5, lubricating oil is supplied from the lubricating oil tank 26 to the intake port 21, mixed with the intake air-fuel mixture, and then sucked into the crankcase 1.

The mixture containing the lubricating oil sucked in this way is used to supply lubricating oil to the sliding surfaces between the cylinder 2 and the piston 5 and to each of the bearings 10 and 11.

The lubricating oil supply operation of the engine E configured as described above will be described below.

When the crankshaft 6 rotates and the piston 5 rises, the piston 5 moves between the exhaust port 22 and the cylinder inner surface 2 of the air supply path 23.
The air-fuel mixture injected into the combustion chamber 24 from the air supply path 23 is compressed by sequentially closing the openings 22a and 23a of the piston 5 above the piston 5, resulting in a compression process.

At the same time, the space below the piston 5 is in an intake stroke while the piston 5 moves from the bottom dead center to the top dead center.

That is, as the piston 5 rises, the inside of the crankcase 1 gradually becomes negative pressure, and the cylinder inner surface 2a of the intake port 21
When the opening 21a is opened by the rise of the piston 5, the air-fuel mixture containing lubricating oil flows into the cylinder inner surface 2 of the intake port 21.
It is forcefully sucked into the space below the piston 5 from the opening 1a.

In this way, the intake air containing lubricating oil sucked into the space below the piston 5 is absorbed into the peripheral wall forming the space below the piston 5,
The bearings 10 and 11 of the crankshaft 6 and the connecting rod 7, and the connecting rod 7 and the piston 5 come into contact with each other, and lubricating oil adheres thereto for lubrication.

Then, the piston pin 16 is attached to the screw boss 20 of the piston 5.
The small end 7b of the connecting rod 7 connected with the small end 7b is attached to the upper part of the outer circumferential surface 17' of the small end 7b, and the lubricating oil that is about to flow down the outer circumferential surface 17 is received by the oil receiver 18 and flows into the oil passage hole 19. The small end 7b of the connecting rod 7, which is guided and becomes hot, is lubricated.

In addition, the lubricating oil that has adhered to the inner surface of the piston 5 and is about to flow down is poured into the oil receiver 18 provided at the small end 7b of the connecting rod 7 by the oil pouring tool 27, so that the lubricating oil that is about to flow down is The portion 7b is strongly lubricated.

5 and 6 show another embodiment, in which oil passage holes are provided above and below an oil receiver 18 provided on a side surface 17a of an outer peripheral surface 17 of a small end 7b of a connecting rod 7. 19, the lower oil passage hole 19 is for supplying the lubricating oil adhering to the lower surface 18a of the oil receiver 18 to the piston pin 16.

Moreover, what is shown in FIG. 7 and FIG. 8 shows yet another embodiment, which is a so-called floating type piston pin 16 in which the piston pin hole 15 of the piston 5 and the piston pin 16 can be relatively rotated. An example in which the present invention is implemented is also shown in the figure, in which the oil receiver 18 is integrally formed laterally outward from the screw boss 20, and oil passage holes 19 are provided in the upper and lower screw bosses 20 of the oil receiver 18. .

Note that the oil receiver 18 and the oil receiver 18 into which lubricating oil is injected while being guided by the oil receiver 18 are installed at the small end 7 of the connecting rod 7.
It is not limited to just the lateral side surface of the outer circumferential surface 17 of b, but may be in the vicinity thereof.

Since the present invention is constructed and operates as described above, it has the following effects.

(a) The oil receiver installed at the small end of the connecting rod moves up and down as the piston moves up and down, and the receiver stops the lubricating oil that is scattered in the space where the piston moves up and down and pours it into the oil passage hole. A large amount of lubricating oil can be supplied to the connecting portion with the small end of the connecting rod to provide sufficient lubrication, thereby preventing wear and seizure and greatly improving durability.

(b) Furthermore, since the oil-based tool is made to protrude above the oil receiver from the inner circumferential wall of the screw 5, and the protruding end of the oil-based tool is positioned closer to the center than the outer end of the oil receiver, the inner surface of the piston The oil-based tool also catches lubricating oil adhering to the peripheral wall and pours it into the oil passage hole.

Therefore, more lubricating oil can be supplied to the connecting portion between the piston and the small end of the connecting rod, and durability can be further improved.

(c) Furthermore, the structure is simple, as the oil fitting and the oil passage hole are provided at the small end of the connecting rod, and the oil fitting is provided on the inner circumferential wall of the piston, and can be implemented at low cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view of a vertical water-cooled two-stroke engine, Fig. 2 is a partially longitudinal front view of the main parts, Fig. 3 is a side view of the main parts,
Fig. 4 is a cross-sectional view taken along the line IV-IV in Fig. 1, Fig. 5 and Fig. 6 show another embodiment, Fig. 5 is a partial longitudinal sectional front view of the main part, and Fig. 6 is a side view of the main part. , FIG. 7 and FIG. 8 show still another embodiment, and FIG. 7 is a diagram corresponding to FIG. 4, and FIG. 8 is a diagram corresponding to FIG.
(2) Line sectional view, FIG. 9 is a longitudinal sectional front view of a device devised prior to the present invention. E...Engine, 5...Piston, 7
...Conrod, 7b...Small end of 7, 16...Piston pin, 17...7
outer peripheral surface of b, 17a... lateral side of 17, 18.
...Oil receiver, 19...Oil hole, 20...
...Pin Boss.

Claims (1)

[Scope of utility model registration request] Connecting rod 7 to screw boss 20 of piston 5 of engine E
The small end 7b of the small end 7b is connected with the piston pin 16.
An oil passage hole 1 is provided in the vicinity of the side surface 17a of the outer peripheral surface 17 of the
9, the oil receiver 18 for guiding the lubricating oil into the oil passage hole 19 projects laterally outward from the side surface of the small end, and the oil filler 27 is inserted from the inner circumferential wall of the piston above the oil receiver 18. A lubricating device between a piston and a connecting rod small end of an engine, characterized in that the projecting end of the oil filler 27 is located closer to the center than the outer end of the oil receiver 18.