JPS6024893Y2 - Internal combustion engine valve arm lubrication device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a lubricating device for a valve arm in an internal combustion engine.

Generally, in an internal combustion engine, a pump that supplies lubricating oil to a valve arm is located above an oil tank.

Therefore, when the engine stops operating, most of the lubricating oil in the valve arm lubrication system flows back into the oil tank.

As a result, it becomes difficult for the pump to take in oil when the engine is started, and this causes the problem of seizures due to lack of oil in the sliding parts of the intake and exhaust valves and the valve arms.

As a countermeasure to this problem, a system in which a check valve is provided in the valve arm lubrication system has been proposed, but this has the disadvantage of being unreliable due to malfunction due to dust being caught in the check valve.

As a lubricating device that solved these drawbacks,
-102031 has been proposed.

This is in a turbocharged engine in which the lubricant oil discharge port provided in the engine body and the lubricant oil inlet port provided in the turbocharger are connected via an oil pipe that bypasses the part higher than the discharge port and inlet. A downward bend is made in a part of this oil pipe so that lubricating oil accumulates there when the engine is stopped.

However, with this device, oil accumulates in the bends for a short time immediately after the engine stops, but if the engine is stopped for a long time, oil accumulates in the bends due to the so-called siphon phenomenon. The disadvantage is that the oil that accumulates in the oil pan is returned to the oil pan.

The present invention is an attempt to address the above-mentioned inconveniences and shortcomings of the conventional art, and the present invention provides a valve arm lubricating device for an internal combustion engine in which a pump is located above the oil tank. Raise the middle of the suction pipe that communicates with the pump suction port to a higher position than the pump, and create a cross-sectional area that allows sufficient air to flow even if there is oil in the middle of the suction pipe up to the highest point of the suction pipe. In other words, an anti-siphon pipe with a cross-sectional area larger than the cross-sectional area of the communication pipe between the pump and the anti-siphon pipe is inserted to prevent oil from flowing back into the oil tank due to the siphon phenomenon when the engine is stopped. This is a feature.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an oil tank, and a pump 2 for supplying lubricating oil to the valve arm is disposed above the oil tank 1.

Reference numeral 3 denotes a suction port of the pump 2, and a suction pipe 5 is provided between the inlet port 3 and an outlet pipe 4 of the oil tank 1.

This suction pipe 5 has a curved shape so that a part thereof is located at a higher position than the pump 2, and its highest point 6
An anti-siphon pipe 7 is interposed between the pump and the pump suction port 3.

The inner diameter of the siphon prevention pipe 7 is such that when the engine operation is stopped, the oil filled in the lubrication system gradually returns to the oil tank due to the position head and siphon phenomenon. The dimensions are selected to have a cross-sectional area that allows the air sucked into the anti-siphon pipe to flow sufficiently even if oil is present in the anti-siphon pipe.

(Because oil and air intersect, the cross-sectional area of the anti-siphon tube is affected by the viscosity of the oil; larger clays require larger diameter anti-siphon tubes).

Reference numeral 8 is a connecting pipe that connects the siphon prevention pipe 7 and the pump suction port 3, and 9 is a discharge pipe of the pump, the tip of which extends to the valve arm of the engine.

10 is a filter for the take-out pipe, and 11 is an air vent.

In operation, when the engine is stopped, the suction pipe 5
The oil located between the highest point 6 of
Reflux into the oil tank.

At this time, the air sucked into the system also mixes with the oil and flows into the siphon prevention pipe 7 (the reference numeral 12 in FIG.
However, the siphon prevention pipe 7
Since the inner diameter of the pipe has a cross-sectional area that allows sufficient air to flow even if there is oil in the pipe, the air flowing into the anti-siphon pipe 7 quickly rises to the upper part of the iron pipe.

Then, air flows into the siphon prevention pipe 7 according to the amount of oil in the suction pipe 5 that returns to the oil tank 1, so this air gradually fills the inside of the suction pipe 5, and the siphon phenomenon will eventually stop. .

At this time, the siphon prevention pipe 7, the connecting pipe 8, and the pump 2
There will be enough oil left inside.

As mentioned above, in this invention, the suction pipe that connects the pump suction port and the oil tank outlet pipe is provided with a point in the middle that is higher than the pump, so that when the engine is stopped, oil flows from the pump side. In addition to ensuring that the reflux is caused by a siphon phenomenon, a siphon prevention pipe is installed on the pump side to prevent oil reflux due to the siphon phenomenon, allowing the entire amount of oil in the lubrication system to flow back into the oil pump when engine operation is stopped. It is possible to prevent such a situation from occurring.

Since the function operates completely and reliably, the reliability of the valve arm lubrication system is extremely high.

As described above, according to the present invention, a highly reliable device can be used as a lubricating device for the valve arm, and the practicality of the present invention is extremely large.

[Brief explanation of the drawing]

The figures show a lubricating device according to the present invention, with FIG. 1 being an overall side sectional view and FIG. 2 being an enlarged side sectional view of the main part. 1...Oil tank, 2...Pump, 3.
...Suction port, 4...Outlet pipe, 5...
...Suction pipe, 6...Highest point, 7...
・Siphon prevention pipe, 8...Connection pipe, 13...
...Air (bubbles), 13...Oil.

Claims (1)

[Scope of utility model registration request] In a valve arm lubrication system for an internal combustion engine in which the pump is located above the oil tank, the suction pipe that connects the oil tank outlet pipe and the pump suction port has a part of it located at a position higher than the pump. A siphon prevention pipe is interposed between the highest point of the curve and the pump suction port, and has a cross-sectional area larger than the cross-sectional area of the connecting pipe between the pump and the siphon prevention pipe. Valve arm lubrication device for internal combustion engines.