JPS606580Y2 - Internal combustion engine lubricating oil control device - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a lubricating device for supplying oil under pressure to a valve mechanism in a rocker cover in an internal combustion engine, and returning the oil from the rocker cover by a natural fall method. This invention relates to a lubricating oil control device that prevents oil from blowing during high-speed operation.

[Prior Art] In an internal combustion engine, a blow-by gas reduction device is provided from the crank chamber through the rocker cover to the air cleaner side.
Some lubricating devices for the valve mechanism inside the rocker cover are configured to forcefully feed oil to the valve mechanism, and then return the oil to the oil pan at the bottom of the crankcase by gravity through an oil return passage.

[Problem that the invention attempts to solve]

According to this, oil blowing may occur during high-speed operation.

The reason for this is that the amount of oil discharged from the oil pump increases in proportion to the rotation speed, but there is a limit to the amount of oil returned through the oil return passage, so the amount of oil pumped to the valve mechanism during high-speed operation is less than the amount returned. This is because oil accumulates inside the rocker cover and is blown out from the blow-by gas outlet.

Regarding this point, it may be possible to provide an oil amount regulating valve as shown in Japanese Patent Application Laid-Open No. 51-734, but in this case, an oil relief passage becomes essential and the structure becomes complicated.

[Means to solve the problem]

The present invention was developed in view of these circumstances. An oil volume adjustment valve is provided in the middle of the oil supply passage from the crankcase side to the rocker cover internal valve mechanism, and this oil volume adjustment valve allows oil to be fed under pressure to the valve mechanism. When the oil pressure exceeds the set oil pressure during high-speed operation, the oil passage is throttled to reduce the rate of increase in oil amount, and the amount of oil pumped is controlled to the amount required for lubrication and cooling, and the rocker cover is closed. To provide a lubricating oil control device for an internal combustion engine that prevents oil from accumulating in the internal combustion engine.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

In Fig. 1, an example of an internal combustion engine to which the present invention is applied will be described. Reference numeral 1 indicates a crankcase, and an oil pan 2 is attached to the bottom of the crankcase 1, and lubricating oil is supplied to the bottom of the crankcase 1. This oil is pumped up by an oil pump (not shown) and supplied to the journal portion of the crankshaft 4 through the oil passage 3.

Further, the oil in the oil passage 3 passes through oil supply passages 8 and 16 provided in communication with the crankcase 1 and the cylinder head 5 thereon, and then passes through the passage of the camshaft 9 in the valve mechanism 8 in the rocker cover 7. 10, and is supplied to the journal portion of the camshaft 9, the cam surface of the cam 11, the sliding surface of the rocker arm 12, etc. to lubricate and cool each part.

The inside of the rocker cover 7 communicates with the oil pan 2 through an oil return passage 13 that is formed in communication with the crankcase 1 and the cylinder head 5, and lubricates and cools the valve mechanism 8. The oil flowing down is returned to the oil pan 2 by falling under its own weight through an oil return passage 13.

On the other hand, in contrast to such a lubricating device, the blow-by gas return device is such that the crank chamber 14 in the lower part of the crank case 1 communicates with the inside of the rocker cover 7 through the blow-by gas passage 15, and is attached to the upper part of the rocker cover 7. An oil separator 17 that separates oil and gas is connected to an air cleaner 19 via a blow-by gas hose 18 so as to guide only the blow-by gas.

Therefore, according to the present invention, in the above-mentioned lubricating device, a passage 6 for pressure-feeding oil from the crankcase 1 side to the valve mechanism 8 is provided.
, 16 is provided with an oil amount adjusting valve 20.

As detailed in FIG. 2, this oil amount adjusting valve 20 has a large diameter valve chamber 21 formed in a stepped manner in a passage 6 on the crankcase side, and a valve body 22 is disposed within this valve chamber 21. It is inserted into the stepped portion 21a of the chamber 21 so as to be moved forward toward the cylinder head 5 against the return spring 23 from a retracted position.

The valve body 22 has a large diameter pressure receiver that fits into the valve chamber 21.
A small-diameter valve stem 22b projects from the center of the valve stem 2a, and an oil passage 22c is formed in a T-shape within the valve stem 22b.

Further, the tip of the valve stem portion 22b has a pointed valve portion 22d, and a throttle passage 22e communicating with the oil passage 22c is bored in the valve portion 22d, and a cylinder head side passage 16 facing the valve portion 22d. A valve port 24 is formed to be opened and closed by a valve portion 22d.

Since the present invention is constructed in this manner, blow-by gas leaking from the cylinder of the crank case 1 into the crank chamber 14 during engine operation enters the rocker cover through the blow-by gas passage 15, where the oil is separated by the oil separator 17. is separated and removed, and only the blow-by gas is sucked into the air cleaner 19 via the blow-by gas hose 18 and is used for combustion again.

Also, the oil at the bottom of the oil pan 2 is pumped by the oil pan 2, and is supplied to the journal portion of the crankshaft 4 through the passage 3 for lubrication, and at the same time is supplied to the valve mechanism 8 through the passage 6. Ru.

By the way, the oil flowing through the passage 6 enters the valve chamber 21 of the oil amount adjustment valve 20, and its pressure is applied to the pressure receiving part 22a of the valve body 22, so that the oil pressure is low during low and medium speed operation. In this case, the valve body 22 is moved to a retracted position by the spring 23 as shown in FIG.

Therefore, the valve portion 22d at the tip of the valve stem moves away from the valve port 24 to open the valve port 24, thereby opening the oil passage 22.
c communicates with the passage 16 via the valve chamber 21 and the valve port 24,
The oil in the passage 6 flows through these threads into the passage 16 without being controlled in oil quantity, and is supplied to the valve mechanism 8 to lubricate each part.

The oil after lubricating the valve mechanism 8 is returned to the oil pan 2 from the rocker cover 7 via the oil return passage 13.

On the other hand, when the discharge pressure increases with the oil discharge amount of the oil pump during high-speed operation, the valve body 22
Since the oil pressure acting on the pressure receiver section 22a also increases, the valve body 22 moves against the spring 23 as shown in FIG. 3, and the valve section 22d closes the valve port 24.

Therefore, the oil passage 22c comes to communicate with the passage 16 only through the throttle passage 22e, and the oil in the passage 6 is throttled by the throttle passage 22e, reducing the flow rate.
As a result, the amount of oil supplied to the valve train 8 from the passage 16 decreases at a rate of increase as shown by the solid line versus the broken line in FIG.

In this way, the amount of oil supplied to the valve mechanism 8 is regulated to the amount necessary for lubrication and cooling during high-speed operation, so that no excess oil flows into the rocker cover 7, and the valve mechanism 8 is prevented from flowing into the rocker cover 7. All of the oil after lubrication does not accumulate in the rocker cover 7 (it is sequentially returned via the oil return passage 13).

Therefore, oil overflowing into the rocker cover 7 and flowing from the oil separator 17 to the air cleaner 19 side, which is an oil blowout, is completely eliminated.

[Effect of idea]

As described above, according to the present invention, when the oil discharge amount and discharge pressure of the oil pump increase during high-speed operation, the oil pressure is detected by the oil amount adjustment valve 20 and the amount of oil pumped to the valve mechanism 8 is adjusted. Since oil is prevented from accumulating inside the rocker cover 7, oil blowing is completely prevented.

The oil amount adjusting valve 20 is configured to detect oil pressure and automatically open/close the valve, and requires no additional parts, so it is structurally simple.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the device according to the present invention, FIG. 2 is a cross-sectional view showing the main part of the oil amount adjusting valve, and FIG. 3 is a cross-sectional view showing the operating state of the oil amount adjusting valve. FIG. 4 is a diagram showing the relationship between the amount of oil pumped to the valve mechanism and the engine speed. 1...Crankcase, 6,16...
Oil supply passage, 7...Rocker cover, 8
...Valve train mechanism, 20... Oil amount adjustment valve.

Claims (1)

[Scope of utility model registration request] An oil volume adjustment valve is provided in the middle of the oil supply passage from the crankcase side to the rocker cover internal valve mechanism, and the oil volume adjustment valve is configured to control the oil flow when the oil supplied to the valve mechanism exceeds the set oil pressure during high-speed operation. A lubricating oil control device for an internal combustion engine, characterized in that the lubricating oil control device for an internal combustion engine is configured to reduce the rate of increase in oil amount by narrowing the passage.