JP2577278B2 - Lubrication system in rocker arm chamber for oil-cooled overhead valve engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lubricating device in a rocker arm chamber in an oil-cooled overhead valve engine.

[Prior Art] The cylinder block / cylinder head of an engine receives heat from the combustion chamber directly, and therefore needs to be strongly cooled.

For this reason, some conventional engines are provided with an oil cooling device having a high cooling performance. In general, oil is configured to be circulated and returned to an oil pan by a circulation pump through an oil cooling jacket, an oil cooler, a return pipe, and a crank chamber in this order.

By the way, among the engines equipped with the oil cooling device, the overhead valve engine requires a lubrication device for lubricating the inside of the rocker arm chamber in addition to the oil cooling device, which is a separate system from the oil cooling device. In most cases, the following problems occur because the oil pressure feeding and supply type is provided.

[Problems to be Solved by the Invention] That is, in the above-described conventional technology, since oil passages for both the oil cooling device and the lubrication device are required, a large number of oil passages must be formed in the engine. It gets messy.

An object of the present invention is to simplify an oil passage of an engine.

[Means for Solving the Problems] According to the present invention, as shown in FIG. 1, an oil cooling jacket 4 is formed on at least one of a cylinder block 2 and a cylinder head 3 of an engine 1, 6
In the oil-cooled overhead valve engine, the circulation pump 7 sequentially passes through the oil cooling jacket 4, the oil cooler 8, the return pipe 9, and the crank chamber 10 and returns to the oil pan 5 in the following manner. It is characterized by.

That is, an oil distribution chamber 13 is formed in the bottom wall portion 12 of the push rod chamber 11, and the end portion 14 of the return pipe 9 is connected to the oil distribution chamber 13, and the oil distribution chamber 13 is cranked by an oil return hole 15. While communicating with the chamber 10, the oil blow-up hole 16 communicates with the push rod chamber 11, and the oil return hole 15 and the oil blow-up hole 16 have inner diameters of the blow-by gas 17 in the crank chamber 10 passing through both holes 15 and 16. It is characterized in that it is formed in such a size that it can flow to the rocker arm chamber 18 via the push rod chamber 11.

[Operation] As shown in FIG. 1, the oil 6 absorbed by the oil cooling jacket 4 radiates heat in the oil cooler 8, then flows from the return pipe 9 into the oil distribution chamber 13, from which the oil return hole 15, the crank It passes through the chamber 10 in order and returns to the oil pan 5. At this time, a part of the oil 6 passing through the oil return hole 15 is entrained in the blow-by gas 17 flowing from the crank chamber 10 and becomes an oil mist 19 together with the blow-by gas 17 from the oil blowing hole 16 to the push rod chamber 11. Is blown up. The oil mist 19 rises in the push rod chamber 11 with the blow-by gas 17 and reaches the rocker arm chamber 18 to lubricate it.

[Effects] The present invention has the following effects.

That is, a part of the oil flowing through the oil cooling device becomes an oil mist due to the blow-by gas, passes through the push rod chamber with the blow-by gas, reaches the rocker arm chamber, and lubricates the oil. This eliminates the need for a dedicated oil passage for lubricating the rocker arm chamber,
The engine can be easily manufactured.

Example An example of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a two-cylinder diesel engine, which is constructed by assembling a cylinder head 3 on an upper side of a cylinder block 2 and an oil pan 5 on a lower side. As shown in FIG. 2, cylinders 20 and 21 are formed in the cylinder block 2 side by side.

This engine is provided with an air cooling device and a liquid cooling device.

 The air cooling device is as follows.

As shown in FIG. 2, a cooling fan 22 is mounted on the front side of the cylinder block 2 and is covered with a fan case 23. A wind guide cover 25 is attached along the left lateral wall 24 of the cylinder block 2, and the cylinder block 2 is
A long left cooling air passage 26 is formed before and after along the left lateral wall 24 of FIG. A long push rod chamber 11 is provided at a position facing the right lateral wall 27 of the cylinder block 2, and a right cooling air passage 29 is formed between the right lateral wall 27 of the cylinder block 2 and the chamber wall 28 of the push rod chamber 11. ing.

 The oil cooling device is as follows.

As shown in FIG. 2, a rear oil cooling jacket 31 formed on a rear wall 30 of the cylinder block 2 and a liquid cooling jacket 33 between cylinders formed on an inter-cylinder wall 32 are combined with a cylinder head 3.
Are communicated with each other by a communication passage 34 formed on the lower surface of. As shown in FIG. 1, an oil inlet 35 formed at the lower part of the rear liquid cooling jacket 31 is provided with an oil overflow port 38 of a primary relief valve 37 in the middle of a lubricating oil supply passage 36 and an oil through a circulation pump 7 in that order. It communicates with the inside of the bread 5. The oil outlet 39 formed at the upper part of the inter-cylinder oil cooling jacket 33 is connected to the oil pan 5 through the head jacket 40, the oil cooler 8, the return pipe 9, the valve chamber 43, the oil return hole 15, and the crank chamber 10 in this order.
Is communicated to.

In this oil cooling device, as shown by an arrow in FIG. 1, one of the oil 6 supplied to a sliding portion 41 such as a bearing metal of a crankshaft through a lubricating oil supply passage 36 by a pumping force of a circulation pump 7. The part is the oil overflow port 38 of the primary relief valve 37
, Overflows the rear oil cooling jacket 31, the communication passage 34, the oil cooling jacket 33 between cylinders, the head jacket 40, the oil cooler 8, and the return pipe 9 in order, and flows into the valve chamber 43.
From here, the oil returns to the oil pan 5 through the oil return hole 15 and the crank chamber 10 in this order.

The valve chamber 43 in the valve boss 42 has a secondary relief valve
47 is accommodated therein, and communicates with an oil lead-out passage 48 led out from a lower portion of the oil cooling jacket 33 between cylinders. As a result, when the oil pressure in the oil cooling path rises abnormally, the secondary relief valve 47 opens to release the pressure, thereby preventing damage to the oil cooler 8 and oil leakage in the oil cooling path.

The engine 1 is provided with a lubricating device in the rocker arm chamber 18 using the valve chamber 43 and the like, which is as follows.

The valve chamber 43 is formed in a raised valve boss 42 on the bottom wall 12 of the push rod chamber 11, and connects the terminal end 14 of the return pipe 9. By branching the oil blow-up hole 16 and the oil return hole 15 up and down from the valve chamber 43, the valve chamber 43 has a function as the oil distribution chamber 13. The oil diverting chamber 13 communicates with the crank chamber 10 through an oil return hole 15 and a push rod chamber 11 through an oil blowing hole 16.
Is communicated to. Oil return hole 15 and oil blow-up hole 16
Is formed to have a size that allows the blow-by gas 17 in the crank chamber 10 passing through both holes 15 and 16 to flow to the rocker arm chamber 18 via the push rod chamber 11. If the inside diameter of the oil return hole 15 is too small, the flow of the oil 6 flowing down the oil return hole 15 will be slowed down by the resistance of the blow-by gas 17 going up there, and the oil 6 flowing through the oil cooling path will be slowed down.
Will hinder the smooth flow. If the inner diameter of the oil blowing hole 16 is too small, the flow velocity of the blow-by gas 17 passing therethrough decreases, and the blow-by gas 17 does not reach the rocker arm chamber 18. Incidentally, reference numeral 54 in the drawing denotes a breather chamber.

In this lubrication device, the oil return hole
A portion of the oil 6 flowing down from the crankcase 10 is caught in the blow-by gas 17 flowing from the crank chamber 10 to become an oil mist 19 and the oil blow-up hole 16 together with the blow-by gas 17.
Is blown up to the push rod chamber 11. The oil mist 19 rises in the push rod chamber 11 with the blow-by gas 17 and reaches the inside of the rocker arm chamber 18 to lubricate it.

The oil mist 19 that has lubricated the inside of the rocker arm chamber 18 aggregates here, flows down the push rod chamber 11, and accumulates on the bottom wall portion 12. As shown in FIG.
The tappet hole 44 is opened, and the oil 6 accumulated on the bottom wall portion 12 flows down from the gap between the tappet 45 and the tappet hole 44 to lubricate the tappet 45 and the valve gear cam 46.

FIGS. 4 and 5 show another example, which differs from the above embodiment in the following points.

In the above embodiment, as shown in FIG.
In this example, the end portion 14 of the return pipe 9 from the oil cooler 8 is connected to the end portion 14 of the push rod chamber 11 as shown in FIG. Connected to the top.

In the above embodiment, as shown in FIG. 1, the valve chamber 43 is provided with the function of the oil distribution chamber 13 by opening the oil return hole 15 of the oil blow-up hole 16 above and below the valve chamber 43. However, in this example, as shown in FIG. 4, only an oil inflow hole 49 communicating with the push rod chamber 11 is provided above the valve chamber 43, and the valve chamber 43 has no function as an oil distribution chamber.

In the above embodiment, as shown in FIG.
The valve chamber 43 communicates with the crank chamber 10 through the valve chamber 43. In this example, the valve chamber 43 is connected to the oil level of the oil 6 in the oil pan 5 through the final return pipe 50 as shown in FIG. It communicates below. Therefore, the blow-by gas does not flow into the valve chamber 43, and the oil 6 passing therethrough does not flow.
Has the advantage that the smooth flow of the gas is not hindered by the blow-by gas. In this example, as shown in FIG. 5, the terminal plug 52 of the final return pipe 50 is
The oil pan 5 does not need to be provided with a new connection hole.

[Brief description of the drawings]

1 to 3 are views for explaining an embodiment of the present invention.
The figure is a vertical cross-sectional front view of the engine, and FIG. 2 is II-II in FIG.
FIG. 3 is a sectional view taken along line III-III of FIG. 4 and 5 are diagrams for explaining another example, FIG. 4 is a diagram corresponding to FIG. 1, and FIG. 5 is a longitudinal sectional view of the bottom of the oil pan. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Cylinder block, 3 ... Cylinder head, 4 ... Oil cooling jacket, 5 ... Oil pan, 6 ... Oil, 7 ... Circulation pump, 8 ... Oil cooler, 9 ... Return pipe, 10 …… Crank chamber, 11 …… Push rod chamber, 12 …… 11 Bottom wall, 13 …… Oil diversion chamber,
14 ... Terminal end of 9, 15 ... Oil return hole, 16 ... Oil blow-up hole, 17 ... Blow-by gas, 18 ... Rocker arm chamber.

Claims (1)

(57) [Claims] An oil cooling jacket (4) of at least one of a cylinder block (2) and a cylinder head (3) of an engine (1) is formed. Oil (6) in an oil pan (5) is circulated by a circulation pump (7). In an oil-cooled overhead valve engine configured to sequentially return through the return pipe 9 and the crank chamber 10 and return to the oil pan 5, an oil distribution chamber 13 is formed in a bottom wall portion 12 of a push rod chamber 11. The oil distribution chamber 13 is connected to the end portion 14 of the return pipe 9. The oil distribution chamber 13 communicates with the crank chamber 10 through an oil return hole 15 and a push rod chamber through an oil blowing hole 16.
11 and the inner diameters of the oil return hole 15 and oil blow-up hole 16
A lubricating device for a rocker arm chamber in an oil-cooled overhead valve engine, the blower gas having a size that allows a blow-by gas 17 in a crank chamber 10 passing through 16 to flow through a push rod chamber 11 to a rocker arm chamber 18.