JPS609364Y2 - engine lubrication system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lubricating device for an engine, and more particularly to a lubricating device for reducing noise in a valve train.

Generally, oil that cools and lubricates the inside of an engine is pumped by an oil pump and supplied to each sliding part of the crankshaft, cylinder, and piston, and passes through a lubricating oil supply passage provided around the cylinder to the cylinder head. (Refer to Japanese Utility Model Publication No. 54-45465).

However, in the above-mentioned conventional lubricating device, since the lubricating oil supply passage that supplies oil to the cylinder head is provided around the cylinder, the oil passing through the lubricating oil supply passage absorbs the combustion heat of the air-fuel mixture and is relatively It becomes high temperature and is sent to the above-mentioned valve train system.

As a result, the viscosity of the oil decreases, and the damper effect that utilizes the viscosity of the oil at each contact portion of the valve train is reduced, resulting in a problem that the noise generated when the contact portions collide becomes louder.

Therefore, a method can be considered to cool the oil pumped by the oil pump using a cooling device such as an oil cooler to increase the viscosity of the oil before sending it to each lubrication system. Even if the noise can be reduced, it also increases the viscosity of the oil that lubricates the crankshaft, cylinder, and piston, which increases sliding resistance and has a negative effect on fuel efficiency.

Therefore, in order to eliminate such drawbacks, the present invention aims to replace the lubricating oil supply passage downstream of the oil pump with a main lubricating oil supply passage for supplying oil to the crankshaft, cylinder, and piston, and a cam provided in the cylinder head. It branches into a cylinder head lubricant supply passage for supplying oil to the valve train system such as shafts and valves, and a portion of the cylinder head lubricant supply passage is arranged along the outer wall surface of the engine behind the cooling fan. By doing so, it is possible to reliably reduce the collision noise of each contact part of the valve train without increasing the sliding resistance of each sliding part of the crankshaft, cylinder, and piston.

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

In the figure, 1 is a cylinder block, 2 is a cylinder head, a cylinder 3 is formed in the cylinder block 1, and a piston 4 that reciprocates within the cylinder 3 is supported by a crankshaft 6 via a connecting rod 5. On the other hand, the cylinder head 2 includes intake and exhaust valves (not shown).

), the camshaft 7 for opening and closing the rocker arm (
Not shown.

) etc. are provided.

A flywheel 8 is supported at the rear end of the crankshaft 6, and a pulley 9 is supported at the front end of the crankshaft 6.
The basic structure is a vertical engine that drives a cooling fan 11 supported in front of the engine.

On the other hand, an oil pan 1 is provided at the bottom of the cylinder block 1.
2 is installed, the oil 13 in the oil pan 12 is sucked from the oil straight 15 by the oil pump 14,
The lubricating oil is supplied under pressure to the lubricating oil supply passage 16.

The lubricating oil supply passage 16 is located downstream of the oil pump 14, and includes a main lubricating oil supply passage 16a that supplies oil to the crankshaft 6, cylinder 3, and piston 4, and a cylinder head lubricating oil that supplies oil to the valve train of the cylinder head 2. A part of the cylinder head lubricant supply passage 16b is arranged along the outer wall surface of the engine behind the cooling fan 11, that is, the outer wall surface of the front cover 17, and the cylinder head lubricant supply passage 16b branches into a supply passage 16b. When the supplied oil passes through the front cover 17, it is cooled by the cooling air from the cooling fan 11. More preferably, the front cover 17 is made of heat conductive material such as aluminum in order to enhance the cooling effect of the cooling air. It is made of a material with excellent properties, and has cooling fins 18 on its outer wall.
will be provided.

Therefore, in the above embodiment, the cylinder head lubricating oil supply passage 1 is separate from the main lubricating oil supply passage 16a that supplies oil to the crankshaft 6, cylinder 3, and piston 4.
Since the viscosity of the oil can be increased by cooling only 6b, the damper effect obtained by the viscosity of the oil can be used without increasing the sliding resistance of each sliding part of the crankshaft 6, cylinder 3, and piston 4. It is possible to reliably reduce the noise of the valve train, and it has a simple structure in which a part of the cylinder head lubricating oil supply passage 16b is provided along the outer wall surface of the engine without using a special cooling device. It is easy to mass produce and has great practical advantages.

In the above embodiment, a vertical engine was described, but in the case of a horizontal engine in which the cooling fan is placed on the side of the engine, the cylinder head lubricating oil supply passage is placed along the side wall surface of the cylinder block behind the cooling fan. In order to enhance the cooling effect, it is preferable that the cylinder block is made of a material with excellent thermal conductivity such as aluminum.

As explained above, according to the engine lubrication system of the present invention, the lubricating oil supply passage downstream of the oil pump is connected to the crankshaft,
It branches into a main lubricating oil supply passage that supplies oil to the cylinders and pistons and a cylinder head lubricating oil supply passage that supplies oil to the valve train, and a part of the cylinder head lubricating oil supply passage is connected to the engine behind the cooling fan. Since it is provided along the outer wall surface, the noise of the valve train can be reliably reduced without increasing the sliding resistance of each sliding part of the crankshaft, cylinder, and piston.

[Brief explanation of drawings]

The figure is an overall schematic diagram showing an embodiment of the present invention. 1...Cylinder block, 2...Cylinder head, 3...Cylinder, 4...
Piston, 6...Crankshaft, 7...
Camshaft, 11...Cooling fan, 12...
...Oil pan, 14...Oil pump,
16... Lubricating oil supply passage, 16a...
Main lubricating oil supply passage, 16b... Cylinder head lubricating oil supply passage, 17... Front cover.

Claims (1)

[Scope of utility model registration request] In an engine lubricating system in which oil from an oil pan is pumped by an oil pump to each lubrication system through a lubricating oil supply passage provided in the engine, the lubricating oil supply passage downstream of the oil pump is connected to the crankshaft, cylinder, etc. The cylinder head lubricant supply passage branches into a main lubricant supply passage for supplying oil to the piston and a cylinder head lubricant supply passage for supplying oil to the valve train built into the cylinder head. An engine lubricating device characterized in that a part of the engine lubrication device is arranged along the outer wall surface of the engine behind the cooling fan.