Internal combustion engine with improved lubrication system

Patent metadata

Field	Value
Publication number	US-10502103-B2
Application number	US-201715825596-A
Country	US
Kind code	B2
Filing date	Nov 29, 2017
Priority date	Dec 9, 2016
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

An internal combustion engine having an internal space including a crankcase chamber includes an oil tank, a first passage communicating a lower part of the internal space with a gas phase part of the oil tank, a first check valve provided in the first passage to permit a flow from the internal space to the oil tank, a second passage communicating the gas phase part with the internal space, a second check valve provided in the second passage to permit a flow from the second passage to the internal space, a third passage communicating a liquid phase part of the oil tank with the second passage, a third check valve provided in the third passage to permit a flow from the oil tank to the second passage, and a flow regulator valve provided in the third passage for regulating a flow of lubricating oil flowing through the third passage.

First claim

The invention claimed is:

1. An internal combustion engine, wherein a pressure in an internal space including a crankcase chamber thereof pulsates owing to a reciprocating movement of a piston in a cylinder, the internal combustion engine comprising:
an oil tank separated from the internal space and configured to store lubricating oil therein;
a first passage communicating a vertically lower part of the internal space with a gas phase part of the oil tank;
a first check valve provided in the first passage to permit a flow from the internal space to the oil tank but not in a reverse direction;
a second passage connected with the gas phase part of the oil tank;
an intake passage connecting the internal space with the second passage;
a second check valve provided in the intake passage to permit a flow from the second passage to the internal space but not in a reverse direction;
a third passage communicating a liquid phase part of the oil tank with the second passage;
a third check valve provided in the third passage to permit a flow from the oil tank to the second passage but not in a reverse direction; and
a flow regulator valve provided in a part of the third passage located between the third check valve and the second passage for regulating a flow of lubricating oil flowing through the third passage.

2. The internal combustion engine according to claim 1 , further comprising:
a valve actuation chamber accommodating a valve actuation mechanism for actuating an exhaust valve provided in an exhaust passage communicating with the cylinder;
a fourth passage communicating a vertically lower part of the internal space with the valve actuation chamber;
a fourth check valve provided in the fourth passage to permit a flow from the internal space to the valve actuation chamber but not in a reverse direction;
a fifth passage communicating the valve actuating chamber with the internal space or the oil tank; and
a fifth check valve provided in the fifth passage to permit a flow from the fifth passage to the internal space or the oil tank but not in a reverse direction.

3. The internal combustion engine according to claim 2 , wherein a connecting part between the fourth passage and the internal space is positioned lower than a connecting part between the first passage and the internal space.

4. The internal combustion engine according to claim 3 ,
wherein the internal combustion engine consists of a two stroke engine, and is provided with a scavenging passage selectively communicating the internal space with a side part of the cylinder depending on a position of the piston; and
wherein the second passage and the fifth passage are connected to the internal space via the intake passage, and the second check valve and the fifth check valve consist of a common check valve provided in the intake passage.

5. The internal combustion engine according to claim 4 , further comprising a throttle valve provided upstream of a part of the intake passage where the second passage and the fifth passage are connected thereto.

6. The internal combustion engine according to claim 4 , further comprising:
a crankshaft disposed in the internal space and rotatably supported by a main body of the internal combustion engine;
a sixth passage formed in the main body and extending to a sliding part of the crankshaft;
a seventh passage communicating the sixth passage with the fifth passage or with a part of the second passage located between the internal space and a connecting part between the second passage and the third passage; and
a sixth check valve provided in the seventh passage to permit a flow to the sixth passage but not in a reverse direction.

7. The internal combustion engine according to claim 4 , further comprising a fuel injection valve for injecting fuel into the scavenging passage.

8. The internal combustion engine according to claim 1 , wherein the engine consists of a horizontal engine having a cylinder axial line oriented in a substantially horizontal direction.

Assignees

• Honda Motor Co Ltd

Inventors

• Kurata Mashu

Classifications

• F01M9/06

  Dip or splash lubrication · CPC title

• F01M1/04 Primary

  using pressure in working cylinder or crankcase to operate lubricant feeding devices · CPC title

• F01M1/16

  Controlling lubricant pressure or quantity (rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22) · CPC title

• F01M3/00

  Lubrication specially adapted for engines with crankcase compression of fuel-air mixture or for other engines in which lubricant is contained in fuel, combustion air, or fuel-air mixture (separating lubricant from air or fuel-air mixture before entry into cylinder F01M11/08) · CPC title

• F01M11/02

  Arrangements of lubricant conduits · CPC title