Valve train lubricating structure in internal combustion engine

• US 20050199202A1
• Filed: 03/02/2005
• Published: 09/15/2005
• Est. Priority Date: 03/10/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Hoi, Yosuke
• Granted Patent: US 7,290,514 B2
• Time in Patent Office: Days
• US Class Current: 123/90.33
• CPC Class Codes: F01M 1/06 Lubricating systems characterised by the provision therein of crankshafts or connecting rods with lubricant passageways, e.g. bores crankshafts, connecting-rods, per se F16C
• CPC Class Codes: F01M 1/16 Controlling lubricant pressure or quantity rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22
• CPC Class Codes: F01M 2001/126 Dry-sumps
• CPC Class Codes: F01M 2250/64 Number of revolutions
• CPC Class Codes: F01M 9/10 Lubrication of valve gear or auxiliaries

Abstract

To prevent a drop in a lubricating oil supply pressure in a valve train from occurring by disposing a lubricating oil supply path for the exclusive use of the valve train without allowing the lubricating oil to flow through an oil gallery, thereby securing a sufficient amount of supply of the lubricating oil in the valve train to enhance lubrication efficiency. A feed pump rotating with a crankshaft is disposed at a leftward end of the crankshaft. Lubricating oil supplied from the feed pump flows through an oil cooler and an oil filter. Part of the lubricating oil is supplied through a lubricating oil supply path to an oil gallery and to journals, crankpins, and the like of the crankshaft. The other part of the lubricating oil is supplied through lubricating oil supply paths for the exclusive use of the valve train.

Claims

1. A valve train lubricating structure in an internal combustion engine, comprising:

an oil pump rotated by being operatively connected with a rotation from a crankshaft;

a supply path for providing a route, through which a lubricating oil delivered from the oil pump is supplied to an oil gallery; and

a plurality of branch supply paths for providing routes, through which the lubricating oil is supplied to different parts of the internal combustion engine, one of the plurality of branch supply paths forming a supply path of the lubricating oil to the valve train;

wherein the supply path of the lubricating oil to the oil gallery includes a check valve and the supply path going to the valve train is branched off at a point upstream of the check valve.

2. The valve train lubricating structure in an internal combustion engine according to claim 1, wherein said oil pump is a supply feed pump for supplying lubricating oil and further including a return oil pump operatively mounted relative to said crankshaft for returning oil accumulated in a crankcase to a sump oil tank.

3. The valve train lubricating structure in an internal combustion engine according to claim 2, wherein the supply feed pump is operatively connected to the sump oil tank and further including an oil cooler and oil filter operatively connected to said supply feed pump for supplying lubricating oil from the sump oil tank to the oil cooler and oil filter.

4. The valve train lubricating structure in an internal combustion engine according to claim 3, and further including a sump oil supply path for connecting the sump oil tank and the supply feed pump and a relief valve operatively positioned relative to said sump oil supply path and said supply feed pump for regulating lubricating oil supply pressure in the supply path.

5. The valve train lubricating structure in an internal combustion engine according to claim 1, wherein the check valve in the supply path for the lubricating oil supplied to the oil gallery is automatically controlled in response to a supply pressure of the lubricating oil.

6. The valve train lubricating structure in an internal combustion engine according to claim 5, wherein said check valve suppresses a supply of lubricating oil when the engine is operated at a low speed for increasing the flow of lubricating oil to the valve train.

7. The valve train lubricating structure in an internal combustion engine according to claim 5, wherein said check valve increases a supply of lubricating oil when the engine is operated at a high speed for decreasing the flow of lubricating oil to the valve train.

8. The valve train lubricating structure in an internal combustion engine according to claim 1, wherein the supply path of the lubricating oil to the valve train includes a plurality of apertures for supplying lubricating oil to cam surfaces of the valve train.

9. The valve train lubricating structure in an internal combustion engine according to claim 1, wherein said supply path of the lubricating oil to the valve train includes a substantially horizontal section passing through a joint in a crankcase and a substantially vertical section for supplying lubricating oil to the valve train.

10. The valve train lubricating structure in an internal combustion engine according to claim 9, wherein said substantially vertical section of the supply path of the lubricating oil to the valve train includes two branches for supplying oil to two camshafts.

19. The valve train lubricating structure for an internal combustion engine according to claim 1, wherein said supply path of the lubricating oil to the valve train includes a substantially horizontal section passing through a joint in a crankcase and a substantially vertical section for supplying lubricating oil to the valve train.

20. The valve train lubricating structure for an internal combustion engine according to claim 19, wherein said substantially vertical section of the supply path of the lubricating oil to the valve train includes two branches for supplying oil to two camshafts.

11. A valve train lubricating structure for an internal combustion engine, comprising:

an oil pump operatively connected for rotation with a crankshaft;

a supply path for supplying lubricating oil delivered from the oil pump to an oil gallery; and

a plurality of branch supply paths for supplying the lubricating oil to predetermined parts of the internal combustion engine, one of the plurality of branch supply paths forming a supply path of the lubricating oil to the valve train;

wherein the supply path of the lubricating oil to the oil gallery includes a check valve and the supply path for supplying lubricating oil to the valve train is branched off at a point upstream of the check valve.

12. The valve train lubricating structure for an internal combustion engine according to claim 11, wherein said oil pump is a supply feed pump for supplying lubricating oil and further including a return oil pump operatively mounted relative to said crankshaft for returning oil accumulated in a crankcase to a sump oil tank.

13. The valve train lubricating structure for an internal combustion engine according to claim 12, wherein the supply feed pump is operatively connected to the sump oil tank and further including an oil cooler and oil filter operatively connected to said supply feed pump for supplying lubricating oil from the sump oil tank to the oil cooler and oil filter.

14. The valve train lubricating structure for an internal combustion engine according to claim 13, and further including a sump oil supply path for connecting the sump oil tank and the supply feed pump and a relief valve operatively positioned relative to said sump oil supply path and said supply feed pump for regulating lubricating oil supply pressure in the supply path.

15. The valve train lubricating structure for an internal combustion engine according to claim 11, wherein the check valve in the supply path for the lubricating oil supplied to the oil gallery is automatically controlled in response to a supply pressure of the lubricating oil.

16. The valve train lubricating structure for an internal combustion engine according to claim 15, wherein said check valve suppresses a supply of lubricating oil when the engine is operated at a low speed for increasing the flow of lubricating oil to the valve train.

17. The valve train lubricating structure for an internal combustion engine according to claim 15, wherein said check valve increases a supply of lubricating oil when the engine is operated at a high speed for decreasing the flow of lubricating oil to the valve train.

18. The valve train lubricating structure for an internal combustion engine according to claim 11, wherein the supply path of the lubricating oil to the valve train includes a plurality of apertures for supplying lubricating oil to cam surfaces of the valve train.