Lubricating oil supplying system for internal combustion engine

• US 20060070600A1
• Filed: 10/03/2005
• Published: 04/06/2006
• Est. Priority Date: 10/06/2004
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hara, Seinosuke
• Granted Patent: US 7,331,323 B2
• Time in Patent Office: Days
• US Class Current: 123/196.R
• CPC Class Codes: F01L 1/46 Component parts, details, or accessories, not provided for in preceding subgroups
• CPC Class Codes: F01L 13/0026 by means of an eccentric
• CPC Class Codes: F01L 2013/0073 with an oscillating cam acting on the valve of the "Delphi" type
• CPC Class Codes: F01M 1/02 using lubricating pumps pumps in general F04; lubricating pumps per se F16N
• CPC Class Codes: F01M 2001/0215 Electrical pumps
• CPC Class Codes: F01M 2001/123 using two or more pumps
• CPC Class Codes: Y10T 137/7774 Supporting valve spring carried by supporting valve
• CPC Class Codes: Y10T 137/7777 Both valves spring biased

Abstract

A lubricating oil supplying system for an internal combustion engine includes a lubricating oil storage section for storing lubricating oil. A driven pump is driven by the internal combustion engine to suck the lubricating oil from the lubricating oil storage section and discharge the lubricating oil to a discharge passage. An electric pump is provided for sucking the lubricating oil discharged from the driven pump to the discharge passage and discharge the lubricating oil to a lubricating oil requiring section in the internal combustion engine. A controlling mechanism is provided for drivingly controlling the electric pump in accordance with a control signal. A bypass passage is provided for bypassing the driven pump. A check valve is disposed in the bypass passage to allow the lubricating oil in the lubricating oil storage section to flow only through a path bypassing said driven pump and toward side of the discharge passage.

Claims

1. A lubricating oil supplying system for an internal combustion engine, comprising:

a lubricating oil storage section for storing lubricating oil;

a driven pump driven by the internal combustion engine to suck the lubricating oil from said lubricating oil storage section and discharge the lubricating oil to a discharge passage;

an electric pump for sucking the lubricating oil discharged from said driven pump to the discharge passage and discharge the lubricating oil to a lubricating oil requiring section in the internal combustion engine;

a controlling mechanism for drivingly controlling said electric pump in accordance with a control signal;

a bypass passage for bypassing said driven pump; and

a check valve disposed in said bypass passage to allow the lubricating oil in the lubricating oil storage section to flow only through a path bypassing said driven pump and toward side of the discharge passage

2. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, further comprising a relief valve disposed in said bypass passage to allow the lubricating oil within the discharge passage to flow to a lower pressure side when a discharge pressure of the lubricating oil discharged from said driven pump to the discharge passage is not lower than a level.

3. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 2, wherein the lubricating oil flowed out through the relief valve is returned into said lubricating oil storage section at the lower pressure side, wherein said check valve is disposed inside the relief valve to allow the lubricating oil to flow only through a path from said lubricating oil storage section to the side of the discharge passage.

4. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 3, wherein the relief valve includes a plunger valve body having a pressure receiving section formed at one end side of the plunger valve body, a section defining a lower pressure chamber formed at the other end side of the plunger valve body to be in communication with said lubricating oil storage section, and a biasing member disposed in the lower pressure chamber to bias the plunger valve body in one direction, wherein a part of the lubricating oil acting on the pressure receiving section flows through the lower pressure chamber into said lubricating oil storage section when the plunger valve body moves against a biasing force of the biasing member, wherein said check valve is disposed in the pressure receiving section of the relief valve.

5. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 2, further comprising a second bypass passage for bypassing said electric pump, and a bypass valve disposed in the second bypass passage and adapted to open in accordance with a pressure at the side of the discharge passage, wherein the bypass valve is adapted to open at a pressure level lower than a pressure level at which the relief valve opens.

6. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, further comprising a second bypass passage for bypassing said electric pump, and a bypass valve disposed in the second bypass passage and adapted to open in accordance with a pressure level at the side of the discharge passage.

7. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, further comprising a second bypass passage for bypassing said electric pump, and a bypass valve disposed in the second bypass passage and adapted to open when said electric pump stops in driving.

8. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, further comprising a pressure reducing valve for reducing a pressure of the lubricating oil supplied to the lubricating oil requiring section when a pressure at a section of from said electric pump to the lubricating oil requiring section is not lower than a level.

9. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, wherein the lubricating oil requiring section includes a main oil gallery for supplying the lubricating oil to sliding sections in the internal combustion engine, and a variable valve actuation mechanism operated by oil pressure, wherein said electric pump is driven by said controlling mechanism in accordance with an operating condition of the variable valve actuation mechanism.

10. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 9, wherein the internal combustion engine is a multi-cylinder V-type engine in which the variable valve actuation mechanism is disposed in each of banks.

11. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 9, wherein the variable valve actuation mechanism is a variable valve lift mechanism.

12. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 9, wherein the variable valve actuation mechanism is a valve timing controlling mechanism.

13. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, further comprising a filter disposed between said driven pump and said electric pump.

14. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, wherein said electric pump stops in driving when an engine speed rises.

15. A lubricating oil supplying system for an internal combustion engine, as claimed in claim 1, wherein said electric pump is driven when said driven pump is failed in operation.

16. A fluid pump comprising:

a pump mechanism for sucking fluid from a storage section and discharging the fluid to a discharge section;

a plunger valve body having a pressure receiving section which is formed at one end side of said plunger valve body and opens to the discharge section, the plunger valve body being movable to release a part of fluid discharged from said pump mechanism to the discharge section to a low pressure section;

a section defining a low pressure chamber formed at the other end side of said plunger valve body and in communication with the low pressure section;

a biasing member disposed in the low pressure chamber to bias said plunger valve body in one direction; and

a check valve disposed in the pressure receiving section of said plunger valve body to allow the lubricating oil to flow through a path from said lower pressure chamber to the discharge section.

17. A fluid pump as claimed in claim 16, wherein said check valve includes a check ball for opening and closing a communicating hole formed in the pressure receiving section of said plunger valve body to communicate the low pressure chamber and the discharge section, and a retainer fixed to the pressure receiving section of said plunger valve body to accommodate and retain the check ball therein.

18. A fluid pump as claimed in claim 17, further comprising a second biasing member disposed within the retainer to bias the check ball in a direction to close the communicating hole.

19. A fluid pump as claimed in claim 17, wherein the retainer is fixedly disposed within a valve hole formed in the pressure receiving section of said plunger valve body.

20. A lubricating oil supplying system for an internal combustion engine, comprising:

a lubricating oil storage section for storing lubricating oil;

a first pump for sucking the lubricating oil from said lubricating oil storage section and discharging the lubricating oil to a discharge passage;

a second pump for sucking the lubricating oil discharged from said first pump to the discharge passage and discharging the lubricating oil to a lubricating oil requiring section in the internal combustion engine;

a bypass passage for bypassing said first pump; and

an opening and closing mechanism disposed in said bypass passage to open said bypass passage when an amount of the lubricating oil discharged from said first pump exceeds that from said second pump, and to cutoff said bypass passage when the amount of the lubricating oil discharged from said first pump is similar to that from said second pump or when the amount of the lubricating oil discharged from said second pump is lower than that from said first pump.