Oil supplying apparatus and method of controlling the same

• US 6,523,519 B2
• Filed: 02/14/2002
• Issued: 02/25/2003
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Abe, Tetsuya, Iwano, Akira, Yamashita, Keiichi
• Primary Examiner(s): Kwon, John
• Assistant Examiner(s): Ali, Hyder
• Application Number:
  US10/075,770
• Publication Number:
  US 20020069847A1
• Time in Patent Office: 376 Days
• Field of Search: 123/196.R, 123/73.AD, 184/6.22
• US Class Current: 123/196.00R
• CPC Class Codes: F15B 1/024 used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
• CPC Class Codes: F15B 11/17 using two or more pumps
• CPC Class Codes: F15B 2211/20515 Electric motor
• CPC Class Codes: F15B 2211/20523 Internal combustion engine
• CPC Class Codes: F15B 2211/20576 with multiple pumps
• CPC Class Codes: F15B 2211/212 the pressure sources being accumulators
• CPC Class Codes: F15B 2211/50536 using unloading valves controlling the supply pressure by diverting fluid to the return line
• CPC Class Codes: F15B 2211/5158 being connected to a pressure source and an output member
• CPC Class Codes: F15B 2211/526 electrically or electronically
• CPC Class Codes: F15B 2211/6313 the pressure being a load pressure
• CPC Class Codes: F15B 2211/6651 Control of the prime mover, e.g. control of the output torque or rotational speed
• CPC Class Codes: F16H 2061/0034 Accumulators for fluid pressure supply; Control thereof
• CPC Class Codes: F16H 2312/14 Going to, or coming from standby operation, e.g. for engine start-stop operation at traffic lights
• CPC Class Codes: F16H 57/0434 relating to lubrication supply, e.g. pumps arrangement of pumps F16H57/0441; Pressure control grooves with pumping effect for supplying lubricant F16H57/0428; generation and variation of line pressure for transmission control F16H61/0021
• CPC Class Codes: F16H 61/0025 Supply of control fluid; Pumps therefore
• CPC Class Codes: F16H 61/0031 using auxiliary pumps, e.g. pump driven by a different power source than the engine
• CPC Class Codes: F16H 61/66272 characterised by means for controlling the torque transmitting capability of the gearing

Abstract

An engine output shaft drives an engine driven pump. The engine driven pump pressurizes oil. An accumulator accumulates the pressurized oil. An electric motor drives a motor driven pump. When the engine rotates low speed, both the engine driven pump and the motor driven pump supply oil to an oil chamber of a belt type continuously variable transmission. If it is required to enlarge a capacity of the oil chamber quickly, the pressurized oil in the accumulator is supplied to the motor driven pump. The motor driven pump further pressurizes the pressurized oil in the accumulator and supplies it into the oil chamber. It is possible to supply a sufficient amount of oil to the continuously variable transmission. Additionally, since the system may be constructed by using a small type engine driven pump, it is possible to improve fuel efficiency.

Claims

1. An oil supplying apparatus comprising:

an engine driven pump driven by an output shaft of an internal combustion engine;

a motor driven pump driven electrically and independently of the output shaft; and

a controller for operating said motor driven pump;

wherein;

said motor driven pump is operable in oil; and

said motor driven pump is disposed in an oil tank and supplies oil to an automatic transmission.

2. An oil supplying apparatus according to claim 1, further comprising a pressure regulator for regulating a pressure of oil discharged from said motor driven pump.

3. An oil supplying apparatus according to claim 1 further comprising a first supply line for supplying oil discharged by said engine driven pump and a second supply line for supplying oil discharged by said motor driven pump, wherein said first supply line and said second supply line are arranged in parallel.

4. An oil supplying apparatus according to claim 1 wherein said motor driven pump is started simultaneously with a stop of said internal combustion engine.

5. An oil supplying apparatus according to claim 4 wherein said motor driven pump is continuously driven during said stop of said engine.

6. An oil supplying apparatus according to claim 4 wherein said motor driven pump is driven by a constant voltage during said stop of said engine.

7. An oil supplying apparatus according to claim 1 wherein said motor driven pump is started before a stop of said internal combustion engine.

8. An oil supplying apparatus according to claim 1 wherein said motor driven pump is started after a stop of said internal combustion engine.

9. A method for controlling an oil supplying apparatus for supplying oil to an automatic transmission of a vehicle, said oil supplying apparatus comprising an engine driven pump driven by an output shaft of an internal combustion engine, a motor driven pump driven electrically and independently of said output shaft, and an idle-stop controller for stopping said engine in response to a continuous stop of said vehicle for not less than a limited time, comprising:

starting said motor driven pump before said stop of said internal combustion engine by said idle-stop controller;

wherein said motor driven pump is started in response to an elapse of more than one second from said stop of said vehicle.

10. A method for controlling an oil supplying apparatus for supplying oil to an automatic transmission of a vehicle, said oil supplying apparatus comprising an engine driven pump driven by an output shaft of an internal combustion engine, a motor driven pump driven electrically and independently of said output shaft, and an idle-stop controller for stopping said engine in response to a continuous stop of said vehicle for not less than a limited time, comprising:

starting said motor driven pump after said stop of said internal combustion engine by said idle-stop controller;

wherein said motor driven pump is constructed to supply a secondary oil pressure of a continuously variable transmission, and wherein said time from said stop of said internal combustion engine to said starting of said motor driven pump is set according to a holding characteristic of said secondary oil pressure after said internal combustion engine is stopped by said idle-stop controller.

11. A method for controlling an oil supplying apparatus according to claim 10, wherein said continuously variable transmission has a primary pulley and a secondary pulley which are connected by a belt, and wherein said motor driven pump is started in a period of time of which said secondary oil pressure is maintained higher than a pressure that can hold said belt.

12. A method for controlling an oil supplying apparatus for supplying oil to an automatic transmission of a vehicle, said oil supplying apparatus comprising an engine driven pump driven by an output shaft of an internal combustion engine, a motor driven pump driven electrically and independently of said output shaft, and an idle-stop controller for stopping said engine in response to a continuous stop of said vehicle for not less than a limited time, comprising:

starting said motor driven pump simultaneously with said stop of said internal combustion engine by said idle-stop controller;

wherein said motor driven pump is intermittently driven during said stop of said engine.

13. A method for controlling an oil supplying apparatus for supplying oil to an automatic transmission of a vehicle, said oil supplying apparatus comprising an engine driven pump driven by an output shaft of an internal combustion engine, a motor driven pump driven electrically and independently of said output shaft, and an idle-stop controller for stopping said engine in response to a continuous stop of said vehicle for not less than a limited time, comprising:

starting said motor driven pump simultaneously with said stop of said internal combustion engine by said idle-stop controller;

wherein said motor driven pump is driven by varying a voltage during said stop of said engine.

14. A method for controlling an oil supplying apparatus for supplying oil to an automatic transmission of a vehicle, said oil supplying apparatus comprising an engine driven pump driven by an output shaft of an internal combustion engine, a motor driven pump driven electrically and independently of said output shaft, and an idle-stop controller for stopping said engine in response to a continuous stop of said vehicle for not less than a limited time, comprising:

starting said motor driven pump simultaneously with said stop of said internal combustion engine by said idle-stop controller;

wherein said motor driven pump is disposed in an oil tank of said automatic transmission.

15. A method for controlling an oil supplying apparatus according to claim 14, further comprising a pressure regulator for regulating a discharged pressure of said motor driven pump.