Cooling system, control method of cooling system, and vehicle equipped with cooling system

• US 8,151,917 B2
• Filed: 10/20/2006
• Issued: 04/10/2012
• Est. Priority Date: 10/25/2005
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Suzuki, Takashi
• Primary Examiner(s): Shriver, II, J. Allen
• Assistant Examiner(s): Follman, Brodie
• Application Number:
  US11/992,747
• Publication Number:
  US 20090139686A1
• Time in Patent Office: 1,999 Days
• Field of Search: 180/65.275, 180/68.1, 180/68.2, 180/68.3, 180/68.4, 165/42, 165/51, 165/287, 165/294, 165/296, 165/297, 165/300
• US Class Current: 180/65.275
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 11/02 with liquid cooling
• CPC Class Codes: B60K 2001/003 with means for cooling the electrical propulsion units
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: F01P 2005/125 Driving auxiliary pumps electrically
• CPC Class Codes: F01P 2025/62 Load
• CPC Class Codes: F01P 2025/64 Number of revolutions
• CPC Class Codes: F01P 2050/24 Hybrid vehicles
• CPC Class Codes: F01P 5/12 : Pump-driving arrangements
• CPC Class Codes: F01P 7/164 : by varying pump speed
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles

Abstract

A cooling system is equipped with a circulation flow path arranged to flow a coolant into an engine, a motor drive system flow path branched off from the circulation flow path and arranged to flow the coolant into a motor drive system, a flow rate distribution regulator provided at a junction of the circulation flow path and the motor drive system flow path, and an electric pump configured to pressure-feed the coolant through the circulation flow path. In the cooling system, the procedure of flow rate control sets an engine flow rate demand Vwe based on a rotation speed Ne and a torque te of the engine and a coolant temperature Te (step S110), while setting a motor flow rate demand Vwm based on an inverter current Iinv of the motor drive system and the coolant temperature Te (step S120). The flow rate distribution regulator and the electric pump are then controlled to make a flow rate of the coolant flowed into the engine and a flow rate of the coolant flowed into motors and inverters included in the motor drive system respectively equal to the set engine flow rate demand Vwe and the set motor flow rate demand Vwm (steps S130 and S140).

Claims

1. A cooling system provided for a drive train, which has a first drive system including a first heat-generating drive source and a second drive system including a second heat-generating drive source, the cooling system comprising:

a circulation flow path arranged to flow a cooling medium into the first drive system;

a second drive system flow path branched off from the circulation flow path and arranged to bypass the first drive system and thereby flow the cooling medium into the second drive system;

a flow rate distribution regulator configured to regulate a distribution ratio of a flow rate of the cooling medium flowed into the first drive system to a flow rate of the cooling medium flowed into the second drive system with bypassing the first drive system;

an electric pressure feeder configured to pressure-feed the cooling medium through the circulation flow path;

a cooling medium temperature detector configured to measure a temperature of the cooling medium;

a first state detector configured to detect a driving state of the first drive system;

a second state detector configured to detect a driving state of the second drive system;

a flow rate demand setting module configured to set a first flow rate demand required for cooling down the first drive system based on the measured temperature of the cooling medium and the detected driving state of the first drive system and to set a second flow rate demand required for cooling down the second drive system based on the measured temperature of the cooling medium and the detected driving state of the second drive system; and

a controller configured to control the flow rate distribution regulator and the electric pressure feeder to make the flow rate of the cooling medium flowed into the first drive system and the flow rate of the cooling medium flowed into the second drive system respectively equal to the set first flow rate demand and the set second flow rate demand.

2. The cooling system in accordance with claim 1, wherein the first drive system includes an internal combustion engine as the first drive source,

the second drive system includes a motor as the second drive source and a driving circuit for driving the motor,

the first state detector detects a rotation speed and a torque of the internal combustion engine as the driving state of the first drive system, and

the second state detector detects a value of electric current flowing through the driving circuit as the driving state of the second drive system.

3. The cooling system in accordance with claim 1, wherein the cooling medium temperature detector is located in an upstream of the first drive system on the circulation flow path,

the cooling system further including:

a radiator configured to cool down the cooling medium by heat exchange with outside air;

a bypass passage branched off from the circulation flow path and arranged to bypass the radiator and thereby flow the cooling medium from a downstream of the first drive system to an upstream of the cooling medium temperature detector; and

a switchover mechanism provided at a junction of the circulation flow path and the bypass passage and configured to switch over a flow passage of the cooling medium to flow the cooling medium through the radiator when a temperature of the cooling medium flowing through the junction is not lower than a preset level and to flow the cooling medium with bypassing the radiator when the temperature of the cooling medium flowing through the junction is lower than the preset level.

4. A vehicle equipped with a first drive system including a first heat-generating drive source and with a second drive system including a second heat-generating drive source, the vehicle comprising:

a circulation flow path arranged to flow a cooling medium into the first drive system;

a second drive system flow path branched off from the circulation flow path and arranged to bypass the first drive system and thereby flow the cooling medium into the second drive system;

a flow rate distribution regulator configured to regulate a distribution ratio of a flow rate of the cooling medium flowed into the first drive system to a flow rate of the cooling medium flowed into the second drive system with bypassing the first drive system;

an electric pressure feeder configured to pressure-feed the cooling medium through the circulation flow path;

a cooling medium temperature detector configured to measure a temperature of the cooling medium;

a first state detector configured to detect a driving state of the first drive system;

a second state detector configured to detect a driving state of the second drive system;

a flow rate demand setting module configured to set a first flow rate demand required for cooling down the first drive system based on the measured temperature of the cooling medium and the detected driving state of the first drive system and to set a second flow rate demand required for cooling down the second drive system based on the measured temperature of the cooling medium and the detected driving state of the second drive system; and

a controller configured to control the flow rate distribution regulator and the electric pressure feeder to make the flow rate of the cooling medium flowed into the first drive system and the flow rate of the cooling medium flowed into the second drive system respectively equal to the set first flow rate demand and the set second flow rate demand.

5. The vehicle in accordance with claim 4, wherein the first drive system includes an internal combustion engine as the first drive source,

the second drive system includes a motor as the second drive source and a driving circuit for driving the motor,

the first state detector detects a rotation speed and a torque of the internal combustion engine as the driving state of the first drive system, and

the second state detector detects a value of electric current flowing through the driving circuit as the driving state of the second drive system.

6. The vehicle in accordance with claim 4, wherein the cooling medium temperature detector is located in an upstream of the first drive system on the circulation flow path,

the cooling system further including:

a radiator configured to cool down the cooling medium by heat exchange with outside air;

a bypass passage branched off from the circulation flow path and arranged to bypass the radiator and thereby flow the cooling medium from a downstream of the first drive system to an upstream of the cooling medium temperature detector; and

a switchover mechanism provided at a junction of the circulation flow path and the bypass passage and configured to switch over a flow passage of the cooling medium to flow the cooling medium through the radiator when a temperature of the cooling medium flowing through the junction is not lower than a preset level and to flow the cooling medium with bypassing the radiator when the temperature of the cooling medium flowing through the junction is lower than the preset level.

7. A control method of a cooling system, the cooling system having:

a circulation flow path arranged to flow a cooling medium into a first drive system including a first heat-generating drive source;

a second drive system flow path branched off from the circulation flow path and arranged to bypass the first drive system and thereby flow the cooling medium into a second drive system including a second heat-generating drive source;

a flow rate distribution regulator configured to regulate a distribution ratio of a flow rate of the cooling medium flowed into the first drive system to a flow rate of the cooling medium flowed into the second drive system with bypassing the first drive system; and

an electric pressure feeder configured to pressure-feed the cooling medium through the circulation flow path,

the control method comprising;

setting a first flow rate demand required for cooling down the first drive system based on a temperature of the cooling medium and a driving state of the first drive system, while setting a second flow rate demand required for cooling down the second drive system based on the temperature of the cooling medium and a driving state of the second drive system; and

controlling the flow rate distribution regulator and the electric pressure feeder to make the flow rate of the cooling medium flowed into the first drive system and the flow rate of the cooling medium flowed into the second drive system respectively equal to the set first flow rate demand and the set second flow rate demand.