Vehicle driving device

Patent metadata

Field	Value
Publication number	US-12404828-B2
Application number	US-202418765492-A
Country	US
Kind code	B2
Filing date	Jul 8, 2024
Priority date	Mar 24, 2023
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A vehicle driving device includes an engine, an electric pump, an electric heater, a starter motor, and a control system. The control system calculates a first actual viscosity of an engine oil based on a load torque of an electric pump. The control system causes an electric heater to operate by supplying a first energy to the electric heater and calculates a second actual viscosity of the engine oil based on the load torque of the electric pump. The control system calculates, based on the second actual viscosity of the engine oil and a target viscosity of the engine oil, a second energy that is to be supplied to the electric heater. The control system causes the electric heater to operate by supplying the second energy to the electric heater and then drives a starter motor so as to cause an output shaft to perform starting rotation.

First claim

The invention claimed is:

1. A vehicle driving device including an engine, the vehicle driving device comprising:
an electric pump provided in the engine and configured to pump an engine oil;
an electric heater provided in the engine and configured to heat the engine oil;
a starter motor provided in the engine and configured to cause an output shaft to perform starting rotation; and
a control system comprising a processor and a memory communicably coupled to each other, the control system being configured to control the electric pump, the electric heater, and the starter motor,
wherein the control system is configured to execute
a first step of driving the electric pump before startup of the engine and calculating a first actual viscosity of the engine oil based on a load torque of the electric pump,
a second step of causing the electric heater to operate by supplying a first energy to the electric heater, driving the electric pump after the electric heater has been caused to operate and before the startup of the engine, and calculating a second actual viscosity of the engine oil based on the load torque of the electric pump,
a third step of calculating, based on the second actual viscosity of the engine oil and a target viscosity of the engine oil, a second energy to be supplied to the electric heater, and
a fourth step of causing the electric heater to operate by supplying the second energy to the electric heater and then driving the starter motor to cause the output shaft to perform starting rotation.

2. The vehicle driving device according to claim 1 ,
wherein, in the fourth step, the control system is configured to
cause the electric heater to operate by supplying the second energy to the electric heater, then drive the electric pump, and then drive the starter motor to cause the output shaft to perform starting rotation.

3. The vehicle driving device according to claim 1 ,
wherein, in the first step, the control system is configured to
calculate the first actual viscosity such that the first actual viscosity increases as the load torque of the electric pump increases.

4. The vehicle driving device according to claim 1 ,
wherein, in the second step, the control system is configured to
calculate the second actual viscosity such that the second actual viscosity increases as the load torque of the electric pump increases.

5. The vehicle driving device according to claim 1 ,
wherein, in the third step, the control system is configured to
calculate the second energy such that the second energy increases as a difference between the second actual viscosity and the target viscosity increases.

6. The vehicle driving device according to claim 1 ,
wherein, in the third step, the control system is configured to
calculate a viscosity change characteristic of the engine oil based on the first actual viscosity, the second actual viscosity, and the first energy, and
calculate the second energy based on the viscosity change characteristic, the second actual viscosity, and the target viscosity.

7. The vehicle driving device according to claim 1 ,
wherein the control system is configured to
calculate a first starting energy consumed by the starter motor when a viscosity of the engine oil is equal to the target viscosity,
calculate a second starting energy consumed by the starter motor when a viscosity of the engine oil is equal to the second actual viscosity, and
execute the fourth step when an engine startup condition is satisfied in a situation in which a sum of the first starting energy and the second energy is lower than the second starting energy.

8. The vehicle driving device according to claim 7 ,
wherein the control system is configured to, when an engine startup condition is satisfied in a situation in which a sum of the first starting energy and the second energy is higher than the second starting energy,
prohibit execution of the fourth step and drives, without causing the electric heater to operate, the starter motor to cause the output shaft to perform starting rotation.

9. The vehicle driving device according to claim 7 ,
wherein the control system is configured to calculate the first starting energy such that the first starting energy increases as the target viscosity increases, and
wherein the control system is configured to calculate the second starting energy such that the second starting energy increases as the second actual viscosity increases.

10. The vehicle driving device according to claim 1 , further comprising:
a driving motor configured to be coupled to at least one wheel.

Assignees

• Subaru Corp

Inventors

• Kusaka Yu
• Cao Man

Classifications

• Y02T10/62

  Hybrid vehicles · CPC title

• F01M2005/008

  Lubrication means facilitating engine starting · CPC title

• F01M2001/0215

  Electrical pumps · CPC title

• F01M5/001

  Heating · CPC title

• F01M1/02

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · CPC title