Heat management system for electric vehicle

Patent metadata

Field	Value
Publication number	US-11649746-B2
Application number	US-202117197030-A
Country	US
Kind code	B2
Filing date	Mar 10, 2021
Priority date	Mar 25, 2020
Publication date	May 16, 2023
Grant date	May 16, 2023

Abstract

A heat management system disclosed herein is used for an electric vehicle. The heat management system may include an oil cooler, an oil pump, a converter cooler, a first heat exchanger, a second heat exchanger, a first channel, a second channel, a channel valve, a bypass channel, and a controller. The channel valve may be configured to select a first valve position and a second valve position. The bypass channel may be configured to allow the first heat medium to bypass the first heat exchanger and circulate between the oil cooler and the converter cooler when the second valve position is selected. The controller may be configured to control the channel valve such that the channel valve selects the first valve position and activate the oil pump in response to the temperature of the first heat medium in the first channel becoming higher than a predetermined upper limit temperature.

First claim

What is claimed is:

1. A heat management system for an electric vehicle, comprising:
an oil cooler configured to cool oil by first heat medium which is different from the oil, the oil being used to cool a traction motor, wherein heat of the traction motor is transferred to the first medium via the oil in the oil cooler;
an oil circulation path configured to circulate the oil between the oil cooler and the traction motor;
an oil pump connected to the oil circulation path;
a converter cooler configured to cool a power converter configured to supply electric power to the traction motor by the first heat medium without intervention of the oil;
a first heat exchanger configured to exchange heat between the first heat medium and outside air;
a second heat exchanger configured to exchange heat between second heat medium for an air conditioner of a cabin and the first heat medium;
a first channel in which the first heat medium flows, the first channel extending through the oil cooler and the converter cooler and connected to an inlet and an outlet of the first heat exchanger;
a second channel, which is independent from the oil circulation path, in which the first heat medium flows, the second channel extending through the second heat exchanger and connected to the inlet and the outlet of the first heat exchanger;
a channel valve configured to select a first valve position and a second valve position, wherein at the first valve position, the channel valve allows a flow of the first heat medium from the first channel to the first heat exchanger and cuts off the flow of the first heat medium from the second channel to the first heat exchanger, and at the second valve position, the channel valve allows the flow of the first heat medium from the second channel to the first heat exchanger and cuts off the flow of the first heat medium from the first channel to the first heat exchanger;
a bypass channel configured to allow the first heat medium to bypass the first heat exchanger and circulate between the oil cooler and the converter cooler when the second valve position is selected; and
a controller configured to control the channel valve and the oil pump,
wherein
the controller is configured to control the channel valve such that the channel valve selects the first valve position and activate the oil pump in response to a temperature of the first heat medium in the first channel becoming higher than a predetermined upper limit temperature.

2. The heat management system of claim 1 , wherein the controller is configured to:
execute a heat pump mode in which the channel valve selects the second valve position, the first heat exchanger transfers heat from the outside air to the first heat medium, and the second heat exchanger transfers heat from the first heat medium to the second heat medium; and
switch the channel valve from the second valve position to the first valve position and activate the oil pump in response to a difference of temperatures of the first heat medium at the inlet and the outlet of the first heat exchanger becoming smaller than a predetermined temperature difference threshold while executing the heat pump mode.

3. The heat management system of claim 2 , wherein the controller is configured to:
inactivate the oil pump in response to a temperature of the oil becoming lower than a first lower limit temperature while not executing the heat pump mode; and
inactivate the oil pump in response to the temperature of the oil becoming lower than a second lower limit temperature while executing the heat pump mode, the second lower limit temperature being lower than the first lower limit temperature.

4. The heat management system of claim 1 , wherein
the converter cooler comprises a first converter cooler configured to cool a first converter included in the converter and a second converter cooler configured to cool a second converter included in the converter,
the heat management system further comprises a temperature sensor disposed in the first channel between the first converter cooler and the second converter cooler, and
the controller is configured to control the channel valve such that the channel valve selects the first valve position and activates the oil pump in response to a measurement of the temperature sensor becoming higher than the predetermined upper limit temperature.

Assignees

• Toyota Motor Co Ltd
• Subaru Corp

Inventors

• Hasegawa Yoshio
• Ohashi Hiroo
• Furukawa Satoshi
• Ishihara Yoshihiro

Classifications

• B60H1/22

  the heat source being other than the propulsion plant {(B60H1/00492 takes precedence)} · CPC title

• F01M5/002 Primary

  Cooling · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• B60H1/004

  for vehicles having a combustion engine and electric drive means, e.g. hybrid electric vehicles · CPC title

• B60H1/2218

  controlling the operation of electric heaters · CPC title