U.S. patent application number 13/670050 was filed with the patent office on 2013-05-09 for battery warm-up apparatus and method thereof.
This patent application is currently assigned to AISIN SEIKI KABUSHIKI KAISHA. The applicant listed for this patent is Aisin Seiki Kabushiki Kaisha. Invention is credited to Keisuke MISHIMA.
Application Number | 20130111932 13/670050 |
Document ID | / |
Family ID | 47146214 |
Filed Date | 2013-05-09 |
United States Patent
Application |
20130111932 |
Kind Code |
A1 |
MISHIMA; Keisuke |
May 9, 2013 |
BATTERY WARM-UP APPARATUS AND METHOD THEREOF
Abstract
A the battery warm-up apparatus includes an electric motor, a
battery, an electric generator for charging the battery, an engine
for driving the electric generator, a refrigeration circuit
arranged to pass through inside the engine in a manner that a
temperature medium flows through an inside thereof, a heat
exchanger, a battery-heating channel branched from the
refrigeration circuit, arranged to pass through the battery and
connected to the refrigeration circuit again, a first switching
valve arranged at a first portion of the refrigeration circuit, the
battery-heating channel being branched from the refrigeration
circuit at the first portion, the first switching valve connecting
and disconnecting the battery-heating channel relative to the
refrigeration circuit, a battery temperature sensor, and a
controller for operating the first switching valve on the basis of
temperature of the battery and for allowing the temperature medium
to flow through the battery-heating channel.
Inventors: |
MISHIMA; Keisuke;
(Takahama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aisin Seiki Kabushiki Kaisha; |
Kariya-shi |
|
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi
JP
|
Family ID: |
47146214 |
Appl. No.: |
13/670050 |
Filed: |
November 6, 2012 |
Current U.S.
Class: |
62/79 ;
62/159 |
Current CPC
Class: |
B60L 58/27 20190201;
H01M 10/486 20130101; B60L 2240/545 20130101; H01M 10/63 20150401;
B60K 2001/003 20130101; H01M 10/615 20150401; B60K 11/02 20130101;
H01M 10/6568 20150401; F25B 29/00 20130101; H01M 10/663 20150401;
Y02E 60/10 20130101; B60K 1/00 20130101; H01M 10/625 20150401; Y02T
10/70 20130101; B60K 2001/008 20130101; B60K 2001/001 20130101 |
Class at
Publication: |
62/79 ;
62/159 |
International
Class: |
F25B 29/00 20060101
F25B029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2011 |
JP |
2011-243404 |
Claims
1. A battery warm-up apparatus, comprising: an electric motor for
driving a wheel; a battery for supplying electric power to the
electric motor; an electric generator for charging the battery; an
engine for driving the electric generator without driving the
wheel; a refrigeration circuit arranged to pass through inside the
engine and constituting a closed circuit in a manner that a
temperature medium flows through an inside of the refrigeration
circuit; a heat exchanger arranged on the refrigeration circuit; a
battery-heating channel branched from the refrigeration circuit,
arranged to pass through the battery and connected to the
refrigeration circuit again; a first switching valve arranged at a
first portion of the refrigeration circuit, the battery-heating
channel being branched from the refrigeration circuit at the first
portion, the first switching valve connecting and disconnecting the
battery-heating channel relative to the refrigeration circuit; a
battery temperature sensor for detecting temperature of the
battery; and a controller for operating the first switching valve
on the basis of the temperature of the battery which is detected by
the battery temperature sensor and for allowing the temperature
medium to flow through the battery-heating channel.
2. The battery warm-up apparatus according to claim 1, further
comprising: a heater core for a vehicle cabin heater, the heater
core being arranged on the battery-heating channel.
3. The battery warm-up apparatus according to claim 1, wherein an
engine temperature sensor for detecting temperature of the engine
is provided at the engine, a bypass path is connected to the
refrigeration circuit in a manner that the bypass path bypasses the
heat exchanger, a second switching valve is arranged at a second
portion of the refrigeration circuit, the bypass path is branched
from the refrigeration circuit at the second portion, the second
switching valve selectively allows the temperature medium to flow
into the heat exchanger and into the bypass path, and the
controller operates the second switching valve on the basis of the
temperature of the battery which is detected by the battery
temperature sensor or on the basis of the temperature of the engine
which is detected by the engine temperature sensor, and thereby
stops the temperature medium from flowing to the heat
exchanger.
4. The battery warm-up apparatus according to claim 3, wherein the
controller actuates the engine thereby disconnecting the
battery-heating channel from the refrigeration circuit by means of
the first switching valve and disconnecting the heat exchanger from
the refrigeration circuit by means of the second switching valve
and allows the temperature medium to circulate inside the
refrigeration circuit and the bypass path in a case where the
temperature of the engine which is detected by the engine
temperature sensor is less than a first threshold temperature which
is predetermined or in a case where the temperature of the engine
which is detected by the engine temperature sensor is equal to or
less than the first threshold temperature.
5. The battery warm-up apparatus according to claim 4, wherein the
controller actuates the engine, operates the first switching valve
thereby connecting the battery-heating channel to the refrigeration
circuit, and allows the temperature medium to circulate inside the
refrigeration circuit, the battery-heating channel and the bypass
path and to be supplied to the battery in a case where the
temperature of the engine which is detected by the engine
temperature sensor reaches the first threshold temperature or in a
case where the temperature of the engine which is detected by the
engine temperature sensor exceeds the first threshold temperature,
and in a case where the temperature of the battery is less than a
second threshold temperature which is higher than the first
threshold temperature, or in a case where the temperature of the
battery is equal to or less than the second threshold
temperature.
6. The battery warm-up apparatus according to claim 5, wherein the
controller actuates the engine, operates the second switching valve
thereby disconnecting the bypass path from the refrigeration
circuit, and allows the temperature medium to circulate inside the
refrigeration circuit and the battery-heating channel and to be
supplied to the battery and to the heat exchanger in a case where
the temperature of the battery which is detected by the battery
temperature sensor reaches the second threshold temperature or in a
case where the temperature of the battery which is detected by the
battery temperature sensor exceeds the second threshold
temperature.
7. A method of warming up a battery for a vehicle, the vehicle
including an electric motor for driving a wheel, a battery for
supplying electric power to the electric motor, an electric
generator for charging the battery, an engine for driving the
electric generator without driving the wheel, a refrigeration
circuit arranged to pass through inside the engine and constituting
a closed circuit in a manner that a temperature medium flows
through an inside of the refrigeration circuit, a heat exchanger
arranged on the refrigeration circuit, a battery-heating channel
branched from the refrigeration circuit, arranged to pass through
the battery and connected to the refrigeration circuit again, a
first switching valve arranged at a first portion of the
refrigeration circuit, the battery-heating channel being branched
from the refrigeration circuit at the first portion, the first
switching valve connecting and disconnecting the battery-heating
channel relative to the refrigeration circuit, and a battery
temperature sensor for detecting temperature of the battery, the
method of warming up the battery comprising the steps of: operating
the first switching valve on the basis of the temperature of the
battery which is detected by the battery temperature sensor and
allowing the temperature medium to flow through the battery-heating
channel.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
U.S.C. .sctn.119 to Japanese Patent Application 2011-243404, filed
on Nov. 7, 2011, the entire content of which is incorporated herein
by reference.
TECHNICAL FIELD
[0002] This disclosure generally relates to a battery warm-up
apparatus and a method thereof.
BACKGROUND DISCUSSION
[0003] A known heating apparatus for an engine and a battery of a
hybrid vehicle is disclosed in JP2001-234840A (hereinafter referred
to as Patent reference 1). The heating apparatus disclosed in
Patent reference 1 includes a heat source for heating the engine
and the battery in a case where temperature of the engine and
temperature of the battery are lower than predetermined
temperatures at low temperatures. According to the heating
apparatus disclosed in Patent reference 1, fuel is combusted at the
heat source and a heat medium that is heated up is supplied to the
engine or to the battery. Thus, the temperatures of the engine and
the battery of the hybrid vehicle are increased, and therefore
startability at low temperatures is enhanced without using a
starter for starting.
[0004] A known battery warm-up apparatus for a hybrid vehicle is
disclosed in, for example, JPH7-79503A (hereinafter referred to as
Patent reference 2). According to the known battery warm-up
apparatus for the hybrid vehicle disclosed in Patent reference 2,
output voltage of an electric generator is increased up to
allowable charging voltage of a battery after an engine is started.
As the charging voltage of the battery increases, heat generation
due to a charging resistance increases, thereby facilitating
warming up of the battery. Further, a known art related to
in-vehicle heating, in which a temperature medium that is heated by
means of a water-based PTC (Positive Temperature Coefficient)
heater, instead of by means of engine exhaust heat, is circulated
at low temperatures, is disclosed in "PTC Heater for Electric
Vehicles and Plug-in Hybrid Vehicles Using Water Heat Carrier"
Mitsubishi Heavy Industries Technical Review Vol. 47 No. 4 (2010),
pages 29 to 31 of a special feature of automobile-related
technologies (hereinafter referred to as Patent reference 3).
According to the known art disclosed in Patent reference 3, a
constant heating ability is performed despite voltage fluctuations
of a battery. Accordingly, it is considered that the aforementioned
water-based PTC heater is used for heating the battery during
start-up at low temperatures.
[0005] According to the known heating apparatus disclosed in Patent
reference 1, however, a combustion device serving as the heat
source is needed separately from, that is, in addition to an engine
for driving a vehicle. This may lead to a large-sized heating
apparatus, deterioration of efficiency in heat generation, and
const increase. Further, according to the known battery warm-up
apparatus disclosed in Patent reference 2, because the battery is
continually charged and discharged for a long period of time at low
temperatures, the battery may be deteriorated, which may reduce a
service life of the battery.
[0006] Further, in a case where the known water-based PTC heater
disclosed in Patent reference 3 is used for warming up the battery
during the start-up at low temperatures, a large amount of electric
power is consumed at the heater, and thus load applied to the
battery increases. This may lead to a reduction in a driving range
of a hybrid vehicle or an EV (Electric Vehicle). A need thus exists
for a battery warm-up apparatus and a method thereof, which is not
susceptible to the drawback mentioned above.
SUMMARY
[0007] According to an aspect of this disclosure, a battery warm-up
apparatus includes an electric motor for driving a wheel, a battery
for supplying electric power to the electric motor, an electric
generator for charging the battery, an engine for driving the
electric generator without driving the wheel, a refrigeration
circuit arranged to pass through inside the engine and constituting
a closed circuit in a manner that a temperature medium flows
through an inside of the refrigeration circuit, a heat exchanger
arranged on the refrigeration circuit, a battery-heating channel
branched from the refrigeration circuit, arranged to pass through
the battery and connected to the refrigeration circuit again, a
first switching valve arranged at a first portion of the
refrigeration circuit, at which the battery-heating channel is
branched from the refrigeration circuit, the first switching valve
connecting and disconnecting the battery-heating channel relative
to the refrigeration circuit, a battery temperature sensor for
detecting temperature of the battery, and a controller for
operating the first switching valve on the basis of the temperature
of the battery which is detected by the battery temperature sensor
and for allowing the temperature medium to flow through the
battery-heating channel.
[0008] According to an aspect of this disclosure, a method of
warming up a battery for a vehicle including an electric motor for
driving a wheel, a battery for supplying electric power to the
electric motor, an electric generator for charging the battery, an
engine for driving the electric generator without driving the
wheel, a refrigeration circuit arranged to pass through inside the
engine and constituting a closed circuit in a manner that a
temperature medium flows through an inside of the refrigeration
circuit, a heat exchanger arranged on the refrigeration circuit, a
battery-heating channel branched from the refrigeration circuit,
arranged to pass through the battery and connected to the
refrigeration circuit again, a first switching valve arranged at a
first portion of the refrigeration circuit, the battery-heating
channel being branched from the refrigeration circuit at the first
portion, the first switching valve connecting and disconnecting the
battery-heating channel relative to the refrigeration circuit, and
a battery temperature sensor for detecting temperature of the
battery includes the steps of operating the first switching valve
on the basis of the temperature of the battery which is detected by
the battery temperature sensor and allowing the temperature medium
to flow through the battery-heating channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The foregoing and additional features and characteristics of
this disclosure will become more apparent from the following
detailed description considered with the reference to the
accompanying drawings, wherein:
[0010] FIG. 1 is a block diagram illustrating, in a simplified
manner, a running system or a power train of a hybrid vehicle
mounted with a battery warm-up apparatus according to an embodiment
disclosed here;
[0011] FIG. 2 is a simplified diagram illustrating a relationship
between temperature of each of an engine and a battery, and each of
operation modes according to the battery warm-up apparatus
illustrated in FIG. 1;
[0012] FIG. 3 is a table illustrating operation states of the
engine and each of three-way valves in each of the operation modes
illustrated in FIG. 2;
[0013] FIG. 4 is a flowchart illustrating a controlling method of
the battery warm-up apparatus by a controller illustrated in FIG.
1;
[0014] FIG. 5 is a block diagram illustrating a flow state of
coolant fluid in an engine warm-up mode according to the
embodiment;
[0015] FIG. 6 is a block diagram illustrating a flow state of the
coolant fluid in a battery warm-up mode 1 according to the
embodiment;
[0016] FIG. 7 is a block diagram illustrating a flow state of the
coolant fluid in a battery warm-up mode 2 according to the
embodiment; and
[0017] FIG. 8 is a block diagram illustrating a flow state of the
coolant fluid in a normal operation mode according to the
embodiment.
DETAILED DESCRIPTION
[0018] An embodiment of a battery warm-up apparatus related to this
disclosure will be explained with reference to FIGS. 1 to 8. FIG. 1
schematically illustrates a powertrain of a hybrid vehicle mounted
with the battery warm-up apparatus of the embodiment. A vehicle
illustrated in FIG. 1 corresponds to a front-wheel drive vehicle.
The left side in FIG. 1 corresponds to a vehicle front. However,
the embodiment is not limited thereto and may be applied to, for
example, a rear-wheel drive vehicle or to a four-wheel drive
vehicle. Further, in FIG. 1, each of bold lines illustrates a power
supply line and each of hatched passages corresponds to a flow
passage of a coolant fluid. In FIGS. 5 to 8, each of the hatched
passages corresponds to a pipe line through which the coolant fluid
actually flows in each of operation modes.
[0019] As illustrated in FIG. 1, a vehicle V includes a right
driving wheel 1FR (corresponding to a wheel), a left driving wheel
1FL (corresponding to the wheel), a right driven wheel 1RR and a
left driven wheel 1RL. The right driving wheel 1FR and the left
driving wheel 1FL are comprehensively referred to as driving wheels
1FR and 1FL. A motor generator 2 (corresponding to an electric
motor) of the vehicle V is a synchronous machine and is
mechanically connected to the driving wheels 1FR and 1FL in order
to drive the driving wheels 1FR and 1FL. The motor generator 2 is
electrically connected to an on-vehicle battery 4 (corresponding to
a battery) via an inverter 3. The motor generator 2 (i.e., MG), the
inverter 3 and the on-vehicle battery 4 constitute a driving unit D
of the vehicle V.
[0020] An AC-DC converter 5 is connected to the on-vehicle battery
4 (for example, a lithium-ion battery, a lead storage battery, a
nickel-cadmium battery, an air battery, a sodium-sulfur battery). A
power-generation motor 6 (corresponding to an electric generator)
is electrically connected to the AC-DC converter 5. Further, an
engine 7 is mechanically connected to the power-generation motor 6
(i.e., M). The engine 7 is provided for driving the
power-generation motor 6, that is, the engine 7 does not drive the
driving wheels 1FR, 1FL. The engine 7 is constituted by an internal
combustion engine having a low displacement (a small output)
because the engine 7 is used only for driving the power-generation
motor 6. The AC-DC converter 5, the power-generation motor 6, and
the engine 7 constitute a power generating unit P of the vehicle
V.
[0021] Electric power generated by the power-generation motor 6 is
converted to direct electric current (DC), and then charged in the
on-vehicle battery 4. The electric power charged in the on-vehicle
battery 4 is converted back to alternating electric current (AC) by
the inverter 3, and then drives the motor generator 2. Further, in
a case where a braking operation is conducted at the vehicle V,
electric power generation is performed at the motor generator 2,
and thus the regenerated electric power is charged in the
on-vehicle battery 4.
[0022] A coolant pipe line 8a (corresponding to a refrigeration
circuit), which is a fluid pipe line, is connected to a water
jacket provided inside the engine 7. The coolant pipe line 8a
arranged to pass through inside the engine 7 is connected to a
radiator 9 (corresponding to a heat exchanger), thereby
constituting a closed circuit, that is, a closed-circuit flow path.
A reservoir tank 10 (i.e., RT) and an electric water pump 11 (i.e.,
WP) are provided on the coolant pipe line 8a.
[0023] The coolant pipe line 8a is filled with the coolant fluid
(corresponding to a temperature medium), which is cooling water,
and the electric water pump 11 is configured to pump the coolant
fluid stored in the reservoir tank 10 toward the engine 7. The
coolant pipe line 8a is arranged to pass through the AC-DC
converter 5 and is configured so that the coolant fluid cools the
AC-DC converter 5. The coolant pipe line 8a is configured so that
the coolant fluid flows therethrough.
[0024] A heat branch 8b (corresponding to a battery-heating
channel), which is the fluid pipe line similar to the coolant pipe
line 8a, is arranged to be branched from the coolant pipe line 8a
and is connected to the coolant pipe line 8a again. The heat branch
8b is configured so that the coolant fluid flows therethrough. The
heat branch 8b is arranged to pass through the on-vehicle battery 4
and is configured so that the coolant fluid may supply heat to the
on-vehicle battery 4.
[0025] A heater core 12a of a cabin heater 12 (corresponding to a
vehicle cabin heater) is arranged on the heat branch 8b. The heater
core 12a is a heat exchanger and is configured to allow the coolant
fluid to flow therethrough and to discharge the heat to the air.
Further, an electric heater 12b, which is heated by the electric
power supplied from the on-vehicle battery 4, is accommodated
inside the cabin heater 12. The electric heater 12b functions in a
case where a start switch of the cabin heater 12 is turned on in a
state where the coolant fluid is not flowing inside the heater core
12a. The cabin heater 12 includes a blower so that the air is blew
at the heater core 12a and at the electric heater 12b, thereby
heating an inside of the vehicle cabin. Further, a short-cut path
8c (corresponding to a bypass path), which is the fluid pipe line,
is connected to the coolant pipe line 8a so as to bypass the
radiator 9. The short-cut path 8c is configured so that the coolant
fluid flows therethrough.
[0026] As illustrated in FIG. 1, a first three-way valve 13
(corresponding to a first switching valve) is arranged at a first
portion of the coolant pipe line 8a, the first portion at which the
heat branch 8b is branched from the coolant pipe line 8a. The first
three-way valve 13 is constituted by an electromagnetic valve
including three ports. The first three-way valve 13 selectively
connects a first inlet port 13a on the coolant pipe line 8a to a
first outlet port 13b and to a first exhaust port 13c. The first
inlet port 13a is an inlet port through which the coolant fluid
from the engine 7 flows, the first outlet port 13b is an outlet
port leading to the radiator 9 and the first exhaust port 13c is an
exhaust port to the heat branch 8b. That is, the first three-way
valve 13 operates so that the heat branch 8b is brought to be
connected to the coolant pipe line 8a and to be cut off or
disconnected from the coolant pipe line 8a.
[0027] A second three-way valve 14 (corresponding to a second
switching valve) is arranged at a second portion of the coolant
pipe line 8a, the second portion at which the short-cut path 8c is
branched from the coolant pipe line 8a. In a similar way to the
first three-way valve 13, the second three-way valve 14 is
constituted by an electromagnetic valve including three ports. The
second three-way valve 14 selectively connects a second inlet port
14a to a second outlet port 14b and to a second exhaust port 14c,
each of which are on the coolant pipe line 8a. The second inlet
port 14a is connected to the first outlet port 13b of the first
three-way valve 13 via the coolant pipe line 8a, the second outlet
port 14b leads to the radiator 9 and the second exhaust port 14c is
an exhaust port to the short-cut path 8c. That is, the second
three-way valve 14 selectively allows the coolant fluid to flow
into the radiator 9 and into the short-cut path 8c.
[0028] Each of the driving unit D, the power generating unit P, the
cabin heater 12, the electric water pump 11, the first three-way
valve 13, and the second three-way valve 14 is connected to a
controller 15 so as to be controllable by the controller 15.
Further, an engine temperature sensor 7a provided at the engine 7
and a battery temperature sensor 4a provided at the on-vehicle
battery 4 are connected to the controller 15.
[0029] The battery warm-up apparatus of the embodiment is
constituted by the motor generator 2, the on-vehicle battery 4, the
power-generation motor 6, the engine 7, the coolant pipe line 8a,
the heat branch 8b, the short-cut path 8c, the radiator 9, the
heater core 12a, the first three-way valve 13, the second three-way
valve 14, the controller 15, the battery temperature sensor 4a, and
the engine temperature sensor 7a.
[0030] A controlling method of the battery warm-up apparatus, that
is, a method of warming up the battery for the vehicle V, which is
performed by the controller 15 on the basis of statues of the
vehicle V will be explained hereunder. FIG. 2 illustrates the
temperature range, that is, a vehicle operating temperature range,
in which the vehicle V is operable. In FIG. 2, the temperature
becomes higher toward an upper portion of FIG. 2. In FIG. 2, the
engine 7 performs a normal operation mainly when the temperature of
the engine 7 is equal to or greater than an engine operation
lower-limit temperature Tsc1. Further, in FIG. 2, the on-vehicle
battery 4 performs a normal operation mainly when the temperature
of the on-vehicle battery 4 is equal to or greater than a battery
operation lower-limit temperature Tsc2.
[0031] As illustrated in FIG. 2, when temperature of the engine 7
is less than the engine operation lower-limit temperature Tsc1
corresponding to a first threshold temperature (or when the
temperature of the engine 7 is equal to or less than the engine
operation lower-limit temperature Tsc1), the battery warm-up
apparatus is set to be in an engine warm-up mode. When the
temperature of the engine 7 reaches the engine operation
lower-limit temperature Tsc1 (or in a case where the temperature of
the engine 7 exceeds the engine operation lower-limit temperature
Tsc1) and when temperature of the on-vehicle battery 4 is less than
the battery operation lower-limit temperature Tsc2 corresponding to
a second threshold temperature (or when the temperature of the
on-vehicle battery 4 is equal to or less than the battery operation
lower-limit temperature Tsc2), the battery warm-up apparatus is set
to be in a battery warm-up mode 1. The battery operation
lower-limit temperature Tsc2 is higher than the engine operation
lower-limit temperature Tsc1. In a case where the temperature of
the on-vehicle battery 4 reaches the battery operation lower-limit
temperature Tsc2 (or in a case where the temperature of the
on-vehicle battery 4 exceeds the battery operation lower-limit
temperature Tsc2), the battery warm-up apparatus is set to be in a
battery warm-up mode 2. Further, in a case where the temperature of
the on-vehicle battery 4 reaches a reference upper-limit
temperature Tsh (or in a case where the temperature of the
on-vehicle battery 4 exceeds the reference upper-limit temperature
Tsh), the battery warm-up apparatus is set to be in a normal
operation mode.
[0032] As illustrated in FIG. 3, when the battery warm-up apparatus
is in the engine warm-up mode, the engine 7 is always actuated.
Further, in the engine warm-up mode, the first inlet port 13a of
the first three-way valve 13 is in communication with the first
outlet port 13b, and thus the heat branch 8b is cut off or
disconnected from the coolant pipe line 8a. Further, in the engine
warm-up mode, the second inlet port 14a of the second three-way
valve 14 is in communication with the second exhaust port 14c, and
thus the radiator 9 is cut off or disconnected from the coolant
pipe line 8a. In the engine warm-up mode, electric current does not
flow from the AC-DC converter 5 to the on-vehicle battery 4, and
thus the electric charge into the on-vehicle battery 4 is
stopped.
[0033] As illustrated in FIG. 3, when the battery warm-up apparatus
is in the battery warm-up mode 1, the engine 7 is always actuated.
Further, in the battery warm-up mode 1, the first inlet port 13a of
the first three-way valve 13 is in communication with the first
exhaust port 13c, and thus the heat branch 8b is connected to the
coolant pipe line 8a. Further, in the battery warm-up mode 1, the
second inlet port 14a of the second three-way valve 14 is in
communication with the second exhaust port 14c, and thus the
radiator 9 is cut off or disconnected from the coolant pipe line
8a. In the battery warm-up mode 1, basically, the electric current
does not flow from the AC-DC converter 5 to the on-vehicle battery
4, and thus the electric charge into the on-vehicle battery 4 is
stopped. However, it may be set so that the electric charge into
the on-vehicle battery 4 is started in the battery warm-up mode
1.
[0034] As illustrated in FIG. 3, when the battery warm-up apparatus
is in the battery warm-up mode 2, the engine 7 is always actuated.
Further, in the battery warm-up mode 2, the first inlet port 13a of
the first three-way valve 13 is in communication with the first
exhaust port 13c, and thus the heat branch 8b is connected to the
coolant pipe line 8a. Further, in the battery warm-up mode 2, the
second inlet port 14a of the second three-way valve 14 is in
communication with the second outlet port 14b, and thus the
short-cut path 8c is cut off or disconnected from the coolant pipe
line 8a. In the battery warm-up mode 2, the electric current flows
from the AC-DC converter 5 to the on-vehicle battery 4, and thus
the electric charge into the on-vehicle battery 4 is properly
conducted.
[0035] As illustrated in FIG. 3, when the battery warm-up apparatus
is in the normal operation mode, the engine 7 is actuated or driven
depending on a power generation requirement at the vehicle V.
Further, in the normal operation mode, the first inlet port 13a of
the first three-way valve 13 is in communication with the first
outlet port 13b, and thus the heat branch 8b is cut off or
disconnected from the coolant pipe line 8a. Further, in the normal
operation mode, the second inlet port 14a of the second three-way
valve 14 is in communication with the second outlet port 14b, and
thus the short-cut path 8c is cut off or disconnected from the
coolant pipe line 8a. In the normal operation mode, the electric
current flows from the AC-DC converter 5 to the on-vehicle battery
4, and thus the electric charge into the on-vehicle battery 4 is
properly conducted.
[0036] As illustrated in a flowchart of FIG. 4, in a case where an
ignition switch (i.e., IG) is activated at the vehicle V (Step
S401), the electric water pump 11 of the battery warm-up apparatus
is actuated or driven (Step S402). In a case where an engine
temperature T.sub.E detected by the engine temperature sensor 7a
and a battery temperature T.sub.B detected by the battery
temperature sensor 4a are inputted into the controller 15 (Step
S403), it is determined whether or not the engine temperature
T.sub.E is less than the engine operation lower-limit temperature
Tsc1 (Step S404).
[0037] For example, in a case where the vehicle V is started at low
temperatures and when the temperature T.sub.E is less than the
engine operation lower-limit temperature Tsc1, it is determined
that the engine 7 needs to be warmed up, and therefore the battery
warm-up apparatus is set to be in the engine warm-up mode (Step
S405). Accordingly, the engine 7 is always actuated for warming up,
the first inlet port 13a of the first three-way valve 13 is in
communication with the first outlet port 13b, and the second inlet
port 14a of the second three-way valve 14 is in communication with
the second exhaust port 14c. Consequently, the coolant fluid pumped
by the electric water pump 11 circulates inside the coolant pipe
line 8a and the short-cut path 8c (illustrated in FIG. 5). The
coolant fluid circulates among the electric water pump 11, the
engine 7, the AC-DC converter 5, the first three-way valve 13, the
second three-way valve 14 and the reservoir tank 10 in that order.
Because the coolant fluid bypasses the radiator 9, the engine 7 and
the coolant fluid are rapidly heated.
[0038] In the engine warm-up mode, each of the engine temperature
T.sub.E and the battery temperature T.sub.B is constantly detected
at a predetermined time interval (Step S403) and the engine
temperature T.sub.E is compared relative to the engine operation
lower-limit temperature Tsc1 (Step S404). When the battery warm-up
apparatus continues to be in the engine warm-up mode and in a case
where the engine temperature T.sub.E reaches the engine operation
lower-limit temperature Tsc1, it is determined whether or not the
battery temperature T.sub.B is less than the battery operation
lower-limit temperature Tsc2 (Step S406).
[0039] In a case where the battery temperature T.sub.B is less than
the battery operation lower-limit temperature Tsc2, it is
determined that the on-vehicle battery 4 needs to be warmed up, and
therefore the battery warm-up apparatus is set to be in the battery
warm-up mode 1 (Step S407). Specifically, the engine 7 is always
actuated and the first inlet port 13a of the first three-way valve
13 is in communication with the first exhaust port 13c of the first
three-way valve 13 and the second inlet port 14a of the second
three-way valve 14 is in communication with the second exhaust port
14c of the second three-way valve 14. Thus, the heat branch 8b is
connected to the coolant pipe line 8a and the radiator 9 is cut off
or disconnected from the coolant pipe line 8a. Accordingly, the
coolant fluid circulates inside the coolant pipe line 8a, the heat
branch 8b and the short-cut path 8c (as illustrated in FIG. 6). The
coolant fluid circulates among the electric water pump 11, the
engine 7, the AC-DC converter 5, the first three-way valve 13, the
on-vehicle battery 4, the heater core 12a, the second three-way
valve 14 and the reservoir tank 10 in that order.
[0040] The coolant fluid heated up by the engine 7 flows through
the heat branch 8b and warms up the on-vehicle battery 4. The
coolant fluid discharges the heat at the heater core 12a of the
cabin heater 12 as flowing through the heat branch 8b. At this
time, in a case where the start switch of the cabin heater 12 is
on, the heat discharged by the coolant fluid is used for heating
the vehicle cabin.
[0041] In the battery warm-up mode 1, each of the engine
temperature T.sub.E and the battery temperature T.sub.B is
constantly detected at the predetermined time interval (Step S403).
After the engine temperature T.sub.E is compared relative to the
engine operation lower-limit temperature Tsc1 (Step S404), the
battery temperature T.sub.B is compared relative to the battery
operation lower-limit temperature Tsc2 (Step S406). When the
battery warm-up apparatus continues to be in the battery warm-up
mode 1 and in a case where the battery temperature T.sub.B reaches
the battery operation lower-limit temperature Tsc2, it is
determined whether or not the battery temperature T.sub.B is less
than the reference upper-limit temperature Tsh (Step S408).
[0042] In a case where the battery temperature T.sub.B reaches the
battery operation lower-limit temperature Tsc2 and the battery
temperature T.sub.B is less than the reference upper-limit
temperature Tsh, it is determined that the coolant fluid needs to
be cooled down, and therefore the battery warm-up apparatus is set
to be in the battery warm-up mode 2 (Step S409). Specifically, the
engine 7 is always actuated, the first inlet port 13a of the first
three-way valve 13 is in communication with the first exhaust port
13c, and the second inlet port 14a of the second three-way valve 14
is in communication with the second outlet port 14b. Thus, the heat
branch 8b is connected to the coolant pipe line 8a, the short-cut
path 8c is cut off or disconnected from the coolant pipe line 8a,
and the radiator 9 is connected to the coolant pipe line 8a.
Accordingly, the coolant fluid circulates inside the coolant pipe
line 8a, the heat branch 8b and the radiator 9 (illustrated in FIG.
7). The coolant fluid circulates among the electric water pump 11,
the engine 7, the AC-DC converter 5, the first three-way valve 13,
the on-vehicle battery 4, the heater core 12a, the second three-way
valve 14, the radiator 9 and the reservoir tank 10 in that
order.
[0043] The coolant fluid heated up by the engine 7 flows through
the heat branch 8b and warms up the on-vehicle battery 4. After
this, the coolant fluid discharges the heat to the air at the
radiator 9, and thus is cooled down. At this time, in a case where
the start switch of the cabin heater 12 is on, the heat discharged
by the coolant fluid is used for heating the vehicle cabin in a
similar manner to that in the battery warm-up mode 1.
[0044] In the battery warm-up mode 2, the engine temperature
T.sub.E and the battery temperature T.sub.B are constantly detected
at the predetermined time interval (Step S403). After the engine
temperature T.sub.E is compared relative to the engine operation
lower-limit temperature Tsc1 (Step S404), and after the battery
temperature T.sub.B is compared relative to the battery operation
lower-limit temperature Tsc2 (Step S406), the battery temperature
T.sub.B is compared relative to the reference upper-limit
temperature Tsh (Step S408).
[0045] When the battery warm-up apparatus continues to be in the
battery warm-up mode 2 and in a case where the battery temperature
T.sub.B reaches the reference upper-limit temperature Tsh, it is
determined that the warming-up of the on-vehicle battery 4 is
completed, and then the battery warm-up apparatus is set to be in
the normal operation mode (Step S410). Specifically, the engine 7
is actuated depending on the power generation requirement at the
vehicle V, and the first inlet port 13a of the first three-way
valve 13 is in communication with the first outlet port 13b and the
second inlet port 14a of the second three-way valve 14 is in
communication with the second outlet port 14b. Thus, the heat
branch 8b is cut off or disconnected from the coolant pipe line 8a
and the radiator 9 is connected to the coolant pipe line 8a.
Accordingly, the coolant fluid circulates inside the coolant pipe
line 8a and the radiator 9 (illustrated in FIG. 8). The coolant
fluid circulates among the electric water pump 11, the engine 7,
the AC-DC converter 5, the first three-way valve 13, the second
three-way valve 14, the radiator 9 and the reservoir tank 10 in
that order. The coolant fluid, after flowing through and then out
of the engine 7, discharges the heat at the radiator 9, thereby
cooling the engine 7. In many cases in the normal operation mode,
temperature inside the vehicle cabin is increased enough, and thus
there are no problems even though the coolant fluid does not flow
through the heater core 12a.
[0046] According to the aforementioned embodiment, the battery
warm-up apparatus includes the controller 15 which operates the
first three-way valve 13 on the basis of the detected temperature
and which allows the coolant fluid to flow through the heat branch
8b. Accordingly, the on-vehicle battery 4 is warmed up by using the
heat generated by the engine 7 for power generation, and therefore
the warming-up is performed without increasing consumption of the
electric power of the on-vehicle battery 4. Thus, according to the
battery warm-up apparatus of the embodiment, load or stress applied
to the on-vehicle battery 4 is small.
[0047] Specifically, because an amount of the electric power
consumed from the on-vehicle battery 4, that is, the amount of the
electric power deducted from the on-vehicle battery 4, is limited
to a small amount that corresponds to an amount of the electric
power used when the engine 7 starts, the load applied to the
on-vehicle battery 4 may be minimized, which results in an increase
of a cruising range of the vehicle. Further, a small-sized engine
may be used for the engine 7 that drives the power-generation motor
6 because the engine 7 is not used for driving the driving wheels
1FR, 1FL, and therefore the battery warm-up apparatus is provided
in small in size and low in costs.
[0048] Further, because the heater core 12a for the cabin heater 12
is provided on the heat branch 8b, the inside of the vehicle cabin
is heated by using the heat generated by the engine 7 for power
generation, and thus an influence of the usage of the cabin heater
12 on the cruising range of the vehicle is reduced. Further, even
though the cabin heater 12 is activated for heating the vehicle
cabin, an amount of energy which is used for heating the vehicle
cabin is provided by the power-generation motor 6 because the
on-vehicle battery 4 becomes ready to be charged after being warmed
up. Further, the electric charge into the on-vehicle battery 4 may
be performed at an amount of heat left after deducting the amount
of energy used by the cabin heater 12. In other words, by using the
amount of heat after deducting the amount of energy used by the
cabin heater 12 from the heat generated by the engine 7, the
on-vehicle battery 4 may be warmed up to be ready for being charged
with electricity.
[0049] The controller 15 operates the second three-way valve 14 on
the basis of the detected temperature of the on-vehicle battery 4
or the detected temperature of the engine 7 so that the controller
15 stops the coolant fluid from flowing to the radiator 9, thereby
regulating the temperature of the coolant fluid on the basis of the
temperature of the on-vehicle battery 4 or the temperature of the
engine 7.
[0050] Further, in a case where the temperature of the engine 7 is
less than the engine operation lower-limit temperature Tsc1, which
is predetermined, or in a case where the temperature of the engine
7 is equal to or less than the engine operation lower-limit
temperature Tsc1, the controller 15 actuates or operates the engine
7, disconnects the heat branch 8b from the coolant pipe line 8a by
means of the first three-way valve 13, and disconnects the radiator
9 from the coolant pipe line 8a by means of the second three-way
valve 14. Thus, the controller 15 allows the coolant fluid to
circulate inside the coolant pipe line 8a and the short-cut path
8c, thereby heating the engine 7 and the coolant fluid at an early
stage when the engine 7 is started at low temperatures.
[0051] Further, in a case where the temperature of the engine 7
reaches the engine operation lower-limit temperature Tsc1 or in a
case where the temperature of the engine 7 exceeds the engine
operation lower-limit temperature Tsc1, and at the same time, in a
case where the temperature of the on-vehicle battery 4 is less than
the battery operation lower-limit temperature Tsc2 (the battery
operation lower-limit temperature Tsc2 is higher than the engine
operation lower-limit temperature Tsc1) or in a case where the
temperature of the on-vehicle battery 4 is equal to or less than
the battery operation lower-limit temperature Tsc2, the controller
15 actuates the engine 7, and operates the first three-way valve 13
so that the heat branch 8b is connected to the coolant pipe line
8a. Accordingly, the coolant fluid circulates inside the coolant
pipe line 8a, the heat branch 8b and the short-cut path 8c, and is
supplied to the on-vehicle battery 4. Consequently, in a case where
the temperature of the on-vehicle battery 4 is low after the engine
7 is started, the coolant fluid is supplied to the on-vehicle
battery 4 so that the on-vehicle battery 4 is warmed up.
[0052] Further, in a case where the temperature of the on-vehicle
battery 4 reaches the battery operation lower-limit temperature
Tsc2 or in a case where the temperature of the on-vehicle battery 4
exceeds the battery operation lower-limit temperature Tsc2, the
controller 15 actuates the engine 7, and operates the second
three-way valve 14 so that the short-cut path 8c is disconnected
from the coolant pipe line 8a, and the coolant fluid is allowed to
circulate inside the coolant pipe line 8a and the heat branch 8b,
and thus the coolant fluid is supplied to the on-vehicle battery 4
and to the radiator 9. Accordingly, in a case where the temperature
of the on-vehicle battery 4 increases up to the battery operation
lower-limit temperature Tsc2 due to the warm-up, the coolant fluid
is allowed to flow through the radiator 9, thereby restricting the
on-vehicle battery 4 and the engine 7 from being excessively
heated. Further, the connection and disconnection of the heat
branch 8b relative to the coolant pipe line 8a, and the connection
and disconnection of the radiator 9 relative to the coolant pipe
line 8a are switched, that is, established and disconnected, by
means of the first three-way valve 13 and the second three-way
valve 14 each of which is constituted by the electromagnetic valve.
Accordingly, a temperature status of each component of the vehicle
V is accurately controlled. When the engine temperature T.sub.E and
the battery temperature T.sub.B are compared to the engine
operation lower-limit temperature Tsc1 and to the battery operation
lower-limit temperature Tsc2 in Steps S404 and S406, respectively,
it is determined whether or not the engine temperature T.sub.E and
the battery temperature T.sub.B are less than the engine operation
lower-limit temperature Tsc1 and the battery operation lower-limit
temperature Tsc2, respectively. However, it may be determined
whether or not the engine temperature T.sub.E and the battery
temperature T.sub.B are equal to or less than the engine operation
lower-limit temperature Tsc1 and the battery operation lower-limit
temperature Tsc2, respectively so that cases where the engine
temperature T.sub.E and the battery temperature T.sub.B are equal
to the engine operation lower-limit temperature Tsc1 and the
battery operation lower-limit temperature Tsc2, respectively, are
included. Further, in a similar manner to the Steps S404 and S406,
it may be determined whether or not the battery temperature T.sub.B
is equal to or less than the reference upper-limit temperature Tsh
in Step 408.
Other Embodiments
[0053] The aforementioned embodiment is not limited thereto and may
be modified or extended as follows. When the battery warm-up
apparatus is in the engine warm-up mode, in a case where the start
switch of the cabin heater is turned on, the first three-way valve
13 may be switched, that is, may be controlled to be switched so
that the coolant fluid flows into the heater core 12a on the heat
branch 8b. When the battery warm-up apparatus is in the battery
warm-up mode 1 and in a case where the temperature of the engine 7
reaches a predetermined temperature, the mode may move to, that is,
may be controlled to move to the battery warm-up mode 2.
[0054] According to the embodiment, the battery warm-up apparatus
includes the motor generator 2 for driving the driving wheels 1FR
and 1FL, the on-vehicle battery 4 for supplying the electric power
to the motor generator 2, the power-generation motor 6 for charging
the on-vehicle battery 4, the engine 7 for driving the
power-generation motor 6 without driving the driving wheels 1FR and
1FL, the coolant pipe line 8a arranged to pass through inside the
engine 7 and constituting the closed circuit in a manner that the
coolant fluid flows through the inside of the coolant pipe line 8a,
the radiator 9 arranged on the coolant pipe line 8a, the heat
branch 8b branched from the coolant pipe line 8a, arranged to pass
through the on-vehicle battery 4 and connected to the coolant pipe
line 8a again, the first three-way valve 13 arranged at the first
portion of the coolant pipe line 8a, at which the heat branch 8b is
branched from the coolant pipe line 8a, the first three-way valve
13 connecting and disconnecting the heat branch 8b relative to the
coolant pipe line 8a, the battery temperature sensor 4a for
detecting the temperature T.sub.B of the on-vehicle battery 4, and
the controller 15 for operating the first three-way valve 13 on the
basis of the temperature T.sub.B of the on-vehicle battery 4 which
is detected by the battery temperature sensor 4a and for allowing
the coolant fluid to flow through the heat branch 8b.
[0055] According to the above-described structure, the battery
warm-up apparatus includes the controller 15 which operates the
first three-way valve 13 on the basis of the detected temperature
of the on-vehicle battery 4 and which allows the coolant fluid to
flow through the heat branch 8b. Accordingly, the on-vehicle
battery 4 is warmed up by using the heat generated by the engine 7
which is for power generation, and therefore the warming-up is
performed without increasing the consumption of the electric power
of the on-vehicle battery 4. Thus, according to the battery warm-up
apparatus of the embodiment, the load or the stress applied to the
on-vehicle battery 4 is small.
[0056] Further, the small-sized engine may be used for the engine 7
that drives the power-generation motor 6, and therefore the battery
warm-up apparatus is provided in small in size and low in costs. In
this disclosure, the warm-up of the on-vehicle battery 4
corresponds to heating of the on-vehicle battery 4, when the
on-vehicle battery 4 is at low temperatures, so that the
temperature T.sub.B of the on-vehicle battery 4 is increased up to
a temperature that allows the on-vehicle battery 4 to be charged
and discharged.
[0057] According to the embodiment, the battery warm-up apparatus
includes the heater core 12a for the cabin heater 12, and the
heater core 12a is arranged on the heat branch 8b.
[0058] According to the above-described structure, because the
heater core 12a for the cabin heater 12 is provided on the heat
branch 8b, the inside of the vehicle cabin is heated by using the
heat generated by the engine 7 that is for power generation.
[0059] According to the embodiment, the engine temperature sensor
7a for detecting the temperature T.sub.E of the engine 7 is
provided at the engine 7, the short-cut path 8c is connected to the
coolant pipe line 8a in a manner that the short-cut path 8c
bypasses the radiator 9, the second three-way valve 14 is arranged
at the second portion of the coolant pipe line 8a, at which the
short-cut path 8c is branched from the coolant pipe line 8a, the
second three-way valve 14 selectively allows the coolant fluid to
flow into the radiator 9 and into the short-cut path 8c, and the
controller 15 operates the second three-way valve 14 on the basis
of the temperature T.sub.B of the on-vehicle battery 4 which is
detected by the battery temperature sensor 4a or on the basis of
the temperature T.sub.E of the engine 7 which is detected by the
engine temperature sensor 7a, and thereby stops the coolant fluid
from flowing to the radiator 9.
[0060] According to the above-described structure, the controller
15 operates the second three-way valve 14 on the basis of the
detected temperature of the on-vehicle battery 4 (the battery
temperature T.sub.B) or the detected temperature of the engine 7
(the battery temperature T.sub.E) so that the controller 15 stops
the coolant fluid from flowing to the radiator 9, thereby
regulating the temperature of the coolant fluid on the basis of the
temperature T.sub.B of the on-vehicle battery 4 or the temperature
T.sub.E of the engine 7.
[0061] According to the embodiment, the controller 15 actuates the
engine 7 thereby disconnecting the heat branch 8b from the coolant
pipe line 8a by means of the first three-way valve 13 and
disconnecting the radiator 9 from the coolant pipe line 8a by means
of the second three-way valve 14, and allows the coolant fluid to
circulate inside the coolant pipe line 8a and the short-cut path 8c
in a case where the temperature T.sub.E of the engine 7 which is
detected by the engine temperature sensor 7a is less than the
engine operation lower-limit temperature Tsc1 which is
predetermined or in a case where the temperature T.sub.E of the
engine 7 which is detected by the engine temperature sensor 7a is
equal to or less than the engine operation lower-limit temperature
Tsc1.
[0062] According to the above-described structure, in a case where
the temperature T.sub.E of the engine 7 is less than the engine
operation lower-limit temperature Tsc1, or in a case where the
temperature T.sub.E of the engine 7 is equal to or less than the
engine operation lower-limit temperature Tsc1, the controller 15
actuates the engine 7, disconnects t the heat branch 8b from the
coolant pipe line 8a by means of the first three-way valve 13, and
disconnects the radiator 9 from the coolant pipe line 8a by means
of the second three-way valve 14. Thus, the controller 15 allows
the coolant fluid to circulate inside the coolant pipe line 8a and
the short-cut path 8c, thereby heating the engine 7 and the coolant
fluid at the early stage when the engine 7 is started at low
temperatures.
[0063] According to the embodiment, the controller 15 actuates the
engine 7, operates the first three-way valve 13 thereby connecting
the heat branch 8b to the coolant pipe line 8a, and allows the
coolant fluid to circulate inside the coolant pipe line 8a, the
heat branch 8b and the short-cut path 8c and to be supplied to the
on-vehicle battery 4 in a case where the temperature T.sub.E of the
engine 7 which is detected by the engine temperature sensor 7a
reaches the engine operation lower-limit temperature Tsc1 or in a
case where the temperature of the engine 7 which is detected by the
engine temperature sensor 7a exceeds the engine operation
lower-limit temperature Tsc1, and in a case where the temperature
of the on-vehicle battery 4 is less than the battery operation
lower-limit temperature Tsc2, which is higher than the engine
operation lower-limit temperature Tsc1, or in a case where the
temperature of the on-vehicle battery 4 is equal to or less than
the battery operation lower-limit temperature Tsc2.
[0064] According to the above-described structure, in a case where
the temperature of the engine 7 reaches the engine operation
lower-limit temperature Tsc1 or in a case where the temperature of
the engine 7 exceeds the engine operation lower-limit temperature
Tsc1, and in a case where the temperature of the on-vehicle battery
4 is less than the battery operation lower-limit temperature Tsc2
or in a case where the temperature of the on-vehicle battery 4 is
equal to or less than the battery operation lower-limit temperature
Tsc2 (the battery operation lower-limit temperature Tsc2 is higher
than the engine operation lower-limit temperature Tsc1), the
controller 15 actuates the engine 7 and the first three-way valve
13. Thus, the heat branch 8b is connected to the coolant pipe line
8a so that the coolant fluid circulates inside the coolant pipe
line 8a, the heat branch 8b and the short-cut path 8c, and is
supplied to the on-vehicle battery 4. Accordingly, in a case where
the temperature of the on-vehicle battery 4 is low after the engine
7 is started, the coolant fluid is supplied to the on-vehicle
battery 4 so that the on-vehicle battery 4 is warmed up.
[0065] According to the embodiment, the controller 15 actuates the
engine 7, operates the second three-way valve 14 thereby
disconnecting the short-cut path 8c from the coolant pipe line 8a,
and allows the coolant fluid to circulate inside the coolant pipe
line 8a and the heat branch 8b and to be supplied to the on-vehicle
battery 4 and to the radiator 9 in a case where the temperature of
the on-vehicle battery 4 which is detected by the battery
temperature sensor 4a reaches the battery operation lower-limit
temperature Tsc2 or in a case where the temperature of the
on-vehicle battery 4 which is detected by the battery temperature
sensor 4a exceeds the battery operation lower-limit temperature
Tsc2.
[0066] According to the above-described structure, in a case where
the temperature of the on-vehicle battery 4 reaches the battery
operation lower-limit temperature Tsc2 or in a case where the
temperature of the on-vehicle battery 4 exceeds the battery
operation lower-limit temperature Tsc2, the controller 15 actuates
the engine 7, and operates the second three-way valve 14 so that
the short-cut path 8c is disconnected from the coolant pipe line
8a, and the coolant fluid is allowed to circulate inside the
coolant pipe line 8a and the heat branch 8b, and thus the coolant
fluid is supplied to the on-vehicle battery 4 and to the radiator
9. Accordingly, in a case where the temperature of the on-vehicle
battery 4 increases up to the battery operation lower-limit
temperature Tsc2 due to the warm-up, the coolant fluid flows
through the radiator 9, thereby restricting the on-vehicle battery
4 and the engine 7 from being excessively heated.
[0067] According to the embodiment, the method of warming up the
battery for the vehicle V including the motor generator 2 for
driving the driving wheels 1FR and 1FL, the on-vehicle battery 4
for supplying the electric power to the motor generator 2, the
power-generation motor 6 for charging the on-vehicle battery 4, the
engine 7 for driving the power-generation motor 6 without driving
the driving wheels 1FR and 1FL, the coolant pipe line 8a arranged
to pass through inside the engine 7 and constituting the closed
circuit in a manner that the coolant fluid flows through the inside
of the coolant pipe line 8a, the radiator 9 arranged on the coolant
pipe line 8a, the heat branch 8b branched from the coolant pipe
line 8a, arranged to pass through the on-vehicle battery 4 and
connected to the coolant pipe line 8a again, the first three-way
valve 13 arranged at the first portion of the coolant pipe line 8a,
at which the heat branch 8b is branched from the coolant pipe line
8a, the first three-way valve 13 connecting and disconnecting the
heat branch 8b relative to the coolant pipe line 8a, and the
battery temperature sensor 4a for detecting the temperature T.sub.B
of the on-vehicle battery 4 includes the steps of operating the
first three-way valve 13 on the basis of the temperature T.sub.B of
the on-vehicle battery 4 which is detected by the battery
temperature sensor 4a and allowing the coolant fluid to flow
through the heat branch 8b (Step S407, Step S409).
[0068] Accordingly, the first three-way valve 13 is operated on the
basis of the detected temperature of the on-vehicle battery 4, and
the coolant fluid is allowed to flow through the heat branch 8b.
Accordingly, the on-vehicle battery 4 is warmed up by using the
heat generated by the engine 7 for power generation, and therefore
the warming-up of the on-vehicle battery 4 is performed without
increasing the consumption of the electric power of the on-vehicle
battery 4. Consequently, the load or the stress applied to the
on-vehicle battery 4 is small. In addition, the small-sized engine
may be used for the engine 7 that drives the power-generation motor
6, and therefore the battery warm-up apparatus is provided in small
in size and low in costs.
[0069] The principles, preferred embodiment and mode of operation
of the present invention have been described in the foregoing
specification. However, the invention which is intended to be
protected is not to be construed as limited to the particular
embodiments disclosed. Further, the embodiments described herein
are to be regarded as illustrative rather than restrictive.
Variations and changes may be made by others, and equivalents
employed, without departing from the spirit of the present
invention. Accordingly, it is expressly intended that all such
variations, changes and equivalents which fall within the spirit
and scope of the present invention as defined in the claims, be
embraced thereby.
* * * * *