U.S. patent application number 13/388929 was filed with the patent office on 2012-06-28 for cooling system for electric vehicle.
This patent application is currently assigned to Hitachi, Ltd.. Invention is credited to Yuto Imanishi, Tadashi Osaka, Sachio Sekiya.
Application Number | 20120159986 13/388929 |
Document ID | / |
Family ID | 44066177 |
Filed Date | 2012-06-28 |
United States Patent
Application |
20120159986 |
Kind Code |
A1 |
Imanishi; Yuto ; et
al. |
June 28, 2012 |
Cooling System for Electric Vehicle
Abstract
A cooling system for an electric vehicle, includes: a
cooling-medium circulation passage through which a cooling medium
circulates to travel to heat exchange target objects mounted in a
vehicle that is electrically driven; an electric compressor
disposed in the cooling-medium circulation passage to compress the
cooling medium; and a heat exchange unit that achieves heat
exchange between the cooling medium and outside air, wherein: the
electric compressor is disposed at a position outside a primary
outflow path through which the outside air, having undergone heat
exchange at the heat exchange unit, flows from the heat exchange
unit to outside the vehicle.
Inventors: |
Imanishi; Yuto;
(Hitachinaka-shi, JP) ; Osaka; Tadashi;
(Kashiwa-shi, JP) ; Sekiya; Sachio;
(Hitachinaka-shi, JP) |
Assignee: |
Hitachi, Ltd.
Tokyo
JP
|
Family ID: |
44066177 |
Appl. No.: |
13/388929 |
Filed: |
August 24, 2010 |
PCT Filed: |
August 24, 2010 |
PCT NO: |
PCT/JP2010/064278 |
371 Date: |
March 19, 2012 |
Current U.S.
Class: |
62/498 |
Current CPC
Class: |
B60L 2200/26 20130101;
F01P 2050/24 20130101; Y02T 90/16 20130101; Y02T 10/7291 20130101;
B60L 1/003 20130101; Y02T 10/72 20130101; B60L 2260/56 20130101;
B60L 2240/662 20130101 |
Class at
Publication: |
62/498 |
International
Class: |
F25B 1/00 20060101
F25B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2009 |
JP |
2009-272306 |
Claims
1. A cooling system for an electric vehicle, comprising: a
cooling-medium circulation passage through which a cooling medium
circulates to travel to heat exchange target objects mounted in a
vehicle that is electrically driven; an electric compressor
disposed in the cooling-medium circulation passage to compress the
cooling medium; and a heat exchange unit that achieves heat
exchange between the cooling medium and outside air, wherein: the
electric compressor is disposed at a position outside a primary
outflow path through which the outside air, having undergone heat
exchange at the heat exchange unit, flows from the heat exchange
unit to outside the vehicle.
2. A cooling system for an electric vehicle, comprising: a
cooling-medium circulation passage through which a cooling medium
circulates to travel to heat exchange target objects mounted in a
vehicle that is electrically driven; an electric compressor
disposed in the cooling-medium circulation passage to compress the
cooling medium; a heat exchange unit that achieves heat exchange
between the cooling medium and outside air; and another
cooling-medium circulation passage different from the
cooling-medium circulation passage, through which another cooling
medium, different from the cooling medium, circulates to travel to
electric drive devices including a motor and an inverter power
source, wherein: the heat exchange target objects include a middle
heat exchange unit that achieves heat exchange between the cooling
medium and the other cooling medium; and the middle heat exchange
unit is disposed at a position outside a primary outflow path
through which the outside air, having undergone heat exchange at
the heat exchange unit, flows from the heat exchange unit to
outside the vehicle.
3. A cooling system for an electric vehicle according to claim 1,
further comprising: another cooling-medium circulation passage,
different from the cooling-medium circulation passage, through
which another cooling medium, different from the cooling medium,
circulates to travel to electric drive devices including a motor
and an inverter power source, wherein: the heat exchange target
objects include a middle heat exchange unit that achieves heat
exchange between the cooling medium and the other cooling medium;
and the middle heat exchange unit is disposed at a position outside
the primary outflow path.
4. A cooling system for an electric vehicle according to claim 1,
wherein: the cooling-medium circulation passage in a first assembly
preassembled prior to installation in the electric vehicle, which
includes at least the heat exchange unit, and the cooling-medium
circulation passage in a second assembly preassembled prior to
installation in the electric vehicle, which includes at least some
of the heat exchange target objects, are connected via a coupling
so as to allow the cooling-medium circulation passage in the first
assembly and the cooling-medium circulation passage in the second
assembly, extending frontward and rearward relative to the
coupling, to be connected with each other or disconnected from each
other via the coupling.
5. A cooling system for an electric vehicle, comprising: a
cooling-medium circulation passage through which a cooling medium
circulates to travel to heat exchange target objects mounted in a
vehicle that is electrically driven; an electric compressor
disposed in the cooling-medium circulation passage to compress the
cooling medium; and a heat exchange unit that achieves heat
exchange between the cooling medium and outside air, wherein: the
cooling-medium circulation passage in a first assembly preassembled
prior to installation in the electric vehicle, which includes at
least the heat exchange unit, and the cooling-medium circulation
passage in a second assembly preassembled prior to installation in
the electric vehicle, which includes at least some of the heat
exchange target objects, are connected via a coupling so as to
allow the cooling-medium circulation passage in the first assembly
and the cooling-medium circulation passage in the second assembly
to be connected with each other or disconnected from each other at
a frontward position and a rearward position of the coupling.
6. A cooling system for an electric vehicle according to claim 5,
wherein: the coupling includes a first coupling via which the
cooling medium flows from the first assembly toward the second
assembly and a second coupling via which the cooling medium flows
from the second assembly toward the first assembly, and the first
coupling and the second coupling are both disposed either on an
upper side or a lower side of the vehicle.
7. A cooling system for an electric vehicle according to claim 5,
wherein: the second assembly includes a plurality of the heat
exchange target objects, with a heat exchange target object having
a low temperature upper limit, among the plurality of heat exchange
target objects, is disposed further upstream of cooling medium flow
relative to a heat exchange target object having a high temperature
upper limit.
8. A cooling system for an electric vehicle installed in a vehicle
electrically driven by electric drive devices and used to cool the
electric drive devices, comprising: a heat exchange unit that
achieves heat exchange between a cooling medium and outside air; a
cooling-medium circulation passage through which cooling medium
circulates; an electric compressor disposed in the cooling-medium
circulation passage to compress the cooling medium; another
cooling-medium circulation passage, different from the
cooling-medium circulation passage, through which another cooling
medium, different from the cooling medium, circulates to travel to
the electric drive devices including a motor and an inverter power
source; a middle heat exchange unit that achieves heat exchange
between the cooling medium and the other cooling medium, wherein:
there is provided a first assembly preassembled prior to
installation in the electric vehicle, which includes at least the
heat exchange unit; there is provided a second assembly
preassembled prior to installation in the electric vehicle, which
includes at least the electric compressor and the middle heat
exchange unit; and there is provided a third assembly preassembled
prior to installation in the electric vehicle, which includes at
least the electric drive devices; the cooling-medium circulation
passage in the first assembly and the cooling-medium circulation
passage in the second assembly are connected via a coupling so as
to allow the cooling-medium circulation passage in the first
assembly and the cooling-medium circulation passage in the second
assembly to be connected with each other or disconnected from each
other at a frontward position and a rearward position of the
coupling; and the other cooling-medium circulation passage in the
second assembly and the other cooling-medium circulation passage in
the third assembly are connected via a coupling so as to allow the
other circulation passage in the second assembly and the other
circulation passage in the third assembly to be connected with each
other or disconnected from each other at a frontward position and a
rearward position of this coupling.
9. A cooling system for an electric vehicle installed in a vehicle
electrically driven by electric drive devices and used to cool the
electric drive devices, comprising: a heat exchange unit that
achieves heat exchange between a cooling medium and outside air; a
cooling-medium circulation passage through which the cooling medium
circulates; an electric compressor disposed in the cooling-medium
circulation passage to compress the cooling medium; another
cooling-medium circulation passage, different from the
cooling-medium circulation passage, through which another cooling
medium, different from the cooling medium, circulates to travel to
electric drive devices including a motor and an inverter power
source; and a middle heat exchange unit that achieves heat exchange
between the cooling medium and the other cooling medium, wherein:
there is provided a first assembly preassembled prior to
installation in the electric vehicle, which includes at least the
heat exchange unit, the electric compressor and the middle heat
exchange unit; there is provided a second assembly preassembled
prior to installation in the electric vehicle, which includes at
least the electric drive devices; the other cooling-medium
circulation passage in the first assembly and the other
cooling-medium circulation passage in the second assembly are
connected via a coupling so as to allow the other cooling-medium
circulation passage in the first assembly and the other
cooling-medium circulation passage in the second assembly to be
connected with each other or disconnected from each other at a
frontward position and a rearward position of the coupling.
Description
TECHNICAL FIELD
[0001] The present invention relates to a cooling system for an
electric vehicle.
BACKGROUND ART
[0002] An electric vehicle cooling system known in the related art
may be used to cool a motor that drives a hybrid vehicle and an
inverter power source (see, for instance, patent literature 1).
CITATION LIST
Patent Literature
[0003] Patent literature 1: Japanese Laid Open Patent Publication
No. H11-285106
SUMMARY OF THE INVENTION
Technical Problem
[0004] The patent literature cited above does not disclose any
specific positions at which the components of the electric vehicle
cooling system may be disposed so as to maximize the efficiency of
the cooling system. However, since the positions of these
components may greatly affect the efficiency of the cooling system,
it is crucial that they be disposed in an optimal positional
arrangement.
Solution to Problem
[0005] According to the 1st aspect of the present invention, a
cooling system for an electric vehicle, comprises: a cooling-medium
circulation passage through which a cooling medium circulates to
travel to heat exchange target objects mounted in a vehicle that is
electrically driven; an electric compressor disposed in the
cooling-medium circulation passage to compress the cooling medium;
and a heat exchange unit that achieves heat exchange between the
cooling medium and outside air, wherein: the electric compressor is
disposed at a position outside a primary outflow path through which
the outside air, having undergone heat exchange at the heat
exchange unit, flows from the heat exchange unit to outside the
vehicle.
[0006] According to the 2nd aspect of the present invention, a
cooling system for an electric vehicle, comprises: a cooling-medium
circulation passage through which a cooling medium circulates to
travel to heat exchange target objects mounted in a vehicle that is
electrically driven; an electric compressor disposed in the
cooling-medium circulation passage to compress the cooling medium;
a heat exchange unit that achieves heat exchange between the
cooling medium and outside air; and another cooling-medium
circulation passage different from the cooling-medium circulation
passage, through which another cooling medium, different from the
cooling medium, circulates to travel to electric drive devices
including a motor and an inverter power source, wherein: the heat
exchange target objects include a middle heat exchange unit that
achieves heat exchange between the cooling medium and the other
cooling medium; and the middle heat exchange unit is disposed at a
position outside a primary outflow path through which the outside
air, having undergone heat exchange at the heat exchange unit,
flows from the heat exchange unit to outside the vehicle.
[0007] According to the 3rd aspect of the present invention, in the
cooling system for an electric vehicle according to the 1st aspect,
it is preferred that: the cooling system further comprises another
cooling-medium circulation passage, different from the
cooling-medium circulation passage, through which another cooling
medium, different from the cooling medium, circulates to travel to
electric drive devices including a motor and an inverter power
source; the heat exchange target objects include a middle heat
exchange unit that achieves heat exchange between the cooling
medium and the other cooling medium; and the middle heat exchange
unit is disposed at a position outside the primary outflow
path.
[0008] According to the 4th aspect of the present invention, in the
cooling system for an electric vehicle according to any one of the
1st through 3rd aspects, it is preferred that the cooling-medium
circulation passage in a first assembly preassembled prior to
installation in the electric vehicle, which includes at least the
heat exchange unit, and the cooling-medium circulation passage in a
second assembly preassembled prior to installation in the electric
vehicle, which includes at least some of the heat exchange target
objects, are connected via a coupling so as to allow the
cooling-medium circulation passage in the first assembly and the
cooling-medium circulation passage in the second assembly,
extending frontward and rearward relative to the coupling, to be
connected with each other or disconnected from each other via the
coupling.
[0009] According to the 5th aspect of the present invention, a
cooling system for an electric vehicle, comprises: a cooling-medium
circulation passage through which a cooling medium circulates to
travel to heat exchange target objects mounted in a vehicle that is
electrically driven; an electric compressor disposed in the
cooling-medium circulation passage to compress the cooling medium;
and a heat exchange unit that achieves heat exchange between the
cooling medium and outside air, wherein: the cooling-medium
circulation passage in a first assembly preassembled prior to
installation in the electric vehicle, which includes at least the
heat exchange unit, and the cooling-medium circulation passage in a
second assembly preassembled prior to installation in the electric
vehicle, which includes at least some of the heat exchange target
objects, are connected via a coupling so as to allow the
cooling-medium circulation passage in the first assembly and the
cooling-medium circulation passage in the second assembly to be
connected with each other or disconnected from each other at a
frontward position and a rearward position of the coupling.
[0010] According to the 6th aspect of the present invention, in the
cooling system for an electric vehicle according to the 5th aspect,
it is preferred that the coupling includes a first coupling via
which the cooling medium flows from the first assembly toward the
second assembly and a second coupling via which the cooling medium
flows from the second assembly toward the first assembly, and the
first coupling and the second coupling are both disposed either on
an upper side or a lower side of the vehicle.
[0011] According to the 7th aspect of the present invention, in the
cooling system for an electric vehicle according to the 5th or 6th
aspect, it is preferred that the second assembly includes a
plurality of the heat exchange target objects, with a heat exchange
target object having a low temperature upper limit, among the
plurality of heat exchange target objects, is disposed further
upstream of cooling medium flow relative to a heat exchange target
object having a high temperature upper limit.
[0012] According to the 8th aspect of the present invention, a
cooling system for an electric vehicle installed in a vehicle
electrically driven by electric drive devices and used to cool the
electric drive devices, comprises: a heat exchange unit that
achieves heat exchange between a cooling medium and outside air; a
cooling-medium circulation passage through which cooling medium
circulates; an electric compressor disposed in the cooling-medium
circulation passage to compress the cooling medium; another
cooling-medium circulation passage, different from the
cooling-medium circulation passage, through which another cooling
medium, different from the cooling medium, circulates to travel to
the electric drive devices including a motor and an inverter power
source; a middle heat exchange unit that achieves heat exchange
between the cooling medium and the other cooling medium, wherein:
there is provided a first assembly preassembled prior to
installation in the electric vehicle, which includes at least the
heat exchange unit; there is provided a second assembly
preassembled prior to installation in the electric vehicle, which
includes at least the electric compressor and the middle heat
exchange unit; and there is provided a third assembly preassembled
prior to installation in the electric vehicle, which includes at
least the electric drive devices; the cooling-medium circulation
passage in the first assembly and the cooling-medium circulation
passage in the second assembly are connected via a coupling so as
to allow the cooling-medium circulation passage in the first
assembly and the cooling-medium circulation passage in the second
assembly to be connected with each other or disconnected from each
other at a frontward position and a rearward position of the
coupling; and the other cooling-medium circulation passage in the
second assembly and the other cooling-medium circulation passage in
the third assembly are connected via a coupling so as to allow the
other circulation passage in the second assembly and the other
circulation passage in the third assembly to be connected with each
other or disconnected from each other at a frontward position and a
rearward position of this coupling.
[0013] According to the 9th aspect of the present invention, a
cooling system for an electric vehicle installed in a vehicle
electrically driven by electric drive devices and used to cool the
electric drive devices, comprises: a heat exchange unit that
achieves heat exchange between a cooling medium and outside air; a
cooling-medium circulation passage through which the cooling medium
circulates; an electric compressor disposed in the cooling-medium
circulation passage to compress the cooling medium; another
cooling-medium circulation passage, different from the
cooling-medium circulation passage, through which another cooling
medium, different from the cooling medium, circulates to travel to
electric drive devices including a motor and an inverter power
source; and a middle heat exchange unit that achieves heat exchange
between the cooling medium and the other cooling medium, wherein:
there is provided a first assembly preassembled prior to
installation in the electric vehicle, which includes at least the
heat exchange unit, the electric compressor and the middle heat
exchange unit; there is provided a second assembly preassembled
prior to installation in the electric vehicle, which includes at
least the electric drive devices; the other cooling-medium
circulation passage in the first assembly and the other
cooling-medium circulation passage in the second assembly are
connected via a coupling so as to allow the other cooling-medium
circulation passage in the first assembly and the other
cooling-medium circulation passage in the second assembly to be
connected with each other or disconnected from each other at a
frontward position and a rearward position of the coupling.
Advantageous Effect of the Invention
[0014] The present invention improves the cooling efficiency of a
cooling system installed in an electric vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] (FIG. 1) A diagram showing the configuration of a cooling
system for an electric vehicle adopting the present invention
[0016] (FIG. 2) A schematic view of a vehicle with the electric
vehicle cooling system adopting the present invention installed
therein, taken from the front
[0017] (FIG. 3) A schematic top view of the front side of the
vehicle
[0018] (FIG. 4) A schematic view of the electric vehicle cooling
system installed in a vehicle, taken from a position diagonally to
the front of the vehicle
[0019] (FIG. 5) A diagram showing how the electric vehicle cooling
system assemblies may be systematized
[0020] (FIG. 6) An example of a positional arrangement with the
inverter power source 2 disposed under the motor 1
[0021] (FIG. 7) A diagram pertaining to a variation
[0022] (FIG. 8) A diagram pertaining to a variation
[0023] (FIG. 9) A diagram pertaining to a variation
[0024] (FIG. 10) A diagram pertaining to a variation
[0025] (FIG. 11) A diagram pertaining to a variation
[0026] (FIG. 12) A diagram showing the structure of the drive
system in an electric vehicle adopting the heat cycle system
according to the present invention and the electrical connections
among the various components in the electric machine drive system
constituting part of the drive system
DESCRIPTION OF EMBODIMENT
[0027] The following is a description of an embodiment of the
present invention. In the following description of the embodiment,
the present invention is adopted in a heat cycle system of a pure
electric vehicle that uses an electric motor as its sole drive
source.
[0028] The structure achieved in the embodiment described below may
be adopted in a heat cycle system of an electric vehicle that uses
both an internal combustion engine and an electric motor as vehicle
drive sources, such as a hybrid vehicle (passenger vehicle), a
freight vehicle such as a hybrid truck or a public transportation
vehicle such as a hybrid bus.
[0029] First, in reference to FIG. 12, the electric machine drive
system of a pure electric vehicle (hereafter simply referred to as
an "EV") adopting the heat cycle system according to the present
invention is described.
[0030] FIG. 12 shows the structure of the drive system in an EV
1000 and the electrical connections among the various components of
the electric machine (motor/generator) drive system constituting
part of the drive system.
[0031] It is to be noted that the high-power system is indicated
with bold solid lines, whereas the low-power system is indicated
with thin solid lines in FIG. 12.
[0032] An axle 820 is axially supported so as to be allowed to
rotate freely at a front part or a rear part of the vehicle body
(not shown). A pair of drive wheels 800 are disposed each at one of
the two ends of the axle 820. In addition, an axle with a pair of
non-drive wheels disposed at the two ends thereof is axially
supported so as to be allowed to rotate freely at the rear part or
the front part of the body (not shown). While the EV 1000 shown in
FIG. 12 is a front wheel drive vehicle with the drive wheels 800
disposed toward the front and the non-drive wheels disposed toward
the rear, the present invention may be adopted in a rear wheel
drive EV with the drive wheels 800 disposed toward the rear and the
non-drive wheels disposed toward the front of the vehicle.
[0033] A differential gear (hereafter referred to as a "DEF") 830
is disposed at a central area of the axle 820. The axle 820 is
mechanically connected to the output side of the DEF 830. An output
shaft of a transmission 810 is mechanically connected to the input
side of the DEF 830. The DEF 830 is a differential motive power
distribution mechanism that distributes the rotational drive force,
the speed of which is altered at the transmission 810 and is then
transmitted from the transmission 810, to the left and right sides
of the axle 820. The output side of a motor generator 200 is
mechanically connected to the input side of the transmission
810.
[0034] The motor generator 200 is a rotating electrical machine
equipped with an armature (equivalent to the stator in the EV 1000
shown in FIG. 12) 210 with an armature winding 211 disposed thereat
and a magnetic field (equivalent to the rotor in the EV 1000 shown
in FIG. 12) 220 with permanent magnets 221 disposed thereat, which
is disposed so as to face opposite the armature 210 via an air gap.
The motor generator 200 functions as a motor when the EV 1000 is
engaged in power running operation, whereas it functions as a
generator during regenerative operation.
[0035] When the motor generator 200 functions as a motor, the
electric energy accumulated in a battery 100 is supplied to the
armature winding 211 via an inverter device 300. As a result, the
motor generator 200 generates rotational motive power (mechanical
energy) through magnetic action occurring between the armature 210
and the magnetic field 220. The rotational motive power output from
the motor generator 200 is transmitted to the axle 820 via the
transmission 810 and the DEF 830 and the drive wheels 800 are thus
driven with the rotational motive power.
[0036] When the motor generator 200 functions as a generator, the
mechanical energy (rotational motive power) transmitted from the
drive wheels 800 is transmitted to the motor generator 200 so as to
drive the motor generator 200. As the motor generator 200 is
driven, interlinkage of the magnetic flux from the magnetic field
200 with the armature winding 211 occurs, thereby inducing a
voltage. The motor generator 200 generates electric power through
this process. The electric power output from the motor generator
200 is provided to the battery 100 via the inverter device 300. The
battery 100 becomes charged with the power thus provided.
[0037] The temperature of the motor generator 200, or more
specifically, the temperature of the armature 210, is adjusted via
a heat cycle system, which is to be described later, so that the
temperature remains within an allowable temperature range. While
the armature 210, which is a heat generating component, needs to be
cooled, it may require warming-up when the ambient temperature is
low, in order to assure predetermined electrical
characteristics.
[0038] The motor generator 200 is driven with the inverter device
300 controlling the electric power between the armature 210 and the
battery 100. In other words, the inverter device 300 functions as a
control device for the motor generator 200. The inverter device 300
is a power conversion device that converts DC power to AC power or
AC power to DC power through switching operation of switching
semiconductor elements. It includes a power module 310, a drive
circuit 330 that drives the switching semiconductor elements
mounted at the power module 310, an electrolytic capacitor 320 that
is electrically connected in parallel to the DC side of the power
module 310 and smooths a DC voltage, and a motor control device 340
that generates a switching command for the switching semiconductor
elements at the power module 310 and outputs a signal corresponding
to the switching command to the drive circuit 330.
[0039] The power module 310 is a structural unit achieved by
mounting six switching semiconductor elements on a substrate and
electrically connecting the six switching semiconductor elements
through a connecting conductor such as an aluminum wire so as to
configure a power conversion circuit constituted with three serial
circuits each corresponding to one of three phases and made up with
two switching semiconductor elements (an upper arm switching
semiconductor element and a lower arm switching semiconductor
element) electrically connected with each other in series, which
are electrically connected in parallel (in a three-phase bridge
connection).
[0040] The switching semiconductor elements may be metal oxide film
semiconductor field effect transistors (MOSFETs) or insulated
gate-type bipolar transistors (IGBTs). A power conversion circuit
constituted with MOSFETs does not require an additional diode
element to be mounted between the drain electrode and the source
electrode of each semiconductor element, since a parasitic diode is
present between the drain electrode and the source electrode.
However, a power conversion circuit constituted with IGBTs requires
an additional diode element to be electrically connected in
anti-parallel between the collector electrode and the emitter
electrode of each IGBT, since no diode element is present between
the collector electrode and the emitter electrode.
[0041] The side of each upper arm opposite from the side where it
is connected with the lower arm (the collector electrode side in an
IGBT) is led out through the DC side of the power module 310 and is
electrically connected to the positive pole side of the battery
100. The side of each lower arm opposite from the side where it is
connected with the upper arm (the emitter electrode side in an
IGBT) is led out through the DC side of the power module 310 and is
electrically connected to the negative pole side of the battery
100. The midpoint between each pair of arms, i.e., the connecting
point at which the side of the upper arm where it connects with the
lower arm (the emitter electrode side of the upper arm constituted
with an IGBT) and the side of the lower arm where it connects with
the upper arm (the collector electrode side of the lower arm
constituted with an IGBT) are connected with each other, is led out
through the AC side of the power module 310 and is electrically
connected to the winding of the corresponding phase in the armature
winding 211.
[0042] The electrolytic capacitor 320 is a smoothing capacitor that
eliminates an AC component contained in the DC component so as to
prevent voltage fluctuation attributable to high-speed switching
operation of the switching semiconductor elements and the parasitic
inductance in the power conversion circuit. As an alternative to
the electrolytic capacitor 320, a film capacitor may be utilized as
the smoothing capacitor.
[0043] The motor control device 340 is an electronic circuit device
that generates a switching command signal (e.g., a PWM (pulse width
modulation) signal) for the six switching semiconductor elements in
response to a torque command signal output from a vehicle control
device 840 which executes overall control for the vehicle and
outputs the switching command signal thus generated to the drive
circuit 330.
[0044] The drive circuit 330 is an electronic circuit device that
generates a drive signal for the six switching semiconductor
elements upon receiving the switching command signal output from
the motor control device 340 and outputs the drive signal thus
generated to the gate electrodes of the six switching semiconductor
elements.
[0045] The temperature at the inverter device or, more
specifically, the temperatures at the power module 310 and the
electrolytic capacitor 320 are adjusted via the heat cycle system
to be described in detail later, so that the temperatures remain
within an allowable temperature range. While the power module 310
and the electrolytic capacitor 320, which are heat generating
components, need to be cooled, they may sometimes need warming-up,
particularly when the ambient temperature is low, in order to
assure predetermined operational characteristics and electrical
characteristics.
[0046] Based upon a plurality of condition parameters indicating
the vehicle operating conditions, such as a torque request from the
driver (indicated by the extent to which the accelerator pedal is
operated or the throttle opening degree) and the vehicle speed, the
vehicle control device 840 generates a motor torque command signal
for the motor control device 340 and outputs the motor torque
command signal to the motor control device 340.
[0047] The battery 100 is a power source that provides power used
to drive the motor generator 200. It is a high-voltage power source
with a nominal output voltage of 200 V or higher and is
electrically connected to the inverter device 300 and a charger 500
via a junction box 400. The battery 100 may be a lithium ion
battery.
[0048] It is to be noted that an electric power storage device
other than a lithium ion battery, such as a lead acid battery, a
nickel hydride battery, an electric double-layer capacitor or a
hybrid capacitor, may be used as the battery 100 instead.
[0049] The battery 100 is a power storage device that is charged
and discharged via the inverter device 300 and the charger 500. The
primary components constituting the battery 100 are a battery unit
110 and a control unit.
[0050] The battery unit 110, used as an electric energy storage
area, is constituted with a plurality of lithium ion battery cells,
in which electric energy can be accumulated or from which electric
energy can be released (DC power can be charged/discharged),
electrically connected in series. It is electrically connected to
the inverter device 300 and the charger 500.
[0051] The control unit is an electronic control device constituted
with a plurality of electronic circuit components. It manages and
controls the conditions of the battery unit 110 and also controls
the inflow/outflow of electric energy at the battery unit 110 by
providing an allowable charge/discharge quantity, representing the
extent to which the battery may be charged/discharged, to the
inverter device 300 and the charger 500.
[0052] The electronic control device is configured so as to include
two separate hierarchical functional layers. Namely, it includes a
battery control device 130 designated as a higher order (parent)
controller within the battery 100 and a cell control device 120
designated as a lower order (child) controller relative to the
battery control device 130.
[0053] The cell control device 120 includes a plurality of battery
management means for individually managing and controlling the
states of the plurality of lithium ion battery cells by working as
limbs of the battery control device 130 based upon a command signal
output from the battery control device 130. The plurality of
battery management means are each constituted with an integrated
circuit (IC). The plurality of integrated circuits are each
disposed in correspondence to one of several lithium ion battery
cell groups into which the plurality of lithium ion battery cells
electrically connected in series are divided. Each integrated
circuit individually detects the voltages at the plurality of
lithium ion battery cells belonging to the corresponding group and
any abnormal condition such as an overcharge or an overdischarge
occurring at any of the lithium ion battery cells belonging to the
corresponding group. In addition, it individually manages and
controls the states of the plurality of lithium ion battery cells
in the corresponding group so as to ensure the individual lithium
ion battery cells in the group achieve matching states of charge by
discharging any lithium ion battery cell with an SOC (state of
charge) level higher than a predetermined SOC level whenever the
states of charge in the plurality of lithium ion battery cells in
the particular group are not uniform.
[0054] The battery control device 130 is an electronic control
device that manages and controls the conditions of the battery unit
110 and controls the inflow/outflow of electric energy at the
battery unit 110 by providing an instruction indicating the
allowable charge/discharge quantity to the vehicle control device
840 or the motor control device 340. It is equipped with a
condition detection means. The condition detection means is
constituted with an arithmetic processing device such as a
microcomputer or a digital signal processor.
[0055] A plurality of signals, including measurement signals output
from a current measuring means for measuring the charge/discharge
current at the battery unit 110, a voltage measuring means for
measuring the charge/discharge voltage at the battery unit 110 and
a temperature measuring means for measuring the temperatures at the
battery unit 110 and some lithium ion battery cells, detection
signals pertaining to the terminal voltages at the plurality of
lithium ion batteries, output from the cell control device 120, an
error signal output from the cell control device 120, an ON/OFF
signal output in response to an ignition switch operation and a
signal output from a higher-order control device, i.e., the vehicle
control device 840 or the motor control device 340, are input to
the condition detection means 1 in the battery control device
130.
[0056] Based upon the information carried in the signals input
thereto and a plurality of sets of preset information including
lithium ion battery cell characteristics information and arithmetic
operation information needed when executing arithmetic operation,
the condition detection means in the battery control device 130
executes a plurality of types of arithmetic operations including an
arithmetic operation through which the state of charge (SOC), the
state of health (SOH) and the like at the battery unit 110 are
detected, an arithmetic operation executed to balance the SOCs in
the plurality of lithium ion battery cells and an arithmetic
operation through which the charge/discharge quantity at the
battery unit 110 is controlled. Based upon the results of these
arithmetic operations, the condition detection means in the battery
control device 130 generates a plurality of signals including a
command signal for the cell control device 120, a signal pertaining
to the allowable charge/discharge quantity, which is to be used to
control the charge/discharge quantity at the battery unit 110, a
signal related to the SOC in the battery unit 110 and a signal
related to the SOH in the battery unit 110, and outputs the signals
thus generated.
[0057] In addition, based upon the error signal output from the
cell control device 120, the condition detection means in the
battery control device 130 generates a plurality of signals,
including a command signal carrying an instruction for cutting off
a first positive pole relay 410 and a first negative pole relay 420
and a notification signal used to notify an abnormal condition, and
outputs the signals thus generated.
[0058] While the battery control device 130 and the cell control
device 120 are able to exchange signals with each other through a
signal transmission path, they are electrically insulated from each
other, since they use different operation power sources and operate
on reference potentials different from each other. In order to
assure reliable electrical isolation, an insulator 140, such as a
photocoupler, a capacitive coupling element or a transformer, is
disposed on the signal transmission path connecting the battery
control device 130 with the cell control device 120. Through these
measures, the battery control device 130 and the cell control
device 120 are able to engage in signal transmission with signals
assuming reference potentials different from each other.
[0059] The temperature at the battery 100 or, more specifically,
the temperature at the battery unit 110, is adjusted via the heat
cycle system to be described later so as to ensure that the
temperature remains in an allowable temperature range. While the
battery unit 110, which is a heat generating component, needs to be
cooled, it may require warming-up, particularly when the ambient
temperature is low, in order to assure predetermined input/output
characteristics.
[0060] The electric energy accumulated in the battery 100 is
utilized as drive power to drive the electric machine drive system
that enables the EV 1000 to engage in traveling operation. Electric
energy is accumulated in the battery 100 with regenerative power
generated through regenerative operation of the electric machine
drive system, power taken in from a commercial residential power
source or power purchased at a charging station (an electricity
kiosk).
[0061] The battery 100 is charged through a commercial residential
power source 600 or a power-feed device at an charging station by
connecting a power plug 550 at the front end of a power cable,
which is electrically connected to an external power source
connector terminal of the charger 500, to an outlet 700 located on
the commercial residential power source 600 or by connecting a
power cable extending from the power-feed device at the charging
station to the external power source connector terminal of the
charger 500, so as to electrically connect the charger 500 with the
commercial residential power source 600 or with the power-feed
device at the charging station. Once the electrical connection is
established, AC power is supplied from the commercial residential
power source 600 or the power-feed device at the charging station
to the charger 500. The AC power thus supplied is converted to DC
power at the charger 500, which further adjusts the DC power so as
to provide it as a charge voltage to the battery 100. As a result,
the battery 100 becomes charged.
[0062] It is to be noted that the battery 100 is charged with power
provided via the power-feed device at the charging station in
basically the same manner as that with which the battery 100 is
charged via the commercial residential power source 600. However,
the capacity of the electric current supplied from the power-feed
device at the charging station and the length of time required to
charge the battery 100 with the power supplied from the power-feed
device at the charging station are different from those of the
battery charge via the commercial residential power source 600.
Namely, the battery 100 can be charged in less time via the
power-feed device at the charging station with a higher current
capacity compared to the commercial residential power source
600.
[0063] The charger 500 is a power conversion device that converts
the AC power supplied from the commercial residential power source
600 or the AC power supplied from the power-feed device at the
charging station to DC power, raises the voltage of the DC power
resulting from the conversion to a level required of the charge
voltage for the battery 100 and supplies the charge voltage to the
battery 100. The primary components of the charger 500 include an
AC/DC conversion circuit 510, a voltage booster circuit 520, a
drive circuit 530 and a charge control device 540.
[0064] The AC/DC conversion circuit 510 is a power conversion
circuit that converts the AC power supplied from the external power
source to DC power and outputs the DC power resulting from the
conversion. It may be configured by assembling a plurality of diode
elements through a bridge connection. The AC/DC conversion circuit
510 includes a rectifier circuit used to rectify the AC power
supplied from the external power source to DC power and a power
factor improving circuit electrically connected on the DC side of
the rectifier circuit, through which the power factor of the output
from the rectifier circuit is improved. Alternatively, AC power may
be converted to DC power via a circuit constituted with a plurality
of switching semiconductor elements connected in a bridge
connection with diode elements connected in an anti-parallel
configuration.
[0065] The voltage booster circuit 520 is a power conversion
circuit that boosts the voltage of the DC power output from the
AC/DC conversion circuit 510 (power factor improving circuit) to a
level required of the charge voltage for the battery 100, and may
be constituted with, for instance, an isolated DC/DC converter. An
isolated DC/DC converter comprises a transformer, a conversion
circuit that is electrically connected to a primary winding of the
transformer, is constituted with a plurality of switching
semiconductor elements connected in a bridge connection, converts
the DC power output from the AC/DC conversion circuit 510 to AC
power and inputs the AC power resulting from the conversion to the
primary winding of the transformer, a rectifier circuit that is
electrically connected to a secondary winding of the transformer,
is constituted with a plurality of diode elements connected in a
bridge connection and rectifies AC power generated at the secondary
winding of the transformer to DC power, a smoothing reactor that is
electrically connected in series to the positive pole side of the
output (DC side) of the rectifier circuit and a smoothing capacitor
electrically connected in parallel between the positive electrode
and the negative electrode on the output side (DC side) of the
rectifier circuit.
[0066] The charge control device 540 is an electronic circuit
device that generates a switching command signal, (e.g., a PWM
(pulse width modulation) signal) for the plurality of switching
semiconductor elements in the voltage booster circuit 520 based
upon a signal input thereto from the vehicle control device 840 or
a signal input thereto from a control device in the battery 100 and
outputs the switching command signal thus generated to the drive
circuit 530, so as to control the timing with which a charge of the
battery 100 by the charger 500 ends/starts, and control the power,
the voltage, the current and the like supplied from the charger 500
to the battery 100 during the charge and the like. Such a charge
control device 540 is configured by mounting a plurality of
electronic components including an arithmetic processing device,
e.g., a microcomputer, at a circuit substrate.
[0067] The vehicle control device 840 monitors the voltage on, for
instance, the input side of the charger 500. Upon deciding that the
charger 500 has entered a charge start state with the charger 500
electrically connected to the external power source and a voltage
applied to the input side of the charger 500, the vehicle control
device 840 outputs a charge start command signal to the charge
control device 540 so as to start a charge, whereas upon deciding,
based upon a battery condition signal output from the control
device in the battery 100, that the battery 100 has achieved a
fully charged state, the vehicle control device 840 outputs a
charge end command signal to the charge control device 540 so as to
end the charge. These operations may be executed by the motor
control device 340 or the control device in the battery 100, or
they may be executed by the charge control device 540 in
cooperation with the control device in the battery 100.
[0068] The control device in the battery 100 calculates through
arithmetic operation an allowable charge quantity for the battery
100 by detecting the conditions of the battery 100 and outputs a
signal indicating the arithmetic operation results to the charger
500, so as to control the charge of the battery 100 by the charger
500.
[0069] The drive circuit 530, which is an electronic circuit device
that generates a drive signal for the plurality of switching
semiconductor elements in the voltage booster circuit 520 in
response to the command signal output from the charge control
device 540 and outputs the drive signal to the gate electrodes of
the plurality of switching semiconductor elements, is configured by
mounting a plurality of electronic components, such as a switching
semiconductor element and an amplifier, at a circuit substrate.
[0070] It is to be noted that in a configuration with the AC/DC
conversion circuit 510 constituted with switching semiconductor
elements, the switching operation of the switching semiconductor
elements in the AC/DC conversion circuit 510 is controlled as a
switching command signal for the switching semiconductor elements
in the AC/DC conversion circuit 510 is output from the charge
control device 540 to the drive circuit 530, and a drive signal for
the switching semiconductor elements in the AC/DC conversion
circuit 510 is output from the drive circuit 530 to the gate
electrodes of the switching semiconductor elements in the AC/DC
conversion circuit 510.
[0071] First and second positive pole side relays 410 and 430 and
first and second negative pole side relays 420 and 440 are housed
inside the junction box 400.
[0072] The first positive pole side relay 410 is a switch via which
the electrical connection between the DC positive pole side of the
inverter device 300 (power module 310) and the positive pole side
of the battery 100 is controlled. The first negative pole 1 0 side
relay 420 is a switch via which the electrical connection between
the DC negative pole side of the inverter device 300 (power module
310) and the negative pole side of the battery 100 is controlled.
The second positive pole side relay 430 is a switch via which the
electrical connection between the DC positive pole side of the
charger 500 (voltage booster circuit 520) and the positive pole
side of the battery 100 is controlled. The second negative pole
side relay 440 is a switch via which the electrical connection
between the DC negative pole side of the charger 500 (voltage
booster circuit 520) and the negative pole side of the battery 100
is controlled.
[0073] The first positive pole side relay 410 and the first
negative pole side relay 420 are closed, either in an operation
mode in which rotational motive power from the motor generator 200
is needed or in an operation mode in which power needs to be
generated at the motor generator 200, whereas they are opened when
the vehicle is set in a stop mode (with the ignition switch open),
when a fault has occurred in the electric drive device or in the
vehicle or when the battery 100 is charged with the charger 500.
The second positive pole side relay 430 and the second negative
pole side relay 440, on the other hand, are closed when the battery
100 is charged with the charger 500 and are opened when the
charging of the battery 100 by the charger 500 ends or when a fault
has occurred in the charger 500 or in the battery 100.
[0074] The open/close state at the first positive pole side relay
410 and the first negative pole side relay 420 is controlled with
an open/close command signal output from the vehicle control device
840. However, the open/close state at the first positive pole side
relay 410 and the first negative pole side relay 420 may be
controlled with an open/close command signal output from another
control device such as the motor control device 340 or a control
device in the battery 100. The open/close state at the second
positive pole side relay 430 and the second negative pole side
relay 440 is controlled with an open/close command signal output
from the charge control device 540. However, the open/close state
at the second positive pole side relay 430 and the second negative
pole side relay 440 may be controlled with an open/close command
signal output from another control device such as the vehicle
control device 840 or the control device in the battery 100.
[0075] As described above, the first positive pole side relay 410
and the first negative pole side relay 420 are disposed between the
battery 100 and the inverter device 300 and the second positive
pole side relay 430 and the second negative pole side relay 440 are
disposed between the battery 100 and the charger 500 in the EV 1000
so as to control the electrical connections among the battery 100,
the inverter device 300 and the charger 500. As a result, a high
level of safety is assured for the electric drive device which is a
high-voltage system.
[0076] The following is a description of the heat cycle system
mounted at the EV 1000 as achieved in an embodiment, given in
reference to FIGS. 1 through 6. It is to be noted that as explained
earlier, the specific details described below are applicable to
electrically-operated vehicles such as hybrid vehicles, electric
trains and construction vehicles, as well as pure electric
vehicles. In addition, while the present invention is adopted in
conjunction with an AC motor driven via an inverter power source in
the embodiment described below, the present invention is not
limited to applications in AC motors and it may be adopted in
conjunction with all types of rotating electrical machines (motor
generators) including a DC motor driven via a converter power
source such as a thyristor Leonard device and a pulse motor driven
via a chopper power source.
[0077] FIG. 1 shows the configuration of the cooling system for an
electric vehicle achieved in the embodiment. This electric vehicle
cooling system comprises a first cooling system that releases the
heat in a cooling medium to the outside, and a second cooling
system that cools a traveling drive motor I (equivalent to the
motor generator 200 in FIG. 12) and an inverter power source
(inverter) 2 (equivalent to the inverter device 300 in FIG. 12)
that drives the motor by exchanging heat with the first cooling
system via a middle heat exchanger 8.
[0078] The first cooling system includes a radiator 3, a fan 4, a
cooling-medium circulation passage 6a, an electric compressor
(compressor) 7, the middle heat exchanger 8 and an adjustment valve
9. The cooling medium (refrigerant) circulates through the
cooling-medium circulation passage 6a by traveling on a path
extending from the middle heat exchanger 8 to the compressor 7, the
radiator 3 and the adjustment valve 9 in this order and then
returning to the middle heat exchanger 8. This first cooling system
constitutes a refrigerating cycle in which a refrigerant for
refrigerating cycle such as HFC-134a, is used as a first cooling
medium (refrigerant) and the radiator 3, the adjustment valve 9 and
the middle heat exchanger 8 respectively function as a condenser,
an expansion valve and an evaporator. At the middle heat exchanger
8, the first cooling medium absorbs heat from a second cooling
medium (coolant) in the second cooling system. The first cooling
medium, having absorbed heat from the second cooling medium is then
compressed at the compressor 7, is cooled at the radiator 3 with
air blown by the fan 4 and then travels back to the middle heat
exchanger 8 via the adjustment valve 9. The middle heat exchanger 8
is the heat exchange target object to be cooled in the first
cooling system.
[0079] The second cooling system includes a pump 5, a
cooling-medium circulation passage 6b, the middle heat exchanger 8
and cooling target objects, i.e., the motor 1 and the inverter
power source 2. The second cooling medium circulates through the
cooling-medium circulation passage 6b by traveling on a path
extending from the pump 5 to the middle heat exchanger 8, the
inverter power source 2 and the motor 1 in this order and then
returning to the pump 5. The second cooling medium, force-fed from
the pump 5, undergoes heat exchange at the middle heat exchanger 8
to exchange heat with the cooling medium in the first cooling
system and thus becomes cooled. The second cooling medium then
travels to the inverter power source 2 and the motor 1, thereby
cooling them before traveling back to the pump 5. In the second
cooling system, the motor 1 and the inverter power source 2 are
heat exchange target objects to be cooled.
[0080] In the embodiment, the second cooling medium, having become
cooled through the heat exchange at the middle heat exchanger 8, is
first supplied to the inverter power source 2, and after the
inverter power source 2 is cooled with the second cooling medium,
it is delivered to the motor 1 in this order so as to cool the
motor 1. The temperature of a semiconductor power conversion device
such as the inverter power source 2 with a smaller thermal time
constant compared to that of the motor 1, normally increases
quickly and the allowable temperature upper limit of such a
semiconductor power conversion device is bound to be lower than
that of the motor 1. For this reason, it is desirable to create a
cooling-medium circulation path through which the second cooling
medium first travels to the inverter power source 2 to cool it and
then it travels to the motor 1 to cool the motor 1, as in the
embodiment.
[0081] It is to be noted that although not shown, the motor 1 and
the inverter power source 2 may be connected in parallel to the
cooling-medium circulation passage 6b so as to concurrently
circulate the second cooling medium force-fed from the pump 5
through the motor 1 and the inverter power source 2 via the middle
heat exchanger 8. As a further alternative, a cooling-medium
circulation passage for the motor 1 and a cooling-medium
circulation passage for the inverter power source 2 may be formed
separately with a middle heat exchanger 8 and a pump 5 disposed at
each cooling-medium circulation passage.
[0082] While the motor 1 and the inverter power source 2 are
cooling target objects in the electric vehicle cooling system
achieved in the embodiment, either the motor 1 or the inverter
power source 2 alone may be designated as a cooling target object.
Furthermore, an electricity storage device that exchanges DC power
with the inverter power source 2 may be designated as a cooling
target object in addition to the motor 1 and the inverter power
source 2.
[0083] A control device 23 in FIG. 1, constituted with a CPU 23c, a
memory 23 and the like, controls a fan drive device 21a, a
compressor drive device 21b and a pump drive device 22 and controls
cooling of the motor 1 and the inverter power source 2 by executing
a cooling control program. A vehicle speed sensor 24 that detects
the speed of the vehicle, an accelerator sensor 25 that detects the
degree of accelerator pedal operation and the like are connected to
the control device 23. The control device 23 individually controls
the drive devices based upon signals provided from the various
sensors and the like.
[0084] --Positions at Which the Individual Components are
Disposed--
[0085] The electric vehicle cooling system achieved in the
embodiment by adopting the structure described above is installed
in a vehicle as described below. FIG. 2 is a schematic view of a
vehicle with the electric vehicle cooling system in the embodiment
mounted thereat, taken from the front side, FIG. 3 is a schematic
view of the front side of the vehicle, taken from above and FIG. 4
is a schematic view of the electric vehicle cooling system
installed in the vehicle, taken from a position diagonally to the
front of the vehicle. As shown in FIGS. 2 through 4, the radiator 3
in the electric vehicle cooling system achieved in the embodiment
is disposed on the front side of the vehicle so that outside air
passes through the radiator 3 as it travels from the front side of
the vehicle toward the rear side of the vehicle. In addition, the
compressor 7 and the middle heat exchanger 8 are disposed rearward
relative to the radiator 3 and offset to the left and to the right
of the radiator so that they are not in a primary outflow path
through which air, having passed through the radiator 3, travels to
flow out of the vehicle.
[0086] Since the compressor 7 and the middle heat exchanger 8,
which form large projection areas viewed from the front side of the
vehicle, are not present in the air outflow path through which air,
having passed through the radiator 3 travels, the extent of
pressure loss occurring in the air passing through the radiator 3
is reduced so as to improve the efficiency of the cooling system.
This positional arrangement is also advantageous in that since the
compressor 7 and the middle heat exchanger 8 are outside the air
outflow path and thus are not warmed by the air, having passed
through the radiator 3 and become warmer, the efficiency of the
cooling system is not compromised. It is to be noted that while
only either the compressor 7 or the middle heat exchanger 8 alone
may be disposed outside the outflow path of air having passed
through the radiator 3, it is more desirable to maximize the
cooling system efficiency by disposing both the compressor 7 and
the middle heat exchanger 8 outside the air outflow path of air
having passed through the radiator 3.
[0087] The pump 5 is disposed in the outflow path of air having
passed through the radiator, since the pump 5, forming a small
projection area viewed from the front side of the vehicle, will not
be a significant contributing factor in pressure loss in the air
passing through the radiator and the pump 5 will not significantly
lower the efficiency of the cooling system even if it becomes
warmed with air having passed through the radiator 3 and become
warmer. In addition, by disposing the pump 5 within the air outflow
path, the area to the rear of the radiator 3 can be effectively
utilized so as to achieve overall miniaturization of the cooling
system. It is to be noted that a component other than the pump 5
disposed as described above in the embodiment that will not
adversely affect the cooling system efficiency even if it is
disposed within the outflow path of air having passed through the
radiator 3, may be disposed further to the rear of the radiator 3
so as to provide the cooling system as a more compact unit.
[0088] While FIG. 3, for instance, does not clearly indicate the
positions of the motor 1 and the inverter power source 2, the motor
1 and the inverter power source 2 are disposed in a space further
to the front relative to the cabin but to the rear of an
outside-cabin subsystem ASSY and a cooling subsystem ASSY to be
described later. It is to be noted that the motor 1 and the
inverter power source 2 may, instead, be disposed to the rear
relative to the cabin.
[0089] --Assemblies of Various Units--
[0090] In order to improve the ease with which the electric vehicle
cooling system is installed in a vehicle and improve the ease of
maintenance, the various subsystems constituting the electric
vehicle cooling system in the embodiment are each arranged as an
assembly (systematized). FIG. 5 shows an example of assemblies at
the electric vehicle cooling system in the embodiment. In the
example presented in FIG. 5, the radiator 3 and the fan 4 are
assembled into a single assembly to be referred to as an
outside-cabin subsystem ASSY, the pump 5, the compressor 7, the
middle heat exchanger 8 and the adjustment valve 9 are assembled
together into a single assembly to be referred to as a cooling
subsystem ASSY, and the motor 1 and the inverter power source 2 are
assembled together into a single assembly to be referred to as a
heat discharge subsystem ASSY. The various components to constitute
each ASSY are assembled together and connected via piping or the
like so that an integrated ASSY is ready for installation in the
vehicle. Since the various ASSYs are each put together in advance
before they are installed in the vehicle, the various components in
the assemblies do not need to be connected via piping or the like
after the ASSYs are installed in the vehicle and components become
less accessible. In other words, better ease of assembly is
assured.
[0091] The ASSYs put together in advance as described above are
mounted at a frame (not shown) of the vehicle. It is to be noted
that although not shown, a frame for each ASSY, for instance, may
be designed so as to facilitate connection with the vehicle frame
and, in such a case, the various ASSYs can be mounted in the
vehicle with better ease. Once the individual ASSYs are installed
in the vehicle, the cooling-medium circulation passages in the
ASSYs are connected via coupling means in order to allow the
cooling medium to be distributed among the various ASSYs. There are
no specific restrictions imposed on the type of couplings used for
this purpose. Couplings, often referred to as quick-release
couplings, which can be quickly connected and disconnected, or
standard couplings other than quick-release couplings may be
used.
[0092] It is to be noted that the cooling-medium circulation
passage of each ASSY is connected with the cooling-medium
circulation passage of another ASSY at an area located on the upper
side or the lower side of the ASSY so as to facilitate the
connection of the cooling-medium circulation passages at the
different ASSYs. Namely, the connection area located on the upper
side or the lower side of a given ASSY is easily accessible by the
technical personnel connecting the cooling-medium circulation
passage of the ASSY with the cooling-medium circulation passage of
another ASSY after the ASSYs are installed in the vehicle and thus,
the connection work is facilitated. It is to be noted that the
cooling medium in the cooling-medium circulation passage can be
discharged with ease by disengaging the connection area located on
the lower side of the ASSY, and thus, the cooling medium can be
changed with better ease by setting the connection area on the
lower side.
[0093] Furthermore, it is desirable to form the connection areas
where the cooling-medium circulation passages of two successive
ASSYs are connected either on the upper side or on the lower side
in order to assure the maximum connection work efficiency. For
instance, while the connection areas where the cooling-medium
circulation passages of the outside-cabin subsystem ASSY and the
cooling subsystem ASSY are connected with each other so as to allow
the cooling medium to flow from the outside-cabin subsystem ASSY to
the cooling subsystem ASSY and the connection areas where the
cooling-medium circulation passages of the cooling subsystem ASSY
and the outside-cabin subsystem ASSY are connected with each other
so as to allow the cooling medium to flow from the cooling
subsystem ASSY to the outside-cabin subsystem ASSY are all located
on the lower side of the individual ASSYs in the example presented
in FIG. 5, the connection areas may all be set on the upper side of
the individual assemblies, instead. Likewise, while the connection
areas where the cooling-medium circulation passages of the cooling
subsystem ASSY and the heat discharge subsystem ASSY are connected
with each other so as to allow the cooling medium to flow from the
cooling subsystem ASSY to the heat discharge subsystem ASSY and the
connection areas where the cooling-medium circulation passages of
the heat discharge subsystem ASSY and the cooling subsystem ASSY
are connected with each other so as to allow the cooling medium to
flow from the heat discharge subsystem ASSY to the cooling
subsystem ASSY are all located on the lower side of the individual
ASSYs in the example presented in FIG. 5, the connection areas may
all be set on the upper side of the individual ASSYs instead.
[0094] It is to be noted that a principle similar to that of
locating the cooling-medium circulation passage connection areas on
the upper side or the lower side of the individual ASSYs or only
either on the upper side or the lower side of the ASSYs to achieve
the advantages described above is applicable to electric wiring
connection areas. Namely, by disposing electric system wiring
connection areas (connectors) on the upper side or the lower side
of the various ASSYs or by disposing them only either on the upper
side or the lower side of the ASSYs, advantages similar to those
described above are achieved. In addition, by disposing the
electric system connectors near the cooling-medium circulation
passage connection areas, greater ease of assembly can be achieved.
It is desirable that an electric system connector be disposed
further upward relative to a cooling-medium circulation passage
coupling so as to ensure that the electric system connector is
never wetted with cooling medium discharged from the cooling-medium
circulation passage coupling area during maintenance work.
[0095] --Positional Arrangement of the Various Components in the
Heat Discharge Subsystem ASSY--
[0096] In the heat discharge subsystem ASSY, the second cooling
medium is circulated so as to first travel to the inverter power
source 2 to cool the inverter power source 2 and then to the motor
1 to cool the motor 1 as explained earlier. The various components
are designed so that, under normal circumstances, the cooling
medium flows from the bottom side of the component toward the top
side of the component. For this reason, the intake port through
which the cooling medium is delivered into the component is
normally disposed near the bottom of the component, whereas the
outlet port through which the cooling medium is let out is normally
disposed near the top of the component. In an electric vehicle
cooling system in the related art, the inverter power source 2 is
typically disposed at a position higher than the motor 1 and thus,
the second cooling medium delivered into the inverter power source
2 through its bottom side and then discharged through the top side
of the inverter power source 2 needs to be directed toward the
bottom side of the motor 1, disposed further downward relative to
the inverter power source 2. This means that a long cooling-medium
circulation passage 6b is required, which, in turn, leads to an
increase in the volume of the second cooling medium in the
cooling-medium circulation passage 6b and an increase in the
thermal capacity of the second cooling medium, giving rise to
concerns with respect to the cooling temperature response (i.e.,
the temperature of the second cooling medium cannot be readily
lowered at the middle heat exchanger 8) and an increase in the
weight.
[0097] Accordingly, in the heat discharge subsystem ASSY achieved
in the embodiment, the inverter power source 2 is disposed below
the motor 1, as shown in FIG. 6 so that the second cooling medium,
having been discharged through the top side of the inverter power
source 2, can easily be directed to a lower area of the motor 1
disposed above the inverter power source 2. This positional
arrangement makes it possible to reduce the length of the
cooling-medium circulation passage 6b and thus reduce the volume of
the second cooling medium in the cooling-medium circulation passage
6b, thereby achieving a decrease in the thermal capacity of the
second cooling medium, which, in turn, leads to an improvement in
cooling temperature response, and a reduction in the weight of the
second cooling medium and makes it possible to provide the electric
vehicle cooling system as a lighter-weight unit. It is to be noted
that while the order in which the cooling medium is delivered to
the individual components, which are disposed one higher than the
other, has been described in reference to the motor 1 and the
inverter power source 2, this concept is applicable to components
other than the motor 1 and the inverter power source 2.
[0098] The following advantages are achieved through the electric
vehicle cooling system in the embodiment described above.
[0099] (1) The compressor 7 and the middle heat exchanger 8, which
form large projection areas viewed from the front side of the
vehicle, are not disposed within the outflow path through which air
having passed through the radiator 3 travels. Through these
measures, the extent of pressure loss occurring in the air passing
through the radiator 3 is reduced so as to improve the efficiency
of the cooling system. In addition, since the compressor 7 and the
middle heat exchanger 8 do not come into contact with and thus are
not warmed by the air, the temperature of which has risen as it has
passed through the radiator 3, the efficiency of the cooling system
is sustained.
[0100] (2) The pump 5 is disposed in the outflow path of air having
passed through the radiator 3. The area to the rear of the radiator
3 is thus effectively utilized to achieve miniaturization of the
overall cooling system.
[0101] (3) Once the various components constituting the electric
vehicle cooling system are installed in the vehicle, access to the
individual components becomes limited, as they are bound to be
blocked by surrounding components or the like, and assembly work
such as piping connection is thus bound to be hindered. However, in
the electric vehicle cooling system achieved in the embodiment
constituted with subsystems each put together in advance in the
form of an assembly, the individual components in each ASSY do not
need to be connected via piping or the like after they are mounted
in the vehicle but rather, the cooling-medium circulation passages
in the various ASSYs can be connected with one another simply by
connecting them together via couplings, resulting in improved ease
of assembly.
[0102] (4) As shown in FIG. 5, the connection areas where the
cooling-medium circulation passages of the outside-cabin subsystem
ASSY and the cooling subsystem ASSY are connected with each other
to allow the cooling medium to flow from the outside-cabin
subsystem ASSY to the cooling subsystem ASSY and the connection
areas where the cooling-medium circulation passages of the cooling
subsystem ASSY and the outside-cabin subsystem ASSY are connected
with each other to allow the cooling medium to flow from the
cooling subsystem ASSY to the outside-cabin subsystem ASSY are both
set either on the lower side or the upper side of the individual
ASSYs. Likewise, the connection areas where the cooling-medium
circulation passages of the cooling subsystem ASSY and the heat
discharge subsystem ASSY are connected with each other to allow the
cooling medium to flow from the heat discharge subsystem ASSY to
the heat discharge subsystem ASSY and the connection areas where
the cooling-medium circulation passages of the heat discharge
subsystem ASSY and the cooling subsystem ASSY are connected with
each other to allow the cooling medium to flow from the heat
discharge subsystem ASSY to the cooling subsystem ASSY are both set
either on the lower side or the upper side of the individual ASSYs.
As a result, the cooling-medium circulation passages of the ASSYs
set next to each other can be connected or disconnected all at once
through the bottom side or the top side of the vehicle, which leads
to improved ease of operation and maintenance.
[0103] (5) The second cooling medium is distributed in a specific
order so that it first cools a component with a relatively low
limit defining the maximum temperature that can be tolerated
thereat is relatively low (i.e., the inverter power source 2) and
then cool the component with a relatively high limit defining the
maximum temperature that can be tolerated thereat (i.e., the motor
1). As a result, the various components can be cooled with a high
level of efficiency. In addition, as the components are cooled
efficiently, more heat is taken into the second cooling medium,
raising the temperature of the second cooling medium ready to flow
into the middle heat exchanger 8. Consequently, the temperature
difference between the first cooling medium and the second cooling
medium increases, making it possible to allow more heat to be
transferred at the middle heat exchanger 8 (increase the amount of
heat exchanged) and, ultimately, improve the cooling efficiency of
the electric vehicle cooling system.
[0104] (6) The inverter power source 2 is disposed below the motor
1 so that the second cooling medium having been discharged through
the top side of the inverter power source 2 can be readily
delivered to the bottom side of the motor 1 disposed above the
inverter power source 2. This positional arrangement makes it
possible to reduce the length of the cooling-medium circulation
passage 6b and thus reduce the volume of the second cooling medium
in the cooling-medium circulation passage 6b, thereby achieving a
decrease in the thermal capacity of the second cooling medium,
which, in turn, leads to an improvement in the cooling temperature
response, and a reduction in the weight of the second cooling
medium, and makes it possible to provide the electric vehicle
cooling system as a lighter-weight unit.
[0105] --Variations--
[0106] (1) While the radiator 3 and the fan 4 are assembled
together so as to constitute the outside-cabin subsystem ASSY, the
pump 5, the compressor 7, the middle heat exchanger 8 and the
adjustment valve 9 are assembled together so as to constitute the
cooling subsystem ASSY and the motor 1 and the inverter power
source 2 are assembled together so as to constitute the heat
discharge subsystem ASSY in the embodiment described above, the
assembling range of the present invention is not limited to this
example. For instance, the radiator 3, the fan 4, the pump 5, the
compressor 7, the middle heat exchanger 8 and the adjustment valve
9 may be assembled together to constitute a cooling subsystem ASSY
and the motor 1 and the inverter power source 2 may be assembled
together so as to constitute an heat discharge subsystem ASSY, as
shown in FIG. 7. It is to be noted that FIG. 8 provides a schematic
view of an electric vehicle cooling system constituted with a
cooling subsystem ASSY and an heat discharge subsystem ASSY, such
as that shown in FIG. 7, taken from a position diagonally to the
front of the vehicle.
[0107] (2) While the cooling system described above includes a
single middle heat exchanger 8, the present invention is not
limited to this example. For instance, the second cooling system
may include two separate paths, one constituted with a circulation
passage 6c used to cool the cooling target objects and the other
constituted with a circulation passage 6d used for purposes of
air-conditioning in the temperature of the air within the cabin,
with a middle heat exchanger 8a and a middle heat exchanger 8b each
disposed in one of the two paths. FIG. 9 shows the configuration of
an electric vehicle cooling system with circulation passages
forming two separate paths as described above. FIG. 10 is a
schematic view of the front side of the vehicle with this electric
vehicle: system installed therein, taken from above, whereas FIG.
11 is a schematic view of the electric vehicle cooling system
installed in the vehicle, taken from a position diagonally to the
front of the vehicle.
[0108] It is to be noted that in FIGS. 9 through 11, the same
reference numerals are assigned to components similar to those
described earlier and that the following explanation focuses on
features differentiating this variation from the embodiment
described earlier. In addition, FIGS. 9 through 11 do not include
illustrations of the fan drive device 21a, the compressor drive
device 21b, the pump drive device 22, the control device 23 and
components connected to the control device 23, such as the sensors
24, 25 and 31 and a repeated explanation of these devices and
components is not provided.
[0109] In the circulation passage 6c used to cool the cooling
target objects, the second cooling medium force-fed from a pump 5a
releases its heat at the heat exchanger 8a so as to transfer the
heat to the first cooling medium in the first cooling system and
then the second cooling medium is sequentially guided to the
inverter power source 2 and the motor 1 to cool these cooling
target objects. In the cabin internal air-conditioning path 6d, the
second cooling medium force-fed from a pump 5b first releases its
heat at the heat exchanger 8b so as to transfer the heat to the
first cooling medium in the first cooling system and then the
second cooling medium travels to a radiator 3b where it absorbs
heat from the cabin internal air driven by a fan 4a so as to cool
the air inside the cabin.
[0110] In the first cooling system, heat exchange with the second
cooling medium in the second cooling system is achieved through two
separate paths, with an adjustment valve 9a and the heat exchanger
8a disposed in the cooling target object cooling path and an
adjustment valve 9b and the heat exchanger 8b disposed in the cabin
internal air-conditioning path. The other components, i.e., the
radiator 3, the fan 4, and the compressor 7 are disposed as has
been described in reference to the first cooling system.
[0111] Through this cooling system, the electric vehicle drive
devices, i.e., the motor 1 and the inverter power source 2, can be
cooled and the air inside the cabin can be cooled with a single
refrigerating cycle, without having to configure separate
refrigerating cycles for cooling the cooling target objects such as
the motor 1 and the inverter power source 2 and for cooling the air
inside the cabin.
[0112] As shown in FIGS. 10 and 11, the radiator 3 is disposed on
the front side of the vehicle so that the outside air passes
through the radiator 3 from the front side of the vehicle toward
the rear side of the vehicle in the electric vehicle cooling
system. In addition, the compressor 7 and the middle heat
exchangers 8a and 8b are disposed further rearward relative to the
radiator 3 at positions offset to the right and left relative to
the position of the radiator 3, outside of the primary outflow path
through which air having passed through the radiator 3 flows out to
the outside of the vehicle. The pumps 5a and 5b, however, are
disposed within the outflow path of air having passed through the
radiator 3. It is to be noted that the positional arrangement with
which the individual components are disposed, as shown in FIGS. 10
and 11, simply represents an example and that the present invention
may be achieved with components disposed with a different
positional arrangement. For instance, the right/left positional
relationship between the compressor 7 and the middle heat
exchangers 8a and 8b may be reversed, the middle heat exchangers 8a
and 8b disposed one in front of the other may be disposed
side-by-side, or the pumps 5a and 5b disposed side-by-side may be
disposed one in front of the other.
[0113] (3) While the heat cycle systems in the variations described
above include an air-conditioning system through which the
condition of the air inside the cabin is adjusted and a temperature
control system through which the temperatures of heat generating
members such as the battery 100, the motor generator 200
(equivalent to the traveling drive motor 1) and the inverter device
300 (equivalent to the inverter power source 2) are adjusted, the
temperature control system may be configured as described
below.
[0114] An energy source is required to engage the air-conditioning
system and the temperature control system in operation. In the EV
1000, the battery 100, which is the drive power source for the
motor generator 200, is used as the energy source for the
air-conditioning system and the temperature control system. The
electric energy provided from the battery 100 and used up in the
air-conditioning system and the temperature control system is
relatively high compared to the level of electric energy used in
other electric loads.
[0115] A great deal of interest is focused on the EV 1000 because
it gives less (zero) harmful effects to the global environmental
than hybrid vehicles (hereafter referred to as HEV).
[0116] However, since the EV 1000 is able to travel over only a
relatively short distance per battery charge and the required
infrastructure, such as charging stations (electric power kiosks),
is not yet fully in place, the EV 1000 is yet to gain popularity
over HEVs in the marketplace. In addition, since the EV 1000
requires more electric energy than an HEV to travel the required
cruising distance, the battery 100 of the EV 1000 must assure a
greater capacity than the battery in an HEV. This means that the
cost of the battery 100 in the EV 1000 is bound to be higher than
the battery in an HEV and, since this raises the price of the
vehicle to a level significantly higher than that of a comparable
HEV, the EV 1000 is slower in gaining popularity compared to
HEVs.
[0117] One of the critical factors that will contribute to
acceptance of the EV 1000 by the general public is an increase in
the traveling range of the EV on a single charge of the battery
100. In order to increase the range of the vehicle, consumption of
electric energy from the battery 100 for purposes other than
driving the motor generator 200 needs to be minimized.
[0118] The temperatures of the heat generating devices such as the
battery 100, the motor generator 200 and the inverter device 300
are adjusted via the temperature control system so as to keep them
within an allowable temperature range. In addition, the output of a
heat generating device changes rapidly as load fluctuations occur
in the EV 1000 and such a change results in a change in the amount
of heat generated. It is desirable that the temperature of the heat
generating device be kept at an optimal level at all times by
adjusting the temperature control capability for the heat
generating device in line with any change in the amount of heat
generated at the heat generating device (temperature of the heat
generating device) so as to engage the heat generating device in
operation with high efficiency.
[0119] At the same time, for the EV 1000 to become accepted more in
the marketplace, the costs of the heat generating devices such as
the battery 100, the motor generator 200 and the inverter device
300 must be lowered so as to ultimately lower the price of the EV
1000 to that comparable to the price of an HEV. In order to lower
the cost of a heat generating device, the heat generating device
needs to be miniaturized while assuring a higher output. However, a
compact heat generating device capable of providing higher output
is bound to generate more heat (higher temperature) which will
necessitate an increase in the temperature control capability for
the heat generating device.
[0120] Accordingly, the heat cycle system in the variation may be
configured by integrating the temperature control system and the
air-conditioning system so that the air inside the cabin can be
conditioned and the temperatures of the heat generating devices can
be controlled by efficiently utilizing the thermal energy within
the heat cycle system of the EV 1000.
[0121] In more specific terms, the heat cycle may be divided into a
primary side heat cycle (first cooling system) through which heat
exchange with the outside (outside the cabin) is achieved and a
secondary side heat cycle (second cooling system) through which
heat exchange with the inside (inside the cabin) and with the heat
generating device side is achieved, the primary side heat cycle may
be configured with a refrigerating cycle system, the secondary side
heat cycle circuit may be configured with two heat transfer systems
in which heat exchange media are distributed independently of each
other, a middle heat exchanger 8a and a middle heat exchanger 8b
may be respectively disposed between the refrigerating cycle system
and one of the two heat transfer systems and between the
refrigerating cycle system and the other heat transfer system so as
to allow the cooling medium in the refrigerating cycle system to
individually exchange heat with the heat exchange media in the two
heat transfer systems, and an inside heat exchanger may be disposed
in the heat transfer system engaged in heat exchange with the heat
generating device side so as to allow the heat exchange medium in
the heat transfer system engaged in heat exchange with the heat
generating device side to exchange heat with the air taken into the
cabin.
[0122] In the temperature control system configured as described
above, thermal energy obtained by adjusting the temperatures of the
heat generating devices can be utilized for purposes of
conditioning the air inside the cabin so as to minimize the energy
required for conditioning the air inside the cabin and ultimately
achieve a high level of energy efficiency in air-conditioning.
Furthermore, in the temperature control system configured as
described above, the thermal energy obtained by adjusting the
temperatures of the heat generating devices is directly utilized
for cabin air-conditioning to further improve the energy efficiency
in the cabin air conditioning. Consequently, by configuring the
temperature control system as described above, the level of energy
taken out to the air-conditioning system from the heat generating
device energy source can be kept down.
[0123] The heat cycle system structured as described above is ideal
for extending the distance over which the EV 1000 is able to travel
after a single charge of the battery 100. From a different
perspective, the heat cycle system will prove ideal for minimizing
the capacity required of the battery 100 in a vehicle capable of
traveling a distance comparable to that achieved in the related art
on power provided from the battery 100 after a single charge. The
EV 1000 with a smaller capacity battery 100 can be manufactured at
lower cost and lighter weight, which will help the EV 1000 gain
wider consumer acceptance.
[0124] In addition, in the temperature control system configured as
described above in which the thermal energy used for purposes of
cabin air conditioning is also utilized in the heat generating
device temperature adjustment, the temperature of the heat exchange
medium used to adjust the temperatures of the heat generating
devices can be adjusted over a wider temperature range. As a
result, the temperatures of the heat generating devices can be
altered, free of any influence attributable to the surrounding
environment conditions. Thus, the temperature of each heat
generating device can be adjusted to an optimal level at which the
heat generating device is able to operate at high efficiency and
the heat generating device can be engaged in operation in a very
efficient manner by configuring the temperature control system as
described above.
[0125] The heat cycle system described above will prove to be an
ideal means for reducing the manufacturing cost of the EV 1000. The
marketability of the EV 1000 manufactured at lower cost is bound to
improve significantly.
[0126] (4) In addition, when a heat cycle system achieved by
integrating the temperature control system and the air-conditioning
system as in the variation described above is installed in the EV
1000, the piping used to constitute the flow passages and the
various components may crowd the limited installation space. In
view of requirements such as ease of maintenance, further
miniaturization and lower manufacturing costs that heat cycle
systems today must fulfill, the system configuration of the heat
cycle system installed in the EV 1000 should be simplified as much
as possible by miniaturizing components, reducing the number of
components and allowing components to be commonly used for multiple
purposes.
[0127] Accordingly, the circulation passage in a first heat
transfer system, through which the heat exchange medium used to
adjust the temperature of the heat generating devices circulates,
thermally connected via the middle heat exchanger 8a to the
refrigerating cycle system through which the cooling medium
circulates, and the circulation passage in a second heat transfer
system through which the heat exchange medium used to adjust the
condition of the air inside the cabin circulates, thermally
connected via the middle heat exchanger 8b to the refrigerating
cycle system through which the cooling medium circulates, may be
set in communication with each other, and a common reservoir tank,
via which the pressures in the circulation passages in the first
and second heat transfer systems are adjusted, may be disposed to
operate in conjunction with both the first heat transfer system and
the second heat transfer system.
[0128] By configuring the temperature control system as described
above, a component can be shared by the first and second heat
transfer systems, making it possible to simplify the heat cycle
system. By simplifying the configuration of the heat cycle system,
the ease with which the heat cycle system installed in the EV 1000
is maintained can be improved. Furthermore, such simplification is
bound to contribute to achieving miniaturization and lower
manufacturing costs for the heat cycle system.
[0129] (5) While the electric vehicle cooling system is disposed
further frontward relative to the cabin in the embodiment described
above, the present invention is not limited to this example. For
instance, the electric vehicle cooling system may be disposed
further rearward relative to the cabin. It is to be noted that
although not shown, the outside air can be delivered to the
radiator 3 in the electric vehicle cooling system disposed further
rearward relative to the cabin via an air delivery passage formed,
for instance, under the floor of the vehicle and extending toward
the front and the rear of the vehicle.
[0130] (6) While the motor 1 and the inverter power source 2 are
cooled with the second cooling medium in the embodiment described
above, the present invention is not limited to this example. For
instance, the motor 1 and the inverter power source 2 may be cooled
with cooling air and the air inside the cabin may be conditioned
via the refrigerating cycle. In other words, the configuration
described earlier in reference to FIG. 9 does not need to include
the cooling target object cooling-medium circulation passage 6c. In
such a case, too, the compressor 7 and the middle heat exchanger 8b
should be disposed further to the rear of the radiator 3 with
offsets to the right and the left relative to the position of the
radiator 3 outside of the outflow path of air having passed through
the radiator 3 and flowing out of the vehicle so as to achieve
advantages similar to those described earlier.
[0131] (7) The embodiment and the variations described above may be
adopted in any combination.
[0132] It is to be noted that the present invention is not limited
in any way whatsoever to the structural particulars of the
embodiments described above and that a cooling system for an
electric vehicle adopting any one of various structures, comprising
a cooling-medium circulation passage through which a cooling medium
circulates to travel to heat exchange target objects mounted in a
vehicle that is electrically driven, an electric compressor
disposed in the cooling-medium circulation passage to compress the
cooling medium and a heat exchange means for achieving heat
exchange between the cooling medium and the outside air and
characterized in that the electric compressor is disposed at a
position outside a primary outflow path through which the outside
air, having undergone heat exchange at the heat exchange means,
flows from the heat exchange means to the outside of the vehicle,
is within the scope of the present invention.
[0133] The present invention is not limited in any way whatsoever
to the structural particulars of the embodiment described above and
a cooling system for an electric vehicle adopting any one of
various structures, comprising a cooling-medium circulation passage
through which a cooling medium circulates to travel to heat
exchange target objects mounted in a vehicle that is electrically
driven, an electric compressor disposed in the cooling-medium
circulation passage to compress the cooling medium, a heat exchange
means for achieving heat exchange between the cooling medium and
the outside air and another cooling-medium circulation passage
different from the cooling-medium circulation passage, through
which another cooling medium, different from the cooling medium,
circulates to travel to electric drive devices including a motor
and an inverter power source, and characterized in that the heat
exchange target objects include a middle heat exchange means for
achieving heat exchange between the cooling medium and the other
cooling medium, and that the middle heat exchange means is disposed
at a position outside a primary outflow path through which the
outside air, having undergone heat exchange at the heat exchange
means, flows from the heat exchange means to the outside of the
vehicle, is within the scope of the present invention.
[0134] The present invention is not limited in any way whatsoever
to the structural particulars of the embodiment described above and
a cooling system for an electric vehicle adopting any one of
various structures comprising a cooling-medium circulation passage
through which a cooling medium circulates to travel to heat
exchange target objects mounted in a vehicle that is electrically
driven, an electric compressor disposed in the cooling-medium
circulation passage to compress the cooling medium and a heat
exchange means for achieving heat exchange between the cooling
medium and the outside air and characterized in that the
cooling-medium circulation passage in a first assembly preassembled
prior to installation in the electric vehicle, which includes at
least the heat exchange means, and the cooling-medium circulation
passage in a second assembly preassembled prior to installation in
the electric vehicle, which includes at least some of the heat
exchange target objects, are connected via a coupling so as to
allow the cooling-medium circulation passage in the first assembly
and the cooling-medium circulation passage in the second assembly
to be connected with each other and disconnected from each other in
a frontward position and a rearward position of the coupling, is
within the scope of the present invention.
[0135] The present invention is not limited in any way whatsoever
to the structural particulars of the embodiment described above and
a cooling system for an electric vehicle adopting any one of
various structures, installed in a vehicle electrically driven by
electric drive devices and used to cool the electric drive devices,
comprising a heat exchange means for achieving heat exchange
between a cooling medium and outside air, a cooling-medium
circulation passage through which cooling medium circulates, an
electric compressor disposed in the cooling-medium circulation
passage to compress the cooling medium, another cooling-medium
circulation passage, different from the cooling-medium circulation
passage, through which another cooling medium, different from the
cooling medium, circulates to travel to the electric drive devices
including a motor and an inverter power source, and a middle heat
exchange means for achieving heat exchange between the cooling
medium and the other cooling medium, configured with a first
assembly preassembled prior to installation in the electric
vehicle, which includes at least the heat exchange means, a second
assembly preassembled prior to installation in the electric
vehicle, which includes at least the electric compressor and the
middle heat exchange means, and a third assembly preassembled prior
to installation in the electric vehicle, which includes at least
the electric drive devices, and characterized in that the
cooling-medium circulation passage in the first assembly and the
cooling-medium circulation passage in the second assembly are
connected via a coupling so as to allow the cooling-medium
circulation passage in the first assembly and the cooling-medium
circulation passage in the second assembly to be connected with
each other or to be disconnected from each other in a frontward
position and a rearward position of the coupling, and that the
other cooling-medium circulation passage in the second assembly and
the other cooling-medium circulation passage in the third assembly
are connected via a coupling so as to allow the other
cooling-medium circulation passage in the second assembly and the
other cooling-medium circulation passage in the third assembly to
be connected with each other or to be disconnected from each other
in a frontward position and a rearward position of this coupling,
is within the scope of the present invention.
[0136] The present invention is not limited in any way whatsoever
to the structural particulars of the embodiments described above
and a cooling system for an electric vehicle adopting any one of
various structures, installed in a vehicle electrically driven by
electric drive devices and used to cool the electric drive devices,
comprising a heat exchanging means for achieving heat exchange
between a cooling medium and outside air, a cooling-medium
circulation passage through which the cooling medium circulates, an
electric compressor disposed in the cooling-medium circulation
passage to compress the cooling medium, another cooling-medium
circulation passage, different from the cooling-medium circulation
passage, through which another cooling medium, different from the
cooling medium, circulates to travel to electric drive devices
including a motor and an inverter power source, and a middle heat
exchange means for achieving heat exchange between the cooling
medium and the other cooling medium, configured with a first
assembly preassembled prior to installation in the electric
vehicle, which includes at least the heat exchanging means, the
electric compressor and the middle heat exchange means and a second
assembly preassembled prior to installation in the electric
vehicle, which includes at least the electric drive devices and
characterized in that the other cooling-medium circulation passage
in the first assembly and the other cooling-medium circulation
passage in the second assembly are connected via a coupling so as
to allow the other cooling-medium circulation passage in the first
assembly and the other cooling-medium circulation passage in the
second assembly to be connected with each other and disconnected
from each other in a frontward position and a rearward position of
the coupling, is within the scope of the invention.
[0137] While the invention has been particularly shown and
described with respect to a preferred embodiment and variations
thereof by referring to the attached drawings, the present
invention is not limited to these examples and it will be
understood by those skilled in the art that various changes in form
and detail may be made therein without departing from the scope of
the invention.
[0138] The disclosure of the following priority application is
herein incorporated by reference: [0139] Japanese Patent
Application No. 2009-272306 filed Nov. 30, 2009
* * * * *