U.S. patent application number 13/281122 was filed with the patent office on 2013-01-17 for cooling apparatus and cooling method for power-pack in hybrid vehicle.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Chikung Ahn, Minyoung Jung, Daekwang Kim, Junyong Lee. Invention is credited to Chikung Ahn, Minyoung Jung, Daekwang Kim, Junyong Lee.
Application Number | 20130014911 13/281122 |
Document ID | / |
Family ID | 47425385 |
Filed Date | 2013-01-17 |
United States Patent
Application |
20130014911 |
Kind Code |
A1 |
Lee; Junyong ; et
al. |
January 17, 2013 |
COOLING APPARATUS AND COOLING METHOD FOR POWER-PACK IN HYBRID
VEHICLE
Abstract
A cooling apparatus for a power-pack in a hybrid vehicle may
include a power-pack that acquires traveling information of the
vehicle and controls the operation of an engine and a motor, a
low-temperature radiator that is connected with power-pack through
a cooling water channel, dissipates heat from the cooling water
discharged from power-pack, and is arranged in parallel with a
radiator, and an electric water pump that is disposed in the
cooling water channel and operated in response to an electric
signal output from an ECU to circulate the cooling water through
power-pack and low-temperature radiator. The cooling apparatus may
also include a cooling fan. A cooling method of using the cooling
apparatus may include determining engine operation, determining
start of a water pump, and operating a water pump. The cooling
method may also include starting a cooling fan, operating a cooling
and examining a water pump.
Inventors: |
Lee; Junyong; (Hwaseong-si,
KR) ; Ahn; Chikung; (Hwaseong-si, KR) ; Kim;
Daekwang; (Hwaseong-si, KR) ; Jung; Minyoung;
(Hwaseong-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lee; Junyong
Ahn; Chikung
Kim; Daekwang
Jung; Minyoung |
Hwaseong-si
Hwaseong-si
Hwaseong-si
Hwaseong-si |
|
KR
KR
KR
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
47425385 |
Appl. No.: |
13/281122 |
Filed: |
October 25, 2011 |
Current U.S.
Class: |
165/51 |
Current CPC
Class: |
B60L 2240/425 20130101;
F01P 7/165 20130101; F01P 3/20 20130101; B60W 30/1843 20130101;
B60L 1/003 20130101; F01P 7/167 20130101; B60L 2240/36 20130101;
F01P 2050/24 20130101; Y02T 10/642 20130101; B60L 1/02 20130101;
B60K 11/02 20130101; Y02T 10/64 20130101; B60W 20/00 20130101 |
Class at
Publication: |
165/51 |
International
Class: |
F01P 9/00 20060101
F01P009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2011 |
KR |
10-2011-0068391 |
Claims
1. A cooling apparatus for a power-pack in a hybrid vehicle that
circulates cooling water discharged from an engine by connecting
the engine with a radiator through a first cooling water channel,
the cooling apparatus comprising: a power-pack that acquires
traveling information of the vehicle and controls an operation of
the engine and a motor; a low-temperature radiator connected with
the power-pack through a second cooling water channel and arranged
in parallel with the radiator, the low-temperature radiator
dissipating heat of the cooling water discharged from the
power-pack; and an electric water pump disposed in the second
cooling water channel and operated in response to an electric
signal output from an Electronic Control Unit (ECU) to circulate
the cooling water through the power-pack and the low-temperature
radiator.
2. The cooling apparatus as defined in claim 1, further comprising
a cooling fan that is controlled by the ECU to introduce an
external air to the low-temperature radiator.
3. The cooling apparatus as defined in claim 2, wherein the cooling
fan is selectively controlled by a Pulse Width Modulation (PWM)
control that controls a rotation speed of the cooling fan in
consideration of the temperature of the power-pack and a speed of
the vehicle or by an On/Off control that controls an operation of
the cooling fan.
4. The cooling apparatus as defined in claim 1, wherein the
low-temperature radiator is positioned ahead of the radiator in the
vehicle.
5. The cooling apparatus as defined in claim 1, wherein the
electric water pump is controlled such that a number of revolution
is determined by a temperature of the power-pack.
6. A cooling method of using the cooling apparatus as defined in
claim 1, comprising: determining start of a water pump that
determines a temperature of the power-pack and starts the electric
water pump if the temperature of the power-pack is above a first
temperature; operating a water pump that operates the electric
water pump such that the cooling water circulates through the
power-pack and the low-temperature radiator if the temperature of
the power-pack is above the first temperature in determining start
of a water pump; and determining engine operation that determines
whether the engine of the vehicle is in operation and proceeds to
determining start of a water pump when the engine is in
operation.
7. The cooling method as defined in claim 6, further comprising:
determining start of a cooling fan that determines whether the
temperature of the power-pack is above a second temperature,
wherein determining start of a cooling fan is performed after
determining start of a water pump and the second temperature is set
higher than the first temperature; and operating a cooling fan that
operates the cooling fan if the temperature of the power-pack is
above the second temperature in determining start of a cooling
fan.
8. The cooling method as defined in claim 7, wherein a Pulse Width
Modulation (PWM) control that controls a rotation speed of the
cooling fan in consideration of the temperature of the power-pack
and a speed of the vehicle or an On/Off control that controls an
operation of the cooling fan is selectively applied in operating a
cooling fan.
9. The cooling method as defined in claim 6, further comprising:
examining a water pump that determines whether there is an error in
the electric water pump, wherein examining a water pump is
performed before determining start of a water pump, and determining
start of a water pump is performed if the electric water pump is in
a normal state in examining a water pump.
10. The cooling method as defined in claim 9, further comprising:
determining entry of a safety mode that determines whether the
temperature of the power-pack is above the first temperature,
wherein determining entry of a safety mode is performed if the
electric water pump is not in the normal state in examining a water
pump; operating in a safety mode that operates the power-pack in
the safety mode if the temperature of the power-pack is above the
first temperature in determining entry of a safety mode; and
operating in a normal mode that operates the power-pack in the
normal mode if the temperature of the power-pack is equal to or
below the first temperature in determining entry of a safety
mode.
11. The cooling method as defined in claim 6, wherein the number of
revolution of the electric water pump is controlled by the
power-pack and determined by the temperature of the power-pack in
operating a water pump.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority of Korean Patent
Application Number 10-2011-0068391 filed Jul. 11, 2011, the entire
contents of which application is incorporated herein for all
purposes by this reference.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a cooling apparatus in a
hybrid vehicle, and more particularly, to a cooing apparatus and a
cooling method for a power-pack in a hybrid vehicle which can
exclusively cool a power-pack that controls energy in the hybrid
vehicle.
[0004] 2. Description of Related Art
[0005] As high-fuel efficiency and environment-friendly vehicles
are on the rise as the main issue in the vehicle industry, hybrid
vehicles using both of an engine and a motor as a power supply are
spotlighted.
[0006] Such hybrid vehicles are equipped with a power-pack, which
is an individual control device, to control driving of the engine
and the motor and the power-pack collects traveling information of
the vehicle and determines which one of the engine and the motor is
used for traveling.
[0007] Since the power-pack generates heat in operation, the heat
should be removed so that the power-pack can keep operating without
being damaged.
[0008] In particular, a mild hybrid vehicle that greatly depends on
the engine uses engine cooling water to cool the power-pack.
[0009] FIG. 1 shows a cooling apparatus for a power-pack in a
hybrid vehicle according to the related art. Referring to FIG. 1, a
common engine cooling apparatus that circulates cooling water
between an engine 111 and a radiator 112 with a mechanical water
pump 113 while controlling the cooling water with a thermostat 114
is shown. A cooling water channel additionally diverges from the
outlet of radiator 112 and the cooling water is circulated in a
power-pack 121 by an electric water pump 123, in the engine cooling
apparatus. A portion of the cooling water discharged out of engine
111 is controlled such that it circulates in a heater by a valve
116 to be used for heating the interior.
[0010] However, with the cooling apparatus for a power-pack in a
hybrid vehicle according to the related art, the cooling water
discharged out of radiator 112 is directly circulated to power-pack
121. Accordingly, the cooling performance reduces and an energy
loss is large due to the operation of electric water pump 123. The
cooling water discharged from radiator 112 is relatively lower in
temperature than the cooling water discharged from engine 111, but
the temperature is still high, such that it is not suitable for
cooling and the cooling performance is correspondingly decreased.
For example, the cooling water temperature of power-pack 121 is
controlled within 95.degree. C. to 100.degree. C. when middle or
more load is applied to engine 111, such that it can be seen that
the cooling performance considerably decreases.
[0011] Since it is required to keep electric water pump 123
operating, a large amount of energy loss is generated.
[0012] There is a limit in the traveling area of the hybrid vehicle
due to the problem.
[0013] The information disclosed in this Background section is only
for enhancement of understanding of the general background of the
invention and should not be taken as an acknowledgement or any form
of suggestion that this information forms the prior art already
known to a person skilled in the art.
SUMMARY OF INVENTION
[0014] Various aspects of the present invention have been made in
an effort to provide a cooling apparatus and a cooling method for a
power-pack in a hybrid vehicle that is individually and efficiently
controlled to cool a power-pack of a hybrid vehicle.
[0015] One aspect of the present invention provides is directed to
provide a cooling apparatus for a power-pack in a hybrid vehicle.
Various exemplary cooling apparatuses according to the present
invention include a power-pack, a low-temperature radiator, and a
pump, such as an electric water pump. The power-pack controls the
operation of an engine and a motor by acquiring traveling
information of the vehicle. The low-temperature radiator is
connected with the power-pack through a cooling channel, such as
the cooling water channel, dissipates heat from the cooling water
discharged from the power-pack, and is arranged in parallel with
the radiator. The electric water pump is disposed in the cooling
water channel and operated in response to an electric signal output
from an Electronic Control Unit (ECU) to circulate the cooling
water or other suitable cooling fluids through the power-pack and
the low-temperature radiator.
[0016] A cooling fan that is controlled by the ECU to introduce the
external air to the low-temperature radiator may be further
included.
[0017] The cooling fan may be controlled selectively by a Pulse
Width Modulation (PWM) control that controls the rotation speed of
the cooling fan in consideration of the temperature of the
power-pack and the speed of the vehicle or an On/Off control that
controls the operation of the cooling fan.
[0018] The low-temperature radiator may be positioned ahead of the
radiator in the vehicle.
[0019] The electric water pump may be controlled such that the
number of revolution is determined by the temperature of the
power-pack.
[0020] Another aspect of the present invention is directed to a
cooling method for a power-pack for a hybrid vehicle. Various
exemplary cooling methods of the present invention for controlling
the cooling apparatus for a power-pack may include determining
start of a water pump, operating a water pump, and determining
engine operation. The step of determining start of a water pump
determines whether the temperature of a power-pack is above a first
temperature which is set to start the electric water pump, by
acquiring traveling information of a hybrid vehicle. The step of
operating a water pump operates the electric water pump such that
the cooling water or other suitable cooling fluids circulate
through the power-pack and the low-temperature radiator if the
temperature of the power-pack is above the first temperature in the
step of determining start of a water pump. The step of determining
engine operation determines whether the engine of the hybrid
vehicle is in operation and proceeds to the step of determining
start of a water pump when the engine is in operation.
[0021] Various exemplary cooling methods of the present invention
may further include determining start of a cooling fan that
determines whether the temperature of the power-pack is above a
second temperature, wherein determining start of a cooling fan is
performed after determining start of a water pump and the second
temperature is set higher than the first temperature; and operating
a cooling fan that operates the cooling fan if the temperature of
the power-pack is above the second temperature in determining start
of a cooling fan.
[0022] PWM control that controls the rotation speed of the cooling
fan in consideration of the temperature of the power-pack and the
speed of the vehicle or On/Off control that controls the operation
of the cooling fan is selectively applied in operating a cooling
fan.
[0023] Examining a water pump that determined whether there is an
error in the electric water pump may be performed before the
determining start of a water pump, and determining start of a water
pump is performed when it is determined that the electric water
pump may be in a normal state in examining a water pump.
[0024] Determining entry of a safety mode that determines whether
the temperature of the power-pack is above a first temperature is
performed when it is determined that the electric water pump is not
in a normal state in examining a water pump. Operating in a safety
mode that operates the power-pack in a safety mode is performed
when it is determined that the temperature of the power-pack is
above the first temperature in the determining entry of a safety
mode. Operating in a normal mode that operates the power-pack in
the normal mode is performed when it is determined that the
temperature of the power-pack is equal to or below the first
temperature in determining entry of a safety mode.
[0025] The number of revolution of the electric water pump is
controlled by the power-pack and determined by the temperature of
the power-pack in operating a water pump.
[0026] According to the various exemplary cooling apparatuses and
cooling methods for a power-pack in a hybrid vehicle, it is
possible to improve cooling performance by independently
circulating the cooling water at low temperature to the power-pack,
since a main radiator that cools the cooling water discharged out
of the engine and the sub-radiator that exclusively cools the
power-pack are separated.
[0027] The temperature of the cooling water circulating in the
power-pack is considerably lower than that of the cooling water
from the engine, resulting in the increases of the efficiency of
the power-pack.
[0028] The apparatus can be operated in a high-temperature area,
such that it is possible to expand available area where the hybrid
vehicle can travel.
[0029] Since it is possible to design the elements in the
power-pack at low permissible temperature, the degree of freedom in
design increases.
[0030] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a conceptual view diagram showing a cooling
apparatus for a power-pack in a hybrid vehicle according to the
related art.
[0032] FIG. 2 is a conceptual view diagram showing an exemplary
cooling apparatus for a power-pack in a hybrid vehicle according to
the present invention.
[0033] FIG. 3 is a flowchart showing an exemplary cooing method for
a power-pack in a hybrid vehicle according to the present
invention.
[0034] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0035] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0036] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that present description is not
intended to limit the invention(s) to those exemplary embodiments.
On the contrary, the invention(s) is/are intended to cover not only
the exemplary embodiments, but also various alternatives,
modifications, equivalents and other embodiments, which may be
included within the spirit and scope of the invention as defined by
the appended claims.
[0037] One aspect of the present invention is directed to a cooling
apparatus for a power-pack in a hybrid vehicle. Hereinafter, an
exemplary cooling apparatus for a power-pack in a hybrid vehicle
according to the present invention is described in detail with
reference to the accompanying drawings.
[0038] A cooling apparatus for a power-pack in a hybrid vehicle
according to various embodiments of the present invention is
disposed independently from a common engine cooling apparatus that
circulates cooling water or other suitable cooling fluids between
an engine 11 and a radiator 12 with a pump such as a mechanical
water pump 13.
[0039] That is, the cooling apparatus for a power-pack in a hybrid
vehicle according to various embodiments of the present invention,
as shown in FIG. 2, includes a power-pack 21, a low-temperature
radiator 22 that is connected with power-pack 21 through a cooling
fluidic channel, such as a cooling water channel, and dissipates
the heat of cooling water or other cooling fluids, and a pump such
as an electric water pump 23 that is disposed in the cooling water
channel between power-pack 21 and low-temperature radiator 22 and
circulates the cooling water.
[0040] Power-pack 21 is a component of a hybrid vehicle that
controls energy for driving the engine and the motor of a hybrid
vehicle. Power-pack 21 generates heat by driving of a vehicle. If
the temperature of the power-pack 21 exceeds a predetermined
temperature, the parts in power-pack 21 may be damaged and the
efficiency may be reduced. Thus, power-pack 21 should be cooled to
a temperature below the predetermined temperature.
[0041] Low-temperature radiator 22 is connected with power-pack 21
through the cooling water channel, which forms a circuit allowing
the cooling water or other suitable cooling fluids to circulate
through power-pack 21 and low-temperature radiator 22. In this
exemplary configuration, cooling water from the engine 11 flows to
the radiator 12 and the heat of the cooling water is dissipated by
the radiator 12, whereas cooling water from the power-pack 21 flows
to the low-temperature radiator 22 and the heat of the cooling
water is dissipated by the low-temperature radiator 22. The
radiator 22 is designated as the low-temperature radiator because
the temperature of the cooling water from the power-pack 21 is
typically lower than that of the cooling water from the engine
11.
[0042] Low-temperature radiator 22 in general has a capacity
smaller than that of radiator 12 and may be positioned in parallel
with and/or ahead of radiator 12. Such construction allows the
cooling water passing through low-temperature radiator 22 comes in
contact with the external air first, because the cooling water is
lower in temperature than the cooling water passing through
radiator 12. If radiator 12 is positioned ahead of low-temperature
radiator 22, the external air is heated by contact with radiator 12
and then comes in contact with low-temperature radiator 22, such
that heat exchange performance decreases; therefore,
low-temperature radiator 22 may be positioned ahead of radiator
12.
[0043] A pump, such as an electric water pump 23 is disposed in the
cooling water channel connecting power-pack 21 with low-temperature
radiator 22. Electric water pump 23, which is operated in response
to an electric signal, operates when an operation signal is
supplied from the outside to circulate the cooling water.
[0044] This configuration may further provide a cooling fan 24 to
promote heat dissipation of radiator 12 and low-temperature
radiator 22. Cooling fan 24 promotes cooling of the cooling water
by blowing the external air to low-temperature radiator 22, when
the cooling water cannot be cooled only by circulation of the
cooling water passing through low-temperature radiator 22 and when
the required cooing amount is large, such as when a vehicle travels
at a low speed.
[0045] Electric water pump 23 and cooling fan 24 are controlled by
an Electronic Control Unit (ECU). ECU 25 determines whether
electric water pump 23 or cooling fan 24 operates on the basis of
temperature information received from power-pack 21 (a), and sends
a control signal to operate electric water pump 23 (b) or cooling
fan 24 (c). For example, when the temperature of power-pack 21 is
inputted, ECU determines the number of revolution of electric water
pump 23 which corresponds to the temperature of power-pack 21 and
outputs a control signal corresponding to the voltage control
amount fitting to the number of revolution, using a protocol, such
as Controller Area Network (CAN) or Local Interconnect Network
(LIN).
[0046] When controlling cooling fan 24, ECU 25 controls cooling fan
24, using Pulse Width Modulation (PWM) control or On/Off control,
by determining the voltage control amount for operating cooling ran
24 in consideration of the vehicle speed and the temperature of
power-pack 21. That is, the voltage control amount is determined on
a table made in advance, reflecting the vehicle speed and the
temperature of power-pack 21, and is selectively used for the PWM
control or the On/Off control. It is possible to control the amount
of air flowing inside through cooling fan 24 by controlling the
speed of a motor that operates cooling fan 24 through the PWM
control, or operate cooling fan 24 through the On/Off control every
time cooling fan 24 needs to operate.
[0047] Reference numerals `15` and `16` indicate a heater and a
valve that are used for heating the interior by using the heat of
the cooling water of engine 11.
[0048] Another aspect of the present invention is directed to a
cooling method for cooling a power-pack of a hybrid vehicle. A
cooling method according to various embodiments of the present
invention is as follows.
[0049] A cooling method of a power-pack of a hybrid vehicle
according to various embodiments of the present invention, as shown
in FIG. 3, includes determining start of a water pump (S120),
operating a water pump (S130), and determining engine operation
(S160). Determining start of a water pump (S120) determines whether
the temperature of the cooing water is above a first temperature T1
set to start electric water pump 23, operating a water pump (S130)
operates electric water pump 23 when the temperature of the
power-pack is above first temperature T1, determining engine
operation (S160) determines whether engine 11 of the hybrid vehicle
operates, and determining start of water pump (120) is performed
again when engine 11 is in operation.
[0050] Determining start of water pump (S120) determines whether
the temperature of the cooling water circulating through power-pack
21 and low-temperature radiator 22 is above first temperature T1
that is set to start electric water pump 23. When the temperature
is above first temperature T1, electric water pump 23 is operated
such that the cooling water circulates through power-pack 21 and
low-temperature radiator 22, thereby cooling power-pack 21 that
generates heat. As electric water pump 23 operates, the cooling
water takes heat from power-pack 21 and the heat is dissipated
through low-temperature radiator 22 while the cooling water
circulates between power-pack 21 and low-temperature radiator 22,
such that power-pack 21 can maintain an appropriate
temperature.
[0051] On the other hand, when the temperature of power-pack 21 is
equal to or below first temperature T1, electric water pump 23 is
not operated. This is because efficiency is high when power-pack 21
operates at an appropriate temperature range, and accordingly, when
the temperature of power-pack 21 is equal to or below first
temperature T1, electric water pump 23 is not operated until
power-pack's temperature raises to above the appropriate
temperature range.
[0052] It is preferable to perform examining a water pump (S110)
that determines whether electric water pump 23 is in the normal
state, before performing determining start of a water pump (S120).
For example, it is examined whether ECU 25 can normally control
electric water pump 23 by sensing disconnection or a short circuit
of a control signal line that electrically connects ECU 25 with
electric water pump 23. Operating a water pump (S130) that is
described below is performed only when it is determined that
electric water pump 23 is in the normal state in examining a water
pump (S110).
[0053] Operating a water pump (S130) allows the cooling water to
circulate between power-pack 21 and low-temperature radiator 22 by
operating electric water pump 23 when the temperature of power-pack
21 is above first temperature T1. As the cooling water circulates
through power-pack 21 and low-temperature radiator 22, the cooling
water takes heat from power-pack 21 and dissipates the heat through
low-temperature radiator 22, such that power-pack 21 maintains at
an appropriate temperature range.
[0054] Determining engine operation (S160) determines whether
engine 11 is in operation and performs determining start of a water
pump (S120) when engine 11 is in operation, or finishes the control
when engine 11 has stopped.
[0055] Meanwhile, when the temperature of power-pack 21 is above a
set temperature, it is difficult to cool power-pack 21 only by
circulating the cooling water through power-pack 21 and
low-temperature radiator 22 with electric water pump 23. To
effectively cool power-pack 21, determining start of a cooling fan
(S140) and operating a cooling fan (S150) that operates cooling fan
24 are performed to promote cooling by operating cooling fan
24.
[0056] Determining start of a cooling fan (S140) determines whether
the temperature of power-pack 21 is above a second set temperature
T2. Second temperature T2 is set higher than first temperature T1
and is used as a determination basis for additionally operating
cooling fan 24 when power-pack 21 cannot be sufficiently cooled
only by simple circulation of the cooling water.
[0057] Operating cooling fan (S150) additionally operates cooling
fan 24 when it is determined that the temperature of power-pack 21
is above second temperature T2 in determining start of cooling fan
(S140). The temperature of power-pack 21 is naturally above first
temperature when being above second temperature T2, such that
cooling fan 24 is additionally operated, with electric water pump
23 operating. As cooling fan 24 operates, the external air is
introduced to low-temperature radiator 22, such that the heat
dissipation performance of low-temperature radiator 22 increases
and the cooling performance of power-pack 21 is improved. When the
vehicle speed is low, it is possible to operate cooling fan 24 even
if the amount of external air introduced to low-temperature
radiator 22 is small. Accordingly, the variables of controlling
cooling fan 24 are the temperature of the power-pack and the speed
of the vehicle.
[0058] Meanwhile, when it is determined that electric water pump 23
is in the abnormal state in examining a water pump (S110),
determining entry of a safety mode (S170) that determines whether
the temperature of power-pack 21 is above first temperature T1 is
performed.
[0059] When it is determined that the temperature of power-pack 21
is equal to or below first temperature T1 in determining entry of a
safety mode (S170), it is not necessary to cool power-pack 21. In
this case, electric water pump 23 is not operated and the process
proceeds to operating in a normal power-pack mode (S172).
[0060] Meanwhile, when it is determined that the temperature of
power-pack 21 is above first temperature T1 in determining entry of
a safety mode (S170), the cooling water is circulated by electric
water pump 23 or cooling fan 24 is operated, power-pack 21 is
operated in safety mode (S171).
[0061] For convenience in explanation and accurate definition in
the appended claims, the terms upper or lower, front or rear,
inside or outside, and etc. are used to describe features of
various embodiments with reference to the positions of such
features as displayed in the figures.
[0062] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
* * * * *