U.S. patent application number 12/961242 was filed with the patent office on 2011-11-03 for apparatus for controlling water pump of hybrid vehicle and method thereof.
This patent application is currently assigned to KIA MOTORS CORPORATION. Invention is credited to Jae Young Choi, Seok Joon Kim, Jae Heon Lee, Byungsoon Min, Hyungseuk Ohn.
Application Number | 20110265742 12/961242 |
Document ID | / |
Family ID | 44857256 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110265742 |
Kind Code |
A1 |
Choi; Jae Young ; et
al. |
November 3, 2011 |
APPARATUS FOR CONTROLLING WATER PUMP OF HYBRID VEHICLE AND METHOD
THEREOF
Abstract
A water pump control apparatus and method of a hybrid vehicle
are used to control a motorized water pump according to the heat
emission amount of an engine. The apparatus and method include
calculating a temperature difference by detecting a temperature of
a coolant exhausted from an engine and a temperature of the coolant
flowing to an engine, calculating a heat emission amount of the
engine by applying a circulating coolant flux to the temperature
difference, and driving a motorized water pump with a driving power
in proportion to the heat emission amount of the engine.
Inventors: |
Choi; Jae Young; (Seoul,
KR) ; Ohn; Hyungseuk; (Hwaseong, KR) ; Min;
Byungsoon; (Seongnam, KR) ; Kim; Seok Joon;
(Yongin, KR) ; Lee; Jae Heon; (Hwaseong,
KR) |
Assignee: |
KIA MOTORS CORPORATION
Seoul
KR
HYUNDAI MOTOR COMPANY
Seoul
KR
|
Family ID: |
44857256 |
Appl. No.: |
12/961242 |
Filed: |
December 6, 2010 |
Current U.S.
Class: |
123/41.09 |
Current CPC
Class: |
F01P 2005/125 20130101;
F01P 2025/32 20130101; F01P 2003/028 20130101; F01P 2050/24
20130101; F01P 2025/36 20130101; F01P 7/161 20130101 |
Class at
Publication: |
123/41.09 |
International
Class: |
F01P 7/14 20060101
F01P007/14 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 29, 2010 |
KR |
10-2010-0040329 |
Claims
1. A water pump control apparatus of a hybrid vehicle, comprising:
a thermostat configured to determine a circulation direction of a
coolant according to a temperature of the coolant that is exhausted
from an engine; a motorized water pump mounted between the engine
and the thermostat for circulating the coolant; a first coolant
temperature sensor configured to detect the temperature of the
coolant flowing from the engine to a cooler; a second coolant
temperature sensor configured to detect a temperature of the
coolant flowing from the cooler to the engine; and a control
portion that applies a temperature difference detected by the first
and second coolant temperature sensors and a coolant flux to
calculate a heat emission amount of the engine, the control portion
configured to drive the motorized water pump according to the heat
emission amount.
2. The water pump control apparatus of claim 1, wherein the control
portion outputs a warning signal and simultaneously enters into a
limp home mode so as to continuously drive the motorized water pump
with a predetermined driving power such that the coolant
continuously circulates, if it is determined that the cooling
system is in an abnormal condition.
3. The water pump control apparatus of claim 1, wherein the control
portion drives the motorized water pump in proportion to the heat
emission amount of the engine, and the control portion determines
driving power in proportion to the heat emission amount of the
engine, calculates a compensation factor according to the coolant
temperature, and applies the compensation factor to the driving
power so as to drive the motorized water pump more rapidly in a
condition in which the coolant temperature is rising.
4. A water pump control method of a hybrid vehicle, comprising:
calculating a temperature difference by detecting a temperature of
a coolant exhausted from an engine, and a temperature of the
coolant flowing to an engine; calculating a heat emission amount of
the engine by applying a circulating coolant flux to the
temperature difference; and driving a motorized water pump with a
driving power in proportion to the heat emission amount of the
engine.
5. The water pump control method of claim 4, further comprising:
driving the motorized water pump with the driving power in
proportion to the heat emission amount if the coolant temperature
is steady; calculating a compensation factor according to the
coolant temperature; applying the compensation factor to the
driving power; and calculating a final driving power so as to drive
the motorized water pump more rapidly if the heat emission amount
and the coolant temperature are raised.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2010-0040329 filed in the Korean
Intellectual Property Office on Apr. 29, 2010, the entire contents
of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] The present invention relates to a water pump control
apparatus of a hybrid vehicle. More particularly, it relates to a
water pump control apparatus that controls a motorized water pump
according to a heat emission amount of an engine, and a control
method thereof.
[0004] (b) Description of the Related Art
[0005] Hybrid vehicles have been developed and mass produced in a
manner that satisfies exhaust gas regulations and enhances fuel
efficiency.
[0006] There are a variety of types of hybrid vehicles, and while
an engine and a motor are generally applied as a power source,
there are both EVs (electric vehicles) that are driven by only a
motor, and HEVs (hybrid electric vehicles) that are driven by an
engine and a motor.
[0007] In hybrid vehicles, a coolant is forcibly circulated so as
to prevent overheating of the engine, a coolant passage is formed
respectively in a cylinder block and a cylinder head of the engine,
and a water pump circulates the coolant through the coolant passage
so as to cool the engine.
[0008] Accordingly, fuel efficiency and exhaust gases can be
stabilized in a condition that the engine is warmed up. However, as
the warming period of the engine becomes longer, the fuel
efficiency may suffer and the exhaust gas quality is
deteriorated.
[0009] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0010] In one aspect, according to the present invention, a water
pump control apparatus of a hybrid vehicle is provided that is
capable of optimizing cooling efficiency by controlling the
motorized water pump according to the heat emission amount of the
engine.
[0011] A water pump control apparatus of a hybrid vehicle according
to an exemplary embodiment of the present invention preferably
includes at least a thermostat configured to determine a
circulation direction of a coolant according to a temperature of
the coolant that is exhausted from an engine, a motorized water
pump mounted between the engine and the thermostat for circulating
the coolant, a first coolant temperature sensor configured to
detect the temperature of the coolant flowing from the engine to a
cooler, a second coolant temperature sensor configured to detect a
temperature of the coolant flowing from the cooler to the engine,
and a control portion that applies a temperature difference
detected by the first and second coolant temperature sensors and a
coolant flux to calculate a heat emission amount of the engine, and
thus drive the motorized water pump according to the heat emission
amount.
[0012] The control portion may output a warning signal and
simultaneously enter into a limp home mode so as to continuously
drive the motorized water pump with a predetermined driving power
such that the coolant continuously circulates, if it is determined
that the cooling system is in an abnormal condition.
[0013] The control portion may determine driving power and drive
the motorized water pump in proportion to the heat emission amount
of the engine by calculating a compensation factor according to the
coolant temperature and applying the compensation factor to the
driving power so as to drive the motorized water pump more rapidly
in a condition in which the coolant temperature is rising.
[0014] A water pump control method of a hybrid vehicle according to
an exemplary embodiment of the present invention may include
calculating a temperature difference by detecting the temperature
of a coolant exhausted from an engine and the temperature of the
coolant flowing to an engine, calculating a heat emission amount of
the engine by applying a circulating coolant flux to the
temperature difference, and driving a motorized water pump with a
driving power in proportion to the heat emission amount of the
engine.
[0015] The water pump control method may further include driving
the motorized water pump with driving power in proportion to the
heat emission amount if the coolant temperature is steady, and
calculating a compensation factor according to the coolant
temperature, applying the compensation factor to the driving power,
and calculating final driving power so as to drive the motorized
water pump more rapidly if the heat emission amount and the coolant
temperature are raised.
[0016] The present invention as stated above preferably drives the
motorized water pump in proportion to the heat emission amount of
the hybrid vehicle engine to optimally circulate the coolant such
that hot spots of the engine are reduced, stability thereof is
improved, and engine efficiency is improved by optimized
cooling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic diagram of a water pump control
apparatus of a hybrid vehicle according to an exemplary embodiment
of the present invention.
[0018] FIG. 2 is a flowchart depicting a water pump control process
of a hybrid vehicle according to an exemplary embodiment of the
present invention.
[0019] FIG. 3 is a graph showing water pump control timing of a
hybrid vehicle according to an exemplary embodiment of the present
invention.
DESCRIPTION OF SYMBOLS
[0020] 100: engine
[0021] 110: first coolant temperature sensor
[0022] 120: the second temperature sensor
[0023] 130: radiator
[0024] 140: thermostat
[0025] 150: motorized water pump
[0026] 160: control portion
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] Hereinafter, in the following detailed description, only
certain exemplary embodiments of the present invention have been
shown and described, simply by way of illustration.
[0028] As those skilled in the art would realize, the described
embodiments may be modified in various different ways, all without
departing from the spirit or scope of the present invention, and
the drawings and description are to be regarded as illustrative in
nature and not restrictive.
[0029] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g. fuels derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example both
gasoline-powered and electric-powered vehicles.
[0030] FIG. 1 is a schematic diagram of a water pump control
apparatus of a hybrid vehicle according to an exemplary embodiment
of the present invention.
[0031] As shown in FIG. 1, the present invention preferably
includes an engine 100 as a power source, a first coolant
temperature sensor 110, a second coolant temperature sensor 120, a
radiator 130, a thermostat 140, a motorized water pump 150, and a
control portion 150.
[0032] The first coolant temperature sensor 110 detects a
temperature of a coolant circulating from the engine 100 to the
radiator (cooler) 130 and transfers the detected signal to the
control portion 160.
[0033] The second coolant temperature sensor 120 detects a
temperature of the coolant circulating from the radiator (cooler)
130 or a bypass line to the engine 100 and transfers the detected
signal to the control portion 160.
[0034] The core of the radiator 130 preferably has a wide contact
surface with air to effectively radiate heat absorbed in the
coolant, and a cooling fan (not shown) is set to forcibly blow air
through the core so as to improve the radiating efficiency
according to the coolant temperature and the driving conditions of
the vehicle.
[0035] The thermostat 140 is configured to change the circulation
direction of the coolant exhausted from the engine 100 to the
bypass line or the radiator 130 according to the coolant
temperature.
[0036] The motorized water pump 150 preferably is disposed between
the engine 100 and the thermostat 140, where the control portion
160 turns the motorized water pump 150 off or on or varies a
driving power for driving the motorized water pump 150 so as to
vary the coolant flow amount. The motorized water pump 150 can be
one of a clutch-type water pump and an electrical water pump.
[0037] The control portion 160 calculates a heat emission amount as
a cooling demand according to driving of the engine 100, and
controls driving power for driving the motorized water pump 150 in
proportion to the heat emission amount.
[0038] The control portion 160 detects the coolant temperature of
the coolant flowing from the engine 100 to the cooler through the
first coolant temperature sensor 110, detects the coolant
temperature of the coolant flowing from the cooler to the engine
100 through the second coolant temperature sensor 120, calculates
the temperature difference between them, and multiplies the
temperature difference by the coolant flow amount (flux)
circulating between the engine 100 and the cooler to calculate the
heat emission amount of the engine 100, for example, according to
the following formula:
Q (heat emission amount)=m (flux).times.c (specific
heat).times..DELTA.T (temperature difference)
[0039] The heat emission amount of the engine 100 can be determined
by utilizing experimental data according to car models, and can be
expressed as two-dimensional map data.
[0040] The control portion 160 is configured to analyze driving
conditions and environmental conditions such as outside
temperature, engine speed, and an ISG (idle stop and go) state, and
if it is determined that the cooling system is in error, the
control portion 160 outputs an alarm signal and simultaneously
enters is into a limp home mode such that the motorized water pump
150 can be continuously operated.
[0041] In a case that the heat emission amount of the engine 100 is
sharply increased, the control portion 160 increases the driving
power for driving the motorized water pump 150 so as to decrease a
hot spot of the engine 100, because the engine 100 can be
vulnerable at a high temperature compared to a low temperature.
[0042] For instance, if the heat emission amount is increased in a
condition that the coolant temperature is steady, the control
portion 160 drives the motorized water pump 150 in proportion to
the heat emission amount, and if the heat emission amount and the
coolant temperature are increased, the control portion 160
determines a driving power in proportion to the heat emission
amount, multiples a compensation factor by the driving power to
calculate final driving power, and drives the motorized water pump
150 with the final driving power.
[0043] Operation of a water pump control apparatus according to the
present invention including the functions described above will
hereinafter be described in detail with reference to FIG. 2, which
is a flowchart that depicts a water pump control process according
to an exemplary embodiment of the present invention.
[0044] The control portion 160 can diagnose driving conditions and
environmental conditions from sensors in a hybrid vehicle in step
5101, diagnose a cooling system in step S102, and determine whether
the cooling system is in a normal condition or not in step
S103.
[0045] If it is determined that the cooling system is in an
abnormal condition in step S103, the control portion 160 outputs an
alarm signal in a predetermined form, enters into a limp home mode
in step S113, and drives the motorized water pump 150 with a
predetermined driving amount so as to continuously circulate the
coolant in step S114.
[0046] Meanwhile, if it is determined that the cooling system is in
a normal condition in step S103, the control portion 160 detects
the temperature of the coolant circulating from the engine 100 to
the cooler through the first coolant temperature sensor 110 and
detects the temperature of the coolant circulating from the cooler
to the engine 100 through the second coolant temperature sensor
110, and calculates a temperature difference between them in step
S104.
[0047] The control portion 160 multiplies the temperature
difference by the coolant flowing amount (flux) circulating between
the engine 100 and the cooler to calculate the heat emission amount
of the engine 100 in step 105.
[0048] It is determined whether the heat emission amount of the
engine 100 exceeds a predetermined value necessary to circulate the
coolant in step S106.
[0049] If the heat emission amount of the engine 100 is less than
the predetermined value in S106, the control portion 160 stops
operation of the motorized water pump 150 so as to not circulate
the coolant in the S107.
[0050] However, if it is determined that the heat emission amount
of the engine 100 is greater than the predetermined value in the
S106, the control portion 160 determines a driving power that is
proportional to the heat emission amount of the engine 100 and
drives the motorized water pump 150 with the driving power such
that the coolant effectively cools the engine in step S109.
[0051] While the control portion drives the motorized water pump
150 in proportion to the heat emission amount of the engine 100,
the heat emission amount of the engine 100 and the coolant
temperature are raised and it is determined whether the coolant
temperature detected from the first coolant temperature sensor 110
exceeds a predetermined temperature (A.degree. C.) in step
S110.
[0052] The predetermined temperature (A.degree. C.) can be changed
according to an operating load, and is generally set as a value
ranging from about 85.degree. C. to about 95.degree. C.
[0053] If the coolant temperature does not exceed the predetermined
temperature (A.degree. C.) in step S110, it is returned to step
S108 and the motorized water pump 150 is driven with driving power
that is proportional to the heat emission amount.
[0054] However, if the coolant temperature exceeds the
predetermined temperature (A.degree. C.) in step S110, the control
portion determines a driving power that is proportional to the heat
emission amount of the engine 100, applies a coefficient factor
according to the coolant temperature to the driving power to
extract the final driving power in step S111, and the control
portion 160 drives the motorized water pump 150 with the final
driving power so as to quickly circulate the coolant.
[0055] FIG. 3 is a graph showing a water pump control timing of a
hybrid vehicle according to an exemplary embodiment of the present
invention. As shown in FIG. 3, the motorized water pump is driven
in proportion to the heat emission amount of the engine in a
section where the coolant temperature is steady, if the heat
emission amount and the coolant temperature continuously rise, the
coefficient factor according to the heat emission amount and the
coolant temperature is applied to drive the motorized water pump at
a higher load.
[0056] Accordingly, the coolant can circulate corresponding to the
cooling demand of the engine such that the hot spot inside the
engine is decreased and the engine is not overcooled to improve the
efficiency thereof.
[0057] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims,
* * * * *