U.S. patent application number 12/953264 was filed with the patent office on 2012-03-01 for system for controlling hydraulic pressure and flow rate of oil in engine and control method thereof.
This patent application is currently assigned to Kia Motors Corporation. Invention is credited to Youngrock Chung.
Application Number | 20120048228 12/953264 |
Document ID | / |
Family ID | 45566296 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120048228 |
Kind Code |
A1 |
Chung; Youngrock |
March 1, 2012 |
SYSTEM FOR CONTROLLING HYDRAULIC PRESSURE AND FLOW RATE OF OIL IN
ENGINE AND CONTROL METHOD THEREOF
Abstract
A system for controlling hydraulic pressure and flow rate of oil
in an engine, may include a first solenoid valve disposed in a
channel connecting an inlet and an outlet of an oil pump supplying
oil from an oil pan to the engine, and an electronic controller
controlling the first solenoid valve on the basis of number of
revolution of the engine, load of the engine, and temperature of
the oil.
Inventors: |
Chung; Youngrock;
(Yongin-si, KR) |
Assignee: |
Kia Motors Corporation
Seoul
KR
Hyundai Motor Company
Seoul
KR
|
Family ID: |
45566296 |
Appl. No.: |
12/953264 |
Filed: |
November 23, 2010 |
Current U.S.
Class: |
123/196R |
Current CPC
Class: |
F01M 1/16 20130101; F01M
5/005 20130101; F01M 1/08 20130101 |
Class at
Publication: |
123/196.R |
International
Class: |
F01M 1/02 20060101
F01M001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2010 |
KR |
10-2010-0084694 |
Claims
1. A system for controlling hydraulic pressure and flow rate of oil
in an engine, comprising: a first solenoid valve disposed in a
channel connecting an inlet and an outlet of an oil pump supplying
oil from an oil pan to the engine; and an electronic controller
controlling the first solenoid valve on the basis of number of
revolution of the engine, load of the engine, and temperature of
the oil.
2. The system for controlling hydraulic pressure and flow rate of
oil in the engine as defined in claim 1, further comprising a
second solenoid valve disposed in a channel connecting an inlet and
an outlet of an oil cooler connected to the oil pump so as to cool
the oil at the outlet of the oil pump, and controlled to operate by
the electronic controller.
3. The system for controlling hydraulic pressure and flow rate of
oil in the engine as defined in claim 1, further comprising a third
solenoid valve disposed in a channel connecting the oil pump to a
piston cooling gallery supplying the oil discharged through the
outlet of the oil pump to a piston cooling jet disposed to
distribute the oil to pistons, and controlled by the electronic
controller to control flow rate of the oil to the piston cooling
gallery.
4. The system for controlling hydraulic pressure and flow rate of
oil in the engine as defined in claim 1, further comprising a
fourth solenoid valve disposed in a channel connecting the oil pump
to a head oil gallery supplying the oil discharged through the
outlet of the oil pump to a cylinder head, and controlled by the
electronic controller to control flow rate of the oil supplied to
the head oil gallery.
5. A system for controlling hydraulic pressure and flow rate of oil
in an engine, comprising: a first solenoid valve disposed in a
channel connecting an inlet and an outlet of an oil pump supplying
oil from an oil pan to the engine; a second solenoid valve disposed
in a channel connecting an inlet and an outlet of an oil cooler
connected with the outlet of the oil pump and cooling the oil
discharged from the oil pump; a third solenoid valve disposed in a
channel formed between an oil filter and a piston cooling gallery
supplying the oil to piston cooling jets such that the oil is
distributed to pistons, and controlling flow rate of the oil to the
piston cooling gallery; a fourth solenoid valve disposed in a
channel formed between the oil filter and a head oil gallery
supplying the oil filtered through the oil filter connected with
the oil cooler to a cylinder head, and controlling flow rate of the
oil supplied to the head oil gallery; and an electronic controller
controlling the first solenoid valve, the second solenoid valve,
the third solenoid valve, and the fourth solenoid valve, on the
basis of engine parameters including number of revolution of the
engine, load of the engine, and temperature of the oil.
6. The system for controlling hydraulic pressure and flow rate of
oil in the engine as defined in claim 1, wherein the electronic
controller controls the first solenoid valve to control the oil
supplied to a main oil gallery of the engine, in accordance with
operations of the second solenoid valve, the third solenoid valve,
and the fourth solenoid valve.
7. A method of controlling a system for controlling hydraulic
pressure and flow rate of oil in an engine, comprising the steps
of: sensing engine parameters including number of revolution of the
engine, load of the engine, and oil temperature by using sensors in
a vehicle; controlling a second solenoid valve that controls flow
rate supplied to an oil cooler connected to an oil pump when the
sensed engine parameters are lower or higher than reference values
of the engine parameters; controlling a third solenoid valve that
controls flow rate supplied to a piston cooling gallery from the
oil pump when the sensed engine parameters are lower or higher than
reference values of the engine parameters; controlling a fourth
solenoid valve that controls flow rate supplied to a head gallery
from the oil pump on the basis of the sensed parameters; and
controlling a first solenoid valve that controls flow rate supplied
to a main gallery from the oil pump on the basis of operational
states of the second solenoid valve, the third solenoid valve, and
the fourth solenoid valve, and the sensed parameters.
8. The method of controlling a system for controlling hydraulic
pressure and flow rate of oil in an engine as defined in claim 1,
wherein one of the sensed engine parameters in controlling the
second solenoid valve is oil temperature.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to Korean Patent
Application Number 10-2010-0084694 filed Aug. 31, 2010, the entire
contents of which application is incorporated herein for all
purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system for controlling
hydraulic pressure and flow rate of oil in an engine and a control
method thereof, and more particularly, to a system for controlling
hydraulic pressure and flow rate of oil in an engine that can
prevent frictional loss due to hydraulic pressure and unnecessary
consumption of oil, by controlling the opening of a solenoid valve
mounted in each channel in accordance with the speed and load of
the engine and temperature of the oil to supply oil corresponding
to the minimum flow rate required by each gallery, and a control
method thereof.
[0004] 2. Description of Related Art
[0005] In general, in vehicles, fuel and air flow into the
combustion chamber of the engine and then are compressed and
exploded, such that the pistons in the engine reciprocates up/down
and the up-down reciprocation of the pistons is converted into
rotation of the crankshaft, thereby achieving torque.
[0006] The parts in the engine make friction therebetween when
generating power and the friction of the parts may reduce the power
and decrease the life span of the engine.
[0007] Further, heat is generated with combustion in the combustion
chambers by the pistons in the engine and the inside of the engine
is cooled by supplying oil into the engine. The oil pump that
supplies the oil into the engine operates in proportion to the
operational speed of the engine. The oil discharged from the oil
pump is supplied to the main and head gallery of the engine through
an oil cooler for cooling and an oil filter for filtering.
[0008] However, the oil pressure is different at the oil pump and
at the main and head gallery due to hydraulic pressure loss
generated through the oil cooler or the oil filter or flow
restrictors. The oil pressure should be set high at the oil pump in
order to achieve the desired oil pressure at the main and head
gallery.
[0009] Therefore, it is required to increase very high oil pressure
at the oil pump to supply hydraulic pressure corresponding to the
desired hydraulic pressure at each gallery, and accordingly,
friction increases at the oil pump. According to the engine
operating condition, the required oil flow at the branched oil
consumption parts are varied. However, the oil flow delivered to
those is mostly proportional to the engine speed at the engine.
This makes excessive oil should be delivered at the normal engine
operating condition in order to meet the minimum required oil flow
at all the branched parts. This means oil pumping work should be
high and hydraulic pressure loss increase at the oil pump, the oil
cooler, and the oil filter and oil consumption is increased by
unnecessarily supplying the oil.
[0010] The information disclosed in this Background of the
Invention 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.
BRIEF SUMMARY OF THE INVENTION
[0011] Various aspects of the present invention are directed to
provide a system for controlling hydraulic pressure and flow rate
of oil in an engine that can prevent frictional loss due to
hydraulic pressure and unnecessary consumption of oil, by
controlling the opening of a solenoid valve mounted in each channel
in accordance with the speed and load of the engine and temperature
of the oil to supply oil corresponding to the minimum flow rate
required by each gallery, and a control method thereof.
[0012] In an aspect of the present invention, the system for
controlling hydraulic pressure and flow rate of oil in an engine,
may include a first solenoid valve disposed in a channel connecting
an inlet and an outlet of an oil pump supplying oil from an oil pan
to the engine, and an electronic controller controlling the first
solenoid valve on the basis of number of revolution of the engine,
load of the engine, and temperature of the oil.
[0013] The system for controlling hydraulic pressure and flow rate
of oil in the engine may further include a second solenoid valve
disposed in a channel connecting an inlet and an outlet of an oil
cooler connected to the oil pump so as to cool the oil at the
outlet of the oil pump, and controlled to operate by the electronic
controller.
[0014] The system for controlling hydraulic pressure and flow rate
of oil in the engine may further may include a third solenoid valve
disposed in a channel connecting the oil pump to a piston cooling
gallery supplying the oil discharged through the outlet of the oil
pump to a piston cooling jet disposed to distribute the oil to
pistons, and controlled by the electronic controller to control
flow rate of the oil to the piston cooling gallery.
[0015] The system for controlling hydraulic pressure and flow rate
of oil in the engine may further include a fourth solenoid valve
disposed in a channel connecting the oil pump to a head oil gallery
supplying the oil discharged through the outlet of the oil pump to
a cylinder head, and controlled by the electronic controller to
control flow rate of the oil supplied to the head oil gallery.
[0016] In another aspect of the present invention, the system for
controlling hydraulic pressure and flow rate of oil in an engine,
may include a first solenoid valve disposed in a channel connecting
an inlet and an outlet of an oil pump supplying oil from an oil pan
to the engine, a second solenoid valve disposed in a channel
connecting an inlet and an outlet of an oil cooler connected with
the outlet of the oil pump and cooling the oil discharged from the
oil pump, a third solenoid valve disposed in a channel formed
between an oil filter and a piston cooling gallery supplying the
oil to piston cooling jets such that the oil may be distributed to
pistons, and controlling flow rate of the oil to the piston cooling
gallery, a fourth solenoid valve disposed in a channel formed
between the oil filter and a head oil gallery supplying the oil
filtered through the oil filter connected with the oil cooler to a
cylinder head, and controlling flow rate of the oil supplied to the
head oil gallery, and an electronic controller controlling the
first solenoid valve, the second solenoid valve, the third solenoid
valve, and the fourth solenoid valve, on the basis of engine
parameters including number of revolution of the engine, load of
the engine, and temperature of the oil, wherein the electronic
controller controls the first solenoid valve to control the oil
supplied to a main oil gallery of the engine, in accordance with
operations of the second solenoid valve, the third solenoid valve,
and the fourth solenoid valve.
[0017] In further another aspect of the present invention, the
method of controlling a system for controlling hydraulic pressure
and flow rate of oil in an engine may include the steps of sensing
engine parameters including number of revolution of the engine,
load of the engine, and oil temperature by using sensors in a
vehicle, controlling a second solenoid valve that controls flow
rate supplied to an oil cooler connected to an oil pump when the
sensed engine parameters may be lower or higher than reference
values of the engine parameters, controlling a third solenoid valve
that controls flow rate supplied to a piston cooling gallery from
the oil pump when the sensed engine parameters may be lower or
higher than reference values of the engine parameters, controlling
a fourth solenoid valve that controls flow rate supplied to a head
gallery from the oil pump on the basis of the sensed parameters,
and controlling a first solenoid valve that controls flow rate
supplied to a main gallery from the oil pump on the basis of
operational states of the second solenoid valve, the third solenoid
valve, and the fourth solenoid valve, and the sensed parameters,
wherein one of the sensed engine parameters in controlling the
second solenoid valve may be oil temperature.
[0018] A system for controlling hydraulic pressure and flow rate of
oil in an engine and a control method thereof according to the
present invention make it possible to prevent frictional loss due
to hydraulic pressure and unnecessary consumption of oil, by
controlling the opening of a solenoid valve mounted in each channel
in accordance with the speed and load of the engine and temperature
of the oil to supply oil corresponding to the minimum flow rate
required by each gallery.
[0019] 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 of the
Invention, which together serve to explain certain principles of
the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a diagram illustrating a system for controlling
hydraulic pressure and flow rate of oil in an engine according to
an exemplary embodiment of the present invention.
[0021] FIG. 2 is a flowchart illustrating a control method of the
system for controlling hydraulic pressure and flow rate of oil in
an engine shown in FIG. 1.
[0022] 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.
[0023] 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 OF THE INVENTION
[0024] 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.
[0025] Referring to FIG. 1, in a system for supplying oil into the
engine, as the engine starts, an oil pump 12 pumps up oil from an
oil pan 11 connected with the inlet and discharges the oil through
the outlet. The oil is sent under predetermined pressure to an oil
cooler 13 connected with the outlet of oil pump 12 and cooled
through oil cooler 13. The oil cooled through oil cooler 13 is
filtered through an oil filter 14 and supplied to a main oil
gallery 16 in the cylinder block of the engine.
[0026] The oil supplied to main oil gallery 16 is supplied to each
main bearing journals of the cylinder block.
[0027] The oil filtered through oil filter 14 is supplied to a head
oil gallery 15 in the cylinder head of the engine. The oil supplied
to head oil gallery 15 is supplied to the locker shaft of the
cylinder head and into the cylinder head.
[0028] The oil filtered through oil filter 14 is supplied to a
piston cooling gallery 17 in the cylinder block of the engine. The
oil supplied to piston cooling gallery 17 is supplied to each
piston through a plurality of piston cooling jet 18.
[0029] A system 100 for controlling hydraulic pressure and flow
rate of oil in an engine includes a first solenoid valve Vs1 in the
channel connecting the inlet with the outlet of oil pump 12, such
that it can prevent hydraulic pressure from excessively increasing
at the outlet of oil pump 12 by controlling the opening of the
channel between the inlet and the outlet of oil pump 12, in
accordance with the oil temperature and the vehicle speed. First
solenoid valve Vs1 is electrically connected with an electronic
controller 110 and controlled to operate by the electronic
controller 110.
[0030] Oil pump 12 operates in proportion to the engine speed, and
even if oil pump 12 operates at the same speed, the hydraulic
pressure is high when the oil temperature is low and the hydraulic
pressure is relatively low when the oil temperature is high, as
compared with when the oil temperature is low.
[0031] Therefore, electronic controller 110 controls first solenoid
valve Vs1 such that the hydraulic pressure from oil pump 12 is
controlled in accordance with the oil temperature and the vehicle
speed, in order to prevent the pressure of the oil discharged from
oil pump 12, which operates in proportion to the engine speed, from
increasing when the oil temperature is low.
[0032] That is, electronic controller 110 controls first solenoid
valve Vs1 such that desired hydraulic pressure required for main
oil gallery 16 is supplied, in accordance with the engine speed and
the engine load in the cold period where the oil temperature is
low.
[0033] Further, system 100 for controlling hydraulic pressure and
flow rate of oil in an engine further includes a second solenoid
valve Vs2 between the inlet and the outlet of oil cooler 13. That
is, second solenoid valve Vs2 controls flow rate in the channel
connecting the outlet of oil pump 12 and the inlet of oil filter
14.
[0034] Second solenoid valve Vs2 is controlled to open the channel
between the inlet and the outlet of oil cooler 13 by electronic
controller 110 in accordance with the oil temperature such that the
oil discharged from oil pump 12 is directly supplied to oil filter
14, without being cooled through oil cooler 13.
[0035] As described above, electronic controller 110 can prevent
pressure loss through oil cooler 13 by opening second solenoid
valve Vs2 such that the oil discharged from oil pump 12 is directly
supplied to oil filter 14, without operating oil cooler 13, when
the oil temperature is low.
[0036] Further, system 100 for controlling hydraulic pressure and
flow rate of oil in an engine further includes a third solenoid
valve Vs3 between the outlet of oil filter 14 and piston cooling
gallery 17.
[0037] Third solenoid valve Vs3 controls the amount of oil supplied
to piston cooling gallery 17 on the basis of the number of
revolution of engine, the engine load, and the oil temperature.
[0038] Third solenoid valve Vs3 controls unnecessary excessive
supply of oil to a piston cooling jet 18, while the vehicle travels
at a low speed, on the basis of the number of revolution of engine,
the engine load, and the oil temperature. The engine load may be
determined from the position of the driving gear of the vehicle,
the amount of fuel, and the temperature of cooling water.
[0039] Electronic controller 110 can prevent oil supply to piston
cooling gallery 17 by closing third solenoid valve Vs3 while the
vehicle travels at a low speed under a predetermined speed.
[0040] Since the larger the flow rate of the oil supplied to piston
cooling gallery 17 through third solenoid valve Vs3, the more the
hydraulic pressure decreases at the outlet of oil pump 12, under
the same engine speed and the same oil temperature, electronic
controller 110 controls the hydraulic pressure at the outlet of oil
pump 12 by operating third solenoid valve Vs3 in accordance with
the vehicle speed and the oil temperature.
[0041] Further, system 100 for controlling hydraulic pressure and
flow rate of oil in an engine further includes a fourth solenoid
valve Vs4 between the outlet of oil filter 14 and head oil gallery
15.
[0042] Fourth solenoid valve Vs4 controls the amount of oil
supplied to head oil gallery 15 on the basis of the revolution
number of engine, the engine load, and the oil temperature.
[0043] The opening of fourth solenoid valve Vs4 is controlled by
electronic controller 110 on the basis of the number of revolution
of engine, the engine load, and the oil temperature, to supply the
minimum amount of oil required for head oil gallery 15. The engine
load may be determined from the position of the driving gear of the
vehicle, the amount of fuel, and the temperature of cooling
water.
[0044] Further, the smaller the opening of fourth solenoid valve
Vs4, the more the hydraulic pressure applied to main oil gallery 16
decreases. Further, with second solenoid valve Vs2 open, the
hydraulic pressure applied to main oil gallery 16 decreases, while
the smaller the opening of third solenoid valve Vs3, the more the
hydraulic pressure applied to main oil gallery 16 decreases.
[0045] Therefore, electronic controller 110 controls the opening of
first solenoid valve Vs1 to prevent the flow rate to main oil
gallery 16 from decreasing, in accordance with the opening of
second solenoid valve Vs2, third solenoid valve Vs3, and fourth
solenoid valve Vs4, thereby re-compensating the flow rate from oil
pump 12 to the desired flow rate.
[0046] Although all of first solenoid valve Vs1, second solenoid
valve Vs2, third solenoid valve Vs3, and fourth solenoid valve Vs4
of system 100 for controlling hydraulic pressure and flow rate of
oil in an engine is shown in FIG. 1, at least only any one of
solenoid valves Vs1, Vs2, Vs3, and Vs4 may be included, for the
features of the engine of the vehicle.
[0047] As described above, since first solenoid valve Vs1, second
solenoid valve Vs2, third solenoid valve Vs3, and fourth solenoid
valve Vs4 are controlled by electronic controller 110 in accordance
with the engine speed, the engine load, and the oil temperature, in
system 100 for controlling hydraulic pressure and flow rate of oil
in an engine, it is possible to supply flow rate corresponding to
the desired minimum flow rate required for each gallery. Therefore,
it is possible to reduce frictional pressure applied to the oil
pump and improve fuel efficiency by preventing unnecessarily
excessive flow rate and frictional loss due to the increase of
hydraulic pressure.
[0048] On the other hand, a method of controlling system 100 for
controlling hydraulic pressure and flow rate of oil in an engine
show in FIG. 1 includes measuring parameters (S1), controlling
second solenoid valve (S2), controlling third solenoid valve (S3),
controlling fourth solenoid valve (S4), and controlling first
solenoid valve (S5), as shown in FIG. 2. The method of controlling
system 100 for controlling hydraulic pressure and flow rate of oil
in an engine is described with reference to system 100 for
controlling hydraulic pressure and flow rate of oil in an engine
shown in FIG. 1.
[0049] Sensing parameters transmitting parameters measured by
sensors of the vehicle to electronic controller 110 (S1) is first
performed to measure the number of revolution of engine, the engine
load, and the oil temperature. The engine load may be determined
from the position of the driving gear of the vehicle, the amount of
fuel, and the temperature of cooling water.
[0050] Electronic controller 110 performs the controlling of
solenoid valves for controlling solenoid valves Vs1, Vs2, Vs3, and
Vs4 (S2, S3, S4, and S5) after comparing the transmitted parameter
values Pa with reference values.
[0051] Electronic controller 110 determines whether the sensed oil
temperature To is smaller than a reference temperature A to perform
the controlling of second solenoid valve (S2) (S21). Electronic
controller 110 closes second solenoid valve Vs2 (S23) to supply the
oil cooled through oil cooler 13 to oil filter 14, when determining
that the oil temperature To is higher than the reference
temperature A.
[0052] Electronic controller 110 can prevent the pressure from
being reduced by oil cooler 13 by opening second solenoid valve Vs2
(S22) such that the oil bypasses, without operating oil cooler 13,
when the oil temperature To is smaller than the reference
temperature A. Electronic controller 110 controls the flow rate to
main oil gallery 16 by controlling second solenoid valve Vs2 on the
basis of the amount of opening estimated from parameter values
19.
[0053] Further, electronic controller 110 compares the parameter
values Pa transmitted to perform the controlling of third solenoid
valve (S3) with reference values Th (S31).
[0054] For example, electronic controller 110 determines that the
vehicle is traveling at a low speed, and prevents the oil supply to
piston cooling gallery 17 by closing third solenoid valve Vs3
(S32), when the number of revolution of engine in the parameter
values Pa is less than the reference number of revolution Th.
[0055] Electronic controller 110 controls the amount of opening of
third solenoid valve such that the desired flow rate required by
piston cooling gallery 17 in accordance with the number of
revolution of engine, the engine load, and the oil temperature is
supplied, when the parameter values Pa are larger than the
reference values.
[0056] Electronic controller 110 controls the amount of opening of
fourth solenoid valve Vs4 (S4) to supply the desired flow rate
required for head oil gallery 15 in accordance with the number of
revolution of engine, the engine load, and the oil temperature,
which are the parameter values Pa, in order to perform the
controlling of fourth solenoid valve.
[0057] Electronic controller 110 calculates the amount of opening
of first solenoid valve Vs1 for supplying the desired flow rate
required for main oil gallery 16 (S51), in accordance with the
operational states of second solenoid valve Vs2, third solenoid
valve Vs3, and fourth solenoid valve Vs4, and the number of
revolution of engine, the engine load, and the oil temperature,
which are the parameter values Pa, in order to perform the
controlling of fifth solenoid valve (S5). Further, electronic
controller 110 controls first solenoid valve Vs1 to be opened as
much as the calculated amount of opening of first solenoid valve
Vs1 (S52).
[0058] As described above, since first solenoid valve Vs1, second
solenoid valve Vs2, third solenoid valve Vs3, and fourth solenoid
valve Vs4 are controlled by electronic controller 110 in accordance
with the engine speed, the engine load, and the oil temperature, in
the method of controlling system 100 for controlling hydraulic
pressure and flow rate of oil in an engine, it is possible to
supply flow rate corresponding to the desired minimum flow rate
required for each gallery. Therefore, it is possible to reduce
frictional pressure applied to the oil pump and improve fuel
efficiency by preventing unnecessarily excessive flow rate and
frictional loss due to the increase of hydraulic pressure.
[0059] The above description is an embodiment for implementing a
system for controlling hydraulic pressure and flow rate of oil in
an engine and a control method thereof of the present invention and
the present invention is not limited thereto. Accordingly, the
present invention may be modified in various ways by those skilled
in the art without departing from the scope of the present
invention, which is described in the following claims, and the
modifications should be construed as being included in the present
invention.
* * * * *