U.S. patent application number 15/949732 was filed with the patent office on 2018-10-18 for cooling apparatus of internal combustion engine.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Rentaro Kuroki, Ryo Michikawauchi, Yuji Miyoshi, Yasuhiko SUGIURA.
Application Number | 20180298808 15/949732 |
Document ID | / |
Family ID | 63792055 |
Filed Date | 2018-10-18 |
United States Patent
Application |
20180298808 |
Kind Code |
A1 |
SUGIURA; Yasuhiko ; et
al. |
October 18, 2018 |
COOLING APPARATUS OF INTERNAL COMBUSTION ENGINE
Abstract
A cooling apparatus of an internal combustion engine according
to the invention comprises a first passage formed in the cylinder
block, through which the cooling medium flows for cooling
between-bores portions, a second passage formed in the cylinder
block, through which the cooling medium flows for cooling a
bore-surrounding portion, and a cooling medium supplying mechanism
for supplying the cooling medium to the first and second passages
such that ability of the cooling medium for cooling the
between-bore portions, is different from the ability of the cooling
medium for cooling the bore-surrounding portion.
Inventors: |
SUGIURA; Yasuhiko;
(Susono-shi, JP) ; Kuroki; Rentaro; (Susono-shi,
JP) ; Michikawauchi; Ryo; (Numazu-shi, JP) ;
Miyoshi; Yuji; (Susono-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
63792055 |
Appl. No.: |
15/949732 |
Filed: |
April 10, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01P 2003/028 20130101;
F01P 2003/021 20130101; F01P 7/165 20130101; F01P 2007/146
20130101; F01P 3/02 20130101; F01P 2003/024 20130101 |
International
Class: |
F01P 7/16 20060101
F01P007/16; F01P 3/02 20060101 F01P003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2017 |
JP |
2017-080195 |
Claims
1. A cooling apparatus of an internal combustion engine for cooling
a cylinder block of the internal combustion engine and a cylinder
head mounted on the cylinder block by cooling medium, comprising: a
first passage formed in the cylinder block, through which the
cooling medium flows for cooling between-bores portions each
corresponding to a portion of the cylinder block surrounding and
between adjacent cylinder bores formed in the cylinder block; a
second passage formed in the cylinder block, through which the
cooling medium flows for cooling a bore-surrounding portion
corresponding to a portion of the cylinder block surrounding the
cylinder bores other than the between-bores portions; and a cooling
medium supplying mechanism for supplying the cooling medium to the
first and second passages such that ability of the cooling medium
for cooling the between-bore portions, is different from the
ability of the cooling medium for cooling the bore-surrounding
portion.
2. The cooling apparatus according to claim 1, wherein the cooling
medium supplying mechanism includes a head passage formed in the
cylinder head, through which the cooling medium flows for cooling
the cylinder head, and the first passage is connected to the head
passage.
3. The cooling apparatus according to claim 1, wherein the cooling
medium supplying mechanism includes: a common passage communicated
with the first and second passages; and a flow rate control valve
for controlling a flow rate of the cooling medium supplied to the
second passage via the common passage.
4. The cooling apparatus according to claim 1, wherein the cooling
medium supplying mechanism includes: a first cooling device for
cooling the cooling medium supplied to the first passage; and a
second cooling device for cooling the cooling medium supplied to
the second passage, and ability of the first cooling device of
cooling the cooling medium is larger than the ability of the second
cooling device of cooling the cooling medium.
Description
BACKGROUND
Field
[0001] The invention relates to a cooling apparatus of an internal
combustion engine for cooling the internal combustion engine by
cooling water.
Description of the Related Art
[0002] There is known a cooling apparatus of an internal combustion
engine for cooling a cylinder head and a cylinder block of the
internal combustion engine by cooling water (for example, see JP
62-99616 A). The known cooling apparatus includes cooing water
passages formed in the cylinder head and the cylinder block.
[0003] The cooling water passage formed in the cylinder head is
separated from the cooling water passage formed in the cylinder
block. Hereinafter, the cooling water passage formed in the
cylinder head will be referred to as "the head water passage", and
the cooling water passage formed in the cylinder block will be
referred to as "the block water passage".
[0004] In the field of the engine, friction resistances of movable
parts such as pistons of the engine are requested to be decreased.
In order to decrease the friction resistances, it is necessary to
maintain a temperature of portions of the cylinder block around
cylinder bores at a temperature range capable of decreasing the
friction resistances.
[0005] An amount of heat that between-bores portions (i.e. portions
of the cylinder block between the adjacent cylinder bores) is
received from combustion in combustion chambers of the engine, is
larger than the amount of heat that bore-surrounding portion (i.e.
a portion of the cylinder block surrounding the cylinder bores
other than the between-bores portions) is received from the
combustion in the combustion chambers.
[0006] Thus, when the between-bores portions and the
bore-surrounding portion are commonly cooled by the cooling water,
the temperatures of the between-bores portions are higher than the
temperature of the bore-surrounding portion. As a result,
temperatures of the between-bores portions and a temperature of the
bore-surrounding portion are not maintained in the temperature
range capable of decreasing the friction resistances.
SUMMARY
[0007] The invention has been made for solving the above-mentioned
problems. An object of the invention is to provide a cooling
apparatus of the internal combustion engine for maintaining the
temperatures of the between-bores portions and the bore-surrounding
portion in the temperature range capable of decreasing the friction
resistances.
[0008] A cooling apparatus of an internal combustion engine (10)
according to the invention cools a cylinder block (30) of the
internal combustion engine and a cylinder head (20) mounted on the
cylinder block by cooling medium. Cylinder bores (31 to 33) are
formed in the cylinder block.
[0009] The cooling apparatus according to the invention comprises a
first passage (52 and 53), a second passage (50) and a cooling
medium supplying mechanism (60 to 62, 71 to 77, and 90; and 63 to
66, 72 to 74, 78, and 79).
[0010] The first passage is formed in the cylinder block, through
which the cooling medium flows for cooling between-bores portions
(30L and 30R) each corresponding to a portion of the cylinder block
surrounding and between adjacent cylinder bores formed in the
cylinder block.
[0011] The second passage is formed in the cylinder block, through
which the cooling medium flows for cooling a bore-surrounding
portion (30P) corresponding to a portion of the cylinder block
surrounding the cylinder bores other than the between-bores
portions.
[0012] The cooling medium supplying mechanism may supply the
cooling medium to the first and second passages such that ability
of the cooling medium for cooling the between-bore portions, is
different from the ability of the cooling medium for cooling the
bore-surrounding portion.
[0013] The cooling apparatus according to the invention may supply
the cooling medium to the first passage, through which the cooling
medium flows to cool the between-bores portions, and the second
passage, through which the cooling medium flows to cool the
bore-surrounding portion such that ability of the cooling medium of
cooling the between-bores portions, is different from ability of
the cooling medium of cooling the bore-surrounding portion by the
cooling medium supplying mechanism. Therefore, the cooling
apparatus according to the invention may supply the cooling medium
having the relatively large ability of cooling the between-bores
portions and the cooling medium having the relatively large ability
of cooling the bore-surrounding portion. Thus, the temperatures of
the between-bores portions and the bore surrounding portion may be
maintained in the temperature range capable of decreasing the
friction resistances.
[0014] The cm supplying mechanism may include a head passage (40)
formed in the cylinder head, through which the cooling medium flows
for cooling the cylinder head. In this case, the first passage may
be connected to the head passage.
[0015] It is desired to maintain the temperature of the cylinder
head at a low temperature for preventing knocking from being
generated in the engine. When the first passage is communicated
with the head passage, the temperatures of the between-bores
portions is likely to be maintained in the temperature range
capable of decreasing the friction resistances by supplying to the
head passage the cooling medium having the ability of cooling the
cylinder head to maintain the temperature of the cylinder head to a
temperature range capable of preventing the generation of the
knocking in the engine. Therefore, according to the invention, even
though the cooling apparatus has a simple configuration, the
temperatures of the between-bores portions may be maintained in the
temperature range capable of decreasing the friction
resistances.
[0016] The cm supplying mechanism may include a common passage (71)
communicated with the first and second passages and a flow rate
control valve (62) for controlling a flow rate of the cooling
medium supplied to the second passage via the common passage.
[0017] As the flow rate of the cooling medium supplied to the
second passage decreases, a degree of cooling the bore-surrounding
portion by the cooling medium decreases. On the other hand, as the
flow rate of the cooling medium supplied to the second passage
increases, a degree of cooling the between-bores portions by the
cooling medium increases. When the flow rate of the cooling medium
supplied to the second passage is decreased by the flow rate
control valve while the cooling medium is supplied to the first and
second passage via the common passage, the flow rate of the cooling
medium supplied to the first passage increases. Therefore, the
degree of cooling the bore-surrounding portion by the cooling
medium supplied to the second passage changes by changing the flow
rate of the cooling medium supplied to the second passage.
Similarly, the degree of cooling the between-bores portions by the
cooling medium supplied to the first passage changes by changing
the flow rate of the cooling medium supplied to the first
passage.
[0018] Therefore, the cooling medium having the ability of cooling
the between-bores portions to maintain the temperatures of the
between-bores portions in the temperature range capable of
decreasing the friction resistances, may be surely supplied to the
first passage, and the cooling medium having the ability of cooling
the bore-surrounding portion to maintain the temperatures of the
bore-surrounding portion in the temperature range capable of
decreasing the friction resistances, may be surely supplied to the
second passage by adjusting the flow rate of the cooling medium
supplied to the second passage by the flow rate control valve.
Thus, the temperatures of the between-bores portions and the
bore-surrounding portion may be maintained surely in the
temperature range of decreasing the friction resistances.
[0019] The cm supplying mechanism may include a first cooling
device (64) for cooling the cooling medium supplied to the first
passage and a second cooling device (66) for cooling the cooling
medium supplied to the second passage. In this case, ability of the
first cooling device of cooling the cooling medium may be larger
than the ability of the second cooling device of cooling the
cooling medium.
[0020] According to the invention, the first cooling device for
cooling the cooling medium supplied to the first passage and the
second cooling device for cooling the cooling medium supplied to
the second passage, are provided separately. Therefore, the cooling
medium having the ability of cooling the between-bores portions to
maintain the temperatures of the between-bores portions in the
temperature range capable of decreasing the friction resistances,
may be supplied to the first passage by setting the ability of the
first cooling device of cooling the cooling medium such that the
cooling medium having the temperature capable of maintaining the
temperatures of the between-bores portions in the temperature range
of decreasing the friction resistances, is supplied to the first
passage. On the other hand, the cooling medium having the ability
of cooling the bore-surrounding portion to maintain the temperature
of the bore-surrounding portions in the temperature range capable
of decreasing the friction resistances, is supplied to the second
passage by setting the ability of the second cooling device of
cooling the cooling medium such that the cooling medium having the
temperature capable of maintaining the temperature of the
bore-surrounding portion in the temperature range of decreasing the
friction resistances, is supplied to the second passage. Thus, the
temperatures of the between-bores portions and the bore-surrounding
portion may be maintained surely in the temperature range of
decreasing the friction resistances.
[0021] In the above description, for facilitating understanding of
the present invention, elements of the present invention
corresponding to elements of an embodiment described later are
denoted by reference symbols used in the description of the
embodiment accompanied with parentheses. However, the elements of
the present invention are not limited to the elements of the
embodiment defined by the reference symbols. The other objects,
features, and accompanied advantages of the present invention can
be easily understood from the description of the embodiment of the
present invention along with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1A is a view for showing a cooling apparatus according
to an embodiment of the invention and an internal combustion
engine, to which the cooling apparatus is applied.
[0023] FIG. 1B is a view for showing a cylinder head shown in FIG.
1A.
[0024] FIG. 1C is a view for showing a cylinder block shown in FIG.
1A.
[0025] FIG. 2A is a cross sectional view for showing the cylinder
head along a plane P21 shown in FIG. 1B in a direction of an arrow
A21.
[0026] FIG. 2B is a cross sectional view for showing the cylinder
head along a plane Psp shown in FIG. 2A in a direction of an arrow
A22.
[0027] FIG. 2C is a cross sectional view for showing the cylinder
head along a plane P23 shown in FIG. 2A in a direction of an arrow
A23.
[0028] FIG. 2D is a cross sectional view for showing the cylinder
head along a plane P24 shown in FIG. 2A in a direction of an arrow
A24.
[0029] FIG. 3A is a cross sectional view for showing the cylinder
head along a plane P31 shown in FIG. 2A in a direction of an arrow
A31.
[0030] FIG. 3B is a cross sectional view for showing the cylinder
head along a plane P32 shown in FIG. 2A in a direction of an arrow
A32.
[0031] FIG. 3C is a cross sectional view for showing the cylinder
head along a plane P33 shown in FIG. 2A in a direction of an arrow
A33.
[0032] FIG. 4A is a cross sectional view for showing the cylinder
block along a plane P41 shown in FIG. 1C in a direction of an arrow
A41.
[0033] FIG. 4B is a cross sectional view for showing the cylinder
block along a plane Pb shown in FIG. 4A in a direction of an arrow
A42.
[0034] FIG. 4C is a cross sectional view for showing the cylinder
block along a plane P43 shown in FIG. 4A in a direction of an arrow
A43.
[0035] FIG. 5 is a plane view for showing the cylinder block in a
direction of the arrow A41 shown in FIG. 1C.
[0036] FIG. 6A is a cross sectional view for showing the cylinder
block along a plane P61 shown in FIG. 5 in a direction of an arrow
A61.
[0037] FIG. 6B is a cross sectional view for showing the cylinder
block along a plane P62 shown in FIG. 5 in a direction of an arrow
A62.
[0038] FIG. 6C is a cross sectional view for showing the cylinder
block along a plane P63 shown in FIG. 5 in a direction of an arrow
A63.
[0039] FIG. 7 is a view for showing a cooling water circulation
route of the cooling apparatus according to the embodiment.
[0040] FIG. 8 is a view similar to FIG. 7 for describing an
operation of the cooling apparatus shown in FIG. 7.
[0041] FIG. 9 is a view for showing the cooling water circulation
route of the cooling apparatus according to a modified example of
the embodiment.
[0042] FIG. 10A is a view for showing a part of the cooling water
circulation route, which the cooling apparatuses according to the
embodiment and the modified example may employ.
[0043] FIG. 10B is a view for showing a part of another cooling
water circulation route, which the cooling apparatuses according to
the embodiment and the modified example may employ.
[0044] FIG. 11A is a view for showing a part of further another
cooling water circulation route, which the cooling apparatuses
according to the embodiment and the modified example may
employ.
[0045] FIG. 11B is a view for showing a part of further another
cooling water circulation route, which the cooling apparatuses
according to the embodiment and the modified example may
employ.
[0046] FIG. 12A is a view for showing a part of further another
cooling water circulation route, which the cooling apparatuses
according to the embodiment and the modified example may
employ.
[0047] FIG. 12B is a view for showing a part of further another
cooling water circulation route, which the cooling apparatuses
according to the embodiment and the modified example may
employ.
[0048] FIG. 13A is a view for showing a part of further another
cooling water circulation route, which the cooling apparatuses
according to the embodiment and the modified example may
employ.
[0049] FIG. 13B is a view for showing a part of further another
cooling water circulation route, which the cooling apparatuses
according to the embodiment and the modified example may
employ.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] A cooling apparatus of an internal combustion engine
according to an embodiment of the invention, will be described with
reference to the drawings. As shown in FIG. 1A, an internal
combustion engine 10, to which the cooling apparatus according to
the embodiment, includes a cylinder head 20 and a cylinder block
30. The cylinder head 20 is mounted on the cylinder block 30 and
secured to the cylinder block 30 by securing devices such as
bolts.
[0051] The cylinder head 20 has actually a complicated shape. In
this embodiment, for simplifying the description, the cylinder head
20 has a rectangular parallelepiped shape as shown in FIG. 1A and
FIG. 1B. Similarly, the cylinder block 30 has actually a
complicated shape. In this embodiment, for simplifying the
description, the cylinder block 30 has a rectangular parallelepiped
shape as shown in FIG. 1A and FIG. 1C.
[0052] In this description, a block contact surface 20B of the
cylinder head 20 is a wall surface of the cylinder head 20
contacting the cylinder block 30 when the cylinder head 20 is
mounted on the cylinder block 30. A head contact surface 30H of the
cylinder block 30 is a wall surface of the cylinder block 30
contacting the cylinder head 20 when the cylinder head 20 is
mounted on the cylinder block 30.
[0053] As shown in FIG. 2A to FIG. 2D, three head spaces 21 to 23
are provided on the block contact surface 20B of the cylinder head
20. Each of the head spaces 21 to 23 has a generally-conical shape.
The head spaces 21 to 23 are provided such that center axes C21 to
C23 are on a same plane.
[0054] Hereinafter, one of the head spaces 21 and 23 provided at an
outer side (i.e., the head space 21 provided at a left side of FIG.
2A) will be referred to as "the left head space 21". The remaining
head space 23 provided at an inner side will be referred to as "the
right head space 23". The head space 22 provided between the left
and right head spaces 21 and 23, will be referred to as "the center
head space 22".
[0055] One head water passage 40 and six communication water
passage 41 to 46 are formed in the cylinder head 20. Each of the
head water passage 40 and the communication water passages 41 to 46
is a water passage, through which cooling medium such as cooling
water flows.
[0056] The head water passage 40 includes an inlet 40in and an
outlet 40out. The cooling water flows into the head water passage
40 via the inlet 40in. The cooling water flows out from the head
water passage 40 via the outlet 40out. The head water passage 40 is
mainly provided in a portion of the cylinder head 20 surrounding
the head spaces 21 to 23.
[0057] As shown in FIG. 2A to FIG. 2D, and FIG. 3A to FIG. 3C, each
of the communication water passages 41 to 46 has a circular cross
section. Each of the communication water passages 41 to 46 are
provided such that each of the communication water passages 41 to
46 extends from the head water passage 40 to the block contact
surface 20B of the cylinder head 20 in a direction parallel with
the center axes C21 to C23 of the head spaces 21 to 23.
[0058] Each of the communication water passages 41 and 42 is
provided such that a center axis of each of the communication water
passages 41 and 42 is on a plane P31 perpendicular to a plane Psp
including the center axes C21 to C23 of the head spaces 21 to 23.
Each of the communication water passages 43 and 44 is provided such
that a center axis of each of the communication water passages 43
and 44 is on a plane P32 perpendicular to the plane Psp. Each of
the communication water passages 45 and 46 is provided such that a
center axis of each of the communication water passages 45 and 46
is on a plane P33 perpendicular to the plane Psp.
[0059] Each of the communication water passages 41, 43 and 45 is
provided such that the center axis of each of the communication
water passages 41, 43 and 45 is on a plane P23 parallel with the
plane Psp and away from the plane Psp at one side (upper side of
FIG. 2A) by a predetermined distance D. Each of the communication
water passages 42, 44 and 46 is provided such that the center axis
of each of the communication water passages 42, 44 and 46 is on a
plane P24 parallel with the plane Psp and away from the plane Psp
at the other side (lower side of FIG. 2A) by the predetermined
distance D.
[0060] As shown in FIG. 4A to FIG. 4C, three cylinder bores 31 to
33 are provided in the cylinder block 30. Each of the cylinder
bores 31 to 33 has a cylindrical space. Each of the cylinder bores
31 to 33 is provided such that center axes C31 to C33 of the
cylinder bores 31 to 33 are on the same plane Pb. Hereinafter, the
plane Pb will be referred to as "the bore axis plane Pb".
[0061] Hereinafter, one of the cylinder bores 31 and 33 provided at
an outer side (i.e., the left cylinder bore 31 provided at a left
side of FIG. 4A) will be referred to as "the left cylinder bore
31". The remaining cylinder bore 33 provided at an inner side
(i.e., the right cylinder bore 33 provided at a right side of FIG.
4A) will be referred to as "the right cylinder bore 33". The
cylinder bore 32 provided between the left and right cylinder bores
31 and 33, will be referred to as "the center cylinder bore
32".
[0062] The left cylinder bore 31 is provided such that a center
axis C31 of the left cylinder bore 31 corresponds to the center
axis C21 of the left head space 21 in the state that the cylinder
head 20 is mounted on the cylinder block 30. The center cylinder
bore 32 is provided such that a center axis C32 of the center
cylinder bore 32 corresponds to the center axis C22 of the center
head space 22 in the state that the cylinder head 20 is mounted on
the cylinder block 30. The right cylinder bore 33 is provided such
that a center axis C33 of the right cylinder bore 33 corresponds to
the center axis C23 of the right head space 23 in the state that
the cylinder head 20 is mounted on the cylinder block 30.
[0063] One bore-surrounding water passage 50, one bore-side water
passage 51, and two between-bores water passage 52 and 53 are
provided in the cylinder block 30. Each of the bore-surrounding
water passage 50, the bore-side water passage 51, and the
between-bores water passage 52 and 53 is a water passage, which
through the cooling medium such as the cooling water flows.
[0064] The bore-surrounding water passage 50 includes an inlet 50in
and an outlet 50out. The cooling water flows into the
bore-surrounding water passage 50 via the inlet 50in. The cooling
water flows out from the bore-surrounding water passage 50 via the
outlet 50out. As shown in FIG. 4A, the bore-surrounding water
passage 50 is provided in a bore-surrounding portion 30P which is a
portion of the cylinder block 30 surrounding the bores 31 to 33
other than a bore-side portion 30S, a left between-bores portion
30L, and a right between-bores portion 30R of the cylinder block
30.
[0065] The bore-side portion 30S is a portion of the cylinder block
30 between the left cylinder bore 31 and a left wall surface 30W of
the cylinder block 30. The left between-bores portion 30L is a
portion of the cylinder block 30 between the left and center
cylinder bores 31 and 32. The right between-bores portion 30R is a
portion of the cylinder block 30 between the center and right
cylinder bores 32 and 33.
[0066] The bore-side water passage 51 is provided in the bore-side
portion 30S. As shown in FIG. 5, the bore-side water passage 51
includes an inlet 51in having a circular section and an outlet
51out having a circular section. The cooling water flows into the
bore-side water passage 51 via the inlet 51in. The cooling water
flows out from the bore-side water passage 51 via the outlet 51out.
As shown in FIG. 6A, the inlet 51in and the outlet 51out of the
bore-side water passage 51 open at the head contact surface 30H of
the cylinder block 30.
[0067] The between-bores water passage 52 is provided in the left
between-bores portion 30L. Hereinafter, the between-bores water
passage 52 will be referred to as "the left between-bores water
passage 52". As shown in FIG. 5, the left between-bores water
passage 52 includes an inlet 52in having a circular section and an
outlet 52out having a circular section. The cooling water flows
into the left between-bores water passage 52 via the inlet 52in.
The cooling water flows out from the left between-bores water
passage 52 via the outlet 52out. As shown in FIG. 6B, the inlet
52in and the outlet 52out of the left between-bores water passage
52 open at the head contact surface 30H of the cylinder block
30.
[0068] The between-bores water passage 53 is provided in the right
between-bores portion 30R. Hereinafter, the between-bores water
passage 53 will be referred to as "the right between-bores water
passage 53". As shown in FIG. 5, the right between-bores water
passage 53 includes an inlet 53in having a circular section and an
outlet 53out having a circular section. The cooling water flows
into the right between-bores water passage 53 via the inlet 53in.
The cooling water flows out from the right between-bores water
passage 53 via the outlet 53out. As shown in FIG. 6C, the inlet
53in and the outlet 53out of the right between-bores water passage
53 open at the head contact surface 30H of the cylinder block
30.
[0069] As shown in FIG. 5, the inlet 51in and the outlet 51out of
the bore-side water passage 51 are provided such that centers of
the inlet 51in and the outlet 51out are on a plane P61
perpendicular to the bore axis plane Pb including the center axes
C31 to C33 of the left cylinder bore 31 to 33. The inlet 52in and
the outlet 52out of the left between-bores water passage 52 are
provided such that centers of the inlet 52in and the outlet 52out
are on a plane P62 perpendicular to the bore axis plane Pb. The
inlet 53in and the outlet 53out of the right between-bores water
passage 53 are provided such that centers of the inlet 53in and the
outlet 53out are on a plane P63 perpendicular to the bore axis
plane Pb.
[0070] The inlet 51in of the bore-side water passage 51, the inlet
52in of the left between-bores water passage 52, and the inlet 53in
of the right between-bores water passage 53 are provided such that
the centers of the inlets 51in, 52in, and 53in are on a plane 64P
parallel with the bore axis plane Pb and away from the bore axis
plane Pb toward one side (upper side of FIG. 5) by the
predetermined distance D.
[0071] The outlet 51out of the bore-side water passage 51, the
outlet 52out of the left between-bores water passage 52, and the
outlet 53out of the right between-bores water passage 53 are
provided such that the centers of the outlets 51out, 52out, and
53out are on a plane 65P parallel with the bore axis plane Pb and
away from the bore axis plane Pb toward the other side (lower side
of FIG. 5) by the predetermined distance D.
[0072] The inlet 51in of the bore-side water passage 51 is provided
at a position that the inlet 51in communicates with the head water
passage 40 via the communication water passage 41 of the cylinder
head 20 in the state that the cylinder head 20 is mounted on the
cylinder block 30. The outlet 51out of the bore-side water passage
51 is provided at a position that the outlet 51out communicates
with the head water passage 40 via the communication water passage
42 of the cylinder head 20 in the state that the cylinder head 20
is mounted on the cylinder block 30.
[0073] The inlet 52in of the left between-bores water passage 52 is
provided at a position that the inlet 52in communicates with the
head water passage 40 via the communication water passage 43 of the
cylinder head 20 in the state that the cylinder head 20 is mounted
on the cylinder block 30. The outlet 52out of the left
between-bores water passage 52 is provided at a position that the
outlet 52out communicates with the head water passage 40 via the
communication water passage 44 of the cylinder head 20 in the state
that the cylinder head 20 is mounted on the cylinder block 30.
[0074] The inlet 53in of the right between-bores water passage 53
is provided at a position that the inlet 53in communicates with the
head water passage 40 via the communication water passage 45 of the
cylinder head 20 in the state that the cylinder head 20 is mounted
on the cylinder block 30. The outlet 53out of the right
between-bores water passage 53 is provided at a position that the
outlet 53out communicates with the head water passage 40 via the
communication water passage 46 of the cylinder head 20 in the state
that the cylinder head 20 is mounted on the cylinder block 30.
[0075] As shown in FIG. 6A, the bore-side water passage 51 extends
along the plane P61 (see FIG. 5) from the inlet 51in to the bore
axis plane Pb obliquely to the bore axis plane Pb. The bore-side
water passage 51 changes its extension direction at the bore axis
plane Pb and extends along the plane P61 from the bore axis plane
Pb to the outlet 51out obliquely to the bore axis plane Pb.
[0076] As shown in FIG. 6B, the left between-bores water passage 52
extends along the plane P62 (see FIG. 5) from the inlet 52in to the
bore axis plane Pb obliquely to the bore axis plane Pb. The left
between-bores water passage 52 changes its extension direction at
the bore axis plane Pb and extends along the plane P62 from the
bore axis plane Pb to the outlet 52out obliquely to the bore axis
plane Pb.
[0077] As shown in FIG. 6C, the right between-bores water passage
53 extends along the plane P63 (see FIG. 5) from the inlet 53in to
the bore axis plane Pb obliquely to the bore axis plane Pb. The
right between-bores water passage 53 changes its extension
direction at the bore axis plane Pb and extends along the plane P63
from the bore axis plane Pb to the outlet 53out obliquely to the
bore axis plane Pb.
[0078] As shown in FIG. 7, the cooling apparatus according to the
embodiment includes a pump 60, a radiator 61, and a flow rate
control valve 62.
[0079] The pump 60 is activated by rotation of a crank shaft (not
shown) of the engine 10. One end 71A of a common water supply pipe
71 is connected to a discharging opening 60out of the pump 60. The
common water supply pipe 71 defines a cooling water passage,
through which the cooling water flows.
[0080] The other end 71B of the common water supply pipe 71 is
connected to one end 72A of a head water supply pipe 72 and one end
73A of a block water supply pipe 73. Each of the head and block
water supply pipes 72 and 73 defines the cooling water passage. The
other end 72B of the head water supply pipe 72 is connected to the
inlet 40in of the head water passage 40. The other end 73B of the
block water supply pipe 73 is connected to the inlet 50in of the
bore-surrounding water passage 50.
[0081] The outlet 40out of the head water passage 40 is connected
to one end 74A of a head discharging pipe 74 defining the cooling
water passage. A temperature sensor 91 is provided on the head
discharging pipe 74. The temperature sensor 91 is electrically
connected to an electronic control unit 90. The temperature sensor
91 detects a temperature THWhd of the cooling water flowing through
the head discharging pipe 74 and outputs a signal representing the
temperature THWhd to the electronic control unit 90. The electronic
control unit 90 acquires the temperature THWhd on the basis of the
signal. Hereinafter, the electronic control unit 90 will be
referred to as "the ECU 90". The temperature THWhd will be referred
to as "the head water temperature THWhd".
[0082] The outlet 50out of the bore-surrounding water passage 50 is
connected to one end 75A of a block discharging pipe 75 defining
the cooling water passage. A temperature sensor 92 is provided on
the block discharging pipe 75. The temperature sensor 92 is
electrically connected to the ECU 90. The temperature sensor 92
detects a temperature THWbr of the cooling water flowing through
the block discharging pipe 75 and outputs a signal representing the
temperature THWbr to the ECU 90. The ECU 90 acquires the
temperature THWbr on the basis of the signal. Hereinafter, the
temperature THWbr will be referred to as "the block water
temperature THWbr".
[0083] The other end 74B of the head discharging pipe 74 and the
other end 75B of the block discharging pipe 75 are connected to one
end 76A of a common discharging pipe 76 defining the cooling water
passage. The other end 76B of the common discharging pipe 76 is
connected to an inlet 61in of the radiator 61. An outlet 61out of
the radiator 61 is connected to one end 77A of a common return pipe
77 defining the cooling water passage. The other end 77B of the
common return pipe 77 is connected to a suctioning opening 60in of
the pump 60. The radiator 61 is a cooling device for cooling the
cooling water flowing through the radiator 61.
[0084] The flow rate control valve 62 is provided in the block
water supply pipe 73. The flow rate control valve 62 is
electrically connected to the ECU 90. An opening degree of the flow
rate control valve 62 is controlled by the ECU 90. When the opening
degree of the flow rate control valve 62 is controlled to zero,
that is, when the flow rate control valve 62 is closed, the cooling
water passage defined by the block water supply pipe 73 is shut off
by the flow rate control valve 62. In this case, the flow rate of
the cooling water flowing through the flow rate control valve 62 is
zero.
[0085] When the opening degree of the flow rate control valve 62
increases while a discharging flow rate of the cooling water from
the pump 60 is constant, the flow rate of the cooling water flowing
through the flow rate control valve 62 increases. When the opening
degree of the flow rate control valve 62 is controlled to a maximum
opening degree, that is, when the radiator 61 opens fully, the flow
rate of the cooling water flowing through the flow rate control
valve 62 is controlled to a maximum flow rate associated with the
flow rate of the cooling water discharged from the pump 60.
[0086] The ECU 90 is an electronic control circuit including a
microcomputer as a main component including a CPU, a ROM, a RAM, an
interface, etc. The CPU realizes various functions by executing
instructions or routines stored in a memory (i.e., the ROM).
[0087] An acceleration pedal operation amount sensor 93 and a crank
angle sensor 94 are electrically connected to the ECU 90.
[0088] The acceleration pedal operation amount sensor 93 detects an
operation amount AP of an acceleration pedal (not shown) and
outputs a signal representing the operation amount AP. The ECU 90
acquires an engine load KL requested for the engine 10 on the basis
of the signal.
[0089] The crank angle sensor 94 outputs a pulse signal to the ECU
90 every the crank shaft (not shown) rotates by a predetermined
angle. The ECU 90 acquires a rotation speed of the engine 10 as an
engine speed NE on the basis of the pulse signal.
[0090] <Operation of Cooling Apparatus>
[0091] Below, an operation of the cooling apparatus according to
the embodiment will be described. The pump 60 is activated while
the engine 10 operates. Thereby, as shown in FIG. 8, the cooling
water is discharged to the common water supply pipe 71 via the
discharging opening 60out of the pump 60.
[0092] When the opening degree of the flow rate control valve 62 is
larger than zero, a part of the cooling water flowing out from the
common water supply pipe 71, flows into the head water supply pipe
72, and the remaining of the cooling water flowing out from the
common water supply pipe 71, flows into the block water supply pipe
73. As the opening degree of the flow rate control valve 62
increases, the flow rate of the cooling water flowing into the
block water supply pipe 73, increases. As a result, the flow rate
of the cooling water flowing into the head water supply pipe 72,
decreases.
[0093] On the other hand, when the opening degree of the flow rate
control valve 62 is zero, no cooling water flows into the block
water supply pipe 73. Therefore, all of the cooling water flowing
out from the common water supply pipe 71, flows into the head water
supply pipe 72.
[0094] The ECU 90 sets a target of the opening degree of the flow
rate control valve 62 on the basis of the engine load KL, the
engine speed NE, the head water temperature THWhd, the block water
temperature THWbr, etc. In particular, the ECU 90 sets the target
of the opening degree of the flow rate control valve 62 such that
the cooling water having the flow rate capable of accomplishing a
request for preventing knocking from being generated in cylinders
of the engine 10, flows into the head water passage 40, and the
cooling water having the flow rate capable of accomplishing a
request for decreasing friction, flows into the bore-surrounding
water passage 50. The ECU 90 controls the opening degree of the
flow rate control valve 62 to the target of the opening degree of
the flow rate control valve 62. Hereinafter, the request for
preventing the knocking from being generated in the cylinders of
the engine 10, will be referred to "the knocking prevention
request". The request for decreasing the friction will be referred
to as "the friction decreasing request".
[0095] The cooling water flowing out from the head water supply
pipe 72, flows into the head water passage 40 via the inlet 40in. A
part of the cooling water flowing into the head water passage 40,
flows into the bore-side water passage 51, the left between-bores
water passage 52, and the right between-bores water passage 53
through the communication water passages 41, 43, and 45,
respectively. Therefore, the communication water passages 41, 43,
and 45 are water passages for connecting the bore-side water
passage 51, the left between-bores water passage 52, and the right
between-bores water passage 53 to the head water passage 40,
respectively.
[0096] The cooling water flowing out from the bore-side water
passage 51, the left between-bores water passage 52, and the right
between-bores water passage 53, returns to the head water passage
40 through the communication water passages 42, 44, and 46,
respectively. Therefore, the communication water passages 42, 44,
and 46 are water passages for connecting the bore-side water
passage 51, the left between-bores water passage 52, and the right
between-bores water passage 53 to the head water passage 40,
respectively.
[0097] The bore-side portion 30S is cooled by the cooling water
flowing through the bore-side water passage 51. The left
between-bores portion 30L is cooled by the cooling water flowing
through the left between-bores water passage 52. The right
between-bores portion 30R is cooled by the cooling water flowing
through the right between-bores water passage 53. Therefore, the
bore-side water passage 51 is a water passage provided in the
cylinder block 30, through which the cooling water for cooling the
bore-side portion 30S flows. The left between-bores water passage
52 is a water passage provided in the cylinder block 30, through
which the cooling water for cooling the left between-bores portion
30L flows. The right between-bores water passage 53 is a water
passage provided in the cylinder block 30, through which the
cooling water for cooling the right between-bores portion 30R
flows.
[0098] The cooling water returned to the head water passage 40, is
discharged to the head discharging pipe 74 via the outlet
40out.
[0099] The remaining of the cooling water flowing into the head
water passage 40, flows through the head water passage 40 and is
discharged to the head discharging pipe 74 via the outlet 40out.
The cylinder head 20 is cooled by the cooling water flowing through
the head water passage 40. Therefore, the head water passage 40 is
a water passage provided in the cylinder head 20, through which the
cooling water for cooling the cylinder head 20 flows.
[0100] On the other hand, the cooling water flowing out from the
block water supply pipe 73, flows into the bore-surrounding water
passage 50 via the inlet 50in. The cooling water flowing into the
bore-surrounding water passage 50, flows through the
bore-surrounding water passage 50 and is discharged to the block
discharging pipe 75 via the outlet 50out. The bore-surrounding
portion 30P is cooled by the cooling water flowing through the
bore-surrounding water passage 50. Therefore, the bore-surrounding
water passage 50 is a water passage provided in the cylinder block
30, through which the cooling water for cooling the
bore-surrounding portion 30P flows.
[0101] The flow rate of the cooling water flowing into the
bore-surrounding water passage 50, is controlled by the flow rate
control valve 62. Therefore, the flow rate control valve 62 is a
device for controlling the flow rate of the cooling water supplied
to the bore-surrounding water passage 50 through the common water
supply pipe 71, that is, controlling a degree of cooling the
bore-surrounding portion 30P by the cooling water supplied to the
bore-surrounding water passage 50.
[0102] The cooling water flowing out from the head and block
discharging pipes 74 and 75, flows into the common discharging pipe
76. The cooling water flowing out from the common discharging pipe
76, flows into the radiator 61. The cooling water is cooled by the
radiator 61 while the cooling water flows through the radiator 61.
The cooling water flowing out from the radiator 61, flows into the
common return pipe 77. The cooling water flowing out from the
common return pipe 77, is suctioned into the pump 60 via the
suctioning opening 60in.
[0103] According to the embodiment, the flow rate of the cooling
water flowing into the left between-bores water passage 52 and the
right between-bores water passage 53 through the head water passage
40 and the flow rate of the cooling water flowing into the
bore-surrounding water passage 50 may be controlled independently
by controlling and adjusting the opening degree of the flow rate
control valve 62.
[0104] Therefore, the temperatures of the left between-bores
portion 30L, the right between-bores portion 30R, and the
bore-surrounding portion 30P may be maintained in a friction
decreasing temperature range described below by controlling the
opening degree of the flow rate control valve 62 such that the flow
rate of the cooling water supplied to the head water passage 40 is
controlled to a flow rate capable of maintaining the temperature of
the cylinder head 20 in a knocking prevention temperature range
described below and maintaining the temperatures of the left
between-bores portion 30L and the right between-bores portion 30R
in the friction decreasing temperature range, and the flow rate of
the cooling water supplied to the bore-surrounding water passage 50
is controlled to a flow rate capable of maintaining the temperature
of the bore-surrounding portion 30P in the friction decreasing
temperature range. The friction decreasing temperature range is a
temperature range capable of accomplishing the friction decreasing
request. The knocking prevention temperature range is a temperature
range capable of accomplishing the knocking prevention request.
[0105] It should be noted that the present invention is not limited
to the aforementioned embodiment, and various modifications can be
employed within the scope of the present invention.
Modified Example
[0106] As shown in FIG. 9, the cooling apparatus according to a
modified example of the embodiment may be configured such that a
cooling water circulation route for supplying the cooling water to
the head water passage 40 and a cooling water circulation route for
supplying the cooling water to the bore-surrounding water passage
50 are provided independently.
[0107] The cooling apparatus according to the modified example
includes a first pump 63, a first radiator 64, a second pump 65,
and a second radiator 66.
[0108] The first and second pumps 63 and 65 are activated by the
rotation of the crank shaft (not shown) of the engine 10. The first
and second pumps 63 and 65 are configured such that the discharging
flow rate of the first pump 63 is larger than the discharging flow
rate of the second pump 65 when a rotation speed of the crank shaft
is constant, the first and second pumps 63 and 65.
[0109] The first and second radiators 64 and 66 are configured such
that the degree of cooling the cooling water by the first radiator
64 is larger than the degree of the cooling the cooling water by
the second radiator 66 when the flow rate of the cooling water
flowing through the first radiator 64 is equal to the flow rate of
the cooling water flowing through the second radiator 66.
[0110] One end 72A of the head water supply pipe 72 is connected to
a discharging opening 63out of the first pump 63. The other end 72B
of the head water supply pipe 72 is connected to the inlet 40in of
the head water passage 40.
[0111] The outlet 40out of the head water passage 40 is connected
to one end 74A of the head discharging pipe 74. The other end 74B
of the head discharging pipe 74 is connected to an inlet 64in of
the first radiator 64. An outlet 64out of the first radiator 64 is
connected to one end 78A of a first return pipe 78 defining the
cooling water passage. The other end 78B of the first return pipe
78 is connected to a suctioning opening 63in of the first pump
63.
[0112] The configurations of the communication water passages 41 to
46, the bore-side water passage 51, and the left and right
between-bores water passages 52 and 53 are the same as the
configuration of the communication water passage 41 to 46, the
bore-side water passage 51, and the left and right between-bores
water passages 52 and 53 of the embodiment, respectively.
[0113] A discharging opening 65out of the second pump 65 is
connected to one end 73A of the block water supply pipe 73. The
other end 73B of the block water supply pipe 73 is connected to the
inlet 50in of the bore-surrounding water passage 50.
[0114] The outlet 50out of the bore-surrounding water passage 50 is
connected to one end 75A of the block discharging pipe 75. The
other end 75B of the block discharging pipe 75 is connected to an
inlet 66in of the second radiator 66. An outlet 66out of the second
radiator 66 is connected to one end 79A of the second return pipe
79 defining the cooling water passage. The other end 79B of the
second return pipe 79 is connected to a suctioning opening 65in of
the second pump 65.
[0115] According to the modified example, the degree of cooling the
left between-bores portion 30L and the right between-bores portion
30R by the cooling water flowing through the left between-bores
water passage 52 and the right between-bores water passage 53, is
larger than the degree of cooling the bore-surrounding portion 30P
by the cooling water flowing through the bore-surrounding water
passage 50. Thus, the temperatures of the left between-bores
portion 30L, the right between-bores portion 30R, and the
bore-surrounding portion 30P may be maintained in the friction
decreasing temperature range.
[0116] The cooling apparatuses according to the embodiment and the
modified example, may be configured as shown in FIG. 10A. In the
cooling apparatus shown in FIG. 10A, the inlet 50in of the
bore-surrounding water passage 50 is connected to the other end 73B
of the block water supply pipe 73 through a block connection water
passage 501 provided in the cylinder head 20.
[0117] In particular, the block connection water passage 501 is
provided such that one end of the block connection water passage
501 is open at a wall surface of the cylinder head 20 other than
the block contact surface 20B, and the other end of the block
connection water passage 501 is open at the block contact surface
20B. One end of the block connection water passage 501 is connected
to the other end 73B of the block water supply pipe 73, and the
other end of the block connection water passage 501 is connected to
the inlet 50in of the bore-surrounding water passage 50.
[0118] Further, the cooling apparatuses according to the embodiment
and the modified example, may be configured as shown in FIG. 10B.
In the configuration shown in FIG. 10B, the inlet 40in of the head
water passage 40 is connected to the other end 72B of the head
water supply pipe 72 through a head connection water passage 401
provided in the cylinder block 30.
[0119] In particular, the head connection water passage 401 is
provided such that one end of the head connection water passage 401
is open at a wall surface of the cylinder block 30 other than the
head contact surface 30H, and the other end of the head connection
water passage 401 is open at the head contact surface 30H. One end
of the head connection water passage 401 is connected to the other
end 72B of the head water supply pipe 72, and the other end of the
head connection water passage 401 is connected to the inlet 40in of
the head water passage 40.
[0120] Furthermore, the cooling apparatuses according to the
embodiment and the modified example, may be configured as shown in
FIG. 11A. In the configuration shown in FIG. 11A, the outlet 50out
of the bore-surrounding water passage 50 is connected to one end
75A of the block discharging pipe 75 through a block connection
water passage 502 provided in the cylinder head 20.
[0121] In particular, the block connection water passage 502 is
provided such that one end of the block connection water passage
502 is open at the block contact surface 20B of the cylinder head
20, and the other end of the block connection water passage 502 is
open at a wall surface of the cylinder head 20 other than the block
contact surface 20B. One end of the block connection water passage
502 is connected to the outlet 50out of the bore-surrounding water
passage 50, and the other end of the block connection water passage
502 is connected to one end 75A of the block discharging pipe
75.
[0122] Further, the cooling apparatuses according to the embodiment
and the modified example, may be configured as shown in FIG. 11B.
In the configuration shown in FIG. 11B, the outlet 40out of the
head water passage 40 is connected to one end 74A of the head
discharging pipe 74 through a head connection water passage 402
provided in the cylinder block 30.
[0123] In particular, the head connection water passage 402 is
provided such that one end of the head connection water passage 402
is open at the head contact surface 30H of the cylinder block 30,
and the other end of the head connection water passage 402 is open
at a wall surface of the cylinder block 30 other than the head
contact surface 30H. One end of the head connection water passage
402 is connected to the outlet 40out of the head water passage 40,
and the other end of the head connection water passage 402 is
connected to one end 74A of the head discharging pipe 74.
[0124] Furthermore, the cooling apparatus according to the
embodiment, may be configured as shown in FIG. 12A. In the
configuration shown in FIG. 12A, a common connection water passage
81 is provided in the cylinder head 20. The outlet 40out of the
head water passage 40 is connected to one end of the common
connection water passage 81. The outlet 50out of the
bore-surrounding water passage 50 is connected to one end of the
common connection water passage 81 through a block connection water
passage 503 provided in the cylinder head 20. The other end of the
common connection water passage 81 is connected to one end 76A of
the common discharging pipe 76.
[0125] Further, the cooling apparatus according to the embodiment,
may be configured as shown in FIG. 12B. In the configuration shown
in FIG. 12B, a common connection water passage 82 is provided in
the cylinder block 30. The outlet 50out of the bore-surrounding
water passage 50 is connected to one end of the common connection
water passage 82. The outlet 40out of the head water passage 40 is
connected to one end of the common connection water passage 82
through a head connection water passage 403 provided in the
cylinder block 30. The other end of the common connection water
passage 82 is connected to one end 76A of the common discharging
pipe 76.
[0126] Furthermore, the cooling apparatuses according to the
embodiment and the modified example, may be configured as shown in
FIG. 13A. In the configuration shown in FIG. 13A, introduction
water passages 471 to 474 are provided in the cylinder head 20. One
end of the introduction water passage 471 is connected to a
between-bores supply pipe 83 defining the cooling water passage.
The other end of the introduction water passage 471 is connected to
the communication water passage 41. One end of the introduction
water passage 472 is connected to the communication water passage
42. The other end of the introduction water passage 472 is
connected to the communication water passage 43. One end of the
introduction water passage 473 is connected to the communication
water passage 44. The other end of the introduction water passage
473 is connected to the communication water passage 45. One end of
the introduction water passage 474 is connected to the
communication water passage 46. The other end of the introduction
water passage 474 is connected to a between-bores discharging pipe
84 defining the cooling water passage.
[0127] The between-bores supply pipe 83 is connected to the head
water supply pipe 72, and the between-bores discharge pipe 84 is
connected to the head discharging pipe 74.
[0128] When the flow rate control valve 62 is provided in the block
water supply pipe 73, the between-bores supply pipe 83 may be
connected to the block water supply pipe 73 upstream of the flow
rate control valve 62. Further, the between-bores discharge pipe 84
may be connected to the block discharging pipe 75.
[0129] Further, the cooling water circulation route for supplying
the cooling water to the bore-side water passage 51, the left
between-bores water passage 52, and the right between-bores water
passage 53, may be provided such that the cooling water circulation
route is separated from the cooling water circulation route for
supplying the cooling water to the head water passage 40 and the
cooling water circulation route for supplying the cooling water to
the bore-surrounding water passage 50.
[0130] Furthermore, the cooling apparatuses according to the
embodiment and the modified example, may be configured as shown in
FIG. 13B. In the configuration shown in FIG. 13B, introduction
water passages 541 to 544 are provided in the cylinder block 30.
One end of the introduction water passage 541 is connected to a
between-bores supply pipe 85 defining the cooling water passage.
The other end of the introduction water passage 541 is connected to
the bore-side water passage 51. One end of the introduction water
passage 542 is connected to the bore-side water passage 51. The
other end of the introduction water passage 542 is connected to the
left between-bores water passage 52. One end of the introduction
water passage 543 is connected to the left between-bores water
passage 52. The other end of the introduction water passage 543 is
connected to the right between-bores water passage 53. One end of
the introduction water passage 544 is connected to the right
between-bores water passage 53. The other end of the introduction
water passage 544 is connected to a between-bores discharging pipe
86 defining the cooling water passage.
[0131] The between-bores supply pipe 85 is connected to the head
water supply pipe 72, and the between-bores discharging pipe 86 is
connected to the head discharging pipe 74.
[0132] When the flow rate control valve 62 is provided in the block
water supply pipe 73, the between-bores supply pipe 85 may be
connected to the block water supply pipe 73 upstream of the flow
rate control valve 62. Further, the between-bores discharging pipe
86 may be connected to the block discharging pipe 75.
[0133] Further, the cooling water circulation route for supplying
the cooling water to the bore-side water passage 51, the left
between-bores water passage 52, and the right between-bores water
passage 53, may be provided such that the cooling water circulation
route is separated from the cooling water circulation route for
supplying the cooling water to the head water passage 40 and the
cooling water circulation route for supplying the cooling water to
the bore-surrounding water passage 50.
[0134] Furthermore, the cooling apparatus according to the
embodiment, may include radiators provided in the head water supply
pipe 72 and the block water supply pipe 73, respectively in place
of the radiator 61. In this case, the radiator provided in the head
water supply pipe 72 is configured to decrease the temperature of
the cooling water to a temperature capable of maintaining the
temperature of the cylinder head 20 in the knocking prevention
temperature range and the temperatures of the left between-bores
portion 30L and the right between-bores portion 30R in the friction
decreasing temperature range. In addition, the radiator provided in
the block water supply pipe 73 is configured to decrease the
temperature of the cooling water to a temperature capable of
maintaining the temperature of the bore-surrounding portion 30P in
the friction decreasing temperature range. In this case, the flow
rate control valve 62 may be omitted.
[0135] Further, the cooling apparatus according to the embodiment,
may include pumps provided in the head water supply pipe 72 and the
block water supply pipe 73, respectively in place of the pump 60.
In this case, the pump provided in the head water supply pipe 72 is
configured to supply to the head water passage 40, the cooling
water having the flow rate capable of maintaining the temperature
of the cylinder head 20 in the knocking prevention temperature
range and the temperatures of the left between-bores portion 30L
and the right between-bores portion 30R in the friction decreasing
temperature range. In addition, the pump provided in the block
water supply pipe 73 is configured to supply to the
bore-surrounding water passage 50, the cooling water having the
flow rate capable of maintaining the temperature of the
bore-surrounding portion 30P in the friction decreasing temperature
range. In this case, the flow rate control valve 62 may be
omitted.
[0136] Furthermore, the pump 60 may be an electric pump activated
by electric power supplied from a battery and the like. When the
pump 60 is the electric pump, the flow rate of the cooling water
discharged from the pump 60 may be controlled, independently of the
engine speed NE.
[0137] When the pump 60 is the electric pump, the pump 60 is
electrically connected to the ECU 90. The ECU 90 sets a target of
the opening degree of the flow rate control valve 62 and a target
of the flow rate of the cooling water discharged from the pump 60
on the basis of the engine load KL, the engine speed NE, the head
water temperature THWhd, the block water temperature THWbr and the
like.
[0138] In particular, the ECU 90 sets the target of the opening
degree of the flow rate control valve 62 and the target of the flow
rate of the cooling water discharged from the pump 60 for supplying
to the head water passage 40, the cooling water having the flow
rate capable of maintaining the temperature of the cylinder head 20
in the knocking prevention temperature range and the temperatures
of the left between-bores portion 30L and the right between-bores
portion 30R in the friction decreasing temperature range, and
supplying to the bore-surrounding water passage 50, the cooling
water having the flow rate capable of maintaining the temperature
of the bore-surrounding portion 30P in the friction decreasing
temperature range. The ECU 90 controls the opening degree of the
flow rate control valve 62 and the activation of the pump 60 such
that the opening degree of the flow rate control valve 62
corresponds to the target thereof, and the flow rate of the cooling
water discharged from the pump 60 corresponds to the target
thereof.
* * * * *