U.S. patent application number 14/443099 was filed with the patent office on 2015-10-15 for pcv valve mounting structure.
This patent application is currently assigned to AISIN SEIKI KABUSHIKI KAISHA. The applicant listed for this patent is AISIN SEIKI KABUSHIKI KAISHA. Invention is credited to Naoki Kira, Atsushi Nishigaki.
Application Number | 20150292374 14/443099 |
Document ID | / |
Family ID | 50775969 |
Filed Date | 2015-10-15 |
United States Patent
Application |
20150292374 |
Kind Code |
A1 |
Kira; Naoki ; et
al. |
October 15, 2015 |
PCV VALVE MOUNTING STRUCTURE
Abstract
A PCV valve mounting structure which releases freezing of a PCV
valve promptly is provided. A PCV valve mounting structure is
provided with a resin cover forming an internal space portion
between the resin cover and a cylinder head of an internal
combustion engine, a valve mounting through hole formed at the
resin cover, a PCV valve including a valve case portion inserted
through the valve mounting through hole from outside the resin
cover, and a metal fixture threadedly engaged, from inside the
resin cover, with the valve case portion inserted through the valve
mounting through hole, at least part of the metal fixture being
exposed to the internal space portion.
Inventors: |
Kira; Naoki; (Nagoya-shi,
JP) ; Nishigaki; Atsushi; (Anjo-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN SEIKI KABUSHIKI KAISHA |
Aichi |
|
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi
JP
|
Family ID: |
50775969 |
Appl. No.: |
14/443099 |
Filed: |
November 11, 2013 |
PCT Filed: |
November 11, 2013 |
PCT NO: |
PCT/JP2013/080428 |
371 Date: |
May 15, 2015 |
Current U.S.
Class: |
123/574 |
Current CPC
Class: |
F02F 7/006 20130101;
F01M 2013/0027 20130101; F01M 13/0416 20130101; F01M 2013/0427
20130101; F01M 13/0011 20130101 |
International
Class: |
F01M 13/00 20060101
F01M013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 22, 2012 |
JP |
2012-256711 |
Claims
1. A PCV valve mounting structure, comprising: a resin cover
forming an internal space portion between the resin cover and a
cylinder head of an internal combustion engine; a valve mounting
through hole formed at the resin cover; a PCV valve including a
valve case portion inserted through the valve mounting through hole
from outside the resin cover; and a metal fixture threadedly
engaged, from inside the resin cover, with the valve case portion
inserted through the valve mounting through hole, at least part of
the metal fixture being exposed to the internal space portion.
2. The PCV valve mounting structure according to claim 1, wherein
the metal fixture is integrally provided with a cylindrical screw
portion which is insert molded in the resin cover and a heat
receiving portion extended from the cylindrical screw portion to
protrude into the internal space portion, and the valve case
portion is provided with a screw portion threadedly engaging with
the cylindrical screw portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a PCV valve mounting
structure including a cover forming an internal space portion
between the cover and a cylinder head of an internal combustion
engine, a valve mounting through hole formed at the cover and a PCV
valve (positive crankcase ventilation valve) including a valve case
portion inserted through the through hole from outside the
cover.
BACKGROUND ART
[0002] In recirculating a blow-by gas to an induction system, a PCV
valve is provided to adjust flow amount of the recirculation. The
blow-by gas corresponds to gas leaking out from a combustion
chamber to an inside of a crankcase in compression/combustion
processes of an internal combustion engine, for example. However,
because the PCV valve is provided at an outside of a cylinder head
and the PCV valve itself is exposed to outside air, moisture
included in the blow-by gas attaches to the PCV valve and freezes
especially in cold weather, and accordingly the PCV valve may be
prevented from operating normally.
[0003] Therefore, for example, the PCV valve is mounted on a cover
forming an internal space portion between the cover and the
cylinder head so that the frozen moisture can be defrosted with
heat generated at the internal combustion engine. In a case where
the cover is formed by metal having a high coefficient of thermal
conductivity, including, for example, aluminum alloy, the heat
generated at the internal combustion engine is efficiently
transmitted to the PCV valve via the cover made of the metal, and
accordingly the frozen moisture can be defrosted promptly. However,
in a case where the cover is formed by resin having a lower
coefficient of thermal conductivity compared to the metal,
efficiency of defrosting the frozen moisture is decreased.
[0004] In Patent document 1, a PCV valve mounting structure is
described which allows heat generated at an internal combustion
engine to be efficiently transmitted to the PCV valve mounted on a
resin cover. According to the mounting structure, a portion of the
PCV valve, the portion which is exposed to an internal space
portion between a cylinder head and the resin cover, is formed by
metal whose coefficient of thermal conductivity is high. It is
configured in such a manner that efficiency of heat transfer to the
PCV valve is enhanced and the frozen moisture is defrosted by
heating the metal portion with heat possessed by hot temperature
atmosphere of the internal space portion.
DOCUMENT OF KNOWN ART
Patent Document
[0005] Patent document 1: JP2009-150289A
OVERVIEW OF INVENTION
Problem to be Solved by the Invention
[0006] However, manufacturing cost of the PCV valve formed with the
metal portion exposed to the internal space portion between the
cylinder head and the resin cover is higher compared to a PCV valve
which does not include such metal portion and whole of which is
made of resin, for example. Because the PCV valve is designed
depending on a type of an internal combustion engine, also such
metal portion needs to be designed for each PCV valve. Accordingly,
in providing the PCV valve, inconvenience occurs in aspects of a
manufacturing efficiency and costs.
[0007] The present invention is made in view of the above-described
circumstances, and an object is to provide a PCV valve mounting
structure which efficiently transmits heat generated at an internal
combustion engine and releases freezing promptly even in a case
where the PCV valve is made of resin.
Measures for Solving the Problem
[0008] An aspect of a PCV valve mounting structure of the present
invention is that the PCV valve mounting structure includes a resin
cover forming an internal space portion between the resin cover and
a cylinder head of an internal combustion engine, a valve mounting
through hole formed at the resin cover, a PCV valve including a
valve case portion inserted through the valve mounting through hole
from outside the resin cover, and a metal fixture threadedly
engaged, from inside the resin cover, with the valve case portion
inserted through the valve mounting through hole, at least part of
the metal fixture being exposed to the internal space portion.
[0009] According to the PCV valve mounting structure including the
present configuration, at least part of the metal fixture
threadedly engaged with the valve case portion inserted through the
through hole is exposed to the internal space portion, and the
metal fixture can be heated with heat possessed by hot temperature
atmosphere of the internal space portion.
[0010] The foregoing metal fixture is applicable to any PCV valve
or to any valve case portion, and can be used as a common part.
Therefore, the PCV valve itself can be manufactured inexpensively
without using metal. In addition, the use of the common metal
fixture reduces a manufacturing unit price and makes an inventory
control easy, thereby even more increasing efficiency of the PCV
valve mounting structure.
[0011] An aspect of the PCV valve mounting structure of the present
invention is that the metal fixture is integrally provided with a
cylindrical screw portion which is insert molded in the resin cover
and a heat receiving portion extended from the cylindrical screw
portion to protrude into the internal space portion, and the valve
case portion is provided with a screw portion threadedly engaging
with the cylindrical screw portion.
[0012] According to the present configuration, by an operation of
threadedly engaging the screw portion, which is provided at the
valve case portion, with the cylindrical screw portion, which is
insert molded in the resin cover, the PCV valve can be mounted on
the resin cover conveniently. In addition, the heat receiving
portion protruding into the internal space portion is provided to
extend from the cylindrical screw portion, and thus a large area
for receiving the heat can be assured. Consequently, the heat
possessed by the hot temperature atmosphere of the internal space
portion is received at the large area for receiving the heat, and
accordingly the cylindrical screw portion can be heated. As a
result, according to the PCV valve mounting structure including the
present configuration, a freeze protection effect can be even more
enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 Cross-sectional view of an internal combustion engine
provided with a PCV valve
[0014] FIG. 2 Cross-sectional view illustrating a PCV valve
mounting structure
[0015] FIG. 3 Cross-sectional view illustrating a PCV valve
mounting structure of a second embodiment
MODE FOR CARRYING OUT INVENTION
[0016] Embodiments of the present invention will be described
hereunder on the basis of the drawings.
First Embodiment
[0017] FIG. 1 and FIG. 2 illustrate an engine (an internal
combustion engine) E provided with a PCV valve mounting structure
of the present embodiment. As illustrated in FIG. 1, the engine E
includes a cylinder head 1, a cylinder block 2, a crankcase 3 and
an oil pan 4 which are placed up and down to be arranged one above
another, and are connected to one another. A cylinder head cover 5
is provided at an upper portion of the cylinder head 1. The
cylinder head cover 5 is made of resin including nylon, for
example.
[0018] A crankshaft 6 is rotatably supported inside the crankcase 3
and pistons 7 are slidably fitted into plural cylinder bores formed
at the cylinder block 2. The pistons 7 and the crankshaft 6 are
connected to each other with connecting rods 8.
[0019] An air intake valve 9 and an exhaust valve 10 are provided
at the cylinder head 1 to be able to open and close. An intake cam
shaft 11 and an exhaust cam shaft 12, which are in postures that
are parallel to the crankshaft 6, are rotatably supported at upper
positions of the air intake valve 9 and the air exhaust valve
10.
[0020] An intake manifold 14 is connected to one lateral surface of
the cylinder head 1, an exhaust manifold 15 is connected to the
other lateral surface of the cylinder head 1. A spark plug 16
igniting air-fuel mixture of a combustion chamber 20 is provided at
an upper surface of the cylinder head 1.
[0021] An injector 17 supplying fuel to the combustion chamber 20
is provided at an air intake passage provided at the cylinder head
1 and the intake manifold 14 is connected to the air intake
passage. A surge tank 18 is provided at an upstream-side relative
to the intake manifold 14 and a throttle valve 19 is further
provided at an upstream-side relative to the surge tank 18.
[0022] Though not shown, an endless chain is wrapped along a
crankshaft sprocket provided at a shaft end of the crankshaft 6 and
cam sprockets provided at shaft ends of the respective intake cam
shaft 11 and exhaust cam shaft 12 so that the intake cam shaft 11
and the exhaust cam shaft 12 are rotated synchronously with
rotations of the crankshaft 6. The spark plug 16 and the injector
17 are provided to be controlled by a control apparatus (not shown)
including ECU, for example.
[0023] Due to the foregoing configuration, when the engine E is
operating, the intake cam shaft 11 and the exhaust cam shaft 12
rotate synchronously with the rotations of the crankshaft 6,
thereby opening an intake port of the air intake valve 9 due to a
compressive force from a cam portion of an outer circumference of
the intake cam shaft 11 at a predetermined timing. Similarly, an
exhaust port of the exhaust valve 10 is opened due to a compressive
force from a cam portion of an outer circumference of the exhaust
cam shaft 12 at a predetermined timing.
[0024] The control apparatus conducts control so that the injector
17 supplies the fuel to the combustion chamber 20 at the
predetermined timing at which the intake valve 9 opens and that the
spark plug 16 ignites the air-fuel mixture at a predetermined
timing at which the air-fuel mixture of the combustion chamber 20
is compressed.
[0025] Inside the cylinder head cover 5, feed oil pipes 21 are
arranged above the respective intake cam shaft 11 and exhaust cam
shaft 12 to be in postures parallel to the cam shafts 11 and 12.
Spray nozzles 21A spraying oil downwardly are provided at the feed
oil pipes 21.
[0026] Thus, when the engine E is operating, the oil supplied by a
hydraulic pump (not shown) to each of the feed oil pipes 21 is
sprayed from the spray nozzles 21A to the intake cam shaft 11 and
the exhaust cam shaft 12. Though not shown, a discharge port
discharging the oil is formed at the cylinder head 1 and an oil
passage returning the oil, which is discharged from the discharge
port, to the oil pan 4 is formed at the cylinder head 1.
[0027] When the engine E is operating, part of mixed gas introduced
to the combustion chamber 20 leaks out to a crank chamber 13 from a
gap between an outer circumference of the piston 7 and an inner
circumference of the corresponding cylinder. The unburnt mixed gas
that has leaked in this way is referred to as the blow-by gas. The
engine E is provided with a blow-by gas recirculation apparatus
recirculating the blow-by gas to the induction system of the engine
E and introducing the blow-by gas, together with new mixed gas, to
the combustion chamber 20 so that the introduced gas is burnt
thereat.
[0028] The blow-by gas recirculation apparatus supplies the blow-by
gas occurring in the crank chamber 13 to an oil separator 40
provided at an upper portion of the cylinder head cover 5 via a gas
extract path 22. The blow-by gas recirculation apparatus transports
the blow-by gas, from which oil mist is separated, to a gas space
portion S and stores the blow-by gas thereat. The blow-by gas
stored at the gas space portion S is sent to a gas return path 23
via a PCV valve 30, and is returned to the induction system
(specifically, the surge tank 18) of the engine E to be combusted
in the combustion chamber 20 together with the air-fuel
mixture.
[0029] As illustrated in FIG. 2, the oil separator 40 is fixed at
an upper surface of the cylinder head cover 5 while sandwiching a
gasket 24, and the oil separator 40 includes inside thereof a
cyclone-type separation unit 43 separating and removing the oil
mist included in the blow-by gas.
[0030] The oil separator 40 is integrally provided with an upper
part case portion 41 and a lower part case portion 42, and the gas
space portion (an internal space portion) S is formed at an inside
of the upper part case portion 41 and the separation unit 43 is
provided at an inside of the lower part case portion 42. A dividing
wall 44 is formed at an intermediate portion between the upper part
case portion 41 and the lower part case portion 42, and a supply
space portion T is formed at an outer circumference-side of the
separation unit 43 at a lower side relative to the dividing wall
44. As well as the cylinder head cover 5, each of the upper part
case portion 41, the lower part case portion 42, the separation
unit 43 and the dividing wall 44 is formed by resin material
including nylon, for example.
[0031] The separation unit 43 includes a cylindrical portion 43A
and a funnel-shaped portion 43B integrally formed at a lower side
of the cylindrical portion 43A. The separation unit 43 is provided
with an opening portion 43H formed at an outer circumference of the
cylindrical portion 43A to be in communication with the supply
space portion T. The separation unit 43 is provided with a hole
portion 43C formed at a lower end of the funnel-shaped portion 43B
to be in communication with an inside of the cylinder head cover 5.
A through hole 44A is formed at the dividing wall 44 that is at an
upper position of the cylindrical portion 43A of the separation
unit 43.
[0032] Due to the foregoing configuration, in a case where the
blow-by gas is supplied to the supply space portion T, the gas
including therein the oil mist is introduced from the opening
portion 43H to an inside of the cylindrical portion 43A of the
separation unit 43 in a tangential direction, and accordingly the
gas swirls as the gas is introduced thereto. The oil mist is
gathered, collected and separated by an effect of centrifugal force
due to the swirling of the gas. The gathered and collected oil mist
is sent from an inner surface of the funnel-shaped portion 43B to
the hole portion 43C, and then is sent out to the inside of the
cylinder head cover 5 via the hole portion 43C. In addition, the
blow-by gas from which the oil mist has been removed is led from
the through hole 44A of the dividing wall 44 to the gas space
portion S.
[0033] The PCV valve 30 is mounted on the upper part case portion
41 in a state where the PCV valve 30 is in communication with the
gas space portion (the internal space portion) S of the upper part
case portion 41. Thus, the upper part case portion 41 serves as a
resin cover which forms, together with the cylinder head cover 5,
the internal space portion (the gas space portion S) between the
upper part case portion 41 and the cylinder head 1 of the engine E,
and a valve mounting through hole 41A is formed at the upper part
case portion 41 to be transversely arranged.
[0034] The PCV valve 30 is provided with a valve main body 31, a
valve body 32 accommodated inside the valve main body 31, a support
member 33 preventing the valve body 32 from falling off the valve
main body 31 and a spring 34 biasing the valve body 32 in a close
direction. A hole portion 33A is formed at the support member
33.
[0035] The valve main body 31 is integrally provided with a
connection cylindrical portion 31A connected to the gas return path
23, a cylindrical main body portion 31B forming an accommodation
portion for the valve body 32 and an annular collar portion 31C
including, for example, a hexagonal configuration and a different
diameter. A male screw portion 31D is formed at an outer
circumferential portion of the cylindrical main body portion 31B.
The valve main body 31, the valve body 32, the support member 33
and the spring 34 are assumed to be formed by resin material,
however, all of them or part of them can be formed by metal
material.
[0036] The cylindrical main body portion 31B corresponds to a valve
case portion which is inserted, from outside the upper part case
portion 41, through the valve mounting through hole 41A and the
cylindrical main body portion 31B is inserted through the through
hole 41A in a state where an insertion depth is restricted by a
contact of the annular collar portion 31C and the upper part case
portion 41 with each other. A metal fixture 25 threadedly engages,
from inside the upper part case portion 41, with the male screw
portion 31D of the cylindrical main body portion 31B inserted
through the through hole 41A, and the PCV valve 30 is fixed to the
upper part case portion 41.
[0037] The metal fixture 25 is provided with a cylindrical screw
portion 26 formed with a female screw portion 26A which threadedly
engages with the male screw portion 31D of the cylindrical main
body portion 31B. The metal fixture 25 is insert molded in the
upper part case portion 41 in such a manner that the metal fixture
25 is prevented from turning and in such a manner that part of the
cylindrical screw portion 26 is exposed to the gas space portion S,
and the whole of the metal fixture 25 is made of metal having a
high coefficient of thermal conductivity, including aluminum alloy
and/or copper alloy, for example.
[0038] The part of the cylindrical screw portion 26, the part
including a portion which is not embedded in the upper part case
portion 41 and including a female screw portion with which the male
screw portion 31D does not engage, is exposed to the gas space
portion S, and thus the metal fixture 25 is configured to be heated
with heat possessed by hot temperature atmosphere including the
blow-by gas of the gas space portion S.
[0039] The metal fixture 25 is applicable to any PCV valve 30 or to
any cylindrical main body portion (the valve case portion) 31B, and
can be used as a common part. Therefore, the PCV valve 30 itself
can be manufactured inexpensively without using the metal. In
addition, the use of the common metal fixture 25 reduces a
manufacturing unit price and makes an inventory control easy,
thereby even more increasing efficiency of the mounting structure
of the PCV valve 30.
[0040] The valve main body 31 is fixed to the upper part case
portion 41 in a state where the annular collar portion 31C and the
cylindrical screw portion 26 sandwich a vicinity around the through
hole 41A of the upper part case portion 41. Accordingly, a portion
41B of the upper part case portion 41, the portion 41B being
sandwiched by the annular collar portion 31C and the cylindrical
screw portion 26, functions as an annular seal material sealing a
gap between the cylindrical main body portion 31B and the through
hole 41A.
Second Embodiment
[0041] FIG. 3 illustrates a second embodiment of the present
invention. In the present embodiment, the metal fixture 25 is
integrally provided with the cylindrical screw portion 26 that is
insert molded in the upper part case portion 41 in a manner that
the part of the cylindrical screw portion 26 is exposed to the gas
space portion S, and the metal fixture 25 is integrally provided
with a heat receiving portion 27 including a plate shape and
extended from the cylindrical screw portion 26 to protrude
downwardly along a cylinder radial direction into the gas space
portion S.
[0042] The heat receiving portion 27 is ideally formed in such a
configuration that does not easily hinder the flow of the blow-by
gas in the gas space portion S. In addition, the heat receiving
portion 27 may be provided as a flow passage forming member that
forms a flow passage of the blow-by gas in the gas space portion S.
The other configuration is similar to the first embodiment.
Other Embodiment
[0043] 1. According to the PCV valve mounting structure of the
present invention, the whole of the metal fixture, which threadedly
engages with the valve case portion from inside the resin cover,
can be exposed to the internal space portion of the resin cover.
[0044] 2. According to the PCV valve mounting structure of the
present invention, the valve case portion can be inserted through
the valve mounting through hole, which is formed at the cylinder
head cover made of resin, and at least part of the metal fixture,
which is threadedly engaged with the valve case portion from inside
the cylinder head cover, can be exposed to the internal space
portion of the cylinder head cover.
INDUSTRIAL APPLICABILITY
[0045] The PCV valve mounting structure of the present invention is
applicable to various internal combustion engines provided with a
PCV valve.
EXPLANATION OF REFERENCE NUMERALS
[0046] 1 cylinder head
[0047] 25 metal fixture
[0048] 26 cylindrical screw portion
[0049] 27 heat receiving portion
[0050] 30 PCV valve
[0051] 31B cylindrical main body portion (valve case portion)
[0052] 31D screw portion
[0053] 41 upper part case portion (resin cover)
[0054] 41A valve mounting through hole
[0055] E internal combustion engine
[0056] S gas space portion (internal space portion)
* * * * *