U.S. patent application number 14/774067 was filed with the patent office on 2016-01-21 for valve opening/closing timing control device, and production method for drive side rotational body of valve opening/closing timing control device.
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 Kazunari ADACHI, Takeo ASAHI, Yuji NOGUCHI, Tadashi SUGIMOTO.
Application Number | 20160017772 14/774067 |
Document ID | / |
Family ID | 51689359 |
Filed Date | 2016-01-21 |
United States Patent
Application |
20160017772 |
Kind Code |
A1 |
ASAHI; Takeo ; et
al. |
January 21, 2016 |
VALVE OPENING/CLOSING TIMING CONTROL DEVICE, AND PRODUCTION METHOD
FOR DRIVE SIDE ROTATIONAL BODY OF VALVE OPENING/CLOSING TIMING
CONTROL DEVICE
Abstract
A valve opening/closing timing control device includes a housing
main body that includes an opening which opens to at least one side
in a direction along a rotational axis and a cover plate closing
the opening by making contact with an end surface of the opening,
the drive side rotational body rotating synchronously with a
crankshaft, and a driven side rotational body housed within the
drive-side rotational body and defining an advance chamber and a
retardation chamber relative to an inner peripheral surface of the
housing main body, the driven-side rotational body rotating
integrally with a camshaft and coaxially with the rotational axis.
In addition, the housing main body includes a hard layer formed at
least at the inner peripheral surface of the housing main body in a
surface thereof excluding the end surface of the opening.
Inventors: |
ASAHI; Takeo; (Anjo-shi,
JP) ; NOGUCHI; Yuji; (Obu-shi, JP) ; ADACHI;
Kazunari; (Chiryu-shi, JP) ; SUGIMOTO; Tadashi;
(Toyama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN SEIKI KABUSHIKI KAISHA |
Aichi |
|
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi, Aichi
JP
|
Family ID: |
51689359 |
Appl. No.: |
14/774067 |
Filed: |
March 14, 2014 |
PCT Filed: |
March 14, 2014 |
PCT NO: |
PCT/JP2014/056960 |
371 Date: |
September 9, 2015 |
Current U.S.
Class: |
123/90.17 ;
123/90.31; 205/122 |
Current CPC
Class: |
C25D 11/022 20130101;
F01L 1/3442 20130101; F01L 2001/34479 20130101; F01L 2303/00
20200501; C25D 7/10 20130101; F01L 2301/00 20200501; C25D 11/04
20130101; F01L 1/356 20130101 |
International
Class: |
F01L 1/356 20060101
F01L001/356; C25D 7/10 20060101 C25D007/10; C25D 11/02 20060101
C25D011/02; C25D 11/04 20060101 C25D011/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 10, 2013 |
JP |
2013-082178 |
Claims
1. A valve opening/closing timing control device comprising: a
drive side rotational body including a housing main body that
includes an opening which opens to at least one side in a direction
along a rotational axis and a cover plate closing the opening by
making contact with an end surface of the opening, the drive side
rotational body rotating synchronously with a crankshaft; and a
driven side rotational body housed within the drive side rotational
body and defining an advance chamber and a retardation chamber
relative to an inner peripheral surface of the housing main body,
the driven side rotational body rotating integrally with a camshaft
and coaxially with the rotational axis, wherein the housing main
body includes a hard layer formed at least at the inner peripheral
surface of the housing main body in a surface thereof excluding the
end surface of the opening.
2. The valve opening/closing timing control device according to
claim 1, wherein the housing main body is in an annular form and
the hard layer at the inner peripheral surface is formed up to the
same position as the end surface of the opening in an axis
direction of the housing main body.
3. A production method for a drive side rotational body of a valve
opening/closing timing control device, the valve opening/closing
timing control device including: a drive side rotational body
including at least one housing main body that includes an opening
which opens to at least one side in a direction along a rotational
axis and a cover plate closing the opening by making contact with
an end surface of the opening, the drive side rotational body
rotating synchronously with a crankshaft; and a driven side
rotational body housed within the drive side rotational body and
defining an advance chamber and a retardation chamber relative to
an inner peripheral surface of the housing main body, the driven
side rotational body rotating integrally with a camshaft and
coaxially with the rotational axis, the production method
comprising forming a hard layer at least at the inner peripheral
surface of the housing main body in a region thereof excluding the
end surface of the opening.
4. The production method for the drive side rotational body
according to claim 3, wherein the housing main body is made of an
aluminum material and the end surface of the opening of the housing
main body is covered by a rubber member constituted by at least two
types of rubber materials including different hardness, the rubber
material including a high hardness in the rubber member is disposed
at a portion making contact with an edge portion of the end surface
of the opening in a vicinity of the inner peripheral surface of the
housing main body among edge portions of the end surface of the
opening.
5. The production method for the drive side rotational body
according to claim 3, wherein the hard layer is formed at least at
an inner peripheral surface of a cylinder body among the inner
peripheral surface and an outer peripheral surface of the cylinder
body, the cylinder body is cut along a cutting-plane line which is
specified at the outer peripheral surface depending on a thickness
dimension of the housing main body to form the drive side
rotational body.
Description
TECHNICAL FIELD
[0001] The present invention relates to a valve opening/closing
timing control device and a production method for a drive side
rotational body of the valve opening/closing timing control device
including a drive side rotational body rotating synchronously with
a crankshaft of an internal combustion engine and a driven side
rotational body arranged at an inner peripheral side of the drive
side rotational body to be coaxial therewith and rotating
integrally with a camshaft for opening and closing valves of the
internal combustion engine.
BACKGROUND ART
[0002] A valve opening/closing timing control device controls a
rotational phase of a driven side rotational body relative to a
housing main body constituting a drive side rotational body to
thereby change an opening and closing timing of an intake valve or
an exhaust valve of an internal combustion engine. At this time, an
inner peripheral surface of the housing main body and a partition
member, for example, provided at the driven side rotational body
slide on each other. At such a sliding portion, a seal member is
provided to inhibit oil leakage from a hydraulic chamber within the
housing main body. Nevertheless, in a case where the housing main
body is formed of metal such as aluminum material, for example, the
inner peripheral surface of the housing main body may be easily
worn by the sliding with the seal member, for example, which is a
cause of oil leakage. Thus, a valve opening/closing timing control
device as disclosed in Patent document 1 where a hard layer such as
coating of self-lubricating resin and alumite coating, for example,
is formed at the inner peripheral surface of the housing main body
is proposed.
DOCUMENT OF PRIOR ART
Patent Document
[0003] Patent document 1: JP2001-132415A
OVERVIEW OF INVENTION
Problem to be Solved by Invention
[0004] In the valve opening/closing timing control device in Patent
document 1, in order to perform an alumite treatment at an entire
surface of the housing main body, an end surface of an opening in
addition to the inner peripheral surface is formed with the hard
layer. An alumite layer (hard layer) usually grows in a vertical
direction relative to a surface of aluminum material. Nevertheless,
the growth of the alumite layer at an edge portion formed by the
inner peripheral surface and the end surface of the opening is
unstable and a surface form of the edge portion may become
unevenness. In a case where a cover plate is mounted to the housing
main body, the unstable surface form is sandwiched between mating
surfaces of the housing main body and the cover plate, which
generates a gap therebetween. The gap is a cause of oil leakage
from the inside of the housing main body. In addition, the hard
layer is difficult to be formed at the edge portion of the end
surface of the opening of the housing main body and instability may
occur in a direction where the hard layer is formed. Accordingly,
the hard layer at the edge portion may be formed thinner relative
to the driven side rotational body or formed to protrude from the
end surface of the opening of the housing main body. Thus, a gap is
generated between the hard layer in the vicinity of the end surface
of the opening of the housing main body and the driven side
rotational body or between the end surface of the opening and the
cover plate.
[0005] In addition, a clearance between the driven side rotational
body and the cover plate is desirably specified as small as
possible within a range not disturbing a sliding movement of the
driven side rotational body so as to avoid oil leakage.
Nevertheless, in a case where the hard layer is formed at the end
surface of the opening of the housing main body and the thickness
of the end surface portion of the opening of the housing main body
is uneven, setting of the aforementioned clearance is difficult,
which leads to deterioration of control responsiveness because of
the generation of oil leakage
[0006] The object of the present invention is to provide a valve
opening/closing timing control device where oil leakage is
inhibited from occurring, for example, from a gap between members
constituting a drive side rotational body while maintaining
lubrication and abrasion resistance of a slide surface of a housing
main body.
Means for Solving Problem
[0007] A characteristic construction of a valve opening/closing
timing control device according to the present invention for
achieving the aforementioned object includes a drive side
rotational body including a housing main body that includes an
opening which opens to at least one side in a direction along a
rotational axis and a cover plate closing the opening by making
contact with an end surface of the opening, the drive side
rotational body rotating synchronously with a crankshaft, and a
driven side rotational body housed within the drive side rotational
body and defining an advance chamber and a retardation chamber
relative to an inner peripheral surface of the housing main body,
the driven side rotational body rotating integrally with a camshaft
and coaxially with the rotational axis. In addition, the housing
main body includes a hard layer formed at least at the inner
peripheral surface of the housing main body in a surface thereof
excluding the end surface of the opening.
[0008] As in the present construction, in the housing main body of
the drive side rotational body, the hard layer is provided to be
formed at the inner peripheral surface via which at least a portion
of the driven side rotational body slides relative to the drive
side rotational body. Thus, abrasion resistance of the housing main
body may improve. Meanwhile, the hard layer is inhibited from being
formed at the end surface of the opening of the housing main body
so that adhesion properties at a mating portion between the end
surface of the opening and the cover plate is enhanced at the time
of assembly of the drive side rotational body. Thus, leakage of
hydraulic oil that fills the advance chamber or the retardation
chamber is restrained, which may obtain the valve opening/closing
timing control device with improved operation responsiveness.
[0009] In the valve opening/closing timing control device according
to the present invention, it is favorable that the housing main
body is in an annular form and the hard layer at the inner
peripheral surface is formed up to the same position as the end
surface of the opening in an axis direction of the housing main
body.
[0010] As in the present construction, in a case where the hard
layer at the inner peripheral surface is formed up to the same
position as the end surface of the opening in the axis direction of
the housing main body, a pressure-receiving area of the hard layer
relative to a partition portion provided at the driven side
rotational body increases, which increases the abrasion resistance
of the hard layer. In addition, because the partition portion of
the driven side rotational body makes contact with the hard layer
which is formed up to the same position as the end surface of the
opening, the leakage of hydraulic oil may be restrained.
[0011] A characteristic measure of a production method for a drive
side rotational body of a valve opening/closing timing control
device according to the present invention, the valve
opening/closing timing control device including a drive side
rotational body including at least one housing main body that
includes an opening which opens to at least one side in a direction
along a rotational axis and a cover plate closing the opening by
making contact with an end surface of the opening, the drive side
rotational body rotating synchronously with a crankshaft, and a
driven side rotational body housed within the drive side rotational
body and defining an advance chamber and a retardation chamber
relative to an inner peripheral surface of the housing main body,
the driven side rotational body rotating integrally with a camshaft
and coaxially with the rotational axis, the characteristic measure
of the production method includes forming a hard layer at least at
the inner peripheral surface of the housing main body in a region
thereof excluding the end surface of the opening.
[0012] According to the present production method, when forming the
housing main body of the drive side rotational body, the hard layer
is formed at the inner peripheral surface of the housing main body,
for example, to thereby enhance the abrasion resistance of the
housing main body. Meanwhile, in the present embodiment, the end
surface of the opening is covered at the time of forming the hard
layer at the inner peripheral surface of the housing main body.
Thus, the hard layer is inhibited from being formed at the end
surface of the opening of the housing main body. Accordingly, the
adhesion properties between the end surface of the opening and the
cover plate are enhanced. The leakage of hydraulic oil that fills
the advance chamber or the retardation chamber is restrained, which
obtains the valve opening/closing timing control device with the
improved operation responsiveness. In addition, it is not required
to perform a specific process on the end surface of the opening
after a hardening process of the inner peripheral surface is
completed. Thus, the housing main body including an expected
performance may be effectively obtained.
[0013] In the production method for the drive side rotational body
of the valve opening/closing timing control device according to the
present invention, the housing main body is made of an aluminum
material and the end surface of the opening of the housing main
body is covered by a rubber member constituted by at least two
types of rubber materials including different hardness. The rubber
material including a high hardness in the rubber member is disposed
at a portion making contact with an edge portion of the end surface
of the opening in a vicinity of the inner peripheral surface of the
housing main body among edge portions of the end surface of the
opening.
[0014] In a case where the housing main body is made of the
aluminum material, an alumite process is often used as a hardening
process of the aluminum material. In the present embodiment, the
alumite process is performed on the inner peripheral surface of the
housing main body while not being performed on the end surface of
the opening at which the cover plate is mounted. Accordingly, while
the abrasion resistance of the housing main body is enhanced, the
leakage of hydraulic oil is restrained. However, in doing so, a
sound alumite layer is necessarily formed up to a boundary position
of the inner peripheral surface relative to the end surface of the
opening specifically by the alumite process performed on the inner
peripheral surface of the housing main body.
[0015] Therefore, in the present production method, the rubber
material including a high hardness is used to make contact with the
edge portion of the end surface of the opening in the rubber member
that covers the end surface of the opening of the housing main
body. The rubber material including a low hardness is used to a
portion facing other than the edge portion in the end surface of
the opening of the housing main body. In a case where the
aforementioned rubber member is pressed against the end surface of
the opening, the rubber member is comparatively compressively
deformed and the rubber member that protrudes from the edge portion
of the end surface of the opening is pushed out to a center side of
the inner peripheral surface. In the present embodiment, the rubber
member at the aforementioned portion includes a high hardness so
that such push-out of the rubber material may be reduced.
Accordingly, the alumite layer (hard layer) may soundly grow to the
boundary position of the inner peripheral surface relative to the
end surface of the opening.
[0016] In the production method for the drive side rotational body
of the valve opening/closing timing control device according to the
present invention, the hard layer is formed at least at an inner
peripheral surface of a cylinder body among the inner peripheral
surface and an outer peripheral surface of the cylinder body. The
cylinder body is cut along a cutting-plane line which is specified
at the outer peripheral surface depending on a thickness dimension
of the housing main body to form the drive side rotational
body.
[0017] In the present construction, plural housing main bodies
where the hard layer is inhibited from being formed at the end
surface of the opening may be produced from the cylinder member.
The housing main body produced from a portion of the cylinder
member in the vicinity of a center thereof includes the end surface
of the opening where the hard layer is not formed, only by the
cutting along the cutting-plane line. The hard layer formed at the
end surface at each side of the opening of the cylinder member may
be scraped by performing a cutting process, for example.
Accordingly, the housing main body where the hard layer is formed
at least at the inner peripheral surface may be effectively
produced.
BRIEF DESCRIPTION OF DRAWINGS
[0018] [FIG. 1] is an entire block diagram illustrating a valve
opening/closing timing control device.
[0019] [FIG. 2] is a cross-sectional view on arrows II-II in FIG.
1.
[0020] [FIG. 3] is a perspective view of a housing main body where
a hard layer is formed.
[0021] [FIG. 4] is a perspective view of the housing main body and
a covering member.
[0022] [FIG. 5] is a perspective view of a covering member
according to another embodiment.
[0023] [FIG. 6] is a partial cross-sectional view illustrating a
state where the covering member is provided at the housing main
body.
[0024] [FIG. 7] is a perspective view of a cylinder member.
MODE FOR CARRYING OUT THE INVENTION
Entire Configuration
[0025] As illustrated in FIG. 1, a valve opening/closing timing
control device includes a housing 1 (example of a drive side
rotational body) rotating synchronously with a crankshaft El of an
engine E and an inner rotor 3 (example of a driven side rotational
body) housed within the housing 1 and rotating integrally with a
camshaft 2 of the engine E. The housing 1 and the inner rotor 3 are
arranged on an identical axis X.
Housing and Rotor
[0026] As illustrated in FIGS. 1 and 2, the housing 1 includes a
front plate 4 (example of a cover plate) provided at a front side,
i.e., at an opposite side from the camshaft 2, a rear plate 5
(example of the cover plate) provided at a rear side, i.e., at a
side where the camshaft 2 is provided, and an outer rotor 6
(example of a housing main body) disposed between the front plate 4
and the rear plate 5. A sprocket is formed at an outer peripheral
portion of the rear plate 5. The front plate 4, the rear plate 5,
and the outer rotor 6 are fixed together by a screw. The outer
rotor 6 includes an opening 24 (see FIG. 3) that opens to at least
one side in a direction along the rotational axis X. The front
plate 4 and the rear plate 5 occlude the opening 24 by making
contact with respective end surfaces 25 of the opening 24 of the
outer rotor 6. The sprocket may not be formed at the outer
peripheral portion of the rear plate 5 and may be formed at an
outer peripheral portion of the outer rotor 6.
[0027] In a case where the crankshaft E1 is driven to rotate, a
rotation driving force thereof is transmitted to the rear plate 5
via a power transmission member E2. The outer rotor 6 is then
driven to rotate in a rotation direction S (see FIG. 2). In
association with the rotational driving of the outer rotor 6, the
inner rotor 3 is driven to rotate in the rotation direction S,
which causes the camshaft 2 to rotate to thereby press down an
intake valve (not illustrated) of the engine by a cam (not
illustrated) provided at the camshaft 2.
[0028] As illustrated in FIG. 2, plural protruding portions 8
protruding to a radially inner side are formed at an inner
peripheral portion of the outer rotor 6. The protruding portions 8
are arranged to be spaced away from one another along the rotation
direction S. Plural partition portions 9 protruding to a radially
outer side are formed at an outer peripheral portion of the inner
rotor 3. The partition portions 9 are arranged to be spaced away
from one another along the rotation direction S in the same way as
the protruding portions 8. A void between an inner peripheral
surface 26 of the outer rotor 6 and the inner rotor 3 is divided
into plural hydraulic chambers. The hydraulic chambers are divided
into advance chambers 11 and retardation chambers 12 by the
partition portions 9. In order to inhibit leakage of engine oil
between the advance chambers 11 and the retardation chambers 12,
seal members SE are provided at positions at the protruding
portions 8 facing an outer peripheral surface of the inner rotor 3
and at positions at the partition portions 9 facing an inner
peripheral surface of the outer rotor 6.
[0029] The outer rotor 6 is formed of sintered metal of stainless,
iron, copper alloy and the like, aluminum, or aluminum alloy, for
example. In the outer rotor 6, as illustrated in FIG. 3, a hard
layer 30 is formed at the inner peripheral surface 26 in the
surface of the outer rotor 6 excluding the end surfaces 25 of the
opening 24.
[0030] The hard layer 30 is formed of fluorine resin such as
polytetrafluoroethylene resin (PTFE), for example, or hard resin
such as polyphenylene sulfide resin (PPS), polyimide resin (PI),
polyamide-imide resin (PAI), polyamide resin (PA), fully aromatic
polyester resin (ARPES), polyether ketone resin (PEK), and
polyetherether ketone resin (PEEK), for example. As a formation
method of the hard layer 30, an electrostatic powder coating
process, a derivative coating process, a fluidization dip coating
process, a spray coating process, a brushing process or the like
may be employed. The outer rotor 6 may be formed of aluminum
material and an alumite layer may be formed as the hard layer 30 at
the inner peripheral surface 26.
[0031] Accordingly, the hard layer 30 formed at least at the inner
peripheral surface 26 in the outer rotor 6 is provided to thereby
enhance abrasion resistance of the outer rotor 6 in a case where a
portion of the inner rotor 3 slides on the outer rotor 6.
Meanwhile, the hard layer 30 is inhibited from being formed at the
end surfaces 25 of the opening 24 of the outer rotor 6 so that
adhesion properties between the end surface 25 of the opening 24
and the front plate 4 are enhanced at the time of assembly of the
housing 1. Thus, leakage of hydraulic oil that fills the advance
chambers 11 or the retardation chambers 12 is restrained, which may
obtain the valve opening/closing timing control device with
improved operation responsiveness.
[0032] As illustrated in FIGS. 1 and 2, an advance passage 13 and a
retardation passage 14 are formed at inner portions of the inner
rotor 3, a connection member 22 and the camshaft 2. The advance
passage 13 connects each of the advance chambers 11 and a supply
and discharge mechanism KK which conducts and blocks supply and
discharge of engine oil. The retardation passage 14 connects each
of the retardation chambers 12 and the supply and discharge
mechanism KK.
[0033] The supply and discharge mechanism KK includes an oil pan,
an oil motor, a fluid control valve OCV which conducts and blocks
supply and discharge of engine oil relative to the advance passage
13 and the retardation passage 14, and an electronic control unit
ECU controlling an operation of the fluid control valve OCV. By the
control of the supply and discharge mechanism KK, a relative
rotational phase between the inner rotor 3 and the outer rotor 6 is
displaced in an advance direction (direction of an arrow S1 in FIG.
2) or in a retardation direction (direction of an arrow S2 in FIG.
2) or is maintained at any phase.
[0034] A lock mechanism RK locks the inner rotor 3 and the outer
rotor 6 at a predetermined relative rotational phase. The lock
mechanism RK is formed by a lock member 16 including an end portion
which is projectable and retractable in the direction along the
rotational axis X relative to a recess portion (not illustrated)
formed at the rear plate 5, the lock member 16 being provided at
one of the partition portions 9 of the inner rotor 3. In addition,
a hydraulic chamber (not illustrated) is provided for generating a
the surfa to the lock member 16. The aforementioned hydraulic
chamber is in communication with the advance passage 13 or the
retardation passage 14. According to the aforementioned
configuration, the lock mechanism RK is switched to a lock state
where the end portion of the lock member 16 enters the recess
portion by receiving a biasing force of a biasing member (not
illustrated) such as a compression spring, for example. In
addition, the lock mechanism RK is switched to a lock release state
where the end portion removes from the recess portion towards the
inner rotor 3 against the biasing force of the biasing member.
Production Method of Housing (Drive Side Rotational Body)
[0035] For example, in a case where the outer rotor 6 (example of
the housing main body) constituting the housing 1 is formed of
aluminum material, the alumite treatment is performed on the inner
peripheral surface 26 to form the hard layer 30. In order to form
such the hard layer 30, first, the end surfaces 25, 25 at opposed
sides of the opening 24 of the outer rotor 6 are covered by
covering members 40, 40 (see FIG. 4). Each of the covering members
40 is formed by a hard rubber member or a copper plate, for
example, so as to extend along the opening 24 of the outer rotor 6.
The covering member 40 illustrated in FIG. 4 includes substantially
the same configuration as the end surface 25 of the opening 24 of
the outer rotor 6, however, any configuration of the covering
member 40 is acceptable as long as the covering member 40 fully
covers the end surface 25 of the opening 24 of the outer rotor
6.
[0036] After the end surfaces 25, 25 of the opening 24 are covered
by the covering members 40, 40 (see FIG. 4), the hard layer 30 is
formed at least at the inner peripheral surface 26 in a region of
the surface of the outer rotor 6 excluding the end surfaces 25 of
the opening 24. As for the alumite treatment, a general method is
employed except for the usage of the covering members 40, 40. The
hard layer 30 may be formed at an outer peripheral surface 27 along
with the inner peripheral surface 26, instead of being formed only
at the inner peripheral surface 26. After the hard layer 30 is
formed at the outer rotor 6, each of the covering members 40 is
removed from each of the end surfaces 25 of the opening 24 so that
the front plate 4 and the rear plate 5 are mounted to the end
surfaces 25, 25 of the opening 24 to complete the housing 1.
[0037] In the housing 1, if the outer rotor 6 and one of the front
plate 4 and the rear plate 5 are integrally formed, the covering
member 40 is arranged only at the end surface 25 at one side of the
opening 24.
[0038] Accordingly, the hard layer 30 is formed at the inner
peripheral surface 26 of the outer rotor 6 to thereby improve the
abrasion resistance of the outer rotor 6. Meanwhile, the hard layer
30 is inhibited from being formed at the end surfaces 25 of the
opening 24 of the outer rotor 6. Thus, in a case where the front
plate 4 is mounted to the end surface 25 of the opening 24 of the
outer rotor 6, the front surface of the end surface 25 of the
opening 24 is likely to make close contact with the front plate 4.
As a result, leakage of hydraulic oil that fills the advance
chambers 11 or the retardation chambers 12 is restrained, which
obtains the valve opening/closing timing control device with the
improved operation responsiveness.
[0039] In addition, in the present production method, the end
surfaces 25 of the opening 24 are covered at the time of forming
the hard layer 30 at the inner peripheral surface 26. Thus, it is
not required to perform a specific process on the end surfaces 25
of the opening 24 after the hardening process of the inner
peripheral surface 26 is completed. Thus, the housing member
including an expected performance may be effectively obtained.
[0040] In order to bring the hard layer 30 formed at the inner
peripheral surface 26 to securely make contact with a portion of
the inner rotor 3 over the entire width thereof, the sound alumite
layer (hard layer) 30 is necessarily formed up to a boundary
position relative to each of the end surfaces 25 of the opening 24.
Nevertheless, in a case where the rubber member (example of the
covering member) 40 is pressed against the end surface 25 of the
opening 24 of the outer rotor 6, for example, the rubber member 40
is comparatively compressively deformed. A portion of the rubber
member 40 protruding from an edge portion 25a of the end surface 25
of the opening 24 is pushed out to a center side of the inner
peripheral surface 26. In a case where such push-out of the rubber
member 40 increases, a void where the alumite layer (hard layer) 30
should grow is blocked by the rubber member 40 at the boundary
position of the inner peripheral surface 26 relative to the end
surface 25 of the opening 24, which makes the sound alumite layer
(hard layer) 30 difficult to be formed.
[0041] Then, as illustrated in FIGS. 5 and 6, the rubber member 40
covering each of the end surfaces 25 of the opening 24 is
constituted by two difference types of rubber materials 41 and 42
including different hardness. In the rubber member 40, the rubber
material 41 including a high hardness is disposed at a portion
making contact with the edge portion 25a in the vicinity of the
inner peripheral surface 26 of the outer rotor 6 among edge
portions of the end surface 25 of the opening 24 and the rubber
material 42 including a low hardness is disposed at a portion
facing other than the edge portion 25a of the end surface 25 of the
opening 24.
[0042] As mentioned above, in the rubber member 40, the rubber
material 41 that makes contact with the edge portion 25a of the end
surface 25 of the opening 24 includes a high hardness to thereby
reduce the push-out of the rubber material 41 to the center side of
the inner peripheral surface 26. Accordingly, the alumite layer
(hard layer) 30 may grow soundly up to the boundary position of the
inner peripheral surface 26 relative to the end surface 25 of the
opening 24 in the inner peripheral surface 26. The improved hard
layer 30 may be formed at the inner peripheral surface 26 of the
outer rotor 6 over the direction of the rotational axis X.
[0043] That is, the hard layer 30 at the inner peripheral surface
26 is formed up to the same position as the end surface 25 of the
opening 24 in the axis direction of the outer rotor 6. Accordingly,
a pressure-receiving area of the hard layer 30 relative to the
partition portion 9 of the inner rotor 3 increases, which increases
the abrasion resistance of the hard layer 30. In addition, because
the partition portion 9 of the inner rotor 3 makes contact with the
hard layer 30 which is formed up to the same position as the end
surface 25 of the opening 24, leakage of hydraulic oil may be
restrained.
Another Embodiment
[0044] (1) In the aforementioned embodiment, an example where the
end surfaces 25 of the opening 24 of the single outer rotor 6 are
covered by the covering members 40 is explained. As illustrated in
FIG. 7, plural outer rotors 6 may be produced by using an elongated
cylinder member 60. The cylinder member 60 may be formed by
extrusion molding, for example. Plural cutting-plane lines C are
provided at an outer peripheral surface of the cylinder member 60.
The cutting-plane lines C are specified depending on a thickness
dimension along the axis direction of the outer rotor 6. In order
to produce the outer rotors 6, the hard layer 30 is formed at only
the inner peripheral surface 26 of the cylinder member 60 or at
both the inner peripheral surface 26 and the outer peripheral
surface 27, and thereafter the cylinder member 60 is cut along the
cutting-plane lines C. The hard layer formed at the end surface 25
at each end of the opening 24 of the cylinder member 60 is scraped
by performing a cutting process.
[0045] Accordingly, the plural outer rotors 6 at each of which the
hard layer 30 is inhibited from being formed at the end surface 25
of the opening 24 may be produced from the cylinder member 60. The
outer rotor 6 that is produced from a portion of the cylinder
member 60 in the vicinity of a center thereof includes the end
surfaces 25 of the opening 24 where the hard layer 30 is not
formed, only by the cutting along the cutting-plane lines C.
Accordingly, the plural outer rotors 6 may be manufactured by
covering the end surfaces 25 at the opposed sides of the opening 24
of the cylinder member 60, which leads to an effective production
of the outer rotors 6.
[0046] (2) In the aforementioned embodiment, an example where the
housing 1 is constituted by three members of the outer rotor 6, the
front plate 4 and the rear plate 5 is explained. Alternatively, the
housing 1 may be constituted by the outer rotor 6 at which one of
the front plate 4 and the rear plate 5 is integrally formed.
[0047] (3) In the aforementioned embodiment, an example where the
rubber member 40 is constituted by two types of the rubber
materials 41 and 42 including the different hardness is explained.
Alternatively, the rubber member 40 may be constituted by three or
more than three types of rubber materials including different
hardness as long as the push-out of the rubber material to the
center side of the inner peripheral surface 26 from the end surface
25 of the opening 24 is reduced.
INDUSTRIAL AVAILABILITY
[0048] The present invention is applicable to a valve
opening/closing timing control device of an internal combustion
engine for an automobile or others.
EXPLANATION OF REFERENCE NUMERALS
[0049] 1 housing (drive side rotational body) [0050] 2 camshaft
[0051] 3 inner rotor (driven side rotational body) [0052] 4 front
plate (cover plate) [0053] 5 rear plate (cover plate) [0054] 6
outer rotor (housing main body) [0055] 11 advance chamber [0056] 12
retardation chamber [0057] 24 opening [0058] 25 end surface [0059]
25a edge portion [0060] 26 inner peripheral surface [0061] 30 hard
layer [0062] 40 covering member [0063] 41 rubber material including
high hardness [0064] 42 rubber material including low hardness
[0065] 60 cylinder member [0066] X rotational axis
* * * * *