U.S. patent application number 13/583710 was filed with the patent office on 2013-02-21 for surface treatment apparatus.
This patent application is currently assigned to AISIN SEIKI KABUSHIKI KAISHA. The applicant listed for this patent is Masaki Kato, Daishi Kobayashi, Kazuhiro Tatsumoto. Invention is credited to Masaki Kato, Daishi Kobayashi, Kazuhiro Tatsumoto.
Application Number | 20130043122 13/583710 |
Document ID | / |
Family ID | 45003678 |
Filed Date | 2013-02-21 |
United States Patent
Application |
20130043122 |
Kind Code |
A1 |
Kobayashi; Daishi ; et
al. |
February 21, 2013 |
SURFACE TREATMENT APPARATUS
Abstract
Disclosed is a surface treatment apparatus including one of a
positive electrode member and a negative electrode member to be
electrically connected to a treatment-object article made of metal
and having an annular treatment-object area in an outer
circumferential face thereof, a frame member having a
non-conductive inner circumferential face opposed with a gap to the
outer circumferential face and to the annular treatment-object
area, a non-conductive elastic seal member capable of forming an
electrolysis solution path along the annular treatment-object area
by sealing the gaps between portions of the outer circumferential
face opposed to each other across the annular treatment-object area
and the inner circumferential face, the other one of the positive
electrode member and the negative electrode member having a
bar-like shape with a leading end portion that protrudes into the
electrolysis solution path toward the treatment-object article, and
an electrolysis solution circulating means for circulating an
amount of electrolysis solution along the electrolysis solution
path.
Inventors: |
Kobayashi; Daishi;
(Kariya-shi, JP) ; Kato; Masaki; (Kariya-shi,
JP) ; Tatsumoto; Kazuhiro; (Kariya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kobayashi; Daishi
Kato; Masaki
Tatsumoto; Kazuhiro |
Kariya-shi
Kariya-shi
Kariya-shi |
|
JP
JP
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi
JP
|
Family ID: |
45003678 |
Appl. No.: |
13/583710 |
Filed: |
March 3, 2011 |
PCT Filed: |
March 3, 2011 |
PCT NO: |
PCT/JP11/54920 |
371 Date: |
September 10, 2012 |
Current U.S.
Class: |
204/237 |
Current CPC
Class: |
C25D 17/12 20130101;
C25D 5/02 20130101; C25D 11/005 20130101 |
Class at
Publication: |
204/237 |
International
Class: |
C25D 17/00 20060101
C25D017/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 2010 |
JP |
2010-121414 |
Claims
1. A surface treatment apparatus comprising: one of a positive
electrode member and a negative electrode member to be electrically
connected to a treatment-object article made of metal and having an
annular treatment-object area in an outer circumferential face
thereof; a frame member having a non-conductive inner
circumferential face opposed with a gap to the outer
circumferential face and to the annular treatment-object area; a
non-conductive elastic seal member capable of forming an
electrolysis solution path along the annular treatment-object area
by sealing the gaps between portions of the outer circumferential
face opposed to each other across the annular treatment-object area
and the inner circumferential face; the other one of the positive
electrode member and the negative electrode member having a
bar-like shape with a leading end portion that protrudes into the
electrolysis solution path toward the treatment-object article; and
an electrolysis solution circulating means for circulating an
amount of electrolysis solution along the electrolysis solution
path.
2. The surface treatment apparatus according to claim 1, wherein
the apparatus comprises a plurality of the other one of the
positive electrode members and the negative electrode members
having the bar-like shape disposed in distribution along the
circumferential direction of the electrolysis solution path.
3. The surface treatment apparatus according to claim 1, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape is disposed to protrude,
with its longitudinal direction being the direction perpendicular
to the outer circumferential face.
4. The surface treatment apparatus according to claim 1, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has an outer
circumferential face which is formed as a concave/convex face.
5. The surface treatment apparatus according to claim 1, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has a leading end
portion whose shape is a convex face.
6. The surface treatment apparatus according to claim 2, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape is disposed to protrude,
with its longitudinal direction being the direction perpendicular
to the outer circumferential face.
7. The surface treatment apparatus according to claim 2, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has an outer
circumferential face which is formed as a concave/convex face.
8. The surface treatment apparatus according to claim 3, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has an outer
circumferential face which is formed as a concave/convex face.
9. The surface treatment apparatus according to claim 2, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has a leading end
portion whose shape is a convex face.
10. The surface treatment apparatus according to claim 3, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has a leading end
portion whose shape is a convex face.
11. The surface treatment apparatus according to claim 4, wherein
the other one of the positive electrode member and the negative
electrode member having the bar-like shape has a leading end
portion whose shape is a convex face.
Description
TECHNICAL FIELD
[0001] The present invention relates to a surface treatment
apparatus.
BACKGROUND ART
[0002] A conventional surface treatment apparatus includes e.g. a
positive electrode member to be electrically connected to a
treatment-object article made of metal and having a circumferential
groove as an annular treatment-object area in the outer
circumferential face thereof, a frame member having an inner
circumferential face opposed with a gap relative to the outer
circumferential face and the circumferential groove, a
non-conductive elastic seal member capable of forming an
electrolysis solution path along the annular treatment-object area
by sealing the gaps between portions of the outer circumferential
face opposed to each other across the annular treatment-object area
and the inner circumferential face, a negative electrode member
provided in the electrolysis solution path, and an electrolysis
solution circulating means for circulating an amount of
electrolysis solution along the electrolysis solution path.
[0003] With the above-described surface treatment apparatus in
operation, as an electrolysis solution path is formed along the
annular treatment-object area provided in the outer circumferential
face of the treatment-object article and an amount of electrolysis
solution is circulated along this electrolysis solution path, a
surface treatment such as anodization treatment can be done on the
annular treatment-object area in an efficient manner.
[0004] In the case of the conventional surface treatment apparatus
described above, the frame member is made of a conductive material
and this frame member constitutes a negative electrode member
having an annular inner circumferential face opposed to the outer
circumferential face of the treatment-object article and the
annular treatment-object area (circumferential groove) with a gap
relative thereto respectively (see, e.g. Patent Document 1).
PRIOR ART DOCUMENT
Patent Document
[0005] Patent Document 1: Japanese Unexamined Patent Application
Publication No. 2003-119593 (paragraph [0024]).
SUMMARY OF THE INVENTION
Problem to be Solved by Invention
[0006] With the surface treatment apparatus described above, with
supply of electricity between and across the positive electrode
member and the negative electrode member at the time of a surface
treatment, a metal component such as copper dissolved in the
electrolysis solution that can easily changed into positive ion
tends to deposit and then adhere and accumulate on the surface of
the negative electrode member.
[0007] Further, with the conventional surface treatment apparatus,
because of the provision of the negative electrode member having an
annular inner circumferential face, there tends to occur uniform
adhesion/accumulation of the deposited metal along the entire inner
circumferential face of the negative electrode member. The
accumulated deposited metal results not only in decrease in the
path cross section area of the electrolysis solution path, but also
in hindrance of smooth circulation of the electrolysis
solution.
[0008] Incidentally, in case the frame member constitutes a
positive electrode member having an annular inner circumferential
face opposed to the outer circumferential face and the annular
treatment-object area of the treatment-object article with a gap
relative thereto respectively, a non-metal component such as a
chloride or a sulfide dissolved in the electrolysis solution that
can easily be changed into negative ion tends to deposit and then
adhere/accumulate on the surface of the positive electrode member.
Hence, a similar phenomenon tends to occur.
[0009] The temperature of the electrolysis solution becomes higher
in the vicinity of the surface of the annular treatment-object area
due to the heat generated in association with the electrode
reaction. And, if smooth circulation of the electrolysis solution
is hindered, increase in the temperature of the electrolysis
solution tends to occur.
[0010] Such increase in the temperature of the electrolysis
solution tends to result in burning of coating in the surface
treatment when a coating such as an alumite coating is formed in
the annular treatment-object area. More particularly, at the time
of anodizing treatment, there occurs non-uniformity of electric
current distribution or excess of current density, which causes a
burning-like outer appearance and may pose difficulty in effecting
a plurality of cycles of surface treatment operations with high
voltage in repetition with high efficiency.
[0011] The present invention has been made in view of the
above-described state of the art and its object is to provide a
surface treatment apparatus which allows a plurality of cycles of
surface treatment operations with high voltage to be effected in
repetition with high efficiency.
Means for Solving the Problem
[0012] According to a first characterizing feature of a surface
treatment apparatus relating to the present invention, the surface
treatment apparatus comprises:
[0013] one of a positive electrode member and a negative electrode
member to be electrically connected to a treatment-object article
made of metal and having an annular treatment-object area in an
outer circumferential face thereof;
[0014] a frame member having a non-conductive inner circumferential
face opposed with a gap to the outer circumferential face and to
the annular treatment-object area;
[0015] a non-conductive elastic seal member capable of forming an
electrolysis solution path along the annular treatment-object area
by sealing the gaps between portions of the outer circumferential
face opposed to each other across the annular treatment-object area
and the inner circumferential face;
[0016] the other one of the positive electrode member and the
negative electrode member having a bar-like shape with a leading
end portion that protrudes into the electrolysis solution path
toward the treatment-object article; and
[0017] an electrolysis solution circulating means for circulating
an amount of electrolysis solution along the electrolysis solution
path.
[0018] With the above-described arrangement, since the frame member
has a non-conductive inner circumferential face that is opposed
with a gap to the outer circumferential face and to the annular
treatment-object area, there occurs no deposition of a metal
component or a non-metal component on the inner circumferential
face of the frame member at the time of surface treatment.
[0019] Further, since the other one of the positive electrode
member and the negative electrode member having a bar-like shape
protrudes, the other one of the positive electrode member and the
negative electrode member can have a smaller surface area as
compared with the convention, so that the adhesion area for a
deposited component such as a metal component or a non-metal
component to the other one of the positive electrode member and the
negative electrode member can be small, and the adhesion strength
of the deposited component to the other of the positive electrode
component and the negative electrode component can be small.
[0020] And, since the other one of the bar-like positive or
negative electrode member has its leading end portion that
protrudes into the electrolysis solution path toward the
treatment-object article, any deposited component of weak adhesion
strength which may have adhered and accumulated on the other one of
the positive electrode member and the negative electrode member can
be gushed away by the impetus of the amount of electrolysis
solution that circulates along the electrolysis solution path, thus
being removed from the other one of the positive electrode member
and the negative electrode member. Hence, there will hardly occur
growth of any deposited component accumulated on the other one of
the bar-like positive or negative electrode member.
[0021] Therefore, smooth circulation of the electrolysis solution
in the electrolysis solution path can be maintained for an extended
period of time, whereby undesirable increase in the temperature in
the vicinity of the surface of the annular treatment-object area
can be restricted for an extended period of time, also.
[0022] Consequently, the inventive surface treatment apparatus
makes it possible to effect a plurality of cycles of surface
treatment with high voltage repeatedly in an efficient manner.
[0023] According to a second characterizing feature of the present
invention, the apparatus comprises a plurality of the other one of
the positive electrode members and the negative electrode members
having the bar-like shape disposed in distribution along the
circumferential direction of the electrolysis solution path.
[0024] With the above-described arrangement, as the intensify the
electric field generated between the other one of the bar-like
positive or negative electrode member and the annular
treatment-object area is dispersed along the annular
treatment-object area, it becomes easier to form a uniform
coating.
[0025] According to a third characterizing feature of the present
invention, the other one of the positive electrode member and the
negative electrode member having the bar-like shape is disposed to
protrude, with its longitudinal direction being the direction
perpendicular to the outer circumferential face.
[0026] With the above-described arrangement, an electric field can
be generated in right/left symmetry between the other positive
electrode member and the negative electrode member having the
bar-like shape and the annular treatment-object area located on the
opposed right and left sides relative thereto, so that a uniform
coating can be formed easily.
[0027] According to a fourth characterizing feature of the present
invention, the other one of the positive electrode member and the
negative electrode member having the bar-like shape has an outer
circumferential face which is formed as a concave/convex face.
[0028] With the above-described arrangement, the other bar-like one
of the positive electrode member and the negative electrode member
can have a large surface area for allowing conduction of a large
current therethrough, so that a coating of a desired thickness can
be readily formed in an efficient manner in a short time.
[0029] According to a fifth characterizing feature of the present
invention, the other one of the positive electrode member and the
negative electrode member having the bar-like shape has a leading
end portion whose shape is a convex face.
[0030] With the above-described arrangement, occurrence of electric
current concentration at the leading end portion near the
treatment-object article can be restricted, so that a spark will
hardly occur, and a unifomi coating can be formed easily.
BRIEF DESCRIPTION OF DRAWINGS
[0031] FIG. 1 is a schematic showing a surface treatment apparatus
(an anodization treatment apparatus),
[0032] FIG. 2 is a plane view of a second electrode section as
viewed along a line II-II in FIG. 1,
[0033] FIG. 3 (a) is section view showing a fixing arrangement of a
negative electrode member, (b) is a side view taken along a line
IIIb-IIIb in (a),
[0034] FIG. 4 is a section view showing an electrolysis solution
feeding nozzle portion of the second electrode section,
[0035] FIG. 5 is a side view showing an inner circumferential side
of the second electrode section,
[0036] FIG. 6 is a section view showing a condition when an elastic
seal member of the second electrode section is spaced apart from an
outer circumferential face of a piston,
[0037] FIG. 7 is a section view showing a condition when the
elastic seal member of the second electrode section is pressed
against the outer circumferential face of the piston, and
[0038] FIG. 8 is a side view showing a negative electrode member of
a surface treatment apparatus (an anodization treatment apparatus)
according to a second embodiment.
MODES OF EMBODYING THE INVENTION
[0039] Next, embodiments of the present invention will be described
with reference to the accompanying drawings.
First Embodiment
[0040] FIGS. 1 through 7 show an anodization treatment apparatus as
an example of a surface treatment apparatus according to the
present invention. This anodization treatment apparatus is
configured to effect an anodization treatment for forming an
alumite coating on a surface of a piston ring groove A1 of a piston
A made of an aluminum alloy, as an example of a treatment-object
article made of metal.
[0041] More particularly, of three piston ring grooves A1, A2, A3
formed from the top to the skirt portion of the cylindrical piston
A, an anodization treatment is effected on an outer circumferential
face ("piston outer circumferential face" hereinafter) B of the top
side piston ring (compression ring) groove A1.
[0042] Hence, the piston ring groove A1 corresponds to "a
circumferential groove" as "an annular treatment-object area"
included in the piston outer circumferential face B.
[0043] The anodization treatment apparatus includes, as shown in
FIG. 1, an electrolysis solution tank 1, an electrolysis solution
feeding section 2, an oxidization treatment section 3 and an
electric conduction section 4.
[0044] The electrolysis solution tank 1 is made of vinyl chloride
or stainless steel and provided in the form of a top end open
vessel. And, the tank 1 is configured to receive and collect
therein an amount of electrolysis solution that has passed the
oxidization treatment section 3 and includes a reflux path 5 for
refluxing the solution to the electrolysis solution feeding section
2.
[0045] The electrolysis solution feeding section 2 includes a
cooling tank 6 for cooling the electrolysis solution refluxed from
the electrolysis solution tank 1, a feeding path 7 for feeding an
amount of electrolysis solution in the cooling tank 6 to the
oxidization treatment section 3, a feeding pump 8 incorporated in
the feeding path 7, and a feeding control section 9 for controlling
the operation of the feeding pump 8 so that an amount of the
electrolysis solution may be fed to the oxidization treatment
section 3 at a predetermined timing.
[0046] The cooling tank 6 includes a cooler 10 for cooling the
collected electrolysis solution, and a cooling control section 12
for controlling the operation of the cooler 10 based on detection
information of the electrolysis solution temperature obtained by a
temperature sensor 11 so that the electrolysis solution may be
cooled to a predetermined temperature.
[0047] The electric conduction section 4 is provided for conducting
electricity to the oxidization treatment section 3. Preferably,
this electric conduction section 4 is provided with a current
controlling means so as to be capable of adjusting the electric
current density. As such current controlling means, a device
comprised of an ammeter, a voltmeter, a rectifier, or the like
known in the art can be suitably employed.
[0048] The oxidization treatment section 3 includes a first
electrode (positive electrode) section 13 and a second electrode
(negative electrode) section 14.
[0049] The first electrode section 13 includes a positive electrode
member 15 made of metal such as copper, stainless steel, etc.
having conductivity and a lift device 16 for lifting up/down the
positive electrode member 15 relative to the second electrode
section 14.
[0050] The positive electrode member 15 functions also as a
"holder" for holding the piston A, so that the positive electrode
member 15 is electrically connected to a positive electrode
terminal 4a of the electric conduction section 4, thus being
electrically connected to the piston 4 by holding this piston
4.
[0051] The holder (positive electrode member) 15 includes, at the
lower end thereof, a retention pawl (not shown)
engageable/disengageable with/from the inner circumferential face
of the piston A. As this engaging pawl is retained to the inner
circumferential face of the piston A, the holder 15 holds the
piston A under a condition of its axis being aligned along the
perpendicular direction and electrically connected.
[0052] The second electrode section 14, as shown in FIG. 2, has an
outer shape which is circular in its plane view and concentrically
defines a piston insertion hole 25 which is circular in its plane
view for allowing introduction of the piston A with its axis being
aligned along the perpendicular direction.
[0053] The second electrode section 14, as shown in FIGS. 1 through
3, includes a frame member 17 to which a plurality of round-bar
like negative electrode members 41 are affixed, fixing plates 18,
19 disposed upwardly and downwardly of the frame member 17
respectively, and a support base 20, with these components being
bolt-connected to each other. Each negative electrode member 41 is
formed of platinum (Pt) or conductive stainless steel (SUS).
[0054] The number of the negative electrode members 41 to be
provided ranges, preferably, from 4 to 20. In the instant
embodiment, fourteen negative electrode members 41 are disposed in
distribution along the circumferential direction of the frame
member 17.
[0055] The frame member 17, the fixing plates 18, 19 and the
support base 20 are all formed of non-conductive material
(insulating material) such as vinyl chloride resin.
[0056] The frame member 17, as shown in FIG. 1, FIG. 3 and FIG. 4,
is engaged and held between an annular upward concave face portion
21 which is formed by forming upwardly concave a lower face outer
circumferential side of the upper fixing plate 18 and an annular
downward concave face portion 22 which is formed by forming
downwardly concave an upper face outer circumferential side of the
lower fixing plate 19 and bolt-connected thereto, respectively.
[0057] The frame member 17, as shown in FIG. 1, is formed by
bolt-connecting two frame plates, i.e. an upper first frame plate
23 and a lower second frame plate 24. As shown in FIG. 3 and FIG.
5, a negative electrode member 41 is bound and affixed between the
first frame member 23 and the second frame member 24.
[0058] As shown in FIGS. 4 through 6, on the piston insertion hole
25 side of the first frame plate 23 and the second frame plate 24,
there are formed annularly opposed plate portions 27, 28 opposing
the first frame plate 23 and the second frame plate 24 to each
other across a space 26 therebetween and flange plate portions 29,
30 that protrude toward the piston insertion hole 25 side along the
inner circumferential sides of the opposed plate portions 27,
28.
[0059] The inner side of the inner circumferential face of each
flange plate portion 29, 30 ("frame plate inner circumferential
face" hereinafter) is formed as the piston insertion hole 25.
[0060] Therefore, the frame member 17 includes a frame plate inner
circumferential face 31 formed as a "non-conductive annular inner
circumferential face" opposed to the piston outer circumferential
face B and the piston ring groove A1 along the entire
circumferences thereof with a predetermined gap relative thereto
respectively.
[0061] As shown in FIG. 1, the lower fixing plate 19 includes a
round concave face portion 32 which has a same diameter as and is
coaxial with the piston insertion hole 25 and a piston placing
portion 35 on which the top face of the piston A with its axis
aligned along the perpendicular direction is to be placed and
supported.
[0062] Along the lower fixing plate 19 and the support base 20,
there are formed a connecting flow path 33 connected to the feeding
path 7 for the electrolysis solution and a discharge hole 34 for
discharging an amount of electrolysis solution accumulated within
the circular concave face portion 32 to the electrolysis solution
tank 1 by natural (gravity) falling.
[0063] Therefore, as shown in FIG. 1, the piston A held by the
holder (positive electrode member) 15 and electrically connected
under the posture thereof with its axis aligned along the
perpendicular direction is inserted into the piston insertion hole
25 and its top face is placed on the piston placing portion 35.
With this, as shown in FIG. 3 and FIG. 4, the piston A is fixed in
position coaxially with forming a predetermined gap C along the
entire circumferences of the piston outer circumferential face B
and the frame plate inner circumferential face 31.
[0064] On the frame plate inner circumferential face 31 side of the
frame member 17, as shown in FIG. 1 and FIGS. 3 through 7, there
are attached two upper and lower non-conductive annular elastic
seal members 40 which are mounted vertically and non-withdrawably
with a gap therebetween and with leading end portions 44 thereof
not protruding more toward the piston outer circumferential face B
side than the frame plate inner circumferential face 31.
[0065] Each elastic seal member 40 is formed as an annular shaped
non-conductive material (insulating material) such as rubber. As
shown in FIG. 7, its leading end portion 44 is extended to be in
pressed contact against the piston outer circumferential face B, so
that the seal member 40 seals the gap C between the opposed
portions of the piston outer circumferential face B across the
circumferential groove A1 and the frame plate inner circumferential
face 31, thereby forming an annular electrolysis solution path 45
extending along the circumferential groove A1.
[0066] Each elastic seal member 40 defines a concave portion 42
open toward its outer circumference side and continuously along the
entire circumference and has a horizontally oriented U-shaped cross
section including upper and lower lateral wall portions 43 and the
leading end portion 44 which is brought into the pressed contact
against the piston outer circumferential face B.
[0067] As shown in FIG. 1, FIG. 6 and FIG. 7, there is provided a
pressurization mechanism 51 capable of feeding pressurized air as a
pressurized fluid to the outer circumferential sides of the
respective elastic seal members 40 simultaneously, so as to bring
the inner circumferential sides (leading end portions 44) of these
elastic seal member 40 into pressed contact against the piston
outer circumferential face B along the entire circumference and
capable also of releasing the pressed contacts when needed.
[0068] The pressurization mechanism 51 includes an air
feeding/discharging device 52 capable of feeding and discharging of
pressurized air, a feeding/discharging control section 53 for
controlling air feeding/discharging operations of the air
feeding/discharging device 52, air feeding/discharging paths 54
communicated to the respective concave portions 42 of the elastic
seal members 40 and a pipe joint 56 for joining an air
feeding/discharging pipe 55 of the air feeding/discharging device
52 to the air feeding/discharging path 54.
[0069] The air feeding/discharging paths 54 are provided at three
circumferential portions of the second electrode section 14, and to
each air feeding/discharging path 54, the air feeding/discharging
pipe 55 is connected, so that for the concave portion 42 of each
elastic seal member 40, pressurized air can be fed/discharged
to/from the three circumferential positions.
[0070] Next, the operations of the pressurization mechanism 51 will
be explained.
[0071] As shown in FIG. 6, when the piston A is inserted into the
piston insertion hole 25 and placed on the piston placing portion
35, the feeding/discharging control section 53 activates the air
feeding/discharging device 52 so as to feed an amount of
pressurized air to each concave portion 42 of each elastic seal
member 40 through the air feeding/discharging path 54.
[0072] Upon feeding of the pressurized air into the concave portion
42 of the elastic seal member 40, this elastic seal member 40 is
elastically extended toward the piston outer circumferential face B
and also the leading end portion 44 is elastically bulged and
displaced toward the piston outer circumferential face B, whereby
this leading end portion 44 is pressed against the piston outer
circumferential face B, as shown in FIG. 7.
[0073] Upon establishment of this pressed contact of the leading
end portion 44 of the elastic seal member 40 against the piston
outer circumferential face B as shown in FIG. 7, on each of the
lateral sides across the circumferential groove A1, the gap C
between the piston outer circumferential face B and the frame plate
inner circumferential face 31 is sealed and the annular
electrolysis solution path 45 along the circumferential groove A1
is formed.
[0074] As shown in FIG. 2, FIG. 3 and FIG. 5, each one of the
negative electrode members 41 is formed as a straight bar-like
member including an electrode shaft portion 46 having a leading end
portion 46a protruding toward the piston A into the electrolysis
solution path 45, a fixing shaft portion 47 to be fixed to the
frame member 17, and a connecting shaft portion 48 to be
electrically connected to a negative electrode terminal 4b of the
electric conduction section 4.
[0075] The leading end portion 46a of the electrode shaft portion
46 is formed as a convex curved shape having no corners.
[0076] Preferably, the plurality of negative electrode members 41
are disposed such that the longitudinal directions (axial
directions) thereof be same as the direction perpendicular to the
piston outer circumferential face B or be inclined within an angle
range of 75 degrees relative to the perpendicular direction.
[0077] In the instant embodiment, as shown in FIG. 2, the plurality
of negative electrode members 41 are arranged radially centrally
about the piston insertion hole 25 with the longitudinal directions
of the electrode shaft portions 46 thereof being oriented
perpendicular relative to the piston outer circumferential face B
and disposed in distribution equidistantly along the
circumferential direction of the electrolysis solution path 45.
[0078] In each negative electrode member 41, the fixing shaft
portion 47 is clamped and fixed between the first frame plate 23
and the second frame plate 24, such that the electrode shaft
portion 46 protrudes toward the piston A in an electrolysis
solution discharge path 38 to be described later as shown in FIG. 3
and FIG. 5 and the connecting shaft portion 48 protrudes toward the
outer circumferential side of the frame member 17.
[0079] The connecting shaft portion 48 of each negative electrode
member 41, as shown in FIG. 2, is electrically connected to a
common connecting terminal plate 49 electrically connected to the
negative electrode terminal 4b of the electric conduction section
4.
[0080] The connecting terminal plate 49 is formed as a round
annular shape and each connecting shaft portion 48 is electrically
connected thereto, as being clamped between the connecting terminal
plate 49 and a receiving plate 50 bolt-fixed to the connecting
terminal plate 49.
[0081] Therefore, for replacement of the negative electrode member
41, the connection between the connecting shaft portion 48 and the
connecting terminal plate 49 will be released and then the negative
electrode member 41 to be replaced will be withdrawn from between
the first frame plate 23 and the second frame plate 24. Thereafter,
a new negative electrode member 41 will be inserted between the
first frame member 23 and the second frame plate 24 and connected
to the connecting terminal plate 49. In this way, the replacement
can be carried out easily.
[0082] As shown in FIG. 2, FIG. 4 and FIG. 5, between the first
frame plate 23 and the second frame plate 24, more particularly,
between the opposed plate portions 27 and the flange plate portions
29 of the former and the opposed plate portions 28 and the flange
plate portions 30 of the latter, there are provided a plurality of
electrolysis solution feeding nozzles 36 arranged along the
circumferential direction and spaced apart from each other with a
predetermined distance therebetween.
[0083] The electrolysis solution feeding nozzles 36 are preferably
provided in the same number as the number of the negative electrode
members 41. In the instant embodiment, fourteen (14) of them are
provided as the same number as the negative electrode members
41.
[0084] As shown in FIG. 4 and FIG. 5, each electrolysis solution
feeding nozzle 36 is connected to a connecting path 33 and includes
a feeding path 37 for feeding electrolysis solution to the
electrolysis solution path 45 and this feeding path 37 is open in
the frame plate inner circumferential face 31.
[0085] Preferably, the electrolysis solution feeding nozzle 36, as
shown in FIG. 2, is provided such that the path axis X of its
feeding path 37 is inclined by an angle within an angle range from
5 to 75 degrees relative to a tangent to the frame plate inner
circumferential face 31.
[0086] As shown in FIG. 1 and FIG. 5, the electrolysis solution
feeding nozzles 36 adjacent to each other along the circumferential
direction delimit a space 26 between the upper and lower opposing
plate portions 27, 28 as well as a space between the upper and
lower flange portion 29, 30 thereof respectively. These spaces
together from the electrolysis solution discharge path 38 mentioned
above.
[0087] Each electrolysis solution feeding nozzle 36 is disposed so
as to be capable of feeding the electrolysis solution to the
electrolysis solution path 45 along a direction inclined relative
to the tangent of the frame plate inner circumferential face 31
such that the electrolysis solution may flow along the electrolysis
solution path 45.
[0088] Therefore, as the electrolysis solution feeding section 2
having these electrolysis solution feeding nozzles 36 is provided
as an "electrolysis solution circulating means" for circulating an
amount of electrolysis solution along the electrolysis solution
path 45. Hence, as the electrolysis solution is caused to circulate
around the surface of the electrode shaft portion 46 as indicated
by the arrow (a) in FIG. 5, any deposited metal with a weak
adhering strength accumulated on the electrode shaft portion 46 may
be readily removed by the impetus of the gushed electrolysis
solution.
[0089] Since the deposited metal accumulated on the electrode shaft
portion 46 can be readily removed, there will hardly occur spark
due to contact between the accumulated deposited metal and the
piston outer circumferential face B or the circumferential groove
A1. Hence, the possibility of melting of formed alumite coating by
sparking and resultant deterioration in the treatment quality is
lessened.
[0090] As shown in FIG. 2, between circumferentially adjacent
electrolysis solution feeding nozzles 36, there is formed a through
hole 39 extending through the lower opposed plate portion 28, the
lower fixing plate 19 and the support base 20, so that the
electrolysis solution of the discharge path 38 will flow down
naturally through these through holes 39 to be discharged into the
electrolysis solution tank 1.
[0091] With the anodization treatment apparatus according to the
instant embodiment, deposited metal accumulated on the negative
electrode member 41 will hardly grow. Hence, the electrode use
period until the deposition thickness of deposited metal increases
to a thickness requiring replacement of the negative electrode
member 41 has become approximately twice as large as that of the
conventional anodization treatment apparatus having a negative
electrode member having an annular circumferential face opposed
with a gap to the outer circumferential face B and the
circumferential groove A1 of the piston A.
[0092] Further, as shown in Table 1 below, in the case of forming
an alumite coating having a coating thickness of 15 .mu.m, in
comparison with the conventional anodization treatment apparatus
disclosed in Patent Document 1, it was found that the burning
voltage becomes 50V or more higher, and by setting the voltage by
30V or more, it became possible to reduce the treatment period by
30% or more.
TABLE-US-00001 TABLE 1 target burning coating set treatment voltage
thickness voltage period prior art 80 V 15 .mu.m 60 V 30 sec
invention 130 V 15 .mu.m 90 V 20 sec comparison 50 V equivalent 30
V 30% higher higher improved
Second Embodiment
[0093] FIG. 8 shows a negative electrode member 41 in a further
embodiment of the surface treatment apparatus (an anodization
treatment apparatus) relating to the present invention.
[0094] In the instant embodiment, for providing the electrode shaft
portion 46 with a greater surface area, in its outer
circumferential face, there is formed a concave/convex face 57
having convex faces and concave faces alternately along the axial
direction. The convex faces and the concave faces are formed
spirally along the axis of the electrode shaft portion 46.
Other Embodiments
[0095] 1. The surface treatment apparatus according to the present
invention may be configured to effect surface treatment on a convex
(ridge-like) or planar annular treatment-object area included in
the outer circumferential face of the treatment-object article.
[0096] 2. The surface treatment apparatus according to the present
invention may include a negative electrode member electrically
connected to a metal treatment-object article and a bar-like
positive electrode member having a leading end portion protruding
toward the treatment-object article into the electrolysis solution
path.
[0097] 3. The surface treatment apparatus according to the present
invention may include the other one of the positive electrode
member and the negative electrode member which is in the form of a
bar having an oval or polygonal cross sectional shape.
[0098] 4. The surface treatment apparatus according to the present
invention may include a single other one of the positive electrode
member and the negative electrode member in the form of a bar.
[0099] 5. In the surface treatment apparatus according to the
present invention, the other one of the positive electrode member
and the negative electrode member having the bar-like shape may
protrude with its longitudinal direction being an oblique direction
relative to the outer circumferential face of the treatment-object
article.
[0100] 6. In the surface treatment apparatus according to the
present invention, the other one of the positive electrode member
and the negative electrode member having the bar-like shape may
protrude with its longitudinal direction being an oblique direction
toward the upstream side in the flow direction of the electrolysis
solution in the electrolysis solution path or being an oblique
direction toward the downstream side in the flow direction of the
electrolysis solution in the electrolysis solution path.
[0101] 7. The surface treatment apparatus according to the present
invention may be an electroplating treatment apparatus for
effecting electroplating treatment as a surface treatment.
DESCRIPTION OF REFERENCE NUMERALS/MARKS
[0102] 2 electrolysis solution circulating means [0103] 15 one of
positive electrode member and negative electrode member (positive
electrode member) [0104] 17 frame member [0105] 31 non-conductive
inner circumferential plate [0106] 40 elastic seal member [0107] 41
the other one of positive electrode member and negative electrode
member (negative electrode member) having a bar-like shape [0108]
45 electrolysis solution path [0109] 46a leading end portion [0110]
57 convex/concave face [0111] A treatment-object article [0112] A1
annular treatment-object area (circumferential groove) [0113] B
outer circumferential face [0114] C gap
* * * * *