U.S. patent application number 11/783744 was filed with the patent office on 2007-10-25 for barrel plating device.
Invention is credited to Yoshiaki Hoshino, Tokiko Katsumoto, Wataru Yamamoto.
Application Number | 20070246349 11/783744 |
Document ID | / |
Family ID | 38618450 |
Filed Date | 2007-10-25 |
United States Patent
Application |
20070246349 |
Kind Code |
A1 |
Yamamoto; Wataru ; et
al. |
October 25, 2007 |
Barrel plating device
Abstract
A barrel plating device includes a cylindrical drum which is
immersed in a plating solution in a horizontal state and configured
for containing objects to be plated; a support member for rotatably
supporting the drum; a drive mechanism for rotatably drive the
drum; and a conductive member in a shape of bar which is disposed
coaxially with the drum and integrally rotate with the drum.
Inventors: |
Yamamoto; Wataru; (Tokyo,
JP) ; Katsumoto; Tokiko; (Tokyo, JP) ;
Hoshino; Yoshiaki; (Saitama, JP) |
Correspondence
Address: |
BERENATO, WHITE & STAVISH;Suite 240
6550 Rock Spring Drive
Bethesda
MD
20817
US
|
Family ID: |
38618450 |
Appl. No.: |
11/783744 |
Filed: |
April 11, 2007 |
Current U.S.
Class: |
204/212 |
Current CPC
Class: |
C25D 17/20 20130101 |
Class at
Publication: |
204/212 |
International
Class: |
C25D 17/00 20060101
C25D017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2006 |
JP |
2006-120392 |
Claims
1. A barrel plating device comprising: a cylindrical drum for
containing objects to be plated and being immersed in a plating
solution in a horizontal state; a support member for rotatably
supporting the drum; a drive mechanism for rotatably driving the
drum; and a conductive member in a shape of a bar which is disposed
coaxially with the drum and integrally rotates with the drum.
2. The barrel plating device according to claim 1, further
comprising an electrode shielding part comprising: an electrode
electrically connected to the conductive member; a housing for
holding the electrode, in which an end part of the conductive
member is inserted; and a liquid-proof part for preventing the
plating solution from entering the housing.
3. The barrel plating device according to claim 2, wherein the
electrode comprises: an electrode bar; a conductor electrically
connected to the conductive member; and an elastic member for
connecting the electrode bar with the conductor, and biases the
conductor to the conductive member.
4. The barrel plating device according to claim 1, wherein the drum
is removably attached to the support member.
5. The barrel plating device according to claim 1, wherein the drum
has tapered portions formed in internal faces thereof.
6. The barrel plating device according to claim 1, wherein the drum
has lid parts on both ends, and at least a part of an inner face of
the lid part exposed to an internal space of the drum has a
plurality of grooves formed thereon.
7. The barrel plating device according to claim 1, wherein the drum
has rotational shafts on both ends, the shaft being rotatably
supported by fixing means provided on the support member.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the foreign priority benefit under
Title 35, United States Code, section 119 (a)-(d), of Japanese
Patent Application No. 2006-120392, filed on Apr. 25, 2006 in the
Japan Patent Office, the disclosure of which is herein incorporated
by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a barrel plating device
suitable for plating small objects.
[0004] 2. Description of the Related Art
[0005] As for a barrel plating device for plating small objects,
there has been known a device having: a horizontally and rotatably
supported drum for holding objects to be plated therein; a plating
bath for storing a plating solution in which the drum is immersed;
a negative electrode which is held in the drum together with the
objects to be plated; and a positive electrode disposed in the
plating solution in the plating bath in such a manner that a
periphery of the drum is arranged between two electrodes (see, for
example, Japanese unexamined patent application laid-open
specification Kokai No. 10-102297, paragraph 0002 and FIG. 5).
[0006] For such a plating device, as shown in FIGS. 9 and 10, there
can be mentioned a barrel plating device 101 having: a drum 102 in
a shape of a polygonal cylinder which is horizontally and rotatably
supported by a support member 106 and has side walls 123 each with
a liquid passing part 124a; and a center bar 103 which does not
rotate and is coaxially arranged with the drum 102.
[0007] For performing plating using the barrel plating device 101,
first, objects P to be plated are put in the drum 102. The drum
102, together with the support member 106, is immersed in a plating
bath 111, and energized state is made between a positive electrode
(not shown) and the center bar 103 as a negative electrode, while
the drum 102 is rotated by a motor 150 disposed at an upper part of
the support member 106, through gears 151, 152, 153 and 128.
[0008] However with the plating device 101, when the drum 102 is
rotated, a gap V is formed between the center bar 103 and the
objects P to be plated and a high-current-density part C is
generated as shown in FIG. 10, since the center bar 103 does not
rotate. As a result, there arises a problem that burnt deposit may
be occurred in a plating film formed on a surface of each of plated
objects P facing the high-current-density part C.
[0009] In addition, with the above-mentioned plating device 101,
removal (and thus replacement) of the drum 102 is not easy, since
the center bar 103 penetrates through the drum 102, as shown in
FIG. 2. Due to this structure, in order to put and remove the
objects P to be plated, a face or a part thereof of the side wall
123 of the drum 102, for example, is made attachable and removable
(not shown), leading to poor workability.
[0010] Therefore, it would be desirable to provide a barrel plating
device in which a gap is not formed between a bar-shaped conductive
member and objects to be plated in a drum, which gap may otherwise
generate a high-current-density part, to thereby prevent an
occurrence of burnt deposit in a plating film formed on a surface
of the plated object.
[0011] It would be further desirable to provide a barrel plating
device in which a replacement of a drum and introduction and
removal of objects are facilitated to thereby improve workability,
and at the same time, the drum is stably rotated without coming off
of a use position during an operation of the plating device.
SUMMARY OF THE INVENTION
[0012] In one aspect of the present invention, there is provided a
barrel plating device including: a cylindrical drum for containing
objects to be plated and being immersed in a plating solution in a
horizontal state; a support member for rotatably supporting the
drum; a drive mechanism for rotatably driving the drum; and a
conductive member in a shape of a bar which is disposed coaxially
with the drum and integrally rotates with the drum.
[0013] With this configuration, the drum and the bar-shaped
conductive member integrally rotate. Therefore, a gap is not formed
between the bar-shaped conductive member and the objects to be
plated in the drum, which prevents a generation of a
high-current-density part. As a result, there is prevented an
occurrence of burnt deposit in a plating film formed on a surface
of the plated object.
[0014] The barrel plating device may preferably but not necessarily
further include an electrode shielding part including: an electrode
electrically connected to the conductive member; a housing for
holding the electrode, in which an end part of the conductive
member is inserted; and a liquid-proof part for preventing the
plating solution from entering the housing.
[0015] With this configuration, the plating solution is prevented
from entering the housing, even though the drum (or the conductive
member) is rotating. Therefore, an electrically connected part
between the conductive member and the electrode is prevented from
being brought into contact with the plating solution. As a result,
defective rotation of the drum, which may be caused due to a
formation of plating film on the above-mentioned electrically
connected part, can be prevented.
[0016] Since a plating film is not formed on the above-mentioned
electrically connected part or the electrode, the plating solution
is not wasted, and at the same time, the conductive member and the
electrode can be repeatedly used, leading to excellent cost
performance.
[0017] The electrode may preferably but not necessarily include an
electrode bar; a conductor electrically connected to the conductive
member; and an elastic member for connecting the electrode bar with
the conductor, and biases the conductor to the conductive
member.
[0018] Since the conductor is biased to the conductive member by
the elastic member, the conductive member can be energized while
the drum is properly rotating.
[0019] Since the electrode is formed of components including the
electrode bar, the conductor and the elastic member, the most
suitable material for each component can be independently selected
for carrying out their respective functions.
[0020] The drum may preferably but not necessarily be removably
attached to the support member.
[0021] Since the drum can be easily removed, a replacement of the
drum and introduction and removal of objects are facilitated to
thereby improve workability.
[0022] The drum may preferably but not necessarily have tapered
portions formed in internal faces thereof.
[0023] With this configuration, the drum has less acute corners
inside thereof, as compared with the conventional drums without
tapered portions. Therefore, scratches on the surface of the plated
objects that may otherwise be caused by contact or collision with
the corners can be reduced.
[0024] Due to the tapered portions, the inner face of the drum
becomes smooth and therefore, the objects to be plated are not
caught by the inner face of the drum. As a result, formation of a
plating film on the surface of the objects becomes excellent and
quality is improved, and at the same time, the plated objects can
be easily removed, to thereby improve workability.
[0025] The drum may preferably but not necessarily have lid parts
on both ends, and at least a part of an inner face of the lid part
exposed to an internal space of the drum has a plurality of grooves
formed thereon.
[0026] Since the drum has grooves on an inner face of the lid part,
the plated objects are not easily attached to the inner face of the
lid part, as compared with the conventional lid parts without
grooves. As a result, formation of a plating film on the surface of
the objects becomes excellent and quality is improved, and at the
same time, the plated objects can be easily removed, to thereby
improve workability.
[0027] The drum may preferably but not necessarily have rotational
shafts on both ends, the shaft being rotatably supported by fixing
means provided on the support member.
[0028] With this configuration, the rotational shaft is prevented
from coming off of the support member during the operation of the
barrel plating device. As a result, the drum is stably rotated
without coming off of a use position during the operation of the
plating device (during a rotation of the drum).
[0029] According to the present invention, there is provided a
barrel plating device in which an occurrence of burnt deposit in
the plating film formed on the surface of the plated objects is
prevented, by preventing a formation of a gap between the
bar-shaped conductive member and the objects in the drum, which may
otherwise generate a high-current-density part.
[0030] In addition, according to the present invention, there is
provided a barrel plating device in which a replacement of the drum
and introduction and removal of the objects are facilitated to
thereby workability, and at the same time, the drum is stably
rotated without coming off of a use position during the operation
of the plating device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The various aspects, other advantages and further features
of the present invention will become more apparent by describing in
detail illustrative, non-limiting embodiments thereof with
reference to the accompanying drawings.
[0032] FIG. 1 is a perspective view of a configuration diagram of a
barrel plating device according to one embodiment of the present
invention.
[0033] FIG. 2 is an elevational view of a configuration diagram of
a barrel plating device according to one embodiment of the present
invention.
[0034] FIG. 3 is an exploded perspective view of a drum of a barrel
plating device according to one embodiment of the present
invention.
[0035] FIG. 4 illustrates tapered portions formed in a drum of a
barrel plating device according to one embodiment of the present
invention. FIG. 4A is a sectional view of the drum taken along a
line X-X in FIG. 3. FIG. 4B is a sectional view of the drum taken
along a line Y-Y in FIG. 3.
[0036] FIG. 5 is a partial cross sectional view of the barrel
plating device illustrating configurations of a drum, a center bar
and an electrode shielding part.
[0037] FIG. 6 is an exploded perspective view of an electrode
shielding part of a barrel plating device according to one
embodiment of the present invention.
[0038] FIGS. 7A-C are partial perspective views illustrating
methods for attaching and fixing a support member to a drum of a
barrel plating device according to one embodiment of the present
invention.
[0039] FIG. 8 is a view showing a state of an inside of a drum
during an operation of a barrel plating device according to one
embodiment of the present invention.
[0040] FIG. 9 is an elevational view showing a configuration of a
conventional barrel plating device.
[0041] FIG. 10 is a view showing a state of an inside of a drum
during an operation of a conventional barrel plating device.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0042] Embodiments of the present invention will be described in
detail below with reference to the drawings.
(Barrel Plating Device 1)
[0043] A barrel plating device 1 according to the present invention
is a device for plating small objects, such as small parts, and as
shown in FIGS. 1 and 2, is mainly formed of: a drum 2 configured
for holding objects to be plated therein; a center bar 3 arranged
in the drum 2 coaxially with the drum 2 (see FIG. 2); an electrode
shielding part 4 configured for protecting an electrically
connected part between a shaft bar 26B and an electrode 41 from a
plating solution, to which shaft bar 26B the center bar 3 is
connected; a driving mechanism 5 configured for rotatably driving
the drum 2 about a center of an axle thereof; and a support member
6 configured for rotatably supporting the drum 2.
[0044] Also referring to FIG. 8, when the barrel plating device 1
is operated, it is immersed in a plating solution L contained in a
plating bath 11 in which a positive electrode (not shown) is
disposed. The drum 2 is rotatably supported by a lower part of the
support member 6. One end (i.e. a gear 28) of the drum 2 is
connected to the drive mechanism 5, and a rotation of a motor 50
disposed at an upper part of the support member 6 is transmitted to
the drum 2 through the drive mechanism 5 (including gears 51-53).
The other end (i.e. the shaft bar 26B) of the drum 2 is inserted in
(a liquid-proof part 43 of) the electrode shielding part 4
configured for holding the electrode 41 to be connected to a
negative pole of a power supply (not shown), and is electrically
connected to the electrode 41. In the drum 2, the center bar 3 is
disposed (see FIG. 2), and objects P to be plated are
introduced.
[0045] Each component of the barrel plating device 1 will be
described in detail below.
(Drum 2)
[0046] The drum 2 is a cylindrical container configured for holding
objects to be plated. In this embodiment, the drum 2 is mainly
formed of: a drum body 20 including side walls 23 made of acrylic
resin arranged as a hexagonal cylinder and end parts 22,22 at both
ends of the side walls 23; and drum lids 21A,21B each removably
attached to the respective end parts 22,22. The drum 2 is rotatably
supported by the lower part of the support member 6 (see FIGS. 1
and 2).
[0047] Though in the present invention, the drum body 20 is (or the
side walls 23 are arranged) in a shape of a hexagonal cylinder, the
shape may be other polygonal cylinder, such as an octagonal
cylinder, or a circular cylinder.
[0048] In the end part 22 of the drum body 20, a sample inlet 22a
in a shape of a circle is formed. The sample inlet 22a is used
before and after plating, i.e., for putting the objects P to be
plated in the drum 2, and for removing plated objects P from the
drum 2. Examples of the objects P to be plated include: electronic
parts, such as IC chip, resistor and condenser; minute machine
parts made of ceramic, glass fiber, resin or the like; and fine
powder.
[0049] Though in the present embodiment, the sample inlet 22a is in
a shape of a circle, it may be in a shape of a polygon. There is no
limitation with respect to a size (or an opening diameter) of the
sample inlet 22a.
[0050] In the side wall 23 of the drum body 20, at least one side
wall opening 23a is formed, and a perforated lid 24 made of acrylic
resin having at least one liquid passing part 24a that allows the
plating solution L to pass is removably attached to the side wall
23 with screws 24b made of polyether ether ketone (PEEK), in such a
manner that the liquid passing part 24a covers the side wall
opening 23a.
[0051] The liquid passing part 24a may be in a form of a mesh, a
set of slits or a set of pores, or combinations thereof. There is
no limitation with respect to a size of the liquid passing part
24a, i.e., a size of the mesh, a width of the slit or a diameter of
the pore or the like, as long as the liquid passing part 24a allows
the plating solution L to pass through and holds the objects P to
be plated in the drum 2. In the present embodiment, the liquid
passing part 24a is in a form of a mesh.
[0052] Since the perforated lid 24 is exchangeable with other
perforated lid 24 having the liquid passing part 24a with a mesh
(or the like) of different size, the same drum 2 is applicable to
objects to be plated (such as small parts) having different size.
Therefore, as compared with the conventional drum 102 (see FIG. 9)
having the liquid passing part 124a directly formed in the side
wall 123, workability is enhanced in the drum 2 of the present
embodiment, and thus the drum 2 of the present invention is
cost-effective.
[0053] The drum lid 21A is mainly formed of: a lid part 25A made of
acrylic resin removably attached to the end part 22 of the drum
body 20; a shaft bar 26A made of Teflon.TM. connected to the lid
part 25A and served as a rotational shaft of the drum 2; a slide
shaft bearing 27A made of Teflon.TM. and supported by the support
member 6 which will be explained below, in which slide shaft
bearing the shaft bar 26A is inserted; and the gear 28 made of
polymethylpentene (TPX).TM. with which the shaft bar 26A is
connected and the drive mechanism 5 is coupled (see FIG. 2). It
should be noted that the shaft bar 26A may be made of resin other
than Teflon.TM., or may be made of stainless steel coated with
insulation film, such as Teflon.TM. coating.
[0054] The drum lid 21B is mainly formed of: a lid part 25B made of
acrylic resin removably attached to the end part 22 of the drum
body 20; a shaft bar 26B made of stainless steel connected to the
center bar 3 and served as a rotational shaft of the drum 2; and a
slide shaft bearing 27B made of Teflon.TM. and supported by the
support member 6 which will be explained below, in which slide
shaft bearing the shaft bar 26B is inserted. In an end of the shaft
bar 26B on an inner side of the drum 2, a fitting hole 29 for
fitting the center bar 3, which will be described below, is formed.
A portion of the shaft bar 26B which is to be brought into direct
contact with the plating solution L is covered with an insulation
film, such as Teflon.TM. coating (not shown).
[0055] The center bar 3 which will be described below and the shaft
bar 26B in the present embodiment correspond to "conductive
member".
[0056] On an inner face of the lid part 25B, a plurality of grooves
G is formed, each of which is smaller than a size of the object P
to be plated. With this configuration, as compared with the lid
part without grooves, objects P to be plated does not tend to
attach to the inner face of the lid part 25B, and thus a formation
of the plating film on the surface of the objects becomes
excellent, leading to improvement of quality. At the same time,
removal of the plated objects P is facilitated to thereby improve
workability.
[0057] Though in the present embodiment, the grooves G are arranged
as concentric circles with the center bar 3 (or the shaft bar 26B)
as a center, there is no limitation with respect to the arrangement
of the grooves G, as long as a plurality of the grooves G each
smaller than the objects P to be plated is formed. For example, the
arrangement of the grooves G may be in a shape of diamond cut (or
pineapple cut) or grid. In addition, there is no limitation with
respect to a cross sectional shape of the groove G, and the cross
section may be, for example, in a V-shape. With respect to an area
(or range) of the inner face of the lid part 25B in which the
grooves G are formed, there is no limitation as long as the area is
large enough to cover the sample inlet 22a when the lid part 25B is
attached to the drum body 20. In other words, the grooves G are
formed in at least a part of an inner face of the lid part 25B
exposed to an internal space of the drum 2 when the lid part 25B is
attached to the drum body 20.
[0058] Likewise, the lid part 25A also has the grooves G (not
shown).
[0059] As shown in FIG. 4A, in the drum 2, a tapered portion Ti is
formed from the side walls 23 to the sample inlet 22a. As shown in
FIGS. 4A and 4B, a tapered portion T2 is formed on a circumference
of the side wall opening 23a, from inside to outside. With this
configuration, the drum 2 has less acute corners inside thereof, as
compared with the conventional drums without tapered portions.
Therefore, scratches on the surface of the plated objects P that
may otherwise be caused by contact or collision with the corners
can be reduced. In addition, due to the tapered portions T1,T2, the
inner face of the drum 2 becomes smooth and therefore, the objects
P to be plated are not caught by the inner face of the drum 2. As a
result, formation of a plating film on the surface of the objects
becomes excellent and quality is improved, and at the same time,
the plated objects P can be easily removed, to thereby improve
workability.
(Center Bar 3)
[0060] The center bar 3 is a member made of, for example, brass or
copper, which serves as a negative electrode of the barrel plating
device 1. As shown in FIG. 3, the center bar 3 is mainly formed of:
an electrode part 31 to be disposed in the drum 2; and a fitting
part 32 for removably attaching the center bar 3 to the fitting
hole 29 of the shaft bar 26B. At least the electrode part 31 is
disposed inside the drum 2, and arranged coaxially with the drum
2.
[0061] A male thread part (thread ridge) is provided on the fitting
part 32 and a female thread part is provided in the fitting hole 29
formed in the end of the shaft bar 26B on the inner side of the
drum 2. By engaging the male thread part with the female thread
part as shown in FIG. 5, the center bar 3 and the shaft bar 26B are
connected.
[0062] Optionally, the connection of the center bar 3 and the shaft
bar 26B is reinforced by pressingly fastening from a lateral side
of the fitting part 32 with a center-bar-fixing screw 29a made of
PEEK resin.
[0063] By connecting the center bar 3 and the drum 2 (shaft bar
26B) as a single piece in a manner described above, the drum 2 and
the center bar 3 can integrally rotate. Therefore, a gap is not
formed between the center bar 3 and the objects P to be plated in
the drum, which prevents a generation of a high-current-density
part. As a result, there is prevented an occurrence of burnt
deposit in a plating film formed on a surface of the plated
object.
[0064] Since the center bar 3 and the drum 2 (shaft bar 26B) are
removably attached, replacement of the center bar 3 is facilitated,
not only when an unserviceable center bar 3 is replaced with a new
one, but also when a center bar 3 is replaced with a center bar 3
made of a material compatible with a material of the objects P to
be plated or a composition of the plating solution L. Therefore,
the same drum 2 can be used for different objects to be plated or
plating solutions, regardless of the material of the objects, or
the composition of the plating solution, which contribute to
excellent cost performance.
(Electrode Shielding Part 4)
[0065] The electrode shielding part 4 is configured for protecting
an electrically connected part to between the shaft bar 26B to
which the center bar 3 is connected and the electrode 41, from the
plating solution L. As shown in FIGS. 5 and 6, the electrode
shielding part 4 is mainly formed of: the electrode 41 electrically
connected to the center bar 3 through the shaft bar 26B; a housing
42 configured for holding the electrode 41 and the shaft bar 26B
inserted therein; and the liquid-proof part 43 for preventing the
plating solution L from entering the housing 42. The electrode
shielding part 4 is attached to a side face (on a shaft bar
26B-side) of the support member 6 (see FIGS. 1 and 2).
[0066] The electrode 41 is mainly formed of: an electrode bar 41a;
a conductor 41b electrically connected to the shaft bar 26B; and a
conductive elastic member 41c electrically connecting the electrode
bar 41a with the conductor 41b and biasing the conductor 41b to the
shaft bar 26B.
[0067] The electrode bar 41a is made of, for example, brass or
copper, and electrically connected to a negative pole of the power
supply, which energizes the center bar 3 through the elastic member
41c, the conductor 41b and the shaft bar 26B.
[0068] The conductor 41b is electrically connected to the shaft bar
26B, and energized while slidably moving. Examples of the conductor
41b include carbon brush. Carbon brush, which is a block-shaped
mass mainly formed of graphite, is suitable for a member
electrically connected and energized while slidably moving, since
it hardly rusts but is still highly conductive like metal, and
slippery with low friction.
[0069] The elastic member 41c is, for example, a conductive coil
spring, which connects the electrode bar 41a with the conductor
41b, and biases the conductor 41b to the shaft bar 26B to such a
degree that the rotation of the shaft bar 26B (or the drum 2) is
not hindered.
[0070] It should be noted that, the electrode bar 41a may be
directly (and electrically) connected to the shaft bar 26B and
energized while slidably moving, as long as the rotation of the
shaft bar 26B (or the drum 2) is not hindered.
[0071] Referring to FIG. 6, the housing 42 is made of acrylic
resin, which is mainly formed of: an electrode insertion hole 42a
into which the electrode 41 is inserted from an upper end thereof;
a mounting recess 42b formed in one side face of a lower portion of
the housing 42, to which the liquid-proof part 43 (which will be
described below) is attached; and a shaft bar-insertion hole 42c
formed in the mounting recess 42b, into which the shaft bar 26B is
inserted. The housing 42 is attached to the support member 6 with
mounting members 44,45.
[0072] As shown in FIG. 6, the liquid-proof part 43 is mainly
formed of: a liquid-proof sealing 43a for preventing the plating
solution L from entering the housing 42; a fixing plate 43b made of
acrylic resin, in which a through-hole 43c for an insertion of the
shaft bar 26B is formed; and screws 43d made of PEEK resin, for
fixing the fixing plate 43b to the mounting recess 42b of the
housing 42.
[0073] When the liquid-proof part 43 is mounted on the housing 42,
the through-hole 43c of the fixing plate 43b, the liquid-proof
sealing 43a and the shaft bar-insertion hole 42c are
communicatively aligned in line. When the shaft bar 26B is
inserted, the plating solution L is prevented from entering the
housing 42 due to the liquid-proof sealing 43a.
[0074] With this configuration of the electrode shielding part 4,
the plating solution L is prevented from entering the housing 42,
even though the drum 2 (or the shaft bar 26B) is rotating.
Therefore, an electrically connected part between the shaft bar 26B
to which the center bar 3 is connected and the electrode 41 (or the
conductor 41b) is prevented from being brought into contact with
the plating solution L. As a result, defective rotation of the drum
2 (or the shaft bar 26B), which may be caused due to a formation of
plating film on the above-mentioned electrically connected part,
can be prevented.
[0075] Since a plating film is not formed on the above-mentioned
electrically connected part or the electrode 41, the plating
solution L is not wasted, and at the same time, the shaft bar 26B
and the electrode 41 can be repeatedly used, leading to excellent
cost performance.
(Drive Mechanism 5)
[0076] The drive mechanism 5 serves as a power supply and is
configured for transmitting a driving force to rotate the drum 2.
As shown in FIG. 2, the drive mechanism 5 is mainly formed of: the
motor 50 having a driving shaft 50a; the gear 51 made of TPX.TM.
resin, which is attached to a driving shaft 50a; the gear 52 made
of TPX.TM. resin, which engages with the gear 51; and the gear 53
made of TPX.TM. resin, which engages with the gear 52. The motor 50
is disposed at the upper part of the support member 6, and the
gears 51, 52 and 53 are attached to a side face (on a shaft bar
26A-side) of the support member 6.
[0077] With this drive mechanism 5, when the motor 50 is driven, a
rotation of the driving shaft 50a of the motor is transmitted to
the gear 52 through the gear 51 to thereby rotate the gear 52. The
rotation of the gear 52 is then transmitted to the gear 53 to
thereby rotate the gear 53, which in turn is transmitted to the
gear 28 engaging with the gear 53, to thereby rotate the gear 28.
Accordingly, the drum 2 connected to the gear 28 through the shaft
bar 26A, as well as the center bar 3 connected to the drum 2 (the
shaft bar 26B), can be rotated about the center of the axle
thereof.
[0078] In the present embodiment, the gears made of
polymethylpentene (TPX.TM.) are illustrated. However, the gears may
be made of other materials with chemical resistance (resistance to
the plating solution), such as polypropylene (PP) resin. Though in
the present embodiment, the rotation of the motor 50 is transmitted
to the drum 2 through the gears 51, 52, 53 and 28, there is no
limitation as long as the rotation of the motor 50 is transmitted
to the drum 2. For example, the rotation may be transmitted to the
drum 2 through a belt or the like which is made of materials with
chemical resistance.
(Support Member 6)
[0079] The support member 6 is made of acrylic resin, which serves
as a chassis of the barrel plating device 1 and configured for
supporting the drum 2, the electrode shielding part 4 and the drive
mechanism 5 (see FIGS. 1 and 2). In the support member 6, as shown
in FIG. 7, guide grooves 61 are formed for slidably receiving and
supporting the slide shaft bearings 27A, 27B in which the shaft
bars 26A, 26B are inserted, respectively.
[0080] To the support member 6, the electrode shielding part 4 and
a fixing member 62, both serve as fixing means, are attached in
order to prevent the slide shaft bearings 27A, 27B in which the
shaft bars 26A, 26B are inserted, from detaching from the
respective guide grooves 61, during the operation of the barrel
plating device 1 (the rotation of the drum 2).
[0081] The guide groove 61 is configured in such a manner that the
drum 6 is removably attached to the support member 6 by slidably
moving the slide shaft bearings 27A, 27B in which the shaft bars
26A, 26B are inserted, respectively (see FIG. 7B). With this
configuration, the drum 2 is easily removed, and thus a replacement
of the drum and introduction and removal of objects are facilitated
to thereby improve workability.
[0082] In addition, during the operation of the barrel plating
device 1 (the rotation of the drum 2), the shaft bar 26B is
rotatably fixed by insertion into the liquid-proof part 43 of the
electrode shielding part 4 supported on the side face of the
support member 6, as shown in FIGS. 1 and 2, while the shaft bar
26A is rotatably fixed by the fixing member 62, as shown in FIGS. 1
and 7C.
[0083] As shown in FIGS. 7B and 7C, the fixing member 62 made of
acrylic resin is configured for fixing the shaft bar 26A through
the slide shaft bearing 27A, so that the shaft bar 26A does not
come off of the support member 6 (guide groove 61) during the
rotation of the drum 2.
[0084] It should be noted that, when the fixing member 62 is fixing
the shaft bar 26A through the slide shaft bearing 27A, the fixing
member 62 is fastened to the support member 6 with, for example, a
screw made of PEEK resin (not shown).
[0085] With this configuration, the shaft bars 26A, 26B together
with the slide shaft bearings 27A, 27B, are prevented from coming
off of the support member 6 (guide groove 61) during the rotation
of the drum 2. As a result, the drum 2 is stably rotated without
coming off of a use position during the operation of the plating
device 1 (during a rotation of the drum 2).
[0086] In the present embodiment, the slide shaft bearings 27A, 27B
in which the shaft bars 26A, 26B are inserted, respectively, are
slidably moved or fixed by the fixing member 62 and the like.
However, the shaft bars 26A, 26B may be directly moved in the guide
grooves 61, or directly fixed to the support member 6, without a
presence of the slide shaft bearings 27A, 27B, as long as the drum
2 is rotatably supported. In this case, the shaft bar 26A is
directly and rotatably fixed by the fixing member 62.
[0087] The components of the barrel plating device 1 have been
described in detail. In the present embodiment, the drum 2
(including the drum body 20, the lid parts 25A, 25B and the like),
the electrode shielding part 4 (including the housing 42, the
fixing plate 43b and the like), the support member 6 and the fixing
member 62 are made of acrylic resin. However, other resins may be
used as long as they have chemical resistance and heat resistance,
and the same level of hardness as that of acrylic resin.
[0088] Next, an outline of the operation of the barrel plating
device 1 will be explained (see FIGS. 1 and 2, as appropriate)
[0089] First, the center bar 3 is connected to the shaft bar 26B,
and objects P to be plated (not shown) are put in the drum 2. The
volume of the objects P put in the drum 2 is adjusted so that the
objects P and the center bar 3 are electrically connected when the
drum 2 is in a horizontal state, and that the objects P are
satisfactorily stirred when the drum 2 is being rotated. The volume
is preferably a half of the total volume of the drum 2, as shown in
FIG. 8, for example.
[0090] Next, while maintaining the drum 2 in a horizontal state,
the slide shaft bearings 27A, 27B in which the shaft bars 26A, 26B
are inserted, respectively, are slidably moved in the guide grooves
61 (see FIGS. 7A-7C), so that the drum 2 is rotatably supported by
the support member 6. Subsequently, the gear 28 connected to the
shaft bar 26A of the drum 2 is engaged with the gear 53 of the
drive mechanism 5, to thereby connect the drum 2 with the drive
mechanism 5. The fixing member 62 is attached to thereby rotatably
fix the shaft bar 26A through the slide shaft bearing 27A. In
addition, the shaft bar 26B of the drum 2 is inserted in the
liquid-proof part 43 of the electrode shielding part 4, to thereby
electrically connect the shaft bar 26B with the electrode 41, and
at the same time, to rotatably fix the shaft bar 26B.
[0091] The barrel plating device 1 having the above-described
configuration is placed in the plating bath 11 (not shown) storing
the plating solution L, in such a manner that the entire drum 2 (or
at least the objects P to be plated and the center bar 3) is
immersed in the plating solution L. Then, the motor 50 of the drive
mechanism 5 is driven, and the rotation of the motor 50 is
transmitted to the drum 2 through the gears 51, 52, 53 and 28, to
thereby rotate the drum 2. The positive electrode (not shown)
disposed in the plating bath 11 and the center bar 3 (negative
electrode) are electrically connected, to thereby form a plating
film on a surface of the object P.
[0092] According to the barrel plating device 1 of the present
embodiment having the above-mentioned configuration, the drum 2 and
the center bar 3 integrally rotate while maintaining electrical
connection between the center bar 3 and the electrode 41.
Therefore, as shown in FIG. 8, gap is not formed between the center
bar 3 and the objects P to be plated in the drum 2, which prevents
a generation of high-current-density part. As a result, there is
prevented an occurrence of burnt deposit in a plating film formed
on a surface of the plated object P.
[0093] The configuration and the outline of the operation of the
barrel plating device 1 have been described. However, the present
invention should not be limited to the above-described embodiments.
Specific configuration may be modified within the scope of the
present invention without deviating from the spirit of the present
invention. For example, in the above-mentioned embodiment, the
center bar 3 and the shaft bar 26B as separate components are
assembled and used as a single conductive member. However, the
center bar 3 and the shaft bar 26B may be integrally formed into a
single component as a conductive member.
* * * * *