U.S. patent application number 14/371638 was filed with the patent office on 2014-11-20 for plating device.
The applicant listed for this patent is HONDA MOTOR CO., LTD.. Invention is credited to Yutaka Arimura, Yasuo Shimizu, Atsuhiko Yoneda.
Application Number | 20140339077 14/371638 |
Document ID | / |
Family ID | 48781378 |
Filed Date | 2014-11-20 |
United States Patent
Application |
20140339077 |
Kind Code |
A1 |
Arimura; Yutaka ; et
al. |
November 20, 2014 |
PLATING DEVICE
Abstract
Disclosed is a plating device that has a plating tank that
retains a plating fluid and carries out magnetic metal plating on a
shaft shaped member immersed in the plating fluid as a negative
electrode. The plating device is provided with: a plurality of
shielding jigs that are fitted to the outer peripheral surface of
the shaft shaped member and regulate the part of the shaft shaped
member being plated; and a positive electrode provided in the
vicinity of the shaft shaped member and having an output part that
faces the part being plated. A center position in the axial
direction of the shaft shaped member for the part being plated and
a center position of the output part are aligned within a
prescribed allowable value for the center positions.
Inventors: |
Arimura; Yutaka; (Wako-shi,
JP) ; Shimizu; Yasuo; (Wako-shi, JP) ; Yoneda;
Atsuhiko; (Wako-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONDA MOTOR CO., LTD. |
MINATO-KU, TOKYO |
|
JP |
|
|
Family ID: |
48781378 |
Appl. No.: |
14/371638 |
Filed: |
December 21, 2012 |
PCT Filed: |
December 21, 2012 |
PCT NO: |
PCT/JP2012/083272 |
371 Date: |
July 10, 2014 |
Current U.S.
Class: |
204/275.1 ;
204/242 |
Current CPC
Class: |
C25D 17/008 20130101;
C25D 17/06 20130101; C25D 3/56 20130101; C25D 17/12 20130101; C25D
21/12 20130101; C25D 7/001 20130101; C25D 5/08 20130101 |
Class at
Publication: |
204/275.1 ;
204/242 |
International
Class: |
C25D 21/12 20060101
C25D021/12; C25D 3/56 20060101 C25D003/56; C25D 17/06 20060101
C25D017/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 11, 2012 |
JP |
2012-003152 |
Claims
1. A plating device comprising a plating tank retaining a plating
fluid, the device being used to carry out magnetic alloy plating of
a shaft-shaped member immersed in the plating fluid, the
shaft-shaped member serving as a negative electrode, wherein the
plating device includes a plurality of shielding jigs fitted about
an outer peripheral surface of the shaft-shaped member and defining
a plated portion on the shaft-shaped member; and a positive
electrode disposed surrounding the shaft-shaped member, and having
an output portion facing the plated portion; characterized in that
the center position of the plated portion and the center position
of the output portion in the axial direction of the shaft-shaped
member are aligned to within a predetermined tolerance relating to
the center position.
2. The plating device of claim 1, wherein a length of the plated
portion and a length of the output portion of the positive
electrode are aligned to within a predetermined tolerance relating
to the length, in an axial direction of the shaft-shaped
member.
3. The plating device of claim 1, further comprising a shield
disposed between the positive electrode and the shaft-shaped
member.
4. The plating device of claim 3, wherein a pattern of the shield
defines a pattern of the output portion of the positive electrode,
the pattern of the shield being determined such that variability of
thickness of the magnetic alloy plating is kept to within an
allowable range.
5. The plating device of claim 3, wherein the shield is of assembly
type detachable from the positive electrode.
6. The plating device of claim 1, further comprising a plating
fluid spray nozzle having a plating fluid spray orifice facing the
plated portion, the plating fluid spray nozzle being of assembly
type detachable from the plating tank.
7. The plating device of claim 6, wherein the center position of
the plated portion and the center position of the plating fluid
spray orifice are aligned to within an tolerance relating to the
center position, in the axial direction of the shaft-shaped
member.
8. The plating device of claim 7, wherein the length of the plated
portion and the length of the plating fluid spray orifice are
aligned to within a prescribed tolerance relating to the length, in
the axial direction of the shaft-shaped member.
9. The plating device of claim 2, further comprising a shield
disposed between the positive electrode and the shaft-shaped
member.
10. The plating device of claim 4, wherein the shield is of
assembly type detachable from the positive electrode.
11. The plating device of claim 2, further comprising a plating
fluid spray nozzle having a plating fluid spray orifice facing the
plated portion, the plating fluid spray nozzle being of assembly
type detachable from the plating tank.
12. The plating device of claim 3, further comprising a plating
fluid spray nozzle having a plating fluid spray orifice facing the
plated portion, the plating fluid spray nozzle being of assembly
type detachable from the plating tank.
13. The plating device of claim 4, further comprising a plating
fluid spray nozzle having a plating fluid spray orifice facing the
plated portion, the plating fluid spray nozzle being of assembly
type detachable from the plating tank.
14. The plating device of claim 5, further comprising a plating
fluid spray nozzle having a plating fluid spray orifice facing the
plated portion, the plating fluid spray nozzle being of assembly
type detachable from the plating tank.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plating device, for
example a plating device for forming magnetostrictive films in a
magnetostrictive torque sensor by a magnetic alloy plating
process.
BACKGROUND ART
[0002] Vehicles are commonly equipped with, for example,
electrically-powered power steering devices. An
electrically-powered power steering device generates assistive
torque to reduce the steering torque needed to be produced in the
steering system through operation of the steering wheel by the
driver. By generating assistive torque, the electrically-powered
power steering device can reduce the burden on the driver. An
electrically-powered power steering device has a steering torque
sensor for detecting steering torque; the torque sensor for
detecting torque, such as steering torque, acting on a shaft-shaped
member (also called a pivot, pinion shaft, or input shaft), can be
constituted, for example, by a magnetostrictive torque sensor which
utilizes magnetostrictive effect by a plurality of magnetostrictive
films having mutually different magnetic anisotropy.
[0003] For example, Patent Literature 1 discloses a plating device
employed for forming two magnetostrictive films by plating of a
plated portion of a shaft-shaped member, doing so prior to
imparting having mutually different magnetic anisotropy to the
films. Due to the flow of current from the positive electrode (a
metal cage or metal pellets) of the plating device to an exposed
portion or non-masked portion (negative electrode, plated portion)
of the shaft-shaped member, metal ions (e.g. Ni ions or Fe ions)
present in the plating fluid are deposited on the negative
electrode side, forming a magnetic alloy plating such as a
magnetostrictive film or the like.
[0004] However, because the lines of current (lines of electrical
force) lead towards the plated portion (negative electrode) from
the entirety of the positive electrode, the lines of current are
dependent upon the pattern, such as the length, of the positive
electrode, and cannot flow uniformly into the plated portion.
Stated another way, depending on the type of specifications
required of an electrically-powered power steering device, it may
be necessary for the lines of current to flow more uniformly into
the plated portion. Specifically, in the plating device disclosed
in the aforementioned Patent Literature 1, it is indicated to form
the shielding jig at the center to a smaller diameter than the
diameter of the shielding jigs above and below, to thereby
establish a uniform current density distribution over the entire
surface of the plated portion. However, the inventors have found
that, in actual practice, the current density distribution over the
surface of the plated portion in an axial direction of a
shaft-shaped member will differ depending on the location of the
plated portion, in a manner dependent upon the pattern of the
positive electrode, and that variability of thickness of the
magnetic alloy plating may not always be kept within the allowable
range, depending on the type of specifications.
PRIOR ART LITERATURE
Patent Literature
[0005] Patent Literature 1: Japanese Patent Application Laid-Open
[0006] Publication No. 2008-101243
SUMMARY OF INVENTION
Technical Problem
[0007] An object of the present invention is to provide a plating
device whereby it is possible to more form a magnetic alloy plating
to more uniform thickness.
Solution to Problem
[0008] According to a first aspect of the present invention, there
is provided a plating device having a plating tank retaining a
plating fluid, the device being used to carry out magnetic alloy
plating of a shaft-shaped member immersed in the plating fluid, the
shaft-shaped member serving as a negative electrode, wherein the
plating device has a plurality of shielding jigs fitted about an
outer peripheral surface of the shaft-shaped member and defining a
plated portion on the shaft-shaped member, and a positive electrode
disposed surrounding the shaft-shaped member, and having an output
portion facing the plated portion. The center position of the
plated portion and the center position of the output portion in the
axial direction of the shaft-shaped member are aligned to within a
predetermined tolerance relating to the center position.
[0009] In cases in which the center position of the plated portion
of a shaft-shaped member and the center position of the output
portion of the positive electrode are aligned in the axial
direction of the shaft-shaped member, the lines of current flowing
into the plated portion are symmetrical with respect to the center
position of the plated portion. Consequently, despite variability
of thickness of the magnetic alloy plating, by virtue of being
symmetrical with respect to the center position of the plated
portion, the magnetic alloy plating can be formed to more uniform
thickness.
[0010] Stated another way, in cases in which the lines of current
flowing into a plated portion are not symmetrical with respect to
the center position of the plated portion, and moreover the
thickness of the magnetic alloy plating is at its thickest or
thinnest at a position furthest away from the center position of
the plated portion (one end location of the plated portion), the
difference between that thickness and the thickness of the magnetic
alloy plating at the one end location of the plated portion will
exceed the difference when the lines of current flowing into the
plated portion are symmetrical with respect to the center position
of the plated portion. Consequently, the variability of thickness
of magnetic alloy plating observed when the lines of current
flowing into the plated portion are not symmetrical with respect to
the center position of the plated portion may fail to be kept
within the allowable range at, for example, at one end location of
the plated portion.
[0011] Accordingly, a magnetic alloy plating can be formed to more
uniform thickness by aligning the center position of the plated
portion of the shaft-shaped member and the center position of the
output portion of the positive electrode to within an tolerance
relating to center position, in order to keep the variability of
thickness of magnetic alloy plating to within the allowable range
throughout the entire plated portion.
[0012] In the first aspect, in preferred practice, the length of
the plated portion and the length of the output portion of the
positive electrode are aligned to within a predetermined tolerance
relating to the length, in an axial direction of the shaft-shaped
member.
[0013] In cases in which the length of the plated portion of the
shaft-shaped member and the length of the output portion of the
positive electrode are aligned in the axial direction of the
shaft-shaped member, the lines of current flowing into the plated
portion will be perpendicular to the plated portion surface.
Consequently, the current density distribution will be uniform over
the entire surface of the plated portion, allowing the magnetic
alloy plating to be formed to more uniform thickness.
[0014] Consequently, by aligning the length of the plated portion
of the shaft-shaped member and the length of the output portion of
the positive electrode to within a predetermined tolerance relating
to length such that variability of thickness of magnetic alloy
plating is kept to within the allowable range throughout the entire
plated portion, the magnetic alloy plating can be formed to more
uniform thickness.
[0015] In the first aspect, in preferred practice, the plating
device further has a shield disposed between the positive electrode
and the shaft-shaped member.
[0016] The shield allows positive electrode output portions to be
formed in portions of the positive electrode, instead of using the
entire positive electrode as the output portion.
[0017] In the first aspect, in preferred practice, the pattern of
the shield defines the pattern of the output portion of the
positive electrode, the pattern of the shield being determined such
that variability of thickness of the magnetic alloy plating is kept
to within an allowable range.
[0018] Depending on the type of positive electrode, there may be
instances in which the center position of the plated portion of the
shaft-shaped member and the center position of the output portion
of the positive electrode cannot be aligned. Or, depending on the
type of positive electrode, there may be instances in which the
lengths of the plated portion of the shaft-shaped member and the
length of the output portion of the positive electrode cannot be
aligned. Accordingly, the pattern (the center position and length)
of the output portion of the positive electrode is adjusted through
adjustment of the pattern of the shield, whereby the metallic alloy
plating can be formed to more uniform thickness.
[0019] Moreover, depending on the type of shaft-shaped member, the
pattern, such as the length, of the plated portion may differ. In
such cases as well, with a single positive electrode, by adjusting
the pattern of the shield, the metallic alloy plating can be formed
to more uniform thickness while achieving compatibility with
shaft-shaped members and plated portions of various different
types.
[0020] In the first aspect, the shield is preferably of assembly
type detachable from the positive electrode.
[0021] By making the shield replaceable, the metallic alloy plating
can be formed to more uniform thickness, while achieving
compatibility with shaft-shaped members and plated portions of
various different types.
[0022] In the first aspect, in preferred practice, the plating
device is further provided with a plating fluid spray nozzle having
plating a fluid spray orifice facing the plated portion, the
plating fluid spray nozzle being of assembly type detachable from
the plating tank.
[0023] Depending on the type of shaft-shaped member, the patterns,
such as the center positions, of the plated portions may differ. In
such cases, by replacing the plating fluid spray nozzle having
plating a fluid spray orifice which faces the plated portion, the
metallic alloy plating can be formed to more uniform thickness
while achieving compatibility with shaft-shaped members and plated
portions of various different types.
[0024] In the first aspect, in preferred practice, the center
position of the plated portion and the center position of the
plating fluid spray orifice are aligned to within a tolerance
relating to center position, in the axial direction of the
shaft-shaped member.
[0025] In cases in which the center position of the plated portion
of the shaft-shaped member and the center position of the plating
fluid spray orifice (the output portion of the plating fluid
nozzle) are aligned in the axial direction of the shaft-shaped
member, the lines of flow of the plating fluid flowing to the
plated portions will be symmetrical with respect to the center
positions of the plated portions. Consequently, despite variability
of thickness of magnetic alloy plating, there is symmetry with
respect to the center positions of the plated portions, and the
metallic alloy plating can be formed to more uniform thickness.
Even in cases in which the shaft-shaped member is rotated to stir
the plating fluid inside the plating tank, the metallic alloy
plating can be formed to more uniform composition.
[0026] In the first aspect, in preferred practice, the length of
the plated portion and the length of the plating fluid spray
orifice are aligned to within a tolerance relating to the length,
in an axial direction of the shaft-shaped member.
[0027] In cases in which the length of the plated portion of the
shaft-shaped member and the length of the plating fluid spray
orifices (the output portion of the plating fluid nozzle) are
aligned in the axial direction of the shaft-shaped member, the
density of the metal ions flowing to the plated portion will be
uniform over the entirety of the plated portions. Consequently, the
metallic alloy plating can be formed to more uniform thickness.
Even in cases in which the shaft-shaped member is rotated to stir
the plating fluid inside the plating tank, the metallic alloy
plating can be formed to more uniform composition.
[0028] It will be readily apparent to a person skilled in the art
that various modifications to the aspects according to the present
invention shown herein by way of examples are possible without
departing from the spirit of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1 is a schematic view illustrating a detailed example
arrangement of a plating device according to the present
invention;
[0030] FIG. 2 (A) illustrates a general example arrangement of the
plating device of FIG. 1, and FIG. 2 (B) illustrates a detailed
example arrangement of the interior of the plating tank shown in
FIG. 1;
[0031] FIG. 3 (A) illustrates another general example arrangement
of the plating device of FIG. 1;
[0032] FIG. 3 (B) illustrates another detailed example arrangement
of the interior of the plating tank shown in FIG. 1;
[0033] FIG. 4 is a top view showing the plating tank of FIG. 1;
[0034] FIG. 5 (A) is a view showing an example external appearance
of a plating fluid spray nozzle shown in FIG. 2 (B);
[0035] FIG. 5 (B) is a view showing a general example arrangement
of an output portion of the plating fluid spray nozzle shown in
FIG. 5 (A);
[0036] FIG. 6 (A) is a view showing an example external appearance
of the plating fluid spray nozzle shown in FIG. 3 (B);
[0037] FIG. 6 (B) illustrates a modification example of a positive
electrode of the plating device shown in FIG. 1;
[0038] FIG. 7 is an exploded perspective view illustrating a metal
cage and a shield of FIG. 3 (B);
[0039] FIG. 8 (A) illustrates a modification example of the shield
of FIG. 7;
[0040] FIG. 8 (B) illustrates a modification example of the
positive electrode of FIG. 3 (B);
[0041] FIG. 9 (A) to 9 (H) respectively show descriptive diagrams
in which the center position of a plated portion and the center
position of an output portion are substantially aligned; and
[0042] FIG. 10 (A) to 10 (H) respectively illustrate other
descriptive diagrams in which the center position of a plated
portion and the center position of an output portion are
substantially aligned.
DESCRIPTION OF EMBODIMENTS
[0043] Certain preferred embodiments of the present invention will
be described in detail below with reference to the accompanying
drawings. Persons skilled in the art should keep in mind that the
present invention is not unduly limited to the embodiments
described below.
Embodiments
[0044] FIG. 1 shows a detailed schematic example of a plating
device according to the present invention, and FIG. 2 (A) shows
primarily a simplified example (or enlarged view) of the scheme of
the plating device (or output portions of the positive electrode)
according to the present invention. In the example of FIG. 1, the
plating device 1 is provided with a shield 10m situated between the
positive electrode 10 and a shaft-shaped member 5; a characterizing
feature of the example in FIG. 2 (A) is that the output portion 10s
of the positive electrode 10 is defined by the shield 10m. Stated
another way, a characterizing feature of the plating device 1 of
FIG. 1 is that the plating device of Patent Literature 1 is
improved upon. As will be discussed below, depending on the type of
positive electrode 10, the plating device 1 need not be provided
with the shield 10m, as long as the magnetic alloy plating can be
formed to uniform thickness by the output portion 10s.
[0045] In the example of FIG. 1, the plating device 1 has a plating
tank 3 retaining a plating fluid 2, and is designed to carry out
magnetic alloy plating on the shaft-shaped member 5 which is
immersed as a negative electrode in the plating fluid 3. In the
example of FIG. 2 (A), the plating device 1 is provided with a
plurality of shield jigs 13, 14, 15 installed about an outside
peripheral face of the shaft-shaped member 5, for defining plated
portions 5s of the shaft-shaped member 5; and with the positive
electrode 10 situated surrounding the shaft-shaped member 5, and
having the output portion 10s which faces the plated portion
5s.
[0046] Referring to FIG. 2 (A), the plurality of shield jigs 13,
14, 15 are constituted by the shield jigs 13, 15 at the upper and
lower ends, and the intermediate shield jig 14 situated between the
shield jigs 13, 15 at either end. The plated portion 5s is
constituted by sections of the shaft-shaped member 5 which are
situated inwardly from the shield jigs 13, 15 at either end, and
which are not covered by the shield jig 14. Stated another way, the
plated portion 5s is constituted by two sections of the
shaft-shaped member 5 which are positioned between adjacent shield
jigs among the plurality of shield jigs 13, 14, 15 (i.e., between
the between adjacent shield jigs 13, 14 and between the adjacent
shield jigs 14, 15). While the plated portion 5s is constituted,
for example, by two sections of the shaft-shaped member 5, the
length (profile length) of the plated portion 5s, ignoring the
space between the two sections (the section covered by the shield
jig 14) is equal to the distance 5l from one end of the plated
portion 5s to the other end. In an axial direction J of the
shaft-shaped member 5, the position of the one end (bottom portion)
of the shaft-shaped member 5 is 0 (the origin), and the center
position of the plated portion 5s is 5c.
[0047] Referring to FIG. 2 (A), the shield 10m is constituted by a
plurality of members, and like the plated portion 5s, the output
portion 10s of the positive electrode 10 is constituted by sections
which are defined by a plurality of members, which sections are not
covered or shielded by the plurality of members. The length
(profile length) of the output portion 10s is the distance 10l from
one end of the output portion 10s to the other end, and the center
position of the output portion 10s in the axial direction J of the
shaft-shaped member 5 is 10c. In cases in which the center position
of the plated portion 5s of the shaft-shaped member 5 and the
center position 10c of the output portion 10s of the positive
electrode 10 are aligned, the lines of current flowing into the
plated portion 5s will be symmetrical with respect to the center
position of the plated portion 5s. Consequently, variation in the
thickness of the magnetic alloy plating will be symmetrical with
respect to the center position of the plated portion 5s as well,
and the magnetic alloy plating can be formed to uniform thickness.
However, it is not necessary for the center position 5c and the
center position 10c of the output portion 10s of the positive
electrode 10 to be perfectly aligned, and it is sufficient for the
two to be substantially aligned, as discussed below.
[0048] In the example of FIG. 2 (A), the length 5l of the plated
portion 5s of the shaft-shaped member 5 and the length 10l of the
output portion 10s of the positive electrode 10 in the axial
direction J of the shaft-shaped member 5 are preferably
substantially aligned, as discussed below. The length 5l of the
plated portion 5s may be slightly greater than the length 10l of
the output portion 10s, or the two may be perfectly aligned, or the
length 5l of the plated portion 5s may be slightly shorter than the
length 10l of the output portion 10s.
[0049] In the example of FIG. 2 (A), the center position 5c of the
plated portion 5s of the shaft-shaped member 5 and the center
position 26c of the output portion of plating fluid spray nozzles 9
(plating fluid spray orifices 26), discussed later, are preferably
substantially aligned in the axial direction J of the shaft-shaped
member 5. Further, the length 61 of the plated portion 5s of the
shaft-shaped member 5 and the length 261 of the output portion of
the plating fluid spray nozzles 9 are preferably substantially
aligned in the axial direction J of the shaft-shaped member 5.
[0050] In the example of FIG. 1, the plating device 1 is further
provided with a plating fluid regulating tank 4 for regulating the
temperature and the like of the plating fluid 2, and with a rotary
retainer device 6 rotatably retaining the shaft-shaped member 5
which has the plated portion 5s. The shaft-shaped member 5 is, for
example, a steering shaft comprising chrome molybdenum steel,
retained in a vertical orientation at the center of the plating
tank 3 by a retainer member 12 of the rotary retainer device 6. A
fluid chamber 7 is situated to the outside of the bottom of the
plating tank 3, and a recovery section 8 is situated to the outside
in the upper portion of the plating tank; in the interior of the
plating tank 3 are situated not only the positive electrode 10 and
the plated portion 5s (negative electrode), but also the plating
fluid spray nozzles 9, which are made of insulating resin, for
example. As discussed below, the plating fluid spray nozzles 9 are
of assembly type detachable from the plating tank 3 or the fluid
chamber 7, for example.
[0051] The plating fluid 2 is an alloy plating fluid containing at
least two species of metal ions (e.g., Ni ions and Fe ions) in
prescribed proportions, and is maintained at predetermined
temperature by the plating fluid regulating tank 4. The shield jigs
13, 14, 15, which are made, for example, of insulating resin, are
installed about the outside peripheral surface of the shaft-shaped
member 5. The shield jigs 13, 14, 15 are of disk shape, preferably
10 mm or larger in size for example, and are separable in
diametrical directions, so as to enable attachment to and
detachment from the shaft-shaped member 5. The diameter of the
intermediate shield jig 14 situated between the shield jigs 13, 15
at either end is preferably formed to be smaller than the diameter
of the shield jigs 13, 15 at either end; the intermediate shield
jig 14 may be omitted as well.
[0052] The rotary retainer device 6 is provided with a rotary shaft
18 made of metal, furnished at a vertical orientation; a
lifting/lowering mechanism 19 situated in an intermediate portion
of the rotary shaft 18; a bearing 20 situated in a joined portion
of the rotary shaft 18 and the lifting/lowering mechanism 19; the
retainer member 12 situated at one end of the rotary shaft 18; a
motor 21 situated at the other end of the rotary shaft 18; and a
feeder brush 23 electrically connected to the negative pole of a
power supply 22 situated in proximity to the motor 21. Through up
and down motion of the rotary shaft 18 by the lifting/lowering
mechanism 19, the rotary retainer device 6 is able to immerse the
shaft-shaped member 5 in the plating fluid 2, or withdraw the
shaft-shaped member 5 up and out from the plating fluid 2. The
rotary retainer device 6 is constituted such that the shaft-shaped
member 5 is rotated through rotation of the rotary shaft 18 by the
motor 21.
[0053] The plating fluid regulating tank 4 is provided with a
stirrer 29, a temperature regulator 30, and a heater 31; the
plating fluid 2 is retained inside the plating fluid regulating
tank 4. Through stirring of the plating fluid 2 by the stirrer 29,
for example, the Ni ion and Fe ions in the plating fluid 2 can be
uniformly dispersed, as well as producing uniform temperature
throughout the plating fluid 2. The temperature regulator 30
measures the temperature of the plating fluid 2, and controls the
heater 31 to maintain the plating fluid 2 at the prescribed
temperature.
[0054] The plating fluid 2 within the plating fluid regulating tank
4 is supplied to the fluid chamber 7 interior via a plating fluid
supply line 32 through which the plating fluid regulating tank 4
interior and the fluid chamber 7 interior communicate. A pump 33, a
strainer 34, and a flow meter 35 are situated midway along the
plating fluid supply line 32. A controller 36 for regulating the
flow rate of the plating fluid 2 is also provided, the controller
36 being connected to the pump 33 via an inverter 37. The flow rate
of the plating fluid 2 passing through the plating fluid supply
line 32 is measured by the flow meter 35, and the controller 36
compares the measured value thereof to a preset value, and controls
the inverter 37. Through regulation of the pump flow rate of the
pump 33 by the inverter 37, the flow rate of the plating fluid 2
supplied to the fluid chamber 7 interior, i.e., the flow rate of
the plating fluid 2 sprayed from the plating fluid spray orifices
26 (FIG. 2B) is regulated. Dust or other foreign matter in the
plating fluid 2 in the plating fluid supply line 32 is filtered out
by the strainer 34.
[0055] FIG. 2 (B) shows a detailed schematic example of the
interior of the plating tank 3 shown in FIG. 1. FIG. 3 (A)
primarily shows another simplified example (enlarged view) of the
scheme of the output portion 10s of the positive electrode 10 of
the plating device 1 shown in FIG. 1; and FIG. 3 (B) shows another
detail schematic example showing the interior of the plating tank 3
of the plating device 1 shown in FIG. 1. In the example of FIG. 3,
the shield jig 14 situated between the shield jigs 13, 15 at either
end is omitted. Stated another way, it is acceptable for the space
between the two magnetostrictive films prior to being imparted with
mutually different magnetic anisotropy to be omitted, instead
forming a single magnetic alloy plating in a single plated portion
5s, and to then impart mutually different magnetic anisotropy to
the single magnetic alloy plating, forming a magnetostrictive film
having two functions. Furthermore, in the example of FIG. 3, the
plated portion 5s is positioned [further] towards the upper side of
the plating fluid 2, as compared with the example in FIG. 2.
[0056] In the example of FIG. 2 (B) and the example of FIG. 3 (B),
the plating fluid spray nozzles 9 are of assembly type detachable
from the plating tank 3 via the fluid chamber 7. A flange 9f is
situated in the bottom part of the plating fluid spray nozzle 9,
and the plating fluid spray nozzle 9 or the flange 9f is fastened
to the fluid chamber 7 by a plurality of bolts 9b. The flange 9f
and the bolts 9b are merely one example of fasteners; the fasteners
could be constituted by other members or other parts.
[0057] Depending on the type of shaft-shaped member 5, the position
at which the plated portion 5s is situated on the shaft-shaped
member 5 (the center position 5c) will differ; in the example of
FIG. 3 (B), the plated portion 5s is positioned [further] towards
the upper side of the plating fluid 2, as compared with the example
in FIG. 2 (B). In this case as well, by replacing the plating fluid
spray nozzles 9 having the plating fluid spray orifices 26 which
face the plated portion 5s, the metallic alloy plating can be
formed to more uniform thickness, while achieving compatibility
with shaft-shaped members 5 and plated portions 5s of various
different types. Stated another way, the plating fluid spray
nozzles 9 of FIG. 2 (B) can be extended in length, positioning a
plurality of the plating fluid spray orifices 26 at the top, to
prepare the replacement plating fluid spray nozzles 9 of FIG. 3 (B)
for example.
[0058] As discussed below, by replacing the shield 10m,
compatibility with shaft-shaped members 5 and plated portions 5s of
various different types can be achieved in the same manner as with
replacement of the plating fluid spray nozzles 9.
[0059] In the example of FIG. 2 (B) and the example of FIG. 3 (B),
the plating tank 3 is constituted, for example, by a cylindrical
tank made of an insulating resin, or one made of metal to which an
insulating coating film has been applied to the inside surface. The
plating fluid 2 is supplied to the interior of the plating tank 3
from the interior of the fluid chamber 7 via the plating fluid
spray nozzles 9, and overflows into the recovery section 8 from the
upper edge of the plating tank 3, to be recovered in the plating
fluid regulating tank 4 of FIG. 1, via a plating fluid recovery
line 11 situated at the bottom of the recovery section 8.
[0060] When the power supply 22 is ON, the plating fluid 2 is
sprayed from the plating fluid spray orifices 26 towards the plated
portion 5s of the rotating shaft-shaped member 5. In so doing, the
plating fluid 2 is supplied to the entire surface of the plated
portion 5s, and uniform flow can be obtained over the entire
surface of the plated portion 5s. Because the shaft-shaped member 5
rotates, the concentration of Ni ions and the concentration of Fe
ions in the plating fluid 2 are maintained at constant levels over
the entire surface of the plated portion 5s.
[0061] In the example of FIG. 2 (B) and the example of FIG. 3 (B),
masking tape 16 is wrapped about the outside peripheral face of the
shaft-shaped member 5, in a section above the upper shield jig 13
and a section below the lower shaft jig 15 (see FIG. 5 (A) and FIG.
6 (A)). The plated portion 5s of the shaft-shaped member 5 is
constituted by the section not covered by the shield jigs 13, 14,
15 or the shield jigs 13, 15, and the masking tape 16.
[0062] In the example of FIG. 2 (B) and the example of FIG. 3 (B),
the positive electrode 10 is constituted by a metal cage 27 of
cylindrical shape open at the top end and closed at the bottom end,
and a plurality of metal pellets 28 contained within the metal cage
27. The metal cage 27 is arranged encircling the plating fluid
spray nozzle 9 which is located to the inside of the inside
peripheral surface thereof, and is supported by fasteners, not
illustrated, in such a way as to not contact the inside peripheral
surface and bottom surface of the plating tank 3. The metal cage 27
is formed, for example, of mesh comprising Ti, which does not
dissolve into the plating fluid 2 when current is passed through,
and is electrically connected to the positive pole of the power
supply 22 (FIG. 1). The metal pellets 28, on the other hand, are
pellets made, for example, of an Ni--Fe alloy which is dissolvable
in the plating fluid 2, a pellet mixture of metal pellets of Ni
alone and metal pellets of Fe alone, or the like. While the metal
pellets 28 are employed as the positive electrode 10, spheres or
any other shape would be acceptable, provided that the size is one
that may be accommodated within the metal cage 27, and [large
enough] to not leak out through the mesh of the metal cage 27.
[0063] Even when the Ni ions and the Fe ions in the plating fluid 2
are consumed in the course of carrying out Ni--Fe alloy plating, Ni
ions and Fe ions dissolve into the plating fluid 2 from the metal
pellets 28 through electrolysis, and maintain the concentration of
Ni ions and the concentration of Fe ions in the plating fluid 2 at
constant levels, whereby the plating fluid 2 can be easily managed.
Because the constitution in one in which the metal pellets 28 are
contained within the metal cage 27, the metal cage 27 can be easily
supplied with the metal pellets 28, even during the plating
process.
[0064] FIG. 4 shows a top view of the plating tank 3 shown in FIG.
1. FIG. 5 (A) shows an example of the exterior of the plating fluid
spray nozzle 9 shown in FIG. 2 (B); and FIG. 6 (A) shows an example
of the exterior of the plating fluid spray nozzle 9 shown in FIG. 3
(B). FIG. 5 (B) primarily shows a simplified schematic example of
the output portion of the plating fluid spray nozzle 9 shown in
FIG. 5 (A); and FIG. 6 (B) shows a modification example of the
positive electrode 10 of the plating device 1 shown in FIG. 1. In
the example of FIG. 4, the plating fluid spray nozzles 9 are, for
example, four in number, arranged at equidistant intervals on a
circle centered on the shaft-shaped member 5. The number of plating
fluid spray nozzles 9 may be four or more, or one.
[0065] In the example of FIG. 6 (B), the entire positive electrode
10 faces the plated portion (negative electrode) 5s. Stated another
way, the entire positive electrode 10 of FIG. 6 (B) constitutes the
output portion 10s of the positive electrode 10 of FIG. 2 (A), the
positive electrode 10 of FIG. 6 (B) being fastened such that the
center position 5c of the plated portion 5s and the center position
10c of the output portion 10s are aligned. In the example of FIG. 6
(B), the plating device 1 or the plating tank 3 may be provided
with the shield 10m shown, for example, in FIG. 4.
[0066] In the example of FIG. 5 (A) and the example of FIG. 5 (B),
the plurality of plating fluid spray orifices 26 are situated on
the outside peripheral face of the plating fluid spray nozzle 9 so
as to face the plated portion 5s, and are arranged parallel to the
axial direction of the shaft-shaped member 5. In the example of
FIG. 5 (A), the plurality of plating fluid spray orifices 26 are
separated into a plurality of regions (for example, an upper region
and a lower region) in corresponding fashion to individual plated
portions 5s, 5s (for example, two plated sub-portions 5s, 5s of the
entire plated portion 5s). The lengths 26l1, 26l2 of the individual
regions (the upper region and the lower region) are preferably
substantially aligned with the length 5l1, 5l2 of each one
corresponding plated sub-portions 5s. Further, the centers 26c1,
26c2 of the individual regions (the upper region and the lower
region) are preferably substantially aligned with the centers 5c1,
5c2 of each one corresponding plated sub-portion 5s. In so doing,
the magnetic alloy plating can be formed to more uniform thickness,
and the magnetic alloy plating can be formed to more uniform
composition, even in cases in which the shaft-shaped member 5 is
rotated to stir the plating fluid 2 inside the plating tank 3.
[0067] In the example of FIG. 5 (B), for example, two sub-output
portions in the entire output portion 10s of the positive electrode
10 are separated into a plurality of regions (for example, an upper
region and a lower region) in corresponding fashion to the
individual plated sub-portions 5s, the lengths 10l1, 10l2 of the
individual regions (the upper region and the lower region)
preferably being substantially aligned with lengths 5l, 5l2 of each
one corresponding plated sub-portion 5s. Further, the centers 10c1,
10c2 of the individual regions (the upper region and the lower
region) are preferably substantially aligned with the centers 5c1,
5c2 of each one corresponding plated sub-portion 5s. In so doing,
the magnetic alloy plating can be formed to more uniform thickness
in each of the individual plated portion 5s, 52 (for example, the
two plated sub-portions 5s, 5s of the entire plated portion
5s).
[0068] FIG. 7 shows an example of an exploded perspective view of
the metal cage 27 and the shield 10m of FIG. 3 (B). In the example
of FIG. 7, the shield 10m, which is cylindrical in shape and has
three openings for example, can be fastened to the inside surface
(inside peripheral surface) of the metal cage 27, for example, by
bolts 10b, a frame 10f1, and nuts (not illustrated). The pattern of
the shield 10m defines the pattern of the output portion 10s of the
positive electrode 10, the shield 10m preferably being of assembly
type detachable from the positive electrode 10 or to the metal cage
27, for example. Stated another way, the section corresponding to
the metal pellets 28 or the positive electrode 10 at the opening of
the shield 10m defines the output portion 10s of the positive
electrode 10, the shield 10m preferably being of replaceable type.
Alternatively, the metal cage 27 or the positive electrode 10 may
be of replaceable type.
[0069] The metal cage 27 can be fastened to the plating tank 3 of
FIG. 1 by a frame 10f2 and fasteners such as members or parts (not
illustrated) or the like. The shield 10m and the fasteners (the
bolts 10b, the frame 10f1, the frame 10f2, and the like) are
insulators, both being constituted, for example, of an insulating
substance, or the surfaces of both being coated with an insulating
coating, for example.
[0070] In cases in which the metal cage 27 and the shield 10m of
FIG. 7 are applied to FIG. 2 (B), the lower side of the cylindrical
shield 10m would be furnished, for example, with three openings
while closing off the opening in the section corresponding to the
shield jig 14; in other words, the cylindrical shield 10m would be
furnished, for example, with [a total of] six openings.
[0071] FIG. 8 (A) shows a modification example of the shield 10m of
FIG. 7, and FIG. 8 (B) shows a modification example of the positive
electrode 10 of FIG. 3 (B). In the example of FIG. 8 (A), the
shield 10m is constituted by two cylindrical members. When the
shield 10m, 10m of FIG. 8 (A) is fastened to the metal cage 27, the
output portion 10s of the metal pellets 28 or the positive
electrode 10 is defined by the space between the shield 10m, 10m.
Stated another way, the pattern of the shield 10m, 10m defines the
pattern of the output portion 10s of the metal pellets 28 or the
positive electrode 10.
[0072] Rather than fastening the shield 10m, 10m of FIG. 8 (A) to
the metal cage 27, it may, for example, be fastened to six positive
electrodes 10, 10, 10, 10, 10, 10 constituted by six plate-shaped
members, by bolts 10b, nuts 10n, or the like, as in the example
shown in FIG. 8 (B), for example. Stated another way, rather than
having the positive electrode 10 be constituted by the metal cage
27 or the metal pellets 28, the plating device 1 may employ
non-dissolving plate-shaped positive electrodes 10.
[0073] In the case of application of the shield 10m, 10m of FIG. 8
(A) to FIG. 2 (B), the shield 10m would be constituted, for
example, by three cylindrical members (not illustrated) including a
cylindrical member in a section corresponding to the shield jig 14,
with spaces between adjacent members situated at the bottom
side.
[0074] FIG. 9 (A) to FIG. 9 (H) respectively show descriptive
diagrams in which the center position 5c of the plated portion 5s
(or the center positions 5c1, 5c2 of the plated sub-portions 5s)
and the center position 10c of the output portion 10s (or the
center positions 10c1, 10c2 of the sub-output portions 10s) are
substantially aligned. FIG. 9 (C) shows the variability in film
thickness of, for example, Ni--Fe alloy plating, when the center
position 5c of the plated portion 5s and the center position 10c of
the output portion 10s are perfectly aligned, and represents film
thickness, for example, at six different positions in the plated
portion 5s of FIG. 3 (B), in the axial direction J of the
shaft-shaped member 5. The ranges indicated by pairs of dotted
lines in FIG. 9 (C) are allowable range relating to film thickness,
and are determined according to specifications. FIG. 9 (A) and FIG.
9 (B) show the variability in film thickness when the center
position 10c of the output portion 10s is higher than the center
position 5c of the plated portion 5s; the center position 10c in
FIG. 9 (A) is higher than the center position 10c in FIG. 9 (B).
FIG. 9 (D) to FIG. 9 (H) show the variability in film thickness
when the center position 10c of the output portion 10s is lower
than the center position 5c of the plated portion 5s; the center
positions 10c in FIG. 9 (D) to FIG. 9 (H) are progressively lower
in the order FIG. 9 (D) to FIG. 9 (H), with the center position 10c
in FIG. 9 (H) being the lowest.
[0075] In each of FIG. 9 (A) to FIG. 9 (F), film thickness at all
six positions is maintained with in the allowable range, whereas in
each of FIG. 9 (G) to FIG. 9 (H), film thickness at all six
positions is not maintained within the allowable range.
Consequently, [it is not necessary for] the center position 5c of
the plated portion 5s and the center position 10c of the output
portion 10s to be perfectly aligned (FIG. 9 (C)), it being
acceptable for the center position 10c of the output portion 10s to
be slightly higher than the center position 5c of the plated
portion 5s (FIG. 9 (A), FIG. 9 (B)), or for the center position 10c
of the output portion 10s to be slightly lower than the center
position 5c of the plated portion 5s (FIG. 9 (D), FIG. 9 (E), FIG.
9 (F)), provided that the center position 5c of the plated portion
5s (or the center positions 5c1, 5c2) and the center position 10c
of the positive electrode 10 (or the center positions 10c1, 10c2)
are aligned within the prescribed tolerance relating to center
position, such that the variability of thickness of the magnetic
alloy film is maintained within the acceptable range throughout the
entire plated portion 5s.
[0076] Likewise, it is acceptable for the length 5l of the plated
portion 5s to be longer that the length 10l of the output portion
10s; for the two to be perfectly aligned; or for the length 5l of
the plated portion 5s to be slightly shorter than the length 10l of
the output portion 10s, provided that the length 5l of the plated
portion 5s (or the lengths 5l, 5l2) and length 10l of the output
portion 10s of the positive electrode 10 (or the lengths 10l1,
10l2) are aligned within the prescribed tolerance relating to
length, such that the variability of thickness of the magnetic
alloy film is maintained within the acceptable range throughout the
entire plated portion 5s.
[0077] FIG. 10 (A) to FIG. 10 (H) each respectively show one more
descriptive diagram in which the center position 5c of the plated
portion 5s and the center position 10c of the output portion 10s
are substantially aligned. FIG. 10 (C) shows variability in the
iron composition or proportion of iron in, for example, Ni--Fe
alloy plating, when the center position 5c of the plated portion 5s
and the center position 10c of the output portion 10s are perfectly
aligned. The range indicated by the pair of dotted lines in FIG. 10
(C) is an allowable range relating to iron composition, and is
determined according to specifications. The center positions 10c in
FIG. 10 (A) to FIG. 10 (H) respectively correspond to the center
positions in FIG. 9 (A) to FIG. 9 (H), with the center position 10c
of FIG. 10 (A) being the highest, and the center position 10c of
FIG. 10 (H) being the lowest. In each of FIG. 10 (B) to FIG. 10
(F), the iron composition at all six positions is maintained within
the allowable range, whereas in each of FIG. 10 (G) to FIG. 10 (H),
the iron composition at all six positions is not maintained within
the allowable range.
[0078] It is preferable to take into consideration the iron
composition, not just the film thickness, whereby the center
position 5c of the plated portion 5s (or the center positions 5c1,
5c2) and the center position 10c of the positive electrode 10 (or
the center positions 10c1, 10c2) can be aligned within the
prescribed tolerance relating to center position (FIG. 10 (B) to
FIG. 10 (F), FIG. 9 (B) to FIG. 9 (F)), so that variability of each
component of the magnetic alloy plating is maintained within an
allowable range throughout the entire plated portion 5s. Likewise,
it is preferable to take into consideration the iron composition,
not just the film thickness, whereby the length 5l of the plated
portion 5s (or the lengths 5l, 5l2) and length 10l of the output
portion 10s of the positive electrode 10 (or the lengths 10l1,
10l2) are aligned within the prescribed tolerance relating to
length.
[0079] The present invention is not limited to the exemplary
embodiments set forth hereinabove, and a person skilled in the art
may easily make modifications to o the exemplary embodiments set
forth hereinabove, within the technical scope encompassed by the
claims.
REFERENCE SIGNS LIST
[0080] O: origin [0081] 1: plating device [0082] 2: plating fluid
[0083] 3: plating tank [0084] 5: shaft-shaped member [0085] 5c:
center position of plated portion [0086] 5l: length of plated
portion [0087] 5s: plated portion [0088] 6: rotary means [0089] 9:
plating fluid spray nozzle [0090] 9b, 9f: plating fluid spray
nozzle fasteners [0091] 10: positive electrode [0092] 10b, 10n,
10f1: shield fasteners [0093] 10c: center position of output
portion [0094] 10l: length of output portion [0095] 10f2: metal
cage fastener [0096] 10m: shield [0097] 10s: output portion [0098]
13, 15: shield jigs at either end [0099] 14: shield jig situated
between shield jigs at either end [0100] 26: plating fluid spray
orifices [0101] 26c center position of plating fluid spray orifice
[0102] 27 metal cage [0103] 28 metal pellets
* * * * *