U.S. patent application number 12/249412 was filed with the patent office on 2009-02-12 for filter apparatus and frequency coverter to which the filter apparatus is connected.
Invention is credited to Masahiro Hiraga, Masayuki Hirota, Satoshi Ibori, Naoki Takata.
Application Number | 20090040743 12/249412 |
Document ID | / |
Family ID | 34431483 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090040743 |
Kind Code |
A1 |
Hirota; Masayuki ; et
al. |
February 12, 2009 |
FILTER APPARATUS AND FREQUENCY COVERTER TO WHICH THE FILTER
APPARATUS IS CONNECTED
Abstract
A power converter connected to a wiring drawing portion of a
frequency converter, said filter apparatus including: a condenser
element having an electronic part having an insulator as a
dielectric material held between conductor plates; a sealing agent
sealing said condenser element; a filter circuit comprising said
condenser element; a connection conductor establishing wiring
connections of said filter circuit; and a filter housing supporting
said sealing agent.
Inventors: |
Hirota; Masayuki;
(Narashino, JP) ; Ibori; Satoshi; (Yatimata,
JP) ; Takata; Naoki; (Narashino, JP) ; Hiraga;
Masahiro; (Yotsukaidou, JP) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET, SUITE 1800
ARLINGTON
VA
22209-3873
US
|
Family ID: |
34431483 |
Appl. No.: |
12/249412 |
Filed: |
October 10, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10985943 |
Nov 12, 2004 |
|
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|
12249412 |
|
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Current U.S.
Class: |
361/818 |
Current CPC
Class: |
H02M 1/44 20130101; H02M
7/003 20130101; H05K 7/1432 20130101 |
Class at
Publication: |
361/818 |
International
Class: |
H05K 9/00 20060101
H05K009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 14, 2003 |
JP |
2003-384487 |
Claims
1. A power converter connected to a wiring drawing portion of a
frequency converter, said filter apparatus comprising: a condenser
element having an electronic part having an insulator as a
dielectric material held between conductor plates; a sealing agent
sealing said condenser element; a filter circuit comprising said
condenser element; a connection conductor establishing wiring
connections of said filter circuit; and a filter housing supporting
said sealing agent; wherein said filter apparatus is fixed to said
frequency converter based on a positioning portion provided in part
of the housing of said frequency converter.
2. The power converter according to claim 1, wherein the raised
portion provided in said filter apparatus is interlocked with a
hole-like positioning portion provided in part of the housing of
said frequency converter to position said filter apparatus in said
frequency converter.
3. The power converter according to claim 1, wherein said filter
apparatus is abutted against a step-like positioning portion
provided in part of the housing of said frequency converter to
position said filter apparatus in said frequency converter.
4. The power converter according to claim 1, wherein an adhesive is
used to fix said filter apparatus to the housing of said frequency
converter.
5. The power converter according to claim 1, wherein a screw is
used to fix said filter apparatus to the housing of said frequency
converter.
6. The power converter according to claim 1, wherein a
Hook-and-Loop is used to fix said filter apparatus to the housing
of said frequency converter.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. application Ser. No.
10/985,943, filed Nov. 12, 2004. This application relates to and
claims priority from Japanese Patent Application No. 2003-384487,
filed on Nov. 14, 2003. The entirety of the contents and subject
matter of all of the above is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a technique for reducing
noises of a frequency converter supplying electric power to, for
example, a motor.
PRIOR ART
[0003] For specifications regarding electromagnetic noises in the
frequency converter, performance characteristics for which the CE
mark can be labeled, EN55011 (Class A, Class B) and EN61800 are
known. The specifications and the like are described for specifying
limit values of electromagnetic noises according to apparatuses
used and classes of use environments to prevent influences on other
electrical apparatuses.
[0004] Techniques regarding measures against noises as described
above include, for example, the technique disclosed in Patent
Document 1.
[0005] [Patent Document 1] JP-A-8-308250
[0006] In measures against noises, a filter apparatus reducing
electromagnetic noises and the like is generally provided. However,
if the filter apparatus is provided, a mounting space is required
accordingly, and the drawing of wiring and the like for connecting
the filter apparatus should be considered.
[0007] In view of the matters described above, the object of the
present invention is to provide a filter apparatus reducing
electromagnetic noises and the like for a frequency converter
supplying electric power to, for example, a motor, and to realize a
downsizing and the like of the frequency converter or filter
apparatus while connecting the filter apparatus to the frequency
converter.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention solves the above problem as follows. A
filter apparatus reducing electromagnetic noises and the like is
provided near a wiring drawing portion of a main circuit terminal
board of a frequency converter.
[0009] The filter apparatus is connected to the wiring drawing
portion of the main circuit terminal board.
[0010] Part of a housing of the frequency converter and part of a
filter housing are fitted to each other to fix the filter housing
on the frequency converter.
[0011] Characteristics of the filter apparatus may be defined as
not having influences such as electromagnetic noises on other
electric apparatuses based on performance characteristics for which
the CE mark can be labeled, EN55011 and the specification of
EN61800, for example.
[0012] Particularly, the specification of EN61800 and EN55011
(Class A, Class B) included in the specification of EN 61800 are
generally well known in the frequency converter and the like.
[0013] Thus, as a filter apparatus reducing electromagnetic noises
and the like, the filter apparatus may be configured to have
characteristics of filter apparatus based on the specification of
EN61800 and EN55011 (Class A, Class B) included in the
specification of EN61800.
[0014] According to the present invention, a product having good
characteristics can be provided as to reduction of noises of the
frequency converter. Alternatively, a frequency converter having a
reduced size while achieving a reduction in noises can be
provided.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] FIG. 1 shows an example of a frequency converter having an
electromagnetic noise filter mounted thereon;
[0016] FIG. 2 shows another example of the frequency converter
having the electromagnetic noise filter mounted thereon;
[0017] FIG. 3 shows Example of the present invention (plan
view);
[0018] FIG. 4 shows Example of a waterproof case of a digital
operator;
[0019] FIG. 5 shows Example of the electromagnetic noise filter
(sectional view);
[0020] FIG. 6 shows Example of the electromagnetic noise filter
(another sectional view); and
[0021] FIG. 7 shows an example of another method for mounting the
electromagnetic noise filter.
DETAILED DESCRIPTION OF THE INVENTION
[0022] An electromagnetic noise filter as a filter apparatus
reducing electromagnetic noises in Example according to the present
invention, or a frequency converter to which the filter apparatus
is connected will be described in detail below using Example shown
in figures.
[0023] FIG. 1 shows an implementation of the electromagnetic noise
filter as Example according to the present invention. In the
figure, reference numeral 1 denotes a frequency converter housing,
reference numeral 2 denotes an electromagnetic noise filter case,
reference numeral 3 denotes a terminal board cover, reference
numeral 4 denotes a wiring drawing plate, and reference numeral 5
denotes an earth bar for frequency converters. The frequency
converter housing 1 is provided with a groove 6 for mounting the
wiring drawing plate 4, and the wiring drawing plate 4 is provided
with a raised portion 7. The electromagnetic noise filter case 2 is
also provided with the raised portion 7. If no filter is required,
the electromagnetic noise filter case 2 can be removed to fit the
wiring drawing plate 4 directly into the groove 6 provided in a
case of the frequency converter 1.
[0024] Attachment/detachment can be eased by providing a raised
portion 22 on the side face of the electromagnetic noise filter
case 2 and providing a recessed portion 21 on the side face of the
frequency converter housing 1 as shown in FIG. 7. The recessed
portion 21 is a hole-like portion provided on the side face of the
frequency converter housing 1, and the raised portion 22 is a
protruding portion provided on the side face of the electromagnetic
noise filter case 2. The recessed portion 21 and the raised portion
22 are fitted to or engaged with each other to fix the
electromagnetic noise filter case 2 to the frequency converter
housing 1.
[0025] In the configuration shown in FIG. 1, the frequency
converter housing 1 and the filter housing of the electromagnetic
noise filter case 2 are fitted to each other to fix the
electromagnetic noise filter to the frequency converter. For this
purpose, a fitting portion fitting part of the frequency converter
housing 1 and the filter housing of the electromagnetic noise
filter case 2 to each other is provided in each housing.
[0026] In FIG. 1, the recessed groove 6 for mounting the wiring
drawing plate 4 in the frequency converter housing 1 or the raised
portion 7 in the electromagnetic noise filter case 2 is the fitting
portion. However, the fitting portion is not limited to the
specific shape of the recessed groove 6 or raised portion 7, but
may have any different shape as appropriate as long as it allows
the frequency converter housing 1 to be fixed to the filter housing
of the electromagnetic noise filter case 2.
[0027] Example of fixation by fitting has been described above, but
fixation is not limited thereto, and part of the frequency
converter housing 1 and part of the filter housing of the
electromagnetic noise filter case 2 may be interlocked or engaged
with each other for fixation. In this case, an interlocking portion
interlocked with part of each housing or an engagement portion
engaging parts of the housings with each other is provided.
[0028] If a filter having better characteristics or a filter having
a larger size is required for making the filter compliant with a
higher specification in terms of the specification, the attached
filter can be removed to attach a filter for the specification with
ease in the manner described above.
[0029] Alternatively, a noise filter effect can be increased by
coupling together electromagnetic noise filter cases 2 having the
same shape as shown in FIG. 2. In this case, the fitting portion
composed of the recessed portion 21 and the raised portion 22 is
provided in the electromagnetic noise filter case 2, thus making it
possible to couple together electromagnetic noise filter cases 2 at
the fitting portion composed of the recessed portion 21 and the
raised portion 22.
[0030] The coupled noise filter cases may be different in size,
thickness, characteristics of filters, contained condensers,
electronic parts constituting the filter, and the like. However, by
equalizing the outer dimensions of electromagnetic noise filter
cases, the overall dimensional and the like as the frequency
converter can be approximately estimated to afford convenience
during installation in equipment as a matter of course.
[0031] A fixing screw for installing the electromagnetic noise
filter is not required because the groove 6 provided originally for
use in the frequency converter is used, and thus the need for
screws can be eliminated for fixation.
[0032] However, for fixing the electromagnetic noise filter case 2
to the frequency converter housing 1, a screw may be used, or an
adhesive or Hook-and-Loop fastener (detachable plane fastener with
a hook shape and a pile shape interlocked) may be used.
[0033] In this case, positioning for positioning the
electromagnetic noise filter case 2 at a predetermined location in
the frequency converter housing 1 can be considered. For example, a
positioning portion is provided in part of the frequency converter
housing 1, and the electromagnetic noise filter case 2 is
positioned based on the positioning portion and is then fixed with
the screw or the like, whereby efficiency of fixation work and the
like can be improved.
[0034] For the positioning portion, a portion such as the recessed
portion 21 or raised portion 22 described with FIG. 2 may be used
as a positioning portion. Alternatively, positioning may be done by
protruding a heat dissipation fin 30 shown in FIG. 7 by a
predetermined length relative to the frequency converter housing 1
and abutting part of the electromagnetic noise filter case 2
against the protruding portion. Of course, positioning may be done
by providing a protruding portion in part of the frequency
converter housing 1 and abutting part of the electromagnetic noise
filter case 2 against the protruding portion.
[0035] The location in the frequency converter housing 1 at which
the electromagnetic noise filter case 2 is mounted, shown in FIG.
1, is a location at which a space must be usually provided for
wiring to the frequency converter such as main circuit wiring. For
this reason, it is not required to provide a space for mounting the
electromagnetic noise filter case in the frequency converter
housing 1.
[0036] Thus, the frequency converter housing 1 is never upsized
even if the electromagnetic noise filter case is mounted. The shape
of the frequency converter housing 1 should not be changed between
a type of frequency converter in which the electromagnetic noise
filter case is mounted and a type of frequency converter in which
electromagnetic noise filter case is not mounted. That is,
regardless of whether the electromagnetic noise filter case is
mounted or not, the shape of the frequency converter housing 1 can
be equalized. This contributes to reduction in costs for moldings
that are used during production of the frequency converter housing
1, and the like.
[0037] A view seen from the top is shown in FIG. 3. From the
electromagnetic noise filter case 2, terminals 8, 9 and 10 are
connected to input terminals R, S and T, respectively. The
terminals 8, 9 and 10 are made of conductive materials such as
metals such as copper, aluminum and copper-nickel alloys.
[0038] The terminals 8, 9 and 10 are made of thin metal and
therefore, even if a slight difference in height occurs during
connection to a terminal board provided in the frequency converter
1, the material is warped and deformed to make connection easy. The
terminals 8, 9 and 10 are conductive plates in the figure, but the
same effect can be obtained if they are wire rods.
[0039] A sectional view of the electromagnetic noise filter case is
shown in FIG. 6. Another sectional view of the electromagnetic
noise filter case is shown in FIG. 7. Inside the electromagnetic
noise filter case 2, a filter condenser 11 is placed and walls 12
and 13 for partitioning the filter condenser 11 are provided. The
filter condenser 11 is usually covered with a resin 23 of plastic
as a sealing agent for ensuring improvement in moisture resistance
and heat resistance and an insulation distance specified in the
specification, and is thus unseen after assembly.
[0040] Usually, the filter condenser 11 that is used in Example
does not have a case that is provided when the condenser is formed.
A usual condenser has electronic parts composed of metal plates and
an insulator or the like as a dielectric material held between the
metal plates covered with a condenser case. In Example, the
electronic part composed of metal plates and an insulator or the
like as a dielectric material held between the metal plates is
placed directly in the noise filter case 2 and covered with the
resin 23 of plastic. With this configuration, the filter can be
downsized and lightened as a whole because the usual condenser is
absent.
[0041] A groove 15 through which an earth bar 14 for filter
condenser connected to the earth bar 5 for frequency converter
passes. The wall 13 provided near the groove 15 is made to be
little taller than the wall 12 partitioning the condenser 11,
whereby the resin of plastic is prevented from flowing into the
groove 15 even if a low-viscosity plastic resin is used when the
filter condenser 11 is covered with the resin 23 of plastic. As a
result, even if a low-viscosity resin not requiring a degassing
apparatus or the like is used, the plastic resin is never leaked
from the groove into which the earth bar 14 being a connection
conductor on the ground side is fitted, and thus workability is
improved.
[0042] When a high-viscosity plastic resin is used, the groove 15
is made to have an appropriate size, whereby the plastic resin used
for sealing the filter condenser 11 is never leaked from the groove
15 owing to the viscosity of the plastic resin, thus making it
possible to eliminate the need for the wall 13.
[0043] The earth bar 5 for frequency converter and the earth bar 14
for filter condenser are connected directly on the undersurface of
the electromagnetic noise filter case 2, or connected through a
conductor plate or wire rod. As in the connection form described
above, the connection conductor on the ground side of the
electromagnetic noise filter case 2 should be connected to the
connection conductor on the installation side of the frequency
converter at a shortest possible distance.
[0044] The conductor plate 20 grounding the filter condenser 11 on
the ground side inside the electromagnetic noise filter case 2 is
placed along the inner wall of the electromagnetic noise filter
case 2, whereby electromagnetic noises generated in the
electromagnetic noise filter case 2 can be blocked.
[0045] A volume control knob 17 placed in the frequency converter 1
and provided in a digital operator 16 can easily be attached and
detached.
[0046] The digital operator 16 is held between a waterproof cover
19 and a waterproof case 18 as shown in FIG. 4, whereby waterproof
measures can be made.
[0047] The filter apparatus and the frequency converter in the
Example described above may be, for example, distributed, sold, and
transferred in the market and the like with each of them as a
single product. Alternatively, they may be, for example,
distributed, sold and transferred in the market and the like as the
frequency converter with the filter apparatus connected thereto,
i.e. in an integrated state.
[0048] For a condenser element that is used in the filter apparatus
in the Example described above, a condenser element having an
electronic part having an insulator as a dielectric material held
between conductor plates can be used.
[0049] Characteristics of the filter apparatus may be defined as
not having influences such as electromagnetic noises on other
electrical apparatuses and the like based on, for example, the CE
specification, EN55011 and the specification of EN61800.
[0050] It should be further understood by those skilled in the art
that although the foregoing description has been made on
embodiments of the invention, the invention is not limited thereto
and various changes and modifications may be made without departing
from the spirit of the invention and the scope of the appended
claims.
* * * * *