U.S. patent application number 10/960659 was filed with the patent office on 2005-05-26 for method of producing iron core and apparatus for producing iron core.
This patent application is currently assigned to Mitsui High-tec, Inc.. Invention is credited to Oba, Yukinori, Shimizu, Takahiro.
Application Number | 20050109178 10/960659 |
Document ID | / |
Family ID | 34543289 |
Filed Date | 2005-05-26 |
United States Patent
Application |
20050109178 |
Kind Code |
A1 |
Oba, Yukinori ; et
al. |
May 26, 2005 |
Method of producing iron core and apparatus for producing iron
core
Abstract
An iron core-producing method of the invention includes at least
the step of blanking an iron core T from a strip W in such a manner
that a longitudinal direction of the substantially linear iron core
T is inclined relative to a direction of a width of the strip W. An
iron core-producing apparatus of the invention for blanking a
substantially linear iron core T from a strip W includes at least a
punch disposed such that its longitudinal direction is inclined
relative to a direction of a width of the strip W, and a die 13
which is provided beneath the punch, and is disposed such that its
longitudinal direction is inclined relative to the direction of the
width of the strip W.
Inventors: |
Oba, Yukinori; (Fukuoka,
JP) ; Shimizu, Takahiro; (Fukuoka, JP) |
Correspondence
Address: |
WOOD, PHILLIPS, KATZ, CLARK & MORTIMER
500 W. MADISON STREET
SUITE 3800
CHICAGO
IL
60661
US
|
Assignee: |
Mitsui High-tec, Inc.
|
Family ID: |
34543289 |
Appl. No.: |
10/960659 |
Filed: |
October 7, 2004 |
Current U.S.
Class: |
83/50 ;
83/687 |
Current CPC
Class: |
Y10T 83/9425 20150401;
B21D 28/02 20130101; Y10T 29/49009 20150115; B21D 28/06 20130101;
Y10T 83/0577 20150401; Y10T 83/06 20150401; Y10T 83/0448 20150401;
Y10T 83/943 20150401; H02K 15/02 20130101; Y10T 83/0481
20150401 |
Class at
Publication: |
083/050 ;
083/687 |
International
Class: |
B26F 001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2003 |
JP |
P. 2003-352313 |
Claims
What is claimed is:
1. An iron core-producing method for blanking a substantially
linear iron core from a strip, comprising the step of: blanking the
iron core from the strip in such a manner that a longitudinal
direction of the iron core is inclined relative to a direction of a
width of the strip.
2. The method as claimed in claim 1, further including the step of
changing an angle of inclination of the iron core relative to the
direction of the width of the strip in accordance with a length of
iron cores to be produced.
3. An iron core-producing apparatus for blanking a substantially
linear iron core from a strip, comprising: a punch disposed such
that its longitudinal direction is inclined relative to a direction
of a width of the strip; and a die which is provided beneath said
punch, and is disposed such that its longitudinal direction is
inclined relative to the direction of the width of the strip.
4. The apparatus as claimed in claim 3, further including means for
changing an angle of inclination of the punch and the die in
accordance with a length Y of iron cores to be produced.
5. The apparatus as claimed in claim 3, further comprising another
set of the punch and the die, so that the punched cores are mated
with each other.
6. The method as claimed in claim 1, wherein an angle of the
inclination of the iron core is set in a range from 20.degree. to
70.degree..
7. The apparatus as claimed in claim 3, wherein an angle of the
inclination of the punch and the die is set in a range from
20.degree. to 70.degree..
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a method of and an apparatus for
producing an iron core.
[0002] An iron core for a motor is formed from a strip by blanking.
This iron core is usually blanked as a substantially linear iron
core.
[0003] This linear iron core comprises a plurality of magnetic pole
pieces which are interconnected into a linear configuration by
interconnecting portions, each magnetic pole piece comprising a
yoke portion, and a tooth portion.
[0004] A plurality of such iron cores are stacked and laminated
together, and thereafter windings are wound around the stacks of
tooth portions, respectively, and the interconnecting portions are
bent so as to form the laminated iron core assembly into an annular
shape, thereby producing a core (stator) of a motor (see, for
example, JP-A-11-156455).
[0005] For producing the above substantially-linear iron core,
there is conventionally used an iron core-producing apparatus which
comprises guide means for guiding the strip linearly in one
direction, a punch for blanking an iron core from the strip, and a
die located beneath the punch.
[0006] In such a conventional producing apparatus, when the strip
is guided onto the die by the guide means, the punch is driven into
the die, thereby blanking an iron core from the strip.
[0007] In this conventional producing apparatus, the punch and the
die are disposed such that their longitudinal direction is parallel
to the direction of the width of the strip. Therefore, in the
blanking step, the iron core is blanked from the strip in such a
manner that the longitudinal direction of the iron core is disposed
parallel to the direction of the width of the strip (see, for
example, JP-A-11-156455).
[0008] In the production of the conventional iron core, the iron
core is blanked, with its longitudinal direction disposed parallel
to the direction of the width of the strip, and therefore in order
to increase the overall length of the iron core, it has been
necessary to increase the width of the strip.
[0009] And besides, in the conventional iron core-producing
apparatus, the punch and the die are disposed in such a manner that
their longitudinal direction is parallel to the direction of the
width of the strip as described above. Therefore, when the width of
the strip is increased in order to increase the overall length of
the iron core, a strip conveyance width of the guide means must be
increased in accordance with the increased width of the strip;
otherwise, the iron core can not be conveyed, and therefore can not
be produced. In addition, unless a longitudinal width of a blanking
drop hole, formed in the die, is increased according to the width
of the strip, the iron core can not be produced from the strip by
blanking.
[0010] In order to thus increase the overall length of the iron
core, there have been encountered problems that the width of the
strip must be increased and that the whole of the iron
core-producing apparatus becomes large in size.
[0011] When the whole of the iron core-producing apparatus becomes
large in size, it is required to use a pressing device of a large
size, which has been very disadvantageous.
SUMMARY OF THE INVENTION
[0012] In view of the above circumstances, it is an object of this
invention to provide an iron core-producing method and an iron
core-producing apparatus which are capable of producing an iron
core of a large overall length without the need for increasing a
width of a strip and without the use of an iron core-producing
apparatus of a large size.
[0013] The above object has been achieved by an iron core-producing
method of the invention for blanking a substantially linear iron
core from a strip, comprising at least the step of blanking the
iron core from the strip in such a manner that a longitudinal
direction of the iron core is inclined relative to a direction of a
width of the strip.
[0014] An iron core-producing apparatus of the invention for
blanking a substantially linear iron core from a strip, comprises
at least a punch disposed such that its longitudinal direction is
inclined relative to a direction of a width of the strip, and a die
which is provided beneath the punch, and is disposed such that its
longitudinal direction is inclined relative to the direction of the
width of the strip.
[0015] The iron core-producing method of the invention comprises at
least the step of blanking the iron core from the strip in such a
manner that the longitudinal direction of the substantially linear
iron core is inclined relative to the direction of the width of the
strip. Therefore, the iron core, having an overall length larger
than the width of the strip, can be produced without the need for
increasing the width of the strip. And besides, when producing this
iron core, it is not necessary to use a large-size producing
apparatus since the width of the strip is not increased.
[0016] The iron core-producing apparatus of the invention is
designed to blank the substantially linear iron core from the
strip, and comprises at least the punch disposed such that its
longitudinal direction is inclined relative to the direction of the
width of the strip, and the die which is provided beneath the
punch, and is disposed such that its longitudinal direction is
inclined relative to the direction of the width of the strip.
Therefore, the iron core, having an overall length larger than the
width of the strip, can be produced without the need for increasing
the width of the strip. And besides, when producing this iron core,
it is not necessary to use a large-size producing apparatus since
the width of the strip is not increased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a conceptual top plan view of an iron
core-producing apparatus of the present invention.
[0018] FIG. 2 is a conceptual top plan view of a strip W used in
the producing apparatus of FIG. 1.
[0019] FIG. 3 is a conceptual top plan view of an iron core T
produced at Station S2 of the producing apparatus of FIG. 1.
[0020] FIG. 4 is a conceptual top plan view showing the strip W in
which a plurality of caulking portions L1 and a plurality of
caulking portions L2 are formed by stamping at Station S1 of the
producing apparatus of FIG. 1.
[0021] FIG. 5 is a conceptual top plan view of the strip W from
which the iron core T has been blanked from the strip W at Station
S2 of the producing apparatus.
[0022] FIG. 6 is a conceptual top plan view of the strip W, showing
a condition in which caulking portions L1 and caulking portions L2
have been formed by stamping in the strip W of FIG. 5 at Station
S3.
[0023] FIG. 7 is a conceptual top plan view of an iron core T
produced at Station S4 of the producing apparatus of FIG. 1.
[0024] FIG. 8 is a conceptual top plan view of the strip W of FIG.
6 from which the iron core T of FIG. 7 has been blanked.
[0025] FIG. 9 is a conceptual top plan view of the strip W to which
the process of Stations S1 to S4 has been repeatedly applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] One preferred embodiment of the present invention will now
be described in detail with reference to the drawings.
[0027] FIG. 1 is a conceptual top plan view of an iron
core-producing apparatus (hereinafter referred to merely as
"producing apparatus") of the invention. FIG. 2 is a conceptual top
plan view of a strip W used in the producing apparatus of FIG. 1.
FIG. 3 is a conceptual top plan view of an iron core T produced at
Station S2 (described later) of the producing apparatus of FIG.
1.
[0028] The iron core-producing apparatus 1 of FIG. 1 forms the
substantially linear iron core T of FIG. 3 from the strip W of FIG.
2 by blanking.
[0029] As shown in FIG. 3, the iron core T thus blanked from the
strip W includes a plurality of magnetic pole pieces interconnected
by interconnecting portions Tc, each of the magnetic pole pieces
comprising a yoke portion Ta, and a tooth portion Tb formed on and
projecting from the yoke portion Ta.
[0030] The iron cores T are sequentially stacked one upon another
and bound together by caulking in such a manner that caulking
portions, formed in the magnetic pole pieces of each iron core T,
are fitted respectively in the caulking portions of the preceding
iron core T in the step of blanking the iron core T. Windings are
wound respectively around the stacks of tooth portions Tb of the
multiplicity of laminated iron cores T, and the interconnecting
portions Tc are bent so as to form the laminated iron cores T into
an annular shape, thereby producing a core of a motor.
[0031] The producing apparatus 1 of FIG. 1 is provided with guide
means (not shown) for guiding the strip W in a longitudinal
direction thereof.
[0032] This guide means includes engagement projections (not shown)
for engagement in pilot holes P formed at a predetermined pitch in
opposite side edge portions (spaced from each other in the
direction of the width) of the strip W (FIG. 2). A leading end
portion of the strip W is taken up through the engagement of the
engagement projections in the pilot holes P, so that the strip W is
guided sequentially to Stations S1 to S4.
[0033] The strip W is sequentially processed at Stations S1 to
S4.
[0034] At Station S1, the caulking portions L1 and the caulking
portions L2 (FIG. 4) are formed in the strip W.
[0035] Caulking portion-forming holes 11 for simultaneously forming
the caulking portions L1 and the caulking portions L2 in the iron
core T are provided at Station S1. A longitudinal direction of rows
of caulking portion-forming holes 11 is inclined at an angle A
(described later) relative to the direction X of the width of the
strip W.
[0036] At Station S2, the iron core T (serving as a product) is
formed from the strip W by blanking.
[0037] A die 13 and a die holder 14 for fixing the die 13 are
provided at Station S2.
[0038] A blanking drop hole 13a is formed in the die 13, and
extends in a longitudinal direction thereof. A longitudinal
direction of the blanking drop hole 13a is inclined at the angle A
relative to the widthwise direction X of the strip W.
[0039] A product take-out device 21 is provided below the blanking
drop hole 13a. This product take-out device 21 comprises a conveyor
belt (not shown) whose longitudinal direction is inclined relative
to the widthwise direction of the strip W.
[0040] At Station S2, the iron core T is blanked in such a manner
that the tooth portions Tb of the iron core T are disposed at lower
sides of the respective yoke portions Ta as shown in FIG. 3.
[0041] At Station S3 of FIG. 1, caulking portions L1 and caulking
portions L2 (as shown in FIG. 6) are formed in the strip W (from
which the iron core T has been blanked at Stations S1 and S2) in
order to produce another (fresh) iron core T.
[0042] Caulking portion-forming holes 16 for simultaneously forming
the caulking portions L1 and the caulking portions L2 are provided
at this Station S3. A longitudinal direction of rows of caulking
portion-forming holes 16 is inclined at the angle A relative to the
widthwise direction X of the strip W.
[0043] The caulking portions L1 and L2, which are identical in
configuration to the caulking portions L1 and L2 formed at Station
S1, are formed by stamping at this Station S3. However, as shown in
FIG. 6, the positions of the caulking portions L1 and L2 (formed at
Station S3) relative to each other are reversed (inverted) with
respect to the caulking portions L1 and L2 formed at Station
S1.
[0044] At Station S4 of FIG. 1, the fresh iron core T (serving as a
product) is blanked from the strip W in which the caulking portions
L1 and L2 have been formed at Station S3.
[0045] A die 18 and a die holder 19 for fixing the die 18 are
provided at this Station S4.
[0046] A blanking drop hole 18a is formed in the die 18, and
extends in a longitudinal direction thereof. A longitudinal
direction of the blanking drop hole 18a is inclined at the angle A
relative to the widthwise direction X of the strip W.
[0047] A product take-out device 22 is provided below the blanking
drop hole 18a. This product take-out device 22 comprises a conveyor
belt (not shown) whose longitudinal direction is inclined relative
to the widthwise direction of the strip W.
[0048] The iron core T, formed by blanking at Station S4, is
identical in configuration to the iron core T formed by blanking at
Station S2. However, at Station S4, the iron core T is blanked in
such a manner that the tooth portions Tb of this iron core T are
disposed at upper sides of the respective yoke portions Ta as shown
in FIG. 7 (described later).
[0049] The process of producing the iron cores T from the strip W
by the use of the above producing apparatus 1 will be described
below in detail with reference to FIGS. 1 to 9.
[0050] At Station S1 of FIG. 1, when the strip W of FIG. 2 is
guided by the guide means to a position above the caulking
portion-forming holes 11, a punch (not shown) intrudes into the
caulking portion-forming holes 11 to simultaneously form the
plurality of caulking portions L1 and the plurality of caulking
portions L2 (FIG. 3) at a predetermined pitch as shown in FIG.
4.
[0051] FIG. 4 is a conceptual top plan view showing the strip W in
which the plurality of caulking portions L1 and the plurality of
caulking portions L2 are thus formed.
[0052] The caulking portions L1 as well as the caulking portions
L2, formed in the strip W, correspond in number to the magnetic
pole pieces of the iron core T (FIG. 3).
[0053] The row of caulking portions L1 as well as the row of
caulking portions L2, are formed to be disposed in a direction
inclined at the angle A (.noteq.90.degree.) relative to the
widthwise direction of the strip W. It will be appreciated also
from the arrangement of the thus formed caulking portions L1 and L2
that the longitudinal direction of the rows of caulking
portion-forming holes 11, as well as the longitudinal direction of
the punch for intruding into these holes 11, is inclined at the
angle A (.noteq.90.degree.) relative to the widthwise direction of
the strip W.
[0054] At Station S1, thus, the caulking portion-forming holes 11
and the punch for intruding into these holes 11 are so arranged
that the longitudinal direction of the rows of caulking
portion-forming holes 11, as well as the longitudinal direction of
the punch for intruding into these holes 11, is inclined at the
angle A (.noteq.90.degree.) relative to the widthwise direction of
the strip W. Therefore, a longitudinal width M (see FIG. 4) of the
rows of caulking portion-forming holes 11, as well as a
longitudinal width M (see FIG. 4) of the punch for intruding into
these holes 11, can be made larger than the width X of the strip W.
Therefore, a distance M between the two caulking portions L1
disposed respectively at the opposite ends of the row of caulking
portions L1, as well as a distance M between the two caulking
portions L2 disposed respectively at the opposite ends of the row
of caulking portions L2, can be made larger than the width X of the
strip W (M>X) as shown in FIG. 4.
[0055] Then, at Station S2 of FIG. 1, when the strip W is conveyed
to a position above the blanking drop hole 13a in the die 13, a
punch (not shown) intrudes into the blanking drop hole 13a to blank
the iron core T of FIG. 3 from the strip W of FIG. 4. FIG. 5 is a
conceptual top plan view of the strip W from which the iron core T
of FIG. 3 has been blanked.
[0056] As shown in FIG. 3, the caulking portion L1 and the caulking
portion L2 have been formed in each of the magnetic pole portions
of the thus blanked iron core T.
[0057] On the other hand, a blanked-out hole C is formed in the
strip W as a result of blanking of the iron core T as shown in FIG.
5. A longitudinal direction of the thus formed blanked-out hole C
is inclined at the angle A (.noteq.90.degree.) relative to the
widthwise direction of the strip W. It will be appreciated also
from the manner of formation of this blanked-out hole C that the
longitudinal direction of the blanking drop hole 13a, as well as
the longitudinal direction of the punch for intruding into this
hole 13a, is inclined at the angle A (.noteq.90.degree.) relative
to the widthwise direction of the strip W.
[0058] At this Station S2, thus, the blanking drop hole 13a and the
punch for intruding into this hole 13a are so arranged that the
longitudinal direction of the, blanking drop hole 13a, as well as
the longitudinal direction of the punch for intruding into this
hole 13a, is inclined at the angle A (.noteq.90.degree.) relative
to the widthwise direction of the strip W. Therefore, a
longitudinal width Y of the blanking drop hole 13a, as well as a
longitudinal width Y of the punch for intruding into this hole 13a,
can be made larger than the width X of the strip W (Y>X).
Therefore, the overall length Y (see FIG. 3) of the blanked iron
core T can be made larger than the width X of the strip W
(Y>X).
[0059] At Station S3 of FIG. 1, when the strip W of FIG. 5 is
guided by the guide means to a position above the caulking
portion-forming holes 16, a punch (not shown) intrudes into the
caulking portion-forming holes 16 to simultaneously form the
caulking portions L1 and the caulking portions L2 as shown in FIG.
6.
[0060] FIG. 6 is a conceptual top plan view of the strip W, showing
a condition in which the caulking portions L1 and the caulking
portions L2 have been formed by stamping in the strip W of FIG. 5
at Station S3.
[0061] The caulking portions L1 as well as the caulking portions
L2, formed in the strip W, correspond in number to the magnetic
pole pieces of the iron core T (FIG. 7).
[0062] The row of caulking portions L1 as well as the row of
caulking portions L2, are formed to be disposed in a direction
inclined at the angle A (.noteq.90.degree.) relative to the
widthwise direction of the strip W. It will be appreciated also
from the arrangement of the thus formed caulking portions L1 and L2
that the longitudinal direction of the rows of caulking
portion-forming holes 16, as well as the longitudinal direction of
the punch for intruding into these holes 16, is inclined at the
angle A (.noteq.90.degree.) relative to the widthwise direction of
the strip W.
[0063] At Station S3, thus, the caulking portion-forming holes 16
and the, punch for intruding into these holes 16 are so arranged
that the longitudinal direction of the rows of caulking
portion-forming holes 16, as well as the longitudinal direction of
the punch for intruding into these holes 16, is inclined at the
angle A (.noteq.90.degree.) relative to the widthwise direction of
the strip W. Therefore, a longitudinal width M (see FIG. 4) of the
rows of caulking portion-forming holes 16, as well as a
longitudinal width M of the punch for intruding into these holes
16, can be made larger than the width X of the strip W. Therefore,
a distance M (see FIG. 4) between the two caulking portions L1
disposed respectively at the opposite ends of the row of caulking
portions L1, as well as a distance M (see FIG. 4) between the two
caulking portions L2 disposed respectively at the opposite ends of
the row of caulking portions L2, can be made larger than the width
X of the strip W (M>X).
[0064] Then, at Station S4 of FIG. 1, when the strip W of FIG. 6 is
conveyed to a position above the blanking drop hole 18a in the die
18, a punch (not shown) intrudes into the blanking drop hole 18a to
blank the iron core T from the strip W of FIG. 6 as shown in FIG.
7. FIG. 7 is a conceptual top plan view of the iron core T formed
at this Station S4. FIG. 8 is a conceptual top plan view of the
strip W from which the iron core T of FIG. 7 has been blanked.
[0065] As shown in FIG. 7, the caulking portion L1 and the caulking
portion L2 have been formed in each of the magnetic pole portions
of the thus blanked iron core T.
[0066] A blanked-out hole C is formed in the strip W as a result of
blanking of the iron core T as shown in FIG. 8. A longitudinal
direction of the thus formed blanked-out hole C is inclined at the
angle A (.noteq.90.degree.) relative to the widthwise direction of
the strip W. It will be appreciated also from the manner of
formation of this blanked-out hole C that the longitudinal
direction of the blanking drop hole 18a, as well as the
longitudinal direction of the punch for intruding into this hole
18a, is inclined at the angle A (.noteq.90.degree.) relative to the
widthwise direction of the strip W.
[0067] At this Station S4, thus, the blanking drop hole 18a and the
punch for intruding into this hole 18a are so arranged that the
longitudinal direction of the blanking drop hole 18a, as well as
the longitudinal direction of the punch for intruding into this
hole 18a, is inclined at the angle A (.noteq.90.degree.) relative
to the widthwise direction of the strip W. Therefore, a
longitudinal width Y of the blanking drop hole 18a, as well as a
longitudinal width Y of the punch for intruding into this hole 18a,
can be made larger than the width X of the strip W (Y>X).
Therefore, the overall length Y (see FIG. 3) of the blanked iron
core T (FIG. 7) can be made larger than the width X of the strip W
(Y>X).
[0068] Two iron cores T can be produced by effecting the process of
Stations S1 to S4. In this producing apparatus 1, a plurality of
iron cores (two per process) can be produced from the strip W by
repeating the process of Stations S1 to S4. At each of Stations S1
and S3, the caulking portions L1 and L2 are formed in the iron core
T, and through holes are formed as the respective caulking portions
L1 and L2 through the first (lowermost-layer) iron core T, while in
each of the other iron cores T (that is, the second to
uppermost-layer iron cores T), the type of caulking portions (each
of which assumes a caulking recess when viewed from one side of the
iron core, and also assumes a caulking projection when viewed from
the other side thereof) are formed as the respective caulking
portions L1 and L2. At each of Stations S2 and S4, the iron core T
is blanked from the strip, and moves through the blanking drop hole
13a, 18a into a position beneath the blanking drop hole 13a, 18a.
At Station S4 at which an iron core T is first blanked, the iron
core T, blanked at this time, is placed on the precedingly-produced
iron core T, with its caulking projections fitted respectively in
the through holes in the precedingly-produced iron core T, and the
two iron cores T are laminated (stacked) and bound together by
caulking. Thereafter, at each of Stations S2 and S4, a fresh iron
core T is blanked, and is placed on the precedingly-stacked iron
core T, with its caulking projections fitted respectively in the
caulking recesses in this precedingly-stacked iron core T, and the
fresh iron core T is laminated and joined onto the
precedingly-stacked iron core T by caulking. This process is
repeatedly carried out, so that the predetermined number of iron
cores T are blanked, and are laminated and bound together by
caulking.
[0069] FIG. 9 is a conceptual top plan view of the strip W to which
the process of Stations S1 to S4 has been repeatedly applied. As
shown in FIG. 9, a plurality of rows of blanked-out holes C are
formed in the strip W in parallel relation to one another.
[0070] The predetermined number of iron cores T, blanked and
laminated by caulking at Station S2, are located on the product
take-out device 21, and are discharged to the exterior of the
producing apparatus 1 by the conveyor belt of the product take-out
device 21.
[0071] The predetermined number of iron cores T, blanked and
laminated together by caulking at Station S4, are located on the
product take-out device 22, and are discharged to the exterior of
the producing apparatus 1 by the conveyor belt of the product
take-out device 22.
[0072] As described above, the method of the invention for
producing the iron core T includes at least the step of blanking
the substantially linear iron core T from the strip W in such a
manner that the longitudinal direction of the iron core T is
inclined relative to the widthwise direction of the strip W.
Therefore, the iron core T, having the overall length Y larger than
the width X of the strip W, can be produced, using the strip W
having the conventional width X, that is, without the need for
increasing the width X of the strip W.
[0073] In the case of increasing the overall length Y of the iron
core T, the width X of the strip W does not need to be increased,
and therefore it is not necessary that a strip guide width of the
guide means should be increased in accordance with the width X of
the strip W as in the conventional method, and also it is not
necessary that the longitudinal width of the blanking drop holes
13a and 18a should be increased as in the conventional method.
[0074] Namely, when producing the iron core T having the large
overall length, it is not necessary to increase the width W of the
strip W, and therefore it is not necessary to use a large-size
producing apparatus including the guide means with a large strip
conveyance width, and the blanking drop holes with a large
width.
[0075] This producing method can further includes the step of
changing the angle A of inclination of each of the dies 13 and 18
and the angle A of each of the punches (for intruding respectively
into the dies 13 and 18) in accordance with the overall length Y of
iron cores to be produced, and by doing so, various iron cores of
different overall lengths can be produced.
[0076] The producing apparatus 1 of the invention includes at least
the punches each of which is provided for blanking the
substantially linear iron core T from the strip W, and is disposed
such that its longitudinal direction is inclined relative to the
widthwise direction of the strip W as described above, and the dies
13 and 18 which are provided respectively beneath these punches,
and are disposed such that their longitudinal directions are
inclined relative to the widthwise direction of the strip W as
described above. Therefore, the iron core T, having the overall
length Y larger than the width X of the strip W, can be produced,
using the strip W having the conventional width X, that is, without
the need for increasing the width X of the strip W.
[0077] When increasing the overall length Y of the iron core, it is
not necessary to increase the width W of the strip W, and therefore
it is not necessary to use a large-size producing apparatus
including the guide means with a large strip guide width, and the
blanking drop holes 13a and 18a with a large longitudinal width as
in the conventional apparatus.
[0078] Namely, when producing the iron core T with the large
overall length, the width of the strip W does not need to be
increased, and therefore it is not necessary to use such a
large-size producing apparatus.
[0079] According to the present invention, the angle A of the
inclination is set in a range from 20.degree. to 70.degree.,
preferably in a range from 40.degree. to 60.degree.. Because the
length Y of the iron core T can be represented by Y.dbd.X/cos A, it
is understandable that the length Y is lengthened 1.1X to 2.9X,
preferably 1.3X to 2.0X.
[0080] This producing apparatus 1 can further includes means for
changing the angle A of inclination of each of the blanking drop
holes 13a and 18a and the angle A of each of the punches (for
intruding respectively into the blanking drop holes 13a and 18a) in
accordance with the overall length Y of iron cores T to be
produced, and by doing so, various iron cores of different overall
lengths can be produced.
[0081] Although the producing apparatus 1 of the above embodiment
includes Stations S1 and S2 for producing one iron core T, and
Stations S3 and S4 for producing another iron core T, this
producing apparatus of the invention may include at least Stations
S1 and S2 or Stations S3 and S4 for producing one iron core T.
[0082] Although the producing method of the invention produces a
plurality of iron cores T, the invention can be applied to a method
of producing one iron core T.
[0083] Although the above embodiment illustrates the iron core T of
the winding core-type, the producing method and apparatus of the
invention can be effectively applied to the cases where iron cores
of various shapes are formed by blanking.
[0084] As described above, the iron core-producing apparatus of the
invention is effectively used as a producing apparatus for
producing an iron core serving as a part of a motor core and
particularly for producing an iron core with a large overall
length, and the iron core-producing method is effectively used as a
method of producing this iron core.
* * * * *