CA1177628A - Method of making a transformer or like core from amorphous strip metal - Google Patents
Method of making a transformer or like core from amorphous strip metalInfo
- Publication number
- CA1177628A CA1177628A CA000382392A CA382392A CA1177628A CA 1177628 A CA1177628 A CA 1177628A CA 000382392 A CA000382392 A CA 000382392A CA 382392 A CA382392 A CA 382392A CA 1177628 A CA1177628 A CA 1177628A
- Authority
- CA
- Canada
- Prior art keywords
- core
- groups
- strips
- opposite ends
- thereafter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0206—Manufacturing of magnetic cores by mechanical means
- H01F41/0233—Manufacturing of magnetic circuits made from sheets
- H01F41/024—Manufacturing of magnetic circuits made from deformed sheets
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
- Coils Or Transformers For Communication (AREA)
Abstract
Abstract of the Disclosure:
A method of making a magnetic core from amorphous strip material for use in a transformer or like electrical In-duction apparatus is disclosed herein. In accordance with this method, a continuous strip of non-annealed amorphous metal is wound around a mandrel to form an initially round core which is clamped in a predetermined way and cut en-tirely through one transverse section while a rust inhib-iting liquid coolant is applied thereto. This provides a plurality of connected strips which are thereafter separated into a number of groups and assembled together in a pre-determined way to form a substantially oval shaped core.
This latter core is formed into final shape and thereafter annealed and simultaneously subjected to a magnetic field of predetermined strength in preparation for receiving an associated electric coil or coils.
A method of making a magnetic core from amorphous strip material for use in a transformer or like electrical In-duction apparatus is disclosed herein. In accordance with this method, a continuous strip of non-annealed amorphous metal is wound around a mandrel to form an initially round core which is clamped in a predetermined way and cut en-tirely through one transverse section while a rust inhib-iting liquid coolant is applied thereto. This provides a plurality of connected strips which are thereafter separated into a number of groups and assembled together in a pre-determined way to form a substantially oval shaped core.
This latter core is formed into final shape and thereafter annealed and simultaneously subjected to a magnetic field of predetermined strength in preparation for receiving an associated electric coil or coils.
Description
1 17'7628 .
~THOD OF MAKING A TRANSFOR~ER OR LIXE CORE
F~OM AMORPHOUS STRIP METAL
The present invention relates generally to magnetic cores for use in transformers or like electrical induction ap-paratus and more particularly to a specific method of making a magnetic core from amorphous strip metal.
One common way to make a magnetic core for use in an elec-trical apparatus such as a transformer is to use magnetic strip material having a preferred direction of orientation parallel to the longitudinal direction of the material, e.g.
n-amorphous metal material. This material is relatively flexible and easy to form into the ultimate shape of the core, either before or after it is stress relief annealed.
'Therefore, after the core is formed it can be readily-provided with an unconnected joint, for example by cutting entirely through one circumferential section and, because of its flexibility, an associated electrical coil can be easilv assembled around one section merely by opening the joint and inserting the coil therethrough. While this technique is entirely satisfactory when the core is made from non-amor-phous metal strip material, it has not been proved to besatisfactory when forming a core from amorphous strip material. This is because the latter, for example METGLASR
(a registered trademark) strip material manufactured by Allied Chemical Corp., is very thin, very brittle and very hard. Most attempts to make a core conventionally using 1 17'76X8
~THOD OF MAKING A TRANSFOR~ER OR LIXE CORE
F~OM AMORPHOUS STRIP METAL
The present invention relates generally to magnetic cores for use in transformers or like electrical induction ap-paratus and more particularly to a specific method of making a magnetic core from amorphous strip metal.
One common way to make a magnetic core for use in an elec-trical apparatus such as a transformer is to use magnetic strip material having a preferred direction of orientation parallel to the longitudinal direction of the material, e.g.
n-amorphous metal material. This material is relatively flexible and easy to form into the ultimate shape of the core, either before or after it is stress relief annealed.
'Therefore, after the core is formed it can be readily-provided with an unconnected joint, for example by cutting entirely through one circumferential section and, because of its flexibility, an associated electrical coil can be easilv assembled around one section merely by opening the joint and inserting the coil therethrough. While this technique is entirely satisfactory when the core is made from non-amor-phous metal strip material, it has not been proved to besatisfactory when forming a core from amorphous strip material. This is because the latter, for example METGLASR
(a registered trademark) strip material manufactured by Allied Chemical Corp., is very thin, very brittle and very hard. Most attempts to make a core conventionally using 1 17'76X8
-2-this matexial have been unsuccess~ul, m~inly bec~use ~mo~-phous strip metal is difficult to shear without backc~cking along the shear line. ~toreove~ even if this th~n and brittle material could be sheared without cracking, the time S required to make joint cores using the heretofore conVen-tional approach would be increased significantly due bo the thinness of the material. Nevertheless, it is desirable to use amorphous metal to form the core because of the reduced core losses achieved thereby.
In view of the foregoing, it is a main object of the present invention to provide a relatively uncomplicated and eco-no~ical method of making a magnetic core from amorphous strip metal for use in a transformer or like electrical induction apparatus and particularly a method which is reliable in use. As will be described in more detail hereinafter, the method disclosed starts with a continuous strip of non-annealed amorphous metal which is initially wound about a cyclindrical mandrel to form an initially round core and thereafter clamped in a predetermined way and cut entirely through a predetermined transverse section.
This cutting procedure, which requires the application of a rust inhibiting liquid coolant at the cutting section of the core, results in a plurality of unconnected elongated metal strips. The unconnected strips are separated into the number of individual groups which are assembled, one group at a time, into a substantially oval shaped core and then formed into its final shape, if not already in its final shape. Thereafter, the core is annealed and simultaneously subjected to a magnetic field of predetermined strength.
The method just recited will be described in more detail hereinafter in conjunction with the drawing wherein:
Figure 1 is a side elevational view of an assembled magnetic core made in accordance with the present invention; and .~ , , , ' .
Figures 2a - 2e diagrammatically illustrate a number of steps in the disclosed method of making the magnetic core illustrated in Figure 1.
Turning now to the drawing, wherein like components are S designated by like reference numerals throughout the various figures, attention is first directed to Figure 1 which, as stated above, illustrates a magnetic core assembled in accordance with the present invention. This core which is generally indicated at 10 and which is especially suitable for use in a transformer or like electrical induction ap-paratus initially formed from a continuous strip of amor-phous metal, for example the METGLASR strip material re-ferred to previously. The core can be round, rectangular, somewhat rectangular as illustrated in Figure 1, or any other suitable shape. In the somewhat rectangular shape shown, the core includes opposite legs 12 and 14, an upper yoke 16 and a lower yoke 18. One of these four sections, for example the upper yoke 16, includes a joint 20 which serves as an access into and around the core for positioning an associated electrical coil or coils. One such coil is shown in Figure 1 at 22.
Joint 20 may be comprised of a planar or straight butt joint, it may be a stepped joint, a V-notched or it may take other possible shapes. In addition, the opposite end sections forming this joint may include protective coatings.
1 ~77~i2 Turning to Figures 2a through 2e, attention i8 di~ected to a preferred method of making core 10 made from one or more cont~nuous strips of amorphous metal, for example the METGhASR material referred to previously. In Figure 2a, two S continuous strips 24 are illustrated. These strlps are initially stored on their own reels 26. The first step ln the present method calls for winding the continuous strip or strips about a cylindrical mandrel 28 to form an initially round core generally indicated at 30. In the preferred method, it is important that core 30 be wound round so that the strip or strips 24 are not subjected to a jer~ing or similar irregular motion that could cause breakage. More-over, by winding the strips around mandrel 28 without ~` excessive acceleration, the speed of windingJ10 can actually be increased.
After forming an intially round core 30, the latter is clamped in the predetermined way illustrated in Figure 2b.
The clamping arrangement generally designated by the re-ference numeral 32 is shown diagrammatically in this figure to include a steel or otherwise rigid base plate 34 and two removable steel or otherwise rigid clamping plates 36.
While not shown, suitable means are provided to maintain the clamping plates 36 above base plate 34 such that the ini-t ally round core 30 is maintained therebetween in a some-what compressed, substantially oval shaped state indicatedgenerally at 38. In t~is regard, the confronting ends of the clamping plates are spaced from one another in order to expose a transverse section of the core.
With oval shaped core 38 clamped into the position illus-trated in Figure ~2b, a cutting tool, preferably a power saw including an abrasive circular saw blade 40 constructed of, for example aluminum oxide or silicon carbide with resin or rubber bond, is used to cut entirely through the previously mentioned exposed transverse section rom one edge of the oval shaped core to its opposite edge. In this regard, the ' -1 ~7~28 power saw itself may be a table ox ~adial a~ saW and ~n appropr~ate steel or otherwise rig~d ~lock 42 is preferably disposed inside the core, as shown in Figure 2b, to receive the inwardly projecting edge of saw blade 40 ~or guiding the latter across the core as the ~lade cuts through the exposed transverse section thereof. At the sa~e time, block 42 serves as a support between the base plate 34 and clamping plates 36 for allowing greater compression of the core laminations on either side of the transVerse section being cut. This reduces the possibility of backcracking, burrlng and/or swelling along the cut. In any event, once the cut is made, a plurality of unconnected elongated strips of the material result.
An amorphous metal is a non-crystalline material. When the amorphous metal is overheated, the material degrades its ~uperior magnetic characteristics ~or loses ~ non-crys-talline characteristics). Therefore, a supply of rust inhibiting coolant is needed to prevent overheating while cutting. Contact pressure between the material and the cutting wheel is critical. ~eat will generate easily un~er high contact pressure. The contact pressure is controlled by the wheel running speed and the advance speed of the work piece. The proper wheel running speed was 100 to 120 ft/sec and the advance speed of the work piece was 2 inch square per hour for cutting in an actual embodiment.
This of course may vary depending upon the cutting wheel and material being cut. The supply of rust inhibiting coolant is continuously supplied in the form of a spray by suitable means including, for example, two nozzles generally indicated at 44 in Figure 2b. In a preferred embodiment, the coolant is a water based coolant, specifically water containing Nu-oil from Pittsburgh Chemical Mfg. Co. as a rust inhibitor. Nevertheless, in order to further prevent rusting, the various unconnected elongated strips which resulted from the cutting operation as discussed above, are a~ soaked in an alcohol base compound, specifically methyl , 1 ~77~2~
alcohol to remove most of the wate$ coolant. The uncon-nected strips are then heated in an oven, p~efe~r~ly at 125C, for a period of time su~ficient for them to d~y.
While the present invention is not limited to a water b~se coolant, although it is preferred, and while the present invention is not limited to the particular parameters used in the drying of the strips, when a water based coolant is used, the drying step just mentioned is a very necessary step in the overall process to prevent excessiVe rustinq and swelling. The little oxide that is left on the unconnected strips as a result of the water is so thin that it does not appreciably affect the space factor between turns of the ultimately formed core, but does beneficially increase surface resistance. After this treatment, the unconnected lS strips will more readily slide past one another and not stick together so that they can be separated into groups and provided with the appropriate end shapes to be discussed.
As just stated, once the oval core 38 is cut and the re-sulting 1mconnected strips are dried (assuming a water based coolant is used) the individual unconnected strips are assembled into a number of groups having specifically shaped ends depending upon the particular type of joint 20 desired in the end product. One group of unconnected strips is shown in Figure 2c and generally indicated at ~6. This group is shown having tapered ends 46a and 46~ necessary to provide the ultimately shape2 joint shown in Figure 1. This particular configuration may be provided by initially taking the full stack of unconnected strips and lining them up square on one end by tapping the ends with a flat block.
If more slope is required, the stacks can be shifted by alternately clamping one end of the stack and then the other end, synchronized with flexing of the stack. For some types of joints, such as an alternate butt lap joint, this shift-ing is unnecessary. ~ith the exception of a square butt joint or a sloping butt joint, the stack is eivided into the previously mentioned indivi2ual groups 46. In any case, if 1 177~8 ~he ends of each group are to ha~e the co~tings descxihed in - the above-recited Lin et al patent application~ such co~t-ings would be provided at this ti~e.
Once the indi~idual groups 46 are provided, the outermost group, e.g. the group of longest unconnected strip~
fixedly maintained in an oval ~preferably ellipt~c41~ shape with its ends brought together and taped to remain in place, as illustrated in Figure 2d. As seen there, outermost group 46 is held in the position just descri~ed by suitable means, for example a pair of confronting clamping plates 4~. Once outer group 46 i5 SO positionea, the remaining groups are successively placed, one at a time, inside the oute D st group starting with the next longest group of unconnècted strips and ending with the shortest group. This is ac-complished by flexing each individual group into its self so ~ that the latter may be located concentrically within thelast assembled qroup. The group being so assembled is then allowed to snap back into position such that its oppos~te ends engage one another in the manner shown ~n Figure 2d.
20. While not shown, a wire, band or other suitable means may be provided to prevent disassembly of the ultimately formed oval (or elliptical) core formed between the clamping plates 48 when the latter are ved. The oval ~or elliptical) core is generally indicated at 49.
Once core 49 has been formed, if its oval or elliptical shape is not the shape desired for end core 10, the end shape is provided. This is best accomplished using a series of clamps which may be readily provided. For ex-ample, Figure 2e illustrates a series of inner and outer clamping plates 50 which comprise part of an overall clamp-ing apparatus 52 readily pro~ided by those with ordinary skill in the art. While not shown, the overall apparatus will include means or adjusting the space between the ~arious confronting plates and the location of the plates relative to one another to provide the desired shape for the '~';
.- -`` - I 177~2 core. In Figure 2e, the oval or elliptical core 48 in Figure 2d is shown converted to the somewhat rectangular shape of Figure 1. This rectangularly shaped core which is generally designated by the reference numeral 53 is provided with a current coil 54 which is wound around one section thereof. This coil which is indicated generally at 54 is connected to a source current, either direct current or alternating current 56 resulting in the passage of current generally indicated at I through the coil. This current, in turn, subjects the coil to a magnetic field. In a preferred embodiment, this field is between 5 and 20 oersteds, speci-fically 10 oersteds in a most preferred embodiment. At the same time, the entire core is annealed, preferably in a protective atmosphere, for example, a vacuum, an inert gas such as argon or a reducing gas such as a mixture of nitrogen and hydrogen. In a preferred embodiment, the core is annealed for between 1 and 3 hours, most preferably for two hours, at a temperature between about 340C and 370C
(the range of these temperatures is suitable for Allied Chemical Corp's METGLASR materials 2605S and 2605SC). The core is cooled down preferably gradually specifically at a rate of 1.67C per minute until the core is 150C. By annealing the core and subjecting it to a magnetic field as described, its core losses are reduced, as is known. Once the core 52 has been annealed and subjected to the magnetic field, the coil 54 can be removed and the final electrical coil or coils 22 can be placed around one section thereof in a suitable manner.
. . .
In view of the foregoing, it is a main object of the present invention to provide a relatively uncomplicated and eco-no~ical method of making a magnetic core from amorphous strip metal for use in a transformer or like electrical induction apparatus and particularly a method which is reliable in use. As will be described in more detail hereinafter, the method disclosed starts with a continuous strip of non-annealed amorphous metal which is initially wound about a cyclindrical mandrel to form an initially round core and thereafter clamped in a predetermined way and cut entirely through a predetermined transverse section.
This cutting procedure, which requires the application of a rust inhibiting liquid coolant at the cutting section of the core, results in a plurality of unconnected elongated metal strips. The unconnected strips are separated into the number of individual groups which are assembled, one group at a time, into a substantially oval shaped core and then formed into its final shape, if not already in its final shape. Thereafter, the core is annealed and simultaneously subjected to a magnetic field of predetermined strength.
The method just recited will be described in more detail hereinafter in conjunction with the drawing wherein:
Figure 1 is a side elevational view of an assembled magnetic core made in accordance with the present invention; and .~ , , , ' .
Figures 2a - 2e diagrammatically illustrate a number of steps in the disclosed method of making the magnetic core illustrated in Figure 1.
Turning now to the drawing, wherein like components are S designated by like reference numerals throughout the various figures, attention is first directed to Figure 1 which, as stated above, illustrates a magnetic core assembled in accordance with the present invention. This core which is generally indicated at 10 and which is especially suitable for use in a transformer or like electrical induction ap-paratus initially formed from a continuous strip of amor-phous metal, for example the METGLASR strip material re-ferred to previously. The core can be round, rectangular, somewhat rectangular as illustrated in Figure 1, or any other suitable shape. In the somewhat rectangular shape shown, the core includes opposite legs 12 and 14, an upper yoke 16 and a lower yoke 18. One of these four sections, for example the upper yoke 16, includes a joint 20 which serves as an access into and around the core for positioning an associated electrical coil or coils. One such coil is shown in Figure 1 at 22.
Joint 20 may be comprised of a planar or straight butt joint, it may be a stepped joint, a V-notched or it may take other possible shapes. In addition, the opposite end sections forming this joint may include protective coatings.
1 ~77~i2 Turning to Figures 2a through 2e, attention i8 di~ected to a preferred method of making core 10 made from one or more cont~nuous strips of amorphous metal, for example the METGhASR material referred to previously. In Figure 2a, two S continuous strips 24 are illustrated. These strlps are initially stored on their own reels 26. The first step ln the present method calls for winding the continuous strip or strips about a cylindrical mandrel 28 to form an initially round core generally indicated at 30. In the preferred method, it is important that core 30 be wound round so that the strip or strips 24 are not subjected to a jer~ing or similar irregular motion that could cause breakage. More-over, by winding the strips around mandrel 28 without ~` excessive acceleration, the speed of windingJ10 can actually be increased.
After forming an intially round core 30, the latter is clamped in the predetermined way illustrated in Figure 2b.
The clamping arrangement generally designated by the re-ference numeral 32 is shown diagrammatically in this figure to include a steel or otherwise rigid base plate 34 and two removable steel or otherwise rigid clamping plates 36.
While not shown, suitable means are provided to maintain the clamping plates 36 above base plate 34 such that the ini-t ally round core 30 is maintained therebetween in a some-what compressed, substantially oval shaped state indicatedgenerally at 38. In t~is regard, the confronting ends of the clamping plates are spaced from one another in order to expose a transverse section of the core.
With oval shaped core 38 clamped into the position illus-trated in Figure ~2b, a cutting tool, preferably a power saw including an abrasive circular saw blade 40 constructed of, for example aluminum oxide or silicon carbide with resin or rubber bond, is used to cut entirely through the previously mentioned exposed transverse section rom one edge of the oval shaped core to its opposite edge. In this regard, the ' -1 ~7~28 power saw itself may be a table ox ~adial a~ saW and ~n appropr~ate steel or otherwise rig~d ~lock 42 is preferably disposed inside the core, as shown in Figure 2b, to receive the inwardly projecting edge of saw blade 40 ~or guiding the latter across the core as the ~lade cuts through the exposed transverse section thereof. At the sa~e time, block 42 serves as a support between the base plate 34 and clamping plates 36 for allowing greater compression of the core laminations on either side of the transVerse section being cut. This reduces the possibility of backcracking, burrlng and/or swelling along the cut. In any event, once the cut is made, a plurality of unconnected elongated strips of the material result.
An amorphous metal is a non-crystalline material. When the amorphous metal is overheated, the material degrades its ~uperior magnetic characteristics ~or loses ~ non-crys-talline characteristics). Therefore, a supply of rust inhibiting coolant is needed to prevent overheating while cutting. Contact pressure between the material and the cutting wheel is critical. ~eat will generate easily un~er high contact pressure. The contact pressure is controlled by the wheel running speed and the advance speed of the work piece. The proper wheel running speed was 100 to 120 ft/sec and the advance speed of the work piece was 2 inch square per hour for cutting in an actual embodiment.
This of course may vary depending upon the cutting wheel and material being cut. The supply of rust inhibiting coolant is continuously supplied in the form of a spray by suitable means including, for example, two nozzles generally indicated at 44 in Figure 2b. In a preferred embodiment, the coolant is a water based coolant, specifically water containing Nu-oil from Pittsburgh Chemical Mfg. Co. as a rust inhibitor. Nevertheless, in order to further prevent rusting, the various unconnected elongated strips which resulted from the cutting operation as discussed above, are a~ soaked in an alcohol base compound, specifically methyl , 1 ~77~2~
alcohol to remove most of the wate$ coolant. The uncon-nected strips are then heated in an oven, p~efe~r~ly at 125C, for a period of time su~ficient for them to d~y.
While the present invention is not limited to a water b~se coolant, although it is preferred, and while the present invention is not limited to the particular parameters used in the drying of the strips, when a water based coolant is used, the drying step just mentioned is a very necessary step in the overall process to prevent excessiVe rustinq and swelling. The little oxide that is left on the unconnected strips as a result of the water is so thin that it does not appreciably affect the space factor between turns of the ultimately formed core, but does beneficially increase surface resistance. After this treatment, the unconnected lS strips will more readily slide past one another and not stick together so that they can be separated into groups and provided with the appropriate end shapes to be discussed.
As just stated, once the oval core 38 is cut and the re-sulting 1mconnected strips are dried (assuming a water based coolant is used) the individual unconnected strips are assembled into a number of groups having specifically shaped ends depending upon the particular type of joint 20 desired in the end product. One group of unconnected strips is shown in Figure 2c and generally indicated at ~6. This group is shown having tapered ends 46a and 46~ necessary to provide the ultimately shape2 joint shown in Figure 1. This particular configuration may be provided by initially taking the full stack of unconnected strips and lining them up square on one end by tapping the ends with a flat block.
If more slope is required, the stacks can be shifted by alternately clamping one end of the stack and then the other end, synchronized with flexing of the stack. For some types of joints, such as an alternate butt lap joint, this shift-ing is unnecessary. ~ith the exception of a square butt joint or a sloping butt joint, the stack is eivided into the previously mentioned indivi2ual groups 46. In any case, if 1 177~8 ~he ends of each group are to ha~e the co~tings descxihed in - the above-recited Lin et al patent application~ such co~t-ings would be provided at this ti~e.
Once the indi~idual groups 46 are provided, the outermost group, e.g. the group of longest unconnected strip~
fixedly maintained in an oval ~preferably ellipt~c41~ shape with its ends brought together and taped to remain in place, as illustrated in Figure 2d. As seen there, outermost group 46 is held in the position just descri~ed by suitable means, for example a pair of confronting clamping plates 4~. Once outer group 46 i5 SO positionea, the remaining groups are successively placed, one at a time, inside the oute D st group starting with the next longest group of unconnècted strips and ending with the shortest group. This is ac-complished by flexing each individual group into its self so ~ that the latter may be located concentrically within thelast assembled qroup. The group being so assembled is then allowed to snap back into position such that its oppos~te ends engage one another in the manner shown ~n Figure 2d.
20. While not shown, a wire, band or other suitable means may be provided to prevent disassembly of the ultimately formed oval (or elliptical) core formed between the clamping plates 48 when the latter are ved. The oval ~or elliptical) core is generally indicated at 49.
Once core 49 has been formed, if its oval or elliptical shape is not the shape desired for end core 10, the end shape is provided. This is best accomplished using a series of clamps which may be readily provided. For ex-ample, Figure 2e illustrates a series of inner and outer clamping plates 50 which comprise part of an overall clamp-ing apparatus 52 readily pro~ided by those with ordinary skill in the art. While not shown, the overall apparatus will include means or adjusting the space between the ~arious confronting plates and the location of the plates relative to one another to provide the desired shape for the '~';
.- -`` - I 177~2 core. In Figure 2e, the oval or elliptical core 48 in Figure 2d is shown converted to the somewhat rectangular shape of Figure 1. This rectangularly shaped core which is generally designated by the reference numeral 53 is provided with a current coil 54 which is wound around one section thereof. This coil which is indicated generally at 54 is connected to a source current, either direct current or alternating current 56 resulting in the passage of current generally indicated at I through the coil. This current, in turn, subjects the coil to a magnetic field. In a preferred embodiment, this field is between 5 and 20 oersteds, speci-fically 10 oersteds in a most preferred embodiment. At the same time, the entire core is annealed, preferably in a protective atmosphere, for example, a vacuum, an inert gas such as argon or a reducing gas such as a mixture of nitrogen and hydrogen. In a preferred embodiment, the core is annealed for between 1 and 3 hours, most preferably for two hours, at a temperature between about 340C and 370C
(the range of these temperatures is suitable for Allied Chemical Corp's METGLASR materials 2605S and 2605SC). The core is cooled down preferably gradually specifically at a rate of 1.67C per minute until the core is 150C. By annealing the core and subjecting it to a magnetic field as described, its core losses are reduced, as is known. Once the core 52 has been annealed and subjected to the magnetic field, the coil 54 can be removed and the final electrical coil or coils 22 can be placed around one section thereof in a suitable manner.
. . .
Claims (9)
1. A method of making a transformer core constructed of amorphous strip metal, comprising the steps of:
(a) Winding at least one continuous strip of amorphous metal about a cylindrical mandrel to form an initially round core;
(b) thereafter, clamping together transverse sections of said initially round core on opposite sides of a prede-termined transverse section such that the latter is sufficiently exposed for cutting by a specific cutting tool;
(c) cutting entirely through said exposed transverse section with said cutting tool while simultaneously applying a rust inhibiting liquid coolant onto said core and cutting tool at said exposed section, whereby to form a plurality of unconnected elongated strips of said metal;
(d) freeing said cut core and separating all of said unconnected strips into a number of groups shaped at their opposite ends in a predetermined way;
(e) assembling all of said groups into a substantially oval shaped core by first forming and maintaining the outer-most one of said groups into said oval shape with its opposite ends in abutting engagement with one another and thereafter successively placing the remaining groups, one at a time, into the outermost group with its opposite ends in abutting engagement with one another such that the opposite ends of each group define one segment of a specifically shaped joint across a transverse section of said oval shaped core; and (f) thereafter, annealing said core while simul-taneously subjecting it to a magnetic field of predetermined strength.
(a) Winding at least one continuous strip of amorphous metal about a cylindrical mandrel to form an initially round core;
(b) thereafter, clamping together transverse sections of said initially round core on opposite sides of a prede-termined transverse section such that the latter is sufficiently exposed for cutting by a specific cutting tool;
(c) cutting entirely through said exposed transverse section with said cutting tool while simultaneously applying a rust inhibiting liquid coolant onto said core and cutting tool at said exposed section, whereby to form a plurality of unconnected elongated strips of said metal;
(d) freeing said cut core and separating all of said unconnected strips into a number of groups shaped at their opposite ends in a predetermined way;
(e) assembling all of said groups into a substantially oval shaped core by first forming and maintaining the outer-most one of said groups into said oval shape with its opposite ends in abutting engagement with one another and thereafter successively placing the remaining groups, one at a time, into the outermost group with its opposite ends in abutting engagement with one another such that the opposite ends of each group define one segment of a specifically shaped joint across a transverse section of said oval shaped core; and (f) thereafter, annealing said core while simul-taneously subjecting it to a magnetic field of predetermined strength.
2. A method according to Claim 1 wherein said coolant includes water and wherein said unconnected strips are soaked in an alcohol solution and then heat dried before being assembled into said groups.
3. A method according to Claim l wherein said cutting tool includes an abrasive wheel constructed of aluminum oxide or silicon carbide with resin or rubber bond.
4. A method according to Claim l wherein said final shaped core is annealed in a special non-ambient atmosphere for about two hours at a temperature of between about 340°C and 370°C while subjecting it to a magnetic field strength of at least about 5 oersteds to 20 oersteds.
5. A method according to Claim 4 wherein said annealed core is initially cooled from its maximum temperature to about 150°C at a rate of about 1.67°C/minute (or 105°/hour).
6. A method according to Claim 1 wherein said cutting step is controlled and said coolant is provided such that the temperature of said strip material as a result of said cutting step remains sufficiently low so that said strip material retains its amorphous non-crystalline characteristics.
7. In a method of making a transformer core constructed of amorphous strip material including the steps of forming an initially shaped circumferential core body from at least one continuous strip of amorphous metal, thereafter cutting entirely through a transverse section of said core body so as to form a plurality of unconnected elongated, successively shorter sections of said continuous strip, combining said strips into a plurality of successively shorter groups there-of, forming said transformer core from said groups, and annealing said formed core, the improvement comprising:
(a) after providing said separate groups of un-connected elongated segments of said strip metal, forming the longest one of said groups into the circumferential shape with its opposite ends in abutting engagement with each other and at least temporarily maintaining this shape fixed; and (b) thereafter, successively placing all of the remaining groups, one at a time starting with the longest of the remaining groups and ending with the shortest group, within the longest group with the opposite ends of each successive group in abutting engagement with each other, so as to form an entire circumferential core and such that the opposite ends of each group define one segment of a specifically shaped butt-type joint across a transverse section of the formed core.
(a) after providing said separate groups of un-connected elongated segments of said strip metal, forming the longest one of said groups into the circumferential shape with its opposite ends in abutting engagement with each other and at least temporarily maintaining this shape fixed; and (b) thereafter, successively placing all of the remaining groups, one at a time starting with the longest of the remaining groups and ending with the shortest group, within the longest group with the opposite ends of each successive group in abutting engagement with each other, so as to form an entire circumferential core and such that the opposite ends of each group define one segment of a specifically shaped butt-type joint across a transverse section of the formed core.
8. A method according to claim 7 wherein each of said groups consists of a number of said unconnected strips.
9. A method according to Claim 1, wherein said oval shaped core is formed into a different, final shape after its assembly and prior to it being annealed and simultaneously subjected to a magnetic field of predetermined strength.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17707580A | 1980-08-11 | 1980-08-11 | |
| US177,075 | 1980-08-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1177628A true CA1177628A (en) | 1984-11-13 |
Family
ID=22647084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000382392A Expired CA1177628A (en) | 1980-08-11 | 1981-07-23 | Method of making a transformer or like core from amorphous strip metal |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS5754308A (en) |
| KR (1) | KR830006786A (en) |
| AU (1) | AU7316981A (en) |
| BE (1) | BE889934A (en) |
| BR (1) | BR8105132A (en) |
| CA (1) | CA1177628A (en) |
| ES (1) | ES504669A0 (en) |
| FR (1) | FR2488438A1 (en) |
| GB (1) | GB2081611B (en) |
| IT (1) | IT1146050B (en) |
| NO (1) | NO812640L (en) |
| YU (1) | YU193981A (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO824097L (en) * | 1981-12-11 | 1983-06-13 | Westinghouse Electric Corp | PROCEDURE FOR THE MANUFACTURING OF MAGNETIC CORES FROM AMORFT BAND METAL. |
| JPS5979515A (en) * | 1982-10-29 | 1984-05-08 | Aichi Electric Mfg Co Ltd | Manufacture of transformer core |
| GB2133932A (en) * | 1982-12-31 | 1984-08-01 | Int Research & Dev Co Ltd | Improvements to strip wound magnetic cores |
| DE3322136A1 (en) * | 1983-06-20 | 1984-12-20 | Transformatoren Union Ag, 7000 Stuttgart | Method for producing magnetic cores for transformers and inductor coils with high rated powers |
| JPS6091611A (en) * | 1983-10-25 | 1985-05-23 | Toshiba Corp | Manufacture of wound core |
| DE3484066D1 (en) * | 1983-11-14 | 1991-03-07 | Gen Electric | HEATING AN AMORPHOUS METAL TO EASIER CUTTING. |
| CA1211169A (en) * | 1984-04-03 | 1986-09-09 | Nicolai Alexandrov | Distribution transformer with woundmagnetic circuit |
| JPS60208815A (en) * | 1984-04-03 | 1985-10-21 | Aichi Electric Mfg Co Ltd | Manufacture of wound iron core |
| JPS6176938U (en) * | 1984-10-25 | 1986-05-23 | ||
| JPS61180411A (en) * | 1985-02-05 | 1986-08-13 | Toshiba Corp | Manufacture of wound core structure |
| US6146462A (en) * | 1998-05-08 | 2000-11-14 | Astenjohnson, Inc. | Structures and components thereof having a desired surface characteristic together with methods and apparatuses for producing the same |
| US6287687B1 (en) | 1998-05-08 | 2001-09-11 | Asten, Inc. | Structures and components thereof having a desired surface characteristic together with methods and apparatuses for producing the same |
| CN103667673B (en) * | 2013-12-06 | 2016-07-06 | 青岛云路先进材料技术有限公司 | A kind of cooling treatment method of amorphous powder core |
| KR102124788B1 (en) | 2020-02-28 | 2020-06-19 | 티에이치산업주식회사 | Method for fabricating metal plate of electric transformer core |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR980613A (en) * | 1948-02-13 | 1951-05-16 | Westinghouse Electric Corp | Induction electric appliances |
| FR1111238A (en) * | 1954-09-03 | 1956-02-23 | Mcgraw Electric Co | Magnetic cores for transformers |
| FR1371508A (en) * | 1963-10-01 | 1964-09-04 | Thomson Houston Comp Francaise | Manufacturing process of preformed magnetic cores with single winding and corresponding magnetic cores |
| FR1419660A (en) * | 1964-08-05 | 1965-12-03 | Westinghouse Electric Corp | Magnetic cores for induction devices |
| FR1473573A (en) * | 1966-03-29 | 1967-03-17 | Telcon Magnetic Cores Ltd | Transformer cores and method of manufacturing said cores |
| FR2137372B1 (en) * | 1971-05-17 | 1973-05-25 | Augier Ets |
-
1981
- 1981-07-21 AU AU73169/81A patent/AU7316981A/en not_active Abandoned
- 1981-07-23 CA CA000382392A patent/CA1177628A/en not_active Expired
- 1981-08-04 NO NO812640A patent/NO812640L/en unknown
- 1981-08-07 IT IT41625/81A patent/IT1146050B/en active
- 1981-08-08 KR KR1019810002896A patent/KR830006786A/en unknown
- 1981-08-10 FR FR8115455A patent/FR2488438A1/en active Granted
- 1981-08-10 BR BR8105132A patent/BR8105132A/en unknown
- 1981-08-10 ES ES504669A patent/ES504669A0/en active Granted
- 1981-08-11 YU YU01939/81A patent/YU193981A/en unknown
- 1981-08-11 GB GB8124516A patent/GB2081611B/en not_active Expired
- 1981-08-11 BE BE0/205647A patent/BE889934A/en not_active IP Right Cessation
- 1981-08-11 JP JP56124830A patent/JPS5754308A/ja active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| KR830006786A (en) | 1983-10-06 |
| IT8141625A0 (en) | 1981-08-07 |
| FR2488438B1 (en) | 1984-06-15 |
| YU193981A (en) | 1983-09-30 |
| BE889934A (en) | 1982-02-11 |
| GB2081611B (en) | 1983-12-21 |
| FR2488438A1 (en) | 1982-02-12 |
| BR8105132A (en) | 1982-04-27 |
| JPS5754308A (en) | 1982-03-31 |
| AU7316981A (en) | 1982-02-18 |
| ES8301554A1 (en) | 1982-12-01 |
| IT1146050B (en) | 1986-11-12 |
| ES504669A0 (en) | 1982-12-01 |
| GB2081611A (en) | 1982-02-24 |
| NO812640L (en) | 1982-02-12 |
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