JPH04241408A - Manufacture of transformer core composed of amorphous steel band wound around core window - Google Patents

Abstract

PURPOSE: To provide an effective method for eliminating the need for a liquid for covering the retaining steel bands together while a plurality of amorphous steel bands sent into a belt nester as a group of a plurality of steel bands are being wound when winding them around a rotating arbor to manufacture a transformer core made of a plurality of amorphous steel bands wound around the window of the core. CONSTITUTION: A group of steel bands 120 made of a plurality of amorphous steel bands 112 are overlapped while being shifted in the longitudinal direction, thus forming a plurality of packets 110. A group of steel bands 120 are manufactured by a method including a prespooling process for adhering a plurality of steel bands and a group of steel bands in each packet 110 together even if they are dry. Each packet 110 is successively sent into a belt nester 128. The belt nester 128 wind the packet 110 around the arbor when the arbor 130 and the belt master overlap rotate. In the mean time, the deviation of a steel band 112 and a group of steel bands 120 in the longitudinal direction can be prevented.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to a method of manufacturing a transformer core comprising a plurality of amorphous steel strips wound in overlapping relation around a core window, and more particularly to a method of manufacturing a transformer core consisting of a plurality of amorphous steel strips wound in overlapping relation around a core window, and more particularly to a method of manufacturing a transformer core consisting of a plurality of amorphous steel strips wound in overlapping relation around a core window, and more particularly to a method of manufacturing a transformer core consisting of a plurality of amorphous steel strips wound in overlapping relation around a core window, and more particularly to a plurality of packets made from a plurality of groups of steel strips. belt nester for wrapping a packet around a rotating arbor
The present invention relates to the above manufacturing method using.

0002

BACKGROUND OF THE INVENTION One type of core making machine that has been utilized for many years to make transformer cores is the belt nester. Typically, a belt nester includes a rotatable arbor such that as the arbor rotates, sections of magnetic steel strip of regulated length are wrapped around the arbor in overlapping relation, thereby sequentially An iron core forming body is created whose diameter increases as the band is wrapped around it. Wrapping of the steel strip is accomplished through the use of a flexible belt placed around the arbor and driven to rotate the arbor and the steel strip previously wrapped around the arbor. The steel strip is fed into the belt nester between the arbor and the belt. As the belt and arbor move together, each incoming steel strip or group of steel strips is forced by the belt to wrap around the arbor or core formation already formed on the arbor. A representative example of a belt nester of the type described above is disclosed in U.S. Pat. No. 3,049,793.

[0003]The above type of belt nester has hitherto been
It was used to manufacture an iron core from multiple amorphous steel strips that were wrapped around a rotating arbor. Amorphous steel strips are extremely thin (e.g., typically only about 0.2 mm thick).
0254 mm (=1 mil)), it is common and highly desirable to feed multiple steel strip groups into a belt nester, with each steel strip group being formed from at least 10 overlapping steel strips. . However, one problem that exists when using multiple groups of amorphous steel strips in a belt nester is that during the nesting process the steel strips are removed within the group of steel strips and onto the arbor or partially completed rotating core formation. It has a tendency to slip in the direction of rotation. This is because these steel strips must be positioned accurately and predictably.
This is a serious problem. To overcome this problem, immediately prior to belt nesting, the steel strips have been coated with a volatile liquid such as perchlorethylene that can hold the steel strips together in the manner necessary for effective belt nesting. but,
This is by no means a satisfactory solution since perchlorethylene is expensive, environmentally undesirable, and can cause rust or corrosion problems.

0004

OBJECTS OF THE INVENTION A first object of the present invention is to manufacture a transformer core consisting of a plurality of amorphous steel strips wound around a core window. The object of the present invention is to provide a method that can be effectively achieved by winding an amorphous steel strip around a rotatable arbor.

Another object of the invention is to provide a method for holding a plurality of amorphous steel strips together while they are being wound around an arbor without requiring any liquid. The purpose is to achieve the first objective above.

[0006]

SUMMARY OF THE INVENTION In practicing the present invention, a plurality of packets of amorphous steel strip are assembled. Each packet consists of a plurality of stacked amorphous steel strips, each strip group consisting of at least one section of a multilayer amorphous steel strip. These amorphous steel strip sections are obtained by cutting into regulated lengths a composite amorphous steel strip created by joining multiple multi-thickness steel strips fed from multiple master spools. . The multi-layer steel strip in each master spool is pre-spooled.
-spooling) machine receives single thickness steel strip from a plurality of mill-wound spools and combines the single-wall thickness steel strip unwound from the plurality of mill-wound spools.

[0007] When the above method including this pre-spooling is used to produce the above composite steel strip, the plurality of steel strips in each section cut from the composite steel strip are substantially dry. However, it adheres to the juxtaposed steel strips as if there was an adhesive between the juxtaposed steel strips. This adhesive effect allows the above-mentioned cut parts to be attached without the need for liquid previously used to hold the steel strip from shifting while wrapping it around the arbor during nesting. It is then possible to build up a tight packet from the base and feed it into a belt nester containing a rotatable arbor.

[0008]

[Detailed description of examples]

Packet FIGS. 1 and 2 illustrate one of a number of packets used to construct a transformer core according to the method of the present invention.
One packet 110 is shown. The packet 110 of FIGS. 1 and 2 is formed from multiple stacked elongated amorphous steel strips. Each steel strip is made of 0.178 grain-oriented silicon steel strip, which is the most commonly used material for distribution transformer cores.
It is extremely thin compared to typical thicknesses of only about 0.0254 mm (7-12 mils).
= 1 mil). Each steel strip includes longitudinally extending side edges 114 and transversely extending edges 116. The stacked steel strips constitute a plurality of steel strip groups 120, each steel strip group consisting of, for example, 10 to 36 steel strips. Each steel strip group 1
At 20, all of the steel strip side edges 114 are substantially aligned and all of the steel strip edges 116 are substantially aligned.

Packet 110 consists of a plurality of stacked steel strips 120. In each packet 10, the side edges 114 of all steel strip groups 120 are substantially aligned. However, all the steel strip groups 120 at both ends of the packet 110
The edges 116 of the packets 110 are offset from each other in the longitudinal direction of the packet 110. In each packet 110, when looking from the inside I to the outside O of the packet 110, the ends of successive steel strip groups 120 overlap so as to overlap at one end of the packet 110, and overlap so as to be drawn in sequentially at the other end of the packet 110. There is. Preferably, all packets 110 used in a transformer core have the same basic structure and the same width. However, the packets 110 (assembled to be wound one after the other around the core window) are made to have successive lengths, so that the outer circumference of the core formation increases as the packets 110 are wound one after the other. It can be so. In carrying out the method of the invention, all packets 110 and their parts are:
Manufactured by a special method which will be described in more detail. Belt Nester 128 A winding machine of the type commonly referred to as a belt nester is used to form the core from a plurality of packets such as those shown at 110 in FIGS. 1 and 2. Referring to FIGS. 3 and 4, a belt nester generally designated 128 is constructed of a steel hub 1 having a circular outer circumference 132.
31 and two guide flanges 134 and 136 removably attached to hub 131 on either side of hub 131.
and a rotating arbor 130 that includes a rotary arbor 130. Each guide flange 1
34 and 136 extend radially outwardly beyond the outer periphery 132 of the hub 131 such that there is a space 137 in a U-shaped cross section at the outer periphery of the arbor 130. Each flange 134 and 136 is preferably made primarily of aluminum. However, each flange 134 and 136 includes a wear-resistant stainless steel sheet 138 bonded to its inner surface. As will be explained in detail later, a plurality of packets as indicated by reference numeral 110 in FIGS. 1 and 2 are
In the space 137 between the flanges 134 and 136, the arbor 130 is wrapped around the hub 131 one after the other. The flanges 134 and 136 act as guides that cooperate with the side edges 114 of the packet 110 so that the packet 110 is aligned with the outer periphery 132 of the hub 131 with the side edges 114 on each side of the packet 110 generally aligned.
Guaranteed to be wrapped around.

A wear-resistant coating 138 on each flange 134 and 136 protects flange 134 from wear or other damage caused by the sharp edges of steel strip 110 wound within space 137.
and 136.

In order to wrap a plurality of packets 110 one after another around the hub 131 of the arbor 130, the belt nester 12
8 is an endless flexible belt 1 disposed around the hub 131;
Use 40. The belt 140 extends from a first point 141 on the front end of the arbor 130 to a first front roller 142.
, and then the three idler rollers 143, 144
and 145, then around rollers 146, 147 and 148 in belt tensioning device 150, then around three idler rollers 151, 152 and 153, then around motor driven pulley 155 and around second front roller 156. to a second point 158 on the front end of arbor 130 spaced from first point 141 and finally to a second point 158 on the front end of arbor 130 .
30 hub 131 and return to the first point 141.

[0012] The above-mentioned rollers 142, 143, 144,
145, 147, 151, 152, 153 and 156
Each is mounted by suitable means so as to be freely rotatable about a central axis provided in a fixed position. Motor drive pulley 155 is coupled to an electric motor (not shown) by a rotary drive shaft 157 attached to pulley 155. When the motor is activated to drive pulley 155, pulley 155 moves belt 140 in the direction of arrow 160 (see FIG. 3).

Belt tensioning device 150 comprises a pair of rollers 146 and 148 mounted on a horizontal crosshead 162 guided by suitable means for vertical movement and biased vertically upwardly by a spring device 164.
including. The fixed idler roller 147 also serves as the belt tensioning device 1.
Included in 50. The belt 140 is connected to the idler roller 14
5, goes around the top side of one movable roller 146, then goes around the bottom side of the idler roller 147, then goes around the top side of the other movable roller 148, and extends to the bottom side of the idler roller 152. As the core formation is formed on the arbor 130, the effective belt length must be progressively increased to allow the belt 140 to travel around increasing circumferences of the core formation. Therefore, the movable roller 146
and 148 are lowered against the bias of spring device 164 to provide the required effective belt length. As the diameter of the core formation increases over the arbor 130, the spring device 164 maintains the tension on the belt 140 approximately constant.

Each packet 1 to be wound on the arbor 130
10 is fed onto hub 131 along the upper surface of fixed guide plate 165 extending between front rollers 142 and 156. The fixed guide plate 165 is used for packet 1 entering from the right side in FIG.
It has a front end 167 that is gradually curved upward so that the leading end of the belt 10 is directed upward and fed into the space between the belt 140 and the outer periphery of the hub 131 of the arbor 130 . When the belt 140 comes into contact with the leading end of the packet 110 that has entered, the operation of the belt drive device is started, and the leading end of the packet 110 contacts the belt 140 and the hub 131 (or the core forming body present on the hub 131 at that time). ). The belt 140 is attached to the axis 16 of the arbor 130.
6, the belt 14
0, the arbor 130 is rotated in the counterclockwise direction around the axis 166, and the tip of the packet 110 is aligned with the axis 166.
6 in a counterclockwise direction. packet 11
As the leading edge of packet 110 moves in this manner, more and more of the remaining length of packet 110 is attached to belt 1.
40 and the hub 131, and the hub 131
are wound in sequence. This operation continues until the rear end of the packet 110 is wrapped. The packet 110 has a trailing end overlapping the leading end, thereby making the packet 110
The length is such that a lap joint is formed between both ends of each steel strip group 120 in the steel strip group 120. The tip of each steel strip group 120 arranged after the first (that is, the radially innermost) steel strip group 120 is
It is placed very close to the rear end of the steel strip group 120 just before that. Accordingly, a plurality of distributed lap joints, sometimes referred to as stepped lap joints, are formed between the ends of each packet 110.

FIG. 3 shows the belt nester after the arbor 130 has made approximately one revolution and the first packet 110 has been almost completely wrapped around the hub 131. The second packet 110a is in a position where it can be fed into the belt nester for wrapping around the first packet 110 after the first packet 110 has been completely wrapped.

Arbor 130 must be rotated slightly more than one revolution (ie, a short distance into the second revolution) to produce the desired overlap in the packet joint. The second rotation of arbor 130 is terminated in order to return arbor 130 to a position to receive the next packet 110, after which a new packet (e.g., packet 110 of FIG.
a) is fed into the belt nester in the same manner as described above and wrapped around the outer circumference of the previously wound packet in the same manner as described above.

A plurality of other packets are sequentially wrapped around the outer circumference of the core formation in the same manner until a core formation of the desired thickness is obtained. The other plurality of packets are wrapped such that their lap joints are placed in general radial alignment with the lap joints of the first two packets. The full-thickness core joint area is described in U.S. Pat. No. 4,741, supra.
As shown in FIG. 2 of No. 096, the length increases in the radial direction from the core window to the outer periphery of the core formation.

As shown in FIG. 4B, the arbor 13
One flange 134 of the 0 has a gap or window 135 that is circumferentially aligned with the joint area. Also, this window 1
35, the operator of the belt nester 128 immediately
The lap joints formed in each packet can be seen. If the amount of overlap in the lap joint is not within predetermined limits, the belt nester operator initiates an adjustment with the strip length control means (described shortly). Thereby, the steel strip length control means suitably adjust the length of the steel strip that is subsequently cut and thus the steel strip groups and packets that are assembled from such steel strip.

As the core formation is formed on the hub 131 of the arbor 130, the axis 166 of the arbor 130 is
It is forced to move to the left, as shown in FIG. As a result, the outer periphery of the core forming body and the front roller 1
42 to form a space for new packets to be sequentially sent to the outer periphery of the core forming body. This arbor 130
Leftward movement of the axis 166 of is made possible by a plurality of horizontal slots 168 provided in the frame 170 supporting the arbor 130. Arbor 130 has a horizontally extending support shaft 172 inserted within horizontal slot 168. The horizontally extending slot 168 also cooperates with the horizontally extending support shaft 172 to guide the arbor 130 in the desired horizontal movement. The arbor 130 is biased to the right by a belt tensioner 150 that applies a tensioning force to the belt 140. However, as other packets 110 are fed into the belt nester 128 to increase the diameter of the core formation, the hub 131
are forcibly separated from front rollers 142 and 156;
It gradually moves horizontally to the left against the rightward bias of the belt tension. Rightward movement of arbor 130 due to the bias force described above is limited by front rollers 142 and 156 that contact belt 140 that revolves around the core.

As explained in the ``Technical Background'' section, one problem encountered when multiple steel strip groups are used in a belt nester is that during the nesting process, the steel strips within the steel strip group may and a tendency to slip circumferentially on rotating arbor or partially completed rotating core formations. To overcome this problem, belt nesting has traditionally been done with volatile liquids such as perchlorethylene, which can hold multiple steel strips together to a degree sufficient to allow for effective belt nesting. The steel strip was coated just before. However, this approach is far from satisfactory because perchlorethylene is expensive, environmentally undesirable, and can cause rust or corrosion problems. Features Contributing to the Ability to Belt Nest Substantially Dry Multiple Amorphous Steel Strips on a Rotating Arbor The present invention provides a method for holding groups of steel strips together while they are being wound. Amorphous steel strips can be effectively belt-nested in a rotating arbor without resorting to perchlorethylene or similar liquids. The important steps to achieve the purpose of the present invention are:
The idea is to feed the steel strips into the belt nester in packets rather than individually. Each packet has a sufficiently large column strength when looking at the packet in the lateral direction, so that the guide flanges 134 and 136 of the rotating arbor 130 guide the packet by its side edges and act on both sides of the packet. , the packet can be seated closely within the space 127 around the outer periphery of the arbor 130 such that the side edges are aligned with the side edges of the already wrapped packet.

Also, by wrapping the steel strips in packets rather than individually, the number of rotations of the arbor 130 required to wrap all the steel strips on the core is greatly reduced. Also, this allows the arbor to remain closed while winding multiple steel strips.
The probability of undesired misalignment of individual steel strips or groups of steel strips on 30 is reduced.

Another step that is important in achieving the above objects of the present invention is a pre-spooling step that corresponds to the pre-spooling step disclosed in US Patent Application No. 505,593 filed April 6, 1990. It is to assemble a packet from a plurality of steel strip groups made by. When the steel strips are made by the above-described press pooling process, the steel strips in each steel strip group are substantially dry, but the adhesive remains as if present between the juxtaposed steel strips. To,
Glue to these juxtaposed steel strips. This adhesive action creates a tight band and a tight packet with characteristics that greatly reduce the tendency of the steel strips to slip over each other while the packet is fed into the belt nester 128 and wrapped around the arbor 130. Further details regarding pre-spooling are discussed below.

Another important feature that contributes to the ability to belt nest multiple steel strips in a rotating arbor without resorting to liquid adhesive is that the packets enter the underside of the upper front roller 142 of the belt nesting machine. From time to time, there are tight guides added to both sides of each packet. In this regard, the upper front roller 142 is connected to a pair of side edge guide retraction rollers 182 mounted on the same axis of rotation 182 to which the upper front roller 142 is mounted, as best shown in FIG. It is equipped with The packet is on the upper front roller 1
42, the edges of the packet tend to bend, curl, or lift, and in doing so have a persistent tendency to wrap around one or the other of guide flanges 134 and 136. show. The pair of retraction rollers 180 apply pressure to both side edges of the packet (thus applying a force acting radially inward on the hub 131 to the side edges), so that the side edges of the packet are pressed against the guide flanges 134 and 136. Prevent it from wrapping around,
This maintains the cylindrical shape of the core formed body. For best results, the space formed between the pair of retraction rollers 180 and their associated flanges 134 and 136 (FIG.
189) is about 0.254 m
It is formed extremely narrowly within the range of m to 1.27 mm (=0.01 to 0.15 inch). It can be seen from FIGS. 4 and 5 that the width of the belt 140 of the belt nester is much smaller than the width of the steel strip and does not extend to the pair of pull-in rollers 180. As a result, these retraction rollers 180
The exposed outer circumferential surface of is utilized to pressurize the side edges of the packet, thereby preventing these side edges from climbing up the guide flanges 134 and 136.

A shaft 182 carrying a pair of retraction rollers 180 and an upper front roller 142 is mounted in axially spaced bearings (shown schematically at 186 and 188). These bearings are secured to frame 170 by suitable mounting structures (not shown). A method for forming steel strips using a press pooling process is described in U.S. Patent Application No. 505,
6 and 7, which are substantially identical to FIGS. 1 and 2 of the '593 patent.

FIG. 6 shows five starting spools 12 of steel strip.
, 14, 16, 18 and 20 is shown. These starting spools 12, 14, 16, 18 and 20 are spools received from a steel rolling mill. Thus, in each starting spool 12, 14, 16, 18 and 20, the steel strip has a single layer thickness. The basic purpose of the press spooling machine 10 is to
A plurality of single-thickness steel strips unwound from zero are combined to form a multi-thickness steel strip that is wound onto a master reel 24 as a master spool 25.

Each starting spool is mounted on a fixed axis rotating spindle 26 which is coupled to the rotor of an adjustable speed electric motor 27. The electric motor 27 moves the spindle 26 in a counterclockwise direction (arrow X
unwinding of the associated starting spool by forward rotation (in the direction shown). The master reel 24 is also typically a fixed axis rotating spindle 2 coupled to the rotor of an electric motor 23 rotating at a substantially constant speed.
It is attached to 8. Electric motor 23 winds the multi-thickness steel strip onto master reel 24 by rotating spindle 28 clockwise (in the direction indicated by arrow Y) when powered. The single thickness steel strip unwound from each starting spool is fed to a master reel 24 through a series of guide rollers. These single thickness steel strips are designated 29a, 29b, 29c, 29d and 29e.

The guide rollers for the steel strip unwound from the first starting spool 12 are designated at 30, 31 and 32. Guide rollers for the steel strip unwound from the second starting spool 14 are designated by 34, 35 and 36. Similar guide rollers are present for the strip unwound from each starting spool.

The five single-thickness steel strips unwound from the five starting spools are joined at the outer periphery of master spool 25 to form a multi-thickness steel strip. This multi-thickness steel strip is wound onto the master spool 25 as the spindle 28 of the master reel 24 rotates clockwise.

As each single thickness steel strip is wound onto the master reel 24, belt tension rollers 40 are attached to each starting spool in order to maintain each single thickness steel strip under proper tension. It acts on a downwardly extending loop 41 of the steel strip which is provided adjacent to the steel strip and is arranged between two guide rollers for the associated steel strip. Each belt tensioning roller 40 is conventionally mounted for vertical movement and gravity biased downwardly by a suitable weight. This gravity bias acts on the steel strip through belt tensioning rollers 40 and holds the steel strip taut. This ensures that the multi-thickness steel strip is wound smoothly and closely onto the master reel 24. According to one embodiment of the invention, each belt tensioning roller 40 weighs approximately 0.268 kg per cm of steel strip width.
(=1.5 lb/in) weight downwardly biased.

In order to control the unwinding of starting spools 12, 14, 16, 18 and 20 while the multi-thickness steel strip is being wound onto master reel 24, a suitable controller 31 controls the electrical output for each starting spool. It is provided for the motor 27. The controller 31 is of a conventional type and includes a dancer arm that moves the belt tension roller 40 up and down.
arm) 33. The controller 31 causes the associated motor 27 to operate at a speed that varies depending on the vertical position of the belt tensioning roller 40. The starting spool (e.g., starting spool 12) is reduced in diameter by unwinding;
As the master spool 25 increases in diameter due to winding, the amount of unwound steel strip extending between the two spools 12 and 25 tends to decrease. This shortens the loop 41 and causes the belt tensioning roller 40 to rise. Controller 31 responds to the increase in the position of belt tensioning roller 40 by increasing the rotational speed of motor 27. This provides more unwound strip and lowers belt tensioning roller 40 to its illustrated normal vertical position. When the belt tensioning roller 40 is lowered beyond its normal vertical position, the controller 31 reduces the rotational speed of the motor 27. This results in loop 4
1 is shortened and the belt tensioning roller 40 returns to its normal vertical position.

Belt tension roller 40 and controller 31 therefore (i) maintain a substantial tension in each single thickness steel strip while it is being wound onto master spool 25; (ii) unwinding the starting spools 12, 14, 16, 18 and 20 at an optimal speed without requiring all unwinding forces to be transmitted through the single-thickness steel strip; It turns out that it does.

Master spool 25 with desired amount of steel strip
Once wound onto master reel 24, master reel 24 is removed from drive spindle 28 and stored for later use. To enable removal of the master spool 25, the single thickness steel strips 29a-29e are suitably cut at a location adjacent to the master spool 25 immediately prior to removal.

After the first master spool 25 is formed as described above and then removed from the drive spindle 28, other master spools 25 are similarly formed on the drive spindle 28. When each master spool 25 is completed, it is removed to allow the formation of the next master spool 25. Thereafter, the four master spools 25 are placed on the four unwinding reels 50 of the core manufacturing apparatus shown in FIG.

Further, as shown in FIG. 7, the multilayer steel strips 53 of the four master spools 25 are unwound from each master spool 25 and combined to form a composite steel strip 55. This composite steel strip 55 has a steel strip thickness equal to the total number of single layer steel strips of all master spools 25 shown in FIG. According to the illustrated embodiment, each multilayer steel strip 53 of each master spool 25 has a thickness of 5 layers, so the thickness of the composite steel strip 55 is 4×5=20 layers thick. .

[0035] When unwinding from the four master spools 25 and entering the location where they are combined to form the composite steel strip 55,
Each multilayer steel strip 53 in FIG.
, and then onto guide rollers 74 that change the orientation of each multilayer steel strip 53 from generally vertical to generally horizontal. After passing above the guide roller 74, the multilayer steel strip 53 is fed in a gradually converging relationship to form the composite steel strip 5.
It becomes 5. The portion of each multilayer steel strip 53 between the associated master spool 25 and guide roller 74 is located in a pit 76.
Hanging as loops placed within. The weight of the multilayer steel strip 53 in this loop is such that the weight of the multilayer steel strip 53 is
5, a tensile force is applied to the multilayer steel strip 53. As a result, each multilayer steel strip 53 is held in a tensioned state upstream from the point where each multilayer steel strip 53 is joined to another multilayer steel strip 53, and the composite steel strip 55 is wrinkled.
and other irregularities.

[0036] The composite steel strip 55 is attached to a pair of clamp members 58.
and 60, the steel strip is advanced to the right in FIG. These clamp members 58 and 60 can be moved toward and away from each other and are movable together in a horizontal direction. In FIG. 7, the clamp members 58 and 60 are at their left end positions and the composite steel strip 5
5 is shown at the minimum gap position where it is held between its upper and lower surfaces. As clamp members 58 and 60 move to the right from their FIG.

[0037] To cooperate with the strip feeding means 57 there is another strip feeding means 70 located downstream of the blades 62 and 64. When this downstream steel strip feeding means 70 is actuated, the clamping members 58 and 60 of the first steel strip feeding means 57 are moved away from each other to release the composite steel strip 55 and to the left to the initial position in FIG. move together. Steel strip feeding means 70
When the composite steel strip 55 is properly positioned by moving further to the right, the composite steel strip 55 is released in the same manner, and as shown in FIG.
Return to the left to the starting position.

To control the unwinding of the master spool 25 of the apparatus of FIG. 7, each unwinding roller 50 is coupled to the rotor of an electric motor 80. As the composite steel strip 55 is fed to the right, the electric motor 80 rotates the associated unwind reel 50 counterclockwise to provide the composite steel strip 55 with an unwound multilayer steel strip. As mentioned above, in the pit 76 below each master spool 25,
The multilayer steel strip 53 unwound from each master spool 25 hangs down to form a loop. Each of the individual steel strips forming the multi-layer steel strip 53 also hangs down into its own loops, the vertical spacing between these loops becoming progressively larger as the associated master spool 25 unwinds. A photoelectric controller 81 for each multi-layered steel strip 53 is disposed within or adjacent to the pit 76 to detect the lowest loop 75 of each multi-layered steel strip 53 to detect (i) the loop 75 rises above the scheduled upper limit, the electric motor 80 associated with the multilayer steel strip 53 is started to unwind the multilayer steel strip 53 at a gradually increasing speed, and (ii
) When the loop 75 falls below the predetermined lower limit, the electric motor 80 is decelerated and stopped rotating.

As can be seen with reference to FIG. 7, the two steel strip feeding means 57 and 70 intermittently advance the composite steel strip 55 to the right as they move to the right. As a result, the horizontal portion of the multilayer steel strip 53 is intermittently advanced to the right. Thus, as the horizontal portion of the multilayer steel strip 53 is intermittently advanced to the right, the master spools 25 are unwound by their respective electric motors 80 to form a loop. From these loops, the multilayer steel strip 53 is pulled by strip feeding means 57 and 70 and joined into a composite steel strip 55. During these operations, the horizontal portion of each multilayer steel strip 53 is held under tension by the weight of the loop 75 within the pit 76.

When the composite steel strip 55 of FIG. 2 is advanced to the desired position to the right, the shear blades 62 and 64
It is disconnected by the action of . These shear blades 62
and 64 are preferably constructed as shown in U.S. Patent Application No. 334,248, filed April 6, 1989.

Shear blades 62 and 64 cut composite steel strip 55 into composite steel strip sections having a desired length. These composite steel strip sections are shown in FIGS. 1 and 2 as described above.
constitutes a steel strip group 120. A plurality of steel strip groups 120 are suitably stacked to form the packet shown in FIGS. 1 and 2. An automated method for forming a packet from such a plurality of strips 120 is disclosed in U.S. Patent Application No. 463,697, filed January 11, 1990.

When the above press pooling process is used to produce composite steel strips to form composite steel strip sections or groups of steel strips 120, the steel strips within each group of steel strips 120 are:
It has been found that even when substantially dry, the adhesive adheres to the juxtaposed steel strips as if it were present between the juxtaposed steel strips. This adhesion effect makes it possible to produce cohesive steel strip groups and cohesive packets in which the steel strips adhere to each other in exactly the same way as when the conventionally used perchlorethylene is present.

This adhesion effect appears to be significantly influenced by the manner in which the surfaces of the juxtaposed steel strips are seated together. If the above juxtaposed steel strips are adjacent in the same spool,
or the multiple high spots that often exist along the width of the strip if manufactured from closely spaced sections.
spots) tend to line up. This tendency appears to hinder achieving the adhesion effect between juxtaposed steel strips that is found to be highly desirable. The pre-spooling process reduces the possibility that the high spots will line up and interfere with the adhesion effect. Transfer of Packets 110 to Belt Nester 28 Each packet, constructed and assembled as described above, is transferred by suitable means to a position on the upper run of conveyor belt 200 (see FIG. 3). Conveyor belt 200 revolves around two spaced apart pulleys 202 and 204 that are rotatable about a fixed axis. Pulley 202 is a drive pulley coupled to the rotor of an electric motor (not shown) controlled by suitable means, and the other pulley 204 is an idler pulley.

Below the conveyor belt 200 are a plurality of stationary permanent magnets 205 that assist in the movement of packets onto the conveyor belt 200 by providing a biasing force that attracts the packets toward the conveyor belt 200 . When the packet is properly secured to the upper surface of the conveyor belt 200, the conveyor belt 200 is advanced in the direction of arrow 206, and the leading end of the packet is placed on the guide plate 165.
move upward, and then the upper front roller 142 and the hub 131
gradually rises to a position between Thereafter, the arbor 130 is rotated counterclockwise as described above to perform winding.

Looking laterally to the conveyor belt 200, fixed guides 207 and 2 are provided to ensure that the packets are properly seated on the conveyor belt 200 in the correct orientation.
08 are provided against the side edges of the packet. As can be seen with reference to FIG. 8, these fixed guides 207 and 208 are attached to the upper surface of a fixed frame 209 disposed below the upper running portion of the conveyor belt 200. The guiding or inner surface of the fixed guide 207 is arranged substantially flush with the inner surface of the guide (or nesting) flange 134 . The guide surface of the fixed guide 208 is the guide (or nesting) flange 13
It is arranged substantially flush with the inner surface of 6. The fixed guides 207 and 208 enter the U-shaped space 137 between the guide flanges 134 and 136 of the arbor 130 and are correctly oriented when the packets are fed into the belt nester by the conveyor belt 200. Avoid skewing or multi-stepping as it is wrapped around.

Fixed guides 207 and 208 are provided to enable the conveyor to accept steel strips of different widths when it is desired to construct a transformer core formation having a width different from that of the illustrated core formation. is attached to a fixed frame. For transformer core formations of different widths as mentioned above, different arbors 130 with optimally adjusted spacing between the guide flanges are likewise adopted. Steel Strip Length Control Means As described above, the length of each steel strip portion cut from the composite steel strip 55, that is, the steel strip group 120, is determined by the length of the steel strip group 120 when the steel strip group 120 is wound around the arbor 130. The ends must be controlled so that they overlap by an appropriate amount. This length is controlled by controlling the distance that composite steel strip 55 is advanced past blades 62 and 64 before the cut is made by blades 62 and 64. Said advancement of the composite steel strip 55 is effected by strip feeding means 70 (see FIG. 7) which includes suitable means (not shown) for controlling the stroke. During core formation, after each packet is wrapped around the hub of the belt nester, the joints formed at each end of the packet are monitored to determine overlap in the group of joints. If this overlap is not within the predetermined limits, an error signal is supplied to the controller which causes the strip feeding means 70 to adjust its stroke and thus the length of the strip to be cut. Optimize the length of the next part. These monitoring and stroke adjustments can be made either by an operator or by suitable photoelectric control means (not shown). The fitting is visible through the window 135 in the guide flange 134.

[0047] Having the ability to adjust the length of the steel strip group as winding progresses is extremely advantageous as it allows for compensation for unpredictable variations in joint overlap that may occur as winding progresses. You should understand that. This advantage is not present in methods where all the steel strip is cut to a predetermined length before wrapping. This type of method is
U.S. Pat. No. 4,734,975 showing that steel strip is produced by radially cutting a pre-wound ring.
and US Pat. No. 4,741,096.

While specific embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made thereto without departing from the invention. therefore,
Such variations fall within the scope of the invention.

[Brief explanation of the drawing]

1 is a side view of one of a plurality of packets of amorphous steel strip used to carry out the method of the invention; FIG.

FIG. 2 is a top view of the packet shown in FIG. 1;

3 is a schematic side view of a belt nester used to make core formations from a plurality of packets of the type shown in FIGS. 1 and 2; FIG. In the figure, one of the plurality of guide flanges of the belt nester is shown partially broken.

4A is a cross-sectional view taken along line 4-4 in FIG.
B is an enlarged view of a portion of FIG. 3 without omitting the guide flange.

FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 4B.

FIG. 6 is a schematic diagram of a press spooling machine in which single-thickness amorphous steel strip is unwound from five starting spools and combined into a multi-thickness steel strip that is wound onto a master spool.

[Fig. 7] Multi-thickness steel strips unwound from four master spools received from the press spooling machine of Fig. 6 are combined to form one composite steel strip, and this composite steel strip is sent out to a predetermined size. FIG.

FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 3;

[Explanation of symbols]

110 packet 112 Amorphous steel strip 120 Steel strip group 128 Belt nester 130 Arbor 131 Hub 134,136 Guide flange 140 Belt

Claims (15)

[Claims] 1. (a) forming a composite steel strip consisting of multiple layers of superimposed amorphous steel strips, and (b) cutting the composite steel strip to form a plurality of multilayer composite steel strip sections. (c) forming steel strip groups from the composite steel strip sections, each steel strip group consisting of one or more composite steel strip sections, and all the composite steel strips in each steel strip group comprising: (d) having a plurality of substantially aligned longitudinally extending edges and substantially aligned transversely extending edges at opposite ends of the group of steel strips; forming packets, each packet comprising a plurality of steel strips, all of the steel strips within each packet having substantially aligned longitudinally extending side edges and longitudinally extending edges at opposite ends of the packet; (e) (i) a rotatable arbor; and (ii) an overlapping relationship as said arbor is rotated; and feeding the packets one after another into a belt nester comprising winding means including a belt extending around the arbor in order to wrap the packets around the arbor, thereby creating a core formation around the arbor. A method of manufacturing a transformer core consisting of an amorphous steel strip wrapped around a core window, the process comprising: 2. The composite steel strip comprises: (a) supplying a plurality of reels of amorphous steel strip; and (b) unwinding the amorphous steel strip from the plurality of reels, and the amorphous steel strips being juxtaposed are different. 2. The method of claim 1, further comprising the step of combining unwound amorphous steel strips to form the composite steel strip as it is unwound from a reel. 3. (a) supplying a plurality of reels of amorphous steel strip; (b) unwinding the amorphous steel strip from the plurality of reels, such that the amorphous steel strips juxtaposed are unwound from different reels; (c) cutting the composite steel strip to form a plurality of multilayer composite steel strip parts; (d) A process of forming a plurality of steel strip groups from the above composite steel strip sections, wherein each steel strip group consists of one or more composite steel strip sections, and all the composite steel strips in each steel strip group are substantially (e) (i) a rotatable arbor; (e) (i) a rotatable arbor; (ii) as said arbor is rotated, said steel strips are placed into a belt nester comprising winding means comprising a belt extending around said arbor for wrapping said steel strips around said arbor in overlapping relation; feeding a group of bands, thereby creating a core formation around said arbor. 4. A method as claimed in claim 1 or 3, wherein the steel strips are kept substantially dry before being wound around the arbor by the winding means. 5. (a) supplying a plurality of spools wound with single-layer-thick amorphous metal bands, and (b) simultaneously unwinding and combining the single-layer-thickness metal bands from the plurality of spools. (c) forming a plurality of master reels wound with metal strips having the multilayer thickness; (d) forming a metal strip having the multilayer thickness from the plurality of master reels; (e) cutting said composite metal strip; (f) forming a plurality of metal band groups from the composite metal band parts, each metal band group consisting of one or more composite metal band parts; all of the composite metal strips within each metal strip group have substantially aligned longitudinally extending edges and substantially aligned transversely extending edges at opposite ends of the metal strip group; (g) forming a plurality of packets from said groups of metal strips, each packet consisting of a plurality of groups of metal strips, wherein all the groups of metal strips in each packet are substantially aligned vertically; (h) (i) a rotatable arbor; (h) (i) a rotatable arbor; (h) (i) a rotatable arbor; ) feeding the packets sequentially into a belt nester comprising winding means including a belt extending around the arbor for winding the packets on the arbor in an overlapping relationship as the arbor is rotated; thereby creating a core formation around said arbor. 6. The cutting step (e) of claim 5 is such that the length of the plurality of composite metal strips is such that when each packet is wound around the arbor, the length of each composite metal strip is equal to the length of the opposite end of each group of metal strips in the packet. 6. The method of claim 5, wherein the lengths are controlled such that the portions meet in overlapping relationship. 7. In each of the packets, when the packet is wound around the arbor, the tip of each metal band group that is radially outward from the innermost metal band group in the packet is the same as that of the immediately preceding metal band group. 7. The method of claim 6, wherein successive metal strips in the packet are staggered by an amount such that they are disposed closely to the rear end. 8. Each packet to be wound subsequent to the wrapping of the innermost packet is positioned at the beginning of the winding operation of each packet so that its leading edge overlaps the trailing edge of the immediately preceding packet. 8. The method according to claim 7. 9. (a) supplying a plurality of reels wound with multi-layer thick amorphous steel strips; (b) unwinding and combining the multi-layer thick steel strips from the plurality of reels; forming a composite steel strip having a thickness equal to the sum of the combined plurality of multi-thickness steel strips; and (c) cutting the composite steel strip to form a plurality of composite steel strip sections. and (d) forming a plurality of steel strip groups from the composite steel strip sections, each steel strip group consisting of one or more composite steel strip sections, and wherein all the composite steel strips in each steel strip group are formed. (e) a strip having substantially aligned longitudinally extending edges and substantially aligned transversely extending edges at opposite ends of said strips; forming a plurality of packets from the packet, each packet comprising a plurality of steel strips, all of the steel strips in each packet having substantially aligned longitudinally extending side edges of the packet; (f) (i) a rotatable arbor; (ii) as the arbor is rotated; sequentially feeding the packets into a belt nester comprising winding means including a belt extending around the arbor in order to wrap the packets around the arbor in an overlapping relationship, thereby forming a core around the arbor; A method of manufacturing a transformer core comprising an amorphous steel strip wrapped around a core window. (a) the rotatable arbor is (
i) a rotatable hub having a circumference around which the packet is wrapped as the arbor rotates; and (ii)
fixed to the hub on opposite sides on the longitudinal axis of the hub and projecting radially outwardly beyond the outer periphery of the hub, with opposite edges of the packet substantially aligned;
(b) the winding means has a pair of flanges that cooperate with both side edges of the packets that have entered the hub so as to forcibly seat the plurality of packets that have entered the outer peripheral region of the hub; two front rollers that engage the belt and guide the belt in close contact with an outer periphery of the hub or a core formation formed on the outer periphery of the hub; separated from each other by a gap and disposed between the pair of flanges, one front roller engages the belt when the belt enters the outer circumferential area of the hub, and the other front roller engages the belt when the belt enters the outer peripheral area of the hub. (c) after passing through the gap, the packet engages the belt in the area where the belt engages the one front roller; 10. A method according to any one of claims 1, 3, 5 or 9, wherein the hub is fed onto the outer circumference of the hub via a passage between the outer circumference of the hub and the belt. (a) When each packet enters between the belt and the outer periphery of the rotating hub within the area of the one front roller, the packet adjacent to the both side edges (b) the packet is between the belt and the outer periphery of the hub within the area of the one front roller; 11. The method of claim 10, wherein a radially inwardly directed force of the hub is applied to an outer surface of the packet adjacent opposite edges of the packet, thereby counteracting the tendency to curl. 12. Said radially inwardly directed force is applied by a retraction roller acting on said packet adjacent said opposite edges of said packet.
Method described. 13. The radially inwardly directed force is applied by a retraction roller coupled to the one front roller and acting on the packet adjacent the opposite edges of the packet. Method described. 14. (a) the belt has a width substantially less than the width of each packet; (b) the belt engages each packet at the center of each packet; (c) 14. The method of claim 13, wherein the retraction roller is located laterally outward of the belt and proximate the flange. 15. A spacing between each of the retraction rollers and the flange adjacent thereto is about 0.254 mm.
~1.27mm (=0.01 inch ~ 0.05 inch)
15. The method of claim 14 within the scope of.