WO2020093589A1

WO2020093589A1 - Transformer laminated core and preparation method therefor

Info

Publication number: WO2020093589A1
Application number: PCT/CN2019/071111
Authority: WO
Inventors: 王永法
Original assignee: 王永法
Priority date: 2018-11-09
Filing date: 2019-01-10
Publication date: 2020-05-14
Also published as: CN109346289A; CN109346289B

Abstract

A transformer laminated core, which comprises columns (1, 2, 3) respectively positioned at the left, right and center, and yokes (4, 5) respectively positioned at the upper and lower sides. Column cross-sections and yoke cross-sections of the core are polygons composed of rectangles and trapezoids of a plurality of levels, the rectangles are positioned in the middles of the polygons, the trapezoids of a plurality of levels are positioned on both sides of the long sides of the rectangles, and the bottom edges of the trapezoids on each side are sequentially connected to each other and then connected to the long sides of the rectangles. The lengths of the adjacent bottom edges of trapezoids of two adjacent levels in the column cross-section and the yoke cross-section are different, and the more proximate the trapezoid is to the rectangle, the longer the length of the bottom edge of the trapezoid is; the area of the yoke cross-section is greater than that of the column cross-section. Also provided is a preparation method for the transformer laminated core. Compared with the prior art, the laminated core has a high filling rate and low power loss, and a fewer number of replacements of trapezoidal silicon steel strips is required during a preparation process, so that the production efficiency is improved and the costs are reduced.

Description

Transformer stacked iron core and preparation method thereof

Technical field

The invention belongs to the technical field of transformer parts, and in particular relates to a laminated iron core of a transformer and a preparation method thereof.

Background technique

At present, the structure of the transformer core is divided into lamination type and winding type. The lamination transformer core is formed by stacking multi-level silicon steel sheets with different widths. The outline cross section of the core column or yoke is a step composed of several levels of rectangles Round (as shown in Figure 1), stepped oval or stepped oval structure. For example, the utility model patent application number CN00212756.3 "A Distribution Transformer" (authorization announcement number CN2431630Y), the utility model patent application number CN201420803446.3 "A new three-phase five-column large-capacity transformer core The core structure of the transformer disclosed in "Structure" (authorization bulletin number CN204257346U) is laminated.

In the design of existing transformers, how to design the cross-section of the iron core is a very important link, which is related to the use effect and production cost of the entire transformer. To this end, the application patent for the invention patent CN201110000854.6 "Optimal Design Method for the Cross Section of the Core Post of the Power Transformer" (authorization bulletin number CN102208274B) solves the design of the optimal core cross section through programming, which frees the manual solution and improves the calculation speed, but There is no substantial improvement in the core cross section from the structure, and the ideal filling factor is not achieved.

Since the cross section of the laminated core is a stepped structure, generally at least 7 steps are required to make the filling rate of the core in the coil meet the requirements for use. In this way, 7 to 18 types of silicon steel sheets need to be cut during processing. When one type of silicon steel sheets are stacked, another type of silicon steel sheets need to be replaced for stacking. This cycle repeats the operation until All silicon steel sheets are stacked to make an iron core. The cross-sectional coefficient of the manufactured core is only 90.5 to 93%, and the filling rate is low; and the silicon steel sheet needs to be continuously replaced during the preparation process, resulting in low production efficiency.

In order to overcome the above defects, the invention patent application with the application number CN201710981565.6, "An iron core structure and its shearing and assembling method for improving the filling rate of the iron core" (application publication number CN107658110A) uses a multi-level trapezoid to form a polygonal core cross section , Effectively improve the filling rate of the core and reduce the cost of the core, but according to its description "the length of the adjacent bottom edge of the two adjacent trapezoids in the core section or yoke section is the same" and combined with the description of the embodiment, those skilled in the art will know The manufacturing process of the iron core is to use a trapezoidal silicon steel sheet to cut the core section of only one post or yoke, so that the cutting of the two side columns, middle column, upper and lower iron yokes of the first-level trapezoid needs to be replaced by 5 trapezoidal sheets , Resulting in low manufacturing efficiency, can not meet the needs of automatic cutting and stacking table. Especially with the continuous adoption of automatic iron core production equipment, the time for replacing silicon steel sheets on the equipment will be several times more than the shearing time. If there are many specifications of silicon steel sheets, a lot of time will be wasted on replacing silicon steel sheets , Which greatly reduces the production efficiency of automated equipment.

Summary of the invention

The first technical problem to be solved by the present invention is to provide a transformer lamination core with a high filling rate and a low power loss in view of the current state of the art.

The second technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned transformer laminated iron core in order to reduce the number of replacements of trapezoidal silicon steel sheets, thereby improving production efficiency and reducing costs.

The technical solution adopted by the present invention to solve the above first technical problem is as follows: a transformer laminated iron core includes pillars located on the left, right, and center, and yokes located on the upper and lower sides respectively. A polygon consisting of a rectangle and several stages of trapezoids, the rectangle is located in the middle of the polygon, the trapezoids of each stage are located on both sides of the long side of the rectangle, and the bottom sides of the trapezoids on each side are successively connected to the long side of the rectangle; It is characterized in that the lengths of the adjacent bottom edges of the two adjacent trapezoidal trapezoidal sections in the column section and the yoke section are different, and the closer to the rectangular trapezoid, the larger the bottom edge length; and the area of the yoke section is larger than the area of the column section .

In order to further increase the filling rate and reduce the loss, the cylindrical cross-section or / and the yoke cross-section of the core is preferably a circular or oblong or elliptical inscribed polygon.

The core is preferably a three-phase three-pillar structure.

The technical solution adopted by the present invention to solve the above-mentioned second technical problem is as follows: a method for preparing the transformer laminated core as described above, which is characterized by comprising the following steps:

1. Make the first-level core corresponding to the first-level trapezoid at the bottom of the polygon in the column cross-section and the yoke cross-section: cut the silicon steel sheet coil longitudinally at a desired angle to the length to obtain the first-level trapezoidal silicon steel strip; Starting from the small end of the first-level trapezoidal silicon steel strip, the horizontal cutting is performed in sequence along the length of the first-level trapezoidal silicon steel strip. The cutting sequence is the same number of left and right pillars, middle pillars and Bottom and upper yoke sheet to obtain multiple silicon steel sheets of first-level core; stack the multiple silicon steel sheets of first-level core from small to large in a single or multiple groups at a time, the stacking order is left, The right column piece, the middle column piece and the upper and lower yoke pieces make a first-level iron core;

2. Make the second-level iron core corresponding to the second-level trapezoid in the column section and the yoke section: cut the silicon steel sheet coil longitudinally at a desired angle to the length direction to obtain the second-level trapezoidal silicon steel strip. The width of the small end of the trapezoidal silicon steel sheet is the width of the large end of the first-stage trapezoidal silicon steel sheet after cutting the last upper yoke in step one; the small end of the second-stage trapezoidal silicon steel sheet is the starting end. Cut horizontally along the length direction of the second-level trapezoidal silicon steel strip, the cutting sequence is the same as the cutting sequence in the above step 1, to obtain multiple silicon steel sheets of the second-level core; the multiple silicon steel sheets of the second-level core are in the first level On the basis of the iron core, lamination is carried out in a single piece or multiple pieces at a time according to the size from small to large, and the lamination sequence is the same as the lamination sequence in the above step 1, to obtain a secondary core, the column section and the yoke of the secondary core The cross section is the second-level trapezoid above the first-level trapezoid and adjacent to the first-level trapezoid;

3. According to the rules of

steps

1 and 2 above, make the cores corresponding to the trapezoids of the subsequent required number of stages on the rectangular side of the column section and yoke section until the N-level core is obtained, the column section and the yoke of the N-level core The cross-section is the Nth-level trapezoid located above and adjacent to the N-1th-level trapezoid; where N is a natural number greater than or equal to 2;

4. Make the intermediate cores corresponding to the rectangles in the column section and the yoke section: rectangular silicon steel strips are longitudinally cut on the silicon steel sheet coil according to the size of the transformer core stack; the width of the rectangular silicon steel strips is N after cutting in step three The width of the large end of the N-level trapezoidal silicon steel strip after the first upper yoke in the grade core; starting from one end of the rectangular silicon steel strip, cut a number of the same amount laterally along the length of the rectangular silicon steel strip The left and right pillar pieces, the middle pillar piece and the upper and lower yoke pieces, to obtain a plurality of silicon steel sheets of the middle-level core; stack the plurality of silicon steel sheets of the middle-level core on the basis of the N-level core obtained in the above step three The lamination sequence is the same as the lamination sequence in step 1 above, to produce an intermediate level core, that is, an N + 1 level core;

Fifth, the N + 2 level core corresponding to the N + 2 level trapezoid on the other side of the rectangle in the above column section and yoke section is made: the silicon steel sheet coil is longitudinally cut at a desired angle to the length direction to obtain The N + 2 level trapezoidal silicon steel strips of the same specification, the N + 2 level trapezoidal silicon steel strips with the same specifications, starting from the small end of the N + 2 level trapezoidal silicon steel strips, along the Cut horizontally in order in the length direction, the cutting sequence is the same as the cutting step in the above step 1, to obtain multiple silicon steel sheets of N + 2 grade core; multi-piece silicon steel sheets of N + 2 grade core on the basis of N + 1 grade core The size is from large to small, one piece or multiple pieces are stacked at a time, and the lamination sequence is the same as the lamination sequence in the above step 1, to obtain an N + 2 grade core;

Sixth, make the N + 3 level core corresponding to the N + 3 level trapezoid located on the other side of the rectangle in the above column section and yoke section: cut the silicon steel sheet coil longitudinally at a desired angle to the length direction, and obtain N-1 level trapezoidal silicon steel strips The same specifications of N + 3 level trapezoidal silicon steel strips, starting from the small end of the N + 3 level trapezoidal silicon steel strips, along the N + 3 level trapezoidal silicon steel strips The longitudinal direction of the strip is cut horizontally in sequence, and the cutting sequence is the same as the cutting step in the above step 1, to obtain multiple silicon steel sheets of the N + 3 grade core; the multiple silicon steel sheets of the N + 3 grade core are based on the N + 2 grade core Lamination according to the size from large to small single piece or multiple pieces at a time, the lamination sequence is the same as the lamination sequence in the above step 1, to obtain an N + 3 grade core, the column cross section of the N + 3 grade core and The yoke cross section is the N + 3 stage trapezoid above the N + 2 stage trapezoid and adjacent to the N + 2 stage trapezoid;

7. According to the rules of

steps

5 and 6 above, make the cores corresponding to the trapezoids of the subsequent required stages in the column section and the yoke section on the other side of the rectangle until a 2N + 1 level core is obtained, that is, a complete transformer is made Stacked core, the column section and yoke section of the 2N + 1-level core are the 2N + 1-level trapezoids located above and adjacent to the 2N-level trapezoid;

The above-mentioned horizontal cutting adopts the cutting method of the positive and negative knives at a desired angle with the longitudinal direction.

In order to improve production efficiency, as an improvement, trapezoidal silicon steel sheet strips of the same specification can be cut by stacking silicon steel sheet coils up and down. Since the lengths of the adjacent bottom edges of the two adjacent trapezoidal trapezoidal sections in the column section and the yoke section are different, even if there is a slight difference in the trapezoidal silicon steel strip after cutting, it will not affect the subsequent cutting and stacking.

In order to improve the lamination efficiency and precision quality, the silicon steel sheet is laminated on the core stacking table, each silicon steel sheet is provided with at least one positioning hole, and the core stacking table is provided with a wearable Positioning rod for positioning and stacking silicon steel sheets through positioning holes.

Preferably, the order of cutting the left and right pillars is to cut at least three left pillars first, and then cut the right pillars equal to the number of left pillars; or cut one left pillar first, and then cut one right pillar, Then cut a left column, and repeat this process, cutting at least three left columns and the right column with the same number as the left column.

Finally, the order of cutting the lower and upper yokes is to first cut a number of lower yokes with the same number as the left column, and then cut a number of upper yokes with the same number of lower yokes; or cut a lower yoke and then Cut an upper yoke piece, and then cut a lower yoke piece, and so on, after cutting the same number of lower yoke pieces as the left column piece and the same number of upper yoke pieces as the lower yoke piece.

In the above method, the cutting of the trapezoidal silicon steel sheet strip is achieved by a cutting device. Preferably, the cutting device includes a conveying track for carrying the trapezoidal silicon steel sheet strip. Of the trapezoidal silicon steel sheet to limit the two feed limiters, and at the same time is also equipped with an adjustment mechanism that can adjust the distance between the two feed limiters, so that the two feed limit The distance between the position pieces can be continuously adjusted according to the width of the trapezoidal silicon steel sheet, so that the trapezoidal silicon steel sheet is located along the central axis of the conveying track, that is, no deviation occurs.

The above-mentioned adjustment mechanism can adopt various structures, which can move the two film-restricting pieces relatively or away from each other. Preferably, the adjustment mechanism includes a screw rod with opposite thread directions at both ends and driving the screw rod to rotate Of the motor, the two feed limiters are respectively threaded at the two ends of the screw rod, and are provided with only allowing the two feed limiters to move along the axis of the screw rod with the rotation of the screw rod Guiding structure.

With this kind of equipment, a long trapezoidal silicon steel sheet can be cut into two side posts, middle posts and upper and lower yokes in the desired stage to reduce the number of replacements of trapezoidal silicon steel sheets and improve production efficiency. Reduce the cost, and can ensure the accuracy of the cut size, which is more conducive to improving the quality of the laminated iron core of the transformer.

Compared with the prior art, the advantages of the present invention are:

1. The two side posts, middle post, and upper and lower yokes in the first stage of the core of the invention are cut from a trapezoidal silicon steel sheet, so the specifications of the trapezoidal silicon steel sheet are less, which is the prior art The specifications of the trapezoidal silicon steel strips to be used are less than half of the specifications. In this way, the number of replacement of silicon steel strips is greatly reduced, and the production efficiency is improved;

2. Because the number of silicon steel sheet replacements of the present invention is greatly reduced, it is suitable for automated iron core production equipment, which can greatly reduce manufacturing costs and labor costs, and can also improve lamination efficiency and quality, and reduce manual handling and lamination processes. At least 5% loss to the core;

3. Since the two side pillars, the middle pillar, and the upper and lower yokes of the present invention are stacked on a trapezoidal silicon steel sheet cyclically, the cross-sectional area of the yoke is slightly larger than the cross-sectional area of the column, which can reduce the core loss at least 1%; and compared with the existing core, the core section coefficient of the present invention is higher, up to 93-98%, and the utilization rate of the material is increased by more than 10%.

BRIEF DESCRIPTION

1 is a cross-sectional view of a column of a laminated transformer core in the prior art;

2 is a schematic diagram of the positions of the left and right columns, the center column, the upper and lower yokes in Embodiment 1 of the present invention;

Figure 3 is a cross-sectional view taken along line E-E in Figure 2;

4 is a schematic structural diagram of a rectangular silicon steel sheet in Example 1 of the present invention;

5 is a schematic structural diagram of a first-stage trapezoidal silicon steel sheet in Embodiment 1 of the present invention;

6 is a schematic diagram of the cutting sequence of the left and right pillar pieces, the middle pillar piece, and the upper and lower yoke pieces in Embodiment 1 of the present invention;

7 is a partial schematic diagram of an apparatus for cutting the trapezoidal silicon steel sheet shown in FIG. 6;

FIG. 8 is a schematic view of the C-C structure in FIG. 7;

9 is a cross-sectional view of a column of a laminated iron core of a transformer in Embodiment 2 of the present invention;

10 is a schematic diagram of the cutting sequence of the left and right pillar pieces, the middle pillar piece, and the upper and lower yoke pieces in Embodiment 2 of the present invention;

11 is a cross-sectional view of a column of a laminated iron core of a transformer in Embodiment 3 of the present invention.

detailed description

The present invention will be described in further detail below with reference to the embodiments of the accompanying drawings.

Example 1:

As shown in Figures 2 to 6, it is the first embodiment of the transformer laminated core of the present invention and its preparation method. The laminated core of the transformer is a three-phase three-pillar core structure, as shown in Figure 2, including the left and right , The middle column (ie left column 1, right column 2, middle column 3) and the upper and lower yokes (ie upper yoke 4 and lower yoke 5).

Among them, the column section and the yoke section of the iron core are polygons composed of the middle-level rectangle A and several stages of trapezoids B. As shown in FIG. Not shown in the figure, but also a circle inscribed in a hexagon, the rectangle A is located in the middle of the polygon, and the trapezoids B at each level are located on both sides of the long side of the rectangle A. In this embodiment, the upper and lower sides of the rectangle A are respectively There are three-level trapezoid B, so the upper and lower three-level trapezoid B and the middle-level rectangle A form a seven-level structure of the core. From the bottom to the top, the cross-section of the first-level core is the first-level trapezoid B1 and the cross-section of the second-level core is The section of the second-level trapezoid B2, the third-level core is the third-level trapezoid B3, the section of the fourth-level core is the rectangle A, the section of the fifth-level core is the fifth-level trapezoid B5, and the section of the sixth-level core is the first The cross-section of the six-level trapezoid B6 and seven-level core is the seventh-level trapezoid B7, and the bottom sides of the trapezoid B on each side are connected to the long side of the rectangle A in sequence, and the adjacent two levels of the column cross-section and the yoke cross-section The length of the adjacent bottom edge of trapezoid B is slightly different, and the closer to the ladder of rectangle A The larger the base length B; different cross-sectional area of each of the yoke and the column section, and the yoke sectional area slightly larger than the area of the column cross-section.

The preparation method of the above-mentioned transformer laminated core includes the following steps:

1. Make the first-level core corresponding to the first-level trapezoid in the column cross-section and the yoke cross-section: place the silicon steel sheet coil to be cut on the unwinding rack of the automatic cutting line, and place the silicon steel sheet according to the size of the transformer's stacked iron core The coil material is longitudinally cut at a desired angle to the length direction to obtain a first-level trapezoidal silicon steel sheet strip, as shown in FIG. 5; starting from the small end of the first-level trapezoidal silicon steel sheet strip 200, along the first The horizontal direction of the trapezoidal silicon steel strip 200 is sequentially cut horizontally, and the cutting sequence is a number of left and right column pieces 11, 21, the middle column piece 31, and the lower and upper yoke pieces 51, 41 (the first level trapezoidal silicon steel sheet The width of the strip 200 increases along the length direction from the small end, because the cutting of the upper and lower yoke pieces 41, 51 is in order after the left and right post pieces 11, 21 and the middle post piece 31, thereby making the upper and lower yoke pieces 41 , 51 area is slightly larger than the left and right column pieces 11, 21 and the center column piece 31, which makes the area of the yoke section slightly larger than the area of the column section), punching two positioning holes X in each piece during the cutting process for the next step The positioning of multiple silicon steel sheets with a first-level core; A positioning rod that can pass through the positioning hole X is provided on the core stacking table for automatic lamination. The manipulator or other lamination device will perform the multi-piece silicon steel sheets of the first-level core according to the size from small to large. Lamination, the laminations are the left and

right column pieces

11, 21, the center column piece 31, and the upper and

lower yoke pieces

41, 51 in order to obtain a first-level core, the column section and the yoke section of the first-level core are located in a polygon The first trapezoid B1 at the bottom, as shown in Figure 3;

2. Make the second-level core corresponding to the second-level trapezoid in the column section and yoke section: cut the silicon steel sheet coil at a desired angle to the length to obtain the second-level trapezoid silicon steel strip (not shown in the figure) Out), the width of the small end of the second-stage trapezoidal silicon steel sheet bar is the width of the large-end end of the first-stage trapezoidal silicon steel sheet bar 200 after cutting the last upper yoke 41 in step one; The small head end is the starting end, and it is horizontally cut along the length direction of the second-level trapezoidal silicon steel strip. The cutting sequence is the same as the cutting sequence in step 1 above. Similarly, two positioning holes X are punched on each piece during the cutting process in order to Positioning of one-step process to obtain multiple silicon steel sheets of the second-level core; a manipulator or other lamination device will divide the multiple silicon steel sheets of the second-level core on the basis of the first-level core according to the size from small to large single or multiple pieces at a time Lamination is carried out (during lamination, accurate positioning and lamination can be achieved by passing the positioning hole X on each slice through the positioning rod, and the following steps are also operated in the same way). The lamination sequence is the same as the lamination sequence in step 1 above ,be made of As shown in Fig. 3, the column section and yoke section of the second-level core are the second-level trapezoid B2 located above and adjacent to the first-level trapezoid B1 (due to the second-level trapezoid silicon steel sheet The width of the starting end of the bar is the width of the first-stage trapezoidal silicon steel strip 200 after the last upper yoke 41 is cut, so that the second-stage trapezoid B2 and the first-stage trapezoid B1 in the column section and the yoke section are adjacent to the bottom The length of the sides is different, and the length of the lower bottom edge of the second-level trapezoid B2 is longer than the length of the upper bottom edge of the first-level trapezoid B1);

3. Making the third-level core corresponding to the third-level trapezoid in the column section and the yoke section: the silicon steel sheet coil is longitudinally cut at the required angle to the length direction to obtain the third-level trapezoid silicon steel sheet strip (not shown in the figure) Out), the width of the small end of the third-level trapezoidal silicon steel sheet is the width of the large-end of the second-level trapezoidal silicon steel sheet after cutting the last upper yoke in step two; The head end is the starting end, and it is horizontally cut along the length of the third-level trapezoidal silicon steel strip. The cutting sequence is the same as the cutting sequence in step one above. During the cutting process, two positioning holes X are punched in each piece for the next step. Positioning to obtain multiple silicon steel sheets of the three-level core; a manipulator or other lamination device stacks the multiple silicon steel sheets of the third-level core on the basis of the second-level core according to the size from small to large single or multiple sheets at a time The lamination sequence is the same as the lamination sequence in step 1 above, to produce a three-level core. As shown in FIG. 3, the column section and yoke section of the three-level core are located above the second-level trapezoid B2 and are Trapezoid B2 adjacent to the first Level trapezoidal B3, and the lower base of the trapezoid third stage B3 is longer than the length of the trapezoidal base length B2 of the second stage;

4. Make the four-level core corresponding to the rectangle in the column section and the yoke section: as shown in Figure 4, the silicon steel sheet coil is longitudinally cut into a rectangular silicon steel sheet strip 100, and the width of the rectangular silicon steel sheet strip 100 is cut in step three The width of the large end of the third-stage trapezoidal silicon steel strip after the last upper yoke; starting from one end of the rectangular silicon steel strip 100, cut a number of left sides of the same length along the length of the rectangular silicon steel strip 100 , The right column piece, the middle column piece and the upper and lower yoke pieces (because the rectangular silicon steel strip 100 has the same width at each place, there is no requirement for the cutting order of the left and right column pieces, the middle column piece, and the upper and lower yoke pieces. It can be designed according to the specific working conditions). During the cutting process, two positioning holes are punched in each piece for the positioning of the next step, and multiple silicon steel sheets with a four-level core (that is, an intermediate-level core) are obtained; the robot or other lamination device will The multiple silicon steel sheets of the first-level core are laminated on the basis of the above-mentioned three-level core. The lamination sequence is the same as the lamination sequence in the above step 1, to obtain a four-level core. The column section and yoke section of the four-level core are as described above Rectangular The length of A, and A rectangle is longer than the length of the third stage on the base of the trapezoid B2;

Fifth, the five-level core corresponding to the fifth-level trapezoid in the column section and the yoke section: the silicon steel sheet coil is longitudinally cut at a desired angle to the length direction to obtain the third specification of the third-level trapezoidal silicon steel strip Five-level trapezoidal silicon steel strip (not shown in the figure), starting from the small end of the fifth-level trapezoidal silicon steel strip as the starting end, cut horizontally along the length direction of the fifth-level trapezoidal silicon steel strip in the same order as above The cutting process in step one is sequenced. During the cutting process, two positioning holes X are punched in each piece for the positioning of the next step, and a multi-piece silicon steel sheet with a five-level core is obtained; a manipulator or other lamination device converts the multi-piece silicon steel with a five-level core. On the basis of the four-level core, the slices are stacked one at a time according to the size from large to small, or a group of multiple slices at a time. The stacking sequence is the same as the stacking sequence in the above step 1, to obtain a five-level core. The column section and the yoke section are the fifth-level trapezoid B5 located above the rectangle A and adjacent to the rectangle A, and the length of the lower base of the fifth-level trapezoid B5 is less than the length of the rectangle A;

Sixth, the six-level core corresponding to the sixth-level trapezoid in the column section and the yoke section: longitudinally cut the silicon steel sheet coil at a desired angle to the length direction to obtain the first specification of the second-level trapezoidal silicon steel strip Six-stage trapezoidal silicon steel strip (not shown in the figure), starting from the small end of the sixth-stage trapezoidal silicon steel strip as the starting end, cut horizontally along the length of the sixth-level trapezoidal silicon steel strip in sequence, the cutting sequence is the same as above The cutting process in step one is sequenced. During the cutting process, two positioning holes X are punched in each piece for the positioning of the next step to obtain a multi-piece silicon steel sheet with a six-level core; a manipulator or other lamination device will divide the multi-piece silicon steel with a six-level core. On the basis of the five-level core, the pieces are stacked one by one at a time according to the size from large to small, or a group of multiple pieces, and the lamination sequence is the same as the lamination sequence in the above step 1, to obtain a six-level core. The column section and the yoke section are the sixth-stage trapezoid B6 located above and adjacent to the fifth-stage trapezoid B5. The length of the lower bottom edge of the sixth-stage trapezoid B6 is shorter than the upper bottom edge of the fifth-stage trapezoid B5 length;

7. Making the seventh-level core corresponding to the seventh-level trapezoid in the column section and the yoke section: longitudinally cutting the silicon steel sheet coil at the required angle to the length direction to obtain the first specification of the same specifications as the first-level trapezoidal silicon steel sheet strip Seven-level trapezoidal silicon steel strip 300 (as shown in FIG. 5), starting from the small end of the seventh-level trapezoidal silicon steel strip 300 as the starting end, it is sequentially cut horizontally along the length of the seventh-level trapezoidal silicon steel strip 300, and then cut The order is the same as the cutting step in the above step one. During the cutting process, two positioning holes are punched in each piece for the positioning of the next step, and multiple silicon steel sheets of the seven-level core are obtained; the manipulator or other lamination device Based on the six-level iron core, the silicon steel sheet is laminated according to the size from large to small at a time, single or multiple at a time, and the lamination sequence is the same as the lamination sequence in the above step 1, to obtain a seven-level iron core. The column section and yoke section of the core are the seventh-stage trapezoid B7 located above the sixth-stage trapezoid B6 and adjacent to the sixth-stage trapezoid B6. The length of the lower base of the seventh-stage trapezoid B7 is shorter than that of the sixth-stage trapezoid B6. Bottom length; so, made Complete transformer core stack.

As shown in Fig. 6, the above-mentioned horizontal cutting adopts a positive and negative cutting method to improve the utilization rate of trapezoidal and rectangular silicon steel strips; the order of cutting left and

right pillars

11, 21 is to cut five left pillars first 11. After cutting five right pillar pieces 21; then cutting five middle pillar pieces 31; cutting the lower and

upper yoke pieces

51, 41 in order is to cut five lower yoke pieces 51 first and then five upper yoke pieces 41.

The equipment used when cutting the above-mentioned trapezoidal silicon steel strips and rectangular silicon steel strips includes a conveyor track 6 for carrying silicon steel strips (here the silicon steel strips are trapezoidal silicon steel strips, which may be rectangular silicon steel strips) and Two feed limiters 7, which are located on both sides of the conveying rail 6 to limit the conveyed silicon steel sheet strips, please refer to FIGS. 7 and 8, and the two ends of the conveying track are equipped to drive the silicon steel sheet strips forward (press 7 (the direction shown by the arrow in FIG. 7), the roller set (not shown in the figure), the cutting knife is placed on the worktable downstream of the stopper 7 so as to adjust the position through the two film advancement stoppers 7 The silicon steel sheet strip is cut into the left pillar piece 11, the right pillar piece 21, the middle pillar piece 31 and the lower yoke piece 51 and the upper yoke piece 41 as shown in FIG. 6. In order to adapt to the trapezoidal silicon steel sheet, the device is equipped with an adjustment mechanism that adjusts the distance between the two sheet-feeding limiters, so that the distance between the two sheet-feeding limiters 7 can Continuously adjust with the width of the cut trapezoidal silicon steel sheet strip, so that the conveyed silicon steel sheet strip is located on the conveying track along the direction of the central axis, that is, no deviation occurs. The adjustment mechanism can be implemented in many ways, but preferably, in this embodiment, the adjustment mechanism includes a screw rod 8 with opposite thread directions at both ends and a motor that drives the screw rod 8 to rotate, which is preferred A servo motor (not shown in the figure), two piece-feeding limiters 7 are respectively screwed to the two ends of the screw rod 8, and the two piece-feeding limiters 7 are respectively connected with a guide structure, the guide structure A guide rod distributed parallel to the screw rod can be used, and the two film advancement limiters are respectively threaded on the respective guide rods; or through the guide block and guide groove between the film advancement stopper and the frame of the cutting equipment Cooperate to realize that the two-piece limiting member can only move along the axis of the screw when the screw rotates. And since the thread direction of the two ends of the screw is opposite, when the screw rotates, the two-advancing piece limiter can only move relatively or along the axial direction of the screw, so that the two-advancing piece limiter can be adjusted The distance between them is reduced or increased to match the width of the trapezoidal silicon steel strip traveling there, and the position of the trapezoidal silicon steel strip on the conveyor track 6 is adjusted at any time to ensure the subsequent cutting quality To further improve the quality of the transformer core. When cutting the rectangular silicon steel strip, because the width of the rectangular silicon steel strip is constant, there is no need to adjust after the two film-restricting pieces are adjusted into position. Therefore, such a device can be used for cutting rectangular silicon steel strips and trapezoidal silicon steel strips at the same time.

Example 2:

As shown in FIGS. 9 and 10, it is Embodiment 2 of the transformer laminated core of the present invention and its preparation method. The structure and preparation method of the transformer laminated core in this embodiment are basically the same as Embodiment 1, except that in this embodiment, The column section and yoke section of the iron core are elliptical inscribed hexagons.

And as shown in FIG. 10, the order of cutting the left and

right pillars

11, 21 in this embodiment is to first cut a left pillar 11, then a right pillar 21, and then a left pillar 11, and so on, After cutting five left pillar pieces 11 and five right pillar pieces 21; then cutting five middle pillar pieces 31; the order of cutting the lower and

upper yoke pieces

51, 41 is to cut one lower yoke piece 51 first, and then one upper yoke piece Piece 41, and then cut one piece of lower yoke piece 51, in this way, five pieces of lower yoke piece 51 and five pieces of upper yoke piece 41 are cut.

Example 3:

As shown in FIG. 11, it is Embodiment 3 of the transformer laminated core of the present invention and its preparation method, which is basically the same as Embodiment 1, except that the column section and the yoke section of the iron core in this embodiment are oval inscribed sixteen Sides.

Of course, the laminated core of the transformer of the present invention is not limited to the structure disclosed in the above embodiments, and the number of stages of the core can be increased or decreased according to the design requirements, such as a three-level core structure, a five-level core structure, a nine-level core structure, ten One-level core structure, thirteen-level core structure, etc.

Claims

A laminated iron core of a transformer includes pillars located on the left, right, and center, and yokes located on the upper and lower sides respectively. The pillar section and the yoke section of the iron core are polygons composed of a rectangle and several trapezoids, and the rectangle is located in the middle of the polygon , The trapezoids of each level are located on both sides of the long side of the rectangle, and the bottom sides of the trapezoids on each side are connected to the long side of the rectangle in sequence; the characteristics are: two adjacent levels in the cross section of the column and the yoke The lengths of the adjacent bottom edges of the trapezoid are different, and the length of the bottom edge of the trapezoid closer to the rectangle is greater; and the area of the cross section of the yoke is larger than the area of the cross section of the column.
The laminated iron core of a transformer according to claim 1, wherein the pillar cross section and the yoke cross section of the iron core are inscribed polygons with a circle, an oval, or an ellipse.
The laminated iron core of a transformer according to claim 1, wherein the iron core has a three-phase three-pillar structure.
A method for preparing a laminated iron core of a transformer according to claim 1, which comprises the following steps:

1. Make the first-level core corresponding to the first-level trapezoid at the bottom of the polygon in the column cross-section and the yoke cross-section: cut the silicon steel sheet coil longitudinally at a desired angle to the length to obtain the first-level trapezoidal silicon steel strip; Starting from the small end of the first-level trapezoidal silicon steel strip, the horizontal cutting is performed in sequence along the length of the first-level trapezoidal silicon steel strip. The cutting sequence is the same number of left and right pillars, middle pillars and Bottom and upper yoke sheet to obtain multiple silicon steel sheets of first-level core; stack the multiple silicon steel sheets of first-level core from small to large in a single or multiple groups at a time, the stacking order is left, The right column piece, the middle column piece and the upper and lower yoke pieces make a first-level iron core;

2. Make the second-level iron core corresponding to the second-level trapezoid in the column section and the yoke section: cut the silicon steel sheet coil longitudinally at a desired angle to the length direction to obtain the second-level trapezoidal silicon steel strip. The width of the small end of the trapezoidal silicon steel sheet is the width of the large end of the first-stage trapezoidal silicon steel sheet after cutting the last upper yoke in step one; the small end of the second-stage trapezoidal silicon steel sheet is the starting end. Cut horizontally along the length direction of the second-level trapezoidal silicon steel strip, the cutting sequence is the same as the cutting sequence in the above step 1, to obtain multiple silicon steel sheets of the second-level core; the multiple silicon steel sheets of the second-level core are in the first level On the basis of the iron core, lamination is carried out in a single piece or multiple pieces at a time according to the size from small to large, and the lamination sequence is the same as the lamination sequence in the above step 1, to obtain a secondary core, the column section and the yoke of the secondary core The cross section is the second-level trapezoid above the first-level trapezoid and adjacent to the first-level trapezoid;

3. According to the rules of steps 1 and 2 above, make the cores corresponding to the trapezoids of the subsequent required number of stages on the rectangular side of the column section and the yoke section until the N-level core is obtained, the column section and the yoke of the N-level core The cross-section is the Nth-level trapezoid located above and adjacent to the N-1th-level trapezoid; where N is a natural number greater than or equal to 2;

4. Make the intermediate cores corresponding to the rectangles in the column section and the yoke section: rectangular silicon steel strips are longitudinally cut on the silicon steel sheet coil according to the size of the transformer core stack; the width of the rectangular silicon steel strips is N after cutting in step three The width of the large end of the N-level trapezoidal silicon steel strip after the first upper yoke in the grade core; starting from one end of the rectangular silicon steel strip, cut a number of the same amount laterally along the length of the rectangular silicon steel strip The left and right pillar pieces, the middle pillar piece, and the upper and lower yoke pieces, to obtain a plurality of silicon steel sheets of the middle-level core; a single piece of silicon steel sheets of the middle-level core on the basis of the N-level core prepared in step 3 above Lamination is carried out in groups of one or more, and the lamination sequence is the same as the lamination sequence in step 1 above, to produce an intermediate level core, that is, an N + 1 level core;

Fifth, the N + 2 level core corresponding to the N + 2 level trapezoid on the other side of the rectangle in the above column section and yoke section is made: the silicon steel sheet coil is longitudinally cut at a desired angle to the length direction to obtain The N + 2 level trapezoidal silicon steel strips of the same specification, the N + 2 level trapezoidal silicon steel strips with the same specifications, starting from the small end of the N + 2 level trapezoidal silicon steel strips, along the N + 2 level trapezoidal silicon steel strips Cut horizontally in order in the length direction, the cutting sequence is the same as the cutting step in the above step 1, to obtain multiple silicon steel sheets of N + 2 grade core; multi-piece silicon steel sheets of N + 2 grade core on the basis of N + 1 grade core The size is from large to small, one piece or multiple pieces are stacked at a time, and the lamination sequence is the same as the lamination sequence in the above step 1, to obtain an N + 2 grade core;

Sixth, make the N + 3 level core corresponding to the N + 3 level trapezoid located on the other side of the rectangle in the above column section and yoke section: cut the silicon steel sheet coil longitudinally at a desired angle to the length direction, and obtain N-1 level trapezoidal silicon steel strips The same specifications of N + 3 level trapezoidal silicon steel strips, starting from the small end of the N + 3 level trapezoidal silicon steel strips, along the N + 3 level trapezoidal silicon steel strips The longitudinal direction of the strip is cut horizontally in sequence, and the cutting sequence is the same as the cutting step in the above step 1, to obtain multiple silicon steel sheets of the N + 3 grade core; the multiple silicon steel sheets of the N + 3 grade core are based on the N + 2 grade core Lamination according to the size from large to small single piece or multiple pieces at a time, the lamination sequence is the same as the lamination sequence in the above step 1, to obtain an N + 3 grade core, the column cross section of the N + 3 grade core and The yoke cross section is the N + 3 stage trapezoid above the N + 2 stage trapezoid and adjacent to the N + 2 stage trapezoid;

7. According to the rules of steps 5 and 6 above, make the cores corresponding to the trapezoids of the subsequent required stages in the column section and the yoke section on the other side of the rectangle until a 2N + 1 level core is obtained, that is, a complete transformer is made Stacked core, the column section and yoke section of the 2N + 1-level core are the 2N + 1-level trapezoids located above and adjacent to the 2N-level trapezoid;

The above-mentioned horizontal cutting adopts the cutting method of the positive and negative knives at a desired angle with the longitudinal direction.
The preparation method according to claim 4, characterized in that the trapezoidal silicon steel sheet strips of the same specification can be cut by stacking the silicon steel sheet coils up and down.
The preparation method according to claim 4, characterized in that the silicon steel sheets are laminated on an iron core stacking table, each of the silicon steel sheets is provided with at least one positioning hole, and the iron core stacking table is protruded There is a positioning rod that can pass through the positioning hole and position and stack the silicon steel sheet.
The preparation method according to claim 4, characterized in that: the order of cutting the left and right pillars is to cut at least three left pillars first, and then cut the right pillars equal to the number of left pillars; or first cut one left Columns, then cut a right column, and then a left column, and so on, at least three left columns and right columns with the same number as the left column are cut; then at least three middle columns are cut.
The preparation method according to claim 7, characterized in that the order of cutting the lower and upper yokes is to first cut several lower yokes with the same number as the left column, and then cut several upper yokes with the same number as the lower yoke Yoke piece; or first cut a lower yoke piece, then cut an upper yoke piece, and then cut a lower yoke piece, in this way, cut the lower yoke piece with the same number as the left column piece and the upper yoke with the same number as the lower yoke piece sheet.
The method for preparing a laminated iron core of a transformer according to claim 4, characterized in that the cutting of the trapezoidal silicon steel sheet strip is achieved by a cutting device including a conveying track for carrying the trapezoidal silicon steel sheet strip, respectively located in the conveyor Two feed limiters on both sides of the track that limit the conveyed trapezoidal silicon steel strips are also equipped with an adjustment mechanism that can adjust the distance between the two feed limiters, so that The distance between the two sheet-feeding stoppers can be continuously adjusted according to the width of the trapezoidal silicon steel sheet bar, so that the trapezoidal silicon steel sheet bar is located along the center line of the conveying track.
The method for preparing a laminated iron core of a transformer according to claim 9, characterized in that the adjustment mechanism includes a screw rod with opposite thread directions at both ends and a motor driving the screw rod to rotate, and the two feed-in limits The pieces are respectively screwed at the two ends of the screw rod, and are provided with a guide structure that only allows the two film advancement limiting pieces to move in the axial direction of the screw rod as the screw rod rotates.