Primary winding wire winding size control and positioning die and wire winding method for mutual inductor

Abstract

The present invention provides a die and a winding method for controlling the winding size and positioning of the primary winding of an instrument transformer, including a base, a first limiting block, a second limiting block, and a primary wiring board positioning plate. The base is a rectangular groove body. Through-wire windows are processed on the first group of side walls, and a first alignment groove and a second alignment groove are processed on the second group of side walls. The first limiting block is located above the base, and a first alignment convex block is processed on the end face of the first limiting block and is connected in alignment with the first alignment groove of the base. The second limiting block is located above the first limiting block, and a second alignment convex block is processed on the end face of the second limiting block and is connected in alignment with the second alignment groove of the base. The primary wiring board positioning plate is fixedly connected to the top of the second limiting block. The structure of the present invention is compact and ingeniously conceived. All the secondary windings of the instrument transformer that can be installed in the combined box are completely encapsulated inside. There is a fixed position for the primary wiring board on the die, realizing the synthesis and production of the primary winding and the secondary winding of the instrument transformer in one go.

Description

Technical Field

[0001] The invention belongs to the technical field of mutual inductor processing, and particularly relates to a primary winding winding size control and positioning die and a winding method for a mutual inductor. Background Art

[0002] A mutual inductor is an instrument that measures by converting the current or voltage on the primary side into the current or voltage on the secondary side according to the principle of electromagnetic induction. The winding connected to the measured current or voltage in the mutual inductor is called the primary winding; the winding connected to the measuring instrument is called the secondary winding. For a primary mutual inductor, especially a current mutual inductor, a primary winding needs to be wound together on one or more secondary windings. As Figure 1 shown, there must be a certain insulation distance between the primary winding, the secondary winding, and the body of the mutual inductor. Contacting each other or the distance not meeting the design requirements will affect the service life of the mutual inductor or even cause the mutual inductor to be broken down and scrapped. Therefore, the winding position of the primary winding and the volume of the primary winding after winding are great influencing factors for the overall qualification rate of the mutual inductor.

[0003] There are two basic schemes for current primary winding winding: One is to use a multi-strand square or round soft wire with a relatively thin insulating layer without an external shield and a hard metal shell, wind it on a square die with corresponding dimensions, and then shape it into a primary winding. The other is to use a soft copper strip with slightly increased hardness, wind one turn or multiple turns on a square die with corresponding dimensions. When winding multiple turns, a cardboard with a certain thickness is filled between the turns for insulation isolation. This scheme is that first, without the secondary winding, only the primary winding is wound into shape. Then, the primary winding is disassembled, the secondary winding is sleeved in, and then manually reset, and the primary winding is restored to the state after being wound into shape. Since the primary winding is a copper strip wound in circles, when disassembling, the slight misalignment of the inner circle of the deformation will gradually amplify with the number of turns, resulting in it being often difficult to restore to the original tightly wound state, and it is difficult to achieve a tight and firm arrangement between the turns. Moreover, the slow manual reset speed and great process difficulty lead to low production efficiency. After the primary winding is buffered and wrapped with external insulation, the structure of the finished primary winding is relatively loose, and the outline dimensions become larger, reducing the effective insulation distance between the primary winding of the mutual inductor and the secondary winding or the outside, directly affecting its insulation withstand voltage ability and performance. At the same time, because the structure of the primary winding is loose, its mechanical support strength is weakened during the production and manufacturing of the primary winding. Subsequently, when pouring insulating materials such as epoxy resin or oil into the mold during subsequent installation, it cannot be ensured that the primary winding is fixed in the designed position, and there will be large deformation or displacement, resulting in the uncertain position dimensions of the primary winding, the secondary winding, and other components, and the insulation distance between them cannot be guaranteed, causing adverse phenomena such as electrical breakdown or reduced insulation performance, increasing the scrap rate of the product and greatly reducing the qualification rate. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a primary winding winding size control and positioning mold and winding method for a mutual inductor, adopting a method of directly winding the primary winding on the secondary winding for one-time forming, thereby solving the problems of loose winding structure, difficulty in resetting, difficulty in ensuring product insulation distance, weak mechanical support strength of the primary winding and high scrap rate after the primary winding is wound on the secondary winding.

[0005] The technical solution adopted by the present invention is: a primary winding winding size control and positioning mold of a mutual inductor, comprising a base, a first limit block, a second limit block and a primary wiring board positioning plate, the base is a rectangular trough body with rounded corners, having two groups of corresponding side walls, namely a first group of side walls and a second group of side walls, wherein the first group of side walls are respectively processed with a threading window for passing the wire, and the second group of side walls are respectively processed with a first alignment groove and a second alignment groove, the first limit block is located at the upper part of the base, and the end face of the first limit block is processed with a first alignment protrusion that is aligned with the first alignment groove of the base, the second limit block is located at the upper part of the first limit block, and the end face of the second limit block is processed with a second alignment protrusion that is aligned with the second alignment groove of the base, the primary wiring board positioning plate is connected to the upper part of the second limit block, and the upper end face of the second group of side walls is higher than the upper end face of the first group of side walls, which is used for lateral limiting of the first limit block.

[0006] Preferably, the base, the first limit block and the second limit block are combined to form a box structure, and all the secondary windings required by the transformer design are installed in the box. The width dimension between the outer side walls of the combined first limit block and the second limit block is equal to the outer side width of the rectangular slot of the base, which is equal to the length dimension L1 of the window in the primary winding of the transformer. The inner side width of the rectangular slot is greater than or equal to the overall thickness L2 of the secondary winding. The thickness dimension of the combined first limit block and the second limit block is equal to the height dimension A of the window in the primary winding of the transformer. The length of the rectangular slot and the total depth of the combined box are both greater than The outer diameter of the secondary winding, the width between the outer side walls is along the direction of the first set of side walls, the thickness is in the height direction of the mold, the length of the rectangular slot is along the direction of the second set of side walls, the upper end of the threading port is an open structure, the width of the threading port is greater than the wire arrangement width required by the primary winding design, the height of the threading port is greater than the total winding thickness of the primary winding, and is greater than the total thickness of the primary winding plus the thickness of the shaping strip, so that during the processing, the shaping strip is extended under the wire wound in the height direction of the threading window to flatten the wound wire. The box structure prevents a series of adverse phenomena such as hitting, vibration, bumping, scratching, etc. caused by external behaviors during the winding of the primary winding.

[0007] Preferably, the first limiting block includes a first alignment plate and side plates. There are two side plates, which are respectively fixedly connected to both sides of the first alignment plate. The side plates and the first group of side walls of the base are in the same plane. The side plates are right trapezoidal plates, and the right-angle sides of the side plates are butted against the upper end faces of the side walls of the base. The right-angle sides of the side plates at the outer corners of the upper edge of the wire threading window are chamfered with a radius of R. The slope of the hypotenuse is matched with the slope of the lower end face of the second limiting block. The lowermost part of the first alignment plate is a first alignment bump, and the shape of the first alignment bump is adapted to the shape of the first alignment groove. The uppermost part of the first alignment plate is higher than the upper part of the side plates and is used for lateral limiting of the second limiting block. A first threaded hole is machined at the center of the upper end face of the first alignment plate. R is the designed dimension value of the inner corner radius of the inner window of the primary winding of the transformer. The designed dimension values of the inner corner radii of the four inner windows of the primary winding of the transformer are all R.

[0008] Preferably, the second limiting block includes a second alignment plate and a top plate. The top plate includes two side faces and a top face. The lower end faces of the two side faces are hypotenuses that are matched with the upper end faces of the side plates. The top face is a horizontal plane, and the outer side at the junction of the top face and the side faces is chamfered with a radius of R. A second alignment plate is fixedly connected to one end of the top plate. The lowermost part of the second alignment plate is a second alignment bump, and the shape of the second alignment bump is adapted to the shape of the second alignment groove. A positioning through hole slightly larger than the first threaded hole is machined at the center of the other end of the top plate. The positioning through hole and the first threaded hole are vertically aligned, and a positioning pin passes through the positioning through hole and is threadedly connected to the first threaded hole. The second alignment plate is limited in the length direction of the base groove body and is limited in the opposite direction to the first alignment plate.

[0009] Preferably, the primary wiring board positioning plate includes a base and a primary wiring board positioning seat. The base is connected or welded to the upper part of the top plate by screws. A primary wiring board positioning seat is fixedly connected to the upper part of the base. Through holes are machined on the wiring board positioning seat. The dimensions, angles, and positions of the wiring board positioning seat respectively correspond to the designed dimensions, angles, and positions of the primary winding wiring board of the transformer. The primary wiring positioning plate can have positioning methods that satisfy the primary wiring board of the transformer being flat, upright, or at any other angle. Through holes corresponding to the designed dimensions and quantities of the threaded holes for connecting the primary wiring terminals of the transformer are machined on the wiring board positioning seat. If the connection hole for connecting to the external electrical connection on the primary wiring terminal of the primary winding of the transformer is a threaded hole, the diameter of the through hole on the wiring board positioning seat is slightly larger than the diameter of the threaded hole of the primary wiring terminal of the transformer. If the connection hole for connecting to the external electrical connection on the primary wiring terminal of the transformer is a through hole, the diameter of the through hole on the wiring board positioning seat is slightly larger than or equal to the diameter of the through hole of the primary wiring terminal of the transformer. By using bolts with corresponding dimensions, the primary wiring terminals of the transformer are tightly connected to the wiring board positioning seat on the mold, which can fixedly connect and position one end of the primary winding to the mold, facilitating wire winding and ensuring that the structure of the wound primary winding is flat and firm, and the positions of all relevant components meet the designed dimension and position requirements.

[0010] Preferably, the dimension between the top surface of the second limiting block and the primary wiring board positioning seat is greater than F, where F is the total thickness of the primary winding at the top plus the distance of the primary wiring terminal carried by the primary winding. The primary wiring terminal is generally of an L-shaped, U-shaped or semi-U-shaped structure. When the primary winding is a multi-turn structure, it is convenient to reliably connect the first layer or the first turn upward through this connection to the primary wiring board for connecting to an external conductor without affecting the normal winding positions of the second turn and subsequent multi-turns according to the design requirements, and to ensure that the electrical conductivity requirements are met, so as to facilitate easy loading and unloading during the winding of the primary winding. However, if there are special requirements, the dimension can be even larger.

[0011] Preferably, the short upper base of the right-angled trapezoid on the side plate of the first limiting block and the long lower base of the right-angled trapezoid on the second alignment plate of the second limiting block are on the same side as the base of the primary wiring board positioning plate.

[0012] The present invention also relates to a method for winding the primary winding of an instrument transformer, comprising the following steps:

[0013] Step 1: Fix the base on the work station, and align and install the secondary winding into the slot of the base, with the center of the secondary winding aligned with the center of the wire passing opening;

[0014] Step 2: Align and connect the first limiting block with the base;

[0015] Step 3: Align and connect the second limiting block with the base;

[0016] Step 4: Position and lock the first limiting block and the second limiting block through a positioning pin;

[0017] Step 5: Fix and connect the primary wiring terminal of the primary winding with the primary wiring board positioning seat through a bolt assembly;

[0018] Step 6: Pass the wire of the primary winding through the wire passing window, and wind and tighten it turn by turn according to the number of turns required by the design for shaping;

[0019] Step 7: After the winding is completed, loosen the fixing bolts connecting the primary wiring terminal of the primary winding and the primary wiring board positioning seat to release the connection, then remove the positioning pin, pull out the second limiting block along the lower inclined surface direction, and then pull out the first limiting block;

[0020] Step 8: Take out the primary winding and the secondary winding as a whole from the base.

[0021] Preferably, during the process of step 6, through a long strip-shaped shaping strip plate, the shaping strip plate is inserted into the lower part of the primary winding in the side wall wire threading window, and by the method of pressing up and down with a lever effect, the tightness of the arrangement of the conductors in the lower part of the primary winding of the mutual inductor in the base cavity and the generated arc are flattened and standardized to meet the design size and relative position requirements.

[0022] The beneficial effects of the present invention are as follows: 1. The structure of the present invention is compact. When winding the primary winding, all secondary windings are directly wound and formed at one time. The shape is regular, the structure is compact, the outer contour size is the smallest, meeting the design size requirements. At the same time, because the primary winding is wound tightly, the turns of the primary winding are wound and arranged tightly and firmly. After being buffer-wrapped with external insulation, the overall mechanical support strength is large. When pouring insulating materials such as epoxy resin or oil into the mold in the subsequent process, the primary winding can be well fixed in the designed position without deformation or displacement, ensuring that the relative position dimensions of the primary winding, secondary winding and other components meet the design requirements, making the outer contour size of the mutual inductor relatively the smallest, and enabling the insulation distances in all directions between the primary winding, secondary winding and the outer insulation layer of the body to reach the relatively maximum state, ensuring that the product has high insulation performance and production processability.

[0023] 2. There is a fixed position for the primary wiring terminal of the mutual inductor on the mold. Based on this positioning, the positioning of another primary wiring terminal can be determined at the same time, so that the relative positions of all primary wiring terminals can be determined at one time. The winding operation of the primary winding is simple and the positioning is accurate, improving production efficiency.

[0024] 3. The mold can also ensure that when winding the primary winding, the secondary winding is installed in the mold groove body and will not be damaged by direct or indirect strikes or impacts from external forces or external substances.

[0025] 4. The qualified rate of the mutual inductor produced by using the mold and method of the present invention is extremely high, and the excellent rate of the relevant technical indicators of the product has a qualitative improvement, generally reaching the excellent performance value range. The insulation margin and space margin of the product are both increased. After testing, under the condition of the same outer dimension, the dynamic and thermal stability current value of the product can be improved, and the rated output value of the product can be increased, that is, the electrical performance of the mutual inductor is increased.

[0026] 5. The mold design concept is ingenious, the structure is simple, the weight is light, the cost is very low, it has a combined and detachable structure, the operation is convenient and fast, and the production efficiency is very high. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the body structure of a mutual inductor with a horizontal plate structure for the primary wiring terminal;

[0028] Figure 2Schematic diagram of the body structure of an instrument transformer with a vertical primary terminal

[0029] Figure 3 Schematic cross-sectional structure diagram of a die for controlling and positioning the winding size of the primary winding of an instrument transformer

[0030] Figure 4 Schematic three-dimensional diagram of a die applicable to a horizontal plate structure of the primary terminal

[0031] Figure 5 Schematic three-dimensional diagram of a die applicable to a vertical structure of the primary terminal Figure 1 ;

[0032] Figure 6 Schematic three-dimensional diagram of a die applicable to a vertical structure of the primary terminal Figure 2 ;

[0033] Figure 7 Schematic diagram of the structure of the base

[0034] Figure 8 Schematic diagram of the structure of the first limit block

[0035] Figure 9 Schematic diagram of the structure of the second limit block

[0036] Figure 10 Schematic diagram of the structure with a vertical structure of the primary external wiring board fixing block

[0037] Figure 11 Schematic diagram of the structure with a planar structure of the primary external wiring board fixing block

[0038] Figure 12 Schematic diagram of the structure with other angular structures of the primary external wiring board fixing block

[0039] Figure 13 Schematic diagram of the shaping plate structure

[0040] Reference numerals: 1 - base, 2 - first limit block, 3 - second limit block, 4 - primary wiring board positioning plate, 5 - primary winding, 6 - secondary winding, 7 - primary terminal, 8 - positioning pin, 101 - wire passing window, 102 - first alignment groove, 103 - second alignment groove, 201 - first alignment plate, 202 - side plate, 203 - first alignment protrusion, 204 - first threaded hole, 301 - second alignment plate, 302 - top plate, 303 - second alignment protrusion, 304 - positioning through hole, 305 - side wall plate, 401 - base, 402 - primary wiring board positioning seat, 403 - through hole Detailed implementation manners

[0041] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] As Figure 1 and Figure 2 shown, the primary winding 5 of this embodiment is a copper wire (such as a copper strip), which has more excellent performance compared with other types of flexible wires, is structurally compact, has a larger effective conductive area per unit cross-section, higher conductive efficiency, and has the smallest outer contour size and occupies less space when having the same conductive cross-section and the same number of conductive turns wound. When ensuring the same insulation distance from the secondary winding, it makes the overall size of the secondary winding, including the outer contour size, smaller, and thus also makes the outer contour size of the entire current transformer smaller. However, it has a relatively large hardness and a certain resilience, so the mold described in the present invention is required to ensure that the structure between multiple turns of copper strips is compact, the structure after winding is flat and regular, and the outer contour size and occupied space are the smallest, all meeting the design size and scheme requirements, and at the same time having strong mechanical strength and support force.

[0043] As Figures 3 to 6 shown, a mold for controlling the winding size and positioning of the primary winding of a current transformer includes a base 1, a first limiting block 2, a second limiting block 3, and a primary wiring board positioning plate 4. The first limiting block 2 is located on the upper part of the base 1. The base 1 is a rectangular groove body with rounded corners, having two groups of corresponding side walls, namely the first group of side walls and the second group of side walls. Among them, a wire passing window 101 for passing a wire is respectively processed on the first group of side walls, and a first alignment groove 102 and a second alignment groove 103 are respectively processed on the second group of side walls. The upper end surface of the second group of side walls is higher than the upper end surface of the first group of side walls for the lateral limiting of the first limiting block. The first limiting block 2 is located on the upper part of the base 1. A first alignment convex block 203 is processed on the end surface of the first limiting block 2 and is connected in alignment with the first alignment groove 102 of the base 1. The second limiting block 3 is located on the upper part of the first limiting block 2. A second alignment convex block 303 is processed on the end surface of the second limiting block 3 and is connected in alignment with the second alignment groove 103 of the base 1. The primary wiring board positioning plate 4 is connected to the upper part of the second limiting block 3.

[0044] As Figure 6 and Figure 7As shown, the base 1 is a rectangular slot, one set of side walls is processed with a threading window 101, and the other set of side walls is processed with a first alignment groove 102 and a second alignment groove 103. The width of the slot of the base 1 is the distance between the two side walls with the threading opening 101, and the length of the slot is the distance between the two side walls with the first alignment groove 102 and the second alignment groove 103. The width of the slot is slightly larger than the total thickness of all the secondary windings 6. The secondary windings 6 can be one or more in parallel. The base 1, the first The length and height of the inner cavity of the box formed by the limit block 2 and the second limit block 3 should be appropriately larger than the outer diameter of the secondary winding, and the width should be slightly larger than the total thickness L2 of all the secondary windings 6; the upper end of the threading window 101 is an open structure, which is convenient for the primary winding 5 and the secondary winding 6 to be taken out as a whole after winding. The width of the threading window 101 is larger than the width of the primary winding 5, and the depth of the threading opening 101 is larger than the total thickness of the thickness of the primary winding 5 after winding plus the thickness of the shaping strip. Figure 13 As shown, the shaping strip is a long steel strip of suitable size. When the primary winding is wound, the shaping strip is inserted into the lower part of the primary winding 5 in the threading window 101, and the conductor of the lower part of the primary winding 5 of the transformer is further shaped by the up and down pressing method of the lever, so as to enhance the tightness of the arrangement and flatten the generated curvature. It plays a role in limiting the flatness of the thickness direction of the secondary winding 6, so that after the primary winding 5 is wound, the shape of the lower part of the primary winding 5 in the inner cavity of the base 1 is flattened and standardized to meet the design size and relative position requirements.

[0045] like Figure 8 As shown, the first limit block 2 includes a first alignment plate 201 and a side plate 202. There are two side plates 202, which are fixedly connected to the two sides of the first alignment plate 201 respectively. The upper end surface of the first alignment plate 201 is slightly higher than the upper edge of the side plate 202, which serves as a lateral or left and right limit baffle of the second limit plate 3. The lower end surface of the first alignment plate 201 is lower than the lower edge of the side plate 202. The side plate 202 is a right-angled trapezoid, and the right-angled side is connected to the upper end surface of the side wall of the base 1 with the threading window 101, and the outer side of the lower edge of the two side plates 202 of the first limit block 2 at the threading window 101 is chamfered R, and the width of the chamfer R is at least greater than or equal to the width of the threading window 101, which can be as shown in FIG. Figure 7The lower edges of the two side plates 202 directly above the wire threading window 101 are chamfered with an R chamfer on the outer side, or the lower edges of the entire side plate 202 can be chamfered with an R chamfer on the outer side. The slope of the hypotenuse matches the slope of the lower ends of the two side wall plates 305 of the top plate 302 of the second limiting block 3. The lowermost part of the first alignment plate 201 is the first alignment convex block 203, and the shape of the first alignment convex block 203 is adapted to the shape of the first alignment groove 102. After assembly, the first limiting block 2 can only be withdrawn along the back of the first alignment convex block 203, that is, the short side of the upper bottom of the first limiting block and the long side of the lower bottom of the second limiting block are both in the direction on the side where the second limiting block and the fixed position of the primary wiring positioning block above it are located. Limited in other directions, a first threaded hole 204 is machined at the center of the upper end surface of the first alignment plate 201.

[0046] As Figure 9 shown, the second limiting block 3 includes a second alignment plate 301 and a top plate 302. The top plate 302 includes two side wall plates 306 and a top surface. The lower end surfaces of the two side wall plates 305 are hypotenuses that cooperate with the upper end surfaces of the side plates 202, and the top surface is a horizontal plane. The chamfer at the joint of the top surface and the side surface is R. As Figure 1 shown, R is the chamfer radius required for the inner circle design of the primary winding 5. The second alignment plate 301 is fixedly connected to the lower part of one end of the top plate 302. The lowermost part of the second alignment plate 301 is the second alignment convex block 303, and the shape of the second alignment convex block 303 is adapted to the shape of the second alignment groove 104. After assembly, the second limiting block 3 can only be withdrawn along the back of the second alignment convex block 303. Limited in other directions, a second through hole 304 is machined at the center of the other end of the top plate 302. The second through hole 304 is vertically aligned with the first threaded hole 204. After the first limiting block 2 and the second limiting block 3 are positioned and locked by passing a positioning pin 8 through the second through hole 304 and threadedly connecting it to the first threaded hole 204, the first limiting block 2 and the second limiting block 3 are integrally limited and locked with the base 1, and a hollow box body is formed. As Figure 1 shown, the distance from the lower end surface of the side wall plate 202 to the upper end surface of the top plate 302 is equal to A. The width dimension between the outer side walls after the combination of the first limiting block and the second limiting block is equal to the length dimension L1 of the inner window of the primary winding of the current transformer. A is the distance between the side of the primary winding 5 located inside the secondary winding 6 and the opposite side located outside the secondary winding 6 required by the design. L1 is the dimensional requirement for the length of the inner window of the primary winding required by the design. Plus the R chamfer on the outer side of the lower edges of the two side wall plates at the wire threading window of the first limiting and the R chamfer at the joint of the top surface and the side surface, ensuring that the shape of the primary winding 5 wound with a mold meets the design requirements.

[0047] As Figures 10 to 12As shown in the figure, the primary wiring board positioning plate 4 includes a base 401 and a wiring board positioning seat 402. The base 401 is connected to the upper part of the top plate 302 by screws, welding or bonding. The upper part of the base 401 is fixedly connected to the wiring board positioning seat 402. Through holes 403 that match the number and position of the holes on the primary wiring terminals 7 are machined on the wiring board positioning seat 402. The angle and position of the wiring board positioning seat 402 correspond to the angle and position of the primary wiring terminals 7 of the primary winding 5. The wiring board positioning seat 402 can be of a vertical structure, a horizontal plate structure or a structure with a certain inclination angle. The primary wiring terminals 7 of the primary winding 5 can be connected to the wiring board positioning seat 402 of the mold through bolt and nut assemblies, which is convenient for fastening and positioning when winding the primary winding wires. For example, as Figure 10 shown, when the direction of the wiring board positioning seat 402 is perpendicular to the top plate 302, it is applicable to the case where the end face of the primary wiring terminal 7 is perpendicular to the top plate 302. As Figure 11 shown, when the direction of the wiring board positioning seat 402 is parallel to the top plate 302, it is applicable to the case where the end face of the primary wiring terminal 7 is parallel to the top plate 302. As Figure 12 shown, when the direction of the wiring board positioning seat 402 is neither perpendicular nor parallel to the top plate 302, the included angle between the plane of the wiring board positioning seat 402 and the plane of the top plate 302 is equal to the included angle between the end face of the primary wiring terminal 7 and the top plate 302.

[0048] As Figure 6 shown, the present invention also relates to a method for winding the primary winding of an instrument transformer, including the following steps:

[0049] Step 1: Fix the base 1 on the workbench, align and install the secondary winding 6 into the slot of the base 1, and align the center of the secondary winding 6 with the center of the wire threading window 101;

[0050] Step 2: Align and connect the first limit block 2 with the base 1;

[0051] Step 3: Align and connect the second limit block 3 with the base 1;

[0052] Step 4: Lock the first limit block 2 and the second limit block 3 on the base 1 through the positioning pin 8;

[0053] Step 5: Fix and connect the primary wiring terminals 7 of the primary winding 5 with the through holes 403 of the primary wiring board positioning plate 4 through bolt assemblies;

[0054] Step 6: Pass the copper strip of the primary winding 5 through the wire threading window 101 and wind it turn by turn and tighten it into a shape. The shaping strip can be inserted into the wire threading window 101 and into the lower part of the primary winding 5 inside the base 1. By pressing up and down by means of a lever, the conductor in the lower part of the primary winding 5 of the instrument transformer can be further shaped to enhance the tightness of the arrangement and flatten the generated arc;

[0055] Step 7: After the winding is completed, loosen and remove the bolt assembly on the wiring board positioning seat 402, disconnect the primary wiring terminal 7 of the primary winding 5 from the wiring board positioning seat 402, remove the positioning pin 8, draw out the second limiting block 3 along the downward inclined plane direction, and then draw out the first limiting block 2;

[0056] Step 8: Take out the overall body of the combined primary winding 5 and secondary winding 6 from the base 1.

[0057] The above are the specific embodiments of the present invention and the technical principles applied. Any modification or equivalent transformation based on the technical solution of the present invention shall be included within the protection scope of the present invention.

Claims

1. A die for controlling the winding size and positioning of the primary winding of a mutual inductor, characterized in that: It includes a base, a first limiting block, a second limiting block and a primary wiring board positioning plate. The base is a rectangular groove body with rounded corners, having two sets of corresponding side walls, namely the first set of side walls and the second set of side walls. Among them, a wire-passing window for passing through wires is respectively processed on the first set of side walls, and a first alignment groove and a second alignment groove are respectively processed on the second set of side walls. The first limiting block is located on the upper part of the base, and a first alignment convex block is processed on the end face of the first limiting block to be connected in alignment with the first alignment groove of the base. The second limiting block is located on the upper part of the first limiting block, and a second alignment convex block is processed on the end face of the second limiting block to be connected in alignment with the second alignment groove of the base. The primary wiring board positioning plate is connected to the upper part of the second limiting block. The upper end face of the second set of side walls is higher than the upper end face of the first set of side walls for lateral limiting of the first limiting block. The combination of the base, the first limiting block and the second limiting block forms a box structure. All secondary windings required by the design of the current transformer are installed in the box. The width dimension between the outer side walls of the combined first limiting block and the second limiting block is equal to the outer width of the rectangular groove body of the base, which is equal to the length dimension L1 of the inner window of the primary winding of the current transformer. The inner width of the rectangular groove body is greater than or equal to the total thickness L2 of the secondary windings. The thickness dimension of the combined first limiting block and the second limiting block is equal to the height dimension A of the inner window of the primary winding of the current transformer. The length of the rectangular groove body and the total depth of the combined box are greater than the outer diameter of the secondary windings. The width between the outer side walls is along the direction of the first set of side walls, the thickness is in the height direction of the mold, and the length of the rectangular groove body is along the direction of the second set of side walls. The upper end of the wire-passing opening is an open structure. The width of the wire-passing opening is greater than the wire arrangement width required by the design of the primary winding, and the height of the wire-passing opening is greater than the total winding thickness of the primary winding; The first limiting block includes a first alignment plate and side plates. There are two side plates, which are respectively fixedly connected to both sides of the first alignment plate. The side plates and the first set of side walls of the base are in the same plane. The side plates are right trapezoidal plates. The right-angle sides of the side plates are butted against the upper end faces of the base side walls. The right-angle sides of the side plates at the outer corners of the upper edge of the wire-passing window are chamfered with a radius of R. The hypotenuse is matched with the slope of the lower end face of the second limiting block. The lowermost part of the first alignment plate is a first alignment convex block, and the first alignment convex block is adapted to the shape of the first alignment groove. The uppermost part of the first alignment plate is higher than the upper part of the side plates for lateral limiting of the second limiting block. A first threaded hole is processed at the center of the upper end face of the first alignment plate. R is the designed dimension value of the inner corner radius of the inner window of the primary winding of the current transformer. The second limiting block includes a second alignment plate and a top plate. The top plate includes two side faces and a top face. The lower end faces of the two side faces are bevel edges that cooperate with the upper end faces of the side plates. The top face is a horizontal plane, and the outer chamfer at the junction of the top face and the side face is R. A second alignment plate is fixedly connected to one end of the top plate. The lowermost part of the second alignment plate is a second alignment convex block, and the shape of the second alignment convex block is adapted to that of the second alignment groove. A positioning through hole slightly larger than the first threaded hole is machined at the center of the other end of the top plate. The positioning through hole is vertically aligned with the first threaded hole, and a positioning pin passes through the positioning through hole and is threadedly connected to the first threaded hole.

2. The die for controlling the winding size and positioning of the primary winding of a mutual inductor according to claim 1, characterized in that: The primary wiring board positioning plate includes a base and a primary wiring board positioning seat. The base is fixedly connected to the upper part of the top plate by screw connection, welding or bonding. A primary wiring board positioning seat is fixedly connected to the upper part of the base. A through hole is machined on the wiring board positioning seat. The size, angle and position of the primary wiring board positioning seat respectively correspond to the designed size, angle and position of the primary winding wiring board of the transformer. Through holes corresponding to the designed size and quantity of the butt-joint threaded holes of the primary wiring terminals of the transformer are machined on the primary wiring board positioning seat.

3. The die for controlling the winding size and positioning of the primary winding of a mutual inductor according to claim 1, characterized in that: The dimension between the top face of the second limiting block and the primary wiring board positioning seat is greater than F, where F is the total thickness of the primary winding at the top plus the distance of the primary wiring terminals carried by the primary winding.

4. The die for controlling the winding size and positioning of the primary winding of a mutual inductor according to claim 2, characterized in that: The short upper base of the right-angled trapezoid of the side plate of the first limiting block and the long lower base of the right-angled trapezoid of the second alignment plate of the second limiting block are on the same side as the base of the primary wiring board positioning plate.

5. A method for winding the primary winding of a mutual inductor using the die for controlling the winding size and positioning of the primary winding of a mutual inductor according to claim 1, characterized in that, It includes the following steps: Step 1: Fix the base on the workbench, align and install the secondary winding into the groove body of the base, and align the center of the secondary winding with the center of the wire passing opening. Step 2: Align and connect the first limiting block with the base. Step 3: Align and connect the second limiting block with the base. Step 4: Position and lock the first limiting block and the second limiting block through a positioning pin. Step 5: Fix and connect the primary wiring terminals of the primary winding and the primary wiring board positioning seat through a bolt assembly. Step 6: Pass the wire of the primary winding through the wire passing window, and wind and tighten it turn by turn according to the designed number of turns to form a shape. Step 7: After winding, loosen the fixing bolts of the primary wiring terminals of the primary winding and the primary wiring board positioning seat to release the connection, then remove the positioning pin, pull out the second limiting block along the lower inclined plane direction, and then pull out the first limiting block. Step 8: Take out the primary winding and the secondary winding as a whole from the base.

6. A method for winding the primary winding of a mutual inductor using the die for controlling the winding size and positioning of the primary winding of a mutual inductor according to claim 5, characterized in that: During the process of Step 6, through a long strip-shaped shaping strip plate, insert the shaping strip plate into the lower part of the primary winding in the side wall wire passing window, and by the method of pressing up and down with a lever action, level and standardize the tightness of the arrangement and the arc generated by the lower part of the conductor of the primary winding of the transformer in the base cavity to meet the requirements of the designed size and relative position.

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