JPH10172837A - Dry transformer - Google Patents

Abstract

(57) [Summary] [Problem] To provide a dry-type transformer with an improved winding structure in which metal fittings are simplified. SOLUTION: A cylindrical body 10 is formed by also using a winding form of a coil 1 as a contact plate, an iron core 3 is provided in the cylindrical body 10, a mold removing operation after resin curing is omitted, and a mold cleaning operation. In addition to reducing the number of man-hours for managing the mold, a joint is provided to project from the tubular body 10 abutting on each coil 1 to the upper clamp 8 and the lower clamp 9, and this joint and the two clamps are bolted together. 20 and cooperate to share the load during the transportation and installation of the transformer. Thereby, the lower clamp 9
This eliminates the need for reinforcement by means of stays, resulting in a weld-less structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry transformer, and more particularly to an improvement in an internal structure of a dry transformer used as one of power supply facilities.

[0002]

2. Description of the Related Art The structure of a conventional transformer will be described with reference to FIG. FIG. 13 is a schematic internal structural view of a three-phase transformer according to the prior art. The three-phase transformer shown in FIG. 13 includes a plurality of coils 1 that generate an alternating magnetic field consisting of primary and secondary.
And a winding core 3 having legs disposed in the coil 1, a plate 2 inserted into a predetermined gap between the coil 1 and the winding core 3, and the coil 1 and the winding core 3 And an upper clamp 4 and a lower clamp 5 which are tightened from below.

The wound iron core 3 is formed by laminating a plurality of directional silicon steel sheets into a ring shape, and is formed so as to extend vertically, and is provided with three legs. The coil 1 is wound around each leg. The upper fastener 4 and the lower fastener 5 cooperate to fasten and clamp the wound core 3 from above and below. The contact plate 2 is formed of a general ordinary steel plate and formed in a straight horizontal plane, and is disposed between the legs on both outer sides of the wound core 3 and the coil 1 wound around the legs. .

Further, each of the abutment plates 2 is connected to a lower clamp 5 and a bolt / nut (not shown) via a stay 6 at a lower end thereof, and an upper clamp 4 is connected to an upper end thereof.
Are connected by bolts and nuts (not shown). The side surface of the fixing seat 7 for fixing the stay 6 and the transformer body T is firmly fixed to the lower fastener 5 by welding. With such a configuration, in cooperation with the plate 2 and the upper fastener 4, a robust structure capable of withstanding an excessive load during transportation of the transformer or in an installed state is configured.
In addition, as an example of the conventional transformer as described above,
Hitachi, Ltd. Catalog ST-126P and Toshiba Corporation
Transformers are listed in catalog CSSD-2901 and the like.

[0005]

In the conventional method of manufacturing a mold-type dry transformer, the coil and the metal fitting are manufactured through separate processes, and the two are combined at the time of the final assembly process. As shown in FIG. 13, the metal fitting has two contact plates 2 and, in order to support the weight of the transformer body T, welds a joint between the lower clamp 5 and the contact plate 2 via a stay 6. There was a problem that reinforcement had to be achieved, processing was troublesome, and metal fitting manufacturing cost was high.

Further, the coil manufacturing method requires a coil winding form in order to maintain the shape of the coil. In particular, in the case of a coil manufacturing method in which a liquid resin is poured and cured, the winding form is made of resin. In many cases, it also serves as a casting mold, so that the resin does not leak from the gap between the molds during casting.
Since the extra resin adheres to the mold at the time of casting or casting with a sealing material, after removing the mold, clean the mold, and after cleaning, reassemble the mold as a winding mold and remove the mold. There is a problem in that there is an operation of applying a release agent.

Further, since the winding mold is used many times, as the number of times of use increases, the deformation of the mold becomes large, which causes a problem of defective coil dimensions and cracking of resin. Was. Also, if there are many orders for models that use the same size of winding die at once, the number of installed dies is limited, so winding can not be done at once, and winding work may be stagnant, There is a problem that lead time is lengthened.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art. (1) Improvement of workability in manufacturing a resin mold coil (2) Use of a coil formed by a double use of a coil Improvement of cooling efficiency (3) Improvement of workability at the time of transformer assembling work by also using the former plate of the former (4) Maintenance of the former by also using the former of the former becomes unnecessary. Its purpose is to provide.

[0010]

In order to solve the above problems, a dry transformer according to the present invention comprises a coil housed in a coil, an iron core inserted in the coil, the coil and the iron core. And an upper and lower clamp for clamping the coil and the iron core. The upper plate and the upper and lower clamps cooperate to move the coil and the iron core together. In the transformer configured to hold firmly, the aforesaid plate has an arc-shaped cross section, and is formed of a thin plate having a predetermined length in the axial direction, and is provided at both ends in the longitudinal direction of the thin plate member, respectively. A joint is provided with the upper and lower fasteners of a length protruding from both ends of the coil, and a pair of the abutting plates are formed so as to face each other in an arc-shaped diametric direction to form a tubular body. When the iron core is inserted, it is configured to serve as a guide when the iron core is inserted. The one in which the features. The dry transformer according to the preceding paragraph, characterized in that the tubular body and the winding form are also used, and a coil is wound around the tubular body. The dry transformer according to the preceding paragraph, characterized in that a joint of the cylindrical body and the upper and lower fasteners are fastened by a fastening member and cooperated. The dry transformer according to the preceding paragraph, characterized in that the joining portion of the aforesaid plate is formed by bending one of the portions connected to the upper and lower fasteners at a right angle to the longitudinal direction of the coil. It is. The dry transformer according to the preceding paragraph, wherein the tubular body is made of a metal material having high thermal conductivity. Item 6. The dry type transformer according to Item 5, wherein at least one slit is provided in the cylindrical body so as to cut off a magnetic flux generated by a magnetic field generated by the coil. The dry transformer according to the preceding paragraph, wherein the upper and lower clamps are at least divided into two parts with respect to a yoke part of the iron core in a direction parallel to a magnetic field direction of the yoke part of the iron core.

The means for solving the above-mentioned problems will be specifically described. By using the coil winding form as this plate,
Eliminates mold removal after resin curing, reduces mold cleaning work and mold management man-hours, and protrudes joints for upper and lower clamps from the plates that abut each coil. By increasing the number of joints between the upper and lower fasteners and sharing the load during transportation and installation of the transformer, reinforcement by the stays of the lower fasteners is omitted, and a metal fitting with no welding is used. It is assumed that.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. [Embodiment 1] FIG. 1 is a schematic structural view of a dry-type transformer according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the dry-type transformer of FIG. B- of the dry transformer in FIG.
FIG. 4 is a schematic cross-sectional view of the plate of the dry transformer of FIG. 1 which also serves as a winding form, and FIG. 5 is a schematic view of the same plate also serving as another winding form of the dry transformer of FIG. FIG. 6 is a schematic explanatory view of a winding assembly using the corresponding plate of FIG. FIG.
FIG. 7 is a schematic explanatory view of a wound core wrap in the winding assembly of FIG. 6.

The present embodiment shows a dry transformer having a robust structure in which the periphery of the coil is resin-molded and fastened with upper and lower fasteners. As shown in FIGS. 1 and 2, in the transformer body T of the present embodiment, an upper fastener 8 and a lower fastener 9 for supporting the iron core 3 are used, and the two fasteners are connected. The two metal fittings are disposed inside the coil 1. As shown in FIG. 3, unlike the related art, the plate-cum-winding die 10 is configured to surround and support the iron core 3. The aforesaid plate 2 has a function of supporting the coil as well as a function of supporting the coil, so that the plate 2 is manufactured as one of the transformer main parts from the time of coil winding.

According to the present embodiment, if the casting method is to pot the upper and lower ends of the coil by using a resin having a high viscosity such as silicon as the resin to be filled, the mold can be simplified, and the winding mold and the transformer can be directly changed. It can be used as a metal fitting for fastening the container body. Therefore, it is not necessary to use a coil former
There is an advantage that the man-hour for cleaning the mold and the man-hour for managing the mold can be omitted. Also, if a material such as a metal having high thermal conductivity is used as the material of the plate 10 also serving as a winding form, an air layer is formed between the conductor of the winding 1 which is a heat generating portion and the plate 10 also serving as a winding form. The heat generated by the conductor of the winding 1 is easily transmitted to the winding form,
Further, heat is transmitted to the upper fastener 8 via the plate 10,
Since the surface of the upper clamp 8 also functions as a cooling fin, a transformer with high cooling efficiency can be manufactured.

Next, details of each component will be described. FIG. 4 and FIG. 5 show the winding and contact plate 10 in the resin molded coil of the present embodiment. From both ends of the winding, a joining member 11 for connecting the transformer upper clamp and the lower clamp.
Are protruding two each.

According to the present embodiment, a coil is formed by winding a conductor around the cylindrical molded product using a cylindrical molded product made of metal or an insulating material having a strength equivalent thereto, as a coil former. Things. FIGS. 4 and 5 particularly show the case where a metal-made winding and contact plate 10 is used. Since the coil 1 is wound around the outer surface of the contact plate 10, the wound iron core 3 is inserted inside. The plate 10 forms one turn with respect to the magnetic flux direction of the coil 1 to generate an electromotive force due to electromagnetic induction, causing a current to flow, thereby causing unnecessary heat generation and loss. By inserting one or two slits 13 for the purpose of avoiding this, the magnetic flux circuit can be completely cut off. In addition, FIG.
Shows the case of one.

A resin spacer 12 or the like is inserted into the slit 13 so that the end faces of the slit 13 do not come into contact with each other. As shown in FIG. 4, if only one slit 13 is provided, there is an advantage that the number of parts is reduced, but there is a slight difficulty in the workability of the winding form. Therefore, as shown in FIG.
If the number 3 is two, the winding form is divided into two parts, and the number of parts increases, but the workability is greatly improved. The embodiment of the above two winding forms is an example in which the material is metal. However, if the material is an insulating material having a strength equivalent to that of the metal, the slit 13 for interrupting the magnetic flux circuit in the winding form. It does not need to be applied to form a continuous cylindrical shape. In this case, a material manufactured from carbon fiber, an epoxy resin, or the like can be considered, and a winding die formed by using the material can not only be structurally strengthened but also reduce the weight of the transformer.

Referring to FIG. 6, a description will be given of a winding configuration at the time of winding work. As shown in FIG. 6, a winding jig 14 for attaching the winding form 10 to a winding shaft of a winding machine (not shown) at the time of winding work is attached to the mounting hole 2 of the winding joining member 11.
Attach to 0 'with bolts 20 (not shown, see FIG. 2). The winding jig 14 is for preventing the mold from being displaced or buckling during winding. Next, a sheet 15 impregnated with a semi-cured resin such as an epoxy resin is wound around the outer periphery of the former to serve also as bonding and insulation between the former and the electric wire, and then the electric wire is wound as a coil. It is preferable to remove the winding jig 14 when the coil 1 is completed, that is, after the resin is completely cured and the electric wire is fixed. Here, if the primary coil and the secondary coil are integrated with the coil 1, the former 10 can support the coil. With this configuration, there is no need to tighten the upper and lower fasteners 8 and 9 via the fixed seat 7 from above and below the coil 1.

FIG. 7 illustrates the operation of wrapping the wound core after completion of the coil. This is a step of inserting the iron core 3 into the hollow portion 17 inside the coil 1 and wrapping it. In the case of a conventional coil structure, the insulating layer on the inner periphery of the coil is exposed,
In addition, since the insulating layer has a thickness of about 1 to 2 mm, when the iron core 3 is inserted, the corners of the silicon steel plate of the iron core 3 slide on the inner wall of the coil 1 to damage the inner peripheral insulating layer of the coil 1. As a result, the insulation strength and the moisture resistance were sometimes reduced. However, according to the present embodiment, since the winding and abutment plate 10 made of a material having a strength equivalent to a metal is disposed on the inner periphery of the coil 1, this serves as a guide,
The iron core 3 can be inserted, and the coil 1 with stable quality can be supplied.

According to the present embodiment, the present invention can be applied not only to a wound core type transformer but also to a dry type transformer using a two-piece iron core or a joint, and a so-called cut core or the like. it can. After the wrapping of the iron core is completed, the upper fastener 8 and the lower fastener 9 are attached with bolts 20 (not shown) using the holes 20 'in which the winding jig 14 is attached as shown in FIG. At this time, the two bolt holes 20 ′ are provided in the joint member 11 so that the upper and lower fasteners 8 and 9 are attached so as not to rattle during vibration, lifting and unloading. That's why. By using the upper and lower fasteners 8 and 9, a welding-less structure can be obtained. Further, as another embodiment, when the winding and abutment plate 10, the upper fastener 8, and the lower fastener 9 are made of metal, they are not fastened by the bolt 20,
It may be bonded by simple spot processing, and the number of steps can be reduced.

Next, the shapes of the upper fastener 8 and the lower fastener 9 will be described. As shown in FIG. 4, when the material is metal and the number of slits is one as shown in FIG. 4, the upper clamp 8 and the lower clamp 9 electromagnetically make one turn at the yoke of the iron core 3 (see FIG. 1). It is necessary to divide the upper fastener 8 and the lower fastener 9 into two parts in parallel with the direction of the magnetic flux so as not to generate the electromagnetic induction electromotive force. FIG. 1 is an external view of a transformer assembled by using the upper and lower fasteners 8 and 9 divided into two parts. Since this metal fitting can be shared even if the core size is slightly different, it is easy to standardize.

Referring to FIGS. 8, 9, and 10, a dry-type transformer according to another embodiment of the present invention will be described. FIG. 8 is a schematic structural view of a dry-type transformer according to another embodiment of the present invention, FIG. 9 is a cross-sectional view of the dry-type transformer of FIG.
0 is a cross-sectional view of the dry transformer of FIG. Description will be made again with reference to FIG. When the winding material is a metal material and the number of slits 13 is two, even if the upper fastener 8 and the lower fastener 9 are a single plate, they do not form one turn, so that the upper fastener 8 and the lower fastener 9 are not formed. Need not be split into two. FIG. 10 shows two slits 13. The dry type transformer using the undivided upper fastener 8 and lower fastener 9 shown in FIG. 8 has a structurally strong strength. Therefore, the thickness of the upper fastener 8 and the lower fastener 9 is reduced. be able to.

Another modification of the present embodiment will be described with reference to FIG. FIG. 11 is a schematic explanatory view of a contact plate serving also as another winding form of the dry transformer according to the present invention. Wound form and contact plate 10
At least one of the joining members 11 is bent at 90 ° to the coil axis direction, and the upper clamp 8
Alternatively, it is joined to the lower fastener 9. Utilizing the surface bent at 90 °, the winding and abutment plate 10 and the coil 1 can be placed in a vertically orthogonal posture. This is because, in the manufacturing process, a posture in which the direction of the coil axis coincides with the vertical direction is preferable in order to uniformly apply heat during the curing process of a material using silicon or semi-cured resin, and thus the curing speed of the resin is increased. And coil deformation during curing can be prevented. Further, there is no need to change the coil posture again from the end of the winding to the assembly, and the coil 1 can be moved while being mounted on the pallet 18. FIG.
FIG. 4 is a schematic explanatory view showing a state where a coil 1 is mounted on the upper side.

Referring to FIG. 12, a process of assembling another dry transformer according to the present invention will be described. FIG. 12 is a schematic explanatory view of an assembling process of a dry type transformer using another plate according to the present invention. As shown in FIG. 12, when the cut core 19 divided into two parts is used in the assembling process, the lower clamp 9, the cut core 19, and the coil 1 are sequentially arranged so that the axial direction of the coil 1 becomes the suction vertical direction. The assembly method of dropping and stacking does not need to change the posture of the transformer until assembly is completed,
Suitable for automation. It goes without saying that the coil posture at this time is easy to assemble if the coil axis direction is vertical. The transformer manufactured as described above requires man-hours,
In particular, operations such as removal of the mold and cleaning of the mold can be omitted, and there is no need for a release agent conventionally required for removal of the mold, and no man-hours for managing the mold are required, so that an inexpensive product can be provided.

In addition, since there is no air layer between the winding conductor (heat generating portion) of the inner coil and the former and the former is in close contact, heat is easily transmitted to the former, and the material of the former is heat conductive. If a high metal or the like is used, it is directly connected to the upper clamp, so that heat is directly transmitted to the upper clamp and the surface area of the upper clamp acts as a cooling fin, so that a transformer structure with high cooling efficiency can be provided. .

[0026]

As described in detail above, according to the structure of the present invention, the following effects can be obtained by using the plate serving also as a winding form. (1) Improve workability in manufacturing resin mold coil (2) Improve coil cooling efficiency by also using this plate as a coil form (3) Improve workability in transformer assembling work (4) Maintenance of coil form is unnecessary become

[Brief description of the drawings]

FIG. 1 is a schematic structural view of a dry-type transformer according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of the dry transformer of FIG.

FIG. 3 is a sectional view taken along line BB 'of the dry transformer of FIG.

FIG. 4 is a schematic explanatory view of a plate serving also as a winding form in the dry transformer of FIG. 1;

FIG. 5 is a schematic explanatory view of a contact plate serving also as another winding form in the dry transformer of FIG. 1;

FIG. 6 is a schematic explanatory view of a winding assembly using the corresponding plate of FIG. 5;

FIG. 7 is a schematic explanatory view of a wound core wrap in the winding assembly of FIG. 6;

FIG. 8 is a schematic structural view of a dry transformer according to another embodiment of the present invention.

FIG. 9 is a sectional view taken along line AA ′ of the dry transformer of FIG.

FIG. 10 is a sectional view taken along line BB ′ of the dry transformer of FIG. 8;

FIG. 11 is an explanatory view schematically showing a contact plate serving also as another winding form in the dry-type transformer according to the present invention.

FIG. 12 is a schematic explanatory view showing a process of assembling a dry-type transformer using another plate according to the present invention.

FIG. 13 is a schematic internal structural view of a three-phase transformer in the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Coil 2 ... Contact plate 3 ... Iron core 4 ... Upper clamp 5 ... Lower clamp 6 ... Stay 7 ... Fixed seat 8 ... Upper clamp 9 ... Lower clamp 10 ... Winding and contact plate 11 ... Joint 12 ... Spacer 13 Slit 14 Winding jig 15 Semi-cured resin impregnated sheet 16 Coil support 17 Hollow 18 Pallet 19 Cut core 20 Bolt

Claims (7)

[Claims] 1. A coil housed in a coil form, an iron core inserted into the coil, an abutment plate provided between the coil and the iron core, and upper and lower clamps for holding the coil and the iron core. A transformer comprising a clamp, wherein the contact plate and the upper and lower clamps cooperate to hold the coil and the iron core firmly, wherein the contact plate has an arc-shaped cross section. Has, formed in a thin plate having a predetermined length in the axial direction, provided with a joint with the upper and lower fasteners of a length protruding from both ends of the coil at both ends in the longitudinal direction of the thin plate member, A pair of the corresponding plates, a cylindrical body is formed by opposing in an arc-shaped diametrical direction, the core is inserted into the cylindrical body, and the core is configured to be a guide when the core is inserted. Features a dry type transformer. 2. The dry-type transformer according to claim 1, wherein said tubular body and said winding form are combined, and a coil is wound around said tubular body. 3. The dry transformer according to claim 2, wherein a joint of the tubular body and the upper and lower fasteners are cooperated by being fastened by a fastening member. Dry transformer. 4. The dry-type transformer according to claim 3, wherein one of a connecting portion of the abutment plate and a portion connected to the upper and lower fasteners is bent at a right angle to a longitudinal direction of the coil. A dry-type transformer characterized by the following. 5. The dry transformer according to claim 2, wherein the tubular body is made of a metal material having high thermal conductivity. 6. The dry-type transformer according to claim 5, wherein at least one slit is provided in the cylindrical body so as to cut off a magnetic flux generated by a magnetic field generated by the coil. . 7. The dry transformer according to claim 5, wherein the upper and lower fasteners are at least divided into two parts with respect to a yoke part of the iron core in a direction parallel to a magnetic field direction of the yoke part of the iron core. And dry type transformer.