CN113257527B

CN113257527B - Resin-cast dry-type distribution transformer and preparation method thereof

Info

Publication number: CN113257527B
Application number: CN202110435119.1A
Authority: CN
Inventors: 金正宁; 寻亚; 周鹏; 王康; 孙国平; 偶军
Original assignee: Zhenjiang Tianli Transformer Ltd corp
Current assignee: Zhenjiang Tianli Transformer Ltd corp
Priority date: 2021-04-22
Filing date: 2021-04-22
Publication date: 2022-06-07
Anticipated expiration: 2041-04-22
Also published as: CN113257527A

Abstract

The invention discloses a resin-cast dry-type distribution transformer and a preparation method thereof, and the dry-type distribution transformer comprises a box body, wherein cooling cavities and a working cavity are arranged in the box body, two groups of cooling cavities are arranged in the cooling cavities, an external heat dissipation structure is arranged at the position of the box body, which is positioned at the cooling cavities, a bottom heat dissipation box body is arranged at the bottom end of the box body, two groups of mounting seats are arranged at the bottom end of the bottom heat dissipation box body, an iron core is arranged in the working cavity, and a cooling box is arranged at one side, which is positioned at a low-voltage wire outlet end and a high-voltage wire outlet end, of the top end of the box body. The whole distribution transformer has good heat dissipation effect, and stable operation of the distribution transformer is ensured.

Description

Resin-cast dry-type distribution transformer and preparation method thereof

Technical Field

The invention relates to the technical field of dry-type distribution transformers, in particular to a resin-cast dry-type distribution transformer and a preparation method thereof.

Background

The main components of the transformer include a primary coil, a secondary coil, and an iron core (magnetic core). The transformer changes alternating voltage by utilizing electromagnetic induction phenomenon, and is mainly used for voltage transformation, current transformation, impedance transformation, isolation, voltage stabilization (magnetic saturation transformer) and the like in practical use, wherein the transformer has various types, and the dry-type transformer has the widest application range and is mainly used in places such as local illumination, high-rise buildings, airports, wharf CNC mechanical equipment and the like.

The resin-cast dry-type distribution transformer can generate a large amount of heat during working, so that the internal temperature of the resin-cast dry-type distribution transformer is raised, the resin-cast dry-type distribution transformer mainly depends on a radiating fan and radiating fins made of metal materials, the radiating effect is poor under the structure, the speed is low, and the dry-type distribution transformer in the state for a long time is easy to generate the phenomenon of unstable operation.

Disclosure of Invention

The invention aims to provide a resin-cast dry-type distribution transformer and a preparation method thereof, and aims to solve the problems that the existing resin-cast dry-type distribution transformer in the background art mainly depends on a radiating fan and a radiating fin made of a metal material, the radiating effect is poor, the speed is low, and the dry-type distribution transformer in the state for a long time is easy to generate unstable operation.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a resin casting dry-type distribution transformer and preparation method thereof, includes the box, be equipped with cooling chamber and working chamber in the box, cooling chamber is provided with two sets ofly, and cooling chamber sets up the both sides at the working chamber, the position that the box is located cooling chamber is provided with external heat radiation structure, the bottom of box is equipped with bottom heat dissipation box, two sets of mount pads are installed to the bottom of bottom heat dissipation box, be provided with the iron core in the working chamber, be provided with the coil assembly that the resin pouring formed on the iron core, low pressure leading-out terminal and high-pressure leading-out terminal are installed to the top of box, low pressure leading-out terminal and high-pressure leading-out terminal are connected with the coil assembly, one side that the box top is located low pressure leading-out terminal and high-pressure leading-out terminal is equipped with cooling box.

As further preferable in the present technical solution: the external heat radiation structure comprises external heat radiation pipes, electric push rods, built-in heat radiation pipes and folding pipes, the external heat radiation pipes and the built-in heat radiation pipes are all provided with a plurality of groups, the upper ends and the lower ends of the built-in heat radiation pipes are respectively connected with different external heat radiation pipes, the external heat radiation pipes are installed on the outer wall of the box body, the built-in heat radiation pipes are installed in the cooling cavity of the box body, the electric push rods are arranged on the outer wall of the box body, the top ends of the electric push rods are connected with the connecting plates, the connecting plates are connected with the external heat radiation pipes, and the two ends of the external heat radiation pipes are provided with the folding pipes.

As further preferable in the present technical solution: the temperature sensor is installed in the cooling cavity and is electrically connected with the electric push rod.

As further preferable in the present technical solution: the head and the tail of the built-in radiating pipe are connected with a liquid circulating pump through pipelines, and the liquid circulating pump is connected with a cooling box through a pipeline.

As further preferable in the present technical solution: the cooling box is internally provided with a heat-conducting liquid circulation cavity and an air conditioning manufacturing cavity, heat-conducting liquid is filled in the heat-conducting liquid circulation cavity, a micro refrigerator is installed in the air conditioning manufacturing cavity, a cooling pipe is arranged in the heat-conducting liquid circulation cavity, the cooling pipe is arranged in an S-shaped spiral mode, the head end and the tail end of the cooling pipe are arranged in the air conditioning manufacturing cavity, the cooling pipe is connected with a gas circulating pump, and the gas circulating pump is arranged in the air conditioning manufacturing cavity.

As a further preferred aspect of the present invention: the bottom heat dissipation box is internally provided with a mounting plate, the mounting plate is provided with a heat dissipation fan, the heat dissipation fan is provided with a plurality of groups, and the filter pad is arranged at the position where the bottom heat dissipation box is communicated with the working cavity.

As a further preferred aspect of the present invention: and the coil group is provided with a plurality of groups of clamping assemblies.

As further preferable in the present technical solution: the clamping component comprises an inner clamping piece, an outer clamping piece, an insulating pad, a connecting piece, a threaded rod, an outer nut and an inner nut, wherein the connecting piece is installed on the top ends of the inner clamping piece and the outer clamping piece perpendicularly, a fixing hole is formed in the connecting piece, the threaded rod penetrates through the threaded rod through threads of the fixing hole, the outer nut is connected with the two ends of the threaded rod in a threaded mode, the inner nut is arranged at a position, between the inner clamping piece and the outer clamping piece, of the threaded rod, and the insulating pad is arranged at a position, contacting with the coil assembly, of the inner clamping piece and the outer clamping piece.

As further preferable in the present technical solution: the inner clamping piece and the outer clamping piece are arc-shaped, and the folding piece is arranged in the middle of the inner clamping piece and the outer clamping piece.

A preparation method of a resin-cast dry-type distribution transformer comprises the following steps:

s1, preparing a mixed main material: grinding the silicon powder into 400 meshes, 500 meshes and 600 meshes, simultaneously drying the silicon powder and the coil, pouring the dried silicon powder into a mixing kettle, adding epoxy resin into the mixing kettle, uniformly mixing the epoxy resin and the silicon powder, heating to 75-82 ℃, simultaneously vacuumizing, and obtaining a mixed main material, wherein the vacuum degree is-0.08 to-0.1 MPa;

s2, preparing pouring liquid: adding a curing agent, a flame retardant and a plasticizer into the mixed main material, mixing and stirring for 40-90 minutes, heating while stirring to raise the temperature to 85-91 ℃, and heating for 200-300 minutes in a vacuum state at a vacuum degree of-0.08-0.1 MPa to prepare a pouring liquid;

s3, curing: placing the coil into a mold, adjusting the position, pouring a pouring liquid into the mold, fully contacting the pouring liquid with the coil, eliminating air bubbles in the coil, placing the poured mold into curing equipment for curing, curing for 140-300 minutes at the primary curing temperature of 90 ℃ plus or minus 5 ℃, and curing for 60-75 minutes at the secondary curing temperature of 110 ℃ plus or minus 5 ℃;

s4, assembling: after solidification, the coil formed by pouring in the die is taken out, cooled and subjected to circuit detection, the coil qualified in detection is assembled with the iron core in the distribution transformer, and all the components in the distribution transformer can be assembled in sequence.

The invention provides a resin-cast dry-type distribution transformer and a preparation method thereof, and the resin-cast dry-type distribution transformer has the following beneficial effects:

(1) according to the invention, the external heat dissipation structures controlled by the temperature sensors are arranged on the two sides of the box body, the bottom heat dissipation box body with a plurality of groups of heat dissipation fans is arranged at the bottom of the box body, when the box body is used, the heat dissipation fans are used for primarily dissipating heat, and when the temperature is too high, the external heat dissipation structures are reused to accelerate the heat dissipation speed and efficiency, so that the heat dissipation effect of the whole distribution transformer is good, and meanwhile, the stable operation of the distribution transformer is ensured.

(2) The external radiating structure is composed of the external radiating pipe and the internal radiating pipe which are mutually connected, the external radiating pipe and the internal radiating pipe are filled with heat conducting liquid, the external radiating pipe and the internal radiating pipe are connected with the cooling box through the liquid circulating pump, and when the cooling device is used, the cooled heat conducting liquid is sent into the external radiating pipe and the internal radiating pipe through the liquid circulating pump to circulate, so that the purpose of quickly radiating is achieved, and moreover, the electric push rod can drive the external radiating pipe to move forwards to open the folding pipe, so that the purpose of increasing a radiating path is achieved.

(3) According to the invention, the clamping assembly consisting of the inner clamping piece, the outer clamping piece, the connecting piece, the threaded rod, the outer nut and the inner nut is arranged on the coil assembly, the inner clamping piece and the outer clamping piece are attached to the inner wall and the outer wall of the coil assembly during installation, then the inner clamping piece and the outer clamping piece are fixed by the threaded rod, and the nuts are arranged on two sides of the connecting piece, so that the fixing effect is good, and the coil assembly is prevented from being layered.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic side view of the cross-sectional structure of the present invention;

FIG. 3 is a schematic view of an arrangement structure of the built-in heat dissipation pipe of the present invention;

FIG. 4 is a schematic view of the internal structure of the bottom heat dissipation case of the present invention;

FIG. 5 is a schematic view of the cooling box of the present invention;

FIG. 6 is a schematic view of the clamp assembly of the present invention;

fig. 7 is a schematic top view of the clamping assembly of the present invention.

In the figure: 1. a box body; 2. an external heat dissipation structure; 3. a bottom heat dissipation box body; 4. a mounting base; 5. a cooling box; 6. a liquid circulation pump; 7. a low-voltage outlet terminal; 8. a high-voltage outlet terminal; 9. a cooling cavity; 10. an external radiating pipe; 11. an electric push rod; 12. a radiating pipe is arranged in the radiator; 13. folding the tube; 14. a working chamber; 15. a filter pad; 16. a heat radiation fan; 17. mounting a plate; 18. an iron core; 19. a clamping assembly; 20. a coil assembly; 21. a temperature sensor; 22. a heat transfer liquid circulation cavity; 23. a cold air making cavity; 24. a micro refrigerator; 25. a gas circulation pump; 26. an inner clip; 27. an outer clip; 28. an insulating pad; 29. connecting sheets; 30. a threaded rod; 31. an outer nut; 32. an inner nut; 33. folding the sheet; 34. a connecting plate; 35. and (6) cooling the tube.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

as shown in fig. 1 to 7, the present invention provides a technical solution: the utility model provides a resin pouring dry-type distribution transformer, the power distribution box comprises a box body 1, be equipped with cooling chamber 9 and working chamber 14 in the box body 1, cooling chamber 9 is provided with two sets ofly, and cooling chamber 9 sets up the both sides at working chamber 14, box 1 is located the position in cooling chamber 9 and is provided with external heat radiation structure 2, the bottom of box 1 is equipped with bottom heat dissipation box 3, two sets of mount pads 4 are installed to the bottom of bottom heat dissipation box 3, be provided with iron core 18 in the working chamber 14, be provided with coil assembly 20 that the resin pouring formed on the iron core 18, low pressure leading-out terminal 7 and high-voltage leading-out terminal 8 are installed on the top of box 1, low pressure leading-out terminal 7 and high-voltage leading-out terminal 8 are connected with coil assembly 20, one side that box 1 top is located low pressure leading-out terminal 7 and high-voltage leading-out terminal 8 is equipped with cooling box 5.

In this embodiment, specifically: external heat radiation structure 2 includes external cooling tube 10, electric push rod 11, built-in cooling tube 12 and folding tube 13, external cooling tube 10 and built-in cooling tube 12 all set up the multiunit, and different external cooling tube 10 is connected respectively to the upper and lower both ends of built-in cooling tube 12, external cooling tube 10 is installed on 1 outer wall of box, built-in cooling tube 12 is installed in cooling chamber 9 of box 1, be equipped with electric push rod 11 on 1 outer wall of box, and connecting plate 34 is connected on the top of electric push rod 11, connecting plate 34 is connected with external cooling tube 10, the both ends flexion of external cooling tube 10 is equipped with folding tube 13, heat conduction liquid in external cooling tube 10 and the built-in cooling tube 12 takes out the heat in the box 1, reach the radiating purpose of cooling.

In this embodiment, specifically: the cooling cavity 9 is internally provided with a temperature sensor 21, the temperature sensor 21 is electrically connected with the electric push rod 11, the temperature sensor 21 is electrically connected with the liquid circulating pump 6, and the temperature sensor 21 is used for controlling the actions of the liquid circulating pump 6 and the electric push rod 11.

In this embodiment, specifically: the end to end of built-in radiating pipe 12 passes through pipe connection liquid circulation pump 6, and liquid circulation pump 6 passes through pipe connection cooling box 5, utilizes liquid circulation pump 6, eliminates the heat that the heat conduction liquid in external radiating pipe 10 and built-in radiating pipe 12 took out, carries external radiating pipe 10 and built-in radiating pipe 12 with refrigerated heat conduction liquid simultaneously in, continues to cool down the heat dissipation.

In this embodiment, specifically: a heat-conducting liquid circulation cavity 22 and a cold air making cavity 23 are arranged in the cooling box 5, heat-conducting liquid is filled in the heat-conducting liquid circulation cavity 22, a micro refrigerator 24 is arranged in the cold air making cavity 23, a cooling pipe 35 is arranged in the heat-conducting liquid circulation cavity 22, the cooling pipe 35 is spirally arranged in an S-shaped manner, the head end and the tail end of the cooling pipe 35 are arranged in the cold air making cavity 23, the cooling pipe 35 is connected with the gas circulating pump 25, the gas circulating pump 25 is arranged in the cold air making cavity 23, during the circulation process, the heat-conducting liquid in the internally radiating pipe 12 and the externally radiating pipe 10 absorbs the heat, and is conveyed into a heat-conducting liquid circulating cavity 22 in the cooling box 5, a micro refrigerator 24 in a cold air manufacturing cavity 23 cools the air, then, the heat transfer fluid is transported to the cooling pipe 35 by the gas circulation pump 25, and the heat transfer fluid in the heat transfer fluid circulation chamber 22 is cooled by the cooling pipe 35 and finally transported to the internally radiating pipe 12 and the externally radiating pipe 10.

In this embodiment, specifically: be provided with mounting panel 17 in the bottom heat dissipation box 3, install radiator fan 16 on the mounting panel 17, radiator fan 16 is provided with the multiunit, and filter pad 15 is installed with the position of working chamber 14 intercommunication to bottom heat dissipation box 3, utilizes radiator fan 16 to carry out preliminary heat dissipation, utilizes filter pad 15 to filter dust and steam simultaneously, effectual protection distribution transformer's inside electrical apparatus.

In this embodiment, specifically: the coil group 20 is provided with a clamping assembly 19, the clamping assembly 19 is provided with a plurality of groups, the clamping assembly 19 comprises an inner clamping piece 26, an outer clamping piece 27, an insulating pad 28, a connecting piece 29, a threaded rod 30, an outer nut 31 and an inner nut 32, the top ends of the inner clamping piece 26 and the outer clamping piece 27 are both vertically provided with the connecting piece 29, the connecting piece 29 is provided with a fixing hole, the thread of the fixing hole penetrates through the threaded rod 30, the two ends of the threaded rod 30 are in threaded connection with the outer nut 31, the threaded rod 30 is provided with the inner nut 32 at a position between the inner clamping piece 26 and the outer clamping piece 27, the insulating pad 28 is arranged at a position where the inner clamping piece 26 and the outer clamping piece 27 are in contact with the coil group 20, the clamping assembly 19 can be arranged on the coil group 20, during installation, the inner clamping piece 26 and the outer clamping piece 27 are attached to the inner wall and the outer wall of the coil group 20, the thread of the middle position of the threaded rod 30 is screwed into the two inner nuts 32, then the two ends of the threaded rod 30 penetrate through the fixing holes on the two groups of the connecting piece 29, then, an outer nut 31 is connected to the rear end of the threaded rod 30, and finally, the inner nut 32 is rotated so that the inner nut 32 abuts against the connecting piece 29, so that the threaded rod 30 is not easy to move after being installed.

In this embodiment, specifically: the inner clamping piece 26 and the outer clamping piece 27 are arc-shaped, the folding piece 33 is installed in the middle of the inner clamping piece 26 and the outer clamping piece 27, and under the action of the folding piece 33, the radian of the inner clamping piece 26 and the radian of the outer clamping piece 27 can be flexibly changed, so that the inner clamping piece and the outer clamping piece are suitable for different products.

It should be noted that, in operation, the external radiating pipes 10 are installed on the outer wall of the box body 1 side by side, and the two ends of the external radiating pipes 10 extend from the inside of the paper box body 1 to be connected with the internal radiating pipes 12, and the upper and lower ends of the internal radiating pipes 12 are connected with different external radiating pipes 10, and the head and tail ends of the internal radiating pipes 12 are connected with the liquid circulating pump 6, and the liquid circulating pump 6 is connected with the cooling box 5, in use, the multiple sets of radiating fans 16 in the bottom radiating box body 3 perform blowing and radiating from the bottom, when the temperature in the working cavity 14 is too high, the temperature sensor 21 starts the liquid circulating pump 6, the liquid circulating pump 6 injects the heat-conducting liquid in the cooling box 5 into the external radiating pipes 10 and the internal radiating pipes 12, and in the circulating process, the heat-conducting liquid in the internal radiating pipes 12 and the external radiating pipes 10 absorbs heat, and is transported to the heat conducting liquid circulation chamber 22 in the cooling box 5, the micro refrigerator 24 in the cool air making chamber 23 cools the air, then is transported to the cooling pipe 35 by the air circulation pump 25, the heat conducting liquid in the heat conducting liquid circulation chamber 22 is cooled by the cooling pipe 35, and finally is transported to the built-in radiating pipe 12 and the external radiating pipe 10, wherein, when the temperature detected by the temperature sensor 21 exceeds the set value, the electric push rod 11 is started, the electric push rod 11 is utilized to drive the connecting plate 34 to move the external radiating pipe 10, at this time, the folding pipes 13 at two sides of the external radiating pipe 10 are pulled open, thereby achieving the purpose of increasing the length of the external radiating pipe 10, facilitating the radiating speed, by arranging the external radiating structure 2 and the bottom radiating box body 3 with a plurality of groups of radiating fans 16 on the box body 1, primarily radiating by the radiating fans 16, and then utilizing the external radiating structure 2 to accelerate the radiating speed and efficiency, make whole distribution transformer radiating effect good, guarantee distribution transformer steady operation simultaneously, wherein, can install clamping component 19 on coil assembly 20, during the installation, with interior clamping piece 26, outer clamping piece 27 laminating at coil assembly 20 inside and outside wall, two interior nuts 32 of intermediate position screw in of threaded rod 30, then pass the fixed orifices on two sets of connection pieces 29 with the both ends of threaded rod 30, then at the trailing end connection outer nut 31 of threaded rod 30, at last interior nut 32 is rotating, make interior nut 32 lean on through connection piece 29, make threaded rod 30 difficult emergence after the installation remove, utilize clamping component 19 to press from both sides coil assembly 20 tightly, fixed effectual.

Example 2:

s4, assembling: and after solidification, taking out the coil formed by pouring in the mold, cooling, finally carrying out circuit detection, assembling the coil after qualified detection with the iron core in the distribution transformer, and finally completing the assembly of all the components in the distribution transformer in sequence.

The preparation method is not easy to generate bubbles when epoxy resin is used for pouring, the surface strength of the coil is improved, and the coil can be effectively prevented from cracking, deforming and the like when the preparation method is used in a later period.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a resin pouring dry-type distribution transformer, includes box (1), its characterized in that, be equipped with cooling chamber (9) and working chamber (14) in box (1), cooling chamber (9) are provided with two sets ofly, and cooling chamber (9) set up the both sides at working chamber (14), the position that box (1) is located cooling chamber (9) is provided with external heat radiation structure (2), the bottom of box (1) is equipped with bottom heat radiation box (3), two sets of mount pads (4) are installed to the bottom of bottom heat radiation box (3), be provided with iron core (18) in working chamber (14), be provided with coil group (20) that the resin pouring formed on iron core (18), low pressure leading-out terminal (7) and high pressure leading-out terminal (8) are installed to the top of box (1), low pressure leading-out terminal (7) and high pressure leading-out terminal (8) are connected with coil group (20), a cooling box (5) is arranged at one side of the top end of the box body (1) positioned at the low-voltage outlet end (7) and the high-voltage outlet end (8); the external radiating structure (2) comprises external radiating pipes (10), electric push rods (11), internal radiating pipes (12) and folding pipes (13), wherein multiple groups of external radiating pipes (10) and internal radiating pipes (12) are arranged, the upper ends and the lower ends of the internal radiating pipes (12) are respectively connected with different external radiating pipes (10), the external radiating pipes (10) are installed on the outer wall of the box body (1), the internal radiating pipes (12) are installed in a cooling cavity (9) of the box body (1), electric push rods (11) are arranged on the outer wall of the box body (1), the top ends of the electric push rods (11) are connected with connecting plates (34), the connecting plates (34) are connected with the external radiating pipes (10), and the folding pipes (13) are arranged at the bent positions of the two ends of the external radiating pipes (10); a temperature sensor (21) is arranged in the cooling cavity (9), and the temperature sensor (21) is electrically connected with the electric push rod (11); the head and the tail of the built-in radiating pipe (12) are connected with a liquid circulating pump (6) through a pipeline, and the liquid circulating pump (6) is connected with a cooling box (5) through a pipeline; a heat-conducting liquid circulating cavity (22) and a cold air making cavity (23) are arranged in the cooling box (5), heat-conducting liquid is filled in the heat-conducting liquid circulating cavity (22), a micro refrigerator (24) is installed in the cold air making cavity (23), a cooling pipe (35) is arranged in the heat-conducting liquid circulating cavity (22), the cooling pipe (35) is spirally arranged in an S-shaped disc shape, the head end and the tail end of the cooling pipe (35) are arranged in the cold air making cavity (23), the cooling pipe (35) is connected with a gas circulating pump (25), and the gas circulating pump (25) is arranged in the cold air making cavity (23); the coil group (20) is provided with a clamping assembly (19), and the clamping assembly (19) is provided with a plurality of groups; the clamping assembly (19) comprises an inner clamping piece (26), an outer clamping piece (27), an insulating pad (28), a connecting piece (29), a threaded rod (30), an outer nut (31) and an inner nut (32), wherein the connecting piece (29) is vertically installed at the top ends of the inner clamping piece (26) and the outer clamping piece (27), a fixing hole is formed in the connecting piece (29), the threaded rod (30) penetrates through the threaded rod (30) through the screw threads at the fixing hole, the outer nut (31) is connected with the two ends of the threaded rod (30) through screw threads, the inner nut (32) is arranged at the position, located between the inner clamping piece (26) and the outer clamping piece (27), of the threaded rod (30), and the insulating pad (28) is arranged at the position, in contact with the coil group (20), of the inner clamping piece (26) and the outer clamping piece (27); interior clamping piece (26), outer clamping piece (27) are the arc, and folding piece (33) are installed to the intermediate position of interior clamping piece (26) and outer clamping piece (27).

2. A resin-cast dry-type distribution transformer as claimed in claim 1, wherein: be provided with mounting panel (17) in bottom heat dissipation box (3), install radiator fan (16) on mounting panel (17), radiator fan (16) are provided with the multiunit, filter pad (15) are installed with the position of working chamber (14) intercommunication in bottom heat dissipation box (3).

3. A method of making a resin-cast dry distribution transformer as claimed in any one of claims 1 to 2, wherein: the method comprises the following steps: