JPS6366046B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to the contents of a transformer consisting of an outer iron laminated core and a coil block, and upper and lower parts 1 formed to be in close contact with the contents of the transformer via a spacer plate. This invention relates to an assembly method for storing the contents of a transformer in a pair of tanks.

In particular, for products such as power transformers for AC trains, which are constantly exposed to frequent load fluctuations, vibrations, and harsh conditions of acceleration, and which require extremely small size and weight, windings are used. A so-called form-fit transformer is used in which the mechanical force is borne by the tank without using structural members such as a frame for mechanically supporting the iron core. This type of transformer generally has a structure in which a coil block consisting of rectangular plate coils stacked in the axial direction is surrounded by an outer iron core with a rectangular cross section, making it easy to integrate the tank and transformer contents. On the other hand, the assembly method consists of assembling the transformer contents, pre-tightening and pressurizing each part of the transformer contents, and press-fitting the transformer contents into the tank. Requires advanced technology to assemble. Therefore, establishing a simple and reliable assembly method has become an important issue.

[Prior art and its problems]

FIG. 1 is a cross-sectional view of the main parts of a conventional form-fit transformer using an outer iron core, and FIG. 2 is a cross-sectional view taken along line A-A in FIG. In the figure, reference numeral 1 denotes a coil block (which may be formed of multiple layers of cylindrical coils) formed by stacking a plurality of rectangular plate-shaped coils 1a, 1b, 1c, etc. in the axial direction. The outer periphery of the coil block is insulated with insulators 2 and 3 such as pressboard or aromatic polyamide board. Reference numeral 4 denotes an outer iron type stacked core made by stacking magnetic steel plates so as to surround the coil block 1, and is composed of a main leg part 4a, a yoke part 4b, and a return leg part 4c, and a part of the magnetic steel plates in each part is arranged alternately. are stacked so that they overlap.
The contents of the transformer, consisting of a coil block 1 and an external iron core 4, are housed in close contact with a lower tank 7 and an upper tank 8 via spacer plates 5 and 6, and the coil block and bushing 9 are submerged in oil. A conductive connection is made by a lead wire 10.

Next, a conventional assembly method will be explained using FIGS. 1 and 2. First, in FIG. 1, a coil block 1 is compressed to a predetermined size using a plurality of axial pressing jigs (not shown) and heated and dried (referred to as pre-compression pressing). The protruding portion (hereinafter referred to as the coil ear) is gradually press-fitted into the lower tank 7 via the spacer plate 5 while partially removing the pressurizing jig. At this time, lower tank 7
A pedestal (not shown) is temporarily installed between the bottom plate of the coil block 1 and the lower surface of the coil block 1 to support the coil block 1 so that the upper surface of the lug matches the upper surface of the flange 7a of the lower tank 7. Next, on the plane formed by the flange 7a of the lower tank and the upper surface of the ear of the coil block 1,
The stacked iron core 4 is formed by sequentially stacking the yoke portion 4b and the return leg portion 4c. Furthermore, coil block 1
Spacer plates 5 and 6 are arranged around the upper ear and the iron core 4, and the upper tank 8 is compressed to a predetermined size using an axial pressing jig (not shown) in the same manner as described above. The contents of the transformer and the upper and lower tanks are integrated by press-fitting them so as to cover them from above and welding the lower flange 8a of the upper tank 8 and the upper flange 7a of the lower tank 7 airtightly. .

However, the electromagnetic mechanical force generated in the coil block during an external short circuit normally reaches 10 ⁵ Kg, so when assembling the transformer, the coil block must be applied with an axial pressure jig to a pressure equivalent to the mechanical force generated. It is necessary to perform the core stacking work and tank press-fitting work in a state that has been compressed and heated and dried in advance, that is, in a pre-tight pressurized state, and restrained by a tank so that the pre-tightened pressure does not loosen. However, since core loading work and tank press-fitting work must be carried out with a powerful axial pressing jig attached to the coil block, the work is unstable and inefficient, and the pre-tightening pressure is not sufficiently maintained. It was becoming difficult to press fit into the tank in this condition.

Furthermore, in order to restrict the pre-clamping force, the plate thickness of the tank (for example, section 8b) must be increased, which is a factor that hinders the reduction in size and weight of the transformer.

Furthermore, when the coil block is compressed using an axial pressing jig, the insulator 3 surrounding the outer periphery of the coil block swells to the outside of the coil, which has the disadvantage of interfering with core stacking work.
Furthermore, in order to facilitate the core stacking work, the core window area must be increased to increase the gap between the coil block and the core main leg and return leg, which increases the core size and core weight. There were drawbacks that hindered the ability to make transformers smaller and lighter.

In addition, if the spacer plate 6 dries up and shrinks during long-term operation due to the synthetic wood or press boat interposed between the outer stacked iron core and the upper tank, the various parts of the core will butt against each other due to vibrations and impacts from vehicles, etc. It had many drawbacks, such as creating gaps in the parts and deteriorating the magnetic properties of the iron core.

[Object of the invention] The present invention was made in view of the above-mentioned situation, and
The purpose of the present invention is to provide an efficient assembly method suitable for providing a small, lightweight, and highly reliable transformer that has excellent electromagnetic mechanical force resistance, vibration resistance, and impact resistance.

[Key points of the invention]

According to the present invention, the above-mentioned object is to form a partial core by combining the magnetic steel plates of each part except one yoke part, applying adhesive to the outer peripheral surface, and hardening while applying a load in the stacking direction. A coil block is inserted into the iron core, a predetermined surface pressure is applied in the axial direction of the coil block, and while this surface pressure is maintained, the whole is pre-tightened and dried at a predetermined temperature, and the remaining magnetic steel plate of the yoke is After the coil block is pressed in the axial direction from the outside of the yoke, the yoke is pressed in the stacking direction, and an adhesive is applied to the outer peripheral surface of the yoke and hardened to integrate it. The transformer contents are formed so that the axial surface pressure of the coil block is maintained by the external iron core, and the transformer contents are formed in close contact with each other through a spacer plate, and the transformer is placed in a divided tank. This was achieved by press-fitting the contents of the container.

[Embodiments of the invention]

Fig. 3 is a conceptual diagram for explaining an embodiment of the assembly method of the present invention, in which the direction of the BB cross section of the transformer contents in Fig. 2 is changed by 90 degrees (for example, the right side of Fig. 2 is facing down). This figure shows the state in which the assembly jig is attached. In the figure, reference numeral 21 is a partial core, in which the magnetic steel plates of the main leg, return leg, and other yoke of the outer iron stacked core are assembled into a predetermined shape, excluding one yoke. An adhesive is applied to the outer circumferential surface of the core except for the portion that engages with the core, and the core is heated and hardened while being pressed in the stacking direction to be integrated. In this case, if the core is heated to a predetermined temperature in advance and then the adhesive is applied, the viscosity of the adhesive decreases and the adhesive penetrates into the gaps between the magnetic steel plates, making it possible to form a partial core with high strength.

22a and 22b are frames, and the partial core 21 is placed at a predetermined position on the frame 22b with the yoke portion facing down, and the coil receivers 23a and 23b are connected to the frame by bolts 22c. Coil receiver 23a,
23b comes into contact with the yoke portion of the partial core 21 from the side to prevent the partial core from falling over, and its upper surface is formed to match the upper surface of the yoke portion. 24
is a coil block that is inserted into the main leg (not shown) of the partial core from above. At this time, the partial core 21 is fixed with adhesive and formed to a predetermined size, and the coil block 25 is not subjected to pre-clamping pressure in the axial direction as in the conventional method. (See Figure 2) does not bulge outside the coil surface, so the coil block 2
4 can be easily inserted into the partial core 21. Therefore, the window area of the iron core can be set to the minimum size taking into account the dimensional error of the coil block 24.

Next, the method of applying surface pressure in the axial direction to the coil block 24 is to first place first pressing jigs 25a and 25b, which are symmetrical in shape to the coil receivers 23a and 23b, on one axial end surface of the coil block 24. The coil receiver 23 and the first pressurizing jig 25 are connected to each other by a plurality of pressure holding bolts 26 having pressure regulators 26a, and are fastened at a predetermined pressure. A predetermined surface pressure in the axial direction is applied to the protruding ear portion of the coil block. Next, the second pressurizing jig 27 is connected to the pedestal 22a via a pressure holding bolt 28 having a pressure regulator 28a, and is supported and fixed above the partial core. Furthermore, a predetermined axial surface pressure is applied to the core penetrating portion of the coil block 24 using a large number of push screws 30 having pieces 29 connected to the second pressurizing jig. In this way, partial core 2
1 and the coil block 24 are integrated, and a predetermined surface pressure is applied to the entire surface of the coil in the axial direction of the coil block 24.

Next, the contents of the transformer formed as described above, with the pressurizing jig attached, are placed in a heating and drying oven maintained at a predetermined temperature, and the coil block is heated and dried (pre-tightening and pressurizing). At this time, the insulator shrinks during drying and the axial dimension of the coil block 24 shrinks, but the decrease in pre-clamping pressure due to this dimensional shrinkage is absorbed by the pressure regulators 26a and 28a, and the pre-clamping pressure is absorbed by the pressure regulators 26a and 28a, so that the pre-clamping pressure is maintained at a specified level even during drying. The coil block 24 is configured such that an axial load of 1 is applied to the coil block 24. After pre-tightening and pressurizing the transformer, the magnetic steel plates for the remaining yoke parts will be attached. This work begins by selecting the pieces 29a and 30a of the plurality of push screws 30 each having pieces 29 that apply axial pressure to the coil block 24.
is temporarily removed, a part 31 of the yoke magnetic steel plate is inserted into the ends of the main leg and return leg of the partial core 21, and the piece 29a and the set screw 30a are inserted into the yoke iron plate attached to the partial core. Attach the coil block 24 upwardly and press it with a predetermined pressure to press the coil block 24 in the axial direction. Next, loosen the push screw 30b and perform the same operation as described above. Repeat this operation one after another to form the outer iron stack core. Then, the yoke portion is pressed in the stacking thickness direction by a push screw 32 coupled to a first pressing jig. In this step, the installation start position and insertion order of the yoke iron plates may be arbitrary. Furthermore, it is clear that even if there are a plurality of main landing gear cores and coil blocks, the contents of the transformer can be assembled according to the above explanation.

Next, an adhesive is applied to the outer circumferential surface of the yoke portion inserted into the partial core 21 and pressed by a pressure jig to integrate it in the above-mentioned process and the engaging portion with the partial core, and hardened by heating. Epoxy or polyester adhesives with excellent heat resistance, oil resistance, and adhesive properties are suitable for bonding the cores, and the shear load of the core joints fixed using the method described above is A strength of up to 10 times the force, or 10 ⁶ Kg, can be obtained. Therefore, the pre-clamping pressure applied to the coil block penetrating the window of the outer iron laminated core is restrained by the laminated core, and during long-term operation of the transformer, the pre-clamping pressure applied to the coil block passing through the window of the outer iron laminated core is restrained by the intervening pressure between the core and the tank. Even if the spacer plate 6 loosens, the coil block 25 can maintain the pre-clamping pressure for a long period of time and maintain stable strength against external short circuits.

Next, the contents of the transformer assembled as described above are stored in a pair of upper and lower tanks. First, the coil receiver 23a and the first pressing jig 25a are removed, and the spacer plate 5 is cut diagonally as shown in FIG.
Pressure jig 25a and coil receiver 2
The remaining spacing plate 5b is attached to the axial end face of the coil block 24 after the coil block 3a is removed at a position facing the spacing plate 5a inside the lower tank. Next, lift up the contents of the transformer and remove the spacer plate 5a.
Insert the ear of the coil with attached into the lower tank. When the pressing jig 25a and the coil receiver 23a are removed, the axial pressure on the coil lugs is released, so the coil block lugs expand somewhat in the axial direction, but the spacer plate is cut diagonally. Therefore, when it is press-fitted into a fixed position in the lower tank, it is pressurized by the tank walls on both sides and is restrained at a predetermined axial pressure. Also, instead of using diagonally cut spacer plates, the pedestal 22a and the second pressure jig 2 are used.
7 may be provided with a push screw (not shown) to press the ear part of the coil block 24 in the axial direction and press fit the coil block into the lower tank. Furthermore, after pressing one ear of the coil block into the specified position of the lower tank as described above, the contents of the transformer are press-fitted by covering the upper tank from above using the same procedure as described above, and applying pressure between the upper and lower tanks. In addition, the flanges of the pair of upper and lower tanks are connected to each other while applying pressure in the stack thickness direction to the outer periphery of the outer iron stacked core, thereby completing the assembly.

〔Effect of the invention〕

As is clear from the above explanation, it has become semi-common practice to assemble a conventional form-fit transformer, in which a part of the pre-tightened and pressurized coil block is press-fitted and supported in the lower tank, and then the core is stacked. The manufacturing method used previously was to insert a coil block into a pre-formed partial core, then attach a pressurizing jig and pre-tighten and pressurize, and then press-fit the assembled transformer contents into a pair of upper and lower tanks. changed to As a result, the instability and inefficiency of the core stacking work, which had been a problem in the past, have been resolved, and the assembly work for the inside of the transformer can now be carried out efficiently and reliably.

In addition, in order to protect the coil from electromagnetic mechanical force acting on the coil block, the surface pressure applied in the axial direction of the coil block is restrained by the external iron core, which is firmly integrated with adhesive. Therefore, the iron plate 8b (see FIG. 1) surrounding the iron core of the upper tank 8 is not subjected to electromagnetic mechanical force. Therefore, the plate thickness can be reduced to about half of the conventional thickness, and the weight of the tank, which has been a problem in the past, can be reduced. In addition, even if electromagnetic mechanical force, vibration, acceleration, etc. act on the outer iron stacked core, the gaps between the joints of each part of the core do not expand, so there is a problem that the magnetic properties of the core deteriorate during long-term operation. can be solved.

In addition, in the past, the outer insulator of the coil block swelled due to pre-tightening pressure, which obstructed the stacking work of the core, so it was necessary to increase the gap between the coil block and the core legs. Since the coil block is inserted into the partial core that has been fixed to a predetermined size by the agent, pre-tightening pressurization is performed, so that the gap size can be reduced to a size determined mainly by the dimensional error of the coil block. This contributed to making the transformer smaller and lighter.

In addition, there is a pressing jig for applying pre-tightening force in the axial direction of the coil block, a first pressing jig that mainly presses the ear part of the coil block that protrudes laterally from the core window, and The second pressing jig mainly presses the interposed part of the coil block, so that the second pressing jig can be used directly on the end face of the coil block when inserting the upper yoke. It became possible to use a method of sequentially switching from pressurization to indirect pressurization via the upper yoke, making it possible to reliably press the coil block with a predetermined pressure. Also, when press-fitting the contents of the integrated transformer into the tank, most of the surface pressure on the coil block is restrained by the external iron core, which is fixedly formed to a predetermined size, so the pressing jig must be removed. The advantage was that there was little change in dimensions, making it easier to fill the tank.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view of a form-fit transformer for explaining the conventional transformer assembly method;
The figure is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a conceptual diagram for explaining an embodiment of the present invention. In the figure, 1, 24... coil block, 4
...Outer iron stacked core, 5, 6... Spacing plate, 7...
Lower tank, 8... Upper tank, 21... Partial iron core, 22... Frame, 23... Coil receiver, 25...
...First pressure jig, 27...Second pressure jig, 2
6, 28... pressure holding bolt, 30, 32... push screw, 29... piece.

Claims (1)

[Scope of Claims] 1. A method for assembling a form-fit transformer having a stacked outer iron core, which comprises combining magnetic steel plates of each part except one yoke part, applying adhesive to the outer circumferential surface, and applying a load in the stacking direction. After adding the adhesive, the adhesive is heated and hardened to form a partial core, a coil block is inserted into this partial core, and a predetermined surface pressure is applied in the axial direction of the coil block, and while this surface pressure is maintained, the whole is pressed into a predetermined position. Pre-tighten and dry at temperature, insert the remaining magnetic steel plate into the yoke, press the coil block in the axial direction from the outside of this yoke, then press the yoke in the stacking direction, An adhesive is applied to the outer circumferential surface of the yoke portion and cured to form a transformer interior in which the axial surface pressure of the coil block is maintained by the integrated outer iron core. A method for assembling a transformer having an external iron core, characterized in that the contents of the transformer are press-fitted into divided tanks that are formed so as to be in close contact with each other via a spacer plate. 2. In the method described in claim 1,
The step of applying a predetermined surface pressure in the axial direction of the coil block includes a first pressurizing jig that applies surface pressure to the laterally protruding portion of the iron core of the coil block, and a surface pressure applied to the core penetrating portion of the coil block. A second pressurizing jig that applies pressure is used, and the first pressurizing jig is connected to a pedestal on which the partial core is mounted via a pressure holding bolt having a pressure regulator and a coil receiver, so that the coil A surface pressure is applied to the block, the second pressurizing jig is supported above the transformer contents by a pressure holding bolt having a pressure regulator connected to a pedestal, and the second pressurizing jig is A method for assembling a transformer having an outer iron core, characterized in that surface pressure is applied to the core penetrating portion of the coil block by a plurality of push bolts attached to the fixture. 3. In the method according to claim 1 or 2, the step of inserting and pressing the yoke magnetic steel plate includes a plurality of presses applying axial surface pressure to the core penetrating portion of the coil block. Temporarily remove a part of the bolt, insert a part of the magnetic steel plate, reinstall the removed push bolt, apply surface pressure in the axial direction of the coil block from the outside of the inserted magnetic steel plate, and perform this operation. A transformer having an outer iron core, characterized in that all the magnetic steel plates are repeatedly inserted and pressed, and the yoke portion is pressed in the stacking direction by a push bolt attached to a first pressing jig. How to assemble the vessel.