JPS6025877Y2 - Molded welding transformer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a molded welding transformer.

Molded welding transformers generally have a primary coil and a secondary coil.
Next, the coils were laminated with insulators arranged alternately, the outer peripheral surface of the laminated coil was molded with a synthetic resin molding material, and the core was attached to the laminated coil and stored in a storage case made of thin metal sheet. It is used in resistance welding machines, etc.

Molded coils are molded with a synthetic resin molding material for the purpose of insulating the outer peripheral surface of the laminated coil, but the thickness of this molding is usually the minimum thickness necessary for insulation in order to reduce material costs. is preferable.

Conventionally, the thickness of a molded coil is maintained by a gap formed between a molding die and a laminated coil.

Normally, in order to obtain the required mold thickness around the outer periphery of the laminated coil, when placing the laminated coil in the mold, place short strips of the same composition as the molding material at predetermined positions on both sides of the laminated coil, that is, at the four corners of both sides. A small piece of hard insulator is placed, and a molding material is injected into the gap formed by the thickness of the small piece of hard insulator, that is, the space formed between the mold and the laminated coil, which is the thickness of the mold. However, it is known to integrally mold the entire laminated coil together with a small piece of hard insulator.

In addition, when fixing the above-mentioned molded coil in a storage case, after attaching the iron core to the molded coil, place it in the storage case, and install it from the outside of the storage case at a position corresponding to the above-mentioned hard insulator small piece. Screw and insert multiple support bolts so that the tip of each support bolt comes into contact with each small piece of hard insulator buried in the mold, and firmly fix the molded coil so that it does not move within the case. It has been known.

Conventionally, the molded coil is screwed into the storage case, and the tip of the support bolt is brought into contact with a small piece of hard insulator to fix the position. Because it comes into contact with a small piece by applying a large surface pressure,
Small pieces of hard insulators with the same composition as the synthetic resin molding material cannot withstand strong surface pressure and may sink, and sometimes the molded coil may shift due to strong vibrations caused by electromagnetic repulsion that occurs when electricity is applied to a welding transformer. This could lead to an unexpected accident.

The present invention is intended to solve the above-mentioned drawbacks, and its gist is to mold a primary coil and a secondary coil, which are electrically insulated from each other and stacked, using a synthetic resin molding material. In a welding transformer in which an iron core is attached to the molded coil and this is housed in a storage case, hard synthetic resin fixing having the required length and width is embedded in both sides of the molded coil with a mold. A storage case for storing the molded coil in a predetermined position includes a stator and a stopper that is buried in contact with a predetermined position of the stator, and a storage case for storing the molded coil in a predetermined position. Then, a support bracket is installed to hold the molded coil.

Embodiments of the transformer according to the present invention will be described in detail below with reference to the drawings.

In addition, FIG. 1 is a perspective view showing the entire welding transformer of the present invention, and a partially broken cross section is shown to clarify the internal structure, and FIG. 2 is a perspective view showing the entire welding transformer of the present invention, and FIG. A cross section is shown.

As shown in the above drawings, the primary coil 1 and the secondary coil 2 are alternately stacked with insulators 3 interposed therebetween.

Hard synthetic resin stators 5 having the same composition as the synthetic resin molding material 4 are arranged on both sides of the laminated coil.

This stator 5 has a length and width approximately equal to each long side of the outer periphery of the coil.

On both sides of the laminated coil on which the stator 5 is arranged, abutment fittings 6 having concave portions at their tips are respectively arranged at positions (four corners) corresponding to support bolts to be described later of the stator.

This fitting 6 is made of a material such as brass, and is embedded together with the laminated coil in a synthetic resin molding material.

The iron core 7 usually has a two-piece structure, and is attached to a molded coil and fixed with a tightening band.

The molded coil with an iron core is stored in a storage case 8 made of a thin steel plate, and the ends of support bolts 9 screwed and inserted from both sides of the storage case into positions corresponding to the abutment fittings 6 are inserted into the abutment fittings 6. It is inserted into the recess of the metal fitting 6 and tightly tightened.

Next, FIGS. 3 and 4 are cross-sectional views showing how the molding die and the laminated coil are assembled in the process of molding the transformer according to the present invention.

When molding the outer periphery of the laminated coil, a molding die is prepared as shown in FIGS. 3 and 4.

This molding die is divided into two parts, a lower die 11 and an upper die 12.

These upper and lower molds 12 and 11 accommodate a ship bottom-shaped coil that has the minimum thickness required for insulating the outer peripheral surface of the laminated coil, that is, the sum of the outer circumferential dimension of the laminated coil and a gap e1 corresponding to the mold wall thickness described later. A section is formed.

Now, the laminated coil is housed inside the lower mold 11 with the hard synthetic resin stator 5 and the metal fittings 6 arranged on both sides, and these molds 11 and 12 are assembled in a middle shape and the periphery of the mold body is When the tightening bolt 10 provided at A gap e1 corresponding to the thickness of the mold is formed at a location where the stator 6 is in contact with the surface thereof.

In this way, the synthetic resin molding liquid is injected into this space e1, and the gap 14 formed around each stopper 6 is also filled with the molding liquid, so that the outer periphery of the laminated coil, the hard synthetic resin stator 5, the stopper 6, etc. At the same time, harden in a mold.

After molding, the iron core 7 is attached to the molded coil taken out from the mold as described above, and then placed in the storage case 8.
Fixed position inside.

In this case, the support bolts 9 screwed and inserted into predetermined positions of the storage case 8, that is, the four corners corresponding to each of the metal fittings 6, are inserted into the recesses of each of the metal fittings 6 embedded in the molded coil and tightened firmly. This makes it possible to reliably support the coil inside the storage case.

As described in detail above, according to the present invention, prior to molding, each long side of the outer periphery of the laminated coil is coated with the required length and width of a synthetic resin molding material having the same composition as the minimum thickness of the synthetic resin molding material required for insulation. The outer periphery of the laminated coil is molded at the same time with a hard synthetic resin stator placed in the stator and a metal fitting in contact with a predetermined position of the stator, so it can be screwed and inserted from both sides of the storage case. Since the support bolt can be tightened while being fitted into the recess of the abutment fitting that abuts the stator, the molded coil can be firmly supported at a predetermined position within the storage case, reducing the risk of accidents. It has the effect of being able to sufficiently cope with strong vibrations of electromagnetic repulsion when a welding transformer is energized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view including a fractured cross section of an example of the molded welding transformer of the present invention. FIG. 2 is a view taken along the line A-A' in FIG. FIG. 3 is a sectional view illustrating the state of assembly of the hollow mold and the laminated coil for explanation of the molding process of the transformer of the present invention. FIG. 4 is a view taken along the line BB in FIG. 3. Explanation of symbols, 1
...Primary coil, 2...Secondary coil,
3...Insulating plate, 4...Synthetic resin mold material, 5...Hard synthetic resin stator, 6...
...Metal fitting, 7...Iron core, 8...Storage case, 9...Support bolt.

Claims (1)

[Scope of utility model registration request] The primary coil and the secondary coil are stacked electrically insulated from each other.
In a welding transformer in which the next coil is molded with a synthetic resin molding material, an iron core is attached to the molded coil, and this is stored in a storage case, molds are placed on both sides of the molded coil. A hard synthetic resin stator having a required length and width is embedded in the stator, and a metal fitting is embedded in contact with the stator at a predetermined position, and the molded coil is stored in a predetermined position. Insert the tip into the recess of the above metal fitting into the storage case,
A molded welding transformer equipped with support bolts that clamp the molded coil.