JP4860383B2 - Resin mold transformer - Google Patents

Description

  The present invention relates to a resin mold transformer.

  As a conventional resin mold transformer, a concave portion or a convex portion is formed on at least one of the opposing peripheral surfaces of the resin-molded cylindrical inner coil and outer coil, and the concave portion or the convex portion is made of rubber. An elastic spacer (spacer holding member) is attached with an adhesive so that the relative position of the inner coil and the outer coil does not shift due to vibration during transportation and operation. There is one that prevents the member from dropping (see, for example, Patent Document 1).

JP-A-5-101946

  However, according to the above-described conventional technology, since the concave portion or the convex portion is formed on at least one of the opposed peripheral surfaces of the inner coil and the outer coil, the thickness of the resin for molding the coil becomes uneven. For this reason, there is a problem that the resin casting processability is poor.

  In addition, the resin-molded coil has low dimensional accuracy and the distance between the opposed peripheral surfaces of the inner coil and the outer coil varies by about ± 5 mm. However, even if the spacer is made of rubber, the expansion / contraction amount is about 1 mm. In order to adjust, there is a problem that a plurality of types of spacers having different thicknesses must be prepared.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a resin mold transformer having good resin casting processability and easy spacer manufacturing management.

In order to solve the above-described problems and achieve the object, the present invention includes an outer coil that is resin-molded and formed into a cylindrical shape, and an inner side that is resin-molded and formed into a cylindrical shape and is installed in the outer coil. A coil and a fastener made of a bolt and a nut made of an insulator, arranged between opposing circumferential surfaces of the outer coil and the inner coil, and tightened by the fastener in a direction perpendicular to the tightening direction. A plurality of spacers made of an insulating elastic body that bulges and presses the peripheral surface to fix the outer coil and the inner coil to each other , and a taper portion on the bolt and the nut The spacer hole is pushed and widened by the wedge effect of the taper portion, and the spacer is bulged, and the spacer has a surface between the outer and inner coils. Wherein the unevenness to increase the creepage distance along the surface is formed.

  According to this invention, the resin casting processability is good, and there is an effect that a resin mold transformer in which the outer coil and the inner coil are firmly fixed can be obtained.

  Embodiments of a resin mold transformer according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a top view showing an embodiment of a resin mold transformer according to the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 shows Embodiment 1 of a spacer according to the present invention. 4 is a side view, and FIG. 4 is a side view showing a state in which the spacer of the first embodiment shown in FIG. 3 is tightened by a fastening tool and swells in a direction perpendicular to the fastening direction.

  As shown in FIGS. 1 and 2, a resin mold transformer 10 according to an embodiment includes a primary winding 1 as an outer coil wound in a rectangular tube shape and resin-molded, a primary winding 1 and a predetermined coil. A secondary winding 2 as an inner coil that is formed in a rectangular tube shape so as to be spaced apart from the spatial distance S, is resin-molded, and is concentrically installed in the primary winding 1, and a magnetic steel sheet are laminated to form a belt shape. And an iron core 4 formed and inserted into the secondary winding 2.

  If two resin mold transformers 10 shown in FIG. 1 and FIG. 2 are arranged and each iron core 4 is connected in a ring, a single-phase transformer is formed, and three resin mold transformers 10 are arranged, and each iron core 4 is arranged in a ring. If connected, it becomes a three-phase transformer.

  In the resin mold transformer 10 of the embodiment, an AC voltage of 6,000 V is normally input to the primary winding 1 and an AC voltage of 210 V is output from the secondary winding 2. The heat resistance class of the resin mold transformer 10 is F type (temperature rise limit: 95K) or H type (temperature rise limit: 135K). The resin molded coil is difficult to manufacture with precise dimensional accuracy, and the spatial distance S between the opposing circumferential surfaces of the primary winding 1 and the secondary winding 2 has a dimensional variation of about 20 ± 5 mm. .

  As shown in FIG. 3, the spacer 3 according to the first embodiment is formed to have a thickness of about 15 mm and a height of about 25 mm by cast molding of silicon rubber having high heat resistance and high weather resistance as an insulating elastic body. A bolt through hole is provided in the part, and the part is formed in a substantially quadrangular prism shape.

  The spacer 3 includes a bolt 3c that is screwed into the nut 3d through the bolt through hole of the spacer 3, and washers 3b and 3b that are fastened to the bolt 3c and the nut 3d to tighten the spacer 3. The bolt 3c, the nut 3d, and the washer 3b are made of an insulator such as an epoxy resin. The bolt 3c, the nut 3d, and the washer 3b constitute a fastening tool.

  When a plurality of spacers 3 are inserted between the opposing peripheral surfaces of the primary winding 1 and the secondary winding 2 and the bolts 3c are screwed into the nuts 3d, the spacers 3a are tightened, as shown in FIG. Since it is compressed in the tightening direction (height direction) and bulges in the direction perpendicular to the tightening direction (thickness direction), and the thickness can be increased from about 15 mm to about 25 mm, the tightening torque of the bolt 3c is adjusted. As a result, the primary winding 1 and the secondary winding 2 can be firmly fixed to each other with a desired strength.

  The rotation of the nut 3d when screwing the bolt 3c is performed by inserting a spanner (not shown) between the opposed peripheral surfaces of the primary winding 1 and the secondary winding 2 and gripping the nut 3d. it can.

  As shown in FIG. 1 and FIG. 2, the spacer 3 usually has four locations on the upper opening side and four locations on the lower opening side between the opposing planes of the primary winding 1 and the secondary winding 2, for a total of 8 locations. To place. The spacers 3 may be arranged in at least two opposing positions on either the upper opening side or the lower opening side, and padding different from that of the spacer 3 may be provided at other positions.

  The resin mold transformer 10 of the first embodiment has good resin casting processability, easy manufacturing management of spacers, and firmly fixes the primary winding 1 and the secondary winding 2 to each other with a desired strength. be able to.

Embodiment 2. FIG.
FIG. 5 is a side view showing a second embodiment of the spacer of the resin mold transformer according to the present invention.

  As shown in FIG. 5, the spacer 23 of the second embodiment is formed to have a thickness of about 15 mm and a height of about 25 mm by cast molding of silicon rubber having high heat resistance and high weather resistance as an insulating elastic body. A bolt through hole is provided in the part and formed into a substantially quadrangular prism shape, and a nut 3d is embedded in one end part and integrally molded.

  The spacer 23 includes a bolt 3c that is screwed into the nut 3d through the bolt through hole of the spacer 23, and a washer 3b that is fastened to the bolt 3c and fastens the spacer 23. The bolt 3c, the nut 3d, and the washer 3b are made of an insulator such as an epoxy resin. The bolt 3c, the nut 3d, and the washer 3b constitute a fastening tool.

  When a plurality of spacers 23 are inserted between the opposing circumferential surfaces of the primary winding 1 and the secondary winding 2 and the bolts 3c are screwed into the nuts 3d, the spacers 23 are tightened and tightening direction (height direction) Since the thickness can be increased from about 15 mm to about 25 mm, the primary winding 1 can be adjusted by adjusting the tightening torque of the bolt 3c. And the secondary windings 2 can be firmly fixed with desired strength.

  In the spacer 23 of the second embodiment, since the nut 3d is embedded in the spacer 23 and integrally molded, it is not necessary to stop the nut 3d when the bolt 3c is screwed.

Embodiment 3 FIG.
FIG. 6 is a perspective view showing a third embodiment of the spacer of the resin mold transformer according to the present invention.

  As shown in FIG. 6, the spacer 33 according to the third embodiment is formed by casting molding of silicon rubber having high heat resistance and high weather resistance as an insulating elastic body, and four rows of groove portions 33 e as concave portions and convex portions on the surface. Are formed in a substantially quadrangular prism shape with a thickness of about 15 mm and a height of about 25 mm.

  When a plurality of spacers 33 are inserted between the opposing peripheral surfaces of the primary winding 1 and the secondary winding 2 and the bolt 3c of the first embodiment is screwed into the nut 3d, the spacer 33 is tightened and the height is increased. Since the thickness can be increased from about 15 mm to about 25 mm, the primary winding 1 and the secondary winding 2 can be adjusted by adjusting the tightening torque of the bolt 3c. They can be firmly fixed to each other with a desired strength.

  Since the spacer 33 is formed with four rows of groove portions 33e and three rows of crest portions 33f, it is assumed that the primary winding 1 and the secondary winding 2 are fixed with a space distance of about 20 mm facing each other. The creepage distance along the surface of the spacer 33 is about 40 mm, which is about twice the spatial distance of 20 mm. Therefore, even if the space distance is about 20 mm and the spacer 33 is interposed, the dielectric strength voltage does not decrease.

Embodiment 4 FIG.
FIG. 7 is a longitudinal sectional view showing a fourth embodiment of the spacer of the resin mold transformer according to the present invention.

  As shown in FIG. 7, the spacer 43 of the fourth embodiment is formed into a substantially square pillar shape having a thickness of about 15 mm and a height of about 25 mm by casting molding of silicon rubber having high heat resistance and high weather resistance as an insulating elastic body. Is formed. Bolt through holes are provided at the center of the spacer 43, and both ends of the bolt through holes are tapered holes 43j and 43k.

  The bolt 43c has a tapered portion 43g formed under the head portion 43m, and a threaded portion 43h formed under the tapered portion 43g. The nut 43d has a tapered portion 43i formed on the head portion 43n. The tapered holes 43j and 43k and the tapered portions 43g and 43i have the same tapered shape. The bolt 43c and the nut 43 are made of an insulating material such as an epoxy resin and constitute a fastening tool.

  When a plurality of spacers 43 are inserted between the opposing peripheral surfaces of the primary winding 1 and the secondary winding 2 and the bolts 43c are screwed into the nuts 43d, the taper portions 43g and 43i of the bolts 43c and nuts 43d are Due to the wedge effect, the taper holes 43j and 43k of the spacer 43 are expanded and the spacer 43 is bulged in a direction perpendicular to the screwing direction (tightening direction) (thickness direction) to increase the thickness from about 15 mm to about 25 mm. Therefore, by adjusting the tightening torque of the bolt 43c, the primary winding 1 and the secondary winding 2 can be firmly fixed to each other with a desired strength.

  Since the spacer 43 of the fourth embodiment bulges in the direction perpendicular to the screwing direction (tightening direction) and the thickness direction due to the wedge effect of the taper portions 43g and 43i of the bolt 43c and nut 43d, the screwing torque of the bolt 43c Is small.

  As mentioned above, although Embodiment 1-4 was demonstrated, as an insulating elastic body, a nitrile rubber etc. can be used other than a silicon rubber, and the external shape of the spacer 3 is good also as a columnar shape other than a square pillar shape. Further, the primary and secondary windings 1 and 2 may be cylindrical instead of the rectangular tube shape, the primary winding may be an inner coil, and the secondary winding may be an outer coil.

  As described above, the resin mold transformer according to the present invention is useful as a transformer in which the outer coil and the inner coil are firmly fixed to each other.

It is a top view which shows embodiment of the resin mold transformer concerning this invention. It is a longitudinal section showing an embodiment of a resin mold transformer concerning the present invention. It is a side view which shows Embodiment 1 of the spacer of the resin mold transformer concerning this invention. It is a side view which shows the state which the spacer of Embodiment 1 was clamp | tightened with the fastener and swelled in the orthogonal | vertical direction with the fastening direction. It is a side view which shows Embodiment 2 of the spacer of the resin mold transformer concerning this invention. It is a perspective view which shows Embodiment 3 of the spacer of the resin mold transformer concerning this invention. It is a longitudinal cross-sectional view which shows Embodiment 4 of the spacer of the resin mold transformer concerning this invention.

Explanation of symbols

1 Primary winding (outer coil)
2 Secondary winding (inner coil)
3, 23, 33, 43 Spacer 3b Washer 3c, 43c Bolt 3d, 43d Nut 33e Groove (recess)
33f Mountain (convex)
43j, 43k Taper hole 43g, 43i Taper part 4 Iron core 10 Resin mold transformer

Claims (3)

An outer coil formed into a cylindrical shape by resin molding;
An inner coil that is resin-molded and formed into a cylindrical shape and installed in the outer coil;
A fastening tool comprising a bolt and a nut made of an insulator, disposed between opposing circumferential surfaces of the outer coil and the inner coil, and fastened by the fastening tool to swell in a direction perpendicular to the fastening direction; A plurality of spacers made of an insulating elastic body that presses the peripheral surface and fixes the outer coil and the inner coil to each other;
A tree butter mold transformer Ru provided with,
The bolt and nut are formed with a tapered portion, and the tapered hole of the spacer is expanded by the wedge effect of the tapered portion, and the spacer is bulged. The resin mold transformer is characterized in that irregularities for increasing the creepage distance along the surface of the spacer are formed. The resin-molded transformer according to claim 1 , wherein the nut is embedded and integrally molded in the spacer. The resin-molded transformer according to claim 1 , wherein the unevenness is formed by a plurality of grooves.

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