JP2006100313A - Gapped iron core type reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of components as well as the height of a gapped iron core type reactor. <P>SOLUTION: Both ends of a retainer plate on the side where a clamp bolt passes through are programmed to remember to bend towards the axis of the leg of an iron core following a change in temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gap type core reactor in which a yoke core is joined to both ends of an iron core leg in which block iron cores and gap insulating members are alternately laminated in the axial direction, and a winding is wound around the iron core leg. In particular, the present invention relates to a gap-type core reactor that generates less noise.

The structure of a conventional cored reactor with a gap is, for example, as shown in FIG.
FIG. 6 is a front view showing a configuration of a conventional cored reactor with a gap. Three core legs 1 in which block cores 3 made of silicon steel plates and insulating members 2 for forming a gap are alternately laminated in the axial direction (vertical direction in the figure) are arranged side by side. Yoke iron cores 5 and 6 made of silicon steel plates are joined to both ends (upper and lower ends in the figure) of each iron core leg 1, and an iron core with a gap 20 is formed by the iron core legs 1 and the yoke iron cores 5 and 6. . Further, a winding 4 is wound around each iron core leg 1 to form a three-phase reactor. Holding plates 10 and 11 are arranged on the side of the anti-core leg 1 of the yoke iron cores 5 and 6, respectively, and fastening bolts 7 that pass through the holding plates 10 and 11 and are arranged in the axial direction of the iron core legs 1 are arranged. A bolt head 7A is formed at the lower end of the tightening bolt 7, and a screw is formed at the upper part. A tightening nut 8 is screwed into an upper end portion of the tightening bolt, and the iron core leg 1 and the yoke iron cores 5 and 6 are tightened via the holding plates 10 and 11. A correction member 13 is interposed between the tightening nut 8 and the pressing plate 10, and the use thereof will be described later.

  In a core-type reactor with a gap, noise and vibration generated from the iron core become a problem. There are two causes of noise and vibration: magnetic attraction and magnetic distortion. The magnetic attraction force causes an attraction force between the block cores 3 above and below the gap due to the magnetic flux passing through the gap of the iron core leg 1, thereby generating noise and vibration. In order to avoid this, it is necessary to firmly tighten the core leg 1 via the yoke cores 5 and 6. On the other hand, there are two types of magnetostriction: magnetostriction caused by magnetic flux flowing in the iron core and magnetostriction generated when excessive stress is applied to the silicon steel plate that constitutes the iron core. appear. In order to reduce this magnetostriction, it is necessary to set the magnetic flux density to an appropriate value and to prevent excessive stress from being applied to the silicon steel sheet. The iron core type reactor with a gap is tightened by the tightening bolt 7, but noise and vibration are generated unless the tightening force is set to an appropriate value.

Since the material constituting the cored reactor with a gap generates heat during operation, it expands and contracts according to the temperature, coefficient of thermal expansion, and length. 6 is made of a silicon steel plate material having a linear expansion coefficient of 12 to 15 × 10 ⁻⁶ (1 / ° C.). On the other hand, the fastening bolt 7 is made of an iron material having a linear expansion coefficient of 12 × 10 ⁻⁶ (1 / ° C.) or a stainless steel material having a linear expansion coefficient of 16 × 10 ⁻⁶ (1 / ° C.).
For example, assuming that the height of the gapd iron core 20 is the same as the length of the clamping bolt 7 and that the temperature of the clamping bolt 7 is 7 to the temperature 10 of the gapned iron core 20, the gapd iron core 20. The expansion coefficient in the height direction is 12 × 10 to 15 × 10 = 120 to 150, and the expansion coefficient in the length direction of the tightening bolt 7 is 12 × 7 = 84 to 16 × 7 = 112. The difference in dimensions between the gap-filled iron core 20 and the fastening bolt 7 is (120−112) ÷ 112 × 100 = 7% or (150−84) ÷ 84 × 100 = 79%. It extends from the tightening bolt 7. Even if the tightening force of the gap-provided core 20 at a low temperature is appropriate, the gap-provided core 20 is tightened by the tightening bolt 7 with a force on the specified value when the temperature becomes high. However, the above-mentioned calculated value varies depending on the temperature difference between the gapd iron core 20 and the tightening bolt 7, the ratio of the length between the iron core height and the tightening bolt 7, the type of material, and the like. In some cases, the gap extends from the gapd iron core 20.

A means for solving this problem is described in the following Patent Document 1.
That is, in Patent Document 1, a correction member 13 as shown in FIG. 6 is interposed between the tightening nut 8 and the holding plate 10, and the correction member 13 includes the thermal expansion of the iron core and the thermal expansion of the tightening bolt 7. It is shown that it is better to follow the difference between the two. When the tightening bolt 7 extends from the gapd iron core 20 due to a temperature rise, the correction member 13 that expands more than the difference between the expansion rate of the tightening bolt 7 and the expansion rate of the gapd core 20 is inserted, and the temperature becomes high. However, the tightening of the gapd iron core 20 does not loosen. In addition, when the iron core extends from the tightening bolt 7 due to a temperature rise, the tightening force of the iron core 20 with the gap can be reduced by using the correction member 13 as a spring member.
Japanese Patent Laid-Open No. 9-74023

However, the conventional gap cored reactor as described above has a problem in that a correction member must be interposed between the tightening nut and the holding plate.
That is, although the corrective member can surely set the tightening force of the iron core with a gap to an appropriate value, the number of parts is increased and the height of the iron core with a gap is increased by the length of the corrective member.
An object of the present invention is to reduce the number of parts and the height.

In order to achieve the above object, according to the present invention, a yoke iron core is joined to both ends of a core leg formed by alternately laminating block cores and gap insulating members in the axial direction, and wound around the core leg. A wire is wound, and a pressing plate is arranged on each side of the yoke core on the side of the anti-core core, and a clamping bolt that passes through the pressing plate on both sides and is aligned in the axial direction of the iron core leg is arranged. In a core-type reactor with a gap in which the iron core leg and the yoke iron core are fastened with a tightening nut that is screwed into a part, the tightening bolt penetrating side of the holding plate follows the temperature change on both sides of the iron core leg. It is good to memorize | store so that it may bend in the axial direction side.
In this configuration, the pressing plate may be made of a shape memory alloy. In this configuration, the pressing plate may be made of bimetal.

According to the present invention, the clamping bolt penetrating side of the holding plate is memorized so as to bend toward the axial direction of the iron core leg following the temperature change, so that even if the shrinkage difference between the gap iron core and the clamping bolt is different, the gap The iron core is tightened at a fixed value. As a result, the number of parts does not increase and the height of the core with gaps does not increase.
Further, in such a configuration, by making the pressing plate made of a shape memory alloy, the gapd iron core is clamped at a constant value even if the shrinkage difference between the gapd iron core and the clamping bolt is different. As a result, the number of parts does not increase and the height of the core with gaps does not increase.
Further, in this apparatus, by making the pressing plate made of bimetal, the gapd iron core is clamped at a constant value even if the shrinkage difference between the gapted iron core and the tightening bolt is different. As a result, the number of parts does not increase and the height of the core with gaps does not increase.

  The present invention is characterized in that the tightening bolt penetrating side of the press plate made of shape memory alloy is memorized so as to be bent on the axial direction side of the iron core leg on both sides following the temperature change. The configuration of the cored reactor with a gap according to the present invention will be described using examples, but the present invention is not limited to the examples.

FIG. 1 is a front view showing a configuration of a cored reactor with a gap according to Embodiment 1 of the present invention, and FIG. 2 is a side view of FIG. A holding plate 12 made of a shape memory alloy is directly clamped by a clamping nut 8. Others are the same as the conventional configuration in FIG. 6, so that the same components are denoted by the same reference numerals to avoid redundant description.
FIG. 3 is a side view showing only the pressing plate 12 of FIG. Clamping bolt through holes (not shown) are opened at the left and right ends of the pressing plate 12. The holding plate 12 is flat like a solid line 12A at room temperature, but is stored so that the left and right sides bend like a dotted line 12B when the temperature becomes high.
FIG. 4 is a side view of an essential part showing only the configuration in the vicinity of the upper part of FIG. This is an iron core type reactor with a gap in a normal temperature state, and is a state at the time of assembly, and the pressing plate 12 has a shape of 12A in FIG.

FIG. 5 is a side view of the main part when the configuration of FIG. 4 becomes high temperature. When the temperature rises, the height direction of the iron core 20 with the gap extends as shown by the arrow A and the length direction of the fastening bolt 7 also extends as shown by the arrow B. However, the elongation of the iron core 20 with the gap is larger than the extension of the fastening bolt 7. Even if it is large, the pressing plate 12 has the shape of 12A in FIG. 3, so that an excessive tightening force is not applied to the iron core 20 with a gap. When the temperature decreases, the state returns to the state shown in FIG. Therefore, even if the temperature rises and falls, the gapd iron core is always tightened at a constant value, and noise and vibration can be kept small. The number of parts and the height of the gap core are not increased.
The shape memory alloy of the presser plate 12 is preferably a Ni—Ti alloy. Ni-Ti alloys are generally excellent in strength, toughness (correspondence), corrosion resistance, and wear resistance.

Returning to FIG. 2, the case where the elongation of the gapd iron core 20 is smaller than the elongation of the tightening bolt 7 may be considered. In that case, the holding plate 12 may be turned over and stored so that the left and right sides of the holding plate 12 bend upward when the temperature is high. As a result, even if the temperature rises and falls, the gapd iron core is always tightened at a constant value, and noise and vibration can be kept small.
In FIG. 2, the pressing plate 11 may also be a shape memory alloy. In that case, the presser plate 11 is memorized so that the shapes on both the left and right sides move in the opposite direction to the presser plate 12. Further, as another embodiment of the present invention, a bimetal presser plate may be used instead of the shape memory alloy presser plate. The bimetal is obtained by fixing two plates having different coefficients of thermal expansion, and both the left and right sides rise and fall as shown in FIG.

  The present invention is used for a gap-type core reactor with less noise generated by storing the clamping plate penetrating side of the holding plate so as to bend in the axial direction of the core leg following the temperature change. It is possible to provide a core reactor with a gap and a small height.

The front view which shows the structure of the core-type reactor with a gap concerning Example 1 of this invention Side view of FIG. Side view showing only the holding plate of FIG. Side view of the main part showing only the configuration near the top of FIG. Side view of the main part when the configuration of FIG. Front view showing the configuration of a conventional cored reactor with a gap

Explanation of symbols

1: Iron core leg, 2: Insulating member, 3: Block iron core, 4: Winding, 5, 6: Yoke iron core, 7: Clamping bolt, 7A: Bolt head, 8: Clamping nut, 9: Correction member, 10, 11 , 12, 12A: holding plate, 20: iron core with gap

Claims (3)

A yoke iron core is joined to both ends of a core leg formed by alternately laminating block cores and gap insulating members in the axial direction, and a winding is wound around the core leg. Each of the presser plates is arranged, a clamp bolt that penetrates the presser plates on both sides and is aligned in the axial direction of the iron core leg is arranged, and the iron core leg and the above-mentioned by a tightening nut screwed to the end of the clamp bolt In a gap type core reactor in which a yoke iron core is clamped, the clamping bolt penetrating side of the pressing plate is memorized so as to bend to the axial direction side of the core leg following a temperature change on both sides. Features a cored reactor with a gap. 2. The gap type core reactor according to claim 1, wherein the pressing plate is made of a shape memory alloy. 2. The gap type core reactor according to claim 1, wherein the holding plate is made of a bimetal.

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