KR20110042086A - Cylindrical iron core, stationary induction apparatus and induction heat-generating roller device - Google Patents

Abstract

By reducing the gap in the entire cross section of the circular iron core of a stationary electromagnetic induction such as a transformer or a reactor, and suppressing iron loss caused by the leakage magnetic flux on the outer circumferential surface, the curved portion 211 having a curved cross section in the width direction is formed. Branches are provided with a plurality of iron core blocks 2 formed by laminating cylindrical iron core elements 2A, 2B, 2C formed by stacking a plurality of magnetic steel sheets 21 in the width direction alternately.

Description

Cylindrical iron core, static induction equipment and induction heating roller device {CYLINDRICAL IRON CORE, STATIONARY INDUCTION APPARATUS AND INDUCTION HEAT-GENERATING ROLLER DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circular iron core (cylindrical iron core) used in stationary induction equipment such as transformers or reactors, and induction heating equipment such as induction heating roller devices.

Loss of iron cores that become magnetic paths in stationary induction equipment such as transformers and reactors is a cause of deterioration of the efficiency and heat generation of the equipment, which is a major problem. In particular, the eddy current loss of the iron core due to the leakage magnetic flux occupies a large proportion, and the iron core generates heat by this eddy current, thereby reducing the efficiency of the apparatus. Moreover, it becomes a factor which causes the efficiency reduction of insulation coil wound around this, and insulation reduction. It is also known that the magnitude of the eddy current increases in proportion to the square of the width or the thickness of the magnetic steel sheet into which the magnetic flux enters vertically.

In order to shorten the length of the coil conductor wound around the iron core in this stationary induction apparatus, the iron core may be cylindrical. At this time, red iron cores (see Patent Literature 1) forming a cylindrical shape by stacking flat magnetic steel sheets having different widths as iron cores for stationary induction equipment (refer to Patent Document 1), and winding them round to form a cylindrical shape There are winding iron cores (see Patent Document 2) and radial iron cores (see Patent Document 3), which are formed by laminating radially flat magnetic steel sheets in a cylindrical shape. Moreover, in order to obtain a desired reactance by setting an appropriate magnetic flux density in these iron cores, a magnetic gap may be provided between iron cores (refer patent document 2).

However, in the hematite core disclosed in Patent Document 1, it is necessary to increase the type of magnetic steel sheets having different width dimensions in order to be close to the garden, and the problems such as high manufacturing cost and complicated assembly work are caused. have. Moreover, when a magnetic gap is provided, the leakage magnetic flux which penetrates radially from the iron core near the said gap and discharge | releases to the outside increases, but there exists a problem that an eddy current will generate | occur | produce by this leakage magnetic flux, and iron core will generate | occur | produce heat.

Moreover, in the winding core shown in patent document 2, it becomes a structure which exposes the whole flat part of the steel plate provided in the outermost periphery, the maximum value of the eddy current which arises by the penetration of a leakage magnetic flux is large, and iron loss increases. There is a problem. Moreover, this problem becomes remarkable when a magnetic gap is provided.

In addition, in the radial iron core shown in Patent Literature 3, the leakage magnetic flux passes through the cross section of the steel sheet, and the eddy current can be reduced, so that the heat generation amount of the iron core can be reduced, but the thin magnetic steel sheet is increased radially along a constant circumference. Laying is extremely cumbersome. Moreover, even if the inner end of each magnetic steel sheet is densely arranged, the space | gap is formed between the outer ends of the adjacent magnetic steel sheets. For this reason, in order to improve the spot ratio of an iron core, the operation | work which fills the space | gap etc. is carried out, for example, sandwiching a magnetic steel plate of another width | variety in the space | gap.

By the way, although it is not used for a stationary induction machine, as a core used for an induction heating device called an induction heating roller device, as shown in Patent Literature 4, a narrow width magnetic steel sheet having a curved portion whose cross section in the width direction forms a curved shape The applicant has considered a cylindrical iron core formed by stacking the beams alternately in the width direction. According to this, generation | occurrence | production of the eddy current by leaking magnetic flux through a magnetic steel sheet can be made small, and it becomes possible to reduce the heat generation amount of an iron core.

Since this cylindrical iron core stacks narrow magnetic steel sheets, there is a problem that the effective cross-sectional area to be a magnetic path is small, and from the viewpoint of improving the spot ratio, it is possible to consider simply increasing the width of the magnetic steel sheet. have. However, there is a problem that if the width dimension is simply increased, the outer diameter becomes large, so that the use to be used is limited. In addition, in order to reduce the outer diameter, it is conceivable to arrange the magnetic steel sheet to be as inclined as possible with respect to the radial direction. However, the area of the planar portion exposed to the outside of the magnetic steel sheet becomes large, and the generation of eddy current cannot be prevented. There is a problem.

Patent Document 1: Japanese Patent Application Laid-Open No. 62-30317 Patent Document 2: Japanese Patent Application Laid-Open No. 2001-237124 Patent Document 3: Japanese Patent Application Laid-Open No. 5-109546 Patent Document 4: Japanese Patent Application Laid-Open No. 2000-311777 Patent Document 5: Japanese Patent Application Laid-Open No. 9-232165 Patent Document 6: Japanese Utility Model Registration No. 2532986

Accordingly, the present invention has been made to solve the above problems at a glance, and the main sought problem is to suppress the deterioration of magnetic properties of iron cores such as iron loss by improving the droplet ratio and reducing the eddy current. will be.

That is, the iron core for stationary induction apparatus according to the present invention is formed by laminating a plurality of cylindrical iron core elements formed by stacking a plurality of magnetic steel plates having a curved portion whose cross section in a width direction crosses in the width direction in a concentric shape. It features.

As a specific embodiment, it is preferable that the cylindrical iron core element bends at a constant curvature in the radial direction of the diameter, and is formed by stacking a plurality of magnetic steel sheets having a width equal to or less than 1/4 of the diameter in the radial direction. . In this case, since the magnetic steel sheet is 1/4 width or less in diameter with respect to the radial direction, since the cylindrical iron core elements are sequentially stacked in the radial direction in a concentric shape, a circular iron core having a large cross-sectional area by a curved magnetic steel sheet is formed. It's simple to make.

As described above, according to the present invention, the iron core block is formed by stacking a plurality of cylindrical iron core elements concentrically, and can reduce the gap in the entire cross section of the circular iron core to improve the spot ratio, thereby reducing the iron loss.

In addition, the iron core for stationary induction apparatus according to the present invention comprises a plurality of cylindrical steel core elements formed by stacking a plurality of magnetic steel plates having a curved portion having a curved cross section in a width direction in the width direction, in a concentric manner. The effect is increased in the method of using the structure which has an iron core block and the magnetic gap provided between the said iron core block. In this way, the gap member increases or decreases the magnetic resistance in the magnetic path to obtain a desired reactance. When the magnetic resistance is increased, the magnetic flux of the leakage magnetic flux penetrating in the radial direction increases, but the leakage magnetic flux is equivalent. Generally, it passes along the width direction of the magnetic steel sheet provided substantially radially, and can reduce an eddy current. Further, the magnetic gap is formed between the iron core blocks formed by stacking the magnetic steel sheets alternately, thereby simplifying manufacturing and reducing manufacturing costs.

In addition, in order to simplify the formation of the magnetic gap and to further simplify the assembly of the iron core for the static induction apparatus, it is preferable that the magnetic gap is formed by sandwiching a gap member made of a nonmagnetic material between the iron core blocks.

In order to reduce the maximum eddy current value as much as possible, it is preferable that the widthwise length of the outer exposed portion at the side of the laminated side of the magnetic steel sheet constituting the cylindrical iron core element provided on the outermost side in the radial direction of the iron core block is equal to or less than the plate thickness of the magnetic steel sheet. Do.

As a specific embodiment for reducing the widthwise length s of the external exposed portion to be less than or equal to the plate thickness t of the magnetic steel sheet, the inner diameter Φ _A , the outer diameter Φ _B and the magnetic steel sheet Plate thickness t,

(Where α is the angle of inclination of the magnetic steel sheet with respect to the radial direction of the inner circle of the cylindrical iron core element, and θ 'is the center angle formed between the innermost edge of the adjacent magnetic steel sheet in the radial direction and the center of the circle. The unit of the function is in radians (rad).

When the center angle θ 'becomes equal to the center angle θ ₀ when the inclination angle of the magnetic steel sheet is zero, the inclination angle α of the magnetic steel sheet is θ _X ,

When the inclination angle α of the magnetic steel sheet is θ _X or less,

If the inclination angle α of the magnetic steel sheet is larger than θ _X , the center angle θ 'satisfying the above expression (1) is used.

To make a relationship.

As described above, according to the present invention, the reduction of magnetic properties of iron cores such as iron loss can be suppressed as much as possible by the improvement of the spot ratio and the reduction of the eddy current.

1 is a perspective view of an iron core for a stationary induction apparatus according to an embodiment of the present invention.
2 is a plan view of an iron core for a static induction apparatus of the same embodiment.
3 is a cross-sectional view showing a magnetic steel sheet of the same embodiment.
4 is a view showing the relationship between the plate thickness of the external exposed portion and the magnetic steel sheet.
5 is an enlarged schematic diagram (θ _21a = 0) showing the widthwise inner diameter side edge portion of the magnetic steel sheet.
Fig. 6 is a diagram showing the distances of the outer angles a-c in the case where the widthwise length of the outer exposed portion and the plate thickness of the magnetic steel sheet are the same.
7 is an enlarged schematic diagram (0 <θ _21a ) showing the widthwise inner diameter side edge portion of the magnetic steel sheet.
8 is a diagram illustrating a simulation result.
9 is a diagram illustrating a simulation result.
10 is a diagram for explaining derivation of the angle θ _X.
11 is a cross-sectional view showing a modification of the magnetic steel sheet.
It is a typical block diagram of the induction heating roller device using the cylindrical iron core of 2nd Embodiment.
It is sectional drawing of the cylindrical iron core of the same embodiment.
14 is a cross-sectional view showing a magnetic steel sheet of the same embodiment.
15 is a diagram showing the relationship between the plate thickness of the external exposed portion and the magnetic steel sheet.
It is a typical block diagram of the reactor using the cylindrical iron core of 2nd Embodiment.
Fig. 17 is a schematic configuration diagram of a letter-guided induction heating roller device.
18 is a cross-sectional view showing the structure of a conventional red iron core.

First Embodiment

Next, an embodiment of the iron core 1 for the static induction apparatus according to the present invention will be described with reference to the drawings. 1 is a perspective view which shows the outline of the structure of the iron core 1 for static induction equipment of this embodiment, and FIG. 2 is a top view of the iron core 1 of the static induction equipment.

The iron core 1 for stationary induction apparatus which concerns on this embodiment is a circular iron core used for a reactor or a transformer, for example. As shown in FIG. 1, between several iron core blocks 2X and these iron core blocks 2, FIG. It has a magnetic gap (G) provided in the.

As shown in FIG. 2, the iron core block 2 is formed by laminating a plurality of (three in this embodiment) cylindrical iron core elements 2A, 2B and 2C in a concentric circle in the radial direction. The cylindrical iron core elements 2A, 2B and 2C adjacent in the radial direction are provided in contact with each other. That is, the inner diameters of the adjacent cylindrical iron core elements 2A, 2B, 2C and the adjacent cylindrical iron core elements 2A, 2B, 2C are approximately the same. Specifically, among the three cylindrical iron core elements 2A, 2B and 2C, the iron core element installed on the inner diameter side is the first iron core element 2A, and the iron core element installed in the middle is the second iron core element 2B. In the case where the iron core element provided on the outer diameter side is the third iron core element 2C, for example, the outer diameter of the first iron core element 2A and the inner diameter of the second iron core element 2B are substantially the same. In addition, an insulating layer (not shown) is provided between the cylindrical iron core elements 2A, 2B, and 2C.

As shown in FIG. 2, the cylindrical iron core elements 2A, 2B, and 2C are formed in a cylindrical shape by stacking a plurality of magnetic steel plates 21 shifted in the width direction.

The magnetic steel plate 21 has a long shape, and as shown in FIG. 3, the magnetic steel plate 21 has a curved portion 211 having a curved cross section in a curved shape. The magnetic steel sheet 21 is formed of, for example, a silicon steel sheet having an insulating coating applied to its surface, and the sheet thickness thereof is, for example, about 0.3 mm.

The curved portion 211 may be considered to be curved at a constant curvature throughout, or to be curved while the curvature changes continuously. For example, an involute shape and a partial arc using a part of an involute curve may be considered. The shape or the partial elliptic shape can be considered.

And each magnetic steel plate 21 shifts in the width direction so that the convex part formed by the curved part 211 of the other magnetic steel plate 21 may be inserted in the recessed part formed by the curved part 211 of the magnetic steel plate 21. In this way, a plurality of magnetic steel sheets 21 forming the same shape are overlapped. At this time, the width direction edge parts 21a and 21b of the magnetic steel plate 21 are made to contact the concave side side or convex side side of the adjacent magnetic steel plate 21. As shown in FIG. In this manner, cylindrical iron core elements 2A, 2B, and 2C which form a cylindrical shape are formed.

The magnetic gap 3 is formed by sandwiching a gap member made of a nonmagnetic material so that the iron core block 2 is substantially coaxial between the iron core blocks 2. The gap member is formed of a nonmagnetic material such as aluminum, ceramic, glass, or the like and may have a flat plate shape or may have a columnar shape. In this embodiment, it forms the ring shape of substantially the same shape as the shape in plan view of the said iron core block 2. As shown in FIG.

Next, the manufacturing method of the iron core 1 for static induction equipment of this embodiment is demonstrated.

A cylindrical member or a cylindrical member (hereinafter referred to as a cylindrical member) having a predetermined outer diameter is prepared, and the outer peripheral surface thereof is brought into contact with the outer peripheral surface of the magnetic steel plate 21 in the widthwise inner diameter side end portion 21a. The first iron core element 2A is sequentially formed along the surface. After the stress relief annealing treatment, the first iron core element 2A is fixed and insulated by a varnish, an insulator, or the like. Next, the outer side of the first iron core element 2A is brought into contact with the outer peripheral surface side of the first iron core element 2A subjected to the fixing and insulation treatment in the widthwise inner diameter side end portion 21a of the magnetic steel plate 21. The second iron core element 2B is formed in order along the circumference. While maintaining the shape, the first iron core element 2A, the cylindrical member, and the like are removed from the second iron core element 2B, and the second iron core element 2B is subjected to the stress releasing annealing process, and then the first iron core element ( 2A) is inserted into the second iron core element 2B, and the second iron core element 2B is laminated along the outer circumferential surface of the first iron core element 2A. Then, by fixing and insulating with varnish, insulator or the like, a two-layer iron core is formed by the first iron core element 2A and the second iron core element 2B. In the case of forming a multilayer, the core core block 2 having any number of layers can be formed by repeating the above process on the outer peripheral surface of the second iron core element 2B. The iron cores 1 for stationary induction equipment are formed by stacking and fixing each iron core block 2 so as to be substantially coaxial, with a gap member between the iron core blocks 2 thus formed.

The obtained iron core 1 for stationary induction equipment is formed by radially equipping the magnetic steel plates 21 constituting the same, and a short circuit current is generated even when the coil is wound around the periphery of the iron core 1 for stationary induction equipment. In addition, like the radial iron core, the leakage magnetic flux passes through the inside of the magnetic steel plate 21 along the width direction thereof, and does not pass the magnetic steel plate in the thickness direction thereof. This suppresses the generation of eddy currents due to leakage magnetic flux. In addition, since the cross section of the iron core becomes roughly square, the length of the coil conductor to be wound can be made shorter, and resource saving can be achieved.

However, as shown in the partial enlarged view of FIG. 4, the iron core 1 for stationary induction apparatuses of this embodiment is a cylindrical iron core element (third iron core element) 2C provided in the radially outermost side of the iron core block 2. The magnetic steel sheet 21 is laminated so that the width direction length s of the external exposure part 21x at the side of the lamination side of the magnetic steel sheet 21 constituting the s) is equal to or less than the plate thickness t of the magnetic steel sheet 21. That is, when the plate | board thickness t of the magnetic steel plate 21 is 0.3 mm, the width direction length s of the external exposure part 21x shall be 0.3 mm or less.

The laminated side surface side of the magnetic steel plate 21 is the convex side side surface 21n of the curved part 211 among the side surfaces 21m and 21n which oppose the adjacent magnetic steel plate 21. The outer exposed portion 21x is a surface formed outside the widthwise outer diameter side end portion 21b of the magnetic steel sheet 21 in contact with the laminated side surface.

Moreover, as shown in FIG. 3, the inclination of the center line of the width direction inner diameter side edge part 21a of the magnetic steel plate 21 has the inclination of the inner circle | round | yen of the 3rd iron core element 2C. It is provided to have an inclination angle θ _21a with respect to the direction. That is, the width direction inner diameter side edge part 21a of the magnetic steel plate 21 is provided so that it may contact a position below plate thickness t toward the outer diameter direction from the width direction inner diameter side edge part 21a of the adjacent magnetic steel plate 21.

In the third iron core element 2C of the present embodiment, the inner diameter Φ _A , the outer diameter Φ _B of the third iron core element 2C, and the plate thickness t of the magnetic steel sheet 21 are:

(Where α is the inclination angle θ _21a of the magnetic steel plate 21 with respect to the radial direction of the inner circle of the third iron core element 2C, and θ 'is the edge of the innermost edge of the adjacent magnetic steel plate 21 in the radial direction. In addition, in the unit of the trigonometric function, the unit of the trigonometric function is radians (rad), where the center angle θ 'is equal to the center angle θ ₀ when the inclination angle θ _21a of the magnetic steel plate 21 is zero. When the inclination angle α (= θ _21a ) of the magnetic steel sheet 21 is θ _X , and the inclination angle α of the magnetic steel sheet 21 is θ _X or less,

When the inclination angle α of the magnetic steel sheet 21 is larger than θ _X , the center angle θ 'satisfying the above expression (1) is used.

It is configured to be a relationship.

As shown in Fig. 4, the relational expressions (Equation 2) and relational expressions (Equation 3) are formed by the widthwise length s of the external exposed portion 21x and the plate thickness t of the magnetic steel sheet 21 being s ≦ t. 3 shows the relationship between the inner diameter Φ _A and the outer diameter Φ _B of the iron core element 2C. Here, the inner diameter Φ _A of the third iron core element 2C is the diameter of a circle inscribed in the widthwise inner diameter side end portion 21a of each magnetic steel plate 21, and the outer diameter Φ _B of the third iron core element 2C is an angle. It is the diameter of the circle which circumscribes to the width direction outer diameter side edge part 21b of the magnetic steel plate 21 (refer FIG. 2).

For simplicity, the widthwise inner diameter side end portion 21a of the magnetic steel plate 21 is perpendicular to the inner diameter Φ _A of the third iron core element 2C (the inclination angle θ _21a of the centerline of the width direction inner diameter side end portion 21a). Is zero (θ _21a = 0), and an explanatory diagram thereof is shown in FIG. 5. At this time, the angle formed by the straight line connecting the edge of the widthwise inner diameter side end portion 21a of the magnetic steel plate 21 and the center of gravity O and the center line of the magnetic steel plate 21 (referred to as a straight line) is θ. _When 0/2 (rad) is set, the following relational expression is established.

The center angle of the magnetic steel sheet 21 and the sheet is θ ₀ , and the number of magnetic steel sheets 21 of the third iron core element 2C having an inner diameter Φ _A is N _0, and the magnetic angle of each magnetic steel sheet 21 is increased. In the case where the widthwise inner diameter side ends 21a are closely arranged without contacting each other,

Becomes

6, when the width direction length s of the external exposure part 21x is made to be equal to the plate | board thickness t, the vertex a and the vertex of the width direction outer diameter side edge part 21b of the magnetic steel plate 21 are shown. The distance between c is approximately φ _B π / N ₀ . Where, in right angle isosceles triangle abc,

Becomes

Here, by substituting (Equation 5) into (Equation 6),

If you put both sides together,

Becomes

And, the transformable θ _0/2 = tan a (formula 4) to the equation ⁽⁷⁾ Substituting ¹ (t / Φ _A), obtained expression of the equal sign in the expression (expression 2).

Next, in the case where the inclination angle θ _21a is zero (θ _21a = 0), the condition for s <t is considered.

At this time, in the right triangle abc,

Becomes

Here, substituting (Equation 5) into (Equation 8),

Becomes

And, the transformable θ _0/2 = tan a (formula 4) to (Formula ⁹⁾ Substituting ¹ (t / Φ _A), the inequalities in the relationship (Equation 2) can be obtained.

In addition, in the case where the inclination angle θ _21a is 0 <θ _21a <θ _X , the condition for s = t is considered.

First, the angle θ _X will be described. The angle θ _X is the angle of inclination of the magnetic steel plate 21 when θ 'becomes equal to the center angle θ ₀ at an angle formed between the corner of the innermost end of the radial direction of the adjacent magnetic steel plate 21 and the center of gravity O. Degrees θ _21a ,

Is the inclination angle of the magnetic steel plate 21 when the center angle θ 'becomes equal to the center angle θ ₀ . This θ _X is smaller than the center angle θ ₀ when the inclination angle θ _21a of the magnetic steel plate 21 is 0 <θ _21a <θ _X. On the other hand, when the inclination angle θ _21a of the magnetic steel sheet 21 is θ _X <θ _21a , the angle θ 'is larger than the center angle θ ₀ . In addition, the derivation of (Equation 1) and θ _X will be described last.

At this time, when the number of laminated sheets of the magnetic steel sheet 21 is N ＇, N＇> N ₀ , and as shown in FIG. 7, the corners and the center of gravity of the innermost ends of the adjacent magnetic steel plates 21 in the radial direction O are shown in FIG. 7. Θ 'is an angle θ'<θ ₀ .

That way,

In addition,

Becomes

From (Formula 10) and (Formula 11),

If you put both sides together,

Becomes

This (Equation 12),

Becomes

That is, the inclination angle range in which the θ _21a meets the outside diameter Φ _B to be a 0 <θ _21a s = t in the range of <θ _X of the magnetic steel plate 21 is also θ _21a is θ _21a inclination angle of the magnetic steel plates 21 It includes the range which satisfies the outer diameter Φ _B for s = t when = 0. Therefore, when the inner diameter Φ _A , the outer diameter Φ _B and the plate thickness t satisfy the inequality of the relational expression (Equation 2), the inclination angle θ _21a of the magnetic steel sheet 21 is in the range of 0 <θ _21a <θ _X. In this case, s = t.

Next, in the case where the inclination angle θ _21a is 0 <θ _21a <θ _X , the condition for s <t is considered.

At this time, in the right triangle abc,

Becomes

Substituting (Eq. 11) into (Eq. 13),

Becomes

This (Eq. 14),

Becomes

That is, the inclination angle θ _21a in the range satisfying the outer diameter Φ _B to be a 0 <θ _21a s <t in the range of <θ _X of the magnetic steel plate 21 is also θ _21a is θ _21a inclination angle of the magnetic steel plates 21 In the case of = 0, the range satisfying the outer diameter Φ _B for s <t is included. Therefore, when the inner diameter Φ _A , the outer diameter Φ _B and the plate thickness t satisfy the inequality of the relational expression (Equation 2), the inclination angle θ _21a of the magnetic steel sheet 21 is in the range of 0 <θ _21a <θ _X. In this case, s <t.

Next, when the inclination angle θ _21a is θ _21a = θ _X , the conditions for s = t and s <t are considered. At this time, since θ _X = θ ₀ , in each case, the same conditions as for s = t and s <t in the case of θ _21a = 0 are described.

Next, when the inclination angle θ _21a is larger than θ _X (θ _21a > θ _X ), the condition for s = t is considered.

At this time, when the number of laminated sheets of the magnetic steel sheet 21 is N ＇, N＇ <N ₀ , and as shown in FIG. 7, the corners and the center of gravity of the innermost ends of the adjacent magnetic steel plates 21 in the radial direction O are shown in FIG. 7. ) is> ₀ θ ', θ when the "the angle θ of the. Moreover, if the distance of vertex A and vertex A 'is made into virtual plate | board thickness t ＇,

therefore,

In addition,

Becomes

From (Formula 16) and (Formula 17),

If you put both sides together,

Becomes

Substituting (Eq. 18) into (Eq. 15),

Becomes

Here, by cosine theorem in triangle OAA ',

이고,

ego,

Becomes

Then, by substituting (Formula 20) into (Formula 19), an equal sign in the above relational formula (Formula 3) is obtained.

Next, when the inclination angle θ _21a is larger than θ _X (θ _21a > θ _X ), the condition for s <t is considered.

At this time, in the right triangle abc,

Becomes

Substituting (Eq. 17) into (Eq. 21),

Becomes

Then, when (15) and (20) are substituted into (22), an inequality in the relational formula (3) is obtained.

From the above, by selecting the inner diameter Φ _A , the outer diameter Φ _B , and the plate thickness t of the third iron core element 2C satisfying the above relation, it is possible to produce the third iron core element 2C such that s ≦ t.

As a specific example, when the inclination angle α of the magnetic steel sheet 21 is θ _X or less, for example, the inner diameter Φ _A of the third iron core element 2C is 550 (mm), the outer diameter Φ _B is 600 (mm) and the magnetic When the plate | board thickness t of the steel plate 21 is 0.3 (mm), it becomes outer diameter (phi) _B (= 600) <777.8.√2x0.3 / (tan- ¹ (0.3 / 550)). Therefore, using the magnetic steel plate 21 having a plate thickness t of 0.3 (mm) under the condition that the inclination angle α of the magnetic steel plate 21 is θ _X or less, the inner diameter Φ _A 550 (mm) and the outer diameter Φ _B 600 (mm In the case where the third iron core element 2C of) is manufactured, the third iron core element 2C having a widthwise length s of the external exposure portion 21x smaller than the plate thickness t is possible.

When the inclination angle α of the magnetic steel sheet 21 is larger than θ _X , for example, the inner diameter Φ _A of the third iron core element 2C is 550 (mm), the outer diameter Φ _B is 600 (mm), and the magnetic steel sheet. When the plate | board thickness t of (21) is 0.3 (mm) and the virtual plate | board thickness t 'calculated | required from said Formula (1) is 0.35 (mm), outer-diameter Φ _B (= 600) <666.7 ≒ √2 * 0.3 / ( tan ^-1 (0.35 / 550)). Therefore, under the condition that the inclination angle α of the magnetic steel sheet 21 is larger than θ _X , the magnetic steel sheet 21 having a plate thickness t of 0.3 (mm) is used to make the inner diameter Φ _A 550 (mm) and the outer diameter Φ _B 600 ( In the case where the third iron core element 2C of mm) is manufactured, the third iron core element 2C having a widthwise length s of the external exposure portion 21x smaller than the plate thickness t is possible.

In addition, a simulation result is shown in FIG. 8 in order to show the relationship of the inner diameter phi _A and the outer diameter phi _B in the case where s = t. 8 shows the relationship between the inner diameter Φ _A when the outer diameter Φ _B is fixed at 60 and the coefficient a is changed in the involute curves (x = a (cosθ + θsinθ) and y = a (sinθ−θcosθ)). It is a figure which shows. Moreover, (theta) to become s = t is 1.25 pi, 3.25 pi, and 5.25 pi.

As can be seen from FIG. 8, when the outer diameter Φ _B is 60, the minimum value of the inner diameter Φ _A is about 42.6 (= 21.3 x 2). That is, the ratio of the inner diameter / outer diameter to s = t is Φ _A / Φ _B > 42.6 / 60 = 0.71.

In addition, a simulation result is shown in FIG. 9 in order to show the relationship between the inner diameter phi _A and the outer diameter phi _B in the case where 2s = t. In the case of changing the coefficient a in the involute curve (x = a (cosθ + θsinθ), y = a (sinθ-θcosθ), as shown in Fig. 8, the outer diameter Φ _B is fixed at 60 as in Fig. 8 above. It is a figure which shows the relationship of the internal diameter (phi) _A of the. Moreover, (theta) to become 2s = t is 1.25 pi, 3.15 pi, and 5.15 pi.

As can be seen from FIG. 9, when the outer diameter Φ _B is 60, the minimum value of the inner diameter Φ _A is about 53.7 (= 26.85 × 2). That is, the ratio of the outer diameter / inner diameter to 2s = t is Φ _A / Φ _B > 53.7 / 60 = 0.895. Thus, from the simulation results, it is thought that the ratio of the inner diameter / outer diameter to be s ≦ t needs to be Φ _A / Φ _B > 0.71.

Finally, the derivation of the angle θ _X will be described with reference to FIG. 10. First, the geometric information is described analytically.

Surface L ₁ passing through point A (R (= Φ _A / 2), 0) of the first magnetic steel sheet shown in FIG.

L ₁ : f (x, y) = 0

Leave as.

In addition, the surface L ₂ of the second magnetic steel sheet adjacent to the first magnetic steel sheet uses the rotation angle θ 'of the center,

L ₂ : g (f (x, y), θ ') = 0

It can be represented as

Since this surface L ₂ is in contact with the first magnetic steel plate at the point B (x _b , y _b ),

g (f (x _b , y _b ), θ ') = 0

This holds true.

Hereinafter, it is assumed that the cross-sectional shapes of the surfaces L ₁ and L ₂ are straight lines. If α is the angle between L ₁ and the x-axis, the function f is geometrically expressed as

L ₁ f (x, y) = y- (xR) tan (-α) = 0

Therefore, L ₂ becomes the following formula.

L ₂ g (f (x, y), θ ') = y-Rsinθ' (s-Rsinθ ') tan (θ'-α) = 0

In addition, when the thickness of the steel sheet is t, the coordinates of the point B are (R + tsinα, tcosα). Substituting the coordinates of this point B into the equation L ₂ ,

tcosα-Rsinθ- (R + tsinα-Rcosθ) tan (θ-α) = 0

Becomes

By this equation, α obtained by giving the inner diameter R (= Φ _A / 2) and the plate thickness t and making θ '= θ ₀ is θ _X.

<Effect of 1st Embodiment>

According to the iron core 1 for static induction apparatus according to the present embodiment configured as described above, the iron core block 2 is formed by laminating a plurality of cylindrical iron core elements 2A, 2B, and 2C on concentric circles, and improves the spot ratio. It can reduce the iron loss. In addition, the gap member 3 increases or decreases the magnetoresistance in the magnetic path to obtain a desired reactance. When the magnetoresistance is increased, the magnetic flux amount of the leakage magnetic flux penetrating in the radial direction increases, but the leakage magnetic flux is increased. The silver passes through the widthwise direction of the magnetic steel sheet 21 which is provided in an approximately radial manner, and the eddy current can be reduced. In addition, the structure in which the gap member 3 is sandwiched between the iron core blocks 2 formed by stacking the magnetic steel plates 21 alternately can simplify manufacturing and reduce manufacturing costs.

<Other modified embodiments>

In addition, this invention is not limited to the said embodiment. In the following description, the same code | symbol is attached | subjected to the member corresponding to the said embodiment.

For example, in the said embodiment, although the direction in which each cylindrical iron core element overlaps is the same, you may make the direction of lamination | stacking between each cylindrical iron core element reverse.

In addition, in the above embodiment, the iron core block is composed of three cylindrical iron core elements, but may be composed of two cylindrical iron core elements or four or more cylindrical iron core elements. That is, the iron core for stationary induction equipment may be comprised of two or more cylindrical iron core elements according to the use.

In addition, in the said embodiment, although the magnetic steel plate 21 consisted only of the curved part 211, as shown in FIG. 11, the curved part 211 and the inner diameter side edge part in the width direction of the said curved part 211 are continuous. It may consist of the formed bent part 212. At this time, the bending angle θ of the curved portion 212 with respect to the curved portion 211 is, for example, 30 degrees, the length is preferably as short as possible, for example, about 3 to 10 times the thickness of the magnetic steel sheet 21 Is preferred. Thus, if the bent part 212 is provided, it is not only possible to facilitate the operation of stacking the respective magnetic steel plates 21, but also preferably prevents the magnetic steel plates 21 from being detached from the radially outer side. can do.

&Lt; Second Embodiment >

Next, a description will be given of a second embodiment of a cylindrical iron core, an induction heating roller device and a stationary induction device which can preferably suppress eddy currents.

Loss of iron cores that become magnetic paths in electromagnetic induction equipment such as transformer or reactor, or induction heating equipment such as induction heating rollers, causes the efficiency of electromagnetic induction equipment and heat generation. to be.

In particular, the eddy current loss of the iron core due to the leakage magnetic flux occupies a large proportion, and the iron core generates heat by this eddy current, thereby reducing the efficiency of the equipment. Moreover, it becomes a factor which causes the efficiency reduction of insulation coil wound around this, and insulation reduction. It is also known that the magnitude of the eddy current increases in proportion to the square of the width or the thickness of the magnetic steel sheet in which the magnetic flux enters vertically.

Conventionally, as a substantially circular iron core generally used, there is a hematite core shown in Patent Document 5 (Japanese Patent Laid-Open No. 9-232165). As shown in Fig. 18, the hematite core is formed by stacking a plurality of magnetic steel sheets to form a plurality of kinds of steel plate blocks 200 having different width dimensions, and overlapping the steel plate blocks 200 to have a substantially circular shape. It is formed by stacking.

However, there is a problem that the end face 200a of the steel plate block 200 located at both ends of the stacking direction (both up and down in Fig. 18) becomes large, and a large eddy current is generated at this end face 200a. In addition, there is a problem that an eddy current is generated in the external exposed portion 200b of the laminated surface of each steel plate block 200.

Here, in order to reduce the eddy current, the number of stacks of magnetic steel sheets in each steel plate block 200 is simply reduced, and the types of steel plate blocks 200 having different width dimensions are increased to extend the upper and lower ends of the steel plate block 200. It may be considered to reduce the external exposure portion 200b formed on the end face 200a of the steel plate block 200 located and the outer surface of the iron core.

However, if the type of the steel plate block 200 is increased, there is a problem that the manufacturing cost increases or the work becomes complicated.

Moreover, in recent years, what constituted the tubular shape by radially arranging the magnetic sheets of many sheets which form the elongate flat plate shape cut in narrow width is considered. According to this, generation | occurrence | production of the eddy current by leaking magnetic flux through a magnetic steel sheet can be made small, and it becomes possible to reduce the heat generation amount of an iron core.

However, it is extremely cumbersome to arrange the thin magnetic steel plates radially along a certain circumference. Moreover, even if the inner end of each magnetic steel sheet is densely arranged, the space | gap is formed between the outer ends of the adjacent magnetic steel sheets. For this reason, the operation | work which fills the space | gap etc. by inserting another thin magnetic steel plate in the space | gap is necessary.

In addition, in order to eliminate voids at the outer end of the magnetic steel sheet, the inner end of the radially arranged magnetic steel sheet is fixed to the outer circumference of the pipe by welding, and the magnetic steel sheet is bent by pressing the outer end of the magnetic steel sheet while rotating the pipe. Although it can be considered, welding work, pipe rotation work, pressurization work, etc. are required. These operations are extremely difficult when producing large iron cores (for example, 7 m in axial length).

Furthermore, as shown in Patent Document 4 (Japanese Patent Laid-Open No. 2000-311777) and Patent Document 6 (Japanese Patent Application Laid-Open Model No. 2532986) and the like, a plurality of magnetic steel plates having curved portions having a cross section in a width direction are curved. The applicant has considered a cylindrical iron core formed by stacking in the width direction alternately.

However, the idea is to stack the magnetic steel sheets in a cylindrical shape in any cylindrical iron core, and specifically focuses on how to stack the magnetic steel sheets, that is, in terms of the thickness of the magnetic steel sheets and the lamination side of the magnetic steel sheets. The relationship with the width direction length of an external exposure part is not paid attention.

Thus, the present invention has been made in view of the relationship between the plate thickness of the magnetic steel sheet and the widthwise length of the external exposure portion at the side of the lamination side of the magnetic steel sheet, and was made for the first time to solve the above problems. In order to reduce costs, the main desired problem is to suppress the eddy current caused by the leakage magnetic flux generated in the magnetic steel sheet as much as possible.

That is, the cylindrical iron core according to the present invention is a cylindrical iron core formed by stacking a plurality of magnetic steel sheets having a curved portion whose cross section in a width direction forms a curved shape in the width direction, and an externally exposed portion at the side of the laminated side of the magnetic steel sheet. The width direction length is less than the plate thickness of the magnetic steel sheet.

In this case, when the width direction length of the externally exposed portion is set to s in the cylindrical iron core and the plate thickness of the magnetic steel sheet is set to t, s≤t and the width of the portion where the eddy current occurs is maximum. Since the thickness is the same as that of the magnetic steel sheet, the maximum eddy current value can be made as small as possible. Therefore, by stacking the magnetic steel sheets alternately, a simple configuration and a reduction in manufacturing cost can be realized, and the deterioration of magnetic properties of cylindrical iron cores such as iron loss caused by the generation of eddy currents can be prevented. It is possible to prevent deterioration of the device and heat generation such as deterioration of characteristics and insulation characteristics.

As a specific embodiment for making width direction length s of an external exposure part into the plate | board thickness t of the said magnetic steel plate, inner diameter Φ _A of the said cylindrical iron core, outer diameter Φ _B, and plate | board thickness t of the said magnetic steel sheet,

(Where α is the angle of inclination with respect to the radial direction of the inner circle of the cylindrical iron core, and θ 'is the center angle between the innermost edge of the adjacent magnetic steel sheet and the center of the circle. The unit of the trigonometric function is Radians (rad).), Wherein the inclination angle α of the magnetic steel sheet when the center angle θ 'becomes equal to the center angle θ ₀ when the inclination angle of the magnetic steel sheet is zero is θ _X , When the inclination angle α is less than or equal to θ _X ,

When the inclination angle α of the magnetic steel sheet is larger than θ _X , the center angle θ 'satisfying the above Equation 1 is used.

To make a relationship.

The ratio (Φ _A / Φ _B ) of the inner diameter Φ _A of the cylindrical iron core to the outer diameter Φ _B of the cylindrical iron core for making the widthwise length s of the outer exposed portion s equal to or less than the plate thickness t of the magnetic steel sheet is 0.71 or more. to be.

In addition, it is preferable to use the cylindrical iron core of the present invention in the induction heating roller device, and in particular, the magnetic flux generating mechanism comprising the induction heating roller device wound around the outer circumferential surface of the cylindrical iron core and mounted thereon, and the magnetic flux generation. The apparatus includes a hollow cylindrical heating roll body accommodating the mechanism and rotatably installed relative to the magnetic flux generating mechanism and generating heat by an induced current generated by the magnetic flux of the magnetic flux generating mechanism. It is preferable to interpose a nonmagnetic material or a space of a predetermined interval between the heating roll body. Here, a nonmagnetic substance is a substance which does not show magnetic property like aluminum, and includes ceramics, glass, etc. In addition, the space | gap of a predetermined space | interval is a space | gap with a space | interval which makes only the effective surface length part of a heat generating roll body generate | occur | produces heat, and other parts are hard to generate | occur | produce, and may be a vacuum or air | atmosphere.

As such, by interposing a nonmagnetic material or a gap of a predetermined interval between the cylindrical iron core and the heating roll body, the magnetic resistance is increased to make the magnetic flux difficult to pass, so that only the effective surface length portion of the heating roll body generates heat. A part (for example, the journal part connected to the heat generating body) makes it difficult to generate heat.

At this time, by providing a nonmagnetic material or a predetermined gap between the cylindrical iron core and the heating roll body, the magnetic flux of the leaked magnetic flux penetrating radially from the outer peripheral surface of the cylindrical iron core to be discharged to the outside increases. . However, by using the cylindrical iron core of the present invention, eddy current loss due to leakage magnetic flux, that is, iron loss is suppressed, and self-heating of the magnetic flux generating mechanism itself is prevented.

It is also preferable to use the cylindrical iron core of the present invention in a stationary induction apparatus. In particular, it is preferable that a rectangular iron core configured using a cylindrical iron core is provided, and a nonmagnetic material is provided on at least one of both axial ends of the cylindrical iron core. For example, when it is used for a reactor among stationary induction apparatuses, the magnetoresistance in the magnetic path can be increased, and a predetermined reactance can be obtained. In addition, by increasing the magnetoresistance, the amount of magnetic flux of the leaked magnetic flux penetrating in the radial direction from the outer peripheral surface of each iron core to the outside is increased, but the occurrence of eddy current is suppressed as much as possible by using the cylindrical iron core of the present invention. can do.

Thus, according to the present invention, it is possible to reduce the maximum eddy current value due to the leakage magnetic flux generated in the magnetic steel sheet as much as possible, while also reducing the manufacturing cost of the simple structure, and thus the magnetic characteristics of the iron core and the induction coil generated by the eddy current generation. Deterioration of electrical and insulating properties can be solved.

Next, the induction heating roller device using the cylindrical iron core of the second embodiment will be described with reference to the drawings. In addition, it demonstrates using the code different from the said 1st Embodiment.

<Device Configuration>

The induction heating roller device 1 according to the present embodiment is, for example, in a continuous heat treatment step of a sheet member or a web member such as a resin film, paper, cloth, nonwoven fabric, metal foil, or a hot drawing treatment step of synthetic fibers. It is provided with the hollow cylindrical heating roll body 2 rotatably provided, and the magnetic flux generating mechanism 3 accommodated in this heating roll body 2 is provided.

The journals 4 are attached to both ends of the heat generating body 2. This journal 4 is comprised integrally with the hollow drive shaft 5, and the drive shaft 5 is rotatably supported by the base 7 via the bearing 6, such as rolling bearing.

The magnetic flux generating mechanism 3 is composed of a cylindrical iron core 31 having a cylindrical shape, and an induction coil 32 wound around the outer peripheral surface of the cylindrical iron core 31. Support rods 8 are attached to both ends of the cylindrical iron core 31, respectively. The support rods 8 are inserted into the drive shafts 5, respectively, and are rotatably supported with respect to the drive shafts 5 through bearings 9 such as rolling bearings. Thereby, the magnetic flux generating mechanism 3 is supported in the state suspended in the air inside the heat generating roll body 2. As shown in FIG. A lead wire 10 is connected to the induction coil 32, and an AC power supply (not shown) for applying an AC voltage is connected to the lead wire 10.

Further, a gap or a nonmagnetic material (not shown) at a predetermined interval is provided between the cylindrical iron core 31 and the heating roll body 2 or the journal 4. Specifically, as shown in FIG. 12, the gap G at a predetermined interval is provided between both ends of the cylindrical iron core 31 and the iron core side surface 4a of the journal 4. By providing the space G as described above, the magnetic resistance is increased to make the magnetic flux difficult to pass, so that only the heat generating roll body 2 generates heat, and the journal 4 or the like hardly generates heat.

However, as shown in FIG. 13, the cylindrical iron core 31 of this embodiment is formed in cylindrical shape by stacking several magnetic steel plates 311 shift | deviating in the width direction.

The magnetic steel plate 311 has a long shape, and as shown in FIG. 14, the magnetic steel plate 311 has a curved portion 3111 having a curved cross section in a curved shape. The magnetic steel sheet 311 is formed of, for example, a silicon steel sheet having an insulating coating applied to its surface, and the sheet thickness thereof is, for example, about 0.3 mm.

The curved portion 3111 is considered to be curved at a constant curvature or to be curved while the curvature is continuously changed. For example, an involute shape using a part of an involute curve, a partial arc shape, or a partial elliptical shape, etc. May be considered.

And each magnetic steel plate 311 shifts in the width direction so that the convex part formed by the curved part 3111 of the other magnetic steel plate 311 may be inserted into the recessed part formed by the curved part 3111 of the magnetic steel plate 311. To this end, a plurality of magnetic steel plates 311 forming the same shape are superimposed. At this time, the widthwise end portions 311a and 311b of the magnetic steel sheet 311 are in contact with the concave side 311m or the convex side 311n of the adjacent magnetic steel sheet 311. In this way, a cylindrical iron core 31 forming a cylindrical shape is formed.

Moreover, as shown in the partial enlarged view of FIG. 13, the cylindrical iron core 31 has the width direction length s of the external exposure part 311x in the lamination side side of the magnetic steel plate 311, The board of the magnetic steel plate 311 The magnetic steel plates 311 are laminated so as to have a thickness t or less. That is, when the plate | board thickness t of the magnetic steel plate 311 is 0.3 mm, the width direction length s of the external exposure part 311x shall be 0.3 mm or less.

The laminated side surface of the magnetic steel sheet 311 is the convex side surface 311n of the curved portion 3111 among the side surfaces 311m and 311n facing the adjacent magnetic steel sheet 311. The outer exposed portion 311x is a surface formed outside the widthwise outer diameter side end portion 311b of the magnetic steel plate 311 in contact with the laminated side surface.

Moreover, as shown in FIG. 14, the inclination angle of the center line of the width direction inner diameter side edge part 311a of the magnetic steel plate 311 is inclined with respect to the radial direction of the inner circle of a cylindrical iron core. It is also provided to have a θ _311a. That is, the width direction inner diameter side edge part 311a of the magnetic steel plate 311 is provided so that it may contact a position below the plate thickness dimension toward the outer diameter direction from the width direction inner diameter side edge part 311a of the adjacent magnetic steel plate 311.

In addition, the cylindrical iron core 31 of the present embodiment has an inner diameter Φ _A , an outer diameter Φ _B of the cylindrical iron core 31, and a plate thickness t of the magnetic steel sheet 311.

(Where α is the angle of inclination θ ₃₁₁ with respect to the radial direction of the inner circle of the cylindrical iron core 31, and θ ′ is the center angle formed by the innermost edge of the innermost magnetic steel plate 311 in the radial direction and the center of the circle. Also, the unit of trigonometric function is in radians).

When the center angle θ 'becomes equal to the center angle θ ₀ when the inclination angle θ ₃₁₁ of the magnetic steel plate ₃₁₁ is zero, the inclination angle α (= θ ₃₁₁ ) of the magnetic steel plate ₃₁₁ is θ _X ,

When the inclination angle α of the magnetic steel sheet 311 is θ _X or less,

When the inclination angle α of the magnetic steel sheet 311 is larger than θ _X , the center angle θ 'satisfying the above expression (1) is used.

It is configured to be a relationship.

As shown in Fig. 15, the relational expressions (Expression A) and relational expression (Expression B) are such that the widthwise length s of the external exposed portion 311x and the plate thickness t of the magnetic steel sheet 311 are s ≦ t. The relationship between the inner diameter phi _A and the outer diameter phi _B of the cylindrical iron core 31 is shown. Here, the inner diameter Φ _A of the cylindrical iron core 31 is the diameter of a circle inscribed in the widthwise inner diameter side end portion 311 a of each magnetic steel plate 311, and the outer diameter Φ _B of the cylindrical iron core 31 is each magnetic steel sheet. It is the diameter of the circle | round | yen which circumscribes to the width direction outer diameter side edge part 311b of 311 (refer FIG. 13). In addition, description of the said Formula is abbreviate | omitted similarly to 1st Embodiment.

<Effect of 2nd Embodiment>

According to the induction heating roller device 1 according to the present embodiment configured as described above, the width dimension of the portion of the cylindrical iron core 31 that maximizes the eddy current is equal to or less than the plate thickness t of the magnetic steel plate 311, and the maximum eddy current. The value can be made as small as possible. Therefore, by stacking the magnetic steel plates 311 out of order, the iron loss of the cylindrical iron core 31 can be reduced while realizing a simple configuration and a reduction in manufacturing cost, and as a result, the efficiency of the device can be prevented and heat generation can be prevented. .

In addition, by providing a space between the cylindrical iron core 31 and the heating roll body 2, the magnetic resistance is increased to make the magnetic flux difficult to pass, and only the effective surface length of the heating roll body 2 generates heat. In addition, other parts (for example, the journal 4) make it difficult to generate heat, and at this time, the self-heating of the magnetic flux generating mechanism 3 itself is suppressed by suppressing the eddy current loss, that is, iron loss, against the increasing leakage magnetic flux. Can be prevented. In addition, although the magnetic flux generating mechanism 3 increases in temperature due to heat transfer by the radiation and convection from the heat-generating roll body 2, the heat transfer to portions other than the heat-generating roll body 2 can be reduced by the nonmagnetic material or the gap of a predetermined interval. have.

For example, the cylindrical iron core 31 can also be used for a stationary induction apparatus. 16, the case where it uses for the reactor Z among stationary induction equipment is demonstrated. The reactor Z includes one or more (two in FIG. 16) square iron cores Z1, a coil Z2 wound around the periphery of the square iron cores Z1, and the plurality of square iron cores Z1. ) Is provided with a yoke iron core Z3 which connects the upper and lower ends to each end to form a closed magnetic path. In addition, Z5 in the figure is a fastening bolt for fastening the square iron core (Z1). In addition, one or more gaps are formed in each iron core Z1. Specifically, the iron core Z1 is formed of a plurality of cylindrical iron cores 31. A spacer member Z4 made of an insulator is sandwiched between the cylindrical iron cores 31 in each square core Z1, whereby one or a plurality of gaps are formed in each square core Z1. The spacer member Z4 is also disposed between the yoke core Z3 and the cylindrical iron core 31.

Thereby, the predetermined reactance can be obtained by adjusting the magnetoresistance by the gap. When the magnetic resistance is increased, the leakage magnetic flux increases, but since the widthwise length of the external exposed portion 311x of the magnetic steel sheet 311 is less than or equal to the plate thickness t of the magnetic steel sheet 311, the eddy current increases. If possible, it can be suppressed.

It is also conceivable to use the cylindrical iron core of the above-described embodiment in a stationary induction apparatus connected to an electric circuit using a semiconductor element having a gate circuit. The semiconductor element having the gate circuit acts as an energization switch, but the current flow becomes a current containing a large amount of high frequency components in which the sinusoidal wave shape collapses. For this reason, a large amount of high frequency components are also included in the magnetic flux flowing in the magnetic circuit of the stationary dielectric, and the eddy current loss in proportion to the square of the frequency occurs in the cylindrical iron core. In addition, eddy current loss due to leakage magnetic flux also occurs. At this time, the eddy current loss can be suppressed as much as possible by using a cylindrical iron core.

In addition, although the cylindrical iron core of the said embodiment was one layer in radial direction, especially when using for a reactor or a transformer, it may be a multilayered structure in radial direction.

In addition, in the said embodiment, although the clearance gap of predetermined interval is provided between the cylindrical iron core and the heating roll body, or the journal, a nonmagnetic material may be provided instead of a space | gap. In this case, application to the letterhead induction heating roller device shown in Fig. 17 can be considered. That is, a flange 31f is provided at one end of the cylindrical iron core 31, and the flange 31f is fixed by being screwed to the base 11, for example. In addition, the heating roll body 2 is rotatably supported by the drive shaft 12 inserted through the inside of the cylindrical iron core 31.

In addition, when mentioned above, some or all of embodiment or modified embodiment may be combined suitably, This invention is not limited to the said embodiment, It must be said that various deformation | transformation is possible in the range which does not deviate from the meaning. none.

Industrial availability

According to the present invention, a decrease in magnetic properties of iron cores such as iron loss can be suppressed as much as possible by the improvement of the spot ratio and the reduction of the eddy current.

Claims (7)

An iron core for stationary induction apparatus formed by laminating a plurality of cylindrical iron core elements formed by stacking a plurality of magnetic steel plates having a curved portion having a curved cross section in a width direction in the width direction, in a concentric shape. The method according to claim 1,
A plurality of iron core blocks formed by laminating a plurality of cylindrical iron core elements formed by stacking a plurality of magnetic steel sheets having a curved portion having a curved cross section in a width direction in the width direction, concentrically;
Iron core for stationary induction apparatus having a magnetic gap provided between the iron core block. The method according to claim 2,
An iron core for stationary induction apparatus, wherein the magnetic gap is formed by sandwiching a gap member made of a nonmagnetic material between the iron core blocks. The method according to claim 1,
An iron core for stationary induction apparatus having a width direction length of an external exposed portion at a side of a stacking side of a magnetic steel sheet constituting a cylindrical iron core element provided at the outermost side in the radial direction of the iron core block. The method according to claim 4,
The inner diameter Φ _A , the outer diameter Φ _B and the plate thickness t of the magnetic steel sheet of the cylindrical iron core element provided on the radially outermost side of the iron core block,
[Equation 1]

(Where α is the angle of inclination of the magnetic steel sheet with respect to the radial direction of the inner circle of the cylindrical iron core element, and θ 'is the center angle formed between the innermost edge of the adjacent magnetic steel sheet in the radial direction and the center of the circle. The unit of the function is in radians (rad).
When the center angle θ 'becomes equal to the center angle θ ₀ when the inclination angle of the magnetic steel sheet is zero, the inclination angle α of the magnetic steel sheet is θ _X ,
When the inclination angle α of the magnetic steel sheet is θ _X or less,
[Equation 2]

When the inclination angle α of the magnetic steel sheet is larger than θ _X , the center angle θ 'satisfying the above Equation 1 is used.
[Equation 3]

Iron core for stationary induction equipment forming a relationship of A cylindrical iron core formed by stacking a plurality of magnetic steel sheets having curved portions whose cross sections in a width direction cross each other in the width direction,
The cylindrical iron core whose width direction length of the external exposure part in the laminated side surface of the said magnetic steel sheet is below the plate thickness of the said magnetic steel sheet. The method of claim 6,
The inner diameter Φ _A of the cylindrical iron core, outer diameter Φ _B and the plate thickness t of the magnetic steel sheet,
[Equation 4]

(Where α is the angle of inclination with respect to the radial direction of the inner circle of the cylindrical iron core, and θ 'is the center angle between the innermost edge of the adjacent magnetic steel sheet and the center of the circle. The unit of the trigonometric function is Radians (rad).
When the center angle θ 'becomes equal to the center angle θ ₀ when the inclination angle of the magnetic steel sheet is zero, the inclination angle α of the magnetic steel sheet is θ _X ,
When the inclination angle α of the magnetic steel sheet is θ _X or less,
&Quot; (5) &quot;

When the inclination angle α of the magnetic steel sheet is larger than θ _X , the center angle θ 'satisfying the above Equation 1 is used.
&Quot; (6) &quot;

Cylindrical iron core forming a relationship.

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