TWI450285B - Cylindrical core, static induction device, and induction heating roller apparatus - Google Patents

Description

Cylindrical core, static induction device and induction heating roller device

The present invention relates to a circular core (cylindrical core), an induction heating device such as a static induction device such as a transformer or a reactor, and an induction heating roller device.

In the static induction device such as a transformer or a reactor, the loss of the core of the magnetic circuit becomes a cause of low efficiency and heat generation, and the reduction is a major problem. In particular, the core eddy current loss caused by the leakage flux occupies a large ratio, which causes the core to generate heat and reduces the efficiency of the device. Further, it is a factor that causes the efficiency of the induction coil wound thereon to be lowered and the insulation to be lowered. Further, it is known that the magnitude of the eddy current increases in proportion to the square of the width or thickness of the magnetic steel sheet into which the magnetic flux vertically enters.

In this static induction device, in order to shorten the length of the coil wire wound around the core, the core may be formed in a cylindrical shape. In this case, the core of the static induction device has a flat magnetic steel sheet of different widths and is formed into a cylindrical product core (refer to Patent Document 1), and a flat magnetic steel sheet is laminated and rolled up to form a cylinder. A rolled core (refer to Patent Document 2) and a radially laminated flat magnetic steel sheet form a cylindrical radial core (refer to Patent Document 3). In addition, in such a core, in order to set an appropriate magnetic flux density and obtain a desired reactance, a magnetic gap may be provided between the cores (refer to Patent Document 2).

However, in the product core shown in Patent Document 1, in order to approximate a perfect circle, it is necessary to increase the types of magnetic steel sheets having different width dimensions, which causes problems such as high manufacturing cost and complicated assembly work. Further, in the case where the magnetic gap is provided, the leakage magnetic flux which is discharged to the outside in the radial direction in the core in the vicinity of the gap increases, and an eddy current due to the leakage of the magnetic flux is generated, which causes a problem that the iron core generates heat.

Further, in the wound core shown in Patent Document 2, the structure is such that the entire flat portion of the steel sheet provided on the outermost circumference is exposed, and the maximum value of the eddy current generated from the leakage magnetic flux penetration is large, and the iron loss is increased. Also, in the case where a magnetic gap is provided, this problem becomes remarkable.

Further, in the radial core shown in Patent Document 3, the leakage magnetic flux passes through the end surface of the steel plate, so that the eddy current can be reduced and the heat generation amount of the iron core can be reduced, but the radial arrangement is small along the fixed circumference. The operation of the width magnetic steel plate is extremely troublesome. Further, even if the inner ends of the respective magnetic steel sheets are closely arranged, a gap is formed between the outer ends of the adjacent magnetic steel sheets. Therefore, in order to raise the core ratio of the core upward, it is necessary to insert another small-width magnetic steel sheet or the like into the gap to fill the gap.

Therefore, the applicant of the present invention has considered a cylindrical core, although not used for a stationary induction device, but as a core for an induction heating device called an induction heating roller device, as shown in Patent Document 4, by having a width direction A small-width magnetic steel sheet having a curved portion having a curved shape is formed by staggering stacking in a wide direction. Thereby, the eddy current generated from the leakage magnetic flux penetrating the magnetic steel sheet can be reduced, and the heat generation amount of the iron core can be reduced.

Since the cylindrical core overlaps the small-width magnetic steel sheet, there is a problem that the effective cross-sectional area of the magnetic circuit is small. From the viewpoint of increasing the occupation ratio upward, it is conceivable to simply increase the width dimension of the magnetic steel sheet. However, if the width is simply increased, there is a problem that the use is limited because the outer diameter is increased. In addition, in order to reduce the outer diameter, it is considered that the magnetic steel sheet is provided so as to be inclined as much as possible in the radial direction. However, the area of the flat portion where the magnetic steel sheet is exposed to the outside is increased, and eddy current cannot be prevented. The problem.

Patent Document 1: Japan Shikai Show No. 62-30317

Patent Document 2: Japanese Laid-Open Patent Publication No. 2001-237124

Patent Document 3: Japanese Patent Laid-Open No. 5-105546

Patent Document 4: Japanese Laid-Open Patent Publication No. 2000-311777

Patent Document 5: Japanese Patent Laid-Open No. Hei 9-232165

Patent Document 6: Japanese Registered Utility New Case No. 2532986

Here, the present invention has been made to solve the above problems in one place, and it is a main expectation that the core magnetic quality such as iron loss is suppressed as much as possible by raising the occupation ratio and reducing the eddy current upward.

In other words, the core for a static induction device according to the present invention is characterized in that a plurality of magnetic steel sheets having a curved portion having a curved cross section in a wide direction are staggered in the width direction, and a plurality of cylindrical cores are formed. The element stack is formed in a concentric shape.

In the specific embodiment, the cylindrical core element is preferably curved with a fixed curvature in the radial direction of the circular diameter, and is formed by overlapping a plurality of magnetic steel sheets having a width of 1/4 or less of the diameter in the radial direction. In this case, since the magnetic steel sheet is set to have a diameter of 1/4 or less of the diameter, and the cylindrical core element is gradually laminated in the radial direction and is concentric, it can be simply bent by the magnetic steel sheet. Make a circular core with a large cross-sectional area.

According to the present invention, the core block is formed by laminating a plurality of cylindrical core elements on the concentric circles, and the gap can be reduced in the entire cross section of the circular core to increase the occupation ratio and reduce the iron loss.

Further, the core for a static induction device according to the present invention includes a plurality of core blocks, and the core block is stacked in a wide direction by a plurality of magnetic steel sheets having a curved portion having a curved cross section in a wide direction, and is formed. Most of the cylindrical core elements are laminated in a concentric shape; a magnetic gap is provided between the core blocks; and the effect is increased according to the utilization method. In this way, the magnetic reactance in the magnetic circuit can be increased or decreased by the gap member to obtain a desired reactance. In addition, in the case where the magnetic resistance is increased, although the magnetic flux of the leakage magnetic flux extending in the radial direction increases, This leakage magnetic flux passes through the width direction of the approximately equivalent magnetic steel sheet, so that the eddy current can be reduced. Further, by forming a structure in which magnetic gaps are formed between the core blocks formed by stacking the magnetic steel sheets, it is possible to simplify the manufacturing and reduce the manufacturing cost.

Further, in order to simplify the formation of the magnetic gap and to further simplify the assembly of the core for the stationary induction device, it is desirable that the magnetic gap be a gap member formed by sandwiching a non-magnetic body between the core blocks. And formed.

In order to reduce the maximum eddy current value as much as possible, it is desirable that the magnetic steel sheet of the cylindrical core element provided on the outermost side in the radial direction of the core block has a width in the width direction of the outer exposed portion of the laminated side surface. It is less than or equal to the plate thickness of the aforementioned magnetic steel sheet.

In order to make the length direction s of the outer exposed portion smaller than or equal to the thickness t of the magnetic steel sheet, the specific embodiment is a cylindrical core element provided on the outermost side in the radial direction of the core block, and the inner diameter thereof. Φ _A , outer diameter Φ _B and the thickness t of the aforementioned magnetic steel sheet are:

t cosα-Φ _A sin θ'-(Φ _A + t sinα-Φ _A cos θ') tan(θ'-α) = 0 (calculus 1)

(In this case, the α-type magnetic steel sheet is inclined at an angle with respect to the radial direction of the inner circle of the cylindrical core element, and θ' is a central angle formed between the corner of the innermost end in the radial direction of the adjacent magnetic steel sheet and the center of the circle. The unit of the trigonometric function is radians. In which, when the central angle θ' is equal to the central angle θ ₀ when the inclination angle of the magnetic steel sheet is _zero , the inclination angle α of the magnetic steel sheet at this time is determined as θ _X , and in the case where the inclination angle α of the magnetic steel sheet is less than or equal to θ _X , then:

In the case where the inclination angle α of the magnetic steel sheet is larger than θ _X , the central angle θ′ satisfying the above (Formula 1) is used and becomes:

Relationship.

According to the present invention, by increasing the occupation ratio and reducing the eddy current, it is possible to suppress the magnetic loss of the core such as the iron loss as much as possible.

(Best form of implementing the invention) <First embodiment>

Next, an embodiment of a core 1 for a stationary induction device according to the present invention will be described with reference to the drawings. 1 is a perspective view showing a schematic configuration of a core 1 for a stationary induction device according to the present embodiment, and FIG. 2 is a plan view of a core 1 of a stationary induction device.

The core 1 for a stationary induction device according to the present embodiment is, for example, a circular core for a reactor or a transformer. As shown in Fig. 1, the core 1 includes a plurality of core blocks 2X and a magnetic gap G provided between the core blocks 2X. .

As shown in FIG. 2, the core block 2X is formed by laminating a plurality of cylindrical core elements 2A, 2B, and 2C (three in the present embodiment) in a concentric shape in the radial direction. In the radial direction, the adjacent cylindrical core elements 2A, 2B, and 2C are brought into contact with each other. That is, the outer diameter of one of the adjacent cylindrical core elements 2A, 2B, and 2C is approximately the same as the inner diameter of the adjacent cylindrical core elements 2A, 2B, and 2C. Specifically, in the three cylindrical core elements 2A, 2B, and 2C, the core element provided on the inner diameter side is defined as the first core element 2A, and the core element provided in the middle is defined as the second core element 2B, and When the core element on the outer diameter side is the third core element 2C, for example, the outer diameter of the first core element 2A and the inner diameter of the second core element 2B are approximately the same. Further, an insulating layer (not shown) is provided between each of the cylindrical core elements 2A, 2B, and 2C.

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

The magnetic steel sheet 21 is formed into a long shape, and as shown in FIG. 3, the curved portion 211 having a curved cross section in the wide direction is provided. The magnetic steel sheet 21 is formed of, for example, a ruthenium steel sheet having an insulating film on its surface, and has a plate thickness of, for example, about 0.3 mm.

The curved portion 211 is considered to be curved with a fixed curvature over the entire range, or bent under a continuous curvature change. For example, it is conceivable to use a part of an involute shape, a partial arc shape, or a partial elliptical shape. .

Further, in the concave portion formed by the curved portion 211 of the magnetic steel sheet 21, the convex portion formed by the curved portion 211 of the other magnetic steel sheet 21 is fitted, and the magnetic steel sheets 21 are shifted in the width direction to overlap the plurality of sheets. The magnetic steel sheet 21 has the same shape. At this time, the wide end portions 21a and 21b of the magnetic steel sheet 21 are in contact with the concave side surface or the convex side surface of the adjacent magnetic steel sheet 21. In this way, the cylindrical core elements 2A, 2B, and 2C which are formed into a cylindrical shape are formed.

The magnetic gap G is formed by sandwiching a gap member made of a non-magnetic material so that the core block 2X is sandwiched between the core blocks 2X so as to be coaxial. The gap member is formed of a non-magnetic material such as aluminum, ceramics, or glass, and may be a flat plate or a columnar one. In the present embodiment, the core block 2X has an annular shape having the same shape in the upper view.

Next, a method of manufacturing the core 1 for a stationary induction device according to the present embodiment will be described.

In preparation, a cylindrical member or a cylindrical member (hereinafter referred to as a cylindrical member or the like) having an outer diameter is provided, and the inner circumferential side end portion 21a of the magnetic steel sheet 21 is abutted on the outer circumferential surface thereof while being along the outer side. The circumferential faces are successively overlapped to form the first core element 2A. Then, the first core element 2A is straightened and annealed, and then fixed and insulated by a varnish or an insulator. Then, the outer circumferential side end portion 21a of the magnetic steel sheet 21 is abutted on the outer peripheral surface of the first core element 2A to which the fixing and insulating treatment is applied, and the outer peripheral side of the first core element 2A is successively arranged. The second core element 2B is superposed and formed. When the shape is maintained, the first core element 2A and the columnar member are pulled out from the second core element 2B, and the second core element 2B is straightened and annealed, and then the first core element 2A is again inserted into the second core. In the element 2B, the second core element 2B is laminated along the outer peripheral surface of the first core element 2A. Then, the fixing and the insulating treatment are applied by a varnish, an insulator or the like to form a two-layer core formed by the first core element 2A and the second core element 2B. In the case where the plurality of layers are formed, the above-described steps can be repeatedly performed on the outer peripheral surface of the second core element 2B to form the core block 2X having an arbitrary number of layers. Between the core blocks 2X thus formed, a gap member is interposed, and the core blocks 2X are superposed and fixed so as to be coaxial, whereby the core 1 for stationary induction equipment is formed.

The iron core 1 of the static induction device is arranged such that the magnetic steel sheets 21 constituting the material are arranged in a radial manner, and even if the coil is wound around the outer circumference of the core 1 of the static induction device, no short-circuit current is generated, and The leakage magnetic flux passes through the width direction of the inside of the magnetic steel sheet 21 together with the radial core, and does not pass through the thickness direction in the magnetic steel sheet. Thereby, generation of eddy current caused by leakage magnetic flux can be suppressed. Moreover, since the cross section of the core is approximately a perfect circle, the length of the wound coil wire can be further shortened, and resource saving can be achieved.

In addition, as shown in a partially enlarged view of FIG. 4, the core 1 for a stationary induction device of the present embodiment is provided in a cylindrical core element (third core element) 2C which is the outermost side in the radial direction of the core block 2X, and is configured as The magnetic steel sheet 21 is laminated so that the length s in the width direction of the outer exposed portion 21x of the laminated side surface of the magnetic steel sheet 21 is less than or equal to the thickness t of the magnetic steel sheet 21. In other words, when the thickness of the magnetic steel sheet 21 is 0.3 mm, the length s in the width direction of the outer exposed portion 21x is made 0.3 mm or less.

The side faces 21m and 21n of the magnetic steel sheet 21 face the adjacent magnetic steel sheets, and the laminated side surface of the magnetic steel sheets 21 is the convex side surface 21n of the curved portion 211. In the laminated side surface, the surface which is formed further outward than the width direction outer diameter side end portion 21b of the magnetic steel sheet 21 which is in contact with each other is the outer exposed portion 21x.

In the width direction inner diameter side end portion 21a of the magnetic steel sheet 21, as shown in Fig. 3, the inclination of the center line of the width direction inner diameter side end portion 21a is assumed to be the inner diameter of the third core element 2C. Tilt angle θ _21a . In other words, the width direction inner diameter side end portion 21a of the magnetic steel sheet 21 is oriented from the width direction inner diameter side end portion 21a of the adjacent magnetic steel sheet 21 toward the outer diameter direction, and is in contact with the sheet thickness t or less. .

Further, in the third core element 2C of the present embodiment, the inner diameter Φ _A and the outer diameter Φ _{B of} the third core element 2C and the thickness t of the magnetic steel sheet 21 are:

t cosα-Φ _A sin θ'-(Φ _A + t sinα-Φ _A cos θ') tan(θ'-α) = 0 (calculus 1)

(In this case, the α-type magnetic steel sheet 21 is inclined by an angle θ _21a with respect to the radial direction of the inner circle of the third core element 2C, and θ' is formed between the corner of the innermost end in the radial direction of the adjacent magnetic steel sheet 21 and the center of the circle. In addition, the unit of the trigonometric function is radians. Among them, when the central angle θ' is equal to the central angle θ ₀ when the inclination angle θ _{21a of the} magnetic steel sheet 21 is zero, the magnetic force at this time is The inclination angle α (= θ _21a ) of the steel sheet 21 is set to θ _X , and when the inclination angle α of the magnetic steel sheet 21 is θx or less, then:

When the inclination angle α of the magnetic steel sheet 21 is larger than θ _X , the central angle θ′ satisfying the above (Formula 1) is used, and it is:

The relationship is so constituted.

As shown in FIG. 4, the relational expression (Equation 2) and the relational expression (Equation 3) show the length s of the outer exposed portion 21 _X and the thickness t of the magnetic steel sheet 21 such that s ≦ t holds, and the third The relationship between the inner diameter Φ _A and the outer diameter Φ _{B of the} core element 2C. Here, the inner diameter Φ _A of the third core element 2C is inscribed in a circle having a diameter in the width direction inner diameter side end portion 21a of each of the magnetic steel sheets 21, and the outer diameter Φ _B of the third core element 2C is externally connected to each magnetic The diameter of the circle of the outer diameter side end portion 21b of the steel sheet 21 in the width direction (refer to Fig. 2).

The width direction inner end side end portion 21a of the magnetic steel sheet 21 is perpendicular to the inner diameter Φ _{A of} the third core element 2C for the sake of simplicity (the inclination angle θ _21a of the center line of the width direction inner diameter side end portion _21a is zero (θ _21a) ○), the explanatory diagram is shown in Fig. 5. At this time, the straight line connecting the corner of the inner diameter side end portion 21a and the center line O of the magnetic steel sheet 21 to the center line of the magnetic steel sheet 21 is regarded as a straight line. If the angle formed between θ ₀ /2 (rad), the next relation will hold.

Tan(θ ₀ /2)=( t /2)/(Φ _A /2)= t /Φ _A (Expression 4)

The central angle of the magnetic steel sheet 21 is θ ₀ , and the number of the magnetic steel sheets 21 of the third core element 2C having the inner diameter Φ _A is N ₀ , and the inner diameter side end portions 21 a of the magnetic steel sheets 21 in the width direction are mutually When the contact is tightly arranged without gaps, it becomes:

N ₀ = 2π / θ ₀ ...... (Equation 5)

Further, as shown in FIG. 6, when the length s in the width direction of the outer exposed portion 21x is equal to the thickness t, the distance between the vertex a and the vertex c of the outer end portion 21b of the magnetic steel sheet 21 in the width direction is approximately At Φ _B π/N ₀ . Here, the isosceles right triangle abc becomes:

(Φ _B π/ N ₀ ) ² = 2 t ² ...... (Equation 6)

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

{Φ _B π/(2π/θ ₀ )} ² =2 t ²

If you simplify the two sides of the equal sign, it becomes:

In addition, when the deformation equation θ ₀ /2=tan ⁻¹ (t/Φ _A ) of (Expression 4) is substituted in (Equation 7), an equality expression is obtained in the above relational expression (Formula 2).

Next, considering the case where the inclination angle θ _21a is zero (θ _21a =0), the condition that s < t is established can be considered.

At this time, in the right triangle abc becomes:

(Φ _B π/ N _O ) ² = s ² + t ² <2 t ² ...... (Equation 8)

Here, if (Expression 5) is substituted into (Equation 8), it becomes:

In addition, when the deformation equation θ ₀ /2=tan ⁻¹ (t/Φ _A ) of (Expression 4) is substituted in (Equation 9), an inequality is obtained in the above relationship (Equation 2).

Further, in the case where the inclination angle θ _21a is 0 < θ _21a < θ _{X ,} a condition that s = t can be established.

Here, the angle θ _{X will be} first described. This angle θ _X system: the angle [theta] formed between the innermost end of the radial angle of 0 and the center of the adjacent magnetic steel plates 21 of _'0 is equal to the central angle [theta] of the magnetic plate 21 is inclined an angle θ _21a and is:

t cosα-Φ _A sin θ'-(Φ _A + t sinα-Φ _A cos θ') tan(θ'-α) = 0 (calculus 1)

The central angle θ' is equal to the inclination angle of the magnetic steel sheet 21 at the central angle θ ₀ . This θ _X in the magnetic steel sheet 21 of the inclination angle θ _21a is 0 <θ _21a <angle θ _X in the case where the central angle [theta] is smaller than θ _0. 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 central angle θ ₀ . The other (calculation 1) and the derivation of θ _x are explained at the end.

When the number of laminated sheets of the magnetic steel sheets 21 is N', N'>N ₀ is an angle formed between the angle of the innermost end in the radial direction of the adjacent magnetic steel sheets 21 and the center O as shown in Fig. 7 . ', then θ'< θ ₀ .

As a result, it becomes:

(Φ _B π/ N ') ² = 2 t ² ...... (Equation 10)

N '=2π/θ'... (Equation 11)

By (Equation 10) and (Formula 11):

{Φ _B π/(2π/θ')} ² =2 t ²

If you simplify both sides, it becomes:

This (Equation 12) becomes:

That is, the inclination angle θ _{21a of the} magnetic steel sheet 21 satisfies the range of the outer diameter Φ _B in which s = t holds in the range of 0 < θ _21a < θ _X , and includes the inclination angle θ _{21a of} the magnetic steel sheet 21 at θ _21a = In the case of 0, the range of the outer diameter Φ _B where s = t is satisfied is satisfied. Therefore, when the inner diameter Φ _A , the outer diameter Φ _{B ,} and the plate thickness t satisfy the inequality of the above relation (Expression 2), even if the inclination angle θ _21a of the magnetic steel sheet 21 is in the range of 0 < θ _{21 a} < θ _X Internal time can also make s = t.

Next, considering a case where the inclination angle θ _21a is 0 < θ _21a < θ _X, a condition that s < t can be established.

At this time, in the right triangle abc becomes:

(Φ _B / N ') ² = s ² + t ² <2 t ² ...... (Equation 13)

If (Equation 11) is substituted into (Equation 13), it becomes:

This (Equation 14) becomes:

That is, the inclination angle θ _{21a of the} magnetic steel sheet 21 satisfies the range of the outer diameter Φ _{B where} s < t holds in the range of 0 < θ _21a < θ _X , and includes the inclination angle θ _{21a of} the magnetic steel sheet 21 at θ _21a = In the case of 0, the range of the outer diameter Φ _B where s < t can be established. Therefore, in the case where the inner diameter Φ _A , the outer diameter Φ _{B ,} and the plate thickness t satisfy the inequality of the above relation (Equation 2), the inclination angle θ _{21a of the} magnetic steel sheet 21 is within the range of 0 < θ _{21 a} < θ _X In the case of s<t, it is also possible.

Next, considering the case where the inclination angle θ _21a is θ _21a = θ _{X ,} a condition in which s = t and s < t can be satisfied. At this time, since θ _X = θ ₀ , the condition that s = t and s < t can be made the same when θ _21a =0.

Next, considering a case where the inclination angle θ _{21a is} larger than θ _X (θ _21a > θ _X ), a condition that s = t can be established.

In this case, when the magnetic steel sheet 21 of the stack as the number N ', then N'<N _0, 7, is formed between the adjacent magnetic steel plates 21 in the radial direction of the innermost end of the corner and the center O If the angle is θ', then θ'>θ ₀ . Moreover, if the distance between the vertex A and the vertex A' is the assumed thickness t', then:

Tan(θ'/2)=( t '/2)/(Φ _A /2)= t '/Φ _A

Therefore, θ'=2tan ^-1 ( t '/Φ _A ) (Expression 15)

Also, become:

(Φ _B π/ N ') ² = 2 t ² ...... (Equation 16)

N '=2π/θ'... (Equation 17)

According to (Equation 16) and (Equation 17):

{Φ _B π/(2π/θ')} ² =2 t ²

By simplifying the sides of the equal sign, it becomes:

If (Equation 18) is substituted into (Equation 15), it becomes:

Here, the cosine theorem is used in the triangle OAA':

( t ') ² =(Φ _A ) ² +(Φ _A ) ² -2(Φ _A ) ² cosθ', and becomes:

Then, if (Equation 20) is substituted in (Equation 19), the equality expression in the above relational expression (Equation 3) is obtained.

Next, considering the case where the inclination angle θ _{21a is} larger than θ _X (θ _21a > θ _X ), it is considered that s < t is satisfied.

At this time, in the right triangle abc becomes:

(Φ _B π/ N ') ² = s ² + t ² <2 t ² (Expression 21)

If (Expression 17) is substituted into (Equation 21), it becomes:

In addition, when (Expression 15) and (Equation 20) are carried in (Equation 22), the inequality in the above relational expression (Equation 3) is obtained.

According to the above, by selecting the inner diameter Φ _A , the outer diameter Φ _B , and the thickness t of the third core element 2C satisfying the above relational expression, the third core element 2C in which s ≦t is established can be produced.

In a specific example, in the case where 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 core element 2C is set to 550 (mm), and the outer diameter Φ _{B is} set to 600 (mm). When the thickness t of the magnetic steel sheet 21 is set to 0.3 (mm), it becomes: outer diameter . Therefore, in the condition that the inclination angle α of the magnetic steel sheet 21 is θ _X or less, the magnetic steel sheet 21 having a thickness t of 0.3 (mm) is used to produce an inner diameter Φ _A 550 (mm) and an outer diameter Φ _B 600 (mm). In the case of the third core element 2C, the length s in the width direction of the outer exposed portion 21 _X of the third core element 2C can be made smaller than the thickness t.

In the case where 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 core element 2C is set to 550 (mm), and the outer diameter Φ _{B is} set to 600 (mm), and the magnetic steel sheet 21 is set. The plate thickness t is set to 0.3 (mm), and when the assumed plate thickness t obtained from the above (Formula 1) is 0.35 (mm), it becomes: . 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 thickness t of 0.3 (mm) is used to produce an inner diameter Φ _A 550 (mm) and an outer diameter Φ _B 600 (mm). In the case of the core element 2C, the length s in the width direction of the outer exposed portion 21x of the third core element 2C can be made smaller than the thickness t.

Furthermore, in order to show the relationship between the inner diameter Φ _A and the outer diameter Φ _B in the case where s=t is made, the simulation result is shown in FIG. Figure 8 shows the outer diameter Φ _B fixed at 60, and the inner diameter Φ _A when the coefficient a is changed in the involute (x = a (cos θ + θsin θ), y = a (sin θ - θ cos θ)) relationship. In addition, the θ system in which s=t is established: 1.25π, 3.25π, 5.25π.

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 of s=t can be made: Φ _A /Φ _B >42.6/60=0.71.

Further, in order to show the relationship between the inner diameter Φ _A and the outer diameter Φ _B when 2s=t is made, the simulation result is shown in FIG. 9 is the same as FIG. 8 described above, showing that the outer diameter Φ _{B is} fixed at 60, and the coefficient a is changed in the involute (x=a(cosθ+θsinθ), y=a(sinθ-θcosθ)). When the relationship is the inner diameter Φ _A . In addition, the θ system in which 2s=t is established: 1.25π, 3.15π, 5.15π.

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 x 2). That is, the inner diameter/outer diameter of 2s=t can be made: Φ _A /Φ _B >53.7/60=0.895. Thus, from the simulation results, it is considered that the ratio of the inner diameter/outer diameter at which s≦t can be established must be: Φ _A / Φ _B > 0.71.

Finally, the derivation of the angle θ _X is explained with reference to FIG. First, the geometric information is described mathematically.

The plane L ₁ passing through the point A (R (= Φ _A /2), 0) of the first magnetic steel sheet shown in Fig. 10 is:

L ₁ :f(x,y)=0

Further, the plane L ₂ of the second magnetic steel sheet adjacent to the first magnetic steel sheet can be expressed by using the rotation angle θ' of the center:

L2: g(f(x, y), θ')=0

This plane L _{2 is in} contact with the first magnetic steel sheet at point B (x _b , y _b ), and thus the following formula holds:

g(f(x _b ,y _b ),θ')=0

Hereinafter, it is assumed that the cross-sectional shapes of the planes L ₁ and L ₂ are straight lines. If the angle formed between L ₁ and the x axis is α, then geometrically the function f becomes the following formula:

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

Further, if the thickness of the steel sheet is t, the coordinates of the point B become (R + tsin α, tcos α). If the coordinate value of this point B is substituted into the formula L ₂ , it becomes:

tcosα-Rsinθ-(R+tsinα-Rcosθ)tan(θ-α)=0

According to this equation, when the inner diameter R (= Φ _A /2) and the thickness t are provided, α obtained by θ' = θ ₀ becomes θ _X .

<Effect of the first embodiment>

According to the core 1 for a stationary induction device of the present embodiment, the core block 2X is formed by a plurality of laminated cylindrical core elements 2A, 2B, and 2C on a concentric circle, and can increase the occupancy rate upward and can Reduce iron loss. Further, the magnetic resistance in the magnetic path can be increased or decreased by the gap member G to obtain a desired reactance, and in addition, when the magnetic resistance is increased, the magnetic flux of the leakage magnetic flux extending in the radial direction increases. The leakage magnetic flux passes through the width direction of the approximately equivalent magnetic steel sheet, so that the eddy current can be reduced. In addition, by arranging the gap member G between the core blocks 2X formed by staggering the stacked magnetic steel sheets 21, it is possible to simplify the manufacturing and reduce the manufacturing cost.

<Other variant embodiment>

Further, the present invention is not limited to the above embodiment. In the following description, members corresponding to the above-described embodiments are denoted by the same reference numerals.

For example, in the above embodiment, the stacking direction of each of the cylindrical core elements is the same, but the cylindrical core elements may be stacked in opposite directions.

Further, in the above embodiment, the core block is composed of three cylindrical core elements, but may be composed of two cylindrical core elements or four or more cylindrical core elements. In other words, the core of the static induction device may be composed of two or more cylindrical core elements in accordance with the use thereof.

Further, in the above-described embodiment, the magnetic steel sheet 21 is composed only of the curved portion 211, but as shown in Fig. 11, the curved portion 211 may be connected to the width direction of the curved portion 211. The bent portion 212 formed at the end of the radial side is formed. At this time, the bending angle θ of the bent portion 212 with respect to the curved portion 211 is preferably, for example, 30 degrees, and the shorter the length, the better, and it is desirable to be, for example, about 3 to 10 times the thickness of the magnetic steel sheet 21. When the bending portion 212 is included, the work of stacking the magnetic steel sheets 21 can be easily performed, and the magnetic steel sheets 21 can be appropriately prevented from falling off in the radial direction.

<Second embodiment>

Next, a second embodiment of a cylindrical core, an induction heating roller device, and a stationary induction device capable of appropriately suppressing eddy currents will be described.

In a static induction device called a transformer or a reactor, or an electromagnetic induction device such as an induction heating device called an induction heating roller device, the loss of the core that becomes a magnetic circuit becomes a cause of low efficiency and heat generation of the electromagnetic induction device. Lowering the system is a big problem.

In particular, the eddy current loss of the core caused by the leakage flux occupies a large ratio, and this eddy current will cause the core to generate heat, which will make the efficiency of the device low. Moreover, this is a factor that causes the efficiency of the induction coil wound around it to be low and the insulation to be low. Further, it is known that the magnitude of the eddy current increases in proportion to the width of the magnetic steel sheet or the square of the plate thickness into which the magnetic flux vertically enters.

For example, the product is shown in Japanese Patent Laid-Open No. Hei 9-232165. As shown in Fig. 18, the product core is formed by laminating a plurality of sheets of magnetic steel sheets to form a plurality of steel sheet pieces 200 of different widths, and the steel sheet pieces 200 are formed into a substantially circular shape by stacking.

However, the end faces 200a of the steel sheet blocks 200 located at both ends in the lamination direction (upper and lower ends in Fig. 18) become larger, and there is a problem that a large eddy current is generated in the end faces 200a. Further, even the outer exposed portion 200b of the laminated surface of each of the steel sheets 200 has a problem of generating an eddy current.

Here, in order to reduce the eddy current, it is conceivable to reduce the number of laminated steel sheets in each steel sheet block 200, and to increase the type of the steel sheet block 200 of different width dimensions, and to reduce the number of the steel sheet blocks 200 at the upper and lower ends of the steel sheet block 200. The end surface 200a of the steel block 200 and the outer exposed portion 200b formed on the outer peripheral surface of the core.

However, if the type of the steel sheet block 200 is increased, there will be problems such as an increase in manufacturing cost or a complicated work.

Further, recently, a plurality of sheet-shaped magnetic steel sheets having a long flat shape cut into a small width are considered to be radially arranged and formed into a tubular shape. In this way, the generation of eddy current caused by the leakage magnetic flux penetrating through the magnetic steel plate can be reduced, and the heat generation amount of the iron core can be reduced.

However, it is extremely troublesome to arrange the magnetic steel sheets having a small width in a radial shape along a fixed circumference. Further, even if the inner ends of the respective magnetic steel sheets are closely arranged, a gap is formed between the outer ends of the adjacent magnetic steel sheets. Therefore, it is necessary to insert another small-width magnetic steel sheet or the like into the gap to fill the gap.

Further, in order to eliminate the void at the outer end of the magnetic steel sheet, it is conceivable to fix the inner end of the radially arranged magnetic steel sheet to the outer circumference of the duct by welding, and to press the outer end of the magnetic steel sheet while rotating the duct to bend the magnetic steel sheet. However, it is necessary to perform a welding operation, a pipe rotation operation, and a pressurization operation. These operations are extremely difficult when manufacturing large cores (for example, the axial length is 7 m).

In addition, as shown in the patent document 4 (JP-A-2000-311777) and the patent document 6 (Japanese registered utility model No. 2532986), the applicant of the present invention has considered a cylindrical core by having a wide-direction section. A plurality of magnetic steel sheets that become curved portions of a curved shape are stacked in a wide direction to form a stack

However, in any of the cylindrical cores, the idea of stacking the magnetic steel sheets into a cylindrical shape is only required. Specifically, only the magnetic steel sheets are stacked, that is, they are not focused on: the thickness of the magnetic steel sheets, and The relationship between the length in the width direction of the outer exposed portion on the side surface of the laminated side of the magnetic steel sheet.

Therefore, the present invention is the first to focus on the relationship between the thickness of the magnetic steel sheet and the length in the width direction of the outer exposed portion on the side surface of the laminated side of the magnetic steel sheet, and to achieve the above problem in a simple manner. It is a main desired problem to construct and reduce the manufacturing cost while suppressing the eddy current caused by the leakage magnetic flux generated in the magnetic steel sheet as much as possible.

In other words, the cylindrical core of the present invention is formed by stacking a plurality of magnetic steel sheets having a curved portion having a curved cross section in a wide direction in the width direction, and is characterized by being external to the side surface side of the magnetic steel sheet lamination. The length in the width direction of the exposed portion is equal to or less than the thickness of the magnetic steel sheet.

In this case, when the length of the outer exposed portion is set to s and the thickness of the magnetic steel sheet is set to t in the cylindrical core, s≦t is established, and the width of the eddy current generating portion is maximized. It is also only equal to the thickness of the magnetic steel plate, so that the maximum eddy current value can be made as small as possible. Therefore, it is possible to realize a simple configuration by staggering the stacked magnetic steel sheets, reduce the manufacturing cost, and prevent the magnetic properties of the cylindrical core such as iron loss caused by the eddy current from being lowered, and further, the electrical characteristics of the induction coil can be prevented. Low efficiency and heat generation of equipment such as low insulation characteristics.

In order to make the length direction s of the outer exposed portion smaller than or equal to the thickness t of the magnetic steel sheet, in a specific embodiment, the inner diameter Φ _A , the outer diameter Φ _{B of the} cylindrical core, and the magnetic steel sheet are The thickness t is:

t cosα-Φ _A sinθ'-(Φ _A + t sinα-Φ _A cosθ')tan(θ'-α)=0

(here, the angle of inclination of α in the radial direction with respect to the inner circle of the cylindrical core, and θ' is the central angle formed between the angle of the innermost end in the radial direction of the adjacent magnetic steel sheet and the center of the circle. The unit of the function is radians. In which, when the central angle θ' is equal to the central angle θ ₀ when the inclination angle of the magnetic steel sheet is _zero , the inclination angle α of the magnetic steel sheet at this time is set to θ _{X .} And in the case where the inclination angle α of the magnetic steel sheet is less than or equal to θ _X , then:

In the case where the inclination angle α of the magnetic steel sheet is larger than θ _X , the central angle θ′ satisfying the above (Formula 1) is used and becomes:

Relationship.

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

Further, the cylindrical core of the present invention is desirably used for an induction heating roller device, and it is particularly desirable that the induction heating roller device includes a magnetic flux generating mechanism that is formed by winding an induction coil on the outer circumferential surface of the cylindrical core, and a heating rotating body. The hollow magnetic cylinder is provided with the magnetic flux generating mechanism, and is rotatable with respect to the magnetic flux generating mechanism, and generates heat by an induced current generated by the magnetic flux of the magnetic flux generating mechanism; A gap between the core and the heat generating rotating body is separated by a non-magnetic material or a gap. Here, the non-magnetic material is a material which does not exhibit magnetism such as aluminum, and also includes ceramics or glass. Further, the gap in which the gap is set is a gap which allows the heat generating rotating body to generate heat only at the effective face length, and which is less likely to generate heat in other portions, and may be vacuum or air.

In this manner, the magnetic flux is hardly passed by increasing the magnetic resistance between the cylindrical core and the heating rotating body via the non-magnetic material or the gap of the set gap, so that the heating rotating body has only the effective surface length portion. It is hot, and other parts (such as the journal portion connected to the heating rotating body) are hard to generate heat.

In this case, since a non-magnetic material or a gap having a predetermined gap is provided between the cylindrical core and the heat generating rotating body, the magnetic flux of the leakage magnetic flux which is transmitted from the outer peripheral surface of the cylindrical core to the outside in the radial direction and discharged to the outside is provided. increase. However, by using the cylindrical core of the present invention, eddy current loss caused by leakage magnetic flux, that is, iron loss, is suppressed, and self-heating of the magnetic flux generating mechanism itself is prevented.

Furthermore, the cylindrical core of the present invention is desirably used for a stationary induction device. In particular, it is preferable to include a foot core formed using a cylindrical core, and a non-magnetic body is provided on at least one of both end portions of the cylindrical core in the axial direction. For example, when used in a reactor in a stationary induction device, the magnetic resistance in the magnetic circuit can be increased to obtain a set reactance. Further, the increase in the magnetic resistance increases the magnetic flux of the leakage magnetic flux which penetrates the radial direction from the outer peripheral surface of the foot core and is discharged to the outside, but is suppressed as much as possible by using the cylindrical core of the present invention. Eddy current is generated.

According to the present invention as described above, it is possible to achieve a simple configuration and to reduce the manufacturing cost, and at the same time suppress the maximum eddy current value caused by the leakage magnetic flux generated in the magnetic steel sheet as much as possible, thereby solving the magnetic properties of the iron core caused by the eddy current generation. The electrical characteristics and insulation properties of the induction coil are low.

Next, an induction heating roll device using the cylindrical core of the second embodiment will be described with reference to the drawings. In the description, component symbols different from those in the first embodiment are used.

<Device configuration>

The induction heating roller device 100 according to the present embodiment is used for a continuous heat treatment step of a sheet or a mesh material such as a resin film, paper, cloth, nonwoven fabric, metal foil, or the like, or a thermal stretching treatment step of a synthetic material. Further, the heating rotating body 2 is provided in a hollow cylindrical shape and is rotatably provided, and the magnetic flux generating mechanism 3 is housed in the heating rotating body 2.

A journal 4 is attached to both end portions of the heating rotor 2 . The journal 4 is integrally formed with the hollow drive shaft 5, and the drive shaft 5 is rotatably supported by the base 7 by a bearing 6 such as a rolling bearing.

The magnetic flux generating mechanism 3 is composed of a cylindrical core 31 having a cylindrical shape and an induction coil 32 wound around the outer peripheral surface of the cylindrical core 31. Support rods 8 are attached to both ends of the cylindrical core 31. This support rod 8 is inserted through the inside of each drive shaft 5, and is supported by a bearing 9 such as a rolling bearing to be freely rotatable with respect to the drive shaft 5. Thereby, the magnetic flux generating mechanism 3 is supported in a suspended state inside the heat generating rotating body 2. The induction coil 32 is connected to a wire 10 to which an alternating current power source (not shown) for applying an alternating voltage is connected.

Further, a gap or a non-magnetic body (not shown) at a predetermined interval is provided between the cylindrical core 31 and the heating rotor 2 or the journal 4. Specifically, as shown in FIG. 12, a gap G at a predetermined interval is provided between both ends of the cylindrical core 31 and the core side surface 4a of the journal 4. By providing the gap G in this manner, the magnetic resistance is increased and the magnetic flux is hard to pass, and only the heat generating rotating body 2 is heated, and the journal 4 or the like is hard to generate heat.

Therefore, as shown in FIG. 13, the cylindrical core 31 of the present embodiment is formed in a cylindrical shape by stacking a plurality of magnetic steel sheets 311 in the width direction.

The magnetic steel sheet 311 has a long shape, and as shown in FIG. 14, it has a curved portion 3111 having a curved cross section in a wide direction. The magnetic steel sheet 311 is formed of, for example, a ruthenium steel sheet having an insulating film on its surface, and has a plate thickness of, for example, about 0.3 mm.

The curved portion 3111 is considered to be bent with a fixed curvature over the entire range, or curved under a continuous curvature change, for example, an involute shape, a partial arc shape, or a partial elliptical shape using a part of the involute Wait.

Further, in the concave portion formed by the curved portion 3111 of the magnetic steel sheet 311, the convex portion formed by the curved portion 3111 of the other magnetic steel sheet 311 is fitted, and the magnetic steel sheets 311 are shifted in the width direction to overlap the plurality of sheets. The magnetic steel sheet 311 has the same shape. At this time, the wide end portions 311a and 311b of the magnetic steel sheet 311 are in contact with the concave side surface 311m or the convex side surface 311n of the adjacent magnetic steel sheet 311. The cylindrical core 31 having a cylindrical shape is formed in this manner.

As shown in a partial enlarged view of FIG. 13, the cylindrical core 31 has a length s in the width direction of the outer exposed portion 311x on the side surface of the laminated side of the magnetic steel sheet 311, which is equal to or smaller than the thickness t of the magnetic steel sheet 311. Layer magnetic steel plate 311. In other words, when the thickness t of the magnetic steel sheet 311 is 0.3 mm, the length s in the width direction of the outer exposed portion 311x is 0.3 mm or less.

The side faces 311m and 311n face the adjacent magnetic steel sheets 311, and the laminated side surface of the magnetic steel sheets 311 is the convex side surface 311n of the curved portion 3111. In the laminated side surface, the surface which is formed further outward than the width direction outer diameter side end portion 311b of the magnetic steel sheet 311 which is in contact with each other is the outer exposed portion 311x.

In the width direction inner diameter side end portion 311a of the magnetic steel sheet 311, as shown in Fig. 14, the inclination of the center line of the inner side end portion 311a in the width direction is inclined in the radial direction of the inner circumference of the cylindrical core. Angle θ _311a . In other words, the width direction inner diameter side end portion 311a of the magnetic steel sheet 311 is oriented from the width direction inner diameter side end portion 311a of the adjacent magnetic steel sheet 311 toward the outer diameter direction, and is in contact with a sheet thickness or less. .

Further, in the cylindrical core 31 of the present embodiment, the inner diameter Φ _A , the outer diameter Φ _{B of} the cylindrical core 31, and the thickness t of the magnetic steel plate 311 are:

t cosα-Φ _A sinθ'-(Φ _A + t sinα-Φ _A cosθ')tan(θ'-α)=0

(In this case, the angle α of the α-system in the radial direction of the inner circle of the cylindrical core is θ ₃₁₁ , and θ′ is the central angle formed between the angle of the innermost end in the radial direction of the adjacent magnetic steel sheet 311 and the center of the circle. The unit of the trigonometric function is radians. Among them, when the central angle θ' is equal to the central angle θ ₀ when the inclination angle θ _{311 of the} magnetic steel plate ₃₁₁ is zero, the inclination angle of the magnetic steel plate 311 at this time is obtained. α(=θ ₃₁₁ ) is set to θ _X , and in the case where the inclination angle α of the magnetic steel plate 311 is θ _X or less, then:

In the case where the inclination angle α of the magnetic steel sheet 311 is larger than θ _X , the central angle θ′ satisfying the above (Formula 1) is used and becomes:

Relationship.

As shown in FIG. 15, the relationship (Formula A) and the relational expression (Formula B) show a cylindrical shape in which the length s of the outer exposed portion 311x and the thickness t of the magnetic steel plate 311 are such that s≦t is established. The relationship between the inner diameter Φ _A and the outer diameter Φ _B of the core 31. Here, the inner diameter Φ _A of the cylindrical core 31 is a diameter of a circle which is inscribed in the width direction inner diameter side end portion 311a of each of the magnetic steel sheets 311, and the outer diameter Φ _B of the cylindrical core 31 is externally connected to each magnetic The diameter of the rounded outer diameter side end portion 311b of the steel plate 311 is wide (refer to Fig. 13). The description of the above formula is the same as that of the first embodiment, and is omitted.

<Effects of Second Embodiment>

According to the induction heating roller device 100 of the present embodiment, the eddy current is the largest portion of the cylindrical core 31, and the width dimension thereof is equal to or smaller than the thickness t of the magnetic steel plate 311, so that the maximum vortex can be reduced as much as possible. Current value. Therefore, a simple structure can be realized by staggering the stacked magnetic steel sheets 311, and the manufacturing cost can be reduced, and the iron loss of the cylindrical core 31 can be reduced, and as a result, the efficiency of the apparatus can be prevented from being lowered and the heat can be prevented.

Further, by providing a gap between the cylindrical core 31 and the heat generating rotating body 2, the magnetic resistance is increased and the magnetic flux is hard to pass, and not only the effective surface length portion of the heat generating rotating body 2 is heated but also other portions ( For example, the journal 4) is difficult to generate heat, and at this time, eddy current loss, that is, iron loss, can be suppressed with respect to the increased leakage magnetic flux, and self-heating of the magnetic flux generating mechanism 3 itself can be prevented. Further, although the heat transfer by the radiation from the heating rotor 2 and the convection heats up the magnetic flux generating mechanism 3, the portion other than the heat generating rotating body 2 can be reduced by the non-magnetic material or the gap of the set gap. The heat passed.

Further, for example, the cylindrical core 31 can also be used for a stationary induction device. The case of the reactor Z used in the stationary induction device will be described using FIG. The reactor Z includes: 1 or a plurality of (two in FIG. 16) foot cores Z1, a coil Z2 wound around the outer circumference of the foot core Z1, and a top and bottom connected to each of the plurality of foot cores Z1. Each end portion forms a yoke core Z3 that closes the magnetic circuit. In addition, Z5 is used to fasten the fastening bolts of the foot core Z1. Then, one or a plurality of gaps are formed in each of the foot cores Z1. Specifically, the foot core Z1 is formed by a plurality of cylindrical cores 31. In each of the foot cores Z1, a spacer member Z4 made of an insulator is interposed between the cylindrical cores 31, whereby one or a plurality of gaps are formed in the foot core Z1. Further, a spacer member Z4 is also disposed between the yoke core Z3 and the cylindrical core 31.

Therefore, the gap can be adjusted by the gap to obtain a set reactance. Further, although the leakage magnetic flux is increased in the case where the magnetic resistance is increased, the length of the outer exposed portion 311x of the magnetic steel plate 311 is less than or equal to the thickness t of the magnetic steel plate 311, so that the vortex is suppressed as much as possible. The increase in current.

Further, it is also conceivable to use the cylindrical core of the above embodiment for a stationary induction device in which a stationary induction device is connected to a circuit using a semiconductor element including a gate circuit. The semiconductor element including the gate circuit functions as a power-on switch, but the current that passes through becomes a current including a large number of harmonic components that collapse the sinusoidal shape. Therefore, the magnetic flux flowing in the magnetic circuit of the static induction device also contains a large amount of high-order harmonic components, and in the cylindrical core, eddy current loss proportional to the square of the frequency is generated. In addition, eddy current losses caused by leakage flux will also occur. At this time, the eddy current loss can be suppressed as much as possible by using the cylindrical core.

Further, although the cylindrical core of the above-described embodiment has a single layer in the radial direction, it may have a multilayer structure in the radial direction, particularly in the case of a reactor or a transformer.

Further, in the above embodiment, a gap is set between the cylindrical core and the heat generating rotating body or the journal, but a non-magnetic material may be provided instead of the gap. At this time, it is considered to be applicable to the cantilever type induction heating roller device shown in FIG. That is, a flange 31f is provided at one end of the cylindrical core 31, and the base 11 is fixed to the flange 31f by, for example, screw fastening. Further, the heating rotor 2 is rotatably supported by a drive shaft 12 inserted through the inside of the cylindrical core 31.

In addition, some or all of the above-described embodiments and modified embodiments may be combined as appropriate, and the present invention is not limited to the embodiments described above, and various modifications may be made without departing from the spirit and scope of the invention.

(industrial use)

According to the present invention, the magnetic deterioration of the iron core such as the iron loss can be suppressed as much as possible by the upward increase of the occupation ratio and the reduction of the eddy current.

1. . . Iron core for stationary sensing equipment

2. . . Heating rotating body

2X. . . Iron core block

2A, 2B, 2C. . . Cylindrical core element

3. . . Magnetic flux generating mechanism

4. . . Journal

4a. . . side

5. . . Drive shaft

6. . . Bearing

7. . . Abutment

8. . . Support rod

9. . . Bearing

10. . . wire

11. . . Abutment

12. . . Drive shaft

twenty one. . . Magnetic steel plate

21a, 21b. . . Ends

21m, 21n. . . side

21x. . . External exposure

31. . . Cylindrical core

31f. . . Flange

32. . . Induction coil

100. . . Induction heating roller device

200. . . Steel block

200a. . . End face

200b. . . External exposed part (external exposed part)

211. . . Bending

212. . . Flexion

311. . . Magnetic steel plate

311a, 311b. . . Ends

311m, 311n. . . side

311x. . . External exposure

3111. . . Bending

A, A’. . . vertex

B. . . point

a, b, c. . . vertex

G. . . Magnetic gap (gap member, gap)

s. . . Width length

t. . . Plate thickness

L ₁ , L ₂ . . . flat

N ₀ , N'. . . Number of sheets (number of sheets)

O. . . Center of mind

Z. . . Reactor

Z1. . . Foot core

Z2. . . Coil

Z3. . . Yoke core

Z4. . . Spacer member

Z5. . . Fastening bolt

α. . . slope

θ, θ ₀ , θ'. . . Center angle

θ _X , θ _21a , θ _311a . . . Center angle

Φ _A . . . the inside diameter of

Φ _B . . . Outer diameter

Fig. 1 is a perspective view of a core for a stationary induction device according to an embodiment of the present invention.

Fig. 2 is a plan view showing a core for a static induction device of the same embodiment.

Fig. 3 is a cross-sectional view showing a magnetic steel sheet of the same embodiment.

Fig. 4 shows the relationship between the thickness of the outer exposed portion and the magnetic steel sheet.

Fig. 5 is an enlarged schematic view showing the end portion of the magnetic steel sheet in the width direction on the inner diameter side (θ _21a =0).

Fig. 6 is a view showing the distance between the outer corners a-c when the length of the outer exposed portion in the width direction and the thickness of the magnetic steel sheet are set to be the same.

Fig. 7 is an enlarged schematic view showing the end portion of the magnetic steel sheet in the width direction on the inner diameter side (0 < θ _21a ).

Figure 8 shows the simulation results.

Figure 9 shows the simulation results.

Figure 10 is a diagram for explaining the derivation of the angle θ _X .

Fig. 11 is a cross-sectional view showing a modification of the magnetic steel sheet.

Fig. 12 is a schematic view showing the configuration of an induction heating roller device using a cylindrical core according to a second embodiment.

Figure 13 is a cross-sectional view showing a cylindrical core of the same embodiment.

Fig. 14 is a sectional view showing a magnetic steel sheet of the same embodiment.

Fig. 15 shows the relationship between the thickness of the outer exposed portion and the magnetic steel sheet.

Fig. 16 is a schematic view showing a reactor using the cylindrical core of the second embodiment.

Figure 17 is a schematic view of a cantilever type induction heating roller device.

Fig. 18 is a cross-sectional view showing the structure of a conventional product core.

1. . . Iron core for stationary sensing equipment

2X. . . Iron core block

2A, 2B, 2C. . . Cylindrical core element

G. . . Magnetic gap (gap member, gap)

Claims (6)

A core for a static induction device is formed by stacking a plurality of magnetic steel sheets having a curved portion having a curved cross section in a wide direction in a width direction, and laminating a plurality of formed cylindrical core elements into a concentric shape. The inner end portion of the magnetic steel sheet in the width direction is inclined with respect to the diameter direction of the cylindrical core element, and the length of the outer portion of the outer surface of the laminated side of the magnetic steel sheet is smaller than the thickness of the magnetic steel sheet. . The core for a static induction device according to claim 1, wherein the core block includes: a plurality of core blocks which are staggered in a wide direction by a plurality of magnetic steel sheets having a curved portion having a wide cross section and a curved shape, and a plurality of cylindrical core element layers formed are formed in a concentric shape; and a magnetic gap is provided between the core blocks; and a magnetic steel plate constituting a cylindrical core element disposed on the outermost side in the radial direction of the core block The inner end portion of the inner diameter side of the wide-angle direction is inclined in the radial direction of the cylindrical core element, and the magnetic steel sheet of the cylindrical core element provided on the outermost side in the radial direction of the core block is exposed to the outside of the laminated side surface. The length in the width direction is smaller than the thickness of the magnetic steel sheet. The core for a static induction device according to claim 2, wherein the magnetic gap is formed by sandwiching a gap member made of a non-magnetic material between the core blocks. The core for a static induction device according to the first aspect of the invention, wherein the inner diameter Φ _A and the outer diameter Φ _B of the cylindrical core element disposed at the outermost side in the radial direction of the core block, and the thickness of the magnetic steel plate t is: t cos α -Φ _A sin θ '-(Φ _A + t sin α -Φ _A cos θ ')tan( θ '- α )=0 (Expression 1) (here, The angle of inclination of the α-based magnetic steel sheet with respect to the radial direction of the inner circle of the cylindrical core element, θ′ is the central angle formed between the angle between the innermost end in the radial direction of the adjacent magnetic steel sheet and the center of the circle; The unit is radians (rad), wherein when the central angle θ' is equal to the central angle θ _{0 of} the magnetic steel plate at an inclination angle of zero, the inclination angle α of the magnetic steel plate at this time is set to θ _X , and In the case where the inclination angle α of the magnetic steel sheet is equal to or less than θ _X , then: In the case where the inclination angle α of the magnetic steel sheet is larger than θ _X , the central angle θ′ satisfying the (Formula 1) is used and becomes: Relationship. A cylindrical core formed by staggering a plurality of magnetic steel sheets having a curved portion having a curved cross section in a wide direction in a width direction, wherein an inner diameter side end portion of the magnetic steel sheet in the width direction is for the cylindrical iron core The diameter direction of the element is inclined, and the length of the outer exposed portion of the magnetic steel sheet on the side surface of the lamination is less than or equal to the thickness of the magnetic steel sheet. The cylindrical core of claim 5, wherein the inner diameter Φ _A , the outer diameter Φ _{B of} the cylindrical core, and the thickness t of the magnetic steel plate are: t cos α -Φ _A sin θ ' -(Φ _A + t sin α -Φ _A cos θ ') tan( θ '- α ) = 0 (Expression 1) (here, the α-based magnetic steel sheet is opposed to the cylindrical core element The inclination angle of the inner circle in the radial direction, θ' is the central angle formed between the angle of the innermost end in the radial direction of the adjacent magnetic steel plate and the center of the circle; and the unit of the trigonometric function is radians (rad). When the central angle θ' is equal to the central angle θ ₀ when the inclination angle of the magnetic steel sheet is zero, the inclination angle α of the magnetic steel sheet at this time is set to θ _X , and the inclination angle α of the magnetic steel sheet is equal to or less than θ _X . Situation, then: In the case where the inclination angle α of the magnetic steel sheet is larger than θ _X , the central angle θ′ satisfying the (Formula 1) is used and becomes: Relationship.