JP2760561B2 - Magnetic core - Google Patents

Description

The present invention relates to a magnetic core, and more particularly, to a high output power such as, for example, an induction core of a linear accelerator and a saturable core used for a pulse power supply for a laser. Regarding pulse core.

(Prior Art) Generally, a high-power pulse core, for example, an induction core of a linear accelerator operates essentially as a 1: 1 transformer, and a voltage generated in a secondary gap causes a beam of charged particles passing through the center of the core to be transmitted. It accelerates.

In recent years, a magnetic pulse compressor that operates at a high output and a high voltage has been used in a pulse power supply device for a laser. This pulse compressor is a device that compresses a predetermined pulse having a wide pulse width generated by a power supply and converts the pulse into a pulse having a narrow pulse width but a high output. This conversion operation utilizes the saturation phenomenon of the magnetic core incorporated therein.

Conventionally, as a material of such a core for a high-output pulse, a ferrite-based amorphous alloy ribbon or a cobalt-based amorphous material having properties of high saturation flux density, high squareness ratio of magnetization curve and low iron loss has been used. A magnetic core in which an alloy ribbon and an electric insulating layer made of a polyester film or a polyimide film are alternately laminated or wound is often used.

(Problems to be Solved by the Invention) However, in the case of a magnetic core using a polyester film or a polyimide film as an electric insulating layer, there are the following problems.

That is, when a polyester film is used as the electrical insulating layer, its heat resistance temperature is low (about 200 ° C.), and the high temperature (about 400 ° C.) necessary to improve the magnetic properties of the amorphous alloy is obtained.
° C). As a result, the squareness ratio of the magnetization curve of the magnetic core decreases, and the iron loss increases.

On the other hand, when a polyimide film is used as the electric insulating layer, its heat-resistant temperature is high (about 450 ° C), and heat treatment at a sufficiently high temperature is possible. Since compressive stress is applied to the ribbon, the squareness ratio of the magnetization curve decreases. Furthermore, the fact that the polyimide film is very expensive is also a major industrial problem.

An object of the present invention is to solve the conventional problem by using an aromatic polyamide film as an electric insulating layer, and to provide a magnetic core having a high squareness ratio and low iron loss at low cost.

[Constitution of the Invention] (Means and Action for Solving the Problems) The present invention relates to a magnetic core characterized in that a magnetic ribbon and an electric insulating layer made of an aromatic polyamide film are alternately laminated or wound. is there.

The magnetic ribbon in the present invention is not particularly limited, but is preferably a magnetic ribbon in which an iron-based amorphous alloy, a cobalt-based amorphous alloy, or an iron-based amorphous alloy is crystallized to precipitate fine crystal grains. Among them, as a result of examining the magnetic properties of the magnetic core in a state in which the film is wound in various compositions of the amorphous alloy, the iron-based amorphous alloy has a general formula: Fe
( _100-xy ) Si _x B _y [at%] (7 ≦ x ≦ 11,11 ≦ y
An iron-based amorphous alloy ribbon represented by ≦ 15) has a particularly high squareness ratio.

The cobalt-based amorphous alloy has the general formula:
(Co _1-x F _x ) _100-z (Si _1-Y B _Y ) _z [at%] (0.02
≤ X ≤ 0.08, 0.3 ≤ Y ≤ 0.9, 22 ≤ Z ≤ 18) A particularly low iron loss can be obtained from a cobalt-based amorphous alloy ribbon. In order to further improve the magnetic properties, the general formula for the cobalt-based amorphous alloy described above, Ti, Ta, V, Cr, Mn, Ni, Cu, Mo, Nb,
W can be added up to 8 at%, and Mn, Ni, Mo, and Nb are particularly preferable in consideration of low iron loss.

Such a ribbon can be easily manufactured by applying, for example, a molten metal quenching method to an alloy having a predetermined composition. Although the thickness of the ribbon is not particularly limited, for example, 5
4040 μm, more preferably 15-30 μm.

On the other hand, an aromatic polyamide film (a solution film of para-based wholly aromatic polyamide) used as an electric insulating layer in the present invention causes thermal contraction at a high temperature similarly to a polyimide film, but does not affect the compressive stress applied to the magnetic ribbon. As compared with the case of a polyimide film, it is possible to realize excellent magnetic properties, in particular, a high squareness ratio. This is due to the difference in mechanical and thermal properties at high temperatures between the aromatic polyamide film and the polyimide film.

The thickness of the aromatic polyamide film is not particularly limited, but in consideration of insulating properties, for example, 1.5 to 5
It is preferably 0 μm, more preferably 2 to 25 μm. In addition, in the state where almost no load is applied,
The heat shrinkage when held at 250 ° C. for 10 minutes is preferably 4% or less in both the longitudinal direction and the width direction of the film,
More preferably, it is 2.5% or less.

These magnetic ribbons and magnetic cores can be obtained as follows. That is, heat treatment is performed by alternately laminating or winding a ribbon having a predetermined composition and shape (for example, a thin ribbon punched out or a long ribbon) and an electrically insulating film on a predetermined reel, core, or the like. It is manufactured by In particular, when heat treatment is performed in a DC or AC magnetic field, magnetic characteristics such as the squareness of the obtained magnetic core increase.

If the ribbon is heat-treated in a DC or AC magnetic field prior to the molding of the magnetic core, the squareness ratio of the obtained magnetic core is increased as in the case where the heat treatment is performed on the magnetic core molded body in a magnetic field. In this case, the magnitude of the magnetic field is 0.5 to 100 Oe
About 5 to 20 Oe is more preferable.

When a magnetic core is manufactured from a magnetic ribbon and an electric insulating layer made of an aromatic polyamide film, the core is alternately laminated or wound. However, considering the size of a product or device, a wound core is manufactured. It is more industrially practical to take measures.

Further, the combination of the magnetic ribbon and the electric insulating layer can be appropriately selected depending on the required characteristics. For example, when the electric insulation is strongly required, the electric insulating layer may have two or more layers, and when the magnetic characteristics are important, the magnetic ribbon may have two or more layers.

(Example) Hereinafter, an example of the present invention will be described.

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described.

An amorphous alloy ribbon (thickness: 25 μm) having a composition of Fe ₇₈ Si ₉ B ₁₃ (at%, the same applies to the following Examples and Comparative Examples) and an aromatic polyamide film (a solution of a para-based wholly aromatic polyamide) Film, thickness 6μm) and the outer diameter 50mm,
A wound core having an inner diameter of 30 mm and a height of 13 mm was formed. Next, heat treatment was performed at 380 ° C. and a constant DC constant magnetic field of 10 Oe for 2 hours.

(Comparative Example 1) An amorphous alloy ribbon having a composition of Fe ₇₈ Si ₉ B ₁₃ (thickness 25 μm)
m) and a polyimide film (trade name, Kapton Film, manufactured by DuPont, thickness 7.5 μm) were alternately wound to form a wound core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Next, heat treatment was performed at 380 ° C. and a constant DC constant magnetic field of 10 Oe for 2 hours.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described.

Amorphous alloy ribbon composed of Fe ₇₈ Si ₉ B ₁₃ (thickness 25μ)
m) and an aromatic polyamide film (thickness: 6 μm) with respect to two layers of an amorphous alloy ribbon.
The core was wound in the ratio of layers to form a wound core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Next, heat treatment was performed at 380 ° C. and a constant DC constant magnetic field of 10 Oe for 2 hours.

(Comparative Example 2) An amorphous alloy ribbon having a composition of Fe ₇₈ Si ₉ B ₁₃ (thickness 25 μm)
m) and a polyimide film (thickness: 7.5 μm) were wound at a ratio of two layers of the amorphous alloy ribbon to one layer of the polyimide film to form a wound core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Next, heat treatment was performed at 380 ° C. and a constant DC constant magnetic field of 10 Oe for 2 hours.

In this embodiment, the amorphous alloy ribbon and the polyimide film of the first embodiment are wound alternately at a ratio of one layer of the polyimide film to two layers of the amorphous alloy ribbon. Although the electrical insulation is slightly degraded as compared with that wound, the magnetic properties are improved, and this is very effective for applications that do not require high electrical insulation.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described.

Amorphous alloy ribbon (thickness 17 μm) composed of (Co _0.95 Fe _0.05 ) ₇₅ Si ₁₃ B ₁₂ and aromatic polyamide film (thickness
3.5μm) and the outer diameter is 50mm, inner diameter 30mm, height 1
A 3 mm wound core was formed. Then, heat treatment was carried out at a constant temperature of 390 ° C. and a constant magnetic field of 1 Oe (50 Hz) for 1 hour.

(Comparative Example 3A) An amorphous alloy ribbon (thickness 17 μm) having a composition of (Co _0.95 Fe _0.05 ) ₇₅ Si ₁₃ B ₁₂ and a polyimide film (thickness 7.5 μm)
and m) were alternately wound to form a wound magnetic core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Then, constant temperature of 390 ℃, 1Oe constant magnetic field (5
(0 Hz) for 1 hour.

(Comparative Example 3B) An amorphous alloy ribbon (thickness: 17 μm) having a composition of (Co _0.95 Fe _0.05 ) ₇₅ Si ₁₃ B ₁₂ and a polyester film (trade name,
(Lumira film, manufactured by Toray Industries, thickness 6 μm) was alternately wound to form a wound core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Next, heat treatment was performed at a constant temperature of 170 ° C. and a constant magnetic field of 1 Oe for 3 hours.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described.

An amorphous alloy ribbon (thickness: 15 μm) and an aromatic polyamide film (thickness: 6 μm) having a composition of (Co _0.94 Fe _0.06 ) ₇₀ Ni ₃ Nb ₁ Si ₁₁ B ₁₅ are alternately wound to form an outer diameter of 50 mm and an inner diameter of 50 mm. 30mm,
A winding core having a height of 13 mm was formed. Next, heat treatment was performed for 1 hour at a constant temperature of 400 ° C. and a constant magnetic field of 1 Oe.

Outer diameter turning (Comparative Example 4A) wound composition and _{(Co 0.94 Fe 0.06) 70 Ni} 3 Nb 1 Si 11 amorphous alloy ribbon is B ₁₅ (thickness 15 [mu] m) and a polyimide film (thickness 6 [mu] m) are alternately 50mm, Inner diameter 30mm, Height 13
A wound core of mm was formed. Next, heat treatment was performed for 1 hour at a constant temperature of 400 ° C. and a constant magnetic field of 1 Oe.

Outer diameter turning (Comparative Example 4B) wound composition and _{(Co 0.94 Fe 0.06) 70 Ni} 3 Nb 1 Si 11 amorphous alloy ribbon is B ₁₅ (thickness 15 [mu] m) and a polyester film (thickness 6 [mu] m) are alternately 50mm, inner diameter 30mm, height
A 13 mm wound core was formed. Next, heat treatment was performed at a constant temperature of 170 ° C. and a constant constant magnetic field of 10 Oe for 6 hours.

Embodiment 5 Hereinafter, a fifth embodiment of the present invention will be described.

An amorphous alloy ribbon (thickness: 20 μm) and an aromatic polyamide film (thickness: 6 μm) having a composition of (Co _0.95 Fe _0.05 ) ₇₂ Nb ₁ Si ₁₄ B ₁₃ are alternately wound to form an outer diameter of 50 mm, an inner diameter of 30 mm, height
A 13 mm wound core was formed. Next, after heat treatment at 420 ° C. for 30 minutes, heat treatment was performed for 1 hour at 200 ° C. and a constant Oe DC magnetic field.

Comparative Example 5 An amorphous alloy ribbon (thickness: 20 μm) having a composition of (Co _0.95 Fe _0.05 ) ₇₂ Nb ₁ Si ₁₄ B ₁₃ and a polyimide film (thickness: 6 μm)
and m) were alternately wound to form a wound magnetic core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Next, after heat treatment at 420 ° C. for 30 minutes, heat treatment was performed for 1 hour at 200 ° C. and a constant Oe DC magnetic field.

Embodiment 6 Hereinafter, a sixth embodiment of the present invention will be described.

Amorphous alloy ribbon (thickness: Fe ₇₄ Cu ₁ Nb ₃ Si ₁₅ B ₇₎
20 μm) and an aromatic polyamide film (thickness: 6 μm) were alternately wound to form a wound core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Then, after a heat treatment at a constant temperature of 500 ° C. and a constant DC magnetic field of 10 Oe for 1 hour, fine crystal grains having an average particle diameter of 50 nm or less were precipitated in the ribbon.

(Comparative Example 6) An amorphous alloy ribbon having a composition of Fe ₇₄ Cu ₁ Nb ₃ Si ₁₅ B ₇ (thickness
20 μm) and a polyimide film (thickness: 6 μm) were alternately wound to form a wound core having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 13 mm. Then, after a heat treatment at a constant temperature of 500 ° C. and a constant DC magnetic field of 10 Oe for 1 hour, fine crystal grains having an average particle diameter of 50 nm or less were precipitated in the ribbon.

As described above, the squareness ratio of the magnetization curve and the iron loss of the 14 magnetic cores were measured at a constant temperature based on the following specifications.

Squareness ratio (Br / Bs): Measured with a DC automatic magnetic recorder at an applied magnetic field of 10 Oe.

Iron loss (W / cm ³ ): The iron loss per unit volume of the magnetic material was measured by a U function meter under a sine wave excitation condition of 100 kHz and 2 kG.

 The above results are summarized in Table 1.

As is clear from Table 1, if the magnetic ribbons are the same, the magnetic core using an aromatic polyamide film for the electric insulating layer according to the present invention is different from the magnetic core using a polyimide film or polyester film for the conventional electric insulating layer. compared,
The squareness ratio increases, and the iron loss decreases.

[Effects of the Invention] As described above in detail, according to the present invention, it is possible to provide not only a magnetic core having a high squareness ratio and a low iron loss than a conventional magnetic core, but also an aromatic polyamide film However, the lowering of the production cost due to the lower production cost due to the extremely low cost than the polyimide film is very significant industrially.

Thereby, the present invention can be used for various magnetic cores. Among them, the characteristics of high saturation magnetic flux density, high squareness of the magnetization curve and low iron loss can be effectively utilized, so that it is suitable for a high output pulse core.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiyuki Yamauchi 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Yokohama Office Co., Ltd. (56) References JP-A-55-68601 (JP, A) (58) Investigated Field (Int.Cl. ⁶ , DB name) H01F 3/00-3/04 H01F 27/24-27/25 H01F 41/02

Claims (1)

(57) [Claims] 1. A magnetic core, wherein a magnetic ribbon comprising one or more layers and an electric insulating layer comprising an aromatic polyamide comprising one or more layers are alternately laminated or wound.