WO2012132565A1 - 外側コアの製造方法、外側コア、およびリアクトル - Google Patents
外側コアの製造方法、外側コア、およびリアクトル Download PDFInfo
- Publication number
- WO2012132565A1 WO2012132565A1 PCT/JP2012/052942 JP2012052942W WO2012132565A1 WO 2012132565 A1 WO2012132565 A1 WO 2012132565A1 JP 2012052942 W JP2012052942 W JP 2012052942W WO 2012132565 A1 WO2012132565 A1 WO 2012132565A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- outer core
- core
- punch
- soft magnetic
- manufacturing
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/22—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
- H01F1/24—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
- H01F27/255—Magnetic cores made from particles
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F37/00—Fixed inductances not covered by group H01F17/00
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0206—Manufacturing of magnetic cores by mechanical means
- H01F41/0246—Manufacturing of magnetic circuits by moulding or by pressing powder
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
Definitions
- the present invention is manufactured by a manufacturing method of an outer core that manufactures an outer core that is exposed from the coil and constitutes a part of the reactor, and is manufactured by the manufacturing method.
- the present invention relates to an outer core and a reactor including the outer core.
- the present invention relates to a method of manufacturing an outer core effective for reducing reactor loss.
- Hybrid vehicles and the like have a booster circuit in the power supply system to the motor.
- a reactor is used as one component of this booster circuit.
- this reactor there exists a thing shown in patent document 1, for example.
- the reactor of Patent Document 1 includes a coil 105, an inner core 101 c disposed in the coil 105, and an outer core 101 e disposed exposed from the coil 105. More specifically, as shown in FIG. 8, the coil 105 is formed by connecting a pair of coil elements 105a and 105b, in which a winding 105w is spirally wound, in a parallel state.
- the inner core 101c is a columnar body having a rectangular cross section, and is disposed inside each of the coil elements 105a and 105b.
- the outer core 101e is a columnar body that is exposed from the coil 105 and has a substantially trapezoidal (trapezoidal) upper and lower surface, and forms an annular core facing the end surfaces of both inner cores 101c.
- the outer core 101e is formed by using a coated soft magnetic powder comprising a plurality of coated soft magnetic particles obtained by coating a soft magnetic particle with an insulating coating as a raw material powder, and pressing the raw material powder.
- the pressurization is generally performed by filling a molding space formed by a relatively movable columnar first punch and a cylindrical die with a coated soft magnetic powder, Is performed by compressing the coated soft magnetic powder in the molding space.
- the coated soft magnetic powder is compressed so that the first punch and the second punch form the upper and lower surfaces of the outer core. This is because the compacting of the green compact is generally performed by compressing the raw material powder so that the cross section of the compact having a cut surface in the direction orthogonal to the pressing direction is uniform.
- the outer core manufactured as described above has an outer surface surrounded by the die, that is, a surface parallel to the direction to be pressed (a surface perpendicular to the magnetic flux direction).
- the insulating coating of the coated soft magnetic particles may be damaged by sliding contact with the mold when the body is removed.
- the soft magnetic particles may be exposed and spread, and as a result, the soft magnetic particles in the compacted body are electrically connected to each other to form a substantially film-like conductive part, resulting in an eddy current.
- the loss increases and the magnetic properties of the outer core deteriorate.
- the present invention has been made in view of the above circumstances, and one of its purposes is to provide an outer core manufacturing method capable of manufacturing an outer core effective in reducing reactor loss.
- Another object of the present invention is to provide an outer core manufactured by the manufacturing method of the present invention.
- Another object of the present invention is to provide a low-loss reactor.
- the present invention achieves the above-described object by specifying the pressing direction when pressing the outer core, that is, pressing a specific surface of the green compact. Specifically, the coated soft magnetic powder is compressed in a direction in which the cross section of the molded body having a cut surface in a direction orthogonal to the pressing direction is non-uniform.
- the outer core manufacturing method of the present invention is a method of manufacturing an outer core included in the following reactor by pressure molding.
- the reactor includes a coil, an inner core, and an outer core. More specifically, the coil is formed by connecting a pair of coil elements in which windings are spirally wound in parallel with each other. There is a pair of inner cores, which are arranged inside each of the coil elements. A pair of the outer cores are exposed from the coil and are connected to the inner cores to form the inner core and the annular core. In addition, it includes a connection surface with the inner core and an opposing surface facing the other outer core with the inner core interposed therebetween.
- the manufacturing method is a manufacturing method for manufacturing the outer core, and includes a preparation step and a molding step.
- a coated soft magnetic powder comprising a plurality of coated soft magnetic particles in which a soft magnetic particle is coated with an insulating coating is prepared as a raw material powder for the outer core.
- the coating soft magnetic powder is filled in a molding space formed by a relatively movable columnar first punch and a cylindrical die, and is arranged opposite to the first punch and the first punch.
- the coated soft magnetic powder in the molding space is pressure-molded by a columnar second punch. In that case, the said opposing surface in the said outer core is pressurized with the said 2nd punch.
- an outer core that is effective in reducing reactor loss can be manufactured.
- the molding step by pressing the surface to be the facing surface, the surface does not slide in contact with the mold during pressurization or demolding. For this reason, the insulating coating of the coated soft magnetic powder on the facing surface is hardly damaged, and it is difficult to form a conducting portion where the soft magnetic particles are conducted.
- the facing surface includes a connecting surface connected to the inner core, and when the reactor is assembled and the coil is excited, the connecting surface becomes a linkage surface through which the magnetic flux passes substantially orthogonally. That is, since it is difficult for the conductive portion to be formed on the facing surface, eddy current is hardly generated on the surface of the coupling surface, and eddy current loss can be reduced.
- One aspect of the production method of the present invention is characterized in that the soft magnetic particles are pure iron.
- the soft magnetic particles are pure iron, it is possible to produce an outer core that is effective in reducing reactor loss. Since pure iron is soft, it is easily deformed when pressure-molded, and the insulating coating is easily damaged by sliding contact with the mold when the coated soft magnetic powder is pressed or when the molded body is removed. Therefore, the conductive part is easily formed and loss is likely to increase. However, by pressurizing the surface to be the facing surface, it is difficult to form a conduction part on the facing surface, and therefore, an eddy current hardly occurs on the surface of the facing surface. As a result, even if the soft magnetic particles are pure iron, an outer core that can reduce the loss can be manufactured.
- the planar shape of the outer core may be any of the following (A) to (C).
- A) A bow shape in which the opposite side of the outer core to the inner core is a string and the opposite side is an arc.
- B) A trapezoidal shape with the long side of the outer core facing the inner core.
- an outer core that is effective in reducing the reactor loss can be manufactured regardless of the planar shape of the outer core.
- the above-mentioned bow shape includes a substantially bow shape having a string and an arc in addition to an arc shape formed only by a string and an arc. Specifically, a shape in which a part of the arc is cut out in parallel with the string, a shape having a protruding portion that protrudes in the opposite direction from a part of the arc, and the like can be given. The same applies to the trapezoidal shape and U-shape.
- the trapezoidal shape includes a substantially trapezoid having a long side and a short side, in addition to a trapezoid formed by a long side and a short side opposite to the long side.
- the U-shape includes a substantially U-shape having an opening in addition to the U-shape having an opening on the opposite side.
- it includes a shape in which a part on the opposite side of the opening is cut out in parallel with the connecting surface, and a shape having a protruding part that protrudes in the opposite direction from a part on the opposite side.
- Each of the protrusions may have a uniform shape in the opposite direction, or may have a shape in which the width decreases from the opposite side toward the opposite direction.
- a polygonal shape such as a rectangle, a bow shape, a semicircular shape, and the like can be given.
- the planar shape of the outer core may further include at least one of the following (D) and (E).
- E A rectangular surface opposite to the opposing surface, the longer side being a surface parallel to the opposing surface.
- dye, and a surface non-orthogonal and 2nd punch Since a distance corresponding to the thickness of the opposing rectangular surface to be formed is formed between them, the non-orthogonal surface and the second punch can be prevented from colliding with each other, and the die and the second punch can be damaged. Can be prevented.
- a sufficient pressure can be applied to the coated soft magnetic powder, and a high-density outer core can be easily manufactured. Furthermore, it is possible to prevent formation of sharp corners that are easily chipped at both ends in the width direction of the opposing surface of the outer core.
- the thickness of the opposing surface side rectangular surface is from 0.3 mm to 2.0 mm.
- the thickness of the opposing surface side rectangular-shaped surface may be 0.3 mm or more, the surface which is not orthogonal to the pressurization surface of the 2nd punch in the internal peripheral surface of die
- the coated soft magnetic material on the opposing surface side disposed near the coil when the reactor is constructed during pressurization or demolding The area where the powder and the die are in sliding contact can be reduced. Therefore, damage to the insulating coating can be suppressed and eddy current loss can be reduced.
- the opposite rectangular surface when at least the opposite rectangular surface is provided, when the thickness from the opposing surface of the outer core to the opposite surface of the opposing surface is t, the opposite rectangular surface
- the shape surface has a thickness of 0.5 mm or more and t / 2 or less.
- the opposite rectangular surface is manufactured to have a thickness of 0.5 mm or more, the first punch relatively enters the inside of the die (second punch side) during pressurization. It can be prevented sufficiently.
- the thickness of the opposite rectangular surface is set to t / 2 or less, the opposite rectangular surface with respect to the entire outer core does not increase too much.
- the thickness of the said opposing surface side rectangular surface is The thickness is smaller than the thickness of the opposite rectangular surface.
- the outer core effective for reducing the loss of the reactor can be manufactured.
- the outer core of the present invention is manufactured by the outer core manufacturing method of the present invention.
- the outer core of the present invention since eddy currents hardly occur on the surface of the facing surface, it can be suitably used for a reactor. This is because according to the outer core of the present invention, when the reactor is assembled, at least a part of the facing surface where the conducting portion is not formed is connected to the end surface of the inner core, so that a vortex is formed on the surface of the facing surface. This is because current is difficult to generate, which is effective in reducing reactor loss.
- the reactor of the present invention includes a coil, an inner core, and an outer core.
- the coil is formed by connecting a pair of coil elements in which windings are spirally wound in parallel to each other.
- the inner core is disposed inside the coil elements.
- the outer core is exposed from the coil and has a facing surface facing a side facing the inner core to form an annular core with the inner core.
- the outer core is the outer core of the present invention.
- the reactor of the present invention it is possible to achieve a low loss by providing the outer core that is unlikely to generate eddy current on the facing surface facing the inner core.
- the outer core manufacturing method of the present invention can manufacture an outer core that is effective in reducing reactor loss.
- the outer core of the present invention can construct a low-loss reactor.
- the reactor of the present invention can be low loss.
- FIG. 6 is a process explanatory diagram illustrating an example of a procedure in the outer core manufacturing method according to the first embodiment. It is process explanatory drawing which shows the outline of an example of the procedure in the manufacturing method of the outer core which concerns on the modification 1.
- FIG. It is process explanatory drawing which shows the outline of an example of the procedure in the manufacturing method of the outer core which concerns on the modification 2.
- It is process explanatory drawing which shows the outline of an example of the procedure in the manufacturing method of the outer core which concerns on the modification 3.
- It is process explanatory drawing which shows the outline of an example of the procedure in the manufacturing method of the outer core which concerns on the modification 4.
- It is a perspective view which shows the outline of the reactor which concerns on Embodiment 2.
- Embodiment 1 is a method of manufacturing an outer core included in a reactor by pressure molding.
- the reactor includes a coil 105, an inner core 101c, and an outer core 101e as shown in FIG.
- the coil 105 is formed by connecting a pair of coil elements 105a and 105b, in which a winding 105w is spirally wound, in parallel with each other.
- the inner core 101c is arranged inside the coil elements 105a and 105b.
- the outer core 101e is exposed from the coil 105 and connected to each inner core 101c to form the inner core 101c and the annular core 101.
- connection surface with the inner core 101c and an opposing surface that faces the other outer core 101e.
- connection surfaces are a flat surface and is disposed flush with each other.
- opposing surface containing both connection surfaces is also a plane.
- the mold used in the manufacturing method of the present invention typically has a cylindrical die provided with a through hole, and a pair of columnar first punches that can be inserted from the openings of the through hole of the die. And a second punch.
- the pair of first punch and second punch are arranged to face each other in the through hole.
- a bottomed cylindrical molding space is formed by one surface of one punch (the pressure contact surface facing the other punch) and the inner peripheral surface of the die.
- the molding powder is filled with raw material powder, which will be described later, and pressed and compressed with both punches to produce an outer core.
- Each opposing surface of both punches forms each end surface of the outer core, and the inner peripheral surface of the die forms the outer peripheral surface of the outer core.
- the molding die 1 includes, for example, a cylindrical die 10A having a through hole 10b as shown in FIG. 1, and a pair of columnar upper punch 11 and lower punch inserted into and removed from the through hole 10b.
- the thing which comprises 12 is mentioned.
- the die 10 ⁇ / b> A and the lower punch 12 show a longitudinal section.
- the longitudinal sectional shape of the inner periphery of the through hole provided in the die may be a shape corresponding to the shape of the outer core in plan view.
- the other punch side of the die has an inner peripheral shape in which the dimension in the width direction of the die is smaller than the one punch side.
- the inner peripheral shape is not particularly limited as long as it can press the surface of the outer core facing the inner core with one punch.
- the through-hole provided in the die includes a large rectangular hole through which one punch is inserted, a small rectangular hole through which the other punch is inserted, and a large rectangular hole to a small rectangular hole between both rectangular holes.
- the dimension of the width direction becomes small, and it is comprised by the taper hole which neither punch is penetrated. That is, the inner peripheral surface of the large rectangular hole is a parallel region parallel to the side surface of one punch, the inner peripheral surface of the small rectangular hole is a parallel region parallel to the side surface of the other punch, and the inner peripheral surface of the tapered hole. Is a non-parallel region that is not parallel to the side surface of any punch.
- a large rectangular hole 10p (opposing surface side parallel region) through which the upper punch 11 is inserted into the upper punch 11 side of the die 10A and a lower punch 12 side.
- the lower side (lower punch 12) side of the die 10A is more.
- the inner peripheral shape of the tapered hole 10c is that the upper surface 10u side, that is, the lower end of the large rectangular hole 10p is a chord, the lower punch 12 side, that is, the upper end side of the small rectangular hole 10r is an arc, and a part of the arc is formed.
- the lower end of the large rectangular hole 10p refers to the boundary between the large rectangular hole 10p and the tapered hole 10c
- the upper end of the small rectangular hole 10r refers to the boundary between the small rectangular hole 10r and the tapered hole 10c.
- the thickness of the through hole 10b of the die 10A (the vertical direction in the drawing) is uniform in the depth direction (the vertical direction on the drawing) of the through hole 10b. That is, the cross-sectional shapes of the rectangular holes 10p and 10r are uniform in the direction in which the punches 11 and 12 face each other, and the cross-sectional shape of the tapered hole 10c decreases from the large rectangular hole 10p side to the small rectangular hole 10r side. ing.
- the upper punch 11 and the lower punch 12 are columnar bodies that can be inserted into the through holes of the die.
- a lower surface 11d of the upper punch 11 that faces the lower punch 12 has a shape suitable for the space created by the die 10A.
- the shape of the lower surface 11d of the upper punch 11 forms the shape of the surface facing the inner core in the outer core.
- the lower surface 11d of the upper punch 11 is a rectangular plane, and the upper punch 11 is wider than the lower punch 12 (the distance in the left-right direction in FIG. 1).
- a surface corresponding to the upper punch 11 of the molded body press-formed by the upper punch 11 is a rectangular plane.
- Each of the upper punch 11 and the lower punch 12 is an integrally molded product of a quadrangular prism member.
- the pressure contact surface of the upper punch 11 forms an opposing surface of the outer core
- the pressure contact surface of the lower punch 12 forms an end surface opposite to the opposing surface of the outer core
- the constituent material of the molding die 1 includes an appropriate high-strength material (such as high-speed steel) that is conventionally used for molding a green compact (mainly composed of metal powder).
- an appropriate high-strength material such as high-speed steel
- At least one of the pair of punches and the die are relatively movable.
- the lower punch 12 is fixed to a main body device (not shown) and does not move, and the die 10 ⁇ / b> A and the upper punch 11 can be moved in the vertical direction by a moving mechanism (not shown).
- the die 10A can be fixed and the punches 11 and 12 can be moved, and the die 10A and the punches 11 and 12 can be moved.
- the moving mechanism is not complicated, and the moving operation can be easily controlled.
- the green compact can be easily removed.
- a lubricant can be applied to a molding die (in particular, the inner peripheral surface of the die).
- Lubricant is a metal soap such as lithium stearate, a fatty acid amide such as stearic acid amide, a solid lubricant such as higher fatty acid amide such as ethylenebisstearic acid amide, a solid lubricant dispersed in a liquid medium such as water. Examples thereof include liquids and liquid lubricants. However, the smaller the amount of lubricant used (applied thickness), the higher the proportion of the magnetic component is obtained.
- the upper punch 11 and the lower punch 12 are shown as integrally formed, but at least one of the upper punch and the lower punch is composed of a plurality of members. Also good. In that case, it can also be set as the structure which each member can each move independently.
- a coated soft magnetic powder that is a raw material powder for the outer core is prepared.
- the coated soft magnetic powder includes a plurality of coated soft magnetic particles in which an insulating coating is coated on the outer periphery of the soft magnetic particles.
- the soft magnetic particles preferably contain 50% by mass or more of iron.
- Iron alloys such as Fe-Si alloys, Fe-Al alloys, Fe-N alloys, Fe-Ni alloys, Fe-C alloys are preferable.
- An alloy, an Fe—B alloy, an Fe—Co alloy, an Fe—P alloy, an Fe—Ni—Co alloy, and an Fe—Al—Si alloy can be used. Then, eddy current loss can be easily reduced and the loss can be further reduced.
- pure iron in which 99% by mass or more is Fe is preferable.
- the average particle diameter of the soft magnetic particles may be any size that contributes to low loss as a green compact. That is, although it can select suitably, without specifically limiting, For example, if it is 1 micrometer or more and 150 micrometers or less, it is preferable.
- the average particle size of soft magnetic particles By setting the average particle size of soft magnetic particles to 1 ⁇ m or more, the increase in coercive force and hysteresis loss of compacts made using soft magnetic powder is suppressed without reducing the fluidity of soft magnetic powder. it can.
- the average particle size of the soft magnetic particles to 150 ⁇ m or less, eddy current loss that occurs in a high frequency region of 1 kHz or more can be effectively reduced.
- the average particle size of the soft magnetic particles is more preferably 40 ⁇ m or more and 100 ⁇ m or less. If the lower limit of the average particle diameter is 40 ⁇ m or more, an effect of reducing eddy current loss can be obtained, and handling of the coated soft magnetic powder becomes easy, and a molded body having a higher density can be obtained.
- the average particle diameter means a particle diameter of particles in which the sum of masses from particles having a small particle diameter reaches 50% of the total mass in the particle diameter histogram, that is, 50% particle diameter.
- the shape of the soft magnetic particles is preferably such that the aspect ratio is 1.2 to 1.8.
- the aspect ratio is the ratio between the maximum diameter and the minimum diameter of the particles.
- Soft magnetic particles having an aspect ratio in the above range can increase the demagnetizing factor when formed into a compact, compared to those having a small aspect ratio (close to 1.0), and have excellent magnetic properties. It can be set as a molded body. In addition, the strength of the green compact can be improved.
- the soft magnetic particles are preferably produced by an atomizing method such as a water atomizing method or a gas atomizing method. Since the soft magnetic particles produced by the water atomization method have many irregularities on the particle surface, it is easy to obtain a high-strength molded product by meshing the irregularities. On the other hand, the soft magnetic particles produced by the gas atomization method are preferable because the particle shape is almost spherical, and there are few irregularities that break through the insulating coating. A natural oxide film may be formed on the surface of the soft magnetic particles.
- the insulating coating is covered with soft magnetic particles in order to insulate adjacent soft magnetic particles.
- the contact between the soft magnetic particles can be suppressed, and the relative magnetic permeability of the compact can be suppressed.
- the presence of the insulating coating can suppress the eddy current from flowing between the soft magnetic particles, thereby reducing the eddy current loss of the green compact.
- the insulating coating is not particularly limited as long as it has excellent insulating properties that can ensure insulation between soft magnetic particles.
- examples of the material for the insulating film include phosphate, titanate, silicone resin, and two layers of phosphate and silicone resin.
- the insulating coating made of phosphate is excellent in deformability, even when soft magnetic particles are deformed when a soft magnetic material is pressed to produce a compact, a deformation follows the deformation. Can do. Further, the phosphate coating has high adhesion to iron-based soft magnetic particles and is difficult to fall off from the surface of the soft magnetic particles.
- a metal phosphate compound such as iron phosphate, manganese phosphate, zinc phosphate, or calcium phosphate can be used.
- an insulating coating made of a silicone resin it has excellent heat resistance, so that it is difficult to be decomposed in a heat treatment step described later, and the insulation between soft magnetic particles can be maintained well until the compacting body is completed.
- the insulating coating has a two-layer structure of the phosphate and the silicone resin
- the average thickness of the insulating coating may be a thickness that can insulate adjacent soft magnetic particles. For example, it is preferably 10 nm or more and 1 ⁇ m or less. By setting the thickness of the insulating coating to 10 nm or more, it is possible to effectively suppress contact between soft magnetic particles and energy loss due to eddy current. On the other hand, by setting the thickness of the insulating coating to 1 ⁇ m or less, the ratio of the insulating coating to the coated soft magnetic particles does not become too large, and the magnetic flux density of the coated soft magnetic particles can be prevented from significantly decreasing.
- the thickness of the insulating coating can be examined as follows. First, the film composition obtained by composition analysis (TEM-EDX: transmission electron microscope energy dispersive X-ray spectroscopy) and the inductively coupled plasma mass analysis (ICP-MS: inductively coupled plasma amount) are obtained. Considering this, a considerable thickness is derived. Then, the film is directly observed with a TEM photograph, and the average thickness determined by confirming that the order of the equivalent thickness derived earlier is an appropriate value is used.
- composition analysis TEM-EDX: transmission electron microscope energy dispersive X-ray spectroscopy
- ICP-MS inductively coupled plasma amount
- the method for coating the soft magnetic particles with the insulating coating may be appropriately selected.
- the film may be formed by hydrolysis / polycondensation reaction.
- Soft magnetic particles and a material constituting the insulating coating are blended, and the blend is mixed in a heated state. By doing so, the soft magnetic particles can be sufficiently dispersed in the coating material, and the insulating coating can be coated on the outside of the individual soft magnetic particles.
- the above heating temperature and mixing time may be appropriately selected.
- the soft magnetic particles can be more sufficiently dispersed, and it becomes easy to coat the individual particles with the insulating coating.
- the coated soft magnetic powder is pressure-molded using the molding die 1 described above.
- a coating space 31 made of the lower punch 12 and the cylindrical die 10A in the mold 1 is filled with the coated soft magnetic powder, which is the raw material powder P of the outer core, and the upper punch 11, the lower punch 12, Thus, the coated soft magnetic powder in the molding space 31 is pressure-molded.
- the upper punch 11 is moved to a predetermined standby position above the through hole 10b in the die 10A. Further, the die 10A is moved upward, and a predetermined molding space 31 is formed by the upper surface 12u of the lower punch 12 and the through hole 10b of the die 10A. At that time, in the next pressurizing step, the lower punch 12 may be arranged in consideration of the distance by which the die 10A descends when pressurizing.
- the upper surface 12u of the lower punch 12 is positioned in the small rectangular hole 10r of the die 10A so as to be positioned on the lower opening side of the die 10A from the upper end of the small rectangular hole 10r by an amount corresponding to the downward movement of the die 10A during pressurization.
- the lower punch 12 is disposed.
- the above-mentioned coated soft magnetic powder is prepared as a raw material powder. Then, as shown in FIG. 1 (B), the prepared raw material powder P is filled into a forming space 31 formed by the die 10A and the lower punch 12 by a powder feeding device (not shown).
- the pressure to be applied can be selected as appropriate, but for example, if a green compact to be used as a reactor core is manufactured, it is preferably about 490 to 1470 MPa, particularly about 588 to 1079 MPa. By setting it to 490 MPa or more, the raw material powder P can be sufficiently compressed, the relative density of the outer core can be increased, and by setting it to 1470 MPa or less, damage to the insulating coating due to contact between the coated soft magnetic particles constituting the raw material powder P Can be suppressed.
- the die 10A When the pressurization is completed, the die 10A is lowered, and when the pressurization is completed, the position of the upper surface 12u of the lower punch 12 is positioned at the upper end of the small rectangular hole 10r of the die 10A.
- the die 10A After performing the predetermined pressurization, the die 10A is moved relative to the molded body 41 as shown in FIG. Here, the molded body 41 is not moved, and only the die 10A is moved downward. At this time, a contact area with the die 10A in the outer peripheral surface of the molded body 41 is in sliding contact with the through hole 10b of the die 10A by a reaction force from the die 10A.
- the upper surface 10u of the die 10A and the upper surface 12u of the lower punch 12 are flush with each other, or the die 10A is moved until the upper surface 12u of the lower punch 12 is positioned above the upper surface 10u of the die 10A.
- the upper punch 11 is moved upward as shown in FIG.
- the die 10A is moved with the molded body 41 sandwiched between the lower surface 11d of the upper punch 11 and the upper surface 12u of the lower punch 12, and the upper punch 11 is moved in a subsequent process.
- the upper punch 11 may be moved upward, or the upper punch 11 may be moved before the die 10A.
- the molded body 41 can be removed by moving the upper punch 11, the molded body 41 can be taken out by, for example, a manipulator.
- the shape of the molded body 41 manufactured through the above steps is a shape in which the inner peripheral shape of the die 10A and the shapes of the lower surface 11d of the upper punch 11 and the upper surface 12u of the lower punch 12 are transferred. That is, as shown in FIG. 1 (F), the upper side of the drawing in FIG. 1 is a chord, the opposite side (the lower side of the drawing in the drawing) is an arc, and a part of the arc is cut away in parallel with the chord. It is an arcuate (bow-shaped) columnar body.
- This molded body 41 serves as an outer core included in the reactor. In this molded body 41, the opposing surface pressed by the upper punch 11 does not slide into contact with the mold during pressurization or demolding, so that it is difficult to form a conductive portion through which soft magnetic particles are conducted.
- the heat treatment temperature is preferably 300 ° C. or higher, particularly 400 ° C. or higher.
- the upper limit of the heat treatment temperature is about 800 ° C. If it is such heat processing temperature, the distortion introduce
- the time for performing the heat treatment may be appropriately selected according to the heat treatment temperature and the volume of the molded body so as to sufficiently remove the strain introduced into the soft magnetic particles in the molding process.
- it is preferably 10 minutes to 1 hour.
- the atmosphere for performing this heat treatment may be in the air, but it is particularly preferable to apply in an inert gas atmosphere. Thereby, it can suppress that a coated soft magnetic particle is oxidized with oxygen in air
- the facing surface of the outer core facing the inner core is pressed with the upper punch so that the facing surface is pressed or , Does not slidably contact the die when demolding. For this reason, the insulating coating of the coated soft magnetic powder on the facing surface is hardly damaged, and it is difficult to form a conducting portion where the soft magnetic particles are conducted.
- the conductive part is difficult to be formed on the facing surface, when the reactor is assembled so that the facing surface is perpendicular to the direction of the magnetic flux and the coil is excited, eddy current is hardly generated on the surface of the facing surface. Loss can be reduced. Therefore, it is possible to manufacture an outer core that is effective for reducing the loss of the reactor.
- the molding die 1 in the manufacturing method described above is such that the planar shape of the outer core is the dimension in the width direction along the opposite surface side on the opposite side of the outer core opposite to the side facing the inner core.
- Any shape of the upper punch 11, the lower punch 12, and the die 10A can be appropriately selected as long as an outer core having a small shape can be formed.
- an example in which a part of the molding die is different from the first embodiment will be described.
- the center portion of the lower surface 11p of the upper punch 11 in the width direction (the left-right direction in the drawing) is arranged in the depth direction (the left and right direction in the drawing).
- the upper punch 11 having a convex portion protruding toward the lower punch 12 side is used over the direction perpendicular to the paper surface of FIG.
- the molded body 42 is molded through the same molding process as in the first embodiment. Then, the upper punch 11 is moved upward as shown in FIG.
- the shape of the molded body 42 manufactured in this way is an opening on the paper surface of the drawing, and a part on the opposite side is cut away in parallel with the plane on the opening side. It is a substantially U-shaped (U-shaped) columnar body.
- This molded body 42 becomes an outer core included in the reactor.
- the opening side of the molded body 42 is disposed so as to be connected to the inner core. In that case, the vicinity of the connecting surface of the molded body 42 (outer core) is allowed to be covered with the coil in the circumferential direction.
- the die 10A of the molding die 1 has an inner peripheral shape of the die 10A (tapered hole 10c), the upper surface 10u side (lower end of the large rectangular hole 10p) of the die 10A is the long side, and the lower punch 12 side ( A die 10A having a trapezoidal shape (trapezoidal shape) having a short side at the upper end of 10r of the small rectangular hole is used.
- the molded body 43 is molded through the same molding process as in the first embodiment. Then, the upper punch 11 is moved upward as shown in FIG.
- the shape of the molded body 43 thus manufactured is a trapezoid (trapezoidal shape) in which the upper side in the figure is the long side, the lower direction in the figure is the short side, and both sides are parallel. It is a columnar body.
- This molded body 43 becomes an outer core included in the reactor.
- the long side of the molded body 43 is disposed on the inner core side of the reactor.
- the opposed surfaces on the long side of the molded body 43 are opposed to the end surfaces of the inner cores divided into left and right in the figure.
- Modification 3 With respect to the outer core of the first embodiment (FIG. 1), the opposing surface side rectangular surface having the opposing surface as a long side and the opposite side having the parallel surface opposite to the opposing surface as the long side.
- a method for manufacturing the outer core having at least one of the rectangular surfaces will be described.
- the shape of the die 10A and the position of the upper surface 12u of the lower punch 12 with respect to the die 10A are the first embodiment. And different.
- the shape of the upper punch 11 and the shape of the lower punch 12 and the thickness of the entire molded body to be molded are the same as in the first embodiment.
- differences from the first embodiment will be described.
- the die 10A, the overall thickness of the molded body 44, and the thickness of each rectangular surface in FIG. 4 are exaggerated.
- the thickness of the opposing surface side rectangular surface 44f is the thickness of the large rectangular hole 10q, more specifically, between the lower surface 11d of the upper punch 11 and the lower end of the large rectangular hole 10q. It can be adjusted appropriately according to the distance. Therefore, the thickness (depth) of the large rectangular hole 10q may be appropriately selected according to the desired thickness of the opposing surface side rectangular surface 44f.
- the opposing surface side rectangular surface 44f can be thickened as the thickness of the large rectangular hole 10q of the die 10A is increased and the distance between the lower surface 11d of the upper punch 11 and the lower end of the large rectangular hole 10q is increased.
- the thickness of the large rectangular hole 10q so that the thickness of the opposing-surface-side rectangular surface 44f is 0.3 mm or more and 2.0 mm or less. It is preferable to select it to be 5 mm or less. If the opposing surface side rectangular surface 44f is manufactured to have a thickness of 0.3 mm or more, the upper punch 11 can be sufficiently prevented from colliding with the tapered hole 10t on the inner peripheral surface of the die 10A. Further, by manufacturing the opposing surface side rectangular surface 44f to have a thickness of 2.0 mm or less, the coated soft magnetic powder on the opposing surface side can reduce the area in sliding contact with the die during pressurization or demolding. It is possible to suppress damage to the insulating coating.
- the molding die 1 when forming the molding space 31 in the filling process, the position of the upper surface 12u of the lower punch 12 with respect to the die 10A is added to the descending amount of the die 10A during pressurization.
- the lower punch 12 is disposed so as to be positioned on the lower opening side from the upper end of the small rectangular hole 10s by a desired thickness of the opposite rectangular surface 44o in the molded body 44 to be manufactured.
- the thickness of the opposite rectangular surface 44o (F in the figure) of the manufactured molded body 44 can be appropriately adjusted at the position of the upper surface 12u of the lower punch 12 with respect to the small rectangular hole 10s.
- the position of the upper surface 12u of the lower punch 12 may be appropriately selected according to the desired thickness of the opposite rectangular surface 44o.
- the thickness of the opposite rectangular surface 44o can be reduced, and conversely the lower end side of the small rectangular hole 10s.
- the thickness of the opposite rectangular surface 44o can be increased.
- t refers to the thickness from the facing surface of the manufactured molded body 44 to the opposite end surface. If the opposite rectangular surface is manufactured to have a thickness of 0.5 mm or more, it is possible to sufficiently prevent the lower punch 12 from entering the inside of the die 10A more than the small rectangular hole 10s during pressurization. By manufacturing the opposite rectangular surface 44o so that the thickness thereof is t / 2 or less, the opposite rectangular surface with respect to the entire outer core does not become too large.
- the opposing rectangular surface 44f has a thickness of the opposing rectangular surface 44f.
- the distance between the lower end of the large rectangular hole 10q and the lower surface 11d of the upper punch 11 and the distance between the upper end of the small rectangular hole 10q and the upper surface 12u of the lower punch 12 are appropriately selected so as to be thinner than 44o. It is preferable to do.
- the opposing surface side rectangular surface 44f is thin, when the reactor is constructed with the reactor, the opposing surface side arranged near the coil may reduce the sliding contact area with the die 10A during pressurization or demolding. It is possible to suppress damage to the insulating coating constituting the molded body. As a result, eddy current loss can be reduced.
- the molded body 44 is molded through a molding process similar to that of the first embodiment.
- the position of the upper surface 12u of the lower punch 12 with respect to the die 10A is positioned on the lower opening side from the upper end of the small rectangular hole 10s by the thickness of the opposite rectangular surface 44o of the molded body 44. Then, the upper punch 11 is moved upward as shown in FIG.
- the shape of the molded body 44 thus manufactured is such that the long side extends in the width direction from the upper side in the drawing to the opposite side (the lower side in the drawing).
- An opposing surface side rectangular surface 44f constituted by a rectangle, a long side of the rectangle as a chord, an arc on the opposite side, and a substantially arcuate shape in which a part of the arc is cut out parallel to the chord, It is a columnar body constituted by an opposite rectangular surface 44o constituted by a rectangle having one side formed by cutting out an arc.
- This molded body 44 becomes an outer core included in the reactor. In this compact 44, the reactor is constructed so that the surface pressed by the upper punch 11 becomes the opposing surface.
- Modification 4 In the modification 4, as shown in FIG. 5A, in the molding die 1 shown in the modification 1, the thickness of the large rectangular hole 10q and the position of the upper surface 12u of the lower punch 12 with respect to the die 10A are modified. 3, and a part of the upper punch 11 is different from the first modification. That is, when the thickness of the large rectangular hole 10q is made thicker than that of the first embodiment and the first modification, and the molding space 31 is formed in the filling process, the position of the upper surface 12u of the lower punch 12 is the die 10A in pressurization.
- the lower punch 12 is arranged so as to be positioned on the lower opening side from the upper end of the small rectangular hole 10s by a desired thickness of the opposite rectangular surface 45o in the molded body 45 to be manufactured.
- Modification 1 differences from Modification 1 will be described.
- the upper punch 11 having a convex portion protruding toward the lower punch 12 is used as in the first modification.
- the shape of the convex portion is a uniform rectangular surface 11q extending from the lower surface 11p of the upper punch 11 to the lower punch 12 side, and further formed from the rectangular surface 11q toward the lower punch 12 side.
- the bow shape is a string on the rectangular surface 11q side and an arc on the lower punch 12 side.
- the thickness of the rectangular surface 11q (the vertical direction in the figure) forms a linear region 45l in the opening of the manufactured molded body 45 (FIG. (F)). Therefore, the length of the straight region 45l can be appropriately selected depending on the thickness of the rectangular surface 11q.
- the molded body 45 is molded through the same molding process as in the first embodiment.
- the position of the upper surface 12u of the lower punch 12 with respect to the die 10A is positioned on the lower opening side from the upper end of the small rectangular hole 10s by the thickness of the opposite rectangular surface 45o of the molded body 45. Then, the upper punch 11 is moved upward as shown in FIG.
- the shape of the molded body 45 manufactured in this way is an opposing surface side rectangular surface 45f constituted by a rectangle having an opening in the upper surface of the drawing and having the linear region 45l.
- An opposite rectangular surface composed of a substantially U-shape in which a part on the opposite side is cut out in parallel with the plane on the opening side, and a rectangle that uniformly protrudes in the opposite direction from one side formed by the notch It is a columnar body composed of 45o.
- This molded body 45 becomes an outer core included in the reactor.
- the flat surface (connecting surface) on the opening side of the molded body 45 is arranged so as to be connected to the inner core. In that case, as in the first modification, the vicinity of the connection surface of the opposing surface side rectangular surface 45f of the molded body 45 (outer core) is allowed to be covered with the coil in the circumferential direction.
- the thickness of the large rectangular hole 10q and the position of the upper surface 12u of the lower punch 12 with respect to the die 10A are modified. Same as 3. That is, when the thickness of the large rectangular hole 10q is made thicker than that of the modified example 2 and the molding space 32 is formed in the filling process, the position of the upper surface 12u of the lower punch 12 corresponds to the descending portion of the die 10A during pressurization.
- the lower punch 12 is arranged so as to be positioned on the lower opening side from the upper end of the small rectangular hole 10s by a desired thickness of the opposite rectangular surface 46o in the molded body 46 to be manufactured.
- the molded body 46 is molded through the same molding process as in the first embodiment.
- the position of the upper surface 12u of the lower punch 12 with respect to the die 10A is positioned on the lower opening side from the upper end of the small rectangular hole 10s by the thickness of the opposite rectangular surface 46o of the molded body 46.
- the upper punch 11 is moved upward, and the molded body 46 is taken out.
- the shape of the molded body 46 thus manufactured is such that the opposite surface is a long side from the upper side in the drawing to the opposite side (the lower side in the drawing).
- This molded body 46 becomes an outer core included in the reactor.
- the long side of the molded body 46 is arranged on the inner core side included in the reactor as in the second modification. That is, the end surface of each inner core faces the opposing surface on the long side of the molded body 46 separately on the left and right in the figure.
- the molded body manufactured using the punch or die having the above-described shape is effective for reducing the reactor loss, and thus can be suitably used for the outer core of the reactor. . Further, by manufacturing the molded body so as to have a rectangular surface on the opposed surface side, collision between the upper punch and the tapered hole on the inner peripheral surface of the die can be prevented during pressurization. Therefore, the molding die is hardly damaged, and the life of the molding die is hardly reduced. In addition, during pressurization, it is easy to apply pressure to the molded body, and a high-density molded body can be manufactured.
- Embodiment 2 demonstrates an example of the reactor which provides the outer core manufactured by the above-mentioned manufacturing method. That is, the reactor of the present invention is characterized in that the outer core manufactured by the above-described manufacturing method is used for the outer core provided in the reactor.
- the other configuration is the same as that of the conventional reactor described with reference to FIGS. 7 and 8, but here, the configuration similar to that of the conventional reactor will be described below.
- As the outer core a reactor including the outer core manufactured by the manufacturing method described in the first embodiment will be described as an example.
- the reactor 100 includes a coil 105, an inner core 101 c disposed inside the coil 105, and an outer core 101 e exposed from the coil 105 as main constituent members.
- the exposure mentioned here includes a case where the entire outer core 101e is exposed and a case where a part of the outer core is surrounded by a turn as in the case where the outer core is U-shaped.
- the coil 105 has a pair of coil elements 105a and 105b formed by spirally winding one continuous winding 105w. Both coil elements 105a and 105b are arranged side by side so that the respective axial directions are parallel. Further, by positioning the winding end on one end side in the axial direction of the coil 105 and bending the winding on the other end side to provide the rewinding portion 105r (FIG. 8), one coil element 105a, 105b is provided. The winding is formed. And the coil
- winding uses the covered rectangular wire which gave the enamel coating for insulation to the rectangular copper wire. Each of the coil elements 105a and 105b is formed by winding a coated rectangular wire edgewise.
- various windings having a circular cross section and a polygonal cross section can be used.
- the pair of coil elements 105a and 105b may be separately manufactured, and the ends of the windings of both the coil elements 105a and 105b may be connected by welding or the like.
- the core 101 is an annular member composed of an inner core 101c and an outer core 101e.
- the inner core 101c is a portion where a coil is arranged on the outer periphery, and is composed of a magnetic core piece 101m and a gap portion g provided between the core pieces 101m for adjusting the inductance.
- a plate-like material made of a nonmagnetic material such as alumina can be used.
- the inner core 101c is configured by alternately laminating core pieces 101m and gap portions g and joining them with an adhesive or the like. In this example, a pair of inner cores 101c are arranged in parallel.
- the core piece 101m a compacted body obtained by press-molding a coated soft magnetic powder containing iron, or a laminated body obtained by laminating a plurality of electromagnetic steel sheets can be used.
- the outer core 101e is a molded body obtained by press-molding a coated soft magnetic powder and obtained by the above-described manufacturing method.
- the shape in plan view is a substantially bow shape (bow shape) having a string and an arc.
- the string side is arranged on the inner core 101c side.
- the base surface of the outer core 101e is positioned substantially at the same position as the base surfaces of the coil elements 105a and 105b. Further, the base surface of the outer core 101e protrudes downward (cooling base side) with respect to the base surface of the inner core 101c.
- the pair of inner cores 101c and the pair of outer cores 101e are connected to form a ring.
- an adhesive or the like can be used, and both the cores 101c and 101e may be directly connected or indirectly connected via a gap material similar to the gap part g.
- four core pieces 101m and three gap portions g are used as the inner core 101c, but the number of divisions of the core 101 and the number of gap portions g can be selected as appropriate.
- the insulator 107 is a member that ensures insulation between the core 101 and the coil 105, and is used as necessary.
- the insulator 107 includes a cylindrical portion 107b that covers the outer periphery of the inner core 101c of the core 101, and a pair of flange portions 107f that are in contact with the end face of the coil.
- the tubular portion 107b can easily cover the outer periphery of the inner core 101c by joining the half-cut square tube pieces together.
- the flange portion 107f is a member configured by a pair of rectangular frames integrated in a parallel state and disposed at one end portion of the tubular portion 107b.
- an insulating resin such as a polyphenylene sulfide (PPS) resin, a liquid crystal polymer (LCP), or a polytetrafluoroethylene (PTFE) resin can be used.
- PPS polyphenylene sulfide
- LCP liquid crystal polymer
- PTFE polytetra
- the reactor according to the embodiment described above includes an outer core that hardly generates eddy currents on the facing surface facing the side facing the inner core, so that iron loss can be reduced even when the coil is excited by high-frequency alternating current. .
- ⁇ Test example ⁇ As test examples, the following samples 1 to 4 were prepared, and the test described later was performed on the magnetic characteristics of each sample.
- Example 1 An iron powder having a purity of 99.8% or more prepared by a water atomization method was prepared as soft magnetic particles.
- the soft magnetic particles had an average particle size of 50 ⁇ m and an aspect ratio of 1.2. This average particle size was determined from the particle size of particles in which the sum of masses from particles with small particle sizes reached 50% of the total mass, that is, 50% particle size, in the particle size histogram.
- the surface of the metal particles was subjected to a phosphate chemical conversion treatment to form an insulating coating made of iron phosphate, thereby producing coated soft magnetic particles.
- the insulating coating substantially covered the entire surface of the soft magnetic particles, and the average thickness was 20 nm.
- the aggregate of the coated soft magnetic particles is a coated soft magnetic powder as a constituent material of the molded body.
- a lubricant containing zinc stearate is added to the coated soft magnetic powder so that the content is 0.6% by mass to prepare a mixture, and the mixture is a mold having a predetermined shape shown in the first embodiment (
- the molded body 41 having the shape shown in FIG. 1 was produced by injecting into FIG. 1) and press-molding it under a pressure of 588 MPa.
- Sample 2 differs from Sample 1 in the planar shape of the molded body. That is, molding is performed using a molding die different from the sample 1.
- a molded body having the same shape as the molded body 44 shown in FIG. 4F was manufactured using a mold having a predetermined shape shown in Modification 3 (FIG. 4).
- the thickness of the molded body was measured, the thickness of the entire molded body 44 was 24 mm, the thickness of the opposing surface side rectangular surface 44 f was 1.5 mm, and the thickness of the opposite rectangular surface 44 o was 10 mm. Met.
- sample 3 uses a mold having the same shape as that of the sample 2, but the thicknesses of the opposing-side rectangular surface 44f and the opposite-side rectangular surface 44o of the molded body 44 are different from those of the sample 2. That is, it was produced using a molding die 1 different from the sample 2 in the thickness of the large rectangular hole 10q and the position of the upper surface 12u of the lower punch 12 with respect to the die 10A.
- the thickness of the molded body 44 was measured, the overall thickness of the molded body 44 was 24 mm, the thickness of the opposing surface side rectangular surface 44 f was 5 mm, and the thickness of the opposite rectangular surface 44 o was 1 mm. there were.
- sample 4 is different from the sample 1 in the surface to be pressed with a punch. That is, the sample 2 was formed by pressing the surface (in the direction of the white arrow in FIG. 8) that is substantially perpendicular to the magnetic flux with the upper and lower punches.
- a measuring member for measuring magnetic characteristics was prepared by arranging a coil composed of a winding (each sample having the same specification) on each test magnetic core.
- Samples 1 to 3 had smaller eddy current loss than sample 4. This is because, when the samples 1 to 3 are manufactured, the surface through which the magnetic flux passes substantially orthogonally is pressed, so that the pressing surface does not slidably contact the die during pressing or demolding. For this reason, the insulating coating of the coated soft magnetic powder of the constituent material on this surface is not damaged, and it is difficult to form a conduction portion where the soft magnetic particles are conducted. Therefore, it is considered that eddy current loss can be reduced because eddy current hardly occurs on the pressing surface. Samples 1 and 2 had smaller eddy current loss than sample 3, and sample 1 and sample 2 had equivalent eddy current loss.
- sample 1 does not have a rectangular surface on the opposed surface side, and sample 2 has a thinner rectangular surface on the opposed surface side than sample 3;
- sample 2 has a thinner rectangular surface on the opposed surface side than sample 3;
- the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.
- it is configured to include both the opposing-surface-side rectangular surface and the opposite-side rectangular surface, but may be configured to include either one.
- the opening part of the molded object 45 in the modification 4 may be comprised only in the curve area
- a punch 11 may be used.
- the outer core of the present invention can be suitably used for a booster circuit such as a hybrid vehicle and a reactor used for power generation / transforming equipment. Moreover, the manufacturing method of this invention outer core can be utilized suitably for manufacture of the outer core of a reactor.
- the reactor of the present invention can be used as a component of a power conversion device such as a DC-DC converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Soft Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
(A)外側コアの内側コアとの対向側を弦、その反対側を弧とする弓形状。
(B)外側コアの内側コアとの対向側を長辺とする台形状。
(C)外側コアの内側コアとの対向側が開口部となるU字状。
(D)上記対向面における上記第二パンチの加圧面と平行な面を長辺とする対向面側矩形状面。
(E)上記対向面の反対側の面で当該対向面と平行な面を長辺とする反対側矩形状面。
〔外側コアの製造方法〕
本発明の外側コアの製造方法は、リアクトルに具わる外側コアを加圧成形により製造する方法である。そのリアクトルは、詳しくは後述するが、図7に示すように、コイル105と内側コア101cと外側コア101eとを具える。具体的には、コイル105は、巻線105wを螺旋状に巻回した一対のコイル素子105a、105bを互いに並列状態で接続してなる。内側コア101cは、両コイル素子105a、105bの内側に配される。外側コア101eは、コイル105から露出し、各内側コア101cと連結して当該内側コア101cと環状のコア101を形成する。その上、内側コア101cとの連結面を含むと共に、他方の外側コア101eと対面する対向面を有する。連結面の各々は、平面で構成され、互いに面一に配置されている。また、両連結面を含む対向面も平面である。そして、外側コア101eを環状のコア101の軸方向から平面視した場合、外側コア101eの平面形状は、外側コア101eの内側コア101cとの対向側よりも、その反対側の方が、上記対向面に沿った幅方向の寸法が小さい形状である。この外側コア101eの具体的な製造方法として、準備工程と、成形工程とを具える。以下、製造に使用する成形用金型を説明してから、各工程を順に説明する。
本発明の製造方法で使用される金型は、代表的には、貫通孔が設けられた筒状のダイと、ダイの貫通孔の各開口部からそれぞれ挿入可能な一対の柱状の第一パンチおよび第二パンチとを具える。この一対の第一パンチと第二パンチは、貫通孔内で対向して配置される。この金型では、一方のパンチの一面(他方のパンチとの対向する圧接面)とダイの内周面とで有底筒状の成形空間を形成する。この成形空間内に後述する原料粉末を充填し、両パンチで加圧・圧縮して、外側コアを製造する。両パンチの各対向面は、外側コアの各端面を形成し、ダイの内周面が外側コアの外周面を形成する。
ダイに設ける貫通孔の内周の縦断面形状は、上記外側コアを平面視した形状に対応した形状であればよい。例えば、ダイの一方のパンチ側よりも他方のパンチ側の方が、ダイの幅方向の寸法が小さくなる内周形状を具えていればよい。加えて、上記内周形状は、上記外側コアの上記内側コアとの対向面を一方のパンチで加圧できるような形状であれば特に問わない。具体的には、ダイに設ける貫通孔は、一方のパンチが挿通される大矩形孔と、他方のパンチが挿通される小矩形孔と、両矩形孔の間に大矩形孔から小矩形孔にかけて幅方向の寸法が小さくなり、いずれのパンチも挿通されないテーパー孔とで構成される。即ち、大矩形孔の内周面は、一方のパンチの側面と平行な平行領域で、小矩形孔の内周面は、他方のパンチの側面と平行な平行領域で、テーパー孔における内周面はいずれのパンチの側面とも平行しない非平行領域である。
上パンチ11及び下パンチ12は、ダイの貫通孔に挿通することができる柱状体である。上パンチ11において下パンチ12と対向する下面11dは、ダイ10Aがつくる空間に適合した形状となっている。上パンチ11の下面11dの形状が、外側コアにおける内側コアとの対向面の形状を形成する。ここでは、上パンチ11の下面11dは矩形状の平面であり、上パンチ11の方が下パンチ12よりも幅(図1の左右方向の距離)が広い。この上パンチ11で加圧成形された成形体の上パンチ11に対応する面は矩形状の平面となる。上パンチ11及び下パンチ12の各々はいずれも、四角柱部材の一体成形物としている。
一対のパンチの少なくとも一方とダイとは、相対的に移動可能である。図1に示す成形用金型1では、下パンチ12が図示しない本体装置に固定されて不動であり、ダイ10A及び上パンチ11が図示しない移動機構によりそれぞれ上下方向に移動可能な構成である。その他、ダイ10Aが固定されて両パンチ11、12が移動可能な構成、ダイ10A及び両パンチ11、12のいずれもが移動可能な構成とすることができる。一方のパンチ(ここでは下パンチ12)を固定することで、移動機構が複雑にならず、移動操作を制御し易い。
本発明製造方法では、成形用金型(特に、ダイの内周面)に潤滑剤を塗布することができる。潤滑剤は、ステアリン酸リチウムなどの金属石鹸、ステアリン酸アミドなどの脂肪酸アミド、エチレンビスステアリン酸アミドなどの高級脂肪酸アミドなどの固体潤滑剤、固体潤滑剤を水などの液媒に分散させた分散液、液状潤滑剤などが挙げられる。但し、潤滑剤の使用量(塗布厚さ)が少ないほど、磁性成分の割合が高い圧粉成形体が得られる。
準備工程では、上記外側コアの原料粉末である被覆軟磁性粉末を用意する。被覆軟磁性粉末は、軟磁性粒子の外周に絶縁被膜が被覆された被覆軟磁性粒子を複数具える。
(組成)
軟磁性粒子は、鉄を50質量%以上含有するものが好ましく、鉄合金、例えば、Fe-Si系合金、Fe-Al系合金、Fe-N系合金、Fe-Ni系合金、Fe-C系合金、Fe-B系合金、Fe-Co系合金、Fe-P系合金、Fe-Ni-Co系合金、及びFe-Al-Si系合金から選択される少なくとも1種からなるものが利用できる。そうすれば、渦電流損を低減し易く、より損失低減できる。特に、透磁率及び磁束密度の点からみれば、99質量%以上がFeである純鉄が好ましい。
軟磁性粒子の平均粒径は、圧粉成形体として低損失に寄与するサイズであればよい。つまり、特に限定することなく適宜選択することができるが、例えば、1μm以上150μm以下であれば好ましい。軟磁性粒子の平均粒径を1μm以上とすることによって、軟磁性粉末の流動性を落とすことがなく、軟磁性粉末を用いて製作された圧粉成形体の保磁力およびヒステリシス損の増加を抑制できる。逆に、軟磁性粒子の平均粒径を150μm以下とすることによって、1kHz以上の高周波域において発生する渦電流損を効果的に低減できる。より好ましい軟磁性粒子の平均粒径は、40μm以上100μm以下である。この平均粒径の下限が40μm以上であれば、渦電流損の低減効果が得られると共に、被覆軟磁性粉末の取り扱いが容易になり、より高い密度の成形体とすることができる。なお、この平均粒径とは、粒径のヒストグラム中、粒径の小さい粒子からの質量の和が総質量の50%に達する粒子の粒径、つまり50%粒径をいう。
軟磁性粒子の形状は、アスペクト比が1.2~1.8となるようにすると好ましい。このアスペクト比とは、粒子の最大径と最小径との比とする。上記範囲のアスペクト比を有する軟磁性粒子は、アスペクト比が小さな(1.0に近い)ものに比べて、圧粉成形体にしたときに反磁界係数を大きくでき、磁気特性に優れた圧粉成形体とすることができる。その上、圧粉成形体の強度を向上させることができる。
軟磁性粒子は、水アトマイズ法やガスアトマイズ法などのアトマイズ法で製造されたものが好ましい。水アトマイズ法で製造された軟磁性粒子は、粒子表面に凹凸が多いため、その凹凸の噛合により高強度の成形体を得やすい。一方、ガスアトマイズ法で製造された軟磁性粒子は、その粒子形状がほぼ球形のため、絶縁被膜を突き破るような凹凸が少なくて好ましい。軟磁性粒子の表面には、自然酸化膜が形成されていても良い。
絶縁被膜は、隣接する軟磁性粒子同士を絶縁するために、軟磁性粒子に被覆される。軟磁性粒子を絶縁被膜で覆うことによって、軟磁性粒子同士の接触を抑制し、成形体の比透磁率を抑えることができる。その上、絶縁被膜の存在により、軟磁性粒子間に渦電流が流れるのを抑制して、圧粉成形体の渦電流損を低減させることができる。
絶縁被膜は、軟磁性粒子同士の絶縁を確保できる程度の絶縁性に優れるものであれば特に限定されない。例えば、絶縁被膜の材料は、リン酸塩、チタン酸塩、シリコーン樹脂、リン酸塩とシリコーン樹脂の2層からなるものなどが挙げられる。
絶縁被膜の平均厚さは、隣接する軟磁性粒子同士を絶縁することができる程度の厚みであればよい。例えば、10nm以上1μm以下であることが好ましい。絶縁被膜の厚みを10nm以上とすることによって、軟磁性粒子同士の接触の抑制や渦電流によるエネルギー損失を効果的に抑制することができる。一方、絶縁被膜の厚みを1μm以下とすることによって、被覆軟磁性粒子に占める絶縁被膜の割合が大きくなりすぎず、被覆軟磁性粒子の磁束密度が著しく低下することを防止できる。
軟磁性粒子に絶縁被膜を被覆する方法としては、適宜選択するとよい。例えば、加水分解・縮重合反応などにより被膜することが挙げられる。軟磁性粒子と絶縁被膜を構成する原料とを配合して、その配合体を、加熱した状態で混合する。そうすることで、軟磁性粒子を被膜原料に十分に分散でき、個々の軟磁性粒子の外側に絶縁被膜を被覆することができる。
成形工程では、上述した成形用金型1を用いて被覆軟磁性粉末の加圧成形を行う。この工程では、金型1のうち下パンチ12と筒状ダイ10Aとで作られる成形空間31に上記外側コアの原料粉末Pである被覆軟磁性粉末を充填し、上パンチ11と下パンチ12とにより上記成形空間31内の被覆軟磁性粉末を加圧成形する。
(充填工程)
まず、図1(A)に示すように、上パンチ11をダイ10Aにおける貫通孔10bの上方の所定の待機位置に移動する。また、ダイ10Aを上方に移動して、下パンチ12の上面12uと、ダイ10Aの貫通孔10bとで所定の成形空間31を形成する。その際、次の加圧工程において、加圧した際にダイ10Aが下降する距離の分を考慮して下パンチ12を配置すればよい。ここでは、下パンチ12の上面12uが、ダイ10Aの小矩形孔10rにおいて、加圧の際におけるダイ10Aの下降分だけ小矩形孔10rの上端からダイ10Aの下開口部側に位置するように下パンチ12を配置する。
図1(C)に示すように、上パンチ11を下方に移動してダイ10Aの貫通孔10bの大矩形孔10pに挿入して、両パンチ11,12により、原料粉末Pを加圧・圧縮する。
所定の加圧を行った後、図1(D)に示すように、成形体41に対して、ダイ10Aを相対的に移動させる。ここでは、成形体41を移動せず、ダイ10Aのみを下方に移動する。このとき、成形体41の外周面のうち、ダイ10Aとの接触領域は、ダイ10Aからの反力によりダイ10Aの貫通孔10bに摺接する。
その他の工程として、上記成形工程後、成形体に対して成形工程で軟磁性粒子に導入された歪を除去するために加熱する熱処理工程を施すことが好ましい。
上述した実施形態によれば、以下の効果を奏する。
以下、実施形態1に係る製造方法の変形例を説明する。上述した製造方法における成形用金型1は、外側コアの平面形状が、上記外側コアの上記内側コアとの対向側よりも、その反対側の方が、対向面側に沿った幅方向の寸法が小さい形状である外側コアを成形できれば、上パンチ11、下パンチ12、ダイ10Aのいずれの形状も適宜選択することができる。以下の変形例では、実施形態1とは、成形用金型の一部の形状等が異なる例を説明する。
変形例1では、図2(A)に示すように、外側コアを成形するための成形用金型1のうち、上パンチ11の形状が実施形態1と相違する。但し、ダイ10Aと下パンチ12の形状は実施形態1と同様である。以下、実施形態1と相違する点について説明する。
本例では、成形用金型1の上パンチ11に、図2(A)に示すように、上パンチ11の下面11pにおける幅方向(同図の紙面左右方向)の中央部が、奥行方向(同図の紙面垂直方向)に亘って、下パンチ12側に突出する凸部を有している上パンチ11を使用する。
変形例2では、図3に示すように、外側コアを形成するための成形用金型1のうち、ダイ10Aに設ける貫通孔10hの内周形状が実施形態1と相違する。但し、上下のパンチ11、12の形状は実施形態1と同様である。以下、実施形態1と相違する点について説明する。
本例では、成形用金型1のダイ10Aに、ダイ10A(テーパー孔10c)の内周形状が、ダイ10Aの上面10u側(大矩形孔10pの下端)を長辺、下パンチ12側(小矩形孔の10rの上端)を短辺とする台形(台形状)であるダイ10Aを使用する。
変形例3では、実施形態1の外側コア(図1)に対して、さらに対向面を長辺とする対向面側矩形状面と、対向面の反対側の平行面を長辺とする反対側矩形状面の少なくとも一方を具える外側コアの製造方法を説明する。本例では、図4(A)に示すように、外側コアを成形するための成形用金型1のうち、ダイ10Aの形状と、ダイ10Aに対する下パンチ12の上面12uの位置が実施形態1と相違する。但し、上パンチ11の形状および下パンチ12の形状、及び成形される成形体全体の厚さは実施形態1と同様である。以下、実施形態1と相違する点について説明する。ここでは、説明の便宜上、図4のダイ10A、成形体44の全体厚さ、及び各矩形状面の厚さは誇張して示す。
本例では、ダイ10Aとして、図4(A)に示すように、大矩形孔10qの厚さ(同図の紙面上下方向)が、実施形態1よりも厚いものを使用する。ダイ10Aに対する上パンチ11の下面11dの位置は、大矩形孔10qの厚さを厚くしたため、加圧完了時において、大矩形孔10qの下端まで達しない。そのため、大矩形孔10qの厚くした厚さ分、即ち、上パンチ11の下面11dと大矩形孔10qの下端との間の厚さ分、対向面を長辺とする対向面側矩形状面44fが、成形体44に形成される。つまり、対向面側矩形状面44f(同図F)の厚さは、大矩形孔10qの厚さ、より具体的には、上パンチ11の下面11dと大矩形孔10qの下端との間の距離によって適宜調節可能である。そのため、大矩形孔10qの厚さ(深さ)は、対向面側矩形状面44fの所望の厚さに応じて適宜選択すればよい。例えば、ダイ10Aの大矩形孔10qの厚さを厚くして、上パンチ11の下面11dと大矩形孔10qの下端との距離を長くするほど対向面側矩形状面44fを厚くできる。そうして、対向面側矩形状面44fの厚さが、0.3mm以上2.0mm以下となるように、大矩形孔10qの厚さを選択することが好ましく、特に、0.5mm以上1.5mm以下となるように選択することが好ましい。対向面側矩形状面44fの厚さが0.3mm以上となるように製造すれば、上パンチ11がダイ10Aの内周面におけるテーパー孔10tに衝突することを十分に防止できる。また、対向面側矩形状面44fの厚さを2.0mm以下となるように製造することで、対向面側の被覆軟磁性粉末が、加圧また脱型時に、ダイと摺接する領域を少なくすることができ、絶縁被膜の損傷を抑制できる。
また、本例では、成形用金型1において、充填工程において成形空間31を形成する際、ダイ10Aに対する下パンチ12の上面12uの位置が、加圧の際におけるダイ10Aの下降分に加えて、製造する成形体44における反対側矩形状面44oの所望の厚さ分、小矩形孔10sの上端から下開口部側に位置するように下パンチ12を配置する。製造された成形体44の反対側矩形状面44o(同図F)の厚さは、小矩形孔10sに対する下パンチ12の上面12uの位置で適宜調節可能である。そのため、反対側矩形状面44oの所望の厚さに応じて、下パンチ12の上面12uの位置を適宜選択すればよい。例えば、ダイ10Aに対する下パンチ12の上面12uの位置を、小矩形孔10sの上端側に配置することで、反対側矩形状面44oの厚さを薄くでき、逆に小矩形孔10sの下端側(下開口部側)に配置することで、反対側矩形状面44oの厚さを厚くできる。そうして、反対側矩形状面44oの厚さが、0.5mm以上t/2以下となるように、下パンチ12の上面12uの位置を適宜選択することが好ましく、特に、1.0mm以上t/2以下となるように選択することが好ましい。ここでいう「t」とは、製造された成形体44の対向面からその反対側の端面までの厚さをいう。反対側矩形状面の厚さが0.5mm以上となるように製造すれば、加圧時に下パンチ12が小矩形孔10sよりもダイ10A内側に入りすぎることを十分に防止できる。反対側矩形状面44oの厚さがt/2以下となるように製造することで、外側コア全体に対する反対側矩形状面が大きくなり過ぎない。
変形例4では、図5(A)に示すように、変形例1で示した成形用金型1において、大矩形孔10qの厚さと、ダイ10Aに対する下パンチ12の上面12uの位置は変形例3と同様とし、上パンチ11の一部の形状が変形例1と相違する。即ち、大矩形孔10qの厚さを実施形態1及び変形例1よりも厚くし、充填工程において成形空間31を形成する際、下パンチ12の上面12uの位置が、加圧の際におけるダイ10Aの下降分に加えて、製造する成形体45における反対側矩形状面45oの所望の厚さ分、小矩形孔10sの上端から下開口部側に位置するように下パンチ12を配置する。以下、変形例1と相違する点について説明する。
本例では、変形例1と同様に下パンチ12側に突出する凸部を有する上パンチ11を使用する。この凸部の形状は、図5に示すように、上パンチ11の下面11pから下パンチ12側に延びる一様な矩形状面11qと、矩形状面11qからさらに下パンチ12側に向かって形成される弓形状とで構成され、その弓形状は、矩形状面11q側を弦、下パンチ12側を弧とする。この凸部において矩形状面11qの厚さ(同図の紙面上下方向)が、製造された成形体45(同図(F))の開口部における直線領域45lを形成する。そのため、直線領域45lの長さは、上記矩形状面11qの厚さにより適宜選択することができる。
変形例5では、図6(A)に示すように、変形例2で示した成形用金型1において、大矩形孔10qの厚さと、ダイ10Aに対する下パンチ12の上面12uの位置を変形例3と同様にした。即ち、大矩形孔10qの厚さを変形例2よりも厚くし、充填工程において成形空間32を形成する際、下パンチ12の上面12uの位置が、加圧の際におけるダイ10Aの下降分に加えて、製造する成形体46における反対側矩形状面46oの所望の厚さ分、小矩形孔10sの上端から下開口部側に位置するように下パンチ12を配置する。
上述した変形例によれば、上述の形状を有するパンチやダイを使用して製造された成形体は、リアクトルの損失低減に効果的であるため、リアクトルの外側コアに好適に利用することができる。また、成形体が対向面側矩形状面を具えるように製造することで、加圧の際、上パンチとダイの内周面におけるテーパー孔との衝突を防止できる。そのため、成形用金型が損傷し難く、成形用金型の寿命が低下し難い。加えて、加圧の際、圧力を成形体に付加し易く、高密度な成形体を製造することができる。反対側矩形状面を具えないように製造する場合、下パンチの上面が小矩形孔よりもダイ内部側(上パンチ側)に入りこまないように、加圧工程における加圧完了時、下パンチの上面を小矩形孔の上端に厳密に位置合わせする必要がある。一方、反対側矩形状面を具えるように製造する場合、加圧完了時、下パンチの上面を小矩形孔の途中に位置させるため、相対的に下パンチが小矩形孔よりもダイ内部側(上パンチ側)に入ることを十分に防止できる。そのため、反対側矩形状面を具えるように製造する場合、具えないように製造する場合ほど、下パンチの上面の位置を常時厳密に位置決めしなくても、外側コアの対向面の反対側の幅方向両端に欠け易い鋭角な角部の形成を防止できる。つまり、連続成形する際などに成形速度を速くでき、生産性に優れる。
実施形態2では、上述の製造方法により製造される外側コアを具えるリアクトルの一例を説明する。つまり、本発明のリアクトルは、リアクトルに具わる外側コアに上述の製造方法により製造された外側コアを用いる点に特徴がある。それ以外の構成は、図7、8を用いて説明した従来のリアクトルと同様であるが、ここでは、従来のリアクトルと同様の構成も含めて以下に説明する。外側コアは、実施形態1で説明した製造方法により製造された外側コアを具えるリアクトルを例に説明する。
リアクトル100は、図7に示すように、コイル105と、コイル105の内側に配される内側コア101cと、コイル105から露出する外側コア101eとを主要構成部材とする。ここで言う露出とは、外側コア101eの全部が露出している場合と、上述した外側コアがU字状である場合のように、極一部がターンに囲まれている場合とを含む。
コイル105は、1本の連続する巻線105wを螺旋状に巻回してなる一対のコイル素子105a、105bを有する。両コイル素子105a、105bは、各軸方向が並列するように横並びに配置される。また、コイル105の軸方向一端側に巻線端部を位置させ、他端側において巻線を屈曲させて巻返し部105r(図8)を設けることで、両コイル素子105a、105bを一本の巻線で形成している。そして、巻線には、銅製の平角線に絶縁のためのエナメル被覆を施した被覆平角線を利用している。各コイル素子105a、105bは、被覆平角線をエッジワイズ巻きにして形成される。平角線以外に、断面が円形状、多角形状などの種々の巻線を利用できる。一対のコイル素子105a、105bを別々に作製し、両コイル素子105a、105bの巻線の端部を溶接などで接続してもよい。
コア101は、内側コア101cと外側コア101eとで構成される環状の部材である。
インシュレータ107は、コア101とコイル105との間の絶縁を確保する部材で、必要に応じて用いられる。インシュレータ107は、コア101の内側コア101cの外周を覆う筒状部107bと、コイルの端面に当接される一対の鍔部107fとを備える。筒状部107bは、半割れの角筒片同士を接合することで内側コア101cの外周を容易に覆うことができる。鍔部107fは、並列状態に一体化された一対の矩形枠で構成され、筒状部107bの一端部に配置される部材である。そして、インシュレータ107には、ポリフェニレンスルフィド(PPS)樹脂、液晶ポリマー(LCP),ポリテトラフルオロエチレン(PTFE)樹脂などの絶縁性樹脂が利用できる。
上述した実施形態に係るリアクトルは、内側コアと対向する側に面する対向面に渦電流が生じ難い外側コアを具えているため、コイルが高周波の交流で励磁される場合でも鉄損を低減できる。
試験例として、以下の試料1~4を作製し、それら各試料の磁気特性について後述する試験を行った。
水アトマイズ法により作製された、純度が99.8%以上である鉄粉を軟磁性粒子として用意した。この軟磁性粒子の平均粒径が50μmで、そのアスペクト比は1.2であった。この平均粒径は、粒径のヒストグラム中、粒径の小さい粒子からの質量の和が総質量の50%に達する粒子の粒径、つまり50%粒径により求めた。そして、この金属粒子の表面にリン酸塩化成処理を施して、リン酸鉄からなる絶縁被膜を形成し、被覆軟磁性粒子を作製した。絶縁被膜は、軟磁性粒子の表面全体を実質的に覆い、その平均厚さは、20nmであった。被覆軟磁性粒子の集合体が、成形体の構成材料の被覆軟磁性粉末である。
試料2は、試料1とは、成形体の平面形状が異なる。即ち、試料1とは異なる成型用金型を用いて成形する。ここでは、変形例3に示した所定の形状の金型(図4)を用いて、同図(F)に示す成形体44と同様の形状の成形体を作製した。成形した成形体の厚さを測定したところ、この成形体44全体の厚さは24mmで、対向面側矩形状面44fの厚さが1.5mm、反対側矩形状面44oの厚さが10mmであった。
試料3は、試料2と同様の形状の金型を用いるが、成形体44における対向面側矩形状面44fと反対側矩形状面44oのそれぞれの厚さが試料2と異なる。即ち、大矩形孔10qの厚さ、及びダイ10Aに対する下パンチ12の上面12uの位置が試料2と異なる成形用金型1を用いて作製した。成形した成形体44の厚さを測定したところ、この成形体44全体の厚さは24mmで、対向面側矩形状面44fの厚さが5mm、反対側矩形状面44oの厚さが1mmであった。
試料4は、試料1とは、パンチで加圧する面が異なる。つまり、試料2は、加圧成形の際、磁束と略垂直となる面(図8の白抜き矢印方向)を上下のパンチで加圧成形して成形体を作製した。
以上の工程を経て作製した試料1~4と、同試料と同様の材料で、同様の条件により作製した直方体の複数の圧粉成形体とを、窒素雰囲気下で400℃×30分、熱処理して熱処理材を得た。得られた各試料の熱処理材と圧粉成形体の熱処理材とを環状に組み合わせて試験用磁心を作製し、以下の磁気特性値を測定した。その際、試料1~3では、成形体の加圧面が直方体と対向するように環状に組み合わせた。
各試験用磁心に巻線で構成したコイル(いずれの試料も同様の仕様のもの)を配置して磁気特性を測定するための測定部材を作製した。この測定部材について、AC-BHカーブトレーサを用いて、励起磁束密度Bm:1kG(=0.1T)、測定周波数:5kHzにおける試料の渦電流損We(W)を求めた。その結果を表1に示す。
試料1~3は試料4よりも渦電流損が小さかった。これは、試料1~3を作製する際、磁束が略直交して通過する面を加圧することで、その加圧面は、加圧の際、あるいは、脱型時にダイと摺接しない。そのため、この面における構成材料の被覆軟磁性粉末の絶縁被膜が損傷せず、軟磁性粒子同士が導通する導通部を形成し難い。したがって、加圧面に渦電流が発生し難いので、渦電流損を低減できたと考えられる。また、試料1、2は試料3よりも渦電流損が小さく、試料1と試料2は同等の渦電流損であった。これは、試料1は、対向面側矩形状面を具えていないため、また、試料2は試料3よりも対向面側矩形状面の厚さが薄いため、試料1と試料2は、試料3と比較すると、成形の際、特に脱型時において対向面側で金型と摺接する箇所がほとんどなかった、または少なかった。即ち、コイル近傍に配される対向面側における絶縁被膜の損傷を低減でき、試料1、2ではさらに周方向に生じる渦電流の発生を試料3よりも抑制できたからであると考えられる。
10A ダイ 10b、10h 貫通孔 10u 上面
10p、10q 大矩形孔 10r、10s 小矩形孔
10c、10t テーパー孔
11 上パンチ 11d、11p 下面 11q 矩形状面
12 下パンチ 12u 上面
31、32 成形空間
41、42、43、44、45、46 成形体
44f、45f、46f 対向面側矩形状面
44o、45o、46o 反対側矩形状面
45l 直線領域
P 原料粉末
100 リアクトル
101 コア
101c 内側コア
101e 外側コア 101m コア片 g ギャップ部
105 コイル
105a,105b コイル素子 105w 巻線 105r 巻返し部
107 インシュレータ
107b 筒状部 107f 鍔部
Claims (9)
- 巻線を螺旋状に巻回した一対のコイル素子を互いに並列状態で接続したコイルと、前記各コイル素子の内側に配される一対の内側コアと、前記コイルから露出し、各内側コアと連結して当該内側コアと環状のコアを形成する一対の外側コアとを具えるリアクトルにおける外側コアを加圧成形により製造する外側コアの製造方法であって、
前記外側コアは、前記内側コアとの連結面を含むと共に、前記内側コアを挟んで他方の外側コアと対面する対向面を有し、
前記外側コアを前記環状のコアの軸方向から平面視した場合、前記外側コアの平面形状は、前記外側コアの前記内側コアとの対向側よりも、その反対側の方が、前記対向面に沿った幅方向の寸法が小さい形状であり、
前記外側コアの原料粉末として、軟磁性粒子に絶縁被膜が被覆された被覆軟磁性粒子を複数具えてなる被覆軟磁性粉末を用意する準備工程と、
相対的に移動可能な柱状の第一パンチと筒状ダイとで作られる成形空間に、前記被覆軟磁性粉末を充填し、前記第一パンチと当該第一パンチと対向配置された柱状の第二パンチとにより前記成形空間内の被覆軟磁性粉末を加圧成形する成形工程とを具え、
前記成形工程では、前記外側コアにおける前記対向面を前記第二パンチで加圧することを特徴とする外側コアの製造方法。 - 前記軟磁性粒子が、純鉄であることを特徴とする請求項1に記載の外側コアの製造方法。
- 前記外側コアの平面形状が、下記(A)~(C)のいずれかであることを特徴とする請求項1または2に記載の外側コアの製造方法。
(A)前記外側コアの前記内側コアとの対向側を弦、その反対側を弧とする弓形状。
(B)前記外側コアの前記内側コアとの対向側を長辺とする台形状。
(C)前記外側コアの前記内側コアとの対向側が開口部となるU字状。 - 前記外側コアの平面形状が、さらに、下記(D)と(E)の少なくとも一方を具えることを特徴とする請求項3に記載の外側コアの製造方法。
(D)前記対向面における前記第二パンチの加圧面と平行な面を長辺とする対向面側矩形状面。
(E)前記対向面の反対側の面で当該対向面と平行な面を長辺とする反対側矩形状面。 - 前記対向面側矩形状面の厚さが、0.3mm以上2.0mm以下であることを特徴とする請求項4に記載の外側コアの製造方法。
- 前記外側コアの対向面から当該対向面の反対側の面までの厚さをtとするとき、
前記反対側矩形状面の厚さが、0.5mm以上t/2以下であることを特徴とする請求項4または5に記載の外側コアの製造方法。 - 前記対向面側矩形状面の厚さが、前記反対側矩形状面の厚さよりも薄いことを特徴とする請求項4~6のいずれか1項に記載の外側コアの製造方法。
- 請求項1~7のいずれか1項に記載の外側コアの製造方法により製造されたことを特徴とする外側コア。
- 巻線を螺旋状に巻回した一対のコイル素子を互いに並列状態で接続したコイルと、
前記両コイル素子の内側に配される内側コアと、
前記コイルから露出し、前記各内側コアと対向する側に面する対向面を有して当該内側コアと環状のコアを形成する外側コアとを具え、
前記外側コアは、請求項8に記載の外側コアであることを特徴とするリアクトル。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/812,997 US8922323B2 (en) | 2011-03-30 | 2012-02-09 | Outer core manufacturing method, outer core, and reactor |
CN201280002197.1A CN103038843B (zh) | 2011-03-30 | 2012-02-09 | 外芯制造方法、外芯、以及电抗器 |
EP12765517.3A EP2587501B1 (en) | 2011-03-30 | 2012-02-09 | Method for manufacturing outer core, outer core, and reactor |
MYPI2013700154A MY184994A (en) | 2011-03-30 | 2012-02-09 | Method for manufacturing outer core, outer core, and reactor |
KR1020137002440A KR101418690B1 (ko) | 2011-03-30 | 2012-02-09 | 외측 코어의 제조 방법, 외측 코어 및 리액터 |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011-075738 | 2011-03-30 | ||
JP2011075738 | 2011-03-30 | ||
JP2011-181631 | 2011-08-23 | ||
JP2011181631A JP5096605B2 (ja) | 2011-03-30 | 2011-08-23 | 外側コアの製造方法、外側コア、およびリアクトル |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012132565A1 true WO2012132565A1 (ja) | 2012-10-04 |
Family
ID=46930330
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/052942 WO2012132565A1 (ja) | 2011-03-30 | 2012-02-09 | 外側コアの製造方法、外側コア、およびリアクトル |
Country Status (7)
Country | Link |
---|---|
US (1) | US8922323B2 (ja) |
EP (1) | EP2587501B1 (ja) |
JP (1) | JP5096605B2 (ja) |
KR (1) | KR101418690B1 (ja) |
CN (1) | CN103038843B (ja) |
MY (1) | MY184994A (ja) |
WO (1) | WO2012132565A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140375413A1 (en) * | 2013-06-21 | 2014-12-25 | Samsung Electro-Mechanics Co., Ltd. | Metal magnetic powder and method for forming the same, and inductor manufactured using the metal magnetic powder |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8854171B2 (en) * | 2010-11-17 | 2014-10-07 | Electric Torque Machines Inc. | Transverse and/or commutated flux system coil concepts |
JP5831941B2 (ja) * | 2011-03-30 | 2015-12-09 | 住友電気工業株式会社 | 外側コアの製造方法 |
JP2013171855A (ja) * | 2012-02-17 | 2013-09-02 | Hitachi Powdered Metals Co Ltd | 分割コア |
JP5964619B2 (ja) | 2012-03-15 | 2016-08-03 | 株式会社タムラ製作所 | リアクトル、及びリアクトルの製造方法 |
JP6301596B2 (ja) * | 2013-06-19 | 2018-03-28 | 株式会社タムラ製作所 | リアクトル及びリアクトルの製造方法 |
US10073058B2 (en) * | 2015-02-11 | 2018-09-11 | Structural Integrity Associates | Dynamic pulsed eddy current probe |
US10895555B2 (en) | 2015-03-30 | 2021-01-19 | Structural Integrity Associates, Inc. | System for in-line inspection using a dynamic pulsed eddy current probe and method thereof |
JP6624520B2 (ja) * | 2017-02-28 | 2019-12-25 | 株式会社オートネットワーク技術研究所 | リアクトル |
CN108481877B (zh) * | 2018-03-10 | 2020-06-23 | 葛理想 | 电磁屏蔽用磁材的碎化处理工艺 |
JP7215036B2 (ja) * | 2018-09-21 | 2023-01-31 | 株式会社オートネットワーク技術研究所 | リアクトル |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04168201A (ja) * | 1990-10-31 | 1992-06-16 | Kobe Steel Ltd | セラミックス強化Al合金複合材料の製造方法 |
JP2000144211A (ja) * | 1998-11-06 | 2000-05-26 | Toshiba Tungaloy Co Ltd | 粉末成形用の金型及び圧粉体の成形方法並びに切削用のポジチップ |
JP2008160020A (ja) * | 2006-12-26 | 2008-07-10 | Toyota Motor Corp | リアクトルコアおよびリアクトル |
JP4524805B1 (ja) * | 2009-03-25 | 2010-08-18 | 住友電気工業株式会社 | リアクトル |
JP2010272772A (ja) | 2009-05-22 | 2010-12-02 | Sumitomo Electric Ind Ltd | リアクトル |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3566323A (en) * | 1969-05-01 | 1971-02-23 | Arnold Eng Co | C-shaped magnetizable core |
JPH07110438B2 (ja) | 1991-07-01 | 1995-11-29 | 株式会社ヨシツカ精機 | 粉末成形プレスの加圧制御方法及び装置 |
JPH0536546A (ja) * | 1991-07-26 | 1993-02-12 | Tdk Corp | トランス用コア及びその製法 |
WO2005107038A1 (ja) * | 2004-04-30 | 2005-11-10 | Sumitomo Electric Industries, Ltd. | 圧粉磁心およびその製造方法 |
WO2007132558A1 (ja) * | 2006-05-11 | 2007-11-22 | Tamura Corporation | コイル及びコイルの成形方法 |
DE112008000364B4 (de) * | 2007-02-05 | 2022-10-27 | Tamura Corp. | Spule und Verfahren zum Bilden der Spule |
WO2009107633A1 (ja) * | 2008-02-29 | 2009-09-03 | 株式会社タムラ製作所 | 連結コイル形成装置および連結コイルの形成方法 |
JP4465635B2 (ja) * | 2008-03-17 | 2010-05-19 | トヨタ自動車株式会社 | リアクトル装置 |
CN102132365B (zh) * | 2008-08-22 | 2015-09-09 | 住友电气工业株式会社 | 电抗器用部件以及电抗器 |
JP5459120B2 (ja) * | 2009-07-31 | 2014-04-02 | 住友電気工業株式会社 | リアクトル、リアクトル用部品、及びコンバータ |
-
2011
- 2011-08-23 JP JP2011181631A patent/JP5096605B2/ja active Active
-
2012
- 2012-02-09 US US13/812,997 patent/US8922323B2/en active Active
- 2012-02-09 WO PCT/JP2012/052942 patent/WO2012132565A1/ja active Application Filing
- 2012-02-09 EP EP12765517.3A patent/EP2587501B1/en active Active
- 2012-02-09 CN CN201280002197.1A patent/CN103038843B/zh active Active
- 2012-02-09 KR KR1020137002440A patent/KR101418690B1/ko active IP Right Grant
- 2012-02-09 MY MYPI2013700154A patent/MY184994A/en unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04168201A (ja) * | 1990-10-31 | 1992-06-16 | Kobe Steel Ltd | セラミックス強化Al合金複合材料の製造方法 |
JP2000144211A (ja) * | 1998-11-06 | 2000-05-26 | Toshiba Tungaloy Co Ltd | 粉末成形用の金型及び圧粉体の成形方法並びに切削用のポジチップ |
JP2008160020A (ja) * | 2006-12-26 | 2008-07-10 | Toyota Motor Corp | リアクトルコアおよびリアクトル |
JP4524805B1 (ja) * | 2009-03-25 | 2010-08-18 | 住友電気工業株式会社 | リアクトル |
JP2010272772A (ja) | 2009-05-22 | 2010-12-02 | Sumitomo Electric Ind Ltd | リアクトル |
Non-Patent Citations (1)
Title |
---|
See also references of EP2587501A4 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140375413A1 (en) * | 2013-06-21 | 2014-12-25 | Samsung Electro-Mechanics Co., Ltd. | Metal magnetic powder and method for forming the same, and inductor manufactured using the metal magnetic powder |
US9524817B2 (en) * | 2013-06-21 | 2016-12-20 | Samsung Electro-Mechanics Co., Ltd. | Metal magnetic powder and method for forming the same, and inductor manufactured using the metal magnetic powder |
Also Published As
Publication number | Publication date |
---|---|
EP2587501A4 (en) | 2013-08-28 |
EP2587501A1 (en) | 2013-05-01 |
CN103038843B (zh) | 2015-06-10 |
MY184994A (en) | 2021-04-30 |
JP5096605B2 (ja) | 2012-12-12 |
EP2587501B1 (en) | 2015-04-08 |
US8922323B2 (en) | 2014-12-30 |
JP2012216746A (ja) | 2012-11-08 |
KR101418690B1 (ko) | 2014-07-10 |
KR20130033424A (ko) | 2013-04-03 |
US20130127574A1 (en) | 2013-05-23 |
CN103038843A (zh) | 2013-04-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5096605B2 (ja) | 外側コアの製造方法、外側コア、およびリアクトル | |
JP5032690B1 (ja) | 圧粉成形体 | |
JP5027945B1 (ja) | 圧粉成形体、圧粉成形体の製造方法、リアクトル、コンバータ、及び電力変換装置 | |
US10340080B2 (en) | Method of manufacturing a green compact | |
WO2016043025A1 (ja) | 複合材料、磁気部品、及びリアクトル | |
JP5965190B2 (ja) | 圧粉成形体の製造方法、及び圧粉成形体 | |
JP5922887B2 (ja) | 圧粉成形体の製造方法、圧粉成形体、及びリアクトル | |
JP5831941B2 (ja) | 外側コアの製造方法 | |
JP5845022B2 (ja) | 磁気回路部品 | |
JP5845141B2 (ja) | 圧粉成形体、リアクトル用コア、及び磁気回路部品 | |
JP2013131676A (ja) | 圧粉成形体、リアクトル用コア、リアクトル、コンバータ、及び電力変換装置 | |
JP2012199568A (ja) | 圧粉成形体、圧粉成形体の製造方法、リアクトル、コンバータ、及び電力変換装置 | |
JP6174954B2 (ja) | 圧粉成形体の製造方法 | |
JP6295533B2 (ja) | リアクトル及びその製造方法 | |
WO2012147487A1 (ja) | 圧粉成形体の製造方法、圧粉成形体、リアクトル、コンバータおよび電力変換装置 | |
JP2013038132A (ja) | 磁気回路部品 | |
JP2023125565A (ja) | 圧粉成形体、圧粉磁心、圧粉成形体及び圧粉磁心の製造方法 | |
JP2012243912A (ja) | 圧粉成形体の製造方法、および圧粉成形体 | |
JP2017063113A (ja) | 複合材料成形体、及びリアクトル | |
JP2013016656A (ja) | 圧粉成形体の製造方法、および圧粉成形体 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201280002197.1 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12765517 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012765517 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 20137002440 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13812997 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |