US3416191A - Apparatus for compacting permanent magnet powders into pressings - Google Patents

Apparatus for compacting permanent magnet powders into pressings Download PDF

Info

Publication number
US3416191A
US3416191A US533899A US53389966A US3416191A US 3416191 A US3416191 A US 3416191A US 533899 A US533899 A US 533899A US 53389966 A US53389966 A US 53389966A US 3416191 A US3416191 A US 3416191A
Authority
US
United States
Prior art keywords
die
powder
permanent magnet
pressings
pressing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US533899A
Inventor
Richter Henning
Buttner Karl Heinz
Bintzek Gerhard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsche Edelstahlwerke AG
Original Assignee
Deutsche Edelstahlwerke AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deutsche Edelstahlwerke AG filed Critical Deutsche Edelstahlwerke AG
Application granted granted Critical
Publication of US3416191A publication Critical patent/US3416191A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • H01F41/0253—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 for manufacturing permanent magnets
    • H01F41/0273—Imparting anisotropy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/008—Applying a magnetic field to the material
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S425/00—Plastic article or earthenware shaping or treating: apparatus
    • Y10S425/033—Magnet

Definitions

  • the conventional procedure consists in mixing strontium carbonate and Fe O powder in the proportion of about 1:4, sintering the mixture at a suitable temperature for the purpose of forming the mixed ferrite crystal, crushing and finally milling the ferrite material to a fineness under 51.4.
  • This fine-ground ferrite powder is then magnetically orientated in presses by the application of a magnetic field, pressed to the desired magnet shape and finally sintered to completion.
  • the present invention relates to the pressing of the powder in a magnetic field.
  • the ferrite powder is filled into dies either in the dry form or in the form of a watery slurry and pressed whilst exposed to a magnetic field in the direction in which the magnet is to be preferentially orientated.
  • the direction of the magnetic field may be parallel to or across the pressing direction, permitting the preferential direction of magnetisation of the discs, rings or like to be either axial or parallel to a diameter.
  • the object of the present invention to provide an apparatus in which the drawbacks of conventional 'arrangements are overcome and in which cross magnetisation can be performed even if the powder is magnetically sucked into the die.
  • the problem is solved by providing a die and a magnet coil which are relatively axially displaceable for drawing the powder into the die and a pair of magnet coils for generating the field for diametrically orientating the powder, with poleshoes movable in the radial direction, i.e., normal to the axis of the pressing tool.
  • This form of construction permits the latter pair of poleshoes to be withdrawn from the zone of the magnetic suction field whilst the powder is being drawn into the die, so that this process is not interfered with.
  • the poleshoes are arranged to be movable into contiguous adjacence with a die which is made of a nonmagnetisable material and to this end they are axially movable inside the magnet coils which embrace them.
  • the magnetic field for diametrically orientating the powder may, if desired, be generated by permanent magnets.
  • FIG. 1a is a sectional elevation showing the apparatus ready for drawing the material into the die
  • FIG. 2a is a sectional elevation showing the die as having risen from the position shown in FIG. 1a and the material drawn thereinto
  • FIG. 3a is a similar elevation showing the poleshoes in a position for producing the transverse magnetisation
  • FIG. 4a illustrates the pressing operation after transverse magnetisation.
  • the figures whose numbers are provided with index a are all axial sections, whereas those provided with index b are the corresponding plan views.
  • FIGS. 10/ lb show the pressing tool in the position it occupies before the filling operation begins.
  • the punch 1 which consists of or the head portion of which is of a nonmagnetisable material is in its normal position of rest. In this position the bottom punch 2 and the upper edge of the suction coil 4 may be brought flush with the upper edge of the nonmagnetisable die 3.
  • the feeding shoe 6 containing the charge of ferrite powder is directly above the centre of the die.
  • the poleshoes 5, 5' of the diametrically orientating pair of coils 7, 7' are retracted from the die sufiiciently to be out of contact with the suction coil 4 and not to interfere with the suction field.
  • FIG. 10/ lb show the pressing tool in the position it occupies before the filling operation begins.
  • the field coil 4 for generating the suction is energised whilst the die rises, the coil 4 and the lower punch 2 remaining stationary in its position. Because of this relative motion the suction coil will become disposed away from the upper edge of the die and draws in the powder.
  • FIG. 2a shows the filling process completed.
  • the die has been filled with powder and the magnetic field of coil 4is therefore switched otf.
  • FIG. 3a the feeding shoe has been removed.
  • Suitable devices which for the sake of greater clarity are not shown in the drawing now advance the poleshoes 5, 5' through or with the coils 7, 7' into position for applying the field for diametrically orientating the ferrite powder inside the cavity of the die. In this position the poleshoes are substantially in direct contact with the die. Consequently the field which arises when the coils are energised is particularly intense.
  • FIGS. 4a and b show the manner in which the powder, after orientation in the direction normal to pressing direction, is compressed.
  • the proposed arrangement by using suitably shaped dies, which may be dished, annular or bar-shaped, and which may be ditficult to fill when the wall sections of the pressings are thin, is capable of conveniently pressing the magnet bodies in continuous production by drawing the powder into the die in conventional manner by magnetic suction and nevertheless magnetically orientating the pressings in the diametral direction, i.e. across the pressing direction.
  • the arrangement is principally envisaged for use in the processing of ferrite powder. However, in principle the arrangement would be as readily applicable to the processing of other powdered permanent magnet materials.
  • Apparatus for compacting permanent magnet powders into pressing magnetised diametrically across the pressing direction in a die into which the powder is introduced by magnetic suction comprising the die and a magnet coil which are relatively movable in the axial direction of the die for drawing the powder into the die

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Powder Metallurgy (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)
  • Press-Shaping Or Shaping Using Conveyers (AREA)

Description

Dec. 17, 1968 H. RICHTER ETAL 3,416,191
APPARATUS FOR COMPACTING PERMANENT MAGNET POWDEHS INTO PRESSINGS Filed March 14, 1966 4 Sheets-Sheet 1 7 5' a ooooo o o o 0 000000 OOOOOOO 1968 H. RICHTER ETAL 3,
APPARATUS FOR COMPACTING PERMANENT MAGNET POWDERS INTO PRESSINGS Filed March 14, 1966 4 Sheets-Sheet 2 7 5' 6 5 7 I JOOOOOO 6 OOOJOOO 0000000 l ooooooo Fig. 212
1968 H. RICHTER ETAL 3,416,191
APPARATUS FOR COMPACTING PERMANENT MAGNET P OWDERS INTO PRESSINGS Filed March 14, 1966 4 Sheets-Sheet 5 7' 5' 5 7 OOOOJOOOOOjJO 0000040000 7' 5 0 5 7 0(000000900 I OOOJADOOOOOO Fig. 3 b
' In nt0rs Dec. 17, 1968 H. RICHTER ETAL APPARATUS FOR COMPACTING PERMANENT MAGNET POWDERS INTO PRESSINGS 4 Sheets -Sheet 4.
Filed March 14. 1966 O OOOOOOOOOOO Fig. [111 5 7 /AOOOOOOOOO OOOOOOOOOOOO 7! OKOOOOOOLOOO OOOOOOOOOOOO Fig. 11 b United States Patent Oflice Patented Dec. 17, 1968 3 Claims. (Cl. 18-16.5)
For the production of magnet bodies made of barium or strontium ferrite with a preferred direction of magnetisation, the conventional procedure consists in mixing strontium carbonate and Fe O powder in the proportion of about 1:4, sintering the mixture at a suitable temperature for the purpose of forming the mixed ferrite crystal, crushing and finally milling the ferrite material to a fineness under 51.4. This fine-ground ferrite powder is then magnetically orientated in presses by the application of a magnetic field, pressed to the desired magnet shape and finally sintered to completion.
The present invention relates to the pressing of the powder in a magnetic field. As known, the ferrite powder is filled into dies either in the dry form or in the form of a watery slurry and pressed whilst exposed to a magnetic field in the direction in which the magnet is to be preferentially orientated. When pressing a liquid material the liquid is withdrawn from the slurry during this process. The direction of the magnetic field may be parallel to or across the pressing direction, permitting the preferential direction of magnetisation of the discs, rings or like to be either axial or parallel to a diameter.
It has also been proposed, besides orientating the powder, to use the magnetic field for magnetically sucking the dry powder or slurry into the cavity of the die by making use of the inhomogeneity of the magnetic field. When this is done orientation in the crosswise direction cannot be performed directly after magnetically drawing the powder into the die in pressing direction because the magnetic field between the poleshoes of diametrically disposed magnet coils which would have to be located above the magnet coil required for creating the suction, would naturally interfere with the suction field and it would therefore be impossible to suck the ferrite powder magnetically into the die.
It is the object of the present invention to provide an apparatus in which the drawbacks of conventional 'arrangements are overcome and in which cross magnetisation can be performed even if the powder is magnetically sucked into the die. According to the invention the problem is solved by providing a die and a magnet coil which are relatively axially displaceable for drawing the powder into the die and a pair of magnet coils for generating the field for diametrically orientating the powder, with poleshoes movable in the radial direction, i.e., normal to the axis of the pressing tool. This form of construction permits the latter pair of poleshoes to be withdrawn from the zone of the magnetic suction field whilst the powder is being drawn into the die, so that this process is not interfered with. Conveniently, the poleshoes are arranged to be movable into contiguous adjacence with a die which is made of a nonmagnetisable material and to this end they are axially movable inside the magnet coils which embrace them. Alternatively, the magnetic field for diametrically orientating the powder may, if desired, be generated by permanent magnets.
The manner in which the proposed arrangement functions is illustratively shown in more or less schematic form in the drawings. In the drawings, FIG. 1a is a sectional elevation showing the apparatus ready for drawing the material into the die, FIG. 2a is a sectional elevation showing the die as having risen from the position shown in FIG. 1a and the material drawn thereinto; FIG. 3a is a similar elevation showing the poleshoes in a position for producing the transverse magnetisation; and FIG. 4a illustrates the pressing operation after transverse magnetisation. The figures whose numbers are provided with index a are all axial sections, whereas those provided with index b are the corresponding plan views.
FIGS. 10/ lb show the pressing tool in the position it occupies before the filling operation begins. The punch 1 which consists of or the head portion of which is of a nonmagnetisable material is in its normal position of rest. In this position the bottom punch 2 and the upper edge of the suction coil 4 may be brought flush with the upper edge of the nonmagnetisable die 3. The feeding shoe 6 containing the charge of ferrite powder is directly above the centre of the die. The poleshoes 5, 5' of the diametrically orientating pair of coils 7, 7' are retracted from the die sufiiciently to be out of contact with the suction coil 4 and not to interfere with the suction field. In the position of the pressing tool illustrated in FIG. la the field coil 4 for generating the suction is energised whilst the die rises, the coil 4 and the lower punch 2 remaining stationary in its position. Because of this relative motion the suction coil will become disposed away from the upper edge of the die and draws in the powder.
FIG. 2a shows the filling process completed. The die has been filled with powder and the magnetic field of coil 4is therefore switched otf.
In FIG. 3a the feeding shoe has been removed. Suitable devices which for the sake of greater clarity are not shown in the drawing now advance the poleshoes 5, 5' through or with the coils 7, 7' into position for applying the field for diametrically orientating the ferrite powder inside the cavity of the die. In this position the poleshoes are substantially in direct contact with the die. Consequently the field which arises when the coils are energised is particularly intense.
FIGS. 4a and b show the manner in which the powder, after orientation in the direction normal to pressing direction, is compressed.
It will therefore be seen that the proposed arrangement, by using suitably shaped dies, which may be dished, annular or bar-shaped, and which may be ditficult to fill when the wall sections of the pressings are thin, is capable of conveniently pressing the magnet bodies in continuous production by drawing the powder into the die in conventional manner by magnetic suction and nevertheless magnetically orientating the pressings in the diametral direction, i.e. across the pressing direction. The arrangement is principally envisaged for use in the processing of ferrite powder. However, in principle the arrangement would be as readily applicable to the processing of other powdered permanent magnet materials.
What we claim is:
1. Apparatus for compacting permanent magnet powders into pressing magnetised diametrically across the pressing direction in a die into which the powder is introduced by magnetic suction, comprising the die and a magnet coil which are relatively movable in the axial direction of the die for drawing the powder into the die References Cited UNITED STATES PATENTS 2,959,823 11/1960 Schwable et a1. 264-24 I. HOWARD FLINT,
4 Falk et a1. 1816.5 X
Gordon 264--24 Biittner et a1.
Quinn 18-16 Miiller 18--16.5 X
JR., Primary Examiner.
US. Cl. X.R.

Claims (1)

1. APPARATUS FOR COMPACTING PERMANENT MAGNET POWDERS INTO PRESSING MAGNETISED DIAMETRICALLY ACROSS THE PRESSING DIRECTION IN A DIE INTO WHICH THE POWDER IS INTRODUCED BY MAGNETIC SUCTION, COMPRISING THE DIE AND A MAGNET COIL WHICH ARE RELATIVELY MOVABLE IN THE AXIAL DIRECTION OF THE DIE FOR DRAWING THE POWDER INTO THE DIE AND A PAIR OF MAGNET COILS WITH POLESHOES MOVEABLE CROSS-
US533899A 1965-03-30 1966-03-14 Apparatus for compacting permanent magnet powders into pressings Expired - Lifetime US3416191A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DED0046932 1965-03-30

Publications (1)

Publication Number Publication Date
US3416191A true US3416191A (en) 1968-12-17

Family

ID=7050059

Family Applications (1)

Application Number Title Priority Date Filing Date
US533899A Expired - Lifetime US3416191A (en) 1965-03-30 1966-03-14 Apparatus for compacting permanent magnet powders into pressings

Country Status (2)

Country Link
US (1) US3416191A (en)
FR (1) FR1462732A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3548455A (en) * 1967-08-03 1970-12-22 Reuter Inc Apparatus for direct conversion of powdered materials into parts
US3694115A (en) * 1967-11-09 1972-09-26 Magnetfab Bonn Gmbh Molding apparatus for making anisotropic ring-shaped magnets with zones having a preferred radial direction
US3901642A (en) * 1973-04-25 1975-08-26 Dso Mebel Apparatus for the production of pressure-shaped parts from oriented wood particles
US3906624A (en) * 1973-03-07 1975-09-23 Fuji Carbon Manufacturing Co L Electrical machine brush and method and apparatus for manufacturing the same
US4150927A (en) * 1976-07-03 1979-04-24 Magnetfabrik Bonn, GmbH vormals Gewerkschaft Windhorst Mold for the production of anisotropic permanent magnets
EP0393815A1 (en) * 1989-04-15 1990-10-24 Fuji Electrochemical Co.Ltd. Method for packing permanent magnet powder
US5560939A (en) * 1988-04-28 1996-10-01 Aida Engineering, Ltd. Mold assembly comprising a sliding mold insert adapted for automated insertion and removal
US5762967A (en) * 1995-04-18 1998-06-09 Intermetallics Co., Ltd. Rubber mold for producing powder compacts
US20070176329A1 (en) * 2006-02-01 2007-08-02 Tdk Corporation Magnetic field modling device, die and method for magnetic field molding

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2959823A (en) * 1958-12-24 1960-11-15 Deutsche Edelstahlwerke Ag Method of producing compressed parts for permanent magnets
US2999271A (en) * 1960-08-30 1961-09-12 Gen Electric Magnetic material
US3079639A (en) * 1960-11-30 1963-03-05 Rca Corp Method and apparatus for preparing magnetic cores
US3189667A (en) * 1960-11-23 1965-06-15 Deutsche Edelstahlwerke Ag Method of producing pressings to form permanent magnets
US3234598A (en) * 1962-09-24 1966-02-15 Indiana General Corp Apparatus for pressing slurries
US3274303A (en) * 1961-12-21 1966-09-20 Magnetfabrik Bonn Gewerkschaft Method and apparatus for making magnetically anisotropic permanent magnets

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2959823A (en) * 1958-12-24 1960-11-15 Deutsche Edelstahlwerke Ag Method of producing compressed parts for permanent magnets
US2999271A (en) * 1960-08-30 1961-09-12 Gen Electric Magnetic material
US3189667A (en) * 1960-11-23 1965-06-15 Deutsche Edelstahlwerke Ag Method of producing pressings to form permanent magnets
US3079639A (en) * 1960-11-30 1963-03-05 Rca Corp Method and apparatus for preparing magnetic cores
US3274303A (en) * 1961-12-21 1966-09-20 Magnetfabrik Bonn Gewerkschaft Method and apparatus for making magnetically anisotropic permanent magnets
US3234598A (en) * 1962-09-24 1966-02-15 Indiana General Corp Apparatus for pressing slurries

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3548455A (en) * 1967-08-03 1970-12-22 Reuter Inc Apparatus for direct conversion of powdered materials into parts
US3694115A (en) * 1967-11-09 1972-09-26 Magnetfab Bonn Gmbh Molding apparatus for making anisotropic ring-shaped magnets with zones having a preferred radial direction
US3906624A (en) * 1973-03-07 1975-09-23 Fuji Carbon Manufacturing Co L Electrical machine brush and method and apparatus for manufacturing the same
US3901642A (en) * 1973-04-25 1975-08-26 Dso Mebel Apparatus for the production of pressure-shaped parts from oriented wood particles
US4150927A (en) * 1976-07-03 1979-04-24 Magnetfabrik Bonn, GmbH vormals Gewerkschaft Windhorst Mold for the production of anisotropic permanent magnets
US5560939A (en) * 1988-04-28 1996-10-01 Aida Engineering, Ltd. Mold assembly comprising a sliding mold insert adapted for automated insertion and removal
EP0393815A1 (en) * 1989-04-15 1990-10-24 Fuji Electrochemical Co.Ltd. Method for packing permanent magnet powder
US5762967A (en) * 1995-04-18 1998-06-09 Intermetallics Co., Ltd. Rubber mold for producing powder compacts
US20070176329A1 (en) * 2006-02-01 2007-08-02 Tdk Corporation Magnetic field modling device, die and method for magnetic field molding

Also Published As

Publication number Publication date
FR1462732A (en) 1966-12-16

Similar Documents

Publication Publication Date Title
US5250255A (en) Method for producing permanent magnet and sintered compact and production apparatus for making green compacts
US5672363A (en) Production apparatus for making green compact
US3416191A (en) Apparatus for compacting permanent magnet powders into pressings
US2569226A (en) Method of producing articles from powdered material
US3555621A (en) Compacting apparatus for magnetic powders
US3085291A (en) Device for manufacturing magnetically anisotropic bodies
US3274303A (en) Method and apparatus for making magnetically anisotropic permanent magnets
US3694115A (en) Molding apparatus for making anisotropic ring-shaped magnets with zones having a preferred radial direction
JPH0696973A (en) Production of permanent magnet
US3671157A (en) Die and punch assembly for compacting powder material
US2996759A (en) Method of and apparatus for manufacturing compressed articles
JPH0543904A (en) Production of permanent magnet green compact
JP3425731B2 (en) Method and apparatus for forming a green compact
US3189667A (en) Method of producing pressings to form permanent magnets
US2959823A (en) Method of producing compressed parts for permanent magnets
US3469283A (en) Powder hopper for powder compacting press
US4147489A (en) Powder compacting presses
JPH0313281B2 (en)
US3277524A (en) Method of and apparatus for compacting ferrite particles
JP2539481B2 (en) METHOD FOR SUPPLYING MATERIAL POWDER TO METAL FOR PRESS FORMING RING-TYPE PARTS AND MATERIAL POWDER SUPPLY DEVICE USED FOR THE SAME
SU1509178A1 (en) Device for compacting powder anisotropic magnets
CN108326291A (en) A kind of preparation method of large scale material
JPH0646972Y2 (en) Magnetic field press equipment
JPH0737641B2 (en) Powder molding method for magnetic metal tube
JPS61137700A (en) Rotary press forming device