US20020028643A1 - Ferrite core for deflecting yoke, surface polishing apparatus and grindstone therefor - Google Patents

Ferrite core for deflecting yoke, surface polishing apparatus and grindstone therefor Download PDF

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Publication number
US20020028643A1
US20020028643A1 US09/945,813 US94581301A US2002028643A1 US 20020028643 A1 US20020028643 A1 US 20020028643A1 US 94581301 A US94581301 A US 94581301A US 2002028643 A1 US2002028643 A1 US 2002028643A1
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United States
Prior art keywords
ferrite core
grindstone
wall surface
end portion
grinding
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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.)
Abandoned
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US09/945,813
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English (en)
Inventor
Hitoshi Iwaya
Minoru Anbo
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TDK Corp
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TDK Corp
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Abandoned legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/236—Manufacture of magnetic deflecting devices for cathode-ray tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
    • B24B5/02—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centres or chucks for holding work
    • B24B5/06—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centres or chucks for holding work for grinding cylindrical surfaces internally

Definitions

  • the present invention relates to a surface polishing apparatus which, when manufacturing a ferrite core for a deflecting yoke for deflecting the electronic beam of a cathode-ray tube, polishes the surface of the ferrite core to thereby finish it into a given shape, and a ferrite core polished by such a surface polishing apparatus.
  • a cathode-ray tube which is used in a color television or a display monitor, is required to show high-grade image quality and, in order to be able to obtain high resolving power, it is also required to enhance the position accuracy of an electronic beam which is deflected.
  • Such high-grade image quality and electronic beam position accuracy greatly depend on the characteristic of a core for a deflecting yoke and, as the material of such core, there is conventionally used ferrite.
  • the ferrite core is manufactured by firing ferrite material powder after it is molded; and, in the case where the ferrite material is fired after it is molded, due to the thermal shrinkage thereof, the volume thereof is reduced by approximately 60%. For this reason, in order to make uniform the dimensions of the ferrite cores, the ferrite cores must be ground and polished after they are fired.
  • FIG. 9(A) is a section view of a ferrite core 1 for a deflecting yoke, showing a state in which a grindstone 3 is inserted into a center hole 1 a formed in the ferrite core 1 and the inner wall surface 1 b of the center hole 1 a is polished by the grindstone 3 .
  • the ferrite core 1 and the grindstone 3 can be respectively driven and rotated by electric motors which are disposed on the respective rotary shafts of the ferrite core 1 and the grindstone 3 .
  • These two rotary shafts are arranged in parallel to each other; and, an operation to polish the inner wall surface 1 b of the ferrite core 1 is executed in such a manner that, the ferrite core 1 and the grindstone 3 are both rotated, the distance between the two rotary shafts are caused to vary while maintaining their parallel relationship, and the center hole la is polished while the outside of the grindstone 3 is contacted with the inner wall surface 1 b.
  • It is an object of the invention to provide a surface polishing apparatus which, in a process for manufacturing a ferrite core for a deflecting yoke, by using a grindstone formed as an integral body so as to be simultaneously contactable with the inner and outer wall surfaces of the ferrite core for a deflecting yoke, can enhance the working accuracy of the ferrite core without making the polishing operation complicated, can realize reduction in the time necessary for polishing the ferrite core, and can finish accurately the outer wall surface of the ferrite core for a deflecting yoke and the inner wall surface of the central hole of the ferrite core into their given shapes.
  • securing means for securing the upper end portion of the ferrite core, holding means for holding the grindstone, and means for contacting the grindstone with the lower end portion of the ferrite core and for driving and rotating the securing means and/or holding means.
  • the pillar-shaped projecting portion of the grindstone increasing in diameter from the upper end portion thereof to the lower end portion thereof, the disk-shaped seat surface portion of the grindstone connecting together the lower end portions of the pillar-shaped projecting portion, and the outer periphery projecting portion of the grindstone provided on the outer peripheral surface of the disk-shaped seat surface portion and projected therefrom in the periphery of the pillar-shaped projecting portion are formed integral with one another.
  • a sixth aspect of the invention in a grindstone as set forth in the third to fifth aspects of the invention, there are formed a plurality of spiral-shaped groove portions in the side surface of the pillar-shaped projecting portion.
  • a substantially trumpet-shaped ferrite core for a deflecting yoke having a diameter increasing from the upper end portion thereof to the lower end portion thereof, wherein the inner wall surface of the hole portion and the outer wall surface of the lower end portion of the ferrite core are polished simultaneously using a grindstone whose grinding surfaces to be respectively contacted with the inner wall surface of the hole portion and the outer wall surface of the lower end portion of the ferrite core are formed integral with each other.
  • the inner wall surface of the hole portion and the outer wall surface of the lower end portion of the ferrite core have a coaxiality deviation of 0.03 mm or less.
  • FIG. 1 is a perspective view of a ferrite core for a deflecting yoke to be polished by a surface polishing apparatus according to the invention.
  • FIG. 2 is a perspective view of a grindstone according to a first embodiment of the invention, showing the shape of the grindstone.
  • FIGS. 3 (A) and 3 (B) are schematic views of the shape of the grindstone according to the first embodiment.
  • FIG. 4 is a schematic view of the structure of a surface polishing apparatus according to the first embodiment of the invention.
  • FIGS. 5 (A) and 5 (B) are section views of the surface polishing apparatus according to the first embodiment, showing the polishing state thereof.
  • FIG. 6 is a section view of the surface polishing apparatus according to the first embodiment, showing the polishing state thereof.
  • FIG. 7 is a perspective view of a grindstone according to a second embodiment of the invention.
  • FIGS. 8 (A) and 8 (B) are schematic views of a grindstone according to a third embodiment of the invention.
  • FIGS. 9 (A) and 9 (B) are explanatory views of a polishing operation to be executed when a conventional polishing apparatus is used.
  • FIG. 10 is an explanatory view of a polishing operation to be executed when a conventional polishing apparatus is used.
  • FIG. 11 is a table to show the coaxiality deviation of a ferrite core polished by a grindstone according to the invention.
  • FIG. 1 is a perspective view of a ferrite core 1 for a deflecting yoke.
  • the ferrite core 1 includes a small-diameter portion 1 d in one end portion (upper end portion) thereof and a large-diameter portion 1 e in the other end portion (lower end portion) thereof.
  • the ferrite core 1 further includes a connecting portion if the outer wall of which gradually increases in size from the small-diameter portion 1 d to the large-diameter portion 1 e and also which connects together the small-diameter portion 1 d and the large-diameter portion 1 e smoothly; and, the small-diameter portion 1 d , large-diameter portion 1 e and connecting portion if are formed of ferrite material as an integral body.
  • there is formed a center hole la so as to penetrate through the small-diameter portion 1 d and large-diameter portion 1 e .
  • the inside diameter of the center hole 1 a gradually increases from the small-diameter portion 1 d toward the large-diameter portion 1 e ; and thus, the center hole 1 a is formed as a smooth three-dimensional curved surface substantially like a trumpet shape.
  • the ferrite material there are used Mg—Mn—Zn system material and Mn—Zn system material.
  • a ferrite core is manufactured of the powder of such ferrite material through the following steps: that is, (1) the step of measuring the weight of the ferrite material powder; (2) the step of mixing the ferrite material powder; (3) the step of granulating the mixture; (4) the step of calcining the granulated ferrite material; (5) the step of grinding the calcined ferrite material; (6) the step of granulating the ground ferrite material; (7) the step of molding the granulated ferrite material; (8) the step of firing the molded ferrite material; (9) the step of finishing the fired ferrite material into a finish ferrite core; and, the step of warehousing the finish ferrite core.
  • the ferrite cores vary from one another in dimension and shape, so that the deflecting characteristics of cathode-ray tubes are caused to vary greatly from one another.
  • a grinding operation and a polishing operation must be executed.
  • the outer wall surface 1 c (and bottom wall surface 1 g ) of the large-diameter portion 1 e (lower end portion) of the ferrite core 1 and the inner wall surface 1 b of the center hole la are ground and polished simultaneously.
  • the length of this linear portion is set in the range between ⁇ fraction (1/10) ⁇ and 1 ⁇ 2 of the height of the ferrite core 1 (the distance from the upper end portion, that is, small-diameter portion id to the lower end portion, that is, large-diameter portion 1 e ).
  • FIGS. 2 and 3 are explanatory views of the shape of a grindstone 2 used in the invention. Specifically, FIG. 2 is a perspective view of the grindstone 2 ; FIG. 3(A) is a plan view of the grindstone 2 ; and, FIG. 3(B) is a longitudinal section view of the grindstone 2 .
  • the grindstone 2 comprises a disk-shaped bottom end portion 2 c forming a disk-shaped seat surface, an outer periphery projecting portion 2 d formed on the outer periphery of the bottom end portion 2 c , and a pillar-shaped projecting portion 2 e provided on and projected long upwardly from the central portion of the bottom end portion 2 c ; and, these portions 2 c , 2 d and 2 e are formed as an integral body.
  • the inner wall surface of the outer periphery projecting portion 2 d provides a grinding surface 2 a for grinding or polishing the outer wall surface 1 c of the ferrite core 1
  • the outer periphery of the pillar-shaped projecting portion 2 e (the portion corresponding to the pillar side surface) provides a grinding surface 2 b for grinding or polishing the inner wall surface 1 b of the ferrite core 1
  • the bottom end portion 2 c , pillar-shaped projecting portion 2 e and outer periphery projecting portion 2 d are concentric with one another, while the outer periphery projecting portion 2 d encloses the periphery of the pillar-shaped projecting portion 2 e .
  • the outside diameter of the upper end face 2 f is set smaller than the diameter of the center hole 1 a on the small-diameter portion 1 d side of the ferrite core 1 , while the outside diameter of the pillar-shaped projecting portion 2 e increases gradually toward the bottom end portion 2 c . As shown in FIG.
  • the section surface of the grinding surface 2 b of the pillar-shaped projecting portion 2 e provides a smooth curved line; and, this curved line is similar in shape to the diameter of the center hole 1 a which gradually increases from the small-diameter portion 1 d of the ferrite core 1 toward the large-diameter portion 1 e thereof.
  • the inside diameter of the grinding surface 2 a which is the inner wall surface of the outer periphery projecting portion 2 d is set larger than the outside diameter of the large-diameter portion 1 e of the ferrite core 1 .
  • FIG. 4 is a schematic view of the first embodiment of a surface polishing apparatus according to the invention, including a section view thereof, in which the small-diameter portion 1 d of the ferrite core 1 for a deflecting yoke is secured to securing means 10 , while the grindstone 2 is contacted with the ferrite core 1 so that the former is be able to polish the latter. Also, in FIG. 4, the ferrite core 1 , grindstone 2 and securing means 10 are shown sectionally.
  • the grindstone 2 is mounted on the rotary shaft 5 a of an electric motor 5 , while the electric motor 5 drives and rotates the grindstone 2 in such a manner that the grindstone 2 is prevented from being eccentric with respect to the rotary shaft 5 a .
  • the securing means 10 is mounted on the rotary shaft 11 a of an electric motor 11 , while the electric motor 11 drives and rotates the securing means 10 in such a manner that the securing means 11 is prevented from being eccentric with respect to the rotary shaft 11 a .
  • XX′ designates the rotation axis of the ferrite core 1 secured to the securing means 10
  • YY′ stands for the rotation axis of the grindstone 2 .
  • Both or one of the ferrite core 1 and grindstone 2 are or is rotated and thus they are contacted with each other to thereby polish the ferrite core 1 in such a manner that the distance between the two rotational axes XX′, YY′ are caused to vary while maintaining them in parallel to each other.
  • the grindstone 2 is held by holding means 12 together with the electric motor 5 or in such a manner that it is connected with the electric motor 5 by transmission means (not shown) for transmission of the rotational driving motion of the electric motor 5 .
  • the holding means 12 while holding the grindstone 2 , can be moved from a position, where the grindstone 2 can be contacted with the ferrite core 1 secured to the securing means 10 , to a position where the grindstone 2 can be separated from the ferrite core 1 .
  • the holding means 12 includes moving means 12 a which moves the grindstone 2 to thereby adjust its distance and contact positions with respect to the ferrite core 1 according to the progress of the grinding operation.
  • the moving means 12 a includes a dial meter for grasping the moving distance of the grindstone 2 that is moved according to the progress of the grinding operation. Holding by the holding means 12 is to keep the parallel relationship between the rotation axis YY′ of the grindstone 2 and the rotation axis XX′ of the ferrite core 1 ; and, in the fine adjustment of the grindstone 2 by the moving means 12 a as well, the parallel relationship between these two rotation axes are maintained.
  • the holding means 12 and 13 are respectively disposed on a base 14 in such a manner that the rotation axis XX′ and rotation axis YY′ can be aligned with each other or can be adjusted into alignment with each other.
  • the rotation axis XX′ is the rotation axis of the ferrite core 1 secured to the securing means 10 and the rotation axis YY′ is the rotation axis of the grindstone 2 .
  • the rotation axes (rotation centers) of the electric motors 5 and 11 are respectively the same as the rotation axes XX′ and YY′.
  • transmission means not shown
  • the electric motors 5 and 11 may also be held at other positions and other types of holding means may also be employed.
  • the securing means 10 secures the ferrite core 1 in such a manner that the outer periphery of the small-diameter portion 1 d of the ferrite core 1 is held from a plurality of directions by the securing portion 10 b.
  • the polishing operation is carried out by rotating both or one of the ferrite core 1 and grindstone 2 .
  • the rotation speed of the ferrite core 1 should be slower than the rotation speed of the grindstone 2 . Because the ferrite core 1 must be ground and polished so as to have given shape and dimensions, the ferrite core 1 is rotated in such a manner that it is always fixed at a given position; and, the grindstone 2 is moved with respect to the ferrite core 1 .
  • the moving means 12 a Before polishing of the ferrite core 1 is started, in the moving means 12 a , there is previously set a reference position in which, for example, the rotation axes XX′ and YY′ can be aligned with each other; and, when the grindstone 2 is moved as the polishing operation progresses, the movement quantities of the grindstone 2 from the reference position is electrically or mechanically read by the dial meter of the moving means 12 a respectively as the movement quantity in the rotation axis direction and the movement quantity in the vertical direction.
  • the moving means 12 a is controlled by an operator to move the grindstone 2 , or in the case of an automatic operation (such as a microcomputer-controlled operation), the moving means 12 a is controlled by an electric signal representing the movement quantities to move the grindstone 2 , thereby grinding and polishing the ferrite core 1 so as to produce given shape and dimensions, with the result that there can be produced a core for a deflecting yoke.
  • the polishing operation of the ferrite core 1 is executed in the following manner.
  • the grinding surface 2 b of the grindstone 2 is contacted with the inner wall surface 1 b of the ferrite core 1 and, at the same time, the grinding surface 2 a of the outer peripheral projecting portion 2 d is contacted with the outer wall surface 1 c of the ferrite core 1 ; that is, the polishing operation is executed in such contact manner.
  • the polishing operation there is a possibility that the grindstone 2 cannot be contacted with the ferrite core 1 depending on the shape and/or dimensions of the ferrite core 1 before it is polished.
  • the mutual distance between the rotation axis XX′ of the ferrite core 1 and the rotation axis YY′ of the grindstone 2 is adjusted in the vertical direction and, with the progress of the grinding and polishing operation, the grindstone 2 is moved so that the mutual distance can provide a given distance.
  • FIGS. 5 (A) and 5 (B) are section views of the ferrite core 1 and grindstone 2 at the time when the polishing operation is started.
  • the rotation axis XX′ of the ferrite core 1 and the rotation axis YY′ of the grindstone 2 are aligned with each other and, after then, the grindstone 2 is gradually moved to approach the ferrite core 1 from the large-diameter portion 1 e side of the ferrite core 1 , before the polishing operation is started.
  • the bottom wall surface 1 g of the ferrite core 1 is contacted with the grinding surface of the surface of the bottom end portion 2 c of the grindstone 2 and thus, firstly, the bottom wall surface 1 g of the ferrite core 1 is polished.
  • the grinding surface 2 a of the grindstone 2 is contacted with the outer wall surface 1 c of the ferrite core 1 and also the grinding surface 2 b of the pillar-shaped projecting portion 2 e of the grindstone 2 is contacted with the inner wall surface 1 b of the ferrite core 1 , so that the grindstone 2 polishes the inner wall surface 1 b and outer wall surface 1 c of the ferrite core 1 simultaneously.
  • the center hole 1 a and large-diameter portion 1 e of the ferrite core 1 can be polished to provide given shapes respectively.
  • the curved surface of the pillar-shaped projecting portion 2 e is polished in such a manner that the diameter of the center hole 1 a increases gradually from the small-diameter portion 1 d toward the large-diameter portion 1 e ; and, therefore, as described above, the inside diameter of the center hole 1 a can be finished into a smooth three-dimensional curved surface.
  • FIG. 7 is a perspective view of a grindstone 20 which is employed in the second embodiment of the invention.
  • the second embodiment is similar to the previously described first embodiment except that the grindstone 20 is different in shape from the grindstone 2 ; that is, the structure of the second embodiment and the polishing operation of the ferrite core 1 are similar to those previously discussed with reference to FIGS. 2 to 6 .
  • the grindstone 20 shown in FIG. 7 in the outer periphery projecting portion 2 d of the grindstone 2 shown in FIG.
  • each groove 20 g extends from a grinding surface 20 a , which is the inner wall surface of the outer periphery projecting portion 20 d of the grindstone 20 , and penetrates through the outer wall surface 20 h of the grindstone 20 ; and also, the groove 20 g has a depth substantially equivalent to the distance from the upper surface 20 i of the outer periphery projecting portion 20 d to the upper surface of the bottom end portion 20 c on which a pillar-shaped projecting portion 20 e is provided.
  • the invention is not limited to the structure shown in FIG. 7 but other structures are also possible; for example, the grooves 20 g may be formed in a spiral shape, or the number, shape and depth of grooves may be varied.
  • FIGS. 8 (A) and 8 (B) are schematic views of a grindstone 30 employed in the third embodiment.
  • the grindstone 30 shown in FIGS. 8 (A) and 8 (B) in the grinding surface of the pillar-shaped projecting portion of the grindstone 30 , there are formed spiral-shaped grooves 30 g .
  • FIG. 8 (A) and 8 (B) in the grinding surface of the pillar-shaped projecting portion of the grindstone 30 .
  • FIG. 8(A) is a plan view of the grindstone 30 , extending at right angles to the rotation axis YY′, and FIG. 8(B) is a perspective view of the grindstone 30 .
  • the grindstone 30 is the same in shape as the grindstone 2 shown in FIG. 2 and previously discussed in the first embodiment, except that it includes a plurality of grooves 30 g .
  • the third embodiment employs the same structure and polishing operation of the core 1 as those previously described with reference to FIGS. 2 to 7 .
  • Each of the grooves 30 g formed in the grindstone 30 shown in FIGS. 8 (A) and (B) starts at the outer periphery of the upper end face 30 f of the grindstone 30 , extends through the grinding surface 30 b of the pillar-shaped projecting portion 30 e thereof and the surface of the bottom end portion 30 c thereof, and penetrates through the outer wall surface 30 n thereof from the grinding surface 30 a of the outer periphery projecting portion 30 d thereof; that is, the groove 30 g extends in a spiral shape from the outer periphery of the upper end face 30 f to the outer wall surface 30 n.
  • the abrasive such as cleaning water
  • the polishing operation can be executed without leaving the polished dust and surplus abrasive (such as cleaning water). Therefore, the wear of the grindstone 30 can be reduced and a polishing finish can be improved more.
  • FIGS. 8 (A) and 8 (B) there is shown the grindstone 30 which includes the four grooves 30 g respectively formed in the four portions thereof.
  • the number of grooves, the shape of grooves, and the extension direction of the grooves 30 g depending on their relationship with the rotation direction of the grindstone 30 are not limited to those shown in FIG. 8 (A) and 8 (B) but can be varied, provided that such variations can provide similar operation effects to the above-described operation effects.
  • the inner wall surface 1 b (inside diameter) and outer wall surface 1 c (outer wall) of the center hole 1 a of the ferrite core 1 can be polished simultaneously using the grindstone. Also, since the movement quantity of the pillar-shaped projecting portion by the moving means 12 a is equal to that of the outer periphery projecting portion by the moving means 12 a , there is no possibility that one of the inner wall surface 1 b and the outer wall surface 1 c of the ferrite core 1 can be polished excessively or insufficiently.
  • the polishing quantities of the inner wall surface 1 b and the outer wall surface 1 c of the ferrite core 1 as well as the shapes thereof after polished can be set simultaneously according to the shape and dimensions of the grindstone and the moving amount of the holding position of the grindstone in the polishing operation.
  • FIG. 11 is a table which shows the measured values of the coaxiality deviation of the center hole and outside diameter of seven ferrite core samples of which the center hole and outside diameter were polished simultaneously using a grindstone according to the invention.
  • the minimum value was 0.01 mm
  • the maximum value was 0.03 mm
  • the mean value was 0.019 mm.
  • the coaxiality deviation of the nine samples was 0.05 mm
  • the maximum value was 0.12 mm
  • the mean value was 0.083 mm.
  • the coaxiality deviation of the ferrite core can be improved outstandingly.
  • the invention can enhance the working accuracy of a ferrite core for a deflecting yoke outstandingly and also can polish the two portions of the ferrite core simultaneously to thereby cut the polishing time by half.
  • the center of the hole of the ferrite core can be made coincident with the center of the outer wall of the ferrite core and thus the two portions of the ferrite core can be polished while maintaining the coaxiality deviation thereof at a desired level.
  • the inner wall surface (inside diameter) and outer wall surface (outer wall) of a ferrite core for a deflecting yoke are polished simultaneously using a single grindstone, simply by adjusting the polishing quantity of one of the inner and outer wall surfaces, the inner and outer wall surfaces of the ferrite core can be ground and polished in such a manner that the ferrite core can provide the above-mentioned given finishing dimensions.
  • the bottom wall surface can be polished without unevenness compared with a case where a conventional grindstone is used.
  • polishing operation can be executed by a single electric motor for driving and rotating the grindstone.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Grinding Of Cylindrical And Plane Surfaces (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
US09/945,813 2000-09-05 2001-09-05 Ferrite core for deflecting yoke, surface polishing apparatus and grindstone therefor Abandoned US20020028643A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2000-269075 2000-09-05
JP2000269075A JP2002079443A (ja) 2000-09-05 2000-09-05 偏向ヨーク用フェライトコア及びその表面研磨装置と砥石

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060009134A1 (en) * 2004-07-09 2006-01-12 Tokyo Seimitsu Co., Ltd. Grinding wheel, grinding apparatus and grinding method
CN104227515A (zh) * 2014-09-01 2014-12-24 常熟市研明电子元器件厂 铁氧体磁芯中柱研磨装置

Families Citing this family (4)

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Publication number Priority date Publication date Assignee Title
KR101217693B1 (ko) * 2010-03-25 2013-01-09 (주)크럭스 페라이트 코어 연삭 장치
JP5997424B2 (ja) * 2011-07-22 2016-09-28 住友電気工業株式会社 圧粉磁心の製造方法
CN103273419A (zh) * 2013-06-06 2013-09-04 广元飞达模具制造有限公司 用于精磨偏转磁芯的磨头
CN112388395B (zh) * 2020-10-15 2021-11-26 南京新康达磁业股份有限公司 一种罐型磁芯气隙加工装置及其加工方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060009134A1 (en) * 2004-07-09 2006-01-12 Tokyo Seimitsu Co., Ltd. Grinding wheel, grinding apparatus and grinding method
CN104227515A (zh) * 2014-09-01 2014-12-24 常熟市研明电子元器件厂 铁氧体磁芯中柱研磨装置

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KR20020019400A (ko) 2002-03-12
JP2002079443A (ja) 2002-03-19

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