WO1998018597A1 - A method and device for magneto-abrasive machining - Google Patents
A method and device for magneto-abrasive machining Download PDFInfo
- Publication number
- WO1998018597A1 WO1998018597A1 PCT/US1996/018180 US9618180W WO9818597A1 WO 1998018597 A1 WO1998018597 A1 WO 1998018597A1 US 9618180 W US9618180 W US 9618180W WO 9818597 A1 WO9818597 A1 WO 9818597A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- magnetic
- supplying
- fluid jet
- abrasive powder
- longitudinal axis
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
- B24C5/00—Devices or accessories for generating abrasive blasts
- B24C5/08—Devices for generating abrasive blasts non-mechanically, e.g. of metallic abrasives by means of a magnetic field or by detonating cords
Definitions
- the present invention relates to a method of and a device for magnetic-abrasive machining of parts.
- Magnetic-abrasive machining of parts is generally known in the art. It is usually that cylindrical parts are machined in the following way. A magnetic field is generated, a part is placed in the magnetic field and rotated about its axis and simultaneously oscillated along its axis, and a magnetic-abrasive powder is introduced into the area of machining simultaneously with cooling liquid which is poured into the area.
- electromagnetic inductors are used, in which the magnetic flux is closed through a metal magnetic conductor and pole shoes as well as working gaps and the part to be machined. The external magnetic flux passes through the magnetic- abrasive powder and the metal part, magnetizes them, and therefore the part magnetically attracts the magnetic-abrasive powder.
- a gradient of the magnetic field is produced which retains the magnetic-abrasive powder in the working gaps when the part is rotated and not rotated.
- the gaps are limited by the surface of the pole shoes .
- Accuracy of cylindrical parts is characterized by out-of-roundness and deviation of shape of a longitudinal cross-section. With the existing methods of the magnetic-abrasive machining the required out-of roundness is provided, as disclosed for example in "Machining Time Estimation for Magnetic Abrasive Processes," G.Z. Kremen, et al., Int. G.
- Another disadvantage is a relatively low material removal rate which is lower than the material removal rate during conventional grinding
- the reason for this disadvantage is that the conventional devices cannot generate a value of the magnetic induction more than 1 6 T
- This disadvantage is even more substantial when a non-magnetic part composed for example of ceramis, glass .non-ferrous metals, etc is machined, since the part does not form its own magnetic field and the magnetic-abrasive powder is not pressed against the part
- a method of magnetic-abrasive machining of an article having a longitudinal axis, comprising the steps of generating an external field providing a magnetic flux, placing a part in the magnetic field, so that the magnetic flux extends perpendicular to the longitudinal axis of the part, supplying a magnetic-abrasive powder to the part in the magnetic field, rotating the part about the longitudinal axis and oscillating the part along the longitudinal axis, so that the magnetic-abrasive powder is dispaced by the rotating part in a circumferential d ⁇ ection, wherein the generating of the external magnetic field to provide a magnetic flux includes forming the external magnetic field by a coil which has two substantially coaxial coil portions which are connected with one another and arranged
- It is also an object of the present invention to provide a device for magnetic-abrasive machining of parts which has means for generating an external magnetic field providing a magnetic flux, means for rotating a part in the magnetic field, so that magnetic flux extends perpendicular to a longitudinal axis of the part and at the same time oscillating the part along its longitudinal axis, means for supplying a magnetic-abrasive powder to the part in the magnetic field which magnetic-abrasive powder is displaced by the rotating part, and wherein the means for forming the external magnetic field for providing a magnetic flux includes a coil with two coil portions connected with one antoher and arranged so that the part is located axially between the coil portions, and a fluid jet is supplied under pressure toward the magnetic-abrasive powder to press it to the part
- FIG 1 is a view schematically showing a device for a magnetic- abrasive machining of a part in accordance with the present invention
- FIG 2 is a view schematically showing movements of a magnetic- abrasive powder in the inventive method of machining
- a device for magnetic-abrasive machining in accordance with the present invention as shown in FIG 1 includes means for generating a magnetic field formed as a electromagnetic co ⁇ j.1 r wb. ⁇ ch is composed of two electromagnetic coil sections 2 and 3 connected with one another by connecting elements
- the electromagnetic coil 1 generates a magnetic flux which is identified with reference numeral 4
- the part to be machined is located in a gap between the coil sections 2 and 3
- the part 5 is rotated about its longitudinal axis and oscillated in a direction of its longitudinal axis by well-known means
- the part 5 can be held in holders which are rotated by a drive and displaced in the longitudinal direction
- a magnetic-abrasive powder 6 is introduced into the machining zone and retained by a magnetic gradient which will be explained in detail later on During the rotation of the part 5 the magnetic-abrasive powder 6 is somewhat displaced in the circumferential direction by the part from the zones of the magnetic flux as shown in FIG 1
- the magnetic gradient of the magnetic field retains the magnetic
- a fluid jet (a gas jet or a liquid jet) is supplied under pressure so as to be directed toward the magnetic-abrasive powder and to press the magnetic-abrasive powder against the part
- the jet can be produced for example by nozzles 7 It is preferably directed radially towards the center of the part
- the jet is directed toward the areas, to where the magnetic-abrasive powder is displaced by the rotating part from the zone of the magnetic flux as shown in FIG 1
- a maximum value of the pressure of the fluid jet is selected so as to maintain the effect which is characteristic only for the magnetic-abrasive machining
- the grains of the magnetic abrasive powder must be retained from falling out from the machining zone by a magnetic gradient They must be pressed against the part by the fluid jet directed to the center of the part and perform the movements which are similar to the reciprocal movements shown in FIG 2 by the arrows
- the pressure of the fluid jet must be uniform along the whole area of the displaced magnetic-abrasive powder This
- the method and device in accordance with the present invention can also be utilized when a part to be machined is ferromagnetic In this case the force of pressing the magnetic abrasive powder against the part caused by magnetic attraction of the ferromagnetic part is further increased by the pressure applied by the fluid jet against the magnetic abrasive powder It will be understood that each of the elements described above, or two ro more together, may also find a useful application in otehr types of constructions differing from the types described above
Abstract
A magnetic-abrasive machining the part (5) to be machined is located axially between two substantially coaxial coil sections (2, 3) on electromagnetic coil (1) forming a magnetic flux (4), and a magnetic-abrasive powder (6) is supplied toward the part in a machining area axially between the coil sections (2, 3). A magnetic field gradient is formed in the magnetic field so as to retain the magnetic-abrasive powder (6) on the part (5). A fluid jet is supplied under pressure toward the magnetic-abrasive powder (6) so as to press the magnetic-abrasive powder (6) against the surface of the part (5).
Description
Description
A METHOD AND DEVICE FOR MAGNETO-ABRASIVE MACHINING
Background of the Invention
The present invention relates to a method of and a device for magnetic-abrasive machining of parts.
Magnetic-abrasive machining of parts is generally known in the art. It is usually that cylindrical parts are machined in the following way. A magnetic field is generated, a part is placed in the magnetic field and rotated about its axis and simultaneously oscillated along its axis, and a magnetic-abrasive powder is introduced into the area of machining simultaneously with cooling liquid which is poured into the area. In the device for the magnetic-abrasive machining, electromagnetic inductors are used, in which the magnetic flux is closed through a metal magnetic conductor and pole shoes as well as working gaps and the part to be machined. The external magnetic flux passes through the magnetic- abrasive powder and the metal part, magnetizes them, and therefore the part magnetically attracts the magnetic-abrasive powder. Simultaneously, a gradient of the magnetic field is produced which retains the magnetic-abrasive powder in the working gaps when the part is rotated and not rotated. The gaps are limited by the surface of the pole shoes . It is advisable to further improve the existing magnetic- abrasive machining methods and devices which provide accuracy of machining of the parts and at the same time to increase the material removal rate of machining. Accuracy of cylindrical parts is characterized by out-of-roundness and deviation of shape of a longitudinal cross-section. With the existing methods of the magnetic-abrasive machining the required out-of roundness is provided, as disclosed for example in "Machining Time Estimation for Magnetic Abrasive Processes," G.Z. Kremen, et al., Int. G. Trod. Res., 1994, volume 32, number 12, pages 2817-2825. As for the shape of the longitudinal cross-section of a part, it does not correspond to the requirements since the part obtains a barrel-like shape as a result
of the machining The formation of the barrel-like shape is caused by a non-unifrmity of the magnetic field both at the pole shoes and in the longitudinal cross section of the cylindrical part A gradient of magnetic field is formed along the perimeter of the pole shoes and at the ends of the part A different value of the magnetic induction leads to a non- uniform pressing of the magnetic-abrasive powder against the part and correspondingly to a non-uniform material removal at the ends of the part
Another disadvantage is a relatively low material removal rate which is lower than the material removal rate during conventional grinding The reason for this disadvantage is that the conventional devices cannot generate a value of the magnetic induction more than 1 6 T This disadvantage is even more substantial when a non-magnetic part composed for example of ceramis, glass .non-ferrous metals, etc is machined, since the part does not form its own magnetic field and the magnetic-abrasive powder is not pressed against the part
Summary of the invention
Accordingly, it is an object of the present invention to provide a method of and a device for magnetic-abrasive machining of parts, which avoid the disadvantages of the prior art In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a method of magnetic-abrasive machining of an article, having a longitudinal axis, comprising the steps of generating an external field providing a magnetic flux, placing a part in the magnetic field, so that the magnetic flux extends perpendicular to the longitudinal axis of the part, supplying a magnetic-abrasive powder to the part in the magnetic field, rotating the part about the longitudinal axis and oscillating the part along the longitudinal axis, so that the magnetic-abrasive powder is dispaced by the rotating part in a circumferential dπection, wherein the generating of the external magnetic field to provide a magnetic flux includes forming the external magnetic field by a coil which has two substantially coaxial coil portions which are connected with one another and arranged so that the part is located axially between the coil portions, and a fluid jet is
supplied under pressure toward the magnetic-abrasive powder to press it to the part
It is also an object of the present invention to provide a device for magnetic-abrasive machining of parts which has means for generating an external magnetic field providing a magnetic flux, means for rotating a part in the magnetic field, so that magnetic flux extends perpendicular to a longitudinal axis of the part and at the same time oscillating the part along its longitudinal axis, means for supplying a magnetic-abrasive powder to the part in the magnetic field which magnetic-abrasive powder is displaced by the rotating part, and wherein the means for forming the external magnetic field for providing a magnetic flux includes a coil with two coil portions connected with one antoher and arranged so that the part is located axially between the coil portions, and a fluid jet is supplied under pressure toward the magnetic-abrasive powder to press it to the part When the method is performed and the device is designed in accordance with the present invention, it eliminates the disadvantages of the prior art
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings
Brief Description of the Drawings FIG 1 is a view schematically showing a device for a magnetic- abrasive machining of a part in accordance with the present invention, and
FIG 2 is a view schematically showing movements of a magnetic- abrasive powder in the inventive method of machining
Description of the Preferred Embodiments
A device for magnetic-abrasive machining in accordance with the present invention as shown in FIG 1 includes means for generating a magnetic field formed as a electromagnetic coιj.1 rwb.ιch is composed of
two electromagnetic coil sections 2 and 3 connected with one another by connecting elements The electromagnetic coil 1 generates a magnetic flux which is identified with reference numeral 4 The part to be machined is located in a gap between the coil sections 2 and 3 The part 5 is rotated about its longitudinal axis and oscillated in a direction of its longitudinal axis by well-known means For example, the part 5 can be held in holders which are rotated by a drive and displaced in the longitudinal direction A magnetic-abrasive powder 6 is introduced into the machining zone and retained by a magnetic gradient which will be explained in detail later on During the rotation of the part 5 the magnetic-abrasive powder 6 is somewhat displaced in the circumferential direction by the part from the zones of the magnetic flux as shown in FIG 1 When the part is non-ferromagnetic the magnetic gradient of the magnetic field retains the magnetic-abrasive powder on the surface of the part, however, there is no force which can actively press the magnetic abrasive powder against the part
In accordance with the present invention, a fluid jet (a gas jet or a liquid jet) is supplied under pressure so as to be directed toward the magnetic-abrasive powder and to press the magnetic-abrasive powder against the part The jet can be produced for example by nozzles 7 It is preferably directed radially towards the center of the part In accordance with a preferred approach, the jet is directed toward the areas, to where the magnetic-abrasive powder is displaced by the rotating part from the zone of the magnetic flux as shown in FIG 1 A maximum value of the pressure of the fluid jet is selected so as to maintain the effect which is characteristic only for the magnetic-abrasive machining In particular, the grains of the magnetic abrasive powder must be retained from falling out from the machining zone by a magnetic gradient They must be pressed against the part by the fluid jet directed to the center of the part and perform the movements which are similar to the reciprocal movements shown in FIG 2 by the arrows Also, the pressure of the fluid jet must be uniform along the whole area of the displaced magnetic-abrasive powder This requirement is connected to the fact that the jet pressure must replace a magnetic force which presses the magnetic-abrasive powder when a magnetic part is
performed and magnetic attraction force is directed toward the center of the part The uniformity of pressure of the jet is necessary so that the powder is uniformly pressed against the surface to be machined in order to avoid the barrel-like shape
Since the pressing force of the magnetic-abrasive powder against the part is increased, it is possible to increase the rotary speed of the part so as to increase the machining removal rate The interaction of a high non-linear magnetic field gradient and the high uniform presmg force substantially increases the material removal rate
It is to be understood that the method and device in accordance with the present invention can also be utilized when a part to be machined is ferromagnetic In this case the force of pressing the magnetic abrasive powder against the part caused by magnetic attraction of the ferromagnetic part is further increased by the pressure applied by the fluid jet against the magnetic abrasive powder It will be understood that each of the elements described above, or two ro more together, may also find a useful application in otehr types of constructions differing from the types described above
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims
Claims
1 . A method of magnetic-abrasive machining of a part having a longitudinal axis, comprising the steps of generating an external magnetic field providing a magnetic flux by an electromagnetic coil having substantially coaxial coil sections which are axially spaced from one another and connected with one another; placing the article in the magnetic field axially between the coil sections so that the magnetic flux extends perpendicular to the longitudinal axis of the part; rotating the part about the longitudinal axis and oscillating the part along the part about the longitudinal axis and oscillatnig the part along the longitudinal axis; supplying a magnetic-abrasive powder into the machining zone onto the part in an area axially between the coil sections; and supplying a fluid jet under pressure the magnetic-abrasive powder so as to press the magnetic-abrasive powder against a surface of the part.
2. A device for magnetic-abrasive machining of a part having a longitudinal axis, comprising means for generating an external magnetic field providing a magnetic flux and including an electromagnetic coil having two substantially coaxial coil portions which are spaced from one another and spaced from one another; means for placing a part in the magnetic field axially between
3. said coil sections so that the magnetic flux extends perpendicular to the longitudinal axis of the part; means for rotating the part about the longitudinal axis and oscillating the part along the longitudinal axis; means for supplying a magnetic-abrasive powder to the part in the magnetic field in a machining zone axially between said coil sections of said electromagnetic coil; means for supplying a fluid jet toward the magnetic-abrasive powder so as to press the magnetic-abrasive powder against a surface of the part.
4. A method as defined in claim 1 , wherein said supplying includes supplying the fluid jet to an area to which the magnetic-abrasive powder is displaced under the_actipr tefιF. rta ©'i?ι of the part. A method as defined in claim 1 , wherein said supplying the fluid jet includes supplying the fluid jet in a direction toward a center of the part
A devce as defined in claim 2, wherein said means for supplying the fluid jet is arranged so that the fluid jet supplied by said fluid jet supplying means is directed toward a region, to which the magnetic-abrasive powder is displaced under the action of rotation of the part
A device as defined in claim 2, wherein said means for supplying a fluid jet is arranged so that the fluid jet supplied by said fluid jet supplying means is directed toward a center of the part
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/441,721 US5569061A (en) | 1995-04-12 | 1995-04-12 | Method and device for magneto-abrasive machining of parts |
| PCT/US1996/018180 WO1998018597A1 (en) | 1995-04-12 | 1996-10-28 | A method and device for magneto-abrasive machining |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/441,721 US5569061A (en) | 1995-04-12 | 1995-04-12 | Method and device for magneto-abrasive machining of parts |
| PCT/US1996/018180 WO1998018597A1 (en) | 1995-04-12 | 1996-10-28 | A method and device for magneto-abrasive machining |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1998018597A1 true WO1998018597A1 (en) | 1998-05-07 |
Family
ID=26791356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US1996/018180 WO1998018597A1 (en) | 1995-04-12 | 1996-10-28 | A method and device for magneto-abrasive machining |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US5569061A (en) |
| WO (1) | WO1998018597A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5775976A (en) * | 1997-03-27 | 1998-07-07 | Scientific Manufacturing Technologies, Inc. | Method and device for magnetic-abrasive machining of parts |
| US5813901A (en) * | 1997-03-27 | 1998-09-29 | Scientific Manufacturing Technologies Inc | Method and device for magnetic-abrasive machining of parts |
| US5951369A (en) * | 1999-01-06 | 1999-09-14 | Qed Technologies, Inc. | System for magnetorheological finishing of substrates |
| US6561874B1 (en) * | 2000-11-22 | 2003-05-13 | Qed Technologies, Inc | Apparatus and method for abrasive jet finishing of deeply concave surfaces using magnetorheological fluid |
| DE102005010286A1 (en) * | 2005-03-01 | 2006-09-07 | Thiel, Wolfgang, Dr. | Machining apparatus and method for machining surfaces in recesses of workpieces |
| US7899374B2 (en) * | 2007-01-11 | 2011-03-01 | Ricoh Company, Ltd. | Magnetic particle carrying device, and developing unit, process cartridge, and image forming apparatus using the same, and surface treatment method of the same |
| US9579766B2 (en) * | 2012-02-28 | 2017-02-28 | University Of Florida Research Foundation | System and method of magnetic abrasive surface processing |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU73728A1 (en) * | 1948-05-19 | 1948-11-30 | А.Н. Головин | Electromagnet |
| US2929120A (en) * | 1957-12-04 | 1960-03-22 | Gen Motors Corp | Method of definning sand cores |
| SU1541031A1 (en) * | 1988-02-29 | 1990-02-07 | Физико-технический институт АН БССР | Method of magnetic abrasive working |
| US4977707A (en) * | 1987-11-18 | 1990-12-18 | Chachin Viktor N | Device for external magnetic abrasive machining of cylindrical components |
| JPH03184761A (en) * | 1989-12-11 | 1991-08-12 | Isuzu Motors Ltd | Magnetic grinding attachment |
| SU1703413A2 (en) * | 1989-01-04 | 1992-01-07 | Краматорский Научно-Исследовательский И Проектно-Технологический Институт Машиностроения | Method for magnetic abrasive machining of parts |
-
1995
- 1995-04-12 US US08/441,721 patent/US5569061A/en not_active Expired - Fee Related
-
1996
- 1996-10-28 WO PCT/US1996/018180 patent/WO1998018597A1/en active Application Filing
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU73728A1 (en) * | 1948-05-19 | 1948-11-30 | А.Н. Головин | Electromagnet |
| US2929120A (en) * | 1957-12-04 | 1960-03-22 | Gen Motors Corp | Method of definning sand cores |
| US4977707A (en) * | 1987-11-18 | 1990-12-18 | Chachin Viktor N | Device for external magnetic abrasive machining of cylindrical components |
| SU1541031A1 (en) * | 1988-02-29 | 1990-02-07 | Физико-технический институт АН БССР | Method of magnetic abrasive working |
| SU1703413A2 (en) * | 1989-01-04 | 1992-01-07 | Краматорский Научно-Исследовательский И Проектно-Технологический Институт Машиностроения | Method for magnetic abrasive machining of parts |
| JPH03184761A (en) * | 1989-12-11 | 1991-08-12 | Isuzu Motors Ltd | Magnetic grinding attachment |
Also Published As
| Publication number | Publication date |
|---|---|
| US5569061A (en) | 1996-10-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4306386A (en) | Method of finishing ferromagnetic articles by ferromagnetic abrasive powders in magnetic field | |
| CA1317205C (en) | Magnetic treatment of ferromagnetic materials | |
| US4990306A (en) | Method of producing polar anisotropic rare earth magnet | |
| US5569061A (en) | Method and device for magneto-abrasive machining of parts | |
| Jain et al. | Force analysis of magnetic abrasive nano-finishing of magnetic and non-magnetic materials | |
| US6036580A (en) | Method and device for magnetic-abrasive machining of parts | |
| US4603509A (en) | Magnetic attraction system grinding method | |
| EP0027362B1 (en) | Magnetic material treatment method and apparatus | |
| Qian et al. | Precision internal grinding with a metal-bonded diamond grinding wheel | |
| US5813901A (en) | Method and device for magnetic-abrasive machining of parts | |
| JPS6246306B2 (en) | ||
| US10586639B2 (en) | Array of three pole magnets | |
| US5775976A (en) | Method and device for magnetic-abrasive machining of parts | |
| JPH0788758A (en) | Surface pressure uniformizing device for polishing tool | |
| SU1703413A2 (en) | Method for magnetic abrasive machining of parts | |
| SU992173A1 (en) | Method of abrasive magnetic working | |
| RU2068768C1 (en) | Tool for strengthening treatment | |
| JPH0550377A (en) | Magnetogrinding method | |
| JPH04365553A (en) | Head for magnetic polishing and automatic magnetic polishing device employing this head | |
| JP2794862B2 (en) | Magnetic grinding device | |
| JPH03184761A (en) | Magnetic grinding attachment | |
| SU1585124A1 (en) | Method of magnetoabrasive machining | |
| JPH0542476A (en) | Magnetic polishing method | |
| SU859126A1 (en) | Apparatus for magnetic abrasive working | |
| SU1404246A1 (en) | Electric magnetic plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
| DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| 122 | Ep: pct application non-entry in european phase |