APPARATUS FOR MAGNETIZATION

FIELD OF INVENTION

[0001] The present invention relates to an apparatus for magnetization and more particularly to a permanent magnet based magnetization apparatus.

BACKGROUND OF INVENTION

[0002] A conventional method for permanent magnetization is based on excitation of an electromagnet by an external impulse power source. In this method, a high magnitude electric current is passed for a short time through an electromagnet that produces the required magnetic field to saturate an end magnet coupled to it. The end magnet retains a permanent magnetic field when the electromagnet is removed and hence is magnetized. This method has numerous drawbacks such as the requirement for an external impulse power source, high heat generation, high-energy loss and greater cycle time. Further, electromagnet based magnetization method fails in achieving homogeneous magnetization due to variation in current amplitude because of change in resistance of the electromagnet due to temperature rise. Still further, electromagnet based magnetization is hazardous and can potentially cause safety concerns at workplace.

[0003] To overcome this, an alternate method is to use a permanent magnet as a source of magnetic field. This method does not require any external power source and there is practically no energy loss. A device for magnetizing ferrite rubber and plastic magnetic plates using ~ permanent magnets has been disclosed in Chinese Patent No. CN2814632. In US Patent No.US5424703A, an apparatus and process for magnetizing strip and sheet material using a permanent magnet has been described. Further, a permanent magnet based magnetization device, which magnetizes a work piece ring, is presented in US Patent No. 6621396B2.

[0004] The devices disclosed in the above mentioned patent citations and in other applications in the prior art require very less magnetizing force and can be used only for magnetizing magnets having very less thickness. Further, prior art magnetization devices lack in efficient design since there is substantial leakage of magnetic flux emanating from the source permanent magnet and is therefore incapable of generating strong magnetic fields. Hence prior art arrangements using permanent magnet as source cannot be used for permanent magnetization of large magnets such as those used in electric motors and generators.

[0005] Therefore to obviate shortcomings in the prior art, there is requirement for an apparatus for magnetization having an improved structure and design which is capable of permanently magnetizing large magnets such as those used in electric motors and generators and this forms the principal objective of the present invention. It is a further objective of the present invention to provide a magnetizing apparatus having a structural design that prevents deviation of magnetic lines of force from its path to the non-magnetized magnet and is capable of withstanding strong magnetic force. It is yet another objective of the present invention to provide a magnetizing apparatus, which achieves homogeneous magnetization of the end magnet.

SUMMARY OF THE INVENTION

[0006] The invention discloses a method to permanently and homogeneously magnetize a ferromagnetic material by way of placing the ferromagnetic material in contact with two permanent magnets for a pre determined duration. After removing the permanent magnets, the ferromagnetic material retains the magnetic property. This apparatus for magnetizing a ferromagnetic material does not use electricity and the retentivity is higher as compared to the magnetization achieved by the use of temporary magnets using electricity.

BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 Shows a typical apparatus for magnetization of a material.

[0008]Figure 2 Shows the setup for magnetization process.

[0009] Figure 3 Illustrates removal of material after magnetization.

[00010] Figure 4 Illustrates the magnetic flux linkage within the apparatus.

DETAILED DESCRIPTION OF THE INVENTION

[00011] Hereinafter, a preferred embodiment of the present invention is described with reference to the drawings.

[00012] As shown in Fig. 1, the apparatus for magnetization as per the present invention consists of a movable member and a stationary member. The movable member further consists of an upper core 102, a source magnet 100 and a top pole piece 101. The magnetic top pole piece 101 is frustum shaped and is attached to the source magnet 100, which is attached to the magnetic upper core 102, which in turn is attached to a movable rod 106. The movable rod 106 can be moved in the vertical direction by adjusting a nut 109. The stationary member consists of a bottom core 105 and a bottom pole piece 104. The magnetic bottom pole piece 104 is secured to the magnetic bottom core 105, which is secured to a base plate 107. The base plate 107 has two pillars 108 mounted on it. The base plate 107 and the pillars 108 is made of non magnetic material to prevent magnetic flux leakage.

[00013] An end magnet 103, which is the ferromagnetic material to be permanently magnetized, can be attached either to the top pole piece 101 or to the bottom pole piece 104. The end magnet is preferably kept secured to the top pole piece 101 as in this arrangement, the end magnet 103 will hold on to the top pole piece 101 due to the magnetic attraction of the source magnet 100. Multiple source magnets can be used and it can be of any type based on the magnetic field strength required to magnetize the end magnet 103. The source magnet 100 is preferably rectangular and is preferably made of ceramic or any rare earth metal. The bottom pole piece 104 is preferably frustum shaped.

[00014] Fig. 2 and Fig. 3 respectively illustrate the engaged and disengaged configuration of the present invention. Once the movable member is engaged with the stationary member, magnetic lines of force 110 emanating from the source magnet 100, travels through a closed loop consisting the top pole piece 101, the ferromagnetic material 103, the bottom pole piece 104, the bottom core 105, the upper core 102 and the source magnet 100 leading to permanent magnetization of the end magnet 103. The end magnet is removed from the magnetizer once it is saturated.

[00015] Fig. 4 illustrates the closed loop path of the magnetic lines of force 110. The frustum shape of the top pole piece 101 concentrates the magnetic lines of force emanating from the source magnet 100 and ensures that there is no leakage. Thus, the structure of the magnetizer as per the present invention makes it possible to continuously maintain a very strong magnetic field. The upper core and the bottom core is preferably made of mild steel having relative permeability 2000 or of silicon steel having relative permeability in the range 7000-9000.

[00016] The apparatus for magnetization as per the present invention can be used to magnetize magnets of any shape, size and strength. The magnetization is instantaneous. As soon as the magnetic circuit is complete, the magnetization process completes. The device does not use any external power source and has a structural part capable of withstanding high magnetic force developed while magnetizing large magnets. Further, magnetization achieved by the magnetizer as per the present invention is more homogenous when compared to magnetization by electromagnet-based magnetizers. This is because of the frustum shaped design of the top pole piece, which reduces fringing effect.

We claim:

1. An apparatus for magnetization comprising: a movable member further comprising a frustum shaped magnetic top pole piece, atleast one source magnet and a magnetic upper core; a non magnetized end magnet fixed to the top pole piece; and a stationary member further comprising a magnetic bottom pole piece and a magnetic bottom core; wherein on engagement of the movable member with the stationary member, magnetic lines of force emanating from the source magnet, travels through a closed loop consisting the top pole piece, the end magnet, the bottom pole piece, bottom core, the top core and the source magnet thereby permanently magnetizing the said end magnet to saturation.

2. An apparatus for magnetization comprising: a movable member further comprising a frustum shaped magnetic top pole piece, atleast one source magnet and a magnetic upper core; a stationary member further comprising a magnetic bottom pole piece and a magnetic bottom core; and a non magnetized end magnet fixed to the bottom pole piece; wherein on engagement of the movable member with the stationary member, magnetic lines of force emanating from the source magnet, travels through a closed loop consisting the top pole piece, the end magnet, the bottom pole piece, bottom core, the top core and the source magnet thereby permanently magnetizing the said end magnet to saturation.

3. The apparatus for magnetization as claimed in claim 1 and claim 2, wherein the top pole piece is secured to the source magnet, which is secured to the upper core, which in turn is secured to a movable rod.

4. The apparatus for magnetization as claimed in claim 1 and claim 2 wherein the bottom pole piece is secured to the bottom core which in turn is secured to a non magnetic base plate, the said base plate having atleast two non magnetic pillars mounted on it.

5. The apparatus for magnetization as claimed in claim 1 and claim 2 wherein the bottom pole piece is preferably frustum shaped.

6. The apparatus for magnetization as claimed in claim 1 and claim 2 wherein the source magnet is preferably rectangular shaped.

7. The apparatus for magnetization as claimed in claim 1 and claim 2 wherein the upper core and the bottom core is made of mild steel having relative permeability 2000.

8. The apparatus for magnetization as claimed in claim 1 and claim 2 wherein the upper core and the bottom core is made of silicon steel having relative permeability in the range of 7000-9000.

9. The apparatus for magnetization as hereinabove described in the specification and illustrated in the accompanying drawings.