JP2003311619A - Grinding method and grinding device for magnetic member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding method and a miniaturizable grinding device for a magnetic member effective for separating fine sludge. <P>SOLUTION: The grinding device 10 has a cutting blade 38 having a cutting edge 44 including heat resistant resin 44b and abrasive grains 44a. The magnetic member 54 containing rare earth alloy is cut using the cutting blade 38 while supplying grinding fluid 58 mainly containing water to a grinding part 60. The sludge 90 is magnetically separated from the used grinding fluid 58 by a magnet separator 74 having 0.25 T or more of surface magnetic flux density. When the grinding fluid 58 is supplied to a tank 92 having barrier plates 94, 96, and 98 inside, the sludge 90 contained in the grinding fluid 58 aggregates and precipitates. The grinding fluid 58 used for separating the sludge 90 is circularly used. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic member grinding method and a grinding device, and more particularly to a magnetic member grinding method and a grinding device for purifying and reusing a grinding waste liquid containing sludge generated during grinding, for example.

[0002]

2. Description of the Related Art An example of a technique for purifying a grinding fluid is disclosed in Japanese Unexamined Patent Publication
No. 0-309647. Here, there is a technique in which the grinding fluid mixed with foreign matter is stored in a tank, the grinding fluid is agitated by a nozzle to separate sludge and abrasive grains from the grinding fluid, and the sludge is discharged to the outside of the tank by a magnetic separator. Proposed. Another example of related art is Japanese Patent Laid-Open No. 8-2997.
No. 17 is disclosed. Here, a technique of using a filter medium to purify the grinding fluid is proposed.

[0003]

However, the former related art was unable to sufficiently remove fine sludge. If fine sludge is to be settled and sufficiently removed, a large-capacity tank of about 3000 liters is required for one device, which causes a problem of increasing the size of the device. Also, the sludge generated when grinding a magnetic member, especially a rare earth alloy, is as small as a few μm, but the latter related technology using a filter material causes clogging and removes such fine sludge efficiently. It was difficult to do. Furthermore, when the magnetic member is cut with a grinding blade containing a heat-resistant resin and superabrasive grains by using a grinding liquid which has not sufficiently removed sludge, the wear of the cutting edge is accelerated. Therefore, a main object of the present invention is to provide a grinding method and a grinding device for a magnetic member, which can be miniaturized and is effective for separating fine sludge.

[0004]

In order to achieve the above object, a method of grinding a magnetic member according to a first aspect of the present invention is such that a grinding liquid containing water as a main component is supplied to a grinding portion while a heat-resistant resin is used. The first step of grinding a rare earth alloy using a grinding means having a cutting edge containing superabrasive grains, the second step of magnetically separating sludge from the grinding fluid discharged from the grinding section, and the second step The grinding liquid is introduced into a tank having a barrier plate inside, and the sludge contained in the grinding liquid is magnetically aggregated and precipitated in the tank to separate the grinding liquid from the grinding liquid. It is characterized in that the grinding liquid subjected to the above is supplied to the grinding section and is circulated and used.

The method for grinding a magnetic member according to claim 2 is
In the method for grinding a magnetic member according to claim 1, in the second step, the sludge is separated by using a magnetic separation means having a surface magnetic flux density of 0.25 T or more.

A grinding device for a magnetic member according to a third aspect is
While supplying a grinding liquid containing water as a main component to the grinding section, a grinding processing means for grinding a rare earth alloy using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains, and discharged from the grinding section. Magnetic separation means for separating the sludge from the grinding fluid, a tank disposed downstream of the magnetic separation means and supplied with the grinding fluid, in which the magnetically agglomerated sludge settles, a barrier plate provided in the tank, And a circulation means for supplying the grinding liquid, which has been subjected to the sludge separation treatment, to the grinding portion for cyclical use.

A grinding device for a magnetic member according to a fourth aspect is
The magnetic member grinding apparatus according to claim 3 is characterized in that the surface magnetic flux density of the magnetic separation means is 0.25 T or more.

According to a fifth aspect of the present invention, in a rare earth magnet, a rare earth alloy is produced by using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains while supplying a grinding liquid containing water as a main component to a grinding portion. The first step of grinding, the second step of magnetically separating the sludge from the grinding fluid discharged from the grinding section, and the grinding fluid after the second step are caused to flow into a tank having a barrier plate inside, A magnetic member for supplying the grinding liquid, which has been subjected to the sludge separation treatment, to the grinding unit and circulating the sludge contained in the grinding liquid, magnetically coagulating and precipitating the sludge to separate it from the grinding liquid. It is obtained by using the above grinding method.

A method of grinding a magnetic member according to a sixth aspect is
A first step of grinding an Nd-Fe-B-based rare earth alloy using a grinding means having a cutting edge containing a heat resistant resin and superabrasives while supplying a grinding liquid containing water as a main component to a grinding part;
The second step of magnetically separating the sludge from the grinding fluid discharged from the grinding section, and the grinding fluid that has passed through the second step are allowed to flow into a tank having a barrier plate inside and included in the tank. A third step of magnetically agglomerating and precipitating the sludge to be separated from the grinding fluid,
It is characterized in that the grinding fluid, which has been subjected to the sludge separation treatment, is supplied to the grinding section and is circulated for use.

A method for grinding a magnetic member according to a seventh aspect is
While supplying a grinding liquid containing water as a main component to the grinding portion, a rare earth alloy having a hard main phase and a strong grain boundary phase is prepared by using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains. A first step of grinding, a second step of magnetically separating the sludge from the grinding fluid discharged from the grinding section, and a second
The third step of injecting the grinding fluid that has undergone the steps into a tank having a barrier plate therein, and magnetically aggregating and precipitating sludge contained in the grinding fluid in the tank to separate the sludge from the grinding fluid is provided. It is characterized in that the grinding liquid which has been subjected to the separation treatment of (1) is supplied to the grinding unit and is circulated.

In the method for grinding a magnetic member according to the first aspect of the present invention, since the sludge can be magnetically separated from the used grinding liquid by a magnetic separation means such as a magnet separator, it is necessary to use a large tank unlike the conventional case. Instead, the device can be miniaturized.

When the grinding fluid is magnetically separated, the sludge which is not separated from the grinding fluid is also magnetized. Therefore, by supplying the grinding liquid to the tank in which the barrier plate is provided, the magnetized sludge contained in the grinding liquid can be aggregated and quickly settled in the tank. At this time, even fine sludge, which is hard to settle, is aggregated and settled and can be quickly separated from the grinding fluid. Therefore, it is not necessary to use a large tank.

Further, if the main component of the grinding liquid is water, the viscosity is lower than that of oil and the resistance during suction is small, so that the sludge can be sucked with a lower magnetic flux density. Further, the grinding liquid can be effectively used by supplying it to the grinding unit and circulating the grinding liquid after the sludge separation treatment.

When the grinding means has a cutting edge containing a heat-resistant resin and superabrasive grains, if the grinding fluid contains fine sludge, the cutting edge is prone to abnormal wear, but the present invention produces fine sludge from the grinding fluid. Since it can also be separated, it is possible to suppress the occurrence of such harmful effects, which is particularly effective. Furthermore, the present invention is effective in obtaining a rare earth magnet as described in claim 5. The magnetic member grinding apparatus according to claim 3,
The same applies to the method of grinding a magnetic member according to claims 6 and 7.

It is considered that the rare earth alloy is easily oxidized, and when it becomes sludge, it is more likely to be oxidized and the nonmagnetic portion is increased, so that it is difficult to be influenced by the magnetic force. Therefore, the sludge containing the rare earth alloy is hard to be magnetically attracted. However, claim 2
In the method for grinding a magnetic member described in (1), the surface magnetic flux density is 0.
By using a magnetic separation means of 25T or more,
The sludge separation capacity is increased, and as a result, wear of the grinding means can be reduced. The same applies to the magnetic member grinding apparatus according to claim 4.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, a grinding apparatus 10 for a magnetic member according to an embodiment of the present invention includes a grinding processing unit 12 and a grinding processing unit 1 for grinding a magnetic member 54 (described later).
2 includes a purifying unit 14 that separates sludge 90 (both described later) from the used grinding liquid 58 and purifies the grinding liquid 58, and a circulation unit 16 that supplies the purified grinding liquid 58 to the grinding processing unit 12 again. .

The grinding processing unit 12 includes a base 18, and a discharge port 20 for discharging the grinding liquid 58 is provided on the base 18.
And a pan 22 having a top opening is arranged. Bread 22
In order to prevent the grinding fluid 58 from splashing to the outside, the plate 24
Is erected. An overhang type X-feed type cutting machine 25 which is a so-called cantilever type is provided on the pan 22. The cutting machine 25 includes a column 26 arranged on the pan 22. A supporting portion (not shown) is provided on one side surface of the column 26, and the rotating shaft 28 is rotatably supported by the supporting portion.

A cutting blade block 30 is attached to the rotary shaft 28, one end of the rotary shaft 28 is supported by a support arm 32, and a pulley 34 is attached to the other end of the rotary shaft 28. A belt 36 is attached to the pulley 34, and the rotating shaft 28 and the cutting blade block 30 are rotated in the direction of arrow A, for example, by rotating the belt 36 by a rotating shaft motor (not shown).

Referring to FIG. 2A, the cutting blade block 3
0 includes a plurality of cutting blades 38, and an annular spacer 40 is interposed between the cutting blades 38. The cutting blade 38 includes a hollow disk-shaped base plate 42, and a cutting edge 44 is attached to the outer peripheral edge of the base plate 42.

As the base plate 42, for example, cemented carbide such as tungsten carbide or high speed steel is used.
Further, as the base plate 42, as shown in JP-A-8-109431 and JP-A-8-109432, a diamond sintered body obtained by sintering diamond or cBN (cubic boron nitride) or the like and a cemented carbide. Alloy base plates can also be used.

Further, as shown in FIG. 2B, the cutting edge 44
Is formed by mixing abrasive grains 44a and heat resistant resin 44b. That is, the abrasive grains 44a are attached to the base plate 42 by the heat resistant resin 44b.

As the abrasive grains 44a, for example, superabrasive grains are used. As the superabrasive grains, natural or synthetic industrial diamond powder, cBN powder, a mixture of natural or synthetic industrial diamond powder-cBN powder, or the like is used. The grain size of the abrasive grains 44a is set to about 160 μm to 250 μm. As the heat resistant resin 44b, a thermosetting resin such as a phenol resin or a polyimide resin is used. Further, the heat resistant resin 44b may contain a metal powder of about several microns.

Returning to FIG. 1, two rails 46 are laid on the pan 22, and an X slider 48 is slidably mounted on the rail 46. A chuck table 50 is mounted on the X slider 48, and a sticking plate 52 is mounted on the chuck table 50. The magnetic member 54 is fixed to the sticking plate 52 by an adhesive during grinding. As the magnetic member 54, for example, a rare earth alloy magnet member for a voice coil motor (VCM) is used. Such a rare earth alloy magnet member has a very high grinding resistance because it contains a hard main phase and a grain boundary phase with strong tenacity. When such a material is ground with a cutting edge composed of a resin and abrasive grains, abrasion of the cutting edge becomes a particular problem.

The voice coil motor referred to here is used for a disk drive as shown in FIG. 9 of US Pat. No. 5,448,437, for example. In FIG. 9, reference numeral 37 is attached to the voice coil motor. When the rare earth alloy magnet member is cut by the cutting blade 38 and then surface-treated, a rare earth magnet is obtained. Such rare earth magnets are described, for example, in US Pat. No. 5,448,437.
No. 3, 4, 5, 6 in FIGS. A method for producing an Nd-Fe-B rare earth magnet is described in U.S. Pat. Nos. 4,770,723 and 4,79.
No. 2,368. Rare earth magnets are RT
R is a rare earth element containing (M) -B magnet, R is Y, T
Is Fe or Fe and Co, M is an additive, and B is boron.

Then, move the X slider 48 in the direction of arrow B (X
The magnetic member 54 can be cut to a predetermined size by sliding the magnetic member 54 in the axial direction) and moving the magnetic member 54 relative to the cutting blade block 30 rotating in the direction of arrow A at a constant speed. Sludge 9 is produced by cutting the magnetic member 54.
0 occurs. At the time of cutting the magnetic member 54, as shown in FIG. 3, the grinding liquid 58 is supplied to the grinding unit 60 from the grinding liquid discharging device 56 arranged near the cutting blade 38.

The grinding liquid 58 used has water as a main component.
For example, if oil is high in viscosity, it becomes difficult for the sludge 90 to move in the grinding liquid 58, but if water is low in viscosity, the sludge 90 can easily move. Therefore, if the main component of the grinding fluid 58 is water, the sludge 90 can be sucked with a lower magnetic flux density.

The grinding fluid discharge device 56 includes a grinding fluid supply passage 62.
The grinding liquid 58 is supplied from the grinding liquid supply passage 62 to the holding part 64. Grinding fluid 5
8 is a discharge port 66 formed at the tip of the retaining portion 64.
It is discharged to the grinding section 60 at a pressure of αPa to 10αPa (α = 9.80665 × 10 ⁴ ). The discharge port 66 is
The angle can be adjusted according to the size of the cutting blade 38.

Returning to FIG. 1, the grinding liquid 58 used in the grinding processing unit 12 is supplied from the discharge port 20 of the pan 22 to the storage tank 70 of the purification unit 14 through the grinding liquid discharge passage 68.
Sludge 90 contained in the grinding fluid 58 is stored in the storage tank 70.
A barrier member 72 is provided to accelerate the precipitation of the magnetic field, and a magnet separator 74 is disposed near the barrier member 72. The magnet separator 74 includes a magnet roll 76 and a magnet roll 7 that attract the sludge 90.
6 and a squeeze roll 78 for separating the grinding fluid 58 from the sludge 90. The barrier member 72 is formed so as to warp upward so that the grinding fluid 58 can easily contact the magnet roll 76.

As shown in FIG. 4A, the magnet roll 76 includes a hollow cylindrical body 80, and a cylindrical body 82 having a main shaft 81 penetrating therethrough is arranged in the cylindrical body 80. On the outer peripheral surface of the cylindrical body 82, for example, four magnets 84 are arranged at substantially equal intervals in the axial direction and the circumferential direction, for a total of 16 magnets 84. As shown in FIG. 4B, two types of magnets, each magnetized in the thickness direction, are used as the magnet 84. The magnets 84 adjacent to each other in the circumferential direction are arranged so that the different poles correspond to each other, and the magnets 84 adjacent to each other in the axial direction are also arranged to correspond to the different poles. The magnet 84 is composed of, for example, a neodymium magnet as shown in U.S. Pat. No. 4,770,723. Sludge 90 is magnet 8
4 and is attracted to the surface of the cylindrical body 80.

If the surface magnetic flux density of the outer peripheral surface of the cylindrical body 80 is 0.25 T (tesla) or more, even sludge containing a rare earth alloy that is difficult to be attracted by the magnet 84 is easily separated from the grinding fluid 58. The magnet roll 76 is rotated, for example, in the direction of arrow C (see FIG. 5) by a motor (not shown). The surface magnetic flux density of the cylindrical body 80 is measured by, for example, using a Gauss meter and a probe (both manufactured by Bell Co., Ltd., a distributor: Toyo Tsusho Co., Ltd.) by bringing the probe into contact with the object to be measured.

Referring to FIGS. 1 and 5, sludge 90
The grinding fluid 58 containing the is supplied to the magnet separator 74 so as to overflow from the upper end of the barrier member 72. The sludge 90 is adsorbed by the magnet roll 76, and then the grinding fluid 58 on the magnet roll 76 is removed by the squeeze roll 78. Further, the scraper 90 abutted on the outer surface of the magnet roll 76 scrapes off the sludge 90 adsorbed by the magnet roll 76 and discharges it to the sludge receiver 88. In this way, the magnet separator 74 magnetically separates the sludge 90 from the used grinding fluid 58. The magnet separator 74 is particularly effective for separating fine sludge.

Grinding liquid 5 which has passed through the magnet roll 76
8 is a tank 92 (barrier plate 9) that is arranged on the downstream side of the magnet separator 74 and the storage tank 70 via an outlet (not shown) provided below the magnet roll 76.
It flows into the tank 92 divided by 4 on the right side). Since the sludge 90 of the rare earth alloy has a coercive force as a magnet even though it is small, the sludge 90 not adsorbed by the magnet roll 76 is also magnetized by the magnet roll 76. Settles quickly. Furthermore, in the tank 92,
Barrier plates 94, 96 for preventing movement of the sludge 90
And 98 are arranged, and the lengthening of the flow path promotes the precipitation of the sludge 90. At this time, the grinding liquid 58
Flows along the path indicated by arrow D. Therefore, in the process of passing through the tank 92, the sludge 90 is
2 is precipitated, and the separation of the sludge 90 and the grinding fluid 58 is further promoted. Further, even fine sludge agglomerates and precipitates and can be quickly separated from the grinding fluid 58. As a result, a large tank is not required to separate the sludge 90 from the grinding liquid 58, and the device can be downsized.

The grinding liquid 58 in the tank 92, which has been purified by the separation process of the sludge 90 in this way, is pumped up by the pump 100 constituting the circulation unit 16 and discharged through the grinding liquid supply passage 62. It is supplied to the device 56 and is recycled.

The operation of the grinding device 10 will be briefly described. First, while supplying the grinding liquid 58 to the grinding unit 60 in the grinding processing unit 12, the magnetic member 5 is cut by the cutting blade 38.
After the 4 is cut, the grinding fluid 58 containing the sludge 90 flows into the storage tank 70 through the grinding fluid discharge path 68. The grinding fluid 58 is supplied to the surface of the magnet separator 74 and sludge 90 is applied to the surface of the magnet separator 74.
Foreign matter such as is adsorbed. The grinding fluid 58 that has passed through the magnet separator 74 is flown into the tank 92. Foreign matter such as sludge 90 remaining in the grinding fluid 58 is precipitated in the tank 92. Only the supernatant liquid thus obtained in the tank 92 is pumped up by the pump 100 and recirculated.
It should be noted that foreign matter such as sludge 90 settled in the tank 92 is scraped off at an appropriate time by any means.

By cutting the magnetic member 54 by circulating the grinding fluid 58 from which the sludge 90 has been removed, the life of the cutting edge 44 can be extended.

Here, an experimental example of the grinding apparatus 10 will be described. The experimental conditions are shown in Table 1.

[0037]

[Table 1]

As shown in Table 1, in this experimental example, the cutting edge 4
4 is phenol resin and diamond abrasive grains (volume ratio 20
%) And. The outer diameter of the cutting blade 38 is 125 mm, and the cutting edge 4
4 has a thickness of 1.0 mm, the base plate 42 has a thickness of 0.9 mm,
The inside diameter of the base plate 42 is 40 mm, the amount of cutting edge (the height of the cutting edge 44)
Is 3 mm to 4 mm.

The rotational speed (peripheral speed) of the cutting blade 38 is 2
The cutting speed is 070 m / min and the cutting speed is 10 mm / min. The grinding fluid 58 includes, for example, JP manufactured by Castrol Co., Ltd.
A solution of -0497N diluted with water by 2% (% by weight) is used. The cutting member is a rare earth alloy magnet member, and Neomax 44H manufactured by Sumitomo Special Metals Co., Ltd. is used.

The experiment yielded the results shown in FIGS. Here, the “surface magnetic flux density” means the magnetic flux density on the outer surface of the cylindrical body 80 of the magnet separator 74.
The “sludge removal rate” is a value indicating how much sludge 90 contained in the grinding fluid 58 can be removed by passing the used grinding fluid 58 immediately after the grinding process through the magnet separator 74. The “working removal amount” specifically refers to the volume (per cutting blade 38) of the portion of the magnetic member 54 cut into sludge 90 per 300 passes of cutting. The "cutting blade wear amount" is specifically the cutting edge 44 of the cutting blade 38 per 300 passes of cutting.
Refers to the volume of the part worn out (per cutting blade 38). The “precipitation amount” refers to the amount of sludge 90 contained in the grinding liquid 58 per measured amount (500 cc of the grinding liquid 58 in this case). The “sludge content” means the weight ratio of the sludge 90 contained in the grinding fluid 58 per 500 cc.

The following experiments were conducted under the conditions shown in Table 1. First, in Experiment 1, the machining removal amount and the cutting blade wear amount in each of the following cases were compared (FIGS. 6A and 6B). One magnet separator (surface magnetic flux density 0.3
T) + tank, 1 magnet separator (surface magnetic flux density 0.25
T) + tank, one magnet separator (surface magnetic flux density 0.2
T) + tank, without magnetic separator + tank

As shown in FIGS. 6A and 6B, as the surface magnetic flux density of the magnet separator 74 increases, the cutting blade wear amount tends to decrease. Further, as the amount of processing removal increases, that is, the number of times of cutting increases,
The difference in the amount of wear of the cutting blade in each case becomes large.

Even when the magnet separator 74 is used, especially when the magnetic flux density is 0.25 T or more, the sludge 90 is efficiently removed, and the life of the cutting blade 38 can be extended.

Next, in Experiment 2, changes in the effects due to the number of installed magnetic separators 74 were compared in the following cases (FIGS. 7A and 7B). In this experiment, the surface magnetic flux density of the magnet separator 74 was set to 0.3T. 1 magnet separator + tank, 2 magnet separators + tank

As shown in FIGS. 7A and 7B, it can be seen that the sludge 90 can be removed by increasing the number of the magnetic separators 74.

Further, in Experiment 3, the separation effect of the sludge 90 due to the difference in the surface magnetic flux density of the magnet separator 74 was compared in the following cases (FIG. 8).
(A) and (b)). The sludge removal rate in the grinding fluid discharge device 56 was measured with one magnet separator and no tank, and with one magnet separator + tank.

As shown in FIGS. 8 (a) and 8 (b), it can be seen that the removal rate of the sludge 90 dramatically increases when the magnetic flux density becomes 0.25 T or more.

Further, it can be seen that the sludge removal rate is higher in the above case. From this, it can be understood that the sludge 90 can be further separated by removing the sludge 90 with the magnet separator 74 and then allowing the sludge 90 to settle in the tank 92. As can be seen from the above experimental example, according to the grinding device 10, a large amount of sludge 90 in the grinding liquid 58 can be removed, so that the grinding liquid 58 can be circulated and used.

That is, in general, in a grinding machine using a cutting blade whose cutting edge is composed of a thermosetting resin and superabrasive grains (diamond-based abrasive grains), when a grinding liquid containing sludge is supplied to the grinding portion, The accumulation of sludge in the grinding portion or between the cutting edge and the magnetic member to be cut causes the surface of the cutting blade to be clogged and the sludge discharging property during grinding to deteriorate. In addition, at that time, the cutting resistance also increases, the resin portion of the cutting blade causes abnormal wear, and the superabrasive grains are shed, so that the cutting efficiency also deteriorates. In a rare earth alloy magnet member in which the magnetic member to be cut is composed of a hard main phase and a viscous grain boundary phase, the cutting load is particularly large and the cutting efficiency becomes extremely poor. If this situation continues, even in the pump that circulates the grinding fluid, sludge will enter and cause abnormal wear, and the temperature of the grinding fluid will rise.

However, in the grinding device 10, since the sludge 90 can be sufficiently removed from the grinding liquid 58, the above-mentioned harmful effects can be suppressed even if the grinding liquid 58 is circulated, and the life of the cutting blade 38 is reduced. Can be extended. In addition, the amount of sludge 90 mixed in the pump 100 that circulates the grinding fluid 58 is also reduced, so that the pump 100 is not clogged, and as a result, abnormal wear of the homp 100 can be suppressed.

Further, since the grinding liquid 58 can be circulated and used, the grinding liquid 58 can be effectively used. Further, the grinding device 10
According to this, since the sludge 90 can be removed by the magnet separator 74 and further aggregated for easy precipitation, unlike the conventional case, a large tank is not required and the apparatus can be downsized. For example, traditionally,
Although a large-capacity tank of about 3000 liters was required, the tank 92 used in the grinding device 10 may have a capacity of about 600 liters.

Further, if the surface magnetic flux density of the magnet separator 74 is set to 0.25 T or more, the separation ability of the sludge 90 is enhanced, so that the abrasion of the heat resistant resin 44b by the sludge 90 is reduced during grinding. In particular, the effect is enhanced when the cutting edge 44 of the cutting blade 38 is made of a heat-curable resin and diamond-based abrasive grains.

Since sludge containing a rare earth alloy easily aggregates, it easily clogs and easily rusts. Therefore,
The filter-type purifying device was inefficient because the filter had to be replaced frequently. In that respect, grinding machine 1
In 0, since the filter is not used, replacement of the filter is unnecessary, and the operating cost can be greatly reduced.

In the above embodiment, the case where the permanent magnet is used as the magnet separator 74 as the magnetic separating means has been described, but the present invention is not limited to this, and an electromagnet or the like may be used. Further, as the grinding means, not only the cutting blade 38 but any grinding means can be used. As other grinding means, 0.1 mm to 0.3 mm
Hard steel wire (piano wire) with a particle size of 30 μm to 60 μm
An example of the wire is a superabrasive grain having a thickness of 30 μm to 60 μm fixed with a phenol resin or the like. The present invention can be applied to a case where a wire saw is performed using this wire. Further, the present invention can be applied not only when separating the sludge 90 from the grinding liquid 58, but also when separating the sludge containing the rare earth alloy from any waste liquid.

[0055]

According to the present invention, since sludge can be magnetically separated from the grinding liquid, it is not necessary to use a large tank unlike the prior art, and the apparatus can be downsized. Further, when the grinding means has a cutting edge containing a heat-resistant resin and superabrasive grains, if the grinding fluid contains fine sludge, the cutting edge is prone to abnormal wear, but the present invention also produces fine sludge from the grinding fluid. Since they can be separated, the occurrence of such adverse effects can be suppressed, which is particularly effective. Furthermore, the present invention is effective in obtaining a rare earth magnet.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

2A is a sectional view schematically showing a cutting blade block, and FIG. 2B is a partial sectional view schematically showing a cutting edge.

FIG. 3 is an illustrative view showing a grinding fluid discharge device arranged in the vicinity of a cutting blade.

FIG. 4A is a perspective view showing a magnet roll, and FIG. 4B is a perspective view showing a magnet.

FIG. 5 is an illustrative view for explaining the function of the scraper.

FIG. 6A is a table showing the results of Experiment 1.
(B) is the graph.

FIG. 7 (a) is a table showing the results of Experiment 2.
(B) is the graph.

FIG. 8 (a) is a table showing the results of Experiment 3.
(B) is the graph.

[Explanation of symbols] 10 Grinding equipment 12 Grinding processing section 14 Purification Department 16 Circulation Department 30 cutting blade block 38 cutting blade 44 cutting edge 44a abrasive grain 44b Heat resistant resin 54 Magnetic member 56 Grinding liquid discharge device 58 grinding fluid 60 grinding section 62 Grinding liquid supply path 68 Grinding liquid discharge passage 70 Storage tank 74 Magnet Separator 90 sludge 92 tanks 100 pumps

Claims (7)

[Claims] 1. A first step of grinding a rare earth alloy by using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains while supplying a grinding liquid containing water as a main component to a grinding section, Second step of magnetically separating the sludge from the grinding fluid discharged from the section, and the grinding fluid that has been subjected to the second step is flown into a tank having a barrier plate inside, and the grinding is performed in the tank. The method further comprises a third step of magnetically aggregating and precipitating sludge contained in the liquid to separate it from the grinding liquid, and supplies the grinding liquid, which has been subjected to the sludge separation treatment, to the grinding unit for cyclic use. Method of grinding members. 2. The method of grinding a magnetic member according to claim 1, wherein in the second step, the sludge is separated by using a magnetic separation unit having a surface magnetic flux density of 0.25 T or more. 3. A grinding treatment means for grinding a rare earth alloy using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains while supplying a grinding liquid containing water as a main component to a grinding part. A magnetic separation means for separating sludge from the grinding fluid discharged from the grinding section, a tank arranged downstream of the magnetic separation means and supplied with the grinding fluid, in which magnetically agglomerated sludge precipitates A grinding device for a magnetic member, comprising: a barrier plate provided in the tank; and a circulation means for supplying the grinding fluid, which has been subjected to the sludge separation treatment, to the grinding section for cyclic use. 4. The surface magnetic flux density of the magnetic separation means is 0.
The magnetic member grinding apparatus according to claim 3, which has a length of 25 T or more. 5. A first step of grinding a rare earth alloy by using a grinding means having a cutting edge containing a heat-resistant resin and superabrasive grains while supplying a grinding liquid containing water as a main component to a grinding section, the grinding. Second step of magnetically separating the sludge from the grinding fluid discharged from the section, and the grinding fluid that has been subjected to the second step is flown into a tank having a barrier plate inside, and the grinding is performed in the tank. A magnetic member that includes a third step of magnetically aggregating and precipitating sludge contained in the liquid to separate it from the grinding liquid, and supplies the grinding liquid that has been subjected to the sludge separation treatment to the grinding unit for circulation. A rare earth magnet obtained by using the above grinding method. 6. A Nd-Fe-B rare earth alloy is ground using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains while supplying a grinding liquid containing water as a main component to a grinding section. A first step, a second step of magnetically separating sludge from the grinding fluid discharged from the grinding section, and the grinding fluid after the second step are flowed into a tank having a barrier plate provided therein, A third step of magnetically aggregating and precipitating sludge contained in the grinding fluid in the tank to separate the sludge from the grinding fluid is provided, and the grinding fluid subjected to the sludge separation treatment is supplied to the grinding unit. A method of grinding magnetic members that is used in a circulating manner. 7. A hard main phase and a highly viscous grain boundary phase are obtained by using a grinding means having a cutting edge containing a heat resistant resin and superabrasive grains while supplying a grinding liquid containing water as a main component to a grinding part. A step of grinding a rare earth alloy having: a second step of magnetically separating sludge from a grinding fluid discharged from the grinding section; and the grinding fluid after the second step provided inside a barrier plate. And a sludge contained in the grinding fluid is magnetically aggregated and precipitated in the tank to separate the sludge from the grinding fluid, and the sludge is separated from the grinding fluid. Is a method for grinding a magnetic member, wherein the magnetic material is supplied to the grinding unit and circulated for use.