JPH0543904A - Production of permanent magnet green compact - Google Patents

Abstract

PURPOSE:To effectively prevent permanent magnet powder from flying by improving a shielding plate in a method for conveying rubber molds, etc., via a revolving route. CONSTITUTION:A rubber mold 10 packed with permanent magnet powder 5 of high density at the position A is turned to the position B by a carrier 2 and enters under a horizontal shielding plate 43 reaching the position of an in-magnetic field die press device 6 along the carrier 2 to seal its release port. Under these conditions, magnetic field is instantaneously applied to the powder 5 by a pulse magnetic field generator 44. Successively, when the mold 10 reaches the position C with its sealed state kept and is moved to the top surface of a lower punch 1b to be stopped, the powder 5 is given press forming between an upper punch 1a whose undersurface is on standby at the same height as that of the undersurface of the shielding plate 43 and the lower punch 1b. After that is completed, the mold 10 reaches the position D and the compact is taken out by a takeoff device 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for producing a permanent magnet powder compact.

[0002]

2. Description of the Related Art In a method for producing an anisotropic permanent magnet which is magnetically orientated in a magnetic field, a parallel die press method is generally used for forming a flat article which occupies most of magnet products. It is well known that the parallel die press method has a lower Br and (BH) _{max of the} magnet than the vertical die press method.

As a method of obtaining the same magnetic characteristics as in a vertical die press in a flat die parallel die press, a method has been proposed in which a preformed rubber container is placed in a mold, and rare earth cobalt alloy powder is placed in the rubber container and then the parallel die press is performed. (Japanese Patent Publication No. 55-26601).

According to the technique disclosed in Japanese Examined Patent Publication No. 55-26601, the inventors of the present invention have cracked or chipped the powder compact.
It has been found that it can not be applied to actual production as it is because cracks and deformations occur, and it prevents the product defects due to such cracks and has a high efficiency and a high-performance anisotropic permanent magnet. Has been proposed (Japanese Patent Application No. 2-330048, hereinafter referred to as “prior application”).

That is, the present inventors have found that it is effective to fill the rubber mold with the permanent magnet powder at a high density in order to prevent cracking or chipping of the molded body, and for the rare earth magnet, It was proposed in the previous application that the packing density should be 17% or more of the true density, 14% or more of the ferrite magnet, preferably 25% or more of the rare earth magnet, and 20% or more of the ferrite magnet. When the permanent magnet powder is filled in such a high density, a sufficient degree of orientation cannot be obtained in a normal static magnetic field, so after filling the permanent magnet powder in a high density, the rubber mold is capped, and then the magnetic field is momentarily changed. Then, by pressing in a magnetic field or no magnetic field, the anisotropic permanent magnet with a high degree of orientation is cracked or chipped,
It can be manufactured without deformation.

Further, in the prior application, the rubber mold was densely filled with the permanent magnet powder, the magnetic field application die press, and the green compact was taken out from the rubber mold by sequentially repeating the process in which the rubber mold is circulated. It was proposed to improve the sex.

When the pulsed magnetic field is applied to the permanent magnet powder, it is necessary to seal the permanent magnet powder in the rubber mold. If a magnetic field is momentarily applied to the permanent magnet powder filled in the cavity of the rubber mold with the cavity of the rubber mold open, the powder generates a rapid rotational force with the magnetization, and the powder becomes Scatter outside the mold.

Further, after the magnetic field is applied and before the molding by die press is performed, if the shield of the upper opening of the mold is removed and the closed state of the cavity is broken, the powder is released due to the repulsive force acting between the magnetized powder particles. It jumps out of the rubber mold from the mouth. In the prior application, in order not to cause such an obstacle, the rubber mold is covered with a lid before the pulsed magnetic field is applied, die pressing is performed with the lid covered after the pulsed magnetic field is applied, and then the lid is removed to take out the molded body from the rubber mold. Is proposing that.

In FIG. 7 showing this method, the rubber itself of the rubber mold 10i forms a bottomless mold, and the open bottom of the rubber mold is closed by a part of the ring-shaped rotary die 2a. Therefore, the rotary die 2a constitutes the bottom of the rubber mold. A feeder (not shown) while the rubber mold 10i sequentially rotates and moves on the rotary die 2a.
Filling the rubber mold 10i with the permanent magnet powder by C, C
Of the lid 10u, the electromagnetic coil 4a
A series of operations (A to H) such as pulse orientation by means of, die press by magnetic field die press device 6, removal of lid 10u (performed at position F), removal of a molded product by molded product removal device 12 and the like can be performed. ..

The removed lid 10u is returned to the lid fitting place C by the linear transporter 60. The die press device 6 in the magnetic field is composed of upper and lower punches, an electromagnetic coil and the like. The molded body take-out device 12 includes an arm 14 made of an electromagnet that can be swung around the shaft 23 at a constant angle, and the excited electromagnet causes the green compact 13 having anisotropy to be provided on the rotary die 2a. After absorbing and shaking, when the electromagnet is turned off, the molded body operates so as to be placed on another conveyor 16.

In FIG. 7, 30 is an air piston, 3
1 is an air unit, 32 is an electromagnet, and 33 is an electromagnet excitation power source. The electromagnet 32 moves above the die cavity after taking out the green compact from the die, and is excited by the power source 33 to attract the residual permanent magnet powder remaining in the rubber mold by the magnetic force to clean the rubber mold. Do as needed.

Reference numeral 16 is a conveyor driven by a step motor 17 driven by a control unit 50. After the arm 14 swings above the conveyor 16 from the rotary die 2a and places the green compact 13 on the conveyor 16, the conveyor 16 moves in a direction away from the rotary die 2a. The series of operations is controlled by the control unit 50.

In the circulating path system described with reference to FIG. 7, the steps of attaching and detaching the lid are necessary, and it is necessary to attach the transfer device of the lid 10u between the lid removing position F and the lid attaching position C.

[0014]

When the permanent magnet powder is densely packed, the frictional force acting between the powder particles becomes large.
It is effective to increase the orientation degree by instantaneously applying a magnetic field to crush the powder and perform pre-orientation before die pressing. When applying this momentary magnetic field to the permanent magnet powder, it is necessary to seal the permanent magnet powder in the rubber mold. If a pulsed magnetic field is applied to the permanent magnet powder filled in the cavity of the rubber mold with the cavity of the rubber mold open, the permanent magnet powder generates a rapid rotational force with the magnetization, so that the powder becomes rubber. Scatter outside the mold. If a removable lid is used as in the previous application in order to prevent this scattering, after use of the lid, it has to be returned to the place where the lid before use is put on, and the mechanism of the device therefor becomes complicated. Therefore, it is an object of the present invention to provide a method and an apparatus capable of preventing scattering of permanent magnet powder in an efficient manner.

[0015]

The first aspect of the present invention relates to a method for producing a permanent magnet powder compact having an improved shielding plate in a method of conveying a rubber mold or the like by a circulation path, and one or more recesses or through holes. A rubber mold having a cavity having a bottom and a bottom is filled with a high density of permanent magnet powder or loaded with a preformed body of permanent magnet powder, the cavity of the rubber mold is covered with a shield plate, and the permanent mold is covered with a shield plate. A magnetic field is momentarily applied to the magnet powder, the rubber mold and the permanent magnet powder are compressed by the punch of the die press machine, and the steps of taking out the green compact from the rubber mold are carried out by the orbiting for conveying the rubber mold or the rubber mold and die. Repeatedly repeats the path, seals the orbital path with the shielding plate for the section after the momentary magnetic field is applied, and presses the die. By subsequently punching or shield in position for compression by characterized by sealing the rubber mold.

In the present invention, the application of an instantaneous magnetic field means
A rotational force of the permanent magnet powder is generated in the permanent magnet powder, which is proportional to the strength change (dB / dt) per unit time (t) of the magnetic field (B), and the orientation degree of the green compact is at least after the normal filling. A magnetic field is applied so as to be equal to or higher than the die-press molded permanent magnet powder compact. That is, the high-density filling increases the frictional force between the powder particles, but an instantaneous magnetic field is applied to a level that eliminates the inconvenience caused by the frictional force. Generally, a magnetic field of 5 to 100 kOe is 1 μsec
It is applied as a pulse of 1 sec.

Further, the rubber mold having the bottom is not limited to the case where the integrated rubber mold has the bottom, and may be a separate mold in which the bottom and the other are combined. Further, the bottom may be made of a material harder than the side wall portion, for example, hard rubber or metal.

Further, the pre-formed body means a pre-compressed permanent magnet powder formed into a shape which can be filled in a rubber mold.

The packing density of the permanent magnet powder in the rubber mold in the method of the present invention is 1.2 times or more the natural packing density regardless of the kind of the material of the magnet. The natural packing density is mainly determined by the particle size of the magnet powder. The natural packing density is the apparent density when powder is deposited by free fall. As a standard for this, the apparent density test method is standardized in JIS, but since the fine powder permanent magnet has extremely poor fluidity, it is standardized. It is impossible to measure with the test method used, or a value far apart from the natural packing density obtained with a box feeder is obtained. Therefore, in the present invention, the permanent magnet powder is dropped from the powder pan 27 shown in FIG. 8 into the rubber mold, and the density is the density when the powder is deposited inside the upper frame 28 that prevents the powder from overflowing by rising from the upper end thereof. .. The position of the powder tray 27 is set to be 3.7 times the depth of the cavity of the rubber mold so that the lower end of the tray 27 is separated from the bottom surface of the rubber mold.

Further, according to the first aspect of the present invention, both a method of not sealing the rubber mold at the position where the shielding plate performs the die press and a method of sealing the rubber mold are possible. In the former case, when the permanent magnet powder moves out of the shielding plate, it is necessary to continue to seal with the lower surface of the punch. In the latter case, since the shielding plate maintains the sealed state, press molding is performed at an appropriate timing.

A second aspect of the present invention relates to a method for producing a permanent magnet powder compact that does not use a shielding plate to prevent the scattering of the permanent magnet powder, and a permanent cavity is formed in a cavity having one or more recesses or through holes and a bottom. Magnetic powder is densely packed or a preformed body of permanent magnet powder is loaded, a magnetic field is momentarily applied to the permanent magnet powder in the cavity, and after the magnetic field is momentarily applied, the rubber mold and the permanent magnet powder are removed. It is characterized in that it is pre-compressed at a low pressure and then the rubber mold is conveyed into the die press machine for molding. Here, the low pressure is lower than the pressure finally applied to the permanent magnet powder by the punch of the die press machine to obtain the green compact, but the powder repels each other due to the magnetic force from the opening of the rubber mold and pops out. It is the pressure at which the powder agglomerates to the extent that it does not exist. Popping ease of powder, amount of powder, depending on such remaining磁程of the size and powder mold releasing surface, typically 10 g / cm ² or more is not jumping out of the powder when compressed by pressure.

Therefore, the device for applying such a low pressure may have a simpler pressing means than the die press machine. Since the preliminary pressure is quasi-isotropically applied to the permanent magnet powder through the rubber mold, it is possible to prevent the powder from scattering without disturbing the orientation due to the pulsed magnetic field.

When the second method of the present invention is performed by the circulating path system, the precompression must be performed at the pulse magnetic field application position after applying the pulse magnetic field while sealing the rubber mold with the precompression punch. .. That is, if the position of the mold is changed after applying the pulsed magnetic field, the powder may be scattered or the sealing of the rubber mold may be broken, which is not preferable.
Further, it is preferable that the pre-compression is performed in the absence of magnetic field in order to avoid complication of the device. When precompression is performed in this non-magnetic field, the orientation of the permanent magnet powder may be slightly disturbed. Therefore, when the disorder of the orientation is large, it is necessary to apply a magnetic field during the molding by the die press machine to correct the orientation of the permanent magnet powder. In this case, the pre-compression pressure is as low as possible, for example, preferably 0.1 ton / cm ² or less. If pre-compression is carried out at a pressure higher than this pressure, re-orientation at the time of straightening becomes ineffective because the powder agglomerates too much.

A third aspect of the present invention relates to a method for producing permanent magnet powder which does not use a shielding plate to prevent the scattering of the permanent magnet powder, in which the cavity of the rubber mold is densely filled with the permanent magnet powder or the permanent magnet is used. A powder preform is loaded, the rubber mold is set in the die press, and the magnetic field is momentarily applied to the permanent magnet powder with the open side of the rubber mold covered with an upper punch. It is characterized in that the mold and the permanent magnet powder are pressed.

The momentary magnetic field application in the third method of the present invention is the same as the orientation method in the conventional die press in that the purpose is the orientation of the permanent magnet powder, but the conventional orientation was performed in the static magnetic field. In contrast, the present invention differs in that it uses a pulsed magnetic field. In the previous application, the present inventors found that the permanent magnet powder densely packed in the rubber mold was sufficiently oriented by using a pulsed magnetic field, and then continued the research further, and the orientation by the pulsed magnetic field was possible even in the die press machine. I had the idea of using a punch to prevent the scattering of powder oriented by a pulsed magnetic field.

In the third aspect of the present invention, the die press machine must be equipped with a pulse magnetic field generator. In this case, of course, it is desirable that the installation location of the pulse magnetic field generator is as close as possible to the rubber mold. If a non-conductive and non-magnetic substance such as air or ceramics exists near the cavity of the die of the conventional die press machine, it is possible in principle to install the pulse magnetic field generator at a desired place. However, in a conventional die press machine that performs alignment by a static magnetic field, it is difficult to place the pulse magnetic field generator at a desired position because the punch and other metal jigs are present near the cavity of the die. The magnetic flux generated from the generator becomes an eddy current in such a metal jig and does not reach the inside of the rubber mold sufficiently. Therefore, a space for installing the pulsed magnetic field generator is provided in an ordinary die press machine, and a non-conductive and non-magnetic substance is in direct contact with the rubber mold, or the conductive and / or intervening conductive and / or non-direct contact with the rubber mold. It is preferable to reduce the mass of the magnetic substance. For this purpose, various measures can be taken. For example, the pulse generator can be housed in a non-conductive and non-magnetic box, and this box can be used as a substitute for the stationary punch. Further, the upper portion of the box may be made of rubber having a thickness that does not deform even by compression molding and may also serve as the bottom portion of the rubber mold. Further, the pulsed magnetic field can be concentrated in the rubber mold by constructing the punch, preferably the die and punch as well, of non-conductive and non-magnetic material such as ceramics or high strength plastic.

A fourth aspect of the present invention is to take out, from the rubber mold, a high-density filling section for sequentially packing the permanent magnet powder into the rubber mold at a high density, an instantaneous magnetic field generator, a die press, and a green compact. A molding device comprising a jig and a conveying means for sequentially conveying the rubber mold or the rubber mold and the die to each of the molding devices,
In the section from the position of the instantaneous magnetic field generator to the position of the die press, the upper surface of the conveying means is covered with a shielding plate so that the upper opening of the rubber mold being conveyed is sealed.

[0028]

In the first and fourth aspects of the present invention, the recess of the rubber mold is covered with the shield plate, and the magnetic field is instantaneously applied to the permanent magnet powder covered with the shield plate to prevent the scattering of the permanent magnet powder. To do. Further, by disposing the shielding plate over the section from the position where the instantaneous magnetic field is applied to the position where the die press is performed in the circular path, the permanent magnet powder is exposed in this section and the rubber mold Prevent the danger of jumping out. Further, the shielding plate is continuously provided in the above section so that no gap is formed between the shielding plates. In addition, the position of the shielding plate is determined so that the above-mentioned section is constantly covered by the shielding plate regardless of how many times the rubber mold goes around, and the cover of the rubber mold having the shielding function as in the method of the previous application. It is not necessary to return the position of the die press device in the magnetic field to the position of the instantaneous pulse generator for each turn.

The second aspect of the present invention is to apply a magnetic field to the permanent magnet powder in the cavity instantaneously, and if the shielding of the rubber mold is broken, the powder will be ejected to the outside of the rubber mold by the repulsive force. Since the powder is pre-compressed at low pressure,
The apparent density of the permanent magnet powder is increased, and even if the rubber mold is opened during transportation, it will not jump out of the rubber mold.

The third feature of the present invention is that the punch of the die press machine is used as a lid for preventing permanent magnet powder. That is, if the upper and lower punches are arranged in contact with the upper and lower surfaces of the permanent magnet powder, or if the die cavity is covered even when the upper punch is not in contact with the permanent magnet powder, the instantaneous magnetic field causes permanent magnet powder. When added to the powder, the powder does not hit the punch and fly out of the die cavity.

The present invention will be specifically described with reference to the following examples.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 corresponds to the first and fourth embodiments of the present invention and is a sectional view taken along the line I--I of FIG. 2. FIG. 2 is a plan view of the permanent magnet powder compact manufacturing apparatus of the present invention. It is a figure. In the figure, the same elements as those in FIG. 7 are denoted by the same reference numerals. In the figure,
Reference numeral 20 is a die, 34 is a backup plate made of a ring of hard rubber, 35 is an electromagnetic coil for applying an orientation magnetic field to permanent magnet powder, 40 is a rubber mold carrier corresponding to a circulating path and a conveying means on the lower side. It is a bottom plate that is slidably supported by. The bottom plate 40 includes the upper and lower punches 1a and 1b.
In the area (2), a part of the die is formed, and also the bottom surface that supports the rubber mold 10 being conveyed in the circulating path is also formed. 42
Is an electromagnetic coil that applies an instantaneous magnetic field to the permanent magnet powder, 43
Is a shield plate.

At the position A, the permanent magnet powder 5 is densely packed in the rubber mold 10 by a pusher, a vibration machine or the like in the high density packing portion 46 (FIG. 2). Reference numeral 44 shown in the position B indicates the electromagnetic coil 42, a magnetic pole (not shown), a power source,
A pulsed magnetic field generator including a capacitor is shown. The shield plate 43 reaches the position of the die press device 6 in the magnetic field along the carrier 2. The shield plate 43 is held in a horizontal position by being supported by several columns 45 that stand upright on the floor surface of the building, and the carrier 2 covers the shield plate 43 in the vertical position.
It is adjusted to slide with respect to. Therefore,
When the carrier 2 circulates, the rubber mold 10 enters the lower part of the shield plate 43 which is stationary at the position shown in the figure, and the rubber mold 10 has a momentary magnetic field with its opening being sealed by the shield plate. Add to powder 5.

Subsequently, the rubber mold 10 moves along with the rotation of the carrier 2 in the direction of the arrow while maintaining the sealed state, and reaches the positions B to C. At this time, the lower surface of the upper punch 1a is at the same height as the lower surface of the shielding plate 43, and the lower punch 1a
The upper surface of b is at the same height as the upper surface of the bottom plate 40, and is waiting for the rubber mold 10 to reach C. Rubber mold 1
When 0 is transferred to the upper surface of the lower punch 1b, once the carrier 2
Stops the rotation and moves the rubber mold 10 to the upper and lower punches 1a,
It is sandwiched between 1b, then descends, and press molding is performed in the die 20. After that, the upper and lower punches 1a and 1b rise,
Since the carrier 2 is returned to the previous position and the rotation of the carrier 2 is restarted, the rubber mold 10 is placed on the bottom plate 40 again,
Next, the position D is reached.

Although the electromagnetic coil 42 is provided laterally below the rubber mold 10 in FIG. 1, it may be provided directly above the rubber mold 10. Further, when a sufficient orientation can be obtained by the electromagnetic coil 42, the electromagnetic coil 35 of the die press device may be omitted. Further, although only one cavity is shown in the rubber mold 10 in FIG. 1, even if two or more cavities are formed, it is possible to perform processing such as magnetic field application as described above. Similarly, if the outer ring-shaped portion of the rubber mold shown as 10 is made of die steel, it becomes an embodiment in which the rubber mold and the die are orbited.

The carrier 2 may be a rotary die, and the die may be rotationally conveyed together with the rubber mold. In this case, the die may be closed as shown in FIG. 3 and compression molding may be performed only by the upper punch 1a. Further, as shown in FIG.
The upper punch may reach the position where it should be and seal the die cavity, and the lower punch 1b on the opposite side may push up the rubber mold 10. In the case of FIG. 4, the shield plate 43 is formed by an upper punch (not shown).
While reinforcing the upper punch and the shield plate 43 and the lower punch 1
The compression may be performed between b. As shown in the right half of FIG. 5, the inner peripheral side of the pulse coil 42 is attached to the plastic die 20b.
May be The mold 10 is attached to the upper and lower punches 48a, 48
Plastic die 20 from carrier 2 sandwiched in b
Alternatively, the magnetic field may be lowered to b, a pulse magnetic field may be applied to the magnet powder from the pulse coil 42, and then the powder may be compressed in the plastic die 20b.

FIG. 5 shows a second embodiment of the present invention, and FIG.
The same elements as are given the same reference numerals. In the figure, 20a is a die. 48a and 48b are low pressure and permanent magnet powder 5
Is a punch for compressing. The operation is the same as that of the upper and lower punches 1a and 1b of the die press machine described with reference to FIG. 1, and the operation of the carrier 2 and the upper and lower punches 1a and 1b is also the same as that described with reference to FIG. Figure 5
In the embodiment shown in FIG. 4, the pressure applied by the punches 48a and 48b may be low, so that the punch 4 is made of plastic or the like.
8a, 48b and die 20a can be constructed.
Further, the punch 48 may be only one as shown in FIGS. 3 and 4. Although 49 is a guide for guiding the punch 48a, it may be omitted.

With the punches 48a and 48b shown in FIG.
After sealing the rubber mold 10 and momentarily applying a magnetic field, the rubber mold 10 and the permanent magnet powder are lightly compressed at that position by the punches 48a and 48b to aggregate the powder. After that, the carrier 2 is rotated to move the rubber mold 10 out of the guide 49. At this time, the permanent magnet powder 5 is
Do not jump out from the external opening of the rubber mold 10.
Therefore, it is not necessary to cover the rubber mold 10 with the shielding plate.

When the preforming die 20a which is a part of the carrier 2 and moves integrally with the carrier 2 is made of ceramic or plastic, the disorder of the orientation is reduced.
This is because the magnetic flux generated by the instantaneous magnetic field application performed before the preforming does not become an eddy current in the die, and the subsequent preliminary compression of the permanent magnet powder 5 is performed isotropically. .. It is preferable to lower the pressure by the punch 48 when it is desired to correct the orientation during the subsequent die pressing even though the orientation is less disturbed.

FIG. 6 shows a third embodiment of the present invention, and FIG.
The same elements as are given the same reference numerals. In this embodiment, a bottom plate 25 made of ceramics or resin is used at the bottom of an ordinary one-sided die press machine, and a pulse magnetic field generator 26 is embedded in the bottom plate 25. Therefore, almost all the magnetic flux from the pulse magnetic field generator 26 is applied to the permanent magnet powder in the rubber mold 10. When the magnetic field is applied, the upper punch 1a seals the rubber mold 10, so that scattering of powder can be avoided.

[0040]

As described above, according to the present invention, since the permanent magnet in the rubber mold does not jump out of the rubber mold after the momentary magnetic field is applied, a fixed amount of the permanent magnet powder is pressed. Not only does the density of the green compact become constant, but the magnetic properties of the magnet product that has been sintered or resin-impregnated also become constant.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an instantaneous magnetic field application unit and a die press machine of an orbiting type green compact manufacturing apparatus, showing a first embodiment of the present invention.

FIG. 2 is a plan view of an orbiting green compact manufacturing apparatus.

FIG. 3 is an explanatory diagram of a method for molding a green compact with a single-closing die.

FIG. 4 is an explanatory diagram of a molding method in which the shielding plate has both the function of shielding and the function of the upper punch.

FIG. 5 is a view corresponding to FIG. 1 and showing a second embodiment of the present invention.

FIG. 6 is a view corresponding to FIG. 1 and showing a third embodiment of the present invention.

FIG. 7 is a plan view of an orbiting type green compact manufacturing apparatus.

FIG. 8 is an explanatory diagram of a natural filling method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 punch 2 carrier 4 electromagnetic coil 6 die press device in a magnetic field 10 rubber mold 12 molded product unloading device 13 powder compact 14 arm 16 conveyor 17 step motor 20 die 23 shaft 25 bottom plate 26 pulse magnetic field generator 30 air piston 31 air unit 32 electromagnet 33 power supply 34 backup plate 35 electromagnetic coil 40 bottom plate 42 electromagnetic coil 43 shield plate 44 pulse magnetic field generator 45 pillar 46 high-density filling unit 50 control unit

Claims (4)

[Claims] 1. A rubber mold having a cavity having one or more recesses or through holes and a bottom, wherein the cavity is densely filled with permanent magnet powder or a preformed body of permanent magnet powder is loaded, and The cavity is covered with a shielding plate, a magnetic field is momentarily applied to the permanent magnet powder covered with the shielding plate, the rubber mold and the permanent magnet powder are compressed by a punch of a die press machine, and the green compact is taken out from the rubber mold. The steps are sequentially repeated in a rubber mold or a circular path for conveying the rubber mold and the die, and the circular path is sealed with the shielding plate over a section after the momentary magnetic field application, and compressed by the die press. At the position, the rubber mold and the permanent magnet powder are compressed by the punch while sealing the rubber mold with the punch or the shielding plate. A method for producing a permanent magnet green compact characterized by carrying out. 2. A rubber mold having one or more recesses or through holes and a cavity having a bottom is densely filled with permanent magnet powder or loaded with a preformed body of permanent magnet powder, and A magnetic field is momentarily applied to the permanent magnet powder, and after the magnetic field is momentarily applied, the rubber mold and the permanent magnet powder are pre-compressed at a low pressure, and then the rubber mold or the rubber mold and die are transferred into a die press machine. A method for producing a permanent magnet powder compact, which comprises molding. 3. A rubber mold having one or more recesses or through-holes and a cavity having a bottom is densely filled with permanent magnet powder or loaded with a preformed body of permanent magnet powder, and the rubber mold is formed. Set it in the die press machine, momentarily apply a magnetic field to the permanent magnet powder with the open side of the rubber mold covered with the upper punch, and then pressurize the rubber mold and the permanent magnet powder with the upper and lower punches. A method for producing a characteristic permanent magnet powder compact. 4. A high-density filling section for sequentially packing the permanent magnet powder into the cavity of the rubber mold with a high density, an instantaneous magnetic field generator, a die press, and a jig for taking out the green compact from the rubber mold. Comprising a molding device consisting of, and having a conveying means for sequentially conveying the rubber mold or the rubber mold and die to each of the molding device,
In the section from the position of the instantaneous magnetic field generator to the position of the die press, the upper surface of the conveying means is covered with a shielding plate so that the upper opening of the rubber mold being conveyed is sealed. Manufacturing equipment for magnet powder compacts.