JP4470112B2 - Molding equipment - Google Patents

Description

  The present invention relates to a molding apparatus that press-molds rare earth magnet raw material powder while applying a magnetic field, and relates to an improvement of a molding apparatus of an orthogonal magnetic field molding system that molds a magnetic field application direction and a pressurizing direction as directions orthogonal to each other. .

  When manufacturing rare earth sintered magnets such as neodymium iron boron and samarium cobalt, the rare earth magnet raw material powder is pressed into a predetermined shape and then sintered to obtain a rare earth sintered magnet having a predetermined shape. I am doing so. In this case, the pressure molding is generally performed by powder compaction in a uniaxial direction using a die and a punch of a mold. For the purpose of obtaining high orientation and high magnetic properties, a molding method in a magnetic field is performed in which the compacting is performed while applying a magnetic field.

  Here, the in-magnetic field forming method includes an orthogonal magnetic field forming method in which the magnetic field application direction and the compacting direction are orthogonal, and a parallel magnetic field forming method in which the magnetic field application direction and the compacting direction are the same direction. It is the reality. For example, in order to produce a flat rare earth sintered magnet having a large magnetic pole area and a small thickness, it is necessary to form the rare earth magnet raw material powder into a flat plate shape. When trying to form such a shape by the orthogonal magnetic field forming method, the width of the opening of the die must be narrowed, and it becomes deeper in the depth direction than the area of the opening. Uniform filling of the raw powder into the die becomes difficult. If the filling is performed uniformly, the filling time becomes long and the mass productivity decreases. Therefore, for forming in such a shape, a parallel magnetic field forming method that can shorten the filling time and widen the opening of the die that facilitates uniform filling must be employed.

  However, the degree of orientation of the molded body obtained by the parallel magnetic field forming method has a drawback that it is lower than that obtained by the orthogonal magnetic field forming method. In the parallel magnetic field forming method, since the pressing direction and the magnetic field application direction are parallel, it is considered that the orientation of the raw material powder due to the magnetic field application is disturbed by the pressurization and the degree of orientation is lowered. If the degree of orientation of the compact is low, the residual magnetic flux density of the rare earth sintered magnet obtained after sintering is lowered, and the maximum energy product is also lowered accordingly. In fact, in the magnet using the parallel magnetic field forming method for forming, the residual magnetic flux density is reduced by about 3 to 8% as compared with the magnet formed by the orthogonal magnetic field forming method.

  Under such circumstances, attempts have been made to improve the molding method in a magnetic field, and the method described in Patent Document 1 is one of them. In the method described in Patent Document 1, first, the upper punch is sufficiently raised, and a predetermined fine powder is supplied to a molding space formed by the left and right compacting dies and the lower punch. At this time, since the supply port of the fine powder is wider than the conventional orthogonal magnetic field forming method, uniform supply can be performed. After the fine powder supply is completed, when the upper punch is lowered to a predetermined position, a magnetic field is applied by the magnetic field generating coil, and the left and right compaction punches are compacted and molded.

The technique described in Patent Document 1 is a kind of orthogonal magnetic field forming method, which facilitates filling of raw material powder with the direction in which a mold opening can be widely taken upward, applies a magnetic field in the vertical direction, and applies pressure. By driving the punch for powdering in the horizontal direction, the magnetic field application direction and the compacting direction are orthogonal to each other. That is, the invention described in Patent Document 1 attempts to realize both easy filling of the raw material powder in the parallel magnetic field forming method and high orientation in the orthogonal magnetic field forming method.
JP-A-7-173505

  The idea of the invention described in Patent Document 1 can be said to be reasonable from the viewpoint of easily performing molding with high orientation. In particular, if the upper punch (upper die) and the lower punch (lower die) are made of a ferromagnetic material, it is possible to assemble a closed magnetic path with a small gap by using these dies, and it is very possible to suppress leakage magnetic flux. It is possible to apply a magnetic field with high efficiency.

  However, in this case, the mold is relatively easier to pass magnetic flux than the rare earth magnet raw material powder to be molded. Therefore, when the magnetic field is applied, the mold (strongly present around the molding space, in particular). There is a problem that magnetic flux is attracted to the magnetic material), and orientation defects due to magnetic field bending tend to occur in the peripheral portion of the molded body.

  The present invention has been proposed in view of the above problems, and a molding apparatus capable of suppressing the occurrence of magnetic field bending in a molding space and capable of molding a molded body having no orientation defect particularly in the outer peripheral portion. The purpose is to provide.

In order to achieve the above-described object, the molding apparatus of the present invention has a mold made of a ferromagnetic material disposed above and below the molding space, and moves in a substantially horizontal direction with respect to the mold, thereby rare earth magnet raw material powder. One or more punches that pressurize in a substantially horizontal direction, and magnetic field applying means for applying a magnetic field in a substantially vertical direction to the rare earth magnet raw material powder in the molding space through the mold, and the ferromagnetic The mold made of the material is divided into two vertically, and the punch is inserted into the lower mold to form a groove portion forming the molding space, and both side portions of the groove portion of the lower mold and the At least a tip portion of the punch is made of a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less. Alternatively, a mold made of a ferromagnetic material is disposed above and below the molding space, and one or more punches that move in a substantially horizontal direction with respect to the mold and press the rare earth magnet raw material powder in a substantially horizontal direction; Magnetic field applying means for applying a magnetic field in a substantially vertical direction to the rare earth magnet raw material powder in the molding space through the mold, and the mold is formed integrally in the vertical direction and is formed to penetrate in the horizontal direction. A molding space into which the punch is inserted, and at least a tip portion of the punching space of the mold and the punch is made of a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less. It is characterized by being.

  In a molding apparatus in which molds made of a ferromagnetic material are arranged above and below a molding space, the mold is composed of a ferromagnetic material, and a closed magnetic path is configured with a small gap (a gap corresponding to the height of the molding space). Therefore, it is possible to efficiently apply a magnetic field, and high orientation is realized in the molded body to be molded.

  However, when the molding space is viewed in a horizontal plane, a ferromagnetic material is arranged around the molding space, and magnetic characteristics (for example, magnetic permeability) of the rare earth magnet raw material powder filled in the molding space. The difference causes magnetic field bending. Since a ferromagnetic material having a magnetic property superior to that of the rare earth magnet raw material powder is arranged around the molding space, the magnetic flux is attracted to the mold side particularly around the molding space, and the flow of magnetic flux is not parallel. When a magnetic field is applied in such a state, naturally, the rare earth magnet raw material powder is also oriented following the flow of the non-parallel magnetic flux, and orientation failure occurs in this portion.

  Therefore, in the present invention, the magnetic field bending is eliminated by arranging a non-magnetic material or a weak magnetic material around the molding space. If the molding space is viewed in a horizontal plane and a non-magnetic or weak magnetic material is placed around it, the molding space and its surroundings are almost magnetically equivalent, and the flow of magnetic flux is made uniform in the in-plane direction. Is done. As a result, the direction of the magnetic flux becomes almost parallel in the forming space and its peripheral portion, and magnetic field bending does not occur. For this reason, shaping | molding of the molded object without an orientation defect is implement | achieved.

  For example, Japanese Patent No. 3526493 discloses that the orientation is improved by eliminating the bending of the magnetic field. However, in the idea so far including this patent publication, the main focus is on eliminating the magnetic field bending formed in such a manner that the magnetic flux is attracted in the molding space. This is because the permanent magnet powder in the molding space is more likely to pass magnetic flux than the surroundings. Therefore, a magnetic material is arranged around the molding space as a countermeasure. The present invention has been devised for the purpose of eliminating magnetic field bending caused by a phenomenon completely different from the prior art in a molding apparatus of a type completely different from the prior art described in the above-mentioned patent publications. The technical contents are significantly different from the prior art.

  In addition, in a molding apparatus in which dies made of a ferromagnetic material are arranged vertically in the vertical direction, sandwiching rare earth magnet raw material powder during filling is also a major problem in addition to the magnetic field bending. In the molding apparatus of the present invention, there is a possibility that defective molding due to the biting of the raw material powder occurs due to the structure. For example, if the remanent state of the mold is poor, that is, if the mold is magnetized, the raw material powder is magnetically adsorbed and remains around the molding space, biting it in the next molding, It may cause defects, density defects, cracks, and the like.

  This is solved by the invention according to claim 2 of the present application, characterized in that a nonmagnetic material or a weak magnetic material is arranged in a portion contacting the upper and lower sides of the molding space. The material powder is attracted by the residual magnetism on the upper surface or the lower surface of the molding space in the mold. Therefore, if this portion is made of a non-magnetic material or a weak magnetic material, the magnetic gap is expanded and the influence of the residual magnetism is attenuated rapidly.

  According to the molding apparatus of the present invention, first of all, since the direction of the magnetic field to be applied is the orthogonal direction (vertical direction) to the pressure molding direction (horizontal direction), filling of raw material powder in the parallel magnetic field molding method Therefore, it is possible to achieve both high orientation in the orthogonal magnetic field molding method, and it is possible to produce a high-performance rare earth sintered magnet with high productivity. Second, a mold made of a ferromagnetic material is arranged vertically in the vertical direction to form a closed magnetic path with a narrow gap, and a magnetic field is directly applied through these molds, so that a molding space is formed. A very strong magnetic field can be applied, and a higher orientation can be realized in the molded article to be molded.

  Thirdly, since a non-magnetic material or a weak magnetic material is arranged around the molding space, it is possible to eliminate the magnetic field bending around the molding space and to suppress the occurrence of orientation failure in the molded body to be molded. it can. Fourth, by arranging non-magnetic or weak magnetic materials in the upper and lower parts of the molding space, it is possible to prevent biting of the raw material powder during molding, resulting in dimensional defects, density defects, cracks. Etc. can be suppressed.

  Hereinafter, a molding apparatus to which the present invention is applied will be described in detail with reference to the drawings.

(First embodiment)
The molding apparatus of the present embodiment is a molding apparatus that performs molding by an orthogonal magnetic field molding method. FIG. 1 shows a schematic configuration of a molding apparatus according to the present embodiment. The mold structure includes a vertical mold, that is, an upper mold 1 divided into upper and lower parts, a lower mold 2, and a movable in a horizontal direction. The left punch 3 and the right punch 4 are combined.

  Here, the upper mold 1 and the lower mold 2 are for forming a closed space at the time of molding. For example, when molding a plate-shaped molded body, the surface of the main surface having a large area is formed. Do. Therefore, the lower surface of the upper mold 1 (the surface facing the lower mold 2) is a flat surface.

  On the other hand, the lower mold 2 is for chamfering the main surface on the opposite side of the molded body as in the case of the upper mold 1 described above, but guides the movement (slide) of the left punch 3 and the right punch 4. A slide groove 2a is formed. The slide groove 2a corresponds to a groove portion constituting the molding space, and the main surface on the opposite side of the molded body is chamfered by the bottom surface 2b. Further, the width and depth of the slide groove 2a are substantially the same as the width and thickness of the left punch 3 and right punch 4, thereby determining the width and thickness of the molded body.

  The upper mold 1 and the lower mold 2 are both made of a ferromagnetic material, for example, iron, and the magnetic field generated by the magnetic field generator is efficiently guided to the molding space and filled in the molding space. It is possible to apply a very strong magnetic field to the rare earth magnet raw material powder. Therefore, it can be said that the configuration is extremely efficient in terms of magnetic field orientation.

  The left punch 3 and the right punch 4 correspond to pressurizing means, move in the horizontal direction in the slide groove 2a, and are filled in the space between the upper mold 1 and the lower mold 2 Press-mold the raw material powder. Therefore, the pressing force is applied in the horizontal direction during molding. In press molding, pressurization may be performed with one punch, but pressurization with both punches is more preferable because pressure is uniformly applied to the raw material powder.

  At the time of molding, the planar shape of the molded body to be molded is determined by the shape of the tip of the left punch 3 or right punch 4, and in the case of the tip shape of the left punch 3 or right punch 4 shown in FIG. Because of the shape, the planar shape is molded into a rectangular shaped body. For example, in the case of forming a disk-shaped molded body having a circular planar shape, the shapes of the front end surfaces of the left punch and the right punch may be arcuate (concave). In the example shown in FIG. 1, the left punch 3 and the right punch 4 are also plate-shaped (the slide groove 2 a is a rectangular groove) so that the cross section is rectangular (the molded body is a flat plate). When the cross section is circular (the molded body is cylindrical), the main surfaces of the upper mold 1 and the lower mold 2 are arcuate (the slide groove 2a is an arcuate groove) and the left punch 3 The tip shape of the right punch 4 may be circular.

  The molding state in the molding apparatus of this embodiment is shown in FIG. As shown in FIG. 2, rare earth magnet raw material powder is filled in the space (molding space C) in which the upper mold 1 and the lower mold 2 arranged on the upper and lower sides, and the left and right punches 3 and 4 are closed. It is pressure formed. Note that FIG. 2 shows the molding apparatus viewed from the insertion direction of the left and right punches 3 and 4, and therefore the left and right punches 3 and 4 are not shown in FIG. 2.

  Here, the upper mold 1 and the lower mold 2 are respectively provided with magnetic field generating coils 5 and 6 for applying a magnetic field in the vertical direction, and a magnetic field is applied to the molded body in the vertical direction during molding. Applied. That is, in the molding state, a closed magnetic path is constituted by the upper mold 1 and the lower mold 2 made of a ferromagnetic material, and a magnetic field is applied with the molding space as a magnetic gap g.

  At this time, around the molding space C, the upper mold 1 and the lower mold 2 are in contact with each other and are magnetically short-circuited. As a result, as schematically shown in FIG. 3A, the flow of magnetic flux (indicated by an arrow in the drawing) is drawn toward the lower mold 2 made of a ferromagnetic material in the periphery of the molding space C. Magnetic field bending occurs in the shape. The rare earth magnet raw material powder is oriented according to the flow of magnetic flux in the molding space C. Therefore, the occurrence of the magnetic field bending leads to poor orientation of the molded body to be molded.

  This is because the lower mold 2 made of a ferromagnetic material has better magnetic flux passage than the rare earth magnet raw material powder filled in the molding space C, and the inside of the molding space C (rare earth magnet raw material powder) and its surroundings. This is due to the difference in magnetic characteristics. Therefore, in the present invention, as shown in FIG. 4, at least a part of a peripheral portion (colored region in the drawing) in the horizontal plane of the molding space C is made of a nonmagnetic material, and magnetic nonuniformity in the horizontal plane is formed. This will be solved. However, since this part also has a function as a mold, the nonmagnetic material to be used is preferably made of a cemented carbide such as a so-called super steel material. The non-magnetic material is preferably disposed in the peripheral portion in the horizontal plane of the molding space C, but the same applies to a weak magnetic material having weak magnetism (saturation magnetic flux density of about 0.8 T or less). The effect of can be obtained.

  When the peripheral portion in the horizontal plane of the molding space C is a non-magnetic material (weak magnetic material), as shown in FIG. 4, both side portions 2c of the slide groove 2a of the lower mold 2 are made of a non-magnetic material or a weak magnetic material. In this case, the left and right punches 3 and 4 are preferably made of a nonmagnetic material and a weak magnetic material.

  By arranging the nonmagnetic material (weak magnetic material) around the molding space C as described above, the magnetic non-uniformity is eliminated. As a result, as shown in FIG. 3B, the direction of the applied magnetic field becomes parallel and uniform in the molding space C and its peripheral portion, and alignment defects due to magnetic field bending are eliminated.

  In the molding apparatus having the above-described configuration, a pressing force is applied in the horizontal direction by the left punch 3 and the right punch 4 at the time of molding. Therefore, an orthogonal magnetic field molding method in which the magnetic field application direction and the dusting direction are orthogonal to each other. Thus, molding is performed. Further, in the mold structure, the rare earth magnet raw material powder raises the upper mold 1 and fills the space formed by the slide groove 2 a of the lower mold 2, the left punch 3 and the right punch 4. However, the area of the opening can be widened corresponding to the main surface of the molded body, and filling can be performed easily.

However, when the upper mold 1 is remanent at the time of filling, the raw material powder filled when the upper mold 1 is lowered and brought close to the lower mold 2 is sucked and sandwiched between the molds. It can be a cause. Therefore, normally, in this type of molding apparatus, the upper mold 1 is demagnetized (demagnetized) prior to the filling of the raw material powder. However, since the magnetic properties of the molded body and the mold are different, When the demagnetization conditions are met, the demagnetization of the mold becomes insufficient. For example, as shown in FIG. 5, if a reverse magnetic field having a predetermined magnitude is applied to a magnetized molded body, the residual magnetism is erased. However, the hysteresis is different between the molded body and the mold, and even if the same reverse magnetic field as that of the molded body is applied to the remanent mold, the magnetization does not become zero but −M ₁ magnetization remains.

  In order to eliminate such a phenomenon, as shown in FIG. 6, a plate-like nonmagnetic material (weak magnetic material) 1a is pasted on the surface of the upper mold 1 facing the lower mold 2 (for example, It is also effective to braze with silver solder or the like. Similarly, the lower die 2 is also enlarged by a non-magnetic material (weak magnetic material), and the peripheral portion 2d of the slide groove 2a including the bottom surface 2b of the slide groove 2a is made of a non-magnetic material (weak magnetic material). ).

  As described above, most of the upper mold 1 and the lower mold 2 are made of a ferromagnetic material such as iron so that an effective magnetic field can be applied when a magnetic field is applied. Therefore, if there is residual magnetism, the raw material powder is attracted on the surfaces of the upper mold 1 and the lower mold 2 and the above problem occurs. As described above, if the opposing surfaces of the upper mold 1 and the lower mold 2 are made of a nonmagnetic material (weak magnetic material), a magnetic gap is generated correspondingly, and the distance (of the nonmagnetic material) With the thickness), the effect of residual magnetism attenuates rapidly.

  Therefore, the thickness of the nonmagnetic material 1a in the upper mold 1 and the thickness of the peripheral portion 2d in the lower mold 2 are preferably as thick as possible from the viewpoint of avoiding the influence of the residual magnetism, but if they are too thick It becomes difficult to apply a magnetic field efficiently during molding. Considering this, it is preferable that the thickness of the bottom portion of the slide groove of the nonmagnetic material 1a or the peripheral portion 2d is 2 mm to 30 mm.

  The same applies to each embodiment described later, but the molding apparatus of the present invention is applied to the production of a rare earth sintered magnet. The rare earth sintered magnet to be manufactured is mainly composed of rare earth element R, transition metal element T and boron B, and is extremely excellent in magnetic properties. High performance can be realized.

  The magnet composition of the rare earth sintered magnet to be manufactured is not particularly limited, and may be arbitrarily selected according to the application. For example, the rare earth element R specifically means Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu. 1 type (s) or 2 or more types can be used. Among these, it is preferable that the main component as the rare earth element R is Nd because it is abundant in resources and relatively inexpensive. Moreover, as the transition metal element T, any conventionally used transition metal element can be used. For example, one or more of Fe, Co, Ni and the like can be used. Among these, Fe and Co are preferable from the viewpoint of sinterability, and it is particularly preferable to mainly include Fe from the viewpoint of magnetic characteristics. In addition to the rare earth element R, transition metal element T, and boron B, for the purpose of improving characteristics such as coercive force, an element such as Al may be added. In addition to these elements, for example, carbon and oxygen may be contained as inevitable impurities or trace additives.

  For the production of the rare earth sintered magnet as described above, a powder metallurgy method is used. The manufacturing process includes, for example, an alloying process, a coarse pulverization process, a fine pulverization process, a forming process in a magnetic field, a sintering process, and an aging process. , A machining process, a film forming process, and the like.

  The forming apparatus and the forming method of the present invention are applied to the forming step in a magnetic field, and form rare earth magnet raw material powder into a predetermined shape in a state of being oriented in a predetermined direction. The formed molded body is subjected to the next sintering step, and sintering is performed.

  7a to 7d show a procedure for forming rare earth magnet raw material powder using the forming apparatus of the present embodiment. 7A to 7D show an upper coil 5 and a lower coil 6 that apply a magnetic field at the time of molding, and a magnetic field is applied in the vertical direction (up and down direction in the figure) by these coils 5 and 6. A support table 8 is provided adjacent to the lower mold 2, and the upper surface of the support table 8 forms the same plane as the bottom surface 2 b of the slide groove 2 a of the lower mold 2.

  When forming the rare earth magnet raw material powder, first, as shown in FIG. 7a, the upper mold 1 is raised, and the feeder box 9 in which the raw material powder 10 is accommodated and the bottom surface is opened is reciprocated. The powder 10 is filled into a space surrounded by the lower die 2 and the left and right punches 3 and 4 so as to be in a so-called slit state. At this time, the opening area of the space surrounded by the lower mold 2 and the left and right punches 3 and 4 is large corresponding to the main surface of the flat molded body. For example, a flat plate-shaped molded body is formed. It can be made much wider than the opening in the case where it is arranged in the vertical direction, and can also be made shallower in the depth direction, so that the raw material powder 10 can be filled easily. Further, demagnetization of the upper mold 1 prior to filling of the raw material powder 10 is the same as in the first embodiment.

  Next, as shown in FIG. 7 b, the upper mold 1 is lowered until the lower surface of the upper mold 1 hits the upper surface of the lower mold 2, and the upper mold 1, the lower mold 2, and the left and right punches 3, 4 A closed space is formed. The raw material powder 10 filled in the above process is accommodated in this closed space.

  Subsequently, as shown in FIG. 7c, a magnetic field is applied to the raw material powder 10 in the vertical direction by the upper coil 5 and the lower coil 6 in this state (a state in which the raw material powder 10 is accommodated in the closed space). While applying a magnetic field, the left punch 3 is moved in the right direction in the figure and the right punch 4 is moved in the left direction in the figure, and the filled raw material powder 10 is pressed from the left and right to be compressed. Thereby, the molded object 11 of a predetermined shape is formed. Further, in order to promote the magnetic field orientation of the raw material powder 10, the left punch 3 and the right punch 4 are operated in the direction opposite to the pressurizing direction before the magnetic field is applied, and the left space 3 and the right punch are increased after increasing the closed space volume. 4 may be used for pressurization. The bulk density at that time is preferably 20 to 30% of the theoretical density. The magnetic field application direction is a direction orthogonal to the pressurizing direction by the left and right punches 3 and 4, and therefore, orthogonal magnetic field shaping is performed.

  In the compaction, the pressure applied by the left and right punches 3 and 4 may be appropriately set according to the type, size, shape and the like of the raw material powder 10 to be used, but is usually about 30 MPa to 200 MPa. Similarly, the strength of the magnetic field to be applied may be appropriately set according to the raw material powder 10 to be used, and may be set to about 0.8T to 2.0T, for example.

  After forming the molded body 11, as shown in FIG. 7d, the molded body 11 is horizontally moved in the left direction in the figure while being sandwiched between the left punch 3 and the right punch 4, and the upper mold 1 and the lower mold 2 are moved. Remove from the closed space. At this time, the molded body 11 is moved horizontally while being in contact (supported) with the bottom surface 2b of the slide groove 2 of the lower mold 2 or the upper surface of the support table 8, and an inadvertent force is exerted at the time of removal. In addition, a situation in which the molded body 11 is damaged is avoided. Further, when the molded body 11 is moved horizontally, a certain amount of pressure is applied to the molded body 11 by the left and right punches 3, 4, or a slide taper 2 a of the lower mold 2 is provided with a taper. Further, it is possible to suppress the occurrence of a laminate crack at the time of taking out.

  As described above, according to the molding apparatus of the present embodiment, it is possible to efficiently take out a good molded body without cracks from the mold, and there is an effect that continuous molding is possible.

(Second Embodiment)
In the molding apparatus of the present embodiment, the lower punch 12 is incorporated in the lower mold 2 as shown in FIG. The lower punch 12 is movable relative to the lower mold 2 in the vertical direction, and is fixed at a position that forms the same plane as the bottom surface 2b of the slide groove 2a of the lower mold 2 at the time of molding. Functions as a molding surface. After the molding, the lower punch 12 is raised while the molded body is sandwiched between the upper molds 1 or the lower mold 2 is lowered so that the molded body is supported by the upper surface of the lower punch 12. Taken from.

  In this case, it is preferable that the shape and size of the upper surface of the lower punch 12 be substantially the same as or slightly larger than the shape and size of the lower surface of the molded body after molding. Thereby, it can take out from a metal mold | die rapidly, without damaging a molded object. Although the size of the upper surface of the lower punch 12 can be made slightly smaller than the size of the lower surface of the molded body, the shape and size of the upper surface of the lower punch 12 are the same as those of the lower surface of the molded body after molding. If it is significantly smaller than the shape and size, there is a possibility that a force is locally applied to the molded body at the time of removal, and the molded body may be damaged.

  8a to 8d show a procedure for forming rare earth magnet raw material powder using the forming apparatus of this embodiment. In forming the rare earth magnet raw material powder, first, as shown in FIG. 8a, the upper mold 1 is raised, and the feeder box 9 in which the raw material powder 10 is accommodated and the bottom surface is opened is reciprocated. The powder 10 is filled into a space surrounded by the lower die 2 and the left and right punches 3 and 4 so as to be in a so-called slit state. At this time, the opening area of the space surrounded by the lower mold 2 and the left and right punches 3 and 4 is large corresponding to the main surface of the flat molded body. Compared with the opening in the case of disposing, it can be remarkably widened and can also be shallow in the depth direction, so that the raw material powder 9 can be filled easily. 8A, the lower punch 12 is lowered to a position where the upper surface is flush with the bottom surface 2b of the slide groove 2a of the lower mold 2. In addition, the demagnetization of the upper mold 1 prior to the filling of the raw material powder 10 is the same as in the previous embodiments.

  Next, as shown in FIG. 8 b, the upper mold 1 is lowered until the lower surface of the upper mold 1 hits the upper surface of the lower mold 2, and the upper mold 1, the lower mold 2, and the left and right punches 3, 4 A closed space is formed. The raw material powder 10 filled in the above process is accommodated in this closed space.

  Subsequently, as shown in FIG. 8c, a magnetic field is applied to the raw material powder 10 in the vertical direction by the upper coil 5 and the lower coil 6 in this state (a state in which the raw material powder 10 is accommodated in the closed space). While applying a magnetic field, the left punch 3 is moved in the right direction in the figure and the right punch 4 is moved in the left direction in the figure, and the filled raw material powder 10 is pressed from the left and right to be compressed. Thereby, the molded object 11 of a predetermined shape is formed. Further, in order to promote the magnetic field orientation of the raw material powder 10, the left punch 3 and the right punch 4 are operated in the direction opposite to the pressurizing direction before the magnetic field is applied, and the left space 3 and the right punch are increased after increasing the closed space volume. 4 may be used for pressurization. The bulk density at that time is preferably 20 to 30% of the theoretical density. The magnetic field application direction is a direction orthogonal to the pressurizing direction by the left and right punches 3 and 4, and therefore, orthogonal magnetic field shaping is performed.

  After molding the molded body 11, as shown in FIG. 8d, the upper mold 1 is raised, then the lower punch 12 is pushed up, and the molded body 11 is taken out from the lower mold 2. Since the lower surface having a large area of the flat molded body 11 is pushed up while being supported by the upper surface of the lower punch 12, the molded body 11 is quickly taken out from the lower mold 2 without being damaged. Further, when there is a concern about the occurrence of a laminate crack when the molded body 11 is taken out, there is a method of taking out the molded body 11 with the upper mold 1 and the lower punch 12 sandwiched.

  Also in the molding apparatus having the above configuration, as in the molding apparatus of the first embodiment, the peripheral part of the slide groove 2a of the lower mold 2 (both side parts and the bottom part of the slide groove) and the upper mold 1 A non-magnetic material (weak magnetic material) is arranged on the surface facing the lower mold 2 to eliminate orientation failure due to magnetic field bending and biting of raw material powder due to residual magnetism. Further, since the lower punch 12 constitutes a part of the lower mold 2, it is formed of a ferromagnetic material in order to efficiently apply a magnetic field. When the bottom surface portion is made of a non-magnetic material (weak magnetic material), it is preferable that the portion near the top surface is made of a non-magnetic material (weak magnetic material).

(Third embodiment)
The molding apparatus according to this embodiment is an embodiment provided with a fixing means for fixing the lower punch 12 to the lower mold 2. In the molding process, there is a possibility that distortion due to compression of the lower punch member itself occurs in the length direction of the lower punch 12 (up and down direction in the drawing). If such distortion occurs, the molded body 11 may be cracked. It becomes. Therefore, in the molding apparatus of this embodiment, a mechanical stopper is provided in the vicinity of the upper surface of the lower punch 12 in order to suppress the amount of compressive strain as much as possible, to suppress the distortion of the lower punch 12 during molding pressurization, and the upper surface is a lower metal. The mold 2 is maintained so as to be flush with the molding surface. Thereby, the molded object 11 without a crack can be obtained reliably, and it becomes possible to take out from a metal mold | die.

  9a to 9e show a molding procedure by the molding apparatus of this embodiment. As a specific configuration of the molding apparatus, for example, as shown in FIG. 9A, a lower punch stopper 13 is provided as the fixing means.

  The lower punch stopper 13 is engaged with the lower punch 12 from the left-right direction in the drawing, and fixes the lower punch 12 at a predetermined position (a position where the upper surface is flush with the molding surface of the lower mold 2). A concave portion 14 is formed on the peripheral surface corresponding to the lower punch stopper 13 at a position slightly retracted from the upper surface of the lower punch 12, and by inserting the tip of the lower punch stopper 13 into the concave portion 14, The lower punch 12 is fixed to the lower mold 2.

  The lower punch stopper 13 fixes the lower punch 12 against the pressing force during molding, and the material thereof may be a material having a strength that can withstand this. Specifically, it is preferably formed of a cemented carbide or the like. Moreover, although the shape was also plate-shaped here, it can be made into arbitrary shapes, such as a pin shape. Furthermore, in this embodiment, the lower punch stopper 13 is engaged with the lower punch 12 from both the left and right sides. In addition, for example, the lower punch stopper 13 is engaged with the lower punch 12 from the front and back sides with respect to the paper surface. Alternatively, the lower punch 12 may be locked and fixed from four directions.

  Hereinafter, the molding process by the molding apparatus of this embodiment will be described. As in the previous embodiments, first, as shown in FIG. 9a, the upper mold 1 is raised, the raw material powder 10 is accommodated, and the bottom surface is By reciprocating the opened feeder box 9, the raw material powder 10 is filled in a space surrounded by the lower die 2 and the left and right punches 3, 4 so as to be in a so-called slit state. At this time, the tip of the lower punch stopper 13 is inserted into the concave portion 14 of the lower punch 12, and the lower punch 12 is fixed. In addition, the demagnetization of the upper mold 1 prior to the filling of the raw material powder 10 is the same as in the previous embodiments.

  Next, as shown in FIG. 9 b, the upper mold 1 is lowered until the lower surface of the upper mold 1 hits the upper surface of the lower mold 2, and the upper mold 1, the lower mold 2, and the left and right punches 3, 4 A closed space is formed. Subsequently, as shown in FIG. 9c, a magnetic field is applied to the raw material powder 10 in the vertical direction by the upper coil 5 and the lower coil 6 in this state (a state in which the raw material powder 10 is accommodated in the closed space). While applying a magnetic field, the left punch 3 is moved in the right direction in the figure and the right punch 4 is moved in the left direction in the figure, and the filled raw material powder 10 is pressed from the left and right to be compressed. Thereby, the molded object 11 of a predetermined shape is formed. Further, in order to promote the magnetic field orientation of the raw material powder 10, the left punch 3 and the right punch 4 are operated in the direction opposite to the pressurizing direction before the magnetic field is applied, and the left space 3 and the right punch are increased after increasing the closed space volume. 4 may be used for pressurization. The bulk density at that time is preferably 20 to 30% of the theoretical density. The magnetic field application direction is a direction orthogonal to the pressurizing direction by the left and right punches 3 and 4, and therefore, orthogonal magnetic field shaping is performed.

  The lower punch 12 is fixed by the lower punch stopper 13 until the molding is completed. After the molding is completed, the lower punch stopper 13 moves backward in the direction of the arrow x as shown in FIG. 12 is released and the fixed state is released. In this state, the lower die 2 and the left and right punches 3 and 4 are lowered in the direction of the arrow z while maintaining the state sandwiched between the upper die 1 (relatively the lower punch 12 is raised), and finally FIG. 9e. As shown, the upper die 1 is raised and the molded body 11 on the lower punch 12 is taken out.

  In the molding apparatus of this embodiment, since the lower punch stopper 13 which is a fixing means for the lower punch 12 is added, the occurrence of distortion in the lower punch 12 can be eliminated, and the occurrence of cracks resulting from this distortion is generated. Can be prevented.

  Also in the molding apparatus having the above configuration, as in the molding apparatus of the first embodiment or the second embodiment, the peripheral portion of the slide groove 2a of the lower mold 2 (both side portions and the bottom surface portion of the slide groove), A nonmagnetic material (weak magnetic material) is disposed on the surface of the upper mold 1 facing the lower mold 2. Thereby, the orientation failure due to the magnetic field bending can be eliminated, and further, the biting of the raw material powder due to the residual magnetism can be eliminated.

(Fourth embodiment)
As shown in FIG. 10, the molding apparatus of the present embodiment has a mold 21 in which a molding space 21a penetrating in the horizontal direction is formed as a mold structure, and is movable in the horizontal direction in the molding space 21a. The left punch 22 and the right punch 23 are combined.

  Here, the mold 21 is a mold called a mortar mold, and as described above, the molding space 21a is formed through the horizontal direction. Therefore, this corresponds to a state in which the mortar die used in the normal orthogonal magnetic field forming method is placed horizontally. In FIG. 10, for convenience, the mold 21 is divided into upper and lower parts, but in actuality, it is formed as an integral mold as shown in FIG.

  In the mold 21, for example, when a flat plate-shaped molded body is molded, the bottom surface 21 b and the top surface of the molding space 21 a are chamfered on the main surface. Accordingly, in the mold 21, the large bottom surface 21b and the top surface are horizontal.

  On the other hand, the molding space 21a also has a function of guiding the movement (sliding) of the left punch 22 and the right punch 23. The width and height of the molding space 21a are the left punch 22 and the right punch 23, respectively. The width and thickness of the molded body to be molded are determined by this.

  The left punch 22 and the right punch 23 correspond to pressurizing means, move in the horizontal direction in the molding space 21a, and press-mold the rare earth magnet raw material powder filled in the molding space 21a. Therefore, the pressing force is applied in the horizontal direction during molding. In addition, although you may pressurize with one punch, it is more preferable to pressurize with both punches since a uniform pressure is applied to raw material powder.

  At the time of molding, the planar shape of the molded body is determined by the shape of the tip of the left punch 22 or the right punch 23. In the case of the tip shape of the left punch 22 and the right punch 23 shown in FIG. It will be molded into a molded body. For example, when forming a disk-shaped molded body having a circular planar shape, the shapes of the front end surfaces of the left punch 22 and the right punch 23 may be arcuate.

  Although not shown in FIG. 10, the molding apparatus of this embodiment is provided with a magnetic field generating coil that applies a magnetic field in the vertical direction, and a magnetic field is applied to the molded body in the vertical direction during molding. Is done. At the time of molding, a pressing force is applied in the horizontal direction by the left punch 22 and the right punch 23, so that the molding is performed by an orthogonal magnetic field molding method in which the magnetic field application direction and the compacting direction are orthogonal to each other.

  In the above mold structure, the raw material powder cannot be filled into the molding space 21a of the mold 21 from above. The mold 21 is formed as a single body, and for example, the upper half cannot be separated and moved. Therefore, in the molding apparatus of this embodiment, a filling table 24 is installed adjacent to the mold 21 and the raw material powder is filled thereon.

  Here, the filling table 24 is formed with a guide groove 24a that guides the movement (sliding) of the left punch 22 and the right punch 23 corresponding to the molding space 21a of the mold 21. The left punch 22 and the right punch 23 are configured to slide. The bottom surface 24 b of the guide groove 24 a of the filling table 24 is flush with the bottom surface 21 b of the molding space 21 a of the mold 21. Therefore, the left and right punches 22 and 23 can slide continuously from the molding space 21 a of the mold 21 to the guide groove 24 a of the filling table 24.

  When filling the raw material powder, both the left punch 22 and the right punch 23 are moved to the guide groove 24a of the filling table 24 as shown in FIG. At this time, a space constituted by the tip of the left punch 22, the tip of the right punch 23, and the guide groove 24a becomes a space filled with the raw material powder, and the raw material powder is filled therein using, for example, a feeder box. Therefore, at the time of filling, the filling amount of the raw material powder is adjusted by adjusting the distance between the tip of the left punch 22 and the tip of the right punch 23. At the time of filling, the area of the opening portion of the space formed by the tip of the left punch 22, the tip of the right punch 23, and the guide groove 24a can be made wide corresponding to the main surface of the molded body, and filling is easy. Can be done.

  After the filling of the raw material powder on the filling table 24, it moves in the horizontal direction while maintaining the relative positional relationship between the left and right punches 22 and 23, and moves into the molding space 21a of the mold 21. Thereby, the filled raw material powder is also introduced into the molding space 21 a of the mold 21. That is, the left and right punches 22 and 23 function as a raw material powder introduction mechanism for introducing the raw material powder into the mold. Then, the left and right punches 22 and 23 are pressed in the direction in which the left and right punches 22 are abutted with each other, whereby the filled raw material powder is pressure-molded. As shown in FIG. 12, as shown in FIG. Is formed.

  After the molding, the left punch 22 and the right punch 23 are slid in the molding space 21a, and the molded body 25 is sandwiched between the punches 22 and 23, and is opposite to the direction in which the filling table 24 is installed. For example, as shown in FIG. 13, the molded body 25 is taken out from the molding space 21a. Therefore, the left and right punches 22 and 23 also function as a molded body take-out mechanism.

  At this time, for example, the punch 21 is provided in a state where a support table that forms the same plane as the bottom surface 21b of the molding space 21a of the mold 21 is provided adjacent to the mold 21 and the bottom surface of the molded body 25 is supported on the upper surface of the support table. If it moves horizontally by 22 and 23, a local force will not be added to the molded object 25 at the time of taking-out, and the careless damage of the molded object 25 can be prevented. Needless to say, the support table is installed adjacent to the side of the mold 21 opposite to the side on which the filling table 24 is installed.

  When the molded body 25 is taken out, a crack called a laminate crack may occur in the molded body due to the sudden release of pressure. Therefore, in order to avoid this, the molded body 25 is taken out in the horizontal direction while being sandwiched between the two punches 22 and 23 as described above. Apply pressure. As a result, the sudden release of the pressure is alleviated and the generation of cracks is suppressed. In order to apply a predetermined pressing force to the molded body 25 by the two punches 22 and 23 during the horizontal movement as described above, for example, dampers and cushions are provided on the punches 22 and 23, and elasticity of these dampers and cushions is provided. It is convenient to apply the pressing force by force. Here, the predetermined pressing force may be a constant pressure, but it is preferable that the predetermined pressing force is gradually reduced according to the amount of the molded body extracted.

Alternatively, a punch taper may be provided in the mold 21 to suppress the laminate crack. In the case of the mold 21 having the above-described structure, as shown in FIG. 14 with the mold 21 partially broken, the molding space 21a may be tapered in the width direction. In this case, if the direction in which the molded body 25 is taken out is an arrow direction, the drawing taper is formed so that the width of the molding space 21a gradually increases in the direction in which the molded body 25 is taken out. Specifically, in the molding space 21a, so that the width W ₂ of the take-out side end portion than the width W ₁ of the push-end by right punch 23 becomes large. Further, the draft taper can be applied not only in the width direction of the molding space 21a but also in the height direction.

  In FIG. 14, the taper is exaggerated and drawn, but in reality, it is not a visible taper, and a taper with a very slight dimensional difference may be added. Specific numerical values are, for example, about 0.02 mm to 0.5 mm per 100 mm slide length of the molding space 21a. The design of the taper is not limited to this, and may be set as appropriate according to the dimensions of the closed space of the mold, the material to be molded, and the like.

  The above is the configuration of the molding apparatus of the present embodiment. Next, a molding method using this molding apparatus will be described. 15a to 15e show a procedure for forming rare earth magnet raw material powder using the forming apparatus shown in FIG. 15A to 15E show an upper coil 26 and a lower coil 27 that apply a magnetic field at the time of molding, and a magnetic field is applied in the vertical direction (vertical direction in the figure) by these coils 26 and 27. A support table 28 is provided adjacent to the mold 21, and the upper surface of the support table 28 is flush with the bottom surface 21 b of the molding space 21 a of the mold 21.

  When forming the rare earth magnet raw material powder, first, as shown in FIG. 15A, the left and right punches 22 and 23 are moved onto the filling table 24, and the feeder box 29 in which the raw material powder 30 is accommodated and the bottom surface is opened. As shown in FIG. 15b, the raw material powder 30 is filled into a space surrounded by the guide grooves 24a of the filling table 24 and the tips of the left and right punches 22 and 23 so as to be in a so-called ground state. At this time, the mold 21 and the upper coil 26 do not interfere with filling, and the opening area of the space surrounded by the guide groove 24a of the filling table 24 and the tips of the left and right punches 22 and 23 is flat. Larger corresponding to the main surface of the molded body, for example, it can be much wider than the opening when a flat plate-shaped molded body is arranged in the vertical direction, and also shallow in the depth direction The raw material powder 30 can be easily filled.

  Next, as shown in FIG. 15 c, the left and right punches 22 and 23 are slid into the molding space 21 a of the mold 21 while maintaining the relative positional relationship. The raw material powder 30 filled in the above process is introduced into the molding space 21 a of the mold 21 as the left and right punches 22 and 23 move horizontally.

  Subsequently, as shown in FIG. 15 d, in this state (a state in which the raw material powder 30 is introduced into the molding space 21 a of the mold 21), the upper coil 26 and the lower coil 27 make a vertical direction with respect to the raw material powder 30. Apply a magnetic field. While applying the magnetic field, the left punch 22 is moved in the right direction in the figure and the right punch 23 is moved in the left direction in the figure, and the filled raw material powder 30 is pressed from the left and right to be compressed. Thereby, the molded body 25 having a predetermined shape is formed. Further, in order to promote the magnetic field orientation of the raw material powder 30, the left punch 22 and the right punch 23 are operated in the direction opposite to the pressurizing direction before the magnetic field is applied, and the left punch 22 and the right punch are increased after increasing the closed space volume. The pressurization may be performed by 23. The bulk density at that time is preferably 20 to 30% of the theoretical density. The magnetic field application direction is a direction orthogonal to the pressurizing direction by the left and right punches 22 and 23, and therefore, orthogonal magnetic field shaping is performed.

  In the compaction, the pressure applied by the left and right punches 22 and 23 may be appropriately set according to the type, size, shape, etc. of the raw material powder 30 to be used, but is usually about 30 MPa to 200 MPa. Similarly, the strength of the magnetic field to be applied may be appropriately set according to the raw material powder 30 to be used, and may be set to about 0.8T to 2.0T, for example.

  After forming the molded body 25, as shown in FIG. 15e, the molded body 25 is horizontally moved leftward in the figure while being sandwiched between the left punch 22 and the right punch 23 and taken out from the molding space 21a of the mold 21. At this time, the molded body 25 is horizontally moved while being in contact with the upper surface of the support table 28 (supported state), and there is a situation in which an unexpected force is applied when the molded body 25 is taken out and the molded body 25 is damaged. Avoided. In addition, when the molded body 25 is moved horizontally, by applying a certain amount of pressure to the molded body 25 by the left and right punches 22 and 23, or by adding a taper to the molding space 21a of the mold 21, Occurrence of laminate cracks during removal can also be suppressed.

  As mentioned above, according to the shaping | molding apparatus of this embodiment, a series of processes from filling of the raw material powder 30 to shaping | molding and taking-out can be efficiently performed only by the horizontal movement of the left-right punches 22 and 23. Filling with the raw material powder 30 is easy, and simplification of the apparatus configuration and high precision of the mold 21 can be realized. Further, the molded body 25 can be efficiently removed from the mold without cracks, and continuous molding is possible. Furthermore, since the molded body 25 to be molded is molded by orthogonal magnetic field molding, the degree of orientation is high, and a magnet obtained by sintering this has excellent magnetic properties. Therefore, according to the present embodiment, it is possible to mass-produce high-precision and high-performance rare earth sintered magnets with a simple apparatus configuration in combination with these effects.

  Even in the molding apparatus having the above-described configuration, if the mold 21 is formed of a ferromagnetic material, it is possible to efficiently apply a magnetic field and realize high orientation. However, if the entire mold 21 is made of a ferromagnetic material, the above-described problem of magnetic field bending occurs. Therefore, also in the molding apparatus of this embodiment, as shown in FIG. 16, if the portion 21 c corresponding to the side wall of the molding space 21 a of the mold 21 is a nonmagnetic material (weak magnetic material), poor alignment due to magnetic field bending. Can be eliminated. In this case, at least the tip portions of the left and right punches 22 and 23 are also formed of a non-magnetic material (weak magnetic material), so that it is possible to prevent magnetic field bending around the entire periphery of the molded body.

  In the case of the molding apparatus according to the present embodiment, the mold 21 is integrated and is not divided into upper limits, for example, so that the problem of biting of the raw material powder does not occur due to residual magnetism. Therefore, the surfaces in contact with the upper and lower sides of the molding space 21a can be left as a ferromagnetic material, so that a magnetic field can be applied without interposing an extra magnetic gap. As a result, it is possible to achieve even higher orientation in the molded body to be molded.

It is a perspective view which shows schematic structure of the shaping | molding apparatus of 1st Embodiment. It is a schematic diagram which shows the shaping | molding state in the shaping | molding apparatus of 1st Embodiment. (A) is a schematic diagram explaining the flow of the magnetic flux when the magnetic field bending has occurred, and (b) is a schematic diagram illustrating the flow of the magnetic flux when the magnetic field bending has not occurred. It is a schematic perspective view which shows an example of arrangement | positioning of the nonmagnetic material (weak magnetic material) in a lower metal mold | die. It is a figure which shows an example of the hysteresis curve of a molded object and a metal mold | die. It is a schematic perspective view which shows the example which has arrange | positioned the nonmagnetic material (weak magnetic material) to the opposing surface of an upper mold and a lower mold, respectively. It is a figure which shows the shaping | molding process by the shaping | molding apparatus of 1st Embodiment, and is a figure which shows a raw material powder filling process. It is a figure which shows a closed space formation process. It is a figure which shows the compacting process in a magnetic field by a left-right punch. It is a figure which shows a molded object taking-out process. It is a figure which shows the shaping | molding process by the shaping | molding apparatus of 2nd Embodiment, and is a figure which shows a raw material powder filling process. It is a figure which shows a closed space formation process. It is a figure which shows the compacting process in a magnetic field by a left-right punch. It is a figure which shows a molded object taking-out process. It is a figure which shows the shaping | molding process by the shaping | molding apparatus of 3rd Embodiment, and is a figure which shows a raw material powder filling process. It is a figure which shows a closed space formation process. It is a figure which shows the compacting process in a magnetic field by a left-right punch. It is a figure which shows a lower punch stopper cancellation | release and a lower metal mold | die lowering process. It is a figure which shows a molded object taking-out process. It is a perspective view which shows schematic structure of the shaping | molding apparatus of 4th Embodiment. It is a perspective view which shows the state of the left-right punch at the time of raw material powder filling. It is a perspective view which shows a partially broken state. It is a perspective view which shows the taking-out state of a molded object. It is a perspective view which shows the example of the shape of the shaping | molding space to which the punch taper was added, and fractures | ruptures and shows a metal mold | die partially. It is a figure which shows the shaping | molding process by the shaping | molding apparatus of 4th Embodiment, and is a figure which shows a raw material powder filling process. It is a figure which shows a raw material powder filling state. It is a figure which shows the introduction state to the shaping | molding space of raw material powder. It is a figure which shows the compacting process in a magnetic field by a left-right punch. It is a figure which shows a molded object taking-out process. It is a schematic perspective view which shows an example of arrangement | positioning of the nonmagnetic material (weak magnetic material) in the metal mold | die of the shaping | molding apparatus of 4th Embodiment.

Explanation of symbols

1 Upper mold, 2 Lower mold, 2a Slide groove, 3 Left punch, 4 Right punch, 5 Upper coil, 6 Lower coil, 8 Support table, 9 Feeder box, 10 Raw material powder, 11 Molded body, 12 Lower punch, 13 Lower punch stopper, 21 Mold, 21a Molding space, 22 Left punch, 23 Right punch, 24 Filling table, 25 Molded body, 26 Upper coil, 27 Lower coil, 28 Support table, 29 Feeder box, 30 Raw material powder

Claims (9)

Molds made of a ferromagnetic material are arranged above and below the molding space, and one or more punches that move in a substantially horizontal direction with respect to the mold and pressurize the rare earth magnet raw material powder in a substantially horizontal direction, and a molding space Magnetic field applying means for applying a magnetic field in a substantially vertical direction to the rare earth magnet raw material powder through the mold,
The mold made of the ferromagnetic material is divided into two vertically, and the punch is inserted into the lower mold, and a groove part forming the molding space is formed,
The molding apparatus characterized in that both side portions of the groove portion of the lower mold and at least a tip portion of the punch are made of a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less . The molding apparatus according to claim 1, wherein a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less is disposed in a portion contacting the upper and lower sides of the molding space. 2. The molding apparatus according to claim 1 , wherein a surface of the upper mold facing the lower mold is made of a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less. The molding apparatus according to any one of claims 1 to 3 , wherein a bottom surface portion of the groove portion of the lower mold is made of a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less. . 5. The molding apparatus according to claim 1 , wherein the punch functions as a molded body take-out mechanism that takes out a molded body that is molded in a substantially horizontal direction. The molding apparatus according to any one of claims 1 to 4, wherein the lower mold includes a lower punch that is movable relative to the lower mold in a vertical direction. The molding apparatus according to claim 6 , further comprising a fixing unit that fixes the lower punch during molding. Molds made of a ferromagnetic material are arranged above and below the molding space, and one or more punches that move in a substantially horizontal direction with respect to the mold and pressurize the rare earth magnet raw material powder in a substantially horizontal direction, and a molding space Magnetic field applying means for applying a magnetic field in a substantially vertical direction to the rare earth magnet raw material powder through the mold,
The mold is formed integrally with the upper and lower sides, and has a molding space in which the punch is inserted in a horizontal direction,
A molding apparatus, wherein a side wall portion of the molding space of the mold and at least a tip portion of the punch are made of a nonmagnetic material or a weak magnetic material having a saturation magnetic flux density of 0.8 T or less . The molding apparatus according to any one of claims 1 to 8, wherein the non-magnetic material or the weak magnetic material having a saturation magnetic flux density of 0.8 T or less is formed of a cemented carbide.

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