JPS63204709A - Molding device for ring-shaped anisotropic magnet - Google Patents

Abstract

PURPOSE:To make it possible to work by keeping a permanent magnet body away when the final molded body is picked out by a method wherein the rings, to be arranged inside and outside of final molded body formed with magnetic powder, are made of soft magnetic material, and one of the upper and the lower permanent magnet bodies located on a magnetic field generating source is provided in such a manner that it can be freely moved forward or backward against the inner surface of a core member. CONSTITUTION:A core metal 6 is formed into cylindrical shape, a pair of upper and lower permanent magnets 2 and 2 are provided in such a manner that they are freely moved forward and backward relatively, and the rings 3 and 4 consisting of soft magnetic material are arranged on the position corresponding to the final position of the molded body on a metal mold 8 and the core metal 6. Accordingly, the upper and the lower permanent magnets 2 and 2 can be kept away from the rings 3 and 4. As a result, magnetic powder 1 can be put in the inside of a cavity in the state wherein there is almost no magnetism. The final molded body can be picked out in the state wherein there is no magnetism around the cavity when it is picked out after molding.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for molding a ring-shaped anisotropic magnet using powder of ferrite, rare earth 1T11 stone, etc., or a slurry of the powder as a raw material.

(Prior art) As a molding device for this type of magnet, Japanese Patent Application Laid-Open No. 55-1656
The one described in No. 07 is publicly known.

FIG. 6 shows the conventional molding apparatus. In FIG. A cylindrical core metal C141 made of magnetic material is fitted into the coaxial core, magnetic powder aO is inserted between the mold ring and the core metal C141, and a pair of cylindrical punches made of non-magnetic material are formed. The ring-shaped magnetic field upper and lower coils α are separately wound on the upper and lower sides of the outside of this mold 03.
A pair of upper and lower spacers are arranged with the same poles facing each other, and cylindrical upper and lower spacers made of non-magnetic material are arranged inside the upper and lower coils, respectively. , serves as a guide for the lower bunch α9.0!9. A casing Ql made of a magnetic material is arranged between the upper and lower coils ae5αη, on the outside, and on the upper and lower sides.

When current is passed through the upper and lower coils Ql and αη, a magnetic field is formed in the direction of the arrow. Ring-shaped upper and lower coils 0119, a
Since the same poles are placed opposite each other, the lines of magnetic force head inward from the top and bottom of the casing 0I, pass through the top and bottom bunches 0 and 0, reach the core metal a of the shaft, and here The upper and lower magnetic lines of force face each other and merge, proceed radially outward, pass through the magnetic powder OD, pass through the mold 03, and head toward the casing θ.

As described above, since the magnetic field is applied radially outward from the shaft portion of the cylindrical magnet, a ring-shaped magnet having anisotropy in this direction can be obtained.

(Problems to be Solved by the Invention) The problems to be solved by the present invention will be explained with reference to FIG.

The lines of magnetic force pass inward from the top and bottom of the casing 0I through the upper and lower punches α9 and α, but these punches α and
Since (2) is a non-magnetic material, the strength of the magnetic field is slightly weakened in this part, so the strength of the magnetic field applied to the magnetic powder αυ is also weakened accordingly.

Furthermore, a coil and its power source are required to generate a magnetic field.
This increases equipment costs. In addition, in order to form a radial magnetic field outward from the shaft part in the magnetic powder α0, the mounting positions of the upper and lower coils αe and α must be placed outside of the magnetic powder αυ, and In order to generate the magnetic field necessary to manufacture a magnet, the α force of the coil requires multiple layers of filaments, and its shape and dimensions are quite large. The upper and lower punches of non-magnetic material are placed in the magnetic field line passage from the to the mold side.
Since there is an α difference, if the magnetic field weakened by this part is to be compensated for, the upper and lower coils +11 and αη will have to be even larger. As a result, the casing Ql surrounding the upper and lower coils 019 and αη to form a magnetic field also becomes large, and the entire device becomes large. Also, the upper and lower coils Ql,
Since an electric power source for αη is installed, space is required, and the installation floor becomes wide, equipment costs increase, and power consumption for the upper and lower coils QISQη is also required.

The present invention solves the above-mentioned problems of the conventional ones, and enables the series of molding processes from putting magnetic powder into the mold to taking out the molded body after molding to be performed reliably and easily. It is an object of the present invention to provide a compact molding device for a ring-shaped anisotropic magnet that can apply a high IT field to magnetic powder housed in a mold and increase the degree of orientation of the magnetic powder.

(Means for Solving the Problems) In order to achieve this object, the present invention has the following configuration. That is, the ring-shaped anisotropic magnet molding device according to the present invention includes a cylindrical mold (8) made of a non-magnetic material, and a cylindrical core made of a non-magnetic material that is loosely fitted into the mold (8). Gold (6)
and upper and lower annular punches (7) and (27) made of non-magnetic material that advance and retreat into an annular space defined between the mold (8) and the core metal (6). Mold (8) and core metal (6
) is supported concentrically, the upper and lower annular punches (7) and (27) relatively enter the magnetic powder (11) housed in the annular space to apply pressure. A molding device for molding a ring-shaped anisotropic magnet, the mold (8)
a ring-shaped recess formed at the final position of the molded body and opening outward; a ring (4) made of a soft magnetic material fitted into the recess; and the mold (8) in the core metal (6). ) a ring-shaped recess that opens inward and is formed at a position corresponding to the recess of the ring, a ring (3) made of a soft magnetic material fitted into the recess, and a ring (3) made of a soft magnetic material that is fitted into the inner surface of the core metal (6), respectively. a pair of upper and lower permanent magnet bodies (2), which are arranged so that they can be combined with each other, and are arranged with the same poles facing each other, and at least one of which is provided so as to be movable relative to the inner surface of the core bar (6); (2).

(Function) The ring-shaped anisotropic magnet forming apparatus according to the present invention has a mold (
8) and a cylindrical core metal (6) that loosely fits concentrically into the cough mold (8).
), upper and lower annular punches (7) and (27) are provided so as to be relatively intrusible into the annular space (cavity) defined by Pressure forming is performed using upper and lower annular punches (7) and (27). (
2) A ring (4) made of a soft magnetic material is provided so that the rings (2) and (2) can move forward and backward relative to each other, and is located at a position corresponding to the final position of the molded body in the mold (8) and core metal (6). and (3), the series of steps from putting the magnetic powder (1) into the cavity to taking out the compact after molding can be carried out reliably and easily.

In other words, when putting the magnetic powder (1) into the cavity,
The upper and lower permanent magnet bodies (2), (2) are attached to the ring (4).
, (3), the magnetic powder [11] can be placed in a state where there is almost no magnetism on the inner surface of the cavity. Magnetic powder (1
) will not adhere over a wide range in the upper and lower directions on the inner surface of the cavity. Therefore, when the upper and lower annular punches (7) and (27) enter, the upper and lower annular punches (7) and (27) The magnetic powder (1) attached to the outer periphery of the punches (7), (27) and the inner surface of the cavity is
There is no rubbing, and the upper and lower annular punches (7) and (27) can smoothly advance to the pressurization start position.

Furthermore, when taking out the molded body after molding, the upper and lower permanent magnets (2), (2) are moved away from the rings (4), (3) beforehand. It is possible to take out the final molded product in a state where there are almost no It is possible to prevent accidents that often occur when the final molded product is taken out by sliding it on the inner surface of the cavity in the adsorbed state. In addition, magnetic powder +
1) and when taking out the final molded body, both the upper and lower permanent magnet bodies (2), (2) are attached to the rings (4), (
3), but one of the upper and lower permanent magnets (2), (2) is fitted in advance to the inner surface of the cylindrical core metal (6), and only the other is kept away from the magnetic powder. (Even if you move it away when putting in 11 and taking out the final molded product, there is virtually no earthen floor surface.

Furthermore, in the present invention, the rings (4) and (3) made of soft magnetic material are used as the rings arranged in the recesses of the mold (8) and the core metal (6), respectively, so that the above series The process will certainly become easier.

In other words, hard magnetic materials have a characteristic that the residual magnetic flux is large even when the magnetic field is removed, whereas soft magnetic materials easily become magnetized when a magnetic field is applied, and when the magnetic field is removed, the residual magnetic flux is extremely small. This, together with the fact that the upper and lower permanent magnet bodies (2), (2) are configured to move forward and backward, allows the upper and lower permanent magnet bodies (2),
If the magnetic field is removed by moving the ring 2 away from the rings (4) and (3), there will be almost no magnetism in the cavity components (therefore, the series of steps from putting in the magnetic powder +11 to taking out the final molded body) It is actually easier than this.

In addition to the upper and lower annular punches (7) and (27),
The upper and lower permanent magnet bodies (2), (2) are also molded (8), core metal (
6) so that it can move forward and backward relative to the
It becomes possible to form the magnetic powder (1) with a high degree of orientation. That is, before the upper and lower annular punches (7) and (27) start pressurizing the magnetic powder +11 housed in the cavity, the upper and lower permanent magnet bodies (2), ( 2) can be advanced to a predetermined position, and therefore the upper and lower permanent magnet bodies (2), (2) can be moved relatively freely before the magnetic powder (11 is pressurized).
The upper and lower annular punches (7) and (27) and the upper and lower permanent magnet bodies (2) ,
(2) means that the upper and lower permanent magnets (2), (2) enter the inner surface of the core bar (6) before the upper and lower annular punches (7), (27). Although it is preferable from the viewpoint of accuracy, even if both enter at the same time, the upper and lower annular punches (7) and (2)
7) enters the cavity and before the pressurization starts, the upper and lower permanent magnets (2) and (2) simultaneously enter the core bar (6) and move to the predetermined position. During this time, the degree of orientation is also improved and there is virtually no problem.

Furthermore, in the present invention, the upper and lower permanent magnet bodies (2), (2) of the magnetic field generation source provided movably forward and backward with respect to the core metal (6) are arranged with the same poles facing each other. When the core bar (6) is entered, the magnetic lines of force coming out from the upper and lower permanent magnet bodies (2), (2) face each other, merge, and proceed radially outward.
It passes through the ring (3) made of soft magnetic material, passes through the magnetic powder +11, and passes through the ring (4) made of soft magnetic material. A sex magnet will be obtained.

Moreover, the ring (3) is fitted into a ring-shaped recess that opens toward the inside of the core metal (6), and the ring (4)
is fitted into the ring-shaped recess opening toward the outside of the mold (8), so this magnetic field line passage is formed by the magnetic powder (1).
The strength of the magnetic field does not decrease because all parts except the part in contact with the ring (3) are made of soft magnetic material, and the magnetic field strength does not decrease.
, (4), it is possible to intensively apply a high magnetic field to the magnetic powder (1) located between the rings (3) and (4). And magnetic powder +1
In order to prevent rings (3) and (4) from being worn out when 1 is pressurized, the material of the core bar (6) is left between the ring (3) and the magnetic powder (1), and the magnetic powder is (1) and ring (4)
Rings (3) and (4), leaving the mold (8) material between them.
) is protected.

In the present invention, since the magnetic field generation source is the upper and lower pair of permanent magnets (2), (2), a ring-shaped coil and its power source are not required. Therefore, there is no need for an outer magnetic member that surrounds the coil and forms a magnetic field, making the entire molding device simpler and more compact.In addition, since there is no need for a power supply for the coil, the floor space is also smaller. It is also economical as it does not require any power consumption.

(Example) A construction example for explaining an example of the present invention with reference to the drawings.
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In the ring-shaped anisotropic magnet forming apparatus of the first embodiment, as shown in FIG.
A mold made of a cylindrical non-magnetic material (such as tungsten carbide, etc.) with the same height as the mold (8), with gaps at the same intervals all around the mold (8). ) The core bar (6) is loosely fitted concentrically,
Magnetic powder placed between the mold (8) and the core metal (6) +1
1 is provided with upper and lower punches (7) and (27) made of a cylindrical non-magnetic material (for example, tungsten carbide, etc.).

A cylindrical recess that opens outward is provided at the position of the final molded body of magnetic powder +11 in the mold (8), and a cylindrical recess made of soft magnetic material (for example, pure iron) is provided in the outer envelope. A ring (4) of the metal mold (4) is fitted therein, and a soft magnetic material (for example, pure iron, etc.) that opens inward is fitted in the core metal (6) at a position corresponding to the recess of the mold (8). A cylindrical ring (3) is fitted. That is, the magnetic powder +11 fills the annular space (cavity) between the mold (8) and the core metal (6).
The mold (8) and core metal (
Rings (4) and (3) having substantially the same height as the final molded product are provided in the area surrounding the final position of the pressure molding in step 6), where the final molded product is located. Therefore, when looking at the cross section at the positions of rings (4) and (3), the magnetic powder of the mold (8) and core bar (6) +1
Except for the part that contacts 1, the rest is all made of soft magnetic material.

(2), (2) are a pair of upper and lower permanent magnets (for example, samarium cobalt magnets, which are a type of rare earth magnet), and are provided with the same poles facing each other, and the permanent magnets (2)
, (2) are respectively attached to the cylinders (41), (41) and configured to be movable up and down, and configured to be able to move forward and backward into the inner surface of the cylindrical core metal (6). Rare earth magnets have large coercive force and large residual magnetism, and are preferred permanent magnets for carrying out the present invention.

The mold (8) is formed by a base frame (51) and an upper platen (52) that is movable up and down, and a core metal (6) that is loosely fitted concentrically into the mold (8). , are held between the base frame (51) and an upper platen (53) that is movable upwardly and downwardly. Furthermore, the lower punch (27) is connected to the cylinder (44), and the upper punch (7) is connected to the cylinder (43), respectively. It is configured to move forward and backward.

As shown in No. 1 I'i21, the core metal (6) is loosely fitted concentrically into the mold (8) whose axis is vertical, and the base frame (51) is
) above the upper platen (52), (5
3) and identify the mold f8) and the core metal (6). 9. Next, insert the lower punch (27) from below between the mold (8) and the core metal (6) using the cylinder (44). Then, its upper end is a cylindrical ring (
Set the lower punch (27) so that it is located at the height of the lower end (81) of 4) and (3) and keep that position until the end of the pressurizing process. By supporting the lower punch (27) from the start of pressure molding of the magnetic powder (1) to the completion of compression molding, the work of pressing the magnetic powder (1) can be done by operating only the upper punch (7). Pressure work becomes easier.

Next, a predetermined amount of magnetic powder +11 is placed in the cavity between the mold (8) and the core metal (6), that is, the magnetic powder after final pressurization (
The height of the cylindrical shape of the final molded body in 1) is the same as that of the cylindrical ring (4
), add an amount of magnetic powder (1) that will be the same as the height of (3). When putting the magnetic powder (l) into the cavity, insert the upper and lower permanent magnets (2) into the ring (4), 1
3), so there is almost no magnetism inside the cavity, so the magnetic powder (1) can be easily put into the cavity, and when the upper punch (7) is inserted, it can be smoothly placed at the pressure start position. It can be advanced up to.

Next, place the pair of upper and lower permanent magnets (2), (2) with the same poles facing each other into the core metal (6) into the cylinders (41), (2), respectively.
41), insert the upper permanent magnet body (2) from above and the lower permanent magnet body (2) from below. Then, move the upper and lower permanent magnets (2), (2) toward the position where the degree of orientation of the magnetic powder (1) peaks at the same speed (for example, 5 tm /
sec, ), and after a few seconds (for example, 1 second), insert the upper punch (7) between the mold (8) and the core metal (6) from above using the cylinder (43). , and lowered at the same speed as the upper permanent magnet (2) so as not to precede the upper permanent magnet (2). In order to increase the degree of orientation of the magnetic powder +11, upper and lower permanent magnet bodies (2
), (2) reach the predetermined position where the degree of orientation of the magnetic powder +11 peaks. - The upper and lower permanent magnet bodies ( 2
), (2) and the upper punch (7) are set first.

In this way, the same poles are placed opposite each other and close to each other,
The magnetic lines of force emitted from the lower permanent magnets (2) and (2) merge in opposite directions, pass through the ring (3), pass through the magnetic powder (1), and head toward the ring (4), so the direction of the magnetic field is axial. radially outward from the center. The positions of the upper and lower permanent magnet bodies (2), (2) when the degree of orientation of the magnetic powder (11) reaches its peak are determined in advance by the height and position of the final compact of the magnetic powder (11). , thereby the upper and lower permanent magnet bodies (2), (2) soil, and the lower cylinder (41), (4
The stroke of 1) can also be determined.

When the magnetic powder +11 is not pressurized, the individual magnetic powders can move relatively freely and are easily oriented in accordance with the direction of the magnetic field lines.

Therefore, as the upper and lower permanent magnet bodies (2), (2) approach each other, the degree of orientation of the magnetic powder +11 gradually increases accordingly. Eventually the upper and lower permanent magnet bodies (2), (2)
When reaches the position where the degree of orientation of the magnetic powder (11) reaches its peak, the lower end of the upper punch (7) reaches the upper surface of the magnetic powder fi+.At this time, the degree of orientation of the magnetic powder +11 has reached its peak. , At this position, the upper and lower permanent magnet bodies (2), (2
) is stopped, and the upper punch (7) continues to descend until its lower end reaches the height of the upper ends (82) of the rings (3) and (4), pressing the magnetic powder +11 to complete the molding.

FIG. 2 shows the state of the magnetic powder (1) at the end of pressure molding. The stroke of the cylinder (43) for the upper punch (7) at this time is predetermined based on the height and position of the final compact of the magnetic powder +11. Until this point, press the lower punch (
The upper end of 27) is at the position set before the magnetic powder fl) is pressurized, that is, the lower end of rings (3), (4)
81) maintain the height position.

Next, after moving the upper permanent magnet body (2) above the upper end of the core bar (6) and moving the lower permanent magnet body (2) below the lower end of the core bar (6), the magnetic powder ( In order to prevent the final molded product from 1) from being damaged, while the final molded product is being held between the upper punch (7) and the lower punch (27), the upper punch (7), the final molded product, and the lower punch (27) are simultaneously moved at the same speed. As the WJI moves upward, the upper end of the lower punch (27) reaches the height of the upper ends of the core bar (6) and the mold (8), and the magnetic powder (1
) take out the final molded body. In this way, when taking out the final molded product, by moving the upper and lower permanent magnets (2), (2) away from the rings (3), (4), the soft Ring of magnetic material (3)
, (4) almost disappears, and there is almost no magnetism around the final molded product, so the final molded product can be easily taken out without being damaged.

A ring-shaped recess that opens inward at a position corresponding to the final molded body in the core metal (6), and a corresponding mold (
a ring-shaped recess opening outward at position 8);
cylindrical rings (3) of soft magnetic material fitted respectively;
Since the height of (4) is approximately the same as the height of the final molded body of cylindrical magnetic powder + 11, the magnetic field formed by the upper and lower permanent magnet bodies (2), (2) Since the lines of magnetic force will intensively pass through the positions of the rings (3) and (4), the magnetic field will be applied intensively to the magnetic powder (1) located between the rings (3) and (4). It is possible to increase the degree of orientation. In addition, since there is no non-magnetic material in the passage of the lines of magnetic force except for the parts of the core metal (6) and the mold (8) that contact the magnetic powder (1), the magnetic field passing through the magnetic powder (1) is The strength does not decrease, and the strength of the magnetic field present in the upper and lower permanent magnet bodies (2), (2) of the magnetic field generation source can be effectively utilized.

The layers of the core metal (6) and the mold (8) that are in contact with the final molded body of the magnetic powder (1) are pressurized by the soft magnetic material rings (3) and (4) that are fitted in those areas. The ring (3), (
4) is protected.

In this way, a molded body of a ring-shaped anisotropic magnet in which the magnetic powder fi+ having a radial anisotropy radially outward from the shaft is highly oriented is obtained.

In addition, when using, for example, a rare earth magnet as a permanent magnet used as a magnetic field generation source, rare earth magnets are hard and easily chipped, so in order to prevent them from coming into contact with other members and chipping,
Preferably, the surface of the magnet is thinly covered with a wear-resistant material.

A second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

In the first embodiment, a cylinder (41) for advancing and retracting the upper permanent magnet body (2) and a cylinder (43) for advancing and retracting the upper punch (7) are provided separately, and each is configured to be able to advance and retreat independently. However, in the second embodiment, the upper permanent magnet (
2) and the upper punch (7) are connected to one cylinder (43) so that both move forward and backward at the same time, and the ring-shaped anisotropy of the second embodiment The other parts of the magnet forming apparatus are the same as in the first embodiment.

In the second embodiment, as shown in FIG.
2) and the upper punch (7) simultaneously descend and enter the cavity. Eventually, the lower end of the upper punch (7) reaches the magnetic powder (1) previously housed in the cavity, and pressurization of the magnetic powder +11 begins, and the upper punch (7) advances further and press forming continues. Complete.

At this time, the upper permanent magnet body (2) is also attached to the cylindrical core metal (6).
The upper permanent magnet body (2)
The magnetic powder +11 gradually approaches the position where the degree of orientation of the magnetic powder +11 in the core metal (6) peaks, and during this time the degree of orientation of the magnetic powder (1) is improved. Of course, when putting the magnetic powder (1) into the cavity, the upper permanent magnet (2) is moved away from the rings (3) and (4), so the magnetism on the inner surface of the cavity is almost eliminated, and the magnetic powder (
1) can be easily inserted.

Also, when taking out the final molded body from the state shown in FIG. (43) and the cylinder (44) are synchronized to form an upper punch (7), a final formed body, and a lower punch (27).
can be raised at the same time to take out the final molded product.
Since the final compact is taken out with one of the upper and lower permanent magnets (2), (2) kept away from the rings (3), (4), the magnetism on the inner surface of the cavity is almost eliminated. The final molded body can be easily taken out.

In addition, in order to take out the final compact, not only the lower permanent magnet body (2) but also the upper permanent magnet body (2) are punched (7).
Alternatively, the lower punch (27) may be moved away from the rings (3) and (4) in advance, and then the lower punch (27) may be raised by the cylinder (44) and taken out.

FIG. 5 shows another embodiment, in which the cylinder (41) for advancing and retracting the lower permanent magnet body (2) in the second embodiment shown in FIGS. 3.4 is removed.

That is, in this embodiment, the lower permanent magnet body (2) has a core metal (
6), and does not move forward or backward within the core metal (6). Therefore, when taking out the final molded product, the upper permanent magnet body (2) is first inserted into the ring together with the upper punch (7). (3) and (4), and then the lower punch (27) is raised by the cylinder (44) to take out the final molded body.

The cavity defined by the core metal (6) and the mold (8) may have a rectangular or triangular cross section as long as it has a structure that allows a magnet for generating a magnetic field to be inserted into the core metal (6). It also applies to objects of arbitrary shape.

(Effects) Since the present invention is a molding device for a ring-shaped anisotropic magnet having the above-mentioned configuration, ■ the rings placed on the inner and outer sides of the final molded body of the magnetic book () are soft. It is a magnetic material, and at least one of the upper and lower permanent magnets of the magnetic field generation source is provided so that it can move forward and backward with respect to the inner surface of the core metal, so it is difficult to press the magnetic powder when putting it into the cavity. After molding, when taking out the final molded body, it is possible to work with one of the permanent magnet bodies kept away from the ring, and when putting the magnetic powder into the cavity,
The magnetic powder can be easily inserted without being attracted to a wide range of the inner surface of the cavity, and when the final molded product is taken out after pressure molding, the final molded product is attracted to the surface in contact with the core bar and the mold. Since it can be easily taken out without being damaged, a series of molding steps from putting the magnetic powder into the cavity to taking out the molded body after molding can be carried out reliably and easily.

■A ring-shaped recess that opens toward the inside of the position of the core metal corresponding to the position of the final compact of magnetic powder, and a ring-shaped recess that opens toward the outside of the corresponding mold position, respectively. A ring of soft magnetic material is fitted, so
The magnetic field generating source, which is installed on the shaft so that it can move forward and backward with the same polarity facing each other, is emitted from the upper and lower permanent magnet bodies and travels radially outward through the magnetic field lines, except for the part that comes into contact with the magnetic powder. material, the strength of the magnetic field does not decrease,
In addition, since the lines of magnetic force pass through the ring of soft magnetic material intensively, a high magnetic field can be applied intensively to the magnetic powder located between the two rings. At least one of the permanent magnets is provided so that it can move forward and backward relative to the inner surface of the core metal, and the upper and lower punches are also configured to be able to move in relative to the cavity, so that magnetic When press-forming the powder, the permanent magnet can be inserted into the inner surface of the core at the same time as punching or prior to punching, and a magnetic field is applied while the magnetic powder is freely moving and hanging. Therefore, since the magnetic powder is press-molded with a high degree of orientation, a ring-shaped anisotropic magnet with a good degree of orientation of the magnetic powder can be obtained. In addition, as mentioned above, the ring made of soft magnetic material is not in contact with the magnetic powder, so it will not be worn out by the FFI powder that is press-molded.
The durability of the molding equipment will also be improved.

■Since the magnetic field generation source is a permanent magnet, a coil and power source are required to generate the magnetic field, resulting in lower equipment costs and a simpler and more compact molding device structure. In addition, since a power source for the coil is not required, the installation floor space can be small, and power consumption for the coil is also not required, which is economical.

[Brief explanation of the drawing]

1 and 2 are front sectional views showing a first embodiment of the present invention, FIGS. 3 and 4 are front sectional views showing a second embodiment of the invention, and FIG. 5 is a front sectional view showing a first embodiment of the present invention. FIG. 6, a front sectional view showing another embodiment of the invention, is a front sectional view of a conventional ring-shaped anisotropic magnet forming apparatus. In the figure, (1) is magnetic powder, (2) is permanent magnet, (3),
(4) is a ring, (6) is a core metal, (7) is an upper punch, (
8) indicates the mold, and (27) indicates the lower punch. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] A cylindrical mold (8) made of a non-magnetic material;
) and a cylindrical core metal (6) made of a non-magnetic material that is loosely fitted into the metal mold (8) and a cylindrical core metal (6) made of a non-magnetic material that advances and retreats into an annular space defined between the mold (8) and the core metal (6). Upper and lower circular punches (7)
, (27), and the upper, Lower circular punch (7
), (27) are formed in a molding device for a ring-shaped anisotropic magnet in which pressure molding is carried out by relatively entering the magnet, and the ring-shaped anisotropic magnet is formed at the final position of the molded body in the mold (8) and opens outward. A ring-shaped recess, a ring (4) made of a soft magnetic material fitted into the recess, and the mold (8) in the core metal (6).
) a ring-shaped recess that opens inward and is formed at a position corresponding to the recess of the ring, a ring (3) made of a soft magnetic material fitted into the recess, and a ring (3) made of a soft magnetic material that is fitted into the inner surface of the core metal (6), respectively. a pair of upper and lower permanent magnets (2), which are arranged so that they can be combined with each other, and are arranged with the same poles facing each other, and at least one of which is provided so as to be movable relative to the inner surface of the core bar (6);
, (2) A molding device for a ring-shaped anisotropic magnet.