JP4484077B2 - Magnetic field forming apparatus and manufacturing method of ferrite magnet - Google Patents

Description

  The present invention relates to a magnetic field forming apparatus used when forming a ferrite magnet by wet forming and a method for manufacturing a ferrite magnet.

In order to produce ferrite (sintered) magnets, which are the mainstream magnets, a mixture of raw materials is calcined by calcination, and the resulting calcined product is pulverized to a submicron size. Thus, a material powder made of ferrite particles is obtained. Next, the material powder is compression-molded in a magnetic field with a mold (hereinafter referred to as magnetic field molding) to obtain a compact, and then the compact is sintered to obtain a ferrite magnet.
The magnetic field forming process is roughly divided into a dry method in which the material powder is dried and then formed, and a wet method in which the material powder is formed in a slurry state.

  When performing wet-type magnetic forming, the slurry pressure is detected in order to stably inject the slurry into the mold, and when the pressure reaches a predetermined set value, the slurry pressure is maintained at a predetermined value, The slurry is supplied to the mold for a predetermined time (see, for example, Patent Document 1).

Such control is effective for stably supplying the slurry to the cavity when the supply pressure is insufficient due to a change in the supply pressure due to the oil temperature of the device (pump) for supplying the slurry, the service life, or the like.
Moreover, since there is a difference between the models in the operation of the pump, there is an effect of reducing the influence of the difference between the models.

Japanese Utility Model Publication No. 60-120809

By the way, when the slurry is filled into the cavity, the slurry pressure reflects the driving force of dehydration if the temperature is constant, and the density difference of the material powder in the cavity and the difference in filling amount between the cavities (filling this) (Referred to as state). If the density difference between the material powders in the cavity increases during filling, the density difference also remains in the molded body, and cracks are likely to occur in the product after molding or after firing. When the difference in the filling amount between the cavities increases, as a result, the density of the molded body varies, and for example, a molded body having a low molding density tends to have defects such as cracks and chips. In addition, the variation in the density of the molded body leads to the variation in the dimensions of the fired body, resulting in a portion that does not hit the grindstone at the time of polishing. Cause problems.
When the operating pressure of the pump that fills the cavity with the slurry is constant, the slurry pressure increases when the dehydration resistance is large, and the slurry pressure decreases when the dehydration resistance is small. One factor that changes the dehydration resistance is the particle size (specific surface area) of the material powder. The smaller the particle size (the larger the specific surface area), the greater the dehydration resistance. In the process of pulverizing the raw material to generate the material powder, a certain degree of variation occurs in the degree of pulverization for each lot, and the particle size (specific surface area) of the material powder also changes.
According to the technique of Patent Document 1, even if the dehydration resistance changes, the slurry pressure can be kept constant, the dehydration driving force can be made constant, and the quality can be stabilized.

However, problems arise when the temperature of the slurry changes. The temperature of the slurry may vary within a range of 5 to 40 ° C., for example, depending on the season, the slurry storage environment, and the like.
Since the viscosity of water changes with temperature, when the same slurry pressure is used, the driving force for dehydration changes substantially. When the temperature increases, the viscosity of water decreases, and therefore, if the slurry pressure is the same, the dehydration driving force is substantially increased. On the other hand, when the temperature is lowered, the viscosity of water increases. Therefore, if the slurry pressure is the same, the driving force for dehydration is substantially reduced.
As described above, the slurry pressure greatly affects the quality, but the viscosity of water changes with temperature, and the driving force for dehydration changes substantially. Therefore, the optimum slurry pressure at the time of filling is affected by the temperature. That is, there arises a problem that the quality of the product changes due to temperature fluctuation.

  The present invention has been made on the basis of such a technical problem, suppresses fluctuations in the driving force of slurry dehydration during magnetic field molding, stabilizes the filling state of the material filling the cavity, and causes defects such as cracks. An object of the present invention is to provide a magnetic field forming apparatus and a ferrite magnet manufacturing method capable of suppressing the above.

  As a result of the diligent examinations by the present inventors for such a problem, while stabilizing the temperature of the slurry, according to the pressure of the slurry injected into the cavity, the operating pressure of the pump for feeding the slurry is controlled, It was found that stabilizing the driving force for dehydration is effective in solving the problem.

The present invention thus made is a magnetic field forming apparatus used when producing a ferrite magnet. In this magnetic field forming apparatus, a slurry in which a powder mainly composed of ferrite is dispersed in a dispersion medium is compressed in a mold. Molding is performed to form a molded body having a predetermined shape, and a magnetic field in a predetermined direction is applied to the slurry in the mold by a magnetic field generation source. And the temperature of a slurry is adjusted with a temperature adjustment part. The temperature adjusting unit can adjust the temperature of the slurry by adjusting the temperature of the mold. In this case, it is preferable to adjust the mold to a predetermined temperature set at 30 to 120 ° C. This is because if the temperature of the mold is lower than 30 ° C., the heating effect of the slurry is hardly exhibited. Although depending on the internal pressure of the cavity (that is, the pressure of the slurry), when the temperature of the mold exceeds 120 ° C., the water contained in the slurry boils. Therefore, the upper limit of the mold temperature is 120 ° C. or less, more preferably 100 ° C. or less, and still more preferably 80 ° C. or less. Therefore, a more preferable range of the mold temperature is 30 to 100 ° C, and a further preferable range is 30 to 80 ° C.
The temperature adjusting unit can also adjust the temperature of the slurry by adjusting the temperature of the supply pipe for injecting the slurry into the mold. In addition, the temperature of the portion where the slurry flows in the pump for feeding the slurry to the supply pipe may be similarly adjusted by the temperature adjusting unit.
The present invention is characterized in that, in such a magnetic field forming apparatus, the pressure control unit controls the operating pressure of the pump based on the pressure of the slurry injected into the mold. That is, the pressure control unit feedback-controls the operating pressure of the pump so that the pressure of the slurry injected into the mold is within a predetermined range. The dehydration resistance of the slurry injected into the mold varies depending on the particle size (specific surface area) of the material powder. It is possible to absorb the particle size (specific surface area) of the material powder and the like by adjusting the operating pressure of the pump according to the fluctuation of the pressure of the slurry.
The present invention also includes a stroke sensor that detects a stroke of the mold when the pressurization of slurry with the mold is completed, and a pump operation time that is controlled based on the stroke of the mold detected by the stroke sensor. And an operation time controller for adjusting a time for filling the mold with the slurry.
In this manner, the temperature adjusting unit and the pressure control unit stabilize the driving force for dehydrating the slurry from the mold by controlling the temperature of the slurry and the operating pressure of the pump.

In the present invention, a slurry obtained by dispersing a powder mainly composed of ferrite in a dispersion medium is adjusted to a temperature and a slurry pressure within a preset range and filled in a cavity, and in a magnetic field in a predetermined direction. It has a molding process for obtaining a molded body by pressure molding and a firing process for obtaining a ferrite magnet by firing the molded body . In the molding process, the stroke is performed when the pressurization of the slurry by the mold is completed. Based on the stroke of the mold detected by the sensor, the operation time controller adjusts the filling time of the slurry into the mold, and the pressure of the slurry injected into the mold is within a predetermined range. It is also possible to provide a method for manufacturing a ferrite magnet, in which the operating pressure of a pump for injecting the slurry is feedback controlled .

  According to the present invention, it is possible to suppress fluctuations in the driving force for dehydration during slurry filling in magnetic field molding, thereby stabilizing the amount and filling state of the material powder filling the cavity and suppressing defects such as cracks. It becomes possible.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is a diagram showing an example of the flow of a manufacturing process of a ferrite magnet in the present embodiment. In addition, it cannot be overemphasized that the manufacturing process of the ferrite magnet shown in this Embodiment is only an example, and can change suitably.
As shown in FIG. 1, in order to manufacture a ferrite magnet, first, a mixture of raw materials at a predetermined blending ratio is calcined to be converted into ferrite (steps S101 and S102). As the raw material, oxide powder or a compound that becomes an oxide by firing, for example, carbonate, hydroxide, nitrate, or the like is used. The calcination is usually performed in an oxidizing atmosphere such as air.

  Next, the obtained calcined body is pulverized through a coarse pulverization step (step S103) to obtain a calcined powder made of ferrite particles. Next, an additive is appropriately added to the calcined powder, and it is pulverized to a submicron size through a fine pulverization step (step S104) to obtain a finely pulverized powder mainly composed of magnetoplumbite type ferrite. The coarse pulverization step and the fine pulverization step may be performed by a wet method or a dry method. However, since the calcined body is generally composed of granules, it is preferable to perform the coarse pulverization step dry and then the fine pulverization step wet. In that case, after roughly pulverizing the calcined body to a predetermined particle size or less in the coarse pulverization step, a pulverization slurry containing coarsely pulverized powder and water is prepared in the fine pulverization step, Fine grinding is performed until the particle size is reached.

Thereafter, a finely pulverized powder is dispersed in a dispersion medium to prepare a slurry (slurry) having a predetermined concentration, and this is subjected to magnetic field molding. When wet pulverization is performed in the fine pulverization step, a slurry having a predetermined concentration may be prepared by concentrating the slurry in the dehydration step (step S105).
Here, as the dispersion medium, water, hexane, toluene, p-xylene, methanol or the like can be used.

Then, after the slurry is kneaded (step S106), the slurry is poured into a mold, and compression molding is performed while applying a magnetic field in a predetermined direction to perform magnetic field shaping (step S107).
Thereafter, the obtained molded body is fired and sintered to obtain a ferrite magnet (step S108). Thereafter, a ferrite magnet as a product is completed through processing into a predetermined shape (steps S109 to S110).

2 and 3 are diagrams showing a schematic configuration of the magnetic field shaping apparatus 10 used in the magnetic field shaping process of step S107 as described above.
The magnetic field forming apparatus 10 compresses a slurry prepared at a predetermined concentration in a magnetic field, thereby orienting ferrite particles to form a ferrite magnet having a predetermined shape. As shown in FIG. 2, the magnetic field forming apparatus 10 has a plurality of cavities 11 in order to form a plurality of ferrite magnets.

FIG. 3 is a cross-sectional view targeting one cavity 11 of the magnetic field shaping apparatus 10. As shown in FIG. 3, the magnetic field molding apparatus 10 includes an upper mold 12 </ b> A, a lower mold 12 </ b> B, and a mortar mold 12 </ b> S as the mold 12. At least one of the upper mold 12A and the lower mold 12B is operable in a direction in which the upper mold 12A and the lower mold 12B are moved toward and away from each other using a drive cylinder (not shown) as a drive source. In the present embodiment, the lower mold 12B moves up and down with a predetermined stroke relative to the upper mold 12A.
In addition, the mortar mold 12S may be fixed, or may be movable up and down.

  As shown in FIG. 2, an injection path 13 for injecting slurry into each cavity 11 is formed in the mortar mold 12 </ b> S. The injection path 13 distributes and injects the slurry fed by the pump 16 from the material container 14 provided outside through the material supply pipe (supply pipe) 15 into the individual cavities 11.

As shown in FIG. 3, each lower mold 12 </ b> B is configured to compression-mold the slurry into a predetermined shape in the cavity 11 at the stroke end position. Here, the mortar die 12S is provided with a seal member 17 for sealing a gap with the lower die 12B.
A filter cloth 18 for discharging moisture contained in the slurry from the cavity 11 is sandwiched between the mating surfaces of the upper mold 12A and the mortar mold 12S. The moisture contained in the slurry is guided to the outside of the upper die 12A and the die 12S from the mating surface of the upper die 12A and the die 12S through the filter cloth 18, thereby dehydrating.
A magnetic field generating source such as a magnetic field generating coil (not shown) is provided in the vicinity of the upper mold 12A so that a magnetic field in a predetermined direction can be applied.

In the magnetic field molding apparatus 10 having the above-described configuration, the slurry kneaded in step S106 is passed between the material container 14 and the material supply pipe 15 and the injection path 13 by the pump 16, and between the upper mold 12A and the lower mold 12B. Are distributed and supplied to each cavity 11. When a predetermined amount of slurry is filled in the cavity 11 while applying a magnetic field generated by a magnetic field generating coil or the like (not shown), the lower mold 12B is operated and a predetermined pressure is applied by the upper mold 12A and the lower mold 12B. Then, the moisture contained in the slurry is guided to the outside through the filter cloth 18, thereby forming into a predetermined shape while performing dehydration.
And after completion | finish of shaping | molding, the molded object shape | molded by the predetermined shape is obtained by opening upper mold 12A and lower mold | type 12B, and removing.

  Now, in the magnetic field shaping | molding apparatus 10 in this Embodiment, as a temperature adjustment mechanism (temperature adjustment part) for adjusting the temperature of a slurry, the metal mold | die 12 (for example, die 12S), the material supply pipe | tube 15, and the pump 16 are included. The slurry supply chamber 16a is provided with temperature sensors 30A, 30B, 30C such as thermocouples. The temperature of the mold 12, the material supply pipe 15, and the pump 16 varies depending on the ambient atmosphere temperature and the slurry temperature. The temperature sensors 30A, 30B, and 30C detect the temperatures of the mold 12, the material supply pipe 15, and the pump 16. The temperature sensors 30 </ b> A, 30 </ b> B, and 30 </ b> C output an electrical signal corresponding to the detected temperature to the temperature controller 31.

  The mold 12 (for example, the lower mold 12B), the material supply pipe 15, and the pump 16 are provided with temperature adjusting members 32A, 32B, and 32C for adjusting the temperature by heating or cooling each. . For example, a heating wire, a ceramic heater, or the like can be used for the temperature adjustment members 32A, 32B, and 32C. Further, as the temperature adjusting members 32A, 32B, and 32C, a liquid cooling type that heats or cools the mold 12, the material supply pipe 15, and the pump 16 with a liquid medium may be used. Any other temperature adjusting members 32A, 32B, and 32C may be used as long as the mold 12, the material supply pipe 15, and the pump 16 can be heated or cooled. It is preferable to do this.

The operation of the temperature adjusting members 32A, 32B, 32C is controlled by the temperature controller 31. In the temperature controller 31, the temperature adjustment member 32 </ b> A is set so that the mold 12, the material supply pipe 15, and the pump 16 detected by the temperature sensors 30 </ b> A, 30 </ b> B, and 30 </ b> C are within a predetermined temperature range set in advance, for example, 35 to 50 ° C. , 32B, 32C are controlled independently. For example, the temperature adjusting member 32A is controlled to be 35 ± 2 ° C., the temperature adjusting member 32B is controlled to 45 ± 2 ° C., and the temperature adjusting member 32C is controlled to be 50 ± 2 ° C. Thereby, the temperature of the slurry supplied from the pump 16 to the cavity 11 of the mold 12 through the material supply pipe 15 can be stabilized. By stabilizing the slurry temperature, the viscosity of water can be stabilized and the driving force for dehydration can be stabilized. As a result, the filling state of the material powder filled in the cavity 11 can be stabilized.
Here, such temperature adjustment by the temperature controller 31 is not necessarily performed by the mold 12, the material supply pipe 15, and the pump 16. For example, only the mold 12, only the material supply pipe 15, and the like are performed. Alternatively, it may be performed at another part.

  Further, in the magnetic field forming apparatus 10, a slurry filling pressure control mechanism (pressure control unit) that controls the pressure of the slurry in the material supply pipe 15 (hereinafter referred to as slurry filling pressure) is provided near the mold 12. A pressure sensor 40 for detecting the slurry filling pressure in the material supply pipe 15 is provided. An electrical signal corresponding to the slurry filling pressure detected by the pressure sensor 40 is sent to the filling pressure controller 41.

When the pump 16 starts operation at a predetermined speed for filling the slurry, the filling pressure controller 41 starts control and controls the operating pressure of the pump 16 based on the slurry filling pressure detected by the pressure sensor 40. To do.
The slurry to be subjected to magnetic field molding is obtained by dispersing material powder in a dispersion medium such as water, but due to the difference in specific gravity between the dispersion medium and the material powder, In the lower part, the concentration of the material powder in the slurry, that is, the slurry concentration is different. For this reason, even if the slurry is supplied from the same material container 14, the slurry concentration varies with time. When the slurry concentration varies, the slurry filling pressure also varies. If the slurry filling pressure is too low, the filling amount between the cavities 11 may vary, and a density difference of the material powder in the cavities 11 may occur. Further, if the slurry filling pressure becomes too high, the dehydration driving force becomes too large, and as a result, the dehydration speed becomes too fast and unevenness of dehydration occurs, resulting in the density difference of the material powder in the cavity 11. . The difference in the density of the material powder leads to the occurrence of abnormal baked dimensions and cracks in the molded body.
Therefore, when the detected slurry filling pressure is lower than a predetermined lower limit threshold, the filling pressure controller 41 increases the operating pressure of the pump 16 to increase the slurry filling pressure. When it is higher than the predetermined upper limit threshold value, the predetermined material powder (ferrite) is supplied into the cavity 11 by lowering the operating pressure of the pump 16 and lowering the slurry filling pressure.
Such control by the filling pressure controller 41 is so-called feedback control, and the pump operating pressure is controlled so that the slurry filling pressure (for example, 3 ± 0.2 MPa) set during filling is obtained. The setting of the slurry filling pressure is appropriately set according to the temperature setting so as to optimize the quality.

  Further, the magnetic field forming apparatus 10 is provided with a stroke sensor 50 that detects the stroke of the mold 12 (in the present embodiment, the stroke of the lower mold 12B) as a slurry filling time adjusting mechanism. The mold 12 is configured to pressurize until the operating pressure of a drive cylinder (not shown) for stroking the lower mold 12B reaches a predetermined set pressure. When the dehydration resistance from the slurry changes according to the particle size (specific surface area) of the material powder or the clogging condition of the filter cloth 18, the amount of the material powder filled in the cavity 11 changes accordingly. As a result, the dimensions (thicknesses) of the molded bodies obtained after pressing differ. In order to detect this variation in the dimensions of the molded body, the stroke sensor 50 detects the stroke (position) of the lower mold 12B at the time of completion of pressurization.

  An electrical signal corresponding to the stroke of the lower mold 12 </ b> B detected by the stroke sensor 50 is sent to the operation time controller 51. The operation time controller 51 controls the operation time of the pump 16 based on the stroke of the lower mold 12 </ b> B detected by the stroke sensor 50. When the stroke of the lower mold 12B detected by the stroke sensor 50 is larger than a predetermined upper limit threshold value set in advance, the molded body to be obtained becomes thin, so that the operation time of the pump 16 is lengthened and the slurry filling time is increased. If the stroke of the lower die 12B is smaller than a predetermined lower limit threshold value, the resulting molded body becomes thicker, so the pump 16 is shortened to shorten the slurry filling time. Shorten. This control by the operation time controller 51 is also feedback control, and the pump for the next press is performed based on the stroke amount of the lower die 12B immediately before the press with the die 12 a predetermined time (or even once). Adjust the 16 operating times as needed.

As described above, in the magnetic field forming apparatus 10, the temperature of the slurry in the cavity 11 of the mold 12 is stabilized by the temperature adjustment mechanism including the temperature sensors 30A, 30B, 30C, the temperature controller 31, and the temperature adjustment members 32A, 32B, 32C. I tried to plan. In addition, in the magnetic field forming apparatus 10, the slurry filling pressure adjustment mechanism including the pressure sensor 40 and the filling pressure controller 41 controls the operating pressure of the pump 16 according to the slurry filling pressure, and adjusts the slurry filling pressure into the cavity 11. I did it. This makes it possible to stabilize the driving force for dehydration from the cavity 11 regardless of variations in the degree of pulverization in the step of pulverizing the raw material to produce the material powder. Further, it is possible to absorb the change in fluidity due to the time-dependent fluctuation of the slurry concentration at the upper part and the lower part in the material container 14, and as a result, the filling state of the material powder filled in the cavity 11 can be stabilized and obtained. In such a ferrite magnet, defects such as cracks can be suppressed.
In addition, in the magnetic field forming apparatus 10, the slurry filling time adjustment mechanism including the stroke sensor 50 and the operation time controller 51 suppresses fluctuations in the molded body size caused by fluctuations in the dehydration resistance from the cavity 11, thereby stabilizing Can be performed.

Here, the effects of controlling the temperature of the slurry and controlling the filling internal pressure were confirmed, and the results are shown below.
First, the relationship between the temperature of the slurry and the state of filling into the cavity was examined.
For this reason, a slurry was prepared by a process as shown in FIG. Water was used as a dispersion medium for the slurry. Then, the slurry having various temperatures as shown in Table 1 was injected into a disk-shaped cavity having a diameter of 30 mm by operating the pump so that the slurry pressure at the time of filling was constant.
At this time, the time required to fill the cavity with a predetermined amount of slurry was measured. The results are shown in Table 1.

  As shown in Table 1, the higher the slurry temperature, the shorter the time required to fill the cavity with the slurry. Thus, even if the slurry pressure at the time of filling is constant, the slurry temperature It is clear that the driving force for substantial dehydration changes according to the above. Therefore, it is possible to easily understand the necessity of stabilizing the temperature of the slurry in order to stabilize the filling state.

Next, magnetic field shaping was performed using the slurry as described above in the magnetic field shaping apparatus having the configuration as shown in FIG. For magnetic field forming, a mold 12 having a plurality of cavities 11 was used, and the temperature adjustment mechanism was used to adjust and control the mold 12, the material supply pipe 15, and the pump 16 to 35 ° C. In addition, the internal pressure of the material supply pipe 15 was controlled to be 3 MPa by the slurry filling pressure adjusting mechanism (Example).
For comparison, the control by the temperature adjustment mechanism and the slurry filling pressure adjustment mechanism was not performed, and the pump 16 was operated at a constant operating pressure of 3 MPa to perform magnetic field shaping (Comparative Example 1).
Further, the temperature adjustment mechanism was not controlled, and the magnetic field forming was performed by controlling the internal pressure of the material supply pipe 15 to be 3 MPa by the slurry filling pressure adjustment mechanism (Comparative Example 2).
And in each of the comparative example 1, comparative example 2, and an Example, magnetic field shaping | molding was repeated 1500 cycles, the obtained molded object was baked, the sintered body was processed, and the ferrite magnet was obtained.

Next, the ferrite magnet obtained as described above was inspected for occurrence of defects such as cracks. The result is shown in FIG.
As shown in FIG. 4, in the example in which the slurry temperature adjustment and the slurry filling pressure adjustment were performed, only the slurry temperature adjustment and the slurry filling pressure adjustment were performed, and only the slurry filling pressure adjustment was performed. Compared with the comparative example 2 performed, defects such as lateral cracks and peeling (defects in which the material adheres to the cavity 11 when demolding from the cavity 11) are clearly reduced, yield is greatly improved, and the driving force for dehydration It was confirmed that stabilizing the quality leads to improvement of quality.

It is a figure which shows the manufacturing process of the ferrite magnet in this Embodiment. It is a figure which shows the structure of the metal mold | die of the magnetic field shaping | molding apparatus which has several cavities. It is sectional drawing which shows a part of magnetic field shaping | molding apparatus. It is a figure which shows the difference in the incidence rate of the defect by the presence or absence of temperature adjustment of a slurry, and filling pressure adjustment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Magnetic field shaping | molding apparatus, 11 ... Cavity, 12 ... Mold, 12A ... Upper mold, 12B ... Lower mold, 12S ... Mortar type, 13 ... Injection path, 14 ... Material container, 15 ... Material supply pipe (supply pipe), DESCRIPTION OF SYMBOLS 16 ... Pump, 16a ... Slurry supply chamber, 30A, 30B, 30C ... Temperature sensor, 31 ... Temperature controller, 32A, 32B, 32C ... Temperature adjustment member, 40 ... Pressure sensor, 41 ... Filling pressure controller, 50 ... Stroke sensor, 51 ... Operating time controller

Claims (6)

A magnetic field forming apparatus used when manufacturing a ferrite magnet,
A mold that compresses a slurry in which a powder mainly composed of ferrite is dispersed in a dispersion medium, and forms a molded body having a predetermined shape;
A magnetic field generating source for applying a magnetic field in a predetermined direction to the slurry in the mold;
A temperature adjusting unit for adjusting the temperature of the slurry;
A pump for injecting the slurry into the mold;
A pressure control unit for controlling the operating pressure of the pump based on the pressure of the slurry injected into the mold;
A stroke sensor for detecting a stroke of the mold at the time when the pressurization of the slurry is completed with the mold;
An operation time controller that controls an operation time of the pump based on a stroke of the mold detected by the stroke sensor and adjusts a filling time of the slurry into the mold, and
The pressure control unit feedback-controls the operating pressure of the pump so that the pressure of the slurry injected into the mold is within a predetermined range .   The magnetic field forming apparatus according to claim 1, wherein the temperature adjusting unit adjusts the temperature of the slurry by adjusting the temperature of the mold.   The magnetic field shaping apparatus according to claim 2, wherein the temperature adjustment unit adjusts the mold to a predetermined temperature set within a range of 30 to 120 ° C. The temperature adjustment unit, by adjusting the temperature of the supply tube for injecting the slurry into the mold, in any one of claims 1 to 3, characterized in that adjusting the temperature of the slurry The magnetic field shaping apparatus described. The temperature adjusting unit and the pressure control unit control a temperature of the slurry and an operating pressure of the pump in order to stabilize a driving force for dehydrating the slurry from the mold. Item 5. The magnetic field shaping apparatus according to any one of Items 1 to 4. A molding process in which a slurry obtained by dispersing powder mainly composed of ferrite in a dispersion medium is adjusted to a temperature and pressure within a preset range, and is molded by pressure in a magnetic field in a predetermined direction. When,
A firing step of obtaining a ferrite magnet by firing the molded body,
Have
In the molding step, based on the stroke of the mold detected by a stroke sensor at the time when the pressurization of the slurry by the mold is completed, the operation time controller adjusts the filling time of the slurry into the mold,
The pressure of the slurry to be injected into the mold, so as to be within a predetermined range, the production of ferrite magnets, characterized in that the feedback control of the working pressure of the pump for injecting the slurry into the mold Method.

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