JPS6136452B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention accommodates a workpiece made of a ferromagnetic or non-magnetic conductive material together with a workpiece such as a solid, powder, or liquid in a processing container. The present invention relates to an improvement in an electromagnetic processing device that processes objects to be processed, such as crushing, mixing, stirring, etc., by causing violent random motion in working beads by applying a moving magnetic field.

In the above-mentioned processing device, processing of the object to be processed is performed by movement of working beads in a container or collision of working beads, etc.
In order to carry out such processing efficiently, it is desirable that the working beads be uniformly affected by the moving magnetic field at all positions within the processing container to perform violent random movements.

An apparatus as shown in FIG. 1 has already been proposed as this type of processing apparatus. That is, in FIG. 1, reference numeral 1 denotes a processing container containing a workpiece 2 and a large number of working beads 3 made of ferromagnetic or non-magnetic conductive material, for example, in the shape of a spindle. Moving magnetic field generating devices 4 and 5 are arranged above and below to face each other, and the moving directions of the generated magnetic fields are determined to be mutually opposite directions as shown by arrows φ ₁ and φ ₂ . These moving magnetic field generators 4 and 5 are well known as so-called linear motors, and are constructed by, for example, winding three-phase AC windings to form multiple poles along an iron core, and are powered by a multi-phase AC power source. Moving magnetic fields φ ₁ and φ ₂
generate.

With the configuration shown in Figure 1, working bead 3 placed in moving magnetic fields φ ₁ and φ ₂ is subjected to electromagnetic force due to magnetization and eddy current, and working bead 3 rotates around its own center of gravity. At the same time, in addition to the propulsive force and levitation force caused by the moving magnetic fields φ ₁ and φ ₂ in the direction of the moving magnetic fields, collisions between the working beads and collisions with the wall surface of the container are also added, causing the movement inside the container 1. Produces violent random movements. Due to this random movement, the object 2 to be processed is pulverized, mixed, or agitated by collision with the working bead 3 or the like.

Here, the magnetic field distribution in the working space between the moving magnetic field generators 4 and 5 where the container 1 of the apparatus shown in FIG. 1 is placed is conceptually shown in FIG. 3. That is, in FIG. 3, the moving magnetic field generators 4, 5
In order to generate a moving magnetic field in the directions indicated by arrows φ ₁ and φ ₂ , three-phase AC windings indicated by U-X, V-Y, and W-Z are installed in the coil slot 7 of the iron core 6, as shown in FIG. The wire 8 is wound, for example, in a wave-wound manner, and the phase sequence is U-V ¹ -W to the right in the device 4.
-U ¹ -V-W ¹ -U (U and U ¹ , V and V ¹ , W and W ¹
(respectively indicate coil conductors in phase and opposite directions).
On the other hand, in the device 5, the U-
They are arranged like W ¹ -V-U ¹ -W-V ¹ -U. In addition, the pole pitch P of the winding (distance between U and U ¹ )
are both equal. In FIG. 3, the U-phase winding device 5 of the device 4 is shown facing the U-phase winding, but in the actual processing device, it is difficult to tell which phase winding is facing the U-phase winding. , does not affect its characteristics etc. Furthermore, in FIG. 3, both the moving magnetic field generators 4 and 5 are supplied with power from power sources with the same frequency, and the arrow H indicates the point where the current in the U-phase winding is maximum (the winding current is a sine wave). It shows the magnetic field vector at each point at the time. Furthermore, ellipse A represents the locus of the magnetic field vector H at this point when the winding current changes by one cycle. In other words, the magnetic field can be regarded as an elliptical rotating magnetic field that changes direction counterclockwise at most points in space.

Now, in Fig. 3, if we consider the magnetic field at each point on the straight line connecting the U-phase windings of devices 4 and 5, the magnetic field on this line is the in-phase current flowing to the two U-phase windings. The magnetic fields always cancel each other out, and the absolute value of the magnetic field strength shows a small value throughout one cycle. Particularly at the center point on this straight line, the magnetic fields from the two U-phase windings completely cancel each other out, and the magnetic field always becomes zero over time. This situation shows that the winding U ¹ is moved laterally by the pole pitch P from the opposite line of the winding U-U.
- It is exactly the same on the opposing wires of U ¹ , and in the moving magnetic field generators 4 and 5 with multi-pole windings, it is the same at all points on the opposing wires of in-phase winding U-U and U ¹ - U ¹ . A phenomenon appears. On the other hand, the third
In the figure, the magnetic field at a point on the line that is moved laterally by 1/2 of the pole pitch P from the opposing line of the winding U-U acts so that the magnetic fields are added to each other, contrary to the above, and the magnetic field strength increases. The absolute value of is larger than other points on the line. In this way, when the pole pitch P and power supply frequency of the moving magnetic field generators 4 and 5 are equal, the absolute value of the magnetic field in the working space is 1/2 of the pole pitch P along the direction of the moving magnetic field. The distribution is such that the strength repeats at intervals. In addition, in Figure 3,
In particular, we have explained the case where the U-phase windings of devices 4 and 5 are facing each other, but this tendency always occurs even if the V-phase windings of devices 4 and 5 or the W-phase windings are facing each other. This can be confirmed by tracking the relationship between the winding current and the magnetic field over time.

On the other hand, in order to observe how the working bead moves in the magnetic field distribution mentioned above,
As shown in Figure 1, the working bead 3 inside the container 1
The movement was photographed using a high-speed camera, and the following trends were observed. That is, each spindle-shaped working bead 3 rotates around its center of gravity due to the rotating magnetic field in the working space, and moves as a whole along the moving direction of the moving magnetic fields φ ₁ and φ ₂ . However, the range of movement in the direction of the moving magnetic field is mostly limited to the range of one pole pitch, and the overall movement path follows the path shown by arrow B in FIG. 3. As mentioned earlier, in Figure 3, this means that the windings U-U
This is because the absolute value of the magnetic field is small on the opposing line U ¹ - U ¹ , and there is insufficient electromagnetic force to drive the working bead 3 laterally across this area to the adjacent strong magnetic field area. 3
The motion of is centered on the part where the magnetic field is strong and the pole pitch P
The magnetic field is weak between the strong magnetic field regions in the processing container, and therefore a blind space where the working bead movement is weak is created. Moreover, as an electromagnetic processing device, due to the above phenomenon, the winding U in FIG.
- U and ¹ - U ¹ Processing actions such as crushing are not sufficiently performed at the opposing line points, and this is a major factor preventing improvement in processing performance.

The present invention has been made in view of the above points, and its purpose is to eliminate the drawbacks of the above-mentioned conventional devices,
The processing performance of the object to be processed may be improved by uniformly and randomly moving the working beads without forming a blind area of the magnetic field throughout the interior space of the processing container.

According to the present invention, this object is achieved by setting the power feeding frequencies to a pair of moving magnetic field generators disposed opposite to each other with a processing container in between to be different frequencies.

The present invention will be explained below based on illustrated embodiments.

In FIG. 4, moving magnetic field generators 4 and 5 each receive power from a three-phase power supply 9 to generate a moving magnetic field φ.
₁ and φ _2. In this case, a frequency converter 10 such as a cycloconverter is inserted in the power supply circuit path of one of the devices 4, and the device 5 receives power directly. The power supply frequency to the device 4 is changed with respect to the frequency of the power source 9.

Now, as an example where the power supply frequency to the device 4 is set to twice the power supply frequency to the device 5, the magnetic field distribution in the working space inside the processing container will be described with reference to FIG. FIG. 5 is drawn in correspondence with FIG. 3, which shows the conventional magnetic field distribution with the same feeding frequency, and the winding arrangement is the same as that in FIG. 2. The illustrated state shows the state at the time when the currents flowing through the U-phase windings of devices 4 and 5 are both in the positive or negative direction and the instantaneous values of the currents are equal, and the illustrated arrow H indicates the state at this point. It represents the magnetic field vector at each point. In addition, each circle in the figure represents a vector locus for one cycle of the sine wave current as described in Figure 3, but among these, the vector locus drawn as a double circle is particularly The small circle A' represents the vector locus during the period when the directions of the currents flowing through the in-phase windings of devices 4 and 5 are both positive or negative, and during this period the magnetic fields of devices 4 and 5 mutually interact. Interfere to cancel each other out. On the other hand, the great circle A'' represents a vector locus during a period when the current direction is positive and negative, and in this case, the magnetic fields act to strengthen each other. The vector locus at each point in the section is drawn as a single circle A because this point is far away from device 4 and changes at twice the frequency of device 4.
This shows that the influence of the magnetic field is small, and the locus circle of vector H is only slightly deformed, but does not become a double circle.

Comparing the magnetic field distribution shown in Figure 5 above with the magnetic field distribution of the conventional system shown in Figure 3, it is found that the windings U-U and ^U1 - ^U1 , where the magnetic field is always zero when fed at the same frequency, are At the midpoint of the opposing line points, the fifth
According to the figure, since the frequencies of the two U-phase windings are different from each other, the state of zero magnetic field is only for a moment when both current waveforms intersect in one cycle of the rotating magnetic field, and the magnitude always changes. A rotating magnetic field comes to be formed. Also, even on a line moved laterally from this line by 1/2 of the pole pitch, although the phase of the magnetic field is different, the shape of the vector locus and the absolute value of the magnetic field are the same as on the line opposite the winding U-U, which is the same as in the conventional method. This eliminates the local strength of the magnetic field within the processing container that is created in the case of this method, and eliminates the magnetic dead space that impedes the movement of the working beads. As a result, the working piece can move sufficiently randomly in all parts of the space of the processing container, and processing performance such as crushing and mixing can be improved. Note that the power feeding frequency ratio to the devices 4 and 5 is not limited to the illustrated 2:1, but the same effect can be obtained by setting it to any ratio. In addition to the above-mentioned setting of the power supply frequency, the opposing moving magnetic field generator 4
If we set the pole pitches of and 5 to be different from each other,
Further effects can be expected.

As described above, according to the present invention, the power feeding frequencies to the opposing moving magnetic field generators are set to different frequencies. Therefore, when power is fed at the same frequency, the magnetic field inside the processing container is The magnetic field distribution, in which the strength of the magnetic field alternates at intervals of 1/2 the pole pitch, is improved evenly in almost the entire space inside the container, and the magnetic blind space that impedes the movement of the working bead is eliminated. In this way, sufficient processing actions such as crushing and mixing are performed in the entire space inside the processing container.
The performance of the electromagnetic processing device can be improved.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram of the electromagnetic processing device that is the object of the present invention, Fig. 2 is a winding diagram of the moving magnetic field generator shown in Fig. 1, Fig. 3 is a conventional magnetic field distribution diagram in the working space, and Fig. 4 is The figure is a power supply circuit diagram of an embodiment of the present invention, and FIG. 5 is a magnetic field distribution diagram of the embodiment of the present invention corresponding to FIG. DESCRIPTION OF SYMBOLS 1... Processing container, 2... Processing object, 3... Working piece, 4, 5... Moving magnetic field generator, 8... Winding wire,
9...Power supply, 10...Frequency converter, _φ1 , _φ2 ...Moving magnetic field, H...Magnetic field vector.

Claims (1)

[Claims] 1. A processing container containing working beads made of ferromagnetic or non-magnetic conductive material, each of which has a winding powered by a multiphase AC power source, and whose moving magnetic field directions are set opposite to each other so that the working beads are arranged on both sides of the processing container. and a pair of moving magnetic field generators disposed opposite to each other, the working beads are caused to move randomly by electromagnetic force based on the action of the moving magnetic field generated by supplying power to the moving magnetic field generators, and are moved toward the processing container. An electromagnetic pulverization, mixing, and agitation processing apparatus for pulverizing, mixing, stirring, etc., a housed object to be processed, characterized in that the power supply frequencies to the pair of moving magnetic field generators are set to different frequencies. Equal processing equipment.