JPS628217B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention accommodates objects to be processed such as solids, particles, liquids, etc. and a working piece made of ferromagnetic material in a processing container, and moves the object from the outside with respect to the container. The present invention relates to a working piece of a moving magnetic field type processing apparatus that performs processing such as crushing, mixing, stirring, etc. of a workpiece by causing intense random motion in the working piece by applying a magnetic field.

As this type of moving magnetic field processing apparatus, those shown in FIGS. 1 and 2 have already been proposed. In the figure, reference numeral 1 denotes a processing container containing, for example, crushed material 2 and a large number of working pieces 3 made of ferromagnetic material as objects to be processed. Magnetic field generators 4 and 5 are arranged facing each other, and their moving magnetic fields are φ ₁ ,
As shown by φ ₂ , they are set in opposite directions.
The moving magnetic field generators 4 and 5 are well-known as so-called linear motors (hereinafter, the "moving magnetic field generator" will be referred to as "linear motor"), and for example, rotate a three-phase AC winding 6. Like an electric machine, it is constructed by being wound in a coil slot on the magnetic pole side of an iron core 7, and receives power from a power source to generate moving magnetic fields φ ₁ and φ ₂ .

With this configuration, electromagnetic force due to magnetization, eddy current, etc. based on the interaction with the moving magnetic field acts on the working piece 3 placed in the moving magnetic fields φ ₁ and φ ₂ , thereby causing an electromagnetic force in the direction of the moving magnetic field. In addition to being subjected to translational force, levitation force, and rotational torque, the working pieces 3 undergo random motion within the container 1 due to collisions between the working pieces and collisions between the working pieces and the walls of the container. By this random movement of the working piece, the object 2 to be processed is subjected to processes such as crushing, mixing, and stirring. In this case, the pulverization process proceeds mainly by the collision between the working piece 3 and the object to be processed 2, and the mixing and agitation proceeds by the flow of the object to be processed along with the movement of the working piece. Therefore, in order to carry out these processes efficiently, the driving torque of the working piece based on the interaction with the moving magnetic field must be large, and the working piece must be dispersed and move over the entire area inside the container.
In addition, it is desired that the robot move in a complicated manner so as to effectively act on the object to be treated.

On the other hand, from the above point of view, the inventor conducted experiments using various shapes as the working piece 3, such as a steel ball, a dice-shaped body, a cylindrical body, and a prismatic body. It was found that there was a large difference in movement and processing performance. For example, steel balls move slowly and only roll along the wall of the container, while other balls of a certain shape may remain aligned along the wall of the container and remain stationary, or they may not move. However, processing performance such as crushing is low compared to the power supplied to the linear motor.

For this reason, there is a demand for a working piece having a shape suitable for use in a head processing device, which can fully satisfy the various functions required of the working piece.

In view of the above points, this invention analyzes the magnetic field in a working space sandwiched between two linear motors, analyzes the magnetic torque acting on a working piece placed in this magnetic field, and furthermore analyzes the magnetic torque acting on a working piece placed in this magnetic field. The purpose of this invention is to provide working pieces that work effectively in various types of processing based on considerations such as the effect that motion has on objects to be processed.

For this purpose, we will first consider the magnetic field in the working space sandwiched between linear motors 4 and 5 in the processing apparatus shown in FIG. In other words, Figure 3 shows linear motors 4 and 5 drawn based on the magnetic field analysis results.
It is a magnetic field distribution diagram in the action space between. In the figure, three-phase AC windings of U, V, and W phases are applied to the iron core 7 in a wave winding type, for example, and the phase order is U-V'-W- in the right direction in the linear motor 4.
In the order of U'-V-W'-U, one linear motor 5 moves in the right direction U-W'-V-U'-W.
-V'-U (U and U', V and V', and W and W' are the positive directions of the coil conductor wound in the coil slot,
It represents the opposite. ) are arranged like this. Further, the distance P between the conductors U-U' becomes the pole pitch. In the illustrated example, the U-phase windings face each other at the same position above and below, but the magnetic field characteristics do not change even if different phase windings face each other. In Fig. 3, the arrow H at each point indicates the magnetic field vector at that point when the current flowing through the U-phase windings of the linear motors 4 and 5 is at its maximum value (however, the winding current is a sine wave). show,
Further, an ellipse A surrounding the magnetic field vector H shows the locus of the magnetic field vector H due to one cycle of change in the winding current, and an arrow B shows the rotation direction of the magnetic field vector H.

As is clear from the magnetic field distribution diagram in Figure 3 above,
In the magnetic field of the space where the moving magnetic fields φ ₁ and φ ₂ of the linear motors 4 and 5 act from both sides, the moving magnetic fields φ ₁ and φ ₂ interfere with each other, and the magnetic field at each point is different from that at each point except for a specific point. It can be regarded as a rotating magnetic field that changes direction counterclockwise every moment and rotates once per cycle of current. The working pieces housed in a dispersed manner within the processing container are magnetized by the magnetic field shown in FIG. 3, and movement is caused by the electromagnetic force of their interaction. According to observation of the movement of the working piece in this case using a high-speed camera, the working piece 3 floats above the wall surface in the free space inside the container 1 and rotates on its axis. It has been confirmed that the portion close to the iron core surface moves in the directions of the moving magnetic fields φ ₁ and φ ₂ of the linear motor, and as a whole performs circular operation along the inner periphery of the container 1. This can naturally be inferred from the magnetic field distribution shown in FIG. Also, if you put the crushed material as the material to be processed into a container together with the working piece and observe the crushing situation,
The crushed material is strongly repelled mainly by collision with the rotating working piece, and it can be seen that it is crushed during this process. Note that when a working piece made of a non-magnetic conductive material such as stainless steel or aluminum in addition to a magnetic material is used as the working piece, its movement is weaker than that of a working piece made of a ferromagnetic material.

As is clear from the above observation results, the working piece receives a translational force, a levitation force, and a rotational torque for rotation from the linear motor. As described above, the electromagnetic force generation mechanism includes magnetic torque based on biased magnetization of the working piece and torque due to eddy current, but the contribution from the rear side is small. Moreover, what has the greatest effect on processing characteristics such as crushing is the magnetic torque that rotates the working piece itself. Therefore, let's consider in more detail the magnetic torque acting on the working piece placed in the magnetic field shown in Figure 3. Now, using a cylindrical working piece 3 as shown in Fig. 4 as a sample, this working piece 3 is
External magnetic field H from the direction of a certain angle α in the y-coordinate
(rotating magnetic field at each point in Figure 3), the working piece 3 is magnetized as J,
A magnetic torque T acts due to the external magnetic field H. The torque T in this case is given by the vector product of the external magnetic field H and the magnetic moment M due to the magnetization of the working piece. Also, since the magnetization J is the magnetic moment per unit volume, the torque T〓 is calculated by setting the volume of the working piece as v: T〓=v・J〓×H〓=v(Jx・Hx
−Jy・Hy). On the other hand, the magnetizations Jx and Jy are determined by the components Hx and Hy of the external magnetic field H in the x and y axis directions, and the respective demagnetization coefficients of the working piece 3 in the x and y axis directions. Moreover, as is well known, the demagnetization coefficient changes depending on the permeance coefficient, that is, the shape of the working piece 3, and the relationship between the two is D = 1/1 + P, where the demagnetization coefficient is D and the permeance coefficient is P, and in the x and y axis directions. The respective demagnetization coefficients are given by Dx=1/1+Px and Dy=1/1+Py. Here, FIG. 5 shows a relationship diagram showing the relationship between the dimension ratio and the permeance coefficient using the same cylindrical body as the working piece 3 shown in FIG. 4 as a sample. Among the characteristic lines in FIG. 5, 1 indicates the permeance coefficient for each dimension ratio when the sample is magnetized in the axial direction, and 1 indicates the permeance coefficient when the sample is magnetized in the diametrical direction. Note that the dimension ratio P/Q is the sample, P is the dimension in the magnetization direction, and Q is the dimension in the direction perpendicular to the magnetization direction. As is clear from Fig. 5, when working piece 3 in Fig. 4 is used as a sample, if its diameter is 1 and the length in the axial direction is 2, then the dimension ratio in the x-axis direction is 2. Therefore, its permeance coefficient is 6, whereas in the y-axis direction, the dimension ratio is 1/
2. Therefore, the permeance coefficient is about 1, and the permeance coefficient in the cylinder axis direction is much larger. Moreover, this tendency increases as the axial length increases relative to the diameter. This is the fourth
The longer and narrower the shape of the cylindrical working piece as shown in the figure, the easier it is to be magnetized in the length direction (the demagnetization coefficient is small). This suggests that the magnetic torque T, which rotates the working piece counterclockwise around the center of gravity until it coincides with , also becomes large.

Furthermore, when considering the processing operation performed in the processing apparatus shown in FIG. 1, when the working piece 3 rotates around its own center of gravity under the action of the moving magnetic fields φ ₁ and φ ₂ , The longer the axial length of the working piece 3, the greater the impact crushing force applied to the working piece 3 due to its moment of inertia. In this case, the more the mass distribution of the working piece is concentrated at both ends, the greater the moment of inertia and the greater the crushing force. Note that this effect is effective not only in pulverization processing but also in other mixing and stirring processing.

Based on the above, in order to obtain a working piece with good performance for use in the above-mentioned moving magnetic field processing device, the present invention has developed a working piece whose shape is longer than its cross-sectional dimension in the axial direction. It is constructed as a rod-shaped body with a large permeance coefficient in the axial direction.

Embodiments of the present invention will be described below based on the drawings.

FIG. 6 shows a basic embodiment, and FIGS. 7 and 8 show embodiments that are further developed from the embodiment shown in FIG. First, in FIGS. 6a and 6b, the working piece 3 is constructed as an elongated rod-shaped body whose axial length l is set to be sufficiently large with respect to its diameter dimension d. The permeance coefficient of such a shape is the fifth
As is already clear from the explanation of the figure, the permeance coefficient for magnetization in the longitudinal direction is much larger than that for magnetization in the diametrical direction.
Therefore, the magnetization in the diametrical direction is almost negligible, and the working piece becomes extremely easily magnetized in the longitudinal direction, and a large magnetic torque acts upon interaction with an external magnetic field.

When the workpiece 2 is pulverized as shown in FIG. 9 using such a rod-shaped working piece 3, the working piece 3, which is a magnetic material, will interact with the rotating magnetic field at each point in the magnetic field described in FIG. Due to the interaction, it generates a torque proportional to the area of its hysteresis loop, just like a hysteresis motor, and rotates around the center of gravity at high speed, while at the same time moving the inner circumference of the processing container 1 as a whole along the direction of the moving magnetic field. It moves in circles as shown in . Moreover, the magnetic torque acting on the working piece 3 that gives the above-mentioned rotational motion is larger than that of other shapes because the working piece 3 is configured as an elongated rod-like body as shown in FIG. Therefore, the crushing force applied to the object to be processed 2 upon collision with the object to be processed 2 becomes extremely large due to the effective effect of the rotational inertia moment of the working piece itself. On the other hand, due to the reinforcement of the rotational movement of the working piece 3 itself, the working piece 3 collides with each other, and with the help of the repulsive movement caused by the collision between the working piece 3 and the wall surface of the container 1, the working piece 3 moves in an extremely complicated and violent manner inside the container. Do random exercise. In this way, processing performance such as crushing, mixing, stirring, etc. is significantly improved.

Further, in the embodiments shown in FIGS. 7 and 8, a weight portion 8 as a weight portion is formed at both ends of the working piece main body which is an elongated rod-shaped body. Therefore, the mass distribution of the working piece 3 is concentrated at both ends thereof, and while making the most of the performance of the basic embodiment shown in FIG. It is possible,
This is an extremely effective means especially when performing impact crushing treatment.

In each of the illustrated embodiments, the working piece 3 is a round rod-like body with a circular cross-sectional shape, but it goes without saying that similar effects can be obtained even if the working piece 3 is configured as a square rod-like body.

As described above, according to the present invention, a working piece with excellent performance that can fully satisfy the various functions required of a working piece can be obtained, and by employing this working piece, the processing performance of a moving magnetic field type processing device can be improved. The practical effect is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a moving magnetic field type processing device, Fig. 2 is a sectional view taken in the direction of the arrow in Fig. 1, and Fig. 3 is a
Figure 4 is a diagram explaining the magnetization of the working piece, Figure 5 is a diagram showing the relationship between the dimension ratio of the sample and the permeance coefficient, and Figures 6 a, b to 8 a, b are respectively A side view and a sectional view showing the shape of a working piece according to an embodiment of the present invention, and FIG. 9 is an explanatory view of the operation of the processing apparatus. 1... Processing container, 2... Processing object, 3... Working piece, 4, 5... Moving magnetic field generator, 8
... Weight part, d ... Cross-sectional dimension of working piece, l ... Length dimension in axial direction.

Claims (1)

[Claims] 1. A processing container is installed between a pair of moving magnetic field generating devices that are arranged opposite each other with moving magnetic field directions set in opposite directions, and a working piece made of a magnetic material is placed there together with an object to be processed. The working piece is driven by electromagnetic force based on the interaction with the moving magnetic field of the moving magnetic field generator to crush, mix, and
A working piece of a moving magnetic field type processing device that performs processing such as stirring, and is configured as a rod-shaped body whose length in the axial direction is longer than its cross-sectional dimension and whose permeance coefficient in the axial direction is large. A working piece of a moving magnetic field type processing device characterized by the following. 2. A working piece for a moving magnetic field type processing device according to claim 1, wherein the rod-shaped body is provided with weight portions at both ends thereof.