JPH0647304A - Batch type planet ball mill with temperature control mechanism - Google Patents

Abstract

PURPOSE:To accelerate chemical reaction in the inside of a mill pot, keep the quality of the treated powder constant, and develop a new quality material and manufacture a high grade material by providing a temperature controlling mechanism to control the temperature of the mill pot, which is kept in a heat insulating condition, to be a desired level directly or through a heating and cooling medium. CONSTITUTION:In a batch type planet ball mill, a plurality of mill pots 4 which rotate on a revolution shaft 21 following the rotation of the revolution shaft are evenly installed in the circumference of the revolution shaft 21 and each of the mill pots rotates on its self-revolution axis 41 and thus the powder and granules, which are seated in the mill pots 4 together with a medium, are efficiently treated. The temperature of the mill pots 4, which are kept in a heat insulating condition, is controlled to be a desired level directly or through a heating and cooling medium by a temperature controlling mechanism 5. Consequently, the mill pots 4 are kept under a heat insulating condition heated or cooled indirectly or directly by the use of an electric heating wire, etc., and their insides are respectively kept at the most optimum temperatures for the purposes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary ball mill, and more particularly, to a powder which has a mill pot fitted in a mill casing and which seals the treated powder together with a medium to carry out fine pulverization and mechanical alloying to change the molecular structure. The present invention relates to a batch type planetary ball mill that performs processing.

[0002]

2. Description of the Related Art The general structure of a planetary ball mill is, as shown in FIG.
A plurality of mill pots 4a that revolve around 1a
The mill pots are arranged evenly around 1a (symmetrically if there are two, radially equidistant from the main shaft if there are three or more), and the mill pot itself also rotates about its own rotation axis 41a.
Specifically, as shown in FIGS. 3 (A) and 3 (B), the driving force of the motor 23a is a pair of sprockets 1.
01 and the transmission chain 102 are transmitted to the revolution shaft 21a. The rotation shaft 41a attached to the mill pot 4a is rotatably attached to the mill body 1a fixed to the revolution shaft. On the other hand, the sun sprocket 24a fixed so as not to rotate on the same axis as the revolution shaft 21a and the planetary sprocket 25a provided around the rotation shaft are connected by the conduction chain 104,
The rotation shaft 41a is revolved while revolving, and the mill pot fixed to the rotation shaft is rolled. When the medium B and the treated powder S are housed in the mill pot 4a, and the motor is rotated, the mill pot revolves around its own axis, and the centrifugal acceleration causes the medium to move in a unique manner to finely pulverize the powder or to give a unique chemistry. A general reaction. That is, in the ordinary rolling ball mill, the medium balls and the powder particles cause a cascade motion in one rolling cylinder, and the particles are crushed and crushed by the gravity drop, and the planetary ball mill is crushed. Produces a fine powder with excellent particle size distribution in a short time because the centrifugal force due to high-speed revolution and rotation and the Coriolis force work synergistically to improve the crushing speed. In particular, the crushing power by high speed rotation is outstanding, for example, throwing in silica sand of several millimeters size,
Fine powder with an average particle size of several microns can be obtained by operating for only a few minutes. It is typical to remove only the mill pot 4a when the pulverization is completed and collect the fine powder in the mill pot.

On the other hand, this batch type planetary ball mill has already been proved and actually used in a new way of use beyond the function as a crusher, not only for the purpose of merely pulverizing. Due to its structure, this batch type planetary ball mill is capable of high-speed rotation that cannot be achieved by other pulverizers. For example, an acceleration exceeding 30 times the gravitational acceleration G is added to the mill pot, and two or more types stored in the mill pot are used. A method called mechanical alloying has been realized, in which different alloy components are obtained by causing alloying action without melting between powders. For example, Mg and Ni, La and Ni, and Misch metal and Ni, etc. are mixed into a mill pot of a batch type planetary ball mill to store each metal powder that becomes a hydrogen storage alloy.
By applying 30 G or more in a non-oxidizing atmosphere, it has succeeded in obtaining a high-purity alloy without melting in a high-frequency induction furnace or an arc type melting furnace as in the past. In this way, mechanical aing is a new technology that is expected to develop rapidly in the future, but it is not limited to hydrogen storage alloys, but it is currently in the spotlight as a special powder processing method involving various chemical reactions. is there.

[0004]

The feature of the batch type planetary ball mill is that a relatively small amount of powder and granules are charged into a mill pot together with a grinding medium, and the centrifugal force and Coriolis force due to the above-mentioned revolution and rotation motions. With the synergistic centrifugal effect of, powder particles can be easily crushed and processed in a short time. The equivalent centrifugal acceleration due to the synergistic centrifugal effect of the planetary ball mill shown in FIG. 3 reaches several tens of times (tens of G) of the gravitational acceleration on the earth (1 G), and the equivalent centrifugal acceleration of the conventional rolling ball mill. It can be understood that a very large load is applied by observing that the value is only 1 G, and the equivalent centrifugal acceleration of the vibrating ball mill remains at about 10 G. For this reason, it is inevitable that a considerable amount of heat is generated around an axis that mechanically rotates at a high speed, like other mechanical devices. This can be seen as a very desirable factor and, on the contrary, an undesirable factor in the operation of the device.

The desirable case is when a batch type planetary ball mill is intended for powder treatment accompanied by a chemical reaction such as mechanical alloying. Generally, the higher the ambient temperature is, the higher the ambient temperature is for each molecule. Is effective in accelerating the reaction, and under the same conditions, the efficiency per hour is generally increased. In that respect, the heat generation phenomenon of the batch type planetary ball mill can be said to be convenient, but this amount of heat generation is not sufficient for promoting the reaction, and it cannot be said that it is very effective for improving the reaction efficiency without more aggressive heating. In many cases. In addition, if the temperature factor in the mill pot during winter and summer changes due to the natural temperature of the atmosphere and the reaction conditions change, unless special attention is paid to the thermal factors that affect the chemical reaction during operation of the batch type planetary ball mill. Even if all other conditions are met, there is a risk of quality variations in the resulting product, and it is unavoidable that it is inappropriate as a control for high-grade materials.

[0006] In an undesired case, when a batch type planetary ball mill is used for fine pulverization, an unexpected chemical reaction occurs due to a high temperature in the mill pot mainly due to an exothermic effect mainly around an axis. , Refers to a state in which a powder with a chemical composition different from the purpose is produced. Naturally, when the temperature inside the mill pot rises and two or more kinds of powders are subjected to the strong synergistic effect of centrifugal force and Coriolis force in a state where they easily react, the activated molecular motion causes an unexpected quality fluctuation. There is a strong possibility of causing this.

In order to solve the above-mentioned problems, it is an object of the present invention to add a function of controlling a mill pot to a desired temperature to a batch type planetary ball mill in a severe motion state.

[0008]

In the batch type planetary ball mill according to the present invention, a plurality of mill pots 4 that revolve upon the rotation of the revolution shaft 21 are evenly arranged around the revolution shaft 21. In a batch type planetary ball mill that rotates about its own rotation axis 41 and efficiently treats the powder and granules sealed in the mill pot 4 together with the medium, the mill pot 4 in an adiabatic state is directly or thermally cooled. The above problem was solved by providing the temperature control mechanism 5 for controlling the temperature to a desired temperature via the medium.

More specifically, in the batch type planetary ball mill, a horizontal disk-shaped mill body 1, a revolution shaft 21 fixed vertically to the center of the mill body 1, and the mill body 1 on the revolution shaft 2 are provided.
1. A mill casing 3 is rotatably fitted into a vertical through hole 15 that is evenly distributed with respect to 1, and a mill pot 4 is removably fitted into the mill casing 3.
A temperature control chamber 53 is formed by combining a fixed heat insulating cylinder 51 that penetrates a large number of vent holes 31 into the mill casing 3 and surrounds the upper and lateral sides of the revolution range of the mill casing 3 and a bottom plate 52 that revolves together with the mill casing 4. It is preferable that the fixed heat insulating cylinder 51 be formed through the heat-insulating cylinder 51 through the supply hole 54 and the discharge hole 55 for the heat-refrigerant and connected to the source of the heat-refrigerant. Further, in this case, the rotation shaft 41 supporting the mill casing 3
Is bored in the axial direction to form a hollow portion 42, and the hollow portion 42
It is an excellent embodiment to provide a gap in the path that communicates with the temperature control chamber 53 in the negative pressure state.

On the other hand, in order to implement the direct heating method without using a heat medium, the revolving shaft 21 is bored in the axial direction to form the hollow portion 22, and the power transmission line 56 housed inside the hollow portion 22.
While revolving from one end 57, it receives power from an external power source 59,
The mill pot 4 rotating from the other end 58 of the power transmission line 56.
It is one of the excellent examples to supply power to the heating wire 61 buried in the heat insulating layer 60 filled between the mill casing 3 and the mill casing 3.

[0011]

Since the batch type planetary ball mill with temperature control according to the present invention has the above-mentioned structure, the mill pot in an adiabatic state is heated or cooled indirectly by a hot refrigerant or directly by a heating wire or the like. Maintain the internal temperature at an optimum temperature that matches the processing purpose. When a chemical reaction is required for this purpose, the temperature is raised more than the temperature rise due to spontaneous heat to promote the reaction, and if you want to avoid quality fluctuations due to temperature rise, cool the mill pot from the surroundings. As a result, the action of inhibiting the progress of the reaction occurs.
In the case of indirect heating, there is a concern that the temperature will rise due to spontaneous heat generation such as in the orbiting and rotating bearing portions, which may adversely affect the members. Therefore, it is desirable to simultaneously perform the cooling action for these portions. In addition, in the case of heating by a direct heating wire, etc., such consideration is not necessary because only the local heating of the mill pot is limited, but it is necessary to constantly send electric current to the periphery of the orbiting mill pot. So it needs a special configuration for that. Both will be described in detail in the following examples.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a vertical type batch type planetary ball mill in which the revolution axis is arranged vertically is exemplified, but there is also a horizontal type in which the revolution axis rotates horizontally in the batch type planetary ball mill. But,
It is needless to say that the structure of this figure is basically the same as that of the structure rotated at a right angle, and the idea of the present invention can be implemented in any case. In FIG. 1, the revolution shaft 21 is vertically supported by the bearing stand 11 and the bearings 12 and 13, and is directly connected to the motor 23 to rotate together with the motor shaft. The disk-shaped mill body 1 is fixed to the revolution shaft 21 via a key and horizontally revolves as the revolution shaft rotates. In the mill body 1, the circumference of the revolution shaft 21 is evenly divided to equip four through holes 15 radially at equal distances, and a cylindrical mill casing 3 is rotatably fitted into the holes through a bearing 32. is doing. The planetary gears 24 attached to the lower ends of the respective mill casings mesh with the sun gears 25 that are engaged and fixed to the bearing stand 11 on the outside of the revolution shaft on the same axis as the revolution shaft 21. The mill pot 4 is fitted into the hollow portion of the cylindrical mill casing 3 and rotated integrally with the mill casing which is locked with a pin. As a result,
The mill pot 4 revolves together with the revolution shaft in the mill casing, while receiving a relative rotational force of the planetary gear that meshes with the fixed sun gear, and rotates together with the mill casing.

As the temperature control mechanism 5 in this embodiment, a temperature control chamber 53 is formed by a fixed heat insulating cylinder 51 made of a heat insulating material surrounding the upper surface and the side surface of the mill casing 3 and a bottom plate 52 which is a lower portion thereof. The fixed heat insulating cylinder 51 has a fixed structure that surrounds the entire space of the revolution range of the mill casing, and the bottom plate 52 rotates around the revolution axis together with the mill body. A gap T is formed between the fixed heat insulating cylinder 51 and the bottom plate 52.
1 is provided to enable relative movement, but a labyrinth seal (not shown) in which various shapes are combined is attached to this cavity to prevent entry from the atmosphere into the temperature control chamber 53, It prevents the decrease of thermal efficiency. The hot air generator 62 is placed outside the machine and is connected to the supply hole 54 provided on the side surface of the fixed heat insulating cylinder 51 to supply the air heated to a desired temperature into the temperature control chamber 53. Since the mill casing 3 has a large number of ventilation holes 31 penetrating its side wall, hot air enters through the ventilation holes to maintain the mill pot 4 at a required temperature. The hot air is then discharged to the outside of the temperature control chamber 53 through the discharge hole 55, but a configuration in which the hot air is returned to the hot air generation device 62 and reused is advantageous in terms of thermal efficiency. If a discharge fan (not shown) is provided near the discharge hole 55, it is effective for sucking and discharging the hot air, and at this time, if the internal pressure of the temperature control chamber 53 is set to a negative pressure, the air flow proceeds smoothly. There are advantages. Of course, when a refrigerant is used, a cold air generator such as a refrigerator will be applied instead of the hot air generator.

In the case of heating the mill pot, heat propagates to the drive mechanism 2 via the mill casing and the rotating shaft,
There is often the possibility of adding even more severe factors to bearings operating under severe conditions. For this reason, it is desirable to prevent these heat conductions, and the figure shows an example in which this measure is taken. The axis of the rotating shaft 41 is hollowed out to form a hollow portion 42, which passes through a communication hole 43 penetrating the rotating shaft and a gap T2 provided between the bottom plate 52 and the outer peripheral surface of the mill casing 3. And communicates with the temperature control chamber 53. If such a configuration is adopted, an action of generating a cool airflow in which the outside air is sucked into the temperature control chamber 53 from the hollow portion inside the rotation shaft is produced, and the propagation of heat is offset to increase the temperature of the bearing of the drive unit. Can be prevented.

FIG. 2 shows another embodiment of the present invention. In this case, a direct heating method using the heating wire 61 is used. Revolution axis 21
Is bored in the axial direction to form the hollow portion 22, and the power transmission line 56 is housed inside the hollow portion 22. The two brushes 63 are fitted into the brush receiver 16 provided upright on the mill body 1, and the brushes are axially urged by springs 64 from the outside, and the surface of the slip ring 65 provided on the outer peripheral surface of the revolution shaft 21. Press up. Hollow part 2 from slip ring 65
2 is connected to one end 57 of the power transmission line 56, the current received from the external power source 59 is the other end 5 of the power transmission line 56.
Power is supplied to the heating wire 61 embedded in the heat insulating layer 60 via the spring 66, the brush 67, and the slip ring 68 on the outer peripheral surface of the mill casing which is rotating by way of 8. In this case, since local heating is performed, it is not necessary to consider cooling of the drive mechanism.

[0016]

As described above, according to the present invention, since the temperature in the mill pot can be freely controlled, the chemical reaction in the mill pot can be promoted, and conversely, the quality of the treated powder can be kept constant. Can be effective in
In any case, the characteristics of the batch type planetary ball mill, which is extremely peculiar to other crushers, are further expanded to develop new materials that were never expected in the past, and high-class materials that can only be obtained by extremely circumventive methods. It has also opened the way for easy manufacture of materials. In the future, it is expected that it will be in the limelight as a device indispensable for the development of highly quality-controlled functional materials and new materials.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional front view showing another embodiment of the present invention.

FIG. 3 is a front view (A) showing a conventional technique and a cross-sectional view (B) of a main part.

[Explanation of symbols]

 1 Mill main body 2 Drive mechanism 3 Mill casing 4 Mill pot 5 Temperature control mechanism 21 Revolution shaft 22 Hollow part 24 Planetary gear 25 Sun gear 31 Vent hole 41 Rotating shaft 42 Hollow part 43 Communication hole 51 Fixed heat insulating cylinder 52 Bottom plate 53 Temperature control chamber 54 Supply hole 55 Discharge hole 56 Transmission line 57 One end 58 The other end 59 Power supply 60 Heat insulation layer 61 Heating wire 62 Hot air generator

Claims (4)

[Claims] 1. A plurality of mill pots 4 revolving in response to the rotation of the revolution shaft 21 are evenly arranged around the revolution shaft 21, and each of the mill pots 4 rotates about its own rotation shaft 41. In a batch type planetary ball mill that efficiently treats powder particles that have been sealed in a mill pot 4 together with a medium, a temperature control mechanism 5 that controls the mill pot 4 in an adiabatic state to a desired temperature directly or via a heat refrigerant body. Batch type planetary ball mill with temperature control, which is equipped with. 2. The mill body 1 having a horizontal disk shape and the revolution shaft 2 fixed vertically to the center of the mill body 1 according to claim 1.
1, a mill casing 3 rotatably fitted into a vertical through hole 15 formed by uniformly distributing the mill body 1 to the revolution shaft 21, and a mill pot 4 removably fitted into the mill casing 3. The mill casing 3 has a plurality of vent holes 31 penetrating therethrough, and a fixed heat insulating cylinder 51 that surrounds the upper and lateral sides of the revolution range of the mill casing 3 and a bottom plate 52 that revolves together with the mill casing 4 are combined to control the temperature. A batch type planetary ball mill with temperature control, characterized in that a control chamber 53 is formed, and a heat-refrigerant supply hole 54 and a heat-refrigerant supply hole 55 are penetrated through the side surface of the fixed heat insulating cylinder 51 to be connected to a heat-refrigerant generation source. 3. The rotary shaft 41 supporting the mill casing 3 is bored in the axial direction to form a hollow portion 42, and the hollow portion 42 and the temperature control chamber 53 in a negative pressure state communicate with each other. A batch type planetary ball mill with temperature control, characterized by having a gap in the path. 4. The external power supply 5 according to claim 1, wherein the revolution shaft 21 is axially bored to form a hollow portion 22, and the power transmission line 56 accommodated in the hollow portion 22 revolves from one end 57 of the power transmission line 56.
9. A batch with temperature control, characterized in that power is received from the power transmission line 9 and power is supplied from the other end 58 of the power transmission line 56 to the heating wire 61 embedded in the heat insulation layer 60 filled between the rotating mill pot 4 and the mill casing 3. Type planetary ball mill.