JP3816970B2 - Electrostatic floating furnace - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an electrostatic levitation furnace.
[0002]
[Prior art]
When materials are melted using a furnace in a zero-gravity environment or microgravity environment such as in space or in a drop tower experiment, the melted materials do not cause phenomena such as convection or precipitation, so the specific gravity differs greatly. There is an advantage that a homogeneous alloy or a mixture can be made even from the material, or since there is no influence of gravity, a true sphere can be easily made.
[0003]
However, when the material is melted, if the material is in contact with a furnace or the like, impurities may enter from the contact portion of the furnace or the like, which may impair the quality of the product. Needs to melt the material in a non-contact state.
[0004]
Therefore, an electrostatic levitation furnace has been developed to melt the material in a floating state.
[0005]
3 and 4 show a conventional electrostatic levitation furnace.
[0006]
On the central axis 2 of a transparent cylindrical electrostatic levitation furnace body 1 made of quartz glass or the like, a pair of spherical electrodes 4 and 5 are arranged with a space between each other and the spherical portions 3 facing each other. A plurality of sets of grid-like electrodes 7 to 10 parallel to the central axis 2 are arranged on the same circumference 6 centering on the central axis 2 inside the electrostatic levitation furnace body 1 at equal intervals in the circumferential direction. (4 sets are arranged in the figure, and each of the grid electrodes 7 to 10 is formed in an arc shape).
[0007]
A DC power source 11 is connected between the spherical electrodes 4 and 5, and electrodes (7, 9, 8, 10) located at a target position with respect to the central axis 2 are between the grid electrodes 7 to 10. The AC power supply 12 is connected so as to have the same polarity and the adjacent electrodes (7, 8, 8, 9, 9, 10, and 10, 7) have opposite polarities.
[0008]
In the figure, 13 is a material, 14 is a heat source such as a heat ray lamp attached to the electrostatic floating furnace main body 1, 15 is a reflecting mirror for reflecting / condensing the heat ray 16 emitted from the heat source 14, and 17 is made of an insulating material. A material suction pipe, 18 is a vacuum source such as a vacuum pump or a vacuum tank connected to the material suction pipe 17, 19 is a valve provided in the middle of the material suction pipe 17, and 20 and 21 are electrode support members.
[0009]
Then, by the AC power supply 12, the opposing electrodes (7, 9, and 8, 10) have the same polarity, and the adjacent electrodes (7, 8, 8, 9, 9, 10, and 10, 7) have opposite polarities. Then, an AC voltage is applied between the grid electrodes 7 to 10, and a DC voltage of the same polarity is applied between the spherical electrodes 4 and 5 by the DC power supply 11.
[0010]
In this state, the vacuum source 18 such as a vacuum pump or a vacuum tank is operated to suck the material 13 to the tip of the material suction pipe 17 and between the grid electrodes 7 to 10 of the electrostatic floating furnace body 1 (in the figure). The material 13 is transported to the center position of the electrostatic levitation furnace body 1 through the grid electrodes 8 and 9), and corona discharge is caused on the way, so that the material 13 is opposite to the spherical electrodes 4 and 5. Then, the suction is stopped by closing the valve 19 or the like, and the material suction pipe 17 is connected to the discharge side of the vacuum pump and the valve 19 is temporarily opened to blow the material 13. Is separated from the material suction pipe 17.
[0011]
Then, the separated material 13 is moved toward the central axis 2 by a repulsive force generated between the grid electrodes 7 to 10 whose polarities are alternately changed by applying an AC voltage.
[0012]
The material 13 is stopped at an arbitrary position on the central axis 2 by a repulsive force generated between the pair of spherical electrodes 4 and 5 to which a DC voltage having a polarity opposite to that of the material 13 is applied.
[0013]
As described above, the arrangement of the electrodes 4, 5 and 7 to 10 is devised so that the AC voltage and the DC voltage are separately applied and the floating position of the material 13 can be controlled easily and stably. become able to.
[0014]
When the floating position of the material 13 is stabilized in this way, the heat source 16 such as a heat ray lamp is used to directly irradiate the material 13 with the heat ray 16 or reflect the heat ray 16 with the reflecting mirror 15. The stopped material 13 is heated and melted.
[0015]
When the material 13 is melted and the whole is in a homogeneous state, the irradiation of the heat ray 16 from the heat source 14 is stopped and the material 13 is solidified to obtain a desired product.
[0016]
When the product is thus obtained, the material suction pipe 17 is inserted into the position between the grid electrodes 7 to 10 of the electrostatic floating furnace body 1 (in the figure, the position is between the grid electrodes 8 and 9), A vacuum source 18 such as a vacuum pump or a vacuum tank is operated to open a valve 19 so that the product is sucked into the tip of the material suction pipe 17 and taken out of the electrostatic floating furnace body 1.
[0017]
[Problems to be solved by the invention]
However, the electrostatic levitation furnace has the following problems.
[0018]
That is, when the material 13 is positioned at the center of the electrostatic levitation furnace body 1, the material 13 is sucked and inserted into the tip of the material suction pipe 17, the suction is stopped, and the material suction pipe 17 is blown lightly. However, in this case, the material 13 may be blown off, and it is difficult to position the material 13 at the center of the electrostatic floating furnace body 1.
[0019]
As another material insertion means, the material 13 may be grasped with a manipulator or the like and inserted into the center of the electrostatic levitation furnace body 1. In this case, the manipulator is opened and the material 13 is removed. When separated, the manipulator and the material 13 cause electrostatic repulsion, and the material 13 will fly away. Similarly, it is difficult to position the material 13 at the center of the electrostatic floating furnace body 1. is there.
[0020]
In view of the above circumstances, an object of the present invention is to provide an electrostatic levitation furnace in which a material can be easily positioned at the center of an electrostatic levitation furnace body.
[0021]
[Means for Solving the Problems]
In the present invention, a through-hole extending in the central axis direction is formed in a spherical electrode arranged on the central axis of the electrostatic floating furnace main body, and a manipulator is inserted into the through-hole from the outside of the electrostatic floating furnace main body. The material is held at the tip of the manipulator via a metal thin wire member that can be easily blown by a small current, and a fusing circuit equipped with a fusing power source is connected to the thin wire member. In particular, the present invention relates to an electrostatic levitation furnace characterized in that an extraction device that can be extracted outward is provided.
[0022]
[Action]
The operation of the present invention is as follows.
[0023]
A through-hole extending in the direction of the central axis is formed in the spherical electrode arranged on the central axis of the electrostatic levitation furnace body, and a manipulator is inserted into the through-hole from the outside of the electrostatic levitation furnace body so as to be freely accessible. The material is held through a metal thin wire member attached to the tip of the metal and easily meltable by a slight current.
[0024]
Then, by applying an electric current to the fine wire member by the power source for fusing, the fine wire member is burned out, and when it is burned out from the fine wire member, the manipulator is instantaneously pulled out by the extraction device, thereby charging the material. This prevents the manipulator from causing electrostatic repulsion and flying the material.
[0025]
As a result, the material can be accurately positioned at the center of the electrostatic levitation furnace body.
[0026]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0027]
FIG. 1 shows a first embodiment of the present invention.
[0028]
Since the basic structure of the electrostatic levitation furnace itself is the same as that shown in FIGS. 3 and 4, these drawings are referred to as necessary.
[0029]
In the present invention, for example, in the drawing, a through-hole 22 that penetrates the upper spherical electrode 5 and its electrode support member 20 in the direction of the central axis 2 is formed, and a manipulator 23 is inserted and disposed in the through-hole 22.
[0030]
The manipulator 23 includes a manipulator main body 24 made of an insulating cylinder that can freely enter and exit through the through-hole 22, and a tip of the manipulator 23 taken out through the manipulator main body 24 to the inside of the electrostatic floating furnace main body 1. A thick wire member 25 constituting a pair and a metal thin wire member 26 connected and coupled between the ends of the thick wire member 25 and easily meltable by a slight current are configured.
[0031]
The fine wire member 26 is configured to hold the material 13 by being passed through a through hole formed in the material 13. The thin wire member 26 can also be a part of the thermocouple.
[0032]
A material charging circuit 29 is configured by connecting a thermocouple measuring unit 27 and a charging power source 28 to the rear end of the thick wire member 25 constituting the thermocouple.
[0033]
Then, a fusing circuit 43 including a fusing power supply 30 and a switch 31 is connected in parallel to the material charging circuit 29.
[0034]
At this time, the thermocouple measuring unit 27 is provided with a protective circuit 32 so as not to be affected by the fusing power supply 30.
[0035]
Further, the extraction device 33 is attached to the manipulator 23.
[0036]
The extraction device 33 engages the flange 34 with a flange 34 attached to the outer periphery of the rear end of the manipulator body 24, an elastic member 35 such as a coil spring interposed in a compressed state between the flange 34 and the spherical electrode 5, and the flange 34. And a trigger device 36 that can be unlocked.
[0037]
The trigger device 36 includes an electromagnetic trigger 39 including an electromagnetic coil 37 and a magnetic iron core 38, a trigger power supply 40, a switch 41, and a trigger circuit 44 including a delay circuit 42 such as a capacitor. .
[0038]
The switches 31 and 41 are interlocked.
[0039]
Next, the operation will be described.
[0040]
The process of producing the desired product by heating and melting the material 13 in the electrostatic levitation furnace and taking out the product from the electrostatic levitation furnace body 1 is the same as in FIG. 3 and FIG.
[0041]
When the material 13 is positioned at the center of the electrostatic levitation furnace body 1 prior to the melting of the material 13, in the present invention, the manipulator 23 in which the material 13 is passed through the thin wire member 26 in advance is connected to the upper spherical electrode 5 and its It is inserted from a through hole 22 formed in the electrode support member 20.
[0042]
In the drawing, the material 13 is drawn larger than the diameter of the through-hole 22, but this is for convenience of explanation.
[0043]
At this time, an elastic member 35 such as a coil spring is interposed between the flange 34 attached to the outer periphery of the rear end of the manipulator body 24 and the spherical electrode 5 in a compressed state, and the trigger device 36 is used to engage the back surface of the flange 34. Try to stop.
[0044]
In this state, the charging power supply 28 of the material charging circuit 29 applies a current to the material 13 through the thick line member 25 to charge the material 13. At this time, the thermocouple measuring unit 27 measures the charge of the material 13 so that a desired charge is given to the material 13.
[0045]
When the material 13 is charged, the switch 31 of the fusing circuit 43 is turned on, and a current is passed through the thin wire member 26 by the fusing power source 30 to heat and burn the fine wire member 26.
[0046]
If the thin wire member 26 is burned out, the material 13 and the thick wire member 25 constituting the thermocouple may cause electrostatic repulsion and the material 13 may fly away. 44, the switch 41 is turned on, and the delay circuit 42 causes a slight time delay to cause a current to be sent from the trigger power supply 40 to the electromagnetic trigger 39, thereby generating a magnetic field in the electromagnetic coil 37 and electromagnetic induction action. Then, the magnetic band iron core 38 is moved to release the locking state with respect to the flange 34.
[0047]
Then, due to the action of the elastic member 35 such as a coil spring, the manipulator 23 is instantaneously ejected outward from the upper spherical electrode 5 and the through hole 22 of the electrode support member 20 to constitute the thermocouple with the material 13. Thus, the material 13 is prevented from flying due to electrostatic repulsion with the thick line member 25.
[0048]
As described above, the material 13 can be reliably positioned at the center of the electrostatic floating furnace body 1.
[0049]
FIG. 2 shows a second embodiment of the present invention.
[0050]
In the present embodiment, a case where an air cylinder 45 with good responsiveness is used as the sampling device 33 is shown.
[0051]
In the figure, 46 is an air source for supplying working air to the air cylinder 45, and 47 is a valve provided between the air cylinder 45 and the air source 46.
[0052]
Then, after the material 13 is charged, the switch 31 of the fusing circuit 43 is turned ON, and a current is passed through the thin wire member 26 by the fusing power source 30 to heat and burn the fine wire member 26. The switch 41 is turned ON, the valve 47 is opened with a slight time delay by the delay circuit 42, the working air from the air source 46 is supplied to the rod side quality of the air cylinder 45, and the air cylinder 45 is contracted. The manipulator 23 is instantaneously ejected outward from the upper spherical electrode 5 and the through hole 22 of the electrode support member 20.
[0053]
Even if it does in this way, it will prevent that material 13 and the thick line member 25 which comprises a thermocouple raise | generate an electrostatic repulsion, and material 13 will fly away, and material 13 is made to electrostatically float furnace main body 1 reliably. Can be positioned at the center of
[0054]
Except for the above, the configuration is the same as that of the above-described embodiment, and the same actions and effects can be obtained.
[0055]
It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
[0056]
【The invention's effect】
As described above, according to the electrostatic levitation furnace of the present invention, an excellent effect that the material can be easily positioned at the center of the electrostatic levitation furnace body can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a first embodiment of the present invention.
FIG. 2 is a schematic side view of a second embodiment of the present invention.
FIG. 3 is a schematic side view of a conventional example.
4 is a schematic plan view of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electrostatic floating furnace body 2 Center axis 4 Spherical electrode 13 Material 22 Through-hole 23 Manipulator 26 Fine wire member 30 Power source 33 Fusing device 43 Fusing circuit

Claims (1)

A through-hole extending in the direction of the central axis is formed in the spherical electrode arranged on the central axis of the electrostatic levitation furnace main body, and a manipulator is inserted into the through-hole from the outside of the electrostatic levitation furnace main body so as to be freely accessible. The material is held at the tip via a metal thin wire member that can be easily melted by a small amount of current, and a fusing circuit equipped with a power source for fusing is connected to the thin wire member. An electrostatic levitation furnace provided with an extraction device that can be extracted to

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