JP2010101554A - Crucible for melting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crucible for melting capable of favorably filling a thermally conductive filler in a gap between a crucible body and a heat insulator. <P>SOLUTION: The crucible 30 for melting is equipped with the crucible body 32, a heater wire 40 provided around the crucible body 32, the heat insulator 34 disposed with the gap 35 of a predetermined interval on an outer wall surface of the crucible body 32, and the thermally conductive filler 36 filled in the gap 35. The heater wire 40 is provided so as to zigzag such that bent parts 40b are positioned in a vertical direction of the crucible body 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a melting crucible in which a metal is dissolved by heating the inside of a crucible using a heater wire.

When melting a metal, such as when casting a casting, it is common to use a melting crucible.
The melting crucible includes a crucible body formed of graphite or the like, a heater wire wound around the outer peripheral surface of the crucible body, and a heat insulating material disposed around the crucible body.
When the melting crucible is heated, the melting crucible is heated by passing a current through a heater wire provided on the outer peripheral surface of the crucible body (see, for example, Patent Document 1).

FIG. 4 shows a side view of a conventional melting crucible, and FIG. 5 shows a plan view of the conventional melting crucible.
A heater wire 12 is wound around the outer periphery of the conventional melting crucible 10 in a coil shape along the circumference of the crucible body 11.

  In the melting crucible 10, after the heater wire 12 is wound around the outer peripheral surface, the heat insulating material 14 is disposed around the heater wire 12. The gap 13 between the heat insulating material 14 and the crucible body 11 is filled with a heat conductive filler 16 having good heat conductivity such as alumina fine particles and magnesia fine particles. By filling the heat conductive filler 16 as described above, the heat of the heater wire 12 is conducted to the entire melting crucible 10 and the melting crucible 10 is efficiently heated.

JP 2006-38436 A

  In a melting crucible in which a heater wire is wound in a coil shape as in the prior art, as shown in FIG. 6, the heater wire appears substantially in the horizontal direction. Therefore, even if it tries to pour the heat conductive filler from the upper part of the gap between the crucible body and the heat insulating material, the heater wire is not obstructed and the heat conductive filler does not fall downward, and the heat conductive filler is filled. There are issues that can be difficult.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and the object is to provide a melting crucible that can satisfactorily fill the gap between the crucible body and the heat insulating material with a heat conductive filler. Is to provide.

In order to achieve the above object, the present invention comprises the following arrangement.
That is, according to the melting crucible of the present invention, the crucible body, the heater wire provided around the crucible body, the heat insulating material arranged with a predetermined gap from the outer wall surface of the crucible body, and the gap In the melting crucible provided with a thermally conductive filler filled therein, the heater wire is provided in a zigzag shape such that a bent portion is positioned in the vertical direction of the crucible body.
By adopting this configuration, it is possible to reduce the portion where the heater wire appears in the horizontal direction on the outer peripheral surface of the crucible body. For this reason, even if it is a case where the clearance gap between the outer peripheral surface of a crucible main body and a heat insulating material is narrow, a heater wire does not become obstructive and can be filled with a heat conductive filler satisfactorily.

Further, the crucible body may be formed with a concave portion into which the heater wire can be fitted in a zigzag shape such that the bent portion of the heater wire is positioned in the vertical direction of the crucible body.
According to this configuration, the heater wire can be maintained in a zigzag shape, and the heater wire can be brought into direct contact with the crucible body, so that the heating efficiency can be increased.

  According to the melting crucible according to the present invention, the thermally conductive filler can be easily filled, which contributes to shortening of the manufacturing time and can be provided at a low cost.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows the entire structure of the melting crucible, and FIG. 2 shows the crucible body and the heater wire constituting the melting crucible.
The melting crucible 30 of the present embodiment is for the purpose of melting metal, and a heater wire 40 is provided around a crucible main body 32 made of a material such as graphite, and the crucible main body 32 is heated by the heater wire 40. Is to heat. In the center of the crucible body 32, a storage recess 33 for storing the metal to be melted is formed.

On the outside of the crucible body 32, a heat insulating material 34 is disposed with a gap 35 at a predetermined interval from the outer peripheral surface of the crucible body 32.
The gap 35 is filled with fine particles having good thermal conductivity and insulating properties as the thermal conductive filler 36. Examples of the thermally conductive filler 36 include alumina fine particles and magnesia fine particles. By filling such a heat conductive filler 36, the heat generated by the heater wire 40 can be conducted to the entire crucible body 32. Moreover, the crucible body 32 and the heat insulating material 34 are fixed by filling the gap 35 between the crucible main body 32 and the heat insulating material 34 with the heat conductive filler 36.

  In addition, the heater wire 40 in this embodiment is directly attached to the crucible body 32 by being accommodated in a recess (not shown) formed on the outer peripheral surface of the crucible body 32. Thus, the heater wire 40 can efficiently dissolve the metal by directly heating the crucible body 32.

  The heater wire 40 is arranged such that one long heater wire 40 is folded in a zigzag manner so that the longitudinal portion is not positioned in the horizontal direction on the outer peripheral surface of the crucible body 32. The zigzag folded portion is located on the up-down direction side of the crucible body 32. In other words, the heater wire 40 includes a plurality of longitudinal portions 40 a that extend straight along the vertical direction along the circumference of the crucible body 32. At both upper and lower end portions of the longitudinal portion 40a, a bent portion 40b that is a portion connected to the adjacent longitudinal portion 40a is provided. The bending part 40b is performed so that the upper connection and the lower connection are alternated between the adjacent long parts 40a.

Thus, since the heater wire 40 is formed in a zigzag shape so that the bent portion 40b is positioned above or below, the heat conductive filler 36 can be easily filled.
That is, when the melting crucible 30 is viewed from above, the portion of the heater wire 40 that extends in the horizontal direction is extremely small, and even if the heat conductive filler 36 is poured into the gap 35, the heater wire 40 does not get in the way. Without the heat conductive filler 36 falling.

A power supply device 42 is connected to the end portions 43 a and 43 b of the heater wire 40 so that a high-frequency current generated by the power supply device 42 flows through the heater wire 40.
The internal configuration of the power supply device 42 is shown in FIG.
The power supply device 42 receives commercial three-phase alternating current (which may be 200 V or 100 V) and generates a predetermined high-frequency current by the high-frequency inverter 44. The high frequency current generated by the high frequency inverter 44 is input to the primary side of the high frequency transformer 46. The high frequency transformer 46 supplies the input high frequency current to the heater wire 40 connected to the secondary side. At this time, the input side of the power source and the heater wire 40 are insulated from each other by the high-frequency transformer 46, so that the risk of leakage can be eliminated.

  The high frequency inverter 44 can convert the frequency of the output current by, for example, PWM control. The PWM control can be controlled by a temperature regulator 48 connected to a temperature sensor 47 provided in the crucible body 32.

  In the above-described embodiment, the bent portion 40b is illustrated as having an arc shape or a curved shape. However, the bent portion 40b may have a shape bent linearly.

Another form of the heater wire in a folded shape will be described.
As another form, the lengths of the longitudinal portions 40a of the heater wires 40 with respect to the vertical direction of the crucible body 32 may be arranged so as to be alternately different. That is, the positions of the bent portions in the vertical direction of the zigzag fold are different from each other. For example, the positions of the upper end portions of the longitudinal portion 40a are all the same, and the positions (vertical heights) of the bent portions 40b connecting the adjacent lower end portions of the longitudinal portion 40a are made different between adjacent ones. Thus, it can be employed when the lower end of the crucible body 32 is narrowed.
As described above, as long as the position of the folding portion of the spell fold is in the vertical direction, the length of each longitudinal portion may be set to any length according to the shape of the crucible body.

  While the present invention has been described above with reference to a preferred embodiment, the present invention is not limited to this embodiment, and it is needless to say that many modifications can be made without departing from the spirit of the invention. .

It is explanatory drawing which shows the whole structure of the melting crucible of this invention. It is a block diagram which shows the structure of a crucible main body. It is a block diagram explaining the structure of a power supply device. It is explanatory drawing which shows the whole structure of the conventional melting crucible. It is a top view of the conventional melting crucible. It is explanatory drawing which shows a mode that a heat conductive filler is filled.

Explanation of symbols

30 melting crucible 32 crucible body 33 housing recess 34 heat insulating material 35 gap 36 heat conductive filler 40 heater wire 40a longitudinal portion 40b bent portion 42 power supply device 43a, 43b end of heater wire 44 high frequency inverter 46 high frequency transformer 47 temperature sensor 48 Temperature controller

Claims (2)

Crucible body,
A heater wire provided around the crucible body,
A heat insulating material arranged with a predetermined gap between the outer wall surface of the crucible body, and
In a melting crucible provided with a thermally conductive filler filled in the gap,
The heater wire is
A melting crucible characterized in that it is provided in a zigzag manner so that the bent portion is positioned in the vertical direction of the crucible body.   2. The crucible body has a recess into which the heater wire can be fitted, and is formed in a zigzag shape so that a bent portion of the heater wire is positioned in the vertical direction of the crucible body. A melting crucible.

Images