JP2001198664A - Vacuum casting and heat treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum casting and heat treatment apparatus in which metals are melted and cast under vacuum, obtained castings are subjected to the continuous heat treatment to eliminate segregation of specified component and impurities in an alloy in the casting, the energy is free from waste, and the productivity is high. SOLUTION: The vacuum casting and heat treatment apparatus 10 comprises a pallet charging chamber 11 to feed a pallet 7 to load the casting work W into an adjacent melting and casting chamber 21 by a rotating roll 18, the melting and casting chamber 21 to cast and cool the metals into the work W and load it on the pallet 7, a heating space 43 in which the pallet 7 loading the work W from the melting and casting chamber 21 is carried by a rotating roller 48, and passed forming a row of the pallets 7 within the heating space 43 provided in a heat treatment chamber 41, and a cooling chamber 51 in which cold gaseous argon is sprayed on the work W to rapidly cool it transferred from the heat treatment chamber 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum casting heat treatment apparatus, and more particularly, to an apparatus capable of melting and casting metals under vacuum and continuously heat-treating the obtained casting. Things.

[0002]

2. Description of the Related Art Castings obtained by melting and solidifying metals, including metals and alloys, are subject to segregation of specific components of the alloy, and the components differ between the first solidified portion and the later solidified portion. The material is heat treated and homogenized. However, since the diffusion rate in the solid phase is low, a long-time heat treatment at a high temperature is required for homogenization. For example, alloys containing rare earth metals such as samarium / cobalt alloys and iron / neodymium / boron alloys are attracting attention as high-performance magnets and as materials for negative electrodes (hydrogen storage alloys) for secondary batteries. However, since obtaining a high-performance alloy requires a homogeneous crystal structure in which rare-earth metals are finely dispersed, the alloy material is melted and cast, and then the casting is effectively used to homogenize the casting. Must be heat treated.

(Conventional example) FIG. 8 shows a vacuum casting apparatus 140 disclosed in Japanese Patent Application Laid-Open No. Hei 5-237635 filed by the present applicant and a vacuum heat treatment apparatus 1 provided separately.
60 is a longitudinal sectional view of FIG. Vacuum chamber 1 of vacuum casting device 140
In the inside 41, an induction heating type melting furnace body 144 is pivotally supported by a column 142 and is tilted by a hydraulic cylinder 143. An induction heating coil 146 for heating the melting furnace 144 is supplied with power by a high-frequency cable 145. Then, the formed molten metal is tilted into the melting furnace 14.
4 is a water-cooled disk 15 rotating downward via a gutter 147
The molten metal is poured into a disk-shaped mold 155 fixed to 3 and cooled and solidified. That is, the water-cooled disk 153
Is rotated by a vertical rotation shaft 151 extending downward and outside through a vacuum seal 152 provided on the bottom wall of the vacuum chamber 141, and cooling water is supplied and discharged. The mold 155 is superimposed on the water-cooled disk 153 and fixed with bolts, and an annular mold frame 157 is detachably attached to the periphery of the mold 155.

[0004] The hydrogen storage alloy is often cast by the vacuum casting apparatus 140 described above. That is, the raw metal is put into the melting furnace 144, and the raw metal is melted by induction heating under vacuum. When the molten metal is formed, the melting furnace body 144 is tilted by the hydraulic cylinder 143, and the molten metal is discharged onto the rotating water-cooled mold 155.
The molten metal is spread over the entire surface by the rotation of the mold 155, cooled, and solidified. The casting solidified in the water-cooled mold 155 is not welded to the mold 155, and
Easily removed with. Thus, the vacuum casting apparatus 1
40 has the characteristics that the mold 155 does not need to be disassembled or cleaned, and that the casting can be easily handled.

However, as described above, in a hydrogen storage alloy which is simply cast, a specific component of the alloy is segregated.
For example, for a casting having a melting point of about 1500 ° C., about 1
A heat treatment is performed at a temperature of 000 ° C. for 8 to 12 hours to homogenize to diffuse a specific component of the alloy. For this purpose, the casting is sufficiently cooled to a temperature at which the casting is not oxidized even when it is brought into contact with the atmosphere in the vacuum casting apparatus 140, for example, 100 ° C. or lower. Are distributed to a plurality of heat treatment vessels 159, and these are distributed to a three-chamber vacuum heat treatment furnace 16.
0, and heating is performed under a vacuum at a predetermined temperature for a predetermined time. That is, in the vacuum heat treatment furnace 160, evacuation is performed in the preparation chamber 161, heating is performed by the heater 163 in the heating chamber 162, and heat treatment is performed.
5 cools the casting by circulating cool air of argon gas.

[0006]

SUMMARY OF THE INVENTION Conventional vacuum casting apparatus 1
The method for diffusing impurities in metals and specific components in alloys by using the 40 and the vacuum heat treatment apparatus 160 to homogenize has the following problems. a. After being once cooled to a temperature of about 100 ° C. by the vacuum casting apparatus 140 and taken out into the atmosphere, the inside of the vacuum heat treatment apparatus 160 is evacuated and heated again to 1000 ° C., and energy loss is large. For example, if the molten metal can be cooled to 900 ° C. to form a casting, and then heat-treated without being brought into contact with the atmosphere, electric energy for heating corresponding to a temperature difference of 800 ° C. can be saved. That is, the production amount of the hydrogen storage alloy is set at 1000 tons / year = 10
⁶ kg / year, with a specific heat of 0.12 kcal / kg
In the case of ° C., the amount of heat that can be saved is as follows. 10 ⁶ kg / year × 0.12 kcal / kg · ° C. × (90
0-100) ° C. = 96 × 10 ⁶ kcal / year b. In a vacuum casting apparatus 140, the casting is heated to 100 ° C.
It takes time to cool to a temperature on the order of magnitude, and this cooling time greatly reduces productivity. Incidentally, the approximate time distribution in the vacuum casting apparatus 140 in which the casting amount per batch is 600 kg is as shown in Table 1.

[Table 1] Without this cooling, 2.5 cycles per cycle of melting and casting
hr can be shortened. c. At present, the removal of the casting from the mold 155 of the vacuum casting device 140, the pulverization, the charging into the heat treatment container 159, and the charging into the vacuum heat treatment device 160 are all manually performed, and the need for automation is required. . d. Alloy components having a high vapor pressure tend to evaporate from the molten metal in the crucible, and there is also a problem that the composition ratio of the alloy tends to differ from the set value.

The present invention has been made in view of the above-mentioned problems, and it is possible to produce a homogeneous casting by melting and casting metals under vacuum and continuously heat-treating the obtained casting. An object of the present invention is to provide a vacuum casting heat treatment apparatus that can significantly improve productivity without a large energy loss.

[0008]

Means for Solving the Problems The above-mentioned problems are solved by the structure of claim 1. To explain the solution, the vacuum casting heat treatment apparatus of claim 1 dissolves metals under vacuum. It is connected to one side of the melting and casting chamber via a partition door, and the carrier to be loaded under atmospheric pressure is vacuumed. It is connected to the other side of the melting and casting chamber via a partition door, and is connected to the other side of the melting and casting chamber via a partition door. This apparatus is composed of a heat treatment chamber for heating to a predetermined temperature for a predetermined time, and a cooling chamber connected to the downstream end of the heat treatment chamber via a partition door and for rapidly cooling the casting and sending it to the atmospheric pressure. Such a vacuum casting heat treatment apparatus,
It is possible to heat-treat the casting without contacting it with the atmosphere after casting, compared to the conventional method in which the casting is heated to a temperature of 100 ° C. or less and then heated again to be heat-treated. Thus, the time required for cooling and the waste of energy for once cooling and reheating the casting can be eliminated, thereby reducing the manufacturing cost of the casting and greatly improving the productivity.

[0009] In the vacuum casting heat treatment apparatus according to claim 1, the metal is induction-heated and melted in a crucible in a melting and casting chamber, and the metal is discharged to a cooling device to form a casting, and cooling is performed. Is a device in which a casting is separated from equipment for use and loaded on a carrier. In such a vacuum casting heat treatment apparatus, a metal is uniformly melted by convection of a molten metal in a crucible, and a casting obtained by cooling the molten metal with a cooling device is loaded on a carrier and sent to a heat treatment chamber. Make it possible. The vacuum casting heat treatment apparatus according to claim 3 according to claim 1 can add a component having a high vapor pressure to the molten casting chamber in a time-division manner or add it later into the molten metal of the crucible, and can seal the crucible. This is a device provided with a mechanism. Such a vacuum casting heat treatment apparatus can correct variations in the alloy composition of the molten metal caused by evaporation of the alloy component having a high vapor pressure when casting an alloy. The vacuum casting heat treatment apparatus according to claim 4 according to claim 1 is an apparatus provided with a cooling mold or a cooling rotating roll as a cooling device. Such a vacuum casting heat treatment apparatus forms a block-shaped casting relatively cooled slowly by a cooling mold, and forms a flake-shaped casting relatively cooled rapidly by a cooling rotating roll.

The vacuum casting heat treatment apparatus according to claim 5 is provided with a heating section surrounded by a heat insulating material or a heat reflection plate and having an entrance and exit of a door. Is a device that is heat-treated in the heating section together with the carrier. Such a vacuum casting heat treatment apparatus can heat-treat a casting under an atmosphere having a uniform temperature distribution, and suppresses energy loss during the heat treatment.
The vacuum casting heat treatment apparatus according to claim 6 which is dependent on claim 1 is:
This is an apparatus in which the starting and stopping of the transporting means of the transporting body in the heat treatment chamber is controlled such that the transporting bodies loaded with the castings are in contact with each other to form a row in the heating section. Such a vacuum casting heat treatment apparatus can shorten the entire length of the heating section. The vacuum casting heat treatment apparatus according to claim 7 is a device in which the heat treatment chamber is branched at an upstream end into a plurality of branch heat treatment chambers, and the casting is distributed and heat treated at the branch point. Such a vacuum casting heat treatment apparatus can shorten the entire length of the heat treatment chamber.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vacuum casting heat treatment apparatus of the present invention
As described above, the metal is melted and cast under vacuum, and the obtained casting is loaded on the carrier and the melting casting chamber is connected to one side of the melting casting chamber via a partition door. A carrier loading chamber that sends a carrier loaded from under atmospheric pressure to the melting and casting chamber under vacuum, and is connected to the other side of the melting and casting chamber via a partition door, and is loaded from the melting and casting chamber to the transporting body. Is connected to the downstream end of the heat treatment chamber via a partition door, and is cooled rapidly and sent out under atmospheric pressure. And a cooling chamber. That is, FIG. 1 is a plan view conceptually showing a vacuum casting heat treatment apparatus 1 according to the present invention, in which, from the left, a carrier charging chamber 11, a melting casting chamber 21,
A heat treatment chamber 41 and a cooling chamber 51 are connected to each other, and partition doors 8a, 8b, 8c are provided between the heat treatment chamber 41 and the cooling chamber 51. A take-out door 9b is provided, and even though not shown, each chamber is capable of evacuating and introducing an inert gas.

The carrier loading chamber 11 is for feeding the carrier 7 under atmospheric pressure to the melting and casting chamber 21 which is usually maintained in a vacuum, and as far as this is possible, the loading of the carrier is carried out. The structure of the chamber 11 and the means for feeding the carrier are not particularly limited.

The heating for melting the raw material metals in the melting and casting chamber 21 may be any of induction heating, resistance heating, arc heating, electron beam heating, and laser beam heating. In particular, the melting furnace 22 shown in FIG. The method of inductively heating the crucible in the crucible is a preferable heating method in that the melt of the metal to be formed is convected in the crucible and easily melted uniformly. In addition, when melting the alloy, alloy components having a high vapor pressure are likely to evaporate, and the composition ratio of the molten metal is liable to fluctuate. Also, it is desirable to provide a mechanism capable of sealing the crucible after the addition of the component.

Further, in order to solidify the molten metal to obtain a casting, in order to increase the solidifying speed of the molten metal, the molten metal is poured into a cooling mold (for example, a water-cooled mold), and a block-shaped casting W shown in FIG. And a method in which a molten metal is spread on the surface of a rotating cooling roll (for example, a water-cooled roll) to obtain a flaky casting having a thickness of 1 mm or less. In the case of a water-cooled mold, relatively slow cooling produces relatively coarse crystal grains, and in the case of a water-cooled rotating roll, relatively rapid cooling produces relatively fine crystal grains. Things are obtained. Of course, cooling may be performed by a method other than the above, and the method of cooling the molten metal is not limited. Then, the casting W is loaded onto the carrier 7 intermittently fed from the adjacent carrier loading chamber 11 in synchronization with the casting W formed at a fixed time interval, and the adjacent heat treatment chamber 41 is loaded. Is moved to The loading and transfer of the casting W at this time may be performed by any means.

In order to perform the heat treatment in an atmosphere having a uniform temperature distribution and to effectively use the heating energy, the inside of the heat treatment chamber 41 is provided with an entrance having a door surrounded by a heat insulating material or a heat reflection plate. It is desirable to provide a heated compartment and heat-treat in the heated compartment. The transfer of the transfer body 7 loaded with the casting W in the heat treatment chamber 41 may be performed by a rotating roller or a chain belt.
Any other means may be used. Above all,
The transport by the rotating roller is mechanically simple and preferable, but since the heat treatment is performed in a high temperature atmosphere of about 1000 ° C., it is preferable to use a rotating roller made of a carbon / carbon composite material having excellent heat resistance and mechanical strength. .

Since a long time is required for the heat treatment, the heat treatment chamber 4
Although the length of 1 is inevitably large, the entire length of the heat treatment chamber 41 can be shortened by forming a row so that the front and back of the transfer body 7 are in contact with each other and transferring the row. Further, as conceptually shown in FIG. 2 which is a plan view similar to FIG. 1, the heat treatment chamber 41 is branched at its upstream end to provide a plurality of branch heat treatment chambers 41 ′ and a cooling chamber 51 ′. Thus, the total length of the heat treatment chamber 41 can be shortened even if the casting W is evenly distributed to the respective branch heat treatment chambers 41 '. Note that the same reference numerals in FIG. 2 as those in FIG. 1 denote the same components, or the same reference numerals with ('), and a description thereof will be omitted. Needless to say, the above-described heating section may be provided in the branch heat treatment chamber 41 ′. FIG. 2 shows three rows of the branch heat treatment chambers 41 ′ and the cooling chambers 51 ′ arranged in parallel. However, the number of rows is not limited to three, and the rows need not be parallel.

When the heat treatment is completed, the casting W at a temperature of about 1000 ° C., if left to cool as it is, takes a long time to lower the temperature. In addition, specific components of the alloy become unevenly distributed during the temperature lowering. Since there is a problem of homogenization, the casting W is transferred from the heat treatment chamber 41 to the cooling chamber 51 and rapidly cooled. As a method of quenching, an inert gas cooled to a low temperature by a heat exchanger may be sprayed on the casting, or there may be a method of spraying liquid nitrogen or dipping in liquid nitrogen.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vacuum casting heat treatment apparatus of the present invention will be described in detail with reference to the drawings.

(Embodiment) FIG. 3 is a longitudinal sectional view of an alloy (for example, a hydrogen storage alloy) vacuum casting heat treatment apparatus 10, which is a specific embodiment of the vacuum casting heat treatment apparatus 1 shown in FIG. That is, the vacuum casting heat treatment apparatus 10 loads the pallet 7 as a carrier for transporting the casting W under atmospheric pressure in order from the left side, and loads the pallet into the adjacent melting and casting chamber 21 under vacuum. A chamber 11, a casting W obtained by melting and casting a raw material metal, and loaded on a pallet 7; a casting W loaded from the melting casting chamber 21 onto the pallet 7 for a predetermined time; It comprises a heat treatment chamber 41 for heat treatment by heating to a temperature, and a cooling chamber 51 for rapidly cooling the casting W after the heat treatment. Although not shown, each chamber is connected to a vacuum exhaust system and an introduction pipe for an argon (Ar) gas as an inert gas.

The pallet loading chamber 11 is provided with a pallet loading door 9a for loading the pallet 7 under atmospheric pressure, and is connected to the melting and casting chamber 21 via a partition door 8a. In order to send the pallet 7 into the melting and casting chamber 21 under vacuum, start and stop are controlled, and a plurality of rotating rollers 18 that rotate synchronously are arranged. As described later, the pallet 7 is intermittently fed.

FIGS. 4 and 4 are partially enlarged views of FIGS.
Referring to FIG. 5 which is a cross-sectional view taken along the line [5]-[5] in FIG. ing. A melting furnace body 22 having a crucible for inductively heating and melting the raw material metals is provided on the cylindrical body portion so as to be tiltable, and a high-frequency induction heating high-frequency cable 29 whose illustration is simplified.
Is drawn out from the melting furnace body 22 to the outside on the back side of the melting casting chamber 21. Also, on the same back side, a vacuum exhaust system 30 is provided.
Is connected. Then, in the melting furnace casting chamber 21, the raw material of the alloy is located above the melting furnace
A raw material supply device 24 for supplying the material to the crucible 2 is provided. Further, as shown in FIG. 4, an addition supply device 25 is provided together with the chute 25s, which can add the alloy component having a large vapor pressure temporally to the crucible in a time-shifted manner or can be added later. Is provided with a lid 23 capable of closing the opening of the crucible after adding an alloy component having a high vapor pressure, together with its opening / closing mechanism 23m. In addition to the above, a crucible temperature measuring mechanism 26, a sample collecting mechanism 27, a crucible removing mechanism 28, and the like are attached to the main body of the melting and casting chamber 21; Then, in the melting and casting chamber 21, the melting and casting of metals are repeated in a certain cycle under vacuum.

On the front side of the melting furnace body 22, the melting furnace body 22 is tilted and a tundish 31 into which the molten metal is poured, and a water cooling plate 3 for receiving and cooling the molten metal from the tundish 31.
2, a water-cooled mold is formed by an annular mold frame 33 movably set on the water-cooled plate 32,
The molten metal is cooled and solidified in a water-cooled mold to form a thick disk-shaped casting W. Then, as shown in FIG.
The casting frame 33 is not dropped but a casting W is provided with an opening 34 having a diameter at which the casting frame W can fall, and is pushed by a member (not shown).
At the same time, when the casting W is moved onto the opening 34, the pushing member 35 is lowered from above and pressed, whereby the casting W is separated from the mold frame 33 and dropped out of the opening 34. . The mold frame 33 remaining on the water cooling plate 32 is reused.

Below the water cooling plate 32, a plurality of the same as the rotating rollers 18 in the pallet loading chamber 11 for receiving the castings W falling at regular time intervals and transporting the pallets 7 to be loaded. Rotary rollers 38a and 38b are provided. The rotating roller 38a is attached to a stationary member (not shown), and the rotating roller 38b is attached to a movable table 36 that can move vertically and horizontally in FIG. That is, the moving table 36 is raised from the position shown in FIG. 4, and when the falling casting W is received on the pallet 7 on the rotating roller 38b, it is lowered to the original position. Returning to FIG. 3, when the partition door 8 b is opened, the moving table 36 is moved rightward to move the pallet 7 onto the rotating roller 48 of the heat treatment chamber 41.

In the heat treatment chamber 41 connected to the melting and casting chamber 21 via the partition door 8b, a plurality of rotating rollers 48 whose start and stop are suppressed from the upstream end to the downstream end thereof at a constant pitch. And intermittently transports the pallet 7 to the downstream side. Since the heat treatment is performed at a temperature of about 1000 ° C., the rotating roller 48 is made of a carbon / carbon composite material having heat resistance and high mechanical strength.
8 are used. In the heat treatment chamber 41, a heating section 43 surrounded by a heat reflection plate 42 is provided. At an upstream end and a downstream end of the heating section 43, an inlet shutter 44a and an outlet shutter 44b which are opened and closed according to the conveyance of the pallet 7 are provided. A pipe-shaped resistance heater 45 is provided along the inner wall of the heating section 43. It is arranged.

A rotary roller 58 similar to that of the pallet loading chamber 11 is provided in a cooling chamber 51 connected to the heat treatment chamber 41 through a partition door 8c. A ceiling fan 53 and a heat exchanger 54 are installed. Then, Ar gas is introduced at a predetermined pressure into the cooling chamber 51 under vacuum, circulated by the ceiling fan 53, and the heat exchanger 54 in the middle of the flow path.
Thus, the temperature is reduced and the casting W on the pallet 7 is sprayed.

The vacuum casting heat treatment apparatus 10 according to the present embodiment is configured as described above, and its operation will now be described.

Referring to FIG. 3, left pallet loading room 1
The pallet loading chamber 11 is evacuated by opening the pallet loading door 9a, loading the pallet 7 on the outside onto the rotating roller 18, and closing the loading door 9a. And
The partition door 8a is opened at the timing of the formation of the casting W in the melting and casting chamber 21, and the pallet 7 is fed onto the activated rotating roller 38a of the melting and casting chamber 21 by the activated rotating roller 18. When the pallet 7 is completely loaded into the melting and casting chamber 21, the partition door 8a is closed and the rotating roller 18 is stopped. When the pallet 7 is conveyed from the rotating roller 38a to the downstream end of the rotating roller 38b in the melting and casting chamber 21, the rotating rollers 38a and 38b stop rotating, and the pallet 7 is moved below the opening 34 of the water cooling plate 32. Stopped at Next, the moving table 36 is raised, and when the pallet 7 reaches immediately below the opening 34, the lifting is stopped, and the pallet 7 is in a standby state for receiving the casting W falling from the opening 34.

On the other hand, in the melting furnace body 22 of the melting casting chamber 21, the raw metal supplied into the crucible from the upper raw material feeder 24 is induction-heated to a temperature of about 1500 ° C. to perform melting and degassing. After the alloy component having a high vapor pressure is supplied to the obtained molten metal from the addition / supply device 25 via the chute 25s into the crucible and the composition ratio of the alloy is adjusted, the lid 23 is closed by the opening / closing mechanism 23m. When a uniform molten metal is obtained, the lid 23 is opened, and the melting furnace body 22 is tilted as shown by a dashed line in FIG.
The hot water is poured into the mold 1 and poured from the tundish 31 into an annular mold frame 33 set on a water cooling plate 32, cooled and solidified to form a thick disk-shaped casting W. The melting amount per melting in the melting furnace body 22 is 100 to 150 kg.
, An example of the required time from melting to casting is approximately 40 to 45 minutes. That is, compared to the conventional example,
The same productivity can be obtained by reducing the casting weight per operation and shortening the melting / casting cycle.

Next, the casting W is separated from the water cooling plate 32. FIG. 6 shows the steps of separating the casting W from the water-cooled plate 32. FIG. 6A shows a state in which the molten metal is poured into a mold frame 33 set on the water-cooled plate 32 and cooled and solidified. 6B shows a state in which the casting W is moved downstream together with the casting frame 33 and reaches a position above the opening 34 and stopped when the casting flask 33 is pushed by a member (not shown). At this time, the casting W is separated without being welded to the water cooling plate 32 and without staining the surface. FIG. 6C shows a state in which the pushing member 35 is lowered from above with respect to the casting W, and FIG.
Is pressed by the pushing member 35 so that the casting W is
3 shows a state in which it is separated from the opening 34 and dropped out of the opening 34.

Referring to FIG. 3, when the casting W falling from the opening 34 is received and loaded on the pallet 7 on the waiting rotating roller 38b, the movable base 36 is lowered to its original height. . Subsequently, the partition door 8b is opened, and the melting and casting chamber 21 is set in the heat treatment chamber 41 in a reduced-pressure argon atmosphere.
And the rotating roller 38b is started, and the moving table 36 is moved to the downstream side.
The pallet 7 loaded with the casting W is sent out from the rotating roller 38b onto the rotating roller 48 in which the heat treatment chamber 41 is activated by inserting the casting W into the upstream end. On the other hand, when the pallet 7 separates from the rotating roller 38b, the moving table 36 is returned to the original position, and the partition door 8b is closed.

When the partition door 8b is closed, the heat treatment chamber 41
, The entrance shutter 44a of the heating section 43 is opened, and the pallet 7 loaded with the casting W is
Is fed into the heating section 43 maintained at a temperature of about 1000 ° C., and the entrance shutter 44a is closed. The pallet 7 is conveyed through the heating section 43 and is stopped in contact with the downstream end of the closed heating section of the exit shutter 44b or the rear end of the preceding pallet 7 stopped downstream. By stopping the subsequent pallet 7 in the same manner, a row of pallets 7 (for example, a row of ten pallets 7) is formed in the heating section 43. When the casting W of the pallet 7 at the forefront of the row, that is, the most downstream pallet 7 has passed a predetermined heat treatment time, the outlet shutter 44b is opened and the pallet 7 is moved from the heating section 43 to the downstream end of the heat treatment chamber 41. And the outlet shutter 44b is closed. During this time, the row of pallets 7 loaded with the castings W remaining in the heating section 43 is conveyed downstream by one pallet.

Subsequently, the partitioning door 8c is opened, and the casting W is moved from the downstream end of the heat treatment chamber 41 together with the pallet 7 to the activated rotating roller 58 of the cooling chamber 51 at a predetermined degree of vacuum.
Moved up and stopped at the cooling position. When the transfer is completed, the partition door 8c is closed, and Ar gas is introduced into the cooling chamber 51 to a predetermined pressure by an introduction pipe (not shown).
The cooling water is circulated in the cooling chamber 51 by a ceiling fan 53 driven by a motor 52, and the temperature is reduced by passing through a heat exchanger 54 in the middle of the flow path.
, The casting W is forcibly cooled. When the temperature drops to a predetermined temperature (for example, 100 ° C. or lower), the air is introduced into the cooling chamber 51, the casting removal door 9b is opened, the rotating roller 58 is activated, and the casting W is taken out together with the pallet 7. It is. Thereafter, the casting removal door 4 is closed and the cooling chamber 51 is evacuated.

The vacuum casting heat treatment apparatus 10 of the embodiment is constructed and operates as described above, but of course the present invention is not limited to this, and various modifications are possible based on the technical idea of the present invention. .

For example, in the present embodiment, the case where the pallets 7 are carried one by one into the pallet loading chamber 11 has been described, but a large number of pallets 7 are loaded in the pallet loading chamber 11 in advance, and May be taken out one by one and loaded into the melting and casting chamber 21. In the present embodiment, the cooled mold or the cooled rotating roll is water-cooled.However, a coolant other than water, such as a polyhydric alcohol, or a mixture of water and a polyhydric alcohol is used for cooling. There may be.

In this embodiment, the moving table 36 is moved up and down to receive the casting W falling from the opening 34. However, if the casting W is not damaged even if it falls, there is no problem even if the casting W is damaged. If not, it is possible to omit the elevation of the moving table 36. Further, when the pallet 7 loaded with the casting W is transferred from the melting casting chamber 21 to the heat treatment chamber 21, the moving table 36 is moved to the downstream side, and the tip thereof is moved to the heat treatment chamber 21.
Of the movable table 36 by making the interval between the rotating rollers 38b and the rotating rollers 48 on both sides of the partition door 8b equal to the pitch of the rotating rollers 38b, for example.
May be omitted.

Further, in this embodiment, when the casting W is separated from the water cooling plate 32, the casting W is pressed by the pushing member 34 descending from above, and is pulled down from the opening 34 of the water cooling plate 32. Although employed, the casting W may be separated so as to be lifted upward as shown in FIG. That is, FIG. 7A shows a state in which a casting W ′ is formed by tapping a water-cooled mold formed by surrounding the water cooling plate 62 with an annular mold frame 63, and FIG.
2 shows a state in which the casting W ′ is separated from the mold frame 63 together with the water cooling plate 62 by pushing up the bottom surface of the casting 2 by a member (not shown). Thereafter, the casting W ′ is separated from the water cooling plate 62.

In this embodiment, in the heating section 43 of the heat treatment chamber 21, the pallets 7 on which the castings W are loaded are arranged in a row in front and rear contact with each other, and are conveyed in the heating section 43 in a state close to stagnation. However, by lowering the rotation speed of only the rotation roller 48 in the heating section 43,
In the heating section 43, the pallets 7 may be conveyed at a reduced interval. Although only the case where the transfer speed of the pallet 7 is reduced during the heat treatment has been described including the embodiment, it is needless to say that the heat treatment may be performed without reducing the transfer speed of the pallet 7. Further, in this embodiment, when the pallet 7 loaded with the casting W is transferred from the downstream end of the heat treatment chamber 41 to the cooling chamber 51, the transfer is performed from the rotating roller 48 to the rotating roller 58. Inside, like the moving table 36 of the melting and casting chamber 21,
A moving table with a rotating roller 58 may be provided. In the embodiment, the pallet 7 is used to transport the thick disk-shaped casting W. However, when transporting a thin-plate casting or the like, the pallet 7 is transported using a pan or a pot as a transport body. Is done.

[0038]

The present invention is embodied in the form described above, and has the following effects.

According to the vacuum casting heat treatment apparatus of claim 1,
Since the casting can be heat-treated without being brought into contact with the atmosphere after casting, it is necessary to wait until the temperature drops to 100 ° C. or lower as before, and then compared to a method of heating again for heat treatment, The amount of electric energy used for heating is greatly reduced, and the production cost of the casting can be reduced. In addition, since the casting can be heat-treated immediately without contacting the atmosphere, and can be automatically heat-treated without manual operation, the production cost of the casting can be reduced in that aspect, and the production of the casting can be reduced. Dramatically improves sex.

According to the vacuum casting heat treatment apparatus of claim 2,
As the raw metal in the crucible is melted by induction heating,
Since the molten metal is convected and melted uniformly, and the molten metal is cooled and solidified in a short time by the cooling device, a good casting can be manufactured with high productivity. Also, since the casting is separated from the cooling device and loaded on the carrier,
The casting can be heat-treated following casting, greatly increasing productivity. According to the vacuum casting heat treatment apparatus of claim 3, when casting an alloy, alloy components having a high vapor pressure can be divided or added later with a time shift to correct variations in the alloy composition ratio. Since the opening of the crucible can be closed, it is possible to manufacture a casting having an accurate alloy composition as set.

According to the vacuum casting heat treatment apparatus of claim 4,
Since a casting having relatively coarse grains which is relatively slowly cooled by a cooled mold and a casting having relatively fine grains which are relatively quenched by a cooled rotating roll can be formed, Castings with suitable properties can be produced depending on the application. According to the vacuum casting heat treatment apparatus of claim 5, since the casting is heated in the heating section provided in the heat treatment chamber, the casting is heat-treated in an atmosphere having a uniform temperature distribution without excess or shortage to give a uniform casting, and Heating energy is used effectively.

According to the vacuum casting heat treatment apparatus of claim 6,
Heat treatment can be performed as a row in which the front and back of the pallet loaded with castings are in contact with each other in the heating section, so the overall length of the heat treatment chamber can be shortened, and heat treatment of the castings can be performed within a limited installation area. Will be possible. According to the vacuum casting heat treatment apparatus of claim 7, since the casting is distributed and heat-treated in the plurality of branch heat treatment chambers, the total length of the heat treatment chamber can be shortened and the heat treatment of the casting within a limited installation area. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a plan view conceptually showing a vacuum casting heat treatment apparatus of the present invention.

FIG. 2 is a plan view conceptually showing a modification of the device.

FIG. 3 is a longitudinal sectional view of the vacuum casting heat treatment apparatus of the embodiment.

FIG. 4 is an enlarged view of the melting casting chamber of FIG.

FIG. 5 is a sectional view taken along line [5]-[5] in FIG.

FIG. 6 shows the steps of separating the casting from the water cooling plate.

FIG. 7 is a view showing a modified example of separation of a casting.

FIG. 8 is a longitudinal sectional view showing a conventional vacuum casting apparatus and a vacuum heat treatment apparatus.

DESCRIPTION OF SYMBOLS 7 Pallet 10 Vacuum casting heat treatment apparatus 11 Pallet loading chamber 18 Rotary roller 21 Melting casting chamber 22 Melting furnace body 23 Lid 24 Raw material feeder 25 Addition feeder 31 Tundish 32 Water cooling plate 33 Mold frame 34 Opening 36 Moving table 38 Rotating roller 41 Heat treatment chamber 42 Heat reflection plate 43 Heating section 45 Resistance heater 48 Rotating roller 51 Cooling chamber 53 Ceiling fan 54 Heat exchanger W Casting

Claims (7)

[Claims] 1. A melting and casting chamber in which metals are melted and cast under vacuum, and the obtained casting is loaded on a carrier, and is connected to one side of the melting and casting chamber via a partition door. A carrier loading chamber for feeding a carrier transported under atmospheric pressure into the melting and casting chamber under vacuum, and a partition door connected to the other side of the melting and casting chamber; And a heat treatment chamber for heating a predetermined temperature for a predetermined time while conveying the casting loaded and sent out from the conveyance body, and connected to a downstream end of the heat treatment chamber via a partition door to rapidly cool the casting. And a cooling chamber for sending out under atmospheric pressure. 2. In the melting and casting chamber, metals are induction-heated and melted in a crucible, and are poured into a cooling device to form a casting. The casting is separated from the cooling device and the carrier is separated. The vacuum casting heat treatment apparatus according to claim 1, wherein the apparatus is loaded on a substrate. 3. An apparatus capable of adding an alloy component having a high vapor pressure to the molten metal of the crucible in a time-division manner or a post-addition manner, and a mechanism capable of sealing the crucible in the molten casting chamber. The vacuum casting heat treatment apparatus according to claim 1 or 2. 4. The vacuum casting heat treatment apparatus according to claim 2, wherein the cooling device is a cooling mold or a cooling rotating roll. 5. A heating section surrounded by a heat insulating material or a heat reflection plate and provided with an entrance having a door is provided inside the heat treatment chamber, and the casting is heat-treated in the heating section together with the carrier. The vacuum casting heat treatment apparatus according to claim 1. 6. The starting and stopping of the transporting means of the transporting body in the heat treatment chamber is controlled so that the transporting bodies loaded with the castings in the heating compartment form a row in contact with each other back and forth. The vacuum casting heat treatment apparatus according to claim 5. 7. The heat treatment chamber according to claim 1, wherein the heat treatment chamber is branched into a plurality of branch heat treatment chambers at an upstream end thereof, and the casting is distributed and heat-treated at the branch point. Vacuum casting heat treatment equipment.