JP5141873B2 - Vacuum induction furnace and metal material refining method using the induction furnace - Google Patents

Description

  The present invention relates to a vacuum induction furnace and a method for refining a metal material using the vacuum induction furnace.

The vacuum induction furnace has a furnace body arranged in a vacuum chamber, and is used to lower the concentration of oxygen or the like in the material by melting the material under reduced pressure (for example, Patent Document 1).
The material is charged into the furnace body of the vacuum induction furnace, for example, as follows. First, outside the vacuum chamber, the material is hung on the crane hook via a wire rope or other hanging tool. Thereafter, the material is lifted and the material is lowered into the furnace body through the opening of the vacuum chamber. Then, the worker who has entered the vacuum chamber removes the sling and the charging is completed.

After loading the material, the worker retreats out of the vacuum chamber and closes the lid to reduce the pressure in the vacuum chamber. Then, the induction coil is energized to melt the material, and the melted material is caused to flow from the upper part of the furnace body to a container such as a ladle by tilting the furnace body.
JP-A-8-143935

The conventional method of charging a material into a vacuum induction furnace is time consuming and cumbersome because the material must be slapped. Moreover, the slinging and the release thereof are not only a heavy load on the worker, but the work in the vacuum chamber requires considerable care to ensure the safety of the worker.
On the other hand, when a waste material called a return material is used as the material, the return material is bulky, so it is necessary to add the material to the furnace body after melting the previously charged material. It is difficult to redress.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vacuum induction furnace in which the material can be easily and safely charged into the furnace body, and a metal material refining using the vacuum induction furnace. It is to provide a method.

  According to the present invention, a vacuum chamber having a material inlet at the top, a lid capable of opening and closing the material inlet of the vacuum chamber, and a furnace housed in the vacuum chamber and positioned below the material inlet And tilting the furnace body in an upright state at a reference position so that the material melted in the furnace body flows out from the upper part of the furnace body, the induction coil arranged on the outer periphery of the furnace body, and the furnace body There is provided a vacuum induction furnace comprising a tilting device and a lifting device that moves the furnace body in an upright state above the reference position to position the furnace body at a material charging position ( Claim 1).

Preferably, the tilting device includes a motor for rotating the drum in the forward direction and the reverse direction, and extends from the drum to the furnace body, and the drum rotates in the forward direction and is wound around the drum. And a wire rope that causes a rotational moment to act on the furnace body (claim 2).
Preferably, the lifting device includes a lifting platform on which the furnace body is mounted, and at least one hydraulic cylinder disposed below the lifting platform for moving the lifting table in the vertical direction. ).

Preferably, the lifting device includes one hydraulic cylinder that can be expanded and contracted in the vertical direction and a guide that prevents the lifting platform from being inclined.
Preferably, each of the guides is provided with a plurality of pillars standing around the hydraulic cylinder, and extending downward from the lifting platform, and in a plan view, the guides are spaced apart from corresponding pillars. A plurality of guide rods facing each other, and a guide roller disposed between the support column and the guide rod.

  Preferably, the vacuum induction furnace further includes a control device that controls operations of a hydraulic cylinder of the lifting device and a motor of the tilting device, and the control device moves the furnace body up and down by the lifting device. The motor is operated while monitoring the tension applied to the wire rope, and the winding of the wire rope around the drum or the discharging of the wire rope from the drum is executed (Claim 6).

Preferably, at least while the tilting device tilts the furnace body, the elevator base is spaced downward from the furnace body, and a vacuum induction furnace is provided between the bottom of the furnace body and the elevator base, The apparatus further comprises a positioning device for determining the position of the furnace body on the lifting platform.
Preferably, the positioning device is provided on one of the furnace body and the lifting platform and has a tapered positioning pin, and a positioning hole provided on the other of the furnace body and the lifting platform and fitted with the positioning pin; (Claim 8).

  Moreover, according to this invention, it is the refining method of the metal material performed using the vacuum induction furnace of any one of Claims 1 thru | or 8, Comprising: The said furnace body is made into the said material injection | throwing-in position with the said raising / lowering apparatus. A positioning step for opening the lid, a material charging step for charging a metal material into the furnace body at the material charging position through a material charging port of the vacuum chamber, and a material charging step. After the entrance process, the furnace body is lowered to the reference position, while the lid body is closed and then the pressure in the vacuum chamber is lowered, and after the descending process, the induction coil is energized. A melting step for melting the metal material, and a tilting step for tilting the furnace body by the tilting device after the melting step and causing the molten metal material to flow out from the upper part of the furnace body. Characterize Refining method of metal material is provided (claim 9).

  Preferably, assuming that the cycle from the ascending step to the melting step is one cycle, the tilting step is executed after the one cycle is executed at least twice (claim 10).

  In the vacuum induction furnace according to the first aspect of the present invention, the material is charged into the furnace body positioned at the material charging position by the lifting device through the material charging port of the vacuum chamber. Since the material charging position is above the reference position, for example, according to a heavy machine such as a scrap processing machine having a fork grapple, the material can be charged directly into the furnace body. Therefore, in this vacuum induction furnace, it is not necessary to release the sling of the material and the sling in the vacuum chamber, and the material can be easily and safely charged into the furnace body.

Further, in this vacuum induction furnace, the material can be easily added, and the material cost is reduced by increasing the usage rate of the return material.
In the vacuum induction furnace according to the second aspect, since the tilting device is composed of a wire rope, the space occupied by the tilting device is narrower than when a cylinder is used. As a result, in this vacuum induction furnace, enlargement of the lifting device and the vacuum induction furnace itself is prevented.

The vacuum induction furnace according to claim 3 has a simple configuration because the lifting device includes a lifting platform and a hydraulic cylinder.
In the vacuum induction furnace according to claim 4, since it is sufficient to raise and lower the lifting platform by one hydraulic cylinder, there is no need to adjust the expansion / contraction speed between the hydraulic cylinders as in the case of using a plurality of hydraulic cylinders. Is easy to control. On the other hand, even if the lifting platform is moved up and down by one hydraulic cylinder, the tilt of the lifting platform is prevented by the guide, so that the stability of the vertical movement of the lifting platform is ensured.

In the vacuum induction furnace according to claim 5, since the guide has a plurality of support columns, a guide rod, and a guide roller, even if the stroke of the cylinder is large and the furnace body is heavy, the tilt of the elevator is surely prevented. Is done.
In the vacuum induction furnace according to the sixth aspect, when the control body moves the furnace body upward, the motor of the tilting device is operated to wind the wire rope around the drum while monitoring the tension applied to the wire rope. On the other hand, the control device operates the motor of the tilting device to release the wire rope from the drum while monitoring the tension applied to the wire rope when the furnace body moves downward. For this reason, when the furnace body is moved up and down by the lifting device, the wire rope is not loosened, and the wire rope is prevented from being wound around the drum in a turbulent state. As a result, the wire rope is prevented from being damaged or broken by the turbulent winding, and the reliability of the tilting device is ensured.

Further, when the furnace body is moved up and down by the lifting device, an appropriate force acts on the furnace body through the wire rope, so that the furnace body on the lifting platform is stabilized and the lifting device operates smoothly.
In the vacuum induction furnace according to claim 7, the lifting platform may be separated downward from the furnace body, but the position of the furnace body on the lifting platform is kept constant by the positioning device. The shift is prevented, and the stability of the vertical movement of the lifting platform is ensured.

In the vacuum induction furnace according to claim 8, the positioning device includes a positioning pin having a male taper surface and a positioning hole having a female taper surface, so that the position of the furnace body on the lifting platform can be simplified. Is definitely determined.
In the metal material refining method according to the ninth aspect, since the vacuum induction furnace according to any one of the first to eighth aspects is used, the metal material can be easily and safely charged into the furnace body.

  In the metal material refining method according to claim 10, since the charging of the material is easy, the refining method is complicated even if the melting step is repeatedly performed from the ascending step, in other words, the metal material is additionally loaded. Never become. On the other hand, according to this refining method, it is possible to increase the usage rate of the bulky return material as the metal material by performing the reattachment of the metal material, and the material cost can be reduced.

FIG. 1 is a cross-sectional view showing a schematic configuration of a vacuum induction furnace according to an embodiment of the present invention.
The vacuum induction furnace is used for refining a metal material, and the refined metal material is taken out from the vacuum induction furnace in a molten state.
Specifically, the vacuum induction furnace has a vacuum chamber 10, and the vacuum chamber 10 is formed by joining a plurality of metal panels. The vacuum chamber 10 has a material inlet 10a for charging a material at an upper portion thereof. The material loading port 10a can be airtightly closed by the lid 12, but the lid 12 can be opened and closed.

The height of the vacuum chamber 10 is about 10 m, for example. The upper part of the vacuum chamber 10, in other words, the material inlet 10a is positioned at the same level as the floor surface in the vertical direction, and most of the vacuum chamber 10 is buried below the floor surface. The floor surface is formed by arranging metal panels, and a heavy machine 13 such as a scrap processing machine can run on the floor surface.
The vacuum chamber 10 is connected to a vacuum pump 16 via an exhaust pipe 14 and a valve (not shown), and the vacuum pump 16 can lower the pressure inside the vacuum chamber 10 below atmospheric pressure. In this specification, the vacuum means a state where the pressure is lower than the atmospheric pressure.

A furnace body 18 is accommodated inside the vacuum chamber 10, and the furnace body 18 has a substantially bottomed cylindrical shape with an open upper end.
2 and 3, an induction coil 20 is wound around the outer periphery of the furnace body 18, and the induction coil 20 is connected to a power source (not shown) disposed outside the vacuum chamber 10. It is connected. By supplying an alternating current from the power source to the induction coil 20, the metal material inside the furnace body 18 is heated and melted. When the metal material is melted under vacuum, impurities such as oxygen in the metal material are removed and the metal material is refined. The refined and melted metal material is poured into, for example, the pan carriage 22 through the steel outlet 10b provided in the vacuum chamber 10.

Note that a box-shaped recess is formed on the one side wall of the vacuum chamber 10 substantially in the center in the height direction. A steel outlet 10b is provided on the upper surface of the recess, and the pan carriage 22 located outside the vacuum chamber 10 enters the recess and receives a metal material of the melting material. The steel outlet 10b can be closed by the partition door 24.
A first pin 26 is attached to the upper portion of the furnace body 18 on the side of the steel outlet 10b on the outer peripheral surface, and the first pin 26 extends horizontally. When the furnace body 18 is in an upright state at the reference position in the vertical direction, the first pin 26 is supported by the support base 28.

A second pin 30 parallel to the first pin 26 is attached to the furnace body 18 via an arm 32, and the second pin 30 is located obliquely above the first pin 26. These first and second pins 26 and 30 serve as fulcrums when the furnace body 18 tilts.
A protrusion 34 is provided on the bottom surface of the furnace body 18 on the side of the steel outlet 10b, and the ends of two wire ropes 38 are fixed to the protrusion 34 via two connecting members 36, for example. The two wire ropes 38 are spaced apart from and parallel to each other in the axial direction of the first and second pins 26 and 30, and extend from two drums 40 disposed in the vicinity of the ceiling of the vacuum chamber 10.

  These drums 40 are arranged on the same axis parallel to the axes of the first and second pins 26 and 30, and are slightly out of the furnace body 18. In other words, the drums 40 are located in the vicinity of the outer edge of the material inlet 10a of the vacuum chamber 10. These drums 40 are connected to a hydraulic motor 42 disposed outside the vacuum chamber 10, and the drum 40 is rotated in the forward direction or the reverse direction by the hydraulic motor 42. The hydraulic motor 42 constitutes a tilting device that tilts the furnace body 18 together with the first pin 26, the second pin 30, the wire rope 38 and the drum 40.

In order to prevent sliding between the outer edge of the bottom surface of the furnace body 18 and the wire rope 38, the bottom surface of the furnace body 18 has a sliding surface having a curved surface in sliding contact with the wire rope 38 on the side opposite to the protrusion 34. A contact portion 46 is formed. Further, a roller 48 is attached to the outer peripheral surface of the furnace body 18 in order to ensure an appropriate gap between the wire rope 38 and the outer peripheral surface of the furnace body 18.
2 and 3, the furnace body 18 is in a reference position when viewed in the vertical direction and is in an upright state. At this time, the furnace body 18 is positioned below the material loading port 10a and is supported by the support base 28 and the drum 40 via the first pin 26, the wire rope 38, and the like.

As shown in FIG. 2, a lifting platform 50 is provided below the furnace body 18, and the lifting platform 50 is supported by a hydraulic cylinder 52. The hydraulic cylinder 52, together with the lifting platform 50, constitutes a lifting device that lifts the furnace body 18 in an upright state.
The hydraulic cylinder 52 has a rectangular cylindrical cylinder case 54 fixed to the bottom of the vacuum chamber 10, and a cylinder rod 56 projects upward from the upper end of the cylinder case 54. The cylinder case 54 and the cylinder rod 56 extend in the vertical direction.

The protruding length of the cylinder rod 56 from the cylinder case 54 increases by increasing the hydraulic pressure supplied to the hydraulic cylinder 52, and decreases by decreasing the hydraulic pressure. That is, the hydraulic cylinder 52 can be expanded and contracted in the vertical direction.
The upper end of the cylinder rod 56 is in contact with the lifting platform 50 from below, and the lifting platform 50 moves up and down as the hydraulic cylinder 52 expands and contracts. The elevator 50 is spaced downward from the furnace body 18 when it is in the lowest position at the lowest position, but pushes the furnace body 18 upward by moving upward from the lowest position.

  More specifically, two metal spacers 57 are fixed on the lifting platform 50. These spacers 57 each have a rectangular parallelepiped shape, and are separated from each other in the axial direction of the first and second pins 26 and 30. The upper surface of the spacer 57 can come into contact with the bottom surface of the furnace body 18, and the furnace body 18 is mounted on the lifting platform 50 via the spacer 57. On the other hand, the spacer 57 secures a gap between the lifting platform 52 and the furnace body 18, and due to the presence of this clearance, the protrusion 34, the sliding contact portion 46, the wire rope 38 and the lifting platform 50 of the furnace body 18 are provided. Contact is avoided.

  One positioning hole 58 is formed on the upper surface of each spacer 57, and two positioning pins 59 protrude from the bottom surface of the furnace body 18. The outer peripheral surface of the positioning pin 59 is formed as a male tapered surface, while the inner peripheral surface of the positioning hole 58 is formed as a female tapered surface having the same taper as the male tapered surface, and each positioning pin 59 has a corresponding positioning hole 58. Can be inserted. These positioning pins 59 and positioning holes 58 constitute a positioning device that determines the position of the furnace body 18 on the lifting platform 50.

In addition, for example, three guide rods 60 are integrally provided on the lifting platform 50. Each guide rod 60 extends in the vertical direction, and the upper end portion of the guide rod 60 is fixed to the lifting platform 50. Three support columns 62 are set up on the bottom surface of the vacuum chamber 10 so as to correspond to the guide rods 60.
As shown in FIG. 4, the guide rods 60 are arranged on a circle centered on the hydraulic cylinder 52 with an interval of 120 degrees when viewed in plan. The struts 62 are located on the radially outer side of the corresponding guide rods 60, and the struts 62 are also arranged on a circle centered on the hydraulic cylinder 52 at intervals of 120 degrees.

  The guide rod 60 and the support column 62 that are paired with each other extend in parallel at a predetermined interval, and the guide rod 60 and the support column 62 have opposing surfaces facing each other. Among these, a rail 64 extending vertically is fixed to the opposing surface of the support column 62, and two guide rollers 66 spaced upward and downward are fixed to the opposing surface of the guide rod 60. The guide roller 66 is engaged with the rail 64 and can run on the rail 64. That is, the guide rod 60 can move in the vertical direction while being guided by the support 62, and constitutes a guide together with the support 62, the rail 64, and the guide roller 66.

In each guide rod 60, the lower guide roller 66 is positioned in the vicinity of the lower end of the guide rod 60, and the upper guide roller 66 is positioned at the upper end of the rail 64 when the hydraulic cylinder 52 is extended most. It is set not to exceed.
Referring again to FIG. 1, the hydraulic cylinder 52 is connected to a hydraulic cylinder driver 70 disposed outside the vacuum chamber 10, and the hydraulic cylinder 52 expands and contracts in response to the supply of hydraulic pressure from the hydraulic cylinder driver 70. A control device 72 is connected to the hydraulic cylinder driver 70, and the hydraulic cylinder driver 70 is controlled by the control device 72. That is, the control device 72 controls the vertical movement of the lifting platform 50 accompanying the expansion and contraction of the hydraulic cylinder 52 via the hydraulic cylinder driver 70. The control device 72 is configured by a computer, for example.

The control device 72 is connected to a hydraulic motor driver 74 that supplies hydraulic pressure to the hydraulic motor 42, and the hydraulic motor driver 74 is controlled by the control device 72. That is, the control device 72 winds the wire rope 38 around the drum 40 accompanying the rotation in the forward direction and the wire rope 38 from the drum 40 accompanying the rotation in the reverse direction via the hydraulic motor driver 74. Control the release.
For example, the output torque of the hydraulic motor 42 is input to the control device 72 via the hydraulic motor driver 74, and the control device 72 monitors the output torque, in other words, the tension of the wire rope 38 while monitoring the hydraulic torque. It is possible to operate the motor 42 and the hydraulic cylinder 52.

Hereinafter, the usage method of the vacuum induction furnace mentioned above is demonstrated.
First, a metal material is inserted into the furnace body 18. For this purpose, as shown in FIG. 5, the lifting device is operated to position the furnace body 18 in the upright state at the material charging position above the reference position. That is, the hydraulic cylinder 52 is extended to raise the furnace body 18 in an upright state (ascending step).
In the state of FIG. 2, the spacer 57 is positioned below the bottom surface of the furnace body 18, but the positioning pin 59 enters the positioning hole 58 when the lifting platform 50 rises a certain distance. When the elevator 50 is further raised from there, the upper surface of the spacer 57 contacts the bottom surface of the furnace body 18 while being positioned by the positioning pins 59 and the positioning holes 58.

While the furnace body 18 is raised, the control device 72 operates the hydraulic motor 42 to rotate the drum 40 in the forward direction and winds the wire rope 38 around the drum 40. At this time, the control device 72 monitors the tension of the wire rope 38 and adjusts the rising speed of the furnace body 18 so that the tension of the wire rope 38 becomes constant.
When the furnace body 18 is positioned at the material charging position, the upper portion of the furnace body 18 slightly protrudes upward from the material charging inlet 10a of the vacuum chamber 10. The lid body 12 is opened before the metal material M is charged into the furnace body 18, but for convenience of drawing, the lid body 12 in the opened state is omitted in FIG.

The furnace body 18 at the material charging position is charged with the metal material M using the heavy machine 13 (material charging process). After the metal material M is charged, the hydraulic cylinder 52 is contracted and the furnace body 18 is lowered to the reference position as shown in FIG. 2 (lowering process).
While the furnace body 18 is lowered, the control device 72 operates the hydraulic motor 42 to rotate the drum 40 in the reverse direction, and releases the wire rope 38 from the drum 40. At this time, the control device 72 monitors the tension of the wire rope 38 and adjusts the descending speed of the furnace body 18 so that the tension of the wire rope 38 becomes constant.

The furnace body 18 is lowered to the reference position, and the first pin 26 contacts the support base 28. At the same time, the rotation of the drum 40 and the contraction of the hydraulic cylinder 52 are stopped, and the inclination of the furnace body 18 is restricted.
On the other hand, after charging the metal material M into the furnace body 18, the material inlet 10a is closed by the lid 12, and the pressure in the vacuum chamber 10 is reduced by the vacuum pump.
After the furnace body 18 is positioned at the reference position and the pressure in the vacuum chamber 10 is sufficiently reduced, an alternating current is supplied to the induction coil 20 to heat and melt the metal material M (melting process). Impurities such as oxygen are removed from the metal material M by melting under reduced pressure.

After the metal material M is heated for a predetermined time under reduced pressure, the furnace body 18 is tilted as follows (tilting process) so that the melted metal material flows out from the furnace body 18 to the pan carriage 22.
First, the hydraulic cylinder 52 is contracted to lower the elevator 50, and the spacer 57 and the elevator 50 are separated downward from the furnace 18 while the furnace 18 is held at the reference position. Next, the hydraulic motor 42 is operated to rotate the drum 40 in the forward direction, and the wire rope 38 is wound around the drum 40. As a result, a rotational moment acts on the furnace body 18, and the furnace body 18 is in the first state until the second pin 30 contacts the upper surface of the recess of the vacuum chamber 10 as shown in FIGS. 6 and 7. The pin 26 is tilted with the fulcrum as a fulcrum, and thereafter the second pin 30 is tilted with the fulcrum as a fulcrum.

As the furnace body 18 tilts, the molten metal material flows out from the upper part of the furnace body 18, and the metal material flows into the pan carriage 22 through the steel outlet 10b. The partition door 24 is opened before the metal material flows out of the furnace body 18, and is closed after the outflow.
After the metal material flows out, the hydraulic motor 42 is operated to rotate the drum 40 in the reverse direction, and the wire rope 38 is released from the drum 40. As a result, the furnace body 18 returns to the upright state in the reverse order.

In order to refine the next metal material, the above-described ascending step to tilting step may be repeated.
In the vacuum induction furnace of one embodiment described above, the metal material M is charged into the furnace body 18 positioned at the material charging position by the lifting device through the material inlet 10a of the vacuum chamber 10. Since the material charging position is above the reference position, the metal material M can be directly charged into the furnace body 18 by using a heavy machine 13 such as a scrap processing machine having a fork grapple, for example. That is, the operator of the heavy machine 13 can charge the metal material M into the furnace body 18 while directly looking at the upper opening of the furnace body 18. Therefore, in this vacuum induction furnace, it is not necessary to release the sling of the metal material M and the sling in the vacuum chamber 10, and the metal material M can be easily and safely inserted into the furnace body 18.

In the vacuum induction furnace of one embodiment, it is easy to add the metal material M, and the material cost is reduced by increasing the usage rate of the return material. This is due to the following reason.
If the usage rate of return materials such as processing scraps and waste materials is increased, the cost of the return materials is low, so the material cost is reduced. However, since the return material is irregular, it is difficult to stake it. If an attempt is made to increase the use rate of the return material using a conventional vacuum induction furnace, the work efficiency deteriorates and the production cost increases.

On the other hand, in the above-described vacuum induction furnace, even if a return material is used, the return material is easily charged into the furnace body 18 by using the heavy machine 13.
On the other hand, since the return material is bulky compared to the slab material etc., the furnace body 18 is not filled with the metal material in one melting process, and work efficiency is achieved when one tilting process is performed per one melting process. Deteriorates and causes an increase in production costs.

In this regard, if the tilting process is performed after repeating this cycle from the ascending process to the melting process, the number of tilting of the furnace body 18 can be reduced, and the increase in production cost is suppressed. Is done.
Thus, according to the vacuum induction furnace described above, by increasing the usage rate of the return material, the material cost is reduced while suppressing an increase in production cost.

In the vacuum induction furnace of one embodiment, since the tilting device is constituted by the wire rope 38, the space occupied by the tilting device is narrower than when a cylinder or the like is used. As a result, in this vacuum induction furnace, enlargement of the lifting device and the vacuum induction furnace itself is prevented.
In addition, the vacuum induction furnace of one embodiment has a simple configuration because the lifting device includes the lifting platform 50 and the hydraulic cylinder 52.

In the vacuum induction furnace of one embodiment, it is only necessary to move the lifting platform 50 up and down by one hydraulic cylinder 52, so there is no need to adjust the expansion / contraction speed between the hydraulic cylinders as in the case of using a plurality of hydraulic cylinders. The control of the hydraulic cylinder 52 is easy.
On the other hand, even if the lifting platform 50 is moved up and down by one hydraulic cylinder 52, the tilt of the lifting platform 50 is prevented by the guide, so that the stability of the vertical movement of the lifting platform 50 is ensured.

  More specifically, there is a distance that allows tilting of the furnace body 18 between the upper part of the furnace body 18 and the material loading inlet 10a when in the reference position, and the hydraulic cylinder 52 substantially corresponds to this distance. You have to stretch as much as you want. When the hydraulic cylinder 52 is in an extended state, the lifting platform 50 on which the furnace body 18 is mounted depends on the mass of the furnace body 18 and the strength of the hydraulic cylinder 52. It tilts and the expansion / contraction operation of the hydraulic cylinder 52 is hindered.

Therefore, in the above-described vacuum induction furnace, a smooth expansion / contraction operation of the hydraulic cylinder 52 is ensured by preventing the lifting platform 50 from being inclined by the guide.
In the vacuum induction furnace according to one embodiment, the guide has a plurality of support columns 62, a guide rod 60, and a guide roller 66, so that the stroke of the hydraulic cylinder 52 is large and the elevator 18 is heavy even if the furnace body 18 is heavy. A tilt of 50 is reliably prevented.

  In the vacuum induction furnace of one embodiment, when the control device 72 moves the furnace body 18 upward, while monitoring the tension applied to the wire rope 38, the hydraulic motor 42 of the tilting device is operated to move the wire rope 38. The drum 40 is wound up. On the other hand, the control device 72 operates the hydraulic motor 42 of the tilting device to release the wire rope from the drum while monitoring the tension applied to the wire rope 38 when the furnace body 18 moves downward. For this reason, when the furnace body 18 is moved up and down by the lifting device, the wire rope 38 is not slackened, and the wire rope 38 is prevented from being wound around the drum 40 in a turbulent winding state. As a result, the wire rope 38 is prevented from being damaged or broken by the turbulent winding, and the reliability of the tilting device is ensured.

Further, when the furnace body 18 is moved up and down by the lifting device, an appropriate force acts on the furnace body 18 through the wire rope 38, so that the posture of the furnace body 18 on the lifting platform 50 is stabilized, and the lifting device Works smoothly.
In the vacuum induction furnace of one embodiment, the lifting platform 50 may be spaced downward from the furnace body 18, but the positioning device keeps the position of the furnace body 18 on the lifting platform 50 constant. The center of gravity of the platform 50 is prevented from being displaced, and the stability of the vertical movement of the elevator platform 50 is ensured.

In the vacuum induction furnace of one embodiment, the positioning device is configured by the positioning pin 59 having the male tapered surface and the positioning hole 58 having the female tapered surface, so that the configuration on the lifting platform 50 can be simplified. The position of the furnace body 18 is reliably determined.
The present invention is not limited to the above-described embodiment, and various modifications are possible.
For example, in one embodiment, the guide roller 66 constituting the guide is fixed to the guide rod 60 and the rail 64 is fixed to the column 62. However, the guide roller 66 is fixed to the column 62 and the rail 64 is fixed to the guide rod 60. It may be fixed to.

  In one embodiment, the positioning pin 59 of the positioning device is provided in the furnace body 18 and the positioning hole 58 is provided in the elevator base 50. However, the positioning pin 59 is provided in the elevator base 50 and the positioning hole 58 is provided in the furnace body. 18 may be provided. Further, the positioning pin 59 and the positioning hole 58 may have inclined surfaces having the same inclination angle instead of the male and female tapered surfaces. In other words, the positioning pin 59 only needs to have a tapered shape, and the positioning hole 58 has an opening larger than the tip of the positioning pin 59, and fits with the positioning pin 59 when the root of the positioning pin 59 is received. If possible.

  In one embodiment, the tilting device has the first and second pins 26 and 30, but only the first pin 26 is provided depending on the relative position between the steel outlet 10 b and the furnace body 18. May be. In order to secure a sufficient gap between one side wall of the vacuum chamber 10 and the furnace body 18, the tilting device preferably has first and second pins 26 and 30.

It is a figure showing roughly the composition of the vacuum induction furnace of one embodiment. It is an enlarged view in the vacuum chamber in the vacuum induction furnace of FIG. It is a figure which shows roughly the structure of the furnace body and its periphery in the vacuum induction furnace of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a figure for demonstrating the material charging method to the furnace body in the vacuum induction furnace of FIG. It is a figure for demonstrating the tilting of the furnace body in the vacuum induction furnace of FIG. It is a figure for demonstrating the tilting of the furnace body in the vacuum induction furnace of FIG.

Explanation of symbols

10 Vacuum chamber
10a Material inlet
12 Lid
18 Furnace
20 induction coil

Claims (10)

A vacuum chamber having a material inlet at the top;
A lid that can open and close the material inlet of the vacuum chamber;
A furnace body housed in the vacuum chamber and positioned below the material inlet;
An induction coil disposed on the outer periphery of the furnace body;
A tilting device for tilting the furnace body in an upright state at a reference position in order to let the material melted inside the furnace body flow out from the upper part of the furnace body;
A vacuum induction furnace comprising: a lifting device that moves the furnace body in an upright state above the reference position to position the furnace body at a material charging position. The tilting device is
A motor for rotating the drum in the forward and reverse directions;
A wire rope that extends from the drum to the furnace body and causes a rotational moment to act on the furnace body as the drum rotates in the forward direction and is wound around the drum. The vacuum induction furnace described. The lifting device is
A lifting platform on which the furnace body is mounted;
The vacuum induction furnace according to claim 1, further comprising at least one hydraulic cylinder disposed below the lifting platform and configured to move the lifting platform in a vertical direction.   The vacuum induction furnace according to claim 3, wherein the lifting device includes one hydraulic cylinder that can be expanded and contracted in the vertical direction and a guide that prevents the lifting platform from being inclined. The guide is
A plurality of support columns standing around the hydraulic cylinder;
A plurality of guide rods extending downward from the lifting platform and facing each other at intervals with a corresponding column among the plurality of columns in a plan view;
The vacuum induction furnace according to claim 4, further comprising a guide roller disposed between the support column and the guide rod. A control device for controlling the operation of the hydraulic cylinder of the lifting device and the motor of the tilting device;
The control device operates the motor while monitoring the tension applied to the wire rope when the furnace body is moved up and down by the lifting device, and winds the wire rope around the drum or from the drum. The vacuum induction furnace according to claim 3, wherein the wire rope is discharged. At least while the tilting device tilts the furnace body, the lifting platform is spaced downward from the furnace body,
7. The apparatus according to claim 3, further comprising a positioning device that is provided between a bottom portion of the furnace body and the lifting platform and determines a position of the furnace body on the lifting platform. Vacuum induction furnace. The positioning device includes:
A positioning pin provided on one of the furnace body and the lifting platform, and having a tapered shape;
The vacuum induction furnace according to claim 7, further comprising a positioning hole that is provided on the other of the furnace body and the lifting platform and engages with the positioning pin. A method for refining a metal material using the vacuum induction furnace according to any one of claims 1 to 8,
While raising and lowering the furnace body by positioning the furnace body at the material input position by the lifting device,
A material charging step of charging a metal material into the furnace body at the material charging position through a material inlet of the vacuum chamber;
After the material charging step, the furnace body is lowered to the reference position, while the lid body is closed and then the pressure in the vacuum chamber is lowered.
After the descending step, a melting step of energizing the induction coil to melt the metal material,
After the melting step, a tilting step of tilting the furnace body with the tilting device and causing the metal material melted from the upper part of the furnace body to flow out is provided. When one cycle is from the ascending process to the melting process,
The method for refining a metal material according to claim 9, wherein the tilting step is performed after the one cycle is performed at least twice.

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