JP4421074B2 - Metal melting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal melting facility in which a metal ingot is preheated to a predetermined temperature, and the preheated ingot is charged into a melting and holding furnace for melting. The present invention is suitable, for example, as a metal melting facility provided in a manufacturing process of a metal die-cast product.
[0002]
[Prior art]
As a material of metal die-cast products, light metals represented by pure metals or alloys such as magnesium, aluminum and zinc are generally used. Generally, the melting equipment provided in the manufacturing process of such a die-cast product includes a melting and holding furnace for melting and holding the raw metal and a preheating device for preheating the raw metal ingot. A die-cast product is manufactured by supplying a required amount of molten metal from a melting and holding furnace to a die-cast machine using a pump or the like. Then, the melting and holding furnace is operated so that the preheating device is replenished with almost the same amount of ingot as that of the molten metal used for die casting, and a fixed volume of molten metal is always held in the melting and holding furnace. The preheating device is provided for the purpose of completely removing the moisture of the ingot to avoid the danger when it is put into the melting and holding furnace and increasing the melting speed of the ingot in the melting and holding furnace.
[0003]
Such a preheating apparatus for melting equipment is usually a preheating furnace mainly containing a large number of rectangular parallelepiped ingots, for example, arranged in a vertically placed state. Between the preheating furnace and the melting and holding furnace, a preheating furnace is used. An ingot transfer device is provided that takes out the ingots one by one and transfers them to the melting and holding furnace. As this transfer device, the ingot in the preheating furnace is grasped by the chuck at the tip of the arm, the arm moves along the rail onto the melting holding furnace, and when the ingot is released from the chuck, the ingot falls into the melting holding furnace. In such a configuration, it is known that the system is inserted.
[0004]
[Problems to be solved by the invention]
In the conventional preheating furnace of the melting equipment, the ingots are arranged in a plane, so that the number of ingots stored is limited or the occupied area increases as the number of stored ingots increases. That is, it is not the structure which can accommodate many ingots in as small a space as possible. Further, in the ingot transfer device, since the ingot is once taken out from the preheating furnace and transferred to the melting and holding furnace, in addition to the temperature of the ingot being lowered during the transfer, there is a risk that the ingot will drop. Yes. In order to suppress the temperature drop of the ingot during conveyance, there are some which cover the ingot with a hood or the like. However, the degree of the temperature drop is only reduced, and further, the apparatus becomes complicated.
[0005]
Accordingly, an object of the present invention is to provide a metal melting facility that can save space in the entire apparatus, effectively suppress a temperature drop of a preheated ingot, and has high safety.
[0006]
[Means for Solving the Problems]
The present invention is a metal melting facility for charging a plurality of metal ingots into a melting and holding furnace one by one by a charging device from a preheating apparatus that houses and preheats a plurality of metal ingots, and melts the ingot in the melting and holding furnace. The preheating device and the charging device have the following characteristics.
[0007]
First, the preheating device is rotatably supported on the frame via a substantially horizontal stocker shaft extending toward the melting and holding furnace, and a plurality of ingot storage portions are arranged along a circumferential direction concentric with the stocker shaft. A stocker, a transfer means for transferring the ingot in the ingot storage part moved to a predetermined ingot transfer position with the rotation of the stocker to a charging device, and a heating means for heating the ingot in the stocker to a predetermined preheating temperature. .
[0008]
The charging device is rotatably supported by the frame via a chute shaft extending in a substantially horizontal direction orthogonal to the stocker shaft, and an ingot delivery position for receiving the ingot from the stocker at the ingot transfer position, and a melting holding furnace A chute that reciprocates between an ingot charging position for dropping the ingot into the melting and holding furnace from the ingot charging port, a shutter that opens and closes the ingot dropping port of the chute, and shutter driving means that drives the shutter to open and close ing.
[0009]
According to the preheating device according to the present invention, the ingots are stored one by one in the ingot storage part of the stocker and heated to a predetermined preheating temperature by the heating means. The stocker is rotatably supported by the frame via a substantially horizontal stocker shaft, and is configured in an annular or disk shape. The ingot storage portions are arranged in an annular shape along the circumferential direction of the stocker. Therefore, a significant space saving can be achieved as compared with the case where the ingots are arranged in a plane. A fixed position where the rotation trajectory of the ingot storage part accompanying the rotation of the stocker is determined as the ingot transfer position, and transfer means is provided in the vicinity thereof. The transfer means transfers the ingot in the ingot storage unit moved to the ingot transfer position by the rotation of the stocker to the chute of the charging device.
[0010]
The chute of the charging device receives the ingot from the ingot storage portion of the stocker in a state where the chute is at the ingot delivery position. Next, the chute that has received the ingot is rotated to the ingot loading position with the chute shaft as a fulcrum. Thereby, the ingot dropping port of the chute continues to the ingot charging port of the melting and holding furnace. Here, the ingot is stopped by the shutter by closing the shutter. Next, when the shutter is opened by the shutter driving means, the ingot is put into the melting and holding furnace.
[0011]
According to the charging device according to the present invention, the preheated ingot can be quickly transferred from the stocker's ingot storage part to the melting and holding furnace, and therefore, the temperature drop of the ingot can be effectively suppressed. Further, since the ingot is received by the chute and transferred to the melting and holding furnace, there is no risk of dropping the ingot, and the operation can be safely performed.
[0012]
Further, in the present invention, the following configuration is added to the above-described charging device.
[0013]
That is, the above-described charging device includes a stop member that receives an ingot falling from the chute into the melting and holding furnace and temporarily stops the drop, and an extrusion member that pushes out the ingot received by the stop member and drops the ingot from the stop member. And are added.
[0014]
In the melting and holding furnace, a certain amount of molten metal maintained at a predetermined temperature is always maintained, and an ingot is dropped into the molten metal, and a phenomenon that the molten metal is scattered often occurs at that time. The molten metal splashes not only in the melting and holding furnace, but sometimes jumps out from the ingot inlet of the melting and holding furnace, which causes a problem that the inside of the furnace and the chute are contaminated. Therefore, the problem can be solved by adding the stop member and the pushing member. The action is to temporarily receive the ingot falling from the chute by the stopping member, thereby preventing the ingot from dropping directly onto the molten metal, and then extruding the ingot with the pushing member to separate it from the stopping member. Then, the ingot slowly enters the molten metal and the molten metal is prevented from scattering. In this embodiment, it is preferable to set the distance (height) between the stop member and the molten metal surface as short as possible from the viewpoint that the effect of preventing the molten metal from scattering when the ingot is charged is sufficiently exhibited.
[0015]
(1) The stop member may be provided with a guide portion that causes the ingot dropped by the pushing member to drop obliquely into the melting and holding furnace . By this guide portion, the ingot is dropped obliquely with respect to the molten metal surface of the melting and holding furnace, and the effect of preventing the molten metal from scattering is enhanced. As a specific configuration of the guide portion, a slide-like plate piece or the like heading obliquely with respect to the molten metal surface can be given.
[0016]
(2) The pushing member may be driven by shutter driving means . The shutter drive means opens and closes the shutter that opens and closes the chute ingot drop opening. However, the shutter drive means can also serve as a drive means for the push-out member, thereby reducing the number of parts and simplifying the structure.
[0017]
(3) In the state where the chute is in the ingot loading position, the throwing device is disposed between the shutter and the stop member so as to be able to advance and retreat with respect to the falling trajectory of the ingot. At least one intermediate stop member for temporarily stopping may be added . In the embodiment in which the intermediate stop member is added, when the ingot is dropped from the chute by opening the shutter, the intermediate stop member is advanced on the ingot drop locus. The ingot falling from the chute is temporarily stopped by the intermediate stop member before being received by the stop member, and then when the intermediate stop member is retracted, the ingot is continuously dropped and stopped by the stop member. By disposing the intermediate stop member between the shutter and the stop member, the impact of the ingot on the stop member becomes weak, so that the stop member can be prevented from being damaged.
[0018]
(4) The intermediate stop member may be driven by shutter driving means . Since the shutter driving means also serves as the driving means for the intermediate stop member, the number of parts can be reduced and the structure can be simplified. In addition, (2) may be combined with this embodiment, and the shutter driving unit may be configured to drive both the pushing member and the intermediate stop member. In that case, the shutter driving means drives the three elements of the shutter, the push-out member, and the intermediate stop member all at once, thereby further reducing the number of parts and simplifying the structure.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a melting facility according to an embodiment, and FIG. 2 is a view taken along the line II-II in FIG. The melting equipment includes a preheating device 10 that heats a large number of stored ingots M to a predetermined preheating temperature, a melting and holding furnace 30 that is disposed in front of the preheating device 10 (leftward in FIG. 1), and the preheating device 10. The charging and holding furnace 30 includes a charging device 40 for charging ingots M one by one. The ingot M in this case has a rectangular parallelepiped shape with a trapezoidal cross section. Hereinafter, these will be described in order.
[0020]
A. Preheating device Reference numeral 11 in FIGS. 1 and 2 is a frame that supports the preheating device 10. On the rear side (right side in FIG. 1) of the frame 11, a drum-like casing 12 is fixed in a state where its axial direction is horizontal. The frame 11 supports both ends of a stocker shaft 13 that passes through the axis of the casing 12. A stocker 14 is supported in the casing 12 so as to be rotatable about the stocker shaft 13.
[0021]
The stocker 14 has a configuration in which a large number (30 in this case) of racks (ingot storage portions) 16 in which one ingot M is stored are arranged in an annular rack frame 15 concentric with the stocker shaft 13. The rack frame 15 is supported by a plurality of spokes 17 extending radially from both ends of the stocker shaft 13, and the entire stocker 14 is rotatable together with the spokes 17 around the stocker shaft 13. The rack 16 is a tubular body having a rectangular cross section and an overall rectangular parallelepiped shape, the longitudinal direction is parallel to the stocker shaft 13, and the longitudinal direction in the cross section is a radial shape centered on the stocker shaft 13. They are arranged at equal pitches along the circumferential direction of the frame 15.
[0022]
At the ingot transfer position which is the uppermost part of the casing 12, a cylinder device (transfer) which pushes the ingot M in the rack (indicated by reference numeral 16 </ b> A in FIG. 2) moved here to the chute 41 of the input device 40 which will be described later. Means) 20 is provided. The cylinder device 20 includes a cylinder body 21 that extends rearward from the casing 12 and a rod 23 that is connected to the mover 22 of the cylinder body 21 and inserted into the casing 12. The rod 23 moves forward / backward along its own axial direction as the mover 22 moves. In addition, as the rack 16 for storing the ingot M, a circular tube may be used. In this case, the contact form with the ingot M is a line contact, which is preferable because friction during transfer is reduced.
[0023]
When the rod 23 moves forward, the rod 23 enters the rack 16A, and the ingot M in the rack 16A is pushed out from the transfer port (not shown) formed in the casing 12 into the chute 41 of the charging device 40, and at the forward stroke end. The ingot M is completely transferred into the chute 41. Further, at the end of the reverse stroke, the rod 23 is retracted from the rack 16A, thereby allowing the stocker 14 to rotate. The casing 12 is provided with a sleeve 12a for guiding the rod 23 to advance and retreat. The stocker 14 is intermittently rotated in one direction by one pitch of the rack 16 so that one rack 16 temporarily stops at the uppermost ingot transfer position by a rotation driving means (not shown).
[0024]
As shown in FIG. 2, the frame 11 is provided with a gas burner device (heating means) 25 for heating the ingot M in the rack 16 to a predetermined preheating temperature by heating the inside of the casing 12.
[0025]
B. Melting and holding furnace Next, the melting and holding furnace 30 will be described with reference to FIG.
The melting and holding furnace 30 is a crucible induction furnace, the reference numeral 31 is a furnace body in which a heat insulating material is lined on the outer plate, and the reference numeral 32 is a crucible. A coil 33 surrounding the crucible 32 is embedded in the heat insulating material. By passing a high-frequency current through the coil 33, an eddy current is generated in the metal in the crucible 32 and the metal is heated or melted. The opening of the crucible 32 is covered with a furnace lid 34, and an ingot charging port 35 is formed at a predetermined position of the furnace lid 34.
[0026]
C. Input device Next, the input device 40 will be described with reference to FIG.
The charging device 40 mainly includes a chute 41 provided on the preheating device 10 side and a buffer mechanism 60 provided on the melting and holding furnace 30 side.
[0027]
The chute 41 is a tubular body having a rectangular cross section and an overall rectangular parallelepiped shape. The chute 41 receives the ingot M from the preheating device 10 and puts the received ingot M into the melting and holding furnace 30. The chute 41 is rotatably supported by a chute frame 42 that extends horizontally from the frame 11 to above the melting and holding furnace 30. A chute shaft 43 extending in the left-right direction (the front and back direction in FIG. 3) is provided at the tip of the chute frame 42, and the chute 41 is attached to the chute shaft 43 via the stay 44 in the directions of arrows F and R in FIG. Is supported rotatably. The chute 41 is rotated by driving means such as a cylinder or a motor.
[0028]
When the chute 41 rotates in the direction of arrow R, the rear end opening continues to the delivery port of the casing 12. At the ingot delivery position, the chute 41 is arranged in line with the rack 16A at the ingot transfer position. The ingot dropping port 45 which is the tip opening of the chute 41 is viewed in the ingot delivery position so that the ingot dropping port 45 is continuous with the ingot loading port 35 of the melting and holding furnace 30 in the ingot loading position described below. And tilted forward.
[0029]
On the other hand, when the chute 41 rotates in the direction of arrow F, the ingot dropping port 45 continues to the ingot loading port 35 of the melting and holding furnace 30 and reaches the ingot loading position where the whole is inclined slightly rearward. The chute 41 reciprocates from the ingot delivery position to the ingot insertion position. A shutter plate (shutter) 46 that opens and closes the drop opening 45 is provided at the ingot drop opening 45 of the chute 41. The shutter plate 46 is slidably accommodated in a shutter holder 47 attached to the tip of the chute 41, and a fitting hole (not shown) for fitting with a pin 61a described later is formed at the rear end. Yes. The ingot loading position of the chute 41 is determined by the shutter holder 47 coming into contact with a cylindrical receiving seat 36 provided around the ingot loading port 35.
[0030]
In the chute 41, a pressing plate 48 that presses the ingot M against the bottom of the chute 41 at all times is provided. The pressing plate 48 is always urged in a direction in which the ingot M is pressed against the bottom of the chute 41 by a link 49 provided outside the chute 41 and a tension spring 50 connected to the link.
[0031]
The buffer mechanism 60 stops the ingot M falling from the chute 41 in two stages to buffer the momentum of the drop, and includes a plate-like first stopper (intermediate stop member) 61, second stopper (stop member) 62, It has. The first stopper 61 opens and closes a portion directly below the receiving seat 36 in the ingot inlet 35 by a cylinder device (shutter driving means) 63 provided in the melting and holding furnace 30. The cylinder device 63 is installed in the melting and holding furnace 30 via a stay 66 so that the piston 65 advances and retreats from the cylinder body 64 toward the ingot insertion port 35. The front end of the piston 65 is engaged with a pin 61 a erected on the rear end portion of the first stopper 61. When the chute 41 reaches the ingot insertion position, the pin 61a is fitted with a fitting hole of the shutter plate 46 in the closed state. In addition, a pusher (extrusion member) 67 is attached to the tip of the first stopper 61 so as to hang vertically from the tip and then incline forward downward and enter the crucible 32.
[0032]
The second stopper 62 is fixed to the cylinder device 63 side around the ingot insertion port 35 below the first stopper 61, and is horizontally disposed at the tip of the base portion 62 a that inclines forward and enters the crucible 32. A stop portion 62b and a guide portion 62c inclined downward are formed. In the second stopper 62, the base portion 62a is substantially aligned with the bottom portion of the chute 41 at the ingot loading position, and the ingot M falling from the chute 41 is received by the stop portion 62b. In addition, a slit (not shown) that allows the pusher 67 to pass when the first stopper 61 is retracted by the piston 65 of the cylinder device 63 is formed in the base portion 62a.
[0033]
The above is the melting equipment of the present embodiment, and subsequently, the operation of the melting equipment and the effects associated therewith will be described. It is assumed that the ingot M is made of a magnesium alloy, and a certain volume of molten magnesium alloy M1 is held in the crucible 32 of the melting and holding furnace 30. As an initial state of operation, the inside of the casing 12 of the preheating device 10 is heated by the gas burner device 25, whereby the ingots M in each rack 16 are heated and held at a predetermined preheating temperature (200 to 300 ° C.). Further, the chute 41 of the charging device 40 is in the ingot delivery position, and the shutter plate 46 is closed. Further, the first stopper 61 closes the ingot inlet 35 when the piston 65 of the cylinder device 63 moves forward, and the pin 61a is in a position where the fitting hole of the shutter plate 46 can be fitted.
[0034]
Now, from the initial state, with the rod 23 of the cylinder device 20 in the preheating device 10 in the backward stroke end, the stocker 14 rotates by one pitch of the rack 16 and one rack (indicated by reference numeral 16A in FIG. 2). Is temporarily stopped at the uppermost ingot transfer position. Next, the rod 23 moves forward to push out the ingot M in the rack 16 </ b> A and move it to the chute 41.
[0035]
The chute 41 containing the ingot M rotates in the direction of arrow F in FIG. 3, and is arranged at the ingot loading position as shown in FIG. The ingot M is pressed against the bottom of the chute 41 by the pressing plate 48 while the chute 41 is rotating or at the ingot loading position. In this state, the ingot M is placed on the shutter plate 46 and is kept from dropping. Further, the fitting hole of the shutter plate 46 fits the pin 61 a at the tip of the piston 65.
[0036]
Next, the piston 65 of the cylinder device 63 is retracted. Then, as shown in FIG. 4B, the shutter plate 46 is retracted by being pulled by the pin 61a, the ingot dropping port 45 of the chute 41 is opened, and the first stopper 61 is retracted halfway. As a result, the ingot M is dropped to the first stopper 61 and stopped.
[0037]
Subsequently, the piston 65 of the cylinder device 63 is further retracted. Then, as shown in FIG. 5A, the first stopper 61 is completely retracted, and the ingot M is dropped to the stop portion 62 b of the second stopper 62 and stopped. Next, as shown in FIG. 5B, the piston 65 of the cylinder device 63 is slightly advanced. Then, the pusher 67 at the tip of the first stopper 61 pushes out the ingot M placed on the stop portion 62 b of the second stopper 62. As shown in FIG. 6 (a), the ingot M pushed out by the pusher 67 slides from the stop 62b to the guide part 62c at the end thereof, and finally, as shown in FIG. 6 (b). Then, it sinks while falling obliquely with respect to the surface of the molten metal M1 along the guide portion 62c.
[0038]
In this way, the ingot M is charged into the crucible 32 of the melting and holding furnace 30, and when the charging is completed, the charging device 40 is returned to the initial state and waits for the next charging operation of the ingot M.
[0039]
The melting equipment of the present embodiment has the following operational effects.
First, in the preheating device 10, since a large number of ingots M are arranged in an annular manner in the stocker 14 in the drum-like casing 12 arranged vertically, the ingot M is occupied in the stock state as compared with the case where they are arranged in a plane. The area is small, and a significant space saving is achieved.
[0040]
Further, in the process of charging the ingot M from the preheating device 10 into the crucible 32 of the melting and holding furnace 30, the ingot M is transferred to the chute 41 of the charging device 40 by the cylinder device 20 provided in the preheating device 10, and subsequently the chute 41 , The ingot M can be quickly put into the crucible 32. By realizing such a quick charging operation, the ingot M at the time of charging is substantially held at the preheating temperature. Moreover, since the ingot M is thrown into the crucible 32 while keeping the state received by the chute 41, there is no risk of dropping the ingot M, and safe operation can be performed.
[0041]
Further, when the ingot M is put into the crucible 32, the falling momentum is buffered by stopping the dropping of the ingot M in two stages by the buffer mechanism 60. For this reason, the molten metal M1 does not scatter when the ingot M falls, and contamination in the melting and holding furnace 30 and the chute 41 is prevented. In particular, since the ingot M is guided to the guide portion 62c of the second stopper 62 and falls obliquely with respect to the surface of the molten metal M1, the molten metal M1 is further prevented from being scattered. Further, in the buffer mechanism 60, since the first stopper 61 is provided between the shutter plate 46 that receives the ingot M in the chute 41 and the second stopper 62, the impact of the ingot M on the second stopper 62 is provided. As a result, the second stopper 62 can be prevented from being damaged.
[0042]
In addition, the cylinder device 63 that opens and closes the shutter plate 46 also serves as the second stopper 62 and the driving means for the pusher 67 fixed to the second stopper 62, so that the number of parts can be reduced and the structure can be simplified. Achieved.
[0043]
【The invention's effect】
As described above, according to the present invention, it is possible to save the space of the entire apparatus, to effectively suppress the temperature drop of the preheated ingot, and to perform safe operation.
[Brief description of the drawings]
FIG. 1 is a side view of a melting facility according to an embodiment of the present invention.
FIG. 2 is a view taken along the line II-II in FIG.
FIG. 3 is a side view showing a dosing device according to an embodiment of the present invention.
FIG. 4 is a side view showing the initial stage of operation of the dosing device according to the embodiment of the present invention in the order of (a) and (b).
FIG. 5 is a side view showing the next stage of the operation of the charging device according to the embodiment of the present invention in the order of (a) and (b).
FIG. 6 is a side view showing the final stage of the operation of the charging device according to the embodiment of the present invention in the order of (a) and (b).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Preheating apparatus 11 ... Frame 13 ... Stocker shaft 14 ... Stocker 16 ... Rack (ingot storage part)
20 ... Cylinder device (transfer means)
25 ... Gas burner device (heating means)
30 ... Melting and holding furnace 35 ... Ingot charging port 40 ... Loading device 41 ... Chute 43 ... Chute shaft 45 ... Ingot dropping port 46 ... Shutter plate (shutter)
61 ... First stopper (intermediate stop member)
62 ... Second stopper (stopping member)
62c ... Guide portion 63 ... Cylinder device (shutter driving means)
67 ... pusher (extrusion member)
M ... Ingot M1 ... Molten metal

Claims (5)

From a preheating device that houses and preheats a plurality of metal ingots, a metal melting facility that throws ingots into a melting and holding furnace one by one by a charging device, and melts and holds the ingot in the melting and holding furnace,
The preheating device is:
A stocker in which a plurality of ingot storage portions are arranged along a circumferential direction concentrically with the stocker shaft, which is rotatably supported on a frame via a substantially horizontal stocker shaft extending toward the melting and holding furnace,
A transfer means for transferring the ingot in the ingot storage part moved to a predetermined ingot transfer position with the rotation of the stocker to the charging device;
Heating means for heating the ingot in the stocker to a predetermined preheating temperature,
The charging device is
An ingot delivery position that is rotatably supported by the frame via a chute shaft that extends in a substantially horizontal direction perpendicular to the stocker shaft, and that receives an ingot from the ingot storage portion at the ingot transfer position, and the melting and holding furnace A chute that reciprocates between an ingot input position for dropping the ingot into the melting and holding furnace from the ingot input port of
A shutter that opens and closes the ingot drop opening of the chute;
Shutter driving means for opening and closing the shutter, and
The charging device includes a stop member that receives an ingot falling into the melting and holding furnace from the chute and temporarily stops the dropping, and an extrusion member that extrudes the ingot received by the stop member and drops the ingot from the stop member. Metal melting facility characterized by being added . The metal melting facility according to claim 1 , wherein the stop member of the charging device is provided with a guide portion that obliquely drops an ingot dropped by the pushing member into the melting and holding furnace. The extrusion member is a metal melting equipment according to claim 1 or 2, characterized in that it is driven by the shutter driving means. In the state where the chute is in the ingot loading position, the throwing device is disposed between the shutter and the stop member so as to be movable back and forth with respect to the ingot dropping trajectory. The at least 1 intermediate | middle stop member which stops once is added, The metal melting | dissolving installation in any one of Claims 1-3 characterized by the above-mentioned. The metal melting facility according to claim 4 , wherein the intermediate stop member is driven by the shutter driving unit.

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