Hand at the tip of a robot arm device and method for handling a crucible using the same

Abstract

To provide a hand in a robot arm device capable of arranging plural crucibles on a mounting face at high density.SOLUTION: A hand 106 is made of a bar-shaped base part 110 and a bar-shaped movable part 120 fitted to the tip part of a robot arm device 31 and mutually separated, and sandwiching crucibles C by their mutually confronted tip contact parts from both sides. The movable part 120 is rotatably supported by a support part 111 projecting from almost the central part of the base part 110 at almost the central part of the movable part, and further, the terminal part on the side opposite to the tip contact part of the movable part 120 is rotatably connected by a rod 113 projecting from reciprocation means 112 provided at the terminal part on the side opposite to the tip contact part of the base part 110 in the projection direction of the support part 111.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a hand attached to the tip of a robot arm device and a method for handling a crucible using the hand.

Background Art

[0002] As a method for quantitatively analyzing precious metal components such as gold and silver contained in ores, a dry assay method is known. In the dry assay method, a sample prepared by mixing an ore to be analyzed with lead oxide and a flux is placed in a crucible, which is then charged into a melting furnace and melted to dissolve precious metals such as gold and silver into lead and separate them from other metals. A quantitative analysis method is used in which only the precious metal is taken out and its mass is measured by treating the obtained alloy of the precious metal and lead by the cupellation method.

[0003] In the above dry assay method, after charging the crucible containing the sample into the melting furnace and sufficiently melting the sample in the crucible by heating it at a temperature condition of, for example, 1200°C for a predetermined time, it is necessary to take out the crucible from the melting furnace and quickly pour the molten sample inside into a mold. Conventionally, an operator has manually performed these series of operations using crucible tongs. Therefore, the operator has to work in an environment close to the melting furnace at a high temperature, which places a heavy burden on the operator and requires various measures to ensure safety.

[0004] Therefore, in order to reduce the workload of the operator and eliminate safety issues, it has been proposed to automate the handling of crucibles during dry assaying that relied on manual labor as described above. For example, Patent Document 1 discloses a sample melting apparatus comprising a rotatable circular pedestal having a placement surface for a plurality of crucibles, a melting furnace that sequentially loads a plurality of crucibles continuously conveyed by the pedestal and melts the samples inside, and a robot arm device that places a crucible containing a sample before melting on the placement surface upstream of the loading port of the melting furnace, or lifts a crucible containing a molten sample placed on the placement surface downstream of the discharge port of the melting furnace. The tip of the robot arm device of this Patent Document 1 is provided with chuck means constituted by a claw member that can be opened and closed, and it is described that the crucible is gripped by this chuck means.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described above, the chuck means constituted by the claw member provided at the tip of the robot arm device generally has a structure in which the end portions of a pair of rod-shaped claw members are rotatably coupled to each other. Therefore, when lifting a plurality of crucibles simultaneously with this chuck means, it was necessary to widely expand the claw members in a substantially V shape with the rotatable coupling portion as a fulcrum. Therefore, in order to prevent physical interference with other crucibles when the claw members are expanded in this way, it was necessary to leave a large gap between adjacent crucibles when placing the crucibles on the placement surface of the pedestal, and the processing capacity of the sample melting apparatus could not be increased by arranging the crucibles at high density.

[0007] The present invention has been made in view of the above circumstances, and when arranging a plurality of crucibles side by side on the mounting surface of a conveying means such as a belt conveyor and sequentially loading them into a heating furnace such as a melting furnace, it is possible to arrange the plurality of crucibles densely on the mounting surface. The object is to provide a hand of a robot arm device.

Means for Solving the Problems

[0008] In order to achieve the above object, the hand attached to the tip of the robot arm device according to the present invention is composed of a rod-shaped base portion and a rod-shaped movable portion that are spaced apart from each other and attached to the tip of the robot arm device, and the tip contact portions facing each other of these are used to sandwich the container from both sides. It is a hand, and the movable portion is rotatably supported at a substantially central portion thereof by a support portion protruding from a substantially central portion of the base portion, and is provided at a distal end portion of the base portion on the side opposite to the tip contact portion. The distal end portion of the movable portion on the side opposite to the tip contact portion is rotatably connected by a rod that protrudes and retracts in the protruding direction of the support portion from the reciprocating means provided at the distal end portion. The movable part is composed of a plurality of plate-like bodies stacked in the thickness direction, and their lengths from the portion supported by the support part to the tip contact part are all different, and each of the plurality of plate-like bodies sandwiches one container in cooperation with the base part It is characterized by this.

Effects of the Invention

[0009] According to the present invention, when sequentially loading a plurality of crucibles into a heating furnace by a conveying means and heating them, the plurality of crucibles can be arranged densely on the mounting surface of the conveying means, so the processing capacity of the heating furnace can be increased.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the hand according to the present invention will be described in detail with reference to the drawings. The hand of this embodiment of the present invention is a so - called end - effector attached to the tip of a robot arm device, and among the placement surfaces of the conveying means that continuously or intermittently conveys a plurality of substantially cylindrical containers containing the object to be heated and sequentially loads them into the heating furnace, it has a function of placing one or more crucibles at a position upstream of the loading port of the heating furnace, and a function of lifting one or more of the containers waiting at a position downstream of the discharge port of the heating furnace.

[0012] The above - mentioned heating furnace is not particularly limited. It may be a heating furnace that continuously heats a plurality of crucibles conveyed by an endless - track belt conveyor running in a horizontal one - direction by sequentially passing them through a tunnel - shaped heating furnace, or a heating furnace that continuously heats a plurality of crucibles conveyed by a circular or annular base rotating around a central axis extending in the vertical direction by sequentially passing them through a tunnel - shaped heating furnace. Also, the use of the heating furnace is not particularly limited, but in the following embodiments of the present invention, for the purpose of quantitatively analyzing precious metals such as gold and silver contained in ores by dry assay analysis, a case where it is a melting furnace that melts a sample by sequentially loading a plurality of crucibles containing a sample prepared by mixing the ore with lead oxide and a flux into the furnace by conveyance by an endless - track belt conveyor will be described as an example.

[0013] 1. Melting device A melting apparatus for melting a sample, which is the content of a crucible handled by a hand according to an embodiment of the present invention, includes a conveying means for continuously or intermittently conveying a plurality of crucibles placed on a placement surface, and a melting furnace for melting the sample, which is the content of these crucibles, by heating them while the plurality of crucibles conveyed by this conveying means sequentially pass through a tunnel-shaped furnace.

[0014] Specifically, the conveying means is, for example, a belt conveyor having an endless track, and the traveling route is defined so as to enter from the loading port of the melting furnace, travel in one direction along the bottom portion of the melting furnace, and then exit from the discharge port on the opposite side. As a result, among the conveyor surfaces that serve as the placement surfaces of the belt conveyor, the crucibles sequentially placed at the pre-loading crucible placement position upstream of the loading port of the melting furnace by the robot arm device described later are loaded from the loading port of the melting furnace by the continuous or intermittent traveling of the belt conveyor, and the sample in the crucible is melted by being heated inside the melting furnace. The crucible containing the sample melted in the melting furnace is conveyed from the discharge port of the melting furnace by the continuous or intermittent conveyance of the belt conveyor, and then conveyed to the post-discharge crucible standby position downstream of this discharge port, where it is lifted by the above-described robot arm device.

[0015] 2. Robot Arm Device For a robot arm device that places a crucible on the above conveyor surface or lifts the crucible from the conveyor surface, it is preferable to use a robot with a vertically articulated structure, also called a manipulator having, for example, the shape shown in FIG. 1. The robot arm device shown in FIG. 1 generally includes a base portion 1 fixed to the floor surface with bolts or the like, a swivel portion 2 provided on the upper surface portion of the base portion 1 so as to be horizontally rotatable about the A1 axis, and a vertical link portion (lower arm portion) 3 pivotally connected to the upper end portion of the swivel portion 2 so as to be rotatable back and forth about the A2 axis. A horizontal link portion (upper arm portion) 4 pivotally connected to the tip end portion of the vertical link portion 3 so as to be vertically rotatable about the A3 axis, and a wrist portion 5 pivotally connected to the tip end portion of the horizontal link portion 4 so as to be rotatable about the A4 axis. The wrist portion 5 is bent about the A5 axis at its central portion, and at its tip end portion, a hand 6 of the first embodiment of the present invention or a hand 106 of the second embodiment described later is pivotally attached about the A6 axis. Next, the hand 6 of the first embodiment of the present invention and the hand 106 of the second embodiment attached to the tip end portion of this robot arm device will be specifically described.

[0016] 3. Hand As shown in FIG. 2, the hand 6 of the first embodiment of the present invention is composed of a rod-shaped base portion 10 and a rod-shaped movable portion 20 that are spaced apart from each other. By sandwiching a crucible C, which is a substantially cylindrical container with a reduced diameter downward, from both horizontal sides by the opposing tip contact portions thereof, it can be clamped. Specifically described, at a substantially central portion in the longitudinal direction of the base portion 10, a support portion 11 composed of a pair of long plate-like members protruding in a direction perpendicular to the longitudinal direction is provided. A round bar 11a is provided across both tip end portions of the pair of plate-like members constituting the support portion 11, and a through hole provided at a substantially central portion in the longitudinal direction of the movable portion 20 is inserted through the round bar 11a. Thereby, the movable portion 20 is rotatably supported by the support portion 11 at its substantially central portion.

[0017] Further, the base 10 is provided with reciprocating means 12 at the end portion on the side opposite to the tip contact portion in the longitudinal direction thereof. The reciprocating means 12 is configured such that the rod 13 protrudes and retracts in the direction in which the support portion 11 protrudes, and the end portion of the movable portion 20 in the longitudinal direction, which is opposite to the tip contact portion, is rotatably connected to the tip of the rod 13.

[0018] There is no particular limitation on the specific type of the reciprocating means 12 described above, but an air cylinder that advances and retracts the rod by introducing and exhausting compressed air into a cylindrical cylinder is preferably used. As a method of retracting the rod 13 into the cylinder, there are a single-acting type that utilizes the force of a spring that biases in the direction opposite to the advancing direction, and a double-acting type that alternately introduces compressed air into both spaces partitioned by a piston connected to the rod in the cylinder.

[0019] When lifting the crucible C using the hand 6 having such a structure, the robot arm device is operated so that the crucible C to be clamped is positioned between the tip contact portion of the base 10 and the tip contact portion of the movable portion 20. In this state, when the reciprocating means 12 is an air cylinder, compressed air is introduced into the cylinder to advance the rod 13. As a result, the end portion of the movable portion 20 moves in a direction away from the end portion of the base 10, so the movable portion 20 rotates in one direction with the support portion 11 of the base 10 as a fulcrum, and the tip contact portion of the movable portion 20 approaches the tip contact portion of the base 10.

[0020] As a result, the tip contact portion of the movable portion 20 first contacts the side wall portion of the crucible C, and then further approaches the tip contact portion of the base 10 together with the crucible C. Finally, the side of the side wall portion of the crucible C opposite to the side where the tip contact portion of the movable portion 20 contacts contacts the tip contact portion of the base 10. Thus, the clamping of the crucible C by the opposing tip contact portions of the base 10 and the movable portion 20 is completed. By operating the robot arm device while maintaining the state in which the crucible C is clamped by the hand 6 in this way, the crucible C can be moved to a predetermined location.

[0021] When placing the crucible C in the above-described clamped state on the placement surface at the destination, the operations may be performed in the reverse order to that when clamping. That is, first, the robot arm device is operated to place the crucible C clamped by the hand 6, for example, on a table. When the reciprocating means 12 is a single-acting air cylinder, compressed air is exhausted from the cylinder. As a result, since the rod 13 retracts into the cylinder, the movable part 20 moves in a direction approaching the end part of the base part 10, and the movable part 20 rotates in the opposite direction to when clamping the crucible C with the support part 11 of the base part 10 as a fulcrum, and the tip contact part of the movable part 20 is displaced in a direction away from the tip contact part of the base part 10.

[0022] As a result, since the tip contact part of the movable part 20 is separated from the side wall part of the crucible C, after slightly moving the hand 6 horizontally so that the tip contact part of the base part 10 is also separated from the side wall part of the crucible C, the hand 6 is lifted straight up or horizontally moved so as to be pulled out in the longitudinal direction of the base part 10. Thereby, the placement of the crucible C at a predetermined location is completed. As described above, the hand 6 of the first embodiment of the present invention can displace the opposing tip contact parts of the base part 10 and the movable part 20 in a direction of separation or conversely approach them by projecting and retracting the rod from the reciprocating means 12 provided at the end part of the base part 10. Therefore, it is possible to clamp or release the crucible C by appropriately adjusting the separation distance when they are closest to each other.

[0023] Also, as shown in FIG. 2, since a plurality of crucibles C can be simultaneously clamped by sandwiching them from both sides while arranged in a row, it is possible to handle a plurality of crucibles C extremely efficiently. In particular, as will be described later, it is advantageous when loading a plurality of crucibles C into a tunnel-shaped heating furnace by conveying them with a belt conveyor. That is, in order to increase the processing capacity of the heating furnace, it is preferable that the rows of a plurality of crucibles C placed in the width direction of the belt conveyor are as close as possible to the rows of other crucibles C adjacent in the running direction of the belt conveyor.

[0024] However, since one of the pair of claw members constituting the hand enters between the rows of the crucibles C adjacent to each other, it was necessary to leave a certain gap so that the claw member would not physically interfere with the crucible C at this time. In this case, as shown in FIG. 3, when using the conventional hand 56 having a structure in which two rod-shaped portions are rotatably connected to each other at their end portions, the form when not holding the crucible C is such that the claw members do not interfere with the crucible C held at the position closest to the end portions as indicated by the dashed-dotted line. Thus, it was necessary to ensure a large gap between the rows of the crucibles C adjacent in the running direction of the belt conveyor in consideration of the form when the claw members are not holding the crucible C. As a result, it was not possible to place a plurality of crucibles C at a high density on the placement surface of the belt conveyor.

[0025] On the other hand, as described above, the hand 6 of the first embodiment of the present invention can maintain the state in which the movable part 20 remains separated from the base part 10 in either the form when holding the crucible C or the form when opening the crucible C. Therefore, compared with the case of using the conventional hand 56 in FIG. 3, it is not necessary to ensure a large gap between the rows of the crucibles C adjacent in the running direction of the belt conveyor. That is, as shown in FIG. 2, when the longitudinal directions of the base part 10 and the movable part 20 are in a positional relationship substantially parallel to each other, by appropriately adjusting the separation distance between the base part 10 and the movable part 20, that is, the length by which the support part 11 protrudes from the base part 10, so that a plurality of crucibles C can be simultaneously held by the opposing tip contact parts thereof, the form of the hand 6 can be changed from the form when holding the crucible C to the form when not holding the crucible C only by slightly rotating the movable part 20 with respect to the base part 10 and moving the tip contact part of the movable part 20 in a direction away from the tip contact part of the base part 10.

[0026] As described above, compared with the conventional hand 56 shown in FIG. 3, the hand 6 of the first embodiment of the present invention does not need to widely open the two claw members before and after clamping the crucible C. Therefore, when placing a plurality of crucibles C on the placement surface of the belt conveyor with the longitudinal direction of the hand 6 oriented parallel to the width direction of the belt conveyor, the interval between the rows of other crucibles C adjacent to the running direction of the belt conveyor can be made narrower than in the case of using the conventional hand 56. Further, the hand 6 of the first embodiment of the present invention can clamp the crucible C without physically interfering with the rows of other adjacent crucibles C even when the interval between the rows of adjacent crucibles C is narrow in the running direction of the belt conveyor compared with the case of using the conventional hand 56. Thus, the placement density of the crucibles C on the placement surface can be increased.

[0027] Note that it is preferable that the distance between the tip contact portion of the movable portion 20 and the portion supported by the support portion 11 is as short as possible. The reason is that since the tip contact portion of the movable portion 20 rotates around the portion supported by the support portion 11, the turning radius can be reduced by shortening the above distance, so that the displacement of the tip contact portion can be made smaller. Also, depending on the specifications of the reciprocating means 12, it may be difficult to reduce the stroke when the rod 13 advances and retracts. Even in such a case, in many cases, it becomes possible to cope by shortening the distance between the portion supported by the support portion 11 and the tip contact portion as described above.

[0028] Next, the hand 106 of the second embodiment of the present invention will be described with reference to FIG. 4. The hand 106 shown in this FIG. 4 is composed of a single rod-shaped member for the base 110, similar to the hand 10 of the first embodiment, but the movable part 120 is composed of a plurality of substantially strip-shaped plate bodies 120a to 120c stacked in the thickness direction. The lengths from the portion supported by the support portion 111 protruding from the substantially central portion of the base 110 to the tip contact portions of these plate bodies are all different. Thus, the plate bodies 120a to 120c are each configured to sandwich one crucible C in cooperation with the tip contact portion of the base 110.

[0029] Furthermore, the base 110 is provided with three reciprocating means 112a to 112c at the end portion on the opposite side of the tip contact portion in the longitudinal direction thereof, and the rods 113a to 113c are respectively configured to protrude and retract in the direction in which the support portion 111 protrudes from these reciprocating means 112a to 112c. The end portions of the three plate bodies 120a to 120c are rotatably connected to the tip end portions of these rods 113a to 113c. Thus, since these plate bodies 120a to 120c can be rotated independently, it becomes possible for each plate body to sandwich or release one crucible C in cooperation with the base 110 at its tip contact portion.

[0030] As described above, the hand 106 of the second embodiment of the present invention can hold one crucible C in cooperation with each of the plurality of plate-like bodies 120a to 120c and the base 110, so that it can be securely held even if the size of the crucible C varies. That is, the crucible C is likely to have variations in thermal deformation due to repeated application of thermal stress caused by heating and cooling, and commercially available crucibles C originally have variations in outer diameter due to outer diameter tolerances within an allowable range. However, as described above, each plate-like body can hold or release one crucible C in cooperation with the base 110, so that the crucible C can be securely held. Therefore, even when the hand 106 is rotated about the longitudinal direction of the base 110 as the central axis while the crucible C is held to tilt the crucible C in order to discharge the molten sample in the crucible C, it is possible to prevent these crucibles C from falling off. Further, by using the hand 106 of the second embodiment of the present invention, it is possible to always hold a portion at the same height from the bottom surface on the side wall surface of the crucible C, so that the molten sample discharged by tilting the crucible C can be stably poured into the mold at the discharge destination.

[0031] Furthermore, the hand 106 of the second embodiment of the present invention can increase the degree of freedom in the form when holding or releasing the crucible C. That is, in the case of the hand 6 of the first embodiment of the present invention, when holding a plurality of crucibles C as shown in FIG. 2, the extending direction of the base 10 and the extending direction of the movable part 20 are parallel to each other. However, in the case of the hand 106 of the second embodiment of the present invention, when holding a plurality of crucibles C, the extending direction of the base 110 and the extending direction of the movable part 120 may be substantially parallel to each other, as shown in FIG. 5(a) when holding a plurality of crucibles C, or as shown in FIG. 6(b) when releasing a plurality of crucibles C.

[0032] 4. Method for Handling Crucible Using Hand Next, regarding the method for handling a crucible using the hand of the present invention described above, the case where the hand is in the second embodiment will be described with reference to FIG. 7 as an example. First, by operating the robot arm device 31, three crucibles C are clamped and lifted from the crucible C accommodated in a container (not shown) using the hand 106 attached to the tip thereof, and taken out from the container.

[0033] Next, by operating the robot arm device 31 while holding the three crucibles C in the above-described state, the crucibles C are placed on the pre-loading crucible placement position 32a of the belt conveyor 32 in a posture such that the extending direction of the base portion 110 is substantially parallel to the width direction of the belt conveyor 32. At this time, in order to increase the placement density by placing as many crucibles C as possible on the placement surface of the belt conveyor 32 to enhance the processing capacity of the melting furnace 33, it is preferable to bring the base portion 110 as close as possible to the row of crucibles C already placed at a position immediately downstream in the running direction of the belt conveyor 32. However, since it is necessary to lift the crucible C waiting on the placement surface of the belt conveyor with the hand 106 after the melting process, the interval between the rows of adjacent crucibles C in the running direction of the belt conveyor needs to be widened to some extent as described later.

[0034] That is, as shown by the dashed-dotted line, when lifting the three crucibles C waiting side by side in the width direction of the belt conveyor 32 at the post-exit crucible waiting position 32b of the belt conveyor 32 with the hand 106, it is necessary to change from a form in which the movable part 120 of the hand 106 is inserted between the rows of adjacent crucibles C in the running direction of the belt conveyor 32 and the crucibles C are not clamped to a form in which the crucibles C are clamped. Therefore, it is necessary to provide an interval that does not interfere with other crucibles C on the upstream side. In this case, as described above, for the hand 106 of the second embodiment of the present invention, it is only necessary to slightly rotate the movable part 120 with respect to the base portion 110. Therefore, it is only necessary to provide an interval between the rows of adjacent crucibles C in the running direction of the belt conveyor 32 by the space in which the movable part 120 rotates. Therefore, the placement density of the crucibles C on the placement surface of the belt conveyor 32 can be increased compared to the case of using the conventional hand shown in FIG. 3.

[0035] After placing the crucible C by lowering the hand 106 to a predetermined position on the pre-loading crucible placement position 32a of the belt conveyor 32 determined as described above, the reciprocating means 112 is operated to change from the clamped state to the released state. As a result, the placement of the crucible C on the placement surface of the belt conveyor 32 is completed. In this way, the crucibles C arranged in a single row in the width direction on the placement surface of the belt conveyor 32 are loaded into the melting furnace 33 by the continuous or intermittent running of the conveyor belt 32, and the sample placed in the crucible C is melted by being heated at a predetermined temperature. The crucible C containing the melted sample exits from the outlet of the melting furnace 33 by the continuous or intermittent running of the conveyor belt 32, and is conveyed to the post-exit crucible standby position 32b after exiting.

[0036] When clamping the crucible C waiting at the post-exit crucible standby position 32b, the robot arm device 31 is operated to insert the movable part 120 into the gap between the row of the crucible C to be clamped and the row of the crucible C placed on the upstream side in the running direction of the belt conveyor. At this time, since the gap between these rows of crucibles C is considered to be an appropriate interval when placing the crucible C as described above, there is no physical interference. After clamping the crucible C in this way and operating the robot arm device 31 to lift it, it is moved to a mold (not shown), and by rotating the hand 106 around the longitudinal direction of the base 110 here, the melted sample in the crucible C can be poured into the mold.

[0037] As described above, the hand of the present invention and the method for handling a crucible using the same have been described based on the first and second embodiments. However, the present invention is not limited to these first and second embodiments, and various modifications and alternative examples can be included without departing from the spirit of the present invention. That is, the scope of the rights of the present invention extends to the scope of the claims and their equivalents.

Description of Reference Numerals

[0038] 1 Base part 2 Swivel part 3 Vertical link part 4 Horizontal link part 5 Wrist part 6, 106 Hand 10, 110 Base part 11, 111 Support part 11a Round bar 12, 112a~112c Reciprocating means 13, 113a~113c Rod 20, 120a~120c Movable part 31 Robot arm device 32 Belt conveyor 32a Pre-loading crucible placement position 32b Post-withdrawal crucible standby position 33 Melting furnace A1, A2, A3, A4, A5, A6 Rotation axis C Crucible

Claims

1. A hand comprising a rod-shaped base and a rod-shaped movable part that are attached to the tip of a robot arm device and are spaced apart from each other, and that sandwich a container from both sides with their opposing tip contact parts, wherein the movable part is rotatably supported at its substantially central part by a support part protruding from the substantially central part of the base, and a reciprocating means provided at the end part of the base on the side opposite to the tip contact part causes a rod that protrudes and retracts in the protruding direction of the support part to rotatably connect the end part of the movable part on the side opposite to the tip contact part, the movable part is composed of a plurality of plate-like bodies stacked in the thickness direction, and their lengths from the part supported by the support part to the tip contact part are all different, and each of the plurality of plate-like bodies is a hand that sandwiches one container in cooperation with the base.

2. The hand according to claim 1, wherein the movable part extends substantially parallel to the base when not holding the container, or extends substantially parallel to the base when holding the container.

3. The hand according to claim 1 or 2, wherein the reciprocating means is an air cylinder.

4. A method for handling a crucible using the hand according to any one of claims 1 to 3, attached to the tip of a single robot arm device, wherein, among the placement surfaces of a conveying means that continuously or intermittently conveys a plurality of crucibles and sequentially loads them into a heating furnace, one or more crucibles containing the content before heating are placed one by one at a position upstream of the loading port of the heating furnace; and a step of alternately repeating a step of lifting one or more crucibles containing the content after heating, which are waiting at a position downstream of the discharge port of the heating furnace, and discharging the content.

Images