JP7523651B1 - Melting device and melting method - Google Patents

Abstract

[Problem] To provide a melting device and a melting method capable of suppressing a drop in the temperature of a molten material. [Solution] In the melting device 1, a crucible 4 can be inserted into and removed from the inside of a container 2. An electric heating wire 3 is provided inside the container 2. When a metal laminate 10 is contained in the crucible 4, the metal laminate 10 is placed on the upper surface of the bottom 4a of the crucible 4. The metal laminate 10 contained in the crucible 4 is melted by the heating wire 3 generating heat with the bottom 4a of the crucible 4 placed on the heating wire 3. [Selected Figure] Figure 1

Description

This disclosure relates to a melting device and a melting method for melting solid objects.

Patent Document 1 discloses a method for processing a wire rope end socket, in which molten casting metal is poured into a socket into which the end of the rope is inserted, to fix the socket to the end of the wire rope. The casting metal is melted in a tank. The molten casting metal is scooped up from the tank with a ladle and poured into the socket.

JP 2006-241652 A

However, in the conventional method of processing sockets at the ends of wire ropes disclosed in Patent Document 1, molten cast metal is poured into the socket in a tank using a ladle. This causes the temperature of the cast metal to drop when it is poured into the socket. This can result in a decrease in the fixing strength of the socket to the end of the wire rope.

The present disclosure aims to solve the above problems and provide a melting device and a melting method that can suppress a decrease in the temperature of the molten material.

The melting apparatus of the present disclosure comprises a container, an electric heating wire provided inside the container, and a crucible that can be inserted and removed from inside the container and can contain a solid object. When the solid object is contained in the crucible, the solid object is placed on the upper surface of the bottom of the crucible, and the solid object contained in the crucible is melted by the heat generated by the electric heating wire when the bottom of the crucible is placed on the electric heating wire.
In addition, the melting method according to the present disclosure includes a preparation step of placing a crucible containing a solid object inside a container, a heating step of melting the solid object into a molten material by generating heat from an electric heating wire provided inside the container after the preparation step, and an injection step of removing the crucible from inside the container after the heating step and injecting the molten material from the crucible into an object to be injected, and in the preparation step, the solid object is placed on top of the bottom of the crucible, and the crucible is placed inside the container with the bottom of the crucible resting on the electric heating wire.

The melting device and melting method disclosed herein can suppress a decrease in the temperature of the molten material.

1 is a cross-sectional view showing a melting device according to a first embodiment. 2 is a cross-sectional view showing a state in which the metal laminate of FIG. 1 has melted into molten metal. FIG. 2 is a flowchart showing a melting method using the melting device 1 of FIG. 1 . FIG. 11 is a cross-sectional view showing a melting device according to a second embodiment.

The following describes the embodiments for implementing the subject matter of this disclosure with reference to the attached drawings. In each drawing, identical or corresponding parts are given the same reference numerals, and duplicated descriptions are appropriately simplified or omitted. Note that the subject matter of this disclosure is not limited to the following embodiments, and any of the components of the embodiments may be modified or omitted without departing from the spirit of this disclosure.

Embodiment 1.
1 is a cross-sectional view showing a melting apparatus according to embodiment 1. In the figure, the melting apparatus 1 has a container 2, a heating wire 3, a crucible 4, a thermometer 5, and a stopper 6.

The container 2 has a container body 21 and a lid 22. An opening 23 is formed in the container body 21. The container body 21 is positioned with the opening 23 facing upward.

The lid 22 is removably attached to the container body 21. When the lid 22 is attached to the container body 21, the opening 23 is closed by the lid 22. The opening 23 opens when the lid 22 is removed from the container body 21.

The lid 22 is provided with a through hole 24. The through hole 24 penetrates the lid 22 along the thickness direction of the lid 22. As a result, when the container body 21 with the lid 22 attached is positioned with the opening 23 facing upward, the direction along the through hole 24 coincides with the up-down direction.

The heating wire 3 is provided inside the container body 21. The heating wire 3 is fixed to the bottom of the container body 21 via a molding material 25. The molding material 25 is laid inside the container body 21 along the bottom surface of the container body 21 as a heat insulating material.

The heating wire 3 is provided along the upper surface of the molding material 25. In this embodiment, when the inside of the container body 21 is viewed from the opening 23, the heating wire 3 is arranged in a spiral shape. In a cross section perpendicular to the longitudinal direction of the heating wire 3, the lower part of the heating wire 3 is fixed to the molding material 25, and the upper part of the heating wire 3 is exposed to the space inside the container 2.

The heating wire 3 generates heat when electricity is supplied to the heating wire 3. The amount of heat generated by the heating wire 3 varies depending on the amount of electricity supplied to the heating wire 3. The amount of electricity supplied to the heating wire 3 is controlled by a control unit (not shown). As a result, the amount of heat generated by the heating wire 3 is adjusted by the control of the control unit.

The crucible 4 can be inserted and removed from the inside of the container body 21 through the opening 23. This allows the crucible 4 to be inserted and removed from the inside of the container 2.

The crucible 4 is a heat-resistant container with an open top. In this embodiment, a metal heat-resistant container is used as the crucible 4. The bottom 4a of the crucible 4 has a flat plate shape. The bottom 4a of the crucible 4 is placed on the heating wire 3 inside the container 2.

The crucible 4 is capable of containing a solid object. The solid object is a raw material in a solid state before being melted by the melting device 1. The solid object is melted by heating to become a molten material in a liquid state. The molten material obtained from the solid object is injected into an object to be injected and solidifies, and is used as a part or component of a manufactured product. Examples of materials for the solid object include metal and glass.

In this embodiment, a metal in a solid state is used as the solid object. Specifically, a metal laminate 10 made of multiple metal plates made of Babbitt metal is used as the solid object. Therefore, in this embodiment, the molten metal obtained by melting the metal laminate 10 is a molten material obtained from a solid object. In this embodiment, molten metal is injected into the socket in order to fix the socket to the end of the elevator rope. Therefore, in this embodiment, the socket is used as the object to be injected. In this embodiment, the end of the elevator rope is inserted into the socket, and then the molten metal is injected into the socket and solidifies, thereby fixing the socket to the end of the rope.

The metal laminate 10 contained in the crucible 4 is placed on the top surface of the bottom 4a of the crucible 4. When the metal laminate 10 is contained in the crucible 4 and the bottom 4a of the crucible 4 is placed on the heating wire 3, if the heating wire 3 generates heat, heat is conducted from the heating wire 3 to the metal laminate 10 via the bottom 4a of the crucible 4. Therefore, the metal laminate 10 contained in the crucible 4 melts when the heating wire 3 generates heat with the bottom 4a of the crucible 4 placed on the heating wire 3. When the metal laminate 10 contained in the crucible 4 melts, molten metal accumulates inside the crucible 4 as a molten material.

The thermometer 5 has a rod-shaped portion 51 and a temperature-sensing portion 52. The thermometer 5 is also electrically connected to the control unit via a cable 53.

The temperature sensing part 52 is provided at one end of the rod-shaped part 51. A cable 53 is attached to the other end of the rod-shaped part 51. The cable 53 is electrically connected to the temperature sensing part 52. The thermometer 5 is placed on the lid 22 with the rod-shaped part 5 passing through the through hole 24 and the temperature sensing part 52 being placed inside the container 2. The cable 53 is attached to the rod-shaped part 51 outside the container 2.

The temperature sensor 52 detects the temperature at the position of the temperature sensor 52. The temperature sensor 52 also generates a signal corresponding to the temperature at the position of the temperature sensor 52. In this embodiment, the temperature sensor 52 is a thermocouple. The signal from the temperature sensor 52 is sent to the control unit via the cable 53. The control unit controls the amount of power supplied to the heating wire 3 based on the signal from the temperature sensor 52 to adjust the amount of heat generated by the heating wire 3.

The rod-shaped portion 51 can slide through the through hole 24 along the thickness direction of the lid 22. This allows the temperature sensing portion 52 to move vertically relative to the container 2 together with the rod-shaped portion 51. In other words, the thermometer 5 can move vertically relative to the container 2.

The stopper 6 is a separate member from the thermometer 5. The stopper 6 is attached to the thermometer 5 outside the container 2. In this embodiment, the stopper 6 is attached to the rod-shaped portion 51 at a position above the container 2.

The stopper 6 is attached to the rod-shaped portion 51 by a screw 61 that serves as a fastener. The stopper 6 can slide along the rod-shaped portion 51 by loosening the screw 61. This makes it possible to adjust the position of the stopper 6 relative to the thermometer 5 in the longitudinal direction of the rod-shaped portion 51 by loosening the screw 61. Therefore, the distance from the temperature-sensing portion 52 to the stopper 6 can be adjusted by loosening the screw 61.

The weight of both the thermometer 5 and the stopper 6 are applied downward to the thermometer 5. This allows the thermometer 5 to move downward relative to the container 2 due to the weight of the thermometer 5 and the weight of the stopper 6.

The stopper 6 engages with the lid 22 of the container 2 to prevent the thermometer 5 from moving downward. When the stopper 6 is engaged with the lid 22, the temperature-sensing part 52 is located at a reference position A set inside the container 2. As a result, the stopper 6 prevents the temperature-sensing part 52 from moving downward below the reference position A.

When the metal laminate 10 is contained in the crucible 4 and the bottom 4a of the crucible 4 is placed on the heating wire 3, the bottom 4a of the crucible 4 is located below the reference position A, and the temperature-sensing part 52 is placed on the metal laminate 10 placed on the top surface of the bottom 4a of the crucible 4. When the temperature-sensing part 52 is placed on the metal laminate 10, the thermometer 5 is supported by the metal laminate 10, so that the stopper 6 is kept at a position above and away from the lid 22 of the container 2. As a result, when the temperature-sensing part 52 is placed on the metal laminate 10, the position of the temperature-sensing part 52 is above the reference position A.

Figure 2 is a cross-sectional view showing the state in which the metal laminate 10 in Figure 1 has melted to become molten metal. When the metal laminate 10 melts to become molten metal 20 in a liquid state, the molten metal 20 accumulates inside the crucible 4. As a result, the metal laminate 10 no longer supports the thermometer 5, and the thermometer 5 moves downward relative to the container 2 until the stopper 6 engages with the lid 22 of the container 2.

The stopper 6 holds the temperature-sensing part 52 at the reference position A by engaging with the lid 22 of the container 2, and prevents the temperature-sensing part 52 from moving below the reference position A. Therefore, when the molten metal 20 is accumulating inside the crucible 4, the stopper 6 prevents the temperature-sensing part 52 from moving below the reference position A. This prevents the temperature-sensing part 52 from coming into contact with the bottom 4a of the crucible 4 when the molten metal 20 is accumulating inside the crucible 4.

The liquid level of the molten metal 20 stored inside the crucible 4 is located above the reference position A. Therefore, when the molten metal 20 is stored inside the crucible 4, the temperature-sensing part 52 is buried in the molten metal 20. The volume of the metal laminate 10 is adjusted before melting the metal laminate 10 so that the liquid level of the molten metal 20 is located above the reference position A.

Next, a melting method for melting the metal laminate 10 using the melting device 1 will be described. FIG. 3 is a flow chart showing the melting method using the melting device 1 of FIG. 1. The melting method using the melting device 1 includes a preparation step S1, a heating step S2, and an injection step S3. In the melting method using the melting device 1, each step is carried out in the order of the preparation step S1, the heating step S2, and the injection step S3.

<Preparation step S1>
When the metal laminate 10 is melted by the melting device 1, a preparation step S1 is first performed. In the preparation step S1, the crucible 4 containing the metal laminate 10 is placed inside the container 2. Specifically, in the preparation step S1, the metal laminate 10 is placed on the upper surface of the bottom 4a of the crucible 4, and then the crucible 4 is placed inside the container body 21 through the opening 23. Inside the container body 21, the bottom 4a of the crucible 4 is placed on the heating wire 3 so that the bottom 4a of the crucible 4 is located below the reference position A. After this, the lid 22 is attached to the container body 21 and the opening 23 is closed by the lid 22. In this way, in the preparation step S1, the metal laminate 10 is placed on the upper surface of the bottom 4a of the crucible 4, and the crucible 4 is placed inside the container 2 with the bottom 4a of the crucible 4 placed on the heating wire 3.

After this, in the preparation step S1, the thermometer 5 is inserted into the through hole 24, and the temperature-sensing part 52 is placed on the metal laminate 10 inside the container 2. At this time, the position of the stopper 6 is held at a position above and away from the lid 22. Therefore, the position of the temperature-sensing part 52 at this time is higher than the reference position A.

<Heating step S2>
After the preparation step S1, a heating step S2 is carried out. In the heating step S2, the heating wire 3 is heated by supplying electricity to the heating wire 3. At this time, the control unit controls the amount of electricity supplied to the heating wire 3 based on a signal from the temperature sensor 52, and adjusts the amount of heat generated by the heating wire 3. As a result, the metal laminate 10 melts to become molten metal 20, and the molten metal 20 accumulates inside the crucible 4. The control unit controls the amount of electricity supplied to the heating wire 3 so that the temperature of the molten metal 20 is maintained at a set temperature.

When the metal laminate 10 melts, the weight of the thermometer 5 and the weight of the stopper 6 cause the thermometer 5 to move downward relative to the container 2 in response to the deformation of the metal laminate 10 that accompanies the melting of the metal laminate 10. After this, when the temperature-sensing part 52 reaches the reference position A, the stopper 6 engages with the lid 22 of the container 2. As a result, the stopper 6 prevents the temperature-sensing part 52 from moving downward below the reference position A. At this time, the temperature-sensing part 52 is buried in the molten metal 20 while separated from the bottom 4a of the crucible 4. As a result, the temperature-sensing part 52 comes into contact with the molten metal 20 to detect the temperature of the molten metal 20 and generate a signal corresponding to the temperature of the molten metal 20.

<Injection step S3>
After the heating step S2, the pouring step S3 is carried out. In the pouring step S3, the crucible 4 in which the molten metal 20 is stored is removed from the inside of the container 2, and the molten metal 20 is poured from the crucible 4 into the socket, which is the object of pouring. In the pouring step S3, the thermometer 5 is pulled out from the through hole 24, and the lid 22 is removed from the container body 21. At this time, the lid 22 may be removed from the container body 21 together with the thermometer 5. Thereafter, the crucible 4 is removed from the inside of the container body 21 through the opening 23 by a holder such as crucible tongs, and then the molten metal 20 is poured from the crucible 4 into the socket into which the end of the rope is inserted. Thereafter, the molten metal 20 solidifies in the socket, thereby fixing the socket to the end of the rope.

In such a melting device 1, the crucible 4 capable of containing the metal laminate 10 can be inserted and removed from inside the container 2. Therefore, the molten metal 20 obtained by melting the metal laminate 10 can be removed from inside the container 2 together with the crucible 4. This eliminates the need to transfer the molten metal 20 from the crucible 4 to another container, and the molten metal 20 can be directly injected from the crucible 4 into the socket, which is the object of injection. Therefore, a decrease in the temperature of the molten metal 20 can be suppressed. This makes it possible to suppress the occurrence of problems caused by a decrease in the temperature of the molten metal 20, such as a decrease in the fixing strength of the socket to the end of the rope.

The bottom 4a of the crucible 4 is placed on the heating wire 3. The metal laminate 10 is placed on the upper surface of the bottom 4a of the crucible 4. This makes it easier for the heat generated by the heating wire 3 to be transferred to the metal laminate 10, and the heat generated by the heating wire 3 can be transferred to the metal laminate 10 efficiently. This makes it possible to shorten the melting time of the metal laminate 10.

In addition, when the metal laminate 10 is contained in the crucible 4 and the bottom 4a of the crucible 4 is placed on the heating wire 3, the bottom 4a of the crucible 4 is located below the reference position A, and the temperature-sensing part 52 is placed on the metal laminate 10. Therefore, the temperature-sensing part 52 can be moved downward in accordance with the deformation of the metal laminate 10 caused by the melting of the metal laminate 10 inside the crucible 4. This allows the temperature-sensing part 52 to come into contact with the molten metal 20 even when the metal laminate 10 becomes the molten metal 20. In addition, since the stopper 6 prevents the temperature-sensing part 52 from moving below the reference position A, it is possible to prevent the temperature-sensing part 52 from coming into contact with the bottom 4a of the crucible 4 when the metal laminate 10 becomes the molten metal 20. Therefore, the temperature-sensing part 52 can directly detect the temperature of the molten metal 20, and it is possible to prevent the temperature of the crucible 4 itself from affecting the detection of the temperature of the temperature-sensing part 52. This allows the temperature of the molten metal 20 to be detected more accurately.

The thermometer 5 can be moved downward relative to the container 2 due to the weight of the thermometer 5 and the weight of the stopper 6. Therefore, the stopper 6 can be used as a weight for moving the thermometer 5 downward. This makes it possible to more reliably move the temperature-sensing part 52 downward when the metal laminate 10 melts. Also, it is no longer necessary to attach a weight to the thermometer 5 in addition to the stopper 6 in order to move the thermometer 5 downward relative to the container 2. This makes it possible to prevent an increase in the number of parts.

The position of the stopper 6 relative to the thermometer 5 can be adjusted in the longitudinal direction of the rod-shaped portion 51 of the thermometer 5. Therefore, by adjusting the position of the stopper 6 relative to the thermometer 5, the reference position A inside the container 2 can be adjusted. This allows the reference position A to be set according to the size of the metal laminate 10. Therefore, when the metal laminate 10 becomes the molten metal 20, it is possible to prevent the position of the liquid surface of the molten metal 20 from being lower than the reference position A. This allows the temperature-sensing portion 52 held at the reference position A by the stopper 6 to be more reliably brought into contact with the molten metal 20, and the temperature of the molten metal 20 to be detected more accurately.

In addition, in a cross section perpendicular to the longitudinal direction of the heating wire 3, the lower part of the heating wire 3 is fixed to the molding material 25, and the upper part of the heating wire 3 is exposed to the space inside the container 2. This allows the heat generated by the heating wire 3 to be transferred to the metal laminate 10 more efficiently. This further shortens the melting time of the metal laminate 10.

In addition, in this melting method, after the heating step S2, in the injection step S3, the crucible 4 containing the molten metal 20 is removed from the inside of the container 2, and the molten metal 20 is injected from the crucible 4 into the socket, which is the object to be injected. This eliminates the need to transfer the molten metal 20 from the crucible 4 to another container, and the molten metal 20 can be injected directly from the crucible 4 into the socket, which is the object to be injected. This makes it possible to suppress a decrease in the temperature of the molten metal 20.

In addition, in the preparation step S1, the metal laminate 10 is placed on the top surface of the bottom 4a of the crucible 4, and the crucible 4 is placed inside the container 2 with the bottom 4a of the crucible 4 resting on the heating wire 3. This makes it easier for the heat generated by the heating wire 3 to be transferred to the metal laminate 10, and the heat generated by the heating wire 3 can be transferred efficiently to the metal laminate 10. This makes it possible to shorten the melting time of the metal laminate 10.

In addition, in the preparation step S1, the bottom 4a of the crucible 4 is placed on the heating wire 3 so that the bottom 4a of the crucible 4 is located below the reference position A, and the temperature-sensing part 52 is placed on the metal laminate 10 inside the container 2. In the heating step S2, when the temperature-sensing part 52 reaches the reference position A following the deformation of the metal laminate 10 caused by the melting of the metal laminate 10, the movement of the temperature-sensing part 52 below the reference position A is prevented by the stopper 6. Therefore, when the metal laminate 10 becomes the molten metal 20, it is possible to prevent the temperature-sensing part 52 from coming into contact with the bottom 4a of the crucible 4. Therefore, the temperature-sensing part 52 can directly detect the temperature of the molten metal 20, and the temperature of the molten metal 20 can be detected more accurately.

Embodiment 2.
4 is a cross-sectional view showing a melting apparatus according to embodiment 2. The melting apparatus 1 has a container 2, a heating wire 3, a crucible 4, a thermometer 5, a stopper 6, and a protective sheet 7.

The protective sheet 7 can be inserted and removed from inside the container 2. The protective sheet 7 covers the heating wire 3 inside the container 2. The protective sheet 7 is a heat-resistant and heat-conductive sheet. For example, a ceramic sheet is used as the protective sheet 7. The bottom 4a of the crucible 4 is placed on the heating wire 3 via the protective sheet 7. The other configuration is the same as in embodiment 1.

In the melting method in this embodiment, only the preparation step S1 is different from the first embodiment. In the preparation step S1, before the crucible 4 is placed inside the container body 21, the protective sheet 7 is placed inside the container body 21 through the opening 23. At this time, inside the container body 21, the heating wire 3 is covered with the protective sheet 7.

In the preparation step S1, the crucible 4 containing the metal laminate 10 is placed inside the container body 21 with the protective sheet 7 covering the heating wire 3. At this time, inside the container body 21, the bottom 4a of the crucible 4 is placed on the heating wire 3 with the protective sheet 7 in between. The other steps are the same as in embodiment 1.

In such a melting device 1, the bottom 4a of the crucible 4 is placed on the heating wire 3 via the protective sheet 7. Therefore, the heating wire 3 can be protected by the protective sheet 7. For example, even if the molten metal 20 accumulated inside the crucible 4 spills from the crucible 4, the protective sheet 7 can prevent the molten metal 20 from contacting the heating wire 3. This can suppress damage to the heating wire 3. In addition, when the bottom 4a of the crucible 4 is placed on the heating wire 3, the protective sheet 7 can prevent the bottom 4a of the crucible 4 from contacting the heating wire 3. This can further suppress damage to the heating wire 3 and also suppress damage to the crucible 4. Furthermore, for example, if the protective sheet 7 becomes dirty or damaged, the protective sheet 7 can be easily replaced.

In each of the above embodiments, the weight of the thermometer 5 and the weight of the stopper 6 allow the thermometer 5 to move downward relative to the container 2. However, the weight of the stopper 6 does not have to be added to the thermometer 5. In other words, the thermometer 5 may be able to move downward relative to the container 2 only due to the weight of the thermometer 5.

For example, a hanging device for hanging the thermometer 5 may be provided in the container 2 as a stopper. In this case, the hanging device as a stopper has a fixed column fixed to the lid 22 of the container 2, a support beam fixed to the upper part of the fixed column, and a string for hanging the thermometer 5 from the support beam. In this case, when the temperature-sensing part 52 is placed on the metal laminate 10, the string of the hanging device loosens. Furthermore, in this case, when the metal laminate 10 melts and becomes the molten metal 20, the thermometer 5 moves downward and is suspended by the string. Even in this way, the hanging device as a stopper can prevent the temperature-sensing part 52 from moving downward beyond the reference position A, and the temperature-sensing part 52 can be prevented from contacting the bottom 4a of the crucible 4. Therefore, it is sufficient that the thermometer 5 is movable downward with respect to the container 2 at least by the weight of the thermometer 5.

In addition, in each of the above embodiments, one stopper 6 is attached to the rod-shaped portion 51 of the thermometer 5. However, a stopper other than the stopper 6 may be attached to the rod-shaped portion 51 as a second stopper. In this case, the second stopper is disposed at a position farther from the temperature sensing portion 52 in the longitudinal direction of the rod-shaped portion 51 than the stopper 6, which is the first stopper. In other words, the second stopper is disposed at a position closer to the cable 53 in the longitudinal direction of the rod-shaped portion 51 than the stopper 6. In this case, the second stopper is also attached to the rod-shaped portion 51 by a screw as a fastener, similar to the stopper 6.

In this way, even if the screw 61 of the stopper 6 becomes loose and the position of the stopper 6 is unintentionally shifted relative to the rod-shaped portion 51, the second stopper can be made to engage with the lid 22 of the container 2 via the stopper 6 when the metal laminate 10 melts. The distance from the temperature-sensing portion 52 to the second stopper is adjusted to a distance that keeps the temperature-sensing portion 52 away from the bottom 4a of the crucible 4 when the second stopper engages with the lid 22 of the container 2 via the stopper 6. This makes it possible to more reliably prevent the temperature-sensing portion 52 from coming into contact with the bottom 4a of the crucible 4 when the metal laminate 10 melts, and to more accurately detect the temperature of the molten metal 20.

In addition, in each of the above embodiments, the control unit may have an abnormality determination unit that determines whether or not there is an abnormality in the state of the thermometer 5 based on the temperature detected by the temperature sensing unit 52. In this case, a threshold value for comparison with the temperature detected by the temperature sensing unit 52 is set in the abnormality determination unit. In this case, the abnormality determination unit determines whether or not there is an abnormality in the state of the thermometer 5 by comparing the temperature detected by the temperature sensing unit 52 with the threshold value.

For example, the abnormality determination unit determines that there is an abnormality in the state of the thermometer 5 when the increase in temperature detected by the temperature sensing unit 52 from the start of energization of the heating wire 3 until a certain time has elapsed is lower than the threshold value. In this way, it is possible to determine that there is an abnormality in the state of the thermometer 5 if the temperature sensing unit 52 stops at a position above the metal laminate 10 at the time when heating of the metal laminate 10 starts. This makes it possible to determine that there is an abnormality in the state of the thermometer 5 at the time when heating of the metal laminate 10 starts. Examples of causes of the temperature sensing unit 52 stopping at a position above the metal laminate 10 include the distance from the temperature sensing unit 52 to the stopper 6 in the longitudinal direction of the rod-shaped unit 51 being too short, or the rod-shaped unit 51 being unable to move relative to the lid 22 of the container 2 due to friction between the rod-shaped unit 51 and the lid 22.

For example, the abnormality determination unit determines that there is an abnormality in the state of the thermometer 5 when the temperature detected by the temperature sensing unit 52 drops continuously while electricity is still being passed through the heating wire 3, and the temperature drop is equal to or greater than a threshold value. In this way, it is possible to determine that there is an abnormality in the state of the thermometer 5 if the temperature sensing unit 52 stops at a position above and away from the metal laminate 10 while the metal laminate 10 is melting. This makes it possible to determine that an abnormality has occurred in the state of the thermometer 5 while the metal laminate 10 is being heated.

In addition, in each of the above embodiments, the thermometer 5 is disposed on the lid 22, and the stopper 6 is attached to the thermometer 5. However, the thermometer 5 and the stopper 6 are not necessary. Even without the thermometer 5 and the stopper 6, the molten metal 20 can be removed from inside the container 2 together with the crucible 4, so that a decrease in the temperature of the molten metal 20 can be suppressed.

In addition, in each of the above embodiments, the socket of an elevator rope is used as the injection object into which the molten material is injected. However, the injection object is not limited to this. For example, a mold into which the molten material is injected to form a casting may be used as the injection object.

In addition, in each of the above embodiments, in the preparation step S1, the thermometer 5 is inserted into the through hole 24 after the lid 22 is attached to the container body 21. However, in the preparation step S1, after the thermometer 5 is inserted into the through hole 24, the lid 22 may be attached to the container body 21 with the thermometer 5 passing through the through hole 24.

The configurations shown in the above embodiments are examples of the contents of this disclosure. The embodiments can be combined with other known technologies. Part of the configuration of the embodiments can be omitted or modified without departing from the gist of this disclosure.

1 melting device, 2 container, 3 heating wire, 4 crucible, 4a bottom, 5 thermometer, 6 stopper, 7 protective sheet, 10 metal laminate (solid), 20 molten metal (molten material), 52 temperature sensor.

Claims (6)

A container;
A heating wire provided inside the container;
a crucible that is removable from the inside of the container and capable of housing a solid object;
When the solid object is contained in the crucible, the solid object is placed on an upper surface of a bottom portion of the crucible;
A melting device in which the solid object contained in the crucible is melted by the heat generated by the heating wire with the bottom of the crucible placed on the heating wire. A protective sheet is provided which is removable from the inside of the container,
2. The melting apparatus according to claim 1, wherein the bottom of the crucible is placed on the heating wire via the protective sheet. A thermometer having a temperature sensing part;
A stopper and
the thermometer is movable downward relative to the container at least by a weight of the thermometer;
The stopper prevents the temperature sensing portion from moving downward beyond a reference position set inside the container,
3. A melting device as described in claim 1 or claim 2, wherein when the solid object is contained in the crucible and the bottom of the crucible is placed on the heating wire, the bottom of the crucible is located lower than the reference position and the temperature-sensing part is placed on the solid object. The stopper is attached to the thermometer,
The melting device according to claim 3 , wherein when the temperature sensing portion is disposed inside the container, the thermometer is movable downward relative to the container due to the weight of the thermometer and the weight of the stopper. a preparation step of placing a crucible containing a solid object inside a vessel;
a heating step of melting the solid material into a molten material by heating an electric heating wire provided inside the container after the preparing step;
and a pouring step of, after the heating step, removing the crucible from inside the container and pouring the molten material from the crucible into an object to be poured,
A melting method in which, in the preparation step, the solid object is placed on the upper surface of the bottom of the crucible, and the crucible is placed inside the container with the bottom of the crucible placed on the heating wire. In the preparation step, the bottom of the crucible is placed on the heating wire so that the bottom of the crucible is located below a reference position set inside the container, and a temperature-sensing part of a thermometer is placed on the solid object;
In the heating step, a heat generation amount of the heating wire is adjusted based on a signal from the temperature sensor,
The melting method according to claim 5, wherein in the heating step, when the thermometer moves downward relative to the container in response to deformation of the solid object due to melting of the solid object and the temperature-sensing part reaches the reference position, movement of the temperature-sensing part downward beyond the reference position is prevented by a stopper.

Images