JPH0445751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is directed to various types of containers, such as crucibles for crucible-type high-frequency induction furnaces, in which solid materials are charged from the top side. This relates to a material pushing device for pushing materials into the bottom part.

BACKGROUND ART Crucible-type high-frequency induction furnaces have traditionally been used for melting various metal materials, and have recently come to be used for remelting aluminum scraps as well.

By the way, in the case of a melting furnace such as a crucible-type high-frequency induction furnace, in which the material to be melted is charged from above into a furnace with an open top surface, the charged melted material flows between the opposing furnace walls at the upper part of the furnace. A condition where the material is stuck in a bridge shape, that is, the so-called "shelf hanging phenomenon" may occur, and the charged molten material may not be immersed in the molten metal in the furnace, and the material may no longer be melted. In particular, when using scrap material (hereinafter referred to as scrap block) made by soft-pressing cutting scraps and other irregularly shaped and sized plate scraps such as aluminum scraps (hereinafter referred to as scrap blocks) as the melting material, the scrap blocks are Since parts of bent chips and elongated boards protrude from the surrounding area, the scrap blocks tend to become entangled with each other, resulting in a shelf-hanging phenomenon. FIG. 4 shows an example of how the shelving phenomenon occurs when waste blocks are used as the melting material. In FIG. 4, 18 is a crucible of a crucible-type high-frequency induction furnace 17, 7 is a scrap block suspended on a shelf, and 19 is a molten metal in the crucible 18.

On the other hand, even when the above-mentioned hanging phenomenon does not occur, the scrap blocks have extremely low bulk specific gravity, so they usually float on the surface of the molten metal in the furnace and are difficult to dissolve into the molten metal. Also, when the waste blocks melt near the hot water surface, a large amount of oxides and nitrides are generated, so there are usually multiple layers of slag floating on the hot water surface, and this also causes the waste blocks to melt. This was a factor that hindered integration. Particularly in a high-frequency induction furnace, waste blocks are heated by eddy currents caused by induced magnetic flux, but it is difficult for these eddy currents to flow through the waste blocks, so melting does not proceed quickly when they are floating on the hot water surface as described above. In addition, the high-frequency induction furnace has a lower molten metal stirring force than the low-frequency induction furnace, and this is also a factor in slowing down the dissolution of molten materials such as scrap blocks floating on the surface of the molten metal.

Additionally, if the shelving phenomenon occurs as described above, localized heat generation occurs in the slag adhesion area near the hot water surface, causing severe damage to the furnace material, which also poses the problem of shortening the lifespan of the furnace material.

In order to solve the above problems, when molten material such as scrap blocks is charged from the top side into a furnace such as a crucible type high frequency induction furnace, it is necessary to push the molten material into the molten metal from above. Just do it.
In the past, this pushing work was generally done by workers using input, but the working environment near the furnace was high and poor, and pushing work required hard labor and had safety issues, so pushing work was not done. Mechanization and automation are strongly desired.

By the way, an induction melting furnace in which melted material is mechanically pushed has already been proposed in Japanese Patent Publication No. 5595/1983. In the induction melting furnace described in this publication, as shown in FIG. a limit switch 5 for pushing down the pushing cylinder 3 by the fluid pressure cylinder 4 and controlling the operation of the cylinder 4 in response to the movement of the pushing cylinder 3;
6.

Problems to be Solved by the Invention In the apparatus described in the above-mentioned Japanese Patent Publication No. 61-5595, when a block of soft-pressed aluminum scraps or the like is used as the melting material, the following problems occur.

In other words, since the scrap blocks are shaped like large dice, when they are charged, the upper surfaces of the many loaded scrap blocks 7 are not uniform and have large irregularities, as shown in FIG. It is occurring. Therefore, the lower surface (pushing surface) 3a of the pushing cylinder 3 is
It is rare for the entire part to be in uniform contact with the charging material,
In reality, a portion of the lower surface 3a often comes into local contact with the waste block 7, as shown in FIG.
When a downward pushing force is applied to the pushing cylinder 3 in this state by the cylinder 4, the lower part of the pushing cylinder 3 tends to tilt as shown by arrow B, and the lower part of the pushing cylinder 3 tends to tilt as shown by arrow B. horizontal direction A
The force of trying to escape is added. However, in the device shown in FIG. 5, the axis of the pushing cylinder 3 is aligned with the cylinder 4.
Since the cylinder 4 itself is fixed, the cylinder 3 cannot escape when pushed in the direction of arrow A, and as a result, an unreasonable force is applied to the cylinder 4, causing the cylinder to collapse. 4, or the rods and connecting parts may bend due to the above-mentioned force, making it difficult to move up and down smoothly. Therefore, in actual operations where complicated lifting and lowering is required repeatedly. However, it cannot operate stably for a long period of time, making it unsuitable for actual operation. In addition,
The above-mentioned device in which the pushing force is applied by a cylinder has a problem that the cylinder etc. have to be increased in size in order to apply a sufficient pushing force.

This invention was made against the background of the above circumstances, and even for charging materials such as scrap blocks,
It is possible to stably push the charge material for a long period of time without applying excessive mechanical force, and this prevents the charge material from melting or slowing down due to shelf-hanging phenomena, etc. It is an object of the present invention to provide a material pushing device which can effectively prevent such problems and which can be made compact in terms of equipment.

Means for Solving the Problems This invention provides a material pushing device for pushing material charged into a container with an open top surface from above. , an arm extending laterally is fixed, and a pushing body for pushing the material into the container is attached to the tip of the arm in a horizontal direction perpendicular to the radial direction of rotation of the arm. It is supported so that it can be raised and lowered through a pinion that rotates about an axis and a rack that meshes with the pinion, and a rotational drive source for raising and lowering is installed on the arm or support to rotate the pinion and raise and lower the pressing body. Furthermore, a swing drive mechanism is connected to the support to rotate the support and swing the arm, and the swing drive mechanism is configured to rotate the arm when a torque is applied to the pressing body in the direction of swinging the arm. It is characterized by being provided with a sliding mechanism that allows turning.

Here, it is desirable to use an air motor as the rotational drive source for lifting and lowering.

Function In the material pushing device of the present invention, when the lifting rotational drive source is activated, the rotational force is converted into a linear motion by the pinion and the rack, and the pressing body is moved up and down. On the other hand, when the swing drive mechanism is activated, the support column rotates around the axis, allowing the arm to swing. That is, the pressing body supported at the tip of the arm can be rotated about the axial center position of the support column. Therefore, for example, in a crucible of a crucible-type high-frequency induction furnace, materials may be charged into a container when the presser is not located above the container (in the retracted position). When the pressing body is raised to its rising end, the arm is rotated to position the pressing body above the container, and the lifting rotary drive source is activated to lower the pressing body. A pressing body can press the charge material in the container and force it into the interior. After pushing the material, the lifting drive source may be operated in the opposite direction to raise the pressing body, and then the swing drive mechanism may be operated to rotate the arm and return the pressing body to the initial position.

In this way, the presser body can be evacuated so that it is not located above the container except when pushing the material, so the presser body does not become an obstacle during material charging and cause restrictions on the charging operation. Furthermore, when the container is a metal melting furnace, various incidental operations such as slag removal operations can be easily performed without the pressing body being an obstacle.

Here, if the charged material is a large piece such as a scrap block, the lower surface of the pressing body, that is, the entire pressing surface will not uniformly contact the charged material, as already explained with reference to FIG. Only a part of it comes into contact with the charging material locally, causing a force that tends to tilt the tip of the pressing body, and a force that tries to escape in the direction of arrow A acts on the pressing body, but this invention In the case of the device, since the swing drive mechanism is provided with a sliding mechanism, the sliding allows the pressing body to escape together with the arm in the direction of its turning. Therefore, out of the force in the direction of arrow A, the force in the sliding direction (arm The force component in the rotation direction) is absorbed by the above-mentioned slip. In addition, since the pinion in the rack-pinion is arranged to rotate around a horizontal axis along a direction perpendicular to the turning radius direction of the arm, the rack tilts slightly with respect to the axis of the pinion. (In other words, even if the pressing body is slightly tilted), the meshing state of the rack and pinion is maintained, so that of the force in the direction of arrow A mentioned above,
The component force in the arm rotation direction can be alleviated by slightly tilting the rack (pressing body).

In this way, by providing a sliding mechanism in the swing drive mechanism and using a rack-pinion to support the lifting and lowering of the pressing body, the uneven force applied to the pressing body when pushing the material is absorbed and alleviated, and the pressing body This prevents excessive force from being applied to the device, its support mechanism, and drive mechanism.

In addition, when the rotary drive source for lifting and lowering is configured with an air motor in particular, the air has a cushioning effect, so that even if there is a large resistance to the lowering of the pressing body, the rotary drive source is not strained. Therefore, failures of the rotary drive source are reduced, and its lifespan can be extended. Furthermore, if an air motor is used as the rotational drive source for lifting and lowering, the pressing force of the pressing body can be easily adjusted.

Embodiment FIGS. 1 to 3 show an embodiment in which the material pushing device of the present invention is applied to a crucible-type high-frequency induction furnace.

In FIG. 1, a vertical support 11 is rotatably supported on a fixed base 10, and an arm 12 extending horizontally to the side is attached to the upper end of the support 11. is installed. A pinion 13 and a rack 1 are attached to the tip of this arm 12.
A pressing body 15 is supported via 4 so as to be movable up and down. That is, the pinion 13 is provided at the tip of the arm 12 so as to be rotatable about a horizontal axis along a direction perpendicular to the turning radius of the arm 12, and a rack 14 that meshes with the pinion 13 is provided at the tip of the arm 12. The rack 14 is supported so as to be movable up and down by a guide member such as a guide roller 16, and a pressing body 15 is attached to the lower part of the rack 14. The pressing body 15 presses from above a melted material charged into a crucible 18 of a crucible-type high-frequency induction furnace 17, for example, a material (waste block) 7 obtained by soft pressing aluminum scraps or the like into a block shape. It is made of a metal material such as stainless steel or a heat-resistant material such as ceramic, and has a lower surface, that is, a material pressing surface 1.
5A is made so that the center part protrudes the most and the circumference is slightly tapered, that is, it forms a conical surface with a large apex angle. Further, the pressing body 15 is attached to the lower end of the ceramic 14 by a pin 20 so as to be easily attachable to and detachable from the lower end.

An air motor 21 is mounted and fixed on the upper surface of the arm 12 as a rotational drive source for raising and lowering the pressing body 15. The rotational drive shaft 21a of this air motor 21 is also connected to the arm 12.
It is connected to an input shaft 22a of a reducer 22 mounted and fixed above, and an output shaft 22b of this reducer 22.
is connected to the pinion 13 via a chain 23. Further, the output shaft 22b of the reducer 22 is
Stroke detection device 2 via another chain 24
It is also connected to 5. This stroke detection device 25 is for detecting the vertical stroke of the pressing body 15, as will be described later.

The support column 11 is rotated about its axis by a rotation drive mechanism 26 connected to its lower part, and the arm 1
It is configured to rotate 2. This swing drive mechanism 26, as schematically shown in FIG.
A motor 27 as a drive source, a reducer 28 connected to the rotational drive shaft of the motor 27, and bevel gears 29, 30 connected to the output shaft of the reducer 28.
, a small sprocket 32 connected via a sliding mechanism 31 connected to a bevel gear 30, and a support column 11.
Large sprocket 33 coaxially fixed at the bottom of
and a chain 34 wound around the small sprocket 32 and the large sprocket 33. Here, the sliding mechanism 31 may be one made of a friction plate or the like to which pressure is applied by a spring or the like, for example, a so-called torque limiter, and in short, the sliding mechanism 31 is on the side of the arm 12 on the driven side and the support column 11. It is sufficient that the structure is such that the arm 12 and the support column 11 are allowed to pivot and rotate when a certain amount of torque in the arm pivot direction is applied.

Operation of the material pushing device of the embodiment as described above,
How to use it is explained below.

First, in the initial state, the pressing body 15 is at the rising end position as shown in FIG. 1, and the arm 12 is at the second position.
It is assumed that it is in the position shown by the imaginary line in the figure, that is, in the retracted position.

From this initial state, the motor 2 of the swing drive mechanism 26
7, the rotational driving force from the motor 27 is applied to the reducer 28, the bevel gears 29, 30, and the sliding mechanism 3.
1. It is transmitted to the column 11 via the small sprocket 32, the chain 34, and the large sprocket 33, and the column 11 rotates around its axis.
turns. Then, as shown by the solid line in FIG.
7 is stopped, and the support column 11 and arm 12 are stopped.

Next, the air motor 21, which serves as a rotational drive source for lifting and lowering, is driven. The rotational driving force of the air motor 21 is transmitted to the pinion 13 via the reducer 22 and the chain 23, and the rack 14 that meshes with the pinion 13 is lowered, and the pressing body 15 at the lower end of the rack 14 is also lowered. Then, as shown by the imaginary line in FIG. 1, the melted material in the crucible 18, for example, the scrap block 7, is pressed and pushed into the molten metal, for example, the molten Al 19. Here, it is assumed that the molten material such as the waste block 7 is charged into the crucible 18 while the pressing body 15 is at the rising end or while it is at the retracted position before that.

When pushing the waste block 7 by the pressure of the pressing body 15 as described above, a part of the lower surface of the pressing body 15 is locally pushed into the scrap block 7 due to the uneven unevenness as described above. The pressing body 15 tries to escape in the horizontal direction due to the force acting on the pressing body 15 in the direction of inclination.
1 is provided, the arm 12 turns by a small angle as shown by the arrow C in FIG. 2 due to the sliding in the sliding mechanism 31, thereby making it possible to cope with the above-mentioned escape. Further, in the embodiment, since the pressing body 15 is attached to the lower end of the rack 14 by the pin 20, the pressing body 15 can be tilted to some extent, and the rack 14 is attached to the pinion 1.
3, the meshing state can be maintained even if it is slightly tilted about its axis. Furthermore, an air motor 21 is used as a rotational drive source for lifting and lowering, and since this air motor 21 has a cushioning effect due to air, when a large resistance is suddenly applied to the downward movement (pressure) of the pressing body 15, There is no need to force yourself. Furthermore, since the air motor 21 is used in this way, the pressing force can be adjusted by the air supply pressure.

By pressing the molten material such as the scrap block 7 with the pressing body 15 as described above, even if the shelving phenomenon occurs, it is eliminated and the molten material is pushed into the molten metal 19 in the crucible 18. The molten material can be quickly dissolved.

Thereafter, the air motor 21 as a rotational drive source for lifting is driven in the opposite direction to raise the pressing body 15, and if necessary, the rotation drive mechanism 26
The arm 12 may be rotated to return to the retracted position.

In the above explanation, since the pressing body 15 has a tapered shape on its lower surface, the molten metal adhering to the material when it is pressed easily flows down.
It can be easily removed and thermal deformation is less likely to occur. Furthermore, since the pressing body 15 is removable, it can be easily replaced if its tip becomes worn out or deformed. Further, since the stroke of the pressing body 15 when moving up and down is detected by the stroke detection device 25 connected to the output shaft 22b of the reducer 22 via the chain 24, the stroke of the pressing body 15 is detected by the stroke detection device 25. 15 raised and lowered positions can be controlled.

Although not specifically shown in the above embodiment, if a load cell is provided below the crucible 18, the actual pressing force when the pressing body 15 presses the material can be detected, and therefore the actual pressing force can be measured. Management can be performed easily. For example, the air motor 21
It is possible to feedback control the air pressure supplied to an appropriate value.

Furthermore, in the embodiment, the air motor 21 as a rotational drive source for lifting and lowering is provided on the arm 12, but it is of course possible to install it on the support column 11.

Furthermore, although the example describes the case where molten material is charged into the crucible of a crucible-type high-frequency induction furnace, other types of melting furnaces and even melting furnaces that require solid material to be charged from above are described. All are applicable to a certain container.

Effects of the Invention According to the material pushing device of the present invention, when charging a large dice-shaped material such as a material (waste block) made by soft pressing aluminum scraps etc. into a block shape, only a part of the lower surface of the pushing body Even if the pinion comes into contact with the material locally and a force is applied to move the pressing body horizontally, the sliding mechanism provided in the swing drive mechanism can correspondingly release the pressing body horizontally. - No unreasonable force is applied to the rack mechanism, etc., and the pinion-rack mechanism itself can tolerate slight inclination of the pressing body. It is possible to prevent the application of force, thereby preventing the occurrence of failure or damage to various parts, and making it possible to sufficiently withstand long-term actual operation. Furthermore, since the material pushing device of the present invention uses an arm rotation system, the pushing body can be retracted at a position horizontally away from the space above the target container such as a crucible while material is not being pushed. Therefore, there are fewer restrictions on operations other than material pushing.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing a material pushing device according to an embodiment of the present invention, Fig. 2 is a plan view of the device shown in Fig. 1, and Fig. 3 is a turning drive used in the device shown in Fig. 1. FIG. 4 is a schematic diagram showing the mechanism, FIG. 4 is a schematic diagram showing the situation in which the shelf hanging phenomenon occurs, FIG. 5 is a schematic front view showing an example of a conventional device, and FIG. 6 is the device shown in FIG. 5. FIG. 7...Scrap block (charged material), 11...Strut, 1
2...Arm, 13...Pinion, 14...Rack, 1
5... Pressing body, 17... High frequency induction furnace, 18... Crucible (container), 19... Molten metal, 21... Air motor (rotary drive source for lifting/lowering), 26... Turning drive mechanism, 31
...sliding mechanism.

Claims (1)

[Scope of Claims] 1. In a material pushing device for pushing material charged into a container with an open top from above, a device is installed on the top of a vertical support rotatably supported around an axis, and is attached to the side thereof. An extending arm is fixedly installed, and a pushing body for pushing the material into the container is attached to the tip of the arm and rotated about a horizontal axis along a direction perpendicular to the radial direction of the rotation of the arm. The arm or support is provided with an elevating rotation drive source for rotating the pinion and elevating the pressing body, and the support is provided with a rotation drive source for elevating and lowering the pressing body by rotating the pinion and a rack that meshes with the pinion. is connected to a swing drive mechanism for rotating this and swinging the arm, and the swing drive mechanism has a sliding mechanism that allows the arm to swing while a torque in the direction of swinging the arm is applied to the pressing body. A material pushing device characterized by being provided with a mechanism. 2. The material pushing device according to claim 1, wherein the lifting rotational drive source is an air motor.