JPH0447600Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a method for quietly placing a large solid charge material as the material to be melted into the melting crucible of a vacuum induction melting furnace without causing any impact to the crucible. This invention relates to a charging material introduction mechanism that allows the material to be inserted into a material.

[Prior Art] As shown in FIG. 4, materials to be melted are introduced into the induction furnace in a vacuum induction melting furnace by suspending a bucket with an openable bottom lid.

In FIG. 4, an induction furnace 11 is arranged in a vacuum tank 13, and a crucible 10 made of a refractory material (which may be composed of a refractory stamp material) is fixed in the center of the furnace. Material to be melted 1
2 is melted by induction heating under low pressure close to vacuum.

Directly above this induction furnace, a gate valve 9 is positioned to shut off or open the atmosphere of the raw material input chamber 1 and the vacuum tank 13.

The bucket 2 for storing materials is attached with a pair of semicircular bottom lids 2c that can be rotated and opened about opposing points or sides of the side walls of the bucket 2. These are suspended from hooks 4 via connectors 2a and 2b using a winch, crane, or the like. A hook 4 is attached to the end of the wire 5, and the wire is wound onto a drum 6 for winding or unwinding. The drum 6 is driven by a motor 7, which raises and lowers the bucket 2. Reference numeral 3 designates a positioning flange that is necessary for the bucket bag to open at the bottom at a predetermined position. Reference numeral 8 designates a fixed stopper provided in the raw material charging chamber 1 and corresponding to the bucket bottom opening flange 3. A method of inputting raw materials according to this conventional technique will be described.

First, the door 1a of the material input chamber 1 is opened to the atmosphere, and materials are put into the bucket 2. Next door 1a
is closed and a vacuum pump (not shown) performs vacuum suction, and when the vacuum tank 13 reaches a predetermined vacuum state, the gate valve 9 is opened and the bucket is lowered.

When the bucket is lowered and reaches a predetermined position directly above the furnace, that is, the position where the charging positioning flange 3 hits the stopper 8, and the bucket is further lowered, the bottom cover 2c is opened on both sides as shown in the figure. , the charge material is freely charged into the furnace by its own weight.

[Problem to be solved by the invention] In the case of such a conventional technique, when the bottom cover is opened as shown in the figure when the crucible is empty, there is a height of H from the opened position to the bottom of the crucible. difference,
In other words, a head difference is created, and the material naturally falls due to gravity from this height, collides with the crucible 10 made of a relatively brittle refractory, and stops.

At this time, if the raw material itself is in the form of large lumps,
Cracks occur in the refractory that makes up the crucible, making the crucible itself unusable. The reason for this is that if such cracks exist, molten metal will penetrate into the furnace wall of the crucible and leak out of the crucible, resulting in a melt leakage accident.

If the material is in the form of fine pellets or powder, it can be operated without worrying about damage due to impact, but when charging bulk material weighing more than 10 kg into the furnace, it is difficult to use conventional technology. However, the object of the present invention is to provide a raw material charging mechanism that can be set gently without applying a strong impact to the refractories when raw materials are charged.

[Means for solving the problem] In the conventional material charging bucket with an opening/closing bottom lid, when the bottom lid is opened, the charging material falls due to its own weight and hits the bottom of the crucible, causing the originally fragile refractory material to fall. In order to solve the problem of damaging the crucible, the present invention uses a slider-crank mechanism, which is a type of link mechanism, and uses a pair of gripping arms, which correspond to connecting arms, to grasp the opposite sides of the charged material. When the lower end of the charge material reaches the lower end of the crucible, the gripping arm opens to release the charge material and allow it to stand still in the crucible.

In addition, in order to add additional charge material when there is already molten metal in the crucible, when the grip arm falls to a predetermined position, the positioning member opens the grip arm and transfers the charge material into the molten metal. The buoyancy of the molten metal, which acts in the opposite direction to the acceleration of the falling charge due to gravity, and the frictional resistance between the molten metal and the charge are used to reduce the falling acceleration of the charge. This allows for additional charging without damaging the crucible.

[Embodiments] Embodiment 1 FIG. 1 shows a first embodiment of a charging material feeding device 10 according to the present invention. Reference numeral 4 in the drawing is a hook for hanging, which is the same as the conventional one.

Reference numeral 12 denotes a charging material, which is a long material such as a round bar, a square bar, or a thick plate.

The charge 12 is held between the pair of gripping arms 16 from opposite sides. 14 is a charging material charging device 10
15 is a vertical guide having a through hole 15a for smoothly guiding the hanging member 14 in the vertical direction.

Reference numeral 16 denotes an arm for gripping the raw material, and the surface in contact with the raw material is made uneven to increase the frictional resistance in the contact state.
The raw material has a non-slip shape.

Reference numeral 17 denotes a pair of opening/closing arms connected to the lower end of the hanging member 14, and by lifting the hanging member 14, both opening/closing arms 17 are opened.
The connecting point between the gripping arm 16 and the gripping arm 16 moves upward, and the pair of gripping arms 16 pivot in the direction of the arrow and approach each other to sandwich the charge material, which is good for reducing the own weight of the material 12 and the frictional force between the gripping shoe 16a. The raw material will be fixed and supported.

Reference numeral 15b indicates a steel pin (a steel ball may be used) that is inserted in the radial direction of the hanging member 14 and is pressed radially outward by a spring, and the position at which the gripping arm opens depends on the thickness and length of the charged material. Since it varies, attach multiple pieces depending on the length of the charging material.

When the position of the hanging member, in which the steel pin 15b is set, escapes outward from the through hole of the vertical guide 15, the steel pin 15b protrudes due to the spring force, as shown in FIG. Member 14
Even if the hanging member 14 is lifted up, the hanging member 14
It becomes impossible to enter further into a.

In such a configuration, the raw material is suspended and moved downward. The charging material descends into the furnace crucible 10
The bottom of the charging material 12 contacts the bottom surface of the charging material 12 . As the descent continues, 16a, which was holding the charge material 12,
is separated from both sides of the charge (double-dashed line in Figure 1),
The steel pin 15b inserted in the predetermined position pops out and the hanging member 14 can no longer be pulled up into the through hole 15a, so the hanging member 14 is pulled up at the opening degree with the charging material released. It will be done.

The spring-pressing steel pin 15b used as a stopper-like member is merely one example, and the present invention is not limited thereto.

Example 2 Charge materials that are square or round in shape, or have relatively uneven surfaces can be lifted by the gripping arm 16 of Example 1, but materials that are highly uneven or tapered can be lifted by the gripping arm 16 of Example 1. In some cases, even if hanging is possible, there is a risk that the device may slip and fall due to frictional engagement with the gripping arm.

FIG. 2 shows the gripping arm 16 of the first embodiment shown in FIG.
In order to make the gripping shoe 16a of the gripping shoe 16a compatible with uneven and complicatedly shaped material surfaces, the gripping shoe at the tip of the gripping arm 16a of the gripping tool 16 is made into an independent member.
16a ₂ , the depth of the recessed hole or groove 21 can be adjusted with the bolt 20, and in order to align it with the surface of the charging material, the 2 is attached to the adjustment fixing plate. I used book bolts to tighten each one. In this way, it is possible to suitably match even the complex surface shape of the charge material, and it can be lifted and suspended safely.

Embodiment 3 The embodiment shown in FIGS. 1 and 2 is a method in which the charging material is lowered to the bottom of the crucible in the induction furnace.

Although such an operation is possible for charging cold material at the start of melting, it cannot be applied to additional material being added during melting, so it is necessary to insert the charge material before it reaches the bottom of the crucible. An embodiment using an adapter that is released from grip will be described with reference to FIG.

The adapter used in this embodiment has an L-shaped fitting 18 removably attached to the vertical guide 15 shown in FIG. 4. When the L-shaped positioning fitting 18 hits the stopper 8 shown in FIG. The raw material separates from the gripping arm 16a at an appropriate position directly above and falls into the molten metal of the induction furnace, but the falling speed is reduced by the buoyancy and frictional resistance from the molten metal, which has approximately the same specific gravity as the charging material. The charge material never hits the bottom of the crucible.

In this way, additional input of material generated during melting is also possible with the invention.

[Effects] As shown in Figures 1, 2, and 3, the effects of the present invention are that damage to the refractories in the induction furnace that occurs when charging material is significantly reduced, and the refractory of the furnace is reduced due to external factors. It can be used stably over a long period of time without causing cracks in objects, and it also improves the reliability of gripping charging materials and is excellent in safety.

[Brief explanation of drawings]

FIG. 1A is a side view showing the first embodiment of the present invention, FIG. 1B is a front view, FIG. 1C is a partially enlarged view showing the state in which the steel pin has escaped from the vertical guide, and FIG. FIG. 3 is a side view showing a second embodiment of the present invention, FIG. 3 is a side view showing a third embodiment of the present invention, and FIG. 4 is a side view showing a conventional device. Code in the drawing: 10...Charging material charging device, 12
... Charge material, 14 ... Hanging member, 15 ... Vertical guide, 15a ... Through hole, 15b ... Steel pin,
16...Gripping arm, 16a...Gripping shoe, 16
a ₁ ...Adjustment fixing plate, 16a ₂ ...Gripping shoe,
17...Opening/closing arm, 18...L-shaped metal fitting, 20...
...Bolt, 21... recessed hole or groove.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a charging material charging device for charging charging material as a material to be melted into a melting crucible of a vacuum induction melting furnace, this charging material charging device alone: Alternatively, a hanging member for connecting the charge charging device that grips the charge material to a hook or the like, a gripping arm that securely grips the charge so that it can be opened, and one side for opening and closing the gripping arm. an opening/closing arm having one end pivotally attached to a substantially central portion of the gripping arm and the other end pivoting below the hanging member;
a vertical guide pivotally attached to the upper end of the gripping arm and having a through hole at its axis for slidably guiding the hanging member; Upon reaching the bottom of the crucible, a slider-crank mechanism opens the gripping arms outward to release the charge, leaving it in the crucible, after which the gripping arms remain open and are lifted up. A charging material feeding device for a vacuum induction melting furnace, which is characterized by: 2. In the charging material charging device according to claim 1,
A gripping shoe in direct contact with the charging material of the gripping arm is formed as a separate member from the gripping arm body,
This gripping shoe contacts the taper of the charging material and the unevenness of the surface, and the gripping shoe and the gripping arm body are connected by a connecting member to allow a certain degree of relative angle change. Charging material feeding device for vacuum induction melting furnace. 3. In the charge feeding device according to claim 1 or 2, when the lower end of the charge reaches a predetermined position above the bottom of the crucible, the gripping arm opens outward to release the charge. A charging material for a vacuum induction melting furnace characterized by having a positioning member for opening a gripping arm that allows additional charging during melting by dropping into the molten metal in the crucible without giving a harmful impact to the crucible. Insertion device.