JP2002066727A - Unit for supplying molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the connectional molten metal supplying unit using a ladle by solving such problems as temperature fall and spill of molten metal while carried, measuring inaccuracy of molten metal to be supplied, and no lid to cover a furnace. SOLUTION: This unit for supplying the molten metal is provided with a take-in cylinder 25 of the molten metal used to soak a lower half degree into the molten metal 73 by passing through the lid 75 of the melting metal furnace 71, by inserted the measuring ladler 31 of an upper level side into this cylinder 25, and to pass the measuring ladler 35 of a lower level side through this. The molten metal 73 is measured by being made to flow from a flow-in hole 25b of the molten metal into measuring space 81 formed between the measuring ladler 31 of the upper level side and this level side by lowering the measuring ladler 25 of the lower level side, after both the upper and lower ladlers 31, 35 are lifted synchronously as they are, the molten metal is supplied to a mold from a molten metal supplying hole 25a by lifting up the measuring ladler 35 on the lower level side. Without any decrease in the temperature of the ladled molten metal, the measurement of the molten metal is carried out accurately, without any anxiety about the overflow of the ladle molten metal, excellent qualitative molten metal in the deep place in the melting metal furnace can be ladled up, no obstruction is caused in ladling even though a top face of the melting metal furnace is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten metal supply apparatus, and more particularly to a molten metal supply apparatus for automatically measuring and pumping a molten metal in a molten metal furnace in a set amount and supplying the molten metal to a mold or the like. Things.

[0002]

2. Description of the Related Art Conventionally, a ladle a shown in FIG. 5 has been generally used as a means for automatically supplying a molten metal to a mold. The ladle a is attached to, for example, an arm of an articulated robot, and a certain amount of the molten metal b is pumped from the melting furnace and transported to the gate d of the mold c. Supplied to The amount pumped by the ladles a is defined by the size of the ladles a and the inclination angle of the ladles a when the molten metal b is pumped. Therefore, the ladle a scoops the melt surface of the melt furnace and a very shallow region near the melt surface.

[0003]

In such a conventional molten metal supply apparatus, the temperature of the molten metal b pumped up by the ladle a decreases during the transfer from the molten metal furnace to the mold c, or the temperature of the work site is reduced for some reason. There was a dangerous problem of spilling. Further, even if the inclination of the ladle a during the hot water supply is controlled to be constant, there is no guarantee that the amount of the molten metal b pumped by the ladle a is constant, so that the measurement of the molten metal to be supplied is likely to be inaccurate. Furthermore, the molten metal b pumped by the ladle a is exposed to the atmosphere until it is injected into the mold, and the formation of oxides is remarkably observed, which seriously affects the finished quality of the casting.

[0004] A relatively large opening must be opened on the upper surface of the furnace so as to allow at least the ladle a to enter and exit. Even if the opening is opened and closed by a shutter, the opening and closing of the ladle a can be prevented. Since contact is inevitable, the oxidation of the molten metal surface inevitably proceeds, and there is a problem that the heat retention efficiency is poor due to a large temperature decrease due to heat radiation. Moreover, in this pumping method, since the ladle a has to scoop the molten metal surface of the molten metal furnace, that is, a layer with remarkable oxidation, the molten metal always contains a large amount of floating oxides. Would. In particular, when casting magnesium alloys, etc., where the molten metal is highly oxidized, it is important to fill the molten furnace with an inert gas to block the top of the molten furnace and prevent oxidation and ignition. However, the pumping method using the ladle a cannot close the upper surface of the molten metal furnace, so that such a treatment is practically impossible.

[0005] The present invention has been made in view of the above-mentioned conventional problems, and assures that the temperature of the molten metal to be pumped and the generation of oxides are small, and that the molten metal to be pumped is accurately measured. It is an object of the present invention to provide a new molten metal supply device which does not cause spilling of the drawn molten metal on the way and does not cause any trouble in pumping the molten metal even when the upper surface of the molten metal furnace is always closed.

[0006]

In order to attain this object, a molten metal supply device according to the first aspect of the present invention includes a molten metal supply hole for supplying a pumped molten metal and a molten metal inflow hole located below the molten metal supply hole. A molten metal intake cylinder provided with at least a portion including the molten metal inflow hole sinking into the molten metal of the molten metal furnace; an upper level measuring pump element and a lower level measuring pump element inserted into the molten metal intake cylinder so as to be movable up and down. Driving means for raising and lowering these measuring pumps. The upper level defining surface of the upper level measuring pump is opposed to the lower level defining surface of the lower level measuring pump from above. The molten metal flows into the measuring space formed by relatively separating the level defining surface and the lower level defining surface from the molten metal inflow hole, and in this state, the upper level defining surface and the lower level defining surface are raised synchronously. , Upper Le defining surface is characterized in that for discharging the molten metal of the hot water supply holes substantially metric space is raised until it hits the top level defining surface under level defining surface where came at the same height from the hot water supply hole.

Therefore, according to this molten metal supply device,
Since the amount of molten metal pumped from the molten metal furnace is determined by the distance between the upper level defining surface and the lower level defining surface in the molten metal intake cylinder, the amount of molten metal pumped is very accurately measured. Then, the molten metal measured in this manner is carried upward in the molten metal intake cylinder while being kept at the upper level and the lower level, and is supplied from the hot water supply hole toward the mold, so that it spills on the floor or the like on the way. This is unlikely, and the security is very high.

A cylinder for taking the molten metal sinking into the molten metal;
The upper-level measuring pump and lower-level measuring pump inserted therein are always heated to almost the same temperature as the molten metal, so the molten metal pumped from the molten metal furnace is supplied to the mold. Until the temperature drops. Moreover, since the pumping of the molten metal is performed as described above, if the molten metal inflow hole of the molten metal intake cylinder is located at the middle layer of the molten metal furnace, a layer that avoids a surface layer that is easily oxidized and a bottom layer where dross accumulates. High-quality molten metal can be preferentially pumped.

[0009] Even if the upper surface of the molten metal furnace is always closed, there is no trouble in pumping the molten metal. That is, since the molten metal intake cylinder only needs to leave its hot water supply hole outside the molten metal furnace and penetrate through the lid of the molten metal furnace and insert it into the molten metal furnace, the upper surface of the molten metal furnace is completely closed by the lid member. be able to. As a result, it becomes practically possible to fill the furnace with an inert gas for preventing the oxidation and ignition of the molten metal.

[0010] The molten metal supply device described in claim 2 is
2. The molten metal supply device according to claim 1, wherein the upper-level measuring pump is formed into a cylindrical shape having upper and lower ends open and inserted into the molten metal intake cylinder, and the lower-level measuring pump is flanged at the lower end. Part is formed in the shape of a rod, and the part other than the flange part is slidably inserted into the upper level side measuring pump, and the lower end surface of the upper level measuring pump is defined as the upper level defining surface, The upper surface of the flange portion is a lower-level defining surface.

With this structure, it is not necessary to provide the molten metal intake cylinder with a special thickness for accommodating the upper-level measuring pump and the lower-level measuring pump. Since both can be driven from above, the device can be simply and compactly constructed.

[0012] The molten metal supply device according to claim 3 is
In the molten metal supply device according to claim 1 or 2,
An opening hole is provided in a range corresponding to a measuring space to be formed in a peripheral wall of a molten metal intake cylinder. With this configuration, even if the relative separation speed between the upper level defining surface and the lower level defining surface exceeds the inflow speed of the molten metal from the molten metal inflow hole and a vacuum is generated in the measuring space, the vacuum pressure is maintained at the open hole. Since it is opened through the opening, the accuracy of the weighing can be further improved.

[0013] The molten metal supply device according to claim 4 is
4. A pumping amount setting unit for selectively setting a relative separation distance between an upper level defining surface and a lower level defining surface in any one of the molten metal supply devices according to claim 1 to 3. It is characterized by the following. In the present invention, since the relationship between the relative stop positions of the upper-level measuring pump and the lower-level measuring pump determines the size of the measuring space, that is, the pumping amount, this relative stopping position is selected. This makes it possible to arbitrarily set the pumping amount of the molten metal for each shot.

The setting of the pumping amount setting unit may be a method of detecting the position of the metering pump in the moving range using a microswitch, a photoelectric switch, a proximity switch, or the like, or using a stepping motor as a driving means. For example, a method of counting the pulses from the reference position by using such a method can be considered.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A molten metal supply device 1 according to an embodiment of the present invention will be described below with reference to the drawings. [A. Structure] (FIGS. 1 to 4) 3 indicates a base plate of the molten metal supply device 1. The base plate 3 is a portion fixed to a mounting table (not shown) provided above the molten metal furnace 71 and has a rectangular flat plate shape. The direction toward the lower right is referred to as the front side, and the direction in the following description will be referred to in this direction.)
Is attached.

From the position near the front end on the upper surface of the base plate 3, a tall machine frame 5 having a gate shape as viewed from the front and rear stands, and two vertically extending right and left machine frames 5 are provided inside the machine frame 5. A guide shaft 7 is arranged. The guide shaft 7 has a lower end fixed to the base plate 3 and an upper end fixed to the top plate 5 a of the machine frame 5. Guide shaft 7
Supports a lifting body 11. This elevating body 11
Left and right side pipes 13 slidably fitted on the guide shaft 7, a horizontal upper bar 15 connecting upper ends of the left and right side pipes 13, and a horizontal lower bar connecting lower ends of the side pipes 13. The connecting plate 19 is configured to form a rectangular frame shape with the bar 17, and the connecting plate 19 protrudes rearward from the upper bar 15.

A substantially double-acting first hydraulic cylinder 21 is attached to the base plate 3 at a substantially central portion in an upward position, and the distal end of the piston rod 21a is connected to the connection plate 19. Accordingly, when the first hydraulic cylinder 21 is driven, the elevating body 11 moves up and down. A hole 3b (see FIG. 2) is formed in the base plate 3 at an intermediate position between the left and right guide shafts 7, and a thrust bearing 23 is attached to the hole 3b.

A vertically elongated molten metal intake cylinder 25 is attached to the lower surface of the base plate 3. The molten metal intake cylinder 25 is made of ceramics, has a cylindrical shape with upper and lower ends opened, and has a hot water supply hole 25 on its peripheral wall.
a, a molten metal inflow hole 25b and an open hole 25c are formed one by one. The hot water supply hole 25a is provided substantially at an intermediate portion between the middle and the upper end in the longitudinal direction of the melt intake cylinder 25, and the molten metal inflow hole 25b is provided at a substantially middle portion between the middle and the lower end in the same longitudinal direction. The opening 25c is provided at a position near the lower end. Such a molten metal intake cylinder 25 is attached coaxially to the thrust bearing 23 by an attachment ring 27 with its upper end surface being in close contact with the lower surface of the base plate 3.

The lower bar 17 of the elevating body 11 is formed with a hole 17a coaxial with the molten metal intake cylinder 25, and a thrust bearing 23 'is attached to this hole 17a. On the lower surface of the lower bar 17, an upper level side measuring pump 31 is attached. The upper-level measuring pump 31 works in cooperation with a lower-level measuring pump described later to measure and pump the molten metal 73 in the molten metal furnace 71 at a preset amount. In addition, the upper and lower ends are opened by the ceramic, and the molten metal intake cylinder 25 is opened.
It is formed to have a somewhat shorter cylindrical shape, and its outer diameter is a thickness that can be exactly inserted into the center hole of the molten metal intake cylinder 25 while leaving a required clearance. The annular lower end surface of the upper level side measuring pump 31 is
Upper level defining surface 31 that defines the upper level of pumping amount of molten metal
a. The upper level side measuring pump 31 is fixed to the lower bar 17 by a mounting ring 27 'while being slidably inserted into the molten metal intake cylinder 25. Therefore, the first hydraulic cylinder 2
When 1 is driven, the elevating body 11 and the upper level side measuring pump 31 move up and down integrally.

Reference numeral 35 denotes a lower level measuring pump. The lower-level measuring pump 35 is also made of ceramics, and has a cylindrical shape except for the flange 37 at the lower end thereof. The cylindrical portion is the upper-level measuring pump 3.
It is inserted exactly into the center hole with the required clearance. The flange portion 37 is provided for the melt taking cylinder 2
The flange 37 has an annular upper surface serving as a lower level defining surface 37a for defining a lower level of the amount of molten metal to be pumped, leaving a required clearance in the center hole. . The lower level defining surface 37a is
It faces the upper level defining surface 31a from below.

A double-acting second hydraulic cylinder 41 is attached to the upper bar 15 of the elevating body 11 in a downward posture, and the lower end of the piston rod 41a is connected to the lower level side measuring pump 35. The upper end is connected via a coupling 43. Therefore, the first hydraulic cylinder 21
Is driven, the upper-level measuring pump 31 and the lower-level measuring pump 35 move up and down integrally.

The first and second hydraulic cylinders 21 and 41
Is provided with an air oil unit 45 for converting air pressure into hydraulic pressure. Hydraulic cylinders 21 and 41 are driven by hydraulic oil sent from the air oil unit 45.

Reference numeral 51 denotes a pumping amount setting unit. A vertical pole 53 is disposed on the front side of the machine frame 5, and the upper and lower sliders 55, 55 ′ have screws 5 on the pole 53.
7, and a scale plate 59 is attached. The slider 55 has leaf actuator type micro switches 61 and 6.
1 'are attached separately, and the scale plate 59 is provided with a number of scales 59a carved at a constant pitch in the vertical direction. This scale 59a is 1kg, 2kg, ...
The amount in kilograms is displayed, and the lower the value, the larger the value. Lower slider 5
A pointer 63 pointing to a scale 59a is attached to 5.

A switch pressing arm 65 protruding forward is attached to the coupling 43. Each actuator of the microswitches 61 and 61 'moves along the movement locus of the tip of the switch pressing arm 65. Located in.

The upper microswitch 61 is for fixedly defining the hot water supply position of the upper level side measuring pump 31. The switch pressing arm 65 is connected to the microswitch 61 as shown by a solid line in FIG. When the actuator 61 is pressed, the signal output from the switch 61 stops the driving of the first hydraulic cylinder 21 in the rod projecting direction. This hot water supply position is, as shown in FIG.
The upper level defining surface 31a of the upper level side measuring pump 31 is located at a position substantially at the same height as the center of the hot water supply hole 25a,
The position of the upper slider 55 on the pole 53 is set under such conditions.

The lower micro switch 61 'is for selectively defining the lower limit position of the lower level measuring pump 35, and the switch pressing arm 65 is connected to the lower micro switch 61' as shown by a chain line in FIG. When the micro switch 61 'comes to the position of pressing the actuator, this switch 6
1 ', the second hydraulic cylinder 41
Is stopped in the rod projecting direction. Therefore, as the position of the microswitch 61 'is raised, the lower limit position of the lower-level measuring pump 35 is increased. Conversely, as the position of the microswitch 61' is lowered, the lower limit position of the lower-level measuring pump 35 is increased. (In the drawing, the lower limit position of the lower level side measuring pump 35 is set to the lowest position within the adjustable range.) The molten metal supply device 1 is configured as described above.

[B. (Molten Furnace, Installation) (FIGS. 1, 2, and 4) The upper opening of the molten furnace 71 is held almost airtight by a lid 75 made of iron, and a heat insulating material 77 made of ceramic fiber attached to the lower surface of the lid 75. High thermal insulation. Then, a heat insulating material 77 is provided in the molten metal furnace 71.
Close to the aluminum and other molten metal 73,
In the space between the molten metal 73 and the heat insulating material 77, the molten metal 73
Is filled with an inert gas (argon gas, nitrogen, or the like) for preventing oxidation or ignition of the gas.

As described above, the base plate 3 is fixed to the mounting table (not shown) provided above the molten metal furnace 71, and the molten metal intake cylinder 25 includes the lid 75 and the heat insulating material 77.
Is inserted into the molten metal furnace 71 through a through hole formed in the cylinder. This insertion is performed as shown in FIG.
This is performed until the lower end of the molten metal intake cylinder 25 reaches near the bottom wall 71a of the molten metal furnace 71, while leaving a outside the molten metal furnace 71.
As a result, almost the lower half of the molten metal intake cylinder 25 sinks into the molten metal 73, the molten metal inflow hole 25b is located in the middle part of the molten metal 73, and the open hole 25c is located between the middle part and the bottom part. Therefore, the molten metal intake cylinder 25 is always heated to almost the same temperature as the molten metal 73 by the molten metal 73, and the upper-level measuring pump 31 and the lower-level measuring pump 35 are also heated by the molten metal intake cylinder 25. And it is heated to the same extent.

A nozzle 79 made of ceramics is attached to the hot water supply hole 25a of the molten metal intake cylinder 25, and the tip of the nozzle 79 or the supply pipe connected thereto faces the gate of the mold.

[C. Operation] (FIGS. 2 and 4) Next, the method of use and operation of the molten metal supply device 1 will be described (see FIGS. 2 and 4). First, the amount of molten metal pumped, that is, the amount of molten metal 73 required for each shot by the mold is set by the pumping amount setting section 51. For example, when 5 kg is required, the position of the slider 55 is adjusted to a position where the pointer 63 points to the scale 59 a indicating “5 kg” on the scale plate 59.

When a control panel (not shown) is turned on, the molten metal supply device 1 is reset to a standby state shown in FIG. That is, the second hydraulic cylinder 41 is driven in the rod retracting direction to hold the lower-level measuring pump 35 at the pull-up completion position where the lower-level defining surface 37a is pressed against the upper-level defining surface 31a. One hydraulic cylinder 21 is driven in the rod retracting direction, and the upper level side measuring pump 31 is attached to the mounting ring 27 ′ of the thrust bearing 2.
Move to the weighing position that hit 3. In this state,
The upper level defining surface 31a and the lower level defining surface 37a which are pressed against each other are located at the same height as the center of the melt inflow hole 25b, and the melt inflow hole 25b is in contact with the lower end of the upper level side measuring pump 31. It is closed by the flange portion 37 of the lower level side measuring pump 35.

When the operation start switch of the control panel is turned on, first, the second hydraulic cylinder 41 is driven in the rod projecting direction to lower the lower level side measuring pump 35. This lowering stops when the switch pressing arm 65 presses the actuator of the lower micro switch 61 '. This state is the state shown in FIG. As a result, the lower level defining surface 37a becomes the upper level defining surface 31
A measuring space 81 is formed at a distance from “a”, and the molten metal 73 flows into the measuring space 81 from the molten metal inflow hole 25b whose lower half is opened. This inflow is also partially performed from the open hole 25c. The molten metal flowing into the measuring space 81 in this way is of good quality from the middle layer to the near side of the bottom layer, which is sufficiently below the liquid level where oxidation is remarkable.

The volume of the measuring space 81 is a size corresponding to the weight set in advance by the pumping amount setting unit 51. When the measuring space 81 is filled with the molten metal 73,
The weighing is completed. When the lowering speed of the lower level side measuring pump 35 is faster than the inflow of the molten metal 73, a vacuum is generated in the measuring space 81, and the vacuum is released through the opening 25c. Since the length of the weighing space 81 varies depending on the weight set by the pumping amount setting unit 51, the open hole 25c is vertically moved so that the open hole can correspond to the weighing space regardless of the set weight. It is good to provide a plurality.

After a certain period of time has passed after the lower-level measuring pump 35 has been lowered, the first hydraulic cylinder 21 is driven in the rod projecting direction, and the upper-level measuring pump 35 is driven. 31 and the lower level measuring pump 35 are raised at the same time. With this rise, the molten metal 73 filling the measuring space 81 also rises. This upward movement is performed until the switch pressing arm 65 presses the upper microswitch 61, and the upper level side measuring pump 3
1 comes to the hot water supply position shown in FIG. 2 and FIG. 4 (C). In this state, upper level defining surface 31a is located at substantially the same height as the center of hot water supply hole 25a.

Next, the second hydraulic cylinder 41 is driven in the rod retracting direction to raise the lower level side measuring pump 35 to the pulling completion position. As a result, the lower level defining surface 37a pushes up the molten metal 73 in the measuring space 81, so that the molten metal 73 flows out of the hot water supply hole 25a to the nozzle 79 and is supplied to the target mold.

When a certain time has elapsed since the upper micro switch 61 was pressed, the first hydraulic cylinder 21
Is driven in the rod retraction direction to return to the standby state shown in FIG. 4A, and the one-cycle operation ends. By repeating such a cycle operation, the required amount of molten metal 73 is reduced to 1
Each shot is weighed and pumped and supplied to the mold.

The embodiment of the present invention has been described above.
The specific configuration of the present invention is not limited to this embodiment, and any change in design or the like without departing from the spirit of the present invention is also included in the present invention. For example, in the embodiment, the upper level defining surface is fixed and the lower level defining surface is lowered to form the measurement space.
In some cases, the lower level defining surface may be fixed and the upper level defining surface may be raised.

The shape of the molten metal intake cylinder in the present invention does not necessarily have to be cylindrical as a whole, and at least a portion between the maximum lowering position of the lower level defining surface and the hot water supply hole is closed in a cylindrical shape. It just needs to be in the shape that was done. Further, in the embodiment, an air-hydro type cylinder is used as the driving means. However, this driving means may be an electric type in addition to a fluid type actuator such as air or oil.

[0039]

As described above, according to the present invention, it is possible to guarantee that the temperature of the molten metal that is pumped from the molten metal furnace and supplied to the mold is small, and that the molten metal to be pumped is accurately measured. There is no danger of spilling molten metal in the supply process. Also, the pumping of the molten metal is performed in a desired layer in the molten metal furnace,
For example, since it can be performed in the middle layer portion avoiding the surface layer portion and the bottom layer portion, it is possible to supply a high-quality molten metal free of oxides. And even if the top of the furnace is always closed, there is no hindrance to the pumping of the molten metal.Therefore, cover this to take measures to prevent heat radiation and safety measures, or to put inert gas into the furnace. Filling is also practically possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a molten metal supply device according to an embodiment of the present invention.

FIG. 2 is a side view showing the molten metal supply device shown in FIG. 1 with a part cut away.

FIG. 3 is an exploded perspective view of an essential part of the molten metal supply device shown in FIG.

FIG. 4 is a diagram showing the operation of the molten metal supply device shown in FIG. 1 in order from (A) to (C).

FIG. 5 is a diagram showing an example of a conventional molten metal supply device.

[Explanation of symbols]

1 .... molten metal supply device 21, 41, 45, 45 '...
Driving means 25: Molten intake cylinder 25a: Hot water supply hole 25
b: melt inflow hole 25c: open hole 31: upper level side measuring pump 31a: upper level defining surface 35: lower level side measuring pump 37: flange portion (of lower level side measuring pump) 37a: lower Level regulation surface 51: Pumping amount setting unit 71: Molten furnace 73: Molten 81: Measuring space

Claims (4)

[Claims] 1. A molten metal supply cylinder for supplying a pumped molten metal, a molten metal inflow hole positioned below the molten metal supply hole, a cylinder including at least a portion including the molten metal inflow hole, sinking into the molten metal of a molten metal furnace, and a molten metal intake cylinder. An upper-level measuring pump and a lower-level measuring pump that are inserted into the intake cylinder so as to be able to move up and down, and driving means for moving the measuring pump up and down; The level defining surface is opposed to the lower level defining surface of the lower level measuring pump from above, and the molten metal is formed in the measuring space formed by relatively separating the upper level defining surface and the lower level defining surface. The molten metal flows in from the inflow hole, and in this state, the upper level defining surface and the lower level defining surface are raised in synchronization with each other. The specified surface Molten metal supplying apparatus characterized by discharging the molten metal metering space is raised from the hot water supply hole to. 2. The molten metal supply device according to claim 1, wherein the upper level side measuring pump is formed into a cylindrical shape having upper and lower ends open and inserted into a molten metal intake cylinder. Is formed in a rod shape with a flange formed at the lower end, and the other parts than the flange are slidably inserted into the upper level side measuring pump, and the lower end face of the upper level side measuring pump is raised. A molten metal supply device, wherein a level defining surface is provided, and an upper surface of the flange portion is a lower level defining surface. 3. The molten metal supply device according to claim 1, wherein an opening is provided in a peripheral wall of the molten metal intake cylinder in a range corresponding to a measuring space to be formed. Metal feeder. 4. A pumping amount setting for selectively setting a relative separation distance between an upper level defining surface and a lower level defining surface in any one of the molten metal supply devices according to claim 1 to 3. A molten metal supply device characterized by comprising a part.