JP7276026B2 - Hot water supply device for casting and hot water supply method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting hot water supply apparatus and a hot water supply method for supplying molten metal using a ladle.

In order to supply the molten metal used for casting, for example, to an injection sleeve provided in a die casting machine, a water heater is used that pumps out the molten metal from the furnace with a ladle and conveys it to a supply destination.
The ladle is transported from the furnace to a supply destination by a drive mechanism including a motor, an arm, etc., and tilted about a rotation axis. The ladle is tilted at a predetermined angle by the driving mechanism when the molten metal is pumped out or supplied to the supply destination.
The basic operation of the ladle is that after the ladle is inserted into the molten metal in the furnace, the ladle is raised against the surface of the molten metal to pump out an amount of molten metal corresponding to the product to be cast. The ladle is held in a neutral position and conveyed toward the supply destination, and the ladle is tilted at the pouring position at the supply destination to pour the molten metal from the ladle into the pouring port of the injection sleeve or the like. In order to position the ladle at the pouring position, the ladle is typically decelerated before the pouring position.

According to the hot water supply method described in Patent Document 1, while the ladle is decelerated in the middle of the section in which the ladle is conveyed from the furnace to the pouring position, in order to shorten the cycle time, tilting of the ladle is started prior to pouring. ing. The ladle is tilted to a predetermined angle by operating a limit switch provided on the rotating shaft of the ladle.

JP-A-6-114526

Based on the set value of the molten metal weight according to the product to be cast, the ladle's approach angle and depth during weighing are appropriately determined, and the amount of molten metal corresponding to the set value is metered into the ladle. However, the amount of molten metal weighed into the ladle varies with each casting cycle due to changes in the ambient temperature and surface conditions of the molten metal, and the position of the surface of the molten metal in the ladle also varies. The position of the surface of the molten metal in the ladle also varies due to tolerances in the dimensions and shape of the ladle.

Even if the molten metal surface position is the highest in the range of variation in the molten metal surface position, it is necessary to prevent the molten metal from overflowing from the ladle when the ladle is tilted prior to pouring the molten metal. Therefore, the angle at which the ladle is tilted prior to pouring is set to a value that is less than the upper limit angle at which the molten metal does not actually overflow from the ladle and allows for a margin with respect to the upper limit angle. If so, the cycle time cannot necessarily be sufficiently shortened.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hot water supply apparatus and a hot water supply method for casting that can reliably shorten the casting cycle time.

The present invention is a casting hot water supply apparatus for supplying molten metal to a supply destination, comprising a ladle for pumping molten metal from a furnace and pouring it into the supply destination, and a ladle capable of being transported to a pouring position at the supply destination. a drive unit capable of tilting a ladle about a predetermined rotation axis; and a surface position of molten metal pumped out of the furnace and stored in the ladle. The ladle is tilted prior to reaching the pouring position by calculation based on the dimensions and shape of the ladle using the detection unit and the position of the molten metal surface detected by the molten metal surface position detection unit in each casting cycle. and a control unit for calculating a pre-tilt angle, which is the upper limit angle at which the molten metal does not overflow from the ladle.

In the hot water supply apparatus for casting of the present invention, it is preferable that the hot water level detection unit includes an optical sensor (laser sensor) using a laser beam.

In the hot water supply apparatus for casting of the present invention, it is preferable that the control section uses the position of the molten metal surface detected by the molten metal surface position detecting section and the type of ladle related to the volume or shape of the ladle for calculating the pre-tilt angle.

Further, the present invention is a casting hot water supply method for supplying molten metal to a supply destination, comprising: a metering step of measuring molten metal from a furnace to a ladle; a transfer step of transferring the ladle from the furnace to the supply destination; In parallel with the ladle surface position detection step of detecting the surface position of the molten metal pumped out and stored in the ladle, and the transfer step, the ladle is moved to a predetermined position before the ladle reaches the pouring position at the supply destination. and a pouring step of injecting molten metal from the ladle into a supply destination by tilting the ladle at the pouring position. The ladle is tilted to a pre-tilt angle, which is the upper limit angle at which the molten metal does not overflow from the ladle, which is calculated by calculation based on the dimensions and shape of the ladle, using the position of the molten metal surface detected by the detection step. and

In the casting hot water supply method of the present invention, in the ladle surface position detection step, it is preferable to detect the surface position of the molten metal stored in the ladle using a laser beam emitted to the surface of the molten metal.

In the casting hot water supply method of the present invention, it is preferable to start the pre-tilting step after reducing the ladle conveying speed in the middle of the conveying step.

According to the present invention, the actual ladle calculated based on the dimensions and shape of the ladle to be used using the actually measured position of the molten metal surface in the ladle for each casting cycle in which the position of the molten metal surface in the ladle varies. The ladle can be tilted in the pouring direction prior to the ladle reaching the pouring position up to the upper limit of the pre-tilt angle at which the molten metal does not overflow. In other words, in each cycle, the ladle being transported can be tilted up to the upper limit angle with virtually no margin, prior to pouring. Therefore, the casting cycle time can be reliably shortened.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a schematic configuration of a hot water supply apparatus for casting according to an embodiment of the present invention; 2(a) and 2(b) are diagrams showing a part of the water heater shown in FIG. 1. FIG. (b) is a view showing part of the water heater from the direction of arrow IIb in (a). 2 is a diagram showing an internal configuration of a control device provided in the hot water supply apparatus shown in FIG. 1; FIG. FIG. 10 is a diagram schematically showing changes in the attitude of the ladle when it enters the molten metal in the furnace, when it is transported, and when it is pre-tilted. FIG. 5 is a diagram showing an example in which the amount of molten metal in the ladle is different from that in FIG. 4; 4 is a timing chart of the present embodiment showing ladle transport and tilting operations; It is a timing chart of a comparative example. It is a timing chart concerning the modification of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
A casting hot water supply apparatus 1 shown in FIG. Feed melt 2. The supply destination 5 corresponds to, for example, an injection sleeve 51 provided in an injection device of a die casting machine. The inside of the injection sleeve 51 communicates with a mold cavity (not shown). The molten metal 2 supplied to the inside of the injection sleeve 51 from the pouring port 51A provided in the injection sleeve 51 is injected and filled into the cavity by advancing the tip 52 of the plunger toward the cavity side of the mold. .
Casting using the hot water supply apparatus 1 and a die casting machine (not shown) is performed by a casting cycle including, for example, mold closing, injection/filling, pressure holding/pressure increasing, mold opening, and product ejection.

As shown in FIGS. 1, 2(a) and 2(b), the hot water supply apparatus 1 includes a ladle 4 for pumping out the molten metal 2 from the furnace 3 and pouring it to a supply destination, a drive unit 10 for driving the ladle 4, An optical sensor 6 (FIGS. 2(a) and 2(b)) as a molten metal surface position detection unit configured to detect the molten metal surface 2B of the molten metal 2 pumped out and stored in the ladle 4, and a driving unit. 10, and a control device 20 as a control unit for controlling . The control device 20 includes a computer device, and includes a CPU (Central Processing Unit), an arithmetic processing unit 21 (FIG. 3) such as a microprocessor including a memory, and a storage unit 22 (FIG. 3) that stores various setting values, program data, and the like. 3). The control device 20 may be part of a control device of a die casting machine (not shown).

The drive unit 10 conveys the ladle 4 between the furnace 3 and the supply destination 5, and tilts the ladle 4 in predetermined postures during weighing, transportation, and pouring.
The ladle 4 is rotated about a predetermined rotation axis A3 by the drive unit 10, thereby tilting with respect to the neutral posture (neutral position) shown in FIG. 2(a). The rotation of the ladle 4 about the rotation axis A3 is called "tilting".

FIG. 1 schematically shows an example of the configuration of the driving section 10. As shown in FIG. As shown in FIG. 1, the drive unit 10 is connected to a first arm 11 rotatably supported on a pedestal 13 about a rotation axis A1, and rotatable about a rotation axis A2 to the first arm 11. and a ladle rotation mechanism 14 for rotatably connecting the ladle 4 to the second arm 12 .

The ladle rotation mechanism 14 rotates the ladle 4 with respect to the second arm 12 around a rotation axis A3 coupled to the ladle 4 and the second arm 12 . The rotating shaft A3 is arranged in the vicinity of the spout 4A of the ladle 4 along a direction perpendicular to the direction in which the molten metal 2 is poured. A mounting member 7 (FIGS. 2(a) and 2(b)) for supporting the optical sensor 6 is provided on the rotating shaft A3.
The ladle rotation mechanism 14 includes a motor 141 (FIGS. 2B and 3) that outputs torque to the rotation axis A3, and an encoder (rotary motor) provided on the rotation axis A3 that can detect the position of the rotation axis A3 in the rotation direction. encoder) 142 (FIGS. 2(b) and 3).

In addition to the components described above, the drive unit 10 includes, although not shown, a motor that swings the first arm 11 with respect to the base 13 by outputting torque to the rotation axis A1, and a rotation direction of the rotation axis A1. A rotary encoder for detecting the position, a motor for swinging the second arm 12 with respect to the first arm 11 by outputting torque to the rotary shaft A2, a rotary encoder for detecting the position of the rotary shaft A2 in the rotational direction, and a speed reducer. , and chains, etc.

The control device 20 controls the motors and speed reducers of the drive unit 10 that swings the first arm 11 and the second arm 12, so that the ladle 4 moves along a locus 100 shown in FIG. 1 from the furnace 3 to the supply destination 5. It is drawn and conveyed at a predetermined speed.
Further, the controller 20 controls the motor 141 of the ladle rotation mechanism 14 that tilts the ladle 4, so that the ladle 4 is tilted to a predetermined posture B1 during weighing and a predetermined posture B4 during pouring. be.

The control device 20 performs feedback control of at least the position and the speed of the motors corresponding to the respective rotary axes A1 to A3 while detecting the rotary positions of the respective rotary axes A1 to A3 by means of rotary encoders. 4 is conveyed along a trajectory 100 and tilted to a predetermined posture at the appropriate time.

An example of a feedback loop is shown in FIG.
The feedback loop shown in FIG. 3 includes a control signal source 211, a comparator 212, a motor driver 23, an amplifier 24, a motor 141, and an encoder counter 25.
Based on the comparison result (deviation) by the comparator 212 between the control signal C1 generated from the control signal source 211 of the arithmetic processing unit 21 and the signal C2 output from the encoder counter 25 that counts the pulse signal output from the encoder 142. Then, the control amount is input to the motor driver 23 . Then, the motor 141 is driven to rotate the rotating shaft A3, and the ladle 4 follows the rotation of the rotating shaft A3 and tilts up to a predetermined angle corresponding to the target position of the rotating shaft A3.

The ladle 4 (FIGS. 2(a) and (b)) temporarily stores the molten metal 2 pumped out of the furnace 3 and pours the molten metal 2 from the pouring spout 4A into the pouring spout 51A of the supply destination 5. FIG. The ladle 4 is formed by casting or the like from materials such as metals, metal oxides, ceramics, etc., which have the required heat resistance.
The ladle 4 has a capacity for storing the required amount of the molten metal 2 to be used for casting the product, and is capable of smoothly pumping the molten metal 2 from the furnace 3 and expelling the entire amount of the molten metal 2 smoothly. A given shape is given.
Typically, casting of various products is carried out using a plurality of types of ladles having different capacities and shapes depending on the products to be cast.

The amount of the molten metal 2 used for casting can be set in the controller 20 as a molten metal weight parameter Ps indicating a set value of the weight of the molten metal according to the product to be cast.
The type of ladle 4 used for casting can also be set in the controller 20 as a ladle type parameter Pt according to the product to be cast.
These parameters Ps and Pt are stored in the storage unit 22 as necessary, and used for controlling the driving of the arms 11 and 12 and the ladle 4 when the molten metal 2 is measured.

When the rotating shaft A3 is rotated by the motor 141 in the direction of lowering the spout 4A of the ladle 4 (counterclockwise direction R1 in FIG. 2A), the ladle 4 tilts following the rotation of the rotating shaft A3. The molten metal 2 flows down from the pouring port 4A.

The basic operation of the ladle 4 shown in FIG. 1 is as follows. A large amount of molten metal 2 is pumped out by the ladle. At this time, under the control of the control device 20, the ladle rotation mechanism 14 rotates the ladle 4 above the furnace 3 in the direction opposite to the direction of tilting during pouring (clockwise direction R2 in FIG. 2(a)). Then, the furnace 3 is tilted until it reaches a predetermined approach posture B1, and the position of the molten metal surface 2A in the furnace 3 is detected by a known molten metal surface detection sensor 8 or the like equipped with detection rods 81 and 82 such as metal, By the operation of the first arm 11 and the second arm 12, the ladle 4 is caused to enter the molten metal 2 in the furnace 3 from the molten metal surface 2A to a predetermined depth.

Both the detection rods 81 and 82 are conductors, and voltage is applied to the detection rods 81 and 82 . Detection rods 81 and 82 are supported by second arm 12 in parallel with second arm 12 . A lower end 81A of the detection rod 81 and a lower end 82A of the detection rod 82 are positioned near the rotation axis A3, for example. By adjusting the attachment positions of the detection rods 81 and 82 to the second arm 12, the positions of the lower ends 81A and 82A can be adjusted.
When the second arm 12 descends toward the molten metal 2 in the furnace 3 and both the lower end 81A of the detection rod 81 and the lower end 82A of the detection rod 82 contact the molten metal 2, the detection rods 81 and 82 and the molten metal 2 are detected. The position of the hot water level 2A can be detected by the current flowing through the formed closed circuit. The penetration depth of the ladle 4 can be determined by the operation of the first arm 11 and the second arm 12 with respect to the position of the hot water surface 2A.

After that, the ladle 4 immersed in the molten metal 2 is tilted counterclockwise R1 toward the neutral position, and furthermore, the movement of the first arm 11 and the second arm 12 causes the molten metal surface 2A in the furnace 3 to rotate. A predetermined amount of molten metal 2 is metered into the ladle 4 when the ladle 4 is pulled up. After raising the ladle 4 from the molten metal surface 2A, by tilting the ladle 4 as necessary, part of the molten metal 2 pumped out by the ladle 4 is discharged into the furnace 3, and a predetermined amount of molten metal 2 is discharged. The molten metal 2 may be left in the ladle 4.

After weighing, the ladle 4 is conveyed toward the supply destination 5 by the first arm 11 and the second arm 12, and the ladle 4 is poured at a pouring position 53 (above near the pouring port 51A) at the supply destination 5. The molten metal 2 is supplied from the ladle 4 to the inside of the injection sleeve 51 through the pouring port 51A by tilting it to the posture B4.
In the process of transporting the ladle 4 from the furnace 3 to the supply destination 5, the angle of the ladle 4 with respect to the second arm 12 is adjusted by the ladle rotation mechanism 14 under the control of the control device 20, so that the molten metal 2 is transferred from the ladle 4. It is preferable to maintain the ladle 4 in a neutral position to prevent overflow.
Although the transport speed of the ladle 4 may be constant throughout the process of transporting the ladle 4 from the furnace 3 to the supply destination 5, the casting cycle time is shortened and the ladle 4 is reliably stopped at the pouring position 53. Therefore, it is preferable to variably control the conveying speed of the ladle 4 as described later.

In addition to the operation of the ladle 4 described above, in this embodiment, prior to the arrival of the ladle 4 at the pouring position 53, as shown at D3 in FIG. At angle θ3, which is the upper limit angle, the ladle 4 is tilted in the same direction as the pouring posture B4 (FIG. 1). Then, typically, while the ladle 4 conveyed to the pouring position 53 is stopped at the pouring position 53, the operation of tilting the ladle 4 toward the pouring posture B4 is started. , the operation of tilting the ladle 4 for pouring is started during transport of the ladle 4 prior to the arrival of the ladle 4 at the pouring position 53 . Casting cycle time can be shortened by starting early.

FIG. 4 shows, as rotation angles of the ladle 4, angles θ1 and θ3 of the axis L of the ladle 4 with respect to a vertical line (indicated by a one-dot chain line) drawn in the vertical direction. The approach angle θ1 indicated by D1 in FIG. As shown at D2 in FIG. 4, when the ladle 4 is in the neutral position, the angle of the ladle 4 with respect to the vertical line is 0°.
The angle θ3 indicated by D3 in FIG. 4 corresponds to the angle at which the ladle 4 is preliminarily inclined prior to the ladle 4 reaching the pouring position 53 . Prior to the ladle 4 reaching the pouring position 53, the ladle 4 is pre-inclined in the tilting direction during pouring. shall be referred to as angle θ3.

The angle θ1 at which the ladle 4 enters the molten metal 2 during measurement, the depth of penetration of the ladle 4 with respect to the molten metal surface 2A, and the like are determined based on the set value of the molten metal weight indicated by the above-described molten metal weight parameter Ps and the type of the ladle 4 used. A predetermined amount of melt 2, which can be determined and corresponds to a set value of melt weight, is metered into the ladle 4.
Of the angles θ1 and θ3 described above and the angle θ4 (FIG. 1) of the ladle 4 in the pouring posture B4, at least the approach angle θ1 and the pre-tilt angle θ3 are Change.
For example, in the example shown in FIG. 5, the set value of the molten metal weight used for the product is different from the example shown in FIG. The volume and shape of the ladle 4 shown in FIG. 5 are the same as the volume and shape of the ladle 4 shown in FIG. The approach angle θ1-5 shown in FIG. 5 is different from the approach angle θ1 shown in FIG. Similarly, the pre-tilt angle θ3-5 shown in FIG. 5 is different from the pre-tilt angle θ3 shown in FIG.

The pre-tilt angles θ3 and θ3-5, which are the upper limit rotation angles of the ladle 4 during pre-tilt, are geometrically and uniquely determined from the set value of the molten metal weight and the type of the ladle 4 used.
However, the amount (weight or volume) of the molten metal 2 pumped out of the furnace 3 and stored in the ladle 4 varies depending on the ambient temperature, ripples on the surface of the molten metal, and changes in the solidification state of the molten metal. It varies from cycle to cycle, and the position of the molten metal surface 2B in the ladle 4 also varies. Even if the amount of molten metal 2 equal to the set value is metered into the ladle 4, the position of the molten metal surface 2B in the ladle 4 varies due to tolerances in the dimensions and shape of the ladle 4. Then, the pre-inclination angles θ3 and θ3-5 also vary.

For example, it is assumed that the pre-tilt angle θ3 shown in FIG. 4 is a value uniquely derived from the position of the molten metal surface in the ladle 4 based on the designed dimensions and shape of the ladle 4 to be used and the designed value of the weight of the molten metal. . In this case, the pre-tilt angle .theta.3 shown in FIG. However, in practice, the position of the molten metal surface 2B in the ladle 4 varies depending on the ambient temperature, the state of the molten metal surface 2A, and the tolerance of the dimensions and shape of the ladle 4. The angle θ3 also varies.

Therefore, in this embodiment, the position of the molten metal surface 2B of the molten metal 2 weighed by the ladle 4 is detected by the optical sensor 6 for each casting cycle. The upper limit of tilting of the ladle 4 without the molten metal 2 overflowing from the ladle 4 is determined by geometrical calculations performed by the pre-tilt angle calculation unit 213 of the calculation processing unit 21 based on the designed dimensions and shape of the ladle 4. A pre-tilt angle θ3 is calculated.

The pre-tilt angle calculator 213 is a module of a program executed by the arithmetic processor 21 . This pre-inclination angle calculator 213 uses known data preset in the control device 20 for the type of ladle 4 to be used, such as data indicating the relationship between the position of the molten metal surface in the ladle 4 and the amount of molten metal, or an optical A pre-tilt angle θ3 is calculated from the detection signal output from the optical sensor 6 by using a formula or the like having the detection signal from the formula sensor 6 as a variable. A control amount is given to the motor driver 23 based on the target position of the rotary shaft A3 corresponding to the pre-tilt angle θ3, so that the ladle 4 is tilted up to the pre-tilt angle θ3 prior to pouring molten metal.

The optical sensor 6 (FIGS. 2(a) and 2(b)) can detect the position of the molten metal surface 2B in the ladle 4 in a non-contact manner using laser light. The optical sensor 6 includes a laser light source, a lens, and light receiving elements such as CMOS (Complementary Metal Oxide Semiconductor) and CCD (Charged-Coupled Devices). This optical sensor 6 is based on the phase between the light emitted from the laser light source toward the surface 2B of the molten metal 2 stored in the ladle 4 and the light reflected from the surface 2B and incident on the light receiving element. Therefore, it is possible to accurately detect the position of the molten metal surface 2B with respect to the reference position.
By providing an appropriate distance between the optical sensor 6 and the molten metal surface 2B in the ladle 4, the optical sensor 6 avoids the influence of the heat of the molten metal 2 on the optical sensor 6. Reliability of detection can be ensured.

The flow of the hot water supply process performed under the control of the controller 20 using the hot water supply apparatus 1 described above will be described based on the control example shown in FIG.
FIG. 6 shows the movements of the arms 11 and 12 related to the transport of the ladle 4 in one cycle Ts of the hot water supply process including weighing and pouring (upper part of FIG. 6), and the tilting operation of the ladle 4 in one cycle Ts (see FIG. 6). 6) are shown by the same time axis.
In this example, the detection of the molten metal surface 2A in the furnace 3 (S01) performed after the ladle 4 has entered the molten metal 2 in the furnace 3 and the detection of the molten metal surface 2A in the next cycle (S01) It is shown as one cycle Ts.
A predetermined amount of molten metal 2 is weighed from a furnace 3 to a ladle 4, and while the molten metal 2 is kept in the ladle 4 so that the measured molten metal 2 does not overflow from the ladle 4, the molten metal 2 is rapidly supplied to the destination before it cools. By pouring the molten metal 2 into 5, we would like to shorten the casting cycle time including the hot water supply process.

6, the movement of the arms 11 and 12 causes the ladle 4 to advance from the furnace 3 toward the supply destination 5, or when the ladle 4 rises with respect to the molten metal surface 2A, the conveying speed of the ladle 4 is positive (+ ), and conversely, the conveying speed of the ladle 4 is negative ( -).
6, the rotation speed when the ladle rotation mechanism 14 rotates the ladle 4 counterclockwise R1 in FIG. is rotated clockwise R2 in FIG. 2(a), the negative (-) sign indicates the rotation speed.

One cycle Ts consists of a weighing step S1 of pumping a predetermined amount of molten metal 2 into the ladle 4 through a process of tilting the ladle 4 in the positive direction and raising the ladle 4 with respect to the molten metal surface 2A, and A ladle surface position measuring step S2 for actually measuring the position of the molten steel surface 2B, a forward step S3 for conveying the ladle 4 from the furnace 3 to the supply destination 5 in the positive direction, and a pre-tilt angle θ3 in the positive direction during conveyance of the ladle 4. and the ladle 4 is further tilted in the + direction at the pouring position 53 (here, the limit of the movement of the ladle 4 by the arms 11 and 12) to pour the molten metal 2 into the pouring port 51A of the supply destination 5. A pouring step S5 of pouring the ladle 4, a retreating step S6 of conveying the ladle 4 toward the furnace 3 in the - direction while tilting it in the - direction and returning it to the neutral position, and a weighing command at the retreat limit of the ladle 4. It includes a cycle adjusting step S7 for waiting to be emitted, and a furnace entering step S8 for lowering the ladle 4 while tilting it in the - direction to enter the molten metal 2 in the furnace 3.

The weighing step S1 includes a first weighing step S11 in which the ladle 4 immersed in the molten metal 2 is tilted up to a weighing angle θ2 in the positive direction, a rising step S12 in which the ladle 4 is lifted from the melt surface 2A, and the molten metal in the ladle 4. A first measuring step S13 of measuring the amount using, for example, a load cell (not shown) or the like, a second measuring step S14 of further tilting the ladle 4 in the + direction to return it to the neutral position, and using, for example, a load cell or the like. and a second measuring step S15 for measuring the amount of molten metal in the ladle 4.

In the weighing step S1, in order to improve the accuracy of weighing, prior to the weighing step S1 (furnace entry step S8), the ladle 4 entered into the molten metal 2 while being tilted to the entrance angle θ1 in the − direction is + Preferably, a defined amount of molten metal 2 is metered into the ladle 4 through a first metering step S11 of tilting in the direction to a metering angle θ2.

Here, due to the backlash existing in the gear structure of the ladle rotation mechanism 14 and the buoyancy by the molten metal 2, the ladle 4 can be displaced in the + direction or the - direction when entering the molten metal 2. Therefore, the approach angle θ1 is set larger than the angle that is displaced in the negative direction due to backlash and buoyancy compared to the angle calculated based on the set value of the molten metal weight and the shape of the ladle 4.
Therefore, even if the ladle 4 is displaced in an undefined direction due to backlash and buoyancy when entering the molten metal 2, by tilting the ladle 4 in the positive direction, that is, in a constant direction, the ladle 4 can be adjusted to the metering angle θ2. They can be matched with high accuracy. Then, an amount of molten metal 2 corresponding to the metering angle θ2 is stably pumped out to the ladle 4, thereby improving the metering accuracy.

In the second measuring step S14, by controlling the tilting speed of the ladle 4 based on the measurement result in the first measuring step S13, part of the molten metal 2 in the ladle 4 is moved outside the ladle 4 as necessary. By discharging, the molten metal 2 is weighed into the ladle 4 in an amount corresponding to the set value of the molten metal weight. By the second measurement step S15, it is confirmed that the molten metal 2 is stored in the ladle 4 in an amount corresponding to the set value of the molten metal weight.

Subsequently, in the ladle surface position measurement step S2, the optical sensor 6 actually measures the position of the surface 2B in the ladle 4. FIG. The pre-tilt angle calculator 213 (FIG. 3) calculates the pre-tilt angle θ3 from the actually measured position of the molten metal surface 2B and the type of the ladle 4 indicated by the ladle type parameter Pt. The ladle surface position measurement step S2 is preferably performed while the operation of the ladle 4 is stopped.
By calculating the pre-tilt angle .theta.3 for each cycle Ts using the measured values obtained in the ladle surface position measurement step S2, the pre-tilt angle .theta.3 is corrected from the design reference value.

By using the detection results of the hot water surface 2B position by a plurality of optical sensors 6, or by using together the detection results of the hot water surface 2B position by the optical sensors 6 and the weight detection results of, for example, a load cell, the prediction can be performed. The accuracy of correcting the tilt angle θ3 can be improved.

The forward step S3 consists of a first forward step S31 and a second forward step S32, in which the ladle 4 is transported to the pouring position 53 by switching the speed in two stages. Specifically, the ladle 4 is advanced at a relatively high first conveying speed V1 halfway in the section from the position of the furnace 3 to the advance limit. After that, in order to stop the ladle 4 at the pouring position 53, the ladle 4 is advanced at the relatively slow second conveying speed V2.
The magnitude of the first conveying speed V1 and the second conveying speed V2 and the switching timing of the conveying speeds V1 and V2 are appropriately determined so that the molten metal 2 does not overflow from the ladle 4 due to inertial force.

The pre-tilt step S4 tilts the ladle 4 to the pre-tilt angle θ3 while the ladle 4 is being transported by the advance step S3. By starting the tilting of the ladle 4 in the + direction from the neutral position prior to the arrival of the ladle 4 at the pouring position 53, for example, the ladle 4 The time required for the cycle Ts (cycle time) can be shortened by the time t1 during which the tilting of the ladle 4 in the positive direction is performed in parallel with the transport of the ladle 4 .

When the ladle 4 stops at the forward limit, the ladle 4 is tilted in the + direction from the neutral position, as indicated by circles (o) in the upper (ladle transport) and lower (ladle tilting) stages in FIG. No rollover action has been initiated. Unlike the comparative example of FIG. 7, in this embodiment, the ladle 4 is tilted in the positive direction from the neutral position while the ladle 4 is being transported to the forward limit. From the viewpoint of preventing the molten metal 2 from overflowing the ladle 4, it is preferable to avoid tilting the ladle 4 when the molten metal surface 2B is rippling due to the inertial force accompanying changes in the conveying speed of the ladle 4. Therefore, as in the present embodiment shown in FIG. 6, it is preferable to start pre-inclination of the ladle 4 after finishing the switching from the first conveying speed V1 to the second conveying speed V2.
Then, it is preferable that the ladle 4 is completely tilted to the pre-tilt angle θ3 by the end of the forward step S3.

In the example shown in FIG. 6, the motor 141 is operated from the time tx when the ladle 4 conveying speed is switched from the first conveying speed V1 to the second conveying speed V2. pre-tilt is completed.
This is an example, and the cycle time can be shortened by performing at least part of the pre-tilt step S4 in parallel with the forward step S3.

The speed at which the ladle 4 is tilted in the positive direction in the pre-tilting step S4 can be determined as appropriate as long as the molten metal 2 does not overflow from the ladle 4 . If the entire pre-tilting step S4 is performed in parallel with the advancing step S3, the ladle 4 can be pre-tilted while preventing overflow of the molten metal 2 compared to the case where part of the pre-tilting step S4 is performed in parallel. The tilting can be reliably performed up to the angle θ3.
The tilting speed v1 of the pre-tilt in the example shown in FIG. 6 is equivalent to the tilting speed v1 of the ladle 4 in the subsequent first pouring step S51.

In the pre-tilting step S4, the ladle 4 is tilted to the maximum extent in the + direction within a range in which the molten metal 2 does not overflow from the ladle 4. Therefore, compared to the comparative example (FIG. 7) in which no pre-tilting is performed, the pouring step S5 At the beginning of , the remaining angle relative to the pouring angle θ4 (FIG. 1) is small. In other words, the ladle 4 can be tilted to the pouring angle θ4 in a shorter time from the time when the ladle 4 reaches the pouring position 53 and pouring is started.
If the tilting speed of the ladle 4 during pouring is too high, the molten metal 2 may overflow from the ladle 4, so there is a limit to the tilting speed during pouring.

The pouring step S5 that follows the pre-inclining step S4 consists of a first pouring step S51 and a second pouring step S52. tilt up to Specifically, from the pre-tilt angle θ3 to the first pouring angle, the ladle 4 is tilted at a relatively fast first tilting speed v1, and then the ladle 4 is tilted at a relatively slow second tilting speed v2. 4 is tilted to stop at the second pouring angle (same as the pouring angle θ4 and the pouring limit). At the end of the second pouring step S52, the entire amount of the molten metal 2 is dispensed from the ladle 4 while the ladle 4 is stopped at the forward limit and the pouring limit.

After pouring the molten metal as described above, for the next cycle Ts, the ladle 4 is tilted in the - direction to return to the neutral position, and the ladle 4 is started to retreat in the - direction. It is retracted to the position of the furnace 3 (retreat step S6).
At this time, as in the forward step S3, the ladle 4 is retracted at the first transport speed V1 halfway through the section from the forward limit to the position of the furnace 3, and then the ladle 4 is moved backward at the first transport speed V1. The ladle 4 can be retracted and stopped at the position of the furnace 3 at 2 transport speeds V2, but this is not the only option.

While the ladle 4 is waiting above the furnace 3 (cycle adjustment step S7), if a weighing command is issued, the ladle 4 is tilted in the - direction, and is lowered while retreating accordingly, The ladle 4 tilted to the entrance angle θ1 is caused to enter the melt surface 2A through the opening of the furnace 3 (furnace entry step S8). At this time, the ladle 4 enters the molten metal surface 2A to a predetermined depth until the molten metal surface 2A is detected by the molten metal surface detection sensor 8 (in-furnace molten metal surface detection step S01).
In the example shown in FIG. 6, the height of the ladle 4 when the ladle 4 starts to descend (at the start of step S8) is different from the height of the ladle 4 when the raising step S12 ends.
It is preferable that the adjustment of the cycle time is performed while the molten metal 2 is not stored in the ladle 4 as in step S7. While the molten metal 2 is stored in the ladle 4, for example, it is allowed to stop the ladle 4 at the end of its advance and wait for a pouring command. It is preferable to eliminate such waiting time as much as possible.
Thus, the cycle Ts of the hot water supply process is completed, and the next cycle Ts is started from the in-furnace melt level detection step S01.

As described above, the position of the molten metal surface 2B in the ladle 4 actually measured for each casting cycle in which the position of the molten metal surface 2B in the ladle 4 varies, and the actual Before the ladle 4 reaches the pouring position 53, the ladle 4 is tilted in the pouring direction (+ direction) up to the upper limit pre-tilt angle θ3 at which the molten metal 2 does not overflow from the ladle 4. can be done.
According to this embodiment, the operator does not need to set the pre-tilt angle θ3 in the control device 20, and the pre-tilt angle calculator 213 can automatically calculate the pre-tilt angle θ3 for each casting cycle. The casting cycle time can be reliably shortened compared to the case where the pre-tilt angle θ3 common to each cycle is uniformly determined.

In the control example shown in FIG. 6, the pouring step S5 is started based on the pouring command immediately after the ladle 4 stops at the pre-tilt angle θ3 in the pre-tilt step S4. On the other hand, in the other control example shown in FIG. 8, the preparation of the die casting machine is completed while the ladle 4 is tilted in the pre-tilt step S4. is reached, a tilting operation (pouring step S5) toward the pouring angle θ4 is performed.
Also in this case, the time required for the cycle Ts (cycle time) can be shortened by, for example, the time t1 shown in FIG. 8, as compared with the comparative example shown in FIG.

In addition to the above, it is possible to select the configurations described in the above embodiments or to change them to other configurations as appropriate without departing from the gist of the present invention.
As the molten metal surface position detection unit configured to detect the position of the molten metal surface 2B of the molten metal 2 stored in the ladle, in addition to the optical sensor 6 described above, for example, a level meter for detecting the liquid level of the molten metal 2 , or a distance meter or the like for measuring the distance to the hot water surface 2B can be used. Alternatively, the position of the hot water surface 2B may be obtained by image processing of image data of the hot water surface 2B captured by a camera.

It is preferable that the hot water surface position detector is not installed directly on the ladle 4, but installed on the rotation axis A3, which is the center of rotation of the ladle 4, like the optical sensor 6 in the above embodiment. Then, the same molten metal surface position detection unit can be used for detecting the molten metal surface position in the ladle in common for a plurality of ladles 4 corresponding to products. When the molten metal surface position detector is installed in the ladle 4, it is necessary to install a molten metal surface position detector in each of the plurality of ladles 4. FIG.
However, the target on which the hot water level detection unit is installed is not limited to the rotating shaft A3. For example, the optical sensor 6 can be installed on a support member existing at a predetermined location outside the water heater 1 .

In the above embodiment, the pre-inclination angle θ3 is calculated for each casting cycle on the premise of detecting the molten metal surface position in the ladle. It is also possible to automatically calculate the pre-inclination angle .theta.3 from the set value of the shape, molten metal weight, etc. by arithmetic processing using software, and use the pre-inclination angle .theta.3 for controlling the hot water supply process.

1 hot water supply device 2 molten metal 2A, 2B molten metal surface 3 furnace 4 ladle 4A spout 5 supply destination 6 optical sensor (molten surface position detection unit)
7 Mounting member 8 Hot water level detection sensor 10 Drive unit 11 First arm 12 Second arm 13 Pedestal 14 Ladle rotation mechanism 20 Control device (control unit)
21 Arithmetic processing unit 22 Storage unit 23 Motor driver 24 Amplifier 25 Encoder counter 51 Injection sleeve 51A Pouring port 52 Tip 53 Pouring positions 81, 82 Detection rods 81A, 82A Lower end 100 Trajectory 141 Motor 142 Encoder 211 Control signal source 212 Comparator 213 Pre-tilt angle calculator A1 Axis of rotation A1, A2, A3 Axis of rotation B1 Approach posture B4 Pouring posture L Axis line R1 Clockwise (+ direction)
R2 counterclockwise (minus direction)
S01 Furnace melt level detection step S1 Weighing step S11 First measure step S12 Ascent step S13 First measure step S14 Second measure step S15 Second measure step S2 Ladle melt surface position actual measure step S3 Forward step S31 First forward step S32 Second Forward step S4 Pre-tilt step S5 Pouring step S51 First pouring step S52 Second pouring step S6 Backward step S7 Cycle adjusting step S8 Furnace entering step t1 Time Ts Cycle v1 First tilting speed V1 First conveying speed v2 Second tilting speed V2 Second conveying speed θ1, θ1-5 Approach angle θ2 Metering angle θ3, θ3-5 Pre-tilt angle θ4 Pouring angle

Claims (6)

A hot water supply device for casting that supplies molten metal to a supply destination,
a ladle for pumping the molten metal from the furnace and pouring it to the destination;
a driving unit capable of transporting the ladle to a pouring position at the supply destination and tilting the ladle about a predetermined rotation axis;
a surface position detection unit configured to detect the surface position of the molten metal pumped out of the furnace and stored in the ladle;
Each casting cycle
Using the position of the molten metal surface detected by the molten metal surface position detection unit, the ladle is tilted prior to the arrival of the ladle at the pouring position by calculation based on the dimensions and shape of the ladle. A control unit that calculates a pre-tilt angle that is the upper limit angle at which the molten metal does not overflow from
A water heater for casting characterized by: The molten metal surface position detection unit includes an optical sensor that uses a laser beam,
The water heater for casting according to claim 1. The control unit
Using the position of the molten metal surface detected by the molten metal surface position detection unit and the ladle type related to the volume or shape of the ladle for calculating the pre-tilt angle,
The water heater for casting according to claim 1 or 2. A casting hot water supply method for supplying molten metal to a supply destination,
One cycle of casting is
a metering step of metering the molten metal from the furnace into a ladle;
a transporting step of transporting the ladle from the furnace to the destination;
a ladle surface position detection step of detecting the surface position of the molten metal pumped out of the furnace and stored in the ladle;
a pre-tilting step of tilting the ladle about a predetermined rotation axis prior to the ladle reaching the pouring position at the supply destination in parallel with the transporting step;
a pouring step of tilting the ladle at the pouring position to pour the molten metal from the ladle into the supply destination;
In the pre-tilting step,
A pre-inclination angle, which is the upper limit angle at which the molten metal does not overflow from the ladle, calculated by calculation based on the dimensions and shape of the ladle using the position of the molten metal surface detected by the step of detecting the molten metal surface position of the ladle. tilting the ladle to
A casting hot water supply method characterized by: In the ladle surface position detection step,
detecting the position of the surface of the molten metal stored in the ladle using a laser beam emitted to the surface of the molten metal;
The hot water supply method for casting according to claim 4. After reducing the conveying speed of the ladle in the middle of the conveying step,
initiating the pretilt step;
The hot water supply method for casting according to claim 4 or 5.

Images