JPH07106443B2 - Control method for water heater - Google Patents

Description

The present invention relates to a method for controlling a hot water supply device in a die casting machine or the like, and more specifically, there is no molten metal spillage or air entrainment of molten metal when pouring into a mold defining a cavity. The present invention relates to a method for controlling a hot water supply device, which enables pouring to be completed in a short time and cycle up of a molding process.

Generally, in a die casting machine, a hot water supply device is used in which a metal melted in a melting furnace, that is, a molten metal is pumped up by a ladle and the molten metal is automatically injected from a pouring port.

Therefore, a hot water supply apparatus according to this type of conventional technology is illustrated in FIG.

In the figure, reference numeral 2 indicates a hot water supply device, and the hot water supply device 2 is deformably pivoted on a frame 4 erected on a pedestal (not shown) via a ladle drive shaft 6 and an arm drive shaft 8. The link mechanism 10 is included. The quadrilateral link mechanism 10 includes an upper arm 12 and an auxiliary arm 14 pivotally supported by the ladle drive shaft 6, a ladle support arm 16 rotatably attached to one end of the upper arm 12, and the ladle support arm. Lower arm 18 connecting 16 and the auxiliary arm 14
And one end thereof is fixed to the arm drive shaft 8 and the other end thereof is composed of a drive arm 20 pivotally attached to the upper part of the lower arm 18. A ladle 22 for pumping up the molten metal is rotatably attached to the tip of the ladle support arm 16 via a shaft 24. On the other hand, the ladle drive shaft 6 is connected to a rotating shaft of a not-shown ladle drive motor. A sprocket (not shown) is provided at a required position of the ladle drive shaft 6, the upper arm 12, the ladle support arm 16 and the ladle 22, and a chain (not shown) is suspended on the sprocket to suspend the ladle drive motor. The ladle 22 is configured to rotate about the shaft 24 by driving. Further, an arm driving motor (not shown) is connected to the arm driving shaft 8. By rotating the arm driving motor, the quadrilateral link mechanism 10 is displaced and the ladle 22 is moved.

A case where the molten metal is supplied to the die of the die casting machine by the hot water supply device 2 will be described below. In FIG. 2, reference numerals a, b and c indicate the position of the ladle 22.

Therefore, in FIG. 2, a molten metal 32 is stored in the melting furnace 28. First, the ladle stopped at position a on the furnace
22 is lowered into the melting furnace 28 by the rotation of the arm driving motor and stopped at the position b. At position b, the third
As shown in FIG. 7A, the ladle 22 is rotationally displaced in the direction of arrow A in the figure with the rotation of the ladle drive motor. That is, when the ladle 22 tilts, the molten metal 32
Is introduced into Ladle 22. Then, the inclination angle of the ladle 22 with respect to the reference horizontal plane, that is, the molten metal pumping angle θ
_{When the} ladle 22 is raised in the direction of the position a shown in FIG. 2 while maintaining the value of ₁ , the excess molten metal 32 flows out during the raising operation as shown in FIG. Fixed amount of molten metal
32 remains. Therefore, the amount of the molten metal 32 to be pumped is determined by the ladle shape related to the ladle volume and the molten metal pumping angle θ ₁ .

Then, the ladle 22 stops at the position a and rotates in the direction of the arrow B to be horizontal in order to prevent spillage during the next moving process (see FIG. 3 (b), two-dot chain line). Then, the ladle 22 moves to the position c near the pouring port 36 of the mold 34. At this position, as shown in FIG. 3 (c), the ladle 22 is further rotated in the direction of arrow B from the horizontal state, whereby pouring is performed. In this case, the inclination angle of the ladle immediately before pouring is zero degrees. In this way, the tilt angle with respect to the horizontal reference plane is maintained at zero degrees, and pouring is started for the cavity of the mold 34 at a predetermined timing. After pouring at the position c, the ladle 22 rotates in the direction of arrow A and moves to the position a while maintaining the horizontal state, and the hot water supply cycle as described above is repeated.

By the way, from such a pouring standby state in the horizontal state of the ladle 22, when the molten metal is actually poured from the ladle 22 into the pouring port 36 after the pouring start signal is issued,
22 must tilt itself again. Moreover, at that time, it is necessary to prevent the spillage of water and the entrainment of air by rotating the ladle 22 in the direction of the arrow B at a relatively slow speed. However, if the pouring operation, that is, the tilting operation of the ladle 22 in the direction of the arrow B is performed at a constant low speed, a considerable time is required until the molten metal 32 in the ladle 22 starts to flow out. It

On the other hand, when the mold 34 is changed, the required amount of molten metal changes, so the ladle shape or the molten metal pumping angle θ ₁ must be changed. When the amount of molten metal in the ladle 22 is changed in this manner, the ladle 22 rotates in the direction of arrow B in FIG. 3 (c), and the tilt angle until the pouring is substantially changed is changed, Also, the time required to complete the pouring will change.

Therefore, in the conventional technology, the ladle 22 in the pouring process is used.
The tilting speed is controlled by opening and closing a limit switch by a dog arranged at a portion that rotates together with the ladle drive motor. Therefore, the tilting speed change pattern of the pouring operation is constant, which makes it impossible to perform the proper pouring according to the amount of hot water in the ladle 22. Moreover, it is possible to change the tilting speed change pattern by adjusting the dog for opening and closing the limit switch related to the pouring operation, but it requires skill to adjust the dog, and further, the dog adjustment However, it is necessary to temporarily suspend the hot water supply work, which is not preferable in terms of production efficiency. Further, in the pouring operation, as shown in FIG. 3 (c), when the ladle 22 tilts from the horizontal state and reaches a predetermined angle, pouring is substantially started.
It has also been pointed out that when the amount of molten metal in the inside is small, the inclination angle at the time when the pouring is started becomes relatively large, so that the pouring time is not shortened.

Therefore, as a result of earnestly researching and devising the present inventor,
Immediately before the start of the pouring operation, that is, when the ladle is tilted at a predetermined angle in the pouring standby state so that the pouring can be substantially performed in the shortest possible time, the pouring time can be shortened and It was found that suitable pouring can be performed without causing spillage or air entrainment of hot water, and the above inconvenience is eliminated.

Therefore, an object of the present invention is to reduce the pouring time of the hot water supply device in a die casting machine or the like, and automatically control to perform a suitable pouring operation of the hot water supply device, which can further improve the production efficiency. To provide a control method.

In order to achieve the above object, the present invention sets a molten metal pumping angle of a ladle for introducing molten metal into a ladle in a melting furnace, and then immediately before pouring of the ladle based on the molten metal pumping angle. Of the pouring standby angle is automatically specified, and the processing for tilting the ladle from the molten metal pumping angle to the pouring standby angle is performed.
By controlling the ladle drive means based on the calculation result, the control for continuously tilting the ladle to the pouring standby angle while the ladle is being conveyed from the melting furnace to the pouring position is completed. Further, the pouring is performed by tilting the ladle according to the molten metal tilting speed change pattern set based on the molten metal pumping angle.

Next, a preferred embodiment of the method for controlling a hot water supply device according to the present invention will be described in detail below with reference to the accompanying drawings in relation to a device that implements the method. In addition, this embodiment will be described using the hot water supply device of FIG. 1. In this case,
The same reference numerals as those disclosed in the above embodiments indicate the same components.

FIG. 4 is a schematic explanatory view of a control system for carrying out the present embodiment. In the figure, reference numeral 40 indicates a rotary encoder used as a tilt angle detecting means of the ladle 22. The encoder 40 is connected to a rotary drive shaft of a ladle drive motor that rotates the ladle 22. Therefore, when the molten metal is pumped up, a signal corresponding to the molten metal pumping angle θ ₁ is obtained. In FIG. 4, the ladle drive motor is indicated by reference numeral 42.

Therefore, the output signal from the encoder 40 is the interface
It is introduced into the CPU (central processing unit) 46 in the microcomputer which constitutes the Laddle operation selecting means 45 via 44 and an input port (not shown). A memory 48 is attached to the CPU 46, and the memory 48 is substantially the first data table.
It includes 47, a second data table 50, and a third data table 52.

In this case, the first data table 47 stores data for determining the molten metal pumping angle θ _{1 according} to the type of the ladle 22, and the second data table 50 stores the ladle tilt angle immediately before pouring the molten metal, that is, Data relating to the pouring standby angle θ ₂ (see FIG. 5) is stored, and further, pouring speed control data is stored in the third data table 52.

Therefore, the second data table 50 and the third data table 52 will be further described as follows.

In the present invention, when the ladle 22 is finally stopped at the position c in FIG. 6, the ladle 22 is positioned with an inclination angle of the pouring standby angle θ ₂ as shown in FIG. That is, the pouring standby angle θ ₂ is set to the ladle 22 while the ladle 22 moves to the position c.
Control 22 to gradually incline. In this case, the selected pouring standby angle θ ₂ largely depends on the amount of molten metal pumped up to the ladle 22. Cover the pouring standby angle θ ₂ ,
This is because if the amount of the molten metal pumped up is excessive, spillage will occur during the transportation of the ladle 22 or while waiting for the pouring. Therefore, the second data table 50 stores data for setting the optimum pouring standby angle θ ₂ in accordance with the output signal from the encoder 40 corresponding to the molten metal pumping angle θ ₁ .

Further, the third data table 52 stores data for determining the tilting speed change pattern of the pouring operation. For example, when the amount of molten metal in the ladle 22 is small, data for giving an instruction to start high-speed rotational displacement in the direction of arrow B in the latter half of the pouring operation at a relatively early timing is the CPU 46.
Read by. Various data corresponding to various ladle shapes are stored in the first to third data tables 47 to 52, the ladle shape is selected by an input device (not shown), and each data is selected by this selection signal. It goes without saying that this should be done.

On the other hand, a motor control circuit 56 is connected to the output side of the CPU 46 via an output port and an interface 54 not shown. That is, the motor control circuit 56 controls the drive of the ladle drive motor 42 according to the output signal from the ladle operation selection means 45.

Therefore, using the control system configured as above,
The case of performing the tilt control of 22 will be described below with reference to the flowchart of FIG. In this case, the flow chart shows that the pumping of the molten metal 32 is completed, the ladle 22 moves from the position a in FIG. 6 to the position c in FIG.
It shows just before trying to return to the position a.

Therefore, when the type of the ladle 22 is selected through an input device (not shown), the selection signal causes the molten metal pumping angle θ _{1 at} the position b in FIG. 6 of the ladle 22 to be read from the first data table 47. This signal is sent to the motor control circuit 56 via the interface 54. The ladle drive motor 42 is driven by the output signal of the motor control circuit 56, and the ladle 22 introduces the molten metal 32 therein at the molten metal pumping angle θ ₁ . A signal corresponding to the molten metal pumping angle θ ₁ of the ladle 22 is output from the encoder 40 and introduced into the CPU 46 via the interface 44 (STP1).
At this time, the data indicating the signal is stored in the register in the CPU 46, and the data for designating an appropriate pouring standby angle θ ₂ is selected from the second data table 50 corresponding to the data ( STP2). In this manner, when the data from the molten metal pumping angle θ ₁ to the pouring standby angle θ ₂ is selected, the CPU 46 moves the ladle 22 from the angle θ ₁ to the angle θ from the position a to the position c shown in FIG. The calculation processing for tilting control is performed on the control unit ₂ and the signal related to the calculation result is derived to the motor control circuit 56 via the interface 54. That is, the output from the ladle operation selecting means 45 is introduced into the motor control circuit 56, and the ladle 22 rotates in the direction of arrow B until the pouring standby angle θ ₂ is reached with the rotation of the ladle drive motor 42 (STP3). . In this case, as described above, step 3 is performed until the ladle 22 moves from the position a side to reach the position c, and by appropriately selecting the pouring standby angle θ ₂ as described above. Hot water spillage during movement of the ladle 22 is prevented. Following step 3, it is determined whether a pouring start command has been issued (STP4). When the pouring start is instructed, the data for designating the tilting speed change pattern corresponding to the molten metal pumping angle θ ₁ is selected from the third data table 52 based on the data in the register (STP5). Next, pouring is performed in accordance with the determined tilt speed accelerating pattern (STP6). Then, when the rotation of the ladle 22 in the direction of the arrow B for pouring is completed, a small amount of the molten metal 32 drops as a drop, and as it is the time until the drop stops is taken into consideration. In this state, a predetermined time is passed (STP7). Next, move the ladle 22 to the arrow A
To rotate the ladle 22 to the horizontal position (STP8).
In this way, when the pouring start is instructed in step 4, steps 5 to 8 are executed. After that, the ladle 22 is returned to the position a in FIG. Reach

On the other hand, if the start of pouring is not instructed in step 4, the elapsed time is counted and it is determined whether the allowable standby time has been exceeded (STP9). Therefore, if the counted time exceeds the allowable waiting time, the molten metal in the ladle 22
Since 32 has been cooled to the predetermined temperature or less, step 8 is executed subsequently to this, and the ladle 22 is again cooled by the melting furnace 28.
Move in. If the time counted in step 9 is within the allowable waiting time, there is no problem in the temperature state of the molten metal 32 in the ladle 22, and the process is repeated from step 4.

According to the present invention, the molten metal pumping angle θ _{1 is} thus
Since the pouring waiting angle θ ₂ and the tilting speed change pattern of pouring operation corresponding to the above are set, it is possible to perform pouring in a short time without causing spillage of molten metal during transportation or entrapment of molten metal during pouring. Can be done.

In addition, when the ladle 22 is changed and the ladle shape used in the hot water supply device 2 is changed, new data corresponding to the ladle shape is selected to appropriately match the ladle shape and the molten metal pumping angle θ _1. It is possible to control the pouring operation.

Furthermore, in the present embodiment, the pouring waiting angle θ ₂ and the tilting speed change pattern are determined by the second data table 50 and the third data table 52. However, the pouring angle θ ₁ of the molten metal is a suitable pouring temperature. The same effect as described above can be obtained even if an arithmetic expression for determining the standby angle θ ₂ and the tilt change speed pattern is obtained and the CPU 46 executes the arithmetic expression.

According to the present invention, the pouring time is shortened because the ladle is tilted and conveyed in the pouring operation direction to such an extent that the pouring does not spill while moving to the pouring position, and the pouring standby angle and the tilting speed. The change pattern is appropriately selected according to the amount of molten metal pumped up by the ladle, so that molten metal can be poured without spillage of molten metal and air entrainment of molten metal. Furthermore, fine control can be performed according to the ladle shape and the molten metal pumping angle, and it is not necessary to adjust the position of the dog for the limit switch as in the conventional case. Therefore, since the pouring operation is automatically controlled, the operation of the hot water supply device becomes extremely easy. After all,
By applying the present invention, it is possible to achieve the effect that suitable control of the hot water supply device can be achieved and the production efficiency can be further improved.

[Brief description of drawings]

FIG. 1 is a schematic side view of a hot water supply apparatus, FIG. 2 is an explanatory view when hot water is supplied by the hot water supply apparatus of FIG. 1, and FIG. 3 (a) is a diagram when introducing molten metal into the ladle of FIG. A schematic cross-sectional view of the ladle, FIG. 3 (b) is a schematic cross-sectional view when pumping up the molten metal after the state shown in FIG. 3 (a), and FIG. 3 (c) is subsequent to FIG. 3 (b). FIG. 4 is a schematic explanatory view of a control system for carrying out the method for controlling a hot water supply device according to the present invention. FIG. 5 is a diagram for explaining a method for controlling a hot water supply device according to the present invention. Fig. 6 is a schematic cross-sectional view during pouring, Fig. 6 is an explanatory view in the case of controlling the tilt angle of the ladle using the method of the present invention, and Fig. 7 is a flowchart of the method of controlling the hot water supply device of the present invention. 2 …… hot water supply device, 10 …… quadrilateral link mechanism 12 …… upper arm, 14 …… auxiliary arm 16 …… ladle support arm, 18 …… lower arm 20 …… drive arm, 22 …… ladle 24 …… axis , 28 …… Melting furnace 32 …… Melt, 34 …… Mold 36 …… Pouring port, 40 …… Encoder 42 …… Laddle drive motor 44 …… Interface, 46 …… CPU 47 …… Data table, 48… … Memory 50, 52 …… Data table 54 …… Interface, 56 …… Motor control circuit

Continuation of the front page (56) Reference JP-A-57-103774 (JP, A) JP-A-58-184061 (JP, A) Actually opened 50-121013 (JP, U) Actually opened 50-121014 (JP , U)

Claims (1)

[Claims] 1. A molten metal pumping angle of a ladle for introducing molten metal into a ladle in a melting furnace is set, and then a pouring standby angle immediately before pouring of the ladle is automatically set based on the molten metal pumping angle. The ladle is controlled from the melting furnace by performing arithmetic processing for tilting the ladle from the molten metal pumping angle to the pouring standby angle, and controlling the ladle drive means based on the arithmetic result. Completed the control of continuously tilting the ladle to the pouring standby angle while being conveyed to the pouring position,
Furthermore, the method of controlling a hot water supply apparatus is characterized in that the pouring is performed by tilting the ladle according to a tilting speed change pattern for pouring, which is set based on the molten metal pumping angle.