JP2867133B1 - Hot water supply method of cold chamber type die casting machine - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a simple structure, to easily set and change the amount of hot water supply, to improve the accuracy of hot water supply, to prevent dripping of molten metal and mixing of oxides, and to prevent air entrapment during pouring. Provide a hot water supply system. SOLUTION: A gooseneck type pouring pump 2 is provided in a molten metal pot 1 and its discharge port is injected to a cold chamber type die casting machine DM via transfer tubes 3a, 3b provided with a heating device 4 at a portion outside the molten metal pot. Connect to the sleeve 7. A servo motor 14 for driving the pouring piston 9 of the gooseneck type pouring pump 2, a servo driver 16 for driving the servo motor, and an arithmetic and control unit 15 are provided, and a predetermined stroke is set according to the hot water supply weight set in the arithmetic and control unit 15. Only the pouring piston 9 is driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply system for a cold chamber type die casting machine.

[0002]

2. Description of the Related Art Conventionally, as a hot water supply system of a cold chamber type die casting machine, a ladle type hot water supply system in which molten metal is drawn from an electric furnace with a ladle and poured into a sleeve inlet, and an electromagnetic pump type hot water supply in which molten metal is supplied by an electromagnetic pump. There are a hot water supply method and a hot water supply method that uses an impeller pump.However, the generally used ladle hot water supply method contains oxides and cannot prevent air entrapment during pouring.
There is a problem that the oxide adhering to the surface of the ladle during transportation is mixed into the product, and a defective product is easily generated. In addition, hot water supply of Mg is impossible with this method.

On the other hand, the electromagnetic pump type hot water supply system and the impeller pump type hot water supply system have been applied to the hot water supply of Mg in some embodiments. However, when the inside of the tube is transferred, impurities and the like accumulate in the tube and the resistance in the tube changes. Not satisfy the accuracy of hot water supply. Further, there is a disadvantage that the electromagnetic pump and the impeller pump are expensive.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention has a simple structure, can easily set and change the amount of hot water supply, can improve the accuracy of hot water supply, and can prevent dripping of molten metal and mixing of oxides. It is an object of the present invention to provide a hot water supply system in which air is not trapped during pouring.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a gooseneck-type pouring pump provided in a molten metal pot, and a discharge port of the pump is provided at a portion outside the molten metal pot. Connected to the injection sleeve of a cold chamber type die casting machine via a transfer tube with
A servo motor for driving the pouring piston of the gooseneck pouring pump is provided, the piston diameter of the gooseneck pouring pump is D, the effective piston stroke is S, the inner diameter of the transfer pipe is d, and the actual hot water is measured from the reference level. When the distance to the surface is Δ1, the intake port waste stroke is L, the transfer pipe cavity volume is V ₁ , and the required hot water supply volume is V ₀ , the feed shaft of the pouring piston is expressed by the following equation.

[0006]

(Equation 2)

The hot water supply method for a cold chamber type die casting machine is characterized in that hot water is supplied by driving the servo motor by a stroke obtained by adding a suction port waste stroke L to an effective piston stroke S determined by the following formula.

[0008]

Since the present invention is a hot water supply system using a piston pump driven by a servomotor, it is possible not only to easily set and change the amount of hot water supply but also to improve the accuracy of hot water supply as compared with the conventional method. it can. Further, since the transfer to the sleeve injection port of the die casting machine is performed in a state where the air is shut off from the outside air, there is no mixing of oxides, and the entrapment of air during pouring is prevented, so that the quality of the product can be improved.

[0009]

1 is a sectional view showing the configuration of a hot water supply apparatus to which the present invention is applied. 1 is a molten metal pot, 2 is a gooseneck type pouring pump provided in the molten metal pot 1, and 3a is a molten metal pot. Transfer pipe 3b is connected to an injection sleeve 7 of a cold chamber type die casting machine DM via a pouring joint 5, and a transfer pipe having a coil heater 4 on the outside, 5 is a pouring joint having a sheath heater 6, Reference numeral 8 denotes an injection piston of a die casting machine (not shown).

The pouring piston 9 is configured to move up and down by driving a feed nut 12 screwed to a screw rod 11 (feed shaft) connected to a piston rod 10 by a servo motor 14 via a speed reducer 13. The servo motor 14 is driven by a servo driver 16 controlled by a signal from the arithmetic and control unit 15. 17 is a tacho generator.

Reference numeral 18 denotes a level sensor of an oscillating type, an electromagnetic type or the like, 19 a proximity switch for detecting the rising end of the screw rod 11, 20 a proximity switch for detecting the falling end of the screw rod 11, and detection of the proximity switch 19. The signal is used for position reset, and the detection signal of the proximity switch 10 is used for safety.

Next, the handling and operation will be described. First, the amount of hot water required by the cold chamber type die casting machine DM is set by operating the digital switch 21 provided on the panel of the arithmetic and control unit. The set hot water supply amount is digitally displayed on the display unit 22.

When the start switch 23 is turned on,
The servo motor 14 is started via the servo driver 16, and according to a sequence shown in a flowchart described later,
The screw rod 11 is rotated via the speed reducer 13 and the feed nut 12, the pouring piston 9 is lowered by a predetermined stroke, and hot water is supplied to the injection sleeve 7 of the die casting machine DM via the transfer pipe 3 and the pouring joint 5. Subsequently, the injection piston 8 is driven to supply hot water into the cavity of the die casting machine DM.

Here, the piston diameter of the pouring pump 2 is D,
The effective piston stroke is S, the inner diameter of the transfer pipes 3a and 3b is d, and the distance from the reference level 25 to the actual level 25 'is Δ.
1, when the useless stroke of the suction port 26 is L, the volume of the transfer pipe cavity is V ₁ , and the required hot water supply volume is V ₀ ,

[0015]

(Equation 3)

The following holds. Therefore, the stroke SX of the pouring piston 9 necessary for performing the required hot water supply is equal to the effective stroke S determined by the above equation and the suction part useless stroke L
(SX = S + L).

FIG. 2 is a graph showing the movement of the lower surface 27 of the pouring piston 9. The rising end is detected by the proximity switch 19, the falling end is detected by the proximity switch 20, and the movement position is detected by the tacho generator 17. You.

[0018]

[Outside 1]

In the apparatus of this embodiment, when the operator operates the digital switch 21 to set the casting weight, the arithmetic and control unit 15 calculates the stroke based on the above-mentioned equation, and sets the pouring piston 9 in accordance with the result. The control is such that a predetermined pouring amount is supplied to the injection sleeve 7 and then the injection piston 8 is operated to supply a predetermined amount of hot water to the die casting machine DM.

FIG. 3 is a flow chart for performing the operation shown in FIG.
Not only the hot water supply control but also the supply of raw materials to the molten metal pot 1 and the control of the injection piston 8 and the die casting machine D
It goes without saying that the control of M is also performed.

The molten metal pot 1 is covered with a cover 26, and is constructed so that an inert gas such as SF ₆ is injected into the molten metal pot 1 to prevent generation of oxides.

[0022]

As is clear from the above description, the hot water supply system according to the present invention is a piston pump type, so that high accuracy of hot water supply can be obtained, and the setting and change of the hot water supply amount can be easily performed. In addition, since the liquid is transported in the pipe, there is an effect that there is no dripping of molten metal or mixing of oxides, and that air is prevented from being trapped during pouring. In addition, since the structure is simple, it can be provided at a low cost, and can be used for hot water supply of Mg which has been increasing in demand in recent years.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a hot water supply apparatus to which the present invention is applied.

FIG. 2 is a graph showing a movement of a lower surface of a pouring piston in the embodiment.

FIG. 3 is a flowchart of arithmetic control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molten pot 2 Gooseneck type pouring pump 3a, 3b Transfer pipe 4 Coil heater 5 Pouring joint 6 Seeds heater 7 Injection sleeve 8 Injection piston 9 Pouring piston 10 Piston rod 11 Screw rod 12 Feed nut 13 Reduction gear 14 Servo motor 15 Arithmetic controller 16 Servo driver 17 Tach generator 18 Hot water level sensor 19 Proximity switch for detecting rising end 20 Proximity switch for detecting falling end 21 Digital switch 22 Display unit 23 Start switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B22D 17/30 B22D 17/32 B22D 35/00 B22D 39/02

Claims (1)

(57) [Claims] 1. A gooseneck-type pouring pump is provided in a molten metal pot, and a discharge port thereof is connected to an injection sleeve of a cold chamber type die casting machine via a transfer pipe provided with a heating device outside of the molten metal pot, A servomotor for driving the pouring piston of the gooseneck pouring pump is provided, the piston diameter of the gooseneck pouring pump is D, the effective piston stroke is S, the inner diameter of the transfer pipe is d, and the reference level to the actual level Is Δ1, the suction port waste stroke is L, the transfer pipe cavity volume is V ₁ , and the required hot water supply volume is V ₀ , the feed shaft of the pouring piston is
The following equation A hot water supply method for a cold chamber die casting machine, characterized in that hot water is supplied by driving the servo motor by a stroke obtained by adding an intake port waste stroke L to an effective piston stroke S determined by: