JPH0592253A - Device for automatically scooping molten metal - Google Patents

Abstract

PURPOSE:To prevent hot-dipping of a ladle by arranging a temp. sensor between the end part of a lifter and the tip part of an electrode for detecting molten metal surface and forcedly returning back the lifter after the temp. sensor detects the molten metal surface. CONSTITUTION:The lifter 2 descends the ladle 1 and when the electrode sensor 3 detects the molten metal surface A', the descending is stopped. When the electrode sensor 3 executes the erroneous detection and the lifter does not stop and further descends, the measuring temp. is gradually risen as the temp. sensor 4 approach the molten metal surface A', and at the time of becoming the prescribed temp., the descending of the lifter 2 is stopped and the lifter is forcedly returned upward to the original position and also an alarm to display that the electrode sensor 3 is in some trouble is displayed. The hot-dipping accident of the ladle can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic hot water pump used when a molten metal such as aluminum is automatically supplied to a casting machine.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, in an automatic hot water pump of this type, a rail L is provided above a casting machine a and a holding furnace b in which molten metal is stored. An elevator 2 equipped with 1 is suspended on the rail L to reciprocate between the casting machine a and the holding furnace b, and is vertically moved at the positions of the casting machine a and the holding furnace b.

The reciprocating motion of the elevator 2 is performed by a rail L (not shown).
The ladle 1 is vertically moved by a drive source (not shown) provided in the elevator 2 to vertically move the elevator frame 2a. The rotation when the ladle 1 draws the molten metal A in the holding furnace b and the rotation when pouring the molten metal A in the ladle 1 into the receiving port a ′ of the casting machine a are as shown in FIG. First, the rotating arm 2b provided at the lower end of the elevating frame 2a is rotated. That is, the ladle 1 is fixed to a rotating arm 2b, and the rotating arm 2b is connected to a chain 2c driven by a reversible motor provided in the elevator 2 via a sprocket 2d.

At the end of the elevating frame 2a, a pair of electrode rods 3a whose tip is located above the lower end of the ladle 1,
An electrode sensor 3 composed of 3b is provided, and when one of the tips of the electrode sensor 3 comes into contact with the molten metal A,
Elevating frame 2a via both electrodes 3a, 3b and ladle 1
The current flowing therethrough is detected to detect the molten metal surface A'and the lowering stop position of the elevating frame 2a is controlled. A plurality of electrode rods is used as a spare because the electrode rods are oxidized and conduction failure is likely to occur and detection mistakes are likely to occur.
This is because at least one of the electrode rods can be used for detection. The ladle 1 and the elevating frame 2a electrically act as ground.

[0005]

However, in the above-mentioned conventional automatic hot water pump, the electrode sensor detects the descent stop position of the lifting frame (elevator) to adjust the immersion depth of the ladle into the molten metal. However, there is a drawback in that the lifting arm lowers more than necessary due to the detection failure of the electrode sensor, and the so-called drip immersing occurs in which the lifting frame with the fixed ladle is immersed in the molten metal.

When the lifting frame is immersed in the molten metal, the bearing portion of the rotating arm is melted, or the molten metal penetrates into the rotating mechanism such as the sprocket, which not only requires replacement of the rotating arm, but also The inconvenience that the operation of the casting machine had to be stopped for several hours for repair such as replacement had occurred.

The cause of the detection failure of the electrode sensor is that the electrode rod is placed in the high temperature atmosphere of molten metal and is oxidized to deteriorate the electrical continuity, or oxide such as aluminum adheres to the electrode rod. The electrical conduction state may be lowered, the electrical conduction state may be maintained, the electrode rod may be damaged, or the lead wire of the electrode rod may be broken.

Therefore, the present invention has been made to solve the above-mentioned drawbacks, and an object thereof is to provide an automatic hot water dispenser which does not cause dripping even if a detection failure of an electrode sensor occurs. ..

[0009]

In order to achieve the above object, the device of the present invention is provided with a ladle at the end of the elevator via a rotary arm, and the tip is located below the rotary arm. In an automatic hot water dispenser that provides an electrode rod and rotates the ladle when the electrode rod detects the molten metal surface, the molten metal surface between the end of the elevator and the tip of the electrode rod is A temperature sensor for detecting the temperature is provided, and when the temperature sensor detects the molten metal surface, a forced return means for stopping the descending movement of the elevator and forcibly returning is provided. The temperature sensor is a thermocouple.

[0010]

In the above structure, the temperature sensor detects the molten metal surface located between the tip of the electrode rod and the lower end of the elevator.
Then, when the temperature sensor detects the molten metal surface, the descending movement of the elevator is stopped by the forced return means, and the elevator is lifted to the original position and stopped.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example shown in FIGS. 4 and 5 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 1, reference numeral 4 denotes a chromel-alumel type thermocouple sensor, whose tip position is above the tip position of the electrode sensor 3 and below the lower end of the elevating frame 2a, and is located on the elevating frame 2a. It is fixed. The chromel-alumel type thermocouple sensor is made of an alloy of nickel and chromium (chromel) and a nickel alloy of manganese, aluminum and silicon (alumel) at 1200 ° C.
Widely used for temperature measurement up to a degree.

FIG. 2 is a block diagram showing the electrical construction of the apparatus of this embodiment. In the figure, 5 is a thermometer to which the electromotive force of the thermocouple sensor 4 is input, and the output of this thermometer 5 is shown. Is connected to the well-known controller C which is a sequence controller or a programmable controller. The controller C is also configured to receive the conduction state of the temperature sensor 3 and send an output signal to a drive source (not shown) that moves the elevating frame 2a up and down. The controller C has various output signals for moving the elevator 2 between the casting machine a and the holding furnace b and various inputs and outputs for controlling the casting machine a.
The output signal is present but omitted since it is not directly relevant to the description of the invention.

Next, the control operation of the apparatus of this embodiment will be described with reference to the flow chart of FIG.

Now, the molten metal A of the aluminum alloy is placed in the holding furnace b.
Is stored, and the temperature of the molten metal is 690 ° to 710.
It shall be kept at ℃. In this case, the temperature 40 mm (Δd in FIG. 1) above the molten metal surface A ′ is 80 ° to 100 ° C.
Is. Then, suppose that the elevator 2 (elevating frame 2a) descends and moves to draw hot water (Yes at step 100).
Hereinafter, the step will be referred to as S. ), The descending movement is continued until the tip of the electrode sensor 3 contacts the molten metal surface A '(S).
102 denial).

When the electrode sensor 3 contacts the molten metal surface A '(S
(Yes at 102), the descending movement of the elevator 2 is stopped, the ladle 1 is rotated to perform hot water pumping, the elevator 2 is then raised, and further moved to the casting machine a side for pouring (S10).
6).

By the way, when the descending movement of the elevator 2 is continued even if the electrode sensor 3 penetrates into the molten metal surface A '(S1).
04 negative), the temperature measured by the thermometer 5 of the thermocouple sensor 4 is
The controller C is input after exceeding the set temperature (for example, 200 ° C. at 20 mm above the molten metal surface). That is, as the tip of the thermocouple sensor 4 approaches the molten metal surface A ′, the measured temperature (80 ° to 100 °) when the tip of the electrode sensor 3 contacts the molten metal surface A ′.
℃) gradually increases. When the tip of the thermocouple sensor 4 approaches the molten metal surface A ', the thermometer 5 is instantaneous (within 1 second).
Shows a large measured value exceeding 200 ° C., and when the temperature exceeds 200 ° C., a signal indicating that the thermocouple sensor 4 is turned ON is input to the controller C (Yes in S108), and the controller C causes the elevator 2 to descend. It is output so as to stop the movement (S110). As a result, contrary to the above, the elevator 2 is forcibly output to return to its original position (home position) and an alarm is issued to notify the staff (S11).
2).

Therefore, in the apparatus of this embodiment, even if the descending movement of the elevator 2 is not stopped due to the detection failure of any one of the pair of electrode sensors 3, it can be detected and stopped by the thermocouple sensor 4. The inconvenience of the ladle 1 being soaked in lumps is prevented.

Moreover, since the staff member is informed of the malfunction of the electrode sensor 3, the staff member can quickly repair the electrode sensor 3.

In the apparatus of the above embodiment, the molten metal surface A'located between the tip of the electrode sensor 3 and the lower end of the elevating frame 2a is detected by the thermocouple sensor 3. However, this detection is not limited to this. This type of sensor may be used, for example, one applying ultrasonic waves or radiant heat. However, the thermocouple sensor as in this embodiment is advantageous because it can withstand a high temperature atmosphere.

[0021]

According to the apparatus of the present invention, since the molten metal surface existing between the tip of the electrode sensor and the lower end of the elevator is detected by the sensor, the detection sensor can stop the descending movement of the elevator. It is possible to effectively prevent the drenching of ladle. Further, when the sensor is a thermocouple sensor, it has a feature that it can be detected by being sufficiently adapted to a high temperature atmosphere.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of an apparatus according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a control operation of the apparatus of the embodiment.

FIG. 4 is a schematic configuration diagram of a conventional device.

FIG. 5 is a detailed view of a ladle portion.

[Explanation of symbols]

 1 Ladle 2 Elevator 2b Rotating Arm 3 Electrode Sensor (Electrode Bar) 4 Thermocouple Sensor (Temperature Sensor) C Controller (Forced Return Means) A'Melted Surface

Claims (2)

[Claims] 1. A ladle is provided at the end of an elevator via a rotating arm, and an electrode rod whose tip is located below the rotating arm is provided. When the electrode rod detects a molten metal surface, In an automatic hot water dispenser that rotates a ladle to draw hot water, a temperature sensor that detects a molten metal surface between the end of the elevator and the tip of the electrode rod is provided, and the temperature sensor detects the molten metal surface. An automatic hot water dispenser characterized in that a forced return means for stopping the descending movement of the elevator and forcibly returning the elevator is provided. 2. The automatic hot water dispenser according to claim 1, wherein the temperature sensor is a thermocouple.