JPH05138332A - Device and method for spraying water in drum shaker - Google Patents

Abstract

PURPOSE:To eliminate the breakage of a thermocouple and to reduce variation of the moisture in recovered sand by arranging the thermocouple in discharged sand and controlling spraying quantity of cooling water from plural water spraying pipes with the relation of 2 to the nth power to each pipe. CONSTITUTION:The sand 9 discharged from the drum shaker 1 is dropped on the belt conveyor 10 through grid opening of a screen 12 for sand screening and conveyed as the recovered sand 10. The thermocouple 2 is embedded in the recovered sand 10 to measure the temp. of the recovered sand 10 and the measured temp. is converted to a voltage and the electric signal is transmitted to the thermo-controller 3. The electric signal corresponding to the measured temp. is transmitted to a sequencer 14 through the thermo-controller 3 and the water spraying quantity is selected from plural steps, which are different with the relation of geometric series of 2, according to this signal through the sequencer 14. By operating a solenoid valve 6 corresponding to this water spraying quantity, the water spraying quantity from each water spraying pipe 5 is controlled and further, the water spraying quantity is controlled according to the quality of the molding sand and this wt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprinkler for a drum shaker and a sprinkling method for inserting a sand mold and a casting cast into the sand mold and crushing the sand mold to separate the casting from the sand mold.

[0002]

2. Description of the Related Art A conventional drum shaker watering method is shown in FIG.
As shown in, a thermocouple 42 is attached to the inlet side of the drum shaker 41 to convert the temperature of the sand 49 in the drum shaker 41 into a voltage, which is connected to the temperature controller 43 via the compensating lead wire 44.
When the sprinkling start temperature is set by the temperature controller 43 and becomes higher than the set temperature, the solenoid valve 4 of the sprinkling pipe 45 mounted in the drum shaker 41 by the sequencer 48.
6 is opened, cooling water is made to flow to the water sprinkling pipe 45, and water is sprinkled from the water sprinkling nozzle 47 attached to the water sprinkling pipe 45. The supply of the cooling water to the sprinkling pipe 45 is divided into several stages according to the temperature of the sand 49, and in a certain temperature range T1 to T2, water is supplied to one sprinkling pipe 45 at 15 liters / dispersed water, and the higher temperature range T2 to T3. In the higher temperature range T3 to T4, water is supplied to the two water spray pipes 45 and 30 liters / dispersed water is supplied, and in the higher temperature range T3 to T4, water is supplied to the three water spray pipes 45 and 45 liters / dispersed water. Table 1 shows such a relationship that the number of sprinkling pipes 45 for supplying water increases as the temperature rises.

[0003]

[Table 1]

However, in the drum shaker 41, the hot casting 48 and the sand 49 that have been unframed from the sand mold are mixed, and the thermocouple 42 directly contacts the casting 48, so the temperature is measured as a temperature higher than the actual temperature of the sand 49. Sprinkle more water than necessary,
The thermocouple 42 may break. Further, since the temperature of the sand 49 is measured at the inlet side of the drum shaker 41 and the temperature of the recovered sand 50 discharged to the outlet is not measured, this state continues for a long time even when the above-mentioned abnormality occurs. Clogging or dust occurs.

The water spray pipes 45 in the drum shaker 41 all have the same amount of water, and the solenoid valve 4 of the water spray pipe 45 has the same amount.
The amount of water sprinkled is controlled by opening and closing 6. Therefore, in order to increase the number of stages of controlling the amount of water spray, the number of water spray pipes 45 must be installed.

Furthermore, since the temperature of the sand 49 is measured and water is sprayed so that the water content in the sand, which is correlated with the water, is constant, if the amount of the sand 49 changes, the water content of the recovered sand 50 will change. The fluctuation of is large.

[0007]

The problem to be solved by the present invention is that the thermocouple 42 is in direct contact with the casting 48 and is measured as a temperature higher than the actual temperature of the sand 49, or the thermocouple 42 is broken. Moreover, since the temperature of the sand 49 is measured at the inlet side of the drum shaker 41, the fluctuation of the water content of the recovered sand 50 becomes large. Furthermore, in order to increase the number of stages for controlling the amount of sprinkling, the number of sprinkling pipes 4 is increased by that number.
5 is required, and when the amount of sand 45 in the drum shaker 41 is large or small, the fluctuation of the water content of the recovered sand 50 becomes large.

[0008]

According to the present invention, in order to solve the above problems, a thermocouple is installed in the sand discharged from a drum shaker, and the sprinkling amount of cooling water in each sprinkling pipe is 2. The above problem is solved by controlling the amount of cooling water sprinkled by the weight of the molding sand and the weight of the casting in the drum shaker.

[0009]

[Function] By installing a thermocouple in the sand after it is discharged from the drum shaker and separated from the casting, breakage of the thermocouple is eliminated and feedback control is performed to automatically judge whether the amount of water sprinkling is too large or too small. Returning to the optimum amount of water sprinkling The amount of cooling water of the sprinkling pipe is set to a geometrical series relationship with a series of 2 so that the number of stages of water sprinkling can be increased and finely adjusted without increasing the number of sprinkling pipes. ,
By controlling the amount of cooling water sprinkled by the weight of sand and casting in the drum shaker, fluctuations in the water content of the recovered sand were reduced.

[0010]

1 is a system diagram showing a first embodiment of the present invention, FIG. 2 is a sectional view of a drum shaker 1, and FIG. 3 is a system diagram showing a second embodiment of the present invention. .. In FIG. 1, the drum shaker 1 has a cylindrical shape and has an inlet side 1a.
Is installed so as to be slightly higher than the outlet side 1b, and is vibrated by an unillustrated vibrator. Drum shaker 1
A plurality of sprinkling pipes 5 provided with sprinkling nozzles 7 are installed in the upper part of the inside, and the sprinkling pipes 5 are connected to a water source via a solenoid valve 6 that can be opened and closed. The amount of cooling water sprinkled in each sprinkler pipe is 2 to the n-th power (where n is 1, 2,
It is different because it is the number that changes to 3, 4) times. For example, 1
If the amount of water sprayed from the first water spray pipe is 4 liters / minute,
The amount of water sprayed from the second water pipe is 8 liters / minute, the amount of water sprayed from the third water pipe is 16 liters / minute, and the amount of water sprayed from the fourth water pipe is 32 liters / minute.

At the rear of the outlet side 1b of the drum shaker 1, a grid-shaped sand removing screen 12 is installed on the upper surface of the oscillating conveyor 11, and below the sand removing screen 12, an inclined belt is provided. Conveyor 1
The lower end of 3 is installed, the recovered sand 10 is transported on the belt conveyor 13, and the thermocouple 2 is installed in a state of being buried in the transported recovered sand 10. The thermocouple 2 is the compensating lead wire 4.
It is connected to the temperature controller 3 via. The temperature controller 3 sends an electric signal corresponding to the temperature measured by the thermocouple 2 to the sequencer 14, and the sequencer 14 selects a sprinkling amount of 0 to 15 stages according to the electric signal. A relay 15 opens and closes the solenoid valve 6 by a signal from the sequencer 14.

Next, the operation of this embodiment will be described. Sand mold and casting 8 inserted into the drum shaker 1 from the inlet side 1a
The sand mold is crushed by the vibration of the drum shaker 1 and the casting 8
Is separated into sand 9 and moves to the outlet 1b side together with the casting 8 and drops onto the sand removing screen 12. Sand 9 from the grid of the sand removing screen 12 becomes collected sand 10 that does not fall on the belt conveyor 10, and the casting 8 moves to the oscillating conveyor 11 and is transported to a predetermined place. The recovered sand 10 on the belt conveyor 11 is transported to a predetermined place. Since the thermocouple 2 is buried in the recovered sand 10 on the belt conveyor 13, the temperature of the recovered sand 10 is measured and an electric signal is sent as a voltage to the temperature controller 3 via the compensation lead wire 4. The temperature controller 3 transmits an electric signal corresponding to the temperature measured by the thermocouple 2 to the sequencer 14, and the sequencer 14 selects a sprinkling amount of 0 to 15 stages according to the electric signal, and the sprinkling amount stages 0 to 15 are selected. By converting the numbers up to to a binary number, a 4-digit number consisting of 0 and 1 is obtained. The numbers correspond to the solenoid valves 6 of NO1, NO2, NO3, NO4 in order from the bottom, and the solenoid valve is "closed" when it is 0 and "open" when it is 1, and the solenoid valve 6 of NO1 is 4 The NO2 solenoid valve 6 is connected to the sprinkling pipe 5 for sprinkling water of 1 liter / min.
Is connected to the sprinkling pipe 5 for sprinkling water of 8 liters / minute, the NO3 solenoid valve 6 is connected to the sprinkling pipe 5 for sprinkling water volume of 16 liters / minute, and the solenoid valve 6 for NO4 is 32 liters / minute. It is connected to a sprinkling pipe 5 for sprinkling water. Table 2 shows the above sprinkling conditions as shown in Table 2.
0 temperature range (T1 or less, T1 to T2, T2 to T3
16 or more sprinkling conditions can be obtained. In the table, “◯” indicates “open” and “x” indicates “closed”.

[0013]

[Table 2]

Next, a second embodiment of the present invention will be described with reference to FIGS. 2 and 3, the same reference numerals as those in FIG. 1 indicate the same devices, and therefore their explanations are omitted. The drum shaker 1 is equipped with a vibration exciter 17 that generates vibration by rotating the unbalanced weight 17a.
An accelerometer 18 is attached at a position opposite to. The accelerometer 18 measures the amplitude of the drum shaker 1 vibrating by the vibrator 17. The measured value is transmitted as an electric signal to the control amplifier 20 via the lead wire 19, amplified by the control amplifier 20 and transmitted to the sequencer 14. The sequencer 14 controls the water sprinkling amount by using the amplitude as the weight of the casting 8 and the sand 9 in the drum shaker 1 as described below. For example, when the temperature of the sand 9 is 90 ° C. and the weight is 4 tons, the water sprinkling amount is 12 liters. / Minute,
When the weight of the sand 9 is 7 tons, the amount of water sprayed is 7/4 times, that is, (12 liters / minute) × (7/4) = 21 liters / minute.

Next, the casting 8 and sand 9 in the drum shaker 1
The calculation of the weight V added with will be described. Amplitude and weight W
The relationship shown in Formula 1 is established between (the weight of the drum shaker 1 + the weight of the casting 8 + the weight of the sand 9), and the vibration force and the rotational speed are known values determined by the vibration exciter 17. W (weight of drum shaker 1 + weight of casting 8 + weight of sand 9) can be calculated. Since the weight of the drum shaker 1 is a known value, the weight V to which the casting 8 and the sand 9 are added can be calculated by the formula shown in Formula 2.

[0015]

[Equation 1]

[0016]

[Equation 2]

[0017]

As described above, according to the present invention, since the thermocouple is buried in the recovered sand, there is no direct contact with the casting and the thermocouple is not broken.
Since the temperature of the recovered sand is measured and water is sprayed, fluctuations in the water content of the recovered sand are reduced, and it is possible to increase the number of stages for controlling the amount of sprayed water without increasing the number of sprinkling pipes. I was able to reduce it.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a drum shaker 1.

FIG. 3 is a system diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a conventional method for watering a drum shaker.

[Explanation of symbols]

 1 Drum Shaker 2 Thermocouple 5 Sprinkling Pipe 7 Sprinkling Nozzle 8 Casting 9 Sand 17 Vibrator 18 Accelerometer

Claims (5)

[Claims] 1. When a sand mold and a casting cast into the sand mold are inserted into an oscillating cylindrical drum and the sand mold is crushed to separate the casting and the sand mold, when the sand temperature becomes higher than a set value. A sprinkler for a water shaker, wherein a thermocouple is installed in the sand discharged from the drum shaker. 2. When a sand mold and a casting cast into the sand mold are inserted into an oscillating cylindrical drum and the sand mold is crushed to separate the casting and the sand mold, when the sand temperature becomes higher than a set value. A sprinkler for a drum shaker that sprinkles water, comprising a plurality of sprinkler pipes each having a different sprinkling amount of cooling water. 3. The sprinkling amount of the cooling water of each sprinkling pipe is different in a relation of 2 to the n-th power (where n is a number that changes to 1, 2, 3, 4) times. Sprinkler for the described drum shaker. 4. When a sand mold and a casting cast into the sand mold are inserted into an oscillating cylindrical drum, the sand mold is crushed to separate the casting and the sand mold, and when the sand temperature becomes higher than a set value. A method for watering a drum shaker, characterized in that a watering amount of a drum shaker for watering is controlled by the weight of casting sand and weight of the casting. 5. The method of watering a drum shaker according to claim 4, wherein the amplitude of the drum shaker is measured to calculate the weight of the foundry sand and the foundry product.