SU1224094A1 - Device for controlling moulding sand mouldability - Google Patents

Description

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The invention relates to a foundry and can be used in mixing departments of foundries.

The purpose of the invention is to increase the yield of high-quality molding sand by moisture at elevated temperature of the waste mixture at the inlet of the mixer by expanding the range of thermal compensation of the device.

FIG. 1 shows a block diagram of the device in FIG. 2 is a block diagram of the adjustment.

The device consists of a sampler 1, a formability sensor 2 containing a vibrating channel 3 with a narrow slit 4 and a wide adjustable slit 5, each of which has photo sensors 6 and 7, a regulating slit plate 8 and a mechanism 9 for moving the regulating plate, a dispenser 10 of water supplying water into the mixer 11 and having a valve 12 coarsely metering and an exact metering valve 13, a temperature sensor 4 of the position sensor 15, a displacement actuator 16, a control unit 17 and a control unit 8 whose inputs are connected to the outputs of photosensors 6 and 7, and Odes - with valves 12 and

13, the movement mechanism 9 is associated with the movement actuator 16 and the control plate 8, which in turn is associated with the position sensor 15. The electrical output of which is connected to one of the inputs of the slot width adjustment unit 17, the other input of which is connected to the output of the sensor.

14 temperatures, and the exits - with a drive 16 for moving the control plate.

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The control unit 17 consists of input drivers 19 and 20, threshold circuits 21-23, adder 24, coincidence circuits 25 and 26, and power amplifiers 27 and 28. The driver 19 is connected to the output of temperature sensor 1, and the driver 20 input is connected to the sensor output

15places The output of the driver is connected to the input of the threshold circuit 21.

and with one of the inputs of the adder 24, the other input of which is connected to the output of the imaging device 20. A direct output of the adder 24 is connected to the input of the threshold circuit 22, the output of which is connected to one of the inputs of the circuit 25

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a match, the other input of which is associated with the output of the threshold circuit 21 and with one of the inputs of the circuit 26 of coincidence. An inverse adder output is associated with. input threshold circuit 23, the output of which is connected to another input of the circuit 26 match. The outputs of circuits 25 and 26 are connected via power amplifiers 27 and 28 to displacement drive 16.

The device works as follows.

The mixture selected by the sampler 1 from the mixer 11 is prepared, fed to the internal flow sensor 3 of the forming sensor 2 and, waking up through slots 4 and 5, through the lower collecting chute goes to the photosensors 6 and 7 (to the photosensor 6 the mixture flows through the slit 4, and the photo sensor 5 receives the mixture, spilled from through slots 4 and 5).

If the humidity of the mixture fed to the mixer decreases, then from mixer 1I to the formeability sensor 2 an under-humidified mixture enters, which is requested through both slits 4 and 5 and blocks the light fluxes of photosensors 6 and 7. At the same time, signals from photosensors 6 and 7 control unit 8 opens valves 12 and 13 and water flows into the mixer with maximum flow. As it becomes wet, the mixture becomes less free-flowing and does not spill through the narrow slit 4. At the same time, by a signal from the photo sensor 6, the control unit 18 closes the coarse metering valve 12 (a valve with a higher flow rate) and the mixture is adjusted to the required formability by means of. supplying water to the mixer through the precision metering valve 13 (the water consumption valve), which is closed by the control unit 18 upon a signal from the photo sensor 7 when the mixture spills over the wide slit 5 of the vibrating channel 3.

If the temperature of the waste mixture at the input of the mixer exceeds the permissible value (40 ° C), the threshold circuit 21 is activated and outputs a signal to the inputs of the matching circuits 25 and 26. The adder 24 subtracts the magnitude of the signal U of the temperature sensor 14 from the magnitude of the signal and ,,, the position sensor 15 (gap width sensor 5, determined when the atom and the difference

(5, and (yits-i) ,,

If threshold scheme 21 is turned on (the temperature of the spent mixture exceeds the allowable value), and the difference iU is positive and exceeds the set value, then threshold scheme 22 of the control unit 17 triggers and outputs a signal to the input of circuit 25. In this case, the signals at the input of circuit 25 through the amplifier 27 it turns on the drive 16 of the interchange 11, which at the same time rotates in the direction of increasing the width of the slit 5 of the formability property of the sensor 2 until the value of the difference becomes less than the release threshold of the circuit 22, gap 5 width leads to an increase .prosypani mixture therethrough, and hence to feed the mixer additional quantity of water which is vaporized during transportation of the finished mixture to a place of use, and this temperature compensation is achieved.

If the temperature of the spent mixture decreases, but remains above the permissible value (40 ° C) and the difference iU of the signals at the output of the adder 24 becomes negative and exceeds in absolute value the specified value 2 i09 /,

Then, the threshold circuit 23 is triggered and the signal to the input of the circuit 26 coincides. In this case, there is a coincidence of the signals at the input of the circuit 26, which through the amplifier 28 turns on the drive for moving down the width of the slit 5 of the formability sensor. In this case, the slit width is reduced until

10, the difference of the signals (in absolute value) becomes less than the release threshold of the circuit 23.

If the temperature is waste

15 the mixture exceeds the fy value, and the difference between the signals at the output of the adder is less than the threshold of operation of the circuits 22 and 23, or if the temperature of the mixture is below the allowable value (does not exceed 40 ° C), then the inputs of the circuits 25 and 26 The movement drive 16 is hereby disconnected.

25 The positive effect created by the device is to increase the yield of the moisture-quality molding sand at the spent-temperature temperature.

30 at the inlet of the mixer as a result of an increase (up to 130 s) of the upper limit-range of the thermal compensation of the device. In addition, reduced marriage forms and pour.

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Claims (2)

I. DEVICE FOR REGULATING THE FORMABILITY OF THE MIXTURE prepared in the mixer, consisting of a formability sensor containing a vibratory tray with two transverse slots of different widths, under each of which there is a photosensor, a water dispenser supplied to the mixer, containing two parallel channels with coarse and precise metering valves, temperature sensor and control unit, the inputs of which are connected to the photosensors of the formability sensor, and the outputs, respectively, with coarse and precise metering valves, characterized in that, in order to the output of the high-quality molding sand at an elevated temperature of the spent mixture at the inlet of the mixer by expanding the range of thermal compensation of the device, it is equipped with a block for regulating the width of the second slit, a vibrator tray of the formability sensor, a position sensor and a displacement drive, and the formability sensor is additionally equipped with a plate regulating the width of the second slit and a movement mechanism a control plate mechanically connected to a position sensor and a movement mechanism, which in turn is connected to a displacement drive, wherein the displacement drive is connected to the outputs of the width control unit of the second slit, the vibrator tray of the formability sensor, one of the inputs of which is connected to the output of the temperature sensor, and the other to the output of the displacement sensor. 2. The device according to π. ί, characterized in that the second slot width control unit of the formability sensor vibrator tray contains two input signal conditioners, three threshold circuits, an adder, two matching circuits and two power amplifiers, the outputs of which are the outputs of the unit whose input is -. are the inputs of the shapers, the output of one of which is connected to the input of the first threshold circuit and to one of the inputs of the adder, and the output of the second shaper is connected to the second input of the adder, the direct output of which through the second threshold circuit is connected to one of the inputs of the first coincidence circuit, the other input of which connected to the output of the first threshold circuit and to one of the inputs of the second coincidence circuit, the other input of which is connected through the third threshold circuit to the inverse output of the adder. SU „„ 1224094