SU1191174A1 - Apparatus for controlling mould temperature - Google Patents

Description

The invention relates to casting production, in particular, to devices for thermostating metal casting molds, and can be applied in casting under pressure in: chill mold, under low pressure.

The purpose of the invention is to improve the quality of castings by increasing ^{1 of the} upper level of the heating temperature of the coolant. ^ten

FIG. G shows a device for temperature control li-. regular forms; in fig. 2 - device heat exchanger; in fig. 3 - device supercharger; in fig. And the unit reversible coolant supply device.

The device contains a mold 1 (see Fig. 1) with a heat exchange cavity 2, two identical heat exchangers 3 and 4, two identical superchargers 5 and 6, a heating and cooling control system. Heat exchangers 3 and 4 are interconnected through the cavity 2 of the mold 1. The heat transfer to the heat exchanger 3 and 4 are connected by means of conduits 7 and 8 superchargers 5 and 6. blowers 5 and 6, a heat exchanger 3 and 4, the cavity 2 of the casting heat odds ^- 30 us 1 and pipelines 7-10 form an open-loop coolant circuit, to which superchargers 5 and 6 alternately pump the coolant in opposite directions. 35

Each heat exchanger 3 and 4 (see Fig. 2) contains cavities 12 separated by a partition 11 and a refrigerant GB and coolant. · The cavity 40 of the cooler, in turn, is divided by a partition 14 into a cavity

15 supply of the cooler and the cavity 16 of the outlet of the cooler reported

among themselves by means of a pipe - 45

coolers 17. Heaters 19 are fixed in the lid 18 of the heat exchanger. In the coolant supply zone 20 and the coolant outlet zone 21, flow dividers 22 and 50 23 are installed .. The heat exchanger body 24 is equipped with a heat-insulating coating 25, has taps 26 and 27 for connecting respectively to the superchargers 5 Or 6 and to the cavity 2 heat-55 mold exchange 1. Cavity

16 coolant outlet connected to

drain 28 (see Fig. 1). .

Each supercharger, for example supercharger 5 (see Fig. 3), is made in the form of a cylinder 29, which is provided with a piston 30 separating the force cavity 31 from the cavity 32 of the heat carrier. The supercharger is equipped with a hydraulic piston 33 for displacing the piston 30, which is installed in the upper part of the supercharger, and its rod 34 is located in the power strips. These 31 and rests end 35 on the piston 30. The control input 36 and the outlet 37 of the supercharger are made respectively in the cavity 38 of the specified plunger and in the cavity 32 of the coolant. The outer surface of the cylinder 29 is provided with thermal insulation coating 39 '. Outputs 37 (see Fig. 1) of blowers 5 and 6 are connected to field 13 of the coolant of heat exchangers 3 and 4. Power cavities 31 of blowers 5 and 6 are interconnected by pipe 40 and connected to compressed air line 41. Pressure-compressed air applied in the power cavities 31 to the pistons 30 creates an overpressure in the open coolant circuit to raise the upper level of the heating medium temperature. The set pressure is maintained if the temperature of the heated coolant exceeds its boiling point under normal conditions. The value of this pressure does not affect the amount of force spent by the plunger 33 to move the pistons 30 when pumping coolant, since the power cavities 31 of both blowers are connected to each other and the movement of the pistons 30 is accompanied by the movement of air, and not additional compression. The magnitude of the pressure of compressed air supplied to the power cavities is determined by the specified heating temperature and the properties of the coolant.

The heating and cooling control system combines a temperature sensor 42, a mode unit 43, a heating control unit 44, a cooling control unit 45, a purge unit 46, and a reversible coolant supply unit 47.

The mode block 43 selects according to the temperature of the mold 1 device operation mode: “Heating”, “On”

four

“Or-“ Cooling. ”· The input of the mode unit 43 is connected to the sensor 42 of the temperature of the mold 1, the outputs - with the heating control unit 44, the coolant reversing unit 47, the cooling control and purge blocks 45 and 46.

The heating control unit 44 serves to turn on or turn off heat exchangers 3 and 4 on the heaters 19 as commanded by the mode unit 43, and also to turn off the heaters 19 in case of emergency overheating of the heat transfer medium. .

The cooling control unit 45 and the purge unit 46 are connected in parallel and connected to the cooler supply cavities 15 of the heat exchangers 3 and 4.. These units operate alternately to supply respectively coolant or compressed air to. cavity 15 for supplying heat exchangers cooler 3 and 4. '

• Block 47 of reversible supply of heat carrier 25 has two outputs connected by pipelines 48 and 49 to control inputs 36 of blowers 5 and 6. This block provides, in heating or cooling modes, alternately supplying working fluid (oil) in the cavity 38 of hydraulic plungers 33 (see Fig. 3) the movement of the pistons 3.0, the rods 34 of which alternately press on the pistons 30, displacing the coolant to the heat exchangers 3 or 4.

Block 47 reversible coolant supply contains the element OR 50 (see Fig. 4), multivibrator 51, keys 52 and 53, as well as the distributor 54. At the same time, the inputs of the OR 50 element are the inputs of block 47 of the reverse coolant supply (see Fig. 1 and '4) connected to lines 55 and 56. In turn, the outputs of the distributor 54 are the outputs of the block 47 of the reverse flow of coolant.'

Multivibrator 51 serves to alternately switch keys 52 and 53. The length of time during which the specified keys ¹ are in the on state is set by the time constant of the multivibrator 51. Switching keys 5.2 and '53 strictly at the moment pistons 30 reach (see Fig. 3) pumped

Lei 5 and 6 (see. Fig. 1) extreme positions are not mandatory. The positive effect is achieved both in the case of switching 5 keys with some reflection of the moment of approaching their extreme positions, and in the case of idle pistons for some time in extreme positions when the keys are late in switching keys.

In the initial state of the device, the pistons 30. and the rods 34 are: in the supercharger 5 in the upper position, in the supercharger 6 in the lower position. Signals 15 are absent at inputs 15 of unit 47 of the reversible supply of coolant, both keys 52 and 53 are turned off, electromagnets 57 and 58 of distributor 54 are also turned off, both outputs of the distributor 54, and consequently, block 47 of the reversible flow of coolant are cut off. The coolant circuit, including the cavity 32 of the blowers 5 and 6, is filled with coolant. The power cavities 31 of the blowers 5 and 6 communicate with the compressed air line 41, the latter creating an overpressure in the coolant circuit, heating and cooling the switch off '

cheny ·

The signal of the temperature sensor 42 installed in the mold 1. The device provides one of three modes: "Heating", "Off"

35 or "Cooling".

When the temperature of the mold 1 is below the set temperature range, the mode unit 43 commands the line 55 to heat and the block 44 '

40 heating control includes heaters 19 of heat exchangers 3 and 4, which increases the temperature of the coolant '.

The command of the block 43 of the mode simultaneously enters through the line 56 into the block '

47 reverse flow of coolant, powered by a multivibrator 5.1, switching keys 52 and 53, the solenoid 57 is turned on, distribute 50 La .54. At the same time, the working fluid flows from the pressure pipeline 59 through the distributor 54 to the pipeline 48 and then to the control input 36 of the supercharger 5. At the same time, the control input 36 of the supercharger 6 through the pipe 49 and the distributor 54 communicate with the drain 60.

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Under the action of the rod 34 piston

30 moves down, displacing the coolant from the cavity 32 of the coolant, the compressor 5, into the heat exchanger 3 and further along the pipeline 7 into the cavity 2 of the heat exchange of the mold G. At the same time, the coolant flows from the cavity 2 of the heat exchange of the mold 1 to the heat exchanger 4, from the latter to the supercharger 6 , 'moving its piston 30 th through the last rod 34 to the upper position. After expiration of the time determined by the time constant of the multivibrator 51, the keys 52 and 53 are switched, the switch 53 and the electromagnet 58 are turned on, and the working fluid enters through the distributor 54 and the pipe 49 into the control input 36 of the supercharger 6. At the same time, the supercharger 5 of the same name communicates with the drain 60. As a result, the coolant is pumped through the heat exchange cavity 2 of the mold 1 from the heat exchanger 4 to the heat exchanger 3. The heat carrier in the heat exchange cavity 2 of the mold 1 moves in two directions x by successively supplying the working fluid in the cavity 38 of the plungers moving. The piston continues until the temperature of the mold 1 reaches the lower level of the set temperature range. After that, the block 43 mode removes the command to

Heating and heating control unit 44 shuts off heaters 19 of heat exchangers 3 and 4. Block 47 of the reversible coolant supply turns off the supply of working fluid to the blowers 5 and 6, the forced movement of the coolant through the heat exchange cavity 2 of the mold stops.

If in the process of producing castings, the temperature of the mold 1

. will reach the upper level of the set temperature range, then the mode unit 43, according to a signal from the temperature sensor 42, includes, via line 61, blocks 47 and 45 of the reverse coolant supply and cooling control. Block 47 carries out the reverse feeding coolant poochered- _g hydrochloric supply hydraulic fluid via conduits 48 and 49 * in the superchargers 5 and 6, which is pumped through the coolant teplo.obmennuyu cavity 2 of the mold 1 from one exchanger to the other and back, just as it Occurs when the proposed device is in heating mode. '

The print cooling control unit 45 supplies coolant through pipelines 62 and 63 into cavity 15 for supplying cooler of heat exchangers 3 and 4 and then through tubular coolers 17 to cavity 6 of coolant outlet, from where coolant flows into drain 28. Coolant takes heat from heat carrier to heat exchangers 3 and 4. Passing when pumping through the heat exchange cavity 2 of the mold 1, the coolant cools the mold 1.

When the temperature of the mold 1 drops to the lower level of the set temperature range, mode unit 43 removes the cooling command, cooling control unit 45 shuts off the supply of cooling fluid to the heat exchangers. 3 and 4, and the purge unit 46 supplies compressed air through lines 62 and 63 for a time sufficient to remove residual coolant from the cavities 12 of the cooler of heat exchangers 3 and 4.

The device for regulation allows, by heating the coolant under an excess pressure, to raise the upper level of the heating temperature of the coolant, for example, to raise it by 40-80 ° C at a pressure in the coolant circuit of 0, -0.5 MPa. Due to this, the difference between the temperature required for the mold and the temperature to which the heat carrier can be heated is reduced. When this is achieved a stable thermal regime of the mold, reduced castings castings.

1191174

119,174

FIG. g

, ^ mg.4

Claims (2)

DEVICE FOR REGULATING THE TEMPERATURE OF THE CASTING FORM, equipped with two heat exchangers, two superchargers, each of which is equipped with a piston separating the coolant cavity from the power cavity, the heating and cooling control system containing two reversible heat transfer unit with two outlets, different in that the quality of castings due to an increase in the upper level of the heating medium heating temperature; each supercharger is equipped with a hydraulic piston displacement piston, the rod of which is installed in the power cavity of the supercharger and rests end on the piston, while the hydraulic piston movement of the pistons is connected by its control inputs to the outputs of the reversible coolant supply unit, and the power cavities of both superchargers are connected to each other and equipped with a means for connecting to the compressed air line. 511 ,,,, 1191174 one 1191174 2