SU1435388A1 - Method of regulating the speed of forming in pressure casting - Google Patents

Abstract

The invention relates to the production of castings by injection molding on machines with a cold pressing chamber and is intended to control the speed of pressing. The purpose of the invention is to stabilize the hydrodynamic mode of filling the mold. The essence of the invention is that when metal is poured from furnace 4 into weight metering unit 5, mass measurement unit 6 fixes the mass of dose. Comparison unit 8, comparing the readings of unit 6 and task block 7, determines the magnitude and sign of the dosing error. Block 9 calculates the magnitude and the sign of the correction of the switching coordinate, the signals of which are fed to the inputs of the reversible counters 12, 13. The latter form the corrected value of the coordinate of the moment of switching the movement modes of the press piston. 1 il.

Description

The invention relates to the production of castings by the method of injection molding on machines with a cold pressing chamber.

The purpose of the invention is to stabilize the hydrodynamic mode of filling the mold.

The drawing is a schematic diagram of a device implementing the method.

The device comprises a press chamber 1, a press piston 2 connected to the stem 3 of the press cylinder, a distributing furnace 4, a weight metering device 5 with a mass measurement unit 6, a dose mass setting unit 7, a comparison unit 8, a correction value calculation unit 9, blocks 10 and 1G are phase change setting adjusters of phase III and II, reversible counters 12 and 13, gauge 14 coordinates of the press piston, line 15 of the coordinate measurer associated with stem 3, hydraulic valves 16-18 of movement modes.

The functional dependence of the actual coordinate of the moment when the pressing speed is switched on the magnitude of the metal dose deviation is described by the ratio

Hfakt Hzad -f- K (- At the hall

K-L- cm / kg; l R p

where R is the radius of the pressing chamber, cm; p is the density of the liquid metal,

KG / CM;

 tf fact - actual mass of the dose, kg; U / - given (calculated) mass of the vine, kg;

Hzal is the given coordinate of the path of the moment when the pressing speed is switched;

The hfak-realizable moment coordinate is the switching speed of compression.

The device works as follows. : When pouring liquid metal from a distribution; an accurate furnace 4 into a weight metering unit 5; the measurement records the mass of the dose in the scoop of the processor 5. The comparison unit 8, comparing the readings of unit 6 and task block 7, determines the magnitude and sign of the metering error. Block 9 calculates the magnitude and sign

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the correction of the switching coordinates, which are sent to the inputs of the reversible counters 12 and 13.

At the beginning of each cycle, the signals of the blocks 10 and II of the settings are recorded in the counters 12 and 13 according to the signal of the measurement unit 6. At the end of the dosing cycle, from block 9 signals are sent to the summing or subtracting inputs of counters 12 and 13, depending on the correction sign, and 0 form in them the corrected value of the coordinate of the moment when the press-drive movement modes are switched.

When the ruler 15 of the gauge of the coordinates of the path associated with the rod 3 moves, the output of the measuring 14 coordinates generates a signal proportional to the current coordinate of the path that goes to the subtractive inputs of counters 12 and 13. When the values of the current coordinate of the path coincide with the corrected value of Neither the coordinates located in the counters 12 and 13 are given signals on the hydraulic hammers switching the mode of movement of the press piston. Thus, the correction of the coordinates of the switching modes (speeds) of the press piston is performed depending on the actual dose of the metal poured in the press chamber of the injection molding machine and the stability of the hydrodynamics of the mold filling mode is ensured by adjusting the speed of the press pistons

Using the method of controlling the speed of the pressing piston will reduce the scrap of castings by 10-15%, improve the quality of castings by stabilizing the hydrodynamics of filling the pressplp.

Isorethorne formula

The method of controlling the pressing speed during injection molding, which includes measuring the mass of the dose supplied to the press chamber, and the positional change in the speed of the pressing piston, characterized in that, in order to stabilize the hydrodynamic mode of filling the mold, the magnitude of the deviation of the dose mass from of a given value and in proportion to the deviation magnitude, the coordinate of the change in the speed of the pressing piston is corrected.

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Claims (1)

Claim A method for controlling the pressing speed during injection molding, including measuring the mass of the dose supplied to the press chamber, and the positional change in the speed of the pressing piston, characterized in that, in order to stabilize the hydrodynamic regime of filling the mold, the deviation of the dose mass from the set value is determined and is proportional the deviation value is corrected by the coordinate of the change in speed of the pressing piston. Compose. And A. Abrosimov