SU561622A1 - The device for correcting the dose of metal in the car casting under pressure - Google Patents

Description

one

The invention relates to foundry, in particular to the automation of the dosing of metal in an injection molding machine.

A device for adjusting the dose of metal to an injection molding machine is known with the aid of changing the dispensing time by the actuating unit depending on the stroke of the extruder, its piston of the machine, determined by the press residual measurement unit 1.

Dosing time is corrected if the piston stroke is different from the specified one. If the piston stroke is greater than the specified one, the dose is less than the required one and the dosing time is increased. If the lorshn stroke is less than the set point, the dose is greater than the required one and the dosing time in the next cycle is reduced. The correction signal is issued by the device’s time relay, which is turned on synchronously with the start of pressing.

A disadvantage of the known device is the appearance of a false correction signal when the piston moves at a different speed or if the time relay is inaccurate. In addition, it is possible to issue a false sigpal for correction due to a dose change as a result of an accidental process deviation (instantaneous voltage change; release of metal from the mold; overflow of a part of metal

when poured into a cup, which is eliminated in the next cycle, and dose adjustment is not required.

The purpose of the invention is to increase the reliability of dose adjustment. This is achieved by the fact that the device additionally contains a memory block and a time delay block, the output of which is connected to the input of the memory block through the measuring unit of the magnitude of the press residue

the output of which is associated with the execution unit.

FIG. 1 shows a block diagram of the proposed device for correcting the dose of metal in an injection molding machine; in fig. 2-

memory block diagram.

In the machine 1 is cast under pressure serves a dose of metal from the dispenser 2. On the pressing piston 3 of the machine is cast under pressure is a controlling element 4, the position of which is relatively shaded in FIG. 1, the region of a given value of the press residue determines the course of the norn. If element 4 is within the region, the dose does not require correction. If controlling

the element did not reach the shaded area, then the course of the norsn is less than the specified and the dose is greater than the required, and if it has passed, then the dose is less than the specified. Sensors 5 and 6 control smaller and larger piston strokes of block 7 for measuring the size of press residual, included by element 4, are located at the boundaries of the permissible values of the press residue. Block 7 consists of two elements: sensors 5 and 6 at the entrance, apparatus 8 and 9 controls, included with less (unit 8) and more (unit 9) during the piston.

At the output of block 7, depending on the position of element 4 with respect to sensors 5 and 6 and their operation, there can be three types of signals (see Table 1), where the following signals are received:, notation: "+ -included,

disabled.

Table 1

The voltage f / i to the control devices 8 and 9 of the measurement unit 7 is supplied from the time delay unit 10. Block 10 is turned on by the casting crystallization time relay 11, which simultaneously sends a signal to open the mold of the injection molding machine. The voltage Ui from block 10 through control units 8 and 9 of measurement block 7 is fed to the input of memory block 12. The output signal from the memory unit 12 is directed to

Signal type block 7

II III

The signal formed after the first pressing is memorized by element 16, except for the signal "O, which is not memorized and at which the subsequent pressing is considered the first. The second pressing signal and the first pressing signal remaining in the element memory are fed to the element at element 17. The device operates as follows. The metal in the pressing chamber of the machine 1 25 is cast under pressure poured from the dispenser

an executive unit 13, which introduces a dose adjustment to the control unit 14 of the dispenser 2.

The memory unit 12 consists of signal forming, storing, matching, pick-up and output (respectively) elements 15, 16, 17, 18 and 19. The filament of the element 16 and the whole subsequent circuit is carried out by the voltage f / 2. In element 15, the signals shown in Table 1 are formed. 2

table 2

Signal in element 15

The first press in the press fitting scoop

+ + 00

match. From the coincidence element, the output signal received (see Table 3) goes to the signal pickup element 18, which turns off the memory element 16, and simultaneously to the output element 19. When the element 16 is turned off, the subsequent pressing is considered first.

Table 3 2. Dose value determined by priming time. After the metal pouring is completed, the pressing piston 3 is turned on and the casting

pressed in. In this case, the monitoring element 4 on the mouth occupies a position relative to the sensors 5 and 6 of the control unit 7 for measuring the magnitude of the press residue, which allows judging the press residue and dose values. The output signal from block 7 is supplied after the end of crystallization of the casting. The crystallization time relay 11 switches on the time-delay unit 10 and at the same time sends a signal to open the mold of the maschine 1 cast under pressure. The time during which the voltage is applied by unit 10 to control units 8 and 9 and memory unit 12 is significantly less than the time from the signal to turn on the hydraulics and start the movement of the mold. After switching on the time delay unit 10, a signal appears on the output of the measurement unit 7, the type of which depends on the position of element 4 (see Table 1). Depending on the output signal of block 7, a signal is formed in the element 15 of memory block 12 (see Table 2). Output signal to

Claims (1)

1. The patent of Germany Aib 1287756, cl. 31 b2, 17/30, 1969. -K f-c: - / j |.,; i, lp / - / I 1    V, I ± UPJ  ; / ± /. G. ± /.o &five Ijl m / g , ./, 2 L 15 Vi. (rig 2