SU1533830A1 - Method and apparatus for controlling die casting machine - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to a foundry, namely, the control of an injection molding machine. The goal is to increase the productivity of the process. The composition of the lubricant is adjusted depending on the effort to push the casting and remove the rods from the mold. Measuring the forces on the ejector allows one to stabilize the process of ejection of castings and to increase the productivity of the process of injection molding. At the same time, the control of the gap between the molds makes it possible to exclude false information about the quality of lubrication of the surface of the mold in the presence of plume and, in addition, to exclude metal firing from the mold. 2 sec. f-ly, 1 ill.

Description

The invention relates to foundry, namely to the lubrication of the mold during injection molding.

The aim of the invention is to increase the productivity of the process.

The drawing shows a diagram of a device for lubricating molds cast under pressure.

The device contains tanks 1 and 2, respectively, for a lubricant and a diluent, connected via pipelines 3 to pumps 4 and electrically controlled chokes 5 to tanks 6 through tanks. 6 tanks are connected to pneumatic network 7 through electrically controlled valves 8, and pipelines to pumps 9 and through electrically controlled valves 10 with nozzles 1-1, which are also connected to the pneumatic net 7 via electrically controlled valves 12,

The sensors 13 for measuring the extraction force of the rods installed in the mold 14 under pressure are electrically connected to the control unit 15, to which, in addition, the casting ejection sensors 16 mounted on the ejector 17, the sensor 18 for controlling the gap between the molds, the sensor 19 are connected of the initial start-up, the sensor 20 of the moment of opening, digging the form and the sensor 21 of the moment of clearing the half-molds

The determination of the extraction forces of the rods is carried out, for example, by measuring the magnitude of the pressure drop in the pressure and discharge cavities of the power cylinders using Sapphire-22DI transducers or by changing the linear dimensions of the rods as a result of their extension (DSTB-S-060K force sensors

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WITH

with

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with

The ejection force sensors 16 are castors of the DSTB-C-060 type, mounted on the ejector 17.

As a sensor 18 for monitoring the gap between the half-molds, a DSTB-C-060 type force sensor can be used, mounted on a fixed half-form and equipped with a rod in contact with the mobile half-form when they are closed,

As the control unit 15, for example, a CM-1800 computer equipped with an appropriate DCS may be used.

The initial startup sensor 19 is an electromechanical button.

The form-opening moment sensor 20 is a contact relay of the type RPU, which is supplied in parallel with an electromagnet of activation of the hydraulic actuator on the opening of the form.

The semi-mold closure moment sensor 21 is, for example, a non-contact position sensor of the BC type.

I

The method is carried out as follows.

At the start of operation of the casting machine, a lubricant with a high content of lubricant in the diluent is prepared by applying a signal from the initial start-up sensor 19 to the control unit 15. The control unit 15 provides temporary control effects on the electrically operated chokes 5 for the preparation of lubricants of the desired composition for the mold and the rods in the tanks 6. The mixing of the lubricant in the tanks 6 is performed by opening the electrically controlled valves 8 of the pneumatic network 7.

At the moment of closing of the half-molds (recorded by the sensor 21 of the moment of closing the half-form) before zapivka metal in the press chamber of the casting machine, the signal characterizing the size of the gap between the hull forms (d), from the sensor 18 controlling the gap between the half-forms enters the control unit 15. When the gap exceeds the technologically permissible value (d m) due to the presence of a plug in the mold connector, the control unit 15 gives a message about the necessity to stop the casting machine cycle to remove

laziness oblo. After removal, the mold lubrication is performed manually. Otherwise, the cycle continues, and at the time the signal is received by the control unit 15 from the mold opening sensor 20 after the end of the casting crystallization, the existence

Ublo in the form connector. In view of the occurrence of additional efforts to push the casting out in the presence of flash, in this case the composition of the lubricant of the mold is not changed for the next cycle, the remaining 15 liters remain the same, and the composition of the lubricant is determined only for the rods. In the absence of a blockage, the control unit 15 for a period of time from the start of opening the mold is sufficiently 20 to break and remove the casting,

periodically measures the signals from the ejection force sensors 16 of the casting and the rod extraction force sensors 13, determines the highest total value of the measured forces on the ejector (F,) and the highest extraction efforts for each (central, lateral, vertical) rod (Fz, F3, F4) and

Zo compares them with the maximum allowable force values (F) and the highest MQKC

large previous values of forces (F; nDftA, i 1,2,3,4). If for

35

before any element F- F; MC | KC,

the composition of the lubricant for it the next

the cycle is chosen corresponding to the original. In the absence of the previous value (F, - units) for any element, the composition of the lubricant for it Q is not changed for the next cycle. Otherwise, the composition of the lubricant is not changed. F - F are not, 05, and choose the composition of the lubricant with large Sozdatg. t. 45 by the use of diluent at - - LIA, 05.

 before

After measuring and determining the composition of the lubricant for the mold and the rods for the next cycle, the control unit 15 delivers control actions to the electrically controlled valves 10 to supply lubricant to the nozzles 11, while simultaneously turning on the electrically controlled valves 12 of the pneumatic network 7, the mold is lubricated and rods, after which the control unit 15 issues control actions on electric controls 50

Led chokes 5 for the preparation of an already defined lubricant composition for the next casting machine cycle.

The order of operation of the control unit 15 on subsequent cycles is maintained. Stopping the casting machine during the opening of the rubbing mold is not performed, as it may be removed along with the casting.

Example. Die casting molds are manufactured by a device that includes a lubricator from the KOM 1.25 O kit, mounted on an AT711B08 die casting machine with a 6 MN locking force. In the manufacture of an aluminum casting, for example, an electric motor casing, for example, force ejection sensors DSTB-C-060, installed under the ejector. The determination of the extraction forces of rods is carried out, for example, by measuring the magnitude of the pressure drop in the pressure and discharge cavities of the power cylinders using Sapphire-22DI converters.

After the mold is heated to 230, a lubricant of the initial composition is prepared (by pressing the initial start button) by mixing four parts of the lubricant and one part of the diluent.

The working range of the ejection force of the casting is set as follows.

After stabilization of the mode of operation

the rod extracted from the central part of the casting, the extraction force is 35 kN, and for the lateral part 10 kN. Then, the amount of diluent in the lubricant is gradually increased while measuring the extraction force of the rods. Dilution leads to values at which no reliable

0 extraction rods. The extraction forces of the rods are measured, which are 78 and 17 kN, respectively. The maximum extraction forces of the rods are the forces constituting

0.8 from the limit, i.e. respectively 62.4 and 13.6 kN.

Further lubrication of the surface of the mold and the rods is carried out in accordance with the order given above.

0 A test of the model that implements the proposed technical solution showed that the use of the proposed method and the device for lubricating the forms used to pour it under

5 pressure allows to increase productivity by 10%, to increase the durability of the mold by 15%, to reduce the cost of repair and operation of foundry equipment by 5%.

0

Claims (2)

1. A method of controlling a die casting machine, comprising preparing lubricants of different composition, applying it to the surface of the mold and rods, measuring the efforts to extract rods, adjusting the composition of the lubricant depending on the size of molds are cast under pressure during application of metered forces, and the ejection force of the casting is measured by regulating the lubricant of the initial composition, which is 10.5 kN. Then the amount of diluent in the lubricant is gradually increased while measuring the ejection force. Dilution is carried out to values at which no reliable ejection of the casting occurs. The ejection force, which is 32 kN, is measured. The maximum ejection force is a force of 0.8 of a limit of 25.6 kN. The operating range of the extraction forces of the rods is set as follows. After stabilization of the mold operation mode when applying the lubricant of the initial composition, the extraction forces of the rods are measured. So, for 1 The lubricant composition starts from the maximum lubricant content in it by increasing the diluent content, and as the force rises above the technologically acceptable value, the diluent content is reduced to its original value, characterized in that, in order to improve the process performance, the extrusion strength of the casting is additionally measured. the shapes, moreover, measure the gap between the molds at the moments, respectively the shape and closure of the half-molds; the size of the gap determines the presence of an oblo in the connector of the form, and if present at the time of opening the form, the content of the diluent is retained previous, and in the presence of an oblo at the moment of closing of the half-molds, it is removed, with an increase in the stretching force of the casting from the mold above the technologically acceptable value, in the absence of oblo, the amount of diluent decreases, 2. A device for controlling an injection molding machine, containing lubricant tanks of various compositions, connected to the dosage units of lubricant and diluent in the tanks, including reservuars for the lubricant and diluent, connected via pipelines to pumps and through electrically controlled chokes with tanks, electrically operated valves five 0 a pneumatic network connected by pipelines with tanks and nozzles, a system of lubrication to the nozzles, including pipelines with pumps, connecting tanks with nozzles through electrically operated valves, and a control unit connected to sensors for measuring rod extraction forces and electric controls throttles and valves, characterized in that, in order to increase the productivity of the process, it additionally contains sensors for monitoring the gap between the molds and the molding ejection force, the initial starting ska, the moment of opening of the form and the moment of closing of the half-forms connected to the control unit.