System of rapid exchange of injection moulds

Three alternative systems of exchange of mould



The change of the mold injection machines is an operation that involves a significant risk. The economy of possible risks and costs of accidents must be taken into account to assess the cost of procurement of a quick-change system.

Most of the current systems of change require fast adaptation of the moulds to the system, in particular with regard to the method of centering and electric, and hydraulic connections to get the best out. On some systems it puts the emphasis on the variety of possibilities; in others, the simplicity and, in some, the flexibility of the solutions offered. It corresponds to the transformer, in each case, to choose the system that best suits the particular conditions of their facilities.

All updated mould change systems incorporate notable technical solutions. This article presents, by way of synthesis, the most salient features of three existing systems which correspond to the essential mentioned variety, simplicity, and flexibility advantages.
For a shop with a wide variety of machines and moulds, flexibility, sizes i.e. be a solution very complete, it is probably the most desirable feature. When performing very frequent changes in the same machines of moulds with varied features, it warranted the simplicity of the system and in intermediate cases, versatility.

The mechanical-hydraulic system to start

The johns-qmc for Start system is based on the strength of block elements by wedge, available 8 types with capacities ranging from 8 to 3000 T, fixing plates portamoldes from the machine and are electro-hydraulically operated to hold the mold by providing, at the same time, his centering. This implies that the moulds are fitted with plates based on standard measures Euronorm depending on the type of machine to be installed, which are also which usually incorporate hydraulic, thermal control and mold control systems. The lock and release of these elements is done using a security key and its actuation through double solenoid and a piston hydraulic, remained closed while lowering power since that hydropower is used only for the drive.



Preferably operating on the periphery of solidarity based on the mold plate, sure to have enough stiffness to the efforts of the opening of the mold can not to do flexar, although their thickness does not mean a great loss of career opening available for the machine.
The system is completed with a variety of cars portamoldes roll-on roll-outof height-adjustable, up to 20 tonnes admissible load, with a bed of rollers rotating to place the mold that is removed, and after the turn, correctly placing the mold to put. They are feasible, logically, the loading or unloading above, although they require a longitudinal displacement once located the molds to the correct height to liberate the salient element of upper lock.

Figure 1 Magnetic fixing plate screwed directly on the Euromap drills existing representing a decline of race only to 68 x 2 (136) mm. Does not require energy intake to maintain fixation and its desmagnetizado (controlled through security key) requires few seconds



Reversible magnetism in fixing moulds

The development of reversible magnetism by Tecnomagnetehas provided an extremely simple method of fixation of moulds. System consists of two plates, called modules quad-press, equipped with electro-permanent magnets that are, or she is set to portamoldes the machine plates and presenting a surface flat on which magnetically accede the molds. No they needed, because plates portamoldes.
These modules are available in two versions: the magnetic circuit of the qp Icomes integrated into mechanized expressly press porta-moldes dishes and self-contained version qp/Rmodules are directly fixed on the Euromapexisting holes by means of screws: in the latter case is lost a small part of the race of the opening of the machine due to the (68 mm on each plate) thickness of the magnetic plates.
The geometry of the magnetic circuit is made to allow interns drills for pumps pre-situación and both types of modules are available in versions "C"presses in cold and "H"for hot pressing.
The modules are equipped with proximity sensors that block immediately the work cycle if the mold is separated more than 0,2 mm in the magnetic surface, with what is detected, at the same time, if there are foreign matter on the surface of the plates or a bad initial positioning of the mold. Any modification of the moulds is not necessary to adapt them to this system and they are completely des-magnetizados after getting them out of the press.
Quadrisistemadeveloped and patented by Tecnomagneteis a permanent magnetic circuit for polarity square with a great power of attraction that not precise power supply during the phases of work, has no internal moving parts and therefore has a high reliability and lack of maintenance.
Modules are formed by plates machined in which they are hosted a series of cubic magnets, in which only one of the six faces works actively on the surface, while the other five are fully coated active magnets, producing a high concentration of force of five to one.

Figure 2 The light casts adapt with ease to Euronorm plates by means of a system of gear you need only a fraction of rotation of the lever, equipping the molds of the gear which also provides locations previously.



Magnets arranged laterally to the pole are static, while the dipuestos under the pole are reversible. The coils located on the reversible magnet engenders a strong magnetic field momentary, capable of reversing the polarity of this special type of magnet. This moves the internal magnetic field outward, activating the work surface. During the des-imantación phase, the magnetic flux is short-circuitado in the plate and nullifies the force of attraction.
The outer perimeter of the dishes is equipped with means for driving magnetic flows and isolate the machine's magnetic surface, eliminating the current magnetic existences. In the attached table you can see the powers of the various types of modules in this system, which consists in addition a switchable electronic control to the PCL in the machine and which can be set to the same by means of a system, magnetic also, that no precise fixing screws.

Automation of all the stages of change of moulds

The proposal of Engeland locationsIt is a complete line of systems for mould change in practice, which covers all aspects of the same: centered, using an ingenious system of mechanical diaphragm, coupling the ejectors and other filesystems hydraulic, mechanical, electrical and compressed air from molds, transport systems and the control computer of the procedures.

Figure 3 System start makes it necessary to provide plates Euronorm moulds and the fixed with a control system electro-hydraulic wedge that is blocked on the spot, providing at the same time the centering of the mold.




The objective of the system is the automate to the maximum change of the moulds, currently getting times from 2 to 5 minutes. Naturally, its cost can be high if a low-frequency changes of mould makes its repayment, but the use of some of its elements, perhaps combined with more traditional, can be interesting even for small workshops.
In the first of the described systems, molds must equip with Euronorm standard plates, which will be that make the mobile and fixed platen of the machine where the fastening systems are positioned. Distribution of sizes of the plates is usually made according to the power of the injection machine.
At an early stage of automation, are used to change elements of elevation of the floor, that is replace by means of horizontal transport, similar to the ones described earlier, manual or motorised drag to measure that progresses the automation of the whole. In a final stage, he tends to use carts portamoldes mounted on Rails, so it would be possible to mold changes directly from the control panel, including a pre-heating station to temper the mold and shorten the time of implementation underway after the change.
An alternative to the carts on Rails that provides locationsare air-cushion cars, particularly suitable for very heavy (up to 125 T) molds or when the space around the machine is limited. They require special soil and the corresponding connection of compressed air.

Figure 4 the conveyor roll-on/roll-off mould of start includes a turntable to meet easily the new mould once extracted and supported the previous being correctly positioned for its fixation.



Perhaps what distinguishes this system are the means of immediate interconnection developed for instant coupling of hydraulics, pneumatics, electricity and electronics of each mold, requiring minimal human intervention. It also highlights the rapid manual mooring for small system, consisting of plates standard with an opening especially toothed, corresponding to a backup toothed cast, which is set with a swing of lever and the whole fraction, now standardized, can be mounted on the machine.
The fixing system itself consists of 4 or more cylinders mounted on plates portamoldes from the machine, including terminals with rollers for lateral mounting casts auto-retención and Automatic centering.

The system selection criteria

The selection of the system or parts of one of them that you wish to incorporate should be under an approach that combines the profitability, with a short repayment period, the possibility of extending the automation if it provides for a further enlargement of the plant and, above all, security for the staff that manage them. The analysis of the cost in terms of lost skilled labor hours or simple unavailability for small accidents without considering other more serious may be surprised who not it has been recorded previously.

Figure 5 Systems locations are supplemented with a variety of couplers simple and multiple, manual or automatic, extraordinarily simplify these operations and they can join other quick mould change systems.





As you can see by the foregoing, there are ways to design a system of quick-change mould specific for each workshop of moulding, whose definition can assist technicians and operators of the same and the manufacturers of systems, in order to obtain maximum profitability of installation.

Systems of mechanical-hydraulic change imply that the moulds are fitted with plates based on standardized measures (Euronorm) depending on the type of machine to be installed

Magnetic modules are available in two versions: integrated porta-moldes dishes or in the form of placas-módulo which are fixed on the drill EUROMAP existing