Select the electro-hydraulic press will not be so difficult if you carefully examine all the nuances of such equipment. It will also be necessary to familiarize yourself with the overview of the electrical models on 25 and 30, 50 and 75, 100 tons and 150 tons to understand what exactly needs.
Pros and cons
Electro-hydraulic press is a hydraulic compressive mechanism with an electric drive. It should be immediately noted that the electric drive has almost completely supplanted air and steam systems. It turned out to be much more economical, and therefore even some local advantages of pneumatic and steam schemes lost all importance. Now such systems are preserved only in obsolete equipment, and then in single copies. Therefore, the comparison will take between purely electrical and electro-hydraulic devices (completely pneumatic can be reached by braces).
Systems based on hydraulics are especially strong and reliable. With their help you can provide a multi-torque force. Such equipment is often recommended for hydrofilling. With a particularly slow motion, it is possible to make a fairly accurate configuration. Also celebrate more other advantages:
- Quite just adjust and control the effort;
- It is easy to influence the speed of the output link;
- Thanks to the transfer of kinematic fluid through pipes, including flexible, you can make an effort even to remote or moving parts of the structure.
But this does not mean that hydraulics is worn out of one advantages. Its characteristic weaknesses are:
- need to prevent a special fluid;
- The complexity of the system for controlling hydraulic fluids;
- relatively small efficiency;
- high cost of details and their maintenance;
- The probability of leakage of the working oil into the pressed zone.
Device and principle of operation
Movable crossbars of hydraulic presses make the so-called double strokes. They share (not counting technological breaks) on idle, working and reverse stages. In direct idling, primary preparation for action is performed. Working device is approaching the workpiece. At this point, the working fluid is not fed to the cylinders, and no useful work is performed.
With direct working movement, the workpiece is mechanically deformed. Just at that moment she gets the desired configuration. It is then that the device spends a large amount of mechanical power. Therefore, he needs a certain stock of energy. Its supplies an electric motor connected to the hydraulic circuit.
Actually, energy transformation performs a pump, and there are also launchers, measuring, safety devices.
Additionally allocate:
- working cylinders;
- cylinders for fluid return;
- connecting pipelines;
- hydraulic reinforcement;
- Film tanks under low pressure fluid;
- batteries;
- flywheels;
- Multipliers.
Views
Drives may have group and individual execution. In the first case, the total installed capacity decreases. A pump-battery station is installed in a separate room. The route for pipes connecting this station and the work part of the press is calculated mainly individually.
Such a solution is recommended for forging presses, where there are long technological pauses.
But it can be applied on conventional powerful systems when the hydraulic does not turn out to be put on the press itself either near it. Much less power is distinguished by a manual hydraulic press, but the essence of his work itself makes this technique beyond the limits of the topic.
Desktop press will take a certain place on the workbench. Outdoor puts almost arbitrarily and can have a greater power, but it will cost much more expensive. The network apparatus is predictable more powerful and more stable with rechargeable, and the time of continuous operation he has more, but for these advantages it is necessary to pay us to stationarity or low-standard system.
Therefore, the battery technique is predominantly acquired for electrical installation.
Best brands
The most popular options are now electrohydraulic presses:
- OPREMA 40i;
- “Parity-pro” (Models “PG20”, “PR10”, “P342M2”);
- Test products of the “PI” series from “Metrotest”;
- “OMA 665”;
- K 100 E Mega.
Tips for choosing
The most important indicator is a developed effort. You do not need to be an engineer to understand that devices on 25, 30 and 100, 150 tons are completely different categories with different capabilities and applications. The tenython indicator is enough for ordinary automotive or repairing household appliances. Big car service will be enough 40 or 50 tons. And equipment for 75 tons is suitable for editing heat-treated parts and other machine-building tasks.
However, there are a number of other subtleties. So, an important role is played by distance from the rod to the working platform. It is determined by the greatest value of the workpieces. Significantly and the presence of a pressure gauge. The more accurately the working pressure is regulated, the better. It is worth paying attention to:
- price;
- functionality (so that there are all the necessary options and not a single unclaimed);
- ease of maintenance (ridiculous and ruinous if the wizard from the service call each time for cleaning);
- availability of spare parts;
- Reviews of construction.
