When switching ON/OFF the Permanent Magnet System inside will be moved against the pole surface.
When the magnet is OFF the magnetic flux will be shortcircuited by the pole surface (Graphic 1).
When switching ON the magnet, the magnetic flux will flow through the pole surface and the workpiece
on top will be attracted and close the magnetic flux circle (Graphic 2).
- Permanent Magnets are independent from any power source, portable and fail-safe
- The clamping force and size of a permanent magnet system is limited by the internal
- A Permanent Magnet can be destroyed or demagnetized by external, very large magnet fields or heat > 80°C
With the help of a permanent load lifting magnet one can lift, move, place and transport ferromagnetic objects, as well as round or flat material. The pieces can be flat or cylindrical. The transport of round parts can also be carried out by means of a V-shaped recess on the holding surface. The lifting forces always depend on the material thickness.
The extraordinary adhesion of these devices, which are often referred to as solenoids, results from the use of NdFeB magnets (neodymium-iron-boron is an alloy of neodymium, iron and boron with the composition Nd2Fe14B from which the currently strongest permanent magnets are produced).
Advantages of a lifting magnet
The area of application of permanent load lifting magnets is very versatile. Everywhere where loads are to be held or handled without gripping, these lifting magnets are used. With these load holding devices, you can work quickly and safely. Their low external dimensions, simple construction, low weight and large performance spectrum guarantee an uncomplicated application.
It is a great help with loading/unloading operations (during all handling operations). These lift magnets are the ideal lifting devices in warehouses, workshops, tool factories, shipyards, steel construction, foundries, steel construction works, movement of injection and punching tools, etc. They offer handling solutions of all kinds, serving from small workshops to large industrial/manufacturing companies workshops. These operating magnets result in zero operating costs.
Even with a small space (integration into machine tools, material storage...) and by hoists with limited load-bearing capacity, productivity and performance are still increased. Crane capacities are optimized by simple mounting on the crane.
Only one operator is required to move the load vertically and/or horizontally. The load is always anchored and raised from above, i.e. the lifting system is always placed on the piece from above. There is no mechanical impairment of the piece. Lifting and transporting operations are ensured completely safely (with triple safety), i.e. the pull-off force is 3 times the recommended lifting force. This is particularly important in the case of rough, scaled surfaces, because a considerable air gap can occur.
The shift lever is stable, i.e. there is no rebounding of the shift lever.
Compared to mechanical alternatives, magnets bring decisive advantages in the lifting, transport and clamping of ferromagnetic pieces.
What are my advantages when clamping?
What are my advantages when lifting?
Should I switch by hand or electronically? Is it always the most expensive? When and where do I use which load lifting magnet? These are the essential questions that we have had to answer about ASSFALG magnets. A selection of our articles from different product classes will help you in your choice and show you the advantages and disadvantages of the different load lifting magnet types.
Elift - The Universal Type
The universal permanent load lifting magnet Elift, which can be switched by a hand lever, is ideally suited for vertical and horizontal operations, for short, flat (from 15mm) and round pieces, and at an application temperature of up to 80°C. Our Elift HOT lifts up to a temperature of 500°C.
SB 950-SF - simply modern
The SB 950-SF is the first electro-magnetic battery lifter to indicate to the operator, on the display, which load it can safely lift during the lifting process. The power electronics calculated this data within seconds and automatically while putting the magnet on the work piece. Sheets from 4 mm thickness can also be lifted off the stack individually. Even magnetizing and demagnetizing of the electropermanent battery magnet can take place automatically.
All the lifting magnets used for crane operations must have the safety factor 3 in Europe. This is often indicated with the designation SWL 3:1 (safe workload).
This means that a 500 kg device must have a breaking load of at least 1,500 kg.
To ensure safety permanently, annual UVV tests should be carried out.
We distinguish here between magnetizing (the device is switched on) and demagnetizing (the device is switched off).
Switching on the lifting magnet
The device consists of two parts, a fixed part and a movable part. The moving part has been rotated through 180 degrees by means of the shift lever, so that the same poles are now placed one above the other. Equal poles repel each other, and the magnetic force lines now flow through the steel poles and through the piece, closing both magnetic circuits. The load is therefore tightened.
Switching off the lifting magnet
Here, opposite poles face each other, creating an internal magnetic circuit within the steel pole of the magnet.
The price of a permanent load lifting magnet depends, on the one hand, on which pieces or a round or flat material must be lifted and transported, and, on the other hand, on the quality and quality of the pieces/material.
Compared with mechanical alternatives Magnets bring distinct advantages in lifting, transporting and clamping of ferromagnetic workpieces.
AlNiCo-Magnets (surrounded by coil) can be magnetized as N-pole or S-pole by a current impulse (Graphic 1 + 2).
The AlNiCo-Magnets are exactly opposed to the polarization of the Neodym Permanent Magnets with the magnet being switched OFF (Graphic 1).
The AlNiCo-Magnets are rectified to the polarization of the Neodym Permanent Magnets with the magnet being switched ON (Graphic 2).
Electropermanent Magnets keep their magnetized condition.
- Electropermanent Magnets are Permanentmagnets which are switched electrically. They do not warm up and consume only very little energy (impulse current).
- They combine the safety of Permanentmagnets with the convenience of Electromagnets.
All Assfalg Electropermanent Magnetic chucks are equipped with a maximum of poles in the relationship to the size of the chuck.
If you review a price comparison, it is important for you, to analyze the clamping force of the chuck, because not the size of the chuck is important for the clamping force but the numbers of the poles are crucial for the clamping force of the magnetic chuck. It can mean that you will have bigger price differences by the same size of the magnetic chucks.
You have already informed yourself about magnetic clamping, but for you are the advantages of the different Electropermanent Square Pole Chucks not yet understandable? Before you decide for a Electropermanent Magnetic Chuck, represented on the market, please ask you the following questions:
The Electropermanent Magnetic Chuck from Assfalg Magnaslot is ideally suited for clamping of small and big work pieces for milling operations. Pole extensions, easily fixed on the surface of the magnetic chucks, guaranted a clamping without distortion even for uneven work pieces. The full steel body, patented and only available by Assfalg-magnets, offers an ideal protection against external influences like hot chips and coolant. If you work very big work pieces, you will get optionally a 4 channel controller, making a simultaneous switching of max. 4 magnetic chucks.