- about us
- contact us
overview of permanent magnets:
electric permanent magnet is a magnetic conveying and clamping system with magnetic or non-magnetic force that is used to control the electric permanent magnet by electricity to generate attractive force from permanent magnetic materials
the magnetic force of the electric permanent magnet comes from two high-energy magnetic materials that make up the magnetic circuit inside it: neodymium iron boron magnet and alnico magnet. electricity is used to control the internal magnetic circuit of the permanent magnet to switch, and to externally characterize the magnetic (magnetized state) or non-magnetic (demagnetized state) to realize the adsorption and release of the material by the magnet. as shown below:
figure 1.1 demagnetization state (the lines of magnetic force form a magnetic circuit inside the permanent magnet)
provide instantaneous (less than 0.3 seconds) electric energy to the electric permanent magnet, the electric permanent magnet magnetic circuit conversion:
figure 1.2 magnetization state (magnetic lines of force form a loop through external materials to generate suction)
the electric permanent magnet attraction is provided by high-energy permanent magnet steel. after the electric permanent magnet enters the magnetizing state, the attraction is not affected by environmental factors other than high temperature. power failure does not affect the suction power. the unique magnetic circuit design, through the numerous magnetic steel gap grids, makes the magnetic lines of force flow in the horizontal plane area to form a loop to generate a large suction force. only when the magnetic circuit is switched, the instantaneous electric energy is connected, no electricity is used during the working process, and the magnetic circuit has a fast switching time. in the demagnetization state, the magnetic field lines form a loop inside, and the residual magnetism of the working surface and the workpiece is extremely low.
compared with other types of magnetic equipment, electric permanent magnet has the characteristics of safety, stability and energy saving.
the electro-permanent magnet body can produce a maximum of 16kg/cm^2 suction to carbon steel and other ferromagnetic materials under 0 air gap. at the same time, the suction force of the electro-permanent magnet to the material is proportional to the effective adsorption area (figure 1.3), and the air gap in an inversely proportional function (figure 1.4), in an air gap environment, the suction is proportional to the adsorption area and the thickness of the permanent magnet body.
the electric permanent magnet only needs electric energy when the magnetic circuit is converted. when the magnetic circuit is converted to the normal operating frequency, the electric permanent magnet does not require special consideration of the influence of the coil heating on the electric permanent magnet. when the switching frequency is high, the electric permanent magnet needs to be designed according to the actual use frequency.
electric permanent magnetic chuck:
the electric permanent magnet chuck clamps and fixes the workpiece by suction, and is widely used in machining and welding occasions.
through magnetic clamping, the workpiece can be positioned on the surface of the suction cup, which can be used as a mechanical reference and a clamping area. the suction force is evenly distributed on the entire adsorption surface, the workpiece is not deformed by clamping pressure, and remains fully open. five-sided processing can be completed in one clamping. since there are no obstacles and constraints, the processing ability can be best used. there is no vibration in the machining process, but the cutting volume is increased, the tool life is prolonged, and the roughness and accuracy are improved.
the clamping state of the workpiece by the permanent magnet chuck includes direct clamping (figure 2.1) and indirect clamping (figure 2.2). direct clamping: the workpiece is in contact with the suction cup, and the workpiece is clamped by the suction force of the suction cup on the workpiece
indirect clamping is usually used to process non-magnetic workpieces (glass, plastic, aluminum shell, etc.). the workpiece is pressed and fixed on the suction cup by the suction force of the suction cup on the pressure plate. at this time, the friction (or side thrust) between the workpiece and the suction cup starts leading role. the cutting force on the workpiece cannot be greater than the side thrust. under this condition, other auxiliary positioning and fixing methods can be added according to the actual processing technology. if the top surface of the workpiece needs to be processed, it can be hollowed out at a suitable position on the pressure plate to reserve space for the knife.
the suction cup controller can be interlocked with the cnc machine.
during the machining process, the machining stress of the workpiece can be eliminated by a simple method of demagnetization and then immediately magnetizing.
schematic drawings of various processing applications:
suction cups for milling (maximum suction per unit area 16kg/cm^2)
turnout processing suction cup (maximum suction per unit area 16kg/cm^2, used in a joint venture, the main products are exported to foreign and domestic high-speed rail)
cnc fixture small suction cup (maximum suction force is greater than 200kg under 1mm air gap, side thrust is greater than 30kg, mainly used for indirect clamping processing of electronic products) dimensions: 140×100×60
cnc fixture suction cup (suction force is greater than 200kg under 1mm air gap,
side thrust is greater than 30kg,) dimensions: 260×180×40
cnc fixture suction cup (suction force up to 80kg under 2.5mm air gap, side thrust 10kg)
micro suction cup (suction force 150n, overall size: 35×60×42)
the first-generation electric permanent magnet chuck has a control method that is different from the conventional (second-generation) electric permanent magnet. the suction force is determined by design and is not adjustable. the suction force of this design is adjustable from 10-150kg.
glass workpiece clamping
arc-shaped suction cup (used for clamping round or arc-shaped workpieces on automated equipment, with a suction force greater than 900kg)