Magnetic-Field Press: Soft-Steel Punches as the Poles (Cochardt, US 3,412,461, 1968)

A press that lines magnetic powder up while it squeezes it. Two punches of magnetically soft steel close a die, and two coils around them make the punches the poles of an electromagnet. The field runs straight through the powder from one punch face to the other. Result: a press for anisotropic magnets, about 4000 oersted in the pressing space. Source: A. W. Cochardt, US 3,412,461 (1968). Unknown: the die's metal, sizes, coil windings, the press and the pump. Picture: the patent drawing.

متقدم

Unknown

التعليمات

Make the punches and the die

Make an upper and a lower press member (punches) of magnetically soft steel. Then the magnetic gap is only the thickness of the part being pressed. Make a die wall that the punches close to form a flat cavity. A wide, thin cavity keeps the field lines straight; they bend only at its edges. Ours: mild steel for the punches. Not given: the die's metal, sizes.

المواد لهذه الخطوة:

قضيب مستدير من صلب طري1 upper and lower punches

معدن غير معروف1 die

الأدوات المطلوبة:

مخرطة معادن

أبعاد غير معروفة

Wind the two coils

Wind two coils to sit around the punches, one above the die and one below, so that together they drive a field along the pressing direction. The patent's coils were water-cooled. Ours: enamelled copper wire. Not given: the turns, the wire size, how the cooling water runs.

المواد لهذه الخطوة:

سلك نحاسي مطلي بالمينا1 two coils

الأدوات المطلوبة:

ماء

أبعاد غير معروفة

Mount it in a press

Mount the punches, die and coils in a press, so the upper punch and the die can move down together while the lower punch stays put. Connect the coils to a current supply. Ours: a hydraulic press and a DC supply. Not given: the press, the supply.

الأدوات المطلوبة:

مكبس هيدروليكي

مصدر تغذية بالتيار المستمرّ

Press a plate in the field

Raise the lower punch, lower the upper punch into the die, and pump in a ferrite slurry: water with 1 to 2 percent dispersing agent. Move the upper punch and die down to press the slurry and drive out the water, and energise the coils at the same time, to about 4000 oersted. A plate 0.5 x 10 x 9 cm took 8200 watts. Demagnetise the plate as far as possible, then raise the punch, lower the die and lift the plate off the lower punch. Ours: a diaphragm pump.

الأدوات المطلوبة: