| 摘要 |
<p>1. Process for obtaining a coil with a closed magnetic circuit and with a permanent magnet for the ignition of internal-combustion engines, the coil comprising : a permanent magnet (6) for the primary winding (4) and secondary winding (5) which are accommodated in an insulating housing (3) surrounding a branch of the closed magnetic circuit (1) consisting of sheet-metal strips (2) stacked on top of one another, the process being characterised in that, in order to increase the surface of the closed magnetic circuit (1) in contact with the active surfaces (S1, S'1) of the permanent magnet (6), the strips (2) of width E are previously bent as a single unit at right angles to a radius R1 and at an unequal distance from their ends, in such a way that, after stacking in the form of an L-shaped pack (2a), the transverse edges (2b and 2c) of the strips (2) are respectively located on planes P and P' corresponding to the planes of the active surfaces S1, S'1 of the permanent magnet (6), so that, after the insulating housing (3), in which the primary winding (4) and secondary winding (5) are accommodated, has been fitted over a portion (2e) of the pack (2a), the latter is shaped by means of bending according to radii R2 increasing from the inner perimeter of the magnetic circuit (1) to its outer perimeter, for closing the said circuit (1) on the active surfaces S1, S'1 of the permanent magnet (G), on which surfaces the pack (2a) is retained by means of a clamping device (100).</p> |
