JPS6463658A - Ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To enhance the ignition performance of an ignition device in which the primary coil of an ignition coil section is divided into two parts each constituting a loop including a primary coil part and a d.c. power source, and these loops are selectively set to be a closed circuit, by enabling a set value of energizing current for each loop to be changed. CONSTITUTION:A primary coil 20I of an ignition coil 20 is constituted by first and second primary coils 20a, 20b, and two loops each including a d.c. power source and one of the first and second primary coils 20a, 20b may be turned into a closed circuit or an open circuit by means of switching sections 1, 2, respectively. Energization currents of the loops in their closed loop conditions may be detected by current detecting sections 3, 4, and during generation of an ignition instructing signal S, a control section 5 turns on and off the switching sections 1, 2 each time when the energizing current reaches a set value. In this arrangement, there are provided energizing time detecting sections 6, 7 for detecting the energizing times of the loops, and when the respective energizing times exceed a predetermined value, energizing current setting sections 8, 9 increase the set value of energizing currents.