Electromagnetic relay, joining structure for hinge spring and yoke in the electromagnetic relay and flux penetration preventing structure

摘要

An electromagnetic relay has an iron core (1), an armature (2), a coil (12) wound around the iron core (1), a yoke (3), a hinge spring (6), and a joining structure. The yoke (3) is fastened rigidly to the iron core (1) and has an engaging hole (3b) and a fitting portion (3a, 3d). The hinge spring (6) is used to support the armature (2) rotatably on the yoke (3), and the joining structure is used to join the hinge spring (6) to the yoke (3) in the electromagnetic relay. The hinge spring (6) has a tongue (6a) and a dish-shaped portion (6b), and the yoke (3) has an engaging hole (3b) and a fitting portion (3a, 3d) for engaging with the tongue (6a) and the dish-shaped portion (6b). The hinge spring (6) is joined to the yoke (3) by inserting and fitting the hinge spring (6) into the yoke (3). This structure serves to simplify the process of assembling the hinge spring to the yoke and drastically reduce the number of assembling steps required. Further, in a flux penetration preventing structure of the electromagnetic relay, a coil bobbin (4) is formed, integral with or separate from a base block (9), and a venting portion (4c), for allowing air trapped in a center hole in the coil bobbin (4) to be vented therethrough, is formed in an upper flange (4b) of the coil bobbin (4). Therefore, sealing work of the base block of the electromagnetic relay can be performed smoothly and pinhole-free sealing thereof can be provided.